Electrochemical energy conversion apparatus and power generation apparatus comprising same

Abstract

The present invention relates to the field of electrochemistry. Disclosed are an electrochemical energy conversion apparatus and a power generation apparatus comprising same. The electrochemical energy conversion apparatus comprises a temperature equalization cover, an electric stack set, insulating components, a second fluid inlet pipeline, and a second fluid outlet pipeline. A first fluid needed in an electrochemical energy conversion reaction process does not need to be inputted and discharged by means of a first fluid pipeline, so that the overall structure of the electrochemical energy conversion apparatus is simplified, and it is easy to repair and disassemble the electric stack. In addition, due to the existence of the temperature equalization cover, the discharged first fluid can be fully in contact with a cover body of the temperature equalization cover and conduct heat to a first cavity by means of the cover body, and therefore a good temperature equalization effect on the first fluid inside the electrochemical energy conversion apparatus is achieved, so that the first fluid entering the temperature equalization cover and the first fluid discharged from the temperature equalization cover after participating in the reaction have similar or the same temperature, and further, a temperature difference between the first cavity and a second cavity is reduced, and the performance attenuation and damage of the electric stack caused by local thermal expansion are suppressed.

Description

An electrochemical energy conversion device and a power generation device including the same Technical Field

[0001] The present invention relates to the field of electrochemical technology, and in particular to an electrochemical energy conversion device and a power generation device comprising the same. Background Art

[0002] The mutual conversion between electrical energy and chemical energy is achieved through a variety of electrochemical energy conversion devices, such as fuel cells and electrolyzers. Common fuel cells include alkaline fuel cells (AFC), phosphoric acid fuel cells (PAFC), molten carbonate fuel cells (MCFC), proton exchange membrane fuel cells (PEMFC), direct methanol fuel cells (DMFC), solid oxide fuel cells (SOFC), etc. Common electrolyzers include alkaline electrolyzers (AWE), proton exchange membrane water electrolyzers (PEMWE), anion exchange membrane water electrolyzers (AEMWE) and solid oxide electrolyzers (SOEC), etc.

[0003] Solid oxide fuel cells (SOFCs) and solid oxide electrolyzers (SOECs) are collectively referred to as solid oxide cells (SOCs). Solid oxide cells (SOCs) are advanced electrochemical energy storage and conversion devices with broad application prospects in clean energy generation and CO2 conversion. A solid oxide fuel cell (SOFC) is an energy conversion device that directly converts the chemical energy stored in fuel and oxidant into electrical energy. Its high operating temperature, typically between 700 and 1000°C, allows it to simultaneously generate electricity and utilize waste heat for combined heat and power generation, achieving energy efficiency as high as 90%. A solid oxide electrolyzer (SOEC) is an electrochemical energy conversion device that converts electrical and thermal energy into chemical energy. Its reaction is the reverse reaction of a solid oxide fuel cell. As one of the main technologies for hydrogen production by water electrolysis today, SOECs typically operate at 700-850°C and achieve electrolysis efficiencies of 85% to 95%.

[0004] Existing electrochemical energy conversion devices usually have multiple fuel cells arranged in a certain distribution pattern. However, the fuel cells of existing electrochemical energy conversion devices usually introduce and exhaust airflow through gas pipelines. The overall pipeline structure is complex, which is not conducive to the maintenance and replacement of the fuel cell stack. In addition, there is a certain temperature difference between the introduced and exhausted gases, and the internal temperature is uneven. The resulting local thermal expansion will cause the fuel cell stack performance to decay rapidly and even cause damage to the fuel cell stack.

[0005] Summary of the Invention

[0006] The object of the present invention is to provide an electrochemical energy conversion device.

[0007] In order to achieve the above objectives, the first aspect of the present invention provides an electrochemical energy conversion device, comprising:

[0008] A temperature-uniform cover having an accommodating cavity formed therein, the temperature-uniform cover being made of a heat-conducting material and having a first fluid inlet and a first fluid exhaust port;

[0009] A battery stack group formed by arranging at least one battery stack is disposed in the accommodation cavity, wherein the battery stack is formed with a first fluid flow channel;

[0010] An insulating component is provided between the battery stack and the temperature-isolating cover;

[0011] In which, the battery stack group and the insulating component jointly divide the accommodating cavity into multiple cavities, and the multiple cavities include a first cavity and a second cavity, the first cavity is connected to the first fluid inlet, the second cavity is connected to the first fluid exhaust port, and the first cavity and the second cavity are connected through the first fluid flow channel.

[0012] In some embodiments of the present application, the thermal conductivity of the temperature-homogenizing cover is 1 to 40 W / m·K.

[0013] In some embodiments of the present application, the temperature-maintaining cover is made of one or more materials selected from SUS 310S, SUS 310, SUS 444, SUS 430, and SUS 316.

[0014] In some embodiments of the present application, the thermal conductivity of the insulating component is 1 to 30 W / m·K.

[0015] In some embodiments of the present application, the temperature-homogenizing cover includes multiple walls surrounding the accommodating cavity, the area of ​​the wall with the first fluid inlet is B, the area of ​​the first fluid inlet is A, and A / B=0.01~0.95.

[0016] In some embodiments of the present application, the distance between the bottom surface of the battery stack group and the inner bottom surface of the temperature-isolating cover is C, the distance between the top surface of the battery stack group and the inner top surface of the temperature-isolating cover is D, the distance between the side surface of the battery stack group and the corresponding inner side surface of the temperature-isolating cover is E, and the thickness of the insulating component is F, then C / F=1~4, D / F=1~4, E / F=1~2.

[0017] It can be understood that the side surfaces of the battery stack group and the cavity do not correspond to each other; the battery stack has a main surface corresponding to the cavity, and the outlet and the inlet of the first fluid flow channel are located on the main surface.

