A self-watering ejector for fuel cells and a method of operation thereof

Abstract

The present application relates to a kind of fuel cell self-water separating ejector, including shell, new hydrogen inlet, circulating hydrogen inlet, ejector outlet and drain, the inside of shell includes circulating hydrogen water separating heat exchange part and injection part;The circulating hydrogen water separating heat exchange part includes new hydrogen chamber and circulating hydrogen chamber, new hydrogen chamber is spaced from top to bottom arrangement with circulating hydrogen chamber;The injection part includes new hydrogen nozzle and rectifier tube, injection part is installed in last circulating hydrogen chamber, the new hydrogen nozzle inlet is communicated with new hydrogen chamber, the new hydrogen nozzle outlet is inserted from rectifier tube inlet, and new hydrogen nozzle outlet and rectifier tube inlet are not sealed with each other.This self-water separating ejector integrates the function of ejector, heat exchanger and water separator in traditional hydrogen fuel cell system, reduces the structure volume of hydrogen fuel cell system, improves the system volume power density, solves the problem that liquid water is generated when circulating hydrogen and low-temperature new hydrogen are mixed in the case of not introducing new external heat source, and reduces system cost.

Description

Technical Field

[0001] This invention relates to the field of fuel cell technology, and specifically to a self-water ejector for fuel cells and its operating method. Background Technology

[0002] Currently, there are two main types of hydrogen circulation components in hydrogen fuel cells: hydrogen circulation pumps and ejectors. Hydrogen circulation pumps have disadvantages such as high noise, large size, high cost, and high power consumption. Unlike hydrogen circulation pumps, ejectors are purely mechanical components that do not require external power. Ejectors have advantages such as low cost, small size, and no parasitic power. Since ejectors have a fixed structure and stable operation, they only need to use the pressure difference of the gas source to meet the working requirements. Therefore, designing more advanced ejectors is the main development direction of hydrogen circulation components in hydrogen fuel cell systems.

[0003] Traditional ejectors often encounter the problem of liquid water formation when high-temperature saturated circulating hydrogen and low-temperature fresh hydrogen converge. This liquid water entering the fuel cell stack causes a single-cell voltage drop at the gas distribution end, and also affects the stack's lifespan. To address this issue, existing technologies primarily focus on two aspects: firstly, using a water separator in conjunction with the ejector to separate the circulating hydrogen before it enters the ejector, removing any liquid water; secondly, employing a heat exchanger or self-heating of the ejector to remove liquid water generated due to the large temperature difference when the low-temperature fresh hydrogen mixes with the circulating hydrogen, thus preventing the low single-cell voltage drop caused by this liquid water entering the stack.

[0004] For hydrogen fuel cell systems, the above methods have two main drawbacks: first, they increase the number of components, reduce the system's volumetric power density, and increase the system cost; second, they require the introduction of external energy, which reduces the system's efficiency.

[0005] In summary, designing an ejector to effectively reduce the production of liquid water from the mixing of recycled hydrogen and fresh hydrogen without adding extra components or introducing new external energy sources is an important research and development direction. Summary of the Invention

[0006] In view of this, the present invention provides a self-water ejector for fuel cells and its working method. The purpose is to design an ejector to effectively reduce the generation of liquid water by mixing recycled hydrogen with fresh hydrogen without adding additional components or introducing new external energy. This solves the problem of low voltage in a single cell at the gas distribution end of the fuel cell stack caused by liquid water entering the stack, which in turn affects the lifespan of the fuel cell stack.

[0007] To achieve the above objectives, the present invention adopts the following technical solution:

[0008] A self-distributing water ejector for a fuel cell includes a housing, a fresh hydrogen inlet, a circulating hydrogen inlet, an ejector outlet, and a drain outlet. The fresh hydrogen inlet and the circulating hydrogen inlet are located at the top of the housing, the ejector outlet is located on the side of the housing, and the drain outlet is located at the bottom of the housing.

