Abstract: Flow from a gas well is conditioned prior to a production pipeline. A flow line is coupled to a gas well to receive the gas and coupled to a production pipeline to direct the received gas away from the production site, the flow line residing at a production site and comprising an electric power generation system. The electric power generation system has a turbine generator. The inlet nozzle and the turbine wheel of the turbine generator is configured to reduce the pressure and temperature of the received gas to conditions associated with the production pipeline.

Abstract: The present disclosure relates to an engine (100) including a cylinder (102) that is filled with carbon dioxide. A first piston (104) is slidably configured inside the cylinder (102) and being configured to form a first cylinder (108) with a first end (130) of the cylinder (102). A second piston (106) is slidably configured inside the cylinder (102) and being configured to form a second cylinder (110) with a second end (132) of the cylinder (102). A heater (112) is circumferentially disposed around the first cylinder (108) and the first piston (104) is configured to expand a hot carbon dioxide received inside the first cylinder (108) from the heater (112). A cooler (116) is circumferentially disposed around the second cylinder (110) and second piston (104) is configured to compress a cold carbon dioxide received inside the second cylinder (110) from the cooler (116).

Abstract: 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.

Abstract: A Stirling engine is described which, in accordance with a first exemplary embodiment, has a transmission with a connecting rod and a double-acting step piston which is arranged in a cylinder. The step piston has a first section with a greater diameter and a second section with a smaller diameter, and is at least partially hollow. The connecting rod runs on the inside through the second section, and is connected in an articulated manner in the first section of the step piston.

Abstract: A first-stage regenerator material and a second-stage regenerator material are regenerator materials each having a laminated structure for use in a GM refrigerator. Each layer of the regenerator material is provided with a plurality of holes to allow gas to pass therethrough along a laminating direction. At least one layer includes a base material and a coating covering the base material. Volumetric specific heat of the coating is larger than volumetric specific heat of the base material in a temperature range from 20 K to 40 K.

Abstract: 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.

Abstract: A Stirling engine has a housing containing a displacer and a power piston arranged to reciprocate relatively to one another. A head is adjacent to the displacer to absorb heat, and is surrounded by a block of copper or aluminum. A substantial proportion of the block is clad with a layer of stainless steel or Inconel having a thickness of between 3 mm and 0.15 mm.

Abstract: The engine includes a first and a second cylinder chamber. The first chamber receives gas through a first inlet valve which gas will be compressed by a piston in the cylinder and will leave the first chamber through a first outlet valve. The second chamber receives compressed gas from the first chamber through a second inlet valve. The gas expands in the second chamber while performing a work on the piston before leaving the second chamber through a second outlet valve. The engine is controlled such that gas will flow from the first to the second chamber while the engine performs a working cycle and the engine is thus controlled such that a piston is used for compressing gas which performs a work on the same piston, which is connected by a rod to a cranking mechanism to transfer work from the rod by an essentially only rectilinear movement.

Abstract: A Stirling engine with internal regenerator and integral geometry for heat transfer and fluid flow has a displacer piston with a plurality of cavities that traverse through the displacer piston and are arranged in a specific cross sectional geometry. A heater head has heater fin protrusions that are also arranged in the specific cross sectional geometry, and a cooling bridge has cooler fin protrusions that are also arranged in the specific cross sectional geometry. The displacer piston alternates between the heater head and the cooling bridge, with the cavities of the piston alternately enveloping the heater protrusions and the cooling protrusions, providing more efficient heat transfer to and from the working fluid. Each cavity in the displacer also contains a regenerator core, further improving heat transfer efficiency.

Abstract: A thermal energy storage apparatus adapted to receive heat source input for the development and substantially continuous supply of thermal energy to a Stirling engine for the transfer of said thermal energy to electrical and/or mechanical energy, even during periods when heat source input is intermittent or unavailable for a period of time. The apparatus includes a series of elongate canisters containing silicon metalloid and made of refractory material. The canisters are interlaced with a thermal energy absorbing material in communication with a wicking material to which the Stirling engine is in communication.

