Fuel cell hydrogen cycle components

Abstract

The present invention discloses a fuel cell hydrogen circulation component, including a shell, a one-way valve, a position sensor, a circulation pump and a controller. A first cavity, a second cavity, a main channel and a branch channel are provided inside the shell, a first interface and a second interface are provided on the side wall of the first cavity, and a third interface is provided on the side wall of the branch channel. The upper end of the one-way valve is hingedly mounted on the side wall of the second cavity, so that the one-way valve completely blocks the first connecting hole when it droops naturally. The position sensor is installed in the second cavity for sensing the angle of the one-way valve. The position sensor is electrically connected to the controller, and the controller is electrically connected to the circulation pump. Compared with the prior art, the fuel cell hydrogen circulation component of the present invention can not only realize the basic function of the one-way valve to prevent gas backflow, but also be used to monitor the hydrogen flow through the one-way valve. It is not only convenient to calculate the hydrogen utilization rate, but also convenient to realize the closed-loop control of the circulation pump speed according to the hydrogen flow.

Description

Technical Field

[0001] The invention relates to the technical field of proton exchange membrane fuel cells, in particular to a fuel cell hydrogen circulation component. Background Art

[0002] In a proton exchange membrane fuel cell (PEMFC), hydrogen reacts with oxygen to produce water, and the chemical energy in the hydrogen is directly converted into electrical energy. The ratio of the electrical energy actually emitted by the PEMFC to the chemical energy carried by the hydrogen flow entering the fuel cell system is defined as the efficiency of the PEMFC. In order to improve the utilization rate of hydrogen, it is often necessary to circulate the incompletely reacted hydrogen from the outlet of the stack to the inlet of the stack, that is, to achieve the recycling of hydrogen. The device that provides this circulation power is called a hydrogen circulation system.

[0003] At present, the fuel cell hydrogen circulation system mainly adopts the technical solution of connecting the circulation pump and the ejector in parallel. This technical solution is difficult to achieve comprehensive optimization of efficiency and hydrogen utilization rate at the same time for the following reasons:

[0004] (1) The ejector port is connected to the circulation pump inlet, and the ejector mixing port is connected to the circulation pump outlet. If the pressure at both ends of the circulation pump does not match the ejector, the hydrogen flow may enter the ejector port from the high-pressure port, causing the ejector to fail to work properly, and even causing the circulation pump inlet pressure to be too high, resulting in a decrease in circulation flow.

[0005] (2) Under medium power conditions, the circulation pump and the ejector need to work together, and the speed of the circulation pump needs to be controlled in real time according to the ejector flow rate. At present, there is no method to measure the ejector flow rate, which is not conducive to the continuous use of the circulation pump and the ejector. Summary of the invention

[0006] The purpose of the present invention is to provide a fuel cell hydrogen circulation component, which can not only realize the basic function of the one-way valve to prevent gas backflow, but also be used to monitor the hydrogen flow through the one-way valve to facilitate the calculation of the circulating hydrogen utilization rate.

[0007] To achieve the above object, the present invention provides the following solutions:

[0008] The invention discloses a fuel cell hydrogen circulation assembly, comprising a housing, a one-way valve, a position sensor, a circulation pump and a controller;

[0009] The shell is provided with a first cavity, a second cavity, a main channel and a branch channel; the first cavity is connected to the second cavity through a first connecting hole, the second cavity is connected to the main channel through a second connecting hole, and the main channel is connected to the branch channel;

[0010] A first interface and a second interface are provided on the side wall of the first cavity, and a third interface is provided on the side wall of the branch channel; the first interface is used to connect to the hydrogen outlet of the fuel cell stack, the second interface is connected to the inlet of the circulation pump, the third interface is connected to the outlet of the circulation pump, the inlet of the main channel is used to connect to the outlet of the hydrogen tank, and the outlet of the main channel is used to connect to the hydrogen inlet of the fuel cell stack;

[0011] The upper end of the one-way valve is hingedly mounted on the side wall of the second cavity, so that the one-way valve completely covers the first connecting hole when it droops naturally; the position sensor is installed in the second cavity to sense the angle of the one-way valve;

[0012] The position sensor is electrically connected to the controller, and the controller is electrically connected to the circulation pump; the controller is used to start the circulation pump when the one-way valve angle is vertical; to shut down the circulation pump when the one-way valve angle is maximum; and to calculate the actual flow rate passing through the one-way valve and the rotational speed of the circulation pump according to the angle of the one-way valve when the one-way valve angle is between vertical and the maximum angle.

