Online detection device for fuel cell system

Abstract

The invention belongs to the technical field of fuel cells, and particularly relates to a fuel cell system online detection device which comprises a logic controller, and an air supply mechanism, a flow adjusting mechanism, a fuel cell single cell clamp, an external load and a voltage amplifier which are connected with the logic controller, the air supply mechanism and the flow adjusting mechanism are respectively connected with the fuel cell single cell clamp so as to provide air and fuel gas with set flow for the fuel cell single cell clamp according to an instruction of the logic controller; the fuel cell single cell clamp is connected with an external load; voltage amplifiers are arranged at the two ends of the external load; and the voltage amplifier is an analog amplification circuit and is used for amplifying the voltage at the two ends of the external load to a 0-5V voltage output signal and outputting the voltage output signal, so that online detection is realized. According to the invention, the output voltage difference of the fuel cell under different carbon monoxide contents is detected, and whether the electric pile is in an accelerated poisoning state is judged, so that the system operation condition is changed through the system controller to achieve the effects of protecting the system and prolonging the service life of the system.

Description

Technical Field

[0001] This invention belongs to the field of fuel cell technology, specifically an online testing device for fuel cell systems. Background Technology

[0002] High-temperature proton exchange membrane fuel cells (HT-PEMFCs) are promising energy devices with advantages such as fast reaction kinetics, high tolerance to fuel / air impurities, simple design, and improved hydrothermal management. They are expected to become the next generation of PEMFCs, specifically designed for fuel cell vehicles and combined heat and power (CHP) systems. The basic process involves reforming liquid fuel online into an anode gas suitable for the HT-PEMFC reaction. This gas is then introduced into the anode of the HT-PEMFC stack. Air is pumped into the cathode via a pump or compressor, and the stack temperature is controlled by a thermal management system to ensure stable power generation at a suitable temperature.

[0003] Current research indicates that the composition and content of the gas produced by the reformer in an HT-PEMFC system directly affect the performance and lifespan of the fuel cell stack. When the carbon monoxide content is low, the system lifespan can reach several thousand hours. However, when the carbon monoxide content is high, the poisoning of the anode catalysis is intensified, reducing stack performance and lifespan to less than several hundred hours. Furthermore, during system control, when the reformed gas composition is in a high carbon monoxide state, the system cannot identify the carbon monoxide content online and can only adjust the stack operating point through the controller to obtain the electrical energy required by the external load. This puts the stack in an accelerated poisoning state, significantly reducing its lifespan.

[0004] Based on this, the present invention discloses an online detection device for a fuel cell system. Based on the difference in output voltage of a high-temperature proton exchange membrane fuel cell under different carbon monoxide contents, the device determines the carbon monoxide content of the gas produced by the reforming device of the HT-PEMFC system, and then determines whether the stack is in an accelerated poisoning state. In this way, the system controller changes the system operating conditions to protect the system and extend its service life. Summary of the Invention

[0005] The purpose of this invention is to provide an online detection device for fuel cell systems. Addressing the problem of carbon monoxide poisoning of the fuel cell stack caused by the reforming unit in HT-PEMFC systems, the device detects the carbon monoxide content online to determine if it exceeds a threshold. This allows the system controller to adjust system operating conditions to protect the system and extend its service life.

[0006] The technical solution adopted by the present invention to achieve the above objectives is: an online detection device for a fuel cell system, comprising: a logic controller and an air supply mechanism, a flow regulation mechanism, a fuel cell single cell clamp, an external load, and a voltage amplifier connected thereto;

[0007] The air supply mechanism and the flow regulation mechanism are respectively connected to the fuel cell single cell fixture to provide air and fuel gas at a set flow rate to the fuel cell single cell fixture according to the instructions of the logic controller.

[0008] The fuel cell single-cell clamp is connected to an external load; voltage amplifiers are provided at both ends of the external load.

[0009] The voltage amplifier is an analog amplifier circuit that amplifies the voltage across the external load to a 0-5V output signal for online detection.

[0010] The air supply mechanism includes: an air pump, an air supply pipe, and an air solenoid valve;

[0011] The air pump is connected to the logic controller and is used to receive instructions from the logic controller to control the start and stop of the air pump, and at the same time, to adjust the amount of air drawn by the air pump.

