An apparatus for improving reliability of a fuel cell system

Abstract

The application relates to the technical field of fuel cell system reliability, and discloses a device for improving the reliability of a fuel cell system, which comprises a stack, a hydrogen circulation loop connected with the stack, a condensate water loop connected with the stack and a heating structure, the heating structure is arranged on the hydrogen circulation loop, the heating structure is connected with a hydrogen outlet of the stack, the heating structure is connected with a condensate water inlet of the condensate water loop, and the heating structure is connected with a condensate water outlet of the condensate water loop. The hydrogen gas flowing back from the stack outlet is heated by the condensate water with a high temperature in the water circuit, so that the liquid water in the saturated wet hydrogen gas after being condensed again by the water distribution device is prevented from entering the hydrogen gas backflow structure and the stack, the fault of the hydrogen gas backflow structure caused by the liquid water is solved, and the reliability of the stack is improved.

Description

Technical Field

[0001] This invention relates to the field of fuel cell system reliability technology, and in particular to a device for improving the reliability of fuel cell systems. Background Technology

[0002] During the operation of a fuel cell, the temperature, pressure, and flow rate on the cathode and anode sides must all be within the required range. At this time, the fuel cell performance and reliability will reach the optimal effect. However, due to unreasonable system layout, the actual operating conditions of the fuel cell often deviate from the required operating conditions.

[0003] The current problems with fuel cell systems are as follows: liquid water entering the stack causes flooding; liquid water entering the hydrogen recirculation structure causes malfunctions in the hydrogen recirculation structure; due to insufficient hydrogen supply, the proton activity of the stack decreases, and the interfacial potential difference between the anode or cathode and the motor and membrane increases, leading to carbon corrosion and water electrolysis reactions, resulting in low voltage in one or more cells.

[0004] The temperature of the hydrogen gas at the fuel cell outlet after passing through the water separator and pipeline is lower than the fuel cell temperature. Therefore, the saturated wet hydrogen gas at the fuel cell outlet will condense again. The condensed water will enter the hydrogen reflux structure and the fuel cell, which will seriously reduce the reliability of the hydrogen reflux structure and the fuel cell. Summary of the Invention

[0005] To address the problem in existing technologies where liquid water enters the fuel cell stack and hydrogen circulation device, leading to a decrease in the reliability of the fuel cell system, this invention provides a device for improving the reliability of the fuel cell system.

[0006] The technical solution of the present invention is as follows:

[0007] An apparatus for improving the reliability of a fuel cell system, comprising:

[0008] The fuel cell stack, a hydrogen circulation loop connected to the fuel cell stack, a condensate circuit connected to the fuel cell stack, and a heating structure are provided. The heating structure is disposed on the hydrogen circulation loop and is connected to the hydrogen outlet of the fuel cell stack. The heating structure is connected to the condensate inlet of the condensate circuit and the condensate outlet of the condensate circuit.

[0009] Furthermore, the hydrogen circulation loop includes a hydrogen reflux structure, the heating structure is connected to the hydrogen reflux structure, and the end of the hydrogen reflux structure away from the heating structure is connected to the hydrogen inlet of the fuel cell stack.

[0010] Furthermore, the hydrogen circulation loop also includes a water distribution component disposed at the hydrogen outlet and a hydrogen injection valve disposed at the hydrogen inlet. The hydrogen injection valve is connected to the hydrogen reflux structure. The hydrogen reflux structure, the hydrogen injection valve, the fuel cell stack, the water distribution component, and the heating structure are sequentially connected to form the hydrogen circulation loop.

[0011] Furthermore, the heating structure is a first heat exchange plate, which is connected to the water distribution component and the hydrogen reflux structure.

[0012] Furthermore, the condensate circuit includes a circulating water pump, a cold start heater, a radiator, and an electronic thermostat. The cold start heater is connected in parallel with the radiator, the cold start heater is connected to the electronic thermostat, the radiator is connected to the electronic thermostat, the electronic thermostat is connected to the condensate inlet, and the circulating water pump is connected to the condensate outlet.

