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"name": "",
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"worksheets": [
{
"cells": [
{
"cell_type": "heading",
"level": 1,
"metadata": {},
"source": [
"Chapter 6 : Head Engines - The Second Law of Thermodynamics"
]
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example 6.1 Page No : 148"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"\t\t\t\n",
"# Variables\n",
"Q1 = 300. \t\t\t#kJ \t\t\t#heat supplied at the boiler\n",
"Wt = 100. \t\t\t#kJ \t\t\t#work output of turbine\n",
"Wp = 0.5 \t\t\t#kJ \t\t\t#work input to pump\n",
"\n",
"\t\t\t\n",
"# Calculations and Results\n",
"Q2 = Q1 - (Wt - Wp) \t\t\t#kJ \t\t\t#heat rejected at the condensor\n",
"print \"Heat rejected at the condensor = %.1f kJ\"%(Q2);\n",
"efficiency = 1 - (Q2/Q1)\n",
"print \"The thermal efficiency of plant = %.2f \"%(efficiency)\n"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"Heat rejected at the condensor = 200.5 kJ\n",
"The thermal efficiency of plant = 0.33 \n"
]
}
],
"prompt_number": 1
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example 6.2 Page No : 153"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"\t\t\t\n",
"# Variables\n",
"COP_ref = 4 \t\t\t#COP of refrigerator\n",
"Q1 = 0.5 \t\t\t#kJ/s \t\t\t#rate of heat transfer at the condensor\n",
"\n",
"\t\t\t\n",
"# Calculations and Results\n",
"#Part(a)\n",
"print \"Parta\";\n",
"Wc = Q1/(COP_ref+1) \t\t\t#kJ/s \t\t\t#Power input to compressor\n",
"Q2 = COP_ref*Wc \t\t\t#kJ/s \t\t\t#Rate of heat transfer in evaporator\n",
"print \"Rate of heat transfer in evaporator = %.1f kJ/s\"%(Q2)\n",
"print \"Power input to compressor = %.1f kJ/s\"%(Wc)\n",
"\n",
"#Part(b)\n",
"print \"Partb\";\n",
"COP_hp = 1 + COP_ref \t\t\t#COP of heat pump\n",
"print \"COP of heat pump = %.0f\"%(COP_hp)\n"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"Parta\n",
"Rate of heat transfer in evaporator = 0.4 kJ/s\n",
"Power input to compressor = 0.1 kJ/s\n",
"Partb\n",
"COP of heat pump = 5\n"
]
}
],
"prompt_number": 1
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example 6.3 Page No : 154"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"\n",
"#Part(a)\n",
"print \"Part a\";\n",
"I = 4.5 \t\t\t#Amp \t\t\t#Current drawn\n",
"V = 220 \t\t\t#V\n",
"Electricity_consumption = I*V \t\t\t#Watts\n",
"ElectricityUnitPerDay = Electricity_consumption/1000*8 \t\t\t#kWh\n",
"MonthlyBill_part_a = ElectricityUnitPerDay * 5 * 30\n",
"print \"The additional monthly electricity bill = Rs. %.2f\"%(MonthlyBill_part_a);\n",
"\n",
"#Part(b)\n",
"print \"Part b\";\n",
"Q1 = Electricity_consumption*.001 \t\t\t#kW \t\t\t#Rate of heat transfer from heat pump\n",
"COP_hp = 4 \t\t\t#COP of heat pump\n",
"W = Q1/COP_hp \t\t\t#kW \t\t\t#rate at which energy is consumed\n",
"ElectricityUnitPerDay = W*8\n",
"MonthlyBill_part_b = ElectricityUnitPerDay * 5 * 30\n",
"print \"Saving in monthly electricity bill = Rs. %.2f\"%(MonthlyBill_part_a - MonthlyBill_part_b)\n"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"Part a\n",
"The additional monthly electricity bill = Rs. 1188.00\n",
"Part b\n",
"Saving in monthly electricity bill = Rs. 891.00\n"
]
}
],
"prompt_number": 3
}
],
"metadata": {}
}
]
}
|
