{ "metadata": { "name": "", "signature": "sha256:abd75e2d0144cfdf6dd59935ddb4f9b5824ec80059ba3e73a72bf780292d0a06" }, "nbformat": 3, "nbformat_minor": 0, "worksheets": [ { "cells": [ { "cell_type": "heading", "level": 1, "metadata": {}, "source": [ "Chapter 12 : Vapour Power Cycles" ] }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 12.1 Page No : 475" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "# Variables\n", "# Part (a)\n", "P1 = 1e05;\n", "P2 = 10e05;\n", "vf = 0.001043;\n", "\n", "# Calculation and Results\n", "Wrev = vf*(P1-P2);\n", "print \"The work required in saturated liquid form is\",Wrev/1000,\"kJ/kg\"\n", "\n", "# Part (b)\n", "h1 = 2675.5; \n", "s1 = 7.3594;\n", "s2 = s1;\n", "h2 = 3195.5;\n", "Wrev1 = h1-h2;\n", "print \"The work required in saturated vapour form is\",Wrev1,\"kJ/kg\"\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The work required in saturated liquid form is -0.9387 kJ/kg\n", "The work required in saturated vapour form is -520.0 kJ/kg\n" ] } ], "prompt_number": 1 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 12.2 Page No : 476" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "# Variables\n", "h1 = 3159.3;\n", "s1 = 6.9917;\n", "h3 = 173.88; \n", "s3 = 0.5926; \n", "sfp2 = s3; \n", "hfp2 = h3;\n", "hfgp2 = 2403.1; \n", "sgp2 = 8.2287;\n", "vfp2 = 0.001008; \n", "sfgp2 = 7.6361;\n", "\n", "# Calculation and Results\n", "x2s = (s1-sfp2)/(sfgp2);\n", "h2s = hfp2+(x2s*hfgp2);\n", "\n", "# Part (a)\n", "P1 = 20e02; \n", "P2 = 0.08e02;\n", "h4s = vfp2*(P1-P2)+h3 ; \n", "Wp = h4s-h3;\n", "Wt = h1-h2s;\n", "Wnet = Wt-Wp;\n", "Q1 = h1-h4s;\n", "n_cycle = Wnet/Q1;\n", "print \"Net work per kg of steam is %.2f kJ/Kg\"%Wnet\n", "print \"Cycle efficiency is %.3f\"%n_cycle\n", "\n", "# Part (b)\n", "n_p = 0.8; \n", "n_t = 0.8;\n", "Wp_ = Wp/n_p;\n", "Wt_ = Wt*n_t;\n", "Wnet_ = Wt_-Wp_;\n", "P = 100*((Wnet-Wnet_)/Wnet) ;\n", "n_cycle_ = Wnet_/Q1;\n", "P_ = 100*((n_cycle-n_cycle_)/n_cycle);\n", "print \"Percentage reduction in net work per kg of steam is %.1f %%\"%P\n", "print \"Percentage reduction in cycle efficiency is %.1f %%\"%P_\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Net work per kg of steam is 969.60 kJ/Kg\n", "Cycle efficiency is 0.325\n", "Percentage reduction in net work per kg of steam is 20.1 %\n", "Percentage reduction in cycle efficiency is 20.1 %\n" ] } ], "prompt_number": 4 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 12.3 Page No : 477" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "# Variables\n", "P1 = 0.08; \t\t\t# in bar\n", "sf = 0.5926; \n", "x2s = 0.85; \n", "sg = 8.2287; \n", "\n", "# Calculation\n", "s2s = sf+(x2s*(sg-sf));\n", "s1 = s2s;\n", "P2 = 16.832; \t\t\t# by steam table opposite to s1 in bar\n", "h1 = 3165.54;\n", "h2s = 173.88 + (0.85*2403.1);\n", "h3 = 173.88;\n", "vfp2 = 0.001;\n", "h4s = h3 + (vfp2*(P2-P1)*100);\n", "Q1 = h1-h4s;\n", "Wt = h1-h2s;\n", "Wp = h4s-h3;\n", "n_cycle = 100*((Wt-Wp)/Q1);\n", "Tm = (h1-h4s)/(s2s-sf);\n", "\n", "# Results\n", "print \"The greatest