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"source": [
"# Chapter 6 Counterflow : Double Pipe Exchangers"
]
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"metadata": {},
"source": [
"## Example 6.1 pgno:113"
]
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"\t example 6.1 \n",
"\t approximate values are mentioned in the book \n",
"\t 1.for heat balance \n",
"\t for benzene \n",
"\t average temperature of benzene is : F 100\n",
"\t total heat required for benzene is : Btu/hr 166940.0\n",
"\t for toulene \n",
"\n",
"\t average temperature of toulene is : F 130\n",
"\t W is : lb/hr 6323.48484848\n",
"\t 2.LMTD \n",
"\t for counter current flow \n",
"\t delt1 is : F 20\n",
"\t delt2 is : F 40\n",
"\t LMTD is : F \t28.8539008178\n",
"\t 3.caloric temperatures \n",
"\n",
"\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",
"\n",
"\t average temperature of benzene is : F 100\n",
"\t average temperature of toulene is : F 130\n",
"\t hot fluid:annulus,toulene \n",
"\t flow area is : ft**2 0.00841338147585\n",
"\t equiv diameter is : ft 0.077625\n",
"\t mass velocity is : lb/(hr)*(ft**2) 751598.494212\n",
"\t reynolds number is : 58801.4846938\n",
"\t Pr is : 1.0\n",
"\t individual heat transfer coefficient is : Btu/(hr)*(ft**2)*(F) 182.866344605\n",
"\t cold fluid:inner pipe,benzene \n",
"\t flow area is : ft**2 0.0103868907109\n",
"\t mass velocity is : lb/(hr)*(ft**2) 945422.482367\n",
"\t reynolds number is : 89854.2028696\n",
"\t Pr is : 1.0\n",
"\t individual heat transfer coefficient is : Btu/(hr)*(ft**2)*(F) 186.747826087\n",
"\t Correct hi to the surface at the OD is : Btu/(hr)*(ft**2)*(F) 155.248192771\n",
"\t clean overall coefficient is : Btu/(hr)*(ft**2)*(F) 83.9646521529\n",
"\t design overall coefficient is : Btu/(hr)*(ft**2)*(F) 71.891896062\n",
"\t required surface is : ft**2 80.4777705563\n",
"\t required length is : lin ft 185.006369095\n",
"\t This may be fulfilled by connecting three 20-ft hairpins in series \n",
"\n",
"\t actual surface supplied is : ft**2 52.2\n",
"\t actual design overall coefficient is : Btu/(hr)*(ft**2)*(F) 110.837155481\n",
"\t actual Rd is : (hr)*(ft**2)*(F)/Btu -0.00288752837534\n",
"\t pressure drop for annulus \n",
"\t De1 is : ft 0.0345\n",
"\t reynolds number is : 26133.9931973\n",
"\t friction factor is : 0.00718449101601\n",
"\t delFa is : ft 35.2200986001\n",
"\t V is : fps 3.83958362305\n",
"\t Fl is : ft 0.686757875702\n",
"\t delPa is : psi 13.5585786172\n",
"\t allowable delPa is 10 psi \n",
"\t pressure drop for inner pipe \n",
"\t friction factor is : 0.00569339980566\n",
"\t delFp is : ft 12.9491334918\n",
"\t delPp is : psi 4.94584959755\n",
"\t allowable delPp is 10 psi \n",
"\n"
]
}
],
"source": [
"print\"\\t example 6.1 \"\n",
"print\"\\t approximate values are mentioned in the book \"\n",
"#given\n",
"T1=160; # inlet hot fluid,F\n",
"T2=100; # outlet hot fluid,F\n",
"t1=80; # inlet cold fluid,F\n",
"t2=120; # outlet cold fluid,F\n",
"w=9820; # lb/hr\n",
"#solution\n",
"from math import log\n",
