path: root/Thermal_Engineering_by_S._l._Somasundaram/Ch7.ipynb

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  {
   "cells": [
    {
     "cell_type": "heading",
     "level": 1,
     "metadata": {},
     "source": [
      "Ch-7 : Psychrometrics "
     ]
    },
    {
     "cell_type": "heading",
     "level": 2,
     "metadata": {},
     "source": [
      "Ex - 7.1 : Pg - 290"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "#initialisation of variables\n",
      "ps=0.024853 #at 21 degress \n",
      "phi=0.34 #relative humidity\n",
      "p=1.013 #pressure in bar\n",
      "#CALCULATIONS\n",
      "pv=ps*phi\n",
      "w=0.622*(pv/(p-pv))\n",
      "tdew=4.5 #at 0.00845 bar\n",
      "#RESULTS\n",
      "print 'specific humidity is %0.5f kg/kg of da'%(w)\n",
      "print 'dew point temp is %0.2f degree C'%(tdew)"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "specific humidity is 0.00523 kg/kg of da\n",
        "dew point temp is 4.50 degree C\n"
       ]
      }
     ],
     "prompt_number": 1
    },
    {
     "cell_type": "heading",
     "level": 2,
     "metadata": {},
     "source": [
      "Ex - 7.2 : Pg - 291"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "#initialisation of variables\n",
      "t1=26 #temp in degrees\n",
      "t2=32 #temp in degrees\n",
      "pvs=0.033597 #pressure in bar\n",
      "ps=0.047534 #pressure in bar\n",
      "p=1.013 #pressure in bar\n",
      "a=6.6*10**-4\n",
      "#CALCULATIONS\n",
      "pv=pvs-(p*a*(t2-t1))\n",
      "w=(0.622*pv)/(p-pv)\n",
      "phi=pv/ps\n",
      "#RESULTS\n",
      "print 'specific humidity is %0.4f kg/kg of da'%(w)\n",
      "print '\\nrelative humidity is %0.3f '%(phi)\n",
      "print 'dew point temp is 23.5 degree C' #from steam tables"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "specific humidity is 0.0187 kg/kg of da\n",
        "\n",
        "relative humidity is 0.622 \n",
        "dew point temp is 23.5 degree C\n"
       ]
      }
     ],
     "prompt_number": 2
    },
    {
     "cell_type": "heading",
     "level": 2,
     "metadata": {},
     "source": [
      "Ex - 7.3 : Pg - 291"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "#initialisation of variables\n",
      "ps=0.042415 #under 30 degrees temp in bar\n",
      "vg=32.929 #m*m*m/kg\n",
      "phi=0.3 #relative humidity\n",
      "p=1.01325 #bar\n",
      "pv=0.012725**10**2 #pressure \n",
      "rv=0.4615\n",
      "t=313 #temp in k\n",
      "pa=1.005*10**2\n",
      "ra=0.287\n",
      "#CALCULATIONS\n",
      "pv=phi*ps\n",
      "w1=0.622*(pv/(p-pv))\n",
      "rhos=1/vg\n",
      "rhov=phi*rhos\n",
      "rho=pv/(rv*t)\n",
      "pa=p-pv\n",
      "rhoa=pa*100/(ra*t)\n",
      "w2=rhov/rhoa\n",
      "ds=phi*((p-ps)/(p-pv))\n",
      "#RESULTS\n",
      "print 'partial pressure of water vapour is %0.6f bar'%(pv)\n",
      "print '\\ndensity of dry air is %0.4f kg/m*m*m'%(rhoa)\n",
      "print 'dew point temp is 10.5 degrees'\n",
      "print '\\nspecific humidity is %0.5f kg/kg of da'%(w2) #textbook answer slightly varies\n",
      "print '\\ndegree of saturation is %0.4f '%(ds)"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "partial pressure of water vapour is 0.012724 bar\n",
        "\n",
        "density of dry air is 1.1138 kg/m*m*m\n",
        "dew point temp is 10.5 degrees\n",
