JP2021134940A - Refrigerating device - Google Patents

Abstract

To provide a refrigerating device that can adjust the amount of a refrigerant while being made compact and lightweight.SOLUTION: A refrigerating device 1 comprises: a refrigerator 10 comprising a compressor 30, and a heat exchanger for exchanging heat of a refrigerant discharged from the compressor 30; and a cooling device comprising an evaporator 40, and an inlet expansion valve 42 at an inlet of the evaporator 40. A refrigerant adjustment valve for adjusting the flow rate of the refrigerant is provided at an outlet of the evaporator 40.SELECTED DRAWING: Figure 1

Description

The present invention relates to a refrigeration system.

Conventionally, refrigerating devices for cooling refrigerating and freezing showcases have been known in stores such as supermarkets and convenience stores. Such a refrigerating device includes a compressor, a condenser, an expansion valve, and an evaporator, and forms a refrigerating cycle by connecting these with a refrigerant pipe.
It is known that such a refrigerating apparatus is provided with a refrigerant amount adjusting tank that adjusts the amount of refrigerant flowing through the refrigeration cycle by storing the excess refrigerant when surplus refrigerant is generated due to fluctuations in the refrigerating load. (See, for example, Patent Document 1).

JP-A-2017-122524

However, in the conventional refrigerating apparatus, the size and weight may be increased by providing the refrigerant amount adjusting tank.
An object of the present invention is to provide a freezing device capable of adjusting the amount of refrigerant while reducing the size and weight.

The present invention comprises a refrigerator including a compressor and a heat exchanger for exchanging heat of the refrigerant discharged from the compressor, and a cooling device including an evaporator and an inlet expansion valve at the inlet of the evaporator. The refrigerating apparatus is characterized in that a refrigerant adjusting valve for adjusting the flow rate of the refrigerant is provided at the outlet of the evaporator.

According to this, by adjusting the flow rate of the refrigerant with the refrigerant adjusting valve, the surplus refrigerant is stored inside the evaporator.
Therefore, it is possible to adjust the amount of refrigerant without providing a refrigerant amount adjusting unit such as a refrigerant amount adjusting tank that adjusts the flow rate of the refrigerant by storing the refrigerant, and it is possible to reduce the size and weight of the refrigerator. can.

According to the present invention, the amount of refrigerant can be adjusted while reducing the size and weight.

The figure which shows the schematic structure of the refrigerant circuit of the refrigerating apparatus which concerns on embodiment of this invention. The figure which shows the schematic structure of the refrigerating apparatus Flow chart showing the operation of the refrigeration system The figure which shows the schematic structure of the refrigerant circuit of the refrigerating apparatus in the modification of this invention.

The first invention is a refrigerator provided with a compressor and a heat exchanger for exchanging heat of the refrigerant discharged from the compressor, and a cooling device provided with an evaporator and an inlet expansion valve at the inlet of the evaporator. The refrigerator is characterized in that a refrigerant adjusting valve for adjusting the flow rate of the refrigerant is provided at the outlet of the evaporator.

According to this, by adjusting the flow rate of the refrigerant with the refrigerant adjusting valve, the surplus refrigerant is stored inside the evaporator.
Therefore, the refrigerating apparatus can adjust the amount of refrigerant without providing a refrigerant amount adjusting unit such as a refrigerant amount adjusting tank that adjusts the flow rate of the refrigerant by storing the refrigerant. That is, in the refrigerating device 1, the refrigerant adjusting tank can be omitted, and the refrigerating device 1 can be made smaller and lighter.

The second invention is characterized in that an internal heat exchanger is provided for heat exchange between the refrigerant discharged from the compressor and the refrigerant injected from the refrigerant adjusting valve.

According to this, the degree of heating is surely taken from the refrigerant injected from the refrigerant adjusting valve by this internal heat exchanger, and the refrigerant is sent to the compressor. Therefore, the liquid return of the refrigerant in the compressor and the liquid compression are prevented.

