Control method and device of hydrogen circulating pump, fuel cell system and vehicle

Abstract

The invention provides a control method and device for a hydrogen circulating pump, a fuel cell system and a vehicle. The control method for the hydrogen circulating pump comprises the steps that the environment temperature of the hydrogen circulating pump is obtained, and when the environment temperature is lower than a preset temperature threshold value, the hydrogen circulating pump is started; acquiring the lowest rotating speed when the running current of the hydrogen circulating pump at each current density point is in a constant state, controlling the hydrogen circulating pump to run at the corresponding lowest rotating speed, acquiring the lowest opening frequency of the nitrogen removal valve at each current density point when the electric pile of the fuel cell system is not only low, and controlling the lowest opening frequency of the nitrogen removal valve in the running process of the fuel cell system. And when the environment temperature is lower than the preset temperature threshold value, the hydrogen circulating pump is controlled to operate according to the corresponding lowest rotating speed under each electric density point, and meanwhile, the nitrogen discharging valve is controlled to work according to the lowest opening frequency. According to the invention, the requirements of low power consumption, low hydrogen consumption and low system complexity of the fuel cell system can be met, and the working stability of the fuel cell system can be improved.

Description

Technical Field

[0001] The present invention relates to the field of fuel cell technology, and in particular to a control method for a hydrogen circulation pump. The present invention also relates to a control device for a hydrogen circulation pump based on the above method, a fuel cell system provided with the control device, and a vehicle provided with the fuel cell system. Background Art

[0002] In the prior art, the anode loop of the fuel cell system is used to supply hydrogen, and in order to ensure the operating life of the fuel-electric system, the hydrogen circulation pump must be kept in working condition. However, when the ambient temperature drops to the freezing temperature, the hydrogen circulation pump operates at low temperatures, and water is easily accumulated and frozen at the bottom of the pump. Since there is still no effective method to control the drainage of the hydrogen circulation pump in a low temperature environment, once ice forms, it will not only cause the working performance of the hydrogen circulation pump to decline, but in severe cases it may even cause the stack in the system to malfunction and shut down, which is not conducive to improving the working stability of the fuel cell system. Summary of the invention

[0003] In view of this, the present invention aims to provide a control method for a hydrogen circulation pump, so as to improve the working stability of a fuel cell system.

[0004] To achieve the above object, the technical solution of the present invention is achieved as follows:

[0005] A method for controlling a hydrogen circulation pump, comprising:

[0006] Obtain the ambient temperature at the hydrogen circulation pump;

[0007] When the ambient temperature is lower than a preset temperature threshold, the hydrogen circulation pump is controlled to operate, and the nitrogen exhaust valve connected to the hydrogen circulation pump is closed, and the minimum speed of the hydrogen circulation pump when the operating current is in a constant state at each electrical density point is obtained;

[0008] At each electrical density point, the nitrogen exhaust valve is opened, the hydrogen circulation pump is controlled to operate at the corresponding minimum speed, and the minimum opening frequency of the nitrogen exhaust valve when the fuel cell system stack is not low at each electrical density point is obtained;

[0009] During the operation of the fuel cell system, when the ambient temperature is lower than the preset temperature threshold, at each electrical density point, the hydrogen circulation pump is controlled to operate at the corresponding minimum speed, and the nitrogen exhaust valve is simultaneously controlled to operate at the minimum opening frequency.

[0010] Furthermore, the step of obtaining the minimum speed of the hydrogen circulation pump when the operating current is in a constant state at each electrical density point includes:

[0011] At each electrical density point, the speed of the hydrogen circulation pump is controlled to gradually increase according to a preset speed gradient, and the hydrogen circulation pump is controlled to run for a first preset time at each speed, and the operating current of the hydrogen circulation pump within the first preset time is synchronously recorded;

[0012] Among the various rotation speeds at which the operating current of the hydrogen circulation pump is in a constant state within the first preset time, the minimum rotation speed is recorded as the lowest rotation speed of the hydrogen circulation pump at the current density point.