        "\n",
        "specific humidity is 0.00818 kg/kg of da\n",
        "\n",
        "degree of saturation is 0.2911 \n"
       ]
      }
     ],
     "prompt_number": 3
    },
    {
     "cell_type": "heading",
     "level": 2,
     "metadata": {},
     "source": [
      "Ex - 7.4 : Pg - 292"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "#initialisation of variables\n",
      "ps=0.035636 #pressure in bar\n",
      "pvw=0.018168 #pressure in bar\n",
      "p=1.01325 #pressure in bar\n",
      "a=6.6*10**-4\n",
      "w=0.00667\n",
      "td=27 #temparature in degrees\n",
      "tw=16 #temparature in degrees\n",
      "#CALCULATIONS\n",
      "pv=pvw-(p*a*(td-tw))\n",
      "w=0.622*(pv/(p-pv))\n",
      "phi=pv/ps\n",
      "h=(1.005*td+w*(2500+1.86*td))\n",
      "#RESULTS\n",
      "print 'humidity ratio is %0.5f kg/kg of da'%(w)\n",
      "print '\\nrelative humidity is %0.4f '%(phi)\n",
      "print 'dew point temparature is 8 degrees'\n",
      "print '\\nenthalphy of moist air is %0.2f kg/kg of da'%(h)"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "humidity ratio is 0.00671 kg/kg of da\n",
        "\n",
        "relative humidity is 0.3034 \n",
        "dew point temparature is 8 degrees\n",
        "\n",
        "enthalphy of moist air is 44.24 kg/kg of da\n"
       ]
      }
     ],
     "prompt_number": 4
    },
    {
     "cell_type": "heading",
     "level": 2,
     "metadata": {},
     "source": [
      "Ex - 7.5 : Pg - 293"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "#initialisation of variables\n",
      "p=1.01325 #pressure in bar\n",
      "pv=0.020 #pressure in bar at 21 degrees temp\n",
      "ws=0.0154 #kg/kg of da\n",
      "w=0.0123 #kg/kg of da\n",
      "vs=0.86 #under 21 degrees temp m*m*m/kg\n",
      "w1=0.0074\n",
      "#CALCULATIONS\n",
      "pa=p-pv\n",
      "sr=w/ws\n",
      "rho=1/vs\n",
      "avc=0.0163-w1\n",
      "#RESULTS\n",
      "print 'partial pressure of vapour and dry air are %0.2f bar and %0.5f bar'%(pv,pa)\n",
      "print 'dew point temp is 17.4 degrees'\n",
      "print 'specific humidity is 0.0123 kg/kg of da'\n",
      "print '\\nsaturation ratio is %0.3f '%(sr)\n",
      "print '\\ndensity of misture is %0.3f kg/m*m*m'%(rho)\n",
      "print '\\namount of water vapour condensed is %0.4f kg/kg of da'%(avc)"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "partial pressure of vapour and dry air are 0.02 bar and 0.99325 bar\n",
        "dew point temp is 17.4 degrees\n",
        "specific humidity is 0.0123 kg/kg of da\n",
        "\n",
        "saturation ratio is 0.799 \n",
        "\n",
        "density of misture is 1.163 kg/m*m*m\n",
        "\n",
        "amount of water vapour condensed is 0.0089 kg/kg of da\n"
       ]
      }
     ],
     "prompt_number": 5
    },
    {
     "cell_type": "heading",
     "level": 2,
     "metadata": {},
     "source": [
      "Ex - 7.6 : Pg - 294"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "#initialisation of variables\n",
      "p=1.01325 #pressure in bar\n",
      "w1=0.01468\n",
      "td=20 #temp in degrees\n",
      "tw=40 #temp in degrees\n",
      "#CALCULATIONS\n",
      "ha=(1.005*td+w1*(2500+1.86*td))\n",
      "w2=(ha-(1.005*tw))/(2500+1.86*tw)\n",
      "#RESULTS\n",
      "print 'humidity rate is %0.2f kg/kg of da'%(ha)\n",
