Reducing Auxiliary Power of Induced Draft Fans in Coal Fired Thermal Power Plants by Energy Audit

This paper describes the various opportunities for reducing the auxiliary power of induced draft fans in coal fired thermal power plants. The auxiliary power used by induced draft fans forms about 0.9 to 1.18 % of the total gross energy generation for 210 MW to 800 MW power plants. ID fans are the second largest (in rating) motor in a thermal power plant after Boiler Feed Pump (BFP). The detailed energy audit of auxiliary equipment in various thermal power stations, operational optimization and appropriate control system had shown ample scope for improving the energy efficiency of induced draft fans. The implementation of energy conservation measures reduce the average auxiliary power used by ID fans for 210 MW plant from average value of 1.18 % to 0.90 % of gross energy generation and the energy conservation schemes are economically attractive with a payback period of 1 to 5 years.