[0013] Furthermore, the obtaining of the minimum opening frequency of the nitrogen exhaust valve when the fuel cell system stack is not low at each electrical density point includes:

[0014] At each electric density point, the opening frequency of the nitrogen exhaust valve is controlled to be gradually reduced according to a preset frequency gradient within a second preset time, and whether a single low occurs in the fuel cell stack of the fuel cell system is simultaneously recorded;

[0015] Among the opening frequencies at which the stack of the fuel cell system does not experience a single low, the minimum opening frequency is recorded as the lowest opening frequency of the nitrogen exhaust valve at the electrical density point.

[0016] Furthermore, the preset temperature threshold is 0°C.

[0017] Compared with the prior art, the present invention has the following advantages:

[0018] The control method of the hydrogen circulation pump described in the present invention obtains the minimum speed when the operating current of the hydrogen circulation pump is in a constant state at each electrical density point, and controls the hydrogen circulation pump to operate at the corresponding minimum speed, obtains the minimum opening frequency of the nitrogen exhaust valve when the fuel cell system stack is not low at each electrical density point, and during the operation of the fuel cell system, controls the hydrogen circulation pump to operate at the corresponding minimum speed at each electrical density point at low temperature, and simultaneously controls the nitrogen exhaust valve to operate at the minimum opening frequency.

[0019] Therefore, by controlling the speed and drainage cycle of the hydrogen circulation pump at low temperatures, on the one hand, the hydrogen circulation pump can be operated at the lowest speed obtained to avoid or reduce water accumulation and icing in the hydrogen circulation pump, and the power consumption of the fuel cell system can be lower. On the other hand, the nitrogen exhaust valve can be operated at the lowest opening frequency obtained, so that the fuel cell system will not have a single low situation, and the hydrogen consumption of the system can also be lower. Therefore, when the fuel cell system is in a low temperature environment, the control method of the present invention can avoid or reduce water accumulation in the hydrogen circulation pump and reduce the risk of icing in the hydrogen circulation pump under the conditions of low system power consumption and low hydrogen consumption, so as to improve the stability of the operation of the fuel cell system and help improve the use quality of the fuel cell system.

[0020] Another object of the present invention is to provide a control device for a hydrogen circulation pump, comprising an ambient temperature detection module, a first acquisition module, a second acquisition module and a control module;

[0021] The ambient temperature detection module is used to obtain the ambient temperature of the hydrogen circulation pump;

[0022] The first acquisition module is used to acquire the minimum speed of the hydrogen circulation pump when the operating current is in a constant state at each electrical density point when the ambient temperature is lower than a preset temperature threshold, the hydrogen circulation pump is running, and the nitrogen exhaust valve connected to the hydrogen circulation pump is closed;

[0023] The second acquisition module is used to obtain the minimum opening frequency of the nitrogen exhaust valve when the fuel cell system stack is not low at each electrical density point when the nitrogen exhaust valve is opened and the hydrogen circulation pump is controlled to operate at the corresponding minimum speed;

[0024] The control module is used to control the hydrogen circulation pump to operate at the corresponding minimum speed and control the nitrogen exhaust valve to operate at the minimum opening frequency at each electrical density point during the operation of the fuel cell system when the ambient temperature is lower than the preset temperature threshold.

[0025] Furthermore, the preset temperature threshold is 0°C.

[0026] The control device of the hydrogen circulation pump described in the present invention can control the rotation speed and drainage cycle of the hydrogen circulation pump at low temperature through the settings of the above-mentioned modules. On the one hand, this can avoid water accumulation and ice formation in the hydrogen circulation pump, and also prevent the system from experiencing a single low situation, which is beneficial to improving the stability of the operation of the fuel cell system. On the other hand, the hydrogen circulation pump can be operated at the lowest speed, so that the power consumption of the fuel cell system is lower, and the nitrogen exhaust valve can be operated at the lowest opening frequency, so that the system hydrogen consumption is lower, which also helps to improve the use quality of the fuel cell system.

