US20190145667A1

US20190145667A1 - Heat exchange device, refrigeration system, and heat exchange method

Info

Publication number: US20190145667A1
Application number: US16/089,994
Authority: US
Inventors: Arihiro Matsunaga; Minoru Yoshikawa; Hisato Sakuma; Masato Yano; Asuka MATSUBA; Takafumi NATSUMEDA
Original assignee: NEC Corp
Current assignee: NEC Corp
Priority date: 2016-03-31
Filing date: 2017-03-23
Publication date: 2019-05-16
Also published as: JP6888616B2; JPWO2017170139A1; WO2017170139A1

Abstract

Since improving heat exchange between a gas-phase refrigerant and a liquid-phase refrigerant in a refrigeration system could instead result in a reduction in the efficiency of the whole refrigeration system, a heat exchange device (201) of the present invention includes: a refrigerant supply means (210) for supplying a first-temperature liquid-phase refrigerant (R11) and a second-temperature gas-phase refrigerant (R12) in one circulation system; a plurality of heat exchange means (220A, 220B) which are each configured so as to perform heat exchange between the liquid-phase refrigerant and the gas-phase refrigerant; and refrigerant circulation means (231, 232, 242) for circulating the gas-phase refrigerant (R12) in such a manner that the gas-phase refrigerant (R12) flows in parallel in the plurality of heat exchange means, and circulating the liquid-phase refrigerant (R11) in such a manner that the liquid-phase refrigerant (R11) flows in series in the plurality of heat exchange means.

Description

TECHNICAL FIELD

The present invention relates to a heat exchange device and a heat exchange method, in particular the heat exchange device and the heat exchange method used for a refrigeration system.

BACKGROUND ART

A refrigeration system which transports heat by using change in a state of a refrigerant is widely used in air conditioning facilities. Patent Literature 1 describes one example of such refrigeration system.
In the related refrigeration system described in Patent Literature 1, a refrigeration cycle is applied to an automobile air conditioning device. The related refrigeration system includes a compressor, a condenser, a receiver, an internal heat exchanger, an expansion valve, an evaporator, and a control valve.
Here, the compressor compresses a refrigerant.
The condenser condenses the compressed refrigerant by heat exchange with outside air.
The receiver separates the condensed refrigerant into gas and liquid and saves a surplus refrigerant in the refrigeration cycle.
The expansion valve is a thermostatic expansion valve and performs throttle expansion of gas-liquid separated liquid refrigerant.
The evaporator evaporates the expanded refrigerant by heat exchange with air in the inside of the automobile
The internal heat exchanger includes a high-pressure path through which a high-temperature and high-pressure refrigerant flows to the expansion valve and low-pressure path through which a low-pressure refrigerant flow to the compressor, and performs heat exchange between the high-temperature refrigerant which flows in the high-pressure path and the low-temperature refrigerant which flows in the low-pressure path. Thereby, the refrigerant which flows in the high-pressure path is supercooled by the refrigerant in the low-pressure path, and the refrigerant which flows in the low-pressure path is overheated by the refrigerant in the high-pressure path. Efficiency of the refrigeration cycle can be therefore improved.
The control valve adjusts a degree of overheating of the low-pressure refrigerant which is transferred from the internal heat exchanger to the compressor.
A double tube which is placed between the expansion valve and the control valve functions as the internal heat exchanger.
The double tube includes an inner tube and an outer tube which are concentrically arranged so the outer tube encloses the inner tube.
When the high-pressure refrigerant flows in the inner tube and the low-pressure refrigerant flows between the outer tube and the inner tube, heat exchange between the high-pressure refrigerant and the low-pressure refrigerant is performed through the inner tube.
In the related refrigeration system, if the control valve is adjusted so that the degree of overheating of the low-pressure refrigerant which is transferred from the internal heat exchanger to the compressor is reduced when refrigeration load is high, an abnormal rise of temperature of the refrigerant compressed by the compressor can be suppressed.

CITATION LIST

Patent Literature

[PTL 1] Japanese Patent Application Laid-Open No. 2009-008369

SUMMARY OF THE INVENTION

Technical Problem

Like the related refrigeration system above-mentioned, in the refrigeration system which is composed of the evaporator, the condenser, the compressor, and the expansion valve, it is possible to increase enthalpy of the liquid-phase refrigerant by performing heat exchange between the low-pressure and low-temperature gas-phase refrigerant and the high-pressure and high temperature liquid-phase refrigerant. Thereby efficiency of the compressor can be improved.
In this case, heat is transferred from the liquid-phase refrigerant to the gas-phase refrigerant by the heat exchanger which performs heat exchange between the gas-phase refrigerant and the liquid-phase refrigerant through the wall face.
Since density of the gas-phase refrigerant is smaller than that of the liquid-phase refrigerant, heat conductivity between the gas-phase refrigerant and the wall face is decreased if the flow velocity of the gas-phase refrigerant is the same as that of liquid-phase refrigerant.
On the other hand, since density of the liquid-phase refrigerant is larger than that of the gas-phase refrigerant, the flow velocity is decreased if the mass flow rate of the gas-phase refrigerant is the same as that of the liquid-phase refrigerant.
Therefore, heat conductivity between the liquid-phase refrigerant and the wall face is decreased.
A contact area between the gas-phase refrigerant and the wall face has to be enlarged in order to increase each heat conductivity. For example, the double tube which is installed in the related refrigeration system has to be elongated or bended, or have a complicated structure which may cause a turbulent flow.
The wall face which is in contact with the liquid-phase refrigerant has to also include a complicated structure so that the turbulent flow occurs even in the liquid-phase refrigerant whose flow rate is small.
In the refrigeration system, however, if pressure loss of the gas-phase refrigerant is increased, the compressor has to further add pressure corresponding to pressure drop.
If the structure of the heat exchanger becomes complicated in order to improve performance of heat exchange, large pressure loss occurs due to the turbulent flow, etc. and efficiency of the refrigeration system is reduced instead.
As mentioned above, in the refrigeration system, there is an issue that if performance of heat exchange between the gas-phase refrigerant and the liquid-phase refrigerant is improved, efficiency of the whole refrigeration system is reduced instead.
An object of the present invention is to provide a heat exchange device and a heat exchange method that resolve the above-described issue that, in the refrigeration system, if performance of heat exchange between the gas-phase refrigerant and the liquid-phase refrigerant is improved, efficiency of the whole refrigeration system is reduced instead.