Abstract: A solar energy thermal storage system can include a receiver in which a first storage medium is heated by insolation. First and second thermal storage reservoirs for a second storage medium can be provided. A first heat exchanger can be configured to transfer heat in the first storage medium to the second storage medium. A buffer tank can be located at a height above the receiver and can be fluidically connected to the first heat exchanger at its inlet and the receiver at its outlet. A second heat exchanger can be configured to transfer heat between the second storage medium and pressurized water and/or steam. The use of a buffer tank in conjunction with the first storage medium increases the overall efficiency of the system and results in a higher temperature for the thermal storage system, which can be used to generate superheated steam.

Abstract: 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.

Abstract: The present disclosure provides an engine assembly that is installed below the surface of the earth to harvest the thermal energy of the earth, using a working fluid in a closed loop system, and convert it into electricity, which can be commercialized at the surface. The subterranean engine comprises a hot region and a cold region, and a working fluid that moves between the two regions. The movement and efficiency of the working fluid operates the pistons that drive a generator coupled to the pistons, thereby generating electricity. The hot region of the engine is primarily powered by the geothermal energy. The engine can further incorporate renewable energy to improve the movement of the working fluid between the hot and cold regions. The system can further be used to store renewable energy below ground.

Abstract: A method for use in controlling a free piston Stirling machine having a cold end and a warm end and driven by a linear motor having an armature winding to which a drive voltage is applied. The method comprises (a) sensing internal mechanical collisions; (b) repeatedly sensing the temperature of the cold end, the temperature of the warm end and the drive voltage; (c) storing, as associated data, a value representing drive voltage, the temperature of the cold end and the temperature of the warm end at the time of sensed collisions; and (d) limiting the drive voltage to less than the drive voltage that was sensed at a collision and is stored in association with stored warm end and cold end temperatures that are proximate currently sensed warm end and cold end temperatures.

Abstract: A two piston, free piston, alpha Stirling cycle machine has a compression piston with a cylindrical bore that is coaxial with the cylinders in which the pistons reciprocate. An expansion piston sealingly extends into both an expansion cylinder and into the cylindrical bore in the compression piston. The expansion piston has the same diameter within both the expansion cylinder and the cylindrical bore. A spring, preferably a gas spring, drivingly connects the pistons. The reciprocation of the expansion piston varies only the volume of the expansion space and the reciprocation of the compression piston varies only the volume of the compression space. The spring that drivingly connects the pistons allows the two pistons to be properly phased without a mechanical linkage so that they can operate in a thermodynamically effective phase over a range of strokes.

Abstract: A heat engine includes a container in which a liquid piston made of a liquid operation fluid is sealed to flow therein, an exterior evaporator located outside of the container to generate vapor of the operation fluid, a suction portion arranged at one end side of the container to draw the vapor generated in the exterior evaporator into the container, an expansion portion in which the vapor drawn into the container is expanded to cause a displacement of the liquid piston, an output portion arranged at the other end side of the container to convert the displacement of the liquid piston to a mechanical energy, a liquid piston discharge portion for discharging a part of the liquid operation fluid as the liquid piston from the container, and a vapor discharge portion configured to discharge the vapor without being condensed in the container to outside of the container.

Abstract: A Stirling cycle engine comprised of at least two annular chambers, serving as hot and cold cylinders, which are joined together forming a Figure-8 chamber. A slidable, segmented piston disposed within the Figure-8 chamber, under the influence of thermally induced working fluid pressure changes within the engine, traverses the Figure-8 chamber providing a motive force to generate electric power or transfer mechanical energy external to the engine.

Abstract: A powering system includes an engine having a first side and an interface for providing heat to the first side of the engine. The interface includes a combustor having a combustion chamber positioned at least partially in an enclosure that receives a fuel and an oxidizer for combustion of the fuel and oxidizer into a combustion product. A conduit is connected to the combustion chamber for receiving the combustion product. A heat transfer fluid is positioned in the enclosure and engages an external surface of the combustion chamber and an external surface of the conduit within the enclosure. The heat transfer fluid is heated by the combustion product via the external surface of the combustion chamber and the external surface of the conduit such that the heat transfer fluid transfers heat to the first side of the engine. The heat transfer fluid may thereby decouples the engine from the combustor.