[0018] In some embodiments of the present application, sealing cotton is further included, and the sealing cotton is arranged between the insulating component and the temperature uniform cover.

[0019] In some embodiments of the present application, the temperature-homogenizing cover is provided with a second fluid inlet hole and a second fluid outlet hole;

[0020] The electrochemical energy conversion device further includes a second fluid inlet conduit and a second fluid outlet conduit;

[0021] The first cavity is provided with a second fluid inlet pipe, the second fluid inlet pipe is connected to the temperature-uniform cover through the second fluid inlet hole, and the second fluid inlet channel is connected to the fuel cell stack;

[0022] The second fluid outlet pipe is provided in the second cavity. The second fluid outlet pipe is connected to the temperature-uniform cover through the second fluid outlet hole, and the second fluid outlet channel is connected to the fuel cell stack.

[0023] In some embodiments of the present application, the temperature-regulating cover includes an end surface, the projection surface of the first cavity on the end surface is N1, the long side of the projection surface N1 is L1, the short side of the projection surface N1 is W1, the projection point of the axis of the second fluid inlet pipe on the end surface is O1, and the distance between point O1 and the long side L1 of the projection surface N1 close to the fuel cell stack is X1, then 0.1W1≤X1≤0.9W1;

[0024] and / or,

[0025] The temperature-uniform cover includes an end face, the projection surface of the second cavity on the end face is N2, the long side of the projection surface N2 is L2, the short side of the projection surface N2 is W2, the projection point of the axis of the second fluid outlet pipe on the end face is O2, and the distance between point O2 and the long side L2 of the projection surface N2 close to the fuel cell stack group is X2, then 0.1W2≤X2≤0.9W2.

[0026] In some embodiments of the present application, the temperature uniform cover includes an end surface, the projection surface of the first cavity on the end surface is N1, the short side of the projection surface N1 is W1, the longest diagonal length of the projection surface N1 is Z1, the projection point of the axis of the second fluid inlet pipe on the end surface is O1, the projection of the center point of the first fluid inlet on the end surface is point P1, and the distance between point P1 and point O1 is Y1, then 0.1W1≤Y1≤0.85Z1;

[0027] and / or,

[0028] The temperature uniformity cover includes an end surface, the projection surface of the second cavity on the end surface is N2, the short side of the projection surface N2 is W2, the longest diagonal length of the projection surface N2 is Z2, the projection point of the axis of the second fluid outlet pipe on the end surface is O2, the projection of the center point of the first fluid exhaust port on the end surface is point P2, the distance between point P2 and point O2 is Y2, then 0.1W2≤Y2≤0.85Z2.

[0029] In some embodiments of the present application, the stack group includes a plurality of stacks, at least some of the adjacent two stacks are arranged in series, and the positive and negative poles of the two stacks arranged in series are arranged in reverse, and the insulating component is arranged between the two adjacent stacks.

[0030] It can be understood that the cavity is not formed between two adjacent battery stacks in the same row of battery stack groups, but the cavity can be formed between battery stack groups in different rows.

[0031] In some embodiments of the present application, an insulating section is provided on both the second fluid inlet pipe and the second fluid outlet pipe.

[0032] In some embodiments of the present application, a power-introduction assembly is further included, which includes a conductive part and an electrical connection part. The conductive part is arranged between the insulating part and the battery stack group and is electrically connected to the battery stack group. The electrical connection part passes through the temperature-isolating cover and the insulating part and is connected to the conductive part.

[0033] The present invention provides an electrochemical energy conversion device, which has the following advantages compared with the prior art:

[0034] The electrochemical energy conversion device provided by the present invention includes a temperature-isolating cover, a stack group containing at least one stack, and an insulating component. The temperature-isolating cover, the stack group, and the insulating component cooperate with each other to form a plurality of cavities including a first cavity and a second cavity inside the temperature-isolating cover. The first fluid required for the reaction of the electrochemical energy conversion device enters the first cavity through the first fluid inlet, then flows into the first fluid flow channel and enters each single cell in the stack to react. The cathode exhaust gas after the reaction flows into the second cavity through the first fluid flow channel, and then is discharged through the first fluid exhaust port. That is, the first fluid required for the reaction of the electrochemical energy conversion device does not need to be input and discharged through the first fluid pipeline, which simplifies the overall structure of the electrochemical energy conversion device. It is more convenient to inspect and disassemble the battery stack; secondly, the temperature-isolating cover seals the electrochemical energy conversion device as a whole, forming a good sealing environment to prevent leakage of the first fluid or the second fluid. The temperature of the first fluid discharged from the battery stack unit is higher than the temperature of the first fluid input. Due to the existence of the temperature-isolating cover, the discharged first fluid can fully contact the cover body of the temperature-isolating cover and transfer heat to the first cavity through the cover body, thereby achieving a good temperature-isolating effect on the first fluid inside the electrochemical energy conversion device, so that the first fluid entering the temperature-isolating cover and the first fluid discharged from the temperature-isolating cover after participating in the reaction have a temperature close to or the same, thereby reducing the temperature difference between the first cavity and the second cavity, and suppressing the battery stack performance degradation and damage caused by local thermal expansion. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] FIG1 is a schematic diagram of the overall structure of an electrochemical energy conversion device according to an embodiment of the present invention;

[0036] FIG2 is a schematic structural diagram of an electrochemical energy conversion device according to an embodiment of the present invention;

[0037] FIG3 is a bottom view schematically illustrating an electrochemical energy conversion device according to an embodiment of the present invention;

[0038] FIG4 is a schematic top view of an electrochemical energy conversion device according to an embodiment of the present invention;

[0039] FIG5 is a schematic cross-sectional view along the XX direction in FIG4 ;

[0040] FIG6 is a schematic structural diagram of an electrochemical energy conversion device according to an embodiment of the present invention (partial temperature hood omitted);

[0041] FIG7 is a front view schematic diagram of the structure of the electrochemical energy conversion device (partial temperature hood omitted) according to an embodiment of the present invention;

[0042] FIG8 is a schematic cross-sectional view along the YY direction in FIG7 ;

[0043] FIG9 is a schematic cross-sectional view along the ZZ direction in FIG7 .

