JPH05312433A - Freezer - Google Patents

Abstract

PURPOSE:To provide a freezer improved in its drying capability and capable of doing satisfactory drying operation without increasing the amount of charging of a refrigerant. CONSTITUTION:In a freezer in which there are provided a compressor 1, a condenser 2, a fluid reception unit 3, an expansion valve 4, and a evaporator 5 through a re-heater 6 parallely to the evaporator 5, and in which a refrigerant is directed to flow through both re-heater 6 and evaporator 5 upon drying operation to dry the interior of the freezer, a three-way valve 7 is provided on a discharge piping of the compressor 1, and upon the drying operation the three- way valve 7 is changed over to direct a refrigerator discharged from the compressor 1 to the re-heater 6, condenser 2, fluid reception unit 3, and evaporator 5 in order.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a refrigerating apparatus used to dry fish, noodles, agricultural products and the like stored in a drying cabinet at a suitable temperature with cold air.

[0002]

2. Description of the Related Art Conventionally, a refrigerating apparatus of this type has been disclosed in Japanese Patent Laid-Open No.
Various refrigeration circuits have been devised as shown in Japanese Patent No. 43270.

For example, as shown in FIG. 6, a compressor 50, a condenser 51, a liquid receiver 52, an expansion valve 53, and an evaporator 54 are connected by pipes, and a reheater 55 is installed in parallel with the evaporator 54.
And a branch pipe 56 branched from the outlet of the condenser 51 and connected to the reheater 55. Further, electromagnetic valves 57, 58 and 59 are provided on the branch pipe 56, the inlet side of the liquid receiver 52 and the inlet side of the expansion valve 53. In FIG. 6, the inside of the broken line indicates the inside of the outdoor unit, the inside of the chain double-dashed line indicates the inside of the drying cabinet, 60 and 61 are check valves, 62 is a temperature sensor, 63 is a humidity sensor, and 64 is the temperature and humidity inside the cabinet. 2 shows a control device for controlling.

In the cooling operation, the refrigerant is flowed in the order of the compressor 50, the condenser 51, the liquid receiver 52, the expansion valve 53, and the evaporator 54 to cool the inside of the drying chamber.

During the drying operation, the refrigerant discharged from the condenser 51 is introduced into the reheater 55 through the branch pipe 56, and then the liquid receiver 52 and the evaporator 54 are flowed in this order to the reheater 55. And the evaporator 54 are made to flow while the refrigerant is flowing to dry the inside of the refrigerator.

[0006]

However, according to the above construction, during the drying operation, the refrigerant discharged from the condenser 51 flows into the reheater 55, so that the temperature of the refrigerant flowing into the reheater 55 is increased. There was a problem that the drying capacity of the reheater 55 was low, which was low.

Further, since there is no refrigerant recovery system during the dry operation, the refrigerant in the outlet side pipe of the condenser 51 remains as it is during the cooling operation, and a large amount of refrigerant charge is required, resulting in a large capacity. The refrigeration system has a problem of being uneconomical.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a refrigerating apparatus which can improve the drying capacity and can perform a good drying operation without increasing the refrigerant charge amount.

[0009]

According to the present invention, a compressor, a condenser, a liquid receiver, a decompression device, and an evaporator are connected by piping, and
In the refrigerating apparatus in which a reheater is provided in parallel with the evaporator and the inside of the refrigerator is dried by flowing the refrigerant to both the reheater and the evaporator during the drying operation, in the discharge pipe of the compressor. A three-way valve is provided, and during the drying operation, the three-way valve is switched to allow the refrigerant discharged from the compressor to flow in the order of the reheater, the condenser, the liquid receiver, and the evaporator.

Further, a compressor, a condenser, a liquid receiver, a decompression device, and an evaporator are connected by piping, and a reheater is provided in parallel with the evaporator, and during the drying operation, the reheater and the evaporator. In a refrigerating device in which a refrigerant is allowed to flow in both sides to dry the inside of the refrigerator, a three-way valve is provided in the discharge pipe of the compressor, and a refrigerant recovery that connects the outlet pipe of the three-way valve and the suction pipe of the compressor A pipe is provided to switch the three-way valve during the dry operation to allow the refrigerant discharged from the compressor to flow in the order of reheater, condenser, liquid receiver, and evaporator, and for a certain period only when switching from the dry operation to the cooling operation. The refrigerant remaining in the reheater is recovered via the refrigerant recovery pipe.

