path: root/Thermodynamics_by_K._M._Gupta/ch8.ipynb

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   "source": [
    "# Chapter 8 : Availability and Irreversibility"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "## Example 8.1 Page No : 185"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 1,
   "metadata": {
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   },
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "The available part of heat in kJ is  6784.0\n",
      "The unavailable part of heat in kJ is : 9216.0\n"
     ]
    }
   ],
   "source": [
    "\n",
    "# Variables\n",
    "Q = 16.;\t\t\t# in MJ\n",
    "Q = Q * 10**3;\t\t\t# in kJ\n",
    "T_H = 227.;\t\t\t# in °C\n",
    "T_H = T_H + 273;\t\t\t# in K\n",
    "T_L = 15.;\t\t\t# in °C\n",
    "T_L = T_L + 273;\t\t\t# in K\n",
    "\n",
    "# Calculations and Results\n",
    "del_S = Q/T_H;\t\t\t# in kJ/K\n",
    "A = Q - (T_L * del_S);\t\t\t# in kJ\n",
    "print \"The available part of heat in kJ is \",A\n",
    "\n",
    "U_P_ofHeat = T_L * del_S;\t\t\t# unavailable part of heat in kJ\n",
    "print \"The unavailable part of heat in kJ is :\",U_P_ofHeat\n"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "## Example 8.2 Page No : 185"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 1,
   "metadata": {
    "collapsed": false
   },
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "Available work is in kJ 6000.0\n",
      "Unavailable work is in kJ 6000.0\n"
     ]
    }
   ],
   "source": [
    "\n",
    "# Variables\n",
    "Q = 12000.;\t\t\t# in kJ\n",
    "T_H = 600.;\t\t\t# in K\n",
    "T_L = 300.;\t\t\t# in K\n",
    "\n",
    "# Calculations and Results\n",
    "dS = Q / T_H;\t\t\t#in kJ/K\n",
    "A = Q - (T_L * dS);\t\t\t#available work in kJ\n",
    "print \"Available work is in kJ\",A\n",
    "\n",
    "UA = T_L * dS;\t\t\t#unavailable work in kJ\n",
    "print \"Unavailable work is in kJ\",UA\n"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "## Example 8.3 Page No : 185"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 4,
   "metadata": {
    "collapsed": false
   },
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "Available energy in MJ is : 190.0\n",
      "Unavailable energy in MJ is : 110.0\n"
     ]
    }
   ],
   "source": [
    "import math \n",
    "\n",
    "# Variables\n",
    "m = 800.;\t\t\t# in kg\n",
    "C_p = 0.5;\t\t\t# in kJ/kg K\n",
    "T2 = 500.;\t\t\t# in K\n",
    "T1 = 1250.;\t\t\t# in K\n",
    "T_o = 300.;\t\t\t# in K\n",
    "\n",
    "# Calculations and Results\n",
    "del_t = T1 - T2;                    \t\t\t# in K\n",
    "Q = m * C_p * del_t;            \t    \t\t# in kJ\n",
    "dS = abs(m * C_p * math.log(T2/T1));\t\t\t# in kJ/K\n",
    "availableEnergy = Q - (T_o * dS);\t\t\t#in kJ\n",
    "print \"Available energy in MJ is :\",round(availableEnergy*10**-3)\n",
    "\n",
    "unavailableEnergy = T_o * dS;\t\t\t# UA  for unavailable energy in kJ\n",
    "print \"Unavailable energy in MJ is :\",(round(unavailableEnergy*10**-3))\n",
    "\n",
    "\n"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "## Example 8.4 Page No : 197"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 2,
   "metadata": {
    "collapsed": false
   },
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "The availablibity per kg of steam entering in kcl/kg is : 255.56\n",
      "The availablibity per kg of steam leaving in kcl/kg is : 75.50\n",
      "reversible work per kg of steam in kcl/kg is : 180.0598\n"
     ]
    }
   ],
   "source": [
    "\n",
    "# Variables\n",
    "h_i = 726.1;\n",
    "h_o = 25.03;\n",
    "T_o = 298;\t\t\t# in K\n",
    "s_i = 1.582;\n",
    "s_o = 0.087;\n",
    "h2 = 669.;\n",
    "s2 = 1.677;\n",
    "\n",
    "# Calculations and Results\n",
    "h3 = 52.17 + (0.9 * 567.7);\n",
    "s3 = 0.1748 + (0.9 * 1.7448);\n",
    "sai_i = (h_i - h_o) - (T_o * (s_i - s_o));\t\t\t# in kcl/kg\n",
    "print \"The availablibity per kg of steam entering in kcl/kg is : %.2f\"%sai_i\n",