[0012] The air pump is connected to the fuel cell single cell clamp via an air supply pipe to supply air to the fuel cell single cell clamp.

[0013] The air solenoid valve is installed on the air supply pipeline and connected to the logic controller, and is used to receive instructions from the logic controller to control the opening and closing of the air supply pipeline.

[0014] The flow regulation mechanism includes a mass flow controller, a fuel gas supply pipeline, and a fuel gas solenoid valve; the input end of the mass flow controller is connected to the fuel processor, and the output end is connected to the fuel cell single cell clamp through the fuel gas supply pipeline.

[0015] The mass flow controller is connected to the logic controller and is used to adjust the flow rate of fuel gas delivered by the mass flow controller according to the instructions of the logic controller; the mass flow controller supplies a set amount of fuel gas to the fuel cell single cell fixture through the fuel gas supply pipeline.

[0016] The fuel gas supply pipeline is equipped with a fuel gas solenoid valve connected to a logic controller, which is used to receive instructions from the logic controller to control the opening and closing of the fuel gas supply pipeline.

[0017] The fuel cell single-cell clamp includes: a fixing screw, an outer end plate, an insulating plate, a current collector, a bipolar plate, and a membrane electrode assembly;

[0018] The outer end plate, insulating plate, current collector plate and bipolar plate are each provided in pairs and are fixedly connected sequentially from top to bottom or from bottom to top respectively;

[0019] Each outer end plate, insulating plate, current collector plate, and bipolar plate are symmetrically arranged, and the membrane electrode assembly is clamped between the two bipolar plates and connected to each of the two bipolar plates respectively; the two outer end plates are locked by a fixing screw to form a complete fuel cell single cell fixture.

[0020] The outer end plate, insulating plate, current collector, bipolar plate and membrane electrode assembly are sequentially connected to each other, and a sealing groove is provided at the connection point. A sealing ring is provided in the sealing groove to prevent leakage of the fuel cell single cell clamp.

[0021] The two outer end plates are respectively connected to the air supply pipe and the fuel gas supply pipe to allow air and fuel gas to pass through the fuel cell single cell clamp. At the same time, the two outer end plates respectively discharge the air exhaust gas and fuel gas exhaust gas after the reaction to the exhaust gas recovery device.

[0022] Each of the two external end plates is provided with a terminal block. The output terminal of one terminal block is connected to the positive terminal of the external load via an electromagnetic switch, and the output terminal of the other terminal block is connected to the negative terminal of the external load. The input terminals of the two terminal blocks are respectively connected to the current collector.

[0023] The external load is any one or a combination of two of the following: a variable resistor and a variable capacitor.

[0024] The outer end plate is made of any one of the high-rigidity materials: stainless steel, aluminum alloy, or carbon fiber.

[0025] One of the outer end plates is provided with an air inlet and an air outlet; the other outer end plate is provided with a fuel gas inlet and a fuel gas outlet.

[0026] One end of the air inlet is connected to the air supply pipe via a connector, and the other end is connected to the air inlet on the insulating plate. The air outlet is connected to the waste gas recovery device.

[0027] The fuel gas inlet is connected to the fuel gas supply pipeline, and the other end is connected to the inlet on the insulating plate. The fuel gas outlet is connected to the waste gas recovery device.

[0028] The length of the outer end plate is greater than the length of the insulating plate, current collector, bipolar plate and membrane electrode assembly; and each outer end plate has through holes on both sides for fixing the screw rod to pass through, so as to lock the two outer end plates with the screw rod and nut to clamp the insulating plate, current collector, bipolar plate and membrane electrode assembly.

[0029] The insulating board is any one of polyphenylene sulfide, polyetheretherketone, or epoxy resin.

[0030] Both insulating plates are disposed between the two outer end plates, the two insulating plates are arranged opposite each other, and each insulating plate abuts against the corresponding outer end plate;

[0031] At the air inlet and air outlet of the outer end plate, as well as the fuel gas inlet and fuel gas outlet, there are corresponding insulation plate inlet and outlet holes that connect the outer end plate and the insulation plate.

[0032] The substrate of the current collector is either stainless steel or aluminum alloy, and its coating is any one of gold, silver or carbon conductive material.

