Intermediate medium heat exchanger

Abstract

The intermediate medium heat exchanger comprises an intermediate medium evaporator, a liquefied gas vaporizer, and a communicating pipe having a multi-layered tube structure with inner and outer tubes. An intermediate medium is enclosed within the space of the intermediate medium heat exchanger. When one of the space inside the inner tube and the space between the inner and outer tubes is defined as a first flow path, and the other as a second flow path, the first flow path has a first upper opening and a first lower opening, functioning as a gas flow path through which the gaseous intermediate medium flows. The second flow path has a second upper opening and a second lower opening, and when at least a portion of the space is filled with the liquid intermediate medium, functions as a liquid flow path through which the liquid intermediate medium flows.

Description

Technical Field

[0001] The present invention relates to an intermediate medium type heat exchanger. Background Art

[0002] Conventionally, an intermediate medium heat exchanger for vaporizing cryogenic liquefied gas such as liquefied natural gas (LNG) is known, as disclosed in Patent Document 1. The intermediate medium heat exchanger transfers heat from a heat source medium to the cryogenic liquefied gas through the intermediate medium while circulating the intermediate medium.

[0003] The intermediate medium type heat exchanger disclosed in Patent Document 1 is as follows Figure 19 As shown, the structure includes a chamber 80 as a box body for the intermediate medium, heat transfer pipes 88 and 93, and includes an intermediate medium evaporation section 81 and an LNG vaporization section 82.

[0004] Specifically, the intermediate medium evaporator 81 includes a lower portion 80b of the chamber 80 and a straight heat transfer tube 88 connected to the lower portion 80b. The LNG vaporizer 82 includes an upper portion 80t of the chamber 80 and a U-shaped heat transfer tube 93 connected to the upper portion 80t. The lower portion 80b and the upper portion 80t form a single chamber 80. The intermediate medium is enclosed in the chamber 80. Seawater, serving as a heat source medium, flows through the heat transfer tube 88. LNG flows through the heat transfer tube 93. The intermediate medium accumulated in the chamber 80 is heated by the seawater via the heat transfer tube 88 and becomes a gaseous intermediate medium GM. This gaseous intermediate medium GM is cooled by the LNG via the heat transfer tube 93 and becomes a liquid intermediate medium LM. In this manner, the intermediate medium circulates in the chamber 80 while undergoing phase conversion between gas and liquid.

[0005] The intermediate medium heat exchanger comprises a chamber 80 serving as a housing for storing the intermediate medium, a heat transfer tube 88 connected to the upper portion 80t thereof, and a heat transfer tube 93 connected to the lower portion 80b thereof. Therefore, the intermediate medium heat exchanger cannot be manufactured using a common shell-and-tube heat exchanger and requires specialized design and manufacturing, which increases costs.

[0006] Patent Literature

[0007] Patent Document 1: Japanese Patent Application Laid-Open No. 2017-120125. Summary of the Invention

[0008] An object of the present invention is to provide an intermediate medium heat exchanger capable of suppressing costs.

[0009] An intermediate medium heat exchanger according to one embodiment of the present invention comprises: an intermediate medium evaporator having a hollow first chamber and a first heat transfer tube arranged to pass through the first chamber and into which a heat source medium flows; a liquefied gas vaporizer having a hollow second chamber arranged above the first chamber and a second heat transfer tube arranged to pass through the second chamber and into which a low-temperature liquefied gas flows; and a connecting tube having a multi-layered tube structure including an inner tube and an outer tube arranged radially outward of the inner tube, which connects the interior space of the first chamber and the interior space of the second chamber. An intermediate medium is enclosed in the space formed by the first chamber, the second chamber, and the connecting tube. The liquid intermediate medium in the first chamber is heated by the heat source medium via the first heat transfer tube and vaporized to become a gaseous intermediate medium. The gaseous intermediate medium in the second chamber is cooled by the low-temperature liquefied gas via the second heat transfer tube and condensed to become a liquid intermediate medium. Furthermore, when one of the space inside the inner tube and the space between the inner tube and the outer tube serves as the first flow path and the other serves as the second flow path, the first flow path includes a first upper opening portion opening above the liquid level of the liquid intermediate medium in the second chamber and a first lower opening portion opening above the liquid level of the liquid intermediate medium in the first chamber, and functions as a gas flow path through which the gaseous intermediate medium flows. The second flow path includes a second upper opening portion opening below the liquid level of the liquid intermediate medium in the second chamber and a second lower opening opening in the first chamber, and functions as a liquid flow path through which the liquid intermediate medium flows, with at least a portion of the space filled with the liquid intermediate medium. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 It is a front cross-sectional view showing the intermediate medium heat exchanger according to the first embodiment.

[0011] Figure 2 is a side sectional view showing the intermediate medium type heat exchanger according to the first embodiment. Figure 1 Cross-sectional view at line II-II in .

[0012] Figure 3 It is a side cross-sectional view showing an intermediate medium heat exchanger according to a first modified example of the first embodiment.

[0013] Figure 4 It is a side cross-sectional view showing an intermediate medium heat exchanger according to a second modified example of the first embodiment.

[0014] Figure 5 It is a side cross-sectional view showing an intermediate medium heat exchanger according to a third modified example of the first embodiment.

[0015] Figure 6 It is a side cross-sectional view showing an intermediate medium heat exchanger according to a fourth modified example of the first embodiment.

[0016] Figure 7 It is a side cross-sectional view showing an intermediate medium heat exchanger according to a fifth modified example of the first embodiment.

[0017] Figure 8 It is a side cross-sectional view of an intermediate medium heat exchanger showing a sixth modified example of the first embodiment.

[0018] Figure 9 It is a front cross-sectional view of an intermediate medium heat exchanger showing a seventh modified example of the first embodiment.

[0019] Figure 10 It is a front cross-sectional view showing an intermediate medium heat exchanger according to an eighth modified example of the first embodiment.

[0020] Figure 11 It is enlarged to show Figure 10 Figure 1 of region XI.

[0021] Figure 12 It is a side cross-sectional view showing an intermediate medium heat exchanger according to a second embodiment.

[0022] Figure 13 It is a side cross-sectional view showing an intermediate medium heat exchanger according to a first modified example of the second embodiment.

[0023] Figure 14 It is a side cross-sectional view showing an intermediate medium heat exchanger according to a second modified example of the second embodiment.

[0024] Figure 15 It is a side cross-sectional view showing an intermediate medium heat exchanger according to a third modified example of the second embodiment.

[0025] Figure 16 It is a side cross-sectional view showing an intermediate medium heat exchanger according to a fourth modified example of the second embodiment.

[0026] Figure 17 It is a side cross-sectional view showing an intermediate medium heat exchanger according to a fifth modified example of the second embodiment.

[0027] Figure 18 It is a side cross-sectional view of an intermediate medium heat exchanger showing a sixth modified example of the second embodiment.

[0028] Figure 19 This is a front cross-sectional view showing a conventional intermediate medium heat exchanger. DETAILED DESCRIPTION

[0029] Hereinafter, the intermediate medium type heat exchanger according to the embodiment will be described. In the following description, except for the Figure 13 , Figure 15 The first and third modified examples of the second embodiment are described below assuming a radially symmetrical shape. The following embodiment is an example of embodying the present invention and is not intended to limit the scope of protection of the present invention.

[0030] (First embodiment)

[0031] An intermediate medium heat exchanger exchanges heat between a heat source medium and a cryogenic liquefied gas via an intermediate medium. While circulating the intermediate medium, the intermediate medium heat exchanger transfers heat from the heat source medium to liquefied natural gas (LNG) via the intermediate medium. This vaporizes the LNG, producing natural gas (NG). Intermediate medium heat exchangers are not limited to vaporizing LNG as cryogenic liquefied gas; for example, they can also vaporize ethylene, liquid oxygen, liquid nitrogen, or other gases. The heat source medium can be seawater, industrial water, or other materials.

[0032] like Figure 1 、 2 As shown, the intermediate medium heat exchanger 1 includes an intermediate medium evaporator E1, a liquefied gas vaporizer E2, a connecting pipe 30, and a liquid reservoir 40. The intermediate medium heat exchanger 1 has a closed space formed by the intermediate medium evaporator E1, the liquefied gas vaporizer E2, and the connecting pipe 30. Intermediate media LM and GM are enclosed in this space.

[0033] The intermediate medium evaporator E1 is a shell-and-tube heat exchanger. Specifically, it includes a hollow chamber (first chamber) 10c with its longitudinal side oriented horizontally, and a first heat transfer tube 10d arranged to pass through the first chamber 10c. In the intermediate medium evaporator E1, heat is exchanged between the heat source medium in the first heat transfer tube 10d and the liquid intermediate medium LM in the first chamber 10c. Heat from the heat source medium causes the liquid intermediate medium LM to evaporate, thereby generating a gaseous intermediate medium GM.

[0034] The first heat transfer tube 10d is as follows Figure 1 As shown, it has a straight tube shape and is arranged so as to pass through the lower side (bottom side) of the first chamber 10c. The first heat transfer tube 10d passes through the first chamber 10c along the longitudinal direction of the first chamber 10c. In addition, in the first heat transfer tube 10d, the heat source medium is Figure 1 Flowing into the left side, Figure 1 The heat transfer tube 10d flows out from the right side (i.e., from one side to the other side in the longitudinal direction). Figure 2 As shown, a plurality of first heat transfer tubes 10d are provided.

