Performance investigation of linear evacuated absorber of 2-stage solar Linear Fresnel Reflector module under non-uniform flux distribution

Performance and heat loss analyses have been carried out for a 2-stage parabolic receiver system of the solar Linear Fresnel Reflector module. Performance of the system with non-uniform distribution of the flux on the absorber and the influence of the wind on the receiver system are investigated. Solar flux distribution on the surface the absorber is applied by user-defined function to analyse the heat loss under the real-time scenario. The performance of the absorber tube when coated or uncoated with a selective material is studied for different flux conditions. This provides a perception to adopt appropriate coating material for different locations under varied DNI conditions. The investigation has been carried out to analyse the heat loss effects when the absorber is placed under evacuated and non-evacuated conditions. All the modes of heat transfer are considered in the study and the dominance of each mode of heat transfer is highlighted. Performance of the numerical data with the non-uniform flux distribution on the absorber with the measured velocity and emissivity values are validated with the experimental data. Deviation of ±10 % is observed between the experimental and the numerical values.