Separated heat exchanger and fuel cell cogeneration system

Abstract

The embodiment of the utility model provides a separated heat exchanger and a fuel cell cogeneration system. Wherein the separated heat exchanger comprises a high-temperature heat exchanger, a low-temperature heat exchanger and a tail liquid collecting device. The low-temperature heat exchanger and the high-temperature heat exchanger are separately arranged, the high-temperature heat exchanger is provided with a tail exhaust condensation channel and a working medium gasification channel which can exchange heat, and a tail exhaust inlet of the tail exhaust condensation channel is used for being communicated with a tail exhaust pipe of a battery; the low-temperature heat exchanger is provided with a cooling water channel and a working medium liquefaction channel which can exchange heat, the working medium liquefaction channel and the working medium liquefaction channel are communicated through a pipeline to form a working medium cooling circulation channel, an organic phase change working medium circulates in the working medium cooling circulation channel, and the boiling point of the organic phase change working medium is lower than the preset temperature. Therefore, the separated heat exchanger has the advantages of improving the heat recovery rate and being high in arrangement flexibility.

Description

Technical Field

[0001] The utility model relates to the technical field of fuel cells, in particular to a separate heat exchanger and a fuel cell cogeneration system with the separate heat exchanger. Background Art

[0002] Fuel cell power generation devices continuously generate exhaust gas during operation, but since the temperature of the exhaust generally does not exceed 100°C, it is a low-quality heat source. At present, the exhaust is basically discharged directly into the air without secondary recycling. However, as the power generation increases, the heat directly discharged through the exhaust will cause a large amount of heat waste. The fuel cell cogeneration system realizes the efficient utilization of system energy and has high economic value and social benefits. In related technologies, traditional fuel cell cogeneration solutions mostly recover heat from the main and auxiliary cooling circuits of the fuel cell. The recovered heat can be supplied to users for heating or heating, etc., and the heat exchangers used are mostly plate heat exchangers. The plate heat exchangers of cogeneration products are generally larger in size and have certain requirements for the inlet and outlet water temperatures on the primary side of the heat exchanger. They are directly used to recover low-grade heat in the exhaust, and there is a problem of low recovery rate. Summary of the Invention

[0003] The present invention aims to at least partially address one of the technical problems in the related art. To this end, embodiments of the present invention provide a split heat exchanger. This split heat exchanger has the advantages of improved heat recovery and high layout flexibility.

[0004] The embodiment of the present utility model further provides a fuel cell cogeneration system.

[0005] The separate heat exchanger of the embodiment of the present utility model comprises a high-temperature heat exchanger, a low-temperature heat exchanger and a tail liquid collecting device. The low-temperature heat exchanger and the high-temperature heat exchanger are separately arranged.

[0006] The high-temperature heat exchanger has a tail discharge condensation channel and a working fluid vaporization channel capable of heat exchange, and the tail discharge inlet of the tail discharge condensation channel is used to communicate with the tail discharge pipe of the battery; the low-temperature heat exchanger has a cooling water channel and a working fluid liquefaction channel capable of heat exchange, and the cooling water channel can be connected with external cooling water to liquefy the organic phase change working fluid in the working fluid liquefaction channel, and the working fluid liquefaction channel and the working fluid vaporization channel are connected through a pipeline to form a working fluid cooling circulation channel, and an organic phase change working fluid circulates in the working fluid cooling circulation channel, and the boiling point of the organic phase change working fluid is lower than the preset temperature; the tail liquid collecting device is connected with the tail discharge liquid outlet of the tail discharge condensation channel to collect cooling water in the tail gas.

[0007] The separate heat exchanger of the embodiment of the present utility model is connected through the working medium gasification channel of the high-temperature heat exchanger and the working medium liquefaction channel of the low-temperature heat exchanger to form a working medium cooling circulation channel. The organic phase change working medium can circulate in the working medium cooling circulation channel. The boiling point of the organic phase change working medium is lower than the preset temperature, so that the gasification of the organic phase change working medium is used to connect the tail pipe of the fuel cell with the tail exhaust condensation channel to cool the water vapor in the tail exhaust. At the same time, external cooling water is introduced into the cooling water channel to liquefy the organic phase change working medium in the working medium liquefaction channel. The heated cooling water after heat exchange is discharged from the low-temperature working medium outlet to be used and can be supplied to the user end for use, achieving the purpose of heat recovery and utilization. The gaseous organic working medium after heating in the working medium cooling circulation channel undergoes heat exchange with the low-temperature cooling liquid phase to become a liquid organic working medium. After liquefaction, it flows back into the working medium gasification channel along the working medium liquefaction outlet of the heat pipe, completing the circulation of the organic working medium. This heat transfer method is latent heat, which is a highly efficient heat transfer method. Under low working fluid flow, the utility model can improve the energy recovery rate of the tail exhaust of the fuel cell, and realize the direct waste heat recovery and reuse of the tail exhaust liquid with low cost and high recovery efficiency to the greatest extent.

