JPH1054617A - Air conditioner - Google Patents

Abstract

(57) [Summary] [Problem] HC constituting refrigeration cycle exceeding critical pressure
Efficient cooling performance is ensured by using a refrigerant other than the FC type. SOLUTION: The refrigerant discharged from the compressor 1 constitutes a refrigeration cycle that returns to the compressor 1 through the outdoor heat exchanger 3, the expansion device 5, and the indoor heat exchanger 7. As the refrigerant, a refrigerant flowing through the refrigeration cycle exceeding the critical pressure is used,
During the cooling operation, the refrigerant temperature at the outlet of the outdoor heat exchanger 3 is made lower than the critical point temperature by the refrigerant cooling means 19.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air conditioner using a refrigerant other than HCFC and CFC, which is considered to have a bad influence on the global environment.

[0002]

2. Description of the Related Art Generally, an air conditioner operates during a cooling operation.
The refrigerant discharged from the compressor constitutes a refrigeration cycle that returns to the compressor after passing through the outdoor heat exchanger, the expansion device, and the indoor heat exchanger. During the refrigeration cycle, when air passes between the fins of the indoor heat exchanger, heat exchange is performed with the refrigerant so that the cooled air is blown out from the discharge port. Become.

[0003]

In a cooling operation using a refrigerant other than HCFC and CFC, for example, CO ₂ , FIG.
As shown in (1), the refrigeration cycle may be constructed beyond the critical pressure, and the isotherm at the critical point temperature of 31 ° C. changes horizontally at the critical pressure.

For example, when the outside air temperature is higher than the critical pressure of 35 ° C., the heat radiation of the refrigerant in the air-cooled outdoor heat exchanger is extremely reduced, and the cooling performance is deteriorated. To receive.

In view of the above, the present invention has been made in view of the fact that it has been proved by data that the performance can be improved by lowering the refrigerant outlet temperature of the outdoor heat exchanger below the critical point temperature. It is another object of the present invention to provide an air conditioner capable of obtaining sufficient cooling performance even when a refrigerant constituting a refrigeration cycle exceeding a critical pressure is used.

[0006]

In order to achieve the above object, the present invention relates to a refrigeration cycle in which refrigerant discharged from a compressor passes through an outdoor heat exchanger, a throttle device, and an indoor heat exchanger and returns to the compressor again. In the air conditioner, the refrigerant is a refrigerant other than HCFC and CFC and flows through a refrigeration cycle exceeding a critical pressure, and at the time of cooling operation, the refrigerant temperature at the outlet of the outdoor heat exchanger is changed to the critical point temperature. A cooling unit for lowering the temperature is provided.

[0007] Carbon dioxide (CO ₂ ) is used as the refrigerant. Further, the refrigerant cooling means is constituted by a water heat source and a water flow control device.

Alternatively, air and water are used at the same time, or one of them is used. Alternatively, a cold storage material is used.

According to this air conditioner, the refrigerant discharged from the compressor constitutes a refrigeration cycle that returns to the compressor after passing through the outdoor heat exchanger, the expansion device, and the indoor heat exchanger. During this operation, heat exchange is performed between the air passing through the indoor heat exchanger and the refrigerant, and the air is cooled.
At the same time, the refrigerant at the outlet of the outdoor heat exchanger is cooled by the refrigerant cooling means and flows through the refrigeration cycle in a state where the temperature is lowered to or below the critical point temperature. Cooling performance is obtained.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be specifically described below with reference to FIGS.

In FIG. 1, 1 is a compressor, 3 is an outdoor heat exchanger, 5 is a throttle device, and 7 is an indoor heat exchanger. During the cooling operation, by switching the four-way valve 9, the refrigerant discharged from the compressor 1 passes through the four-way valve 9, as shown by the solid line, the outdoor heat exchanger 3, the expansion device 5, the indoor heat exchanger 7.
And a refrigeration cycle that returns to the compressor 1 again.
Alternatively, during the heating operation, the refrigerant discharged from the compressor 1 as indicated by the dotted line passes through the indoor heat exchanger 7,
A refrigeration cycle that returns to the compressor 1 through the expansion device 5 and the outdoor heat exchanger 3 is configured.

