فهرست نشریات علمی دسترسی آزاد ایران

The high-demand for solar power systems has stimulated research efforts to find better heat transfer fluids for evacuated tube solar collectors (ETSCs). This research aims to appraise the thermal characteristics of an ETSC, which utilises engine oil as a heat transfer vehicle within a new efficient system beyond conventional flat-plate collectors. Temperature elevation under solar radiation becomes rapid because the evacuated tube contains engine oil with Grade 20-w50, which possesses a high-boiling point of >350 °C and heat transfer properties including 2.5 kJ/kg K heat capacity and 88 kg/m³ density. Experiments are conducted for different ranges of solar radiation intensity with different ranges of engine oil temperatures. According to the results, this system reacts swiftly to solar radiation changes and reaches a maximum temperature of 198 °C at a solar radiation of 800 w/m2, which makes water evaporation and superheating possible. More importantly, in comparison to traditional flat-plate collectors, this collector demonstrates a high conversion efficiency and quick response to the influencing parameters. The introduced approach not only enhances energy efficiency but also brings into line with the United Nations Sustainable Development Goal (SDG 7) to deliver reasonable and clean energy solutions to conflict climate change and improve sustainable industrialization.