That's a surprisingly small volume. The machine has one of its smaller dimensions 3 meters. So, even 1.5m/s per second at one end would cool the device.
2016-05-21 15:51 GMT-03:00 Alan Fletcher <[email protected]>: > Back-of-the-envelope calculation > > I'm going to look at a column of air of volume V -- with area A ... and a > height H sufficient to hold > 1-second's worth of 1MW of heat. This has to be vented in 1 second. > > 1MW is 1000 kJ /second. > Q = 1000 kJ in one second > > Specific heat of air at 100C is 1 kJ / (kg K) > Density of air at 100C is r = 1kg/m^3 > > http://www.engineeringtoolbox.com/air-properties-d_156.html > > Ambient air is 20C, heated air is 100C dK = 80 > > Q = S * dK * M > > > Mass = 1kg * r * V = r * V > > Q = S * dK * r * V > > Solve for V : > > V = Q / ( S * dK * r ) = 1000 / ( 1. * 80 * 1.) > = 12.5 m^3 per SECOND > = 750 m^3 per MINUTE > > = 26,486 CFM (Cubic Feet per Minute) > > That's a teeny tiny little fan! > > http://www.industrialfansdirect.com/wall-ventilation.html?&gclid=CIb8x7zb68wCFQEJaQodk4AMnQ > > ------------------------------ > *From: *"Alan Fletcher" <[email protected]> > *To: *"vortex-l" <[email protected]> > *Sent: *Saturday, May 21, 2016 10:37:55 AM > *Subject: *Re: [Vo]:1 MW of heat in a 6,500 sq. ft. facility without > industrial ventilation would be fatal > > This chimney sizing link doesn't really apply --- it's for natural draft > up a chimney of a given height and diameter -- WITHOUT a fan. > > (The longer the chimney the higher velocity of the draft, so a given > diameter can exhaust more heat. They recommend "The velocity of air and > flue gas in a smaller furnace should not exceed *2 m/s*. " -- so I > presume that the charts are based on this, and not the maximum 10m/s.). > > I haven't put a ruler on the aerial photos of the vents on the roof ... > but it looks like they could easily be 22 inches. > > Since a 22-inch vent WITHOUT a fan at a velocity of 2 m/s can handle 1MW, > it seems likely that a vent WITH a fan could also do so. > > There's probably a vent/fan sizing chart somewhere, but this isn't it. > > ------------------------------ > *From: *"Jed Rothwell" <[email protected]> > *To: *"vortex-l" <[email protected]> > *Sent: *Saturday, May 21, 2016 9:16:31 AM > As I said, 1 MW in this space would be like running 16 space heating > furnaces continuously without thermostats. To remove that much heat, you > need a 22" vent and a large fan. An expert from I.H. would have to confirm > this ventilation equipment is installed and working to confirm the claim. 1 > MW of heat release calls for at least at 22" vent: > > http://www.engineeringtoolbox.com/chimney-sizing-d_175.html > > -- Daniel Rocha - RJ [email protected]
