DEVELOPMENT OF LARGE SIZE MOISTURE SEPARATOR REHEATER FOR UP TO 1700 MW PWR CLASS

摘要

The recent trend in increasing the power generation capacity of pressurized water reactors (PWRs) up to the 1700MW Class for greater economy is met with inherent challenges. Higher generation capacity necessitates turbines with higher efficiency. Operating the high pressure (HP) turbine at higher efficiency requires development of large size moisture separator reheater (MSR) to accommodate the higher specific steam volume due to the reduced HP exhaust pressure. Higher specific volume of steam also results in higher velocities and increased pressure drops. At higher steam velocity, the flow accelerated corrosion (FAC) is enhanced and the moisture separator performance will be deteriorated due to the increased mist carry over across the Chevron type vanes. The development of MSR for up to 1700MW Class PWR involved optimizing the heat balance around the MSR and selecting the optimized size of the MSR for performance and cost. This also included selection of an optimized terminal temperature difference (TTD) for the MSR. Then the newly developed MSR was verified by computational (using CFD) and experimental techniques. Using CFD, the pressure, flow, and velocity distribution, pressure drop, and velocity distribution on the shell surface were analyzed. An experimental set up using actual size sliced model of the MSR was used to predict the separator performance and drainage characteristics. The testing was carried out with two phase air-water flow at atmospheric conditions. This paper summarizes the large size MSRs for up to 1700 MW Class PWR, its development, and design verification.