[0013] Furthermore, the device for improving the reliability of the fuel cell system also includes a second heat exchange plate, which is connected to the hydrogen injection valve, the condensate inlet of the condensate circuit, and the condensate outlet of the condensate circuit.

[0014] Furthermore, the second heat exchange plate is connected to a hydrogen system that provides hydrogen gas.

[0015] Furthermore, the hydrogen circulation loop is connected to a hydrogen discharge valve.

[0016] The beneficial effects of this invention include: heating the hydrogen returning from the fuel cell outlet using high-temperature condensate from the water circuit, preventing liquid water from re-condensing after the saturated wet hydrogen passes through the water separator from entering the hydrogen return structure and the fuel cell, thus solving the problem of malfunctions in the hydrogen return structure caused by liquid water and improving the reliability of the fuel cell. Attached Figure Description

[0017] Figure 1 This is a schematic block diagram of the device for improving the reliability of a fuel cell system according to the present invention.

[0018] in:

[0019] 1-Fuel stack;

[0020] 2-Hydrogen cycle loop;

[0021] 201 - Water distribution component; 202 - Hydrogen reflux structure; 203 - Hydrogen injection valve;

[0022] 3-Condensate circuit;

[0023] 301 - Circulating water pump; 302 - Cold start heater; 303 - Radiator; 304 - Electronic thermostat;

[0024] 4- Heating structure;

[0025] 5-Second heat exchange plate;

[0026] 6-Hydrogen system;

[0027] 7- Hydrogen discharge valve. Detailed Implementation

[0028] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0029] Combination Figure 1 As shown, the present invention provides an apparatus for improving the reliability of a fuel cell system, comprising:

[0030] The fuel cell stack 1, a hydrogen circulation loop 2 connected to the fuel cell stack 1, a condensate loop 3 connected to the fuel cell stack 1, and a heating structure 4 are provided. The heating structure 4 is a first heat exchange plate, which is installed on the hydrogen circulation loop 2 and connected to the hydrogen outlet of the fuel cell stack 1. The first heat exchange plate is connected to the condensate inlet of the condensate loop 3 and the condensate outlet of the condensate loop 3. The hydrogen circulation loop 2 includes a hydrogen reflux structure 202, which is connected to the first heat exchange plate. The end of the hydrogen reflux structure 202 away from the first heat exchange plate is connected to the hydrogen inlet of the fuel cell stack 1. The first heat exchange plate, the hydrogen reflux structure 202, and the fuel cell stack 1 are connected in sequence to form the hydrogen circulation loop 2.

[0031] The hydrogen circulation loop 2 also includes a water distribution component 201 located at the hydrogen outlet and a hydrogen injection valve 203 located at the hydrogen inlet. The hydrogen injection valve 203 is connected to the hydrogen reflux structure 202, and the water distribution component 201 is connected to the first heat exchange plate. The water distribution component 201, the first heat exchange plate, the hydrogen reflux structure 202, the hydrogen injection valve 203 and the fuel cell stack 1 are connected in sequence to form the hydrogen circulation loop 2.

[0032] The condensate circuit 3 includes a circulating water pump 301, which is located at the condensate outlet. The condensate circuit 3 also includes a cold start heater 302, a radiator 303, and an electronic thermostat 304. The cold start heater 302 and the radiator 303 are connected in parallel. The cold start heater 302 is connected to the electronic thermostat 304. The radiator 303 is connected to the electronic thermostat 304. The electronic thermostat 304 is located at the condensate inlet.

[0033] A second heat exchange plate 5 is connected to the hydrogen circulation loop 2. The second heat exchange plate 5 is connected to the hydrogen injection valve 203. The second heat exchange plate 5 is connected to the condensate inlet of the condensate loop 3 and the condensate outlet of the condensate loop 3.

[0034] The second heat exchange plate 5 is externally connected to a hydrogen system 6, which provides a source of hydrogen for it.

