WO2015004668A1

WO2015004668A1 - Hcci engine

Info

Publication number: WO2015004668A1
Application number: PCT/IL2014/050624
Authority: WO
Inventors: Leonid Tartakovsky; Amos KOHLSTADT; Mark Veinblat; Michael Shapiro; Arnon PORAN
Original assignee: Technion Research And Development Foundation Ltd.
Priority date: 2013-07-11
Filing date: 2014-07-10
Publication date: 2015-01-15
Also published as: IL227445A0

Abstract

An ignition and combustion control method for controlling ignition and combustion within an HCCI engine includes varying a fuel composition of a reformed fuel product for fueling the HCCI engine in response to changing loads or speeds of the HCCI engine. The fuel composition is varied by varying a water/fuel ratio of a mixture of water and fuel that is introduced into a fuel reformer to produce the reformed fuel product, and by controlling a temperature of a reaction within the fuel reformer. The HCCI engine is fueled with the fuel product.

Description

HCCI ENGINE

FIELD OF THE INVENTION

[0001] The present invention relates to homogenous charge compression ignition (HCCI) engines.

BACKGROUND OF THE INVENTION

[0002] Efforts are being made to increase the efficiency of combustion engines. For example, exhaust gases which can represent up to a 35 percent inefficiency, or greater, in internal combustion engines can often be recycled. An efficient combustion engine may combust a mixture of fuel by combining the fuel and some exhaust gases from the previous cycle in the cylinder under particular temperature and density conditions.

[0003] Homogenous charge compression ignition (HCCI) engines attempt to combine positive aspects of both a gasoline and a diesel engine into a cheaper to operate, more efficient engine.

[0004] In a HCCI engine, rather than relying on a spark plug to combust the fuel within a cylinder to drive the pistons, the conditions within the cylinder are designed to allow the fuel mixture to auto-combust. This auto-combustion may occur over several spatial points allowing the air-fuel mixture to burn nearly simultaneously and more cleanly, reducing noxious output.

[0005] An HCCI engine, unlike diesel and gas engines, may operate without a well- defined combustion initiator. Instead HCCI engines my control the compression ratio, inducted gas pressure, the air-fuel mix ratio, the amount and/or quantity of retained exhaust gases from the previous cycle and/or inducted gas temperature.

[0006] In the standard use of a HCCI engine, the following methods might be employed to promote combustion without the use of a spark, including, using a high compression ratio, retaining hot exhaust gases or preheating the induction gases. To prevent damage to the engine given uncertainties regarding the timing and nature of the explosions of fuel within the cylinders, a lean fuel mixture is typically used.

[0007] In some HCCI engines, there may be instances where the engine nevertheless has decreases in efficiency and higher harmful emissions. Some HCCI engines require the use of two fuel tanks and/or complimentary fuel systems, and may involve the use of complicated fuel filling logistics.

SUMMARY OF THE INVENTION

[0008] There is thus provided, in accordance with some embodiments of the present invention, An ignition and combustion control method for controlling ignition and combustion within an HCCI engine, the method including: varying a fuel composition of a reformed fuel product for fueling the HCCI engine in response to changing loads or speeds of the HCCI engine by varying a water/fuel ratio of a mixture of water and fuel that is introduced into a fuel reformer to produce the reformed fuel product, and controlling a temperature of a reaction within the fuel reformer; and fueling the HCCI engine with the fuel product.

[0009] Furthermore, in accordance with some embodiments of the present invention, the method includes using exhaust gases from the HCCI engine for inputting into the fuel reformer.

[0010] Furthermore, in accordance with some embodiments of the present invention, the exhaust gases are used to supply heat to the reaction within the fuel reformer to control the temperature of the reaction.

[0011] Furthermore, in accordance with some embodiments of the present invention, the exhaust gases are used to provide water to the fuel reformer.

[0012] Furthermore, in accordance with some embodiments of the present invention, the method includes using an electric propulsion system to power a vehicle at predetermined times.

[0013] Furthermore, in accordance with some embodiments of the present invention, fueling the HCCI engine includes injecting the fuel product into the HCCI engine.

[0014] Furthermore, in accordance with some embodiments of the present invention, the method includes controlling a pump to apply pressure to the mixture while in liquid form to pressurize the fuel product for injection into the HCCI engine.

[0015] Furthermore, in accordance with some embodiments of the present invention, the method includes vaporizing the mixture for input into the reformer. [0016] There is further provided, in accordance with some embodiments of the present invention, a propulsion system including: an HCCI internal combustion engine; a recovery system to recover exhaust gases from the HCCI engine; a reformer configured to use the recovered exhaust gases to perform a reforming process on a mixture of a fuel and water to produce a reformed fuel product for fueling the HCCI engine; and a control unit to vary, in response to changing loads or speeds of the HCCI engine, a composition of the reformed fuel product by varying a water/fuel ratio of a mixture of water and fuel that is introduced into the fuel reformer and by controlling a temperature of a reaction within the fuel reformer.

[0017] Furthermore, in accordance with some embodiments of the present invention, the propulsion system includes an electric motor.

[0018] Furthermore, in accordance with some embodiments of the present invention, the recovery system is configured to recover heat or water vapor from the exhaust gases.

[0019] Furthermore, in accordance with some embodiments of the present invention, the recovery system is configured to dissipate heat from the exhaust gases using a radiator.

[0020] Furthermore, in accordance with some embodiments of the present invention, the propulsion system includes one or a plurality of condensers to condense water vapor from exhaust gases into recovered water.

[0021] Furthermore, in accordance with some embodiments of the present invention, the control unit is configured to vary the fuel composition in real time in response to the changing loads or speeds of the HCCI engine .

[0022] Furthermore, in accordance with some embodiments of the present invention, the system includes an injector for injecting the fuel product into the HCCI engine.

[0023] Furthermore, in accordance with some embodiments of the present invention, the system includes a pump for applying a pressure to the mixture in a liquid state so as to control a pressure of injection of the fuel product into the HCCI engine.

