JPS583012Y2 - Refrigeration equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a refrigeration system for a refrigerator having a water-cooled condenser, and moreover, is capable of defrosting an air-cooled evaporator by reverse cycle operation.

In refrigeration equipment, it is already known that the evaporator is defrosted by reversing the circulation direction of the refrigerant, but during this reverse cycle defrosting operation, the condenser temporarily acts as an evaporator, so the condenser If the device is water-cooled, the cooling water will freeze.

For these reasons, in conventional refrigeration systems, it has not been possible to employ a reverse cycle defrosting system when the condenser is water-cooled.

This invention enables reverse cycle defrosting operation while preventing cooling water from freezing even when the condenser is water-cooled. A water storage tank is provided in the high-temperature cooling water pipe leading from the condenser to the cooling tower, while the outlet side of the water tank bypasses the cooling tower and directly communicates with the low-temperature cooling water pipe, and is opened and closed by a control valve. A bypass pipe is installed to prevent defrosting.
The object of this invention is to provide a refrigeration system in which high-temperature cooling water in the water storage tank is directly returned to the condenser through the bypass pipe so that it can be used as a heat source.

The refrigeration system of the present invention will be described below with reference to the illustrated embodiment. In the figure, reference numeral 30 indicates a refrigerant circulation circuit in the refrigeration apparatus, and 20 indicates a cooling water circulation circuit for the water-cooled condenser 12. .

First, an overview of the refrigerant circulation circuit 30 will be explained. During normal refrigeration operation, the refrigerant circulates as shown by the solid line arrow X, and during reverse cycle defrosting operation, the refrigerant circulates as shown by the broken line arrow Y.

That is, during the refrigeration operation, the high temperature gas refrigerant discharged from the compressor 10 passes through the conduit A1, the four-way switching valve 11, and the conduit B to the water-cooled condenser 12, where it is cooled and liquefied.

The refrigerant liquefied in the condenser 12 passes through the check valve 14 in the conduit C1 and the expansion valve 15 in the conduit F through the conduit E, where it is depressurized and then transferred to the conduit G. and flows into the air-cooled evaporator 13.

The refrigerant that has flowed into the evaporator 13 evaporates to cool the air inside the refrigerator 9, and then returns to the compressor 10 through the pipe H1, the four-way switching valve 11, and the pipe J.

If the refrigeration operation is performed for a certain period of time (for example, one hour) or more, a large amount of frost will form on the evaporator 13, so in order to remove this frost, the four-way selector valve 11 must be operated to perform a reverse cycle defrosting operation. become.

In this case, the high temperature gas refrigerant discharged from the compressor 10 is supplied to the evaporator 13 side, and the frost adhering to the evaporator 13 is melted and removed, and the gas refrigerant is liquefied.

This liquid refrigerant passes through the pipe G, the check valve 16, and the expansion valve 17, and reaches the condenser 12, where it absorbs heat from the cooling water and evaporates. through compressor 1
It refluxes to 0.

Next, to explain the outline of the cooling water circulation circuit 20, in this cooling water circulation circuit 20, a condenser 1 is connected to a high temperature cooling water pipe 21 leading from a condenser 12 to a cooling tower 3 that cools the cooling water.
A certain amount (for example, 30 tons) of high temperature cooling water flowing out from 2.
A water storage tank 1 is provided for storing water.

The cooling water cooled in the cooling tower 3 is supplied to the condenser 12 by the pump 4 through the low temperature cooling water pipe 22.

Further, the outlet side of the water storage tank 1 provided on the high temperature cooling water pipe 21 side and the low temperature cooling water pipe 22 are connected by a bypass pipe 5 that bypasses the cooling tower 3.

A control valve 2 consisting of a three-way valve is provided at the branching part of the high-temperature cooling water pipe 21 and the bypass pipe 5, and as will be described later, this control valve 2 controls the water temperature of the water storage tank 1 to a predetermined temperature during defrosting operation. When the temperature drops to below, all high temperature cooling water is transferred to the cooling tower 3.
The switching operation is such that the cooling water is bypassed and directly flows to the low temperature cooling water pipe 22 side.

That is, the operation of the control valve 2 is controlled by the regulator 8. In this embodiment, the regulator 8 detects the temperature of the cooling water in the water storage tank 1 using the detection device 7, so that the temperature of the cooling water reaches a predetermined temperature ( For example, when the temperature drops below 20° C., the control valve 2 is switched or the opening degree is adjusted so that the high-temperature cooling water flows through the bypass pipe 5 to the low-temperature cooling water pipe 22 side.

Next, to explain the interaction between the refrigerant circulation circuit 30 and the cooling water circulation circuit 20, when the refrigerant circulation circuit 30 side is performing normal refrigeration operation (the refrigerant flows in the direction of the solid line arrow X), the interaction between the cooling water circulation circuit 30 and the cooling water circulation circuit 20 On the side, the cooling water circulates in the order shown by the solid arrow X, that is, the condenser 12, the water tank 1, the control valve 2, the cooling tower 3, the pump 4, and the condenser 12.

In the illustrated embodiment, even during normal refrigeration operation, the hot water tank 1
If the temperature of the cooling water inside the tank drops (below 20"C),
The regulator 8 operates the control valve 2 to allow all of the high temperature cooling water to flow to the bypass pipe 5 side.

