Streamlining the start-up of thermal stations
Presented by SUEZ Energy Generation NA
CONTEXT
The pipe work of boilers in thermal stations must be cleaned before the initial start up in order to remove any dirt, rust or silica. Until now, SEGNA has followed a four-stage procedure, the last stage of which used high-pressure steam to set the combustion turbine in motion. The results consisted of high costs and loss of time caused by the use of a large volume of fuel, many operating hours and many start-ups of the turbine.
INNOVATION
In the new cleaning procedure, only the first three stages are necessary (injection of pressurized water, then pressurized nitrogen and, lastly, polishing with demineralized water). In order to check the validity of this system, during the start up of the thermal station at Hot Springs, Arkansas, en 2005, we maintained the last stage, but reduced the number of start-ups of the combustion turbine. In light of the success we achieved, the fourth stage utilizing high-pressure steam was totally eliminated at the Choctaw, Mississippi, gas-powered station that was launched in 2006.
RESULTS
At both power stations, the new cleaning procedure generated an overall savings of $17.3 million and both were able to startup more rapidly. As a result, Choctaw had a gain of eight weeks. This innovation also requires less equipment and fuel. Another obvious benefit is greater environmental protection. This cleaning procedure developed by SEGNA is directly usable by other SUEZ ubsidiaries that build thermal plants.
