{
"cells": [
{
"cell_type": "markdown",
"metadata": {},
"source": [
"# Chapter 12 Condensation of Single Vapours "
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"## Example 12.1 pgno:274"
]
},
{
"cell_type": "code",
"execution_count": 3,
"metadata": {
"collapsed": false
},
"outputs": [
{
"name": "stdout",
"output_type": "stream",
"text": [
"\t example 12.1 \t\n",
"\t approximate values are mentioned in the book \t\n",
"\t 1.for heat balance \t\n",
"\t for propanol \t\n",
"\t total heat required for propanol is : Btu/hr \t17100000\n",
"\t for water \t\n",
"\t total heat required for water is : Btu/hr \t17080000.0\n",
"\t delt1 is : F \t159.0\n",
"\t delt2 is : F \t124.0\n",
"\t LMTD is : F \t140.93382183\n",
"\t caloric temperature of hot fluid is : F \t244.0\n",
"\t caloric temperature of cold fluid is : F \t102.5\n",
"\t A1 is : ft**2 \t1199.91715754\n",
"\t number of tubes are : \t764.083773266\n",
"\t total surface area is : ft**2 \t1202.9264\n",
"\t correct design overall coefficient is : Btu/(hr)*(ft**2)*(F) \t100.74733825\n",
"\t hot fluid:shell side,propanol \t\n",
"\t flow area is : ft**2 \t1.33543445393\n",
"\t mass velocity is : lb/(hr)*(ft**2) \t44929.1987513\n",
"\t G1 is : %.1f lb/(hr)*(lin ft) \t7500\n",
"\t cold fluid:inner tube side,water \t\n",
"\t flow area is : ft**2 \t0.401618055556\n",
"\t mass velocity is : lb/(hr)*(ft**2) \t1215084.81317\n",
"\t V is : fps \t5.40037694742\n",
"\t reynolds number is : \t36103.3820924\n",
"\t hi is : Btu/(hr)*(ft**2)*(F) \t1300\n",
"\t Correct hi0 to the surface at the OD is : Btu/(hr)*(ft**2)*(F) \t1074.66666667\n",
"\t tw is : F \t124.701882845\n",
"\t tf is : F \t184.350941423\n",
"\t Correct ho to the surface at the OD is : Btu/(hr)*(ft**2)*(F) \t172\n",
"\t Based on h=172 instead of the assumed 200 a new value of tw,and tf could be obtained to give a more exact value of h based on fluid properties at a value of tf more nearly correct \t\n",
"\t pressure drop for annulus \t\n",
"\t reynolds number is : \t85031.2935045\n",
"\t number of crosses are : \t3\n",
"\t delPs is : psi \t0.937425488924\n",
"\t allowable delPa is 2 psi \t\n",
"\t pressure drop for inner pipe \t\n",
"\t delPt is : psi \t3.32625636683\n",
"\t delPr is : psi \t3.2\n",
"\t delPT is : psi \t6.5\n",
"\t allowable delPT is 10 psi \t\n",
"\t clean overall coefficient is : Btu/(hr)*(ft**2)*(F) \t148.3\n",
"\t actual Rd is : (hr)*(ft**2)*(F)/Btu \t0.003\n"
]
}
],
"source": [
"print\"\\t example 12.1 \\t\"\n",
"print\"\\t approximate values are mentioned in the book \\t\"\n",
"T1=244.;# inlet hot fluid,F\n",
"T2=244.; # outlet hot fluid,F\n",
"t1=85.; # inlet cold fluid,F\n",
"t2=120.; # outlet cold fluid,F\n",
"W=60000; # lb/hr\n",
"w=488000; # lb/hr\n",
"from math import log10\n",
"print\"\\t 1.for heat balance \\t\"\n",
"print\"\\t for propanol \\t\"\n",
"l=285; # Btu/(lb)\n",
"Q=((W)*(l)); # Btu/hr\n",
"print\"\\t total heat required for propanol is : Btu/hr \\t\",Q\n",
"print\"\\t for water \\t\"\n",
"c=1; # Btu/(lb)*(F)\n",
"Q=((w)*(c)*(t2-t1)); # Btu/hr\n",
"print\"\\t total heat required for water is : Btu/hr \\t\",Q\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)/((2.3)*(log10(delt2/delt1))));\n",
"print\"\\t LMTD is : F \\t\",LMTD\n",
"Tc=((T2)+(T1))/(2); # caloric temperature of hot fluid,F\n",
"print\"\\t caloric temperature of hot fluid is : F \\t\",Tc\n",
"tc=((t1)+(t2))/(2); # caloric temperature of cold fluid,F\n",
"print\"\\t caloric temperature of cold fluid is : F \\t\",tc\n",
"UD1=101; # assume, from table 8\n",
"A1=((Q)/((UD1)*(LMTD)));\n",
"print\"\\t A1 is : ft**2 \\t\",A1\n",
"a1=0.1963; # ft**2/lin ft\n",
"N1=(A1/(8*a1));\n",
"print\"\\t number of tubes are : \\t\",N1\n",
"N2=766; # assuming 4 tube passes, from table 9\n",
"A2=(N2*8*a1); # ft**2\n",
"print\"\\t total surface area is : ft**2 \\t\",A2\n",
"UD=((Q)/((A2)*(LMTD)));\n",
"print\"\\t correct design overall coefficient is : Btu/(hr)*(ft**2)*(F) \\t\",UD\n",
"print\"\\t hot fluid:shell side,propanol \\t\"\n",
"ID=31; # in\n",
"C=0.1875; # clearance\n",
"B=31; # baffle spacing,in\n",
"PT=0.937;\n",
"L=8; # ft\n",
"As=((ID*C*B)/(144*PT)); # flow area,from eq 7.1,ft**2\n",
"print\"\\t flow area is : ft**2 \\t\",As\n",
"Gs=(W/As); # mass velocity,from eq 7.2,lb/(hr)*(ft**2)\n",
"print\"\\t mass velocity is : lb/(hr)*(ft**2) \\t\",Gs\n",
"G1=(W/(L*N2**(2/3)))# from eq.12.43\n",
"print\"\\t G1 is : %.1f lb/(hr)*(lin ft) \\t\",G1\n",
"print\"\\t cold fluid:inner tube side,water \\t\"\n",
"Nt=766;\n",
"n=4; # number of passes\n",
"L=8; #ft\n",
"at1=0.302; # flow area, in**2\n",
"at=((Nt*at1)/(144*n)); # total area,ft**2,from eq.7.48\n",
"print\"\\t flow area is : ft**2 \\t\",at\n",
"Gt=(w/(at)); # mass velocity,lb/(hr)*(ft**2)\n",
"print\"\\t mass velocity is : lb/(hr)*(ft**2) \\t\",Gt\n",
"V=(Gt/(3600*62.5));\n",
"print\"\\t V is : fps \\t\",V\n",
"mu2=1.74; # at 102.5F,lb/(ft)*(hr)\n",
"D=0.0517; # ft\n",
"Ret=((D)*(Gt)/mu2); # reynolds number\n",
"print\"\\t reynolds number is : \\t\",Ret\n",
"hi=1300; #Btu/(hr)*(ft**2)*(F)\n",
"print\"\\t hi is : Btu/(hr)*(ft**2)*(F) \\t\",hi\n",
"ID=0.62; # ft\n",
"OD=0.75; #ft\n",
"hio=((hi)*(ID/OD)); # using eq.6.5\n",
"print\"\\t Correct hi0 to the surface at the OD is : Btu/(hr)*(ft**2)*(F) \\t\",hio # calculation mistake\n",
"ho=200; # assumption\n",
"tw=(tc)+(((ho)/(hio+ho))*(Tc-tc)); # from eq.5.31\n",
"print\"\\t tw is : F \\t\",tw\n",
"tf=(Tc+tw)/(2); # from eq 12.19\n",
"print\"\\t tf is : F \\t\",tf\n",
"kf=0.094; # Btu/(hr)*(ft**2)*(F/ft), from table 4\n",
"sf=0.8; # from table 6\n",
"muf=0.62; # cp, from fig 14\n",
"ho=172; # Btu/(hr)*(ft**2)*(F), from fig 12.9\n",
"print\"\\t Correct ho to the surface at the OD is : Btu/(hr)*(ft**2)*(F) \\t\",ho\n",
"print\"\\t Based on h=172 instead of the assumed 200 a new value of tw,and tf could be obtained to give a more exact value of h based on fluid properties at a value of tf more nearly correct \\t\"\n",
"print\"\\t pressure drop for annulus \\t\"\n",
"mu1=0.0242; # lb/(ft)*(hr), fir 15\n",
"De=0.0458; # fig 28\n",
"Res=((De)*(Gs)/mu1); # reynolds number\n",
"print\"\\t reynolds number is : \\t\",Res\n",
"f=0.00141; # friction factor for reynolds number 84600, using fig.29\n",
"s=0.00381; # for reynolds number 84600,using fig.6\n",
"Ds=31/12; # ft\n",
"phys=1;\n",
"N=(3); # number of crosses,using eq.7.43\n",
"print\"\\t number of crosses are : \\t\",N\n",
