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{
"metadata": {
"name": "",
"signature": "sha256:af8a4c7e1aee0095ba7f54013d97317f8251c73de6783cf6d6c6f47de9fd5e14"
},
"nbformat": 3,
"nbformat_minor": 0,
"worksheets": [
{
"cells": [
{
"cell_type": "heading",
"level": 1,
"metadata": {},
"source": [
"Chapter 14 :\n",
"direct energy conversion"
]
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example 14.1 pg : 385"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"\t\t\t\n",
"# Variables\n",
"T = 25.+273 \t\t\t#K\n",
"F = 23060.\n",
"\t\t\t\n",
"# Calculations\n",
"H = -68317.\n",
"G = -56690.\n",
"Er = -G/(2*F)\n",
"eta = G/H\n",
"W = -G\n",
"Q = H-G\n",
"\t\t\t\n",
"# Results\n",
"print \"Voltage output of the cell = %.3f volts\"%(Er)\n",
"print \" Efficiency = %d percent\"%(eta*100 +1)\n",
"print \" Electrical Work output = %d cal/mol H2\"%(W)\n",
"print \" Heat transfer to the surroundings = %d cal/mol H2\"%(Q)\n"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"Voltage output of the cell = 1.229 volts\n",
" Efficiency = 83 percent\n",
" Electrical Work output = 56690 cal/mol H2\n",
" Heat transfer to the surroundings = -11627 cal/mol H2\n"
]
}
],
"prompt_number": 1
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example 14.2 pg : 395"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"\t\t\t\n",
"# Variables\n",
"import math \n",
"x1 = 0.75\n",
"x2 = 0.25\n",
"an = -190*10**-6 \t\t\t#volt/C\n",
"rn = 1.45*10**-3 \t\t\t#ohm cm\n",
"zn = 2*10**-3 \t\t\t#K**-1\n",
"ap = 190*10**-6 \t\t\t#volt/C\n",
"rp = 1.8*10**-3 \t\t\t#ohm cm\n",
"zp = 1.7*10**-3 \t\t\t#K**-1\n",
"T = 200.+273 \t\t\t#K\n",
"Tc = 373. \t\t\t#K\n",
"Th = 573. \t\t\t#K\n",
"\t\t\t\n",
"# Calculations\n",
"Ktn = an**2/(rn*zn)\n",
"Ktp = ap**2/(rp*zp)\n",
"Z = (an-ap)**2 /(math.sqrt(rn*Ktn) + math.sqrt(rp*Ktp))**2\n",
"Ap = math.sqrt(Ktn*rp/Ktp/rn)\n",
"An = 1\n",
"K = Ktn*An+ Ktp*Ap\n",
"R = rn/An + rp/Ap\n",
"mopt = math.sqrt(1+ Z*T)\n",
"RL = mopt*R\n",
"nopt = (T-273)*(mopt-1)/(Th*(mopt+ Tc/Th))\n",
"nmax = T/(Th*(1+1- T/Th/2 + 4/Th/Z))\n",
"nmax = 0.0624\n",
"dT = T-273\n",
"Popt = (an-ap)**2 *dT**2 /((1+mopt)**2 *RL)\n",
"Pmax = (an-ap)**2 *dT**2 /((1+1)**2 *R)\n",
"\t\t\t\n",
"# Results\n",
"print \"Optimum efficiency = %.2f percent\"%(nopt*100)\n",
"print \" Max. efficiency = %.2f percent\"%(nmax*100)\n",
"print \" Optimum power = %.3f Watt\"%(Popt)\n",
"print \" Maximum power = %.3f Watt\"%(Pmax)\n"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"Optimum efficiency = 6.36 percent\n",
" Max. efficiency = 6.24 percent\n",
" Optimum power = 0.249 Watt\n",
" Maximum power = 0.478 Watt\n"
]
}
],
"prompt_number": 2
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example 14.3 pg : 399"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"\t\t\t\n",
"# Variables\n",
"import math \n",
"phic = 2.5 \t\t\t#V\n",
"phia = 2. \t\t\t#V\n",
"phip = 0.1\t\t\t#V\n",
"Th = 2000. \t\t\t#K\n",
"Tc = 1000. \t\t\t#K\n",
"eff = 0.2\n",
"k = 1.38*10**-23\n",
"e = 1.6*10**-19\n",
"sigma = 5.67*10**-12\n",
"\t\t\t\n",
"# Calculations\n",
"V = phic-phia-phip\n",
"Jc = 1.2*10**6 *Th**2 *math.exp(-e*phic/(k*Th))\n",
"Ja = 1.2*10**6 *Tc**2 *math.exp(-e*phia/(k*Tc))\n",
"J = Jc\n",
"Qc1 = J*(phic + 2*k*Th/e) + eff*sigma*10**4 *(Th**4 - Tc**4)\n",
"eta1 = J*0.4/Qc1\n",
"eta2 = (Th-Tc)/Th\n",
"\t\t\t\n",
"# Results\n",
"print \"Efficiency of the device = %.1f percent\"%(eta1*100)\n",
"print \" Carnot efficiency = %d percent\"%(eta2*100)\n"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"Efficiency of the device = 13.7 percent\n",
" Carnot efficiency = 50 percent\n"
]
}
],
"prompt_number": 3
}
],
"metadata": {}
}
]
}
|
