Description

PRODUCTION OF HYDROGEN FOR ADDITION TO THE INTAKE AIR OF AN LC. ENGINE

Technical Field

[1] This invention relates to the production of hydrogen for addition to intake air of an internal combustion engine. Background Art

[2] It is known that if hydrogen is added in small proportion to the intake air of an internal combustion engine, such as a Diesel engine, the engine runs cleaner, with more power and less emissions. However, hydrogen is expensive to produce, costly to distribute and dangerous to carry on a motor vehicle. To deal with these problems, it is known to produce hydrogen from water by electrolysis as required on a motor vehicle. An example of such a system is sold under the trade mark Hy-Drive by Hy-Drive Technologies Ltd., Canada , L5H 5M4. Despite the energy required to be produced by the engine in order to generate the electricity required by the electrolysis process, the engine still produces more net power.

[3] An example of the Hy-Drive system 10 fitted to a vehicle's Diesel engine 12 is shown schematically in Figure 1 of the accompanying drawings. An electrolysis unit 14 is supplied with electricity from the engine-driven alternator 16 and with water from a water tank 18 to produce hydrogen and oxygen, both of which are added to air drawn into the engine's inlet manifold 20. As is conventional, the engine also has a fuel tank 22 and an engine-driven injection pump 24. In operation, the engine 12 consumes fuel from the fuel tank 22, water from the water tank 18 and air from the atmosphere to produce useful net output mechanical power 26 for driving the vehicle, some useful net electrical power 28 for driving electrical circuits of the vehicle, wasted exhaust gas 30 and heat 32 most of which is wasted, but some of which may be used for example to heat the vehicle's interior. Disclosure of Invention

Technical Problem

[4] The water consumption of the engine 12 is small, typically one litre per 3000 kilometres. However, the water that is used needs to be pure water, so as not to damage the electrolysis unit 14. The need to use pure water, which is not readily available, is an inconvenience, and there is a risk that somebody will use impure water, such as tap water, and damage the electrolysis unit.

[5] The present invention, or at least specific embodiments of it, is concerned with this problem.

Technical Solution

[6] In accordance with a first aspect of the present invention, there is provided a method of production of hydrogen for addition to intake air of an internal combustion engine, the method comprising the steps of: providing a supply of water that is not necessarily pure; using energy from the engine to evaporate water from the supply to produce water vapour; condensing the water vapour to produce distilled water; and electrolysing the distilled water to produce hydrogen and oxygen. The need for distilled water is therefore obviated.

[7] The energy from the engine that is used to evaporate the water is preferably heat, which, of course, might otherwise be wasted. Also, the method can assist in cooling the engine and therefore further improve its operation.

[8] The method may further include the step of accumulating the distilled water ready for the electrolysing step, for example so that there is an available supply of the distilled water when the engine is started.

[9] The method may further include the step of recirculating excess distilled water back to the water supply. The rate of evaporation of the water does not therefore need to be controlled.

[10] The water supply may be contained in a reservoir, and the method preferably further includes the step of periodically replenishing the reservoir with water that is not necessarily pure, so that it does not run out.

[11] The evaporation step may be performed in an evaporator, and the method preferably further includes the step of periodically cleaning or replacing the evaporator to avoid an excessive build up of residues such as limescale.

[12] In accordance with a second aspect of the present invention, there is provided a method of operation of an internal combustion engine, including: the method of the first aspect of the invention; and the step of adding the hydrogen and oxygen to air that is to be drawn into the engine.

[13] In accordance with a third aspect of the present invention, there is provided an apparatus for the production of hydrogen for addition to intake air of an internal combustion engine, comprising: a reservoir for water that is not necessarily pure; an evaporator arranged to receive water from the reservoir and for receiving energy from the engine in order to evaporate the water to produce water vapour; a condenser arranged to receive the water vapour from the evaporator and to condense the water vapour to produce distilled water; and an electrolyser arranged to receive distilled water from the condenser and to electrolyse the distilled water to produce hydrogen and oxygen.

[14] The apparatus preferably further includes a second reservoir for accumulating the

distilled water ready for supply to the electrolyser.

[15] The first- mentioned reservoir is preferably arranged to receive excess distilled water produced by the condenser.

[16] In accordance with a fourth aspect of the present invention, there is provided an internal combustion engine having an apparatus of the third aspect of the invention.

[17] The evaporator is preferably arranged to receive heat from the engine.

[18] The evaporator is preferably releasably connected with respect to the engine.

Brief Description of the Drawings

[19] A specific embodiment of the present invention will now be described, purely by way of example, with reference to Figure 2 the accompanying drawings, in which:

[20] Figure 1 is a schematic diagram of a Diesel engine fitted with a Hy-Drive system as described above; and

[21] Figure 2 is similar to Figure 1, but modified in accordance with the embodiment of the invention. Best Mode for Carrying Out the Invention

[22] Referring to Figure 2 by comparison to Figure 1, a water tank 34 is included which can be topped-up with tap-water. The tap-water tank 34 feeds water to an evaporator 36, which is removably mounted on part of the engine 12 which becomes hot when the engine is running. For example, the evaporator 36 may be removably mounted on an exhaust system of the vehicle, downstream of a catalytic converter, if present. Alternatively, for example, the evaporator 36 may be removably mounted on the cylinder head of the engine 12. Water in the evaporator 36 evaporates to form water vapour which passes to a condenser 38, and residue 40 from the tap-water remains in the evaporator 36. The condenser 38 is preferably mounted in an air-flow, for example in front of a radiator fan of the vehicle, or in a take-off from a radiator grille of the vehicle. Heat is given off by the condenser 38 and the water vapour condenses to form distilled water. The distilled water is supplied to the distilled water tank 18 of the Hy- Drive system 10. The Hy-Drive system 10 operates in its known manner, except that there is no need to top it up manually with distilled water, and indeed the distilled water tank 18 may be modified to prevent it being topped-up manually.

[23] The evaporator 36 and condenser 38 are designed such that they can produce enough distilled water for the Hy-Drive system's maximum consumption. When it is using less, excess distilled water can be recirculated back to the tap-water tank 34.

[24] The movement of water and water vapour around the system may be caused by gravity, relative densities, check valve(s) and/or pump(s).

[25] Periodically, the tap-water tank 34 will need to be replenished with tap-water, and the evaporator 36 will need to be cleaned of residue or removed and replaced.

[26] Although the embodiment of the invention has been described in relation to the known Hy-Drive system, it will be appreciated that it may also be applied to another electrolytic hydrogen generators.

[27] The tap water tank 34 may be shared with other water-consuming systems of the vehicle, for example a windscreen washer system. In this case, it will be appreciated that any windscreen washing detergent or the like should not be added to the tap water tank 34, but instead added to the windscreen washing water later, for example downstream of the windscreen washer pump.

[28] It should be noted that the embodiment of the invention has been described above purely by way of example and that many modifications and developments may be made thereto within the scope of the present invention.