Am 28.10.2011 23:38, schrieb Akira Shirakawa:
On 2011-10-28 23:15, Peter Heckert wrote:
The problem is, the heat must be dissipated or stored somewhere. Even at
470kW this cannot been done easily.
How was this done? Has nobody seen something. Where there big
ventilators running?
Another 22passi user who was there mentions there were six large
(1.5x1.5 meters) heat exchangers with approximately 1 meter wide
cooling fans.
Thank you very much!
Mass of air: 1.3 kg/m^3
Isobar heat capacity of air: 1kWs/(kg*K) (K = Kelvin)
Calculation for delta T = 50K :
Air mass flow = power/(heat capacity * delta T) = 470 kW/(1 kWs)*kg*K
/(50*K) = 9.4 kg/s.
Air volume flow = 9.4kg/s / (1.3 kg/m^3) = 7.2 m^3 /s
Area of fans = 6*1.5*1.5 m^2 = 13.5 m^2.
Air speed = 7.2/13.5 m/s = 0.53 m/s = 1.9 km/h.
So at delta T = 5 K we would get about 20 km/h of air speed. This is
about the speed of an bicycle.
Yes, this is credible.
I am not used to do such calculations, so please check for errors.
If my calculation is correct, then my question is: Was anybody there and
did feel a warm wind at bicycle speed or a hot wind at slow pedestrian
speed?
