Energy Audit and Exergy Analysis of Pumps and Fans in Thermal Power Plant

Abstract

One unit of electricity saved equals 3 units of electricity generated in recent power plant scenario. The Energy saved is equal to energy generated. The auxiliary power consumption in thermal power plant adds a major role in enhancing the efficiency of power plant. Thermal power plant also falls under the intensive consumer category like railways, metal industries, and port trust etc. Thus according to energy act it is important to analyze the consumption pattern of the power plant and implement ideas to boost efficiency. For a Thermal power plant of 210 MW capacity the Auxiliary Power Consumption (APC) is estimated to be 8-12% of total generation. Reducing APC not only reduces energy intensity but also increases revenues because of energy export. APC reduction steps includes various practices like proper operation and maintenance, maintaining proper draft, supplying more air, coating of pump and blades of fans, installing energy efficient drives, reduction of stages in condensate extraction pump, coating of equipment, etc. through planned Energy Audits. This Reduction in APC will eventually lead to monetary savings. The auxiliary power consumption is mostly in Boiler feed pump(2.45%), Condensate extraction pump (0.22%), Induced draft fans (1.11%), Forced draft fans (0.21%), Primary Air Fan (0.93%), Mills (0.66%) with reduction in auxiliary power consumption by 1% around 20,000 t/year CO2 emission is reduced with additional power improvement of 3MW. Thus major areas of concern are Pumps and Fans. The present work consists of energy audit and exergy analysis of nine numbers of boiler feed pump, six numbers of condensate extraction pump, nine numbers of cooling water pump, six number of induced draft fan,six number of forced draft fan, six number of primary air fans . Ultrasonic flow meter, pitot tube, anemometer, energy meters and pressure gauges are used to know flow of fluid, power consumption and net head. Performance of pump and fan is evaluated comparing efficiency and specific power consumption with design data. Based on this parameters lower performing pumps and fans are found and problem pertaining to lower performance are evaluated and their remedial actions are suggested. After implementing proper energy saving strategies in pumps and fans suggestions for energy saved and economic gain with simple pay back period is estimated with improvement in efficiency by 5%, 10% and 15%.