From 7f60ea012dd2524dae921a2a35adbf7ef21f2bb6 Mon Sep 17 00:00:00 2001 From: prashantsinalkar Date: Tue, 10 Oct 2017 12:27:19 +0530 Subject: initial commit / add all books --- 1328/CH6/EX6.1/6_1.sce | 119 +++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 119 insertions(+) create mode 100644 1328/CH6/EX6.1/6_1.sce (limited to '1328/CH6/EX6.1/6_1.sce') diff --git a/1328/CH6/EX6.1/6_1.sce b/1328/CH6/EX6.1/6_1.sce new file mode 100644 index 000000000..5d43b8d65 --- /dev/null +++ b/1328/CH6/EX6.1/6_1.sce @@ -0,0 +1,119 @@ +printf("\t example 6.1 \n"); +printf("\t approximate values are mentioned in the book \n"); +T1=160; // inlet hot fluid,F +T2=100; // outlet hot fluid,F +t1=80; // inlet cold fluid,F +t2=120; // outlet cold fluid,F +w=9820; // lb/hr +printf("\t 1.for heat balance \n"); +printf("\t for benzene \n"); +tav=((t1+t2)/2); // F +printf("\t average temperature of benzene is : %.0f F \n",tav); +c=0.425; // Btu/(lb)*(F) +Q=((w)*(c)*(t2-t1)); // Btu/hr +printf("\t total heat required for benzene is : %.2e Btu/hr \n",Q); +printf("\t for toulene \n"); +Tav=((T1+T2)/2); //F +printf("\t average temperature of toulene is : %.0f F \n",Tav); +c=0.44; // Btu/(lb)*(F) +W=((Q)/((c)*(T1-T2))); // lb/hr +printf("\t W is :%.2e lb/hr \n",W); +printf("\t 2.LMTD \n"); +printf("\t for counter current flow \n"); +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); +printf("\t 3.caloric temperatures \n"); +printf("\t both streams will show that neither is viscous at the cold terminal (the viscosities less than 1 centipoise) and the temperature ranges and temperature difference are moderate. The coefficients may accordingly be evaluated from properties at the arithmetic mean, and the value of (mu/muw)^0.14 may be assumed equal to 1.0 \n"); +tav=((t1+t2)/2); // F +printf("\t average temperature of benzene is : %.0f F \n",tav); +Tav=((T1+T2)/2); //F +printf("\t average temperature of toulene is : %.0f F \n",Tav); +printf("\t hot fluid:annulus,toulene \n"); +D1=0.138; // ft +D2=0.1725; // ft +aa=((%pi)*(D2^2-D1^2)/4); // flow area,ft^2 +printf("\t flow area is : %.5f ft^2 \n",aa); +De=(D2^2-D1^2)/D1; // equiv diameter,ft +printf("\t equiv diameter is : %.4f ft \n",De); +Ga=(W/aa); // mass velocity,lb/(hr)*(ft^2) +printf("\t mass velocity is : %.2e lb/(hr)*(ft^2) \n",Ga); +mu1=0.41*2.42; // at 130 F,lb/(ft)*(hr) +Rea=((De)*(Ga)/mu1); // reynolds number +printf("\t reynolds number is : %.1e \n",Rea); +jH=167; // from fig.24 +c=0.44; // Btu/(lb)*(F),at 130F +k=0.085; // 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)*(1^0.14)); // 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 pipe,benzene \n"); +D=0.115; // ft +ap=((%pi)*(D^2)/4); // flow area, ft^2 +printf("\t flow area is : %.4f ft^2 \n",ap); +Gp=(w/ap); // mass velocity,lb/(hr)*(ft^2) +printf("\t mass velocity is : %.2e lb/(hr)*(ft^2) \n",Gp); +mu2=0.5*2.42; // at 130 F,lb/(ft)*(hr) +Rep=((D)*(Gp)/mu2); // reynolds number +printf("\t reynolds number is : %.2e \n",Rep); +jH=236; // from fig.24 +c=0.425; // Btu/(lb)*(F),at 130F +k=0.091; // Btu/(hr)*(ft^2)*(F/ft), from table 4 +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 individual heat transfer coefficient is : %.0f Btu/(hr)*(ft^2)*(F) \n",hi); +ID=1.38; // ft +OD=1.66; //ft +hio=((hi)*(ID/OD)); // using eq.6.5 +printf("\t Correct hi 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); +Rd=0.002; // required by problem,(hr)*(ft^2)*(F)/Btu +UD=((Uc)/((1)+(Uc*Rd))); // design overall coefficient,Btu/(hr)*(ft^2)*(F) +printf("\t design overall coefficient is : %.0f Btu/(hr)*(ft^2)*(F) \n",UD); +A=((Q)/((UD)*(LMTD))); // required surface,ft^2 +printf("\t required surface is : %.1f ft^2 \n",A); +A1=0.435; // From Table 11 for 1(1/4)in IPS standard pipe there are 0.435 ft2 of external surface per foot length,ft^2 +L=(A/A1); // required length;lin ft +printf("\t required length is : %.0f lin ft \n",L); +printf("\t This may be fulfilled by connecting three 20-ft hairpins in series \n"); +A2=120*0.435; // actual surface supplied,ft^2 +printf("\t actual surface supplied is : %.1f ft^2 \n",A2); +UD=((Q)/((A2)*(LMTD))); +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 : %.4f (hr)*(ft^2)*(F)/Btu \n",Rd); +printf("\t pressure drop for annulus \n"); +De1=(D2-D1); //ft +printf("\t De1 is : %.4f ft \n",De1); +Rea1=((De1)*(Ga)/mu1); // reynolds number +printf("\t reynolds number is : %.2e \n",Rea1); +f=(0.0035)+((0.264)/(Rea1^0.42)); // friction factor, using eq.3.47b +printf("\t friction factor is : %.4f \n",f); +s=0.87; +row=62.5*0.87; // from table 6 +delFa=((4*f*(Ga^2)*L)/(2*4.18*(10^8)*(row^2)*(De1))); // ft +printf("\t delFa is : %.1f ft \n",delFa); +V=((Ga)/(3600*row)); //fps +printf("\t V is : %.2f fps \n",V); +Fl=((3*(V^2))/(2*32.2)); //ft +printf("\t Fl is : %.1f ft \n",Fl); +delPa=((delFa+Fl)*(row)/144); // psi +printf("\t delPa is : %.1f psi \n",delPa); +printf("\t allowable delPa is 10 psi \n"); +printf("\t pressure drop for inner pipe \n"); +f=(0.0035)+((0.264)/(Rep^0.42)); // friction factor, using eq.3.47b +printf("\t friction factor is : %.4f \n",f); +s=0.88; +row=62.5*0.88; // from table 6 +delFp=((4*f*(Gp^2)*L)/(2*4.18*(10^8)*(row^2)*(D))); // ft +printf("\t delFp is : %.1f ft \n",delFp); +delPp=((delFp)*(row)/144); // psi +printf("\t delPp is : %.1f psi \n",delPp); +printf("\t allowable delPp is 10 psi \n"); +//end -- cgit