[0009] The interior of the housing includes a circulating hydrogen water separation heat exchange section and an ejector section; the circulating hydrogen water separation heat exchange section includes a new hydrogen chamber and a circulating hydrogen chamber, the number of which is equal, and the new hydrogen chamber and the circulating hydrogen chamber are arranged alternately from top to bottom; the ejector section includes a new hydrogen nozzle and a rectifier tube, the ejector section is installed in the last circulating hydrogen chamber, the inlet of the new hydrogen nozzle is connected to the new hydrogen chamber, the outlet of the new hydrogen nozzle is inserted from the inlet of the rectifier tube, and the outlet of the new hydrogen nozzle and the inlet of the rectifier tube are not sealed together.

[0010] Furthermore, the self-diverting water ejector housing is provided with several heat exchange water distribution plates horizontally inside, which divide the housing into several cavities. These cavities are arranged from top to bottom as a new hydrogen cavity and a circulating hydrogen cavity.

[0011] Furthermore, the new hydrogen inlet is connected to the first new hydrogen chamber, and the new hydrogen chambers are connected to each other through a new hydrogen guide tube.

[0012] Furthermore, the circulating hydrogen inlet is connected to the first circulating hydrogen chamber via a circulating hydrogen guide pipe, and the circulating hydrogen chambers are connected to each other via circulating hydrogen guide pipes.

[0013] Furthermore, the new hydrogen nozzle includes a new hydrogen nozzle connecting section and a new hydrogen nozzle outlet section, wherein the new hydrogen nozzle outlet section has a conical tube structure.

[0014] Furthermore, the rectifier tube includes a rectifier tube contraction section and a rectifier tube expansion section, and the ejector outlet is the outlet of the rectifier tube.

[0015] Furthermore, the rectifier tube converging section is coaxially sleeved outside the new hydrogen nozzle outlet section, and the outer side of the new hydrogen nozzle outlet section and the inner side of the rectifier tube converging section form an annular gap, through which the circulating hydrogen after separating liquid water enters the rectifier tube and mixes with the new hydrogen.

[0016] Furthermore, the outlet of the last circulating hydrogen guide tube is connected to a water guide tube, which introduces circulating hydrogen and liquid water into the last circulating hydrogen chamber. The outlet of the water guide tube is much lower than the ejector section.

[0017] Furthermore, a normally closed valve is installed at the drain outlet. When the amount of separated liquid water accumulates to a set standard, the normally closed valve will automatically open and the liquid water will be discharged.

[0018] The present invention also provides a working method based on the above-mentioned self-water ejector for fuel cells, comprising the following specific steps:

[0019] S1. Low-temperature fresh hydrogen enters the self-separating water ejector through the fresh hydrogen inlet. After passing through multiple fresh hydrogen chambers, the low-temperature fresh hydrogen enters the fresh hydrogen nozzle and leaves the self-separating water ejector through the rectifier tube, entering the hydrogen fuel cell stack to participate in the internal reaction of the stack.

[0020] S2. After the reactor reaction, the residual high-temperature saturated circulating hydrogen is discharged from the reactor outlet and enters the self-separating ejector through the circulating hydrogen inlet. The circulating hydrogen passes through multiple circulating hydrogen chambers in succession. During this process, it exchanges heat with the low-temperature new hydrogen in the new hydrogen chamber. The circulating hydrogen completes the separation of liquid water. The separated liquid water gathers at the bottom of the last circulating hydrogen chamber. After the liquid water reaches a certain amount, it is discharged from the self-separating ejector through the drain outlet.

[0021] S3. The flow rate of new hydrogen increases in the outlet section of the new hydrogen nozzle, forming a low-pressure zone. Under the action of the pressure difference, the circulating hydrogen in the last circulating hydrogen chamber is drawn into the rectifier tube and mixed with the new hydrogen.

[0022] S4. The mixed new hydrogen and recycled hydrogen leave the self-separating water ejector through the rectifier tube and enter the fuel cell stack to participate in the reaction, completing the recycling of hydrogen.

