Temperature monitoring method of gas circuit, program product and fuel cell system

Abstract

The invention relates to a temperature monitoring method for a gas circuit of a fuel cell system, comprising the steps of: acquiring a first operating parameter of a gas supply unit in the gas circuit, calculating a first gas temperature and a gas flow rate of a reaction gas supplied by the gas supply unit according to the first operating parameter, the reaction gas is supplied to the heat exchange unit in the gas loop; acquiring a second operating parameter of a coolant supply unit in the coolant circuit, calculating a coolant flow rate by the coolant according to the second operating parameter, the coolant being supplied to the heat exchange unit; acquiring a coolant temperature of the coolant; a second gas temperature of a reactant gas flowing out of the heat exchange unit is calculated from the first gas temperature, the gas flow rate, the coolant flow rate, and the coolant temperature, the reactant gas being supplied to the fuel cell stack and the second gas temperature corresponding to an intake gas temperature of the fuel cell stack. The invention also relates to a corresponding computer program product and a fuel cell system. The intake air temperature of the fuel cell stack can be monitored in a simple and cost-effective manner.

Description

Technical Field

[0001] This invention relates to the field of fuel cell technology, and in particular to a method for temperature monitoring of the gas circuit in a fuel cell system. The invention also relates to a corresponding computer program product and a corresponding fuel cell system. Background Technology

[0002] A fuel cell is a highly efficient power generation device that directly converts the chemical energy in the anode and cathode gases into electrical energy through an electrochemical reaction without combustion. The reaction products are mainly water and virtually no harmful gases are emitted. Therefore, fuel cells have significant advantages in high energy conversion efficiency and clean environmental protection, and are widely used in vehicles and power generation facilities. Here, a fuel cell system includes a fuel cell stack consisting of multiple fuel cells, a cathode gas circuit for supplying cathode gas (such as air) to the fuel cell stack, and an anode gas circuit for supplying anode gas (such as hydrogen) to the fuel cell stack.

[0003] During fuel cell system operation, to optimize the reaction rate and output power, reactant gases, especially air, are typically compressed and supplied to the corresponding electrodes. This compression process increases the kinetic energy of the reactant gases and generates a large amount of heat, causing their temperature to rise, sometimes reaching 200°C. To prevent the temperature of the compressed gas from exceeding the allowable threshold and to ensure stable operation of the fuel cell system, a heat exchange unit, such as an intercooler, is installed in the gas circuit. The coolant supplied by the coolant supply unit absorbs the heat from the reactant gases and cools the compressed reactant gases as it flows through the heat exchange unit.

[0004] However, during the actual operation of a fuel cell system, problems such as abnormal cooling pipes, abnormal water pumps, and abnormal compressor control may occur. This can lead to insufficient heat dissipation efficiency of the heat exchange unit to ensure that the temperature of the reactant gas is below the temperature threshold, which has an unavoidable adverse effect on the working performance and lifespan of the fuel cell stack. Summary of the Invention

[0005] Therefore, the purpose of this invention is to propose an improved temperature monitoring method for the gas loop of a fuel cell system. This method can easily and cost-effectively monitor the inlet temperature of the fuel cell stack, promptly detect overheating of the reactant gas, thereby enabling the fuel cell system to respond quickly and maximizing the performance and lifespan of the fuel cell stack.

[0006] According to a first aspect of the present invention, a method for monitoring the temperature of a gas loop in a fuel cell system is provided, wherein the temperature monitoring method includes at least the following steps:

[0007] S1: Obtain the first operating parameters of the gas supply unit in the gas circuit and calculate the first gas temperature and gas flow rate of the reaction gas supplied by the gas supply unit based on the first operating parameters. The reaction gas is supplied to the heat exchange unit in the gas circuit.

