GB2073317A

GB2073317A - Hydrogen-oxygen thermochemical combustion initiation

Info

Publication number: GB2073317A
Application number: GB8108748A
Authority: GB
Original assignee: ESCHER FOSTER TECH Inc
Current assignee: ESCHER FOSTER TECH Inc
Priority date: 1980-03-21
Filing date: 1981-03-20
Publication date: 1981-10-14
Also published as: DE3110511A1; IT8148071A0; JPS56146930A; ZA811856B; FR2478740A1; GB2073317B; IT1170831B; CA1171672A

Abstract

A hydrogen-oxygen thermochemical combustion initiation process and apparatus combust hydrogen in a hydrogen-oxygen combustion chamber and pass the hot hydrogen combustion products to a primary fuel combustion chamber providing mixing, chemical pretreatment and ignition of the non-hydrogen primary fuel. The apparatus and process of this invention provide improved thermal efficiency, reduced emissions and capability to employ alternative fuels in a wide variety of combustion systems having both internal and external combustion and stationary and mobile installations, such as vehicle engines, both gasoline and diesel, gas turbines, Rankine and Sterling cycle engines, furnaces and boilers, including coal and oil fired. <IMAGE>

Description

SPECIFICATION Hydrogen-oxygen thermochemical combustion initiation This invention relates to an apparatus and process using controlled combustion of hydrogen and oxygen to provide the function of combustion initiation and improved combustion in combustion-based systems. The apparatus and process of this invention provide improved thermal efficiency, reduced emissions and capability to employ alternative fuels which are otherwise difficult to combust.

The apparatus and process of this invention are applicable to a wide variety of combustion systems with both internal and external combustion and stationary and mobile installations, such as vehicle engines, both gasoline and diesel, gas turbines, Rankine and Sterling cycle engines, furnaces and boilers, including coal and oil fired.

The hydrogen-oxygen thermochemical combustion initiation apparatus and process of this invention provide a more energetic combustion initiation means than can be obtained by conventional electric- or compression-ignition means for both conventional and alternative non-petroleum based fuels, which may be difficult to combust in a broad range of combustion-based systems such as internal combustion piston engines, turbine engines, external combustion engines, furnaces and boilers.

For fuel-consuming applications, the ramifications of the limited availability of non-renewable primary energy resources and factors of energy-related environmental degradation makes consideration of improved fuel economy, reduced emissions, and conversion to non-petroleum domesically-producible alternative fuels desirable. These three objectives are highly interactive and, in a number of instances, are in conflict with one another. For example, modification to coal usage, from oil or natural gas, in electricity generating plants, provides difficult emissions control challenges and requires major boiler changes.

Combustion-related devices and systems are basic to both mobile and stationary energy conversion systems serving all industrial nations. Primary examples are the internal combustion automotive engine and electric utility boilers.

In response to these energy/environmental needs, and under the press of Government mandated regulations, constructors and users of combustion systems are attempting to improve the energy conversion efficiency or fuel economy of such systems. The recently promulated automative Federal fleet fuel economy standards (Energy Policy and Conservation Act of 1975) provides an example of this thrust. Increasing emphasis is being placed on reducing the environmental degradation impacts of combustion based systems of both mobile and stationary kinds.

The present state of development can be reviewed by examining three basic categories which encompass: improved energy conversion efficiency, or fuel economy gains; reduced environmentally-significant pollution of air, water and land, or improved emissions control technology; and implementation of alternative fuels supply and use capabilities, to reduce oil and natural gas fuel use.

Improvements in energy conversion efficiency have long been sought in the interest of good operating economy for essentially all industrial combustion-related systems. Hence, a relatively mature status has been achieved with only limited possibilities in the way of further practical gains to be made using conventional approaches. For example, the combustion efficiency achieved in modern internal combustion engines and in steam-raising boilers is usually in the high 90 percentile, e.g., 98 percent. Additional gains are intrinsically very limited.

However, in some cases avenues for measurable improvements are being pursued, such as for example, the further development of the high speed diesel engine as used in heavy trucking and in buses. The diesel engine, however, is associated with environmental pollution which could act in the future to limit its use and/or impede potential fuel economy gains. The automotive high-speed light-duty diesel engines in today's automobiles and light trucks employ a divided combustion chamber design, not the single chamber configuration of larger engines. In addition to the main combustion chamber in which fuel is combusted with the highly compressed air charge, an auxiliary connected chamber, referred to as a prechamber or swirlchamber, is employed.It is in this latter chamber where diesel fuel is initially injected and, in some designs, in which a starting assistance electrical glow-plug is located. The divided chamber design, although associated with thermodynamic losses of 10 to 1 5 percent in terms of fuel economy, is deemed necessary to meet automotive emissions control requirements and to insure effective ignition and high combustion efficiency. If these requirements could be met in a direct injection open (single) chamber engine, substantial overall fuel economy gains could be realized.

Work on emissions control technology has greatly intensified with specific emissions being regulated to established quantified levels.

Among these are carbon monoxide, reactive hydrocarbons, oxides of nitrogen, oxides of sulfur and particulates. Generally, the mandated levels of such emissions have been progressively reduced. Also, levels are stipulated based on the basis of regional air quality impacts and requirements, such as the State of California. Attempts at emissions control include: modified fuels preparation and admis sion, such as improved reduced-sac diesel fuel injectors; combustion process modifications, such as exhaust gas recirculation; water injection, and exhaust clean-up measures, such as oxidizing catalyst after-treatment in automobiles and limestone sulfur removal in coalfired electric generating plants.

Most emissions controls result in adverse technical effects, unfavorable constraints on operating procedures and/or added original and operational costs and is often counterproductive to achievable efficiency or fuel economy and even results in new secondary emissions, for example, the present automotive catalytic converter provides undesirable exhaust manifold backpressure which lowers efficiency, requires unleaded gasoline and associated reduced engine compression ratios which lowers efficiency, and causes noxious gaseous and liquid sulfate products, not otherwise present, to be emitted.

The lean-burn techniques being pursued in certain automative internal combustion engines substantially reduce oxides of nitrogen and carbon monoxide emissions, but due to cylinder-to-cylinder air/fuel mixture variations and, ultimately misfiring limits, reactive hydrocarbon emissions increase and combustion efficiency falls below acceptable limits.

A basic problem with alternative fuels is the incompatibility of present devices for use of such fuels. Hence, one approach is to produce alternative fuels to the same technical specifications as present petroleum-based fuels: gasoline, diesel and turbine fuels, heating oil and residual fuels. However, matching today's fuels' specifications partially or completely, starting with non-petroleum materials, for example, coal, oil shale, biomass, is difficult, expensive, and in many instances, unfeasible.

For example, the use of alternative fuels in compression-ignition diesel engines requires that a certain minimum cetane number be achieved and in gasoline-fueled spark ignition engines a minimum octane rating must be achieved. Some alternative fuels do not possess these basic qualities as required for conventional combustion devices. New approaches for fuel preparation and admission to the combustion chamber are desirable because of such facts as incompatible fuel physical state, mismatched viscosity range and improper volatility properties.