[0035] In the first chamber 10c, when the intermediate medium heat exchanger 1 is in operation, Figure 1 as well as Figure 2 As shown, liquid intermediate medium LM is stored. The first heat transfer tube 10d is immersed in the liquid intermediate medium LM stored in the first chamber 10c.

[0036] The liquefied gas vaporizer E2 is a shell-and-tube heat exchanger. Specifically, it includes a hollow chamber (second chamber) 20c, located above the first chamber 10c and with its longitudinal sides oriented horizontally, and a second heat transfer tube 20d, arranged to pass through the second chamber 20c. In the liquefied gas vaporizer E2, heat is exchanged between the gaseous intermediate medium GM in the second chamber 20c and the low-temperature liquefied gas in the second heat transfer tube 20d. The low-temperature liquefied gas is thus vaporized by the heat of the intermediate medium GM. At this point, the gaseous intermediate medium GM is cooled by the low-temperature liquefied gas, generating the liquid intermediate medium LM.

[0037] The second heat transfer tube 20d is as follows Figure 1 As shown, it has a U-shape and is configured to pass through the second chamber 20c at a distance from the bottom of the second chamber 20c. Specifically, one end of the second heat transfer tube 20d is connected to a side wall portion of the second chamber 20c in the long side direction and extends to the vicinity of the other side wall portion of the second chamber 20c in the long side direction. Moreover, the second heat transfer tube 20d is bent back near the other side wall portion in the long side direction, and its other end is connected to a side wall portion of the second chamber 20c in the long side direction. Figure 2 As shown, a plurality of second heat transfer tubes 20d are provided. In addition, the second heat transfer tube 20d is not limited to the case of having a U-shape, and can also be a straight tube. In addition, in this specification, "one side in the long side direction" refers to Figure 1 The left side of the “other side in the long direction” refers to Figure 1 on the right side.

[0038] In the second chamber 20c, when the intermediate medium heat exchanger 1 is in operation, Figure 1 as well as Figure 2 As shown, the gaseous intermediate medium GM and the liquid intermediate medium LM are stored. The second heat transfer tube 20d is arranged above and apart from the liquid intermediate medium LM stored in the second chamber 20c.

[0039] The connecting pipe 30 is as follows Figure 2 As shown, the tube has a double-tube structure including an inner tube 31 and an outer tube 32 arranged radially outside the inner tube 31. The connecting tube 30 connects the first chamber 10c and the second chamber 20c via the inner tube 31 and the outer tube 32.

[0040] The upper end of the outer tube 32 is connected to the bottom portion of the second chamber 20c, forming the lower surface, by welding, for example. The upper end of the outer tube 32 opens into the liquid intermediate medium LM stored in the second chamber 20c. The middle portion of the outer tube 32 is connected to the top portion of the first chamber 10c, forming the upper surface, by welding, for example. Furthermore, the outer tube 32 penetrates the top portion of the first chamber 10c. In other words, the lower end of the outer tube 32 extends into the first chamber 10c. The lower end of the outer tube 32 opens in the first chamber 10c at a position above the liquid level of the liquid intermediate medium LM stored in the first chamber 10c.

[0041] The inner tube 31 is arranged inside the outer tube 32, extending from the space within the first chamber 10c to the space within the second chamber 20c. Furthermore, the length of the inner tube 31 is set to be longer than that of the outer tube 32. The upper end of the inner tube 31 is positioned higher than the upper end of the outer tube 32 and higher than the liquid level of the liquid intermediate medium LM stored in the second chamber 20c. Therefore, the upper end of the inner tube 31 opens into the gaseous intermediate medium GM in the second chamber 20c. The lower end of the inner tube 31 is positioned lower than the lower end of the outer tube 32 and higher than the liquid level of the liquid intermediate medium LM stored in the first chamber 10c. Therefore, the lower end of the inner tube 31 opens into the gaseous intermediate medium GM in the first chamber 10c.

[0042] The communicating tube 30 forms spaces inside the inner tube 31 and between the inner tube 31 and the outer tube 32. In the first embodiment, the space inside the inner tube 31 is defined as the first flow path F1, and the space between the inner tube 31 and the outer tube 32 is defined as the second flow path F2.

[0043] The first flow path F1 includes a first upper opening F1b, which is an opening formed at the upper end of the inner tube 31, and a first lower opening F1a, which is an opening formed at the lower end of the inner tube 31. The first upper opening F1b is located above the liquid intermediate medium LM stored in the second chamber 20c. The first lower opening F1a is located below a second lower opening F2a, described later, and at a height between the second lower opening F2a and the liquid level of the liquid intermediate medium LM stored in the first chamber 10c.

[0044] The second flow path F2 includes a second upper opening F2b, an annular opening formed by the upper end of the outer tube 32 and the inner tube 31, and a second lower opening F2a, an annular opening formed by the lower end of the outer tube 32 and the inner tube 31. The second upper opening F2b opens into the liquid intermediate medium LM stored in the second chamber 20c at a position below the first upper opening F1b. The second lower opening F2a opens at a position between the height at which the outer tube 32 connects to the first chamber 10c and the liquid level of the liquid intermediate medium LM stored in the first chamber 10c.

[0045] The liquid intermediate medium LM in the second chamber 20c flows into the second flow path F2 through the second upper opening F2b, and then flows into the first chamber 10c through the second lower opening F2a. In other words, the second flow path F2 functions as a liquid flow path through which the liquid intermediate medium LM flows.

[0046] Meanwhile, the gaseous intermediate medium GM in the first chamber 10c flows into the first flow path F1 through the first lower opening F1a, and the gaseous intermediate medium GM in the first flow path F1 flows into the second chamber 20c through the first upper opening F1b. In other words, the first flow path F1 functions as a gas flow path through which the gaseous intermediate medium GM flows.

[0047] The liquid reservoir 40 is a portion that stores the liquid intermediate medium LM and is located above the liquid level of the liquid intermediate medium LM within the first chamber 10c. The liquid reservoir 40 is located radially outside the first flow passage F1 (inner tube 31) of the communicating tube 30 and below the second lower opening F2a of the second flow passage F2 (below the lower end of the outer tube 32).

[0048] The liquid accumulating portion 40 is formed into a downwardly convex shape. It includes a bottom portion extending radially from the outer surface of the inner tube 31 below the second lower opening F2a of the second flow path F2 to a position radially outward of the outer tube 32, and a vertical wall portion extending upward from the outer edge of the bottom portion to a position vertically above the second lower opening F2a. The upper edge of the vertical wall portion forms the upper edge 42 of the liquid accumulating portion 40. Specifically, the liquid accumulating portion 40 is configured to accumulate the liquid intermediate medium LM flowing out of the second lower opening F2a of the second flow path F2 at a height position located above the upper edge 42 of the second lower opening F2a, while allowing the accumulated liquid intermediate medium LM to overflow from the upper edge 42.

[0049] The second lower opening F2a is immersed in the liquid intermediate medium LM stored in the liquid storage portion 40. Therefore, the second flow path F2 is filled with the liquid intermediate medium LM.

[0050] Next, the operation and effects of the intermediate medium heat exchanger 1 according to the first embodiment will be described.

[0051] In the intermediate medium heat exchanger 1, the liquid intermediate medium LM accumulated in the first chamber 10c is heated by the heat source medium through the first heat transfer tube 10d, vaporizing it and transforming it into the gaseous intermediate medium GM. The gaseous intermediate medium GM temporarily accumulates in the upper portion of the first chamber 10c before rising through the first flow path F1 of the connecting tube 30 and flowing into the second chamber 20c of the liquefied gas vaporizer E2. Within the second chamber 20c, the gaseous intermediate medium GM heats the low-temperature liquefied gas through the second heat transfer tube 20d, vaporizing it. At this point, the gaseous intermediate medium GM is cooled by the low-temperature liquefied gas and condenses, transforming it back into the liquid intermediate medium LM. The liquid intermediate medium LM temporarily accumulated in the second chamber 20c then flows through the second flow path F2 of the connecting tube 30 into the liquid reservoir 40 within the first chamber 10c. While maintaining a constant amount of liquid intermediate medium LM, the liquid reservoir 40 allows the liquid intermediate medium LM to overflow from the upper edge 42 of the reservoir 40. The overflowed liquid intermediate medium LM is again accumulated in the first chamber 10c. By repeating this series of operations, the intermediate medium heat exchanger 1 transfers heat from the heat source medium to the low-temperature liquefied gas through the circulation of the intermediate medium.

[0052] As described above, in the intermediate medium heat exchanger 1 according to the first embodiment, the intermediate medium evaporator E1 has a first chamber 10c, and the liquefied gas vaporizer E2 has a second chamber 20c. The interior space of the first chamber 10c and the interior space of the second chamber 20c are connected to each other via the connecting pipe 30. Therefore, the intermediate medium heat exchanger 1 does not require a special design and can be constructed using a general-purpose heat exchanger. This can reduce costs.

[0053] Furthermore, in the intermediate medium heat exchanger 1 according to the first embodiment, the connecting tube 30 with a double-tube structure forms both the liquid and gas flow paths. This reduces the number of connecting tubes compared to a system where the liquid and gas flow paths are each formed by multiple connecting tubes with a single-tube structure, each located at a different position. Consequently, the likelihood of gaseous intermediate medium GM leaking from the welded portions of the connecting tube 30 when the connecting tube 30 is welded to the first chamber 10c and the second chamber 20c can be reduced.