"delPs=((f*(Gs**2)*(Ds)*(N))/(5.22*(10**10)*(De)*(s)*(phys)))/(2); # using eq.12.47,psi\n",
"print\"\\t delPs is : psi \\t\",delPs\n",
"print\"\\t allowable delPa is 2 psi \\t\"\n",
"print\"\\t pressure drop for inner pipe \\t\"\n",
"f=0.00019; # friction factor for reynolds number 36200, using fig.26\n",
"s=1;\n",
"phyt=1;\n",
"delPt=((f*(Gt**2)*(L)*(n))/(5.22*(10**10)*(D)*(s)*(phyt))); # using eq.7.45,psi\n",
"print\"\\t delPt is : psi \\t\",round(delPt,1)\n",
"X1=0.2; # X1=((V**2)/(2*g)),using fig.27\n",
"delPr=((4*n*X1)/(s)); # using eq.7.46,psi\n",
"print\"\\t delPr is : psi \\t\",delPr\n",
"delPT=delPt+delPr; # using eq.7.47,psi\n",
"print\"\\t delPT is : psi \\t\",round(delPT,1)\n",
"print\"\\t allowable delPT is 10 psi \\t\"\n",
"Uc=((hio)*(ho)/(hio+ho)); # clean overalcoefficient,Btu/(hr)*(ft**2)*(F)\n",
"print\"\\t clean overall coefficient is : Btu/(hr)*(ft**2)*(F) \\t\",round(Uc,1)\n",
"Rd=((Uc-UD)/((UD)*(Uc))); # (hr)*(ft**2)*(F)/Btu\n",
"print\"\\t actual Rd is : (hr)*(ft**2)*(F)/Btu \\t\",round(Rd,3)\n",
"# end\n"
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"## Example 12.2 pgno:277"
]
},
{
"cell_type": "code",
"execution_count": 6,
"metadata": {
"collapsed": false
},
"outputs": [
{
"name": "stdout",
"output_type": "stream",
"text": [
"\t example 12.2 \t\n",
"\t approximate values are mentioned in the book \t\n",
"\t 1.for heat balance \t\n",
"\t for propanol \t\n",
"\t total heat required for propanol is : Btu/hr \t17100000\n",
"\t for water \t\n",
"\t total heat required for water is : Btu/hr \t17080000.0\n",
"\t delt1 is : F \t159.0\n",
"\t delt2 is : F \t124.0\n",
"\t LMTD is f F \t140.93382183\n",
"\t caloric temperature of hot fluid is : F \t244.0\n",
"\t caloric temperature of cold fluid is : F \t102.5\n",
"\t A1 is : ft**2 \t1731.30904159\n",
"\t L is : ft \t11.5139815143\n",
"\t total surface area is : ft**2 \t1804.3896\n",
"\t correct design overall coefficient is : Btu/(hr)*(ft**2)*(F) \t67.164892167\n",
"\t hot fluid:shell side,propanol \t\n",
"\t G1 is : lb/(hr)*(lin ft) \t399.12856929\n",
"\t cold fluid:inner tube side,water \t\n",
"\t flow area is : ft**2 \t0.401618055556\n",
"\t mass velocity is : lb/(hr)*(ft**2) \t1215084.81317\n",
"\t V is : fps \t5.40037694742\n",
"\t reynolds number is : \t36103.3820924\n",
"\t hi is : Btu/(hr)*(ft**2)*(F) \t1300\n",
"\t Correct hi0 to the surface at the OD is : Btu/(hr)*(ft**2)*(F) \t1074.66666667\n",
"\t tw is : F \t114.545970488\n",
"\t tf is : F \t179.272985244\n",
"\t Correct ho to the surface at the OD is : Btu/(hr)*(ft**2)*(F) \t102\n",
"\t pressure drop for annulus \t\n",
"\t flow area is : ft**2 \t1.24927739239\n",
"\t mass velocity is : lb/(hr)*(ft**2) \t48027.7641824\n",
"\t reynolds number is : \t90895.5206428\n",
"\t number of crosses are : \t5\n",
"\t delPs is : psi \t1.7726452141\n",
"\t allowable delPa is 2 psi \t\n",
"\t pressure drop for inner pipe \t\n",
"\t delPt is : psi \t5.0\n",
"\t delPr is : psi \t3.2\n",
"\t delPT is : psi \t8.2\n",
"\t allowable delPT is 10 psi \t\n",
"\t clean overall coefficient is : Btu/(hr)*(ft**2)*(F) \t93.2\n",
"\t actual Rd is : (hr)*(ft**2)*(F)/Btu \t0.004\n"
]
}
],
"source": [
"print\"\\t example 12.2 \\t\"\n",
"print\"\\t approximate values are mentioned in the book \\t\"\n",
"T1=244.; # inlet hot fluid,F\n",
"T2=244.; # outlet hot fluid,F\n",
"t1=85.; # inlet cold fluid,F\n",
"t2=120.; # outlet cold fluid,F\n",
"W=60000; # lb/hr\n",
"w=488000; # lb/hr\n",
"from math import log10\n",
"print\"\\t 1.for heat balance \\t\"\n",
"print\"\\t for propanol \\t\"\n",
"l=285; # Btu/(lb)\n",
"Q=((W)*(l)); # Btu/hr\n",
"print\"\\t total heat required for propanol is : Btu/hr \\t\",Q\n",
"print\"\\t for water \\t\"\n",
"c=1; # Btu/(lb)*(F)\n",
"Q=((w)*(c)*(t2-t1)); # Btu/hr\n",
"print\"\\t total heat required for water is : Btu/hr \\t\",Q\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)/((2.3)*(log10(delt2/delt1))));\n",
"print\"\\t LMTD is f F \\t\",LMTD\n",
"Tc=((T2)+(T1))/(2); # caloric temperature of hot fluid,F\n",
"print\"\\t caloric temperature of hot fluid is : F \\t\",Tc\n",
"tc=((t1)+(t2))/(2); # caloric temperature of cold fluid,F\n",
"print\"\\t caloric temperature of cold fluid is : F \\t\",tc\n",
"UD1=70; # assume, from table 8\n",
"A1=((Q)/((UD1)*(LMTD)));\n",
"print\"\\t A1 is : ft**2 \\t\",A1\n",
"N2=766; # assuming 4 tube passes, from table 9\n",
"a1=0.1963; # ft**2/lin ft\n",
"L=(A1/(N2*a1));\n",
"print\"\\t L is : ft \\t\",L\n",
"A2=(N2*12*a1); # ft**2\n",
"print\"\\t total surface area is : ft**2 \\t\",A2\n",
"UD=((Q)/((A2)*(LMTD)));\n",
"print\"\\t correct design overall coefficient is : Btu/(hr)*(ft**2)*(F) \\t\",UD\n",
"print\"\\t hot fluid:shell side,propanol \\t\"\n",
"Do=0.0625; # ft\n",
"G1=(W/(3.14*N2*Do)); # from eq.12.36\n",
"print\"\\t G1 is : lb/(hr)*(lin ft) \\t\",G1\n",
"print\"\\t cold fluid:inner tube side,water \\t\"\n",
"Nt=766;\n",
"n=4; # number of passes\n",
"L=12; #ft\n",
"at1=0.302; # flow area, in**2\n",
"at=((Nt*at1)/(144*n)); # total area,ft**2,from eq.7.48\n",
"print\"\\t flow area is : ft**2 \\t\",at\n",
"Gt=(w/(at)); # mass velocity,lb/(hr)*(ft**2)\n",
"print\"\\t mass velocity is : lb/(hr)*(ft**2) \\t\",Gt\n",
"V=(Gt/(3600*62.5));\n",
"print\"\\t V is : fps \\t\",V\n",
"mu2=1.74; # at 102.5F,lb/(ft)*(hr)\n",
"D=0.0517; # ft\n",
"Ret=((D)*(Gt)/mu2); # reynolds number\n",
"print\"\\t reynolds number is : \\t\",Ret\n",
"hi=1300; #Btu/(hr)*(ft**2)*(F)\n",
"print\"\\t hi is : Btu/(hr)*(ft**2)*(F) \\t\",hi\n",
"ID=0.62; # ft\n",
"OD=0.75; #ft\n",
"hio=((hi)*(ID/OD)); # using eq.6.5\n",
"print\"\\t Correct hi0 to the surface at the OD is : Btu/(hr)*(ft**2)*(F) \\t\",hio\n",
"ho=100; # assumption\n",
"tw=(tc)+(((ho)/(hio+ho))*(Tc-tc)); # from eq.5.31\n",
"print\"\\t tw is : F \\t\",tw\n",
"tf=(Tc+tw)/(2); # from eq 12.19\n",
"print\"\\t tf is : F \\t\",tf\n",
"kf=0.0945; # Btu/(hr)*(ft**2)*(F/ft), from table 4\n",
"sf=0.76; # from table 6\n",
"muf=0.65; # cp, from fig 14\n",
"ho=102; # Btu/(hr)*(ft**2)*(F), from fig 12.9\n",
"print\"\\t Correct ho to the surface at the OD is : Btu/(hr)*(ft**2)*(F) \\t\",ho\n",
"print\"\\t pressure drop for annulus \\t\"\n",
"ID=31; # in\n",
"C=0.1875; # clearance\n",
"B=29; # baffle spacing,in\n",
"PT=0.937;\n",
"As=((ID*C*B)/(144*PT)); # flow area,from eq 7.1,ft**2\n",
"print\"\\t flow area is : ft**2 \\t\",As\n",