A third invention includes a control unit for adjusting the opening degree of the inlet expansion valve and the refrigerant adjusting valve, and the control unit reduces the opening degree of the refrigerant adjusting valve to provide a refrigerant in the evaporator. It is characterized by storing.

According to this, the refrigerating apparatus adjusts the opening degree between the inlet expansion valve and the refrigerant adjusting valve according to the refrigerant temperature of the evaporator.
Therefore, when the refrigerant temperature of the evaporator 40 drops below a predetermined value, the refrigerant temperature of the evaporator can be returned to a desired temperature by adjusting the opening degree between the inlet expansion valve and the refrigerant adjusting valve. can.

The fourth invention includes a temperature sensor that detects the refrigerant temperature at the inlet and outlet of the evaporator, and the control unit acquires the detection value of the temperature sensor, and based on the detection value, of the evaporator. It is characterized in that the degree of superheat of the refrigerant is acquired and the opening degree of the refrigerant adjusting valve is reduced when the degree of superheat is equal to or higher than a predetermined value.

According to this, the control device opens and closes the refrigerant adjusting valve according to the degree of superheat of the evaporator.
Therefore, it is suppressed that the refrigerant temperature of the evaporator is excessively lowered, and frost formation on the evaporator is suppressed.

In a fifth aspect of the invention, the control unit acquires the temperature inside the cooling device and the detected value of the temperature sensor, and based on the temperature inside the cooling device and the detected value, the compression is performed. It is characterized in that the drive of the machine is controlled and the opening degree of the refrigerant adjusting valve is reduced when the drive frequency of the compressor is at the minimum value.

According to this, the opening degree of the refrigerant adjusting valve is adjusted in a state where the driving of the compressor is sufficiently suppressed.
Therefore, in addition to adjusting the temperature inside the refrigerator by the compressor, the temperature inside the refrigerator can also be adjusted by the refrigerant adjusting valve.

In the sixth invention, the control unit acquires the refrigerant temperature of the compressor and the refrigerant temperature of the refrigerant adjusting valve, and the difference between the refrigerant temperature of the compressor and the refrigerant temperature of the refrigerant adjusting valve is It is characterized in that the drive of the compressor is stopped when the value is equal to or less than a predetermined value.

According to this, the refrigerant containing the moist steam is suppressed from being taken into the compressor.
Therefore, in the freezing device, so-called liquid return and liquid compression are suppressed.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a diagram showing a schematic configuration of a refrigerant circuit of the refrigerating apparatus 1 according to the embodiment of the present invention.
As shown in FIG. 1, the refrigerating apparatus 1 includes a refrigerator 10 that compresses and exchanges heat with a refrigerant, and a showcase 20 that is cooled by a refrigerant sent from the refrigerator 10, and these form a refrigerating cycle. doing. The showcase 20 is, for example, a cooling device installed in a facility such as a convenience store or a supermarket to cool refrigerated or frozen products displayed inside. In the refrigerating apparatus 1 of the present embodiment, the refrigerating machine 10 and the showcase 20 are integrally provided.
The refrigerating apparatus 1 of the present embodiment uses carbon dioxide as a refrigerant whose high pressure side refrigerant pressure (high pressure) is equal to or higher than the critical pressure (supercritical). In this embodiment, a carbon dioxide refrigerant is used as the refrigerant, but the present invention is not limited to this, and various refrigerants may be used.

The refrigerator 10 includes a compressor 30 that compresses and discharges the refrigerant to a required pressure. A refrigerant pipe 80 is connected to the discharge port of the compressor 30, and a gas cooler 32 is connected to the compressor 30 via the refrigerant pipe 80.
The gas cooler 32 functions as a heat exchanger that cools the refrigerant sent from the compressor 30 by exchanging heat with the outside air by operating a blower fan 34 provided in the refrigerator 10. When a condensable refrigerant is used as the refrigerant in the refrigerating apparatus 1, the gas cooler 32 functions as a condenser.