[0024] Furthermore, in accordance with some embodiments of the present invention, the system includes an evaporator for vaporizing the mixture for introduction into the reformer. [0025] Furthermore, in accordance with some embodiments of the present invention, the evaporator is configured to use heat from the exhaust gases to vaporize the mixture.

BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to better understand the present invention, and appreciate its practical applications, the following Figures are provided and referenced hereafter. It should be noted that the Figures are given as examples only and in no way limit the scope of the invention. Like components are denoted by like reference numerals.

[0027] Fig. 1 A is a schematic illustration of a HCCI internal combustion engine fueled, at least in part, by fuel reforming products;

[0028] Fig. IB is a schematic illustration of a hybrid propulsion system with HCCI internal combustion engine;

[0029] Fig. 2 is a schematic illustration of a HCCI internal combustion engine, according to an embodiment of the invention;

[0030] Fig. 3 is a schematic illustration of a HCCI internal combustion engine, fueled partially via fuel reforming products, according to an embodiment of the invention;

[0031] Fig. 4 is schematic illustration of the preheating of fuel reforming system products by exhaust heat of a HCCI internal combustion engine within a hybrid propulsion system, according to an embodiment of the invention;

[0032] Fig. 5 is schematic illustration of the preheating of fuel reforming system products by a radiator of a HCCI internal combustion engine within a hybrid propulsion system, according to an embodiment of the invention;

[0033] Fig. 6 is a schematic illustration of a system for water recovery by a HCCI internal combustion engine within a hybrid propulsion system;

[0034] Fig. 7 is a schematic illustration of an Reformer-ICE management system within a hybrid propulsion system, according to an embodiment of the invention;

[0035] Fig. 8 is a schematic illustration of an ignition control method for controlling ignition within an HCCI engine, according to an embodiment of the invention; and

[0036] Fig. 9 is a schematic illustration of a HCCI internal combustion engine that operates with pressurized fuel injection, in accordance with an embodiment of the invention. [0037] It will be appreciated that, for simplicity and clarity of illustration, elements shown in the figures have not necessarily been drawn to scale. For example, the dimensions of some of the elements may be exaggerated relative to other elements for clarity. Further, where considered appropriate, reference numerals may be repeated among the figures to indicate corresponding or analogous elements.

DETAILED DESCRIPTION OF THE INVENTION

[0038] In the following detailed description, numerous specific details are set forth in order to provide a thorough understanding of the methods and apparatus. However, it will be understood by those skilled in the art that the present methods and apparatus may be practiced without these specific details. In other instances, well-known methods, procedures, and components have not been described in detail so as not to obscure the present methods and apparatus.

[0039] Although the examples disclosed and discussed herein are not limited in this regard, the terms "plurality" and "a plurality" as used herein may include, for example, "multiple" or "two or more". The terms "plurality" or "a plurality" may be used throughout the specification to describe two or more components, devices, elements, units, parameters, or the like. Unless explicitly stated, the method examples described herein are not constrained to a particular order or sequence. Additionally, some of the described method examples or elements thereof can occur or be performed at the same point in time.

[0040] Unless specifically stated otherwise, as apparent from the following discussions, it is appreciated that throughout the specification, discussions utilizing terms such as "adding", "associating," "selecting," "evaluating," "processing," "computing," "calculating," "determining," "designating," "allocating," or the like, refer to the actions and/or processes of a computer, computer processor or computing system, or similar electronic computing device, that manipulate, execute and/or transform data represented as physical, such as electronic, quantities within the computing system's registers and/or memories into other data similarly represented as physical quantities within the computing system's memories, registers or other such information storage, transmission or display devices. [0041] An aspect of the present invention includes an ignition control method for controlling ignition within an HCCI engine, the method including varying a fuel composition of a fuel product or reforming product for fueling the HCCI engine in response to changing loads and number of revolutions of the HCCI engine, wherein the varying composition of the fuel product is obtained by controlling a water/fuel ratio of the primary fuel and by controlling a temperature of a reaction within the fuel reformer and fueling the HCCI engine with the fuel product. The primary fuel is a fuel-water mixture. For example, the fuel component of the primary fuel may include methanol or another alcohol.

[0042] Use of a water-fuel mixture may enable use of a single reformer, rather than two, as would be required by other systems.

[0043] An aspect of the present invention includes an ignition and combustion control method for controlling ignition and combustion duration within an HCCI engine. Some aspects of the invention relates to a method for controlling ignition and combustion duration of a hybrid propulsion system that includes a homogenous charge compression ignition (HCCI) internal combustion engine (ICE).

[0044] An internal combustion engine in an HCCI engine system typically produces hot exhaust gases. The hot exhaust gases usually contain a mixture of water and other fluids. According to embodiments of the present invention, the heat from the exhaust gases can be extracted and employed for a reforming process and the water from exhaust gases can be extracted and employed as an input in the reforming process.

[0045] According to embodiments of the present invention, outputs from the reforming process are modified, for example by varying the reforming temperature, composition of inputs, e.g., a water/primary fuel ratio for use in the HCCI ICE.

[0046] HCCI engines typically suffer from an inability to quickly adapt to varying workloads and speeds. HCCI engines also typically suffer from cold- starting. According to some embodiments of the present invention, an electric motor within a hybrid propulsion system with an HCCI ICE may be employed and/or configured to operate at predetermined times. The predetermined times may include circumstances where the HCCI ICE is not optimized for operation, for example, for cold starts.

[0047] According to embodiments of the present invention, HCCI auto-ignition temperatures of the fuel mixture entering the HCCI engine, and the burning velocity of that mixture may be designed to overcome limitations with HCCI engines, for example, as described above.

[0048] According to embodiments of the present invention, outputs from the reforming process are used as inputs in the internal combustion engine.

[0049] A further aspect of the present invention is a hybrid propulsion system that includes an HCCI internal combustion engine (ICE). Most internal combustion engines employ a radiator. According to some embodiments of the present invention, the radiator is configured to employ exhaust heat from the ICE to preheat inputs for a reforming process. Outputs from the reforming process are used as inputs in the internal combustion engine.

