Impurity protection device and method for hydrogen supply system of fuel cell

Abstract

The application discloses a kind of fuel cell hydrogen supply system's impurity protection device and method, the first pressure sensor of the device is arranged at the first end of first filter screen, and the second pressure sensor is arranged at the second end of circulating device;Controller compares the pressure difference of first pressure value and second pressure value under first preset working condition, when the pressure difference is outside first preset range, it is judged that the first filter screen or second filter screen is blocked.The pressure difference of the embodiment of the application is outside first preset range, controller determines that the first filter screen or second filter screen is blocked, and the flow of hydrogen supply solenoid valve is adjusted to restore the power generation of fuel cell stack.It can filter impurities, and adjust in time when blocking occurs, so that fuel cell stack normally exports power.

Description

Technical Field

[0001] This invention relates to the field of impurity protection technology for fuel cell hydrogen supply systems, and particularly to an impurity protection device and method for fuel cell hydrogen supply systems. Background Technology

[0002] A fuel cell is a chemical device that directly converts the chemical energy of fuel into electrical energy; it is also known as an electrochemical generator. It is the fourth type of power generation technology after hydropower, thermal power generation, and nuclear power generation. Because fuel cells convert the Gibbs free energy portion of the fuel's chemical energy into electrical energy through an electrochemical reaction, they are not limited by the Carnot cycle effect, thus exhibiting high efficiency. Furthermore, fuel cells use fuel and oxygen as feedstock and have no mechanical transmission components, resulting in minimal emissions of harmful gases and a long service life. Therefore, from the perspective of energy conservation and environmental protection, fuel cells are the most promising power generation technology.

[0003] A standalone fuel cell stack cannot generate electricity. It must be integrated with a fuel (hydrogen) supply and circulation system, an oxidant supply system, a water / heat management system, and a control system to form a fuel cell power generation system in order to output power. Due to its unique composition and material properties, hydrogen fuel cells are highly sensitive to hydrogen impurities. These impurities include both gaseous and particulate matter. Once particulate matter enters the fuel cell stack, it can block the airflow channels, leading to increased pressure loss and permanent energy loss, thus affecting the parameter output and system efficiency of the entire fuel cell system.

[0004] Therefore, improving hydrogen purity, reducing impurities in the gas source, avoiding the generation of additional particulate impurities in the hydrogen supply system, and protecting against potential particulate impurities are among the important tasks of fuel cell hydrogen supply systems. Summary of the Invention

[0005] This invention provides an impurity protection device and method for a fuel cell hydrogen supply system, which can filter impurities and adjust in time when blockage occurs, thereby enabling the fuel cell stack to output power normally.

[0006] In a first aspect, embodiments of the present invention provide an impurity protection device for a fuel cell hydrogen supply system, wherein the fuel cell hydrogen supply system includes a hydrogen cylinder, a shut-off valve, a pressure reducing valve, a hydrogen supply solenoid valve, a circulation device, and a fuel cell stack connected in sequence via pipelines.

[0007] The impurity protection device includes: a first pressure sensor, a first filter, a second pressure sensor, a second filter, and a controller;

[0008] The first filter screen is disposed at the first end of the hydrogen supply solenoid valve, and the second filter screen is disposed at the first end of the fuel cell stack.

[0009] Hydrogen flows out of the hydrogen cylinder, passes through the shut-off valve and the pressure reducing valve, flows through the pipeline and the first filter screen, and then enters the hydrogen supply solenoid valve. After flowing out from the second end of the hydrogen supply solenoid valve, it flows through the pipeline and the circulation device and the second filter screen respectively before entering the fuel cell stack.

[0010] The first pressure sensor is disposed at the first end of the first filter screen, and the second pressure sensor is disposed at the second end of the circulation device; the first pressure sensor, the second pressure sensor, and the hydrogen supply solenoid valve are all electrically connected to the controller.