[0023] Compared with the prior art, the beneficial effects of the present invention are:

[0024] (1) By setting up a circulating hydrogen water separation and heat exchange section in the self-separating water ejector, while separating liquid water from circulating hydrogen, the temperature of the low-temperature new hydrogen is raised through heat exchange between circulating hydrogen and new hydrogen. This ensures that the circulating hydrogen and new hydrogen are at approximately the same temperature when they meet in the ejector section, avoiding the problem of secondary liquid water generation due to excessive temperature difference. This effectively reduces the amount of liquid water entering the hydrogen fuel cell stack and prevents low single-cell voltage at the gas distribution end of the fuel cell system caused by liquid water entering the stack. At the same time, this self-separating water ejector integrates the functions of ejector, heat exchanger and water separator in traditional hydrogen fuel cell systems, effectively reducing the structural volume of the hydrogen fuel cell system and improving the system's volumetric power density. It solves the problem of liquid water generation in the ejector when circulating hydrogen and low-temperature new hydrogen mix without introducing new external heat sources, thus reducing system costs.

[0025] (2) By arranging the new hydrogen chamber and the circulating hydrogen chamber at intervals from top to bottom, the heat exchange area between the new hydrogen and the circulating hydrogen is greatly increased. The high-temperature saturated circulating hydrogen coming out of the stack outlet is cooled down due to the absorption of heat by the low-temperature new hydrogen. The circulating hydrogen gas flow continuously impacts the heat exchange water distribution plate, causing the liquid water in the circulating hydrogen to separate from the hydrogen gas. At the same time, the low-temperature new hydrogen is heated up due to the absorption of heat from the circulating hydrogen. This makes the temperature of the new hydrogen close to that of the circulating hydrogen when it reaches the new hydrogen nozzle, thus avoiding the problem of liquid water being generated when the new hydrogen and the circulating hydrogen are mixed due to the large temperature difference, which exists in traditional ejectors.

[0026] Other features and advantages of the invention will be set forth in the following description, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention may be realized and obtained by means of the structures pointed out in the description and the drawings. Attached Figure Description

[0027] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0028] Figure 1 A three-dimensional structural schematic diagram of a self-water ejector for fuel cells according to an embodiment of the present invention is shown;

[0029] Figure 2 A schematic diagram of the internal structure of a self-water ejector for fuel cells according to an embodiment of the present invention is shown;

[0030] Figure 3 A three-dimensional structural schematic diagram of the ejector section according to an embodiment of the present invention is shown;

[0031] Figure 4 A cross-sectional view of the ejector section according to an embodiment of the present invention is shown.

[0032] In the diagram: 1. Water ejector; 2. Shell; 3. Fresh hydrogen inlet; 4. Circulating hydrogen inlet; 5. Ejector outlet; 6. Drain outlet; 7. Fresh hydrogen chamber; 8. Circulating hydrogen chamber; 9. Fresh hydrogen nozzle; 9-1. Fresh hydrogen nozzle connection section; 9-2. Fresh hydrogen nozzle outlet section; 10. Rectifier tube; 10-1. Rectifier tube contraction section; 10-2. Rectifier tube expansion section; 11. Heat exchange water distribution plate; 12. Fresh hydrogen guide tube; 13. Circulating hydrogen guide tube; 14. Water guide tube. Detailed Implementation

[0033] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0034] The term "embodiment" as used in this application means that a specific feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described in this application can be combined with other embodiments.

[0035] This invention provides a self-distributing water ejector for fuel cells, as shown in the attached figure. Figure 1-4 As shown, the self-water ejector 1 for fuel cells includes a housing 2, a new hydrogen inlet 3, a circulating hydrogen inlet 4, an ejector outlet 5, and a drain outlet 6. The new hydrogen inlet 3 and the circulating hydrogen inlet 4 are located on the top of the housing 2, the ejector outlet 5 is located on the side of the housing 2, and the drain outlet 6 is located at the bottom of the housing 2.

[0036] The interior of the housing 2 includes a circulating hydrogen water separation heat exchange section and an ejector section; the circulating hydrogen water separation heat exchange section includes a new hydrogen chamber 7 and a circulating hydrogen chamber 8, the number of new hydrogen chambers 7 and circulating hydrogen chambers 8 are equal, and the new hydrogen chambers 7 and circulating hydrogen chambers 8 are arranged at intervals from top to bottom; the ejector section includes a new hydrogen nozzle 9 and a rectifier tube 10, the ejector section is installed in the last circulating hydrogen chamber 8, the inlet of the new hydrogen nozzle is connected to the new hydrogen chamber 7, the outlet of the new hydrogen nozzle is inserted from the inlet of the rectifier tube, and the outlet of the new hydrogen nozzle and the inlet of the rectifier tube are not sealed together.

