Fuel cell performance online recovery device and method

Abstract

The embodiment of the invention provides a fuel cell performance online recovery device and method. Auxiliary hardware, namely a first electric control on-off valve Va1, a second electric control on-off valve Va2 and a third three-way diverter valve Va3, are additionally arranged on an air path of a fuel cell system. The embodiment of the invention provides a fuel cell performance online recovery device and method. Auxiliary hardware, namely a first electric control on-off valve Va1, a second electric control on-off valve Va2 and a third three-way diverter valve Va3, are additionally arranged on an air path of a fuel cell system. In the operation process of the fuel cell, the CVM monitors each single cell of the stack in real time, the impedance detector monitors the impedance of the stack in real time, and according to the comprehensive judgment of the voltage and the internal dry and wet degree of the stack, the first electric control on-off valve Va1, the second electric control on-off valve Va2 and the third three-way diverter valve Va3 are switched to adjust the air humidity and temperature entering the stack for reaction; and the effect of online recovery of the electric pile performance is achieved, so that the waste of time and manpower resources caused by corresponding recovery means operation of pile disassembly due to the degradation of the electric pile performance is avoided.

Description

Technical Field

[0001] The present invention relates to the technical field of fuel cells, and in particular to an online performance recovery device and method for fuel cells. Background Art

[0002] The use of energy is closely related to people's lives. Until now, the energy used by humans mainly consists of fossil fuels such as coal, oil, and natural gas. These categories are all non-renewable energy sources with limited reserves. Moreover, problems such as the greenhouse effect and environmental pollution caused by the combustion of fossil fuels are gradually emerging. Against this background, the development and utilization of new energy are current hot topics and research categories, including energy types such as solar energy, wind energy, and hydrogen energy. Among them, a proton exchange membrane fuel cell is a device that can directly convert the chemical energy in hydrogen into electrical energy through a mild reaction. Its technical characteristics such as environmental friendliness and high conversion efficiency are considered to be one of the effective solutions to future energy problems.

[0003] With the development of fuel cell technology, various power models of fuel cells have currently been applied to specific scenarios, such as fuel cell buses, fuel cell base stations, fuel cell combined heat and power systems, etc. Although the lifespan of fuel cells has been greatly increased with the upgrading of processes and the iteration of technologies, in the face of various operating environments, conditions, and logics, fuel cells still experience performance degradation due to factors such as extreme conditions, accessory failures, and catalyst poisoning during use. In such cases, most manufacturers remove the fuel cell stack from the terminal ecosystem and perform corresponding performance recovery operations on the stack using an activation test bench. This process wastes a large amount of manpower and material resources.

[0004] How to collect relevant data information to real-time monitor and determine the health status of fuel cells, and when the fuel cell shows obvious performance degradation and does not meet the terminal use requirements, be able to perform online performance recovery operations on the fuel cell is one of the topics that need to be explored currently. Summary of the Invention

[0005] In view of this, the present invention provides an online performance recovery device and method for fuel cells, aiming to solve the inconvenience caused by the need to disassemble and perform corresponding performance recovery operations when the fuel cell stack shows performance degradation, and reduce the relevant labor costs and material costs.

[0006] To this end, the present invention provides the following technical solutions:

[0007] The present invention provides an online performance recovery device for fuel cells, including:

[0008] An air pump, an intercooler, an electronically controlled on-off valve Va2, a humidifier, a fuel cell system, a three-way diverter valve Va3, and a throttle are connected in sequence. A three-way interface is provided between the intercooler and the humidifier, and an electronically controlled on-off valve Va1 is connected in parallel. It merges into the intake air pipeline through the three-way interface between the humidifier and the fuel cell stack. The branch outlet of the three-way diverter valve is separately connected to a path to introduce air into the atmosphere.

[0009] Further, when the fuel cell system does not give the corresponding valve opening instruction, Va1 is in the closed state, and Va3 is in the state where the main path is open and the branch is closed.