As the refrigerant, carbon dioxide (CO ₂ ) which exceeds the critical point temperature and forms a refrigeration cycle is used.

The compressor 1 functions to compress the refrigerant taken in from the suction port 1a and discharge it from the discharge port 1b as a high-temperature and high-pressure gas.

The outdoor heat exchanger 3 has a double pipe structure comprising an outer refrigerant pipe 11 and an inner water pipe 13 as shown in FIG. The refrigerant pipe 11 has a grooved surface 15 on the inner peripheral surface through which the refrigerant flows. The water pipe 13 has a large number of fins 17 on the outer periphery, and an inner peripheral surface through which water from the water heat source 19 flows is a grooved surface 21.

The water pipe 13 includes a water heat source 19, a throttle valve 23,
A circulation cycle is formed through the outdoor heat exchanger 3 and returning to the water heat source 19 again. The water heat source 19 can be any water, such as tap water, sewage, and groundwater.

During the cooling operation, the throttle valve 23 controls the operation of water based on a detection signal from the refrigerant temperature detection sensor 25 for detecting the refrigerant temperature at the outlet of the outdoor heat exchanger 3 and a detection signal from the outside air temperature detection sensor 27. It is a flow control device. For example, when the outside air temperature and the refrigerant temperature greatly exceed the critical pressure, the throttle valve 23 is fully opened to maximize the amount of water flowing through the water pipe 13 so that heat exchange with the refrigerant is performed. Control of the amount of water flowing through the water pipe 13 is performed based on the signal.

On the other hand, the expansion device 5 constituting the refrigeration cycle
Is a capillary tube, which functions to convert the refrigerant into a low-temperature and low-pressure gas by a throttling action during passage.

The indoor heat exchanger 7 includes a refrigerant pipe 1 through which a refrigerant flows.
1 is provided with a large number of fins (not shown), and a blower fan 2 for passing wind between the fins.
9.

According to the air conditioner configured as described above, during the cooling operation, the refrigerant discharged from the compressor 1 passes through the outdoor heat exchanger 3, the expansion device 5, and the indoor heat exchanger 7, and is compressed again. A refrigeration cycle returning to the machine 1 is configured. During this operation, heat exchange is performed between the refrigerant and the air passing between the fins of the indoor heat exchanger 7, and the cooled air is blown out from the outlet.

At the same time, the outside air temperature and the refrigerant temperature of the outdoor heat exchanger 3 are detected by the detection sensors 25 and 27, and the opening amount of the throttle valve 23 is controlled based on the detection signals. That is, when the outside air temperature and the refrigerant temperature greatly exceed the critical point temperature,
The throttle valve 23 is fully opened, and the amount of water flowing through the water pipe 13 becomes maximum. Thereby, in the outdoor heat exchanger 3, heat exchange is performed between the refrigerant flowing through the refrigerant pipe 11 and the refrigerant outlet temperature falls below the critical point temperature, and the refrigerant temperature is optimized by the refrigerant temperature detection sensor 25. Managed by value.

As a result, as shown in the theoretical calculation results in FIG. 2, when the condenser pressure is at the critical pressure level (7.3 MPa), when the outlet temperature of the outdoor heat exchanger 3 is about 35 ° C., the HCFC refrigerant, R22 Although the theoretical energy consumption efficiency (ratio between cooling capacity and compressor work) is the lowest in comparison with the above, for example, when the outlet temperature is reduced to about 20 degrees, the energy consumption efficiency is greatly improved compared to R22. It can be seen that it can be achieved.

In this case, when the condenser pressure of carbon dioxide (CO ₂ ) becomes 8.5 MPa or more, the energy consumption efficiency becomes R
Therefore, it is desirable to use the condenser under a condition of 8.5 or less.

