A Calculation Method for Evaluating Thermal Loss of Solar Cavity Receiver

One of the most important components of solar thermal power system is the solar central receiver, which performance is in direct relation to the efficiency of the whole power generation system. The calculation of internal surface heat flux and thermal efficiency of receiver therefore plays a very important role in receiver design. A calculation method of heat loss of a cavity receiver is put forward in this paper. The first step of this method is to use the Monte Carlo method to simulate the track of solar beam and compute surface heat flux inside the receiver. The second step is to employ the correlations of flow boiling heat transfer to figure out the convective heat transfer coefficient inside the tubes and then the wall temperature of the boiling tubes laid inside the receiver. The last step is to simulate the air flow field inside the receiver to calculate convective thermal loss of the receiver. As every step can not be independently done, all steps are coupled and an iterative scheme is needed. Internal surface heat flux and thermal efficiency of the receiver can be finally gained with this method, and the result can provide theoretical guide for receiver design.