Energetic and Exergetic Performance of an Evacuated Tube U-Type Solar Collector for Medium-Temperature Industrial Process Air Heating: An Experimental Study

In this research work, experiments are conducted in a U-type evacuated tube solar collector (ETSC), which can be used for producing medium-temperature industrial process hot air. The amount of heat gain, thermal performance, and efficiency of the U-type ETSC with air as the working fluid are studied experimentally. Solar radiation is found as the main important parameter for the efficiency and higher collector outlet temperatures. The values of the highest collector efficiencies are observed between 1:30 PM and 2 PM due to higher solar radiation at this time. The energetic and exergetic efficiencies of the collector are determined, and the results are presented in this paper. From the experimental results, it can be concluded that the developed U-type with ETSC can be useful for medium-temperature industrial process heating applications.