[0054] In the intermediate medium heat exchanger 1 according to the first embodiment, the liquid intermediate medium LM is stored in the liquid reservoir 40 , and the second flow path F2 is filled with the liquid intermediate medium LM.

[0055] Furthermore, in the intermediate medium heat exchanger 1 according to the first embodiment, the liquid reservoir 40 of the second flow path F2 is filled with the liquid intermediate medium LM. Therefore, the second flow path F2 does not need to extend below the liquid level of the liquid intermediate medium LM in the first chamber 10 c.

[0056] Furthermore, in the intermediate medium heat exchanger 1 according to the first embodiment, a certain amount of liquid intermediate medium LM is maintained in the liquid reservoir 40. Meanwhile, the second lower opening F2a is located below the upper edge 42 of the liquid reservoir 40. Therefore, the gaseous intermediate medium GM within the first chamber 10c cannot flow from the upper edge 42 of the liquid reservoir 40 to the second lower opening F2a. Consequently, the second flow path F2 is sealed by the liquid reservoir 40.

[0057] Furthermore, in the intermediate medium heat exchanger 1 according to the first embodiment, the liquid accumulation portion 40 can be easily provided in the communicating tube 30 having the multi-layer tube structure, and thus the cost can be suppressed.

[0058] In addition, the liquid storage portion 40, the first lower opening F1a and the first upper opening F1b of the first flow path F1, and the second upper opening F2b of the second flow path F2 are not limited to Figure 1 as well as Figure 2 For example, you can also Figure 3 As shown in the first modified example, the liquid reservoir 40 is formed to include a curved surface that deflects the downward flow of the liquid intermediate medium LM passing through the liquid reservoir 40 to an upward flow. More specifically, the bottom portion of the liquid reservoir 40 may be curved to protrude downward below the second lower opening F2a of the second flow path F2.

[0059] Furthermore, the first lower opening F1a and the first upper opening F1b of the first flow path F1 may each be formed into a shape with a widened tip (inverted tapered shape) so as to increase the opening diameter.

[0060] Furthermore, the second upper opening F2b of the second flow path F2 may be formed into a shape with a narrowed tip (inverted tapered shape) so as to increase the opening diameter.

[0061] In the intermediate medium heat exchanger 1 according to the first modified example, the liquid reservoir 40 is formed into a curved surface. Therefore, the liquid intermediate medium LM passing through the liquid reservoir 40 changes direction in a curved manner. This reduces the flow resistance of the liquid intermediate medium LM passing through the liquid reservoir 40, thereby suppressing pressure loss caused by the liquid reservoir 40.

[0062] Furthermore, since the first lower opening F1a and the first upper opening F1b of the first flow path F1 are formed in an inverted tapered shape as described above, pressure loss caused by the first flow path F1 through which the gaseous intermediate medium GM flows is suppressed.

[0063] Similarly, since the second upper opening F2b of the second flow path F2 is formed in an inverted tapered shape as described above, pressure loss caused by the second flow path F2 through which the liquid intermediate medium LM flows is suppressed.

[0064] By minimizing pressure losses during the flow of the intermediate media LM and GM in at least a portion of the first flow path F1, the second flow path F2, and the liquid reservoir 40, the length of the communicating tube 30 can be reduced. Specifically, the difference in liquid level between the upper liquid level (the liquid level of the liquid intermediate medium LM stored in the second chamber 20c) and the lower liquid level (the liquid level of the liquid intermediate medium LM stored in the liquid reservoir 40) of the liquid intermediate medium LM passing through the second flow path F2 is balanced by the total pressure losses in the communicating tube 30 and the liquid reservoir 40 (the difference between the pressure in the first chamber 10c and the pressure in the second chamber 20c). Therefore, minimizing pressure losses reduces the difference in liquid level, thereby reducing the required length of the communicating tube 30.

[0065] On the other hand, the connecting pipe 30 may also have Figure 4 as well as Figure 5 The liquid inflow suppressing member 34 is shown. The liquid inflow suppressing member 34 is a member for suppressing the liquid intermediate medium LM from flowing into the first flow path F1 and is configured to extend downward from the liquid storage portion 40.

[0066] More specifically, the liquid inflow suppressing member 34 is formed in an annular shape surrounding the lower end of the inner tube 31, i.e., the first lower opening F1a of the first flow path F1, and is formed to hang down from the bottom surface of the liquid storage portion 40. The lower end portion 35 of the liquid inflow suppressing member 34 is located below the first lower opening F1a of the first flow path F1.

[0067] The liquid inflow suppressing member 34 is preferably formed continuously in the circumferential direction of the first flow path F1, but may also be formed discontinuously in the circumferential direction. Figure 5 As in the third modified example shown, the structure is inclined with respect to the vertical direction so as to be radially separated from the first lower opening F1a as it goes downward.

[0068] Figure 4 The second modification shown and Figure 5In the intermediate medium heat exchanger 1 according to the third modified example shown, a liquid inflow suppression member 34 suppresses the flow of liquid intermediate medium LM into the first flow path F1 through the first lower opening F1a. Specifically, liquid droplets may adhere to the inner surface of the first flow path F1 upon entering the first flow path F1, and the liquid inflow suppression member 34 suppresses the inflow of liquid droplets into the flow path F1. Therefore, in the intermediate medium heat exchangers 1 according to the second and third modified examples, the liquid inflow suppression member 34 suppresses a decrease in the heat exchange efficiency of the intermediate medium heat exchanger 1.

[0069] also, Figure 4 The second modification shown and Figure 5 In the intermediate medium heat exchanger 1 according to the third modified example shown, the lower end portion 35 of the liquid inflow suppression member 34 is located below the first lower opening F1a of the first flow path F1. This effectively prevents the liquid intermediate medium LM flowing out of the liquid reservoir 40 from flowing into the first flow path F1 through the first lower opening F1a, following the flow of the gaseous intermediate medium GM intended to flow into the first lower opening F1a.

[0070] and then, Figure 4 The second modification shown and Figure 5 In the intermediate medium heat exchanger 1 according to the third modified example shown, the liquid inflow suppression member 34 surrounds the first lower opening F1a in the circumferential direction of the first flow path F1. Therefore, the liquid intermediate medium LM that has flowed out from any circumferential position of the liquid reservoir 40 is suppressed from flowing into the first flow path F1 through the first lower opening F1a.

[0071] and then, Figure 5 In the aforementioned intermediate medium heat exchanger 1 described in the third modified example, the liquid inflow suppression member 34 is inclined. Specifically, the distance between the lower end 35 of the liquid inflow suppression member 34 and the first lower opening F1a is increased. This effectively prevents the liquid intermediate medium LM flowing out of the liquid reservoir 40 from flowing through the first lower opening F1a into the first flow path F1.

[0072] The fluid collection portion 40 may also be, for example, Figure 6 As shown in the fourth modified example, it is provided in the middle of the communicating pipe 30. That is, Figure 2 The liquid accumulation portion 40 shown is arranged below the lower end of the outer tube 32 in the first chamber 10c. Figure 6 In the fourth modified example shown, the liquid accumulation portion 40 is arranged between the first chamber 10 c and the second chamber 20 c and in the space formed between the inner tube 31 and the outer tube 32 .

[0073] In the fourth modification, the outer tube 32 of the communicating tube 30 includes an outer tube upper portion 32K connected to the second chamber 20c, an outer tube lower portion 32M connected to the first chamber 10c, and an outer tube enlarged diameter portion 32L provided to connect the outer tube upper portion 32K and the outer tube lower portion 32M.

[0074] The diameter of the outer tube expanded portion 32L is larger than the diameters of the outer tube upper portion 32K and the outer tube lower portion 32M. Specifically, the outer tube expanded portion 32L includes a top portion extending radially outward from the outer surface of the outer tube upper portion 32K, and an outer wall portion extending downward from the outer periphery of the top portion. The extended end of the top portion is curved or bent radially inward to connect to the upper end of the outer tube lower portion 32M. Furthermore, the outer tube expanded portion 32L covers the liquid collecting portion 40.

[0075] The liquid accumulating portion 40 is disposed within the space formed by the outer tube expanded portion 32L and the inner tube 31. The bottom portion of the liquid accumulating portion 40 extends from the outer surface of the inner tube 31 to the radially outer side of the outer tube upper portion 32K and the outer tube lower portion 32M, passing through the gap between the lower end of the outer tube upper portion 32K and the upper end of the outer tube lower portion 32M. That is, unlike the first embodiment, the bottom portion is positioned below the lower end of the outer tube upper portion 32K and above the upper end of the outer tube lower portion 32M. The vertical wall portion of the liquid accumulating portion 40 extends from the outer peripheral end of the bottom portion, outside the outer tube upper portion 32K, to above the lower end of the outer tube upper portion 32K. The upper edge 42 of the vertical wall portion forms a gap with the top portion of the outer tube expanded portion 32L. A radial gap is formed between the vertical wall portion and the outer wall portion of the outer tube expanded portion 32L. Furthermore, a gap is formed in the radial direction between the vertical wall portion and the outer tube upper portion 32K.

[0076] The second flow path F2 includes an upper flow path portion F21 extending downward from the second upper opening F2b and a lower flow path portion F22 extending upward from the second lower opening F2a.

