Disappointing

Discussion on Stirling or "hot air" engines (all types)
Aviator168
Posts: 308
Joined: Tue Feb 08, 2011 2:29 pm
Location: Brokeville, NY. USA

Disappointing

Postby Aviator168 » Tue Jan 31, 2017 7:52 pm

Anyone else can verify this? I did some calculations and they made sense.
http://file.scirp.org/pdf/ENG_2015121717392471.pdf

Note. They are talking non-pre-heated air. A professional stirling engine will always has a pre-heater for air.

Trevor
Posts: 170
Joined: Sun Nov 06, 2016 4:07 am

Re: Disappointing

Postby Trevor » Wed Feb 01, 2017 2:51 am

Well, look at this way Aviator - Why are they now making cars and generators from heated air sterling engines. Doesn't make sense!!!!
Trevor

cbstirling2
Posts: 117
Joined: Sat Dec 17, 2016 9:35 pm

Re: Disappointing

Postby cbstirling2 » Wed Feb 01, 2017 3:05 am

Who's making cars??
CBStirling2

Trevor
Posts: 170
Joined: Sun Nov 06, 2016 4:07 am

Re: Disappointing

Postby Trevor » Wed Feb 01, 2017 3:33 am

From what I've have seen advertised on TV - It's Japan, going to introduced this year. Also in one of the sterling LTD Papers "An Introduction to Stirling Engines by James R. Senft" It was a model P-40 Rider type engine with compressed hydrogen at 2200psi with a piston displacement of 492cc. The engine produced 72Hp at 4000 rpm. After these were tested/trialed for 12 months they were scrapped and never to be seen again. These were also built by Toshiba.
Trev

Trevor
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Joined: Sun Nov 06, 2016 4:07 am

Re: Disappointing

Postby Trevor » Wed Feb 01, 2017 4:21 am

High CB - Here is a thread on U tube about hybrid car using Sterling and Electric

Aviator168
Posts: 308
Joined: Tue Feb 08, 2011 2:29 pm
Location: Brokeville, NY. USA

Re: Disappointing

Postby Aviator168 » Wed Feb 01, 2017 7:36 am

Where is the link?

Here is about external combustion engines. The heat can be re-capture many times. You just have make some compromises, especially in size.

One of the biggest challenges of stirling engine is the burner and the outside heat transfer area. Just do some exchanger calculation and you will what I mean. The resistance to heat transfer is dominated by the burner. To increase heat transfer, you need to pressurize the burner and increase hot air movement velocity in the burner. Both are very difficult to do. To increase efficiency, you need to re-capture exhaust heat, at 1 bar, very difficult to do also.

Ian S C
Posts: 1981
Joined: Thu Dec 02, 2010 5:15 am
Location: New Zealand

Re: Disappointing

Postby Ian S C » Thu Feb 02, 2017 2:04 am

The university in your first part of this thread have another site I seem to remember in which they constructed (rather crudely I thought) a Stirling Engine using a V twin compressor, they seemed to wonder why it didn't work too well.
Ian S C

Trevor
Posts: 170
Joined: Sun Nov 06, 2016 4:07 am

Re: Disappointing

Postby Trevor » Thu Feb 02, 2017 3:04 am

http://www.12news.com/features/texas-ma ... /245941298
Here is one of the threads that I seemed to miss Aviator - Trev

Aviator168
Posts: 308
Joined: Tue Feb 08, 2011 2:29 pm
Location: Brokeville, NY. USA

Re: Disappointing

Postby Aviator168 » Thu Feb 02, 2017 4:10 am

Seen that news a few times. If I am not mistaken, that's a Mod II engine. I will believe his claim when it happens.

cbstirling2
Posts: 117
Joined: Sat Dec 17, 2016 9:35 pm

Re: Disappointing

Postby cbstirling2 » Fri Feb 03, 2017 12:02 am

CBStirling2

Aviator168
Posts: 308
Joined: Tue Feb 08, 2011 2:29 pm
Location: Brokeville, NY. USA

Re: Disappointing

Postby Aviator168 » Fri Feb 03, 2017 7:34 am

All the news came from the same source. If he is going a build a stirling that gets that efficiency, he will have a lot of challenges. Is it possible? you bet. Just some facts. In general, a full size car need 300w per mile, and this is from real world data from many Tesla (X model) owners. My HighLander gets about 26 mile per gallon on the highway and that's about 1540w per mile. You can see that the engine in the HiahLander is at most 20% efficient if the Tesla is 100% efficient which is not. So for him to get > 50 miles per gallon on a midsize SUV, his stirling engine has to get an overall efficiency of > 40% which is very difficult to do if not impossible. However, if he succeeds building a multipass counter flow burner, he might have chance.

Aviator168
Posts: 308
Joined: Tue Feb 08, 2011 2:29 pm
Location: Brokeville, NY. USA

Re: Disappointing

Postby Aviator168 » Fri Feb 03, 2017 4:16 pm

The university in your first part of this thread have another site I seem to remember in which they constructed (rather crudely I thought) a Stirling Engine using a V twin compressor, they seemed to wonder why it didn't work too well.
Ian S C

I missed this.
I guest they had no clue

Ian S C
Posts: 1981
Joined: Thu Dec 02, 2010 5:15 am
Location: New Zealand

Re: Disappointing

Postby Ian S C » Sat Feb 04, 2017 2:26 am

I'v had a look for the site, but can't find it now, but they do have a site where they have built an "improved" TMG with a rubber diaphragm instead of a metal one.
Ian S C

Aviator168
Posts: 308
Joined: Tue Feb 08, 2011 2:29 pm
Location: Brokeville, NY. USA

Re: Disappointing

Postby Aviator168 » Sun Feb 05, 2017 9:28 am

Yeah. How can you based your paper on a TMG, which technically is a toy. With a good counter flow burner, you can get the top end temperature much lower than the exhaust temperature.

Trevor
Posts: 170
Joined: Sun Nov 06, 2016 4:07 am

Re: Disappointing

Postby Trevor » Mon Feb 06, 2017 2:52 am

Hi Aviator (in answer to the car question)
You still can't say they haven't built a car that was practical and had good millage to the gallon - Check out this - "An Introduction to Stirling Engines by James R. Senft" It was a model P-40 Rider type engine with compressed hydrogen at 2200psi with a piston displacement of 492cc. The engine produced 72Hp at 4000 rpm. This is good reading and I haven't found the article in the magazine I was talking about, because I think I gave it to my cousin. If you check out some of the car magazines you may pick up the thread from there.
Trev


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