高低压差对冷水机组性能影响的实验分析  

Experimental analysis on influence of pressure difference on water chilling unit performance

作　　者：张姗[1] 李垒[1,2,3] Zhang Shan;Li Lei(University of Zaozhuang,Zaozhuang 277160,China;University of Shanghai for Science and Technology,Shanghai 200093,China;Shanghai Key Laboratory of Multiphase Flow and Heat Transfer in Power Engineering,Shanghai 200093,China)

机构地区：[1]枣庄学院,枣庄277160 [2]上海理工大学,上海200093 [3]上海市动力工程多相流动与传热重点实验室,上海200093

出　　处：《低温与超导》2020年第11期59-63,96,共6页Cryogenics and Superconductivity

基　　金：国家自然科学基金(51275152和51875167);上海市动力工程多相流动与传热实验室开放基金(13DZ2260900);河北省自然科学基金(2018202114)资助。

摘　　要：基于现有设备,对冷水机组性能受高低压工况的影响进行实验分析。实验运行中,膨胀阀前过冷度、压缩机吸气过热度、换热器水源换热温差保持恒定,通过调节换热器水源温度、流量对蒸发温度、冷凝温度进行控制。实验结果显示:高低压差<1800 kPa时,工质流量受压差影响较小,高低压差>1800 kPa时,工质流量随压差的增大几乎呈线性减小;蒸发器入口干度随压差的增大而增大,两者几乎呈线性正比关系,而蒸发器进口干度与蒸发温度呈负相关;在各实验变量对工质流量、换热器水源流量的影响下,装置制冷量、COP均随压差的增大而减小、随蒸发温度的增大而增大;综合各实验变量对换热器换热效果、换热量的影响,蒸发器换热温差、冷凝器换热温差同样随压差的增大而减小、随蒸发温度的增大而增大。Influences of pressure difference on water chilling unit performance was experimentally analyzed based on the existing equipments.Sub-coold temperature at the inlet of thermostatic expansion valve,superheat degree at the inlet of compressor,water source heat transfer temperature difference of the heat exchanger kept all constant,and evaporation temperature and condensation temperature were controlled by adjusting the water source temperatures and flow rates in the heat exchanger.The experimental results show that the pressure difference has less influence on working medium flow rate when pressure difference is less than 1800 kPa,while working medium flow rate decreases linearly with increasing the pressure difference when pressure difference is more than 1800 kPa;vapor quality at the evaporator inlet increases with increasing the pressure difference,and their relationship is almost linear proportional,while vapor quality at the evaporator inlet is negatively correlated with evaporation temperature;refrigerating capacity and COP all decrease with the increase of pressure difference and increase with the increase of evaporation temperature under influences of various experimental variables on working medium flow rate and water flow rate of the heat exchanger;the temperature differences of evaporator and condenser all decreases with increasing pressure difference and increases with increasing evaporation temperature,based on influences of various experimental variables on heat transfer characteristics and heat exchange amount.

关 键 词：热力膨胀阀 压差 工质流量 入口干度 制冷量 COP 换热温差 

分 类 号：TB65[一般工业技术—制冷工程]