WO2017051532A1

WO2017051532A1 - Cooling system and cooling method

Info

Publication number: WO2017051532A1
Application number: PCT/JP2016/004297
Authority: WO
Inventors: 寿人佐久間; 雅人矢野; 吉川　実; 正樹千葉
Original assignee: 日本電気株式会社
Priority date: 2015-09-25
Filing date: 2016-09-21
Publication date: 2017-03-30
Also published as: JPWO2017051532A1; US20180259232A1

Abstract

A cooling system that combines a plurality of refrigeration cycles has a fluctuating cooling capacity. Therefore, this cooling system has: a first cooling means comprising a first refrigerant transportation means that circulates a refrigerant that has received heat from an object to be cooled; a second refrigerant transportation means connected to the first refrigerant transportation means and circulating a diverted refrigerant being some of the refrigerant; a second cooling means that receives heat from the refrigerant that circulates through the first refrigerant transportation means and cools the diverted refrigerant; and a flowrate control means that controls the flowrate of the diverted refrigerant.

Description

Cooling system and cooling method

The present invention relates to a cooling system and a cooling method used for cooling electronic devices and the like, and more particularly to a cooling system and a cooling method using a phase change of a refrigerant.

In recent years, the heat generation amount and the heat generation density have increased with the downsizing and higher performance of electronic devices. In order to efficiently cool such electronic devices and the like, it is necessary to adopt a cooling method having a high cooling capacity. As one of cooling systems having a high cooling capacity, there is a cooling system using a phase change of a refrigerant.

An example of a cooling system using refrigerant phase change is described in Patent Document 1. The related refrigeration apparatus described in Patent Document 1 is a cooling system that combines a vapor compression refrigerator and an adsorption refrigerator.

The related refrigeration apparatus has an adsorption refrigerator having a first adsorber and a second adsorber, a first vapor compression refrigerator, and a second vapor compression refrigerator.

The first and second vapor compression refrigerators include a first and second compressor, first and second condensers (heat radiators), first and second decompressors, an evaporator, and first and second accumulators. Is provided. Note that the evaporators of the first and second vapor compression refrigerators are integrated.

Further, the adsorption refrigerator includes a first and second adsorber, a first and second adsorbent heat exchanger, a first and second water heat exchanger, an outdoor heat exchanger, and the like.

In the related refrigeration apparatus, the adsorbent in the adsorber in the regenerated state is heated by the first condenser provided in the first vapor compression refrigerator, and the second vapor compression is performed by the cooling action of the adsorber in the adsorbed state. The second condenser of the type refrigerator is cooled. The first adsorber and the second adsorber are switched between an adsorption state and a regeneration state in which the adsorbed vapor refrigerant is desorbed and regenerated at regular intervals.

By adopting such a configuration, the pressure in the condenser of the second vapor compression refrigeration machine can be reduced, so that the power (compression work) of the compressor of the second vapor compression refrigeration machine can be reduced. it can. Therefore, according to the related refrigeration apparatus, a sufficient refrigeration capacity can be obtained with a small amount of power in the refrigeration apparatus in which the first and second vapor compression refrigerators and the adsorption refrigerator are combined.

Further, as related technologies, there are technologies described in Patent Documents 2 and 3.

JP-A-11-190566 (paragraphs [0005] to [0019], FIG. 1) JP 2014-009624 A Japanese Patent Laid-Open No. 5-272833

As described above, the related refrigeration apparatus described in Patent Document 1 uses a second vapor compression refrigeration by an adsorption refrigerator that desorbs the adsorbed refrigerant using the exhaust heat of the first vapor compression refrigerator. It is set as the structure which cools the condenser with which a machine is equipped. Therefore, the cooling capacity of the second vapor compression refrigerator depends on the cooling capacity of the adsorption refrigerator and the first vapor compression refrigerator. As a result, the cooling capacity of the refrigeration apparatus is not always constant, and the cooling capacity varies depending on the ratio of the amount of refrigerant circulating through each of the first vapor compression refrigerator and the second vapor compression refrigerator.

