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diff --git a/Thermodynamics_An_Engineering_Approach/Chapter2.ipynb b/Thermodynamics_An_Engineering_Approach/Chapter2.ipynb new file mode 100755 index 00000000..db573fc6 --- /dev/null +++ b/Thermodynamics_An_Engineering_Approach/Chapter2.ipynb @@ -0,0 +1,588 @@ +{
+ "metadata": {
+ "name": ""
+ },
+ "nbformat": 3,
+ "nbformat_minor": 0,
+ "worksheets": [
+ {
+ "cells": [
+ {
+ "cell_type": "heading",
+ "level": 1,
+ "metadata": {},
+ "source": [
+ "Chapter 2: Energy Conversion and General Energy Analysis"
+ ]
+ },
+ {
+ "cell_type": "heading",
+ "level": 2,
+ "metadata": {},
+ "source": [
+ " Example 2-1 ,Page No.57"
+ ]
+ },
+ {
+ "cell_type": "code",
+ "collapsed": false,
+ "input": [
+ "#there is a 0.00490% error as the answer in textbook is expressed in multiple of 10\n",
+ "#Constants used\n",
+ "Hu=6.73*10**10;#Energy liberated by 1 kg of uranium\n",
+ "\n",
+ "# Given values\n",
+ "p=0.75;# assuming the avg density of gasoline in kg/L\n",
+ "V=5;# consumption per day of gasoline in L\n",
+ "Hv=44000; #heat value in kJ/kg\n",
+ "mu=0.1;# mass of uranium used\n",
+ "\n",
+ "#Calculation\n",
+ "mgas=p*V;#mass of gasoline required per day\n",
+ "Egas=mgas*Hv;\n",
+ "Eu=mu*Hu;\n",
+ "d=Eu/Egas;\n",
+ "print'%i number of days the car can run with uranium' %round(d,0)\n",
+ "print'equivalent to %i years' %round(d/365,0)\n"
+ ],
+ "language": "python",
+ "metadata": {},
+ "outputs": [
+ {
+ "output_type": "stream",
+ "stream": "stdout",
+ "text": [
+ "40788 number of days the car can run with uranium\n",
+ "equivalent to 112 years\n"
+ ]
+ }
+ ],
+ "prompt_number": 2
+ },
+ {
+ "cell_type": "heading",
+ "level": 2,
+ "metadata": {},
+ "source": [
+ "Example 2-2 ,Page No.59"
+ ]
+ },
+ {
+ "cell_type": "code",
+ "collapsed": false,
+ "input": [
+ "# Given values\n",
+ "v=8.5;# wind speed in m/s\n",
+ "m=10;# given mass for part - b \n",
+ "mf=1154;# given flowrate for part - c\n",
+ "\n",
+ "#Calculations\n",
+ "e=(v**2)/2;\n",
+ "print'wind energy per unit mass %f J/kg' %round(e,1);\n",
+ "E=m*e;\n",
+ "print'wind energy for 10 kg mass %i J' %E;\n",
+ "E=mf*e/1000;\n",
+ "print'wind energy for mass flow rate of 1154kg/s %f kW'%round(E,1)\n"
+ ],
+ "language": "python",
+ "metadata": {},
+ "outputs": [
+ {
+ "output_type": "stream",
+ "stream": "stdout",
+ "text": [
+ "wind energy per unit mass 36.100000 J/kg\n",
+ "wind energy for 10 kg mass 361 J\n",
+ "wind energy for mass flow rate of 1154kg/s 41.700000 kW\n"
+ ]
+ }
+ ],
+ "prompt_number": 2
+ },
+ {
+ "cell_type": "heading",
+ "level": 2,
+ "metadata": {},
+ "source": [
+ "Example 2-7 ,Page No.67"
+ ]
+ },
+ {
