- #1
Gaby
- 7
- 2
- Homework Statement
- A fire is created in a room. The height of the door is 1.83 m and its
width is 0.74 m. The neutral plane is established at the height
1.0 m. The fire is sustained by propane (C3H8) with a mass flow
rate of 1.25 X10-3 kg/s and the oxidiser is air (79% vol. nitrogen
N2, 21% vol. oxygen O2). The air flows through the door opening
with an average velocity of Vin=0.7 m/s and a temperature of
Tin=298K.
(iv) Determine the average temperature and velocity of
outflowing gases.
Apply the principle of energy conservation for a steady-state open
system. Neglect the difference in kinetic and potential energy of
inflowing and outflowing gases as compared to the rate of energy
transfer to the gases (i.e. due to the heat release rate by the fire).
Assume that
− the combustion is perfect,
− the entire heat of reaction is spent on heating of gases in the
room;
− the average specific heat of outflowing gases is
cp=1050 J/kg/K and the average molecular mass of the
outflowing gases is equal to that of the ambient air
Min=Mout=29 kg/kmol.
- Relevant Equations
- The first law of thermodynamics for open systems
(Please see enclosed pdf doc, sorry equation wont copy correctly into text box.)
Please see enclosed my calculations for parts 1-3.
I am stuck on the final part of of a 4 part question, any help or guidance would be very much appreciated, thanks.
I am stuck on the final part of of a 4 part question, any help or guidance would be very much appreciated, thanks.