As described above, in the cooling system in which a plurality of refrigeration cycles are combined, there is a problem that the cooling capacity of the cooling system varies.

An object of the present invention is to provide a cooling system and a cooling method that solve the above-mentioned problem that the cooling capacity of a cooling system varies in a cooling system that combines a plurality of refrigeration cycles.

The cooling system of the present invention includes a first cooling means having a first refrigerant transporting means for circulating a refrigerant received from a cooling target, and a branched refrigerant that is connected to the first refrigerant transporting means and is a part of the refrigerant. A second refrigerant transporting means that circulates, a second cooling means that receives heat from the refrigerant circulating through the first refrigerant transporting means and cools the branch refrigerant, and a flow rate control means that controls the flow rate of the branch refrigerant. Have.

The cooling method of the present invention circulates the refrigerant received from the object to be cooled, branches a part of the refrigerant, circulates the branched branch refrigerant, receives heat from the refrigerant, cools the branch refrigerant, Control is performed so that the cooling capacity for the object to be cooled is substantially constant.

According to the cooling system and the cooling method of the present invention, fluctuations in the cooling capacity of the cooling system can be suppressed even when the configuration is a combination of a plurality of refrigeration cycles.

It is the schematic which shows the structure of the cooling system which concerns on the 1st Embodiment of this invention. It is the schematic which shows the structure of the cooling system which concerns on the 2nd Embodiment of this invention. It is the schematic which shows another structure of the cooling system which concerns on the 2nd Embodiment of this invention. It is the schematic which shows another structure of the cooling system which concerns on the 2nd Embodiment of this invention.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[First Embodiment]
FIG. 1 is a schematic diagram showing a configuration of a cooling system 100 according to the first embodiment of the present invention. Broken line arrows in the figure indicate heat transfer.

The cooling system 100 according to the present embodiment includes a first cooling unit 110, a second cooling unit 120, a second refrigerant transporting unit 121, and a flow rate control unit 130.

1st cooling means 110 is provided with the 1st refrigerant transportation means 111 through which the refrigerant which received heat (H1) from cooling object 10 circulates. The second refrigerant transport means 121 is connected to the first refrigerant transport means 111, and a branched refrigerant that is a part of the refrigerant circulates. The second cooling means 120 receives heat (H2) from the refrigerant circulating in the first refrigerant transport means 111 and cools (H3) the branched refrigerant. Then, the flow rate control means 130 controls the flow rate of the branched refrigerant.

Here, the temperature of the branched refrigerant after being cooled by the second cooling means 120 depends not only on the cooling capacity of the second cooling means 120 but also on the flow rate of the branched refrigerant. Therefore, by controlling the flow rate of the branch refrigerant, the temperature of the branch refrigerant that flows back to the first refrigerant transport means 111 through the second refrigerant transport means 121 can be controlled. Thereby, even if the cooling capacity of the second cooling means 120 varies, it is possible to maintain the cooling capacity of the cooling system 100.

As described above, according to the cooling system 100 of the present embodiment, even when the cooling system 100 has a configuration in which a plurality of refrigeration cycles including the first cooling unit 110 and the second cooling unit 120 are combined, Variations in cooling capacity can be suppressed.

Here, the first cooling means 110 can be configured to use a vapor compression refrigeration cycle. Further, the second cooling means 120 can be configured to use either an adsorption refrigeration cycle or an absorption refrigeration cycle.

The flow rate control means 130 can be configured to control the flow rate of the branched refrigerant so that the temperature difference of the branched refrigerant before and after being cooled by the second cooling means 120 becomes substantially constant. Specifically, when the temperature difference of the branch refrigerant is larger than a predetermined value, the flow rate control means 130 increases the flow rate of the branch refrigerant. Conversely, when the temperature difference is smaller than a predetermined value, the flow rate control means 130 can be configured to control to decrease the flow rate of the branched refrigerant. Moreover, it is good also as a structure which controls the flow volume of a branch refrigerant | coolant so that the temperature difference of a branch refrigerant | coolant may become a predetermined range, for example, the range of 0 degreeC or more and 5 degrees C or less. Specifically, when the temperature difference of the branch refrigerant exceeds a predetermined range, the flow rate of the branch refrigerant may be increased, and when the temperature difference is within the predetermined range, the flow rate of the branch refrigerant may be decreased. Good.

