The Combined Cycle Power Plant (CCPP), one of the largest CCPPs in South Korea, is located in the Gyeonggi Province and has a capacity of 1,900 MW.
The heart of the plant consists of four gas turbines, two steam turbines and generators, all made by Mitsubishi Heavy Industries Ltd.
The six boiler feed water pumps were supplied by a Korean pump manufacturer. Ever since the commissioning of the plant in 2015, the operator was faced with cavitation problems in the Automatic Recirculation Valves (ARV) protecting the pumps.
The main reason for cavitation was the – at times – very low flow rate and, thus, critical load condition of the valves.
Low flow rates often cause cavitation in the AR valves
In CCPPs, a Heat Recovery Steam Generator (HRSG) uses the hot exhaust gases from the gas turbine to evaporate the feed water for the steam turbine cycle.
A pump is operated to make up for feed water of the HP drum, depending on its level controlled by a level control valve/ pressure control valve (LCV/PCV). The valve ensures level control in the boiler drum – the container in the steam generator which is fed by the feedwater pump....
Safe pump operation at partial load
