Effect of gas purging on the performance of a proton exchange membrane fuel cell with dead‐ended anode and cathode

Excellent performance is an important indicator to ensure the commercial development of fuel cells. During the operation of a fuel cell system, nitrogen accumulation will occur at the anode of the fuel cell stack because of hydrogen circulation and nitrogen permeation across the membrane. Nitrogen accumulation will lead to the degradation of fuel cell performance. A suitable purge strategy can effectively reduce the excessive nitrogen concentration. The formulation of the purge strategy is closely related to the change in nitrogen concentration, so the accurate estimation of nitrogen concentration is quite important. In this paper, the effect of nitrogen concentration on fuel cell performance under different current densities is studied, and the anode nitrogen concentration in the fuel cell stack is estimated by back propagation neural network. The identification result of nitrogen concentration based on the voltage of every single cell is more accurate. Without considering aging and working condition changes, mean absolute errors of estimated results are 0.75%, 0.67%, 0.62%, and 0.73%, and root mean square errors are 1.09%, 0.97%, 0.88%, and 0.99% at different current densities of 0.6, 0.8, 1.0, and 1.2 AÁcm À2 , respectively. The results indicate that the estimation method of nitrogen concentration for fuel cell anode based on back propagation neural network has a high accuracy, which can provide a new method for formulating purge strategy for fuel cell system.

Section: Introductionmentioning

confidence: 99%

Methods for estimating the accumulated nitrogen concentration in anode of proton exchange membrane fuel cell stacks based on back propagation neural network

Chen

et al. 2022

“…1,2 Due to its high energy conversion efficiency, low noise, and environment friendly, it is known as the most promising power sources in the 21st century. 3 Through the development of PEMFC technology, fuel cell vehicles (FCVs) have made considerable progress in the international market. Many FCVs produced by many companies such as Honda, Toyota, Hyundai, and General Motors have been demonstrated and sold on a small scale around the world.…”

Section: Introductionmentioning

confidence: 99%

Water distribution and carbon corrosion under high current density in a proton exchange membrane fuel cell

Zhao

Huang

et al. 2021

Self Cite

Carbon corrosion in the catalyst is an important factor limiting the lifetime of proton exchange membrane fuel cells (PEMFCs). The water distribution inside the PEMFC directly determines the carbon support's corrosion rate in the catalyst. This study first investigates the water mole fraction distribution in the catalyst under different operating conditions, such as relative humidity (RH), temperature, pressure. It then divides the catalyst into different flooded areas according to the relationship between the water vapor partial pressure and saturated vapor pressure. Finally, it investigates the carbon corrosion characteristic of each region. The carbon corrosion of the catalyst is mainly divided into the corrosion in the non-flooded area and the corrosion in the flooded area.The results show that the decay rate of carbon support is around 4% after 5000 hours of operation in the non-flooding area. However, the degradation of

“…1 Proton-exchange membrane fuel cell (PEMFC) has been considered as a potential power supply system, due to its environment-friendly adaptability, and high efficiency in directly converting the chemical energy stored in the fuel and oxidant into electricity. 2,3 PEMFCs have rapidly developed over decades of research, but water and thermal management remain as major obstacles in its commercialization, specifically in a complicated system. 4 Thermal management is a significant issue in promoting the reliability and durability of a PEMFC.…”

Section: Introductionmentioning

confidence: 99%

Effect of cathode moisture condensation on temperature distribution characteristics of dead‐ended proton‐exchange membrane fuel cell stack

Pei

Chang

et al. 2021

Self Cite

Thermal and water management are crucial factors affecting the performance of proton-exchange membrane fuel cells (PEMFCs). In this study, a semiconductor cooler was installed at the cathode outlet of a dead-ended fuel cell stack, to condense the water vapor in the stack, and subsequently realize efficient thermal and water management. The temperature distribution characteristics were experimentally studied using a self-built dead-ended PEMFC stack test platform. The effects of operating temperature, current density, and condensation temperature were analysed in detail. The results showed that the output performance of the dead-ended fuel cell stack could be efficiently improved by cathode moisture condensation. The temperature difference in the stack with cathode moisture condensation was much smaller than that without it. The output voltage of the stack could be increased by up to 6.02% with cathode moisture condensation, at an operating temperature of 70 C; and the maximum temperature difference could be reduced by 92.8% upon applying the semiconductor cooler with a condensation temperature of 5 C. Furthermore, the current density significantly affected the temperature distribution. Upon increasing the current density from 0.3 to 0.7 A/cm 2 , the temperature difference increased from 1.37 C to approximately 3 C, due to the large amount of water generated by electrochemical reaction at high current density.