Abstract: In some embodiments, split-cycle engines are disclosed that are capable of operating in a normal firing mode in which a firing stroke is performed in the expansion cylinder only on every other rotation of the crankshaft. Fuel can be injected directly into the expansion cylinder during the non-firing rotation of the crankshaft over a period of time greater than what is possible with traditional split-cycle engines. A number of other advantages are associated with such engines. In some embodiments, two expansion cylinders can be provided such that a firing stroke is performed on every rotation of the crankshaft, even though each individual expansion cylinder only performs a firing stroke on every other rotation of the crankshaft. Air hybridized and/or Millerized variations of these engines, as well as various cylinder arrangements, are also disclosed herein.

Abstract: In some embodiments, split-cycle engines are disclosed that are capable of operating in a normal firing mode in which a firing stroke is performed in the expansion cylinder only on every other rotation of the crankshaft. Fuel can be injected directly into the expansion cylinder during the non-firing rotation of the crankshaft over a period of time greater than what is possible with traditional split-cycle engines. A number of other advantages are associated with such engines. In some embodiments, two expansion cylinders can be provided such that a firing stroke is performed on every rotation of the crankshaft, even though each individual expansion cylinder only performs a firing stroke on every other rotation of the crankshaft. Air hybridized and/or Millerized variations of these engines, as well as various cylinder arrangements, are also disclosed herein.

Abstract: A number of exemplary power generation systems and methods are disclosed herein. In some embodiments, a compressed air energy storage system, optionally with split-cycle engine technology, is used to store energy obtained from the grid during off-peak hours and to supply stored energy to the grid and/or to an end user during on-peak hours. The system can include heat recovery features and can supply heat to the end user. In some embodiments, a generator system is used to provide power to an end user and to the grid. The generator can be maintained in a high efficiency operating range (e.g., at elevated or full load), even when the generator output exceeds the end user's demand, with any excess generated power being fed to the grid.

Abstract: In some embodiments, split-cycle engines are disclosed that are capable of operating in a normal firing mode in which a firing stroke is performed in the expansion cylinder only on every other rotation of the crankshaft. Fuel can be injected directly into the expansion cylinder during the non-firing rotation of the crankshaft over a period of time greater than what is possible with traditional split-cycle engines. A number of other advantages are associated with such engines. In some embodiments, two expansion cylinders can be provided such that a firing stroke is performed on every rotation of the crankshaft, even though each individual expansion cylinder only performs a firing stroke on every other rotation of the crankshaft. Air hybridized and/or Millerized variations of these engines, as well as various cylinder arrangements, are also disclosed herein.

Abstract: A split-cycle air hybrid engine with improved efficiency is disclosed in which the centerline of a compression cylinder is positioned at a non-zero angle with respect to the centerline of an expansion cylinder such that the engine has a V-shaped configuration. In one embodiment, the centerlines of the respective cylinders intersect an axis parallel to, but offset from, the axis of rotation of the crankshaft. Modular crossover passages, crossover passage manifolds, and associated air reservoir valve assemblies and thermal regulation systems are also disclosed.

Abstract: In some embodiments, systems are provided in which electric power generated from a renewable energy source such as a solar or wind power system during low demand periods is used to drive an electric motor which turns an air hybrid split-cycle engine. The split-cycle engine operates in AC mode during this time to compress air into a storage tank. Later, during high demand periods, compressed air stored in the tank and added fuel are fed to the split-cycle engine, which operates in AEF mode. The work generated by the split-cycle engine turns a generator to produce electric power. When the supply of compressed air stored in the storage tank is depleted, the split-cycle engine can operate in an NF mode to serve as a backup generator, or in an FC mode to serve as a backup generator while simultaneously recharging the air storage tank.

Abstract: A split-cycle engine includes a crankshaft rotatable about a crankshaft axis. A compression piston is slidably received within a compression cylinder and operatively connected to the crankshaft such that the compression piston reciprocates through intake and compression strokes during a single rotation of the crankshaft. An expansion piston is slidably received within an expansion cylinder and operatively connected to the crankshaft such that the expansion piston reciprocates through expansion and exhaust strokes during a single rotation of the crankshaft. A crossover passage interconnects the expansion and compression cylinders. The crossover passage includes crossover compression (XovrC) and crossover expansion (XovrE) valves defining a pressure chamber therebetween. At least one of the XovrC and XovrE valves is a balanced valve.

