Heat exchange system

Abstract

To provide a heat exchange system capable of suppressing freezing of a high temperature fluid when executing heat exchange between a low temperature fluid and a high temperature fluid of a fluid.SOLUTION: A heat exchange system 100 includes: a first heat exchanging part 3 for executing heat exchange between a low temperature fluid 80 and a high temperature fluid.81; and a second heat exchanging part 4 for executing heat exchange between the low temperature fluids 80. The second heat exchanging part 4 which includes a first inlet 4a into which the low temperature fluid 80 flows, a first outlet 4b communicated with the first inlet 4a, a second inlet 4c into which the low temperature fluid 80 flows, and a second outlet 4d communicated with the second inlet 4c is configured so as to execute heat exchange between the low temperature fluid 80 flowing from the first inlet 4a and the low temperature fluid 80 flowing from the second inlet 4c, and includes a heating part for heating the low temperature fluid 80 before flowing into the second inlet 4c. The second outlet 4d is communicated with the first heat exchanging part 3, and the low temperature fluid 80 subjected to heat exchange by the second heat exchanging part 4 and outflowing from the second outlet 4d is caused to flow into the first heat exchanging part 3 so that heat exchange is carried out with the high temperature fluid 81.SELECTED DRAWING: Figure 4

Description

Technical Field

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[0001] This invention relates to a heat exchange system, and particularly to a heat exchange system that performs heat exchange between a low-temperature fluid, which is a low-temperature fluid, and a high-temperature fluid, which is a high-temperature fluid.

Background Art

[0002] Conventionally, a heat exchange system that performs heat exchange between a low-temperature fluid, which is a low-temperature fluid, and a high-temperature fluid, which is a high-temperature fluid, is known (see, for example, Patent Document 1).

[0003] Patent Document 1 discloses a heat exchanger that performs heat exchange between a low-temperature fluid, which is a low-temperature fluid, and a high-temperature fluid, which is a high-temperature fluid. The heat exchanger disclosed in Patent Document 1 is a plate fin type heat exchanger in which a first passage through which a first fluid flows and a second passage through which a second fluid flows are alternately stacked. The heat exchanger disclosed in Patent Document 1 is particularly used for applications such as liquefaction or vaporization of natural gas where the temperature difference between fluids is large.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] Here, in the heat exchanger (heat exchange system) disclosed in Patent Document 1, the first passage and the second passage are alternately stacked. Therefore, for example, when the first fluid (low-temperature fluid) on the low-temperature side is an extremely low-temperature liquefied gas and the second fluid (high-temperature fluid) on the high-temperature side is water or antifreeze, etc., when performing heat exchange between the low-temperature fluid and the liquid high-temperature fluid, there is a problem that the high-temperature fluid may freeze.

[0006] This invention was made to solve the above-mentioned problems, and one of its objectives is to provide a heat exchange system that can suppress the freezing of a high-temperature fluid when heat exchange is performed between a low-temperature fluid and a high-temperature liquid fluid. [Means for solving the problem]

[0007] To achieve the above objective, the heat exchange system according to this invention comprises a first heat exchange section that performs heat exchange between a low-temperature fluid (a low-temperature flow) and a high-temperature fluid (a liquid at a higher temperature than the low-temperature fluid), and a second heat exchange section that performs heat exchange between low-temperature fluids, wherein the second heat exchange section has a first inlet into which the low-temperature fluid flows in, a first outlet communicating with the first inlet and out which the low-temperature fluid that flowed in from the first inlet after heat exchange flows out, a second inlet into which the low-temperature fluid that flowed out from the first outlet flows in, and a heat exchange section communicating with the second inlet The system includes a second outlet from which the low-temperature fluid that flowed in from the second inlet after the exchange flows out, and is configured to exchange heat between the low-temperature fluid that flowed in from the first inlet and the low-temperature fluid that flowed in from the second inlet. It is provided between the first outlet and the second inlet and includes a heating section that heats the low-temperature fluid after it flows out from the first outlet and before it flows into the second inlet. The second outlet is in communication with the first heat exchange section and heat is exchanged by the second heat exchange section. The low-temperature fluid that flows out from the second outlet flows into the first heat exchange section and exchanges heat with the high-temperature fluid.

[0008] The heat exchange system according to this invention comprises, as described above, a first heat exchange section that performs heat exchange between a low-temperature fluid and a high-temperature fluid, a second heat exchange section that performs heat exchange between low-temperature fluids, and a heating section that heats the low-temperature fluid after it flows out from the first outlet and before it flows into the second inlet. The low-temperature fluid that has undergone heat exchange by the second heat exchange section flows into the first heat exchange section and undergoes heat exchange with the high-temperature fluid. As a result, the low-temperature fluid is heated by the second heat exchange section before it flows into the first heat exchange section, so the low-temperature fluid that flows into the first heat exchange section can be preheated. Therefore, compared to a configuration without a second heat exchange section, the temperature difference between the low-temperature fluid flowing into the first heat exchange section and the liquid high-temperature fluid can be reduced. As a result, freezing of the high-temperature fluid can be suppressed when heat exchange is performed between the low-temperature fluid and the liquid high-temperature fluid.

[0009] In the heat exchange system according to the above invention, preferably, the first heat exchange section also serves as a heating section, and the first heat exchange section includes a first low-temperature side inlet into which a low-temperature fluid flows, and a first low-temperature side outlet communicating with the first low-temperature side inlet, and the first outlet of the second heat exchange section communicates with the first low-temperature side inlet of the first heat exchange section, and the low-temperature fluid that flows out from the first outlet flows into the first heat exchange section from the first low-temperature side inlet, exchanges heat with the high-temperature fluid, and then flows back into the second heat exchange section from the second inlet. With this configuration, the low-temperature fluid that flows out from the first outlet can be heated by the first heat exchange section and returned to the second heat exchange section from the second inlet.Therefore, the low-temperature fluid that flows in from the second inlet can be heated without providing a heater or the like for heating the low-temperature fluid that flows out from the first outlet.As a result, the size of the heat exchange system can be suppressed compared to a configuration in which a heater or the like is provided for heating the low-temperature fluid that flows out from the first outlet.

[0010] Furthermore, in this case, the low-temperature fluid flowing out from the first outlet is at a higher temperature than the low-temperature fluid flowing in from the first inlet, and the low-temperature fluid flowing out from the second outlet is at a higher temperature than the low-temperature fluid flowing in from the first inlet. In other words, both the low-temperature fluid flowing out from the first outlet and into the first heat exchange section, and the low-temperature fluid flowing out from the second outlet and into the first heat exchange section, enter the first heat exchange section at a higher temperature than the low-temperature fluid flowing in from the first inlet. Therefore, compared to a configuration in which the low-temperature fluid flows directly into the first heat exchange section without passing through the second heat exchange section, the temperature difference between the low-temperature fluid and the high-temperature fluid can be reduced. As a result, compared to a configuration in which the low-temperature fluid flows directly into the second heat exchange section without passing through the second heat exchange section, the freezing of the liquid high-temperature fluid can be suppressed.

[0011] In a configuration in which the low-temperature fluid is returned to the second heat exchange section from the second inlet, preferably, the first heat exchange section further includes a second low-temperature side inlet communicating with the second outlet of the second heat exchange section, and a second low-temperature side outlet communicating with the second low-temperature side inlet. The low-temperature fluid that flows out from the second outlet of the second heat exchange section flows into the first heat exchange section from the second low-temperature side inlet and exchanges heat with the high-temperature fluid. With this configuration, since the second low-temperature side inlet of the first heat exchange section and the second outlet of the second heat exchange section are in communication, the low-temperature fluid that has undergone heat exchange in the second heat exchange section can be easily introduced into the first heat exchange section. As a result, a fluid circuit can be easily formed in which the low-temperature fluid can be introduced into the first heat exchange section after being preheated by the second heat exchange section.

[0012] In this case, preferably, the first heat exchange section is configured to perform heat exchange between the high-temperature fluid and the low-temperature fluid flowing in from the first low-temperature side inlet of the first heat exchange section, and between the high-temperature fluid and the low-temperature fluid flowing in from the second low-temperature side inlet of the first heat exchange section. With this configuration, the first heat exchange section can perform heat exchange between the three fluids: the high-temperature fluid, the low-temperature fluid flowing in from the first low-temperature side inlet, and the low-temperature fluid flowing in from the second low-temperature side inlet. As a result, compared to a configuration that includes a heat exchange section that performs heat exchange between the high-temperature fluid and the low-temperature fluid flowing in from the first low-temperature side inlet, and a heat exchange section that performs heat exchange between the high-temperature fluid and the low-temperature fluid flowing in from the second low-temperature side inlet, it is possible to suppress an increase in the number of parts and an increase in structural complexity.

[0013] In a configuration where the low-temperature fluid flowing out from the first outlet and the low-temperature fluid flowing out from the second outlet are at a higher temperature than the low-temperature fluid flowing in from the first inlet, it is preferable that the first heat exchange section and the second heat exchange section are provided in different first and second heat exchangers, respectively. With this configuration, by connecting the first heat exchanger equipped with the first heat exchange section and the second heat exchanger equipped with the second heat exchange section, a fluid circuit can be easily formed in which the temperature of the low-temperature fluid flowing into the first heat exchange section can be preheated by the second heat exchange section. As a result, for example, compared to a single heat exchanger equipped with both the first and second heat exchange sections, the complexity of the heat exchanger piping installation can be suppressed.

