Abstract: A compressed air energy storage system is described, including a compressor fluidly coupled to a compressed air reservoir and an expansion train including at least a first turbine. The system further includes an electric machine aggregate configured: for converting electric power into mechanical power and driving the compressor therewith during the energy storing mode; and for converting mechanical power produced by the expansion train into electric power during the power production mode. A combustor is configured for receiving fuel and compressed air and producing combustion gas, and for supplying the combustion gas to the first turbine.

Abstract: A compressed-air energy-storage system, comprising: a variable-nozzle expander configured to receive an airflow at a first pressure and partially expand said airflow at a second pressure, said second pressure being lower than said first pressure, expansion of said airflow in said variable-nozzle expander producing useful mechanical power; a heat generator component configured to receive a fuel and a partially expanded airflow from the variable-nozzle expander; and a turbine configured to receive combustion gas from the heat generator component and expand the combustion gas producing useful mechanical power.

Abstract: A compressed air energy storage system is described, including a compressor fluidly coupled to a compressed air reservoir and an expansion train including at least a first turbine. The system further includes an electric machine aggregate configured: for converting electric power into mechanical power and driving the compressor therewith during the energy storing mode; and for converting mechanical power produced by the expansion train into electric power during the power production mode. A combustor is configured for receiving fuel and compressed air and producing combustion gas, and for supplying the combustion gas to the first turbine.

Abstract: A compressed-air energy-storage system, comprising: a variable-nozzle expander configured to receive an airflow at a first pressure and partially expand said airflow at a second pressure, said second pressure being lower than said first pressure, expansion of said airflow in said variable-nozzle expander producing useful mechanical power; a heat generator component configured to receive a fuel and a partially expanded airflow from the variable-nozzle expander; and a turbine configured to receive combustion gas from the heat generator component and expand the combustion gas producing useful mechanical power.

Abstract: A poppet valve is disclosed that includes a valve body, a poppet guide disposed inside the valve body so as to form a flow passage from an inlet to an outlet of the valve, a poppet shutter disposed inside the poppet guide, and a biasing member to bias the poppet shutter away from the poppet guide toward an inside surface of the flow inlet so as to block the flow passage. The poppet valve further includes at least one discharge hole placing an inner chamber of the poppet guide in flow communication with a region of low static pressure of the flow passage. A method for reducing a closing pressure force acting on a poppet shutter of a poppet valve is also disclosed.

Abstract: A poppet valve is disclosed that include a valve body, a poppet guide disposed inside the valve body so as to form a flow passage from a flow inlet to a flow outlet of the valve, a poppet shutter disposed inside the poppet guide, and a converging-diverging flow passage formed by a portion of an outer surface of the poppet shutter and a corresponding portion of an inner surface of valve body. A method for reducing a closing pressure force acting on a poppet shutter of a poppet valve is also disclosed.

Abstract: A poppet valve is disclosed that include a valve body, a poppet guide disposed inside the valve body so as to form a a flow passage from a flow inlet to a flow outlet of the valve, a poppet shutter disposed inside the poppet guide, and a converging-diverging flow passage formed by a portion of an outer surface of the poppet shutter and a corresponding portion of an inner surface of valve body. A method for reducing a closing pressure force acting on a poppet shutter of a poppet valve is also disclosed.

Abstract: A poppet valve is disclosed that includes a valve body, a poppet guide disposed inside the valve body so as to form a flow passage from an inlet to an outlet of the valve, a poppet shutter disposed inside the poppet guide, and a biasing member to bias the poppet shutter away from the poppet guide toward an inside surface of the flow inlet so as to block the flow passage. The poppet valve further includes at least one discharge hole placing an inner chamber of the poppet guide in flow communication with a region of low static pressure of the flow passage. A method for reducing a closing pressure force acting on a poppet shutter of a poppet valve is also disclosed.

Abstract: A rotor for the second phase of a low-pressure turbine has a series of blades each defined by coordinates of a discreet combination of points, in a Cartesian reference system (X, Y,Z), wherein the axis (Z) is a radial axis intersecting the central axis of the turbine. The profile of each blade identified by means of a series of closed intersection curves between the profile itself and planes (X, Y) lying at distances (Z) from the central axis. Each blade an average throat angle defined by the cosine arc of the ratio between the average throat length at mid-height of the blade and the circumferential pitch evaluated at the radius of the average throat point; the average throat single ranges from 54.9° to 57.9°.

Abstract: A stator for the second phase of a low-pressure turbine has a series of blades each defined by coordinates of a discreet combination of points, in a Cartesian reference system (X, Y, Z), wherein the axis (Z) is a radial axis intersecting the central axis of the turbine. The profile of each blade is identified by means of a series of closed intersection curves between the profile itself and planes (X, Y) lying at distances (Z) from the central axis. Each blade has an average throat angle defined by the cosine arc of the ratio between the average throat length at mid-height of the blade and the circumferential pitch evaluated at the radius of the average throat point; the average throat angle ranges from 57.8° to 60.8°.

Abstract: Rotor for the second phase of a low-pressure turbine having a series of blades (1) each defined by coordinates of a discreet combination of points, in a Cartesian reference system (X,Y,Z), wherein the axis (Z) is a radial axis intersecting the central axis of the turbine. The profile of each blade (1) is identified by means of a series of closed intersection curves (20) between the profile itself and planes (X,Y) lying at distances (Z) from the central axis. Each blade (1) has an average throat angle defined by the cosine arc of the ratio between the average throat length at mid-height of the blade and the circumferential pitch evaluated at the radius of the average throat point; the average throat angle ranges from 54.9° to 57.9°.

Abstract: Stator for the second phase of a low-pressure turbine having a series of blades (1) each defined by coordinates of a discreet combination of points, in a Cartesian reference system (X,Y,Z), wherein the axis (Z) is a radial axis intersecting the central axis of the turbine. The profile of each blade (1) is identified by means of a series of closed intersection curves (20) between the profile itself and planes (X,Y) lying at distances (Z) from the central axis. Each blade (1) has an average throat angle defined by the cosine arc of the ratio between the average throat length at mid-height of the blade and the circumferential pitch evaluated at the radius of the average throat point; the average throat angle ranges from 57.8° to 60.8°.