h a l f b a k e r y
What was the question again?
add, search, annotate, link, view, overview, recent, by name, random
news, help, about, links, report a problem
or get an account
so i was thinking that there has to be some way to use the exhaust gas from a car. why not use a like the exhaust side of a turbo to run the alternator, and/or powersteering, and/or airconditioner. (on most cars there should be enough exhaust to go around) this way instead of robing power from the engine
you take the excess energy from the exhaust.
to do the simple guesstamating math. you would save a good 50 to 60 HP but that would also mean you have to have a turbo that produces that much as well and i think that's very possible.
btw if you thinking why not just add a turbo, the big problem with turbos is they require much more equipment than just a turbo most of the time adding four or five times the cost of the actual turbo...
||I think exhaust driven alternators are already baked (they're at least in development), and its already been posted on the halfbakery. Sorry I don't have a link for you (its late and I'm tired). It's still a pretty good idea though.
||The 'turbo alternators' under development are part of an integrated system including turbo, supercharger and alternator.
It must also be understood that the energy in exhaust gas is not free. A turbo creates back pressure, which makes it harder for the engine to push exhasut out. When this is used to increase inlet pressure, it is an advantage because it means the volumetric effeciency of the engine is improved and that is worth more than the 'cost' of the added back pressure.
I would also argue your figures. A very powerful (750W) alternator uses about 2 HP if it is working flat out, which it usually isn't.
A 50 HP turbo is a small gas turbine engine. Energy available in exhaust gas pressure is maybe a few HP, but it's not free.
||hmm didn't realise it was already done... but the very small back pressure that the device would create would be nothing to compared to the benefits. i don't know how much HP it would take to run each of these things that are now run off of belts but you could mix and match these things anywhere from 2hp for just the alternator to however much this half turbo can run. your right the exaust if not free energy but it's next to free, were wasting a lot of useable energy.