Abstract:
Disclosed herein is an apparatus for extracting thermal energy from thermal expansion of a working medium in the apparatus. The apparatus includes a thermal expander, a compressor for compressing the working medium after the expansion, and a force modulation unit connecting the thermal expander to the compressor. The force modulation unit consists of two conversion gears that are connected by a lever system. The lever system can be dynamically controlled so that the non-constant force from thermal expansion is modulated into a substantially constant output force of the apparatus.
Abstract:
A linear, multi-cylinder Stirling cycle machine comprises a plurality of Stirling cycle units arranged in an open series or closed loop. Each of the units comprises a compression space in fluid communication with an expansion space via a regenerative heat exchange assembly. The compression space and expansion space are in fluid communication with, respectively, a compression piston and an expansion piston, and the separate Stirling cycle units are mechanically coupled together by linear power transmitters, which connect the expansion piston of one unit to the compression unit of the other. The linear power transmitters can be linear transducers such as linear motors or generators. In the open series arrangement the series of Stirling cycle units can have an initiating compressor at one end and a terminating expander at the other end. hi the closed loop arrangement, one of the Stirling cycle units can include an exergy throttle to restrict gas flow rates to control the speed of the machine. The machine may be used in a combined heat and power apparatus with some Stirling cycle units acting as engine/generators and with waste heat being used for heating. Some Stirling cycle units can be used for cooling or heat pumping.
Abstract:
An auxiliary power system (100) for providing electrical power and heat to an indoor area includes an external combustion engine (101), such as a Stirling cycle engine (101), for generating mechanical energy and thermal energy. The external combustion engine burns a fuel with substantially complete combustion such that exhaust emissions from the external combustion engine are below a predetermined exhaust level. A generator (102) is coupled to the external combustion engine (101) and converts the mechanical energy produced by the external combustion engine (101) to electrical power. A first power output is used to provide the electrical power produced by the generator (102). The external combustion engine (101) and generator (102) are disposed within a housing such that the external combustion engine (101), generator (102) and housing combination is a portable size. The thermal energy generated by the external combustion engine (101) may be used to heat the atmosphere surrounding the housing.
Abstract:
A double-acting, rotating piston (4) reciprocating in a cylinder (2) with the motion of the piston providing the valving action of the Sibling Cycle through the medium of passages between the piston and cylinder wall. The rotating piston contains regenerators (8) ported to the walls of the piston. The piston fits closely in the cylinder at each end of the cylinder except in areas where the wall of the cylinder is relieved to provide passages between the cylinder wall and the piston leading to the expansion (60) and compression spaces (62), respectively. The piston reciprocates as it rotates. The cylinder and piston together comprise an integral valve that sequentially opens and closes the ports at the ends of the regenerators alternately allowing them to communicate with the expansion space and compression space and blocking that communication.
Abstract:
A Stirling engine comprising: an engine housing (52) which includes compression and expansion cylinders (22, 24) and a crankcase (50); a compression piston (12) and an expansion piston (14) positioned in the respective cylinders (22, 24) in the housing (52) and coupled to a crankshaft (20) via bearing means (44); the crankshaft (20) being positioned in the crankcase area which is defined by the pistons (12, 14) and the housing (52); CHARACTERISED IN THAT the pistons (12, 14) include pad means (40, 42) between the pistons (12, 14) and their respective cylinders (22, 24) to minimize the friction therebetween during reciprocal movement thereof, the crankcase (50) is pressurized to inhibit the passing of working gas past the pistons (12, 14); and means (48) are provided for cooling the crankshaft (20) and the bearing means (44) thereby eliminating the need for oil in the crankcase (50).
Abstract:
A Stirling engine (1) in which a working space (5) is communicated with a working gas tank (17) through a minimum cycle pressure line (13) having an accelerating valve (11) and a one-way valve (12) and a maximum cycle pressure line (16) having a decelerating valve (14) and a one-way valve (15) is provided with a starting apparatus (18) including a bypass valve (25) provided between the two pressure lines (13, 16). When the engine (1) is to be started, the bypass valve (25) is opened and a starting motor (18) is set into operation. The bypass valve (25) is closed immediately after the Stirling engine (1) starts, thus enabling the engine (1) to quickly begin operating in a self-supporting manner.
Abstract:
A two piston Stirling engine which includes a heat exchanger arrangement placing the cooler (26) and regenerator (28) directly adjacent the compression space (22) for minimal cold duct volume; a sealing arrangement (54) and (56) which eliminates the need for piston seals, crossheads and piston rods; and a simplified power control system (60).
Abstract:
A thermodynamic oscillator having a displacer (5) and a piston (3) (further displacer) movable due to pressure fluctuations at the resonance frequency of the oscillator. The displacer (5) and the piston (3) are located in a working space (11, 15) which is filled with working medium and can be connected through a release valve (51, 125, 167) and a supply valve (53, 129, 169), respectively, to a single reservoir (55) filled with working medium with an increase and a decrease, respectively, of the ambient temperature with respect to a nominal temperature. The valves (51, 53, 125, 129, 167, 169) have an opening pressure which is a function of the ambient temperature. The average pressure and the resonance frequency of the oscillator can thus be stabilized at a variable ambient temperature. The oscillator can be operated as a cold-gas engine, a hot-gas engine (motor), a heat pump or a current generator.
Abstract:
A free-piston regenerative hydraulic engine includes a displacer piston (22) driven pneumatically by a high-pressure or low-pressure gas. Actuation of the displacer piston circulates working fluid through a heater (12), a regenerator (10) and a cooler (14). An inertial mass such as a piston (32) or a hydraulic fluid column effectively stores and supplies energy during portions of the cycle. Power is transmitted from the working fluid to a hydraulic fluid across a diaphragm (50) or lightweight piston to achieve a hydraulic power output. The displacer piston may be driven pneumatically, hydraulically or electromagnetically. The displacer piston and the inertial mass may be positioned on the same side of the diaphragm member or may be separated by the diaphragm member.