The refrigerator 10 includes an internal heat exchanger 36. The internal heat exchanger 36 contains a refrigerant pipe 80 extending from the outlet side of the gas cooler 32 and a refrigerant pipe 80 connected to the suction port of the compressor 30. The internal heat exchanger 36 raises the temperature of the refrigerant sucked into the compressor 30 by exchanging heat between these two refrigerant pipes 80, improving the operating efficiency of the refrigerating device 1, and returning or compressing the liquid. To prevent the occurrence of. Hereinafter, the temperature of the refrigerant sucked into the compressor 30 will be referred to as the suction temperature.
An outlet service valve 38 for sending the refrigerant to the showcase 20 is connected to the refrigerant pipe 80 on the outlet side of the gas cooler 32 at a location located on the downstream side of the location housed in the internal heat exchanger 36. ..
On the other hand, the refrigerant pipe 80 connected to the suction port of the compressor 30 has an inlet service for returning the refrigerant from the showcase 20 to a location located upstream of the location housed in the internal heat exchanger 36. The valve 39 is connected. The inlet service valve 39 is connected to the suction port of the compressor 30 via the refrigerant pipe 80.

The showcase 20 includes an evaporator 40, an inlet expansion valve 42, an outlet adjusting valve 44, and a blower fan 46. The inlet of the evaporator 40 is connected to the outlet service valve 38 by the refrigerant pipe 80. An inlet expansion valve 42 is provided in the refrigerant pipe 80 that connects the evaporator 40 and the outlet service valve 38. The inlet expansion valve 42 of the present embodiment is an electronic expansion valve, a so-called electric valve, that opens and closes the valve by driving a motor to control the flow rate of the refrigerant and the evaporation temperature of the refrigerant. The opening degree of the inlet expansion valve 42 can be adjusted steplessly, and by adjusting the opening degree of the inlet expansion valve 42, the evaporation temperature of the refrigerant in the inlet expansion valve 42, that is, the inlet of the evaporator 40 The temperature of the refrigerant in the above can be adjusted.

In the evaporator 40, the refrigerant sent from the refrigerant pipe 80 and the air inside the showcase 20 exchange heat, thereby cooling the inside of the showcase 20.
The air (cold air) cooled by the evaporator 40 is circulated by the blower fan 46.

The outlet of the evaporator 40 is connected to the inlet service valve 39 by the refrigerant pipe 80. An outlet adjusting valve 44 is provided in the refrigerant pipe 80 that connects the evaporator 40 and the inlet service valve 39.
The outlet adjusting valve 44 is an electric valve substantially the same as the inlet expansion valve 42, and the outlet adjusting valve 44 functions as a refrigerant adjusting valve for adjusting the flow rate of the refrigerant. The outlet adjusting valve 44 opens and closes the valve by driving the motor to control the flow rate of the refrigerant. The opening degree of the outlet adjusting valve 44 can be adjusted steplessly, and by adjusting the opening degree of the outlet adjusting valve 44, the degree of superheat of the refrigerant in the evaporator 40, that is, the inlet of the evaporator 40 The temperature difference between the refrigerant and the outlet can be adjusted.

The refrigerant pipe 80 located on the suction side of the compressor 30 is provided with a suction temperature sensor 50 that detects the temperature of the refrigerant sucked into the compressor 30.
An inlet temperature sensor 52 and an outlet temperature sensor 54 are provided in each of the refrigerant pipes 80 connected to the inlet and the outlet of the evaporator 40, respectively. More specifically, the inlet temperature sensor 52 is provided between the inlet expansion valve 42 and the inlet of the evaporator 40, and the outlet temperature sensor 54 is provided between the outlet of the evaporator 40 and the outlet regulating valve 44. ing.
The inlet temperature sensor 52 and the outlet temperature sensor 54 detect the temperature of the refrigerant at the inlet and the outlet of the evaporator 40, respectively.

A regulating valve outlet temperature sensor 56 is provided in the refrigerant pipe 80 connected to the outlet of the outlet regulating valve 44. More specifically, the regulating valve outlet temperature sensor 56 is provided between the outlet of the outlet regulating valve 44 and the inlet of the inlet service valve 39.
The regulating valve outlet temperature sensor 56 detects the temperature of the refrigerant at the outlet of the outlet regulating valve 44.
Further, the showcase 20 is provided with an internal temperature sensor 58 that detects the temperature inside the showcase 20. Hereinafter, the temperature inside the showcase 20 will be referred to as the temperature inside the refrigerator.

