Search found 91 matches

by Alfista
Wed Dec 27, 2017 8:33 am
Forum: Stirling and "Hot Air" Engine Forum
Topic: small wood gassifier generator
Replies: 11
Views: 4740

wood gasififying stove with Stirling engine, generator and load

The proposed engine that you describe above, something producing 20-50 W is quite similar to one that I built a couple of years ago. It has a 3" piston. At 3 psi (6 hg) it should be producing about 35 W before losses. The video link below shows it connected to a battery powering an 80W load. It giv...
by Alfista
Wed Feb 01, 2017 8:43 am
Forum: Stirling and "Hot Air" Engine Forum
Topic: 2 KWh LTD Stirling Engine
Replies: 28
Views: 20642

Heat and Work

I am sure that someone here on the forum can give you a better answer than I can. In relation to my previous post. Kolin was a physicist and spent a lot of time on this question in his book "The Evolution of the Heat Engine." Although I aspire to improve my understanding of these things, I am confi...
by Alfista
Tue Jan 31, 2017 11:52 am
Forum: Stirling and "Hot Air" Engine Forum
Topic: 2 KWh LTD Stirling Engine
Replies: 28
Views: 20642

Re: 2 KWh LTD Stirling Engine

Hey Alfista, I am very aware of the advantages of PV panels as my folks have them on their house. I am wanting to use a stirling engine partly for the fun of it, and especially because I will be able to do all necessary maintenance myself. So thank you for informing me about the easier method of PV...
by Alfista
Fri Jan 27, 2017 8:22 am
Forum: Stirling and "Hot Air" Engine Forum
Topic: 2 KWh LTD Stirling Engine
Replies: 28
Views: 20642

heat collection for LTD Stirling Engine

Here are a few calculations on heat collection and power production in a solar heated, LTD Stirling engine system. I have been looking at the feasibility of such a system. Without putting too fine a point on it, it is easy to see why such a system must be deployed within a larger, synergistic proje...
by Alfista
Thu Jan 05, 2017 8:50 am
Forum: Stirling and "Hot Air" Engine Forum
Topic: gamma stirling engine scale
Replies: 5
Views: 3675

Re: gamma stirling engine scale

Aviator, you are right that 3.5 psi MEP is no small accomplishment. When M.I.T tested a 6" Rider engine in 1896, they found a Mean Effective Pressure of about 3.48 (psi above atmosphere) on the pressure side of the stroke. Data on modern engines shows much higher MEPs but that is not at all the cas...
by Alfista
Tue Jan 03, 2017 9:15 am
Forum: Stirling and "Hot Air" Engine Forum
Topic: gamma stirling engine scale
Replies: 5
Views: 3675

Re: gamma stirling engine scale

Shaysi, most published plans are oriented to the gamma configuration. My preference has been to work from the plans of Rudy Kouhoupt published by Village Press. Rizzo in his two volume "Stirling Engine Manual" offers lots of detailed information on building but these fall short of what I would call...
by Alfista
Mon Nov 14, 2016 8:28 am
Forum: Stirling and "Hot Air" Engine Forum
Topic: Homemade Engine with Generator
Replies: 18
Views: 11496

Re: Homemade Engine with Generator


Here are a couple of photos of the aluminum piston with cast iron rings. The diameter is 3".

by Alfista
Thu Nov 10, 2016 8:10 am
Forum: Stirling and "Hot Air" Engine Forum
Topic: Plans for a 10kw fresnel lens free piston harwell stirling engine
Replies: 2
Views: 2956

Re: Plans for a 10kw fresnel lens free piston harwell stirling engine

I have never seen or heard of a fresnel lens that large. I believe that the very best case scenario is a lens of 25 square meters, that is calculating 1 kw of solar energy per square meter and a maximum efficiency of 40%. Of course that only addresses the challenge of the heat source. I have seen a...
by Alfista
Fri Oct 21, 2016 5:01 am
Forum: Stirling and "Hot Air" Engine Forum
Topic: Is there a perfect ratio between cylinder size.
Replies: 7
Views: 5865

Clarification

Here is a rough outline : The classic design calls for the swept volume of the displacer to be 1.5 times the (working) volume of the power cylinder. As this ratio increases, the requirement of the temperature differential goes down. Specific output tends to go down as does the rpm range. Engines be...
by Alfista
Sat Oct 15, 2016 2:58 am
Forum: Stirling and "Hot Air" Engine Forum
Topic: Comparison between the power of steam and stirling engines
Replies: 4
Views: 4508

Re: Comparison between the power of steam and stirling engines



thanh-cuibap,
I would like to refer to an earlier post comparing steam and stirling :
viewtopic.php?f=1&t=2073#p9924

and a youtube video of a micro steam power plant :
[youtube][/youtube]




........
by Alfista
Mon Oct 03, 2016 3:39 pm
Forum: Stirling and "Hot Air" Engine Forum
Topic: 1st post, Never built anything before, have a few questions on Stirling LTD engines
Replies: 15
Views: 8036

Solar Fluidyne Stirling Wasserpumpe



"The drinking bird" really works on the same principle. It can be made to operate at a very small temperature differential. Here is a Youtube example, a Solar Fluidyne Stirling Wasserpumpe pumping very nicely !

[youtube][/youtube]


by Alfista
Sun Oct 02, 2016 12:29 pm
Forum: Stirling and "Hot Air" Engine Forum
Topic: 1st post, Never built anything before, have a few questions on Stirling LTD engines
Replies: 15
Views: 8036

FLUIDYNE

As I have read and reread your posts I have come to think that you would be much better off using a fluidyne to drive an airpump, the airpump being responsible for the oxygenation. A fluidyne is only about 100 times simpler to build than the ltd Stirling. It is effective, nearly foolproof to build ...
by Alfista
Sat Oct 01, 2016 5:44 pm
Forum: Stirling and "Hot Air" Engine Forum
Topic: stirling engine my first!
Replies: 2
Views: 2856

Excellent

Excellent Job on your engine !

CONGRATULATIONS !
by Alfista
Fri Sep 30, 2016 11:19 am
Forum: Stirling and "Hot Air" Engine Forum
Topic: 1st post, Never built anything before, have a few questions on Stirling LTD engines
Replies: 15
Views: 8036

questions and focus

With so many questions on such a wide array of topics, it is difficult to focus on the fundamentals. If you are able to focus enough heat over a large enough area, then you would probably be better off with the thermosacoustic engine which I will class as a high temperature differential engine. Kee...
by Alfista
Thu Sep 29, 2016 2:39 pm
Forum: Stirling and "Hot Air" Engine Forum
Topic: 1st post, Never built anything before, have a few questions on Stirling LTD engines
Replies: 15
Views: 8036

suggested reading

DrJekyll, you are ready for Dr. Senft's book on LTD engines published by Moriya Press. This process is more easily understood through thermodynamics. A rapid heating and cooling of a fixed volume of air creates pressure and vacuum alternately. These forces are then captured in the "power cylinder"....