Hydrogen fuel cell cold start system and method with compressed air coupled with waste heat energy storage

Abstract

The application provides a hydrogen fuel cell cold starting system with compressed air and waste heat coupling energy storage, in which a compressed air storage tank, an air heating pipeline and a humidifier are connected to form a heated air supply branch which is communicated with an air inlet of an electric pile; a hydrogen storage bottle and a hydrogen heating pipeline are connected to form a heated hydrogen supply branch which is communicated with a hydrogen inlet of the electric pile; a cooling liquid outlet of the electric pile and a cooling liquid heat exchange pipeline have a communication state, an outlet of the cooling liquid heat exchange pipeline is communicated with a cooling liquid inlet of the electric pile through a cooling liquid preheating branch, a cooling liquid circulating pump is arranged on the cooling liquid preheating branch, the cooling liquid heat exchange pipeline is heat exchanged with a heat storage medium, and is used for storing waste heat of the electric pile cooling liquid in the heat storage medium or preheating the cooling liquid under a cold starting condition. The cathode air heating supply, the anode hydrogen heating supply and the cooling liquid preheating electric pile under the cold starting condition are realized, and the system has the advantages of low energy consumption and fast starting response under the cold starting condition.

Description

Technical Field

[0001] This invention relates to the field of hydrogen fuel cell technology, and in particular to a cold start system and method for hydrogen fuel cells that couples compressed air with waste heat for energy storage. Background Technology

[0002] Driven by the global energy transition and the "dual carbon" goal, hydrogen-powered transportation, as a zero-emission, high-energy-density sustainable transportation solution, is of crucial significance for reducing carbon emissions in the transportation sector and alleviating dependence on fossil fuels. Hydrogen fuel cells convert hydrogen and oxygen into electricity through an electrochemical reaction, producing only water throughout the process. Combining high efficiency and environmental friendliness, it is the core power technology for hydrogen-powered transportation and is expected to achieve large-scale application in commercial vehicles, heavy trucks, and rail transit, driving a profound transformation of the transportation industry towards low-carbon and clean energy.

[0003] Cold start-up of hydrogen fuel cells in low-temperature environments faces severe challenges. When the ambient temperature drops below freezing, moisture inside the fuel cell stack rapidly freezes, severely impacting the stack in terms of both performance loss and structural damage. Performance-wise, the ice layer adheres to the surface of the proton exchange membrane, blocking hydrogen ion conduction channels and significantly reducing the membrane's ion conduction efficiency, thus weakening the stack's power output. Simultaneously, the catalyst surface is covered by ice, preventing active sites from fully contacting reactants, significantly reducing the electrochemical reaction rate and hindering the stack's ability to generate electricity normally. Structurally, the approximately 9% volume expansion of water upon freezing exerts strong compressive forces on the stack's internal precision structures, causing mechanical damage such as bipolar plate deformation and seal failure. In extreme cases, this can even trigger a short circuit, directly threatening the stack's safe and stable operation and lifespan.

[0004] To address this challenge, traditional cold-start technology employs a strategy of "high-pressure purging + external heating." On one hand, before shutting down the fuel cell stack, a high-pressure air environment is quickly established at the cathode using a starting air compressor. This high-pressure airflow purges the interior of the stack to remove excess moisture. On the other hand, during the cold start process, the supply of air to the cathode via the air compressor and the use of waste heat from the air compressor to preheat the air supply lines both consume significant amounts of electricity. Furthermore, using high-power electric heating equipment (such as a PTC heater) to comprehensively heat the coolant, air, hydrogen, and the fuel cell stack itself also requires substantial energy. The applicant has identified at least the following technical problems with existing technologies: The significant shortcomings of this approach can be summarized as follows: the air compressor consumes a large amount of power, severely depleting onboard energy; the high-power electric heater not only has high energy consumption itself, but also exhibits significant thermal inertia during the heating process, resulting in a long system start-up response time, which cannot meet the immediate and rapid start-up requirements of hydrogen-powered transportation and other fields.

[0005] Therefore, traditional cold start methods suffer from high energy consumption and slow response. Developing low-energy-consumption, fast-response cold start technology is the core direction to overcome the bottleneck of low-temperature applications of hydrogen fuel cells. Summary of the Invention

[0006] The purpose of this invention is to provide a cold start system and method for hydrogen fuel cells that couples compressed air with waste heat for energy storage, in order to solve the technical problems of high energy consumption and slow response in traditional cold start methods. The various technical effects of the preferred solutions among the many technical solutions provided by this invention are detailed below.

