WO2019119062A1

WO2019119062A1 - Hydrogen direct injection system

Info

Publication number: WO2019119062A1
Application number: PCT/AU2018/051387
Authority: WO
Inventors: Richard Kabzinski
Original assignee: HYDI IP Pty Ltd
Priority date: 2017-12-22
Filing date: 2018-12-21
Publication date: 2019-06-27

Abstract

A system for use with a combustion engine the combustion engine having an air intake, which includes a hydrogen cell that has an electrolysis cell for producing hydrogen gas and a hydrogen cell unit control module that is operatively connected to hydrogen pressure monitoring sensor and to the electrolysis cell and to a hydrogen gas delivery system, said hydrogen gas delivery system operable to control the delivery of hydrogen gas to the combustion engine air intake in response to predetermined signal levels from the hydrogen cell unit control module

Description

HYDROGEN DIRECT INJECTION SYSTEM

FIELD OF THE INVENTION

The present invention relates to a system for generating and providing hydrogen to a combustion engine.

In addition, the present invention relates to a system for generating and controlling the provision of hydrogen to a combustion engine in an on demand manner.

The hydrogen generated may be fed into either the engine air intake system, the engine exhaust SCR system, or to both, either directly from the electrolysis cell or via variable electronically controlled valves.

DESCRIPTION OF THE PRIOR ART

The generation of hydrogen and its subsequent use in internal combustion engines is a promising source of clean and readily sourced power.

Hydrogen is considered a clean fuel as it can react with oxygen in a fuel cell or combustion engine to produce energy and water with virtually no other reaction byproducts. The current uptake of hydrogen as a fuel has been limited, due in part to there not being systems in place in vehicles that can both control the generation of hydrogen in an on demand manner as well as control its delivery to the internal combustion engine.

There are systems/in which hydrogen is prepared and stored in a holding tank on a vehicle, which involves the use of electrolysis to split water into its respective elements of hydrogen and oxygen. Large-scale electrolysis cells are able to produce large quantities of hydrogen gas which is then subsequently stored in a storage tank as a gas or liquid, alternatively, the hydrogen may be stored chemically as a hydride which can then be catalytically reformed as required. In each case however it is necessary for the hydrogen to be first generated in an appropriate facility and then transferred to the site of use whereby it is then used as a fuel to create work.

Accordingly, for such an approach to be utilised in relation to combustion engines or vehicles generally, large-scale infrastructure needs to be in place in order to first provide sufficient centres where hydrogen may be produced and then secondly having the appropriate locations whereby the hydrogen may be stored such that it can be then dispensed in an appropriate manner, such as through a vehicle refueling station. This however creates additional problems due to the need to transport hydrogen, being a highly flammable gas, as well as having suitably prepared storage locations that are able to hold vast quantities of hydrogen in the appropriate form.

Until such time that sufficient infrastructure and demand is in place, a more convenient approach would be to have a means of generating hydrogen from water on demand, as needed. In theory, this would then only require an operator to periodically fill a water tank or other such reservoir to feed the hydrogen generating cell, which will then be able to generate hydrogen gas electrolytic ally on demand as required and then directly inject the freshly generated hydrogen into the combustion engine.

This would be particularly useful as a replacement or supplement to petrol or diesel generating engines so as to potentially reduce the amount of petrochemical material consumed as well as to reduce the particulate matter and noxious exhaust fumes such as Oxides of Nitrogen also known as NOx generated from their combustion. As an example, in order to reduce the amount of NOx emissions, many diesel engines use a diesel exhaust fluid (DEF), which is an aqueous Urea solution that is fed into and consumed by a catalyst during Selective Catalytic Reduction (SCR) so as to reduce NOx concentrations in the diesel exhaust. The use of a diesel exhaust fluid requires a separate holding tank and delivery mechanism in order to ensure that the diesel exhaust fluid is added to the engine in the appropriate concentrations in a consistent manner. In addition, operators of such engines are required to periodically check and as required top the level of diesel exhaust fluid, which at times can be difficult due to availability of the diesel exhaust fluid as well as contributing to additional running costs. Other considerations are the manufacture of the urea component of diesel exhaust fluid in the first place, which is highly energy intensive having a high carbon footprint, and the storage, mixing and distribution of the diesel exhaust fluid.

OBJECT OF THE INVENTION

It is an object of the present invention to overcome, or at least substantially ameliorate, the disadvantages and shortcomings of the prior art by replacing the diesel exhaust fluid by hydrogen generated on demand directly at the point where then engine is located, such as on a truck, generating plant or the like.

Other objects and advantages of the present invention will become apparent from the following description, taking in connection with the accompanying drawings, wherein, by way of illustration and example, an embodiment of the present invention is disclosed.

