Numerical Study Of Proton Exchange Membrane Fuel Cell Performance Optimization Based On Combination Parametric Analysis

Proton exchange membrane fuel cell (PEMFC) has became the most promising applications of portable power, small-scale stationary power plants, electric vehicles and other modes of transport power supply ,because its not only have high-energy efficiency, quick start at room temperature, no electrolyte loss, long life, easy to water exclude, but also not subject to Carnot cycle limit. But the actual PEMFC is still in the researching stage, and some of critical questions aren't dissolved. The polarization coincide is one of them, so this paper aims at researching polarization coincide of PEMFC.First in this paper, a parallel flow field PEMFC geometrical model was developed by Gambit2.2, and at the same time, developing a three-dimensional, non-isothermal, steady mathematic model of PEMFC by Fluent6.3. And it describe fluid flow model, mass and heat transfer model, electrochemistry reaction model, water transfer model and so on.Second, combined with orthogonal design, fuzzy entropy weight method and numerical simulation, systematic study the impacting of PEMFC polarization and interactions among the 12 parameters. The results show that: cathode transfer coefficient, cathode exchange current density, oxygen reference concentration, reference diffusion coefficient of oxygen are main affecting factors to the battery polarization; anode exchange current density, diffusion layer absolute permeability have significant influence to the cell polarization; Diffusion layer porosity , hydrogen diffusion coefficient in the reference state , water diffusion coefficient in the reference state have certain influence to the cell polarization; anode transfer coefficient, hydrogen concentration have relatively small impact to the cell polarization. cathode transfer coefficient and reference diffusion coefficient of oxygen, cathode exchange current density and oxygen reference concentration, cathode exchange current density and reference diffusion coefficient of oxygen, oxygen reference concentration and reference diffusion coefficient of oxygen have almighty significant interactions; cathode transfer coefficient and the cathode exchange current density, cathode transfer coefficient and the oxygen reference concentration have significant interaction; cathode transfer coefficient and the cathode exchange current density and oxygen diffusion coefficient in the reference state have certain interaction; the rest of other parameters have relatively small interaction. Final,based on previous studies, according to electrochemical correlation, emphasis research three highly sensitive parameters and three sensitive parameters, try to find polarization curves coincide, and the intrinsic relationship between parameters and polarization coincide. The results show that:(1)under the condition of keeping PEMFC other parameters unchanged, in the parameter value ranges, change the anode reference exchange current density and the concentration of hydrogen, and make it contented specific relationship, polarization curves completely coincide;(2) under the condition of keeping PEMFC other parameters unchanged, in the parameter value ranges, change the cathode reference exchange current density and oxygen concentration, and make it contented specific relationship, polarization curves completely coincide;(3) under the condition of keeping PEMFC other parameters unchanged, in the parameter value ranges, change the anode exchange current density and anode transfer coefficient, and make it contented specific relationship, polarization curves completely coincide;(4) under the condition of keeping PEMFC other parameters unchanged, in the parameter value ranges, change the cathode exchange current density and cathode transfer coefficient, polarization curve can not coincide. But changes the two parameters may make polarization curves piece overlap;(5) under the condition of keeping PEMFC other parameters unchanged, in the parameter value ranges, change the anode exchange current density and cathode exchange current density or anode transfer coefficient and the cathode transfer coefficient, and make it contented specific relationship, the polarization curve can not coincide, but the polarization curves may piece overlap;(6) under the condition of keeping PEMFC other parameters unchanged, in the parameter value ranges, change the anode exchange current density, hydrogen reference concentration, anode transfer coefficient, and make it contented specific relationship, polarization curves completely coincide;(7) under the condition of keeping PEMFC other parameters unchanged, in the parameter value ranges, change the cathode exchange current density, oxygen reference concentration, cathode transfer coefficient, the polarization curve can not coincide. But polarization maybe partly coincide;(8) under the condition of keeping PEMFC other parameters unchanged, in the parameter value ranges, change the anode exchange current density, hydrogen reference to the concentration of the cathode exchange current density, oxygen concentration reference, and make it contented specific relationship, polarization curve can not coincide. But when combined with certain constraints, polarization curves completely coincide.PEMFC performance is influenced by many parameters, the research of combination parameters, not only reduced the parameter research integer, but more importantly is that one brand-new research technique is applicated in PEMFC performance optimization research, and promoted the PEMFC basic study development. Through analyzes the parameters reciprocity, it could revelation the control microscopic mechanism of battery, avoiding the sole parameter research deficiency. Through analysis the combination parameter's physics significance, it could build the foundation for deep research. Through analysis the combination parameter or the constraints and polarization curve's relations, it would give us clear direction about the battery performance optimizes.