KR102618118B1 - Liquid refrigerant mild method for supplying low temperature refrigerant to the suction side of the refrigerant liquid pump that circulates the refrigerant in the refrigeration system under increased pressure - Google Patents

Abstract

The present invention is an invention for the purpose of providing a liquid refrigerant circulation method that enables the liquid refrigerant condensed and liquefied in the condenser of the refrigeration system to be smoothly transferred and supplied to the suction side of the refrigerant liquid pump. The refrigeration system of the present invention comprises: a compressor (2) provided in the middle of a refrigerant circulation line (10) configured to form a closed circuit; a main condenser (3) configured to discharge a room-temperature liquid refrigerant that has been condensed and liquefied from the high-temperature, high-pressure gas refrigerant compressed and discharged from the compressor; a refrigerant liquid pump (4a) installed in a liquid refrigerant transfer line (4) connected to the outlet line (32) of the main condenser; a main solenoid valve (43) formed on the discharge side (42) of the refrigerant liquid pump (4a) and controlling the circulation of the liquid refrigerant; a main expansion valve (6a) installed between the main solenoid valve (43) and the inlet line (81) of the evaporator (8) to rapidly expand the liquid refrigerant supplied to the liquid refrigerant transfer line (4); and an evaporator (8) to rapidly expand and supply the refrigerant in a mist state supplied by the main expansion valve to absorb the surrounding heat in the process of evaporating through a heat exchange action that takes away the heat of the surrounding heat exchange medium, thereby converting it into a low-temperature gaseous state. According to the present invention, there is an effect of smoothly circulating the liquid refrigerant by supplying the low-temperature liquid refrigerant to the suction side of the refrigerant liquid pump without generating fresh gas.

Description

Liquid refrigerant mild method for supplying low temperature refrigerant to the suction side of the refrigerant liquid pump that circulates the refrigerant refrigerant in the refrigeration system under increased pressure}

The present invention relates to a liquid refrigerant circulation method for supplying and circulating low-temperature refrigerant to the suction side of a refrigerant liquid pump that circulates the refrigerant in a refrigeration system under increased pressure. More specifically, it relates to a liquid refrigerant circulation method provided in the middle of a refrigerant circulation line composed of a closed circuit. By supplying low-temperature refrigerant to the suction side of the refrigerant liquid pump, which circulates the refrigerant discharged from the outlet side of the condenser in an increased pressure state, which condenses and liquefies the high-temperature, high-pressure gaseous refrigerant compressed and discharged from the compressor, the refrigerant discharged from the condenser is transferred to the evaporator. It relates to a liquid refrigerant circulation method for supplying and circulating low-temperature refrigerant to the suction side of the refrigerant liquid pump of a refrigeration system configured to circulate smoothly to the side.

In general, refrigeration systems are used in refrigerators and freezers for storing food, beverages, food ingredients, etc. at low temperatures for long periods of time, or in air conditioners and refrigeration/freezing devices used to maintain a comfortable indoor temperature in the face of high outdoor air. It is known that

The refrigeration system of the prior art is composed of a compressor, condenser, expansion valve, evaporator, etc. connected to a refrigerant circulation circuit composed of a closed circuit, and the auxiliary devices include an oil separator, a water receiver, a liquid separator, and an electromagnetic valve. I'm doing it.

In addition, in the refrigeration system of the prior art, the high-temperature, high-pressure gaseous refrigerant that is compressed by a compressor that is connected to the refrigerant circulation circuit by charging the refrigerant is sent to the condenser. It is condensed and liquefied through heat exchange with air, water, etc. and sent to the expansion valve. Condensers installed outside (outdoors) are greatly affected by external temperature changes. For example, in the refrigeration system of the prior art, when the external temperature decreases during operation, the pressure of the condenser decreases, so the liquid refrigerant at room temperature that is condensed and liquefied in the condenser is not smoothly discharged through the outlet of the condenser. This may cause a phenomenon in which the liquid refrigerant is not smoothly transferred to the expansion valve. To prevent this, in the prior art, as shown in FIG. 9, the high temperature compressed in the compressor 100 and discharged to the outlet line 110 When high-pressure gaseous refrigerant is supplied to the inlet line 210 of the condenser 200, the condenser 200 transfers the high-temperature, high-pressure gaseous refrigerant flowing in through the inlet line 210 into an external (outdoor) heat exchange medium (air). , water, etc.) is condensed and liquefied through heat exchange, and the room temperature refrigerant liquid condensed and liquefied in the condensation 200 is discharged to the outlet line 220 and toward the expansion valve 600 through the liquid refrigerant transfer line 300. The liquid refrigerant transfer line 300 has a structure in which a refrigerant liquid pump 400 is installed along with an electromagnetic valve 500 and an expansion valve 600.

Therefore, the liquid refrigerant at room temperature, which is condensed and liquefied in the condenser 200 and discharged to the outlet line 220, is pumped by the pumping operation of the refrigerant liquid pump 400 installed in the liquid refrigerant transfer line 300 and is pumped through the electromagnetic valve ( Passing through 500, it is supplied to the expansion valve 600 and rapidly expanded, and the foggy refrigerant rapidly expanded in the expansion valve 600 flows into the evaporator 700 through the inlet line 710 of the evaporator 700. It evaporates through heat exchange with the heat exchange medium (air, water, etc.) in the room (referring to the space where the evaporator is installed) and turns into a low-temperature gaseous refrigerant, which flows into the inlet line 120 of the compressor 100 through the outlet line 720. It is configured to repeat the refrigerant circulation operation in which it flows into the compressor 100 and repeats the action of being compressed.

However, in the refrigeration system of the prior art, the condenser 200, which condenses and liquefies the high-temperature, high-pressure gaseous refrigerant compressed and discharged from the compressor 100, and discharges it, changes the internal pressure as the external temperature changes during operation of the refrigeration system. If this is lowered, a phenomenon may occur in which the high-temperature, high-pressure gaseous refrigerant discharged from the compressor 100 does not flow smoothly into the inlet line 210 of the condenser 200, and as a result, the condenser 200 is compressed. As the high-temperature and high-pressure gaseous refrigerant discharged from (100) does not flow in smoothly, the condensation efficiency is reduced, so there is a problem in that the liquid refrigerant at room temperature cannot be smoothly discharged through the outlet line (220). In addition, when the amount of refrigerant flowing into the inlet line 210 of the condenser 200 is not smooth, the discharge amount of refrigerant toward the outlet line 220 decreases, so the refrigerant liquid pump 400 flows through the suction side 410. Not only does it become impossible to smoothly suck in the liquid refrigerant, making it impossible to pump and transport the liquid refrigerant, but there are also problems such as the generation of flash gas in the liquid refrigerant discharged to the discharge side 420 of the refrigerant liquid pump 400. do.

In addition, in the refrigeration system of the prior art, as shown in FIG. 10, an oil separator 800 is formed between the inlet line 120 of the compressor 100 and the inlet line 210 of the condenser 200, while the condenser 200 ) can be configured to form a receiver 900 between the outlet line 220 of the condenser 200 and the refrigerant liquid pump 400. In this case, the outlet line 220 of the condenser 200 and the inlet of the receiver 900 (910) is connected, the outlet 920 of the receiver 900 and the suction side 410 of the refrigerant liquid pump 400 are connected, and the discharge side 420 of the refrigerant liquid pump 400 is an electromagnetic valve ( It can be configured as a structure connected to the 500) side. In addition, as shown in FIG. 11, a plurality of compressors 100 can be connected in parallel between the inlet line 210 of the condenser 200 and the outlet line 720 of the evaporator 700, or As shown in Figure 12, it may be configured to connect a plurality of compressors 100, a plurality of evaporators 700, a plurality of electromagnetic valves 500, and a plurality of expansion valves 600.

However, in the prior art refrigeration systems shown in FIGS. 10, 11, and 12, when the pressure of the condenser 200 is lowered like the refrigeration system shown in FIG. 9, the high-temperature, high-pressure gas refrigerant discharged from the compressor 100 Not only does it not flow smoothly into the condenser 200, but there is a problem in that the liquid refrigerant at room temperature, which is condensed and liquefied in the condenser 200, is not smoothly discharged to the outlet line 220. In addition, in Figures 11 and 12, In the case of a refrigeration system in which a plurality of compressors 100 and a plurality of evaporators 700 are connected in parallel as shown, when one of the plurality of evaporators 700 is stopped, transfer is performed to the plurality of compressors 100. The supply amount of the refrigerant is reduced, and accordingly, the discharge amount of the gaseous refrigerant that is compressed and discharged at high temperature and high pressure in the compressor 100 is also reduced, so the inflow amount of the high temperature and high pressure gaseous refrigerant flowing into the condenser 200 is reduced. Therefore, the discharge amount of the room temperature liquid refrigerant that is condensed and liquefied in the condenser 200 and discharged through the outlet line 220 is reduced, thereby preventing the refrigerant liquid pump 400 from smoothly pumping the room temperature liquid refrigerant. As a result, there is a problem in that the liquid refrigerant cannot be smoothly pumped and supplied to the expansion valve 600, and there is a problem in that flash gas is generated.

