JPH06307750A - Controller for refrigerator with heating function - Google Patents

Abstract

PURPOSE:To provide a refrigerator with a heating function in which a constant- temperature control can be executed irrespective of seasons. CONSTITUTION:An evaporator 6 and a heater core 7 are disposed in a refrigerator, and a flow rate of heating medium which flows to the core 7 is variably set by a three-way valve 21. A target diffusing temperature of the air to be diffused to a space to be temperature regulated is calculated by a suction air temperature to be sucked to the refrigerator and a set temperature set by a temperature setter, and an opening of the valve 21 is so regulated as to converge the diffused air temperature to be diffused from the refrigerator to the target diffusing temperature when the suction air temperature is converted to a predetermined set temperature range. Since the suction temperature is converged to the set temperature and simultaneously the diffused temperature is also converged to the target temperature, an irregularity in a temperature distribution of the space to be temperature regulated is suppressed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control unit for a refrigerating unit with a heating function, in which a refrigerating unit for refrigerating a load of food or the like has a heating function.

[0002]

2. Description of the Related Art As a refrigeration unit having a heating function taken into consideration, one disclosed in Japanese Patent Laid-Open No. 145517/1983 is known. This forms a cooling unit by a cooling heat exchanger of a cooling cycle and a blower that blows the air heat-exchanged by the cooling heat exchanger into an air-conditioned space. A heating heat exchanger that uses cooling water as a heat source, and a blower that blows the air that has been heat-exchanged by the heating heat exchanger to the air-conditioned space form a heating unit, and each of these units is formed. It is arranged in a freezer.

[0003]

However, in the above-mentioned structure, since the refrigerating and warming equipments are provided independently, a lot of space is required, and the switching between cooling and warming is performed electromagnetically. Since it must be controlled manually by turning the valve on / off, in the case of constant temperature control of the load in the middle of spring or autumn, it has to rely on the switching control based on the judgment of the driver, and the temperature control cannot be performed well. was there.

In view of this, the present invention provides a refrigerating unit with a heating function, which has a heating function incorporated in the refrigerating unit to automatically perform cooling and heating control so that constant temperature control can be performed regardless of the season. Is an issue.

[0005]

SUMMARY OF THE INVENTION However, the gist of the present invention is that a unit fan, an evaporator forming a part of a cooling cycle, and a heater core forming a part of a heating cycle are arranged in a unit case. A valve for varying the flow rate of the heating medium flowing into the heater core, a suction temperature detection sensor for detecting the temperature of the air sucked into the refrigeration unit, and an outlet temperature detection sensor for detecting the temperature of the air blown out from the unit case. And a temperature setting device that sets the temperature of the air-conditioned space, and the temperature-controlled space based on at least the suction temperature detected by the suction temperature detection sensor and the set temperature set by the temperature setting device. A target outlet temperature calculating means for calculating a target temperature of the air blown to the air outlet, and until the suction temperature converges within a predetermined set temperature range, When the valve is fully opened or closed based on the suction temperature detected by the suction temperature detection sensor and the set temperature set by the temperature setting device, and the suction temperature converges within a predetermined set temperature range, And a valve opening control means for adjusting the opening of the valve so that the outlet temperature detected by the outlet temperature sensor converges to the target temperature.

[0006]

Therefore, until the suction temperature converges within the predetermined set temperature range, the flow of the heating medium into the heater core is adjusted by fully opening or closing the valve, and the suction temperature is quickly brought close to the set temperature. Then, when the intake temperature converges within a predetermined set temperature range, the valve opening is adjusted so that the outlet temperature detected by the outlet temperature sensor converges to the target outlet temperature calculated by the target outlet temperature calculating means. The flow rate into the heater core is controlled. Thus, in the latter half when the suction temperature converges to the set temperature,
Since the outlet temperature is also made to converge to the target temperature,
The variation in the temperature distribution of the temperature-controlled space can be suppressed as much as possible, and the temperature of the temperature-controlled space can be kept constant. Therefore, the above-mentioned problems can be achieved.

[0007]

Embodiments of the present invention will be described below with reference to the drawings.

In FIG. 1, a vehicle 2 having a freezer 1 is shown, and a freezing unit 3 with a heating function is fixedly installed, for example, in front of the ceiling of the freezer 1. This refrigeration unit 3
Is a unit case 4 as seen in FIGS.
The unit fan 5 is arranged at the most upstream side of the inside, the evaporator 6 is arranged at the rear side of the evaporator 6, and the heater core 7 is further arranged at the rear side of the evaporator 6.
The temperature of the air sucked from the air is adjusted by the evaporator 6 and the heater core 7, and the air is sent into the freezer from the outlet 4a provided at the most downstream portion.

The unit fan 5 is of a twin type in which a sirocco fan 9 is connected to both ends of the drive shaft of the motor 8, and two unit fans 5 are arranged along the wind-in side end surface of the evaporator 6 to rotate the motor 8. Thereby sucking the air in the freezer and blowing it to the evaporator 6.

