中文摘要：

蒸汽喷射器是一种汽液直接接触换热设备,具有体积紧凑、换热强度大等优点,在现代工业中有着很好的应用前景.但是,由于其混合腔内汽相与液相直接接触凝结过程的不稳定性,会造成装置运行时产生较大的噪音和振动,不仅形成环境污染且危害设备安全,限制了该装置的进一步推广.本文针对有限通道内蒸汽射流凝结所引起的压力振荡特性进行实验研究,揭示噪音与振动产生的机理,为蒸汽喷射器的设计与运行提供实验指导.实验获得了进汽质量流率150~600 kg/m~2 s、进水质量流率6×10~3~18×10~3 kg/m2 s、进水温度15~40℃下通道内的动态压力信号,同时采用高速摄像机捕捉汽液相界面的行为和凝结流型.结果表明：根据汽液相界面的行为特征可以将流型分为两大类——不稳定流型和稳定流型.对通道内动态压力的振荡强度特性进行研究,发现随着进水质量流率增加,压力振荡强度在稳定流型区变化不大,但是在进入不稳定流型区以后迅速增大;随着蒸汽质量流率增加,振荡强度在不稳定流型区内逐渐增加,进入稳定流型区后迅速降低,然后在稳定流型区内再次增加;随着过冷水温度的升高,振荡强度在整个流型区域内缓慢增加.

英文摘要：

Steam jet injector is a prospective device with advantages of impact volume, strong heat transfer, without moving part, which can be applied in various industrial fields such as nuclear/conventional power plant, heat-supply system and heat recovery system, etc. However, as the steam jet injector is driven by high speed steam jet condensation in subcooled water flow in the mix chamber, the instability of steam-water direct contact condensation will lead to loud noise and severe vibration. Thus, loud noise will evolve into environmental pollution, and vibration will endanger the equipment, which prevent the promotion of this device in induatrial applications. Moreover, the published works generally involved in the pressure oscillation caused by steam jet condensation in large space water pool, where the water was considered to be stagnant. However, the case becomes more complex when direct contact condensation occurs in a confined channel like in a steam jet injector, where the effect of turbulence on water side and wall can not be ignored. Thus, the reported results can not be applied in the present condition. So it is necessary to study the mechanism of the instability of steam-water direct contact condensation in a confined channel. In this paper, experimental investigation was performed on the amplitude characteristics of pressure oscillation caused by direct contact condensation in a confined channel, aiming at revealing the mechanism of noise and vibration and providing some guidance for the design and operation of the steam jet injector. In order to better observe the behavior of the steam-water interface, a special visualized test section was designed and a high speed camera was applied. The dynamic pressure data was obtained by a dynamic pressure transducer arranged on the wall of channel. Three main inlet parameters, including steam mass flux, water mass flux and water temperatures were tested in the ranges of 150–600 kg/m~2 s, 6×10~3–18×10~3 kg/m~2 s and 15–40°C, respectively. The results indica