Update: Process Optimizing Offers Performance Boost Without Major Capital Improvements

Issue 2 and Volume 107.

Industry deregulation and the continuing challenge to reduce emissions while improving performance are driving energy producers to seek ever-more innovative ways to generate power. Process optimization upgrades are among the more cost effective ways of improving power plant performance and competitiveness in a time of unprecedented market demands and cost constraints.

An example of one such process optimization upgrade is underway at Lower Colorado River Authority’s (LCRA) 1,600 MW lignite-fired Fayette Power Project near La Grange, Texas. SimSci-Esscor, an operating unit of Invensys plc, is providing its Connoisseur Performance Optimization Modeling System (POMS) for Unit 1 at Fayette. The model predictive control software solution is being installed as part of an overall nitrogen oxides (NOx) upgrade including the installation of low-NOx burners and separated over-fire-air.

“We are pleased with the performance of the Connoisseur program as a multi-variable control and optimization solution for our gas units,” says Larry Ripper, project coordinator for LCRA. “Based on prior experience, we expect to effectively reduce greenhouse gas emissions without increasing heat rate and without experiencing any negative impact on the ramp-up rate for the unit.”

Connoisseur is a comprehensive suite of process control software that simultaneously manages several processes, allowing operators to maximize plant efficiency. The Connoisseur program at the Fayette Power Project will work with an existing Foxboro I/A Series system to reduce emissions of nitrogen oxides and improve heat rate on the unit. The low NOx burner installation has been completed and the standard control logic is being implemented. The POMS system is intended to further improve both the full load and load following performance, without degrading emissions or heat rate objectives, through the application of multi-variable process control. Project completion is targeted for July. Invensys Performance Services will implement the solution. The goals include a 0.4 percent heat rate improvement; 10 percent NOx emissions reduction; unburned carbon maintained at 1 percent or less; and no degradation in ramp rates, other emissions, steam temperatures and pressures, and boiler slagging.

The SimSci-Esscor and Invensys Performance Services team have already completed successful implementations on gas-fired units at other LCRA plants. At one of those plants, Invensys helped LCRA to reduce NOx emissions by 12.3 percent, carbon dioxide (CO2) by 51,524 tons per year, and improve the heat rate by 0.65 percent – all without any degradation in the unit ramp rate.