Further, a regulating valve inlet pressure sensor 60 and a regulating valve outlet pressure sensor 62 are provided at the inlet of the outlet regulating valve 44 and the refrigerant pipe 80 connected to the outlet, respectively. More specifically, the regulating valve inlet pressure sensor 60 is provided between the inlet of the evaporator 40 and the outlet regulating valve 44, like the outlet temperature sensor 54, and the regulating valve outlet pressure sensor 62 is the regulating valve outlet temperature. Similar to the sensor 56, it is provided between the outlet of the outlet adjusting valve 44 and the inlet of the inlet service valve 39.
The regulating valve inlet pressure sensor 60 and the regulating valve outlet pressure sensor 62 detect the pressure of the refrigerant at the inlet and outlet of the evaporator 40, respectively.

Next, the control configuration of this embodiment will be described.
FIG. 2 is a diagram showing a schematic configuration of the refrigerating apparatus 1 according to the present embodiment.
As shown in FIG. 2, in the present embodiment, the refrigerating device 1 includes a control device 70 that controls each unit in an integrated manner. The control device 70 includes a computer having a processor such as a CPU or MPU and a memory device such as a ROM or RAM, and functions as a control unit that controls each part of the refrigerating device 1.
The control device 70 includes a storage unit 72 that stores various data related to the operation of the refrigerating device 1 such as various setting conditions related to the operation control method of the refrigerating device 1 and the relationship between the pressure of the refrigerant and the saturation temperature. There is.

The control device 70 includes a suction temperature sensor 50, an inlet temperature sensor 52, an outlet temperature sensor 54, a regulating valve outlet temperature sensor 56, an internal temperature sensor 58, a regulating valve inlet pressure sensor 60, and a regulating valve outlet pressure sensor 62. It is configured so that the detected detection value can be acquired. Based on the detected values acquired from these sensors and the setting conditions stored in the storage unit 72, the control device 70 includes the drive frequency of the compressor 30, the rotation speeds of the blower fans 34 and 46, the inlet expansion valve 42, and the like. The opening degree with the outlet adjusting valve 44 is controlled respectively.

The control device 70 of the present embodiment acquires the detected values of the inlet temperature sensor 52 and the outlet temperature sensor 54, and obtains the degree of superheat of the refrigerant in the evaporator 40 from these detected values.
The control device 70 controls the drive frequency of the compressor 30 and the opening degree of the inlet expansion valve 42 so that the degree of superheat becomes a predetermined value stored in the storage unit 72.

Further, the control device 70 inputs the detected value of the internal temperature sensor 58 to acquire the actual temperature inside the showcase 20, and determines whether or not the cooling capacity of the refrigerating device 1 exceeds the refrigerating load. .. Then, when it is determined that the cooling capacity of the refrigerating device 1 exceeds the refrigerating load of the refrigerating device 1 in the state where the drive frequency of the compressor 30 is the minimum value, the control device 70 executes the refrigerant amount adjusting operation. ..

The refrigerant amount adjusting operation is an operation of storing the surplus refrigerant inside the evaporator 40 when the cooling capacity of the refrigerating device 1 exceeds the refrigerating load. Specifically, the opening degree of the outlet adjusting valve 44 is reduced to suppress the outflow of the refrigerant from the evaporator 40, and the opening degree of the inlet expansion valve 42 is increased to allow the inflow of the refrigerant flowing into the evaporator 40. Increase the amount. As a result, the excess refrigerant is stored inside the evaporator 40.

