PAPERS SELECTED FOR THE SYMPOSIUM

• SELECTING THE OPTIMISED PUMP CONFIGURATION AND DRIVE OPTION FOR THE CONDENSATE EXTRACTION AND BOILER FEED PUMPS FOR THE NEW ESKOM SUPERCRITICAL POWER STATIONS

  Willem van der Westhuizen - Pump Consultant, Eskom Enterprises Engineering, Johannesburg, South-Africa

  Abstract Text

  The increasing growth in the Economy and increase in the Power Demand in South Africa, Eskom has embarked on a huge Capital Expenditure to increase the power development. The new power development undertaken for the future includes: Fossil, Nuclear,... show full text »
  Abstract Text

  The increasing growth in the Economy and increase in the Power Demand in South Africa, Eskom has embarked on a huge Capital Expenditure to increase the power development. The new power development undertaken for the future includes: Fossil, Nuclear, Pebble Bed Modular Reactor, Hydro, Open Gas Cycle, Combined Cycle, Wind and Solar Energy. The first two new Supercritical Fossil fired Power Stations Medupi (6 Units, each 650 MW) and Kusile (6 Units, each 800 MW) are presently in the design and construction phase. The condensate extraction pumps and boiler feed pumps are two of the highest auxiliary power consumers within a power station. It is therefore of utmost importance to select the correct optimised pump configuration and drive option for both these pumps. The paper describes how the final selection for the two new Supercritical Power Stations, Condensate Extraction Pumps was made. The option of a vertical versus a horizontally positioned pump, based on an Air Cooled Condenser was considered. Both Condensate Extraction Pumps are each sized for 100% bypass operation. The paper discusses why two 100% duty pumps were selected with one being variable speed electrical driven and the standby one fixed speed electrical driven. The two new Supercritical Power Stations also opted for a 3 x 50% boiler feed pump configuration to be installed to achieve the high required plant availability. The paper also discusses four different variable speed boiler feed pump drive options that were available for selection. The details of each variable speed drive option are included and discussed. The final decision in selecting the optimsed Boiler Feed Pump drive was based on an economic evaluation model that included three different modes of operation, i.e. (Base Load, Load Following and Two Shifting), initial capital cost and Auxiliary Power Consumption – (Boiler feed pump set efficiency) over the 50 year life time of the power station. (Eskom is the South-African Power utility and is the fifth largest electricity utility in the world and supplies 99% of South-Africa’s power and 55% of the power generated on the African Continent) « hide
  Symposium Session: Thermal, hydro, wind and other Power Plants | Eksploatacioni problemi termo, hidro, vetro i drugih elektrana