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Process Circuit Analysis 1 05

Table 3.2.2 Revised Summary of Equations for Calculating Cooling-
Tower Air Flow Rate _____________________________

Subscripts: H 2O = 1 , Air = 2

Mole Balances

y u m, + m 3' = y 2jl m 2 + nu (3.2.22)
yi,2 rn, = y 2-2 m 2 (3.2.23)

yu+yi,2=l (3.2.24)
Yy + 72,2 = 1 (3.2.25)
Energy Balance

h, m, + h 3 m 3' = h 2 m 2 + h4 nx, (3.2.26)

Transport Relation
( h'^ 1
f(t lw', y 1W; Ah vw) = yiw - yi.i =1 —— I —— (ti' - t lw') (1 - y, w) (3.2.27)
I k' ) Ah vw

Equilibrium Relations

y v =0.9p 2?ls /P' (3.2.28)

yiw = Piw/P' (3.2.29)
Thermodynamic Properties
Piw = flW) — steam tables (3.2.30)

Ahvw = flt| W') — steam tables (3.1.31)

s
P2,is Ah vw ( 1 1 !
p, w R' T 2 T 1W )
T 2 = t 2 + 460.0 (3.2.33)

Tiw = W +460.0 (3.2.34)

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