[0050] In some embodiments of the invention, an HCCI engine may have advantages including reducing emissions from internal combustion engines and to lessen the carbon footprint of vehicles in general. One method for overcoming the limitations of HCCI engines is the use of alternative fuels, such as biofuels. First generation biofuels currently on the market are, however, inefficient and may be worse for the environment given impacts on food crops and the like and the energy needed for their creation.

[0051] Increasing vehicle efficiency may present an alternative cost effective and easily implemented solution and a viable alternative to biofuels. One way to improve efficiencies in internal combustion engines is through the recovery of wasted heat in exhaust. An additional option is the use of low temperature combustion of fuels.

[0052] The recovered waste heat from the exhaust may, in some embodiments be used for turbo-charging, turbo-compounding, cabin air heating, Rankine cycle utilization, thermoelectric effect utilization and fhermo chemical recuperation (TCR).

[0053] Homogenous charge compression ignition engines attempt to combine positive aspects of both a gasoline and a diesel engine into a cheaper to operate, more efficient and less polluting engines. HCCI engines may also provide for lower temperature combustion in comparison to standard internal combustion engines.

[0054] HCCI engines may have suffered from inabilities to effectively recirculate exhaust. Many HCCIs require two fuel tanks with complicated components and redundancies to make sure that the system works properly. [0055] According to some embodiments of the present invention, waste exhaust from an HCCI engine can be recycled back into usable energy for propelling a vehicle via a process known as alcohol steam reforming or fuel reforming (hereinafter referred to as SR).

[0056] A catalytic reforming process is a chemical process, in some examples used within car and other vehicle engines, and in some examples used in chemical processing plants, to convert an intermediate hydrocarbon liquid stream, and or other hydrocarbon derivates or other ingredients or byproducts from a fuel mix into reformates, e.g., higher octane products than the starting products. Reformates may include hydrocarbons with more complicated chemical structures than their precursors. Hydrogen is also typically a byproduct of reformation.

[0057] SR may not necessarily require the use of an alcohol and may be a component of hydrogen production or other derivatives of hydrocarbon fuels. In some examples, a reformer may be a device or reactor that is configured to allow for the reaction of fossil fuels and steam at high temperatures. Onboard reforming of fuels for use in fuel cells and engines may employ a separate tank of an alcohol or other starting ingredient. The alcohol or other starting ingredient can be reformed on board the vehicle to produce syngas. E.g., C¾ + H₂0 CO + 3 H₂.

[0058] Reforming can also be employed to convert sometimes otherwise waste gases into energy for use in an internal combustion or other type of engine. In some examples, non-methane hydrocarbons may be converted to synthesis gas (H₂ + CO) with addition of some other materials, as methane (CH₄), carbon dioxide (CO₂) and other to improve the quality of the fuel.

[0059] One approach to efficiently reform liquid fuels on a vehicle into syngas may be through thermo-chemical recuperation (herein referred to as TCR), wherein waste heat is utilized to drive endothermic reformation reactions to produce hydrogen-rich gaseous fuel product.

[0060] In some examples, TCR and SR may take place within a hybrid engine that has both an HCCI ICE, as well as an electrical motor to circumvent limitations of the HCCI engines. [0061] In some embodiments of the invention, an HCCI internal combustion engine is configured to combust fuel, typically a mixture of fossil fuel and an oxidizer, such as air. Fuel is combusted in a combustion chamber, for example in an engine cylinder. The rapid expansion of the combusted fuel causes a piston in a cylinder to move. The movement of the cylinder is a transformation of the chemical energy to a mechanical energy.

[0062] Fig. 1A is a schematic illustration of an HCCI internal combustion engine fueled, at least in part, by alcohol steam reformation (SR) products, according to an embodiment of the invention.

[0063] Propulsion system 10 includes engine 20. Engine 20 is an HCCI engine. In some embodiments of the invention, engine 20 may be a two-stroke, four-stroke, six- stroke or other type of engine.

[0064] Engine 20 may use a hydrocarbon fuel such as a fossil fuel. Engine 20 may use an ethanol based fuel. Engine 20, in some embodiments of the invention, may use an alternative fuel. In some embodiments of the invention, engine 20 may use a first, second, third, fourth or subsequent generation of biofuels. In some embodiments of the invention, engine 20 may be coupled directly or indirectly to components within a powertrain in a vehicle. In some embodiments of the invention, engine 20 may be coupled to other components of a vehicle.

[0065] As part of a cycle of engine 20, an exhaust product 30 may be created. Exhaust product 30 may be a flue gas. Depending on the hydrocarbon or otherwise makeup of the fuel in engine 20, exhaust product 30 may include nitrogen, sulfur dioxide, nitric acid vapor, water vapor, carbon dioxide, carbon monoxide, other hydrocarbons, nitrogen oxides, ozone, and particulate matter. Exhaust temperatures may be high and may be measured by a gauge. Typical exhaust gas temperatures may vary in a wide range from 200 to 1200°C depending on engine type and operation conditions.

[0066] In some embodiments of the invention, recovered exhaust products 30 from an engine, or a portion thereof, are directed to a reformer 40. Exhaust product 30 are, in some examples, directed in the direction indicated by arrow 35. Exhaust product may eventually be exited from system 10. [0067] Water vapor 70, e.g., recovered or recycled exhaust water vapor, e.g., from recovered exhaust gases, is also directed to a reformer from evaporator 60. Reformer 40 uses alcohol 50 or other primary fuel in the process of reformation.

[0068] Evaporator 60 uses liquid water 90 to create water vapor 70 for use in catalytic reformer 40. Alcohol 50 is also inputted into evaporator 60. Other sources of water vapor for catalytic reformer 40 may also be used in some embodiments of the invention. Exhaust products 100 from system 10 may be exhausted from the system at one or a plurality of instances and locations.

