JP2021127896A - Cooling device - Google Patents

Abstract

To avoid abnormal pressure or breakage of a compressor by varying an opening degree of an electronic expansion valve at the time of a cooling operation according to a cooling load.SOLUTION: A cooling device comprises a valve opening control part 23 for cooling a storage 10 to a desired temperature condition by adjusting an opening degree of an electronic expansion valve 12 so that an inside temperature of the storage 10 approaches to a preset target temperature, and adjusting a flow rate of a refrigerant to an evaporator 13 arranged in the storage 10 in the case of a normal operation, and for stopping supply of the refrigerant to the evaporator 13 by closing the electronic expansion valve 12 in the case of a defrosting operation after the normal operation. The valve opening control part 23 adjusts the opening degree by setting the opening degree of the electron expansion valve 12 from a temperature of outside air, in which a compressor 15 for sucking the refrigerant from the evaporator 13 and compressing it is provided, and valve opening setting information 24b in the case of a cooling operation after the defrosting operation until the next normal operation.SELECTED DRAWING: Figure 1

Description

The present invention cools the storage to a desired temperature state by adjusting the opening degree of the electronic expansion valve based on the internal temperature of the storage and adjusting the flow rate of the refrigerant with respect to the evaporator arranged in the storage. It is related to the cooling device to be used.

For example, in a showcase where products are displayed and sold in a cooled state, an evaporator is provided inside the storage, and a compressor, a condenser, and an electronic expansion valve are provided outside the storage, and these evaporators are provided. , A compressor, a condenser, and an electronic expansion valve are sequentially connected by pipes to form a cooling device that circulates the enclosed refrigerant.

In such a cooling device, in the case of normal operation, the opening degree of the electronic expansion valve is adjusted based on the internal temperature of the storage, and the supply of the refrigerant to the evaporator arranged in the storage is controlled. The refrigerator is cooled to a desired temperature state. Then, when a predetermined time has elapsed after the start of the normal operation, the supply of the refrigerant to the evaporator is stopped and the evaporator is defrosted. Further, during the pull-down after the defrosting treatment, that is, during the cooling operation between the defrosting treatment and the transition to the next normal operation, the opening degree of the electronic expansion valve is set to a predetermined constant size to the evaporator. A refrigerant is supplied to rapidly cool the inside of the storage (see, for example, Patent Document 1).

Japanese Unexamined Patent Publication No. 2006-105554

However, in the cooling device as described above, since the opening degree of the electronic expansion valve at the time of pulling down is determined to be a constant size, there are the following problems. That is, in winter when the temperature of the outside air where the compressor or condenser is installed is relatively low, if the opening of the electronic expansion valve is constant in an excessive state, the refrigerant that has passed through the evaporator is a gas-liquid two-phase. There is a risk of damaging the compressor by causing a so-called liquid back phenomenon in which the compressor is sucked into the compressor in this state. Further, in the summer when the outside air temperature is relatively high, if the opening degree of the electronic expansion valve is constant in an excessively small state, the compressor may become abnormal in pressure and may not be driven.

In view of the above circumstances, the present invention provides a cooling device capable of avoiding pressure abnormality or breakage of the compressor by varying the opening degree of the electronic expansion valve during the cooling operation according to the cooling load. With the goal.

In order to achieve the above object, in the case of normal operation, the cooling device according to the present invention adjusts the opening degree of the electronic expansion valve so that the internal temperature of the storage chamber approaches a preset target temperature, and the storage is described. The storage is cooled to a desired temperature state by adjusting the flow rate of the refrigerant to the evaporator arranged in the storage, while the electronic expansion valve is closed in the case of the defrosting operation after the normal operation. The cooling device is provided with a valve opening degree control unit for stopping the supply of the refrigerant to the evaporator, and the valve opening degree control unit is used from after the defrosting operation to the next normal operation. In the case of cooling operation between, the valve opening setting is related to the temperature of the outside air in which the compressor that sucks and compresses the refrigerant from the evaporator is installed, and the opening of the electronic expansion valve and the temperature of the outside air. It is characterized in that the opening degree of the electronic expansion valve is set from the information and adjusted to the opening degree.