Solution to the Problem

A heat exchange device of the invention includes, a refrigerant supply means for supplying a first-temperature liquid-phase refrigerant and a second-temperature gas-phase refrigerant in one circulation system, a plurality of heat exchange means which are each configured so as to perform heat exchange between the liquid-phase refrigerant and the gas-phase refrigerant, and a refrigerant circulation means for circulating the gas-phase refrigerant in such a manner that the gas-phase refrigerant flows in parallel in the plurality of heat exchange means, and circulating the liquid-phase refrigerant in such a manner that the liquid-phase flows in series in the plurality of heat exchange means.
A heat exchange method of the present invention includes supplying a first-temperature liquid-phase refrigerant and a second-temperature gas-phase refrigerant by one circulation system, circulating the gas-phase refrigerant in such a manner that the gas-phase refrigerant flows in parallel, circulating the liquid-phase refrigerant in such a manner that the liquid-phase flows in series, and performing heat exchange between the parallelized gas-phase refrigerant and the liquid-phase refrigerant.

Advantageous Effects of the Invention

The heat exchange device and the heat exchange method of the present invention enable to improve performance of heat exchange between a gas-phase refrigerant and a liquid-phase refrigerant and efficiency of a whole refrigeration system.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 a schematic view illustrating a structure of a heat exchange device of a first example embodiment of the present invention;

FIG. 2A a front view illustrating one example of a structure of a heat exchanger installed in the heat exchange device of the first example embodiment of the present invention;

FIG. 2B a side view illustrating one example of a structure of a heat exchanger installed in the heat exchange device of the first example embodiment of the present invention;

FIG. 3A a schematic view illustrating a structure of a heat exchange device of a second example embodiment of the present invention;

FIG. 3B a partial schematic view illustrating a structure of the heat exchange device of the second example embodiment of the present invention;

FIG. 4 a schematic view illustrating another structure of the heat exchange device of the second example embodiment of the present invention;

FIG. 5A a side cross-sectional view illustrating a structure of a heat exchange device of a third example embodiment of the present invention;

FIG. 5B a top view illustrating a structure of the heat exchange device of the third example embodiment of the present invention;

FIG. 6A a side cross-sectional view illustrating another structure of the heat exchange device of the third example embodiment of the present invention;

FIG. 6B a top view illustrating another structure of the heat exchange device of the third example embodiment of the present invention;

FIG. 7 a side cross-sectional view illustrating another structure of the heat exchange device of the third example embodiment of the present invention;

FIG. 8A a side cross-sectional view illustrating further another structure of the heat exchange device of the third example embodiment of the present invention;

FIG. 8B a top view illustrating further another structure of the heat exchange device of the third example embodiment of the present invention;

FIG. 9 a schematic view illustrating a structure of a refrigeration system of a fourth example embodiment of the present invention;

EXAMPLE EMBODIMENT

Referring to the drawings, example embodiments of the present invention are described below.