[0069] Reformer 40 using, in some embodiments of the invention, alcohol 50, and water vapor 70 and/or other inputs reforms the inputs through SR. SR products 110, or a portion thereof, are inputted back into engine 20.

[0070] In some embodiments of the invention, some outputs, as depicted by arrow 45, of reformer 40, e.g., fuel, may be burned prior to entering engine 20 to heat reformer 40 to increase the temperature of reactions within.

[0071] In some embodiments of the invention, parameters of the SR products 110 input into engine 20 such that the air/fuel mixture, ratio of inputs into reformer 40, temperature, density, and /or other characteristics of the SR products 110 may be modified to overcome limitations associated with HCCI engines. In some embodiments of the invention, a second, e.g., electric, engine may be used for starting a hybrid propulsion system having an HCCI ICE and an electric motor, to overcome concerns related to cold starts of HCCI engines, wherein, for example, the electric engine can be used to start the vehicle and operate the vehicle until such a time that the HCCI would be able to start without cold start concerns.

[0072] Fig. IB is a schematic illustration of a hybrid propulsion HCCI internal combustion engine.

[0073] HCCI ICE 130 works in conjunction with electric motor 140 in hybrid propulsion system 150.

[0074] Components of hybrid propulsion system 150, including interactions between HCCI ICE 130 and an electric propulsion system, e.g., an electric motor 140 and including interactions with other components within a vehicle, e.g., including components as described hereinabove and below may be controlled by a control unit 160, the control unit controlling among other processes, a process for controlling ignition and combustion within an HCCI engine.

[0075] Fig. 2 is a schematic illustration of an HCCI internal combustion engine, according to an embodiment of the invention.

[0076] In some embodiments of the invention, a vehicle, stationary power plant and/or other device coupled to an engine system 200 may be a series-type scheme.

[0077] In some embodiments of the invention, a series hybrid, power-split or other hybrid-type vehicle is driven at certain times by an electric motor 260. In some embodiments, the electric motor has no mechanical connection to the engine itself. It is coupled directly via a transmission to wheels 265 of a vehicle. An engine may be tuned for running a generator when the battery pack energy supply is not sufficient for power demands of the vehicle.

[0078] In some embodiments of the invention, a HCCI ICE 210 may drive a generator 220; the generator is coupled to an HCCI ICE 210. HCCI ICE 210 may be a component of a hybrid propulsion system, the hybrid propulsion system including an ICE and an electric motor. Hybrid systems can also be plug-in hybrids, full hybrids or mild hybrids. The electric motor on the hybrid propulsion system may be powered in addition to generator also by a fuel cell or other sources of electric power.

[0079] HCCI ICE 210 is fueled by reforming products from an alcohol reforming system 280. SR 280 products may be reformed such that the fuel mixture auto-ignition temperature, burning velocity, density, and/or other characteristics of the SR products inputted into HCCI ICE 210 are modified to overcome issues associated with HCCI engines. The hybrid propulsion system including electric motor 260 may be configured to overcome cold starts, in some examples.

[0080] A rechargeable battery 230 may provide energy for one or a plurality of components in engine system 200. Rechargeable battery 230 powers, in some examples, electric motor 260 in a hybrid propulsion system. Other and/or additional energy sources may provide the supplied energy for HCCI ICE 210.

[0081] Capacitor 235 may be a flywheel and is typically a component of a serial hybrid propulsion system. [0082] HCCI ICE 210 may run when engine system 200 is running or may run only part of the time that engine system 200 is running. An electric motor may run when HCCI ICE 210 is stopped, idle or concurrently with HCCI ICE 210. Other propulsion systems may be operating with or in lieu of electric motor 260

[0083] ICE 210, Battery 230, a motor unit 250, wheels 260, ICE 210 and/or other components of engine system 200 may be controlled by control unit 240. Control unit 240 may be in communication with sensors and/or other components of engine system 200.

[0084] In some embodiments, control unit 240 may calibrate reform products. Calibration of reform products may include modifying and/or varying the temperature of the reform products. Calibration of the reform products may include modifying the make-up of a fuel mixture, the fuel mixture fed into ICE 210, including for example the fuel/air ratio of the fuel mixture. The fuel mixture may contain varying amounts of fuel, air and other components, the varying amounts within the mixture may change depending on the needs of ICE 210. Needs of ICE 210 may depend on the load, speed and other variables of ICE 210.

[0085] ICE 210, coupled to an alcohol reforming system, may use liquid alcohol 270 and/or other inputs to create reformation products to be used within ICE 210.

[0086] In some embodiments of the invention, hybrid propulsion system may be other types of hybrid propulsion systems, including parallel hybrid propulsions systems where either the electric motor and/or the HCCI ICE may be coupled to wheels 265.

[0087] Fig. 3 is a schematic illustration of an HCCI internal combustion engine within hybrid propulsion system, fueled at least partially by alcohol reforming products, according to an embodiment of the invention.

[0088] In some embodiments of the invention, engine system 300 may be a system within a vehicle, configured to turn the wheels 310 of the vehicle via a final drive component 320.

[0089] The final drive component is coupled to a gear box 325. Gear box 325 is coupled to a ring gear 330, a carrier gear 340 and a sun gear 350. [0090] In some embodiments of the invention, ring gear 330 may be a ring with teeth. The ring may be made from carbon steel or other materials. Ring gear 330 may be fitted onto the periphery of a flywheel of an ICE for automotive applications.

[0091] Ring gear 330 may be drive by a smaller gear of a motor generator 360. Ring gear 330 may be configured to transfer torque from motor generator 360 to gear box 325. Sun gear 350, carrier gear 340 and ring gear 330 may be components of an automatic transmission. Sun gear 350 is coupled to starter alternator 365.

[0092] In a power-split scheme at low acceleration events when the power of engine 370, e.g., HCCI ICE exceeds a typical road load, excess engine power may be used to charge a battery 390 by using one or a plurality of motor-generators 360 in their generating mode. When the power of engine 370 matches the road load, but the engine has insufficient torque, the motor-generator acts as a motor to deliver additional power to wheels 310 by discharging the battery 390. In some power split systems, a negative split may be entered as a means to further lower its speed at given torque.

