Improving performance of primary air fansin thermal power plants through energy conservation techniques

Primary Air Fans are the essential auxiliary equipment to provide the primary air to lift the pulverized coal from mills to carry to burners and also to provide partial air for combustion. This paper describes various techno-economical energy conservation measures for reducing the carbon emission by improving the performance of Primary Air fans in coal fired thermal power plants based on the energy conservation/audit study conducted in 28 numbers of 210 MW power plants in India. The best operating points for pressure gain, flow, pressure drop across hydrodynamic resistive elements, equipment efficiency, power input and specific energy consumption are simulated by using MATLAB and presented in this paper with case study to validate the results. Optimizing the pressure at PA fan discharge, control of excess air, pressure drop across APH and mills and maintaining the optimum primary air pressure at mills thereby to maintain appropriate coal-air pressure at burners will help in reduction of auxiliary power of PA fans. The implementation of energy conservation measures in a typical 210 MW coal fired thermal power plant reduce the overall auxiliary power of PA fans by 0.26 % of gross energy generation and also reduce the carbon emission by 4,056 t/year.