[0033] Both current collectors are disposed between two insulating plates, the two current collectors are arranged opposite each other, and each current collector abuts against the corresponding insulating plate;

[0034] At the through hole of the insulating plate, there are corresponding air inlet and outlet holes of the current collector plate that connect the insulating plate and the current collector plate;

[0035] The bipolar plate is a hollow plate with a planar outer surface; the inner surface of the bipolar plate is configured as a gas flow field structure, and the flow field region of the gas flow field corresponds to the effective region of the membrane electrode.

[0036] The gas flow field structure of the bipolar plate can be any one of the following: serpentine, straight, cross-shaped, or tree-shaped.

[0037] Both bipolar plates are disposed between two current collectors, the two bipolar plates are arranged opposite each other, and each bipolar plate abuts against the corresponding insulating plate;

[0038] At the through hole of the collector plate, there are corresponding bipolar plate inlet and outlet holes that connect the collector plate and the bipolar plate.

[0039] The membrane electrode assembly includes a cathode diffusion layer, a cathode catalyst layer, a high-temperature electrolyte membrane, an anode catalyst layer, and an anode diffusion layer stacked sequentially.

[0040] A polymer layer is provided between the cathode diffusion layer and the cathode catalyst layer and / or between the anode diffusion layer and the anode catalyst layer;

[0041] The high-temperature electrolyte membrane is an acid-doped membrane; wherein the doping acid in the acid-doped membrane is one or more of the following: sulfuric acid, phosphoric acid, polyphosphoric acid, polyvinylphosphoric acid, methanesulfonic acid, and trifluoroalkyl sulfonic acid; and the membrane itself is a type of polybenzimidazole membrane.

[0042] The polymer layer has a nanofiber network structure layer; the polymer polymer in the polymer layer is one or more of polyimide, polyetherimide, sulfonated polyimide, sulfonated polyether ether ketone, polybenzimidazole and polyvinylidene fluoride.

[0043] The current at any operating point within the operating temperature range of the membrane electrode assembly corresponds to different output voltages under mixed gases with different carbon monoxide contents.

[0044] It also includes: temperature control device;

[0045] The temperature control device is fixed to the bottom of the fuel cell single cell clamp and is used to feed back the temperature value of the fuel cell single cell clamp to the logic controller, and realize temperature regulation control according to the instructions of the logic controller.

[0046] The temperature control device includes: a PID temperature controller and a heating rod and a thermocouple fixed on the outer end plate;

[0047] The thermocouple is fixed to the outer end plate and is used to send the measured temperature of the fuel cell single cell clamp to the PID temperature controller for temperature regulation.

[0048] The heating rods are evenly laid on the outer end plate of the fuel cell single cell fixture and are connected to the PID temperature controller and the logic controller respectively. They are used to receive start and stop commands from the logic controller to perform start or stop operations, and at the same time, receive temperature adjustment commands from the PID temperature controller to control the temperature of the heating rods.

[0049] The present invention has the following beneficial effects and advantages:

[0050] This invention is based on a high-temperature proton exchange membrane electrode to detect the difference in output voltage of a fuel cell under different carbon monoxide contents, determine the carbon monoxide content of the gas produced by the reforming unit of the HT-PEMFC system, and then determine whether the fuel cell stack is in an accelerated poisoning state. In this way, the system controller can change the system operating conditions to protect the system and extend its service life. Attached Figure Description

[0051] Figure 1 This is a schematic diagram of the online testing device for the fuel cell system of the present invention;

[0052] Among them, 1 is the air supply mechanism, 2 is the flow regulation mechanism, 3 is the fuel cell single cell clamp, 4 is the external load, 5 is the voltage amplifier, 6 is the temperature control device, and 7 is the logic controller.

[0053] Figure 2 The image shows the IV curves of the membrane electrode of the present invention under different CO composition conditions. Detailed Implementation

[0054] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments.

[0055] The purpose of this invention is to provide an online detection device for fuel cell systems. Addressing the problem of carbon monoxide poisoning of the fuel cell stack caused by the reforming unit in HT-PEMFC systems, the device detects the carbon monoxide content online to determine if it exceeds a threshold. This allows the system controller to adjust system operating conditions to protect the system and extend its service life.