[0011] The controller is used to read the first pressure value measured by the first pressure sensor and the second pressure value measured by the second pressure sensor, and compare the pressure difference between the first pressure value and the second pressure value under the first preset operating conditions. If the pressure difference is outside the first preset range, it is determined that the first filter or the second filter is blocked. The controller is also used to adjust the flow rate of the hydrogen supply solenoid valve to restore the power generation of the fuel cell stack.

[0012] Optionally, the first preset range includes a first preset value and a second preset value, wherein the first preset value is greater than the second preset value;

[0013] When the pressure difference is greater than the first preset value, it is determined that the first filter is clogged, and the first filter is replaced or restored.

[0014] When the pressure difference is less than the second preset value, it is determined that the second filter is clogged, and the second filter is replaced or restored.

[0015] Optionally, the impurity protection device further includes: a first switching valve and a second switching valve;

[0016] Both the first switching valve and the second switching valve are three-way valves;

[0017] The first switching valve is located between the second pressure sensor and the second filter screen. Both the second pressure sensor and the second filter screen are connected to the first switching valve through pipes. The second switching valve is located between the second filter screen and the fuel cell stack. Both the second filter screen and the fuel cell stack are connected to the second switching valve through pipes. The first switching valve is also connected to the second switching valve through pipes. Both the first switching valve and the second switching valve are also electrically connected to the controller.

[0018] Optionally, under a preset normal gas supply condition, the hydrogen flowing out from the second end of the hydrogen supply solenoid valve passes through the first switching valve, the second filter, and the second switching valve in sequence before entering the fuel cell stack.

[0019] When the controller determines that the second filter is clogged, it controls the first opening of the second switching valve to close, and uses the third opening of the second switching valve as the inlet and the second opening of the second switching valve as the outlet to restore the flow channel.

[0020] At this time, the hydrogen flowing out from the second end of the hydrogen supply solenoid valve passes sequentially through the second opening of the first switching valve, the second opening of the second switching valve, and the second end of the second filter screen, and then flows out from the first opening of the second filter screen.

[0021] Optionally, the impurity protection device may also include: a first switching valve, a second switching valve, and a purge gas source;

[0022] The first switching valve is a two-way valve, and the second switching valve is a three-way valve;

[0023] The first switching valve is located between the second pressure sensor and the second filter screen. The second pressure sensor and the second filter screen are respectively connected to the second opening of the first switching valve and the first opening of the first switching valve. The second switching valve is located between the second filter screen and the fuel cell stack. The second filter screen and the fuel cell stack are respectively connected to the second opening of the second switching valve and the first opening of the second switching valve.

[0024] The second switching valve is also connected to the third opening of the purge air source, and the second switching valve is also electrically connected to the controller. The purge air source is also electrically connected to the controller.

[0025] Optionally, under a preset normal gas supply condition, the hydrogen flowing out from the second end of the hydrogen supply solenoid valve passes through the first switching valve, the second filter, and the second switching valve in sequence before entering the fuel cell stack.

[0026] When the controller determines that the second filter is clogged, it controls the first opening of the first switching valve to close and the first opening of the second switching valve to close, using the third opening of the second switching valve as the inlet and the second opening of the second switching valve as the outlet to restore the flow channel.

[0027] At this time, the gas provided by the purge gas source passes through the third opening of the second switching valve and the second opening of the second switching valve in sequence, is blown into the second end of the second filter screen, and then flows out from the first opening of the second filter screen.

[0028] The gas pressure used for reverse purging and cleaning is the same as or lower than the preset rated working pressure. The controller controls the purging gas source to adjust the purging flow rate and time.

[0029] Optionally, after the second filter screen is purged and cleaned, the controller controls the air supply circuit to return to the preset normal air supply state, and then reads the first pressure value measured by the first pressure sensor and the second pressure value measured by the second pressure sensor again, and compares whether the pressure difference between the first pressure value and the second pressure value is within the first preset range under the first preset working conditions.

[0030] If the pressure difference recovers to the first preset range and the power generation of the fuel cell stack recovers to a value greater than or equal to the preset power, then the purging operation is completed.

[0031] If the pressure difference does not return to the normal range and the power generation of the fuel cell stack is still less than the preset power, the purging procedure is repeated until the pressure difference returns to the normal range and the power generation of the fuel cell stack returns to the normal value.

