Nitrogen enters a steady-flow heat exchanger at 150 kPa, 10°C, and 100 m/s, and it receives heat in the amount of 120 kJ/kg as it flows through it. Nitrogen leaves the heat exchanger at 100 kPa with a velocity of 200 m/s. Determine thejvlach number of the nitrogen at the inlet and the exit of the heat exchanger.
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Nitrogen enters a steady flow heat exchanger with velocity 100 m/s and leaves with velocity 200 m/s. The temperature in the inlet is 100C and we need to find out the temperature in the outlet .
Internal energy qin =120 KJ/kg
The gas constant of nitrogen R =0.2968 KJ/kg K
The specific heat of nitrogen, cp =1.040 KJ/kg K
The speed of the nitrogen at the inlet
C1 =342.9 m/s
The mach number at the inlet
To find out the speed at the outlet the T value is unknown so it can find out by using the steady flow balance equation.
qin =cp(T2 -T1)+
120 KJ/kg =(1.040)(T2 -100)+
T2 =384 K