Abstract: A split-cycle engine includes a rotatable crankshaft. A compression piston is slidably received within a compression cylinder and operatively connected to the crankshaft such that the compression piston reciprocates through an intake stroke and a compression stroke during a single rotation of the crankshaft. An expansion piston is slidably received within an expansion cylinder and operatively connected to the crankshaft such that the expansion piston reciprocates through an expansion stroke and an exhaust stroke during a single rotation of the crankshaft. A crossover passage interconnects the expansion and compression cylinders. The crossover passage includes a crossover compression valve and a crossover expansion valve defining a pressure chamber therebetween. A pilot crossover valve is disposed between the crossover passage and the expansion cylinder.

Abstract: A split-cycle air hybrid engine with improved efficiency is disclosed in which the centerline of a compression cylinder is positioned at a non-zero angle with respect to the centerline of an expansion cylinder such that the engine has a V-shaped configuration. In one embodiment, the centerlines of the respective cylinders intersect an axis parallel to, but offset from, the axis of rotation of the crankshaft. Modular crossover passages, crossover passage manifolds, and associated air reservoir valve assemblies and thermal regulation systems are also disclosed.

Abstract: A split-cycle air hybrid engine operatively connects an air reservoir to a split cycle engine. A power piston is received within a power cylinder and operatively connected to a crankshaft such that the power piston reciprocates through an expansion stroke and an exhaust stroke during a single revolution of the crankshaft. A compression piston is received within a compression cylinder and operatively connected to the crankshaft such that the compression piston reciprocates through an intake stroke and a compression stroke in a single rotation of the crankshaft. The compression cylinder is selectively controllable to place the compression piston in a compression mode or an idle mode. An air reservoir is operatively connected between the compression cylinder and the power cylinder and selectively operable to receive compressed air from the compression cylinder and to deliver compressed air to the power cylinder for use in transmitting power to the crankshaft during engine operation.

Abstract: A waste heat recovery system for a split-cycle engine includes a heat exchange unit. An air compressor device is in communication with the heat exchange unit. A waste heat input receives waste heat from the engine and is in fluid communication with the heat exchange unit. An ambient air intake connected to the air compressor device draws air into the air compressor device. A compressed air outlet member on the air compressor device in fluid communication with a compression cylinder of the split-cycle engine delivers compressed air from the air compressor device to the engine. Engine waste heat is communicated to the heat exchange unit and energy from the waste heat is used to drive the air compressor device, causing the air compressor device to draw in ambient air through the ambient air intake, compress the ambient air, and deliver compressed air to the engine through the compressed air outlet.

Abstract: A split-cycle engine includes a rotatable crankshaft. A compression piston is slidably received within a compression cylinder and operatively connected to the crankshaft such that the compression piston reciprocates through an intake stroke and a compression stroke during a single rotation of the crankshaft. An expansion piston is slidably received within an expansion cylinder and operatively connected to the crankshaft such that the expansion piston reciprocates through an expansion stroke and an exhaust stroke during a single rotation of the crankshaft. A crossover passage interconnects the expansion and compression cylinders. The crossover passage includes a crossover compression valve and a crossover expansion valve defining a pressure chamber therebetween. A pilot crossover valve is disposed between the crossover passage and the expansion cylinder.

Abstract: A split-cycle air hybrid engine operatively connects an air reservoir to a split cycle engine. A power piston is received within a power cylinder and operatively connected to a crankshaft such that the power piston reciprocates through an expansion stroke and an exhaust stroke during a single revolution of the crankshaft. A compression piston is received within a compression cylinder and operatively connected to the crankshaft such that the compression piston reciprocates through an intake stroke and a compression stroke in a single rotation of the crankshaft. The compression cylinder is selectively controllable to place the compression piston in a compression mode or an idle mode. An air reservoir is operatively connected between the compression cylinder and the power cylinder and selectively operable to receive compressed air from the compression cylinder and to deliver compressed air to the power cylinder for use in transmitting power to the crankshaft during engine operation.

Abstract: A split-cycle air hybrid engine operatively connects an air reservoir to a split cycle engine. A power piston is received within a power cylinder and operatively connected to a crankshaft such that the power piston reciprocates through an expansion stroke and an exhaust stroke during a single revolution of the crankshaft. A compression piston is received within a compression cylinder and operatively connected to the crankshaft such that the compression piston reciprocates through an intake stroke and a compression stroke in a single rotation of the crankshaft. The compression cylinder is selectively controllable to place the compression piston in a compression mode or an idle mode. An air reservoir is operatively connected between the compression cylinder and the power cylinder and selectively operable to receive compressed air from the compression cylinder and to deliver compressed air to the power cylinder for use in transmitting power to the crankshaft during engine operation.