[0027] The present invention also proposes a fuel cell system, which includes a fuel cell stack, a hydrogen circulation pump connected to the fuel cell stack in a loop, and a nitrogen exhaust valve connected to the hydrogen circulation pump, and also includes a control device for the hydrogen circulation pump as described above.

[0028] In addition, the present invention also provides a vehicle, in which the fuel cell system as described above is provided.

[0029] Finally, the present invention further proposes a computer-readable storage medium, wherein the computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the control method of the hydrogen circulation pump as described above is implemented.

[0030] The fuel cell system, the vehicle having the system, and the computer-readable storage medium described in the present invention have the same beneficial effects as the above-mentioned hydrogen circulation pump control method or drainage control device relative to the prior art, and will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The accompanying drawings constituting a part of the present invention are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the accompanying drawings:

[0032] Figure 1 A schematic diagram of an anode loop in a fuel cell system according to an embodiment of the present invention;

[0033] Figure 2 This is a flow chart of a method for controlling a hydrogen circulation pump according to an embodiment of the present invention;

[0034] Figure 3 This is a flow chart for obtaining the minimum speed of the hydrogen circulation pump at each electrical density point according to an embodiment of the present invention;

[0035] Figure 4 This is a flow chart for obtaining the minimum opening frequency of the nitrogen exhaust valve at each electrical density point according to an embodiment of the present invention;

[0036] Figure 5 Schematic diagram of the structure of the control device of the hydrogen circulation pump according to an embodiment of the present invention.

[0037] Description of reference numerals:

[0038] 1. Fuel cell; 2. Hydrogen injection valve; 3. Hydrogen circulation pump; 4. Nitrogen exhaust valve; 5. Gas-liquid separator; 6. Drain valve; 7. Pressure sensor;

[0039] 100, control module; 200, temperature detection module; 300, first acquisition module; 400, second acquisition module. DETAILED DESCRIPTION

[0040] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments may be combined with each other.

[0041] In the description of the present invention, it should be noted that if there are terms indicating orientation or positional relationship such as "upper", "lower", "inner", "outer", etc., they are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, if there are terms such as "first", "second", etc., they are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0042] In addition, in the description of the present invention, unless otherwise clearly defined, the terms "installed", "connected", "connection" and "connector" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood in combination with specific circumstances.

[0043] The present invention will be described in detail below with reference to the accompanying drawings and in conjunction with embodiments.

[0044] Embodiment 1

[0045] The present embodiment relates to a method for controlling a hydrogen circulation pump, which involves controlling the rotational speed of the hydrogen circulation pump in a fuel cell system and the working cycle of a nitrogen exhaust valve on the hydrogen circulation pump under low temperature (ambient temperature below 0°C). The method of the present embodiment is conducive to improving the stability of the operation of the fuel cell system, and also helps to improve the use quality of the fuel cell system.

[0046] In this embodiment, since the hydrogen circulation pump 3 is a part of the anode loop of the fuel cell system, the anode loop of the fuel cell system is briefly introduced here.

[0047] Combination Figure 1 As shown in the figure, in the anode loop of the fuel cell system, there are mainly provided a hydrogen injection valve 2, a gas-liquid separator 5 and a hydrogen circulation pump 2 connected to the fuel cell stack 1, and a drain valve 6 connected to the gas-liquid separator 5, a nitrogen discharge valve 4 connected to the hydrogen circulation pump 3, and a pressure sensor 7 located at the anode inlet and anode outlet of the fuel cell stack 1 respectively.

[0048] The hydrogen injection valve 2 is used to control the amount of hydrogen supplied to the stack 1. The gas-liquid separator 5 is used to separate the gas and liquid and separate the water from the circulating gas flow. The separated water can be discharged by the drain valve 6. The hydrogen circulation pump 3 is used for the hydrogen in the circulation loop, and the nitrogen exhaust valve 4 is used for nitrogen exhaust and water exhaust. The pressure sensor 7 located at the anode inlet and outlet is used to detect the gas flow pressure at the anode inlet and outlet for system control.

