Salt, science and energy.
#61
(01-01-2012, 11:12 AM)tvguy Wrote: Here's your boy...

[Image: Merced.jpg]

http://www.solarnovus.com/index.php?opti...Itemid=247

And maybe this is the way to go too. I've seen what I think you're showing us here on ebay relatively inexpensively lately, with Chinese made units. I haven't seen anybody fill one with oil and run an oven or other things with it (by letting it get hotter than water), but I've wondered about that.

I'm perhaps most worried about losing the vacuum on the collection tubes, I've read hints that expected life might be only 20 years or so. Then again perhaps that's enough. I'm not sure how much I trust Chinese manufacturing here either.
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#62
(01-01-2012, 10:50 PM)PonderThis Wrote: I'm sorry, I can't remember now what you're referring to as "trench". Do you mean trough?

Yes, some designs do adjust for the difference in sun position between seasons. I think they're often pointed for optimum during winter, when the sun is needed most, in favor of summertime angles when you might not need the heat (or power, etc.) as much. But those are minor design issues I think.

I'm thrilled to hear you've got your fertile mind working on this. Smiling

Yes trough (kind of a trench above ground Big Grin),
If you point it at the winter sun, then in summer you be 47 degrees off, cosine of 47 degrees is 0.682, your loosing 32% of you collection.

The system should be designed to adjust the tilt every 3 months or so That should be easy enough.
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#63
For a portable barbecue, that would be easy enough (maybe a foot pedal to operate). For house use, one angle you could leave it at seems like it would be most trouble free to me.
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#64
More analysis on the mirror.
The non tilt design requires the sun reflect onto the pipe with a +/- 23.5 degrees.

See picture below
[Image: solar2.jpg]

This tells us the ratio of pipe diameter to mirror distance.

The Tangent of 23.5 degrees = D/(2*L)

or that
The diameter is 0.87 *L
or L= Diameter * 1.15

I need to consider rays that overshoot the pipe and hit the other surface.

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#65
(01-02-2012, 11:32 AM)PonderThis Wrote: For a portable barbecue, that would be easy enough (maybe a foot pedal to operate). For house use, one angle you could leave it at seems like it would be most trouble free to me.

Tilting wouldn't be hard if the mirror system was supported by the pipe.
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#66
(01-02-2012, 11:42 AM)chuck white Wrote: More analysis on the mirror.
The non tilt design requires the sun reflect onto the pipe with a +/- 23.5 degrees.

See picture below
[Image: solar2.jpg]

This tells us the ratio of pipe diameter to mirror distance.

The Tangent of 23.5 degrees = D/(2*L)

or that
The diameter is 0.87 *L
or L= Diameter * 1.15

I need to consider rays that overshoot the pipe and hit the other surface.

I think if I'm correct this design collector is typically oriented north and south, so your drawing is sort of incorrect. They're oriented north and south, and then the mirrored part rotates throughout the day to track the sun from left to right in the sky.

That's part of what makes the non-tracking design novel, is it's oriented east and west instead.
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#67
(01-02-2012, 11:46 AM)chuck white Wrote:
(01-02-2012, 11:32 AM)PonderThis Wrote: For a portable barbecue, that would be easy enough (maybe a foot pedal to operate). For house use, one angle you could leave it at seems like it would be most trouble free to me.

Tilting wouldn't be hard if the mirror system was supported by the pipe.

For any permanent installation (like, on rooftops) in our climate, I'm really worried about effects of snow and ice on the mechanisms. That's another reason I like the idea of something that can just sit there, fixed into place.
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#68
(01-02-2012, 11:50 AM)PonderThis Wrote:
(01-02-2012, 11:42 AM)chuck white Wrote: More analysis on the mirror.
The non tilt design requires the sun reflect onto the pipe with a +/- 23.5 degrees.

See picture below
[Image: solar2.jpg]

This tells us the ratio of pipe diameter to mirror distance.

The Tangent of 23.5 degrees = D/(2*L)

or that
The diameter is 0.87 *L
or L= Diameter * 1.15

I need to consider rays that overshoot the pipe and hit the other surface.

I think if I'm correct this design collector is typically oriented north and south, so your drawing is sort of incorrect. They're oriented north and south, and then the mirrored part rotates throughout the day to track the sun from left to right in the sky.

That's part of what makes the non-tracking design novel, is it's oriented east and west instead.

The design I'm showing is for a east west running trough, But the sun still moves up and down from summer to winter.

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#69
(01-02-2012, 11:53 AM)PonderThis Wrote:
(01-02-2012, 11:46 AM)chuck white Wrote:
(01-02-2012, 11:32 AM)PonderThis Wrote: For a portable barbecue, that would be easy enough (maybe a foot pedal to operate). For house use, one angle you could leave it at seems like it would be most trouble free to me.