[0013] Preferably, the one-way valve includes a rotating shaft, a valve plate and a boss; the rotating shaft is fixed to the upper end of the valve plate, the rotating shaft is horizontally arranged and hinged on the side wall of the second cavity; the boss is fixed to the side of the valve plate away from the first connecting hole.

[0014] Preferably, the shell includes an end cover, a cover plate and a nozzle; the cover plate is a side wall of the second cavity, one end of the rotating shaft is hinged on the cover plate, the other end of the rotating shaft is hinged on the end cover, and the cover plate is detachably fixed to the end cover; the nozzle is detachably fixed at the entrance of the main channel and is used to connect to the outlet of the hydrogen tank through a pipeline.

[0015] Preferably, the fuel cell hydrogen circulation assembly further comprises screws, and the cover plate is fixed to the end cover by the screws.

[0016] Preferably, the one-way valve comprises a plurality of ones that are replaceable with each other, and among the plurality of one-way valves, the heights of the bosses on the valve plate are different.

[0017] Preferably, the cross-sectional area of ​​the main channel gradually increases from the inlet to the outlet; the portion of the main channel close to the outlet is connected to the branch channel, and the portion of the main channel close to the inlet is connected to the second cavity through the second connecting hole.

[0018] Compared with the prior art, the present invention has achieved the following technical effects:

[0019] In the fuel cell hydrogen circulation component, the one-way valve has a simple structure, is easy to install, has a high degree of integration, occupies a small space, and is conducive to integrated design. By utilizing the structural characteristics of the one-way valve itself and combining it with a position sensor, the circulation pump speed can be calculated through the opening angle of the one-way valve, thereby ensuring the optimal output speed, avoiding parasitic power in the circulation pump, and ensuring continuity of use. In addition, by monitoring the hydrogen flow rate of the first branch, it is possible to know how much unreacted hydrogen is recycled, thereby calculating the hydrogen utilization rate and more accurately obtaining the actual power generation efficiency of the fuel cell system. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0021] Figure 1 It is a structural schematic diagram of a one-way valve;

[0022] Figure 2 is a schematic diagram of the structure of the cover plate;

[0023] Figure 3 This is a partial structural schematic diagram of the hydrogen circulation assembly of the fuel cell in this embodiment;

[0024] Figure 4 It is a partial structural exploded view of the hydrogen circulation assembly of the fuel cell in this embodiment;

[0025] Figure 5 It is a partial structural front view of the hydrogen circulation assembly of the fuel cell of this embodiment;

[0026] Figure 6 for Figure 5 The cross-sectional view along the DD direction;

[0027] Figure 7 It is a schematic diagram of a one-way valve when it is closed;

[0028] Figure 8 It is a schematic diagram when the opening angle of the one-way valve is θ;

[0029] Fig. 9 A schematic diagram of the connection relationship of the hydrogen circulation components of the fuel cell of this embodiment;

[0030] Fig.10 This is a simplified diagram of the control principle of the controller.

[0031] In the figure: 1- one-way valve; 2- cover plate; 3- end cover; 4- nozzle; 5- main channel; 6- first cavity; 7- first connecting hole; 8- first interface; 9- second interface; 10- third interface; 11- screw; 12- first axial hole; 13- second axial hole; 14- second cavity; 15- second connecting hole; 16- branch channel; 17- circulation pump; 18- fuel cell stack; 19- hydrogen tank; 20- pressure reducing valve; 101- rotating shaft; 102- valve plate; 103- boss. DETAILED DESCRIPTION

[0032] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0033] Reference Figures 1 to 10 This embodiment provides a fuel cell hydrogen circulation assembly, including a housing, a one-way valve 1, a position sensor, a circulation pump 17 and a controller.

[0034] The shell is provided with a first cavity 6, a second cavity 14, a main channel 5 and a branch channel 16. The first cavity 6 is connected to the second cavity 14 through the first connecting hole 7, the second cavity 14 is connected to the main channel 5 through the second connecting hole 15, and the main channel 5 is connected to the branch channel 16.

[0035] A first interface 8 and a second interface 9 are provided on the side wall of the first cavity 6, and a third interface 10 is provided on the side wall of the branch channel 16. The first interface 8 is used to connect to the hydrogen outlet of the battery stack 18, the second interface 9 is connected to the inlet of the circulation pump 17, the third interface 10 is connected to the outlet of the circulation pump 17, the inlet of the main channel 5 is used to connect to the outlet of the hydrogen tank 19, and the outlet of the main channel 5 is used to connect to the hydrogen inlet of the battery stack 18.

