Answer:
32.06m³/s
0.62kg/s
Explanation:
Using our psychometric chart, at T1 = 22°C and wet bulb = 16°C, we have
h1 = 45.6kj/kg
v1 = 0.85m³/kg
w1 = 0.00923
At T2 = 30°C, T3 = 40°C, T4 = 33°C
h2 = 96.1kj/kg
w2 = 0.02579
h3 = 168kj/kg
h4 = 138kj/kg
Using the mass for rate balances for water and air, we have
m'(a1) = m'(a2) = m'(a)
m'(3) - m'(4) = m'(a) [w2 - w1] = m'(m)
Now, we use the energy balance equation to solve for the needed mass, m'(a). Mass flow rate of water, m'3 = 60kg/s
0 = m'(a)h2 + m'4h4 - m'(a)h1 - m'3h3
0 = m'(a) [h2 - h1] + [-m'(a) {w2-w1} + m'3]h4 - m'3h3
m'(a) = [m'3(h3 - h4) ] / [ h2 - h1 - (w2 - w1)h4
m'(a) = [60(168-138)] / 96.1 - 45.6 - (0.02579 - 0.00923)168
m'(a) = 60*30 / 50.5 - 0.01656*168
m'(a) = 1800 / 47.72
m'(a) = 37.72kg/s
Volume flow rate = m'(a) * v1
Volume flow rate = 37.72 * 0.85
Volume flow rate = 32.06m³/s
Mass flow rate of make up water =
m'(m) = m'(a) [w2 - w1]
m'(m) = 37.72 [0.02579 - 0.00923]
m'(m) = 37.72 * 0.01656
m'(m) = 0.62kg/s