[0008] S2: Obtain the second operating parameters of the coolant supply unit in the coolant circuit, calculate the coolant flow rate of the coolant supplied by the coolant supply unit based on the second operating parameters, and the coolant is also supplied to the heat exchange unit;

[0009] S3: The coolant temperature is obtained by a first temperature sensor before the coolant reaches the heat exchange unit;

[0010] S4: Calculate the second gas temperature of the reaction gas flowing out of the heat exchange unit based on the first gas temperature, the gas flow rate, the coolant flow rate, and the coolant temperature. The reaction gas is supplied to the fuel cell stack of the fuel cell system, and the second gas temperature corresponds to the inlet temperature of the fuel cell stack.

[0011] Compared to existing technologies, in the temperature monitoring method according to the present invention, the first gas temperature and gas flow rate of the reactant gas are calculated based on the first operating parameters of the gas supply unit, the coolant flow rate is calculated based on the second operating parameters of the coolant supply unit, and the coolant temperature before reaching the heat exchange unit is obtained. Based on the calculated first gas temperature, gas flow rate, coolant flow rate, and the obtained coolant temperature, the second gas temperature of the reactant gas flowing out of the heat exchange unit can be calculated. This second gas temperature corresponds to the inlet temperature of the fuel cell stack. Thus, the temperature of the reactant gas can be monitored without changing the overall structure of the existing fuel cell system, without the need to install additional temperature sensors in the gas loop. This enables real-time monitoring of the inlet temperature in a simple and cost-effective manner, allowing for timely response measures when overheating is detected, thereby avoiding the adverse effects of overheated reactant gas on the fuel cell stack and improving the working performance and service life of the fuel cell system.

[0012] According to a second aspect of the present invention, a computer program product is provided, comprising a computer program, wherein when the computer program is executed by one or more processors, the processors are capable of executing the temperature monitoring method according to the present invention.

[0013] According to a third aspect of the present invention, a fuel cell system is provided, wherein the fuel cell system comprises at least:

[0014] - Fuel cell stack;

[0015] - A gas circuit, which is connected to the intake manifold of the fuel cell stack, wherein at least a gas supply unit and a heat exchange unit are arranged in the gas circuit;

[0016] - A coolant circuit, connected to the heat exchange unit, wherein at least a coolant supply unit and a first temperature sensor are arranged in the coolant circuit; and

[0017] - A control unit, which is connected to the gas supply unit, the coolant supply unit and the first temperature sensor respectively and is configured to implement the temperature monitoring method according to the invention using a computer program product according to the invention. Attached Figure Description

[0018] The invention will now be described in more detail with reference to the accompanying drawings, which will provide a better understanding of its principles, features, and advantages. The drawings include:

[0019] Figure 1 A schematic connection block diagram of a fuel cell system according to an exemplary embodiment of the present invention is shown;

[0020] Figure 2 A schematic flowchart of a temperature monitoring method for a gas loop in a fuel cell system according to an exemplary embodiment of the present invention is shown. Detailed Implementation

[0021] To make the technical problems to be solved, the technical solutions, and the beneficial technical effects of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and several exemplary embodiments. It should be understood that the specific embodiments described herein are for illustrative purposes only and are not intended to limit the scope of protection of the present invention. For the sake of brevity, elements with the same reference numerals are indicated only once in the drawings.

[0022] In this specification, unless otherwise expressly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they may refer to a fixed connection, a detachable connection, or an integral connection; a mechanical connection or an electrical connection; a direct connection or an indirect connection via an intermediate component, or a connection within two components. Those skilled in the art will understand the meaning of these terms in this disclosure as appropriate.

[0023] It should be understood that the terms "first," "second," etc., used herein are for descriptive purposes only and should not be construed as indicating or implying relative importance, nor should they be construed as implicitly specifying the number of technical features indicated. Features specified as "first" or "second" may expressly or implicitly indicate that at least one of those features is included.