[0032] In a second aspect, embodiments of the present invention also provide an impurity protection method for a fuel cell hydrogen supply system using the impurity protection device described in the first aspect, comprising:

[0033] The controller reads the first pressure value measured by the first pressure sensor and the second pressure value measured by the second pressure sensor;

[0034] Under preset operating conditions, compare whether the pressure difference between the first pressure value and the second pressure value is within a preset range;

[0035] When the pressure difference is outside the preset range, it is determined that the first filter or the second filter is clogged.

[0036] Optionally, the impurity protection method further includes:

[0037] When the controller determines that the second filter is clogged, it controls the first opening of the second switching valve to close, and uses the third opening of the second switching valve as the inlet and the second opening of the second switching valve as the outlet to restore the flow channel.

[0038] At this time, the hydrogen flowing out from the second end of the hydrogen supply solenoid valve passes sequentially through the second opening of the first switching valve, the second opening of the second switching valve, and the second end of the second filter screen, and then flows out from the first opening of the second filter screen.

[0039] Optionally, the impurity protection method further includes:

[0040] When the controller determines that the second filter is clogged, it controls the first opening of the first switching valve to close and the first opening of the second switching valve to close, using the third opening of the second switching valve as the inlet and the second opening of the second switching valve as the outlet to restore the flow channel.

[0041] At this time, the gas supplied by the purge gas source passes through the third opening of the second switching valve and the second opening of the second switching valve in sequence, is blown into the second end of the second filter screen, and then flows out from the first opening of the second filter screen.

[0042] The gas pressure used for reverse purging and cleaning is the same as or lower than the preset rated working pressure. The controller controls the purging gas source to adjust the purging flow rate and time.

[0043] This invention provides an impurity protection device and method for a fuel cell hydrogen supply system. The device includes a first pressure sensor located at the first end of a first filter and a second pressure sensor located at the second end of a circulation device. Under first preset operating conditions, a controller compares the pressure difference between a first pressure value and a second pressure value within a first preset range. If the pressure difference is outside the first preset range, the controller determines that either the first or second filter is clogged. In this embodiment, when the pressure difference is outside the first preset range, the controller determines that either the first or second filter is clogged and restores the power output of the fuel cell stack by adjusting the flow rate of the hydrogen supply solenoid valve. This method can filter impurities and adjust in time when clogs occur, thereby ensuring the fuel cell stack can output power normally.

[0044] It should be understood that the description in this section is not intended to identify key or essential features of the embodiments of the present invention, nor is it intended to limit the scope of the invention. Other features of the invention will become readily apparent from the following description. Attached Figure Description

[0045] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0046] Figure 1 This is a schematic diagram of the structure of an impurity protection device for a fuel cell hydrogen supply system provided in an embodiment of the present invention;

[0047] Figure 2 A schematic diagram of the structure of an impurity protection device for another fuel cell hydrogen supply system provided in an embodiment of the present invention;

[0048] Figure 3A schematic diagram of the structure of an impurity protection device for another fuel cell hydrogen supply system provided in an embodiment of the present invention;

[0049] Figure 4 A flowchart of an impurity protection method for a fuel cell hydrogen supply system provided in an embodiment of the present invention;

[0050] Figure 5 A flowchart of another impurity protection method for a fuel cell hydrogen supply system provided in an embodiment of the present invention;

[0051] Figure 6 A flowchart of another impurity protection method for a fuel cell hydrogen supply system provided in an embodiment of the present invention. Detailed Implementation

[0052] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0053] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0054] Figure 1 This is a schematic diagram of the structure of an impurity protection device for a fuel cell hydrogen supply system provided in an embodiment of the present invention, with reference to... Figure 1 The fuel cell hydrogen supply system includes a hydrogen cylinder 1, a shut-off valve 2, a pressure reducing valve 3, a hydrogen supply solenoid valve 6, a circulation device 8, and a fuel cell stack 11, all connected in sequence via pipelines. (Continue to refer to...) Figure 1 The impurity protection device includes: a first pressure sensor 4, a first filter 5, a second pressure sensor 7, a second filter 9, and a controller 10. The first filter 5 is located at the first end of the hydrogen supply solenoid valve 6, and the second filter 9 is located at the first end of the fuel cell stack 11.

