A free piston Stirling engine with a heat exchanger that has an inner component part assembled within an outer component part. The outer component part has a tubular outer wall and circumferentially spaced ridges that extend radially inward from the tubular outer wall and are separated from each other by inward opening slots. The inner component part has a tubular inner wall and circumferentially spaced ridges that extend outward from the inner tubular wall and are separated from each other by outward opening slots. The ridge widths of the outer and inner component parts are less than the slot widths of the corresponding slots into which they fit. The two component parts are assembled with the ridges of each component part extending into the slots of the other component part to form gas passages between interfacing sidewall surfaces of the ridges.

A free-piston Stirling cycle engine includes a hermetically sealed pressure housing with a working section and at least one displacement section adjacent to the working section. At least one working piston, which forms part of a linear generator, is movably arranged in the interior of the working section and a regenerator is arranged in the at least one displacement section such that mechanical work can be performed by the working piston when the pressure housing is filled with a working gas and under the influence of a temperature difference between the displacement section with an elevated temperature and the remainder of the pressure housing with a lower temperature and the mechanical work can be converted into electrical energy by the linear generator.

An efficient stirling engine comprises an expansion chamber with a heater and a compression chamber with a cooler, wherein the two chambers are connected through a regenerator. A passage between the heater and the expansion chamber is provided with a first valve system, a passage between the cooler and the compression chamber is provided with a second valve system, the first valve system can close or open the passage between the heater and the expansion chamber, and the second valve system can close or open the passage between the cooler and the compression chamber. After adopting the structure above, when a heating end is heated to expand, a cooling end at the other end is closed, and on the contrary, when the cooling end is cooled to shrink, the heating end at the other end is closed, so that the heating energy is fully used, so as to increase the efficiency of the stirling engine.

An efficient stirling engine comprises an expansion chamber with a heater and a compression chamber with a cooler, wherein the two chambers are connected through a regenerator. A passage between the heater and the expansion chamber is provided with a first valve system, a passage between the cooler and the compression chamber is provided with a second valve system, the first valve system can close or open the passage between the heater and the expansion chamber, and the second valve system can close or open the passage between the cooler and the compression chamber. After adopting the structure above, when a heating end is heated to expand, a cooling end at the other end is closed, and on the contrary, when the cooling end is cooled to shrink, the heating end at the other end is closed, so that the heating energy is fully used, so as to increase the efficiency of the stirling engine.

A combined power generation system based on geothermal energy and solar energy and a power generation method thereof are provided. The system includes: at least three injection wells; at least three production wells; at least three connected paths in a reservoir connected with gas outlets of the at least three injection wells and gas inlets of the at least three production wells; at least three geothermal turbines having gas inlets connected with gas outlets of the at least three production wells; a gas cooler; a first regenerator having a high-pressure gas inlet connected with a gas outlet of the upmost production well; a second regenerator having a high-pressure gas inlet connected with one geothermal turbine; a solar receiver having a gas inlet connected with the second regenerator; and a solar turbine having a gas inlet connected with the solar receiver and a gas outlet connected with the second regenerator.

A combined power generation system based on geothermal energy and solar energy and a power generation method thereof are provided. The system includes: at least three injection wells; at least three production wells; at least three connected paths in a reservoir connected with gas outlets of the at least three injection wells and gas inlets of the at least three production wells; at least three geothermal turbines having gas inlets connected with gas outlets of the at least three production wells; a gas cooler; a first regenerator having a high-pressure gas inlet connected with a gas outlet of the upmost production well; a second regenerator having a high-pressure gas inlet connected with one geothermal turbine; a solar receiver having a gas inlet connected with the second regenerator; and a solar turbine having a gas inlet connected with the solar receiver and a gas outlet connected with the second regenerator.

Multiple free-piston stirling-cycle machine modules are connected together in double-acting configurations that may be used as engines or heat pumps and scaled to any power level by varying the number of modules. Reciprocating piston assemblies oriented in balanced pairs reduce vibration forces. There are no buffer spaces. Linear motors or generators are packaged inside piston cavities entirely within the module working spaces. The external heat-accepting and heat-rejecting surfaces in one embodiment are directed along inward-facing and outward facing cylinders, and in another embodiment along parallel planes, simplifying thermal connections to the external heat source and sink.

Multiple free-piston stirling-cycle machine modules are connected together in double-acting configurations that may be used as engines or heat pumps and scaled to any power level by varying the number of modules. Reciprocating piston assemblies oriented in balanced pairs reduce vibration forces. There are no buffer spaces. Linear motors or generators are packaged inside piston cavities entirely within the module working spaces. The external heat-accepting and heat-rejecting surfaces in one embodiment are directed along inward-facing and outward facing cylinders, and in another embodiment along parallel planes, simplifying thermal connections to the external heat source and sink.

A powering system includes an engine having a first side and an interface for providing heat to the first side of the engine. The interface includes a combustor having a combustion chamber positioned at least partially in an enclosure that receives a fuel and an oxidizer for combustion of the fuel and oxidizer into a combustion product. A conduit is connected to the combustion chamber for receiving the combustion product. A heat transfer fluid is positioned in the enclosure and engages an external surface of the combustion chamber and an external surface of the conduit within the enclosure. The heat transfer fluid is heated by the combustion product via the external surface of the combustion chamber and the external surface of the conduit such that the heat transfer fluid transfers heat to the first side of the engine. The heat transfer fluid may thereby decouples the engine from the combustor.

A powering system includes an engine having a first side and an interface for providing heat to the first side of the engine. The interface includes a combustor having a combustion chamber positioned at least partially in an enclosure that receives a fuel and an oxidizer for combustion of the fuel and oxidizer into a combustion product. A conduit is connected to the combustion chamber for receiving the combustion product. A heat transfer fluid is positioned in the enclosure and engages an external surface of the combustion chamber and an external surface of the conduit within the enclosure. The heat transfer fluid is heated by the combustion product via the external surface of the combustion chamber and the external surface of the conduit such that the heat transfer fluid transfers heat to the first side of the engine. The heat transfer fluid may thereby decouples the engine from the combustor.