[0010] The present invention also provides a method for online recovery of fuel cell performance. Based on the above fuel cell performance online recovery device, the method includes:

[0011] When the fuel cell system starts to operate, the voltage of each single fuel cell is monitored in real time through the CVM, and the impedance value of the entire fuel cell stack is detected in real time by the impedance detector. The performance state and the internal dryness and humidity state of the fuel cell stack are comprehensively judged. By opening and closing the electronically controlled on-off valve Va1 and the electronically controlled on-off valve Va2, the fuel cell performance is recovered online by adjusting the dryness and humidity change of the air intake path and the cathode under-aeration.

[0012] Further, the method further includes:

[0013] During the operation of the fuel cell system, if the performance of the fuel cell stack decays due to internal dryness and humidity changes, the three-way diverter valve is adjusted to change the air volume entering the humidifier, thereby adjusting the intake humidity so that the fuel cell operates within the optimal humidity range.

[0014] Compared with other existing technologies, the present invention has the following beneficial effects:

[0015] In the present invention, an auxiliary hardware, the first electronically controlled on-off valve Va1, the second electronically controlled on-off valve Va2, and the third three-way diverter valve Va3, are added to the air path of the fuel cell system. When the fuel cell is in a normal operating state, the second electronically controlled on-off valve Va2 is opened, the first electronically controlled on-off valve Va1 is closed, and the third three-way diverter valve Va3 is in the state where the main path is open and the branch is closed; when the fuel cell is in an abnormal operating state (performance decay, low single cell, abnormal impedance, etc.), the opening and closing states of the first electronically controlled on-off valve Va1, the second electronically controlled on-off valve Va2, and the third three-way diverter valve Va3 are judged by detecting the corresponding data, and the temperature, flow rate, humidity, etc. of the gas in the air path are changed, combined with the operation method of cathode under-aeration, to achieve the purpose of online recovery of the fuel cell stack. Description of the Drawings

[0016] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required in the description of the embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0017] Figure 1 It is a schematic structural diagram of an on-line performance recovery device for a fuel cell in an embodiment of the present invention. Specific embodiments

[0018] In order to enable those skilled in the art to better understand the solution of the present invention, the following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, rather than all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0019] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above drawings are used to distinguish similar objects, and do not necessarily need to describe a specific order or sequence. It should be understood that such data can be interchanged under appropriate circumstances so that the embodiments of the present invention described here can be implemented in an order other than those illustrated or described here. In addition, the terms "comprising" and "having" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device comprising a series of steps or units does not necessarily have to be limited to those steps or units clearly listed, but may include other steps or units not clearly listed or inherent to these processes, methods, products or devices.

[0020] As Figure 1 shown, an on-line fuel cell performance recovery device provided in an embodiment of the present invention includes:

[0021] An air pump, an intercooler, an electronically controlled on-off valve Va2, a humidifier, a fuel cell system, a three-way flow dividing valve Va3, and a throttle are connected in sequence. A three-way interface is provided between the intercooler and the humidifier, and an electronically controlled on-off valve Va1 is connected in one path, and it merges into the intake pipe through the three-way interface between the humidifier and the fuel cell stack. The branch outlet of the three-way flow dividing valve is separately connected to a path for exhausting air into the atmosphere. When the fuel cell system does not give a corresponding valve opening instruction, Va1 is in a closed state, and Va3 is in a state where the main path is open and the branch is closed.

[0022] Based on the above fuel cell performance online recovery device, an embodiment of the present invention provides a fuel cell performance online recovery method, which includes:

[0023] S1. When the fuel cell system is in a normal operating state, open the second electronically controlled on-off valve Va2, close the first electronically controlled on-off valve Va1, and the third three-way shunt valve Va3 is in a state where the main road is open and the branch is closed;

[0024] During this process, the overall structure of the air path of the fuel cell system is a conventional intake structure;

