Deformation adjustment method for lower half inner casing

A deformation adjustment method for a lower half inner casing in a rotary machine that includes a rotor rotatable around an axis extending in a horizontal direction, an inner casing covering an outer periphery of the rotor, and an outer casing covering an outer periphery of the inner casing and in which the inner casing includes the lower half inner casing that has a semi-circular arc shape around the axis and that covers a portion of the rotor that is closer to a lower side than the axis is and an upper half inner casing that has a semi-circular arc shape around the axis and that covers a portion of the rotor that is closer to an upper side than the axis is, the outer casing includes a lower half outer casing that has a semi-circular arc shape around the axis and that covers an outer peripheral side of the lower half inner casing and an upper half outer casing that has a semi-circular arc shape around the axis and that covers an outer peripheral side of the upper half inner casing, the lower half inner casing includes a lower half inner casing body that has a semi-circular arc shape around the axis and that covers a portion of the rotor that is closer to the lower side than the axis is and an inner casing accessory part that is provided at the lower half inner casing body, the lower half inner casing body includes lower contact surfaces that extend in horizontal directions at both ends in a circumferential direction with respect to the axis and that are able to come into contact with the upper half inner casing, and the inner casing accessory part includes a protrusion portion that protrudes to be closer to a radial outer side with respect to the axis than the lower half inner casing body is and that protrudes to be closer to the upper side than the lower contact surfaces are, the method comprising:

• a preparation step of preparing a deformation adjustment device including an inner casing-side member that is attachable to the protrusion portion to be immovable in a radial direction with respect to the axis relative to the protrusion portion;
• a device alignment step of attaching the inner casing-side member to the protrusion portion and disposing the deformation adjustment device including the inner casing-side member around the protrusion portion;
• and
• a deformation adjustment step of pressing the inner casing-side member attached to the protrusion portion toward a radial inner side with respect to the axis or pulling the inner casing-side member toward the radial outer side.