{ "metadata": { "name": "", "signature": "sha256:bcb2b5536fdc9000213789c2755747f3e4bd3724ffe95c35320fbc2314325dca" }, "nbformat": 3, "nbformat_minor": 0, "worksheets": [ { "cells": [ { "cell_type": "heading", "level": 1, "metadata": {}, "source": [ "Chapter 11 :\n", "Chemical Thermodynamics and\n", "Equilibrium" ] }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 11.1 pg : 287" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\t\t\t\n", "# Variables\n", "x = 1.5\n", "P = 14.696 \t \t\t#psia\n", "m = 28.96\n", "\t\t\t\n", "# Calculations\n", "mf = 114. \t\t\t# lbm/mol fuel\n", "ma = x*12.5*(1+3.76)*m\n", "AF = ma/mf\n", "n1 = 8.\n", "n2 = 9.\n", "n3 = (x-1)*12.5 \n", "n4 = x*3.76*12.5\n", "np = n1+n2+n3+n4\n", "x1 = n1/np\n", "x2 = n2/np\n", "x3 = n3/np\n", "x4 = n4/np\n", "ph = x2*P\n", "Td = 113.5 \t\t\t#F\n", "\t\t\t\n", "# Results\n", "print \"Air fuel ratio = %.1f lbm air/lbm fuel\"%(AF)\n", "print \" Mole fraction of CO2 = %.2f percent\"%(x1*100)\n", "print \" Mole fraction of H2O = %.2f percent\"%(x2*100)\n", "print \" Mole fraction of O2 = %.2f percent\"%(x3*100)\n", "print \" Mole fraction of N2 = %.2f percent\"%(x4*100)\n", "print (\"From tables of saturation pressure\")\n", "print \"Dew point = %.1f F\"%(Td)\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Air fuel ratio = 22.7 lbm air/lbm fuel\n", " Mole fraction of CO2 = 8.53 percent\n", " Mole fraction of H2O = 9.60 percent\n", " Mole fraction of O2 = 6.67 percent\n", " Mole fraction of N2 = 75.20 percent\n", "From tables of saturation pressure\n", "Dew point = 113.5 F\n" ] } ], "prompt_number": 4 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 11.2 pg : 290" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\t\t\t\n", "# Variables\n", "x1 = 9.\n", "x2 = 1.2\n", "x3 = 1.5\n", "x4 = 88.3\n", "\t\t\t\n", "# Calculations\n", "a = x1+x2\n", "b = 2*a\n", "xO = (2*x1 + x2+ 2*x3 + b)/2\n", "xN = x4/3.76\n", "ratio = xO/a\n", "percent = ratio/2 *100\n", "\t\t\t\n", "# Results\n", "print \"Percent theoretical air = %.1f percent\"%(percent)\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Percent theoretical air = 104.4 percent\n" ] } ], "prompt_number": 5 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 11.3 pg : 291" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\t\t\t\n", "# Variables\n", "T = 440. \t\t\t#F\n", "\t\t\t\n", "# Calculations\n", "h1 = -169290\n", "h2 = 7597.6\n", "h3 = 4030.2\n", "ht = h1+h2-h3\n", "\t\t\t\n", "# Results\n", "print \"Molal enthalpy of CO2 = %d Btu/lbm mole\"%(ht)\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Molal enthalpy of CO2 = -165722 Btu/lbm mole\n" ] } ], "prompt_number": 6 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 11.4 pg : 291" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\t\t\t\n", "# Variables\n", "T = 77. \t \t\t#F\n", "\t\t\t\n", "# Calculations\n", "Hr = -36420. \t\t\t#B\n", "hc = -169290. \t\t\t#B/lb mol\n", "hh = -122970. \t\t\t#B/lb mol\n", "Hp = 2*hc+3*hh\n", "Q = Hp-Hr\n", "\t\t\t\n", "# Results\n", "print \"Heat transfer = %d B/mol fuel\"%(Q)\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Heat transfer = -671070 B/mol fuel\n" ] } ], "prompt_number": 7 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 11.5 pg : 294" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\t\t\t\n", "# Variables\n", "T2 = 440. \t\t\t#F\n", "T1 = 77. \t\t\t#F\n", "Mch4 = 16.