[0007] To achieve the above objectives, the present invention provides the following technical solution:

[0008] The cold start system for hydrogen fuel cells with compressed air and waste heat coupled for energy storage provided by this invention includes a compressed air storage tank, a heat exchanger, a humidifier, and a hydrogen storage cylinder, wherein:

[0009] The heat storage heat exchanger includes a shell, a coolant heat exchange pipeline, an air heating pipeline, a hydrogen heating pipeline, and a heat storage medium located inside the shell.

[0010] The compressed air storage tank, the air heating pipeline, and the humidifier are connected to form a heated air supply branch, which is connected to the air inlet of the fuel cell stack.

[0011] The hydrogen storage cylinder and the hydrogen heating pipeline are connected to form a heated hydrogen supply branch, which is connected to the hydrogen inlet of the fuel cell stack.

[0012] The coolant outlet of the fuel cell stack is connected to the coolant heat exchange pipeline. The outlet of the coolant heat exchange pipeline is connected to the coolant inlet of the fuel cell stack through a coolant preheating branch. A coolant circulation pump is installed on the coolant preheating branch. The coolant heat exchange pipeline exchanges heat with the heat storage medium to store the residual heat of the fuel cell stack coolant in the heat storage medium or to preheat the coolant under cold start conditions.

[0013] Preferably, the hydrogen fuel cell cold start system with compressed air and waste heat coupled energy storage further includes an intercooler and an air cooler, wherein:

[0014] The other outlet of the coolant heat exchange pipeline is connected to the intercooler, the air cooler, and the coolant circulation pump to form a coolant heat storage and dissipation branch. The coolant heat storage and dissipation branch is connected to the coolant inlet of the fuel cell stack.

[0015] Preferably, the hydrogen fuel cell cold start system with compressed air and waste heat coupled energy storage further includes an air compressor, a cathode main control valve, and an intercooler, wherein:

[0016] The air compressor, the intercooler, and the humidifier are connected to form a cathode-side air supply main circuit, which is connected to the air inlet of the fuel cell stack.

[0017] A cathode main control valve is provided between the air compressor and the intercooler. The cathode main control valve is used to control whether the main air supply line on the cathode side is open.

[0018] Preferably, the air compressor is connected to the compressed air storage tank to form a compressed air energy storage branch, and an air compressor outlet bypass valve is provided between the air compressor and the compressed air storage tank to control whether the compressed air energy storage branch is open.

[0019] Preferably, the hydrogen storage cylinder and the hydrogen inlet of the fuel cell stack are connected via a main hydrogen supply line;

[0020] The hydrogen supply branch is equipped with a hydrogen supply branch inlet valve and a hydrogen supply branch outlet valve, which are located at the inlet section and outlet section of the hydrogen heating pipeline, respectively.

[0021] An anode main control valve and a hydrogen storage cylinder outlet valve are sequentially installed along the hydrogen flow direction on the main hydrogen supply line. The inlet and outlet sections of the hydrogen heating pipeline are respectively connected to the upstream and downstream sections of the hydrogen storage cylinder outlet valve.

[0022] Preferably, an intercooler inlet valve is provided on the pipeline between the coolant heat exchange pipeline and the intercooler, and an air cooler outlet valve is provided on the pipeline between the air cooler and the coolant circulation pump.

[0023] Preferably, a compressed air storage tank outlet valve is provided between the compressed air storage tank and the air heating pipeline to control whether the heated air supply branch is connected;

[0024] The inlet section of the coolant heat exchange pipeline is equipped with a coolant inlet valve to control whether the coolant outlet of the fuel cell stack is connected to the coolant heat exchange pipeline.

[0025] A coolant outlet valve is installed on the coolant preheating branch to control whether the coolant heat exchange pipeline is connected to the coolant inlet of the fuel cell stack.

[0026] Preferably, the shell periphery of the heat storage heat exchanger is filled with heat insulation material, and an electric heat tracing assembly is fixed on the shell side wall of the heat storage heat exchanger for heating the heat storage medium.

[0027] This invention provides a cold start method for hydrogen fuel cells using compressed air and waste heat coupled energy storage. The method, employing the aforementioned compressed air and waste heat coupled energy storage hydrogen fuel cell cold start system, includes:

[0028] Under normal operating conditions of the fuel cell stack: the coolant outlet of the fuel cell stack is connected to the coolant heat exchange pipeline, the coolant carries the heat of the fuel cell stack and exchanges heat with the heat storage medium in the coolant heat exchange pipeline, and the residual heat of the coolant is stored in the heat storage medium.

[0029] Under cold start conditions of fuel cell stack:

[0030] On the cathode side, air from the compressed air tank flows into the air heating pipeline to exchange heat with the heat storage medium, and heated air is supplied to the air inlet of the fuel cell stack through the heated air supply branch.