Registered Patent Publication No. 10-0666920 (announced on January 11, 2007) Registered Patent Publication No. 10-1049695 (announced on July 11, 2011) Registered Patent Publication No. 10-1355431 (announced on January 27, 2014) Registered Patent Publication No. 10-2477314 (announced on December 8, 2022)

The present invention was proposed in consideration of various problems appearing in the prior art as described above. The condenser, into which the high-temperature and high-pressure gaseous refrigerant discharged from the compressor of the refrigeration system flows, condenses the inflowed gaseous refrigerant through heat exchange with an external heat exchange medium. In order to smoothly transfer the liquid refrigerant at room temperature, which is condensed and liquefied in the condenser, to the suction side of the refrigerant liquid pump, a refrigeration device is constructed by using a plate heat exchanger or by inserting and installing a liquid separator inside the auxiliary condenser or receiver. By using a solution heater and a double-tube heat exchanger, the liquid refrigerant at room temperature, which is condensed and liquefied in the condenser, can be smoothly sucked into the suction side of the refrigerant liquid pump, and at the same time, the liquid refrigerant transferred through the pumping operation of the refrigerant liquid pump is It is a means of cooling part of the refrigerant through heat exchange and resupplying it to the suction side of the refrigerant liquid pump. Even if the condenser of the refrigeration system experiences a pressure decrease due to external temperature changes, the liquid refrigerant that is condensed and liquefied in the condenser is the refrigerant liquid. To enable smooth transfer and supply to the suction side of the pump, so that the liquid refrigerant at room temperature discharged from the condenser and the cooled liquid refrigerant that is cooled and re-supplied through heat exchange can be supplied to the suction side of the refrigerant liquid pump and sucked in. The purpose of the invention was to provide a liquid refrigerant circulation method that allows the liquid refrigerant to be smoothly sucked in and transferred to the suction side of the refrigerant liquid pump even if the pressure of the condenser drops due to external temperature changes. will be.

The present invention is a means to pursue the above object, and the refrigeration system of the first embodiment of the present invention is an embodiment using a plate heat exchanger, a compressor provided in the middle of a refrigerant circulation line configured to form a closed circuit, and the compressor A main condenser configured to discharge liquid refrigerant at room temperature by condensing and liquefying the high-temperature, high-pressure gaseous refrigerant that is compressed and discharged, a refrigerant liquid pump installed in a liquid refrigerant transfer line connected to the outlet line of the main condenser, and the refrigerant liquid. A main solenoid valve formed on the discharge side of the pump to control the circulation of liquid refrigerant, and a main expansion valve installed between the main solenoid valve and the inlet line of the evaporator to rapidly expand the liquid refrigerant transferred and supplied to the liquid refrigerant transfer line. And, an evaporator that absorbs the surrounding heat and converts it into a low-temperature gaseous state in the process of evaporating the refrigerant in the fog state, which is rapidly expanded and supplied from the main expansion valve, through a heat exchange action that takes away the heat from the surrounding heat exchange medium. In the refrigeration system configured to repeat the operation in which the refrigerant discharged from the outlet line of the evaporator flows into the compressor through the inlet line of the compressor,

The liquid refrigerant transfer line connected to the discharge side of the refrigerant liquid pump is connected to the inlet line of the evaporator with a main solenoid valve and a main expansion valve formed in order,

A main bypass line in which a first solenoid valve is installed is connected to the liquid refrigerant transfer line connected between the discharge side of the refrigerant liquid pump and the main solenoid valve, and a second solenoid valve and an auxiliary solenoid valve are connected to the main bypass line. An auxiliary bypass line with expansion valves sequentially connected is connected.

Each of the main bypass line and the auxiliary bypass line is connected to the liquid refrigerant inlet of the liquid refrigerant circulation passage and the gas refrigerant inlet of the fog refrigerant circulation passage, respectively, provided in parallel with the plate heat exchanger. A cooling refrigerant transfer line connected to the suction side of the refrigerant liquid pump is connected to the liquid refrigerant outlet of the circulation passage, and a gaseous refrigerant transfer line connected to the inlet line of the compressor is connected to the gaseous refrigerant outlet of the fog refrigerant circulation passage installed in parallel with the plate heat exchanger. As a means of configuring the lines to be connected,

When operating the refrigeration system, the liquid refrigerant at room temperature, which is condensed and liquefied in the main condenser and discharged to the outlet line, flows into the suction side of the refrigerant liquid pump, and the liquid refrigerant transferred to the liquid refrigerant transfer line through the main bypass line through the pumping operation. The liquid refrigerant transferred to the liquid refrigerant transfer line is divided into equal parts by the main bypass line and transferred to the main expansion valve. The liquid refrigerant is rapidly expanded in a fog state and flows into the inlet line of the evaporator to perform a heat exchange function. It is configured to circulate in a repeating state of being discharged to the outlet line and then introduced into the compressor through the inlet line of the compressor.

The liquid refrigerant transferred to the liquid refrigerant transfer line is divided into equal parts and transferred to the main bypass line, and the liquid refrigerant transferred to the main bypass line is further divided into equal parts and transferred to the auxiliary bypass line. The liquid refrigerant that is divided and transferred is rapidly expanded into a fog state by the auxiliary expansion valve and flows into the fog refrigerant circulation passage attached to the plate heat exchanger. During circulation, it takes heat from the liquid refrigerant circulating in the liquid refrigerant circulation passage, resulting in a heat exchange effect. It is configured to repeat the cycle of evaporating, being discharged through the gas refrigerant outlet, and flowing into the compressor, while the liquid refrigerant, which is equally transferred to the main bypass line and passes through the first auxiliary solenoid valve, is installed in a plate heat exchanger. While it flows into the liquid refrigerant circulation passage and circulates, it is cooled by a heat exchange action that takes heat from the foggy refrigerant circulating in the fog refrigerant circulation passage, and is discharged through the liquid refrigerant outlet, and is then transported along the cooling refrigerant transfer line to the suction side of the refrigerant liquid pump. It is characterized in that it is configured to circulate in a state where, when introduced, it is mixed with the liquid refrigerant at room temperature discharged from the outlet line of the main condenser and flows into the refrigerant liquid pump.

The refrigeration system of the second embodiment of the present invention uses an auxiliary condenser, and includes a compressor provided in the middle of a refrigerant circulation line configured to form a closed circuit, and condensing and liquefying the high-temperature, high-pressure gas refrigerant compressed and discharged from the compressor to room temperature. A main condenser configured to discharge the liquid refrigerant, a refrigerant liquid pump installed in the liquid refrigerant transfer line connected to the outlet line of the main condenser, and connected to the discharge side of the refrigerant liquid pump to control the circulation of the liquid refrigerant. a main solenoid valve, a main expansion valve installed between the main solenoid valve and the inlet line of the evaporator to rapidly expand the liquid refrigerant supplied to the liquid refrigerant transfer line, and a fog state that is rapidly expanded and supplied from the main expansion valve. An evaporator is configured to convert the refrigerant into a low-temperature gaseous state by absorbing the surrounding heat during the evaporation process through a heat exchange action that takes away the heat from the surrounding heat exchange medium, and the refrigerant discharged through the outlet line of the evaporator is In a refrigeration system configured to repeat the operation of flowing into the compressor through the inlet line of the compressor,

The main bypass line connected to the liquid refrigerant transfer line connected to the discharge side of the refrigerant liquid pump is connected to the inlet line of the auxiliary condenser with an auxiliary solenoid valve installed,

Means configured to connect the outlet line of the auxiliary condenser and the suction side of the refrigerant liquid pump by a cooling refrigerant transfer line,

When operating the refrigeration system, the liquid refrigerant at room temperature, which is condensed and liquefied in the main condenser and discharged to the outlet line, flows into the suction side of the refrigerant liquid pump, and the liquid refrigerant transferred to the liquid refrigerant transfer line by the pumping operation is divided into equal parts by the main bypass line. Some of the liquid refrigerant transferred to the liquid refrigerant transfer line is transferred to the main expansion valve, rapidly expanded into a fog state by the main expansion valve, flows into the inlet line of the evaporator, circulates, and performs a heat exchange function, and then flows to the outlet. It is configured to cycle by repeating the operation of being discharged to the line and flowing into the compressor, while some of the liquid refrigerant divided into equal parts from the liquid refrigerant transfer line and transferred to the main bypass line flows into the inlet line of the auxiliary condenser and is connected to the heat exchange medium. The liquid refrigerant is condensed and liquefied by the heat exchange action, and the liquid refrigerant condensed and liquefied in the auxiliary condenser is discharged to the outlet line and transferred to the suction side of the refrigerant liquid pump along the cooling refrigerant transfer line. The liquid refrigerant at room temperature is discharged to the outlet line of the main condenser. It is characterized in that it is configured to circulate in a state where it is mixed and flows into the refrigerant liquid pump.

The refrigeration system of the third embodiment of the present invention is an embodiment using a liquid heater for a refrigeration device, a compressor provided in the middle of a refrigerant circulation line configured to form a closed circuit, and condensing the high-temperature, high-pressure gas refrigerant compressed and discharged from the compressor. A main condenser configured to discharge liquefied liquid refrigerant at room temperature, a refrigerant liquid pump installed in a liquid refrigerant transfer line connected to the outlet line of the main condenser, and formed on the discharge side of the refrigerant liquid pump to circulate the liquid refrigerant. A main solenoid valve that controls the action, a main expansion valve installed between the main solenoid valve and the inlet line of the evaporator to rapidly expand the liquid refrigerant supplied to the liquid refrigerant transfer line, and a main expansion valve that rapidly expands and supplies the liquid refrigerant. An evaporator is configured to convert the refrigerant in a fog state into a low-temperature gaseous state by absorbing the surrounding heat in the process of evaporation through a heat exchange action that takes away the heat from the surrounding heat exchange medium, and is discharged through the outlet line of the evaporator. In a refrigeration system configured to repeat the operation of the refrigerant flowing into the compressor through the inlet line of the compressor,

The liquid refrigerant transfer line connected to the discharge side of the refrigerant liquid pump is connected to the inlet line of the evaporator with the main solenoid valve and main expansion valve formed in order,

An auxiliary solenoid valve is installed in the main bypass line connected to the liquid refrigerant transfer line connected between the discharge side of the refrigerant liquid pump and the main solenoid valve, and is connected to the inlet of the receiver that constitutes the liquid heater for the refrigeration device. The outlet of the liquid receiver constituting the liquid heater for the refrigeration device is connected to the suction side of the refrigerant liquid pump by a cooling refrigerant transfer line,