When a water heat source 19 higher than the outside air temperature is used in the heating operation, the throttle valve 23 is opened to apply heat to the refrigerant from the high-temperature water heat source 19 to increase the temperature of the evaporated refrigerant. As a result, heating efficiency can be improved by increasing the evaporation pressure.

FIG. 4 shows another embodiment of the outdoor heat exchanger 3.

That is, the outdoor heat exchanger 3 has a double pipe structure including a refrigerant pipe 11 through which a refrigerant flows and a water pipe 13 through which water flows as shown in FIG. A large number of fins 33 through which air is passed by the blower fan 31 are provided on the outer circumference of the refrigerant pipe 11, and the grooved surface 15 is formed on the inner inner circumference to increase the heat transfer area. The water pipe 13 constitutes a refrigeration cycle that returns from the water heat source 19 and the throttle valve 23 to the water heat source 19 through the outdoor heat exchanger 3 and has a large number of fins 17 on the outer periphery. The heat transfer area is increased by forming the grooved surface 21 on the inner peripheral surface through which the air flows.

The blower fan 31 includes an outside air temperature detection sensor 27.
Alternatively, on / off control is performed based on a detection signal from the refrigerant temperature detection sensor 25. For example, when the outside air temperature is equal to or lower than the critical point temperature, the blower fan 31 is turned on and the throttle valve 23 is turned on.
Is controlled to be closed.

When the temperature is equal to or higher than the critical point temperature, the blower fan 31 is turned off and the throttle valve 23 is opened, and the opening amount of the throttle valve 23 is controlled according to the temperature.

The other components are the same as those shown in FIG.

Therefore, according to this embodiment, for example, in the cooling operation, when the outside air temperature is equal to or lower than the critical point temperature, the throttle valve 23 is closed in the outdoor heat exchanger 3 by the outside air temperature detection sensor 27 and the air is blown. The fan 31 is turned on, heat is exchanged with the refrigerant only by the air heat source by the blower fan 31, and the temperature of the refrigerant is lowered to the critical point temperature or lower.
As a result, air that is cheaper than water can be used effectively, energy efficiency can be improved, and efficient cooling performance can be obtained.

On the other hand, when the outside air temperature is equal to or higher than the critical point temperature, the blower fan 31 is turned off and the throttle valve 23 is opened, while the outdoor heat exchanger 3 performs heat exchange between water and the refrigerant. To lower the refrigerant temperature below the critical point temperature. Thereby, energy consumption efficiency is improved, and efficient cooling performance is obtained.

FIG. 6 shows another embodiment of the outdoor heat exchanger.

That is, the first outdoor heat exchanger 37 is provided upstream of the refrigerant circuit during the cooling operation, and the second outdoor heat exchanger 39 is provided downstream thereof.

The first outdoor heat exchanger 37 is composed of a refrigerant pipe (not shown) provided with a large number of fins on the outer periphery and a blower fan 41 for passing air between the fins of the refrigerant pipe. Air heat exchanger.

The blower fan 41 includes an outside air temperature sensor 2
7 and the detection signal from the refrigerant temperature detection sensor 25, for example, when the outside air temperature and the refrigerant temperature are equal to or higher than the critical point temperature, the control is weak.

The second outdoor heat exchanger 39 is a double-tube heat exchanger for water. The refrigerant pipe 11, the water pipe 13, the water heat source 19, the throttle valve 23, and the like constituting the heat exchanger for water are the same as those in FIGS. 1 and 3 and are denoted by the same reference numerals and will not be described in detail. Further, other components are the same as those in FIG.

Therefore, according to this embodiment, for example, if the outside air temperature is equal to or higher than the critical point temperature and the refrigerant temperature is equal to or higher than the external air temperature, the heat exchange of the refrigerant by the air heat source by the blower fan 41 and the water heat source This is performed in combination with the heat exchange of the refrigerant by 19, and the outlet temperature of the refrigerant is lowered to the critical point temperature or lower. As a result, since the heat of the refrigerant having a temperature equal to or higher than the outside air temperature is lost to the air, the frequency of use of water is further reduced, the energy consumption efficiency is improved, and efficient cooling performance is obtained. When the outside air temperature is equal to or lower than the critical temperature of the refrigerant, by closing the throttle valve 23 of the water heat source 19, an inexpensive operation similar to that of a conventional pneumatic air conditioner can be performed.