[0077] The upper flow path portion F21 is a space formed between the outer tube upper portion 32K and the inner tube 31. A lower end portion F21s of the upper flow path portion F21 is formed by the lower end of the outer tube upper portion 32K and the inner tube 31.

[0078] The lower flow path portion F22 includes a portion formed by the upper edge 42 of the vertical wall of the liquid reservoir 40 and the top portion of the outer tube expanded diameter portion 32L; a portion formed by the liquid reservoir 40 and the outer wall of the outer tube expanded diameter portion 32L; and a portion formed by the inner tube 31 and the outer tube lower portion 32M. The upper end portion F22t of the lower flow path portion F22 forms the space between the upper edge 42 of the liquid reservoir 40 and the top portion of the outer tube expanded diameter portion 32L.

[0079] In this case, the liquid inflow suppressing member 34 may also be provided so as to extend from the inner tube 31. Specifically, the liquid inflow suppressing member 34 extends radially outward and downwardly from the outer side surface of the inner tube 31, which is located below the second lower opening F2a of the second flow passage F2 and within which the first flow passage F1 is formed. In other words, the liquid inflow suppressing member 34 is inclined with respect to the vertical direction so as to radially distance itself from the first lower opening F1a of the first flow passage F1. In this case, the lower end portion 35 of the liquid inflow suppressing member 34 is also located below the first lower opening F1a.

[0080] In the intermediate medium heat exchanger 1 according to the fourth modified example, the liquid reservoir 40 forms a downwardly convex space in which the liquid intermediate medium LM flowing out of the upper flow path portion F21 of the second flow path F2 is accumulated. Liquid intermediate medium LM overflowing from the upper edge 42 of the liquid reservoir 40 is guided along the top and outer wall of the outer tube expanded diameter portion 32L, flows into the lower flow path portion F22, and then flows into the first chamber 10c. Specifically, the liquid reservoir 40 is configured to accumulate the liquid intermediate medium LM flowing out of the lower end portion F21s of the upper flow path portion F21 while directing the accumulated liquid intermediate medium LM to the upper end portion F22t of the lower flow path portion F22.

[0081] Furthermore, in the liquid sump 40, a certain amount of liquid intermediate medium LM is maintained between the upper end F22t of the lower flow path portion F22 and the lower end F21s of the upper flow path portion F21. Since the lower end F21s of the upper flow path portion F21 is located below the upper end F22t of the lower flow path portion F22, even if the gaseous intermediate medium GM vaporized within the first chamber 10c rises in the lower flow path portion F22, it cannot flow toward the lower end F21s of the upper flow path portion F21. Consequently, the upper flow path portion F21 of the second flow path F2 is sealed by the liquid sump 40.

[0082] Furthermore, in the intermediate medium heat exchanger 1 according to the fourth modified example, the upper flow path portion F21, which is part of the second flow path F2, is liquid-sealed by the liquid reservoir 40 and filled with the liquid intermediate medium LM. Therefore, the liquid intermediate medium LM remains readily circumferential in the second flow path F2, allowing the second flow path F2 to function as a liquid flow path.

[0083] Furthermore, in the intermediate medium type heat exchanger 1 according to the fourth modified example, the liquid intermediate medium LM flows out of the liquid sump 40 provided midway in the second flow passage F2 of the connecting pipe 30 and then drips from the second lower opening F2a. At this time, the liquid intermediate medium LM, which has become droplets, is suppressed by the liquid inflow suppressing member 34 from flowing from the first lower opening F1a into the first flow passage F1 along with the gaseous intermediate medium GM flowing toward the first lower opening F1a located below and radially inward of the second lower opening F2a.

[0084] The connecting pipe 30 may also be, for example, Figure 7 As shown in the fifth modified example, in contrast to the first embodiment, the space inside the inner tube 31 functions as the second flow path F2, which is the liquid flow path, and the space between the inner tube 31 and the outer tube 32 functions as the first flow path F1, which is the gas flow path. In this case, the liquid reservoir 40 may be provided below the second lower opening F2a formed at the lower end of the inner tube 31 of the connecting tube 30.

[0085] The connecting tube 30 includes an inner tube 31 and an outer tube 32 disposed radially outward from the inner tube 31. The upper end of the outer tube 32 extends into the second chamber 20c, and the lower end extends into the first chamber 10c. Furthermore, the upper end of the outer tube 32 is positioned above the liquid level of the liquid intermediate medium LM stored in the second chamber 20c. The lower end of the outer tube 32 is positioned above the liquid level of the liquid intermediate medium LM stored in the first chamber 10c.

[0086] In the fifth variation, the inner tube 31, like the outer tube 32, has its upper end extending into the second chamber 20c and its lower end extending into the first chamber 10c. Furthermore, even if the space inside the inner tube 31 serves as the second flow path F2, which functions as a liquid flow path, the upper end of the inner tube 31 is still positioned above the liquid level of the liquid intermediate medium LM stored in the second chamber 20c. Furthermore, a concave guide groove (not shown) is formed to guide the liquid intermediate medium LM stored in the second chamber 20c from the outside of the outer tube 32, across the first flow path F1, to the inside of the inner tube 31, in the second flow path F2. The guide groove is formed by connecting the concave cutouts formed at the upper ends of the outer tube 32 and the inner tube 31, respectively, to a position below the liquid level, into a drainage-like groove. This guide groove allows the liquid intermediate medium LM located below the upper end of the outer tube 32 within the second chamber 20c to be directed to the space inside the inner tube 31, namely, the second flow path F2. The second flow path F2 is the space inside the inner tube 31, but in this variation, it also functions as a liquid flow path. Therefore, a second upper opening F2b of the second flow path F2 is formed at the point where the guide groove connects to the inner tube 31. Specifically, the second upper opening F2b of the second flow path F2 is located below the liquid level of the liquid intermediate medium LM within the second chamber 20c. The lower end of the inner tube 31 is positioned below the lower end of the outer tube 32 and above the liquid level of the liquid intermediate medium LM within the first chamber 10c.

[0087] According to the configuration of the inner tube 31 and the outer tube 32 in the fifth modification, the space inside the inner tube 31, i.e., the second flow path, can function as a liquid flow path, and the space between the inner tube 31 and the outer tube 32, i.e., the first flow path, can function as a gas flow path.

[0088] The liquid reservoir 40 is provided above the liquid level of the liquid intermediate medium LM in the first chamber 10c. In the fifth modification, the liquid reservoir 40 surrounds the second lower opening F2a of the second flow path F2 and is disposed below the first lower opening F1a of the first flow path F1.

[0089] The upper edge 42 of the liquid reservoir 40 is located above the lower end of the inner tube 31 (the second lower opening F2a of the second flow path F2) and below the lower end of the outer tube 32. Thus, a gap is formed between the upper edge 42 of the liquid reservoir 40 and the lower end of the outer tube 32.

[0090] Furthermore, the liquid intermediate medium LM can overflow from the upper edge 42 of the liquid reservoir 40 and flow downward from the aforementioned gap. Furthermore, the gaseous intermediate medium GM generated in the first chamber 10c can flow from the aforementioned gap into the first flow path F1 through the first lower opening F1a.

[0091] The fluid collection portion 40 may also be, for example, Figure 8 As shown in the sixth modified example, it is provided in the middle of the communicating pipe 30, that is, in the space inside the inner pipe 31. Figure 7 In the fifth modified example shown, the liquid accumulation portion 40 is arranged below the lower end of the inner tube 31 in the first chamber 10c. Figure 8 In the sixth modified example shown, the liquid accumulation portion 40 is arranged between the first chamber 10 c and the second chamber 20 c and is arranged in a space formed inside the inner tube 31 .

[0092] The outer tube 32 of the connecting tube 30 is connected to the Figure 6 The fourth modified example shown in the figure also has an outer tube upper portion 32K connected to the second chamber 20c, an outer tube lower portion 32M connected to the first chamber 10c, and an outer tube enlarged diameter portion 32L provided in a manner connecting the outer tube upper portion 32K and the outer tube lower portion 32M. Figure 6 The fourth modified example shown is different in that the upper end of the outer tube upper portion 32K is located above the liquid level of the liquid intermediate medium LM in the second chamber 20 c .

[0093] Furthermore, in the sixth variant, the inner tube 31 of the connecting tube 30 includes: an inner tube upper side portion 31K that enters the second chamber 20c and forms a space with the outer tube upper side portion 32K, an inner tube lower side portion 31M that enters the first chamber 10c and forms a space with the outer tube lower side portion 32M, and an inner tube enlarged diameter portion 31L that is arranged in a manner connecting the inner tube upper side portion 31K and the inner tube lower side portion 31M and forms a space with the outer tube enlarged diameter portion 32L.

[0094] The diameter of the inner tube expanded portion 31L is larger than the diameters of the inner tube upper portion 31K and the inner tube lower portion 31M. Specifically, the inner tube expanded portion 31L includes a top portion extending radially outward from the outer surface of the inner tube upper portion 31K, and an outer wall portion extending downward from the outer periphery of the top portion, with the distal end of the extension curved or bent radially inward to connect to the upper end of the inner tube lower portion 31M. Furthermore, the inner tube expanded portion 31L covers the liquid reservoir 40.

