JPH10300321A - Cooler for freezer refrigerator and its defrosting method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a cooler for a large-sized freezer refrigerator featuring a low equipment cost and capable of effecting a sufficient defrosting operation simultaneously with continuation of cooling operation. SOLUTION: Each circulation circuit for circulating refrigerant through a refrigerant compressor 10, an air cooled condenser 11, a liquid receiver 3, a cooler 12 and a liquid separator 19 in this order is provided with a defrosting high pressure refrigerant circuit 16 connecting the refrigerant compressor 10 and the cooler 12 with each other and a valve kit 2 for switching cooling operation of the cooler 12 and defrosting operation by hot gas bypass method.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cooling device used in a large-sized refrigerated warehouse and the like, and a method for defrosting the same.

[0002]

2. Description of the Related Art FIGS. 5 to 7 show a conventional refrigerator for refrigerators and refrigerators. FIG. 5 is a layout diagram of a cooler, FIG. 6 is a refrigerant circuit diagram of the cooler, and FIG. is there.
In the figure, 31 is a plurality of partitioned freezing compartments of a large freezing warehouse, 32 is a cooling device arranged in each freezing compartment 31, and communicates with a compressor 33, a condenser 34, an expansion valve 35 and a cooler 36. Refrigerant pipe 37 for circulating refrigerant, solenoid valve 3 for liquid
8, a thermobank 39, a suction pressure adjusting device 40, and a hot gas solenoid valve 41. 34a is an outside air fan of the condenser 34, 36a is a heat transfer fin mounted at a small interval on the outer periphery of a heat transfer tube 37 provided in a meandering shape by a cooler 36, and 36b is a cooler.

In the conventional refrigerator for refrigerators and refrigerators configured as described above, the refrigerant compressed by the compressor 3 becomes high-temperature and high-pressure refrigerant gas.
It liquefies by exchanging heat with the outside air blown in 4a. The high-pressure refrigerant liquid is supplied to the cooler 36 after the supply amount is controlled by the expansion valve 35 and reduced to a low pressure. In the cooler 36, the decompressed refrigerant liquid exchanges heat with the air in the freezing chamber 31 blown by the fan 36b to be gasified, and the air to be cooled is blown into the freezing chamber 31 as the cool air and stored therein. Cool things. The gasified low-pressure refrigerant gas is sucked into the compressor 33 and the cycle is repeated again. At this time, the refrigerant gas discharged from the compressor 33 communicates with the thermobank 39, flows into the condenser 34, and stores exhaust heat in the thermobank.

When the temperature in the freezing chamber 31 detected by a temperature sensor (not shown) reaches a predetermined temperature, the compressor 3 is controlled by a command from an automatic control device of a cooling device (not shown).
The operation of Step 3 is stopped, and the liquid solenoid valve 38 is closed. Further, if the cooling operation is continued for a long time,
Since the frost is formed so as to close the gap a, the amount of heat exchange of the cooler 36 decreases, and the liquid electromagnetic valve 38 is periodically closed, the hot gas electromagnetic valve 41 is opened, and the high-temperature and high-pressure refrigerant from the compressor 33 is released. The gas is supplied to the cooler 36 to melt the frost. The high-temperature and high-pressure refrigerant gas is cooled and liquefied by the cooler 36, but is completely gasified by the heat stored in the thermobank 39 and is sucked into the compressor 33.

[0005]

The conventional refrigerator for refrigerators and refrigerators is constructed as described above, and the arrangement of the compressor 33 and the cooler 36 in each freezer compartment 31 is 1: 1. Are required, and the equipment cost is increasing. Further, there is a problem that the heat capacity of the thermobank 39 for storing exhaust heat for defrosting the cooler 36 is limited.

The present invention has been made to solve the above problems, and does not require a large number of cooling devices.
It is an object of the present invention to provide a refrigerator for a refrigerator having a low equipment cost and a high defrosting efficiency, and a defrosting method thereof.

[0007]

According to a first aspect of the present invention, there is provided a refrigerating / refrigerating cooling apparatus comprising: a circulation circuit in which a refrigerant circulates in the order of a refrigerant compressor, an air-cooled condenser, a liquid receiver, a liquid separator, and a cooler. Each time, a high-pressure defrosting refrigerant circuit for connecting the refrigerant compressor and the cooler is provided, and a valve kit for switching between a cooling operation and a defrosting operation of the cooler is provided.

According to a second aspect of the present invention, the valve kit includes an expansion valve, an electromagnetic valve for opening and closing a circuit for introducing a high-temperature and high-pressure refrigerant gas to the cooler as the cooler is defrosted, and a low-pressure side for discharging the refrigerant from the cooler. It is equipped with an electromagnetic valve connected in parallel to the capillary of the refrigerant circuit and an automatic control device for controlling the operation of each device.

In a third aspect of the present invention, the valve kit includes an expansion valve, an electromagnetic valve for opening and closing a circuit for introducing high-temperature and high-pressure refrigerant gas to the cooler as the cooler is defrosted, and a low-pressure side for discharging the refrigerant from the cooler. A pressure regulator connected to the refrigerant circuit;
An automatic control device for controlling the operation of each of the devices.

[0010] In a fourth aspect of the present invention, the liquid separator has a function of exchanging heat between the low-pressure refrigerant condensate generated by defrosting and the high-temperature and high-pressure refrigerant condensate.