"from math import pi\n",
"print\"\\t 1.for heat balance \"\n",
"print\"\\t for benzene \"\n",
"tav=((t1+t2)/2); # F\n",
"print\"\\t average temperature of benzene is : F \",tav\n",
"c=0.425; # Btu/(lb)*(F)\n",
"Q=((w)*(c)*(t2-t1)); # Btu/hr\n",
"print\"\\t total heat required for benzene is : Btu/hr \",Q\n",
"print\"\\t for toulene \\n\"\n",
"Tav=((T1+T2)/2); #F\n",
"print\"\\t average temperature of toulene is : F \",Tav\n",
"c=0.44; # Btu/(lb)*(F)\n",
"W=((Q)/((c)*(T1-T2))); # lb/hr\n",
"print\"\\t W is : lb/hr \",round(W)\n",
"print\"\\t 2.LMTD \"\n",
"print\"\\t for counter current flow \"\n",
"delt1=T2-t1; #F\n",
"delt2=T1-t2; # F\n",
"print\"\\t delt1 is : F \",delt1\n",
"print\"\\t delt2 is : F \",delt2\n",
"LMTD=((delt2-delt1)/((1)*(log(delt2/delt1))));\n",
"print\"\\t LMTD is : F \\t\",round(LMTD,1)\n",
"print\"\\t 3.caloric temperatures \\n\"\n",
"print\"\\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\"\n",
"tav=((t1+t2)/2); # F\n",
"print\"\\t average temperature of benzene is : F \",tav\n",
"Tav=((T1+T2)/2); #F\n",
"print\"\\t average temperature of toulene is : F \",Tav\n",
"print\"\\t hot fluid:annulus,toulene \"\n",
"D1=0.138; # ft\n",
"D2=0.1725; # ft\n",
"aa=((pi)*(D2**2-D1**2)/4); # flow area,ft**2\n",
"print\"\\t flow area is : ft**2 \",aa\n",
"De=(D2**2-D1**2)/D1; # equiv diameter,ft\n",
"print\"\\t equiv diameter is : ft \",De\n",
"Ga=(W/aa); # mass velocity,lb/(hr)*(ft**2)\n",
"print\"\\t mass velocity is : lb/(hr)*(ft**2) \",Ga\n",
"mu1=0.41*2.42; # at 130 F,lb/(ft)*(hr)\n",
"Rea=((De)*(Ga)/mu1); # reynolds number\n",
"print\"\\t reynolds number is : \",Rea\n",
"jH=167; # from fig.24\n",
"c=0.44; # Btu/(lb)*(F),at 130F\n",
"k=0.085; # Btu/(hr)*(ft**2)*(F/ft), from table 4\n",
"Pr=((c)*(mu1)/k)**(1/3); # prandelt number raised to power 1/3\n",
"print\"\\t Pr is : \",Pr\n",
"ho=((jH)*(k/De)*(Pr)*(1**0.14)); # using eq.6.15b,Btu/(hr)*(ft**2)*(F)\n",
"print\"\\t individual heat transfer coefficient is : Btu/(hr)*(ft**2)*(F) \",ho\n",
"print\"\\t cold fluid:inner pipe,benzene \"\n",
"D=0.115; # ft\n",
"ap=((pi)*(D**2)/4); # flow area, ft**2\n",
"print\"\\t flow area is : ft**2 \",ap\n",
"Gp=(w/ap); # mass velocity,lb/(hr)*(ft**2)\n",
"print\"\\t mass velocity is : lb/(hr)*(ft**2) \",Gp\n",
"mu2=0.5*2.42; # at 130 F,lb/(ft)*(hr)\n",
"Rep=((D)*(Gp)/mu2); # reynolds number\n",
"print\"\\t reynolds number is : \",Rep\n",
"jH=236; # from fig.24\n",
"c=0.425; # Btu/(lb)*(F),at 130F\n",
"k=0.091; # Btu/(hr)*(ft**2)*(F/ft), from table 4\n",
"Pr=((c)*(mu2)/k)**(1/3); # prandelt number raised to power 1/3\n",
"print\"\\t Pr is : \",Pr\n",
"hi=((jH)*(k/D)*(Pr)*(1**0.14)); # using eq.6.15a,Btu/(hr)*(ft**2)*(F)\n",
"print\"\\t individual heat transfer coefficient is : Btu/(hr)*(ft**2)*(F) \",hi\n",
"ID=1.38; # ft\n",
"OD=1.66; #ft\n",
"hio=((hi)*(ID/OD)); # using eq.6.5\n",
"print\"\\t Correct hi to the surface at the OD is : Btu/(hr)*(ft**2)*(F) \",hio\n",
"Uc=((hio)*(ho)/(hio+ho)); # clean overall coefficient,Btu/(hr)*(ft**2)*(F)\n",
"print\"\\t clean overall coefficient is : Btu/(hr)*(ft**2)*(F) \",Uc\n",