[0095] The liquid accumulation portion 40 is disposed within the space formed by the inner tube expanded portion 31L and has a downwardly convex shape. The bottom portion of the liquid accumulation portion 40 is located within the space formed inside the inner tube expanded portion 31L, between the lower end of the inner tube upper portion 31K and the upper end of the inner tube lower portion 31M, and extends radially. The vertical wall portion of the liquid accumulation portion 40 extends from the outer peripheral end of the bottom portion to above the lower end of the inner tube upper portion 31K, outside the inner tube upper portion 31K. The upper edge 42 of the vertical wall portion forms a gap with the top portion of the inner tube expanded portion 31L. The vertical wall portion also forms a gap with the outer wall portion of the inner tube expanded portion 31L. Furthermore, the vertical wall portion forms a gap in the radial direction with the inner tube upper portion 31K.

[0096] In the sixth modification, the upper flow path portion F21 of the second flow path F2 is a space formed inside the inner tube upper portion 31K. The lower end portion F21s of the upper flow path portion F21 is formed by the lower end portion of the inner tube upper portion 31K.

[0097] The lower flow path portion F22 of the second flow path F2 includes a portion formed by the upper edge 42 of the vertical wall of the liquid reservoir 40 and the top of the expanded inner tube portion 31L, a portion formed by the outer wall of the liquid reservoir 40 and the expanded inner tube portion 31L, and a portion formed inside the inner tube lower portion 31M. The upper end portion F22t of the lower flow path portion F22 is formed as the space between the upper edge 42 of the liquid reservoir 40 and the top of the expanded inner tube portion 31L.

[0098] In the intermediate medium type heat exchanger 1 according to the sixth modified example, the space inside the inner tube 31 of the connecting tube 30 becomes the second flow path F2 functioning as a liquid flow path. Figure 6 ) Similarly, in the sixth modification, the upper flow path portion F21 of the second flow path F2 is in a liquid-sealed state via the liquid storage portion 40.

[0099] In the first embodiment and its modified example, the intermediate medium type heat exchanger 1 has one communicating pipe 30, but is not limited to the configuration having one communicating pipe 30 and may also have a configuration having a plurality of communicating pipes 30. Figure 9 A seventh modified example including a plurality of communication pipes 30 will be described.

[0100] The intermediate medium type heat exchanger 1 according to the seventh modification includes a first communicating pipe 30 and a second communicating pipe 30B. The first communicating pipe 30 and the second communicating pipe 30B each have the same structure as the communicating pipe 30 described above. That is, the first communicating pipe 30 and the second communicating pipe 30B may also have the structure of the first embodiment ( Figure 1 as well as Figure 2 ) The structure of the communicating pipe 30 disclosed in the embodiment may also include the first modification to the sixth modification (from Figures 4 to 8 ) The structure of the connecting pipe 30 disclosed.

[0101] In the intermediate medium heat exchanger 1 according to the seventh modification, the plurality of connecting pipes 30 can increase the amount of the intermediate medium circulating between the intermediate medium evaporator E1 and the liquefied gas vaporizer E2 , thereby improving the efficiency of the intermediate medium heat exchanger 1 .

[0102] like Figure 10 As shown in FIG. 1 , in the intermediate medium type heat exchanger 1 according to the eighth modified example, a heat insulating member is provided in the inner tube 31 and the outer tube 32 of the connecting tube 30. Figure 10Region XI Figure 11 As shown, inner tube 31 is constructed as a three-layer insulated tube, comprising an inner tube 31A, an outer tube 31B disposed outside inner tube 31A, and a thermal insulator 31C disposed between inner and outer tubes 31A and 31B. Outer tube 32 is provided with thermal insulator 32C in the area exposed to the atmosphere. Thermal insulators 31C and 32C have a thermal conductivity of less than 1% of the thermal conductivity of inner tube 31A, outer tube 31B, and outer tube 32, and can be made of, for example, glass wool, rock wool, polystyrene foam, or rigid polyurethane foam.

[0103] The heat insulator 31C of the inner tube 31 prevents the gaseous intermediate medium GM in the first flow path F1 from being cooled and liquefied by the liquid intermediate medium LM in the second flow path F2. This prevents flooding within the first flow path F1 and reduces the intermediate medium circulation rate due to increased flow resistance. Furthermore, it prevents a decrease in the vaporization efficiency of the gaseous intermediate medium GM in the liquefied gas vaporizer E2.

[0104] The thermal insulator 31C of the inner tube 31 and the thermal insulator 32C of the outer tube 32 prevent the liquid intermediate medium LM in the second flow path F2 from being heated and vaporized by the atmospheric air and the gaseous intermediate medium GM in the first flow path F1. This prevents flooding in the second flow path F2 and reduces the intermediate medium circulation rate due to increased flow resistance. Furthermore, this prevents the liquid intermediate medium LM in the second flow path F2 from being cooled by the atmospheric air, thereby minimizing any reduction in the evaporation efficiency of the liquid intermediate medium LM in the intermediate medium evaporator E1.

[0105] Alternatively, a heat insulator may be provided on only one of the inner tube 31 and the outer tube 32 .

[0106] Alternatively, the inner tube 31 may be configured as a three-layered heat-insulated tube using a heat insulator only at a portion in contact with the second flow path F2 .

[0107] Furthermore, the outer tube 32 is provided with a heat insulator 32C at the portion in contact with the atmosphere, but the present invention is not limited thereto. For example, the outer tube 32 may be configured as a three-layered insulated tube similar to the inner tube 31, comprising an inner tube, an outer tube disposed outside the inner tube, and a heat insulator disposed between the inner and outer tubes.

[0108] Furthermore, similar to the inner tube 31 , the vertical wall and bottom of the liquid collecting portion 40 may be formed as a three-layered heat insulating member comprising an inner member, an outer member, and a heat insulating member disposed between the inner and outer members.

[0109] (Second embodiment)

[0110] Then, based on Figure 12An intermediate medium heat exchanger 1 according to a second embodiment will be described. In the second embodiment, the same components as those in the first embodiment are denoted by the same reference numerals and their descriptions are omitted, and the description will focus on the different components.

[0111] In the intermediate medium heat exchanger 1 according to the second embodiment, the internal space of the first chamber 10 c and the internal space of the second chamber 20 c are also communicated with each other via the communicating pipe 30 having the multi-layered pipe structure.

[0112] In the communicating tube 30 of the second embodiment, the inner space of the inner tube 31 serves as the second flow path F2 functioning as a liquid flow path, and the space between the inner tube 31 and the outer tube 32 serves as the first flow path F1 functioning as a gas flow path.

[0113] The lower end of the inner tube 31 is positioned lower than the lower end of the outer tube 32 and lower than the liquid level of the liquid intermediate medium LM stored in the first chamber 10c. Specifically, the second lower opening F2a of the second flow path F2 is positioned below the liquid level of the liquid intermediate medium LM in the first chamber 10c. Therefore, the second lower opening F2a is immersed in the liquid intermediate medium LM.

[0114] In the intermediate medium heat exchanger 1 according to the second embodiment, the lower end portion of the second flow path F2, namely the second lower opening F2a, which functions as a liquid flow path, is immersed in the liquid intermediate medium LM stored in the first chamber 10c. Therefore, the second flow path F2 can be operated while being entirely filled with the liquid intermediate medium LM. Consequently, even if gaseous intermediate medium GM flows into the second flow path F2, the liquid intermediate medium LM can remain readily circulated within the second flow path F2, allowing the second flow path F2 to continue functioning as a liquid flow path.

[0115] In addition, the connecting pipe 30 is not limited to Figure 12 For example, you can also Figure 13 As shown in the first modified example, the inner tube 31 is not a straight tube in the first chamber 10c, but is horizontally oriented, for example, perpendicular to the extending direction of the first heat transfer tube 10d ( Figure 13 The left and right directions) are bent into a crank shape.

[0116] Furthermore, the second lower opening F2a of the second flow path F2 is arranged below the liquid level of the liquid intermediate medium LM in the first chamber 10c and offset laterally from slightly above the first heat transfer tube 10d.

[0117] When the second lower opening F2a of the second flow path F2 of the liquid intermediate medium LM immersed in the first chamber 10c is arranged slightly above the first heat transfer tube 10d, gaseous intermediate medium GM generated from the first heat transfer tube 10d may flow into the second lower opening F2a. In contrast, in the intermediate medium heat exchanger 1 according to the first modified example, the second lower opening F2a is arranged laterally offset slightly above the first heat transfer tube 10d. This prevents the gaseous intermediate medium GM from flowing into the second flow path F2 through the second lower opening F2a.

[0118] In the configuration where the lower end of the connecting pipe 30 is located slightly above the first heat transfer pipe 10d, Figure 14 The second modification shown and Figure 15 As shown in the third modified example, a gas inflow suppressing member 50 is provided. The gas inflow suppressing member 50 suppresses the gaseous intermediate medium GM in the first chamber 10c from flowing into the second flow path F2 through the second lower opening F2a.

[0119] The gas inflow suppression member 50 is a plate-shaped member disposed horizontally between the second lower opening F2a and the first heat transfer tube 10d. Specifically, the gas inflow suppression member 50 is a gas inflow suppression plate having a portion located below the second lower opening F2a of the second flow path F2. The gas inflow suppression member 50 has an area sufficient to cover the second lower opening F2a, preventing it from being visible, when viewed from above from the bottom surface of the first chamber 10c.