allowable steam pressure at the turbine inlet is\",P2,\"bar\"\n", "print \"Rankine cycle efficiency is %.2f %%\"%n_cycle\n", "print \"Mean temperature of heat addition is %.2f K\"%Tm\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The greatest allowable steam pressure at the turbine inlet is 16.832 bar\n", "Rankine cycle efficiency is 31.68 %\n", "Mean temperature of heat addition is 460.66 K\n" ] } ], "prompt_number": 3 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 12.4 Page No : 478" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "# Variables\n", "h1 = 3465.;\n", "h2s = 3065.; \n", "h3 = 3565.;\n", "h4s = 2300.; \n", "x4s = 0.88; \n", "h5 = 191.83;\n", "v = 0.001;\n", "P = 150.; \t\t\t# in bar\n", "\n", "# Calculation\n", "Wp = v*P*100;\n", "h6s = 206.83;\n", "Q1 = (h1-h6s)+(h3-h2s);\n", "Wt = (h1-h2s)+(h3-h4s);\n", "Wnet = Wt-Wp;\n", "n_cycle = 100*Wnet/Q1;\n", "sr = 3600/Wnet;\n", "\n", "# Results\n", "print \"Quality at turbine exhaust is\",0.88\n", "print \"Cycle efficiency is %.1f %%\"%n_cycle\n", "print \"steam rate is %.2f Kg/kW h\"%sr\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Quality at turbine exhaust is 0.88\n", "Cycle efficiency is 43.9 %\n", "steam rate is 2.18 Kg/kW h\n" ] } ], "prompt_number": 8 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 12.5 Page No : 479" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "# Variables\n", "h1 = 3230.9; \n", "s1 = 6.9212; \n", "s2 = s1; \n", "s3 = s1;\n", "h2 = 2796; \n", "sf = 0.6493; \n", "sfg = 7.5009;\n", "\n", "# Calculation\n", "x3 = (s3-sf)/sfg;\n", "h3 = 191.83 + x3*2392.8;\n", "h4 = 191.83; h5 = h4;\n", "h6 = 640.23; h7 = h6;\n", "m = (h6-h5)/(h2-h5);\n", "Wt = (h1-h2)+(1-m)*(h2-h3);\n", "Q1 = h1-h6;\n", "n_cycle = 100*Wt/Q1;\n", "sr = 3600/Wt;\n", "s7 = 1.8607; s4 = 0.6493;\n", "Tm = (h1-h7)/(s1-s7);\n", "Tm1 = (h1-h4)/(s1-s4); \t\t\t# With out regeneration\n", "dT = Tm-Tm1;\n", "Wt_ = h1-h3;\n", "sr_ = 3600/Wt_;\n", "dsr = sr-sr_;\n", "n_cycle_ = 100*(h1-h3)/(h1-h4);\n", "dn = n_cycle-n_cycle_;\n", "\n", "# Results\n", "print \"Efficiency of the cycle is %.2f %%\"%n_cycle\n", "print \"Steam rate of the cycle is %.2f kg/kW h\"%sr\n", "print \"Increase in temperature due to regeneration is %.1f degree centigrade\"%dT\n", "print \"Increase in steam rate due to regeneration is %.1f kg/kW h\"%dsr\n", "print \"Increase in Efficiency of the cycle due to regeneration is %.2f %%\"%dn\n", "\n", "# note: rounding error is there because of decimal points." ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Efficiency of the cycle is 36.07 %\n", "Steam rate of the cycle is 3.85 kg/kW h\n", "Increase in temperature due to regeneration is 27.4 degree centigrade\n", "Increase in steam rate due to regeneration is 0.4 kg/kW h\n", "Increase in Efficiency of the cycle due to regeneration is 1.90 %\n" ] } ], "prompt_number": 1 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 12.6 Page No : 481" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "# Variables\n", "h1 = 3023.5; \n", "s1 = 