[0056] like Figure 1 The diagram shown is a schematic of the online testing device for a fuel cell system according to the present invention. The online testing device for a fuel cell system according to the present invention includes: a logic controller 7 and an air supply mechanism 1, a flow regulation mechanism 2, a fuel cell single cell clamp 3, an external load 4, and a voltage amplifier 5 connected thereto.

[0057] The air supply mechanism 1 and the flow regulation mechanism 2 are respectively connected to the fuel cell single cell clamp 3 to provide the fuel cell single cell clamp 3 with air and fuel gas at a set flow rate according to the instructions of the logic controller 7.

[0058] The fuel cell single cell clamp 3 is connected to the external load 4; a voltage amplifier 5 is provided at both ends of the external load 4; wherein, the external load 4 is any one or a combination of two of the following: a variable resistor and a variable capacitor.

[0059] Voltage amplifier 5 is an analog amplifier circuit that amplifies the voltage across the external load 4 to a voltage output signal of 0-5V to achieve online detection;

[0060] The present invention also includes: a temperature control device 6;

[0061] The temperature control device 6 is fixed to the bottom of the fuel cell single cell clamp 3, and is used to feed back the temperature value of the fuel cell single cell clamp 3 to the logic controller 7, and realize temperature regulation control according to the instructions of the logic controller 7.

[0062] Temperature control device 6 includes: a PID temperature controller and a heating rod and thermocouple fixed on the outer end plate;

[0063] The thermocouple is fixed to the outer end plate and is used to send the measured temperature of the fuel cell single cell clamp 3 to the PID temperature controller for temperature regulation.

[0064] Heating rods are evenly laid on the outer end plate of the fuel cell single cell clamp 3 and are connected to the PID temperature controller and the logic controller 7 respectively. They are used to receive start and stop commands from the logic controller 7 to perform start or stop operations, and at the same time, receive temperature adjustment commands sent by the PID temperature controller to control the temperature of the heating rods.

[0065] 1) Air supply system

[0066] Air supply mechanism 1 includes: an air pump, an air supply duct, and an air solenoid valve;

[0067] The air pump is connected to the logic controller 7 and is used to receive instructions from the logic controller 7 to control the start and stop of the air pump, and at the same time, to adjust the amount of air drawn by the air pump.

[0068] An air pump is connected to the fuel cell single cell clamp 3 via an air supply pipe to supply air to the fuel cell single cell clamp 3;

[0069] An air solenoid valve is installed on the air supply pipe and connected to the logic controller 7. It is used to receive instructions from the logic controller 7 to control the opening and closing of the air supply pipe.

[0070] 2) Flow regulating mechanism

[0071] The flow regulation mechanism 2 includes: a mass flow controller, a fuel gas supply pipeline, and a fuel gas solenoid valve; the input end of the mass flow controller is connected to the fuel processor, and the output end is connected to the fuel cell single cell clamp 3 through the fuel gas supply pipeline.

[0072] The mass flow controller is connected to the logic controller 7 and is used to adjust the flow rate of fuel gas delivered by the mass flow controller according to the instructions of the logic controller 7; the mass flow controller supplies a set amount of fuel gas to the fuel cell single cell clamp 3 through the fuel gas supply pipeline.

[0073] A fuel gas solenoid valve connected to the logic controller 7 is installed on the fuel gas supply pipeline to receive instructions from the logic controller 7 to control the opening and closing of the fuel gas supply pipeline.

[0074] 3) Fuel cell single-cell clamp

[0075] The fuel cell single-cell clamp 3 includes: a fixing screw, an outer end plate, an insulating plate, a current collector, a bipolar plate, and a membrane electrode assembly;

[0076] The outer end plate, insulating plate, current collector plate and bipolar plate are each provided in pairs, and are fixedly connected sequentially from top to bottom or from bottom to top respectively;

[0077] Each outer end plate, insulating plate, current collector plate and bipolar plate are symmetrically arranged, and the membrane electrode assembly is clamped between the two bipolar plates and connected to the two bipolar plates respectively; the two outer end plates are locked by the fixing screw to form a complete fuel cell single cell fixture 3;

[0078] The outer end plate, insulating plate, current collector, bipolar plate and membrane electrode assembly are connected to each other in sequence, and a sealing groove is provided at the connection point. A sealing ring is provided in the sealing groove to prevent leakage of fuel cell single cell clamp 3.