[0049] In the above-mentioned anode loop, water will also accumulate in the hydrogen circulation pump 3 and needs to be drained through the nitrogen exhaust valve 4. Therefore, when the ambient temperature of the hydrogen circulation pump 3 drops to the freezing temperature, the hydrogen circulation pump 3 operates at a low temperature, and the accumulated water at the bottom of the pump is prone to freeze. Once frozen, not only will the working performance of the hydrogen circulation pump 3 be reduced, but in severe cases, it will cause the fuel cell stack 1 in the fuel cell system to malfunction and shut down.

[0050] The control method of the hydrogen circulation pump of this embodiment is as described above, which is designed to solve the problem of water accumulation and freezing when the hydrogen circulation pump 3 is running at low temperature, and is based on the above introduction to the anode circuit in the fuel cell system, and is also combined with Figure 2 As shown in , overall, the control method of the hydrogen circulation pump of this embodiment includes:

[0051] The first step is to obtain the ambient temperature of the hydrogen circulation pump 3.

[0052] In this step, the ambient temperature of the hydrogen circulation pump 3 can be obtained by, for example, detecting the ambient temperature through a temperature sensor disposed in the environment where the hydrogen circulation pump 3 is located.

[0053] In the second step, when the ambient temperature is lower than the preset temperature threshold, the hydrogen circulation pump 3 is controlled to operate, and the nitrogen exhaust valve 4 connected to the hydrogen circulation pump 3 is closed to obtain the minimum speed when the operating current of the hydrogen circulation pump 3 is in a constant state at each electrical density point.

[0054] Among them, in this step, preferably, the above-mentioned preset temperature threshold value can be, for example, 0°C. When the temperature of the environment in which the hydrogen circulation pump 3 is located is lower than 0°C, the accumulated water at the bottom of the hydrogen circulation pump 3 will freeze and affect the normal operation of the hydrogen circulation pump 3. Therefore, it is necessary to drain the hydrogen circulation pump 3 through the nitrogen exhaust valve 4 when the ambient temperature is lower than 0°C.

[0055] In addition, in this step, as a preferred implementation form, combined with Figure 3 As shown, the minimum speed when the operating current of the hydrogen circulation pump 3 is in a constant state at each electric density point can specifically include:

[0056] Step S11, at each electrical density point, control the speed of the hydrogen circulation pump 3 to gradually increase according to a preset speed gradient, and control the hydrogen circulation pump 3 to run for a first preset time at each speed, and synchronously record the operating current of the hydrogen circulation pump 3 within the first preset time.

[0057] Step S12, among the various rotation speeds at which the operating current of the hydrogen circulation pump 3 is in a constant state within the first preset time, the minimum rotation speed is recorded as the lowest rotation speed of the hydrogen circulation pump 3 at the current density point.

[0058] In the above step S11, at each electrical density point, the initial speed of the hydrogen circulation pump 3 can be 0rpm, or other values ​​determined based on experience, such as 500rpm, 1000rpm or 1200rpm, etc. The above preset speed gradient can also be set according to the specifications and performance of the hydrogen circulation pump 3, and it can be, for example, 100rpm, 150rpm, 200rpm, 300rpm or 500rpm, etc. The above first preset time can generally be set to 10min, and the speed upper limit of the hydrogen circulation pump 3 can adopt the rated speed of the motor therein, or it can also be selected based on experience. The value lower than the rated speed is used as the speed upper limit of the hydrogen circulation pump 3 at each electrical density point.

