Estimating allowable energy flux density for the supercritical carbon dioxide solar receiver: A service life approach

• DOI: 10.1016/j.applthermaleng.2020.116024
• Publication Date: 2020-09-18T15:36:18Z
• Authors: Zhenghua Rao; Siteng Bao; Xianping Liu; Robert A. Taylor; Shengming Liao
• Keywords: Service life; Radiation flux

Abstract The allowable energy flux density on a solar receiver is strongly correlated with the receiver’s service life and, ultimately, the feasibility of the surrounding concentrated solar power plant. Understanding this link may enable high temperature solar receivers which are viable for driving the advanced supercritical CO2 cycle. In this study, by using a receiver’s service life approach based on the simulation of temperature, stress and creep-fatigue damage, the allowable energy flux density of a supercritical CO2 coiled tube receiver is estimated. Our analysis reveals that when solar radiation lands on the coiled tube with an absorbance of 1.0 and 0.6, the allowable flux densities are 138.8 and 172.5 kW/m2, respectively; while when directly exposed to a uniform flux distribution, the allowable energy flux density is 163.80 kW/m2. It is found that since structure failure occurs at the “weakest” region of a receiver (i.e. where the local damage exceeds the total allowable accumulated damage), decreasing the inlet temperature or increasing the flow rate can help to mitigate regions exposed to high temperature and stress, resulting in the higher allowable energy density for receivers. This study is significant because it provides design guidelines for the safe operation of emerging, high temperature, supercritical CO2 solar receivers.