Performance enhancement of natural circulating storage type

Abstract

Performance of solar water heater was simulated for one extraction per day (at 18:59 h), two extractions per day (12:00 & 18:59 h) and hourly extractions (06:00 - 18:59 h). Annual thermal energy output (for 2 m² collector system) was 1181.65, 1354.69 and 1585.89 kWh/m²/year at annual collector-tank system efficiency of 59.61, 68.34 and 80.0 % respectively. Maximum temperatures reached at 18:59 h was 92.3°C for one extraction mode and 67.1°C for two extraction mode. Performance can be enhanced (20-30%) through multiple extraction of water over the day by controllable dual tank system and a performance optimizer for electrical back up. Also, average solar radiation and weather data of Bangalore for 1977-2005 is presented.