Question on thermodynamics

Cooling systems on transmission cable circuits are not a new thing, however they have generally been used to allow greater currents when the cables have been operating at their maximum temperature rather than trying to keep the temperature to 20°C. Water is probably the most commonly used coolant and, for buried cable systems, is pumped along pipes adjacent to or enveloping the cables ; but many such systems are no longer used due to reliability issues. In tunnels cables have sometimes been installed in water filled troughs but this appraoch has generally been abandoned; more commonly is to rapidly push, or pull, air through the tunnel to remove the heat, sometimes with chiller units on the inlet or with additional cooling from water pipes along the tunnel.


It should also be noted that for most of the time a transmission cable circuit does not operate at its full capacity and so is not at its maximum temperature as networks are usually designed to share the load over a number of circuits. Consequently any cooling system is unlikely to be operating most of the time and is hence more likely to not operate when required (just as central heating systems are more likely to breakdown when you turn them back on after a hot summer).


Whilst cooling of transmission cables may seem a way of reducing the use of non-renewable resources etc., increasing the amount of conductor (by size, to some degree, or by increased numbers) carrying the current or reducing the end user demand are possibly better solutions. You also should remember that any repair work also uses non-renewable resources etc.


If you want to know more about cable cooling then if you do a search you will find that there are a good number of papers on the subject. As I say, if talking about cooling transmission cables, sorry but it is not a new concept.