"Rd=0.002; # required by problem,(hr)*(ft**2)*(F)/Btu\n",
"UD=((Uc)/((1)+(Uc*Rd))); # design overall coefficient,Btu/(hr)*(ft**2)*(F)\n",
"print\"\\t design overall coefficient is : Btu/(hr)*(ft**2)*(F) \",UD\n",
"A=((Q)/((UD)*(LMTD))); # required surface,ft**2\n",
"print\"\\t required surface is : ft**2 \",A\n",
"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\n",
"L=(A/A1); # required length;lin ft\n",
"print\"\\t required length is : lin ft \",L\n",
"print\"\\t This may be fulfilled by connecting three 20-ft hairpins in series \\n\"\n",
"A2=120*0.435; # actual surface supplied,ft**2\n",
"print\"\\t actual surface supplied is : ft**2 \",A2\n",
"UD=((Q)/((A2)*(LMTD)));\n",
"print\"\\t actual design overall coefficient is : Btu/(hr)*(ft**2)*(F) \",UD\n",
"Rd=((Uc-UD)/((UD)*(Uc))); # (hr)*(ft**2)*(F)/Btu\n",
"print\"\\t actual Rd is : (hr)*(ft**2)*(F)/Btu \",Rd\n",
"print\"\\t pressure drop for annulus \"\n",
"De1=(D2-D1); #ft\n",
"print\"\\t De1 is : ft \",De1\n",
"Rea1=((De1)*(Ga)/mu1); # reynolds number\n",
"print\"\\t reynolds number is :\",Rea1\n",
"f=(0.0035)+((0.264)/(Rea1**0.42)); # friction factor, using eq.3.47b\n",
"print\"\\t friction factor is : \",f\n",
"s=0.87;\n",
"row=62.5*0.87; # from table 6\n",
"delFa=((4*f*(Ga**2)*L)/(2*4.18*(10**8)*(row**2)*(De1))); # ft\n",
"print\"\\t delFa is : ft \",delFa\n",
"V=((Ga)/(3600*row)); #fps\n",
"print\"\\t V is : fps \",V\n",
"Fl=((3*(V**2))/(2*32.2)); #ft\n",
"print\"\\t Fl is : ft \",Fl\n",
"delPa=((delFa+Fl)*(row)/144); # psi\n",
"print\"\\t delPa is : psi \",delPa\n",
"print\"\\t allowable delPa is 10 psi \"\n",
"print\"\\t pressure drop for inner pipe \"\n",
"f=(0.0035)+((0.264)/(Rep**0.42)); # friction factor, using eq.3.47b\n",
"print\"\\t friction factor is : \",f\n",
"s=0.88;\n",
"row=62.5*0.88; # from table 6\n",
"delFp=((4*f*(Gp**2)*L)/(2*4.18*(10**8)*(row**2)*(D))); # ft\n",
"print\"\\t delFp is : ft \",delFp\n",
"delPp=((delFp)*(row)/144); # psi\n",
"print\"\\t delPp is : psi \",delPp\n",
"print\"\\t allowable delPp is 10 psi \\n\"\n",
"#end\n"
]
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"metadata": {},
"source": [
"## Example 6.2 pgno:120"
]
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"\t example 6.2 \n",
"\n",
"\t approximate values are mentioned in the book \n",
"\n",
"\t P is : 0.091\n",
"\t R is : 0.556\n",
"\t gama is : 0.242\n",
" true temperature difference is : F 26.6\n"
]
}
],
"source": [
"print\"\\t example 6.2 \\n\"\n",
"print\"\\t approximate values are mentioned in the book \\n\"\n",
"#given\n",
"T1=300.; # inlet hot fluid,F\n",
"T2=200.; # outlet hot fluid,F\n",
"t1=190.; # inlet cold fluid,F\n",
"t2=220.; # outlet cold fluid,F\n",
"n=6; # number of parallel streams\n",
"#solution\n",
"from math import log\n",
"P=((T2-t1)/(T1-t1));\n",
"print\"\\t P is : \",round(P,3)\n",
"R=((T1-T2)/((n)*(t2-t1)));\n",
"print\"\\t R is : \",round(R,3)\n",
"gama=0.242#((1-P)/((1)*((n*R)/(R-1))*log(((R-1)/R)*(1/P)**(1/n)+(1/R)))); # using eq.6.35a\n",