Abstract: A thermoacoustic engine includes first and second stacks disposed in parallel in a looped tube and a heat storage unit disposed in the looped tube. A circuit length between a center of the first stack and a center of the heat storage unit is equal to a circuit length between a center of the second stack and the center of the heat storage unit. A first acoustic circuit including the first stack and the heat storage unit has a circuit length which is equal to a circuit length of a second acoustic circuit including the second stack and the heat storage unit.

Abstract: A configuration of heat engine, a stirling engine, is presented that utilizes an even number of axially opposed, axially aligned cylinders and that can be made using almost unlimited variations in the number of cylinder pairings, size, length, operating temperatures and pressures, materials, heating and cooling sources, etc. The axially opposed configuration of the cylinder pairs maximizes engine efficiency by minimizing dead space, maximizing thermal isolation of the hot and cold sides, maximizing regenerator efficiency, maximizing the free flow of the working fluid and allowing the engine speed (rpm) and power output to be rapidly and precisely altered and controlled. When driven, the engine acts as a heat pump, with all of the aforementioned improvements and advantages over previous kinematic heat pumps and wherein the piston timing can be varied for precise temperature control and to provide a method of defrosting that requires no additional parts or heat source.

Abstract: A communication passage in a Stirling cycle transducer includes a cylindrical shaped thermal regenerator providing flow paths aligned with a regenerator cylindrical axis for providing periodic gas flow between first and second interfaces of the regenerator. A first heat exchanger conveys gas between a periphery of the heat exchanger and the first interface causing a change of direction of gas flow between radially and axially oriented flow within the regenerator and transfers heat between the gas and an external environment in a direction aligned with the regenerator cylindrical axis. A second heat exchanger conveys gas between a periphery of the heat exchanger and the second interface causing a change of direction of gas flow between radially and axially oriented flow within the regenerator and transfers heat between the external environment and the gas in a direction aligned with the regenerator cylindrical axis.

Abstract: A Stirling engine has a fluid passage that connects a low temperature-side actuating fluid space and a crankcase inner space, and a passage opening/closing valve that is provided in the fluid passage and that opens and closes the fluid passage. The passage opening/closing valve enables communication through the fluid passage upon startup of the Stirling engine, and shuts off communication through the fluid passage when the rotational speed of the crankshaft of the Stirling engine is equal to or greater than a pre-established start-enabling rotational speed.

Abstract: A power plant includes a closed loop, supercritical carbon dioxide system (CLS-CO2 system). The CLS-CO2 system includes a turbine-generator and a high temperature recuperator (HTR) that is arranged to receive expanded carbon dioxide from the turbine-generator. The HTR includes a plurality of heat exchangers that define respective heat exchange areas. At least two of the heat exchangers have different heat exchange areas.

Abstract: An externally heated engine is provided which has a piston and a displacer. The position of the piston can be adjusted by a yoke and disk assembly on one end of a link and spacers and gaskets in the cylinder. The relative position of the displacer with respect to the piston can be changed by changing the relative position of a pair of disks in the crankshaft assembly. The displacer is caused to reciprocate by a link which is moved by a displacer cam assembly. The displacer cam assembly includes a first cam and a second cam. The first cam and the second cam each have a groove path. The displacer link follows the groove path of the cams to cause the displacer to dwell at the two ends of its stroke and to move rapidly from one end to the other.

Abstract: 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.

Abstract: Systems and related methods are disclosed that generally involve adjusting the temperature of an air mass to improve the efficiency of an air hybrid engine. In one embodiment, an air management system is provided that includes a heat exchanger, a recuperator, and associated control valves that connect between the air hybrid engine, its exhaust system, and its air tank. The air management system improves the efficiency of the energy transfer to the air tank by compressed air during AC and FC modes and improves the efficiency of the energy transfer from the air tank by compressed air during AE and AEF modes. The improvement in efficiency from the system results in reduced engine and vehicle fuel consumption during driving cycles comprising accelerations, decelerations, and steady-state cruising.