[0059] In the above step S12, the operating current of the hydrogen circulation pump 3 is in a constant state, that is, within the first preset time corresponding to the rotation speed, the operating current of the hydrogen circulation pump 3 is a constant value and does not fluctuate. At this time, the operating current of the hydrogen circulation pump 3 does not fluctuate, which means that no water is generated at the bottom of the hydrogen circulation pump 3, or no water that can affect the operation of the hydrogen circulation pump 3 is generated. The minimum rotation speed among the rotation speeds at which the operating current is a constant value is recorded as the minimum rotation speed. On the one hand, it means that when the rotation speed of the hydrogen circulation pump 3 reaches this rotation speed, no water will be generated at the bottom of the hydrogen circulation pump 3, or no water that can affect the operation of the hydrogen circulation pump 3 will be generated, that is, there is only a small amount of water. On the other hand, the use of the minimum rotation speed can obviously minimize the energy consumption of the hydrogen circulation pump 3 under the premise of meeting the work needs.

[0060] It should be noted that in the above steps S11 and S12, at each electrical density point, the initial speed of the hydrogen circulation pump 3, the preset speed gradient, and the corresponding operating current at each speed can be shown in, for example, Table 1 below.

[0061] Among them, Table 1 specifically uses 0.1 electric density, the initial speed of the hydrogen circulation pump 3 is 500rpm, and the preset speed gradient is 100rpm as an example for exemplary description. Of course, in specific implementation, the initial speed of the hydrogen circulation pump 3 and the preset speed gradient can use other preset values, and refer to Table 1 under 0.1 electric density, and then other electric density points, such as 0.2 electric density, 0.3 electric density, 0.4 electric density..., can be recorded in turn, and the operating current fluctuation corresponding to each speed.

[0062] Table 1. Statistics of current fluctuations of hydrogen circulation pump at various speeds

[0063] Electric density point / (A / cm2) 0.1 0.1 0.1 … Hydrogen pump speed / rpm 500 600 700 … Nitrogen exhaust valve closure closure closure Does the hydrogen pump operating current fluctuate? yes yes no

[0064] The third step is to open the nitrogen exhaust valve 4 at each electrical density point, control the hydrogen circulation pump 3 to operate at the corresponding minimum speed, and obtain the minimum opening frequency of the nitrogen exhaust valve 4 when the fuel cell stack 1 in the fuel cell system is not low at each electrical density point.

[0065] In this step, as a preferred implementation form, combined with Figure 4 As shown, under the above-mentioned acquisition of each electric density point, the minimum opening frequency of the nitrogen exhaust valve 4 when the fuel cell stack 1 in the fuel cell system is not only low, but also may specifically include:

[0066] Step S21, at each electric density point, controlling the opening frequency of the nitrogen exhaust valve 4 to gradually decrease according to a preset frequency gradient within a second preset time, and synchronously recording whether a single low occurs in the fuel cell stack 1 in the fuel cell system;

[0067] Step S22: Among the opening frequencies at which the fuel cell stack 1 in the fuel cell system does not experience a single low, the minimum opening frequency is recorded as the lowest opening frequency of the nitrogen exhaust valve 4 at the electrical density point.

[0068] Among them, the stack 1 in the above-mentioned fuel cell system has a single low, that is, the voltage of an individual cell in the stack 1 is significantly lower than the average voltage of the stack 1, which can be obtained through the battery manager. The above-mentioned second preset time can also be, for example, 10 minutes. The initial value of the opening frequency of the above-mentioned nitrogen exhaust valve 4 can be, for example, on 1s and off 1s, and the above-mentioned preset frequency gradient can be, for example, off+1s, that is, the opening frequency of the nitrogen exhaust valve 4 can be on 1s and off 1s, on 1s and off 2s, on 1s and off 2s...gradually decreasing.

[0069] Of course, in specific implementation, the second preset time and even the first preset time may adopt other values. Meanwhile, the initial value of the opening frequency of the nitrogen exhaust valve 4 and the preset frequency gradient may also adopt other frequency values.