      "print '\\nw2 is %0.5f kg/kg of da'%(w2)"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "humidity rate is 57.35 kg/kg of da\n",
        "\n",
        "w2 is 0.00666 kg/kg of da\n"
       ]
      }
     ],
     "prompt_number": 6
    },
    {
     "cell_type": "heading",
     "level": 2,
     "metadata": {},
     "source": [
      "Ex - 7.7 : Pg - 297"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "from __future__ import division\n",
      "#initialisation of variables\n",
      "ps1=0.006566 #bar pressure\n",
      "phi1=0.6 #relative humidity\n",
      "td2=21 #temp in degrees\n",
      "td1=1 #temp in degrees\n",
      "ps2=0.02486 #pressure in bar\n",
      "td3=26 #temp in degrees\n",
      "p=1.013 #pressure in bar\n",
      "#CALCULATIONS\n",
      "pv1=(phi1*ps1)\n",
      "w=0.622*(pv1/(p-pv1))\n",
      "q=(td2-td1)*(1.005+(1.86*w))\n",
      "phi2=pv1/ps2\n",
      "cbf=(td3-td2)/(td3-td1)\n",
      "cf=1-cbf\n",
      "#RESULTS\n",
      "print 'heat supplied to air is %0.2f kg/kg of da'%(q)\n",
      "print '\\nfinal relative humidity is %0.4f kg/kg of da'%(phi2)\n",
      "print '\\ncoil bypass factor is %0.2f '%(cbf)\n",
      "print '\\ncontact factor is %0.2f '%(cf)"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "heat supplied to air is 20.19 kg/kg of da\n",
        "\n",
        "final relative humidity is 0.1585 kg/kg of da\n",
        "\n",
        "coil bypass factor is 0.20 \n",
        "\n",
        "contact factor is 0.80 \n"
       ]
      }
     ],
     "prompt_number": 7
    },
    {
     "cell_type": "heading",
     "level": 2,
     "metadata": {},
     "source": [
      "Ex - 7.8 : Pg - 298"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "#initialisation of variables\n",
      "ps1=0.056216 #bar pressure\n",
      "phi1=0.2 #relative humidity\n",
      "td1=35 #temp in degrees\n",
      "p=1.01325 #pressure in bar\n",
      "td2=25 #temp in degrees\n",
      "ps2=0.03166 #bar\n",
      "#CALCULATIONS\n",
      "pv1=phi1*ps1\n",
      "w1=0.622*(pv1/(p-pv1))\n",
      "ha=(1.005*td1+w1*(2500+1.86*td1))\n",
      "w2=(ha-(1.005*td2))/(2500+1.86*td2)\n",
      "pv2=(w2*p)/(w2+0.622)\n",
      "phi2=pv2/ps2\n",
      "#RESULTS\n",
      "print 'relative humidity rate is %0.2f kg/kg of da'%(ha)\n",
      "print '\\nrelative humidity is %0.4f '%(phi2)\n",
      "print '\\namount of water to be added is %0.5f kg/kg of da'%(w2)"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "relative humidity rate is 53.08 kg/kg of da\n",
        "\n",
        "relative humidity is 0.5550 \n",
        "\n",
        "amount of water to be added is 0.01098 kg/kg of da\n"
       ]
      }
     ],
     "prompt_number": 8
    },
    {
     "cell_type": "heading",
     "level": 2,
     "metadata": {},
     "source": [
      "Ex - 7.9 : Pg - 300"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "#initialisation of variables\n",
      "ps1=0.056216 #bar pressure\n",
      "ps3=0.023366 #bar pressure\n",
      "phi1=0.6 #relative humidity\n",
      "td3=20 #temp in degress\n",
      "td1=35 #temp in degrees\n",
      "td2=12 #temp in degrees\n",
      "r=0.287\n",
      "p=1.01325 #pressure in bar\n",
      "x1=90.12 #kj/kg\n",
      "x2=34.08 #kj/kg\n",
      "x3=42.25 #kj/kg\n",
      "hf=0.4 #kj/kg\n",
      "w1=0.02142\n",
      "w2=0.00873\n",
