{ "metadata": { "name": "", "signature": "sha256:1a66a7b358047512cb72cb60b5347f9bd68c40105b1c8a4914776231ef293db4" }, "nbformat": 3, "nbformat_minor": 0, "worksheets": [ { "cells": [ { "cell_type": "heading", "level": 1, "metadata": {}, "source": [ "Chapter 11 : Real Gas" ] }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 11.1 Page No : 394" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\t\t\t\n", "# Variables\n", "P = 70.e5 \t\t\t#Pa\n", "T = 150. + 273 \t\t\t#K\n", "Z = 0.55 \t\t\t#Compressibility factor\n", "R = 8314.3/44 \t\t\t#J/kgK\n", "\t\t\t\n", "# Calculations and Results\n", "#For propane\n", "v = Z*R*T/P \t\t\t#m**3/kg\n", "print \"Specific volume for propane = %.2e m**3/kg\"%(v)\n", "\t\t\t#ideal gas\n", "v = R*T/P \t\t\t#m**3/kg\n", "print \"Specific volume for ideal gas = %2.3e m**3/kg\"%(v)\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Specific volume for propane = 6.28e-03 m**3/kg\n", "Specific volume for ideal gas = 1.142e-02 m**3/kg\n" ] } ], "prompt_number": 4 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 11.2 Page No : 396" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\t\t\t\n", "# Variables\n", "Z = 1.04 \t\t\t#Compressiblity factor\n", "pc = 3.77e6 \t\t\t#Pa \t\t\t#crticial pressure\n", "Tc = 132.5 \t\t\t#K\n", "vc = 0.0883 \t\t\t#m**3/kmol\n", "p = 10.e5 \t\t\t#Pa\n", "T = 300. \t\t\t#K\n", "\t\t\t\n", "# Calculations and Results\n", "R = 287. \t\t\t#J/kgK\n", "pR = p/pc \t\t\t#reduced pressure\n", "TR = T/Tc \t\t\t#reduced temperature\n", "v = Z*R*T/p \t\t\t#m**3/kg\n", "vR = v/vc \t\t\t#reduced volume\n", "\n", "print \"Reduced pressure = %.5f \"%(pR)\n", "print \"Reduced temperature = %.5f \"%(TR)\n", "print \"Reduced volume = %.3f \"%(vR)\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Reduced pressure = 0.26525 \n", "Reduced temperature = 2.26415 \n", "Reduced volume = 1.014 \n" ] } ], "prompt_number": 5 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 11.3 Page No : 397" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\t\t\t\n", "# Variables\n", "pR = 0.26525 \t\t\t#reduced pressure\n", "TR = 2.26415 \t\t\t#reduced temperature\n", "pc = 22.09 \t\t\t#bar \t\t\t#critical pressure of water\n", "Tc = 647.3 \t\t\t#K \t\t\t#critical temperature of water\n", "\t\t\t\n", "# Calculations and Results\n", "p = pR*pc \t\t\t#bar\n", "T = TR*Tc \t\t\t#K\n", "print \"Temperature at which steam would beahve similar to air at 10 bar and 27\u00b0C = %.1f K\"%(T)\n", "\n", "print \"Pressure at which steam would beahve similar to air at 10 bar and 27\u00b0C = %.2f bar\"%(p)\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Temperature at which steam would beahve similar to air at 10 bar and 27\u00b0C = 1465.6 K\n", "Pressure at which steam would beahve similar to air at 10 bar and 27\u00b0C = 5.86 bar\n" ] } ], "prompt_number": 3 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 11.4 Page No : 399" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\t\t\t\n", "# Variables\n", "pc = 3.77e6 \t\t\t#Pa \t\t\t#critical pressure\n", "p = 5.65e6 \t\t\t#Pa\n", "Tc = 132.5 \t\t\t#K \t\t\t#critical temperature\n", "T = 300 \t\t\t#K\n", "\n", "\t\t\t\n", "# Calculations and Results\n", "pR = p/pc \t\t\t#reduced pressure\n", "TR = T/Tc \t\t\t#reduced temperature\n", "\t\t\t#from generalized compressibilty chart\n", "Z =0.97\n", "print \"From the generalized compressiblity chart,\\\n", " at reduced pressure of %.1f and reduced temperature of %.2f, Z = %.2f\"%(pR,TR,Z)\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "From the generalized compressiblity chart, at reduced pressure of 1.5 and reduced temperature of 2.26, Z = 0.97\n" ] } ], "prompt_number": 4 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 11.5 Page No : 299" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "# Variables\n", "T =150.