[0044] In the figure: 1. Temperature-averaging cover; 11. First fluid air inlet; 12. First fluid air outlet; 13. First cavity; 14. Second cavity; 15. End face; 16. Second fluid air inlet; 17. Second fluid air outlet; 200. Fuel cell group; 20. Fuel cell; 2. Fuel cell unit; 21. Fuel cell unit top plate; 22. Multiple single cells; 23. Fuel cell unit bottom plate; 3. Insulating component; 4. Sealing cotton; 5. Second fluid air inlet pipe; 6. Second fluid air outlet pipe; 61. Fluid equalizing device; 71. Conductive part; 72. Electrical connecting part. DETAILED DESCRIPTION

[0045] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0046] It should be understood that in the description of this application, the terms "center", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on this application. The terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated, that is, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In addition, unless otherwise specified, "multiple" means two or more.

[0047] It should be noted that, in the description of this application, unless otherwise expressly specified or limited, the terms "installed," "connected," and "connected" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium; and they can refer to internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in this application based on the specific circumstances.

[0048] As shown in FIG1 , FIG6 and FIG7 , an embodiment of the present invention provides an electrochemical energy conversion device, which includes a temperature-isolating cover 1 , a stack group 200 and an insulating component 3 .

[0049] Referring to Figures 2 and 3, a housing cavity is formed inside the temperature-averaging cover 1. The temperature-averaging cover 1 is made of a thermally conductive material and has a first fluid inlet 11 and a first fluid exhaust 12. Preferably, the first fluid inlet 11 and the first fluid exhaust 12 are arranged on the same end surface 15 of the temperature-averaging cover 1. Of course, the first fluid inlet 11 and the first fluid exhaust 12 can also be arranged on different end surfaces 15, or on the side of the temperature-averaging cover 1. Preferably, the temperature-averaging cover 1 is made of one or more stainless steel materials selected from SUS 310S, SUS 310, SUS 444, SUS 430, and SUS 316.

[0050] In order to better achieve the temperature equalization effect of the temperature-equalizing cover 1, optionally, in this embodiment, the thermal conductivity of the temperature-equalizing cover 1 is 1 to 40 W / m·k. Under power generation conditions, if the thermal conductivity of the temperature-equalizing cover 1 is less than 1 W / m·k, the heat near the first fluid exhaust port 12 of the temperature-equalizing cover 1 cannot be transferred to the first fluid air inlet 11 of the temperature-equalizing cover 1 in a timely manner, so that the temperature difference between the inlet and outlet of the temperature-equalizing cover 1 and the inlet and outlet of the stack unit 2 increases, resulting in a reduction in the service life of the stack unit 2; under power generation conditions, if the thermal conductivity of the temperature-equalizing cover 1 is greater than 40 W / m·k, the heat of the electrochemical energy conversion device will be released too much into the surrounding environment. At this time, more heat is required to maintain the operation of the electrochemical energy conversion device, which increases the energy consumption of the entire electrochemical energy conversion device system. At the same time, if a plurality of electrochemical energy conversion devices are arranged in a compact connection, the temperature fields of similar electrochemical energy conversion devices will affect each other, increasing the risk of abnormal operation of the electrochemical energy conversion device.

[0051] Referring to Figure 7, the stack group 200 is arranged in the accommodating cavity. The stack group 200 is composed of two stacks 20 arranged in an arrangement. The stack 20 is formed with a first fluid flow channel (not shown in the figure) for the first fluid to flow through. A plurality of stack units 2 are stacked up and down to form the stack 20. The stack 20 can also be composed of a single stack unit 2. Specifically, each stack unit 2 includes a stack unit bottom plate 23, a plurality of single cells 22 and a stack unit top plate 21. The plurality of single cells 22 are arranged between the stack unit bottom plate 23 and the stack unit top plate 21 and are connected to the two. On the one hand, the stack unit bottom plate 23 and the stack unit top plate 21 are conducive to the positioning of the electrochemical energy conversion device system during assembly, and on the other hand, they can protect the overall structure of the stack unit 2. In addition, air guide holes can be provided on the stack unit bottom plate 23 or the stack unit top plate 21 to promote the second fluid to pass to each single cell and react.

[0052] It should be understood that in an SOFC, the first fluid is air and the second fluid is fuel gas, while in an SOEC, the first fluid is air and the second fluid is water vapor. The purpose of introducing air into an SOEC is to provide a certain oxygen partial pressure at the start of the reaction and to reduce the oxygen partial pressure in the electrochemical energy conversion device during the reaction, thereby promoting the smooth progress of the reaction and lowering the reaction temperature in the electrochemical energy conversion device.

[0053] Optionally, referring to FIG7 , in this embodiment, the stack unit bottom plate 23, the stack unit top plate 21, and the temperature-regulating cover 1 are made of the same material. Electrochemical energy conversion devices typically operate at an operating temperature of 800-1000°C, at which the metal will undergo thermal expansion. If the material of the temperature-regulating cover 1 is inconsistent with the materials used for the stack unit top plate 21, the stack unit bottom plate 23, and the connecting components, their thermal expansion will not match. Specifically, if the expansion coefficients of the stack unit top plate 21, the stack unit bottom plate 23, and the connecting components are greater than the expansion coefficient of the temperature-regulating cover 1, the stack 20 will hit the temperature-regulating cover 1, causing the latter to deform. If the expansion coefficients of the stack unit top plate 21, the stack unit bottom plate 23 and the connecting components are smaller than the expansion coefficient of the temperature-isolating cover 1, the gap between the temperature-isolating cover 1 and the stack will gradually increase as the temperature rises, and the sealing structure therebetween will fail, causing more reaction gas to flow directly toward the reaction gas outlet instead of passing through the stack 20. In severe cases, the stack 20 will be damaged due to insufficient reaction gas content.

