Research and review study of solar dish concentrators with different nanofluids and different shapes of cavity receiver: Experimental tests

In this study, the thermal performance of a solar dish concentrator with different cavity receivers and nanofluids was experimentally studied. The first step in this work is a detailed literature review of the studies about the solar dish cavity receivers. The second step is the experimental investigation of a solar dish concentrator with a cubical cavity receiver using Al2O3/oil nanofluid and pure thermal oil. The last step of this work is the comparison of the found results with others from the literature in order to make an overall overview of cavity receivers. The finally presented results of the dish concentrator with different cavity receivers (including cubical, cylindrical, and hemispherical cavities) using different nanofluids (including Al2O3/oil, MWCNT/oil, and SiO2/oil nanofluids are reported based on a same experimental setup that was designed and built by authors of this research. The results reveal that the hemispherical and the cubical cavities are the most effective designs, while the cylindrical cavity presents lower performance. Moreover, it was found that the use of nanofluids always leads to thermal performance enhancement. More specifically, it was found that the mean thermal efficiency enhancement with the use of nanofluids is 12.90% with the hemispherical cavity, 5.84% with the cubical cavity and 1.44% with the cylindrical cavity.