Abstract
A steam injector has been investigated as one of the most important component of the next-generation reactor. It has a function of a passive pump without large motor or turbo-machinery and its performance as a pump depends on direct contact condensation phenomena between a supersonic steam and a sub-cooled water jet. However the turbulent heat transfer under large shear stress is not enough investigated. Furthermore although it well known that non-condensable gases affect the condensation heat transfer, the effect of the non-condensable gas on the condensation of supersonic steam on high-speed water jet has been not cleared. In the present study the operating characteristic of the steam injector is examined in detail, based on the observation results and measurement results of the temperature and the pressure distribution in the steam injector with non-condensable gas in steam. From experimental results, it is experimentally clearly the flow transient phenomena exist at SI start up period. It is also clarified that discharge pressure is depended on the inlet steam pressure, the inlet water flow rate, the throat diameter and non-condensable flow rate. Finally a heat transfer coefficient is estimated about 0.96 to 1.06 MW/K · m2 without non-condensable gas condition in steam.