[0079] The two outer end plates are connected to the air supply pipe and the fuel gas supply pipe respectively, which are used to pass air and fuel gas to the fuel cell single cell clamp 3. At the same time, the two outer end plates discharge the air exhaust gas and fuel gas exhaust gas after the reaction to the exhaust gas recovery device respectively.

[0080] Two external end plates are respectively provided with terminals. The output terminal of one terminal is connected to the positive terminal of the external load 4 through an electromagnetic switch, and the output terminal of the other terminal is connected to the negative terminal of the external load 4. The input terminals of the two terminals are respectively connected to the current collector.

[0081] 3.1) Outer end plate

[0082] The outer end plate is made of any one of the high-rigidity materials: stainless steel, aluminum alloy, or carbon fiber.

[0083] One of the outer end plates is provided with an air inlet and an air outlet; the other outer end plate is provided with a fuel gas inlet and a fuel gas outlet.

[0084] One end of the air inlet is connected to the air supply pipe via a connector, and the other end is connected to the air inlet on the insulating plate. The air outlet is connected to the waste gas recovery device.

[0085] The fuel gas inlet is connected to the fuel gas supply pipeline, and the other end is connected to the inlet on the insulating plate. The fuel gas outlet is connected to the waste gas recovery device.

[0086] The length of the outer end plate is greater than the length of the insulating plate, current collector, bipolar plate and membrane electrode assembly; and each of the outer end plates has through holes on both sides for fixing the screw rod to pass through, so as to lock the two outer end plates with the screw rod and nut to clamp the insulating plate, current collector, bipolar plate and membrane electrode assembly.

[0087] 3.2) Insulation board

[0088] The insulating board is any one of the insulating materials selected from polyphenylene sulfide, polyetheretherketone, or epoxy resin.

[0089] Both insulating plates are located between the two outer end plates, with the two insulating plates facing each other and each insulating plate abutting against the corresponding outer end plate;

[0090] At the air inlet and air outlet of the outer end plate, as well as the fuel gas inlet and fuel gas outlet, there are corresponding insulation plate inlet and outlet holes that connect the outer end plate and the insulation plate.

[0091] 3.3) Collector Plate

[0092] The substrate of the current collector is either stainless steel or aluminum alloy, and its coating is any one of gold, silver or carbon conductive materials.

[0093] Both current collectors are located between two insulating plates, with the two current collectors facing each other and each current collector abutting against the corresponding insulating plate;

[0094] At the through hole of the insulating plate, there are corresponding air inlet and outlet holes of the current collector plate that connect the insulating plate and the current collector plate;

[0095] 3.4) Bipolar plates

[0096] The bipolar plate is a hollow plate with a planar outer surface; the inner surface of the bipolar plate is set as a gas flow field structure, and the flow field region of the gas flow field corresponds to the effective region of the membrane electrode.

[0097] The gas flow field structure of the bipolar plate can be any one of the following: serpentine, straight, cross-shaped, or tree-shaped.

[0098] Two bipolar plates are positioned between two current collectors, with the two bipolar plates facing each other and each bipolar plate abutting against the corresponding insulating plate.

[0099] At the through hole of the collector plate, there are corresponding bipolar plate inlet and outlet holes that connect the collector plate and the bipolar plate.

[0100] 4) Membrane electrode assembly

[0101] This invention relates to a fuel cell detection device based on a high-temperature proton exchange membrane fuel cell. The membrane electrode assembly used is existing technology. The applicant is the Dalian Institute of Chemical Physics, Chinese Academy of Sciences, application number: 201510939965.1, entitled: A membrane electrode for a high-temperature fuel cell and its preparation and application.

[0102] The membrane electrode assembly includes: a cathode diffusion layer, a cathode catalyst layer, a high-temperature electrolyte membrane, an anode catalyst layer, and an anode diffusion layer stacked sequentially.

[0103] A polymer layer is provided between the cathode diffusion layer and the cathode catalyst layer and / or between the anode diffusion layer and the anode catalyst layer;

[0104] The high-temperature electrolyte membrane is an acid-doped membrane; wherein the doping acid in the acid-doped membrane is one or more of the following: sulfuric acid, phosphoric acid, polyphosphoric acid, polyvinylphosphoric acid, methanesulfonic acid, and trifluoroalkyl sulfonic acid; and the membrane in the acid-doped membrane is one of the following: polybenzimidazole membranes.