[0093] In some embodiments of the invention, the combustion of a gaseous mixture of hydrogen and carbon monoxide in an ICE 370 may provide for a lean burn engine operation and minimal pollutant emissions. ICE 370 may be a component of a hybrid propulsion drive system; the hybrid propulsion drive system may include an ICE and an electric motor.

[0094] ICE 370 may be coupled to a reforming system 380 (hereinafter SR 380). SR 380 may be configured to use inputs such as liquid fuel and water as reactants within SR 380. To maintain an endothermic reaction within SR 380, the liquid fuel and water may be heated and evaporated prior to introduction into SR 380.

[0095] In some embodiments of the invention, the liquid fuel may be ethanol. Ethanol may be kept at an ambient temperature of around 300 degrees Kelvin. In some embodiments of the invention, ethanol may be kept at a higher or lower ambient temperature.

[0096] In some embodiments of the invention, the ethanol for use in SR 380 may be heated to approximately 1 100 degrees Kelvin. In some embodiments of the invention, the ethanol may be heated to a higher or lower temperature.

[0097] SR 380 may cool the products of the reformation process via a heat exchanger. In some embodiments of the invention, heat from the reformation process in SR 380 may be released into the environment. In some embodiments of the invention, heat from the reformation process within SR 380 may be used to pre-heat and evaporate the inputs into the subsequent reformation process, e.g., to vaporize liquid water and/or alcohol inputs of SR 380 as described herein below.

[0098] SR 380 may have as one of the inputs into the reformation process, liquid alcohol 385.

[0099] Battery 390 of a hybrid system may be of any suited type and chemistry, e.g. Li- Ion, Li-Polymer or other.

[00100] Inverter 395 converts direct current from battery 390 into the alternate current coming to an electric component within the system, e.g., a motor.

[00101] Fig. 4 is schematic illustration of the preheating of incoming water and alcohol or other fuel by hot reforming products of a HCCI internal combustion engine within hybrid propulsion system.

[00102] Preheating of alcohol reforming system inputs, may limit concerns relating to cold starts of HCCI engines, as described, for example above. And, for example, by providing conditions such that the HCCI is started under warmer conditions.

[00103] A system 400 includes a fuel tank 410. Fuel from fuel tank 410, in some examples, a liquid water/fuel mixture, is transferred to a heat exchanger 420 as indicated by arrow 430.

[00104] Preheated and/or evaporated water and fuel mixture is passed out of heat exchanger 420 as indicated by arrow 435 and transferred to reformer 440. Reformer 440 may be, as described above, for example with regard to alcohol reforming systems described above.

[00105] In some embodiments of the invention, hot reformed products exit reformer 440 as indicated by arrow 450. In some embodiments of the invention, reformed products are cooled in heat exchanger 420.

[00106] In some embodiments of the invention, cooled reformed fuel mixture and water is transferred to engine intake 460, where it is used within an HCCI ICE. The HCCI ICE is, in some embodiments of the invention, part of a hybrid propulsion system, the hybrid propulsion system including an HCCI ICE and an electric motor. [00107] Fig. 5 is schematic illustration of the preheating of alcohol reforming system products by a radiator of a HCCI internal combustion engine within hybrid propulsion system, according to an embodiment of the invention.

[00108] In some embodiments of the invention, SR precursors may be preheated by a radiator 510 within a system 500. Radiator 510 may be a standard engine radiator configured to dissipate heat. The heat collected in radiator 510 from the engine coolant may be useful in preheating and vaporization of the reformer inputs.

[00109] Radiator 510 may be configured to be a heat exchanger to dissipate and/or transfer heat from a first medium to a second medium. Radiator 510 may be a convector, transferring heat through convention. In system 500, an engine 520, in some embodiments of the invention, an ICE may be configured to run as an HCCI engine as described, for example above. In some embodiments of the invention, engine 520 is configured to be coupled to be a component of a hybrid propulsion system, including, an electric motor, and/or other motor.

[00110] In some embodiments of the invention, water is supplied together with a liquid fuel from one or a plurality of tanks, e.g., tank 530. The fuel/water mixture may be pumped and/or other transferred to radiator 510. The pathway of the water/fuel mixture as indicated by arrow 540. Fuel water mixture may also include air.

[00111] The fuel/water mixture may be passed through radiator 510, where the fuel/water mixture may exit as a pre-heated fuel/water mixture. The preheated fuel/water mixture may be heated via exhaust from engine 520. In some embodiments of the invention, exhaust from engine 520 may be exited from engine 520 via an exhaust manifold 580 and may end up dissipating heat in radiator 510.

[00112] The pre-heated fuel/water mixture may be transferred through pipes and/or via other means within system 500 along pathway depicted by arrow 550 to a reformer 560. Pre-heated Fuel/water mixture via heat dissipated from radiator 510 may include precursors for reforming products resulting from the reforming process within reformer 560. Reformer 560 may produce reforming products from precursors. Reforming products may follow a pathway within system 500, the pathway depicted by arrow 570. Reforming products may be introduced into engine 520 via an intake manifold 590. [00113] Coolant cycles through radiator 510 with the help of an engine coolant pump 575. Coolant is pumped through an engine as depicted by arrows 515. The coolant heated within engine 520 dissipates heat in radiator 510. The cooler coolant is then recycled back to the engine, where it is loaded with heat energy from the engine to be dissipated.

[00114] Pre-heating SR precursors, inputs, and/or other chemicals that enter into reformer 560, according to embodiments of the invention may provide a substantial decrease (e.g., some 20-30%) in the energy required from the ICE exhaust gas stream to maintain the reforming process.

[00115] Fig. 6 is a schematic illustration of a system for water recovery by a

HCCI internal combustion engine within hybrid propulsion system, according to an embodiment of the invention.

