Fuel cell control system and method

Abstract

The application discloses a fuel cell control system, comprising: hydrogen inlet group valve, hydrogen outlet group valve, anode water distribution assembly and anode water outlet valve; the hydrogen inlet group valve is connected with the hydrogen inlet of the fuel cell, the hydrogen outlet of the fuel cell is connected with the inlet of the anode water distribution assembly, the first outlet of the anode water distribution assembly is connected with the anode water outlet valve, the second outlet of the anode water distribution assembly is connected with the hydrogen outlet group valve, and the third outlet of the anode water distribution assembly is connected with the hydrogen inlet of the fuel cell. The application realizes fine control of exhaust at low power stage by selecting different diameter hydrogen outlet valves for exhaust replacement at different power stages. Meanwhile, the hydrogen outlet valve usually has no working state feedback, and the change value of the control parameter of the system air inlet pressure or air inlet valve is used for judgment, so that the effective detection of the function characteristics of the hydrogen outlet valve is realized, the hydrogen outlet valves are used as mutual spare parts by layer-by-layer calling, the shutdown failure is reduced, and the reliability of the whole system is improved.

Description

Technical Field

[0001] This invention belongs to the field of fuel cell technology, and particularly relates to a fuel cell control system and method. Background Technology

[0002] In recent years, the application of fuel cells in the transportation sector has been vigorously promoted. Application scenarios have gradually expanded from buses to heavy-duty trucks, and applications are beginning to be explored in heavy construction machinery. As a result, the market demand for fuel cell systems' power has been increasing year by year. Currently, most system manufacturers can design the minimum sustainable power point to be within 10% Pe. To adapt to multiple scenarios, the market's requirements for the power application range of fuel cell systems are also gradually expanding, with current technical requirements even targeting 5% Pe and below. Therefore, how to balance the corresponding performance attributes of high and low power in fuel cell design has become a major challenge in the current development of fuel cell system technology.

[0003] The economic attributes of fuel cell systems are a key focus of the market, as their quality directly impacts the operating costs of the product in its application environment. Analysis reveals that a crucial factor influencing overall system efficiency is hydrogen utilization (the ratio of hydrogen flow rate to the actual hydrogen supply). During actual fuel cell operation, some hydrogen is discharged from the system during anode replacement and drainage, failing to participate in the reaction. The amount of anode venting depends primarily on the vent valve diameter and the design of the opening cycle strategy. As system rated power demands increase, to achieve effective drainage, the vent valve diameter is typically larger than that of lower-power systems. Combined with the control precision of high-frequency switching valves, excessive hydrogen emission frequently occurs in high-power systems operating at lower power levels, significantly affecting system efficiency at lower power levels. Summary of the Invention

[0004] To address the problems existing in the prior art, this invention provides a fuel cell control system and method that can reduce hydrogen over-emission and improve overall efficiency.

[0005] The technical problem to be solved by the present invention is achieved through the following technical solution:

[0006] In a first aspect, a fuel cell control system is provided, comprising:

[0007] It includes: a hydrogen inlet valve, a hydrogen outlet valve, an anode water distribution assembly, and an anode drain valve; the hydrogen inlet valve is connected to the hydrogen inlet of the fuel cell, the hydrogen outlet of the fuel cell is connected to the inlet of the anode water distribution assembly, the first outlet of the anode water distribution assembly is connected to the anode drain valve, the second outlet of the anode water distribution assembly is connected to the hydrogen outlet valve, and the third outlet of the anode water distribution assembly is connected to the hydrogen inlet of the fuel cell.

[0008] In conjunction with the first aspect, the hydrogen discharge valve group further includes at least two or more hydrogen discharge valves of different diameters.

[0009] Secondly, a fuel cell control method is provided, including:

[0010] Fuel cell system self-test upon startup;

[0011] Get power demand command;

[0012] Determine the required power range based on the power demand command;

[0013] The corresponding hydrogen discharge valve in the hydrogen discharge group is activated according to the required power range, and hydrogen is discharged according to the preset parameters.