[0105] The polymer layer has a nanofiber network structure layer; the polymer polymer in the polymer layer is one or more of polyimide, polyetherimide, sulfonated polyimide, sulfonated polyether ether ketone, polybenzimidazole and polyvinylidene fluoride.

[0106] The current at any operating point within the operating temperature range of the membrane electrode assembly will result in different output voltages under mixed gases with different carbon monoxide contents.

[0107] Example 1:

[0108] An air pump with an air flow range of 0-50L / min is selected. The controller can control the speed of the pump to set the air flow to any point within the range of 0-50L / min. A stainless steel pipe with an inner diameter of 10mm is selected as the air supply pipeline. The solenoid valve is also selected with a nominal diameter of 10mm. All pipeline connections are compression fittings.

[0109] A mass flow controller with a flow range of 0-20 L / min is selected. The controller can set the fuel gas flow rate to any point within the range of 0-20 L / min by controlling its opening. A stainless steel pipe with an inner diameter of 10 mm is selected as the air supply pipeline. The solenoid valve is also selected with a nominal diameter of 10 mm. All pipeline connections are compression fittings.

[0110] The outer end plate of the fuel cell single-cell clamp is made of 316L stainless steel, with dimensions of 120mm × 120mm × 20mm square plate. It connects to the pipeline via a 1 / 2 NPT threaded connection. Gas inlet and outlet holes are located on both sides of the lower part of the two plates. The internal sealing grooves around the holes are standard sealing grooves with a depth of 1.26mm. Screw through holes of φ6.5mm are located around the perimeter of both plates. The insulating plate is made of polyetheretherketone (PEEK), with dimensions of 120mm × 120mm × 6mm square plate, and its through holes correspond to those of the outer end plate. The current collector is made of 316L stainless steel with silver plating, with dimensions of 100mm × 100mm × 6mm square plate. Its through holes correspond to those of the outer end plate, and its sealing grooves are standard sealing grooves with a depth of 1.26mm. The bipolar plate is made of graphite and has an external size of 100mm×100mm×6mm square plate. The through holes on it correspond to the outer end plate, and the internal flow field is a serpentine flow field.

[0111] Select a membrane electrode with an effective area of ​​50 cm². 2 Its IV curves under different CO components, such as Figure 2 As shown. Within its operating temperature range, at a current of 25A, the corresponding voltage values ​​for 0% CO, 1% CO, 2% CO, and 3% CO are 530mV, 470mV, 410mV, and 350mV, respectively.

[0112] The above components are fixed by a fixing screw.

[0113] When the system is running, the inlet pipe of the flow regulating mechanism is connected to the system fuel processor. When it is necessary to detect the fuel gas composition, the controller raises the temperature of the single-cell fixture to 140-150℃, controls the gas pump to provide a flow rate of 5L / min, opens the solenoid valve of the flow regulating mechanism, controls the fuel gas flow rate to 2L / min, controls the output current to 25A by controlling the external load, collects the voltage of the single-cell fixture, and outputs its voltage signal through the voltage amplifier.

[0114] Assuming the CO concentration detection range of this detection device is 0-30000ppm, when the CO concentration of the fuel gas being detected is 2%, the output voltage of its single-cell clamp is 410mV, and the output voltage signal through the voltage amplifier is 3.33V. When the CO concentration of the fuel gas being detected is 0.5%, the output voltage of its single-cell clamp is 500mV, and the output voltage signal through the voltage amplifier is 0.83V.

[0115] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above descriptions are merely specific 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 within the protection scope of the present invention.