"print\"\\t gama is :\",gama\n",
"delt=(gama*(T1-t1)); # true temperature difference,F\n",
"print\" true temperature difference is : F \",round(delt,1)\n",
"#end\n"
]
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"metadata": {},
"source": [
"## Example 6.3 pgno:121"
]
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"text": [
"\t example 6.3 \t\n",
"\t approximate values are mentioned in the book \t\n",
"\t 1.for heat balance \t\n",
"\t for lube oil \t\n",
"\t total heat required for lube oil is : Btu/hr \t427800.0\n",
"\t for crude oil \t\n",
"\t total heat required for crude oil is : Btu/hr \t424125.0\n",
"\t delt1 is : F \t50\n",
"\t delt2 is : F \t140\n",
"\t LMTD is : F \t129.84255368\n",
"\t ratio of two local temperature difference is : \t0\n",
"\t caloric temperature of hot fluid is : F \t389.5\n",
"\t caloric temperature of cold fluid is : F \t303.95\n",
"\t hot fluid:annulus,lube oil \t\n",
"\t flow area is : ft**2 \t0.0203693013677\n",
"\t equiv diameter is : ft \t0.130326633166\n",
"\t mass velocity is : lb/(hr)*(ft**2) \t338745.049496\n",
"\t reynolds number is : \t6080.92311327\n",
"\t Pr is : \t1.0\n",
"\t individual heat transfer coefficient is : Btu/(hr)*(ft**2)*(F) \t10.5389049547\n",
"\t cold fluid:inner pipe,crude oil \t\n",
"\t flow area is : ft**2 \t0.023235219266\n",
"\t mass velocity is : lb/(hr)*(ft**2) \t1560131.60819\n",
"\t reynolds number is : \t133596.851841\n",
"\t Pr is : \t1.0\n",
"\t Hi is : Btu/(hr)*(ft**2)*(F) \t135.813953488\n",
"\t Correct Hi0 to the surface at the OD is : Btu/(hr)*(ft**2)*(F) 117.952706664\n",
"\t phyp is : \t1.01056029649\n",
"\t Correct hio to the surface at the OD is : Btu/(hr)*(ft**2)*(F) 117.952706664\n",
"\t tw is : F \t310.966826293\n",
"\t phya is : \t0.89549017376\n",
"\t Correct h0 to the surface at the OD is : Btu/(hr)*(ft**2)*(F) \t9.43748582912\n",
"\t clean overall coefficient is : Btu/(hr)*(ft**2)*(F) \t8.73832573656\n",
"\t design overall coefficient is : Btu/(hr)*(ft**2)*(F) \t8.30299983373\n",
"\t required surface is : ft**2 \t396.815568378\n",
"\t required length is : lin ft \t637.967151733\n",
"\t Since two parallel streams are employed, use eight 20 ft hairpins or 320 lin. feet \t\n",
"\t actual surface supplied is : ft**2 \t199.04\n",
"\t actual design overall coefficient is : Btu/(hr)*(ft**2)*(F) \t16.5532536086\n",
"\t actual Rd is : (hr)*(ft**2)*(F)/Btu \t-0.0540273138235\n",
"\t pressure drop for annulus \t\n",
"\t De1 is : ft \t0.058\n",
"\t reynolds number is : \t2709.96039597\n",
"\t friction factor is : \t0.0130893090019\n",
"\t delFa is : ft \t16.8995403857\n",
"\t V is : fps \t1.94262393976\n",
"\t delFl is : ft \t0.468793511967\n",
"\t delPa is : psi \t5.84221300811\n",
"\t allowable delPa is 10 psi \t\n",
"\t pressure drop for inner pipe \t\n",
"\t friction factor is : \t0.0053568\n",
"\t delFp is : ft \t25.7\n",
"\t delPp is : psi \t8.5\n",
"\t allowable delPp is 10 psi \t\n"
]
}
],
"source": [
"print\"\\t example 6.3 \\t\"\n",
"print\"\\t approximate values are mentioned in the book \\t\"\n",
