Performance assessment of a single/double hybrid effect absorption cooling system driven by linear Fresnel solar collectors with latent thermal storage

Coupling with a single/double hybrid effect (SDHE) absorption system could cut down the investment cost and increase significantly the average coefficient of performance. A hybrid solar hybrid cooling system, composed of linear Fresnel reflector (LFR) solar collector arrays, a single/double hybrid effect (SDHE) absorption chiller, a thermal storage tank stored the intermediate-temperature HITEC molten salt, and complementary components, was investigated both theoretically and experimentally in this paper. Based on the weather data of typical meteorological year, dynamic mathematical models coupled with different operation modes have been developed and were validated with the experimental results of each component. The objective of this paper is to theoretically analyze the complicated dynamic behaviors of LFR solar collector, SDHE absorption chiller, and the entire solar cooling system. Experimental results show the SDHE absorption chiller can obtain thermal COP from 0.73 (single effect) to 1.09 (double effect) when the inlet temperature of hot water increased from 141.5 °C to 155.4 °C. Considering the same weight coefficient of cooling capacity, solar fraction, and thermal COP on seasonal performance, the optimized region of collecting area and thermal storage capacity are within the ranges of 900-1100 m2 and 5-8.5 m3, respectively. The optimized concentration ratio of 30 is determined based on the second law of thermodynamics and the rated parameters of the SDHE chiller. Finally, the optimized solar cooling system can provide the average seasonal cooling capacity of 102 kW, the seasonal thermal COP of 0.88, and the seasonal solar fraction of 27.2% in typical meteorological summer conditions of Shanghai.