According to a fifth aspect of the present invention, an expansion valve for introducing high-pressure refrigerant liquid from a high-pressure side refrigerant circuit to a cooler is closed, and an electromagnetic valve for introducing high-temperature and high-pressure refrigerant gas from a high-pressure refrigerant circuit for defrosting to a cooler is opened. At the same time, the solenoid valve of the low-pressure side refrigerant circuit connected in parallel with the capillary tube discharged from the cooler is throttled so as to evaporate the condensed refrigerant liquid in the cooler.

According to a sixth aspect of the present invention, an expansion valve for introducing high-pressure refrigerant liquid from a high-pressure side refrigerant circuit to a cooler is closed, and an electromagnetic valve for introducing high-temperature and high-pressure refrigerant gas from a high-pressure refrigerant circuit for defrosting to a cooler is opened. In addition, the amount of refrigerant discharged from the cooler is adjusted by adjusting the pressure adjusting device of the low-pressure side refrigerant circuit so as to vaporize the condensed refrigerant liquid in the cooler.

A seventh aspect of the present invention is a high-pressure defrosting refrigerant for connecting a refrigerant compressor and a cooler for each circulation circuit in which the refrigerant circulates in the order of a refrigerant compressor, an air-cooled condenser, a liquid receiver, a cooler, and a liquid separator. A circuit is provided, and a cooling operation is performed by at least one other cooler while performing a defrosting operation by at least one cooler of a refrigerator for a refrigerator including a valve kit for switching a cooling operation and a defrosting operation of the cooler. The cooling operation to be performed and the defrosting operation are mixed.

According to an eighth aspect of the present invention, there is provided a condenser having a fan for blowing ambient air, and when performing defrosting of a cooler, the number of rotations or the number of operating fans is reduced to reduce the amount of air to be blown. Is to be reduced.

According to a ninth aspect of the present invention, there is provided a liquid separator for exchanging heat between a low-pressure refrigerant condensate generated by defrosting and a high-temperature and high-pressure refrigerant condensate, wherein the liquid separator has a large ratio of the surface area of the inner surface to the outer surface of the heat transfer tube. It has a heat tube.

According to a tenth aspect of the present invention, there is provided a liquid separator for exchanging heat between a low-pressure refrigerant condensate generated by defrosting and a high-temperature and high-pressure refrigerant condensate. Has a large refrigerant flow path.

According to an eleventh aspect of the present invention, there is provided a liquid separator for exchanging heat between a low-pressure refrigerant condensate generated by defrosting and a high-temperature and high-pressure refrigerant condensate, wherein the low-pressure refrigerant condensate and the high-pressure refrigerant condensate In the same direction or the opposite direction.

According to a twelfth aspect, the refrigerant is a refrigerant compressor,
A high-pressure refrigerant circuit for defrosting that connects the refrigerant compressor and the cooler is provided for each circulation circuit that circulates in the order of the air-cooled condenser, the liquid receiver, the cooler, and the liquid separator, and a valve that switches between cooler cooling operation and defrost operation. The kit includes an expansion valve, an electromagnetic valve that opens and closes a circuit that introduces high-temperature and high-pressure refrigerant gas to the cooler as the cooler is defrosted, and an electromagnetic valve connected in parallel to the capillary of the low-pressure refrigerant circuit that discharges refrigerant from the cooler. And an automatic control device for controlling the operation of each device, and a pressure regulating device is provided on a solenoid valve connected in parallel with the capillary of the low-pressure side refrigerant circuit.

According to a thirteenth aspect, the defrosting operation is performed by at least one cooler of the refrigerator for a refrigerator.
When the cooling operation for performing the cooling operation and the defrosting operation are mixed in at least one other cooler, the opening degree of the expansion valve of the cooler that is simultaneously cooling immediately after the start of the defrosting of the cooler is temporarily fixed. I have to.

According to a fourteenth aspect of the present invention, the defrosting operation is performed by at least one cooler of the refrigerator for a refrigerator and a refrigerator.
In at least one other cooler, when the cooling operation for performing the cooling operation and the defrosting operation are mixed, cooling is performed immediately after the start of the defrosting of the cooler, and the stopped cooler that is not performing the defrosting is forcibly cooled. I try to put in.

[0021]

BEST MODE FOR CARRYING OUT THE INVENTION

Embodiment 1 FIG. FIG. 1 is a refrigerant circuit diagram of a refrigerator for a refrigerator according to a first embodiment of the present invention. In the drawings, description of components having functions equivalent to those of the related art will be omitted. The refrigerator 1 includes an air-cooled condenser 11, a liquid receiver 3, and a liquid separator in a circulation circuit in which the refrigerant flows in the order of the refrigerant compressor 10, the air-cooled condenser 11, the liquid receiver 3, the cooler 12, and the liquid separator 19. The high-pressure refrigerant, which has passed through the high-pressure refrigerant-side heat transfer tube 19c passing through the inside 19, is reduced in pressure by the expansion valve 13a and introduced into the cooler 12 into the low-pressure refrigerant introduction circuit 14a. The high-pressure refrigerant circuit 16 for defrost is connected so as to flow into the refrigerant circuit 12. The defrosting high-pressure refrigerant circuit 16 is branched from a refrigerant circuit 13 that reaches the air-cooled condenser 11, and is provided with an electromagnetic valve 16a as a main valve. The cooler 12 is provided with a plurality of coolers 12 each having a desired capacity according to the scale of the refrigerator 1, and each is connected to the high-pressure side refrigerant circuit 14, the low-pressure side refrigerant circuit 15, and the defrosting high-pressure refrigerant circuit 16 independently. Therefore, at least one of them can be operated for cooling or defrosting.