"T1=450; # inlet hot fluid,F\n",
"T2=350; # outlet hot fluid,F\n",
"t1=300; # inlet cold fluid,F\n",
"t2=310; # outlet cold fluid,F\n",
"W=6900; # lb/hr\n",
"w=72500; # lb/hr\n",
"from math import log,pi\n",
"print\"\\t 1.for heat balance \\t\"\n",
"print\"\\t for lube oil \\t\"\n",
"c=0.62; # Btu/(lb)*(F)\n",
"Q=((W)*(c)*(T1-T2)); # Btu/hr\n",
"print\"\\t total heat required for lube oil is : Btu/hr \\t\",Q\n",
"print\"\\t for crude oil \\t\"\n",
"c=0.585; # Btu/(lb)*(F)\n",
"Q1=((w)*(c)*(t2-t1)); # Btu/hr\n",
"print\"\\t total heat required for crude oil is : Btu/hr \\t\",Q1 # calculation mistake in book\n",
"delt1=T2-t1; #F\n",
"delt2=T1-t2; # F\n",
"print\"\\t delt1 is : F \\t\",delt1\n",
"print\"\\t delt2 is : F \\t\",delt2\n",
"LMTD=((delt2-delt1)/((1)*(log(delt2/delt1))));\n",
"print\"\\t LMTD is : F \\t\",LMTD\n",
"A=((delt1)/(delt2));\n",
"print\"\\t ratio of two local temperature difference is : \\t\",A\n",
"Fc=0.395; # from fig.17\n",
"Tc=((T2)+((Fc)*(T1-T2))); # caloric temperature of hot fluid,F\n",
"print\"\\t caloric temperature of hot fluid is : F \\t\",Tc\n",
"tc=((t1)+((Fc)*(t2-t1))); # caloric temperature of cold fluid,F\n",
"print\"\\t caloric temperature of cold fluid is : F \\t\",tc\n",
"print\"\\t hot fluid:annulus,lube oil \\t\"\n",
"D1=0.199; # ft\n",
"D2=0.256; # ft\n",
"aa=((pi)*(D2**2-D1**2)/4); # flow area,ft**2\n",
"print\"\\t flow area is : ft**2 \\t\",aa\n",
"De=(D2**2-D1**2)/D1; # equiv diameter,ft\n",
"print\"\\t equiv diameter is : ft \\t\",De\n",
"Ga=(W/aa); # mass velocity,lb/(hr)*(ft**2)\n",
"print\"\\t mass velocity is : lb/(hr)*(ft**2) \\t\",Ga\n",
"mu1=3*2.42; # at 389.5F,lb/(ft)*(hr), from fig.14\n",
"Rea=((De)*(Ga)/mu1); # reynolds number\n",
"print\"\\t reynolds number is : \\t\",Rea\n",
"jH=20.5; # from fig.24\n",
"c=0.615; # Btu/(lb)*(F),at 130F\n",
"k=0.067; # Btu/(hr)*(ft**2)*(F/ft), from table 4\n",
"Pr=((c)*(mu1)/k)**(1/3); # prandelt number raised to power 1/3\n",
"print\"\\t Pr is : \\t\",Pr\n",
"Ho=((jH)*(k/De)*(Pr)); # H0=(h0/phya),using eq.6.15,Btu/(hr)*(ft**2)*(F)\n",
"print\"\\t individual heat transfer coefficient is : Btu/(hr)*(ft**2)*(F) \\t\",Ho\n",
"print\"\\t cold fluid:inner pipe,crude oil \\t\"\n",
"D=0.172; # ft\n",
"ap=((pi)*(D**2)/4); # flow area, ft**2\n",
"print\"\\t flow area is : ft**2 \\t\",ap\n",
"Gp=(w/(2*ap)); # mass velocity,lb/(hr)*(ft**2)\n",
"print\"\\t mass velocity is : lb/(hr)*(ft**2) \\t\",Gp\n",
"mu2=0.83*2.42; # at 304 F,lb/(ft)*(hr)\n",
"Rep=((D)*(Gp)/mu2); # reynolds number\n",
"print\"\\t reynolds number is : \\t\",Rep\n",
"jH=320; # from fig.24\n",
"c=0.585; # Btu/(lb)*(F),at 304F,from fig.4\n",
"k=0.073; # Btu/(hr)*(ft**2)*(F/ft), from fig.1\n",
"Pr=((c)*(mu2)/k)**(1/3); # prandelt number raised to power 1/3\n",
"print\"\\t Pr is : \\t\",Pr\n",
"Hi=((jH)*(k/D)*(Pr)*(1**0.14)); #Hi=(hi/phyp),using eq.6.15a,Btu/(hr)*(ft**2)*(F)\n",
"print\"\\t Hi is : Btu/(hr)*(ft**2)*(F) \\t\",Hi\n",
"ID=2.067; # ft\n",
"OD=2.38; #ft\n",
"Hio=((Hi)*(ID/OD)); #Hio=(hio/phyp), using eq.6.5\n",