[0024] Furthermore, in describing representative embodiments, the specification may have presented methods and / or processes as a specific sequence of steps. However, the method or process should not be limited to the specific order of steps described herein, to the extent that it does not depend on such a specific order. As will be understood by those skilled in the art, other sequences of steps are also possible. Therefore, the specific order of steps set forth in the specification should not be construed as a limitation of the claims. Moreover, the claims concerning the method and / or process should not be limited to the steps performed in the written order, and those skilled in the art will readily understand that these orders can be varied and still remain within the spirit and scope of the embodiments of this application.

[0025] Figure 1 A schematic connection block diagram of a fuel cell system 100 according to an exemplary embodiment of the present invention is shown. Here, the fuel cell system 100 is used, for example, in a vehicle. Of course, other application areas that those skilled in the art will find meaningful are also possible.

[0026] like Figure 1 As shown, the fuel cell system 100 includes a fuel cell stack 10, which is composed of multiple fuel cell cells stacked on top of each other along the thickness direction. The fuel cell stack 10 has a cathode inlet manifold communicating with the cathode flow path of each fuel cell cell to supply cathode gas, such as air, to the cathode of the fuel cell cell, and has an anode inlet manifold communicating with the anode flow path of each fuel cell cell to supply anode gas, i.e., hydrogen, to the anode of the fuel cell cell.

[0027] like Figure 1As shown, the fuel cell system 100 includes a gas circuit 20 connected to the intake manifold of the fuel cell stack 10. At least a gas supply unit 21 and a heat exchange unit 22 are arranged in the gas circuit 20. The gas supply unit 21 is configured to increase the pressure and flow rate of the reactant gas and deliver the reactant gas to the corresponding intake manifold, during which the kinetic energy of the reactant gas increases and its temperature rises accordingly. The heat exchange unit 22 is configured to absorb heat from the reactant gas through a refrigerant and lower its temperature. The heat exchange unit 22 is particularly configured as an intercooler having a coolant chamber and a gas chamber, through which a coolant, such as water, flows, and through which the reactant gas flows. The coolant chamber and the gas chamber are separated by a thermally conductive partition wall. Preferably, the gas circuit 20 can be configured as a cathode gas circuit connected to the cathode intake manifold of the fuel cell stack 10. In this case, the gas supply unit 21 is configured with an air compressor, and the reactant gas is air. Furthermore, the gas circuit 20 may additionally include an air filter 23 to prevent impurities such as moisture or dust from entering the fuel cell stack 10. Alternatively, the gas circuit 20 may be configured as an anode gas circuit connected to the anode intake manifold of the fuel cell stack 10, wherein the gas supply unit 21 is equipped with a hydrogen circulation pump and the reactant gas is hydrogen. Here, for the sake of brevity, Figure 1 Only one gas loop 20 is shown. Here, the gas temperature of the reaction gas flowing out of the heat exchange unit 22 corresponds to or is substantially equal to the inlet temperature of the reaction gas when it reaches the corresponding inlet manifold. This inlet temperature affects the operating performance of the fuel cell stack 10. In particular, when the inlet temperature is too high, it will significantly reduce the water content of the membrane module of the fuel cell, thereby causing membrane dry failure and adversely affecting the service life of the fuel cell stack 10.

[0028] like Figure 1 As shown, the fuel cell system 100 includes a coolant circuit 30 connected to a heat exchange unit 22. A coolant supply unit 31 is arranged in the coolant circuit 30, specifically equipped with a water pump to deliver water, as coolant, to the coolant chamber of the heat exchange unit 22. Other coolants deemed meaningful by those skilled in the art, such as air or ethylene glycol solution, may also be considered. Furthermore, a first temperature sensor 32 is arranged in the coolant circuit 30, located between the coolant supply unit 31 and the heat exchange unit 22, and configured to detect the coolant temperature before reaching the heat exchange unit 22.

