From: Michael M. Butler (mmb@spies.com)
Date: Thu Jun 05 2003 - 16:28:38 MDT
40% efficiency is interesting if true. I wonder how noisy it is...
> A new design for an engine has
> a quintessentially British origin
>
>
> Jun 5th 2003
>> From The Economist print edition
>
> http://www.economist.com/science/displayStory.cfm?story_id=1826051
>
>
>
> ENGINES have been spluttering along in more or less the same way for
> decades. Most motor vehicles still rely on one of two sorts of piston-
> based
> internal combustion engine, both conceived over 100 years ago (by
> Nikolaus
> Otto and Rudolf Diesel). Turbine engines are similarly ancient. Even one
> of
> the more recent innovations, the pulsed jet engine, which injects gobbets
> of
> fuel into a combustion chamber to create intermittent pulses of power,
> made
> its debut as far back as the second world war. It formed the motor of the
> V1
> flying bombs launched by Germany against Britain.
>
> Now, a father-and-son team of inventors from Suffolk, in Britain, hopes
> to
> revolutionise engine technology with a new design for an ultra-efficient
> engine. John and Laurie Archer have been spending their spare time hidden
> away, in true British inventors' tradition, in a shed at the bottom of
> the
> garden. There, they have designed a motor that can run on natural gas,
> methane from landfills, or hydrogen.
>
> After ten years of hard work, a prototype made in part from a child's
> construction kit, and many patent applications, they have licensed their
> design to a Dutch technology group called ICCU Holdings. ICCU is putting
> together a consortium to develop the engine, and plans to use the
> Archers'
> design to build generators that will provide clean, green power units for
> housing estates.
>
> All engines work on the principle of burning fuel in a confined space and
> using the resulting rise in pressure to generate mechanical energy. In an
> Otto or Diesel engine, large losses of energy arise from incomplete
> combustion of the fuel. Further waste comes from losses to friction and
> noise as the pistons are driven up and down. As a result, the average car
> engine burns four times more fuel than it would need to move the vehicle
> were it as efficient as the laws of thermodynamics permit. By contrast,
> turbine engines, such as those used in aircraft, waste only about one-
> third
> of the fuel they burn. They do so because rotation is smoother than the
> up-and-down motion of pistons, and also because they are able to suck in
> vast amounts of air and thus burn the fuel with a lot of oxygen, which
> means
> that combustion is more or less complete.
>
> The ³Archer-Trice² engine, as it is known, combines pulse jets with
> turbines. John Archer describes the engine as looking like a propeller in
> a
> doughnut. In the Archer-Trice engine, gaseous fuel is fed into a
> cylinder,
> which then rotates to compress the space in which the gas is held. The
> design of the rotor gives the air intake a large ³swept volume²‹in other
> words, a vast amount of air is sucked in, even though the engine itself
> is
> stationary. A sparking plug ignites the gas, providing the pulse which
> produces power to turn the cylinder. The compressed burning gas is
> released
> through the exhaust.
>
> Water is injected into the system to produce steam, providing a way of
> cooling the engine (which, in a moving machine, is another of the
> services
> provided by the airstream). And the engine is computer-controlled to
> ensure
> that all the stages are timed to perfection and that it operates at
> maximum
> efficiency. Currently, the engine is around 40% efficient, and the
> Archers
> hope to improve on this.
>
> John and Laurie Archer are both electrical engineers, and have always
> been
> interested in how engines work. But their decision to try to design their
> own engine came after they built a D-type Jaguar car together in the
> 1980s.
> ³We realised that the car engine was hugely inefficient and thought we
> could
> try to make something better,² says John Archer.
>
> What may once have seemed like a crazy idea is now being taken seriously.
> At
> the moment, the Netherlands imports much of its electricity from
> neighbouring countries, meaning that a significant amount of energy is
> wasted in transmission. ICCU is keen to develop a more efficient and
> environmentally friendly power supply, and the Archer-Trice engine could
> provide a solution.
>
> The firm is investing several million euros in the project, and within
> nine
> months it hopes to use the Archer-Trice design to produce an efficient,
> natural-gas-fuelled generator capable of powering 1,000 homes. As a
> bonus,
> the steam from the cooling system can be used to heat the homes, instead
> of
> being wasted. If all goes to plan, ICCU will be able to set up a network
> of
> local generators that will reduce reliance on large power stations. They
> may
> even be able to sell surplus power back to the national grid.
>
> In the meantime, John and Laurie Archer are still refining their engine
> design and waiting for the day when Archer-Trice engines are taken up by
> the
> car industry. That may be a while coming. But you never know. Perhaps in
> another 100 years the name ³Archer² will stand alongside those of Otto
> and
> Diesel in the history books and maintenance manuals.
-- I am not here to have an argument. I am here as part of a civilization. Sometimes I forget.
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