Abstract: Systems, methods and apparatus for controlling operation of dual fuel engines are disclosed that regulate the fuelling amounts provided by a first fuel and a second fuel during operation of the engine. The first fuel can be a liquid fuel and the second fuel can be a gaseous fuel. The fuelling amounts are controlled to improve operational outcomes of the duel fuel engine.

Abstract: Systems and methods for controlling fuel factions delivered to different cylinders are provided. In one example, a controller is configured to, during a single engine cycle and responsive to a first condition, deliver a lower fraction of a first fuel into a donor cylinder in comparison to a fraction of the first fuel being injected into a non-donor cylinder and deliver a higher fraction of a second fuel into the donor cylinder in comparison to a fraction of the second fuel being injected into the non-donor cylinder.

Abstract: Systems and apparatuses include a selective catalytic reduction system structured to receive exhaust gases from a dual fuel engine system and include a diesel exhaust fluid dosing unit, an ammonia slip catalyst positioned directly downstream of the selective catalytic reduction catalyst, an oxidation catalyst positioned directly downstream of the ammonia slip catalyst, and one or more processing circuits. The circuits receive a system out NOx value, a space velocity, an ammonia to NOx ratio, an exhaust temperature, a substitution rate, and a conversion efficiency target. The circuits determine a conversion efficiency differential, adjust the substitution rate based on the system out NOx value, adjust the ammonia to NOx ratio based on the space velocity, the ammonia to NOx ratio, the exhaust temperature, the substitution rate, the conversion efficiency target, and the conversion efficiency differential, and determine a diesel exhaust fluid dosing rate for the diesel exhaust fluid dosing unit.

Abstract: The present invention relates to a method for controlling injection of a gaseous fuel, such as hydrogen or a hydrogen based gas, and a water-based fluid medium into a combustion engine. The method comprises the steps of: in a first operational mode injecting the gaseous fuel and optionally a water based fluid medium into a combustion chamber of the engine at a relatively high pressure; in a second operational mode injecting water as liquid into engine to reduce the temperature and pressure inside the combustion chamber, and injecting the gaseous fuel into the combustion chamber at a relatively low pressure.

Abstract: A dual fuel engine control system includes a pressure sensor, and an electronic control unit coupled with the pressure sensor and structured to receive cylinder pressure data indicative of cylinder over-pressurization, and to switch the system to a limited gas-to-liquid substitution mode based on the cylinder pressure data indicative of cylinder over-pressurization. The electronic control unit is further structured to return the system to a normal gas-to-liquid substitution mode, receive cylinder pressure data indicative of cylinder over-pressurization after returning the system to the normal gas-to-liquid substitution mode, and responsively output a gas substitution fault signal.

Abstract: Various methods and systems are provided for a multi-fuel capable engine. The system includes a liquid fuel system to deliver liquid fuel to an engine, a gaseous fuel system to deliver gaseous fuel to the engine, and a control system. The control system, during a gaseous fuel system test mode, controls the liquid fuel system and the gaseous fuel system to deliver the liquid fuel and the gaseous fuel to the engine over a range of engine operating points, and indicate degradation of the gaseous fuel system based on engine output at each of the engine operating points.

Abstract: A flow manifold system for injecting a first gas into a second gas, such as, for example, a system for injecting ammonia gas into the exhaust gas of an internal combustion engine. The first gas may be supplied to the system by one or more cartridges. The system may also include a control valve that is configured to control the delivery of the first gas to the least one critical flow orifice. The critical flow orifice is configured to allow for a relatively constant volumetric flow of the first gas through the critical flow orifice when the first gas attains a critical flow. Such critical flow may allow for an accurate estimation of the flow of the first gas through the critical orifice, and subsequently to the second gas, without the use of a flow sensor.

Abstract: A control system for an engine including a fuel delivery system and an ignition source is provided. The control system includes a detector, a processor, and at least one actuator. The detector is configured to sense a signal to change from a compression ignited fuel to a spark ignited fuel. The processor is configured to receive the signal from the detector and generate an actuation signal. The actuator is configured to receive the actuation signal, vary an operating speed of the engine, and selectively control at least one of the fuel delivery system and the ignition source.

Abstract: A method of operating an internal combustion engine includes the steps of: determining an upper torque curve at which exhaust emissions from the internal combustion engine are acceptable; determining a lower torque curve at which exhaust emissions from the internal combustion engine are acceptable; and operating the internal combustion engine using a command torque curve ranging between the lower torque curve as a lower limit and the upper torque curve as an upper limit.