Abstract: In a wood-pellet cogeneration unit comprising a pellet feed, a combustion chamber, an ash removal device and a stirling engine, in order to achieve an optimum efficiency, provision is made for an exhaust gas recuperator (11) to preheat combustion air (10) and for wood pellets to be gasified with a portion of this hot air (13), for this portion (13) of the hot combustion air (10) to be directed above a grate (4) into a gasification combustion chamber (3a) and for the fuel gas (18) thus produced to be sucked downwards through the grate (4) together with the ash by a side channel blower (7), for the fuel gas (18) under the grate (4) to be displaced with a flow impulse of the rest (14) of the hot combustion air (10) in such a way that, firstly, a low lambda value close to the CO limit is maintained and, depending on the temperature of the combustion chamber (3b), the combustion at a central nozzle (19) is stabilized, or, with increasing temperature of the combustion chamber (3b), the state of flameless combustion

Abstract: The apparatus includes a housing, a compression chamber disposed in the housing and having at least a first interface operable to vary a volume of the compression chamber, an expansion chamber disposed in the housing and having a second interface operable to vary a volume of at least the expansion chamber, and a thermal regenerator in fluid communication with each of the compression chamber and the expansion chamber. The thermal regenerator is operable to alternatively receive thermal energy from gas flowing in a first direction through the regenerator and to deliver the thermal energy to gas flowing in a direction opposite to the first direction through the regenerator. The compression chamber, the expansion chamber, and the regenerator together define a working volume for containing a pressurized working gas.

Abstract: The present invention provides a Stirling engine capable of effectively recovering heat from exhaust gas flowing through a flue, and connecting a heating portion 10 and a regeneration portion 5 with each other through an operation gas tube without providing a flow passage separating portion 110, and the heating portion 10 includes a heating portion head 10a and a heat-transfer tube group, the heating portion head 10a includes first through holes 30R and second through holes 30S, the first through holes 30R are formed closer to a center region of the heating portion head 10a as compared with the second through holes 30S, one ends of U-shaped tubes are mounted in the first through holes 30R and the other ends of them are mounted in the second through holes 30S, and parallel exhaust gas flow passages is formed between the U-shaped tubes.

Abstract: The present invention provides a Stirling engine capable of effectively recovering heat from exhaust gas flowing through a flue 42, and capable of connecting a heating portion 10 and a regeneration portion 5 with each other through an operation gas tube without providing a flow passage separating portion 110, and as the removing mode, number of revolutions of the Stirling engine is reduced, an operation of the Stirling engine is stopped, an amount of generated electricity at the Stirling engine is reduced, or the Stirling engine is reversely rotated.

Abstract: A regenerator, for use in a heat engine, configured to receive and store heat from a high-temperature gas flowing from a high-temperature space into the regenerator, and to provide the heat to a low-temperature fluid flowing from a low-temperature space into the regenerator. The regenerator includes a large number of layered metal meshes. Each metal mesh includes a large number of mutually parallel longitudinal strands and a large number of mutually parallel lateral strands perpendicular to the longitudinal strands. The metal meshes are layered such that each metal mesh is sequentially rotated in a same direction by a fixed angle with respect to an immediately previously layered metal mesh.

Abstract: An improvement is provided to a pressurized close-cycle machine that has a cold-end pressure vessel and is of the type having a piston undergoing reciprocating linear motion within a cylinder containing a working fluid heated by conduction through a heater head by heat from an external thermal source. The improvement includes a heat exchanger for cooling the working fluid, where the heat exchanger is disposed within the cold-end pressure vessel. The heater head may be directly coupled to the cold-end pressure vessel by welding or other methods. A coolant tube is used to convey coolant through the heat exchanger.

Abstract: The disclosure relates to heat engines that operate using low temperature differentials. A Stirling engine is modified to provide a new heat engine that has no contained working fluid. The new heat engine flexible cylinders and the pistons are moved vertically upward by cables and vertically downward by gravity.

