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/CH13/EX13.3/13_3.sce | 195 ++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 195 insertions(+) create mode 100644 1328/CH13/EX13.3/13_3.sce (limited to '1328/CH13/EX13.3/13_3.sce') diff --git a/1328/CH13/EX13.3/13_3.sce b/1328/CH13/EX13.3/13_3.sce new file mode 100644 index 000000000..50166d3e7 --- /dev/null +++ b/1328/CH13/EX13.3/13_3.sce @@ -0,0 +1,195 @@ +printf("\t example 13.3 \n"); +printf("\t approximate values are mentioned in the book \n"); +printf("\t for condensing range \n"); +V(1)=170.5; // volume of C3,Mol/hr +V(2)=284; // volume of C4,Mol/hr +V(3)=56.8; // volume of C6,Mol/hr +V(4)=341.1; // volume of C7,Mol/hr +V(5)=284; // volume of C8,Mol/hr +Tw=283; // dew point assumption +Tb=120; // bubble point assumption +K(1)=13.75 // at 283F +K(2)=6.18 // at 283F +K(3)=1.60 // at 283F +K(4)=0.825 // at 283F +K(5)=0.452 // at 283F +i=1; +while(i<6) + Z(i)=(V(i)/K(i)); + i=i+1; +end +Vt=V(1)+V(2)+V(3)+V(4)+V(5); +Zt=Z(1)+Z(2)+Z(3)+Z(4)+Z(5); +L(1)=170.5; // volume of C3,Mol/hr +L(2)=284; // volume of C4,Mol/hr +L(3)=56.8; // volume of C6,Mol/hr +L(4)=341.1; // volume of C7,Mol/hr +L(5)=284; // volume of C8,Mol/hr +Kl(1)=4.1 // at 283F +Kl(2)=1.39 // at 283F +Kl(3)=0.17 // at 283F +Kl(4)=0.06 // at 283F +Kl(5)=0.023 // at 283F +i=1; +while(i<6) + Zl(i)=(L(i)*Kl(i)); + printf(" \n V(i) K(i) Z(i) L(i) Kl(i) Zl(i) \n "+string(V(i))+" "+string(K(i))+" "+string(Z(i))+" "+string(L(i))+" "+string(Kl(i))+" "+string(Zl(i))+" \n"); + i=i+1; +end +Lt=L(1)+L(2)+L(3)+L(4)+L(5); +Zlt=Zl(1)+Zl(2)+Zl(3)+Zl(4)+Zl(5); +printf("\t total volume in vapour phase : %.1f \n",Vt); +printf("\t total Zt in vapour phase : %.1f \n",Zt); +printf("\t total volume in liquid phase : %.1f \n",Lt); +printf("\t total Zlt in liquid phase : %.1f \n",Zlt); +// Range: 283 to 270°F +// Trial: Assume V /L = 4.00. +R=4; // R=(V/L), assumption +K(1)=12.75 // at 270F +K(2)=5.61 // at 270F +K(3)=1.40 // at 270F +K(4)=0.705 // at 270F +K(5)=0.375 // at 270F +i=1; +Y(i)=V(i); +while(i<6) + P(i)=(K(i)*R); + L1(i)=(V(i)/(1+P(i))); // V(i)=Y(i) + printf(" \n Y(i) K(i) P(i) L1(i) \n "+string(V(i))+" "+string(K(i))+" "+string(P(i))+" "+string(L1(i))+" \n"); + i=i+1; +end +L1t=L1(1)+L1(2)+L1(3)+L1(4)+L1(5); +V1t=(Vt-L1t); +R1=(V1t/L1t); +printf("\t total liquid at 270F : %.0f \n",L1t); +printf("\t total vapour at 270F : %.0f \n",V1t); +printf("\t R1 is : %.0f \n",R1); +// If the assumed and calculated values of V /L had not checked, a new value would have been assumed. +printf("\t for condensing curve \n"); +R270=4; // V/L at 270, from table 13.2 +R270=1.567; // V/L at 250, from table 13.2 +R270=0.916; // V/L at 230, from table 13.2 +R270=0.520; // V/L at 200, from table 13.2 +R270=0.226; // V/L at 160, from table 13.2 +H270=30835500; // 4th table in solution ,enthalpies calculated from fig 10 +printf("\t heat load at 270F is : %.0f Btu/hr \n",H270); +H250=27042400; // 5th table in solution ,enthalpies calculated from fig 10 +printf("\t heat load at 250F is : %.0f Btu/hr \n",H250); +Q=H270-H250; +printf("\t heat load for interval 270-250F : %.0f Btu/hr \n",Q); +qt=21203000; // 6th table in solution, calculated from fig 10 +printf("\t heat load for entire range is : %.0f Btu/hr \n",qt); +M=210410; // M=sum(U*A), 6th table in solution, calculated from fig 10 +w=(qt/(120-80)); +printf("\t water flow rate : %.1e lb/hr \n",w); +W=95450; // flow rate of feed,lb/hr +delt=(qt/M); +printf("\t weighted delt is : %.1f F \n",delt); +q1=[0 3.4765 7.2696 10.109 13.468 17.399 21.203]; +T1=[283 270 250 230 200 160 120]; +plot2d(q1,T1,style=3,rect=[0,0,25,300]); +q2=[0 21.203]; +T2=[283 120]; +plot2d(q2,T2,style=5,rect=[0,0,25,300]); +xtitle("condensing curve","heat load,Btu/hr","temperature,F"); +legend("green-differential vapour","red-vapour"); +printf("\t calculation of the exchanger \n"); +T1=283; // inlet hot fluid,F +T2=120; // outlet hot fluid,F +t1=80; // inlet cold fluid,F +t2=120; // outlet cold fluid,F +L=16; +Nt=774; +n=4; +row=62.5; +Qs=21203000; // Btu/hr +Qw=(w*1*(120-80)); +printf("\t heat absorbed by water : %.4e Btu/hr \n",Qw); +Mavg=84; // This corresponds very closely to hexane (mol. Wt. = 86.2) whose properties will be used throughout. +Qc=W*(0.6/2)*(283-120); +printf("\t condensate sensible heat load: %.2e Btu/hr \n",Qc); +S=(Qc*(100/Qs)); +printf("\t submergence : %.0f \n",S); +Tc=((T1+T2)/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:shellside,vapour \n"); +Nts=(774*(1-.22)); // as submergence is 22% +printf("\t unmerged tubes : %.0f \n",Nts); +Gs=(W/(L*(Nts^(2/3)))); // eq 12.43 +printf("\t Gs is : %.1f \n",Gs); +Ho=200; // assumption +printf("\t cold fluid:inner tube side,water \n"); +at1=0.302; // flow area, 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 : %.1e lb/(hr)*(ft^2) \n",Gt); +V=(Gt/(3600*row)); +printf("\t V is : %.2f fps \n",V); +hi=1355; // fig 25 +ID=0.62; +OD=0.75; +hio=((hi)*(ID/OD)); //Hio=(hio/phyp), using eq.6.5 +printf("\t Correct hio to the surface at the OD is : %.2e Btu/(hr)*(ft^2)*(F) \n",hio); +tw=(tc)+(((Ho)/(hio+Ho))*(Tc-tc)); // from eq.5.31 +printf("\t tw is : %.0f F \n",tw); +tf=(Tc+tw)/(2); // from eq 12.19 +printf("\t tf is : %.0f F \n",tf); +kf=0.077; //table 4, Btu/(hr)*(ft^2)*(F/ft) +sf=0.60; // from table 6 +muf=0.21; // cp, from fig 14 +ho=206; // Btu/(hr)*(ft^2)*(F), from fig 12.9 +printf("\t Correct ho to the surface at the OD is : %.0f Btu/(hr)*(ft^2)*(F) \n",ho); +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); +Ac=(Qw/(174*delt)); +printf("\t clean surface required for condensation : %.2e ft^2 \n",Ac); +As=1210*0.22; +printf("\t clean surface required for subcooling : %.0f ft^2 \n",As); +AG=As+Ac; +printf("\t total clean surface : %.0f ft^2 \n",AG); +UC=(Qw/(AG*delt)); +printf("\t weighted clean overall coefficient : %.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 : %.2e ft^2 \n",A); +UD=((Qw)/((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 : %.5f (hr)*(ft^2)*(F)/Btu \n",Rd); +printf("\t pressure drop for annulus \n"); +B=30; +as=33*0.25*(30/144)*1; // eq 7.1 +printf("\t as is : %.2f ft^2 \n",as); +Gs=(W/as); +printf("\t Gs is : %.2e lb/(hr)*(ft^2) \n",Gs); // eq 7.2 +mu1=0.0218; // at 283F +De=0.0608; // ft, from fig 15 +Res=(De*Gs)/(mu1); +printf("\t reynolds number is : %.2e \n",Res); +f=0.00125; // fig 29 +N=(12*L/B); // eq 7.43 +printf("\t number crosses : %.0f \n",N); +row1=0.527; //lb/ft^3 +s=0.00844; +Ds=2.75; // ft +delPs=((f*(Gs^2)*(Ds)*(N))/(5.22*(10^10)*(De)*(s)*(1)))/(2); // using eq 12.47,psi +printf("\t delPs is : %.1f psi \n",delPs); +printf("\t pressure drop for inner pipe \n"); +mu2=1.74; // fig 14 +D=0.0517; // ft +s=1; +Ret=(D*Gt/mu2); +printf("\t reynolds number : %.2e \n",Ret); +f=0.00019; // ft^2/in^2 +delPt=((f*(Gt^2)*(L)*(n))/(5.22*(10^10)*(D)*(1)*(1))); // using eq.7.45,psi +printf("\t delPt is : %.1f psi \n",delPt); +X1=0.23; // X1=((V^2)/(2*g)),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 10 psi \n"); +// end -- cgit