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{
"cells": [
{
"cell_type": "heading",
"level": 1,
"metadata": {},
"source": [
"Chapter10-Air conditioning\n"
]
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Ex1-pg293"
]
},
{
"cell_type": "code",
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"input": [
"import math\n",
"## Example 10.1\n",
"print('Example 10.1\\n\\n');\n",
"print('Page No. 293\\n\\n');\n",
"\n",
"## given\n",
"m = 1.;## mass flow rate of initial air mixture in kg/s\n",
"T = 23.5;## Initial temperature in degree celcius\n",
"m1 = 0.6;## Percentage of fresh air mixture\n",
"T1 = 5.;## Dry Bulb Temperature of fresh air in degree celcius\n",
"w1 = 0.005;## Humidity of fresh air at temperature T1 in kg/kg\n",
"m2 = 0.4;## Percentage of recirculated air mixture\n",
"T2 = 25.;## Dry Bulb Temperature of recirculated air in degree celcius\n",
"w2 = 0.015;## Humidity of recirculated air at temperature T2 in kg/kg\n",
"\n",
"##In air conditioning => m1*w1 + m2*w2 = m*w\n",
"w = (m1*w1 + m2*w2)/m;## in kg/kgs\n",
"print'%s %.2f %s'%('The humidity of the air mixture is ',w,' kg/kg \\n')\n",
"\n",
"##The specific enthalpy in J/kg can be calculated by the formula => h = (1.005*10^3*T) +(w*((2.50*10^6)+(1.86*10^3*T))); where the T is the temperature and w is the humidity at temperature T\n",
"h_f = (1.005*10**3*T1) +(w1*((2.50*10**6)+(1.86*10**3*T1)));## Specific enthalpy of fresh air in J/kg\n",
"h_r = (1.005*10**3*T2) +(w2*((2.50*10**6)+(1.86*10**3*T2)));## Specific enthalpy of recirculated air in J/kg\n",
"h_m = (1.005*10**3*T) +(w*((2.50*10**6)+(1.86*10**3*T)));## Specific enthalpy of final air mixture in J/kg\n",
"\n",
"h_t = (m1*h_f) + (m2*h_r);## Total enthalpy of initial air mixturein J/kg\n",
"Q = m*(h_m - h_t);## in Watts\n",
"print'%s %.2f %s'%('The load on the heater is ',Q,' W')\n",
"## Deviation in answer due to direct substitution and some approximation in answer in book\n",
"\n"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"Example 10.1\n",
"\n",
"\n",
"Page No. 293\n",
"\n",
"\n",
"The humidity of the air mixture is 0.01 kg/kg \n",
"\n",
"The load on the heater is 10638.99 W\n"
]
}
],
"prompt_number": 1
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Ex2-pg298"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"import math\n",
"## Example 10.2\n",
"print('Example 10.2\\n\\n');\n",
"print('Page No. 298\\n\\n');\n",
"\n",
"## given\n",
"m1 = 0.75;## Percentage of fresh air mixture\n",
"T1 = 31.;## Dry Bulb Temperature of fresh air in degree celcius\n",
"w1 = 0.0140;## Humidity of fresh air at temperature T1 in kg/kg\n",
"m2 = 0.75;## Percentage of recirculated air mixture\n",
"T2 = 22.;## Dry Bulb Temperature of recirculated air in degree celcius\n",
"w2 = 0.0080;## Humidity of recirculated air at temperature T2 in kg/kg\n",
"m = 1.50;## mass flow rate of final air mixture in kg/s\n",
"T = 10.;## Dew Point temperature in degree celcius\n",
"\n",
"##In air conditioning => m1*w1 + m2*w2 = m*w\n",
"w = (m1*w1 + m2*w2)/m## in kg/kgs\n",
"print'%s %.2f %s'%('The humidity of the air mixture is ',w,' kg/kg \\n')\n",
"\n",
"\n",
"## from the psychrometric chart, at w = 0.011kg/kg, the dry bulb temperature is = 26.5 degree celcius also the humidity of saturated air at 10 degree celcius is 0.0075kg/kg\n",
"T_w = 26.5;## Dry Bulb temerature in degree celcius\n",
"w_10 = 0.0075;## humidity at temperatue T in kg/kg\n",
"\n",
"##the specific enthalpy in J/kg can be calculated by the formula => h = (1.005*10^3*T) +(w*((2.50*10^6)+(1.87*10^3*T))); where the T is the temperature and w is the humidity at temperature T\n",
"\n",
"h_a = (1.005*10**3*T_w) +(w*((2.50*10**6)+(1.88*10**3*T_w)));## Specific enthalpy of recirculated air in J/kg\n",
"h_s = (1.005*10**3*T) +(w_10*((2.50*10**6)+(1.87*10**3*T)));## Specific enthalpy of saturated air at 10 degree celcius in J/kg\n",
"\n",
"Q = m*(h_a - h_s);## in Watts\n",
"print'%s %.2f %s'%('The cooling load on the washer is ',Q,' W')\n",
"## Answer wrongly calculated in the book\n"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"Example 10.2\n",
"\n",
"\n",
"Page No. 298\n",
"\n",
"\n",
"The humidity of the air mixture is 0.01 kg/kg \n",
"\n",
"The cooling load on the washer is 38610.41 W\n"
]
}
],
"prompt_number": 2
}
],
"metadata": {}
}
]
}