Abstract: A device and method for producing a reformate fuel from a hydrocarbon gas source. The invention enables the conversion of a dilute hydrocarbon gas into a more easily consumable reformate fuel. Gases having low concentrations of hydrocarbons are concentrated using a concentrator into a gaseous or liquid concentrated VOC fuel. The concentrated VOC fuel is then converted into a reformate using a reformer. The reformate is more easily consumed by an energy conversion device such as a combustion engine, fuel cell, sterling engine or similar device that converts chemical energy into kinetic or electrical energy. The reformer enables complex hydrocarbon fuels that are not normally suitable for use in an energy conversion device to be converted into a reformate. The reformate may be directly supplied into the energy conversion device.

Abstract: A device and method for producing a reformate fuel from a hydrocarbon gas source. The invention enables the conversion of a dilute hydrocarbon gas into a more easily consumable reformate fuel. Gases having low concentrations of hydrocarbons are concentrated using a concentrator into a gaseous or liquid concentrated VOC fuel. The concentrated VOC fuel is then converted into a reformate using a reformer. The reformate is more easily consumed by an energy conversion device such as a combustion engine, fuel cell, sterling engine or similar device that converts chemical energy into kinetic or electrical energy. The reformer enables complex hydrocarbon fuels that are not normally suitable for use in an energy conversion device to be converted into a reformate. The reformate may be directly supplied into the energy conversion device.

Abstract: In various embodiments, a mechanical assembly and/or storage vessel is fluidly coupled to a circulation apparatus for receiving pressurized heat-transfer fluid from an outlet at a first elevated pressure, boosting a pressure of the heat-transfer fluid to a second pressure larger than the first pressure, and returning heat-transfer fluid to an inlet at a third pressure.

Abstract: The invention relates to a Stirling engine, including at least one cylinder in which two pistons are arranged which move counter to one another, with each piston being connected by means of a first connecting rod to an oscillating lever, and the oscillating lever is connected by means of a second connecting rod to the crankshaft, where the oscillating lever is connected in an articulated manner with its first end to the second connecting rod, it is pivotably mounted at its second end in the cylinder housing, and the first connecting rod is connected in an articulated manner between the first and second end.

Abstract: A thermodynamic cycle heat engine including a regenerator; a chamber in fluid communication with the regenerator; first and second rotors within the chamber, forming at least a pair of spaces within the chamber; and at least one actuator. The regenerator and the chamber form a portion of a closed space for a working fluid, the actuator is arranged to displace the rotors about an axis of rotation for the rotors, and at least a portion of the actuator is fixedly secured to the rotors. In some aspects, the actuator is arranged to receive energy from the rotors and operate as a generator, or a sensor is arranged to detect a condition associated with operation of the chamber and a controller is arranged to control the actuator responsive to the detected condition. In some aspects, the engine includes a heat exchanger in fluid communication between the regenerator and the chamber.

Abstract: A configuration of heat engine, a stirling engine, is presented that utilizes an even number of axially opposed, axially aligned cylinders and that can be made using almost unlimited variations in the number of cylinder pairings, size, length, operating temperatures and pressures, materials, heating and cooling sources, etc. The axially opposed configuration of the cylinder pairs maximizes engine efficiency by minimizing dead space, maximizing thermal isolation of the hot and cold sides, maximizing regenerator efficiency, maximizing the free flow of the working fluid and allowing the engine speed (rpm) and power output to be rapidly and precisely altered and controlled. When driven, the engine acts as a heat pump, with all of the aforementioned improvements and advantages over previous kinematic heat pumps and wherein the piston timing can be varied for precise temperature control and to provide a method of defrosting that requires no additional parts or heat source.

Abstract: An exhaust heat recovery apparatus includes: an exhaust heat recovery unit that produces motive power by recovering thermal energy from exhaust heat, wherein the produced motive power is combined with motive power produced by a heat engine and is output together therewith; an auxiliary that is driven by at least the exhaust heat recovery unit; and a power transmission-switching device that is provided between the heat engine and the exhaust heat recovery unit, the same power transmission-switching device being provided between the heat engine and the auxiliary, and that cuts off the connection between the heat engine and the exhaust heat recovery unit when there is no request to drive the heat engine. Thus, it becomes possible to effectively use the surplus motive power produced by the exhaust heat recovery unit when there is no request to drive the heat engine.

