Author Topic: Cup of Tea Engine  (Read 548 times)

Offline Robert Hornby

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Cup of Tea Engine
« on: February 18, 2022, 02:37:03 AM »
Some 25 or so years ago I made a cup of tea engine and subsequently sold it (that is another story). I wish to build another one but cannot find the original plans, so I am making it from memory. Please help with the ratio of displacer volume compared with power cylinder displaced volume, or is it not too important? By the displacer volume I mean the volume of the cylinder minus the volume of the displacer.
Robert
Age and treachery will always overcome youth and skill

Online Hugh Currin

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Re: Cup of Tea Engine
« Reply #1 on: February 18, 2022, 03:56:51 AM »
Robert:

I believe the displacer to power cylinder volume is dependent on the temperature differential being exploited. The Low Temp Differential engines have a large displacer compared to power volume.

I'd suggest you look at some of Jan Ridders designs . He may even have a design you could use directly. I've found him very responsive in sending drawings.

I'm making (turned into a very long term project) of a version of his "Egg Cup Stirling". The build log is on this site somewhere.

Let us know what you find. Thanks.
Hugh

Offline PJPickard

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Re: Cup of Tea Engine
« Reply #2 on: February 18, 2022, 01:20:02 PM »
There is this too:
http://animatedengines.com/ltdstirling.html
James Senft has designed many Stirling cycle engines

Online Jo

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Re: Cup of Tea Engine
« Reply #3 on: February 18, 2022, 02:17:13 PM »
Please help with the ratio of displacer volume compared with power cylinder displaced volume, or is it not too important? By the displacer volume I mean the volume of the cylinder minus the volume of the displacer.

Low delta Temperature engines, like the "cuppa model engines", typically have a displacer cylinder differential swept volume of about one hundred times greater than the power cylinder.

Jo
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Offline Robert Hornby

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Re: Cup of Tea Engine
« Reply #4 on: February 19, 2022, 10:30:41 AM »
Thank you very much for your inputs they help tremendously.
Age and treachery will always overcome youth and skill