    "\n",
    "sai_e = (0.25 * ((h2 - h_o) - (T_o * (s2 - s_o)))) + (0.75 * ((h3 - h_o) - (T_o * (s3 - s_o)))) ;\t\t\t# in kcl/kg\n",
    "print \"The availablibity per kg of steam leaving in kcl/kg is : %.2f\"%sai_e\n",
    "\n",
    "w_rev = sai_i - sai_e;\t\t\t# in kcl/kg\n",
    "print \"reversible work per kg of steam in kcl/kg is : %.4f\"%w_rev\n",
    "\n",
    "# Note: There is calculation error in evaluating the value of availability per kg of \n",
    "# steam leaving in kcl/kg . so the answer in the book is wrong and coding is right.\n"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "## Example 8.5 Page No : 198"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 1,
   "metadata": {
    "collapsed": false
   },
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "The irreversiblity in kcal/hr 43500566.0\n"
     ]
    }
   ],
   "source": [
    "\n",
    "# Variables\n",
    "T_o = 298;\t\t\t# in K\n",
    "m2 = 25000;\n",
    "s2 = 16775;\n",
    "m3 = 75000;\n",
    "s3 = 17448;\n",
    "m1 = 1000000;\n",
    "s1 = 1582;\n",
    "Q = -16;\t\t\t# in MJ\n",
    "\n",
    "# Calculations\n",
    "Q = Q * 10**3;\t\t\t# in kJ\n",
    "I = (T_o * ((m2 * s2) + (m3 * s3) - (m1 * s1))) - Q;\t\t\t# in cal/hr\n",
    "I=I*10**-3;\t\t\t# in kcal/hr\n",
    "\n",
    "# Results\n",
    "print \"The irreversiblity in kcal/hr\",I\n",
    "\n",
    "# Note: There is calculation error in evaluating the value of the irreversibility\n",
    "# in kcal/hr. so the answer in the book is wrong and coding is right.\n"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "## Example 8.6 Page No : 198"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 2,
   "metadata": {
    "collapsed": false
   },
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "The availablibity before adiabatic throttling in kcal/kg is : 267.49\n",
      "The availablibity before adiabatic throttling in kcal/kg is : 245.61\n",
      "Reversible work in kcal/kg is : 21.87\n",
      "Irreversibility per kg of steam in kcal/kg is : 21.87\n"
     ]
    }
   ],
   "source": [
    "\n",
    "# Variables\n",
    "h_i = 749.2;\n",
    "h_o = 25.03;\n",
    "T_o = 298;\t\t\t# in K\n",
    "s_i = 1.6202;\n",
    "s_o = 0.0877;\n",
    "\n",
    "# Calculations and Results\n",
    "phi_i = (h_i - h_o)- (T_o * (s_i - s_o));\t\t\t# kcal/kg\n",
    "print \"The availablibity before adiabatic throttling in kcal/kg is : %.2f\"%phi_i\n",
    "\n",
    "h_e = 749.2;\n",
    "s_e = 1.6936;\n",
    "phi_e = (h_e - h_o) - (T_o * (s_e - s_o));\t\t\t# in kcal/kg\n",
    "print \"The availablibity before adiabatic throttling in kcal/kg is : %.2f\"%phi_e\n",
    "\n",
    "Wrev = phi_i - phi_e;\t\t\t# in kcal/kg\n",
    "print \"Reversible work in kcal/kg is : %.2f\"%Wrev\n",
    "\n",
    "Wactual = 0;\n",
    "i = Wrev-Wactual;\t\t\t# in kcal/kg\n",
    "print \"Irreversibility per kg of steam in kcal/kg is : %.2f\"%i\n",
    "\n",
    "\n"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "## Example 8.7 Page No : 199"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 3,
   "metadata": {
    "collapsed": false
   },
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "Lost work in kcal/kg is 63.3567\n",
      "Irreversebility per kg of air flow in kcal/kg is : 31.467\n"
     ]
    }
   ],
   "source": [
    "import math \n",
    "\n",
    "# Variables\n",
    "# del_W = T * ds - del_Q\n",
    "T = 600;\t\t\t# in K\n",
    "p_i = 7;\t\t\t#kgf/cm**2\n",
    "p_e = 1.5;\t\t\t#kgf/cm**2\n",
    "T_o = 298;\t\t\t# in K\n",
    "\n",
    "# Calculations and Results\n",
    "R = 29.27/427;\n",
    "del_W_lost = T * ( R *math.log(p_i/p_e));\t\t\t# in kcal/kg\n",
    "print \"Lost work in kcal/kg is\",round(del_W_lost,4)\n",
    "\n",
    "i = T_o * (R * (math.log(p_i/p_e)));\t\t\t# in kcal/kg\n",
    "print \"Irreversebility per kg of air flow in kcal/kg is : %.3f\"%i\n"
   ]
  }
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