CHARACTERISTICS OF THE STEAM INJECTOR FOR THE STATIC REACTOR COOLING SYSTEMS

摘要

The Steam Injector (SI), which is a simple thermal-hydraulic device, works as a passive pump and a heat exchanger under the direct contact condensation mechanism. From its characteristics, SI is capable to provide coolant to the reactor core continuously by utilizing the reactor steam without any external power sources even during the Station Black-Out (SBO) scenario. In the present work, we evaluated the detail characteristics of SI performances as a passive pump. Experiments were carried out under the following conditions: the flow rates controlled by water supply valve were 0.3～0.6 kg/s; the pressures of the inlet steam controlled by the main steam valve were 0.15 ～ 0.55 MPaG. In addition numerical analysis model was developed using a commercial CFD code, Star-CCM+. From the experimental results, the discharge pressures were about 1.5 times of the inlet steam pressure at given conditions, and it was confirmed that the SI has a performance capability as a passive pump. We also investigated its heat transfer characteristics by calculating the heat transfer coefficients from the inlet and outlet temperatures. It was concluded that the SI has a promising capability as the passive core injection cooling system.