heat exchanger

Abstract

To provide a heat exchanger that has high heat exchange efficiency and discharges condensate liquid smoothly.SOLUTION: A heat exchanger 1A for a high-temperature gas Fa containing a condensation component and a low-temperature fluid Fb includes a heat exchange core 2 comprising a flow passage structure 9 including a first flow passage 7 through which the high-temperature gas Fa flows and a second flow passage 8 through which a low-temperature fluid Fb flows which are separated by a heat transfer wall 10 along a triple-cycle minimum curve surface. The heat exchange core 2 is disposed so that circulation of the high-temperature gas Fa in the first flow passage 7 becomes a downward flow.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a heat exchanger. [Background Art]

[0002] In the technical field related to heat exchangers, a plate heat exchanger as disclosed in Patent Document 1 is known. [Prior Art Documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Unexamined Patent Application Publication No. 2002-107084 [Summary of the Invention] [Problems to be Solved by the Invention]

[0004] When a plate heat exchanger is used as a refrigerant gas condenser in a refrigeration cycle or an anode off-gas condenser in a solid oxide fuel cell system, if condensed liquid is generated in the narrow flow path between heat transfer plates, the condensed liquid may not be discharged smoothly, resulting in an increase in pressure loss. In particular, if condensed liquid containing an oxidizing substance stays inside, there is a concern that joints of heat transfer plates and the like may be corroded. If the flow path cross-sectional area of the plate heat exchanger is designed to be large so that the condensed liquid can be discharged smoothly, the heat exchange efficiency will decrease.

[0005] An object of the present disclosure is to provide a heat exchanger that has high heat exchange efficiency and allows condensed liquid to be discharged smoothly. [Means for Solving the Problems]

[0006] The present disclosure provides a heat exchanger for a high-temperature gas containing condensable components and a low-temperature fluid, comprising a heat exchange core made of a flow channel structure having a first flow channel through which the high-temperature gas flows and a second flow channel through which the low-temperature fluid flows, separated by heat transfer walls along a triple periodic minimum surface, wherein the heat exchange core is arranged such that the flow of the high-temperature gas in the first flow channel is a downward flow, and the first flow channel is formed such that the heat transfer surface density decreases from the upstream side to the downstream side, and the heat transfer surface density is defined as the sum of the surface areas of the heat transfer walls per unit apparent volume of the flow channel structure, or the sum of the wet edge lengths of the heat transfer walls per unit horizontal cross-sectional area of ​​the flow channel structure. Furthermore, according to this disclosure, a heat exchanger for a high-temperature gas containing a condensable component and a low-temperature fluid is provided, comprising a heat exchange core made of a flow channel structure having a first flow channel through which the high-temperature gas flows and a second flow channel through which the low-temperature fluid flows, separated by a heat transfer wall along a triple periodic minimum surface, wherein the heat exchange core is arranged such that the flow of the high-temperature gas in the first flow channel is a downward flow, and the first flow channel includes a non-condensable region and a condensable region of the condensable component, and is provided with a heat transfer area expanding element on one or both of the heat transfer wall and / or within the flow channel space of the non-condensable region, but the condensable region is not provided with the heat transfer area expanding element. Furthermore, according to this disclosure, a heat exchanger for a high-temperature gas containing condensable components and a low-temperature fluid comprises a heat exchange core consisting of a flow channel structure having a first flow channel through which the high-temperature gas flows and a second flow channel through which the low-temperature fluid flows, separated by a heat transfer wall along a triple periodic minimum surface, wherein the heat exchange core is arranged such that the flow of the high-temperature gas in the first flow channel is a downward flow, the first flow channel includes a non-condensable region and a condensable region of the condensable components, and the second flow channel is In the condensed region The heat exchange region is provided with a heat transfer area expansion element in one or both of the heat transfer walls and the flow path space. The heat exchange region corresponding to the non-condensing region does not have a heat transfer area expansion element. A heat exchanger is provided. [Brief explanation of the drawing]

