WO2014028951A1

WO2014028951A1 - Apparatus and method for hydrogen enrichment

Info

Publication number: WO2014028951A1
Application number: PCT/ZA2013/000066
Authority: WO
Inventors: Gert Cornelis ERASMUS
Original assignee: Erasmus Gert Cornelis
Priority date: 2012-08-14
Filing date: 2013-08-14
Publication date: 2014-02-20
Also published as: ZA201206077B

Abstract

In the present invention, there is provided an apparatus for hydrogen enrichment comprising a power supply unit, an electronic filter and a reactor for dissociating water into a hydrogen and oxygen gas mixture via an electrolytic process, the reactor being described as a variable resistance load and the power supply being capable of providing a constant current for the variable resistance load.

Description

TITLE OF INVENTION: APPARATUS AND METHOD FOR HYDROGEN ENRICHMENT

INTRODUCTION

This invention relates to an apparatus for hydrogen enrichment. More particularly, this invention relates to an apparatus for hydrogen enrichment of fuel for internal combustion engines by an electrolytic produced hydrogen oxygen gas mixture. Furthermore this invention relates to method for hydrogen enrichment of fuel for internal combustion engines, a power supply for an apparatus for hydrogen enrichment and a method of operating a power supply for an apparatus for hydrogen enrichment.

BACKGROUND TO THE INVENTION

It has been recognized for many years that the use of hydrogen gas as a fuel additive in addition to petroleum base fuels offers distinct advantages for the operation of internal combustion engines. For example, the hydrogen gas as a fuel additive enhances fuel efficiency of petroleum based fuel. Furthermore, by adding a small amount of hydrogen gas to the air intake of the internal combustion engine allows to operate the engine with a leaner air-to-fuel mixture which in turn substantially reduces the temperature of combustion and effectively mitigates production of nitrogen oxide compounds. In addition, production of carbon monoxide and/or carbon dioxide can be reduced.

The required amount of hydrogen gas which should be added to the air intake is relatively small. Accordingly, it is possible to produce the required hydrogen gas on board of a car or a truck by an electrolytic process. The electrolytic process can be operated from the on-board electric system which is charged by an electric generator via the engine. Accordingly, hazardous storage elements for hydrogen such as pressure tanks can be avoided. A problem associated with known prior art apparatus for hydrogen enrichment is that the electrolytic process for producing the hydrogen needs to be controlled over a huge temperature range. Occasionally, run-away of the operating point is experienced which leads to unwanted working conditions of the apparatus for hydrogen enrichment.

What is ideally required is an apparatus for hydrogen enrichment which not only offers an improved source of energy or fuel, but also one which is easier and more stable to operate.

OBJECTS OF THE INVENTION

It is an object of the present invention to provide an apparatus for hydrogen enrichment, a method for hydrogen enrichment of fuel for internal combustion engines, a power supply for an apparatus for hydrogen enrichment and a method of operating a power supply for an apparatus for hydrogen enrichment which overcomes, at least partly, the disadvantages associated with existing apparatus for hydrogen enrichment.

It is also an object of the present invention to provide an apparatus for hydrogen enrichment, a method for hydrogen enrichment of fuel for internal combustion engines, a power supply for an apparatus for hydrogen enrichment and a method of operating a power supply for an apparatus for hydrogen enrichment which are both novel and involve an inventive step.

SUMMARY OF THE INVENTION

According to one aspect of the present invention, there is provided an apparatus for hydrogen enrichment comprising a power supply unit, an electronic filter and a reactor for dissociating water into a hydrogen and oxygen gas mixture via an electrolytic process, the reactor being described as a variable resistance load and the power supply being capable of providing a constant current for the variable resistance load. It is to be appreciated that the hydrogen and oxygen gas mixture produced in the reactor can be added to the air intake of an internal combustion engine of a car or a truck.

The reactor may include an anode and a cathode, the cathode being formed by an outer hull of the reactor.

The outer hull may be fabricated from conductive stainless steel.

The power supply unit may include input ports which are connected to a battery of a vehicle. The battery may provide 'vehicle power' which includes 6 V, 12 V and 24 V systems. The power supply unit can be connected to motorbikes (6 V), cars (12 V), or trucks (24 V).

