Patent ID: 6751959
Filing Date: 2004-06-22
Classification: F01K

Abstract:
A thermodynamic power cycle system for extracting a flow of heat from a heat source stream and generating mechanical power from the flow of heat by means of a working fluid flowing within a closed-loop cycle, said system comprising:means for transferring heat from the heat source stream to the working fluid such that the working fluid warms from a first temperature to a second temperature that is more than 30Â° F. greater than the critical temperature of the working fluid, wherein the working fluid has a critical temperature more than 40Â° F. lower than a temperature of the heat source stream and has a normal boiling point less than 32Â° F.; means for expanding the working fluid and converting work of expansion of the working fluid to mechanical power; said means for expanding and converting work of expansion also throttling the working fluid such that a pressure of the working fluid exceeds the critical pressure of the working fluid by an amount greater than 5% of the critical pressure of the working fluid as the working fluid emerges from the means for transferring heat; means for cooling to condense and subcool the working fluid after the means for expanding; and means for returning the working fluid to the means for transferring heat; and an additional means for throttling the working fluid after the means for transferring heat and before the means for expanding, wherein the means for transferring heat, the means for expanding, the means for cooling, and the means for returning the working fluid to the means for transferring heat are the only four means in which energy is removed from or transferred into the working fluid in the form of heat or work.