AN INVESTIGATION IN THE DEGISN AND OPERATION OF TURBINE BY-PASS VALVES IN STEAM POWER PLANTS

This paper aims to investigate the design and operation of Turbine By-pass Valves (TBV) in steam power plants & also to compare them in Iran. A "TBV" is in fact a kind of pressure reducing valve, which involves a temperature reduction system, and its duty is to by-pass the turbine's input steam. This valve is used during start-up, as well as to protect the turbine against any possible problem such as increase in steam pressure. so, it prevents the steam to scape or the boiler to be shutdown. There are two types of these valves in power plants, each of them has its own advantages and disadvantages. In this paper, effort has been made to compare the power plant which make use of such valves with those which don't. This comparison consists of differences in operation and turbine protection, control loops and maintenance, and the results are tabulated for better selection.