[0007] [Figure 1] Figure 1 is a schematic diagram showing a heat exchanger according to the first embodiment. [Figure 2] Figure 2 is a schematic diagram showing a part of the flow channel structure according to the first embodiment. [Figure 3] Figure 3 is a schematic diagram showing the flow directions of the high-temperature gas and low-temperature fluid according to the first embodiment. [Figure 4] Figure 4 is a schematic diagram showing a heat exchanger according to the second embodiment. [Figure 5] Figure 5 is a schematic diagram showing a heat exchanger according to the third embodiment. [Figure 6] Figure 6 is an enlarged view of the heat transfer wall facing the non-condensing region of the first channel according to the fourth embodiment. [Figure 7] Figure 7 is an enlarged view of the heat transfer wall facing the non-condensing region of the first channel according to the fourth embodiment. [Figure 8] Figure 8 is an enlarged view of the heat transfer wall facing the non-condensing region of the first channel according to the fourth embodiment. [Figure 9] Figure 9 is a diagram illustrating the installation location of the heat transfer area expansion element according to the fourth embodiment. [Figure 10] Figure 10 is a schematic diagram showing a heat transfer core according to the fifth embodiment. [Modes for carrying out the invention]

[0008] The embodiments of this disclosure will be described below with reference to the drawings, but this disclosure is not limited to these embodiments. The components of the embodiments described below can be combined as appropriate. In addition, some components may not be used.

[0009] In this embodiment, a three-dimensional Cartesian coordinate system is established, and the positional relationships of each part are described with reference to this three-dimensional Cartesian coordinate system. The direction parallel to the X-axis in the horizontal plane is defined as the X-axis direction. The direction parallel to the Y-axis perpendicular to the X-axis in the horizontal plane is defined as the Y-axis direction. The direction parallel to the Z-axis perpendicular to both the X-axis and the Y-axis is defined as the Z-axis direction. The X-axis direction is the front-back direction. The Y-axis direction is the left-right direction. The Z-axis direction is the up-down direction. The +X direction is forward. The -X direction is backward. The +Y direction is left. The -Y direction is right. The +Z direction is upward. The -Z direction is downward.

[0010] [First Embodiment] The first embodiment will be described.

[0011] Figure 1 is a diagram schematically showing a heat exchanger 1A according to the present embodiment. The heat exchanger 1A performs heat exchange between a high-temperature gas Fa containing a condensable component and a low-temperature fluid Fb. The heat exchanger 1A is used, for example, as a condenser of a heat pump type water heater.

[0012] As shown in Figure 1, the heat exchanger 1A includes a heat exchange core 2, an upper header 3, a lower header 4, a left header 5, and a right header 6.

[0013] The heat exchange core 2 consists of a flow channel structure 9 having a first flow channel 7 through which the high-temperature gas Fa flows and a second flow channel 8 through which the low-temperature fluid Fb flows. The flow channel structure 9 has a heat transfer wall 10 that separates the first flow channel 7 and the second flow channel 8. The heat transfer wall 10 is formed along a triply periodic minimal surface. The first flow channel 7 and the second flow channel 8 are separated by the heat transfer wall 10 along the triply periodic minimal surface. The high-temperature gas Fa flowing through the first flow channel 7 and the low-temperature fluid Fb flowing through the second flow channel 8 exchange heat via the heat transfer wall 10.

[0014] An inlet 7A of the first flow channel 7 is provided at an upper end portion of the flow channel structure 9. An outlet 7B of the first flow channel 7 is provided at a lower end portion of the flow channel structure 9.

[0015] An inlet 8A of the second flow channel 8 is provided at a lower left end portion of the flow channel structure 9. An outlet 8B of the second flow channel 8 is provided at an upper right end portion of the flow channel structure 9.

[0016] The upper header 3 is disposed above the upper end portion of the flow channel structure 9. A supply pipe 11 is connected to the upper header 3.

[0017] The lower header 4 is disposed below the lower end portion of the flow channel structure 9. A discharge pipe 12 is connected to the lower header 4.

[0018] The left header 5 is disposed to the left of the left end portion of the flow channel structure 9. A supply pipe 13 is connected to the left header 5.

[0019] The right-side header 6 is positioned to the right of the rightmost end of the flow path structure 9. The discharge pipe 14 is connected to the right-side header 6.

[0020] High-temperature gas Fa is supplied to the inlet 7A of the first flow path 7 via the supply pipe 11 and the upper header 3. The high-temperature gas Fa that flows into the inlet 7A flows through the first flow path 7.

