In: Mechanical Engineering
Problem 4.084 SI A rigid copper tank, initially containing 1.5 m3 of air at 295 K, 4 bar, is connected by a valve to a large supply line carrying air at 295 K, 15 bar. The valve is opened only as long as required to fill the tank with air to a pressure of 15 bar. Finally, the air in the tank is at 320 K. The copper tank, which has a mass of 20 kg, is at the same temperature as the air in the tank, initially and finally. The specific heat of the copper is c = 0.385 kJ/kg · K. Assuming ideal gas behavior for the air, determine: (a) the initial and final mass of air within the tank, each in kg, and (b) the heat transfer to the air and copper tank from the surroundings, in kJ, ignoring kinetic and potential energy effects.