[0031] On the anode side, hydrogen gas in the hydrogen storage cylinder flows into the hydrogen heating pipeline to exchange heat with the heat storage medium, and heated hydrogen gas is supplied to the hydrogen inlet of the fuel cell stack through the heated hydrogen supply branch.

[0032] Under the action of the coolant circulation pump, the coolant flows into the coolant heat exchange pipeline to exchange heat with the heat storage medium. After the coolant is heated, it flows back to the coolant inlet of the fuel cell stack through the coolant preheating branch, thereby preheating the fuel cell stack.

[0033] Preferably, the hydrogen fuel cell cold start system with compressed air and waste heat coupled energy storage further includes an air compressor, the shell peripheral wall of the heat storage heat exchanger is filled with heat insulation material, and an electric heat tracing component is fixed on the shell side wall of the heat storage heat exchanger.

[0034] The method also includes:

[0035] Under normal operating conditions of the fuel cell stack, the air compressor inputs compressed air into the compressed air storage tank, and the compressed air is stored in the compressed air storage tank.

[0036] When the fuel cell stack is shut down for an extended period in an extremely low temperature environment, the electric heat tracing component is used to heat the heat storage medium inside the heat storage heat exchanger, thereby maintaining the temperature of the heat storage medium at a set temperature.

[0037] The cold start system and method for hydrogen fuel cells with compressed air and waste heat coupled energy storage provided by this invention have the following advantages compared with the prior art:

[0038] Under normal operating conditions of the fuel cell stack, the residual heat of the coolant is stored in the heat storage medium. Under cold start conditions, on the cathode side, air in the compressed air tank exchanges heat with the heat storage medium through the air heating pipeline, and after being heated, flows into the air inlet of the fuel cell stack. On the anode side, hydrogen in the hydrogen storage tank exchanges heat with the heat storage medium through the hydrogen heating pipeline, and after being heated, flows into the hydrogen inlet of the fuel cell stack. Under the action of the coolant circulation pump, the coolant flows into the coolant heat exchange pipeline to exchange heat with the heat storage medium, and after being heated, it preheats the fuel cell stack. This system does not require starting the compressor or using high-power, high-energy-consuming electric heating equipment to heat the coolant, air, hydrogen, and fuel cell stack itself. It makes full use of the compressed air energy storage and the fuel cell stack residual heat energy storage to achieve cathode air heating supply, anode hydrogen heating supply, and coolant heating of the fuel cell stack under cold start conditions. It has the advantages of low cold start energy consumption and fast start-up response, overcoming the limitations of traditional cold start systems such as high air compressor power consumption, high electric heating system energy consumption, and slow system start-up response. Attached Figure Description

[0039] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the 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.

[0040] Figure 1 This is a schematic diagram of a cold start system for a hydrogen fuel cell based on compressed air and waste heat coupled energy storage.

[0041] Figure 2 This is a schematic diagram of a thermal storage heat exchanger.

[0042] Figure 3 Schematic diagram of the main air supply circuit on the cathode side;

[0043] Figure 4 This is a schematic diagram of the compressed air energy storage branch.

[0044] Figure 5 This is a schematic diagram of the cathode-side heating gas supply structure under cold start conditions.

[0045] Figure 6 This is a schematic diagram of the hydrogen supply structure for anode-side heating under cold start conditions;

[0046] Figure 7 This is a schematic diagram of the connection structure between the coolant heat storage and heat dissipation branch and the fuel cell stack.

[0047] Figure 8 This is a schematic diagram of the coolant preheating branch and the fuel cell stack under cold start conditions.

[0048] In the diagram: 1. Air compressor; 2. Compressed air storage tank; 3. Thermal storage heat exchanger; 4. Intercooler; 5. Air cooler; 6. Coolant circulation pump; 7. Humidifier; 8. Battery pack; 9. Hydrogen storage cylinder; 10. Air compressor outlet bypass valve; 11. Cathode main control valve; 12. Compressed air storage tank outlet valve; 13. Anode main control valve; 14. Hydrogen storage cylinder outlet valve; 15. Hydrogen supply branch inlet valve; 16. Hydrogen supply branch outlet valve; 17. Air cooler outlet valve; 18. Coolant inlet valve; 19. Coolant outlet valve; 20. Intercooler inlet valve; 31. Coolant heat exchange pipeline; 32. Air heating pipeline; 33. Hydrogen heating pipeline; 34. Heat storage medium; 35. Electric heat tracing assembly; 36. Thermal insulation material; 40. Fuel cell stack. Detailed Implementation