[0120] Figure 14 The second modification of the second embodiment shown and Figure 15 In the intermediate medium type heat exchanger 1 according to the third modified example shown, even if the gaseous intermediate medium GM generated in the first heat transfer tube 10d in the first chamber 10c floats in the liquid, the intermediate medium GM is suppressed by the gas inflow suppression member 50 from flowing into the second flow path F2 through the second lower opening F2a.

[0121] On the other hand, in the second embodiment, it is also possible to Figure 16 As in the fourth modified example shown, the inner space of the inner tube 31 is used as a first flow path F1 functioning as a gas flow path, and the space between the inner tube 31 and the outer tube 32 is used as a second flow path F2 functioning as a liquid flow path.

[0122] In the fourth modification, the outer tube 32 forming the second flow path F2 may not be a straight tube, but may be radially away from the inner tube 31 in the first chamber 10c in a direction perpendicular to the extending direction of the first heat transfer tube 10d ( Figure 16 The left and right directions) are bent into a crank shape.

[0123] The outer tube 32 bends away from the inner tube 31 within the first chamber 10c and extends to a position below the liquid level of the liquid intermediate medium LM. Meanwhile, the first lower opening F1a of the first flow path F1 formed by the inner tube 31 is located above the liquid level. Therefore, the communicating tube 30 further includes an intermediate wall 33. The intermediate wall 33 includes a portion extending radially outward from the inner tube 31, spaced apart from the outer tube 32 wall, below the radially outward bend of the outer tube 32 and above the second lower opening F2a, to form the second flow path F2. The intermediate wall 33 also includes a portion extending radially outward from the inner tube 31, spaced apart from the outer tube 32 wall, to form the second flow path F2. The intermediate wall 33 also includes a portion extending downward from the intermediate wall 33 to a position below the liquid level of the liquid intermediate medium LM within the first chamber 10c. This ensures space for the second flow path F2 between the intermediate wall 33 and the outer tube 32, while also ensuring space between the intermediate wall 33 and the inner tube 31 for the gaseous intermediate medium GM to flow toward the first lower opening F1a.

[0124] Specifically, the space formed between the outer tube 32, the inner tube 31, and the intermediate wall 33 forms the second flow path F2. The second flow path F2 bends as the outer tube 32 and the intermediate wall 33 bend, extending to a position slightly above and laterally offset from the first heat transfer tube 10d. Furthermore, the second lower opening F2a of the second flow path F2 is located below the liquid level of the liquid intermediate medium LM within the first chamber 10c and slightly above and laterally offset from the first heat transfer tube 10d.

[0125] In the intermediate medium heat exchanger 1 according to the fourth modification, similar to the first modification of the second embodiment, the second lower opening F2a is positioned within the first chamber 10c at a position slightly above and laterally offset from the first heat transfer tube 10d. This prevents the gaseous intermediate medium GM from flowing through the second lower opening F2a into the second flow path F2.

[0126] and then, Figure 17 Indicates Figure 16 The fourth modification shown is a fifth modification of the second embodiment in which a gas inflow suppressing member 50 is further provided.

[0127] That is, the intermediate medium evaporator E1 further includes a gas inflow suppressing member 50 disposed between the second lower opening F2a of the second flow path F2 and the first heat transfer tube 10d.

[0128] This can more effectively suppress the gaseous intermediate medium GM from flowing into the second flow path F2 through the second lower opening F2a.

[0129] Next, other modifications not shown in the drawings will be described with respect to the first and second embodiments.

[0130] In the second embodiment and its modified examples, the intermediate medium heat exchanger 1 may include a plurality of communication pipes 30. In this case, the circulation rate of the intermediate medium in the entire intermediate medium heat exchanger 1 can be increased, thereby improving the efficiency of the intermediate medium heat exchanger 1.

[0131] In the connecting tube 30, the diameters of the inner tube 31 and the outer tube 32 can be set so that the hydraulic diameter of the first flow path F1 is larger than the hydraulic diameter of the second flow path F2. This allows the pressure loss in the first flow path F1, which functions as a gas flow path, to be greater than the pressure loss in the second flow path F2, which functions as a liquid flow path. Therefore, if the hydraulic diameter of the first flow path F1 is larger than that of the second flow path F2, the pressure loss caused by the first flow path F1 can be suppressed. Furthermore, suppressing the pressure loss caused by the first flow path F1 also reduces the liquid level in the second flow path F2, thereby shortening the length of the connecting tube 30.

[0132] In addition, the hydraulic diameter (DH) is a length defined as follows.

[0133] DH=4A / P

[0134] Here, A is the cross-sectional area of the flow path, and P is the perimeter of the wetted portion (wetted edge) in the cross section.

[0135] When the inner tube 31 is a circular tube, the hydraulic diameter of the flow path formed in the inner tube 31 is equal to the inner diameter of the inner tube 31. When both the inner tube 31 and the outer tube 32 are circular tubes, the hydraulic diameter DHr of the flow path formed between the inner tube 31 and the outer tube 32 is calculated as follows: when the cross-sectional area of the flow path is Ar, the outer diameter of the inner tube 31 is D1, and the inner diameter of the outer tube 32 is D2,

[0136] DHr=4Ar / {π×(D1+D2)}.

[0137] While the communicating tube 30 has been described above as having a double-tube structure consisting of an inner tube 31 and an outer tube 32, the communicating tube 30 is not limited to a double-tube structure and may also be a communicating tube having a structure consisting of multiple layers of tubes, more than two layers. In this case, it is arbitrary and not limited to which of the multiple spaces defined by the radially overlapping tubes in the communicating tube 30 is designated as a liquid flow path and which as a gas flow path.

[0138] In addition to the above Figure 13 、 Figure 15The first and third variations of the second embodiment are described assuming that the connecting tube 30 is radially symmetrical, but this is not limiting. As long as the connecting tube 30 has a multi-layered tube structure, it may also be radially asymmetrical. For example, the central axis of the inner tube 31 and the central axis of the outer tube 32 may not coincide, but may be eccentric. Furthermore, either or both of the inner tube 31 and the outer tube 32 may not be circular.

[0139] In addition, regarding the liquid accumulation portion 40, Figure 3 The first modified example of the first embodiment shown in the figure illustrates that the liquid storage section 40 can also be formed into a curved surface shape that bends the downward flow of the liquid intermediate medium LM passing through the liquid storage section 40 into an upward flow. The liquid storage section 40 in other modified examples can also be formed into a shape containing a curved surface.

[0140] like Figure 18 As shown, in the intermediate medium type heat exchanger 1 according to the sixth modified example, a heat insulating member is provided in the inner tube 31 and the outer tube 32 of the connecting tube 30. Figures 10-11 Similarly to the eighth modified example of the first embodiment described above, the inner tube 31 is constructed as a three-layer insulated tube comprising an inner tube 31A, an outer tube 31B disposed outside the inner tube 31A, and a thermal insulator 31C disposed between the inner and outer tubes 31A and 31B. A thermal insulator 32C is provided in the portion of the outer tube 32 that contacts the atmosphere.

[0141] The heat insulator 31C of the inner tube 31 prevents the liquid intermediate medium LM in the second flow path F2 from being heated and vaporized by the gaseous intermediate medium GM in the first flow path F1. This prevents flooding in the second flow path F2 and reduces the circulation rate of the intermediate medium due to increased flow resistance.

[0142] The thermal insulator 31C of the inner tube 31 and the thermal insulator 32C of the outer tube 32 prevent the gaseous intermediate medium GM in the first flow path F1 from being cooled and liquefied by the atmosphere and the liquid intermediate medium LM in the second flow path F2. This prevents flooding in the first flow path F1 and reduces the intermediate medium circulation rate due to increased flow resistance in the first flow path F1. Furthermore, it prevents a decrease in the vaporization efficiency of the gaseous intermediate medium GM in the liquefied gas vaporizer E2.

[0143] Alternatively, a heat insulator may be provided on only one of the inner tube 31 and the outer tube 32 .

[0144] Alternatively, the inner tube 31 may be configured as a three-layered heat-insulated tube using a heat insulator only at a portion in contact with the first flow path F1 .

[0145] Furthermore, a heat insulator 32C is provided at the portion of the outer tube 32 that contacts the atmosphere, but the present invention is not limited thereto. For example, the outer tube 32 may be configured as a three-layered insulated tube similar to the inner tube 31, comprising an inner tube, an outer tube disposed outside the inner tube, and a heat insulator disposed between the inner and outer tubes.

[0146] Here, the aforementioned embodiments are summarized.

[0147] (1) The intermediate medium type heat exchanger described in the above embodiment comprises: an intermediate medium evaporator having a hollow first chamber and a first heat transfer tube arranged to pass through the first chamber and into which a heat source medium flows; a liquefied gas vaporizer having a hollow second chamber arranged above the first chamber and a second heat transfer tube arranged to pass through the second chamber and into which a low-temperature liquefied gas flows; and a connecting tube having a multi-layered tube structure including an inner tube and an outer tube arranged radially outward of the inner tube, and connecting the interior space of the first chamber and the interior space of the second chamber. An intermediate medium is enclosed in the space formed by the first chamber, the second chamber, and the connecting tube. The liquid intermediate medium in the first chamber is heated by the heat source medium via the first heat transfer tube and vaporized to become a gaseous intermediate medium. The gaseous intermediate medium in the second chamber is cooled by the low-temperature liquefied gas via the second heat transfer tube and condensed to become a liquid intermediate medium. Furthermore, when one of the space inside the inner tube and the space between the inner tube and the outer tube is defined as a first flow path and the other as a second flow path, the first flow path includes a first upper opening portion opening above the liquid level of the liquid intermediate medium in the second chamber and a first lower opening portion opening above the liquid level of the liquid intermediate medium in the first chamber, thereby functioning as a gas flow path through which the gaseous intermediate medium flows. The second flow path includes a second upper opening portion opening below the liquid level of the liquid intermediate medium in the second chamber and a second lower opening opening opening in the first chamber, thereby functioning as a liquid flow path through which the liquid intermediate medium flows when at least partially filled with the liquid intermediate medium.