[0070] It should be noted that in step S22, among the opening frequencies of the nitrogen exhaust valves 4 at which the stack 1 in the fuel cell system does not experience a single low, the minimum opening frequency is recorded as the minimum opening frequency of the nitrogen exhaust valve 4 at the electric density point. In this way, on the one hand, the stack 1 of the fuel cell system can prevent a single low from occurring, and the normal operation of the fuel cell system can be ensured. On the other hand, the minimum opening frequency of the nitrogen exhaust valve 4 can also reduce the opening time of the nitrogen exhaust valve 4, thereby ensuring that the amount of hydrogen lost through the nitrogen exhaust valve 4 is minimized while achieving nitrogen and water discharge, so as to reduce the hydrogen consumption of the system.

[0071] In addition, similar to the above reference table 1, in the above steps S21 and S22, at each electrical density point, the initial frequency of the nitrogen exhaust valve 4, the preset frequency gradient, and the single low condition of the fuel cell stack 1 corresponding to each frequency can be shown in the following table 2, for example.

[0072] Among them, Table 2 specifically uses 0.1 electric density, the initial opening frequency of the nitrogen exhaust valve 3 is 1s off 1s, and the preset frequency gradient is off + 1s as an example for exemplary description. Of course, in specific implementation, the initial opening frequency of the nitrogen exhaust valve 43 and the preset frequency gradient can use other preset values, and refer to Table 2 under 0.1 electric density, and then other electric density points can be recorded in sequence, such as 0.2 electric density, 0.3 electric density, 0.4 electric density..., and the corresponding single low situation of the battery stack 1 under each opening frequency of the nitrogen exhaust valve 4.

[0073] Table 2. Statistics of low battery stack conditions at various start-up frequencies

[0074] Electric density / (A / cm2) 0.1 0.1 0.1 … Hydrogen pump minimum speed / rpm 700 700 700 … Nitrogen exhaust valve opening frequency On 1s, Off 1s On for 1s, Off for 2s On for 1s, Off for 3s … Is the battery stack single low? Single Low Single Low Not only low

[0075] The fourth step is that during the operation of the fuel cell system, when the ambient temperature at the hydrogen circulation pump 3 is lower than the preset temperature threshold, at each electrical density point, the hydrogen circulation pump 3 is controlled to operate at the corresponding minimum speed, and at the same time, the nitrogen exhaust valve 4 connected to the hydrogen circulation pump 3 is controlled to operate at the minimum opening frequency.

[0076] In this step, according to the above steps, especially the minimum rotation speed of the hydrogen circulation pump 3 at each electrical density point obtained in the second step, and the minimum opening frequency of the nitrogen exhaust valve 4 at each electrical density point, during the operation of the fuel cell system, if the ambient temperature at the hydrogen circulation pump 3 is lower than 0°C, that is, when the hydrogen circulation pump 3 is in a low temperature environment, the hydrogen circulation pump 3 can be controlled to operate at the corresponding minimum rotation speed based on the current electrical density of the fuel cell system, and at the same time, the nitrogen exhaust valve 4 connected to the hydrogen circulation pump 3 can be controlled to operate at the minimum opening frequency.

[0077] In this way, when the fuel cell system is in a low-temperature environment, the control method of this embodiment controls the rotation speed and drainage cycle of the hydrogen circulation pump 3. On the one hand, the hydrogen circulation pump 3 can be used to work at the lowest rotation speed obtained to avoid or reduce water accumulation and icing in the hydrogen circulation pump 3, and the power consumption of the fuel cell system is also lower. On the other hand, the nitrogen exhaust valve 4 can be used to work at the lowest opening frequency obtained, so that the fuel cell system will not have a single low situation and the hydrogen consumption of the system can be lower.

[0078] Therefore, the control method of this embodiment can avoid or reduce water accumulation in the hydrogen circulation pump 3 when the fuel cell system is in a low-temperature environment and under the conditions of low system power consumption and low hydrogen consumption, and can reduce the risk of freezing of the hydrogen circulation pump 3, thereby helping to improve the stability of the operation of the fuel cell system and helping to improve the use quality of the fuel cell system.

[0079] Embodiment 2

[0080] This embodiment relates to a control device for a hydrogen circulation pump. The control device is based on the control method for a hydrogen circulation pump in the first embodiment and is combined with Figure 5 As shown in , in terms of overall structure, the control device includes a control module 100 , and an ambient temperature detection module 200 , a first acquisition module 300 and a second acquisition module 400 connected to the control module 100 .

