{ "cells": [ { "cell_type": "markdown", "metadata": {}, "source": [ "# Chapter 2 : Analysis of Steam Cycles" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "## Ex: 2.1 Pg: 82" ] }, { "cell_type": "code", "execution_count": 2, "metadata": { "collapsed": false }, "outputs": [ { "name": "stdout", "output_type": "stream", "text": [ "(a)Power output of the cycle is 1746.3 kW \n", " Efficiency of the cycle is 35.1 percent \n", "\n", " (b)Without geothermal heat supply \n", " Power output of the cycle is 955.17 kW \n", " Efficiency of the cycle is 19.22 percent\n" ] } ], "source": [ "#Input data\n", "p1=40#Initial pressure of steam in bar\n", "T1=500#Initial temperature of steam in degree C\n", "m1=5500#Rate of steam in kg/h\n", "p2=2#Pressure of steam after expansion in bar\n", "n1=0.83#Isentropic efficiency \n", "q=0.87#Quality\n", "m2=2700#Mass flow rate in kg/h\n", "p3=0.1#Pressure of steam after expansion in l.p turbine in bar\n", "n2=0.78#Isentropic efficiency\n", "\n", "#Calculations\n", "h1=3445.3#Enthalpy in kJ/kg\n", "s1=7.0901#Entropy in kJ/kg.K which is 1.5301+x2s*5.5970\n", "x2s=(5.5600/5.5970)#dryness fraction\n", "h2s=(504.7+(x2s*2201.9))#Enthalpy in kJ/kg\n", "h2=h1-(n1*(h1-h2s))#Enthalpy in kJ/kg\n", "h3=(504.7+(q*2201.9))#Enthalpy in kJ/kg\n", "h4=((m2*h3+m1*h2)/(m1+m2))#Enthalpy in kJ/kg\n", "x4=(2183.78/2201.9)#dryness fraction\n", "s4=(1.5301+x4*5.5970)#Entropy in kJ/kg.K\n", "x5s=0.8574#dryness fraction\n", "h5s=(191.84+x5s*2392.5)#Enthalpy in kJ/kg\n", "dh4h5=(n2*(h4-h5s))#Difference in enthalpy (h4-h5) in kJ/kg\n", "h6=191.83#Enthalpy in kJ/kg\n", "W1=((m1*(h1-h2))+((m1+m2)*dh4h5))/3600#Power output of the plant in kW\n", "Q1=(m1*(h1-h6))/3600#Heat input in kW\n", "n1=(W1/Q1)*100#Efficiency in percent\n", "WT=(m1*(h1-h2))/3600#Power output without the geothermal heat supply in kW\n", "Q2=(m1*(h1-h6))/3600#Heat input without the geothermal heat supply in kW\n", "n2=(WT/Q2)*100#Efficiency of the cycle without the geothermal heat supply in percent\n", "\n", "#Output\n", "print \"(a)Power output of the cycle is %3.1f kW \\n Efficiency of the cycle is %3.1f percent \\n\\n (b)Without geothermal heat supply \\n Power output of the cycle is %3.2f kW \\n Efficiency of the cycle is %3.2f percent\"%(W1,n1,WT,n2)" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "## Ex: 2.2 Pg: 83" ] }, { "cell_type": "code", "execution_count": 3, "metadata": { "collapsed": false }, "outputs": [ { "name": "stdout", "output_type": "stream", "text": [ "(a)Mass flow rate of steam at turbine inlet is 452 kg/s \n", " (b)The cycle efficiency is 38.82 percent \n", " (c)Work ratio is 0.999\n" ] } ], "source": [ "#Input data\n", "p1=90#Initial pressure of steam in bar\n", "T1=500#Initial