Gas Turbine Handbook : Principles and Practices

216 Gas Turbine Handbook: Principles and Practices
Figure 13-9. Can-annular combustor failure due to liquid carry-over
in the fuel gas. 30,000 horsepower gas turbine-pump drive unit with
less than 24,000 operating hours.
shown in Figure 13-25 and 13-26 and tip condition as seen in Figure
13-27, can be evaluated. While a distorted temperature profile would
have been an early indication of the burnt turbine blade tips, damage
would have had to progress beyond the stage visible in the other photographs
before a gas path analysis would have indicated a problem.
Very early signs of damage due to erosion, corrosion, oxidation, or
FOD can be detected to the degree shown in Figure 13-28.
Additional information regarding engine health can be obtained
on gas turbines equipped with boroscope ports located between turbine
stages. Utilizing these ports is best accomplished with a rigidtype,
90-degree boroscope. This port may be provided in either the