A monolithic heat exchanger body for inputting heat to a closed-cycle engine includes heating walls and heat sink, such as heat transfer regions. The heating walls are configured and arranged in an array of spirals or spiral arcs relative to a longitudinal axis of an inlet plenum. Adjacent portions of the heating walls respectively define corresponding heating fluid pathways fluidly communicating with the inlet plenum. At least a portion of the heat sink is disposed about at least a portion of the monolithic heat exchanger body. The heat sink includes working-fluid bodies including working-fluid pathways that have a heat transfer relationship with the heating fluid pathways. Respective ones of the heat transfer regions have a heat transfer relationship with a corresponding semiannular portion of the heating fluid pathways. Respective ones of the heat transfer regions include working-fluid pathways fluidly communicating between a heat input region and a heat extraction region.

A constant density heat exchanger and method of operating are 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 plate is positioned at the first end of the housing and rotatable about an axis of rotation such that the first plate selectively allows a working fluid to flow into the inlet of the chamber. A second plate is positioned at the second end of the housing and rotatable about the axis of rotation such that the second plate selectively allows the working fluid to flow out of the outlet of the chamber. The first plate and the second plate are rotatable about the axis of rotation so as to hold a volume of the working fluid at constant density as a heat source imparts thermal energy thereto.

A thermodynamic apparatus, such as a Stirling engine or a Vuilleumier heat pump, has a heat exchanger in which energy is exchanged between a working fluid and an exhaust gas stream. On top of the cylinder of the thermodynamic apparatus is a dome-shaped section. By incorporating the heat exchanger within the dome, the flow paths can be simplified, the number of separate components reduced, and overall weight reduced. Flow passages for the working fluid are embedded in the dome. Channels for the exhaust gases are formed in an outer surface. The passages and the channels are helically arranged, one clockwise and one counter clockwise. The dome can be cast with a core for the casting fabricated via three-dimensional printing. In some embodiments, the dome is made of fiber-reinforced material.

A method and apparatus that reduces the dead volume in a heat engine or heat pump, such as a duplex Stirling or Vuilleumier cycle device, by nesting the components of the displacer and regenerator such that nearly all working fluid is purged from the interstices of the regenerator elements and all other working fluid spaces that are not involved in doing useful work at each portion of the cycle. Particularly, a more scalable and efficient method and apparatus for providing solar air conditioning or refrigeration by means of a heated cylinder that alternately pressurizes and depressurizes a separate cooling cylinder by directly transferring thermally induced pressure changes to that cooling cylinder at optimized times in the cycle, under the control of a numerically controlled actuation system that can cycle at a much lower rate than mechanically coupled or harmonically phased systems.

Disclosed is an energy collector system applicable to internal combustion engines. It may include: a) a collector of thermal energy from the exhaust gases; b) a thermal tank covered by helical tubes to gain heat by the exhaust gases; c) a heat exchanger; and d) an outer element capable of converting thermal energy into mechanical energy, such as a closed Brayton cycle turbine, a Stirling engine, a Rankine turbine or an open loop air motor for converting mechanical energy (coupling the difference in rpm) into electrical energy with an electrical generator. The thermal energy collector may be composed of a heat exchanger that collects energy from the exhaust gases. The electrical energy generated may be used for driving a hybrid vehicle. The thermal tank is capable of storing energy as heat, as well.

A method and apparatus that reduces the dead volume in a heat engine or heat pump, such as a duplex Stirling or Vuilleumier cycle device, by nesting the components of the displacer and regenerator such that nearly all working fluid is purged from the interstices of the regenerator elements and all other working fluid spaces that are not involved in doing useful work at each portion of the cycle. Particularly, a more scalable and efficient method and apparatus for providing solar air conditioning or refrigeration by means of a heated cylinder that alternately pressurizes and depressurizes a separate cooling cylinder by directly transferring thermally induced pressure changes to that cooling cylinder at optimized times in the cycle, under the control of a numerically controlled actuation system that can cycle at a much lower rate than mechanically coupled or harmonically phased systems.

