Avapor-compression refrigeration cycle with f-12 as the working fluid has condenser inlet conditions if 200 psi, 230 f and evaporator exit conditions of 20 psi, 10 f. the freon leaves the condenser at 110 f. mass flow rate is 5 lbm/s. a) calculate the actual compressor power (horsepower) b) calculate the actual cooling rate in tons. c) find the temperature at the evaporator inlet. d) calculate compressor efficiency.

Air is to be cooled in the evaporator section of a refrigerator by passing it over a bank of 0.8-cm-outer-diameter and 0.4-m-long tubes inside which the refrigerant is evaporating at -20°c. air approaches the tube bank in the normal direction at 0°c and 1 atm with a mean velocity of 4 m/s. the tubes are arranged in-line with longitudinal and transverse pitches of sl- st 1.5 cm. there are 30 rows in the flow direction with 15 tubes in each row. determine (a) the refrigeration capacity of this system and (b) pressure drop across the tube bank. evaluate the air properties at an assumed mean temperature of -5°c and 1 atm. is this a good assumption?

Which one from below is not one of the reasons of planning failures? (clo3) a)-planner is careless. b-planner spend less time in the field but more time on the desk c)-planner is not qualified d)-planner does not have sufficient time to properly plan

Aquick transition of the operating speed of a shaft from its critical speed will whirl amplitude. (a) increase (b) limit (c) not affect (d) zero