Investigating two configurations of a heat exchanger in an Indirect Heating Integrated Collector Storage Solar Water Heating System (IHICSSWHS)

Abstract

Water heating makes up 14% of domestic energy usage. Due to the environmental impact of energy usage, consumers need to be encouraged to use renewable energy sources such as solar energy. The indirect heating integrated collector storage solar water heater system (IHISSWHS) is one of the most economical systems. The objective of this study was to investigate ways to enhance the performance of this system to encourage many households using it. Two configurations of the system were studied; 16.2 m long double row heat exchanger (HX) and 8.1m and 10.8 m long single row HX. Inside pipe diameters were 10.7mm and 17.1 mm; using two flow rates 500 L/h and 650 L/h. The steady state continuity, momentum and energy equations were numerically solved, using FLUENT software. A standard k-ω turbulent model and surface to surface radiation was used. The system with 10.8 m long single row HX provided higher outlet temperature than the system with 16.2 m double row. Therefore, a significant reduction in cost and power usage can be achieved by using a single row HX. For both flow rates investigated, the larger diameter pipe need about five folds less power to run, with very little sacrifice of outlet temperature.