[0011]

With the above-described structure, the refrigerating apparatus of the present invention allows the high-temperature refrigerant discharged from the compressor to directly flow into the reheater during the drying operation, thereby improving the drying capacity. In addition, since the high-temperature and high-pressure refrigerant that has exited the reheater is introduced into the condenser during this drying operation, it is possible to suppress an abnormal increase in high-pressure pressure and prevent the refrigeration system from stopping due to high-pressure cut. .. Furthermore, since the high temperature refrigerant that has exited the compressor is directly flown into the reheater, the drying capacity will not decrease even when the outside air temperature is low.

Further, a refrigerant recovery pipe for connecting the outlet pipe of the three-way valve and the suction pipe of the compressor is provided so that the refrigerant is recovered only when the drying operation is switched to the cooling operation. The refrigerant remaining in the heat device can be efficiently introduced into the refrigeration operation cycle, and the refrigerant remaining in the reheater can be prevented. As a result, there is no need to increase the refrigerant charge amount, and a large capacity refrigeration system can be used.

[0013]

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

FIG. 1 shows a refrigerant circuit of the refrigerating apparatus of the present invention. In this device, a compressor 1, a condenser 2, a liquid receiver 3, an expansion valve 4, and an evaporator 5 are connected by piping, and a reheater 6 is provided in parallel with the evaporator 5, and further, the compression is performed. A three-way valve 7 is provided on the discharge side of the machine 1, and a reheat circuit 8 is provided from the three-way valve 7 to the inlet side of the condenser 2 via the reheater 6. In the reheat circuit 8, a check valve 16 is provided in front of the connection point on the inlet side of the condenser 2. Also, 12
Is a refrigerant recovery circuit branched from the reheat circuit 8 on the outlet side of the three-way valve 7 and connected to the suction pipe of the compressor 1 via the solenoid valve 13 and the pressure regulating valve 10. Reference numeral 14 is a solenoid valve provided on the inlet side of the expansion valve 4, and 15 is a check valve provided between the three-way valve 7 and the branch point of the refrigerant recovery circuit 12 in the reheat circuit 8. 20 and 21 are blowers. 26 is a three-way valve 7
It is the pilot piping of.

Further, in FIG. 1, the inside of the broken line shows the inside of the outdoor unit, the inside of the chain double-dashed line shows the inside of the drying cabinet, 17 is a temperature sensor, 18 is a humidity sensor, and 19 is a controller for controlling the temperature and humidity in the cabinet. Indicates. The inside of the drying cabinet is dried and cooled to an appropriate temperature and humidity according to the stored items by the control device 19.

Reference numeral 22 denotes a hot gas bypass circuit which is branched from a pipe between the compressor 1 and the three-way valve 7 and is connected to a pipe on the inlet side of the evaporator 5 via a solenoid valve 23 and a pressure adjusting valve 24. .. The hot gas bypass circuit 22 defrosts the evaporator 5 by supplying high temperature hot gas discharged from the compressor 1 to the evaporator 5 while adjusting the pressure when the solenoid valve 23 is opened. .. Reference numeral 25 is a temperature sensor attached to the outlet side pipe of the evaporator 5. The temperature sensor 25 is electrically connected to a control device 19 described later and sends a detected signal. The set temperature is preset in the control device 19, and the temperature sensor 25
When the temperature detected by the hot water bypass circuit 22 becomes lower than the preset temperature, the solenoid valve 23 is opened to open the hot gas bypass circuit 22.
This is a configuration for flowing hot gas.

In the refrigerating apparatus thus constructed,
During the cooling operation, the refrigerant circulates as shown by the thick line in FIG.
That is, the control device 19 turns off the three-way valve 7 and turns off the solenoid valve 14.
Is controlled to be open, and the solenoid valve 13 is controlled to be closed, so that the refrigerant discharged from the compressor 1 receives the condenser 2, the liquid receiver 3, the expansion valve 4,
A cycle of sequentially flowing through the evaporator 5 and returning to the compressor 1 is configured. As a result, the inside of the drying chamber is cooled to the temperature set by the controller 19.

