JP6048792B2 - Refrigerant circulation cooling system - Google Patents

Description

  The present invention relates to a refrigerant circulation cooling system, and more specifically, the refrigerant can be stably returned from the cooler to the receiver regardless of the number of installed coolers or the load fluctuation of the cooler, and the cost. The present invention relates to a refrigerant circulation cooling system that can achieve reduction and installation space reduction.

In recent years, a carbon dioxide refrigerant is frequently used for cooling or refrigeration because of a small environmental load, and a refrigerant circulation system using a liquid head difference due to gravity is also employed.
Such a refrigerant circulation system includes a cooler, a receiver that receives carbon dioxide refrigerant, a feed pipe that sends liquid phase carbon dioxide refrigerant from the receiver to the cooler, and a vapor phase that performs cooling by evaporating in the cooler. The receiver is arranged above the cooler because the coolant is circulated using a gravity pipe and the return pipe for returning the carbon dioxide refrigerant from the cooler to the receiver.

Since such a refrigerant circulation system does not require a compressor and does not perform superheat control, carbon dioxide refrigerant is mixed in a two-phase mixture of liquid phase and gas phase in the return pipe from the cooler to the receiver. It may be in a state.
In order to return only the refrigerant gas from the refrigerant in such a two-phase mixed state to the receiver, the following techniques are conventionally employed.

First, a concentrator that performs a gas-liquid separation function is attached to the cooler.
The concentrator is, for example, an integrated vertical liquid separator, and has a liquid reservoir at the bottom and a liquid separator at the top, and a liquid return pipe connected to the cooler is connected to the liquid reservoir. The liquid reservoir is provided with a float switch for detecting whether or not the liquid refrigerant forming the accumulated liquid has reached a specified level.
With such a concentrator, the liquid refrigerant is separated from the refrigerant from the cooler, and only the gas is returned to the receiver. The liquid refrigerant is forcibly sent to the cooler, for example, via a liquid return pipe by a liquid pump. I am doing so.

Secondly, a so-called double riser, triple riser or the like is used.
For example, the double riser includes a first riser pipe having a small diameter corresponding to the minimum load of the cooler, and a second riser pipe having a large diameter connected to the lower portion of the first riser pipe via a U-shaped trap. When the load is small, liquid refrigerant accumulates in the trap and returns the liquid refrigerant to the receiver via the first riser pipe, while when the load is large, via the first riser pipe and the second riser pipe The liquid refrigerant is returned to the receiver.

However, such conventional techniques have the following technical problems.
First, the refrigerant return to the receiver becomes unstable.
More specifically, when a plurality of coolers are provided or when the load fluctuation in the cooler is large, the number of concentrators or riser pipes is required accordingly, and the operation reliability decreases accordingly. In some cases, the refrigerant return to the receiver may become unstable.

Secondly, the cost of the cooling system is increased and the occupied space is increased.
More specifically, installing a concentrator for each cooler increases costs and occupies a correspondingly large space. On the other hand, a double riser or the like keeps the refrigerant in two phases without gas-liquid separation. If it is returned, the energy loss is large and the operating cost is increased.

  In view of the above technical problems, the object of the present invention is to stably return the refrigerant from the cooler to the receiver regardless of the number of installed coolers or the load fluctuation of the cooler, and cost. An object of the present invention is to provide a refrigerant circulation system that can achieve reduction and installation space reduction.

In order to achieve the above object, the refrigerant circulation cooling system of the present invention includes:
In the refrigerant circulation cooling system for circulating the refrigerant,
A cooler that cools by the latent heat of vaporization of the refrigerant;
A receiver installed above the cooler and receiving a refrigerant;
A return pipe for returning the refrigerant from the cooler to the receiver;
A feed pipe for sending refrigerant from the receiver to the cooler;
The return pipe has a rising portion from the cooler toward the receiver,
The rising portion has such a diameter that the liquid refrigerant falls in the return pipe due to its own weight.

