From b1f5c3f8d6671b4331cef1dcebdf63b7a43a3a2b Mon Sep 17 00:00:00 2001 From: priyanka Date: Wed, 24 Jun 2015 15:03:17 +0530 Subject: initial commit / add all books --- 3516/CH15/EX15.3/Ex15_3.sce | 73 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 73 insertions(+) create mode 100644 3516/CH15/EX15.3/Ex15_3.sce (limited to '3516/CH15/EX15.3') diff --git a/3516/CH15/EX15.3/Ex15_3.sce b/3516/CH15/EX15.3/Ex15_3.sce new file mode 100644 index 000000000..0e4711306 --- /dev/null +++ b/3516/CH15/EX15.3/Ex15_3.sce @@ -0,0 +1,73 @@ +printf("\t example 15.3 \n"); +printf("\t approximate values are mentioned in the book \n"); +ts=400; +T1=575; +T2=475; +W=28100; // lb/hr +w=34700; // lb/hr +printf("\t 1.for heat balance \n"); +HT1=290; // enthalpy at T1, Btu/lb, fig 11 +HT2=385; // enthalpy at T2, Btu/lb, fig 11 +Q=(W*(HT2-HT1)); // for preheat +printf("\t total heat required for gasoline is : %.2e Btu/hr \n",Q); +c=0.77; // Btu/(lb), table 7 +Q=((w)*(c)*(T1-T2)); // Btu/hr +printf("\t total heat required for gasoil is : %.2e Btu/hr \n",Q); +delt=118; // F eq 5.14 +S=((T2-ts)/(T1-ts)); +printf("\t S is : %.3f \n",S); +Kc=0.37; // fig 17 +Fc=0.42; +Tc=(T2+(0.42*(T1-T2))); +printf("\t Tc is : %.0f F \n",Tc); +printf("\t hot fluid:inner tube side,gasoil \n"); +Nt=68; +n=6; // number of passes +L=12; //ft +at1=0.546; // flow area,table 10, in^2 +at=((Nt*at1)/(144*n)); // total area,ft^2,from eq.7.48 +printf("\t flow area is : %.3f ft^2 \n",at); +Gt=(w/(at)); // mass velocity,lb/(hr)*(ft^2) +printf("\t mass velocity is : %.2e lb/(hr)*(ft^2) \n",Gt); +mu1=0.65; // at 517F, fig 14,lb/(ft)*(hr) +D=0.0694; // ft +Ret=((D)*(Gt)/mu1); // reynolds number +printf("\t reynolds number is : %.2e \n",Ret); +jH=220; // from fig.24 +Z=0.118; // Z=k*((c)*(mu1)/k)^(1/3), fig 16 +Hi=((jH)*(1/D)*(Z)); //hi/phyt, Hi=()using eq.6.15d,Btu/(hr)*(ft^2)*(F) +printf("\t individual heat transfer coefficient is : %.0f Btu/(hr)*(ft^2)*(F) \n",Hi); +Hio=((Hi)*(0.834/1)); //Hio=(hio/phyp), using eq.6.9 +printf("\t Correct Hi0 to the surface at the OD is : %.0f Btu/(hr)*(ft^2)*(F) \n",Hio); +// (mu1/muw)^(0.14) is negligible +printf("\t cold fluid:shell side,gasoline \n"); +ho=300; // assumption +tw=(ts)+(((Hio)/(Hio+ho))*(Tc-ts)); // from eq.5.31 +printf("\t tw is : %.0f F \n",tw); +deltw=(tw-ts); +printf("\t deltw : %.0f F \n",deltw); +// from fig 15.11, ho>300 +Uc=((Hio)*(ho)/(Hio+ho)); // clean overall coefficient,Btu/(hr)*(ft^2)*(F) +printf("\t clean overall coefficient is : %.0f Btu/(hr)*(ft^2)*(F) \n",Uc); +A2=0.2618; // actual surface supplied for each tube,ft^2,from table 10 +A=(Nt*L*A2); // ft^2 +printf("\t total surface area is : %.0f ft^2 \n",A); +UD=((Q)/((A)*(delt))); +printf("\t actual design overall coefficient is : %.1f Btu/(hr)*(ft^2)*(F) \n",UD); +// check for max. flux=Q/A=12500.(satisfactory) +Rd=((Uc-UD)/((UD)*(Uc))); // (hr)*(ft^2)*(F)/Btu +printf("\t actual Rd is : %.4f (hr)*(ft^2)*(F)/Btu \n",Rd); +printf("\t pressure drop for inner pipe \n"); +f=0.00015; // friction factor for reynolds number 85700, using fig.26 +s=0.71; +phyt=1; +delPt=((f*(Gt^2)*(L)*(n))/(5.22*(10^10)*(D)*(s)*(phyt))); // using eq.7.45,psi +printf("\t delPt is : %.1f psi \n",delPt); +X1=0.09; // X1=((V^2)/(2*g)), for Gt 1060000,using fig.27 +delPr=((4*n*X1)/(s)); // using eq.7.46,psi +printf("\t delPr is : %.1f psi \n",delPr); +delPT=delPt+delPr; // using eq.7.47,psi +printf("\t delPT is : %.1f psi \n",delPT); +printf("\t allowable delPa is 10psi \n"); +printf("\t delPs is negligible \n"); +//end -- cgit