Performance analysis of spiral tube solar water heater using concrete/sand absorbers for domestic use

This paper shows the modeling and simulation of spiral tube solar water heater by using concrete absorber. In this paper, the performance of a domestic hot water heating system with solar concrete collector is studied. Although they are less efficient, such collectors integrated with building structures are likely to be more cost effective than conventional flat-plate collectors using metallic absorber plates. A layer of galvanized iron wire mesh on either side of the PVC tubes provides the necessary reinforcement to the concrete, The top of the slab is painted black and glazed, while the back insulation is made out of autoclave cellular concrete. Theoretical study was carried out for different flow rates of water inside the spiral tube varied from 0.006 and 0.01 kg/sec. The average water temperatures of concrete and sand absorber are found as 72°C and 76°C with the same mass equivalence respectively at minimum mass flow rate. Similarly the linear characteristic on storage water temperature and outlet water temperature for both materials is estimated with respect to solar intensity. Due to the single pass arrangement spiral tube arrangement the energy stored on entire surface of absorber is utilized by flowing water. Also, theoretical analysis shows that the solar water heater with straight and serpentine tubes consumes more area than the other conventional solar water heater.