Abstract: The disclosure describes an engine system having liquid and gaseous fuel systems, each of which injects fuel directly into an engine cylinder. A controller monitors and controls engine operation in a normal mode, during which the engine produces rated power, and in a limp-home mode, which is used when an abnormal operating condition of the gaseous fuel system is present. During limp-home mode operation, the engine uses more liquid fuel and less or no gaseous fuel relative to the normal mode, and produces power that is less than rated power.

Abstract: A dual-fuel engine has a primary fuel supply and a secondary fuel supply, the primary and secondary fuels being arranged in use to mix with each other and with air for combustion in one or more cylinders of the engine. The supply of both the primary and secondary fuels is arranged to be actively managed in accordance with a desired engine performance characteristic by an electronic controller. In one arrangement the supply of a primary fuel is arranged to be actively reduced when a secondary fuel is supplied to the engine.

Abstract: A system for providing power to a load of a drilling rig has a dual fuel engine/generator and an energy storage system. The load is switchably connected to one or both of the dual fuel engine/generator and the energy storage system. The dual fuel engine/generator and the energy storage system have a capacity suitable for supplying requisite power to the load. A rectifier is connected to an output line of the engine/generator so as to convert the AC power to DC power. The energy storage system is a battery. The dual fuel engine/generator can be either a dedicated duel fuel system or a fumigation system.

Abstract: A method of controlling fuel injection in a dual fuel engine system includes determining, with a first controller, a diesel injection pulse indicative of a first amount of diesel fuel to be injected into a combustion chamber of the engine and a first timing at which the first amount of diesel fuel is to be injected. The method also includes determining, with a second controller, a combined injection pulse based on the diesel injection pulse. The method further includes injecting the second amount of diesel fuel and the third amount of natural gas into the combustion chamber in accordance with the combined injection pulse. In such a method, injection in accordance with the combined injection pulse results in a combustion event characterized by a second combustion characteristic substantially equal to a first combustion characteristic associated with the diesel injection pulse.

Abstract: An apparatus and method for igniting a gaseous fuel directly introduced into a combustion chamber of an internal combustion engine comprises steps of heating a space near a fuel injector nozzle; introducing a pilot amount of the gaseous fuel in the combustion chamber during a first stage injection event; controlling residency of the pilot amount in the space such that a temperature of the pilot amount increases to an auto-ignition temperature of the gaseous fuel whereby ignition occurs; introducing a main amount of the gaseous fuel during a second stage injection event after the first stage injection event; and using heat from combustion of the pilot amount to ignite the main amount.

Abstract: A system designed and structured to fully integrate LNG conversion solution for power plants associated with locomotives, which include, but are not limited to, General Electric AC 4400 and Dash-9 locomotive power plants.

Abstract: A dual fuel common rail system may be operated in a regular mode in which a relatively large charge of gaseous fuel is ignited by compression igniting a relatively small injection quantity of liquid diesel fuel. The dual fuel system may be operated in a single fuel limp home mode in which liquid diesel fuel is injected at higher pressures. When transitioning from the single fuel limp home mode to the dual fuel regular mode, accumulated leaked liquid fuel in the gaseous nozzle chamber of each fuel injector is purged and burned in the respective engine cylinder.

Abstract: A system for controlling leakage of diesel fuel into the natural gas side of a dual fuel injector during low pressure natural gas conditions comprises a leakage control valve that blocks the diesel fuel line during very low natural gas line pressure conditions, including start-up and limp-home mode conditions.

Abstract: A dual fuel injection valve with concentric needles comprises an inner needle and an outer needle surrounding the inner needle, both needles being located inside the injection valve body. The valve is provided with a first set and a second set of orifices for separately injecting two different fuels directly into the combustion chamber of an internal combustion engine. The outer needle is fixed against rotation with respect to the injection valve body such that an interlace angle between the centerlines of the first series of orifices and second series of orifices is set at different predetermined angles to reduce methane emissions.

Abstract: A method for evaluating the state of a fuel-air mixture and/or the combustion in a combustion chamber of an internal combustion engine, with sample signals of flame light signals being stored in a database, and with flame light signals of the combustion in the combustion chamber being detected and compared with the stored sample signals, and with an evaluation of the state being output in the case of coincidence between the measured and stored signal patterns. In order to enable the monitoring of the combustion in the simplest possible way the sample signals in the database are stored with the assigned emission values and an evaluation of the state of the combustion is performed with respect to the obtained emissions in the case of coincidence between the measured and stored signal patterns for the combustion chamber of the respective cylinder.