When a large amount of frost adheres to the evaporator 5 during the cooling operation and the temperature of the outlet side pipe of the evaporator 5 decreases, the signal of the temperature sensor 25 that detects this is input to the control device 19 and the solenoid valve 23. Opens and hot gas bypass circuit 2
2, hot gas flows, and defrosting operation by hot gas is started. Specifically, the refrigerant circulates as indicated by the thick line in FIG. 5, and the defrosting operation is performed while continuing the cooling operation. Here, the control of the solenoid valve 23 is performed by the temperature T detected by the temperature sensor 25.
Is opened when the temperature is lower than a preset temperature Ts preset in the control device 19, and is closed and restored when the difference T-Ts exceeds the preset temperature difference A.

Next, during the drying operation, the refrigerant circulates as indicated by the thick line in FIG. That is, the control device 19 controls the three-way valve 7 to be ON, the solenoid valve 14 to be opened, and the solenoid valve 13 to be closed, so that the refrigerant discharged from the compressor 1 is reheated through the three-way valve 7 to the reheat circuit 8. And a check valve 16, a condenser 2, a liquid receiver 3, an expansion valve 4, and an evaporator 5 in that order to return to the compressor 1. Then, the refrigerant is circulated through both the reheater 6 and the evaporator 5, both the reheater 6 and the evaporator are ventilated by the blower 20, and the temperature inside the drying chamber is set by the controller 19. And dried to humidity.

Next, when switching from the drying operation to the cooling operation, the refrigerant circulates as shown by the thick line in FIG. That is, the control device 19 controls the three-way valve 7 to be OFF, the solenoid valve 14 to be open, and the solenoid valve 13 to be open, and the refrigerant discharged from the compressor 1 is the condenser 2, the liquid receiver 3, and the expansion valve. 4. A cooling cycle in which the evaporator 5 sequentially flows and returns to the compressor 1 is configured. At this time, since the electromagnetic valve 13 is opened, the refrigerant recovery circuit 12 returns the refrigerant remaining in the reheater 6 during the drying operation to the suction side of the compressor 1 little by little while adjusting the pressure,
It is designed to eliminate the shortage of refrigerant during dry operation. Here, the solenoid valve 13 is kept open for a certain period of time so that all the residual refrigerant can be recovered. Then, the solenoid valve 13 is closed after a predetermined time, and only the normal cooling operation is performed.

When a large amount of frost adheres to the evaporator 5 during this drying operation and the temperature of the outlet side pipe of the evaporator 5 decreases, the signal of the temperature sensor 25 which detects this is input to the control device 19 and the solenoid valve 23. Opens and hot gas bypass circuit 2
2, hot gas flows, and defrosting operation by hot gas is started. Also in this case, the same control as the defrosting during the cooling operation is performed, and the defrosting operation is performed while continuing the drying operation.

The above three-way valve 7 and solenoid valves 14, 13, 2
Switching of 3 is automatically performed by the control device 19 which inputs signals from the temperature sensors 17 and 25 and the humidity sensor 18.

In the refrigerating apparatus thus controlled,
During the dry operation, the three-way valve 7 is switched to allow the high-temperature refrigerant discharged from the compressor 1 to directly flow into the reheater 6, and then flow through the condenser 2 and then the liquid receiver 3 and the evaporator 5 in this order. Since the configuration is adopted, the high-temperature refrigerant discharged from the compressor 1 can directly flow into the reheater 6 during the drying operation, and the drying capacity can be improved. In particular, since the condenser 2 is passed through after exiting the reheater 6, it is possible to suppress an abnormal increase in the high pressure during the drying operation, and prevent the compressor 1 from being stopped due to the high pressure cut. Furthermore, since the high temperature refrigerant that has exited the compressor is directly flown into the reheater, the drying capacity will not decrease even when the outside air temperature is low.

Further, the refrigerant recovery circuit 12 for connecting the outlet pipe of the three-way valve 7 and the suction pipe of the compressor 1 is provided so that the refrigerant is recovered only when the drying operation is switched to the cooling operation. The refrigerant remaining in the reheater 6 during operation can be efficiently introduced into the refrigeration operation cycle, and the refrigerant remaining in the reheater 6 can be prevented. As a result, there is no need to increase the refrigerant charge amount, and a large capacity refrigeration system can be used.

Further, the refrigerant recovery as described above is performed by the reheater 6
Since it is performed from the inlet side, the liquid refrigerant does not return to the compressor 1 to cause liquid compression. Moreover,
Since such a refrigerant recovery operation can be performed while continuing the cooling or drying operation, energy saving can be promoted.

