Answer: Third stream’s temperature is and its relative humidity is 50%.
Explanation:
According to the Psychrometric chart.
For the first stream, we have the following.
, R.H = 40%
V = 3L/s
, W = 19 gm of moisture/kg of dry air
= 89 kj/kg
,
For the second stream, we have the following.
R.H = 80%
V = 1 L/s
W = 8.5 gm of moisture/kg of dry air
= 36.5 kj/kg
Now,
=
= 3.286 kg/s
=
= 1.2077 kg/s
We will calculate the value of as follows.
= 3.286 kg/s + 1.2077 kg/s
= 4.5 kg/s
Now, heat balance will be as follows.
= 74.7855 kj/kg
Hence, the moisture balance will be calculated as follows.
= 16.155
Now, again using the psychrometric chart we will find the value of temperature and relative humidity as follows.
Values of and against and are:
R.H = 50%
Thus, we can conclude that third stream’s temperature is and its relative humidity is 50%.