Cooling system for gas turbine combustor

摘要

A combustor of a gas turbine includes a combustion tube acting as a combustion chamber. In the combustion tube, a cylindrical heat insulating member is disposed and forms a wall of the combustion chamber. Numerous cooling air passages are formed in the heat insulating member and extending in the axial direction between cooling air inlet disposed at one end of the heat insulating member and cooling air outlet disposed at the other end of the heat insulating member. The heat insulating member is attached to the inner surface of the combustion tube at its cooling air inlet side end and a seal ring is disposed around the outer circumference of the heat insulating member at a portion between the cooling air inlet side end and the cooling air outlet side end. The seal ring is made of heat resistant material and prevents cooling air flowing through the annular space between the inner surface of the combustion tube and the outer surface of the heat insulating member. Since cooling air flows through the annular space around the outer surface of the heat insulating member, all of cooling air flows through the cooling passages in the heat insulating member and is used for cooling the heat insulating member. Therefore, the cooling capacity of the heat insulating member increases.