Fuel cell module

Abstract

To provide a fuel cell module capable of suppressing sticking of a cushion member of an injector.SOLUTION: A fuel cell module includes a plurality of injectors for adjusting a supply amount of a hydrogen gas to a fuel cell stack, and a control unit for controlling opening and closing of the plurality of injectors. The control unit performs normally open control for controlling opening and closing of the plurality of injectors so that the number of injectors in an open state is one or more at all times during a period from operation start to operation stop of the fuel cell stack. The control unit switches the injector in the open state in the normally open control.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a fuel cell module. [Background technology]

[0002] The fuel cell system described in Patent Document 1 includes a fuel cell stack, a plurality of injectors that adjust the amount of hydrogen gas supplied to the fuel cell stack, and a control unit that controls the opening and closing of the plurality of injectors.

[0003] The injector described in Patent Document 2 includes a fixed core, a movable core that opens and closes a nozzle hole by moving relative to the fixed core, and a rubber cushion member attached to the surface of the movable core that faces the fixed core. When the injector is in an open state, the cushion member is pressed against the fixed core by the movable core. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2022-028510 [Patent Document 2] Japanese Patent Publication No. 2022-146785 Summary of the Invention [Problem to be solved by the invention]

[0005] If the injector is left open for a long period of time, the cushion member may stick to the fixed core, which may cause delays in switching the injector from the open state to the closed state or may cause the cushion member to deteriorate. [Means for solving the problem]

[0006] A fuel cell module for solving the above problems is a fuel cell module comprising a plurality of injectors that adjust the amount of hydrogen gas supplied to a fuel cell stack, and a control unit that controls the opening and closing of the plurality of injectors, wherein the control unit performs always-open control that controls the opening and closing of the plurality of injectors so that the number of injectors in an open state is always at least one from the time the fuel cell stack starts operating until it stops operating, and in the always-open control, the injectors that are in an open state are alternated.

[0007] According to the above configuration, when the fuel cell stack is operated for a long time, it is possible to prevent a particular injector from being continuously in the open state for a long time, and therefore it is possible to prevent the cushion member of the injector from sticking.

[0008] In the fuel cell module, the control unit may alternate the injectors that are open based on time. According to the above configuration, control for switching the injector in the open state becomes easy.

[0009] In the fuel cell module, the control unit may switch the injector from a closed state to an open state before switching the injector from an open state to a closed state. With this configuration, compared to when an open injector is switched to a closed state and a closed injector is switched to an open state at the same time, it is possible to avoid a decrease in the pressure of the hydrogen gas supplied to the fuel cell stack when switching the open injector, thereby minimizing the impact on power generation by the fuel cell stack.

[0010] In the above fuel cell module, the multiple injectors may include a first injector, a second injector, and a third injector, and the control unit may repeatedly switch between a first opening / closing pattern in which the first injector and the third injector are in an open state and the second injector is in a closed state, a second opening / closing pattern in which the second injector and the third injector are in an open state and the first injector is in a closed state, and a third opening / closing pattern in which the first injector and the second injector are in an open state and the third injector is in a closed state, in this order.

[0011] According to the above configuration, the three injectors can be rotated so that the injectors that are in the open state are rotated two at a time. [Effects of the Invention]

[0012] According to the present invention, it is possible to prevent the cushion member of the injector from sticking. [Brief explanation of the drawings]

[0013] [Figure 1] FIG. 1 is a block diagram showing the configuration of a fuel cell module. [Figure 2] FIG. 2 is a cross-sectional view showing the injector. [Figure 3] Figure 3(a) is a timing chart showing the open / closed state of the first injector, Figure 3(b) is a timing chart showing the open / closed state of the second injector, and Figure 3(c) is a timing chart showing the open / closed state of the third injector. DETAILED DESCRIPTION OF THE INVENTION

[0014] An embodiment of a fuel cell module will be described below with reference to Figures 1 to 3. The fuel cell module is a versatile module that can be installed in industrial vehicles such as forklifts and towing tractors, as well as agricultural machinery, construction machinery, and emergency power supplies for factories.

