Two-shaft gas turbine

Abstract

A two-shaft gas turbine includes a high-pressure turbine having an annular gas-passage outlet, a low-pressure turbine having an annular gas-passage inlet, an annular intermediate duct that connects the gas-passage outlet to the gas-passage inlet, a bearing that supports a rotor of the high-pressure turbine and that is attached to a bearing case, and a plurality of struts that support the bearing case. The struts are arranged radially along the circumference of the bearing case so as to extend though the intermediate duct in a space between an outer peripheral surface of the bearing case and an inner peripheral surface of a casing wall that surrounds the intermediate duct. The intermediate duct has strut covers through which the struts extend and which function as first-stage stator blades for the low-pressure turbine.

1 . A two-shaft gas turbine comprising:
 a high-pressure turbine having an annular gas-passage outlet;   a low-pressure turbine having an annular gas-passage inlet;   an annular intermediate duct that connects the gas-passage outlet to the gas-passage inlet;   a bearing that supports a rotor of the high-pressure turbine and that is attached to a bearing case; and   a plurality of struts that support the bearing case, the struts being arranged radially along the circumference of the bearing case and extending though the intermediate duct in a space between an outer peripheral surface of the bearing case and an inner peripheral surface of a casing wall that surrounds the intermediate duct, wherein   the intermediate duct is divided into a plurality of segments along the circumference thereof, each of the segments integrated with a single strut cover and provided detachably from one another, the struts extend through an arbitrary number of the strut covers, and   the intermediate duct has strut covers through which the struts extend and which function as first-stage stator blades of the low-pressure turbine.   
     
     
         2 . (canceled) 
     
     
         3 . The two-shaft gas turbine according to,  claim 1  wherein the intermediate duct is divided into twenty segments and the struts are provided so as to extend through ten of the strut covers, the strut covers without the struts and the strut covers having the struts being arranged alternately. 
     
     
         4 . The two-shaft gas turbine according to  claim 1 , wherein each strut cover has a wing-shaped cross section in which the width of a front section of the strut cover gradually increases downstream in the direction of gas flow.