[0008] In addition, setting the high-temperature heat exchanger and the low-temperature heat exchanger separately can improve the flexibility of the layout of the high-temperature heat exchanger and the low-temperature heat exchanger. Compared with the heat pipe structure with an overall setting, there is no need to reserve a large placement space, which can improve the flexibility of the layout of the high-temperature heat exchanger and the low-temperature heat exchanger.

[0009] Therefore, the separate heat exchanger of the embodiment of the present invention has the advantages of improving the heat recovery rate and high layout flexibility.

[0010] In some embodiments, the high-temperature heat exchanger includes a high-temperature shell and a first gravity-type heat pipe arranged in the high-temperature shell, the working medium vaporization channel is formed in the first gravity-type heat pipe, and the cavity between the inner wall surface of the high-temperature shell and the outer wall surface of the first gravity-type heat pipe forms the tail exhaust condensation channel.

[0011] In some embodiments, the low-temperature heat exchanger includes a low-temperature shell and a second gravity-type heat pipe arranged in the low-temperature shell, the working medium liquefaction channel is formed in the second gravity-type heat pipe, and the cavity between the inner wall surface of the low-temperature shell and the outer wall surface of the second gravity-type heat pipe forms the cooling water channel.

[0012] In some embodiments, the high-temperature tube shell and the low-temperature tube shell both include a vacuum insulation layer and a liquid wick, the liquid wick is attached to the inner wall surface of the vacuum insulation layer, and the liquid wick is arranged on the inner wall surface of the vacuum insulation layer. The vacuum insulation layer and the outer wall surface of the second gravity-type heat pipe form the cooling water channel.

[0013] In some embodiments, each of the first gravity-type heat pipe and the second gravity-type heat pipe includes a plurality of sections of corrugated pipes connected end to end in sequence.

[0014] In some embodiments, the high-temperature tube shell has a tail drain inlet, a gas outlet and a tail drain liquid port connected to the tail drain condensation channel, the tail drain liquid port is arranged at the bottom of the high-temperature tube shell, the tail drain inlet and the gas outlet are arranged opposite to each other in the length direction of the high-temperature heat exchanger, and the tail drain liquid port and the gas outlet are both connected to the tail liquid collecting device through a pipeline.

[0015] In some embodiments, the second gravity-type heat pipe has an air inlet and a working fluid discharge port, the air inlet is arranged at the top of the second gravity-type heat pipe, and the working fluid discharge port is arranged at the bottom of the second gravity-type heat pipe.

[0016] In some embodiments, the separate heat exchanger further includes a three-way valve and a liquid inlet pipe, one end of the liquid inlet pipe is connected to the liquid inlet of the cooling water channel, and the other end of the liquid inlet pipe can be switchably connected to the tail discharge port of the tail liquid collecting device and the external cooling water source through the three-way valve.

[0017] In some embodiments, the tail liquid collection device includes a tail drain water collecting tank, a top cover plate and a steam condensation pipe. The top cover plate is covered on the tail drain water collecting tank. The top cover plate has a cover plate exhaust port. The tail drain liquid port of the tail drain condensation channel is connected to the tail drain water collecting tank. The steam condensation pipe is connected to the tail drain water collecting tank through the cover plate exhaust port. The liquid discharge port of the tail drain water collecting tank can be connected to the external heating system and / or the cooling water channel.

[0018] In some embodiments, an insulation layer, a liquid level gauge and a one-way valve are provided in the tail drain water collecting tank. The tail drain water collecting tank is connected to the cooling water channel through a return liquid pipe. The one-way valve is arranged on the return liquid pipe, and the one-way valve responds to the liquid level gauge signal.