[0055] The hydrogen supply solenoid valve 6 uses a switch control or PWM control method to regulate the amount of hydrogen flowing out from the second end of the hydrogen supply solenoid valve 6.

[0056] Understandably, due to the presence of moving parts and wear surfaces inside the hydrogen supply solenoid valve 6, a first filter screen 5 needs to be installed at the first end of the hydrogen supply solenoid valve 6 to prevent the influence of particulate impurities in the abnormal pipeline. The first filter screen 5 can be made of 100-300 mesh austenitic stainless steel mesh or plastic mesh, and can be in the form of woven mesh, laser-formed perforated mesh, additive manufacturing perforated mesh, etc. The second filter screen 9 mainly filters particulate impurities that may be generated or present in the hydrogen supply solenoid valve 6 and pipeline, and can be made of 5-30μm precision austenitic stainless steel dense mesh, engineering plastic microporous membrane, etc. In this embodiment of the invention, the second filter screen 9 is made of nylon membrane, and the flow area of ​​the second filter screen 9 is more than 3 times the flow area of ​​the pipeline.

[0057] In this embodiment of the invention, hydrogen flows out from hydrogen cylinder 1, passes through shut-off valve 2 and pressure reducing valve 3, flows through pipeline through first filter screen 5 and then enters hydrogen supply solenoid valve 6. After flowing out from the second end of hydrogen supply solenoid valve 6, it flows through pipeline through circulation device 8 and second filter screen 9 respectively and then enters fuel cell stack 11.

[0058] Continue to refer to Figure 1 The first pressure sensor 4 is located at the first end of the first filter screen 5, and the second pressure sensor 7 is located at the second end of the circulation device 8. The first pressure sensor 4, the second pressure sensor 7, and the hydrogen supply solenoid valve 6 are all electrically connected to the controller 10.

[0059] In this embodiment of the invention, the controller 10 is used to read the first pressure value measured by the first pressure sensor 4 and the second pressure value measured by the second pressure sensor 7, and compare the pressure difference between the first pressure value and the second pressure value under the first preset operating conditions. If the pressure difference is outside the first preset range, it is determined that the first filter 5 or the second filter 9 is blocked. The controller 10 is also used to adjust the flow rate of the hydrogen supply solenoid valve 6 to restore the power generation of the fuel cell stack 11.

[0060] The first preset operating condition can be the normal operating condition of the fuel cell stack 11.

[0061] Understandably, when the first filter 5 or the second filter 9 becomes clogged, the power generation of the fuel cell stack 11 will decrease. The system performance indicators can be restored in time by adjusting the flow rate of the hydrogen supply solenoid valve 6 through the controller 10, that is, the power generation of the fuel cell stack 11 can be restored.

[0062] When the pressure difference in this embodiment of the invention is outside the first preset range, the controller 10 determines that the first filter 5 or the second filter 9 is blocked, and restores the power generation of the fuel cell stack 11 by adjusting the flow rate of the hydrogen supply solenoid valve 6. This allows for the filtering of impurities and timely adjustment when blockage occurs, thus ensuring the normal power output of the fuel cell stack 11.

[0063] Optionally, based on the above embodiments, the first preset range includes a first preset value and a second preset value, wherein the first preset value is greater than the second preset value. When the pressure difference is greater than the first preset value, it is determined that the first filter 5 is clogged, and the first filter 5 is replaced or restored. When the pressure difference is less than the second preset value, it is determined that the second filter 9 is clogged, and the second filter 9 is replaced or restored.

[0064] The first filter 5 has larger pores and a lower probability of clogging. In this embodiment, it is replaced to address potential clogging issues. The second filter 9 has higher precision and is located after the moving parts of the hydrogen supply solenoid valve 6, making it more likely to clog more frequently. In this embodiment, a recovery method is used to improve the operating time of the fuel cell hydrogen supply system.