6.7664; \n", "s2 = s1; \n", "s3 = s1; \n", "s4 = s1;\n", "t_sat_20 = 212.;\n", "t_sat_1 = 46.;\n", "\n", "# Calculation\n", "dt = t_sat_20-t_sat_1;\n", "n =3; \t\t\t# number of heaters\n", "t = dt/n;\n", "t1 = t_sat_20-t;\n", "t2 = t1-t;\n", "\n", "# 0.1 bar\n", "hf = 191.83; \n", "hfg = 2392.8; \n", "sf = 0.6493;\n", "sg = 8.1502;\n", "# At 100 degree\n", "hf100 = 419.04; \n", "hfg100 = 2257.0; \n", "sf100 = 1.3069; \n", "sg100 = 7.3549;\n", "# At 150 degree\n", "hf150 = 632.20; \n", "hfg150 = 2114.3; \n", "sf150 = 1.8418; \n", "sg150 = 6.8379;\n", "x2 = (s1-sf150)/4.9961;\n", "h2 = hf150+(x2*hfg150);\n", "x3 = (s1-sf100)/6.0480;\n", "h3 = hf100+(x3*hfg100);\n", "x4 = (s1-sf)/7.5010;\n", "h4 = hf+(x4*hfg);\n", "h5 = hf; h6 = h5;\n", "h7 = hf100; h8 = h7;\n", "h9 = 632.2; h10 = h9;\n", "m1 = (h9-h7)/(h2-h7);\n", "m2 = ((1-m1)*(h7-h6))/(h3-h6);\n", "Wt = 1*(h1-h2)+(1-m1)*(h2-h3)+(1-m1-m2)*(h3-h4);\n", "Q1 = h1-h9;\n", "Wp = 0 ; \t\t\t# Pump work is neglected\n", "n_cycle = 100*(Wt-Wp)/Q1;\n", "sr = 3600/(Wt-Wp);\n", "\n", "# Results \n", "print \"Net work per kg of stem is %.2f kJ/Kg\"%Wt\n", "print \"Cycle efficiency is %.2f %%\"%n_cycle\n", "print \"Stream rate is %.2f Kg/kW h\"%sr\n", "\n", "# rounding off error would be there." ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Net work per kg of stem is 798.64 kJ/Kg\n", "Cycle efficiency is 33.40 %\n", "Stream rate is 4.51 Kg/kW h\n" ] } ], "prompt_number": 4 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 12.7 Page No : 483" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math \n", "\n", "# Variables\n", "Ti = 2000.;\n", "Te = 450.;\n", "T0 = 300.;\n", "Q1_dot = 100e03; \t\t\t# in kW\n", "cpg = 1.1;\n", "\n", "# Calculation\n", "wg = Q1_dot/(cpg*(Ti-Te));\n", "af1 = wg*cpg*T0*((Ti/T0)-1-math.log(Ti/T0));\n", "af2 = wg*cpg*T0*((Te/T0)-1-math.log(Te/T0));\n", "afi = af1-af2;\n", "h1 = 2801; h3 = 169; h4 = 172.8; h2 = 1890.2;\n", "s1 = 6.068; s2 = s1; s3 = 0.576; s4 = s3;\n", "Wt = h1-h2;\n", "Wp = h4-h3;\n", "Q1 = h1-h4;\n", "Q2 = h2-h3;\n", "Wnet = Wt-Wp;\n", "ws = Q1_dot/2628;\n", "afu = 38*(h1-h4-T0*(s1-s3));\n", "I_dot = afi-afu;\n", "Wnet_dot = ws*Wnet;\n", "afc = ws*(h2-h3-T0*(s2-s3));\n", "n2 = 100*Wnet_dot/af1;\n", "\n", "# Results\n", "print \"The second law efficiency is %.1f %%\"%n2\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The second law efficiency is 47.3 %\n" ] } ], "prompt_number": 17 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 12.8 Page No : 485" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math \n", "\n", "# Variables\n", "h1 = 2758.; # kJ/kg\n", "h2 = 1817.; \n", "h3 = 192.\n", "h4 = 200.;\n", "cpg = 1.1\n", "\n", "# Calculation and Results\n", "Wt = h1-h2; \n", "Wp = h4-h3;\n", "Q1 = h1-h4; \n", "Wnet = Wt-Wp;\n", "n1 = Wnet/Q1;\n", "WR = Wnet/Wt;\n", "Q1_ = 100.;\n", "PO = n1*Q1_;\n", "cp = 1000.;\n", "wg = (Q1_/(833.-450));\n", "EIR = 59.3\n", "n2 = PO/EIR ;\n", "print (\"Part (a)\")\n", "print \"n1 is %.1f %%\"%(n1*100)\n", "print \"n2 is %.1f %%\"%(n2*100)\n", "print \"Work ratio is %.3f\"%WR\n", "\n", "# Part (b)\n", "h1b = 3398.; \n", "h2b = 2130.