It is time to understand the Propane tank thing. When the propane evaporates, as with any other liquid, it requires heat. Myles understands this because he is into steam boats. re-stated, to convert a liquid to vapor, heat is required. The liquid absorbs surrounding heat to do the work of converting to a vapor. Putting a propane tank in water simply makes a better thermal connection to the walls of the tank that fins would do just as well. This is taught in refrigeration school, boiler theory or any other science requiring distillation of liquids, and many more examples.
The concept has been observed and put to practice in things as simple as evaporative coolers, to cryogenics. It is commendable that observation has started a quest. I must have 500 pdf files, and just as many html pages on this subject for my research in my effort to become self sufficient.
Like I stated earlier, I would look into stirling cycle, solar heat collectors and sinking heat using the water around the boat. I would spend a lot of time studying hull shapes that required little power to move thru the water at the highest speed i.e. Long narrow multi-hulls. I would give up sails for foils (kites). My canopy would be solar heat collectors of the vacuum tube type, and likely use an electric drive hooked up to a surface piercing prop.
The object of my design would be a puddle jumper with longer distances than obtainable using conventional wisdom and design. A sleeping cudy, and very wet cockpit, would be necessary to accomplish the design goal (fast and light). The major weight would be in the solar collectors, The batteries would be lithium Iron in a minimum configuration. At least 4 kites would be needed for very light winds through 50kt wind conditions, as this would be the primary drive. The kites would be expected to help lift the hulls to plane state.
Do I hear any sponsors ;)
Kevin Pemberton
On 08/10/2010 10:23 AM, Capt. Mike wrote:
"A story: hobby steamboaters who use propane as fuel for their boilers often place their propane tanks in a water bath to keep from freezing and choking off the energy flow. Sometimes they also run a steam line to the water tank. "
Miles;
As I mentioned to Ron. Seems like the perfect solution for a cruising sailboat would be to have a propane tank in the boats ice box. When it freezes it will cool down the ice box. But you are absolutely right any leaks of propane need to be vented outside the boat. But, I don't see that as a hard thing to do.
Capt. Mike
Sent from on board BIANKA
http://biankablog.blogspot. com
From: "Myles Twete" <matwete@comcast.net> Sender: electricboats@yahoogroups. com Date: Tue, 10 Aug 2010 08:41:39 -0700To: <electricboats@yahoogroups. com> ReplyTo: electricboats@yahoogroups. com Subject: RE: [Electric Boats] Water Temperature
If one is running a genset on propane AND generating electricity from solar panels at the same time, one could put the propane tank in a bath of water, with the chilled water pumped up to cool the solar panels (which would raise the water temperature) and return the water to the propane tank bath. This would help the propane tank and lines keep from freezing while delivering power and at the same time help keep the solar panels cool to maximize their efficiency.
But how often would one be both generating power from burning propane and generating power from solar.
A story: hobby steamboaters who use propane as fuel for their boilers often place their propane tanks in a water bath to keep from freezing and choking off the energy flow. Sometimes they also run a steam line to the water tank. And often that's as far as they go---a manually operated steam line going to this tank to help warm that water. Unfortunately, in at least a couple cases, that manual control was forgotten about and the water temperature not monitored until the propane tank "vented" due to overpressure. And in each of those cases, the vent was not piped overboard and so the propane vented into the bilge and into the boiler fire leading to fire/explosion and man overboard. A solar/propane bath recirculating system wouldn't likely run that same risk, but regardless, do please direct any propane vents overboard if using propane.
-mt
From: electricboats@
yahoogroups. com [mailto:electricboa ts@yahoogroups. com] On Behalf Of Ron
Sent: Sunday, August 08, 2010 11:12 AM
To: electricboats@yahoogroups. com
Subject: Re: [Electric Boats] Water Temperature
Bob,
I guess the silence is loud and clear, Ned gave an answer that while correct, only confirms that efficency is extremly low and this is based on the use of water at a certain temperature as both the source and sink. The phrase "slow boat to china" comes to mind :)
My idea of a waterfall thrugh the keel didn't seem to go very well, but then most questions and answers have been revolving around small amounts of generation or recovery.
My thoughts about recovery of waste heat, or preventing overheating, involve the use of liquid propane as a sink (-44 degrees @ 0 psi) and if using a water surface temperature of 70 degrees, pressure will build to 110 psi.
Having a temperature delta of -50 > +1200 F is easy to set up and such a wide range will only assist in speed of cycle and not so much about how much energy is taken in.
The simple fact is, heat builds pressure and pressure produces work potential and mass flow equates to power.
With those comments I'll withdraw the subject and carry on with my work as best I can.
Cheers
Ron
-- Ubuntu10.04, Acer AspireOne, Virgin Mobile 3G Broadband2go. Doesn't get any better than this!
No comments:
Post a Comment