[0014] In a configuration where the cryogenic fluid flowing out from the first outlet and the cryogenic fluid flowing out from the second outlet are at a higher temperature than the cryogenic fluid flowing in from the first inlet, preferably the system further comprises a cryogenic fluid tank for storing liquid cryogenic fluid, a cryogenic fluid pump for circulating the cryogenic fluid stored in the cryogenic fluid tank through a cryogenic flow path, a cryogenic fluid storage section for storing cryogenic fluid that has been heated by the first heat exchange section and vaporized, a supply section connected to the cryogenic fluid storage section for supplying the vaporized cryogenic fluid to the target, and a branch flow path that branches off from the cryogenic flow path and connects to the supply section for circulating the cryogenic fluid, wherein the supply section is configured to mix the cryogenic fluid flowing in from the cryogenic fluid storage section with a cryogenic fluid flowing in from the branch flow path that is at a lower temperature than the cryogenic fluid stored in the cryogenic fluid storage section. With this configuration, when the temperature of the cryogenic fluid stored in the cryogenic fluid storage section is lowered before supplying it to the target, the temperature of the cryogenic fluid can be easily lowered by mixing the cryogenic fluid stored in the cryogenic fluid storage section with the cryogenic fluid flowing in from the branch flow path. Therefore, the temperature of the cryogenic fluid stored in the storage unit can be lowered to the temperature at which it is provided to the target without using a refrigerator or the like. As a result, the system can be kept from becoming oversized compared to, for example, a configuration that includes a refrigerator or the like to lower the temperature of the cryogenic fluid stored in the storage unit.

[0015] In the heat exchange system according to the above invention, preferably, the low-temperature fluid is liquid hydrogen and the high-temperature fluid is warm water. With this configuration, it is possible to provide a heat exchange system capable of suppressing freezing of the warm water when heat exchange is performed between the liquid hydrogen as the low-temperature fluid and the warm water as the high-temperature fluid.

Effects of the Invention

[0016] According to the present invention, as described above, it is possible to provide a heat exchange system capable of suppressing freezing of the high-temperature fluid when heat exchange is performed between the low-temperature fluid and the liquid high-temperature fluid.

Brief Description of the Drawings

[0017] [Figure 1] It is a schematic diagram for explaining the overall configuration of the heat exchange system according to one embodiment. [Figure 2] It is a schematic perspective view for explaining the configuration of the first heat exchanger including the first heat exchange section according to one embodiment. [Figure 3] It is a schematic perspective view for explaining the configuration of the second heat exchanger including the second heat exchange section according to one embodiment. [Figure 4] It is a schematic diagram for explaining the configuration in which the first heat exchange section and the second heat exchange section are connected according to one embodiment, and the flow paths of the low-temperature fluid and the high-temperature fluid. [Figure 5] It is a schematic diagram for explaining heat exchange between the first fluids and heat exchange between the first fluid and the second fluid in the heat exchange system according to one embodiment. [Figure 6] It is a schematic diagram for explaining the overall configuration of the heat exchange system according to a modified example.

Modes for Carrying Out the Invention

[0018] Hereinafter, embodiments of the present invention will be described based on the drawings.

[0019] Referring to FIGS. 1 to 5, the heat exchange system 100 according to one embodiment will be described.

[0020] (Structure of the heat exchange system) As shown in FIG. 1, the heat exchange system 100 includes a low-temperature flow path 1, a high-temperature flow path 2, a first heat exchange unit 3, a second heat exchange unit 4, and a heating unit. Further, in the present embodiment, the heat exchange system 100 includes a low-temperature fluid tank 5, a low-temperature fluid pump 6, and a low-temperature fluid storage unit 7. Further, in the present embodiment, the heat exchange system 100 includes a supply unit 8 and a branch flow path 9. Further, in the present embodiment, the heat exchange system 100 includes a high-temperature fluid tank 30.

[0021] The low-temperature flow path 1 is a flow path through which a low-temperature fluid 80, which is a low-temperature fluid, flows. One end of the low-temperature flow path 1 is connected to the low-temperature fluid pump 6, and the other end is connected to the low-temperature fluid storage unit 7. The low-temperature flow path 1 is, for example, a pipe. Note that the low-temperature fluid 80 includes, for example, liquid hydrogen, liquid helium, and liquefied natural gas. In the present embodiment, the low-temperature fluid 80 is liquid hydrogen.

[0022] In the present embodiment, the low-temperature flow path 1 includes a first low-temperature flow path portion 1a, a second low-temperature flow path portion 1b, a third low-temperature flow path portion 1c, a fourth low-temperature flow path portion 1d, and a fifth low-temperature flow path portion 1e.

[0023] The first low-temperature flow path portion 1a is configured to connect the low-temperature fluid pump 6 and the second heat exchange unit 4. The second low-temperature flow path portion 1b is configured to connect the second heat exchange unit 4 and the first heat exchange unit 3. The third low-temperature flow path portion 1c is configured to connect the first heat exchange unit 3 and the second heat exchange unit 4. The fourth low-temperature flow path portion 1d is configured to connect the second heat exchange unit 4 and the first heat exchange unit 3. The fifth low-temperature flow path portion 1e is configured to connect the first heat exchange unit 3 and the low-temperature fluid storage unit 7.

[0024] Therefore, the cryogenic fluid 80 stored in the cryogenic fluid tank 5 is circulated by the cryogenic fluid pump 6 in the following order: first cryogenic flow path 1a, second heat exchange section 4, second cryogenic flow path 1b, first heat exchange section 3, third cryogenic flow path 1c, second heat exchange section 4, fourth cryogenic flow path 1d, first heat exchange section 3, and fifth cryogenic flow path 1e, and stored in the cryogenic fluid storage section 7. In this embodiment, the heat exchange system 100 is a system that stores gaseous cryogenic fluid 80b (hydrogen gas), which is obtained by vaporizing liquid cryogenic fluid 80a, which is liquid hydrogen, by performing heat exchange in the first heat exchange section 3 and the second heat exchange section 4, in the cryogenic fluid storage section 7.

[0025] The high-temperature channel 2 is a channel through which a high-temperature fluid 81, which is a liquid at a higher temperature than the low-temperature fluid 80, flows. A first heat exchange section 3 is provided in the middle of the high-temperature channel 2. The high-temperature channel 2 is, for example, a pipe. The high-temperature fluid 81 includes, for example, hot water, ethylene glycol, etc. In this embodiment, the high-temperature fluid 81 is hot water. Preferably, the hot water is water heated to a temperature of 40°C to 70°C. More preferably, the hot water is water heated to a temperature of 50°C to 60°C.

[0026] In this embodiment, the high-temperature flow path 2 includes a first high-temperature flow path section 2a and a second high-temperature flow path section 2b.

[0027] The first high-temperature flow channel 2a is configured to connect the high-temperature fluid tank 30 and the first heat exchange section 3. The second high-temperature flow channel 2b is configured to connect the first heat exchange section 3 and the high-temperature fluid tank 30. Therefore, the high-temperature fluid 81 that flows out of the high-temperature fluid tank 30 flows through the first high-temperature flow channel 2a, the first heat exchange section 3, and the second high-temperature flow channel 2b, and then flows back into the high-temperature fluid tank 30.

[0028] The first heat exchange section 3 also serves as a heating section. The first heat exchange section 3 is configured to perform heat exchange between the low-temperature fluid 80 and the high-temperature fluid 81. The first heat exchange section 3 is provided in the first heat exchanger 10. The detailed configuration of the first heat exchange section 3 and the first heat exchanger 10 will be described later.

[0029] The second heat exchange section 4 is configured to perform heat exchange between the low-temperature fluids 80. In this embodiment, the second heat exchange section 4 is provided in the second heat exchanger 20, which is connected to the first heat exchanger 10. That is, the first heat exchange section 3 and the second heat exchange section 4 are provided in different heat exchange sections 3 and 4, respectively. In other words, the first heat exchange section 3 and the second heat exchange section 4 are provided separately. The second heat exchanger 20 is connected to the first heat exchanger 10 by a low-temperature flow path 1. The detailed configuration of the second heat exchange section 4 and the second heat exchanger 20 will be described later.

[0030] In this embodiment, as shown in Figure 1, a second flow control valve 32 is provided in the second low-temperature flow path section 1b, which connects the second heat exchange section 4 and the first heat exchange section 3 of the low-temperature flow path 1. The second flow control valve 32 is located at a position that separates the low-temperature flow path 1 from the branch flow path 9. The second flow control valve 32 is configured to adjust the flow rate of the low-temperature fluid 80 flowing through the low-temperature flow path 1 and the flow rate of the low-temperature fluid 80 flowing through the branch flow path 9. Therefore, by controlling the second flow control valve 32, the flow rate of the low-temperature fluid 80 flowing from the second heat exchange section 4 to the first heat exchange section 3 and the flow rate of the low-temperature fluid 80 flowing through the branch flow path 9 are adjusted. The second flow control valve 32 is configured to adjust the amount of low-temperature fluid 80 flowing through the low-temperature flow path 1 and the amount of low-temperature fluid 80 flowing through the branch flow path 9. In other words, by adjusting the flow rate of the low-temperature fluid 80, the second flow control valve 32 makes it possible to flow the low-temperature fluid 80 through both the low-temperature flow path 1 and the branch flow path 9. Furthermore, the second flow control valve 32 is configured to allow the low-temperature fluid 80 to flow only through the low-temperature flow path 1, or to flow only through the branch flow path 9, by adjusting the flow rate of the low-temperature fluid 80. The second flow control valve 32 may also be electrically controlled (automatically controlled) by a control circuit (not shown) or mechanically controlled (manually controlled) by a person or other means.

