{ "cells": [ { "cell_type": "markdown", "metadata": {}, "source": [ "# Chapter 15 Vapor cycle and processes" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "## Ex:15.1 Pg:697" ] }, { "cell_type": "code", "execution_count": 1, "metadata": { "collapsed": false }, "outputs": [ { "name": "stdout", "output_type": "stream", "text": [ "from steam tables,\n", "Thermal efficiency = 45 percent\n", "\n", " Furnace efficiency = 33.8 percent\n" ] } ], "source": [ "#Initialization of variables\n", "p1=600 #psia\n", "p2=0.2563 #psia\n", "t1=486.21 #F\n", "t2=60 #F\n", "fur=0.75\n", "#calculations\n", "print \"from steam tables,\"\n", "h1=1203.2\n", "hf1=471.6\n", "hfg1=731.6\n", "h2=1088\n", "hf2=28.06\n", "hfg2=1059.9\n", "s1=1.4454\n", "sf1=0.6720\n", "sfg1=0.7734\n", "s2=2.0948\n", "sf2=0.0555\n", "sfg2=2.0393\n", "xd=(s1-sf2)/sfg2\n", "hd=hf2+xd*hfg2\n", "xa=0.3023\n", "ha=hf2+xa*hfg2\n", "wbc=0\n", "wda=0\n", "wcd=h1-hd\n", "wab=ha-hf1\n", "W=wab+wcd+wbc+wda\n", "Wrev=hfg1- (t2+459.7)*sfg1\n", "etat=(t1-t2)/(t1+459.7)\n", "eta=fur*etat\n", "#results\n", "print \"Thermal efficiency = %d percent\"%(etat*100)\n", "print \"\\n Furnace efficiency = %.1f percent\"%(eta*100)" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "## Ex:15.2 Pg:698" ] }, { "cell_type": "code", "execution_count": 2, "metadata": { "collapsed": false }, "outputs": [ { "name": "stdout", "output_type": "stream", "text": [ "Thermal efficiency = 22.8 percent\n", "\n", " Overall efficiency = 17.1 percent\n" ] } ], "source": [ "#Initialization of variables\n", "dhab=-123.1\n", "etac=0.5\n", "ha=348.5\n", "etaf=0.75\n", "eta=0.85\n", "hf=471.6\n", "hfg=731.6\n", "hc=1203.2\n", "dhcd=452.7\n", "#calculations\n", "dwabs=dhab/etac\n", "hbd=ha-dwabs\n", "dwcds=dhcd*eta\n", "dqa=hc-hbd\n", "etat=(dwcds+dwabs)/dqa\n", "eta=etat*etaf\n", "#results\n", "print \"Thermal efficiency = %.1f percent\"%(etat*100)\n", "print \"\\n Overall efficiency = %.1f percent\"%(eta*100)" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "## Ex:15.3 Pg:699" ] }, { "cell_type": "code", "execution_count": 3, "metadata": { "collapsed": false }, "outputs": [ { "name": "stdout", "output_type": "stream", "text": [ "From steam tables,\n", "Thermal efficiency = 38.4 percent\n", "\n", " Overall efficiency = 32.7 percent\n" ] } ], "source": [ "#Initialization of variables\n", "t=60 #F\n", "J=778.16\n", "p1=600 #psia\n", "p2=0.2563 #psia\n", "etaf=0.85 \n", "#calculations\n", "print \"From steam tables,\"\n", "vf=0.01604 #ft**3/lbm\n", "dw=-vf*(p1-p2)*144/J\n", "ha=28.06 #Btu/lbm\n", "hb=29.84 #Btu/lbm\n", "hd=1203.2 #Btu/lbm\n", "he=750.5 #Btu/lbm\n", "dqa=hd-hb\n", "dqr=ha-he\n", "dw=dqa+dqr\n", "dwturb=hd-he\n", "dwpump=ha-hb\n", "etat=dw/dqa\n", "eta=etat*etaf\n", "#results\n", "print \"Thermal efficiency = %.1f