ACHIEVING MAXIMUM PERFORMANCE FROM EXISTING ASSETS THROUGH THE APPLICATION OF A BALANCE OF PLANT OPTIMIZATION APPROACH

摘要

Competition in the electric power generation market demands that power plants operate efficiently and be able to generate the maximum amount of power for which they were designed consistently and safely. In addition, the significant increase in the price of natural gas has caused a renewed interest in building new and extending the life of existing coal-fired power plants. Existing plants are being retrofitted with emissions control equipment to meet stricter standards. This emissions control equipment consumes significant amounts of auxiliary power, which plant owners might find attractive to regain by increasing the maximum power output of the retrofitted units. Central station power plants have been designed with a significant amount of margin. Increasing a generating unit’s output by taking advantage of the inherent design margin can provide plant owners with an available source of new power with attractive returns. Improvements in equipment efficiency and control system performance allow electric generating units to take advantage of the existing design margins. In taking advantage of design margin in equipment, it is almost always the case there will be one or more design limits preventing full utilization. Eliminating the design limits allows increasing unit performance to the point where a different design limit is identified. Usually, the best performance results are identified in finding improvements in the major energy conversion equipment such as the boilers and steam turbines. Given new computer-based analytical methods, steam generator and steam turbine manufacturers can identify significant power increase potentials. An evaluation of the power plant auxiliary systems is necessary to assess the full impact on plant operation of major system uprates. Balance of plant equipment may limit the potential improvement of major power uprates. This paper discusses the need to thoroughly examine the balance-of-plant equipment and systems as part of any power uprate study. Examples will be given from recent studies to show how much additional generated power can be obtained if the balanceof- plant equipment and systems are considered as part of the boiler and turbine uprate.