Fuel cell system

Abstract

The utility model relates to the technical field of batteries, in particular to a fuel cell system which comprises a fuel gas side and an air side, the fuel gas side comprises an air cooler, a circulating pump and an electric pile, and an outlet of the air cooler is communicated with an inlet of the circulating pump; the air side comprises a main pipeline, an air cooling pipeline and a bypass pipeline, the air cooling pipeline is mixed with the main pipeline to form a first mixing pipeline after being subjected to heat exchange through the air cooler, the first mixing pipeline is mixed with the bypass pipeline to form a second mixing pipeline after being preheated, and the second mixing pipeline is communicated with an inlet of the electric pile. The system is used for regulating and controlling the temperature of the galvanic pile and the inlet of the circulating pump, overtemperature is prevented, part damage is avoided, and the optimal operation performance is maintained.

Description

TECHNICAL FIELD

[0001] The utility model relates to a battery technology field especially relates to a fuel cell system. BACKGROUND

[0002] Fuel cell power generation system is a kind of high-efficiency energy conversion technology that directly converts chemical energy into electrical energy. It is widely used in power supply, transportation and industrial fields, and is concerned due to its high efficiency and environmental friendliness. The working principle of fuel cell is to convert fuel (such as hydrogen or natural gas) and oxidant (usually oxygen) into electrical energy through electrochemical reaction. In this process, fuel cell stack is the core component, which is responsible for electrochemical reaction. However, the performance and life of fuel cell stack are strictly controlled by temperature, and too high or too low temperature will affect its performance. If the temperature is too high, the catalyst in the stack will be deactivated, causing the stack to decay, and if the temperature is too low, the stack cannot reach the best operating state.

[0003] In the existing fuel cell power generation system, US20240213502A1 proposes a fuel cell system including anode exhaust gas transfer and its operating method. The system adopts the technical scheme of recuperation and anode tail gas medium temperature circulation, and through CPOx (partial oxidation reformer) preheating start-up scheme, anode exhaust gas and cathode exhaust gas are supplied to anode tail gas oxidizer (ATO) located in the hot box, which oxidizes anode exhaust gas and generates heat provided to the cell stack. In steady state mode, stop providing anode exhaust gas to ATO or provide a small amount of anode exhaust gas, and provide anode exhaust and cathode exhaust outside the hot box.

[0004] Although the technical scheme proposed by US20240213502A1 can effectively utilize anode exhaust gas to generate heat during startup, the scheme has some technical problems:

[0005] System complexity and cost increase: although the CPOx preheating start-up scheme solves the cold start problem of recuperation architecture, it increases the complexity and cost of the system.

[0006] Fan component selection problem: the system does not consider the fan component selection problem of the system, which affects the overall performance and efficiency of the system.

[0007] Stack and circulating pump inlet temperature control: the system does not consider the solution to the problem of stack and circulating pump inlet temperature over-temperature, which leads to the performance degradation of the stack or the damage of the circulating pump. INVENTION CONTENTS

[0008] In view of the deficiencies of the prior art, the purpose of the embodiments of the utility model is to provide a fuel cell system, which regulates the temperature of the stack and circulating pump inlet by cold air bypass and mixer cooperation, prevents over-temperature, avoids component damage and maintains its best operating performance.

[0009] To achieve the above object, the utility model embodiment provides the following technical scheme:

[0010] A fuel cell system, comprising: a gas side and an air side; the gas side comprises an air cooler, a circulating pump and a stack, the outlet of the air cooler is communicated with the inlet of the circulating pump; the air side comprises a main pipeline, an air cooling pipeline and a bypass pipeline, the air cooling pipeline is mixed with the main pipeline to form a first mixed pipeline after heat exchange through the air cooler, the first mixed pipeline is mixed with the bypass pipeline to form a second mixed pipeline after preheating, and the second mixed pipeline is communicated with the inlet of the stack.

[0011] Optionally, a fan is arranged on each pipeline in the main pipeline, the air cooling pipeline and the bypass pipeline, and the fan provides cold air for each pipeline.