[0148] In an intermediate medium heat exchanger, the liquid intermediate medium accumulated in the first chamber is heated by the heat source medium via the first heat transfer tube, vaporizing it and transforming it into a gaseous intermediate medium. The gaseous intermediate medium then rises through the first flow path, functioning as a gas flow path, within the connecting tube and flows into the second chamber of the liquefied gas vaporizer. Furthermore, within the second chamber, the gaseous intermediate medium heats the low-temperature liquefied gas via the second heat transfer tube, vaporizing it. At this point, the gaseous intermediate medium is cooled by the low-temperature liquefied gas and condenses, transforming it into a liquid intermediate medium again. Furthermore, the liquid intermediate medium accumulated in the second chamber flows through the second flow path, functioning as a liquid flow path, within the connecting tube and into the first chamber. By repeating this series of operations, heat is transferred from the heat source medium to the low-temperature liquefied gas through the circulation of the intermediate medium in the intermediate medium heat exchanger.

[0149] Furthermore, in the intermediate medium heat exchanger, the intermediate medium evaporator has the first chamber, the liquefied gas vaporizer has the second chamber, and the interior spaces of the first chamber and the second chamber are connected to each other via a connecting pipe. Therefore, specialized design and manufacturing are unnecessary and the heat exchanger can be constructed using a general-purpose heat exchanger, thereby reducing costs.

[0150] Furthermore, in an intermediate medium heat exchanger, the liquid and gas flow paths are formed using a multi-layered connecting tube. This reduces the number of connecting tubes compared to a system where the liquid and gas flow paths are formed using multiple single-tube connecting tubes located at different positions.

[0151] Furthermore, in the intermediate medium heat exchanger, the second flow path is at least partially filled with the liquid intermediate medium. Therefore, even if a gaseous intermediate medium flows into the second flow path, the liquid intermediate medium remains readily circulated within the second flow path, allowing the second flow path to function as a liquid flow path.

[0152] (2) As a preferred embodiment of the intermediate medium heat exchanger, the intermediate medium heat exchanger further includes a liquid reservoir in the second flow path, the liquid reservoir being provided above the liquid level of the liquid intermediate medium in the first chamber and accumulating the liquid intermediate medium.

[0153] In the intermediate medium heat exchanger according to this aspect, the liquid reservoir of the second flow path is filled with the liquid intermediate medium. Therefore, the second flow path does not need to extend below the liquid level of the liquid intermediate medium in the first chamber.

[0154] (3) As a preferred embodiment of the intermediate medium type heat exchanger, the liquid accumulation portion is configured to accumulate the liquid intermediate medium flowing out from the second lower opening portion of the second flow path, and on the other hand, the accumulated liquid intermediate medium is allowed to overflow from an upper edge portion located above the second lower opening portion.

[0155] In this embodiment of the intermediate medium heat exchanger, a constant amount of liquid intermediate medium is maintained in the liquid reservoir. Meanwhile, the second lower opening is located below the upper edge of the liquid reservoir. Consequently, the gaseous intermediate medium in the first chamber cannot flow from the upper edge of the liquid reservoir toward the second lower opening. Consequently, the second flow path is sealed by the liquid in the liquid reservoir.

[0156] Furthermore, in the intermediate medium type heat exchanger according to this aspect, the liquid accumulation portion can be easily provided in the communicating tube of the multi-layer tube structure, and the cost can be suppressed.

[0157] (4) As a preferred embodiment of the intermediate medium type heat exchanger, the second flow path further includes an upper flow path portion extending downward from the second upper opening portion, and a lower flow path portion extending upward from the second lower opening portion, with an upper end portion located above the lower end portion of the upper flow path portion. In this case, the liquid accumulation portion may be configured to accumulate the liquid intermediate medium flowing out of the lower end portion of the upper flow path portion, while allowing the accumulated liquid intermediate medium to flow into the upper end portion of the lower flow path portion.

[0158] In this intermediate medium heat exchanger, the liquid intermediate medium condensed in the second chamber flows from the lower end of the upper flow path portion of the second flow path into the liquid reservoir, and from there into the upper end of the lower flow path portion. At this point, a certain amount of liquid intermediate medium accumulates in the liquid reservoir between the upper end of the lower flow path portion and the lower end of the upper flow path portion. Furthermore, the lower end of the upper flow path portion is positioned below the upper end of the lower flow path portion. Therefore, even if the gaseous intermediate medium vaporized in the first chamber rises in the lower flow path portion, it will not flow to the lower end of the upper flow path portion. Consequently, the upper flow path portion of the second flow path is sealed by the liquid reservoir portion.

[0159] (5) As a preferred embodiment of the intermediate medium type heat exchanger, the liquid reservoir is formed into a shape including a curved surface that bends a downward flow of the liquid intermediate medium passing through the liquid reservoir into an upward flow.

[0160] In this embodiment of the intermediate medium heat exchanger, the liquid reservoir is formed to include the aforementioned curved surface. Therefore, the liquid intermediate medium passing through the liquid reservoir changes direction in a curved manner. This reduces the flow resistance of the liquid intermediate medium through the liquid reservoir, thereby suppressing pressure loss caused by the liquid reservoir.

[0161] (6) As a preferred embodiment of the intermediate medium type heat exchanger, the first flow path is formed as a space inside the inner tube of the connecting tube, and the second flow path is formed as a space between the inner tube and the outer tube. In this case, the connecting tube may further include a liquid inflow suppression member that suppresses the liquid intermediate medium flowing out of the liquid reservoir from flowing into the first flow path through the first lower opening along with the gaseous intermediate medium that is about to enter the first lower opening.

[0162] In the intermediate medium heat exchanger described in this embodiment, the second flow path is located radially outward from the first flow path. Therefore, in the absence of a liquid inflow suppression component, the liquid intermediate medium flowing out of the liquid reservoir tends to flow into the first flow path through the first lower opening, following the flow of the gaseous intermediate medium that is about to flow into the first lower opening. Therefore, in the first flow path functioning as a gas flow path, the liquid intermediate medium may become an obstruction to the flow of the gaseous intermediate medium. If the flow of the gaseous intermediate medium is obstructed, the circulation volume of the intermediate medium in the entire intermediate medium heat exchanger decreases, and the efficiency of the intermediate medium heat exchanger decreases. In contrast, in the intermediate medium heat exchanger described in this embodiment, the liquid inflow suppression component is used to suppress the liquid intermediate medium from flowing into the first flow path through the first lower opening. Therefore, in the intermediate medium heat exchanger described in this embodiment, the liquid inflow suppression component suppresses the decrease in the efficiency of the intermediate medium heat exchanger.

[0163] (7) As a preferred embodiment of the intermediate medium type heat exchanger, the liquid inflow suppressing member extends downward from the liquid sump and has a lower end portion located below the first lower opening of the first flow path.

[0164] In the intermediate medium heat exchanger described in this embodiment, the lower end portion of the liquid inflow suppression member extending downward from the liquid sump is located below the first lower opening of the first flow path. Therefore, the liquid intermediate medium flowing out of the liquid sump can be more effectively suppressed from flowing into the first flow path through the first lower opening along with the flow of the gaseous intermediate medium entering the first lower opening.

[0165] (8) As a preferred embodiment of the intermediate medium type heat exchanger, the liquid inflow suppressing member is inclined with respect to the vertical direction so as to be radially separated from the first lower opening of the first flow path.

[0166] In the intermediate medium type heat exchanger described in this aspect, the distance between the lower end of the liquid inflow suppression member and the first lower opening is increased, which can effectively suppress the liquid intermediate medium flowing out of the liquid reservoir from flowing into the first flow path through the first lower opening.

[0167] (9) As a preferred embodiment of the intermediate medium type heat exchanger, the liquid inflow suppressing member is formed continuously or discontinuously in the circumferential direction of the first flow path so as to surround the first lower opening of the first flow path.

[0168] In the aforementioned intermediate medium heat exchanger according to this aspect, the liquid inflow suppression member surrounds the first lower opening along the circumferential direction of the first flow path. Thus, the liquid intermediate medium, which has flowed out from any circumferential position of the liquid reservoir, is suppressed from flowing into the first flow path through the first lower opening. Furthermore, in this aspect, if the liquid inflow suppression member is formed discontinuously, the liquid inflow suppression member can suppress the inflow of the liquid intermediate medium while not suppressing the inflow of the gaseous intermediate medium.

[0169] (10) As a preferred embodiment of the intermediate medium type heat exchanger, the second lower opening of the second flow path is arranged below the liquid level of the liquid intermediate medium in the first chamber so as to be immersed in the liquid intermediate medium.