Although not used extensively as a fuel for combustion based systems, hydrogen fuel has been used in certain air supported combustion processes, utilizing atmospheric oxygen, in both stationary and mobile applications. Also, the hydrogen-oxygen combination has long been employed in the oxy-hydrogen torch used in metal cutting, welding, glassware fabrication, and other such operations.

The predominant use of hydrogen as a fuel today is in aerospace developments. The early development of the hydrogen-fueled rocket, using principally oxygen, but also fluorine and certain other oxidizers, has been described in Sloop, J.L., "Liquid Hydrogen as a Propulsion Fuel, 1945-1959", The NASA History Series, NASA SP-4404, Washington, D. C 1978.

In the 1960's hydrogen-oxygen fuelled rocket engines were developed as part of the U. S. space program. Some of these engines comprised both a main hydrogen-oxygen fed combustion chamber and several auxiliary combustion devices, a fuel-rich hydrogen-oxygen gas generator and a smallhydrogen- oxygen ''augmented spark igniter", used to initiate main chamber combustion. In the 1970's, a high combustion chamber pressure- staged combustion hydrogen-oxygen rocket engine system in the 500,000 pound thrust class, equipped with several hydrogen-oxygem combustion initiation devices, was developed by Rocketdyne for the Space Shuttle reusable launch vehicle system.

During the same time period, several small hydrogen-oxygen reaction control system and other auxiliary-purpose rocket engines were constructed and tested, however, none of these were developed to the point of operational service.

The hydrogen-oxygen rocket engine and related combustion areas provide basic technology for creating hydrogen-oxygen combustion devices operating over a wide range of reac tant flows, pressures, mixture ratios (fuel-rich, fuel-lean, and stoichiometric). This includes hydrogen-oxygen combustion initiation devices which serve to initiate combustion in the larger hydrogen-oxygen combustion systems represented by, for example, main rocket thrust chambers. The use of such hydrogenoxygen combustion initiation devices for producing ignition in combustion-based systems employing other than the hydrogen-oxygen reactant combination has not been known to the present inventors to ignite hydrocarbon systems such as internal combustion piston engines, gas turbines, external combustion type heat engines, furnaces or boilers.

Another proposed application of hydrogenoxygen combustion devices is the stoichiometric hydrogen-oxygen combustor in which wa-* ter diluent is added to provide a very compact, highly controllable output in terms of pressure, temperature, flow and dynamic response, special purpose steam generator as described in U. S. Patent 1,483,917. Such systems have been proposed for high efficiency vehicle prime movers and for electricity generation using special high temperature steam expanders by Rockwell International, Rocketdyne Division in "A Non-Polluting Noiseless Engine for Powerplant Applications -With Specific Orientation to a High Speed Ground Transportation System", W. J. D.

Escher, D. S. Goalwin and R. E. Schnurstein, Rocketdyne Division, Rockwell International, Report RIP-13, July, 1970, and the General Electric Co. in "Role of Hydrogen in Eco Energy", W. Hausz, General Electric Co.

TEMPO Center for Advanced Studies paper in Hydrogen for Energy Distribution, Institute of Gas Technology Symposium paper, January, 1979, Chicago, Illinois. Escher Technology Associates proposed such a system for automotive vehicle propulsion as described in "On The Higher Energy Form of Water (H2O*) in Automotive Vehicle Advanced Power Systems", W. J. D. Escher, Escher Technology Associates paper, 7th Intersociety Energy Conversion Engineering Conference, proceedings, September, 1972, San Diego, California.

More recently, Rocketdyne has studied this approach for producing electric utility generation plant steam using various thermodynamic cycles including conventional Rankine cycle condensing steam turbines as described in "Hydrogen/Oxygen Steam Generation: An Example of Aerospace Technology Transfer", D. E. Wright, Rocketdyne Division, Rockwell International, paper in Hydrogen for Energy Distribution, Institute of Gas Technology symposium paper, January, 1979, Chicago, Illinois. For these applications of the hydrogenoxygen combustion principle, it is observed that steam generation is the single objective pursued.

A large number of potential applications of hydrogen-air combustion based systems have been proposed and some of these have reached the experimental research. These range from automotive vehicle internal combustion engines to marine gas turbines to subsonic, supersonic and hypersonic aircraft powerplants including gas turbine systems, composite rocket/air-breathing propulsion systems, and subsonic-and supersonic-combustion ramjets as surveyed in "Survey and Assessment of Contemporary U. S. Hydrogen Fuelel Internal Combustion Engine Projects", W. J. D. Escher, Escher Technology Associates report for the U. S. Energy Research and Development Administration, ER DA Report TEC-75/005, September, 1 975.

There have been studies of hydrogen supplementation to conventionally fueled combustion related systems, such as internal combustion engines as described in "Emission Control with Lean Operation Using Hydrogen Supplemented Fuel", R. F. Stebar and F. B.

Parks, General Motors Corporation Research Publication GMRL-1537, February, 1974; "Hydrogen-Enrichment-Concept, Preliminary Evaluation", Anon., Jet Propulsion Laboratory Report prepared under Interagency Agreement ERA-IAG-Dr-0548, U. S. Energy Research and Development Administration, Report TEC-74/007, December, 1 975. In hydrogen supplemented otherwise conventionally fueled combustion related devices, the prime objective is to extend the "lean burn" limits of hydrocarbon fuels and to thus achieve measurable improvements in fuel economy and emissions. Various hydrogen supplementation proposals have been made for achieving the desired lean-out characteristics in internal combustion engines.The major differences in such proposals related to the source of hydrogen, particularly with regard to vehicle onboard hydrogen availability as described in "Lean Combustion in Automotive Engines: An Assessment of the Addition of Hydrogen to Gasoline as Compared to Other Techniques", Anon., The Aerospace Corporation report prepared under EPA Contract No.

E[04-3]-1101, PA-3, U. S. Department of Energy Report CONS/1 101-1, February, 1 976. Among the proposals are: storage as a pressurized gas; production of hydrogen-rich gases from hydrocarbon liquids, including the main conventional fuel used, such as gasoline, or other chemical compounds as described in "Hydrogen-Enrichment-Concept, Preliminary Evaluation", Anon., Jet Propulsion Laboratory Report prepared under Interagency Agreement ERA-IAG-D4-0548, U. S.

Energy Research and Development Administration, Report TEC-74/007, December, 1975; metal hydride storage as described in "Hydrogen Storage in Metal Hydrides", J. J.

Reilly, and G. D. Sandrock, Scientific American, February, 1980; cryogenic liquid, and the electrolysis of water as described in "Automotive Fuei-Saving System with On-Board Hydrogen Generation and Injection into l.C.

Engines", D. A. Kelley, Technidyne, Inc. Paper presented at the 1 st World Hydrogen Energy Conference Proceedings, March, 1978, Miami Beach, Florida, and "Method and Apparatus for Operating Combustion Engines", P. F. Talenti, U. S. Patent No.