[00116] In some embodiments of the invention, water available in the exhaust gases of an internal combustion engine may be sufficient for use in a water fuel mixture within an engine system and for use in a reformation process. In some embodiments of the invention, water recovered from exhaust gases may be sufficient to account for the entire or a portion of the need for water in the reforming process and for the operation of an engine. In some embodiments of the invention, water from exhausts gases is sufficient for use in the reformation process and a tank to hold water with an engine or coupled to an engine may act as a redundant water source.

[00117] In some embodiments of the invention, the engine may be an ICE configured to run as an HCCI-type engine. In some embodiments of the invention, the engine may be a component of a hybrid propulsion system, wherein a first engine is an HCCI ICE and a second engine is an electric motor. Engine system 610 may be a hybrid propulsion system.

[00118] A water recovery system 600 may be incorporated into an engine system

610.

[00119] Exhaust gases 620 may be collected from an engine, and/or from other sources within engine system 610. Exhaust gases may be channeled through via pipes or via other means into a high temperature heat exchanger 630. High temperature heat exchanger may extract heat 635 from exhaust gases 620. Heat 635 extracted from exhaust gases 620 may be employed in an ethanol reformer system or other reformer system 640 employed by engine system 610.

[00120] In some embodiments of the invention, heated exhaust gases may be passed via pipes or via other means through a low temperature heat exchanger 650. Low temperature heat exchanger 650 may extract heat 655.

[00121] Exhaust gases 620 passing through low temperature heat exchanger 650 may be passed via pipes or other means to a condenser 660. Recovered water 670 from condenser, originally from exhaust gases 620, and may originally be in the form of water vapor may be combined with additional water from other components of engine system 610, and or components coupled to engine system 610. Heat 665 may be recovered from condenser 660.

[00122] Additional water may include water condensate 680 from an air conditioner unit and/or system within a vehicle. Water 670 and additional water condensate 680 from the air conditioning system within the vehicle, or, in some examples from other air conditioning systems, or from other systems, the systems either within our outside of the vehicle may be combined with ethanol 690. Ethanol 690, water 670 and water condensate 680 may be mixed actively and/or passively within a water ethanol mixture tank 700. The control of the inputs into water/ethanol mixture tank, their concentrations, their temperature, and other features of the inputs may be controlled by a control unit 720. The resulting mix 730 may be transferred to an evaporator 710.

[00123] Mix 730 may be evaporated within evaporator 710. Heat 655 and 665 for the evaporation process may be derived from low temperature heat exchange 650, condenser 660 and/or other sources of heat. Mix 730, once evaporated by evaporator 710 may be introduced as a precursor into ethanol steam reformer 640. Other precursors may also be introduced.

[00124] Outputs of ethanol steam reformer may be inputs for use in an HCCI

ICE. Characteristics of the output relevant to the function of the HCCI ICE may be controlled, in some embodiments of the invention, by control unit 720. Other control units and other components such as valves, sensors and other devices may be used to control and/or change the characteristics of the output of ethanol steam reformer 640, such that the outputs are optimized for the current and/or future conditions facing an HCCI ICE. Control unit 720 may also control the relative exertions and the timing of the use of the HCCI ICE and an electronic engine with a hybrid propulsion system.

[00125] Control unit may control inputs and outputs of the reformer in real time or near real time to overcome concerns regarding engine loads in real time and/or near real time.

[00126] Fig. 7 is a schematic illustration of a Reformer-ICE management system within a hybrid propulsion system, according to an embodiment of the invention.

[00127] Reformer-ICE management system 800 may be configured to control the inputs 810 and outputs 820 of a number of processes within a hybrid propulsion system, providing for, in some examples, a wide range by variation of a water/fuel ratio and a wide variability in the reforming temperature. Changes in the reformation temperature and water/fuel ratios allow for changing auto-ignition point and burning velocity of the reformation products entering HCCI ICE.

[00128] Reformer-ICE management system 800 may be configured to control the inputs 810a and outputs 820a of a reformation process within reformer 870.

[00129] In some embodiments of the invention, inputs 810a may include heat, one or a plurality of fuels, and water. In some embodiments of the invention, outputs 820a may include fuel. Reformer-ICE management system 800 may be configured to control the inputs 810b and outputs 820b of a combustion process within ICE 880. In some embodiments of the invention, inputs 810b may include fuel. In some embodiments of the invention, outputs 820b may include exhaust.

[00130] Reformer-ICE management system 800 may include one or a plurality of pumps 830, sensors 840, valves 850 and/or other components. Pumps 830, sensors 840, valves 850 and/or other components may be controlled, manipulated and/or otherwise interacted with via one or a plurality of Reformer-ICE management system control units 860.

[00131] Reformer-ICE management system 800 may also include a configuration to control water recovery from exhaust gases of the ICE for use in the reforming process, the water recovery as described, for example, above.

[00132] Reformer-ICE management system 800 may be configured to facilitate a cold start of an ICE engine. In some embodiments of the invention, Reformer-ICE management system 800 may be configured to facilitate the colds start of an ICE hybrid propulsion system. In some embodiments of the invention, reformer-ICE management system 800 may be configured to facilitate cold starts by employing an electric motor 890

[00133] Reformer-ICE management system 800 may be configured, in some embodiments of the invention, to control and/or direct the preheating of liquid reactants for an ICE-hybrid propulsion system. In some embodiments of the invention, reformer- ICE management system 800 may be configured to control the preheating of liquid reactants for an ICE-hybrid propulsion system by using heat of an engine coolant or other heated fluids within a propulsion system.

[00134] Reformer-ICE management system 800 may, in some embodiments of the invention, control the HCCI combustion process by modifying the water-to-fuel ratio and the reforming temperature. In controlling the modifications of water to fuel ratios the burning velocity and auto-ignition temperature of fuel supplied to HCCI ICE can be controlled and, in some embodiments of the invention, the combustion phasing of the fuel mixture can be controlled as well.

