Heat transfer enhancement and field synergy analysis of vacuum collector tube with inserted rotor

Aiming at the large heat loss inside the traditional trough-type vacuum solar heat collecting tube, a new type of spiral three-blade rotor structure was designed and inserted into the inner tube side of the heat collecting tube. Based on the principle of fluid dynamics and field synergy, a mathematical model of the three governing equations of the fluid in the tube was established. Numerical simulations of the heat transfer and flow in the flow field in the two types of collector tubes with or without interpolated rotors were performed. Performance comparisons were made in terms of velocity field, pressure field, temperature field, and field synergy coupling ability. The results of the comprehensive evaluation index of heat transfer performance were finally given. The research shows that the PEC value continues to become larger with the increase in the inlet flow rate, from an initial value of 1.63 to a final value of 2.69. The heat transfer performance enhancement advantage of the new type vacuum heat collector tube is obviously greater than the disadvantage of flow resistance, and the comprehensive performance is better.