FIGS. 7 and 8 show another embodiment of the outdoor heat exchanger.

That is, the water heat source 19 constituting the circulation cycle
Water tank 45 which is provided in the water pipe 13 having the water and the throttle valve 23 and stores a certain amount of water 43 serving as a cold storage material for cooling the refrigerant.
The outdoor heat exchanger 51 is constituted by a continuous refrigerant pipe 47 provided in the water tank 45 and arranged substantially in parallel, and a number of fins 49 provided in the refrigerant pipe 47.

The water tank 45 is covered with a heat insulating material so as not to be affected by the outside temperature. For example, in the summer season, storing water in a time period when the water temperature is low allows a large amount of heat storage energy to be stored. Can be secured.

The other components are the same as those in FIG.
The same reference numerals are given and the detailed description is omitted.

According to this embodiment, even when the outside air temperature is significantly higher than the critical point temperature, or when the load fluctuation is large, the coolant temperature is reduced by the water 43 provided in the water tank 45. It is possible to keep the temperature below the critical point temperature. Thereby, energy consumption efficiency can be improved, and efficient cooling performance can be obtained.

Note that paraffin having a large latent heat may be used in place of the water 43 serving as a cold storage material. By using this paraffin, a large amount of latent heat can be used, and the container for containing the paraffin can be made smaller in size than the water tank 45, so that the entire outdoor heat exchanger 51 can be made compact.

Also, as shown in FIG. 9, water from a water heat source 19 such as tap water is sent to the bottom by opening the on-off valve 52 instead of the water tank 45, and the water can be taken out to the hot water supply unit 54 from above. A water heater 56 may be used.

That is, on the bottom side of the electric water heater 56, the refrigerant pipe 47 and the cooling fins 4
9 is disposed. Heat exchange unit 5
8, one of the refrigerant pipes 47 extends outward from the electric water heater 56, and the expansion device 5 and the other are connected to the electric water heater 56.
, And are connected to the four-way valve 19, respectively. Above and below the heat exchange unit 58, a first electric heater and second electric heaters H-1 and H-2, which are turned on by the late-night power W, are provided. 5
8 and above.

The other components are the same as those shown in FIG.

Therefore, according to this embodiment, by switching the four-way valve 9, the cooling operation indicated by the solid line and the heating operation indicated by the dotted line can be performed. On the other hand, in the summer, when the cooling operation season has started, the hot water supply load decreases,
Of the second electric heaters H-1 and H-2, only the second electric heater H-2 located above the heat exchange section 58 is used and used as an electric water heater.

Thus, the hot water heated by the second electric heater H-2 rises upward and is stored. on the other hand,
On the bottom side, a low water temperature state is secured throughout the day due to the water sent from the water heat source 19, so that the refrigerant temperature can be lowered to the critical point temperature or lower by passing through the heat exchange unit 58 during the cooling operation. As a result, the energy consumption efficiency is improved, and since the electric water heater 56 is used, equipment such as a water tank is not required, and the entire system can be made compact. In addition, the use of midnight power is very favorable in terms of cost.

FIG. 10 shows another embodiment of the outdoor heat exchanger.

That is, the first, second and third outdoor heat exchangers 51, 53 and 55 are provided in the refrigeration cycle. The first outdoor heat exchanger 51 is a water heat exchanger that uses water for heat exchange with the refrigerant. As shown in FIG. 3, the first outdoor heat exchanger 51 has an outer refrigerant pipe 11 through which the refrigerant flows and an inner refrigerant pipe 11 through which the water flows. The water pipe 13 has a double pipe structure.

