A monolithic combustor body may provide multi-stage combustion. A combustor body may include a combustion chamber body and a plurality of heating walls that include a heat sink. The combustion chamber body may be disposed annularly about a longitudinal axis and defining a combustion chamber. The plurality of heating walls may include heat sink. The plurality of heating walls may occupy a radially or concentrically outward position relative to the combustion chamber and may define a corresponding plurality of combustion-gas pathways fluidly communicating with at least a proximal portion of the combustion chamber. During operation, the combustor body may exhibit multi-stage combustion that includes a first combustion zone occupying a distal or medial position of the combustion chamber relative to the longitudinal axis, and a second combustion zone occupying a proximal position relative to the first combustion zone and a radially or concentrically outward position of the combustion chamber and/or a radially or concentrically inward position of the plurality of combustion-gas pathways.

A monolithic combustor body may provide multi-stage combustion. A combustor body may include a combustion chamber body and a plurality of heating walls that include a heat sink. The combustion chamber body may be disposed annularly about a longitudinal axis and defining a combustion chamber. The plurality of heating walls may include heat sink. The plurality of heating walls may occupy a radially or concentrically outward position relative to the combustion chamber and may define a corresponding plurality of combustion-gas pathways fluidly communicating with at least a proximal portion of the combustion chamber. During operation, the combustor body may exhibit multi-stage combustion that includes a first combustion zone occupying a distal or medial position of the combustion chamber relative to the longitudinal axis, and a second combustion zone occupying a proximal position relative to the first combustion zone and a radially or concentrically outward position of the combustion chamber and/or a radially or concentrically inward position of the plurality of combustion-gas pathways.

A closed cycle regenerative heat engine has a housing defining a chamber. A displacer is housed in the chamber. A power piston is housed in the chamber. The displacer is resiliently deformable from a rest condition in response to displace the working fluid in the chamber. The displacer may be a multi-start volute spring. The displacer may be provided with a heat storage reservoir to store heat received from a working fluid as the working fluid is displaced from a heating location in the chamber to a cooling location in the chamber and reject heat to the working fluid when the working fluid is displaced from the cooling location to the heating location. The resiliently deformable displacer may comprise two components with an air space defined between the two components.

A closed cycle regenerative heat engine has a housing defining a chamber. A displacer is housed in the chamber. A power piston is housed in the chamber. The displacer is resiliently deformable from a rest condition in response to displace the working fluid in the chamber. The displacer may be a multi-start volute spring. The displacer may be provided with a heat storage reservoir to store heat received from a working fluid as the working fluid is displaced from a heating location in the chamber to a cooling location in the chamber and reject heat to the working fluid when the working fluid is displaced from the cooling location to the heating location. The resiliently deformable displacer may comprise two components with an air space defined between the two components.

A rotary heat engine including a central crankshaft and a plurality of cylinder assemblies and a heat exchanger assembly. At least one of the plurality of cylinders, and preferably all of the plurality of cylinders includes a cylinder member, a piston member slidably positionable within the cylinder member, a connecting rod and a rolling diaphragm. The rolling diaphragm is positioned between the piston and the cylinder assembly to define a working volume which is in fluid communication with an opening that is in communication with the heat exchanger body.

A constant density heat exchanger is provided. The constant density heat exchanger includes a housing extending between a first end and a second end and defining a chamber having an inlet and an outlet. A first flow control device is positioned at the inlet of the chamber and movable between an open position in which a working fluid is permitted into the chamber and a closed position in which the working fluid is prevented from entering the chamber. A second flow control device is positioned at the outlet of the chamber and movable between an open position in which the working fluid is permitted to exit the chamber and a closed position in which the working fluid is prevented from exiting the chamber. A heat exchange fluid imparts thermal energy to the volume of working fluid held at constant density within the chamber by the first and second control devices.

A constant density heat exchanger is provided. The constant density heat exchanger includes a housing extending between a first end and a second end and defining a chamber having an inlet and an outlet. A first flow control device is positioned at the inlet of the chamber and movable between an open position in which a working fluid is permitted into the chamber and a closed position in which the working fluid is prevented from entering the chamber. A second flow control device is positioned at the outlet of the chamber and movable between an open position in which the working fluid is permitted to exit the chamber and a closed position in which the working fluid is prevented from exiting the chamber. A heat exchange fluid imparts thermal energy to the volume of working fluid held at constant density within the chamber by the first and second control devices.

The invention described herein provides new devices suitable for effectively converting relatively low temperature differences into useful work (e.g., for generating electrical power), related systems, and methods of using and developing such devices/systems. The devices are characterized in, inter alia, comprising an at least partially enclosed moveable component (e.g., a piston), a closed pressurized gas system comprising sizeable void spaces, and a closed temperature modifying liquid system having portions that obtain temperature characteristics from two sources, which are alternatingly dispensed as droplets into the pressurized gas, creating a pressure/temperature difference in the gas which causes the moveable component to move back and forth along a stroke distance that does not include the void spaces, the pressure of the gas and liquid being at substantially balanced when the device is ready for operation.

The invention described herein provides new devices suitable for effectively converting relatively low temperature differences into useful work (e.g., for generating electrical power), related systems, and methods of using and developing such devices/systems. The devices are characterized in, inter alia, comprising an at least partially enclosed moveable component (e.g., a piston), a closed pressurized gas system comprising sizeable void spaces, and a closed temperature modifying liquid system having portions that obtain temperature characteristics from two sources, which are alternatingly dispensed as droplets into the pressurized gas, creating a pressure/temperature difference in the gas which causes the moveable component to move back and forth along a stroke distance that does not include the void spaces, the pressure of the gas and liquid being at substantially balanced when the device is ready for operation.

A Stirling cycle heat engine 10 includes one moving part, rotor 24 that combines the traditional functions of piston, displacer, and flywheel. There is no reciprocating motion and no travel of the center of gravity. It can be built as a hermetically closed unit with few parts.