Experimental performance of hot water production by solar PV/T boosted heat pump system for electric power costs reduction in a slaughterhouse
This research presents the experimental performance of hot water production by solar PV/T boosted heat pump system in actual use in a slaughterhouse at Chai Prakan District, Chiang Mai Province. The system consists of a heat pump of 17.8 kWth, using R134a as a refrigerant. At the heat pump evaporator, the additional heat was supplied from a glazed solar photovoltaic thermal panel (PV/T) which peak power was 295 WP amounts 4 panels. The heat pump was powered by 14 panels of the solar photovoltaic panel which each peak power was 370 WP for hot water production in the storage tank of 3,000 liters for use in the scalding and scraping of pigs processing that required hot water was approximately 65°C. The results showed that the overall efficiency of solar PV/T boosted heat pump was equal to 59.28%, moreover, the average energy efficiency ratio (EER) was 3.17 kWth/kWe which was higher than the heat pump without solar PV/T with an average EER was 2.79 kWth/kWe. For the electric cost analysis of the scalding and scraping process, the specific energy consumption (SEC) could be reduced from 7.27 kWh/pig to 1.25 kWh/pig, or a cost was reduced from 33.15 Baht/pig to 5.70 Baht/pig. In overview, the used electric power from grid line was reduced about 30,361.24 kWh/year, which was equivalent to 138,447.24 baht/year or about 82.80% of electric power cost compared with the only electrical heater use. The system cost invested 708,060 Baht, so the payback period was equal to 5.49 years and the internal rate of return (IRR) was 17.31%, respectively.