Laminated heat exchanger

Abstract

To reduce a freezing risk of high temperature side fluid and suppress deterioration in durability in a laminated heat exchanger.SOLUTION: A laminated heat exchanger 10 includes a laminated body 15 having a fluid layer 11 including a high temperature flow passage 12a to which first fluid is introduced and a low temperature flow passage 13a to which second fluid is introduced, and an intermediate medium layer 21 including a middle temperature flow passage 21a to which an intermediate medium is introduced. The middle temperature flow passage 21a includes a heating part 21b for causing heat exchange between the intermediate medium and the first fluid flowing through the high temperature flow passage 12a, and a cooling part 21c for causing heat exchange between the intermediate medium after flowing through the heating part 21b and the second fluid flowing through the low temperature flow passage 13a. A return flow passage returns the intermediate medium flowing out from the middle temperature flow passage 21a to the middle temperature flow passage 21a.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a stacked heat exchanger. [Background technology]

[0002] In recent years, deregulation of the energy industry in Japan has progressed, and there has been a shift from coal and oil, which have a large carbon dioxide (CO2) emission coefficient, to LNG, a clean energy with a small emission coefficient. In addition, in recent years, it has been considered to use hydrogen as a fuel for power generation and automobiles, etc., in consideration of the environment, and the demand for hydrogen is increasing. Incidentally, a stacked type heat exchanger is conventionally known, which includes a first fluid layer having a flow path through which a first fluid flows, and a second fluid layer having a flow path through which a second fluid, which has a temperature different from that of the fluid layer, flows, and the first fluid layer and the second fluid layer are stacked. For example, Patent Documents 1 and 2 below disclose a stacked type heat exchanger for heating a very low temperature liquefied gas (second fluid) with a first fluid (high temperature fluid) such as water. When the second fluid (very low temperature liquefied gas) is heated with a first fluid such as water, a problem of the first fluid freezing may occur. In view of this problem, in the heat exchanger disclosed in Patent Document 1, an adjustment layer is provided between a first fluid layer in which a first fluid flows and a second fluid layer in which a second fluid flows, and this adjustment layer is configured to have parts with different heat transfer performances. Patent Document 1 explains that the adjustment layer suppresses heat transfer at a place where freezing is likely to occur, thereby suppressing freezing of the first fluid. On the other hand, the heat exchanger disclosed in Patent Document 2 is provided with a connection channel that connects multiple flow paths through which a first fluid such as water flows. Patent Document 2 explains that even if some of the flow paths are blocked by freezing of the first fluid, the first fluid can be made to flow around through the connection channel, thereby preventing the expansion of the frozen area. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 6118008 [Patent Document 2] JP 2019-178807 A Summary of the Invention [Problem to be solved by the invention]

[0004] Patent Documents 1 and 2 disclose techniques for dealing with freezing of the first fluid (high-temperature fluid), but there is still room for improvement in these techniques. For example, when extremely low-temperature liquefied gas (second fluid) is heated by water (first fluid, high-temperature fluid), the temperature difference between the two fluids is large, which may cause large thermal stress in the stacked heat exchanger. However, the techniques disclosed in Patent Documents 1 and 2 do not address this thermal stress. As a result, the problem of reduced durability due to excessive thermal stress remains.

[0005] Therefore, the present invention has been made in consideration of the above-mentioned conventional technology, and its object is to reduce the risk of freezing of the high-temperature side fluid in a stacked heat exchanger while suppressing a decrease in durability. [Means for solving the problem]

[0006] In order to achieve the above object, the laminated heat exchanger according to the present invention comprises a laminate including a fluid layer having a high-temperature flow path into which a first fluid is introduced and a low-temperature flow path into which a second fluid having a lower temperature than the first fluid is introduced, and an intermediate medium layer laminated on the fluid layer and having a medium-temperature flow path into which an intermediate medium having a lower temperature than the first fluid and a higher temperature than the second fluid is introduced. The medium-temperature flow path of the intermediate medium layer includes a heating section that causes heat exchange between the intermediate medium flowing through the medium-temperature flow path and the first fluid flowing through the high-temperature flow path, and a cooling section that causes heat exchange between the intermediate medium before or after flowing through the heating section and the second fluid flowing through the low-temperature flow path. The laminated heat exchanger further includes a return flow path that returns the intermediate medium flowing out of the medium-temperature flow path to the medium-temperature flow path.

[0007] In the stacked heat exchanger according to the present invention, the intermediate medium flowing through the medium temperature flow path is heat exchanged with the first fluid in the heating section so as to be heated by the first fluid, and is heat exchanged with the second fluid in the cooling section so as to be cooled by the second fluid. Therefore, the first fluid can be cooled by the intermediate medium before being discharged, and the second fluid can also be heated by the intermediate medium before being discharged. Therefore, the stacked heat exchanger can be used as a heater for heating the second fluid, and as a cooler for cooling the first fluid.

[0008] The intermediate medium is cooled when the second fluid is heated, but since this intermediate medium is heated in the heating section in the laminate, it is not necessary to provide a heater for heating the intermediate medium. In addition, the intermediate medium is heated when the first fluid is cooled, but since this intermediate medium is cooled in the cooling section in the laminate, it is not necessary to provide a cooler for cooling the intermediate medium. Therefore, since it is not necessary to provide a heater or a cooler separately from the laminate, the laminated heat exchanger can be made compact. The intermediate medium may flow directly from the cooling section to the heating section, or may flow from the cooling section to the heating section through a return path. In addition, the intermediate medium may flow directly from the heating section to the cooling section, or may flow from the heating section to the cooling section through a return path.

