Phase change heat engine
AssigneeThe United States of America as represented by the Administrator of the United States Environmental Protection Agency
InventorCharles L. Gray, Jr.
Life of this patent
Estimating the term…
Abstract
An automotive power plant includes an internal combustion engine and a heat exchanger for vaporizing fuel to the internal combustion engine utilizing heat from the combustion exhaust gas. The vaporized fuel may be fed to a combustion cylinder containing the compressed gas produced by a compression stroke. Alternatively, the vaporized gas may be fed to a dedicated expander for extracting work therefrom and then fed to the internal combustion engine.
Claims13
A power plant comprising:
- a combustion engine including at least one combustion cylinder and piston reciprocally mounted therein, a fuel inlet for introducing fuel to said one combustion cylinder, an air inlet, separate from said fuel inlet, for introduction of ambient air into said one combustion cylinder, the air being compressed within said one combustion cylinder prior to feeding fuel into said one combustion cylinder, and an exhaust outlet for release of an exhaust gas from said one combustion cylinder;
- a fuel tank for holding a liquid fuel;
- a heat exchanger for vaporization of fuel from said fuel tank and for superheating the fuel vapor by indirect heat exchange with the exhaust gas, said heat exchanger being connected to said fuel inlet for feeding the superheated fuel vapor into said one combustion cylinder through said fuel inlet;
- and
- valve means for feeding the vaporized and superheated fuel to said one combustion cylinder, with said piston near top dead center and containing the compressed air, said fuel undergoing combustion therein to form the exhaust gas.
A power plant comprising:
- a combustion engine including at least one combustion cylinder and piston reciprocably mounted therein, a fuel inlet for introducing fuel to said one combustion cylinder and an exhaust outlet for release of an exhaust gas from said one combustion cylinder;
- a fuel tank for holding a liquid fuel;
- a heat exchanger for vaporization of fuel from said fuel tank by indirect heat exchange with the exhaust gas;
- fuel feed means for feeding the vaporized fuel to said one combustion cylinder for combustion therein, forming the exhaust gas;
- and
- an expander for receiving vaporized fuel from said heat exchanger at a first pressure, for extracting work from the vaporized fuel, for exhausting the vaporized fuel at a second pressure lower than said first pressure, said expander including an expander cylinder and expander piston reciprocally mounted in said expander cylinder, said expander being located in a fuel line conveying vaporized fuel from said heat exchanger to said one combustion cylinder.
A method of operating a combustion engine including at least one combustion cylinder and a piston reciprocally mounted therein, the combustion cylinder having an air inlet, a fuel inlet separate from said air inlet, and an exhaust outlet, said method comprising:
- feeding air into the one combustion cylinder through the air inlet;
- compressing the air within the one combustion cylinder;
- feeding a liquid fuel to a heat exchanger for indirect heat exchange with the exhaust gas from the exhaust outlet to vaporize the liquid fuel;
- superheating the vaporized fuel within the heat exchanger;
- and
- feeding the superheated fuel vapor through the fuel inlet into the compressed air within the one combustion cylinder with the piston near top dead center, for combustion of the fuel in the one combustion cylinder and generation of power.
A method of operating a combustion engine including at least one combustion cylinder and a piston reciprocably mounted therein, the combustion cylinder having a fuel inlet and an exhaust outlet, said method comprising:
- feeding a liquid fuel to a heat exchanger for indirect heat exchange with exhaust gas from the exhaust outlet to vaporize the liquid fuel;
- superheating the vaporized fuel within the heat exchanger;
- feeding the superheated fuel vapor to an expander for expansion of the superheated fuel vapor therein thereby generating power;
- and
- feeding the expanded fuel vapor to the fuel inlet for combustion in the one combustion cylinder and generation of additional power.
Dependencies are inferred from the claim text.