[0031] The cryogenic fluid tank 5 is configured to store a liquid cryogenic fluid 80.

[0032] The cryogenic fluid pump 6 is configured to circulate the cryogenic fluid 80 stored in the cryogenic fluid tank 5 through the cryogenic flow path 1. The cryogenic fluid pump 6 is connected to the cryogenic fluid tank 5 and the cryogenic flow path 1, and is configured to circulate the cryogenic fluid 80 stored in the cryogenic fluid storage section 7 through the cryogenic flow path 1. In this embodiment, the cryogenic fluid pump 6 is also configured to pressurize the cryogenic fluid 80 to a predetermined pressure. The predetermined pressure is, for example, 80 MPa (megapascals). The type of cryogenic fluid pump 6 is not limited as long as it is possible to pressurize the cryogenic fluid 80 to the predetermined pressure and then circulate the cryogenic fluid 80 through the cryogenic flow path 1.

[0033] The cryogenic fluid storage section 7 is configured to store the cryogenic fluid 80 that has been heated and vaporized by the first heat exchange section 3. The cryogenic fluid storage section 7 is connected to the cryogenic flow path 1 and the supply flow path 8a, which will be described later. The cryogenic fluid storage section 7 stores the cryogenic fluid 80 that flows in from the cryogenic flow path 1 at a predetermined temperature. In this embodiment, the cryogenic fluid storage section 7 is configured to store gaseous cryogenic fluid 80b. The cryogenic fluid storage section 7 is also configured to discharge the cryogenic fluid 80 (gasic cryogenic fluid 80b) to the supply flow path 8a. The cryogenic fluid storage section 7 is, for example, an accumulator.

[0034] Furthermore, a first flow rate control valve 31 is provided in the fifth low-temperature flow path section 1e between the first heat exchange section 3 and the low-temperature fluid storage section 7. The first flow rate control valve 31 is configured to adjust the flow rate of the low-temperature fluid 80 flowing through the low-temperature flow path 1. Therefore, the flow rate of the low-temperature fluid 80 flowing into the low-temperature fluid storage section 7 is adjusted by controlling the first flow rate control valve 31 and the second flow rate control valve 32. The first flow rate control valve 31 may be electrically controlled (automatically controlled) by a control circuit (not shown) or mechanically controlled (manually controlled) by a person or other means.

[0035] The supply unit 8 is connected to the cryogenic fluid storage unit 7 and is configured to supply vaporized cryogenic fluid 80 to the supply target 90. The supply unit 8 includes a supply channel 8a, a first supply valve 8b, and a second supply valve 8c. The supply unit 8 is also connected to a dispenser 91 for supplying cryogenic fluid 80 to the supply target 90. For example, the dispenser is one that supplies vaporized cryogenic fluid 80. The supply target 90 is, for example, an automobile.

[0036] The first supply valve 8b is configured to adjust the flow rate of the cryogenic fluid 80 that flows from the cryogenic fluid storage section 7 to the supply channel 8a. The first supply valve 8b is, for example, a flow control valve.

[0037] The second supply valve 8c is configured to adjust the flow rate of the cryogenic fluid 80 supplied to the target 90. The second supply valve 8c is, for example, a flow control valve.

[0038] The branch channel 9 is configured to branch off from the low-temperature channel 1 (second low-temperature channel section 1b) and connect to the supply section 8, allowing the low-temperature fluid 80 to flow through it. One side of the branch channel 9 is connected to the low-temperature channel 1 (second low-temperature channel section 1b) via the second flow control valve 32, and the other side is connected to the supply channel 8a. The branch channel 9 is a channel for circulating the low-temperature fluid 80 flowing through the low-temperature channel 1 to the supply channel 8a. The branch channel 9 is, for example, a pipe.

[0039] The high-temperature fluid tank 30 is configured to store the high-temperature fluid 81. The high-temperature fluid tank 30 is connected to the first heat exchange unit 3 by a high-temperature flow path 2. A third flow control valve 33 is provided between the high-temperature fluid tank 30 and the first heat exchange unit 3 in the high-temperature flow path 2.

[0040] The third flow control valve 33 is configured to adjust the flow rate of the high-temperature fluid 81 that flows from the high-temperature fluid tank 30 to the first heat exchange section 3. Furthermore, while the heat exchange system 100 is operating, the third flow control valve 33 is adjusted to allow the high-temperature fluid 81 to flow through the high-temperature flow path 2. Specifically, the third flow control valve 33 is configured to continuously flow the high-temperature fluid 81 while the heat exchange system 100 is operating. The third flow control valve 33 may be electrically controlled (automatically controlled) by a control circuit (not shown) or mechanically controlled (manually controlled) by a person.

[0041] As shown in Figure 1, the cryogenic fluid 80 (liquid cryogenic fluid 80a) stored in the cryogenic fluid tank 5 flows into the second heat exchange section 4 and the first heat exchange section 3 via the cryogenic flow path 1. The cryogenic fluid 80 then undergoes heat exchange in the second heat exchange section 4 and the first heat exchange section 3, and after vaporization, is stored in the cryogenic fluid storage section 7 as gaseous cryogenic fluid 80b. The vaporized cryogenic fluid 80 (gasic cryogenic fluid 80b) stored in the cryogenic fluid storage section 7 is supplied to the target 90 by the dispenser 91 via the supply section 8.

[0042] Furthermore, the high-temperature fluid 81 stored in the high-temperature fluid tank 30 flows into the first heat exchange section 3 via the high-temperature flow path 2. After heat exchange in the first heat exchange section 3, the high-temperature fluid 81 is heated by a heater (not shown) and flows into the high-temperature fluid tank 30. The high-temperature fluid 81 after heat exchange may also be discharged into a fluid discharge section (not shown).

[0043] (1st heat exchanger) Next, the first heat exchanger 10 will be described with reference to Figure 2. As shown in Figure 2, the first heat exchanger 10 according to this embodiment is equipped with a plate fin type first heat exchange section 3. The plate fin type first heat exchange section 3 is a heat exchange section having a structure in which multiple layers are arranged in stacks, each layer being provided with a planar (layered) first flow channel section 11a and each layer being provided with a second flow channel section 11b and a third flow channel section 11c.

[0044] The first heat exchange section 3 has a planar (flat plate) structure including fin sections 12 that constitute individual flow channels and side bars 13 that constitute the outer circumferential wall of the fin sections 12. An intermediate bar 14 is provided at an intermediate position in the side bars 13 of the layer in which the second flow channel section 11b and the third flow channel section 11c are provided. The shape of the fin sections 12 can vary, but Figure 2 shows an example in which the fin sections 12 are corrugated fins.

[0045] The layer in which the first flow channel 11a is provided does not have an intermediate bar 14. That is, the side bar 13 of the layer in which the first flow channel 11a is provided is provided so as to close off the outer circumference of the first flow channel 11a, excluding the inlet and outlet of the first flow channel 11a. In addition, each first flow channel 11a is partitioned by plates 15, which are partition walls on both sides in direction A. In other words, the first flow channel 11a is a space partitioned by the fin portion 12, the side bar 13, and the plates 15. Headers (not shown) are attached to the inlet and outlet of the first flow channel 11a, and fluid enters and exits each first flow channel 11a through the headers. The header attached to one side of the first flow channel 11a is connected to the high-temperature side inlet 3a (see Figure 4), which will be described later. The header attached to the other side of the first flow channel 11a is connected to the high-temperature side outlet 3b (see Figure 4), which will be described later. The plate 15 and the fin portion 12 function as heat transfer surfaces that transmit heat within the first heat exchange section 3. Direction A is the direction in which the first flow channel 11a, the second flow channel 11b, and the third flow channel 11c are stacked. Direction B is defined as the direction perpendicular to direction A, and two mutually perpendicular directions within direction B are defined as directions B1 and B2.

[0046] The side bars 13 and intermediate bars 14 are provided to block the outer periphery of the second flow channel 11b, excluding the inlet and outlet. Each second flow channel 11b is partitioned by plates 15, which are partition walls on both sides in direction A. In other words, the second flow channel 11b is a space partitioned by the fin section 12, side bars 13, intermediate bars 14, and plates 15. Headers (not shown) are attached to the inlet and outlet of the second flow channel 11b, and fluid enters and exits each second flow channel 11b through these headers. The header attached to one side of the second flow channel 11b is connected to the first low-temperature side inlet 3c (see Figure 4), which will be described later. The header attached to the other side of the second flow channel 11b is connected to the first low-temperature side outlet 3d (see Figure 4), which will be described later.

[0047] The configuration of the third flow channel section 11c is the same as that of the second flow channel section 11b. That is, the third flow channel section 11c is a space partitioned by the fin section 12, side bar 13, intermediate bar 14, and plate 15. Headers (not shown) are attached to the inlet and outlet of the third flow channel section 11c, and fluid enters and exits each third flow channel section 11c through the headers. The header attached to one side of the third flow channel section 11c is connected to the second low-temperature side inlet 3e (see Figure 4), which will be described later. The header attached to the other side of the third flow channel section 11c is connected to the second low-temperature side outlet 3f (see Figure 4), which will be described later.