[0049] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be described in detail below. Obviously, the described embodiments are merely some embodiments of this invention, and not all embodiments. Based on the embodiments of this invention, all other implementation methods obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0050] In the description of this invention, it should be understood that the terms "center," "length," "width," "height," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," and "side," etc., indicating orientation or positional relationships, are based on the orientation or positional relationships shown in the accompanying drawings and are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0051] This invention provides a cold start system and method for hydrogen fuel cells that couples compressed air with waste heat for energy storage. It eliminates the need to start a compressor or use high-power, high-energy-consumption electric heating equipment to heat the coolant, air, hydrogen, and fuel cell stack. It fully utilizes compressed air energy storage, fuel cell stack waste heat energy storage, and low-power electric heat tracing to simultaneously achieve cathode air heating supply, anode hydrogen heating supply, and coolant heating of the fuel cell stack under cold start conditions. It has the advantages of low cold start energy consumption and fast start-up response.

[0052] The following is combined Figures 1-8 The technical solution provided by this invention will be described in more detail below.

[0053] Example 1:

[0054] See Figures 1-8As shown, the hydrogen fuel cell cold start system with compressed air and waste heat coupled energy storage provided by the present invention includes a compressed air storage tank 2, a heat exchanger 3, a humidifier 7, and a hydrogen storage cylinder 9. The heat exchanger 3 includes a shell, a coolant heat exchange pipeline 31, an air heating pipeline 32, a hydrogen heating pipeline 33 located within the shell, and a heat storage medium 34. A heated air supply branch is formed between the compressed air storage tank 2, the air heating pipeline 32, and the humidifier 7, and this heated air supply branch is connected to the air inlet of the fuel cell stack 40. The hydrogen storage cylinder... 9. The hydrogen heating pipeline 33 is connected to form a hydrogen heating supply branch, which is connected to the hydrogen inlet of the fuel cell stack; the coolant outlet of the fuel cell stack is connected to the coolant heat exchange pipeline 31, and the outlet of the coolant heat exchange pipeline 31 is connected to the coolant inlet of the fuel cell stack through the coolant preheating branch. A coolant circulation pump 6 is installed on the coolant preheating branch. The coolant heat exchange pipeline 31 exchanges heat with the heat storage medium 34 to store the residual heat of the fuel cell stack coolant in the heat storage medium 34, or to preheat the coolant under cold start conditions.

[0055] See Figure 2 As shown, the air heating pipe 32 and the hydrogen heating pipe 33 are located on opposite sides of the shell of the heat storage heat exchanger 3, and the coolant heat exchange pipe 31 passes through the shell.

[0056] See Figure 6 As shown, under normal operating conditions of the fuel cell stack: the coolant outlet of the fuel cell stack is connected to the coolant heat exchange pipeline 31. The coolant carries the heat of the fuel cell stack 40 and exchanges heat with the heat storage medium 34 in the coolant heat exchange pipeline 31, storing the residual heat of the coolant in the heat storage medium 34.

[0057] See Figure 1 and Figure 5 As shown, a compressed air tank outlet valve 12 is installed between the compressed air tank 2 and the air heating pipeline 32 to control whether the heating air supply branch is connected.

[0058] During the cold start operation after the fuel cell stack is shut down, the compressed air stored in the compressed air tank 2 enters the air heating pipe 32 inside the thermal storage heat exchanger 3 through the compressed air tank outlet valve 12. After exchanging heat with the heat storage medium 34 on the outside of the pipe and being heated, the air is sent to the humidifier 7 for humidification, and then supplied to the cathode side of the fuel cell stack 40. This cold start process uses the compressed air in the compressed air tank 2 for air supply without starting the air compressor, thereby avoiding the cold start energy consumption generated by the air compressor in the traditional cold start process.

[0059] As an alternative implementation, see [link to implementation details]. Figure 1 , Figure 6The hydrogen storage cylinder 9 is connected to the hydrogen inlet of the fuel cell stack via a main hydrogen supply line. A hydrogen supply branch inlet valve 15 and a hydrogen supply branch outlet valve 16 are installed on the hydrogen supply branch, which are located at the inlet and outlet sections of the hydrogen heating pipeline 33, respectively. An anode main control valve 13 and a hydrogen storage cylinder outlet valve 14 are installed sequentially along the hydrogen flow direction on the main hydrogen supply line. The inlet and outlet sections of the hydrogen heating pipeline 33 are connected to the upstream and downstream sections of the hydrogen storage cylinder outlet valve 14, respectively.

[0060] During the cold start operation after the fuel cell stack is shut down, the high-pressure hydrogen in the hydrogen storage cylinder 9 enters the hydrogen heating pipeline 33 of the thermal storage heat exchanger 3 through the anode main control valve 13 and the hydrogen supply branch inlet valve 15. After exchanging heat with the heat storage medium 34 outside the pipeline and being heated, the hydrogen is then input to the anode side of the fuel cell stack 40.

