> A pet scheme of mine is a refrigeration unit run by waste heat.
> Someone's already
> done it & I don't know about it, probably.

More on Vuilleumier machine.
These are simple enough that most could build one "at home"
NO compression pistons.
Pressure rises modest.
NO seals (except to move displacers if not driven through wall etc).


Discussion with diagrams

 http://www.solarmirror.com/fom/fom-serve/cache/44.html

VM heatpump patent
    http://www.patentstorm.us/patents/5483802.html

Free piston VM refirgerator
Abstract
            http://www.sciencedirect.com/science?_ob=3DArticleURL&_udi=3DB6=
V4R-3Y6PFV3-17&_user=3D10&_coverDate=3D01/31/1995&_rdoc=3D1&_fmt=3Dhigh&_or=
ig=3Dsearch&_origin=3Dsearch&_sort=3Dd&_docanchor=3D&view=3Dc&_searchStrId=
=3D1630443438&_rerunOrigin=3Dgoogle&_acct=3DC000050221&_version=3D1&_urlVer=
sion=3D0&_userid=3D10&md5=3De425429c9df5484068905a90337a1fa6&searchtype=3Da

Paper. Physico mathematical models
Gives V' history
    http://www.agir.ro/buletine/551.pdf

Brief description and picture
Pages 140-143
Good

http://books.google.co.nz/books?id=3D5dw85Z-<http://books.google.co.nz/book=
s?id=3D5dw85Z-cSQ8C&pg=3DPA140&lpg=3DPA140&dq=3Dvuilleumier+machines&source=
=3Dbl&ots=3DBzzH9VfGj5&sig=3D2qRqMNf4AZJ7IEx6JTMkTvVCcxI&hl=3Den&ei=3DYxlMT=
eHbNILSsAPh9cyVCg&sa=3DX&oi=3Dbook_result&ct=3Dresult&resnum=3D5&sqi=3D2&ve=
d=3D0CDYQ6AEwBA#v=3Donepage&q=3Dvuilleumier%20machines&f=3Dfalse>

Well known Japanese Stirling  site
Book
Regenerative Thermal Machines
(Stirling and Vuilleumier Cycle Machines)
for Heating and Cooling

 http://www.bekkoame.ne.jp/~khirata/book_ref/index_e.html

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