[0065] It is understood that the recovery in this embodiment of the invention refers to the automatic cleaning of impurities clogged in the second filter 9 by the controller 10.

[0066] Figure 2 This is a schematic diagram of the structure of an impurity protection device for a fuel cell hydrogen supply system provided in an embodiment of the present invention. Optionally, based on the above embodiments, refer to... Figure 2 ,compared to Figure 1 The impurity protection device further includes a first switching valve 12 and a second switching valve 13. Both the first switching valve 12 and the second switching valve 13 are three-way valves. The first switching valve 12 is located between the second pressure sensor 7 and the second filter screen 9. Both the second pressure sensor 7 and the second filter screen 9 are connected to the first switching valve 12 via pipes. The second switching valve 13 is located between the second filter screen 9 and the fuel cell stack 11. Both the second filter screen 9 and the fuel cell stack 11 are connected to the second switching valve 13 via pipes. The first switching valve 12 is also connected to the second switching valve 13 via pipes. Both the first switching valve 12 and the second switching valve 13 are also electrically connected to the controller 10.

[0067] In this embodiment of the invention, the first switching valve 12 and the second switching valve 13 are both electrically connected to the controller 10. The controller 10 can adjust the opening state of the first switching valve 12 and the second switching valve 13, thereby restoring the function of the second filter screen 9.

[0068] Optionally, based on the above embodiments, continue to refer to... Figure 2Under the preset normal gas supply condition, the hydrogen flowing out from the second end of the hydrogen supply solenoid valve 6 passes through the first switching valve 12, the second filter screen 9, and the second switching valve 13 in sequence before entering the fuel cell stack 11.

[0069] Under normal gas supply conditions, hydrogen flowing out from the second end of the hydrogen supply solenoid valve 6 passes through the first switching valve 12, flows out from the first opening 12A of the first switching valve 12, passes through the second filter screen 9, flows out from the first opening 13A of the second switching valve 13, and then enters the fuel cell stack 11.

[0070] When the controller 10 determines that the second filter 9 is clogged, it controls the first opening 13A of the second switching valve 13 to close, using the third opening 13C of the second switching valve 13 as the inlet and the second opening 13B of the second switching valve 13 as the outlet to restore the flow channel. At this time, the hydrogen flowing out from the second end of the hydrogen supply solenoid valve 6 passes sequentially through the second opening 12B of the first switching valve 12, the second opening 13B of the second switching valve 13, and the second end of the second filter 9, and then flows out from the first opening of the second filter 9.

[0071] This invention embodiment can achieve reverse purging and cleaning of the second filter 9 and restore its function. The gas pressure used for reverse purging and cleaning is the same as the rated working pressure. The flow rate and time of purging are adjusted by controlling the duty cycle of the hydrogen supply solenoid valve 6 through the controller 10. The purging and cleaning time can be 0.5-5 seconds.

[0072] Figure 3 This is a schematic diagram of the structure of an impurity protection device for a fuel cell hydrogen supply system provided in an embodiment of the present invention. Optionally, based on the above embodiments, compared to... Figure 1 The impurity protection device also includes: a first switching valve 12, a second switching valve 13, and a purge air source 14. The first switching valve 12 is a two-way valve, and the second switching valve 13 is a three-way valve.

[0073] Among them, the purging air source 14 is an external clean air source.

[0074] Continue to refer to Figure 3 The first switching valve 12 is located between the second pressure sensor 7 and the second filter 9. The second pressure sensor 7 and the second filter 9 are respectively connected to the second opening 12B and the first opening 12A of the first switching valve 12. The second switching valve 13 is located between the second filter 9 and the fuel cell stack 11. The second filter 9 and the fuel cell stack 11 are respectively connected to the second opening 13B and the first opening 13A of the second switching valve 13. The second switching valve 13 is also connected to a purge gas source 14, which is connected to the third opening 13C of the second switching valve 13. The second switching valve 13 is also electrically connected to the controller 10, and the purge gas source 14 is also connected to the controller 10.

