{ "metadata": { "name": "", "signature": "sha256:6d140b39334d6849c83f7e8a1c4ba8d4542274675b397290c6ad476b147314bb" }, "nbformat": 3, "nbformat_minor": 0, "worksheets": [ { "cells": [ { "cell_type": "heading", "level": 1, "metadata": {}, "source": [ "Chapter9-Applications of the second law of thermodynamics" ] }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example1-pg 152" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math\n", "#calculate final temperatures and total entropy\n", "##changeinitialisation of variables\n", "p1= 3.##changeMpa\n", "p2= 0.2 ##changeMpa\n", "V1= 0.6 ##changem^3\n", "V2= 1.##changem^3\n", "M= 28. ##changegms\n", "R= 8.314 ##changeJ/mol K\n", "T= 400. ##changeC\n", "T1= 150. ##changeC\n", "k= 1.4\n", "p3= 1.25 ##changeMpa\n", "##changeCALCULATIONS\n", "m1= p1*V1*10.*10.*10.*M/(R*(273.15+T))\n", "m2= p2*V2*10.*10.*10.*M/(R*(273.15+T1))\n", "p4= (p1*V1+p2*V2)/(V1+V2)\n", "T2= (math.pow(p4/p1,k-1.)/k)*(273.15+T)\n", "m3= p3*V1*M*10.*10.*10./(R*T2)\n", "dm= m1-m3\n", "m4= m2+dm\n", "T4= p3*10.*10.*10.*V2/((R/M)*m4)\n", "S= (R/M)*(m2*((k/(k-1.))*math.log(T4/(273.15+T1))-math.log(p3/p2))+dm*((k/(k-1.))*math.log(T4/(273.15+T))-math.log(p3/p1)))\n", "##changeRESULTS\n", "print'%s %.1f %s'%('final temperature =',T2,'K')\n", "print'%s %.1f %s'%('final temperature =',T4,'K')\n", "print'%s %.4f %s'%('Total entropy =',S,'KJ/K')\n", "#ans is not matching because round of error " ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "final temperature = 338.8 K\n", "final temperature = 1340.2 K\n", "Total entropy = 2.5525 KJ/K\n" ] } ], "prompt_number": 2 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example2-pg203" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math\n", "#calculate work of the pump\n", "##initialisation of variables\n", "m= 10000 ##kg/h\n", "P= 2.5 ##Mpa\n", "P1= 100 ##kPa\n", "v= 0.001003 ##m^3\n", "##CALCULATIONS\n", "W= -m*v*(P*10*10*10-P1)/3600\n", "##RESULTS\n", "print'%s %.3f %s'%(' work of the pump =',W,'kW')\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ " work of the pump = -6.687 kW\n" ] } ], "prompt_number": 9 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example3-pg 205" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math\n", "##initialisation of variables\n", "m= 4. ##kg/s\n", "R= 8.314 ##J/mol K\n", "M= 29. ##gms\n", "k= 1.4\n", "T1= 27. ##C\n", "p2= 1800. ##kPa\n", "p1= 105. ##kPa\n", "n= 1.22\n", "cp= 1.4 ##Jmol K\n", "##CALCULATIONS\n", "T2= (273.15+T1)*(p2/p1)**((n-1)/n)\n", "W= m*k*(R/M)*((273.15+T1)/(k-1))*(1-(p2/p1)**((k-1)/k))\n", "Q= -m*R*(273.15+T1)*math.log(p2/p1)/M\n", "W1= m*(R/M)*n*((273.15+T1)/(n-1))*(1-(p2/p1)**((n-1)/n))\n", "Q1= m*(R/M)*(n-k)*(T2-T1-273.15)/((n-1)*(k-1))\n", "T3= (273.15+T1)*(p2/p1)**((k-1)/(2*k))\n", "Q2= m*cp*(R/M)*(T1+273.15-T3)/(k-1)\n", "##RESULTS\n", "print'%s %.1f %s'%('heat removed in adiabatic compression =',W,'kW')\n", "print'%s %.1f %s'%('heat removed in isothermal compression =',Q,'kW')\n", "print'%s %.1f %s'%('heat removed in polytropic process =',Q1,'kW')\n", "print'%s %.2f %s'%('heat removed in adiabatic compression in two stages =',Q2,'kW')\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "heat removed in adiabatic compression = -1508.5 kW\n", "heat removed in isothermal compression = -978.1 kW\n", "heat removed in polytropic process = -471.2 kW\n", "heat removed in adiabatic compression in two stages = -603.21 kW\n" ] } ], "prompt_number": 8 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example4-pg 208" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math\n", "#calculate enthalpy and entropy\n", "##initialisation of variables\n", "h1= 3422.25 ##kJ/kg\n", "m= 8. ##kg/s\n", "s2= 7.3755 ##kJ/kg K\n", "s1= 6.8803 ##kJ/kg K\n", "e= 0.8\n", "h2s= 2496.8 ##kJ/kg\n", "##CALCULATIONS\n", "h2= h1+e*(h2s-h1)\n", "W= m*(h1-h2)\n", "S= s2-s1\n", "##RESULTS\n", "print'%s %.1f %s'%('Enthalpy =',W,'kW')\n", "print'%s %.4f %s'% ('Entropy =',S,'kJ/kg K')\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Enthalpy = 5922.9 kW\n", "Entropy = 0.4952 kJ/kg K\n" ] } ], "prompt_number": 7 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example5-pg209" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math\n", "calculate volume flow rate into composser and volume