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Author Topic: Whispergen in real life application  (Read 29833 times)
stuartiannaylor
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« Reply #15 on: November 25, 2010, 02:28:36 AM »

Just wondered if anyone knew what the temperature difference between the hot and cold feeds on these?

Thanks

Stuart
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Ivan
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« Reply #16 on: November 25, 2010, 03:25:42 AM »

I don't but I expect it is high - 200C or more.

The bottleneck is the fact that it is only designed to produce 1kW electrical output. The rest of the boiler output is heating only without any attempt to extract electrical energy
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knighty
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« Reply #17 on: November 25, 2010, 11:08:11 AM »

is that a typo for 20'C ?
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stuartiannaylor
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« Reply #18 on: November 25, 2010, 01:19:50 PM »

200C is much lower than I expected actually. I was having one of those could I steal the sterling engine and use it in a better ways thoughts last night. I did a liitle be of research and was expecting that it could be as high as 700C even more ...

200C is really interesting though. Please don't comment here "A better way for retro fits than common flat panel installs"   http://www.navitron.org.uk/forum/index.php/topic,12222.0.html

At the end of the thread I posted some details about a CERN flat plate evacuated design have a look as the FUTURE possibilities are there to capture 200C and above.  genuflect please I got a kicking in there to certain respects that it is to expensive, not possible ...
This is just one of those what if scenario's but if you had an oversizied collector array to provide 100% winter DHW then instead of stagnation in summer you could theoretically drive one of these.

I was looking for a face slap emoticon to being me back to earth. Saying that when it comes to CHP and those temps then a steam turbine provides much better possible ratios of energy usuage against prodcution.
Stuart
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Ivan
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« Reply #19 on: November 27, 2010, 03:32:19 AM »

Of course, you can use any heat differential to drive something producing rotational power and thus electrical power. Stagnation temperature is a measure of a panel's ability to perform at high temperature. but you also need kW input. More area = more kW. Stagnation temperature is where power in = heatlosses out. So a panel will produce virtually no energy under stagnation conditions as the input is balancing heatlosses. It's slightly different in heatpipe systems because the heatpipe stops circulating when its contents are 100% vapour so this is the stagnation temperature, even if the tube continues to get hotter. Put a vacuum tube in front of a parabolic reflector and you'll get even more heat.

If you haven't got enough heat for steam, you can use lower boiling point organics - LPG, alcohol, ammonia etc ('rankine cycle')

I've run vacuum tubes at 150C during the summer, producing electricity from TEGs, incidentally.
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Baz
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« Reply #20 on: November 27, 2010, 11:04:52 AM »

TEG?
google didn't come up with anything needing 150C, just a few organisations probably making hot air of their own.
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knighty
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« Reply #21 on: November 27, 2010, 12:28:46 PM »

google peliter Wink
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stuartiannaylor
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« Reply #22 on: November 27, 2010, 01:36:20 PM »

"200C is really interesting though. Please don't comment here "A better way for retro fits than common flat panel installs"   http://www.navitron.org.uk/forum/index.php/topic,12222.0.html

There is a panel that could produce those temperatures but its a CERN thing that is under evaluation at the moment. Ivan doesn't like it at all, and thinks it is a white elephant.

Its strange though as many of his arguments to application might hold true and then in other threads he mentions peltier devices. I know nothing of your experiments in using peltiers as TEGs but in terms of cost that is a huge white elephant. Unless you are doing something very small scale even running a pump would be hard work.

Saying that do you have any more info on what your doing as its sounds interesting and I have an open mind to any form of generation scheme.

Stuart
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stuartiannaylor
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« Reply #23 on: November 27, 2010, 02:04:03 PM »

I guess and I will for Ivan's benefit stop mentioning the CERN evacuated plate provide a solar system for the engine of the whispergen.

