Validation of a Novel Method for Thermal Performance Evaluation of Parabolic Trough Receivers

Parabolic trough receivers are a kind of key components of a solar trough power plant, which absorb and transfer the high flux solar energy to the heat transfer fluid flowing in it. A Receiver Impedance Heating (RIH) method is put forward by analyzing the inadequacies of traditional methods. Voltage is imposed on both ends of the receiver and then the receiver is self-heated via a large electrical current flowing through it based on the Joule Effect. Once the receiver reaches a thermal equilibrium the product of voltage imposed on the receiver and electrical current flowing through the receiver is equal to the heat loss of the receiver to ambient environment at corresponding temperature difference of receiver temperature above ambient. The experiment system is simple, low-cost, and easy to operate. Experiment results show that curve of heat loss is smooth and measurement uncertainty is low, which means accuracy of the experiment results is high, while time period to reach a thermal equilibrium at every absorber temperature reduces to 2-3hours which is one fifth of that needed in traditional methods.