[0021] The cryogenic fluid Fb is supplied to the inlet 8A of the second flow path 8 via the supply pipe 13 and the left header 5. The cryogenic fluid Fb that flows into the inlet 8A flows through the second flow path 8.

[0022] The high-temperature gas Fa flowing through the first channel 7 and the low-temperature fluid Fb flowing through the second channel 8 exchange heat through the heat transfer wall 10. The condensable components of the high-temperature gas Fa condense as they exchange heat with the low-temperature fluid Fb, transforming into a condensate Fc. The temperature of the low-temperature fluid Fb rises as it exchanges heat with the high-temperature gas Fa, transforming into a high-temperature fluid Fd.

[0023] In this embodiment, the high-temperature gas Fa is a superheated gaseous refrigerant. The low-temperature fluid Fb is feedwater, which is room-temperature water. The condensate Fc is a supercooled liquid refrigerant. The high-temperature fluid Fd is heated hot water. Suitable refrigerants for heat pump water heaters include hydrofluorocarbon refrigerants (such as R-134a and R-32) and natural refrigerants (such as R-744).

[0024] The condensate Fc flows out from the outlet 7B of the first channel 7. The condensate Fc that flows out from the outlet 7B of the first channel 7 is discharged to the outside of the heat exchange core 2 via the lower header 4 and the discharge pipe 12.

[0025] The high-temperature fluid Fd flows out from the outlet 8B of the second channel 8. The high-temperature fluid Fd that flows out from the outlet 8B of the second channel 8 is discharged to the outside of the heat exchange core 2 via the right header 6 and the discharge pipe 14.

[0026] Figure 2 is a schematic diagram showing a part of the flow channel structure 9 according to this embodiment. The flow channel structure 9 has a heat transfer wall 10 that follows a triple periodic minimum surface. A triple periodic minimum surface is a surface with the smallest area among surfaces that have a closed curve as its boundary in three-dimensional space. Examples of triple periodic minimum surfaces include Schoen's gyroid surface (G surface), Schwarz's D surface, or Schoen's I-WP surface. In this embodiment, the heat transfer wall 10 is formed to follow the gyroid surface.

[0027] A gyroid surface is infinitely connectable in three different directions and is a minimal surface that divides space into two regions. In this embodiment, the gyroid surface is infinitely connectable in the X-axis, Y-axis, and Z-axis directions, respectively.

[0028] A gyroid surface is a surface whose area is minimized under given boundary conditions, and whose curvature becomes zero upon integration. A gyroid surface can be represented by the following approximation using trigonometric functions, shown in equation (1).

[0029] sinx·cosy+siny·cosz+sinz·cosx=0 …(1)

[0030] The heat transfer wall 10 is a wall centered on a hypothetical curved surface represented by equation (1), with a substantially uniform thickness in the direction normal to that curved surface. In the flow channel structure 9, the total surface area of ​​the inner surface (heat transfer surface) of the first flow channel 7 and the total surface area of ​​the inner surface (heat transfer surface) of the second flow channel 8 are substantially equal.

[0031] The first flow path 7 and the second flow path 8 are separated by a heat transfer wall 10. The inlet 7A of the first flow path 7 is formed by the first open end of the first flow path 7. The outlet 7B of the first flow path 7 is formed by the second open end of the first flow path 7. The inlet 8A of the second flow path 8 is formed by the first open end of the second flow path 8. The outlet 8B of the second flow path 8 is formed by the second open end of the second flow path 8.

[0032] In this embodiment, the external shape of the channel structure 9 is substantially a rectangular parallelepiped. That is, the horizontal cross-sectional area of ​​the channel structure 9 is substantially constant from the upstream side to the downstream side.

[0033] As schematically shown in Figure 1, the first channel 7 is formed such that the heat transfer surface density decreases from the upstream side to the downstream side. The heat transfer surface density is defined as the sum of the surface areas of the heat transfer walls 10 per unit apparent volume of the channel structure 9, or the sum of the wet edge lengths of the heat transfer walls 10 per unit horizontal cross-sectional area of ​​the channel structure 9. The unit of heat transfer surface density is [m 2 / m 3 ] or [m / m 2 The unit apparent volume of the flow channel structure 9 refers to the volume including both the voids (first flow channel 7 and second flow channel 8) and the object (heat transfer wall 10) of the flow channel structure 9. The unit apparent volume of the flow channel structure 9 refers, for example, to the volume of the space shown by the outline A in Figure 2. The wet edge length refers to the perimeter of the cross section where the fluid is in contact with the solid wall surface.