[0029] For example, such as Figure 1As shown, an intake valve 24 is additionally arranged in the gas circuit 20. This intake valve is configured to control the inflow of reactant gas into the fuel cell stack 10 via an intake line. Here, the intake valve 24 can be configured as a proportional valve, allowing precise control of the reactant gas supply flow rate by adjusting the valve opening. Alternatively, the intake valve 24 can be configured as a shut-off valve, opening during normal operation of the fuel cell system 100 and closing in abnormal conditions. The intake valve 24 can reduce or even completely stop the reactant gas supply when overheating is detected.

[0030] For example, such as Figure 1 As shown, the fuel cell system 100 also includes a second temperature sensor 25, which may be located upstream of the gas supply unit 21 or outside the fuel cell system 100, for example, in a vehicle, and is configured to detect ambient temperature.

[0031] like Figure 1 As shown, the fuel cell system 100 includes a control unit 40, which is electrically or communicatively connected to a gas supply unit 21, a coolant supply unit 31, and a first temperature sensor 32, and is configured to implement the temperature monitoring method according to the invention using a computer program product according to the invention. The computer program product includes a computer program that, when executed by one or more processors, enables the processors to execute the temperature monitoring method according to the invention. Referring below... Figure 2 The temperature monitoring method according to the present invention is explained in detail.

[0032] Figure 2 A schematic flowchart illustrating a temperature monitoring method for a gas circuit 20 of a fuel cell system 100 according to an exemplary embodiment of the present invention is shown. Here, the temperature monitoring method according to the present invention is explained using a cathode gas circuit as an example.

[0033] like Figure 2 As shown, the temperature monitoring method includes at least the following steps:

[0034] S1: Obtain the first operating parameters of the gas supply unit 21 in the gas circuit 20, especially the air compressor, and calculate the first gas temperature and gas flow rate of the reaction gas supplied by the gas supply unit 21, i.e., the compressed air, based on the first operating parameters. The reaction gas is further supplied to the heat exchange unit 22 in the gas circuit 20. For example, the first operating parameters may include at least the initial gas temperature of the reaction gas before entering the gas supply unit 21, the first power of the gas supply unit 21, and the first rotation speed of the gas supply unit 21. The first rotation speed of the gas supply unit 21 is proportional to the gas volume flow rate. The mass of gas compressed per unit time can be estimated based on the first rotation speed, thereby calculating the gas flow rate. The temperature difference achieved during the compression process can be calculated using the first power of the gas supply unit 21 in combination with the gas flow rate. The sum of the temperature difference and the initial gas temperature of the reaction gas is the outlet temperature of the gas supply unit 21, i.e., the first gas temperature of the compressed reaction gas. The first gas temperature is significantly higher than the initial gas temperature. The above calculation process can be easily performed based on existing empirical formulas and / or calculation models.

[0035] S2: Obtain the second operating parameters of the coolant supply unit 31, especially the water pump, in the coolant circuit 30, and calculate the coolant flow rate of the coolant supplied by the coolant supply unit 31, i.e., the water, based on the second operating parameters. The coolant is also further supplied to the heat exchange unit 22, in which the coolant absorbs the heat of the reaction gas to reduce the gas temperature of the reaction gas. For example, the second operating parameters may include at least the second power and the second rotation speed of the coolant supply unit 31. The coolant flow rate can be calculated from the second power and the second rotation speed based on existing empirical formulas and / or calculation models.

[0036] S3: The coolant temperature is obtained by the first temperature sensor 32 before the coolant supplied by the coolant supply unit 31 reaches the heat exchange unit 22. The first temperature sensor may be arranged between the coolant supply unit 31 and the heat exchange unit 22.

[0037] S4: Based on the first gas temperature and gas flow rate calculated in step S1, the coolant flow rate calculated in step S2, and the coolant temperature obtained in step S3, the second gas temperature of the cooled reaction gas flowing out of the heat exchange unit 22 is calculated according to the principle of energy conservation. The reaction gas is supplied to the corresponding intake manifold of the fuel cell stack 10. The second gas temperature corresponds to the intake temperature when the reaction gas reaches the intake manifold. The above calculation process can be easily performed based on existing empirical formulas and / or calculation models.

