Exergoeconomic Analysis And Optimized Design Of Solar Absorption-subcooled Compression Hybrid Cooling System

With the rapid development of economy,energy shortage and environmental pollution become more outstanding.Developing the solar absorption cooling system is helpful to reduce the energy consumption of air conditioning and for the sustainable development of society.Solar/natural gas-driven absorption chiller,solar vapor absorption–compression integrated refrigeration system with parallel configuration and solar absorption-subcooled compression hybrid cooling system are considered as three potential solutions for multi-storey building cooling.Owing to there are evident differences in their investment costs and thermodynamic performances,it is necessary to comprehensive evaluate the thermoeconomic performance of above systems.In addition,the design criteria of the novel and effective system,i.e.,solar absorption-subcooled compression hybrid cooling system has not been studied deeply.Therefore,this paper mainly compares the thermoeconomic performance of above three systems,and researches the effect of important design parameters for solar absorption-subcooled compression hybrid cooling system.The comparison result shows that the solar absorption-subcooled compression hybrid cooling system owns the lowest exergy destruction,fuel and product cost flow rates when the configuration is applied to single-storey to ten-storey buildings in Guangzhou or four-storey to ten-storey buildings in Turpan.Therefore,it has the highest potentiality in building cooling.In addition,the cooling capacity of absorption subsystem,the condenser temperature,the evaporator temperature of compression subsystem,and the isentropic efficiency of compressor are considered as the most important parameters for the design of solar absorption-subcooled compression hybrid cooling system based on the fixed design condition.When the configuration is applied in high-rise buildings,the size of absorption chiller should be designed based on the maximum collector area.While the size depends on both the local solar irradiance and the building cooling demand when the configuration is used in low-rise buildings,and the optimal sizes based on the lowest relative cost difference or product cost flow rate show significant difference.As for the low-rise building cooling design based on the entire working condition,the moderate size of absorption chiller is benefit to obtain the lowest product cost flow rate when the temperature of hot water mainly changes within 75-90 °C,while the small scale is more appropriate if the design is assessed by the relative cost difference.As for the configuration applied in high-rise buildings,the larger size of absorption chiller or condenser of compression chiller are both recommended based on the entire working condition design.Specially,the design criteria of the evaporator scale and the isentropic efficiency of compressor in compression chiller are consistent for high-rise buildings and low-rise buildings.This paper is helpful to improve the thermoeconomic efficiency of solar absorption-subcooled compression hybrid cooling system,and promote the development of its design theory.