Control method of exhaust and drainage valve of fuel cell system

Abstract

The invention discloses a control method of an exhaust and drain valve of a fuel cell system. The control method comprises the following steps: respectively setting an exhaust valve and a drain valve to be periodically and intermittently opened and closed; selecting a drain valve as a control target; judging whether the drainage valve is opened or not in the current period; and if the drain valve is opened in the current period, the exhaust valve opening and closing control signal is logically processed and closed through the combinational logic gate. The exhaust valve and the drainage valve are prevented from being opened at the same time; and a series of adverse effects such as hydrogen consumption increase, hydrogen pressure fluctuation increase and even fault shutdown of the fuel cell system are avoided.

Description

Technical Field

[0001] The present invention belongs to the field of new energy fuel cell systems, and in particular, relates to a method for controlling an exhaust and drain valve of a fuel cell system. Background Art

[0002] Fuel cells are devices that convert the chemical energy of fuel directly into electrical energy. They are highly efficient and pollution-free, and have great development potential and application prospects. Currently, the most mature and widely used fuel cell is the proton exchange membrane fuel cell, which works by converting chemical energy into electrical energy through the electrochemical reaction of hydrogen and oxygen to generate water and electrons. The fuel cell system mainly includes several modules, such as the hydrogen subsystem, air subsystem, hydrothermal subsystem, and electrical subsystem. The hydrogen subsystem usually contains the control logic of many actuators, such as hydrogen inlet valve, proportional valve, hydrogen circulation pump, exhaust valve, drain valve, etc. The main function of the exhaust valve is to discharge the waste gas after the reaction to prevent the impurities from blocking the membrane electrode and causing a short circuit; the main function of the drain valve is to take out the water vapor to prevent the membrane electrode from being flooded.

[0003] At present, the common control method of exhaust and drain valves in fuel cell systems is: the exhaust valve and drain valve are set to open and close periodically and intermittently, and the opening time and closing time are set as calibration quantities, which is convenient for calibration and debugging in actual application to meet the specific needs of the fuel-electric system under different working conditions. However, the exhaust valve and the drain valve are both opened and closed periodically, and they will inevitably be opened at the same time if the time is long enough, which will increase the hydrogen consumption of the system during operation and increase the hydrogen pressure fluctuation, affecting the control parameters of the hydrogen pressure closed-loop control, and in severe cases, it will trigger a fault and cause the system to shut down. Summary of the invention

[0004] In view of the problem that the exhaust valve and drain valve of the existing fuel cell system are both opened and closed periodically, and will inevitably be opened at the same time under long-term operation, the present invention provides a control method for the exhaust and drain valve of the fuel cell system.

[0005] In order to achieve the above technical objectives, the technical solution adopted by the present invention is as follows:

[0006] A method for controlling an exhaust and drain valve of a fuel cell system comprises the following steps:

[0007] S1. Set the exhaust valve and drain valve to open and close periodically and intermittently;

[0008] S2, select the drain valve as the control target;

[0009] S3, determining whether the drain valve is open in the current cycle;

[0010] S4. If the drain valve is open in the current cycle, the exhaust valve opening and closing control signal is logically processed and closed through the combination logic gate.

[0011] Furthermore, in step S1, when the exhaust valve and the drain valve are set to be periodically intermittently opened and closed, the opening time and closing time of the exhaust valve and the drain valve are simultaneously set to calibrated values.

[0012] Furthermore, in step S1, while setting the opening time and closing time of the exhaust valve and the drain valve to calibrated values, the opening and closing control signals of the exhaust valve and the drain valve are outputted respectively as hard-line driving signals for controlling the two switch valves.

[0013] Furthermore, in step S2, the drain valve opening and closing control signal is used as an input signal of the exhaust valve control module, and the detailed steps of taking the periodic opening and closing of the drain valve as the control target include:

[0014] First, the drain valve opening and closing control signal and the exhaust valve opening and closing control signal are logically processed through a NAND gate to obtain a processed Boolean signal;

[0015] The signal and the exhaust valve opening and closing control signal are then logically processed through an AND gate to obtain the final required exhaust valve opening and closing control signal.

[0016] In this way, it can be ensured that the drain valve is always opened and closed normally and cyclically according to the set opening and closing time. When the exhaust valve is opened at the same time as the drain valve in a certain cycle, the exhaust valve is controlled to be forcibly closed through the above logic processing to avoid the cycle in which the two valves are opened at the same time. The exhaust valve is still opened and closed normally and cyclically according to the set opening and closing time during the rest of the time.

[0017] Furthermore, if the drain valve is closed in the current cycle, the exhaust valve opening and closing control signal is logically processed to open and close intermittently in a normal periodic manner.

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

[0019] The exhaust and drain valves are set to open and close intermittently periodically, with the drain valve as the main control target. Logical processing is performed through combined logic gates to control the exhaust valve to close within the drain valve opening period to avoid the exhaust valve and the drain valve being opened at the same time. This avoids a series of adverse effects on the fuel cell system, such as increased hydrogen consumption, increased hydrogen pressure fluctuations, and even malfunction shutdown. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is an overall flow chart of a method for controlling an exhaust and drain valve of a fuel cell system in an embodiment of the present invention. DETAILED DESCRIPTION

[0021] In order to facilitate the understanding of those skilled in the art, the present invention is further described below in conjunction with embodiments and drawings. The contents mentioned in the implementation modes are not intended to limit the present invention.