[0009] Moreover, since the medium temperature flow path has a heating section and a cooling section separately, the timing when the intermediate medium is heated by the first fluid and the timing when the intermediate medium is cooled by the second fluid are shifted in the stack. Therefore, even if heat exchange is performed between the first fluid and the second fluid via the intermediate medium, the first fluid can be cooled and the second fluid can be heated efficiently. In addition, since the first fluid (high temperature side fluid) does not directly exchange heat with the second fluid, the risk of freezing of the first fluid (high temperature side fluid) can be reduced and the thermal stress generated in the stack can be reduced. Therefore, it is also possible to suppress a decrease in durability of the stack caused by thermal stress.

[0010] The heating section and the cooling section may be disposed at positions not overlapping with each other in a stacking direction of the fluid layers and the intermediate medium layers in the stack.

[0011] In this embodiment, the intermediate medium flowing through the medium temperature flow passage can be prevented from being heated by the first fluid and cooled by the second fluid at the same time. Therefore, the cooling of the first fluid by the intermediate medium and the heating of the second fluid by the intermediate medium can be separated. Therefore, the first fluid can be effectively cooled and the second fluid can be effectively heated.

[0012] The fluid layer may have a high temperature layer having the high temperature flow path but not the low temperature flow path, and a low temperature layer having the low temperature flow path but not the high temperature flow path. In this embodiment, direct heat exchange between the first fluid flowing through the high temperature flow path and the second fluid flowing through the low temperature flow path can be suppressed.

[0013] The high-temperature flow path and the low-temperature flow path may be located in the same layer. In this case, a heat transfer suppressing section for suppressing heat exchange between the first fluid and the second fluid may be provided between the high-temperature section in which the high-temperature flow path is provided and the low-temperature section in which the low-temperature flow path is provided. In this embodiment, it is possible to suppress direct heat exchange between the first fluid flowing through the high-temperature flow path and the second fluid flowing through the low-temperature flow path while preventing the stack from becoming large in the stacking direction.

[0014] The return path may be provided with a pump that causes the intermediate medium to flow from the heating section to the cooling section in the medium temperature path and then out of the cooling section into the return path, and a cold energy utilization section that receives the cold energy of the intermediate medium.

[0015] In this embodiment, the intermediate medium cooled by the second fluid flows through the return passage. The return passage is provided with a cold energy utilization unit that receives the cold energy of the cooled intermediate medium, so that the cold energy of the intermediate medium can be utilized outside.

[0016] The return path may be provided with a pump that causes the intermediate medium to flow in the medium temperature path from the cooling section to the heating section and then out of the heating section into the return path.

[0017] In this embodiment, even if the intermediate medium is cooled by the second fluid in the cooling section of the medium temperature flow path, it is subsequently heated in the heating section before flowing into the return flow path. Therefore, the pump provided in the return flow path can be prevented from being exposed to low temperatures, and low temperature measures for the pump are not required.

[0018] The laminated heat exchanger may include a second stack having a second fluid layer having a second high-temperature flow path into which a first fluid is introduced and a second low-temperature flow path into which a second fluid having a lower temperature than the first fluid is introduced, and a second intermediate medium layer stacked on the second fluid layer and having a second intermediate medium flow path into which an intermediate medium having a temperature between the first fluid and the second fluid is introduced. The second intermediate medium flow path of the second intermediate medium layer includes a second heating section that causes heat exchange between the intermediate medium and the first fluid flowing through the second high-temperature flow path, and a second cooling section that causes heat exchange between the intermediate medium after flowing through the second heating section and the second fluid flowing through the second low-temperature flow path. The laminated heat exchanger may further include a second return flow path that returns the intermediate medium flowing out of the second cooling section of the second intermediate temperature flow path to the second heating section of the second intermediate temperature flow path. The second return flow path may be provided with a cold energy utilization section that receives cold energy from the intermediate medium.

[0019] In this embodiment, the intermediate medium cooled by the second fluid in the second cooling section of the second medium temperature flow path flows through the second return path. The second return path is provided with a cold energy utilization section that receives the cold energy of the cooled intermediate medium, making it possible to utilize the cold energy of the intermediate medium outside. Meanwhile, in the laminate, the intermediate medium is cooled by the second fluid in the cooling section of the medium temperature flow path, but this medium temperature medium is then heated in the heating section before flowing into the return path. Therefore, the pump provided in the return path can be prevented from being exposed to low temperatures, making low temperature measures for the pump unnecessary. Effect of the Invention

[0020] As described above, according to the present invention, in a stacked heat exchanger, the risk of freezing of the high-temperature side fluid can be reduced and a decrease in durability can be suppressed. [Brief description of the drawings]

