JP2003004346A - Cooling equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide cooling equipment enabling effective use of energy, while eliminating liquid compression of a compressor occurring on the occasion of a defrosting operation. SOLUTION: The cooling equipment 1 has a receiver tank 5 reserving a refrigerant coming out of a condenser 3. The condenser 3 and the receiver tank 5 are bypassed by bypass piping 6 for defrosting. The refrigerant coming out of a cooler 18 in the defrosting operation is evaporated so as to cool the receiver tank 5.

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 for cooling an open showcase or the like.

[0002]

2. Description of the Related Art Conventionally, a cooling device for cooling the inside of an open showcase or the like has a refrigerant circuit in which a compressor, a condenser, a receiver tank, a pressure reducing device, a cooler and the like are sequentially connected in an annular shape by piping. At the same time, a predetermined amount of refrigerant is enclosed in this refrigerant circuit. Then, when the compressor is operated, the refrigerant is compressed into a high temperature and high pressure gas state and flows into the condenser. In this condenser, the refrigerant radiates heat and is condensed and liquefied. Then, it is once stored in the receiver tank, then decompressed by the decompression device, and then supplied to the cooler. In this cooler, the refrigerant evaporates, and at that time, heat is absorbed from the surroundings to exert a cooling effect.

On the other hand, due to such cooling operation, frost is formed on the cooler and cooling efficiency is lowered, so that the defrosting operation is performed. In this defrosting operation, the high-temperature and high-pressure gas refrigerant discharged from the compressor is caused to flow into the cooler via the defrosting bypass pipe (bypassing the condenser and the receiver tank). The cooler is heated and defrosted by the inflow of the high-temperature refrigerant, while the refrigerant is condensed and liquefied.

[0004]

When the liquefied refrigerant is sucked into the compressor during such defrosting operation, the compressor is damaged by the liquid compression. Therefore, an accumulator or the like is arranged between the cooler and the compressor, and the liquefied refrigerant is temporarily stored in the accumulator and after being evaporated,
Although it is returned to the compressor, the energy (cooling capacity) of the refrigerant condensed by the defrosting of the cooler has been discarded without being used at present.

The present invention has been made in order to solve the technical problem, and it is possible to effectively use energy while eliminating the liquid compression of the compressor which occurs during the defrosting operation of the cooling device. To aim.

[0006]

In the cooling device of the present invention, a refrigerant circuit is composed of a compressor, a condenser, a pressure reducing device, a cooler, etc., and the high temperature refrigerant discharged from the compressor is transferred to the condenser. A cooling operation of condensing and depressurizing with the depressurizing device, and then flowing into the cooler to evaporate, and causing the high-temperature refrigerant discharged from the compressor to flow directly into the cooler via the defrosting bypass pipe. And a defrosting operation for defrosting the cooler, wherein during the defrosting operation, the refrigerant discharged from the cooler is evaporated, and the refrigerant circuit is bypassed by the defrosting bypass pipe. The high-pressure side of is cooled.

According to the present invention, a refrigerant circuit is composed of a compressor, a condenser, a decompressor, a cooler, etc., and the high-temperature refrigerant discharged from the compressor is condensed in the condenser, and the decompressor is supplied to the decompressor. After depressurizing by depressurizing, the cooling operation of flowing into the cooler to evaporate and the high temperature refrigerant discharged from the compressor are directly flown into the cooler via the defrosting bypass pipe to defrost the cooler. In the cooling device performing the defrosting operation, the refrigerant discharged from the cooler is evaporated during the defrosting operation so that the high pressure side of the refrigerant circuit bypassed by the defrosting bypass pipe is cooled. Because I configured
The refrigerant condensed and liquefied in the cooler during the defrosting operation of the cooling device is evaporated for cooling the high-pressure side, and the liquid refrigerant can be prevented or suppressed from being sucked into the compressor.

This makes it possible to avoid damage to the compressor due to liquid compression. Further, since the refrigerant staying on the high pressure side of the refrigerant circuit is cooled during the defrosting operation, the cooling capacity of the condensed refrigerant can be effectively utilized and the cooling capacity of the cooling device can be improved. Is.

