Talk:MHD generator
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[edit] todo
- Done:wikilink elements and pivotal words in sentences
- Done:unify terminology of 'tube' 'pipe' 'channel' 'cylinder' (I used the terminology of the Messerle reference).
- have others help with grammar and wording ...
- Done: look for an 'efficiency' for throughput for coal power plants (from amount of energy in fuel to amount of electricity produced from same fuel) (USed the Messerle reference)
- efficency of nuclear power plants from amount of fuel consumed to amount of energy produced.
- Done, sort of...: do the math to verify efficency of MHD generator ... 10 to 20% came from the babelfish german version and needs to be verified. (I didn't do the math, I shamelessly imported Messerle's results, whcih were from actual experiments).
- (Oops; I'll try to add it) please check: power generation example lacks any mention of a magnetic field, isn't this required?
- Comments by Ray Van De Walker 19:34, 19 March 2007 (UTC)
The piece I couldn't fit in anywhere that merged from MHD dynamo; "In some cases, anomalous magnetic field production in the Madison Symmetric Torus reversed field pinch has been shown to be caused by the MHD dynamo."
I've tried to fix this up as best I can. To the best of my knowlage there must be a magnetic field at all times for this to work. cc24.137.78.34 21:20, 4 February 2006 (UTC)
[edit] Current developments?
I can't find any current examples of MHD generators in use for production of electric power. It's my impression that this ship has sailed...that the steady development of, eg. combined-cycle gas turbines with steam bottoming cycles have gained all the efficiency advantages that were once supposed for MHD, without the heart-breaking difficulty of trying to make a gas conduct electricity. Can anyone point at an MHD experiment more recent than the early '70s, which is all my "Standard Handbook for Electrical Engineers" has ? --Wtshymanski 01:50, 21 May 2005 (UTC)
I have to agree with you that this hasn't really caught on, but I am not an authority on the topic. It seems to me that the there could be a revival however by adding some new technology. The bit about the alkaline salts and plasma generation seems a bit out of date however. With the recent developments in cold one atmospheric glow plasma these would seem to be unnecessary as they are supposed to be quite efficient, although I could be mistaken. I have heard of one being used backwards once on an industrial scale, but that was for a niche application pumping liquid metal in a refinery or something along those lines. Also, shouldn't the formula about how much energy can be extracted include a variable for the strength of the magnetic field? The MHD propulsor formula used in the real world is (thrust)= (current) X (magnetic field strength) X (the distance between the electrodes) cc24.137.78.34 21:35, 4 February 2006 (UTC)
- Being an enthusiast, I had a more recent reference work, the Messerle reference. I wrote the more recent history from that. I hope it's helpful. I bought Messerle some time ago, and I was surprised to find that it is not available at either A Libris or Amazon. However, many research libraries have copies, because many subscribed to the UNESCO energy series. Ray Van De Walker 19:38, 19 March 2007 (UTC)
[edit] endothermic?
The article implies several times that thermal energy can be absorbed and transformed directly into electrical energy. I have checked out a couple of books to investigate this phenomena and cannot find a reference to an endothermic reaction. Indeed the closest that I have found is from "An Introduction to Magnetohydrodynamics" by P.A. Davidson says, referring to an MHD generator, "In this case we induce current, but at the cost of a pressure drop. We are converting mechanical energy into electrical energy plus heat, and such a device is called a generator." (pg 154). I have seen no other reference to an endothermic event. The cooling that occurs as stated "MHD generators typically reduce the temperature of the conductive substance from plasma temperatures to just over 1000 °C." seems more to occure by dissipating the heat over a larger surface area, such as water-cooling engines CPUs etc. If a cooling does occur can someone reference it in a book, or at least explain mathematically the physical explination. Thanks
[edit] generator types?
I was surprised to find no mention of the different generator types, so I added that information. The Faraday generator has been obsolete for more than forty years. I believe the AVCO Mk. V (1965) was a Hall generator. Ray Van De Walker 19:41, 19 March 2007 (UTC)