[0054] Optionally, in this embodiment, the stack group 200 is provided in plurality and each stack group 200 includes at least two stacks 20, two adjacent stacks 20 are arranged in series, and the positive and negative poles of the two stacks 20 arranged in series are arranged in reverse, so that the positive and negative leads of the stack 20 can be located on the same side, which simplifies the design of the electrochemical energy conversion device and facilitates subsequent testing and system assembly. Specifically, two or more stacks 20 can be electrically connected in series through a conductive plate or a conductive wire, and a conductive plate is preferably used. Since the operating temperature of the SOC is very high and the positive and negative poles of the battery pack are in a high temperature area, when a conductive wire is used to achieve electrical contact between the two stacks 20, the conductive wire is prone to failure behaviors such as oxidation and breakage at high temperatures. Therefore, a conductive plate is preferably used to achieve electrical contact between the two stacks 20.

[0055] Optionally, referring to FIG7 , in this embodiment, an insulating component 3 is provided between two adjacent battery stacks 20. Adjacent battery stacks in an electrochemical energy conversion device are relatively close to each other. Without an insulating component 3 between the battery stacks, faults such as short circuits caused by electrical breakdown are very likely to occur. Furthermore, the insulating component 3 is also a necessary component for forming the first cavity 13 and the second cavity 14 in the temperature-regulating cover 1. Otherwise, the first fluid can flow directly between the two battery stacks 20, resulting in no reaction in the battery stacks or extremely low reaction efficiency.

[0056] It should be understood that the number of cavities in the electrochemical energy conversion device is related to the number of rows of the battery group. For example, when the battery group in the electrochemical energy conversion device consists of two battery stacks 20 and the two battery stacks 20 are located in a row, the positive and negative poles of the two battery stacks 20 are set in reverse and are electrically connected in series. There is a first cavity 13 and a second cavity 14 inside the electrochemical energy conversion device. The first fluid required for the electrochemical energy conversion reaction enters the first cavity 13 through the first fluid air inlet 11 set on the temperature equalizing cover 1, and then flows into the first fluid flow channel in the two battery stacks 20 and enters each single cell in the two battery stacks 20 to react, and reversely. The cathode exhaust gas after the reaction flows into the second cavity 14 through the first fluid flow channel in the two battery stacks 20, and is then discharged from the electrochemical energy conversion device through the first fluid exhaust port 12; when the battery stack group in the electrochemical energy conversion device is composed of an even number of battery stacks 20 greater than two and these battery stacks 20 are in the same row, these battery stacks 20 can be all connected in series, with only two positive and negative pole lines led out on the same side. In addition, these even number of battery stacks 20 greater than two can also be connected in series in pairs or partially in series, and then multiple lines are led out from the same side. In the above case, there are still two cavities in the electrochemical energy conversion device, namely a first cavity 13 and a second cavity 14.

[0057] When there are two or more rows of battery stacks in the electrochemical energy conversion device, the total number of cavities is not less than 3, and an intermediate cavity is formed between two adjacent battery stacks. The intermediate cavity can also serve as a first cavity 13 for the first fluid to enter or a second cavity 14 for the first fluid to discharge.

[0058] Optionally, as shown in Figure 5, in this embodiment, the electrochemical energy conversion device further includes a power-introduction component, which includes a conductive portion 71 and an electrical connection portion 72. The conductive portion 71 is the conductive plate mentioned above, which is arranged between the insulating component 3 and the battery stack group 200 and is electrically connected to the battery stack group 200. The electrical connection portion 72 passes through the temperature-isolating cover 1 and the insulating component 3 and is connected to the conductive portion 71. The electrochemical energy conversion device of the present invention includes two or more battery stacks, which not only has a compact structure and high internal space utilization, but also improves the overall power generation efficiency of the electrochemical energy conversion device. In addition, every two battery stacks can be electrically conductive through the conductive plate, which is conducive to leading the electric energy generated by the electrochemical energy conversion device in the same direction, making the overall layout structure more reasonable.

[0059] Referring to Figures 4 and 5, an insulating component 3 is provided between the battery stack group 200 and the temperature-regulating cover 1, and is made of one or more insulating materials selected from ceramic, glass, rubber, and mica. The electrochemical energy conversion device generates high voltage and high current during operation. Providing the insulating component 3 between the temperature-regulating cover 1 and the battery stack group 200 can prevent the battery stack group 200 from leaking electricity and causing safety accidents. At least one of the top, bottom, and side surfaces of the battery stack group 200 near the temperature-regulating cover 1 is close to the temperature-regulating cover 1. Therefore, covering the top, bottom, and / or sides of the battery stack group 200 with the insulating component 3 can prevent safety accidents such as leakage.

[0060] In order to better achieve the temperature uniformity effect, optionally, in this embodiment, the thermal conductivity of the insulating component 3 is 1 to 30 W / m·k. If the thermal conductivity of the insulating component 3 is less than 1 W / m·k, the temperature of the side, bottom and / or top surface of the stack group 200 cannot be transmitted out of the stack group 200 in a timely manner, resulting in a local temperature increase on the side, bottom and / or top surface of the stack group 200, increasing the risk of stack failure; if the thermal conductivity of the insulating component 3 is greater than 30 W / m·k, since the side of the stack group is close to the short side of the temperature uniformity cover 1, the heat transfer rate is fast. Experiments show that this will cause thermal expansion and deformation of the short side of the temperature uniformity cover 1.