[0034] In this embodiment, the flow channel structure 9 includes a first portion 9A with a first heat transfer surface density and a second portion 9B with a second heat transfer surface density smaller than the first portion 9A. The second portion 9B is located below the first portion 9A. The first portion 9A includes the inlet 7A of the first flow channel 7. The second portion 9B includes the outlet 7B of the first flow channel 7. The second portion 9B has larger voids (first flow channel 7 and second flow channel 8) than the first portion 9A, and is a portion with a coarser spatial structure of the object (heat transfer wall 10 along the G curved surface). Note that the heat transfer surface density of the first flow channel 7 is not limited to being divided into two portions as in this embodiment, but may also be divided into three or more consecutive portions.

[0035] The first flow path 7 includes a non-condensable region and a condensable region of the condensable components of the high-temperature gas Fa. The non-condensable region of the first flow path 7 is the region through which the high-temperature gas Fa flows before its condensable components (refrigerant components) are condensed. The condensable region of the first flow path 7 is the region through which the high-temperature gas Fa flows after its condensable components have been condensed. In other words, the non-condensable region of the first flow path 7 is the region through which the high-temperature gas Fa flows in a single phase. The condensable region of the first flow path 7 is the region through which the high-temperature gas Fa and condensate Fc flow in two phases, or through which the condensate Fc flows in a single phase. The non-condensable region of the first flow path 7 includes the inlet 7A of the first flow path 7. The condensable region of the first flow path 7 includes the outlet 7B of the first flow path 7.

[0036] In this embodiment, the first portion 9A includes a non-condensing region of the first flow path 7. The second portion 9B includes a condensing region of the first flow path 7. In this embodiment, the flow path structure 9 is designed such that the condensable components of the high-temperature gas Fa condense in the second portion 9B, where the heat transfer surface density is low.

[0037] Figure 3 is a schematic diagram showing the flow direction of the high-temperature gas Fa and low-temperature fluid Fb according to this embodiment. As shown in Figure 3, the heat exchange core 2 is arranged so that the flow of high-temperature gas Fa in the first flow channel 7 is downward. The high-temperature gas Fa that flows into the inlet 7A at the upper end of the flow channel structure 9 flows downward through the first flow channel 7. By flowing through the first flow channel 7, the entire amount of high-temperature gas Fa is converted into condensate Fc. The condensate Fc flows out from the outlet 7B at the lower end of the flow channel structure 9.

[0038] The heat exchange core 2 is positioned so that the flow of the low-temperature fluid Fb in the second channel 8 is upward. The low-temperature fluid Fb that flows into the inlet 8A at the lower left end of the channel structure 9 flows through the second channel 8 toward the upper right. By flowing through the second channel 8, the low-temperature fluid Fb is transformed into a high-temperature fluid Fd. The high-temperature fluid Fd flows out from the outlet 8B at the upper right end of the channel structure 9.

[0039] As described above, according to this embodiment, the heat exchange core 2 consists of a flow channel structure 9 having a first flow channel 7 through which high-temperature gas Fa flows and a second flow channel 8 through which low-temperature fluid Fb flows, separated by a heat transfer wall 10 along a triple periodic minimum surface. As a result, the high-temperature gas Fa and the low-temperature fluid Fb exchange heat while flowing through intricate, labyrinthine flow channels, thereby achieving high heat exchange efficiency. Furthermore, the heat exchange core 2 is arranged so that the flow of high-temperature gas Fa in the first flow channel 7 is a downward flow. As a result, when condensable components contained in the high-temperature gas Fa condense and produce condensate Fc, the condensate Fc is smoothly discharged from the heat exchange core 2 by gravity.