[0021] [Figure 1] FIG. 1(a) is a schematic diagram for explaining the configuration of the laminate of the stack-type heat exchanger of the first embodiment, and FIG. 1(b) is a schematic cross-sectional view of a portion of the laminate of the stack-type heat exchanger of the first embodiment. [Diagram 2] FIG. 2 is a schematic diagram showing a fluid layer, an intermediate medium layer, and a return path of the laminate; [Diagram 3] FIG. 4 is a diagram for explaining an example of temperature changes of a first fluid, a second fluid, and an intermediate medium in the laminate. [Figure 4] FIG. 4 is a schematic diagram for explaining the configuration of a stack of a stack-type heat exchanger according to a modified example of the first embodiment. [Diagram 5] FIG. 4 is a schematic diagram for explaining the configuration of a stack of a stack-type heat exchanger according to a modified example of the first embodiment. [Figure 6] FIG. 4 is a schematic diagram for explaining the configuration of a stack of a stack-type heat exchanger according to a modified example of the first embodiment. [Figure 7] FIG. 6 is a schematic diagram for explaining the configuration of a laminate of a stacked heat exchanger according to a second embodiment. [Figure 8] FIG. 11 is a schematic diagram for explaining the configuration of a stack of a stack-type heat exchanger according to a modified example of the second embodiment. [Figure 9] FIG. 11 is a schematic diagram for explaining the configuration of a stack of a stack-type heat exchanger according to a modified example of the second embodiment. [Figure 10] FIG. 11 is a schematic diagram for explaining the configuration of a stack of a stack-type heat exchanger according to a modified example of the second embodiment. [Figure 11] 13 is a diagram illustrating a schematic view of a fluid layer, an intermediate medium layer, and a return path of a laminate in a third embodiment. FIG. [Figure 12]FIG. 13 is a diagram for explaining the configuration of a stacked heat exchanger according to a fourth embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0022] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

[0023] (First embodiment) The stacked heat exchanger according to the present embodiment is a heat exchanger that receives a first fluid from a first fluid supply source and a second fluid from a second fluid supply source, and causes heat exchange between the first fluid and the second fluid via an intermediate medium. That is, in this stacked heat exchanger, heat exchange occurs between the first fluid and the intermediate medium, and heat exchange occurs between the intermediate medium and the second fluid, so that heat exchange does not occur directly between the first fluid and the second fluid (or heat exchange is difficult). In addition, since the intermediate medium has a temperature between the temperatures of the first fluid and the second fluid, in this stacked heat exchanger, thermal stress occurring in the stack described below is reduced compared to a heat exchanger that causes heat exchange directly between the first fluid and the second fluid.

[0024] Examples of the first fluid include water, water vapor, and hot water. The second fluid is a fluid with a lower temperature than the first fluid, and examples of the second fluid include liquefied gases such as liquefied natural gas (LNG), liquid hydrogen (LH2), liquefied nitrogen (LN2), and liquid ammonia, and low-temperature gases such as methane gas, ethane gas, and propane gas. The intermediate medium may be any fluid having a temperature lower than the freezing point of the first fluid, and examples of the intermediate medium include alcohols such as methanol, ethanol, 1-propanol, 2-propanol, and butanol, or aqueous solutions thereof. The intermediate medium may be glycols such as ethylene glycol and propylene glycol, or aqueous solutions thereof (antifreeze).

[0025] 1(a)(b) and 2, the stack-type heat exchanger 10 includes a stack 15 having a plurality of fluid layers 11 and a plurality of intermediate medium layers 21. The stack 15 is a stack formed by stacking a plurality of metal plates for constituting the fluid layers 11 and a plurality of metal plates for constituting the intermediate medium layers 21.

[0026] The multiple fluid layers 11 and the multiple intermediate medium layers 21 are stacked such that at least one intermediate medium layer 21 is adjacent to at least one fluid layer 11. In the example shown in Fig. 1, each fluid layer 11 is disposed so as to be sandwiched between a pair of intermediate medium layers 21. The up-down direction in Fig. 1 corresponds to the stacking direction of the fluid layers 11 and the intermediate medium layers 21.

[0027] Each fluid layer 11 includes a high temperature section 12 having a plurality of high temperature flow paths 12a through which a first fluid is introduced, and a low temperature section 13 having a plurality of low temperature flow paths 13a through which a second fluid is introduced. The plurality of high temperature flow paths 12a are arranged in one direction within the layer. The plurality of low temperature flow paths 13a are also arranged in one direction. Each of the high temperature flow paths 12a and each of the low temperature flow paths 13a are formed of a microchannel.

[0028] The plurality of high-temperature flow paths 12a and the plurality of low-temperature flow paths 13a in each fluid layer 11 are arranged in the same layer sandwiched between a pair of intermediate medium layers 21. To create the laminate 15 configured in this way, a flat first metal plate having a plurality of grooves for forming the high-temperature flow paths 12a and a plurality of grooves for forming the low-temperature flow paths 13a on one side, and a pair of flat second metal plates having a plurality of grooves for forming the medium-temperature flow paths 21a described below on one side are prepared. Then, a large number of first and second metal plates are arranged so that the first metal plate is sandwiched between the pair of second metal plates, and these metal plates are diffusion bonded. In this way, the laminate 15 is formed.

[0029] The high temperature portions 12 and the low temperature portions 13 are arranged at positions where they do not overlap with each other in the stacking direction. That is, a plurality of fluid layers 11 are arranged in the stacking direction, but the high temperature portions 12 of each fluid layer 11 are aligned in the stacking direction, and the low temperature portions 13 arranged next to the high temperature portions 12 in each fluid layer 11 are aligned in the stacking direction. This causes a difference between the timing at which the intermediate medium exchanges heat with the first fluid and the timing at which the intermediate medium exchanges heat with the second fluid.

