Solar Sand Battery Evacuated Tube Implosion Solar Water Heater Thermal Storage
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- Опубликовано: 4 июн 2016
- Using Sand For Solar Thermal Heat Retention. Solar evacuated tubes are extremely efficient at transferring sunlight to heat. This heat is then transferred to the material inside. This video is for lower quality water heaters that may experience rain water infiltration from poor designs. This is also an efficient method for enhancing good designs enabling solar thermal storage. If you use heated water in the morning from a system like this, the standard fins may be a better option. The thermal storage does last several hours.
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As a co designer of the Apricus brand since 2003, and importing and testing China tubes in Cyprus in 1997, the reason explode or implode is becouse they are sold to be installed with a presurized system, which i have never done since i started in solar thermal in 1990, but i started with the developing of the hot water tank first, now called a Thermal Store also developed by my then partner in the USA Norm. My UK tube failures in the early days was found to be caused through the build up of heat in the tubes, so when we stoped useing the typical pluged tubes to open tubes with our heat pipes inside, we solved the first problem. Our latest heat pipe tube collectors now come with a sensor built into the condensor of the heat pipe, which stops tank over heating to 80c, but unless the solar industry starts to reconise that all the solar failures and the limited use of solar thermal is becouse nobody understands thermal stores, first developed in the UK by me in 1990
wow, Dan Thanks for this! I am looking to set up those evacuated tubes to heat my home with. Up here in the NE Home Heating Oil is expensive every winter ! So any way to get "almost free" heat is a big plus for us retired folks. i think the beach sand is the way to go. AND your vids are great ! Keep them coming !
Thanks for this, I've just built a solar kettle from a used evacuated tube, copper microbore pipe and kiln dried sand. Boils water instantly! Never would have thought of using sand.
Thanks Ian,very informative, I live in Ireland, I don't think my solar tubes will ever explode!
I'm very glad that you made this video, I'm from Bulgaria, here we have five months of winter and the temperatures are up to -15°, sometimes it reaches -20. I have four collectors that have a built-in boiler. Now I'm going to try one of these with the quartz sand to fill them up and see what the difference is in the winter.❤
Very nice video and this explains all you need to understand about evacuated Navitron tubes. Many thanks from the UK. Dry fine sand is available here from our builder's merchants, mainly used for block paving infill.
good safety info Dan, Thnx for sharing your insight.
so glad your making videos again
Good one Dan, many thanks from Lismore NSW Australia.
Great video 👍
first one I've seen that actually gives information on how these actually operate. I've inherited components of a solar thermal system but apparently missing the copper heat pipe tubes that go inside the evacuated glass tubes. I couldn't figure out how it was supposed to work, with one end of the glass closed.
Hey Dan, Its convenient for survival such as sterilizing hot water or soups as its already a container. I like that its set and forget for cooking. I boiled an egg to see if it was a good survival cooking tool. I made a video if you want to see it.
extremely useful video.. thanks for sharing this..
Love your video. Teachin the masses whats good to know!
Awesome vid! As usual :) I think the water issue could be solved with a proper manifold seal, but I still like the idea of innovating on the aluminum fins and the wasted volume. Instead of sand, why not try a phase change material, maybe an oil or wax. With your parabolic you might need to find a pcm with flash point above 600F, but w/o a parabolic you could find a more common pcm. A pcm will also leverage the amazing insulating properties of the tubes which are typically wasted at night. Because the pcm's hold many times more heat than air, water, or sand, it could deliver heat into the night hours.
I'd been pondering a combination Solar/PCM hot water system, but hadn't considered storing the PCM inside the black inner absorber tube. It's a really good idea.
Initially it seems dumb coz it's probably the most expensive/space-constrained place you could choose to store your PCM material. HOWEVER, any other place you'd store the PCM will need to be surrounded with thermal insulation anyway, so this way you're getting a double-use outof the evacuated tubes' thermal insulation properties. So really it's a brilliant idea!
Thanks Dan, this is a really cool video that answered more questions than I had when I came here. QUite a fan of this science, and thinking about my next DIY water heater. Your video is pleasant and informational.
