A fuel cell system low temperature start-up control method and apparatus

Abstract

The application discloses a kind of fuel cell system low temperature starting control method and its device, it is related to the technical field of fuel cell.Its technical points are: including fuel cell stack and hydrogen supply system, water pump is connected between the circuit of cooling liquid inlet and cooling liquid outlet of fuel cell stack, DCF and load are connected between the high voltage positive pole and negative pole of fuel cell stack, air supply system includes filter, filter is sequentially connected with flowmeter, compressed gas module and humidification module, first throttle and second throttle are connected between the connecting circuit of humidification module and fuel cell stack, first throttle and second throttle are connected in parallel, and control module is additionally provided, control module is electrically connected to water pump, compressed gas module, first throttle and second throttle.The application has the advantages that: without increasing external heating component, by controlling air excess coefficient, improving start-up process polarization resistance heating, reducing energy consumption, improving fuel cell system efficiency.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of fuel cells, in particular to a fuel cell system low-temperature starting control method and device thereof. BACKGROUND

[0002] Hydrogen fuel cell systems have zero emissions and fast hydrogen refueling advantages, can effectively solve the problems of long charging time and short cruising range of lithium batteries, and are a new energy direction with broad development prospects.

[0003] A hydrogen fuel cell system is usually composed of a stack, a hydrogen system, an air system, a thermal management system, and a control system. Due to the working mechanism of fuel cells, a large amount of water is generated during operation. When the fuel cell starts at zero temperature, the water generated by the internal reaction of the stack will quickly freeze and block the air supply channel, resulting in low-temperature starting failure. In severe cases, it can damage the internal structure of the stack and cause performance and life attenuation of the fuel cell system. Therefore, the fuel cell must have good low-temperature cold starting characteristics.

[0004] The existing low-temperature starting method of fuel cells mainly includes starting by heating through an external heating component or relying on the heat generated by the stack itself. In particular, auxiliary heating through an external heating component is a common way in practical applications.

[0005] For example, Chinese patent CN115498219A discloses a fuel cell system and a low-temperature starting control method thereof. When the ambient temperature is low, the battery pack supplies power to the heating device to start the electric heating component and the warm air component to warm up the fuel cell and warm air, thereby quickly increasing the temperature inside the fuel cell stack and quickly starting the fuel cell stack.

[0006] The above-mentioned prior art scheme has the following defects: the low-temperature starting scheme through an external heating component needs to start the cooling cycle during heating. Due to the low ambient temperature, the energy consumption for heating is high, which reduces the efficiency of the fuel cell system. At the same time, the cooling circuit design of the external heating component scheme is complex and the cost is also high. SUMMARY

[0007] In view of the deficiencies of the prior art, the purpose of the present application is to provide a fuel cell system low-temperature starting control method and device thereof, which has the advantages of not needing to increase an external heating component, controlling the air excess coefficient, improving the polarization internal resistance heating during starting, reducing energy consumption, and improving the efficiency of the fuel cell system. At the same time, the cooling circuit structure of the present technical scheme is simple, the control strategy is easy to implement, and it has universality. By adjusting the control parameters, it can adapt to different fuel cell systems.

[0008] The above object of the present application is realized by the following technical solutions.

[0009] A low-temperature starting control method of a fuel cell system, comprising the following steps:

[0010] (1) A plurality of temperature sensors are arranged on the stack system, and an average value T0 represents the temperature of the stack at this time, and the temperature value is used to determine the starting process of the fuel cell system;

[0011] (2) When T0>T1, T1 is a set starting threshold temperature, the fuel cell system can be normally started, and the control module directly enters the normal starting process;

[0012] (3) When T0≤T1, the system enters the low-temperature starting mode process, and the system sets two low-temperature starting modes, wherein when the temperature T0≤T2, T2 is a set temperature threshold of the low-temperature starting mode 1, enters the low-temperature starting mode 1, the control module controls the hydrogen supply and oxygen supply of the fuel cell system, controls the opening of the first throttle valve (7) of the air circuit, and the opening angle is θ1, the heat is generated by increasing the polarization resistance of the anode and cathode of the stack to heat the fuel cell system, when the temperature rising rate is lower than the set value, the opening of the first throttle valve (7) is further increased, and the opening angle is greater than θ1, the temperature rising rate is improved, and the temperature rising rate is improved until the temperature rising rate meets the set value;

