Study the Performances of Induced Fans and Design of New Induced Fan for the Efficiency Improvement of a Thermal Power Plant

The Induced Draft (ID) fans and Forced Draft (FD) fans provide control for draft and forced air zoning of fuel burned furnaces of steam generation plant of a thermal power plant. The ID fan exhausts flue gases from the furnace and induces combustion air into the furnace by having the furnace operated under negative pressure. Forced Draft (FD) fans are used for supplying the combustion air into the furnace of a boiler. A good design of fan and its control system increases plant reliability by improving furnace pressure control and airflow control, which is most critical control part of combustion control system. In the present paper, the performances of the typical ID fans in the steam generation unit of a naphtha and natural gas based captive power plant have been studied. From the online data of a running plant, it has been observed that the considerable part of the losses in the ID fan is due to the over design than the present requirement and also the older design is another cause of low efficiency. So from this performance calculation of ID fan a better design of a fan has been proposed to improve the plant efficiency and save the energy for global interest.