A 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.

A load adaptive linear electrical generator system is provided for generating DC electrical power. The electrical generation system includes one or more power generation modules which will be selectively turned on or off and additively contribute power depending on the DC power demand. Each power generating module includes a pair of linear electrical generators connected to respective ones of a pair of internal combustion piston based power assemblies. The piston in the internal combustion assembly is connected to a magnet in the linear electrical generator. The piston/magnet assembly oscillates in a simple harmonic motion at a frequency dependent on a power load of the electrical generator. A stroke limiter constrains the piston/magnet assembly motion to preset limits.

Systems and methods for converting energy are provided. In one aspect, the system includes a closed cycle engine defining a cold side. The system also includes a bottoming-cycle loop. A pump is operable to move a working fluid along the bottoming-cycle loop. A cold side heat exchanger is positioned along the bottoming-cycle loop in a heat exchange relationship with the cold side of the closed cycle engine. A constant density heat exchanger is positioned along the bottoming-cycle loop downstream of the cold side heat exchanger and upstream of an expansion device. The constant density heat exchanger is operable to hold a volume of the working fluid flowing therethrough at constant density while increasing, via a heat source, the temperature and pressure of the working fluid. The expansion device receives the working fluid at elevated temperature and pressure and extracts thermal energy from the working fluid to produce work.

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.

Systems and methods for converting energy are provided. In one aspect, the system includes a closed cycle engine defining a cold side. The system also includes a bottoming-cycle loop. A pump is operable to move a working fluid along the bottoming-cycle loop. A cold side heat exchanger is positioned along the bottoming-cycle loop in a heat exchange relationship with the cold side of the closed cycle engine. A constant density heat exchanger is positioned along the bottoming-cycle loop downstream of the cold side heat exchanger and upstream of an expansion device. The constant density heat exchanger is operable to hold a volume of the working fluid flowing therethrough at constant density while increasing, via a heat source, the temperature and pressure of the working fluid. The expansion device receives the working fluid at elevated temperature and pressure and extracts thermal energy from the working fluid to produce work.

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.

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.

A system including a combustion engine is disclosed. The combustion engine includes a first cylinder orientated along a first axis. The combustion engine also includes a first piston, fitted within the first cylinder, to move in reciprocating motion by alternately moving in a first linear direction along the first axis responsive to a first power stroke or a second linear direction along the first axis responsive to a second power stroke. The combustion engine includes a tensile band affixed to a first end and a second end of the first piston. The first piston is to exert a first tensile force on the tensile band in the first linear direction in response to the first power stroke. The first piston is to exert a second tensile force on the tensile band in the second linear direction in response to the second power stroke.