Abstract
A two-phase flow ejector is an important part of a water mist fire suppression system, and these devices have become a popular research topic in recent years. This paper proposes a supersonic ejector that aims to improve the efficiency of water mist fire suppression systems. The effects of ejector geometric parameters on the entrainment ratio (ER) were explored. The effects of primary flow pressure (PP) on the mixing process and flow phenomena were studied by a high-speed camera. The experimental results show that the ER first increases and then decreases with increasing PP. ER increases with increasing ejector area ratio (AR). The PP corresponding to the maximum ER of ejectors with a different nozzle exit position (NXP) is 3.6 bar. The ejector with an NXP of +1 and AR of 6 demonstrate the best performance, and the ER of this ejector reaches 36.29. The spray half-cone angle of the ejector increases with increasing ER, reaching a maximum value of 7.07°. The unstable atomization half-cone angle is mainly due to a two-phase flow pulsating phenomenon. The pulsation period is 10 ms. In the present study, a general rule that provides a reference for ejector design and selection was obtained through experiments.
Highlights
Fire protection, as an important field of social and public security, is closely related to society and everyone involved in the process of national economic development
The experiment was carried out using ejectors with an of 0 but with different area ratio (AR) (2‐6), f mainly to study the effect of the AR on the ejector performance
The experiment was carried out using ejectors with an nozzle exit position (NXP) of 0 but with different ARs (2‐6), 3
Summary
As an important field of social and public security, is closely related to society and everyone involved in the process of national economic development. Studying the complex mixing process of two-phase flow with a high-speed camera is necessary. Many numerical studies have been carried out on the entrainment ratio and velocity field of supersonic ejectors with single-phase flows, experimental studies on two-phase flow ejectors used in water mist fire suppression systems are still lacking. The experimental setup of the two‐phase flow ejector is mainly composed of a gas supply system (air compressor, gasholder, and pressure control valve), a liquid supply system (ball valve, elevated water tank, pump, and storage tank), visualized ejectors with different structural parameters, and a measurement system (high‐speed camera, vortex flowmeter, turbine flowmeter, data acquisition card, and computer). To for obtain relativelyflow dryejector and stable air,for aa the structure design andtransmitter selection ofwith working a two-phase suitable pressure control valve with a filtering water mist fire extinguishing system.accuracy of 5 μm was used.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
