Hydro Turbine Thrust Bearing Oil Cooler | Core Heat Exchange Component Of Hydropower Station

The thrust bearing of the turbine unit bears the axial weight of the entire rotor. Friction in the bearing continuously generates heat (high-power units can generate hundreds of kW to 1MW). The turbine lubricating oil carries away this heat, which is then cooled by this cooler. Strict control is maintained for the thrust bearing temperature to be ≤70℃ and the oil temperature to be 40~50℃ to prevent lubricating oil deterioration, bearing burnout, and unplanned unit shutdowns.

Water circuit: Cooling water (river water/circulating demineralized water) flows inside the pipes.
Oil circuit: Immersed outside the pipes/external circulation using 46# turbine oil, oil-water isolated heat exchange.

Two main structural types (industry mainstream):

In-tank Internal Type (oil tank submerged type)

1) Drawer-type U-shaped coil (mainstream in China's Three Gorges/Baihetan projects)
U-shaped copper-nickel tube bundle, modular drawer design, pulled out from the side wall of the oil tank for maintenance. Each thrust bearing is equipped with one set of coolers, relying on the rotation of the mirror plate for self-priming oil circulation (mirror plate pump self-circulation). No external oil pump, simple structure, suitable for small to medium-sized/giant mixed-flow turbines.

2) Annular coil type: Arranged in a complete ring around the outer ring of the oil tank, mostly used for natural convection cooling in small axial flow units.

External Type (Remote External Circulation): The cooler is independently installed on the floor of the generator room. An external oil pump forces oil circulation (hot oil from the oil tank → cooler for cooling → return to the oil tank). Available in shell-and-tube or plate heat exchangers, commonly used in 600MW+ mega-hydropower units and pumped storage units. Advantages: High heat dissipation capacity, no need for oil draining during maintenance, and not limited by oil tank space.

Operating Parameter Reference:
Cooling Water Temperature: Inlet water ≤25℃, inlet and outlet water temperature rise 3~5℃
Oil Side: Inlet oil 50~55℃, outlet oil 40~45℃
Cooling Medium: Closed-loop softened water / Open-loop river water

Matching product in the same series: Guide Bearing Oil Cooler. This cooler is compatible with the upper and lower guide bearings of water turbines. Its structure and materials are the same as those of the thrust oil cooler, and it is often supplied as part of a project.