Go Back   Science Forums > Physical Sciences Forums > Environmental Studies
Reply
 
LinkBack Thread Tools
Old 08-14-2008   #31 (permalink)
Overdog's Avatar
Explaining


Location:
Virginia
 
Overdog is a splendid one to beholdOverdog is a splendid one to beholdOverdog is a splendid one to beholdOverdog is a splendid one to beholdOverdog is a splendid one to beholdOverdog is a splendid one to behold
 



Not Ranked  0 score     
Re: Passive Electrical Generator

Sorry...

I have to wonder about the economics and practicality of it though, googleing thermosiphon generators doesn't seem to turn up much (besides patent applications)...
Reply With Quote
Old 08-14-2008   #32 (permalink)
modest's Avatar
Creating

Moderator

Location:
U.S. Midwest
 
modest has a reputation beyond reputemodest has a reputation beyond reputemodest has a reputation beyond reputemodest has a reputation beyond reputemodest has a reputation beyond reputemodest has a reputation beyond reputemodest has a reputation beyond reputemodest has a reputation beyond reputemodest has a reputation beyond reputemodest has a reputation beyond reputemodest has a reputation beyond repute
 



Not Ranked  0 score     
Re: Passive Electrical Generator

Quote:
Originally Posted by Nitack View Post
As always, I may be wrong, but convection would happen if this were taking place in a single chamber. Warmer liquid would move to the top, cooler to the bottom. What this setup is doing is channeling the flow. To reach the highest point in the system I propose, as the least dense liquid will naturally do, it must exit the heating assembly at one specific point. Once it leaves from that point more water will need to be drawn into the heating assembly to occupy the space left vacant from the water that flowed out.
Cold water doesn't want to rise. If you intentionally cool water below the level where you're heating it then you're loosing potential - certainly not gaining any.

~modest


----------------
Reply With Quote
Old 08-14-2008   #33 (permalink)
modest's Avatar
Creating

Moderator

Location:
U.S. Midwest
 
modest has a reputation beyond reputemodest has a reputation beyond reputemodest has a reputation beyond reputemodest has a reputation beyond reputemodest has a reputation beyond reputemodest has a reputation beyond reputemodest has a reputation beyond reputemodest has a reputation beyond reputemodest has a reputation beyond reputemodest has a reputation beyond reputemodest has a reputation beyond repute
 



Not Ranked  0 score     
Re: Passive Electrical Generator

Also, the hose on your diagram labeled #2 would need to have a one-way valve since the generator would offer resistance. Otherwise it would just use the one hose to try and reach equilibrium.

~modest


----------------
Reply With Quote
Old 08-14-2008   #34 (permalink)
Nitack's Avatar
Understanding


Location:
Washington DC
 
Nitack has much to be proud ofNitack has much to be proud ofNitack has much to be proud ofNitack has much to be proud ofNitack has much to be proud ofNitack has much to be proud ofNitack has much to be proud of
 



Not Ranked  0 score     
Re: Passive Electrical Generator

Quote:
Originally Posted by Overdog View Post
I took the graphic from the Wikipedia thermosiphon article and modified it to reflect what I had in mind.

Passive Electrical Generator-610px-thermosiphon2.jpg
Reply With Quote
Old 08-14-2008   #35 (permalink)
Nitack's Avatar
Understanding


Location:
Washington DC
 
Nitack has much to be proud ofNitack has much to be proud ofNitack has much to be proud ofNitack has much to be proud ofNitack has much to be proud ofNitack has much to be proud ofNitack has much to be proud of
 



Not Ranked  0 score     
Re: Passive Electrical Generator

Quote:
Originally Posted by Overdog View Post
Sorry...

I have to wonder about the economics and practicality of it though, googleing thermosiphon generators doesn't seem to turn up much (besides patent applications)...
I have no delussions of setting up my own power company/cooperative using this design. However, I think i can build the system for a relatively cheap investment and from there it will continuously produce electricity. It won't power my house, but it will supplement my energy consumption and save me money.

Quote:
Originally Posted by modest View Post
Cold water doesn't want to rise. If you intentionally cool water below the level where you're heating it then you're loosing potential - certainly not gaining any.

~modest
I thought about that. I was trying to figure out if the pressure change in a closed loop would help mitigate the loss of potential. For every amount of water is rising at one point in the system an equal mass of water is also being pulled down at another point. This causes me to believe, although I admittedly have a novice grasp of the concepts I am delving into, that the gravity from one side of the system pulling down water will cancel out the gravity being fought at the other side of the system. Is this correct?

The idea of going into the ground was to create a heat sink so that water could be cooled in order to store more solar energy. If the difference between the temperature of the water entering the heating assembly and leaving the heat assembly is only 2 degrees Celsius, that will not produce as much energy as if the difference were 10-20 degrees Celsius.

Quote:
Originally Posted by modest View Post
Also, the hose on your diagram labeled #2 would need to have a one-way valve since the generator would offer resistance. Otherwise it would just use the one hose to try and reach equilibrium.

