Effect of inlet conditions on the thermal insulation performance of marine gas turbine exhaust systems

A marine gas turbine insulation solution was designed to reduce exhaust system temperatures. The effects of cooling gas temperature (45?C, 55?C, 65?C), cooling air velocity (2-10 m/s), and a range of classic aerodynamic conditions ranging on the thermal insulation performance of the gas turbine exhaust system were investigated using numerical simulations. The results indicate that the use of aerogel insulation material effectively reduces the average temperature of the exterior volute casing to 71?C from 315?C under rated turbine conditions. The exterior volute casing temperature increases with higher cooling gas inlet temperatures but decreases with increasing cooling gas inlet velocities. Additionally, alterations in the aerodynamic conditions at the gas inlet will induce changes in the thermal insulation performance of the exhaust system, and excessive circumferential flow velocities can cause localized overheating in the exhaust volute casing.