percent\"%(etat*100)\n", "print \"\\n Overall efficiency = %.1f percent\"%(eta*100)\n", " " ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "## Ex:15.4 Pg:699" ] }, { "cell_type": "code", "execution_count": 4, "metadata": { "collapsed": false }, "outputs": [ { "name": "stdout", "output_type": "stream", "text": [ "Thermal efficiency = 32.5 percent\n", "\n", " Overall efficiency = 27.7 percent\n" ] } ], "source": [ "#Initialization of variables\n", "dhab=-1.78\n", "etac=0.5\n", "ha=28.06\n", "eta=0.85\n", "hf=471.6\n", "hfg=731.6\n", "hd=1203.2\n", "dhcd=452.7\n", "#calculations\n", "dwabs=dhab/etac\n", "hbd=ha-dwabs\n", "dwcds=dhcd*eta\n", "dqa=hd-hbd\n", "etat=(dwcds+dwabs)/dqa\n", "eta=etat*eta\n", "#results\n", "print \"Thermal efficiency = %.1f percent\"%(etat*100)\n", "print \"\\n Overall efficiency = %.1f percent\"%(eta*100)" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "## Ex:15.5 Pg:700" ] }, { "cell_type": "code", "execution_count": 5, "metadata": { "collapsed": false }, "outputs": [ { "name": "stdout", "output_type": "stream", "text": [ "Thermal efficiency in case 1= 46.5 percent\n", "\n", " Thermal efficiency in case 1= 40.9 percent\n", "\n", " High pressure work = 187.8 Btu/lbm\n", "\n", " Low pressure work = 451.5 Btu/lbm\n", "\n", " Net work = 639.3 Btu/lbm\n" ] } ], "source": [ "#Initialization of variables\n", "sh=1.6070\n", "ph=94.8 #psia\n", "th=324 #F\n", "tr=60 #F\n", "hh=1186.2 \n", "pi=94.8 #psia\n", "hi=1399.5\n", "si=1.8265\n", "#calculations\n", "Q=hi-hh\n", "Hr=-(tr+459.7)*(si-sh)\n", "work= Q+Hr\n", "eff=work/Q\n", "Qa1=1557.5\n", "W1=637.1 \n", "etat=W1/Qa1\n", "he=1374\n", "hj=948\n", "Whp=he-hh\n", "Wlp=hi-hj\n", "Wnet=Whp+Wlp\n", "#results\n", "print \"Thermal efficiency in case 1= %.1f percent\"%(eff*100)\n", "print \"\\n Thermal efficiency in case 1= %.1f percent\"%(etat*100)\n", "print \"\\n High pressure work = %.1f Btu/lbm\"%(Whp)\n", "print \"\\n Low pressure work = %.1f Btu/lbm\"%(Wlp)\n", "print \"\\n Net work = %.1f Btu/lbm\"%(Wnet)" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "## Ex:15.6 Pg:701" ] }, { "cell_type": "code", "execution_count": 6, "metadata": { "collapsed": false }, "outputs": [ { "name": "stdout", "output_type": "stream", "text": [ "thermal efficiency = 42.6 percent\n" ] } ], "source": [ "#Initialization of variables\n", "p2=600 #psia\n", "p1=44 #psia\n", "te=486.21 #F\n", "tb=273.1 #F\n", "J=778.16\n", "p3=0.25 #psia\n", "#calculations\n", "hc=241.9\n", "hj=834.6\n", "y=1-0.805\n", "v1=0.0172\n", "v2=0.016\n", "ha=28.06\n", "hd=hc+v1*(p2-p1)*144/J\n", "hb=ha+v2*(p1-p3)*144/J\n", "hh=1374\n", "Qa=hh-hd\n", "Qr=(ha-hj)*(1-y)\n", "etat=(Qa+Qr)/Qa\n", "#results\n", "print \"thermal efficiency = %.1f percent\"%(etat*100)" ] } ], "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 }