~modest
I figured a one way valve might need to be added there. That would create drag and cost potential energy, but it may not be able to be helped.

Last edited by Nitack; 08-14-2008 at 06:56 AM..
Reply With Quote
Old 08-14-2008   #36 (permalink)
modest's Avatar
Creating

Moderator

Location:
U.S. Midwest
 
modest has a reputation beyond reputemodest has a reputation beyond reputemodest has a reputation beyond reputemodest has a reputation beyond reputemodest has a reputation beyond reputemodest has a reputation beyond reputemodest has a reputation beyond reputemodest has a reputation beyond reputemodest has a reputation beyond reputemodest has a reputation beyond reputemodest has a reputation beyond repute
 



Not Ranked  0 score     
Re: Passive Electrical Generator

Quote:
Originally Posted by Nitack View Post
I thought about that. I was trying to figure out if the pressure change in a closed loop would help mitigate the loss of potential. For every amount of water is rising at one point in the system an equal mass of water is also being pulled down at another point.
Yeah, I see where you're coming from. I think the problem you might find is that making it rise on one side will not automatically make it fall on the other side. A system like this would be perfectly happy heating the water at the top and never circulating that water back down.

As a convection system - it's completely open to pressure changes. If the pressure changes on the left side, that pressure difference is immediately felt on the right side. Something like a steam engine or an air conditioning coil or heat pump that uses pressure differentials has to completely seal half of the loop off from the other half at any given time which is different from a convection flow like you're going for. It might be best to think of water floating and sinking rather than pushing.

Quote:
Originally Posted by Nitack View Post
This causes me to believe, although I admittedly have a novice grasp of the concepts I am delving into, that the gravity from one side of the system pulling down water will cancel out the gravity being fought at the other side of the system. Is this correct?
I'm not exactly sure what you mean. Gravity will make the heavier water sink and the lighter water float which as you know happens because of temperature differences.

Quote:
Originally Posted by Nitack View Post
The idea of going into the ground was to create a heat sink so that water could be cooled in order to store more solar energy. If the difference between the temperature of the water entering the heating assembly and leaving the heat assembly is only 2 degrees Celsius, that will not produce as much energy as if the difference were 10-20 degrees Celsius.
Yes, it can. Absolutely. As your design has it:



The blue tank below the brown line I added (the ground level) is quite a bit colder than the water that's above the brown line. This means it will be relatively easy to heat water and make it want to float above point one. However, this also means it will be more difficult to cool water and make it want to sink below point two. As your system must circulate from point one back to point one in order to generate power, the colder temperature below point one and two cancel out.

In fact, it will work against you when the temperature at A and B start to equalize. You'll run into the situation where everything above the brown line is significantly warmer than everything below the brown line. In other words, the warm stuff is at the top where it wants to be and the cold stuff is at the bottom where it wants to be. The temperature difference above one and below one will be a lot as you say - but unless water wants to sink out of B, the system won't circulate.

Generally speaking, I think the following is a safe bet.

Starting with this setup (where a valve forces the water to move clockwise) [don't forget to consider gravity]:



This would be an improvement to efficiency:



And this would hinder circulation:



This was my thinking. But, I do think there are a lot of variables and what-not, I'm very open to seeing things differently.

~modest


----------------

Last edited by modest; 08-14-2008 at 03:29 PM..
Reply With Quote
Reply

Bookmarks


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools


Similar Threads
Thread Thread Starter Forum Replies Last Post
Technology makes passive life seducing coberst Philosophy Forums 11 09-30-2007 01:17 PM
sound to electrical toohot421 Science Projects and Homework 2 08-26-2007 10:37 PM
Good vibes power tiny generator theblackalchemist Science News Elsewhere 0 07-08-2007 12:01 AM
Tidal Generator. arkain101 Strange Claims Forum 11 12-30-2005 12:56 PM
passive smoke and crossing a street sanctus Medical Science 17 06-16-2005 11:41 AM

» Advertisement
» Current Poll
Who's the sexiest man alive? Johnny Depp or Robert Pattinson?
Johnny Depp - 27.27%
3 Votes
Robert Pattinson - 0%
0 Votes
Someone else (please specify) - 45.45%
5 Votes
I'm too macho to think a guy is sexy - 27.27%
3 Votes
Total Votes: 11
You may not vote on this poll.


All times are GMT -8. The time now is 11:58 AM.

Hypography?

Hypography [n.]: A combination of "hyperlink" and "bibliography" - ie, a list of links to electronic documents. Comparable to discography and bibliography, but not cartography.

We have been online since May 2000, and aim to be the best place to find and share science-related content of all kinds.

Share the love!

Please add more science to your life. Use our RSS feeds on your blog, your portal, or your favorite feedreader!


Powered by vBulletin® Version 3.8.3
Copyright ©2000 - 2009, Jelsoft Enterprises Ltd.
Search Engine Optimization by vBSEO 3.3.2
Copyright © 2000-2009 Hypography
Part of the Hypography - Science for Everyone Network