Method and system for providing fuel to internal combustion engines

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METHOD AND SYSTEM FOR PROVIDING fuel is prepared for injection and combustion in a special FUEL TO INTERNAL COMBUSTION device, an absorber, where the fuel is contacted with the gas or ENGINES gasses. The gas pressure inside the absorber is maintained higher than the fuel pressure Supplied to the absorber; the gas

CROSS REFERENCE TO RELATED is dissolved in the liquid fuel forming an unsaturated fuel APPLICATIONS Solution having no free gas phase. The resultant fuel Solution 0001. The present application is a continuation of appli is guided to a main fuel pump that further increases the cation Ser. No. 12/798.513, filed Apr. 6, 2010, the entire pressure of the fuel Solution providing no free gas phase. disclosure of which is incorporated herein by specific refer Upon injection in the combustion chamber in addition to the ence thereto. hydrodynamic fuel atomization a violent degassing takes place providing continuous chainbreaking of fuel microdrop

FIELD OF INVENTION letto fine “nano' sizes. The combination of the gas desorption from the fuel solution with the hydrodynamic breaking-up of 0002 The present invention relates to liquid fuel combus the injected fuel provides a fundamentally new process of the tion and, more particularly, to the preparation of liquid fuels fuel atomization in the combustion chamber. The fuel micro for combustion in a combustion chamber of internal combus droplets continuously break up to significantly Small sizes tion engines. providing an extremely high interfacial curvature and liquid

BACKGROUND OF THE INVENTION

vapor (fuel) pressure increases by as much as 8-10 times. This effect is described by the Kelvin equation and it is well known 0003. In existing internal combustion engines such as die that the quicker liquid fuel evaporates the more rapid and sel and gasoline engines, as well as other types of engines a effective the combustion of the gasoline or diesel is. One more fuel is injected into a combustion chamber at high pressure. A important additional effect of the new injection process: the charge of the fuel is injected by means of Solenoid injectors continuous chain breaking of the fuel droplets caused by the controlled by an on-board microcomputer and connected to a gas desorption prevents coalescence of the droplets and for common rail. The on-board microcomputer controls injection mation of a fuel film on the walls of the combustion chamber. timing and duration as well as an injection pressure by means As a result more fuel surface is available for contact with air. of a two-stage main fuel pump. To provide better fuel atomi Thus the fuel burns faster and more completely giving less Zation after injection into combustion chamber the fuel pres harmful emissions.

Sure in the common rail upstream the injectors is maintained 0008 Taking into account this and other objects a method at high level, e.g., in diesel engines the fuel pressure is main of fuel activation and Supplying into the combustion process tained at 2000-2400 bars. is presented. The method comprises steps of 0004 Currently different approaches are used to improve 0009 a) Dissolving a gas/mix of gasses in fuel thereby the fuel atomization and dispersion in the combustion cham transferring the liquid fuel into a state of unsaturated “fuel/ ber after injection. For example, jointinjection of hydrogen or gas' solution without any free gas phase; the fuel is dispersed natural gas with gasoline is used, in other systems a com in the absorber to increase the contact Surface with the gas pressed air stream is directed to the fuel spray injected into the supplied to the absorber at high pressure of up to 100 bar; the combustion chamber. There is also an approach where fuel process is performed, preferably, at lower temperatures, and and air are induced with the same charge to reduce coales gas used for dissolution can be a mixture of for example, cence of the fuel microdroplets after the injection. exhaust gases and oxygen enriched air having O content of 0005. There are known attempts to disperse fuel by dis up to 35% and fuel/mixture of gases ratio by weight of 1:0. Solving some gas, e.g., air or carbon dioxide, in the liquid fuel 055. The purpose of using the mixture with increased oxygen and Subsequently injecting this solution into the combustion content is to increase the local concentration of the oxidant chamber. When injected into the combustion chamber the during gas desorption. The presence of locally available oxi dissolved gas is released from the Solution providing very fine dant helps more quicker fuel ignition. dispersion of the liquid fuel. In U.S. Pat. No. 6,273,072 0010 b) Activating “fuel/gas' solution by changing the (Knapstein et al.) and U.S. Pat. No. 701 1,048 (Gurinet al.), state of the “fuel/gas” solution for a short period of time to a there are described methods and devices for implementation boundary state of oversaturated Solution in Such way as to and utilization of the abovementioned effect. The described minimize or exclude free gas bubbles flashing out of the fuel systems require special devices that are Supposed to work solution flow at the inlet of the main fuel pump by lowing the within a certain range of parameters and at the same time pressure of the fuel solution flow or by ultrasound treatment certain conditions should be observed to provide the fuel/gas in a hermetic vessel comprising a vibrating element that by Solution to the combustion chamber in proper condition. In ultrafast oscillations forms partial pressure decrease of the practice it is difficult to satisfy both of these requirements fuel solution flowing through the vessel. simultaneously, and the achieved effect is not stable at various 0011 c) Merging the recirculation fuel solution flows loads. pumped out after the injection from common rail and main

