Hybrid Car – More Fun with Less Gas

Solar pump and air-conditioning update - Page 3

register ::  Login Password  :: Lost Password?
Posted by Jeff on July 16, 2007, 7:30 pm
 
Morris Dovey wrote:

No, no. You must be thinking of someone else. That's not something I
would even imply. I'm sorry if I said something that may have lead you
to that.

  but word of mouth from solar panel customers has been

I can't seem to find the article I wanted at present but there is quite
a bit on irrigation pump and pipe sizing online. You'll be limited to a
max 30' of suction because that is the atmospheric pressure limit, but
you should do much better pushing water. If you are pushing then larger
pipes have less loss.


   You had mentioned caulking some of the joints, so I thought I would
mention that there are no hub connectors (they mount outside the pipe
and look like a thick rubber tube with a couple of hose clamps) that are
readily available. That may help with your tuning, also if you are
shifting from one type of pipe to another.

   Jeff


Posted by Morris Dovey on July 17, 2007, 7:59 am
 
Jeff wrote:
| Morris Dovey wrote:
|| Jeff wrote:
||| Morris Dovey wrote:
|||| Jeff wrote:
||||
||||| What kind of a head? Seems to me you should be able to get some
||||| efficiency figures with the flow rate and the head, anything
||||| over a few percent would be outstanding. The carnot maximum
||||| isn't very high.
||||
|||| Excellent question. We've already had this conversation once,
|||| Jeff, and you surely recall how it went. :-)
|||
||| Well, there's lots of things I don't remember, but I get the gist!
||
|| I'm the guy who doesn't like to publish performance numbers that
|| can't be guaranteed. I still haven't managed to add a "standard
|| sun" to our meager collection of test equipment. You were right
|| that it does put some people off,
|
| No, no. You must be thinking of someone else. That's not something I
| would even imply. I'm sorry if I said something that may have lead
| you to that.
|
|   but word of mouth from solar panel customers has been
|| better than just "ok". I'm pretty sure I won't be able to do that
|| with the pump, but there's a lot of testing (and improving) to be
|| done before I dare do any bragging.
||
|||| This time I can answer that, for the moment, I don't really care
|||| about efficiency. I only care about getting a minimal-cost
|||| easy-to-build fluidyne larger than toy size to work well enough
|||| to satisfy my own notion of "good enough".
|||
||| Seems to me that a natural use for this would be irrigation,
||| another would be circulating heated water for solar apps. Either
||| way the pump must overcome some head, a pump that pumps large
||| amount of water at 0 head has little practical use.
||
|| Yes! I'm aiming at irrigation, remote village water supply, and
|| flood/disaster recovery operations. The circulating pump
|| application is planned, and we think that this contraption may
|| work well for pumping hot air (for such mundane tasks as warming
|| the water in livestock watering troughs to prevent winter freeze).
||
||| Maximizing for flow rate at a very small head is probably not what
||| you want. You may very well find that a pump that works less well
||| at O head works much better at a higher head. This is very common
||| for commercial pumps.  Seems that different types of pumps have
||| different flow rate versus pump head curves.
|||
|||    So, forget efficiency, but think of loading down the pump to
||| get some idea of what it will do in real life.
||
|| We've already discovered that it does appear to work better under
|| load and we're itching to see if it'll pump water up from 100-200'
|| - and how large a well pipe we can lift through. With our limited
|| experience with PVC pipe I suspect that before we're done we'll
|| have both implosions and explosions, and we're bound to have at
|| least a few melt-downs. :-)
|
| I can't seem to find the article I wanted at present but there is
| quite a bit on irrigation pump and pipe sizing online. You'll be
| limited to a max 30' of suction because that is the atmospheric
| pressure limit, but you should do much better pushing water. If you
| are pushing then larger pipes have less loss.

Ouch! That means that for depths greater than 30', pumping will need
to be staged. I think that we might need to plan a closed subsystem to
pump (solar) heated water or air to subsurface stages so each will
have power to push water from that stage up to the next. The water
being raised can be used to remove heat from the cold side, but heat
will need to be pumped down. I'll need to think about this a bit
more...

|    You had mentioned caulking some of the joints, so I thought I
| would mention that there are no hub connectors (they mount outside
| the pipe and look like a thick rubber tube with a couple of hose
| clamps) that are readily available. That may help with your tuning,
| also if you are shifting from one type of pipe to another.

We looked at these, and decided that it might be trading off one
problem for another -  and that we should probably just glue the
sections as soon as practicable. The only reason for caulking was to
avoid spending on more PVC pipe than absolutely necessary.

|    Jeff

Thank you for pointing out the lift limitation. I think that can be
worked around, and being made aware of the limitation will save us a
bit of time and frustration. If you stumble upon that article, I'm
interested. Meanwhile I'll look for some of the on-line irrigation
pumping resources.

--
Morris Dovey
DeSoto Solar
DeSoto, Iowa USA
http://www.iedu.com/DeSoto/



Posted by dold on July 17, 2007, 10:59 pm
 
After a straight vacuum lift pump fails, somewhere between 26 and 30 feet,
jet subs are used down to maybe 150 feet.  You run water down a tube
through a venturi at the bottom, drawing water back to the surface.
As I recall, 1/4 of the flow rate of the pump is lost to lifting.

Below that, you could run mechanical linkage from the Stirling down to a
basket pump, essentially the check valve box that you noted, except that
you move the box up and down.  That's the technology in a grasshopper oil
pump.

--
Clarence A Dold - Hidden Valley Lake, CA, USA  GPS: 38.8,-122.5

Posted by Morris Dovey on July 13, 2007, 7:35 am
 Morris Dovey wrote:
| For anyone interested, I've just posted a photo of the fluidyne
| (liquid-piston Stirling engine) scaled-up to four-inch schedule 40
| PVC pipe on news:alt.binaries.pictures.woodworking

...and have posted a larger/better image to the web page at the link
below

--
Morris Dovey
DeSoto Solar
DeSoto, Iowa USA
http://www.iedu.com/DeSoto/StirlingProject.html



Posted by BradGuth on July 26, 2007, 7:54 pm
 
http://www.iedu.com/DeSoto/StirlingProject.html
http://www.iedu.com/DeSoto/Stirling/

I like it, as it looks absolutely terrific, and as such I'd fork out
50/50 matching funds a whole lot faster than our having detected all
of those Muslim WMD, that just so happened to look exactly like
innocent Muslims.
- Brad Guth


This Thread
Bookmark this thread:
 
 
 
 
 
 
  •  
  • Subject
  • Author
  • Date
please rate this thread