[0075] In this embodiment of the invention, the first switching valve 12, the second switching valve 13, and the purge air source 14 are all electrically connected to the controller 10. The controller 10 can adjust the opening state of the first switching valve 12 and the second switching valve 13, and control the purge air source 14 to supply gas, thereby restoring the function of the second filter 9.

[0076] Optionally, based on the above embodiments, continue to refer to... Figure 3 Under the preset normal gas supply condition, the hydrogen flowing out from the second end of the hydrogen supply solenoid valve 6 passes through the first switching valve 12, the second filter screen 9, and the second switching valve 13 in sequence before entering the fuel cell stack 11.

[0077] When the controller 10 determines that the second filter 9 is clogged, it controls the first opening 12A of the first switching valve 12 to close, and controls the first opening 13A of the second switching valve 13 to close, so that the third opening 13C of the second switching valve 13 is used as the inlet and the second opening 13B of the second switching valve 13 is used as the outlet to restore the flow channel. At this time, the gas provided by the purge gas source 14 passes through the third opening 13C and the second opening 13B of the second switching valve 13 in sequence, is blown into the first end of the second filter 9, and then flows out from the first opening of the second filter 9.

[0078] The gas pressure used for reverse purging and cleaning is the same as or lower than the preset rated working pressure. The purging gas source 14 is controlled by the controller 10 to adjust the purging flow rate and time.

[0079] Specifically, the purging time can be 0.5-10 seconds.

[0080] The embodiments of the present invention can reverse the blowing and cleaning of the second filter 9 and restore its function.

[0081] Optionally, based on the above embodiments, after the second filter 9 is purged and cleaned, the controller 10 controls the air supply path to return to the preset normal air supply state, and then reads the first pressure value measured by the first pressure sensor 4 and the second pressure value measured by the second pressure sensor 7 again, and compares whether the pressure difference between the first pressure value and the second pressure value is within the first preset range under the first preset operating conditions. If the pressure difference returns to the first preset range and the power generation of the fuel cell stack 11 returns to a value greater than or equal to the preset power, the purging operation is completed. If the pressure difference does not return to the normal range and the power generation of the fuel cell stack 11 is still less than the preset power, the purging procedure is repeated until the pressure difference returns to the normal range and the power generation of the fuel cell stack 11 returns to the normal value.

[0082] The purging process can be repeated 2-3 times.

[0083] Figure 4 A flowchart of an impurity protection method for a fuel cell hydrogen supply system provided in an embodiment of the present invention is shown below. Figure 4 The present invention also provides an impurity protection method for a fuel cell hydrogen supply system using the impurity protection device provided in the above embodiments, the method comprising the following steps:

[0084] S110, The controller reads the first pressure value measured by the first pressure sensor and the second pressure value measured by the second pressure sensor.

[0085] S120. Under preset working conditions, compare whether the pressure difference between the first pressure value and the second pressure value is within the preset range.

[0086] S130. When the pressure difference is outside the preset range, it is determined that the first filter or the second filter is clogged.

[0087] Figure 5 The flowchart illustrates another impurity protection method for a fuel cell hydrogen supply system provided in this embodiment of the invention. Optionally, based on the above embodiments, refer to... Figure 5 The method includes the following steps:

[0088] S210, The controller reads the first pressure value measured by the first pressure sensor and the second pressure value measured by the second pressure sensor.

[0089] S220. Under preset working conditions, compare whether the pressure difference between the first pressure value and the second pressure value is within the preset range.

[0090] S230. When the pressure difference is outside the preset range, it is determined that the first filter or the second filter is clogged.

[0091] S240. When the controller determines that the second filter is clogged, it controls the first opening of the second switching valve to close, and uses the third opening of the second switching valve as the inlet and the second opening of the second switching valve as the outlet to restore the flow channel.

[0092] At this time, refer to Figure 2 Hydrogen gas flowing out from the second end of the hydrogen supply solenoid valve 6 passes sequentially through the second opening 12B of the first switching valve 12, the second opening 13B of the second switching valve 13, and the second end of the second filter screen 9, and then flows out from the first opening of the second filter screen 9.