[0014] In conjunction with the second aspect, further compare the amplitude of the intake pressure change ΔP during exhaust. sysin Is it greater than the theoretical exhaust pressure change value P at the corresponding calibrated operating point? set1 ;

[0015] If ΔP sysin <ΔP set1 If the current hydrogen discharge valve in the hydrogen discharge group is found to be abnormal, an alarm will be issued and the system will switch to another hydrogen discharge valve in the hydrogen discharge group; otherwise, the system will maintain normal operation.

[0016] In conjunction with the second aspect, the switching principle for switching to other hydrogen discharge valves in the hydrogen discharge group valve is as follows: after an alarm, switch from the current hydrogen discharge valve to the hydrogen discharge valve in the hydrogen discharge group valve that has the closest flow rate to the current hydrogen discharge valve. If all hydrogen discharge valves in the hydrogen discharge group valve are abnormal, then the fuel cell stack will be deloaded or shut down.

[0017] In conjunction with the second aspect, furthermore, when the total number of switching times of the hydrogen exhaust valve in the hydrogen exhaust group valve reaches a preset threshold, the amplitude of the intake pressure change ΔP during exhaust is compared. sysin and the theoretical exhaust pressure change value P at the corresponding operating point set1 To determine if the hydrogen discharge valve is functioning properly, if ΔP sysin <ΔP set1 If this is the case, the hydrogen discharge valve is determined to be malfunctioning.

[0018] In conjunction with the second aspect, it also includes: determining whether the hydrogen discharge valve is malfunctioning by controlling the PWM value changes of the hydrogen injection valve or the proportional valve.

[0019] Beneficial Effects: This invention achieves precise exhaust control in low-power ranges by selecting hydrogen exhaust valves of different diameters for exhaust replacement at different power levels. Through the coordinated design of the combined valves, high-power ranges can be replaced instantly, improving hydrogen utilization in low-power ranges. Simultaneously, since the hydrogen exhaust valves typically lack operational status feedback, their functionality is effectively monitored by adjusting for changes in system inlet pressure or inlet valve control parameters. Furthermore, by using exhaust valves in a layer-by-layer manner as backups, downtime is reduced, and the overall system reliability is improved. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the fuel cell control system of the present invention;

[0021] Figure 2 The flowchart of the control method in this invention is shown below. Detailed Implementation

[0022] The present invention will now be described in further detail with reference to the accompanying drawings.

[0023] like Figures 1-2 As shown, the present invention provides a fuel cell control system, including a hydrogen inlet valve for hydrogen intake into the fuel cell stack, a hydrogen outlet valve for hydrogen discharge, an anode water separator for separating water and hydrogen, and an anode drain valve for drainage.

[0024] The hydrogen inlet valve is connected to the hydrogen inlet of the fuel cell, the hydrogen outlet of the fuel cell is connected to the inlet of the anode water separator (water separator in Figure 1), and the first outlet 1 of the anode water separator is connected to the anode drain valve. Figure 1 The anode water separator is connected to the anode drain valve, the second outlet 2 of the anode water separator is connected to the hydrogen venting valve, and the third outlet 3 of the anode water separator is connected to the hydrogen inlet of the fuel cell. The anode water separator separates the water and excess hydrogen generated after the reaction. Most of the hydrogen is sent back to the hydrogen inlet of the fuel cell stack for reuse through the first outlet 1 and the reflux assembly. The water is discharged from the third outlet 3 through the anode drain valve, and the excess hydrogen is discharged from the second outlet 2 through the hydrogen venting valve, which includes two or more hydrogen venting valves of different diameters.

[0025] The working process of this invention is mainly as follows:

[0026] The fuel cell system is powered on and performs an electrical and electronic control self-test.

[0027] The system receives a power demand command from the vehicle (assuming the fuel cell is installed on the vehicle) or other application entities.

[0028] The system determines the power demand segment based on the power demand command (the demand power is divided into several demand power segments, and each demand power segment corresponds to a hydrogen discharge valve of a certain diameter).

[0029] The appropriate hydrogen venting valve is selected based on the required power range to vent hydrogen. Under the same minimum opening time control accuracy, a suitable venting valve can ensure that hydrogen is not vented during low-power operation. This improves the hydrogen utilization rate in low-power operation and effectively prevents membrane dryness problems caused by excessive venting of the anode in low-power operation.

