Steam at a constant temperature of 32C condenses in the condenser of a powerplant at a rate of 0.60 kg/s by circulating 10C cooling water through a bank of 5 m long, 1.2 cm ID thin-walled copper tubes. Water enters the tubes at a mean velocity of 4 m/s, and leaves at a temperature of 24C. Assume the tubes are isothermal. Consider the following:i)Determine the average heat transfer coefficient (W/m2C) between the water and the tubes. ii)Calculate the number of tubes required to achieve the indicated heat transfer rate in the condenser.

Amass of m 1.5 kg of steam is contained in a closed rigid container. initially the pressure and temperature of the steam are: p 1.5 mpa and t 240°c (superheated state), respectively. then the temperature drops to t2= 100°c as the result of heat transfer to the surroundings. determine: a) quality of the steam at the end of the process, b) heat transfer with the surroundings. for: p1.5 mpa and t 240°c: enthalpy of superheated vapour is 2900 kj/kg, specific volume of superheated vapour is 0. 1483 m/kg, while for t 100°c: enthalpy of saturated liquid water is 419kj/kg, specific volume of saturated liquid water is 0.001043m/kg, enthalpy of saturated vapour is 2676 kj/kg, specific volume of saturated vapour is 1.672 m/kg and pressure is 0.1 mpa.

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

The temperature of air decreases as it is compressed by an adiabatic compressor. a)- true b)- false