It is to be appreciated that the input voltage is not fixed to those values. For other applications generators that generate 220V AC might be present.

The power supply unit may include a power transistor.

The power transistor may be a plurality of MOSFETs being connected in parallel.

The power transistor may be coupled to a pulse width modulator circuit.

The pulse width modulator circuit may be capable of generating square wave pulses. The width of the square wave pulses may be controlled by pulse width modulator circuit and may be directly proportional to the output power required. A voltage sensing circuit may be part of the pulse width modulator circuit. A temperature sensing input may be part of the pulse width modulator circuit in order to monitor transistor temperature.

A voltage feedback may be part of the pulse width modulator circuit in order to limit maximum output voltage.

The filter circuit may include an inductor and a capacitor. The filter circuit may be a low pass filter. The filter circuit may comprise a free-wheeling diode.

According to a second aspect of the present invention, there is provided a method for hydrogen enrichment of fuel for internal combustion engines comprising the steps of providing a power supply unit, an electronic filter and a reactor for dissociating water into a hydrogen and oxygen gas mixture via an electrolytic process, wherein the reactor being described as a variable resistance load and the power supply being capable of providing a constant current for the variable resistance load.

The power supply unit may include a pulse width modulator circuit capable of switching power from the main power to the filter circuit. When the maximum current is reached a power transistor may be switched off.

A voltage detector may sense a voltage generated over the power transistor.

An increased temperature may be counteracted via reduced pulse width. According to third aspect of the present invention, there is provided a power supply for an apparatus for hydrogen enrichment. According to fourth aspect of the present invention, there is provided a method of operating a power supply for an apparatus for hydrogen enrichment.

DETAILED DESCRIPTION OF THE INVENTION The invention will now be described in greater detail by way of example with reference to the following drawing in which:

Figure 1 shows a schematic view of an apparatus for hydrogen enrichment according to an embodiment of the present invention.

In Figure 1 an embodiment of the present invention is shown.

Before describing the individual parts and the operation of an apparatus for hydrogen enrichment in more detail, a short description of the overall system is given. As depicted in Figure 1 , the apparatus for hydrogen enrichment 5 includes a power supply unit 10, a filter 20 and a reactor 30 for dissociating water into a hydrogen and oxygen gas mixture via an electrolytic process. In the following, the hydrogen and oxygen gas mixture will be referred to as HHO. HHO produced in reactor 30 can be added to the air intake of the internal combustion engine of a car or a truck by the electrolytic process so as to provide the hydrogen enrichment of fuel for internal combustion engines.

The reactor includes an anode 32 and a cathode 34. The power supply unit 10 is connected via the filter 20 to the reactor 30. At the inner part, which is anode 32, a positive voltage can be applied. The outer hull forms the cathode 34 and can be connected to ground, i.e. to the 0 V potential. However, other configurations are conceivable as well. The outer hull can be fabricated from conductive stainless steel. Before operating the apparatus for hydrogen enrichment 5, at least water should be filled into the reactor 30. Suitable additives for distilled water can be sodium hydroxide, for example.

The HHO reactor 30 can be characterized as a variable resistor when operating. The resistance of the reactor 30 varies due to several factors. The surface area of the conductive stainless steel touching the water varies due to varying water level. An electrolyte, e.g. sodium hydroxide, can be added to the solution which influences the resistance. Other dissolved metals and salts change the resistance as well. The temperature of reactor 30 also has an influence on the resistance. The basic operation in the reactor 30 is defined by Faraday's electrolysis law which results in gas production of HHO proportional to the current flowing between the anode 32 and the cathode 34. For proper operation, the power supply unit 10 must thus produce a constant current for the reactor 30 to be stable as the effects described above in the reactor 30 causes a thermal and current run-away.

The power supply unit 10 is now described in more detail. The power supply unit 10 includes input ports 40 and 42 which are connected to a battery 43 of the car or the truck. The battery 43 can provide a voltage of 12 V or 24 V, for example.

