Okay here\'s the deal with this: This question will get graded tomorrow so whoev

Question

Okay here's the deal with this: This question will get graded tomorrow so whoever puts the right answer I will award points to. Doesn't matter what order, I need it to be nice , neat, and most importantly correct.

A commercial refrigerator with R-134a as the working fluid is used to keep a refrigerated space at -30 degrees celcius by providing 352 kW of refrigeration and rejecting waste heat to the outdoor air, which is 37 degrees celcius. The R-134a enteres the compressor at a rate of 2.75 kg/s, where it is compressed from 200 kPa to 1.0 mPa. The compressor is estimated to gain 450W of heat from the surroundings. Determine:

a. the actual COP

b. if this refrgerator is reasonable (show evidence)

Explanation / Answer

T(L)=243k

T(H)=310k

for compressor,

at pressure=200kpa(saturates state)

from R-134a table,h1=392kj/kg

at pressure 1Mpa(superheated state)

h2=451kj/kg

steady flow equ,Q-W=m(h2-h1)

450-w=2.75(451-392)

w=287.75 kj/kg

COP=q/w=352/287.75=1.22 ans

since fof good performance of referegrator COP should be in the range of 3

hence this referegerator is not reasonable on the basis of performance

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