[0048] Furthermore, a pair of end plates 16 are provided on the outermost surfaces (top and bottom) of each flow path in direction A. Each first flow path section 11a is formed in a rectangular shape when viewed from above. Each second flow path section 11b is also formed in a rectangular shape when viewed from above. Each third flow path section 11c is also formed in a rectangular shape when viewed from above. The sum of the lengths of the second flow path section 11b and the third flow path section 11c in direction B2 is equal to the length of the first flow path section 11a in direction B1. Therefore, the first heat exchange section 3 as a whole is formed in the shape of a rectangular box (cuboid).

[0049] Multiple first flow channels 11a are connected to a high-temperature flow channel 2 (see Figure 1) and allow high-temperature fluid 81 (see Figure 1) to flow through them. Multiple second flow channels 11b are connected to a second low-temperature flow channel 1b (see Figure 1) and a third low-temperature flow channel 1c and allow low-temperature fluid 80 (see Figure 1) to flow through them. Multiple third flow channels 11c are connected to a fourth low-temperature flow channel 1d (see Figure 1) and a fifth low-temperature flow channel 1e and allow low-temperature fluid 80 at a different temperature from the low-temperature fluid 80 flowing through the second flow channel 11b to flow through them. The first heat exchanger 3 facilitates heat exchange between the high-temperature fluid 81 flowing through the first flow channels 11a, the low-temperature fluid 80 flowing through the second flow channels 11b, and the low-temperature fluid 80 flowing through the third flow channels 11c. In this embodiment, the first heat exchange section 3 performs heat exchange in a 1:2 relationship between the high-temperature fluid 81 flowing through the first flow channel 11a, the low-temperature fluid 80 flowing through the second flow channel 11b, and the low-temperature fluid 80 flowing through the third flow channel 11c. Figure 2 shows an example of a direct-to-alternating current type heat exchanger where the flow direction of the low-temperature fluid 80 (see Figure 1) and the flow direction of the high-temperature fluid 81 (see Figure 1) are perpendicular in direction B. The first heat exchanger 10 may be a parallel flow type where the flow direction of the low-temperature fluid 80 and the flow direction of the high-temperature fluid 81 are in the same direction, or a counter-flow type where the flow direction of the low-temperature fluid 80 and the flow direction of the high-temperature fluid 81 are in opposite directions.

[0050] (Second heat exchanger) Next, the second heat exchanger 20 will be described with reference to Figure 3. As shown in Figure 3, the second heat exchanger 20 according to this embodiment is equipped with a plate fin type second heat exchange section 4. The plate fin type second heat exchange section 4 is a heat exchange section having a structure in which multiple layers are arranged in stacks, each layer being provided with a planar (layered) first flow channel section 21a and each layer being provided with a second flow channel section 21b.

[0051] The second heat exchange section 4 has a planar (flat plate) structure that includes fin sections 22 that constitute individual flow paths (channels) and side bars 23 that constitute the outer circumferential wall of the fin sections 22. The shape of the fin sections 22 can vary, but Figure 3 shows an example in which the fin sections 22 are corrugated fins.

[0052] The side bars 23 are provided to block the outer periphery of the first flow channel 21a, except for the inlet or outlet of the first flow channel 21a. In addition, each first flow channel 21a is partitioned by plates 24, which are partition walls on both sides in direction A. In other words, the first flow channel 21a is a space partitioned by the fin portion 22, the side bars 23, and the plates 24. Headers (not shown) are attached to the inlet and outlet of the first flow channel 21a, and fluid enters and exits each first flow channel 21a through the headers.

[0053] Furthermore, the side bars 23 are provided to block the outer periphery of the second flow channel 21b, except for the inlet or outlet of the second flow channel 21b. In addition, each second flow channel 21b is partitioned by plates 24, which are partition walls on both sides in direction A. In other words, the second flow channel 21b is a space partitioned by the fin section 22, the side bars 23, and the plates 24. Headers (not shown) are attached to the inlet and outlet of the second flow channel 21b, and fluid enters and exits each second flow channel 21b through the headers. The plates 24 and the fin section 22 function as heat transfer surfaces that transmit heat within the second heat exchange section 4.

[0054] Furthermore, a pair of end plates 25 are provided on the outermost surfaces (top and bottom) of each flow path in direction A. Each first flow path section 21a is formed in a rectangular shape when viewed from above. Similarly, each second flow path section 21b is formed in a rectangular shape when viewed from above. Therefore, the second heat exchange section 4 as a whole is formed in the shape of a rectangular box (cuboid).

[0055] Multiple first flow channels 21a are connected to a first low-temperature flow channel 1a (see Figure 1) and a second low-temperature flow channel 1b, and allow low-temperature fluid 80 (see Figure 1) to flow through them. Multiple second flow channels 21b are connected to a third low-temperature flow channel 1c (see Figure 1) and a fourth low-temperature flow channel 1d, and allow low-temperature fluid 80 with a different temperature from that of the first flow channels 21a to flow through them. The second heat exchanger 4 causes heat exchange between the low-temperature fluid 80 flowing through the first flow channels 21a and the low-temperature fluid 80 flowing through the second flow channels 21b. Figure 3 shows an example of a DC-AC type heat exchanger where the direction in which the first flow channels 21a extend and the direction in which the second flow channels 21b extend are perpendicular in direction B. The second heat exchanger 20 may be a parallel flow type in which the direction in which the first flow channel 21a extends and the direction in which the second flow channel 21b extends are the same, or a counter-flow type in which the direction in which the first flow channel 21a extends and the direction in which the second flow channel 21b extends are in opposite directions.

[0056] Here, the low-temperature fluid tank 5 (see Figure 1) stores low-temperature fluid 80 (see Figure 1), which is liquid hydrogen. The temperature of the liquid hydrogen is approximately -250°C. On the other hand, the temperature of the high-temperature fluid 81 (see Figure 1) stored in the high-temperature fluid tank 30 (see Figure 1) is, for example, 50°C to 60°C. Therefore, if the heat exchange system 100 does not have a heating section (first heat exchange section 3), when heat exchange is performed between the low-temperature fluid 80 flowing out of the low-temperature fluid tank 5 and the high-temperature fluid 81 flowing out of the high-temperature fluid tank 30, there is a risk that the liquid high-temperature fluid 81 will freeze. If the liquid high-temperature fluid 81 freezes, the flow rate of the high-temperature fluid 81 circulating in the high-temperature flow path 2 (see Figure 1) will decrease, and the efficiency of heat exchange between the low-temperature fluid 80 and the high-temperature fluid 81 will decrease.

[0057] (Heat exchange in the first heat exchange section and the second heat exchange section) Therefore, in this embodiment, before heat exchange between the low-temperature fluid 80 (see Figure 1) and the high-temperature fluid 81 (see Figure 1) takes place in the first heat exchange section 3 (see Figure 1), the second heat exchange section 4 is configured to perform heat exchange between the low-temperature fluids 80.

[0058] The heat exchange of each fluid in the first heat exchange section 3 and the second heat exchange section 4 will be explained with reference to Figures 4 and 5. In the example shown in Figure 4, the same diagram is used to illustrate the mutually communicating inlets and outlets of the first heat exchange section 3 and the second heat exchange section 4 in order to easily understand the connections between them.

[0059] (Connection between the first and second heat exchange sections) First, with reference to Figure 4, the connection between the first heat exchange section 3 and the second heat exchange section 4 will be explained. As shown in Figure 4, the second heat exchange section 4 includes a first inlet 4a into which the low-temperature fluid 80 (see Figure 1) flows in, a first outlet 4b which communicates with the first inlet 4a and from which the low-temperature fluid 80 that flowed in from the first inlet 4a after heat exchange flows out, a second inlet 4c into which the low-temperature fluid 80 that has flowed out from the first outlet 4b and passed through the first heat exchanger 10 (second flow path section 11b) flows in, and a second outlet 4d which communicates with the second inlet 4c and from which the low-temperature fluid 80 that flowed in from the second inlet 4c after heat exchange flows out. In other words, the second heat exchange section 4 is configured to exchange heat between the low-temperature fluid 80 that flows in from the first inlet 4a and the low-temperature fluid 80 that flows in from the second inlet 4c. The first inlet 4a and the first outlet 4b are connected by the first flow path section 21a. Furthermore, the second inlet 4c and the second outlet 4d are connected by the second flow channel section 21b.

[0060] In the example shown in Figure 4, for convenience, the first entrance 4a, the first exit 4b, the second entrance 4c, and the second exit 4d are each depicted with different shapes. Specifically, the first entrance 4a is marked with a dashed circle, the first exit 4b with a solid circle, the second entrance 4c with a solid triangle, and the second exit 4d with a solid square.

[0061] As shown in Figure 4, the first heat exchange section 3 includes a high-temperature side inlet 3a into which the high-temperature fluid 81 (see Figure 1) flows, and a high-temperature side outlet 3b that communicates with the high-temperature side inlet 3a. The high-temperature side inlet 3a and the high-temperature side outlet 3b are connected by a first flow path section 11a. The high-temperature fluid 81 flowing from the high-temperature fluid tank 30 (see Figure 1) into the first heat exchange section 3 flows into the first heat exchange section 3 via the high-temperature side inlet 3a. The high-temperature fluid 81 that has flowed into the first heat exchange section 3 flows out of the first heat exchange section 3 via the high-temperature side outlet 3b. In the example shown in Figure 4, for convenience, the high-temperature side inlet 3a and the high-temperature side outlet 3b are marked with solid double circles.

