A hydrogen exhaust and water exhaust valve control method based on hydrogen fuel cell inspection statistical data

Abstract

The application discloses a hydrogen exhaust and water exhaust valve control method based on hydrogen fuel cell inspection statistical data, and comprises the following steps: collecting the working voltage of a hydrogen fuel cell stack through a CVM inspection controller, and transmitting the working voltage to an FCCU controller through a channel; the FCCU controller calculates the range and variance of a single piece of the stack according to the working voltage of the stack; and the opening and closing state of the hydrogen exhaust and water exhaust valve is controlled according to the range and variance of the single piece of the stack. The application has the beneficial effects of preventing the voltage fluctuation, efficiency reduction and single piece of battery damage caused by the water accumulation of the stack.

Description

Technical Field

[0001] This invention relates to the field of hydrogen fuel cell control, and in particular to a method for controlling hydrogen discharge and drainage valves based on hydrogen fuel cell inspection statistics. Background Technology

[0002] As a power system, hydrogen fuel cell systems in the vehicle field need to operate in various environments, such as high temperature, low temperature, high humidity, low humidity, high humidity, high altitude, low altitude, etc. Currently, the mainstream technology generally controls the hydrogen discharge valve by simulating and calibrating the environment. However, due to the various environments and the different time periods of stack performance degradation, it is difficult to cover the entire life cycle and all environmental conditions, and it lacks timeliness. Summary of the Invention

[0003] To address the issues of untimely control and inability to adapt to all environmental conditions in existing hydrogen fuel cells, this application provides a hydrogen discharge and drainage valve control method based on hydrogen fuel cell inspection statistics, comprising the following steps:

[0004] S1. Collect the operating voltage of the hydrogen fuel cell stack through the CVM inspection controller and transmit it to the FCCU controller through the channel;

[0005] S2, FCCU controller calculates the range and variance of individual fuel cell stacks based on the fuel cell stack operating voltage;

[0006] S3. Control the opening and closing status of the hydrogen discharge and drainage valves based on the range and variance of individual fuel cell stack pieces.

[0007] The beneficial effects provided by this invention are: preventing voltage fluctuations, efficiency reduction, and damage to individual batteries caused by water accumulation in the battery. Attached Figure Description

[0008] Figure 1 This is a flowchart of the method of the present invention. Detailed Implementation

[0009] To make the objectives, technical solutions, and advantages of the present invention clearer, the embodiments of the present invention will be further described below with reference to the accompanying drawings.

[0010] The relevant terms are explained below:

[0011] The CVM (Cell Fuel Cell Monitoring Module) controller is an important component of fuel cell engine system monitoring. This controller can accurately detect the voltage of individual cells in the fuel cell stack in real time and perform real-time analysis and processing of the monitored individual cell voltage data.

[0012] The FCCU controller is the assembly controller of the fuel cell engine system (FCE), which is involved in the management, coordination and communication of all aspects of the fuel cell system.

[0013] It should be noted that this invention relates to four components inside a hydrogen fuel cell system: the stack body, the CVM inspection controller, the FCCU controller, and the hydrogen discharge and drainage valve.

[0014] The fuel cell stack itself: as the controlled target, it ensures that the fuel cell stack operates in a high-efficiency and reliable state, and prevents voltage fluctuations, low efficiency, and reliability failures caused by fuel cell stack flooding.

[0015] CVM Inspection Controller: Collects voltage data from a single or multiple sections of the fuel cell stack;

[0016] Hydrogen venting and draining valve: This valve drains water generated by the fuel cell reactor into the system, preventing flooding. It also removes impurities from the hydrogen path (nitrogen from the air side and hydrogen that is not 100% pure).

[0017] Please refer to Figure 1 , Figure 1 This is a schematic diagram of the method flow of the present invention.

[0018] This invention provides a method for controlling hydrogen discharge and drainage valves based on statistical data from hydrogen fuel cell inspections, comprising the following steps:

[0019] S1. Collect the operating voltage of the hydrogen fuel cell stack through the CVM inspection controller and transmit it to the FCCU controller through the channel;

[0020] The hydrogen fuel cell stack has a total of M cells, with the first cell being M1, the nth cell being M... n The CVM inspection controller has N channels, with the first channel being N1 and the nth channel being N. n Where M = x + 2y, N = x + y; x is the number of single-piece inspections of the fuel cell stack, and y is the number of double-piece inspections of the fuel cell stack.