The water pipe 13 has a large number of fins 17 on the outer periphery, and the inner peripheral surface through which water from the water heat source 19 flows has a grooved surface 21.
The aim is to increase the heat transfer area. The water pipe 13 passes through the water heat source 19, the throttle valve 23, the first outdoor heat exchanger 51,
A circulation cycle returning to the water heat source 19 is constituted again, and the outer periphery is covered with a heat insulating material so that the influence of the outside air temperature is suppressed even below the freezing point.

The second outdoor heat exchanger 53 is a heat exchanger for air in which heat exchange with the refrigerant is performed by air, and has a blower fan 57 for passing air through a refrigerant pipe having fins. It is an outdoor heat exchanger for cooling.

The third outdoor heat exchanger 55 is a heat exchanger for air in which heat exchange with the refrigerant is performed by air, and has a blower fan 60 for passing air through a refrigerant pipe having fins. It is an outdoor heat exchanger for heating.

The first, second and third outdoor heat exchangers 51 and 5
3, 55 are open / close valves 59, 61,
Each of the on-off valves 59, 61, and 63 has a bypass circuit 65, 63, and 63. The on-off valves 59, 61, and 63 correspond to the cooling operation mode, the heating operation mode, and the level of the outside air in response to a signal from a control unit (not shown). Combined opening and closing is performed. Thus, during the cooling operation, the refrigerant flows as indicated by the solid line or as indicated by the solid line, and during the heating operation, the refrigerant flows as indicated by the broken line or as indicated by the arrow, and the refrigerant flows upstream with respect to the first heat exchanger 51. The second outdoor heat exchanger 53 has a structure in which the third outdoor heat exchanger 55 is arranged on the upstream side during the heating operation. Note that the outdoor heat exchangers 51 and 53 may be configured with two paths in one outdoor heat exchanger. Also, instead of the bypass circuits 65, 67, 69 and the on-off valves 59, 61, 63, the blowers 57, 60 and the throttle valve 23 of the water circuit are turned on and off.
The OFF control may be used.

The other components are the same as those shown in FIG. 1, and thus the same reference numerals are given and the detailed description is omitted.

According to this embodiment, cooling: when the outside air temperature is equal to or higher than the critical point temperature, the cycle control is performed as shown by the solid line in FIG. Accordingly, heat can be radiated from the high-temperature refrigerant discharged from the compressor 1 to the outside air temperature, and the outside air can be effectively used for heat radiation. Therefore, the heat load of the water heat source 19 can be reduced, and the cost of water that is higher in cost than air can be reduced. Can be more efficient. When the outside air temperature is equal to or lower than the critical point temperature, the heat of the refrigerant is released to the outside air in the outdoor heat exchanger similarly to the conventional air-type air conditioner (operation indicated by the solid line in FIG. 10).

Heating: When the outside air temperature is about 5 to 7 ° C. or lower, the outdoor heat exchanger absorbs heat using both the outside air and water (operation indicated by a broken line in FIG. 10). The rotation of the blower fan 60 is adjusted to a level that does not cause frost on the third outdoor heat exchanger 55, and the refrigerant is cooled to 1 by the outside air.
Heat the part. Thereafter, the refrigerant is completely heated by the water heat source 19, vaporized, and returned to the compressor 1. 1 air heat source
Because of the use of parts, the heat load of water can be reduced, and the amount of water that is more costly than air can be reduced, which is efficient. When the outside air temperature is about 5 to 7 ° C. or higher, the refrigerant is heated by the outside air in the outdoor heat exchanger in the same manner as a normal air heat source air conditioner (FIG. 10).
Dashed line operation).

FIG. 11 shows another embodiment of the outdoor heat exchanger.

That is, the first, second and third outdoor heat exchangers 71, 72 and 73 are provided in the refrigeration cycle. The first outdoor heat exchanger 71 is a heat exchanger that uses water and a cold storage material for heat exchange with the refrigerant. As shown in FIG. 3, the first outdoor heat exchanger 71 has an outer refrigerant pipe 11 through which the refrigerant flows and an inner refrigerant pipe 11 through which the water flows. The water pipe 13 has a double pipe structure.

