Water Injection

[ProMaritime]

Water injection was used on both reciprocating and jet engine powered airplanes for decades. I remember the old Pan Am "water wagons" (straight pipe jet Boeing 707s and DC-8s) would leave a trail of black smoke for miles on climb out until the water tank went dry. Same with Air Force KC97 and KC135 tankers. Watching them take off during the Vietnam dustup at full war-load (no room for error) from Hickam AFB in Honolulu they were so heavy they would disappear over the horizon at what looked like about 500' altitude still trying to burn the weight down to commence their climb.

 

[PM]

Did you ever wonder why steam locomotives "HUFF, HUFF, HUFF" when running hard? Why the clouds of smoke are in distinct "PUFFS" when a coal or wood fired boiler exhaust is just a steady stream of smoke?

It is because of steam injection. Instead of venting the used steam outside it can be directed into the firebox. Water (steam) is H2O, two parts oxygen, one part hydrogen, both which support combustion very well.

What happens when you pour a cup of water onto a campfire? Outburst and Outrage. It is the water converting to oxygen and hydrogen, supporting temporary extra combustion. Too much steam or water will extinguish the fire by depriving it of both oxygen and heat.

That is the science behind it. With an internal combustion engine the results are far less dramatic, and must be carefully regulated to avoid damage.

pete

 

[backinblue]

I remember this from back in the 70s when many cars were struggling with ultra lean carburetors to raise exhaust gas temperatures for the catalytic converter. Seem to remember a kit that misted water in the carburetor above a certain RPM.

Don't remember any of it being used on a diesel.

Ted

I remember the same thing for cars back in the 70 along with many other devices promising all kinds of power and economy improvements. A friend tried the water injection (from JC Whitney) and saw no improvement and eventually removed it. I agree that if it really worked, it would be more common especially commercially. Most likely snake oil. If you want to believe claims like that, might as well try some diesel additives. They claim all kinds of power and mileage improvements along with a dozen other benefits. I admit to use some myself, not because I think they help so much, but more as insurance and that they probably don't hurt.

 

[KiwiClive]

I sometimes mist water into the air filter to steam clean. Subaru use it on their high performance cars and it is a thing in the truck industry.

 

[john-o]

It's been over 57 years since I saw this subject come up. I'll add these observations... but remember, these observations are based on technology and norms of the late 50's early 60's.
I belonged to a street rod club and we built some serious cubes back then. No electronics, just hardcore do-this-try-that. I remember Popular Mechanics and hot rod mags at the time fooled around with this stuff - mist injection, but all that was just hype. Heck, one guy even sent away for a gadget that attached itself to the exhaust manifold, heated the water to a steam, then a carb base plate had this twirling blade setup that fed into the carb baseplate. After all the wrench work, we took his Studebaker Golden Hawk on a Dyno and the constant adjustments to get the horsepower off of factory settings was a nightmare. In the end analysis - we marked it all up to hype.
Here's what we found out:
-metering is a touchy thing to set and keep.
-stop and go, idle, park, and transmission type/proper vacuum servicing auto transmission was a bear to manage.
-forget seasonal influences and the on again/off again on that environment.
-engine setup from the manufacture has certain calibrations that definitely have warranty matters to address.
-contamination to lubricants servicing values, cams, distributor gear, timing chains, and other moving parts. Head gaskets, pan gaskets, any gaskets for that matter that is compromised due to wear and tear, age, lack of attention, will guarantee contamination.
Ok,,, remember, I'm chiming in here with my experiences with building gassers and strip crates. Also, with outdated technology.

 

[TWedd]

Considering the millions spent on R&D by all the engine/auto manufacturers, I think we would see it in wide use from OEM if it actually provided any benefit.

 

[rslifkin]

Considering the millions spent on R&D by all the engine/auto manufacturers, I think we would see it in wide use from OEM if it actually provided any benefit.

Not necessarily. If it only shows a benefit in some situations and comes with the inconvenience of another tank to fill, etc. they will tend to avoid it if they can.

 

[Lepke]

Before jet airliners, all the major carriers had mechanics and a shop at every airport for radial engine repairs and changes. Sometime on old hangers you'll see the shadow of a faded United, etc. sign.

Diesel Exhaust Fluid used in newer diesel road engines may have some relation to water injection. But DEF is to reduce NOₓ, not create more hp. Before I'd buy a new diesel pickup, I'd buy and older one rebuilt by one of the companies specializing in supplying reliable trucks.