Further, in the case of normal operation, the cooling device according to the present invention adjusts the opening degree of the electronic expansion valve based on the internal temperature of the refrigerator, and adjusts the flow rate of the refrigerant to the evaporator arranged in the refrigerator. A valve that cools the refrigerator to a desired temperature state by adjusting, while closing the electronic expansion valve to stop the supply of the refrigerant to the evaporator in the case of the defrosting operation after the normal operation. A cooling device provided with an opening degree control unit, wherein the valve opening degree control unit is the current date in the case of a cooling operation between the defrosting operation and the transition to the next normal operation. It is characterized in that the opening degree of the electronic expansion valve is set and adjusted to the opening degree from the valve opening degree setting information associated with each month.

Further, according to the present invention, in the cooling device, the valve opening degree control unit sets the internal temperature in advance when the internal temperature of the storage becomes equal to or lower than a predetermined transition temperature in the case of the cooling operation. It is characterized in that the opening degree of the electronic expansion valve is adjusted so as to approach the target temperature.

According to the present invention, in the case of the cooling operation in which the valve opening control unit performs the cooling operation from the defrosting operation to the next normal operation, the compressor sucks and compresses the refrigerant from the evaporator. Since the opening degree of the electronic expansion valve is set from the temperature of the installed outside air and the valve opening setting information associated with the opening degree of the electronic expansion valve and the temperature of the outside air, the opening degree is adjusted to the opening degree, so that the cooling operation is performed. By varying the opening degree of the electronic expansion valve at that time according to the cooling load, it is possible to avoid pressure abnormality and breakage of the compressor.

Further, according to the present invention, in the case of the cooling operation from the defrosting operation to the transition to the next normal operation, the valve opening degree control unit has the current date and the opening degree of the electronic expansion valve. Sets the opening degree of the electronic expansion valve from the valve opening setting information associated with each month and adjusts to the opening degree. Therefore, the opening degree of the electronic expansion valve during the cooling operation is changed according to the cooling load. This has the effect of avoiding abnormal pressure or damage to the compressor.

FIG. 1 is a conceptual diagram conceptually showing the configuration of the cooling device according to the first embodiment of the present invention. FIG. 2 is a flowchart showing the processing contents of the valve opening degree adjusting process performed by the valve opening degree control unit shown in FIG. FIG. 3 is a conceptual diagram conceptually showing the configuration of the cooling device according to the second embodiment of the present invention. FIG. 4 is a flowchart showing the processing contents of the valve opening degree adjusting process performed by the valve opening degree control unit shown in FIG.

Hereinafter, preferred embodiments of the cooling device according to the present invention will be described in detail with reference to the accompanying drawings.

<Embodiment 1>
FIG. 1 is a conceptual diagram conceptually showing the configuration of the cooling device according to the first embodiment of the present invention. The cooling device illustrated here is applied to an open showcase 11 in which the products stored in the storage 10 are displayed and sold in a cooled state, and the electronic expansion valve 12 and the evaporator 13 are attached to the open showcase 11. On the other hand, the condenser 14 and the compressor 15 are provided outside the store where the open showcase 11 is installed.

The electronic expansion valve 12 adiabatically expands the low-temperature and high-pressure refrigerant discharged from the condenser 14 and supplies it to the evaporator 13. In the first embodiment, an electronic expansion valve 12 capable of changing the opening degree according to the opening degree command and adjusting the flow rate of the passing refrigerant when the opening degree command is given is applied. The compressor 15 compresses the low-temperature low-pressure refrigerant discharged from the evaporator 13 and gives it to the condenser 14 as a high-temperature and high-pressure refrigerant.

In this cooling device, the refrigerating cycle is performed by connecting the electronic expansion valve 12 and the evaporator 13 provided in the open showcase 11 to the condenser 14 and the compressor 15 in series with the refrigerant supply pipe line 16. 17 is configured. That is, in this cooling device, the high-temperature and high-pressure refrigerant discharged from the compressor 15 is cooled in the condenser 14 to become a low-temperature and high-pressure refrigerant. The low-temperature and high-pressure refrigerant is adiabatically expanded by the electronic expansion valve 12 to become a low-temperature and low-pressure refrigerant, which is supplied to the evaporator 13. The low-temperature and low-pressure refrigerant supplied to the evaporator 13 exchanges heat with the internal air of the storage 10 supplied by a blower fan (not shown), absorbs heat, and cools the storage 10. The refrigerant discharged from the evaporator 13 is sucked into the compressor 15 and again becomes a high-temperature and high-pressure refrigerant and is supplied to the condenser 14.

