The thermal –fluid investigation of effects of different wall boundary conditions on platinum catalytic micro-channel combined with a thermoelectric system

Abstract

In this work, the effects of different regimes of boundary conditions such as convective heat transfer coefficient, insulated wall jointed by slip flow, thermal jump and slip-jump cases are investigated. In all cases of solution, an output voltage/power is achieved from a thermoelectric that is mounted on upper wall of catalytic micro-channel. The solution of this problem is done with coupled fluid (transport species model) and solid (wall of micro-channel and bottom legs of thermoelectric) sections. Furthermore, the electrical values are calculated with an algebraic code prepared into FORTRAN software. The variations of normalized temperature are compared with experimental data that show acceptable agreements with maximum error of 38% for non-slip and 18% for slip boundary conditions. Therefore, the slip wall boundary condition is more precise than non-slip condition. The values of generated power of thermoelectric have the maximum difference of 18% between slip and non-slip condition at inlet velocity of 0.3 m/s. The complete conversion of methane is occurred in insulated wall condition while the lowest value is achieved at thermal-jump condition with 85.46% methane conversion. Increasing inlet velocity the generated electrical power of thermoelectric decreases that is as results of decreasing the average temperature of hot legs of thermoelectric. Furthermore, non-continuity of temperature and continuity of velocity profiles increases output voltage and generated power of thermoelectric.