[0061] Referring to Figure 8 , a stack group 200 consisting of two stacks 20 and an insulating component 3 together divide the accommodating chamber into a first cavity 13 and a second cavity 14. The first cavity 13 is connected to the first fluid inlet 11, and the second cavity 14 is connected to the first fluid exhaust 12. The first cavity 13 and the second cavity 14 are connected via a first fluid flow channel. Of course, two rows of stack groups and corresponding insulating components 3 can also be used to divide the accommodating chamber into three cavities, or multiple rows of stack groups and corresponding insulating components 3 can be used to divide the accommodating chamber into multiple cavities.

[0062] Based on the above structure, the temperature-regulating cover 1, the battery stack group 200 and the insulating component 3 cooperate with each other to form a first cavity 13 and a second cavity 14 inside the temperature-regulating cover 1. The first fluid required for the electrochemical energy conversion reaction enters the first cavity 13 through the first fluid inlet 11, and then flows into the first fluid flow channel in the battery stack 20 and enters each single cell in the battery stack 20 for reaction. The cathode exhaust gas after the reaction flows into the second cavity 14 through the first fluid flow channel in the battery stack 20, and then is discharged through the first fluid exhaust port 12. When there are multiple rows of battery stack groups that divide the accommodating cavity into multiple cavities containing an intermediate cavity, the first fluid can pass through the above-mentioned intermediate cavity before entering the second cavity 14. That is, the first fluid required for the electrochemical energy conversion reaction does not need to be input and discharged through the first fluid pipeline, which simplifies the overall structure of the electrochemical energy conversion device and makes the maintenance and disassembly of the battery stack 20 more convenient; secondly, the temperature-isolating cover 1 seals the electrochemical energy conversion device as a whole, forming a good sealing environment to prevent leakage of the first fluid or the second fluid. The temperature of the first fluid discharged from the battery stack 20 is higher than the temperature of the input first fluid. Due to the presence of the temperature-isolating cover 1, the discharged first fluid can fully contact the cover body of the temperature-isolating cover 1 and transfer heat to the first cavity 13 through the cover body, thereby achieving a good temperature-isolating effect on the first fluid inside the electrochemical energy conversion device, so that the first fluid entering the temperature-isolating cover 1 and the first fluid discharged from the temperature-isolating cover 1 after participating in the reaction have a temperature close to or the same as the first fluid, thereby reducing the temperature difference between the first cavity 13 and the second cavity 14, and suppressing the battery stack performance degradation and damage caused by local thermal expansion.

[0063] Optionally, as shown in FIG8 , in this embodiment, the temperature-regulating cover includes a plurality of walls surrounding the accommodating cavity, and the area of ​​the wall on which the first fluid inlet 11 is provided is B, the area of ​​the first fluid inlet 11 is A, and A / B=0.01 to 0.95. If A / B is less than 0.01, the flow rate of the first fluid entering the electrochemical energy conversion device is relatively high, which will cause the first fluid to tend to be supplied to the stack unit 2 away from the first fluid inlet 11, while the intake amount of the first fluid of the stack unit 2 close to the first fluid inlet 11 will be reduced, affecting the uniformity of the first fluid distribution in the electrochemical energy conversion device. In severe cases, it will also cause the first fluid to be over-utilized in the stack unit close to the first fluid inlet 11, damaging the stack unit; if A / B is greater than 0.95, it will increase the difficulty of sealing the electrochemical energy conversion device with the system platform.

[0064] Optionally, as shown in FIG3 , in this embodiment, the shape of the first fluid inlet 11 can be any regular or irregular shape, such as a rectangle, a circle, a triangle, a parallelogram, or a regular polygon, preferably a circular shape. The shape of the first fluid inlet 11 affects the velocity of the first fluid when entering the temperature-regulating cover 1. To reduce pressure loss, a circular first fluid inlet 11 is preferably used.

[0065] Optionally, in this embodiment, let C be the distance between the bottom surface of the stack group 200 and the inner bottom surface of the temperature-regulating cover 1, D be the distance between the top surface of the stack group 200 and the inner top surface of the temperature-regulating cover 1, E be the distance between the side surface of the stack group 200 and the corresponding inner side surface of the temperature-regulating cover 1, and F be the thickness of the insulating component 3. Then, C / F = 1 to 4, D / F = 1 to 4, and E / F = 1 to 2. Taking C / F as an example (other similarities apply), if C / F is less than 1, the thickness of the insulating component 3 is relatively large, which increases the cost of using the insulating material, reduces economic benefits, and affects the assembly of other components with the stack group 200. If C / F is greater than 4, the thickness of the insulating component 3 is relatively small. During high-temperature operation, impurity ions in the insulating material will gradually be enriched at both ends under the action of the electric field. The insulation capacity decreases with the increase of working time. In severe cases, insulation failure may occur, resulting in breakdown between the stack group 200 and the temperature-regulating cover 1. Among them, when the temperature-regulating cover is rectangular, the side of the stack group 200 is the side corresponding to the short side of the stack group 200 close to the temperature-regulating cover 1. There are only insulating components and some insulating and heat-insulating fillers between the side of the stack group 200 close to the short side of the temperature-regulating cover and the inner side corresponding to the temperature-regulating cover 1, so the ratio is 1 to 2. There are also some other components such as electrical connection plates, lead plates, gas guide components, etc. between the top and bottom surfaces of the stack group and the temperature-regulating cover, so the ratio range is relatively large, reaching 1 to 4.