The battery provides 'vehicle power' which includes 6 V, 12 V and 24 V systems. The power supply unit can be connected to motorbikes (6 V), cars (12 V), or trucks (24 V). It is however not intended to fix the input voltage and/or the output current to the specified values. It should be noted that for other applications generators that generate 220V AC might be present. For those a similar circuit is used, i.e. an AC-DC circuit, instead of the DC-DC circuit described above.

Input port 42 is connected as a ground line to the cathode 34 of the reactor 30. Furthermore, a power transistor 44 is present. In the example shown in Figure 1 , the power transistor 44 is an n-channel MOSFET. The power transistor 44 is preferably a bank of n-channel MOSFETs being connected in parallel so as to provide a higher output current. It should be noted that simple modifications can be applied to the depicted circuit without departing from the sprit of the invention. For example, is also conceivable to use a different type of transistor, to reverse polarity or the like.

The drain 46 terminal of the power transistor 44 is connected to the input port 40. The source terminal 48 is connected to the filter 20.

The gate terminal 50 is coupled to a pulse width modulator (PWM) circuit 52. The pulse width modulator (PWM) circuit 52 is capable of generating square wave pulses. The width of the square wave pulses is controlled by pulse width modulator (PWM) circuit 52 and is directly proportional to the output power required. A voltage sensing circuit 54 is part of the PWM circuit 52 being attached to the drain 46 terminal and the source terminal 48 of the power transistor 44. Furthermore, a temperature sensing input 56 is provided in order to monitor transistor temperature is included in the PWM circuit 52. A voltage feedback 58 to the PWM circuit 52 limits maximum output voltage at the filter 20 to the anode 32. The PWM circuit 52 generates a high frequency square wave output that drives the gate terminal 50 of the power transistor 44. This allows deterministic packets of energy to pass through the power transistor 44. The voltage sensing circuit 54, across the drain terminal 46 and source terminal 48 of the power transistor 44, measures the voltage generated when current passes the power transistor 44. As the power transistor 44 has a known On Resistance (RdsOn) the voltage will be directly proportional to the current passing the power transistor 44. By using Ohm's law (V= IR) the current I can be calculated by I = V1/RdsOn. Thus when the voltage sensing circuit 54 senses a voltage higher than the current limit the duty cycle on the PWM circuit 52 is reduced. It should be noted that if no filter circuit 20 is added, the current will flow un-apposed and the reduction of the duty cycle will not be enough to reduce the flow of the current.

The PWM circuit 52 also employs a temperature sensing circuit being connected to the temperature sensing input 56. As the temperature increases the duty cycle is also reduced resulting in less current flow at maximum possible current.

In addition, the PWM circuit 52 employs the voltage feedback 58 from the filter that sets the maximum output voltage that the power supply unit 10 can produce at no-load conditions.

The filter circuit 20, in the minimum condition, includes an inductor 60 and a capacitor 62.

T he series inductor 60 will appose high frequency pulses produced by the output of power transistor 44. At the same time the capacitor 62 will pass high frequency pulses to ground. Thus the filter circuit 20 is a low pass filter. As there are no resistors in this circuit heat losses are minimized. There are, however, parasitic resistances in both the inductor 60 and capacitor 62 that will result in heat generation. At the output V2 of filter circuit 20 the steady state voltage output that is applied to the reactor 30 is generated. In a practical filter circuit 20, a free-wheeling diode will also be added between the input side of the inductor 60 and ground, i.e. at 0 V.

The PWM circuit 52 effectively switches power from the main power to the filter circuit 20. When the maximum current is reached the power transistor 44, via the PWM circuit 52, is switched off. This is detected as a voltage generated over the power transistor 44. As a safety measure increased temperature is counteracted via reduced pulse width. In a low on non-loaded system the voltage is also limited via a voltage feedback from the filter. The high frequency pulses are filtered by a low pass filter 20 which results in a DC voltage produced at V2. The system obeys Ohm's law (V = IR). The resulting current I is directly proportional to V2 and R1 , i.e. the reactor resistance. As the resistance of the reactor 30 drops the PWM circuit 52 will maintain the current. As a result the voltage at V2 will obey Ohm's law and reduce as well.

