MODELING, OPTIMIZATION, AND CONTROL OF PARABOLIC TROUGH SOLAR COLLECTOR FOR INDUSTRIAL PROCESS HEATING APPLICATIONS

Abstract

The need for technological advancement to control and minimize the reliance on hazardous and defiling energy sources is quite apparent globally. The direct use of solar radiation to generate heat has shown great potential to gradually replace fossil fuels in different spheres like power generation, desalination, process heat in industries, and others. Parabolic trough solar collector (PTSC) is among the pioneers transpiring the mentioned concept. It can convert solar energy to thermal energy and has shown excellent proficiency in the power generation sector. PTSCs also has promising potential to serve industrial process heat (IPH) applications, requiring working temperatures of 50-260°C. The practical realization of the same is still in progress. This investigation explores the possibilities of further improvements possible for PTSC such that it can be a better fit for IPH applications. To comment on PTSCs potential, one must assess its performance against optical and thermal parameters. It is crucial to ensure that it is robust enough to function in challenging conditions. An adequate mathematical model can accomplish several research goals for the PTSC, such as parametric improvements, energy analysis, and optimization. As a result, it becomes vital to theoretically investigate the efficient modeling of the PTSC system and provide any potential performance enhancements. In this line, this investigation proposes a robust analytical thermal model of PTSC, formulated by an in-depth examination of heat transfer correlations. It is revealed that if correlations to estimate convective heat transfers are appropriately chosen, then the complex radiative heat transfer calculations commonly used by accurate PTSC models can be substituted by simple correlations. Consequently, experimental conditions and results reported for three different PTSC setups, two tested by Sandia National Laboratory (SNL), USA, and one by Plataforma Solar de Almeria (PSA), Spain, are adapted to validate the model. The proposed model is simulated using MATLAB and estimations are found to show excellent consistency with experimental results. Different cases tested by SNL for different setups were simulated and in the six different cases, maximum root mean square error (RMSE) was found to be 1.045, for the setup tested at PSA, RMSE value is 1.015. Further, a comparison with other model’s estimations demonstrated that the proposed model is more accurate than many other models in the literature and competent with the most accurate ones.