A combined heat and power system comprises a shaft (4), a compressor (6) coupled to the shaft to compress intake gas to form compressed gas; a recuperator (10) to heat the compressed gas to form heated compressed gas; a combustor (12) to combust a fuel and the heated compressed gas to form combustion gas; a turbine (8) coupled to the shaft to expand the combustion gas to form exhaust gas; a load (24) coupled to the shaft; an exhaust outlet (18) to expel the exhaust gas to a heater for heating a fluid based on heat from the exhaust gas; a recuperator channel (28) providing a path for the exhaust gas to flow from the turbine to the exhaust outlet through the recuperator; and a bypass channel (22) providing a path for the exhaust gas to flow from the turbine to the exhaust outlet bypassing the recuperator.

A constant density heat exchanger and system for energy conversion 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 as the first flow control device and the second flow control device hold the volume of working fluid at constant density within the chamber.

A constant density heat exchanger and system for energy conversion 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 as the first flow control device and the second flow control device hold the volume of working fluid at constant density within the chamber.

A heat exchange module, a heat exchanger and a method for additively manufacturing the heat exchanger are provided. The heat exchanger includes a plurality of stacked heat exchange modules defining a flow passageway. Each heat exchange module defining a substantially curved closed geometry defining a central axis that extends along the axial direction. Each heat exchange module includes a first heat exchanging fluid inlet, a first heat exchanging fluid outlet and a plurality of heat exchange tubes fluidly coupling the first heat exchanging fluid inlet and the first heat exchanging fluid outlet. The plurality of heat exchange tubes defining a plurality of first heat exchanging fluid flow passages of equal length and a plurality of second heat exchanging fluid flow passages of equal hydraulic diameter.

An energy exchanger for exchanging energy between a hot flow and a cold flow may comprise a hot flow section and a cold flow section, each of the sections comprising the same quantity of channels having variable cross sections. The inlets of the hot flow channels may be juxtaposed to the outlets of the cold flow channels and the outlets of the hot flow channels may be juxtaposed to the inlets of the cold flow channels such that the hot and cold flows move in opposing directions. The energy exchanger may further comprise a liquid distribution system and a common interface between each hot flow channel and a corresponding cold flow channel with an exponentially varying surface area adapted for exchanging latent energy released through condensation in the hot flow section and absorbed through evaporation in the cold flow section.

An energy exchanger for exchanging energy between a hot flow and a cold flow may comprise a hot flow section and a cold flow section, each of the sections comprising the same quantity of channels having variable cross sections. The inlets of the hot flow channels may be juxtaposed to the outlets of the cold flow channels and the outlets of the hot flow channels may be juxtaposed to the inlets of the cold flow channels such that the hot and cold flows move in opposing directions. The energy exchanger may further comprise a liquid distribution system and a common interface between each hot flow channel and a corresponding cold flow channel with an exponentially varying surface area adapted for exchanging latent energy released through condensation in the hot flow section and absorbed through evaporation in the cold flow section.

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.

An energy conversion apparatus may include an engine assembly, such as a monolithic engine assembly. The engine assembly may include a first monolithic body segment and a plurality of second monolithic body segments directly coupled or directly couplable to the first monolithic body segment. The first monolithic body segment may define a combustion chamber and a recirculation pathway in fluid communication with the combustion chamber. The recirculation pathway may be configured to recirculate combustion gas through the combustion chamber. The plurality of second monolithic body segments may respectively define at least a portion of a piston chamber and a plurality of working-fluid pathways fluidly communicating with the piston chamber.

An energy conversion apparatus may include an engine assembly, such as a monolithic engine assembly. The engine assembly may include a first monolithic body segment and a plurality of second monolithic body segments directly coupled or directly couplable to the first monolithic body segment. The first monolithic body segment may define a combustion chamber and a recirculation pathway in fluid communication with the combustion chamber. The recirculation pathway may be configured to recirculate combustion gas through the combustion chamber. The plurality of second monolithic body segments may respectively define at least a portion of a piston chamber and a plurality of working-fluid pathways fluidly communicating with the piston chamber.