13results about "Stirling type engines" patented technology

The invention relates to a thermoacoustic machine (1) comprising a control device (14) configured to modulate the acoustic power generated by one or more acoustic sources (6-9) so that the temperature of an external source (2) connected to one or more thermoacoustic cells (10-13) of the machine (1) reaches or remains substantially the same as a setpoint temperature. Figure for the abstract: Fig. 1

Geothermal engine with one element for absorbing heat from an upper heat source and one element for discharging heat to a lower heat source, the geothermal engine being suitable to be placed within a borehole (17) and having a cooling medium circuit, a cylindrical housing (9) with a cylinder head (10), a working piston (1), a displacer (2) with a regenerator (3), a crankshaft, and connecting rods for the piston and displacer, a rock mass - cylinder head heat exchanger as well as a generator-starting device. The working piston discharges heat to lower heat source, while the rock mass - cylinder head heat exchanger (11) absorbs heat from the upper heat source. The cooling medium circuit comprises a pump, a casing pipe (13), and a central pipe (15). Inside the casing pipe (13), there is a flow space (14) for the heated cooling medium, while inside the central pipe (15), there is a flow space (16) for the cooled cooling medium, which constitutes the lower heat source and circulates over the upper surface of the working piston (1). The crankshaft (4) is enclosed within the engine's working chamber, where a working gas is present between the piston (1) and the displacer (2). The pump includes at least one suction valve (7) and at least one discharge valve (8). Method for obtaining energy from the rock mass using such a geothermal engine mounted in a borehole in which the movement of a working piston (1) is initiated and the flow and change in volume of a working gas located inside of the engine is forced providing mechanical energy needed to start the engine with the use of an external generator-starting device (19), powered from the surface and working in starting mode, then the generator-starting device (19) is switched to generating mode, then the compressed working gas is heated with heat obtained from the borehole and transfers said heat to cool cooling medium, converting the mechanical energy of the working piston movement with use of the generator-starting device (19) that is set to generating mode in the electrical energy, that is extracted with wires (20) on the surface and pumping heated cooling medium with use of at least one discharge valve (8) through the cooling medium circuit to the surface.

A heat pump system includes a regenerative thermal machine (1*, 1**, 1***) in fluid communication with one or more heat reservoirs (21; 31), wherein the regenerative thermal machine (1*, 1**, 1***) comprises working fluid compression (12) and expansion (11) spaces; and an electrical machine (130) that is electrically connectable via interconnector (3) to an electricity distribution grid (2); characterised in that the regenerative thermal machine (1*, 1**, 1***) further comprises a phase change means (160) operable to change the phase relationship between the said working fluid compression (12) and expansion spaces (11) of the regenerative thermal machine (1*, 1**, 1***).

The present invention relates to a heat engine comprising at least one Stirling engine for converting thermal energy into mechanical energy or vice versa, and at least one power output. The Stirling engine has at least one displacer cylinder with a displacer piston and at least one working cylinder with a working piston. The displacer piston is connected to the power output via a displacer-piston-side transmission line, and the working piston is connected to the power output via a working-piston-side transmission line.

The invention relates to a thermoelectric or thermomechanical transducer comprising at least two volumes (381-384, 386, 481-483) whose size can be changed and which are limited by volume limiting elements (201, 221-224, 321, 401, 414-416) that, for example, include openings (271-278) for the inflow and outflow of liquid quantities, which are interconnected in a gas-permeable manner, which contain a working medium that is at least partially gaseous, and which can each be changed in size by volume changing elements (235-238, 335, 435), wherein at least one of the volume changing elements (235-238, 335, 435) changes the size of at least one of the volumes (381-384, 386, 481-483) such that its size on average during the operating size of the device is less than the mean of its maximum size and its minimum size for more than half the time, for example, for more than 60% of the time.

In one aspect the invention provides a Stirling cycle machine including a chamber containing a working fluid and defining a terminal end displaced from a thermal transfer zone, and a displacer shuttle free to reciprocate within the chamber towards and away from the terminal end of the chamber. Also provided is a drive piston with an end linked to a mechanical or electrical drive configured to reciprocate the drive piston towards and away from the terminal end of the chamber, the displacer shuttle being at least partly located inside the drive piston with the drive piston being free to move axially around and relative to the displacer shuttle. At least one switch magnet is engaged with the drive piston whereby motion of a magnet mounted to the displacer shuttle through the switch magnet forces the displacer shuttle to move in the opposite direction of travel to the drive piston.