In the cooling device of a second aspect of the invention, a receiver tank for storing the refrigerant discharged from the condenser is provided, and the defrosting bypass pipe bypasses the condenser and the receiver tank. During the defrosting operation, the refrigerant discharged from the cooler is evaporated to cool the receiver tank.

According to the invention of claim 2, in addition to the above,
A receiver tank for storing the refrigerant discharged from the condenser is provided, and the defrosting bypass pipe bypasses the condenser and the receiver tank, and evaporates the refrigerant discharged from the cooler during the defrosting operation, and the receiver. Since the tank is cooled, it is possible to more efficiently cool the high-pressure-side refrigerant by evaporating the liquid refrigerant from the cooler in the receiver tank.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a refrigerant circuit diagram of a cooling device 1 of the present invention.

The cooling device 1 of the embodiment is used for cooling the inside of a storage such as an open showcase, and is installed in a machine room such as a supermarket or a refrigerator 1A installed outdoors and in a store. It consists of an open showcase 1B.

The refrigerator 1A includes a compressor 2 and a condenser 3
A check valve 4, a receiver tank 5, a three-way valve 7 and a service valve 8 are provided, and they are sequentially connected by piping. Here, the check valve 4 is set in the forward direction on the receiver tank 5 side. An inlet of a defrosting bypass pipe 6 that bypasses the condenser tank 3 and the receiver tank 5 located on the high pressure side of the refrigerant circuit of the cooling device 1 is connected between the compressor 2 and the condenser 3. The outlet of the frost bypass pipe 6 is connected to one inlet 7B of the three-way valve 7. The other inlet 7A of the three-way valve 7 is connected to the outlet of the receiver tank 5, and the outlet 7C of the three-way valve 7 is the service valve 8
It is connected to the. The three-way valve 7 controls whether the refrigerant flows from one inlet 7B to the outlet 7C or the other inlet 7A to the outlet 7C.

A pipe 9 on the inlet side of the open showcase 1B is connected to the service valve 8, and a pipe 10 on the outlet side of the open showcase 1B is connected to the refrigerator 1A.
Is connected to the service valve 11. This service valve 11 is an inlet 12 of another three-way valve 12 of the refrigerator 1A.
Connected to A, one outlet 12B of this three-way valve 12 is
It is connected to the suction side of the compressor 2 by piping. The other outlet 12C of the three-way valve 12 is connected to the inlet of a pipe 13 for evaporating the liquid refrigerant.

This pipe 13 is for cooling the receiver tank 5 by evaporating the refrigerant discharged from the cooler 18 of the open showcase 1B, which will be described later, during the defrosting operation. Expansion valve 14 as
And the heat exchanger 15 provided in the receiver tank 5 are connected. The outlet of the pipe 13 is a three-way valve 12.
Is connected to the exit side of. The three-way valve 12 controls switching of whether the refrigerant flows from the inlet 12A to the outlet 12B or from the inlet 12A to the outlet 12C.

On the other hand, the open showcase 1B is
An electromagnetic valve 16 connected in series between the inlet side pipe 9 and the outlet side pipe 10, an expansion valve 17 as a pressure reducing device,
The cooler 18 is provided, and by this cooler 18,
Cool the inside of the open showcase 1B. Further, an expansion valve bypass pipe 19 is connected in parallel to the series circuit of the solenoid valve 16 and the expansion valve 17, and the expansion valve bypass pipe 19
An electromagnetic valve 20 is provided in the. The solenoid valve 16
The electromagnetic valve 20 controls whether the refrigerant flows through the expansion valve 17 or bypasses the expansion valve 17 and flows through the expansion valve bypass pipe 19.

The operation of the above arrangement will be described below. First, the cooling operation in the open showcase 1B will be described.

FIG. 2 shows the flow path of the refrigerant during this cooling operation by a thick line. In this case, the three-way valve 7 connects one inlet 7A and one outlet 7C by a controller (not shown),
Further, the three-way valve 12 connects the inlet 12A and one outlet 12B. Further, the solenoid valve 16 is opened and the solenoid valve 20 is closed.