According to the refrigerant circulation cooling system having the above configuration, the refrigerant in the receiver is sent to the cooler installed below the receiver through the feed pipe by circulation, and there is, for example, the cooler by the latent heat of vaporization of the refrigerant. It is possible to cool the installed space.
When the refrigerant cooled in the cooler is in a two-phase state of a gas phase and a liquid phase, when returning such a refrigerant to the receiver via the return pipe, the return pipe has a rising portion directed from the cooler to the receiver. The rising portion has a diameter that allows the liquid refrigerant to fall due to its own weight in the return pipe, so that the liquid refrigerant can be stored in the return pipe by simply adjusting the diameter of the return pipe. For example, even when a plurality of coolers are installed or when the load fluctuation of the cooler changes variously, the refrigerant can be returned regardless of the number of installed coolers or the load fluctuation of the cooler. Can be stably returned from the cooler to the receiver, and the cost of the cooling system and the installation space can be reduced.

The refrigerant may be any one of carbon dioxide, chlorofluorocarbon, and ammonia.
Furthermore, a plurality of the coolers are provided in a form in which at least those installed at different installation levels exist,
The rising portion rises from a lower level than the cooler installed at the bottom, to an upper level than the cooler installed at the top, and to an upper level than the receiver,
The rising portion is connected to a return branch pipe extending from each of the plurality of coolers,
The diameter of the rising portion may be increased from the lowermost portion of the rising portion to the upper side in accordance with the connecting portion with the return branch pipe.

Furthermore, a plurality of the coolers are provided in a form in which the cooling load for each cooler varies within the same cooling space,
The rising portion rises from a lower level than the cooler installed at the bottom,
Connected to a return branch pipe extending from each of the plurality of coolers;
The diameter of the rising portion may be increased in accordance with the load fluctuation of the cooler.
In addition, a liquid pot is provided at the bottom of the return pipe to store a liquid refrigerant that falls due to its own weight, and a liquid return pipe that connects the liquid pot and the receiver is further provided. In addition, a liquid pump for feeding the liquid refrigerant accumulated in the liquid pot to the receiver may be provided.

Furthermore, a liquid pot for storing a liquid refrigerant that falls due to its own weight is provided at the bottom of the return pipe, and a liquid return pipe that connects the liquid pot and the cooler is further provided. In addition, a liquid pump for feeding the liquid refrigerant accumulated in the liquid pot to the cooler may be provided.
Furthermore, the liquid return pipe is connected to the return pipe connected to the receiver, and the return pipe is configured to return liquid refrigerant accumulated in the liquid pot to the receiver or to the cooler. A switching valve may be provided.
In addition, the liquid pot is further provided with a heating source that uses exhaust heat, and the liquid refrigerant that accumulates in the liquid pot is heated and gasified, and returned to the receiver via the rising portion. Good.

Further, a condenser of a combination of one or more of an evaporation type, an air cooling type, and a water cooling type may be further provided, and the gaseous refrigerant in the receiver may be condensed by the condenser.
Furthermore, a cascade condenser using a secondary refrigerant may be further provided, and the gaseous refrigerant in the receiver may be condensed by the latent heat of evaporation of the secondary refrigerant via the cascade condenser.
In addition, a liquid pump may be installed in the feed pipe, and the refrigerant may be forcibly circulated between the receiver and the cooler by the return pipe and the feed pipe.

Further, the refrigerant may be naturally circulated between the receiver and the cooler using the liquid head difference due to gravity between the receiver and the cooler by the return pipe and the feed pipe. .

Below, refrigerant circulation cooling system 10 of a 1st embodiment of the present invention is explained in detail, referring to drawings.
Carbon dioxide is used as a refrigerant, and a space space SP such as a warehouse is an object to be cooled.
As shown in FIG. 1, the refrigerant circulation cooling system 10 includes a plurality of coolers 12 (two in the drawing) that cool by the latent heat of vaporization of the refrigerant, and a dioxide dioxide that is installed at an upper level than the plurality of coolers 12. The carbon receiver 14, the first piping system 16 connecting between the plurality of coolers 12 and the carbon dioxide receiver 14, the cascade condenser 18, the compressor 20, the condenser 22, the carbon dioxide receiver 14, and the cascade condenser 18, a second piping system 24 that connects between the two and the third piping system 26 that connects between the cascade capacitor 18 and the compressor 20.