[0081] Among them, the above-mentioned ambient temperature detection module 200 is used to obtain the ambient temperature at the hydrogen circulation pump 3. The above-mentioned first acquisition module 300 is used to obtain the minimum speed when the operating current of the hydrogen circulation pump 3 is in a constant state at each electrical density point when the ambient temperature is lower than the preset temperature threshold, the hydrogen circulation pump 3 is running, and the nitrogen exhaust valve 4 connected to the hydrogen circulation pump 3 is closed. The above-mentioned second acquisition module 400 is used to obtain the minimum opening frequency of the nitrogen exhaust valve 4 when the stack 1 of the fuel cell system is not low at each electrical density point when the nitrogen exhaust valve 4 is opened and the hydrogen circulation pump 3 is controlled to run at the corresponding minimum speed at each electrical density point;

[0082] The control module 100 is used to control the hydrogen circulation pump 3 to operate at the corresponding minimum speed and the nitrogen exhaust valve 4 to operate at the minimum opening frequency at each electrical density point during the operation of the fuel cell system when the ambient temperature is lower than the preset temperature threshold.

[0083] Specifically, the preset temperature threshold value may be, for example, 0° C. as in the first embodiment. In addition, in the specific implementation, the ambient temperature detection module 200 may be a temperature sensor disposed in the environment of the hydrogen circulation pump 3 as mentioned in the first embodiment, and the first acquisition module 300, the second acquisition module 400 and the control module 100 may be existing related module products capable of data input, output, storage and processing.

[0084] The control device of the hydrogen circulation pump of this embodiment and its specific control method during operation can refer to the description in the first embodiment.

[0085] Moreover, the control device of this embodiment can control the speed and drainage cycle of the hydrogen circulation pump 3 at low temperature through the setting of the above modules. On the one hand, it can avoid or reduce the accumulation of water and ice in the hydrogen circulation pump 3, and also prevent the fuel cell system from being low, which is conducive to improving the stability of the fuel cell system. On the other hand, it can also use the hydrogen circulation pump 3 to operate at the lowest speed, so that the power consumption of the fuel cell system is low, and use the nitrogen exhaust valve 4 to operate at the lowest opening frequency, so that the system hydrogen consumption is low, which helps to improve the use quality of the fuel cell system.

[0086] Embodiment 3

[0087] This embodiment relates to a fuel cell system, including a fuel cell stack 1, a hydrogen circulation pump 3 connected to the fuel cell stack 1 to form a loop, and a nitrogen exhaust valve 4 connected to the hydrogen circulation pump 3, and also includes the control device of the hydrogen circulation pump in Example 2.

[0088] Among them, the hydrogen circulation pump 3 connected to the fuel cell stack 1 in a loop, the nitrogen exhaust valve 4 connected to the hydrogen circulation pump 3, and the control device of the above-mentioned hydrogen circulation pump in this embodiment can all refer to the relevant descriptions in Example 1 and Example 2.

[0089] In addition, the present embodiment also relates to a vehicle, in which the above-mentioned fuel cell system is provided.

[0090] The fuel cell system of this embodiment, and the vehicle equipped with the system, by providing the control device of the second embodiment, is conducive to improving the stability of the operation of the fuel cell system, and also helps to improve the use quality of the fuel cell system, and has good practicality.

[0091] The above are only preferred embodiments of the present invention and are 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 in the protection scope of the present invention.

