Mechanical Engineering - Heat Transfer, Refrigeration and Air Conditioning - Discussion

Discussion Forum : Heat Transfer, Refrigeration and Air Conditioning - Section 7 (Q.No. 46)
46.
In actual air-conditioning applications for R-12 and R-22, and operating at a condenser temperature of 40° C and an evaporator temperature of 5° C, the heat rejection factor is about
1
1.25
2.15
5.12
Answer: Option
Explanation:
No answer description is available. Let's discuss.
Discussion:
13 comments Page 1 of 2.

Vivek mishra said:   1 decade ago
Heat rejection factor = (Heat rejected/Heat absorbed).

Here, COP = 7.942.

Implies, Q(rejected) = 1.12*Q (absorbed).

Hence, HRF = 1.12.

Hafiz said:   10 years ago
How COP = 7.92 and HRF = 1.12? Please explain.

Dhiraj mehta said:   9 years ago
COP = t2/(t1 - t2) where t2 is low temperature.

HRF = 1 + (1/cop).

Vijay said:   8 years ago
COP = 278k/35k = 7.94.
HRF = 1 +1/COP.

Anurup said:   8 years ago
According to me, it comes 1.126.

DURGESH KUMAR DUBEY said:   8 years ago
Heat rejection factor:- 1+ 1/COP.

It will be 1.126.

Shibunath said:   7 years ago
Actually, the answer should come 1.125.
Cop: 7.94.
HRF: 1+(1/cop).

Chra said:   7 years ago
T1=5+273=278 k.
T2=40+273=313 k.
(COP)R = T1/(T2-T1) = 7.94.
HRF = 1+( 1/COP) = 1.135.

Paul said:   7 years ago
The Answer should be 1.125

Himmat said:   7 years ago
Please Give a clear explanation.


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