A novel phase optimization method to improve microwave heating uniformity

Abstract

Microwave heating of food is common in daily life, where uniformity of heating is a crucial factor for ensuring processing quality. However, although previous studies have shown that microwave phase can influence heating uniformity, little attention has been paid to the utilization of phase optimization for enhancing uniformity. This paper innovatively proposed a real-time phase optimization method to enhance microwave heating uniformity, which was based on the establishment of a dual-port phase multi-physics model. Volumetric temperature distributions of the heated object were obtained by scanning with a phase step size of 20° from 0 to 360°. Then, the real-time feedback of volumetric temperature distribution was used to perform complementary phase selection, ultimately determining the optimal phase for each time interval. The results showed that the proposed method improved uniformity by over 40 % compared to fixed phase heating. The corresponding phase optimization experimental system was established by using the solid-state microwave source, and the heating performance of potato samples in different phase modes was compared and analyzed by using a thermal imaging camera. Experimental and computational results showed good consistency, which verified the correctness of the model and the superiority of the proposed method in improving the heating performance. Finally, the heating performance of different initial phases, different object shapes and higher input power is analyzed, indicating that the proposed method has good universality. This study provides a new approach which aims to improve heating uniformity and contributes to the more efficient application of microwaves in food engineering.