[0025] S2. During the operation of the fuel cell system, if the CVM detects that the overall performance of the fuel cell stack is low (Vavg@rated current < 0.6V) and the overall stack impedance value is high, reduce the speed of the intercooler series cooling electronic water pump to increase the air intake temperature; reduce the speed of the radiator to increase the stack temperature, and increase the dry inlet temperature and wet inlet temperature of the humidifier, so that the liquid water inside the humidifier vaporizes better, and activate the stack under a high humidity state to reduce the overall stack impedance value and thus recover the stack performance online;

[0026] S3. During the operation of the fuel cell system, if the CVM detects that a single cell voltage of the fuel cell stack is low and the voltage value has an up and down amplitude, close the second electronically controlled on-off valve Va2, open the first electronically controlled on-off valve Va1, and purge the stack with high-temperature dry air to recover the stack performance online;

[0027] S4. During the operation of the fuel cell system, if the CVM detects that the overall performance of the fuel cell stack is low (Vavg@rated current < 0.6V) and the overall stack impedance value is abnormal, adjust the opening relationship between the main road and the branch of the third three-way shunt valve to regulate the air flow rate entering the wet inlet of the humidifier, and reduce the air humidity finally entering the stack to recover the stack performance online;

[0028] S5. During the operation of the fuel cell system, if the CVM detects that the overall performance of the fuel cell stack is low (Vavg@rated current < 0.6V) and the overall stack impedance value has no obvious deviation compared with the normal value, turn off the air pump, wait until the fuel cell voltage value drops to about 0.1V and then resume the air pump speed, and cycle this condition 5 times to recover the stack performance online.

[0029] In the above embodiments, an auxiliary hardware, including a first electronically controlled on-off valve Va1, a second electronically controlled on-off valve Va2, and a third three-way shunt valve Va3, is added to the air path of the fuel cell system. When the fuel cell is in a normal operating state, the second electronically controlled on-off valve Va2 is opened, the first electronically controlled on-off valve Va1 is closed, and the third three-way shunt valve Va3 is in a state where the main path is open and the branch path is closed. When the fuel cell is in an abnormal operating state (such as performance degradation, low single cell, abnormal impedance, etc.), the opening and closing states of the first electronically controlled on-off valve Va1, the second electronically controlled on-off valve Va2, and the third three-way shunt valve Va3 are determined by detecting corresponding data. By changing the temperature, flow rate, humidity, etc. of the gas in the air path and combining the operation method of cathode under-aeration, the purpose of online recovery of the fuel cell stack is achieved, thereby reducing the waste of human and material resources caused by disassembling the stack for offline performance recovery.

[0030] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A fuel cell performance online recovery device, characterized in that: include: The air pump, intercooler, electric control on-off valve Va2, humidifier, fuel cell system, three-way diverter valve Va3, and throttle are connected in sequence. A three-way interface is set between the intercooler and the humidifier, and is connected to an electric control on-off valve Va1, which is connected to the intake pipeline through the three-way interface between the humidifier and the fuel cell stack. The branch outlet of the three-way diverter valve is connected to an air exhaust and introduced into the atmosphere.

2. The fuel cell performance online recovery device according to claim 1, characterized in that: When the fuel cell system does not give a corresponding valve opening instruction, Va1 is in a closed state, and Va3 is in a main circuit open and branch circuit closed state.

3. A method for online recovery of fuel cell performance, characterized in that: Based on the fuel cell performance online recovery device according to claim 1 or 2, the method comprises: When the fuel cell system starts running, the CVM monitors the voltage of the fuel cell cell in real time and the impedance detector detects the impedance value of the entire fuel cell stack in real time to comprehensively judge the performance status of the stack and the internal dryness and humidity status. By opening and closing the electronically controlled on-off valve Va1 and the electronically controlled on-off valve Va2, the fuel cell performance is restored online by adjusting the dryness and humidity changes in the air intake path and the cathode air shortage method.

4. A fuel cell performance online recovery method according to claim 3, characterized in that: The method further comprises: During the operation of the fuel cell system, if the fuel cell stack performance decays due to changes in internal dryness and humidity, the three-way diverter valve is adjusted to change the amount of air entering the humidifier, thereby adjusting the intake humidity so that the fuel cell operates within the optimal humidity range.

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