[0066] Optionally, as shown in FIG5 , in this embodiment, the electrochemical energy conversion device further includes a sealing cotton 4, which is disposed between the insulating component 3 and the temperature-isolating cover 1. Therefore, inserting the sealing cotton 4 between the insulating component 3 and the temperature-isolating cover 1 can, on the one hand, strengthen the overall sealing of the electrochemical energy conversion device and prevent leakage of the second fluid and the first fluid; on the other hand, it can fill the gap between the insulating component 3 and the temperature-isolating cover 1, preventing the insulating component 3 from shaking or dislocating, and providing a certain buffering effect for the battery stack 200 in the electrochemical energy conversion device.

[0067] Optionally, as shown in Figures 3 and 9, in this embodiment, the temperature-regulating cover 1 is provided with a second fluid inlet hole 16 and a second fluid outlet hole 17. The electrochemical energy conversion device also includes a second fluid inlet pipe 5 and a second fluid outlet pipe 6. A second fluid inlet pipe 5 is provided in the first cavity 13, and the second fluid inlet pipe 5 is connected to the temperature-regulating cover 1 through the second fluid inlet hole 16, and the second fluid inlet pipe 5 is connected to the battery stack 20. A second fluid outlet pipe 6 is provided in the second cavity 14, and the second fluid outlet pipe 6 is connected to the temperature-regulating cover 1 through the second fluid outlet hole 17, and the second fluid outlet pipe 6 is connected to the battery stack 20. The second fluid inlet pipe 5 and the second fluid outlet pipe 6 include a main pipe and a plurality of branch pipes. The main pipe is connected to the temperature-regulating cover through the second fluid inlet hole 16 / the second fluid outlet hole 17, and is connected to the second fluid flow channel in the battery stack unit 2 through each branch pipe. The second fluid enters the various branch pipes connected to the main pipe of the second fluid inlet pipe 5, and then is transported to each level of the stack unit 2 in the stack 20 through the various branch pipes. After the second fluid participates in the reaction in the electrochemical energy conversion device, it flows into the main pipe of the second fluid outlet pipe 6 through the various branch pipes of the second fluid outlet pipe 6, and flows out of the electrochemical energy conversion device. Preferably, an insulating section is provided on both the second fluid inlet pipe 5 and the second fluid outlet pipe 6. The insulating section is located on the second fluid inlet pipe 5 and the second fluid outlet pipe 6, which can insulate the second fluid inlet pipe 5 and the second fluid outlet pipe 6 as a whole, greatly improving the safety performance of the power generation system of the electrochemical energy conversion device.

[0068] Optionally, as shown in FIG6 , in this embodiment, the branch pipe is provided with a fluid equalizing device 61 , which has a second fluid exhaust channel and a second fluid inlet channel inside. The stack unit bottom plate 23 or the stack unit top plate 21 has a second fluid inlet port and a second fluid outlet port for the stack unit. The second fluid exhaust channel is connected to the second fluid inlet port of the stack unit, and the second fluid inlet channel is connected to the second fluid outlet port of the stack unit. Preferably, the end of the fluid equalizing device 61 away from the second fluid inlet channel and the second fluid exhaust channel is sealed. Based on this, the second fluid enters each fluid equalizing device 61 through the main pipe of the second fluid inlet pipe 5, and enters the second fluid inlet port of the stack unit in the top plate 21 of the stack unit or the bottom plate 23 of the stack unit through the second fluid exhaust channel of the fluid equalizing device 61, thereby entering the stack unit to participate in the electrochemical energy conversion reaction. The second fluid tail gas after the reaction enters the second fluid inlet channel of the fluid equalizing device 61 through the second fluid outlet port of the stack unit in the top plate 21 of the stack unit or the bottom plate 23 of the stack unit, and enters the main pipe of the second fluid outlet pipe 6 through the second fluid inlet channel. The design of providing a second fluid inlet / exhaust channel at one end of the fluid equalizing device 61 and completely sealing the other end can ensure that the amount of second fluid delivered to each level of the stack unit through the fluid equalizing device 61 is relatively uniform, thereby making the difference in the amount of second fluid entering each single cell smaller, thereby improving the utilization rate of the second fluid.

[0069] Optionally, as shown in FIG8 , in this embodiment, this embodiment includes the following implementation modes:

[0070] (1) The temperature-uniform cover 1 includes an end surface 15, a second fluid inlet hole 16 is provided on the end surface 15, a projection surface of the first cavity 13 on the end surface 15 is N1, a long side of the projection surface N1 is L1, a short side of the projection surface N1 is W1, a projection point of the axis of the second fluid inlet pipe 5 on the end surface 15 is O1, and a distance between point O1 and the long side L1 of the projection surface N1 close to the stack is X1, then 0.1W1≤X1≤0.9W1;

[0071] (2) The temperature-uniform cover 1 includes an end surface 15, a second fluid outlet hole 17 is provided on the end surface 15, a projection surface of the second cavity 14 on the end surface 15 is N2, a long side of the projection surface N2 is L2, a short side of the projection surface N2 is W2, a projection point of the axis of the second fluid outlet pipe 6 on the end surface 15 is O2, and a distance between the point O2 and the long side L2 of the projection surface N2 close to the stack is X2, then 0.1W2≤X2≤0.9W2;

[0072] (3) The temperature-uniform cover 1 includes an end surface 15, and the second fluid inlet hole 16 and the second fluid outlet hole 17 are both opened on the end surface 15. The projection surface of the first cavity 13 on the end surface 15 is N1, the long side of the projection surface N1 is L1, and the short side of the projection surface N1 is W1. The projection point of the axis of the second fluid inlet pipe 5 on the end surface 15 is O1, and the distance between point O1 and the long side L1 is X1, then 0.1W1≤X1≤0.9W1. The projection surface of the second cavity 14 on the end surface 15 is N2, the long side of the projection surface N2 is L2, and the short side of the projection surface N2 is W2. The projection point of the axis of the second fluid outlet pipe 6 on the end surface 15 is O2, and the distance between point O2 and the long side L2 is X2, then 0.1W2≤X2≤0.9W2.