4,111,160(1978) September 5.

One disadvantage of hydrogen supplementation schemes is that rather substantial amounts of hydrogen, relative to the conventional fuel, on an equivalent energy basis, are required to produce the desired fuel economy gains and emissions reductions. The need for extensive hydrogen storage and/or onboard hydrogen generation equipment with attendant cost and/or operating efficiency penalties have acted to limit and even arrest further development of the hydrogen supplementation proposals. The prior art has not, to the knowledge of the inventors, utilized hydrogen-oxygen thermochemical combustion initiation as a "chemical spark plug" or in a fuel pretreatment chamber as a combustion initiation and enhancement means for a different, non-hydrogen primary fuel whose combustion primarily takes place in a conventional fuel combustion chamber with air.

The present invention provides use of the hydrogen and oxygen reactant combination in trace amounts, relative to hydrogen supplementation proposals referred to above, to produce its beneficial effects in combustion re lated systems being served by the device. The hydrogen-oxygen storage/generation means of this invention can be of relatively small size and attendant costs and efficiency reductions, if any, are modest in view of the overall benefits provided.

It is an object of this invention to overcome disadvantages of prior combustion based systems by provision of an apparatus and process for fuel pre-processing and combustion initiation.

It is another object of this invention to provide a more effective ignition means for combustion of conventional and alternative primary fuels than presently used electrically or thermally energized devices such as spark plugs and glow plugs and air compression heating.

It is yet another object of this invention to provide an apparatus and process to improve the operating efficiency and reduce adverse ignition delay related effects such as overly rapid combustion pressure rise rates and excess mechanical loads in systems such as Otto and diesel cycle engines.

It is still another object of this invention to pre-process fuel by thermochemically and mechanically atomizing, vaporizing, chemically modifying, mixing, and igniting the fuel prior to its being combusted in order to improve operating efficiency and to reduce or otherwise favorably change emissions.

It is still another object of this invention to utilize otherwise wasted energy, such as that associated with elevated temperature exhausts or coolants and vehicle braking energy, for electricity generation powered water electrolysis yielding hydrogen and oxygen for the hydrogen-oxygen thermochemical combustion initiation process and apparatus of this invention.

It is yet another object of this invention to provide a combustion initiation apparatus and process enabling conventionally fueled system, using fuels such as gasoline in homogeneous fuel/air mixtures, to operate at leaner conditions than otherwise possible for improved fuel economy and reduced emissions levels.

It is yet another object of this invention to provide a combustion initiation apparatus and process for improving the operation of systems employing heterogeneous fuel/air mixtures, such as stratified charge Otto-cycle engines, over that presently used which involves electrical ignition and direct fuel injection.

It is yet another object of this invention to provide a combustion initiation apparatus and process enabling high speed diesel engines to advantageously employ direct cyclinder injection open combustion chamber configurations as used in medium and low speed diesel engines, instead of presently used pre-chamber and swirl-chamiber configurations to reduce thermodynamic losses ared thereby improve fuel economy.

It is still another object of this invention to provide a combustion initiation apparatus and process for fuel ignition and combustion in diesel engines to reduce engine emissions, specifically particulates and oxides of nitrogen.

It is yet another object of this invention to provide a combustion initiation apparatus and process to reduce fuel cetane rating limitations, thus permitting a wider range of fuels to be used in diesel engines than the presently required specification distillate fuels.

It is still another object of this invention to provide a combustion initiation apparatus and process to provide modification of present combustion systems to enable them to employ primary fuels other than those for which they were designed.

It is still another object of this invention to provide a combustion initiation apparatus and process to significantly reduce oxides of nitrogen emissions in conventionally fueled liquidfuel high temperature combustion systems, such as gas turbines, by local and near instantaneous pre-vaporization of the fuel, thereby avoiding the high-temperature near-stoichiometric combustion regions surrounding burning fuel droplets.

It is still another object of this invention to provide a combustion initiation apparatus and process yielding a combustion initiation device which may be installed into existing combustion systems with minimum modification or which may be readily integrated into new design systems.

These and other objects, advantages, and features of this invention will be apparent from the description and by reference to the drawings wherein preferred embodiments are shown as: Figure 1 is a schematic flow diagram of a hydrogen-oxygen thermochemical combustion initiation apparatus and process according to this invention; Figure 2 is a combined schematic flow diagram and schematic sectional view of one embodiment of the apparatus and process of this invention in a conventionally fueled internal combustion engine; Figure 3 is a combined schematic flow diagram and schematic sectional view of another embodiment of this invention in which part or all of the conventional fuel is admitted to the engine via the combustion initiation device having a single combustion/ reaction chamber; ; Figure 4 is a combined schematic flow diagram and schematic sectional view of another embodiment of this invention in which part or all of the conventional fuel is admitted to the engine via a staged secondary chamber within the combustion initiation apparatus downstream of the hydrogen-oxygen combustion; and Figure 5 is a schematic diagram of a vehicular engine system according to one embodiment of this invention using an on board water electrolyzer to provide hydrogen and oxygen.

Fig. 1 shows hydrogen-oxygen thermochemical combustion initiation system 10 in schematic functional diagram form. The hydrogenoxygen thermochemical combustion initiation system 10 comprises control system 12, hydrogen-oxygen supply system 1 3 and hydrogen-oxygen thermochemical combustion initiation device 11.Multiple hydrogren-oxygen supply systems 1 3 and multiple hydrogenoxygen thermochemical combustion initiation devices 11 may be utilized in a single hydrogen-oxygen thermochemical combustion initiation system 1 0. Combustion based system 14 may be any quasi-steady-state, cyclic or pulsing combustion system having internal or external combustion such as internal combustion vehicle engines, including gasoline, diesel and other hydrocarbon fueled; gas turbines, Rankine and Stirling cycle based external combustion engines; furnaces and boilers. Both conventional and alternative primary fuels may be used. Stationary and mobile installations may be used.

Fig. 1 shows control system 12 which comprises control means 101, ignition feed means 102, pressurized oxygen feed means 103, pressurized hydrogen feed means 104 and primary fuel feed means 105. Contral means 101 coordinates and controls all of the components of control system 1 2 as indicated by coordination means 106 in communication with the components of control system 1 2.

Control means 101 and coordination means 106 may be any electronic, electromechanical and/or mechanical means to achieve the desired results as described in this description and will be readily apparent to one skilled in the art. Control means 101 is coordinated with combustion based system 1 4 by combustion system coordination means 107 to provide primary fuel to combustion based system 1 4 and to provide ignition, oxygen, hydrogen and primary fuel, if desired, to hydrogenoxygen thermochemical combustion initiation device 11 and to effect quantity control and time sequencing to obtain desired operation of combustion based system 14.The electronic circuitry or mechanical means may act in response to a signal supplied by chemical analysis of combustion in combustion based system 14, as in the case of furnaces, or from flywheel rotation, in the case of internal combustion engines, comprising combustion system coordination means 107 to control means 101 for coordination of hydrogen-oxygen thermochemical combustion initiation system 10 with combustion based system 1 4.