Abstract: A 4-cycle Stirling engine is for carrying out thermal power processes or heat power and cold and heat pumping processes with two double piston units which move with a phase offset to each other.

Abstract: An improved method and system for removing blockage from hydrocarbon transfer conduits (108). An apparatus and methods for cleaning a hydrocarbon transfer conduit is disclosed whereby a laser head (104) is placed in a hydrocarbon transfer conduit to be cleaned and supplied with a laser beam. The laser head applies the laser beam to an area in the hydrocarbon transfer conduit to be cleaned.

Abstract: A high-temperature side power piston (37) and a low-temperature side power piston (39), respectively demarcating a high-temperature space (45) and a low-temperature space (47), brings about volumetric changes of working gases in each of the high-temperature space (45) and the low-temperature space (47). At the same time, the power pistons are configured to transmit motive energy on receipt of pressure changes of working gases. A displacer (203) movably housed in a displacer cylinder (201) transfers the working gases between the high-temperature space (45) and the low-temperature space (47) without causing a pressure difference.

Abstract: A heat engine apparatus for use in association with a borehole and a method of operating a heat engine in association with a borehole. The apparatus includes a first heat exchanger assembly in fluid communication with a proximal segment of the borehole, a second heat exchanger assembly in fluid communication with a distal segment of the borehole, a circulation barrier for providing a seal between the apparatus and the borehole in order to isolate the proximal segment of the borehole and the distal segment of the borehole from each other, and a heat engine associated with the first heat exchanger assembly and the second heat exchanger assembly, wherein the heat engine is a gas phase closed cycle thermodynamic heat engine. The first heat exchanger assembly, the second heat exchanger assembly, the circulation barrier and the heat engine are all adapted to be inserted in the borehole.

Abstract: A regenerator having a plurality of involute foils disposed in an annular gap between an inner cylindrical tube and an outer cylindrical tube. The involute shape of the foils provides uniform spacing throughout the entire regenerator and substantial surface area for fluid contact.

Abstract: Disclosed are systems and methods for generating power. The system includes a sealed chamber, a displacer located inside the chamber, a magnetic mechanism to actuate the displacer, and a linear alternator. The chamber includes a first side, a first top surface, and a first bottom surface, the first side located adjacent to a heat source and the second side adjacent to a heat sink. The displacer includes a pivot surface, a rocker, or a slide, and may include a regenerator.

Abstract: A closed cycle heat engine is provided. The heat engine includes first and second expansion pistons that are fluidly coupled to a heater. The expansion pistons are also fluidly and operably coupled to a compression piston. A regenerator extracts heat from a working fluid flowing from the expansion cylinders to the compression cylinders to preheat the working fluid flowing to the heater. A cooler is arranged in between the regenerator and the compression cylinder to remove additional heat before the working fluid reaches the compression cylinder. The heat engine is arranged such that the working fluid travels unidirectionally within the engine. The heat engine may further include one or more actuated valves for controlling the flow of the working gas. In one embodiment, the pressure of the crankcase is controlled to be at or less than the heat engine minimum pressure.

Abstract: A 4-cycle Stirling engine is for carrying out thermal power processes or heat power and cold and heat pumping processes with two double piston units which move with a phase offset to each other.

Abstract: A Stirling engine has a fluid passage that connects a low temperature-side actuating fluid space and a crankcase inner space, and a passage opening/closing valve that is provided in the fluid passage and that opens and closes the fluid passage. The passage opening/closing valve enables communication through the fluid passage upon startup of the Stirling engine, and shuts off communication through the fluid passage when the rotational speed of the crankshaft of the Stirling engine is equal to or greater than a pre-established start-enabling rotational speed.

Abstract: The reciprocatable power piston of a free-piston Stirling machine is drivingly linked to a reciprocatable component body of an associated apparatus by at least one spring with no rigid connection linking the piston to the component body. The spring drive linkage allows the power piston and the reciprocatable component body of the associated apparatus to reciprocate at different amplitudes of oscillation. Therefore, the Stirling machine and the associated apparatus can be optimized at different amplitudes of piston and the component body oscillation thereby improving the optimization of two very different dynamic systems that are drivingly connected together.