If you had some direct feed evacuated tube feeding thermal oil, so you don't get that evaporation problem. Then if you sat a heat exchanger on the top of one of these then it would be interesting if all but an experiment.
My thought path has been working on the idea of some form of solar CHP where during high solar activity you generate and towards the end of the day or periods of low collection switch to DHW.
Just an idea and I really hope the wispergen takes off as to be honest personally the full unit is of not much interest to me. The availability of stirling engines in the form of spares and 2nd hand units does.
I have seen a few units like the whispergen such as BAXI and they all seem to quote exactly the same specifications. I do hope they are all just rebadging the same unit as that will increase that spares pool.
If you where recycling a loop through a heat exchanger does anyone know what the temperature difference of the input and output would be. My maths isn't all that great but is it at least a long shot ?
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Ivan
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« Reply #24 on: November 28, 2010, 02:13:27 AM »

Mention the CERN panel as much as you like, but you are right,  I do indeed think it's a white elephant. I agree it will work, and I can believe the temperatures it achieves, but I also believe that overcoming the 20tons of atmospheric force against the face of the panel will make it far too expensive to be practical (for the same reason that hot water cylinders, submarines, vacuum chambers etc are always round and not flat-sided.

My solar tubes-TEG experiments were also a white elephant. I did it for fun more than anything else (and the fact that as far as I know noone had demonstrated it previously). With a very crude experiment, I generated around 3-6Watts of electricity from 4 vacuum tubes. It could easily be improved to probably about 100W, but it would not come close to the cost of PV. It had some advantages eg it worked in partial shade, whereas PV doesn't fair well in partial shade. I believe it would be straightforward to develop a domestic solar thermal system which generated enough electricity to run the pump....but the cost would be substantially increased over a standard system. Do a search on the forum to find the details. I can't remember where it's located - search for TEG Radio or solar TEG or similar.

Navitron installed a solar thermal system somewhere near Oakham which heated  oil to 150C for an agricultural process. Give the office a call and ask Tim who used to work for the company - he should be able to tell you all about it.

There's a really interesting American Rankine cycle engine with a unique valve arrangement (the usual power-sapping component) for recycling the cooled condensed fluid. I can't remember what it's called. I've posted the details here in the past. Unfortunately, the company seems to be more active in seeking investors than developing their idea into working products.

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stuartiannaylor
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« Reply #25 on: November 28, 2010, 03:06:10 AM »

Thanks Ivan as that is of interest.

I have a little bit of inheritence money in my back pocket and it is going to stay there for a while. After finding this forum I have gone a little bit crazy as the wealth of knowledge on here is just superb. I think I will do what I usually do. Grab as much infomation as I can, get all excited and I really should grow up. Then I will prob sit back and see if anything new comes up. If I am still thinking yeah I will give it a go in six months or a year. I shall keep you all posted.

Its been really great just to throw some idea's on here and honestly I have listened. One thing occured to me and if any one is throwing stones then I will not be near those CERN panels. I bet they can implode with some effect Smiley

Thanks for everybodies posts and I apologise for mine ... Now sodium-sulphur batteries mmmm.
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Ivan
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« Reply #26 on: November 28, 2010, 03:22:01 AM »

One of the criteria of the standards required for the UK and European markets is that they have to withstand quite a severe impact without shattering. I was surprised that CERN did not have this for their panel - even more important when you consider how big the bang would be if they were broken!
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A.L.
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« Reply #27 on: November 28, 2010, 01:55:21 PM »

Hello stuartiannaylor,

Ivan said
Quote
There's a really interesting American Rankine cycle engine with a unique valve arrangement (the usual power-sapping component) for recycling the cooled condensed fluid. I can't remember what it's called.

I think this is what he was referring to - https://matteranenergy.us/animation.html
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Ivan
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« Reply #28 on: December 05, 2010, 01:21:27 AM »

That's the one. I first found the site several years ago. I note that they are still 'looking for investors'
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peterboat
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« Reply #29 on: November 28, 2018, 10:31:01 PM »

Just found this thread, I am on my second whispergen, mine are the original ones that run on kero/diesel, My first did six years and 6000 hours it was a 12 volt dc model, it was sold on in full working order. My second is a 24 volt model ans I am sure it will be as good as the last one, they really are a very good piece of equipment that nothing else can do as well. This one was a bargain it cost 400 quid brand new ex MOD, I bought four and sold the other three as full kits at a healthy profit. I must add that I live on a Dutch barge and am off grid so everything has to be up to the job or its history
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