Claims

1. A fuel cell system on-line detecting device characterized by comprising: The application relates to a fuel cell single-cell clamp system, which comprises a logic controller (7) and an air supply mechanism (1), a flow regulating mechanism (2), the fuel cell single-cell clamp (3), an external load (4) and a voltage amplifier (5) connected with the logic controller (7). The air supply mechanism (1) and the flow regulating mechanism (2) are connected with the fuel cell single-cell clamp (3) respectively, so that the air supply mechanism (1) and the flow regulating mechanism (2) can provide air and fuel gas with a set flow of the fuel cell single-cell clamp (3) according to the instruction of the logic controller (7). The fuel cell single-cell clamp (3) is connected with the external load (4), and the voltage amplifier (5) is arranged at both ends of the external load (4). The voltage amplifier (5) is an analog amplification circuit, which amplifies the voltage at both ends of the external load (4) to a voltage output signal of 0-5V, so that on-line detection is realized. The air supply mechanism (1) comprises an air pump, an air supply pipeline and an air electromagnetic valve.

2. The on-line fuel cell system detection device according to claim 1, wherein The air pump is connected with the logic controller (7), and is used for receiving the instruction of the logic controller (7) to control the start and stop of the air pump and adjust the air volume extracted by the air pump. The air pump is connected with the fuel cell single-cell clamp (3) through the air supply pipeline, so as to supply air to the fuel cell single-cell clamp (3). The air electromagnetic valve is arranged on the air supply pipeline and is connected with the logic controller (7), and is used for receiving the instruction of the logic controller (7) to control the on-off of the air supply pipeline. The flow regulating mechanism (2) comprises a mass flow controller, a fuel gas supply pipeline and a fuel gas electromagnetic valve.

3. The on-line fuel cell system detection device according to claim 1, wherein The input end of the mass flow controller is connected with a fuel processor, and the output end is connected with the fuel cell single-cell clamp (3) through the fuel gas supply pipeline. The mass flow controller is connected with the logic controller (7), and is used for adjusting the fuel gas flow delivered by the mass flow controller according to the instruction of the logic controller (7). The mass flow controller supplies the fuel cell single-cell clamp (3) with a set amount of fuel gas through the fuel gas supply pipeline. The fuel gas electromagnetic valve is arranged on the fuel gas supply pipeline and is connected with the logic controller (7), and is used for receiving the instruction of the logic controller (7) to control the on-off of the fuel gas supply pipeline.

