Auxiliary member for assembly/disassembly of gas turbine casing, gas turbine having the same, assembly method of gas turbine casing, and disassembly method of gas turbine casing

An assembly method of a gas turbine casing which covers an outer circumference of a rotor which rotates about a rotational axis and in which a first casing member forming a portion in a circumferential direction and a second casing member forming the other portion in the circumferential direction are connected by a fastener, the method comprising:

• an auxiliary member preparation step of preparing an auxiliary member for assembly/disassembly in which a fixing portion which is fixed to one of the first and second casing members and a jack receiving portion which extends from the fixing portion and faces a radial outer surface of the other of the first and second casing members are formed;
• an auxiliary member fixation step of fixing the fixing portion of the auxiliary member for assembly/disassembly to a radial outer surface of one of the first and second casing members;
• a casing member disposition step of disposing the second casing member so as to face the first casing member;
• a jack disposition step of disposing a jack between the jack receiving portion of the auxiliary member for assembly/disassembly which is fixed to one of the first and second casing members;
• a jack operating step of widening the interval between both end portions of the jack, narrowing the interval in the radial direction between both end portions in the circumferential direction of the other of the first and second casing members, and making both end portions in the circumferential direction of the other of the first and second casing members face both end portions in the circumferential direction of one of the first and second casing members;
• and a casing connection step of connecting one of the first and second casing members and the other of the first and second casing members, in which both end portions face each other, by the fastener.

A disassembly method of a gas turbine casing which covers an outer circumference of a rotor which rotates about a rotational axis and in which a center side casing forming a portion in an axial direction in which the rotational axis extends and an end side casing forming an end side in the axial direction with respect to the center side casing are connected by a first fastener,

• in which the center side casing is configured so that a center side first casing member forming a portion in the circumferential direction and a center side second casing member forming the other portion in the circumferential direction are connected by a second fastener, and the end side casing is configured so that an end side first casing member which forms a portion in the circumferential direction, is adjacent in the axial direction to the center side first casing member, and is connected by the first fastener, and an end side second casing member which forms the other portion in the circumferential direction, is adjacent in the axial direction to the center side second casing member, and is connected by the first fastener are connected by a third fastener, the method comprising:
• an auxiliary member preparation step of preparing a plurality of auxiliary members for assembly/disassembly in which a fixing portion which is fixed to one of the end side first casing member and the end side second casing member and a jack receiving portion which extends from the fixing portion and faces a radial outer surface of the other of the end side first casing member and the end side second casing member are formed;
• an auxiliary member fixation step of fixing the fixing portion of a first auxiliary member for assembly/disassembly to a radial outer surface of the end side first casing member, and fixing the fixing portion of a second auxiliary member for assembly/disassembly to a radial outer surface of the end side second casing member so that the fixing portion faces the jack receiving portion of the first auxiliary member for assembly/disassembly with an interval in the axial direction therebetween;
• a fastener removing step of removing the second fastener which connects the center side first casing member and the center side second casing member, removing the third fastener which connects the end side first casing member and the end side second casing member, and removing the first fastener which connects the center side second casing member and the end side second casing member;
• a jack disposition step of disposing the jack between the jack receiving portion of the first auxiliary member for assembly/disassembly and the fixing portion of the second auxiliary member for assembly/disassembly, or between the fixing portion of the first auxiliary member for assembly/disassembly and the jack receiving portion of the second auxiliary member for assembly/disassembly;
• a jack operating step of widening the interval between both end portions of the jack, and separating the end side second casing member in the axial direction from the center side second casing member;
• and
• a center side casing removing step of separating the center side second casing member from the center side first casing member in the state where the end side second casing member is separated in the axial direction.