SUMMARY OF THE INVENTION

According to the present invention, although this should not be seen as limiting the invention in any way, there is described a system for generating and providing hydrogen fuel on demand to a combustion engine.

In preference, the system includes a method of controlling the delivery of the generated hydrogen fuel to the intake of the combustion engine.

In preference, the generation and provision of hydrogen is for use in a selective catalytic reduction system or converter (SCR). In preference, the system includes an electrolysis cell for the generation of hydrogen.

In preference, the electrolysis cell is a proton exchange membrane (PEM) electrolysis cell.

In preference, the system generates hydrogen via the electrolysis cell when the combustion engine is in operation. If the combustion engine is not in operation or stops operating (running) the system of generating hydrogen is disabled.

In preference, the system includes a relay or solid state switch device operatively connected between the electrolysis cell and the combustion engine.

In preference, the system includes a single or a plurality of pressure monitoring devices to monitor the pressure of hydrogen generated and being supplied to the combustion engine, one of the pressure monitoring devices being operatively connected to activate a shut-off switch to disable the electrolysis cell at a predefined pressure.

In preference, the system includes a pressure monitoring device to monitor the pressure of hydrogen generated and being supplied to the combustion engine, the pressure monitoring device being operatively connected to activate a metering valve to proportionally feed hydrogen to the engine air intake.

In preference, the system includes a pressure monitoring device to monitor the pressure of hydrogen generated and being supplied to the combustion engine, the pressure monitoring device being operatively connected to activate a second metering valve to proportionally feed Hydrogen to the selective catalytic reduction (SCR) system.

In preference, the predefined pressure in the first instance is an overpressure. In preference the pressure is monitored in real time to adjust the flow of Hydrogen gas to the engine air intake and SCR system independently.

In preference, the system includes an electronic process control system.

In preference, the electronic process control system has means for monitoring and controlling the temperature of the electrolytic cell.

In preference, the electronic process control system has means for setting and controlling and maintaining a constant current flowing through the electrolytic cell.

In preference, the electronic process control system has means for metering or dispensing hydrogen gas produced by the electrolytic cell to the engine air intake.

In preference, the electronic process control system has means for metering or dispensing hydrogen gas produced by the electrolytic cell to the selective catalytic reduction system or converter.

In preference, the electronic process control system has means for metering or dispensing hydrogen gas produced by the electrolytic cell to the engine air intake and the selective catalytic reduction system or converter.

In preference, the electronic process control system includes means for monitoring NOx emissions in the engine exhaust.

In addition to monitoring emissions, the electronic process control system is adapted to adjust or control the flow of hydrogen produced from the electrolytic cell to the engine air intake and/or selective catalytic reduction system or converter. In preference the electronic process control system includes a plurality of engine parameter sensors, such as but not limited to idling sensors, throttle position sensor, engine rpm sensor, temperature sensors, and oil pressure or level switches or sensors.

In preference, the electronic process control system includes at least one engine parameter sensor operatively connected to the electrolytic cell and at a predetermined threshold be at least one engine parameter sensor can modulate the amount of hydrogen gas generated by the electrolytic cell.

In preference, the electronic process control system has means to modulate the amount of hydrogen gas produced by the electrolytic cell in response to a predefined engine operation parameter.

In preference, the predefined engine operation parameter is at least one of the parameters selected from the group consisting of any one or multiplicity of pressure, RPM, power output, torque, speed, fuel consumption, exhaust emission level.

In preference the engine signals and sensors may also be accessed by a connection to the vehicle controller area network (CAN) bus.

In preference, the electronic process control system includes at least one process monitoring input to allow a means of determining water purity so that if the water purity is outside of a predetermined specification the system can be shut down to prevent damage to the PEMEC and other system components.

BRIEF DESCRIPTION OF THE DRAWINGS

By way of example, an embodiment of the invention is described more fully hereinafter with reference to the accompanying drawings, in which: Figures l is a diagram of the system according to one aspect of the present invention;

Figure 2 is a schematic of the electronic process control system,

Figure 3 is a schematic of the electrolytic cell of figure 2, and signal connection to the electronic process control system.

DETAILED DESCRIPTION OF THE INVENTION

The hydrogen direct injection system of the present invention is operated as a hydrogen injection system that supplies hydrogen gas to the combustion engine intake or engine air intake and the Selective Catalytic Reduction (SCR) system or converter. The primary aim of injecting hydrogen into both areas of the engine system is to reduce engine emissions, in particular NOx. The focus is to displace diesel exhaust fluid (DEF) as the primary chemical used in conjunction with a selective reduction catalytic (SCR) converter to reduce NOx emissions. DEF (diesel exhaust fluid, a solution of urea and de-ionized water) has been established as the standard fluid for reduction of NOx emissions, but adds a significant cost to running plant and equipment.