[0062] Furthermore, the first heat exchange section 3 includes a first low-temperature side inlet 3c into which a low-temperature fluid 80, which communicates with the first outlet 4b of the second heat exchange section 4, flows, and a first low-temperature side outlet 3d, which communicates with the first low-temperature side inlet 3c. The first low-temperature side inlet 3c and the first low-temperature side outlet 3d are connected by a second flow path section 11b.

[0063] Furthermore, in this embodiment, the first heat exchange section 3 includes a second low-temperature side inlet 3e communicating with the second outlet 4d of the second heat exchange section 4, and a second low-temperature side outlet 3f communicating with the second low-temperature side inlet 3e. That is, the first heat exchange section 3 (heating section) is provided between the first outlet 4b and the second inlet 4c. The second low-temperature side inlet 3e and the second low-temperature side outlet 3f are connected by a third flow path section 11c. The first low-temperature side inlet 3c, the first low-temperature side outlet 3d, the second low-temperature side inlet 3e, and the second low-temperature side outlet 3f included in the first heat exchange section 3 are marked with figures corresponding to the inlets and outlets of the second heat exchange section 4 to which they are connected.

[0064] The first inlet 4a of the second heat exchange section 4, indicated by the dashed circle, is connected to the cryogenic fluid tank 5 (see Figure 1) by the cryogenic flow path 1. Specifically, the first inlet 4a is connected to the cryogenic fluid tank 5 by the first cryogenic flow path section 1a.

[0065] Furthermore, the first outlet 4b of the second heat exchange section 4 is in communication with the first low-temperature side inlet 3c of the first heat exchange section 3. Specifically, the first outlet 4b is in communication with the first low-temperature side inlet 3c by the second low-temperature flow path section 1b. Therefore, the low-temperature fluid 80 flowing out from the first outlet 4b flows into the first heat exchange section 3 from the first low-temperature side inlet 3c. In the example shown in Figure 4, the first outlet 4b and the first low-temperature side inlet 3c are indicated by solid circles.

[0066] Furthermore, the first low-temperature outlet 3d of the first heat exchange section 3 is in communication with the second inlet 4c of the second heat exchange section 4. Specifically, the first low-temperature outlet 3d is in communication with the second inlet 4c via the third low-temperature flow path section 1c. Therefore, the low-temperature fluid 80 that flows out from the first low-temperature outlet 3d flows through the third low-temperature flow path section 1c and flows back into the second heat exchange section 4 from the second inlet 4c. In the example shown in Figure 4, the first low-temperature outlet 3d and the second inlet 4c are marked with solid triangles.

[0067] The second outlet 4d of the second heat exchange section 4 is in communication with the second low-temperature side inlet 3e of the first heat exchange section 3. Specifically, the second outlet 4d is in communication with the second low-temperature side inlet 3e by the fourth low-temperature flow path section 1d. Therefore, the low-temperature fluid 80 that flows out from the second outlet 4d of the second heat exchange section 4 flows into the first heat exchange section 3 from the second low-temperature side inlet 3e of the first heat exchange section 3. In the example shown in Figure 4, the second outlet 4d and the second low-temperature side inlet 3e are marked with solid rectangles.

[0068] The second low-temperature outlet 3f, indicated by the dashed circle, is connected to the low-temperature fluid storage section 7 (see Figure 1) by the low-temperature flow path 1. Specifically, the second low-temperature outlet 3f is connected to the low-temperature fluid storage section 7 by the fifth low-temperature flow path section 1e.

[0069] Therefore, the cryogenic fluid 80 (see Figure 1) stored in the cryogenic fluid tank 5 (see Figure 1) flows through the first cryogenic flow channel 1a, the first flow channel 21a, the second cryogenic flow channel 1b, the second flow channel 11b, the third cryogenic flow channel 1c, the second flow channel 21b, the fourth cryogenic flow channel 1d, the third flow channel 11c, and the fifth cryogenic flow channel 1e in that order, and flows into the cryogenic fluid storage section 7.

[0070] Furthermore, the high-temperature fluid tank 30 (see Figure 1) is connected to the first heat exchange unit 3 via the high-temperature flow path 2. Specifically, the high-temperature fluid tank 30 is connected to the first heat exchange unit 3 by the first high-temperature flow path 2a.

[0071] Furthermore, the high-temperature outlet 3b of the first heat exchange section 3 is connected to the second high-temperature flow path section 2b. Therefore, the high-temperature fluid 81 (see Figure 1) that flows from the high-temperature fluid tank 30 through the first high-temperature flow path section 2a flows in from the high-temperature inlet 3a, flows through the first flow path section 11a, flows out from the high-temperature outlet 3b, and flows through the second high-temperature flow path section 2b.

[0072] (Heat exchange of low-temperature fluids) Continuing with reference to Figure 4, the configuration in which the low-temperature fluid 80 (see Figure 1) performs heat exchange in each heat exchange section will be explained.

[0073] The cryogenic fluid 80 (see Figure 1) that flows from the cryogenic fluid tank 5 (Figure 1) into the cryogenic flow path 1 undergoes heat exchange in the order of 1 to 3, circled in Figure 4.

[0074] The first heat exchange (circled as number 1) takes place in the second heat exchange section 4. The low-temperature fluid 80 (see Figure 1) flowing into the second heat exchange section 4 from the low-temperature fluid tank 5 (Figure 1) exchanges heat with the low-temperature fluid 80 flowing out from the first heat exchange section 3. In other words, the first heat exchange takes place between the low-temperature fluid 80 flowing through the first flow channel 21a and the low-temperature fluid 80 flowing through the second flow channel 21b. To put it another way, the first heat exchange takes place between the low-temperature fluid 80 flowing in from the low-temperature fluid tank 5 and the low-temperature fluid 80 flowing out from the second heat exchange section 4 and re-entering the second heat exchange section 4 through self-circulation. The low-temperature fluid 80 flowing out from the first heat exchange section 3 exchanges heat with the high-temperature fluid 81 (see Figure 1) in the first heat exchange section 3. Therefore, the low-temperature fluid 80 flowing out from the first outlet 4b is at a higher temperature than the low-temperature fluid 80 flowing in from the first inlet 4a.

[0075] When the heat exchange system 100 is started, there is no low-temperature fluid 80 flowing from the second inlet 4c into the second heat exchange section 4. That is, at startup, the low-temperature fluid 80, which is liquid hydrogen at approximately -250°C, is not heated by the first heat exchange section 3 and flows into the second heat exchange section 4 in order to perform heat exchange with it. Therefore, when the heat exchange system 100 is started, no heat exchange occurs between the low-temperature fluids 80 as the first heat exchange. When the heat exchange system 100 is started, the second heat exchange section 4 is at room temperature. Therefore, when the heat exchange system 100 is started, the low-temperature fluid 80 flowing through the first flow channel 21a is heated by the heat capacity of the second heat exchange section 4. In this case, since the temperature difference between the second heat exchange section 4 and the low-temperature fluid 80 is large, the flow rate of the low-temperature fluid 80 flowing into the second heat exchange section 4 is reduced in order to suppress the thermal stress generated in the second heat exchange section 4. In other words, when the heat exchange system 100 is started, a small amount of low-temperature fluid 80 is circulated to heat the low-temperature fluid 80 using the heat capacity of the second heat exchange section 4, thereby driving the heat exchange system 100 in a preparation mode.

[0076] Next, the low-temperature fluid 80 undergoes a second heat exchange (circled as the second). This second heat exchange takes place in the first heat exchange section 3. Specifically, the second heat exchange occurs between the high-temperature fluid 81 (see Figure 1) flowing through the first flow path section 11a and the low-temperature fluid 80 flowing through the second flow path section 11b. That is, the low-temperature fluid 80, which has undergone heat exchange in the second heat exchange section 4 and flowed out from the second outlet 4d, flows into the first heat exchange section 3 and undergoes heat exchange with the high-temperature fluid 81. In other words, the first heat exchange section 3 (heating section) is configured to heat the low-temperature fluid 80 after it flows out from the first outlet 4b and before it flows into the second inlet 4c.

[0077] The low-temperature fluid 80 that has undergone the second heat exchange flows out from the first low-temperature side outlet 3d, circulates through the third low-temperature flow channel 1c, and flows back into the second heat exchange section 4 from the second inlet 4c. In other words, the low-temperature fluid 80 that flows out from the first outlet 4b exchanges heat with the high-temperature fluid 81 and then flows back into the second heat exchange section 4 from the second inlet 4c. The low-temperature fluid 80 that flows back into the second heat exchange section 4 from the second inlet 4c then exchanges heat with the low-temperature fluid 80 circulating through the first flow channel 21a as the high-temperature side fluid during the first heat exchange. In this embodiment, the low-temperature fluid 80 that flows out from the second outlet 4d is at a higher temperature than the low-temperature fluid 80 that flows out from the first outlet 4b. When heat exchange is performed between the low-temperature fluid 80 flowing out from the second outlet 4d and the low-temperature fluid 80 flowing in from the first inlet 4a, the temperature of each low-temperature fluid 80 after the heat exchange is expected to be around an intermediate temperature between the two. Furthermore, the temperature of the low-temperature fluid 80 that flows out from the second outlet 4d may be lower than the temperature of the low-temperature fluid 80 that flows out from the first outlet 4b.

[0078] Next, the low-temperature fluid 80 (see Figure 1) undergoes the third heat exchange (circled as the third). This third heat exchange takes place in the first heat exchange section 3. Specifically, the third heat exchange occurs between the high-temperature fluid 81 (see Figure 1) flowing through the first flow channel 11a and the low-temperature fluid 80 flowing through the third flow channel 11c. That is, the low-temperature fluid 80, which has undergone heat exchange in the second heat exchange section 4 and flowed out from the second outlet 4d, flows into the first heat exchange section 3 and undergoes heat exchange with the high-temperature fluid 81.

