Separated heat exchanger and fuel cell cogeneration system

Abstract

The embodiment of the invention 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 that the heat recovery rate is increased, and the arrangement flexibility is high.

Description

Technical Field

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

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

[0003] The present invention aims to solve one of the technical problems in the related art at least to a certain extent. To this end, an embodiment of the present invention provides a separation heat exchanger. The separation heat exchanger has the advantages of improving heat recovery rate and high layout flexibility.

[0004] An embodiment of the present invention further provides a fuel cell cogeneration system.

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

[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 by 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 to 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 invention 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-changing working medium can circulate in the working medium cooling circulation channel. The boiling point of the organic phase-changing working medium is lower than the preset temperature, so that the tail exhaust pipe of the fuel cell is connected to the tail exhaust condensation channel by the gasification of the organic phase-changing working medium 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-changing working medium in the working medium liquefaction channel. The heated cooling water after heat exchange is discharged from the outlet of the low-temperature working medium to be used and can be supplied to the user end for use, so as to achieve the purpose of heat recovery. The gaseous organic working medium in the working medium cooling circulation channel after the temperature is increased undergoes heat conversion with the low-temperature cooling liquid phase change 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 to complete the circulation of the organic working medium. This heat transfer method is latent heat, which is an efficient heat transfer method. Under the condition of small working fluid flow, the present invention 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 larger 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 fluid 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, and 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 relatively 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 double gravity-type heat pipe, and the working fluid discharge port is arranged at the bottom of the double gravity-type heat pipe.

[0016] In some embodiments, the separate heat exchanger 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.

[0017] In some embodiments, the tail liquid collection device includes a tail drain water collecting tank, a top cover plate and a steam condenser 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 with the tail drain water collecting tank, the steam condenser pipe is connected with the tail drain water collecting tank through the cover plate exhaust port, and 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.

[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 the 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 The flowchart of the separation heat exchanger according to the embodiment of the present invention is shown in FIG.

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

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

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

[0026] Figure 5 Schematic diagram of the structure 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 type 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 discharge 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] 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 A separate heat exchanger and a fuel cell cogeneration system according to an embodiment of the present invention are described.

[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, and 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, 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 by 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 3 is connected with the tail discharge liquid port 113 of the tail discharge condensation channel to collect cooling water in the tail gas.

[0039] The separate heat exchanger of the embodiment of the present invention is connected through the working fluid gasification 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 tail exhaust pipe 5 of the fuel cell is connected to the tail exhaust condensation channel by the gasification of the organic phase-change working fluid 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 outlet of the low-temperature working fluid to be used, which can be supplied to the user end for use, achieving the purpose of heat recovery. The gaseous organic working fluid after the temperature rises in the working fluid cooling circulation channel changes heat with the low-temperature cooling liquid phase to become a liquid organic working fluid. After liquefaction, it flows back into the working fluid gasification channel along the working fluid liquefaction outlet of the heat pipe to complete the circulation of the organic working fluid. This heat transfer method is latent heat, which is an efficient heat transfer method. Under the condition of small working fluid flow, the present invention 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, by separately arranging the high-temperature heat exchanger 1 and the low-temperature heat exchanger 2, the flexibility of the layout of the high-temperature heat exchanger 1 and the low-temperature heat exchanger 2 can be improved. Compared with the heat pipe structure arranged as a whole, 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. 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.

[0043] 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 discharge condensation channel.

[0044] The split 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.

[0045] 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 in the low-temperature shell 21, a working medium liquefaction channel is formed in the second gravity-type heat pipe 22, and a cooling water channel is formed in the cavity between the inner wall surface of the low-temperature shell 21 and the outer wall surface of the second gravity-type heat pipe 22. Similarly, the split heat exchanger of the embodiment of the present invention has the advantages of simple structure and high heat exchange efficiency.

[0046] like Figure 3 and Figure 4 As shown, the high-temperature tube shell 11 and the low-temperature tube shell 21 both 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.

[0047] The split heat exchanger of the embodiment of the present invention divides the high-temperature tube shell 11 and the low-temperature tube shell 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 area to the evaporation area through capillary action, which can significantly improve the heat transfer efficiency of the heat pipe.

[0048] like Figure 5 As shown, each of the first gravity-type heat pipe 12 and the second gravity-type heat pipe 22 includes multiple sections of corrugated tubes connected end to end in sequence. Compared with the straight tube structure design, the corrugated tube structure is conducive to improving the heat exchange efficiency due to the larger heat exchange area, thereby achieving efficient phase change heat transfer between fluids at a small working fluid flow rate. As a result, the flexibility of the heat exchanger layout is further improved.

[0049] 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 relatively arranged 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.

[0050] The separate heat exchanger of the embodiment of the present invention is provided at the bottom of the high-temperature shell 11 through the tail liquid discharge port 113 of the high-temperature shell 11, so that the cooled condensed water can automatically flow back to the tail liquid collecting device 3 under the action of gravity, and no additional delivery pump is required. Therefore, the separate heat exchanger has the advantage of simplifying the equipment setting.

[0051] In addition, the tail discharge inlet 111 and the gas outlet 112 are arranged opposite to each other in the length direction of the high temperature heat exchanger 1, and the tail discharge liquid outlet 113 and the gas outlet 112 are connected to the tail liquid collecting device 3 through a pipeline. This can not only further cool the cooled gas, but also facilitate the collection of condensed water.

[0052] 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.

