@ARTICLE{Al-Joboory_Hassan_Naji_Salman_Experimental_2020, author={Al-Joboory, Hassan Naji Salman}, volume={vol. 41}, number={No 3}, journal={Archives of Thermodynamics}, pages={3-31}, howpublished={online}, year={2020}, publisher={The Committee of Thermodynamics and Combustion of the Polish Academy of Sciences and The Institute of Fluid-Flow Machinery Polish Academy of Sciences}, abstract={The present work involved an extensive outdoor performance testing program of a solar water heating system that consists of four evacuated tube solar collectors incorporating four wickless heat pipes integrated to a storage tank. Tests were conducted under the weather conditions of Baghdad, Iraq. The heat pipes were of 22 mm diameter, 1800 mm evaporator length and 200 mm condenser length. Three heat pipe working fluids were employed, ethanol, methanol, and acetone at an inventory of 50% by volume of the heat pipe evaporator sections. The system was tested outdoors with various load conditions. Results showed that the system performance was not sensitive to the type of heat pipe working fluid employed here. Improved overall efficiency of the solar system was obtained with hot water withdrawal (load conditions) by 14%. A theoretical analysis was formulated for the solar system performance using an energy balance based iterative electrical analogy formulation to compare the experimental temperature behavior and energy output with theoretical predictions. Good agreement of 8% was obtained between theoretical and experimental values.}, type={Article}, title={Experimental and theoretical investigation of an evacuated tube solar water heater incorporating wickless heat pipes}, URL={http://journals.pan.pl/Content/117609/PDF/01_paper.pdf}, doi={10.24425/ather.2020.134570}, keywords={Wickless heat pipe, Fill charge, Electrical analogy, Evacuated tube solar collector, water heater, Performance}, }