A plurality of coolers 12 are provided in a form in which at least those installed at different installation levels exist.
More specifically, FIG. 2 illustrates the arrangement state of the cooler 12 of FIG. 1 in more detail, and shows a situation where one cooler 12 is installed in each of the four space spaces SP1 to SP4. Show. More specifically, in SP1 and SP2 which are upper space spaces, a cooler 12AA is installed for SP1 and a cooler 12AB is installed for SP2, while in SP3 and SP4 which are lower space spaces, SP3 On the other hand, a cooler 12BB is installed for the coolers 12BA and SP4.
The first piping system 16 includes a return pipe 28 that returns the refrigerant from each cooler 12 to the carbon dioxide receiver 14, and a feed pipe 30 that sends the refrigerant from the carbon dioxide receiver 14 to the cooler 12. The rising portion 32 from the cooler 12 toward the carbon dioxide receiver 14 has a diameter such that the liquid refrigerant falls in the return pipe 28 due to its own weight.
More specifically, the return pipe 28 is connected to the gas phase part at the upper part of the carbon dioxide receiver 14, and the rising part 32 described later has two return branch pipes 34 connected at one end to the respective coolers 12. The main connection is made, and the connection level of the two return branch pipes 34 to the rising portion 32 differs depending on the installation level of the cooler 12.

On the other hand, two feed branch pipes 38 connected to the respective coolers 12 via the regulating valve 36 are connected to the feed pipe 30. Control valve 36
The amount of liquid fed to the cooler 12 can be controlled by adjusting the opening.
A liquid pump 40 is installed in the feed pipe 30, and carbon dioxide refrigerant is forcibly circulated between the carbon dioxide receiver 14 and the cooler 12 by the return pipe 28 and the feed pipe 30. As a modification, the liquid head due to gravity between the carbon dioxide receiver 14 and the cooler 12 and between the carbon dioxide receiver 14 and the cooler 12 is provided by the return pipe 28 and the feed pipe 30 without providing the liquid pump 40. The carbon dioxide refrigerant may be naturally circulated using the difference. In this case, the level difference between the plurality of coolers 12 and the carbon dioxide receiver 14 may be determined from the viewpoint of the circulation flow rate of the carbon dioxide refrigerant that is required.

With the above configuration, the liquid carbon dioxide refrigerant from the carbon dioxide receiver 14 is sent to the corresponding cooler 12 via the feed pipe 30 via the feed pipe 30 by the liquid pump 40, and each cooler 12. , The gaseous carbon dioxide refrigerant cooled by the latent heat of vaporization is returned to the carbon dioxide receiver 14 via the corresponding return branch pipe 34 and the rising portion 32 and the return pipe 28 to form the refrigerant circulation cooling system 10. Like to do.

Here, the rising portion 32 will be described. As shown in FIG. 2 (B), the rising portion 32 is integrated with the return pipe 28 and is located at a lower level than the cooler 12B installed at the lowermost portion. It rises to a level above the installed cooler 12A and to a level above the carbon dioxide receiver 14. As described above, the rising portion 32 is connected to the return branch pipe 34 extending from each of the plurality of coolers 12, and the diameter of the rising portion 32 is the same as that of the return branch pipe 34 from the bottom of the rising portion 32 upward. The diameter is increased according to the connecting portion.
More specifically, the connection from the lowermost part of the rising part 32 to the connection part 42 with the rising part 32 of the return branch pipe 34 of the cooler 12B, and the connection part 42 with the rising part 32 of the return branch pipe 34 of the cooler 12A. If the diameters of the rising portions 32 up to the portion 44 and above the connecting portion 44 are D1, D2, and D3, D1 <D2 <D3. As a result, the flow rate of the carbon dioxide refrigerant returned from the cooler 12 to the rising portion 32 via the corresponding return branch pipe 34 is combined with the flow rate from the respective coolers 12, so that the level of the rising portion 32 is increased. Accordingly, the liquid carbon dioxide refrigerant mixed with the gaseous carbon dioxide refrigerant is adjusted by adjusting the diameter of the rising portion 32 to make the flow rate of the carbon dioxide refrigerant substantially constant. However, no matter where the rising part 32 flows, it is returned to the lowermost part of the rising part 32 so that the liquid carbon dioxide refrigerant does not return to the carbon dioxide receiver 14. Therefore, each of D1, D2, and D3 may be determined from such a viewpoint.