Ignition feed means comprises ignition control means 102, ignition energy source means 108 and ignition device means 122 supplying ignition via ignition feed 1 21 for hydrogenoxygen thermochemical combustion initiation device 11. Ignition energy source means 108 may be any suitable electric supply such as commercial power lines, electrochemical cells, batteries, alternators, generators and the like capable of supplying desired electricity. Ignition device means 122 may be a spark plug, glow plug or other electric ignitor.

Pressurized oxygen feed means comprises oxygen control valve means 103, oxygen source means 111 and oxygen injection means 119. Oxygen control valve means 103 may be an electronically or mechanically controlled valve controlling the timing and rate of flow of oxygen through oxygen injection means conduit 11 9 to hydrogen-oxygen thermochemical combustion initiation device 11.

Oxygen source means 111 is any suitable oxygen source, such as commercial pipeline supplies, storage tanks or production device for provision of oxygen containing gases to oxygen control valve means 103. By the terminology "oxygen" as used throughout this specification and claims, we mean any gas containing more than about 75 volume percent oxygen while not containing chemicals which are deleterious to combustion or provide undesired combustion products. Preferably the gas contains more than about 95 volume percent oxygen.

Pressurized hydrogen feed means comprises hydrogen control valve means 104, hydrogen source means 11 2 and hydrogen injection means 1 20. Hydrogen control valve means 104 may be an electronically or mechanically controlled valve controlling the timing and rate of flow of hydrogen through hydrogen injection means conduit 1 20 to hydrogenoxygen thermochemical combustion initiation device 11.Hydrogen source means 11 2 is any suitable hydrogen source, such as commercial pipeline supplies, storage tanks or production devices for provision of hydrogen containing gases to hydrogen control valve means 1 04. By the terminology "hydrogen" as used throughout this specification and claims, we mean any gas containing more than about 75 volume percent hydrogen while not containing chemicals which are deleterious to combustion or provide undesired combustion products. Preferably the gas contains more than about 94 volume percent hydrogen.

Pressurized oxygen and hydrogen feed means must provide those gases under sufficient pressure to assure entry of the gases into the hydrogen-oxygen combustion chamber and to obtain desired mixing under primary fuel combustion chamber pressure conditions and mode of operation. For example, when the primary fuel combustion chamber is the cylinder of an internal combustion engine operating in a cyclic mode, the pressure must be greater than when the combustion chamber is a- substantially atmospheric pressure operated furnace. Generally, the pressurized oxygen and hydrogen feed means provides gases pressurized about 1.1 to 2.0 times the pressure of the air or other gases in the hydrogenoxygen combustion chamber at the time of entry of the gases.In psi, this might range from a few psi (5-10) differential pressure to the order of 2000 psi in a diesel engine where peak cylinder pressures may be the order of 1 500 psi. These pressures may be provided by any suitable means of compression known to the art, such as by compressors, pumps or a pressure-electrolyzer.

Particularly for vehicles it is desired to have an onboard hydrogen-oxygen supply system shown as 1 3 in Fig. 1. Onboard storage may be achieved by pressurized gaseous or cryogenic liquid storage. Chemical storage, such as metal hydride hydrogen containment, known to the art are suitable. Hydrogen-oxygen supply means 1 33 may preferably be a water electrolyzer means. Suitable electrolyzer means include alkaline electrolyte unipolar or dipolar devices such as produced by the Electrolyzer Corporation Ltd., Toronto, Canada, and Teledyne Energy Systems, Timonium, Maryland, respectively, or General Electric Company's SPE solid polymer electrolyte electrolysis systems.Feedstock water is supplied to hydrogen-oxygen supply means 1 33 by water supply means 110 and necessary energy for electrolysis is supplied to hydrogenoxygen supply means 1 33 by energy supply means 109 which may be any battery or electrical generation means. Suitable electrical generation means include an engine drive generator, regenerative braking electrical generation, exhaust energy recovery electrical generation such as a turbine expander or Rankine bottoming cycle apparatus, or other energy conservation or recovery means, alone or in combination. Various water electrolyzer systems are known to the art and vehicle onboard electrolyzer systems previously proposed and demonstrated are suitable for use in the present invention which utilizes relatively small amounts of oxygen and hydrogen.

The amount of hydrogen used in the apparatus and process of this invention, based upon chemical energy provided by hydrogen and primary fuel, is about 0.5 to about 1 5 percent chemical energy derived from hydrogen and the balance from the primary fuel.

Hydrogen energy amounts at about 1 to about 8 percent of the total are preferred. The amount of oxygen supplied may be the stoichiometric amount for oxidation of the hydrogen, in whicb case only hot combustion products are provided for ignition of the primary fuel in the primary fuel combustion chamber; less than the stoichiometric amount, in which case some excess hydrogen in addition to hot combustion products is provided to the primary fuel combustion chamber to aid combustion of the primary fuel or; more than the stoichiometric amount, in which case some excess oxygen in addition to hot combustion products is provided to the primary fuel combustion chamber to aid in oxidation of the primary fuel.

Primary fuel feed means comprises primary fuel control valve means 105, primary fuel source means 11 3 and primary fuel injection means. Primary fuel control valve means 105 is preferably an electronically or mechanically controlled valve controlling quantity and sequencing of primary fuel through primary fuel feed 115, mixing the primary fuel with air supplied through air supply means 11 6 to provide the desired primary fuel/air ratio through fuel/air supply means 11 7 to combustion based system 14.As previously disclosed, combustion based system 14 may be any suitable internal or external combustion system for combustion of primary fuel which may be any gaseous, liquid or solid hydrocarbon or other non-hydrogen fuel, such as natural gas, substitute natural gas, liquefied petroleum gas, gasoline, kerosene, diesel oil, other middle distillate fuels, residual oil, alcohols such as methanol and ethanol, ammonia, vegetable oil derivatives, coal, peat and others.

Primary fuel source means 11 3 provides the above fuels or mixtures thereof and provides desirable pretreatments prior to supply to primary fuel control valve means 105. The terminology "primary fuel" as used in this disclosure and the appended claims refers to a fuel other than hydrogen and is the fuel which supplies the principal chemical energy which is utilized for energy conversion by combustion based system 14. The principal combustion of the primary fuel takes place in the airsupplied combustion based system 14. A portion, or all, of the primary fuel may be supplied by primary fuel control valve means 105 to primary fuel feed means 114 for introduction directly to hydrogen-oxygen thermochemical combustion initiation device 11.

