Solution of Combustor Noise in a Coal Gasification Cogeneration Application of 100-MW-Class Combustion Turbines

Abstract

The field conversion of two W501D5 combustion turbines to burn medium Btu fuel gas supplied by a Dow Chemical coal gasification process at Plaquemine, LA resulted in excessive 105-Hz airborne sound and a corresponding unacceptable nonsynchronous engine vibration when burning natural gas. A joint Westinghouse and Dow Chemical corrective action program is described including field tests. Test results indicated that the combustion noise phenomenon was related to the strength of the primary air scoop recirculation pattern and its compatibility with the fuel and steam momentum vectors. A design was selected that eliminated the nonsynchronous combustion noise generated vibration and reduced the 100-Hz third-octave noise from 115 db to 97 db, an intensity reduction of 64 to 1.