As shown in FIG. 2, a liquid pot 46 for storing liquid carbon dioxide refrigerant that falls by its own weight is provided at the bottom of the rising portion 32 of the return pipe 28, and the liquid that connects the liquid pot 46 and the carbon dioxide receiver 14. A return pipe 47 is further provided. The liquid return pipe 47 is provided with a liquid pump 43 for feeding the liquid refrigerant accumulated in the liquid pot 46 to the carbon dioxide receiver 14 and a switching valve 73. Further, a level switch 49 is provided in the vicinity of the liquid pot 46 so that the amount of liquid carbon dioxide refrigerant accumulated in the liquid pot 46 can be monitored. As a result, when a certain amount of liquid carbon dioxide refrigerant has accumulated in the liquid pot 46, the liquid pump 43 returns the liquid carbon dioxide refrigerant to the carbon dioxide receiver 14 via the liquid return pipe. A bypass pipe 75 is provided between the liquid return pipe 47 and the feed pipe 30 via a switching valve 71, and liquid carbon dioxide refrigerant from the liquid return pipe 47 is supplied to the feed pipe 30 via the bypass pipe 75. You may make it send to each cooler 12 without returning to the carbon dioxide receiver 14 suitably.
As a modification, a plurality of coolers 12 are provided in a form in which the cooling load for each cooler 12 varies within the same cooling space, and the rising portion 32 rises from a lower level than the cooler 12 installed at the bottom. The diameter of the rising portion 32 may be increased in accordance with the load fluctuation of the cooler 12. The return branch pipe 34 extends from each of the coolers 12. More specifically, after grasping the range of the load fluctuation of the cooler 12 in advance, the liquid carbon dioxide refrigerant is surely self-weighted toward the liquid pot 46 according to the fluctuation range of the flow rate of the carbon dioxide refrigerant corresponding thereto. It should just fall by.

As a further modification, as shown in FIG. 3, a liquid pot 46 for storing a liquid refrigerant that falls by its own weight is provided at the lowermost portion of the return pipe 28, and the liquid pot 46 is connected to the coolers 12BA and BB. A return pipe 48 may be further provided, and the liquid return pipe 48 may be provided with a liquid pump 41 for feeding the liquid refrigerant accumulated in the liquid pot 46 to the coolers 12BA and BB. In this case, when a certain amount of liquid carbon dioxide is accumulated in the liquid pot 46, the switching valve 51 is closed and the liquid carbon dioxide accumulated in the liquid pot 46 is sent directly to the coolers 12BA and BB, while the coolers 12AA, You may make it send the liquid carbon dioxide of the carbon dioxide receiver 14 from AB through the liquid pump 40 from the carbon dioxide receiver 14 to AB. For example, when the load of the cooler 12 increases and the liquid carbon dioxide accumulated in the liquid pot 46 is also used for cooling, the switching valve 51 is opened, and the liquid carbon dioxide is returned to the liquid return pipe 48 by the liquid pump 41. The liquid may be fed directly to the coolers 12A and B via When liquid carbon dioxide is fed from the carbon dioxide receiver 14 to the coolers 12A and B only through the liquid pump 40, the liquid carbon dioxide does not flow into the liquid return pipe 48 by opening the switching valve 51. As described above, the liquid return pipe 48 may be provided with a switching valve (not shown).

As another modification, as shown in FIG. 4, the liquid pot 46 is further provided with a heating source 50 of a type that uses exhaust heat, and the liquid carbon dioxide refrigerant accumulated in the liquid pot 46 is heated and gasified. The carbon dioxide receiver 14 may be returned via the rising portion 32. Thereby, you may utilize the exhaust heat of a heater or a refrigerator as a heating source, for example.

Referring to the secondary side, as shown in FIG. 1, a cascade condenser 18 using a secondary refrigerant is further provided, and the gaseous state in the carbon dioxide receiver 14 is generated by the latent heat of evaporation of the secondary refrigerant via the cascade condenser 18. Carbon dioxide refrigerant is condensed. A conventionally known refrigerant may be used as the secondary refrigerant. More specifically, in the cascade condenser 18, the gaseous carbon dioxide refrigerant from the carbon dioxide receiver 14 is cooled by the secondary refrigerant, and the liquid carbon dioxide refrigerant is returned to the carbon dioxide receiver 14, while the heated secondary refrigerant is After being compressed by the compressor 20, it is condensed by the cooling water in the condenser 22 and is sent again to the cascade condenser 18 through the expansion valve 53.
According to the refrigerant circulation cooling system 10 having the above configuration, the refrigerant in the carbon dioxide receiver 14 is circulated through the feed pipe 30 toward the cooler 12 installed below the carbon dioxide receiver 14, and there. For example, the space where the cooler 12 is installed can be cooled by the latent heat of vaporization of the refrigerant.
When the refrigerant cooled in the cooler 12 is in a two-phase state of a gas phase and a liquid phase, when returning to the carbon dioxide receiver 14 through such a return pipe 28, the return pipe 28 is connected to the cooler 12. A rising portion 32 directed to the carbon dioxide receiver 14 is provided, and the rising portion 32 has a diameter such that the liquid refrigerant falls in the return pipe 28 due to its own weight. Therefore, the diameter of the return pipe 28 is simply adjusted. Thus, the liquid refrigerant can be stored in the return pipe 28 and only the gaseous refrigerant can be returned to the carbon dioxide receiver 14. For example, even when a plurality of coolers 12 are installed or the load fluctuations of the coolers 12 vary variously. The refrigerant can be stably returned from the cooler 12 to the carbon dioxide receiver 14 regardless of the number of installed coolers 12 or the load fluctuation of the cooler 12. Moni, reduction of cost and installation space of the cooling system is achieved.