Further, the cooling device includes an internal temperature sensor 21, an outside air temperature sensor 22, and a valve opening degree control unit 23 as its characteristic control system. The internal temperature sensor 21 is provided inside the storage chamber 10. The internal temperature sensor 21 detects the internal temperature of the storage 10 and gives the detection result to the valve opening degree control unit 23 as an internal temperature signal.

The outside air temperature sensor 22 is provided in the vicinity of the outdoor unit 18 in which the condenser 14 and the compressor 15 are built. The outside air temperature sensor 22 detects the outside air temperature, and gives the detection result to the valve opening degree control unit 23 as an outside air temperature signal.

The valve opening degree control unit 23 controls the opening degree of the electronic expansion valve 12 according to a program or data stored in the electrically connected storage unit 24, and is an input processing unit 23a and a valve opening degree setting unit. It includes 23b, an opening command output unit 23c, and an output processing unit 23d.

Here, the storage unit 24 stores the target temperature information 24a, the valve opening degree setting information 24b, and the transition temperature information 24c as the characteristics of the first embodiment. The target temperature information 24a is information regarding the target temperature of the internal temperature of the storage 10 when the normal operation is performed. The valve opening degree setting information 24b is information in which the outside air temperature and the opening degree of the electronic expansion valve 12 are associated with each other. The valve opening degree setting information 24b is associated so that the opening degree of the electronic expansion valve 12 increases as the outside air temperature rises. For example, when the outside air temperature is less than 15 ° C, the valve opening is 200 pulses, when the outside air temperature is 15 ° C or more and less than 25 ° C, the valve opening is 300 pulses, and when the outside air temperature is 25 ° C or more and less than 30 ° C. The valve opening is 400 pulses, and the valve opening is 500 pulses when the outside air temperature is 30 ° C. or higher. The transition temperature information 24c is information on the transition temperature that serves as a reference for shifting from the cooling operation to the normal operation.

The input processing unit 23a inputs the internal temperature signal and the outside air temperature signal from the internal temperature sensor 21 and the outside air temperature sensor 22. Further, the input processing unit 23a inputs a command given from the main control unit 20 that collectively controls the operation of the cooling device.

The valve opening degree setting unit 23b sets the opening degree of the electronic expansion valve 12 in the cooling operation from the outside air temperature input through the input processing unit 23a and the valve opening degree setting information 24b read from the storage unit 24. .. Further, the valve opening degree setting unit 23b adjusts the opening degree of the electronic expansion valve 12 so that the internal temperature input through the input processing unit 23a approaches the target temperature included in the target temperature information 24a read from the storage unit 24 in the normal operation. It is to be set. Further, the valve opening degree setting unit 23b sets the opening degree of the electronic expansion valve 12 to a size that closes in the defrosting operation.

The opening command output unit 23c outputs an opening command to the electronic expansion valve 12. The output processing unit 23d outputs to the main control unit 20 that the cooling operation has been completed as a response signal.

The valve opening control unit 23 may be realized by software, for example, by causing a processing device such as a CPU (Central Processing Unit) to execute a program, or by hardware such as an IC (Integrated Circuit). It may be realized, or it may be realized by using software and hardware together.

The operation of the cooling device will be described. Here, the cooling device performs a cooling operation until the internal temperature of the storage 10 becomes equal to or lower than a predetermined temperature (transition temperature), performs a normal operation after the cooling operation, and adheres to the evaporator 13 after the normal operation reaches a predetermined time. Perform a defrosting operation to remove frost. After performing this defrosting operation, the cooling operation is performed again, and then the cycle of performing the normal operation is repeated. In the following, for convenience of explanation, the normal operation, the defrosting operation, and the cooling operation will be described in this order. As a premise, it is assumed that the compressor 15 and the blower fan are driven.