Further, in this refrigerant amount adjusting operation, the control device 70 controls the opening degree of the inlet expansion valve 42 so that the evaporation temperature of the refrigerant in the inlet expansion valve 42 becomes a predetermined value.
Further, the control device 70 controls the opening degree of the outlet adjusting valve 44 so that the degree of superheat of the refrigerant in the evaporator 40 becomes a predetermined value.
As a result, the control device 70 adjusts the refrigerant temperature so that the degree of superheat of the refrigerant in the evaporator 40 becomes a predetermined value stored in the storage unit 72.
In the present embodiment, the control device 70 makes the opening degree of the outlet adjusting valve 44 fully open except when the refrigerant amount adjusting operation is performed, that is, when the refrigerating device 1 performs a normal cooling operation.

Further, the control device 70 acquires the detected values of the suction temperature sensor 50 and the regulating valve outlet temperature sensor 56, and stops the operation of the compressor 30 when the difference between them becomes a predetermined value or less.
This prevents the occurrence of so-called liquid return in the compressor 30.

Next, the operation of this embodiment will be described.
FIG. 3 is a flowchart showing the operation of the refrigerating apparatus 1.
In the normal cooling operation of the refrigerating device 1, the control device 70 drives the compressor 30 constituting the refrigerating cycle, and the refrigerant is discharged from the compressor 30. The discharged refrigerant is cooled by the gas cooler 32 and then sent out to the showcase 20 via the refrigerant pipe 80. This refrigerant is depressurized by the inlet expansion valve 42 and supplied to the evaporator 40. The refrigerant vaporized in the evaporator 40 cools the inside of the showcase 20 and returns to the compressor 30.

In the normal cooling operation of the refrigerating device 1, the control device 70 acquires the detected values of the inlet temperature sensor 52 and the outlet temperature sensor 54, and obtains the degree of superheat of the refrigerant in the evaporator 40 from these detected values.
The control device 70 adjusts the obtained superheat degree by controlling the drive frequency of the compressor 30 and the opening degree of the inlet expansion valve 42 so that the superheat degree becomes a predetermined value stored in the storage unit 72. do. As a result, the control device 70 adjusts the temperature inside the showcase 20 to a set predetermined value.
As described above, in the normal cooling operation of the refrigerating apparatus 1, the outlet adjusting valve 44 is fully opened.

In the normal cooling operation of the refrigerating device 1, the control device 70 determines whether or not the temperature inside the refrigerator is equal to or lower than a predetermined value (step ST1). When it is determined that the temperature inside the refrigerator is equal to or lower than a predetermined value, that is, the cooling capacity of the refrigerating device 1 exceeds the refrigerating load of the refrigerating device (step ST1: YES), the control device 70 controls the drive frequency of the compressor 30. (Step ST2).
After reducing the drive frequency of the compressor 30, the control device 70 again determines whether or not the temperature inside the refrigerator is equal to or lower than a predetermined value (step ST3). When it is determined that the temperature inside the refrigerator is not below a predetermined value (step ST3: NO), the control device 70 stops the decrease in the drive frequency of the compressor 30 (step ST11), and cools the refrigerating device 1 normally. Return to operation.

When it is determined that the temperature inside the refrigerator is equal to or lower than a predetermined value (step ST3: YES), the control device 70 determines whether or not the drive frequency of the compressor 30 is the minimum value (step ST4).
When it is determined that the drive frequency of the compressor 30 is not the minimum value (step ST4: NO), the control device 70 reduces the drive frequency of the compressor 30 again (step ST2), and the internal temperature is again below the predetermined value. It is determined whether or not the frequency is (step ST3).

When it is determined that the drive frequency of the compressor 30 is the minimum drive frequency which is the minimum value (step ST4: YES), does the control device 70 elapse a predetermined time after the compressor 30 reaches the minimum drive frequency? It is determined whether or not (step ST5). When it is determined that the predetermined time has not elapsed (step ST5: NO), the control device 70 determines step ST5 again at a predetermined interval.
When it is determined that the predetermined time has elapsed (step ST5: YES), the control device 70 again determines whether or not the temperature inside the refrigerator is equal to or lower than the predetermined value (step ST6).

