A hot-air engine (10) includes a compressor (12), a heating chamber (14), a rotary displacement type working engine (16) and a drive means (22). The compressor (12) has an inlet (12a) and an outlet (12b). The heating chamber (14) has an inlet (14a), in fluid communication with the outlet (12b) of the compressor (12), and an outlet (14b). The working engine (16) has an inlet (16a), in fluid communication with the outlet (14b) of the heating chamber (14), and an output shaft (16a). The drive means (22) connects the working engine (16) to the compressor (12) such that operation of the working engine (16) causes operation of the compressor (12).

A hot-air engine (10) includes a compressor (12), a heating chamber (14), a rotary displacement type working engine (16) and a drive means (22). The compressor (12) has an inlet (12a) and an outlet (12b). The heating chamber (14) has an inlet (14a), in fluid communication with the outlet (12b) of the compressor (12), and an outlet (14b). The working engine (16) has an inlet (16a), in fluid communication with the outlet (14b) of the heating chamber (14), and an output shaft (16a). The drive means (22) connects the working engine (16) to the compressor (12) such that operation of the working engine (16) causes operation of the compressor (12).

Embodiments relate generally to energy storage systems, and in particular to energy storage systems using compressed gas as an energy storage medium. In various embodiments, a compressed gas storage system may include a plurality of stages to convert energy into compressed gas for storage, and then to recover that stored energy by gas expansion. In certain embodiments, a stage may comprise a reversible compressor/expander having a reciprocating piston. Pump designs for introducing liquid for heat exchange with the gas, are described. Gas flow valves featuring shroud and/or curtain portions, are also described.

Embodiments relate generally to energy storage systems, and in particular to energy storage systems using compressed gas as an energy storage medium. In various embodiments, a compressed gas storage system may include a plurality of stages to convert energy into compressed gas for storage, and then to recover that stored energy by gas expansion. In certain embodiments, a stage may comprise a reversible compressor/expander having a reciprocating piston. Pump designs for introducing liquid for heat exchange with the gas, are described. Gas flow valves featuring shroud and/or curtain portions, are also described.

A heat/acoustic wave conversion unit includes a heat/acoustic wave conversion component and two heat exchangers. Hydraulic diameter HD of the cells in the heat/acoustic wave conversion component is 0.4 mm or less, and a ratio HD/L of HD to the length L of the heat/acoustic wave conversion component is from 0.005 to 0.02. One of the heat exchangers includes a heat-exchanging honeycomb structure and an annular tube that surrounds a circumferential face of the heat-exchanging honeycomb structure. The annular tube includes a structure body that is disposed in the channel to increase a contact area with the heated fluid, an inflow port into which the heated fluid flows, and an outflow port through which the heated fluid flows out. At least one of the heat-exchanging honeycomb structure and the structure body is made of a ceramic material that contains SiC as a main component.

A heat/acoustic wave conversion unit includes a heat/acoustic wave conversion component and two heat exchangers. Hydraulic diameter HD of the cells in the heat/acoustic wave conversion component is 0.4 mm or less, and a ratio HD/L of HD to the length L of the heat/acoustic wave conversion component is from 0.005 to 0.02. One of the heat exchangers includes a heat-exchanging honeycomb structure and an annular tube that surrounds a circumferential face of the heat-exchanging honeycomb structure. The annular tube includes a structure body that is disposed in the channel to increase a contact area with the heated fluid, an inflow port into which the heated fluid flows, and an outflow port through which the heated fluid flows out. At least one of the heat-exchanging honeycomb structure and the structure body is made of a ceramic material that contains SiC as a main component.

The present invention concerns an external heat source engine comprising: —at least one cylinder (2), —a piston (3) that is movable back and forth in the cylinder, —a cylinder head (4) defining a working chamber (5) with the piston and the cylinder, —a heat exchanger (6) for exchanging heat between a working gas and a heat-transfer fluid, —a distribution comprising two rotary slide valves (20, 30) mounted so as to be able to rotate in the cylinder head and bringing the working chamber selectively into communication with the following resources: •a working gas inlet (A), •a cold end (B) of the exchanger, •a hot end (C) of the exchanger, •an exhaust (D). The slide valves (20, 30) comprise internal passages that open through the side wall of same through at least one opening that communicates selectively with the working chamber (5) via at least one opening formed in the cylinder head (4).

The present invention concerns an external heat source engine comprising: —at least one cylinder (2), —a piston (3) that is movable back and forth in the cylinder, —a cylinder head (4) defining a working chamber (5) with the piston and the cylinder, —a heat exchanger (6) for exchanging heat between a working gas and a heat-transfer fluid, —a distribution comprising two rotary slide valves (20, 30) mounted so as to be able to rotate in the cylinder head and bringing the working chamber selectively into communication with the following resources: •a working gas inlet (A), •a cold end (B) of the exchanger, •a hot end (C) of the exchanger, •an exhaust (D). The slide valves (20, 30) comprise internal passages that open through the side wall of same through at least one opening that communicates selectively with the working chamber (5) via at least one opening formed in the cylinder head (4).

Internal combustion engines, including engines producing power from solid or slow burning fuel(s), such as biological-based or petroleum-based fuels, wood, corn, biomass, coal, and waste products, and/or possibly other liquid or gaseous fluids, as well as methods for operating or implementing such engines, are disclosed herein. In an example embodiment, the engine includes a crankshaft, a piston, a cylinder having an internal cavity and several ports, and an assembly having a chamber having a first region within which solid fuel can be situated and combusted. The assembly further includes a diverter valve so that, depending upon a setting of the valve and during engine operation, first and second amounts of compressed air respectively proceed to the first region and to bypass the first region, and a combination of combustion products and the second amount proceeds via one of the ports to the part of the internal cavity.

Internal combustion engines, including engines producing power from solid or slow burning fuel(s), such as biological-based or petroleum-based fuels, wood, corn, biomass, coal, and waste products, and/or possibly other liquid or gaseous fluids, as well as methods for operating or implementing such engines, are disclosed herein. In an example embodiment, the engine includes a crankshaft, a piston, a cylinder having an internal cavity and several ports, and an assembly having a chamber having a first region within which solid fuel can be situated and combusted. The assembly further includes a diverter valve so that, depending upon a setting of the valve and during engine operation, first and second amounts of compressed air respectively proceed to the first region and to bypass the first region, and a combination of combustion products and the second amount proceeds via one of the ports to the part of the internal cavity.