First Example Embodiment

FIG. 1 is a schematic view illustrating a structure of a heat exchange device 100 of a first example embodiment of the invention.
The heat exchange device 100 of the present example embodiment includes a refrigerant supply part (refrigerant supply means) 110, a plurality of heat exchangers (heat exchange means) 120, and a refrigerant circulation part (refrigerant circulation means) 130.
The refrigerant supply part 110 supplies a first-temperature liquid-phase refrigerant and a second-temperature gas-phase refrigerant in one circulation system.
The heat exchanger 120 is configured so as to perform heat exchange between the liquid-phase refrigerant and the gas-phase refrigerant.
The refrigerant circulation part 130 circulates the gas-phase refrigerant in such a manner that the gas-phase refrigerant flows in parallel in the plurality of heat exchangers 120, and circulates the liquid-phase refrigerant in such a manner that the liquid-phase flows in series in the plurality of heat exchangers 120.
In the heat exchange device 100 of the example embodiment, the liquid-phase refrigerant and the gas-phase refrigerant are supplied in one circulation system.
Since the refrigerants are circulated, the mass flow rate of the gas-phase refrigerant is the same as that of the liquid-phase refrigerant based on the law of conservation of mass.
However, since density of the gas-phase refrigerant is one several hundredth of that of the liquid-phase refrigerant, the volume flow rate of the gas-phase refrigerant is several hundred times larger than that of the liquid-phase refrigerant.
Therefore the flow velocity of the gas-phase refrigerant is larger than that of the liquid-phase refrigerant, and large pressure loss occurs in the gas-phase refrigerant.
On the other hand, since the volume flow rate of the liquid-phase refrigerant is smaller than that of the gas-phase refrigerant, the flow velocity of the liquid-phase refrigerant is small, and therefore heat conductivity thereof is small.
In the heat exchange device 100 of the example embodiment, the gas-phase refrigerant is branched by the refrigerant circulation part 130 so that the gas-phase refrigerant flows in parallel in the plurality of heat exchanger 120.
Since the flow rate of the gas-phase refrigerant per one heat exchanger 120 is decreased when the gas-phase refrigerant is branched in parallel, the flow velocity of the gas-phase refrigerant is decreased in the heat exchanger 120, and the pressure loss is reduced.
Though the flow velocity of the gas-phase refrigerant is decreased, the contact area is increased since the gas-phase refrigerant flows in the plurality of heat exchanger 120. Therefore reduction of heat conductivity of the gas-phase refrigerant can be avoided.
Since the liquid-phase refrigerant flows in series in the plurality of heat exchangers 120, the liquid-phase refrigerant flows in each heat exchanger 120 at the same flow velocity.
Since the flow velocity is not reduced in the structure having the plurality of heat exchangers 120, the heat conductivity of the liquid-phase refrigerant is not reduced.
Though it is supposed that pressure loss is increased if the heat exchangers are connected in series, the flow velocity of the liquid-phase refrigerant is one several hundredth of that of the gas-phase refrigerant.
Such pressure loss above mentioned is very small compared with that of the whole refrigeration system having the heat exchange device 100 and therefore is negligible.
Since heat capacity of the liquid-phase refrigerant is very large compared with that of the gas-phase refrigerant, sufficient temperature difference between the gas-phase refrigerant and the liquid-phase refrigerant can be generated in a heat exchanger which is located at the lower of the flow of the liquid-phase refrigerant in the plurality of heat exchangers 120.
As described above, the heat exchange device 100 of the example embodiment has the structure in which the plurality of heat exchangers 120 are arranged, the gas-phase refrigerant circulates in parallel, and the liquid-phase refrigerant circulates in series.
Such structure makes it possible to reduce pressure loss in the heat exchanger 120 of the gas-refrigerant and to perform heat exchange between the gas-phase refrigerant and the liquid-phase refrigerant without reducing heat exchange ability of the liquid-phase refrigerant.
In the heat exchange device 100 of the example embodiment, performance of heat exchange performance between the gas-phase refrigerant and the liquid-phase refrigerant can be improved and efficiency of the whole refrigeration system can be improved.
A finned tube type heat exchanger can be typically used for the heat exchanger 120.
FIG. 2A and FIG. 2B show an example of the structure of such heat exchanger 120.
FIG. 2A is a front view, and FIG. 2B is a side view.
As shown in the figures, the heat exchanger 120 may have a structure which includes a tube (heat conducting tube) 121 in which a liquid-phase refrigerant R11 flows and a fin (heat conducting plate) 122 which is connected to the outer surface of the tube 121 and in contact with a gas-phase refrigerant R21.
Generally, if a flow velocity of a gas-phase refrigerant is equal to that of a liquid-phase refrigerant, heat conductivity of the gas-phase refrigerant is smaller than that of the liquid-phase refrigerant.
However, since a contact area with the gas-phase refrigerant is increased by arranging the fin 122 so as to touch the gas-phase refrigerant R21, performance of heat exchange can be improved.
If a louver is arranged on the fin 122, it is possible to put a flow of the gas-phase refrigerant into disorder and generate a turbulent flow.
Thereby even though length of a gas-phase flow channel is short and a flow velocity is small, the heat conductivity can be improved.
When the liquid-phase refrigerant flows in flow channels with smaller diameters which are connected in series, the flow velocity thereof is increased and thereby heat conductivity is improved.
Therefore this also improves performance of heat exchange of the heat exchanger 120.
Next, a heat exchange method of the example embodiment is explained below.
In the heat exchange method of the example embodiment, a first temperature liquid-phase refrigerant and a second temperature gas-phase refrigerant are supplied in one circulation system.
The gas-phase refrigerant is circulated in parallel, and the liquid-phase refrigerant is circulated in series.
Then heat exchange between the parallelized gas-phase refrigerant and the liquid-phase refrigerant is performed.
As mentioned above, in the heat exchange method of the example embodiment, the gas-phase refrigerant is circulated in parallel, and the liquid-phase refrigerant is circulated in series.
Such method can make it possible to reduce pressure loss of the gas-phase refrigerant and further perform heat exchange between the two without reducing heat exchange ability of the liquid-phase refrigerant.
As mentioned above, in the heat exchange method of the example embodiment, performance of heat exchange between the gas-phase refrigerant and the liquid-phase refrigerant can be increased and efficiency of the whole refrigeration system can be improved.