The hydrogen direct injection system of the present invention significantly reduces this imposed additional cost, by safely replacing DEF with lower cost hydrogen gas on demand, and in so doing has several other benefits, being:

• when injected into the engine air intake results in an increase in fuel burning efficiency due to the higher flame speed of burning hydrogen

• a corresponding reduction in fuel consumption

• reduction in particulate generation

• reduction in carbon monoxide emissions

• reduces NOx particularly when hydrogen is injected into the SCR system

• replaces diesel exhaust fluid with an on demand hydrogen gas supply with a corresponding reduction in cost

• replacing DEF with hydrogen reduces ammonia emissions to zero, eliminating toxic ammonia in the exhaust (which is a normal by-product of using DEF) • results in a cleaner running engine due to fewer carbon deposits

• reduces soot levels in oil resulting in longer oil service life

• reduction in the cost of engine servicing and maintenance prolonged engine component life

All of the points above result in considerable reduction of running and maintenance costs over the life of the engine. Additionally, the‘CO₂ footprint’ of the truck, plant or equipment utilising a diesel engine, or other combustion engine, with the hydrogen direct injection system of the present invention installed, would be reduced at the outset. This is because the total energy cost required to run the SCR system would be reduced, since the production of urea used in DEF, requires a considerable amount of energy input to produce. In addition, when DEF is processed in the SCR on the engine, an unwanted and undesirable by-product is the emission of ammonia, called‘ammonia slip’. The hydrogen direct injection system of the present invention results in no (zero) ammonia slip or emissions.

Components of the system

Polymer Electrolyte Membrane (PEM) electrolysis cell

A PEM electrolysis cell (PEMEC) is used for the hydrogen generation process. The PEMEC is comprised of plates and a proton exchange membrane.

The advantage of a PEMEC is that unlike acid or alkaline electrolysis cells, there is no acid or alkaline chemical added to the water in the cell to make it conduct electricity. The proton exchange membrane (PEM) replaces these conventional electrolytes and allows the use of pure distilled or deionised water in the cell. Thus the chemical hazards, corrosive effects, special materials and the complexities required to

accommodate acid or alkaline electrolytes is avoided. There are no corrosive residues, corrosion products to build up sludge such as such as iron oxide and no toxic by- products produced such as hexavalent chromium, which is a real concern with acid or alkaline cells employing stainless steel plates. The PEMEC works the same way as a conventional acid or alkaline electrolysis cell, in that a current is passed through plates in the cell in order to convert (dissociate) water into hydrogen and oxygen gasses by the action of electrolysis. The amount of hydrogen and oxygen is proportional to the current passed through the cell and can be easily controlled. Typically, more than one cell is stacked into a single PEMEC assembly and the current is passed through series connected cells to increase the amount of gas produced for the same applied current.

Water circulation pump and heat exchanger

The purpose of the water circulation pump in the present invention is:

• to clear the generated gases from the cell and prevent gas accumulation

• to circulate the water through a heat exchanger or cooling system

Gases need to be cleared from the PEMEC plates and cavities in within the cell in order to keep the cell running at optimum efficiency. If gasses are allowed to accumulate, the water will be displaced from the plates by gas bubbles reducing current flow, which in turn affects cell gas generation efficiency and increases electrical losses.

In applying an electrical current to the cell, heat is generated. This is because there is electrical resistance present, since there is no electrolysis cell available that can conduct electricity perfectly. This heat is removed from the cell by circulating water through the cell to a heat exchanger. The heat exchanger is cooled by either natural air convection or by forced air cooling employing an electric fan. The pump and fan of the present invention are controlled by an electronic process control system (EPCS) in order to keep the temperature of the cell within optimum operational limits. This results in prolonged cell life and increases safety as it reduces the likelihood that the water could reach scalding temperatures or even boil.

To prevent the water from reaching scalding or boiling temperatures, the EPCS monitors the water temperature, and in the event that a predetermined temperature is exceed, current is shut off from the PEMEC to prevent further heating of the water. Once the water temperature falls to a lower predetermined temperature, current is restored to the PEMEC.

A typical pump may be a computer liquid cooling pump which is so designed and tends to be easily obtainable at low cost. In one design, the heat exchanger comprises of a coil of plastic or silicone tubing attached to a car cooling fan with specialised clips.

However, any type of heat exchanger such as a thermoblock or small computer style ‘radiator’ can be used, since there are no corrosive electrolytes used in the system.

