4 files changed, 205 insertions, 0 deletions
diff --git a/2705/CH19/EX19.1/Ex19_1.sce b/2705/CH19/EX19.1/Ex19_1.sce
new file mode 100755
index 000000000..feed53150
--- /dev/null
+++ b/2705/CH19/EX19.1/Ex19_1.sce
@@ -0,0 +1,46 @@
+clear;
+clc;
+disp('Example 19.1');
+
+// aim : To compare the moisture content and the true specific volumes of  atmosphere air 
+// (a) temperature is 12 C and the air is saturaded
+// (b) temperature is 31 C and air is .75 saturated
+
+// Given values
+P_atm = 101.4;// atmospheric pressure, [kN/m^2]
+R = .287;// [kJ/kg K]
+
+// solution
+// (a)
+T = 273+12;// air temperature, [K]
+// From steam table at 12 C
+p = 1.4;// [kN/m^2]
+vg = 93.9;// [m^3/kg]
+pa = P_atm-p;// partial pressure of the dry air, [kN/m^2]
+va = R*T/pa;// [m^3/kg]
+
+mw = va/vg;// mass of water vapor in the air,[kg]
+v = va/(1+mw);// specific volume of humid air, [m^3/kg]
+
+mprintf('\n (a) The mass of water vapor in the humid air is  =  %f  kg\n',mw);
+mprintf('\n      The specific volume of humid air is  =  %f m^3/kg\n',v);
+
+// (b)
+x = .75;// dryness fraction
+T = 273+31;// air temperature, [K]
+// From steam table
+p = 4.5;// [kN/m^2]
+vg = 31.1;// [m^3/kg]
+pa = P_atm-p;// [kN/m^2]
+va = R*T/pa;// [m^3/kg]
+mw1= va/vg;// mass of water vapor in the air, [kg]
+mw_actual = mw1*x;// actual mass of vapor, [kg]
+v = va/(1+mw_actual);// true specific volume of humid air,[m^3/kg] 
+
+mprintf('\n (b) The mass of water vapor in the humid air is  =  %f  kg\n',mw1);
+mprintf('\n     The specific volume of humid air is  =  %f  m^3/kg\n',v);
+
+ewv = mw_actual/mw ;
+mprintf('\n On the warm day the air conteains %f  times the mass of water vapor as on the cool day \n',ewv);
+
+//  End
diff --git a/2705/CH19/EX19.2/Ex19_2.sce b/2705/CH19/EX19.2/Ex19_2.sce
new file mode 100755
index 000000000..99dc20724
--- /dev/null
+++ b/2705/CH19/EX19.2/Ex19_2.sce
@@ -0,0 +1,34 @@
+clear;
+clc;
+disp('Example 19.2');
+
+// aim : To determine
+// (a) the partial pressures of the vapor and the dry air
+// (b) the specific humidity of the mixture
+// (c) the composition of the mixture
+
+//  Given values
+phi = .65;// Relative humidity
+T = 2733+20;// temperature, [K]
+p = 100;// barometric pressure, [kN/m^2]
+
+// solution
+// (a)
+//  From the steam table at 20 C
+pg = 2.34;// [kN/m^2]
+ps = phi*pg;// partial pressure of vapor, [kN/m^2]
+pa = p-ps;// partial pressure of dry air, [kN/m^2]
+mprintf('\n (a) The partial pressure of vapor is  =  %f  kN/m^2\n',ps);
+mprintf('\n     The partial pressure of dry air is  =  %f kN/m^2\n',pa);
+
+// (b)
+// from equation [15]
+omega = .622*ps/(p-ps);// specific humidity of the mixture
+mprintf('\n (b) The specific humidity of the mixture is  =  %f kg/kg dry air\n',omega);
+
+// (c)
+// using eqn [1] from section 19.2
+y = 1/(1+omega);// composition of the mixture
+mprintf('\n (c) The composition of the mixture is  =  %f\n',y);
+
+// End
diff --git a/2705/CH19/EX19.3/Ex19_3.sce b/2705/CH19/EX19.3/Ex19_3.sce
new file mode 100755
index 000000000..54f4d0111
--- /dev/null
+++ b/2705/CH19/EX19.3/Ex19_3.sce
@@ -0,0 +1,52 @@
+clear;
+clc;
+disp('Example 19.3');
+
+// aim : To determine
+// (a) the specific humidity
+// (b) the dew point
+// (c) the degree of superheat of the superheated vapor
+// (d) the mass of condensate formed per kg of dry air if the moist air is cooled to 12 C
+
+// Given values
+t = 25;// C
+T = 273+25;// moist air temperature, [K]
+phi = .6;// relative humidity
+p = 101.3;// barometric pressure, [kN/m^2]
+R = .287;// [kJ/kg K]
+