By reference to Figs. 1 and 2 it is seen that a hydrogen-oxygen thermochemical combustion initiation device according to this invention comprises hydrogen-oxygen combustion chamber walls defining an elongated hydrogen-oxygen combustion chamber having a first closed end and an opposite second end providing communication with the primary fuel combustion chamber of a combustion based system; pressurized hydrogen feed means comprising hydrogen control valve means, hydrogen source means and hydrogen injection means providing hydrogen containing gas to the hydrogen-oxygen combustion chamber; pressurized oxygen feed means comprising oxygen control valve means, oxygen source means and oxygen injection means providing oxygen containing gas to the hydrogen-oxygen combustion chamber; ignition means comprising ignition control means, ignition source means and ignition device means providing ignition energy in the first closed end of the hydrogen-oxygen combustion chamber to ignite the hydrogen-oxygen mixture therein and the combustion products thereof passing through the second end to the primary fuel combustion chamber; primary fuel feed means comprising primary fuel control valve means, primary fuel source means and primary fuel injection means providing primary fuel to the primary fuel combustion chamber, the primary fuel being ignited by combustion products from said hydrogen-oxygen combustion chamber; and control means in coordination communication with the combustion based system, ignition means, hydrogen control valve means, oxygen control valve means and primary fuel valve means to provide quantification and time sequencing of ignition, hydrogen and oxygen to the hydrogen-oxygen thermochemical combustion initiation device and primary fuel to the primary fuel combustion based system.

Fig. 2 shows one embodiment of hydrogenoxygen thermochemical combustion initiation device 11 in conjunction with an internal combustion piston engine of the carbureted or intake valve port fuel injection type as used, for example, in vehicular propulsion. A single cylinder of the engine is shown by cylinder walls 126 and piston 1 31. Primary fuel combustion chamber 1 27 is provided primary fuel through fuel-air supply conduit 11 7 controlled by intake valve 1 28. Conventional carburetor or fuel injection system 11 8 may be used to provide suitable primary fuel and air mixture to fuel-air supply conduit 11 7. Following combustion in primary fuel combustion chamber 127, exhaust gases are permitted to exit by opening exhaust valve 1 29 for communication with exhaust conduit 1 30. Combustion system coordination means 107 is shown as coordinating control means 101 coordinating with the engine crankshaft position.

Fig. 2 shows hydrogen-oxygen thermochemical combustion initiation device 11 which comprises hydrogen-oxygen combustion chamber 1 24 defined by hydrogen-oxygen combustion chamber walls 1 23 with ignition device means 1 22 at one end and orifices 1 25 at the other end providing communication from hydrogen-oxygen combustion chamber 1 24 to primary fuel combustion chamber 1 27. As shown in Fig. 2, hydrogen is the only fuel provided to hydrogen-oxygen combustion chamber 1 24 by hydrogen feed means conduit 1 20. Oxygen is supplied to hydrogen-oxygen combustion chamber 1 24 by oxygen feed means conduit 11 9. Ignition device means 1 22 is shown as a spark plug provided with electrical feed by ignition feed means 121. Hydrogen is combusted in hydrogen-oxygen combustion chamber 1 24 and the high temperature oxidation products pass through orifices 125 into primary fuel combustion chamber 1 27 providing ignition energy for the primary fuel.With the hydrogenoxygen combustion in hydrogen-oxygen combustion chamber 124, high temperatures, up to about 6000"F, may be obtained and the combustion product gases from hydrogen-oxygen combustion chamber 1 24 may be accelerated to high velocities, as high as the order of 10,000 feet per second, for injection to a primary fuel pretreatment or combustion chamber providing prompt and even ignition and combustion of the primary fuel throughout primary fuel combustion chamber 1 27.

Orifices 1 25 are arranged to disperse the hot hydrogen-oxygen combustion products throughout primary fuel combustion chamber 1 24. The admission of the hot hydrogenoxygen combustion product gases through orifices 1 25 is controlled with respect to velocity, direction and general distribution to efficiently effect primary fuel-air mixing, ignition and combustion.

The hydrogen-oxygen thermochemical combustion initiation process of this invention comprises providing hydrogen and oxygen to a hydrogen-oxygen combustion chamber which is in communication with the primary fuel combustion chamber of a combustion based system; igniting and substantially combusting the hydrogen in the hydrogen-oxygen combustion chamber; passing the hot hydrogen combustion products from the hydrogenoxygen combustion chamber to the primary fuel combustion chamber; and providing primary fuel to the primary fuel combustion chamber, the hot hydrogen combustion products igniting the primary fuel.

Fig. 3 shows another embodiment of the hydrogen-oxygen thermochemical combustion initiation device 11 wherein at least a portion of the primary fuel is admitted directly to hydrogen-oxygen combustion chamber 1 24 by primary fuel feed conduit means 11 4.

Additional primary fuel may also be admitted to primary fuel combustion chamber 1 27 through conventional carburetor or fuel injection system 11 8 and primary fuel feed conduit means 11 5. Also shown in Fig. 3, hydrogen-oxygen combustion chamber 1 24 has open end 1 32 in communication with primary fuel combustion chamber 127. This embodiment is especially useful when a large portion or all of the primary fuel is supplied to hydrogen-oxygen combustion chamber 1 24 for heating, chemical processing, mixing and ignition by means of the products of hydrogen combustion. However, in the embodiment shown in Fig. 3, the principal combustion of the primary fuel takes place with air in primary fuel combustion chamber 1 27.

Fig. 4 shows another embodiment of a hydrogen-oxygen thermochemical combustion initiation device 11 according to this invention. In this embodiment, hydrogen-oxygen combustion chamber 1 24 is in communication through orifices 1 25 with pretreatment chamber 1 34 portion of primary fuel combustion chamber 127.Pretreatment chamber 1 34 is in communication through pretreatment chamber open end 1 35 with the main volume of primary fuel combustion chamber 127 In the embodiment shown in Fig. 4, hydrogen is combusted with oxygen in hydrogen-oxygen combustion chamber 1 24 as described with respect to Fig. 2 and all or a portion of the primary fuel is supplied by primary fuel feed 114 to annular primary fuel injection chamber 1 36 and passes through primary fuel orifices 1 37 for intimate contact and mixing with the hydrogen combustion product passing from hydrogen-oxygen combustion chamber 1 24 through orifices 1 25.

The heated, mixed, chemically processed primary fuel and combustion products from hydrogen-oxygen combustion chamber 1 24 pass through pretreatment chamber open end 1 35 to primary fuel combustion chamber 1 27 where combustion of the primary fuel takes place with air. Additional primary fuel may be supplied to primary fuel combustion chamber 1 27 by primary fuel feed 11 5 through conventional carburetor or fuel injection system 11 8. This embodiment is particularly preferred when pretreatment of the primary fuel is desired, including atomization, vaporization, partial oxidation and hydrocracking which takes place due to the hot hydrogen-oxygen combustion products which may additionally contain hydrogen or oxygen.

While the above description with respect to Figs. 2, 3 and 4 has described an embodiment of this invention wherein the combustion based system is an internal combustion engine, it can be readily seen that valves 1 28 and 129 and piston 131 may be removed and primary combustion chamber 1 27 provided with suitable fuel preparation and burning means may be the combustion chamber of a coal or oil fed stationary furnace or boiler. In such case, the exhaust conduit 1 30 is advantageously located at the opposite end of the combustion chamber 127.