When it is determined that the temperature inside the refrigerator is not below a predetermined value (step ST6: NO), the control device 70 stops the decrease in the drive frequency of the compressor 30 (step ST11), and cools the refrigerating device 1 normally. Return to operation.
When it is determined that the temperature inside the refrigerator is equal to or lower than a predetermined value (step ST6: YES), the control device 70 performs a refrigerant amount adjusting operation.

Specifically, the opening degree of the outlet adjusting valve 44 is reduced to suppress the outflow of the refrigerant from the evaporator 40, and the opening degree of the inlet expansion valve 42 is increased to allow the inflow of the refrigerant flowing into the evaporator 40. Increase the amount (step ST7). As a result, the excess refrigerant is stored inside the evaporator 40.

As described above, in addition to storing the excess refrigerant inside the evaporator 40, the control device 70 opens the inlet expansion valve 42 so that the evaporation temperature of the refrigerant in the inlet expansion valve 42 becomes a predetermined value. Control the degree. Further, the control device 70 controls the opening degree of the outlet adjusting valve 44 so that the degree of superheat of the refrigerant in the evaporator 40 becomes a predetermined value.
As a result, the control device 70 adjusts the refrigerant temperature so that the degree of superheat of the refrigerant in the evaporator 40 becomes a predetermined value stored in the storage unit 72.

In this way, while adjusting the opening degrees of the outlet adjusting valve 44 and the inlet expansion valve 42, the control device 70 acquires the detection values of the suction temperature sensor 50 and the adjusting valve outlet temperature sensor 56. That is, the control device 70 acquires the suction temperature and the refrigerant temperature at the outlet of the outlet adjusting valve 44. Then, the control device 70 determines whether or not the difference between these temperatures is equal to or less than a predetermined value (step ST8). When it is determined that the difference between the suction temperature and the refrigerant temperature at the outlet of the outlet adjusting valve 44 is equal to or less than a predetermined value (step ST8: YES), the control device 70 stops the operation of the compressor 30 (step ST9). ). This prevents the occurrence of liquid return in the compressor 30.

When it is determined that the difference between the suction temperature and the refrigerant temperature at the outlet of the outlet regulating valve 44 is not equal to or less than a predetermined value (step ST8: NO), the control device 70 detects the regulating valve inlet pressure sensor 60 again. The saturation temperature is acquired from the value, and the temperature of the refrigerant in the evaporator 40 is acquired from the detected values of the inlet temperature sensor 52 and the outlet temperature sensor 54. Then, the control device 70 determines whether or not the degree of superheat of the refrigerant in the evaporator 40 has reached a predetermined value (step ST10).

When it is determined that the degree of superheat is not a predetermined value (step ST10: NO), the control device 70 adjusts the opening degrees of the outlet adjusting valve 44 and the inlet expansion valve 42 again, and the degree of superheating becomes a predetermined value. (Step ST7).
When it is determined that the degree of superheat is a predetermined value (step ST10: YES), the control device 70 returns the refrigerating device 1 to the normal cooling operation.

By performing the refrigerant amount adjusting operation in this way, the refrigerating apparatus 1 can store the surplus refrigerant inside the evaporator 40. Therefore, the refrigerating device 1 can adjust the amount of refrigerant without providing a refrigerant amount adjusting tank (receiver tank). That is, in the refrigerator 1, the refrigerant adjusting tank can be omitted, and the refrigerator 10 can be made smaller and lighter.

Further, the refrigerant injected from the outlet adjusting valve 44 is heat-exchanged with the refrigerant discharged from the compressor 30 by the internal heat exchanger 36. The internal heat exchanger 36 ensures that the degree of heating is taken from the refrigerant injected from the outlet regulating valve 44, and the refrigerant is sent to the compressor 30. Therefore, the liquid return and the liquid compression of the refrigerant in the compressor 30 are prevented.