Tilting wouldn't be hard if the mirror system was supported by the pipe.

For any permanent installation (like, on rooftops) in our climate, I'm really worried about effects of snow and ice on the mechanisms. That's another reason I like the idea of something that can just sit there, fixed into place.

I can see why a roof top job should be non tilt design.
Then were limited to the concentration factor that will only triple the intensity. This will limit the upper temperature of the water.
we could build larger collectors but that would only gives us more heated water, not hotter water.
We could get hotter with the vacuum tube collector and higher reflecting material.

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#70
They always say this design needs to track the sun from left to right throughout the day. I'm not certain that's correct, but my mind gets hung up on that. I'm not sure the difference between summer and winter otherwise is an important a tracking need. Indeed, the best looking design to me was that double parabola version that was slanted southward:

[Image: how6.jpg]
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#71
For the expense of the Vacuum tubes, I would rather put in a tracking system.
solar powered motors and we could track the sun east west and up down.
Maximum water temperature would be enormous, depended on concentrator size.
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#72
(01-02-2012, 12:05 PM)PonderThis Wrote: I'm not sure the difference between summer and winter

Go out at noon and tell me how high the sun is in the sky, and then remember last June, how high the noon sun was.
there is a 47 degree difference.
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#73
I'm not convinced it would have to be a vacuum tube, if it was in an insulated box covered with glazing.

I'll post my chart on the advantages of vacuum tubes over metal pipe, I think this came from one of the manufacturers:

[Image: evacuatedtubeefficiency.jpg]

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#74
Interesting chart, not much improvement with a delta 100 C,
Wind does effect it a lot.
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#75
That's why I speculate a piece of glazing over it (to keep out wind) with a cheap pipe collector might be more durable and work practically as good too.

BTW, good work on the chart. I had to study it for half an hour to figure what was going on, and I expected you to ask questions. Smiling
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#76
Are either one of actually going to make something?

edit, that sounded bitchyLaughing I was actually serious. I'm pretty sure Ponder has already said he was wanting to wait and buy a collector. But what about you CW.

Are you gonna shit or get off the potLaughingLaughing And if you build something, what are you trying to accomplish? heat for your house , hot water? other?

Me, I basically wanted an evil death ray ever since I saw Dr. EvilRazz
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#77
I'm willing to finance Chuck making one if he thinks it's a good idea and has an appropriate design. I don't know if Chuck knows that yet. Maybe you'll be the one fabricating it.

I'll do it for profit if it takes that to provoke anybodies interests, otherwise my personal preference is to place everything in the public domain.
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#78
(01-02-2012, 12:36 PM)PonderThis Wrote: I'm willing to finance Chuck making one if he thinks it's a good idea and has an appropriate design. I don't know if Chuck knows that yet. Maybe you'll be the one fabricating it.

I'll do it for profit if it takes that to provoke anybodies interests, otherwise my personal preference is to place everything in the public domain.

OK , you talked about using it for a solar oven. What if this is to be sold is the intent for this device regardless of who makes it?

The Thermal engine? What will it run?
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#79
I prefer to think things through first.
I hate changing design in the middle of a build.
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#80
(01-02-2012, 12:41 PM)tvguy Wrote:
(01-02-2012, 12:36 PM)PonderThis Wrote: I'm willing to finance Chuck making one if he thinks it's a good idea and has an appropriate design. I don't know if Chuck knows that yet. Maybe you'll be the one fabricating it.

I'll do it for profit if it takes that to provoke anybodies interests, otherwise my personal preference is to place everything in the public domain.

OK , you talked about using it for a solar oven. What if this is to be sold is the intent for this device regardless of who makes it?

The Thermal engine? What will it run?

I can conceive of any number of things that could run off this one collector design. Ovens, thermal engines that power generators, hot water - indeed, if you wanted to get really far fetched, suppose that they really did decide that electrical wiring was causing emf radiation that was causing cancer, what then? I can envision houses with built in hydraulic systems, where you could plug in your refrigerator say into the hydraulic system just like plugging in an air hose on your compressor, and run it off fluids instead. I'm sure there would be ways to charge fuel cells with hydrogen using heat or electricity too. There really could be no end to uses for solar energy.

Besides, I see solar energy and cheap collectors as the sort of thing that could change the world, especially if people could do this cheaply with common materials and paper mache', say, just for example. Besides, I see a future where we have inventive minds but not much money anyway, and I see this sort of collaboration as one of the most useful of endeavors. Call me idealistic. Smiling

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