Further, since the check valve 15 is provided between the three-way valve 7 in the reheat circuit 8 and the branch point of the refrigerant recovery circuit 12, the backflow of the refrigerant from the reheater 6 is prevented when the refrigeration system is stopped. Can be prevented. That is, when the refrigeration system is stopped,
Due to the pressure difference, the refrigerant in the reheater 6 leaks from the three-way valve 7 through the pilot pipe 26 of the three-way valve 7 to the suction side of the compressor 1. As a result, leakage continues until the internal pressure of the compressor 1 becomes the same as the internal pressure of the reheater 6, and a large amount of refrigerant is trapped in the compressor 1 and causes forming and liquid compression. Therefore, by providing the check valve 15, it is possible to prevent the refrigerant from leaking to the suction side of the compressor 1 through the reheat circuit 8, the three-way valve 7, and the pilot pipe 26 when the refrigeration system is stopped, and to prevent the forming or the liquid flow. Compression can be prevented. As a result, the number of ON-OFs of the compressor 1 when the pump down operation is stopped can be reduced, and the refrigeration system can be stopped for a long period of time.

[0027]

As described above, according to the present invention, the high-temperature refrigerant discharged from the compressor can directly flow into the reheater during the drying operation, and the drying capacity can be improved. In addition, since the high-temperature and high-pressure refrigerant that has exited the reheater is introduced into the condenser during this drying operation, it is possible to suppress an abnormal increase in high-pressure pressure and prevent the refrigeration system from stopping due to high-pressure cut. .. Furthermore, since the high temperature refrigerant that has exited the compressor is directly flown into the reheater, the drying capacity will not decrease even when the outside air temperature is low.

Further, a refrigerant recovery pipe for connecting the outlet pipe of the three-way valve and the suction pipe of the compressor is provided so that the refrigerant is recovered only when the drying operation is switched to the cooling operation. The refrigerant remaining in the heat device can be efficiently introduced into the refrigeration operation cycle, and the refrigerant remaining in the reheater can be prevented. As a result, there is no need to increase the refrigerant charge amount, and a large capacity refrigeration system can be used.

[Brief description of drawings]

FIG. 1 is a refrigerant circuit diagram showing a refrigerating apparatus of the present invention.

FIG. 2 is a refrigerant circuit diagram showing refrigerant circulation during a cooling operation.

FIG. 3 is a refrigerant circuit diagram showing refrigerant circulation during a drying operation.

FIG. 4 is a refrigerant circuit diagram showing refrigerant circulation at the time of switching from a drying operation to a cooling operation.

FIG. 5 is a refrigerant circuit diagram showing a defrosting operation during a cooling operation.

FIG. 6 is a refrigerant circuit diagram showing a conventional refrigeration system.

[Explanation of symbols]

 1 Compressor 2 Condenser 3 Liquid receiver 4 Expansion valve 5 Evaporator 6 Reheater 7 Three-way valve 8 Reheat circuit 12 Refrigerant recovery circuit

Claims (2)

[Claims] 1. A compressor, a condenser, a liquid receiver, a decompression device, and an evaporator are connected by piping, and a reheater is provided in parallel with the evaporator, and the reheater and the evaporator are provided during a drying operation. In a refrigerating apparatus in which a refrigerant is supplied to both sides to dry the inside of the refrigerator, a three-way valve is provided in the discharge pipe of the compressor, and the three-way valve is switched during the drying operation to reheat the refrigerant discharged from the compressor. A refrigerating apparatus having a configuration in which a condenser, a liquid receiver, and an evaporator flow in this order. 2. A compressor, a condenser, a liquid receiver, a decompression device, and an evaporator are connected by piping, and a reheater is provided in parallel with the evaporator, and the reheater and the evaporator are provided during a drying operation. In a refrigerating apparatus in which a refrigerant is supplied to both sides to dry the inside of the refrigerator, a three-way valve is provided in the discharge pipe of the compressor, and a refrigerant recovery that connects the outlet pipe of the three-way valve and the suction pipe of the compressor A pipe is provided to switch the three-way valve during the dry operation to allow the refrigerant discharged from the compressor to flow in the order of reheater, condenser, liquid receiver, and evaporator, and for a certain period only when switching from the dry operation to the cooling operation. A refrigerating apparatus configured to recover the refrigerant remaining in the reheater via the refrigerant recovery pipe.