Patent ID: 7296408

Claim:
A heat engine which utilizes a liquid refrigerant and a hot thermal fluid to convert heat into mechanical work, the heat engine comprising: an expansion chamber having a piston disposed to execute strokes within a cylinder and a thermal fluid jacket containing the hot thermal fluid and disposed around the cylinder, wherein the expansion chamber heats the liquid refrigerant via heat transfer from the hot thermal fluid in the thermal fluid jacket and allows the refrigerant to expand, the expansion causing the piston to execute strokes and thereby generate work; a dynamic throttling valve for injecting liquid refrigerant into the cylinder adjacent to the piston, wherein the valve injects a minimal flow of liquid refrigerant at the beginning of the piston stroke and a maximal flow as the piston stroke continues; a pressure injector for injecting the liquid refrigerant into dynamic throttling valve under pressure; a compressor for compressing the expanded gas refrigerant from the expansion chamber; and a condenser for returning the compressed gas refrigerant from the compressor to a liquid state for use by the pressure injector.