Abstract: A system for the exchange of thermal energy generated by electrical components in an electrical locker to a flow of a liquefied gas is provided. The system includes a storage container for cryogenically storing the liquefied gas at low pressure, a heat exchanger configured into the electrical locker, and a cryogenic pump in fluid communication with the storage container. The cryogenic pump pressurizes the liquefied gas received from the storage container to a higher pressure and pumps the pressurized liquefied gas to a location where vaporization of the liquefied gas into a gaseous form is performed using the thermal energy drawn from the electrical locker by the heat exchanger.

Abstract: A system includes a diesel engine and a fuel-cracking system in fluid communication with a fuel supply to the diesel engine.

Abstract: Described are methods and systems for powering an Otto-cycle engine using gasoline and compressed natural gas (CNG). The Otto-cycle engine can be powered by determining a quantity of the gasoline and a quantity of the CNG to deliver to a cylinder of the engine during an engine cycle such that combustion within the cylinder occurs at a pre-determined air-fuel ratio; delivering the quantity of the gasoline to the cylinder via a gasoline injector and delivering the quantity of the CNG to the cylinder via a CNG injector such that the gasoline and the CNG combust during the same combustion event; and combusting the gasoline and the CNG within the cylinder. Delivering CNG and gasoline to the cylinder using separate injectors allows the quantities of CNG and gasoline to vary in response to engine operating conditions, which allows the fuel mixture to be adjusted to satisfy engine power and emissions criteria.

Abstract: A gaseous-fuelled internal combustion engine and a method of engine operation improve combustion stability and reducing emissions of NOx, PM, and unburned hydrocarbons. The method comprises fuelling an internal combustion engine with hydrogen and natural gas, which can be directly injected into the combustion chamber together or introduced separately. Of the total gaseous fuel delivered to the engine, at least 5% by volume at standard temperature and pressure is hydrogen. For at least one engine operating condition, the ratio of fuel rail pressure to peak in-cylinder pressure is at least 1.5:1. A fuel injection valve introduces the gaseous fuel mixture directly into the combustion chamber. Two separate fuel injection valves could also introduce the methane and hydrogen separately. An electronic controller controls timing for operating the fuel injection valve(s). The engine has a preferred compression ratio of at least 14:1.

Abstract: The invention relates to a method for evaluating the state of a fuel/air mixture and/or the combustion in a combustion chamber of an internal combustion engine, with sample signals of flame light signals, preferably the flame intensity (FI), with associated mixture states being saved to a database, with flame light signals, preferably the flame light intensity (FI), of the combustion in the combustion chamber being detected and thus being compared with the saved sample signals, and with conclusions being drawn on the state of the mixture in the combustion chamber in the case of coincidence between measured and saved signal patterns. In order to enable a simple and precise monitoring of the mixture state and the combustion it is provided that a pressure measurement is also performed in the cylinder simultaneously with the detection of the flame light signals.

Abstract: A dual fuel injector may be used to injector both gas and liquid fuel into a cylinder of a compression ignition engine. An injector body defines a first set of nozzle outlets, a second set of nozzle outlets, a first fuel inlet and a second fuel inlet. A dual solenoid actuator includes a first armature, a first coil, a second armature and a second coil that share a common centerline. The dual solenoid actuator has a non-injection configuration at which the first armature is at an un-energized position and the second armature is at an un-energized position. The dual solenoid actuator has a first fuel injection configuration at which the first fuel inlet is fluidly connected to the first set of nozzle outlets, the first armature is at an energized position and the second armature is at the un-energized position.

Abstract: A system for supply of LPG/ammonia for direct-injection petrol or diesel engine includes an electronic control unit where the control unit governs a petrol/diesel pump, a supplementary petrol/diesel pump, a petrol/diesel-delivery solenoid vale, LPG/ammonia-return solenoid valve, LPG/ammonia pump, a supplementary LPG/ammonia pump, a LPG/ammonia-delivery solenoid vale and a LPG/ammonia injector, such that only one of LPG/ammonia and petrol/diesel is fed to the engine at any point in time, and a combination of i) LPG and petrol, ii) LPG and diesel, iii) ammonia and petrol, and iv) ammonia and diesel is never fed to the engine.

Abstract: The invention presents a method of converting a diesel fueled engine to a blended-fuel engine capable of operating on blended gaseous fuel and diesel fuel, where the diesel fueled engine has a plurality of cylinders, a plurality of diesel fuel injectors for injecting diesel fuel into the cylinders, and an Engine Control Unit (ECU) for controlling at least the operation of the diesel injectors by sending diesel fuel injector control signals to the diesel fuel injectors.

