Question

In a heating system, cold outdoor air at 7°C flowing at a rate of 4 kg/min is mixed adiabatically with heated air at 66°C flowing at a rate of 5 kg/min. Determine the exit temperature of the mixture. Solve using appropriate software.

Answer 1

Answer:

The exit temperature of the mixture is 39.7°.

Explanation:

Given that,

Outdoor temperature = 7°C

Flowing rate = 4 kg/min

Temperature = 66°C

Flowing rate = 5 kg/min

We need to calculate the exit temperature of the mixture

Using  balance equation for the system

$m_{1}T_{1}+m_{2}T_{2}=(m_{1}+m_{2})T_{3}$

$T_{3}=\dfrac{m_{1}T_{1}+m_{2}T_{2}}{(m_{1}+m_{2})}$

Put the value into the formula

$T_{3}=\dfrac{4\times 7+5\times 66}{4+5}$

$T_{3}=39.7^{\circ}$

Hence, The exit temperature of the mixture is 39.7°.