The inlet of the liquid separator inserted and installed inside the liquid receiver constituting the liquid heater for the refrigeration device is connected to the outlet line of the evaporator, and the outlet of the liquid separator is connected to the inlet line of the compressor,

The liquid refrigerant that flows into the suction side of the refrigerant liquid pump discharged from the outlet line of the main condenser and is transferred to the liquid refrigerant transfer line through the pumping operation is divided into equal parts by the main bypass line and transferred. The liquid refrigerant transferred to the liquid refrigerant transfer line is rapidly expanded into a fog state at the main expansion valve, flows into the evaporator through the inlet line of the evaporator, circulates, and evaporates through heat exchange with the heat exchange medium, converting to a gaseous state and flowing to the outlet line. It is discharged and flows into the inlet of the liquid separator that constitutes the liquid heater for the refrigeration device, and while moving to the outlet side, it performs a heat exchange action with the liquid refrigerant at room temperature stored in the receiver, and then is discharged to the outlet and flows into the compressor. The operation is repeated. Meanwhile, some of the liquid refrigerant that is divided into equal parts and transferred to the main bypass line flows in through the inlet of the liquid heater for the refrigeration device, moves to the outlet, and flows into the inlet of the liquid separator while being discharged and moves to the outlet. Heat is taken from the gaseous refrigerant and is discharged to the outlet with its temperature lowered. It is transported to the suction side of the refrigerant liquid pump along the cooling refrigerant transfer line and mixed with the room temperature liquid refrigerant discharged to the outlet line of the main condenser to the refrigerant liquid pump. It is characterized in that it is configured to circulate in a state in which it flows into.

The refrigeration system of the fourth embodiment of the present invention uses a double-tube heat exchanger, and includes a compressor provided in the middle of a refrigerant circulation line configured to form a closed circuit, and a compressor that condenses and liquefies the high-temperature, high-pressure gas refrigerant compressed and discharged from the compressor. A main condenser configured to discharge liquid refrigerant at room temperature, a refrigerant liquid pump installed in a liquid refrigerant transfer line connected to the outlet line of the main condenser, and formed on the discharge side of the refrigerant liquid pump to circulate the liquid refrigerant. A main solenoid valve that controls, a main expansion valve installed between the main solenoid valve and the inlet line of the evaporator to rapidly expand the liquid refrigerant supplied to the liquid refrigerant transfer line, and fog that is rapidly expanded and supplied from the main expansion valve. An evaporator is configured to absorb the surrounding heat and convert it into a low-temperature gaseous state in the process of causing the refrigerant in the state to evaporate through a heat exchange action that takes away the heat from the surrounding heat exchange medium, and the evaporator is discharged through the outlet line of the evaporator. In a refrigeration system configured to repeat the operation of the refrigerant flowing into the compressor through the inlet line of the compressor,

The liquid refrigerant transfer line connected to the discharge side of the refrigerant liquid pump is connected to the inlet line of the evaporator with the main solenoid valve and main expansion valve formed in order,

In the liquid refrigerant transfer line connected between the discharge side of the refrigerant liquid pump and the main electromagnetic valve, a main bypass line and an auxiliary bypass line are connected to each other at a certain interval,

The main bypass line is connected to the inlet of a liquid separator constituting a double-tube heat exchanger with a first auxiliary solenoid valve and an auxiliary expansion valve installed, and the outlet of the liquid separator is connected to the inlet line of the compressor. Meanwhile, the auxiliary bypass line is connected to the inlet of the receiver constituting the double-pipe heat exchanger with a second auxiliary solenoid valve installed, and the outlet of the receiver is connected to the suction of the refrigerant liquid pump by the cooling refrigerant transfer line. As a means of configuring connection to the side,

When operating the refrigeration system, the liquid refrigerant at room temperature, which is condensed and liquefied in the main condenser and discharged to the outlet line, flows into the suction side of the refrigerant liquid pump, and the liquid refrigerant transferred to the liquid refrigerant transfer line by the pumping operation is connected to the main bypass line and auxiliary. The liquid refrigerant is divided into equal parts and transferred to the bypass line and the main expansion valve side, and the liquid refrigerant, which is divided into equal parts and transferred to the main expansion valve side, rapidly expands in a fog state in the main expansion valve and flows into the inlet line of the evaporator to perform heat exchange. It is then discharged to the outlet line and circulated to flow into the compressor. The liquid refrigerant divided into equal parts and transferred to the main bypass line is rapidly expanded into a fog state by the auxiliary expansion valve, and the refrigerant in a fog state is rapidly expanded by the auxiliary expansion valve. It flows into the inlet of the liquid separator formed in the double-tube heat exchanger, and while moving to the outlet side, it evaporates through heat exchange with the room temperature liquid refrigerant stored in the receiver, converts to a low-temperature gaseous state, and is discharged through the outlet to the compressor. While it is configured to circulate by repeating the inflow operation, the liquid refrigerant divided into equal parts and transferred to the auxiliary bypass line flows into the inlet of the liquid receiver constituting the double-tube heat exchanger and forms a fog state that moves inside the liquid separator while being stored. Heat is lost through heat exchange with the refrigerant, cooled to a low temperature, and discharged from the outlet of the receiver. The low-temperature liquid refrigerant discharged from the outlet of the receiver is transferred to the suction side of the refrigerant liquid pump along the cooling refrigerant transfer line. It is characterized by being configured to circulate and supply to the suction side of the refrigerant liquid pump in a mixed state with the liquid refrigerant at room temperature discharged from the outlet line of the main condenser.

According to the present invention, the refrigeration system of the first embodiment is configured to supply low-temperature liquid refrigerant to the suction side of the refrigerant liquid pump using a cooling refrigerant transfer line connected to the liquid refrigerant circulation passage installed in parallel with the plate heat exchanger. The refrigeration system of the second embodiment is configured to supply liquid refrigerant, which is condensed and liquefied at a low temperature, to the suction side of the refrigerant liquid pump using an auxiliary condenser, and the refrigeration system of the third embodiment is configured to supply liquid refrigerant to the suction side of the refrigerant liquid pump. It is configured to supply the low-temperature liquid refrigerant stored in the receiver of the solution heater to the suction side of the refrigerant liquid pump, and the refrigeration system of the fourth embodiment supplies the low-temperature liquid refrigerant stored in the receiver of the double pipe heat exchanger to the suction side of the refrigerant liquid pump. Since it is configured to supply to the suction side of the refrigerant liquid pump, even if the pressure of the condenser is lowered due to changes in external temperature, low-temperature liquid refrigerant can be supplied to the suction side of the refrigerant liquid pump. Since the operation of pumping the refrigerant can be performed accurately, it not only has the effect of allowing the liquid refrigerant to circulate smoothly without generating flash gas, but also improves the condensation efficiency of the condenser, increasing the refrigeration capacity of the refrigeration system. There is an effect.

1 and 2 are circuit diagrams of a refrigeration system using a plate heat exchanger.
Figures 3 and 4 are circuit diagrams of a refrigeration system using an auxiliary condenser.
Figures 5 and 6 are circuit diagrams of a refrigeration system using a liquid heater for a refrigeration device.
Figures 7 and 8 are circuit diagrams of a refrigeration system using a double-tube heat exchanger.
9 to 12 are circuit diagrams of a prior art refrigeration system.

A specific embodiment of a liquid refrigerant circulation method for supplying and circulating low-temperature refrigerant to the suction side of a refrigerant liquid pump that circulates the refrigerant in a refrigeration system according to the present invention under increased pressure will be described in detail with the accompanying drawings as follows.

1 and 2 are diagrams showing the circuit configuration of the refrigeration system of the first embodiment using a plate heat exchanger. First, the refrigeration system 1A of the first embodiment shown in FIG. 1 will be described. Closed circuit The high-temperature, high-pressure gaseous refrigerant that is compressed in the compressor (2) provided in the middle of the refrigerant circulation line (10) forming a The room temperature liquid refrigerant condensed and liquefied in the main condenser (3a) is discharged to the outlet line (32) and transferred to the liquid refrigerant transfer line (4). A refrigerant liquid pump (4a) is installed in the liquid refrigerant transfer line (4) to pump the room temperature liquid refrigerant discharged from the outlet line (32) of the main condenser (3a) and transfer and circulate it in an increased pressure state. there is.

In addition, the liquid refrigerant transfer line (4) connected to the discharge side (42) of the refrigerant liquid pump (4a) includes a main electromagnetic valve (43) for controlling the transfer of the liquid refrigerant by opening and closing operations and a main electromagnetic valve (43) for rapidly expanding the liquid refrigerant. The main expansion valves (6a) are sequentially installed and connected to the inlet line (81) of the evaporator (8), and the foggy refrigerant rapidly expanding in the main expansion valve (6a) passes through the inlet line (81). It flows into the evaporator (8) and circulates, and the foggy refrigerant that flows into the evaporator (8) and circulates is contained in the heat exchange medium (air, water, etc.) in the room (referring to the space where the evaporator is installed). In the process of evaporation through the heat exchange action that takes away heat, it absorbs the surrounding heat and is then converted to a low-temperature gaseous state and discharged to the outlet line (82), which flows into the compressor (2) through the inlet line (22) of the compressor and is compressed. It is configured to repeat the operation.

A feature of the first embodiment of the present invention is that the liquid refrigerant at room temperature, which is condensed and liquefied in the main condenser (3a) and discharged to the outlet line (32) and transferred to the liquid refrigerant transfer line (4), is converted into a plate heat exchanger (7a). By cooling to a low temperature and supplying low-temperature liquid refrigerant to the suction side 41 of the refrigerant liquid pump (4a), a circular operation of transferring and supplying liquid refrigerant through the pumping operation of the refrigerant liquid pump (4a) is performed. It is structured so that it runs smoothly.

