Hi Exeng!!
Just to continue my question, with regards to your answer:
'Air conditioning of the aircraft on the ground is essential, particularly in high ambient temperature conditions, ***hence the fan drawing air over the heat exchangers and the air cycle machine.'***
From my limited knowledge a heat exchager just literally is a interface of two fluids gasses or solids in the same or differing phase with an interconnecting conductor. Hence if you have outside T.A.T. of 100 deg. F. the best with a REALLY efficient heat exchanger, passing hot gasses over this heat exchanger, the minimum temperature you can get the hot gas too is 100 deg. F. due to thermodynamics. ...however my point is this...to get below this imaginary outside temp of 100 deg F. you will need active cooling no matter what simply due to the laws of thermodynamics. My question is how is this achieved..the only types of sustainable self-contained active cooling I know of are
i) Phase change cooling i.e. the use of a refridgerant i.e. R134a, CFC's, HFC's, HCFC's etc. within a pumped system with an evaporator, condensor, strainer and pump; or sometimes used in the world of I.T., solid state silicon 'peltier' coolers...
How is cooling achieved within an aircraft on the ground in hot conditions while not at the gate?? sorry if I am completely off on this point, just using prior knowledge to try and understand.
cheers for any explainations.
Many thanks,
tom.
[This message has been edited by tom775257 (edited 10 January 2001).]