temperature of steam in degree C\n", "O=(500*1000)#Output in kW\n", "T2=40#Condensation temperature in degree C\n", "nhp=0.92#Efficiency of h.p turbine\n", "nlp=0.9#Efficiency of l.p turbine\n", "np=0.75#Isentropic efficiency of the pump \n", "TTD=-1.6#Temperature in degree C\n", "\n", "#Calculations\n", "p2=(0.2*p1)#Optimum reheat pressure in bar\n", "h1=3386.1#Enthalpy in kJ/kg\n", "s1=6.6576#Entropy in kJ/kg.K\n", "s2s=s1#Entropy in kJ/kg.K\n", "h2s=2915#Enthalpy in kJ/kg\n", "h3=3469.8#Enthalpy in kJ/kg\n", "s3=7.4825#Entropy in kJ/kg.K\n", "x4s=(s3-0.5725)/7.6845#Dryness fraction\n", "h4s=(167.57+x4s*2406.7)#Enthalpy in kJ/kg\n", "h5=167.57#Enthalpy in kJ/kg\n", "h7=883.42#Enthalpy in kJ/kg\n", "Wps=(0.001008*p1*10)#Workdone by the pump in kJ/kg\n", "h6s=176.64#Enthalpy in kJ/kg\n", "dh1h2=(nhp*(h1-h2s))#Difference in enthalpy (h1-h2) in kJ/kg\n", "h2=h1-dh1h2#Enthalpy in kJ/kg\n", "dh3h4=(nlp*(h3-h4s))#Difference in enthalpy (h3-h4) in kJ/kg\n", "h4=h3-dh3h4#Enthalpy in kJ/kg\n", "Wp=(Wps/np)#Workdone by the pump in kJ/kg\n", "h6=(Wp+h5)#Enthalpy in kJ/kg\n", "tsat=207.15#Saturation temperature at 18 bar in degree C\n", "t9=(tsat-TTD)#Temperature in degree C\n", "h9=875#Enthalpy in kJ/kg\n", "m=((h9-h6)/(h2-h7))#Mass of steam in kg\n", "WT=(dh1h2+(1-m)*dh3h4)#Workdone by the turbine in kJ/kg\n", "Wnet=(WT-Wp)#Net workdone in kJ/kg\n", "ws=(O/Wnet)#Mass flow rate of steam at turbine inlet in kg/s\n", "Q1=((h1-h9)+(1-m)*(h3-h2))#Heat input in kJ/kg\n", "n=(Wnet/Q1)*100#Efficiency of the cycle in percent\n", "Wr=(Wnet/WT)#Work ratio\n", "\n", "#Output\n", "print \"(a)Mass flow rate of steam at turbine inlet is %3.0f kg/s \\n (b)The cycle efficiency is %3.2f percent \\n (c)Work ratio is %3.3f\"%(ws,n,Wr)" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "## Ex: 2.3 Pg: 86" ] }, { "cell_type": "code", "execution_count": 4, "metadata": { "collapsed": false }, "outputs": [ { "name": "stdout", "output_type": "stream", "text": [ "The optimum pressure and temperature at different heaters are: \n", " Heater 1: t1 = 255.2 degree C and p1 = 4.33 MPa\n", " Heater 2: t2 = 224.5 degree C and p2 = 2.5318 MPa\n", " Heater 3: t3 = 193.8 degree C and p3 = 1.367 MPa\n", " Heater 4: t4 = 163.1 degree C and p4 = 0.6714 MPa\n", " Heater 5: t5 = 132.4 degree C and p5 = 0.2906 MPa\n", " Heater 6: t6 = 101.7 degree C and p6 = 0.108 MPa\n", " Heater 7: t7 = 71.0 degree C and p7 = 32.65 kPa\n" ] } ], "source": [ "#Input data\n", "p1=70#Pressure at which an ideal seam power plant operates in bar\n", "T1=550#Temperature at which an ideal seam power plant operates in degrees C\n", "p2=0.075#Pressure at which an ideal seam power plant operates in bar\n", "\n", "#Calculations\n", "TB=285.9#Saturation