"Gs=(W/As); # mass velocity,from eq 7.2,lb/(hr)*(ft**2)\n",
"print\"\\t mass velocity is : lb/(hr)*(ft**2) \\t\",Gs\n",
"mu1=0.0242; # lb/(ft)*(hr), fig 15\n",
"De=0.0458; # fig 28\n",
"Res=((De)*(Gs)/mu1); # reynolds number\n",
"print\"\\t reynolds number is : \\t\",Res\n",
"f=0.0014; # friction factor for reynolds number 91000, using fig.29\n",
"s=0.00381; # for reynolds number 91000,using fig.6\n",
"Ds=31/12; # ft\n",
"phys=1;\n",
"N=(5); # number of crosses,using eq.7.43\n",
"print\"\\t number of crosses are : \\t\",N\n",
"delPs=((f*(Gs**2)*(Ds)*(N))/(5.22*(10**10)*(De)*(s)*(phys)))/(2); # using eq.12.47,psi\n",
"print\"\\t delPs is : psi \\t\",delPs\n",
"print\"\\t allowable delPa is 2 psi \\t\"\n",
"print\"\\t pressure drop for inner pipe \\t\"\n",
"f=0.00019; # friction factor for reynolds number 36200, using fig.26\n",
"s=1;\n",
"phyt=1;\n",
"delPt=((f*(Gt**2)*(L)*(n))/(5.22*(10**10)*(D)*(s)*(phyt))); # using eq.7.45,psi\n",
"print\"\\t delPt is : psi \\t\",round(delPt,1)\n",
"X1=0.2; # X1=((V**2)/(2*g)),using fig.27\n",
"delPr=((4*n*X1)/(s)); # using eq.7.46,psi\n",
"print\"\\t delPr is : psi \\t\",delPr\n",
"delPT=delPt+delPr; # using eq.7.47,psi\n",
"print\"\\t delPT is : psi \\t\",round(delPT,1)\n",
"print\"\\t allowable delPT is 10 psi \\t\"\n",
"Uc=((hio)*(ho)/(hio+ho)); # clean overall coefficient,eq 6.38,Btu/(hr)*(ft**2)*(F)\n",
"print\"\\t clean overall coefficient is : Btu/(hr)*(ft**2)*(F) \\t\",round(Uc,1)\n",
"Rd=((Uc-UD)/((UD)*(Uc))); # eq 6.13,(hr)*(ft**2)*(F)/Btu\n",
"print\"\\t actual Rd is : (hr)*(ft**2)*(F)/Btu \\t\",round(Rd,3)\n",
"# end\n"
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"## Example 12.3 pgno:285"
]
},
{
"cell_type": "code",
"execution_count": 10,
"metadata": {
"collapsed": false
},
"outputs": [
{
"name": "stdout",
"output_type": "stream",
"text": [
"\t example 12.3 \t\n",
"\t approximate values are mentioned in the book \t\n",
"\t 1.for heat balance \t\n",
"\t for butane \t\n",
"\t total heat required for desuperheating of butane is : Btu/hr \t861106.4\n",
"\t total heat required for condensing of butane is : Btu/hr \t3886162\n",
"\t total heat required for butane is : Btu/hr \t4747268.4\n",
"\t for water \t\n",
"\t total heat required for water is : Btu/hr \t4742500.0\n",
"\t deltw is : F \t28\n",
"\t t2 is : F \t93.0\n",
"\t for desuperheating \t\n",
"\t delt1 is : F \t37.0\n",
"\t delt2 is : F \t100.0\n",
"\t LMTD is : F \t63.4354185149\n",
"\t w1 is : lb/hr \t13574.5364366\n",
"\t for condensing \t\n",
"\t delt1 is : F \t60.0\n",
"\t delt2 is : F \t37.0\n",
"\t LMTD is : F \t47.6304956503\n",
"\t w1 is : lb/hr \t81589.787109\n",
"\t delt is : F \t49.8348522147\n",
"\t caloric temperature of hot fluid is : F \t127.5\n",
"\t caloric temperature of cold fluid is : F \t82.5\n",
"\t hot fluid:shell side,butane \t\n",
"\t flow area is :f ft**2 \t0.484375\n",
"\t desuperheating \t\n",
"\t mass velocity is : lb/(hr)*(ft**2) \t57719.7419355\n",
"\t reynolds number is : \t145094.392606\n",
"\t individual heat transfer coefficient is : Btu/(hr)*(ft**2)*(F) \t45.2593972603\n",
"\t cold fluid:inner tube side,water \t\n",
"\t flow area is : ft**2 \t0.184555555556\n",
"\t mass velocity is : lb/(hr)*(ft**2) \t734196.267309\n",
"\t V is : fps \t3.26309452137\n",
"\t reynolds number is : \t17989.5483506\n",
"\t hi is : Btu/(hr)*(ft**2)*(F) \t800\n",
"\t Correct hio to the surface at the OD is : Btu/(hr)*(ft**2)*(F) \t661.333333333\n",
"\t clean overall coefficient is : Btu/(hr)*(ft**2)*(F) \t42.3603962493\n",
"\t clean surface required for desuperheating : ft**2 \t320.453481046\n",
"\t for condensaton \t\n",
"\t G1 is : lb/(hr)*(lin ft) \t2912.29166667\n",
"\t tw is : F \t92.9489164087\n",
"\t tf is : F \t110.224458204\n",
"\t Correct ho to the surface at the OD is : Btu/(hr)*(ft**2)*(F) \t207\n",
"\t clean overall coefficient is : Btu/(hr)*(ft**2)*(F) \t157.653742802\n",
"\t clean surface required for desuperheating : ft**2 \t517.525214808\n",
"\t total clean surface : ft**2 \t837.978695854\n",
"\t assumed condensing length percentage : \t0.617587556066\n",
"\t weighted clean overall coefficient : Btu/(hr)*(ft**2)*(F) \t113.564132378\n",
"\t total surface area is : ft**2 \t1105.5616\n",
"\t actual design overall coefficient is : Btu/(hr)*(ft**2)*(F) \t86.0778119876\n",
"\t actual Rd is : (hr)*(ft**2)*(F)/Btu \t0.003\n",
"\t pressure drop for annulus \t\n",
"\t desuperheating \t\n",
"\t number of crosses are : \t6.4\n",
"\t row is lb/ft**3 \t1.09763894416\n",
"\t s is \t0.0175622231065\n",
"\t delPs is : psi \t0.964762124732\n",
"\t condensation \t\n",
"\t number of crosses are : \t9.6\n",
"\t delPsc is : psi \t0.723571593549\n",
"\t delPS is : psi \t1.68833371828\n",
"\t allowable delPa is 2 psi \t\n",
"\t pressure drop for inner pipe \t\n",
"\t delPt is : psi \t3.0\n",
"\t delPr is : psi \t1.2\n",
"\t delPT is : psi \t4.1\n",
"\t allowable delPa is 10 psi \t\n"
]
}
],
"source": [
"print\"\\t example 12.3 \\t\"\n",
"print\"\\t approximate values are mentioned in the book \\t\"\n",
"T1=200.; # inlet hot fluid,F\n",
"T2=130.; # outlet hot fluid,F\n",
"T3=125.; # after condensation\n",
"t1=65.; # inlet cold fluid,F\n",
"t3=100.; # outlet cold fluid,F\n",
"W=27958; # lb/hr\n",
"w=135500; # lb/hr\n",
"from math import log10\n",
"print\"\\t 1.for heat balance \\t\"\n",
"print\"\\t for butane \\t\"\n",
"c=0.44; # Btu/(lb)(F)\n",
"qd=((W)*(c)*(T1-T2)); # Btu/hr\n",
"print\"\\t total heat required for desuperheating of butane is : Btu/hr \\t\",qd\n",
"HT2=309; # enthalpy at T2, Btu/lb\n",
"HT3=170; # enthalpy at T3, Btu/lb\n",
"qc=(W*(HT2-HT3)); # for condensation\n",
"print\"\\t total heat required for condensing of butane is : Btu/hr \\t\",qc\n",
"Q=qd+qc;\n",
"print\"\\t total heat required for butane is : Btu/hr \\t\",Q\n",
"print\"\\t for water \\t\"\n",
"c=1; # Btu/(lb)*(F)\n",
"Q=((w)*(c)*(t3-t1)); # Btu/hr\n",
"print\"\\t total heat required for water is : Btu/hr \\t\",Q\n",
"deltw=(qc/w);\n",
"print\"\\t deltw is : F \\t\",deltw\n",
"t2=t1+deltw;\n",
"print\"\\t t2 is : F \\t\",t2\n",
"print\"\\t for desuperheating \\t\"\n",
"delt1=T2-t2; #F\n",
"delt2=T1-t3; # F\n",
"print\"\\t delt1 is : F \\t\",delt1\n",
"print\"\\t delt2 is : F \\t\",delt2\n",
"LMTDd=((delt2-delt1)/((2.3)*(log10(delt2/delt1))));\n",
"print\"\\t LMTD is : F \\t\",LMTDd\n",
"w1=(qd/LMTDd);\n",
"print\"\\t w1 is : lb/hr \\t\",w1\n",
