Lubricating system for organic fluid power plant

Abstract

The condensate of a closed cycle power plant that uses an organic working fluid for lubricating the bearings of the turbine is cooled to a temperature below the condenser temperature by an auxiliary cooler before being supplied to the bearings. This subcooling of the lubricating liquid increases its viscosity to a value which causes the minimum thickness of the lubricating film in the bearings to be increased significantly. By increasing the minimum film thickness, the filtering demands on the lubricating condensate are reduced and the surface finish of the journals and bearings is less critical permitting the journals and bearing to be finished by standard precision grinding techniques. In a specific embodiment of the invention, a cannister housing the turbine/generator is provided with a sump for collecting liquid working fluid which is delivered to the bearings through a cooler. Where the prime mover is coupled to a generator through a gear box, all of which are contained in the sealed cannister, the viscosity of the condensate may be increased to such a level that the cooled working fluid is adequate to lubricate the gear box itself.

Dependencies are inferred from the claim text.