[0030] The high temperature section 12 and the low temperature section 13 are adjacent to each other in the left-right direction (direction perpendicular to the stacking direction) of FIG. 1(b) in the fluid layer 11 via the heat transfer suppression section 17. The heat transfer suppression section 17 is provided to suppress heat exchange between the high temperature section 12 and the low temperature section 13. The heat transfer suppression section 17 is configured to ensure a distance between the high temperature section 12 and the low temperature section 13 so that the distance (intralayer distance) between the high temperature flow path 12a and the low temperature flow path 13a is longer than the distance (stacking direction distance) between the high temperature flow path 12a and the intermediate temperature flow path 21a described later. With this configuration, the first fluid is more likely to exchange heat with the intermediate medium than with the second fluid, so that heat exchange between the first fluid and the second fluid is suppressed.

[0031] The heat transfer suppression portion 17 can be configured, for example, by not forming grooves in the metal plates that configure the laminate 15, thereby making the distance between the high temperature portion 12 and the low temperature portion 13 larger than the groove distance in the high temperature portion 12 and the groove distance in the low temperature portion 13. Note that the configuration is not limited to this, and for example, the heat transfer suppression portion 17 may be configured by forming a cavity in the fluid layer 11, or an intermediate medium may be circulated through this cavity. Note that the heat transfer suppression portion 17 may be omitted depending on the types of the first fluid and the second fluid.

[0032] 2, in each fluid layer 11, the inlet 12b of the high-temperature flow passage 12a and the inlet 13b of the low-temperature flow passage 13a are arranged so as to be as far away from each other as possible. That is, the inlet 12b of the high-temperature flow passage 12a is arranged at a position in the high-temperature section 12 that is the farthest from the low-temperature section 13. The high-temperature flow passage 12a extends from the inlet 12b in a direction along the heat-transfer suppressing section 17, and then extends in a direction approaching the heat-transfer suppressing section 17 while meandering. The outlet 12c of the high-temperature flow passage 12a is arranged at a position close to the heat-transfer suppressing section 17, but is not limited thereto.

[0033] Inlet 13b of low-temperature flow passage 13a is disposed at a position in low-temperature section 13 that is farthest from high-temperature section 12 and heat-transfer suppressing section 17. Low-temperature flow passage 13a extends from inlet 13b in a direction along heat-transfer suppressing section 17, and then extends in a direction approaching heat-transfer suppressing section 17 while meandering. Note that outlet 13c of low-temperature flow passage 13a is disposed at a position close to heat-transfer suppressing section 17, but is not limited to this.

[0034] The inlet 12b of the high-temperature flow passage 12a may be configured by a screw-type connection portion provided to penetrate the fluid layer 11 in the stacking direction as shown in FIG. 2, as long as it is configured to allow the first fluid to flow into the multiple high-temperature flow passages 12a, or may be configured by a header (not shown) attached to the outer surface of the fluid layer 11. Also, the inlet 13b of the low-temperature flow passage 13a may be configured by a screw-type connection portion provided to penetrate the fluid layer 11 in the stacking direction as shown in FIG. 2, as long as it is configured to allow the first fluid to flow into the multiple low-temperature flow passages 13a, or may be configured by a header (not shown) attached to the outer surface of the fluid layer 11. In FIG. 2, the screw-type connection portion constituting the inlet 12b of the high-temperature flow passage 12a and the screw-type connection portion constituting the inlet 13b of the low-temperature flow passage 13a also penetrate the intermediate medium layer 21, but are not connected to the intermediate temperature flow passage 21a described below.

[0035] Each intermediate medium layer 21 is provided with a plurality of medium temperature flow paths 21a into which an intermediate medium is introduced. The plurality of medium temperature flow paths 21a are arranged so as to be aligned in one direction within the layer. Each medium temperature flow path 21a is formed of a microchannel. Note that, although FIG. 1(b) shows a cross section in which the high temperature flow path 12a, the low temperature flow path 13a, and the medium temperature flow path 21a all extend in the same direction, this configuration is not limiting. Any of these may have a portion extending in the same direction, or may have a portion extending in a direction perpendicular to the direction.

[0036] Each medium temperature flow path 21a includes a heating section 21b for heating the intermediate medium flowing in the medium temperature flow path 21a, and a cooling section 21c for cooling the intermediate medium flowing in the medium temperature flow path 21a. Since the heating section 21b and the cooling section 21c are continuous, in the medium temperature flow path 21a, the intermediate medium flows through the cooling section 21c before or after flowing through the heating section 21b.

[0037] The heating section 21b is a portion of the medium temperature flow path 21a located at a position overlapping the high temperature section 12 of the fluid layer 11 in the stacking direction. On the other hand, the cooling section 21c is a portion of the medium temperature flow path 21a located at a position overlapping the low temperature section 13 of the fluid layer 11 in the stacking direction. In other words, the heating section 21b and the cooling section 21c are arranged at positions where they do not overlap each other in the stacking direction. A plurality of intermediate medium layers 21 are arranged in the stacking direction, with the heating sections 21b of each intermediate medium layer 21 aligned in the stacking direction and the cooling sections 21c of each intermediate medium layer 21 aligned in the stacking direction.

[0038] In the heating section 21b, heat exchange occurs between the intermediate medium and the first fluid flowing through the high-temperature flow path 12a so that the intermediate medium is heated, whereas in the cooling section 21c, heat exchange occurs between the intermediate medium and the second fluid flowing through the low-temperature flow path 13a so that the intermediate medium is cooled.