Further, in this refrigerant amount adjusting operation, the opening degrees of the inlet expansion valve 42 and the outlet adjusting valve 44 are controlled so that the degree of superheat of the refrigerant in the evaporator 40 becomes a predetermined value stored in the storage unit 72. The refrigerant temperature is adjusted to.
This prevents the temperature of the refrigerant in the evaporator 40 from dropping excessively. Therefore, frost formation on the evaporator 40 is suppressed, and so-called defrosting operation (defrosting operation) is suppressed. That is, by performing the defrosting operation, it is possible to suppress an increase in the temperature inside the showcase 20.

As described above, according to the present embodiment, the refrigerating apparatus 1 includes a refrigerator 10 including a compressor 30 and a gas cooler 32, and an inlet expansion valve 42 at the inlet of the evaporator 40 and the evaporator 40. In the refrigerating apparatus including the case 20, an outlet adjusting valve 44 is provided at the outlet of the evaporator 40.
As a result, the excess refrigerant can be stored inside the evaporator 40 by opening and closing the outlet adjusting valve 44 to adjust the flow rate of the refrigerant.
Therefore, the refrigerating device 1 can adjust the amount of refrigerant without providing a refrigerant amount adjusting unit such as a refrigerant amount adjusting tank (receiver tank). That is, in the refrigerator 1, the refrigerant adjusting tank can be omitted, and the refrigerator 10 can be made smaller and lighter.

Further, according to the present embodiment, the refrigerant injected from the outlet adjusting valve 44 is heat-exchanged with the refrigerant discharged from the compressor 30 by the internal heat exchanger 36. The internal heat exchanger 36 ensures that the degree of heating is taken from the refrigerant injected from the outlet regulating valve 44, and the refrigerant is sent to the compressor 30. Therefore, the liquid return and the liquid compression of the refrigerant in the compressor 30 are prevented.

Further, according to the present embodiment, the refrigerating apparatus 1 includes an inlet temperature sensor 52 and an outlet temperature sensor 54 for detecting the refrigerant temperature in the evaporator 40, and a regulating valve inlet pressure sensor 60 for detecting the refrigerant pressure. There is. Then, the control device 70 acquires the detected values of the inlet temperature sensor 52 and the outlet temperature sensor 54, and adjusts the opening degree between the inlet expansion valve 42 and the outlet adjusting valve 44 based on the detected values. bottom.
As a result, the refrigerating device 1 adjusts the opening degree between the inlet expansion valve 42 and the outlet adjusting valve 44 according to the refrigerant temperature of the evaporator 40.
Therefore, when the refrigerant temperature of the evaporator 40 drops below a predetermined value, the refrigerant temperature of the evaporator 40 is returned to a desired temperature by adjusting the opening degree between the inlet expansion valve 42 and the outlet adjusting valve 44. Can be made to.

Further, according to the present embodiment, the control device 70 acquires the detected values of the front inlet temperature sensor 52 and the outlet temperature sensor 54, and acquires the degree of superheat of the refrigerant of the evaporator 40 based on the detected values. do. The control device 70 is configured to adjust the opening degree of the outlet adjusting valve 44 when the degree of heating is equal to or higher than a predetermined value.
As a result, the control device 70 opens and closes the outlet adjusting valve 44 according to the degree of superheat of the evaporator 40.
Therefore, it is suppressed that the refrigerant temperature of the evaporator 40 is excessively lowered, and frost formation on the evaporator 40 is suppressed.

Further, according to the present embodiment, the control device 70 acquires the detection values of the temperature inside the showcase 20, the inlet temperature sensor 52, the outlet temperature sensor 54, and the adjusting valve inlet pressure sensor 60, and the inside of the refrigerator. The drive of the compressor 30 is controlled based on the temperature and the detected value. Then, the control device 70 is configured to adjust the opening degree of the outlet adjusting valve 44 when the driving frequency of the compressor 30 is the minimum value.
As a result, the opening degree of the outlet adjusting valve 44 is adjusted while the drive of the compressor 30 is sufficiently suppressed.
Therefore, in addition to adjusting the temperature inside the refrigerator by the compressor 30, the temperature inside the refrigerator can also be adjusted by the outlet adjusting valve 44.

