Comparative study of parabolic trough solar collector using sysltherm-800 and therminol-VP1 non-metallic nanofluids

Parabolic trough collectors (PTC) are the most established and commercialized solar concentrating technology worldwide. In recent years, there has been a lot of interest in the enhancement of concentrated solar energy's thermal efficiency, particularly in PTC's using different types of nanofluids since they outperform conventional ones (Guo et al., 2018; Sun, 2021). In this paper, a comparative study was carried out for different non-metallic nanoparticles in two base fluids with different absorber configurations (vacuum, air and bare). The effect of inlet temperature, coating material, incident heat flux, and volume flow helps to fill the gap in the literature by investigating the possible choice of optimal materials for PTC solar collectors. Regarding design and mathematical simulation, Python coupled code for both thermal and optical model using Monte Carlo Ray-Tracing Method (MCRT) to analyze thermal efficiency and the local concentration ratio is developed. Results reveal that CuO and CeO2/Therminol-VP1 based nanofluids indicate a maximum heat loss reduction of 5.5%. CuO increases on average by 5.1% per 1% VF (Volume Fraction). Syltherm-800 is more sensitive to selective coating and a higher Re number than Therminol-VP1. Furthermore, Syltherm-800 demonstrates a larger improvement in heat transfer performance than Therminol-VP1 with the addition of nanofluids. According to the results, there is a significant increase in thermal performance between input temperatures of 700 K and 800 K with the increase of nanofluid VF and bare absorber type configuration shows more sensitiveness to nanofluid addition and dependence on the incident solar heat flux.

Automated summary

This paper compares the performance of different non-metallic nanoparticles in two base fluids for the absorber configurations of parabolic trough collectors. The results show that CuO and CeO2/Therminol-VP1 based nanofluids can significantly reduce heat loss. CuO increases the heat absorption rate by an average of 5.1% per 1% VF (Volume Fraction). Syltherm-800 is more sensitive to selective coating and a higher Re number than Therminol-VP1.