[0013] When T0>T2, T2 is a set temperature threshold of the low-temperature starting mode 1, enters the low-temperature starting mode 2, the water pump works at the lowest speed, supplies hydrogen and oxygen to the fuel cell system according to the preset value, adjusts the angle of the second throttle valve to θ2, and ensures that the amount of oxygen entering the stack is lower than the target value, when the temperature of the stack rises to T3, T3 is a set heating stop temperature threshold, the first throttle valve is closed, the low-temperature starting mode is ended, and the system enters the normal working state;

[0014] (4) When T2

[0015] A kind of fuel cell system low temperature start control device, including fuel cell stack and hydrogen supply system, water pump is connected between the cooling liquid inlet of fuel cell stack and the circuit of cooling liquid outlet, DCF is connected between the high voltage positive pole and negative pole of fuel cell stack and load, air supply system includes filter, the filter is sequentially connected with flow meter, compressed gas module and humidification module, first throttle and second throttle are connected between the connecting circuit of humidification module and fuel cell stack, first throttle and second throttle are connected in parallel between first throttle and second throttle, control module is additionally provided, the control module is electrically connected to water pump, compressed gas module, first throttle and second throttle.

[0016] In summary, the present application includes at least one of the following beneficial technical effects:

[0017] 1. Without the need to add external heating components, the air excess coefficient is controlled to improve the polarization resistance heating in the starting process, reduce energy consumption and improve the efficiency of the fuel cell system.

[0018] 2. At the same time, the cooling circuit structure of the technical solution is simple and the control strategy is easy to implement, and it is universal, which can be adapted to different fuel cell systems by adjusting the control parameters. BRIEF DESCRIPTION OF DRAWINGS

[0019] Fig. 1 is the device principle diagram of the present application;

[0020] Fig. 2 is the control flow chart of the present application;

[0021] Fig. 3 is the layout of the temperature sensor in the present application.

[0022] Reference signs: 1, temperature sensor; 2, water pump; 3, filter; 4, flow meter; 5, compressed gas module; 6, humidification module; 7, first throttle; 8, second throttle. DETAILED DESCRIPTION

[0023] The present application will be further described in detail below in conjunction with the drawings.

[0024] As Figs. 1-3 shown, a kind of fuel cell system low temperature start control method is disclosed in the present application,

[0025] (1) multiple temperature sensors 1 are arranged on the system of electric pile, and average value T0 represents the temperature of electric pile at this time, which is used to judge the starting flow of fuel cell system. The number of temperature sensors 1 here is set according to demand, and three in the figure.

[0026] (2) When T0>T1, T1 is the set starting threshold temperature, the fuel cell system can be started normally, and the control module directly enters the normal starting process;

[0027] (3) When T0≤T1, the system enters the low-temperature starting mode process, and the system sets two low-temperature starting modes. When T0≤T2, T2 is the temperature threshold of the set low-temperature starting mode 1, the low-temperature starting mode 1 is entered, in order to ensure that the stack is not affected by the ambient temperature, the water pump 2 does not work, the control module controls the hydrogen and oxygen supply of the fuel cell system according to the preset parameters, controls the first throttle valve 7 of the air circuit to be opened, and the opening angle is θ1, the heat is generated by increasing the polarization resistance of the anode and cathode of the stack to heat the fuel cell system, when the temperature rise rate is lower than the set value, the opening of the first throttle valve 7 is further increased, the opening angle is greater than θ1, the temperature rise rate is improved, until the temperature rise rate meets the set value;

[0028] When T0>T2, T2 is the temperature threshold of the set low-temperature starting mode 1, the low-temperature starting mode 2 is entered, in order to avoid the problem of overheating of the fuel cell system, the water pump 2 works at the lowest speed, the hydrogen and oxygen supply of the fuel cell system is carried out according to the preset value, the angle of the second throttle valve 8 is adjusted to θ2, and the amount of oxygen entering the stack is ensured to be lower than the target value, when the stack temperature rises to T3, T3 is the set heating stop temperature threshold, the first throttle valve 7 is closed, the low-temperature starting mode is ended, and the system enters the normal working state;

