16-10-2010, 01:59 PM
ADVANCES IN POWER PLANT STEAM BLOW CLEANING ANALYSES
Bechtel Power Corporation
Frederick, Maryland, USA
Paul J. Babel
Bechtel Power Corporation
Frederick, Maryland, USA
Allen T. Vieira
Bechtel Power Corporation
Fredrick, Maryland, USA
ABSTRACT
Steam blows are used prior to initial turbine powering for steam power plants to clear debris and surface scale that could potentially damage turbine blades during plant operation. Based on experience from steam blows for several dozen plants, enhancements have been made to the techniques in the detailed engineering analysis used by plant startup to perform steam blows. This paper discusses these improvements as applied to combined cycle gas and coal power plants. The basis for steam blows is that the piping is blown, bypassing the turbine, with sufficient boiler pressure to ensure that the piping will experience a dynamic pressure to assure adequate cleaning. Typically, the boiler pressures during steam blow provide a dynamic pressure throughout the piping, which is at least 20% higher than would be experienced for all plant operating conditions. Therefore, any potentially damaging particles will be blown out of the piping prior to the turbine operation. The following improvements and enhancements, which are detailed in this paper, have recently been implemented in the analyses used to establish adequate steam blows: 1. Advanced Modeling Techniques 2. Design Coordination with Fast Track Engineering 3. Consideration of Multiple HRSG Plants 4. Analysis Support During Actual Steam Blows (for site engineering and startup)
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http://www.bechtelassets/files/PDF/BIP/29361.pdf