Open Evaporative Cooling

1
Open Evaporative Cooling

• An idea for a compact cooling layout for
  electronic systems that uses liquid C02
  evaporating through porous ceramic blocks
• Richard Apsimon, PPD
• Andy Nichols, EID
• Mike Woodward, EID
• Marc Weber, PPD
• Mike Tyndel, PPD
• Justin Greenhalgh, EID

2
Open Evaporative cooling

• Some of us at RAL have expressed an interest in
  working on open evaporative cooling. We know of
  two approaches
• Idea of Marco Olcese direct application of
  evaporative fluid to components suggested at
  Genova workshop
• Idea of Richard Apsimon a porous ceramic
  interface between fluid and modules
• Both ideas are very immature at present
• Much too early for any detailed engineering this
  is just a mini statement of interest

3
Open Evaporative Cooling

• Currently, the evaporation takes place inside a
  closed tube, with many exhausts, according to
  circuit modularity. This is bad for
• Material mass
• Number of connectors and exhaust tubes
• General complication
• Compactness

Heat source
Inlet (liquid) flow
Vapour
Typically there could be Around fifty circuits
Cooling circuit
Transverse view of Cooling circuit
Compressor/ Condenser
Heat source
Exhaust (vapour) flow
4
Open Evaporative Cooling
Maybe a better approach is to evaporate through
porous ceramic blocks, a bit like This
Single exhaust tube
Compressor/condenser
Heat source
Outer enclosure
Porous ceramic blocks, linked by metal tubes
Very significant saving in Material mass,
connectors and General complication
Porous ceramic block
Evaporation
5
Open Evaporative Cooling

• Some tentative objectives
• Understand the theory properly (AN is not
  qualified to do this!) CO2 phase diagram and
  flow characteristics of the porous ceramics and
  metal pipework (by December 2006)
• (RAL cooling/cryogenic group has already started
  this)
• Continue discussions with ceramics industry
  Identify correct type of ceramic (by June 2007)
• Develop a reliable ceramic/tube interconnect
  (June 2007)
• Build a suitable CO2 gas rig
• No serious attempt has been made to estimate
  costs or effort requirements yet.