[0015] <Fuel cell module> 1, a fuel cell module 10 includes a fuel cell stack 11, a hydrogen gas supply passage 12, a plurality of injectors 13, and a control unit 14. The fuel cell module 10 of this embodiment includes the plurality of injectors 13, which are a first injector 13a, a second injector 13b, and a third injector 13c.

[0016] The fuel cell stack 11 is made up of a plurality of fuel cell units stacked together. The fuel cell units are solid molecular fuel cells. The fuel cell stack 11 generates electricity through an electrochemical reaction between hydrogen gas as a fuel gas and oxygen in the air as an oxidant gas. The fuel cell stack 11 of this embodiment operates continuously for several days.

[0017] The hydrogen gas supply passage 12 is a passage for supplying hydrogen gas to the fuel cell stack 11. The hydrogen gas supply passage 12 connects the hydrogen tank 100 and the anode (not shown) of the fuel cell stack 11.

[0018] The multiple injectors 13 are provided along the hydrogen gas supply flow path 12. The hydrogen gas supply flow path 12 has an upstream flow path 21 that connects the hydrogen tank 100 and each of the multiple injectors 13, and a downstream flow path 22 that connects each of the multiple injectors 13 and the anode of the fuel cell stack 11.

[0019] As shown in FIG. 2, the injector 13 includes a housing 31, a valve 32, a cushion member 33, a seat , a core , a pipe , a spring 37, and a solenoid .

[0020] The housing 31 is cylindrical and houses the valve 32 and the seat 34. The valve 32 has a valve end wall 321 and a valve peripheral wall 322 that extends cylindrically from the valve end wall 321. The axial direction of the valve peripheral wall 322 is parallel to the axial direction of the housing 31. The valve 32 opens toward one side in the axial direction of the housing 31. An intersecting surface 322a that intersects with the axial direction of the valve peripheral wall 322 is provided on the inner circumferential surface of the valve peripheral wall 322. The valve peripheral wall 322 is provided with a valve through-hole 322b that penetrates the valve peripheral wall 322 in the radial direction. The valve through-hole 322b is located closer to the valve end wall 321 than the intersecting surface 322a in the axial direction of the valve peripheral wall 322.

[0021] The cushion member 33 is provided on the tip surface of the valve peripheral wall 322. The cushion member 33 is made of rubber. The seat 34 has a seat end wall 341 and a seat peripheral wall 342 extending cylindrically from the seat end wall 341. The axial direction of the seat peripheral wall 342 is parallel to the axial direction of the housing 31. The seat 34 is open toward the other side in the axial direction of the housing 31. A seat through-hole 341a is provided in the center of the seat end wall 341.

[0022] The core 35 is cylindrical. The core 35 is arranged next to the valve 32 in the axial direction of the valve 32. The axial direction of the core 35 is parallel to the axial direction of the valve 32. The inside of the core 35 is in communication with the inside of the valve 32.

[0023] The pipe 36 is fixed to the inner circumferential surface of the core 35. The inside of the pipe 36 is in communication with the inside of the core 35. The cushion member 33 is located between the tip end surface of the valve peripheral wall 322 and the axial end surface of the core 35.

[0024] The spring 37 is housed inside the valve 32 and the core 35. The spring 37 is disposed between the intersecting surface 322a of the valve 32 and the pipe 36 in the axial direction of the valve 32 and the core 35. The spring force of the spring 37 urges the valve 32 toward the seat 34.

[0025] The solenoid 38 has a bobbin 38a provided so as to surround the core 35, and a coil 38b wound around the bobbin 38a. Hydrogen gas flows from the hydrogen tank 100 into the inside of the core 35 through the upstream flow path 21, and then flows into the space between the inner surface of the housing 31 and the outer surface of the valve peripheral wall 322 via the inside of the pipe 36, the inside of the valve 32, and the valve through-hole 322b.

