Designing a Robust Analytical Model of a Parabolic Trough Solar Collector Through In-depth Analysis of Convective Heat Transfers

A good mathematical model of parabolic trough solar collector (PTSC) can assist in achieving a variety of research objectives for it such as parametric enhancements, energy analysis, and optimization. Thus, it becomes necessary to explore and present any possible improvements in its modeling; this study inspects the same. In the current study, several correlations available to estimate heat transfers in PTSC are scrutinized; most effective ones are recommended and utilized to draft an analytical model of PTSC. Investigation reveals that if correlations to estimate convective heat transfers are appropriately chosen, then complex radiative heat transfer calculations commonly used by accurate PTSC models can be substituted by simple correlations. It is established that by doing so, model's complexity can be reduced while sustaining its competency. The model has been formulated by applying an in-depth examination of heat transfer correlations and then simulated using MATLAB. Experimental conditions and results reported by Sandia National Laboratory (SNL), USA, and Plataforma Solar de Almería (PSA), Spain, are adapted to validate the model. Model estimations are found to show excellent consistency with experimental results. Regarding four different cases tested by SNL, average root mean square error (RMSE) is recorded to be 0.98 only and 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 models and competent with the most accurate ones. Overall, compared to existing models, the proposed model is faithful, robust, less complex, and valid for wider range.