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diff --git a/Engineering_Thermodynamics_by_P._K._Nag/ch9.ipynb b/Engineering_Thermodynamics_by_P._K._Nag/ch9.ipynb new file mode 100755 index 00000000..0c0c9e93 --- /dev/null +++ b/Engineering_Thermodynamics_by_P._K._Nag/ch9.ipynb @@ -0,0 +1,1016 @@ +{ + "metadata": { + "name": "", + "signature": "sha256:7f2ac1f73c638662f50d765235be56ca14cf295f3e77d6b32e206a78e4a459fc" + }, + "nbformat": 3, + "nbformat_minor": 0, + "worksheets": [ + { + "cells": [ + { + "cell_type": "heading", + "level": 1, + "metadata": {}, + "source": [ + "Chapter 9 : Properties of Pure Substances" + ] + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 9.1 Page No : 295" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "\n", + "# Variables\n", + "tsat = 179.91; # celsius\n", + "vf = 0.001127; # m**3/kg\n", + "vg = 0.19444; #m**3/kg\n", + "\n", + "# Calculation\n", + "vfg = vg-vf;\n", + "sf = 2.1387;\n", + "sg = 6.5865;\n", + "sfg = sg-sf;\n", + "\n", + "# Results\n", + "print \"At 1 Mpa saturation temperature is\",tsat,\"degree\"\n", + "print \"Changes in specific volume is\",vfg,\"m3/kg\"\n", + "print \"Change in entropy during evaporation is\",sfg,\"kJ/kg K\"\n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "At 1 Mpa saturation temperature is 179.91 degree\n", + "Changes in specific volume is 0.193313 m3/kg\n", + "Change in entropy during evaporation is 4.4478 kJ/kg K\n" + ] + } + ], + "prompt_number": 1 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 9.3 Page No : 295" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "\n", + "# Variables\n", + "v = 0.09\n", + "vf = 0.001177\n", + "vg = 0.09963;\n", + "\n", + "# Calculation\n", + "x = (v-vf)/(vg-vf);\n", + "hf = 908.79; hfg = 1890.7;\n", + "sf = 2.4474; sfg = 3.8935;\n", + "h = hf+(x*hfg);\n", + "s = sf+(x*sfg);\n", + "\n", + "# Results\n", + "print \"The enthalpy and entropy of the system are %.4f and %.2f kJ/kg and kJ/kg K respectively\"%(s,h)\n", + "\n", + "# rounding off error. please check." + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "The enthalpy and entropy of the system are 5.9601 and 2614.55 kJ/kg and kJ/kg K respectively\n" + ] + } + ], + "prompt_number": 1 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 9.4 Page No : 296" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "from numpy import interp\n", + "\n", + "# Variables\n", + "# for T = 350 degree\n", + "T1 = 350; \n", + "v1 = 0.2003; \n", + "h1 = 3149.5; \n", + "s1 = 7.1369;\n", + "# for T = 400 degree\n", + "T2 = 400; \n", + "v2 = 0.2178; \n", + "h2 = 3257.5; \n", + "s2 = 7.3026;\n", + "\n", + "# Calculation\n", + "# Interpolation for T = 380;\n", + "T = [T1 ,T2];\n", + "v = [v1 ,v2];\n", + "h = [h1 ,h2];\n", + "s = [s1 ,s2];\n", + "v3 = interp(380,T,v);\n", + "h3 = interp(380,T,h);\n", + "s3 = interp(380,T,s);\n", + "\n", + "# Results\n", + "print \"The entropy, enthalpy and volume of stem at 1.4MPa and 380 degree is %.4f kJ/Kg, %.1f kJ/Kg, %.4f kJ/Kg respectively\"%(s3,h3,v3)\n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "The entropy, enthalpy and volume of stem at 1.4MPa and 380 degree is 7.2363 kJ/Kg, 3214.3 kJ/Kg, 0.2108 kJ/Kg respectively\n" + ] + } + ], + "prompt_number": 2 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 9.5 Page No : 296" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "\n", + "# Variables\n", + "Psat = 