Great Information! Thanks.
Those are the water heaters used in Mexico, and it is awesome since you pretty much do not have to use electricity or gas to heat the water up anymore, they are pretty efficient.
Great to see new videos from my favorite diy energy channel.
:-) Thank You!
good video, thanks for the info! I read about these tubes years ago after seeing them at a vendor at a show, great idea to harness the suns heat. SO who makes good tubes? I'm looking to heat my swimming pool and I know these work far better into the cool season than the plastic tube mats people use to heat their pools.
excellent vid, good info and explanation, cheers, great help in finding out how these tubes work.
Nice work, didn't know something like this existed!
Really interesting, thanks for uploading.
Can you answer though, can a tube shatter by just overheating and not thermal shock?
Awesome video clip!! I always learn something new from you guys
great video and good information. Thanks.
They implode becouse the tubes are closed with a plug and then when installed, the solar side is closed loop, creating tempertures in the loop to over 200c. But you are 100% right to say they are the best, as had on my UK roof for 12 yrs, but use all the day time heated solar water into my 250 litre thermal store to heat my 12 radiators during winter months.
Great idea !! Does the sand increase the volume due to heat expansion of material? If so ,then for long term use,it will crack the tube open and imagine that mess on the roof.If no expansion problems..I wonder how many tubes will hold steady steam to turn steam generator and produce some decent power.
Awesome info lookin forward 2 learnin more info
Amazing and really well explained.
this is awesome video, great information and instruction.. thanks..
God bless Dan and his mobile home.
Just got seven 30 tube collectors. Interested to know of any information on the type of fittings etc to use.. Was told that compression is better due to the heat buildup my melt solder if the pumps fails.....also any links to heat dissipation ideas for the summer months cheers Clive
Two options that come to mind for me would be either perlite or ceramic sponge. In either case, is there no boot or deflector to prevent water ingress?
Great Video,,, Thank You and Yours for All the Fat Blessings !!! =) You are Brilliant and Awesome !!! Thanks again Friend =)
Very good. Thanks!
love your stuff Man..,hello to misses..
The problem with using sand as a heat transfer medium is it's going to act as an insulator and the heat will not transfer to the copper heat pipe very quickly and therefore, there will overall be loss of thermal efficiency. You're able to recoup some of that heat at night and that's the problem; the heat stayed in the tube for a long time rather than getting transferred to the water storage tank and therefore a large portion of the heat was lost back to the ambient. A vacuum tube is an excellent way to prevent conduction and convection of heat but radiation still occurs.
The problem shown regarding the water hitting a hot tube and causing an explosion should not be a problem with a properly designed tube collector. The top of the tube is inserted into a manifold which uses a gasket to prevent any water from the elements getting in. Rain or not, the tube will be safe.
Thank you, have you got a simple reflective design to improve efficiency?
Nice video. I have a question. My collector has 20 of these head pipe tubes. After 7 years of operation, I found that some tubes on the surface are colder and others are warmer (you can keep your hand on them). The glass tube is mirror-shiny (which should signal the presence of a vacuum - the tube is OK).
Don't have experience with why some tubes are warmer and others are colder? It cannot signal a fault (media leakage) inside the unseen tube. Does it not transfer heat to the collector and therefore the heat is transferred to the glass tube?
Dan I was thinking why not building a solar cooker that uses tubes? If the temp gets high enough can't the steam be used to generate electric?
Sill going strong mate. Use some parabolic dishes to heat up a massive heat sync.
Very useful! Had no idea, thank you!
Hey Dan why couldn't one just use the copper pipe to run directly into each evac tube and connect at the top? Would it not be more efficient to have the heat from inside the solar tube transfer direct into a copper pipe filled with water instead of heating just air inside of the tube that in turn heats only a small portion of the top of the copper pipe?
Awesome vid as allways!
Great information
Dude make a company with sand tubes !! Nice work amazing
Great idea using sand instead of the metal fins to keep the heat in longer after the sun sets. Just curious, did you measure the total weight differences of a tube with the fins versus a tube filled with sand?