\n", "Mw = 18.\n", "\t\t\t\n", "# Calculations\n", "h77 = 3725.1\n", "ht = 6337.9\n", "ht2 = 7597.6\n", "h772 = 4030.2\n", "hwt = 1260.3\n", "h77w = 45.02\n", "hr77 = -383040. \t\t\t#B/lbm mol\n", "dHR = 1*Mch4*0.532*(T1-T2) + 2*(h77-ht)\n", "dHp = 1*(ht2-h772) + 2*Mw*(hwt - h77w)\n", "hrp = dHp+hr77+dHR\n", "\t\t\t\n", "# Results\n", "print \"Enthalpy of combustion of gaseous methane = %d B/lbm mol fuel\"%(hrp)\n", "\n", "#The calculation in textbook is wrong Please check it using a calculator.\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Enthalpy of combustion of gaseous methane = -344037 B/lbm mol fuel\n" ] } ], "prompt_number": 9 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 11.6 pg : 295" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\t\t\t\n", "# Variables\n", "Hr = -107530. \t\t\t#B/mol fuel\n", "print (\"By iteration of temperatures, T = 2700 R\")\n", "T = 2700. \t\t\t#R\n", "\t\t\t\n", "# Results\n", "print \"Adiabatic flame temperature = %d R\"%(T)\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "By iteration of temperatures, T = 2700 R\n", "Adiabatic flame temperature = 2700 R\n" ] } ], "prompt_number": 10 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 11.7 pg : 306" ] }, { "cell_type": "code", "collapsed": false, "input": [ "from numpy import poly1d,roots\n", "\n", "# Variables\n", "import math \n", "Kp = 0.668\n", "y = Kp**2\n", "\t\t\t\n", "# Calculations\n", "x = poly1d(0)\n", "vec = roots([y,2,-y,-2,0]) #x**3 + y*x**3 + 2*y*x**2 -y*x -2*y)\n", "\n", "eps = vec[0]\n", "x1 = (1-eps)/(1+ eps/2)\n", "x2 = eps/(1+eps/2)\n", "x3 = eps/2/(1+ eps/2)\n", "\t\t\t\n", "# Results\n", "print \"degree of reaction = %.3f \"%(eps)\n", "print \" Equilibrium concentration of CO2 = %.3f \"%(x1)\n", "print \" Equilibrium concentration of CO = %.3f \"%(x2)\n", "print \" Equilibrium concentration of O2 = %.3f \"%(x3)\n", "\n", "#the answers are different due to approximation in textbook\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "degree of reaction = -4.482 \n", " Equilibrium concentration of CO2 = -4.417 \n", " Equilibrium concentration of CO = 3.612 \n", " Equilibrium concentration of O2 = 1.806 \n" ] } ], "prompt_number": 1 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 11.8 pg : 307" ] }, { "cell_type": "code", "collapsed": false, "input": [ "from numpy import roots\n", "\n", "# Variables\n", "Kp = 15.63\n", "y = Kp\n", "\t\t\t\n", "# Calculations\n", "vec = roots([y+1,0,-y])#x**2 + y*x**2 - y)\n", "eps = vec[0]\n", "x1 = (1-eps)/(1+eps)\n", "x2 = eps/(1+eps)\n", "x3 = eps/(1+eps)\n", "\t\t\t\n", "# Results\n", "print \" Equilibrium concentration of Cs = %.4f \"%(x1)\n", "print \" Equilibrium concentration of Cs+ = %.4f \"%(x2)\n", "print \" Equilibrium concentration of e- = %.4f \"%(x3)\n", "\n", "#the answers are a bit different due to approximation in textbook\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ " Equilibrium concentration of Cs = 0.0155 \n", " Equilibrium concentration of Cs+ = 0.4922 \n", " Equilibrium concentration of e- = 0.4922 \n" ] } ], "prompt_number": 2 } ], "metadata": {} } ] }