摘要: |
采用高效的热泵系统替代常规锅炉是实现“双碳”目标的有效措施。本文提出采用引射器实现双温蒸发的CO2热泵系统,以实现余热梯级利用和高效制热。通过窄点分析法,建立了基本CO2系统、CO2引射器系统、双温蒸发CO2引射系统的热力学模型,发现双温蒸发系统存在最优排气压力及最大COP。基于最优工况进行分析,结果表明:在热泵热水器名义工况下,双蒸发器系统COP最高达4.84,比基本CO2热泵系统提高了9.88%。双温蒸发过程可显著降低吸热过程中的换热不可逆损失,双温蒸发系统蒸发器侧的不可逆性能指数为1.51,比基本CO2和带有引射器的常规CO2系统降低了24.50%。 |
关键词: 热泵系统 CO2 引射器 温度匹配 双温蒸发 不可逆损失 |
DOI: |
投稿时间:2021-10-08修订日期:2021-10-22 |
基金项目:国家自然科学基金(51806151);天津市自然科学基金(20JCQNJC00600);食品冷链装置节能及储运新技术创新团队项目(TD13-5088) |
|
Performance Analysis of CO2 Dual-temperature Evaporation Heat Pump System with an Ejector |
Li Xiaoyan,Dai Baomin,Hua Xue,Liu Chen,Liu Shengchun |
(Foreign Environmental Cooperation Center, Ministry of Ecology and Environment;Tianjin Key Laboratory of Refrigeration Technology, Tianjin University of Commerce) |
Abstract: |
Replacing conventional boilers with an efficient heat pump system is an effective solution to achieving “carbon peaking and carbon neutrality”. In this study, a CO2 heat pump system adopting an ejector to realize dual-temperature evaporation is proposed for cascade utilization of waste heat and high-efficiency heating. Thermodynamic models of the baseline CO2 system (Base), conventional CO2 ejector system (Ej-Evap1), and CO2 ejector system with dual-temperature evaporation (Ej-Evap2) are developed based on the pinch method. The maximum coefficient of performance (COP) is achieved at the optimum discharge pressure for the dual-temperature evaporation system. Under the optimum working conditions, the results show that the maximum COP of the Ej-Evap2 system under nominal conditions is 4.84, which is 9.88% higher than that of the base. Double-temperature evaporation can significantly reduce the heat transfer irreversibility loss in the heat absorption process. The irreversible performance index of Ej-Evap2 during the evaporator process is 1.51, which is 24.50% lower than that of the base and Ej-Evap1 systems. |
Key words: heat pump system CO2 ejector temperature matching dual-temperature evaporation irreversibility loss |