Exergo-economic comparisons of solar cooling systems coupled to series/parallel absorption chiller types considering the lowest heat transfer area

Abstract

District solar assists cooling systems can make full use of local renewable resources, and reduce the fossil fuel consumption and greenhouse gas emissions. After modelling and validation of solar cooling systems, the exergo-economic method is carried out to explore the economic performance by considering the lowest heat transfer areas of two chiller types based on the yearly ambient parameters in Beijing, China. The sensitivity analysis of key parameters is searched to depict the impacts of initialized parameters. The results show that the solar cooling system coupled to parallel chiller needs the lowest solar installation area, 602 m2, and corresponds to the highest coefficient of performance, 1.15, and exergy efficiency, 21.91%. However, due to the higher heat transfer areas of parallel chiller, the specific exergo-economic cost of chilled water, 3.93 $/kWh, is higher than the one of series cooling system, 3.78 $/kWh. The sensitivity analysis demonstrates that except for temperatures of cooling water, returned chilled water, and temperature difference of driving steam from solar unit, other parameters have positive impact on exergo-economic performance.