LM2500 to LM2500+DLE Gas Turbine Combinedcycle Plant Repowering

摘要

The province of Alberta, Canada developed annual emission intensity limits for the power generation sector in order to preserve air quality by reducing emissions of sulfur dioxide (SOx), nitrogen dioxide (NOx), and primary particulate matter. Effective January 1, 2006, all new gas fired power plants were required to meet Annual Emission Intensity Limits for NOx. In the Spring of 2006, the City of Medicine Hat (COMH) LM2500 gas turbine units were due for their 50,000-hour major overhaul cycle, and COMH was faced with this new NOx emission requirement, along with an increasing power load demand for the city. Working closely with GE Energy’s Aero Services group, COMH decided to upgrade the two LM2500 gas turbines to two LM2500+DLE gas turbines to meet the new emissions requirements and boost power output to support the growing needs of the city. This paper will describe the engineering design challenges to modify the existing LM2500 gas turbine package to accept the longer and more powerful LM2500+DLE gas turbine, and the results of the evaluations of the additional mass flow impact on steam production and combined cycle plant performance. This paper will also detail the upgrade execution outages and commissioning experience of the LM2500+DLE gas turbines at the COMH plant. The actual operational performance results will be outlined to show the approximately 30% increase in gas turbine power output, 5% decrease in gas turbine heat rate, and the annual reduction in NOx emissions of up to 900 tons per year.