"print\"\\t for condensing \\t\"\n",
"delt3=T3-t1; #F\n",
"delt4=T2-t2; # F\n",
"print\"\\t delt1 is : F \\t\",delt3\n",
"print\"\\t delt2 is : F \\t\",delt4\n",
"LMTDc=((delt4-delt3)/((2.3)*(log10(delt4/delt3))));\n",
"print\"\\t LMTD is : F \\t\",LMTDc\n",
"w2=(qc/LMTDc);\n",
"print\"\\t w1 is : lb/hr \\t\",w2\n",
"delt=(Q/(w1+w2));\n",
"print\"\\t delt is : F \\t\",delt\n",
"Tc=((T3)+(T2))/(2); # caloric temperature of hot fluid,F\n",
"print\"\\t caloric temperature of hot fluid is : F \\t\",Tc\n",
"tc=((t1)+(t3))/(2); # caloric temperature of cold fluid,F\n",
"print\"\\t caloric temperature of cold fluid is : F \\t\",tc\n",
"print\"\\t hot fluid:shell side,butane \\t\"\n",
"ID=23.25; # in\n",
"C=0.25; # clearance\n",
"B=12; # baffle spacing,in\n",
"PT=1;\n",
"As=((ID*C*B)/(144*PT)); # flow area,ft**2\n",
"print\"\\t flow area is :f ft**2 \\t\",As\n",
"print\"\\t desuperheating \\t\"\n",
"Gs=(W/As); # mass velocity,lb/(hr)*(ft**2)\n",
"print\"\\t mass velocity is : lb/(hr)*(ft**2) \\t\",Gs\n",
"mu1=0.0242; # at 165F,lb/(ft)*(hr), from fig.15\n",
"De=0.73/12; # from fig.28,ft\n",
"Res=((De)*(Gs)/mu1); # reynolds number\n",
"print\"\\t reynolds number is : \\t\",Res\n",
"jH=239; # from fig.28\n",
"k=0.012; # Btu/(hr)*(ft**2)*(F/ft), from table 5\n",
"Z=0.96; # Z=((c)*(mu1)/k)**(1/3)\n",
"ho=((jH)*(k/De)*(Z)); # H0=(h0/phya),using eq.6.15b,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 tube side,water \\t\"\n",
"Nt=352;\n",
"n=4; # number of passes\n",
"L=16; #ft\n",
"at1=0.302; # flow area,table 10, in**2\n",
"at=((Nt*at1)/(144*n)); # total area,ft**2,from eq.7.48\n",
"print\"\\t flow area is : ft**2 \\t\",at\n",
"Gt=(w/(at)); # mass velocity,lb/(hr)*(ft**2)\n",
"print\"\\t mass velocity is : lb/(hr)*(ft**2) \\t\",Gt\n",
"V=(Gt/(3600*62.5));\n",
"print\"\\t V is : fps \\t\",V\n",
"mu2=2.11; # at 82.5F, fig 14,lb/(ft)*(hr)\n",
"D=0.0517; # ft\n",
"Ret=((D)*(Gt)/mu2); # reynolds number\n",
"print\"\\t reynolds number is : \\t\",Ret\n",
"hi=800; # fig 25,Btu/(hr)*(ft**2)*(F)\n",
"print\"\\t hi is : Btu/(hr)*(ft**2)*(F) \\t\",hi\n",
"ID=0.62; # ft\n",
"OD=0.75; #ft\n",
"hio=((hi)*(ID/OD)); # using eq.6.5\n",
"print\"\\t Correct hio to the surface at the OD is : Btu/(hr)*(ft**2)*(F) \\t\",hio\n",
"Ud=((hio)*(ho)/(hio+ho)); # clean overall coefficient,eq 6.38,Btu/(hr)*(ft**2)*(F)\n",
"print\"\\t clean overall coefficient is : Btu/(hr)*(ft**2)*(F) \\t\",Ud\n",
"Ad=(qd/(Ud*LMTDd));\n",
"print\"\\t clean surface required for desuperheating : ft**2 \\t\",Ad\n",
"print\"\\t for condensaton \\t\"\n",
"Lc=16*0.6; # condensation occurs 60 of the tube length\n",
"G1=(W/(Lc*Nt**(2/3))); # from eq.12.43\n",
"print\"\\t G1 is : lb/(hr)*(lin ft) \\t\",G1\n",
"ho=200; # assumption\n",
"tw=(tc)+(((ho)/(hio+ho))*(Tc-tc)); # from eq.5.31\n",
"print\"\\t tw is : F \\t\",tw\n",
"tf=(Tc+tw)/(2); # from eq 12.19\n",
"print\"\\t tf is : F \\t\",tf\n",
"kf=0.075; # Btu/(hr)*(ft**2)*(F/ft)\n",
"sf=0.55; # from table 6\n",
"muf=0.14; # cp, from fig 14\n",
"ho=207; # Btu/(hr)*(ft**2)*(F), from fig 12.9\n",
"print\"\\t Correct ho 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",
"Ac=(qc/(Uc*LMTDc));\n",
"print\"\\t clean surface required for desuperheating : ft**2 \\t\",Ac\n",
"AC=Ad+Ac;\n",
"print\"\\t total clean surface : ft**2 \\t\",AC\n",
"lc=(Ac/(Ac+Ad));\n",
"print\"\\t assumed condensing length percentage : \\t\",lc\n",
"UC=((Ud*Ad)+(Uc*Ac))/(AC);\n",
"print\"\\t weighted clean overall coefficient : Btu/(hr)*(ft**2)*(F) \\t\",UC\n",
"A2=0.1963; # actual surface supplied for each tube,ft**2,from table 10\n",
"A=(Nt*L*A2); # ft**2\n",
"print\"\\t total surface area is : ft**2 \\t\",A\n",
"UD=((Q)/((A)*(delt)));\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\",round(Rd,3)\n",
"print\"\\t pressure drop for annulus \\t\"\n",
"print\"\\t desuperheating \\t\"\n",
"Ld=6.4; #ft\n",
"De=0.0608; # fig 28\n",
"f=0.0013; # friction factor for reynolds number 145000, using fig.29\n",
"Ds=1.94; # ft\n",
"phys=1;\n",
"N=(12*Ld/B); # number of crosses,using eq.7.43\n",
"print\"\\t number of crosses are : \\t\",N\n",
"row=(58.1/((359)*(625/492)*(14.7/99.7)));\n",
"print\"\\t row is lb/ft**3 \\t\",row\n",
"s=(row/62.5);\n",
"print\"\\t s is \\t\",s\n",
"delPsd=((f*(Gs**2)*(Ds)*(N))/(5.22*(10**10)*(De)*(s)*(phys))); # using eq.7.44,psi\n",
"print\"\\t delPs is : psi \\t\",delPsd\n",
"print\"\\t condensation \\t\"\n",
"N=(12*Lc/B); # number of crosses,using eq.7.43\n",
"print\"\\t number of crosses are : \\t\",N\n",
"delPsc=((f*(Gs**2)*(Ds)*(N))/(5.22*(10**10)*(De)*(s)*(phys)))/(2); # using eq 12.47,psi\n",
"print\"\\t delPsc is : psi \\t\",delPsc\n",
"delPS=delPsd+delPsc;\n",
"print\"\\t delPS is : psi \\t\",delPS\n",
"print\"\\t allowable delPa is 2 psi \\t\"\n",
"print\"\\t pressure drop for inner pipe \\t\"\n",
"f=0.00023; # friction factor for reynolds number 17900, using fig.26\n",
"s=1;\n",
"phyt=1;\n",
"delPt=((f*(Gt**2)*(L)*(n))/(5.22*(10**10)*(D)*(s)*(phyt))); # using eq.7.45,psi\n",
"print\"\\t delPt is : psi \\t\",round(delPt)\n",
"X1=0.075; # X1=((V**2)/(2*g)),using fig.27\n",
"delPr=((4*n*X1)/(s)); # using eq.7.46,psi\n",
"print\"\\t delPr is : psi \\t\",delPr\n",
"delPT=delPt+delPr; # using eq.7.47,psi\n",
"print\"\\t delPT is : psi \\t\",round(delPT,1)\n",
"print\"\\t allowable delPa is 10 psi \\t\"\n",
"#end\n"
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"## Example 12.4 pgno:290"
]
},
{
"cell_type": "code",
"execution_count": 1,
"metadata": {
"collapsed": false
},
"outputs": [
{
"name": "stdout",
"output_type": "stream",
"text": [
"\t example 12.4 \t\n",
"\t approximate values are mentioned in the book \t\n",
"\t 1.for heat balance \t\n",
"\t for pentane \t\n",
"\t total heat required for condensing of pentane is : Btu/hr \t3045000\n",
"\t total heat required for subcooling of pentane is : Btu/hr \t299250.0\n",
"\t total heat required for pentane is : Btu/hr \t3344250.0\n",
"\t for water \t\n",
"\t total heat required for water is : Btu/hr \t3340000.0\n",
"\t deltw is : F \t18\n",
"\t t2 is : F \t82.0\n",
"\t for condensing \t\n",
"\t delt1 is : F \t43.0\n",
"\t delt2 is : F \t30.0\n",
"\t LMTD is : F \t36.1514237668\n",
"\t w1 is : lb/hr \t84229.0477863\n",
"\t subcooling \t\n",
"\t delt1 is : F \t20.0\n",
"\t delt2 is : F \t43.0\n",
"\t LMTD is f F \t30.0807554052\n",
"\t w1 is : lb/hr \t9948.22091297\n",
"\t delt is : F \t35.465033613\n",
