Search

CN-116960389-B - Fuel cell system and control method thereof

CN116960389BCN 116960389 BCN116960389 BCN 116960389BCN-116960389-B

Abstract

The invention discloses a fuel cell system and a control method thereof, wherein the system comprises a fuel cell stack and a heating device, the fuel cell stack comprises an end plate and a first fuel cell arranged adjacent to the end plate, the first fuel cell comprises a first bipolar plate close to the end plate and a second bipolar plate far away from the end plate, a first sealing element is arranged between the first bipolar plate and the end plate and is made of a high Wen Yibian-shaped material, anode gas is introduced into a cavity formed by the first bipolar plate, the end plate and the first sealing element, and the heating device increases the temperature of the anode gas under the running state so as to enable the first sealing element to shrink and deform under heating. Therefore, the voltage of the end cell can be simply and effectively improved without changing the structural design of the fuel cell stack or disassembling the fuel cell stack, the consistency of the single cell voltage is improved, the reliability of the fuel cell stack is improved, the use cost of the fuel cell stack is reduced, and the improvement effect on the large-area fuel cell is particularly obvious.

Inventors

  • HOU XIAOLING
  • SHANG LEI

Assignees

  • 未势能源科技有限公司

Dates

Publication Date
20260508
Application Date
20220414

Claims (10)

  1. 1. A fuel cell system, characterized by comprising: The fuel cell stack comprises an end plate and a first fuel cell arranged adjacent to the end plate, wherein the first fuel cell comprises a first bipolar plate close to the end plate and a second bipolar plate far away from the end plate, a first sealing element is arranged between the first bipolar plate and the end plate, the first sealing element is made of a high Wen Yibian-shaped material, and anode gas is introduced into a cavity formed by the first bipolar plate, the end plate and the first sealing element; and a heating device that increases the temperature of the anode gas in an operation state to shrink and deform the first seal member by heating.
  2. 2. The fuel cell system according to claim 1, wherein the fuel cell stack further includes at least one second fuel cell distant from the end plate, and the heating means stops increasing the temperature of the anode gas when it is determined that a voltage difference between the voltage of the first fuel cell and an average voltage of the at least one second fuel cell is smaller than a voltage threshold.
  3. 3. The fuel cell system according to claim 2, further comprising control means for acquiring a current density of the fuel cell stack, and increasing a flow rate of cathode gas to the fuel cell stack when it is determined that the current density is greater than a density threshold value, and controlling the heating means to raise a temperature of the anode gas when it is determined that a voltage increase amount of the first fuel cell is greater than an average voltage increase amount of the at least one second fuel cell.
  4. 4. The fuel cell system according to any one of claims 1 to 3, further comprising a heat exchanger that exchanges heat with the anode gas in the operation state, wherein the heating device increases the water temperature of the heat exchanger to increase the temperature of the anode gas in the operation state.
  5. 5. The fuel cell system of any of claims 1-3, wherein the first seal has a linear expansion coefficient of 3% -4%/°c at an ambient temperature of-40-100 ℃.
  6. 6. The fuel cell system according to claim 1, wherein the temperature rise range of the anode gas is 5 to 15 ℃ in response to the heat supply of the heating device.
  7. 7. A method of controlling a fuel cell system, the system comprising a fuel cell stack including an end plate, a first fuel cell disposed adjacent to the end plate, the first fuel cell including a first bipolar plate proximate to the end plate and a second bipolar plate distal to the end plate, a first seal disposed between the first bipolar plate and the end plate, the first seal being of a high Wen Yibian shape, an anode gas being vented to a cavity defined by the first bipolar plate, the end plate, and the first seal, the method comprising: Identifying whether the first fuel cell is in a low-pressure state; in response to the first fuel cell being in the low-pressure state, the temperature of the anode gas is raised to thermally shrink-deform the first seal.
  8. 8. The control method of a fuel cell system according to claim 7, wherein the fuel cell stack further includes at least one second fuel cell remote from the end plate, the method further comprising: Acquiring a voltage difference between the voltage of the first fuel cell and the average voltage of the at least one second fuel cell; and stopping increasing the temperature of the anode gas when the voltage difference value is determined to be smaller than a voltage threshold value.
  9. 9. The control method of the fuel cell system according to claim 8, characterized in that the identifying whether the first fuel cell is in a low-voltage state includes: Acquiring the current density of the fuel cell stack; Increasing a cathode gas flow rate to the fuel cell stack when the current density is determined to be greater than a density threshold; acquiring a voltage increase amount of the first fuel cell and an average voltage increase amount of the at least one second fuel cell; And determining that the first fuel cell is in the low-voltage state when the voltage increase of the first fuel cell is determined to be greater than the average voltage increase of the at least one second fuel cell.
  10. 10. The control method of a fuel cell system according to any one of claims 7 to 9, wherein a linear expansion coefficient of the first seal member is 3% -4%/°c at an ambient temperature of-40 to 100 ℃.

