simple air flow problem
simple air flow problem
(OP)
Administration kills engineering. Design calculation ability is a muscle, if not trained it atrophies...
I am curently designing a mobile generator unit in a closed area.I need to determine the amount of air flow requiered to maintain an ambiant temp of no more than 40ºc.
Known:
desired ambiant temp: 40ºc
outside temp (cooling air) :up to 30ºC
kw regected by components inside habitacle :205Kw
unknown:
air flow volume needed in order to maintain ambiant temp at no more than 40ºc in order to select exhaust fan and inlet damper/loovers?
air speed could reach up to 1000ft/min
I need reminding of practical equations/formulas and basic notions?
I am curently designing a mobile generator unit in a closed area.I need to determine the amount of air flow requiered to maintain an ambiant temp of no more than 40ºc.
Known:
desired ambiant temp: 40ºc
outside temp (cooling air) :up to 30ºC
kw regected by components inside habitacle :205Kw
unknown:
air flow volume needed in order to maintain ambiant temp at no more than 40ºc in order to select exhaust fan and inlet damper/loovers?
air speed could reach up to 1000ft/min
I need reminding of practical equations/formulas and basic notions?





RE: simple air flow problem
Airflow (cu. ft. per minute)=Total Heat (Btu per hr)/(1.08*Temp. diff. in deg. F)
RE: simple air flow problem
RE: simple air flow problem
Required flow can be calculated according to
Q = H/c*p*(Ti - To)
assume that
H = 205kWt or 11658 Btu/min,
c = 0.24,
p = 0.075,
Ti = 30C or 86F,
To = 40C or 104F,
and Q = only 35981 CFM.
RE: simple air flow problem
air density (0.075 lbm/ft3)
x
specific heat of air (0.24 Btu/lbm F)
x
60 min/hr
so that the answer comes up ft3/min
RE: simple air flow problem
Good Luck!