SUMMARY OF THE INVENTION

fuel pump, cooling down the fuel solution to 50° C. and guiding it to the absorber to separate free gas/fuel vapor 0006 An object of this invention is to provide a method phase.

and apparatus which overcomes the abovementioned disad 0012 d) In the fuel system with single stage main fuel vantages and which provides for further improvement in the pump and distributed injection pumps the return flow is fuel injection into the combustion chamber that reduces fuel cooled, separated from free gas/fuel vapor phase and guided consumption as well as emissions. to the inlet of the main fuel pump. Some fuel after the main 0007. In accordance with invention there are provided fuel pump is guided to a nozzle of a jet pump which is used to technical solutions for different types of fuel systems. The pump out free gas/fuel vapor phase from a gas separator and

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the mix flow then is fed to the absorber to separated liquid and 0025. The activation system according to the present gas phases. This helps to avoid gas or vapor bubbles appear invention consists of two Subsystems: a conditioning Sub ing that may create pressure pulses at the outlet of the main system and a gas preparation Subsystem. fuel pump and affect the operation of the fuel injectors. 0026. The conditioning subsystem comprises an absorber 0013 e) Preparing the gas mixture to be used for dissolu 10, a feeding pump 11, a differential pressure regulator 12, a tion in the fuel by cooling and compressing the exhaust gases jet pump 15. Three-way valves 14 and 16 are used to change and mixing it with oxygen enriched air formed by filtering from standard (base) fuel Supply system to the conditioning compressed air through a special membrane filter, prepared subsystem and vice versa. Check valves 18, 19 prevent fuel to gas mixture is guided to the absorber for dissolving in the flow in wrong direction.

liquid fuel. 0027. The gas preparation subsystem comprises a reactor 0014 With this and other objects in view there is provided, 13 and two air and exhaust gases Supply lines. Air from air in accordance with the invention, a system for liquid fuel source 26 flows through a filter 28, a compressor 29, a pres activation and feeding activated liquid fuel to the combustion Sure regulator 30, and an oxygen enrichment membrane filter chamber for combustion, comprising: 31, a check valve 27 prevents air to flow in wrong direction; 00.15 a) an absorber for fuel conditioning, having a liquid exhaust gases from exhaust line of the engine 20 flows inlet port for providing a fresh liquid fuel from a fuel tank, a through a filter 22, a cooler 23, a compressor 24 and a pressure gas inlet port for providing gas orgas mixture, an inlet port for regulator 25, check valve 21 prevents exhaust gasses to flow providing returned fuel flows from an engine common rail in wrong direction.