In the case of normal operation, the valve opening degree control unit 23, which has input the normal operation command given by the main control unit 20 by the input processing unit 23a, adjusts the opening degree of the electronic expansion valve 12 as follows. That is, when the valve opening degree control unit 23 inputs the internal temperature detected by the internal temperature sensor 21 as an internal temperature signal through the input processing unit 23a, the valve opening degree control unit 23 reads out the target temperature information 24a from the storage unit 24 through the valve opening degree setting unit 23b. .. Then, the valve opening degree control unit 23 sets the opening degree of the electronic expansion valve 12 so that the internal temperature approaches the target temperature included in the target temperature information 24a through the valve opening degree setting unit 23b, and the opening degree command output unit 23c. An opening command is output to the electronic expansion valve 12 through.

That is, in the case of normal operation, the valve opening degree control unit 23 adjusts the opening degree of the electronic expansion valve 12 so that the internal temperature of the storage chamber 10 approaches a preset target temperature, and arranges the valve opening degree control unit 23 in the storage chamber 10. The storage 10 is cooled to a desired temperature state by adjusting the flow rate of the refrigerant with respect to the evaporated evaporator 13.

After such a normal operation is performed for a predetermined time, the valve opening control unit 23 in which the defrosting operation command given by the main control unit 20 is input by the input processing unit 23a is electronically transmitted through the valve opening setting unit 23b. The opening degree of the expansion valve 12 is set to a size to be closed, and the opening degree command is output to the electronic expansion valve 12 through the opening degree command output unit 23c to close the electronic expansion valve 12.

That is, in the case of the defrosting operation, the valve opening degree control unit 23 closes the electronic expansion valve 12 and stops the supply of the refrigerant to the evaporator 13. As a result, the frost adhering to the evaporator 13 is removed by driving the blower fan.

After the defrosting operation is performed for a predetermined time, the valve opening degree control unit 23, which has input the cooling operation command given by the main control unit 20 to the input processing unit 23a, executes the valve opening degree adjusting process.

FIG. 2 is a flowchart showing the processing contents of the valve opening degree adjusting process performed by the valve opening degree control unit 23 shown in FIG.

The valve opening degree control unit 23 of the valve opening degree adjusting process waits for the input of the outside air temperature signal (outside air temperature) from the outside air temperature sensor 22 through the input processing unit 23a (step S101). When the outside air temperature is input through the input processing unit 23a (step S101: Yes), the valve opening degree control unit 23 reads the valve opening degree setting information 24b from the storage unit 24 through the valve opening degree setting unit 23b (step S102). The valve opening degree is set from the outside air temperature and the valve opening degree setting information 24b (step S103). The valve opening degree control unit 23 for which the valve opening degree is set in this way outputs an opening degree command to the electronic expansion valve 12 through the opening degree command output unit 23c (step S104).

As a result, the opening degree of the electronic expansion valve 12 is adjusted based on the outside air temperature, and the flow rate of the refrigerant with respect to the evaporator 13 is adjusted to cool the storage chamber 10.

The valve opening control unit 23, which outputs the opening command to the electronic expansion valve 12 in this way, waits for the input of the internal temperature signal (internal temperature) from the internal temperature sensor 21 through the input processing unit 23a (step S105). .. When the internal temperature is input through the input processing unit 23a (step S105: Yes), the valve opening control unit 23 reads the transition temperature information 24c from the storage unit 24 through the valve opening setting unit 23b (step S106), and the internal temperature. Determines whether or not is below the transition temperature (step S107).

When the internal temperature is not equal to or lower than the transition temperature (step S107: No), the valve opening degree control unit 23 repeats the processes of steps S105 to S107. On the other hand, when the internal temperature is equal to or lower than the transition temperature (step S107: Yes), the valve opening control unit 23 outputs a response of the completion of the cooling operation to the main control unit 20 through the output processing unit 23d (step S108). After that, the procedure is returned and the current process is completed.

By outputting the response of the completion of the cooling operation to the main control unit 20 in this way, when a normal operation command is given from the main control unit 20, the normal operation as described above is performed, and the valve opening degree control unit 23 Adjusts the opening degree of the electronic expansion valve 12 so that the internal temperature of the storage 10 approaches the target temperature.