[0012] Optionally, a one-way valve is arranged on each pipeline in the main pipeline, the air cooling pipeline and the bypass pipeline, and the one-way valve is located at the rear side of the fan.

[0013] Optionally, a first mixer and a second mixer are arranged on the main pipeline, the main pipeline and the air cooling pipeline are mixed to form the first mixed pipeline in the first mixer, and the first mixed pipeline and the bypass pipeline form the second mixed pipeline in the second mixer.

[0014] Optionally, an air preheater and a burner are further arranged on the main pipeline, the air preheater is arranged between the first mixer and the second mixer, the air outlet of the stack is communicated with the burner, and the outlet of the burner is communicated with the air preheater.

[0015] Optionally, the gas side comprises a heat exchanger, the gas outlet of the stack is communicated with the heat exchanger, the gas outlet of the heat exchanger is divided into two paths, one path is communicated with the air cooler, and the other path is communicated with the burner.

[0016] Optionally, the gas side further comprises a third mixer, the gas outlet of the circulating pump is communicated with the third mixer, and mixed with inlet fuel to enter the heat exchanger.

[0017] Optionally, the air side comprises an air inlet manifold, a fan is arranged on the air inlet manifold, an air butterfly valve is arranged on each pipeline in the main pipeline, the air cooling pipeline and the bypass pipeline, and a one-way valve is arranged at the rear side of each air butterfly valve.

[0018] Optionally, the air side comprises an air inlet manifold, a fan is arranged on the air inlet manifold, an electric proportional valve is arranged on each pipeline in the main pipeline, the air cooling pipeline and the bypass pipeline, and a one-way valve is arranged at the rear side of each electric proportional valve.

[0019] Optionally, the air side comprises an air inlet manifold, the air inlet manifold is externally connected with compressed air, each of the main pipeline, the air cooling pipeline and the bypass pipeline is provided with a mass flow controller, and each mass flow controller is provided with a check valve at the rear side.

[0020] The one or more technical solutions provided in the embodiments of the present application have at least the following technical effects or advantages:

[0021] 1. The fuel cell system uses the cold air of the bypass pipeline to adjust the inlet temperature of the stack, so that the stack over-temperature is prevented, the stack performance is improved, and the stack attenuation is avoided.

[0022] 2. The fuel cell system provides a flexible air side scheme, which is selected according to system cost, and includes three wind fan joint control, wind fan plus butterfly valve or electric proportional valve, compressed air plus MFC, etc.

[0023] The advantages of the additional aspects of the present application will be given in the following description, some of which will become apparent from the following description, or will be understood through the practice of the present application. BRIEF DESCRIPTION OF DRAWINGS

[0024] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiment or prior art description. Obviously, the drawings in the following description are only some embodiments described in the present application, and for those skilled in the art, other drawings can also be obtained from these drawings without creative labor. In addition, the mutual distance or size is exaggerated for showing the position of each part, and the schematic diagram is only used for illustration.

[0025] Figure 1 is a schematic diagram of the fuel cell system provided by the embodiment 1 of the present application;

[0026] Figure 2 is a schematic diagram of the fuel cell system provided by the embodiment 2 of the present application;

[0027] Figure 3 is a schematic diagram of the fuel cell system provided by the embodiment 3 of the present application;

[0028] In the figure: 01, bypass pipeline; 02, main pipeline; 03, air cooling pipeline; 1, fan; 2, one-way valve; 3, first mixer; 4, air preheater; 5, second mixer; 6, air cooler; 7, circulating pump; 8, third mixer; 9, heat exchanger; 10, electric pile; 11, burner; 12, control valve; 13, mass flow controller; DETAILED DESCRIPTION

[0029] It should be noted that the following detailed description is exemplary and is intended to provide further explanation of the present application. Unless otherwise indicated, all technical and scientific terms used herein have the same meaning as those commonly understood by one of ordinary skill in the art to which the present application belongs. In addition, it should also be understood that when the terms "comprise" and / or "include" are used in this specification, they mean that there is a feature, step, operation, device, component, and / or combination thereof.