The heat transfer area of the refrigerant pipe 11 is increased by using the inner peripheral surface through which the refrigerant flows as the grooved surface 15. Water pipe 13
Has a large number of fins 17 on the outer periphery, and uses the inner peripheral surface through which water from the water heat source 19 flows as a grooved surface 21 to increase the heat transfer area. The water pipe 13 constitutes a circulation cycle that passes through the water heat source 19, the throttle valve 23, the first outdoor heat exchanger 71, and returns to the water heat source 19 again. The first outdoor heat exchanger 71 is a paraffin that serves as a cold storage material. Constitute a container filled with.

The first outdoor heat exchanger 71 is entirely covered with a heat insulating material so that it is not affected by the outside air temperature.
In addition to normal power, the compressor 1
, A refrigeration cycle indicated by a one-dot chain line is configured at the time of the cold storage operation of the air conditioner, and the low-temperature and low-pressure gas from the expansion device 5 opens the on-off valve 75 so that the inside of the first outdoor heat exchanger 71 is opened. It has a structure including a bypass circuit 77 for flowing and cooling the cold storage material.

The second outdoor heat exchanger 72 is an air heat exchanger for performing heat exchange with the refrigerant by air, and has a blower fan 79 for passing air through a refrigerant pipe having fins. It is an outdoor heat exchanger for cooling.

The third outdoor heat exchanger 73 is a heat exchanger for air that exchanges heat with the refrigerant by air, and has a blower fan 81 for passing air through a refrigerant pipe having fins. It is an outdoor heat exchanger for heating.

The first, second and third outdoor heat exchangers 71 and 7
2, 73 are each open / close valve 83, 85,
An on-off valve 95 provided between each of the on-off valves 83, 85, 87 and the first and second outdoor heat exchangers 71, 72 is provided with a cooling circuit. In accordance with the operation mode, the heating operation mode, and the level of the outside air temperature, combined opening and closing are performed by a signal from a control unit (not shown). Thereby, at the time of the cooling operation and the heating operation, the flow of the refrigerant shown by the solid line and the dotted line is secured as shown in FIG. 10, and the second flow is provided upstream of the first heat exchanger 71. The outdoor heat exchanger 72 has a structure in which a third outdoor heat exchanger 73 is arranged on the upstream side during the heating operation.

The other components are the same as those shown in FIG. 1, and thus are denoted by the same reference numerals and will not be described in detail.

According to this embodiment, in addition to the effect shown in FIG. 10, the cold storage material filled in the first outdoor heat exchanger 71 can be stored with the low-cost late-night power W1. The operation cost can be reduced and the water heat source 1
In combination with 9, the temperature of the refrigerant can be more reliably lowered to the critical point temperature or lower.

FIG. 12 shows another embodiment of the outdoor heat exchanger.

That is, the first, second, and third outdoor heat exchangers 97, 98, and 99 are provided in the refrigeration cycle. The first outdoor heat exchanger 97 uses the electric water heater 101,
Water from a water heat source 103 such as tap water is sent into the lower part of the electric water heater 101 by opening the on-off valve 105 and can be taken out to the hot water supply unit 107 from above.

On the bottom side of the electric water heater 101, a heat exchanging section 109 composed of a refrigerant pipe and cooling fins provided on the refrigerant pipe is disposed. One of the refrigerant pipes serving as the heat exchanging section 109 is: The second outdoor heat exchanger 98 is extended outward from the electric water heater 101 via an on-off valve 95, and the other is connected to the third outdoor heat exchanger 99 extended outward from the electric water heater 101, respectively. doing.

Above and below the heat exchange section 109, the late-night power W2
Are provided, a first electric heater H-1 and a second electric heater H-2 are provided, and the upper second electric heater H-2 is located above and away from the heat exchange unit 109.

The second and third outdoor heat exchangers 98, 9
8 and the other components are the same as those in FIG.

