Decoupling research on thermal effect of microwave-induced discharge with spherical carbon-based dielectric

Microwave discharge is effective in improving microwave energy conversion efficiency due to its significant thermal effect. An in-depth analysis of the thermal effect is the key to understanding the nature of microwave discharge. However, the mechanism of thermal effect of microwave discharge is still unclear because of the deficiency of decoupling research on the thermal effect in the process of microwave discharge. Consequently, the spherical carbon-based dielectric is used for igniting microwave discharge, and the total heat generated in the discharge process is stripped into the electromagnetic conversion heat and the additional heat generated by the discharge. On this basis, a model matching microwave-induced discharge with the spherical carbon-based dielectric is established. Furthermore, the heat transfer mode of discharge additional heat source is discussed and its heat generation rate is calculated. The results show that the errors between the temperature rise curves obtained by this model and the real measured curves are kept within +/- 5%. The heat generation rate of discharge additional heat source is a function of the average temperature of the dielectric gaps, following a relation of qDA, i(T) = Ai + BiT + CiT2. The work is of great significance to reveal the mechanism of thermal effect in process of microwave discharge.