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US 7,793,638 B2Granted
Low emission high performance engines, multiple cylinder engines and operating methods
AssigneeSturman Digital Systems, LLC
InventorOded Eddie Sturman
Life of this patent
Estimating the term…
Abstract
Low emission high performance engines, multiple cylinder engines and operating methods based on compression ignition of a combustion chamber charge already containing at least some fuel and air. Air is injected into the combustion chamber after top dead center is reached to maintain combustion until all fuel is consumed. Various modes of operation are disclosed.
Claims61
A method of operating a piston engine comprising, for at least one cylinder:
- controlling at least one engine valve so that a fuel in the cylinder will be ignited by compression ignition when the piston reaches or is near top dead center during a compression stroke;
- injecting fuel into the engine cylinder during the compression stroke;
- and,
- injecting air into the cylinder after ignition and during combustion in an immediately following power stroke.
1 more element
A method of operating a piston engine comprising, for at least one cylinder:
- controlling at least one exhaust valve to trap exhaust gases in the cylinder for compression during the compression stroke so that a fuel in the cylinder will he ignited by compression ignition when the piston reaches or is near top dead center during a compression stroke;
- injecting fuel into the engine cylinder during the compression stroke;
- injecting air into the cylinder during the compression stroke in an amount limited to limit the combustion temperatures on ignition to below the temperatures for formation of NOx;
- injecting air into the cylinder after ignition and during combustion in an immediately following power stroke.
1 more element
A method of operating a piston engine comprising, for at least one cylinder:
- controlling at one engine valve so that a fuel in the cylinder will be ignited by compression ignition when the piston reaches or is near top dead center during a compression stroke;
- injecting fuel into the engine cylinder during the compression stroke;
- and,
- injecting air into the cylinder after ignition and during combustion in an immediately following power stroke;
- wherein the fuel injected into the cylinder during the compression stroke comprises all the fuel that will be injected during the compression stroke and the following power stroke, the temperature reached after ignition being controllably limited by limiting the amount of oxygen in the cylinder on initial ignition to limit the combustion temperatures on ignition to below the temperatures for formation of NOx.
2 more elements
A method of operating a piston engine comprising, for at least one cylinder in a camless engine;
- controlling at least one engine valve so that a fuel in the cylinder will be ignited by compression ignition when the piston reaches or is near top dead center during a compression stroke;
- injecting fuel into the engine cylinder during the compression stroke;
- and,
- injecting air into the cylinder after ignition and during combustion in an immediately following power stroke.
1 more element
A method of operating a piston engine comprising, for at least one cylinder:
- controlling at least one engine valve so that a fuel in the cylinder will be ignited by compression ignition when the piston reaches or is near top dead center during a compression stroke;
- injecting fuel into the engine cylinder during the compression stroke;
- and,
- sensing cylinder pressure as an indication of ignition;
- injecting air into the cylinder after ignition and during combustion in an immediately following power stroke.
2 more elements
A method of operating a piston engine comprising, in a camless engine:
- at or near the end of a power stroke, opening and then closing the exhaust valve of a combustion cylinder to trap a predetermined amount of exhaust gas in the combustion cylinder;
- injecting fuel into the combustion chamber during the following compression stroke soon after the exhaust valve is closed;
- injecting air into the combustion cylinder as the piston approaches top dead center and before compression ignition;
- the amount of exhaust gas trapped in the combustion cylinder and the amount of air injected as the piston approaches top dead center being controlled to obtain compression ignition at or near top dead center without reaching NOx formation temperatures in the combustion cylinder;
- and,
- injecting air into the combustion cylinder after ignition and after the piston has passed top dead center to sustain combustion without reaching NOx formation temperatures and without injection of more fuel.
3 more elements
A method of operating a piston engine comprising:
- at or near the end of a power stroke, opening and then closing the exhaust valve of a combustion cylinder to trap a predetermined amount of exhaust gas in the combustion cylinder;
- injecting fuel into the combustion chamber during the following compression stroke soon after the exhaust valve is closed;
- injecting air into the combustion cylinder after ignition and after the piston has passed top dead center to sustain combustion also without reaching NOx formation temperatures during the power stroke and without injecting more fuel;
- and,
- the amount of exhaust gas trapped in the combustion cylinder and the amount of air injected into the combustion cylinder after ignition and after the piston has passed top dead center being in excess of the stoichiometric ratio by a controlled amount to provide residual oxygen in the trapped exhaust gas to obtain compression ignition at or near top dead center of the next compression stroke, also without reaching NOx formation temperatures in the combustion cylinder.