[0026] When the coil 38b of the solenoid 38 is not energized, the valve 32 is urged toward the seat 34 by the spring force of the spring 37 and abuts against the seat 34. As a result, the seat through-hole 341a of the seat 34 is blocked by the valve end wall 321 of the valve 32. Therefore, hydrogen gas that has flowed into the space between the inner circumferential surface of the housing 31 and the outer circumferential surface of the valve peripheral wall 322 does not flow out through the seat through-hole 341a. In other words, the injector 13 is in a closed state.

[0027] When the coil 38b of the solenoid 38 is energized, the valve 32 moves toward the core 35 against the spring force of the spring 37, thereby moving away from the seat 34. As a result, the seat through-hole 341a of the seat 34 is not blocked by the valve end wall 321 of the valve 32. Therefore, hydrogen gas that flows into the space between the inner circumferential surface of the housing 31 and the outer circumferential surface of the valve peripheral wall 322 passes between the valve end wall 321 and the seat end wall 341 and then flows out from the seat through-hole 341a. In other words, the injector 13 is in an open state. When the injector 13 is in an open state, the cushion member 33 is pressed against the core 35 by the valve 32.

[0028] The injector 13 adjusts the amount of hydrogen gas supplied to the fuel cell stack 11. When at least one of the multiple injectors 13 is in an open state, hydrogen gas is supplied to the fuel cell stack 11. The more injectors 13 that are in an open state, the smaller the pressure loss in the injectors 13, and therefore the higher the pressure of the hydrogen gas supplied to the fuel cell stack 11. In this embodiment, the target pressure of the hydrogen gas supplied to the fuel cell stack 11 is set to 0.1 MPaG.

[0029] As shown in FIG. 1 , the control unit 14 includes a processor 14a and a memory unit 14b. The processor 14a may be, for example, a central processing unit (CPU), a graphics processing unit (GPU), or a digital signal processor (DSP). The memory unit 14b includes a random access memory (RAM) and a read-only memory (ROM). The memory unit 14b stores program code or instructions configured to cause the processor 14a to execute processing. The memory unit 14b, i.e., a computer-readable medium, includes any available medium accessible by a general-purpose or special-purpose computer. The control unit 14 may be configured with hardware circuits such as an application-specific integrated circuit (ASIC) or a field-programmable gate array (FPGA). The control unit 14, which is a processing circuit, may include one or more processors operating according to a computer program, one or more hardware circuits such as ASICs or FPGAs, or a combination thereof. The control unit 14 controls the opening and closing of the multiple injectors 13.

[0030] <Injector opening / closing control by the control unit> As shown in FIGS. 3(a) to 3(c), the control unit 14 performs always-open control, which controls the opening and closing of the multiple injectors 13 so that the number of injectors 13 in an open state is always at least one, from the start of operation of the fuel cell stack 11 to the stop of operation. When operation starts, hydrogen gas is supplied to the fuel cell stack 11, and power generation begins. In this embodiment, if the number of injectors 13 in an open state is always at least two, hydrogen gas at a target pressure is supplied to the fuel cell stack 11. Therefore, the control unit 14 in this embodiment performs always-open control so that the number of injectors 13 in an open state is always at least two. In the always-open control, the control unit 14 alternates the injectors 13 that are open.

[0031] In the always-open control, the control unit 14 alternates the injectors 13 in an open state by switching the opening / closing pattern of the injectors 13. A plurality of opening / closing patterns for the injectors 13 are set. The combination of the injectors 13 in an open state and the injectors 13 in a closed state in each opening / closing pattern is different for each opening / closing pattern. In this embodiment, a first opening / closing pattern, a second opening / closing pattern, and a third opening / closing pattern are set as the opening / closing patterns for the injectors 13.

[0032] The first opening / closing pattern is an opening / closing pattern in which the first injector 13a and the third injector 13c are open and the second injector 13b is closed. The second opening / closing pattern is an opening / closing pattern in which the second injector 13b and the third injector 13c are open and the first injector 13a is closed. The third opening / closing pattern is an opening / closing pattern in which the first injector 13a and the second injector 13b are open and the third injector 13c is closed. The control unit 14 repeatedly switches between the first opening / closing pattern, the second opening / closing pattern, and the third opening / closing pattern in this order.