and main fuel pump, and an outlet port for Supplying a fuel 0028. The gas mixture is prepared in the reactor 13 by Solution from the absorber to an engine; mixing the exhaust gases as sources of CO with oxygen 0016 b) a fuel solution activator for momentary transfer enriched air that is formed after ambient air passes through ring the fuel Solution to a state of oversaturated Solution the oxygen enrichment membrane filter 31. Mixing of two gas thereby preparing the fuel Solution to a burst gas desorption at streams in equal portions by weight is provided by pressure injection into the combustion chamber, regulators 25 and 30 having common control line. Required pressure of the gas mixture is provided by compressors 24 and 0017 c) a fuel supply subsystem for supplying the fresh 29 and controlled by the pressure regulators 25 and 30. liquid fuel to the absorber with maintaining fuel level inside (0029. The fuel from fuel tank 3 is delivered by feeding the absorber between min and max limits: pump 11 to the nozzles mounted in the absorber 10. The 0018 d) a subsystem for collecting returned flows from feeding pump 11 provides the fuel pressure P. The gas mix the engine and main fuel pump, separating free gas/fuel ture from the reactor 13 is guided to the gas inlet port of the vapor, cooling down to 50° C. and guiding the returned flows absorber 10 under gas pressure P which is controlled by to the inlet port of the main fuel pump; pressure regulator 17. Pressure regulator 32 maintains the gas 0019 e) a control system for controlling the fuel supply pressure inside the absorber 10 at set level P. The gas pres and engine operation. sure P, is set lower than the fuel pressure P providing satis 0020. The system and method of operation of the inven factory working condition for the fuel dispersing by the tion with additional objects and advantages thereof will be nozzle in absorber 10. The dispersing of fuel in gas results in best understood from the following description of specific achieving a significant amount of gas being dissolved in fuel. embodiments when read in connection with the accompany An outlet port located at the bottom of the absorber 10 is ing drawings. fluidically connected to the inlet port of the main fuel pump 2. The differential pressure regulator 12 positioned in the con

BRIEF DESCRIPTION OF THE DRAWINGS nection line between the absorber 10 and main fuel pump 2 temporarily reduces the fuel solution pressure. The reduced 0021 FIG. 1 shows one of the an embodiment of the pressure transfers the fuel solution into the boundary state of invention for internal combustion engines having common saturated Solution thus facilitating the gas desorption from the rail injection system. fuel by destroying sorption links between liquid and gas 0022 FIG. 2 shows another embodiment of the invention molecules. This step improves effectiveness of the desorption for internal combustion engines having common rail injec process at injection and improves the atomization of the tion system. injected fuel charge. In addition the differential pressure regu 0023 FIG. 3 shows an embodiment of the invention for lator 12 compensates for pressure spikes arising during the diesel engines having fuel Supply system with fuel distribu absorber 10 operation. Instead of differential regulator 12 an tion pump. ultrasonic magnetostrictive actuator in a hermetical vessel through which a liquid fuel/gas Solution flows can be used.

DETAILED DESCRIPTION OF THE DRAWINGS Main fuel pump 2 again increases the pressure of the fuel Solution as much as 2 times and returns the fuel solution in the 0024 FIG. 1 of the drawing shows one of the possible state of unsaturated solution. In Such state the main fuel pump embodiments of the system for an internal combustion engine 2 delivers the fuel solution to the common rail 1 and unit having common rail injection system. The internal combus injectors (not shown) for combustion. tion engine can be a standard diesel or gasoline engine. The 0030. It is well known that the gas solubility in liquid is engine comprises a common rail injection system 1, a two proportional to the partial pressure of the gas over the liquid stage main fuel pump 2, a fuel tank 3, a primary fuel filter 4, Surface and the concentration of the gas dissolved in liquid is a fine fuel filter 5. The common rail injection subsystem in inverse proportion to the liquid temperature. As the fuel comprises unit injectors (not shown) for injecting fuel charge Solution parameters in Supply line are maintained higher than into a cylinder combustion chambers and fluidically con parameters in the combustion chamberatinjection in addition nected with the outlet ports of the common rail. to hydrodynamic breaking of fuel stream by injector the gas

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dissolved in the fuel solution violently escapes from the liquid 0037. The present invention is not to be construed as lim thus providing additional atomization of the fuel to more ited to the forms shown which are to be considered illustrative finest aerosol as well as even distribution over the volume of rather than restrictive.