[0019] In some embodiments, the steam condenser is in the form of a spiral coil, and the lower end of the spiral coil is connected to the upper end of the tail drain water collecting tank.

[0020] In some embodiments, the top cover plate is a curved top cover.

[0021] The fuel cell cogeneration system of an embodiment of the present invention is characterized by comprising a fuel cell and a separate heat exchanger according to any one of the above, wherein the tail exhaust pipe of the fuel cell is connected to the tail exhaust condensation channel to cool the tail exhaust. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is a flow chart of a separate heat exchanger according to an embodiment of the present invention.

[0023] Figure 2 This is a diagram showing the coordination of the high-temperature heat exchanger and the low-temperature heat exchanger according to an embodiment of the present utility model.

[0024] Figure 3 This is a left side sectional view of a low temperature heat exchanger according to an embodiment of the present invention.

[0025] Figure 4 This is a front cross-sectional view of a low-temperature heat exchanger according to an embodiment of the present invention.

[0026] Figure 5 This is a schematic structural diagram of a second gravity-type heat pipe according to an embodiment of the present invention.

[0027] Reference numerals:

[0028] High temperature heat exchanger 1; high temperature shell and tube 11; tail discharge inlet 111; gas outlet 112; tail discharge liquid outlet 113;

[0029] a first gravity-type heat pipe 12;

[0030] Low-temperature heat exchanger 2; low-temperature shell and tube 21; vacuum insulation layer 211; liquid wick 212; second gravity heat pipe 22; air inlet 221; working fluid discharge port 222; working fluid exhaust pipe 201; working fluid return pipe 202;

[0031] Tail liquid collecting device 3; tail water collecting tank 31; insulation layer 311; liquid level meter 312; one-way valve 313;

[0032] Top cover plate 32; steam condensation pipe 33;

[0033] Liquid inlet pipe 4;

[0034] Tail exhaust pipe 5. DETAILED DESCRIPTION

[0035] The embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to be used to explain the present invention, but should not be understood as limiting the present invention.

[0036] Reference below Figure 1-Figure 5 The invention describes a separate heat exchanger and a fuel cell cogeneration system according to an embodiment of the invention.

[0037] The separate heat exchanger of the embodiment of the present invention comprises a high-temperature heat exchanger 1, a low-temperature heat exchanger 2 and a tail liquid collecting device 3. The low-temperature heat exchanger 2 and the high-temperature heat exchanger 1 are arranged separately.

[0038] The high-temperature heat exchanger 1 has a tail discharge condensation channel and a working fluid vaporization channel capable of heat exchange. The tail discharge inlet 111 of the tail discharge condensation channel is used to communicate with the tail discharge pipe 5 of the battery; the low-temperature heat exchanger 2 has a cooling water channel and a working fluid liquefaction channel capable of heat exchange. The cooling water channel can be connected with external cooling water to liquefy the organic phase change working fluid in the working fluid liquefaction channel. The working fluid liquefaction channel and the working fluid vaporization channel are connected through a pipeline to form a working fluid cooling circulation channel. An organic phase change working fluid circulates in the working fluid cooling circulation channel, and the boiling point of the organic phase change working fluid is lower than the preset temperature; the tail liquid collecting device 3 is connected with the tail discharge liquid port 113 of the tail discharge condensation channel to collect cooling water in the exhaust gas.

[0039] The separate heat exchanger of the embodiment of the present utility model is connected through the working fluid vaporization channel of the high-temperature heat exchanger 1 and the working fluid liquefaction channel of the low-temperature heat exchanger 2 to form a working fluid cooling circulation channel. The organic phase change working fluid can circulate in the working fluid cooling circulation channel. The boiling point of the organic phase change working fluid is lower than the preset temperature, so that the gasification of the organic phase change working fluid is used to connect the tail pipe 5 of the fuel cell with the tail exhaust condensation channel to cool the water vapor in the tail exhaust. At the same time, external cooling water is introduced into the cooling water channel to liquefy the organic phase change working fluid in the working fluid liquefaction channel. The heated cooling water after heat exchange is discharged from the low-temperature working fluid outlet to be used and can be supplied to the user end for use, achieving the purpose of heat recovery and utilization. The gaseous organic working fluid after heating in the working fluid cooling circulation channel is transformed into liquid organic working fluid by heat exchange with the low-temperature cooling liquid phase. After liquefaction, it flows back into the working fluid vaporization channel along the working fluid liquefaction outlet of the heat pipe, completing the circulation of the organic working fluid. This heat transfer method is latent heat, which is an efficient heat transfer method. Under low working fluid flow, the utility model can improve the energy recovery rate of the tail exhaust of the fuel cell, and realize the direct waste heat recovery and reuse of the tail exhaust liquid with low cost and high recovery efficiency to the greatest extent.