Hereinafter, a second embodiment of the present invention will be described with reference to FIG. In the following description, the same components as those in the first embodiment are denoted by the same reference numerals, and the description thereof will be omitted. Hereinafter, the characteristic portions of the present embodiment will be described in detail.
The characteristic part of this embodiment is that the secondary side is different from that of the first embodiment. In the first embodiment, a cascade condenser 18 using a secondary refrigerant is further provided, and through the cascade condenser 18, the latent heat of evaporation of the secondary refrigerant is provided. The gaseous refrigerant in the carbon dioxide receiver 14 is condensed, but in this embodiment, the primary refrigerant is directly compressed by the compressor 20 without using the secondary refrigerant, and is evaporated, air-cooled, or water-cooled. A condenser 22 of a combination of one or more of the equations is further provided, the liquid primary refrigerant condensed by the condenser 22 is stored in the high-pressure receiver 62, and the low-pressure liquid primary refrigerant is reduced to low pressure via the expansion valve 53. The liquid is stored in the receiver 60 and fed to the cooler 12 via the liquid pump 40.

More specifically, instead of the carbon dioxide receiver in the first embodiment, a low-pressure receiver 60 is arranged, and further, the compressor 20, the condenser 22, the high-pressure receiver 62, and the expansion valve 53 are arranged in this order, and each is a pipe. When the primary refrigerant (carbon dioxide) evaporated in each cooler 12 is returned to the low-pressure receiver 60 via the return pipe 28 on the primary side, the gaseous primary refrigerant is compressed into the compressor 20. In the condenser 22, it is cooled and condensed by cooling water in the condenser 22, and the condensed primary refrigerant is sent to the high-pressure receiver 62, and the liquid primary refrigerant passes through the expansion valve 53, and the low-pressure receiver 60. To be returned to.
As in the first embodiment, the rising portion 32 on the primary side is provided with a liquid pot 46, and the liquid primary refrigerant is directly returned to the low-pressure receiver 60 by the liquid return pipe 47, or the liquid pot 46 is provided to return the liquid. After the liquid primary refrigerant is returned to the cooler 12 by the pipe 47 or the liquid pot 46 is provided, the liquid primary refrigerant accumulated in the liquid pot 46 is gasified by the heating source 50 using exhaust heat, and the rising portion 32 It may be returned to the low-pressure receiver 60 via

The embodiments of the present invention have been described in detail above, but various modifications or changes can be made by those skilled in the art without departing from the scope of the present invention.
For example, in the present embodiment, the rising portion 32 in the return pipe 28 has been described as being integral with the return pipe 28, but the present invention is not limited thereto, and is provided separately from the return pipe 28, for example, welded to the return pipe 28. It may be fixed.

For example, in the present embodiment, a case has been described in which a plurality of coolers 12 having different installation levels are used, or a plurality of coolers 12 having the same installation level but varying loads are used. Without being limited thereto, the present invention may be applied to cases where load fluctuations occur individually in the plurality of coolers 12 having different installation levels.
For example, in this embodiment, although demonstrated as an air-conditioning system which cools a room | chamber interior, you may utilize as a cooling system which cools to-be-cooled objects, such as a drink, for example, without being limited to it.
For example, in the present embodiment, the refrigerant has been described as adopting carbon dioxide as a natural refrigerant from the viewpoint of environmental conservation. However, the present invention is not limited to this. Good.