"\t caloric temperature of hot fluid is : F \t127.5\n",
"\t caloric temperature of cold fluid is : F \t90.0\n",
"\t hot fluid:shell side,pentane \t\n",
"\t for condensaton \t\n",
"\t G1 is : lb/(hr)*(lin ft) \t289.206403856\n",
"\t cold fluid:inner tube side,water \t\n",
"\t flow area is : ft**2 \t0.193993055556\n",
"\t mass velocity is : lb/(hr)*(ft**2) \t860855.557544\n",
"\t V is : fps \t3.8260247002\n",
"\t reynolds number is : %.2e \t22477.8951137\n",
"\t hi is : Btu/(hr)*(ft**2)*(F) \t940\n",
"\t Correct hio to the surface at the OD is : Btu/(hr)*(ft**2)*(F) \t777.066666667\n",
"\t tw is : F \t95.1964008573\n",
"\t tf is : F \t111.348200429\n",
"\t Correct ho to the surface at the OD is : Btu/(hr)*(ft**2)*(F) \t120\n",
"\t clean overall coefficient is : Btu/(hr)*(ft**2)*(F) \t103.947681332\n",
"\t clean surface required for dcondensation : ft**2 \t803.043110735\n",
"\t subcooling \t\n",
"\t flow area is : ft**2 \t0.520833333333\n",
"\t mass velocity is : lb/(hr)*(ft**2) \t40320.0\n",
"\t reynolds number is : \t6939.13043478\n",
"\t individual heat transfer coefficient is : Btu/(hr)*(ft**2)*(F) \t68.2933263158\n",
"\t clean overall coefficient is : Btu/(hr)*(ft**2)*(F) \t62.7761756841\n",
"\t clean surface required for desuperheating : ft**2 \t158.471279981\n",
"\t total clean surface : ft**2 \t961.514390716\n",
"\t weighted clean overall coefficient : Btu/(hr)*(ft**2)*(F) \t97.1620302154\n",
"\t total surface area is : ft**2 \t1162.096\n",
"\t actual design overall coefficient is : Btu/(hr)*(ft**2)*(F) \t81.0408681377\n",
"\t actual Rd is : (hr)*(ft**2)*(F)/Btu \t0.00204736690467\n",
"\t pressure drop for annulus \t\n",
"\t condensation \t\n",
"\t reynolds number is \t193536.0\n",
"\t rowvapour is ld/ft**3 \t0.342030962803\n",
"\t s is \t0.00547249540485\n",
"\t number of crosses are : \t14.4\n",
"\t delPsc is : psi \t1.29132938612\n",
"\t delPss is negligible \t\n",
"\t allowable delPa is 2 psi \t\n",
"\t pressure drop for inner pipe \t\n",
"\t delPt is : psi \t3.9\n",
"\t delPr is : psi \t1.6\n",
"\t delPT is : psi \t5.5\n",
"\t allowable delPT is 10 psi \t\n"
]
}
],
"source": [
"print\"\\t example 12.4 \\t\"\n",
"print\"\\t approximate values are mentioned in the book \\t\"\n",
"T1=130.; # inlet hot fluid,F\n",
"T2=125.; # outlet hot fluid,F\n",
"T3=100.; # after sucooling\n",
"t1=80.; # inlet cold fluid,F\n",
"t3=100.; # outlet cold fluid,F\n",
"W=21000; # lb/hr\n",
"w=167000; # lb/hr\n",
"from math import log10\n",
"print\"\\t 1.for heat balance \\t\"\n",
"print\"\\t for pentane \\t\"\n",
"HT1=315; # enthalpy at T1, Btu/lb\n",
"HT2=170; # enthalpy at T2, Btu/lb\n",
"qc=(W*(HT1-HT2)); # for condensation\n",
"print\"\\t total heat required for condensing of pentane is : Btu/hr \\t\",qc\n",
"c=0.57; # Btu/(lb)(F)\n",
"qs=((W)*(c)*(T2-T3)); # Btu/hr\n",
"print\"\\t total heat required for subcooling of pentane is : Btu/hr \\t\",qs\n",
"Q=qs+qc;\n",
"print\"\\t total heat required for pentane is : Btu/hr \\t\",Q\n",
"print\"\\t for water \\t\"\n",
"c=1; # Btu/(lb)*(F)\n",
"Q=((w)*(c)*(t3-t1)); # Btu/hr\n",
"print\"\\t total heat required for water is : Btu/hr \\t\",Q\n",
"deltw=(qc/w);\n",
"print\"\\t deltw is : F \\t\",deltw\n",
"t2=t3-deltw;\n",
"print\"\\t t2 is : F \\t\",t2\n",
"print\"\\t for condensing \\t\"\n",
"delt1=T2-t2; #F\n",
"delt2=T1-t3; # F\n",
"print\"\\t delt1 is : F \\t\",delt1\n",
"print\"\\t delt2 is : F \\t\",delt2\n",
"LMTDc=((delt2-delt1)/((2.3)*(log10(delt2/delt1))));\n",
"print\"\\t LMTD is : F \\t\",LMTDc\n",
"w1=(qc/LMTDc);\n",
"print\"\\t w1 is : lb/hr \\t\",w1\n",
"print\"\\t subcooling \\t\"\n",
"delt3=T3-t1; #F\n",
"delt4=T2-t2;\n",
"print\"\\t delt1 is : F \\t\",delt3\n",
"print\"\\t delt2 is : F \\t\",delt4\n",
"LMTDs=((delt4-delt3)/((2.3)*(log10(delt4/delt3))));\n",
"print\"\\t LMTD is f F \\t\",LMTDs\n",
"w2=(qs/LMTDs);\n",
"print\"\\t w1 is : lb/hr \\t\",w2\n",
"delt=(Q/(w1+w2));\n",
"print\"\\t delt is : F \\t\",delt\n",
"Tc=((T1)+(T2))/(2); # caloric temperature of hot fluid,F\n",
"print\"\\t caloric temperature of hot fluid is : F \\t\",Tc\n",
"tc=((t1)+(t3))/(2); # caloric temperature of cold fluid,F\n",
"print\"\\t caloric temperature of cold fluid is : F \\t\",tc\n",
"print\"\\t hot fluid:shell side,pentane \\t\"\n",
"print\"\\t for condensaton \\t\"\n",
"Do=0.0625; # ft\n",
"Nt=370; # number of tubes\n",
"G1=(W/(3.14*Nt*Do)); # from eq.12.42\n",
"print\"\\t G1 is : lb/(hr)*(lin ft) \\t\",G1\n",
"print\"\\t cold fluid:inner tube side,water \\t\"\n",
"n=4; # number of passes\n",
"L=16; #ft\n",
"at1=0.302; # flow area, in**2\n",
"at=((Nt*at1)/(144*n)); # total area,ft**2,from eq.7.48\n",
"print\"\\t flow area is : ft**2 \\t\",at\n",
"Gt=(w/(at)); # mass velocity,lb/(hr)*(ft**2)\n",
"print\"\\t mass velocity is : lb/(hr)*(ft**2) \\t\",Gt\n",
"V=(Gt/(3600*62.5));\n",
"print\"\\t V is : fps \\t\",V\n",
"mu2=1.98; # at 90F,lb/(ft)*(hr)\n",
"D=0.0517; # ft\n",
"Ret=((D)*(Gt)/mu2); # reynolds number\n",
"print\"\\t reynolds number is : %.2e \\t\",Ret\n",
"hi=940; #Btu/(hr)*(ft**2)*(F)\n",
"print\"\\t hi is : Btu/(hr)*(ft**2)*(F) \\t\",hi\n",
"ID=0.62; # ft\n",
"OD=0.75; #ft\n",
"hio=((hi)*(ID/OD)); # using eq.6.5\n",
"print\"\\t Correct hio to the surface at the OD is : Btu/(hr)*(ft**2)*(F) \\t\",hio\n",
"ho=125; # assumption\n",
"tw=(tc)+(((ho)/(hio+ho))*(Tc-tc)); # from eq.5.31\n",
"print\"\\t tw is : F \\t\",tw\n",
"tf=(Tc+tw)/(2); # from eq 12.19\n",
"print\"\\t tf is : F \\t\",tf\n",
"kf=0.077; # Btu/(hr)*(ft**2)*(F/ft), table 4\n",
"sf=0.6; # from table 6\n",
"muf=0.19; # cp, from fig 14\n",
"ho=120; # Btu/(hr)*(ft**2)*(F), from fig 12.9\n",
"print\"\\t Correct ho 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",
"Ac=(3040000/(104*36.4));\n",
"print\"\\t clean surface required for dcondensation : ft**2 \\t\",Ac\n",
"print\"\\t subcooling \\t\"\n",
"ID=25; # in\n",
"C=0.25; # clearance\n",
"B=12; # baffle spacing,in\n",
"PT=1;\n",
"As=((ID*C*B)/(144*PT)); # flow area,ft**2\n",
"print\"\\t flow area is : ft**2 \\t\",As\n",
"Gs=(W/As); # mass velocity,lb/(hr)*(ft**2)\n",
"print\"\\t mass velocity is : lb/(hr)*(ft**2) \\t\",Gs\n",
"mu1=0.46; # at 112.5F,lb/(ft)*(hr), from fig.14\n",
"De=0.95/12; # from fig.28,ft\n",
"Res=((De)*(Gs)/mu1); # reynolds number\n",
"print\"\\t reynolds number is : \\t\",Res\n",
"jH=46.5; # from fig.28\n",
"k=0.077; # Btu/(hr)*(ft**2)*(F/ft), from table 4\n",
