Asymptotic Analysis for the Effects of Anode Inlet Humidity on the Fastest Power Attenuation Single Cell in a Vehicle Fuel Cell Stack

Abstract

A three-dimensional and isothermal anode relative humidity (ARH) model is presented and used to study the anode inlet humidity effects on the fastest power attenuation single cell in a vehicle fuel cell stack. The ARH model is based on the phenomenon that the anode is more sensitive than the cathode to water flooding. The pressure drop is considered in the ARH model, and saturation pressure is established by a pressure drop. Based on the pressure drop and relative humidity, simulations and tests are completed. First, the geometric model and computational grids are established, based on real structure of the proton exchange membrane fuel cell (PEMFC). Second, single cell distribution in the stack, test schematic and experimental conditions are demonstrated. Finally, polarization curves with 10 cells are displayed and discussed under these conditions that working temperature 70 °C, and diverse relative humidity (40%, 55%, 70%, 85%, and 100%). The test results of 34 cm2 fuel cell stack are compared against simulation results. The results show that C10 (the single cell with the farthest distance from the gas inlet) power attenuation is the fastest and that its performance is the poorest under the experimental conditions. The polarization curves predicted by the ARH model indicate fairly good coherence with the experimental results, compared against the Fluent original model. The ARH model calculation deviation is 28% less than the Fluent model at 360 mA·cm−2 for a relative humidity of 85%. The current density distribution is almost uniform, and membrane water content is negatively affected by high humidity.

Lowering the Pressure Drop and Cost of a Proton Exchange Membrane Fuel Cell by Flow Field Plate Design

“…Nowadays, with the aggravation of environmental pollution and the depletion of fossil energy, there is an urgent need for a new type of power plant. The proton exchange membrane fuel cell (PEMFC), as the fourth-generation generator set and the generator set instead of the internal combustion engine, has become the focus of attention. − Moreover, the PEMFC has high energy conversion efficiency and stability, which makes it applicable to various fields. − However, the reason why the commercialization of the PEMFC is hindered is that it has a high cost of manufacture and an excessive pressure drop. Furthermore, the types of flow field plates have a significant impact on the pressure drop and cost of the PEMFC. − In addition, intelligent manufacturing as the current cutting-edge production mode has not been applied to the manufacture of flow field plates. , Therefore, this article lowers the pressure drop and cost of the PEMFC by a novel flow field plate design.…”