As described above, according to the cooling device according to the first embodiment of the present invention, the case of the cooling operation in which the valve opening degree control unit 23 is in the cooling operation from the defrosting operation to the transition to the next normal operation. In addition, since the opening degree of the electronic expansion valve 12 is set from the outside air temperature and the valve opening degree setting information 24b and adjusted to the opening degree, the opening degree of the electronic expansion valve 12 during the cooling operation fluctuates according to the cooling load. By doing so, it is possible to avoid abnormal pressure or damage to the compressor 15.

Moreover, the valve opening degree control unit 23 adjusts the opening degree of the electronic expansion valve 12 so that when the internal temperature of the storage 10 becomes equal to or lower than the transition temperature in the cooling operation, the internal temperature approaches the target temperature. , It is possible to shorten the time required for the internal temperature to reach the target temperature.

<Embodiment 2>
FIG. 3 is a conceptual diagram conceptually showing the configuration of the cooling device according to the second embodiment of the present invention. The same components as those of the cooling device according to the first embodiment are designated by the same reference numerals, and the description thereof will be omitted as appropriate.

The cooling device illustrated here includes an internal temperature sensor 21 and a valve opening degree control unit 33 as its characteristic control system.

The valve opening degree control unit 33 controls the opening degree of the electronic expansion valve 12 according to a program or data stored in the electrically connected storage unit 34, and is an input processing unit 33a and a valve opening degree setting unit. It includes 33b, an opening command output unit 33c, and an output processing unit 33d.

Here, the storage unit 34 stores the target temperature information 34a, the valve opening degree setting information 34b, and the transition temperature information 34c as the characteristics of the second embodiment. The target temperature information 34a is information regarding the target temperature of the internal temperature of the storage 10 when the normal operation is performed. The valve opening degree setting information 34b is information in which the opening degree of the electronic expansion valve 12 is associated with each month. The valve opening degree setting information 34b is associated so that the opening degree of the electronic expansion valve 12 increases as the outside air temperature rises. For example, in January, the valve opening is 200 pulses, in February, the valve opening is 200 pulses, in March, the valve opening is 300 pulses, and in April, the valve opening is 200 pulses. 300 pulses, valve opening 400 pulses in May, valve opening 400 pulses in June, valve opening 500 pulses in July, valve in August The opening is 500 pulses, the valve opening is 500 pulses in September, the valve opening is 400 pulses in October, the valve opening is 300 pulses in November, and the valve opening is December. Is associated with a valve opening of 200 pulses. The transition temperature information 34c is information regarding a transition temperature that serves as a reference for shifting from the cooling operation to the normal operation.

The input processing unit 33a inputs the internal temperature signal from the internal temperature sensor 21. Further, the input processing unit 33a inputs a command given from the main control unit 30 that collectively controls the operation of the cooling device.

The valve opening setting unit 33b sets the opening degree of the electronic expansion valve 12 in the cooling operation from the information on the current date read from the built-in clock unit and the valve opening setting information 34b read from the storage unit 34. It is something to do. Further, the valve opening degree setting unit 33b adjusts the opening degree of the electronic expansion valve 12 so that the internal temperature input through the input processing unit 33a approaches the target temperature included in the target temperature information 34a read from the storage unit 34 in the normal operation. It is to be set. Further, the valve opening degree setting unit 33b sets the opening degree of the electronic expansion valve 12 to a size that closes in the defrosting operation.

The opening command output unit 33c outputs an opening command to the electronic expansion valve 12. The output processing unit 33d outputs to the main control unit 30 that the cooling operation is completed as a response signal.

The valve opening control unit 33 may be realized by software, for example, by causing a processing device such as a CPU (Central Processing Unit) to execute a program, or by hardware such as an IC (Integrated Circuit). It may be realized, or it may be realized by using software and hardware together.