Further, the flow rate control means 130 can be a flow rate control valve located in the flow path constituted by the first refrigerant transport means 111. Not limited to this, the flow rate control means 130 may be a flow rate control valve located in a flow path constituted by the second refrigerant transport means 121.

Next, the cooling method according to this embodiment will be described.

In the cooling method according to the present embodiment, first, the refrigerant that has received heat from the cooling target is circulated, a part of this refrigerant is branched, and the branched branched refrigerant is circulated. And while receiving heat from this refrigerant | coolant, a branch refrigerant | coolant is cooled. Here, the flow rate of the branching refrigerant is controlled so that the cooling capacity for the cooling target is substantially constant.

The control of the flow rate of the branching refrigerant described above can be configured to control the flow rate of the branching refrigerant so that the temperature difference between the branching refrigerant before and after the step of cooling the branching refrigerant becomes substantially constant. At this time, when the temperature difference is larger than a predetermined value, the flow rate of the branched refrigerant may be increased, and when the temperature difference is smaller than the predetermined value, the flow rate of the branched refrigerant may be decreased.

The step of receiving heat from the refrigerant and cooling the branched refrigerant may be a step of cooling the branched refrigerant by receiving heat from the refrigerant, desorbing the adsorbent, and evaporating the adsorbed adsorbent.

As described above, the cooling method according to the present embodiment has a configuration in which the refrigeration cycle in which the refrigerant received from the cooling target circulates and the refrigeration cycle that receives the heat from the refrigerant and cools the branched refrigerant are combined. And as above-mentioned, according to the cooling method of this embodiment, even if it is a case where it is the case where it is the case where it is the structure which combined such a some refrigeration cycle, the fluctuation | variation of cooling capacity can be suppressed.

[Second Embodiment]
Next, a second embodiment of the present invention will be described. FIG. 2 schematically shows the configuration of a cooling system 1000 according to the second embodiment of the present invention. In the figure, solid and broken arrows indicate the refrigerant flow, and white arrows indicate the heat flow.

The cooling system 1000 according to the present embodiment includes a first cooling device (first cooling means) 1100, a second cooling device (second cooling means) 1200, a second refrigerant transport unit (second refrigerant transport means). ) 1210 and a flow rate control valve (flow rate control means) 1300.

Here, the cooling system 1000 according to the present embodiment has a configuration in which a plurality of refrigeration cycles including the first cooling device 1100 and the second cooling device 1200 are combined. That is, the cooling system 1000 is an exhaust heat recovery type in which the second cooling device 1200 further cools the cooling target 10 using the heat recovered by the first cooling device 1100 cooling the cooling target 10 as an energy source. Cooling system. Here, the cooling target 10 is an electronic device such as a server.

The first cooling device 1100 includes an evaporator (evaporating means) 1110, a compressor (compressing means) 1120, a condenser (condensing means) 1130, an expansion valve (expanding means) 1140, and a first refrigerant transport section (first (Refrigerant transport means) 1150, and constitutes a vapor compression refrigeration cycle.

The evaporator 1110 is composed of a radiator or the like, and generates refrigerant vapor that is vaporized by receiving heat from the refrigerant. The compressor 1120 adiabatically compresses the refrigerant vapor to generate high-pressure refrigerant vapor. The condenser 1130 condenses the high-pressure refrigerant vapor to generate a high-pressure refrigerant liquid. The expansion valve 1140 expands the high-pressure refrigerant liquid to generate a low-pressure refrigerant liquid.

The first refrigerant transport unit 1150 constitutes a refrigerant flow path that returns from the evaporator 1110 to the evaporator 1110 via the compressor 1120, the condenser 1130, and the expansion valve 1140. A solid line arrow in FIG. 2 indicates the flow of the refrigerant.