Fig. 5 shows, in a schematic fashion, one preferred embodiment of the apparatus and process of this invention for vehicular application. Hydrogen-oxygen thermochemical combustion initiation system device 11 is coupled to internal combustion engine 14 in the manner previously described. Primary fuel is stored in primary fuel storage means 1 8 and supplied to hydrogen-oxygen thermochemical combustion initiation system device 11 and/or engine 1 4 by primary fuel feed means 114. Hydrogen and oxygen are supplied to hydrogen-oxygen thermochemical combustion initiation device 11 by hydrogen injection means 1 20 and oxygen injection means 119, respectively.Hydrogen and oxygen are supplied by electrolyzer 1 6 and stored in pressurized hydrogen accumulator 1 9 and pressurized oxygen accumulator 20. Onboard water storage means 1 7 provides water to electrolyzer 1 6 while generator 15, which may be a DC generator or an AC generator with rectifier, provides electricity for electrolyzer 1 6.

Generator 1 5 may be powered by coupling to engine 1 4 directly or may be coupled to the engine exhaust recovery system, regenerative braking system, or other energy convservation or recovery system as previously described.

The vehicular application of the apparatus and process of this invention is one preferred embodiment due to the low hydrogen and oxygen consumption as compared with prior proposed onboard combustion systems associated with hydrogen supplementation of conventional fuels in engines.

The apparatus and process of this invention increases thermal efficiency of the combustion based system by providing better controlled ignition, more complete and better controlled combustion, leaner overall operation, particularly with Otto cycle systems, provide more optimum heat release during the combustion phase and simplifying combustion chamber design in a single combustion chamber in diesel and stratified charge engines, rather than employing divided combustion chambers.

Emissions from the combustion based system utilizing the apparatus and process of this invention are reduced due to more complete combustion, suppression of nitrogen oxides formation by reduction of local peak temperature zones and reduction of particulates by primary fuel treatment in the pretreatment chamber.

The invention renders alternative fuels more feasible for use in view of the positive and energetic ignition provided for the primary fuel, such as rendering low cetane fuels suitable for combustion in diesel engines. The invention renders hard to burn fuels more amenable to effective and efficient combustion by use of the energetic combustion-based ignition means or by injection of the fuels into the hydrogen-oxygen combustion chamber or pretreatment chamber and providing the hydrogen-oxygen combustion product pretreatment of the primary fuel prior to introduction into the combustion based system. These and the specific objects and advantages of this invention set forth above may be achieved by one skilled in the art upon reading of the above disclosure.

One particularly preferred embodiment of the hydrogen-oxygen thermochemical combustion initiation apparatus and process of this invention is for use in light-duty automotive diesel engine applications. A current problem with diesel fueled vehicular engines is that they typically emit in the order of 30 to 80 times the quantity of particulates than corresponding equivalent gasoline fueled engines.

The apparatus and process of this invention reduces the light-duty vehicular diesel engine particulate emissions to the level of equivalent gasoline engines or lower while maintaining the same or superior fuel economy. The apparatus and process of this invention additionally improves the cold start and engine operating noise problems associated with the light-duty vehicular diesel engine and provides capability for use of lowered cetane rated fuels than presently used vehicular diesel engines.

An exemplary embodiment of application of the hydrogen-oxygen thermochemical combustion initiation device of this invention to the light-duty automotive diesel engine is illustrated in Fig. 4. In this embodiment, the crankshaft position of the diesel engine is communicated mechanically by means of timing gears, shafts or chains to control means 101 to coordinate the injection of hydrogen, oxygen, ignition energy and diesel fuel to meet the diesel engine requitements over the full speed and load operating range as signaled to the engine by means of the acceleration pedal. Synchronization of the hydrogenoxygen flow and ignition energy input to the hydrogen-oxygen combustion chamber is mechanically achieved by combination of the diesel engine crankshaft rotation and the accelerator position.This synchronization can be further adjusted by devices sensitive to engine speed, such as a centrifugal advance mechanism. The hydrogen and oxygen control valves are mechanically operated by a rotating or sliding shaft which also serves to close the ignition electrical contact periodically for a spark plug or continuously for a glow plug to provide ignition, hydrogen and oxygen to the hydrogen-oxygen combustion chamber. Hydrogen and oxygen are fed to the hydrogenoxygen combustion chamber in a stoichiometric ratio of 1 part by weight hydrogen to 8 parts by weight of oxygen. Hydrogen-oxygen combustion is initiated by the spark plug or glow plug in the hydrogen-oxygen combustion chamber as the piston approaches the end of its stroke minimizing the volume of the primary fuel combustion chamber.The combustion of hydrogen and oxygen in the hydrogenoxygen combustion chamber results in partly dissociated water vapor at temperatures of about 5500"F. These energetic hydrogen combustion products are discharged through orifices into the primary fuel pretreatment portion of the combustion chamber while primary diesel fuel is simultaneously injected into the pretreatment chamber, as shown in Fig. 4, to vigorously interact, fully vaporizing, chemically processing and thermally igniting the primary diesel fuel which expands and passes into the main portion of the primary fuel combustion chamber containing the engine piston. Air is added for combustion of the diesel fuel in the main portion of the primary fuel combustion chamber where combustion takes place smoothly and completely.

The droplet burning mechanism of conventional diesel combustion normally resulting in particulate emissions formation is completely avoided by this combustion process. The power stroke of the piston of the diesel engine having been initiated in this fashion, the operating cycle steps of expansion, exhaust, intake and compression, are carried out in the conventional manner. The injection pressures of the diesel fuel are about 2500 to 3500 Ib/in2 since extreme atomization is not required in the injection stage itself. Conventional automotive diesel engines utilize fuel injection pressures in the order of 1 2000 to 1 7000 Ib/in2 in order to obtain the high degrees of atomization necessary for the combustion processes of the presently used engines.This preferred mode of practice of this invention utilizing automotive-type diesel engines uses the subsystems as shown in Fig. 5. A DC electrical generator is driven directly by the diesel engine and may optionally be supplemented by other electrical power sources such as an auxiliary generator driven by the engine exhaust energy recovery system or an auxiliary generator driven by a regenerative electric braking system. The water electrolyzer is a pressure-type electrolyzer of solid polymer electrolyte (SPE) type as described by General Electric Company (supra). A suitable water storage tank capable of providing sufficient pressurized water to the electrolyzer is provided. A pressurized hydrogen-gas accumulator and a pressurized oxygen gas accumulator with suitable sensing instrumentation transducers, circuitry and information processing devices is used to coordinate system operation.Initial quantities of hydrogen and oxygen for engine start up and the beginning of the warm up period are supplied from the respective pressurized gas accumulators. As these reactants are used, the pressure levels in the accumulators falls and a pressure sensing switch signals for an increase in engine driven generator electricity which results in added load on the engine. This electricity is supplied to the water electrolyzer creating immediate generation of high pressure hydrogen and oxygen gas and water flow to the electrolyzer from the water storage tank is controlled by a high pressure positive displacement pump.