[0037] The self-diverting water ejector housing 2 has several heat exchange water distribution plates 11 horizontally arranged inside. The heat exchange water distribution plates 11 divide the inside of the housing 2 into several cavities. The cavities are arranged from top to bottom as a new hydrogen cavity 7 and a circulating hydrogen cavity 8.

[0038] The new hydrogen inlet 3 is connected to the first new hydrogen chamber 7, and the new hydrogen chambers 7 are connected to each other through a new hydrogen guide pipe 12.

[0039] The circulating hydrogen inlet 4 is connected to the first circulating hydrogen chamber 8 through the circulating hydrogen guide pipe 13, and the circulating hydrogen chambers 8 are connected to each other through the circulating hydrogen guide pipe 13.

[0040] The circulating hydrogen enters the circulating hydrogen chamber 8 through the circulating hydrogen inlet 4. The circulating hydrogen passes through multiple circulating hydrogen chambers 8 from top to bottom. During this process, the circulating hydrogen temperature decreases as its heat is transferred to the low-temperature new hydrogen. On the other hand, the circulating hydrogen gas flow continuously impacts the heat exchange water distribution plate 11, causing the liquid water in the circulating hydrogen to separate from the hydrogen gas.

[0041] By arranging the new hydrogen chamber and the circulating hydrogen chamber at intervals from top to bottom, the heat exchange area between the new hydrogen and the circulating hydrogen is greatly increased. The high-temperature saturated circulating hydrogen exiting the stack outlet is cooled down due to the absorption of heat by the low-temperature new hydrogen. Furthermore, the circulating hydrogen gas flow continuously impacts the heat exchange water distribution plate, causing the liquid water in the circulating hydrogen to separate from the hydrogen gas. At the same time, the low-temperature new hydrogen is heated up due to the absorption of heat from the circulating hydrogen. This ensures that the temperature of the new hydrogen is close to that of the circulating hydrogen when it reaches the new hydrogen nozzle, thus avoiding the problem of liquid water being generated when the new hydrogen and circulating hydrogen are mixed due to excessive temperature difference, which exists in traditional ejectors.

[0042] The new hydrogen nozzle 9 includes a new hydrogen nozzle connecting section 9-1 and a new hydrogen nozzle outlet section 9-2. The new hydrogen nozzle outlet section 9-2 has a conical tube structure. When new hydrogen passes through the new hydrogen nozzle 9, its flow rate increases because the new hydrogen nozzle outlet section 9-2 has a gradually narrowing conical tube structure.

[0043] The rectifier tube 10 includes a rectifier tube contraction section 10-1 and a rectifier tube expansion section 10-2, and the ejector outlet 5 is the outlet of the rectifier tube 10.

[0044] The new hydrogen nozzle outlet is inserted from the rectifier tube inlet, and the new hydrogen nozzle outlet and the rectifier tube inlet are not sealed together. Specifically, the rectifier tube contraction section 10-1 is coaxially sleeved outside the new hydrogen nozzle outlet section 9-2, and the outer side of the new hydrogen nozzle outlet section 9-2 and the inner side of the rectifier tube contraction section 10-1 form an annular gap. The circulating hydrogen after separating liquid water enters the rectifier tube 10 through the annular gap and mixes with the new hydrogen.

[0045] When the new hydrogen enters the new hydrogen nozzle, its flow velocity increases as it flows through the gradually contracting conical tube structure. According to Bernoulli's principle, as the velocity increases, the pressure decreases, forming a low-pressure zone. The pressure in the last circulating hydrogen chamber is greater than the pressure in the contracting section of the rectifier tube. Due to the pressure difference, the circulating hydrogen that has completed gas-water separation is drawn into the rectifier tube and mixed with the new hydrogen.

[0046] The last circulating hydrogen chamber 8 also has the function of storing liquid water separated from the circulating hydrogen. The outlet of the last circulating hydrogen guide pipe 13 is connected to the water guide pipe 14. The water guide pipe 14 introduces circulating hydrogen and liquid water into the last circulating hydrogen chamber 8. The outlet of the water guide pipe 14 is much lower than the ejector section, thereby preventing the separated liquid water from entering the ejector section and causing liquid water to enter the reactor.