Water purity monitoring

The purity of the water used in the system is paramount. Distilled or deionised water must be used in the system or damage to the PEMEC may occur. The major source of contaminated water is either refilling by the operator with reticulated (tap) water or with water from some other contaminated source. Contamination such as dust, may also enter the system when water is being added. Water purity may be monitored by a variety of means including, but not limited, to an optical turbidity measurement, or by monitoring the conductivity of the water (the preferred method). The EPCS may optionally allow for the connection of one or a plurality of sensors in order to determine water purity.

A water purity measurement conducted in real time, can be connected to measure water purity in the main water supply and separator tank and allows the system to be shut down immediately in the event that any contamination is detected in the water tank, thus preventing damage to the system. One further source of contamination can as a result of a mechanical failure in the pump, where the rotating element contacts the casing in the event of a bearing failure. In this case the pump may still operate, but with contact between mechanical components, abrasion will occur and debris may be deposited into the water. As such, water purity sensors may also be located at selected location along the feed in water lines, for example upstream of the PEMEC. In addition to shutting down hydrogen gas generation, an alert can also be provided via the status lamps and/or via a Human Machine Interface (HMI) to alert the operator that there is an issue with the water supply. Optionally, the event may be permanently logged by the EPCS for diagnostic purposes. Gas delivery and safety system

The purpose of the gas delivery and safety system of the present invention, is to ensure the safe and efficient transfer of gas from the PEMEC to the engine air intake and SCR system. The first safety system of the present invention monitors the engine to determine if it is running or not. If the engine is not running or stops running, a safety interlock disables the system. Hydrogen gas is only produced when the engine is running preventing the accumulation of hydrogen in the air intake system or exhaust system. The EPCS allows for the connection of an oil pressure switch, an engine RPM sensor or a pressure sensor fitted onto the air intake at a predetermined location, to either measure air flow utilizing a pitot tube (can be a purpose designed injection nozzle), or pressure variations (pulses) caused by induction of air into the engine, in order to affect this safety interlock.

In some embodiments of the present invention, the hydrogen gas is passed through a ‘bubbler’ to isolate the gas flow from the atmosphere and possible ignition sources, so that inadvertent ignition of the hydrogen gas is prevented. A non-return valve prevents air from entering the system. The hydrogen gas can then be delivered to the engine via nylon or urethane tubing which subsequently feeds the hydrogen into a suitable port in the engine air intake system. However, any suitable tubing or solid piping may be used

The pressure in the supply line to the engine is monitored by pressure sensors and if the line is blocked or restricted the safety system will cut off gas generation by cutting power to the PEMEC. For added safety, once the system is tripped by an overpressure signal, a manual reset of the system will be required. A message can then be displayed and an alarm lamp lit to alert the operator to this requirement. This then forces the operator of the present invention to conduct a proper investigation into the cause of any potential blockage. In some embodiments if an overpressure alarm is triggered three times within 15 minutes without proper investigation of the cause, the system will switch off and lock out all operations until a service reset is performed by a qualified service agent. The EPCS may also be connected to a gyroscopic sensor or accelerometer sensor or both, in order to ascertain the tilt and orientation of the system enclosure. This would ensure that Hydrogen gas generation was shut off in the event that the any moving vehicle to which the system was affixed suffered a rollover or similar event, where a hazard would exist if the system remained operational.

Electronic process control system (EPCS)

The EPCS of the present invention controls the following functions:

• setting of the current flowing through the PEMEC cell(s);

• holding the set current to the required value despite cell temperature and

operating conditions;

• monitoring and control of the cell temperature by controlling the pump and fan

• determining and display of the water level in the reservoir;

• metering the hydrogen gas produced to hot the engine air intake and the SCR (NOx emissions reduction) system;

• monitoring NOx emissions and adjusting hydrogen flow to the engine air intake and SCR system;

• display of the cell and water temperatures;

• communication with the HMI (human machine interface) over wired or wireless connection ;

• determining and displaying alarm conditions;

• safety interlock

The EPCS of the present invention, which may be referred to as a hydrogen cell unit control module, employs state-of-the-art microcontroller and power control electronics to modulate the current to the PEMEC. This is necessary to maintain a constant set current into the cell to maintain a specific hydrogen gas flow. Once the current level in amps is set, the EPCS maintains the set level regardless of cell temperature and supply voltage. The EPCS employs at least one temperature sensor to ensure optimum cell operating temperature. If the temperature falls outside of pre-set operational limits heating or cooling is applied as necessary. Additionally, if the heating or cooling system suffers a failure, the system will be shut down at predetermined high or low temperature limits.

