Fuel agnostic compression ignition engine
Some embodiments described herein relate to a method of operating a compression ignition engine. The method of operating the compression ignition engine includes opening an intake valve to draw a volume of air into a combustion chamber, closing an intake valve, and moving a piston from a bottom-dead-center (BDC) position to a top-dead-center (TDC) position in the combustion chamber at a compression ratio of at least about 15:1. The method further includes injecting a volume of fuel into the combustion chamber at an engine crank angle between about 330 degrees and about 365 degrees during a first time period. The fuel has a cetane number less than about 40. The method further includes combusting substantially all of the volume of fuel. In some embodiments, a delay between injecting the volume of fuel into the combustion chamber and initiation of combustion is less than about 2 ms.
1 . A compression ignition engine, comprising:
an engine cylinder, the engine cylinder defining a combustion chamber having a compression ratio of at least about 15:1;
a fuel supply configured to supply a fuel to the combustion chamber, the fuel having a cetane number of less than about 40; and
a thermal management system configured to heat a volume of air to a temperature between about 80° C. and about 150° C. upon entering the combustion chamber, such that a delay between initiation of injection of a volume of fuel into the combustion chamber and ignition of the volume of fuel is no more than about 1 ms when no more than about 50% of the volume of the fuel is pre-mixed with the volume of air upon initiation of combustion.
2 . The compression ignition engine of claim 1 , wherein the combustion chamber includes a single vessel in which ignition and combustion of the volume of the fuel occur.
3 . The compression ignition engine of claim 1 , wherein the thermal management system includes at least one of a turbocharger or a supercharger.
4 . The compression ignition engine of claim 3 , wherein the thermal management system includes at least one of a recirculation port, an exhaust gas recirculation (EGR) cooler, a grid heater, a flame stabilizer, a catalytic burner, a spark plug, a glow plug, a hot air jet, or a plasma igniter.
5 . The compression ignition engine of claim 1 , wherein the fuel has a cetane number of less than about 20.
6 . The compression ignition engine of claim 1 , wherein the combustion chamber has a compression ratio between about 15:1 and about 25:1.
7 . The compression ignition engine of claim 1 , wherein the volume of the fuel includes less than about 3 wt % of additives that affect cetane number.
8 . The compression ignition engine of claim 1 , wherein the fuel includes at least one of naphtha, gasoline, alcohol, butanol, propanol, ethanol, methanol, gaseous hydrocarbons, natural gas, methane, ethane, propane, butane, hexane, alternative fuels, hydrogen, ammonia, syngas, or CO.
9 . The compression ignition engine of claim 1 , further comprising;
a fuel injector configured to inject the volume of fuel into the combustion chamber at a pressure of at least about 800 bar absolute.
10 . The compression ignition engine of claim 1 , wherein the thermal management system is configured to limit a delay between initiation of injection of the volume of fuel into the combustion chamber and ignition of the volume of fuel to no more than about 2 ms when no more than about 20% of the volume of the fuel is pre-mixed with air upon initiation of combustion.
11 . A compression ignition engine, comprising:
an engine cylinder, the engine cylinder defining a combustion chamber having a compression ratio of at least about 15:1;
a fuel supply configured to supply a fuel to the combustion chamber, the fuel having a cetane number of less than about 40 and an octane number of at least 95, the fuel including less than about 500 ppm by weight of additives that affect cetane number; and
a thermal management system configured to limit a delay between initiation of injection of a volume of fuel into the combustion chamber and ignition of the volume of fuel to no more than about 2 ms when at least about 25% of the energy generated from combusting the volume of the fuel is generated while the volume of fuel is injected into the combustion chamber.
12 . The compression ignition engine of claim 11 , wherein the combustion chamber includes a single vessel in which ignition and combustion of the volume of the fuel occur.
13 . The compression ignition engine of claim 11 , wherein the thermal management system includes at least one of a supercharger or a turbocharger.
14 . The compression ignition engine of claim 13 , wherein the thermal management system includes at least one of a recirculation port, an exhaust gas recirculation (EGR) cooler, a grid heater, a flame stabilizer, a catalytic burner, a spark plug, a glow plug, a hot air jet, or a plasma igniter.
15 . The compression ignition engine of claim 11 , wherein the fuel has a cetane number of less than about 20.
16 . The compression ignition engine of claim 15 , wherein the fuel has a cetane number of less than about 10.
17 . The compression ignition engine of claim 11 , wherein the combustion chamber has a compression ratio between about 15:1 and about 25:1.
18 . The compression ignition engine of claim 11 , wherein the volume of the fuel includes less than about 3 wt % of additives that affect cetane number.
19 . The compression ignition engine of claim 11 , wherein the fuel includes at least one of naphtha, gasoline, alcohol, butanol, propanol, ethanol, methanol, gaseous hydrocarbons, natural gas, methane, ethane, propane, butane, hexane, alternative fuels, hydrogen, ammonia, syngas, or CO.
20 . The compression ignition engine of claim 11 , wherein the thermal management system is configured to limit a delay between initiation of injection of the volume of fuel into the combustion chamber and ignition of the volume of fuel to no more than about 2 ms when no more than about 20% of the volume of the fuel is pre-mixed with air upon initiation of combustion.
21 . The method of claim 11 , wherein the combustion chamber includes points with local equivalence ratios of at least about 2.
22 . A compression ignition engine, comprising:
an engine cylinder, the engine cylinder defining a combustion chamber having a compression ratio of at least about 15:1;
a fuel supply configured to supply a fuel to the combustion chamber, the fuel having a cetane number of less than about 40 and an octane number of at least 95; and
a thermal management system configured to modify a temperature of intake air to limit a delay between initiation of injection of a volume of fuel into the combustion chamber and ignition of the volume of fuel to no more than about 2 ms when no more than about 50% of the volume of the fuel is pre-mixed with air upon initiation of combustion, and at least about 25% of the energy generated from combusting the volume of the fuel is generated while the volume of fuel is injected into the combustion chamber.
23 . The compression ignition engine of claim 22 , wherein the combustion chamber includes a single vessel in which ignition and combustion of the volume of the fuel occur.
24 . The compression ignition engine of claim 22 , wherein the thermal management system includes at least one of a recirculation port, an exhaust gas recirculation (EGR) cooler, a grid heater, a flame stabilizer, a catalytic burner, a spark plug, a glow plug, a hot air jet, or a plasma igniter.
25 . The compression ignition engine of claim 22 , wherein the fuel has a cetane number of less than about 20.
26 . The compression ignition engine of claim 22 , wherein the combustion chamber has a compression ratio between about 15:1 and about 25:1.
27 . The compression ignition engine of claim 22 , wherein the volume of the fuel includes less than about 3 wt % of additives that affect cetane number.
28 . The compression ignition engine of claim 22 , wherein the fuel includes at least one of naphtha, gasoline, alcohol, butanol, propanol, ethanol, methanol, gaseous hydrocarbons, natural gas, methane, ethane, propane, butane, hexane, alternative fuels, hydrogen, ammonia, syngas, or CO.
29 . The compression ignition engine of claim 22 , wherein the thermal management system is configured to limit a delay between initiation of injection of the volume of fuel into the combustion chamber and ignition of the volume of fuel to no more than about 2 ms when no more than about 20% of the volume of the fuel is pre-mixed with air upon initiation of combustion.
30 . The compression ignition engine of claim 22 , wherein the thermal management system includes at least one of a supercharger or a turbocharger.