[0040] The first channel 7 is formed such that the heat transfer surface density decreases from the upstream side to the downstream side. In other words, the proportion of the channel portion increases from the upstream side to the downstream side of the channel structure 9. To put it another way, the voids (first channel 7 and second channel 8) expand from the upstream side to the downstream side of the channel structure 9, and the spatial structure of the object (heat transfer wall 10 along the G curved surface) becomes coarser. As a result, when condensable components contained in the high-temperature gas Fa condense and produce condensate Fc, the condensate Fc is smoothly discharged from the first channel 7.

[0041] [Second Embodiment] A second embodiment will now be described. In the following description, components that are the same as or equivalent to those in the above-described embodiment will be denoted by the same reference numerals, and the descriptions of those components will be simplified or omitted.

[0042] Figure 4 is a schematic diagram showing the heat exchanger 1B according to this embodiment. The heat exchanger 1B exchanges heat between a high-temperature gas Fa containing condensable components and a low-temperature fluid Fb. The heat exchanger 1B is used, for example, as a condenser in a heat pump air conditioner. In a heat pump air conditioner, the indoor unit during heating operation includes a condenser.

[0043] In this embodiment, the heat exchanger 1B includes an intake hood 15, a supply hood 16, and a fan 17.

[0044] In this embodiment, the inlet 8A of the second channel 8 is provided at the left end of the channel structure 9. The outlet 8B of the second channel 8 is provided at the right end of the channel structure 9.

[0045] The intake hood 15 is positioned to the left of the left end of the flow path structure 9. The inlet 8A of the second flow path 8 is opened to the atmosphere via the intake hood 15.

[0046] The air supply hood 16 is positioned to the right of the right end of the flow path structure 9. The outlet 8B of the second flow path 8 is opened to the atmosphere via the air supply hood 16.

[0047] Similar to the embodiments described above, the high-temperature gas Fa is a gaseous refrigerant that is a superheated gas. The condensate Fc is a liquid refrigerant that is a supercooled liquid.

[0048] In this embodiment, the low-temperature fluid Fb is indoor air, and the high-temperature fluid Fd is warm air.

[0049] The fan 17 is positioned to face the space inside the intake hood 15. The fan 17 rotates so that room air is supplied to the inlet 8A via the intake hood 15. The low-temperature fluid Fb is supplied to the inlet 8A of the second flow path 8 via the intake hood 15. The low-temperature fluid Fb that flows into the inlet 8A flows through the second flow path 8. The low-temperature fluid Fb increases in temperature by exchanging heat with the high-temperature gas Fa and changes into a high-temperature fluid Fd. The high-temperature fluid Fd flows out from the outlet 8B of the second flow path 8. The high-temperature fluid Fd that flows out from the outlet 8B of the second flow path 8 is discharged to the outside of the heat exchange core 2 via the supply hood 16.

[0050] The heat exchange core 2 is positioned so that the flow of high-temperature gas Fa in the first channel 7 is a downward flow. The heat exchange core 2 is positioned so that the flow of low-temperature fluid Fb in the second channel 8 is a horizontal flow. The low-temperature fluid Fb that flows into the inlet 8A at the left end of the channel structure 9 flows to the right through the second channel 8. By flowing through the second channel 8, the low-temperature fluid Fb is transformed into high-temperature fluid Fd. The high-temperature fluid Fd flows out from the outlet 8B at the right end of the channel structure 9.

[0051] As described above, in this embodiment as well, the high-temperature gas Fa and the low-temperature fluid Fb exchange heat while flowing through intricate, labyrinthine channels, thus achieving high heat exchange efficiency. Furthermore, when condensable components contained in the high-temperature gas Fa condense to form condensate Fc, the condensate Fc is smoothly discharged from the heat exchange core 2 by gravity.

[0052] [Third Embodiment] A third embodiment will now be described. In the following description, components that are the same as or equivalent to those in the embodiments described above will be denoted by the same reference numerals, and the descriptions of those components will be simplified or omitted.

[0053] Figure 5 is a schematic diagram of the heat exchanger 1C according to this embodiment. The heat exchanger 1C exchanges heat between a high-temperature gas Fa containing condensable components and a low-temperature fluid Fb. The heat exchanger 1C is used, for example, as an anode off-gas condenser for a solid oxide fuel cell. The anode off-gas contains water vapor and unused hydrogen generated by the power generation reaction of hydrogen and oxygen inside the cell stack. The heat exchanger 1C can separate the regenerated gas containing unused hydrogen and recover condensate used for steam reforming of hydrocarbon fuels.

