//Chapter-4, Illustration 7, Page 170 //Title: Steam Nozzles and Steam Turbines //============================================================================= clc clear //INPUT DATA P1=10;//Pressure at point 1 in bar P2=0.5;//Pressure at point 2 in bar h1=3050;//Enthalpy at point 1 in kJ/kg h2s=2480;//Enthalpy at point 2s in kJ/kg ht=2910;//Enthalpy at throat in kJ/kg n=1.3;//Adiabatic gas constant r=0.1;//Total available heat drop v1=0.258;//Specific volume at point 1 in (m^3)/kg h2f=340.6;//Enthalpy for exit pressure from steam tables in kJ/kg hfg=2305.4;//Enthalpy for exit pressure from steam tables in kJ/kg m=0.5;//Mass flow rate in kg/s //CALCULATIONS x=n/(n-1);//Ratio Pt=((2/(n+1))^x)*P1;//Temperature at throat in bar h2=h2s+(r*(h1-h2s));//Enthalpy at point 2 in kJ/kg vt=((P1/Pt)^(1/n))*v1;//Specific volume at throat in (m^3)/kg v2=((P1/P2)^(1/n))*v1;//Specific volume at point 2 in (m^3)/kg Ct=sqrt(2000*(h1-ht));//Throat velocity in m/s At=((m*vt)/Ct)*(10^6);//Throat area in (mm^2) C2=sqrt(2000*(h1-h2));//Exit velocity in m/s A2=((m*v2)/C2)*(10^6);//Exit area in (mm^2) x2=((h2-h2f)/hfg)*100;//Steam quality at exit //OUTPUT mprintf('Throat area is %3.0f (mm^2) \n Exit area is %3.0f (mm^2) \n Steam quality at exit is %3.0f percent',At,A2,x2) //==============================END OF PROGRAM=================================