摘要
建立涡旋膨胀机的变工况数学模型,以R245fa为工质分析进气压力、工质过热度及膨胀机转速对膨胀机变工况特性的影响规律。结果表明,进气压力偏离额定压力时,膨胀机容积效率的变化较小,而等熵效率随进气压力的增大呈现先增大后降低的趋势,最大变化率为25%。相比等熵效率为常数的理想情况,变工况时膨胀机的轴功率平均降低15%。工质进气过热度对膨胀机性能的影响较小。随着转速的升高,膨胀机的轴功率、等熵效率及容积效率都增大,变工况运行中需要对膨胀机转速进行调节。
A mathematic model for a scroll expander was developed.Based on this model,off-design performance at different inlet pressure,temperature and rotate speed of turbine was conducted.The results show that there is little change of volumetric efficiency at different inlet pressure.However,isentropic efficiency firstly increases and then decreases with the inlet pressure,when inlet pressure ranges drops 25%.The shaft power in off-design condition will drop 15%compared with the ideal condition which remains a constant isentropic efficiency.Besides,superheated temperature of working fluid has little effect on the scroll expander performance.The shaft power,isentropic efficiency and volumetric efficiency all increases with rotate speed of scroll expander.Consequently,rotate speed should be adjusted in off-design condition.
作者
刘海伦
王志奇
刘湘杰
何金鑫
雷峻源
LIU Hai-lun;WANG Zhi-qi;LIU Xiang-jie;HE Jin-xin;LEI Jun-yuan
出处
《节能》
2021年第10期19-22,共4页
Energy Conservation
关键词
涡旋膨胀机
变工况特性
有机朗肯循环
scroll expander
off-design performance
Organic Rankine Cycle