For this purpose, between the discharge side 42 of the refrigerant liquid pump 4a and the main solenoid valve 43 to increase pressure and transfer the liquid refrigerant at room temperature discharged to the outlet line 32 of the main condenser 3a through a pumping operation. Connected to the main bypass line (5a) is a portion of the liquid refrigerant at room temperature transferred to the liquid refrigerant transfer line (4), which is divided into equal parts and transferred to the plate heat exchanger (7a) in a bypass manner. An auxiliary bypass line (5b) is connected to the auxiliary bypass line (5b), which bypasses a portion of the liquid refrigerant at room temperature transferred to the main bypass line (5a) and transfers it to the plate heat exchanger (7a). The pass line 7b is connected.

The main bypass line (5a) is connected to the liquid refrigerant inlet (71) of the liquid refrigerant circulation passage (70a) provided in parallel with the plate heat exchanger (7a), and the auxiliary bypass line (5b) is connected to the plate heat exchanger (7a). It is configured to be connected to the gas refrigerant inlet 73 of the fog refrigerant circulation passage 70b provided in parallel with 7a).

In addition, a first auxiliary solenoid valve 51 is installed in the main bypass line 5a, and a second auxiliary solenoid valve 52 is installed in the auxiliary bypass line 5b connected to the main bypass line 5a. and an auxiliary expansion valve (6b) are installed at positions spaced apart from each other at regular intervals.

Accordingly, the liquid refrigerant at room temperature transferred to the liquid refrigerant transfer line 4 is not entirely transferred to the main expansion valve 6a, but part of it is divided into equal parts and transferred to the main bypass line 5a. The liquid refrigerant at room temperature, which is equally transferred to the line (5a), flows into the liquid refrigerant inlet (71) of the liquid refrigerant circulation passage (70a) provided in parallel with the plate heat exchanger (7a) and circulates, while the main bypass line The liquid refrigerant transferred in equal parts to the auxiliary bypass line (5b) connected to (5a) is rapidly expanded into a fog state by the auxiliary expansion valve (6b) and is connected to the fog refrigerant circulation passage (7a) provided in parallel with the plate heat exchanger (7a). It flows into the gas refrigerant inlet 73 of 70b) and circulates, and the liquid refrigerant flows into and circulates into the liquid refrigerant circulation passage 70a and the fog refrigerant circulation passage 70b, respectively, provided in parallel with the plate heat exchanger 7a. The refrigerant in the fog state is configured to circulate in a state where it performs heat exchange with each other.

As described above, the liquid refrigerant circulating in the liquid refrigerant circulation passage 70a provided in parallel with the plate heat exchanger 7a and the fog refrigerant circulating in the fog refrigerant circulation passage 70b are configured to circulate while exchanging heat with each other. It is done. That is, the liquid refrigerant circulating in the liquid refrigerant circulation passage (70a) provided in parallel with the plate heat exchanger (7a) is cooled by a heat exchange action in which heat is taken away from the foggy refrigerant circulating in the fog refrigerant circulation passage (70b). On the other hand, the foggy refrigerant circulating in the fog refrigerant circulation passage (70b) is evaporated through a heat exchange action that takes away heat from the liquid refrigerant circulating in the liquid refrigerant circulation passage (70a) and changes into a gaseous state, thereby reaching the gas refrigerant outlet (70a). The operation of being discharged to 74) and flowing into the compressor 2 through the inlet line 22 of the compressor 2 is repeated.

Meanwhile, the liquid refrigerant flowing into and circulating in the liquid refrigerant circulation passage (70a) provided in parallel with the plate heat exchanger (7a) is cooled by a heat exchange action in which heat is taken away from the foggy refrigerant circulating in the fog refrigerant circulation passage (70b). is discharged and transferred to the cooling refrigerant transfer line (9a) connected to the liquid refrigerant outlet (72). The cooling refrigerant transfer line (9a) is connected to the suction side (41) of the refrigerant liquid pump (4a), In addition, the cooling refrigerant transfer line (9a) is provided with a one-way check valve (91) that prevents the liquid refrigerant from flowing back from the suction side (41) of the refrigerant liquid pump (4a).

As described above, the cooled liquid refrigerant cooled while circulating through the liquid refrigerant circulation passage (70a) of the plate heat exchanger (7a) and discharged through the liquid refrigerant outlet (72) is transferred to the cooling refrigerant transfer line (9a) to cool the refrigerant liquid. It is supplied to the suction side (41) of the pump (4a). At this time, the liquid refrigerant at room temperature is discharged to the outlet line (32) of the main condenser (3a) through the suction side (41) of the refrigerant liquid pump (4a). Since it is supplied, the room temperature liquid refrigerant discharged to the outlet line 32 of the main condenser 3a is transferred to the suction side 41 of the refrigerant liquid pump 4a and the cooling refrigerant transfer line 9a. The cooled liquid refrigerant is mixed, and when the room temperature liquid refrigerant and the cooled liquid refrigerant are mixed on the suction side 41 of the refrigerant liquid pump 4a, the liquid refrigerant temperature is in the main condenser 3a. The temperature is lower than that of the room temperature liquid refrigerant that is condensed and liquefied and discharged to the outlet line (32). Accordingly, the room temperature liquid refrigerant that is condensed and liquefied in the main condenser (3a) and discharged to the outlet line (32) has a lower temperature. Since the maintained refrigerant liquid pump (4a) is smoothly transferred to the suction side (41), the refrigerant liquid pump (4a) can accurately pump and transfer the liquid refrigerant.

In addition, the refrigeration system (1A) of the first embodiment configured as described above includes an oil separator (11) installed in the refrigerant circulation line (10) between the compressor (2) and the main condenser (3a) as shown in FIG. It can be configured to collect and remove oil discharged like high-temperature, high-pressure gaseous refrigerant by filtration through the outlet line 21 of the compressor 2, and is also condensed and liquefied in the main condenser 3a and discharged through the outlet line 32. A receiver (4b) can be configured to temporarily store liquid refrigerant at room temperature. The outlet line (32) of the main condenser (3a) is connected to the inlet (44) of the receiver (4b), and the receiver (4b) is connected to the outlet line (32) of the main condenser (3a). The outlet 45 of (4b) is structured so that the suction side 41 of the refrigerant liquid pump (4a) is connected, and the liquid refrigerant at room temperature stored in the receiver (4b) is connected to the refrigerant liquid pump (4a). It can be configured to supply to the suction side 41, and each component formed to be connected to the liquid refrigerant transfer line 4 formed on the discharge side 42 of the refrigerant liquid pump 4a is shown in FIG. Since it is substantially the same as the first embodiment, detailed configuration and description will be omitted.

3 and 4 are diagrams showing the circuit configuration of the refrigeration system of the second embodiment using an auxiliary condenser, and the refrigeration system 1B of the second embodiment shown in FIG. 3 will be described.

In describing each component applied to the refrigeration system 1B of the above-described second embodiment, the same name and the same symbol are used for the same components as each component applied to the refrigeration system 1A of the first embodiment described above. This will be explained, and other components will be explained using different names and symbols.

In the refrigeration system (1B) of the second embodiment, the high-temperature, high-pressure gas refrigerant compressed by the compressor (2) provided in the middle of the refrigerant circulation line (10) forming a closed circuit and discharged to the outlet line (21) is connected to the inlet line (31). It flows into the main condenser (3a) and is condensed and liquefied through heat exchange with an external (outdoor) heat exchange medium (air, water, etc.), and the room temperature liquid refrigerant condensed and liquefied in the main condenser (3a) is connected to the outlet line (32). is discharged and transferred to the liquid refrigerant transfer line (4), where the liquid refrigerant at room temperature discharged from the outlet line (32) of the main condenser (3a) is pressurized through a pumping operation and transferred and circulated. A refrigerant liquid pump (4a) is installed to do this.

In addition, the outlet line 32 of the main condenser 3a is connected to the suction side 41 of the refrigerant liquid pump 4a, and the liquid refrigerant transfer line is connected to the discharge side 42 of the refrigerant liquid pump 4a ( In 4), the main electromagnetic valve (43) for controlling the transfer of liquid refrigerant by opening and closing operation and the main expansion valve (6a) for rapidly expanding liquid refrigerant are installed in order, and are connected to the inlet line (81) of the evaporator (8). It is configured to be connected, and the refrigerant in a fog state, which is rapidly expanded in the main expansion valve (6a), flows into the evaporator (8) through the inlet line (81) and circulates inside the room (referring to the space where the evaporator is installed). In the process of evaporation through a heat exchange action that takes away the heat from the heat exchange medium (air, water, etc.), it absorbs the surrounding heat and is then converted to a low-temperature gaseous state and discharged to the outlet line (82) to the inlet line (22) of the compressor. It is configured to repeat the operation of flowing into the compressor (2) through .

A feature of the second embodiment of the present invention is that the liquid refrigerant at room temperature, which is condensed and liquefied in the main condenser (3a) and discharged through the outlet line (32) and transferred to the liquid refrigerant transfer line (4), is transferred to the auxiliary condenser (3b). The refrigerant liquid pump (4a) can transport and supply low temperature liquid refrigerant through precise pumping operation by condensing and liquefying it at a low temperature and supplying the low temperature liquid refrigerant to the suction side (41) of the refrigerant liquid pump (4a). It is structured so that it can be done.

For this purpose, between the discharge side 42 of the refrigerant liquid pump 4a and the main solenoid valve 43 to increase pressure and transfer the liquid refrigerant at room temperature discharged to the outlet line 32 of the main condenser 3a through a pumping operation. Connected to is a main bypass line (5a) for dividing a portion of the liquid refrigerant at room temperature transferred to the liquid refrigerant transfer line (4) into equal parts and bypassing it to the auxiliary condenser (3b).

In addition, the main bypass line (5a) is connected to the inlet line (33) of the auxiliary condenser (3b) with the auxiliary solenoid valve (53) installed, and the outlet line (34) of the auxiliary condenser (3b) The suction side 41 of the refrigerant liquid pump 4a is connected to the cooling refrigerant transfer line 9a.