The EPCS of the present invention, in one embodiment, can be normally connected to a human machine interface (wired or wireless HMI or user console) which consists of a standard LCD (liquid crystal display), or OLED (organic light emitting diode) display, or may utilise a wireless connection, such as Bluetooth®, connection to a tablet or mobile phone. Salient parameters such as the set current in amps, the cell temperature and heating or cooling status may be displayed as required. Options are provided to allow the user to set the cell current within pre-set limits, determined and set at the time of installation. The HMI can also indicate alarms and the status of the safety interlocks.

Heating and cooling system

The heating and cooling system of the present invention comprises of a circulation pump and a passive or fan assisted heat exchanger for cooling with an optional resistive heater pad for heating. The water in the system is circulated by a pump through the cell and into the heat exchanger. A‘water block’ with one or more Peltier elements attached may also be used to provide heating and cooling in a more compact form. A water block with a suitably sized heatsink to allow for totally passive, naturally convective air cooling, thus requiring no electrical input or mechanical devices to or effect or assist cooling, ie, no fans or Peltier devices may be used in the alterative or in combination with the active system

The EPCS of the present invention utilises a temperature sensor attached to the PEMEC in order to monitor its temperature to determine when cooling or heating is required. The circulation pump is normally running at all times clearing the cell of gas and circulating the water through the heat exchanger and/or water block. The fan if utilized, is only run when necessary to conserve power. Provision is also made to add other temperature sensors such as may be required for ambient temperature monitoring, engine bay temperature monitoring and the like.

Heat exchanger and Peltier elements

In one embodiment of the present invention the heat exchanger may consist of a coil of tubing affixed to a large fan. Water is circulated through the tubing and the fan passes air over the tubing, which provides adequate and cost effective cooling. More sophistication and a reduction in size and weight can be afforded by the use of a smaller radiator and fan which can also use considerably less power for the same cooling effect.

Heating in cooler climates may be necessary to prevent the water in the system from freezing. Serious damage to the PEMEC and other system components could occur if the water freezes. In these circumstances, the EPCS may employ an ambient temperature sensor to determine the ambient temperature and activate a heater pad on the supply tank along with the circulation pump to keep the water just above freezing point.

In other embodiments of the present invention, optionally or additionally, Peltier elements may be employed along with a‘water block’ to effect heating and cooling of the system in a more compact format. This option could make use of passive fins or radiators rather than a fan cooled radiator or heat exchanger.

Pump circulation monitor

The pump of the present invention uses a motional feedback element that allows monitoring of the pump speed. The EPCS is then able to monitor the motional feedback element and determine if the pump is operating at the correct speed; or is running too fast due to lack of water circulation due to cavitation as a result of a blockage, or from a lack of water; or is running too slow or stopped due to mechanical or electrical failure. In the event of a circulation pump failure, the EPCS can stop current delivery to the PEMEC to prevent overheating. An alarm may also be raised on the operator console. In the event of a minor circulation issue, an alert will be raised on the operator console warning of the problem.

Tank water level sensor

There are a number of options for measuring the level of PEMEC feed water stored in the tank, such as using a multi-level float switch, or a pressure sensor that can sense the full range of levels continuously from full to empty. Using a pressure sensor allows the EPCS to calculate a rate of consumption and remaining run time before the water supply reaches a pre-set alarm limit. Additionally, the water level is displayed on the user console. Additionally, the scale and range of the sensor can be programmed in firmware to accommodate different tank sizes.

The water level sensor is monitored by the EPCS to provide feedback of tank levels to the user via the HMI. Should the water level fall below a predetermined critical level, the EPCS can shut down the current to the PEMEC in order to prevent using up the water completely. This prevents damage to the pump, preventing it from being run dry, and ensures that the PEMEC membrane is always kept damp, preventing damage to the PEMEC.

Optional water replenishment system

Refilling the water supply tank can become tedious and inconvenient in applications where water consumption is high. In some embodiments, the present invention can use a facility to automatically refill the working water tank from a larger supply of water, such as an auxiliary tank or bladder, is incorporated into the EPCS. Either gravity feed or a pump may be utilised to transfer water and either a solenoid valve or pump can be installed to accommodate what is required. The EPCS allows entry of the capacity of the bulk water supply and the refill method. At each automatic refill, the EPCS calculates the remaining quantity of water in the bulk supply, based on data gathered from the water level sensor in the supply tank. PEMEC gas volume regulation

The EPCS provides continuous control of the PEMEC current from 0.0 amps to 35.0 amps. In doing so the volume of hydrogen delivered to the engine can be easily and continuously controlled. The EPCS allows connection of such signals as an idle sensor, throttle position sensor, engine rpm sensor, temperature sensors and other sensor devices.