+273 \t\t\t#K\n", "p = 7e6 \t\t\t#Pa\n", "\n", "#Part (i)\n", "print \"Parti\"\n", "v = (8314.3/44)*T/p \t\t\t#m**3/kg\n", "print \"Specific volume for gaseous propane using ideal gas equation = %.4f m**3/kg\"%(v)\n", "\n", "#Part(ii)\n", "print \"Partii\"\n", "pc = 4.26e6 \t\t\t#Pa \t\t\t#critical pressure\n", "Tc = 370. \t\t\t#K \t\t\t#critical temperature\n", "\n", "pR = p/pc \t\t\t#reduced pressure\n", "TR = T/Tc \t\t\t#reduced temperature\n", "Z = 0.56 \t\t\t#compressibility factor\n", "print \"From the generalized compressiblity chart,\\\n", " at reduced pressure of %.1f and reduced temperature of %.2f, Z = %.2f\"%(pR,TR,Z)\n", "v = Z*v\n", "print \"Specific volume for gaseous propane using generalized compressiblity chart = %.5f m**3/kg\"%(v)\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Parti\n", "Specific volume for gaseous propane using ideal gas equation = 0.0114 m**3/kg\n", "Partii\n", "From the generalized compressiblity chart, at reduced pressure of 1.6 and reduced temperature of 1.14, Z = 0.56\n", "Specific volume for gaseous propane using generalized compressiblity chart = 0.00639 m**3/kg\n" ] } ], "prompt_number": 7 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 11.6 Page No : 404" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\t\t\t\n", "# Variables\n", "m = 5.\t\t\t#kg \t\t\t#mass of CO2\n", "T = 300. \t\t\t#K\n", "R = 8314.3/44 \t\t\t#J/kgK\n", "V = 1.5 \t\t\t#m**3\n", "\n", "#Part(i)\n", "print \"Parti\"\n", "p = m*R*T/V\n", "print \"Pressure exerted by CO2using ideal gas equation) = %.2f kPa\"%(p*.001)\n", "\n", "#Part(ii)\n", "print \"Partii\"\n", "R = 8.3143 \t\t\t#J/kmolK\n", "a = 0.3658e3 \t\t\t#kPam**6/kmol**2\n", "b = 0.0428 \t\t\t#m**3.kmol\n", "v = 44*V/m \t\t\t#m**3/kmol\n", "p = T*R/(v-b) - a/v**2\n", "print \"Pressure exerted by CO2using van der Waals equation) = %.1f kPa\"%(p)\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Parti\n", "Pressure exerted by CO2using ideal gas equation) = 188.96 kPa\n", "Partii\n", "Pressure exerted by CO2using van der Waals equation) = 187.5 kPa\n" ] } ], "prompt_number": 8 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 11.7 Page No : 406" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math \n", "\t\t\t\n", "# Variables\n", "M = 28. \t\t\t#g/mol\n", "m = 3.5\t\t\t#kg\n", "V = 0.015 \t\t\t#m**3\n", "v = V/m \t\t\t#m**3/kg\n", "T = 473. \t\t\t#K\n", "R = 8314.3/M \t\t\t#J/kgK\n", "\t\t\t\n", "# Calculations and Results\n", "\n", "#Part(i)\n", "print \"Parti\"\n", "p = m*R*T/V \t\t\t#Pa\n", "print \"Pressure using ideal gas equation of state) = %.2f MPa\"%(p*1e-6)\n", "\n", "#Part(ii)\n", "print \"Partii\"\n", "pc = 3.39e6 \t\t\t#Pa \t\t\t#critical pressure\n", "Tc = 126.2 \t\t\t#K \t\t\t#critical temperature\n", "vc = 0.0899 \t\t\t#m**3/kmol \t\t\t#critical volume\n", "\n", "TR = T/Tc \t\t\t#reduced temperature\n", "vR = v/(R*Tc/pc) \t\t\t#reduced volume\n", "Z = 1.1 \t\t\t#Compressibility factor\n", "print \"From the generalized compressiblity chart, \\\n", " at reduced volume of %.4f and reduced temperature of %.2f, Z = %.2f\"%(vR,TR,Z)\n", "p = Z*R*T/v \t\t\t#Pa\n", "print \"Pressure using generalised compressibility chart) = %.3f MPa\"%(p*1e-6)\n", "\n", "#Part(iii)\n", "print \"Partiii\"\n", "a = 0.1366e6 \t\t\t#Pam**5/kmol**2\n", "b = 0.0386 \t\t\t#m**3/kmol\n", "p = (8314.3*T/(v*M - b)) - a/(v*M)**2\n", "print \"Pressure using van der Waals equation) = %.2f MPa\"%(p*1e-6)\n", "\n", "#Part(iv)\n", "print \"Partiv\"\n", "a = (0.427*(R*M)**2*Tc**2.5/pc)\n", "b = 0.0866*(R*M*Tc/pc)\n", "\n", "p = (R*M*T/(v*M-b))-(a/(((v*M)**2 + v*M*b)*(T**0.5)))\n", "print \"Pressure using Redlich-Kwong equation of state) = %.2f MPa\"%(p*1e-6)\n", "\n", "\n", "#Part(v)\n", "print \"Partv\"\n", "A0 = 136.2315\n", "a = 0.02617\n", "B0 = 0.05046\n", "b = -0.00691\n", "c = 42000\n", "\n", "A = A0*(1 - a/(v*M))\n", "B = B0*(1 - b/(v*M))\n", "eps = c/(T**3 * v*M)\n", "p = ((8314.3)*T*(1-eps)*(v*M+B))/(v*M)**2 - 1e3*A/(v*M)**2\n", "print \"Pressure using ideal gas equation of state) = %.2f MPa\"%(p*1e-6)\n", "\n", "\t\t\t#---Note--- \t\t\t\n", "# Calculations and Results to Part(iv) in the textbook is 40.58 MPa which is wrong. \n", "# The correct solution (38.13 MPa) is computed here.\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Parti\n", "Pressure using ideal gas equation of state) = 32.77 MPa\n", "Partii\n", "From the generalized compressiblity chart, at reduced volume of 0.3877 and reduced temperature of 3.75, Z = 1.10\n", "Pressure using generalised compressibility chart) = 36.049 MPa\n", "Partiii\n", "Pressure using van der Waals equation) = 38.83 MPa\n", "Partiv\n", "Pressure using Redlich-Kwong equation of state) = 38.13 MPa\n", "Partv\n", "Pressure using ideal gas equation of state) = 39.79 MPa\n" ] } ], "prompt_number": 1 } ], "metadata": {} } ] }