Reference numeral 2 denotes a valve kit, which is installed at a ratio of one set to one cooler 12 and controls a cooling operation for introducing a refrigerant into the cooler 12 from a refrigerant supply branch point 14b of the high-pressure side refrigerant circuit 14. Valve 13a for controlling the defrosting operation for introducing the refrigerant from the high-pressure refrigerant circuit 16 for defrost to the cooler 12, and the cooler 12
An electromagnetic valve 15a for controlling the discharge of refrigerant from the low-pressure side refrigerant circuit 15 to the low-pressure side refrigerant circuit 15, and a capillary tube 15b connected in parallel with the electromagnetic valve 15a. It is installed. The defrosting high-pressure refrigerant circuit 16 is provided with an electromagnetic valve 16a immediately after branching off from the refrigerant circuit 13.

In the cooling operation of the refrigerator for a refrigerator having the above-described structure, the expansion valve 13a and the solenoid valve 15a are opened, and 16a and 16b are closed. At this time, the capillary tube 15b is always in an open state. However, since the flow passage resistance of the capillary tube 15b is large, the refrigerant hardly flows to the 15b side. The refrigerant compressed by the compressor 10 becomes a high-temperature and high-pressure refrigerant gas, and is sent to the air-cooled condenser 11 by the refrigerant circuit 13. In the air-cooled condenser 11, air is blown by the condenser fan 11a, and the high-temperature and high-pressure refrigerant and the outside air exchange heat with each other, and the refrigerant gas is condensed into a high-pressure refrigerant liquid. The high-pressure refrigerant liquid generated in the air-cooled condenser 11 is
After passing through the high-pressure refrigerant circuit 14 and passing through the high-pressure refrigerant heat transfer tube 19c in the liquid separator 19, heat exchange is performed with the refrigerant returning from the low-pressure refrigerant circuit 15, and then sent to the valve kit 2 via the refrigerant supply branch point 14b. . Further, the high-pressure refrigerant liquid enters a mixed state of the low-pressure refrigerant liquid and the refrigerant gas through the expansion valve 13a, and is introduced into the cooler 12 through the low-pressure refrigerant introduction circuit 14a.

In the cooler 12, the refrigerant in the mixed state of the refrigerant liquid and the refrigerant gas and the air in the refrigerator 1 exchange heat with each other by being blown by the cooler fan 12a, the refrigerant is vaporized, and the low-pressure refrigerant gas become. Then, the refrigerant gas is returned to the compressor 10 through the solenoid valve 15a and the liquid separator 19. At this time, the air in the refrigerator 1 passing through the cooler 12 is cooled, so that the object to be cooled placed in the refrigerator 1 can be cooled. The air temperature in the refrigerator 1 is constantly managed by a measuring instrument such as a temperature sensor, and is set to a predetermined set temperature.
When the air temperature becomes high, the cooling operation is performed by causing the expansion valve 13a to function and supply the refrigerant to the cooler 12. On the other hand, when the air temperature becomes low, the function of the expansion valve 13a is stopped. Then, the supply of the refrigerant to the cooler 12 is stopped to stop the cooling operation.

Next, the defrosting operation will be described. When the cooling operation is continued for a long time, frost-like ice is generated and adheres to the heat transfer tubes and the fins in the cooler 12. The state of the frost adhesion depends on the air temperature in the refrigerator 1 and the low-pressure refrigerant introduction circuit 1.
Estimation or determination is made based on the difference in the temperature of the refrigerant passing through 4a, the cooling operation time of the cooler 12, the time set by the user, the combination of these conditions, and the like. As a result of the determination, when it is determined that it is necessary to perform defrost,
Start the defrosting operation. The defrosting operation is performed by the cooler fan 12a.
Is stopped, the expansion valve 13a and the solenoid valve 15a are fully closed, the refrigerant does not flow from the high-pressure side refrigerant circuit 14 to the cooler 12, the solenoid valves 16a and 16b are opened, and the compressor 10 sets the high temperature and high pressure. The changed refrigerant gas is directly introduced into the cooler 12. The high-temperature and high-pressure refrigerant gas introduced into the cooler 12 is rapidly cooled and condensed by the heat capacity of the cooler 12 to which frost is attached, and becomes a mixed state of liquid and gas. Due to the condensation latent heat of the high-temperature and high-pressure refrigerant, the cooler 12
It is possible to melt the frost adhering to the surface. The refrigerant in the mixed state is returned from the low-pressure side refrigerant circuit 15 to the liquid separator 19 via the capillary tube 15b, the refrigerant gas is returned to the compressor 10, and the refrigerant liquid is a high-temperature refrigerant liquid flowing through the high-pressure refrigerant side heat transfer tube 19c. The refrigerant gas evaporated by heat exchange with the refrigerant gas is returned to the compressor 10.

The defrosting operation is performed by at least one cooler constituting the cooling device, and at the same time, the cooling operation is performed by at least one other cooler. However, there may be a case where the number of coolers that simultaneously perform the defrosting operation is limited in order to suppress a rise in the internal temperature of the refrigerator or stabilize the operation of the entire cooling device. In this case, if the number of coolers that need to be defrosted is larger than the limit number, the defrosting operation of the coolers of the number of units falling within the limit is first performed, and after the defrosting operation of those coolers is completed. Then, the remaining coolers are sequentially put into the defrosting operation. During this time, at least one other cooler continues the cooling operation.

