带喷射器的跨临界CO_(2)热泵系统性能分析  

Performance analysis of trans-critical CO_(2) heat pump system with ejector

作　　者：牛擎宇 关欣[1] 秦陶 宋子晔 NIU Qingyu;GUAN Xin;QIN Tao;SONG Ziye(College of Energy and Power Engineering,University of Shanghai for Science and Technology,Shanghai 200093,China)

机构地区：[1]上海理工大学能源与动力学院,上海200093

出　　处：《流体机械》2022年第12期93-100,共8页Fluid Machinery

基　　金：国家自然科学基金面上项目(21978171)。

摘　　要：为了提升跨临界CO_(2)热泵系统的性能,利用喷射器替代节流阀植入系统中,在保证喷射器效率的前提下,对系统中各参数之间的相互影响进行了分析,通过建立SEC系统的热力学模型,分析了气冷器CO_(2)出口温度、排气压力、蒸发温度等参数对系统制热系数COPh的影响。结果表明:气冷器CO_(2)出口温度是决定常规系统引入喷射器是否有益的关键,随着排气压力(7~10 MPa)变化,气冷器CO_(2)出口温度(30~55℃)存在一转换温度,只有当出口温度小于转换温度时才有助于提升COPh。同时为了保证系统的安全与运转正常,气冷器CO_(2)出口温度在低于安全值(57℃)的前提下,还应不超过其转换温度。本文进一步研究了增加回热器对提升SEC的热力性能的效果,结果表明,在气冷器CO_(2)出口温度大于31℃时在SEC系统中加入回热器可以有效提升热泵系统的制热性能。In order to improve the performance of Trans-critical CO_(2)heat pump system,the ejector was implanted into the system instead of throttle valve.On the premise of ensuring the efficiency of ejector,the interaction between various parameters in the system was analyzed.By establishing the thermodynamic model of SEC system,the effects of CO_(2)outlet temperature,exhaust pressure and evaporation temperature of gas cooler on the heating coefficient COPh of the system were simulated and analyzed.The results show that the CO_(2)outlet temperature of the gas cooler is the key to determine whether it is beneficial to introduce the ejector into the conventional system.With the change of exhaust pressure(7~10 MPa),there is a conversion temperature in the CO_(2)outlet temperature of the gas cooler(30~50℃),which is helpful to improve COPh only when the outlet temperature is less than the conversion temperature.Meanwhile,in order to ensure the safety and normal operation of the system,the CO_(2)outlet temperature of the gas cooler shall not exceed its conversion temperature on the premise that it is lower than the safe value(57℃).The effect of adding a regenerator on improvement of the thermal performance of SEC system with ejector was further studied.The results show that adding a regenerator to the SEC system can effectively improve the heating performance of the heat pump system when the CO_(2)outlet temperature of the gas cooler is greater than 31℃.

关 键 词：转换温度 喷射器 跨临界CO_(2)热泵 回热器 

分 类 号：TH12[机械工程—机械设计及理论]