How It Works

HHO: The Technology – how it works

Hydrogen has 3 times the energy density of petroleum fuels and is a clean burning fuel.  Its use in vehicles can dramatically help improve air quality especially in city environments.  Transport accounts for around 27% of the UK’s CO2 emissions with road transport accounting for around 70% of those emissions.  Regardless of the production pathway, hydrogen is emissions free at the point of use.

The Fuel Cell Hydrogen Unit (FCHU) is possibly the most exciting product to come on to the automotive market in many years.  It offers improved power, reduced fuel costs and lower emissions.  It is based on a very simple concept.  For many years people have been trying to introduce hydrogen into automotive engines without any meaningful success.  This has now changed.

The FCHU is a small unit that is fitted to the vehicle and when an electric current flows, it produces a gas from water.  This is a process known as electrolysis.  The effect of this current on the water is to produce a hydrogen and oxygen gas (HHO) which is then introduced into the engine where it mixes with the fossil fuel and air as a fuel supplement.  Petrol and diesel engines use only around 15-20% of the embedded energy in the fuel.   HHO increases the efficiency of the engine.  The by-product of the hydrogen-oxygen reaction is water which is produced in the form of steam.

Fuel is made of “Hydrocarbon Chains”. The chains look something like this:

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H H H H H H H

H C C C C C C C H

H H H H H H H

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Where the “H” is the Hydrogen atom and the “C” is Carbon.

Fuel carbon chains are usually C7H16 through to C11H24.   C7H16 means 7 carbon atoms with 16 hydrogen atoms. Heavier chains like C14H30 are used as diesel fuel.  Carbon chains above C20 are tars and heavy oils.  The lightest chain is CH4, methane.  We burn the mixture somewhere around C9H20 in our internal combustion engines. Chains of this weight are used as fuel because they are in a liquid state at normal temperatures, easy to store and transport.  They also vaporise easily.  In order to burn the fuel it must be transported from the tank to the combustion chamber.  There the fuel is mixed with air from the air intake, vaporised, compressed, and ignited. This process takes place very quickly and continuously to maintain the cycle of the internal combustion engine.  To make a point, we are already burning hydrogen and oxygen in internal combustion engines. The difference between this and pure HHO gas is the carbon atom.  The carbon that is left behind is what causes engine sludge, deposits and carbon build up, poor performance, and pollution.

The enrichment of the gasoline is not realised through chemical or mechanical “doping” of the fuel, but with direct injection of hydrogen gas at the air intake in the vicinity of the inlet valve.  In the typical combustion engine, the spark plug creates the ignition spark and the combustion begins 4° before TDC.  The hydrogen enriched fuel has already entered the combustion chamber and the fuel-air ratio is very small (lean mixture) in order to achieve high efficiency.  Just 2msec later, the hydrogen starts to ignite and because of the fact that it is under high temperature and pressure it starts to separate into atomic (nascent) hydrogen. Nascent hydrogen is very active and produces a rapid chain reaction that spreads almost instantly to the whole combustion chamber volume. The almost simultaneous ignition of hydrogen initiates the simultaneous ignition of the main fuel, which is burned instantly without creating any flame front since the whole combustion chamber is being ignited at the same time. The combustion process is now completed about 6-10msec later and after the piston has moved only 14-18° after TDC. This rapid combustion phenomenon results in:

  • Complete combustion of the whole chamber’s volume without un-ignited areas.
  • Development of very high pressures at the combustion chamber due to the high temperatures and due to the fact that the combustion chamber volume is not significantly increased (the piston moves less than 20°). This leads to increased piston forces and increased engine torque (around 30% increase).
  • Ability to combust effectively extra-lean air-fuel mixture, which would not ignite in conventional combustion engines. This leads to higher efficiency and increased fuel economy (around 25-30%).
  • Reduce (or even eliminate) CO and unburned HC emissions due to almost perfect combustion.
  • Reduction of NOx emissions, due to a complex mechanism of combustion mechanics.