A thermoacoustic device (50) includes a process volume which is filled with a working fluid through which the acoustic wave propagates. The thermoacoustic device further includes an acoustic network comprising a tubular loop (6) configured with a passage (4) providing an opening in the loop and configured as acoustic circuit provided with a compliance volume (14), a thermo-acoustic core (8) and an inertance volume (16). Within the loop, the thermoacoustic core is at a first side (8a) thereof adjacent to the passage at a first path length through the loop, and at its second side (8b), opposite to the first side, the thermoacoustic core is at a second path length from the passage. The thermoacoustic device includes within the loop a spring-type partitioning element (20) that is configured to close off the cross- section of the tube and to be impermeable for the working fluid while allowing transmission of pressure waves in the working fluid through the spring-type partitioning element.

An alpha type Stirling engine (1) comprises an expansion cylinder (2) and a compression cylinder (3), a regenerator (4), a cooler (5), and a heater (6). Each one of the expansion cylinder (2) and the compression cylinder (3) has a movable piston (10, 11) connected to a respective linear electric generator / motor (8, 9), wherein the Stirling engine (1) further comprises a control unit (20) which is operatively connected to the linear electric generators / motors (8, 9) and which is configured to control the linear electric generators / motors (8, 9) individually so as to enable a different stroke length and / or motion profile of the piston (10) in the expansion cylinder (2) compared to the piston (11) in the compression cylinder (3).

A thermoacoustic device that includes a resonator, wherein the resonator includes a stack. During operation, a cold zone of the stack is configured to receive at least one fluid from a hot zone of the stack; wherein a temperature of the hot zone exceeds a temperature of the cold zone. The thermoacoustic device also includes a conveyor for conveying at least some of the at least one fluid from the cold zone of the stack to the hot zone of the stack.

A system for energy conversion including a closed cycle engine having a piston body defining a hot side and a cold side and having a piston assembly movable within the piston bod. An electric machine is operatively coupled with the piston assembly and is operable to generate electrical power when the piston assembly is moved within the piston chamber. A control system includes one or more sensors operable to detect a piston movement characteristic of the piston assembly movable within the piston body. A controller is communicatively coupled with the one or more sensors and a controllable device. The controller is configured to determine a control command based at least in part on data received from the one or more sensors. The control command is selected based at least in part to cause the electric machine operatively coupled with the piston assembly to generate a preselected electrical power output.

The present disclosure relates to a system for controlling the power output of a Stirling engine, the Stirling engine comprising a hot heat source and a cold heat sink. A control unit receives a first temperature signal representative of a measured temperature of the hot heat source and a second temperature signal representative of a measured temperature of the cold heat sink. A look-up table provides a representation of the power output as a function of the mean engine pressure, pme, and the operating frequency, f, of the Stirling engine. The values of the power output in the look-up table have been determined for predefined temperatures of the hot heat source and the cold heat sink. The control unit is configured to, based on the received temperature signals, recalculate the values of the power output and update the look-up table accordingly, and to control the power output by controlling the mean engine pressure, pme, and the operating frequency, f, based on the updated look-up table. The present disclosure also relates to a method of controlling the power output of a Stirling engine.

A maximum delivery adiabatic reciprocal hot-air engine having a free interior space with a wider interior diameter than ends and an isolator-displacer having an aerodynamic exterior shape that mates with an interior shape of the hot and cold caps. The chamber and isolator-displacer are configured to isolate the hot or cold cap while exposing the volume of working fluid to the corresponding cold or hot cap. The chamber having a common space that is alternately heated or cooled by the respective hot or cold cap, The chamber is joined to a piston cylinder at the chamber's maximum interior diameter, with a volume of working fluid within the chamber communicating thermally with a piston through an opening at the common space wall. The volume of working fluid is adiabatically compressed and expanded to its intermediate temperature, thereby maximizing work and efficiency with the least amount of heat and the smallest dimensions.

A system for energy conversion, the system including a closed cycle engine defining a hot side and a cold side, a heater loop positioned at least in part in a heat exchange relationship with the hot side of the closed cycle engine for imparting thermal energy thereto, and a hot side heat exchanger positioned along an intake line of the heater loop, wherein the heat loop has a heat recovery loop operable to recover heat from the hot side and return the recovered heat to the hot side, and wherein the heat recovery loop has a recirculation loop in fluid communication with the intake line for recirculating heating working fluid to the hot side heat exchanger.