Second Example Embodiment

Next a second example embodiment of the invention is explained below.
FIG. 3A and FIG. 3B show a structure of a heat exchange device 200 of the second example embodiment of the invention.
FIG. 3B is a partial view of the heat exchange device 200 as seen from the direction of the arrow A in FIG. 3A.
The heat exchange device 200 of the example embodiment includes a refrigerant supply part (refrigerant supply means) 210, a plurality of heat exchangers (heat exchange means) 220, a first gas-phase tube 231, a second gas-phase tube 232, a liquid-phase tube 241, and a liquid-phase connection tube 242.
The first gas-phase tube 231, the second gas-phase tube 232, and the liquid-phase connection tube 242 are connected to the refrigerant supply part 210, and a gas-phase refrigerant R21 is supplied from the refrigerant supply part 210 to the first gas-phase tube 231, and a liquid-phase refrigerant R11 is supplied from the refrigerant supply part 210 to the liquid-phase connection tube 242.
The first gas-phase tube 231, the second gas-phase tube 232, the liquid-phase tube 241, and the liquid-phase connection tube 242 constitute a refrigerant circulation means.
The heat exchanger 220 includes a gas-phase refrigerant inflow part 221 into which the gas-phase refrigerant flows, a gas-phase refrigerant outlet 222 from which the gas-phase refrigerant flows, a liquid-phase refrigerant inflow part 223 into which the liquid-phase refrigerant flows, and a liquid-phase refrigerant inflow part 224 from which the liquid-phase refrigerant flows.
The first gas-phase tube 231 connects the plurality of gas-phase refrigerant inflow part 221 which the plurality of heat exchangers 220 each include and the refrigerant supply part 210.
The second gas-phase tube 232 connects the plurality of gas-phase refrigerant outlet 222 which the plurality of heat exchangers 220 each include and the refrigerant supply part 210.
The liquid-phase tube 241 connects the liquid-phase refrigerant inflow part 223 which is installed in one heat exchanger of the plurality of heat exchangers 220 and the liquid-phase refrigerant outlet 224 which is installed in another heat exchanger which is adjacent to the one heat exchanger.
The liquid-phase connection tube 242 connects the liquid-phase refrigerant inflow part 223 which is installed in a heat exchanger which is located at one end of the plurality of heat exchangers 220 and the refrigerant supply part 210.
The liquid-phase connection tube 242 connects the liquid-phase refrigerant outlet 224 which is installed in a heat exchanger which is located at the other end of the plurality of heat exchangers 220 and the refrigerant supply part 210.
As described above, the heat exchange device 200 of the example embodiment is configured so as to include a plurality of heat exchangers 220 and perform heat exchange between the gas-phase refrigerant and the liquid-phase refrigerant supplied from the refrigerant supply part 210.
A low-temperature (second temperature) and low-pressure gas-phase refrigerant which has not yet entered a compressor of a refrigeration system can be used as a gas-phase refrigerant, and a high-temperature (first temperature) and high-pressure liquid-phase refrigerant which has not yet entered an expansion valve can be used as a liquid-phase refrigerant.
The heat exchange device 200 of the example embodiment can be applied to the refrigeration system in which the gas-phase refrigerant and the liquid-phase refrigerant are used in one circulation system.
In this case, in the heat exchanger 220, refrigerant fluids having two kinds of different states each pass through separated spaces and heat is transferred from the high-temperature and high-pressure liquid-phase refrigerant to the low-temperature and low-pressure gas-phase refrigerant.
The first gas-phase tube 231 and the second gas-phase tube 232 in which the gas-phase refrigerant flows diverge into a plurality of parts and are connected to a plurality of heat exchangers 220 in parallel.
Thereby the diverged gas-phase refrigerants each pass through the respective heat exchangers 220.
The liquid-phase refrigerant passes through the liquid-phase tube 241 which connects the plurality of heat exchangers 220 in series, and passes through the respective heat exchangers.
Such structure reduces pressure loss of the gas-phase refrigerant in the heat exchanger 220 and enables the two to perform heat exchange without reducing heat exchange ability of the liquid-phase refrigerant.
In the heat exchanger 200 of the example embodiment, it is possible to improve performance of heat exchange between the gas-phase refrigerant and the liquid-phase refrigerant, and improve efficiency of the whole refrigeration system.
The heat exchanger 200 of the example embodiment may have the structure in which the plurality of heat exchangers 220, the first gas-phase tube 231 and the second gas-phase tube 232 are connected each other as shown in FIG. 3A.
The following structure can be made, in which the order in which the plurality of heat exchangers 220 are connected to the first gas-phase tube 231 is the same as the order in which the plurality of heat exchangers 220 are connected to the second gas-phase tube 232, as seen from the side to which the refrigerant supply part 210 is connected.
Not only this, but the structure may be formed, in which the plurality of heat exchangers 220, the first gas-phase tube 231 and the second gas-phase tube 232 are connected each other as shown in FIG. 4. In other words, a heat exchanger 201 can be configured in such a way that the order in which the plurality of heat exchangers 220 are connected to the first gas-phase tube 231 is opposite to the order in which the plurality of heat exchanger 220 are connected to the second gas-phase tube 232 as seen from the side to which the refrigerant supply part 210 is connected.
Specifically, a heat exchanger 220A, in the plurality of exchangers 220, arranged at the side near the outflow side of the refrigerant supply part 210 of the first gas-phase tube 231 is arranged at the side far from the inflow side of the refrigerant supply part 210 of the second gas-phase tube 232. The plurality of heat exchangers 220 may be also arranged sequentially.
In a circulation system in which a pump, etc. forces a fluid to flow, pressure of the fluid is generally larger on the upstream side (upper side of flow), and therefore the fluid is easy to flow on the upstream side.
Whereas, generally, a fluid which flows in a pipe is easy to flow on the downstream side (lower side of flow) in which an outlet is located since the fluid is easily discharged.
With the structure of the heat exchange device 201 as shown in FIG. 4, the heat exchanger 220A which is connected to the upstream side (upper side of flow) of the first gas-phase tube 231 is connected to the side far from the outlet of the second gas-phase tube 232 (upper side of flow). In the heat exchanger 220A, therefore, a gas-phase refrigerant R21 is easy to flow into the heat exchanger 220A, but is hard to flow out therefrom.
On the other hand, the heat exchanger 220B which is connected to the downstream side (lower side of flow) of the first gas-phase tube 231 is connected to the side near the outlet of the second gas-phase tube 232 (lower side of flow).
In the heat exchanger 220B, therefore, a gas-phase refrigerant R21 is hard to flow into the heat exchanger 220B, but is easy to flow out therefrom.
As described above, in the structure of the heat exchange device 201 as shown in FIG. 4, the degree of ease of flow of the gas-phase refrigerant R21 in each heat exchanger 220 can be equalized.
As a result, the gas-phase refrigerant equally flows in each heat exchanger 220. Accordingly, heat imbalance is reduced, and performance of heat exchange can be improved.
A heat exchange method of the example embodiment is explained below.
In the heat exchange method of the example embodiment, the first temperature liquid-phase refrigerant and the second temperature gas-phase refrigerant are supplied in one circulation system.
The gas-phase refrigerant is circulated in parallel, and the liquid-phase refrigerant is circulated in series.
Heat exchange between the parallelized gas-phase refrigerant and the liquid-phase refrigerant is performed.
In this case, the order of the parallelized gas-phase refrigerant at the time of heat exchange with the liquid-phase refrigerant may be the same as the order of the parallelized gas-phase refrigerant which has performed the heat exchange and circulates.
Alternatively, the order of the parallelized gas-phase refrigerant at the time of heat exchange with the liquid-phase refrigerant may be opposite to the order of the parallelized gas-phase refrigerant which has performed the heat exchange and circulates.
As explained above, in the heat exchange devices 200 and 201 and the heat exchange method of the present example embodiment, performance of heat exchange between the gas-phase refrigerant and the liquid-phase refrigerant can be improved, and efficiency of the whole refrigeration system can be improved.

