A process and system of extracting useful work or electricity from a thermal source, wherein heat energy from the thermal source is used in the form of a heated collection fluid; a first side of a heat exchanger is filled with a liquid or supercritical working fluid; fluid flow out of the first side of the heat exchanger is closed such that a fixed volume of the working fluid is maintained in the first side; the heated collection fluid flowed through a second side of the heat exchanger that is adjacent to the first side to affect a transfer of heat from the heated collection fluid to the fixed volume of the working fluid to raise its temperature and pressure; the pressurized working fluid is released from the first side of the heat exchanger upon the working fluid reaching a threshold state; a flow of the pressurized working fluid is directed to an expander capable of converting the kinetic energy of the pressurized working fluid into useful work or electricity; and the foregoing steps are repeated. A plurality of such operably coupled heat exchangers may be used in a manner such that the timing of the pressurized working fluid from each heat exchanger to the expander is offset.

A process and system of extracting useful work or electricity from a thermal source, wherein heat energy from the thermal source is used in the form of a heated collection fluid; a first side of a heat exchanger is filled with a liquid or supercritical working fluid; fluid flow out of the first side of the heat exchanger is closed such that a fixed volume of the working fluid is maintained in the first side; the heated collection fluid flowed through a second side of the heat exchanger that is adjacent to the first side to affect a transfer of heat from the heated collection fluid to the fixed volume of the working fluid to raise its temperature and pressure; the pressurized working fluid is released from the first side of the heat exchanger upon the working fluid reaching a threshold state; a flow of the pressurized working fluid is directed to an expander capable of converting the kinetic energy of the pressurized working fluid into useful work or electricity; and the foregoing steps are repeated. A plurality of such operably coupled heat exchangers may be used in a manner such that the timing of the pressurized working fluid from each heat exchanger to the expander is offset.

A compressor for gaseous fluids comprises a positive displacement gear pump, as typically used for liquid transfer, modified to effect compression of gases. The pump inlet includes a main inlet plus multiple secondary inlets feeding inlet gases to gear voids spaced from and moving away from the main inlet. The pump outlet includes a main outlet plus multiple feedback passages feeding partially pressurized outlet gases to gear voids spaced from and moving toward the main outlet. The supplemental inlets and feedback passages increase both the throughput of the compressor and the amount of compression imparted to the gases.

A compressor for gaseous fluids comprises a positive displacement gear pump, as typically used for liquid transfer, modified to effect compression of gases. The pump inlet includes a main inlet plus multiple secondary inlets feeding inlet gases to gear voids spaced from and moving away from the main inlet. The pump outlet includes a main outlet plus multiple feedback passages feeding partially pressurized outlet gases to gear voids spaced from and moving toward the main outlet. The supplemental inlets and feedback passages increase both the throughput of the compressor and the amount of compression imparted to the gases.

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 cryogenic expander maximizes the energy absorbing capacity of bumpers that prevent the displacer or piston in a pneumatically driven expander from hitting the cold or warm end of a cylinder. A collar at the warm end of the piston which has the same outside diameter as the piston and a lip at the warm end that engages an O ring before the piston hits the cold end or bottom of the cylinder. The warm end of the collar also engages an O ring before the pistons hits the warm end or top of the cylinder. Having O rings that are near the maximum diameter of the cylinder maximizes the amount of energy they can absorb, and thus permits quiet operation of larger size expanders than prior designs.

A thermal energy storage apparatus, including: a block of a heat-absorbing material, the block defining at least one receptacle and being a contiguous block of compressed sintered graphite; and a phase change material stored in the or each receptacle, the phase change material being one that expands as it cools, wherein separation of side walls of the or each receptacle progressively increases as they extend upwardly from the base, whereby as the phase change material solidifies and expands it is urged upwardly to reduce pressure applied to the heat-absorbing material.

A thermal energy storage apparatus, including: a block of a heat-absorbing material, the block defining at least one receptacle and being a contiguous block of compressed sintered graphite; and a phase change material stored in the or each receptacle, the phase change material being one that expands as it cools, wherein separation of side walls of the or each receptacle progressively increases as they extend upwardly from the base, whereby as the phase change material solidifies and expands it is urged upwardly to reduce pressure applied to the heat-absorbing material.

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 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.