1 is an overall configuration diagram of a refrigerant circulation cooling system 10 according to a first embodiment of the present invention. FIG. 2B is a partial view showing details of the return pipe of the refrigerant circulation cooling system 10 according to the first embodiment of the present invention, and FIG. 2B is a partial detailed view showing details of the rising portion 32. It is a figure which shows the modification of the rising part 32 of the liquid return piping 48 of the refrigerant | coolant circulation cooling system 10 which concerns on 1st Embodiment of this invention. It is a figure which shows the modification of the rising part 32 of the liquid return piping 48 of the refrigerant | coolant circulation cooling system 10 which concerns on 1st Embodiment of this invention. It is a whole block diagram of the refrigerant | coolant circulation cooling system 10 which concerns on 2nd Embodiment of this invention.

D: Diameter of return pipe 10 Refrigerant circulation cooling system 12 Cooler 14 Carbon dioxide receiver 18 Cascade condenser 20 Compressor 22 Condenser 28 Return pipe 30 Feed pipe 32 Rising part 34 Return branch pipe 36 Adjustment valve 38 Feed branch pipe 40 Liquid pump 43 Liquid pump 46 Liquid pot 47 Liquid return pipe 48 Liquid return pipe 49 Level switch 50 Heating source 51 Switching valve 53 Expansion valve 60 Low pressure receiver 62 High pressure receiver

Claims (10)

In the refrigerant circulation cooling system for circulating the refrigerant, a cooler that cools by the latent heat of vaporization of the refrigerant, a receiver that is installed above the cooler and receives the refrigerant, and a return pipe that returns the refrigerant from the cooler to the receiver A feed pipe that sends a refrigerant from the receiver to the cooler, and the return pipe has a rising portion that faces the receiver from the cooler,
A plurality of the coolers are provided in a form in which there are at least those installed at different installation levels, and the riser is installed at the top from the lower level than the cooler installed at the bottom. Rise to a higher level and higher than the receiver,
The rising portion is connected to a return branch pipe extending from each of the plurality of coolers, and the diameter of the rising portion is such that the liquid refrigerant falls by its own weight in the return pipe, and only the gaseous refrigerant returns to the receiver. In order to have a large diameter, from the lowest part of the rising part upwards, the diameter is increased according to the connecting part with the return branch pipe,
A refrigerant circulation cooling system characterized by that. The refrigerant circulation cooling system according to claim 1, wherein the refrigerant is any one of carbon dioxide, a fluorocarbon, and ammonia. At the bottom of the return pipe, a liquid pot is provided for storing a liquid refrigerant falling due to its own weight, and a liquid return pipe for connecting the liquid pot and the receiver is further provided. The liquid return pipe includes a liquid pot. The refrigerant circulation cooling system according to claim 1, further comprising: a liquid pump that feeds liquid refrigerant accumulated in the receiver to the receiver. At the bottom of the return pipe, a liquid pot is provided for storing a liquid refrigerant that falls due to its own weight, and a liquid return pipe that connects the liquid pot and the cooler is further provided. The refrigerant circulation cooling system according to claim 1, further comprising a liquid pump for feeding liquid refrigerant accumulated in the pot to the cooler. The liquid return pipe is connected to the return pipe connected to the receiver, and the return pipe has a switching valve for returning liquid refrigerant accumulated in the liquid pot to the receiver or returning to the cooler. The refrigerant circulation cooling system according to claim 4 provided. The liquid pot is further provided with a heating source of a type that uses exhaust heat, the liquid refrigerant accumulated in the liquid pot is heated and gasified, and returned to the receiver via the rising portion. The refrigerant circulation cooling system described. The condenser according to one or more of evaporative, air-cooled, and water-cooled is further provided, and the gaseous refrigerant in the receiver is condensed by the condenser. The refrigerant circulation cooling system according to claim 1. A cascade condenser using a secondary refrigerant is further provided, and the gaseous refrigerant in the receiver is condensed by the latent heat of evaporation of the secondary refrigerant through the cascade condenser. The refrigerant circulation cooling system described. The refrigerant circulation cooling system according to claim 1, wherein a liquid pump is installed in the feed pipe, and the refrigerant is forcibly circulated between the receiver and the cooler by the return pipe and the feed pipe. The refrigerant is naturally circulated between the receiver and the cooler by using the liquid head difference due to gravity between the receiver and the cooler by the return pipe and the feed pipe. The refrigerant circulation cooling system described.

Images