[0170] In this embodiment of the intermediate medium heat exchanger, the lower end of the second flow path, i.e., the second lower opening, which functions as a liquid flow path, is immersed in the liquid intermediate medium stored in the first chamber. Therefore, the heat exchanger can operate while the entire second flow path is filled with the liquid intermediate medium. Therefore, even if gaseous intermediate medium flows into the second flow path, the liquid intermediate medium can be maintained in the second flow path, allowing the second flow path to continue functioning as a liquid flow path.

[0171] (11) As a preferred embodiment of the intermediate medium type heat exchanger, the second lower opening of the second flow path is arranged in the first chamber at a position slightly above and laterally offset from the first heat transfer tube.

[0172] If the second lower opening of the second flow path of the liquid intermediate medium immersed in the first chamber is positioned slightly above the first heat transfer tube, there is a risk that the gaseous intermediate medium generated from the first heat transfer tube may flow into the second flow path through the second lower opening. However, in the intermediate medium heat exchanger described in this embodiment, the second lower opening is positioned in the first chamber at a position offset laterally from slightly above the first heat transfer tube, thereby preventing the gaseous intermediate medium from flowing into the second flow path through the second lower opening.

[0173] (12) As a preferred embodiment of the intermediate medium heat exchanger, the intermediate medium evaporator further includes a gas inflow suppressing member for suppressing the gaseous intermediate medium in the first chamber from flowing into the second flow path through the second lower opening.

[0174] In the intermediate medium heat exchanger according to this aspect, even if the gaseous intermediate medium generated in the first chamber of the intermediate medium evaporator floats in the liquid, it is suppressed from flowing into the second flow path through the second lower opening.

[0175] (13) As a preferred embodiment of the intermediate medium type heat exchanger, the hydraulic diameter of the first flow path is larger than the hydraulic diameter of the second flow path.

[0176] In the intermediate medium type heat exchanger according to this aspect, the pressure loss caused by the first flow path in which the gaseous intermediate medium flows is suppressed.

[0177] (14) As a preferred embodiment of the intermediate medium type heat exchanger, the first upper opening and the first lower opening of the first flow path are formed in an inverted tapered shape so as to increase their opening diameters.

[0178] In the intermediate medium type heat exchanger according to this aspect, the pressure loss caused by the first flow path in which the gaseous intermediate medium flows is suppressed.

[0179] (15) As a preferred embodiment of the intermediate medium type heat exchanger, the second upper opening of the second flow path is formed in an inverted tapered shape so as to increase the opening diameter.

[0180] In the intermediate medium type heat exchanger according to this aspect, the pressure loss caused by the second flow path in which the liquid intermediate medium flows is suppressed.

[0181] (16) As a preferred embodiment of the intermediate medium heat exchanger, the intermediate medium heat exchanger further includes a second connecting pipe. The second connecting pipe may also be a multi-layered pipe structure including an inner pipe and an outer pipe arranged radially outward of the inner pipe, connecting the interior space of the first chamber and the interior space of the second chamber. In this case, one of the space inside the inner pipe and the space between the inner pipe and the outer pipe is defined as the first flow path, and the other is defined as the second flow path.

[0182] In the intermediate medium heat exchanger according to this aspect, since a plurality of communication pipes are provided, the circulation amount of the intermediate medium circulating between the intermediate medium evaporator and the liquefied gas vaporizer can be increased, thereby improving the efficiency of the intermediate medium heat exchanger.

[0183] (17) As a preferred embodiment of the intermediate medium type heat exchanger, a heat insulating material is provided on at least one of the inner tube and the outer tube.

[0184] In the aforementioned intermediate medium type heat exchanger described in this manner, when a heat insulating member is provided in the inner tube, the influence caused by the heat exchange between the inner tube and the outer tube can be suppressed. When a heat insulating member is provided in the outer tube, the influence caused by the heat exchange between the intermediate medium flowing in the outer tube and the atmosphere can be suppressed.

[0185] In the intermediate medium type heat exchanger according to the above embodiment, the cost can be suppressed.

Claims

1. An intermediate medium heat exchanger, have: The intermediate medium evaporator comprises a hollow first chamber and a first heat transfer pipe arranged to pass through the first chamber and into which the heat source medium flows; a liquefied gas vaporizer having a hollow second chamber disposed above the first chamber, a second heat transfer pipe disposed so as to pass through the second chamber and into which the low-temperature liquefied gas flows; and The communicating tube is a multi-layered tube structure including an inner tube and an outer tube arranged radially outward of the inner tube, and connects the internal space of the first chamber and the internal space of the second chamber. An intermediate medium is sealed in the space formed by the first chamber, the second chamber and the communicating pipe. The liquid intermediate medium in the first chamber is heated by the heat source medium through the first heat transfer tube and vaporized to become a gaseous intermediate medium. The gaseous intermediate medium in the second chamber is cooled by the low-temperature liquefied gas through the second heat transfer tube and condensed into a liquid intermediate medium. When one of the space inside the inner tube and the space between the inner tube and the outer tube is defined as the first flow path and the other is defined as the second flow path, The first flow path includes a first upper opening portion opened at a position above the liquid level of the liquid intermediate medium in the second chamber and a first lower opening portion opened at a position above the liquid level of the liquid intermediate medium in the first chamber, and functions as a gas flow path through which the gaseous intermediate medium flows. The second flow path has a second upper opening portion opened at a position below the liquid level of the liquid intermediate medium in the second chamber and a second lower opening portion opened in the first chamber. When at least a portion is filled with the liquid intermediate medium, the second flow path functions as a liquid flow path for the liquid intermediate medium to flow.

2. The intermediate medium heat exchanger according to claim 1, characterized in that: The second flow path further includes a liquid reservoir provided in the first chamber at a position above the liquid level of the liquid intermediate medium and storing the liquid intermediate medium.

3. The intermediate medium heat exchanger according to claim 2, characterized in that: The liquid reservoir is configured to store the liquid intermediate medium flowing out from the second lower opening of the second flow path and to allow the stored liquid intermediate medium to overflow from an upper edge portion located above the second lower opening.

4. The intermediate medium heat exchanger according to claim 2, characterized in that: The second flow path further includes an upper flow path portion extending downward from the second upper opening portion, and a lower flow path portion extending upward from the second lower opening portion and having an upper end portion located above a lower end portion of the upper flow path portion. The liquid storage portion is configured to store the liquid intermediate medium flowing out from the lower end portion of the upper flow path portion and to allow the stored liquid intermediate medium to flow into the upper end portion of the lower flow path portion.

5. The intermediate medium heat exchanger according to claim 3 or 4, characterized in that: The liquid reservoir is formed in a shape including a curved surface for turning a downward flow of the liquid intermediate medium passing through the liquid reservoir into an upward flow.

6. The intermediate medium heat exchanger according to claim 2, characterized in that: The first flow path is formed as a space inside the inner tube of the communicating tube, and the second flow path is formed as a space between the inner tube and the outer tube. The communicating pipe further includes a liquid inflow suppressing member for suppressing the liquid intermediate medium flowing out of the liquid reservoir from flowing into the first flow path through the first lower opening along with the flow of the gaseous intermediate medium entering the first lower opening.

7. The intermediate medium heat exchanger according to claim 6, characterized in that: The liquid inflow suppressing member extends downward from the liquid sump and has a lower end portion located below the first lower opening of the first flow path.

8. The intermediate medium heat exchanger according to claim 6, characterized in that: The liquid inflow suppressing member is inclined with respect to the vertical direction so as to be radially separated from the first lower opening of the first flow path.

9. The intermediate medium heat exchanger according to claim 6, characterized in that: The liquid inflow suppressing member is formed continuously or discontinuously in a circumferential direction of the first flow path so as to surround the first lower opening of the first flow path.

10. The intermediate medium heat exchanger according to claim 1, characterized in that The second lower opening of the second flow path is arranged below the liquid level of the liquid intermediate medium in the first chamber so as to be immersed in the liquid intermediate medium.

11. The intermediate medium heat exchanger according to claim 10, characterized in that: The second lower opening of the second flow path is arranged in the first chamber at a position offset laterally from slightly above the first heat transfer tube.

12. The intermediate medium heat exchanger according to claim 10, characterized in that: The intermediate medium evaporator further includes a gas inflow suppressing member for suppressing the gaseous intermediate medium in the first chamber from flowing into the second flow path through the second lower opening.

13. The intermediate medium heat exchanger according to claim 1, characterized in that The hydraulic diameter of the first flow path is larger than the hydraulic diameter of the second flow path.

14. The intermediate medium heat exchanger according to claim 1, characterized in that The first upper opening and the first lower opening of the first flow path are formed in an inverted tapered shape so as to increase their opening diameters.

15. The intermediate medium heat exchanger according to claim 1, characterized in that: The second upper opening of the second flow path is formed in an inverted tapered shape so as to increase the opening diameter.

16. The intermediate medium heat exchanger according to claim 1, characterized in that The second communicating tube is further provided with a multilayer tube structure including an inner tube and an outer tube arranged radially outside the inner tube, and connects the internal space of the first chamber and the internal space of the second chamber to each other, so that one of the space inside the inner tube and the space between the inner tube and the outer tube serves as the first flow path, and the other serves as the second flow path.

17. The intermediate medium heat exchanger according to claim 1, characterized in that A heat insulator is provided on at least one of the inner tube and the outer tube.

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