System Performance Optimization Study On Power Generation System For Cold Energy Recovery Of Cold Storage Building

Our country is in a period of rapid economic growth and rapid urban construction,with the consequent increase of building energy consumption.At present,the building energy consumption accounts for about 20% of the total energy consumption of the whole society.Promoting building energy conservation and green building development plays an important role in reducing national energy resource consumption and protecting ecological environment.Through the development,production and promotion of various technology and measures of improving energy efficiency is an effective method to reduce building energy consumption,energy saving technology and applications in construction,under the impetus of the technology innovation application form "energy-saving" construction mode.Cold storage building as a typical commercial low-temperature storage building because of its low temperature,compared with other commercial buildings energy consumption.The fresh industry in our country,with the rapid development of cold storage building scale increases year by year,but the cold storage refrigeration system to the influence of the preservation process,or system process design,make its in use process will be accompanied by large emissions of cold energy.In this paper,based on the cold storage architecture as the research object,combined with the use of cold storage building characteristics and requirements of cold storage refrigeration system preservation technology,the advanced organic Rankine's cycle power generation technology applications in the cold energy and cold storage architecture.Through systematic research,the energy saving potential of cold storage building is explored.In this paper,the research content mainly includes three aspects: cold storage building cold energy recovery power generation performance optimization numerical simulation research,the cold storage building cold energy recovery power generation system performance experiment and intermediate cooling of air cold expansion refrigeration system research of the influence of the electric power plant performance.First,taking the "waste cold" recovery power generation based on the cold storages which at the high temperature(0?),low temperature(-18?)and ultra-low temperature(-56?)as examples,this paper uses numerical simulation to analyzes how different heat source temperature affects the performance parameters of cold energy recovery ORC system.The best optimized parameters of the system in the case of evaporative condensation coupling were obtained using the evaporative condensation coupling characteristic analysis method,so as to provide a more accurate theoretical data for the further optimization of the control parameters.Secondly,based on the optimization of performance of cold energy recovery ORC system,a 500 W cold energy recovery power generation system was built and picked R245 fa as the working fluid,the heat transfer characteristics of the evaporator and the condenser,system thermal efficiency and exergy efficiency were studied under the condition of 0 ? exhaust air.The results show that the irreversible loss of the components,the system thermal efficiency,exergy efficiency and the expander effieiency are monotonically increasing with the increase of the evaporation temperature of the system.Compared with the numerical simulation,the trend of parameters' change are basically the sameFinally,in order to further improve the integrated performance of compressed air expansion refrigeration system,this paper proposes a compressed air expansion cold power production system combined with intermediate cooling.The results show thatunder the same pressure ratio,the increase of the ambient temperature makes the energy consumption of the air compressor increase,while the inevitable loss of the air compressor decreases.The output power of the air expander is mainly affected by the temperature drop ?t between the outlet of the compressor and the inlet of the expander.Under the same temperature drop ?t,with the increase of the ambient temperature,the difference between the net power consumption and the air compression refrigeration system increases gradually and the ratio ranges from 0.49 to 1.63.When the temperature drop ?t> 36 ?,the air expander is better than air compression refrigeration system,and the air expander outlet temperature can be adjusted by controlling the temperature drop ?t.