I find on very windy days my 20 foot long pipe is marginal unless the fire is hot. I need that much lift to offset the partial pressure made by the wind. I haven't made any effort to capture the heat moving out the stack. Those thermoelectric semiconductors they are touting look interesting. They never seem to make it to market though.
Kirk ----- Original Message ----- From: "robert luis rabello" <[EMAIL PROTECTED]> To: <biofuel@yahoogroups.com> Sent: Thursday, February 21, 2002 12:36 AM Subject: Re: [biofuel] Making Something From Nothing > > > kirk wrote: > > > I know the chimney > > needs hot gases to work, > > > > Since it is reduced density generating the needed lift it seems to me you > > could use a well insulated stack and extract the heat at the last moment. > > True. However, as long as the stack remains inside my house, it contributes > to space heating. > > <snip> > > > > If > > you want to discuss it on micro > > cogen it is fine with me. Cogen is cogen. I just advocate diesel because it > > is off the shelf and top efficiency. > > I haven't discussed it because my system isn't working! When I did this > with steam, I ended up with less than 1% conversion efficiency from wood to > electricity. If my math is right for the Rankine cycle, I'll end up with about > 17% conversion efficiency using the lower temperature working fluid without > superheat. That's more than enough! I can use the "waste" heat for domestic > purposes. > > > > > I suppose there would be lots of problems powering a Brayton cycle with > > wood. Charcoal might be ok but I think wood has lots of goop problems. I > > suppose your wood heated closed cycle is a reasonable compromise. > > > > The cyclical effect of wood burning, coupled with the high latent heat of > water, stabilizes the expander's operation. I plan a "vapor cycling" system > that only activates the expander when vapor pressure reaches a set point. > (Batteries don't care if their charging is intermittent.) Wood burning also > eliminates the need for feed stock pre treatment characteristic of gasification > systems, and the serious energy losses involved in creating charcoal. It > wouldn't be a perfect system, but it would be nice if I could actually get it to > work! > > robert luis rabello > > > > Biofuel at Journey to Forever: > http://journeytoforever.org/biofuel.html > Please do NOT send "unsubscribe" messages to the list address. > To unsubscribe, send an email to: > [EMAIL PROTECTED] > > Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/ > > > ------------------------ Yahoo! Groups Sponsor ---------------------~--> Get your FREE credit report with a FREE CreditCheck Monitoring Service trial http://us.click.yahoo.com/ACHqaB/bQ8CAA/ySSFAA/FGYolB/TM ---------------------------------------------------------------------~-> Biofuel at Journey to Forever: http://journeytoforever.org/biofuel.html Please do NOT send "unsubscribe" messages to the list address. To unsubscribe, send an email to: [EMAIL PROTECTED] Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