3.973e06;\n", + "vf = 0.0012512\n", + "vg = 0.05013;\n", + "hf = 1085.36\n", + "hfg = 1716.2;\n", + "sf = 2.7927\n", + "sfg = 3.2802;\n", + "mf = 9 # liquid in kg\n", + "V = 0.04; # volume\n", + "\n", + "# Calculation\n", + "Vf = mf*vf;\n", + "Vg = V-Vf;\n", + "mg = Vg/vg;\n", + "m = mf+mg;\n", + "x = mg/m;\n", + "v = vf+x*(vg-vf);\n", + "h = hf+x*hfg;\n", + "s = sf+(x*sfg);\n", + "u = h-Psat*v*1e-03;\n", + "\n", + "# at T = 250\n", + "uf = 1080.39\n", + "ufg = 1522;\n", + "u_ = uf+x*ufg;\n", + "\n", + "# Results\n", + "print \"The pressure is %.3f Mpa\"%(Psat/1000000)\n", + "print \"The mass is %.3f Kg\"%m\n", + "print \"Specific volume is %.5f m3/Kg\"%v\n", + "print \"Enthalpy is %.2f kJ/Kg\"%h\n", + "print \"The entropy is %.4f kJ/Kg K\"%s\n", + "print \"The interal energy is %.2f kJ/Kg\"%u\n", + "print \"u = %.2f kJ/kg\"%u_ #incorrect answer in the textbook\n", + "\n", + "# rounding off error. please check. book answers may wrong." + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "The pressure is 3.973 Mpa\n", + "The mass is 9.573 Kg\n", + "Specific volume is 0.00418 m3/Kg\n", + "Enthalpy is 1188.13 kJ/Kg\n", + "The entropy is 2.9891 kJ/Kg K\n", + "The interal energy is 1171.53 kJ/Kg\n", + "u = 1171.53 kJ/kg\n" + ] + } + ], + "prompt_number": 13 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 9.6 Page No : 297" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "import math \n", + "from numpy import interp\n", + "\n", + "# Part (a)\n", + "vg1_ = 0.8919\n", + "T1_ = 120;\n", + "vg2_ = 0.77076\n", + "T2_ = 125;\n", + "vg_ = [vg1_, vg2_]\n", + "T_ = [T1_, T2_];\n", + "v1 = 0.7964;\n", + "h1 = 2967.6;\n", + "P1 = 0.3e03; \t\t\t# in Kpa\n", + "\n", + "# Calculation and Results\n", + "T1 = interp(v1,vg_,T_);\n", + "print \"The steam become saturated at \",T1,\"degree\"\n", + "\n", + "# Part (b)\n", + "vf = 0.001029\n", + "vg = 3.407;\n", + "hf = 334.91\n", + "hfg = 2308.8;\n", + "Psat = 47.39; \t\t\t# In kPa\n", + "v2 = v1;\n", + "x2 = (v1-vf)/(vg-vf);\n", + "h2 = hf+x2*hfg;\n", + "P2 = Psat;\n", + "Q12 = (h2-h1)+v1*(P1-P2);\n", + "\n", + "print \"The quality factor at t=80 degree is %.4f\"%x2\n", + "print \"The heat transfered per kg of steam in cooling from 250 degree to 80 degree %.2f kJ/Kg\"%Q12\n", + "\n", + "# rounding off error. interp function gives slightly different answer." + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "The steam become saturated at 125.0 degree\n", + "The quality factor at t=80 degree is 0.2335\n", + "The heat transfered per kg of steam in cooling from 250 degree to 80 degree -1892.35 kJ/Kg\n" + ] + } + ], + "prompt_number": 3 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 9.7 Page No : 298" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "# Variables\n", + "# At T = 40 degree\n", + "Psat = 7.384e06;\n", + "sf = 0.5725\n", + "sfg = 7.6845;\n", + "hf = 167.57\n", + "hfg = 2406.7;\n", + "s1 = 6.9189\n", + "h1 = 3037.6;\n", + "\n", + "# Calculation\n", + "x2 = round((s1-sf)/sfg,3) ;\n", + "h2 = hf+(x2*hfg);\n", + "W = h1-h2;\n", + "\n", + "\n", + "# Results\n", + "print \"The ideal work output of the turbine is %.2f kJ/Kg\"%W\n", + "\n", + "# rounding off error. please check using calculator." + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "The ideal work output of the turbine is 882.10 kJ/Kg\n" + ] + } + ], + "prompt_number": 22 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 