{ "metadata": { "name": "", "signature": "sha256:2235c937260175b0ab97c5358d9d0f83ecc788771c1f725849b19d038912d334" }, "nbformat": 3, "nbformat_minor": 0, "worksheets": [ { "cells": [ { "cell_type": "heading", "level": 1, "metadata": {}, "source": [ "Chapter01:Fundamental of Energy - Science and Technology" ] }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Ex1.1:pg-36" ] }, { "cell_type": "code", "collapsed": false, "input": [ "# Given data:\n", "T1=500+273.0 #source temp in kelvin \n", "T2=100+273.0 #sink temperature in kelvin\n", "W=1 # output power in kW\n", "\n", "nth=1-(T2/T1) # thermal efficiency\n", "\n", "Q1=1/nth # heat supplied in kW\n", "\n", "Q2=Q1-W # heat rejected in kW\n", "\n", "print \" The heat rejected is \",Q2,\"kW\"\n", "\n", "# the answer in book is wrong due to incorrect value of T1 " ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ " The heat rejected is 0.9325 kW\n" ] } ], "prompt_number": 7 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Ex1.2:pg-37" ] }, { "cell_type": "code", "collapsed": false, "input": [ "# Given data:\n", "T1=40+273.0 # ambient temp in kelvin\n", "T2=-10+273.0 # freezer temp in kelvin\n", "Q2=2 # heat loss rate for freezer in kJ/s\n", "\n", "Q1=T1*(Q2/T2) # heat transfer rate in kJ/s\n", "\n", "W=Q1-Q2 # work in kW\n", "\n", "print \"The least power required is \",round(W,2),\"kW\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The least power required is 0.38 kW\n" ] } ], "prompt_number": 14 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Ex1.3:pg-37" ] }, { "cell_type": "code", "collapsed": false, "input": [ "# Given data:\n", "Q1=3e4 # heat required in kJ/h\n", "W=2e3 # work required in kJ/h\n", "\n", "Q2=Q1-W # heat abstracted from outside in kJ/h\n", "\n", "COP=Q1/(Q1-Q2) # COP of heat pump\n", "\n", "print \"Heat abstracted from outside air is \",Q2,\"kJ/h\"\n", "print \"COP heat pump is \",COP\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Heat abstracted from outside air is 28000.0 kJ/h\n", "COP het pump is 15.0\n" ] } ], "prompt_number": 16 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Ex1.4:pg-38" ] }, { "cell_type": "code", "collapsed": false, "input": [ "# Given data:\n", "T11=320+273.0 # temp at source 1 in kelvin\n", "Q1=10000.0 # heat transfer rate at source 1 in kJ/min\n", "T12=65+273.0 # temp at source 2 in kelvin\n", "Q2=120000.0 # heat transfer rate at source 2 in kJ/min\n", "T2=35+273.0 # temp of surrounding in kelvin\n", "\n", "n1=1-(T2/T11) # efficiency by source 1\n", "n2=1-(T2/T12) # efficiency by source 2\n", "\n", "W1=Q1*n1 # work at source 1 in kJ/min\n", "W2=Q2*n2 # work at source 2 in kJ/min\n", "\n", "print \"The work done at two sources is W1=\",W1,\" kJ/min W2=\",W2,\"kJ/min\"\n", "print \"The larger power is provided by source 2\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The work done at two sources is W1= 4806.07082631 kJ/min W2= 10650.887574 kJ/min\n", "The larger power is provided by source 2\n" ] } ], "prompt_number": 17 } ], "metadata": {} } ] }