The operation of the cooling device will be described. Here, the cooling device performs a cooling operation until the internal temperature of the storage 10 becomes equal to or lower than a predetermined temperature (transition temperature), performs a normal operation after the cooling operation, and adheres to the evaporator 13 after the normal operation reaches a predetermined time. Perform a defrosting operation to remove frost. After performing this defrosting operation, the cooling operation is performed again, and then the cycle of performing the normal operation is repeated. In the following, for convenience of explanation, the normal operation, the defrosting operation, and the cooling operation will be described in this order. As a premise, it is assumed that the compressor 15 and the blower fan are driven.

In the case of normal operation, the valve opening degree control unit 33, which has input the normal operation command given by the main control unit 30 by the input processing unit 33a, adjusts the opening degree of the electronic expansion valve 12 as follows. That is, when the valve opening degree control unit 33 inputs the internal temperature detected by the internal temperature sensor 21 as an internal temperature signal through the input processing unit 33a, the valve opening degree control unit 33 reads out the target temperature information 34a from the storage unit 34 through the valve opening degree setting unit 33b. .. Then, the valve opening degree control unit 33 sets the opening degree of the electronic expansion valve 12 so that the internal temperature approaches the target temperature included in the target temperature information 34a through the valve opening degree setting unit 33b, and the opening degree command output unit 33c. An opening command is output to the electronic expansion valve 12 through.

That is, in the case of normal operation, the valve opening degree control unit 33 adjusts the opening degree of the electronic expansion valve 12 so that the internal temperature of the storage chamber 10 approaches a preset target temperature, and arranges the valve opening degree control unit 33 in the storage chamber 10. The storage 10 is cooled to a desired temperature state by adjusting the flow rate of the refrigerant with respect to the evaporated evaporator 13.

After such a normal operation is performed for a predetermined time, the valve opening control unit 33 in which the defrosting operation command given by the main control unit 30 is input by the input processing unit 33a is electronically transmitted through the valve opening setting unit 33b. The opening degree of the expansion valve 12 is set to a size to be closed, and the opening degree command is output to the electronic expansion valve 12 through the opening degree command output unit 33c to close the electronic expansion valve 12.

That is, in the case of the defrosting operation, the valve opening degree control unit 33 closes the electronic expansion valve 12 and stops the supply of the refrigerant to the evaporator 13. As a result, the frost adhering to the evaporator 13 is removed by driving the blower fan.

After the defrosting operation is performed for a predetermined time, the valve opening degree control unit 33, which has input the cooling operation command given by the main control unit 30 to the input processing unit 33a, performs the valve opening degree adjusting process.

FIG. 4 is a flowchart showing the processing contents of the valve opening degree adjusting process performed by the valve opening degree control unit 33 shown in FIG.

The valve opening control unit 33 of the valve opening adjustment process reads information about the current date from the clock unit through the valve opening setting unit 33b (step S201), and the valve opening setting information 34b from the storage unit 34. (Step S202), and the valve opening degree is set from the current date and valve opening degree setting information 34b (step S203). The valve opening degree control unit 33 in which the valve opening degree is set in this way outputs an opening degree command to the electronic expansion valve 12 through the opening degree command output unit 33c (step S204).

As a result, the opening degree of the electronic expansion valve 12 is adjusted according to the month, and the flow rate of the refrigerant with respect to the evaporator 13 is adjusted to cool the storage chamber 10.

The valve opening control unit 33 that outputs the opening command to the electronic expansion valve 12 in this way waits for the input of the internal temperature signal (internal temperature) from the internal temperature sensor 21 through the input processing unit 33a (step S205). .. When the internal temperature is input through the input processing unit 33a (step S205: Yes), the valve opening control unit 33 reads the transition temperature information 34c from the storage unit 34 through the valve opening setting unit 33b (step S206), and the internal temperature. Determines whether or not is below the transition temperature (step S207).

When the internal temperature is not equal to or lower than the transition temperature (step S207: No), the valve opening degree control unit 33 repeats the processes of steps S205 to S207. On the other hand, when the internal temperature is equal to or lower than the transition temperature (step S207: Yes), the valve opening control unit 33 outputs a response of the completion of the cooling operation to the main control unit 30 through the output processing unit 33d (step S208). After that, the procedure is returned and the current process is completed.