9.8 Page No : 299" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "import math \n", + "from numpy import interp\n", + "\n", + "# Variables\n", + "w3 = 2.3 #adiabatic mixing\n", + "w1 = 1.0;\n", + "w2 = w3-w1;\n", + "h1 = 2950.0;\n", + "\n", + "# At 0.8MPa, 0.95 dry\n", + "x = 0.95;\n", + "hf = 721.11\n", + "hfg = 2048;\n", + "\n", + "# Calculation\n", + "h2 = hf + (x*hfg);\n", + "h3 = ((w1*h1)+(w2*h2))/w3;\n", + "# Interpolation\n", + "H = [2769.1, 2839.3];\n", + "T = [170.43, 200];\n", + "t3 = interp(2790,H,T);\n", + "s3 = 6.7087; \n", + "s4 = s3;\n", + "x4 = (s3-1.7766)/5.1193;\n", + "h4 = 604.74+(x4*2133.8);\n", + "V4 = math.sqrt(2000*(h3-h4));\n", + "\n", + "# Results\n", + "print \"The condition of superheat after mixing %.2f degree\"%(t3-T[0])\n", + "print \"The velocity of steam leaving the nozzle is %.1f m/sec\"%V4\n", + "\n", + "# rounding off error. please check." + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "The condition of superheat after mixing 8.80 degree\n", + "The velocity of steam leaving the nozzle is 508.7 m/sec\n" + ] + } + ], + "prompt_number": 25 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 9.9 Page No : 300" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "\n", + "# Variables\n", + "h2 = 2716.2\n", + "hf = 844.89\n", + "hfg = 1947.3;\n", + "\n", + "# Calculation\n", + "x1 = (h2-hf)/hfg;\n", + "h3 = 2685.5;\n", + "x4 = (h3-hf)/hfg;\n", + "\n", + "# Results\n", + "print \"The quality of steam in pipe line is %.3f\"%x1\n", + "print \"Maximum moisture is %.2f %%\"%(100-(x4*100))\n", + "\n", + "# rounding off error." + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "The quality of steam in pipe line is 0.961\n", + "Maximum moisture is 5.48 %\n" + ] + } + ], + "prompt_number": 26 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 9.10 Page No : 301" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "\n", + "# Variables\n", + "# At 0.1Mpa, 110 degree\n", + "h2 = 2696.2\n", + "hf = 844.89\n", + "hfg = 1947.3;\n", + "\n", + "# Calculation\n", + "x2 = (h2-hf)/hfg;\n", + "vf = 0.001023; \t\t\t# at T = 70 degree\n", + "V = 0.000150; \t\t\t# In m3\n", + "m1 = V/vf;\n", + "m2 = 3.24;\n", + "x1 = (x2*m2)/(m1+m2);\n", + "\n", + "# Results\n", + "print \"The quality of the steam in the pipe line is %.3f\"%x1\n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "The quality of the steam in the pipe line is 0.910\n" + ] + } + ], + "prompt_number": 8 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 9.11 Page No : 302" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "\n", + "# Variables\n", + "# P = 1MPa\n", + "vf = 0.001127\n", + "vg = 0.1944;\n", + "hg = 2778.1\n", + "uf = 761.68;\n", + "ug = 2583.6\n", + "ufg = 1822;\n", + "# Initial anf final mass\n", + "Vis = 5.\n", + "Viw = 5.;\n", + "Vfs = 6.\n", + "Vfw = 4.\n", + "\n", + "# Calculation\n", + "ms = ((Viw/vf)+(Vis/vg)) - ((Vfw/vf)+(Vfs/vg)) ;\n", + "U1 = ((Viw*uf/vf)+(Vis*ug/vg));\n", + "Uf = ((Vfw*uf/vf)+(Vfs*ug/vg));\n", + "Q = Uf-U1+(ms*hg)\n", + "\n", + "# Results\n", + "print \"The heat transfer during the process is\",round(Q/1000,3),\"kJ\"\n", + "\n", + "# It seems book answer is wrong. please check using calculator." + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "The heat transfer during the process is 1788.192 kJ\n" + ] + } + ], + "prompt_number": 5 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 