The idle sensor is used to cut hydrogen gas production in those cases where the injection of hydrogen may cause an increase in NOx emissions. The throttle position sensor in conjunction with the engine RPM and where available, turbo boost pressure sensors can be used to compute the engine power output and can subsequently be used to modulate the amount of hydrogen gas generated to suite the current load on the engine in order to optimise fuel savings and emissions reductions.

Additionally, more advanced functionality can include connection to the engine control unit and the emissions control unit via a CAN (controller area network) bus or ODB (on board diagnostic) port for additional intelligent control of hydrogen gas production. Sensors may also be added to the exhaust to measure NOx and these can also be fed into the EPCS for precise control of NOx emissions reduction.

Human Machine Interface (HMI)

The Human Machine Interface (HMI), used in certain embodiments of the present invention, can take the form of a simple LCD text display or similar, or utilise a wireless connection such as Bluetooth® or WiFi connection to a tablet, PC, laptop or

smartphone. The HMI normally displays operational parameters and alarms events and may allow the user to make some adjustments to the system but is dependent on their preset user access level. The latter can be approached from a multi-level perspective, where users must enter a PIN number to access certain features.

A PC or tablet application will provide installers with the ability to set up the system, edit parameters, access a performance and fault logs and setup other users. The EPCS has the ability to log operational parameters, the storage period being dependent on the installed flash memory.

Applications can be made available for tablets, laptops and smartphones. In addition, colour coded status lamps can be also be provided on the main unit and at other locations on a vehicle, so as to provide a quick reference indication of the status of the system.

Hydrogen Gas Metering System

The gas delivery and metering system will employ a control algorithm within the EPCS that can control and modulate the gas flow utilising proportional electronically controlled valves. These valves allow independent metering (flow control) of hydrogen gas to the engine air intake and SCR systems. This control can be effected either in ‘open loop’ mode, where a fixed table of values is stored within the EPCS, or in‘closed loop’ mode, where for example, an on-line real time NOx sensor can be utilised to constantly adjust hydrogen gas flow to the SCR system, to effect optimal NOx emissions reduction.

Additional sensors can be added to EPCS to measure Oxygen and CO levels to effect even better/fmer control over emissions.

Oxygen produced by the system can optionally be fed into the intake manifold if required and furthermore this oxygen may be metered to other parts of the engine system.

Where there is a high degree of suction in the engine air intake system, the hydrogen delivery system under the control of the EPCS, can maintain a positive pressure in order to prevent the possibility of water suction into the intake system of the engine.

In one form of the present invention there is a system (5) is described with reference to the diagram of Figure 1. A conventional combustion engine (10) which includes an electronic process control system (EPCS) (15) connected by sensors to the engine (10) with air intake (18) and exhaust (20) and combustion fuel tank (25). The electronic process control system unit (15) includes a number of sensors to sense the operating parameters of the combustion engine (10), including, but not limited to oil pressure sensor, battery condition sensor, engine RMP sensor, engine temperature, NO_x exhaust sensor, and other appropriate sensors. The sensors are connected to the EPCS unit (15) in accordance with manufacturing requirements, and these would be well understood by those skilled in the art. The signals from the sensors are directed and fed into the EPCS control unit (15) as shown in Figure 2. The battery and oil pressure sensors (50) and (52), for example, are sent via digital signal (54) to the main processor (60), for example an ARM CORTEX M4 CPET. Power from the battery (70) is then conditioned and regulated by the component (75), and fed directly to the main processor (60) via connection (78).

Connection (79) and (80) can optionally be connected to other voltage buses. The battery (70) also provides power to the buck boost regulator (90), the buck boost regulator being a synchronous DC-DC converter, which measures parameters such as input voltage, output voltage, output current and internal temperature, said information then being fed by connection line (91) to the main processor (60). The buck boost regulator (90) is also operatively connected to an electrolysis cell (95), such as a proton exchange membrane electrolysis cell (PEMEC).

An analogue input converter (100) is connected via sensors to measure throttle position, sensor (105), NO_x sensor (110), connected to a location on the exhaust (20), temperature sensor (120) and line pressure sensor (130). A water tank (140), having temperature sensor (151) and pressure sensor (152), fluidly connected to the electrolytic cell (95), can provide signals to the analogue input converter (100), which can then be passed through to the main processor (60).

The main processor (60) has storage (160), such as flash memory or other electronically erasable programmable read-only memory (EEPROM) integrated therein. Information processed or needed by the main processor (60) may be accessible by connection to the controller area network (CAN) bus (161). Output drivers (190) may also be connected to the main processor (60) and can include driving a plurality of elements (191) associated with or operatively connected to the electrolytic cell (95) such as a fan (192), water pump (193), heater pad (194), proportional valves (195) or a replenishment pump (196). The processor (60) is operatively connected to a wireless transmitting unit (200) capable of emitting signals readable by a remote device (210) which forms part of the human machine interface to allow access to the system (15) so as to observe operating parameters and, as required, manipulate PEMEC operating parameters to achieve the desired hydrogen output.