[0030] To solve the technical problems mentioned in the background art, the embodiment proposes a fuel cell system. As shown in Figure 1 、 Figure 2 、 Figure 3 , which includes a gas side and an air side; the gas side includes an air cooler 6, a circulating pump 7 and an electric pile 10, the outlet of the air cooler 6 is communicated with the inlet of the circulating pump 7; the air side includes a main pipeline 02, an air cooling pipeline 03 and a bypass pipeline 01, the air cooling pipeline 03 is mixed with the main pipeline 02 to form a first mixed pipeline after heat exchange through the air cooler 6, the first mixed pipeline is mixed with the bypass pipeline 01 to form a second mixed pipeline after preheating, and the second mixed pipeline is communicated with the inlet of the electric pile 10.

[0031] In the working process, the gas from the outlet of the air cooler 6 enters the circulating pump 7 after cooling to ensure that the circulating pump 7 operates within the specified temperature range, avoiding damage to the components caused by high temperature. The air cooling pipeline 03 exchanges heat through the air cooler 6 and is mixed with the main pipeline 02 to form a first mixed pipeline. The first mixed pipeline is further heated by the air preheater 4 and mixed with the bypass pipeline 01 to form a second mixed pipeline. The second mixed pipeline is finally connected to the inlet of the electric pile 10 to provide the electric pile 10 with accurately adjusted air flow and temperature, ensuring that the electric pile 10 operates in the best working state.

[0032] Embodiment one

[0033] As shown in Figure 1 , the main pipeline 02, the air cooling pipeline 03 and the bypass pipeline 01 are each provided with a fan 1, and the fan 1 provides cold air for each pipeline.

[0034] Each pipeline is independently installed with a fan 1 for sucking cold air from the environment. The output of the fan 1 is directly connected to the corresponding pipeline to ensure independent control of the air flow of each pipeline. By providing cold air to each pipeline through independent fans 1, the system can adjust the air flow of each pipeline according to actual needs. For example, the working state of the air cooling pipeline 03 fan 1 can be adjusted according to the amount of cold air required by the air cooler 6, while the bypass pipeline 01 fan 1 can independently provide unheated cold air for mixing with the main air flow. This design improves the flexibility of air flow distribution, enabling the system to efficiently cope with different load conditions.

[0035] Among the main pipeline 02, the air cooling pipeline 03 and the bypass pipeline 01, a one-way valve 2 is arranged on each pipeline, which is located at the rear side of the fan 1.

[0036] The one-way valve 2 is installed immediately after the output of the fan 1 to ensure that cold air can only flow into the pipeline in the specified direction, preventing backflow or gas leakage. The specific form of the one-way valve 2 can be a spring leaf type one-way valve 2 or a check valve, and the optimal solution is selected according to the actual pipeline pressure. This ensures that the system can maintain stability and efficiency when each fan 1 operates independently, and prevents gas backflow between different pipelines due to pressure differences.

[0037] The main pipeline 02 is provided with a first mixer 3 and a second mixer 5, and the main pipeline 02 and the air cooling pipeline 03 are mixed at the first mixer 3 to form a first mixed pipeline, and the first mixed pipeline and the bypass pipeline 01 are mixed at the second mixer 5 to form a second mixed pipeline.

[0038] The first mixer 3 is arranged at the intersection of the main pipeline 02 and the air cooling pipeline 03, and is used to mix the cooled air from the outlet of the air cooler 6 with the main air in the main pipeline 02 to form a first mixed pipeline. The second mixer 5 is arranged at the intersection of the main pipeline 02 and the bypass pipeline 01, and is used to mix the cold air in the bypass pipeline 01 with the air in the first mixed pipeline to form a second mixed pipeline. The internal structure of the two mixers can be designed as a cyclone type or a guide vane type to improve the uniformity of gas mixing.

