--- Water injection VS Steam Injection ---

[oil pan 4]

Originally Posted by Old Tele man

...the Wankel was "revolutionary" once too, but it never lived up to it's hype either.

Yeah, when I hear wankel and good fuel economy in the same sentence I laugh. And its always said by people who have never owned or worked on them.

[Air-Hybrid]

Originally Posted by Josh8loop

I have made heat pipes myself really easily that worked extremely well FWIW.

That's interesting Josh. I'd like to hear more about your experiences making DIY heatpipes. What applications have you used them for?
I procured one for myself from a defunct 80s audio amp - it's literally a straight brass tube sealed off at either end. Though I haven't put it to any specific use as yet I suspect that most automotive apps would be to hot for it to work efficiently.

Originally Posted by Josh8loop

Instead of using high pressure pumps and injecting nozzles which require moderate electrical energy we are using waste heat to our advantage to tip the tables in our favor. Thats why I mentioned using coolant heat and ultrasonic device together with the throttle vacuum to more easily create water vapor. ... The electrical demand of the ultrasonic vaporizer coupled with the sub boiling water really lowers the energy input required to get that water into the intake stream. Even if experimentally we found that the coolant temps drop too much with this approach, then we can just use exhaust heat through a heat pipe to accomplish the same effect.

I have also considered using ultrasonics for mist creation, but one thing that might negate its efficiency gains is having to convert energy 3 times (mech-to-electrical-to-mist) with ultrasonic as opposed to once with a mechanical injector pump. Also I would like to get some figures on how much (if any) having hotter water would help it atomise off the sonics. Gut feeling is that water just below boiling would require substantially less electrical energy to 'break-free' but this might be a false assumption.


The main issue I have with the OP's suggestion that steam rather than water can recover some of the waste heat rejected in the exhaust is that the argument runs counter to the process that makes a heat-engine work.

[Josh8loop]

Originally Posted by Air-Hybrid

That's interesting Josh. I'd like to hear more about your experiences making DIY heatpipes. What applications have you used them for?
I procured one for myself from a defunct 80s audio amp - it's literally a straight brass tube sealed off at either end. Though I haven't put it to any specific use as yet I suspect that most automotive apps would be to hot for it to work efficiently.



I have also considered using ultrasonics for mist creation, but one thing that might negate its efficiency gains is having to convert energy 3 times (mech-to-electrical-to-mist) with ultrasonic as opposed to once with a mechanical injector pump. Also I would like to get some figures on how much (if any) having hotter water would help it atomise off the sonics. Gut feeling is that water just below boiling would require substantially less electrical energy to 'break-free' but this might be a false assumption.


The main issue I have with the OP's suggestion that steam rather than water can recover some of the waste heat rejected in the exhaust is that the argument runs counter to the process that makes a heat-engine work.

The heatpipes(2) I made were quite rudimentary but worked well. They were more like thermosiphons since they had no wick structure, and needed to be oriented with hot end lower than the cold end to work. I ended up using a 3' piece of 3/8"copper tubing and sealed one end with solder. I dribbled a small amount of acetone into the tube, dipped the tube in chilled water, applied a vacuum to the pipe, and hammered the end until it was pinched off. After it was pinched off from the slow hammering, I soldered the end shut. The other one I made was similar in construction, but I pinched the end shut with a vice, and soldered it shut. They both worked well, and would transfer heat from one end to the other(3 feet) in around 20-30 seconds. Solid copper that long would take a hour to do that.

There are much better construction methods out there than I used, but it proved to me that a functional unit could be home brewed. Wick material could also be inserted to allow multiaxis functionality-you would want to select a wick material that is compatable with the working fluid. Also, water, alcohol, and many other fluids can be used as the working fluid and don't necessarily need to be under vacuum.

[Josh8loop]

Bump


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[Christ]

Wankels aren't good for fuel economy. I've owned and worked on several.

Start laughing now!

[user removed]

Good to hear from you Christ, it's been a while!

regards
Mech

[maxc]

About 25 years ago. I put small drips of water down on the exhaust right by the tube with the HAI on. Every time the water flashed too steam the rpm in the engine increased. Your all way off on the flow rate for milage increase!

[Azmio]

air hybrid,

Are you doing water injection research as well? I am now in Hethel, let's meet up someday and have a long chat.