The second cooling device 1200 constitutes either an adsorption refrigeration cycle or an absorption refrigeration cycle. In the present embodiment, a case where an adsorption refrigerator 1201 having an adsorption refrigeration cycle is used as the second cooling device 1200 will be described. The adsorption refrigerator 1201 circulates water or the like as a refrigerant with a pump 1202 and cools hot water with a cooling tower 1203 or the like. A broken-line arrow in FIG. 2 indicates a flow of water as a refrigerant of the adsorption refrigerator 1201.

The second refrigerant transport unit 1210 constitutes a flow path in which a branched refrigerant that is a part of the refrigerant circulates between the evaporator 1110 and the compressor 1120 and between the evaporator 1110 and the expansion valve 1140.

The condenser 1130 exchanges heat between the high-pressure refrigerant vapor flowing through the first refrigerant transport unit 1150 and the refrigerant on the heat receiving side of the second cooling device 1200. Further, a heat exchanger (heat exchanging means) 1220 for exchanging heat between the branched refrigerant circulated by the second refrigerant transport section 1210 and the refrigerant on the cooling side of the second cooling device 1200 can be provided.

The flow control valve 1300 controls the flow rate of the branched refrigerant. FIG. 2 shows a case where the flow control valve 1300 is located in a flow path constituted by the first refrigerant transport portion 1150. Not only this but as shown in FIG. 3, it is good also as a structure where the flow control valve 1301 is located in the flow path comprised by the 2nd refrigerant | coolant transport part 1210. FIG.

Next, the operation of the cooling system 1000 according to the present embodiment will be described.

First, the operation of the first cooling device 1100 will be described. The refrigerant liquid flowing into the evaporator 1110 made of a radiator or the like is vaporized by the exhaust heat of about 40 to 50 ° C. sent from the cooling target 10 such as a server and becomes refrigerant vapor. As the refrigerant vapor is adiabatically compressed by the compressor 1120, the pressure rises and the temperature of the refrigerant vapor rises to about 50 to 100 ° C. In order to use the heat of the refrigerant vapor whose temperature has risen in the second cooling device 1200, heat is exchanged between the refrigerant and water by the condenser 1130. As a result, the heat of the refrigerant moves to the water, hot water of about 50 to 100 ° C. is generated, and the temperature of the refrigerant decreases. The refrigerant condensed and liquefied as the temperature decreases is reduced in pressure by the expansion valve 1140. Thereafter, it flows again into the evaporator 1110.

Next, the operation of the second cooling device 1200 will be described. Heat is transferred to the adsorption refrigeration machine 1201 through hot water of about 50 to 100 ° C. received by heat exchange in the condenser 1130. The adsorption refrigeration machine 1201 generates cold water of about 5 to 20 ° C. using the warm heat, and cools the branched refrigerant via the heat exchanger 1220.

The branched refrigerant cooled by the heat exchanger 1220 is condensed and liquefied and circulated by the second refrigerant transport unit 1210. Since the second refrigerant transport unit 1210 is connected between the evaporator 1110 and the expansion valve 1140, the condensed and liquefied branch refrigerant merges with the refrigerant liquid whose pressure has been reduced by the expansion valve 1140, and returns to the evaporator 1110. . In addition, as shown in FIG. 2, it is good also as a structure provided with drive parts (drive means) 1230, such as a pump which circulates a branch refrigerant, in the flow path of the branch refrigerant which the 2nd refrigerant transport part 1210 comprises.

The refrigerant liquid returned to the evaporator 1110 is vaporized by exhaust heat from the cooling target 10 such as a server. The refrigerant vapor evaporated in the evaporator 1110 branches and flows into the second refrigerant transport part 1210 and the first refrigerant transport part 1150 connected between the evaporator 1110 and the compressor 1120. The branched refrigerant circulated by the second refrigerant transport unit 1210 flows into the heat exchanger 1220 again.

Next, the operation of the flow control valve 1300 will be described.

