{ "metadata": { "name": "" }, "nbformat": 3, "nbformat_minor": 0, "worksheets": [ { "cells": [ { "cell_type": "heading", "level": 1, "metadata": {}, "source": [ "Chapter 14 : Real Gases Compressiblity" ] }, { "cell_type": "heading", "level": 3, "metadata": {}, "source": [ " Example 14.1 Page No. 442\n" ] }, { "cell_type": "code", "collapsed": false, "input": [ "# Variables\n", "T1f = 125. ;\t\t\t# Temperature of NH3 -[degree F] \n", "T1 = 460. +T1f ;\t\t\t# Temperature NH3 -[degree Rankine] \n", "Pg = 292. ;\t\t\t# Pressure of NH3 -[psig]\n", "Pa = Pg+14.7 ;\t\t\t#Pressure of NH3 -[psia]\n", "R = 10.73 ;\t\t\t#Universal gas constant-[(psia*cubic feet)/(lb mol*R)]\n", "mw_NH3 = 17. ;\t\t# Molecular wt. 1 lb mol NH3-[lb]\n", "n = 1/17. ;\t\t\t#[mol]\n", "V_tank = 120. ;\t\t# Volume of tank-[cubic feet]\n", "\n", "# Calculations\n", "V_id = (n*R*T1)/Pa ;\t# Specific volume of NH3 treating it ideal gas-[cubic feet/lb]\n", "Tc = 729.9 ;\t\t\t#[degree R]\n", "Pc = 1636. ;\t\t\t#[psia]\n", "Tr = T1/Tc;\n", "Pr = Pa/Pc;\n", "\n", "z_real = 0.855;\n", "z_ideal = 1.;\n", "V_real = V_id*z_real/z_ideal;\t\t\t# Specific volume of NH3 treating it real gas-[cubic feet/lb]\n", "NH3 = V_tank/V_real ;\t\t\t # Actual amt. of NH3 in tank-[lb]\n", "\n", "# Results\n", "print 'Actual amt. of NH3 in tank is %.0f lb. Therefore , boss is wrong.'%NH3\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Actual amt. of NH3 in tank is 117 lb. Therefore , boss is wrong.\n" ] } ], "prompt_number": 4 }, { "cell_type": "heading", "level": 3, "metadata": {}, "source": [ " Example 14.2 Page No. 444\n" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "# Variables\n", "Tc = 154.4 ;\t\t\t#[K]\n", "Pc1 = 49.7 ;\t\t\t# [atm]\n", "Pc = 101.3 * Pc1;\t\t#[kPa]\n", "\n", "T_O21 = -25 ;\t\t\t# Temperature-[degree C]\n", "T_O2 = 273+T_O21;\t\t#Temperature -[K]\n", "R = 8.134 ;\t\t\t # gas constant-[(cubic metre * kPa)/(kg mol * K)]\n", "V_tank = 0.0284 ;\t\t# Volume of tank-[cubic metre]\n", "mol_O2 = 32 ;\t\t\t# Kmol. wt. of O2-[kg]\n", "m_O2 = 3.5 ;\t\t\t# Mass of liquid O2-[kg]\n", "\n", "# Calculations\n", "V_sp = V_tank * mol_O2/m_O2 ;\t\t\t# Specific molar volume-[m**3/kg]\n", "Vc = R * Tc/Pc ;\t\t\t # [cubic metre/kg mol]\n", "Vr = V_sp/Vc;\n", "Tr = T_O2/Tc;\n", "\n", "Pr = 1.43 ;\t\t\t# [kPa]\n", "P_O2 = Pr * Pc ;\t# The pressure in the tank -[kPa]\n", "\n", "# Results\n", "print 'The pressure in the tank is %.2f kPa.'%P_O2\n", "\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The pressure in the tank is 7199.49 kPa.\n" ] } ], "prompt_number": 5 }, { "cell_type": "heading", "level": 3, "metadata": {}, "source": [ " Example 14.3 Page No. 448\n" ] }, { "cell_type": "code", "collapsed": false, "input": [ "# Variables\n", "Tc = 100. ;\t\t\t# Temperature -[degree C] \n", "T = 273 +Tc ;\t# Temperature -[K] \n", "P = 90. ;\t\t# Pressure [atm]\n", "R = 82.06 ;\t\t\t# gas constant-[(cubic centimetre * atm)/(g mol * K)]\n", "Y_CH4 = 20./100 ;\t\t\t# [mole fraction]\n", "Y_C2H4 = 30./100 ;\t\t\t# [mole fraction]\n", "Y_N2 = 50./100 ;\t\t\t#[mole fraction]\n", "\n", "#Additional information from appendix D\n", "Tc_CH4 = 191. ;\t\t\t#[K]\n", "Pc_CH4 = 45.8 ;\t\t\t# [atm]\n", "Tc_C2H4 = 283. ;\t\t#[K]\n", "Pc_C2H4 = 50.5 ;\t\t# [atm]\n", "Tc_N2 = 126. ;\t\t\t#[K]\n", "Pc_N2 = 33.5 ;\t\t\t# [atm]\n", "\n", "# Calculations & Results\n", "#(a)-Ideal gas law\n", "V_sp1 = R * T/P ;\t\t\t# Molar volume-[cubic centimetre/g mol]\n", " \n", "print '(a) The volume per mole of mixture by ideal gas law is %.1f cubic centimetre/g mol.'%V_sp1\n", "\n", "\t\t\t#(b)\n", "Pc_mix = Pc_CH4 * Y_CH4+Pc_C2H4 * Y_C2H4+Pc_N2 * Y_N2;\t\t\t# [atm]\n", "Tc_mix = Tc_CH4 * Y_CH4+Tc_C2H4 * Y_C2H4+Tc_N2 * Y_N2 ;\t\t\t# [K]\n", "Pr_mix = P/Pc_mix;\n", "Tr_mix = T/Tc_mix;\n", "\t\t\t# With 2 parameters(Pr_mix and Tr_mix) , you can find from figure 14.4b that z * Tr_mix = 1.91\n", "z = 1.91/Tr_mix;\n", "V_sp2 = z * R * T/P ;\t\t\t# Molar volume-[cubic centimetre/g mol]\n", "print '(b) The volume per mole of mixture by treating it to be real gas is %.1f cubic centimetre/g mol.'%V_sp2\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "(a) The volume per mole of mixture by ideal gas law is 340.1 cubic centimetre/g mol.\n", "(b) The volume per mole of mixture by treating it to be real gas is 324.1 cubic centimetre/g mol.\n" ] } ], "prompt_number": 6 }, { "cell_type": "code", "collapsed": true, "input": [], "language": "python", "metadata": {}, "outputs": [] } ], "metadata": {} } ] }