+ "cell_type": "code",
+ "collapsed": false,
+ "input": [
+ "import math\n",
+ "\n",
+ "# Given values\n",
+ "T=200;# applied torque in N\n",
+ "n=4000;# shaft rotation rate in revolutions per minute\n",
+ "\n",
+ "#Calculation\n",
+ "Wsh=(2*math.pi*n*T)/1000/60;#factor of 1000 to convert to kW and 60 to convert to sec\n",
+ "print'Power transmitted %f kW'%round(Wsh,1)"
+ ],
+ "language": "python",
+ "metadata": {},
+ "outputs": [
+ {
+ "output_type": "stream",
+ "stream": "stdout",
+ "text": [
+ "Power transmitted 83.800000 kW\n"
+ ]
+ }
+ ],
+ "prompt_number": 3
+ },
+ {
+ "cell_type": "heading",
+ "level": 2,
+ "metadata": {},
+ "source": [
+ "Example 2-8 ,Page No.69"
+ ]
+ },
+ {
+ "cell_type": "code",
+ "collapsed": false,
+ "input": [
+ "import math\n",
+ "\n",
+ "#Constants used\n",
+ "g=9.81;#acceleration due to gravity in m/s^2;\n",
+ "\n",
+ "#Given values\n",
+ "m=1200;#mass of car in kg\n",
+ "V=90/3.6;#velocity ; converting km/h into m/s\n",
+ "d=30*math.pi/180;#angle of slope ; converting into radians\n",
+ "\n",
+ "#Calculation\n",
+ "Vver=V*math.sin(d);#velocity in vertical direction\n",
+ "Wg=m*g*Vver/1000;\n",
+ "print'the addtional power %i kW'%Wg"
+ ],
+ "language": "python",
+ "metadata": {},
+ "outputs": [
+ {
+ "output_type": "stream",
+ "stream": "stdout",
+ "text": [
+ "the addtional power 147 kW\n"
+ ]
+ }
+ ],
+ "prompt_number": 4
+ },
+ {
+ "cell_type": "heading",
+ "level": 2,
+ "metadata": {},
+ "source": [
+ "Example 2-9 ,Page No.69"
+ ]
+ },
+ {
+ "cell_type": "code",
+ "collapsed": false,
+ "input": [
+ "#Given values\n",
+ "m=900;#mass of car in kg\n",
+ "v1=0;# intial velocity\n",
+ "v2=80/3.6;# final velocity; converting km/h into m/s\n",
+ "t=20;# time taken1\n",
+ "\n",
+ "#Calculation\n",
+ "Wa=m*(v2**2-v1**2)/2/1000;\n",
+ "Wavg=Wa/t;\n",
+ "print'the average power %f kW'%round(Wavg,1)\n"
+ ],
+ "language": "python",
+ "metadata": {},
+ "outputs": [
+ {
+ "output_type": "stream",
+ "stream": "stdout",
+ "text": [
+ "the average power 11.100000 kW\n"
+ ]
+ }
+ ],
+ "prompt_number": 21
+ },
+ {
+ "cell_type": "heading",
+ "level": 2,
+ "metadata": {},
+ "source": [
+ "Example 2-10 ,Page No.74"
+ ]
+ },
+ {
+ "cell_type": "code",
+ "collapsed": false,
+ "input": [
+ "#Given values\n",
+ "Win=100;# work done in the process in kJ\n",
+ "Qout=500;# heat lost in kJ\n",
+ "U1=800;# internal energy of the fluid in kJ\n",
+ "\n",
+ "#Calculations\n",
+ "# Win - Qout = U2- U1 i.e change in internal energy \n",
+ "U2=U1-Qout+Win;\n",
+ "print'final internal of the system %i kJ'%U2\n"
+ ],
+ "language": "python",
+ "metadata": {},
+ "outputs": [
+ {
+ "output_type": "stream",
+ "stream": "stdout",