[0093] Figure 6 The flowchart illustrates another impurity protection method for a fuel cell hydrogen supply system provided in this embodiment of the invention. Optionally, based on the above embodiments, refer to... Figure 6 The method includes the following steps:

[0094] S310, The controller reads the first pressure value measured by the first pressure sensor and the second pressure value measured by the second pressure sensor 7.

[0095] S320. Under preset working conditions, compare whether the pressure difference between the first pressure value and the second pressure value is within the preset range.

[0096] S330. When the pressure difference is outside the preset range, it is determined that the first filter or the second filter is clogged.

[0097] S340. When the controller determines that the second filter is clogged, it controls the first opening of the first switching valve to close and the first opening of the second switching valve to close, using the third opening of the second switching valve as the inlet and the second opening of the second switching valve as the outlet to restore the flow channel.

[0098] At this time, refer to Figure 3 The gas supplied by the purge gas source 14 passes through the third opening 13C and the second opening 13B of the second switching valve 13 in sequence, is blown into the second end of the second filter screen 9, and then flows out from the first opening of the second filter screen 9.

[0099] The gas pressure used for reverse purging and cleaning is the same as or lower than the preset rated working pressure. The purging gas source 14 is controlled by the controller 10 to adjust the purging flow rate and time.

[0100] The aforementioned impurity protection methods for fuel cell hydrogen supply systems are all used in the impurity protection devices of fuel cell hydrogen supply systems provided in any embodiment of the present invention, and are executed by the controller 10, thus possessing the same beneficial effects. Technical details not described in detail in this embodiment can be found in the impurity protection devices of fuel cell hydrogen supply systems provided in any embodiment of the present invention.

[0101] The specific embodiments described above do not constitute a limitation on the scope of protection of this invention. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this invention should be included within the scope of protection of this invention.

Claims

1. An impurity protection device for a fuel cell hydrogen supply system, characterized in that, include: A first pressure sensor, a first filter, a second pressure sensor, a second filter, and a controller; The first filter screen is disposed at the first end of the hydrogen supply solenoid valve, and the second filter screen is disposed at the first end of the fuel cell stack. Hydrogen flows out of the hydrogen cylinder, passes through the first filter screen via a pipeline, and then enters the hydrogen supply solenoid valve. After flowing out from the second end of the hydrogen supply solenoid valve, it passes through the circulation device and the second filter screen via a pipeline before entering the fuel cell stack. The first pressure sensor is located at the first end of the first filter screen, i.e., the hydrogen inlet end; the second pressure sensor is located at the second end of the circulation device, i.e., the hydrogen outlet end; the controller is connected to the first pressure sensor, the second pressure sensor and the hydrogen supply solenoid valve respectively. The controller is used to read the first pressure value measured by the first pressure sensor and the second pressure value measured by the second pressure sensor, and compare the pressure difference between the first pressure value and the second pressure value under the first preset operating conditions. If the pressure difference is outside the first preset range, it is determined that the first filter or the second filter is blocked. When the first filter or the second filter is blocked, the controller is also used to adjust the flow rate of the hydrogen supply solenoid valve to restore the power generation of the fuel cell stack. The first preset operating conditions are the normal operating conditions of the fuel cell stack. The first preset range includes a first preset value and a second preset value, wherein the first preset value is greater than the second preset value; When the pressure difference is greater than the first preset value, it is determined that the first filter is clogged, and the first filter is replaced or restored. When the pressure difference is less than the second preset value, it is determined that the second filter is clogged, and the second filter is replaced or restored.

2. The impurity protection device for the fuel cell hydrogen supply system according to claim 1, characterized in that, Also includes: First switching valve and second switching valve; Both the first switching valve and the second switching valve are three-way valves; The first switching valve is located between the second pressure sensor and the second filter screen. Both the second pressure sensor and the second filter screen are connected to the first switching valve through pipes. The second switching valve is located between the second filter screen and the fuel cell stack. Both the second filter screen and the fuel cell stack are connected to the second switching valve through pipes. The first switching valve is also connected to the second switching valve through pipes. Both the first switching valve and the second switching valve are also electrically connected to the controller.

