Numerical Study on Thermoelectric Power Generator in Combustor

Micro gas turbine is a typical distributed energy resource system. The temperature of the burning gas in the combustor reaches 1000 K or even more, which makes a huge temperature difference in the combustor an interesting topic for heat recovery. In this work, thermoelectric devices are used for heat recovery in the combustor of the micro gas turbine. A flow-thermal-electric multiple-physical numerical model is used for the combustor and thermoelectric device power generation system. The effect of the winglet vortex generators installed at the outer wall of the flame tube on the system performance is examined. The numerical results show that the best matching load is about 1.4 times the internal resistance which provides the maximum power output for the thermoelectric generator. Active cascade control of heat transfer enhancement elements on flame tube considering wall safety and conversion efficiency of thermoelectric generator under high temperature and large temperature drop is proposed. The numerical results show that the conversion efficiency of thermoelectric generator can be increased by more than 80%, and the average wall temperature can be reduced by 35 K by using non-uniform arrangement of the winglet vortex generators.