diff options
author | Jovina Dsouza | 2014-06-18 12:43:07 +0530 |
---|---|---|
committer | Jovina Dsouza | 2014-06-18 12:43:07 +0530 |
commit | 206d0358703aa05d5d7315900fe1d054c2817ddc (patch) | |
tree | f2403e29f3aded0caf7a2434ea50dd507f6545e2 /Basic_Principles_And_Calculations_In_Chemical_Engineering/ch22.ipynb | |
parent | c6f0d6aeb95beaf41e4b679e78bb42c4ffe45a40 (diff) | |
download | Python-Textbook-Companions-206d0358703aa05d5d7315900fe1d054c2817ddc.tar.gz Python-Textbook-Companions-206d0358703aa05d5d7315900fe1d054c2817ddc.tar.bz2 Python-Textbook-Companions-206d0358703aa05d5d7315900fe1d054c2817ddc.zip |
adding book
Diffstat (limited to 'Basic_Principles_And_Calculations_In_Chemical_Engineering/ch22.ipynb')
-rw-r--r-- | Basic_Principles_And_Calculations_In_Chemical_Engineering/ch22.ipynb | 292 |
1 files changed, 292 insertions, 0 deletions
diff --git a/Basic_Principles_And_Calculations_In_Chemical_Engineering/ch22.ipynb b/Basic_Principles_And_Calculations_In_Chemical_Engineering/ch22.ipynb new file mode 100644 index 00000000..01acfa93 --- /dev/null +++ b/Basic_Principles_And_Calculations_In_Chemical_Engineering/ch22.ipynb @@ -0,0 +1,292 @@ +{ + "metadata": { + "name": "" + }, + "nbformat": 3, + "nbformat_minor": 0, + "worksheets": [ + { + "cells": [ + { + "cell_type": "heading", + "level": 1, + "metadata": {}, + "source": [ + "Chapter 22 : Introduction to Energy Balances for Process without Reaction" + ] + }, + { + "cell_type": "heading", + "level": 3, + "metadata": {}, + "source": [ + " Example 22.1 page no. 651\n" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "# Application of the energy balance to a closed system\n", + "\n", + "# Variables\n", + "#Assume that properties of water can be used to substitute properties of solution\n", + "# Given\n", + "V = 1.673 ;\t\t\t# Volume of closed vessel-[cubic metre]\n", + "m = 1. ;\t\t\t# mass of saturated liquid vaporized-[kg]\n", + "Pi = 1. ;\t\t\t# Initial pressure -[atm]\n", + "Ti = 10. ;\t\t\t# Initial temperature -[degree C]\n", + "Pf = 1. ;\t\t\t# final pressure -[atm]\n", + "Tf = 100. ;\t\t\t# final temperature -[degree C]\n", + "\n", + "# Use steam table to obtain additional information at given condition\n", + "Ui = 35. ;\t\t\t# Initial enthalpy-[kJ/kg]\n", + "Uf = 2506.0 ;\t\t\t# Final enthalpy -[kJ/kg]\n", + "\n", + "# Calculations\n", + "# Use eqn. 22.2 after modifiying it using given conditions(W = 0,del_KE = 0 and del_PE = 0 )\n", + "Q = m*(Uf - Ui) ;\t\t\t# Heat transferred to the vessel - [kJ]\n", + "\n", + "# Results\n", + "print 'Heat transferred to the vessel is %.1f kJ . '%Q\n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Heat transferred to the vessel is 2471.0 kJ . \n" + ] + } + ], + "prompt_number": 1 + }, + { + "cell_type": "heading", + "level": 3, + "metadata": {}, + "source": [ + "Example 22.2 page no. 652\n" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "# Calculation of U using American engineering units\n", + "\n", + "# Variables\n", + "# Given\n", + "T1 = 80. ;\t\t\t# Initial temperature -[degree F]\n", + "T1 = 40. ;\t\t\t# final temperature -[degree F]\n", + "\n", + "# Additional data obtained from steam table at given temperatures and corresponding vapour pressures\n", + "p1 = 0.5067 ;\t\t\t# Initial saturation pressure-[psia]\n", + "p2 = 0.1217 ;\t\t\t# Final saturation pressure-[psia]\n", + "V1 = 0.01607 ;\t\t\t# Initial specific volume - [cubic feet/lb]\n", + "V2 = 0.01602 ;\t\t\t# Final specific volume - [cubic feet/lb]\n", + "H1 = 48.02 ;\t\t\t#Initial specific enthalpy -[Btu/lb]\n", + "H2 = 8.05 ;\t\t\t# Final specific enthalpy -[Btu/lb]\n", + "\n", + "# Calculations\n", + "del_P = p2 - p1 ;\t\t\t# Change in pressure -[psia]\n", + "del_V = V2 - V1 ;\t\t\t# Change in specific volume -[cubic feet/lb]\n", + "del_H = H2 - H1 ;\t\t\t# Change in specific enthalpy -[Btu/lb]\n", + "del_pV = p2*144*V2/778. - p1*144*V1/778. ;\t\t\t# Change in pv-[Btu]\n", + "del_U = del_H - del_pV ;\t\t\t# Change in specific internal energy - [Btu/lb]\n", + "del_E = del_U ;\t\t\t# Change in specific total energy(since KE=0,PE=0 and W=0) -[Btu/lb]\n", + "\n", + "# Results\n", + "print 'Change in pressure is %.3f psia . '%del_P\n", + "print 'Change in specific volume is %.5f cubic feet/lb (negligible value) . '%del_V\n", + "print 'Change in specific enthalpy is %.2f Btu/lb . '%del_H\n", + "print 'Change in specific internal energy is %.2f Btu/lb . '%del_U\n", + "print 'Change in specific total energy is %.2f Btu/lb . '%del_E\n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Change in pressure is -0.385 psia . \n", + "Change in specific volume is -0.00005 cubic feet/lb (negligible value) . \n", + "Change in specific enthalpy is -39.97 Btu/lb . \n", + "Change in specific internal energy is -39.97 Btu/lb . \n", + "Change in specific total energy is -39.97 Btu/lb . \n" + ] + } + ], + "prompt_number": 2 + }, + { + "cell_type": "heading", + "level": 3, + "metadata": {}, + "source": [ + " Example 22.3 page no. 662\n" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "# use of the general energy balance to analyze an open , unsteady-state system\n", + "\n", + "# Variables\n", + "#Lets take tank to be system\n", + "# Given\n", + "T = 600. ; \t\t\t# Temperature of steam -[K]\n", + "P = 1000. ;\t\t\t# Pressure of steam -[kPa]\n", + "\n", + "# Calculations\n", + "# Additional data for steam obtained from CD database at T and P\n", + "U = 2837.73 ;\t\t\t# Specific internal energy-[kJ/kg]\n", + "H = 3109.44 ;\t\t\t# Specific enthalpy -[kJ/kg]\n", + "V = 0.271 ;\t\t\t# Specific volume -[cubic metre/kg]\n", + "# By the reduced equation \n", + "Ut2 = H ;\t\t\t# Internal energy at final temperature-[kJ/kg]\n", + "\n", + "# Results\n", + "print 'The specific internal energy at final temperature is %.2f kJ/kg. Now use two properties\\\n", + "of the steam (P = %i kPa and Ut2 = %.2f kJ/kg) to find final temperature (T) from steam table. \\\n", + "From steam table we get T = 764 K.'%(Ut2,P,Ut2)\n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "The specific internal energy at final temperature is 3109.44 kJ/kg. Now use two propertiesof the steam (P = 1000 kPa and Ut2 = 3109.44 kJ/kg) to find final temperature (T) from steam table. From steam table we get T = 764 K.\n" + ] + } + ], + "prompt_number": 3 + }, + { + "cell_type": "heading", + "level": 3, + "metadata": {}, + "source": [ + " Example 22.4 page no. 669\n" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "# application of the energy balance to a open, steady-state system, a heat exchanger\n", + "\n", + "# Variables\n", + "# Take milk plus water in tank to be system\n", + "# Given\n", + "T1_water = 70. ;\t\t\t# Temperature of entering water -[degree C]\n", + "T2_water = 35. ;\t\t\t# Temperature of exiting water -[degree C]\n", + "T1_milk = 15. ;\t\t\t#Temperature of entering milk -[degree C]\n", + "T2_milk = 25. ;\t\t\t#Temperature of exiting milk -[degree C]\n", + "\n", + "# Get additional data from steam table for water and milk,assuming milk to have same properties as that of water.