Experimental investigation of an air heating system using different types of heat exchangers incorporated with an evacuated tube solar collector

Abstract

In this article, the thermal performance of a solar air heating system is experimentally investigated. In this system, an evacuated tube solar water heater is connected to a heat exchanger with connecting pipes. The evacuated tubes are used to produce hot water. This hot water flows to the heat exchanger through connecting pipes, the flow of hot water occurs due to thermosyphon phenomenon. Hot air is generated by passing ambient air through the heat exchanger. Three different types of heat exchanger viz. type‐I, type‐II and type‐III have been used. The height of the heat exchangers has been varied from 1050 mm to 1800 mm to evaluate the effect of height variation on the natural circulation flow rate of hot water. The maximum measured temperature difference between the hot air and the ambient air achieved was 10.7°C which was obtained with the heat exchanger type‐II at the height of heat exchanger from ground level of 1550 mm. © 2016 American Institute of Chemical Engineers Environ Prog, 36: 232–247, 2017