Saturated steam at a gauge pressure of 2.0 bar will be used to heat a stream of ethane. the latter enters a heat exchanger at 16 ° c with a gauge pressure of 1.5 bar at a rate of 795 m3 / min and is heated to constant pressure up to 93 ° c. the water vapor condenses and leaves the exchanger as liquid at 27 ° c. the specific enthalpy of ethane at the given pressure is 941 kj / kg at 16 ° c and 1,073 kj / kg at 93 ° c. a) how much energy should be transferred to ethane to heat it from 16 ° c to 93 ° c? b) assuming that all the energy transferred from the steam is used to heat the ethane, how much vapor in m3 / s should be supplied to the exchanger?

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.

Refrigerant 134a enters an insulated compressor operating at steady state as saturated vapor at -26°c with a volumetric flow rate of 0.18 m3/s. refrigerant exits at 9 bar, 70°c. changes in kinetic and potential energy from inlet to exit can be ignored. determine the volumetric flow rate at the exit, in m3/s, and the compressor power, in kw.

The higher the astm grain size number, the finer the gran is. a)-true b)-false