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diff --git a/Applied_Thermodynamics/Chapter18.ipynb b/Applied_Thermodynamics/Chapter18.ipynb new file mode 100755 index 00000000..a243ce8d --- /dev/null +++ b/Applied_Thermodynamics/Chapter18.ipynb @@ -0,0 +1,830 @@ +{ + "metadata": { + "name": "", + "signature": "sha256:59b1fc8c8d34f6daf41da52caf7a93f8b68598a246de207d874cbeb5751e9b6d" + }, + "nbformat": 3, + "nbformat_minor": 0, + "worksheets": [ + { + "cells": [ + { + "cell_type": "heading", + "level": 1, + "metadata": {}, + "source": [ + "Chapter 18: Introduction to Refrigeration and Airconditioning" + ] + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 1, page no. 838" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "from __future__ import division\n", + "\n", + "#Variable Declaration: \n", + "Q1 = 500 #Heat extracted by carnot cycle(in kJ/min):\n", + "T1 = -16+273 #Temperature of refrigerated space(in K):\n", + "T2 = 27+273 #Atmospheric temperature(in K):\n", + "\n", + "#Calculations:\n", + "Q2 = Q1*(T2/T1) #Heat rejected(in kJ/min):\n", + "W = Q2-Q1 #Work input required(in kJ/min):\n", + "\n", + "#Results: \n", + "print \"Work input: \",round(W,2),\"kJ/min\"" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Work input: 83.66 kJ/min\n" + ] + } + ], + "prompt_number": 2 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 2, page no. 838" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "from __future__ import division\n", + "\n", + "#Variable Declaration: \n", + "T1 = -5+273 #Operating temperature(in K):\n", + "T2 = 27+273\n", + "Cpw = 4.18 #Specific heats(in kJ/kg.K):\n", + "L = 335 #Latent heat(in kJ/kg):\n", + "C = 800 #Capacity(in tons):\n", + "\n", + "#Calculations:\n", + "q = C*3.5 #Heat extraction rate(in kJ/s):\n", + "q1 = Cpw*(27-0)+L #Heat to be removed per kg of water(in kJ/kg):\n", + "m = q/q1 #Ice formation rate(in kg/s):\n", + "COP = (T1/(T2-T1)) #COP:\n", + "W = q/COP/0.7457 #Work done(in hp):\n", + "\n", + "\n", + "print \"Mass rate of ice formation: \",round(m,2),\"kg/s\"\n", + "print \"HP required: \",round(W,2),\"hp\"" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Mass rate of ice formation: 6.25 kg/s\n", + "HP required: 448.34 hp\n" + ] + } + ], + "prompt_number": 4 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 3, page no. 839" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "from __future__ import division\n", + " \n", + "#Variable Declaration: \n", + "W = 3 #Work done(in hp):\n", + "T1 = -27+273 #Temperature to be maintained(in K):\n", + "\n", + "#Calculations:\n", + "COP = 1*3.5/(W*0.7457)#COP:\n", + "T2 = T1+T1/COP #Temperature of surroundings(in K):\n", + "\n", + "#Results: \n", + "print \"COP: \",round(COP,2)\n", + "print \"Temperature of surroundings: \",round(T2,2),\"K\"" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "COP: 1.56\n", + "Temperature of surroundings: 403.24 K\n" + ] + } + ], + "prompt_number": 6 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 4, page no. 839" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "from __future__ import division\n", + "\n", + "#Variable Declaration: \n", + "r1 = 8 #Pressure ratio:\n", + "T1 = -33+273 #Operating temperatures(in K)\n", + "T3 = 27+273\n", + "nic = 0.85 #Isentropic efficiency of compression:\n", + "nie = 0.90 #Isentropic efficiency of expansion:\n", + "Cp = 1.005 #Specific heat(in kJ/kg):\n", + "r = 1.4 #Adiabatic index of compression:\n", + "m = 1 #Air flow rate(in kg/s):\n", + "\n", + "#Calculations:\n", + "T2a = T1*(r1)**((r-1)/r) #Temperature at state 2'(in K):\n", + "T2 = (T2a-T1)/nic+T1 #Temperature at state 2(in K):\n", + "T4a = T3*(1/r1)**((r-1)/r) #Temperature at state 4'(in K):\n", + "T4 = T3-(T3-T4a)*nie #Temperature at state 2'(in K):\n", + "Wc = Cp*(T2-T1) #Work during compression(in kJ/s):\n", + "Wt = Cp*(T3-T4) #Work during expansion(in kJ/s):\n", + "Qref = Cp*(T1-T4) #Refrigeration effect(in kJ/s):\n", + "W = Wc-Wt #Net work required(in kJ/s):\n", + "COP = Qref/W #COP:\n", + "\n", + "#Results: \n", + "print \"Refrigeration capacity: \",round(Qref,2),\"kJ/s\"\n", + "print \"COP: \",round(COP,2)" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Refrigeration capacity: 61.25 kJ/s\n", + "COP: 0.56\n" + ] + } + ], + "prompt_number": 7 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 5, page no. 840" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "from __future__ import division\n", + " \n", + "\n", + "#Variable Declaration: \n", + "T1 = 7+273 #Operating temperatures(in K)\n", + "T3 = 27+273\n", + "p1 = 1 #Pressures(in bar):\n", + "p2 = 5\n", + "r = 1.4 #Adiabatic index of compression:\n", + "Cp = 1.005 #Specific heat(in kJ/kg):\n", + "T2 = T1*(p2/p1)**((r-1)/r) #Temperature at state 2(in K):\n", + "T4 = T3/((p2/p1)**((r-1)/r)) #Temperature at state 4(in K):\n", + "Q23 = Cp*(T2-T3) #Heat rejected in process 2-3(in kJ/kg):\n", + "Q41 = Cp*(T1-T4) #Heat picked during process 4-1(in kJ/kg):\n", + "W = Q23-Q41 #Net work(in kJ/kg):\n", + "COP = Q41/W #COP:\n", + "\n", + "#Results: \n", + "print \"COP: \",round(COP,2)" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "COP: 1.71\n" + ] + } + ], + "prompt_number": 9 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 6, page no. 841" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "from __future__ import division\n", + " \n", + "\n", + "#Variable Declaration: \n", + "p1 = 1 #Pressure(in bar):\n", + "p2 = 5.5\n", + "T1 = -10+273 #Operating temperatures(in K):\n", + "T3 = 27+273\n", + "m = 0.8 #Air flow rate(in kg/s):\n", + "Cp = 1.005 #Specific heat(in kJ/kg):\n", + "r = 1.4 #Adiabatic index of compression:\n", + "R = 0.287 #Gas constant(in kJ/kg.K):\n", + "\n", + "#Calculations:\n", + "T2 = T1*(p2/p1)**((r-1)/r) #Temperature at state 2(in K):\n", + "T4 = T3/((p2/p1)**((r-1)/r)) #Temperature at state 4(in K):\n", + "C = m*Cp*(T1-T4) #Refrigeration capacity(in kJ/s):\n", + "Wc = m*r/(r-1)*R*(T2-T1) #Work required to run the comoressor(in kJ/s):\n", + "W = m*Cp*((T2-T3)-(T1-T4)) #Net work input(in kJ/s):\n", + "COP = C/W #COP:\n", + "\n", + "#Results: \n", + "print \"Refrigeration