[0033] When the opening / closing pattern is switched from the first opening / closing pattern to the second opening / closing pattern, the injector 13 in the open state is changed from the first injector 13a to the second injector 13b. When the opening / closing pattern is switched from the first opening / closing pattern to the second opening / closing pattern, the injector 13 in the closed state is changed from the second injector 13b to the first injector 13a. Note that even when the opening / closing pattern is switched from the first opening / closing pattern to the second opening / closing pattern, the third injector 13c remains open.

[0034] When the opening / closing pattern is switched from the second opening / closing pattern to the third opening / closing pattern, the injector 13 in the open state is changed from the third injector 13c to the first injector 13a. When the opening / closing pattern is switched from the second opening / closing pattern to the third opening / closing pattern, the injector 13 in the closed state is changed from the first injector 13a to the third injector 13c. Note that even when the opening / closing pattern is switched from the second opening / closing pattern to the third opening / closing pattern, the second injector 13b remains open.

[0035] When the opening / closing pattern is switched from the third opening / closing pattern to the first opening / closing pattern, the injector 13 in the open state is changed from the second injector 13b to the third injector 13c. When the opening / closing pattern is switched from the third opening / closing pattern to the first opening / closing pattern, the injector 13 in the closed state is changed from the third injector 13c to the second injector 13b. Note that even when the opening / closing pattern is switched from the third opening / closing pattern to the first opening / closing pattern, the first injector 13a remains open.

[0036] The control unit 14 of this embodiment switches the injectors 13 that are open based on time. Specifically, the control unit 14 switches the opening / closing pattern every time a predetermined time T has elapsed. In this embodiment, the predetermined time T is set to, for example, one hour. Therefore, the control unit 14 of this embodiment switches the opening / closing pattern every time one hour has elapsed.

[0037] The control unit 14 of this embodiment switches the injector 13 from a closed state to an open state before switching the injector 13 from an open state to a closed state. For example, it is assumed that the control unit 14 sets the opening / closing pattern to the first opening / closing pattern at time t0. The control unit 14 switches the opening / closing pattern from the first opening / closing pattern to the second opening / closing pattern at time t1, which is a predetermined first time Ta before time t0. At this time, the control unit 14 of this embodiment switches the second injector 13b from the closed state to the open state at time t1a, which is a predetermined first time Ta before time t1. Furthermore, the control unit 14 of this embodiment switches the first injector 13a from the open state to the closed state at time t1b, which is a predetermined second time Tb after time t1. As a result, the second injector 13b, which is in the closed state, is switched to the open state before the first injector 13a, which is in the open state, is switched to the closed state. From time t1a to time t1b, the first to third injectors 13a to 13c are all in the open state.

[0038] The control unit 14 switches the opening / closing pattern from the second opening / closing pattern to the third opening / closing pattern at time t2, a predetermined time T after time t1. At this time, the control unit 14 of this embodiment switches the first injector 13a from the closed state to the open state at time t2a, a predetermined first time Ta before time t2. The control unit 14 of this embodiment also switches the third injector 13c from the open state to the closed state at time t2b, a predetermined second time Tb after time t2. As a result, the first injector 13a, which is in the closed state, is switched to the open state before the third injector 13c, which is in the open state, is switched to the closed state. From time t2a to time t2b, the first to third injectors 13a to 13c are all in the open state.

[0039] The control unit 14 switches the opening / closing pattern from the third opening / closing pattern to the first opening / closing pattern at time t3, a predetermined time T after time t2. At this time, the control unit 14 of this embodiment switches the third injector 13c from the closed state to the open state at time t3a, a predetermined first time Ta before time t3. The control unit 14 of this embodiment also switches the second injector 13b from the open state to the closed state at time t3b, a predetermined second time Tb after time t3. As a result, the third injector 13c, which is in the closed state, is switched to the open state before the second injector 13b, which is in the open state, is switched to the closed state. From time t3a to time t3b, all of the first to third injectors 13a to 13c are in the open state.

