Strategies to Optimize Auxiliary Power Consumption in Coal Based Thermal Power Plant

In the present scenario total installed electricity generation capacity of India is 388849 MW, out of which 201995 MW generated by Coal & 6620 MW is generated by Lignite (1). Almost 50% of total energy generated is consumed by the industries alone .Auxiliary power in coal fired power station accounts for 7% to 12% of the gross generated power at the full plant load. This AP can be optimized by 4.5% to 9% for the same capacity range (2). The reason of excessive AP consumption is outdated technology, poor operation and maintenance, internal leakage, ingress of foreign material into equipment, ageing of equipment. Apart from this coal quality, amount of steam to be generated, load variation also affects the AP requirements. Higher AP consumption creates significant gap in power generated and power supplied to grid, due to which not only government norms are violated but it also accounts loss to the generating company. To compensate AP consumed within plant there is two methods. First is minimizing the electricity consumption and second is more power generation. The second method is not cost effective. This paper discusses in details the maintenance strategy and some design aspects to improve the AP consumption.