1 body - 4 pipes and 104 pipes per passage (each with a diameter of 2.6 cm, 4 m per passage A thin wall heat exchanger) will be used to heat the air. Water pipes to 8 kg / h at 350 K temperature With mass flow, air enters the body at 15 C with a mass flow of 18 kg / s. Over time, inside the pipe The pollution factor of the formed sediment is 0.0026 m2K / W. The transport coefficients on the inner and outer surfaces of the pipes are 450 and 200 W / m2K is estimated. Using specific temperatures at 25 C for air and water a-) The effectiveness of the heat exchanger by drawing the shape of the problem, b-) Heat transfer rate (kW), c-) Calculate the outlet temperatures (C) of the water and air and show the temperatures in the T_L diagram.

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 flowing streams of argon gas are adiabatically mixed to form a single flow/stream. one stream is 1.5 kg/s at 400 kpa and 200 c while the second stream is 2kg/s at 500 kpa and 100 ? . it is stated that the exit state of the mixed single flow of argon gas is 150 c and 300 kpa. assuming there is no work output or input during the mixing process, does this process violate either the first or the second law or both? explain and state all your assumptions.

Acompressor receives the shaft work to decrease the pressure of the fluid. a)- true b)- false