As shown in FIG. 4, the evaporator 6 constitutes a part of the cooling cycle by sequentially connecting the accumulator 10, the compressor 11, the condenser 12, the liquid tank 13 and the expansion valve 14 by piping. ,
When the compressor is in operation, it cools the air passing through it. That is, if the compressor 11 is operating (ON), the refrigerant discharged from the compressor 11 is radiated by the condenser 12 to be condensed and liquefied, and the liquid tank 13 is separated into gas and liquid, and then the expansion valve 14
Becomes low-temperature low-pressure refrigerant, and the evaporator 6 absorbs heat from the air passing therethrough and evaporates.

In addition, in a portion facing the capacitor 12,
A condenser fan 40 that cools the condenser 12 is provided.

The heater core 7 fully reheats all the air that has passed through the evaporator 6, and the engine 1
The cooling water of No. 5 is used as the heat source. As shown in FIG. 4, the circulation path of the engine cooling water is formed by sequentially connecting the pressure pump 16 for pumping the cooling water from the engine 15, the heater core 7 in the refrigerating unit, and the heater core 17 provided on the cab side by pipe connection. And the engine cooling water sent to the radiator 18 and cooled there to cool the engine 15
And a second route to return to. The second path is provided with an on-off valve 19 that opens this path when the cooling water has a temperature higher than a predetermined temperature. In addition, the bypass passage 2 that bypasses the heater core 7 for the refrigeration unit is provided in the first passage.
0 is formed, and a 3-way valve 21 that adjusts the ratio of the cooling water flowing to the heater core side and the cooling water flowing in the bypass passage is provided at the branching start point of the bypass passage 20.

FIG. 5 shows a specific example of the structure of the three-way valve 21. The three-way valve 21 has an inflow port 2 through which cooling water flows.
1a, a heater core side outflow port 21b connected to the heater core side passage, and a bypass side outflow port 21c connected to the bypass passage 20. The heater core side outflow port 21b and the bypass side outflow port 21c are separated. The valve body 22 is provided in the part. This valve body 22
For example, the actuator 2 (shown in FIG. 4) may be connected to the rod 2
4 and is movable in the extending direction of the heater core side outflow port 21b, and is formed in the vicinity of the branch point of the heater core side outflow port 21b.
The outflow port can be completely closed by abutting against, and the bypass side outflow port 21c can be completely closed by the side surface of the valve body 22 when it is farthest from the valve seat portion 25.
Then, from the state of the opening degree of 0% in which the heater core side outflow port 21b is closed and only the bypass side outflow port 21c is opened, the opening degree 100 in which the bypass side outflow port 21c is closed and only the heater core side outflow port 21b is opened. The valve opening can be continuously adjusted depending on the state of%.

A suction air temperature sensor 26 for detecting the temperature of the air sucked into the unit fan 5 is provided at the air inlet 5a of the unit fan 5, and the unit 4 is provided near the air outlet 4a of the refrigeration unit 3. A blown air temperature sensor 27 for detecting the temperature of blown air is provided,
Detection signals from the temperature sensors 26 and 27 are input to the control unit 28.

The control unit 28 includes an input circuit including an A / D converter and a multiplexer, a timer, and an RO.
A well-known device having an arithmetic processing circuit including M, RAM, CPU, etc., and an output circuit including I / O port, etc., from a temperature setter 29 for setting the temperature in the freezer in addition to the input signal from the sensor. Is also input, these signals are arithmetically processed according to a predetermined program, and drive circuits 30a to 30
Through e, the on / off of the compressor 11, the blowing capacity of the condenser fan 40 and the unit fan 5, the on / off of the pressure pump 16 and the actuator 23 for moving the three-way valve 21 are controlled.

In FIG. 6, the control unit 28
A specific control operation example by is shown as a flow chart, and description will be given below based on this flow chart.

The control unit 28 executes step 5
0, under the condition that the refrigeration unit 3 is operating,
Suction temperature (T_SUC) And set temperature (T_PTC) Difference (ΔT
= T _SUC-T_PTC) Is calculated. And based on this difference
Then, in step 52, the compressor 11 is turned on / off.
The condenser fan 40 is turned on in step 54.
ON / OFF control is performed, and in step 56, the unit fan 5
The blowing capacity of the pump 1 is controlled, and in step 58, the pressure pump 1
6 is on / off controlled, and in step 60, the three-way valve 21
The opening degree of is controlled.

More specifically, as shown in FIG. 7, in the compressor 11, the difference (ΔT = T _SUC -T _PTC ) between the suction temperature and the set temperature is, for example, +1.
If it is above, it goes from off to on, and if it is below 0,
It turns from on to off. In the condenser fan 40, for example, when ΔT is +1 or more, it is turned on and when it is 0 or less, it is turned on. In the unit fan 5, for example, when ΔT = 0, the high speed rotation (HI) changes to the low speed rotation (LOW), and | ΔT |
When ≧ 1.5, the low speed rotation (LOW) is changed to the high speed rotation (HI). Further, in the pressure feed pump 16, for example, when the three-way valve opening degree is 0%, it is turned on, and when the three-way valve opening degree is 5% or more, it is turned on.

