摘要
为探究各操作变量对系统最优排气压力的影响,基于MATLAB平台建立了系统仿真模型,分析了特定工况下,在有、无中间换热器的情况下,系统各变量对系统COP(制热性能系数)的影响,确定了影响系统最优排气压力的主要因素,并拟合了相应的关联式。同时利用跨临界CO_(2)热泵系统实验台,在不同蒸发温度与气冷器出口温度条件下研究了排气压力对系统性能的影响,得到不同工况对应的最优排气压力值,并与最优排气压力仿真值进行对比验证。结果表明:系统存在最优排气压力,使得系统COP在此压力下达到最大值;加入中间换热器以后,系统COP有所增加,但最优排气压力几乎不变;高的干度、过热度对系统COP的影响很小,系统COP随着气冷器出口温度的升高急剧下降,随蒸发温度的升高而增大,最优排气压力主要与气冷器出口温度和蒸发温度有关;实验得到的系统最优排气压力值与仿真值的最大相对误差为3%,仿真拟合的最优排气压力关联式与实际运行过程匹配良好。
To explore the impact of operating variables on the system optimal exhaust pressure,the influence of the system simulation model was built based on the MATLAB platform. It analyzed the specific conditions,in the presence of the heat exchanger in the middle of the case,the system would effect COP of the system,the variables to determine the main factors affecting the optimal exhaust pressure system,and fitting the corresponding correlations. At the same time,the influence of exhaust pressure on the system performance was studied under different evaporation temperature and air cooler outlet temperature by using the cross-critical CO2 heat pump system test platform. And the corresponding optimal exhaust pressure value under different working conditions was obtained,which was verified by comparison with the simulation value of optimal exhaust pressure. The results show that there was an optimal exhaust pressure in the system,and COP of the system could reaches the maximum under this pressure. With the addition of intermediate heat exchanger,COP of the system increased somewhat,but the optimal exhaust pressure was almost unchanged. High dryness and superheat had little effect on COP of the system. COP of the system decreased sharply with the increase of the outlet temperature of the air cooler,and increased with the increase of the evaporation temperature. The optimal exhaust pressure was mainly related to the outlet temperature of the air cooler and the evaporation temperature.The maximum error between the optimal exhaust pressure obtained by experiment and that obtained by simulation was 3%,the correlation formula of optimal exhaust pressure fitted by simulation was well matched with the actual operation process.
作者
王迪
王定标
杨雨燊
刘鑫鑫
向飒
WANG Di;WANG Dingbiao;YANG Yushen;LIU Xinxin;XIANG Sa(School of Mechanical and Power Engineering,Zhengzhou University,Zhengzhou 450001,China;Engineering Research Center of Thermal Energy System Energy Saving Technology and Equipment Energy Saving Technology and Equipments in Thermal System of Ministry of Education,Zhengzhou University Zhengzhou 450001,China)
出处
《郑州大学学报（工学版）》
CAS
北大核心
2021年第4期33-39,共7页
Journal of Zhengzhou University（Engineering Science）
基金
国家自然科学基金资助项目(21576245)。
