View Single Post
Old 01-16-2012, 09:58 AM   #92 (permalink)
Air-Hybrid
EcoModding Apprentice
 
Join Date: Aug 2009
Location: London, UK
Posts: 113
Thanks: 16
Thanked 3 Times in 3 Posts
Quote:
Originally Posted by Josh8loop View Post
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.


Quote:
Originally Posted by Josh8loop View Post
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.
  Reply With Quote