Efficiency turbocharged engine system with bottoming cycle, and method of operation
AssigneeThe United States of America as represented by the Administrator of the U.S. Environmental Protection Agency
InventorCharles L. Gray, Jr.
Life of this patent
Estimating the term…
Abstract
A turbocharged engine system is configured to vaporize methanol using heat from exhaust gases and uses the vaporized methanol to drive the engine's turbocharger. The methanol may also be dissociated into hydrogen and carbon monoxide. After passing through the turbocharger, the vapor is injected into the engine by port injection. By selective timing of exhaust valves, the exhaust gases are separated into two streams, a first stream comprising gases ejected during exhaust blowdown, and a second stream of gases ejected during the remainder of the engine's exhaust stroke. The blowdown gases are employed to drive a separate turbine of the turbocharger.
Claims31
A method of providing boost for an internal combustion engine, comprising:
- combusting a mixture of fuel and oxygen in a cylinder of the engine, thereby driving a piston in the cylinder and imparting rotational energy to a crankshaft of the engine, and producing heated exhaust gases;
- transmitting the exhaust gases from an exhaust manifold of the engine to an inlet of a first heat exchanger and to an inlet of a first turbine;
- vaporizing and expanding a working fluid, wherein the working fluid is methanol, including vaporizing the working fluid in the first heat exchanger using heat from the exhaust gases, and expanding the vaporized working fluid by introducing the working fluid into the first turbine;
- compressing charge air with a compressor using energy released by the expansion of the working fluid, the compressor coupled to the first turbine via a drive shaft, and the compressor having an output in fluid communication with an intake port of the engine;
- and
- introducing the compressed charge air into the cylinder of the engine via the intake port of the engine.
A turbocharged engine system, comprising:
- an engine configured to operate by internal combustion and having a plurality of cylinders and an exhaust manifold;
- a plurality of port injectors configured to inject fuel into respective intake ports of the engine;
- an exhaust system extending from an output of the exhaust manifold to a tailpipe, configured to transmit exhaust gases from the exhaust manifold to the tailpipe, the exhaust system including:
- a first heat exchanger having an exhaust input coupled to the exhaust manifold of the engine and configured to transfer heat from exhaust gases of the engine to a working fluid, wherein the working fluid is methanol;
- and
- a first turbine having an input in fluid communication with a fluid output of the first heat exchanger and an output coupled to inputs of the port injectors, the first turbine being configured to expand the working fluid and convert energy released thereby to rotational energy;
- and
- a compressor coupled to the first turbine via a drive shaft, the compressor having an output in fluid communication with the intake orts of the en sine the compressor or configured to use the rotational energy transmitted by the first turbine to increase the pressure of charge air to be taken into the engine.
A turbocharged engine system, comprising:
- a four-stroke engine having a cylinder, a piston positioned within the cylinder, and a crankshaft coupled to the piston via a connecting rod, the engine configured to separate blowdown exhaust gases from gases that exit the cylinder during a majority of an exhaust stroke of the piston;
- a first exhaust manifold coupled to the engine and configured to receive the blowdown gases;
- a first turbine having an input coupled to the first exhaust manifold and configured to convert energy released during expansion of the blowdown gases to rotational energy;
- a second exhaust manifold coupled to the engine and configured to receive the gases that exit the cylinder during the majority of the exhaust stroke of the piston;
- an exhaust system coupled to an output of the second exhaust manifold and configured to transmit exhaust gases from the second manifold to an output of the turbocharger system, the exhaust system including a first heat exchanger coupled to receive exhaust gases from the second exhaust manifold and configured to transfer heat from gases entering the first heat exchanger to a working fluid, wherein the working fluid is methanol;
- a second turbine having an input coupled to the first heat exchanger and configured to expand the working fluid heated by the first heat exchanger, the second turbine coupled to the first turbine via a drive shaft;
- and
- a charge air compressor coupled to the drive shaft, the compressor having an output in fluid communication with an intake port of the engine, and the compressor configured to compress charge air for the engine and deliver charge air to the engine via the intake port.
Dependencies are inferred from the claim text.