[0061] See Figure 8 The inlet section of the coolant heat exchange pipeline 31 is equipped with a coolant inlet valve 18, which is used to control whether the coolant outlet of the fuel cell stack is connected to the coolant heat exchange pipeline 31; a coolant outlet valve 19 is installed on the coolant preheating branch, which is used to control whether the coolant heat exchange pipeline 31 is connected to the coolant inlet of the fuel cell stack.

[0062] See Figure 1 , Figure 8 The coolant circulation pump 6, coolant inlet valve 18, coolant heat exchange pipeline 31, and coolant outlet valve 19 constitute the coolant preheating branch. Under cold start conditions, the coolant, driven by the coolant circulation pump 6, flows through the coolant inlet valve 18, the heat storage heat exchanger 3, and the coolant outlet valve 19. In the heat storage heat exchanger 3, the coolant absorbs the heat stored in the heat storage medium 34 through the heat exchange pipeline 31, and then the coolant heats up, transferring the heat to the fuel cell stack to preheat it.

[0063] See Figures 1-7 As shown, under the cold start condition of the fuel cell stack, the coolant heat exchange pipeline 31, the air heating pipeline 32, and the hydrogen heating pipeline 33 can all exchange heat with the heat storage medium 34, thereby heating the fuel cell stack, the air entering the fuel cell stack, and the hydrogen entering the fuel cell stack respectively. This enables the fuel cell stack to achieve low-energy consumption and rapid cold start without starting the air compressor or a high-power, high-energy-consumption heating device.

[0064] As an alternative implementation, see [link to implementation details]. Figure 1 As shown, the hydrogen fuel cell cold start system with compressed air and waste heat coupled energy storage also includes an intercooler 4 and an air cooler 5. The other outlet of the coolant heat exchange pipeline 31 is connected to the intercooler 4, the air cooler 5, and the coolant circulation pump 6 to form a coolant heat storage and heat dissipation branch. The coolant heat storage and heat dissipation branch is connected to the coolant inlet of the fuel cell stack.

[0065] See Figure 1 and Figure 6 As shown, an intercooler inlet valve 20 is installed on the pipeline between the coolant heat exchange pipeline 31 and the intercooler 4, and an air cooler outlet valve 17 is installed on the pipeline between the air cooler 5 and the coolant circulation pump 6.

[0066] Under normal operating conditions of the fuel cell stack: the coolant outlet of the stack is connected to the coolant heat exchange pipe 31. The coolant, carrying heat from the stack, exchanges heat with the heat storage medium 34 in the coolant heat exchange pipe 31, storing the residual heat of the coolant in the heat storage medium 34. In this process, see [link to relevant documentation]. Figure 1 and Figure 6 As shown, under normal operating conditions of the fuel cell stack, the coolant circulation pump 6 drives the coolant to absorb the heat generated by the electrochemical reaction within the fuel cell stack. The coolant then exchanges heat with the heat storage medium 34 outside the heat exchange tube in the coolant heat exchange pipe 31 of the heat storage heat exchanger 3, releasing the heat and storing it in the heat storage medium 34. Subsequently, the coolant flows sequentially through the intercooler inlet valve 20, the intercooler 4, the air cooler 5, and the air cooler outlet valve 17 to complete the coolant heat storage and dissipation cycle, before flowing back into the fuel cell stack. No coolant loss occurs during this process.

[0067] As an alternative implementation, see [link to implementation details]. Figure 1 and Figure 3 As shown, the cold start system for a hydrogen fuel cell with compressed air and waste heat coupled energy storage also includes an air compressor 1, a cathode main control valve 11, and an intercooler 4. The air compressor 1, intercooler 4, and humidifier 7 are connected to form a cathode-side air supply main circuit, which is connected to the air inlet of the fuel cell stack. A cathode main control valve 11 is installed between the air compressor 1 and the intercooler 4, and this valve is used to control whether the cathode-side air supply main circuit is open. (See also...) Figure 1 and Figure 4 As shown, the air compressor 1 is connected to the compressed air storage tank 2 to form a compressed air energy storage branch. An air compressor outlet bypass valve 10 is installed between the air compressor 1 and the compressed air storage tank 2 to control whether the compressed air energy storage branch is open.

[0068] like Figure 3 As shown, the air compressor 1, the cathode main control valve 11, and the intercooler 4 constitute the main air supply circuit on the cathode side; the air compressor 1, the air compressor outlet bypass valve 10, and the compressed air storage tank 2 constitute the compressed air energy storage branch circuit; under normal operating conditions of the fuel cell stack, the air compressor 1 inputs and stores compressed air into the compressed air storage tank 2 through the air compressor outlet bypass valve 10.