Abstract: A high pressure common rail fuel system is provided including a fuel supply, a high pressure pump assembly fluidly connected to receive fuel from the fuel supply, and a gas supply system fluidly connected to provide gas to the high pressure pump assembly to create a high pressure gas fuel mixture. A common rail fuel system is fluidly connected to the high pressure pump assembly to receive the high pressure gas fuel mixture.

Abstract: The instant invention provides an apparatus and system for cooling the air charge of an internal combustion engine. More specifically, the instant invention provides an air-induction system suitable to provide cooled air charges to turbocharged, supercharged or naturally aspirated internal combustion engines to increase power output while reducing engine emissions. The system utilizes gaseous fuel stored as a liquid wherein the liquefied gaseous fuel is vaporized and warmed at least partially with heat removed from the intake air charge supplied to the engine from the turbocharger or supercharger. In a preferred embodiment, the compressed intake combustion air is first cooled in an aftercooler against an ambiently cooled coolant and is subsequently cooled further by the chiller of the instant invention which utilizes the change in phase, between liquid and gas, of the alternative fuel to cool the incoming air charge.

Abstract: A system and method for improving fuel usage of a dual fuel engine is described. Fuel type is delivered to engine cylinders in response to operating conditions.

Abstract: Various approaches are described for controlling operation of an engine. One example method includes delivering a gaseous fuel to the engine during a first operating range when an amount of stored gaseous fuel is greater than a threshold; and disabling the delivery of the gaseous fuel during the first operating range when the amount of stored gaseous fuel is less than the threshold and delivering a second fuel to operate the engine, yet continuing to deliver the gaseous fuel to start the engine during a cold start even when the amount of stored gaseous fuel is less than the threshold.

Abstract: A dual fuel engine (2) is provided which is supplied with diesel fuel and at least one secondary fuel, such as LPG. The engine (2) has a plurality of cylinders (4, 6, 8, 10) in which pistons reciprocate. Each cylinder has diesel injectors (4A, 6A, 8A, 10A) for injecting the diesel fuel into the cylinder during an appropriate stroke of the piston and an air inlet valve (4C, 6C, 8C, 10C) which opens during the appropriate stroke of the piston to permit air flow therethrough. Each cylinder is further provided with LPG injectors (4B, 6B, 8B, 10B) for injecting the secondary fuel into the cylinders. The LPG injectors are independent to and separate from the diesel fuel injectors. The LPG and diesel fuel injectors are also independently controlled.

Abstract: A method of operating an engine is provided. The method may include supplying a combustible combination of reactants to a combustion chamber of the engine, which may include supplying a first hydrocarbon fuel, hydrogen fuel, and a second hydrocarbon fuel to the combustion chamber. Supplying the second hydrocarbon fuel to the combustion chamber may include at least one of supplying at least a portion of the second hydrocarbon fuel from an outlet port that discharges into an intake system of the engine and supplying at least a portion of the second hydrocarbon fuel from an outlet port that discharges into the combustion chamber. Additionally, the method may include combusting the combustible combination of reactants in the combustion chamber.

Abstract: In the DME fuel supply device for a diesel engine, the time necessary to retrieve DME fuel remaining in the injection system after stopping the diesel engine into the fuel tank can be reduced. In a non-injection state, a three-way valve (71) is controlled to be OFF to form a communication passage in the direction indicated by the arrow B and a two-way valve (72) is controlled to be ON. DME fuel delivered from a feed pump (5) is delivered to an aspirator (7), passed from an inlet (7a) to the outlet (7b) thereof and returned to a fuel tank (4). That is, the DME fuel circulates via the aspirator. A vapor-phase pressure delivery pipe switching solenoid valve (75) is controlled to be ON and opened so that flow can pass through a vapor-phase pressure delivery pipe (73) connecting the vapor-phase (4a) in the fuel tank (4) and the inlet of the fuel gallery (11).

Abstract: The apparatus and method convert the fuel system of an internal combustion engine in a pre-existing (used) vehicle to operate on a mixture of fuels (like ethanol and gasoline) from a single fuel tank. The apparatus includes a fuel composition sensor installed in the fuel line and an electronic control unit with at least one fuel injector driver circuit for controlling an output signal to at least one fuel injector for controlling the air to fuel ratio of the engine. The electronic control unit controls both ignition timing and the air to fuel ratio of the engine based upon the percentage or ratio of the alternative fuel to gasoline from the fuel composition sensor. The electronic control unit receives both timing signals and fuel injector control signals from the engine's original Engine Control Module and the original emission control devices are not modified or replaced.

