Abstract: A method for controlling the fuel-air ratio of a burner having a blower responsive to a blower drive signal for injecting air into the burner. The method is based at least on the concentration of a gas in an exhaust gas product of a combustion chamber of the burner and includes measuring the gas concentration in the exhaust gas product, deriving a gas concentration signal from the measured gas concentration, determining the fuel-air ratio from the gas concentration signal and the sign of the derivative of the gas concentration signal with respect to the blower drive signal, and controlling the fuel-air ratio by adjusting the air flow rate into the burner. The burner may be, for example, in a Stirling cycle engine.

Abstract: A method of combusting fuel and air in a burner of an external combustion engine having a heater head. The fuel and air are combined to form a fuel-air mixture which is characterized by a fuel-air ratio. An exhaust gas product is produced when the fuel-air mixture is combusted in the burner of the external combustion engine. A flame is formed by igniting the fuel-air mixture at a first fuel-air ratio produced by a first air flow rate and a fuel flow rate. The air flow rate is then increased to produce a second fuel-air ratio. The fuel flow rate is also controlled based upon a temperature of the heater head of the external combustion engine. The flame is maintained at the second fuel-air ratio by adjusting the air flow rate based on the fuel flow rate. The external combustion engine may be, for example, a Stirling cycle engine.

Abstract: An apparatus for providing cooling has a heat engine in which the cycle profile of at least one of the displacer and the piston is variable for to provide efficient cooling at various temperature differences.

Abstract: An apparatus and method are provided for adaptively controlling a closed-cycle thermal regenerative machine. The apparatus includes a housing having at least one chamber for containing a thermodynamic working gas, a linear motor associated with the housing, and a first moving member carried by the linear motor for axial reciprocation within the housing. A second moving member is carried for axial reciprocation within the housing and communicates with the first moving member via the contained thermodynamic working gas. Also included are a pair of permanent magnets, one magnet carried by each moving member; a pair of Hall-effect sensors, one sensor carried by the housing proximate each of the magnets and operative to detect axial displacement amplitude of the proximate reciprocating magnet and moving member. A power supply is coupled to the linear motor and is operative to deliver operating power to the linear motor.

Abstract: A traveling-wave device is provided with the conventional moving pistons eliminated. Acoustic energy circulates in a direction through a fluid within a torus. A side branch may be connected to the torus for transferring acoustic energy into or out of the torus. A regenerator is located in the torus with a first heat exchanger located on a first side of the regenerator downstream of the regenerator relative to the direction of the circulating acoustic energy; and a second heat exchanger located on an upstream side of the regenerator. The improvement is a mass flux suppressor located in the torus to minimize time-averaged mass flux of the fluid. In one embodiment, the device further includes a thermal buffer column in the torus to thermally isolate the heat exchanger that is at the operating temperature of the device.

Abstract: A double-acting, rotating piston reciprocating in a cylinder 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 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 and compression spaces, respectively. The piston reciprocates as it rotates. The cylinder and piston together comprise an integral valve that seqentially 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: The invention comprises both apparatus and an accompanying method for the controlling of the speed, stroke and power output of a Stirling engine. The invention positions a valving arrangement to control the working gas flow within a gas flow passage connecting the hot end and cold end of the displacer cylinder; the valving arrangement is controlled by a suitable engine speed, stroke or power detector.

Abstract: An external combustion engine is provided with an engine body containing a cylinder, a working fluid within the cylinder, and a displacer piston reciprocable between two ends of the cylinder. A heat exchanger matrix permeable to said working fluid is provided at one end of the cylinder. The movement of the displacer establishes a flow path through a limited portion of the matrix such that the working fluid exchanges heat with different portions of the matrix at different displacer positions as the fluid is displaced between the two ends of the cylinder.

Abstract: Novel hot gas engines and heat pumps are provided which operate on an improved cycle related to the Stirling cycle. These hot gas engines and heat pumps use at least two separate heat exchanger assemblies and a plurality of valves to control fluid flow through the heat exchanger assemblies.

Abstract: A Stirling cycle engine having a reciprocating power piston and a reciprocating displacer operating in cylinders having ports covered and uncovered by the motion of the piston and displacer. Ports of the power piston cylinder are connected to ports of the displacer cylinder through cooling means arranged to cool the working fluid.Various drive linkages are described which enable the motions of the power piston and the displacer to closely conform to the ideal Stirling cycle.

Abstract: A hot-gas engine the power output of which is regulatable comprises a cylinder defining variable-volume primary and secondary chambers separated by a piston moving in the cylinder, the movement of which piston is transmitted to an external system extracting the mechanical work produced by the engine. The engine has a heater communicating with the primary chamber, a regenerator communicating with the heater and a cooler containing a supply of working gas at the maximum gas pressure occurring during the work cycle. The engine is provided with valves controlled to pass the working gas to, from and between the primary and secondary chambers in sequential steps.

Abstract: A closed fluid working system for a Stirling engine is disclosed. The working system has a plurality of chambers subdivided by double-acting pistons operating therein; the subdivided chambers are respectively hot and cold and connected in series whereby a hot chamber is always in communication with a cold chamber of the next most adjacent cylinder. Parallel arranged gas flow paths are interposed in each communication between hot and cold chambers, and regenerator-cooler mechanisms are disposed in each of said parallel arranged paths. Control means are employed to permit flow through one or more of said parallel paths or flow of different levels through all of the paths, during different load conditions of the engine to permit the regenerator-cooling capacity to be tuned to the needs of the engine.

Abstract: In a cryogenic apparatus wherein the refrigerator has a reciprocable displacer which must be coordinated with fluid control means, such as a rotary valve, to control the inlet and exhausting of high and low pressure fluid, respectively, to produce cooling, an improvement is disclosed comprising including means for providing proper coordination between displacer movement and fluid control means regardless of the direction in which the motor drive shaft is rotated.

Abstract: A hot-gas reciprocating machine having a plurality of working spaces connected via ducts to a common control member for controlling working medium flows to the working spaces from a source of pressurized working medium. The control member comprises a stator and a rotor coupled to the crank shaft of the machine, with flow of the working medium being controlled by valves sequentially opened by rotation of said rotor.

Abstract: A closed working fluid system for a regenerative Stirling engine is disclosed. The system employs double-acting pistons arranged with each low temperature (compression) space connected to one hot (expansion) space of an adjacent piston. The low temperature spaces are all connected to a reservoir system employing two separate chambers, one at a high pressure and another at a relatively low pressure. Control means select the reservoir for communication with the working system depending on the torque demand of the engine; the control means also permits fluid flow to pass from any one low temperature space to the selected reservoir when the pressure condition in the low temperature space exceeds the associated reservoir pressure.

Abstract: A hot gas piston engine with an output control which is realized by changing the working medium quantity participating in the working process and with at least one working system, to the working volume of which is coordinated an auxiliary system, in which prevails a higher pressure than the minimum working pressure; the working system is intermittently connected with the auxiliary volume at most over a part of each working cycle, whereby the connection to the auxiliary volume is variable both as regards opening cross section as also opening duration.

Abstract: Commercial exploitation of the closed-cycle Stirling engine has been delayed because of inherent difficulties in controlling the engine output instantaneously. The disclosed invention presents a method and a device for intermittent power control of a Stirling engine by alternately connecting and disconnecting a separate dead space to the engine gas circuit. The control cycle includes a multiple of engine revolutions and is independent of the engine speed.