同时供冷供热双级压缩制冷热泵循环系统㶲分析

Exergy Analysis on Circle System of Two-stage Compression Refrigeration Heat Pump with Function of Simultaneous Heating and Cooling

同时供冷供热双级压缩制冷热泵循环是1种新型热力循环,它能够同时对制冷、制热量进行调节,以满足用户的冷热量需求。本文建立了该循环系统的分析模型,并对其进行了研究,结果表明:在给定的传热温差下,影响该系统效率的主要因素是室外空气温度、制冷剂流量比;在低制冷剂流量比下,该系统产生损失的主要部位依次为热源侧换热器、热水加热器、第一节流阀、高压压缩机;在高制冷剂流量比下,该系统产生损失的主要部位依次为第二节流阀、热水加热器、高压压缩机、低压压缩机。通过在系统中增加1个经济器对该系统进行了优化,并对比分析了系统优化前后的效率和损失,结果表明:经济器能提高系统的效率,大幅度降低发生在第一节流阀和第二节流阀的损失,但对其他部件损失的影响很小。

Circle of the two-stage compression refrigeration heat pump with the function of simultaneous heating and cooling is a new thermodynamic cycle,which can meet the consumer＇s demand for cool and heat capacity with the simultaneous adjusting on the cooling and heating capacity. This paper sets up the exergy analysis model of the circle system and then conducts the research on it,which shows that： under the heat transmission temperature difference given,the main factors effecting the exergy efficiency of the system are the outdoor air temperature and the refrigerant flow ratio; with low refrigerant flow ratio,the main parts of the system producing exergy losses are heat exchanger of the heat source side,hot water heater,the first throttle valve and high pressure compressor in sequence; with high refrigerant flow ratio,the main parts of the system producing exergy loss are the second throttle valve,hot water heater,high pressure compressor and low pressure compressor in sequence. Optimized the system by adding an economizer,and then analyze the exergy efficiency and the exergy loss comparatively before and after optimization,the result shows that： economizer can improve the system＇s exergy efficiency and reduce the exergy loss occurred in the first and second throttle valve substantially,but have little effect on other parts.