[0039] The cooled air in the air cooling pipeline 03 after passing through the air cooler 6 is mixed with the air in the main pipeline 02 at the first mixer 3 to preliminarily adjust the air temperature. The first mixed pipeline is warmed up by the air preheater 4, and then the cold air in the bypass pipeline 01 is mixed with it at the second mixer 5 for secondary mixing to further accurately adjust the air temperature to meet the temperature requirements of the inlet of the battery 10. Through the design of double-stage mixers, multi-stage adjustment of air temperature can be realized, avoiding the situation that temperature control is not accurate due to single mixing, which not only adjusts the inlet temperature of the circulating pump 7, but also ensures the stability of the air temperature at the inlet of the battery 10, improving the performance of the battery 10 and prolonging its service life.

[0040] The main air pipeline 02 is also provided with an air preheater 4 and a burner 11, the air preheater 4 is arranged between the first mixer 3 and the second mixer 5, the air outlet of the stack 10 is communicated with the burner 11, and the outlet of the burner 11 is communicated with the air preheater 4.

[0041] The air preheater 4 is installed between the first mixer 3 and the second mixer 5, and is used for heating the air in the first mixing pipeline. The heat source is provided by the burner 11, which provides the required heat for the preheater by burning the anode tail gas. The arrangement of the air preheater 4 makes the inlet air of the stack 10 reach the precise temperature requirement, avoiding the performance reduction of the stack 10 due to the too low inlet air temperature. The high-temperature exhaust gas after combustion is discharged through the exhaust system, while providing heat for the air preheater 4, realizing efficient recovery of heat.

[0042] The gas side includes a heat exchanger 9, the gas outlet of the stack 10 is communicated with the heat exchanger 9, and the gas outlet of the heat exchanger 9 is divided into two ways, one of which is communicated with the air cooler 6, and the other is communicated with the burner 11.

[0043] The inlet of the heat exchanger 9 is connected with the gas outlet of the stack 10, which is used for recovering the heat of high-temperature gas. The outlet of the heat exchanger 9 is divided into two ways, one of which is connected with the air cooler 6 to cool the high-temperature gas, and the other is connected with the burner 11 to support the combustion reaction.

[0044] The heat exchanger 9 uses the waste heat of the gas to preheat the inlet cold fuel, improving the reaction efficiency of the fuel. Part of the high-temperature gas enters the burner 11 to improve the combustion efficiency; another part enters the air cooler 6 to cool down and then returns to the circulating pump 7 to realize closed-loop circulation. Through the design of the heat exchanger 9, the gas heat is effectively recovered, reducing energy waste. The overall energy efficiency of the fuel cell system is improved, and the working state of the circulating pump 7 and the burner 11 is optimized.

[0045] The gas side also includes a third mixer 8, the gas outlet of the circulating pump 7 is communicated with the third mixer 8, and after mixing with the inlet fuel, it enters the heat exchanger 9.

[0046] The third mixer 8 is located between the gas outlet of the circulating pump 7 and the gas inlet of the heat exchanger 9, and its inlet includes two ways, one of which is the return gas from the outlet of the circulating pump 7, and the other is the inlet cold fuel. After the mixed gas is further preheated by the heat exchanger 9, it enters the stack 10 to provide suitable fuel temperature and composition for the stack 10. The introduction of the third mixer 8 can effectively buffer the temperature fluctuation of the circulating pump 7 outlet gas, ensuring that the gas reaches a uniform state before entering the heat exchanger 9. Through the premixing of the mixer, it helps to improve the chemical reaction efficiency of the gas, optimize the fuel utilization rate, and improve the overall efficiency of the system.

