OPTIMIZATION OF IN-HOUSE POWER CONSUMPTION BY REDUCING PRIMARY AIR PRESSURE IN SUPER CRITICAL COAL FIRED THERMAL POWER PLANT

In Coal fired thermal power plants, part of energy generated by the power plant is being consumed by its own auxiliary drives. The power consumption by these auxiliary drives for power generation is called as In-house power consumption. Inhouse consumption in coal fired super critical thermal power plants of capacity 500 Megawatt and above with Turbine Driven Boiler Feed pumps should be 5.25% and with Motor driven boiler feed pumps should be 6.00% as per Indian Government norms stated by Central Electricity Regulatory Commission (CERC). But currently it is in the range of 7% (800 MW units) to 10% (500 MW units) of gross generated power at full load conditions in most of the thermal power plants in India. The excessive auxiliaries power consumption is caused by various factors such as part loading of the plant, poor coal quality used as fuel, excessive steam flow, draft loss, internal leakages/ingress in equipment, over loading of drives, distribution network losses, reduced power quality, ageing etc., Here we optimize the loading of one such major auxiliary equipment - primary air fan which is the second major contributor in auxiliary power consumption in a thermal power plant after the cooling water system, by reducing its outlet pressure without compromising on unit performance and boiler efficiency.