Stirlingengineforum.com

Hi,
I'm new to this forum and Ill just start by introducing myself.
My name is Darian, I'm a general contractor in Florida, a licensed 100T master captain, a private pilot w/ FAA license and a cultural anthropologist w/minor in ethnobotany.
OK,
I am greatly interested in engines and fuel sources. I have experimented and eventually fabricated a hydrogen generator that actually worked on my car. (2004 Mazda 626)
It increased my fuel economy greatly (40%) among other bennefits. I finally found a design that produced signifigant amounts of hydroxy gas after many failed builds based on other's and eventually my own designs.
I mention this because I was considering a Hydrogen generator that uses water with electrolytes and electrical current to produce a flamable , on demand fuel, to utilize as a heat source for a stirling engine. The most successful generator I have built would create a steady flame (although very high octane) from a 1/4" tube. The heat generated within the hydrogen generator is possibly an even more useful source and more easily controlled. I literally melted pvc tubing during some trials without igniting any gas whatsoever.
In a dingy/yacht tender application or small boat you could also have an excellent heat exchanger by using copper tubing below the waterline or even in the bilge, with the ambient temp water (whatever your floating on) free flowing through this as a cooling source as well. Most oceans, bays, and lakes are relatively cold and obviously transfer heat exceptionally well.
Solar would also be a great heater, such as a rigid inflatable boat like an AVON rib or the like with black hypalon tubes to heat water inside the inflated tubes or even a small solar pool heater design customized for a small boat.
If I'm not mistaken, one factor that greatly effects The Stirling engine's efficiency is the difference in temperatures.
Perhaps Im on the wrong thought path here and the pressure is more important?
What is the power/ torque output produced by stirling engines most relative to?
Thanks in advance for any replies, and I apologize for my wordiness this morning.
Best regards,
Darian

You would not be the first to power a boat with a Stirling engine. If you do a Google search for "Caloric Ship" you will find one of the earliest attempts to power a large ship with a Stirling engine.

The power of your Stirling comes from the expansion and contraction of your working fluid as it is heated and cooled. Greater temperature differentials will cause greater volume changes, resulting in more power. The choice of working fluid also has a big impact. Hydrogen happens to be one of the best gases for a Stirling engine for a couple of reasons. It is very light. It conducts heat very quickly. And it has volume changes that exceed other gases when exposed to temperature changes. So you would also want to fill your Stirling engine with Hydrogen.

Some advanced designs pressurize their engines to increase the effects of the expanding gas. Not all Stirling designs can be pressurized. An engineer friend of mine built a commercial Stirling that was filled with Hydrogen. He kept the interior pressures less than the atmosphere to prevent any gas from leaking out, as a safety precaution.

Most Stirling engines that are used for power production are using a very high temperature differential. The heat source is often a solar collector/concentrator, or a very hot flame.

There is a group of model engineers in the UK that enjoys Stirling engine boats. They can be found on YouTube.
http://www.youtube.com/results?search_q ... +boat&aq=f

Stirling engine boats are generally very slow and under-powered. The Caloric Ship was eventually re-fitted with a steam engine because it only made about 6 or 7 knots. It did not have enough power for stormy weather. However, that engine was not filled with hydrogen!

Jim Larsen
http://StirlingBuilder.com