[0069] As an optional implementation, the peripheral wall of the shell of the heat storage heat exchanger 3 is filled with heat insulation material 36, and an electric heat tracing assembly 35 is fixed on the side wall of the shell of the heat storage heat exchanger 3 for heating the heat storage medium.

[0070] Driven by the battery pack 8, the electric heat tracing component 35 provides low-power heat tracing and temperature maintenance for the outer surface of the thermal storage heat exchanger 3, supplementing the heat loss of the thermal storage medium 34 through the outer surface of the thermal storage heat exchanger 3 to the environment. The thermal insulation material 36 is used to insulate the thermal storage heat exchanger to reduce the heat loss of the thermal storage heat exchanger 3 through its outer surface to the surrounding environment. This combination of waste heat storage, low-power heat tracing and temperature maintenance and thermal insulation avoids the power consumption of high-power heating of the coolant and the fuel cell stack body under traditional cold start conditions, and has the advantages of low heat tracing power and low cold start energy consumption.

[0071] Example 2:

[0072] See Figures 1-8 As shown, this embodiment provides a cold start method for hydrogen fuel cells with compressed air and waste heat coupled energy storage. Using the hydrogen fuel cell cold start system with compressed air and waste heat coupled energy storage of Embodiment 1, the method includes: under normal operating conditions of the fuel cell stack: the coolant outlet of the fuel cell stack is connected to the coolant heat exchange pipeline 31, the coolant carries the heat of the fuel cell stack and exchanges heat with the heat storage medium 34 in the coolant heat exchange pipeline 31, and the waste heat of the coolant is stored in the heat storage medium 34.

[0073] During the cold start operation of the fuel cell stack: On the cathode side, air from the compressed air tank 2 flows into the air heating pipe 32 to exchange heat with the heat storage medium 34, and heated air is supplied to the air inlet of the fuel cell stack through the heated air supply branch; On the anode side, hydrogen from the hydrogen storage cylinder 9 flows into the hydrogen heating pipe 33 to exchange heat with the heat storage medium 34, and heated hydrogen is supplied to the hydrogen inlet of the fuel cell stack through the heated hydrogen supply branch; Under the action of the coolant circulation pump 6, coolant flows into the coolant heat exchange pipe 31 to exchange heat with the heat storage medium 34, and after the coolant is heated, it flows back to the coolant inlet of the fuel cell stack through the coolant preheating branch, thereby preheating the fuel cell stack.

[0074] Specifically, this embodiment provides a cold start method for hydrogen fuel cells using compressed air and waste heat coupled energy storage. First, under normal operating conditions of the fuel cell stack, the method involves... Figure 4 The compressed air energy storage branch shown stores compressed air in compressed air storage tank 2, and then... Figure 7 The coolant heat storage and heat dissipation branch shown stores the coolant in the heat storage heat exchanger 3, which carries the heat generated inside the fuel cell stack.

[0075] Secondly, under the cold start condition of the fuel cell stack, by means of... Figure 5 , Figure 6 and Figure 8 The heating air supply branch, heating hydrogen supply branch, and coolant preheating branch shown simultaneously heat the cathode-side air, anode-side hydrogen, coolant, and fuel cell stack; when the fuel cell stack is shut down for extended periods in extremely low-temperature environments, it utilizes... Figure 2 The low-power electric heat tracing component 35 shown provides heat tracing and temperature maintenance for the thermal storage heat exchanger 3, thereby enabling low-energy, rapid cold start of the fuel cell stack without the need to start the air compressor or a high-power, high-energy-consumption heating device.

[0076] The specific steps include: First, on the cathode gas supply side of the fuel cell stack, a compressed air energy storage bypass is set through the outlet of the air compressor 1. The outlet valve of the compressed air storage tank is kept closed, and the air compressor outlet bypass valve 10 is opened to input and store high-pressure air into the compressed air storage tank 2. At the same time, the coolant, driven by the coolant circulation pump 6, enters the fuel cell stack to absorb the heat generated in the fuel cell stack and then enters the coolant heat exchange pipeline 31 in the heat storage heat exchanger through the coolant inlet valve 18. The coolant exchanges heat with the heat storage medium 34 and stores the heat in the heat storage heat exchanger 3. Then, it flows sequentially through the intercooler inlet valve 20, the intercooler 4, the air cooler 5, and the air cooler outlet valve 17 to complete the coolant heat storage and heat dissipation cycle.

