{ "cells": [ { "cell_type": "markdown", "metadata": {}, "source": [ "# Chapter 5 : Combustion Mechanism, Combustion Equipment And Firing Methods" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "## Ex 5.1 Page 308" ] }, { "cell_type": "code", "execution_count": 1, "metadata": { "collapsed": false }, "outputs": [ { "name": "stdout", "output_type": "stream", "text": [ " The total surface area of the particles in the bed As = 8423 m**2 \n" ] } ], "source": [ "#Input data\n", "Vs=2500##The mass of a bed of solid particles in kg\n", "p=2650##The density of the solid in kg/m**3\n", "d=800*10**-6##The mean particle size in m\n", "s=0.84##The sphericity of the particle\n", "\n", "#Calculations\n", "As=(6*Vs)/(p*d*s)##The total surface area of the particles in the bed\n", "\n", "#Output\n", "print \" The total surface area of the particles in the bed As = %3.0f m**2 \"%(As)\n" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "## Ex 5.2 Page 309" ] }, { "cell_type": "code", "execution_count": 12, "metadata": { "collapsed": false }, "outputs": [ { "name": "stdout", "output_type": "stream", "text": [ " (a) The voidage of the bed = 0.417 \n", " (b) The minimum fluidization velocity Umf = 0.187 m/s \n" ] } ], "source": [ "#Input data\n", "d=427*10**-6##The mean particle size in m\n", "pg=1.21##The density of air in kg/m**3\n", "v=1.82*10**-5##The viscosity of air in kg/ms\n", "pl=1620##The density of the loosely packed bed in kg/m**3\n", "ps=2780##The density of the solids in kg/m**3\n", "c1=27.2##(Grace,1982)constant value.\n", "c2=0.0408##(Grace,1982)constant value\n", "g=9.812##Gravitational forc constant in m/s**2\n", "\n", "#Calculations\n", "E=1-(pl/ps)##The voidage of the bed\n", "Ar=((pg)*(ps-pg)*g*(d**3))/v**2##Archimedes number\n", "Re=(c1**2+(c2*Ar))**(0.5)-c1##Reynolds number\n", "Umf=Re*v/(pg*d)##Minimum superficial velocity in m/s\n", "\n", "#Output\n", "print \" (a) The voidage of the bed = %3.3f \\n (b) The minimum fluidization velocity Umf = %3.3f m/s \"%(E,Umf)" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "## Ex 5.3 Page 309" ] }, { "cell_type": "code", "execution_count": 25, "metadata": { "collapsed": false }, "outputs": [ { "name": "stdout", "output_type": "stream", "text": [ "The sphericity of particles is = 0.811 \n" ] } ], "source": [ "from scipy.optimize import fsolve\n", "#Input data\n", "d=427*10**-6##The mean particle size in m\n", "pg=1.21##The density of air in kg/m**3\n", "v=1.82*10**-5##The viscosity of air in kg/ms\n", "Umf=0.14##Minimum superficial velocity in m/s\n", "Ar=7753##Archimedes number from previous example problem\n", "\n", "#Calculations\n", "\n", "Re=(Umf*pg*d)/v##Reynolds number\n", "def F(x):##function definition\n", " f = 7753*x**2- 381.1*x -4793#\n", " return f\n", "x = 100##Initial guss\n", "y = fsolve(F,x)#\n", "\n", "#Output\n", "print \"The sphericity of particles is = %3.3f \"%(y)" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "## Ex 5.4 Page 310" ] }, { "cell_type": "code", "execution_count": 26, "metadata": { "collapsed": false }, "outputs": [ { "name": "stdout", "output_type": "stream", "text": [ "The required flow rate of limestone is 2405.3 kg/h \n" ] } ], "source": [ "from __future__ import division\n", "#Input data\n", "O=35##The output of the fluidized bed combustion system in MW\n", "n=0.80##Efficiency of the fluidized bed combustion system \n", "H=26##The heating value of coal in MJ/kg\n", "S=3.6##Sulphur