Third Example Embodiment

Next, a third example embodiment of the invention is explained below.
A heat exchange device of the example embodiment includes a refrigerant supply part (refrigerant supply means), a plurality of heat exchangers (heat exchange means), and a refrigerant circulation part (refrigerant circulation means).
The heat exchange device of the example embodiment differs from the heat exchange device 100 of the first example embodiment in structures of the heat exchanger and the refrigerant circulation part.
FIG. 5A and FIG. 5B show a structure of a heat exchange device 300 of the example embodiment.
FIG. 5A is side cross-sectional view and FIG. 5B is a top view.
Each heat exchanger 320 installed in the heat exchange device 300 includes a gas-phase refrigerant passing face 321 on which the gas-phase refrigerant R21 passes, a liquid-phase refrigerant inflow part 322 which a liquid-phase refrigerant flows into, and a liquid-phase refrigerant outlet 323 which a liquid-phase refrigerant flow from.
The refrigerant circulation part includes a gas-phase tube 330, a plurality of partitions 350, a liquid-phase tube 341, and liquid-phase connection tube 342.
The gas-phase tube 330 contains the plurality of heat exchangers 320, and the gas-phase refrigerant R21 flows inside the gas-phase tube 330.
The plurality of partitions 350 is each located at the side which the gas-phase refrigerant R21 on the gas-phase refrigerant passing face 321 which the plurality of heat exchangers 320 each include flows in.
The liquid-phase tube 341 connects the liquid-phase refrigerant inflow part 322 which is installed in one heat exchanger of the plurality of heat exchangers 320 and the liquid-phase refrigerant outlet 323 which is installed in another heat exchanger which is adjacent to the one heat exchanger.
The liquid-phase connection tube 342 connects the liquid-phase refrigerant inflow part 322 which is installed in a heat exchanger 320A which is located at one end of the plurality of heat exchangers 320 and the refrigerant supply part 310, and connects the liquid-phase refrigerant outlet 323 which is installed in a heat exchanger 320B which is located at the other end of the plurality of heat exchangers 320 and the refrigerant supply part 310.
As shown in FIG. 5A and FIG. 5B, the heat exchange device 300 of the example embodiment includes the plurality of heat exchangers 320 which is located in the gas-phase tube 330 which is a pipe having an inside diameter which is capable of containing a heat exchanger therein.
Further, the heat exchange device 300 of the present example embodiment is configured in such a way that the gas-phase refrigerant R21 flows in each of heat exchangers 320 in parallel by the plurality of partitions 350, and the liquid-phase refrigerant flows in the plurality of exchangers 320 in series through the liquid-phase tube 341.
The finned tube type heat exchanger can be typically used for the heat exchanger 320.
A shape of cross section of the gas-phase tube 330 may be a circle or a polygon.
The partitions 350 arranged between heat exchangers 320 separate an area of the gas-phase refrigerant which has not yet passed through the heat exchangers 320 from an area of the gas-phase refrigerant which has already passed through the heat exchangers 320.
As shown in FIG. 5A, if the partitions 350 are inclined with respect to a flowing direction of the gas-phase refrigerant R21, the gas-phase refrigerant R21 can pass through each of heat exchangers 320.
In the heat exchange device 300 of the example embodiment having the structure above described, performance of heat exchange between the gas-phase refrigerant and the liquid-phase refrigerant is improved, and efficiency of the whole refrigeration system is also improved.
Further since the number of pipes for the gas-phase refrigerant which is circulated through the plurality of heat exchangers 320 is reduced, the heat exchange device 300 can be downsized.
As shown in FIG. 5A, the heat exchangers 320 may be arranged so that the normal line of the gas-phase refrigerant passing face 321 is approximately parallel to a flowing direction of the gas-phase refrigerant R21 in the gas-phase tube 330.
Alternatively, like a heat exchange device 301 shown in FIG. 6A and FIG. 6B, the angle made by the normal line of the gas-phase refrigerant passing face 321 and the flowing direction of the gas-phase refrigerant R21 in the gas-phase tube 330 may be more than 90 degrees and less than 180 degrees. This angle is an angle made by a normal line facing the side in which the gas-phase refrigerant R21 flows of the normal lines of the gas-phase refrigerant passing face 321 and the flowing direction of the gas-phase refrigerant R21.
The heat exchangers 320 may be inclined with respect to the flowing direction of the gas-phase refrigerant R21 in the gas-phase tube 330.
In such structure, since the installation space for the heat exchangers in the direction of the inside diameter of the gas-phase tube 330 can be reduced, a cross-sectional area of the gas-phase tube 330 housing the heat exchangers can be reduced.
In this case, the angle made by the normal line of the gas-phase refrigerant passing face 321 and a normal line of the partition 350 may be approximately a right angle.
Thereby loss of the flowing gas-phase refrigerant is reduced and pressure loss of the gas-phase refrigerant can be reduced.
As shown in FIG. 7, a normal line of a partition 350C of the plurality of the partitions 350 may be approximately parallel to the flowing direction of the gas-phase refrigerant R21 in the gas-phase tube 330.
The partition 350C is located on the side to which the gas-phase refrigerant R21 flows of the heat exchanger 320C which is located at the end part of the side to which the gas-phase refrigerant R21 flows.
A lot of gas-phase refrigerants are easy to flow in the heat exchanger 320C which is located on the most upstream side (upper side of flow) in the flowing direction of the gas-phase refrigerant R21, since the refrigerant initially flows therein.
If a gas-phase refrigerant flows into one heat exchanger in a concentrated manner, imbalance of heat which is a target of heat exchange occurs and performance of heat exchange is reduced.
If the partition 350C is arranged above the heat exchanger 320C located on the most upstream side, as shown in FIG. 7, it is possible to prevent the gas-phase refrigerant from flow into the heat exchanger 320C in a concentrated manner.
Therefore imbalance of heat in the plurality of heat exchanger 320 is avoided and performance of cooling is improved.
Like a heat exchange device 302 shown in FIG. 8A and FIG. 8B, the angle made by the normal lines of the gas-phase refrigerant passing face 321 and the flowing direction of the gas-phase refrigerant R21 in the gas-phase tube 330 can be approximately a right angle.
In this case, the angle made by the normal line of the partition 350 and the flowing direction of the gas-phase refrigerant R21 in the gas-phase tube 330 may be approximately a right angle.
If the above-described structure is made, a cross-sectional area of the gas-phase tube 330 containing the plurality of heat exchanger 320 can be further reduced.