Description

Fuel cell system and control method thereof Technical Field The present invention relates to the field of fuel cell technologies, and in particular, to a fuel cell system and a control method thereof. Background A fuel cell is a high-efficiency energy conversion power generation device that converts chemical energy in fuel and oxidant into electric energy directly in an electrochemical reaction without a combustion process using hydrogen as an optimal fuel. The method is free from a heat engine process and is not limited by Carnot cycle, and the actual energy conversion efficiency is as high as 50-80%. The proton exchange membrane fuel cell is a fifth generation fuel cell developed after alkaline fuel cells, phosphoric acid fuel cells, molten carbonate fuel cells and solid oxide fuel cells, and has the characteristics of low working temperature, short starting time, high power density, quick load response, no electrolyte loss and the like. The fuel cell stack is formed by combining a plurality of fuel cells in a stacked manner by bolts, steel belts, or the like. The fuel cell stack fastened by the bolts has the problems that the deformation of the end plates causes different deformation of the bipolar plates close to the end plates, the different deformation causes different sectional areas of flow channels entering the stack and different pressure drops of gas, the different pressure drops of the gas cause uneven distribution of the gas among cells, and the problem that the distribution of the gas is small, particularly the distribution of the gas is insufficient, the gas is not smooth and the like near the fastening bolts of the end plates, so that the voltage of the end cells is low. And poor uniformity of the cell voltages can affect the performance of the stack. Under the same current density, the battery with lower voltage is always in the state of lowest voltage in the load changing process, and under the extreme condition, the voltage of the battery can be gradually reduced to be close to 0V or even damaged, so that the use cost of the electric pile is increased. This problem is particularly pronounced during testing and use of large area fuel cell polarization. Disclosure of Invention The present invention aims to solve at least one of the technical problems in the related art to some extent. Therefore, a first object of the present invention is to provide a fuel cell system, which can simply and effectively increase the voltage of the end cells, improve the uniformity of the voltage of the single cells, increase the reliability of the fuel cell stack, reduce the use cost of the fuel cell stack, and particularly has obvious improvement effect on the large-area fuel cells. A second object of the present invention is to provide a control method of a fuel cell system. In order to achieve the above object, an embodiment of the first aspect of the present invention provides a fuel cell system, which includes a fuel cell stack including an end plate, a first fuel cell disposed adjacent to the end plate, the first fuel cell including a first bipolar plate close to the end plate and a second bipolar plate far from the end plate, a first seal member disposed between the first bipolar plate and the end plate, the first seal member being of a material of Wen Yibian height, an anode gas being introduced into a cavity formed by the first bipolar plate, the end plate and the first seal member, and a heating device for increasing a temperature of the anode gas in an operating state so as to shrink and deform the first seal member by heating. According to the fuel cell system provided by the embodiment of the invention, the fuel cell stack comprises the end plate and one first fuel cell arranged adjacent to the end plate, the first fuel cell comprises the first bipolar plate close to the end plate and the second bipolar plate far away from the end plate, the first sealing element is arranged between the first bipolar plate and the end plate and is made of a high Wen Yibian-shaped material, anode gas is filled in a cavity formed by the first bipolar plate, the end plate and the first sealing element, and the temperature of the anode gas is increased through the heating device under the running state so that the first sealing element is heated, contracted and deformed. Therefore, the voltage of the end cell can be simply and effectively increased, the consistency of the voltage of the single cell is improved, the reliability of the fuel cell stack is improved, the use cost of the fuel cell stack is reduced, and the improvement effect on the large-area fuel cell is particularly obvious. According to one embodiment of the invention the fuel cell stack further comprises at least one second fuel cell remote from the end plate, and the heating means stops increasing the temperature of the anode gas upon determining that the voltage difference between the voltage of the first fuel cell and the average voltage of the at le