A free piston apparatus includes a piston receptacle in which a piston device having a piston is linearly reciprocable. The piston receptacle includes or forms a combustion chamber delimited by a wall arrangement forming a first opening and a second opening. The openings include an inlet opening for the supply of fresh gas and an outlet opening for the removal of exhaust gas for a uniflow scavenging of the combustion chamber. Movement of the piston device is controllable by a control device. The bottom dead center of the piston can be adjustable such that when the piston adopts the bottom dead center, the first opening is partially unblocked and partially blocked for adjusting a free cross sectional area of the first opening. An opening duration can also be adjustable. A method for operating a free piston apparatus includes controlling movement of a piston device with a control device.

A free piston apparatus includes a piston receptacle in which a piston device having a piston is linearly reciprocable. The piston receptacle includes or forms a combustion chamber delimited by a wall arrangement forming a first opening and a second opening. The openings include an inlet opening for the supply of fresh gas and an outlet opening for the removal of exhaust gas for a uniflow scavenging of the combustion chamber. Movement of the piston device is controllable by a control device. The bottom dead center of the piston can be adjustable such that when the piston adopts the bottom dead center, the first opening is partially unblocked and partially blocked for adjusting a free cross sectional area of the first opening. An opening duration can also be adjustable. A method for operating a free piston apparatus includes controlling movement of a piston device with a control device.

A free piston apparatus includes a piston receptacle in which a piston device having a piston is reciprocable along an axis. The piston receptacle includes or forms a combustion chamber delimited by a wall arrangement forming an inlet opening for the supply of fresh gas and an outlet opening for the removal of exhaust gas. Fresh gas is suppliable via a supply conduit. The free piston apparatus includes a housing for fresh gas which is connected to the supply conduit in a flow direction of the fresh gas being supplied. The housing forms a settling chamber for fresh gas which surrounds the piston receptacle at least in sections in the region of the inlet opening in a circumferential direction of the axis. The settling chamber opens into the combustion chamber via the inlet opening.

A free piston apparatus includes a piston receptacle in which a piston device having a piston is reciprocable along an axis. The piston receptacle includes or forms a combustion chamber delimited by a wall arrangement forming an inlet opening for the supply of fresh gas and an outlet opening for the removal of exhaust gas. Fresh gas is suppliable via a supply conduit. The free piston apparatus includes a housing for fresh gas which is connected to the supply conduit in a flow direction of the fresh gas being supplied. The housing forms a settling chamber for fresh gas which surrounds the piston receptacle at least in sections in the region of the inlet opening in a circumferential direction of the axis. The settling chamber opens into the combustion chamber via the inlet opening.

A control system for a pre-mixture compression-ignition engine is provided, configured such that in a first combustion mode, the control unit controls the fuel injection valve to have a fuel amount within a mixture gas in an outer circumferential portion of the combustion chamber larger than in the center portion, the swirl generating part to generate a swirl flow in the outer circumferential portion, and the spark plug to ignite the mixture gas in the center portion. In a second combustion mode, the control unit controls the fuel injection valve to start a fuel injection on intake stroke so that the mixture gas is formed in the entire combustion chamber, the swirl generating part so that a swirl flow becomes weaker than in the first combustion mode, and the spark plug to ignite the mixture gas before CTDC.

free-piston engine power plant incorporating a first combustion cylinder having a first combustion piston, a fluid expander having an expansion cylinder with an expander piston therein, the expander piston reciprocating in unison with the first combustion piston, a bottoming cycle having a working fluid and a heat exchanger.

An object of the present invention is to provide a method and a system for implementing the method so as to alleviate the disadvantages of a reciprocating combustion engine and gas turbine when generating power. The invention is based on the idea of arranging a multifunction valve inside a combustion chamber to create more favourable favorable conditions for combustion process. The multifunction valve may act as an output valve, but it can also provide additional final compression to contents of the compression chamber and it may even capture part of energy released in a combustion process.

An object of the present invention is to provide a method and a system for implementing the method so as to alleviate the disadvantages of a reciprocating combustion engine and gas turbine when generating power. The invention is based on the idea of arranging a multifunction valve inside a combustion chamber to create more favourable favorable conditions for combustion process. The multifunction valve may act as an output valve, but it can also provide additional final compression to contents of the compression chamber and it may even capture part of energy released in a combustion process.

A combined heat and power microgrid system is provided that stores energy in the form of compressed air that can then be utilized as needed in the form, of electricity. The compressed air may be generated with energy from multiple electrical energy sources, such as renewable energy sources. The energy stored as compressed air/heat is used to charge a battery by utilizing a pulley system and a barrel housing that transfers kinetic energy generated by the release of the compressed air to an array of piezoelectric generators that can produce electricity, which is stored in the second battery. In addition, water may be extracted from the compressed air storage tank. In this way, energy produced by the renewable sources can be accessed during periods of high need or low production and water may be collected.

A homogeneous charge compression ignition free-piston linear generator is disclosed. The linear generator includes a housing having cylinders at opposite ends. A double-ended piston assembly is to move linearly in the housing to convert kinetic energy of the piston assembly into electrical energy, and to enable conversion of electrical energy into kinetic energy of the piston assembly. Sensors measure one or more states of the cylinders and/or piston assembly, and a controller controls the linear generator based on the sensor data.