摘要
以单级压缩回热循环的低温冷柜机组为研究对象,采用R290/R170非共沸混合制冷剂,制冷剂质量流量为4.52 kg/h,机组额定制冷量为100 W。采用Aspen Plus V10软件建立系统仿真流程,在冷凝温度为30℃下设置蒸发温度为-65℃,分析非共沸混合制冷剂在4种质量比例(4∶6、5∶5、6∶4、7∶3)下系统运行冷凝压力和蒸发压力的选取,以及压缩机排气温度、制冷量、COP、节流闪蒸率的变化规律,确定较优运行质量比例。结果表明:系统在高冷凝温度下运行,选取R290/R170非共沸混合制冷剂露点、泡点对应的下限压力作为系统运行的冷凝压力和蒸发压力较优;在冷凝温度为30℃下设置蒸发温度为-65℃时,质量比例为6∶4时冷凝压力选取2.07 MPa,蒸发压力选取0.13 MPa较为合适。对于R290/R170非共沸混合制冷剂,低沸点组分占比增大可使系统的制冷量和COP增大,但压缩机排气温度和节流闪蒸率也会增大,在冷凝温度为30℃下设置蒸发温度为-65℃时,质量比例为6∶4时运行效果较优。R290/R170非共沸混合制冷剂在质量比例为6∶4时,冷凝温度为30℃下设置蒸发温度为-65℃时,系统运行性能系数保持在0.23左右,达到了低温制冷系统的平均水平。
Taking a low-temperature refrigerator unit with single-stage compression regenerative cycle as the research object,R290/R170 non-azeotropic mixed refrigerant is adopted,the mass flow of the refrigerant is 4.52 kg/h,and the rated cooling capacity of the unit is 100 W.Aspen PlusV10 software is used to establish the system simulation process,and the evaporation temperature is set to-65℃under the condensing temperature of 30℃.The selection of operating condensing pressure and evaporation pressure of the system under four mass ratios of non azeotropic mixed refrigerant(4:6,5:5,6:4 and 7:3),as well as the variation laws of compressor discharge temperature,refrigeration capacity,COP and throttling flash rate are analyzed,and the optimal operation mass ratio is determined.The results show that when the system operates at high condensation temperature,it is better to select the lower limit pressure corresponding to the dew point and bubble point of R290/R170 non-azeotropic mixed refrigerant as the condensation pressure and evaporation pressure of the system.When the evaporation temperature is set to-65℃at the condensation temperature of 30℃,and the mass ratio is 6:4,it is more appropriate to select 2.07 MPa as the condensation pressure and 0.13 MPa as the evaporation pressure.For R290/R170 non-azeotropic mixed refrigerant,the increase of the proportion of low boiling point components can increase the refrigeration capacity and COP of the system,but the compressor discharge temperature and throttling flash rate will also increase.When the evaporation temperature is set to-65℃at the condensation temperature of 30℃,and the mass ratio is 6:4,the operation effect is better.When the mass ratio of R290/R170 non-azeotropic mixed refrigerant is 6:4,and the evaporation temperature is set to-65℃at the condensation temperature of 30℃,the COP of the system is maintained at about 0.23,reaching the average level of low-temperature refrigeration system.
作者
张海旭
杨丽
王强
谭明辉
宋胜飞
ZHANG Haixu;YANG Li;WANG Qiang;TAN Minghui;SONG Shengfei
出处
《煤气与热力》
2021年第10期7-11,15,V0041,共7页
Gas & Heat
基金
山东省重点研发计划项目——基于分层射流送风的低温空气源热泵热风机系统优化研究(2019GGX103013)。