That is, if the temperature of the cooling water drops too much, the condensing pressure in the condenser 12 will drop, and as a result, the evaporation pressure in the evaporator 13 will drop, so there is a risk that liquid backflow to the compressor 10 will occur.

However, according to the illustrated embodiment, when the temperature of the cooling water drops below a predetermined temperature, the cooling water bypasses the cooling tower 3 and flows, so high temperature cooling water flows to the condenser 12.
Therefore, the condensing pressure of the condenser 12 does not drop below a predetermined level, so that such a liquid back phenomenon can be prevented.

Next, when the refrigerant circulation circuit 30 side switches to reverse cycle defrosting operation, the condenser 12 temporarily acts as an evaporator,
The refrigerant absorbs heat from the cooling water flowing into the condenser 12 and serves as the main heat source for defrosting.

On the other hand, the temperature of the cooling water drops rapidly, and when the temperature of the cooling water drops below 20°C, the detection device 7 detects this, and the regulator 8 operates the control valve 2 to direct the cooling water to the bypass pipe 5 side. Distribute the entire amount of cooling water.

As a result, the high-temperature cooling water in the water storage tank 1 bypasses the cooling tower 3 and is directly supplied to the condenser 12, which prevents the cooling water from freezing in the condenser 12 and provides sufficient cooling to the evaporator 13. A heat source for frost can be provided.

In addition, in the method of the present invention, the cooling water in the water storage tank 1 is heated by the waste heat of condensation during normal refrigeration operation, and this waste heat is used as a heat source for defrosting. This brings about a big advantage in that the exhaust heat from the refrigeration equipment can be used effectively.

The capacity of the water storage tank 1 can be appropriately designed depending on the refrigeration capacity of the refrigeration system (for example, about 30 tons for a refrigeration system with an output of 3 horsepower).

A description of the illustrated embodiment is given above, but
When implementing the present invention, the following configurations can be added or changed.

(1) The control valve 2 is controlled by a timer regardless of the temperature of the cooling water in the hot water tank 1.

For example, after one hour of freezing operation, seven ten minutes of reverse cycle defrosting operation are performed, and the control valve 2 is controlled to open and close accordingly.

(2) The control valve 2 may be provided in the middle of the bypass pipe 5.

In this case, all or part of the cooling water flowing out of the condenser 12 may be bypassed to the bypass pipe 5.

In the figure, reference numeral 9 indicates a refrigerator, and 18 and 19 indicate temperature-sensitive cylinders.

Next, to explain the effect of the present invention, the refrigeration system of the present invention has a water storage tank 1 for pooling high temperature cooling water in the cooling water circulation circuit 20 for the condenser 12, and reverse cycle defrosting operation is performed in the refrigeration system. Since the high-temperature cooling water is sometimes supplied to the condenser 12 through the bypass pipe 5 and used as a heat source during defrosting operation, freezing of the cooling water in the condenser 12 is prevented. Moreover, since the heat of the high-temperature cooling water supplied to the refrigerant through the condenser 12 promotes the defrosting action in the evaporator 13, the time of reverse cycle defrosting operation is shortened as much as possible. The refrigeration equipment can be operated efficiently.

In addition, the heat held by the high-temperature cooling water in the water storage tank 1 was originally discarded as waste heat, but in this invention, this heat is used as a heat source for defrosting, and it can be used as a heat source for defrosting. This eliminates the need for a heat source and also eliminates the need for wiring for an electric heater, which has the effect of contributing to reducing the cost of the entire device.

Incidentally, if the control valve 2 is operated as the temperature of the cooling water in the water tank 1 decreases as in the illustrated embodiment,
Particularly in winter, the condensation pressure during normal refrigeration operation can be lowered to a predetermined value or less and can be adjusted by 7 degrees, thereby preventing the liquid back phenomenon.

[Brief explanation of the drawing]

The figure is a refrigerant and cooling water circuit diagram of a refrigeration system according to an embodiment of the present invention. 1...Water tank, 2...Control valve, 3...
... Cooling tower, 5 ... Bypass pipe, 8 ...
... Regulator, 10... Compressor, 11...
...Four-way switching valve, 12...Condenser, 13...
... Evaporator, 20 ... Cooling water circulation circuit, 21
...High temperature cooling water pipe line, 22...Low temperature cooling water pipe line, 30...Refrigerant circulation circuit.

Claims (1)

[Scope of utility model registration request] This refrigeration system has a compressor 10, a four-way switching valve 11, a water-cooled condenser 12, and an air-cooled evaporator 13, and cools the air inside the refrigerator 9 with the evaporator 13. A refrigerant circulation circuit 30 is constructed which can supply high temperature gas refrigerant to the evaporator 13 by switching the four-way switching valve 11 during defrosting operation, and a cooling water circulation circuit 20 is used to cool the condenser 12. A water storage tank 1 is provided in the high-temperature cooling water pipe 21 leading from the condenser 12 to the cooling tower 3, while a water storage tank 1 is provided at the outlet side of the water storage tank 1 to bypass the cooling tower 3 and directly connect to the low-temperature cooling water pipe 22. A bypass pipe 5 is provided which communicates with the evaporator 13 and is opened and closed by a control valve 2. During defrosting operation for the evaporator 13, the high temperature cooling water in the water storage tank 1 is transferred to the bypass pipe 5 and low temperature cooling by operating the control valve 2. A refrigeration system characterized in that water is directly refluxed to the condenser 12 through a water pipe 22.