Fourth Example Embodiment

A fourth example embodiment of the invention is explained below. FIG. 9 is a schematic view illustrating a structure of a refrigeration system 1000 of the example embodiment.
The refrigeration system 1000 includes a heat exchange device 1100, a heat receiving part (heat receiving means) 1200, a compressor (compressing means) 1300, a heat radiating part (heat radiating means) 1400, and an expansion valve (expanding means) 1500.
Any one of the heat exchange devices 100, 200, 201, 300, 301, and 302 which are explained in the first example embodiment to the third example embodiment can be used as the heat exchange device 1100.
Further, the heat exchange device 1100 is configured in such a way that a refrigerant supply part included in the heat exchange device 1100 is connected to the heat receiving part 1200, the compressor 1300, the heat radiating part 1400, and the expansion valve 1500.
Thereby, in the refrigeration system 1000 of the example embodiment, a gas-phase refrigerant and a liquid-phase refrigerant are supplied to the heat exchange device 1100 in one circulation system through the refrigerant supply part.
The heat receiving part 1200 produces a gas-phase refrigerant by evaporating a liquid refrigerant by receiving heat.
The compressor 1300 produces a high-pressure gas-phase refrigerant by compressing the gas-phase refrigerant.
The heat radiating part 1400 produces a liquid-phase refrigerant by condensing the high-pressure gas-phase refrigerant by radiating heat.
The expansion valve 1500 produces a liquid refrigerant whose pressure is lowered by expanding the liquid-phase refrigerant and return the liquid refrigerant to the heat receiving part 1200.
Thereby the circulation system for a refrigerant is formed.
The gas-phase refrigerant supplied to the heat exchange device 1100 is the low-temperature (second temperature) and low-pressure gas-phase refrigerant which has not yet entered the compressor 1300.
The liquid-phase refrigerant supplied to the heat exchange device 1100 is the high-temperature (first temperature) and high-pressure liquid-phase refrigerant which has not yet entered the expansion valve 1500.
As explained in the above example embodiments, the heat exchange device 1100 has the structure in which a plurality of heat exchangers is installed, a gas-phase refrigerant is circulated in parallel each other, and a liquid-phase refrigerant is circulated in series.
Due to such structure, pressure loss of the gas-phase refrigerant in the heat exchanger can be reduced, and heat exchange between the two can be performed without reducing ability of heat exchange of the liquid-phase refrigerant.
The heat exchange device 1100 can improve performance of heat exchange between the gas-phase refrigerant and the liquid-phase refrigerant without increasing pressure loss of the gas-phase refrigerant.
Therefore even though the structure in which performance of heat exchange is improved is made, there is no need to increase workload of the compressor 1300.
As mentioned above, according to the refrigeration system 1000 of the present example embodiment efficiency of the whole refrigeration system can be improved.
A part or all of the example embodiments above mentioned may be described as following supplementary notes, but is not limited to the following.
(Supplementary note 1) A heat exchange device includes a refrigerant supply means for supplying a first-temperature liquid-phase refrigerant and a second-temperature gas-phase refrigerant in one circulation system, a plurality of heat exchange means which are each configured so as to perform heat exchange between the liquid-phase refrigerant and the gas-phase refrigerant, and a refrigerant circulation means for circulating the gas-phase refrigerant in such a manner that the gas-phase refrigerant flows in parallel in the plurality of heat exchange means, and circulating the liquid-phase refrigerant in such a manner that the liquid-phase refrigerant flows in series in the plurality of heat exchange means.
(Supplementary note 2) The heat exchange device described in the supplementary note 1 in which the heat exchange means includes a heat conducting tube in which the liquid-phase refrigerant flows, and a heat conducting plate which is connected to an outer surface of the heat conducting tube and touches the gas-phase refrigerant.
(Supplementary note 3) The heat exchange device described in the supplementary note 1 or the supplementary note 2, in which the heat exchange means includes a gas-phase refrigerant inflow part into which the gas-phase refrigerant flows, a gas-phase refrigerant outlet from which the gas-phase refrigerant flows, a liquid-phase refrigerant inflow part into which the liquid-phase refrigerant flows, and a liquid-phase refrigerant outlet from which the liquid-phase refrigerant flows, and the refrigerant circulation means includes a first gas-phase tube which connects the refrigerant supply means with the plurality of gas-phase refrigerant inflow parts which the plurality of heat exchange means each include, a second gas-phase tube which connects the refrigerant supply means with the plurality of gas-phase refrigerant outlets which the plurality of heat exchange means each include, a liquid-phase tube which connects the liquid-phase refrigerant inflow part which is installed in one heat exchange means of the plurality of heat exchange means with the liquid-phase refrigerant outlet which is installed in another heat exchange means which is adjacent to the one heat exchange means, and a liquid-phase connection tube which connects the refrigerant supply means with the liquid-phase refrigerant inflow part which is installed in a heat exchange means which is located at one end of the plurality of heat exchange means and connects the refrigerant supply means with the liquid-phase refrigerant outlet which is installed in a heat exchange means which is located at the other end of the plurality of heat exchange means.
(Supplementary note 4) The heat exchange device described in the supplementary note 3, in which the plurality of heat exchange means are connected to the first gas-phase tube and the second gas-phase tube so that the order in which the plurality of heat exchange means are connected to the first gas-phase tube is the same as the order in which the plurality of heat exchange means are connected to the second gas-phase tube as seen from the side to which the refrigerant supply means is connected.
(Supplementary note 5) The heat exchange device described in the supplementary note 3, in which the plurality of heat exchange means are connected to the first gas-phase tube and the second gas-phase tube so that the order in which the plurality of heat exchange means are connected to the first gas-phase tube is opposite to the order in which the plurality of heat exchange means are connected to the second gas-phase tube as seen from the side to which the refrigerant supply means is connected.
(Supplementary note 6) The heat exchange device described in the supplementary note 1 or the supplementary note 2, in which the heat exchange means includes a gas-phase refrigerant passing face which the gas-phase refrigerant passes through, the liquid-phase refrigerant inflow part into which the liquid-phase refrigerant flows and the liquid-phase refrigerant outlet from which the liquid-phase refrigerant flows, and the refrigerant circulation means includes a gas-phase tube which contains the plurality of heat exchange means and in which the gas-phase refrigerant flows, a plurality of partitions which are each located on the side in which the gas-phase refrigerant flows of the gas-phase refrigerant passing face which the plurality of heat exchange means each include, a liquid-phase tube which connects the liquid-phase refrigerant inflow part which is installed in one heat exchange means of the plurality of heat exchange means with the liquid-phase refrigerant outlet which is installed in another heat exchange means which is adjacent to the one heat exchange means, and a liquid-phase connection tube which connects the refrigerant supply means with the liquid-phase refrigerant inflow part which is installed in a heat exchange means which is located at one end of the plurality of heat exchange means and connects the refrigerant supply means with the liquid-phase refrigerant outlet which is installed in a heat exchange means which is located at the other end of the plurality of heat exchange means.
(Supplementary note 7) The heat exchange device described in the supplementary note 6, in which a normal line of the gas-phase refrigerant passing face is approximately parallel to a flowing direction of the gas-phase refrigerant in the gas-phase tube.
(Supplementary note 8) The heat exchange device described in the supplementary note 6, in which the angle made by a normal line of the gas-phase refrigerant passing face and a flowing direction of the gas-phase refrigerant in the gas-phase tube is more than 90 degrees and less than 180 degrees, and the angle which is made by the normal line of the gas-phase refrigerant passing face and a normal line of the partition is approximately a right angle.
(Supplementary note 9) The heat exchange device described in the supplementary note 8, in which, in the plurality of partitions, the normal line of the partition which is located on the side into which the gas-phase refrigerant flows of the heat exchange means which is located on the end part of the side into which the gas-phase refrigerant flows is approximately parallel to the flowing direction of the gas-phase refrigerant in the gas-phase tube.
(Supplementary note 10) The heat exchange device described in the supplementary note 6, in which the angle made by a normal line of the gas-phase refrigerant passing face and a flowing direction of the gas-phase refrigerant in the gas-phase tube is approximately a right angle, and the angle made by a normal line of the partition and a flowing direction of the gas-phase refrigerant in the gas-phase tube is approximately a right angle.
(Supplementary note 11) A refrigeration system includes the heat exchange device described in any one of the supplementary 1 to the supplementary 10, a heat receiving means for producing a gas-phase refrigerant by vaporizing a liquid refrigerant by heat reception, a compressing means for producing a high-pressure liquid refrigerant by compressing the gas-phase refrigerant, a heat radiating means for producing the liquid-phase refrigerant by condensing the high-pressure gas-phase refrigerant by heat radiation, and an expanding means for generating the liquid refrigerant whose pressure is lowered by expanding the liquid-phase refrigerant.
(Supplementary note 12) A heat exchange method includes supplying a first-temperature liquid-phase refrigerant and a second-temperature gas-phase refrigerant in one circulation system, circulating the gas-phase refrigerant in such a manner that the gas-phase refrigerant flows in parallel, circulating the liquid-phase refrigerant in such a manner that the liquid-phase flows in series, and performing heat exchange between the parallelized gas-phase refrigerant and the liquid-phase refrigerant.
(Supplementary note 13) A heat exchange method described in the supplementary note 12, in which the order of the parallelized gas-phase refrigerant which performs the heat exchange with the liquid-phase refrigerant is the same as the order of the parallelized liquid-phase refrigerant which is circulated after the heat exchange.
(Supplementary note 14) A heat exchange method described in the supplementary note 12, in which the order of the parallelized gas-phase refrigerant which performs the heat exchange with the liquid-phase refrigerant is opposite to the order of the parallelized liquid-phase refrigerant which is circulated after the heat exchange.
While the invention has been particularly shown and described with reference to exemplary embodiments thereof, the invention is not limited to these embodiments.
It will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope of the present invention as defined by the claims.
This application is based upon and claims the benefit of priority from Japanese Patent Application No. 2016-070218, filed on Mar. 31, 2016, the disclosure of which is incorporated herein in its entirety by reference.