+ "text": [
+ "final internal of the system 400 kJ\n"
+ ]
+ }
+ ],
+ "prompt_number": 7
+ },
+ {
+ "cell_type": "heading",
+ "level": 2,
+ "metadata": {},
+ "source": [
+ "Example 2-11 ,Page No.75"
+ ]
+ },
+ {
+ "cell_type": "code",
+ "collapsed": false,
+ "input": [
+ "import math\n",
+ "\n",
+ "#given values\n",
+ "Win=20;# power consumption in W\n",
+ "mair=0.25;# rate of air discharge in kg/sec\n",
+ "\n",
+ "#calculation\n",
+ "v=math.sqrt(Win/2/mair)#Win = 1/2*m*v^2\n",
+ "if v >=8:\n",
+ " print('True');\n",
+ "else:\n",
+ " print('False')\n"
+ ],
+ "language": "python",
+ "metadata": {},
+ "outputs": [
+ {
+ "output_type": "stream",
+ "stream": "stdout",
+ "text": [
+ "False\n"
+ ]
+ }
+ ],
+ "prompt_number": 8
+ },
+ {
+ "cell_type": "heading",
+ "level": 2,
+ "metadata": {},
+ "source": [
+ "Example 2-12 ,Page No.76"
+ ]
+ },
+ {
+ "cell_type": "code",
+ "collapsed": false,
+ "input": [
+ "#Given values\n",
+ "Win=200.0;#Power of fan in W\n",
+ "U=6.0;#Overall heat transfer coefficient in W/m^2 C\n",
+ "A=30;#Surface area in m^2\n",
+ "To=25;#Outdoor temperature in C\n",
+ "\n",
+ "#Calculations\n",
+ "Ti= (Win/U/A)+To;# Win = Qout = U*A*(Ti - To)\n",
+ "print'the indoor air temperature %f Celcius'%Ti\n"
+ ],
+ "language": "python",
+ "metadata": {},
+ "outputs": [
+ {
+ "output_type": "stream",
+ "stream": "stdout",
+ "text": [
+ "the indoor air temperature 26.111111 Celcius\n"
+ ]
+ }
+ ],
+ "prompt_number": 1
+ },
+ {
+ "cell_type": "heading",
+ "level": 2,
+ "metadata": {},
+ "source": [
+ "Example 2-13 ,Page No.76"
+ ]
+ },
+ {
+ "cell_type": "code",
+ "collapsed": false,
+ "input": [
+ "#Given values\n",
+ "Plamp=80.0;#Power of lamp in W\n",
+ "N=30;#no of lamps\n",
+ "t=12;#time period the light is in use in hours/day\n",
+ "y=250;#days in a year light is in function \n",
+ "UC=0.07;#unit cost in $\n",
+ "\n",
+ "#Calculation\n",
+ "LP=Plamp*N/1000;#Lighting power in kW\n",
+ "OpHrs=t*y;#Operating hours\n",
+ "LE=LP*OpHrs;#Lighting energy in kW\n",
+ "LC=LE*UC;#Lighting cost\n",
+ "print'the annual energy cost $%i'%LC\n"
+ ],
+ "language": "python",
+ "metadata": {},
+ "outputs": [
+ {
+ "output_type": "stream",
+ "stream": "stdout",
+ "text": [
+ "the annual energy cost $504\n"
+ ]
+ }
+ ],
+ "prompt_number": 2
+ },
+ {
+ "cell_type": "heading",
+ "level": 2,
+ "metadata": {},
+ "source": [
+ "Example 2-15 ,Page No.82"
+ ]
+ },
+ {
+ "cell_type": "code",
+ "collapsed": false,
+ "input": [
+ "#Given values\n",
+ "Ein=2.0;#Power of electric burner in kW\n",
+ "n1=0.73;#Efficiency of open burners\n",
+ "n2=0.38;#efficency of gas units\n",
+ "CinH=0.09;#Unit cost of electricity in $\n",
+ "CinB=0.55;#Unit cost of natural gas in $\n",
