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{
"metadata": {
"name": "",
"signature": "sha256:86e00f67d619987b1a4198153e70d431ddb0592847bf75b0bc55b544e7c1f8d2"
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"worksheets": [
{
"cells": [
{
"cell_type": "heading",
"level": 1,
"metadata": {},
"source": [
"Chapter 8 - Availability of Energy"
]
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example 1 - Pg 120"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"#calculate the available energy loss\n",
"#Initialization of variables\n",
"q=1000. #Btu\n",
"th=1140. #F\n",
"tl=40. #F\n",
"ts=940. #F\n",
"#calculations\n",
"Q1=q*(th-tl)/(th+460)\n",
"Q2=q*(ts-tl)/(ts+460)\n",
"dif=Q1-Q2\n",
"#results\n",
"print '%s %d %s' %(\"Available energy loss =\",dif,\"Btu\")\n"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"Available energy loss = 44 Btu\n"
]
}
],
"prompt_number": 2
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example 2 - Pg 124"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"#calculate the untransferred, transferred, available, unavailable energy for both gas and water\n",
"#Initialization of variables\n",
"import math\n",
"ma=200000. #lb\n",
"cpa=0.26\n",
"T2g=1200. #F\n",
"T1g=300. #F\n",
"T1w=200. #F\n",
"mw=250000. #lb\n",
"cpw=1.02\n",
"Tl=560. #R\n",
"cx=1.01\n",
"#calculations\n",
"T2w=T1w+ ma*cpa*(T2g-T1g)/(mw*cpw)\n",
"Qun=Tl*ma*cpa*math.log((T2g+460)/(T1g+460))\n",
"Qtr=ma*cpa*(T2g-T1g)\n",
"Qav=Qtr-Qun\n",
"Qun2=Tl*mw*cx*math.log((T2w+460)/(T1w+460))\n",
"Qav2=Qtr-Qun2\n",
"ht1=Qav-Qav2\n",
"#results\n",
"print '%s %d %s' %(\"For gas, Untransferred energy =\",Qun,\"Btu/hr\")\n",
"print '%s %d %s' %(\"\\n For gas, transferred energy =\",Qtr,\"Btu/hr\")\n",
"print '%s %d %s' %(\"\\n For gas, available energy =\",Qav,\"Btu/hr\")\n",
"print '%s %d %s' %(\"\\n For water, Untransferred energy =\",Qun2,\"Btu/hr\")\n",
"print '%s %d %s' %(\"\\n For water, available energy =\",Qav2,\" Btu/hr\")\n",
"print '%s %d %s' %(\"\\n Loss of available energy =\",ht1,\"Btu/hr\")\n",
"print '%s' %('The answers are a bit different due to rounding off error in textbook')\n"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"For gas, Untransferred energy = 22750129 Btu/hr\n",
"\n",
" For gas, transferred energy = 46800000 Btu/hr\n",
"\n",
" For gas, available energy = 24049870 Btu/hr\n",
"\n",
" For water, Untransferred energy = 34693187 Btu/hr\n",
"\n",
" For water, available energy = 12106812 Btu/hr\n",
"\n",
" Loss of available energy = 11943058 Btu/hr\n",
"The answers are a bit different due to rounding off error in textbook\n"
]
}
],
"prompt_number": 3
}
],
"metadata": {}
}
]
}
|
