JPS62280559A - Refrigerator - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] 3. Detailed Description of the Invention [Field of Industrial Application] This invention provides a first refrigeration cycle for cooling an object to be cooled, and a method for supercooling a liquid refrigerant in this refrigeration cycle. The present invention relates to a refrigeration system including a second refrigeration cycle.

[Conventional technology]

3 is a refrigerant circuit configuration diagram of the conventional refrigeration apparatus shown in FIG. 2. FIG.

In FIG. 2, 1 is the first refrigeration cycle;
The refrigeration cycle 1 includes a first compressor 2 and a first condenser 3.
, a first throttle device 4, and a first evaporator 5 provided in a refrigerator or the like are connected in this order, and between the first compressor 2 and the first condenser 3 and the first throttle device 4 are connected. A normally closed solenoid valve 7 is provided in a bypass circuit 6 whose intake and outlet are connected between the first evaporator 5 and the first evaporator 5 . 11 is a second refrigeration cycle, and the second refrigeration cycle 11 has a second compressor 12, a second condenser 13, a second throttle device 14, and a second evaporator 14 connected in this order. , the second evaporator 14 is arranged to exchange heat with the refrigerant flowing in the liquid pipe 8 between the first cE condenser 3 and the first throttling device 4 of the first refrigeration cycle 1. .

Next, the operation of the conventional refrigeration system configured as described above will be explained. In the first refrigeration cycle 1, high-temperature, high-pressure gas refrigerant discharged from the first compressor 2 flows as shown by the solid arrow, is condensed in the first condenser 3, and then passes through the liquid pipe 8. It reaches the first throttle device 4, where it is depressurized and reaches the first evaporator 5, where it evaporates to cool objects to be cooled, such as items stored in the refrigerator, and the first evaporator 5. The exiting gas refrigerant returns to compression m2. In addition, the solenoid valve 7 provided in the bypass circuit 6 is opened (by which the high-temperature, high-pressure gas refrigerant discharged from the first compressor 1 is directly sent to the first evaporator 5 via the bypass circuit 6, and the evaporator Perform step 5 defrosting.Second
In the refrigeration cycle 11, a high-temperature, high-pressure gas refrigerant discharged from the second compressor 12 flows as shown by the solid arrow, is condensed in the second condenser 13, and then passes through the second throttle device 1.
4, where the pressure is reduced and the liquid refrigerant reaches the second evaporator 15, where it absorbs heat from the liquid refrigerant in the liquid pipe 8 of the first refrigeration cycle 1, is evaporated, and returns to the second compressor 12.

In such a refrigeration system, the relatively high temperature liquid refrigerant in the first refrigeration cycle 1 is cooled by the second refrigeration cycle 11, thereby increasing the cooling capacity of the first refrigeration cycle 1. The second refrigeration cycle 11 operates with a high evaporation temperature, that is, with a high coefficient of performance, and therefore has higher efficiency than a single refrigeration cycle with the same cooling capacity.

[Problem that the invention seeks to solve]

However, in the conventional refrigeration system as described above, it is necessary to stop the second refrigeration cycle 11 when defrosting the first evaporator 5, and the heating power of the first refrigerant cycle 1 alone is sufficient to perform the first evaporation. Since the container 5 is defrosted, the defrosting performance is poor and defrosting takes a long time. This means that while the first evaporator 5 has a heat exchange capacity corresponding to the sum of the cooling capacities of the first and second refrigeration cycles 1.11, the first evaporator 5 This is because it can only supply a heating power of .

This invention was made to solve the above-mentioned problems, and when the first refrigeration cycle is defrosted, the first
and by supplying the heating power of the second refrigeration cycle,
It is an object of the present invention to provide a refrigeration device that has high defrosting efficiency and can defrost a first evaporator in a short time.

[Means for solving problems]

In the refrigeration system of the present invention, the inlet side of the bypass circuit is connected to a liquid receiver provided between the first condenser and the first throttling device of the first refrigeration cycle, and the second refrigeration cycle has four-way switching. valve and the first. The heat pump type has a second heat exchanger, and the second heat exchanger of the second refrigeration cycle is disposed in a heat exchange relationship with the liquid refrigerant in the liquid receiver, and During defrosting operation, the second heat exchanger is used as a condenser and the gas refrigerant in the liquid receiver is supplied to the first evaporator.

[Effect]

The refrigeration system according to the present invention switches the second refrigeration cycle to a heating operation cycle during the defrosting operation of the first refrigeration cycle, and uses the high temperature and high pressure gas refrigerant in the second heat exchanger to cool the first refrigeration cycle. By heating the refrigerant in the liquid receiver and defrosting the first evaporator using the refrigerant in the liquid receiver as a gas refrigerant, the second evaporator is heated during the defrosting operation of the first refrigeration cycle. The defrosting efficiency can be increased by supplying heating power for the refrigeration cycle.

〔Example〕

An embodiment of the present invention will be described below with reference to FIG.