[0054] Similar to the first embodiment described above, the heat exchanger 1C has an upper header 3, a lower header 4, a left header 5, and a right header 6.

[0055] The inlet 7A of the first channel 7 is provided at the upper end of the channel structure 9. The outlet 7B of the first channel 7 is provided at the lower end of the channel structure 9.

[0056] The inlet 8A of the second channel 8 is located at the lower left end of the channel structure 9. The outlet 8B of the second channel 8 is located at the upper right end of the channel structure 9.

[0057] High-temperature gas Fa is supplied to the inlet 7A of the first flow path 7 via the supply pipe 11 and the upper header 3. The high-temperature gas Fa that flows into the inlet 7A flows through the first flow path 7.

[0058] The cryogenic fluid Fb is supplied to the inlet 8A of the second flow path 8 via the supply pipe 13 and the left header 5. The cryogenic fluid Fb that flows into the inlet 8A flows through the second flow path 8.

[0059] The high-temperature gas Fa flowing through the first channel 7 and the low-temperature fluid Fb flowing through the second channel 8 exchange heat through the heat transfer wall 10. The condensable components of the high-temperature gas Fa condense as they exchange heat with the low-temperature fluid Fb, transforming into a condensate Fc. The temperature of the low-temperature fluid Fb rises as it exchanges heat with the high-temperature gas Fa, transforming into a high-temperature fluid Fd.

[0060] In this embodiment, the high-temperature gas Fa is a wet gas containing water vapor. The low-temperature fluid Fb is room-temperature water. The condensate Fc is condensed water. The high-temperature fluid Fd is high-temperature water.

[0061] The condensate Fc flows out from the outlet 7B of the first channel 7. The condensate Fc that flows out from the outlet 7B of the first channel 7 is discharged to the outside of the heat exchange core 2 via the lower header 4 and the discharge pipe 12.

[0062] The high-temperature fluid Fd flows out from the outlet 8B of the second channel 8. The high-temperature fluid Fd that flows out from the outlet 8B of the second channel 8 is discharged to the outside of the heat exchange core 2 via the right header 6 and the discharge pipe 14.

[0063] In this embodiment, dry gas Fe after water vapor condensation flows out from the outlet 7B of the first flow path 7. An exhaust pipe 18 is connected to the lower header 4. The dry gas Fe that flows out from the outlet 7B of the first flow path 7 is discharged to the outside of the heat exchange core 2 via the lower header 4 and the exhaust pipe 18.

[0064] Similar to the first embodiment described above, the heat exchange core 2 is positioned so that the flow of high-temperature gas Fa in the first channel 7 is a downward flow. The heat exchange core 2 is positioned so that the flow of low-temperature fluid Fb in the second channel 8 is an upward flow.

[0065] As described above, in this embodiment as well, the high-temperature gas Fa and the low-temperature fluid Fb exchange heat while flowing through intricate, labyrinthine channels, thus achieving high heat exchange efficiency. Furthermore, when condensable components contained in the high-temperature gas Fa condense to form condensate Fc, the condensate Fc is smoothly discharged from the heat exchange core 2 by gravity.

[0066] [Fourth Embodiment] A fourth embodiment will now be described. In the following description, components that are the same as or equivalent to those in the embodiments described above will be denoted by the same reference numerals, and their descriptions will be simplified or omitted.

[0067] Figures 6 and 7 are enlarged views of the heat transfer wall 10 facing the non-condensable region of the first channel 7 according to this embodiment. As shown in Figures 6 and 7, the first channel 7 may be provided with a heat transfer area expanding element 19 on the heat transfer wall 10 in the non-condensable region. In the example shown in Figure 6, the heat transfer area expanding element 19 includes a projection 19A provided on the heat transfer wall 10 facing the non-condensable region of the first channel 7. A fin is exemplified as the projection 19A. In the example shown in Figure 7, the heat transfer area expanding element 19 includes a concave surface 19B provided on the heat transfer wall 10 facing the non-condensable region of the first channel 7. For example, the surface of the heat transfer wall 10 may be dimpled to provide the concave surface 19B on the heat transfer wall 10.

