## Heat pipelines in Death Valley

Archimerged has done some calculations regarding how much gravitational energy is available to a turbine installed in the liquid return pipe of a heat pipeline running 2 km up a mountain.  It seems that there is about 54 kW gravitational power for every MW heat power carried up the 2km mountain by a propane heat pipeline.  This is about 10 kW gravitational power for every liter per second propane liquid flowing down the mountain.  The propane vapor flowing upward needs a larger pipeline, perhaps 15 times larger than the liquid pipeline.  The liquid return pipeline must be very well insulated.  The vapor pipeline does not need as much insulation, but calculations are needed for that.

### 3 Responses to “Heat pipelines in Death Valley”

1. 0xff Says:

How about building one out of PVC next to the side of a three story house?

I feel several unconstrained variables here. For this to work/be useful, it must connect to some kind of portable-energy generator: air compressor, alcohol distiller, battery charger. And it must be buildable: the construction materials and the applicatble theory must be in the same realm of possibility.

To make this happen, the search through the design/theory space must tend toward minimum material while maximizing output. Sounds to me like it is time to create a computer program that is configurable (diameters, lengths, angles, fluids, heat sources and sinks, etc) and can simulate changes in the system and calculate required strengths, insulating characteristics of the materials and the power output, and can then search this space by varying its parameters and checking the bounds of the calcualted requirements.

Better to waste time with a computer simulation, than dollars and PVC (and time) trying to build something that is only half understood.

2. 0xff Says:

How can you compete with this:

http://www.playpumps.org/

The sun also give children energy everyday, the school yards are full of their running about, why not capture some of that too?

3. William Says:

This is not a simple heat pipe. The propane vapor must go to the top to be condensed and the liquid must fill the down pipe to achieve maximum pressure on the drive for the turbine. The higher pressures in the liquid pipe as it descends will affect insulation requirements just as atmospheric tempratures will affect those on the vapor side.

A condenser will be needed at the top and turbine or piston engine to extract power to drive generator. Also a boiler or heat exchanger to reheat and boil the propane.