Water Injection Improves Efficiency

[EdEarl]

 

Phys.org: Bosch engineers turn to water injection for fuel-saving bonus

 

The big deal is that it can help support fuel economy. "WaterBoost uses the cooling effect of water to help gasoline direct injection systems place more and cooler intake air into the combustion chamber." This makes combustion particularly efficient, said the presenter, and "delivers an extra kick when accelerating."

 

up to 13% lower fuel consumption

 

Evan Ackerman in IEEE Spectrum said, "you'll have to remember to fill up a tank with distilled water. However, this isn't as big of a deal as it probably sounds, because the system uses only a few milliliters per kilometer, meaning that one full tank of water will last 3,000 km or so. And if you forget to fill the tank up for a while, the worst that can happen is that you lose the benefits that WaterBoost offers until you put some water into it again."

I wonder what improvement is typical.

 

Ironically, this technology has appeared as gasoline engines are being replaced by electric motors.

 

[DrKrettin]

This issue turns up at regular intervals. About 30 years ago, I was involved in a company set up by an acquaintance. He had an invention which claimed to save around 10% on fuel costs in cars with petrol engines. The basic principle was to inject water vapour into the engine along with petrol. It was even featured on BBC TV on a prestigious program about advances in science, whose name I forget. A lot of research went into this because the financial significance was huge. It transpired that there was no measurable advantage in doing this, and the company failed. But the idea keeps turning up. Maybe this time it is different.

[MigL]

No, the effect has been well known for years.

It was used in internal combustion ( piston ) engines of WW2 fighter planes and even some 60s vintage jet planes, where it has an even more substantial effect.

The disadvantage is that you could, instead of carrying water with you, carry a much smaller amount of extra fuel, and then use super/turbo charging of the air to enable its use.

You would need to add a large amount of water to cool the intake charge enough to be able to stuff twice the amount of air into a combustion chamber while turbochargers do it routinely.

 

Edit: Search for Water Injection ( engine ) on Wikipedia.

Edited September 2, 2016 by MigL