      "#CALCULATIONS\n",
      "pv1=phi1*ps1\n",
      "w1=0.622*(pv1/(p-pv1))\n",
      "h1=(1.005*td1+w1*(2500+1.86*td1))\n",
      "pv3=phi1*ps3\n",
      "w3=0.622*(pv3/(p-pv3))\n",
      "h3=(1.005*td3+w3*(2500+1.86*td3))\n",
      "h2=(1.005*td2+0.0073*(2500+1.86*td2))\n",
      "ma=((p-pv1)*100*2.5)/(r*(td1+273))\n",
      "q1=ma*(x2-x1)+(w1-w2)*hf\n",
      "q2=(ma*(x3-x2))\n",
      "#RESULTS\n",
      "print 'mass of dry air is %0.2f kg/s'%(ma)\n",
      "print '\\ncooler load on the dehumidyfier is %0.2f kw'%(q1) # ans wrong in the book\n",
      "print '\\nheating load of the heater is %0.2f kw'%(q2)"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "mass of dry air is 2.77 kg/s\n",
        "\n",
        "cooler load on the dehumidyfier is -155.24 kw\n",
        "\n",
        "heating load of the heater is 22.63 kw\n"
       ]
      }
     ],
     "prompt_number": 9
    },
    {
     "cell_type": "heading",
     "level": 2,
     "metadata": {},
     "source": [
      "Ex - 7.10 : Pg - 302"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "#initialisation of variables\n",
      "x1=90.12 #kj/kg\n",
      "x3=42.25 #kj/kg\n",
      "ps3=0.023366 #bar pressure\n",
      "td3=35 #temp in degrees\n",
      "phi1=0.6 #relative humidity\n",
      "p=1.01325 #pressure in bar\n",
      "#CALCULATIONS\n",
      "pv3=phi1*ps3\n",
      "w3=0.622*(pv3/(p-pv3))\n",
      "h3=(1.005*td3+w3*(2500+1.86*td3))\n",
      "qs=h3-x3\n",
      "ql=x1-h3\n",
      "shf=qs/(qs+ql)\n",
      "#RESULTS\n",
      "print 'sensible heat removed is %0.2f kj/kg of da'%(qs)\n",
      "print '\\nlatent heat removed is %0.2f kj/kg of da'%(ql)\n",
      "print '\\nsensible heat factor is %0.2f '%(shf)"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "sensible heat removed is 15.31 kj/kg of da\n",
        "\n",
        "latent heat removed is 32.56 kj/kg of da\n",
        "\n",
        "sensible heat factor is 0.32 \n"
       ]
      }
     ],
     "prompt_number": 10
    },
    {
     "cell_type": "heading",
     "level": 2,
     "metadata": {},
     "source": [
      "Ex - 7.11 : Pg - 302"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "#initialisation of variables\n",
      "ps1=0.010720 #bar pressure\n",
      "phi1=0.3 #relative humidity\n",
      "td1=8 #temp in degrees\n",
      "td2=32 #temp in degrees\n",
      "td3=30 #temp in degrees\n",
      "ps3=0.042415 #bar pressure\n",
      "phi3=0.5 #relative humidity\n",
      "hf=762.6 #kj/kg\n",
      "hfg=2013.6 #kj/kg\n",
      "p=1.01325 #pressure in bar\n",
      "#CALCULATIONS\n",
      "pv1=phi1*ps1\n",
      "w1=0.622*(pv1/(p-pv1))\n",
      "h1=(1.005*td1+w1*(2500+1.86*td1))\n",
      "h2=(1.005*td2+w1*(2500+1.86*td2))\n",
      "ha=h2-h1\n",
      "pv3=phi3*ps3\n",
      "w3=0.622*(pv3/(p-pv3))\n",
      "h3=(1.005*td3+w3*(2500+1.86*td3))\n",
      "wa=w3-w1\n",
      "hw=(h3-h2)/(w3-w1)\n",
      "x=(hw-hf)/hfg\n",
      "#RESULTS\n",
      "print 'heat added is %0.2f kJ/kg of da'%(ha)\n",
      "print '\\nwater added is %0.5f kg/kg of da'%(wa)\n",
      "print 'temp os steam supplied is 179.88 degrees' #at 10 bar pressure\n",
      "print '\\nsteam required is %0.2f kj/kg of steam'%(hw)\n",
      "print '\\nquality of steam at 10 bar is %0.3f '%(x)"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "heat added is 24.21 kJ/kg of da\n",