temperature at 70 bar in degree C\n", "TC=40.3#Saturation temperature at 0.075 bar in degree C\n", "Tr=(TB-TC)/(7+1)#Temperature rise per heater for maximum cycle efficiency in degree C\n", "t1=(TB-Tr)#Temperature at heater 1 in degree C\n", "P1=4.33#Pressure at heater 1 in MPa\n", "t2=(t1-Tr)#Temperature at heater 2 in degree C\n", "P2=2.5318#Pressure at heater 2 in MPa\n", "t3=(t2-Tr)#Temperature at heater 3 in degree C\n", "P3=1.367#Pressure at heater 3 in MPa\n", "t4=(t3-Tr)#Temperature at heater 4 in degree C\n", "P4=0.6714#Pressure at heater 4 in MPa\n", "t5=(t4-Tr)#Temperature at heater 5 in degree C\n", "P5=0.2906#Pressure at heater 5 in MPa\n", "t6=(t5-Tr)#Temperature at heater 6 in degree C\n", "P6=0.108#Pressure at heater 6 in MPa\n", "t7=(t6-Tr)#Temperature at heater 7 in degree C\n", "P7=32.65#Pressure at heater 7 in kPa\n", "\n", "#Output\n", "print \"The optimum pressure and temperature at different heaters are: \\n Heater 1: t1 = %3.1f degree C and p1 = %3.2f MPa\\n Heater 2: t2 = %3.1f degree C and p2 = %3.4f MPa\\n Heater 3: t3 = %3.1f degree C and p3 = %3.3f MPa\\n Heater 4: t4 = %3.1f degree C and p4 = %3.4f MPa\\n Heater 5: t5 = %3.1f degree C and p5 = %3.4f MPa\\n Heater 6: t6 = %3.1f degree C and p6 = %3.3f MPa\\n Heater 7: t7 = %3.1f degree C and p7 = %3.2f kPa\"%(t1,P1,t2,P2,t3,P3,t4,P4,t5,P5,t6,P6,t7,P7)" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "## Ex: 2.4 Pg: 87" ] }, { "cell_type": "code", "execution_count": 5, "metadata": { "collapsed": false }, "outputs": [ { "name": "stdout", "output_type": "stream", "text": [ "Percentage of total electricity generated which is consumed in running the auxiliaries is 7.32 percent\n" ] } ], "source": [ "#Input data\n", "ng=0.97#Efficiency of electric generator \n", "nt=0.95#Efficiency of turbine\n", "nb=0.92#Efficiency of boiler\n", "nc=0.42#Efficiency of cycle\n", "no=0.33#Efficiency of overall plant\n", "\n", "#Calculations\n", "na=(no/(ng*nt*nb*nc))#Efficiency of auxiliaries\n", "n=(1-na)*100#Percentage of total electricity generated which is consumed in running the auxiliaries\n", "\n", "#Output\n", "print \"Percentage of total electricity generated which is consumed in running the auxiliaries is %3.2f percent\"%(n)" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "## Ex: 2.5 Pg: 87" ] }, { "cell_type": "code", "execution_count": 6, "metadata": { "collapsed": false }, "outputs": [ { "name": "stdout", "output_type": "stream", "text": [ "Efficiency of steam generator is 91.54 percent \n", "\n", " Heat transfer per kg fuel in \n", " (i)economiser is 5.3155 MJ/kg \n", " (ii)boiler is 13.086 MJ/kg \n", " (iii)superheater is 4.665 MJ/kg \n", " (iv)air pre-heater is 3.392 