the combustion chamber. The faster evaporation on superfine fuel microdroplets at high temperature present in the com 1. A system for conditioning liquid fuel and directing con bustion chamber provides speedy propagation of the flame ditioned fuel Solution to an internal combustion engine, said front. This way faster and more efficiently burnt fuel delivers system including; an absorber with a fuel inlet port for intake more energy at optimal piston and crankshaft position. As a of fresh fuel from a fuel tank and inlet port for intake return result it takes less fuel to produce the same amount of power, fuel Solution flows from a common rail and injectors of said as well as provides a reduction of emissions. engine and main fuel pump, a gas inlet port for intake of gas 0031 Since the main fuel pump 2 delivers more fuel than for absorption into said fuel forming the conditioned fuel the internal combustion engine can consume to produce use solution, and fuel outlet port for discharge of said fuel solu ful power recirculation lines are provided for returning excess tion from said absorber to said engine and a closed circuit fuel. Recirculation fuel solution flows from common rail is recirculation comprising return lines to recycle unused con cooled down to 50°C. in cooler 6 and then merged with 1 first ditioned fuel Solution from the main fuel pump and common stage of the main fuel pump 2 in the jet pump 15: Recircula rail and injectors after injection; wherein joint return flow tion fuel Solution from the common rail having higher pres from common rail and injectors of said engine is cooled and sure is guided to the nozzle of the jet pump 15: the ejected then joint return flows from said engine and main fuel pump flow creates low pressure in the mixing chamber and recircu are merged in a jet pump, and a common return flow is guided lation flow from first stage of the main fuel pump 2 is sucked to the absorber.

into the mixing chamber of the jet pump thus providing lower 2. A system for conditioning liquid fuel and directing con pressure at the drainage port of the main fuel pump and better ditioned fuel to an internal combustion engine, said system conditions for gas separation. including; an absorber with a fuel inlet port for intake of fresh 0032. Three-way valves 14 and 16 are used to switch fuel from a fuel tank and inlet port for intake return fuel between conditioned mode and base mode of engine opera Solution flows from a common rail and injectors of said tion. In conditioned mode operation the mixed recirculation engine and main fuel pump, a gas inlet port for intake of gas fuel solution flow from jet pump 15 is guided to the recircu for absorption into said fuel, and fuel outlet port for discharge lation inlet of the absorber. In base mode both valve are set to of said fuel from said absorber to said engine and a closed initial position and recirculation flow fromjet pump is guided circuit recirculation to recycle unused conditioned fuel solu to the fuel tank 3. tion from the main fuel pump and common rail and injectors 0033. In another embodiment (FIG. 2) a gas separator can after injection; wherein the closed circuit recirculation com be provided in recirculation line for removing free gas/fuel prises means for mixing joint return flows from common rail vapor phase from recirculation fuel solution flow. The recir and injectors of said engine and return flow from main fuel culation flow is cooled, preferably, to 50° C. in a cooler 6 and pump; means for cooling the common return flow; means for is then guided to the gas separator 7. The liquid fuel Solution collecting and separating free gas/fuel vapors from common from gas separator is fed to the inlet of main fuel pump 2 and return flow and guiding the separated free gas/fuel vapors to separated free gas/fuel vapor is guided to the gas port of the the absorber, and means for mixing a common return flow absorber 10 using a low pressure compressor 8. without free gas bubbles with fresh activated fuel solution 0034 FIG.3 shows a preferred embodiment for an internal from absorber and guiding to the inlet port of the main fuel combustion engine having one-stage main fuel pump 2 and pump.

distributed unit injectors 1. In conditioned mode operation the 3. A system for conditioning liquid fuel and directing con recirculation flow from unit injectors 1 contains high concen ditioned fuel to an internal combustion engine, said system tration of dissolved gasses So it is guided back to the inlet of including; an absorber with a fuel inlet port for intake of fresh the main fuel pump. But passing through a cylinder head it fuel from a fuel tank and inlet port for intake return fuel contains some free gas/fuel vapor that should be separated Solution flow from unit injectors of said engine, a gas inlet from the recirculation flow as it may damage the unit injec port for intake of gas for absorption into said fuel, and fuel tors. The recirculation flow is cooled preferably to 50° C. in a outlet port for discharge of said fuel from said absorber to said cooler 18 and free gas/fuel vapor is separated in a gas sepa engine and a closed circuit recirculation to recycle unused rator 19. A jet pump 15 is used to remove separated free conditioned fuel solution from unit injectors after injection, gas/fuel vapor from the gas separator 19. To provide operation wherein the closed circuit recirculation comprises means for of the jet pump 15 some fuel after the main fuel pump 2 is cooling the return flow; means for collecting and separating guided to the nozzle of the jet pump 15 and the low pressure free gas/fuel vapors from the return flow; means for guiding created by the ejected flow sucks the separated free gas/fuel the separated free gas/fuel vapors to the absorber, and means vapor. The mixed flow from the jet pump is guided to the for mixing the return flow without free gas bubbles with fresh absorber 10. To keep the pressure at the inlet of unit injectors activated fuel solution from absorber and guided to the inlet 1 at required level the pressure regulator 36 is used. port of the main fuel pump.

