- #1
PCPanos
- 2
- 1
Figure P6.95 provides steady-state test data for a control
volume in which two entering streams of air mix to form a
single exiting stream. Stray heat transfer and kinetic and
potential energy effects are negligible. A hard-to-read
photocopy of the data sheet indicates that the pressure of
the exiting stream is either 1.0 MPa or 1.8 MPa. Assuming
the ideal gas model for air with Cp = 1.02 kJ/kg . K, determine
if either or both of these pressure values can be correct.
Figure shows that:
T1 = 800k
P1 = 1.8Mpa
m(dot)1=1kg/s
T2 = 650K
P2 = 1.0Mpa
m(dot)2 = 2 kg/s
P3 = 1.0Mpa OR 1.8 Mpa (to ues for calculations about wether it is even possible)
i found h1 = 821.95, h2 = 659.84 using thermo tables
So far i have used 0 = m1(h1) + m2(h2) - m3(h3) to find that h3 is 713.88
Im really struggling with the concept of two inlets and finding the change (DELTA)h to use to find the outlet Temp right now.. using (DELTA)h = Cp(DELTA T)...
Where should i go next? I believe i need to find the Delta h but I am really not sure. I've spent hours on this.
Thanks!
PCP
volume in which two entering streams of air mix to form a
single exiting stream. Stray heat transfer and kinetic and
potential energy effects are negligible. A hard-to-read
photocopy of the data sheet indicates that the pressure of
the exiting stream is either 1.0 MPa or 1.8 MPa. Assuming
the ideal gas model for air with Cp = 1.02 kJ/kg . K, determine
if either or both of these pressure values can be correct.
Figure shows that:
T1 = 800k
P1 = 1.8Mpa
m(dot)1=1kg/s
T2 = 650K
P2 = 1.0Mpa
m(dot)2 = 2 kg/s
P3 = 1.0Mpa OR 1.8 Mpa (to ues for calculations about wether it is even possible)
i found h1 = 821.95, h2 = 659.84 using thermo tables
So far i have used 0 = m1(h1) + m2(h2) - m3(h3) to find that h3 is 713.88
Im really struggling with the concept of two inlets and finding the change (DELTA)h to use to find the outlet Temp right now.. using (DELTA)h = Cp(DELTA T)...
Where should i go next? I believe i need to find the Delta h but I am really not sure. I've spent hours on this.
Thanks!
PCP