[00135] In some embodiments of the invention, the use of a preheating mechanism by Reformer-ICE management system 800 may facilitate cold-starts of an HCCI ICE.

[00136] In some embodiments of the invention, the Reformer-ICE management system 800 may facilitate the use of renewable fuels in an HCCI ICE.

[00137] In some embodiments of the invention, the Reformer-ICE management system 800 may facilitate the onboard storage of fuels, in some examples providing for the configuration of an HCCI ICE that does not require an additional fuel or water tank.

[00138] In some embodiments of the invention, the Reformer-ICE management system 800 may facilitate the use of hydrogen and carbon monoxide as fuels for an HCCI ICE without the need for liquid alcohol or carbon dioxide. In some examples, this may lessen the pollution from the emissions of the HCCI ICE. In some examples, the emissions of the HCCI ICE may be described as zero-impact emissions.

[00139] Reformer-ICE management system 800 may, in some embodiments of the invention, control inputs and outputs of the reformer in real time or near real time to overcome real time engine load concerns. Concerns may include the rapid changing of loads on the engine, and the ability of the HCCI engine to accommodate those load changes in sufficient amount of time. In some examples, reformer-ICE management system 800 could be employed to modify the fuel intake of the HCCI engine such that different fuel mixtures are provided to the HCCI engine in real time, depending on the load on the engine.

[00140] Fig. 8 is a schematic illustration of an ignition and combustion control method for controlling ignition and combustion within an HCCI engine, according to an embodiment of the invention.

[00141] Box 900 depicts a step in an ignition and combustion control method, within an ignition and combustion control system for controlling ignition and combustion within an HCCI engine. The method for ignition and combustion control includes varying a fuel composition of a fuel product for fueling the HCCI engine in response to changing loads of the HCCI engine, wherein the varying composition of the fuel product is obtained by controlling a water/fuel ratio of the primary fuel and by controlling a temperature of a reaction within the fuel reformer.

[00142] Box 910 depicts a step in the ignition and combustion control method for controlling ignition and combustion within an HCCI engine, the step including fueling the HCCI engine with the fuel product. Fueling the HCCI engine may include injecting the fuel product into the HCCI engine.

[00143] The high hydrogen content in the reformate increases the flame velocity to enable lean operation and a high combustion ratio (CR). However, backfire pre- ignition may occur when the reformate is introduced into the engine via fumigation, thus reducing the engine power. Mechanisms that could cause pre-ignition may include, for example, hot spots, residual flames in the piston crevices, oil contaminant, and residual energy in the spark plug. In addition to the problem of pre-ignition, maximal power of a pre-mixed or port fuel injection (PFI) engine that operates with a stoichiometric air-hydrogen mixture may be less than that of a similarly sized gasoline engine. For example, power output may be reduced by about 17% compared to a similarly sized gasoline engine due to the high partial volume of the hydrogen.

[00144] Direct injection (DI) may solve the problem of pre-ignition. If the hydrogen-rich mixture is injected after inlet valve closing (IVC), the maximum power of the engine may exceed that of a gasoline counterpart. In various studies of compressed natural gas (CNG) and hydrogen DI, the injection pressures varied from 20 bars to 120 bars. High injection pressure may allow late injection during the compression stroke and thus result in mixture stratification. Since the partial volume of gaseous fuel in the air-fuel mixture is substantial, a high injection pressure may increase the compression work of the engine's piston relative to conventional fuel engines by overcoming the pressure in the cylinder. The high injection pressure may increase penetration of the fuel into the densely charged cylinder and keep the flow choked to facilitate control over the mass flow rate.

[00145] In the case of on-board reforming, the energy required for compression may be taken into account in calculating engine efficiency. Even though isothermal compression may consume less power than isentropic compression, in many applications, including automotive, isentropic compression is commonly applied. In such an application, there is not sufficient time to enable substantial heat transfer from the compressed gas during the compression process. Although efficiency could be improved by division of the compression into stages and inter-cooling the gas between the stages, such a division may increase the weight, volume, and complexity of the engine.

[00146] In accordance with an embodiment of the present invention, a liquid fuel- water mixture use in an HCCI engine may be pressurized prior to vaporization and reforming.

[00147] Fig. 9 is a schematic illustration of an HCCI engine that operates with pressurized fuel injection, in accordance with an embodiment of the invention.

[00148] In HCCI engine system 1000, operation of components of the system is monitored and controlled by electronic control unit (ECU) 1050. For example, ECU 1050 may be configured to receive sensor readings from sensors (e.g., of pressure, temperature, or other sensed quantities) within one or more components of HCCI engine system 1000, such as mixture valve 1004, pump 1010, evaporator 1020, reformer 1030, or HCCI engine 1040.

[00149] One or more fuels, such as fuel 1002 in liquid state, may be mixed with liquid water 1003 by controlling operation of mixture valve 1004 to form liquid fuel- water mixture 1005. For example, fuel 1002 may include methanol (CH₃OH), or another alcohol or fuel. Liquid fuel-water mixture 1005 is introduced into pump 1010. Pump 1010 increases the pressure in liquid fuel-water mixture 1005 to output pressurized liquid fuel-water mixture 1015. Pressurized liquid fuel-water mixture 1015 is introduced into evaporator 1020. Evaporator 1020 vaporizes pressurized liquid fuel- water mixture 1015 to form pressurized gaseous fuel- water mixture 1025.

[00150] Pressurized gaseous fuel-water mixture 1025 is introduced into reformer

1030. Pressurized gaseous fuel-water mixture 1025 is reformed within reformer 1030 to yield reforming products 1035 (also referred to herein as a fuel product). Reforming products 1035 emerge from reformer 1030 at a pressure that is determined by operation of pump 1010.

[00151] The pressurized reforming products 1035 may be injected by injector

1042 into HCCI engine 1040. Combustion of reforming products 1035 within HCCI engine 1040 provides mechanical power (e.g., for propulsion of a vehicle) and creates heated exhaust gases 1045. Heated exhaust gases 1045 may be channeled through reformer 1030 and evaporator 1020.