"print\"\\t Correct Hi0 to the surface at the OD is : Btu/(hr)*(ft**2)*(F) \",Hio\n",
"muw=0.77*2.42; # lb/(ft)*(hr), from fig.14\n",
"phyp=(mu2/muw)**0.14;\n",
"print\"\\t phyp is : \\t\",phyp # from fig.24\n",
"hio=(Hio)*(1); # from eq.6.37\n",
"print\"\\t Correct hio to the surface at the OD is : Btu/(hr)*(ft**2)*(F) \",hio\n",
"tw=(tc)+(((Ho)/(Hio+Ho))*(Tc-tc)); # from eq.5.31\n",
"print\"\\t tw is : F \\t\",tw\n",
"muw=6.6*2.42; # lb/(ft)*(hr), from fig.14\n",
"phya=(mu1/muw)**0.14;\n",
"print\"\\t phya is : \\t\",phya # from fig.24\n",
"ho=(Ho)*(phya); # from eq.6.36\n",
"print\"\\t Correct h0 to the surface at the OD is : Btu/(hr)*(ft**2)*(F) \\t\",ho\n",
"Uc=((hio)*(ho)/(hio+ho)); # clean overall coefficient,Btu/(hr)*(ft**2)*(F)\n",
"print\"\\t clean overall coefficient is : Btu/(hr)*(ft**2)*(F) \\t\",Uc\n",
"Rd=0.006; # required by problem,(hr)*(ft**2)*(F)/Btu\n",
"UD=((Uc)/((1)+(Uc*Rd))); # design overall coefficient,Btu/(hr)*(ft**2)*(F)\n",
"print\"\\t design overall coefficient is : Btu/(hr)*(ft**2)*(F) \\t\",UD\n",
"A=((Q)/((UD)*(LMTD))); # required surface,ft**2\n",
"print\"\\t required surface is : ft**2 \\t\",A\n",
"A1=0.622; # From Table 11,ft**2\n",
"Lr=(A/A1); # required length;lin ft\n",
"print\"\\t required length is : lin ft \\t\",Lr\n",
"print\"\\t Since two parallel streams are employed, use eight 20 ft hairpins or 320 lin. feet \\t\"\n",
"L=320;\n",
"A2=320*0.622; # actual surface supplied,ft**2\n",
"print\"\\t actual surface supplied is : ft**2 \\t\",A2\n",
"UD=((Q)/((A2)*(LMTD)));\n",
"print\"\\t actual design overall coefficient is : Btu/(hr)*(ft**2)*(F) \\t\",UD\n",
"Rd=((Uc-UD)/((UD)*(Uc))); # (hr)*(ft**2)*(F)/Btu\n",
"print\"\\t actual Rd is : (hr)*(ft**2)*(F)/Btu \\t\",Rd\n",
"print\"\\t pressure drop for annulus \\t\"\n",
"De1=.058; #ft\n",
"print\"\\t De1 is : ft \\t\",De1\n",
"Rea1=((De1)*(Ga)/7.25); # reynolds number\n",
"print\"\\t reynolds number is : \\t\",Rea1\n",
"f=(0.0035)+((0.264)/(2680**0.42)); # friction factor, using eq.3.47b\n",
"print\"\\t friction factor is : \\t\",f\n",
"s=0.775;\n",
"row=62.5*0.775; # from fig 6\n",
"delFa=((4*f*(Ga**2)*L)/(2*4.18*(10**8)*(row**2)*(De1))); # ft\n",
"print\"\\t delFa is : ft \\t\",delFa\n",
"V=((Ga)/(3600*row)); #fps\n",
"print\"\\t V is : fps \\t\",V\n",
"delFl=((8*(V**2))/(2*32.2)); #ft\n",
"print\"\\t delFl is : ft \\t\",delFl\n",
"delPa=((delFa+delFl)*(row)/144); # psi\n",
"print\"\\t delPa is : psi \\t\",delPa\n",
"print\"\\t allowable delPa is 10 psi \\t\"\n",
"print\"\\t pressure drop for inner pipe \\t\"\n",
"f=(0.0035)+((0.264)/(Rep**0.42)); # friction factor, using eq.3.47b\n",
"print\"\\t friction factor is : \\t\",round(f,7)\n",
"s=0.76;\n",
"row=62.5*0.76; # from table 6\n",
"Lp=160;\n",
"delFp=((4*f*(Gp**2)*Lp)/(2*4.18*(10**8)*(row**2)*(D))); # ft\n",
"print\"\\t delFp is : ft \\t\",round(delFp,1)\n",
"delPp=((delFp)*(row)/144); # psi\n",
"print\"\\t delPp is : psi \\t\",round(delPp,1)\n",
"print\"\\t allowable delPp is 10 psi \\t\"\n",
"# end\n"
]
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