REFERENCE SIGNS LIST

100, 200, 201, 300, 301, 302, 1100 heat exchange device
110, 210, 310 refrigerant supply part
120, 220, 320 heat exchanger
121 tube
122 fin
130 refrigerant circulation part
221 gas-phase refrigerant inflow part
222 gas-phase refrigerant outlet
223, 322 liquid-phase refrigerant inflow part
224, 323 liquid-phase refrigerant outlet
231 first gas-phase tube
232 second gas-phase tube
241, 341 liquid-phase tube
242, 342 liquid-phase connection tube
321 gas-phase refrigerant passing face
330 gas-phase tube
350 partition
1000 refrigeration system
1200 heat receiving part
1300 compressor
1400 heat radiating part
1500 expansion valve

Claims

1. A heat exchange device, comprising:

a refrigerant supply device that supplies a first-temperature liquid-phase refrigerant and a second-temperature gas-phase refrigerant in one circulation system;

a plurality of heat exchangers which are each configured so as to perform heat exchange between the liquid-phase refrigerant and the gas-phase refrigerant; and

a refrigerant circulator that circulates the gas-phase refrigerant in such a manner that the gas-phase refrigerant flows in parallel in the plurality of heat exchangers, and circulates the liquid-phase refrigerant in such a manner that the liquid-phase refrigerant flows in series in the plurality of heat exchangers.