The only steam I know of the is purposely injected into a boiler is used in marine water tube boilers to remove soot on the tubes. And then only a few times a day for a few minutes. Soot insulates the tubes and hurts efficiency.

Locomotive fire tube boilers release the exhaust steam into the smoke box and the steam expansion and travel thru the stack creates a vacuum and causes more air to be drawn in to the combustion area. Like having very tall stacks on old coal burning ships or factories. Heat rising up the tall stack drew in more combustion air, giving more heat and power. When ships moved to oil, it was easier to use forced draft to blow air directly into the boiler fire. In WWI, my father was an engineer on a coal burning ship that pressurized the whole boiler room to create more draft, and had air locks for access. The pressure had to be watched, to much pressure and the crew got the bends, just like divers.

 

[Xsbank]

Once upon a time, in a land called Prince Rupert, Canadian Pacific Airlines ran a sched to Vancouver with DC6Bs. 4 Pratt and Whitney R2800s and something like 90 passengers. My father told me this story. When the aircraft did its turnaround there, it was de-iced if necessary and the water-meth tanks were topped up. They always used water on take-off, which, as FF pointed out allowed for much higher power settings without detonation, even using 100/130 gasoline.

One day, on takeoff, as soon as the aircraft rotated, one of the engines quit. As you can guess, this is a real emergency and as the crew were caging the engine and running drills, the second engine quit. Now with 2 engines out, the Captain wheeled the plane around for a visual landing and declared an emergency. Turning onto final, the 3rd engine quit...luckily (like Sully) he had a lot of skill and a plane-load of luck. He touched down on the runway and the 4th engine was toast as well.

Apparently, the company supplying drums of de-ice fluid and water meth got them labelled wrong and the water meth tanks were filled with wing de-icing fluid. If the runway hadn't been at sea level and fortunately very flat, they would never have made it.

They all lived happily ever after. Except for the guy who mislabelled the drums!

 

[KnotYet]

Did you ever wonder why steam locomotives "HUFF, HUFF, HUFF" when running hard? Why the clouds of smoke are in distinct "PUFFS" when a coal or wood fired boiler exhaust is just a steady stream of smoke?

It is because of steam injection. Instead of venting the used steam outside it can be directed into the firebox. Water (steam) is H2O, two parts oxygen, one part hydrogen, both which support combustion very well.

What happens when you pour a cup of water onto a campfire? Outburst and Outrage. It is the water converting to oxygen and hydrogen, supporting temporary extra combustion. Too much steam or water will extinguish the fire by depriving it of both oxygen and heat.

That is the science behind it. With an internal combustion engine the results are far less dramatic, and must be carefully regulated to avoid damage.

pete

C'mon Pete, you're either pulling our legs or you flunked basic chemistry!

The world is covered with the oceans we dearly love because the H2O molecule
is very stable and not broken down by the temperature of ordinary combustion.
Super-heated steam commonly used in power generation is one example of this.
Oh, and it is two parts Hydrogen and one part Oxygen...

 

[RRPrather]

Its been used for years on the competition pulling tractors.

 

[tiltrider1]

My only experience with water injection was actually a water alcohol combination that we injected into the turbine engine on one of our helicopters that lowered the exhaust gas temps that allowed us to pull more power. The problem I had with this system was you were flying at the margins, something I don’t believe in doing. I understand why racers would do this and why it was used in war time. Don’t see a reason why I would do this outside of those areas. It wasn’t long before Allison made a modification to the engine that got us more power and eliminated the water injection system, at a cost of $75,000.

 

[88FuHwa]

As a mechanic in the US Air Force, I recall getting instructions on the after burner concept used on B-52 engines. I recall that they injected a combination of jet fuel and water in the last stages of the turbines to increase gaseous volume thereby increasing thrust. These airplanes spewed a lot of black exhaust gas on take off at Travis AFB, CA where I was stationed. I don't think the technology is used anymore.

 

[Lepke]

When cargo ships were steam powered, steam was used sometimes to smother a cargo fire. Especially coal bunker fires. Steam going into the combustion area of a boiler will smother the fire. Water on fire makes steam, not hydrogen and oxygen. When water becomes steam it expands 16 times. More at higher temps. When tubes blow, all the steam vents into the combustion area and up the stack. Burners are secured because that boiler isn't going to make steam until the tubes are blocked off or repaired. And the boiler has to be cooled and drained. Ask Wallace Beery - Tugboat Anny.