Stroller wrote: ↑Tue Apr 30, 2024 11:01 pm
Tom Booth wrote: ↑Tue Apr 30, 2024 3:51 pm
I came across two opposing theories. One says basically heat is a fluid and runs through a heat engine like water. The other says heat is energy and basically "disappears" inside the engine, as it is converted to work.
If the latter is true, then it is really not necessary to design an engine around the idea that you MUST make ample provision for getting rid of 90% or the heat you supply to the engine.
I don't know, but intentionally throwing away 90% of the stuff that a heat engine is supposed to run on didn't make a whole lot of sense to me.
The engine doesn't run on heat. It runs on
differentials in heat,
True that has been the prevailing blurb for a long time now. However, from my experience, observations and experiments, it looks to me like that is misleading and just plain wrong.
Heat engines actually do run on heat.
and therefore pressure.
And what is "pressure"?
Pressure is the activity of the gas molecules pressing, bumping, colliding with the container walls. Heat input increases that activity.
The bigger the differential in pressure throughout the cycle, the more driving force on the piston.
The "pressure throughout the cycle" is not quantifiable at any one point in time of the cycle.
The pressure difference at any one point in time is between internal pressure from heat addition and external atmospheric pressure, not anything to do with the presence of a cold piece of metal or supposed "sink".
OR
pressure reduction of the working fluid which again at any point in time, alters the pressure between the working fluid and
outside atmosphere. Nothing to do with a cold piece of metal, but due to the removal of internal energy by either one or both of two methods. Heat removal to a "sink" or work output.
I've found through experiment that work output alone is sufficient even when heat "rejection" to any "sink" has been eliminated. In fact, eliminating the "sink" almost invariably increases RPM and power output rather than reducing it, as might be expected due to heat buildup.
The heat buildup doesn't happen, or is beneficial, if there are no material constraints, like melting plastic parts.
Also, where possible, work output is obviously preferable to "throwing away" the engines fuel supply.
Therefore I'm exploring methods for reducing unnecessary heat loss, along with ways to maximize work output.
And yes, Virginia, making the cold side cooler will increase the differential.
Making the cold side cooler may logically seem to have the effect of increase the pressure differential, given the prevailing false theories. but that is not really the case. Expanding the gas with heat increases the pressure differential. The presence of a cold piece of metal does not contribute to that process. Often it can work against it, cooling the gas you are trying to heat and expand.
With sufficient cooling due to work output there is no need for additional cooling through heat removal.
The progress of the science of heat engines has been hampered by too many assumptions stemming from old obsolete theory and not enough critical observation and experiment.
Most of the simple experiments I've been doing in just the past few years had NEVER been done before. They should have been done 200 years ago.
But you know all that, and you're just being provocative and muddying the waters for the fun of it.
Not true.
Seems to me that the important question for those who count the cost of input energy (propane ain't cheap) is whether the frictional losses in bearings and pump seals, eddy currents in dynamos etc mean that you'll lose more than you gain by installing a flywheel driven cooling system.
Work output is not a "flywheel driven cooling system" if that is what you are implying.
If you have a practical use for a Stirling engine, it may make sense to supply the required energy externally (by periodically lifting a bucket of cold water into a gravity fed cooling system for example).
As I said, drowning a heat engine with buckets of cold water is counter productive.
Better to incorporate some form of load balancing. Reducing heat input when work output diminishes while driving a variable load, and increasing heat input as the work output increases.
Applying excess heat and then using water to cool the engine to remove the excess heat is just wasting energy unnecessarily, and is one of the reasons Stirling engine development has in some ways gone backwards, largely due to the introduction of the Carnot theorem fallacy, that insists that most of the heat, or nearly all of it, MUST flow through the engine and be taken out to a "cold reservoir" rather than being fully utilized.