Heat Transfer Enhancement Analysis of Collector Tube in LFR-CSP

Abstract

The heat transfer characteristics of the collector tube is one of the cores of a linear Fresnel reflector-solar thermal power generation system (LFR-CSP). In this paper, the heat transfer model of reflective linear Fresnel single-tube compound parabolic collector (CPC) is established. In light of the normal operating conditions during the day, it is found that the direct normal irradiation (DNI) and loop length exert significant effects on the heat collection and thermal loss performance of the linear Fresnel reflector. With the increase of DNI and unit length, the outlet temperature and heat collection capacity of the collector loop increase significantly. Because of the increase of DNI, the increase of collector heat is higher than that of thermal loss. However, the thermal loss per unit length increases correspondingly with the increase in loop length, and the heat collection efficiency decreases. Ambient temperature and wind velocity are not the main factors affecting the heat collection and thermal loss performance of the linear Fresnel reflector under the prerequisite of a good vacuum degree of the collector tube.