By outputting the response of the completion of the cooling operation to the main control unit 30 in this way, when a normal operation command is given from the main control unit 30, the operation shifts to the normal operation as described above, and the valve opening degree control unit 33 Adjusts the opening degree of the electronic expansion valve 12 so that the internal temperature of the storage 10 approaches the target temperature.

As described above, according to the cooling device according to the second embodiment of the present invention, in the case of the cooling operation in which the valve opening degree control unit 33 is in the cooling operation from the defrosting operation to the transition to the next normal operation. In addition, since the opening degree of the electronic expansion valve 12 is set from the current date and the valve opening degree setting information 34b and adjusted to the opening degree, the opening degree of the electronic expansion valve 12 during the cooling operation is adjusted according to the cooling load. By varying the pressure, it is possible to avoid abnormal pressure or damage to the compressor 15.

Moreover, the valve opening degree control unit 33 adjusts the opening degree of the electronic expansion valve 12 so that when the internal temperature of the storage 10 becomes equal to or lower than the transition temperature in the cooling operation, the internal temperature approaches the target temperature. , It is possible to shorten the time required for the internal temperature to reach the target temperature.

Although preferred embodiments 1 and 2 of the present invention have been described above, the present invention is not limited thereto, and various modifications can be made.

In the refrigerating cycle 17 according to the first and second embodiments described above, the refrigerant 14 and the compressor 15 are connected to the electronic expansion valve 12 and the evaporator 13 provided in the open showcase 11 in series with the refrigerant. It was configured by connecting with a supply pipe 16, but in the present invention, electronic expansion valves and evaporators provided in a plurality of open showcases are arranged in parallel with the condenser and compressor. A refrigeration cycle may be configured by connecting with a refrigerant supply pipeline.

10 ... storage, 11 ... open showcase, 12 ... electronic expansion valve, 13 ... evaporator, 14 ... condenser, 15 ... compressor, 16 ... refrigerant supply pipeline, 17 ... refrigeration cycle, 18 ... outdoor unit, 20 ... Main control unit, 21 ... Internal temperature sensor, 22 ... Outside air temperature sensor, 23 ... Valve opening control unit, 23a ... Input processing unit, 23b ... Valve opening setting unit, 23c ... Opening command output unit, 23d ... Output Processing unit, 24 ... Storage unit, 24a ... Target temperature information, 24b ... Valve opening setting information, 24c ... Transition temperature information.

Claims (3)

In the case of normal operation, the opening degree of the electronic expansion valve is adjusted so that the internal temperature of the storage is close to the preset target temperature, and the flow rate of the refrigerant to the evaporator arranged in the storage is adjusted. In the case of the defrosting operation after the normal operation, the electronic expansion valve is closed to stop the supply of the refrigerant to the evaporator while cooling the storage to a desired temperature state. It is a cooling device equipped with a part,
The valve opening control unit is provided with a compressor that sucks and compresses the refrigerant from the evaporator in the case of the cooling operation from the defrosting operation to the transition to the next normal operation. Cooling characterized in that the opening degree of the electronic expansion valve is set and adjusted to the opening degree from the outside air temperature and the valve opening degree setting information associated with the opening degree of the electronic expansion valve and the outside air temperature. Device. In the case of normal operation, the storage is desired by adjusting the opening degree of the electronic expansion valve based on the internal temperature of the storage and adjusting the flow rate of the refrigerant with respect to the evaporator arranged in the storage. In the case of the defrosting operation after the normal operation, the cooling device is provided with a valve opening control unit that closes the electronic expansion valve to stop the supply of the refrigerant to the evaporator while cooling to a temperature state. There,
In the case of the cooling operation from the defrosting operation to the transition to the next normal operation, the valve opening control unit associates the current date with the opening of the electronic expansion valve on a monthly basis. A cooling device characterized in that the opening degree of the electronic expansion valve is set from the obtained valve opening degree setting information and adjusted to the opening degree. In the case of the cooling operation, when the internal temperature of the storage becomes equal to or lower than a predetermined transition temperature, the valve opening degree control unit uses the electronic expansion valve so that the internal temperature approaches a preset target temperature. The cooling device according to claim 1 or 2, wherein the opening degree of the cooling device is adjusted.

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