Steam turbine efficiency enhancement solutions for utility powerplant applications

A continuing concern to operators of steam turbines is increasing operating costs. These costs reflect not only the rising cost of fuel and materials but also the decreased efficiency of the aging turbine fleet. Over time, damage to turbine components and increased steam leakage are the major factors resulting in lost efficiency. Steam leakage alone can account for as much as 80 percent of the efficiency losses in turbines. Since the cost of fuel and materials is largely beyond the control of steam turbine operators, the primary mechanism for realizing savings is in the improvement of turbine efficiency. An innovative program has been developed to appraise, evaluate, and restore steam turbine efficiency without major modifications to components. New turbine seal technology coupled with improved repair methods can enhance efficiency gains. This paper describes improved methods of analysis, evaluation, and repair now available to improve unit performance.