|
|
| Peter Lowrie 2006-12-25, 8:25 pm |
| I was just wondering about using all of this wasted heat at the exhaust
manifold. What's wrong with putting a heat exchanger there and then boiling
water, condensing it in a tank above to provide distilled water for
drinking in addition to heating water for the HW cylinder. Also why
couldn't one put another heat exchanger at the tailpipe to cool the exhaust
gases down to a solid form. Surely the heated water would also supply the
HW cylinder and the exhaust solids collecting in a drum could be sold or
treated in some way to produce some-or-other useful product.
In efficiency terms, the more heat that is utilised - in what-ever manner
serves to increase the generators overall efficiency...Doesn't it?
:-) Peter
| |
| Eeyore 2006-12-26, 9:25 am |
|
Peter Lowrie wrote:
> I was just wondering about using all of this wasted heat at the exhaust
> manifold. What's wrong with putting a heat exchanger there
You'll mess up the gas flow and reduce the engine's performance.
Graham
| |
| nicksanspam@ece.villanova.edu 2006-12-26, 9:25 am |
| Eeyore <rabbitsfriendsandrelations@hotmail.com> wrote:
>
>Peter Lowrie wrote:
>
>
>You'll mess up the gas flow and reduce the engine's performance.
Not necessarily. Intelligen's exhaust gas plate heat exchanger helped
achieve a 93% cogen efficiency in their 11 HP Lister-Petter system.
Nick
| |
| daestrom 2006-12-26, 1:25 pm |
|
"Peter Lowrie" <peterlowrie@paradise.net.nz> wrote in message
news:6951033.AbpYIb9oBb@xbox.pelnet.net...
>I was just wondering about using all of this wasted heat at the exhaust
> manifold. What's wrong with putting a heat exchanger there and then
> boiling
> water, condensing it in a tank above to provide distilled water for
> drinking in addition to heating water for the HW cylinder. Also why
> couldn't one put another heat exchanger at the tailpipe to cool the
> exhaust
> gases down to a solid form. Surely the heated water would also supply the
> HW cylinder and the exhaust solids collecting in a drum could be sold or
> treated in some way to produce some-or-other useful product.
>
> In efficiency terms, the more heat that is utilised - in what-ever manner
> serves to increase the generators overall efficiency...Doesn't it?
>
Only a couple of caveats. Cooling the exhaust gasses will result in some of
the water vapor condensing. This water will have some other compounds
dissolved in it and can be pretty corrosive. So the heat-exchanger will
rust through pretty quickly unless made of corrosion-resistant materials.
The other caveat is that if you restrict the exhaust flow, it will reduce
engine performance. But a trade-off here should be possible.
Otherwise, you're spot on. The waste heat in the exhaust system *can* be
recovered for use. Then the only question is matching engine run-time with
heating needs.
daestrom
P.S. cooling the exhaust gases down to 'solid form'?? It would take a
heat-pump to solidify CO2 and H2O. You probably should stop while still
somewhat above ambient temperatures :-)
| |
| vaughnsimon@att.net 2006-12-26, 5:25 pm |
|
Peter Lowrie wrote:
> What's wrong with putting a heat exchanger there and then boiling
> water, condensing it in a tank above to provide distilled water...
This system was once common in the US Navy for ships with IC
engines, especially in submarines.
| |
|
|
daestrom wrote:[color=darkred]
> "Peter Lowrie" <peterlowrie@paradise.net.nz> wrote in message
> news:6951033.AbpYIb9oBb@xbox.pelnet.net...
This is standadt procedure in Combined Heat and Power sytems. There's
no reason to cause an increase in back pressure on the exhaust with the
proper design. You will need a corrosion resistant system. Also you
will have to ensure that condensate in the exhaust system can drain
away, ie there are no "low" points in the sytem where condensate could
accumulate. One thing you could consider using would be the heat
exchanger from a condensing gas boiler. This would have the corrosion
proof heat exchanger and a condensate catcher and drain. It would have
to be correctly sized to get the proper gas flow
About 75% off the available energy from the fuel goes down the exhaust
pipe so there's plenty of scope.
You can also collect heat from the radiator and the oil cooler too.
|
|
|
|