+ "\n",
+ "#Calculations\n",
+ "QutH= Ein * n1;\n",
+ "print'rate of energy consumption by the heater %f kW'%round(QutH,2);\n",
+ "CutH= CinH / n1;\n",
+ "print'the unit cost of utilized energy for heater $%f/kWh'%round(CutH,3);\n",
+ "QutB= QutH / n2 ;\n",
+ "print'rate of energy consumption by the burner %f kW'%round(QutB,2);\n",
+ "CutB= CinB / n2 / 29.3; # 1 therm = 29.3 kWh\n",
+ "print'the unit cost of utilized energy for burner %f kWh'%round(CutB,3);\n"
+ ],
+ "language": "python",
+ "metadata": {},
+ "outputs": [
+ {
+ "output_type": "stream",
+ "stream": "stdout",
+ "text": [
+ "rate of energy consumption by the heater 1.460000 kW\n",
+ "the unit cost of utilized energy for heater $0.123000/kWh\n",
+ "rate of energy consumption by the burner 3.840000 kW\n",
+ "the unit cost of utilized energy for burner 0.049000 kWh\n"
+ ]
+ }
+ ],
+ "prompt_number": 3
+ },
+ {
+ "cell_type": "heading",
+ "level": 2,
+ "metadata": {},
+ "source": [
+ "Example 2-16 ,Page No.84"
+ ]
+ },
+ {
+ "cell_type": "code",
+ "collapsed": false,
+ "input": [
+ "#there is a 0.204% error in the last part of the question due to rounding off the intermidiate steps in the solution\n",
+ "\n",
+ "#Constants used\n",
+ "g=9.81;#acceleration due to gravity in m/s^2;\n",
+ "\n",
+ "#Given values\n",
+ "h=50.0;#Depth of water in m\n",
+ "m=5000.0;#mass flow rate of water in kg/sec\n",
+ "Wout=1862.0;#generated electric power in kW\n",
+ "ngen=0.95;#efficiency of turbine\n",
+ "\n",
+ "#calculation\n",
+ "X=g*h/1000.0;# X stands for the differnce b/w change in mechanical energy per unit mass\n",
+ "R=m*X;#rate at which mech. energy is supplied to turbine in kW\n",
+ "nov=Wout/R;#overall efficiency i.e turbine and generator\n",
+ "print'overall efficiency is %f'%round(nov,2);\n",
+ "ntu=nov/ngen;#efficiency of turbine\n",
+ "print'efficiency of turbine is %f'%round(ntu,2);\n",
+ "Wsh=ntu*R;#shaft output work\n",
+ "print'shaft power output %i kW'%round(Wsh,0)\n",
+ "\n"
+ ],
+ "language": "python",
+ "metadata": {},
+ "outputs": [
+ {
+ "output_type": "stream",
+ "stream": "stdout",
+ "text": [
+ "overall efficiency is 0.760000\n",
+ "efficiency of turbine is 0.800000\n",
+ "shaft power output 1960 kW\n"
+ ]
+ }
+ ],
+ "prompt_number": 12
+ },
+ {
+ "cell_type": "heading",
+ "level": 2,
+ "metadata": {},
+ "source": [
+ "Example 2-17 ,Page No.85"
+ ]
+ },
+ {
+ "cell_type": "code",
+ "collapsed": false,
+ "input": [
+ "#Given values\n",
+ "Pstd=4520.0;\n",
+ "Phem=5160.0;#prices of std and high eff motor in USD\n",
+ "R=60*0.7457;#rated power in kW from hp\n",
+ "OpHrs=3500.0;#Operating hours\n",
+ "Lf=1.0;#Load Factor\n",