\n", "h3b = 192.; \n", "h4b = 200.;\n", "Wtb = 1268.; \n", "Wpb = 8.; \n", "Q1b = 3198.;\n", "Wt = 1268.\n", "Wp = 8.\n", "n1b = (Wt-Wp)/Q1b;\n", "WRb = (Wt-Wp)/Wtb;\n", "EIRb = 59.3;\n", "Wnetb = Q1b*n1b;\n", "n2b = 36.5/EIRb;\n", "print (\"\\nPart (b)\")\n", "print \"n1 is %.1f %%\"%(n1b*100)\n", "print \"n2 is %.1f %%\"%(n2b*100)\n", "print \"Work ratio is %.3f\"%WRb\n", "\n", "# Part (c)\n", "h1c = 3398.; \n", "h2c = 2761.; \n", "h3c = 3482.; \n", "h4c = 2522.; \n", "h5c = 192.; \n", "h6c = 200.;\n", "Wt1 = 637.; \n", "Wt2 = 960.; \n", "Wtc = Wt1+Wt2; Wpc = 8.;\n", "Wnetc = 1589.; \n", "Q1c = 3198+721.;\n", "n1c = Wnetc/Q1c;\n", "WRc = Wnetc/Wtc;\n", "POc = Q1_*n1c;\n", "EIRc = 59.3;\n", "n2c = POc/EIRc;\n", "print (\"\\nPart (c)\")\n", "print \"n1 is %.1f %%\"%(n1c*100)\n", "print \"n2 is %.1f %%\"%(n2c*100)\n", "print \"Work ratio is %.3f\"%WRc\n", "\n", "# Part (d)\n", "T3 = 318.8; T1 = 568.;\n", "n1d = 1-(T3/T1);\n", "Q1d = 2758-1316.;\n", "Wnet = Q1d*n1d;\n", "Wpd = 8.; \n", "Wtd = 641.;\n", "WRd = (Wtd-Wpd)/Wtd;\n", "POd = Q1_*0.439;\n", "EIRd = (Q1_/(833-593.))*cpg*((833.-300)-300*(math.log(833./300)));\n", "n2d = POd/94.6;\n", "print (\"\\nPart (d)\")\n", "print \"n1 is %.1f %%\"%(n1d*100)\n", "print \"n2 is %.1f %%\"%(n2d*100)\n", "print \"Work ratio is %.3f\"%WRd\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Part (a)\n", "n1 is 36.5 %\n", "n2 is 61.5 %\n", "Work ratio is 0.991\n", "\n", "Part (b)\n", "n1 is 39.4 %\n", "n2 is 61.6 %\n", "Work ratio is 0.994\n", "\n", "Part (c)\n", "n1 is 40.5 %\n", "n2 is 68.4 %\n", "Work ratio is 0.995\n", "\n", "Part (d)\n", "n1 is 43.9 %\n", "n2 is 46.4 %\n", "Work ratio is 0.988\n" ] } ], "prompt_number": 25 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 12.9 Page No : 488" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "# Variables\n", "hfg = 2202.6;\n", "Qh = 5.83;\n", "ws = Qh/hfg;\n", "eg = 0.9; \t\t\t# efficiency of generator\n", "P = 1000;\n", "Wnet = 1000/0.9;\n", "nbrake = 0.8;\n", "\n", "# Calculation\n", "h1_2s = Wnet/(ws*nbrake); \t\t\t# h1-h2s\n", "n_internal = 0.85;\n", "h12 = n_internal*h1_2s;\n", "hg = 2706.3; \n", "h2 = hg;\n", "h1 = h12+h2;\n", "h2s = h1-h1_2s;\n", "hf = 503.71;\n", "x2s = (h2s-hf)/hfg;\n", "sf = 1.5276; \n", "sfg = 5.6020;\n", "s2s = sf+(x2s*sfg);\n", "s1 = s2s;\n", "P1 = 22.5; \t\t\t# in bar from Moiller chart\n", "t1 = 360;\n", "\n", "# Results\n", "print \"Temperature of the steam is\",t1,\"degree\"\n", "print \"Pressure of the steam is \",P1,\"bar\"\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Temperature of the steam is 360 degree\n", "Pressure of the steam is 22.5 bar\n" ] } ], "prompt_number": 9 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 12.10 Page No : 489" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "# Variables\n", "h1 = 3037.3; h2 = 561+(0.96*2163.8);\n", "s2 = 1.6718+(0.96*5.3201);\n", "s3s = s2;\n", "\n", "# Calculation\n", "x3s = (s3s-0.6493)/7.5009;\n", "h3s = 191.83+(x3s*2392.8);\n", "h23 = 0.8*(h2-h3s); \t\t\t# h2-h3\n", "h3 = h2-h23;\n", "h5 = 561.47; h4 = 191.83;\n", "Qh = 3500.; \t\t\t# in kJ/s\n", "w = Qh/(h2-h5);\n", "Wt = 1500.;\n", "ws = (Wt+w*(h2-h3))/(h1-h3); \n", "ws_ = 3600.