Experimental investigations into the effusion plate wall temperature of impingement/effusion cooling systems for gas turbine combustors

Cooling technologies are playing critical roles in the development of advanced gas turbine combustors. The present experimental investigation has studied the effects of geometric factors such as gap distance, impingement hole diameter, and effusion hole arrangement on the wall temperature of a novel impingement-effusion cooling system. The wall temperature of the effusion plate was directly measured by high-precision thermocouples. The wall temperature distribution of the cooling unit was obtained by biharmonic spline interpolation based on the measured temperature data. The cooling performance of cooling systems with different structures under different working conditions was compared. The experimental results indicate that the increase of gap distance weakens the strength of impinging jet, and the overall cooling performance decreases, accordingly. The smaller the diameter of the impingement hole is, the weaker the cooling film is, leading to a poor overall cooling performance at the same cooling airflow. However, better overall cooling performance can be obtained at the same blowing ratio at the cost of much more cooling airflow. Dense and uniform effusion hole arrangement has a very favorable impact on improving the cooling film quality and cooling performance.