[0079] In this embodiment, the second and third heat exchanges are each performed in the first heat exchange section 3. That is, the first heat exchange section 3 is configured to perform heat exchange between the high-temperature fluid 81 in the high-temperature flow path 2 and the low-temperature fluid 80 flowing in from the first low-temperature side inlet 3c of the first heat exchange section 3, and between the high-temperature fluid 81 in the high-temperature flow path 2 and the low-temperature fluid 80 flowing in from the second low-temperature side inlet 3e of the first heat exchange section 3. In other words, the first heat exchange section 3 is configured to perform heat exchange between three fluids: the high-temperature fluid 81 flowing through the first flow path section 11a, the low-temperature fluid 80 flowing through the second flow path section 11b, and the low-temperature fluid 80 flowing through the third flow path section 11c.

[0080] The low-temperature fluid 80, after the third heat exchange, flows out from the second low-temperature outlet 3f, circulates through the fifth low-temperature flow path 1e, and is stored in the low-temperature fluid storage section 7.

[0081] Next, with reference to Figure 5, the details of the heat exchange between the low-temperature fluid 80 (see Figure 1) and the high-temperature fluid 81 (see Figure 1) in each heat exchange section will be described.

[0082] Graph 70, shown in Figure 5, has heat quantity on the horizontal axis and temperature on the vertical axis. The solid arrows 40a to 40d in Graph 70 indicate the changes in temperature and heat quantity of the cryogenic fluid 80 (see Figure 1). Specifically, arrow 40a indicates the changes in temperature and heat quantity of the cryogenic fluid 80 flowing into the first inlet 4a (see Figure 4) and flowing out from the first outlet 4b (see Figure 4). Arrow 40b indicates the changes in temperature and heat quantity of the cryogenic fluid 80 flowing in from the second inlet 4c (see Figure 4) and flowing out from the second outlet 4d (see Figure 4). Arrow 40c indicates the changes in temperature and heat quantity of the cryogenic fluid 80 flowing in from the first cryogenic side inlet 3c and flowing out from the first cryogenic side outlet 3d. Arrow 40d indicates the changes in temperature and heat quantity of the cryogenic fluid 80 flowing in from the second cryogenic side inlet 3e and flowing out from the second cryogenic side outlet 3f.

[0083] Furthermore, the dashed arrows 50a and 50b in Graph 70 indicate the changes in temperature and heat quantity of the high-temperature fluid 81 (see Figure 1). Specifically, arrows 50a and 50b each indicate the changes in temperature and heat quantity of the high-temperature fluid 81 (see Figure 1) flowing in from the high-temperature side inlet 3a (see Figure 4) and flowing out from the high-temperature side outlet 3b (see Figure 4). Note that for arrows 40a to 40d, arrow 50a, and arrow 50b, the starting point indicates the temperature and heat quantity at the start of heat exchange, and the ending point indicates the temperature and heat quantity at the end of heat exchange.

[0084] Furthermore, region R1 in Graph 70 represents the heat exchange in the second heat exchange section 4 (see Figure 4), while regions R2 and R3 represent the heat exchange in the first heat exchange section 3 (see Figure 4). The heat exchange in regions R1 to R3 corresponds to the first to third heat exchanges circled in Figure 4, respectively.

[0085] As shown in region R1, in the second heat exchange section 4 (see Figure 4), heat exchange takes place between the low-temperature fluid 80 that flows in through the first inlet 4a (see Figure 4) and flows out through the first outlet 4b (see Figure 4), and the low-temperature fluid 80 that flows in through the second inlet 4c (see Figure 4) and flows out through the second outlet 4d (see Figure 4).

[0086] As a result, as shown by arrow 40a, the temperature of the cryogenic fluid 80 flowing into the first inlet 4a and flowing out from the first outlet 4b rises from temperature t1 to temperature t2. On the other hand, as shown by arrow 40b, the temperature of the cryogenic fluid 80 flowing in from the second inlet 4c and flowing out from the second outlet 4d falls from temperature t3 to temperature t4.

[0087] Furthermore, as shown in region R2, in the first heat exchange section 3 (see Figure 4), heat exchange takes place between the low-temperature fluid 80 that flows in from the first low-temperature side inlet 3c and flows out from the first low-temperature side outlet 3d, and the high-temperature fluid 81 that flows in from the high-temperature side inlet 3a and flows out from the high-temperature side outlet 3b. As a result, the temperature of the low-temperature fluid 80 that flows in from the first low-temperature side inlet 3c and flows out from the first low-temperature side outlet 3d rises from temperature t2 to temperature t3. On the other hand, the temperature of the high-temperature fluid 81 that flows in from the high-temperature side inlet 3a and flows out from the high-temperature side outlet 3b decreases from temperature T1 to temperature T2.

[0088] Comparing the temperature t1 at the starting point of arrow 40a with the temperature t2 at the starting point of arrow 40c, we can see that the temperature t2 at the starting point of arrow 40c is higher. That is, the temperature difference td2 between the temperature t2 at the starting point of arrow 40c and the temperature T1 at the starting point of arrow 50a is smaller than the temperature difference td1 between the temperature t1 at the starting point of arrow 40a and the temperature T1 at the starting point of arrow 50a. Therefore, the high-temperature fluid 81 is less likely to freeze compared to the case where the low-temperature fluid 80 is not preheated by the second heat exchanger 4.

[0089] Furthermore, as shown in region R3, in the first heat exchange section 3 (see Figure 4), heat exchange takes place between the low-temperature fluid 80 that flows in from the second low-temperature side inlet 3e and flows out from the second low-temperature side outlet 3f, and the high-temperature fluid 81 that flows in from the high-temperature side inlet 3a and flows out from the high-temperature side outlet 3b. As a result, the temperature of the low-temperature fluid 80 that flows in from the second low-temperature side inlet 3e and flows out from the second low-temperature side outlet 3f rises from temperature t4 to temperature t5. The temperature of the high-temperature fluid 81 that flows in from the high-temperature side inlet 3a and flows out from the high-temperature side outlet 3b decreases from temperature T1 to temperature T2.

[0090] Comparing the temperature t1 at the starting point of arrow 40a with the temperature t4 at the starting point of arrow 40d, we can see that the temperature t4 at the starting point of arrow 40d is higher. That is, the temperature difference td3 between the temperature t4 at the starting point of arrow 40d and the temperature T1 at the starting point of arrow 50b is smaller than the temperature difference td1 between the temperature t1 at the starting point of arrow 40a and the temperature T1 at the starting point of arrow 50b. Therefore, the high-temperature fluid 81 is less likely to freeze compared to the case where the low-temperature fluid 80 is not preheated by the second heat exchanger 4.

[0091] In the example shown in Figure 5, arrows 50a and 50b are shown separately, but it is not necessary to separate the high-temperature flow path 2 (see Figure 4) through which the high-temperature fluid 81 flows. The flow rate of the high-temperature fluid 81 flowing through the high-temperature flow path 2 should be set to a flow rate that can supply the sum of the heat amounts shown by arrows 50a and 50b.

[0092] Here, the cryogenic fluid 80 (see Figure 1) stored in the cryogenic fluid storage unit 7 (see Figure 1) is gaseous hydrogen (hydrogen gas) at room temperature (temperature t5). When the cryogenic fluid 80 is supplied to the supply target 90 (see Figure 1), the temperature of the cryogenic fluid 80 rises. The upper limit temperature of the cryogenic fluid 80 when supplied to the supply target 90 is predetermined for each supply target 90. Therefore, the supply unit 8 is configured to supply cryogenic fluid 80 at a desired temperature according to the supply target 90. Specifically, the supply unit 8 is configured to supply cryogenic fluid 80 that has been adjusted to a temperature different from the temperature of the cryogenic fluid 80 stored in the cryogenic fluid storage unit 7. For example, if the desired temperature is temperature t6, the supply unit 8 cools the room temperature (temperature t5) cryogenic fluid 80 stored in the cryogenic fluid storage unit 7 to a predetermined temperature (temperature t6). Room temperature (temperature t5) is, for example, 10°C, and temperature t6 is, for example, -40°C.

[0093] The supply unit 8 (see Figure 1) is configured to mix the low-temperature fluid 80 (see Figure 1) flowing in from the low-temperature fluid storage unit 7 (see Figure 1) with a low-temperature fluid 80 that flows in from the branched channel 9 (see Figure 1) and is colder than the low-temperature fluid 80 stored in the low-temperature fluid storage unit 7. Specifically, the supply unit 8 is configured to supply low-temperature fluid 80 at a predetermined temperature (temperature t6) by adjusting the flow rate of the low-temperature fluid 80 flowing in from the supply channel 8a and the flow rate of the low-temperature fluid 80 flowing in from the branched channel 9 by adjusting the first supply valve 8b (see Figure 1) and the second supply valve 8c (see Figure 1).

[0094] (Effects of this embodiment) In this embodiment, the following effects can be obtained.

