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Diffstat (limited to '1328/CH8/EX8.2')
-rw-r--r-- | 1328/CH8/EX8.2/8_2.sce | 111 |
1 files changed, 111 insertions, 0 deletions
diff --git a/1328/CH8/EX8.2/8_2.sce b/1328/CH8/EX8.2/8_2.sce new file mode 100644 index 000000000..542173a86 --- /dev/null +++ b/1328/CH8/EX8.2/8_2.sce @@ -0,0 +1,111 @@ +printf("\t example 8.2 \n");
+printf("\t approximate values are mentioned in the book \n");
+T1=250; // inlet hot fluid,F
+T2=100; // outlet hot fluid,F
+t1=90; // inlet cold fluid,F
+t2=150; // outlet cold fluid,F
+W=60000; // lb/hr
+w=168000; // lb/hr
+printf("\t 1.for heat balance \n");
+printf("\t for acetone \n");
+c=0.57; // Btu/(lb)*(F)
+Q=((W)*(c)*(T1-T2)); // Btu/hr
+printf("\t total heat required for acetone is : %.2e Btu/hr \n",Q); // calculation mistake in problem
+printf("\t for acetic acid \n");
+c=0.51; // Btu/(lb)*(F)
+Q1=((w)*(c)*(t2-t1)); // Btu/hr
+printf("\t total heat required for acetic acid is : %.2e Btu/hr \n",Q1); // calculation mistake in problem
+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 : %.1f \n",R);
+S=((t2-t1)/(T1-t1));
+printf("\t S is : %.3f \n",S);
+printf("\t FT is 0.88 \n"); // from fig 20,for 3-6 exchanger
+delt=(0.88*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 : %.0f F \n",tc);
+printf("\t hot fluid:shell side,acetone \n");
+ID=21.25; // in
+C=0.25; // clearance
+B=5; // baffle spacing,in
+PT=1;
+as=((ID*C*B)/(144*PT)); // flow area,ft^2
+printf("\t flow area is : %.3f ft^2 \n",as);
+Gs=(W/as); // mass velocity,lb/(hr)*(ft^2)
+printf("\t mass velocity is : %.2e lb/(hr)*(ft^2) \n",Gs);
+mu1=0.20*2.42; // at 175F,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 : %.2e \n",Res);
+phys=1;
+jH=137; // from fig.28
+c=0.63; // Btu/(lb)*(F),at 175F,from fig.2
+k=0.095; // Btu/(hr)*(ft^2)*(F/ft), from table 4
+Pr=((c)*(mu1)/k)^(1/3); // prandelt number raised to power 1/3
+printf("\t Pr is : %.3f \n",Pr);
+ho=((jH)*(k/De)*(Pr)*1); // using eq.6.15b,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,acetic acid \n");
+Nt=270;
+n=2; // number of passes
+L=16; //ft
+at1=0.268; // 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 : %.3f ft^2 \n",at);
+Gt=(w/(at)); // mass velocity,lb/(hr)*(ft^2)
+printf("\t mass velocity is : %.1e lb/(hr)*(ft^2) \n",Gt);
+mu2=0.85*2.42; // at 120F,lb/(ft)*(hr)
+D=(0.584/12); // ft
+Ret=((D)*(Gt)/mu2); // reynolds number
+printf("\t reynolds number is : %.2e \n",Ret);
+jH=56; // from fig.24
+c=0.51; // Btu/(lb)*(F),at 120F,from fig.2
+k=0.098; // Btu/(hr)*(ft^2)*(F/ft), from table 4
+phyt=1;
+Pr=((c)*(mu2)/k)^(1/3); // prandelt number raised to power 1/3
+printf("\t Pr is : %.3f \n",Pr);
+hi=((jH)*(k/D)*(Pr)*(1^0.14)); // using eq.6.15a,Btu/(hr)*(ft^2)*(F)
+printf("\t hi is : %.0f Btu/(hr)*(ft^2)*(F) \n",hi);
+ID=0.584; // ft
+OD=0.75; //ft
+hio=((hi)*(ID/OD)); //Hio=(hio/phyp), 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 : %.1f Btu/(hr)*(ft^2)*(F) \n",Uc);
+A2=0.1963; // actual surface supplied for each tube,ft^2,from table 10
+A=3*(Nt*L*A2); // ft^2
+printf("\t total surface area is : %.2e ft^2 \n",A);
+UD=((Q)/((A)*(delt)));
+printf("\t actual design overall coefficient is : %.1f Btu/(hr)*(ft^2)*(F) \n",UD);
+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 annulus \n");
+f=0.00155; // friction factor for reynolds number 52200, using fig.29
+s=0.79; // for reynolds number 25300,using table.6
+Ds=21.25/12; // ft
+N=(12*L/B)+1; // number of crosses,using eq.7.43
+printf("\t number of crosses are : %.0f \n",N);
+delPs=((f*(Gs^2)*(Ds)*(3*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=0.00024; // friction factor for reynolds number 158000, using fig.26
+s=1.07;
+D=0.0487; // ft
+delPt=((f*(Gt^2)*(L)*(n*3))/(5.22*(10^10)*(D)*(s)*(phyt))); // using eq.7.45,psi
+printf("\t delPt is : %.1f psi \n",delPt);
+X1=0.063; // X1=((V^2)/(2*g)), for Gt 1060000,using fig.27
+delPr=(3)*((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
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