[0035] The hydrogen circulation loop 2 is also connected to a hydrogen discharge valve 7, which is connected to the hydrogen reflux structure 202. The hydrogen reflux structure 202 includes conventional equipment for realizing hydrogen reflux, such as a hydrogen reflux pump and an ejector.

[0036] After the first heat exchange plate is connected to the condensate circuit, when the fuel cell is started or running, the high-temperature condensate flows through the connecting pipe of the first heat exchange plate to the condensate inlet, and then reaches the first heat exchange plate for heating. The saturated wet hydrogen gas that is returning from the hydrogen outlet of the fuel cell stack 1 is heated on the first heat exchange plate, which prevents the liquid water after the saturated wet hydrogen gas that has passed through the water separator 201 from condensing again from entering the hydrogen circulation structure and the fuel cell stack 1. Afterwards, the condensate flows from the first heat exchange plate through the connecting pipe of the first heat exchange plate to the condensate outlet and flows back to the condensate circuit.

[0037] After the second heat exchange plate is connected to the condensate circuit, when the fuel cell is started or running, the hydrogen gas that enters the hydrogen circulation circuit through the hydrogen system first flows through the second heat exchange plate. The condensate flows into the second heat exchange plate through the connecting pipe between the second heat exchange plate and the condensate inlet, where the gas is heated. After that, the condensate flows back to the condensate circuit from the connecting pipe between the second heat exchange plate and the condensate outlet.

[0038] The hydrogen recirculation structure of this invention solves the problems of liquid water entering the hydrogen circulation pump, causing the hydrogen circulation pump to stop or operate at low speed, and liquid water entering the ejector, causing the outlet flow rate to not meet requirements. It effectively solves the problem of liquid water entering the fuel cell stack and improves the reliability of the fuel cell system.

[0039] Figure 1 The arrows in the diagram indicate the direction of flow for hydrogen gas and condensate.

[0040] The above description is merely an embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural or procedural transformations made based on the content of the present invention's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of the present invention.

Claims

1. A device for improving the reliability of a fuel cell system, characterized in that: include: The fuel cell stack, a hydrogen circulation loop connected to the fuel cell stack, a condensate circuit connected to the fuel cell stack, and a heating structure are provided. The heating structure is disposed on the hydrogen circulation loop and is connected to the hydrogen outlet of the fuel cell stack. The heating structure is connected to the condensate inlet of the condensate circuit and the condensate outlet of the condensate circuit. The hydrogen circulation loop includes a hydrogen recirculation structure, the heating structure is connected to the hydrogen recirculation structure, and the end of the hydrogen recirculation structure away from the heating structure is connected to the hydrogen inlet of the fuel cell stack. The hydrogen circulation loop also includes a water distribution component disposed at the hydrogen outlet and a hydrogen injection valve disposed at the hydrogen inlet. The hydrogen injection valve is connected to the hydrogen reflux structure. The hydrogen reflux structure, the hydrogen injection valve, the fuel cell stack, the water distribution component and the heating structure are sequentially connected to form the hydrogen circulation loop. The heating structure is a first heat exchange plate, which is connected to the water distribution component and the hydrogen reflux structure. The device for improving the reliability of the fuel cell system further includes a second heat exchange plate, which is connected to the hydrogen injection valve, the condensate inlet of the condensate circuit, and the condensate outlet of the condensate circuit.

2. The device for improving the reliability of a fuel cell system according to claim 1, characterized in that: The condensate circuit includes a circulating water pump, a cold start heater, a radiator, and an electronic thermostat. The cold start heater is connected in parallel with the radiator, the cold start heater is connected to the electronic thermostat, the radiator is connected to the electronic thermostat, the electronic thermostat is connected to the condensate inlet, and the circulating water pump is connected to the condensate outlet.

3. The device for improving the reliability of a fuel cell system according to claim 1, characterized in that: The second heat exchange plate is connected to a hydrogen system, which provides hydrogen gas.

4. The device for improving the reliability of a fuel cell system according to claim 1, characterized in that: The hydrogen circulation loop is connected to a hydrogen discharge valve.

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