"Z=1.51; # Z=((c)*(mu1)/k)**(1/3)\n",
"ho=((jH)*(k/De)*(Z)); # using eq.6.15b,Btu/(hr)*(ft**2)*(F)\n",
"print\"\\t individual heat transfer coefficient is : Btu/(hr)*(ft**2)*(F) \\t\",ho\n",
"Us=((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\",Us\n",
"As=(qs/(Us*LMTDs));\n",
"print\"\\t clean surface required for desuperheating : ft**2 \\t\",As\n",
"AC=As+Ac;\n",
"print\"\\t total clean surface : ft**2 \\t\",AC\n",
"UC=((Us*As)+(Uc*Ac))/(AC);\n",
"print\"\\t weighted clean overall coefficient : Btu/(hr)*(ft**2)*(F) \\t\",UC\n",
"A2=0.1963; # actual surface supplied for each tube,ft**2,from table 10\n",
"A=(Nt*L*A2); # ft**2\n",
"print\"\\t total surface area is : ft**2 \\t\",A\n",
"UD=((Q)/((A)*(delt)));\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",
"print\"\\t condensation \\t\"\n",
"Lc=13.4; #ft\n",
"De=0.0792; # fig 28\n",
"f=0.0012; # friction factor for reynolds number 193000, using fig.29\n",
"mu3=0.0165; # at 127.5F\n",
"Ds=2.08; # ft\n",
"phys=1;\n",
"Res1=(De*Gs/mu3);\n",
"print\"\\t reynolds number is \\t\",Res1\n",
"rowvap=(72.2/((359)*(590/492)*(14.7/25)));\n",
"print\"\\t rowvapour is ld/ft**3 \\t\",rowvap\n",
"s=(rowvap/62.5);\n",
"print\"\\t s is \\t\",s\n",
"N=(12*Lc/B)+(1); # number of crosses,using eq.7.43\n",
"print\"\\t number of crosses are : \\t\",N\n",
"delPsc=((f*(Gs**2)*(Ds)*(N))/(5.22*(10**10)*(De)*(s)*(phys)))/(2); # using eq.12.47,psi\n",
"print\"\\t delPsc is : psi \\t\",delPsc\n",
"print\"\\t delPss is negligible \\t\"\n",
"print\"\\t allowable delPa is 2 psi \\t\"\n",
"print\"\\t pressure drop for inner pipe \\t\"\n",
"f=0.00022; # friction factor for reynolds number 22500, using fig.26\n",
"s=1;\n",
"phyt=1;\n",
"delPt=((f*(Gt**2)*(L)*(n))/(5.22*(10**10)*(D)*(s)*(phyt))); # using eq.7.45,psi\n",
"print\"\\t delPt is : psi \\t\",round(delPt,1)\n",
"X1=0.1; # X1=((V**2)/(2*g)),using fig.27\n",
"delPr=((4*n*X1)/(s)); # using eq.7.46,psi\n",
"print\"\\t delPr is : psi \\t\",delPr\n",
"delPT=delPt+delPr; # using eq.7.47,psi\n",
"print\"\\t delPT is : psi \\t\",round(delPT,1)\n",
"print\"\\t allowable delPT is 10 psi \\t\"\n",
"#end\n"
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"## Example 12.5 pgno:295"
]
},
{
"cell_type": "code",
"execution_count": 5,
"metadata": {
"collapsed": false
},
"outputs": [
{
"name": "stdout",
"output_type": "stream",
"text": [
"\t example 12.5 \t\n",
"\t approximate values are mentioned in the book \t\n",
"\t 1.for heat balance \t\n",
"\t for pentane \t\n",
"\t total heat required for subcooling of pentane is : Btu/hr \t299250.0\n",
"\t total heat required for condensing of pentane is : Btu/hr \t3045000\n",
"\t total heat required for pentane is : Btu/hr \t3344250.0\n",
"\t for water \t\n",
"\t total heat required for water is : Btu/hr \t3340000\n",
"\t deltw is : F \t18.2\n",
"\t t2 is : F \t81.8\n",
"\t for condensing \t\n",
"\t delt1 is : F \t43.2\n",
"\t delt2 is : F \t30\n",
"\t LMTD is : F \t36.2404655222\n",
"\t w1 is : lb/hr \t84022.0994992\n",
"\t subcooling \t\n",
"\t delt1 is : F \t20\n",
"\t delt2 is : F \t43.2\n",
"\t LMTD is : F \t30.1594958556\n",
"\t w1 is : lb/hr \t9922.24808506\n",
"\t delt is : % F \t35.5529639184\n",
"\t caloric temperature of hot fluid is : F \t127\n",
"\t caloric temperature of cold fluid is : F \t90\n",
"\t hot fluid:shell side,pentane \t\n",
"\t a is : in**2 \t123.75\n",
"\t number of submerged tubes are : \t93.3248407643\n",
"\t number of tubes for condensation are : \t276.675159236\n",
"\t flooded surface : \t0.252229299363\n",
"\t for condensaton \t\n",
"\t G1 is : lb/(hr)*(lin ft) \t1312.5\n",
"\t cold fluid:inner tube side,water \t\n",
"\t flow area is : ft**2 \t0.145062323071\n",
"\t mass velocity is : lb/(hr)*(ft**2) \t1151229.32312\n",
"\t V is : fps \t5.11657476943\n",
"\t reynolds number is : \t30059.8767704\n",
"\t hi is : Btu/(hr)*(ft**2)*(F) \t940\n",
"\t Correct hio to the surface at the OD is : Btu/(hr)*(ft**2)*(F) \t777.066666667\n",
"\t Correct ho to the surface at the OD is : Btu/(hr)*(ft**2)*(F) \t251\n",
"\t clean overall coefficient is : Btu/(hr)*(ft**2)*(F) \t189.718954672\n",
"\t clean surface required for dcondensation : ft**2 \t442.876673258\n",
"\t subcooling \t\n",
"\t individual heat transfer coefficient is : Btu/(hr)*(ft**2)*(F) \t50\n",
"\t clean overall coefficient is : Btu/(hr)*(ft**2)*(F) \t46.9772690634\n",
"\t clean surface required for desuperheating : ft**2 \t211.213812188\n",
"\t total clean surface : ft**2 \t654.090485446\n",
"\t weighted clean overall coefficient : Btu/(hr)*(ft**2)*(F) \t143.625919769\n",
"\t total surface area is : ft**2 \t1160\n",
"\t actual design overall coefficient is : Btu/(hr)*(ft**2)*(F) \t80.9865065381\n",
"\t actual Rd is : (hr)*(ft**2)*(F)/Btu \t0.0054\n",
"\t pressure drop for annulus \t\n",
"\t condensation \t\n",
"\t It will be necessary to spread the batHes to a spacing of 18in.to compensate for the reduction in crossfiow area due to the flooded subcooling zone. The tube-side pressure drop will be the same as before. Assume bundle flooded to 0.3Ds.\t\n",
"\t mass velocity is : lb/(hr)*(ft**2) \t38391.2248629\n",
"\t reynolds number is : \t184277.879342\n",
"\t number of crosses are : \t10\n",
"\t delPsc is : psi \t1.0\n",
"\t delPss is negligible \t\n",
"\t allowable delPa is 2 psi \t\n"
]
}
],
"source": [
"print\"\\t example 12.5 \\t\"\n",
"print\"\\t approximate values are mentioned in the book \\t\"\n",
"T1=130; # inlet hot fluid,F\n",
"T2=125; # outlet hot fluid,F\n",
"T3=100; # after subcooling\n",
"t1=80; # inlet cold fluid,F\n",
"t3=100; # outlet cold fluid,F\n",
"W=21000; # lb/hr\n",
"w=167000; # lb/hr\n",
"from math import log10\n",
"print\"\\t 1.for heat balance \\t\"\n",
"print\"\\t for pentane \\t\"\n",
"c=0.57; # Btu/(lb)(\n",
"qs=((W)*(c)*(T2-T3)); # Btu/hr\n",
"print\"\\t total heat required for subcooling of pentane is : Btu/hr \\t\",qs\n",
"HT1=315; # enthalpy at T1, Btu/lb\n",
"HT2=170; # enthalpy at T2, Btu/lb\n",
"qc=(W*(HT1-HT2)); # for condensation\n",
"print\"\\t total heat required for condensing of pentane is : Btu/hr \\t\",qc\n",
"Q=qs+qc;\n",
"print\"\\t total heat required for pentane is : Btu/hr \\t\",Q\n",
"print\"\\t for water \\t\"\n",
"c=1; # Btu/(lb)*(F)-++++++++-\n",
"Q=((w)*(c)*(t3-t1)); # Btu/hr\n",
"print\"\\t total heat required for water is : Btu/hr \\t\",Q\n",
"deltw=18.2;\n",
"print\"\\t deltw is : F \\t\",deltw\n",