2 more elements
A method of operating a piston engine comprising:
- at or near the end of a power stroke, opening and then closing the exhaust valve of a combustion cylinder to trap a predetermined amount of exhaust gas in the combustion cylinder;
- injecting fuel into the combustion chamber during the following compression stroke soon after the exhaust valve is closed, the amount of fuel injected being the total amount of fuel to be injected during the compression stroke and the following power stroke;
- injecting air into the combustion cylinder as the piston approaches top dead center and before compression ignition;
- the amount of exhaust gas trapped in the combustion cylinder and the amount of air injected as the piston approaches top dead center being controlled to obtain compression ignition at or near top dead center without reaching NOx formation temperatures in the combustion cylinder;
- and,
- injecting air into the combustion cylinder after ignition and after the piston has passed top dead center to sustain combustion without reaching NOx formation temperatures.
3 more elements
A method of operating a piston engine comprising, in a camless engine:
- at or near the end of a power stroke, opening and then closing the exhaust valve of a combustion cylinder to trap a predetermined amount of exhaust gas in the combustion cylinder;
- injecting fuel into the combustion chamber during the following compression stroke soon after the exhaust valve is closed;
- injecting air into the combustion cylinder before compression ignition;
- the amount of exhaust gas trapped in the combustion cylinder and the amount of air injected as the piston approaches top dead center being controlled to obtain compression ignition at or near top dead center without reaching NOx formation temperatures in the combustion cylinder;
- and,
- without injecting additional fuel into the combustion chamber after the piston reaches top dead center, injecting air into the combustion cylinder after ignition and after the piston has passed top dead center to sustain combustion without reaching NOx formation temperatures.
3 more elements
A method of operating a multiple cylinder piston engine comprising:
- for at least a first cylinder of a camless engine;
- operating the first cylinder as an air compressor and controlling the quantity of air compressed and the pressure of the compression by control of at least one intake valve of the first cylinder;
- for at least a second cylinder of a camless engine, the second cylinder having at least a compression stroke and an immediately following power stroke;
- controlling at least one engine valve for the second cylinder so that a fuel in the cylinder will be ignited by compression ignition when the piston reaches or is near top dead center of a compression stroke;
- injecting fuel into the second cylinder during the compression stroke;
- and,
- injecting air compressed by the first cylinder into the second cylinder after ignition and during combustion in the immediately following power stroke.
4 more elements
A method of operating a piston engine comprising, for at least one cylinder:
- a) controlling at least one engine valve so that a fuel in the cylinder will be ignited by compression ignition when the piston reaches or is near top dead center of a compression stroke;
- b) injecting fuel and not air into the engine cylinder during the compression stroke before ignition;
- c) injecting air and not fuel into the cylinder during combustion in the first power stroke after the ignition of b), the amount of air injected being controlled to provide a controlled amount of air in excess of the air required for combustion of the fuel injected during the compression stroke of b), the amount of air in excess of the air required for combustion of the fuel injected during the compression stroke being controlled so that the temperature reached in ignition when the piston reaches or is near top dead center of the next compression stroke is below the temperatures at which NOx is formed, the rate and timing of the air injection being controlled to also maintain combustion temperatures below combustion temperatures at which NOx is formed;
- and,
- d) repeating a) through c).
2 more elements
A method of operating a piston engine comprising, for at least one cylinder of a camless engine:
- a) controlling at least one engine exhaust valve so that a fuel in the cylinder will be ignited by compression ignition when the piston reaches or is near top dead center of a compression stroke;
- b) injecting fuel and not air into the engine cylinder during the compression stroke before ignition;
- and,
- c) injecting air and not fuel into the cylinder during combustion in the first power stroke after the ignition of b), the amount of air injected being controlled to provide a controlled amount of air in excess of the air required for combustion of the fuel injected during the compression stroke of b), the amount of air in excess of the air required for combustion of the fuel injected during the compression stroke being controlled so that the temperature reached in ignition when the piston reaches or is near top dead center of the next compression stroke is below the temperatures at which NOx is formed, the rate and timing of the air injection being controlled to also maintain combustion temperatures below combustion temperatures at which NOx is formed;
- d) the amount of air injected in c) being controlled to provide a controlled amount of air in excess of the air required for combustion of the fuel injected during the compression stroke of b), together with the control of the at least one engine exhaust valve of a), to trap part of the exhaust gas to provide the air for the ignition of a);
- e) repeating a) through d).
3 more elements
Dependencies are inferred from the claim text.