5 Bananas are to be cooled from 24 to 13C at a rate of 215 k

5 Bananas are to be cooled from 24 to 13°C at a rate of 215 kg/h by a refrigeration system. The power input to the refrigerator is 1.4 kW. Determine the rate of cooling, in kJ/min, and the COP of the refrigerator. The specific heat of banana above freezing is 3.35 kJ/kg. oC.

Solution

Given mass flow rate is m = 215 kg / hr = 215/60 kg/ min = 3.58 kg /min

Heat rejection is Q = m cp (t2 - t1 )

Q = 3.58 x 3.35 ( 24-13)

Q = 132.045 kj / min

Q = 2.20 kj / sec

COP of the cycle is

COP = 2.20/1.4

COP = 1.57