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  "name": ""
 },
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 "worksheets": [
  {
   "cells": [
    {
     "cell_type": "heading",
     "level": 1,
     "metadata": {},
     "source": [
      "Chapter 12: Thermodynamic Property Relations"
     ]
    },
    {
     "cell_type": "heading",
     "level": 2,
     "metadata": {},
     "source": [
      "Example 12-1 ,Page No.652"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "#from Table A-17\n",
      "#cp value approximately by replacing the differentials\n",
      "h1=305.22;#in kJ/kg\n",
      "T1=305;#in K\n",
      "h2=295.17;#in kJ/kg\n",
      "T2=295;#in K\n",
      "\n",
      "#calculations\n",
      "#from the given equation we can calculate\n",
      "cp=(h1-h2)/(T1-T2);\n",
      "print'the cp of air at 300 K %f kJ/ kg - K'%round(cp,3)"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "the cp of air at 300 K 1.005000 kJ/ kg - K\n"
       ]
      }
     ],
     "prompt_number": 2
    },
    {
     "cell_type": "heading",
     "level": 2,
     "metadata": {},
     "source": [
      "Example 12-2 ,Page No.654"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "#given data\n",
      "dT=302-300;#differnce in final and intial temperatures of air in K\n",
      "dv=0.87-0.86;#differnce in final and intial volumnes of air in m^3/kg\n",
      "T=(302+300)/2;#average temp in K\n",
      "v=(0.87+0.86)/2;#average volumne in m^3/kg\n",
      "\n",
      "#constants used\n",
      "R=0.287;#in kJ/kg-K\n",
      "\n",
      "#calculations\n",
      "#using eq 12-3 by diffrentiating P= R*T/v\n",
      "dP= R*dT/v - R*T*dv/v**2;\n",
      "print'the change in the pressure of air %f kPa'%round(dP,3)"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "the change in the pressure of air -0.491000 kPa\n"
       ]
      }
     ],
     "prompt_number": 4
    },
    {
     "cell_type": "heading",
     "level": 2,
     "metadata": {},
     "source": [
      "Example 12-5 ,Page No.659"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "#given data\n",
      "T=20+273.15;#temperature of refrigerant in K\n",
      "\n",
      "#from Table A\u201311\n",
      "vf=0.0008161;#in m^3/kg\n",
      "vg=0.035969;#in m^3/kg\n",
      "\n",
      "#calculations\n",
      "#using Eq 12-22\n",
      "# hfg= T*vfg*(dP/dT)sat\n",
      "#(dP/dT)sat b/w 24 C - 16 C \n",
      "dPT=(646.18-504.58)/(24-16);#dP/dT ; values from Table A\u201311\n",
      "vfg=vg-vf;\n",
      "hfg=T*vfg*dPT;\n",
      "print'the value of the enthalpy of vaporization of refrigerant-134a %f kJ/kg'%round(hfg,2)"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "the value of the enthalpy of vaporization of refrigerant-134a 182.400000 kJ/kg\n"
       ]
      }
     ],
     "prompt_number": 5
    },
    {
     "cell_type": "heading",
     "level": 2,
     "metadata": {},
     "source": [
      "Example 12-6 ,Page No.660"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "from math import exp\n",
      "\n",
      "#given data\n",
      "T2=-50+460.0;#temperature of refrigerant-134a on R \n",
      "\n",
      "#constants\n",
      "R=0.01946;#in Btu/lbm\n",
      "\n",
      "#from Table A-11E\n",
      "T1=-40+460.0;#converted into R from F\n",
      "P1=7.432;\n",
      "hfg=97.100;\n",
      "\n",
      "#calcualation\\\n",
      "#using Equation 12\u201324\n",
      "#ln(P2/P1)= hfg/R *(1/T1 - 1/T2)\n",
      "P2=P1*exp(hfg/R *(1/T1 - 1/T2));\n",
      "print'the saturation pressure of refrigerant-134a %f psia'%round(P2,2)"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "the saturation pressure of refrigerant-134a 5.560000 psia\n"
       ]
      }
     ],
     "prompt_number": 7
    },
    {
     "cell_type": "heading",
     "level": 2,
     "metadata": {},
     "source": [
      "Example 12-11 ,Page No.373"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "from math import log\n",
      "\n",
      "#given data\n",
      "T1=220;#intial temperature in K\n",
      "P1=5;#intial pressure in MPa\n",
      "T2=300;#final temperature in K\n",
      "P2=10;#final pressure in MPa\n",
      "\n",
      "#constants used\n",
      "Ru=8.314;#on kJ/kmol- K\n",
      "\n",
      "#from Table A\u20131\n",
      "Tcr=154.8;\n",
      "Pcr=5.08;\n",
      "\n",
      "#calculations\n",
      "\n",
      "#part - a\n",
      "print('part - a');\n",
      "#by assuming ideal-gas behavior\n",
      "#from Table A\u201319\n",
      "h1=6404;\n",
      "h2=8736;\n",
      "s2=205.213;\n",
      "s1=196.171;\n",
      "h21i=h2-h1;#h2 - h1 ideal\n",
      "s21i=(s2-s1)-Ru*log(P2/P1);#s2 - s1 ideal\n",
      "print'the enthalpy change %i kJ/kmol'%round(h21i);\n",
      "print'the entropy change %f kJ/kmol-K'%round(s21i,2);\n",
      "\n",
      "#part - b\n",
      "print('part - b');\n",
      "#by accounting for the deviation from ideal-gas behavior\n",
      "TR1=T1/Tcr;\n",
      "Pr1=P1/Pcr;\n",
      "#from the generalized charts at each state\n",
      "Zh1=0.53;\n",
      "Zs1=0.25;\n",
      "TR2=T2/Tcr;\n",
      "Pr2=P2/Pcr;\n",
      "#from the generalized charts at each state\n",
      "Zh2=0.48;\n",
      "Zs2=0.20;\n",
      "h21=h21i-Ru*Tcr*(Zh2-Zh1);\n",
      "s21=s21i-Ru*(Zs2-Zs1);\n",
      "print'the enthalpy change %i in kJ/kmol'%round(h21);\n",
      "print'the entropy change %f kJ/kmol-K'%round(s21,2);\n",
      "\n"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "part - a\n",
        "the enthalpy change 2332 kJ/kmol\n",
        "the entropy change 3.280000 kJ/kmol-K\n",
        "part - b\n",
        "the enthalpy change 2396 in kJ/kmol\n",
        "the entropy change 3.690000 kJ/kmol-K\n"
       ]
      }
     ],
     "prompt_number": 1
    }
   ],
   "metadata": {}
  }
 ]
}