Performance comparison and analysis of a combined power and cooling system based on organic Rankine cycle

摘要

A novel power and cooling system combined system which coupled organic Rankine cycle (ORC) with vapor compression refrigeration cycle (VCRC) was proposed.R245fa and butane were selected as the working fluid for the power and refrigeration cycle,respectively.A performance comparison and analysis for the combined system was presented.The results show that dual-pressure ORC-VCRC system can achieve an increase of 7.1％ in thermal efficiency and 6.7％ in exergy efficiency than that of basic ORC-VCRC.Intermediate pressure is a key parameter to both net power and exergy efficiency of dual-pressure ORC-VCRC system.Combined system can produce maximum net power and exergy efficiency at 0.85 MPa for intermediate pressure and 2.4 MPa for high pressure,respectively.However,superheated temperature at expander inlet has little impact on the two indicators.It can achieve higher overall COP,net power and exergy efficiency at smaller difference between condensation temperature and evaporation temperature of VCRC.