2. The heat exchange device of claim 1, wherein

the heat exchanger comprises:

a heat conducting tube in which the liquid-phase refrigerant flows; and

a heat conducting plate that is connected to an outer surface of the heat conducting tube and in contact with the gas-phase refrigerant.

3. The heat exchange device of claim 1, wherein

the heat exchanger comprises:

a gas-phase refrigerant inflow part into which the gas-phase refrigerant flows;

a gas-phase refrigerant outlet from which the gas-phase refrigerant flows;

a liquid-phase refrigerant inflow part into which the liquid-phase refrigerant flows; and

a liquid-phase refrigerant outlet from which the liquid-phase refrigerant flows, and

the refrigerant circulator comprises:

a first gas-phase tube which connects the refrigerant supply device with a plurality of the gas-phase refrigerant inflow parts which the plurality of heat exchangers each include;

a second gas-phase tube which connects the refrigerant supply device with a plurality of the gas-phase refrigerant outlets which the plurality of heat exchangers each include;

a liquid-phase tube which connects the liquid-phase refrigerant inflow part which is installed in one heat exchanger of the plurality of heat exchangers with the liquid-phase refrigerant outlet which is installed in another heat exchanger which is adjacent to the one heat exchanger; and

a liquid-phase connection tube which connects the refrigerant supply device with the liquid-phase refrigerant inflow part which is installed in a heat exchanger which is located at one end of the plurality of heat exchangers and connects the refrigerant supply device with the liquid-phase refrigerant outlet which is installed in a heat exchanger which is located at another end of the plurality of heat exchangers.

4. The heat exchange device of claim 3, wherein

the plurality of heat exchangers are connected to the first gas-phase tube and the second gas-phase tube in such a way that order in which the plurality of heat exchangers are connected to the first gas-phase tube is same as order in which the plurality of heat exchangers are connected to the second gas-phase tube as seen from a side to which the refrigerant supply device is connected.

5. The heat exchange device of claim 3, wherein

the plurality of heat exchangers are connected to the first gas-phase tube and the second gas-phase tube in such a way that order in which the plurality of heat exchangers are connected to the first gas-phase tube is opposite to order in which the plurality of heat exchangers are connected to the second gas-phase tube as seen from a side to which the refrigerant supply device is connected.

6. The heat exchange device of claim 1, wherein

the heat exchanger comprises:

a gas-phase refrigerant passing face that the gas-phase refrigerant passes through;

the refrigerant circulator comprises:

a gas-phase tube in which the gas-phase refrigerant flows, the gas-phase tube containing the plurality of heat exchangers;

a plurality of partitions which are each located on a side into which the gas-phase refrigerant flows of the gas-phase refrigerant passing face which the plurality of heat exchangers each include;

a liquid-phase tube that connects the liquid-phase refrigerant inflow part that is installed in one heat exchanger of the plurality of heat exchangers with the liquid-phase refrigerant outlet that is installed in another heat exchanger that is adjacent to the one heat exchanger; and

a liquid-phase connection tube that connects the refrigerant supply device with the liquid-phase refrigerant inflow part that is installed in a heat exchanger that is located at one end of the plurality of heat exchangers, and connects the refrigerant supply device with the liquid-phase refrigerant outlet that is installed in a heat exchanger that is located at another end of the plurality of heat exchangers.

7. The heat exchange device of claim 6, wherein

a normal line of the gas-phase refrigerant passing face is approximately parallel to a flowing direction of the gas-phase refrigerant in the gas-phase tube.

8. The heat exchange device of claim 6, wherein

an angle made by a normal line of the gas-phase refrigerant passing face and a flowing direction of the gas-phase refrigerant in the gas-phase tube is more than 90 degrees and less than 180 degrees, and an angle made by the normal line of the gas-phase refrigerant passing face and a normal line of the partition is approximately a right angle.

9. The heat exchange device of claim 8, wherein,

of the plurality of partitions, a normal line of the partition that is located on a side of the heat exchange device into which the gas-phase refrigerant flows and at an end part of the side into which the gas-phase refrigerant flows is approximately parallel to the flowing direction of the gas-phase refrigerant in the gas-phase tube.

10. The heat exchange device of claim 6, wherein

an angle made by a normal line of the gas-phase refrigerant passing face and a flowing direction of the gas-phase refrigerant in the gas-phase tube is approximately a right angle, and an angle made by a normal line of the partition and the flowing direction of the gas-phase refrigerant in the gas-phase tube is approximately a right angle.

11. A refrigeration system, comprising:

the heat exchange device described in claim 1;

a heat receiver that produces a gas-phase refrigerant by vaporizing a liquid refrigerant by heat reception;

a compressor that produces a high-pressure gas-phase refrigerant by compressing the gas-phase refrigerant;

a heat radiator that produces the liquid-phase refrigerant by condensing the high-pressure gas-phase refrigerant by heat radiation; and

an expander that produces the liquid refrigerant whose pressure is lowered by expanding the liquid-phase refrigerant.

12. A heat exchange method, comprising:

supplying a first-temperature liquid-phase refrigerant and a second-temperature gas-phase refrigerant in one circulation system;

circulating the gas-phase refrigerant in such a manner that the gas-phase refrigerant flows in parallel;

circulating the liquid-phase refrigerant in such a manner that the liquid-phase flows in series; and

causing heat exchange between parallelized gas-phase refrigerant and the liquid-phase refrigerant.

13. The heat exchange method of claim 12, wherein

order of the parallelized gas-phase refrigerant that performs the heat exchange with the liquid-phase refrigerant is same as order of the parallelized gas-phase refrigerant that is circulated after the heat exchange.

14. The heat exchange method of claim 12, wherein

order of the parallelized gas-phase refrigerant that performs the heat exchange with the liquid-phase refrigerant is opposite to order of the parallelized gas-phase refrigerant of circulation after the heat exchange.