{ "cells": [ { "cell_type": "markdown", "metadata": {}, "source": [ "# Chapter 22:Practical Air Treatment Cycles" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "# Example 22.1,PAGE NUMBER:270" ] }, { "cell_type": "code", "execution_count": 1, "metadata": { "collapsed": false }, "outputs": [ { "name": "stdout", "output_type": "stream", "text": [ "The amount of water to be evaporated is 4e-04 kg/(s kW)\n" ] } ], "source": [ "# Variable declaration\n", "T_d=37;# The dry bulb temperature of air in °C\n", "H=24;# % saturation\n", "n_s=75;# Saturation efficiency in %\n", "h=62.67;# The entering enthalpy in kJ/kg\n", "\n", "# Calculation\n", "# By construction on the chart, or from tables, the ultimate saturation condition would be 21.5°C, and 75% of the drop from 37°C to 21.5°C gives a fi nal dry bulb of 25.4°C.\n", "h_fg=2425;# The average latent heat of water over the working range in kJ/kg\n", "q=(h_fg)**-1;# The amount of water to be evaporated in kg/(s kW)\n", "print\"The amount of water to be evaporated is %0.0e kg/(s kW)\"%q" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "## Example 22.2,PAGE NUMBER:271" ] }, { "cell_type": "code", "execution_count": 2, "metadata": { "collapsed": false }, "outputs": [ { "name": "stdout", "output_type": "stream", "text": [ "\n", "The dry bulb temperature (final)=27.7°C (point D , Figure 22.4b )\n", "\n", "The wet bulb is now 18.9°C and the enthalpy is 53 kJ/kg.\n" ] } ], "source": [ "# Variable declaration\n", "T_d=37;# The dry bulb temperature of air in °C\n", "T_w=25.4;# The cooling temperature of water in °C\n", "cf=0.80;# Contact factor\n", "\n", "# Calculation\n", "T_df=T_d-(cf*(T_d-T_w));# The dry bulb temperature (final) in °C\n", "print\"\\nThe dry bulb temperature (final)=%2.1f°C (point D , Figure 22.4b )\"%T_df\n", "print\"\\nThe wet bulb is now 18.9°C and the enthalpy is 53 kJ/kg.\"" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "## Example 22.3,PAGE NUMBER:271" ] }, { "cell_type": "code", "execution_count": 3, "metadata": { "collapsed": false }, "outputs": [ { "name": "stdout", "output_type": "stream", "text": [ "\n", "Heat from water=21 kJ/kg \n", "Enthalpy of entering air=57.1 kJ/kg \n", "Enthalpy of leaving air=78.1 kJ/kg\n", "From the chart, the air leaves at approximately 25.7°C dry bulb.\n" ] } ], "source": [ "# Variable declaration\n", "T_d=26;# The dry bulb temperature of air in °C\n", "T_w=20;# The wet bulb temperature of water in °C\n", "T_win=29;# The temperature of water at inlet in °C\n", "T_wout=24;# The temperature of water at outlet in °C\n", "C_pw=4.187;# The specific heat capacity of water in kJ/kg.K\n", "\n", "# Calculation\n", "Q=C_pw*(T_win-T_wout);# Heat from water in kJ/kg\n", "h_ain=57.1;# Enthalpy of entering air in kJ/kg\n", "h_aout=78.1;# Enthalpy of leaving air in kJ/kg\n", "print\"\\nHeat from water=%2.0f kJ/kg \\nEnthalpy of entering air=57.1 kJ/kg \\nEnthalpy of leaving air=78.1 kJ/kg\"%Q\n", "print\"From the chart, the air leaves at approximately 25.7°C dry bulb.\"" ] } ], "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": "2.7.11" } }, "nbformat": 4, "nbformat_minor": 0 }