Claims

1. A method for controlling a hydrogen circulation pump, characterized in that: include: Obtaining the ambient temperature at the hydrogen circulation pump (3); When the ambient temperature is lower than a preset temperature threshold, the hydrogen circulation pump (3) is controlled to operate, and a nitrogen exhaust valve (4) connected to the hydrogen circulation pump (3) is closed, and the lowest speed when the operating current of the hydrogen circulation pump (3) is in a constant state at each electrical density point is obtained; At each electrical density point, the nitrogen exhaust valve (4) is opened, the hydrogen circulation pump (3) is controlled to operate at the corresponding minimum speed, and the minimum opening frequency of the nitrogen exhaust valve (4) when the fuel cell stack (1) in the fuel cell system is not low at each electrical density point is obtained; During operation of the fuel cell system, when the ambient temperature is lower than the preset temperature threshold, at each electrical density point, the hydrogen circulation pump (3) is controlled to operate at the corresponding minimum rotation speed, and the nitrogen exhaust valve (4) is simultaneously controlled to operate at the minimum opening frequency.

2. The control method of the hydrogen circulation pump according to claim 1, characterized in that: The step of obtaining the minimum rotation speed of the hydrogen circulation pump (3) when the operating current is in a constant state at each electric density point includes: At each electrical density point, the speed of the hydrogen circulation pump (3) is controlled to gradually increase according to a preset speed gradient, and the hydrogen circulation pump (3) is controlled to run for a first preset time at each speed, and the operating current of the hydrogen circulation pump (3) during the first preset time is synchronously recorded; Among the various rotation speeds at which the operating current of the hydrogen circulation pump (3) is in a constant state within the first preset time, the minimum rotation speed is recorded as the lowest rotation speed of the hydrogen circulation pump (3) at this current density point.

3. The control method of the hydrogen circulation pump according to claim 1, characterized in that: The step of obtaining the minimum opening frequency of the nitrogen exhaust valve (4) when the fuel cell stack (1) in the fuel cell system is not low at each electrical density point includes: At each electric density point, the opening frequency of the nitrogen exhaust valve (4) is controlled to gradually decrease according to a preset frequency gradient within a second preset time, and whether a single low occurs in the fuel cell stack (1) in the fuel cell system is simultaneously recorded; Among the various opening frequencies at which the fuel cell stack (1) in the fuel cell system does not experience a single low, the minimum opening frequency is recorded as the lowest opening frequency of the nitrogen exhaust valve (4) at the electrical density point.

4. The control method of the hydrogen circulation pump according to any one of claims 1 to 3, characterized in that: The preset temperature threshold is 0°C.

5. A control device for a hydrogen circulation pump, characterized in that: It comprises a control module (100), and an ambient temperature detection module (200), a first acquisition module (300), and a second acquisition module (400) connected to the control module (100); The ambient temperature detection module (200) is used to obtain the ambient temperature at the hydrogen circulation pump (3); The first acquisition module (300) is used to acquire the lowest speed when the operating current of the hydrogen circulation pump (3) is in a constant state at each electrical density point when the ambient temperature is lower than a preset temperature threshold, the hydrogen circulation pump (3) is running, and the nitrogen exhaust valve (4) connected to the hydrogen circulation pump (3) is closed; The second acquisition module (400) is used to, when the nitrogen exhaust valve (4) is opened at each electrical density point, and to control the hydrogen circulation pump (3) to operate at the corresponding minimum speed, obtain the minimum opening frequency of the nitrogen exhaust valve (4) when the fuel cell stack (1) of the fuel cell system is not low at each electrical density point; The control module (100) is used to control the hydrogen circulation pump (3) to operate at the corresponding minimum speed and to control the nitrogen exhaust valve (4) to operate at the minimum opening frequency at each electrical density point during operation of the fuel cell system when the ambient temperature is lower than the preset temperature threshold.

6. The control device for the hydrogen circulation pump according to claim 5, characterized in that: The preset temperature threshold is 0°C.

7. A fuel cell system, characterized in that: It comprises a fuel cell stack (1), a hydrogen circulation pump (3) connected to the fuel cell stack (1) to form a loop, and a nitrogen exhaust valve (4) connected to the hydrogen circulation pump (3), and also comprises a control device for the hydrogen circulation pump according to claim 5 or 6.

8. A vehicle, characterized in that: The vehicle is provided with the fuel cell system according to claim 7.

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