[0073] Since the second fluid inlet pipe 5 and the second fluid outlet pipe 6 are electrically connected to the battery stack 20 through the fluid equalizing device 61, and the insulating component 3 is not provided on the side of the battery stack 20 opposite to the cavity, it is necessary to consider that there is a sufficient safety distance between the second fluid inlet pipe 5 and the side where the long side of the first cavity 13 is located, and there is a sufficient safety distance between the second fluid outlet pipe 6 and the side where the long side of the second cavity 14 is located. When X1 is less than 0.1W or greater than 0.9W, the first fluid inlet pipe 5 is too close to the side where the long side of the first cavity 13 is located, and a short circuit due to electrical breakdown is likely to occur. When X2 is less than 0.1W or greater than 0.9W, the second fluid outlet pipe 6 is too close to the side where the long side of the second cavity 14 is located, and a short circuit due to electrical breakdown is also likely to occur.

[0074] Optionally, as shown in FIG8 , in this embodiment, the temperature uniform cover includes an end surface, a projection surface of the first cavity on the end surface is N1, a short side of the projection surface N1 is W1, a longest diagonal length of the projection surface N1 is Z1, a projection point of the axis of the second fluid inlet pipe on the end surface is O1, a projection point of the center point of the first fluid inlet on the end surface is P1, a distance between P1 and O1 is Y1, and 0.1W1≤Y1≤0.85Z1;

[0075] and / or,

[0076] The temperature uniformity cover includes an end surface, the projection surface of the second cavity on the end surface is N2, the short side of the projection surface N2 is W2, the longest diagonal length of the projection surface N2 is Z2, the projection point of the axis of the second fluid outlet pipe on the end surface is O2, the projection of the center point of the first fluid exhaust port on the end surface is point P2, the distance between point P2 and point O2 is Y2, then 0.1W2≤Y2≤0.85Z2.

[0077] In the present invention, when the first fluid enters the fuel cell stack 20 through the first fluid inlet 11 and the first cavity 13, the second fluid inlet pipe 5 is wrapped; when the first fluid is discharged from the fuel cell stack 20 and flows to the first fluid exhaust port 12 through the second cavity 14, the second fluid outlet pipe 6 is wrapped, thereby greatly reducing the temperature difference between the first fluid and the second fluid when entering and exiting the fuel cell stack 20. Y1 equals 0.1W, which is the theoretical shortest distance between the center of the first fluid inlet 11 and the center of the second fluid inlet pipe 5, and Y2 equals 0.1W, which is the theoretical shortest distance between the center of the first fluid exhaust port and the center of the second fluid outlet pipe 6. If Y1 is less than 0.1W, the second fluid inlet pipe 5 is too close to the temperature hood 1, which is prone to electrical breakdown and safety accidents such as leakage. If Y1 is greater than 0.85Z, the second fluid inlet pipe 5 is far away from the first fluid inlet 11, resulting in poor temperature balancing between the first and second fluids, which is prone to local thermal expansion. If Y2 is less than 0.1W, the second fluid outlet pipe 6 is too close to the temperature equalizing cover 1, which is prone to electrical breakdown and may lead to safety accidents such as leakage. If Y2 is greater than 0.85Z, the second fluid outlet pipe 6 is far away from the first fluid exhaust port 12, resulting in a poor temperature equalization effect between the first fluid and the second fluid, which may easily lead to local thermal expansion.

[0078] Optionally, in this embodiment, the electrochemical energy conversion device further includes a mounting frame and a heat preservation portion. Connecting multiple electrochemical energy conversion devices in series in the electrochemical energy conversion device system can achieve greater power generation efficiency. At the same time, since the electrochemical energy conversion device requires a higher temperature when working, a heat preservation portion is placed outside the electrochemical energy conversion device for heat insulation, and a mounting frame is assembled outside the heat preservation portion to fix the overall structure consisting of multiple electrochemical energy conversion devices and the heat preservation portion. Based on this, this arrangement can ensure that each electrochemical energy conversion device in the electrochemical energy conversion device system forms an independent temperature environment, and the battery stack in each electrochemical energy conversion device has good temperature uniformity, thereby increasing the life and reliability of the electrochemical energy conversion device system.

[0079] An embodiment of the present invention further provides a power generation device comprising the aforementioned electrochemical energy conversion device. Due to the use of the aforementioned electrochemical energy conversion device, the power generation device has high internal space utilization, a long service life, slow degradation of the battery stack performance, and facilitates repair and replacement of faulty battery stacks.

[0080] In summary, the embodiments of the present invention provide an electrochemical energy conversion device, which is mainly composed of a temperature-isolating cover 1, a stack group 200, and an insulating component 3. Compared with the prior art, the present invention has the following advantages:

[0081] 1. The first fluid required for the reaction of the electrochemical energy conversion device does not need to be input and discharged through the first fluid pipeline, which simplifies the overall structure of the electrochemical energy conversion device and makes it more convenient to inspect and disassemble the battery stack.

[0082] 2. The temperature-equalizing cover seals the entire electrochemical energy conversion device, forming a good sealing environment and preventing leakage of the first fluid or the second fluid. The temperature of the first fluid discharged from the stack is higher than the temperature of the first fluid input. Due to the presence of the temperature-equalizing cover, the discharged first fluid can fully contact the cover body of the temperature-equalizing cover and transfer heat to the first cavity through the cover body, thereby achieving a good temperature-equalizing effect on the first fluid inside the electrochemical energy conversion device, so that the first fluid entering the temperature-equalizing cover and the first fluid discharged from the temperature-equalizing cover after participating in the reaction have a temperature close to or the same, thereby reducing the temperature difference between the first cavity and the second cavity, and suppressing the performance degradation and damage of the stack caused by local thermal expansion.