Therefore, according to this embodiment, FIG.
0, the following effects are obtained in addition to the effects of FIG. That is, in the summer when the season of the cooling operation is started, only the second electric heater H-2 located above the heat exchanging section 109 is used among the first and second electric heaters H-1 and H-2 to use the electric hot water. Vessel 10
Use as 1.

As a result, the warm water heated by the second electric heater H-2 rises upward, and the bottom side is the water heat source 10.
Since a low water temperature state is ensured throughout the day by the water sent from 3, the refrigerant temperature is lowered to the critical point temperature or lower by passing through the heat exchange unit 109 during the cooling operation. In this case, when the outside air temperature is lower than the critical point temperature, the air flows as indicated by the solid line, and when the outside air temperature is higher than the critical point temperature, the air flows as indicated by the solid line, so that the energy consumption efficiency is improved and the electric water heater 101 is improved. Therefore, equipment such as a water tank is unnecessary, and the whole system can be made compact.

During the heating operation, the first electric heater H-
By the hot water at the bottom of the electric water heater 101, heat is given to the refrigerant in the heat exchange section 109, and efficient heating operation is possible.

[0074]

As described above, according to the air conditioner of the present invention, even if a refrigerant constituting a refrigeration cycle exceeding the critical pressure is used, the refrigerant temperature is kept below the critical point temperature by the refrigerant cooling means. Since it can be reduced, energy consumption efficiency can be improved and efficient cooling performance can be obtained. As a result, the selection range of the refrigerant other than the HCFC and the CFC system is expanded.

[Brief description of the drawings]

FIG. 1 is a circuit diagram of an entire air conditioner according to the present invention.

FIG. 2 is an explanatory diagram of the theoretical energy consumption efficiency of each refrigerant at the outdoor heat exchanger outlet temperature.

FIG. 3 is a sectional view of an outdoor heat exchanger having a double pipe structure.

FIG. 4 is a circuit diagram similar to FIG. 1, showing another embodiment of the outdoor heat exchanger.

FIG. 5 is a cross-sectional view of the outdoor heat exchanger of FIG.

FIG. 6 is a circuit diagram similar to FIG. 1, showing another embodiment of the outdoor heat exchanger.

FIG. 7 is a circuit diagram similar to FIG. 1, showing another embodiment of the outdoor heat exchanger.

8 is a schematic cutaway explanatory view of the outdoor heat exchanger of FIG. 7;

FIG. 9 is a circuit diagram similar to FIG. 1 in which the outdoor heat exchanger is an embodiment using an electric water heater.

FIG. 10 is a circuit diagram similar to FIG. 1, showing another embodiment of the outdoor heat exchanger.

FIG. 11 is a circuit diagram similar to FIG. 1, showing another embodiment of the outdoor heat exchanger.

FIG. 12 is a circuit diagram similar to FIG. 1, showing another embodiment of the outdoor heat exchanger.

FIG. 13 is an explanatory diagram showing a refrigeration cycle when pressure is on the vertical axis and enthalpy is on the horizontal axis.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Compressor 3 Outdoor heat exchanger 5 Throttle device 7 Indoor heat exchanger 19 Water heat source (refrigerant cooling means)

Claims (5)

[Claims] 1. An air conditioner comprising a refrigeration cycle in which refrigerant discharged from a compressor passes through an outdoor heat exchanger, a throttling device, and an indoor heat exchanger and returns to a compressor again, wherein the refrigerant includes HCFC and CFC. In addition to using refrigerant flowing beyond the critical pressure and flowing through the refrigeration cycle outside the system, during cooling operation,
An air conditioner comprising a refrigerant cooling means for lowering a refrigerant temperature at an outlet of an outdoor heat exchanger below a critical point temperature. 2. The air conditioner according to claim 1, wherein the refrigerant is carbon dioxide (CO ₂ ). 3. The air conditioner according to claim 1, wherein the refrigerant cooling unit includes a water heat source and a water flow control device. 4. The air conditioner according to claim 1, wherein the refrigerant cooling means uses air and water at the same time or selects one of them. 5. The air conditioner according to claim 1, wherein a regenerative material is used for the refrigerant cooling means.