capacity: \",round(C,2),\"kJ/s\"\n", + "print \"HP required to run compressor: \",round(Wc/0.7457,2),\"hp\"\n", + "print \"COP: \",round(COP,2)" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Refrigeration capacity: 63.25 kJ/s\n", + "HP required to run compressor: 177.86 hp\n", + "COP: 1.59\n" + ] + } + ], + "prompt_number": 12 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 7, page no. 843" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "from __future__ import division\n", + " \n", + "\n", + "#Variable Declaration: \n", + "p1 = 1.2 #Pressure(in bar):\n", + "p6 = p1\n", + "p3 = 4\n", + "p2 = p3\n", + "p4 = 1\n", + "p7 = 0.9\n", + "T1 = 288 #Temperatures(in K):\n", + "T6 = T1\n", + "T5 = 25+273\n", + "T3 = 323\n", + "T8 = 30+273\n", + "n = 1.45\n", + "n1 = 1.3\n", + "T2 = T1*(p2/p1)**((n-1)/n) #Temperature at state 2(in K):\n", + "T2 = 418.47\n", + "Cp = 1.005\n", + "\n", + "#Calculations: \n", + "T4 = T3*(p4/p3)**((n1-1)/n1) #Temperature at state 4(in K):\n", + "T4 = 234.57\n", + "m = 10*3.5/(Cp*(T5-T4)) #Refrigeration effect(in kg/s):\n", + "T7 = T6*(p7/p6)**((n1-1)/n1) #Temperature at state 7(in K):\n", + "rm = m*(T2-T3)/(T8-T7)+m #Ram air mass flow rate(in kg/s):\n", + "W = m*Cp*(T2-T1) #Work input to the compressor(in kJ/s):\n", + "COP = 10*3.5/W #COP:\n", + "\n", + "#Results: \n", + "print \"Air mass flow rate in cabin: \",round(m,2),\"kg/s\"\n", + "print \"Ram air mass flow rate: \",round(rm,2),\"kg/s\"\n", + "print \"COP: \",round(COP,3)" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Air mass flow rate in cabin: 0.55 kg/s\n", + "Ram air mass flow rate: 2.11 kg/s\n", + "COP: 0.486\n" + ] + } + ], + "prompt_number": 14 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 8, page no. 844" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "from __future__ import division\n", + "\n", + "#Variable Declaration: \n", + "p0 = 0.9 #Pressures(in bar):\n", + "p1 = 1\n", + "p2 = 4\n", + "p3 = p2\n", + "p4 = p3\n", + "p5 = 1.03\n", + "T6 = 298 #Temperatures(in K):\n", + "T0 = 276\n", + "Cp = 1.005 #Specific heat(in kJ/kg):\n", + "r = 1.4 #Adiabatic index of compression:\n", + "C = 15 #Refrigeration capacity:\n", + "nic = 0.9 #Isentropic efficiency for compressor:\n", + "nit = 0.8 #Isentropic efficiency for turbine:\n", + "\n", + "#Calculations:\n", + "T1 = T0*(p1/p0)**((r-1)/r) #Temperature at state 1(in K):\n", + "T2a = T1*(p2/p1)**((r-1)/r) #Temperature at state 2'(in K):\n", + "T2 = T1+(T2a-T1)/nic #Temperature at state 2(in K):\n", + "T3 = 0.34*T2 #Temperature at state 3(in K):\n", + "T4 = T3-10 #Temperature at state 4(in K):\n", + "T5a = T4*(p5/p4)**((r-1)/r) #Temperature at state 5'(in K):\n", + "T5 = T4-(T4-T5a)*nit #Temperature at state 5(in K):\n", + "m = C*3.5/(Cp*(T6-T5)) #Mass flow rate(in kg/s):\n", + "W = m*Cp*(T2-T1) #Work input(in kJ/s):\n", + "COP = C*3.5/W #COP:\n", + "\n", + "#Results: \n", + "print \"COP: \",round(COP,2)\n", + "print \"HP required: \",round(W/0.7457,2),\"hp\"" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "COP: 1.27\n", + "HP required: 