In FIG. 1, the same parts as in FIG. 2 indicate the same or equivalent parts, and 9 is a liquid receiver provided between the first condenser 3 and the first throttle device 4; High-temperature gas refrigerant is supplied to the first evaporator 5 through an inlet 9a of the liquid refrigerant condensed in the first condenser 3, an outlet 9b that supplies the liquid refrigerant to the first throttle device 4, and a bypass circuit 6. gas outlet 9
C is provided. 16 is a four-way switching valve provided in the second refrigeration cycle 11 of the heat pump type, and is used to switch the refrigeration cycle 11 between a cooling cycle and a heating cycle; 17 and 18 are four-way switching valves provided in the second refrigeration cycle 11; The second heat exchanger 18 is arranged in a heat exchange relationship with the liquid refrigerant in the liquid receiver 9 . The configuration of this embodiment other than the above is the same as that of the conventional one shown in FIG.

Next, the operation of the refrigeration system according to this embodiment will be explained. During cooling operation, in the first refrigeration cycle 1, the first
The high-temperature, high-pressure gas refrigerant discharged from the compressor 2 flows as shown by the solid arrow, is condensed in the first condenser 3, and then flows into the receiver 9. After that, the liquid refrigerant reaches the first throttle device 4, where it is depressurized and reaches the first evaporator 5,
Here, it is evaporated and returned to the first compressor 2. In the second refrigeration cycle 11, the high-temperature, high-pressure gas refrigerant discharged from the second compressor 12 reaches the four-way switching valve 16, and flows as shown by the solid line arrow during cooling operation. That is, the gas refrigerant discharged from the second compressor 12 is transferred to the first heat exchanger 17.
After being condensed, the pressure is reduced in the second throttle device 14, and the second
It is evaporated in the heat exchanger 18 and returned to the second compressor 12.

During this cooling operation, the liquid refrigerant in the first refrigeration cycle 1 in the liquid receiver 9 is cooled by the refrigerant in the second heat exchanger 18, and its enthalpy is reduced. Therefore, in the first evaporator 5, the total cooling capacity of the first and second compressors 2°12 is exhibited, and the evaporation temperature of the refrigerant in the second refrigeration cycle 11 is high, so that the coefficient of performance is improved. This results in high cooling operation.

In addition, during defrosting operation, in the first refrigeration cycle 1, when frost forms on the first evaporator 5, a frost detection device (not shown) operates, the solenoid valve 7 opens, and at the same time, the first condenser 3 A cooling device (not shown) such as a blower attached to the unit stops.

Therefore, the high-temperature, high-pressure gas refrigerant discharged from the first compressor 2 reaches the liquid receiver 9 with almost no heat dissipation in the first condenser 3, and passes through the bypass circuit 6 from the gas outlet 9c to the second condenser 3. The frost in the first evaporator 5 is melted and the air returns to the first compressor 2. In the second refrigeration cycle 11, the four-way switching valve 16 is switched in response to a signal from the operation of the frost detection device, and the refrigerant flows as shown by the broken line arrow. That is, the high-temperature, high-pressure gas refrigerant discharged from the second compressor 12 passes through the four-way switching valve 16, is condensed in the second heat exchanger 18, and then passes through the second expansion device 1.
4, the air is evaporated in the first heat exchanger 17, and returned to the second compressor 12. During this defrosting operation, the liquid refrigerant in the receiver 9 is heated and boiled by the refrigerant in the second heat exchanger 18, and is mixed with the high temperature gas refrigerant flowing through the first condenser 3. , is supplied to the first evaporator 5 via the bypass circuit 6, and defrosts the evaporator 5.

〔Effect of the invention〕

As explained above, according to the present invention, there is provided a first refrigeration cycle and a second heat exchanger that is in a heat exchange relationship with the refrigerant in the liquid receiver on the high pressure side provided in the first refrigeration cycle. The second refrigeration cycle is equipped with a heat pump-type second refrigeration cycle, in which the second heat exchanger is used as an evaporator during cooling operation, and the second heat exchanger is used as a condenser during defrosting operation. As a result, highly efficient cooling operation can be performed, and the defrosting performance can be greatly improved and the defrosting time can be shortened.

[Brief explanation of the drawing]

FIG. 1 is a refrigerant circuit configuration diagram showing a refrigeration system according to an embodiment of the present invention, and FIG. 2 is a refrigerant circuit configuration diagram showing a conventional refrigeration system. 1... First refrigeration cycle, 2... First compressor,
3... first condenser, 4... first throttle device, 5...
...first evaporator, 6...bypass circuit, 7...electromagnetic valve, 9...liquid receiver, 11...second refrigeration cycle, 12...second compressor, 14... Second expansion device, 16... Four-way switching valve, 17... First heat exchanger,
18...Second heat exchanger. Note that the same reference numerals in the figures indicate the same or corresponding parts.

Claims (1)

[Claims] A first compressor, a first condenser, a liquid receiver, a first throttle device, and a first evaporator are connected in sequence, and the liquid receiver and the first
a first refrigeration cycle equipped with a bypass circuit that connects the inlet side of the evaporator and supplies gas refrigerant in the receiver to the first evaporator during defrosting of the evaporator; and a second compressor; A four-way switching valve, a first heat exchanger, a second throttling device, and a liquid refrigerant in the liquid receiver are arranged in a heat exchange relationship, and when the first refrigeration cycle is in cooling operation, the evaporator is used for defrosting operation. A refrigeration system characterized in that it is equipped with a heat pump type second refrigeration cycle having a second heat exchanger that sometimes serves as a condenser.