        "\n",
        "water added is 0.01132 kg/kg of da\n",
        "temp os steam supplied is 179.88 degrees\n",
        "\n",
        "steam required is 2377.53 kj/kg of steam\n",
        "\n",
        "quality of steam at 10 bar is 0.802 \n"
       ]
      }
     ],
     "prompt_number": 11
    },
    {
     "cell_type": "heading",
     "level": 2,
     "metadata": {},
     "source": [
      "Ex - 7.12 : Pg - 305"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "#initialisation of variables\n",
      "ps1=0.023366 #bar pressure\n",
      "phi1=0.4#relative humidity\n",
      "td1=20 #temp in degrees\n",
      "m1=40 #kg/s\n",
      "ps2=0.01227 #bar pressure\n",
      "phi2=0.8#relative humidity\n",
      "td2=10 #temp in degrees\n",
      "m2=20 #kg/s\n",
      "p=1.01325 #pressure in bar\n",
      "#CALCULATIONS\n",
      "pv1=phi1*ps1\n",
      "w1=0.622*(pv1/(p-pv1))\n",
      "h1=(1.005*td1+w1*(2500+1.86*td1))\n",
      "ma1=m1/(1+w1)\n",
      "pv2=phi2*ps2\n",
      "w2=0.622*(pv2/(p-pv2))\n",
      "h2=(1.005*td2+w2*(2500+1.86*td2))\n",
      "ma2=m2/(1+w2)\n",
      "w3=((ma1*w1)+(ma2*w2))/(ma1+ma2)\n",
      "h3=((ma1*h1)+(ma2*h2))/(ma1+ma2)\n",
      "td3=((ma1*td1)+(ma2*td2))/(ma1+ma2)\n",
      "#RESULTS\n",
      "print 'specific humidity is %0.5f kJ/kg of da'%(w3)\n",
      "print '\\ntemparature of air leaving chamber is %0.2f degrees'%(td3)"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "specific humidity is 0.00589 kJ/kg of da\n",
        "\n",
        "temparature of air leaving chamber is 16.67 degrees\n"
       ]
      }
     ],
     "prompt_number": 12
    },
    {
     "cell_type": "heading",
     "level": 2,
     "metadata": {},
     "source": [
      "Ex - 7.13 : Pg - 307"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "#initialisation of variables\n",
      "ps1=0.062739 #bar pressure\n",
      "phi1=0.9 #relative humidity\n",
      "td1=37 #temp in degrees\n",
      "td3=10.7 #dew point temparature\n",
      "ps4=0.02366 #bar pressure\n",
      "phi4=0.55 #relative humidity\n",
      "td4=20 #temp in degrees\n",
      "w12=1.5 #work input in kw\n",
      "v4=50 #\n",
      "t4=37+273 #temp  in k\n",
      "Ra = 0.287\n",
      "r= 1\n",
      "w2= 1\n",
      "w3= 1\n",
      "hf3= 2\n",
      "p=1.01325 #pressure in bar\n",
      "#CALCULATIONS\n",
      "pv1=phi1*ps1\n",
      "w1=0.622*(pv1/(p-pv1))\n",
      "h1=(1.005*td1+w1*(2500+1.86*td1))\n",
      "pv4=phi4*ps4\n",
      "w4=0.622*(pv4/(p-pv4))\n",
      "h4=(1.005*td4+w4*(2500+1.86*td4))\n",
      "h3=(1.005*td3+w4*(2500+1.86*td3))\n",
      "pa4=p-pv4\n",
      "ma=(pa4*v4*100)/(Ra*t4)\n",
      "q12=(w12*60)/ma\n",
      "h2=h1+q12\n",
      "q23=((h3+(w2-w3)*hf3)-h2)\n",
      "Q23=-1*q23*ma\n",
      "q34=h4-h3\n",
      "Q34=q34*ma\n",
      "#RESULTS\n",
      "#ans in the book are wrong.\n",
      "print 'enthalpy rate 1 is %0.2f kJ/kg of da'%(h1)\n",
      "print '\\nenthalpy rate 4 is %0.2f kJ/kg of da'%(h4)\n",
      "print '\\nenthalpy rate 3 is %0.2f kJ/kg of da'%(h3) \n",
      "print '\\nmass of dry air is %0.2f kg/min'%(ma) \n",
      "print '\\nenthalpy rate 2 is %0.2f kJ/kg of da'%(h2)\n",
      "print '\\ncapacity od cooling coil q23 is %0.2f kJ/min'%(Q23)\n",
      "print '\\ncapacity od cooling coil q34 is %0.2f kJ/min'%(Q34)"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "enthalpy rate 1 is 131.48 kJ/kg of da\n",