[0053] The separate heat exchanger of the embodiment of the present invention, by arranging the working fluid discharge port 222 of the second gravity-type heat pipe 22 at its bottom position, facilitates automatic reflux of the liquefied medium therein, and does not require an additional pump body for driving. Therefore, the separate heat exchanger has the advantage of simplifying the equipment setting.

[0054] like Figure 1 As shown, the separation heat exchanger of the embodiment of the present invention 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 discharge port 113 of the tail liquid collecting device 3 and the external cooling water source through the three-way valve. It can be understood that the phase change of the organic phase change working medium in the low-temperature heat exchanger 2 can pass through the external cooling water and the cooling water in the tail liquid collecting device 3.

[0055] The separate heat exchanger of the embodiment of the present invention is provided with a three-way valve and a liquid inlet pipe 4, and the other end of the liquid inlet pipe 4 is switchably connected to the tail discharge port 113 of the tail liquid collecting device 3 and the external cooling water source through the three-way valve, so that the organic phase change working medium can circulate in the working medium cooling circulation channel. Therefore, the separate heat exchanger helps to improve the application flexibility.

[0056] Optionally, low-temperature cooling water of 0°C-10°C may be used. The heated cooling liquid after heat exchange is discharged from the outlet of the low-temperature working medium to be utilized and can be supplied to the user end for use.

[0057] 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.

[0058] The separate heat exchanger of the embodiment of the present invention can collect water vapor and heat in the tail gas by connecting the tail liquid collecting device 3 including the tail water collecting tank 31, the top cover plate 32 and the steam condensing pipe 33, and the tail liquid outlet 113 of the tail condensing channel is connected with the tail water collecting tank 31, and the collected hot water is used for heating and heating, etc. Furthermore, the separate heat exchanger has the advantage of improving the waste heat recovery efficiency.

[0059] like Figure 1 As shown, the tail drain water collecting tank 31 is provided with an insulation layer 311, a liquid level meter 312 and a one-way valve 313. The tail drain water collecting tank 31 is connected to the cooling water channel through a liquid return pipe. The one-way valve 313 is arranged on the liquid return pipe, and the one-way valve 313 responds to the signal of the liquid level meter 312. Therefore, the excess water in the tail drain water collecting tank 31 can be injected into the heating and heating by the liquid level meter 312 and the one-way valve 313.

[0060] like Figure 1 As shown, the steam condenser 33 is a spiral coil, and the lower end of the spiral coil is connected to the upper end of the tail discharge water collecting tank 31. Therefore, the separate heat exchanger of the embodiment of the present invention has the advantage of good condensation effect.

[0061] Optionally, the placement shape of the spiral coil is not limited to horizontal or vertical placement.

[0062] 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 separate heat exchanger has the advantage of saving water.

[0063] The fuel cell cogeneration system of the embodiment of the present invention comprises a fuel cell and a separate heat exchanger according to any one of the above items, and the tail exhaust pipe 5 of the fuel cell is connected to the tail exhaust condensation channel to cool the tail exhaust.

[0064] Therefore, the fuel cell cogeneration system according to the embodiment of the present invention has the advantages of improving the heat recovery rate and high layout flexibility.

[0065] Exemplarily, the high-temperature tube shell 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 tail pipe 5 (60-90°C) of the fuel cell is connected to the tail inlet 111, and is cooled after heat exchange with the organic phase change medium in the first gravity heat pipe 12. The organic phase change medium absorbs heat and is vaporized and enters the second gravity heat pipe 22. The vaporized organic phase change medium of the second gravity heat pipe 22 exchanges heat with the cooling water in the cooling water channel and is liquefied and flows back into the first gravity heat pipe 12 to realize the recycling of the working medium. After the cooling water is heated, the temperature rises and it can be supplied to the user end.

[0066] In the description of the present invention, it is to 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”, etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0067] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0068] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral one; it can be a mechanical connection, an electrical connection, or communication with each other; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0069] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0070] In the present invention, the terms "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" etc. 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 representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the described specific features, structures, materials or characteristics may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0071] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may change, modify, replace and vary 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, wherein the high-temperature heat exchanger has a tail exhaust condensation channel and a working medium gasification channel capable of exchanging heat, and a tail exhaust inlet of the tail exhaust condensation channel is used to communicate with a tail exhaust pipe of a battery; A low-temperature heat exchanger, wherein the low-temperature heat exchanger is separately arranged from the high-temperature heat exchanger, and the low-temperature heat exchanger has a cooling water channel and a working fluid liquefaction channel capable of exchanging heat, wherein the cooling water channel can be communicated with external cooling water so as to liquefy the organic phase-change working fluid in the working fluid liquefaction channel, and the working fluid liquefaction channel and the working fluid gasification channel are communicated through a pipeline to form a working fluid cooling circulation channel, wherein 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 a preset temperature; A tail liquid collecting device is connected to the tail liquid outlet of the tail discharge 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 discharge 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, and 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 discharge inlet, a gas outlet and a tail discharge liquid outlet connected to the tail discharge condensation channel, the tail discharge liquid outlet is arranged at the bottom of the high-temperature tube shell, the tail discharge inlet and the gas outlet are arranged opposite to each other in the length direction of the high-temperature heat exchanger, and the tail discharge liquid outlet 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 fluid discharge port, wherein 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.

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 which is connected to the liquid inlet of the cooling water channel, and the other end of which can be switchably connected to the tail discharge port of the tail liquid collecting device and an 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, wherein 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 condensing 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, and 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 with the cooling water channel through a liquid return pipe. The one-way valve is arranged on the liquid return pipe, and the one-way valve responds to the signal of the liquid level gauge. 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 plate 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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