[0047] The drain outlet 6 is equipped with a normally closed valve. When the amount of separated liquid water accumulates to a set standard, the normally closed valve will automatically open and the liquid water will be discharged.

[0048] By incorporating a circulating hydrogen water-separating heat exchange section within the self-separating water ejector, liquid water is separated from the circulating hydrogen. Simultaneously, the temperature of the cold new hydrogen rises through heat exchange between the circulating hydrogen and the fresh hydrogen, ensuring that the circulating and fresh hydrogen are at nearly identical temperatures when they converge at the ejector. This avoids the secondary generation of liquid water due to excessive temperature differences, effectively reducing the amount of liquid water entering the hydrogen fuel cell stack and preventing low voltage in individual cells at the fuel cell system's gas distribution end caused by liquid water entering the stack. Furthermore, this self-separating water ejector integrates the functions of the ejector, heat exchanger, and water separator found in traditional hydrogen fuel cell systems, effectively reducing the structural volume of the hydrogen fuel cell system and increasing its volumetric power density. It solves the problem of liquid water generation in the ejector when circulating hydrogen and cold new hydrogen mix without introducing a new external heat source, thus reducing system costs.

[0049] The present invention also provides a method for operating a self-distributing water ejector for a fuel cell, specifically including the following steps:

[0050] S1. Low-temperature fresh hydrogen enters the self-separating water ejector through the fresh hydrogen inlet. After passing through multiple fresh hydrogen chambers, the low-temperature fresh hydrogen enters the fresh hydrogen nozzle and leaves the self-separating water ejector through the rectifier tube, entering the hydrogen fuel cell stack to participate in the internal reaction of the stack.

[0051] S2. After the reactor reaction, the residual high-temperature saturated circulating hydrogen is discharged from the reactor outlet and enters the self-separating ejector through the circulating hydrogen inlet. The circulating hydrogen passes through multiple circulating hydrogen chambers in succession. During this process, it exchanges heat with the low-temperature new hydrogen in the new hydrogen chamber. The circulating hydrogen completes the separation of liquid water. The separated liquid water gathers at the bottom of the last circulating hydrogen chamber. After the liquid water reaches a certain amount, it is discharged from the self-separating ejector through the drain outlet.

[0052] S3. The flow rate of new hydrogen increases in the outlet section of the new hydrogen nozzle, forming a low-pressure zone. Under the action of the pressure difference, the circulating hydrogen in the last circulating hydrogen chamber is drawn into the rectifier tube and mixed with the new hydrogen.

[0053] S4. The mixed new hydrogen and recycled hydrogen leave the self-separating water ejector through the rectifier tube and enter the fuel cell stack to participate in the reaction, completing the recycling of hydrogen.

[0054] Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A self-draining water ejector for a fuel cell, characterized in that, The self-distributing water ejector (1) includes a shell (2), a new hydrogen inlet (3), a circulating hydrogen inlet (4), an ejector outlet (5), and a drain outlet (6). The new hydrogen inlet (3) and the circulating hydrogen inlet (4) are located at the top of the shell (2), the ejector outlet (5) is located on the side of the shell (2), and the drain outlet (6) is located at the bottom of the shell (2). The interior of the housing (2) includes a circulating hydrogen water separation heat exchange section and an ejector section; the circulating hydrogen water separation heat exchange section includes a new hydrogen chamber (7) and a circulating hydrogen chamber (8), the number of new hydrogen chambers (7) and circulating hydrogen chambers (8) are equal, and the new hydrogen chambers (7) and circulating hydrogen chambers (8) are arranged alternately from top to bottom; the ejector section includes a new hydrogen nozzle (9) and a rectifier tube (10), the ejector section is installed in the last circulating hydrogen chamber (8), the inlet of the new hydrogen nozzle is connected to the new hydrogen chamber (7), the outlet of the new hydrogen nozzle is inserted from the inlet of the rectifier tube, and the outlet of the new hydrogen nozzle is not sealed to the inlet of the rectifier tube; The self-dividing water ejector housing (2) is horizontally provided with several heat exchange water distribution plates (11), which divide the interior of the housing (2) into several cavities. The cavities are arranged from top to bottom as a new hydrogen cavity (7) and a circulating hydrogen cavity (8). The new hydrogen inlet (3) is connected to the first new hydrogen chamber (7), and the new hydrogen chambers (7) are connected to each other through a new hydrogen guide tube (12); The circulating hydrogen inlet (4) is connected to the first circulating hydrogen chamber (8) through a circulating hydrogen guide pipe (13), and the circulating hydrogen chambers (8) are connected to each other through a circulating hydrogen guide pipe (13). The circulating hydrogen enters the circulating hydrogen chamber (8) through the circulating hydrogen inlet (4). The circulating hydrogen passes through multiple circulating hydrogen chambers (8) from top to bottom. During this process, the circulating hydrogen temperature decreases as its heat is transferred to the low-temperature new hydrogen. On the other hand, the circulating hydrogen gas flow continuously impacts the heat exchange water separator (11), causing the liquid water in the circulating hydrogen to separate from the hydrogen gas.