[0021] Generally, the first and last few plates of each fuel cell stack are inspected individually, while the remaining middle sections are inspected in groups of multiple plates.

[0022] Therefore, M = x + 2y, N = x + y; x is the number of single-piece inspections of the fuel cell stack, and y is the number of double-piece inspections of the fuel cell stack.

[0023] The FCCU sequentially parses the CVM channel data N(x+y) into M(x+2y). That is, when it is a dual detection, it should be divided by 2 and then expressed as the voltage values ​​of the two chips respectively.

[0024] S2, FCCU controller calculates the range and variance of individual fuel cell stacks based on the fuel cell stack operating voltage;

[0025] It should be noted that the formula for calculating the range of a single cell in the fuel cell stack is:

[0026] U range =U max -U min

[0027] Among them, U range U represents the single-chip range of the fuel cell stack. max Indicates a single M-chip in the fuel cell stack n The current real-time voltages U1, U2, ..., U of the corresponding hydrogen fuel cell stack x+2y The maximum value in, U min Indicates a single M-chip in the fuel cell stack n The preceding value corresponds to the minimum real-time voltage of the hydrogen fuel cell stack.

[0028] The formula for calculating the variance of a single cell in a fuel cell stack is:

[0029] U variance =[(U1-U avg ) 2 +(U2-U avg ) 2 ……+(M (x+2y) -M avg ) 2 ] / (x+2y)

[0030] Among them, U variance U represents the variance of a single cell in the fuel cell stack. avg Indicates a single M-chip in the fuel cell stack n The average real-time voltage of the corresponding hydrogen fuel cell stack.

[0031] S3. Control the opening and closing status of the hydrogen discharge and drainage valves based on the range and variance of individual fuel cell stack pieces.

[0032] It should be noted that the internal processing of the FCCU controller is as follows:

[0033] Firstly, the control is divided into two modes: on mode and off mode.

[0034] In shutdown mode, the hydrogen discharge and drain valves are normally closed.

[0035] In startup mode, there are three states: powering on, running stably, and powering off.

[0036] Among them, control based on variance and range is applied to stable operating conditions, that is, when the vehicle is operating at constant power.

[0037] Specifically, the process of controlling the hydrogen discharge and drainage valve based on the range in step S3 is as follows:

[0038] The hydrogen discharge and drainage valve is a normally closed valve. When the vehicle is operating at a constant power:

[0039] S311, If ​​U range >U avg *a, then the hydrogen discharge valve opens for t1 seconds and closes for t2 seconds, t1>t2, at which point U range Decrease, determine U range Is it greater than U? avg *b, where a, b, t1, t2 are all preset values, and a > b, a, b ∈ (0, 1). If so, then one instance of exceeding the limit will be recorded.

[0040] S312. Continue to open the hydrogen discharge valve for t1 seconds and close it for t2 seconds;

[0041] S313. Repeat steps S311 to S312 three times. If the records exceed the limit three times in a row, report the fault. Otherwise, repeat steps S311 to S312 to control the hydrogen discharge and drainage valve to keep the vehicle operating at a constant power.

[0042] In this invention, a is 0.3, b is 0.2, t1 is 2, and t2 is 1.

[0043] The process of controlling the hydrogen discharge valve based on variance in step S3 is as follows:

[0044] The hydrogen discharge and drainage valve is a normally closed valve. When the vehicle is operating at a constant power:

[0045] Open the hydrogen discharge valve for t3 seconds each time, and record t4 seconds as one cycle, where t3 > 3 * t4. When U variance The change value is lower than the current U variance If the d% continuity occurs for more than 3 cycles, then the current U is considered to be... variance Minimum value U has been reached variance_min When the current U variance >U variance_min When *c is used, the hydrogen discharge valve remains open; otherwise, the hydrogen discharge valve closes. Here, c is a preset value.

[0046] In this invention, t3 is 1, t4 is 0.1, c is 2, and d is 10;

[0047] It should be noted that this application has set a protection value for the closing time of the hydrogen discharge and drainage valve;

[0048] In an ambient temperature laboratory, the shutdown time was calibrated at various power levels, starting from 10%, 20%, ..., 100% of the rated power, and then recorded as T1, T2, ..., T. n The environmental control settings are as follows: ambient temperature 45℃±2℃, relative humidity ≥95%. variance_minConsistent with the above sampling method requirements, the maximum time t for the hydrogen discharge and drainage valves to be closed at each power point is: t = T n *(1+15%).

