{
"metadata": {
"name": "",
"signature": "sha256:452c6dcc441bc91e8f34d763554249fd3e1009077055510d7afc6705627abbf4"
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"worksheets": [
{
"cells": [
{
"cell_type": "heading",
"level": 1,
"metadata": {},
"source": [
"Chapter12-ideal gas mixtures and humid air"
]
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example1-pg 338"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"import math\n",
"#calculate molecular weight of air\n",
"##initialisation of variables\n",
"x= 0.78\n",
"x1= 0.21\n",
"x2= 0.008\n",
"x3= 0.002\n",
"MN2= 28.013 ##gms\n",
"MO2= 32. ##gms\n",
"MAr= 39.948 ##gms\n",
"MH2O= 18.016 ##gms\n",
"##CALCULATIONS\n",
"M= x*MN2+x1*MO2+x2*MAr+x3*MH2O\n",
"##RESULTS\n",
"print'%s %.3f %s'% ('molecular wight of air=',M,'kg/kmol')\n"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"molecular wight of air= 28.926 kg/kmol\n"
]
}
],
"prompt_number": 1
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example2-pg341"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"import math\n",
"#calculate average value and mass\n",
"##initialisation of variables\n",
"M= 30.04 ##kg/kmol\n",
"R= 8.3143 ##J/mol K\n",
"p= 100. ##kPa\n",
"V= 0.2 ##m^3\n",
"T= 25. ##C\n",
"##CALCULATIONS\n",
"R1= R/M\n",
"m= p*V/(R1*(273.15+T))\n",
"##RESULTS\n",
"print'%s %.4f %s'% ('average value of R=',R1,'kJ/kg K')\n",
"print'%s %.3f %s'% ('mass=',m,'kg')\n"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"average value of R= 0.2768 kJ/kg K\n",
"mass= 0.242 kg\n"
]
}
],
"prompt_number": 2
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example3-pg343"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"import math\n",
"#calculate final temperature and final pressure and change in entropy\n",
"##initialisation of variables\n",
"m1= 0.5 ##kg\n",
"cv1= 0.6496 ##kJ/kg K\n",
"T1= 80. ##C\n",
"m2= 1. ##kg\n",
"cv2= 0.6299 ##kJ/kg K\n",
"T2= 150. ##C\n",
"M= 32. ##kg\n",
"M1= 44. ##kg\n",
"V1= 0.11437 ##m^3\n",
"V2= 0.1 ##m^2\n",
"R= 8.314 ##J/mol K\n",
"##CALCULATIONS\n",
"T= (m1*cv1*(273.15+T1)+m2*cv2*(273.15+T2))/(m1*cv1+m2*cv2)\n",
"p= ((m1/M)+(m2/M1))*R*T/(V1+V2)\n",
"S= m1*(cv1*math.log(T/(273.15+T1))+(R/M)*math.log((V1+V2)/V1))+m2*(cv2*math.log(T/(273.15+T2))+(R/M1)*math.log((V1+V2)/V2))\n",
"##RESULTS\n",
"print'%s %.1f %s'% ('final temperature=',T,'kPa')\n",
"print'%s %.1f %s'% ('final pressure=',p,'kPa')\n",
"print'%s %.4f %s'% ('change in entropy=',S,'kJ/K')\n"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"final temperature= 399.3 kPa\n",
"final pressure= 594.0 kPa\n",
"change in entropy= 0.2291 kJ/K\n"
]
}
],
"prompt_number": 3
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example4-pg354\n"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"import math\n",
"#calculate wet-bulb temoerature and minimum temperature and amount of water injected\n",
"##initialisation of variables\n",
"Twb= 22. ##C\n",
"Tmin= 22.3 ##C\n",
"w2= 0.0170 ##kg/kg dry air\n",
"w1= 0.0093 ##kg/kg dry air\n",
"##CALCULATIONS\n",
"m= w2-w1\n",
"##RESULTS\n",
"print'%s %.f %s'% (' wet-bulb temperature=',Twb,'C')\n",
"print'%s %.f %s'% ('minimum temperature=',Tmin,'1C')\n",
"print'%s %.4f %s'% ('amount of water injected=',m,'kg/kg dry air')\n"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
" wet-bulb temperature= 22 C\n",
"minimum temperature= 22 1C\n",
"amount of water injected= 0.0077 kg/kg dry air\n"
]
}
],
"prompt_number": 4
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example5-pg356"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"import math\n",
"#calculate state after mixing\n",
"##initialisation of variables\n",
"w3= 0.0178 ##kg/kgair\n",
"w4= 0.0172 ##kg/kgair\n",
"##CALCULATIONS\n",
"dw= w3-w4\n",
"##RESULTS\n",
"print'%s %.4f %s'% (' state after mixing=',dw,'kg/kgair')\n"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
" state after mixing= 0.0006 kg/kgair\n"
]
}
],
"prompt_number": 5
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example6-pg357"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"import math\n",
"#calculate air mass flow rate and amount of water to be added\n",
"##initialisation of variables\n",
"m= 20000. ##kg/h\n",
"T1= 42. ##C\n",
"T2= 22. ##C\n",
"J= 4.186 ##cal\n",
"h1= 54. ##kJ/kg\n",
"h2= 94.8 ##kJ/kg\n",
"w1= 0.0105 ##kg/h kg\n",
"w2= 0.0244 ##kg/h kg\n",
"##CALCULATIONS\n",
"ma= m*(T1-T2)*J/((h2-h1-J*T2*(w2-w1)))\n",
"mw= ma*(w2-w1)\n",
"m4= m-mw\n",
"##RESULTS\n",
"print'%s %.1f %s'%('air mass flow rate=',ma,'kg/hr')\n",
"print'%s %.f %s'%('amount of water to be added=',m4,'kg/hr')\n"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"air mass flow rate= 42368.5 kg/hr\n",
"amount of water to be added= 19411 kg/hr\n"
]
}
],
"prompt_number": 6
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example7-pg359"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"import math\n",
"#calculate maximum useful work\n",
"##initialisation of variables\n",
"x= 0.79\n",
"P0= 101 ##kPa\n",
"P= 20 ##Mpa\n",
"V= 0.032 ##m^3\n",
"##CALCULATIONS\n",
"p= x*P0\n",
"Wrev= P*10*10*10*V*(math.log(P/(p*math.pow(10,-3)))+((p*math.pow(10,-3))/P)-1)\n",
"##RESULTS\n",
"print'%s %.1f %s'% (' maximum useful work=',Wrev,'kJ')\n"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
" maximum useful work= 2898.0 kJ\n"
]
}
],
"prompt_number": 7
}
],
"metadata": {}
}
]
}