The present invention relates to a multi-stage Stirling cycle machine and a steady-state operating parameter control method therefor. In the Stirling cycle machine, a mechanical energy input piston, a mechanical energy transfer double-acting free piston and a mechanical energy output piston constitute a plurality of Stirling working units which are arranged in stages. The mechanical energy input piston is connected to a mechanical energy input apparatus, and the mechanical energy output piston is connected to a mechanical energy output apparatus. When the Stirling cycle machine in the present invention is used as an engine, a relatively small amount of mechanical energy is input into a mechanical energy input piston in a set of pistons, the mechanical energy is amplified by a multi-stage Stirling unit, and a relatively large amount of mechanical energy is then output by a mechanical energy output piston. In the present invention, the required piston motion mode is realized by means of parameter calculation, selection and design, such that the multi-stage Stirling cycle machine can adapt to changes in an input condition and adjust an output power as required. The device in the present invention has a simple structure, a good adjustment performance, a small mechanical loss and a small deadvolume, is suitable for use with a large-diameter piston, and can be widely applied to waste heat power generation and distributed energy and renewable energy power generation.

An integrated wind and solar solution is provided, including a solar energy collection assembly (100) and a vertical axis wind turbine (400), combined to provide an integrated power output. In preferred embodiments, the vertical axis wind turbine is positioned above the solar energy collection assembly. Concentrating solar mirror collectors (116) are used to direct sunlight to a heat engine (250), which converts the collected heat energy into rotary motion. Rotary motion from the heat engine and from the vertical axis wind turbine preferably are on the same rotating axis (600), to facilitate load sharing between these two sources. A dual axis azimuth-altitude solar panel alignment tracking system is used in order to boost the energy conversion capability of the solar energy collectors.

An engine comprising: a sealed and rigid case containing a liquid and a work mixture of gas and steam from the liquid, a heat source able to heat the liquid, a cold source able to cool the work mixture, a movable device positioned within the case, which can move between a first position where the movable device minimize the contact between the work mixture and the cold source, and maximize the contact between the liquid and the work mixture, and a second position where the movable device maximize the contact between the work mixture and the cold source, and minimize the contact between the liquid and the work mixture, an actuator able to move the movable device from the first position to the second position and vice versa.

A thermal energy recovery system. The system includes a Stirling engine having a burner thermal energy output. Also, a superheater mechanism for heating the thermal energy output and an expansion engine coupled to a generator. The expansion engine converts the thermal energy output from the burner to mechanical energy output. The generator converts mechanical energy output from the expansion engine to electrical energy output. The expansion engine may also includes vapor output. Some embodiments of the system further include a condenser for condensing the vapor output, a pump for pumping the vapor output and a boiler in fluid communication with the pump. The pump pumps the vapor output to the boiler.

A Stirling engine can take advantage of adiabatic compression (which heats working gas leaving the cold cylinder) and adiabatic expansion (which cools working gas leaving the hot cylinder) to increase efficiency. In some implementations, partially-heated gas leaving the cold cylinder and partially-cooled gas leaving the hot cylinder can be routed directly to a regenerator using bypass paths that are opened using one-way valves. The resultant relatively reduced temperature difference across the regenerator, e.g., as compared to a typical Stirling engine, can reduce thermal loss and improve efficiency. In some implementations, the compression ratios of the Stirling engine can be adjusted such that the temperature of the adiabatic heated gas is the same or higher than the temperature of the adiabatic cooled temperatures, thus eliminating the need for a regenerator.

A Stirling engine includes a working cylinder defining a working cylinder chamber with a reciprocatingly-arranged working piston and a heater fluidly communicating with the working cylinder chamber through a working gas channel. The engine includes a first heat exchanger extending from a head of a displacer cylinder into the heater, a second heat exchanger formed by a regenerator arranged outside the heater, and a third heat exchanger formed by a cooler arranged between the regenerator and the working cylinder chamber. At any point along the working gas channel, as seen cross-wise to an assumed working gas flow direction through the working gas channel, the cross section area of the working gas channel defined by the first, second and third heat exchangers is within the range of the medium cross section area of the working gas channel +/−10%.

A method for pressurisation of a working gas in a Stirling engine assembly for use in a thermal energy plant, the Stirling engine assembly including: a Stirling engine including an expansion cylinder and a compression cylinder, wherein the expansion and compression cylinders are configured in a V-arrangement; a regenerator; a cooler and a heater; an accumulator, the accumulator being in fluidic connection with the expansion and/or compression cylinders of the Stirling engine; and a low pressure receptacle including the working gas. The method includes: providing working gas to the accumulator from the low pressure receptacle; providing a pressurisation fluid to the accumulator to reduce the volume for the working gas in the accumulator, thereby increasing the pressure of the working gas in the accumulator; and displacing the pressurised working gas from the accumulator to the expansion and/or compression cylinder.

According to an embodiment of a hot air engine, the hot air engine includes a transmission with a connecting rod and a double-acting step piston. The double-acting step piston has a first section with a larger diameter and a second section with a smaller diameter, and is arranged in a cylinder. The double-acting step piston is at least partially hollow and the connecting rod extends through the second section and is articulatedly connected in the first section of the double-acting step piston. The double-acting step piston has sealing rings both in the first section and in the second section.

A method for pressurisation of a working gas in a Stirling engine assembly for use in a thermal energy plant, the Stirling engine assembly including: a Stirling engine including an expansion cylinder and a compression cylinder, wherein the expansion and compression cylinders are configured in a V-arrangement; a regenerator; a cooler and a heater; an accumulator, the accumulator being in fluidic connection with the expansion and/or compression cylinders of the Stirling engine; and a low pressure receptacle including the working gas. The method includes: providing working gas to the accumulator from the low pressure receptacle; providing a pressurisation fluid to the accumulator to reduce the volume for the working gas in the accumulator, thereby increasing the pressure of the working gas in the accumulator; and displacing the pressurised working gas from the accumulator to the expansion and/or compression cylinder.

A Stirling engine is described which, in accordance with a first exemplary embodiment, has a transmission with a connecting rod and a double-acting step piston which is arranged in a cylinder. The step piston has a first section with a greater diameter and a second section with a smaller diameter, and is at least partially hollow. The connecting rod runs on the inside through the second section, and is connected in an articulated manner in the first section of the step piston.