Solar collector design and simulation considerations

[OAQfirst]

http://a11news.com/231/raw-solar/

First, isn't this dangerous for birds? Secondly, if someone doesn't aim it just right, could it burn down a nearby house/barn?

 

[edward]

QUOTE=OAQfirst

First, isn't this dangerous for birds? Secondly, if someone doesn't aim it just right, could it burn down a nearby house/barn?

A bird would be toast if it landed at the focal point. I think that any bird would be spooked away by the glare of the reflector.

The thing does look like some type of ray gun. But as far as setting anything on fire the really intense heat is only at the focal point.

 

[Chi Meson]

COrrect me if I am wrong, but this "breakthrough" is just a mirror (spherical or parabolic) that has a relatively inexpensive support structure. As of yet it does not seem to be part of a practical solar energy delivery system.

The dish generates so much heat that it will melt steel at it’s focal point. That type of immensely concentrated solar energy can cheaply produce green power by using steam turbines to produce either heat or electricity.

There's a big "yada yada yada" in that one. As well as an "I have no idea what I'm saying." It will use intense heat to produce heat? Brilliant!

OK, it is actually a very nice little mirror. I imagine you could pipe heat transfer fluid through the focal point and get hot water that way, but it would require a tracking device to keep it turned to the sun. After all that, would it collect solar heat any better than a static flat panel collector of the same area?

 

[Astronuc]

That type of immensely concentrated solar energy can cheaply produce green power by using steam turbines to produce either heat or electricity.

Solar thermal (dynamic) systems have been around for awhile, so there's nothing new here. Perhaps the simplicity (low cost) is the innovation.

http://www.sandia.gov/Renewable_Energy/solarthermal/NSTTF/furnaces.htm

One is still constrained by the solar radiation (light) flux, which limits the rate at which energy can be collected/transformed.

http://www.abengoasolar.com/sites/solar/en/nproyectos_ps10.jsp
http://en.wikipedia.org/wiki/Solar_power_tower

http://www.brightsourceenergy.com/dpt.htm

http://en.wikipedia.org/wiki/Solar_One

 

[OAQfirst]

OK, it is actually a very nice little mirror. I imagine you could pipe heat transfer fluid through the focal point and get hot water that way, but it would require a tracking device to keep it turned to the sun. After all that, would it collect solar heat any better than a static flat panel collector of the same area?

How about curving the design like an inverted half donut or crescent so that instead of a single focal point, we'd have an arc for the sun to trace?

 

[Chi Meson]

How about curving the design like an inverted half donut or crescent so that instead of a single focal point, we'd have an arc for the sun to trace?

I was already thinking ahead: The mirror should not be in an arc, but the fluid pipe itself could follow along the arc that the focus moves. Still, the mirror or the pipe should be adjusted at least weekly to compensate for the change in azimuth. Seems too impractical to me (compared to the basic solar collectors I have on my roof) . But I'll wait and see what the MIT kids do with it.

 

[K.J.Healey]

Basically like a condensed solar tower?
http://hea.cwru.edu/stacee/images/sandia_back_view_small.jpg

(at sandia in new mexico, got to see it in person when i worked there.)

 

[aelsawis]

i am studying an air solar collector system that has an V-corrugated absorber plate.the the flow channels are in one case linear in the other case they ar zig-zag (continues bends along the length). i need to know how to simulate the second case a triangular cross section channel with a zig-zag channel length.how can i take the effect of the head loss and how to calculate it? thanks a lot for ur help

 

[moose]

http://a11news.com/231/raw-solar/

First, isn't this dangerous for birds? Secondly, if someone doesn't aim it just right, could it burn down a nearby house/barn?

Umm, if you wanted to place the focal point exactly at the wall of a house, then probably. I believe it'd be easier to light a house on fire with more conventional means though... It'd be hard to accidentally aim it at a house exactly at its focal point...

 

[tribdog]

What's wrong with having it track the sun? couple of servos and a simple computer program would take care of that.

 

[Redbelly98]

Umm, if you wanted to place the focal point exactly at the wall of a house, then probably. I believe it'd be easier to light a house on fire with more conventional means though... It'd be hard to accidentally aim it at a house exactly at its focal point...

Exactly. The house would have to be located within 10 or 15 feet of the collector.

 

[Moonbear]

Umm, if you wanted to place the focal point exactly at the wall of a house, then probably. I believe it'd be easier to light a house on fire with more conventional means though... It'd be hard to accidentally aim it at a house exactly at its focal point...

This whole thread, and especially this point, is reminding me of a MythBuster's episode. They were testing some claim about using mirrors as a "ray gun" kind of concept to burn a wooden ship (supposedly some ancient "technology" used in war). I think with a whole bank of mirrors built by some MIT team, they got something to smolder a bit. I wonder if the two projects are related or for the same class?

Here's a link to the MIT Mythbusters test I was thinking about:
http://web.mit.edu/2.009/www/experiments/deathray/10_Mythbusters.html

 

[russ_watters]

****Necropost Alert*****

 

[CaptainQuasar]

How about curving the design like an inverted half donut or crescent so that instead of a single focal point, we'd have an arc for the sun to trace?

Heh heh - from 1901:

 

[Helios]

First, isn't this dangerous for birds?

Well now, wouldn't that be a pleasant surprise to have a tasty little snack waiting there when you go to check your collector?

 

[Redbelly98]

Aauuuuuurgh!

OLD THREAD ALERT! OLD THREAD ALERT!

 

[Topher925]

!

 

[CaptainQuasar]

Yeah... let's get back to those young, hot, vivacious threads.

If old threads are declassé in GD, why not just lock them?

⚛​

 

[Redbelly98]

i am studying an air solar collector system that has an V-corrugated absorber plate.the the flow channels are in one case linear in the other case they ar zig-zag (continues bends along the length). i need to know how to simulate the second case a triangular cross section channel with a zig-zag channel length.how can i take the effect of the head loss and how to calculate it? thanks a lot for ur help

I would recommend starting a new thread. As you can see, people tend to miss your request if it's just tacked onto (and soon buried in) an existing discussion.

For this question, a good place to ask would be the Engineering Systems and Design subforum:
https://www.physicsforums.com/forumdisplay.php?f=99

After going to that link, click the "New Topic" button to post your question.

Yeah... let's get back to those young, hot, vivacious threads.

If old threads are declassé in GD, why not just lock them?

⚛​

Excuse my reaction. No, there's nothing inherently wrong with reviving a thread, especially in GD. But directly addressing a question asked months ago is kind of odd. I've done it too, only LATER to realize the question was asked quite a while ago. That kind of thing just makes me smack myself in the forehead (carefully avoiding stabbing myself on my beak ) and say "Doh!"