Hi Martin
>If it is in fact running hotter, you could use a water injection system
>to cool it down (and also increase efficiency a bit)
>..or can you not do this with a diesel as you can with a gasoline engine?
>-Martin Klingensmith
Yes you can. Here's a roundup below of some stuff we've had
previously and some other stuff, on both water injection and
water-fuel emulsions.
Only it changes rather from a heat question to a NOx and PM emissions
question. For instance: Water Addition - 1% NOx reduction for every
1% added water.
All biodiesel standards call for low water content (much lower than
its "natural" state of about 1200ppm), and most of us dry our fuel.
Meanwhile, with both biodiesel and dinodiesel, quite a lot of people
are trying to figure ways of getting MORE water into the fuel. See
this, for instance:
http://archive.nnytech.net/sgroup/BIOFUELS-BIZ/835/
This EPA doc, "Bibliography of Water-Fuel Emulsions Studies", lists
23 studies with diesels.
"Following is a list of studies that are being considered for
inclusion in work being done by EPA to assess the effects of
water-fuel emulsions on emissions of oxides of nitrogen (NOx),
hydrocarbons (HC), and particulate matter (PM)."
http://www.epa.gov/otaq/models/analysis/emulsion/emulbibl.pdf
Here's a later document:
Draft Technical Report, Impacts of Lubrizol's PuriNOx Water/Diesel
Emulsion on Exhaust Emissions from Heavy-Duty Engines
EPA420-P-02-007, December 2002) 1.2M PDF
http://www.epa.gov/otaq/models/p02007.pdf
And this:
>Workshop on Water Technologies for NOx Reduction
>
>This workshop brought together the most current efforts associated
>with water used for reducing diesel exhaust emissions. The purpose
>of the workshop was to discuss various water technologies for NOx
>reduction in medium- and heavy-duty diesel engines. In this workshop
>leading manufacturers, researchers and technology developers
>presented their work on water technologies reducing NOx emissions
>from mobile and stationary sources and discussed the effectiveness
>of this technology.
>
>Benefits
>
>1. Brought out factual, credible information on water technologies
>to illustrate the 50-70 percent NOx reduction, and 30 percent smoke
>reduction potential with fuel economy advantages with its use.
>
>2. Informed Air Resources Board and South Coast Air Quality
>Management District attending staff on the potential air quality
>benefits with this technology.
http://www.energy.ca.gov/afvs/clean_diesel.html
Re misting and water injection:
>I have not tried this, but have read about many good examples of it on the
>www.tdiclub.com where people talk about tuning VW turbodiesels. The primary
>reason I heard of in that circle was related to the turbo. The engine can be
>made more efficient if the charged air coming into it is cooler. The
>intercooler does cool down the intake air to some extent, but the amount of
>cooling possible with a mister into the air intake (post turbo) allows
>dramatic cooling of the intake charge, especially in parts of the country
>with dry air (desert and such). Most systems I have seen have been tied to
>the boost sensor to only inject water under high boost conditions (when the
>intake air is the hottest because of adiabatic compression in the turbo
>system.
>
>These are available at many hot rodding stores. Just do a web search on it.
>Hans Rosenberger
This from another post:
>Injecting water into a diesel engine or a internal combustion engine
>is not a new idea. High Performance Aircraft on both sides of the
>fence in WWII used water injection. The high performance Diesel
>engines used in tractor pulling and hybrid Diesel truck racing have
>water injected to boost power through the principles of latent heat
>of vaporization. Also water is sometimes injected after the
>combustion chamber to keep the turbo charger from melting into a pool
>of slag. Water was used by over-the-road large displacement truck
>engines in the days when horsepower was accomplished by massive over-
>fueling the combustion chamber. Technology and ecology has matured
>huge measures since then.
The following is from a paper I have here, long, detailed and
authoritative, but it's controlled-circulation so this is just the
top bit:
>Water in Diesel Combustion
>
>Abstract: Addition of water to the diesel process decreases
>combustion temperatures and lowers NOx emissions. The most common
>methods of introducing water are direct injection into the cylinder,
>a process commercialized in certain marine and stationary diesel
>engines, and water-in-fuel emulsions. Emulsified fuels, due to
>increased mixing in the diesel diffusion flame, can be also
>effective in simultaneous reduction of PM and NOx emissions.
>
>
> Addition of Water to Diesel Process
> Fumigation of Water into Intake Air
> Direct Injection of Water
> Fuel Emulsions
> Practical Embodiments
>
>Addition of Water to Diesel Process
>
>Methods of Wat
