Hello community! New member here with a question about viability of a hypothetical thermosiphon application. Is it possible to draw water up from a lake using a heat source? It seems as though a wood-burning boiler system of any sort has to start with water in it, is that right?
Welcome to Permies! You have an interesting question, for which I have no clue of an answer, LOL. But Permies.com is an excellent forum for questions like that and for finding folks who might be able to offer answers.
Thanks! To add some clarification, I would only need it to fill a drum near the shoreline, not use the water for any sort of heating. I’m looking for a very simple setup that is capable of replacing a pump to draw lake water a few feet up into shore, with a secondary purpose of heating that water
The elevation is about 6 feet up and 10 feet over (roughly). The holding tank and pipes would be drained after use. I think a solar pump is out of the question because the usage will be in the winter only. The plan is to cut a hole in the ice and pull water into a tank that can be heated with a wood burner or a fire, similar to a donkey burner. The point is to flood a pond hockey rink with a layer of warm water. If the system works it could also be used for a rustic hot tub in summer months.
Yes but not a simple system.
A pressure vessel superheated and open to atmosphere.
Open the draw valve (to water source) and close the atmospheric vent (top of tank valve), close drain valve
Remove heat and contraction of atmosphere as it cools, will draw water, close draw valve, open vent valve, and open drain valve, drain water to project, and repeat as necessary.
If you fail to open it to atmosphere during the heat cycle it will catastrophically explode.
If you fail to open it to draw and close the vent it will catastrophically implode.
At all times at least one valve must be open or something may break, and you may die.
A blockage of the intake will present the same challenge.
Nothing is foolproof to a sufficiently patient fool!
I hate people who use big words just to make themselves look perspicacious.
Seems to me that this is outside the function of thermosiphon. If I happen to think of anything useful in your application I'll be sure to let you know. Thermosiphon requires a reservoir higher than the heat source and isn't necessarily a function of moving volumes of water with no pump, rather heat to the reservoir.
The only thing you can do with a thermosiphon is to translate the water movement into mechanical movement with a turbine. For this you need a heat collector (exposed to the sun), a heat sink (buried or sunk into something cold) and a pipe connecting both. Put the turbine inside the pipe, and add a small overpressure tank so it absorbs any differences in volume. It that's an electrical turbine, you may use an electric pump. But if you are going for the electric, maybe photovoltaic panels will do better. Maybe a Peltier.
I saw an application in a website where the solar heat expanded a cylinder, it released pressure when it reached the maximum, and used this movement up and down to handle a pump. But I can find it no longer in the internet. So good for preserving knowledge after ten years.