[0047] AsFigure 1 The image shows a low-power fuel cell power generation system, and its working principle is as follows:

[0048] The gas-fired side adopts a medium-temperature circulation method. The main working process is as follows: the imported fuel enters the heat exchanger 9 for preheating and then enters the fuel cell stack 10 for power generation. The high-temperature fuel at the outlet of the fuel cell stack 10 enters the heat exchanger 9 and is divided into two streams. One part enters the burner 11 (TGB) for combustion. The high-temperature exhaust gas from the combustion enters the air preheater 4 to heat the cold air in the first mixing pipe before being discharged from the exhaust system. The other part first passes through the air cooler 6 for cooling and then enters the circulation pump 7. The fuel circulated back by the circulation pump 7 is mixed with the imported fuel and then enters the heat exchanger 9.

[0049] The main working process on the air side is as follows: the incoming cold air is divided into three paths, and a three-path fan 1 is used for joint control. A one-way valve 2 is added after each path fan 1. Since this system adopts medium-temperature circulation without condensation, the fuel before the circulation pump 7 needs to be cooled by bypassing the cold air through the circulation pump 7. The air bypass through the air-cooled pipeline 03 controlled by the fan 1 enters the air cooler 6 to cool the fuel before the circulation pump 7. Then it enters the first mixer 3 and mixes with the air in the main pipeline 02. The mixed main pipeline air is heated by the air preheater 4. After being heated, the hot air mixes with the cold air in the bypass pipeline 01 and enters the fuel cell stack 10 after reaching the specified temperature. The hot air at the outlet of the fuel cell stack 10 directly enters the burner 11 to provide oxygen for the combustion reaction.

[0050] The gas and air are heat exchanged in the same flow. The anode exhaust gas self-heating circulation architecture can avoid cross-leakage between fuel and air. Through heat recovery on the anode side of the fuel cell stack 10 and the improvement of system fuel utilization, the system power generation efficiency is maintained at a high level.

[0051] Example 2

[0052] The difference between this embodiment and Embodiment 1 lies in the air-side arrangement.

[0053] The proposed solution is a fan 1 + control valve 12 (air butterfly valve or electric proportional valve). For high-power fuel cell systems, the air-side solution of "fan 1 + air butterfly valve" is adopted, while for low-power fuel cell systems, the air-side solution of "fan 1 + electric proportional valve" is adopted. The specific solution depends on the air flow requirements of the system. The gas-side process is exactly the same as that of the proposed solution.

[0054] like Figure 2 As shown, the air side includes an air intake manifold, on which a fan 1 is installed. In the main pipeline 02, the air-cooled pipeline 03, and the bypass pipeline 01, each pipeline is equipped with an air butterfly valve, and each air butterfly valve is equipped with a one-way valve 2 on its rear side.

[0055] The butterfly valves can be driven manually or automatically, with electric butterfly valves being preferred for remote control and automated adjustment. Each air butterfly valve is equipped with a one-way valve 2 at its rear to prevent backflow and ensure the independence of each pipeline. During system operation, the air butterfly valves adjust the flow rate ratio of each pipeline according to system requirements, achieving precise airflow regulation and ensuring system operational stability.

[0056] In another embodiment, the air side includes an air intake manifold, on which a fan 1 is installed. In the main pipeline 02, the air-cooled pipeline 03, and the bypass pipeline 01, each pipeline is equipped with an electric proportional valve, and each electric proportional valve is equipped with a one-way valve 2 at its rear.

[0057] The butterfly valves on each pipeline have been replaced with electrically operated proportional valves. These valves adjust their opening in real time via electrical control signals, controlling the airflow into each pipeline. Connected to the system control unit, the valves adjust the airflow in each pipeline according to the real-time requirements of the fuel cell stack 10. For example, when the load on the fuel cell stack 10 increases, the system can increase the airflow in the main pipeline 02 while simultaneously reducing the airflow in the bypass pipeline 01 to increase the preheated air ratio.

[0058] Example 3

[0059] The difference between this embodiment and Embodiment 1 lies in the air-side arrangement.

[0060] If the test site has a compressed air supply, the air path adopts a "compressed air + three mass flow controllers (MFCMass Flow Controllers)" scheme. MFCs are used to precisely control the flow rate of gas entering the fuel cell to ensure its efficient and stable operation.

