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Diffstat (limited to '1309/CH9/EX9.5/ch9_5.sce')
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diff --git a/1309/CH9/EX9.5/ch9_5.sce b/1309/CH9/EX9.5/ch9_5.sce new file mode 100755 index 000000000..1630de0cb --- /dev/null +++ b/1309/CH9/EX9.5/ch9_5.sce @@ -0,0 +1,93 @@ +clc; +clear; +printf("\t\t\tChapter9_example5\n\n\n"); +// Determination of the outlet temperature of the distilled water and the pressure drop for each stream. +// properties of (distilled) water at 104°F from appendix table CII +rou_1= 0.994*62.4; // density in lbm/ft^3 +cp_1=0.998; // specific heat BTU/(lbm-degree Rankine) +v_1= 0.708e-5; // viscosity in ft^2/s +kf_1 = 0.363 ; // thermal conductivity in BTU/(hr.ft.degree Rankine) +a_1 = 5.86e-3; // diffusivity in ft^2/hr +Pr_1 = 4.34; // Prandtl Number +m_1=170000; // mass flow rate in lbm/hr +T1=110; // temperature in degree F +// properties of (raw) water at 68°F from Appendix Table C11 +rou_2= 62.4; // density in lbm/ft^3 +cp_2=0.9988; // specific heat BTU/(lbm-degree Rankine) +v_2= 1.083e-5; // viscosity in ft^2/s +kf_2 = 0.345 ; // thermal conductivity in BTU/(hr.ft.degree Rankine) +a_2 = 5.54e-3; // diffusivity in ft^2/hr +Pr_2 = 7.02; // Prandtl Number +m_2=150000; // mass flow rate in lbm/hr +t1=65; // temperature in degree F +// specifications of 3/4-in-OD, 18-BWG tubes, from table 9.2 +OD=3/(4*12); +ID=0.652/12; +OD_p=1.375/12; +Nt=224; // from table 9.3 +Np=2; // no. of tube passes +// Shell dimensions and other miscellaneous data +Ds=17.25/12; +Nb=15; // no. of baffles +B=1; +sT=15/(16*12); +C=sT-OD; +// flow areas +At=(Nt*%pi*ID^2)/(4*Np); +As=(Ds*C*B)/sT; +printf("\nThe areas are %.3f sq.ft and %.3f sq.ft",At,As); +if At>As then + printf("\nThe distilled water flows through the tubes"); + else printf("\nThe raw water flows through the tubes"); +end +// Shell Equivalent Diameter +De=4*[(sT/2)*(0.86*sT)-(%pi*OD^2/8)]/(%pi*OD/2); +printf("\nThe equivalent diameter is %.4f ft",De); +// Reynolds Numbers +Re_s=(m_1/3600)*(De)/(v_1*rou_1*As); +printf("\nThe Reynolds Number for raw water is %.2e",Re_s); +Re_t=(m_2/3600)*(ID)/(v_2*rou_2*At); +printf("\nThe Reynolds Number for distilled water is %.2e",Re_t); +// Nusselt numbers +Nu_t=0.023*(Re_t)^(4/5)*(Pr_2)^0.4; +Nu_s=0.36*(Re_s)^(.55)*(Pr_1)^(1/3); +printf("\nThe Nusselt number for raw water is %.1f",Nu_t); +printf("\nThe Nusselt number for distilled water is %.1f",Nu_s); +h_ti=Nu_t*kf_2/ID; +h_to=h_ti*ID/OD; +h_s=Nu_s*kf_1/De; +printf("\nThe convective coefficient for raw water based on inner diameter is %d BTU/(hr.sq.ft.degree R)",h_ti); +printf("\nThe convective coefficient for raw water based on outer diameter is %d BTU/(hr.sq.ft.degree R)",h_to); +printf("\nThe convective coefficient for distilled water is %d BTU/(hr.sq.ft.degree R)",h_s); +// Exchanger Coefficient +Uo=1/((1/h_to)+(1/h_s)); +printf("\nThe overall exchanger coefficient is %d BTU/(hr.sq.ft.degree R)",Uo); +R=(m_2*cp_2)/(m_1*cp_1); +L=16; +Ao=Nt*%pi*OD*L; +printf("\nThe ratio is %.3f and area is %.1f sq.ft",R,Ao); +UoAo_mccp=(Uo*Ao)/(m_2*cp_2); +printf("\n(UoAo)/(McCpc)=%.2f",UoAo_mccp); +S=0.58; //value of S from fig. 9.13 Ten Broeck graph corresponding to the value of (UoAo)/(McCpc) +t2=S*(T1-t1)+t1; +T2=T1-R*(t2-t1); +printf("\nt2=%.1f degree F\nT2=%.1f degree F",t2,T2); +//friction factors +ft=0.029; //friction factor for raw water fom figure 6.14 corresponding to Reynolds Number calculated above +printf("\nFriction factor for raw water fom figure 6.14 corresponding to Reynolds Number calculated above is %.3f",ft); +fs=0.281; //friction factor for distilled water fom figure 6.14 corresponding to Reynolds Number calculated above +printf("\nFriction factor for distilled water fom figure 6.14 corresponding to Reynolds Number calculated above is %.3f",fs); +// Velocities +V_t=(m_2/3600)/(rou_2*At); +V_s=(m_1/3600)/(rou_1*As); +printf("\nThe velocity of raw water is %.2f ft/s",V_t); +printf("\nThe velocity of distilled water is %.2f ft/s",V_s); +// pressure drops +gc=32.2; +dP_t=(rou_2*V_t^2)*((ft*L*Np/ID)+4*Np)/(2*gc); +dP_s=((rou_1*V_s^2)*(fs*Ds*(Nb+1)))/(2*gc*De); +printf("\nThe pressure drop for tube side is %.1f lbf/sq.ft = %.1f psi",dP_t,dP_t/147); +printf("\nThe pressure drop for shell side is %.1f lbf/sq.ft = %.1f psi",dP_s,dP_s/147); +printf("\n\t\t\tSummary of Requested Information\n"); +printf("\nOutlet Temperatures:\n\tRaw Water: %.1f degree F\n\tDistilled Water: %.1f degree F\n",t2,T2); +printf("\nPressure Drops:\n\tRaw Water: %.1f ddegree F\n\tDistilled Water: %.1f degree F\n",dP_t/147,dP_s/147); |