When the compressor 2 is operated, a high-temperature and high-pressure gas refrigerant is discharged from the compressor 2 and flows into the condenser 3.
In this condenser 3, the refrigerant radiates heat and after condensing and liquefying,
It flows into the receiver tank 5 and is temporarily stored therein.
At this time, the three-way valve 7 has one inlet 7A and one outlet 7A as described above.
Since C is communicated, the refrigerant exiting the receiver tank 5 passes through the three-way valve 7, the service valve 8, and the pipe 9
Through the open showcase 1B.

The liquid refrigerant flowing into the open showcase 1B passes through the solenoid valve 16 and is decompressed by the expansion valve 17,
It flows into the cooler 18 and evaporates. The temperature of the cooler 18 decreases due to the endothermic action that occurs at this time. This cooler 1
The cool air that has exchanged heat with 8 is circulated in the open showcase 1B by a blower (not shown) to cool the inside.
The low-temperature gas refrigerant discharged from the cooler 18 passes through the pipe 10 and reaches the service valve 11. At this time, since the three-way valve 12 communicates the inlet 12A and the outlet 12B, the refrigerant is repeatedly circulated by returning to the compressor 2 via the three-way valve 12.

When such a cooling operation is executed, the air contained in the refrigerator, the articles, and the moisture contained in the outside air adhere to the cooler 18 as frost. When such frosting of the cooler 18 occurs, the cooling efficiency decreases, so that, for example, at a predetermined time, an operation (defrosting operation) of removing frost adhering to the cooler 18 is performed. FIG. 3 shows the flow path of the refrigerant during this defrosting operation with a thick line. In this case, the three-way valve 7 connects the one inlet 7B and one outlet 7C by the control device,
Further, the three-way valve 12 connects the inlet 12A and the one outlet 12C. The solenoid valve 16 is closed and the solenoid valve 20 is opened.

When the compressor 2 is operated in this state, a high-temperature and high-pressure gas refrigerant is discharged from the compressor 2, and this discharged high-temperature and high-pressure gas refrigerant flows into the defrosting bypass pipe 6 this time. Come to do. Since the three-way valve 7 communicates with the one inlet 7B and the one outlet 7C as described above, the high-temperature and high-pressure gas refrigerant exiting the defrosting bypass pipe 6 is the three-way valve 7
Through the service valve 8 and then into the open showcase 1B via the pipe 9.

The high temperature refrigerant that has flowed into the open showcase 1B then passes through the expansion valve bypass pipe 19 through the solenoid valve 20 and flows into the cooler 18. The cooler 18 is heated and defrosted by the inflow of the high-temperature and high-pressure refrigerant, while the inflowing refrigerant is condensed and liquefied. Cooler 1
The refrigerant condensed and liquefied in 8 passes through a pipe 10, a service valve 11, and a three-way valve 12. At this time, the three-way valve 1
Since 2 communicates with the inlet 12A and the outlet 12C, the refrigerant passes through the three-way valve 12 and flows into the pipe 13 for evaporating the liquid refrigerant.

The liquid refrigerant flowing into the pipe 13 is decompressed by the expansion valve 14 and then flows into the heat exchanger 15 provided in the receiver tank 5 to be evaporated. Due to the endothermic action occurring at this time, the liquid refrigerant stored in the receiver tank 5 during the previous cooling operation is cooled. Then, the low-temperature gas refrigerant discharged from the heat exchanger 15 is repeatedly circulated by returning to the compressor 2 via the pipe 13. And cooler 1
When the temperature of 8 reaches a predetermined defrosting end temperature, the control device communicates one inlet 7A and one outlet 7C of the three-way valve 7, and
The three-way valve 12 switches the flow path so that the inlet 12A and the one outlet 12B communicate with each other. Further, the solenoid valve 16 is opened and the solenoid valve 20 is closed. Thereby, the cooling operation is restored.

