摘要
为研究流体过冷度对喷嘴工作性能的影响,研制了两相流体混合速度的测试装置.基于动量定理,测定两相流体的质量流量和冲击力,从而得到质量平均的流体混合速度.利用R410A制冷系统实验台,实验研究了制冷剂过冷度对喷嘴出口流体混合速度及喷嘴能量转化效率的影响.实验表明:随着入口制冷剂过冷度的提高,喷嘴的通过质量流量逐渐增加;同时,制冷剂过冷度的提高使喷嘴出口流体混合速度及喷嘴转化效率明显下降;在实验工况下,喷嘴进口为饱和制冷剂时,2#喷嘴出口制冷剂混合速度达到了94.1m/s,喷嘴转化效率为64.1%;当制冷剂过冷度由饱和状态增至11℃时,2#喷嘴出口流体的混合速度降低35.7%,喷嘴转化效率降低33.9%.
A velocity-measurement equipment was developed to study the influence of fluid subcooling degree on the nozzle operation performance. The mass flow rate and the impact force were measured and the average mixing velocity of the two-phase fluid was obtained based on the momentum theorem. The influence of fluid subcooling degree on the average mixing velocity of the two-phase fluid at the outlet of LAVAL nozzles and the efficiencies of the nozzles was investigated on a refrigeration system with R410A. The experimental results show that the mass flow rate increased with the increase of the refrigerant subcooling degree at the inlet of the nozzles. However, the increase of upstream subcooling degree resulted in the significant decrease of the refrigerant mixing velocity and the nozzle efficiency. Under test conditions, the refrigerant mixing velocity at the outlet of the nozzle and the nozzle efficiency decreased by 35.7% and 33.9%, respectively, when the upstream subcooling degree increased from 0 ℃ to 11 ℃ for No. 2 nozzle.
出处
《西安交通大学学报》
EI
CAS
CSCD
北大核心
2009年第11期18-21,共4页
Journal of Xi'an Jiaotong University
基金
国家高技术研究发展计划资助项目(2007AA05Z260)
西安交通大学博士学位论文基金资助项目(DFXJTU2005-03)
关键词
制冷
喷嘴
速度
效率
refrigeration
nozzle
velocity
efficiency
