Operating performance and economic analysis of solar single/double-effect compound absorption refrigeration system

Abstract

A single/double-effect compound absorption refrigeration system driven by solar compound parabolic collectors is proposed, which can realize mode switching according to the temperature of the heat source. The mechanism model of the system is established, and the sixth-order state space model of the single-effect mode and the ninth-order state space model of the double-effect mode are obtained through further simplification. The validity of the model is verified. The results showed that compared with the single-effect system and the double-effect system, the cooling capacity and cooling time of the system on sunny days are increased by 20.35 % and 5.34 h respectively; On cloudy days, frequent switching of the system is not conducive to operating; In addition, on overcast days, the system always runs in single-effect mode, and the total daily cooling capacity is small. When the ts (the temperature to switch to single-effect mode) and ts,d (the temperature to switch to double-effect mode) are 85 °C and 135 °C, the daily total refrigerating capacity of the system is 102.85 kWh. Compared with ts is 95 °C and ts,d is 155 °C, the refrigerating capacity is increased by 10.12 %. Finally, the economic analysis of proposed system shows that, compared with the compression refrigeration system, the payback period of the system was11.84 years when COPCRS (coefficient of performance of compression refrigeration system) was 4 and ce was 0.18 USD/kWh. The NPV (net present value) and the IRR (internal recovery rate) of the system were 375.8 USD and 5.39 %, respectively. The system is expected to be used in areas with sufficient solar radiation.