[0040] In addition, setting the high-temperature heat exchanger 1 and the low-temperature heat exchanger 2 separately can improve the flexibility of the layout of the high-temperature heat exchanger 1 and the low-temperature heat exchanger 2. Compared with the heat pipe structure with an overall setting, there is no need to reserve a larger placement space, which can improve the flexibility of the layout of the high-temperature heat exchanger 1 and the low-temperature heat exchanger 2.

[0041] Therefore, the separate heat exchanger of the embodiment of the present invention has the advantages of improving the heat recovery rate and high layout flexibility.

[0042] It should be noted that the high temperature heat exchanger 1 is relative to the low temperature heat exchanger 2. The temperature of the exhaust gas in the high temperature heat exchanger 1 is higher than the temperature of the external cooling water in the low temperature heat exchanger 2.

[0043] like Figure 1 and Figure 2As shown, the high-temperature heat exchanger 1 and the low-temperature heat exchanger 2 are connected in a circular manner through the working medium exhaust pipe 201 and the working medium return pipe 202 to form a working medium cooling circulation channel.

[0044] like Figure 1 and Figure 2 As shown, the high-temperature heat exchanger 1 includes a high-temperature shell and tube 11 and a first gravity-type heat pipe 12 arranged in the high-temperature shell and tube 11. A working medium vaporization channel is formed in the first gravity-type heat pipe 12, and a cavity between the inner wall surface of the high-temperature shell and tube 11 and the outer wall surface of the first gravity-type heat pipe 12 forms a tail condensation channel.

[0045] The separate heat exchanger of the embodiment of the present invention forms the hot end of the heat exchanger by dividing the high-temperature heat exchanger 1 into a high-temperature shell and tube 11 and a first gravity-type heat pipe 12. The gravity-type heat pipe design also has the advantages of relatively high heat exchange efficiency and small total volume.

[0046] like Figures 1 to 4 As shown, the low-temperature heat exchanger 2 includes a low-temperature shell 21 and a second gravity-type heat pipe 22 disposed within the low-temperature shell 21. The second gravity-type heat pipe 22 forms a working medium liquefaction channel, and the cavity between the inner wall of the low-temperature shell 21 and the outer wall of the second gravity-type heat pipe 22 forms a cooling water channel. Similarly, the split heat exchanger of this embodiment of the utility model has the advantages of simple structure and high heat exchange efficiency.

[0047] like Figure 3 and Figure 4 As shown, both the high-temperature tube shell 11 and the low-temperature tube shell 21 include a vacuum insulation layer 211 and a liquid wick 212. The liquid wick 212 is attached to the inner wall surface of the vacuum insulation layer 211. The liquid wick 212 is arranged on the inner wall surface of the vacuum insulation layer 211. The vacuum insulation layer 211 and the outer wall surface of the second gravity-type heat pipe 22 form a cooling water channel.

[0048] The split heat exchanger of the embodiment of the present invention divides the high-temperature shell and tube 11 and the low-temperature shell and tube 21 equally into a vacuum insulation layer 211 and a liquid wick 212. The provided liquid wick 212 can effectively return the liquid from the condensation zone to the evaporation zone through capillary action, thereby significantly improving the heat transfer efficiency of the heat pipe.

[0049] like Figure 5 As shown, each of the first gravity-type heat pipe 12 and the second gravity-type heat pipe 22 comprises multiple sections of corrugated tubes connected end-to-end. Compared to a straight tube design, the corrugated tube structure improves heat exchange efficiency due to its larger heat exchange area, thereby achieving efficient phase change heat transfer between fluids at low working fluid flow rates. This further enhances the flexibility of heat exchanger layout.