In addition, the cooling refrigerant transfer line (9a) is provided with a one-way check valve (91) to prevent backflow of room temperature liquid refrigerant discharged to the outlet line (32) of the main condenser (3a).

In addition, the refrigeration system (1B) of the second embodiment is an oil separator for filtering and removing oil contained in the high-temperature, high-pressure gas refrigerant that is compressed in the compressor (2) and discharged to the outlet line (21), as shown in FIG. (11) can be formed, and a receiver (4b) can be formed to temporarily store the liquid refrigerant at room temperature that is condensed and liquefied in the main condenser (3a) and discharged to the outlet line (32). The outlet line 32 of the main condenser (3a) is connected to the inlet 44 of (4b), and the suction side 41 of the refrigerant liquid pump (4a) is connected to the outlet 45. .

In the refrigeration system (1B) of the second embodiment described above, the high-temperature, high-pressure gaseous refrigerant that is compressed in the compressor (2) and discharged to the outlet line (21) flows into the inlet line (31) of the main condenser (3a) to the outside (outdoor). ) is condensed and liquefied through heat exchange with the heat exchange medium, and the room temperature liquid refrigerant condensed and liquefied in the main condenser (3a) is discharged to the outlet line (32) and sucked into the suction side (41) of the refrigerant liquid pump (4a). is pumped by the operation of the refrigerant liquid pump (4a) and is transferred and supplied to the liquid refrigerant transfer line (4) connected to the discharge side (42). The entire liquid refrigerant transferred to the liquid refrigerant transfer line (4) is the main While being transferred to the liquid refrigerant transfer line (4) instead of being transferred to the expansion valve (6a), it is divided into equal parts and transferred to the main bypass line (5a). At this time, the liquid refrigerant transferred to the main expansion valve (6a) is It is rapidly expanded into a fog state by the main expansion valve (6a), flows into the inlet line (81) of the evaporator (8), circulates through the evaporator (8), and exchanges heat with the heat exchange medium indoors (referring to the space where the evaporator is installed). In the process of absorbing the surrounding heat, it evaporates and is converted into a low-temperature gaseous state, discharged through the outlet line 82, and flowing into the compressor 2 through the inlet line 22 of the compressor 2. The operation is repeated. .

Meanwhile, the liquid refrigerant divided into equal parts and transferred to the main bypass line (5a) connected to the liquid refrigerant transfer line (4) flows in through the inlet line (33) of the auxiliary condenser (3b). The liquid refrigerant flowing into the inlet line 33 is condensed and liquefied through heat exchange with an external heat exchange medium (referring to the space where the auxiliary condenser is installed), and the liquid refrigerant condensed and liquefied in the auxiliary condenser 3b is connected to the outlet line 34. ) and is transported and supplied to the suction side 41 of the refrigerant liquid pump 4a along the cooling refrigerant transfer line 9a. The suction side 41 of the refrigerant liquid pump 4a is connected to the main condenser 3a. Since it is connected to the outlet line (32), the room temperature liquid refrigerant that is condensed and liquefied in the main condenser (3a) and discharged to the outlet line (32) and the liquid refrigerant that is transferred and supplied to the cooling refrigerant transfer line (9a) are refrigerant liquid pump ( It is in a state of mixing on the suction side (41) of the refrigerant liquid pump (4a). At this time, the liquid refrigerant mixed on the suction side of the refrigerant liquid pump (4a) is the same as that of the room temperature liquid refrigerant discharged to the outlet line (32) of the main condenser (3a). Since the temperature is lower than the temperature, the liquid refrigerant at room temperature discharged through the outlet line 32 of the main condenser 3a is sucked and transferred to the suction side 41 of the refrigerant liquid pump 4a, which maintains the low temperature. This is achieved smoothly, and as a result, the refrigerant liquid pump (4a) can precisely pump the liquid refrigerant sucked into the suction side (41) and transfer and supply it to the discharge side (42), so that the liquid refrigerant transfer line ( 4), the liquid refrigerant can be circulated in a smooth circulation operation.

5 and 6 are diagrams showing the circuit configuration of a third embodiment of the refrigeration system using a liquid heater for a refrigeration device, and the refrigeration system 1C of the third embodiment shown in FIG. 5 will be described. .

In describing each component applied to the refrigeration system (1C) of the above-described third embodiment, the same name applies to each component applied to the refrigeration system (1A) (1B) of the first and second embodiments described above. , will be described using the same symbol, and other components will be described using different names and symbols.

In the refrigeration system (1C) of the third embodiment described above, like the above-described embodiment, the high-temperature, high-pressure gas is compressed by the compressor (2) provided in the middle of the refrigerant circulation line (10) forming a closed circuit and discharged to the outlet line (21). The refrigerant flows into the main condenser (3a) through the inlet line (31) and is condensed and liquefied through heat exchange with an external (outdoor) heat exchange medium (air, water, etc.). The refrigerant is condensed and liquefied in the main condenser (3a) at room temperature. The liquid refrigerant is discharged through the outlet line 32 and transferred to the liquid refrigerant transfer line 4. The liquid refrigerant transfer line 4 contains room temperature liquid refrigerant discharged from the outlet line 32 of the main condenser 3a. A refrigerant liquid pump (4a) is installed to increase the pressure through pumping operation to transfer and circulate it.

In addition, the outlet line 32 of the main condenser 3a is connected to the suction side 41 of the refrigerant liquid pump 4a, and the liquid refrigerant transfer line is connected to the discharge side 42 of the refrigerant liquid pump 4a ( In 4), the main solenoid valve (43) for controlling the transfer operation of the liquid refrigerant by opening and closing operation and the main expansion valve (6a) for rapidly expanding the liquid refrigerant are installed in order, and the inlet line (81) of the evaporator (8) It is configured to be connected to the main expansion valve (6a), and the refrigerant in the fog state, which is rapidly expanded in the main expansion valve (6a), flows into the evaporator (8) through the inlet line (81) and circulates indoors (referring to the space where the evaporator is installed). In the process of evaporation through a heat exchange action that takes away the heat possessed by the heat exchange medium (air, water, etc.), the surrounding heat is absorbed and converted into a low-temperature gaseous state and discharged to the outlet line (82) and the inlet line (22) of the compressor. It is configured to repeat the operation of flowing into the compressor (2) through ).

A feature of the third embodiment of the present invention is that the room temperature liquid refrigerant, which is condensed and liquefied in the main condenser (3a) and discharged to the outlet line (32) and transferred to the liquid refrigerant transfer line (4), is transferred to the liquid heater for the refrigeration device (7b). ) to supply low-temperature liquid refrigerant to the suction side (41) of the refrigerant liquid pump (4a) by cooling it to a low temperature. It is designed so that the refrigerant can be sucked in, so that the pumping operation of the refrigerant liquid pump (4a) can be performed precisely and the circulation of the liquid refrigerant can be performed smoothly.

For this purpose, between the discharge side 42 of the refrigerant liquid pump 4a and the main solenoid valve 43 to increase pressure and transfer the liquid refrigerant at room temperature discharged to the outlet line 32 of the main condenser 3a through a pumping operation. There is a main bypass line ( 5a) is connected, and an auxiliary solenoid valve 53 is installed in the main bypass line 5a.

In addition, a cooling refrigerant transfer line (9a) is connected to the outlet (75b) of the liquid receiver (75) constituting the liquid heater (7b) for the refrigeration device and the suction side (41) of the refrigerant liquid pump (4a). The cooling refrigerant transfer line (9a) is equipped with a one-way check valve (91) that prevents the room temperature liquid refrigerant discharged to the outlet line (32) of the main condenser (3a) from flowing back.

In addition, a liquid separator 76 is installed inside the liquid receiver 75 constituting the liquid heater 7b for the refrigeration device, and the inlet 76a of the liquid separator 76 is connected to the outlet of the evaporator 8. It is structured so that the line 82 is connected, and the outlet 76b of the liquid separator 76 is connected to the inlet line 22 of the compressor 2.

In the refrigeration system (1C) of the third embodiment configured as described above, the high-temperature, high-pressure gaseous refrigerant compressed and discharged from the compressor (2) flows into the main condenser (3a) and is condensed through heat exchange with the external (outdoor) heat exchange medium. The liquefied liquid refrigerant at room temperature is discharged to the outlet line 32 and sucked into the suction side 41 of the refrigerant liquid pump (4a) installed in the liquid refrigerant transfer line (4), and the refrigerant liquid pump (4a) The liquid refrigerant at room temperature sucked into the suction side (41) is pumped by the operation of the refrigerant liquid pump (4a) and transferred to the liquid refrigerant transfer line (4) to which the discharge side (42) is connected. ), the liquid refrigerant at room temperature that is transferred to the discharge side (42) is not entirely transferred to the main expansion valve (6a), but part of it is transferred to the main bypass line (5a) connected to the liquid refrigerant transfer line (4). do.

Therefore, some of the liquid refrigerant transferred to the main expansion valve (6a) through the liquid refrigerant transfer line (4) is rapidly expanded into a fog state in the main expansion valve (6a) and passes through the inlet line (81) of the evaporator to the evaporator (8). ) and circulates in the room (referring to the space where the evaporator is installed), evaporates in the process of taking heat through heat exchange with the heat exchange medium in the room (referring to the space where the evaporator is installed), changes to a low-temperature gaseous state, and is discharged to the outlet line (82) to the liquid heater for the refrigeration device ( 7b) flows into the inlet 76a of the liquid separator 76. The low-temperature gas refrigerant flowing into the inlet 76a of the liquid separator 76 flows into the receiver 75 while moving toward the outlet 76b. In the process of performing a heat exchange action that takes heat away from the liquid refrigerant stored in ), the operation is repeated where it evaporates, is discharged through the outlet (76b), and flows into the compressor (2) through the inlet line (22) of the compressor.