3. The impurity protection device for the fuel cell hydrogen supply system according to claim 2, characterized in that, Under the preset normal gas supply condition, the hydrogen flowing out from the second end of the hydrogen supply solenoid valve enters the fuel cell stack after passing through the first opening of the first switching valve, the second filter, and the first opening of the second switching valve in sequence. The second filter and the fuel cell stack are respectively connected to the second opening of the second switching valve and the first opening of the second switching valve; When the controller determines that the second filter is clogged, it controls the first opening of the second switching valve to close, and the third opening of the second switching valve is used as the inlet and the second opening of the second switching valve as the outlet to restore the flow channel. At this time, the hydrogen flowing out from the second end of the hydrogen supply solenoid valve passes sequentially through the second opening of the first switching valve, the third opening of the second switching valve, the second opening of the second switching valve, and the second end of the second filter screen, and then flows out from the first opening of the second filter screen.

4. The impurity protection device for the fuel cell hydrogen supply system according to claim 1, characterized in that, Also includes: First switching valve, second switching valve, and purge air source; The first switching valve is a two-way valve, and the second switching valve is a three-way valve; The first switching valve is located between the second pressure sensor and the second filter screen. The second pressure sensor and the second filter screen are respectively connected to the second opening of the first switching valve and the first opening of the first switching valve. The second switching valve is located between the second filter screen and the fuel cell stack. The second filter screen and the fuel cell stack are respectively connected to the second opening of the second switching valve and the first opening of the second switching valve. The purge gas source is connected to the third opening of the second switching valve, and the second switching valve is also electrically connected to the controller. The purge gas source is also electrically connected to the controller.

5. The impurity protection device for the fuel cell hydrogen supply system according to claim 4, characterized in that, Under the preset normal gas supply condition, the hydrogen gas flowing out from the second end of the hydrogen supply solenoid valve passes through the first switching valve, the second filter, and the second switching valve in sequence before entering the fuel cell stack. When the controller determines that the second filter is clogged, it controls the first opening of the first switching valve to close and the first opening of the second switching valve to close, using the third opening of the second switching valve as the inlet and the second opening of the second switching valve as the outlet to restore the flow channel. At this time, the gas provided by the purge gas source passes through the third opening of the second switching valve and the second opening of the second switching valve in sequence, is blown into the second end of the second filter screen, and then flows out from the first opening of the second filter screen. The gas pressure used for reverse purging and cleaning is the same as or lower than the preset rated working pressure. The controller controls the purging gas source to adjust the purging flow rate and time.

6. The impurity protection device for the fuel cell hydrogen supply system according to claim 5, characterized in that, After the second filter screen is purged and cleaned, the controller controls the air supply circuit to return to the preset normal air supply state, and then reads the first pressure value measured by the first pressure sensor and the second pressure value measured by the second pressure sensor again, and compares whether the pressure difference between the first pressure value and the second pressure value is within the first preset range under the first preset working conditions. If the pressure difference recovers to the first preset range and the power generation of the fuel cell stack recovers to a value greater than or equal to the preset power, then the purging operation is completed. If the pressure difference does not return to the normal range and the power generation of the fuel cell stack is still less than the preset power, the purging procedure is repeated until the pressure difference returns to the normal range and the power generation of the fuel cell stack returns to the normal value.

7. A method for impurity protection in a fuel cell hydrogen supply system using the impurity protection device according to any one of claims 1-6, characterized in that, include: The controller reads the first pressure value measured by the first pressure sensor and the second pressure value measured by the second pressure sensor; Under the first preset operating conditions, compare whether the pressure difference between the first pressure value and the second pressure value is within the first preset range; When the pressure difference is outside the first preset range, it is determined that the first filter or the second filter is clogged; When the first or second filter becomes clogged, the controller is also used to adjust the flow rate of the hydrogen supply solenoid valve to restore the power generation of the fuel cell stack.

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