Refrigerant-134a at 1 mpa and 90°c is to be cooled to 1 mpa and 30°c in a condenser by air. the air enters at 100 kpa and 27°c with a volume flow rate of 640 m3/min and leaves at 95 kpa and 60°c. determine the mass flow rate of the refrigerant. the gas constant of air is 0.287 kpa·m3/kg·k. the constant pressure specific heat of air is cp = 1.005 kj/kg·°c. the enthalpies of the r-134a at the inlet and the exit states are 324.66 kj/kg and 93.58 kj/kg.

Two technicians are discussing the intake air temperature (iat) sensor. technician a says that the computer uses the iat sensor as a backup to the engine coolant temperature (ect) sensor. technician b says that the powertrain control module (pcm) will subtract the calculated amount of fuel if the air measures hot. who is correct

Carbon dioxide gas expands isotherm a turbine from 1 mpa, 500 k at 200 kpa. assuming the ideal gas model and neglecting the kinetic and potential energies, determine the change in entropy, heat transfer and work for each kilogram of co2.

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.