A split-cycle internal combustion engine is provided with an engine block and an expansion section having a plurality of expansion cylinders and a rotating drive shaft, which is supported by a first portion of the engine block and is operated by the expansion cylinders; the engine is further provided with a compression section having a volumetric compressor with a rotating driven shaft, which is supported by a second potion of the engine block and is distinct and spaced apart from the rotating drive shaft; the volumetric compressor has at least one compression cylinder extending along an axis, which is inclined relative to the axes of the expansion cylinders so as to form an angle.

A split-cycle internal combustion engine is provided with an engine block and an expansion section having a plurality of expansion cylinders and a rotating drive shaft, which is supported by a first portion of the engine block and is operated by the expansion cylinders; the engine is further provided with a compression section having a volumetric compressor with a rotating driven shaft, which is supported by a second potion of the engine block and is distinct and spaced apart from the rotating drive shaft; the volumetric compressor has at least one compression cylinder extending along an axis, which is inclined relative to the axes of the expansion cylinders so as to form an angle.

An engine assembly is provided with a split-cycle internal combustion engine having a compression section and an expansion section and with a cooling circuit for circulating a heat-exchange fluid; said fluid has a boiling temperature such that at least a fraction of the fluid changes phase from liquid to vapour flowing through the expansion section of the engine, when the latter operates in steady conditions; the circuit comprises a turbine arranged downstream of the engine so as to receive vapour and produce mechanical energy from the expansion of the vapour.

A split cycle internal combustion engine apparatus includes a combustion cylinder accommodating a combustion piston and a compression cylinder accommodating a compression piston. The apparatus is arranged to provide compressed fluid to the combustion cylinder. The compression cylinder is coupled to a first liquid coolant reservoir and a second liquid coolant reservoir. A controller is arranged to receive an indication of at least one parameter associated with the engine, and control delivery of at least one of the first liquid coolant from the first liquid coolant reservoir and the second liquid coolant from the second liquid coolant reservoir to the compression cylinder based on the indication of the at least one parameter such that the at least one liquid coolant vaporises into a gaseous phase during a compression stroke.

A split cycle internal combustion engine apparatus includes a combustion cylinder accommodating a combustion piston and a compression cylinder accommodating a compression piston. The apparatus is arranged to provide compressed fluid to the combustion cylinder. The compression cylinder is coupled to a first liquid coolant reservoir and a second liquid coolant reservoir. A controller is arranged to receive an indication of at least one parameter associated with the engine, and control delivery of at least one of the first liquid coolant from the first liquid coolant reservoir and the second liquid coolant from the second liquid coolant reservoir to the compression cylinder based on the indication of the at least one parameter such that the at least one liquid coolant vaporises into a gaseous phase during a compression stroke.

The engines include compression cylinders, combustion cylinders, an air rail, and a heat exchanger. The methods of operating a compression ignition engine include taking air into a compression cylinder of the engine, compressing the air in the compression cylinder to raise the pressure and temperature of the air, passing the compressed air through a heat exchanger, and from the heat exchanger into a combustion cylinder, further compressing the compressed air during a compression stroke of the combustion cylinder, igniting fuel in the combustion cylinder at or near the end of the compression stroke by compression ignition, followed by a power stroke, and opening an exhaust valve at the end of the power stroke and passing at least some of the exhaust in the combustion cylinder through the heat exchanger to heat air that has been compressed in the compression cylinder and is then passing through the heat exchanger.

The engines include compression cylinders, combustion cylinders, an air rail, and a heat exchanger. The methods of operating a compression ignition engine include taking air into a compression cylinder of the engine, compressing the air in the compression cylinder to raise the pressure and temperature of the air, passing the compressed air through a heat exchanger, and from the heat exchanger into a combustion cylinder, further compressing the compressed air during a compression stroke of the combustion cylinder, igniting fuel in the combustion cylinder at or near the end of the compression stroke by compression ignition, followed by a power stroke, and opening an exhaust valve at the end of the power stroke and passing at least some of the exhaust in the combustion cylinder through the heat exchanger to heat air that has been compressed in the compression cylinder and is then passing through the heat exchanger.

An engine including an exhaust bypass valve and an intake bypass valve. The exhaust bypass valve is disposed in an exhaust bypass channel connecting an outlet of an exhaust manifold and an exhaust outlet of a turbocharger to each other. The intake bypass valve is disposed in an intake bypass channel connecting an inlet of an intake manifold and an inlet of the turbocharger. An intake pressure sensor detects a pressure of the intake manifold. If an instruction value indicating an upper limit or a lower limit of the valve opening degree of the intake bypass valve is continuously output for a predetermined time or more, an engine control device determines that an abnormality occurs in at least one of the exhaust bypass valve and the intake bypass valve.

An opposed, free-piston engine includes a pair of adjacent cylinders, each extending from a first cylinder end to a second cylinder end along an elongate axis and having a first cylinder housing a first pair of opposed, free pistons including a first piston housed towards the first cylinder end and a second piston housed towards the second cylinder end; a second cylinder housing a second pair of opposed, free pistons having a third piston and a fourth piston; and a pair of link rods including a first link rod and a second link rod. The first link rod has a first link rod end and a second link rod end, the second link rod having a third link rod end and a fourth link rod end.

An opposed, free-piston engine includes a pair of adjacent cylinders, each extending from a first cylinder end to a second cylinder end along an elongate axis and having a first cylinder housing a first pair of opposed, free pistons including a first piston housed towards the first cylinder end and a second piston housed towards the second cylinder end; a second cylinder housing a second pair of opposed, free pistons having a third piston and a fourth piston; and a pair of link rods including a first link rod and a second link rod. The first link rod has a first link rod end and a second link rod end, the second link rod having a third link rod end and a fourth link rod end.