\n", + "H_15 = 62.01 ;\t\t\t#Change in specific internal energy-[kJ/kg]\n", + "H_25 = 103.86 ;\t\t\t#Change in specific internal energy-[kJ/kg]\n", + "H_35 = 146.69 ;\t\t\t#Change in specific internal energy-[kJ/kg]\n", + "H_70 = 293.10 ;\t\t\t#Change in specific internal energy-[kJ/kg]\n", + "\n", + "# Assumptions to simplify Equation 22.8 are:\n", + "print 'Assumptions to simplify Equation 22.8 are:'\n", + "print '1. Change in KE and PE of system = 0.'\n", + "print '2. Q = 0 ,because of way we picked the system,it is is well insulated.'\n", + "print '3. W = 0,work done by or on the system.'\n", + "\n", + "# Calculations\n", + "#Basis m_milk = 1 kg/min , to directly get the answer .\n", + "m_milk = 1 ;\t\t\t# Mass flow rate of milk-[kg/min]\n", + "# By applying above assumtions eqn. 22.8 reduces to del_H = 0 .Using it get m_water-\n", + "m_water = (m_milk*(H_15 - H_25))/(H_35 - H_70) ; \t\t\t# Mass flow rate of water-[kg/min]\n", + "m_ratio = m_water/m_milk ;\t\t\t# Mass flow rate of water per kg/min of milk-[kg/min]\n", + "\n", + "# Results\n", + "print 'Mass flow rate of water per kg/min of milk is %.2f (kg water/min )/(kg milk/min).'%m_ratio\n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Assumptions to simplify Equation 22.8 are:\n", + "1. Change in KE and PE of system = 0.\n", + "2. Q = 0 ,because of way we picked the system,it is is well insulated.\n", + "3. W = 0,work done by or on the system.\n", + "Mass flow rate of water per kg/min of milk is 0.29 (kg water/min )/(kg milk/min).\n" + ] + } + ], + "prompt_number": 4 + }, + { + "cell_type": "heading", + "level": 3, + "metadata": {}, + "source": [ + " Example 22.5 page no. 670\n" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "# Calculation of power needed to pump water in an open, steady state system\n", + "\n", + "# Variables\n", + "# Take pipe between initial and final level of water\n", + "# Given\n", + "h_in = -20. ;\t\t\t# Depth of water below ground-[ft]\n", + "h_out = 5. ;\t\t\t# Height of water level above ground-[ft]\n", + "h = h_out - h_in ;\t\t\t# Total height to which water is pumped-[ft]\n", + "V = 0.50 ;\t\t\t# Volume flow rate of water - [cubic feet/s]\n", + "ef = 100.; \t\t\t# Efficiency of pump - [%] \n", + "g = 32.2; \t\t\t# Acceleration due to gravity -[ft/square second] \n", + "gc = 32.2 ;\t\t\t#[(ft*lbm)/(second square*lbf)]\n", + "\n", + "M = V * 62.4 ;\t\t\t# mass flow rate - [lbm/s]\n", + "PE_in = 0 ;\t\t\t# Treating initial water level to be reference level\n", + "\n", + "# Calculations\n", + "PE_out = (M*g*h*1.055)/(gc*778.2) ;\t\t\t# PE of discharged water -[lbm*(square feet/square second)]\n", + "W = PE_out - PE_in ;\t\t\t#Work done on system = power delivered by pump, (since we are using mass flow rate and pump efficiency is 100 % , so W = Power) -[kW]\n", + "\n", + "# Results\n", + "print 'The electric power required by the pump is %.2f kW. '%W\n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "The electric power required by the pump is 1.06 kW. \n" + ] + } + ], + "prompt_number": 5 + }, + { + "cell_type": "code", + "collapsed": true, + "input": [], + "language": "python", + "metadata": {}, + "outputs": [] + } + ], + "metadata": {} + } + ] +}
\ No newline at end of file |