Here, the relationship between the operation state of the refrigerator for the refrigerator and the pressure balance of the refrigerant will be described. 5 and 6, reference numeral 41 denotes a suction gas of the compressor, 42 denotes a discharge gas of the compressor, 43 denotes a high-pressure condensate, 44 denotes a high-pressure supercooled liquid, 45 denotes a condensate by a defrosting operation, and 46 denotes a capillary tube 15.
b, a low-pressure throttle refrigerant in which the high-pressure supercooled liquid 44 is throttled by the expansion valve 13a; 48, a low-pressure superheated gas that has passed through a cooler performing a cooling operation; Frost decompressed refrigerant 46 and low pressure superheated gas 48
Represents the low-pressure combined refrigerant after being combined in the low-pressure side refrigerant circuit 15. In the cooler performing the defrosting operation, the defrosting high-pressure refrigerant circuit 16 and the defrosting condensate 45 that has passed through the cooler 12 are reduced to the state of the defrosting low-pressure refrigerant 46 flowing through the low-pressure side refrigerant circuit 15 by the capillary tube 15b. Since the pressure is reduced, it is possible to continue the defrosting operation while continuing the cooling operation by balancing the pressure with the low-pressure superheated gas 48 flowing through the low-pressure side refrigerant circuit 15 of the cooler performing the cooling operation at the same time. .

According to the cooling device for a refrigerator-freezer of the first embodiment as described above, the defrosting operation is performed by at least one cooler, while the cooling operation is performed by at least one other cooler. Since the frost operation can be mixed, it is possible to suppress an increase in the internal temperature during defrosting. By exchanging heat between the refrigerant in the gas-liquid two-phase state condensed by the defrosting operation and the high-pressure side condensed refrigerant liquid, the energy use efficiency accompanying the defrosting operation can be improved, that is, energy can be saved. There is no need to bother starting and stopping the compressor at the start of the defrosting operation, and the stable operation of the entire cooling device can be performed. The refrigerant condensate generated by the defrosting operation is transferred to a capillary tube (15).
By performing heat exchange with the throttle and the high-pressure side condensate according to b), the reliability of the entire cooling device with respect to prevention of damage due to liquid compression of the compressor by sufficiently vaporizing and returning to the compressor is improved.

Embodiment 2 In the first embodiment, the flow rate of the condenser 11 is not adjusted during the defrosting operation. During the defrosting operation, the number of rotations of the condenser fan 11a is reduced, or a part of the plurality of condenser fans 11a is stopped to reduce the air flow of the air-cooled condenser 11. Accordingly, the amount of the high-temperature and high-pressure refrigerant gas condensed in the air-cooled condenser 11 decreases, and as a result, the amount of the high-temperature and high-pressure refrigerant gas sent to the cooler 12 via the defrosting high-pressure refrigerant circuit 16 relatively increases. Therefore, the amount of heat supplied for defrosting the cooler 12 increases accordingly. As a result, the same effect as in the first embodiment can be obtained, and the required time for the defrosting operation can be further reduced.

Embodiment 3 In the first and second embodiments, the low pressure side refrigerant circuit 15 includes the solenoid valve 15a and the capillary tube 15b.
Are shown for the refrigerant circuit connected in parallel. In the fourth embodiment, as shown in FIG.
Pressure adjusting device 1 such as a thermal expansion valve, a manual expansion valve, an electronic expansion valve, etc.
5c. In the refrigerator for a refrigerator-refrigerator configured as described above, while the cooling operation is being performed, the flow path of the low-pressure side refrigerant circuit 15 of the valve kit 2 is fully opened to perform the defrosting operation. The refrigerant is discharged to the suction side of the compressor while restricting the refrigerant liquid so that the flow path of the low-pressure side refrigerant circuit 15 is partially opened. As a result, by performing the cooling operation and the defrosting operation in the same manner as in the first embodiment, the same operation and effect as those in the first embodiment can be obtained. The method of balancing the refrigerant pressure based on FIG. 5 flowing through the low-pressure side refrigerant circuit 15 of each of the cooler performing the cooling operation and the cooler performing the defrosting operation is also described in the capillary 15b in the first embodiment. This is the same as the case where.

Embodiment 4 FIG. In the first embodiment, the refrigerant circuit using the liquid separator 19 in front of the suction side of the compressor 10 of the low-pressure side refrigerant circuit 15 is shown. However, as shown in FIG. The low pressure side auxiliary heat exchanger 19d is used to exchange heat between the low pressure refrigerant in the gas-liquid mixed state flowing through the low pressure refrigerant side flow path 19e and the high pressure liquid state refrigerant flowing through the high pressure refrigerant side flow path 19f. It is to let. In the refrigerator for a refrigerator according to the fifth embodiment configured as described above, by performing the cooling operation and the defrosting operation in the same manner as in the first embodiment, the same effect as in the first embodiment is obtained. To play.

Embodiment 5 In the fourth embodiment, the circuit using the low-pressure side auxiliary heat exchanger 19d has been described, but the low-pressure refrigerant side flow path 19e and the high-pressure refrigerant side flow path 19d are described.
For the flow path shape of f, a low pressure side auxiliary heat exchanger 19d is used in which the heat transfer area ratio and flow path volume ratio of the low pressure refrigerant side flow path 19e and the high pressure refrigerant side flow path 19f are changed to various states. Even when the refrigerant circuit is configured as described above, by performing the cooling operation and the defrosting operation in the same manner as in the first embodiment, the same operation and effect as in the fifth embodiment can be obtained. it can.