[0083] 3. A row of battery stacks in the electrochemical energy conversion device contains two or more battery stacks, which not only has a compact structure and high internal space utilization, but also improves the overall power generation efficiency of the electrochemical energy conversion device. In addition, every two battery stacks can be electrically connected through the conductive plate, which is conducive to leading the electric energy generated by the electrochemical energy conversion device out in the same direction, making the overall layout structure more reasonable.

[0084] 4. The electrochemical energy conversion device of the present invention fully utilizes the internal space of the temperature-isolating cover, and the internal components are arranged compactly and reliably. While ensuring low cost, it improves the utilization rate of the second fluid and the power generation efficiency. It is suitable for use in actual production, has strong practicality, and is conducive to standardized production and promotion.

[0085] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and substitutions can be made without departing from the technical principles of the present invention. These improvements and substitutions should also be regarded as the scope of protection of the present invention.

Claims

1. An electrochemical energy conversion device, characterized in that: include: A temperature-average cover, wherein a containing cavity is formed inside the temperature-average cover, the temperature-average cover is made of a heat-conducting material, and the temperature-average cover has a first fluid inlet and a first fluid exhaust port; A battery stack group formed by arranging at least one battery stack is arranged in the accommodation cavity, and the battery stack is formed with a first fluid flow channel; An insulating component, disposed between the battery stack and the temperature-averaging cover; Among them, the battery stack group and the insulating component jointly divide the accommodating cavity into a plurality of cavities, and the plurality of cavities include a first cavity and a second cavity, the first cavity is connected to the first fluid inlet, the second cavity is connected to the first fluid exhaust port, and the first cavity and the second cavity are connected through the first fluid flow channel.

2. The electrochemical energy conversion device according to claim 1, characterized in that: The thermal conductivity of the temperature-averaging cover is 1-40 W / m·k.

3. The electrochemical energy conversion device according to claim 1, characterized in that: The thermal conductivity of the insulating component is 1 to 30 W / m·k.

4. The electrochemical energy conversion device according to claim 1, characterized in that: The temperature-averaging cover includes a plurality of walls surrounding the accommodating cavity. The area of ​​the wall provided with the first fluid inlet is B, the area of ​​the first fluid inlet is A, and A / B=0.01-0.

95.

5. The electrochemical energy conversion device according to claim 1, characterized in that: Let C be the distance between the bottom surface of the battery stack group and the inner bottom surface of the temperature-averaging cover, D be the distance between the top surface of the battery stack group and the inner top surface of the temperature-averaging cover, E be the distance between the side surface of the battery stack group and the corresponding inner side surface of the temperature-averaging cover, and F be the thickness of the insulating component. Then C / F=1~4, D / F=1~4, and E / F=1~2.

6. The electrochemical energy conversion device according to claim 1, characterized in that: The temperature-averaging cover is provided with a second fluid air inlet and a second fluid air outlet; The electrochemical energy conversion device further comprises a second fluid inlet conduit and a second fluid outlet conduit; The first cavity is provided with a second fluid air inlet pipeline, the second fluid air inlet pipeline is connected to the temperature-averaging cover through the second fluid air inlet hole, and the second fluid air inlet pipeline is connected to the fuel cell stack; The second fluid outlet pipe is provided in the second cavity, the second fluid outlet pipe is connected to the temperature-averaging cover through the second fluid outlet hole, and the second fluid outlet pipe is connected to the fuel cell stack.

7. The electrochemical energy conversion device according to claim 6, characterized in that: The temperature-averaging cover includes an end surface, the projection surface of the first cavity on the end surface is N1, the long side of the projection surface N1 is L1, the short side of the projection surface N1 is W1, the projection point of the axis of the second fluid intake pipe on the end surface is O1, the distance between the point O1 and the long side L1 of the projection surface N1 close to the stack group is X1, then 0.1W1≤X1≤0.9W1; and / or, The temperature-averaging cover includes an end face, the projection surface of the second cavity on the end face is N2, the long side of the projection surface N2 is L2, the short side of the projection surface N2 is W2, the projection point of the axis of the second fluid outlet pipe on the end face is O2, the distance between point O2 and the long side L2 of the projection surface N2 close to the battery stack group is X2, then 0.1W2≤X2≤0.9W2.

8. The electrochemical energy conversion device according to claim 6, characterized in that: The temperature-averaging cover includes an end surface, a projection surface of the first cavity on the end surface is N1, a short side of the projection surface N1 is W1, a longest diagonal length of the projection surface N1 is Z1, a projection point of the axis of the second fluid inlet pipe on the end surface is O1, a projection point of the center point of the first fluid inlet on the end surface is P1, a distance between P1 and O1 is Y1, then 0.1W1≤Y1≤0.85Z1; and / or, The temperature-averaging cover includes an end face, the projection face of the second cavity on the end face is N2, the short side of the projection face N2 is W2, the longest diagonal length of the projection face N2 is Z2, the projection point of the axis of the second fluid outlet pipe on the end face is O2, the projection of the center point of the first fluid exhaust port on the end face is point P2, the distance between point P2 and point O2 is Y2, then 0.1W2≤Y2≤0.85Z2.

9. The electrochemical energy conversion device according to claim 1, characterized in that: The battery stack group includes a plurality of battery stacks, at least some of the adjacent two battery stacks are arranged in series, and the positive and negative poles of the two battery stacks arranged in series are arranged in reverse, and the insulating component is arranged between the two adjacent battery stacks.

10. The electrochemical energy conversion device according to claim 1, characterized in that: It also includes a power-introduction component, which includes a conductive part and an electrical connection part. The conductive part is arranged between the insulating component and the battery stack and is electrically connected to the battery stack. The electrical connection part passes through the temperature-isolating cover and the insulating component and is connected to the conductive part.

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