Meanwhile, the liquid refrigerant transferred to the liquid refrigerant transfer line 4 is divided into equal parts by the main bypass line 5a and the liquid refrigerant transferred is at the entrance of the receiver 75 constituting the liquid heater 7b for the refrigeration device ( It flows in and is stored through 75a), and the liquid refrigerant stored in the receiver 75 flows into the inlet 76a of the liquid separator 76 and loses heat from the low-temperature gaseous refrigerant transferred to the outlet 76b. It is cooled to a low temperature, and accordingly, the liquid refrigerant discharged through the outlet 75b of the receiver 75 is cooled to a low temperature and is transferred along the cooling refrigerant transfer line 9a to the refrigerant liquid pump. It is supplied to the suction side (41) of (4a). At this time, the liquid refrigerant at room temperature condensed and liquefied in the main condenser (3a) is discharged to the outlet line (32) on the suction side (41) of the refrigerant liquid pump (4a). Therefore, the low temperature liquid refrigerant supplied to the cooling refrigerant transfer line (9a) is mixed with the room temperature liquid refrigerant discharged from the outlet line (32) of the main condenser (3a) and is sucked into the refrigerant liquid pump (4a). It is configured to flow into the refrigerant liquid pump (4a) while being sucked into the side (41).

In addition, the refrigeration system 1C of the third embodiment may additionally configure an oil separator 11 between the outlet line 21 of the compressor 2 and the inlet line 31 of the main condenser 3a, as shown in FIG. 6. A receiver (4b) for temporarily storing liquid refrigerant at room temperature may be additionally configured between the outlet line (32) of the main condenser (3a) and the suction side (41) of the refrigerant liquid pump (4a). .

7 and 8 are diagrams showing the circuit configuration of a fourth embodiment of the refrigeration system using a double-tube heat exchanger, and the refrigeration system 1D of the fourth embodiment shown in FIG. 7 will be described.

In explaining each component constituting the refrigeration system 1D of the above-described fourth embodiment, each component constituting the refrigeration system 1A, 1B, and 1C of each of the above-described first to third embodiments is the same. Configurations will be described using the same names and codes, and other components will be described using different names and codes.

Like each of the above-described embodiments, the refrigeration system (1D) of the fourth embodiment is compressed by the compressor (2) provided in the middle of the refrigerant circulation line (10) forming a closed circuit and discharged to the outlet line (21). The gaseous refrigerant flows into the main condenser (3a) through the inlet line (31) and is condensed and liquefied through heat exchange with an external (outdoor) heat exchange medium (air, water, etc.), and is condensed and liquefied in the main condenser (3a) at room temperature. The liquid refrigerant is discharged to the outlet line 32 and transferred to the liquid refrigerant transfer line 4. The liquid refrigerant transfer line 4 contains the room temperature liquid refrigerant discharged from the outlet line 32 of the main condenser 3a. A refrigerant liquid pump (4a) is installed to increase pressure through a pumping operation to transport and circulate the refrigerant.

In addition, the outlet line 32 of the main condenser 3a is connected to the suction side 41 of the refrigerant liquid pump 4a, and the liquid refrigerant is transferred to the discharge side 42 of the refrigerant liquid pump 4a. In the line (4), the main solenoid valve (43) for controlling the opening and closing of the transfer operation of the liquid refrigerant and the main expansion valve (6a) for rapidly expanding the liquid refrigerant are installed in order, and the inlet line (81) of the evaporator (8) It consists of a structure connected to the main expansion valve (6a), and the refrigerant in the fog state, which is rapidly expanded in the main expansion valve (6a), flows into the evaporator (8) through the inlet line (81) and circulates inside the room (the space where the evaporator is installed). In the process of evaporation, the heat exchange medium (air, water, etc.) takes away the heat possessed by the heat exchange medium (air, water, etc.), absorbs the surrounding heat and is then converted to a low-temperature gaseous state and discharged to the outlet line (82), which is then discharged to the inlet line of the compressor. It is configured to repeat the operation of flowing into the compressor (2) through (22).

A feature of the fourth embodiment of the present invention is that the liquid refrigerant at room temperature, which is condensed and liquefied in the main condenser (3a) and discharged to the outlet line (32) and transferred to the liquid refrigerant transfer line (4), is transferred to the double-tube heat exchanger (7c). By cooling to a low temperature, low-temperature liquid refrigerant can be supplied to the suction side 41 of the refrigerant liquid pump 4a, thereby supplying low-temperature liquid refrigerant to the suction side 41 of the refrigerant liquid pump 4a. It is configured to transfer and supply the liquid refrigerant so that the circulation of the liquid refrigerant can be performed smoothly through the pumping operation of the refrigerant liquid pump (4a).

For this purpose, between the main solenoid valve 43 and the discharge side 42 of the refrigerant liquid pump 4a for pumping and pressurizing the liquid refrigerant at room temperature discharged to the outlet line 32 of the main condenser 3a. The main bypass line (5a) divides the room temperature liquid refrigerant transferred to the liquid refrigerant transfer line (4) into equal parts and transfers and supplies it to the liquid refrigerant (77) and liquid separator (78) constituting the double tube heat exchanger (7c). ) and the auxiliary bypass line (5b) are connected.

The double-tube heat exchanger (7c) includes a receiver 77 that stores liquid refrigerant, and a liquid separator 78 that is formed to penetrate the receiver 77 in the longitudinal direction and stores gaseous refrigerant. ) It is composed of a double pipe structure that is inserted and installed inside.

The main bypass line (5a) is connected to the inlet (78a) of the liquid separator (78) constituting the double-pipe heat exchanger (7c) with the first auxiliary solenoid valve (54) and the auxiliary expansion valve (6b) installed, respectively. It is configured to be connected, and the auxiliary bypass line (5b) is connected to the inlet (77a) of the receiver (77) constituting the double pipe heat exchanger (7c) with the second auxiliary solenoid valve (55) installed. Consists of.

In addition, the outlet (77b) of the receiver (77) constituting the double-tube heat exchanger (7c) and the suction side (41) of the refrigerant liquid pump (4a) are connected by a cooling refrigerant transfer line (9a), and the cooling The refrigerant transfer line (9a) is equipped with a one-way check valve (91) that prevents the room temperature liquid refrigerant discharged from the outlet line (32) of the main condenser (3a) from flowing back into the cooling refrigerant transfer line (9a).

When operating the refrigeration system (1D) of the fourth embodiment configured as above, the high-temperature, high-pressure gaseous refrigerant compressed in the compressor (2) and discharged through the outlet line (21) flows into the inlet line (31) of the main condenser (3a). The high-temperature, high-pressure gaseous refrigerant flowing into the main condenser (3a) is condensed and liquefied through heat exchange with the heat exchange medium, is discharged to the outlet line (32), and is sucked into the suction side (41) of the refrigerant liquid pump (4a). It is discharged through the discharge side (42) through the pumping operation and is divided into equal parts and transferred to the main bypass line (5a) while being transferred to the liquid refrigerant transfer line (4). At this time, the liquid refrigerant transferred to the liquid refrigerant transfer line (4) is Some of the liquid refrigerant, which is not entirely transferred to the main expansion valve (6a), is transferred to the main bypass line (5a), while some of the liquid refrigerant is not transferred to the main bypass line (5a) but is transferred to the main expansion valve (6a). The liquid refrigerant is rapidly expanded in a fog state at the main expansion valve (6a) and flows into the inlet line (81) of the evaporator (8), in the process of performing heat exchange with the heat exchange medium in the room where the evaporator (81) is installed. The refrigerant, which absorbs heat and evaporates, is converted to a low-temperature gaseous state and discharged to the outlet line 82, and while circulating through the evaporator 8, the refrigerant is converted to a low-temperature gaseous state and discharged to the outlet line 82 through the compressor ( The operation of flowing into the compressor (2) through the inlet line (22) of 2) is repeated.

Meanwhile, the liquid refrigerant that is equally divided and transferred to the main bypass line (5a) and the auxiliary bypass line (5b) connected to the liquid refrigerant transfer line (4) is the liquid that constitutes the double-tube heat exchanger (7c). It is transferred to the separator (78) and the receiver (77). At this time, the liquid refrigerant transferred in equal parts to the main bypass line (5a) and the foggy refrigerant rapidly expanded in the auxiliary expansion valve (6b) are transferred to the liquid separator (78). While flowing into the inlet (78a) and moving toward the outlet (78b), it is evaporated through a heat exchange action that takes heat from the liquid refrigerant stored in the receiver (77) and discharged to the outlet (78b). In this way, the double-tube heat exchanger (7c) ), the evaporated refrigerant discharged from the outlet (78b) of the liquid separator (78) is mixed with the gaseous refrigerant discharged from the outlet line (82) of the evaporator (8) at the inlet of the compressor (2). The liquid refrigerant flows into the compressor (2) through the line (22) and is equally transferred to the auxiliary bypass line (5b) to the inlet (77a) of the receiver (77) constituting the double-tube heat exchanger (7c). It flows in and is stored in the receiver 77, and the liquid refrigerant stored in the receiver 77 flows through the inlet 78a of the liquid separator 78, which is installed through the receiver 77. It is cooled to a low temperature by a heat exchange action that takes away heat from the foggy refrigerant that flows in and moves toward the outlet (78b), and is discharged through the outlet (77b) and transferred to the cooling refrigerant transfer line (9a) to the refrigerant liquid pump ( It is transferred and supplied to the suction side 41 of 4a).