        "\n",
        "enthalpy rate 4 is 40.63 kJ/kg of da\n",
        "\n",
        "enthalpy rate 3 is 31.14 kJ/kg of da\n",
        "\n",
        "mass of dry air is 56.21 kg/min\n",
        "\n",
        "enthalpy rate 2 is 133.08 kJ/kg of da\n",
        "\n",
        "capacity od cooling coil q23 is 5730.05 kJ/min\n",
        "\n",
        "capacity od cooling coil q34 is 533.25 kJ/min\n"
       ]
      }
     ],
     "prompt_number": 13
    },
    {
     "cell_type": "heading",
     "level": 2,
     "metadata": {},
     "source": [
      "Ex - 7.14 : Pg - 310"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "#initialisation of variables\n",
      "td3=15 #dew point temparature\n",
      "ps3=0.017039 #bar pressure\n",
      "phi3=0.55 #relative humidity\n",
      "p=1 #bar pressure\n",
      "ps4=0.029821 #bar pressure\n",
      "phi4=1 #relative humidity\n",
      "td4=24 #temp in degrees\n",
      "mw1=1000 #kg/min\n",
      "hf1=109 #kj/kg\n",
      "hf2=50.4 #kj/kg\n",
      "w4=0.01912\n",
      "w3=0.00588\n",
      "#CALCULATIONS\n",
      "pv3=phi3*ps3\n",
      "w1=0.622*(pv3/(p-pv3))\n",
      "h3=(1.005*td3+w3*(2500+1.86*td3))\n",
      "pv4=phi4*ps4\n",
      "w4=0.622*(pv4/(p-pv4))\n",
      "h4=(1.005*td4+w4*(2500+1.86*td4))\n",
      "ma=mw1*(hf1-hf2)/(h4-h3-(w4-w3)*hf2)\n",
      "x=ma*(w4-w3) #mw1-mw2\n",
      "mf=ma+x\n",
      "pl=(x/mw1)*100\n",
      "#RESULTS\n",
      "print 'mass of dry air is %0.1f kg/min'%(ma)\n",
      "print '\\nmass cooling water loss by evoporation is %0.2f kg/min '%(x)\n",
      "print '\\nmass flow of moist air is %0.2f kg/min '%(mf)\n",
      "print '\\npercentage loss by evoporation is %0.2f %%'%(pl)"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "mass of dry air is 1389.8 kg/min\n",
        "\n",
        "mass cooling water loss by evoporation is 18.40 kg/min \n",
        "\n",
        "mass flow of moist air is 1408.20 kg/min \n",
        "\n",
        "percentage loss by evoporation is 1.84 %\n"
       ]
      }
     ],
     "prompt_number": 14
    },
    {
     "cell_type": "heading",
     "level": 2,
     "metadata": {},
     "source": [
      "Ex - 7.15 : Pg - 311"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "#initialisation of variables\n",
      "td3=17 #dew point temparature\n",
      "ps3=0.019362 #bar pressure\n",
      "phi3=0.6 #relative humidity\n",
      "p=0.98 #bar pressure\n",
      "t3=290 #temp in k\n",
      "ps4=0.042415 #bar pressure\n",
      "phi4=1 #relative humidity\n",
      "td4=30 #temp in degrees\n",
      "mw2=80\n",
      "v=110 #volume\n",
      "ma=127.98\n",
      "w4=0.02814\n",
      "w3=0.007464\n",
      "r=0.287\n",
      "hf1=209.3\n",
      "#CALCULATIONS\n",
      "pv3=phi3*ps3\n",
      "w3=0.622*(pv3/(p-pv3))\n",
      "h3=(1.005*td3+w3*(2500+1.86*td3))\n",
      "pa3=p-pv3\n",
      "m=(pa3*v*100)/(r*t3)\n",
      "h2=h3+(240/ma)\n",
      "pv4=phi4*ps4\n",
      "w4=0.622*(pv4/(p-pv4))\n",
      "h4=(1.005*td4+w4*(2500+1.86*td4))\n",
      "mw1=mw2+ma*(w4-w3)\n",
      "hf2=((mw1*hf1)+(ma*h2)-(ma*h4))/mw2\n",
      "#RESULTS\n",
      "print 'mass of dry air is %0.2f kg/min'%(m)\n",
      "print '\\nenthalpy rate 3 is %0.2f kJ/kg of da'%(h3)\n",
      "print '\\nenthalpy rate 2 is %0.2f kJ/kg of da'%(h2)\n",