[0050] like Figure 1 and Figure 2 As shown, the high-temperature tube shell 11 has a tail drain inlet 111, a gas outlet 112 and a tail drain liquid port 113 connected to the tail drain condensation channel. The tail drain liquid port 113 is arranged at the bottom of the high-temperature tube shell 11. The tail drain inlet 111 and the gas outlet 112 are arranged opposite to each other in the length direction of the high-temperature heat exchanger 1. The tail drain liquid port 113 and the gas outlet 112 are both connected to the tail liquid collecting device 3 through a pipeline.

[0051] The separate heat exchanger of the present invention has a tail liquid discharge port 113 located at the bottom of the high-temperature shell 11, allowing the cooled condensed water to automatically flow back to the tail liquid collection device 3 under the action of gravity, eliminating the need for an additional transfer pump. This simplifies the equipment setup.

[0052] In addition, the tail discharge inlet 111 and the gas outlet 112 are arranged opposite to each other in the longitudinal direction of the high-temperature heat exchanger 1, and the tail discharge liquid port 113 and the gas outlet 112 are both connected to the tail liquid collecting device 3 through pipes. This not only allows the cooled gas to continue to be cooled, but also facilitates the collection of condensed water.

[0053] like Figure 1 and Figure 2 As shown, the high-temperature heat exchanger 1 is set at a higher height than the low-temperature heat exchanger 2, and the second gravity-type heat pipe 22 has an air inlet 221 and a working fluid discharge port 222. The air inlet 221 is set at the top of the double gravity-type heat pipe, and the working fluid discharge port 222 is set at the bottom of the double gravity-type heat pipe.

[0054] The split heat exchanger of the present invention embodiment, by locating the working medium discharge port 222 of the second gravity-type heat pipe 22 at its bottom, facilitates automatic reflux of the liquefied medium therein, without the need for an additional pump body to drive it. Thus, the split heat exchanger has the advantage of simplifying the equipment configuration.

[0055] like Figure 1 As shown, the split heat exchanger of this embodiment of the utility model further includes a three-way valve (not shown) and a liquid inlet pipe 4. One end of the liquid inlet pipe 4 is connected to the liquid inlet of the cooling water channel, and the other end of the liquid inlet pipe 4 is switchably connected to the tail liquid discharge port 113 of the tail liquid collection device 3 and the external cooling water source through the three-way valve. It will be understood that the phase change of the organic phase change medium in the low-temperature heat exchanger 2 can pass through the external cooling water and the cooling water in the tail liquid collection device 3.

[0056] The separate heat exchanger of the present embodiment utilizes a three-way valve and a liquid inlet pipe 4, the other end of which is switchably connected to the tail liquid discharge port 113 of the tail liquid collecting device 3 and an external cooling water source via the three-way valve, thereby enabling the organic phase change working medium to circulate in the working medium cooling circulation channel. Thus, the separate heat exchanger contributes to improved application flexibility.

[0057] Optionally, low-temperature cooling water at 0°C-10°C can be used. The heated coolant after heat exchange is discharged from the low-temperature working medium outlet to be used and can be supplied to the user end for use.

[0058] like Figure 1 As shown, the tail liquid collecting device 3 includes a tail drain water collecting tank 31, a top cover plate 32 and a steam condensing pipe 33. The top cover plate 32 is covered on the tail drain water collecting tank 31. The top cover plate 32 has a cover plate exhaust port. The tail drain liquid port 113 of the tail drain condensation channel is connected to the tail drain water collecting tank 31. The steam condensing pipe 33 is connected to the tail drain water collecting tank 31 through the cover plate exhaust port. The discharge port of the tail drain water collecting tank 31 is connected to the external heating system.

[0059] The separate heat exchanger of the present embodiment, by connecting the tail liquid collecting device 3, which includes a tail discharge water collecting tank 31, a top cover plate 32, and a steam condensing pipe 33, to the tail discharge liquid outlet 113 of the tail discharge condensation channel with the tail discharge water collecting tank 31, can collect water vapor and heat in the tail gas, and use the collected hot water for heating and other purposes. Furthermore, the separate heat exchanger has the advantage of improving waste heat recovery efficiency.

[0060] like Figure 1 As shown, the tail drain water collection tank 31 is equipped with an insulation layer 311, a liquid level gauge 312, and a one-way valve 313. The tail drain water collection tank 31 is connected to the cooling water channel via a return pipe. The one-way valve 313 is installed on the return pipe and responds to the signal of the liquid level gauge 312. Therefore, the liquid level gauge 312 and the one-way valve 313 can respond to the excess water in the tail drain water collection tank 31 and inject it into the heating and cooling system.