content in the coal in %\n", "C=3##The calcium sulphur ratio \n", "Ca=85##The amount of calcium carbonate in the limestone in %\n", "CaCO3=100##The molecular weight of CaCO3\n", "\n", "#Calculations\n", "Cb=O/(n*H)##Coal burning rate in kg/s\n", "Cb1=Cb*3600##Coal burning rate in kg/h\n", "Sf=(Cb1*(S/100))/32##Flow rate of sulphur in Kmol/h\n", "Cf=Sf*C##The flow rate of calcium in Kmol/h\n", "Caf=Cf*CaCO3##Mass flow rate of CaCO3 in kg/h\n", "L=Caf/(Ca/100)##Mass flow rate of limestone in kg/h\n", "\n", "#Output\n", "print \"The required flow rate of limestone is %3.1f kg/h \"%(L)" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "## Ex 5.5 Page 310" ] }, { "cell_type": "code", "execution_count": 27, "metadata": { "collapsed": false }, "outputs": [ { "name": "stdout", "output_type": "stream", "text": [ " (a) The rate of heat removal from the bed = 6405 kW \n", " (b) The rate of heat removal from the above bed zone = 16333 kW \n" ] } ], "source": [ "#Input data\n", "CV=24##The calorific value of the fuel in MJ/kg\n", "C=0.65##The amount of calorific value released in the bed in %\n", "to=850##Temperature at which products leave in degree centigrade\n", "ti=30##The inlet temperature in degree centigrade\n", "tb=850##The bed temperature in degree centigrade\n", "A=14.5##The air fuel ratio by mass\n", "Cp=1.035##The specific heat of the products leaving the bed surface in kJ/kgK\n", "B=7000##The burning rate of coal in kg/h\n", "\n", "#Calculations\n", "H=(C*CV*1000)-(A*Cp*(to-ti))##Heat removal from the bed per kg fuel in kJ/kg fuel\n", "Hr=(H*B)/3600##Rate of heat removal from the bed in kW\n", "Hb=(B/3600)*(1-C)*CV*1000##The rate of heat removal from the above bed zone in kW\n", "\n", "#Output\n", "print \" (a) The rate of heat removal from the bed = %3.0f kW \\n (b) The rate of heat removal from the above bed zone = %3.0f kW \"%(Hr,Hb)" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "## Ex 5.6 Page 311" ] }, { "cell_type": "code", "execution_count": 28, "metadata": { "collapsed": false }, "outputs": [ { "name": "stdout", "output_type": "stream", "text": [ " (a) The planform area = 2.4 m**2 \n", " (b) Fuel burning rate = 0.192 kg/s \n", " Air flow rate = 2.1888 kg/s \n", " Planform area = 2.58 m**2 \n" ] } ], "source": [ "#Input data\n", "tb=850##The bed temperature in degree centigrade\n", "CV=25##The calorific value of the fuel in MJ/kg\n", "A=9.5##The stoichiometric air fuel ratio by mass\n", "E=20##The amount of excess air used in %\n", "F=4.8##The total fueling rate in MW\n", "p=0.3145##The density of air at bed temperature in kg/m**3\n", "f=2##The firing rate in MW/m**2\n", "v=2.7##The fluidizing velocity in m/s\n", "\n", "#Calculations\n", "P=F/f##Planform area in m**2\n", "m=(F*1000)/(CV*1000)##Fuel burning rate in kg/s\n", "ma=A*(1+(E/100))*m##Mass flow rate of air in kg/s\n", "Pa=ma/(p*v)##Planform area in m**2\n", "\n", "#Output\n", "print \" (a) The planform area = %3.1f m**2 \\n (b) Fuel burning rate = %3.3f kg/s \\n Air flow rate = %3.4f kg/s \\n Planform area = %3.2f m**2 \"%(P,m,ma,Pa)" ] } ], "metadata": { "kernelspec": { "display_name": "Python 2", "language": "python", "name": "python2" }, "language_info": { "codemirror_mode": { "name": "ipython", "version": 2 }, "file_extension": ".py", "mimetype": "text/x-python", "name": "python", "nbconvert_exporter": "python", "pygments_lexer": "ipython2", "version": "2.7.9" } }, "nbformat": 4, "nbformat_minor": 0 }