[0068] Figure 8 is an enlarged view of the heat transfer wall 10 facing the non-condensable region of the first channel 7 according to this embodiment. As shown in Figure 8, the first channel 7 may include a heat transfer area expansion element 19 within the channel space of the non-condensable region. In the example shown in Figure 8, the heat transfer area expansion element 19 includes a metal fiber material 19C arranged within the channel space of the first channel 7. Steel wool is an example of the metal fiber material 19C. Alternatively, a triple-periodic minimum surface structure may be arranged within the channel space of the first channel 7 as the heat transfer area expansion element 19. An example of such an embodiment is a double gyroid structure formed by nesting gyroids.

[0069] By providing the heat transfer area expansion element 19 in the non-condensable region of the first channel 7, heat exchange between the high-temperature gas Fa flowing through the first channel 7 and the low-temperature fluid Fb flowing through the second channel 8 is promoted. The specific heat of gas is lower than the specific heat of liquid. In other words, gas is less efficient at transferring heat than liquid. By providing the heat transfer area expansion element 19 in the non-condensable region of the first channel 7, heat exchange between the high-temperature gas Fa flowing through the first channel 7 and the low-temperature fluid Fb flowing through the second channel 8 is promoted.

[0070] Furthermore, if the heat transfer area expansion element 19 is provided in the condensation region of the first channel 7, the pressure loss due to the condensate Fc may increase, making it difficult for the condensate Fc to be discharged from the first channel 7. For this reason, it is preferable that the heat transfer area expansion element 19 is not provided in the condensation region of the first channel 7.

[0071] The heat transfer area expanding element 19 may be provided on at least a portion of the heat transfer wall 10 facing the second flow path 8. The second flow path 8 may have the heat transfer area expanding element 19 on the heat transfer wall 10 of the heat exchange region corresponding to the non-condensing region of the first flow path 7. The second flow path 8 may have the heat transfer area expanding element 19 on the heat transfer wall 10 of the heat exchange region corresponding to the condensing region of the first flow path 7. The second flow path 8 may have the heat transfer area expanding element 19 within the flow path space of the heat exchange region corresponding to the non-condensing region of the first flow path 7. The second flow path 8 may have the heat transfer area expanding element 19 within the flow path space of the heat exchange region corresponding to the condensing region of the first flow path 7.

[0072] The heat exchange region of the second channel 8 corresponding to the non-condensing region of the first channel 7 refers to the other surface of the heat transfer wall 10 that faces the second channel 8 directly opposite the one surface of the heat transfer wall 10 that faces the non-condensing region of the first channel 7. The heat exchange region of the second channel 8 corresponding to the condensing region of the first channel 7 refers to the other surface of the heat transfer wall 10 that faces the second channel 8 directly opposite the one surface of the heat transfer wall 10 that faces the condensing region of the first channel 7 that faces the second channel 8 directly opposite the one surface of the heat transfer wall 10 that faces the condensing region of the first channel 7.

[0073] Figure 9 is a table illustrating the installation locations of the heat transfer area expanding element 19 according to this embodiment. As shown in Figure 9, in the first channel 7, it is preferable to install the heat transfer area expanding element 19 in the non-condensing region and not in the condensing region. In the second channel 8, it is possible to install the heat transfer area expanding element 19 in the heat exchange region corresponding to the non-condensing region of the first channel 7, and it is also possible to install the heat transfer area expanding element 19 in the heat exchange region corresponding to the condensing region of the first channel 7.

[0074] Furthermore, the surface area or wet edge length of the heat transfer area expansion element 19 is not included in the surface area or wet edge length of the heat transfer wall 10 when calculating the heat transfer surface density.

[0075] [Fifth Embodiment] A fifth embodiment will now be described. In the following description, components that are the same as or equivalent to those in the embodiments described above will be denoted by the same reference numerals, and the descriptions of those components will be simplified or omitted.