[0036] The upper end of the one-way valve 1 is hingedly mounted on the side wall of the second cavity 14, so that the one-way valve 1 completely blocks the first connecting hole 7 when it droops naturally. A position sensor is installed in the second cavity 14 to sense the angle of the one-way valve 1.

[0037] The position sensor is electrically connected to the controller, and the controller is electrically connected to the circulation pump 17. The controller is used to start the circulation pump 17 when the angle of the one-way valve 1 is vertical. When the angle of the one-way valve 1 is maximum, the circulation pump 17 is shut down. When the angle of the one-way valve 1 is between vertical and maximum, the actual flow through the one-way valve 1 and the rotation speed of the circulation pump 17 are calculated according to the angle of the one-way valve 1.

[0038] The working principle of the fuel cell hydrogen circulation assembly of this embodiment is as follows:

[0039] The hydrogen stored in the hydrogen tank 19 enters the main channel 5 from the entrance of the main channel 5 and flows out of the main channel 5 from the exit of the main channel 5. The circulating hydrogen discharged from the battery stack 18 is divided into two branches. The hydrogen in the first branch passes through the first interface 8, the first cavity 6, the first connecting hole 7, the one-way valve 1, the second cavity 14, and the second connecting hole 15 in turn into the main channel 5, and the hydrogen in the second branch passes through the first interface 8, the first cavity 6, the second interface 9, the circulation pump 17, the third interface 10, and the branch channel 16 in turn into the main channel 5. The one-way valve 1 can only be opened in one direction, so the hydrogen can only flow to the main channel 5 through the one-way valve 1, and will not flow in the opposite direction. The hydrogen in the main channel 5 plays an ejection role on the hydrogen in the first branch. When the hydrogen in the first branch cannot open the one-way valve 1 to the maximum angle, the controller starts the circulation pump 17, and the two branches jointly transport the circulating hydrogen to the main channel 5. Finally, the circulating hydrogen and the hydrogen provided by the hydrogen tank 19 flow out from the outlet of the main channel 5 and flow into the hydrogen inlet of the fuel cell stack 18 together.

[0040] When the angle of the one-way valve 1 can be maintained between the vertical and the maximum angle, it is approximately in a force balance state. According to the force balance formula, combined with the size, weight distribution and angle of the one-way valve 1, the horizontal thrust provided by the hydrogen in the first branch to the one-way valve 1 can be calculated, and then the flow rate of hydrogen in the first branch can be obtained.

[0041] If the total flow of circulating hydrogen is determined, the flow of hydrogen in the first branch is subtracted from the total flow of circulating hydrogen to obtain the flow of hydrogen in the second branch. The rotation speed of the circulating pump 17 can be obtained by combining the performance parameters of the circulating pump 17.

[0042] In the fuel cell hydrogen circulation assembly, the one-way valve 1 has a simple structure, is easy to install, has a high degree of integration, occupies a small space, and is conducive to integrated design. By utilizing the structural characteristics of the one-way valve 1 itself and combining it with a position sensor, the rotation speed of the circulation pump 17 can be calculated through the opening angle of the one-way valve 1, thereby ensuring the optimal output speed, avoiding the parasitic power of the circulation pump 17, and ensuring the continuity of use. In addition, by monitoring the hydrogen flow rate of the first branch, it is possible to know how much unreacted hydrogen is recycled, which can not only know the hydrogen utilization rate, but also better control the amount of hydrogen provided by the hydrogen tank 19.

[0043] As a possible example, in this embodiment, the one-way valve 1 includes a rotating shaft 101, a valve plate 102 and a boss 103. The rotating shaft 101 is fixed to the upper end of the valve plate 102, and the rotating shaft 101 is horizontally arranged and hinged on the side wall of the second cavity 14. The boss 103 is fixed to the side of the valve plate 102 away from the first connecting hole 7. The friction force when the rotating shaft 101 rotates should be as small as possible. The two ends of the rotating shaft 101 can respectively cooperate with the side wall clearance of the second cavity 14 through the first shaft hole 12 and the second shaft hole 13, and can also cooperate with the bearing fixed on the side wall of the second cavity 14. The boss 103 is used as a counterweight to increase the difficulty of rotating the one-way valve 1.