[0040] [Operation of this embodiment] The operation of this embodiment will be described. The control unit 14 performs always-open control, which controls the opening and closing of the multiple injectors 13 so that the number of injectors 13 in the open state is always at least one from the start of operation of the fuel cell stack 11 to the stop of operation. In the always-open control, the control unit 14 alternates the injectors 13 in the open state. This configuration makes it possible to prevent a specific injector 13 from being continuously in the open state for a long period of time when the fuel cell stack 11 is operated for a long period of time. Therefore, the cushion member 33 of the injector 13 is less likely to stick to the core 35.

[0041] As a result, when the injector 13 is switched from the open state to the closed state, the cushion member 33 can smoothly separate from the core 35, which reduces delays in switching the injector 13 from the open state to the closed state. This prevents the pressure of the hydrogen gas supplied to the fuel cell stack 11 from becoming higher than expected, thereby preventing a decrease in performance of the fuel cell stack 11. Furthermore, deterioration of the cushion member 33 due to the cushion member 33 sticking to the core 35 can be prevented.

[0042] [Effects of this embodiment] The effects of this embodiment will be described. (1) The control unit 14 performs always-open control, which controls the opening and closing of the multiple injectors 13 so that the number of injectors 13 in the open state is always at least one from the start of operation of the fuel cell stack 11 to the stop of operation. In the always-open control, the control unit 14 alternates the injectors 13 in the open state. This configuration makes it possible to prevent a specific injector 13 from being continuously in the open state for a long period of time when the fuel cell stack 11 is operated for a long period of time. Therefore, it is possible to prevent the cushion member 33 of the injector 13 from sticking.

[0043] (2) The control unit 14 alternates the open injectors 13 based on time. This configuration facilitates the control of alternately switching the open injectors 13. (3) The control unit 14 switches the closed injector 13 to the open state before switching the open injector 13 to the closed state. This configuration makes it possible to avoid a decrease in the pressure of the hydrogen gas supplied to the fuel cell stack 11 when switching the open injector 13, compared to when the open injector 13 is switched to the closed state at the same time that the closed injector 13 is switched to the open state. Therefore, the impact on power generation by the fuel cell stack 11 can be reduced.

[0044] (4) The fuel cell module 10 includes a first injector 13a, a second injector 13b, and a third injector 13c as the multiple injectors 13. The control unit 14 repeatedly switches between a first opening / closing pattern, a second opening / closing pattern, and a third opening / closing pattern in this order. The first opening / closing pattern is an opening / closing pattern in which the first injector 13a and the third injector 13c are open and the second injector 13b is closed. The second opening / closing pattern is an opening / closing pattern in which the second injector 13b and the third injector 13c are open and the first injector 13a is closed. The third opening / closing pattern is an opening / closing pattern in which the first injector 13a and the second injector 13b are open and the third injector 13c is closed. With this configuration, the three injectors 13 can rotate two injectors 13 in an open state.

[0045] [Example of change] The above embodiment can be modified as follows: The above embodiment and the following modifications can be combined with each other within the scope of technical compatibility.

[0046] The number of injectors 13 included in the fuel cell module 10 is not limited to three. The number of injectors 13 included in the fuel cell module 10 may be changed as appropriate as long as it is two or more.

[0047] In the above embodiment, the control unit 14 performs the always-open control so that the number of injectors 13 in the open state is always two or more, but this is not limited to this. As long as hydrogen gas at the target pressure can be supplied to the fuel cell stack 11, the control unit 14 may perform the always-open control so that the number of injectors 13 in the open state is always one or more.

[0048] In the above embodiment, the control unit 14 switches the open injectors 13 based on time, but this is not limited to this. The control unit 14 may switch the open injectors 13 based on, for example, the detection result of the pressure in the downstream flow path 22 or a prediction of the amount of hydrogen gas consumed by the fuel cell stack 11.