2. The self-draining water ejector for fuel cells as described in claim 1, characterized in that, The new hydrogen nozzle (9) includes a new hydrogen nozzle connecting section (9-1) and a new hydrogen nozzle outlet section (9-2), and the new hydrogen nozzle outlet section (9-2) has a conical tube structure.

3. The self-draining water ejector for fuel cells as described in claim 2, characterized in that, The rectifier tube (10) includes a rectifier tube contraction section (10-1) and a rectifier tube expansion section (10-2), and the ejector outlet (5) is the outlet of the rectifier tube (10).

4. The self-draining water ejector for fuel cells as described in claim 3, characterized in that, The rectifier tube contraction section (10-1) is coaxially sleeved outside the new hydrogen nozzle outlet section (9-2), and the outer side of the new hydrogen nozzle outlet section (9-2) and the inner side of the rectifier tube contraction section (10-1) form an annular gap. The circulating hydrogen after separating liquid water enters the rectifier tube (10) through the annular gap and mixes with the new hydrogen.

5. The self-draining water ejector for fuel cells as described in claim 1, characterized in that, The outlet of the last circulating hydrogen guide tube (13) is connected to the water guide tube (14), which introduces circulating hydrogen and liquid water into the last circulating hydrogen chamber (8). The outlet of the water guide tube (14) is much lower than the ejector section.

6. The self-draining water ejector for a fuel cell as described in claim 1, characterized in that, A normally closed valve is installed at the drain outlet (6). When the amount of separated liquid water accumulates to a set standard, the normally closed valve will automatically open and the liquid water will be discharged.

7. A method for operating a self-draining water ejector for a fuel cell according to any one of claims 1-6, characterized in that, The specific steps include the following: S1. Low-temperature fresh hydrogen enters the self-separating water ejector through the fresh hydrogen inlet. After passing through multiple fresh hydrogen chambers, the low-temperature fresh hydrogen enters the fresh hydrogen nozzle and leaves the self-separating water ejector through the rectifier tube, entering the hydrogen fuel cell stack to participate in the internal reaction of the stack. S2. After the reactor reaction, the residual high-temperature saturated circulating hydrogen is discharged from the reactor outlet and enters the self-separating water ejector through the circulating hydrogen inlet. The circulating hydrogen passes through multiple circulating hydrogen chambers in succession. During this process, it exchanges heat with the low-temperature new hydrogen in the new hydrogen chamber. The circulating hydrogen completes the separation of liquid water. The separated liquid water gathers at the bottom of the last circulating hydrogen chamber. After the liquid water reaches a certain amount, it is discharged from the self-separating water ejector through the drain outlet. S3. The flow rate of new hydrogen increases in the outlet section of the new hydrogen nozzle, forming a low-pressure zone. Under the action of the pressure difference, the circulating hydrogen in the last circulating hydrogen chamber is drawn into the rectifier tube and mixed with the new hydrogen. S4. The mixed new hydrogen and recycled hydrogen leave the self-separating water ejector through the rectifier tube and enter the fuel cell stack to participate in the reaction, completing the recycling of hydrogen.

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