MJ/kg \n", "\n", " Percentage of total heat absorption taking place in \n", " (i)economiser is 23.04 percent \n", " (ii)boiler is 56.73 percent \n", " (iii)superheater is 20.23 percent\n" ] } ], "source": [ "#Input data\n", "T1=140#Temperature with which feed water enters into economiser in degree C\n", "T2=[25,250]#Temperature from air is preheated to in degree C\n", "P1=60#Pressure with which steam leaves the drum in bar\n", "x1=0.98#Dryness fraction\n", "T3=450#Temperature with which steam leaves the superheater in degree C\n", "cc=25.2#Calorific value of coal in MJ/kg\n", "r=8.5#Rate of evaporation of steam per kg coal \n", "wf=1#Mass of coal in kg\n", "R=15#Air fuel ratio by mass\n", "Cpa=1.005#Specific heat of air at constant pressure in kJ/kg.K\n", "Cpw=4.2#Specific heat of water at constant pressure in kJ/kg.K\n", "\n", "#Calculations\n", "h1=(T1*Cpw)#Enthalpy in kJ/kg\n", "hf=1213.35#Enthalpy in kJ/kg\n", "h2=hf#Enthalpy in kJ/kg\n", "hfg=1571#Enthalpy in kJ/kg\n", "h4=3301.8#Enthalpy in kJ/kg\n", "h3=(hf+x1*hfg)#Enthalpy in kJ/kg\n", "n=((r*(h4-h1))/(wf*cc*1000))*100#Efficiency\n", "he=(r*(h2-h1))/wf*10**-3#Heat transfer in the economiser in MJ/kg\n", "hb=(r*(h3-h2))/wf*10**-3#Heat transfer in the boiler in MJ/kg\n", "hs=(r*(h4-h3))/wf*10**-3#Heat transfer in the superheater in MJ/kg\n", "ha=(R*Cpa*(T2[1]-T2[0]))/wf*10**-3#Heat transfer in the air preheater in MJ/kg\n", "pe=((h2-h1)/(h4-h1))*100#Percentage of total heat absorbed in the economiser in percent\n", "pb=((h3-h2)/(h4-h1))*100#Percentage of total heat absorbed in the boiler in percent\n", "ps=((h4-h3)/(h4-h1))*100#Percentage of total heat absorbed in the superheater in percent\n", "\n", "#Output\n", "print \"Efficiency of steam generator is %3.2f percent \\n\\n Heat transfer per kg fuel in \\n (i)economiser is %3.4f MJ/kg \\n (ii)boiler is %3.3f MJ/kg \\n (iii)superheater is %3.3f MJ/kg \\n (iv)air pre-heater is %3.3f MJ/kg \\n\\n Percentage of total heat absorption taking place in \\n (i)economiser is %3.2f percent \\n (ii)boiler is %3.2f percent \\n (iii)superheater is %3.2f percent\"%(n,he,hb,hs,ha,pe,pb,ps)" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "## Ex: 2.6 Pg: 88" ] }, { "cell_type": "code", "execution_count": 7, "metadata": { "collapsed": false }, "outputs": [ { "name": "stdout", "output_type": "stream", "text": [ "(a) The cycle efficiency is 48.58 percent \n", " (b) The feedwater temperature is 264 degree C \n", " (c) The steam rate is 2.69 kJ/kWh \n", " (d) The heat rate is 7411 kJ/kWh \n", " (e) The quality of steam at turbine exhaust is 0.8932 \n", " (f) The power output is 111.58 MW\n" ] } ], "source": [ "#Input data\n", "p1=150#Pressure of inlet steam in bar\n", "T1=550#Temperature