Generator seal assembly

A seal assembly for a generator comprising:

• a seal housing;
• an air side seal ring attached to the seal housing;
• and
• a coolant side seal ring attached to the seal housing axially spaced apart from the air side seal ring,
• wherein the coolant side seal ring comprises a plurality of coolant side seal ring segments,
• wherein each coolant side seal ring segment comprises a leading edge and a trailing edge with respect to a rotation of a rotor shaft of the generator,
• wherein each coolant side seal ring segment comprises:
• a seal fluid channel facing the rotor shaft and circumferentially extending over a predefined arc length, and
• a plurality of radial holes circumferentially distributed along the seal fluid channel from the leading edge to the trailing edge through which a seal fluid enters the seal fluid channel,
• wherein the seal fluid flows from the leading edge toward the trailing edge due to the rotation of the rotor shaft during an operation of the generator that reduces a pressure of the seal fluid in a region near the leading edge,
• wherein each coolant side seal ring segment further comprises a plurality of additional radial holes circumferentially distributed along the seal fluid channel in the region near the leading edge,
• wherein additional seal fluid enters the region near the leading edge through the additional radial holes to maintain the pressure of the seal fluid in the region near the leading edge above a pressure of the coolant,
• wherein the radial holes and the additional radial holes cooperate to define inlet holes, and
• wherein a distance between adjacent inlet holes is smaller in the region near the leading edge than a distance between adjacent inlet holes near the trailing edge.

A method for sealing a coolant in a frame of a generator comprising:

• circumferentially disposing a seal assembly at an axial end of the generator where a rotor shaft extends through the frame;
• and
• providing seal fluid to the seal assembly,
• wherein the seal assembly comprises a seal housing attached to the frame,
• wherein the seal assembly comprises a coolant side seal ring attached to the seal housing located axially inboard towards the coolant,
• wherein the coolant side seal ring comprises a plurality of coolant side seal ring segments,
• wherein each coolant side seal ring segment comprises a leading edge and a trailing edge with respect to a rotation of the rotor shaft,
• wherein each coolant side seal ring segment comprises:
• a seal fluid channel facing the rotor shaft and circumferentially extending over a predefined arc length, and
• a plurality of radial holes circumferentially distributed along the seal fluid channel from the leading edge to the trailing edge through which the seal fluid enters the seal fluid channel,
• wherein the seal fluid flows from the leading edge toward the trailing edge due to the rotation of the rotor shaft during an operation of the generator that reduces a pressure of the seal fluid in a region near the leading edge,
• wherein each coolant side seal ring segment further comprises a plurality of additional radial holes circumferentially distributed along the seal fluid channel in the region near the leading edge,
• wherein additional seal fluid enters the region near the leading edge through the additional radial holes to maintain the pressure of the seal fluid in the region near the leading edge above a pressure of the coolant,
• wherein the radial holes and the additional radial holes cooperate to define inlet holes, and
• wherein a distance between adjacent inlet holes is smaller in the region near the leading edge than a distance between adjacent inlet holes near the trailing edge.