However, since the outlet line 32 of the main condenser 3a and the cooling refrigerant transfer line 9a are connected to the suction side 41 of the refrigerant liquid pump 4a, the suction of the refrigerant liquid pump 4a On the side 41, the room temperature liquid refrigerant that is condensed and liquefied in the main condenser (3a) and discharged to the discharge line 32 and the low temperature liquid refrigerant discharged to the receiver outlet (77b) of the double tube heat exchanger (7c) are mixed. Therefore, the temperature of the liquid refrigerant mixed at the suction side 41 of the refrigerant liquid pump 4a is maintained at a lower temperature than the room temperature liquid refrigerant discharged from the outlet line 32 of the main condenser 3a. The liquid refrigerant at room temperature, which is discharged to the outlet line 32 of the main condenser 3a, is quickly transferred to the suction side 41 of the refrigerant liquid pump 4a, which maintains a lower temperature. Since the liquid refrigerant is quickly sucked in by the pump (4a), the refrigerant liquid pump (4a) can precisely pump the quickly sucked liquid refrigerant and transport and supply the liquid refrigerant so that it circulates smoothly.

The refrigeration systems (1A to 1D) of the first to fourth embodiments of the present invention configured in this way are capable of maintaining the main condenser (3a) even if the internal pressure of the main condenser (3a) is lowered due to a temperature change that causes the external temperature to drop rapidly during operation. Since the liquid refrigerant at a temperature lower than the liquid refrigerant at room temperature discharged to the outlet line 32 of ) can be transported and supplied to the suction side 41 of the refrigerant liquid pump 4a ( 41), the refrigerant liquid pump (4a) precisely pumps the liquid refrigerant and supplies it to the liquid refrigerant transfer line (4), thereby improving the circulation of the liquid refrigerant. It provides an effect that allows you to do so.

1A, 1B, 1C, 1D: Refrigeration system 10: Refrigerant circulation line
11: Oil separator 2: Compressor
21,31,33,81: Inlet line 22,32,34,82: Outlet line
3a: main condenser 3b: auxiliary condenser
4: Liquid refrigerant transfer line 4a: Refrigerant liquid pump
4b: Receiver 41: Suction side
42: discharge side 43: main solenoid valve
44: entrance 44: exit
5a: main bypass line 5b: auxiliary bypass line
51,54: 1st auxiliary solenoid valve 52,55: 2nd auxiliary solenoid valve
53: Auxiliary solenoid valve 6a: Main expansion valve
6b: Auxiliary expansion valve 7a: Plate heat exchanger
7b: Liquid heater for refrigeration device 7c: Double tube heat exchanger
71: Liquid refrigerant inlet 72: Liquid refrigerant outlet
73: Gas refrigerant inlet 74: Gas refrigerant outlet
75,77: Receiver 76,78: Liquid separator
75a,76a,77a,78a: Entrance 75b,76b,77b,78b: Exit
8: Evaporator 9a: Cooling refrigerant transfer line
9b: Gas refrigerant transfer line

Claims (4)

