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clear;
clc;
disp('Example 5.17');
// aim : To determine
// the partial pressure of the air and steam, and the mass of the air
// Given values
P1 = 660;// vaccum gauge pressure on condenser [mmHg]
P = 765;// atmospheric pressure, [mmHg]
x = .8;// dryness fraction
T = 273+41.5;// temperature,[K]
ms_dot = 1500;// condense rate of steam,[kg/h]
R = .29;// [kJ/kg]
// solution
Pa = (P-P1)*.1334;// absolute pressure,[kN/m^2]
// from steam table, at 41.5 C partial pressure of steam is
Ps = 8;// [kN/m^2]
// by dalton's law, partial pressure of air is
Pg = Pa-Ps;// [kN/m^2]
mprintf('\n The partial pressure of the air in the condenser is = %f kN/m^2\n',Pg);
mprintf('\n The partial pressure of the steam in the condenser is = %f kN/m^2\n',Ps);
// also
vg = 18.1;// [m^3/kg]
// so
V = x*vg;// [m^3/kg]
// The air associated with 1 kg of the steam will occupiy this same volume
// for air, Pg*V=m*R*T,so
m = Pg*V/(R*T);// [kg/kg steam]
// hence
ma = m*ms_dot;// [kg/h]
mprintf('\n The mass of air which will associated with this steam is = %f kg\n',ma);
// There is misprint in book
// End
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