[0022] like Figure 1 As shown, this embodiment provides a method for controlling an exhaust and drain valve of a fuel cell system, comprising the steps of:

[0023] S1. Set the exhaust valve and drain valve to open and close periodically and intermittently;

[0024] S2, select the drain valve as the control target;

[0025] S3, determining whether the drain valve is open in the current cycle;

[0026] S4. If the drain valve is open in the current cycle, the exhaust valve opening and closing control signal is logically processed and closed through the combination logic gate.

[0027] In step S1, when the exhaust valve and the drain valve are set to be periodically opened and closed intermittently, the opening time and closing time of the exhaust valve and the drain valve are set to be calibrated values.

[0028] In step S1, while setting the opening time and closing time of the exhaust valve and the drain valve to calibrated values, the opening and closing control signals of the exhaust valve and the drain valve are outputted respectively as hard-line driving signals for controlling the two switch valves.

[0029] In step S2, the drain valve opening and closing control signal is used as the input signal of the exhaust valve control module. The detailed steps with the periodic opening and closing of the drain valve as the control target include:

[0030] First, the drain valve opening and closing control signal and the exhaust valve opening and closing control signal are logically processed through a NAND gate to obtain a processed Boolean signal;

[0031] The signal and the exhaust valve opening and closing control signal are then logically processed through an AND gate to obtain the final required exhaust valve opening and closing control signal.

[0032] In this way, it can be ensured that the drain valve always opens and closes normally according to the set opening and closing time. When the exhaust valve opens at the same time as the drain valve in a certain cycle, the exhaust valve is forced to close through the above logic processing to avoid the cycle of the two valves opening at the same time. The exhaust valve still opens and closes normally according to the set opening and closing time at other times. Table 1 of the above combinational logic gates is shown below.

[0033] Table 1 Truth table of combinational logic gates

[0034]

[0035]

[0036] When the exhaust valve is selected as the control target in step S2, in step S3, it is determined whether the drain valve is open in the current cycle. If it is open, the process goes to step S4, and the exhaust valve opening and closing control signal is logically processed by the combination logic gate to close the exhaust valve; if the drain valve is closed in the current cycle, the exhaust valve opening and closing control signal is logically processed to open and close intermittently in a normal periodic manner.

[0037] Compared with the prior art, the present invention has the following beneficial effects:

[0038] The exhaust and drain valves are set to open and close intermittently periodically, with the drain valve as the main control target. Logical processing is performed through combined logic gates to control the exhaust valve to close within the drain valve opening period to avoid the exhaust valve and the drain valve being opened at the same time. This avoids a series of adverse effects on the fuel cell system, such as increased hydrogen consumption, increased hydrogen pressure fluctuations, and even malfunction shutdown.

[0039] The above is a detailed introduction to a control method for an exhaust and drain valve of a fuel cell system provided by the present application. The description of the specific embodiment is only used to help understand the method and its core idea of ​​the present application. It should be pointed out that for ordinary technicians in this technical field, without departing from the principles of the present application, several improvements and modifications can be made to the present application, and these improvements and modifications also fall within the scope of protection of the claims of the present application.

Claims

1. A method for controlling an exhaust and drain valve of a fuel cell system, characterized in that: Includes steps: The exhaust valve and the drain valve are respectively set to open and close intermittently periodically; Select the drain valve as the control target; Determine whether the drain valve is open in the current cycle; If the drain valve is open in the current cycle, the exhaust valve opening and closing control signal is logically processed and closed through the combinational logic gate.

2. A method for controlling an exhaust and drain valve of a fuel cell system according to claim 1, characterized in that: In step S1, when the exhaust valve and the drain valve are set to be periodically opened and closed intermittently, the opening time and closing time of the exhaust valve and the drain valve are set to be calibrated values.

3. A method for controlling an exhaust and drain valve of a fuel cell system according to claim 2, characterized in that: In step S1, while setting the opening time and closing time of the exhaust valve and the drain valve to calibrated values, the opening and closing control signals of the exhaust valve and the drain valve are outputted respectively as hard-line driving signals for controlling the two switch valves.

4. A method for controlling an exhaust and drain valve of a fuel cell system according to claim 3, characterized in that: In step S2, the drain valve opening and closing control signal is used as the input signal of the exhaust valve control module. The detailed steps with the periodic opening and closing of the drain valve as the control target include: First, the drain valve opening and closing control signal and the exhaust valve opening and closing control signal are logically processed through a NAND gate to obtain a processed Boolean signal; The signal and the exhaust valve opening and closing control signal are then logically processed through an AND gate to obtain the final required exhaust valve opening and closing control signal.

5. A method for controlling an exhaust and drain valve of a fuel cell system according to claim 4, characterized in that: If the drain valve is closed in the current cycle, the exhaust valve opening and closing control signal is logically processed to open and close intermittently in a normal periodic manner.

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