Embodiment 6 FIG. In the circuit using the low-pressure side auxiliary heat exchanger 19d described in the fourth embodiment, the directions of the refrigerant flowing through the low-pressure refrigerant side flow path 19e and the high-pressure refrigerant side flow path 19f are set to the same direction or the opposite directions. In the case where the refrigerant circuit is configured using the low-pressure side auxiliary heat exchanger 19d, the cooling operation and the defrosting operation are performed in the same manner as in the first embodiment.
The same operation and effect as in the case of can be obtained.

Embodiment 7 In the first embodiment, the solenoid valve 15a and the capillary tube 15b are connected in parallel to the low-pressure side refrigerant circuit 15, and the low-pressure refrigerant gas discharged from the cooler during the cooling operation, and the condensed refrigerant discharged from the cooler during the defrosting operation, Both are returned to the common low-pressure side refrigerant circuit 15. In the seventh embodiment, as shown in FIG. 4, a common low-pressure side refrigerant is supplied from a capillary tube 15b via a pressure adjusting device 4 such as a capillary tube, a wet expansion valve, a manual expansion valve, and an electronic expansion valve. It returns to the circuit 15. In the refrigerator for a refrigerator-freezer configured as described above, all the coolers 12 performing the cooling operation in the refrigerator-freezer 1 return directly to the low-pressure side refrigerant circuit 15 via the electromagnetic valve 15a in the open state. The cooler 12 performing the defrosting operation is a solenoid valve 15a.
Is closed, the condensed refrigerant is passed through the capillary tube 15b, and then returned to the low-pressure side refrigerant circuit 15, where it is further passed through the pressure regulator 4 on the low-pressure side refrigerant circuit 15. As a result, the pressure of the condensed refrigerant generated by the defrosting operation and the pressure of the low-pressure refrigerant gas generated by the cooling operation can be balanced and returned to the liquid separator 19, so that the same method as in the first embodiment is used. By performing the cooling operation and the defrosting operation in the embodiment, the same effects as in the case of the second embodiment can be obtained. In addition,
The same operation and effect can be obtained even when the low pressure side auxiliary heat exchanger 19d shown in FIG. 3 is used instead of the liquid separator 19.

The relationship between the pressure balance of the refrigerant flowing on the apparatus in this case will be described. As shown in FIGS. 5 and 6, in the present embodiment, the refrigerant flowing through the low-pressure side refrigerant circuit of the cooler performing the defrosting operation firstly receives the defrosted condensate 45.
Is once depressurized by the capillary tube 15b, and the refrigerant is further depressurized by the pressure adjusting device 4 to the state of the defrost depressurized refrigerant 46. This defrost reduced-pressure refrigerant 46 balances the pressure of the refrigerant flowing through the low-pressure side refrigerant circuit of the cooler performing the cooling operation. Thereby, an effect similar to that of the first embodiment can be obtained.

Embodiment 8 FIG. While performing a defrosting operation with at least one cooler of the refrigerator for a refrigerator and a refrigerator of each of the above embodiments, a cooling operation and a defrosting operation of performing a cooling operation with at least one other cooler coexist. Immediately after the frost operation is started, the process of fixing the expansion valve opening of the cooler performing another cooling operation for a certain period of time, and then releasing the opening so as to take a free opening is incorporated. While having the same effect, it is possible to further reduce the time required to balance the state of the refrigerant flowing through each of the cooler performing the defrosting operation and the cooler performing the cooling operation. Play.

Embodiment 9 While performing a defrosting operation with at least one cooler of the refrigerator for a refrigerator and a refrigerator of each of the above embodiments, a cooling operation and a defrosting operation of performing a cooling operation with at least one other cooler coexist. Immediately after the start of the frost operation, by incorporating a step of forcibly cooling the stopped cooler that is not performing the cooling operation or the defrosting operation with another cooler, the same effect as in the first embodiment can be obtained. In addition, since the compressor can be operated in a state closer to the rating, the time required for the defrosting operation due to an increase in the amount of hot gas supplied to the cooler performing the defrosting operation is further reduced. This has the effect that it is possible.

[0038]

As described above, the first aspect of the present invention connects a refrigerant compressor and a cooler for each circulation circuit in which the refrigerant circulates in the order of a refrigerant compressor, an air-cooled condenser, a liquid receiver, a liquid separator, and a cooler. A high-pressure refrigerant circuit for defrosting is provided, and a valve kit for switching between a cooling operation and a defrosting operation of a cooler is provided, so that either a cooling operation or a defrosting operation is selected for each circulation circuit, and a defrosting operation is mixed. Since the cooling operation can be continued in the defrosted state, it is not necessary to start and stop the compressor at the start of the defrosting operation, so that a stable operation can be performed, and a rise in the internal temperature of the refrigerator can be suppressed,
The cooling operation and the defrosting operation can be performed efficiently, and the freezer-refrigerator can be operated effectively.