"t2=t3-deltw;\n",
"print\"\\t t2 is : F \\t\",t2\n",
"print\"\\t for condensing \\t\"\n",
"delt1=T2-t2; #F\n",
"delt2=T1-t3; # F\n",
"print\"\\t delt1 is : F \\t\",delt1\n",
"print\"\\t delt2 is : F \\t\",delt2\n",
"LMTDc=((delt2-delt1)/((2.3)*(log10(delt2/delt1))));\n",
"print\"\\t LMTD is : F \\t\",LMTDc\n",
"w1=(qc/LMTDc);\n",
"print\"\\t w1 is : lb/hr \\t\",w1\n",
"print\"\\t subcooling \\t\"\n",
"delt3=T3-t1; #F\n",
"delt4=T2-t2; # F\n",
"print\"\\t delt1 is : F \\t\",delt3\n",
"print\"\\t delt2 is : F \\t\",delt4\n",
"LMTDs=((delt4-delt3)/((2.3)*(log10(delt4/delt3))));\n",
"print\"\\t LMTD is : F \\t\",LMTDs\n",
"w2=(qs/LMTDs);\n",
"print\"\\t w1 is : lb/hr \\t\",w2\n",
"delt=(Q/(w1+w2));\n",
"print\"\\t delt is : % F \\t\",delt\n",
"Tc=((T1)+(T2))/(2); # caloric temperature of hot fluid,F\n",
"print\"\\t caloric temperature of hot fluid is : F \\t\",Tc\n",
"tc=((t1)+(t3))/(2); # caloric temperature of cold fluid,F\n",
"print\"\\t caloric temperature of cold fluid is : F \\t\",tc\n",
"print\"\\t hot fluid:shell side,pentane \\t\"\n",
"C1=0.198; # for 0.3Ds\n",
"Ds=25; # in\n",
"L=16; # ft\n",
"N=370\n",
"a=(C1*Ds**2);\n",
"print\"\\t a is : in**2 \\t\",a\n",
"N1=((N*a*4)/(3.14*Ds**2));\n",
"print\"\\t number of submerged tubes are : \\t\",N1\n",
"Nt=N-N1;\n",
"print\"\\t number of tubes for condensation are : \\t\",Nt\n",
"Af=(N1/N);\n",
"print\"\\t flooded surface : \\t\",Af\n",
"print\"\\t for condensaton \\t\"\n",
"G1=(W/(L*Nt**(2/3))); # from eq.12.43\n",
"print\"\\t G1 is : lb/(hr)*(lin ft) \\t\",G1\n",
"print\"\\t cold fluid:inner tube side,water \\t\"\n",
"n=4; # number of passes\n",
"L=16; #ft\n",
"at1=0.302; # flow area, in**2\n",
"at=((Nt*at1)/(144*n)); # total area,ft**2,from eq.7.48\n",
"print\"\\t flow area is : ft**2 \\t\",at\n",
"Gt=(w/(at)); # mass velocity,lb/(hr)*(ft**2)\n",
"print\"\\t mass velocity is : lb/(hr)*(ft**2) \\t\",Gt\n",
"V=(Gt/(3600*62.5));\n",
"print\"\\t V is : fps \\t\",V\n",
"mu2=1.98; # lb/(ft)*(hr)\n",
"D=0.0517; # ft\n",
"Ret=((D)*(Gt)/mu2); # reynolds number\n",
"print\"\\t reynolds number is : \\t\",Ret\n",
"hi=940; #Btu/(hr)*(ft**2)*(F)\n",
"print\"\\t hi is : Btu/(hr)*(ft**2)*(F) \\t\",hi\n",
"ID=0.62; # ft\n",
"OD=0.75; #ft\n",
"hio=((hi)*(ID/OD)); # using eq.6.5\n",
"print\"\\t Correct hio to the surface at the OD is : Btu/(hr)*(ft**2)*(F) \\t\",hio\n",
"ho=251; # Btu/(hr)*(ft**2)*(F), from fig 12.9\n",
"print\"\\t Correct ho 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",
"Ac=(qc/(Uc*LMTDc));\n",
"print\"\\t clean surface required for dcondensation : ft**2 \\t\",Ac\n",
"print\"\\t subcooling \\t\"\n",
"ho=50; # Btu/(hr)*(ft**2)*(F)\n",
"print\"\\t individual heat transfer coefficient is : Btu/(hr)*(ft**2)*(F) \\t\",ho\n",
"Us=((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\",Us\n",
"As=(qs/(Us*LMTDs));\n",
"print\"\\t clean surface required for desuperheating : ft**2 \\t\",As\n",
"AC=As+Ac;\n",
"print\"\\t total clean surface : ft**2 \\t\",AC\n",
"UC=((Us*As)+(Uc*Ac))/(AC);\n",
"print\"\\t weighted clean overall coefficient : Btu/(hr)*(ft**2)*(F) \\t\",UC\n",
"A=1160; # ft**2\n",
"print\"\\t total surface area is : ft**2 \\t\",A\n",
"UD=((Q)/((A)*(delt)));\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\",round(Rd,4)\n",
"print\"\\t pressure drop for annulus \\t\"\n",
"print\"\\t condensation \\t\"\n",
"print\"\\t It will be necessary to spread the batHes to a spacing of 18in.to compensate for the reduction in crossfiow area due to the flooded subcooling zone. The tube-side pressure drop will be the same as before. Assume bundle flooded to 0.3Ds.\\t\"\n",
"As=0.547; # ft**2\n",
"Gs=(W/(As)); # mass velocity,lb/(hr)*(ft**2)\n",
"print\"\\t mass velocity is : lb/(hr)*(ft**2) \\t\",Gs\n",
"De=0.0792; # fig 28\n",
"Res=((De)*(Gs)/0.0165); # reynolds number\n",
"print\"\\t reynolds number is : \\t\",Res\n",
"f=0.00121; # friction factor for reynolds number 193000, using fig.29\n",
"s=0.00454; # for reynolds number 193000,using fig.6\n",
"Ds=2.08; # ft\n",
"B=18\n",
"phys=1;\n",
"N=(12*L/B); # number of crosses,using eq.7.43\n",
"print\"\\t number of crosses are : \\t\",N\n",
"delPsc=((f*(Gs**2)*(Ds)*(N))/(5.22*(10**10)*(De)*(s)*(phys)))/(2); # using eq.12.47,psi\n",
"print\"\\t delPsc is : psi \\t\",round(delPsc)\n",
"print\"\\t delPss is negligible \\t\"\n",
"print\"\\t allowable delPT is 10 psi \\t\"\n",
"#e \n"
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"## Example 12.6 pgno:299"
]
},
{
"cell_type": "code",
"execution_count": 8,
"metadata": {
"collapsed": false
},
"outputs": [
{
"name": "stdout",
"output_type": "stream",
"text": [
"\t example 12.6 \t\n",
"\t approximate values are mentioned in the book \t\n",
"\t 1.for heat balance \t\n",
"\t for carbon disulfide \t\n",
"\t total heat required for carbon disulfide is : Btu/hr \t4200000\n",
"\t for water \t\n",
"\t total heat required for water is : Btu/hr \t4200000.0\n",
"\t delt1 is : F \t91.0\n",
"\t delt2 is : F \t56.0\n",
"\t LMTD is : F \t72.1704928998\n",
"\t caloric temperature of hot fluid is : F \t176.0\n",
"\t caloric temperature of cold fluid is : F \t102.5\n",
"\t hot fluid:inner tube side,carbon disulfide \t\n",
"\t cold fluid:shell side,water \t\n",
"\t flow area is : ft**2 \t0.1796875\n",
"\t mass velocity is : lb/(hr)*(ft**2) \t667826.086957\n",
"\t reynolds number is : \t31112.8388747\n",
"\t individual heat transfer coefficient is : Btu/(hr)*(ft**2)*(F) \t786.545454545\n",
"\t tw is : F \t122.793674699\n",
"\t tf is : F \t149.396837349\n",
"\t hot fluid:inner tube side,carbon disulfide \t\n",
"\t G1 is : lb/(hr)*(lin ft) \t1044.06562495\n",
"\t reynolds number is : \t6141.56249973\n",
"\t hi is : Btu/(hr)*(ft**2)*(F) \t0.251\n",
"\t Correct hio1 to the surface at the OD is : Btu/(hr)*(ft**2)*(F) \t0.207493333333\n",
"\t clean overall coefficient is : Btu/(hr)*(ft**2)*(F) \t0.207438610331\n",
"\t total surface area is : ft**2 \t555.9216\n",
"\t actual design overall coefficient is : Btu/(hr)*(ft**2)*(F) \t104.682978368\n",
"\t actual Rd is : (hr)*(ft**2)*(F)/Btu \t-4.81115068056\n",
"\t pressure drop for inner pipe \t\n",
"\t flow area is : ft**2 \t0.371208333333\n",
"\t mass velocity is : lb/(hr)*(ft**2) \t80645.1612903\n",
"\t reynolds number is : \t143770.856507\n",
"\t row is ld/ft**3 \t0.572484035397\n",
"\t s is \t0.00915974456635\n",
"\t delPt is : psi \t0.4\n",
