Drying processes are widely used in industrial and agricultural production,but suffer from high energy consumption.CO2 heat pump drying technology offers potential for energy reduction and environmental benefits.Based on the basic CO2 transcritical heat pump drying system,two new systems were proposed:a CO2 transcritical cascade heat pump drying system and a CO2 transcritical dual-stage compression parallel heating system.By establishing a thermodynamic model,their optimal performance coefficients COPh and specific moisture extraction rate RSME were compared with the R134a dual-cycle heat pump drying system.Performance improvements were found in both systems compared to the CO2 basic system,especially the dual-stage parallel heating system which exceeded the R134a in COPh and RSME.Further analysis indicates that increasing evaporation temperature and reduced gas cooler outlet temperatures play crucial roles in enhancing the performance of the CO2 system.Additionally,the impact of make-up air coefficient and drying outlet temperature on these CO2 systems was also examined.Overall,the research demonstrates that the optimized CO2 transcritical heat pump drying systems show excellent efficiency and energy-saving potential,presenting a viable alternative to the R134a system and offering innovative and feasible solutions to the high energy consumption issues in drying processes.
关键词
CO2临界循环/热力学分析/最优性能/热泵干燥
Key words
CO2 transcritical cycle/thermodynamic analysis/optimal performance/heat pump drying
万方数据