[0039] In Fig. 2, one end 21d of the medium temperature flow passage 21a is disposed near a portion (corresponding portion 22) corresponding to the heat transfer suppressing portion 17 in the cooling portion 21c of the intermediate medium layer 21. The medium temperature flow passage 21a extends from this one end 21d while meandering away from the corresponding portion 22, then extends toward the corresponding portion 22 and passes through the corresponding portion 22, and then extends while meandering within the heating portion 21b while moving away from the heat transfer suppressing portion 17. The other end 21e of the medium temperature flow passage 21a is disposed at a position far away from the corresponding portion 22 within the heating portion 21b. Note that the configuration of the medium temperature flow passage 21a is not limited to this, and various other configurations can be adopted depending on the types of the first fluid, the second fluid, and the intermediate medium.

[0040] 2 shows a case where one end 21d of the medium temperature flow passage 21a located in the cooling section 21c functions as an inlet for the intermediate medium, and the other end 21e of the medium temperature flow passage 21a located in the heating section 21b functions as an outlet for the intermediate medium. However, by changing the direction in which the intermediate medium is sent out by the pump 26 described later, one end 21d of the medium temperature flow passage 21a may function as an outlet for the intermediate medium, and the other end 21e of the medium temperature flow passage 21a may function as an inlet for the intermediate medium.

[0041] 2, a return path 25 for returning the intermediate medium flowing out of the medium temperature flow path 21a to the medium temperature flow path 21a is connected to the stack 15. The return path 25 is provided outside the stack 15. Therefore, the intermediate medium led out from the medium temperature flow path 21a to the outside of the stack 15 flows through the return path 25.

[0042] The return flow path 25 is provided with a pump 26 for flowing the intermediate medium in one direction in the return flow path 25. In the example of Fig. 2, the pump 26 is configured to suck the intermediate medium from the heating section 21b of the medium temperature flow path 21a, and the intermediate medium that has flowed through the return flow path 25 is introduced into the cooling section 21c of the medium temperature flow path 21a. Therefore, the intermediate medium sent out from the pump 26 is introduced into one end 21d of the medium temperature flow path 21a located at the cooling section 21c. In addition, the intermediate medium in the medium temperature flow path 21a is led to the return flow path 25 from the other end 21e of the medium temperature flow path 21a located at the heating section 21b.

[0043] In the laminated heat exchanger 10 configured as above, the first fluid flows into each high-temperature flow passage 12a (high-temperature section 12) through the inlet 12b of the high-temperature flow passage 12a, and the first fluid flows through each high-temperature flow passage 12a. The second fluid flows into each low-temperature flow passage 13a (low-temperature section 13) through the inlet 13b of the low-temperature flow passage 13a, and the second fluid flows through each low-temperature flow passage 13a. Meanwhile, the intermediate medium flows through the medium-temperature flow passage 21a and the return flow passage 25 by the operation of the pump 26. The intermediate medium discharged from the pump 26 flows through the return flow passage 25, and then flows into the cooling section 21c through one end 21d of the medium-temperature flow passage 21a. The intermediate medium flowing through the cooling section 21c is heat exchanged with the second fluid flowing through the low-temperature flow passage 13a, whereby the second fluid is heated and the intermediate medium is cooled. The heated second fluid may be discharged from the stack 15 through the outlet 13c of the low-temperature flow path 13a and may be supplied, for example, to a consumer of the second fluid.

[0044] The intermediate medium cooled in the cooling section 21c flows into the heating section 21b, where it is heat exchanged with the first fluid flowing through the high-temperature flow path 12a. This causes the intermediate medium to be heated and the first fluid to be cooled. The cooled first fluid is discharged from the stack 15 through the outlet 12c of the high-temperature flow path 12a, and may be supplied to a consumer of the first fluid, for example, or may be discarded.

[0045] The intermediate medium that has been heated (or returned to its original temperature) in the heating section 21b is led out of the medium temperature flow path 21a through the other end 21e of the medium temperature flow path 21a and returned to the return path 25. The intermediate medium circulates between the medium temperature flow path 21a and the return path 25 in this manner.

[0046] 3 shows an example of temperature change when the first fluid is water, the second fluid is liquid nitrogen, and the intermediate medium is ethanol. The ethanol is cooled from 12°C to 7°C or less in the cooling section 21c, and then heated from 7°C or less to 12°C in the heating section 21b. The liquid nitrogen flows into the stack 15 at -190°C, is heated by the ethanol in the low temperature section 13, and flows out of the stack 15 at a temperature of 10°C or less. The water flows into the stack 15 at 12°C, is cooled by the ethanol in the high temperature section 12, and flows out of the stack 15 at a temperature of 7°C or less.

[0047] As described above, in the stacked heat exchanger 10 according to this embodiment, the intermediate medium flowing through the intermediate temperature flow path 21a is heat-exchanged with the first fluid in the heating section 21b so as to be heated by the first fluid, and is heat-exchanged with the second fluid in the cooling section 21c so as to be cooled by the second fluid. Therefore, the first fluid can be cooled by the intermediate medium before being discharged, and the second fluid can also be heated by the intermediate medium before being discharged. Therefore, the stacked heat exchanger 10 can be used as a heater for heating the second fluid, and as a cooler for cooling the first fluid.

[0048] The intermediate medium is cooled when the second fluid is heated, but since this intermediate medium is heated in the heating section 21b in the stacked heat exchanger 10, there is no need to provide a new heater for heating the intermediate medium. Also, the intermediate medium is heated when the first fluid is cooled, but since this intermediate medium is cooled in the cooling section 21c in the stacked heat exchanger 10, there is no need to provide a new cooler for cooling the intermediate medium. Therefore, since there is no need to separately provide a heater or cooler, the stacked heat exchanger 10 can be made compact. In other words, the device can be simplified and made smaller.