[0061] like Figure 1 As shown, the steam condensing pipe 33 is a spiral coil, and the lower end of the spiral coil is connected to the upper end of the tail water collecting tank 31. Therefore, the separate heat exchanger of the embodiment of the utility model has the advantage of good condensation effect.

[0062] Optionally, the placement shape of the spiral coil is not limited to horizontal or vertical placement.

[0063] like Figure 1 As shown, the top cover plate 32 is a dome-shaped top cover. The water vapor is further condensed and then refluxed. Therefore, the split heat exchanger has the advantage of saving water.

[0064] The fuel cell cogeneration system of the embodiment of the present invention includes a fuel cell and a separate heat exchanger according to any one of the above items. The tail exhaust pipe 5 of the fuel cell is connected to the tail exhaust condensation channel to cool the tail exhaust.

[0065] Therefore, the fuel cell cogeneration system of the embodiment of the present invention has the advantages of improving the heat recovery rate and high layout flexibility.

[0066] Exemplarily, the high-temperature shell and tube 11 of the high-temperature heat exchanger 1 is provided with a tail discharge working fluid liquefaction inlet, a working fluid vaporization outlet, a tail discharge inlet 111, a gas outlet 112 and a tail discharge liquid outlet 113. The interior of the first gravity-type heat pipe 12 is composed of a plurality of corrugated tubular heat pipes, and the plurality of corrugated tubes are connected at the ends, and the interior is filled with a low-boiling-point organic phase change working fluid (such as R245fa). The working fluid liquefaction inlet and the working fluid vaporization outlet of the first gravity-type heat pipe 12 are circulated and connected with the second gravity-type heat pipe 22 through the working fluid exhaust pipe 201 and the working fluid return pipe 202. The fuel cell's tailpipe 5 (60-90°C) is connected to the tailpipe inlet 111. It exchanges heat with the organic phase-change medium in the first gravity-type heat pipe 12 and is cooled. The organic phase-change medium absorbs heat and vaporizes before entering the second gravity-type heat pipe 22. The vaporized organic phase-change medium in the second gravity-type heat pipe 22 exchanges heat with the cooling water flowing through the cooling water channel, liquefies, and reflows into the first gravity-type heat pipe 12, achieving fluid recycling. The heated cooling water is then supplied to the user.

[0067] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like to indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation to the present invention.

[0068] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature specified as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of this utility model, "plurality" means at least two, such as two, three, etc., unless otherwise specifically defined.

[0069] In this utility model, unless otherwise specified or limited, the terms "installed," "connected," "connect," "fixed," etc. should be understood in a broad sense. For example, they can refer to fixed connection, detachable connection, or integration; mechanical connection, electrical connection, or communication; direct connection or indirect connection through an intermediate medium; internal communication between two elements or interaction between two elements, unless otherwise specified. For those skilled in the art, the specific meanings of the above terms in this utility model can be understood according to specific circumstances.

[0070] In the present invention, unless otherwise expressly specified or limited, when a first feature is "above" or "below" a second feature, it may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediary. Furthermore, when a first feature is "above," "above," or "above" a second feature, it may mean that the first feature is directly above or diagonally above the second feature, or simply means that the first feature is at a higher level than the second feature. When a first feature is "below," "below," or "below" a second feature, it may mean that the first feature is directly below or diagonally below the second feature, or simply means that the first feature is at a lower level than the second feature.

[0071] In the present invention, the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" mean that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art can combine and combine different embodiments or examples described in this specification and the features of different embodiments or examples without contradiction.

[0072] Although the embodiments of the present invention have been shown and described above, it can be understood that the above embodiments are illustrative and cannot be understood as limitations on the present invention. Ordinary technicians in this field can change, modify, replace and modify the above embodiments within the scope of the present invention.