[00152] For example, ECU 1050 may control operation of pump 1010 in accordance with data that is acquired from one or more sensors of HCCI engine system 1000. For example, a controlled pressure of pressurized liquid fuel-water mixture 1015 may result in a desired pressure of operation of pump 1010 may be controlled to yield a desired pressure of pressurized liquid fuel- water mixture 1015, pressurized gaseous fuel-water mixture 1025, and reforming products 1035. Control of the liquid pressure may affect the reforming pressure so as to achieve a desired injection pressure, e.g., 20 bars to 120 bars. The composition of reforming products 1035 may be affected by operation of pump 1010.

[00153] Pressurizing the fuel mixture while in liquid form may be advantageous over compressing the fuel in gaseous form at the point of injection. Since the work required for compression is relative to the specific volume of the compressed substance, the power required for compression of a liquid is smaller by several orders of magnitude than the power that would be required to compress the gaseous mixture. Thus, high pressure injection (e.g., and increased efficiency of operation of HCCI engine 1040) may be achieved while avoiding much of the loss of energy that would be required for compressing gaseous reforming products 1040 at the time of injection into HCCI engine 1040. [00154] Examples of the present invention may include apparatuses for performing the operations described herein. Such apparatuses may be specially constructed for the desired purposes, or may comprise computers or processors selectively activated or reconfigured by a computer program stored in the computers. Such computer programs may be stored in a computer-readable or processor-readable non-transitory storage medium, any type of disk including floppy disks, optical disks, CD-ROMs, magnetic-optical disks, read-only memories (ROMs), random access memories (RAMs) electrically programmable read-only memories (EPROMs), electrically erasable and programmable read only memories (EEPROMs), magnetic or optical cards, or any other type of media suitable for storing electronic instructions. It will be appreciated that a variety of programming languages may be used to implement the teachings of the invention as described herein. Examples of the invention may include an article such as a non-transitory computer or processor readable non-transitory storage medium, such as for example, a memory, a disk drive, or a USB flash memory encoding, including or storing instructions, e.g., computer-executable instructions, which when executed by a processor or controller, cause the processor or controller to carry out methods disclosed herein. The instructions may cause the processor or controller to execute processes that carry out methods disclosed herein.

[00155] Different embodiments are disclosed herein. Features of certain embodiments may be combined with features of other embodiments; thus certain embodiments may be combinations of features of multiple embodiments. The foregoing description of the embodiments of the invention has been presented for the purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form disclosed. It should be appreciated by persons skilled in the art that many modifications, variations, substitutions, changes, and equivalents are possible in light of the above teaching. It is, therefore, to be understood that the appended claims are intended to cover all such modifications and changes as fall within the true spirit of the invention.

[00156] While certain features of the invention have been illustrated and described herein, many modifications, substitutions, changes, and equivalents will now occur to those of ordinary skill in the art. It is, therefore, to be understood that the appended claims are intended to cover all such modifications and changes as fall within the true spirit of the invention.

Claims

1. An ignition and combustion control method for controlling ignition and combustion within an HCCI engine, the method comprising:

varying a fuel composition of a reformed fuel product for fueling the HCCI engine in response to changing loads or speeds of the HCCI engine by varying a water/fuel ratio of a mixture of water and fuel that is introduced into a fuel reformer to produce the reformed fuel product, and controlling a temperature of a reaction within the fuel reformer; and

fueling the HCCI engine with the fuel product.

2. The method of claim 1 , further comprising using exhaust gases from the HCCI engine for inputting into the fuel reformer.

3. The method of claim 2, wherein the exhaust gases are used to supply heat to the reaction within the fuel reformer to control the temperature of the reaction.

4. The method of claim 2 or 3, wherein the exhaust gases are used to provide water to the fuel reformer.

5. The method of any of claims 1 to 4, comprising using an electric propulsion system to power a vehicle at predetermined times.

6. The method of any of claims 1 to 6, wherein fueling the HCCI engine comprises injecting the fuel product into the HCCI engine.

7. The method of claim 6, further comprising controlling a pump to apply pressure to the mixture while in liquid form to pressurize the fuel product for injection into the HCCI engine.

8. The method of any of claims 1 to 7, further comprising vaporizing the mixture for input into the reformer.

9. A propulsion system comprising:

an HCCI internal combustion engine;

a recovery system to recover exhaust gases from the HCCI engine;

a reformer configured to use the recovered exhaust gases to perform a reforming process on a mixture of a fuel and water to produce a reformed fuel product for fueling the HCCI engine; and a control unit to vary, in response to changing loads or speeds of the HCCI engine, a composition of the reformed fuel product by varying a water/fuel ratio of a mixture of water and fuel that is introduced into the fuel reformer and by controlling a temperature of a reaction within the fuel reformer.

10. The propulsion system of claim 9, wherein the propulsion system includes an electric motor.

11. The propulsion system of claim 9 or 10, wherein the recovery system is configured to recover heat or water vapor from the exhaust gases.

12. The propulsion system of any of claims 9 to 11, wherein the recovery system is configured to dissipate heat from the exhaust gases using a radiator.

13. The propulsion system of any of claims 9 to 12, further comprising one or a plurality of condensers to condense water vapor from exhaust gases into recovered water.

14. The propulsion system of any of claims 9 to 13, wherein the control unit is configured to vary the fuel composition in real time in response to the changing loads or speeds of the HCCI engine .

15. The propulsion system of any of claims 9 to 14, further comprising an injector for injecting the fuel product into the HCCI engine.

16. The propulsion system of claim 15, further comprising a pump for applying a pressure to the mixture in a liquid state so as to control a pressure of injection of the gaseous fuel product into the HCCI engine.

17. The propulsion system of any of claims 9 to 16, further comprising an evaporator for vaporizing the mixture for introduction into the reformer.

18. The propulsion system of any of claims 9 to 17, wherein the evaporator is configured to use heat from the exhaust gases to vaporize the mixture.