9.12 Page No : 303" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "import math \n", + "\n", + "# Variables\n", + "m = 0.02\n", + "d = 0.28\n", + "l = 0.305;\n", + "P1 = 0.6e06\n", + "P2 = 0.12e06;\n", + "\n", + "# Calculation and Results\n", + "# At 0.6MPa, t = 200 degree\n", + "v1 = 0.352\n", + "h1 = 2850.1;\n", + "V1 = m*v1;\n", + "Vd = (math.pi/4)*d**2*l;\n", + "V2 = V1+Vd ; \n", + "n = math.log(P1/P2)/math.log(V2/V1);\n", + "W12 = ((P1*V1)-(P2*V2))/(n-1);\n", + "\n", + "print \"The value of n is %.2f\"%n\n", + "print \"The work done by the steam is %.1f kJ\"%(W12/1000)\n", + "\n", + "v2 = V2/m;\n", + "vf = 0.0010476\n", + "vfg = 1.4271;\n", + "x2 = (v2-vf)/vfg ;\n", + "# At 0.12MPa\n", + "uf = 439.3\n", + "ug = 2512.0;\n", + "u2 = uf + (x2*(ug-uf));\n", + "u1 = h1-(P1*v1*1e-03);\n", + "Q12 = m*(u2-u1)+ (W12/1000);\n", + "\n", + "print \"The heat transfer is %.3f kJ\"%Q12\n", + "\n", + "# rounding off error. please check." + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "The value of n is 1.24\n", + "The work done by the steam is 4.7 kJ\n", + "The heat transfer is -1.801 kJ\n" + ] + } + ], + "prompt_number": 32 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 9.13 Page No : 305" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "\n", + "# Variables\n", + "x1 = 1.\n", + "x2 = 0.8;\n", + "# at 0.2MPa\n", + "vg = 0.8857\n", + "v1 = vg\n", + "hg = 2706.7\n", + "h1 = hg; \n", + "m1 = 5.\n", + "V1 = m1*v1;\n", + "\n", + "# Calculation\n", + "# at 0.5MPa\n", + "m2 = 10; \n", + "hf = 640.23\n", + "hfg = 2108.5\n", + "vf = 0.001093\n", + "vfg = 0.3749;\n", + "v2 = vf+(x2*vfg);\n", + "V2 = m2*v2;\n", + "\n", + "Vm = V1+V2;\n", + "m = m1+m2;\n", + "vm = Vm/m;\n", + "u1 = h1;\n", + "h2 = hf+(x2*hfg);\n", + "u2 = h2;\n", + "m3 = m;\n", + "h3 = ((m1*u1)+(m2*u2))/m3;\n", + "u3 = h3; \n", + "v3 = vm;\n", + "# From mollier diagram\n", + "x3 = 0.870\n", + "p3 = 3.5\n", + "s3 = 6.29;\n", + "s1 = 7.1271;\n", + "sf = 1.8607\n", + "sfg = 4.9606;\n", + "s2 = sf+(x2*sfg);\n", + "E = m3*s3-((m1*s1)+(m2*s2));\n", + "\n", + "# Results\n", + "print \"Final pressure is \",p3,\"bar\"\n", + "print \"Steam quality is\",x3\n", + "print \"Entropy change during the process is %.2f kJ/K\"%E\n", + "\n", + "\n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Final pressure is 3.5 bar\n", + "Steam quality is 0.87\n", + "Entropy change during the process is 0.42 kJ/K\n" + ] + } + ], + "prompt_number": 10 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 9.14 Page No : 306" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "\n", + "# Variables\n", + "# At 6 MPa, 400 degree\n", + "h1 = 3177.2\n", + "s1 = 6.5408;\n", + "\n", + "# At 20 degree\n", + "h0= 83.96\n", + "s0 = 0.2966;\n", + "T0 = 293.\n", + "\n", + "# Calculation\n", + "f1 = (h1-h0)-T0*(s1-s0);\n", + "# By interpolation \n", + "t2 = 273. + 393;\n", + "s2 = 6.63;\n", + "h2 = h1;\n", + "f2 = (h2-h0)-T0*(s2-s0);\n", + "df = f1-f2;\n", + "x3s = (s2-1.5301)/(7.1271-1.5301);\n", + "h3s = 504.7+(x3s*2201.9);\n", + "eis = 0.82;\n", + "h3 = h2-eis*(h1-h3s);\n", + "x3 = (h3-504.7)/2201.7;\n", + "s3 = 1.5301+(x3*5.597);\n", + "f3 = (h3-h0)-T0*(s3-s0);\n", + "\n", + "# Results\n", + "print \"The availability of the steam before the throttle valve %.1f kJ/Kg\"%f1\n", + "print \"The availability of the steam after the throttle valve %.2f Kj/Kg\"%f2\n", + "print \"The availability of