4. The on-line fuel cell system monitoring device of claim 1, wherein The fuel cell single-cell clamp (3) comprises a fixed screw rod, an outer end plate, an insulating plate, a current collecting plate, a bipolar plate and a membrane electrode assembly. The outer end plate, the insulating plate, the current collecting plate and the bipolar plate are sequentially and fixedly connected in a pair from top to bottom or from bottom to top. Each pair of the outer end plate, the insulating plate, the current collecting plate and the bipolar plate is symmetrical, and the membrane electrode assembly is clamped between the two bipolar plates and connected with the two bipolar plates respectively. The two outer end plates are locked by the fixed screw rod to form a complete fuel cell single-cell clamp (3). The outer end plate, the insulating plate, the current collecting plate, the bipolar plate and the membrane electrode assembly are sequentially and mutually communicated, and a sealing groove is arranged at the communication position and provided with a sealing ring to prevent the fuel cell single-cell clamp (3) from leaking. Two outer end plates are respectively connected to air supply pipeline and fuel gas supply pipeline, for supplying air and fuel gas to fuel cell single cell clamp (3), and simultaneously, two outer end plates respectively discharge reacted air exhaust gas and fuel gas exhaust gas to exhaust gas recovery device; Two outer end plates are respectively connected to air supply pipeline and fuel gas supply pipeline, for supplying air and fuel gas to fuel cell single cell clamp (3), and simultaneously, two outer end plates respectively discharge reacted air exhaust gas and fuel gas exhaust gas to exhaust gas recovery device; One output end of one of the two connection terminals is connected to positive electrode of external load (4) through electromagnetic switch, and the other output end is connected to negative electrode of external load (4) ; input ends of the two connection terminals are respectively connected to current collecting plate; 5. The on-line fuel cell system monitoring device according to claim 4, wherein The external load (4) is any one of variable resistance, variable capacitance or combination of the two. The outer end plate is any one of stainless steel, aluminum alloy or carbon fiber high stiffness material; One of the outer end plates is provided with air inlet hole and air outlet hole, and the other outer end plate is correspondingly provided with fuel gas inlet hole and fuel gas outlet hole; One end of the air inlet hole is connected to air supply pipeline through joint, and the other end is communicated with air inlet hole on insulating plate; air outlet hole is connected to exhaust gas recovery device; The fuel gas inlet hole is connected to fuel gas supply pipeline, and the other end is communicated with air inlet hole on insulating plate; fuel gas outlet hole is connected to exhaust gas recovery device; 6. The on-line fuel cell system monitoring device of claim 4, wherein The length of the outer end plate is greater than the length of insulating plate, current collecting plate, bipolar plate and membrane electrode assembly; and through holes for fixing screw rod are arranged on both sides of the outer end plate, for fixing screw rod and nut locking, so as to clamp insulating plate, current collecting plate, bipolar plate and membrane electrode assembly. The insulating plate is any one of polyphenylene sulfide, polyether ether ketone or epoxy resin insulating material; The two insulating plates are arranged between the two outer end plates, and the two insulating plates are oppositely arranged, and each insulating plate is abutted with corresponding outer end plate; 7. The on-line fuel cell system monitoring device of claim 4, wherein Air inlet hole and air outlet hole of outer end plate are correspondingly provided with insulating plate inlet and outlet holes for communicating outer end plate and insulating plate. The base material of the current collecting plate is any one of stainless steel or aluminum alloy, and the plating layer is any one of gold, silver or carbon conductive material; The two current collecting plates are arranged between the two insulating plates, and the two current collecting plates are oppositely arranged, and each current collecting plate is abutted with corresponding insulating plate; 8. The on-line fuel cell system monitoring device of claim 4, wherein Current collecting plate inlet and outlet holes for communicating insulating plate and current collecting plate are correspondingly arranged at through hole of insulating plate. The bipolar plate is hollow plate, and the outer surface is plane structure; the inner surface of the bipolar plate is provided with gas flow field structure, and the flow field area of the gas flow field corresponds to the effective area of the membrane electrode; The gas flow field structure of the bipolar plate is any one of serpentine, straight, cross and tree shape; The two bipolar plates are arranged between the two current collecting plates, and the two bipolar plates are oppositely arranged, and each bipolar plate is abutted with corresponding insulating plate; 9. The on-line fuel cell system monitoring device of claim 4, wherein Bipolar plate inlet and outlet holes for communicating current collecting plate and bipolar plate are correspondingly arranged at through hole of current collecting plate. The membrane electrode assembly comprises cathode diffusion layer, cathode catalytic layer, high temperature electrolyte membrane, anode catalytic layer and anode diffusion layer which are sequentially stacked; Polymer macromolecular layer is arranged between cathode diffusion layer and cathode catalytic layer and / or between anode diffusion layer and anode catalytic layer. The high-temperature electrolyte membrane is an acid-doped membrane; wherein the doped acid in the acid-doped membrane is one or a mixture of two or more of sulfuric acid, phosphoric acid, polyphosphoric acid, polyvinyl phosphoric acid, methanesulfonic acid and trifluoroalkyl sulfonic acid; and the membrane in the acid-doped membrane is one of polybenzimidazole membranes; The polymer high-molecular layer has a nanofiber network structure layer; the polymer high-molecule in the polymer high-molecular layer is one or two or more of polyimide, polyetherimide, sulfonated polyimide, sulfonated polyether ether ketone, polybenzimidazole and polyvinylidene fluoride; The current at any working point in the working temperature range of the membrane electrode assembly is different in the output voltage corresponding to the mixed gas with different carbon monoxide contents.

10. The on-line fuel cell system monitoring device of claim 1, wherein Further comprising: A temperature control device (6); The temperature control device (6) is fixed at the bottom of the fuel cell single-cell clamp (3), used for feeding back the temperature value of the fuel cell single-cell clamp (3) to the logic controller (7), and realizing temperature regulation control according to the instruction of the logic controller (7); The temperature control device (6) comprises a PID temperature controller, a heating rod and a thermocouple fixed on the outer end plate; The thermocouple is fixed on the outer end plate, used for sending the measured temperature of the fuel cell single-cell clamp (3) to the PID temperature controller for temperature regulation; The heating rod is uniformly laid on the outer end plate of the fuel cell single-cell clamp (3), and is connected with the PID temperature controller and the logic controller (7) respectively, used for receiving the start-stop instruction of the logic controller (7) to execute the start or power-off operation, and receiving the temperature regulation instruction sent by the PID temperature controller to control the temperature of the heating rod.

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