The flow control valve 1300 controls the flow rate of the branched refrigerant. That is, the flow control valve 1300 adjusts the ratio at which the refrigerant vapor vaporized in the evaporator 1110 branches to the first refrigerant transport part 1150 and the second refrigerant transport part 1210. As a result, the amount of refrigerant cooled by the condenser 1130 via the compressor 1120 included in the first cooling device 1100 and the branch cooled by the second cooling device 1200 via the second refrigerant transport unit 1210. The amount of refrigerant can be adjusted.

Further, the first thermometer 1221 that measures the temperature of the branched refrigerant on the inlet side of the heat exchanger 1220 and the second thermometer 1222 that measures the temperature of the branched refrigerant on the outlet side may be provided. The flow control valve 1300 is controlled using the pre-cooling refrigerant temperature T1 that is the measurement result of the first thermometer 1221 and the post-cooling refrigerant temperature T2 that is the measurement result of the second thermometer 1222. be able to.

A specific example of controlling the flow control valve 1300 will be described below.

If the amount of the branch refrigerant flowing into the heat exchanger 1220 is insufficient, the vapor of the branch refrigerant flowing into the heat exchanger 1220 is further subcooled after being condensed and liquefied, and therefore, the refrigerant temperature T1 before cooling and the refrigerant temperature T2 after cooling. The temperature difference T1-T2 increases. In this case, the flow rate control valve 1300 or the flow rate control valve 1301 is adjusted so that the temperature difference T1-T2 becomes constant at 5 degrees, for example.

Specifically, when the temperature difference T1−T2 becomes 5 ° C. or more (T1−T2 ≧ 5 ° C.), the opening degree of the flow control valve 1300 provided in the first refrigerant transport portion 1150 shown in FIG. Make it smaller. Alternatively, the opening degree of the flow control valve 1301 provided in the second refrigerant transport unit 1210 shown in FIG. 3 is increased. On the other hand, when the temperature difference T1−T2 is smaller than 5 ° C. (T1−T2 <5 ° C.), the opening degree of the flow control valve 1300 provided in the first refrigerant transport portion 1150 shown in FIG. 2 is increased. . Alternatively, the opening degree of the flow control valve 1301 provided in the second refrigerant transport unit 1210 shown in FIG. 3 is reduced.

By controlling the flow control valve 1300 in this way, the temperature of the branched refrigerant that flows back to the first refrigerant transport part 1150 through the second refrigerant transport part 1210 can be controlled. Thereby, even if the cooling capacity of the second cooling device 1200 varies, the cooling capacity of the cooling system 1000 can be maintained.

As described above, according to the cooling system 1000 of the present embodiment, fluctuations in the cooling capacity of the cooling system 1000 can be suppressed even when the cooling system 1000 is configured by combining a plurality of refrigeration cycles. That is, even if it is a case where it is the case where it is the case where it is the case where it is the structure which combined the some refrigeration cycle which consists of the 1st cooling device 1100 (vapor compression refrigeration cycle) and the 2nd cooling device 1200 (adsorption refrigeration cycle), the cooling capacity of the cooling system 1000 Fluctuations can be suppressed.

Further, as shown in FIG. 4, the heat exchanger 1220 may be positioned above the evaporator 1110. By adopting such a configuration, the branched refrigerant can flow through the second refrigerant transport portion 1210 and return to the evaporator 1110 by the action of gravity. This eliminates the need for a drive unit (drive means) such as the pump described above.

The present invention has been described above using the above-described embodiment as an exemplary example. However, the present invention is not limited to the above-described embodiment. That is, the present invention can apply various modes that can be understood by those skilled in the art within the scope of the present invention.

This application claims priority based on Japanese Patent Application No. 2015-188225 filed on September 25, 2015, the entire disclosure of which is incorporated herein.