[0044] As a possible example, in this embodiment, the shell includes an end cover 3, a cover plate 2 and a nozzle 4. The cover plate 2 is a side wall of the second cavity 14, one end of the rotating shaft 101 is hinged on the cover plate 2, the other end of the rotating shaft 101 is hinged on the end cover 3, and the cover plate 2 is detachably fixed on the end cover 3. The nozzle 4 is detachably fixed at the entrance of the main channel 5, and is used to connect the outlet of the hydrogen tank 19 through a pipeline. The nozzle 4 is threadedly connected to the main channel 5 to meet the needs of rapid replacement.

[0045] As a possible example, in this embodiment, the fuel cell hydrogen circulation assembly further includes screws 11, and the cover plate 2 is fixed to the end cover 3 by the screws 11. According to different actual needs, those skilled in the art may also choose other methods to fix the cover plate 2.

[0046] As a possible example, in this embodiment, the one-way valve 1 includes multiple and interchangeable one-way valves, and the heights of the boss 103 on the valve plate 102 are different in the multiple one-way valves 1. In actual use, the appropriate height of the boss 103 can be selected according to the flow rate of the circulating hydrogen.

[0047] As a possible example, in this embodiment, the cross-sectional area of ​​the main channel 5 gradually increases from the inlet to the outlet. The part of the main channel 5 near the outlet is connected to the branch channel 16, and the part of the main channel 5 near the inlet is connected to the second cavity 14 through the second connecting hole 15, so that the airflows of the two branches merging into the main channel 5 are staggered. According to different actual needs, those skilled in the art can also choose other parallel positions.

[0048] The present invention uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only used to help understand the method and core ideas of the present invention. At the same time, for those skilled in the art, according to the ideas of the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. A fuel cell hydrogen circulation assembly, characterized in that: It includes a housing, a one-way valve, a position sensor, a circulation pump and a controller; The shell is provided with a first cavity, a second cavity, a main channel and a branch channel; the first cavity is connected to the second cavity through a first connecting hole, the second cavity is connected to the main channel through a second connecting hole, and the main channel is connected to the branch channel; A first interface and a second interface are provided on the side wall of the first cavity, and a third interface is provided on the side wall of the branch channel; the first interface is used to connect to the hydrogen outlet of the fuel cell stack, the second interface is connected to the inlet of the circulation pump, the third interface is connected to the outlet of the circulation pump, the inlet of the main channel is used to connect to the outlet of the hydrogen tank, and the outlet of the main channel is used to connect to the hydrogen inlet of the fuel cell stack; The upper end of the one-way valve is hingedly mounted on the side wall of the second cavity, so that the one-way valve completely covers the first connecting hole when it droops naturally; the position sensor is installed in the second cavity to sense the angle of the one-way valve; The position sensor is electrically connected to the controller, and the controller is electrically connected to the circulation pump; the controller is used to start the circulation pump when the one-way valve angle is vertical; shut down the circulation pump when the one-way valve angle is maximum; when the one-way valve angle is between vertical and maximum angle, calculate the actual flow through the one-way valve and the rotation speed of the circulation pump according to the one-way valve angle; The one-way valve includes a rotating shaft, a valve plate and a boss; the rotating shaft is fixed to the upper end of the valve plate, the rotating shaft is horizontally arranged and hinged on the side wall of the second cavity; the boss is fixed to the side of the valve plate away from the first connecting hole.

2. The fuel cell hydrogen circulation assembly according to claim 1, characterized in that: The shell includes an end cover, a cover plate and a nozzle; the cover plate is a side wall of the second cavity, one end of the rotating shaft is hinged on the cover plate, the other end of the rotating shaft is hinged on the end cover, and the cover plate is detachably fixed on the end cover; the nozzle is detachably fixed at the entrance of the main channel and is used to connect the outlet of the hydrogen tank through a pipeline.

3. The fuel cell hydrogen circulation assembly according to claim 2, characterized in that: It also includes screws, and the cover plate is fixed to the end cover by the screws.

4. The fuel cell hydrogen circulation assembly according to claim 1, characterized in that: The one-way valve includes a plurality of ones that can be replaced with each other, and among the plurality of one-way valves, the heights of the bosses on the valve plate are different.

5. The fuel cell hydrogen circulation assembly according to claim 1, characterized in that: The cross-sectional area of ​​the main channel gradually increases from the inlet to the outlet; the portion of the main channel close to the outlet is connected to the branch channel, and the portion of the main channel close to the inlet is connected to the second cavity through the second connecting hole.

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