The sand adds about 5-6 pounds for the large tubes and 1-2 pounds for the smaller tubes. The only difference is handling. When filled with sand, the weight stress on the continuously formed glass connection is greater so do not set them down hard or with force. Other than that, they work the same in terms of structure. The sand has been a very good alternative. I have one large tube in the shade and the condenser (tip) reaches 135 ˚F with no direct sun exposure after only 2-3 hours on a sunny day vs. close to 300˚ F in direct sunlight. Thank you for the nice comment and question.
Very cool and informative
Sometimes I write a comment and then proof read....Glad I do! God bless,
I think you need to consider the heat transfer rate of the sand. Seems to me it would be slow at getting the heat through to the copper pipe.
Exelent video, thank you bro
great vid
Thanks. You taught me a lot .
Dan - this is fantastic!! We are in Northern Nevada and I wonder how much more efficient this would be!
HI man! great explanation!, do you know were I can buy the tubes ? you diy the collector?
miss your videos wish you would do more videos again
he stopped?
We have a 22 tube evacuated solar hot water system in Australia, it provides us with extremely hot water for 10.5 months of the year with the Electric booster element turned off.......315 litre storage tank A few weeks of boost is acceptable... :)
Hola excelente demostración Me gustaría saber si eso es arena de playa la que tú utiliza en el tubo Y después le echa agua eso es arena de playa
Excellent video
nice experiment! really usefull
Vaseline is it a good heat storage medium.. to pump when it is hot.
I wonder if ground soapstone or a soapstone cylinder that fits inside the evacuated tube would be more efficient than beach sand?
I have the style with no heat pipe and a copper coil inside the tank. I had to put a hot water recirc pump to keep it from boiling in the summer. The pump allows the hot water to be stored in my 40gal electric water heater tank. I'm on my 2nd unit. In the summer it provides all the hot water for us, in winter it acts as a preheater and allows me to run my electric twice a day for 2 hours to save on electric cost. I use no reflectors.
Sand...Great idea!
Nice.
Damn i wish he showed how heat transfer is done those top pins to the main water line.
No-nonsense guy. Interesting info.
Clear explanation!
thanks great video
Thank you Mr. Dan. Thought on useless other wise desert sand?
I think it would be cool if you did something on an electro magnetic harvester. I saw a video where someone had made one and it harvested like radio waves and was able to power a strip of christmas lights without a battery.
wow...very interesting!
nice video.
one of these tubes might be able to run a sterling engine without the need to constantly re-focus a concentrator on the displacer piston, which has always been the bane of a solar run sterling engine.
I realize this has been several years.. But have you considered mixing some carbon black in with the sand?
This is the very good information about green energy
Thanks for shareing
I recommend a petrol oil or maybe some sort of very high smoking point oil as a medium, maybe in tandum with the beach sand? Just need to make sure its not easily flamable, maybe a simple cap would be enough to keep oxygen out
great content thanks
فديو رائع ممكن ترجمه باللغه العربيه لتزيد الفائده شكرن علي المجهود الرائع
Educate Mr leader, when installing these, do you fill them up with water first then connect then to the manifold or no water goes inside the tubes.
What do these cost? Any chance of buying used? I could use about 6-12 maybe more. Can they make steam? Well I guess not useful anyway. Because of the pressure.
Imagine a train totally lined with these tubes. On a sunny day, could it feed a special steam loc enough to really go? And into the night, from the thermal mass? Trains tend to be fully exposed to the sun, most of the time. At least here they are. Few tunnels, rarely a building to cast a shadow. Trees do happen, to a degree.
I was thinking about the same thing. I may need to build a small steam engine to power a generator. I was also thinking off grid water heater, room heater. with a radiator placed somewhere in the shade to strip off excess heat if necessary. I must order some of these tubes.
So eine Anlage habe ich schon seit vielen Jahren !