[0049] In the normally open control, the control unit 14 may change the number of open injectors 13 as long as the number of open injectors 13 is always one or more. For example, when it is predicted that the amount of hydrogen gas consumed by the fuel cell stack 11 will decrease, the control unit 14 may, in the normally open control, reduce the number of open injectors 13 from two to one at the same time as rotating the open injectors 13. Specifically, when the amount of hydrogen gas consumed by the fuel cell stack 11 decreases, the control unit 14 switches the two open injectors 13 to a closed state and switches the one closed injector 13 to an open state.

[0050] The control unit 14 may switch the injector 13 from the closed state to the open state at the same time as switching the injector 13 from the open state to the closed state. In the above embodiment, the control unit 14 switches the second injector 13b from the closed state to the open state at time t1a, which is before time t1, and switches the first injector 13a from the open state to the closed state at time t1b, which is after time t1. However, this is not limited to this.

[0051] As an example, the control unit 14 may switch the second injector 13b from the closed state to the open state at time t1a, and may switch the first injector 13a from the open state to the closed state at time t1. In this example, the injector 13 in the closed state is switched to the open state before the injector 13 in the open state is switched to the closed state, thereby achieving the same effect as effect (3) of the above embodiment.

[0052] As another example, the control unit 14 may switch the second injector 13b from the closed state to the open state at time t1, and may switch the first injector 13a from the open state to the closed state at time t1b. In this example, the injector 13 in the closed state is switched to the open state before the injector 13 in the open state is switched to the closed state, thereby achieving the same effect as effect (3) of the above embodiment.

[0053] [Note] The technical ideas that can be understood from the above-described embodiment and modifications will be described below. <Appendix 1> A fuel cell module comprising a plurality of injectors that adjust the amount of hydrogen gas supplied to a fuel cell stack, and a control unit that controls the opening and closing of the plurality of injectors, wherein the control unit performs a constantly open control that controls the opening and closing of the plurality of injectors so that the number of injectors in an open state is always at least one from the time the fuel cell stack starts operating until it stops operating, and during the constantly open control, the fuel cell module alternates the injectors that are in an open state.

[0054] <Appendix 2> 2. The fuel cell module of claim 1, wherein the controller alternates the injectors in an open state based on time.

[0055] <Appendix 3> 3. The fuel cell module according to claim 1, wherein the control unit switches the injector from a closed state to an open state before switching the injector from an open state to a closed state.

[0056] <Appendix 4> 4. A fuel cell module according to any one of appendices 1 to 3, comprising a first injector, a second injector, and a third injector as the plurality of injectors, wherein the control unit repeatedly switches between a first opening / closing pattern in which the first injector and the third injector are in an open state and the second injector is in a closed state, a second opening / closing pattern in which the second injector and the third injector are in an open state and the first injector is in a closed state, and a third opening / closing pattern in which the first injector and the second injector are in an open state and the third injector is in a closed state, in this order. [Explanation of symbols]

[0057] 10... fuel cell module, 11... fuel cell stack, 13... injector, 13a... first injector, 13b... second injector, 13c... third injector, 14... control unit.

Claims

1. a plurality of injectors for adjusting the amount of hydrogen gas supplied to the fuel cell stack; a control unit that controls opening and closing of the plurality of injectors; A fuel cell module comprising: the control unit performs a constantly open control to control the opening and closing of the plurality of injectors so that the number of the injectors in an open state is always one or more from the start of operation to the stop of operation of the fuel cell stack, A fuel cell module that alternates the injectors that are in an open state during the normally open control.

2. 2. The fuel cell module according to claim 1, wherein the control unit alternates the injectors in an open state based on time.

3. 2. The fuel cell module according to claim 1, wherein the control unit switches the injector from a closed state to an open state before switching the injector from an open state to a closed state.

4. The plurality of injectors include a first injector, a second injector, and a third injector, 2. The fuel cell module of claim 1, wherein the control unit repeatedly switches between a first opening / closing pattern in which the first injector and the third injector are in an open state and the second injector is in a closed state, a second opening / closing pattern in which the second injector and the third injector are in an open state and the first injector is in a closed state, and a third opening / closing pattern in which the first injector and the second injector are in an open state and the third injector is in a closed state, in this order.

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