According to a second aspect of the present invention, the valve kit includes an expansion valve, an electromagnetic valve for opening and closing a circuit for introducing a high-temperature and high-pressure refrigerant gas to the cooler as the cooler is defrosted, and a low-pressure side for discharging the refrigerant from the cooler. Since an electromagnetic valve connected in parallel to the capillary of the refrigerant circuit and an automatic control device for controlling the operation of each device are mounted, it is possible to efficiently perform a cooling operation and a defrosting operation, and a low-pressure side refrigerant circuit. The flowing refrigerant can be sufficiently vaporized and returned to the suction side of the compressor, and damage due to liquid compression of the compressor can be prevented.

According to a third aspect of the present invention, the valve kit includes an expansion valve, an electromagnetic valve for opening and closing a circuit for introducing a high-temperature and high-pressure refrigerant gas to the cooler as the cooler is defrosted, and a low-pressure side for discharging the refrigerant from the cooler. A pressure regulator connected to the refrigerant circuit;
Since the automatic control device for controlling the operation of each device is mounted, the cooling operation and the defrosting operation can be performed efficiently as in the second invention, and the refrigerant flowing through the low-pressure side refrigerant circuit can be sufficiently supplied. It can be vaporized and returned to the suction side of the compressor, and the reliability of the compressor in preventing damage due to liquid compression is improved.

Further, in the fourth invention, the liquid separator has a function of exchanging heat between the low-pressure refrigerant condensate generated by defrosting and the high-temperature and high-pressure refrigerant condensate. While achieving the effect, the cooling effect increases as the degree of supercooling of the refrigerant liquid on the high-pressure refrigerant side increases, thereby improving the energy use efficiency associated with the defrosting operation, and consequently energy saving. Such power costs can be reduced.

According to a fifth aspect of the present invention, an expansion valve for introducing high-pressure refrigerant liquid from a high-pressure side refrigerant circuit to a cooler is closed, and an electromagnetic valve for introducing high-temperature and high-pressure refrigerant gas from a high-pressure refrigerant circuit for defrosting to a cooler is opened. In addition, the solenoid valve of the low-pressure side refrigerant circuit connected in parallel with the capillary discharged from the cooler while restricting so as to vaporize the condensed refrigerant liquid in the cooler is closed, so that the cooling operation and the defrosting operation can be performed efficiently. In addition, it is possible to further prevent the large amount of refrigerant condensate from being returned to the compressor at a time, thereby improving the reliability of preventing damage due to liquid compression of the compressor.

According to a sixth aspect of the present invention, an expansion valve for introducing high-pressure refrigerant liquid from the high-pressure side refrigerant circuit to the cooler is closed, and an electromagnetic valve for introducing high-temperature and high-pressure refrigerant gas from the high-pressure refrigerant circuit for defrosting to the cooler is opened. In addition, since the amount of refrigerant discharged from the cooler is adjusted by adjusting the pressure regulator of the low pressure side refrigerant circuit so as to vaporize the condensed refrigerant liquid in the cooler, the cooling operation and the defrosting operation can be performed efficiently. In addition, it is possible to further prevent the large amount of refrigerant condensate from being returned to the compressor at a time, thereby improving the reliability of preventing damage due to liquid compression of the compressor.

A seventh aspect of the present invention is a high-pressure defrosting refrigerant for connecting a refrigerant compressor and a cooler for each circulation circuit in which the refrigerant circulates in the order of a refrigerant compressor, an air-cooled condenser, a liquid receiver, a liquid separator, and a cooler. A circuit is provided, and a cooling operation is performed by at least one other cooler while performing a defrosting operation by at least one cooler of a refrigerator for a refrigerator including a valve kit for switching a cooling operation and a defrosting operation of the cooler. Since the cooling operation and the defrosting operation to be performed are mixed, it is possible to effectively suppress the rise in the internal temperature during defrosting while maintaining the same effects as the above inventions, and to always maintain a good refrigerated state. .

According to an eighth aspect of the present invention, when defrosting a cooler provided with a condenser having a fan for blowing ambient air, the number of rotations or the number of operating fans is reduced to reduce the amount of air blown. As a result, the same effects as those of the above-described inventions can be obtained, and the time required for the defrosting operation can be further reduced.

According to a ninth aspect of the present invention, a liquid separator for exchanging heat between a low-pressure refrigerant condensate generated by defrosting and a high-temperature and high-pressure refrigerant condensate is provided by a liquid separator having a large surface area ratio between the inner surface and the outer surface of the heat transfer tube. Since the heat pipe is provided, the same effects as those of the inventions described above can be obtained, the energy use efficiency accompanying the defrosting operation can be improved, that is, energy can be saved, and the power cost of the cooling device can be reduced.

According to a tenth aspect of the present invention, there is provided a liquid separator for exchanging heat between a low-pressure refrigerant condensate generated by defrosting and a high-temperature and high-pressure refrigerant condensate. Has a large refrigerant flow ratio, the same effects as those of the above inventions are exhibited, the energy use efficiency associated with the defrosting operation can be improved, that is, energy saving can be achieved, and the power cost of the cooling device can be reduced.

According to an eleventh aspect of the present invention, the liquid separator for exchanging heat between the low-pressure refrigerant condensate generated by defrosting and the high-temperature and high-pressure refrigerant condensate includes the low-pressure refrigerant condensate and the high-pressure refrigerant condensate. Through the flow path in the same direction, or in the opposite direction, has the same effect as the above inventions, the improvement of energy utilization efficiency associated with the defrosting operation, that is, energy saving, The power cost related to the cooling device can be reduced.