flow rate out composser and heat and work \n", "##initialisation of variables\n", "m= 0.2 ##kg/s\n", "v1= 1.0803 ##m^3/kg\n", "T= 200 ##C\n", "s2= 5.8041 ##kJ/kg K\n", "s1= 7.5066 ##kJ/kg K\n", "h1= 2328.1 ##kJ/kg\n", "h2= 2654.4 ##kJ/kg\n", "##CALCULATIONS\n", "V1= m*v1\n", "V2= 0.1*V1\n", "Q= m*(273.15+T)*(s2-s1)\n", "W= Q-m*(h1-h2)\n", "##RESULTS\n", "print'%s %.4f %s'%('volume flow rate into composser =',V1,'m^3')\n", "print'%s %.4f %s'%('volume flow rate out of composser =',V2,'m^3')\n", "print'%s %.1f %s'%('Heat =',Q,'kJ')\n", "print'%s %.1f %s'%(' Work =',W,'kJ')\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "volume flow rate into composser = 0.2161 m^3\n", "volume flow rate out of composser = 0.0216 m^3\n", "Heat = -161.1 kJ\n", " Work = -95.8 kJ\n" ] } ], "prompt_number": 6 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example6-pg211" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math\n", "#calculate volume flow rate out and into the composser and work and heat\n", "##initialisation of variables\n", "m1= 0.2 ##kg/s\n", "v1= 1.0803 ##m^3/kg\n", "P= 200 ##kPa\n", "T= 200 ##C\n", "s1= 5.8041 ##kJ.kg K\n", "s2= 7.5066 ##kJ/kg K\n", "h1= 2870.5 ##kJ/kg\n", "h2= 2495.9 ##kJ/kg\n", "##CALCULATIONS\n", "V1= m1*v1\n", "V2= 0.1*V1\n", "Q= m1*(273.15+T)*(s1-s2)\n", "W= m1*((h1-h2)-(273.15+T)*(s2-s1))\n", "##RESULTS\n", "print'%s %.4f %s'% ('volume flow rate into composser =',V1,'m^3/s')\n", "print'%s %.4f %s'%('volume flow rate out of composser =',V2,'m^3/s') \n", "print'%s %.1f %s'%('Work =',W,'kW')\n", "print'%s %.1f %s'%('Heat =',Q,'kW')\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "volume flow rate into composser = 0.2161 m^3/s\n", "volume flow rate out of composser = 0.0216 m^3/s\n", "Work = -86.2 kW\n", "Heat = -161.1 kW\n" ] } ], "prompt_number": 5 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example7-pg213" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math\n", "#calculate rate of transfer\n", "##initialisation of variables\n", "e= 0.82\n", "m= 5 ##kg/s\n", "T3= 450 ##C\n", "T1= 200 ##C\n", "##CALCULATIONS\n", "Q= e*m*1.0035*(T3-T1)\n", "##RESULTS\n", "print'%s %.1f %s'%('rate of transfer =',Q,'kW')\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "rate of transfer = 1028.6 kW\n" ] } ], "prompt_number": 4 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example8-pg 211" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math\n", "#calculate heat at given enthalpy\n", "##initialisation of variables\n", "h1= 174.076 ##kJ/kg\n", "h3= 74.527 ##kJ/kg\n", "h4= 8.854 ##kJ/kg\n", "m= 0.8 ##kg\n", "e= 0.85\n", "##CALCULATIONS\n", "h2= h1+h3-h4\n", "Q= m*(h2-h1-23)\n", "Q1= e*Q\n", "##RESULTS\n", "print'%s %.2f %s'%('Heat =',Q,'kW')\n", "print'%s %.2f %s'%('Heat =',Q1,'kW')\n", "#round of error\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Heat = 34.14 kW\n", "Heat = 29.02 kW\n" ] } ], "prompt_number": 3 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example9-pg 214" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math\n", "#calculate enthalpy and entropy change\n", "##initialisation of variables\n", "W= 2000. ##kW\n", "m= 2. ##kg/s\n", "h1= 3023.5 ##kJ/kg\n", "s2= 5.6106 ##kJ/kg K\n", "s1= 6.7664 ##kJ/kg K\n", "##CALCULATIONS\n", "h2= h1-(W/m)\n", "S=s2-s1\n", "##RESULTS\n", "print'%s %.1f %s'% ('enthalpy =',h2,'kJ/kg')\n", "print'%s %.4f %s'%('entropy change =',S,'kJ/kg K')\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "enthalpy = 2023.5 kJ/kg\n", "entropy change = -1.1558 kJ/kg K\n" ] } ], "prompt_number": 2 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example10-pg 215" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math\n", "#calculate enthalpy and entropy change\n", "##initialisation of variables\n", "m1= 1 ##kg\n", "h1= 2967.6 ##kJ/kg\n", "h2= 83.96 ##kJ/kg\n", "m2= 10\n", "s1= 7.5166 ##kJ/kg K\n", "s2= 0.2966 ##kJ/kg K\n", "s3= 1.1654 ##kJ/kg K\n", "##CALCULATIONS\n", "h3= (m1*h1+m2*h2)/(m1+m2)\n", "S= -m1*s1-m2*s2+(m1+m2)*s3\n", "##RESULTS\n", "print'%s %.1f %s'% ('enthalpy =',h3,'kJ/kg')\n", "print'%s %.4f %s'%('entropy change =',S,'kJ/kg K')\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "enthalpy = 346.1 kJ/kg\n", "entropy change = 2.3368 kJ/kg K\n" ] } ], "prompt_number": 1 } ], "metadata": {} } ] }