A Study on the Flow Characteristic of surroundings of the Extracting Nozzle for Shell Wall Thinning of a Feedwater Heater

고압형 급수가열기 동체 감육 완화를 위한 추기노즐 주변의 유동특성 연구

Several nuclear power plants in Korea have experienced wall thinning damage in the area around the impingement baffle-installed downstream of the high pressure turbine extraction stream line inside number 5A and 5B feedwater heaters. At that point, the extracted steam from the high pressure turbine is two phase fluid at high temperature, high pressure, and high speed. This paper describes operation of experience and numerical analysis composed similar condition with real high pressure feedwater heater. This study applied several impingement baffle plates to feedwater heater same as previous study. In addition, it shows difference of pressure distribution and value between single phase and two phase based on experience and numerical analysis.