According to a twelfth aspect, the refrigerant is a refrigerant compressor,
A high-pressure refrigerant circuit for defrosting that connects the refrigerant compressor and the cooler is provided for each circulation circuit that circulates in the order of the air-cooled condenser, the liquid receiver, the liquid separator, and the cooler, and a valve that switches between cooler cooling operation and defrost operation. The kit includes an expansion valve, an electromagnetic valve that opens and closes a circuit that introduces high-temperature and high-pressure refrigerant gas to the cooler as the cooler is defrosted, and an electromagnetic valve connected in parallel to the capillary of the low-pressure refrigerant circuit that discharges refrigerant from the cooler. And an automatic control device for controlling the operation of each of the above devices, and a pressure adjusting device is provided on a solenoid valve connected in parallel to the capillary of the low-pressure side refrigerant circuit. Therefore, the reliability of preventing damage due to liquid compression of the compressor is improved, the energy use efficiency associated with the defrosting operation is improved, and furthermore, energy saving can be achieved and the power cost related to the cooling device can be reduced.

According to a thirteenth aspect, a defrosting operation is performed by at least one cooler of a refrigerator for a refrigerator.
When the cooling operation for performing the cooling operation and the defrosting operation are mixed in at least one other cooler, the opening degree of the expansion valve of the cooler that is simultaneously cooling immediately after the start of the defrosting of the cooler is temporarily fixed. Therefore, the operation state of the entire cooling device associated with the defrosting operation can be stabilized in a shorter time.

According to a fourteenth aspect, a defrosting operation is performed by at least one cooler of a refrigerator for a refrigerator.
In at least one other cooler, when the cooling operation for performing the cooling operation and the defrosting operation are mixed, cooling is performed immediately after the start of the defrosting of the cooler, and the stopped cooler that is not performing the defrosting is forcibly cooled. Therefore, the same effects as those of the above inventions can be obtained, the reliability of prevention of damage due to liquid compression of the compressor can be improved, and the energy use efficiency associated with the defrosting operation can be improved. As a result, the power cost of the cooling device can be reduced.

[Brief description of the drawings]

FIG. 1 is a refrigerant circuit diagram showing a refrigerator for a refrigerator according to first to third embodiments of the present invention.

FIG. 2 is a refrigerant circuit diagram showing a refrigerator for a refrigerator according to a fourth embodiment of the present invention.

FIG. 3 is a refrigerant circuit diagram showing a refrigerator for a refrigerator according to embodiments 5 to 7 of the present invention.

FIG. 4 is a refrigerant circuit diagram showing a refrigerator for a refrigerator according to an eighth embodiment of the present invention.

FIG. 5 is a refrigerant circuit diagram showing a correspondence relationship between one operation state of the refrigerator for a refrigerator and a refrigerator according to the first and third embodiments of the present invention and a state of the refrigerant flowing through the circuit.

FIG. 6 is an explanatory diagram showing the relationship between one operating state of the refrigerator for refrigerators and refrigerators according to the first and third embodiments of the present invention and the pressure balance of the refrigerant flowing through the circuit in correspondence with a Mollier diagram.

FIG. 7 is an explanatory view showing an example of an arrangement of a conventional cooling device.

FIG. 8 is a refrigerant circuit diagram of a conventional cooling device.

FIG. 9 is an explanatory view schematically showing a heat transfer tube and a heat transfer fin of a cooler.

[Explanation of symbols]

1 refrigerator-freezer, 2 valve kit, 3 receiver, 4
Pressure regulator, 10 refrigerant compressor, 11 air-cooled condenser, 1
1a condenser fan, 12 cooler, 12a cooler fan, 13 refrigerant circuit, 13a expansion valve, 14 high pressure side refrigerant circuit, 14a low pressure refrigerant introduction circuit, 14b refrigerant supply branch point, 15 low pressure side refrigerant circuit, 15a solenoid valve, 15
b capillary, 15c pressure regulator, 16 high-pressure refrigerant circuit for defrost, 16a, 16b solenoid valve, 19 liquid separator,
19a low-pressure refrigerant gas suction port, 19b low-pressure refrigerant gas outlet, 19c high-pressure refrigerant side heat transfer tube, 19d low-pressure side auxiliary heat exchanger, 19e low-pressure refrigerant side flow path, 19f high-pressure refrigerant side flow path, 41 compressor suction gas, 42 Compressor discharge gas, 43 high-pressure condensate, 44 high-pressure subcoolant, 45 defrost condensate, 46 defrost reduced-pressure refrigerant, 47 low-pressure throttle refrigerant,
48 Low pressure superheated gas, 49 Low pressure combined refrigerant.

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Seishi Yokoyama 2-6-1 Otemachi, Chiyoda-ku, Tokyo Mitsui Electric Engineering Co., Ltd. (72) Inventor Fumio Matsuoka 2-3-2 Marunouchi, Chiyoda-ku, Tokyo No. Mitsubishi Electric Corporation (72) Inventor Satoru Hirakuni 2-3-2 Marunouchi, Chiyoda-ku, Tokyo Mitsubishi Electric Corporation

Claims (14)

