Low Tech Isobaric Engines

[matt brown]

I never let my schoolin' interfere with my education (Mark Twain)

I've always studied off the wall stuff, especially when low tech. Here's a modern rehash akin Ericsson cycle...

IE setup.jpeg (67.7 KiB) Viewed 1421 times

from https://encontech.nl/isobaric-expansion-technology/


Here's 2 papers on this isobaric scheme, 1st from 2018, 2nd from 2022

https://www.mdpi.com/1996-1073/11/1/154

https://ris.utwente.nl/ws/portalfiles/p ... presso.pdf


At least Fool and Vincent should find these amusing, but Vincent, did you see the wiki article on isobaric process

https://en.wikipedia.org/wiki/Isobaric_process

where a couple xlnt graphics include some of my favorite values...

isobaric_1 wiki.png (39.06 KiB) Viewed 1421 times

isobaric_2 wiki.png (38.42 KiB) Viewed 1421 times

and just to round out the tease, here's the original compound drive scheme that was making the rounds nearly 10 yrs ago

compound drive.png (9.71 KiB) Viewed 1417 times

[VincentG]

Talking strictly about single cylinder arrangements;

The mass on the piston is a good demonstration and akin to what I'm up to but it's not isobaric in practice unless expansion is carried out so slow, whats the point?

IOW, with any real load accompanied by rapid heat addition, is it really isobaric?

[matt brown]

True, it's kinda like the phantom isothermal process where an isobaric process requires even more input/output than similar isothermal process. I find it amusing, but they've glossed over basic Rankine issues. However, still nice to see someone thinking outside the box...

[Fool]

Every thread mentioning the Ericsson Engine should have the following link.

https://en.m.wikipedia.org/wiki/Ericsso ... 0processes.

What I find interesting about the Ericsson is that the compression is separated out from the expansion. Yet combined with double action, kinda sorta. It's, kind of a, combination air compressor and air motor, where the air is heated by a regenerator on the way into the expansion work output piston cylinder, heated in that cylinder, and heat is saved on the way back out.

I'm thinking it would work if it were powered from a standard air compressor. It might even run heated or not, just from air pressure, of course at lower power out than in for unheated. It is completely separating the "back work" from the power out forward work. If nothing else it would be a great learning tool. It could be useful to custom build a compressor to experiment with adiabatic verses isothermal Tc compression to see which requires less power/energy.

The air powered cars seem to skip the idea that if fuel were used to heat the air going through the motor is would produce more power. Hmmm, drag racing, LOL.

The Ericsson is kind of half Papin half Stirling/Carnot.

[VincentG]

I've been experimenting with a Gamma chamber as an air compressor. My epoxy chamber can crank out over 2psi from hot water, so if a 300-600k chamber can reach 10psi(I'd bet on it) than a continuous hot air supply could be had for a simple steam type engine.

[Fool]

And maybe a bit more.