Abstract: A waste heat recovery system for a split-cycle engine includes a heat exchange unit. An air compressor device is in communication with the heat exchange unit. A waste heat input receives waste heat from the engine and is in fluid communication with the heat exchange unit. An ambient air intake connected to the air compressor device draws air into the air compressor device. A compressed air outlet member on the air compressor device in fluid communication with a compression cylinder of the split-cycle engine delivers compressed air from the air compressor device to the engine. Engine waste heat is communicated to the heat exchange unit and energy from the waste heat is used to drive the air compressor device, causing the air compressor device to draw in ambient air through the ambient air intake, compress the ambient air, and deliver compressed air to the engine through the compressed air outlet.

Abstract: A waste heat recovery system for a split-cycle engine includes a heat exchange unit. An air compressor device is in communication with the heat exchange unit. A waste heat input receives waste heat from the engine and is in fluid communication with the heat exchange unit. An ambient air intake connected to the air compressor device draws air into the air compressor device. A compressed air outlet member on the air compressor device in fluid communication with a compression cylinder of the split-cycle engine delivers compressed air from the air compressor device to the engine. Engine waste heat is communicated to the heat exchange unit and energy from the waste heat is used to drive the air compressor device, causing the air compressor device to draw in ambient air through the ambient air intake, compress the ambient air, and deliver compressed air to the engine through the compressed air outlet.

Abstract: A split-cycle engine includes a crankshaft rotatable about a crankshaft axis. A compression piston is slidably received within a compression cylinder and operatively connected to the crankshaft such that the compression piston reciprocates through intake and compression strokes during a single rotation of the crankshaft. An expansion piston is slidably received within an expansion cylinder and operatively connected to the crankshaft such that the expansion piston reciprocates through expansion and exhaust strokes during a single rotation of the crankshaft. A crossover passage interconnects the expansion and compression cylinders. The crossover passage includes crossover compression (XovrC) and crossover expansion (XovrE) valves defining a pressure chamber therebetween. At least one of the XovrC and XovrE valves is a balanced valve.

Abstract: A split-cycle air hybrid engine operatively connects an air reservoir to a split cycle engine. A power piston is received within a power cylinder and operatively connected to a crankshaft such that the power piston reciprocates through an expansion stroke and an exhaust stroke during a single revolution of the crankshaft. A compression piston is received within a compression cylinder and operatively connected to the crankshaft such that the compression piston reciprocates through an intake stroke and a compression stroke in a single rotation of the crankshaft. The compression cylinder is selectively controllable to place the compression piston in a compression mode or an idle mode. An air reservoir is operatively connected between the compression cylinder and the power cylinder and selectively operable to receive compressed air from the compression cylinder and to deliver compressed air to the power cylinder for use in transmitting power to the crankshaft during engine operation.

Abstract: A waste heat recovery system for a split-cycle engine includes a heat exchange unit. An air compressor device is in communication with the heat exchange unit. A waste heat input receives waste heat from the engine and is in fluid communication with the heat exchange unit. An ambient air intake connected to the air compressor device draws air into the air compressor device. A compressed air outlet member on the air compressor device in fluid communication with a compression cylinder of the split-cycle engine delivers compressed air from the air compressor device to the engine. Engine waste heat is communicated to the heat exchange unit and energy from the waste heat is used to drive the air compressor device, causing the air compressor device to draw in ambient air through the ambient air intake, compress the ambient air, and deliver compressed air to the engine through the compressed air outlet.

Abstract: A four stroke engine including a crankshaft. A power piston within a first cylinder connected to the crankshaft such that the power piston reciprocates through a power stroke and an exhaust stroke. A compression piston within a second cylinder is connected to the crankshaft such that the compression piston reciprocates through an intake stroke and a compression stroke. A gas passage interconnects the first and second cylinders and includes an inlet valve and an outlet valve defining a pressure chamber therebetween. An inlet manifold is in fluid communication with an inlet valve of the second cylinder. A bypass valve is in fluid communication with the second cylinder and the inlet manifold, wherein during a compression stroke the bypass valve allows a portion of the air to bypass the inlet valve and exhaust into the inlet manifold to provide a variable compression ratio.