[0038] Therefore, the temperature of the reactant gas can be monitored in real time using the fuel cell system 100 in a simple and cost-effective manner, without the need to install an additional temperature sensor specifically for the reactant gas in the gas loop 20. This allows for timely countermeasures when overheating is detected, thereby avoiding adverse effects of overheated reactant gas on the fuel cell stack 10 and improving the operating performance and service life of the fuel cell system 100.

[0039] For example, the initial gas temperature in the first operating parameter obtained in step S1 can be the ambient temperature, which corresponds to the initial gas temperature of the air before it enters the air compressor. The ambient temperature is detected by a second temperature sensor 25, which can be arranged outside the fuel cell system 100, for example, in a vehicle or on the encapsulation housing of the fuel cell system 100.

[0040] For example, the first operating parameters obtained in step S1 may also include the compression ratio and / or volumetric efficiency of the gas supply unit 21, particularly the air compressor, and / or the specific heat capacity of the reactant gas. This allows for a more accurate calculation of the first gas temperature and gas flow rate of the reactant gas. Of course, other operating parameters that are considered meaningful by those skilled in the art can also be considered, such as the heat dissipation coefficient. Furthermore, the second operating parameters obtained in step S2 may also include parameters such as the head of the coolant supply unit 31 and the pump efficiency.

[0041] For example, such as Figure 2 As shown, the temperature monitoring method further includes step S5: when the second gas temperature calculated in step S4 exceeds a preset temperature threshold, the control unit 40 issues a control command to reduce the valve opening of the intake valve 24 arranged in the gas circuit 20 or close the intake valve 24. The intake valve 24 can be configured as a proportional valve or a shut-off valve. Here, the temperature threshold is derived from experimental data and / or empirical data, for example, 100°C. Of course, other temperature values ​​that are considered meaningful by those skilled in the art can also be considered. This can reduce, or even urgently shut off, the inflow of reactant gas into the fuel cell stack 10 in the event of overheating of the reactant gas, thereby preventing damage to the fuel cell stack 10 caused by excessively hot reactant gas.

[0042] For example, the valve opening of the intake valve 24 is reduced or closed only when the second gas temperature calculated in step S4 continuously exceeds the temperature threshold for a preset time period. This provides redundancy for the control of the intake valve 24, avoiding frequent changes or closures of the intake valve 24 due to temperature fluctuations.

[0043] The foregoing description of the embodiments is limited to the framework of the examples given. Of course, the various features of the embodiments can be freely combined with each other without departing from the framework of the invention, as long as it is technically meaningful.

[0044] Other advantages and alternative embodiments of the present invention will be apparent to those skilled in the art. Therefore, the present invention is not, in its broader sense, limited to the specific details, representative structures, and exemplary embodiments shown and described. Rather, those skilled in the art can make various modifications and substitutions without departing from the basic spirit and scope of the invention.

Claims

1. A method for temperature monitoring of a gas circuit (20) in a fuel cell system (100), characterized in that, The temperature monitoring method includes at least the following steps: S1: Obtain the first operating parameters of the gas supply unit (21) in the gas circuit (20) and calculate the first gas temperature and gas flow rate of the reaction gas supplied by the gas supply unit (21) based on the first operating parameters. The reaction gas is supplied to the heat exchange unit (22) in the gas circuit (20). S2: Obtain the second operating parameters of the coolant supply unit (31) in the coolant circuit (30), calculate the coolant flow rate of the coolant supplied by the coolant supply unit (31) based on the second operating parameters, and the coolant is also supplied to the heat exchange unit (22); S3: The coolant temperature is obtained by the first temperature sensor (32) before the coolant reaches the heat exchange unit (22); S4: Calculate the second gas temperature of the reaction gas flowing out of the heat exchange unit (22) based on the first gas temperature, the gas flow rate, the coolant flow rate and the coolant temperature. The reaction gas is supplied to the fuel cell stack (10) of the fuel cell system (100) and the second gas temperature corresponds to the inlet temperature of the fuel cell stack (10).