the steam at the turbine exhaust %.2f kJ/Kg\"%f3\n", + "print \"The specific work output from the turbine is %.1f kJ/Kg\"%(h2-h3)\n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "The availability of the steam before the throttle valve 1263.7 kJ/Kg\n", + "The availability of the steam after the throttle valve 1237.55 Kj/Kg\n", + "The availability of the steam at the turbine exhaust 601.85 kJ/Kg\n", + "The specific work output from the turbine is 546.3 kJ/Kg\n" + ] + } + ], + "prompt_number": 11 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 9.15 Page No : 308" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "\n", + "# Variables\n", + "# At 25 bar, 350 degree\n", + "h1 = 3125.87\n", + "s1 = 6.8481;\n", + "# 30 degree\n", + "h0 = 125.79\n", + "s0 = 0.4369;\n", + "h2 = 2865.5\n", + "s2 = 7.3115;\n", + "# At 0.2 bar 0.95 dry\n", + "hf = 251.4\n", + "hfg = 2358.3;\n", + "sf = 0.8320\n", + "sg = 7.0765;\n", + "\n", + "# Calculation\n", + "h3 = hf+0.92*hfg;\n", + "s3 = sf+(0.92*sg);\n", + "# Part (a)\n", + "T0 = 303;\n", + "f1 = (h1-h0)-(T0*(s1-s0));\n", + "f2 = (h2-h0)-(T0*(s2-s0));\n", + "f3 = (h3-h0)-(T0*(s3-s0));\n", + "\n", + "# Results\n", + "print \"Availability of steam entering at state 1 is %.2f kJ/Kg\"%f1\n", + "print \"Availability of steam leaving at state 2 is %.2f kJ/Kg\"%f2\n", + "print \"Availability of steam leaving at state 3 is %.2f kJ/Kg\"%f3\n", + "\n", + "# Part (b)\n", + "m2m1 = 0.25\n", + "m3m1 = 0.75;\n", + "Wrev = f1-(m2m1*f2)-(m3m1*f3);\n", + "print \"Maximum work is %.2f kJ/Kg\"%Wrev\n", + "\n", + "# Part (c)\n", + "w1 = 600.\n", + "w2 = 150.\n", + "w3 = 450.;\n", + "Q = -10.*3600; \t\t\t# For 1 hour\n", + "I = T0*(w2*s2+w3*s3-w1*s1)-Q;\n", + "print \"Irreversibility is %.2f MJ/h\"%(I/1000)\n", + "\n", + "# rounding off error. please check using calcultor." + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Availability of steam entering at state 1 is 1057.49 kJ/Kg\n", + "Availability of steam leaving at state 2 is 656.71 kJ/Kg\n", + "Availability of steam leaving at state 3 is 202.89 kJ/Kg\n", + "Maximum work is 741.15 kJ/Kg\n", + "Irreversibility is 124.46 MJ/h\n" + ] + } + ], + "prompt_number": 4 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 9.16 Page No : 309" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "\n", + "# Variables\n", + "# At dead state of 1 bar, 300K\n", + "u0 = 113.1\n", + "h0 = 113.2;\n", + "v0 = 0.001005\n", + "s0 = 0.0395;\n", + "T0 = 300.\n", + "P0 = 100.;\n", + "\n", + "# Calculation and Results\n", + "K = h0-(T0*s0);\n", + "# Part (a)\n", + "u = 376.9\n", + "h = 377; \n", + "v = 0.001035\n", + "s = 1.193;\n", + "m = 3 \n", + "a = h - 300 * s\n", + "fi = m*(a - (-5.3)) \t\t\t# As P = P0 = 1 bar\n", + "print \"Energy of system in Part (a) is\",fi,\"kJ\"\n", + "\n", + "# Part (b)\n", + "u = 3099.8\n", + "h = 3446.3\n", + "v = 0.08637\n", + "s = 7.090; \t\t\t# At P = 4 Mpa, t = 500 degree\n", + "m = 0.2;\n", + "b = u +100* v - 300 * s\n", + "fib = m*(b-(-5.3));\n", + "print \"Energy of system in Part (b) is\",fib,\"kJ\"\n", + "\n", + "# Part (c)\n", + "m = 0.4;\n", + "x = 0.85; \t\t\t# Quality\n", + "u = 192+x*2245;\n", + "h = 192+x*2392;\n", + "s = 0.649+x*7.499;\n", + "v = 0.001010+x*14.67;\n", + "c = round(u + 100*v - 300*s,1)\n", + "fic = m*(c - (-5.3));\n", + "print \"Energy of system in Part (c) is\",round(fic,1),\"kJ\"\n", + "\n", + "# Part (d)\n", + "m = 3;\n", + "h = -354.1; s = -1.298; \t\t\t# at 1000kPa, -10 degree\n", + "fid = m*(h-h0-T0*(s-s0))# ((h-h0)-T0*(s-s0));\n", + "print \"Energy of system in Part (d) is\",fid,\"kJ\"\n", + "\n", + "# book answer is wrong. please check." + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Energy of system in Part (a) is 73.2 kJ\n", + "Energy of system in Part (b) is 197.3474 kJ\n", + "Energy of system in Part (c) is 498.3 kJ\n", + "Energy of system in Part (d) is -198.15 kJ\n" + ] + } + ], + "prompt_number": 64 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 9.17 Page No : 310" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "\n", + "# Variables\n", + "# Given\n", + "th1 = 90.+273;\n", + "tc1 = 25.+273;\n", + "tc2 = 50.+273;\n", + "mc = 1.\n", + "T0 = 300.;\n", + "th2p = 60.+273; \t\t\t# Parallel\n", + "th2c = 35.+273; \t\t\t# Counter\n", + "\n", + "# Calculation\n", + "mhp = (tc2-tc1)/(th1-th2p); \t\t\t# Parallel\n", + "mhc = (tc2-tc1)/(th1-th2c); \t\t\t# Counter\n", + "h0 = 113.2\n", + "s0 = 0.395\n", + "T0 = 300; \t\t\t# At 300 K\n", + "h1 = 376.92\n", + "s1 = 1.1925; \t\t\t# At 90 degree\n", + "af1 = mhp*((h1-h0)-T0*(s1-s0));\n", + "\n", + "# Parallel Flow\n", + "h2 = 251.13; s2 =0.8312; \t\t\t# At 60 degree\n", + "h3 = 104.89; s3 = 0.3674; \t\t\t# At 25 degree\n", + "h4 = 209.33; s4 = 0.7038; \t\t\t# At 50 degree\n", + "REG = mc*((h4-h3)-T0*(s4-s3)); \t\t\t# Rate of energy gain\n", + "REL = mhp*((h1-h2)-T0*(s1-s2)); \t\t\t# Rate of energy loss\n", + "Ia = REL-REG; \t\t\t# Energy destruction\n", + "n2a = REG/REL; \t\t\t# Second law efficiency\n", + "\n", + "# Results\n", + "print (\"In parallel flow\")\n", + "print \"The rate of irreversibility is\",Ia,\"kW\"\n", + "print \"The Second law efficiency is %.2f %%\"%(n2a*100)\n", + "\n", + "# Counter flow\n", + "h2 = 146.68\n", + "s2 = 0.5053; \t\t\t# At 35 degree\n", + "REG_b = REG; \t\t\t# Rate of energy gain by hot water is same in both flows\n", + "REL_b = mhc*((h1-h2)-T0*(s1-s2));\n", + "Ib = REL_b-REG_b; \t\t\t# Energy destruction\n", + "n2b = REG_b/REL_b; \t\t\t# Second law efficiency\n", + "\n", + "print (\"In Counter flow\")\n", + "print \"The rate of irreversibility is %.2f kW\"%Ib\n", + "print \"The Second law efficiency is %.2f %%\"%(n2b*100)\n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "In parallel flow\n", + "The rate of irreversibility is 10.98 kW\n", + "The Second law efficiency is 24.28 %\n", + "In Counter flow\n", + "The rate of irreversibility is 7.43 kW\n", + "The Second law efficiency is 32.16 %\n" + ] + } + ], + "prompt_number": 14 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 9.18 Page No : 312" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "\n", + "# Variables\n", + "m = 50 ; \t\t\t# in kg/h\n", + "Th = 23.+273; \t\t\t# Home temperature\n", + "\n", + "# State 1\n", + "T1 = 150.+273;\n", + "h1 = 2746.4;\n", + "s1 = 6.8387;\n", + "\n", + "# State 2\n", + "h2 = 419.0;\n", + "s2 = 1.3071;\n", + "T0 = 318;\n", + "\n", + "# Calculation\n", + "b1 = h1-(T0*s1);\n", + "b2 = h2-(T0*s2);\n", + "Q_max = m*(b1-b2)/(T0/Th-1);\n", + "\n", + "# Results\n", + "print \"The maximum cooling rate is %.0f kW\"%(Q_max/3600)\n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "The maximum cooling rate is 106 kW\n" + ] + } + ], + "prompt_number": 15 + } + ], + "metadata": {} + } + ] +}
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