A process and system of extracting useful work or electricity from a thermal source, wherein heat energy from the thermal source is used in the form of a heated collection fluid; a first side of a heat exchanger is filled with a liquid or supercritical working fluid; fluid flow out of the first side of the heat exchanger is closed such that a fixed volume of the working fluid is maintained in the first side; the heated collection fluid flowed through a second side of the heat exchanger that is adjacent to the first side to affect a transfer of heat from the heated collection fluid to the fixed volume of the working fluid to raise its temperature and pressure; the pressurized working fluid is released from the first side of the heat exchanger upon the working fluid reaching a threshold state; a flow of the pressurized working fluid is directed to an expander capable of converting the kinetic energy of the pressurized working fluid into useful work or electricity; and the foregoing steps are repeated. A plurality of such operably coupled heat exchangers may be used in a manner such that the timing of the pressurized working fluid from each heat exchanger to the expander is offset.

An improved heat engine employing a dual-component working fluid and configured to generate internal heat from one component of the working fluid that heats the other component through the physical contact between them such that together with the addition of external heat, the engine advantageously yields enhanced work extraction efficiency through separate, parallel expansion of each of the working fluids.

A process and system of extracting useful work or electricity from a thermal source, wherein heat energy from the thermal source is used in the form of a heated collection fluid; a first side of a heat exchanger is filled with a liquid or supercritical working fluid; fluid flow out of the first side of the heat exchanger is closed such that a fixed volume of the working fluid is maintained in the first side; the heated collection fluid flowed through a second side of the heat exchanger that is adjacent to the first side to affect a transfer of heat from the heated collection fluid to the fixed volume of the working fluid to raise its temperature and pressure; the pressurized working fluid is released from the first side of the heat exchanger upon the working fluid reaching a threshold state; a flow of the pressurized working fluid is directed to an expander capable of converting the kinetic energy of the pressurized working fluid into useful work or electricity; and the foregoing steps are repeated. A plurality of such operably coupled heat exchangers may be used in a manner such that the timing of the pressurized working fluid from each heat exchanger to the expander is offset.

A dual-cycle heat engine employing a first cycling working fluid and a second cycling working fluid whose cycles overlap when fused into a combined working stream so as to preserve compression heat generated during compression of the first working fluid thereby yielding enhanced work extraction when complying with additional thermodynamic requirements.