Yüksek sıcaklık PEM yakıt pilinin sıcaklık profilinin araştırılması.

High temperature polymer electrolyte membrane fuel cells (HT-PEMFC) are promising alternative energy sources for the future. As an advantageous tool in the design of a system, modeling requires less time compared to the experiments as well as its low cost. This study includes both isothermal and non-isothermal three-dimensional mathematical models for a HT-PEMFC having an active area of 25 cm2. Governing equations are solved by using Comsol Multiphysics 5.0 “Batteries & Fuel Cells” module, which is a commercial software package that solves partial differential equations by using finite element method. Temperature has a crucial role in the operation of HT-PEMFC because of the exothermic reaction taking place at the catalyst layer. Influence of the temperature on the performance is studied for a single channel and triple mixed serpentine geometry with an isothermal model. It is seen that the fuel cell performance is enhanced as the operation temperature increases due to enhanced reaction kinetics and increased proton conductivity of PBI membrane. Higher proton conductivity yields in a decrease in the ohmic losses of the cell. The temperature distribution within the cell is obtained with a non-isothermal three-dimensional model. There is an increase in the temperature approximately 0.31 ᵒC at the operation voltage of 0.45 V, this value lowers at higher operation voltages. It is concluded that exothermic reaction in the cathode catalyst layer does not have a significant effect on the temperature; therefore, isothermal assumption is valid for the system.M.S. - Master of Scienc