[0049] Moreover, since the intermediate temperature flow path 21a has the heating section 21b and the cooling section 21c separately, the timing when the intermediate medium is heated by the first fluid and the timing when the intermediate medium is cooled by the second fluid are shifted in the stack 15. Therefore, even if heat exchange is performed between the first fluid and the second fluid via the intermediate medium, the first fluid can be cooled and the second fluid can be heated efficiently. In addition, since the first fluid (high temperature side fluid) does not directly exchange heat with the second fluid, the risk of freezing of the first fluid (high temperature side fluid) can be reduced and the thermal stress generated in the stack 15 can be reduced. Therefore, it is also possible to suppress the durability of the stack 15 from decreasing due to the thermal stress.

[0050] In this embodiment, the heating parts 21b and the cooling parts 21c are arranged at positions where they do not overlap each other in the stacking direction. This makes it possible to prevent the intermediate medium flowing through the medium temperature flow path 21a from being heated by the first fluid and cooled by the second fluid at the same time. This makes it possible to separate the cooling of the first fluid by the intermediate medium from the heating of the second fluid by the intermediate medium. This makes it possible to effectively cool the first fluid and effectively heat the second fluid.

[0051] In this embodiment, the high-temperature flow path 12a (high-temperature section 12) and the low-temperature flow path 13a (low-temperature section 13) are located in the same layer, and a heat transfer suppression section 17 is provided between the high-temperature section 12 and the low-temperature section 13. This makes it possible to prevent the stack 15 from becoming large in the stacking direction, while suppressing direct heat exchange between the first fluid flowing through the high-temperature flow path 12a and the second fluid flowing through the low-temperature flow path 13a.

[0052] In this embodiment, the pump 26 causes the intermediate medium to flow from the cooling section 21c to the heating section 21b, and then flows from the heating section 21b to the return flow path 25. Therefore, even if the intermediate medium is cooled by the second fluid in the cooling section 21c of the medium temperature flow path 21a, it is subsequently heated in the heating section 21b and then flows into the return flow path 25. Therefore, the pump 26 provided in the return flow path 25 can be prevented from being exposed to low temperatures, and low temperature measures for the pump 26 are not required.

[0053] In the above embodiment, as shown in FIG. 1(a), two intermediate medium layers 21 are disposed between a pair of fluid layers 11, and the composition ratio of the fluid layers 11 to the intermediate medium layers 21 is 1:2, but the present invention is not limited to this. For example, as shown in FIG. 4, one intermediate medium layer 21 may be disposed between a pair of fluid layers 11, and the composition ratio of the fluid layers 11 to the intermediate medium layers 21 may be 1:1. Also, as shown in FIG. 5, two fluid layers 11 may be disposed between a pair of intermediate medium layers 21, and the composition ratio of the fluid layers 11 to the intermediate medium layers 21 may be 2:1. Also, as shown in FIG. 6, two intermediate medium layers 21 and two fluid layers 11 may be alternately disposed, and the composition ratio of the fluid layers 11 to the intermediate medium layers 21 may be 2:2. Alternatively, other composition ratios may be used.

[0054] Second embodiment 7 shows the second embodiment. Note that the same components as those in the first embodiment are given the same reference numerals, and detailed description thereof will be omitted.

[0055] In the first embodiment, the high temperature portion 12 and the low temperature portion 13 are arranged adjacent to each other in one fluid layer 11, whereas in the second embodiment, the high temperature portion 12 and the low temperature portion 13 are arranged in different layers. That is, the fluid layer 11 has a high temperature layer 11a having a high temperature flow path 12a (high temperature portion 12) but not a low temperature flow path 13a (low temperature portion 13), and a low temperature layer 11b having a low temperature flow path 13a (low temperature portion 13) but not a high temperature flow path 12a (high temperature portion 12). Therefore, only one of the high temperature portion 12 and the low temperature portion 13 is formed in one fluid layer 11 located between a pair of intermediate medium layers 21.

[0056] The high temperature portion 12 is formed only in a part of the fluid layer 11 (high temperature layer 11a), and the high temperature flow path 12a is not formed in the remaining part. Similarly, the low temperature portion 13 is formed only in a part of the fluid layer 11 (low temperature layer 11b), and the low temperature flow path 13a is not formed in the remaining part. Even in this form, the multiple high temperature portions 12 and the multiple low temperature portions 13 are arranged in positions where they do not overlap with each other in the stacking direction. That is, the multiple fluid layers 11 are arranged in the stacking direction, but the high temperature portions 12 of each fluid layer 11 are aligned in the stacking direction, and the low temperature portions 13 of each fluid layer 11 are aligned in the stacking direction next to them.

[0057] Therefore, according to this embodiment, direct heat exchange between the first fluid flowing through the high-temperature flow path 12a and the second fluid flowing through the low-temperature flow path 13a can be suppressed.

[0058] The composition ratio of the fluid layer 11 to the intermediate medium layer 21 is not limited to 1:2 as shown in FIG. 7, but may be 1:1 as shown in FIG. 8, 2:1 as shown in FIG. 9, 2:2 as shown in FIG. 10, or some other composition ratio.

[0059] Although a description of the other configurations, operations, and effects will be omitted, the description of the first embodiment can be applied to the second embodiment.

