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.

A control system algorithm is provided for the computer control of a solid-state switching device in a Stirling-electric hybrid vehicle. The algorithm satisfies the demands for electrical energy management, regulation, allocation and distribution to the electrical system of the vehicle during the operation thereof. The control system controls the management, regulation, allocation and distribution of electrical current throughout the vehicle's electrical system in response the commands of the vehicle operator. This includes the operation of wheel motors, electrical storage systems, the drivetrain and a plurality of other components, accessories and subsystems.

A control system algorithm is provided for the computer control of a solid-state switching device in a Stirling-electric hybrid vehicle. The algorithm satisfies the demands for electrical energy management, regulation, allocation and distribution to the electrical system of the vehicle during the operation thereof. The control system controls the management, regulation, allocation and distribution of electrical current throughout the vehicle's electrical system in response the commands of the vehicle operator. This includes the operation of wheel motors, electrical storage systems, the drivetrain and a plurality of other components, accessories and subsystems.

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.

In a gamma free-piston Stirling cooler driven by linear electric motors, a motor operating frequency for consuming minimum electric power is detected and a different motor operating frequency that delivers maximum thermal cooling power is detected. The frequencies are detected by varying the operating frequency in small steps while sensing (1) the motor power input to maintain a steady temperature or (2) the thermal cooling power of the Stirling cooler. A mode detection routine detects whether the appropriate freezer operation is the electric power minimization mode or the thermal cooling power maximization mode based upon the current thermal conditions in the freezer. When the freezer is sufficiently cold, the pistons of the Stirling cooler are driven at the minimum electric power consumption frequency. When the temperature is, or is likely to become, too warm, the pistons of the Stirling cooler are driven at the maximum thermal cooling power frequency.

A Stirling engine feedback controller is provided that includes a Stirling engine having at least one piston, where the Stirling engine includes an Alpha-Stirling engine, and a Gamma-Stirling engine. The feedback controller includes a power sensor, a computer, and an electronic feedback loop. Here, the power sensor is configured to sense the power of the Stirling engine then output a power signal. In one aspect, the computer can be a central processing unit (CPU), or a field programmable gate array (FPGA), where the computer operates a control algorithm. Further, the electronic feedback loop receives the output power signal and an output signal from the computer, where an output signal from the electronic feedback loop is configured to a control a position of the piston(s).

A Stirling engine feedback controller is provided that includes a Stirling engine having at least one piston, where the Stirling engine includes an Alpha-Stirling engine, and a Gamma-Stirling engine. The feedback controller includes a power sensor, a computer, and an electronic feedback loop. Here, the power sensor is configured to sense the power of the Stirling engine then output a power signal. In one aspect, the computer can be a central processing unit (CPU), or a field programmable gate array (FPGA), where the computer operates a control algorithm. Further, the electronic feedback loop receives the output power signal and an output signal from the computer, where an output signal from the electronic feedback loop is configured to a control a position of the piston(s).

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.

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.