[Claims] 1. A high-pressure defrosting refrigerant circuit for connecting a refrigerant compressor and a cooler is provided for each circulation circuit in which the refrigerant circulates in the order of a refrigerant compressor, an air-cooled condenser, a liquid receiver, a cooler, and a liquid separator; A refrigerator for a refrigerator comprising a valve kit for switching a cooling operation and a defrosting operation of a cooler. 2. The valve kit includes an expansion valve, an electromagnetic valve for opening and closing a circuit for introducing a high-temperature and high-pressure refrigerant gas to the cooler as the cooler is defrosted, and a capillary for a low-pressure side refrigerant circuit for discharging the refrigerant from the cooler. 2. The refrigerator according to claim 1, further comprising an electromagnetic valve connected in parallel, and an automatic control device for controlling an operation of each of the devices. 3. The valve kit is connected to an expansion valve, an electromagnetic valve for opening and closing a circuit for introducing a high-temperature and high-pressure refrigerant gas to the cooler as the cooler is defrosted, and a low-pressure side refrigerant circuit for discharging the refrigerant from the cooler. 2. The refrigerator according to claim 1, further comprising a pressure adjusting device and an automatic control device for controlling an operation of each device. 4. The refrigerator for a refrigerator according to claim 1, wherein the liquid separator has a function of exchanging heat between the low-pressure refrigerant condensate generated by defrosting and the high-temperature and high-pressure refrigerant condensate. Cooling system. 5. An expansion valve for introducing high-pressure refrigerant liquid from the high-pressure side refrigerant circuit to the cooler is closed, and an electromagnetic valve for introducing high-temperature and high-pressure refrigerant gas from the high-pressure refrigerant circuit for defrost to the cooler is opened. A defrosting method for a refrigerator for a freezer-refrigerator, comprising closing an electromagnetic valve of a low-pressure side refrigerant circuit connected in parallel with a capillary tube discharged from a cooler while constricting so as to vaporize the condensed refrigerant liquid. 6. An expansion valve for introducing high-pressure refrigerant liquid from the high-pressure side refrigerant circuit to the cooler is closed, and an electromagnetic valve for introducing high-temperature and high-pressure refrigerant gas from the high-pressure refrigerant circuit for defrost to the cooler is opened. A method for defrosting a cooling device for a freezer-refrigerator, comprising: adjusting a pressure adjusting device of a low-pressure side refrigerant circuit so as to vaporize the condensed refrigerant liquid to adjust a refrigerant amount discharged from a cooler. 7. A high-pressure defrosting refrigerant circuit connecting the refrigerant compressor and the cooler is provided for each circulation circuit in which the refrigerant circulates in the order of the refrigerant compressor, the air-cooled condenser, the liquid receiver, the cooler, and the liquid separator; While at least one cooler of a refrigerator for a refrigerator including a valve kit for switching between a cooling operation and a defrosting operation of a cooler performs a defrosting operation, at least one other cooler performs a cooling operation. A defrosting method for a refrigerator for a refrigerator comprising a mixture of frosting operations. 8. A condenser equipped with a fan for blowing ambient air, and when performing defrosting of a cooler, reducing the number of rotations or the number of operating fans to reduce the amount of air blown from the condenser. A method for defrosting a cooling device for a refrigerator-freezer, comprising: 9. A liquid separator for exchanging heat between a low-pressure refrigerant condensate generated by defrosting and a high-temperature and high-pressure refrigerant condensate,
A refrigerator for a refrigerator, comprising a heat transfer tube having a large ratio of the surface area of the inner surface to the outer surface of the heat transfer tube. 10. A liquid separator for exchanging heat between a low-pressure refrigerant condensate generated by defrosting and a high-temperature and high-pressure refrigerant condensate,
A refrigerator for a freezer-refrigerator, comprising: a refrigerant passage having a large ratio of a passage volume between a low-pressure refrigerant side and a high-pressure refrigerant side. 11. A liquid separator for exchanging heat between a low-pressure refrigerant condensate generated by defrosting and a high-temperature and high-pressure refrigerant condensate,
A refrigerator for a refrigerator-freezer having a structure capable of passing the low-pressure refrigerant condensate and the high-pressure refrigerant condensate through a flow path in the same direction or in opposite directions. 12. A high-pressure defrosting refrigerant circuit connecting the refrigerant compressor and the cooler is provided for each circulation circuit in which the refrigerant circulates in the order of the refrigerant compressor, the air-cooled condenser, the liquid receiver, the cooler, and the liquid separator, A valve kit that switches between cooler cooling operation and defrosting operation is an expansion valve, an electromagnetic valve that opens and closes a circuit that introduces high-temperature and high-pressure refrigerant gas to the cooler as the cooler defrosts, and a low-pressure side refrigerant that discharges refrigerant from the cooler. An electromagnetic valve connected in parallel with the capillary of the circuit, and an automatic control device for controlling the operation of each device are mounted, and further, a pressure regulator is connected to the electromagnetic valve connected in parallel with the capillary of the low-pressure side refrigerant circuit. A refrigerator for a refrigerator, comprising: 13. At least one of a refrigerator for a refrigerator and a refrigerator.
While performing defrosting operation with one cooler, at least one other
When the cooling operation and the defrosting operation that perform the cooling operation are mixed in the one cooler, the opening degree of the expansion valve of the cooler that is simultaneously cooling immediately after the start of the defrosting of the cooler is temporarily fixed. Defrosting method for refrigerator for refrigerator. 14. At least one of a refrigerator for a refrigerator and a refrigerator.
While performing defrosting operation with one cooler, at least one other
When the cooling operation and the defrosting operation that perform the cooling operation are mixed in the one cooler, it is necessary to simultaneously cool immediately after the start of the defrosting of the cooler and to forcibly enter the stopped cooler that is not performing the defrosting. A method for defrosting a refrigerator for a refrigerator.