[0030] By comparing the amplitude of the intake pressure change ΔP during exhaust... sysin Is it greater than the theoretical exhaust pressure change value P at the corresponding calibrated operating point? set1 To determine whether the current hydrogen discharge valve is working properly;

[0031] If ΔP sysin <ΔP set1 If the current hydrogen discharge valve in the hydrogen discharge group is found to be abnormal, an alarm will be issued and the system will switch to another hydrogen discharge valve in the hydrogen discharge group. Otherwise, the system will maintain normal operation until it receives a shutdown command.

[0032] The switching principle for switching to other hydrogen venting valves in the hydrogen venting group is as follows: after an alarm, switch from the current hydrogen venting valve to the hydrogen venting valve in the hydrogen venting group with the closest flow rate to the current hydrogen venting valve (all hydrogen venting valves in the hydrogen venting group are backups for each other). If all hydrogen venting valves in the hydrogen venting group are abnormal, considering that poor anode exhaust replacement will cause insufficient hydrogen in the fuel cell stack, and in severe cases, reverse polarity damage to the core component fuel cell stack, the system can choose to report an error and reduce load to shut down.

[0033] When the total number of switching times of the hydrogen exhaust valve in the hydrogen exhaust group valve reaches the preset threshold, we need to test the hydrogen exhaust valve by comparing the amplitude of the intake pressure change ΔP during exhaust. sysin and the theoretical exhaust pressure change value P at the corresponding operating point set1 To determine if the hydrogen discharge valve is functioning properly, if ΔP sysin <ΔP set1 If the hydrogen discharge valve is found to be malfunctioning, it can also be determined by the change in the PWM value of the hydrogen injection valve or the proportional valve.

[0034] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the specific implementation of the present invention. Any modifications or equivalent substitutions that do not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A fuel cell control method, characterized in that, include: Fuel cell system self-test upon startup; Get power demand command; Determine the required power range based on the power demand command; The hydrogen discharge valve of the corresponding diameter in the hydrogen discharge group is called according to the required power range, and hydrogen is discharged according to the preset parameters. The control method further includes: Compare the amplitude of intake pressure change during exhaust. Is it greater than the theoretical exhaust pressure change value at the corresponding calibrated operating point? ; like If the current hydrogen discharge valve in the hydrogen discharge group is found to be abnormal, an alarm will be issued and the system will switch to another hydrogen discharge valve in the hydrogen discharge group; otherwise, the system will maintain normal operation.

2. The fuel cell control method according to claim 1, characterized in that, The switching principle for switching to other hydrogen discharge valves in the hydrogen discharge group is as follows: after an alarm, switch from the current hydrogen discharge valve to the hydrogen discharge valve in the hydrogen discharge group with the closest flow rate to the current hydrogen discharge valve. If all hydrogen discharge valves in the hydrogen discharge group are abnormal, then the fuel cell stack should be deloaded or shut down.

3. The fuel cell control method according to claim 1, characterized in that, Also includes: When the total number of switching times of the hydrogen exhaust valve in the hydrogen exhaust group valve reaches the preset threshold, the change in intake pressure during exhaust is compared. and the theoretical exhaust pressure change value at the corresponding operating point To determine if the hydrogen venting valve is functioning properly, if If this is the case, the hydrogen discharge valve is determined to be malfunctioning.

4. The fuel cell control method according to claim 1, characterized in that, Also includes: The PWM value of the hydrogen injection valve or proportional valve is used to determine whether the hydrogen discharge valve is malfunctioning.

5. A fuel cell control system, employing the fuel cell control method as described in any one of claims 1-4, characterized in that, include: The system includes a hydrogen inlet valve, a hydrogen outlet valve, an anode water separator assembly, and an anode drain valve. The hydrogen inlet valve is connected to the hydrogen inlet of the fuel cell, the hydrogen outlet of the fuel cell is connected to the inlet of the anode water separator assembly, the first outlet of the anode water separator assembly is connected to the anode drain valve, the second outlet of the anode water separator assembly is connected to the hydrogen outlet valve, and the third outlet of the anode water separator assembly is connected to the hydrogen inlet of the fuel cell.

6. A fuel cell control system according to claim 5, characterized in that, The hydrogen discharge valve group includes at least two or more hydrogen discharge valves of different diameters.

7. A fuel cell control system according to claim 5, characterized in that, The hydrogen inlet valve group is a set of injection valves or proportional valves.

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