An air conditioner using refrigerant-134a as the working fluid and operating on the ideal vapor-compression refrigeration cycle
is to maintain a space at 22°C while operating its condenser at 1000 kPa. Determine the COP of the system when a temperature difference of 2°C is allowed for the transfer of heat in the evaporator.
2 answers:
Answer:
COP = 13.31
Explanation:
We have an allowed temperature difference of 2°C, thus, let's make use of temperature of 20°C in the evaporator.
Now, looking at table A-11 i have attached and looking at temperature of 20°C, we will see that the enthalpy(h1) = 261.59 Kj/Kg
While the enthropy(s1) = 0.92234 Kj/KgK
Now, the enthalpy at the second state will be gotten from the given condenser pressure under the condition s2 = s1.
Thus, looking at table A-13 which i have attached, direct 20°C is not there, so when we interpolate between the enthalpy values at 15.71°C and 21.55°C, we get an enthalpy of 273.18 Kj/Kg.
Now, the enthalpy at the third and fourth states is again obtained from interpolation between values at temperatures of 18.73 and 21.55 of the saturated liquid value in table A-12 i have attached.
Thus, h3=h4 = 107.34 Kj/kg
Formula for COP = QL/w = (h1- h4) / (h2 - h1)
COP = (261.59 - 107.34)/( 273.18 - 261.59) = 13.31
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string name[5];
int age[5];
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for ( i = 0; i<=4; i++ ) {
cout << "Please enter student's name:";
cin >> name[i];
cout << "Please enter student's age:";
cin >> age[i];
}
for (i=0;i<=4;i++){
cout<<"Age of "<< name[i]<<" is "<<age[i]<<endl;
}
}
Output of above program is displayed in figure attached.