[0095] In this embodiment, as described above, the heat exchange system 100 includes a first heat exchange section 3 that performs heat exchange between a low-temperature fluid 80, which is a low-temperature fluid, and a high-temperature fluid 81, which is a liquid at a higher temperature than the low-temperature fluid 80, and a second heat exchange section 4 that performs heat exchange between the low-temperature fluids 80. The second heat exchange section 4 includes a first inlet 4a into which the low-temperature fluid 80 flows in, a first outlet 4b that communicates with the first inlet 4a and out which the low-temperature fluid 80 that flowed in from the first inlet 4a after heat exchange flows out, a second inlet 4c into which the low-temperature fluid 80 that flowed out from the first outlet 4b flows in, and a second inlet 4c that communicates with the second inlet 4c and after heat exchange The system includes a second outlet 4d through which the low-temperature fluid 80 that flows in from the second inlet 4c flows out, and is configured to exchange heat between the low-temperature fluid 80 that flows in from the first inlet 4a and the low-temperature fluid 80 that flows in from the second inlet 4c. It is provided between the first outlet 4b and the second inlet 4c and includes a heating section that heats the low-temperature fluid 80 after it flows out from the first outlet 4b and before it flows into the second inlet 4c. The second outlet 4d is in communication with the first heat exchange section 3 and heat is exchanged by the second heat exchange section 4, and the low-temperature fluid 80 that flows out from the second outlet 4d flows into the first heat exchange section 3 and exchanges heat with the high-temperature fluid 81.

[0096] As a result, the low-temperature fluid 80 is heated by the second heat exchange section 4 before it flows into the first heat exchange section 3, thus preheating the low-temperature fluid 80 before it flows into the first heat exchange section 3. Therefore, compared to a configuration without the second heat exchange section 4, the temperature difference between the low-temperature fluid 80 and the high-temperature fluid 81 flowing into the first heat exchange section 3 can be reduced. Consequently, freezing of the high-temperature fluid 81 in the first heat exchange section 3 can be suppressed.

[0097] Furthermore, the first heat exchange section 3 also serves as a heating section. The first heat exchange section 3 includes a first low-temperature side inlet 3c into which the low-temperature fluid 80 flows, and a first low-temperature side outlet 3d that communicates with the first low-temperature side inlet 3c. The first outlet 4b of the second heat exchange section 4 communicates with the first low-temperature side inlet 3c of the first heat exchange section 3. The low-temperature fluid 80 that flows out from the first outlet 4b flows into the first heat exchange section 3 from the first low-temperature side inlet 3c, exchanges heat with the high-temperature fluid 81, and then flows back into the second heat exchange section 4 from the second inlet 4c. As a result, the low-temperature fluid 80 that flows out from the first outlet 4b is heated by the first heat exchange section 3 and returned to the second heat exchange section 4 from the second inlet 4c. Therefore, the low-temperature fluid 80 flowing in from the second inlet 4c can be heated without providing a heater or the like to heat the low-temperature fluid 80 that flows out from the first outlet 4b. As a result, compared to a configuration that includes a heater or the like to heat the low-temperature fluid 80 that flows out from the first outlet 4b, it is possible to suppress the increase in size of the heat exchange system 100.

[0098] Furthermore, in this case, the low-temperature fluid 80 flowing out from the first outlet 4b is at a higher temperature than the low-temperature fluid 80 flowing in from the first inlet 4a, and the low-temperature fluid 80 flowing out from the second outlet 4d is at a higher temperature than the low-temperature fluid 80 flowing in from the first inlet 4a. In other words, both the low-temperature fluid 80 flowing out from the first outlet 4b and flowing into the first heat exchange section 3, and the low-temperature fluid 80 flowing out from the second outlet 4d and flowing into the first heat exchange section 3, enter the first heat exchange section 3 at a higher temperature than the low-temperature fluid 80 flowing in from the first inlet 4a. Therefore, compared to a configuration in which the low-temperature fluid 80 flows directly into the first heat exchange section 3 without passing through the second heat exchange section 4, the temperature difference between the low-temperature fluid 80 and the high-temperature fluid 81 can be reduced. As a result, compared to a configuration in which the low-temperature fluid 80 flows directly into the second heat exchange section 4 without passing through the second heat exchange section 4, freezing of the high-temperature fluid 81 can be suppressed.

[0099] Furthermore, the first heat exchange section 3 further includes a second low-temperature side inlet 3e communicating with the second outlet 4d of the second heat exchange section 4, and a second low-temperature side outlet 3f communicating with the second low-temperature side inlet 3e. The low-temperature fluid 80 that flows out from the second outlet 4d of the second heat exchange section 4 flows into the first heat exchange section 3 from the second low-temperature side inlet 3e of the first heat exchange section 3 and exchanges heat with the high-temperature fluid 81. As a result, the second low-temperature side inlet 3e of the first heat exchange section 3 and the second outlet 4d of the second heat exchange section 4 are in communication, so the low-temperature fluid 80 that has undergone heat exchange in the second heat exchange section 4 can be easily introduced into the first heat exchange section 3. Consequently, a fluid circuit can be easily formed that allows the low-temperature fluid 80 to flow into the first heat exchange section 3 after being preheated by the second heat exchange section 4.

[0100] Furthermore, the first heat exchange unit 3 is configured to perform heat exchange between the high-temperature fluid 81 in the high-temperature flow path 2 and the low-temperature fluid 80 flowing in from the first low-temperature side inlet 3c of the first heat exchange unit 3, and between the high-temperature fluid 81 in the high-temperature flow path 2 and the low-temperature fluid 80 flowing in from the second low-temperature side inlet 3e of the first heat exchange unit 3. This allows the first heat exchange unit 3 to perform heat exchange between the three fluids: the high-temperature fluid 81, the low-temperature fluid 80 flowing in from the first low-temperature side inlet 3c, and the low-temperature fluid 80 flowing in from the second low-temperature side inlet 3e. As a result, compared to a configuration that includes a heat exchange unit that performs heat exchange between the high-temperature fluid 81 and the low-temperature fluid 80 flowing in from the first low-temperature side inlet 3c, and a heat exchange unit that performs heat exchange between the high-temperature fluid 81 and the low-temperature fluid 80 flowing in from the second low-temperature side inlet 3e, it is possible to suppress an increase in the number of parts and an increase in structural complexity.

[0101] Furthermore, the first heat exchange section 3 and the second heat exchange section 4 are provided in different first heat exchangers 10 and second heat exchangers 20, respectively. This makes it easy to form a fluid circuit in which the temperature of the low-temperature fluid 80 flowing into the first heat exchange section 3 can be preheated by the second heat exchange section 4 by connecting the first heat exchanger 10 equipped with the first heat exchange section 3 and the second heat exchanger 20 equipped with the second heat exchange section 4. As a result, for example, the complexity of the heat exchanger piping installation can be suppressed compared to a heat exchanger equipped with both the first heat exchange section 3 and the second heat exchange section 4.

[0102] Furthermore, in a configuration where the temperature is higher than the low-temperature fluid 80 flowing in from the first inlet 4a, preferably the system further comprises a low-temperature fluid tank 5 for storing liquid low-temperature fluid 80, a low-temperature fluid pump 6 for circulating the low-temperature fluid 80 stored in the low-temperature fluid tank 5 through the low-temperature flow path 1, a low-temperature fluid storage section 7 for storing the low-temperature fluid 80 that has been heated by the first heat exchange section 3 and vaporized, a supply section 8 connected to the low-temperature fluid storage section 7 for supplying the vaporized low-temperature fluid 80 to the target 90, and a branch flow path 9 that branches off from the low-temperature flow path 1 and connects to the supply section 8 for circulating the low-temperature fluid 80, wherein the supply section 8 is configured to mix the low-temperature fluid 80 flowing in from the low-temperature fluid storage section 7 with the low-temperature fluid 80 flowing in from the branch flow path 9 and which is colder than the low-temperature fluid 80 stored in the low-temperature fluid storage section 7. This allows the temperature of the low-temperature fluid 80 stored in the low-temperature fluid storage section 7 to be easily lowered when providing it to the target recipient 90 by mixing the low-temperature fluid 80 stored in the low-temperature fluid storage section 7 with the low-temperature fluid 80 flowing in from the branch channel 9. Therefore, the temperature of the low-temperature fluid 80 stored in the storage section can be lowered to the temperature at which it will be provided to the target recipient without using a refrigerator or the like. As a result, the system can be kept from becoming oversized compared to a configuration that includes a refrigerator or the like to lower the temperature of the low-temperature fluid 80 stored in the low-temperature fluid storage section 7.

[0103] Furthermore, the low-temperature fluid 80 is liquid hydrogen, and the high-temperature fluid 81 is hot water. This makes it possible to provide a heat exchange system 100 that can suppress the freezing of the hot water when heat exchange is performed between the liquid hydrogen, which is the low-temperature fluid 80, and the hot water, which is the high-temperature fluid 81.

[0104] (modified version) It should be noted that the embodiments and modifications disclosed herein are illustrative and not restrictive in all respects. The scope of the present invention is defined by the claims rather than by the descriptions of the embodiments and modifications described above, and further includes all modifications (modifications) within the meaning and scope equivalent to the claims.

[0105] For example, in the above embodiment, an example configuration was shown in which the first heat exchange unit 3 is provided in the first heat exchanger 10 and the second heat exchange unit 4 is provided in the second heat exchanger 20, but the present invention is not limited thereto. In the present invention, as shown in the modified heat exchange system 200 in Figure 6, the first heat exchange unit 3 and the second heat exchange unit 4 may be provided in a single heat exchanger 210.