[0029] (4) When T2

[0030] A kind of fuel cell system low temperature start control device, including fuel cell stack and hydrogen supply system, the connection between the two is available immediately.The water pump 2 is connected between the cooling liquid inlet and the outlet of the cooling liquid circuit of fuel cell stack, the flow of cooling liquid is controlled by the water pump 2 set, the high voltage positive and negative electrode of fuel cell stack is connected with DCF and load, air supply system includes filter 3, filter 3 is connected with flowmeter 4, compressed gas module 5 and humidification module 6 in turn, humidification module 6 is connected with the first air throttle 7 and second air throttle 8 between the connection circuit of fuel cell stack, the first air throttle 7 and second air throttle 8 are in parallel, the first air throttle 7 and second air throttle 8 set can control air circuit, to carry out temperature regulation.Another control module is provided, and the control module is electrically connected to the water pump 2, compressed gas module 5, first air throttle 7 and second air throttle 8.The structures and modules not mentioned here are the same as or substantially the same as those in the prior art, and only the parts different from the prior art are recorded in this technical solution.

[0031] The embodiments of the present embodiment are the preferred embodiments of the present application, and are not limited to the protection scope of the present application, so that: equivalent changes made according to the structure, shape, principle of the present application should be covered within the protection scope of the present application.

Claims

1. A fuel cell system low temperature startup control method characterized by, The method is applied to a control device, the device comprising a fuel cell stack and a hydrogen supply system, a water pump (2) being connected between the inlet and the outlet of the cooling liquid circuit of the fuel cell stack, a DCF being connected between the high-voltage positive and negative electrodes of the fuel cell stack, and a load, the air supply system comprising a filter (3), the filter (3) being connected in turn with a flow meter (4), a compressed gas module (5), and a humidification module (6), a first throttle valve (7) and a second throttle valve (8) being connected between the humidification module (6) and the connection circuit of the fuel cell stack, the first throttle valve (7) and the second throttle valve (8) being connected in parallel, the first throttle valve (7) and the second throttle valve (8) being used to control the air circuit to regulate the temperature, and a control module being further provided, the control module being electrically connected to the water pump (2), the compressed gas module (5), the first throttle valve (7), and the second throttle valve (8); the method comprising: (1) arranging a plurality of temperature sensors (1) on the stack system, taking the average value T0 to represent the temperature of the stack at this time, and using the temperature value to determine the fuel cell system starting process; (2) when T0>T1, T1 being a set starting threshold temperature, the fuel cell system can be normally started, and the control module directly enters the conventional starting process; (3) when T0≤T1, the system enters a low-temperature starting process, and the system sets two low-temperature starting modes, wherein when T0≤T2, T2 being a set temperature threshold of low-temperature starting mode 1, entering the low-temperature starting mode 1, the water pump (2) does not work, the control module controls the hydrogen and oxygen supply amount of the fuel cell system, the first throttle valve (7) of the air circuit is opened, the opening angle is θ1, the heat production is increased by increasing the polarization resistance of the anode and cathode of the stack to heat the fuel cell system, when the temperature rise rate is lower than the set value, the first throttle valve (7) opening is further increased, the opening angle is greater than θ1, the temperature rise rate is improved, and the temperature rise rate is until the temperature rise rate meets the set value; when T0>T2, T2 being a set temperature threshold of low-temperature starting mode 1, entering the low-temperature starting mode 2, the water pump (2) works at the lowest speed, the hydrogen and oxygen supply of the fuel cell system is carried out according to the preset value, the angle of the second throttle valve (8) is adjusted to θ2, and the oxygen amount entering the stack is ensured to be lower than the target value, when the stack temperature rises to T3, T3 being a set heating stop temperature threshold, the first throttle valve (7) is closed, the low-temperature starting mode is ended, and the system enters the normal working state; (4) when T2

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