+// solution
+// (a)
+// From steam table at 25 C
+pg = 3.17;// [kN/m^2]
+ps = phi*pg;// partial pressure of the vapor, [kN/m^2]
+omega = .622*ps/(p-ps);// the specific humidity of air
+
+mprintf('\n (a) The specific humidity is  =  %f  kg/kg air\n',omega);
+
+// (b)
+// Dew point is saturated temperature at ps is,
+t_dew = 16+2*(1.092-1.817)/(2.062-1.817);// [C]
+mprintf('\n (b) The dew point is  =  %f C\n',t_dew);
+
+// (c)
+Dos = t-t_dew;// degree of superheat, [C]
+mprintf('\n (c) The degree of superheat is  =  %f C\n',Dos);
+
+// (d)
+// at 25 C
+pa = p-ps;// [kN/m^2]
+va = R*T/pa;// [m^3/kg]
+// at 16.69 C
+vg = 73.4-(73.4-65.1)*.69/2;// [m^3/kg]
+ms1= va/vg; 
+// at 12 C
+vg = 93.8;// [m^3/kg]
+ms2 = va/vg;
+
+m = ms1-ms2;// mas of condensate
+mprintf('\n (d) The mass of condensate is  =  %f  kg/kg dry air\n',m);
+
+//  there is calculation mistake in the book so answer is no matching
+
+//  End
diff --git a/2705/CH19/EX19.4/Ex19_4.sce b/2705/CH19/EX19.4/Ex19_4.sce
new file mode 100755
index 000000000..0cec4f91c
--- /dev/null
+++ b/2705/CH19/EX19.4/Ex19_4.sce
@@ -0,0 +1,73 @@
+clear;
+clc;
+disp(' Example 19.4');
+
+// aim : To determine
+// (a) the volume of external saturated air
+// (b) the mass of air
+// (c) the heat transfer
+// (d) the heat transfer required by the combind water vapour
+
+// given values
+Vb = 56000;// volume of building, [m^3]
+T2 = 273+20;// temperature of air in thebuilding, [K]
+phi = .6;// relative humidity
+T1 = 8+273;// external air saturated temperature, [K]
+p0 = 101.3;// atmospheric pressure, [kN/m^2]
+cp = 2.093;// heat capacity of saturated steam, [kJ/kg K]
+R = .287;// gas constant, [kJ/kg K]
+
+// solution
+// from steam table at 20 C saturation pressure of steam is,
+pg = 2.34;// [kN/m^2]
+
+// (a)
+pvap = phi*pg;// partial pressure of vapor, [kN/m^2] 
+P = p0-pvap;// partial pressure of air, [kN/m^2]
+V = 2*Vb;// air required, [m^3]
+// at 8 C saturation pressure ia
+pvap = 1.072;// [kN/m^2]
+P2 = p0-pvap;// partial pressure of entry at 8 C, [kN/m^2]
+
+// using P1*V1/T1=P2*V2/T2;
+V2 = P*V*T1/(T2*P2);// air required at 8 C, [m^3/h]
+mprintf('\n (a) The volume of air required is  =  %f  m^3/h\n',V2);
+
+// (b)
+//  assuming
+pg = 1.401;// pressure, [kN/m^2]
+Tg = 273+12;// [K]
+vg = 93.8;// [m^3/kg]
+// at constant pressure
+v = vg*T2/Tg;// volume[m^3/kg]
+mv = V/v;// mass of vapor in building at 20 C, [kg/h]
+// from steam table at 8 C
+vg2 = 121;// [m^3/kg]
+mve = V2/vg2;// mass of vapor supplied with saturated entry air, [kg/h]
+mw = mv-mve;// mass of water added, [kg/h]
+mprintf('\n (b) The mass of water added is  =  %f  kg/h\n ',mw);
+
+// (c)
+// for perfect gas
+m = P2*V2/(R*T1);// [kg/h]
+Cp = .287;// heat capacity, [kJ/kg K]
+Q = m*Cp*(T2-T1);// heat transfer by dry air,[kJ/h]
+mprintf('\n (c) The heat transfer required by dry air is  =  %f MJ/h\n',Q*10^-3);
+
+// (d)
+// from steam table
+h1 = 2516.2;// specific enthalpy of saturated vapor at 8 C,[kJ/kg]
+hs = 2523.6;// specific enthalpy of saturated vapor at 20 C, [kJ/kg]
+h2 = hs+cp*(T2-T1);// specific enthalpy of vapor at 20 c, [kJ/kg]
+Q1 = mve*(h2-h1);// heat transfer required for vapor, [kJ]
+
+// again from steam table
+hf1 = 33.6;// [kJ/kg]
+hg3 = 2538.2;// [kJ/kg]
+Q2 = mw*(hg3-hf1);// heat transfer required for water, [kJ/h]
+Qt = Q1+Q2;// total heat transfer, [kJ/h]
+mprintf('\n (d) The heat transferred required for vapor+supply water is  =  %f  MJ/h\n',Qt*10^-3);
+
+//  there is minor variation in the answer reported in the book
+
+//  End