      "print '\\nenthalpy rate 4 is %0.2f kJ/kg of da'%(h4)\n",
      "print '\\nenthalpy rate  is %0.1f kJ/kg of da'%(hf2)\n",
      "print 'temparature of water leaving the tower is 27.1 degrees'"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "mass of dry air is 127.99 kg/min\n",
        "\n",
        "enthalpy rate 3 is 35.98 kJ/kg of da\n",
        "\n",
        "enthalpy rate 2 is 37.85 kJ/kg of da\n",
        "\n",
        "enthalpy rate 4 is 102.07 kJ/kg of da\n",
        "\n",
        "enthalpy rate  is 113.5 kJ/kg of da\n",
        "temparature of water leaving the tower is 27.1 degrees\n"
       ]
      }
     ],
     "prompt_number": 15
    },
    {
     "cell_type": "heading",
     "level": 2,
     "metadata": {},
     "source": [
      "Ex - 7.16 : Pg - 315"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "#initialisation of variables\n",
      "uw=2.5\n",
      "aw=127.82\n",
      "to=34 #temp in degrees\n",
      "tr=26 #temp in degrees\n",
      "ur=1.5\n",
      "ar=90\n",
      "ag=8.68\n",
      "clf1=100\n",
      "pvwo=0.037782\n",
      "p=1.013 #pressure in bar\n",
      "a=6.66*10**-4\n",
      "phi=0.5\n",
      "#CALCULATIONS\n",
      "shgw=uw*aw*(to-tr)\n",
      "shgr=ur*ar*(to-tr)\n",
      "sg=ag*clf1\n",
      "pvo=pvwo-(p*a*(to-tr))\n",
      "wo=0.622*(pvo/(p-pvo))\n",
      "ho=(1.005*to+wo*(2500+1.86*to))\n",
      "pvr=phi*pvo\n",
      "wr1=0.622*(pvr/(p-pvr))\n",
      "hr=(1.005*tr+wr1*(2500+1.86*tr))\n",
      "#RESULTS\n",
      "print 'recommended indoor conditions are 25.5-26.7 degrees and 50% rh and outdoor conditions are  26 degrees and 50%rh'\n",
      "print 'area of the roof is 90 m*m'\n",
      "print 'overall heat transfer coefficients are 2.5 w/m*m'\n",
      "print '\\nsensible heat gain through walls is %0.2f '%(shgw)\n",
      "print '\\nsensible heat gain through roofs is %0.2f '%(shgr)\n",
      "print '\\nsensible heat gain through windows is %0.2f '%(sg)\n",
      "print 'sensible heat per adult male is 67.5 W and latent heat is 55.7 W'\n",
      "print '\\nenthalpy rate o is %0.2f '%(ho)\n",
      "print '\\nenthalpy rate r is %0.2f '%(hr)\n",
      "print 'volume of air infiltered is 1.628 m*m*m/min'\n",
      "print 'latent heat gain is 902.4 W'\n",
      "print 'sensible heat gain is 257.2 W'\n",
      "print 'room sensible heat factor is 0.803'"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "recommended indoor conditions are 25.5-26.7 degrees and 50% rh and outdoor conditions are  26 degrees and 50%rh\n",
        "area of the roof is 90 m*m\n",
        "overall heat transfer coefficients are 2.5 w/m*m\n",
        "\n",
        "sensible heat gain through walls is 2556.40 \n",
        "\n",
        "sensible heat gain through roofs is 1080.00 \n",
        "\n",
        "sensible heat gain through windows is 868.00 \n",
        "sensible heat per adult male is 67.5 W and latent heat is 55.7 W\n",
        "\n",
        "enthalpy rate o is 86.82 \n",
        "\n",
        "enthalpy rate r is 51.88 \n",
        "volume of air infiltered is 1.628 m*m*m/min\n",
        "latent heat gain is 902.4 W\n",
        "sensible heat gain is 257.2 W\n",
        "room sensible heat factor is 0.803\n"
       ]
      }
     ],
     "prompt_number": 16
    }
   ],
   "metadata": {}
  }
 ]
}