The details of the opening control of the three-way valve are shown in FIG. 8, and in step 602, | ΔT = T _SUC −T
It is determined whether or not _PTC | is a predetermined value α or less (for example, 3 ° C. or less), and it is determined whether or not the suction temperature has converged to the set temperature to some extent. In this step, | ΔT
When it is determined that | ≦ 3, the routine proceeds to step 604, where the target outlet temperature (X _M ) to be blown into the freezer is calculated. The target outlet temperature (X _M ) can be calculated by various methods. For example, it is desirable to calculate the target outlet temperature (X _M ) from the suction temperature (T _SUC ) and the set temperature (T _PTC ) based on the mathematical formula 1.

[0020]

[Formula 1] X _M = T _PTC −ΔT−Σβ * ΔT

Here, β is an arithmetic constant preset in the experiment.

After the target outlet temperature (X _M ) is calculated, the routine proceeds to step 606, where the outlet air temperature sensor 2
The blow-off temperature (T _BLOW ) detected in 7 is set to the target blow-out temperature (X
Proportional-integral control (PI control) for converging to _M ) is performed. Note that the PI control is a well-known method, and a description thereof will be omitted.

In summary, the temperature control (suction control) that reduces the difference between the suction temperature and the set temperature until the suction temperature converges within the predetermined set temperature range (within ± 3 degrees with respect to the set temperature). Control) is performed. That is, when the suction temperature is significantly higher than the set temperature, it is necessary to quickly cool the inside of the freezer toward the set temperature. Therefore, the unit fan 5 and the cooling cycle are operated to promote the cooling of the air by the evaporator 6. , The pressure feed pump 16 is turned off, and all the cooling water is guided to the bypass passage 20, so that the refrigeration unit 3
Do not heat the inner heater core 7. Further, when the suction temperature is significantly lower than the set temperature, it is necessary to quickly warm the inside of the freezer toward the set temperature. Therefore, the operation of the cooling cycle is stopped and the cooling of the air in the evaporator 6 is stopped. Guide all the cooling water to the heater core 7,
The pressure pump 16 is turned on to heat the air introduced into the refrigeration unit 3.

When the suction temperature converges within a set temperature range, stable control (blowout control) is performed so that the blowout temperature also converges to the target temperature. That is, the opening degree of the three-way valve 21 is PI-controlled so that the deviation of the outlet temperature from the target temperature is fed back by feeding back the outlet temperature.

As a result, the suction temperature is made to converge to the set temperature and the outlet temperature is made to converge to the target temperature, so that it is possible to suppress variations in the temperature distribution inside the refrigerator as much as possible regardless of the season.

[0026]

As described above, according to the present invention,
Even if the suction temperature converges to the set temperature, when the suction temperature converges within the predetermined set temperature range, the opening degree of the valve is changed to converge the outlet temperature to the target outlet temperature. Variations in the temperature distribution in the controlled space are automatically suppressed, and the temperature in the controlled space can be kept constant regardless of the season.

[Brief description of drawings]

FIG. 1 is a diagram showing a vehicle equipped with a refrigeration unit with a heating function according to the present invention.

FIG. 2 is a side sectional view showing a schematic configuration of a refrigeration unit with a heating function.

FIG. 3 is a plan sectional view showing a schematic configuration of a refrigeration unit with a heating function.

FIG. 4 is a schematic configuration diagram showing a control device of a refrigeration unit with a heating function.

FIG. 5 is a cross-sectional view showing a three-way valve used in the control device for the refrigeration unit with a heating function.

FIG. 6 is a flowchart showing an example of control operation of a control device for a refrigeration unit with a heating function.

FIG. 7 is a characteristic diagram showing an example of control operation of the control device for the refrigeration unit with a heating function.

FIG. 8 is a flowchart showing an example of control operation of a three-way valve used in the control device for the refrigeration unit with a heating function.

[Explanation of symbols]

 3 Refrigeration Unit 6 Evaporator 7 Heater Core 21 3 Way Valve 26 Suction Temperature Sensor 27 Blowout Temperature Sensor 29 Temperature Setter

Claims (1)

[Claims] 1. A unit fan, an evaporator forming a part of a cooling cycle, and a heater core forming a part of a heating cycle are arranged in a unit case, and a valve for varying a flow rate of a heating medium flowing into the heater core, It has a suction temperature detection sensor for detecting the temperature of the air sucked into the refrigeration unit, an outlet temperature detection sensor for detecting the temperature of the air blown out from the unit case, and a temperature setter for setting the temperature of the air-conditioned space. Then, at least the target outlet temperature calculating means for calculating the target temperature of the air blown into the temperature controlled space based on the inlet temperature detected by the inlet temperature detection sensor and the set temperature set by the temperature setter, Until the suction temperature converges within a predetermined set temperature range, the suction temperature detected by the suction temperature detection sensor and the temperature setting In the case where the valve is fully opened or fully closed based on the set temperature set in, and the suction temperature converges within a predetermined set temperature range, the blowing temperature detected by the blowing temperature sensor is the target temperature. And a valve opening degree control means for adjusting the opening degree of the valve so that the refrigeration unit has a heating function.