NUMERICAL SIMULATION OF MICROWAVE ABSORPTION OF REGENERATIVE HEAT EXCHANGERS SUBJECTED TO MICROWAVE HEATING

A 2D numerical model is proposed for designing regenerative heat exchanger that is subjected to microwave heating by coupling of electromagnetism and heat transfer. Simulation aid in understanding the effects of inner diameters and thicknesses of the mullite refractory tube and magnetron operating frequency on the microwave absorption, based on the analysis of reflection loss (RL) of a regenerative heat exchanger consisting of a high-loss SiC honeycomb ceramic, a low-loss mullite refractory tube and a silicate insulation layer. Also the influences of temperature dependent dielectric properties were considered. Numerical results show that the microwave absorption strongly depends on the inner diameters and thicknesses of the mullite refractory tube and magnetron operating frequency. The regenerative heat exchanger has a good absorption when the mullite refractory tube has an inner diameter of 0.140 m and a thickness of 0.015 m.