55.51 hp\n" + ] + } + ], + "prompt_number": 16 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 9, page no. 846" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "from __future__ import division\n", + "\n", + "\n", + "#Variable Declaration: \n", + "T1 = -15+273\t\t #Operating temperatures(in K):\n", + "T2 = 25+273\n", + "h2 = 1317.95 #kJ/kg \n", + "s2 = 4.4809 #kJ/kg.K\n", + "h3 = 99.94 #kJ/kg\n", + "s3 = 0.3386 #kJ/kg.K\n", + "h9 = -54.51 #kJ/kg\n", + "s9 = -0.2132 #kJ/kg.K\n", + "s4 = 0.3855 #kJ/kg.K\n", + "\n", + "#Calculations:\n", + "h4 = h3\n", + "s8 = s3\n", + "s1 = s2\n", + "C = T1*(s1-s4)\t\t\t\t #Refrigeration effect(in kJ/kg):\n", + "W = h3-h9-T1*(s3-s9)+(T2-T1)*(s1-s8)\t#Work done(in kJ/kg):\n", + "COP = C/W\t\t\t\t #COP:\n", + "\n", + "#Results: \n", + "print \"COP: \",round(COP,2)" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "COP: 5.94\n" + ] + } + ], + "prompt_number": 20 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 10, page no. 848" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "from __future__ import division\n", + "from math import e\n", + "\n", + "#Variable Declaration: \n", + "T1 = -20+273\t\t\t#Operating temperature(in K):\n", + "T3 = 40+273\n", + "p2 = 9.61\t\t\t\t#Pressures(in bar):\n", + "p1 = 1.51\n", + "n = 1.13\n", + "N = 1200\t\t\t\t#Speed(in rpm):\n", + "h1 = 178.61 #kJ/kg\n", + "h3 = 73.53 #kJ/kg\n", + "h4 = h3\n", + "s1 = 0.7082 #kJ/kg.K\n", + "s2 = s1\n", + "sg = 0.682 #kJ/kg.K\n", + "Cpg = 0.747 #kJ/kg.K\n", + "hg = 203.05 #kJ/kg\n", + "vg = 0.1088 #m**3/kg\n", + "m1 = 2.86 #ton\n", + "C = 0.02\t\t\t #Clearance volume:\n", + "\n", + "#Calculations:\n", + "T2 = T3*(e)**((s1-sg)/Cpg)\t#Temperature of state 2(in K):\n", + "h2 = hg+Cpg*(T2-T3)\t\t#Enthalpy after compression(in kJ/kg):\n", + "Wc = h2-h1\t\t\t\t#Compression work(in kJ/kg):\n", + "r = h1-h4\t\t\t\t#Refrigeration effect(in kJ/kg):\n", + "m = m1*3.5/r\t\t\t#Mass flow rate(in kg/s):\n", + "COP = r/Wc\t\t\t\t#COP:\n", + "nv = 1+C-C*(p2/p1)**(1/n)\t\t\t\t#Volumetric efficiency:\n", + "V = m*60*vg/(nv*N)\t\t\t\t#Piston printlacement(in m**3):\n", + "\n", + "#Results: \n", + "print \"COP: \",round(COP,3)\n", + "print \"Piston printlacement: \",round(V*10**6,2),\"cm**3\"" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "COP: 3.205\n", + "Piston printlacement: 565.05 cm**3\n" + ] + } + ], + "prompt_number": 22 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 11, page no. 850" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "from __future__ import division\n", + " \n", + "\n", + "#Variable Declaration: \n", + "#From steam tables:\n", + "h1 = 322.28 #kJ/kg\t\t\t\t\n", + "h2 = 342.32 #kJ/kg\n", + "s2 = 1.1937 #kJ/kg.K\n", + "x1 = 0.961\n", + "h1 = 312.08 #kJ/kg\n", + "h3 = 144.11 #kJ/kg\n", + "h4 = 115.22 #kJ/kg\n", + "m1 = 2\t\t\t\t#Refrigeration effect(in kW):\n", + "\n", + "#Calculations:\n", + "s1 = s2\n", + "h5 = h4\n", + "r = h1-h5\t\t\t\t#Refrigeration effect(in kJ/kg):\n", + "m = m1/r\t\t\t\t#Refrigerant flow rate(in kg/s):\n", + "Wc = h2-h1\t\t\t\t#Compressor work(in