DESCRIPTION OF SYMBOLS 100 Cooling system 110 1st cooling means 111 1st refrigerant | coolant transport means 120 2nd cooling means 121 2nd refrigerant transport means 130 Flow control means 1000 Cooling system 1100 1st cooling device 1110 Evaporator 1120 Compressor 1130 Condensation Vessel 1140 expansion valve 1150 first refrigerant transport unit 1200 second cooling device 1201 adsorption refrigerator 1202 pump 1203 cooling tower 1210 second refrigerant transport unit 1220 heat exchanger 1221 first thermometer 1222 second thermometer 1230

Drive unit

1300, 1301 Flow control valve 10 Cooling target

Claims

A first cooling means comprising a first refrigerant transport means for circulating the refrigerant received from the object to be cooled;
A second refrigerant transporting means connected to the first refrigerant transporting means, in which a branched refrigerant that is part of the refrigerant circulates;
Second cooling means for receiving heat from the refrigerant circulating in the first refrigerant transport means and cooling the branched refrigerant;
And a flow rate control means for controlling the flow rate of the branched refrigerant.
The cooling system according to claim 1,
The flow rate control means is a flow rate control valve located in a flow path constituted by the first refrigerant transport means. Cooling system.
The cooling system according to claim 1 or 2,
The flow rate control means is a flow rate control valve located in a flow path constituted by the second refrigerant transport means. Cooling system.
The cooling system according to any one of claims 1 to 3,
The cooling system that controls the flow rate of the branch refrigerant so that a temperature difference of the branch refrigerant before and after being cooled by the second cooling unit is within a predetermined range.
The cooling system according to claim 4, wherein
The flow rate control means is
If the temperature difference exceeds the predetermined range, increase the flow rate of the branch refrigerant,
A cooling system that reduces the flow rate of the branched refrigerant when the temperature difference is within the predetermined range.
The cooling system according to any one of claims 1 to 5,
The first cooling means constitutes a vapor compression refrigeration cycle,
Evaporating means for generating a refrigerant vapor vaporized by receiving heat from the refrigerant;
Compression means for compressing the refrigerant vapor to generate high-pressure refrigerant vapor;
Condensing means for condensing the high-pressure refrigerant vapor to produce a high-pressure refrigerant liquid;
Expansion means for expanding the high-pressure refrigerant liquid to generate a low-pressure refrigerant liquid,
The first refrigerant transport means constitutes a flow path for the refrigerant that flows back from the evaporation means to the evaporation means via the compression means, the condensation means, and the expansion means,
The cooling system, wherein the second refrigerant transport means constitutes a flow path through which the branched refrigerant circulates between the evaporation means and the expansion means between the evaporation means and the compression means.
The cooling system according to claim 6, wherein
Heat exchange means for exchanging heat between the branched refrigerant and the refrigerant on the cooling side of the second cooling means;
The condensing unit is a cooling system for exchanging heat between the high-pressure refrigerant vapor and a refrigerant on a heat receiving side of the second cooling unit.
The cooling system according to claim 7, wherein
The heat exchange means is located above the evaporation means.
The cooling system according to any one of claims 1 to 8,
The second cooling means constitutes one of an adsorption refrigeration cycle and an absorption refrigeration cycle.
The cooling system according to any one of claims 1 to 9,
A cooling system comprising driving means for circulating the branched refrigerant in the flow path of the branched refrigerant constituted by the second refrigerant transporting means.
Circulate the refrigerant that has received heat from the cooling target,
Branching a part of the refrigerant, circulating the branched refrigerant,
Receiving heat from the refrigerant and cooling the branched refrigerant;
A cooling method for controlling the flow rate of the branched refrigerant so that a cooling capacity for the cooling target is substantially constant.
The cooling method according to claim 11,
A cooling method in which the flow rate of the branch refrigerant is controlled so that a temperature difference between the branch refrigerant in the former stage and the latter stage of the step of cooling the branch refrigerant becomes substantially constant.
The cooling method according to claim 12, wherein
If the temperature difference is greater than a predetermined value, increase the flow rate of the branch refrigerant,
A cooling method that reduces the flow rate of the branched refrigerant when the temperature difference is smaller than a predetermined value.
The cooling method according to any one of claims 11 to 13,
A cooling method in which the branched refrigerant is cooled by receiving heat from the refrigerant, desorbing the adsorbent, and evaporating the desorbed adsorbent.