Ashell-and-tube heat exchanger is used for heating 15 kg/s of oil (cp = 2.0 kj/kg · k) from 20°c to 46°c. the heat exchanger has one shell pass and six tube passes. water enters the shell side at 85°c and leaves at 65°c. the overall heat transfer coefficient is estimated to be 1000 w/m2 · k. calculate the rate of heat transfer and the heat transfer area.

Refrigerant-134a enters the compressor of a refrigerator as superheated vapor at 0.14 mpa and -10°c at a rate of 0.05 ka/s and leaves at 0.8 mpa and 50°c. the refrigerant is cooied in the condenser to 0.72 mpa and 26'c. it is then throttled to 0.15 mpa. sketch the t-s diagram for the system and evaluate: 6) the rate of heat removai from the refrigerated space (kw), it) the power input to the compressor (kw), ii) the isentropic efficiency of the compressor (%), and iv) the cop of the refrigerator.