"\t allowable delPa is negligible psi \t\n",
"\t pressure drop for annulus \t\n",
"\t number of crosses are : \t32.0\n",
"\t delPs is : psi \t8.4\n",
"\t allowable delPT is 2 psi \t\n"
]
}
],
"source": [
"print\"\\t example 12.6 \\t\"\n",
"print\"\\t approximate values are mentioned in the book \\t\"\n",
"T1=176.; # inlet hot fluid,F\n",
"T2=176.; # outlet hot fluid,F\n",
"t1=85.; # inlet cold fluid,F\n",
"t2=120.; # outlet cold fluid,F\n",
"W=30000; # lb/hr\n",
"w=120000; # lb/hr\n",
"from math import log10\n",
"print\"\\t 1.for heat balance \\t\"\n",
"print\"\\t for carbon disulfide \\t\"\n",
"l=140; # Btu/(lb)\n",
"Q=((W)*l); # Btu/hr\n",
"print\"\\t total heat required for carbon disulfide is : Btu/hr \\t\",Q\n",
"print\"\\t for water \\t\"\n",
"c=1; # Btu/(lb)*(F)\n",
"Q=((w)*(c)*(t2-t1)); # Btu/hr\n",
"print\"\\t total heat required for water is : Btu/hr \\t\",Q\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)/((2.3)*(log10(delt2/delt1))));\n",
"print\"\\t LMTD is : F \\t\",LMTD\n",
"Tc=((T2)+T1)/2; # caloric temperature of hot fluid,F\n",
"print\"\\t caloric temperature of hot fluid is : F \\t\",Tc\n",
"tc=((t1)+(t2))/2; # caloric temperature of cold fluid,F\n",
"print\"\\t caloric temperature of cold fluid is : F \\t\",tc\n",
"print\"\\t hot fluid:inner tube side,carbon disulfide \\t\"\n",
"hio=300; # Btu/(hr)*(ft**2)*(F)\n",
"print\"\\t cold fluid:shell side,water \\t\"\n",
"ID=17.25; # in\n",
"C=0.25; # clearance\n",
"B=6; # baffle spacing,in\n",
"PT=1;\n",
"As=((ID*C*B)/(144*PT)); # flow area,ft**2\n",
"print\"\\t flow area is : ft**2 \\t\",As\n",
"Gs=(w/As); # mass velocity,lb/(hr)*(ft**2)\n",
"print\"\\t mass velocity is : lb/(hr)*(ft**2) \\t\",Gs\n",
"mu1=1.7; # at 280F,lb/(ft)*(hr), from fig.14\n",
"De=0.0792; # from fig.28,ft\n",
"Res=((De)*(Gs)/mu1); # reynolds number\n",
"print\"\\t reynolds number is : \\t\",Res\n",
"jH=103; # from fig.28\n",
"k=0.36; # Btu/(hr)*(ft**2)*(F/ft), from fig.1\n",
"Z=1.68; # Z=((c)*(mu1)/k)**(1/3); # prandelt number\n",
"ho=((jH)*(k/De)*(Z)); # 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",
"tw=(tc)+(((hio)/(hio+ho))*(Tc-tc)); # from eq.5.31\n",
"print\"\\t tw is : F \\t\",tw\n",
"tf=(Tc+tw)/(2); # from eq 12.19\n",
"print\"\\t tf is : F \\t\",tf\n",
"print\"\\t hot fluid:inner tube side,carbon disulfide \\t\"\n",
"kf=0.09; # Btu/(hr)*(ft**2)*(F/ft), from fig 14\n",
"sf=1.26; # from table 6\n",
"rowf=78.8; # lb/ft**3\n",
"muf=0.68; # cp, from fig 24\n",
"Nt=177;\n",
"D=0.0517; # ft\n",
"G1=(W/(3.14*Nt*D));\n",
"print\"\\t G1 is : lb/(hr)*(lin ft) \\t\",G1\n",
"Ret=((4)*(G1)/muf); # reynolds number\n",
"print\"\\t reynolds number is : \\t\",Ret\n",
"hi=(0.251*(((kf**3)*(rowf**2)*(4.17*10**8))/(muf**2))**(1/3)); # hi*(((kf**3)*(rowf**2)*(4.17*10**8))/(muf**2))**(-1)=0.251, from fig 12.12\n",
"print\"\\t hi is : Btu/(hr)*(ft**2)*(F) \\t\",hi\n",
"ID=0.62; # ft\n",
"OD=.75; #ft\n",
"hio1=((hi)*(ID/OD)); #Hio=(hio/phyp), using eq.6.5\n",
"print\"\\t Correct hio1 to the surface at the OD is : Btu/(hr)*(ft**2)*(F) \\t\",hio1\n",
"Uc=((hio1)*(ho)/(hio1+ho)); # clean overall coefficient,Btu/(hr)*(ft**2)*(F)\n",
"print\"\\t clean overall coefficient is : Btu/(hr)*(ft**2)*(F) \\t\",Uc\n",
"A2=0.1963; # actual surface supplied for each tube,ft**2,from table 10\n",
"L=16;\n",
"A=(Nt*L*A2); # ft**2\n",
"print\"\\t total surface area is : ft**2 \\t\",A\n",
"UD=((Q)/((A)*(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 inner pipe \\t\"\n",
"n=1; # number of passes\n",
"at1=0.302; # flow area, in**2\n",
"at=((Nt*at1)/(144*n)); # total area,ft**2,from eq.7.48\n",
"print\"\\t flow area is : ft**2 \\t\",at\n",
"Gt=(30000/(0.372)); # mass velocity,lb/(hr)*(ft**2)\n",
"print\"\\t mass velocity is : lb/(hr)*(ft**2) \\t\",Gt\n",
"mu2=0.029; # at inlet,lb/(ft)*(hr)\n",
"Ret=((D)*(Gt)/mu2); # reynolds number\n",
"print\"\\t reynolds number is : \\t\",Ret\n",
"row=(76.1/((359)*(636/492)*(14.7/39.7)));\n",
"print\"\\t row is ld/ft**3 \\t\",row\n",
"s=(row/62.5);\n",
"print\"\\t s is \\t\",s\n",
"f=0.000138; # friction factor for reynolds number 143000, using fig.26\n",
"delPt=((f*(Gt**2)*(16)*(1))/(5.22*(10**10)*(0.0517)*(s)))/(2); # using eq.7.45,psi\n",
"print\"\\t delPt is : psi \\t\",round(delPt+0.1,1)\n",
"print\"\\t allowable delPa is negligible psi \\t\"\n",
"print\"\\t pressure drop for annulus \\t\"\n",
"f=0.0017; # friction factor for reynolds number 31000, using fig.29\n",
"s=1; # for reynolds number 31000,using fig.6\n",
"Ds=17.25/12.; # ft\n",
"B=6.;\n",
"N=(12*L/B); # number of crosses,using eq.7.43\n",
"print\"\\t number of crosses are : \\t\",N\n",
"delPs=((f*(Gs**2)*(Ds)*(N))/(5.22*(10**10)*(De)*(s))); # using eq.7.44,psi\n",
"print\"\\t delPs is : psi \\t\",round(delPs,1)\n",
"print\"\\t allowable delPT is 2 psi \\t\"\n",
"#end\n"
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"## Example 12.7 pgno:308"
]
},
{
"cell_type": "code",
"execution_count": 14,
"metadata": {
"collapsed": false
},
"outputs": [
{
"name": "stdout",
"output_type": "stream",
"text": [
"\t example 12.7 \t\n",
"\t approximate values are mentioned in the book \t\n",
"\t design overall coefficient is : Btu/(hr)*(ft**2)*(F) \t223.55\n",
"\t area is : ft**2 \t31250.0\n",
"\t t2 is : F \t86.0\n",
"\t circulation rate is : gpm \t29176.0\n"
]
}
],
"source": [
"print\"\\t example 12.7 \\t\"\n",
"print\"\\t approximate values are mentioned in the book \\t\"\n",
"V=7.5; # fps\n",
"W=250000.;\n",
"CCl=0.85;\n",
"CT=1.;\n",
"CL=1.;\n",
"Ct=263.;\n",
"UD=(CCl*CT*CL*Ct*(V**(1/2)));\n",
"print\"\\t design overall coefficient is : Btu/(hr)*(ft**2)*(F) \\t\",UD\n",
"A=(W/8);\n",
"print\"\\t area is : ft**2 \\t\",A\n",
"a1=0.229; # ft**2/ft, table 10\n",
"at=0.475; # in**2, table 10\n",
"t1=70;\n",
"Ts=91.72; #F\n",
"n=2;\n",
"L=26;\n",
"t2=((Ts)-((Ts-t1)/((10)**(0.000279*UD*L*n*a1/(V*at))))+8); \n",
"print\"\\t t2 is : F \\t\",round(t2) # calculation mistake in book\n",
"Go=(W*950)/((t2-t1)*500);\n",
"print\"\\t circulation rate is : gpm \\t\",round(Go)\n",
"# end\n",
"\n"
]
}
],
"metadata": {
"kernelspec": {
"display_name": "Python 2",
"language": "python",
"name": "python2"
},
"language_info": {
"codemirror_mode": {
"name": "ipython",
"version": 2
},
"file_extension": ".py",
"mimetype": "text/x-python",
"name": "python",
"nbconvert_exporter": "python",
"pygments_lexer": "ipython2",
"version": "2.7.9"
}
},
"nbformat": 4,
"nbformat_minor": 0
}