[0077] Secondly, during the low-temperature cold start condition after the fuel cell stack is shut down, keep the air compressor outlet bypass valve 10, cathode main control valve 11, intercooler inlet valve 20, air cooler outlet valve 17, and hydrogen storage cylinder outlet valve 14 closed, and open the compressed air storage tank outlet valve 12, coolant inlet valve 18, coolant outlet valve 19, hydrogen supply branch inlet valve 15, and hydrogen supply branch outlet valve 16. On the cathode side, the high-pressure air in the compressed air storage tank 2 enters the air heating pipe 32 in the heat storage heat exchanger through the compressed air storage tank outlet valve 12, exchanges heat with the heat storage medium 34, and then enters the humidification system. The device 7 humidifies and supplies hot air to the cathode of the fuel cell stack. On the anode side, hydrogen in the hydrogen storage tank 9 enters the hydrogen heating pipe 33 in the thermal storage heat exchanger through the anode main control valve 13 and the hydrogen supply branch inlet valve 15 to exchange heat with the thermal storage medium 34 and raise its temperature. It then supplies hot hydrogen to the anode of the fuel cell stack through the hydrogen supply branch outlet valve 16. On the coolant preheating branch, driven by the coolant circulation pump 6, the coolant enters the coolant heat exchange pipe 31 of the thermal storage heat exchanger through the coolant inlet valve 18 to exchange heat with the thermal storage medium 34 and raise its temperature. Then, it enters the fuel cell stack body through the coolant outlet valve 19 to preheat the fuel cell stack.

[0078] The hydrogen fuel cell cold start method proposed in this invention, based on compressed air and waste heat coupled energy storage, eliminates the need to start a compressor or use high-power, high-energy-consumption electric heating equipment to heat the coolant, air, hydrogen, and fuel cell stack. It fully utilizes compressed air energy storage, fuel cell stack waste heat energy storage, and low-power electric heat tracing to simultaneously achieve cathode air heating supply, anode hydrogen heating supply, and coolant heating of the fuel cell stack under cold start conditions. It has the advantages of low cold start energy consumption and fast start response, breaking through the limitations of traditional cold start systems such as high air compressor power consumption, high electric heating system energy consumption, and slow system start response. It has broad application prospects in the field of low-energy-consumption and rapid cold start of hydrogen fuel cells.

[0079] The specific features, structures, or characteristics described in this specification may be combined in any suitable manner in one or more embodiments or examples.

[0080] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0081] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A cold start system for a hydrogen fuel cell coupled with compressed air and waste heat energy storage, characterized in that, Includes a compressed air storage tank (2), a heat exchanger (3), a humidifier (7), and a hydrogen storage cylinder (9), wherein: The heat storage heat exchanger (3) includes a shell, a coolant heat exchange pipeline (31) located in the shell, an air heating pipeline (32), a hydrogen heating pipeline (33), and a heat storage medium (34). The compressed air storage tank (2), the air heating pipeline (32), and the humidifier (7) are connected to form a heated air supply branch, which is connected to the air inlet of the fuel cell stack. The hydrogen storage cylinder (9) and the hydrogen heating pipeline (33) are connected to form a heated hydrogen supply branch, which is connected to the hydrogen inlet of the fuel cell stack. The coolant outlet of the fuel cell stack is connected to the coolant heat exchange pipeline (31). The outlet of the coolant heat exchange pipeline (31) is connected to the coolant inlet of the fuel cell stack through a coolant preheating branch. A coolant circulation pump (6) is provided on the coolant preheating branch. The coolant heat exchange pipeline (31) exchanges heat with the heat storage medium (34) to store the residual heat of the fuel cell stack coolant in the heat storage medium (34) or to preheat the coolant under cold start conditions. Under the cold start condition of the fuel cell stack, the coolant heat exchange pipeline (31), the air heating pipeline (32), and the hydrogen heating pipeline (33) can all exchange heat with the heat storage medium (34) to heat the fuel cell stack, the air entering the fuel cell stack, and the hydrogen entering the fuel cell stack, respectively. The hydrogen fuel cell cold start system with compressed air and waste heat coupled energy storage also includes an air compressor (1), a cathode main control valve (11), and an intercooler (4), wherein: The air compressor (1), the intercooler (4), and the humidifier (7) are connected to form a cathode-side air supply main circuit, which is connected to the air inlet of the fuel cell stack. A cathode main control valve (11) is provided between the air compressor (1) and the intercooler (4). The cathode main control valve (11) is used to control whether the main air supply line on the cathode side is open. The air compressor (1) is connected to the compressed air storage tank (2) to form a compressed air energy storage branch. An air compressor outlet bypass valve (10) is provided between the air compressor (1) and the compressed air storage tank (2) to control whether the compressed air energy storage branch is open.

