Diamondoid heat pipe system

From apm
Jump to: navigation, search
This article defines a novel term (that is hopefully sensibly chosen). The term is introduced to make a concept more concrete and understand its interrelationship with other topics related to atomically precise manufacturing. For details go to the page: Neologism.

Today's most efficient way too cool something is by means of heat-pipes.
This likely won't change. But the medium inside the heat pipe can be drastically changed.

Todays heat pipes usually are made out of copper.
They are hollow with a porous high surface area layer inside
and some volatile liquid inside that is evaporating and condensing.

The idea

Warning! you are moving into more speculative areas.

Carry the thermal energy out as fast and far as possible
via heat carrying nanocapsules (capsule transport).

Capsules transported in stratified shear bearing are limited in speed basically just by
curvature radius of the track and thus allow much faster transport than convective transport
For free standing circular tracks there is a fundamental speed limit that lies around 3000m/s.
(See: Unsupported rotating ring speed limit – Not saying that this would be practical or even possible).

Water has a very high heat capacity (due to its molecular structure) but
it also has a rather low heat conductivity (at least when compared copper or to diamond)
Diamond is the reverse. It has exceptionally high heat conductivity but rather low heat capacity. To get the best of both it may make sense to encapsulate very tiny pockets of water inside of diamond nano-capsules. "Optimized thermal mass heat carrier capsules". The water pockets in these (solid block undisassemblable) nanocapsules may be 0D point like, 1D line like, 2D lamellae like, or something more complicated.

As a side-note: This may pose the interesting challenge of cryogenic mechanosynthesis of water ice.
(See notes on cryogenic mechanosynthesis on the page: Thermal management in gem-gum factories)

Factors for the present optimization problem

There are some contradictory requirements working against each other. These include:

Analogous to the porouseness in today's copper heat pipes one would want to interdigitate the diamond heat pipe walls with the the nanocapsule high speed transport channels in a way that maximizes surface area. Concretely: Extruded fir-tree shapes may work out nicely. The problems arising from this tough:

  • More contact area for more thermal contact also means more bearing area causing more friction losses
  • more shear bearing layers to reduce friction also may hamper thermal contact quite significantly.

All in all it's an interesting optimization problem that may lead to designs with interesting structures.

Time will tell if it is possible to outperform current day heatpipes. Maybe it will be possible to outperform them by orders of magnitude.

Maximizing surface area of water that is permanently encapsulated as thermal mass in diamond capsules:

  • reduces the total volume of water
  • may (if very tightly squeezed) reduce the degrees of freeom of the molecules so much that some heat capacity is lost