[0106] Furthermore, in the above embodiment, an example was shown in which the heat exchange system 100 is configured such that the cryogenic fluid 80 stored in the cryogenic fluid tank 5 is pressurized to a predetermined pressure by the cryogenic fluid pump 6 and vaporized by the first heat exchange section 3 and the second heat exchange section 4. However, the present invention is not limited to this. In the present invention, the heat exchange system may be configured to pressurize the cryogenic fluid 80, which has been vaporized by the first heat exchange section 3 and the second heat exchange section 4, to a predetermined pressure and store it in the cryogenic fluid storage section 7.

[0107] Furthermore, although the above embodiment shows an example in which the first heat exchange unit 3 also serves as a heating unit, the present invention is not limited to this. For example, the low-temperature fluid 80 flowing out from the first outlet 4b and into the second inlet 4c does not need to be heated by the first heat exchange unit 3 (heating unit). In this case, a heating device such as a heater can be provided in the low-temperature flow path 1 between the first outlet 4b and the second inlet 4c to heat the low-temperature fluid 80. Alternatively, the low-temperature fluid 80 flowing into the second inlet 4c may be heated to a predetermined temperature by performing heat exchange between the low-temperature fluid 80 and air between the flowing out from the first outlet 4b and into the second inlet 4c. In this case, the first outlet 4b and the second inlet 4c should be connected by a low-temperature flow path 1 having a length (flow path length) that allows the low-temperature fluid 80 to be heated to a predetermined temperature by air. However, if a heating device such as a heater is provided between the first outlet 4b and the second inlet 4c, the system will become larger. Furthermore, in a configuration where heat exchange is performed between the low-temperature fluid 80 and air, the length of the low-temperature flow path 1 between the first outlet 4b and the second inlet 4c (flow path length) increases, resulting in a larger system. Therefore, it is preferable that the first heat exchange section 3 also functions as a heating section.

[0108] Furthermore, in the above embodiment, an example was shown in which the low-temperature fluid 80 flowing out from the second outlet 4d is at a higher temperature than the low-temperature fluid 80 flowing in from the first inlet 4a, and is also at a higher temperature than the low-temperature fluid 80 flowing out from the first outlet 4b. However, the present invention is not limited to this. As long as the temperature of the low-temperature fluid 80 flowing out from the second outlet 4d is higher than the temperature of the low-temperature fluid 80 flowing in from the first inlet 4a, it may be higher or lower than the temperature of the low-temperature fluid 80 flowing out from the first outlet 4b.

[0109] Furthermore, although the above embodiment shows an example in which the first heat exchange unit 3 includes a second low-temperature side inlet 3e and a second low-temperature side outlet 3f, the present invention is not limited to this. In the present invention, the first heat exchange unit 3 does not have to include a second low-temperature side inlet 3e and a second low-temperature side outlet 3f. That is, the first heat exchange unit 3 does not have to be configured to perform both heat exchange between the high-temperature fluid 81 and the low-temperature fluid 80 flowing in from the first low-temperature side inlet 3c, and heat exchange between the high-temperature fluid 81 and the low-temperature fluid 80 flowing in from the second low-temperature side inlet 3e. In this case, a separate heat exchanger can be provided to perform heat exchange between the low-temperature fluid 80 discharged from the second outlet 4d and the high-temperature fluid 81. However, if the first heat exchange unit 3 does not include a second low-temperature side inlet 3e and a second low-temperature side outlet 3f, a heat exchanger will have to be provided to perform heat exchange between the low-temperature fluid 80 discharged from the second outlet 4d and the high-temperature fluid 81, which will increase the size of the system. Therefore, it is preferable that the first heat exchange section 3 includes a second low-temperature side inlet 3e and a second low-temperature side outlet 3f.

[0110] Furthermore, although the above embodiment shows an example in which the heat exchange system 100 includes a low-temperature fluid storage section 7, the present invention is not limited thereto. In the present invention, the heat exchange system 100 does not need to include a low-temperature fluid storage section 7, as long as it includes a low-temperature fluid pump 6 capable of supplying a preset amount of low-temperature fluid 80 to a target supply 90.

[0111] Furthermore, although the above embodiment shows an example where the low-temperature fluid 80 is liquid hydrogen and the high-temperature fluid 81 is hot water, the present invention is not limited to this. The low-temperature fluid 80 may be liquid helium or liquefied natural gas. The high-temperature fluid 81 may be ethylene glycol.

[0112] Furthermore, although the above embodiment shows an example where the first heat exchange section 3 and the second heat exchange section 4 are of the plate fin type, the present invention is not limited thereto. In the present invention, the first heat exchange section 3 and the second heat exchange section 4 may be of any type. For example, the first heat exchange section 3 and the second heat exchange section 4 may be a diffusion-bonded type heat exchange section in which a plurality of heat transfer plates with groove-shaped flow channels are laminated and diffusion-bonded.

[0113] Furthermore, although the above embodiment shows an example in which the branched channel 9 branches off from the second low-temperature channel section 1b, the present invention is not limited thereto. The branched channel 9 may branch off from anywhere in the low-temperature channel 1, as long as it is a channel through which a low-temperature fluid 80 at a lower temperature than the low-temperature fluid 80 stored in the low-temperature fluid storage section 7 flows. In other words, the branched channel 9 may branch off from anywhere in the low-temperature channel 1, as long as it branches off from a location other than the fifth low-temperature channel section 1e. [Explanation of Symbols]

[0114] 1. Low-temperature channel 2 High temperature flow path 3 1st heat exchange section (heating section) 3c 1st low temperature side inlet 3d 1st low temperature side outlet 3e Second low-temperature inlet 3f 2nd low temperature side outlet 4 Second heat exchange section 4a Entrance 1 4b Exit 1 4c 2nd entrance 4d 2nd exit 5. Cryogenic fluid tank 6. Cryogenic fluid pump 7. Low-temperature fluid storage section 8 Supply section 9 branch channels 10 1st heat exchanger 20 Second heat exchanger 80 Cryogenic fluids 81 High temperature fluid 90 Target customers 100, 200 heat exchange systems

Claims

1. a first heat exchange unit that performs heat exchange between a low-temperature fluid, which is a low-temperature fluid, and a high-temperature fluid, which is higher in temperature than the low-temperature fluid; a second heat exchange unit that performs heat exchange between the low-temperature fluids, the second heat exchange unit includes a first inlet into which the low-temperature fluid flows in, a first outlet communicating with the first inlet and through which the low-temperature fluid that flows in from the first inlet flows out after heat exchange, a second inlet into which the low-temperature fluid that flows out from the first outlet flows in, and a second outlet communicating with the second inlet and through which the low-temperature fluid that flows in from the second inlet flows out after heat exchange, and is configured to exchange heat between the low-temperature fluid that flows in from the first inlet and the low-temperature fluid that flows in from the second inlet, the first heat exchange unit is provided between the first outlet and the second inlet, and also serves as a heating unit that heats the low-temperature fluid after it flows out of the first outlet and before it flows into the second inlet; The second outlet is in communication with the first heat exchange section, The low-temperature fluid that has been heat exchanged by the second heat exchange section and flowed out from the second outlet flows into the first heat exchange section and is heat exchanged with the high-temperature fluid.

2. The first heat exchange section includes a first low-temperature side inlet into which the low-temperature fluid flows, and a first low-temperature side outlet communicating with the first low-temperature side inlet; the first outlet of the second heat exchanger is in communication with the first low-temperature side inlet of the first heat exchanger, 2. The heat exchange system according to claim 1, wherein the low-temperature fluid flowing out from the first outlet flows into the first heat exchange section from the first low-temperature side inlet, exchanges heat with the high-temperature fluid, and then flows back into the second heat exchange section from the second inlet.

3. the first heat exchange section further includes a second low-temperature side inlet communicating with the second outlet of the second heat exchange section and a second low-temperature side outlet communicating with the second low-temperature side inlet, 3. The heat exchange system according to claim 2, wherein the low-temperature fluid flowing out from the second outlet of the second heat exchange section flows into the first heat exchange section from the second low-temperature side inlet of the first heat exchange section and is heat exchanged with the high-temperature fluid.

4. 4. The heat exchange system according to claim 3, wherein the first heat exchange section is configured to perform heat exchange between the high-temperature fluid and the low-temperature fluid flowing in from the first low-temperature side inlet of the first heat exchange section, and to perform heat exchange between the high-temperature fluid and the low-temperature fluid flowing in from the second low-temperature side inlet of the first heat exchange section.

5. The heat exchange system according to claim 3 , wherein the first heat exchange section and the second heat exchange section are provided in different first and second heat exchangers, respectively.

6. a cryogenic fluid tank for storing the liquid cryogenic fluid; a cryogenic fluid pump that circulates the cryogenic fluid stored in the cryogenic fluid tank through a cryogenic flow path that circulates the cryogenic fluid; a cryogenic fluid storage section that stores the cryogenic fluid that has been heated and vaporized by the first heat exchange section; a supply unit connected to the cryogenic fluid storage unit and supplying the vaporized cryogenic fluid to a supply target; a branch flow path that branches off from the low-temperature flow path, connects to the supply unit, and allows the low-temperature fluid to flow through; The heat exchange system according to claim 5, wherein the supply unit is configured to mix the low-temperature fluid flowing in from the low-temperature fluid storage unit with the low-temperature fluid flowing in from the branch flow path and having a lower temperature than the low-temperature fluid stored in the low-temperature fluid storage unit.

7. the cryogenic fluid is liquid hydrogen; The heat exchange system according to any one of claims 1 to 6, wherein the high-temperature fluid is hot water.

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