These are similar to an idea I had within a system for desalinization + energy generation, wherein seawater is pumped through a similar tube that is in a parabolic solar collection trough. The steam is then used to generate electricity, which would power the pumps and such, then the freshwater is condensed. This would result in 3 salable products; sea-salt, fresh water, and electricity. I'm sure I will never get around to pursuing this idea, so I'll just give it to the internet. :)
You do not increase the efficiency using one of those vacuum tubes with a concentrator on them. Efficiency will be probably almost the same what you do is just increase the collecting area. Having sand as thermal mass inside the tube has no benefit. Sand by volume has just half the heat capacity of water so is of no use to have sand inside the tube. Sand is also a fairly bad thermal conductor so the aluminium fins are the optimal solution.
Solar PV panels will take about 2.5x more area for the same amount of power but they will cost about the same as solar evacuated tubes at this point in time. So I will fully heat my house with electricity from PV panels since it will be the least expensive form of energy and the energy for the heating part will be stored in thermal mass in my case a large 14cubic meter concrete slab that can store about 100kWh of energy while keeping the floor temperature at more than acceptable temperature.
There are huge advantages to PV panels for heating like no pipes with hot fluids and pumps and there is no problem if you have excess unused energy no need to divert that as with solar tubes so that you do not damage the installation or cover the tubes.
The down side is that it takes 2.5x more space as I mentioned before.
Goes to show that if it were optimum, the manufacturer would have designed and shipped it that way.
That is correct efficiency is NOT increased by using a concentrator BUT, what is increased is the ability of that vacuum tube to collect sunlight, hence energy.
Sand will not increase pressure inside the tube!
How can PV panels take 2.5x more space as they are 10x less efficient? From a 10sqft you can harvest 1kWh of heat or 100W of energy on average sunny day and with average gear. I agree there's top of the range PV panels that can do 3X as average thermal ( annually!) but you have to ask NASA to sell you some.
Less effective three times four. No, not ten times. Solar panels have an efficiency of 17%
Which sand you have used over there and where I can find that ..... I am from India doing some research work on tubes so I need your help ... Please help me out .... Will be waiting for your reply
"Beach sand" its from the beach. Any sand will work about the same.Use Sand
Jeff Stanton hey in which month you have done this experiment and your location. I need this just because I can find solar radiation of that mouth. So please help.
Dan, the tube that was filled with sand and then it's temp was taken 3 hours after the sun went down, for how long was that tube out in the sunlight?
3 hours, i imagine
I live in the UK they work well would recommend to do but your plumbing needs to be able to take this type of system.
Like a BOSS!
awesome!
Considering that the sand is still within only 10F of the aluminium fins, it has no advantage there.
So the main advantage to the sand is that it acts as a layer to soak up (& flash-boil away) any ingress water before it can get in contact with the hot black glass, yes?
Just wanted to add on the sand in evac tube, what you win in the evening as delayed heat- you loose in the morning as heat is delayed. Most likely you loose more than you win as the accumulated heat cool off slowly - there is lots of energy lost in the dense sand as it falls under useful the temperature. Every morning you will start with cold sand. Cool feature with sand but not adding energy.
I was wondering how big temperature inside it can handle, becaouse i consider to make it working only on air. Two posibility exchange air inside (use only glass tube) or solder extra coper radiator and use with heat pipe. The reason for that is to use it as direct air house heating (as suport for main heater) What You think about that?
Lte's see you do one filled with magnetite (Fe2O3) as it is a susceptor! Will send you some, what is the volume you need?
These tubes use the 126.22 hertz frequency of the sun to generate heat?
Hello, want to ask, if solar glass tube for water heating is hot from outside, does it mean it is no good any more?
Can this be used to head a greenhouse in the winter?
Hay could you not use gallium in place of water and pump that hot liquid metal through copper coil heat exchangers to both heat water and operate thermal electrity generation?
I wonder if they consider cavitation it's a big concern with hydraulic systems
Probably the most efficient way to extract energy from sunlight is to focus it into a black body enclosure such as an empty sphere with a small opening & with matt black walls on the inside. This will retain a large proportion of the energy within the sphere. Run water through a pipe & focus the sun onto the pipe in the middle of the sphere. Boil. Steam. Tesla turbine. Generator. Sun tracking Fresnel Lens heliostat.
Hi Dan
Did you try salt yet?