Answer:
The dew point temperature is 11.65°C
Explanation:
Dew point temperature formula is given as follows;
From the modified Apjohn equation, we have;
[tex]P_v = P'_v -\dfrac{1.8 \times p (t - t')}{2700}[/tex]
Which gives;
The saturation vapor pressure at 15°C = 1.705 kPa
[tex]P'_v[/tex] = 1.705 kPa
p = 101.325 kPa
[tex]P_v[/tex] = 1.705 - 1.8*101.325*(20 - 15)/2700 = 1.36725 kPa
The dew point temperature is the steam saturation temperature at 1.36725 kPa
= 6.9696 + (17.4953 - 6.9696)*(0.0136725 - 0.01)/(0.02 - 0.01) = 10.84°C by approximation calculation from steam tables and 284.8 K = 11.65°C from Wolfram Alpha.