The accumulators are thus maintained at the desired pressure as hydrogen and oxygen are supplied to the engine.

The hydrogen-oxygen thermochemical combustion initiation device as described with respect to the automotive diesel engine reduces particulate emissions to the same levels as comparable gasoline engines due to the improved diesel fuel combustion process and elimination of the fuel droplets ignition-combustion particulate formation mechanism of current diesel engines. The device of this invention permits elimination of the present divided combustion chamber and use of an open combustion chamber of direct injection configuration resulting is a fuel efficiency improvement of about 1 5 to 20 percent. This more than makes up fuel use attributable to electrical generation to supply the electrolyzer.

The highly energetic hydrogen-oxygen combustion heat available instantly on engine starting reduces engine cold start problems.

Engine noise and undue internal loads due to ignition delays which lead to very high chamber pressure rise rates occurring in the conventional automotive diesel engine will be greatly reduced by the positive, smooth and high energy ignition effect of the hydrogenoxygen combustion product. Since the diesel engine according to this invention does not depend upon compression ignition and in view of the provision of positive highly energetic hydrogen-oxygen combustion heat, reduced cetane rating fuels are usable.

While in the foregoing specification this invention has been described in relation to certain preferred embodiments thereof, and many details have been set forth for purpose of illustration, it will be apparent to those skilled in the art that the invention is susceptible to additional embodiments and that certain of the details described herein can be varied considerably without departing from the basic principles of the invention.

Claims

1. A hydrogen-oxygen thermochemical combustion initiation device comprising: hydrogen-oxygen combustion chamber walls defining an elongated hydrogen-oxygen combustion chamber having a first closed end and an opposite second end providing communication with the primary fuel combustion chamber of a combustion based system; pressurized hydrogen feed means comprising hydrogen control valve means, hydrogen source means and hydrogen injection means providing hydrogen containing gas to said hydrogen-oxygen combustion chamber; pressurized oxygen feed means comprising oxygen control valve means, oxygen source means and oxygen injection means providing oxygen containing gas to said hydrogen-oxygen combustion chamber; ignition means comprising ignition control means, ignition source means and ignition device means providing ignition energy in said first closed end of said hydrogenoxygen combustion chamber to ignite the hydrogen-oxygen mixture therein and the combustion products thereof passing through saidsecond end to said primary fuel combustion chamber; primary fuel feed means comprising primary fuel control valve means, primary fuel source means and primary fuel injection means providing primary fuel to said primary fuel combustion chamber, the primary fuel being ignited by said combustion products from said hydrogen-oxygen combustion chamber; and control means in coordination communication with said combustion based system, said ignition means, said hydrogen control valve means, said oxygen control valve means and said primary fuel valve means to provide quantification and time sequencing of ignition, hydrogen and oxygen to said hydrogen-oxygen thermochemical combustion initiation device and primary fuel to said primary fuel combustion based system.

2. The hydrogen-oxygen thermochemical combustion initiation device of Claim 1 wherein said primary fuel feed means additionally comprises a second primary fuel injection means providing a portion of said primary fuel to said hydrogen-oxygen combustion chamber.

3. The hydrogen-oxygen thermochemical combustion initiation device of Claim 1 wherein said primary fuel combustion chamber additionally comprises pretreatment chamber walls defining a pretreatment chamber portion in communication with said opposite end of said hydrogen-oxygen combustion chamber on one side and said primary fuel combustion chamber on the opposite side, said primary fuel feed means providing primary fuel only to said pretreatment chamber portion of said primary fuel combustion chamber.

4. The hydrogen-oxygen thermochemical combustion initiation device of Claim 1 wherein said primary fuel combustion chamber additionally comprises pretreatment chamber walls defining a pretreatment chamber portion in communication with said opposite end of said hydrogen-oxygen combustion chamber on one side and said primary fuel combustion chamber on the opposite side and said primary fuel feed means additionally comprises a third primary fuel injection means providing at least a portion of said primary fuel to said pretreatment chamber.

5. The hydrogen-oxygen thermochemical combustion initiation device of Claim 2 wherein said primary fuel combustion chamber additionally comprises pretreatment chamber walls defining a pretreatment chamber portion in communication with said opposite end of said hydrogen-oxygen combustion - chamber on one side and said primary fuel combustion chamber on the opposite side, said primary fuel feed means providing primary fuel only to said pretreatment chamber portion of said primary fuel combustion chamber.

6. The hydrogen-oxygen thermochemical combustion initiation device of Claim 2 wherein said primary fuel combustion chamber additionally comprises pretreatment chamber walls defining a pretreatment chamber portion in communication with said opposite end of said hydrogen-oxygen combustion chamber on one side and said primary fuel combustion chamber on the opposite side and said primary fuel feed means additionally comprises a third primary fuel injection means providing at least a portion of said primary fuel to said pretreatment chamber.

7. The hydrogen-oxygen thermochemical combustion initiation device of Claim 1 wherein said oxygen and hydrogen source means comprises water electrolyzer means.

8. The hydrogen-oxygen thermochemical combustion initiation device of Claim 7 wherein electrical energy for said water electrolyzer means is provided by an electrical generator driven by said combustion based system.

9. The hydrogen-oxygen thermochemical combustion initiation device of Claim 7 wherein electrical energy for said water electrolyzer means is provided by regenerative braking system means on a vehicle.

10. The hydrogen-oxygen thermochemical combustion initiation device of Claim 7 wherein electrical energy for said water electrolyzer means is provided by an exhaust energy recovery means on the exhaust of said combustion chamber.

11. The hydrogen-oxygen thermochemical combustion initiation device of Claim 2 wherein said oxygen and hydrogen source means comprises water electrolyzer means.

1 2. The hydrogen-oxygen thermochemical combustion initiation device of Claim 3 wherein said oxygen and hydrogen source means comprises water electrolyzer means.

1 3. The hydrogen-oxygen thermochemical combustion initiation device of Claim 4 wherein said oxygen and hydrogen source means comprises water electrolyzer means.

14. The hydrogen-oxygen thermochemical combustion initiation device of Claim 5 wherein said oxygen and hydrogen source means comprises water electrolyzer means.

1 5. The hydrogen-oxygen thermochemical combustion initiation device of Claim 6 wherein said oxygen and hydrogen source means comprises water electrolyzer means.

1 6. The hydrogen-oxygen thermochemical combustion initiation device of Claim 1 wherein said ignition source means comprises an electrical generator.

1 7. The hydrogen-oxygen thermochemical combustion initiation device of Claim 1 6 wherein said ignition device means is spark plugs or glow plugs.

1 8. The hydrogen-oxygen thermochemical combustion initiation device of Claim 1 wherein said primary fuel injection means comprises a carburetor.

1 9. The hydrogen-oxygen thermochemical combustion initiation device of Claim 1 wherein said primary fuel injection means comprises injection nozzles.

