Method of refurbishing an energy conversion facility and refurbished energy conversion facility

A refurbished facility for converting hydraulic energy into electrical energy, the refurbished facility comprising:

• a facility that is configured for being refurbished by way of a method—so as to result in the refurbished facility—that includes the steps of:
• providing:
• a first cover plate, which includes an inner surface;
• a second cover plate, which includes an inner surface;
• a first opening located at an inner head cover, which includes an outer surface;
• a second opening located at a hub, which includes an outer surface;
• a third opening located at a runner;
• connecting the first cover plate to the inner head cover;
• connecting the second cover plate to the hub, the first cover plate and the second cover plate surrounding an axis, wherein a part of the outer surface of the inner head cover, a part of the outer surface of the hub, the inner surface of the first cover plate, and the inner surface of the second cover plate confine an annular shaped space in order to allow a gas to flow from inside the inner head cover and through the first opening, the annular shaped space, and the second opening and to be discharged through the third opening into a water passage during operation of the refurbished facility, wherein the refurbished facility includes:
• the water passage;
• a turbine including the runner of an axial flow type, the runner being located within the water passage, being moveable around the axis, belonging to a rotatable part of the turbine, and including the hub and a plurality of blades connected to the hub;
• a drive shaft connected to the runner;
• and
• the inner head cover, which is located adjacent to the hub, surrounds the drive shaft, and belongs to a non-rotatable part of the turbine.