CCI Switzerland has won a contract worth USD 3.65 million to supply complete turbine bypass systems for the first two 800-MW fossil-fired units at the new Yong Hueng Power Plant in South Korea. These are Kepco’s first 800-MW supercritical pressure units. The order includes the complete HP and LP turbine bypass system, hot and cold reheat safety valves, and a single bypass control system for each unit that is designed to control both LP and HP turbine bypass operation. Each of the four HP inbody-de-superheating bypass valves are designed for rated flow of 605 mt/hr (1,300,000 lb/hr) with an inlet pressure of 250 BARG (3827 psig) and a controlled, ?P of over 200 BAR (2900 psi) at 569 C (1057 F). In addition to this, all control valves are operated by CCI’s own hydraulic actuation system. The CCI AV6+ control system is an independent control element that serves to co-ordinate the boiler and turbine operation during start-up, shutdown, and load disturbances. Thus the severe stresses inherent with turbine bypass operation, especially required or accurate steam de-superheating, are minimised, assuring long valve and associated piping life.