As an example, the required rate for HHO production can be 4 ml per second. This requires a constant current of 15 A to 18 A between anode and cathode of reactor 30. It should be noted that referring to 15 A to 18 A should be considered as an example as the required current can be changed to produce gas for different size reactors. As already stated above, the current limit principle is employed in order to supply current for the reactor 30.

A suitable power transistor 44 can have an On Resistance (RdsOn) of approximately 200 mQ, for example. By using at least eight transistors in parallel, the current through each individual transistor can be limited to 2.5 A by keeping the voltage across source and drain at approximately 0.5 V. The PWM circuit 52 can be operated with a frequency of 250 kHz, for example. It should be noted however that the option of operating the PWM circuit 52 from 250 KHz to 4 MHz is also conceivable. The frequency chosen depends on how the circuit layout is, on the quality of components and many other factors.

It has been found by the inventor that the apparatus 5 described above has various advantages over existing ones. Firstly, by using the power supply unit 10, an efficient transformation of energy is achieved. Secondly, low heat generation for installation in a high ambient temperature environment is employed. Thirdly, constant current generation for the reactor is provided. The apparatus 5 therefore provides a stable and safe way of operating the reactor which results in a constant production of HHO without experiencing a run-away or the like.

Although certain embodiments only have been described herein, it will be readily apparent to any person skilled in the art that other modifications and/or variations of the invention are possible. Such modifications and/or variations are therefore to be considered as falling within the spirit and scope of the invention as herein described and/or exemplified.

Claims

1. An apparatus for hydrogen enrichment comprising:

a power supply unit, an electronic filter and a reactor for dissociating water into a hydrogen and oxygen gas mixture via an electrolytic process, the reactor being described as a variable resistance load and the power supply being capable of providing a constant current for the variable resistance load.

2. An apparatus as claimed in claim 1 wherein, the reactor includes and anode and a cathode, the cathode being formed by an outer hull of the reactor.

3. An apparatus as claimed in claim 2 wherein, the hull is fabricated from stainless steel.

4. An apparatus as claimed in claim 1 or claim 2 wherein, the power supply unit includes input ports which are connected to a battery of a vehicle.

5. An apparatus as claimed in claim 2 or claim 4 wherein, the power unit includes a power transistor.

6. An apparatus as claimed in claim 5 wherein, the power transistor is a plurality of MOSFETs being connected in parallel.

7. An apparatus as claimed in claim 6 wherein, the transistor may be coupled to a pulse width modulator circuit.

8. An apparatus as claimed in claim 7 wherein, the pulse width modulator circuit may be capable of generating square wave pulses.

9. An apparatus as claimed in claim 8 wherein, a width of the square wave pulses is controlled by a pulse width modulator circuit is directly proportional to the output power required.

10. An apparatus as claimed in claim 7 or claim 8 wherein, the pulse width modulator circuit includes a voltage sensing circuit.

11. An apparatus as claimed in claim 10, wherein temperature sensing input is part of the pulse width modulator circuit in order to monitor transistor temperature.

12. An apparatus as claimed in claim 9, wherein a voltage feedback is part of the pulse width modulator circuit, which feedback is configured to limit maximum output voltage.

13. An apparatus as claimed in any one of claims 1 to 13, which includes a filter circuit with an inductor and a capacitor.

14. An apparatus as claimed in claim 13 wherein, the filter circuit is a low pass filter.

15. An apparatus as claimed in claim 14 wherein, the filter circuit comprised a free-wheeling diode.

16. A method for hydrogen enrichment of fuel for internal combustion engines comprising the steps of providing a power supply unit, an electronic filter and a reactor for dissociating water into a hydrogen and oxygen gas mixture via an electrolytic process, wherein the reactor being described as a variable resistance load and the power supply being capable of providing a constant current for the variable resistance load.

17. A method as claimed in claim 16 wherein, the power supply unit includes a pulse width modulator circuit capable of switching power from the main power to the filter circuit.

18. An apparatus for hydrogen enrichment including any new and inventive integer or combination of integers, substantially as herein described.

19. A method for hydrogen enrichment including any new and inventive integer or combination of integers, substantially as herein described.