of steam in degree C\n", "p2=20#Pressure after expansion in bar\n", "T2=500#Reheat temperature in degree C\n", "pc=0.075#Condenser pressure in bar\n", "php=50#Pressure of steam in h.p turbine in bar\n", "pip=[10,5,3]#Pressure of steam in i.p turbines in bar\n", "plp=1.5#Pressure of steam in l.p turbine in bar\n", "m=300*1000#Steam flow rate in kg/h\n", "\n", "#Calculations\n", "h1=3448.6#Enthalpy in kJ/kg\n", "h4=3467.6#Enthalpy in kJ/kg\n", "s1=6.5119#Entropy in kJ/kg.K\n", "s2=s1#Entropy in kJ/kg.K\n", "s3=s1#Entropy in kJ/kg.K\n", "s4=7.4317#Entropy in kJ/kg.K\n", "s5=s4#Entropy in kJ/kg.K\n", "s6=s5#Entropy in kJ/kg.K\n", "s7=s6#Entropy in kJ/kg.K\n", "s8=s7#Entropy in kJ/kg.K\n", "s9=s8#Entropy in kJ/kg.K\n", "t2=370#Temperature in degree C\n", "t3=245#Temperature in degree C\n", "t5=400#Temperature in degree C\n", "t6=300#Temperature in degree C\n", "t7=225#Temperature in degree C\n", "t8=160#Temperature in degree C\n", "h2=3112#Enthalpy in kJ/kg\n", "h3=2890#Enthalpy in kJ/kg\n", "h5=3250#Enthalpy in kJ/kg\n", "h6=3050#Enthalpy in kJ/kg\n", "h7=2930#Enthalpy in kJ/kg\n", "h8=2790#Enthalpy in kJ/kg\n", "x9=(s9-0.5764)/7.6751#Dryness fraction\n", "h9=168.79+x9*2406##Enthalpy in kJ/kg\n", "h10=168.79#Enthalpy in kJ/kg\n", "h11=h10+0.001*pip[1]*100#Enthalpy in kJ/kg\n", "h12=467.11#Enthalpy in kJ/kg\n", "t14=111.37#Temperature in degree C\n", "h14=467#Enthalpy in kJ/kg\n", "h13=h12#Enthalpy in kJ/kg\n", "h14=h13#Enthalpy in kJ/kg\n", "h15=h14#Enthalpy in kJ/kg\n", "h16=561.47#Enthalpy in kJ/kg\n", "h17=h16#Enthalpy in kJ/kg\n", "h18=640.23#Enthalpy in kJ/kg\n", "h19=h18+0.001*(p1-pip[1])*100#Enthalpy in kJ/kg\n", "h20=762.8#Enthalpy in kJ/kg\n", "h21=h20#Enthalpy in kJ/kg\n", "h22=1154.23#Enthalpy in kJ/kg\n", "h23=h22#Enthalpy in kJ/kg\n", "m1=((h23-h21)/(h2-h22))#Mass in kg\n", "m2=((h21-h19)-(m1*(h22-h20)))/(h5-h20)#Mass in kg\n", "m3=(((1-m1-m2)*(h18-h17))-((m1+m2)*(h20-h18)))/(h6-h18+h18-h17)#Mass in kg\n", "m4=((1-m1-m2-m3)*(h17-h15))/(h7-h16)#Mass in kg\n", "m5=(((1-m1-m2-m3-m4)*(h14-h11))-(m4*(h16-h12)))/(h8-h12+h14-h11)#Mass in kg\n", "WT=(h1-h2)+(1-m1)*(h2-h3)+(1-m1)*(h4-h5)+(1-m1-m2)*(h5-h6)+(1-m1-m2-m3)*(h6-h7)+(1-m1-m2-m3-m4)*(h7-h8)+(1-m1-m2-m3-m4-m5)*(h8-h9)#Workdone by turbine in kJ/kg\n", "Wp=(0.5+14.5+0.15)#Workdone in kJ/kg\n", "Wnet=(WT-Wp)#Net workdone in kJ/kg\n", "Q1=(h1-h23)+(1-m1)*(h4-h3)#Heat supplied in kJ/kg\n", "ncy=(Wnet/Q1)*100#Cycle efficiency in percent\n", "t23=264#Temperature in degree C\n", "sr=(3600/Wnet)#Steam rate in kJ/kWh\n", "hr=((Q1/Wnet)*3600)#Heat rate in kJ/kWh\n", "P=((Wnet*m)/3600)/10**3#Power output in MW\n", "\n", "#Output\n", "print \"(a) The cycle efficiency is %3.2f percent \\n (b) The feedwater temperature