Study on Optimization of Primary Air Inlet Opening Which Minimize The Pressure Drop Across the Air Preheater and Study of Effects of Variation in RPM of Rotor on APH Performance

Tri-Sector Rotary Air Preheater (APH) is a regenerative heat exchanger which utilizes waste heat energy contained in hot flue gases (product of combustion) by transferring this heat to incoming air which is to boiler. In this era of energy crises APH becomes an essential part of thermal power plants, installation of APH save up to 15 % of fuel cost in power plants. In this study 3D modeling of tri-sector APH done in ANSYS DESIGN MODULAR, we assume rotor made up of porous material and properties of material as constant. Air and flue gases flows in counter flow directions & there is separate passage for primary air, secondary air and flue gases. Earlier tri-sector APH is provided with 50° primary air opening in tri sector APH based on the quality of coal (4000 to 4500 Kcal/kg) exists that time, but coal available today is of lower quality (3000 to 3500 Kcal/hr) thus more quantity of coal to be fired. For this more amount of primary air to be supplied to mills. This increased primary air flow results in high pressure drop across the APH cases higher loading of primary air fans. In order to overcome this problem we studies effect of increase in Primary air inlet opening which minimizes the primary air pressure drop across APH. We have taken four different primary air opening angles i.e. 50°, 60°, 70° & 80° and study its effect on primary air pressure drop and APH performance. Also we studies effect of variation of rotor RPM for 70° primary opening on performance of APH.