[0076] Figure 10 is a schematic diagram showing the heat exchange core 20 according to this embodiment. In the embodiment described above, the external shape of the flow channel structure 9 is substantially a rectangular parallelepiped. That is, the horizontal cross-sectional area of ​​the flow channel structure 9 is substantially constant from the upstream side to the downstream side. As shown in Figure 10, the external shape of the flow channel structure 9 of the heat exchange core 20 may widen from the upstream side to the downstream side. That is, the horizontal cross-sectional area of ​​the flow channel structure 9 may gradually expand from the upstream side to the downstream side. The external shape of the flow channel structure 9 may be a truncated cone, a square truncated cone, or a hexagonal truncated cone. In the example shown in Figure 10, similar to the embodiment described above, the first flow channel 7 is formed such that the heat transfer surface density decreases from the upstream side (upper side) to the downstream side (lower side).

[0077] [Other embodiments] In the above-described embodiment, the heat exchange core 2 may be a shell structure in which at least one of the first inlet surface of the flow channel structure 9 provided with the inlet 7A, the second inlet surface of the flow channel structure 9 provided with the inlet 8A, the first outlet surface of the flow channel structure 9 provided with the outlet 7B, and the second outlet surface of the flow channel structure 9 provided with the outlet 8B is open to the inside of the box.

[0078] In the above-described embodiment, the heat exchange core 2 may be attached to the gas phase portion of the gas-liquid separation tank with the first outlet surface of the flow channel structure 9, which is provided with the outlet 7B, open. [Explanation of Symbols]

[0079] 1A...Heat exchanger, 1B...Heat exchanger, 1C...Heat exchanger, 2...Heat exchange core, 3...Upper header, 4...Lower header, 5...Left header, 6...Right header, 7...First flow path, 7A...Inlet, 7B...Outlet, 8...Second flow path, 8A...Inlet, 8B...Outlet, 9...Flow path structure, 9A...First part, 9B...Second part, 10...Heat transfer wall, 11...Supply pipe, 12...Discharge pipe, 13...Supply pipe, 14...Discharge pipe, 15...Intake hood, 16...Supply hood, 17...Fan, 18...Exhaust pipe, 19...Heat transfer area expansion element, 19A...Protrusion, 19B...Concave surface, 19C...Metal fiber, 20...Heat exchange core, A...Outline, Fa...High temperature gas, Fb...Low temperature fluid, Fc...Condensate, Fd...High temperature fluid, Fe...Dry gas.

Claims

1. A heat exchanger for a high-temperature gas containing condensable components and a low-temperature fluid, The heat exchange core comprises a flow channel structure having a first flow channel through which the high-temperature gas flows and a second flow channel through which the low-temperature fluid flows, separated by a heat transfer wall along a triple periodic minimum surface. The heat exchange core is arranged such that the flow of the high-temperature gas in the first flow path is a downward flow. The first channel is formed such that the heat transfer surface density decreases from the upstream side to the downstream side. The heat transfer surface density is defined as the sum of the surface areas of the heat transfer walls per unit apparent volume of the flow channel structure, or the sum of the wet edge lengths of the heat transfer walls per unit horizontal cross-sectional area of ​​the flow channel structure. heat exchanger.

2. A heat exchanger for a high-temperature gas containing condensable components and a low-temperature fluid, The heat exchange core comprises a flow channel structure having a first flow channel through which the high-temperature gas flows and a second flow channel through which the low-temperature fluid flows, separated by a heat transfer wall along a triple periodic minimum surface. The heat exchange core is arranged such that the flow of the high-temperature gas in the first flow path is a downward flow. The first flow channel includes a non-condensable region and a condensable region of condensable components, and is provided with a heat transfer area expanding element in one or both of the heat transfer wall and / or the flow channel space of the non-condensable region, and is not provided with the heat transfer area expanding element in the condensable region. heat exchanger.

3. A heat exchanger for a high-temperature gas containing condensable components and a low-temperature fluid, The heat exchange core comprises a flow channel structure having a first flow channel through which the high-temperature gas flows and a second flow channel through which the low-temperature fluid flows, separated by a heat transfer wall along a triple periodic minimum surface. The heat exchange core is arranged such that the flow of the high-temperature gas in the first flow path is a downward flow. The first channel includes a non-condensable region and a condensable region of the condensable component. The second flow path is provided with a heat transfer area expansion element in one or both of the heat transfer wall and the flow path space in the heat exchange region corresponding to the condensation region, and is not provided with the heat transfer area expansion element in the heat exchange region corresponding to the non-condensation region. heat exchanger.

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