0035) To shut the engine off or at idle operation the fuel 4. The system according to claim3, wherein the means for Supply should be switched to the base mode using three-way guiding the separated free gas/fuel vapors include a jet pump; valves 14 and 16 and shutting out the fuel supply to the a line for directing a part of the fuel solution after the main absorber 10. fuel pump and before the fuel filter to a nozzle of the jet pump; 0036 Before parking the vehicle for a long period of time lines for directing separated free gas/fuel vapors to a mixing the cylinder head and the fuel supply should be flushed from chamber of the jet pump and further to the absorber; a pres conditioned fuel by operating the engine on the base uncon sure regulator to keep the fuel solution pressure at the inlet of ditioned fuel for about 30-90 seconds. the fuel filter at predetermine level.

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5. The system as defined in claim 1, further including a (b) a second mode operational with conditioned fuel Sup solution activator for transferring conditioned fuel solution to ply at normal engine operation under load; a boundary Saturated gas/fuel condition in order to reduce (c) a third mode of fuel Supply for system purge with base Sorption links between liquid fuel and gas molecules prevent unconditioned fuel at engine shut-down for storage; ing appearing of free gas bubbles, thereby to prepare said fuel wherein said conditioned fuel Supply is shut off, uncon Solution for burst gas desorption upon injection into a com ditioned fuel is guided to said inlet port of the main bustion chamber. fuel pump, and gas from said absorber is vented to the 6. The system as defined in claim 2, further including a fuel tank.

solution activator for transferring conditioned fuel solution to 12. The system as defined in claim 2, further including a boundary Saturated gas/fuel condition in order to reduce means for controlling the fuel Supply and engine operation in Sorption links between liquid fuel and gas molecules prevent three operational modes, including: ing appearing of free gas bubbles, thereby to prepare said fuel (a) a first mode operational with base unconditioned fuel Solution for burst gas desorption upon injection into a com Supply at cold start and idle of said engine; bustion chamber. (b) a second mode operational with conditioned fuel Sup 7. The system as defined in claim 3, further including a ply at normal engine operation under load; solution activator for transferring conditioned fuel solution to (c) a third mode of fuel Supply for system purge with base a boundary Saturated gas/fuel condition in order to reduce unconditioned fuel at engine shut-down for storage; Sorption links between liquid fuel and gas molecules prevent wherein said conditioned fuel Supply is shut off, uncon ing appearing of free gas bubbles, thereby to prepare said fuel ditioned fuel is guided to said inlet port of the main Solution for burst gas desorption upon injection into a com fuel pump, and gas from said absorber is vented to the bustion chamber. fuel tank.

8. The system of claim 1, wherein the gas to be dissolved in 13. The system as defined in claim 3, further including the liquid fuel is a mixture of exhaust gas and oxygen-en means for controlling the fuel Supply and engine operation in riched air having enhanced oxygen content of up to 35%. three operational modes, including: 9. The system of claim 2, wherein the gas to be dissolved in (a) a first mode operational with base unconditioned fuel the liquid fuel is a mixture of exhaust gas and oxygen-en Supply at cold start and idle of said engine; riched air having enhanced oxygen content of up to 35%. (b) a second mode operational with conditioned fuel Sup 10. The system of claim 3, wherein the gas to be dissolved ply at normal engine operation under load; in the liquid fuel is a mixture of exhaust gas and oxygen (c) a third mode of fuel Supply for system purge with base enriched air having enhanced oxygen content of up to 35%. unconditioned fuel at engine shut-down for storage; 11. The system as defined in claim 1, further including wherein said conditioned fuel Supply is shut off, uncon means for controlling the fuel Supply and engine operation in ditioned fuel is guided to said inlet port of the main three operational modes, including: fuel pump, and gas from said absorber is vented to the fuel tank.

(a) a first mode operational with base unconditioned fuel

Supply at cold start and idle of said engine;