20. The hydrogen-oxygen thermochemical combustion initiation device of Claim 1 wherein said oxygen and hydrogen source means comprises water electrolyzer means, said ignition device means comprises spark plugs or glow plugs, and said primary fuel injection means comprises a carburetor.

21. The hydrogen-oxygen thermochemical combustion initiation device of Claim 2 wherein said oxygen and hydrogen source means comprises water electrolyzer means, said ignition device means comprises spark plugs or glow plugs, and said primary fuel injection means comprises a carburetor.

22. The hydrogen-oxygen thermochemical combustion initiation device of Claim 3 wherein said oxygen and hydrogen source means comprises water electrolyzer means, said ignition device means comprises spark plugs or glow plugs, and said primary fuel injection means comprises a carburetor.

23. The hydrogen-oxygen thermochemical combustion initiation device of Claim 4 wherein said oxygen and hydrogen source means comprises water electrolyzer means, said ignition device means comprises spark plugs or glow plugs, and said primary fuel injection means comprises a carburetor.

24. The hydrogen-oxygen thermochemical combustion initiation device of Claim 5 wherein said oxygen and hydrogen source means comprises water electrolyzer means, said ignition device means comprises spark plugs or glow plugs, and said primary fuel injection means comprises a carburetor.

25. The hydrogen-oxygen thermochemical combustion initiation device of Claim 6 wherein said oxygen and hydrogen source means comprises water electrolyzer means, said ignition device means comprises spark plugs or glow plugs, and said primary fuel injection means comprises a carburetor.

26. The hydrogen-oxygen thermochemical combustion initiation device of Claim 1 wherein said oxygen and hydrogen source means comprises water electrolyzer means, said ignition device means comprises spark plugs or glow plugs, and said primary fuel injection means comprises injection nozzles.

27. The hydrogen-oxygen thermochemical combustion initiation device of Claim 2 wherein said oxygen and hydrogen source means comprises water electrolyzer means, said ignition device means comprises spark plugs or glow plugs, and said primary fuel injection means comprises injection nozzles.

28. The hydrogen-oxygen thermochemical combustion initiation device of Claim 3 wherein said oxygen and hydrogen source means comprises water electrolyzer means, said ignition device means comprises spark plugs or glow plugs, and said primary fuel injection means comprises injection nozzles.

29. The hydrogen-oxygen thermo chemical combustion initiation device of Claim 4 wherein said oxygen and hydrogen source means comprises water electrolyzer means, said ignition device means comprises spark plugs or glow plugs, and said primary fuel injection means comprises injection nozzles.

30. The hydrogen-oxygen thermochemical combustion initiation device of Claim 5 wherein said oxygen and hydrogen source means comprises water electrolyzer means, said ignition device means comprises spark plugs or glow plugs, and said primary fuel injection means comprises injection nozzles.

31. The hydrogen-oxygen thermochemical combustion initiation device of Claim 6 wherein said oxygen and hydrogen source means comprises vvater electrolyzer means, said ignition device means comprises spark plugs or glow plugs, and said primary fuel injection means comprises injection nozzles.

32. A hydrogen-oxygen thermochemical combustion initiation process comprising: providing hydrogen and oxygen to a hydrogen-oxygen combustion chamber which is in communication with the primary fuel combustion chamber of a combustion based system; igniting and combusting said hydrogen in said hydrogen-oxygen combustion chamber; passing the hot hydrogen combustion products from said hydrogen-oxygen combustion chamber to said primary fuel combustion chamber; and providing primary fuel to said primary fuel combustion chamber, said hot hydrogen combustion products igniting said primary fuel.

33. The process of Claim 32 wherein about stoichiometric amounts of hydrogen and oxygen for combustion of the hydrogen are provided to said hydrogen-oxygen combustion chamber.

34. The process of Claim 32 wherein greater than the stoichiometric amount of hydrogen, required for combustion with oxygen provided, is provided to said hydrogen-oxygen combustion chamber.

35. The process of Claim 32 wherein less than the stoichiometric amount of hydrogen, required for combustion with oxygen provided, is provided to said hydrogen-oxygen combustion chamber.

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36. The process of Claim 32 wherein at least a portion of said primary fuel is provided to said hydrogen-oxygen combustion chamber.

37. The process of Claim 32 wherein said primary fuel is provided only to a pretreatment chamber portion of said primary fuel combustion chamber, said pretreatment chamber having one side in communication with said hydrogen-oxygen combustion chamber and the other side in communication with said primary fuel combustion chamber.

38. The process of Claim 32 wherein at least a portion of said primary fuel is additionally providednto a pretreatment chamber portion of said primary fuel combustion chamber, said pretreatment chamber having one side in communication with said hydrogen-oxygen combustion chamber and the other side in communication with said primary fuel combustion chamber.

39. The process of Claim 36 wherein said primary fuel provided to said primary fuel combustion chamber is provided only to a pretreatment chamber portion of said primary fuel combustion chamber, said pretreatment chamber having one side in communication with said hydrogen-oxygen combustion chamber and the other side in communication with said primary fuel combustion chamber.

40. The process of Claim 36 wherein at least a portion of said primary fuel is additionally provided to a pretreatment chamber portion of said primary fuel combustion chamber, said pretreatment chamber having one side in communication with sayd hydrogen-oxygen combustion chamber and the other side in communication with said primary fuel combustion chamber.

41. The process of Claim 32 wherein a substantially steady state combustion of primary fuel is conducted in said combustion chamber.

42. The process of Claim 32 wherein a cyclic combustion of primary fuel is conducted in said combustion chamber.

43. The process of Claim 32 wherein said primary fuel is selected from the group consisting of natural gas, substitute natural gas, liquefied petroleum gas, gasoline, kerosene, diesel oil, middle distallate fuels, residual oil, alcohol, vegetable oil derivatives, coal and peat.

44. The process of Claim 32 wherein said primary fuel combustion chamber is at substantially atmospheric pressure.

45. The process of Claim 32 wherein said primary fuel combustion chamber is at an elevated pressure of about 1 to about 300 atmospheres.

46. The process of Claim 32 wherein said hydrogen and oxygen is supplied by electrolyzing water.

47. The process of Claim 46 wherein electricity for electrolyzing water is produced by electrical generating means driven by said combustion based system.

48. The process of Claim 47 wherein said electricity is produced by a vehicular regenera- tive braking system.

49. The process of Claim 47 wherein said electricity is produced by an exhaust energy recovery system.

50. The process of Claim 32 wherein hydrogen is provided in an amount providing about 0.5 to 1 5 percent of the chemical energy derived from both hydrogen and primary fuel.

51. The process of Claim 32 wherein hydrogen is provided in an amount providing about 1 to 8 percent of the chemical energy derived from both hydrogen and primary fuel.

52. A hydrogen-oxygen thermochemical combustion initiation device, substantially as described with reference to, or as shown in, any of Figs. 1 to 5 of the drawings.

53. A hydrogen-oxygen thermochamical combustion initiation process, substantially as described with reference to any of Figs. 1 to 5 of the drawings.