1259 AM 0 94 KT OO Done thermo prac chapter5pdf any such cyc
Solution
Solution 5.63
We know that COP is equal to the ratio of desired effect to the work input in a refrigeration cycle.
COP = 4.5 given
Input given, Q= 0.8KW
COP= Desired effect/ input given
= Q1/Q
4.5 = Q1/Q
Q1= 0.8 x 4.5
=3.6KW
= Q1/(Q2-Q1) as Q1+Q = Q2
4.5 = 3.6/(Q2-3.6)
Q2= 4.4 KW ans.
T1, ambient temp= 20 C = 273+20=293 K
T2, condenser temperature = 28 C= 273+28 = 301 K
T3 = evaporator temperature = ?
COP in terms of temperature can be given as
COP = T3/(T2-T3)
i.e, 4.5 = T3 / (301-T3)
So,
4.5x(301-T3) = T3
T3 = 246.27 K ans.
This is the lowest possible temp. in the given refrigerator which will be at the evaporator.
I would surely suggest to utilize every bit of power available to the maximum extent we can.
Solution 5.63
We know that COP is equal to the ratio of desired effect to the work input in a refrigeration cycle.
COP = 4.5 given
Input given, Q= 0.8KW
COP= Desired effect/ input given
= Q1/Q
4.5 = Q1/Q
Q1= 0.8 x 4.5
=3.6KW
= Q1/(Q2-Q1) as Q1+Q = Q2
4.5 = 3.6/(Q2-3.6)
Q2= 4.4 KW ans.
T1, ambient temp= 20 C = 273+20=293 K
T2, condenser temperature = 28 C= 273+28 = 301 K
T3 = evaporator temperature = ?
COP in terms of temperature can be given as
COP = T3/(T2-T3)
i.e, 4.5 = T3 / (301-T3)
So,
4.5x(301-T3) = T3
T3 = 246.27 K ans.
This is the lowest possible temp. in the given refrigerator which will be at the evaporator.
I would surely suggest to utilize every bit of power available to the maximum extent we can.
Solution 5.63
We know that COP is equal to the ratio of desired effect to the work input in a refrigeration cycle.
COP = 4.5 given
Input given, Q= 0.8KW
COP= Desired effect/ input given
= Q1/Q
4.5 = Q1/Q
Q1= 0.8 x 4.5
=3.6KW
= Q1/(Q2-Q1) as Q1+Q = Q2
4.5 = 3.6/(Q2-3.6)
Q2= 4.4 KW ans.
T1, ambient temp= 20 C = 273+20=293 K
T2, condenser temperature = 28 C= 273+28 = 301 K
T3 = evaporator temperature = ?
COP in terms of temperature can be given as
COP = T3/(T2-T3)
i.e, 4.5 = T3 / (301-T3)
So,
4.5x(301-T3) = T3
T3 = 246.27 K ans.
This is the lowest possible temp. in the given refrigerator which will be at the evaporator.
I would surely suggest to utilize every bit of power available to the maximum extent we can.
Solution 5.63
We know that COP is equal to the ratio of desired effect to the work input in a refrigeration cycle.
COP = 4.5 given
Input given, Q= 0.8KW
COP= Desired effect/ input given
= Q1/Q
4.5 = Q1/Q
Q1= 0.8 x 4.5
=3.6KW
= Q1/(Q2-Q1) as Q1+Q = Q2
4.5 = 3.6/(Q2-3.6)
Q2= 4.4 KW ans.
T1, ambient temp= 20 C = 273+20=293 K
T2, condenser temperature = 28 C= 273+28 = 301 K
T3 = evaporator temperature = ?
COP in terms of temperature can be given as
COP = T3/(T2-T3)
i.e, 4.5 = T3 / (301-T3)
So,
4.5x(301-T3) = T3
T3 = 246.27 K ans.
This is the lowest possible temp. in the given refrigerator which will be at the evaporator.
I would surely suggest to utilize every bit of power available to the maximum extent we can.