The electrolysis cell (95) receives power from the module (250), as shown in Figure 3. The module (250) can be integrated within it the EPCS unit (15). Power for the electrolysis cell (95) is provided along line (91), the module (250) receiving power via the battery (255) which is also in connection with an oil pressure safety switch (260). The sensing unit (270) includes sensors monitoring the combustion engine such as battery condition, oil pressure, combustion engine rpm, which includes sensors (50), (52), (53) as shown in Figure 1. The information from the sensing unit (270) forms part of the engine operating parameters and is fed via line (271) into the hydrogen cell unit control module (280), which conditions and controls signals to the heating system, cooling system, pumping system, water level system and temperature system. A water level CPET board (281) is connected to the hydrogen cell unit control module (280) and the module (250) to communicate signals thereto. The hydrogen cell unit control module (280) may be incorporated within the EPCS unit (15) or located as a separate unit.

The hydrogen cell unit control module provides power to a water pump (300) via line (301), the water pump (300) being operatively fluidly connected to a distilled water supply and separator tank (320). The water separator tank 320) has temperature sensor (321) and pressure sensor (322) which sends signals via line (323) and (324) respectively to the hydrogen cell unit control module (280). The water supply (320) is fluidly connected to the water pump (300) by conduit (350) and the water pump (300) then directs water by conduit, or other suitable fluid connection, (355) to a water temperature control unit (360), such as a Peltier device, or heat exchanger so as to alter the temperature of the water passing through it to a desired temperature. Water is then passed by conduit (385) to the cell (95) such as a PEM electrolysis cell where the water is split (dissociated) into hydrogen gas and oxygen gas. Hydrogen gas can be fed out by conduit (400) to the distilled water supply and separator tank (320). Water/oxygen remaining from the electrolysis reaction can then be fed by conduit (410) back into the tank (320). Hydrogen gas and oxygen gases may be separated within the tank unit (320), oxygen gas being directed out through conduit (420) and hydrogen gas being directed out through the conduit (430) and is directed to the air intake (18) of the combustion engine (10) by way of supply line (440), then control valve (445) controlling the flow thereof. Hydrogen gas is also directed along conduit (450) towards the SCR (selective catalytic reduction system or converter) (451) by supply line (460), which is fed into the exhaust stream in the exhaust system (20) the flow of which is controlled by valve (455). By utilising the present invention then hydrogen gas is directed into both the combustion engine intake system which increases fuel burning efficiency due to higher flame speed of the burning hydrogen and injection of hydrogen into the SCR enables the operation of the SCR converter so as to reduce the NO_x emissions.

The present invention therefore provides a novel system that:

• reduces engine emissions such as particulate matter (pm) emitted from vehicles fitted with, but not limited to diesel engines;

• reduces engine emissions such as nitrous oxides, (NO and NO2) generally

referred to as NOx emitted from vehicles fitted with, but not limited to diesel engines;

• reduces fuel consumption of vehicles fitted with, but not limited to diesel

engines;

• improves engine, oil and exhaust system life by keeping these components

cleaner through hydrogen injection thereby reducing carbon deposits and soot production;

• replaces the need for diesel exhaust fluid (DEF - urea CH₄N₂O), such as

AdBlue®l, by generating hydrogen gas that is injected into the NOx emissions control system and catalytic converter in place of DEF

• allows the control and setting of operating parameters of a fuel conserving and emissions reduction system and provide a human machine interface (HMI) via conventional and/or wireless means. 1. A system when used for generating and providing hydrogen fuel on demand to a combustion engine.

2. The system of claim 1, wherein the system includes a method of controlling the delivery of the generated hydrogen fuel to the intake of the combustion engine.

3. The system of any one of the above claims, wherein the generation and

provision of hydrogen fuel is for use in a selective catalytic reduction system or converter (SCR).

4. The system of any one of the above claims, wherein the system includes an electrolysis cell for the generation of hydrogen.

Although the invention has been herein shown and described in what is conceived to be the most practical and preferred embodiment, it is recognized that departures can be made within the scope of the invention, which is not to be limited to the details described herein but it is to be accorded the full scope of the appended claims so as to embrace any and all equivalent devices and apparatus.

Claims

CLAIMS:

1. A system when used with a combustion engine, the combustion engine having an air intake, comprising:

a hydrogen cell unit including an electrolysis cell for converting water into hydrogen gas and oxygen gas, and at least fluidly connected to the combustion engine air intake;

a hydrogen cell unit control module operatively connected to the at least one hydrogen pressure monitoring sensor and to the electrolysis cell; said hydrogen cell unit control module operatively connected to a hydrogen gas delivery system, said hydrogen gas delivery system operable to control the delivery of hydrogen gas to the combustion engine air intake in response to predetermined signal levels from the hydrogen cell unit control module.