Claims

1. A separate heat exchanger, characterized in that: include: A high-temperature heat exchanger having a tail exhaust condensation channel and a working medium gasification channel capable of exchanging heat, wherein the tail exhaust inlet of the tail exhaust condensation channel is used to communicate with the tail exhaust pipe of the battery; A low-temperature heat exchanger, the low-temperature heat exchanger being separately arranged from the high-temperature heat exchanger, the low-temperature heat exchanger having a cooling water channel and a working fluid liquefaction channel capable of exchanging heat, the cooling water channel being communicable with external cooling water to liquefy the organic phase-change working fluid in the working fluid liquefaction channel, the working fluid liquefaction channel and the working fluid vaporization channel being communicated with each other via a pipeline to form a working fluid cooling circulation channel, an organic phase-change working fluid circulating in the working fluid cooling circulation channel, the boiling point of the organic phase-change working fluid being lower than a preset temperature; A tail liquid collecting device is connected to the tail liquid outlet of the tail condensation channel to collect cooling water in the tail gas.

2. The separate heat exchanger according to claim 1, characterized in that The high-temperature heat exchanger includes a high-temperature shell and a first gravity-type heat pipe arranged in the high-temperature shell. The working medium vaporization channel is formed in the first gravity-type heat pipe, and the cavity between the inner wall surface of the high-temperature shell and the outer wall surface of the first gravity-type heat pipe forms the tail exhaust condensation channel.

3. The separate heat exchanger according to claim 2, characterized in that: The low-temperature heat exchanger includes a low-temperature shell and a second gravity-type heat pipe arranged in the low-temperature shell. The working medium liquefaction channel is formed in the second gravity-type heat pipe, and the cavity between the inner wall surface of the low-temperature shell and the outer wall surface of the second gravity-type heat pipe forms the cooling water channel.

4. The separate heat exchanger according to claim 3, characterized in that The high-temperature tube shell and the low-temperature tube shell both include a vacuum insulation layer and a liquid wick. The liquid wick is attached to the inner wall surface of the vacuum insulation layer. The liquid wick is arranged on the inner wall surface of the vacuum insulation layer. The vacuum insulation layer and the outer wall surface of the second gravity-type heat pipe form the cooling water channel.

5. The separate heat exchanger according to claim 3, characterized in that: Each of the first gravity-type heat pipe and the second gravity-type heat pipe includes a plurality of sections of corrugated pipes connected end to end in sequence.

6. The separate heat exchanger according to claim 3, characterized in that: The high-temperature tube shell has a tail drain inlet, a gas outlet, and a tail drain liquid port connected to the tail drain condensation channel. The tail drain liquid port is arranged at the bottom of the high-temperature tube shell. The tail drain inlet and the gas outlet are arranged opposite to each other in the longitudinal direction of the high-temperature heat exchanger. The tail drain liquid port and the gas outlet are both connected to the tail liquid collecting device through a pipeline. The second gravity-type heat pipe has an air inlet and a working medium discharge port. The air inlet is arranged at the top of the second gravity-type heat pipe, and the working medium discharge port is arranged at the bottom of the second gravity-type heat pipe.

7. The separate heat exchanger according to claim 1, characterized in that It also includes a three-way valve and a liquid inlet pipe, one end of the liquid inlet pipe is connected to the liquid inlet of the cooling water channel, and the other end of the liquid inlet pipe can be switchably connected to the tail discharge port of the tail liquid collecting device and the external cooling water source through the three-way valve.

8. The separate heat exchanger according to any one of claims 1 to 7, characterized in that: The tail liquid collecting device includes a tail drain water collecting tank, a top cover plate and a steam condensing pipe. The top cover plate is provided on the tail drain water collecting tank. The top cover plate has a cover plate exhaust port. The tail drain liquid port of the tail drain condensation channel is connected with the tail drain water collecting tank. The steam condensing pipe is connected with the tail drain water collecting tank through the cover plate exhaust port. The liquid discharge port of the tail drain water collecting tank can be connected with an external heating system and / or the cooling water channel.

9. The separate heat exchanger according to claim 8, characterized in that The tail drain water collecting tank is provided with an insulation layer, a liquid level gauge and a one-way valve. The tail drain water collecting tank is connected to the cooling water channel through a liquid return pipe. The one-way valve is provided on the liquid return pipe and responds to the liquid level gauge signal. And / or, the steam condenser is a spiral coil, and the lower end of the spiral coil is connected to the upper end of the tail drain water collecting tank; and / or, the top cover is an arc-shaped top cover.

10. A fuel cell cogeneration system, characterized in that: It comprises a fuel cell and a separate heat exchanger according to any one of claims 1 to 9, wherein the tail exhaust pipe of the fuel cell is connected to the tail exhaust condensation channel to cool the tail exhaust.

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