As described above, since the liquid refrigerant discharged from the cooler 18 during the defrosting operation is supplied to the heat exchanger 15 in the receiver tank 5 through the pipe 13 and evaporated there, the cooler 18 is provided. When the refrigerant condensed and liquefied by the compressor 2 is sucked into the compressor 2, the resulting liquid compression causes the compressor 2
It becomes possible to avoid the inconvenience of being damaged.

Further, since the refrigerant stored in the receiver tank 5 is cooled by the endothermic action generated in the heat exchanger 15 at this time, the liquid refrigerant stored in the receiver tank 5 during the previous cooling operation. Can be further cooled during the defrosting operation, the cooling capacity of the condensed refrigerant in the cooler 18 due to the defrosting operation can be effectively utilized, and the cooling capacity of the cooling device can be improved.

Although the open showcase has been described as an example in the embodiments, the present invention is not limited to this, and the present invention is also effective for home / commercial refrigerators and prefabricated refrigerators.

[0028]

As described in detail above, according to the present invention, a refrigerant circuit is composed of a compressor, a condenser, a decompression device, a cooler, etc., and the high temperature refrigerant discharged from the compressor is stored in the condenser. A cooling operation of condensing and depressurizing with the depressurizing device, and then flowing into the cooler to evaporate, and causing the high-temperature refrigerant discharged from the compressor to flow directly into the cooler via the defrosting bypass pipe. In a cooling device for performing a defrosting operation for defrosting the cooler, during the defrosting operation, the refrigerant discharged from the cooler is evaporated, and the refrigerant circuit bypassed by the defrosting bypass pipe is used. Since it is configured to cool the high pressure side, the refrigerant condensed and liquefied in the cooler during the defrosting operation of the cooling device is evaporated to cool the high pressure side, and the liquid refrigerant is prevented from being sucked into the compressor, or Can be suppressed So as to.

This makes it possible to avoid damage to the compressor due to liquid compression. Further, since the refrigerant staying on the high pressure side of the refrigerant circuit is cooled during the defrosting operation, the cooling capacity of the condensed refrigerant can be effectively utilized and the cooling capacity of the cooling device can be improved. Is.

According to the invention of claim 2, in addition to the above,
A receiver tank for storing the refrigerant discharged from the condenser is provided, and the defrosting bypass pipe bypasses the condenser and the receiver tank, and evaporates the refrigerant discharged from the cooler during the defrosting operation, and the receiver. Since the tank is cooled, it is possible to more efficiently cool the high-pressure-side refrigerant by evaporating the liquid refrigerant from the cooler in the receiver tank.

[Brief description of drawings]

FIG. 1 is a refrigerant circuit diagram of a cooling device as an embodiment to which the present invention is applied.

FIG. 2 is a refrigerant circuit diagram illustrating a refrigerant flow path during a cooling operation of the cooling device of FIG.

FIG. 3 is a refrigerant circuit diagram illustrating a refrigerant flow path during a defrosting operation of the cooling device of FIG.

[Explanation of symbols]

1 Cooling device 2 compressor 3 condenser 4 Check valve 5 receiver tank 6 Defrosting bypass piping 7, 12 three-way valve 13 Piping 15 heat exchanger 16, 20 solenoid valve 18 Cooler 19 Solenoid valve bypass piping

Claims (2)

[Claims] 1. A refrigerant circuit comprising a compressor, a condenser, a decompressor, a cooler, etc., after condensing high-temperature refrigerant discharged from the compressor in the condenser and decompressing it in the decompressor. , A cooling operation of flowing into the cooler and evaporating, and a defrosting operation of directly flowing the high-temperature refrigerant discharged from the compressor into the cooler via a defrosting bypass pipe to defrost the cooler. In the cooling device for performing the defrosting operation, the refrigerant discharged from the cooler is evaporated, and the high pressure side of the refrigerant circuit bypassed by the defrosting bypass pipe is cooled. apparatus. 2. A receiver tank for storing the refrigerant discharged from the condenser, wherein the defrosting bypass pipe bypasses the condenser and the receiver tank,
Evaporate the refrigerant that has come out of the cooler during the defrosting operation,
The cooling device according to claim 1, wherein the receiver tank is cooled.