is %d degree C \\n (c) The steam rate is %3.2f kJ/kWh \\n (d) The heat rate is %3.0f kJ/kWh \\n (e) The quality of steam at turbine exhaust is %3.4f \\n (f) The power output is %3.2f MW\"%(ncy,t23,sr,hr,x9,P)" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "## Ex: 2.7 Pg: 92" ] }, { "cell_type": "code", "execution_count": 8, "metadata": { "collapsed": false }, "outputs": [ { "name": "stdout", "output_type": "stream", "text": [ "The steam condition required at inlet of the turbine: \n", " Enthalpy is 3085.3 kJ/kg \n", " Entropy is 6.6192 kJ/kg.K \n", " Pressure is 37.3 bar \n", " Temperature is 344 degree C\n" ] } ], "source": [ "#Input data\n", "m=10000#Mass flow rate of steam in kg/h\n", "p=3#Pressure of steam in bar\n", "P=1000#Power in kW\n", "n=0.7#Internal efficiency of turbine\n", "\n", "#Calculations\n", "dh=(P*3600)/m#Change in enthalpy in kJ/kg\n", "h2=2725.3#Enthalpy in kJ/kg from Fig. E2.7 \n", "h1=dh+h2#Enthalpy in kJ/kg \n", "dh1h2s=dh/n#Change in enthalpy in kJ/kg\n", "h2s=h1-dh1h2s#Enthalpy in kJ/kg\n", "x2s=(h2s-561.47)/2163.8#Dryness fraction\n", "s2s=1.6718+x2s*(6.999-1.6718)#Entropy in kJ/kg.K\n", "s1=s2s#Entropy in kJ/kg.K\n", "p1=37.3#Pressure in bar from Mollier diagram\n", "t1=344#Temperature in degree C\n", "\n", "#Output\n", "print \"The steam condition required at inlet of the turbine: \\n Enthalpy is %3.1f kJ/kg \\n Entropy is %3.4f kJ/kg.K \\n Pressure is %3.1f bar \\n Temperature is %d degree C\"%(h1,s1,p1,t1)" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "## Ex: 2.8 Pg: 93" ] }, { "cell_type": "code", "execution_count": 9, "metadata": { "collapsed": false }, "outputs": [ { "name": "stdout", "output_type": "stream", "text": [ "(a) the steam generation capacity of the bolier is 16.74 t/h \n", " (b) the heat input to the boiler is 15113.7 kW \n", " (c) the fuel burning rate of the bolier is 2.473 t/h \n", " (d) the heat rejected to the condensor is 8369 kW \n", " (e) the rate of flow of cooling water in the condensor is 0.333 m**3/s\n" ] } ], "source": [ "from __future__ import division\n", "#Input data\n", "Pl=5.6#Power load in MW\n", "Hl=1.163#Heat load in MW\n", "p1=40#Pressure in bar\n", "T1=500+273#Temperature in K\n", "p2=0.06#Pressure in bar\n", "p3=2#Pressure in bar\n", "CV=25#Calorific value in MJ/kg\n", "n=88#Boiler efficiency in percent\n", "T=6#Temperature rise in degree C\n", "\n", "#Calculations\n", "h1=3445.3#Enthalpy in kJ/kg\n", "s1=7.0901#Entropy in kJ/kg.K\n", "s2=s1#Entropy in kJ/kg.K\n", "s3=s1#Entropy in kJ/kg.K\n", "x2=(s2-1.5301)/5.5970#Dryness fraction\n", "h2=2706.7#Enthalpy in kJ/kg\n", "h26=2201.9#Difference in enthalpy in kJ/kg\n", "w=(Hl*10**3)/h26#Rate of steam extraction in kg/h\n", "x3=(s1-0.52)/7.815#Dryness