*ws ; \t\t\t# in kg/h\n", "h6 = ((ws-w)*h4+w*h5)/ws;\n", "h7 = h6;\n", "n_boiler = 0.85;\n", "CV = 44000.; \t\t\t# in kJ/kg\n", "wf = (1.1*ws_*(h1-h7))/(n_boiler*CV);\n", "\n", "# Results\n", "print \"Fuel buring rate is %.2f Kg/h\"%wf\n", "print \"Wf = %.2f tonnes/day\"%(wf*24/1000)\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Fuel buring rate is 756.64 Kg/h\n", "Wf = 18.16 tonnes/day\n" ] } ], "prompt_number": 3 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 12.11 Page No : 491" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "# Variables\n", "h1 = 3285.; \n", "h2s = 3010.\n", "h3 = 3280.; \n", "h4s = 3030.;\n", "\n", "# Calculation\n", "h4 = h3-0.83*(h3-h4s);\n", "h5s = 2225;\n", "h5 = h4-0.83*(h4-h5s);\n", "h6 = 162.7; h7 = h6;\n", "h8 = 762.81;\n", "h2 = h1-0.785*(h1-h2s);\n", "m = (h8-h7)/(h4-h7);\n", "n_cycle = ((h1-h2)+(h3-h4)+(1-m)*(h4-h5))/((h1-h8)+(h3-h2))\n", "\n", "# Results\n", "print \"Steam flow at turbine inlet is %.3f Kg/s\"%m\n", "print \"cycle efficiency is %.2f %%\"%(n_cycle*100)\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Steam flow at turbine inlet is 0.206 Kg/s\n", "cycle efficiency is 35.92 %\n" ] } ], "prompt_number": 21 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 12.12 Page No : 493" ] }, { "cell_type": "code", "collapsed": false, "input": [ "# From table and graph \n", "\n", "# Variables\n", "h1 = 2792.2;\n", "h4 = 122.96;\n", "hb = 254.88;\n", "hc = 29.98;\n", "ha = 355.98;\n", "hd = hc;\n", "h2 = 1949.27;\n", "\n", "# Calculation and Results\n", "m = (h1-h4)/(hb-hc); \t\t\t# Amount of mercury circulating\n", "Q1t = m*(ha-hd);\n", "W1t = m*(ha-hb) + (h1-h2);\n", "Nov = W1t/Q1t ;\n", "print \"Overall efficiency of the cycle %.2f %%\"%(Nov*100)\n", "\n", "S = 50000.; \t\t\t# Stem flow rate through turbine in kg/h\n", "wm = S*m;\n", "print \"Flow through the mercury turbine is %.2e Kg/h\"%wm\n", "\n", "Wt = W1t*S/3600;\n", "print \"Useful work done in binary vapour cycle is %.2e kW\"%Wt\n", "\n", "nm = 0.85; \t\t\t# Internal efficiency of mercury turbine\n", "ns = 0.87; \t\t\t# Internal efficiency of steam turbine\n", "WTm = nm*(ha-hb);\n", "hb_ = ha-WTm; \t\t\t# hb'\n", "m_ = (h1-h4)/(hb_-hc); \t\t\t# m'\n", "h1_ = 3037.3; \t\t\t# h'\n", "Q1t = m_*(ha-hd)+(h1_-h1);\n", "x2_ = (6.9160-0.4226)/(8.47-0.4226);\n", "h2_ = 121+(0.806*2432.9);\n", "WTst = ns*(h1_-h2_);\n", "WTt = m_*(ha-hb_)+WTst;\n", "Nov = WTt/Q1t;\n", "\n", "print \"Overall efficiency is %.1f %%\"%(Nov*100)\n", "\n", "# note : rounding off error." ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Overall efficiency of the cycle 52.80 %\n", "Flow through the mercury turbine is 5.93e+05 Kg/h\n", "Useful work done in binary vapour cycle is 2.84e+04 kW\n", "Overall efficiency is 46.2 %\n" ] } ], "prompt_number": 4 } ], "metadata": {} } ] }