2. The system of claim 1, wherein the combustion engine includes a selective

catalytic reduction (SCR) system.

3. The system of claim 2, wherein the hydrogen cell unit is further fluidly connected to the selective catalytic reduction (SCR) system.

4. The system of claim 3, wherein the gas delivery system further includes operable to control the delivery of hydrogen gas to the combustion engine selective catalytic reduction (SCR) system.

5. The system of any one of the above claims 1-4, wherein the electrolysis cell is a proton exchange membrane (PEM) electrolysis cell.

6. The system of any one of the above claims, wherein the system generates

hydrogen via the electrolysis cell when the combustion engine is in operation. If the combustion engine is not in operation or stops operating (running) the system of generating hydrogen is disabled.

7. The system of any one of the above claims, wherein the system includes a relay switch device operatively connected between the electrolysis cell and the combustion engine.

8. The system of any one of the above claims, wherein the system includes single or a plurality of pressure monitoring devices to monitor the pressure of hydrogen generated and being supplied to the combustion engine, one of the pressure monitoring devices being operatively connected to activate a shut-off switch operatively connected to the electrolysis cell to disable the electrolysis cell at a predefined pressure.

9. The system of any one of the above claims, wherein the system includes a

pressure monitoring device to monitor the pressure of hydrogen generated and being supplied to the combustion engine, the pressure monitoring device being operatively connected to activate a metering valve to proportionally feed hydrogen to the engine air intake.

10. The system of any one of the above claims, wherein the system includes a

pressure monitoring device to monitor the pressure of hydrogen generated and being supplied to the combustion engine, the pressure monitoring device being operatively connected to activate a second metering valve to proportionally feed hydrogen to the selective catalytic reduction (SCR) system.

11. The system of any one of the above claims, wherein the predefined pressure in the first instance is an overpressure.

12. The system of any one of the above claims, wherein the pressure is monitored in real time to adjust the flow of hydrogen gas to the engine air intake and SCR system independently.

13. The system of any one of the above claims, wherein the system includes an

electronic process control system.

14. The system of any one of the above claims, wherein the electronic process control system has means for monitoring and controlling the temperature of the electrolytic cell.

15. The system of any one of the above claims, wherein the electronic process control system has means for setting and controlling a current flowing through the electrolytic cell.

16. The system of any one of the above claims, wherein the electronic process control system has means for metering or dispensing hydrogen gas produced by the electrolytic cell to the engine air intake.

17. The system of any one of the above claims, wherein the electronic process control system has means for metering or dispensing hydrogen gas produced by the electrolytic cell to the selective catalytic reduction system or converter.

18. The system of any one of the above claims, wherein the electronic process control system has means for metering or dispensing hydrogen gas produced by the electrolytic cell to the engine air intake and the selective catalytic reduction system or converter.

19. The system of any one of the above claims, wherein the electronic process control system includes means for monitoring NOx emissions.

20. The system of any one of the above claims, wherein the electronic process control system is adapted to adjust or control the flow of hydrogen produced from the electrolytic cell to the engine air intake and/or selective catalytic reduction system or converter.

21. The system of any one of the above claims, wherein the electronic process control system includes a plurality of engine parameter sensors, such as but not limited to idling sensors, throttle position sensor, energy rpm sensor, temperature sensors, and oil level sensors.

22. The system of any one of the above claims, wherein the electronic process control system includes at least one engine parameter sensor operatively connected to the electrolytic cell and at a predetermined threshold be at least one engine parameter sensor can modulate the amount of hydrogen gas generated by the electrolytic cell.

23. The system of any one of the above claims, wherein the electronic process control system has means to modulate the amount of hydrogen gas produced by the electrolytic cell in response to a predefined engine operation parameter.

24. The system of any one of the above claims, wherein the predefined engine

operation parameter is at least one of the parameters selected from the group consisting of or pressure, RPM, power output, torque, speed, fuel consumption, water purity and exhaust emission level.

25. The system of any one of the above claims, wherein the engine signals and

sensors may also be accessed by a connection to the vehicle CAN bus.

26. The system of claim 25, wherein the water purity is monitored by operationally connecting water purity monitoring sensors to enable the gas generation to be shut down to prevent PEMEC and system damage.

27. The system of any of the above claims that employs a gyroscopic or accelerometer sensor or both to affect a shutdown of the system in the event of a vehicle rollover of similar event to prevent inadvertent release of hydrogen.