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/CH7/EX7.6/Ex7_6.sce | 107 +++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 107 insertions(+) create mode 100644 3516/CH7/EX7.6/Ex7_6.sce (limited to '3516/CH7/EX7.6') diff --git a/3516/CH7/EX7.6/Ex7_6.sce b/3516/CH7/EX7.6/Ex7_6.sce new file mode 100644 index 000000000..0b79c9742 --- /dev/null +++ b/3516/CH7/EX7.6/Ex7_6.sce @@ -0,0 +1,107 @@ +printf("\t example 7.6 \n"); +printf("\t approximate values are mentioned in the book \n"); +T1=150; // inlet hot fluid,F +T2=90; // outlet hot fluid,F +t1=68; // inlet cold fluid,F +t2=90; // outlet cold fluid,F +W=20160; // lb/hr +w=41600; // lb/hr +printf("\t 1.for heat balance \n"); +printf("\t for solution \n"); +c=(0.3*0.19)+(0.7*1); // Btu/(lb)*(F), bcoz of 30 percent of solution +Q1=((W)*(c)*(T1-T2)); // Btu/hr +printf("\t total heat required for solution is : %.2e Btu/hr \n",Q1); +printf("\t for water \n"); +c=1; // Btu/(lb)*(F) +Q=((w)*(c)*(t2-t1)); // Btu/hr +printf("\t total heat required for water is : %.2e Btu/hr \n",Q); +delt1=T2-t1; //F +delt2=T1-t2; // F +printf("\t delt1 is : %.0f F \n",delt1); +printf("\t delt2 is : %.0f F \n",delt2); +LMTD=((delt2-delt1)/((2.3)*(log10(delt2/delt1)))); +printf("\t LMTD is :%.1f F \n",LMTD); +R=((T1-T2)/(t2-t1)); +printf("\t R is : %.2f \n",R); +S=((t2-t1)/(T1-t1)); +printf("\t S is : %.3f \n",S); +printf("\t FT is 0.81 \n"); // from fig 18 +delt=(0.81*LMTD); // F +printf("\t delt is : %.1f F \n",delt); +Tc=((T2)+(T1))/2; // caloric temperature of hot fluid,F +printf("\t caloric temperature of hot fluid is : %.0f F \n",Tc); +tc=((t1)+(t2))/2; // caloric temperature of cold fluid,F +printf("\t caloric temperature of cold fluid is : %.1f F \n",tc); +printf("\t hot fluid:shell side,phosphate solution \n"); +ID=10.02; // in +C=0.25; // clearance +B=2; // baffle spacing,in +PT=1; +as=((ID*C*B)/(144*PT)); // flow area,ft^2,using eq.7.1 +printf("\t flow area is : %.4f ft^2 \n",as); +Gs=(W/as); // mass velocity,lb/(hr)*(ft^2),using eq.7.2 +printf("\t mass velocity is : %.2e lb/(hr)*(ft^2) \n",Gs); +mu1=1.20*2.42; // at 120F,lb/(ft)*(hr), from fig.14 +De=0.95/12; // from fig.28,ft +Res=((De)*(Gs)/mu1); // reynolds number +printf("\t reynolds number is : %.3e \n",Res); +jH=71; // from fig.28 +c=1; // Btu/(lb)*(F),at 120F,from fig.table 4 +k=0.33; // Btu/(hr)*(ft^2)*(F/ft), from table 4 +Pr=((0.757)*(mu1)/k)^(1/3); // prandelt number raised to power 1/3 +printf("\t Pr is : %.3f \n",Pr); +ho=((jH)*(k/De)*(Pr)); // using eq.6.15,Btu/(hr)*(ft^2)*(F) +printf("\t individual heat transfer coefficient is : %.0f Btu/(hr)*(ft^2)*(F) \n",ho); +printf("\t cold fluid:inner tube side,raw water \n"); +Nt=52; +n=2; // number of passes +L=16; //ft +at1=0.302; // flow area, in^2,from table 10 +at=((Nt*at1)/(144*n)); // total area,ft^2,from eq.7.48 +printf("\t flow area is : %.4f 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); +V=(Gt/(3600*62.5)); +printf("\t V is %.1f fps \n",V); +mu2=0.91*2.42; // at 79F,lb/(ft)*(hr),from table 14 +D=(0.62/12); // from table 10 +Ret=((D)*(Gt)/mu2); // reynolds number +printf("\t reynolds number is : %.2e \n",Ret); +hi=800*1; //using fig.25,Btu/(hr)*(ft^2)*(F) +ID=0.62; // ft +OD=0.75; //ft +hio=((hi)*(ID/OD)); // using eq.6.5 +printf("\t Correct hi0 to the surface at the OD is : %.0f Btu/(hr)*(ft^2)*(F) \n",hio); +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=0.1963; // 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 : %.0f Btu/(hr)*(ft^2)*(F) \n",UD); +Rd=((Uc-UD)/((UD)*(Uc))); // (hr)*(ft^2)*(F)/Btu +printf("\t actual Rd is : %.5f (hr)*(ft^2)*(F)/Btu \n",Rd); +printf("\t pressure drop for annulus \n"); +f=0.0019; // friction factor for reynolds number 15750, using fig.29 +s=1.3; // for reynolds number 25300,using fig.6 +Ds=10.02/12; // ft +phys=1; +N=(12*L/B); // number of crosses,using eq.7.43 +printf("\t number of crosses are : %.0f \n",N); +delPs=((f*(Gs^2)*(Ds)*(N))/(5.22*(10^10)*(De)*(s)*(phys))); // using eq.7.44,psi +printf("\t delPs is : %.1f psi \n",delPs); +printf("\t allowable delPs is 10 psi \n"); +printf("\t pressure drop for inner pipe \n"); +f=0.00023; // friction factor for reynolds number 17900, using fig.26 +s=1; +phyt=1; +D=0.0517; // ft +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=0.08; // 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 delPT is 10 psi \n"); +//end -- cgit