Further, according to the present embodiment, the control device 70 acquires the refrigerant temperature of the compressor 30 and the refrigerant temperature of the outlet adjusting valve 44, and obtains the refrigerant temperature of the compressor 30 and the refrigerant temperature of the outlet adjusting valve 44. When the difference between the two is equal to or less than a predetermined value, the drive of the compressor 30 is stopped.
As a result, it is possible to prevent the refrigerant containing the moist steam from being taken into the compressor 30.
Therefore, the freezing device 1 is prevented from causing so-called liquid return and liquid compression.

The above-described embodiment illustrates one aspect of the present invention, and can be arbitrarily modified and applied without departing from the spirit of the present invention.

In the above-described embodiment, the refrigerator 1 has a configuration in which one showcase 20 is connected to one refrigerator 10, but the present invention is not limited to this, and for example, as shown in FIG. 4, two or more shows A case may be provided. In FIG. 4, each sensor is omitted.

Further, for example, in the above-described embodiment, the internal heat exchanger 36 is provided, but the present invention is not limited to this, and an accumulator may be used.

Further, for example, the refrigerating apparatus 1 of the present embodiment has a configuration in which the refrigerating machine 10 and the showcase 20 are integrally provided, but the present invention is not limited to this, and the refrigerating machine 10 and the showcase 20 are separately provided. It may be installed.

As described above, the refrigerating apparatus according to the present invention can be suitably used for a refrigerating apparatus for the purpose of reducing the overall size and weight.

1 Refrigerator 10 Refrigerator 20 Showcase (cooling equipment)
30 Compressor 32 Gas cooler (heat exchanger)
36 Internal heat exchanger 40 Evaporator 42 Inlet expansion valve 44 Outlet regulating valve (refrigerant regulating valve)
46 Blower fan 50 Intake temperature sensor (temperature sensor)
52 Inlet temperature sensor (temperature sensor)
54 Outlet temperature sensor (temperature sensor)
56 Control valve outlet temperature sensor (temperature sensor)
58 Internal temperature sensor (temperature sensor)
60 Control valve inlet pressure sensor (pressure sensor)
62 Control valve outlet pressure sensor (pressure sensor)
70 Control device (control unit)
80 Refrigerant piping

Claims (6)

In a refrigerating apparatus including a compressor and a heat exchanger for exchanging heat of the refrigerant discharged from the compressor, and a cooling device including an evaporator and an inlet expansion valve at the inlet of the evaporator.
A refrigerating apparatus characterized in that a refrigerant adjusting valve for adjusting the flow rate of the refrigerant is provided at the outlet of the evaporator. The refrigerating apparatus according to claim 1, further comprising an internal heat exchanger for heat exchange between the refrigerant discharged from the compressor and the refrigerant injected from the refrigerant adjusting valve. A control unit for adjusting the opening degree of the inlet expansion valve and the refrigerant adjusting valve is provided.
The refrigerating apparatus according to claim 1, wherein the control unit stores the refrigerant in the evaporator by reducing the opening degree of the refrigerant adjusting valve. A temperature sensor for detecting the refrigerant temperature at the inlet and outlet of the evaporator is provided.
The control unit acquires the detected value of the temperature sensor, and based on the detected value, acquires the degree of superheat of the refrigerant of the evaporator.
The refrigerating apparatus according to claim 3, wherein the opening degree of the refrigerant adjusting valve is reduced when the degree of superheat is equal to or higher than a predetermined value. The control unit acquires the temperature inside the cooling device and the detected value of the temperature sensor, and controls the drive of the compressor based on the temperature inside the cooling device and the detected value. ,
The refrigerating apparatus according to claim 4, wherein the opening degree of the refrigerant adjusting valve is reduced when the driving frequency of the compressor is at the minimum value. The control unit acquires the refrigerant temperature of the compressor and the refrigerant temperature of the refrigerant adjusting valve, and when the difference between the refrigerant temperature of the compressor and the refrigerant temperature of the refrigerant adjusting valve is equal to or less than a predetermined value. The refrigerating apparatus according to any one of claims 3 to 5, wherein the drive of the compressor is stopped.

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