{ "metadata": { "name": "", "signature": "sha256:d49c3ebbe462c89b25518f64eebe9040738bf2ef82ee8e4dec85ee0229afc06b" }, "nbformat": 3, "nbformat_minor": 0, "worksheets": [ { "cells": [ { "cell_type": "heading", "level": 1, "metadata": {}, "source": [ "Chapter 15 - Vapor cycles and processes" ] }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 1 - Pg 276" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#calculate the Thermal efficiency and Furnace efficiency\n", "#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 '%s' %(\"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)*100\n", "eta=fur*etat\n", "#results\n", "print '%s %d %s' %(\"Thermal efficiency =\",etat,\"percent\")\n", "print '%s %.1f %s' %(\"\\n Furnace efficiency =\",eta,\" percent\")\n", "\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "from steam tables,\n", "Thermal efficiency = 45 percent\n", "\n", " Furnace efficiency = 33.8 percent\n" ] } ], "prompt_number": 1 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 2 - Pg 277" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#calculate the Thermal and Overall efficiency\n", "#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*100.\n", "eta=etat*etaf\n", "#results\n", "print '%s %.1f %s' %(\"Thermal efficiency =\",etat,\" percent\")\n", "print '%s %.1f %s' %(\"\\n Overall efficiency = \",eta,\" percent\")\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Thermal efficiency = 22.8 percent\n", "\n", " Overall efficiency = 17.1 percent\n" ] } ], "prompt_number": 2 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 3 - Pg 277" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#calculate the Thermal and Overall efficiency\n", "#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 '%s' %(\"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*100.\n", "eta=etat*etaf\n", "#results\n", "print '%s %.1f %s' %(\"Thermal efficiency =\",etat,\" percent\")\n", "print '%s %.1f %s' %(\"\\n Overall efficiency =\",eta,\"percent\")\n", " \n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "From steam tables,\n", "Thermal efficiency = 38.4 percent\n", "\n", " Overall efficiency = 32.7 percent\n" ] } ], "prompt_number": 3 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 4 - Pg 278" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#calculate the Thermal and Overall efficiency\n", "#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*100.\n", "eta=etat*eta\n", "#results\n", "print '%s %.1f %s' %(\"Thermal efficiency =\",etat,\"percent\")\n", "print '%s %.1f %s' %(\"\\n Overall efficiency =\",eta,\"percent\")\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Thermal efficiency = 32.5 percent\n", "\n", " Overall efficiency = 27.7 percent\n" ] } ], "prompt_number": 4 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 5 - Pg 287" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#calculate the thermal efficiency\n", "#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*100.\n", "#results\n", "print '%s %.1f %s' %(\"thermal efficiency =\",etat,\"percent\")\n", "\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "thermal efficiency = 42.6 percent\n" ] } ], "prompt_number": 5 } ], "metadata": {} } ] }