receiver for parabolic dish solar concentrator

[crikalao]

Some years ago I read an article - a coffee can, coiled copper tube at 75% dia, fill can with cement (dyed black) with a 8 oz cup inserted in the face until the cement sets - it was a discussion using the phrase Black Hole meaning the light/heat goes in - doesn't come back out - at least not via the same path.

I also build a Fresnel reflector. 4x4 masonite, thread spool at center w string & pencil to draw a spiral, cover with alum mylar, cut along spiral and mount on a X frame and start pulling the spiral. it causes the masonite to warp - there's a formula somewhere. Screwdown at each crossing of the frame. It turned a 2x2 into a match in about 20 seconds. Didn't try it on a ant hill...

Chuck

Hello Chuck,

Very interesting this project.
Today has concrete that resists heat up to 1200-1600 degrees C.

It's a good idea to improve the thermal inertia of the system.

[crikalao]

thanks to all for the safety warnings. We will use appropriate goggles and be careful.
We have included temperature sensors and an UPS in case of a blackout.

About the receiver, we could not find any on the market, so we built one (picture attached) with
a copper tube (painted black) and isolated (not seen on the picture).

As soon as the electronic is ready, we will start testing. [ATTACH=CONFIG]2533[/ATTACH]

Hello Nic,

when you put it to work?
Which temperature is projecting?
What fluid use?


Share with us the data obtained and more photos?
It will be valuable to everyone.
thank you

[liderbug]

Build a receiver

Some years ago I read an article - a coffee can, coiled copper tube at 75% dia, fill can with cement (dyed black) with a 8 oz cup inserted in the face until the cement sets - it was a discussion using the phrase Black Hole meaning the light/heat goes in - doesn't come back out - at least not via the same path.

I also build a Fresnel reflector. 4x4 masonite, thread spool at center w string & pencil to draw a spiral, cover with alum mylar, cut along spiral and mount on a X frame and start pulling the spiral. it causes the masonite to warp - there's a formula somewhere. Screwdown at each crossing of the frame. It turned a 2x2 into a match in about 20 seconds. Didn't try it on a ant hill...

Chuck

[russ]

If there are any survivors please tell us all about the experiment.

[nic]

safety and receiver

thanks to all for the safety warnings. We will use appropriate goggles and be careful.
We have included temperature sensors and an UPS in case of a blackout.

About the receiver, we could not find any on the market, so we built one (picture attached) with
a copper tube (painted black) and isolated (not seen on the picture).

As soon as the electronic is ready, we will start testing. receiver.jpg

[Windrider]

I was involved with this type of dish several year ago they can be very dangerous. We made several some 2 meter ones. a wood 2x4 would almost instantly burst into flame. We had a 2 ft. one that focused to 1/8 in. a spot on a rock at the focal point would start boiling it was so bright that we needed to wear welding helmets. You must make so that no body parts can get in the focal point.

[crikalao]

Hello,

could you please send me your sketches (as attachments) ?

At the moment we are building a cylindrical copper coil, with a diameter 10 cm.
The copper pipe we are using has a external diameter of 8mm and an internal diameter of
6 mm.

Nic

Hey Nic,

you can find something on the receiver?
We are also beginning to develop here in Brazil for drying gypsum.

Not found any material on sizing or supplier.

Do you have something?

[nic]

copper coil

Hi Nic, I'm from Romania and are also interested in something, I did some sketches for a receiver, one is copper pipe coil, another flat panel, which resembles an aluminum radiator for electronic parts, sorry for English my

Hello,

could you please send me your sketches (as attachments) ?

At the moment we are building a cylindrical copper coil, with a diameter 10 cm.
The copper pipe we are using has a external diameter of 8mm and an internal diameter of
6 mm.

Nic

[Sunny Solar]

personally Ithink a 6ft parabolic is to big as a first experimental exercise . The focal point temperatures can reach over 500deg C in seconds.
A 3 ft dia one is big enough to do just about any experiment and less likely to cause damage to others. Even with that size you can melt a 1/4 in thick aluminium pot is seconds.. They really do get that hot. So it follows that any receiver needs to be designed to take those temperatures and if part of the design is to have a fluid to be heated flowing through the receiver it must be designed so if there is a fluid flow failure the reflector within seconds rotates to a safe setting . If that is not designed into it you are going to get super heated fluid and then metal exploding in all directions..

Parabolic reflectors are not toys and are very unforgiving if something goes wrong..

[giorgioart]

solar receiver

Hello,

with my students, we are building a solar tracker using a 180cm parabolic dish
(pretty much like this one: http://www.heliotrack.com/Dish180.html ).

We have the tracking almost under control but my question here is about the
receiver which should be placed at the focus of the parabola. The heat fluid should
go through "spiraling" pipes in the receiver, get heated and then go back to the water
tank in the house.

Does anyone know where to buy such a receiver (even second hand)? if not, can anyone
help us on how to build it (material, dimension, etc).

thanks,
Nic

Hi Nic, I'm from Romania and are also interested in something, I did some sketches for a receiver, one is copper pipe coil, another flat panel, which resembles an aluminum radiator for electronic parts, sorry for English my

[Mike90250]

With a dish collector, you can get dangerously high temperatures in a second, and it's intensely bright
1502_1_600.jpeg5d6f12fb-e648-4f92-b9a9-486ff45d41da.large-profile.jpg
about 15 seconds to cook a hot dog.

Time to vaporize your collection fluid and blow the system apart in someones face is quicker than the alarm for your circulation pump to trigger. Be very careful.

I like the idea of a large vessel, plumbed with large bore pipe, to a large tank above it, so that a natural thermosiphon loop is created, and you have some amount of time to detect a leak and un-aim the mirror

[GreatBallofFire]

Hello,

with my students, we are building a solar tracker using a 180cm parabolic dish
(pretty much like this one: http://www.heliotrack.com/Dish180.html ).

We have the tracking almost under control but my question here is about the
receiver which should be placed at the focus of the parabola. The heat fluid should
go through "spiraling" pipes in the receiver, get heated and then go back to the water
tank in the house.

Does anyone know where to buy such a receiver (even second hand)? if not, can anyone
help us on how to build it (material, dimension, etc).

thanks,
Nic

Nic,

There are several people that post regularly on this forum that have some experience with large parabolic dishes and high temperature. I would recommend doing a search for parabolic dishes and then you will notice a few of the same people that respond to those questions.

Sorry I can not help you more with your question, but I'm more familiar with linear receivers.

-Mark

[nic]

Hello,

with my students, we are building a solar tracker using a 180cm parabolic dish
(pretty much like this one: http://www.heliotrack.com/Dish180.html ).

We have the tracking almost under control but my question here is about the
receiver which should be placed at the focus of the parabola. The heat fluid should
go through "spiraling" pipes in the receiver, get heated and then go back to the water
tank in the house.

Does anyone know where to buy such a receiver (even second hand)? if not, can anyone
help us on how to build it (material, dimension, etc).

thanks,
Nic