Abstract: At least one engine operating parameter other than total fuel energy content is taken into account when transitioning between operating modes in a dual fuel or other multimode engine (20) in order to maintain a smooth transition between modes. The parameter preferably comprises at least one of primary fuel excess air ratio (lambda) and ignition timing and preferably is controlled in addition to total fuel energy content control. Lambda control is especially beneficial because it permits the control system to compensate for the engine's inability to substantially alter the instantaneous air mass in the combustion chamber during the transition period. For instance, during a transition from pilot ignited gaseous fuel mode to diesel mode, the controlled parameter preferably comprises diesel lambda, and the controlling step comprises setting diesel lambda at a relatively high value at the beginning of the transition period and thereafter reducing diesel lambda during the transition period.

Abstract: A method directly injects gaseous fuel into the combustion chamber of an internal combustion engine. The compressibility of the gaseous fuel is used to provide a fuel to the combustion chamber that is injected over all engine operating conditions at pressures that result in fuel jet speeds beyond the injector nozzle in excess of sonic speeds as determined in reference to the combustion chamber environment. The resulting fuel injection speed results in the fuel passing through shock waves within the combustion chamber, which, in turn, promotes combustion of the fuel by promoting turbulence and mixing of the fuel and intake charge within the combustion chamber where fuel burns in a non-premixed combustion mode.

Abstract: A propane injector system for internal combustion engines for improving performance, fuel efficiency, safety, cleanliness and environmental friendliness. The system consists of introducing propane gas into “a black box” that has a pressure reducing valve to drop propane pressure as it flows initially from its storage tank and through an electronically controlled on/off valve. Propane enters an injector manifold where it is distributed to two specially designed gas handling fuel injectors that act as variable flow rate pumps controlled by a programmable microprocessor that is pre programmed for specific vehicles or can be customized with improved performance programming as determined by the vehicle owner. A pressure feedback system senses when the engine blower has caused a pressure boost on its high side feeding the cylinders. Transducers located in a Manifold Absolute Pressure (MAP) sensor detect the pressure boost and communicate with the microprocessor.

Abstract: The invention provides an internal combustion engine which can be run optionally on various fuels of different energy density, in particular for a motor vehicle drive, characterised in that the engine is equipped with a supercharging compressor which can be connected up when using a low-energy-density fuel at least when power requirements are elevated, so that the engine works as a supercharged engine, whereas the supercharging compressor is shut off when using a high-energy-density fuel and the engine works as a naturally aspirating engine.

Abstract: In a method and a device for controlling the injection of fuel into an internal combustion engine, a distinction is made at least between a first state and a second state. Immediately before the transition from the first state to the second state, the injection data is altered so that the emissions, in particular the production of noise, are gradually made to approximate the emissions in the second state.

Abstract: The present invention aims to allow an arbitrary selection to be made between gas operation and diesel operation, to achieve a reduction in NOx even when in diesel operation, to allow the compression ratio to be adjusted and altered in accordance with the operating state when in gas operation, to allow quick starting, and to perform operations at a high combustion efficiency over the entire load range. The dual fuel engine of the present invention is provided with a precombustion chamber unit, which is located in the cylinder head of the dual fuel engine, having a precombustion chamber and an electromagnetic fuel injection valve (a liquid fuel injection valve) and also with a compression ratio control valve. The compression ratio control valve opens and closes an air passage that connects the main combustion chamber with an intake port.

Abstract: A Liquefied Petroleum Gas (LPG) fuel composition estimation method is provided that determines an LPG fuel composition from saturation vapor pressure data and an estimated fuel temperature and fuel pressure inside the fuel tank. A Liquefied Petroleum Gas Injection (LPI) System that employs the method is provided that employs the method of the invention.

Abstract: A control system for a dual fuel engine that can operate in either dual fuel mode or in diesel only mode includes two controllers. One controller controls operation of the gaseous fuel supply system, and the other controls the liquid fuel supply system. Each controller receives signals from sensors monitoring particular engine operation characteristics and is able to transmit the data it collects to the other controller by way of a broadband communications link such as a controller area network (CAN). When the engine is operating in dual fuel mode, one controller directly controls the gaseous fuel supply and also controls the liquid fuel supply by its control of the other controller. When the engine is operating in diesel only mode, the other controller controls all aspects of engine operation. A method of controlling operation of a dual fuel engine is also disclosed.

