Stirlingengineforum.com

While browsing around the internet for engine stuff related to internal to external combustion engine conversion, (nothing much to find really, IC to steam mostly), I came across this article/idea:

The article calls it an "Integrated Internal & External Combustion Engine"

More like a combined IC + Steam engine.

The basic idea is to use the massive amount of waste heat from an IC engine to boil water to drive a steam engine.

As many times as I've had a car engine overheat, blasting out steam from the radiator, I'm not entirely sure it is a bad idea.

Some food for thought anyway.

https://contest.techbriefs.com/2013/ent ... otive/3096


Could this idea be adapted / modified for an integrated gas + Stirling engine?

What that diagram doesn't make clear, is what the two parts of the engine are meant to do? If they are intended to be linked to a common shaft, then I would suggest that that is a very bad idea - allegedly simply linking two IC engines to the same shaft is a very big deal, so getting the power output of two different types of engine in sync is likely to be "a trifle tricky".
If they were never really intended to be linked, then its not really a new concept.

MikeB wrote: ↑Mon Jul 04, 2022 8:22 am What that diagram doesn't make clear, is what the two parts of the engine are meant to do? If they are intended to be linked to a common shaft, then I would suggest that that is a very bad idea - allegedly simply linking two IC engines to the same shaft is a very big deal, so getting the power output of two different types of engine in sync is likely to be "a trifle tricky".
If they were never really intended to be linked, then its not really a new concept.

A turbocharger utilizes some waste heat from the exhaust. Perhaps more would be available from the cooling fluid.

What might make using a Stirling, instead of steam, attractive, is the water could be kept below boiling but the heat could still, theoretically be utilized.

Certainly utilizing "waste heat" generally is not a new concept, and the article is from 2013 but it's new to me anyway.

The article does seem to imply that "the 1st and 3rd cylinder-piston arrangements work like a secondary source of power"... On the same shaft or power train of one sort of another.

It is obviously rather vague in terms of actual implementation.

Steam driven pistons would be problematic before the engine actually gets hot enough to produce steam. Also, the continued use of a radiator as pictured would seem to defeat the overall purpose of heat recovery for power.

Maybe a hybrid electric car could utilize a gas/Stirling combo engine that charged the batteries.

Some stationary power generating station might make better use of such a thing than transportation.

What kind of interests me is what would the successful realization of such a concept mean for the laws of thermodynamics?

Theoretically engine #1 MUST, according to the 2nd law, "reject" a certain quantity of heat, but if engine #2 coupled to engine #1 can utilize that inevitable, unavoidable "waste heat" then is it really so unavoidable?