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The compressor in a refrigerator takes R-134a in at 100 kPa, −20°C and then compresses it to 1 MPa, 40°C. With the room temperature at 20°C find the minimum compressor work.

The compressor in a refrigerator takes R-134a in at 100 kPa, −20°C and then compresses it to 1 MPa, 40°C. With the room temperature at 20°C find the minimum compressor work. Correct Answer -48.19 kJ/kg

w(c) = h1 – h2 + q(rev) w(min) = h1 – h2 + To(s2 – s1) = 387.22 – 420.25 + 293.15 × (1.7148 – 1.7665) = -48.19 kJ/kg.

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