+ "nsh=0.89;#efficiency of shaft\n",
+ "nhem=0.932;#efficiency of high eff. motor\n",
+ "CU=0.08;#per unit cost in $\n",
+ "\n",
+ "#calculation\n",
+ "PS=R*Lf*(1/nsh-1/nhem);#Power savings = W electric in,standard - W electric in,efficient\n",
+ "ES=PS*OpHrs;#Energy savings = Power savings * Operating hours\n",
+ "print'Energy savings %i kWh/year'%ES;\n",
+ "CS=ES*CU;\n",
+ "print'Cost savings per year $%i'%CS;\n",
+ "EIC=Phem-Pstd;#excess intial cost\n",
+ "Y=EIC/CS;\n",
+ "print'simple payback period %f years'%round(Y,1)"
+ ],
+ "language": "python",
+ "metadata": {},
+ "outputs": [
+ {
+ "output_type": "stream",
+ "stream": "stdout",
+ "text": [
+ "Energy savings 7929 kWh/year\n",
+ "Cost savings per year $634\n",
+ "simple payback period 1.000000 years\n"
+ ]
+ }
+ ],
+ "prompt_number": 5
+ },
+ {
+ "cell_type": "heading",
+ "level": 2,
+ "metadata": {},
+ "source": [
+ "Example 2-18 ,Page No.91"
+ ]
+ },
+ {
+ "cell_type": "code",
+ "collapsed": false,
+ "input": [
+ "#Given values\n",
+ "#NOx details\n",
+ "m1=0.0047;#emissions of gas furnaces of NOx in kg/therm\n",
+ "N1=18*10**6;#no. of therms per year \n",
+ "#CO2 details\n",
+ "m2=6.4;#emissions of gas furnaces of CO2 in kg/therm\n",
+ "N2=18*10**6;#no. of therms per year \n",
+ "\n",
+ "#Calculation\n",
+ "NOxSav=m1*N1;\n",
+ "print'NOx savings %f kg/year'%round(NOxSav,1);\n",
+ "CO2Sav=m2*N2;\n",
+ "print'CO2 savings %f kg/year'%round(CO2Sav,1)\n"
+ ],
+ "language": "python",
+ "metadata": {},
+ "outputs": [
+ {
+ "output_type": "stream",
+ "stream": "stdout",
+ "text": [
+ "NOx savings 84600.000000 kg/year\n",
+ "CO2 savings 115200000.000000 kg/year\n"
+ ]
+ }
+ ],
+ "prompt_number": 6
+ },
+ {
+ "cell_type": "heading",
+ "level": 2,
+ "metadata": {},
+ "source": [
+ "Example 2-19 ,Page No.95"
+ ]
+ },
+ {
+ "cell_type": "code",
+ "collapsed": false,
+ "input": [
+ "#Constants used\n",
+ "e=0.95;#Emissivity\n",
+ "tc=5.67*10**-8;#thermal conductivity in W/m^2 K^4\n",
+ "\n",
+ "#Given values\n",
+ "h=6;#convection heat transfer coefficient in W/m^2 C\n",
+ "A=1.6;#cross-sectional area in m^2\n",
+ "Ts=29;#average surface temperature in C\n",
+ "Tf=20;#room temperature in C\n",
+ "\n",
+ "#Calculation\n",
+ "#convection rate\n",
+ "Q1=h*A*(Ts-Tf);\n",
+ "#radiation rate\n",
+ "Q2=e*tc*A*((Ts+273)**4-(Tf+273)**4);\n",
+ "Qt=Q1+Q2;\n",
+ "print'the total rate of heat transfer %f W'%round(Qt,1)\n"
+ ],
+ "language": "python",
+ "metadata": {},
+ "outputs": [
+ {
+ "output_type": "stream",
+ "stream": "stdout",
+ "text": [
+ "the total rate of heat transfer 168.100000 W\n"
+ ]
+ }
+ ],
+ "prompt_number": 7
+ }
+ ],
+ "metadata": {}
+ }
+ ]
+}
\ No newline at end of file |