The present invention provides a heat medium circulation structure for a micro-combined heat and power (micro-CHP) generator in which a heat medium that primarily looses heat by undergoing heat exchange with water in a hot-water tank and thus has a low temperature further performs heat exchange with low-temperature direct water supplied through a direct water line, thereby further loosing heat, in a return line heat exchanger, and then returns to a stirling engine through a heat medium return line, thereby effectively cooling a low temperature portion of the stirling engine. Thus, the heat medium circulation structure enables high electricity production efficiency. Further provided is a hot water temperature control method for a micro-CHP generator in which the consumption of hot water is detected by a flow sensor. First and second predetermined temperatures are defined to operate a stirling engine in the case of temperature droppings of hot water respectively due to natural radiation and consumption of hot water.

A Stirling-cycle apparatus is provided comprising a hermetically sealable housing; a first rotary displacement unit in fluid communication with a second rotary fluid displacement unit, each operably mounted in a separate, fluidly sealed portion within said housing and adapted to provide a cyclic change of at least one thermodynamic state parameter of a working fluid during use. Furthermore, each one of said first and second rotary displacement unit comprises a compressor mechanism, having a first compressor working chamber that is adapted to receive a first portion of said working fluid, and at least a second compressor working chamber that is adapted to receive a second portion of said working fluid, said first compressor working chamber comprises a first outlet port and said second compressor working chamber comprises a second outlet port. Each one of said first and second rotary displacement unit further comprises an expander mechanism, having a first expander working chamber that is adapted to receive said first portion of said working fluid, and at least a second expander working chamber that is adapted to receive said second portion of said working fluid, said first expander working chamber comprises a first inlet port and said second expander working chamber comprises a second inlet port; a drive coupling assembly, adapted to operably and operatively couple said first expander mechanism to said first compressor mechanism. The drive coupling assembly further comprises a rotating valve mechanism, adapted to provide a predetermined sequence of a cyclic fluid exchange between said first compressor working chamber and said first expander working chamber, and between said second compressor working chamber and said second expander working chamber, at predetermined intervals of the angle of rotation of said first and second rotatory displacement unit. The Stirling-cycle apparatus further comprises an actuator, operably coupled to said first and second rotary displacement unit, and adapted to synchronously link the rotational movement of said first rotary displacement unit with said second rotary displacement unit, such that said first predetermined cyclic change of at least one thermodynamic state parameter of said working fluid is offset in relation to said second predetermined cyclic change of at least one thermodynamic state parameter of said working fluid by a predetermined phase angle, during use.

A rotating machine is disclosed and includes a stator defining a circumference, a plurality of first magnet arrays, a rotor, and a first piston. The first magnet arrays are comprised of a plurality of discrete magnets arranged around the circumference of the stator in a first magnetic pattern. The rotor is rotatable about an axis of rotation and defines a main body. The main body defines a first passageway. The first piston includes a plurality of first magnetic elements and is actuated within the first passageway of the rotor. The plurality of discrete magnets are arranged in the first magnetic pattern and are positioned to interact with the magnetic elements of the first piston to create a first magnetic force as the rotor rotates about the axis of rotation. The first magnetic force represents a first amount of force required to actuate the first piston.

The invention relates to a system for recovering thermal energy produced in pyrometallurgical process plants and converting said thermal energy into electrical energy. The system is characterised in that it comprises at least one heat transfer chamber (1) comprising a gas interface section (1A), for separating the subsystem from the corrosive power of, and incrustation generated by, the gases from the heat source or duct (5). The system also comprises a section (1B) for connecting to a Stirling engine (2), which is a thermal engine and which, by means of the cyclical compression and expansion of a gaseous working fluid, at different temperature levels, produces a net conversion of thermal energy into mechanical energy.