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Closed Cycle Putput Engine

Putput engine creates power efficiently and cheap
  [vote for,

[edited. summary read: "creates energy" meant power of course]

A putput engine is a pipe filled with water, with its ends inserted in water.

The upper end is heated causing the water in the pipe in that area to boil and turn to steam, pushing the water out of the pipe, but by the time the steam reaches the end of the pipe it condenses from the cooling by the water outside the lower part of the pipe. New cold water rushes in further cooling down what's left of the steam which now completely turns back to warm water.

If (a) instead of two pipes the same width, the pipes leaving the boiling area where different in diameter, one being thick and one thin,

And (b) rather than an open end it would culminate in a loop,

Then the water would be moving in a constant circle rather than resonating back and forth.

pashute, Oct 15 2012


       Creates energy?
cudgel, Oct 15 2012

       How does this do useful work?
8th of 7, Oct 15 2012

       A closed loop under steady heat equals balanced pressure at both ends, regardless of diameter. Therefore, no movement, therefore no work ouput.   

       Unless I am misreading this [Marked-For-Deletion] Bad Science.   

       Edit: I am not misreading this, a putt putt engine cannot work in a closed cycle. The venting steam does not condense, it is replaced by new cold water being pulled in due to momentum causing an over exhaustion of the combustion chamber.
MechE, Oct 15 2012

       It could make the noisy refrigerator from hell - where, on a frosty day, it may work.
lurch, Oct 15 2012

       The venting steam definitely DOES condense. See wikipedia pop pop boat. Water only is going both ways out and back into the pipe. According to them, the movement is surprisingly caused by the inward momentum of the water being transferred to the boat, while the outward momentum is being dispersed.   

       This seems to be an erroneous explanation since adding a "jet" by making both tips thinner adds to the speed of the boat.   

       Anyways, the circular system would look something like the lowercase letter d. Water is filled only halfway of the bottom "ring" of the d, and the rest is air.   

       On the bottom corner of the "ring" there is a simple valve that lets water flow one way but not the other. The right side of d is heated. Steam pushes up into the top and downward. water is pushed up and through the valve compressing the air and steam.   

       circular water flow ensues.
pashute, Nov 11 2012

       No it does not. The pressure against the face of the valve prevents water movement into the heated area.   

       You are trying to extract power from a closed loop, with no temperature/pressure variation. This is not possible. Even if you have a condenser to remove heat, the pressure is constant throughout the loop.
MechE, Nov 11 2012

       Your right. Correcting the configuration:   

       putt putt pipes go down into ring which is much wider than the pipe and is set horizontally on the ground (with a vertical axis). Water fills most of the ring with some air above allowing for a pressure wave.   

       once inside the ring the pipes bend 45 degrees into the plane of the ring.   

       Movement of water back and forth causes water to flow in a circle.   

       Stage II - stand the ring up partially, so that one side of the ring is completely filled with water, while the other is only mostly filled with water and only a small "air pocket" is available. - Should still work.   

       Finally: stand it on its side, so that now it has a "horizontal axis" and add the "d" stick (snorkel) on the right as the air pocket. Have the pipe inserted into the wheel on the left like an inverted letter Q. Heating the water in the pipe should cause the water in the ring to turn.   

       Of course a lot of the incoming energy is going into heating the water, but hopefully, a nice proportion of it is going into kinetic energy.
pashute, Nov 11 2012

       // a lot //   

       Sp. "all"   

       // a nice proportion //   

       Sp. "almost none of"
8th of 7, Nov 11 2012

       show me a motor that runs a boat from a candle and does a better job...
pashute, Nov 11 2012

       The problem isn't the put-put engine, the problem is the closed loop. Thermodynamic engines need differentials to work. In a closed loop with no moving parts and a constant heat source, you can't generate a pressure differential, which means no power out.
MechE, Nov 11 2012

       //Then the water would be moving in a constant circle rather than resonating back and forth.// You may have misunderstood how these motors work. The first thing to realise is that they work perfectly well (and are easier to understand) with only one pipe coming out the back. The double pipe is for ease of filling or construction.   

       However, I'm pretty sure you can make a closed oscillating (not circulating) engine of this type. Take a working (single pipe for simplicity) put put engine. Normally, the end of the pipe is submerged in an open body of water. I can't see any reason why the end of the pipe could not be joined instead to a (cooled) closed vessel partly filled with water.   

       Free water surface:


       Put put engine:

       Closed vessel:

       Closed put put engine:

       The cooled vessel essentially models the free water body + atmosphere. It may have to be relatively large.
spidermother, Nov 11 2012

       Possibly, if it is extremely large. The problem is that the closed chamber acts as a shock absorber, minimizing the overshoot from the putt-putt action, reducing the water kick-back. The engine also needs to be able to move independently inside the chamber (as in traveling around a central axis or similar). Of course the external cooling is also required, as you mentioned.   

       At that point, while it could be considered a "closed cycle with a putt-putt engine", I would be extremely hesitant to call it a "closed cycle putt-putt engine". Maybe I'm splitting hairs here, but you can define any system as closed cycle if you include the entire universe.
MechE, Nov 11 2012


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