2. The hydrogen fuel cell cold start system with compressed air and waste heat coupled energy storage according to claim 1, characterized in that, The compressed air and waste heat coupled energy storage hydrogen fuel cell cold start system also includes an air cooler (5), wherein: The other outlet of the coolant heat exchange pipeline (31) is connected to the intercooler (4), the air cooler (5), and the coolant circulation pump (6) to form a coolant heat storage and heat dissipation branch. The coolant heat storage and heat dissipation branch is connected to the coolant inlet of the fuel cell stack.

3. The hydrogen fuel cell cold start system with compressed air and waste heat coupled energy storage according to claim 1, characterized in that, The hydrogen storage cylinder (9) is connected to the hydrogen inlet of the fuel cell stack via a main hydrogen supply line; The hydrogen supply branch is equipped with a hydrogen supply branch inlet valve (15) and a hydrogen supply branch outlet valve (16), which are located in the inlet section and outlet section of the hydrogen heating pipeline (33), respectively. The main hydrogen supply line is provided with an anode main control valve (13) and a hydrogen storage cylinder outlet valve (14) in sequence along the hydrogen flow direction. The inlet and outlet sections of the hydrogen heating pipeline (33) are respectively connected to the upstream and downstream sections of the hydrogen storage cylinder outlet valve (14).

4. The hydrogen fuel cell cold start system with compressed air and waste heat coupled energy storage according to claim 2, characterized in that, An intercooler inlet valve (20) is provided on the pipeline between the coolant heat exchange pipeline (31) and the intercooler (4), and an air cooler outlet valve (17) is provided on the pipeline between the air cooler (5) and the coolant circulation pump (6).

5. The hydrogen fuel cell cold start system with compressed air and waste heat coupled energy storage according to claim 1, characterized in that, A compressed air tank outlet valve (12) is provided between the compressed air tank (2) and the air heating pipeline (32) to control whether the heated air supply branch is connected. The inlet section of the coolant heat exchange pipeline (31) is equipped with a coolant inlet valve (18) to control whether the coolant outlet of the fuel cell stack is connected to the coolant heat exchange pipeline (31). A coolant outlet valve (19) is provided on the coolant preheating branch to control whether the coolant heat exchange pipeline (31) is connected to the coolant inlet of the fuel cell stack.

6. The hydrogen fuel cell cold start system with compressed air and waste heat coupled energy storage according to claim 1, characterized in that, The shell periphery of the heat storage heat exchanger (3) is filled with heat insulation material (36), and an electric heat tracing assembly (35) is fixed on the shell side wall of the heat storage heat exchanger (3) for heating the heat storage medium.

7. A cold start method for a hydrogen fuel cell using compressed air and waste heat coupled energy storage, characterized in that, The method using the hydrogen fuel cell cold start system with compressed air and waste heat coupled energy storage as described in any one of claims 1-6 includes: Under normal operating conditions of the fuel cell stack: the coolant outlet of the fuel cell stack is connected to the coolant heat exchange pipeline (31), the coolant carries the heat of the fuel cell stack and exchanges heat with the heat storage medium (34) in the coolant heat exchange pipeline (31), and the residual heat of the coolant is stored in the heat storage medium (34). Under cold start conditions of fuel cell stack: On the cathode side, the air in the compressed air tank (2) flows into the air heating pipe (32) to exchange heat with the heat storage medium (34), and the heated air is supplied to the air inlet of the fuel cell through the heated air supply branch; On the anode side, hydrogen gas in the hydrogen storage cylinder (9) flows into the hydrogen heating pipeline (33) to exchange heat with the heat storage medium (34), and the heated hydrogen gas is supplied to the hydrogen inlet of the fuel cell through the heated hydrogen gas supply branch; Under the action of the coolant circulation pump (6), the coolant flows into the coolant heat exchange pipeline (31) to exchange heat with the heat storage medium (34). After the coolant is heated, it flows back to the coolant inlet of the fuel cell stack through the coolant preheating branch, thereby preheating the fuel cell stack.

8. The cold start method for hydrogen fuel cells with compressed air and waste heat coupled energy storage according to claim 7, characterized in that, The compressed air and waste heat coupled energy storage hydrogen fuel cell cold start system also includes an air compressor (1), the shell peripheral wall of the heat storage heat exchanger (3) is filled with heat insulation material (36), and an electric heat tracing component (35) is fixed on the shell side wall of the heat storage heat exchanger (3). The method also includes: Under normal operating conditions of the fuel cell stack, the air compressor inputs compressed air into the compressed air storage tank (2) and stores the compressed air in the compressed air storage tank (2); When the fuel cell stack is shut down for a long time in an extremely low temperature environment, the heat storage medium (34) in the heat storage heat exchanger (3) is heated by the electric heat tracing component (35) so that the temperature of the heat storage medium (34) is maintained at the set temperature.

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