Till now, little research on wet steam in steam-water jet technology has been reported. But to a large extent, low pressure steam used in industry is of certain dryness. Therefore, a set of experimental apparatus was designed by using wet steam as working medium, and a multi-nozzle steam-water ejector was used as the experimental device. The influence of steam pressure and steam dryness and discharge pressure on the performance of the multi-nozzle ejector was analyzed. As can be seen from experimental results, the translation of the curve describing the relation between steam mass flow rate and steam pressure was caused by steam dryness. Entrainment ratio increased with steam dryness. Both entrainment ratio and steam mass flow rate increased with steam pressure at a low steam pressure. As steam pressure increased, cold water was blocked when the length of steam plume was equal to the distance between nozzle exit and inlet of throat section and entrainment ratio began to decrease, however, the decrease of steam mass flow rate was delayed. In general, entrainment ratio decreased with the increase of discharge pressure, and its rate of decrease changed at different ranges of discharge pressure.%目前汽一液喷射技术中关于湿蒸汽的研究较少,然而在实际工业中,相当一部分低压蒸汽是具有一定干度的湿蒸汽.为此,设计了以湿蒸汽为工作蒸汽的实验台,并采用一种多喷嘴结构的汽-液喷射器作为实验元件,分析了蒸汽压力,蒸汽干度及喷射器背压对其性能的影响.实验结果表明:蒸汽干度使蒸汽质量流量随蒸汽压力变化的曲线平移.喷射系数随蒸汽干度的增大而增大.蒸汽压力较低时,喷射系数和过冷水流量随蒸汽压力的升高而增大,随着蒸汽压力的升高,当汽羽的长度大于喷射器的喉嘴距时,过冷水发生壅塞,喷射系数开始减小,而过冷水流量的减小延迟.总体上,喷射系数随背压的升高而减小,在背压不同的范围内,喷射系数下降的速度有所不同.
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