[0061] like Figure 3 As shown, the air side includes an air intake manifold, which is connected to compressed air. In the main pipeline 02, the air-cooled pipeline 03, and the bypass pipeline 01, each pipeline is equipped with a mass flow controller 13, and each mass flow controller 13 is equipped with a one-way valve 2 at its rear.

[0062] The intake manifold connects to an external compressed air supply system, with compressed air serving as the air source for the entire system. A mass flow controller (MFC) is installed on each pipeline to measure and control the flow rate of compressed air entering the pipeline.

[0063] Compressed air is distributed from the intake manifold to the main line 02, the air-cooled line 03, and the bypass line 01. The mass flow controller 13 adjusts the air flow in each line according to the needs of the fuel cell stack 10. The use of MFC can provide extremely high flow control accuracy, making it suitable for fuel cell systems that are sensitive to changes in gas demand.

[0064] In summary, the air side can adopt three schemes: three-way fan 1 joint regulation, fan 1 plus butterfly valve or electric proportional valve, compressed air plus MFC, which can be selected according to the system cost.

[0065] The above describes the specific embodiments of the present application in conjunction with the drawings, but is not a limitation on the scope of protection of the present application, and those skilled in the art should understand that various modifications or variations made by those skilled in the art on the basis of the technical solutions of the present application without creative labor are still within the scope of protection of the present application.

Claims

1. A fuel cell system, characterized in that, The application relates to a fuel cell system. The fuel cell system comprises a fuel side and an air side. The fuel side comprises an air cooler, a circulating pump and a fuel cell stack, and the outlet of the air cooler is communicated with the inlet of the circulating pump. The air side comprises a main pipeline, an air cooling pipeline and a bypass pipeline, the air cooling pipeline is mixed with the main pipeline to form a first mixed pipeline after heat exchange through the air cooler, the first mixed pipeline is mixed with the bypass pipeline to form a second mixed pipeline after preheating, and the second mixed pipeline is communicated with the inlet of the fuel cell stack.

2. The fuel cell system of claim 1, wherein Each pipeline is provided with a fan, and the fan provides cold air for each pipeline.

3. The fuel cell system of claim 2, wherein Each pipeline is provided with a one-way valve, and the one-way valve is located at the rear side of the fan.

4. The fuel cell system of claim 1, wherein, The main pipeline is provided with a first mixer and a second mixer, the main pipeline and the air cooling pipeline are mixed at the first mixer to form the first mixed pipeline, and the first mixed pipeline and the bypass pipeline are mixed at the second mixer to form the second mixed pipeline.

5. The fuel cell system of claim 4, wherein, The main pipeline is further provided with an air preheater and a burner, the air preheater is arranged between the first mixer and the second mixer, the air outlet of the fuel cell stack is communicated with the burner, and the outlet of the burner is communicated with the air preheater.

6. The fuel cell system of claim 5, wherein, The fuel side comprises a heat exchanger, the fuel outlet of the fuel cell stack is communicated with the heat exchanger, the fuel outlet of the heat exchanger is divided into two paths, one path is communicated with the air cooler, and the other path is communicated with the burner.

7. The fuel cell system of claim 6, wherein The fuel side further comprises a third mixer, the fuel outlet of the circulating pump is communicated with the third mixer, and mixed with the inlet fuel to enter the heat exchanger.

8. The fuel cell system of claim 1, wherein, The air side comprises an air inlet manifold, the air inlet manifold is provided with a fan, each pipeline is provided with an air butterfly valve, and the rear side of each air butterfly valve is provided with a one-way valve.

9. The fuel cell system of claim 1, wherein, The air side comprises an air inlet manifold, the air inlet manifold is provided with a fan, each pipeline is provided with an electric proportional valve, and the rear side of each electric proportional valve is provided with a one-way valve.

10. The fuel cell system of claim 1, wherein, The air side comprises an air inlet manifold, the air inlet manifold is provided with a fan, each pipeline is provided with a mass flow controller, and the rear side of each mass flow controller is provided with a one-way valve.

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