kJ/kg):\n", + "COP = r/Wc\t\t\t\t#COP:\n", + "\n", + "#Results: \n", + "print \"COP: \",round(COP,2)\n", + "print \"Mass flow rate: \",round(m,4),\"kg/s\"" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "COP: 6.51\n", + "Mass flow rate: 0.0102 kg/s\n" + ] + } + ], + "prompt_number": 24 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 12, page no. 851" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "from __future__ import division\n", + "\n", + "\n", + "#Variable Declaration: \n", + "w = 0.016\t\t\t\t#Specific humidity(in gm/kg):\n", + "pvsat = 0.03098\t\t\t#Saturated partial pressure of vapour(in bar):\n", + "pv = w/0.622*1.013/(1+w/0.622)#Partial pressure of vapour(in bar):\n", + "r = pv/pvsat*100\t\t\t#Relative humidity:\n", + "\n", + "#Calculations:\n", + "print \"Partial pressure of vapour: \",round(pv,4)\n", + "print \"Relative humidity: \",round(r,2),\"%\"" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Partial pressure of vapour: 0.0254\n", + "Relative humidity: 82.0 %\n" + ] + } + ], + "prompt_number": 27 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 13, page no. 852" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "\n", + "from __future__ import division\n", + "\n", + "\n", + "#Variable Declaration: \n", + "r = 0.6\t\t\t\t#Relavite humidity\n", + "pvsat = 0.0425\t\t\t#Saturation pressure(in bar):\n", + "R = 0.287\t\t\t\t#Gas constant(in kJ/kg.K):\n", + "Ta = 303\t\t\t\t#Surrounding temperature(in K):\n", + "hg = 2504.1 #kJ/kg\n", + "Cp = 1.005\t\t\t\t#Specific heat(in kJ/kg.K):\n", + "T = 21.4 \t\t\t\t#Dew point temperature(in C) from steam table:\n", + "pv = 0.0255 #partial pressure of vapour(bar) from steam table:\n", + "#Calculations:\n", + "pa = 1.013-r*pvsat\t\t#Partial pressure of air(in bar):\n", + "w = 0.622*(pv/(1.013-pv))\t#Humidity ratio:\n", + "d = 1.013*10**2*(1+w)/(R*Ta)\t#Density of mixture(in kg/m**3):\n", + "h = Cp*30+w*(hg+1.860*(30-T))#Enthalpy of mixture(in kJ/kg of dry air):\n", + "\n", + "#Results: \n", + "print \"Partial pressure of air: \",round(pa,4),\"bar\"\n", + "print \"Humidity ratio: \",round(w,5),\"jg/kg of dry air\"\n", + "print \"Dew point temperature: \",round(T,1),\"\u00b0C\"\n", + "print \"Density: \",round(d,4),\"kg/m**3\"\n", + "print \"Enthalpy of mixture: \",round(h,1),\"kJ/kg of air\"" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Partial pressure of air: 0.9875 bar\n", + "Humidity ratio: 0.01606 jg/kg of dry air\n", + "Dew point temperature: 21.4 \u00b0C\n", + "Density: 1.1836 kg/m**3\n", + "Enthalpy of mixture: 70.6 kJ/kg of air\n" + ] + } + ], + "prompt_number": 28 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 14, page no. 852" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "\n", + "from __future__ import division\n", + "\n", + "\n", + "#Variable Declaration: \n", + "r = 0.80\t\t\t\t#Relavite humidity\n", + "#From pyschometric chart:\n", + "w1 = 0.0086 #kg/kg of air\t\t\t\t\n", + "w2 = 0.01 #kg/kg of air\n", + "h1 = 37 #kJ/kg\n", + "h2 = 50 #kJ/kg\n", + "v2 = 0.854 #m**3/kg\n", + "\n", + "#Calculations:\n", + "m = w2-w1\t\t\t\t#Mass of water added between states 1 and 2:\n", + "ma = r/v2\t\t\t\t#Mass flow rate:\n", + "m1 = m*ma\t\t\t\t#Total mass of water added(in kg/s):\n", + "q = ma*(h2-h1)\t\t\t\t#Heat transferred(in kJ/s):\n", + "\n", + "#Results: \n", + "print \"Mass of water added: \",round(m1,6),\"kg/s\"\n", + "print \"Heat transferred: \",round(q,2),\"kJ/s\"" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Mass of water added: 0.001311 kg/s\n", + "Heat transferred: 12.18 kJ/s\n" + ] + } + ], + "prompt_number": 30 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 15, page no. 853" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "from __future__ import division\n", + "\n", + "\n", + "#Variable Declaration: \n", + "m1 = 3\t\t\t\t#Mass flow rate(in kg/s):\n", + "m2 = 2\n", + "Cp = 1.005\t\t\t\t#Specific heat(in kJ/kg.K):\n", + "Cps = 1.86\t\t\t\t#Specofoc heat of stream(in kJ/kg.K):\n", + "r1 = 0.30\t\t\t\t#Relative humidity:\n", + "r2 = 0.85\n", + "#From psychometric chart:\n", + "pvsat1 = 0.04246 #bar\t\t\t\t\n", + "pvsat2 = 0.005628\n", + "hg1 = 2520.7 #kJ/kg\n", + "hg2 = 2559.9 #kJ/kg\n", + "T1 = 30 #\u00b0C\n", + "Tdp1 = 10.5\n", + "T2 = 35 \n", + "Tdp2 = 32\n", + "\n", + "#Calculations:\n", + "pv1 = pvsat1*r1\t\t\t\t#Partial pressure of vapour at 1(in bar):\n", + "w1 = 0.622*pv1/(1.013-pv1)\t\t#Specific humidity:\n", + "h1 = Cp*T1+w1*(hg1-Cps*(T1-Tdp1))\t#Enthalpy at state 1(in kJ/kg):\n", + "pv2 = pvsat2*r2\t\t\t\t#Partial pressure at state 2(in bar):\n", + "w2 = 0.622*pv2/(1.013-pv2)\t\t#Specific humidity:\n", + "h1 = Cp*T2+w2*(hg2-Cps*(T2-Tdp2))\t#Enthalpy at state 1(in kJ/kg):\n", + "mmix = 1/(m1+m2)*(w1*m1/(1+w1)+w2*m2/(1+w2))\t#Mass of vapour:\n", + "wmix = mmix/(1-mmix)\t\t\t#Specific humidity of mixture:\n", + "pv = 1.013*wmix/0.622/(1+w1/0.622)\t#Partial pressure of water vapour(in bar):\n", + "\n", + "#Results: \n", + "print \"Specific humidity of mixture: \",round(wmix,5),\"kg/kg of dry air\"\n", + "print \"Partial pressure of water vapour in mixture: \",round(pv,5),\"bar\"" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Specific humidity of mixture: 0.00593 kg/kg of dry air\n", + "Partial pressure of water vapour in mixture: 0.00953 bar\n" + ] + } + ], + "prompt_number": 32 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 16, page no. 855" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "\n", + "from __future__ import division\n", + "\n", + "\n", + "#Variable Declaration: \n", + "r = 3\t\t\t\t#Rate at which air enters(in m**3/s):\n", + "h1 = 36.4 #kJ/kg\t\t\t\t#From steam tables:\n", + "h2 = 52 #kJ/kg\n", + "v1 = 0.825 #m**3/kg\n", + "\n", + "#Calculations:\n", + "m = 3/v1\t\t\t\t#Mass of air(in kg/s):\n", + "q = m*(h2-h1)\t\t\t\t#Amount of heat added(in kJ/s):\n", + "\n", + "#Results: \n", + "print \"Heat added: \",round(q,2),\"kJ/s\"" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Heat added: 56.73 kJ/s\n" + ] + } + ], + "prompt_number": 35 + } + ], + "metadata": {} + } + ] +}
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