[0049] When the system is under load change, i.e., starting up, shutting down, or experiencing other load changes (the vehicle sends a power change request to the system), the hydrogen venting and draining valves open and close according to the T1, T2, T3…Tn sequence described above. Once the system output power reaches ±95% of the requested power, and the hydrogen venting and draining valves open once, the system opens and closes again according to the above sequence.

[0050] It operates in a constant power mode.

[0051] In summary, the beneficial effects of this invention are: enabling the fuel cell to operate normally throughout its entire life cycle and under all environmental conditions, while also protecting the fuel cell stack itself after performance degradation or damage, and improving efficiency during normal operation.

[0052] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for controlling hydrogen discharge and drainage valves based on statistical data from hydrogen fuel cell inspections, characterized in that: Includes the following steps: S1. Collect the operating voltage of the hydrogen fuel cell stack through the CVM inspection controller and transmit it to the FCCU controller through the channel; S2, FCCU controller calculates the range and variance of individual fuel cell stacks based on the fuel cell stack operating voltage; S3. Control the opening and closing status of the hydrogen discharge and drainage valves based on the range and variance of individual fuel cell stack pieces; The total number of single cells in the hydrogen fuel cell stack is: M The first piece is M 1, no. n The film is M n The number of channels for the CVM inspection controller is: N The first channel is N 1, no. n The channel is N n ;in M = x +2 y , N = x + y ; x This refers to the number of individual cells in the fuel cell stack that are inspected. y The logarithm of the dual-plate, single-detection fuel cell stack; The formula for calculating the range of a single cell in a fuel cell stack is: U range = U max - U min in, U range Indicates the single-piece range of the fuel cell stack. U max Indicates a single piece of fuel cell stack M n Current real-time voltage of the corresponding hydrogen fuel cell stack U 1. U 2、...、 U x+2y The maximum value in, U min Indicates a single piece of fuel cell stack M n The minimum real-time voltage of the corresponding hydrogen fuel cell stack; The formula for calculating the variance of a single cell in a fuel cell stack is: U variance =[（ U 1- U avg ） 2 +（ U 2- U avg ） 2 ……+（ U （x+2y） - U avg ） 2 ] / ( x +2 y ) in, U variance This represents the variance of a single fuel cell stack. U avg Indicates a single piece of fuel cell stack M n The average real-time voltage of the corresponding hydrogen fuel cell stack; The process of controlling the hydrogen discharge and drainage valve based on the range in step S3 is as follows: The hydrogen discharge and drainage valve is a normally closed valve. When the vehicle is operating at a constant power: S311, if U range > U avg * a Then the hydrogen discharge and drain valve will open. t 1 second, close t 2 seconds t 1> t 2, at this time U range Decline, judgment U range Is it greater than U avg * b ,in a , b , t 1, t Both 2 are preset values, and a > b , a , b If ∈(0,1), then record one instance of exceeding the limit; S312, Continue to open the hydrogen discharge and drain valve. t 1 second, close t 2 seconds; S313. Repeat steps S311 to S312 three times. If the records exceed the limit three times in a row, report the fault. Otherwise, repeat steps S311 to S312 to control the hydrogen discharge valve to keep the vehicle operating at a constant power. The process of controlling the hydrogen discharge valve based on variance in step S3 is as follows: The hydrogen discharge and drainage valve is a normally closed valve. When the vehicle is operating at a constant power: Open the hydrogen discharge valve, and the opening time should be specified each time. t 3 seconds, with t A 4-second recording cycle is defined as one period. t 3>3* t 4. When U variance The change value is lower than the current U variance of d% If three or more consecutive cycles occur, then the current period is considered to be... U variance Minimum value has been reached U variance_min When the current U variance > U variance_min * c When the hydrogen discharge valve remains open, it closes; otherwise, it remains closed. c This is the default value.

2. The hydrogen discharge and drainage valve control method based on hydrogen fuel cell inspection statistics as described in claim 1, characterized in that: The longest time the hydrogen discharge valve is closed t The calculation formula is as follows: t = T n *（1+15%） in, T n The closing time of the hydrogen discharge and drain valve is pre-calibrated at 100% rated power in an ambient temperature laboratory.

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