A compressor (2) provided in the middle of the refrigerant circulation line (10) configured to form a closed circuit, and a main condenser (3) configured to discharge liquid refrigerant at room temperature by condensing and liquefying the high-temperature, high-pressure gaseous refrigerant compressed and discharged from the compressor. ), a refrigerant liquid pump (4a) installed on the liquid refrigerant transfer line (4) connected to the outlet line (32) of the main condenser, and a liquid refrigerant pump (4a) formed on the discharge side (42) of the refrigerant liquid pump (4a) The main solenoid valve 43 controls the circulation of the refrigerant, and the liquid refrigerant is installed between the main solenoid valve 43 and the inlet line 81 of the evaporator 8 and is transferred and supplied to the liquid refrigerant transfer line 4. A main expansion valve (6a) that rapidly expands the refrigerant in a fog state, which is rapidly expanded and supplied from the main expansion valve, and absorbs surrounding heat in the process of evaporating the refrigerant through a heat exchange action that takes away the heat from the surrounding heat exchange medium. An evaporator 8 is configured to convert the refrigerant into a low-temperature gaseous state, and the refrigerant discharged through the outlet line 82 of the evaporator 8 flows into the compressor 2. A refrigeration system is configured to repeat the operation ( In 1A),
In the liquid refrigerant transfer line (4) connected to the discharge side (42) of the refrigerant liquid pump (4a), the main solenoid valve (43) and the main expansion valve (6a) are formed in order, and the inlet line of the evaporator (8) (81), and a first solenoid valve (51) is installed in the liquid refrigerant transfer line (4) connected between the discharge side (42) of the refrigerant liquid pump (4a) and the main solenoid valve (43). The main bypass line (5a) is connected, and the main bypass line (5a) has an auxiliary bypass line (5b) in which a second solenoid valve 52 and an auxiliary expansion valve 6b are sequentially formed. connected,
The main bypass line (5a) and the auxiliary bypass line (5b) each have a liquid refrigerant inlet (71) and a fog refrigerant circulation passage (70b) of the liquid refrigerant circulation passage (70a) provided in parallel with the plate heat exchanger (7). It is connected to each of the gas refrigerant inlets 73, and the suction side 41 of the refrigerant liquid pump 4a is connected to the liquid refrigerant outlet 72 of the liquid refrigerant circulation passage 70a parallel to the plate heat exchanger 7. ) is connected to the cooling refrigerant transfer line (9a), and the inlet line (22) of the compressor (2) is connected to the gas refrigerant outlet (74) of the fog refrigerant circulation passage (70b) provided in parallel with the plate heat exchanger (7). ) as a means of configuring the gas refrigerant transfer line (9b) connected to the
When operating the refrigeration system (1A), the liquid refrigerant at room temperature, which is condensed and liquefied in the main condenser (3a) and discharged to the outlet line (32), flows into the suction side (41) of the refrigerant liquid pump (4a) and is pumped. The liquid refrigerant transferred to the liquid refrigerant transfer line (4) is divided into equal parts and transferred by the main bypass line (5a). The liquid refrigerant transferred to the liquid refrigerant transfer line (4) is divided into equal parts by the main bypass line (5a). The liquid refrigerant, which is divided into equal parts and transferred to the main expansion valve (6a), is rapidly expanded in a fog state, flows into the inlet line (81) of the evaporator (8), performs heat exchange, and is discharged through the outlet line (82) to the compressor (2). ) is configured to circulate in a state that repeats the operation flowing into the
The liquid refrigerant transferred to the liquid refrigerant transfer line (4) is divided into equal parts and transferred to the main bypass line (5a), and the liquid refrigerant transferred to the main bypass line (5a) is transferred to the auxiliary bypass line (5b). It is divided into equal parts and transferred, and at this time, the liquid refrigerant divided into equal parts and transferred to the auxiliary bypass line (5b) is rapidly expanded into a fog state by the auxiliary expansion valve (6b) and passes through the fog refrigerant circulation passage provided in parallel with the plate heat exchanger (7). While flowing into (70b) and circulating, the liquid refrigerant is evaporated through a heat exchange action that takes heat away from the liquid refrigerant circulating through the liquid refrigerant circulation passage (70a) and is discharged to the gaseous refrigerant outlet (74) to flow into the compressor (2). While configured to circulate repeatedly, the liquid refrigerant that is equally transferred to the main bypass line (5a) and passes through the first auxiliary solenoid valve (51) is transferred through the liquid refrigerant circulation passage (70a) provided in parallel with the plate heat exchanger (7). ), it is cooled by a heat exchange action that takes heat from the foggy refrigerant circulating in the foggy refrigerant circulation passage (70b), and is discharged to the liquid refrigerant outlet (72) and transported along the cooling refrigerant transfer line (9a). When flowing into the suction side (41) of the refrigerant liquid pump (4a), it is mixed with the room temperature liquid refrigerant discharged to the outlet line (32) of the main condenser (3) and circulates in a state that flows into the refrigerant liquid pump (4a). A liquid refrigerant circulation method for supplying and circulating low-temperature refrigerant to the suction side of a refrigerant liquid pump that circulates the refrigerant in a refrigeration system at increased pressure. A compressor (2) provided in the middle of the refrigerant circulation line (10) configured to form a closed circuit, and a main condenser (3) configured to condense and liquefy the high-temperature, high-pressure gaseous refrigerant compressed and discharged from the compressor to discharge liquid refrigerant at room temperature. ), a refrigerant liquid pump (4a) installed on the liquid refrigerant transfer line (4) connected to the outlet line (32) of the main condenser (3), and a liquid refrigerant pump (4a) connected to the discharge side (42) of the refrigerant liquid pump. The main solenoid valve 43 controls the circulation of the refrigerant, and the liquid refrigerant is installed between the main solenoid valve 43 and the inlet line 81 of the evaporator 8 and is transferred and supplied to the liquid refrigerant transfer line 4. A main expansion valve (6a) that rapidly expands the refrigerant, and the refrigerant in a fog state that is rapidly expanded and supplied from the main expansion valve absorbs the surrounding heat in the process of evaporation through a heat exchange action that takes away the heat from the surrounding heat exchange medium. In the refrigeration system (1B), which is comprised of an evaporator (8) that converts the refrigerant into a low-temperature gaseous state, and is configured to repeat the operation of flowing the refrigerant discharged through the outlet line (82) of the evaporator into the compressor (2). ,
The main bypass line (5a) connected to the liquid refrigerant transfer line (4) connected to the discharge side (42) of the refrigerant liquid pump (4a) is connected to the inlet of the auxiliary condenser (3b) with the auxiliary solenoid valve (53) installed. It is connected to the line 33, and the outlet line 34 of the auxiliary condenser 3b and the suction side 41 of the refrigerant liquid pump 4a are connected by a cooling refrigerant transfer line 9a,
When operating the refrigeration system (1B), the liquid refrigerant at room temperature, which is condensed and liquefied in the main condenser (3a) and discharged to the outlet line (32), flows into the suction side (41) of the refrigerant liquid pump (4a) and is pumped. The liquid refrigerant transferred to the liquid refrigerant transfer line (4) is divided into equal parts and transferred to the main bypass line (5a), and part of the liquid refrigerant transferred to the liquid refrigerant transfer line (4) is transferred to the main expansion valve (6a). is rapidly expanded into a fog state by the main expansion valve (6a), flows into the inlet line (81) of the evaporator (8), circulates and performs a heat exchange function, and then is discharged through the outlet line (82) and flows into the compressor (8). Meanwhile, part of the liquid refrigerant divided into equal parts from the liquid refrigerant transfer line (4) and transferred to the main bypass line (5a) flows through the inlet line (33) of the auxiliary condenser (3b). The liquid refrigerant flows in and is condensed and liquefied through heat exchange with the heat exchange medium, and the liquid refrigerant condensed and liquefied in the auxiliary condenser (3b) is discharged to the outlet line (34) and flows through the refrigerant liquid pump (4a) along the cooling refrigerant transfer line (9a). A refrigeration system characterized in that it is mixed with the liquid refrigerant at room temperature, which is transferred to the suction side (41) and discharged to the outlet line (32) of the main condenser (3a), and circulates in a state where it flows into the refrigerant liquid pump (4a). A liquid refrigerant circulation method for supplying and circulating low-temperature refrigerant to the suction side of a refrigerant liquid pump that circulates the refrigerant at increased pressure. A compressor (2) provided in the middle of the refrigerant circulation line (10) configured to form a closed circuit, and a main condenser (3a) configured to discharge a liquid refrigerant at room temperature by condensing and liquefying the high-temperature, high-pressure gaseous refrigerant compressed and discharged from the compressor. ), a refrigerant liquid pump (4a) installed on the liquid refrigerant transfer line (4) connected to the outlet line (32) of the main condenser (3a), and a liquid refrigerant pump (4a) formed on the discharge side (42) of the refrigerant liquid pump The main solenoid valve 43 controls the circulation of the refrigerant, and the liquid refrigerant is installed between the main solenoid valve 43 and the inlet line 81 of the evaporator 8 and is transferred and supplied to the liquid refrigerant transfer line 4. A main expansion valve (6a) that rapidly expands the refrigerant, and the refrigerant in a fog state that is rapidly expanded and supplied from the main expansion valve absorbs the surrounding heat in the process of evaporation through a heat exchange action that takes away the heat from the surrounding heat exchange medium. A refrigeration system (1C) comprising an evaporator (8) that converts the refrigerant into a low-temperature gaseous state, and repeating the operation of flowing the refrigerant discharged through the outlet line (82) of the evaporator (8) into the compressor (1). ) in,
The liquid refrigerant transfer line 4 connected to the discharge side 42 of the refrigerant liquid pump 4a is the inlet line of the evaporator 8 with the main solenoid valve 43 and the main expansion valve 6a formed in order. (81) and the main bypass line (5a) connected to the liquid refrigerant transfer line (4) connected between the discharge side (42) of the refrigerant liquid pump (4a) and the main solenoid valve (43). In the state in which the auxiliary solenoid valve 53 is installed, it is connected to the inlet 75a of the liquid receiver 75 constituting the liquid heater 7b for a refrigerating device, and the liquid constituting the liquid heater 7b for a refrigerating device The outlet 75b of the unit 75 is connected to the suction side 41 of the refrigerant liquid pump 4a by a cooling refrigerant transfer line 9a, and the liquid receiver constituting the liquid heater 7b for the refrigeration device (75) The inlet 76a of the liquid separator 76 installed inside is connected to the outlet line 82 of the evaporator 8, and the outlet 76b of the liquid separator 76 is the inlet of the compressor 2. Means configured to be connected to line 22,
During operation, the refrigeration system (1C) flows into the suction side (41) of the refrigerant liquid pump (4a), which is discharged to the outlet line (32) of the main condenser (3a), and is transferred to the liquid refrigerant transfer line (4) through pumping operation. The liquid refrigerant is divided into equal parts by the main bypass line (5a) and transferred, and the liquid refrigerant divided into equal parts by the main bypass line (5a) and transferred to the liquid refrigerant transfer line (4) is transferred from the main expansion valve (6a). It expands rapidly in a fog state and flows into the evaporator (8) through the inlet line (81) of the evaporator (8). As it circulates, it is evaporated through heat exchange with the heat exchange medium, converted to a gaseous state, and discharged through the outlet line (82). It flows into the inlet (76a) of the liquid separator (76) constituting the liquid heater (7b) for a refrigerating device, and while moving toward the outlet (76b), heat exchange occurs with the liquid refrigerant at room temperature stored in the liquid receiver (75). After performing the operation, it is discharged to the outlet (76b) and introduced into the compressor (2), and is configured to cycle by repeating the operation, while some of the liquid refrigerant divided into equal parts and transferred to the main bypass line (5a) is used as a liquid heater for a refrigerating device. A gas state that flows in through the inlet 75a of the liquid receiver 75 constituting (7b), moves toward the outlet, and is discharged, while flowing in through the inlet 76a of the liquid separator 76 and moving toward the outlet 76b. Heat is taken from the refrigerant and discharged to the outlet (75b) with the temperature lowered, and is transferred to the suction side (41) of the refrigerant liquid pump (4a) along the cooling refrigerant transfer line (9a) to the outlet line of the main condenser (3a). 32), low-temperature refrigerant is placed on the suction side of the refrigerant liquid pump that circulates the refrigerant under increased pressure in the refrigeration system, which is configured to circulate in a state where it is mixed with the room temperature liquid refrigerant discharged and flows into the refrigerant liquid pump (4a). Liquid refrigerant circulation method that supplies and circulates. A compressor (2) provided in the middle of the refrigerant circulation line (10) configured to form a closed circuit, and a main condenser (3a) configured to discharge a liquid refrigerant at room temperature by condensing and liquefying the high-temperature, high-pressure gaseous refrigerant compressed and discharged from the compressor. ), a refrigerant liquid pump (4a) installed on the liquid refrigerant transfer line (4) connected to the outlet line (32) of the main condenser (3a), and a liquid refrigerant pump (4a) formed on the discharge side (42) of the refrigerant liquid pump The main solenoid valve 43 controls the circulation of the refrigerant, and the liquid refrigerant is installed between the main solenoid valve 43 and the inlet line 81 of the evaporator 8 and is transferred and supplied to the liquid refrigerant transfer line 4. A main expansion valve (6a) that rapidly expands the refrigerant in a fog state, which is rapidly expanded and supplied from the main expansion valve, and absorbs surrounding heat in the process of evaporating the refrigerant through a heat exchange action that takes away the heat from the surrounding heat exchange medium. An evaporator 8 is configured to convert the refrigerant into a low-temperature gaseous state, and the refrigerant discharged through the outlet line 82 of the evaporator 8 flows into the compressor 2. A refrigeration system is configured to repeat the operation ( In 1D),
The liquid refrigerant transfer line 4 connected to the discharge side 42 of the refrigerant liquid pump 4a is the inlet line of the evaporator 8 with the main solenoid valve 43 and the main expansion valve 6a formed in order. (81), and the liquid refrigerant transfer line (4) connected between the discharge side (42) of the refrigerant liquid pump (4a) and the main solenoid valve (43) has a main bypass line (5a) and an auxiliary bypass line (5a). The pass lines 5b are connected to each other at regular intervals,
With the first auxiliary expansion valve 54 and the auxiliary expansion valve 6b installed in the main bypass line 5a, the inlet 78a of the liquid separator 78 constituting the double pipe heat exchanger 7c is connected to, and the outlet 78b of the liquid separator 78 is configured to be connected to the inlet line 22 of the compressor 2, while the auxiliary bypass line 5b is connected to a second auxiliary solenoid valve ( 55) is connected to the inlet (77a) of the receiver (77) constituting the double-tube heat exchanger (7c) in the installed state, and the outlet (77b) of the receiver (77) is connected to the cooling refrigerant transfer line (9a). As a means configured to be connected to the suction side (41) of the refrigerant liquid pump (4a),
During operation of the refrigeration system (1D), the liquid refrigerant at room temperature, which is condensed and liquefied in the main condenser (3a) and discharged to the outlet line (32), flows into the suction side (41) of the refrigerant liquid pump (4a) and is pumped. The liquid refrigerant transferred to the liquid refrigerant transfer line (4) is divided into equal parts and transferred to the main bypass line (5a), the auxiliary bypass line (5b), and the main expansion valve (6a), and the main expansion valve (6a) The liquid refrigerant that is divided into equal parts and transferred to the ) side is rapidly expanded in a fog state at the main expansion valve (6a), flows into the inlet line (81) of the evaporator (8), performs heat exchange, and is discharged through the outlet line (82) to the compressor. It circulates to flow into (2), and the liquid refrigerant divided into equal parts and transferred to the main bypass line (5a) is rapidly expanded into a fog state by the auxiliary expansion valve (6b), and rapidly expands in the auxiliary expansion valve (6b). The refrigerant in a fog state flows into the inlet (78a) of the liquid separator (78) formed in the double-tube heat exchanger (7c) and moves toward the outlet (78b) while the room temperature liquid stored in the receiver (77) It is configured to repeat the operation of evaporating through heat exchange with the refrigerant, converting it to a low-temperature gaseous state, being discharged through the outlet (78b), and flowing into the compressor (2), and dividing it into equal parts by the auxiliary bypass line (5b). The liquid refrigerant being transferred flows into the inlet (77a) of the liquid receiver (77) constituting the double-tube heat exchanger (7c) and undergoes heat exchange with the foggy refrigerant moving inside the liquid separator (78) while being stored. Heat is taken away, cooled to a low temperature, and discharged through the outlet (77b) of the receiver (77). The low-temperature liquid refrigerant discharged through the outlet (77b) of the receiver (77) flows through the cooling refrigerant transfer line (9a). Accordingly, it is transferred to the suction side (41) of the refrigerant liquid pump (4a) and mixed with the room temperature liquid refrigerant discharged to the outlet line (32) of the main condenser (3a). ) A liquid refrigerant circulation method for supplying and circulating low temperature refrigerant to the suction side of a refrigerant liquid pump that increases pressure and circulates the refrigerant of a refrigeration system.