Patent ID: 8215114

Claim:
A vapour power generating system for generating power by using heat from a source of heat, comprising a closed circuit with a working fluid, the system including: a heater for heating the working fluid under pressure with heat from the source of heat; a separator for separating a vapour phase of the working fluid heated by the heater from a liquid phase thereof; an expander for expanding the vapour phase of the working fluid to generate power; a condenser for condensing the working fluid discharged from the expander; a feed pump for returning the working fluid condensed in the condenser from the condenser to the heater; and a return path for returning the liquid phase of the working fluid from the separator to the heater; wherein the liquid phase of the working fluid contains a lubricant for at least one bearing for at least one rotary element of the expander, which lubricant is different from, and soluble or miscible in, the liquid phase of the working fluid, and a bearing supply path is arranged to deliver the liquid phase of the working fluid containing the lubricant and pressurised by the feed pump to the at least one bearing for the at least one rotary element of the expander.