Experimental and numerical investigation of two phase ejector performance with the water injected into the induced flow

• Published in: International Journal of Advanced Nuclear Reactor Design and Technology 2020, Vol.2, p.15-24
• Main Authors: Chen, WeiXiong, Huang, ChenXi, Bai, YuPing, Chong, DaoTong, Yan, JunJie, Liu, JiPing
• Format: Article
• Language: English
• Subjects: Entrainment ratio; Pressure ratio; Two phase flow ejector
• ISSN: 2468-6050; 2468-6050
• DOI: 10.1016/j.jandt.2020.01.001

When injectors are used in petroleum industries or sea water desalination system, it is a special case that the induced gas is accompanied by water, the ejector is in two-phase operation. In the present study, the ejector performance at two phase flow is investigated experimentally and numerically. The results indicate that: the entrainment ratio would decrease when the water is injected into the induced flow, as well as the pressure ratio. The maximum decrement of entrainment ratio is around 40.5% at sub-critical mode when the motive pressure is 1.0 MPa, the induced pressure is 0.2 MPa, liquid-air ratio is 22%. For the pressure ratio, the maximum decrement is 62.5% when the motive pressure is 1.0 MPa, the induced pressure is 0.5 MPa, liquid-air ratio is 2.87%. However, the lower the induced pressure is, the more obvious the effect of mass flow rate on entrainment rate is, while the effect on pressure ratio is just opposite. Moreover, the performance becomes worse in sub-critical mode than that in critical mode. The effect of NXP on ejector performance also has been analyzed. There exists an optimum NXP whether the two phase flow ejector is in critical mode or sub-critical mode. The optimum NXP for entrainment ratio enlarges from 3.6 mm to 4.4 mm with the increase of water mass flowrate, and is bigger than that of single phase ejector (the optimum NXP is 2.8 mm). This study may provide a beneficial reference for the operation of supersonic ejectors on two phase flow.