Abstract: A method and apparatus for operating a diesel engine under stoichiometric or slightly fuel-rich conditions, as is often necessary to maintain effective operation of certain post-combustion emission reduction devices, such as Lean NOx Traps, includes a readily vaporizable fuel injection nozzle disposed in the intake manifold system in communication with a combustion chamber of the diesel engine. The readily vaporizable fuel mixes with the intake air and produces a mixture of pre-mixed air and fuel when introduced into the combustion chamber. A diesel fuel, which is directly injected into the combustion chamber through a conventional diesel fuel injection nozzle. Combustion of the pre-mixed air and readily vaporizable fuel, with controlled injected of the diesel fuel, reduces the particulate matter (soot) emissions when operating the engine under the necessary stoichiometric or slightly fuel-rich conditions.

Abstract: A method and apparatus for injecting a gaseous fuel into a combustion chamber of an internal combustion engine (ICE) cylinder employs a combination of operating modes. First, one of a low load and a high load mode of operation is selected during the operation of the ICE. Low load and high load modes are distinguished by the combustion characteristics of an amount of fumigated fuel added to the combustion chamber. Fumigated fuel that supports combustion will cause high load to be selected. Fumigated fuel that does not support combustion will cause low load to be selected. A directly injected amount of fuel is provided under low load. Under high load, a directly injected quantity of fuel is added when the piston is near top dead center to allow the engine to meet load requirement above that provided by the fumigated fuel.

Abstract: A method and apparatus for injecting pilot fuel in a combustion engine. The method and apparatus includes determining a load of the engine, determining a desired injection timing of the pilot fuel and a desired quantity of pilot fuel to be injected as a function of a desired homogeneous distribution of the pilot fuel based on the engine load, and adjusting the injection timing and quantity of the pilot fuel to the desired values.

Abstract: A separate metering and metering unit for a diesel and/or propane or similar gas/liquid fuel powered internal combustion engine such as a dual fueled engine incorporates an intake filter, a lockout solenoid, and a metering device into a single integrated unit remote of the carburetor of the engine. The metering unit includes a heater immediately adjacent to the output of the injector metering device in order to provide heat necessary to prevent any freezing of the unit injector or gaseous fuel or oxidizers downstream of the metering unit. The injection of the propane allows for correct operation of a catalytic converter.

Abstract: A control system for a dual fuel engine that can operate in either dual fuel mode or in diesel only mode includes two controllers. One controller controls operation of the gaseous fuel supply system, and the other controls the liquid fuel supply system. Each controller receives signals from sensors monitoring particular engine operation characteristics and is able to transmit the data it collects to the other controller by way of a broadband communications link such as a controller area network (CAN). When the engine is operating in dual fuel mode, one controller directly controls the gaseous fuel supply and also controls the liquid fuel supply by its control of the other controller. When the engine is operating in diesel only mode, the other controller controls all aspects of engine operation. A method of controlling operation of a dual fuel engine is also disclosed.

Abstract: A method is provided for operating an internal combustion engine comprising a combustion chamber defined by the inner wall of a cylinder, a cylinder head and the upper surface of a piston moveable longitudinally within the cylinder, the engine further comprising a pre-combustion chamber in communication with the combustion chamber. The method comprises supplying to the combustion chamber a first combustible mixture of a first hydrocarbon fuel and oxygen; supplying to the pre-combustion chamber a second combustible mixture of a second hydrocarbon fuel and oxygen, the second combustible mixture being auto-ignitable; and compressing the first and second combustible mixtures by moving the piston within the cylinder; wherein under operating conditions in which the aforementioned steps are insufficient to operate the engine and keep it running, the method further comprises the step of generating a spark to cause ignition of the compressed first combustible mixture in the combustion chamber.

Abstract: A system for supply of LPG/ammonia for direct-injection petrol or diesel engine includes an electronic control unit where the control unit governs a petrol/diesel pump, a supplementary petrol/diesel pump, a petrol/diesel-delivery solenoid vale, LPG/ammonia-return solenoid valve, LPG/ammonia pump, a supplementary LPG/ammonia pump, a LPG/ammonia-delivery solenoid vale and a LPG/ammonia injector, such that only one of LPG/ammonia and petrol/diesel is fed to the engine at any point in time, and a combination of i) LPG and petrol, ii) LPG and diesel, iii) ammonia and petrol, and iv) ammonia and diesel is never fed to the engine.