[0060] Third embodiment 11 shows the third embodiment. Note that the same components as those in the first embodiment are given the same reference numerals, and detailed description thereof will be omitted.

[0061] In the first embodiment, the pump 26 is set so that the intermediate medium flows from the cooling section 21c to the heating section 21b in the intermediate medium layer 21, whereas in the third embodiment, the pump 26 is set so that the intermediate medium flows from the heating section 21b to the cooling section 21c in the intermediate medium layer 21. Therefore, the intermediate medium cooled by the second fluid in the cooling section 21c flows into the return path 25. Therefore, in the third embodiment, a cold energy utilization section 30 is provided in the return path 25. The cold energy utilization section 30 is for extracting cold energy from the intermediate medium flowing through the return path 25, and can be, for example, a chiller for generating cold water.

[0062] The intermediate medium exchanges heat with other fluids in the cold heat utilization section 30, and is therefore heated in the cold heat utilization section 30. For this reason, it is preferable that the cold heat utilization section 30 is disposed upstream of the pump 26 in the return flow path 25. This makes it possible to prevent a low-temperature intermediate medium from flowing into the pump 26. However, depending on the temperature of the intermediate medium flowing into the return flow path 25, the cold heat utilization section 30 may be disposed downstream of the pump 26.

[0063] According to this embodiment, the intermediate medium cooled by the second fluid flows through the return flow path 25, and the return flow path 25 is provided with a cold energy utilization section 30 that extracts the cold energy of the intermediate medium. This makes it possible to utilize the cold energy of the intermediate medium outside. Note that the temperature of the intermediate medium that has provided the cold energy in the cold energy utilization section 30 rises, and this intermediate medium with the increased temperature flows into the heating section 21b of the medium temperature flow path 21a. In some cases, the flow rate of the first fluid can be reduced accordingly.

[0064] In the third embodiment, the cold energy utilization unit 30 may be omitted. The other configurations, operations, and effects will not be described, but the descriptions of the first and second embodiments can be applied to the third embodiment.

[0065] (Fourth embodiment) 12 shows the fourth embodiment. Note that the same components as those in the first embodiment are given the same reference numerals, and detailed description thereof will be omitted.

[0066] The stacked-type heat exchanger 10 according to the fourth embodiment also includes a second stack 35 formed integrally with the stack 15. The second stack 35 includes a second fluid layer 41 and a second intermediate medium layer 51, which have the same configurations as the fluid layer 11 and the intermediate medium layer 21 of the stack 15, and these are stacked together. The second stack 35 may have the same configuration as the stack 15 shown in Figs. 1, 2, and 4 to 10.

[0067] The second fluid layer 41 has a plurality of second high temperature flow paths (second high temperature sections 42) into which the first fluid is introduced, and a plurality of second low temperature flow paths (second low temperature sections 43) into which the second fluid is introduced. The second high temperature flow paths are configured similarly to the high temperature flow path 12a (first high temperature flow path), and the second low temperature flow path is configured similarly to the low temperature flow path 13a (first low temperature flow path). The first fluid, which is the same type of fluid as the first fluid in the laminate 15, is introduced into the second high temperature flow path. The second fluid, which is the same type of fluid as the second fluid in the laminate 15, is introduced into the second low temperature flow path.

[0068] The second high temperature section 42 and the second low temperature section 43 are arranged at positions where they do not overlap with each other in the stacking direction. That is, a plurality of second fluid layers 41 are arranged in the stacking direction, but the second high temperature sections 42 of each second fluid layer 41 are aligned in the stacking direction, and the second low temperature sections 43 of each second fluid layer 41 are aligned in the stacking direction at a position beside them. For this reason, even in the second stack 35, the timing at which the intermediate medium exchanges heat with the first fluid is shifted from the timing at which the intermediate medium exchanges heat with the second fluid.

[0069] A heat transfer suppressing portion (not shown) is provided between the second high temperature portion 42 and the second low temperature portion 43. This heat transfer suppressing portion has a similar configuration to the heat transfer suppressing portion 17 provided in the fluid layer 11 of the stack 15.

[0070] The second intermediate medium layer 51 has a second medium-temperature flow path 51a into which the intermediate medium is introduced, and the second medium-temperature flow path 51a includes a second heating section 51b and a second cooling section 51c. Note that the intermediate medium introduced into the second medium-temperature flow path 51a is an intermediate medium composed of the same kind of fluid as the intermediate medium introduced into the medium-temperature flow path 21a of the laminate 15.

[0071] The second medium-temperature flow path 51a is constituted by microchannels. In the second medium-temperature flow path 51a, the intermediate medium flows from the second heating section 51b toward the second cooling section 51c. The second heating section 51b is a part where heat exchange occurs between the intermediate medium and the first fluid flowing through the second high-temperature flow path, and is configured in the same manner as the heating section 21b (the first heating section). The second cooling section 51c is a part where heat exchange occurs between the intermediate medium that has flowed through the second heating section 51b and the second fluid flowing through the second low-temperature flow path, and is configured in the same manner as the cooling section 21c (the first cooling section).

[0072] A second reflux path 55 for returning the intermediate medium flowing out from the second medium-temperature flow path 51a to the second medium-temperature flow path 51a is connected to the second laminate 35. A second pump 56 is provided in the second reflux path 55. The second pump 56 sucks the intermediate medium from the second cooling section 51c in the second medium-temperature flow path 51a, and is configured such that the intermediate medium flowing through the second reflux path 55 is introduced into the second heating section 51b in the second medium-temperature flow path 51a.

