SIMULATION OF WATER FLOWS IN EVACUATED TUBE SOLAR COLLECTORS

Abstract

The circulation of water in evacuated tube solar collectors has a major influence on the process of receiving and transmitting solar energy, so that it directly influences the performance of collectors. Thus, a simulation of water flows in the collector was developed in the paper. The process was studied in various modes depending on the total absorbed radiation that evacuated tubes absorb, the average water temperature and the transverse incidence radiation angles. The simulation results show that the mass flow rate of water through the tube increases considerably when the total absorbed radiation increases. In addition, the average water temperature in system and transverse incidence radiation angles also affect the flow of water. These results can be used to study the temperature stratification in the tank as well as calculate the convective heat transfer coefficient of water in the tube, which is an important performance parameter of the collectors.