【摘要】 干燥工艺在工、农业生产中被广泛使用但耗能巨大，通过CO₂热泵干燥技术有望降低其能耗并减缓环境问题。文中在CO₂跨临界基本热泵干燥系统的基础上，提出CO₂跨临界复叠式热泵干燥系统和CO₂跨临界双级压缩并联加热热泵干燥系统。并且通过建立热力学模型将其最优性能系数C_OPh和单位能耗除湿率R_SME与R134a双循环热泵干燥系统进行了比较。研究发现，它们相较于CO₂基础系统性能均有提升，尤其是双级并联加热系统，其C_OPh与R_SME均超过R134a系统。进一步的分析显示，增加蒸发温度、降低气冷器出口温度对CO₂跨临界热泵干燥系统的性能提升起到了关键作用。此外，文中也探究了补气系数和干燥出风温度对CO₂跨临界热泵干燥系统的影响。研究结果表明：经过优化改进的CO₂跨临界热泵干燥在高效节能方面表现出色，展现了替代R134a热泵干燥系统的潜力，同时也为解决干燥工艺高能耗的问题提供了创新性和可行性的解决途径。更多还原

【Abstract】 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 C_OPh and specific moisture extraction rate R_SME 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 C_OPh and R_SME. 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.更多还原