[0073] A cold heat utilization section 30 is provided in the second reflux path 55. The cold heat utilization section 30 is for extracting the cold heat of the intermediate medium flowing through the second reflux path 55. The intermediate medium exchanges heat with other fluids in the cold heat utilization section 30, and thus will be heated in the cold heat utilization section 30. For this reason, the cold heat utilization section 30 is preferably arranged upstream of the second pump 56 in the second reflux path 55. By doing so, it is possible to prevent the low-temperature intermediate medium from flowing into the second pump 56.

[0074] Therefore, according to this embodiment, the intermediate medium cooled by the second fluid in the second cooling section 51c of the second medium-temperature flow path 51a flows through the second return path 55. The second return path 55 is provided with a cold energy utilization section 30 that receives the cold energy of the cooled intermediate medium, so that the cold energy of the intermediate medium can be utilized outside. Meanwhile, in the cooling section 21c of the medium-temperature flow path 21a of the laminate 15, the intermediate medium is cooled by the second fluid, but this medium-temperature medium is then heated in the heating section 21b before flowing into the return path 25. Therefore, the pump 26 provided in the return path 25 can be prevented from being exposed to low temperatures, and low-temperature measures for the pump 26 are not required.

[0075] It should be noted that the explanations of the other configurations, operations and effects will be omitted, but the explanations of the first to third embodiments can be applied to the fourth embodiment.

[0076] The embodiments disclosed herein should be considered to be illustrative and not restrictive in all respects. The present invention is not limited to the above-described embodiments, and various modifications and improvements can be made without departing from the spirit and scope of the present invention. [Explanation of symbols]

[0077] 10: Stacked heat exchanger 11:Fluid layer 11a: High temperature layer 11b: Low temperature layer 12: High temperature section 12a: High temperature flow path 13: Low temperature section 13a: Low temperature flow path 15: Laminate 17: Heat transfer suppression section 21: Intermediate medium layer 21a: Medium temperature flow path 21b:Heating section 21c: Cooling section 25: Circulation channel 26: Pump 30: Cold and heat utilization section 35: Second laminate 41:Second fluid layer 51: 2nd intermediate medium layer 51a: Second medium temperature flow path 51b: 2nd heating section 51c: 2nd cooling section 55: Second return channel

Claims

1. a fluid layer having a high-temperature flow path into which a first fluid is introduced and a low-temperature flow path into which a second fluid having a lower temperature than the first fluid is introduced; an intermediate medium layer laminated on the fluid layer and having a medium temperature flow path into which an intermediate medium having a lower temperature than the first fluid and a higher temperature than the second fluid is introduced; A laminate having The medium temperature flow path of the intermediate medium layer includes a heating section that generates heat exchange between the intermediate medium flowing through the medium temperature flow path and the first fluid flowing through the high temperature flow path, and a cooling section that generates heat exchange between the intermediate medium before or after flowing through the heating section and the second fluid flowing through the low temperature flow path, The stacked heat exchanger further includes a return passage that returns the intermediate medium flowing out of the medium temperature passage to the medium temperature passage.

2. 2 . The stacked heat exchanger according to claim 1 , wherein the heating section and the cooling section are arranged at positions not overlapping with each other in a stacking direction of the fluid layers and the intermediate medium layers in the stack.

3. 3. The stacked heat exchanger of claim 2, wherein the fluid layers have a high temperature layer having the high temperature flow path but not the low temperature flow path, and a low temperature layer having the low temperature flow path but not the high temperature flow path.

4. the high temperature flow path and the low temperature flow path are located in the same layer; 3. The stacked heat exchanger according to claim 2, further comprising a heat transfer suppression section for suppressing heat exchange between the first fluid and the second fluid, the heat transfer suppression section being provided between the high temperature section in which the high temperature flow path is provided and the low temperature section in which the low temperature flow path is provided.

5. 3. The stacked heat exchanger according to claim 1, wherein the return flow path is provided with a pump for moving the intermediate medium so that the intermediate medium flows from the heating section to the cooling section in the medium temperature flow path and then flows from the cooling section to the return flow path, and a cold heat utilization section for receiving the cold heat of the intermediate medium.

6. 3. The stacked heat exchanger according to claim 1, wherein the return flow path is provided with a pump for moving the intermediate medium so that the intermediate medium flows from the cooling section to the heating section in the medium temperature flow path and then flows out of the heating section into the return flow path.

7. a second fluid layer having a second high-temperature flow path into which a first fluid is introduced and a second low-temperature flow path into which a second fluid having a lower temperature than the first fluid is introduced; a second intermediate medium layer laminated on the second fluid layer and having a second intermediate temperature flow passage through which an intermediate medium having a temperature between the first fluid and the second fluid is introduced; A second stack having The second intermediate medium layer includes a second heating section that generates heat exchange between the intermediate medium and a first fluid flowing through the second high temperature flow path, and a second cooling section that generates heat exchange between the intermediate medium after flowing through the second heating section and a second fluid flowing through the second low temperature flow path, A second return flow path is provided for returning the intermediate medium flowing out of the second cooling section of the second medium temperature flow path to the second heating section of the second medium temperature flow path, The stacked heat exchanger according to claim 6 , wherein the second return passage is provided with a cold heat utilization section that receives the cold heat of the intermediate medium.

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