fraction\n", "h3=(149.79+x3*2416)#Enthalpy in kJ/kg\n", "h4=149.79#Enthalpy in kJ/kg\n", "ws=((Pl*10**3+(w*(h2-h3)))/((h1-h2)+(h2-h3)))#Steam generation capacity in kg/s\n", "ws1=(ws*3600)/1000#Steam generation capacity in t/h\n", "h7=(504.7+(1.061*10**-3*(p1-p3)*100))#Enthalpy in kJ/kg\n", "h5=(149.79+(1.006*100*p1*10**-3))#Enthalpy in kJ/kg\n", "Q1=(((ws-w)*(h1-h5))+(w*(h1-h7)))#Heat input in kW\n", "wf=((Q1/1000)/((n/100)*CV))*(3600/1000)#Fuel burning rate in t/h\n", "Q2=((ws-w)*(h3-h4))#Heat rejected to the condensor in kW\n", "wc=(Q2/(4.187*T))/1000#Rate of flow of cooling water in m**3/s\n", "\n", "#Output\n", "print \"(a) the steam generation capacity of the bolier is %3.2f t/h \\n (b) the heat input to the boiler is %3.1f kW \\n (c) the fuel burning rate of the bolier is %3.3f t/h \\n (d) the heat rejected to the condensor is %3.0f kW \\n (e) the rate of flow of cooling water in the condensor is %3.3f m**3/s\"%(ws1,Q1,wf,Q2,wc)" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "## Ex: 2.9 Pg: 94" ] }, { "cell_type": "code", "execution_count": 10, "metadata": { "collapsed": false }, "outputs": [ { "name": "stdout", "output_type": "stream", "text": [ "(a) the steam quality at the exhaust of the h.p turbine is 0.956 \n", " (b) the power developed by the h.p turbine is 1154.62 kW \n", " (c) the isentropic efficiency of the h.p turbine is 76.61 percent\n" ] } ], "source": [ "#Input data\n", "m=21000#Steam rate in kg/h\n", "p1=17#Pressure in bar\n", "T1=230+273#Temperature in K\n", "P=132.56#Power in kW\n", "x2=0.957#Dryness fraction\n", "p2=3.5#Pressure in bar\n", "Pl=1337.5#Power in l.p turbine in kW\n", "p3=0.3#Pressure in bar\n", "x3=0.912#Dryness fraction\n", "\n", "#Calculations\n", "h1=2869.7#Enthalpy in kJ/kg\n", "s1=6.5408#Entropy in kJ/kg.K\n", "h2=(870.44+x2*1924.7)#Enthalpy in kJ/kg\n", "h3=h2#Enthalpy in kJ/kg\n", "h56=(Pl*3600)/m#Difference in Enthalpy in kJ/kg\n", "h6=(289.23+x3*2336.1)#Enthalpy in kJ/kg\n", "h5=2649.04#Enthalpy in kJ/kg\n", "s4s=s1#Entropy in kJ/kg.K\n", "x4s=(s4s-1.7275)/5.2130#Dryness fraction\n", "h4s=584.33+x4s*2148.1#Enthalpy in kJ/kg\n", "w=(P/(h1-h2))#Flow rate in kg/s\n", "ws=(m/3600)#Steam flow rate in kg/s\n", "h4=((ws*h5)-(w*h3))/(ws-w)#Enthalpy in kJ/kg\n", "x4=(h4-584.33)/2148.1#Dryness fraction\n", "W=(ws-w)*(h1-h4)#Power developed by h.p turbine in kW\n", "n=((h1-h4)/(h1-h4s))*100#Isentropic efficiency in percent\n", "\n", "#Output\n", "print \"(a) the steam quality at the exhaust of the h.p turbine is %3.3f \\n (b) the power developed by the h.p turbine is %3.2f kW \\n (c) the isentropic efficiency of the h.p turbine is %3.2f percent\"%(x4,W,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 }