2. The temperature monitoring method according to claim 1, characterized in that, The first operating parameters include at least the initial gas temperature of the reaction gas before it enters the gas supply unit (21), the first power of the gas supply unit (21), and the first rotational speed of the gas supply unit (21).

3. The temperature monitoring method according to claim 2, characterized in that, The initial gas temperature is the ambient temperature, which is detected by a second temperature sensor (25) located upstream of the gas supply unit (21) or outside the fuel cell system (100); and / or The first operating parameters also include the compression ratio and / or volumetric efficiency of the gas supply unit (21) and / or the specific heat capacity of the reaction gas.

4. The temperature monitoring method according to any one of claims 1 to 3, characterized in that, The second operating parameters include at least the second power of the coolant supply unit (31) and the second rotation speed of the coolant supply unit (31).

5. The temperature monitoring method according to any one of the preceding claims, characterized in that, The gas circuit (20) is a cathode gas circuit, the gas supply unit (21) is equipped with an air compressor, and the reaction gas is air; or, the gas circuit (20) is an anode gas circuit, the gas supply unit (21) is equipped with a hydrogen circulation pump, and the reaction gas is hydrogen; and / or The coolant supply unit (31) is equipped with a water pump and the coolant is water.

6. The temperature monitoring method according to any one of the preceding claims, characterized in that, The temperature monitoring method additionally includes step S5: when the temperature of the second gas exceeds a preset temperature threshold, reducing the valve opening of the inlet valve (24) arranged in the gas circuit (20) or closing the inlet valve (24).

7. The temperature monitoring method according to claim 6, characterized in that, When the temperature of the second gas continuously exceeds the temperature threshold for a preset time period, the valve opening is reduced or the inlet valve (24) is closed; and / or The temperature threshold is determined based on experimental data and / or empirical data; and / or The intake valve (24) is constructed as a proportional valve or a shut-off valve.

8. A computer program product comprising a computer program, characterized in that, When the computer program is executed by one or more processors, the processors are capable of performing the temperature monitoring method according to any one of claims 1-7.

9. A fuel cell system (100), characterized in that, The fuel cell system (100) includes at least: - Fuel cell stack (10); - Gas circuit (20), the gas circuit (20) is connected to the intake manifold of the fuel cell stack (10), wherein at least a gas supply unit (21) and a heat exchange unit (22) are arranged in the gas circuit (20); - A coolant circuit (30) connected to the heat exchange unit (22), wherein at least a coolant supply unit (31) and a first temperature sensor (32) are arranged in the coolant circuit (30); and - A control unit (40), which is connected to the gas supply unit (21), the coolant supply unit (31) and the first temperature sensor (32) respectively and is configured to implement the temperature monitoring method according to any one of claims 1 to 7 using the computer program product according to claim 8.

10. The fuel cell system (100) according to claim 9, characterized in that, The gas circuit (20) is configured as a cathode gas circuit, which is connected to the cathode intake manifold of the fuel cell stack (10), wherein the gas supply unit (21) is configured with an air compressor; or, the gas circuit (20) is configured as an anode gas circuit, which is connected to the anode intake manifold of the fuel cell stack (10), wherein the gas supply unit (21) is configured with a hydrogen circulation pump; and / or The coolant supply unit (31) is equipped with a water pump; and / or The heat exchange unit (22) is configured as an intercooler having a coolant chamber and a gas chamber; and / or An air filter (23) and / or an intake valve (24) are additionally arranged in the gas circuit (20); and / or The fuel cell system (100) includes a second temperature sensor (25), which is arranged upstream of the gas supply unit (21) or outside the fuel cell system (100).

Images