Question

PROBLEM 3 (40 A closed rigid tank contains 1 kg of ammonia and undergoes a constant specific volume process The initial pressure is 5 bar, initial temperature is 20 "C, and final pressure is 2 bar, please: (a) Draw the T-, diagram and locate the initial state (State l) in the T-v diagram; (5%) (b) Read the pertinent Table to find the specific volume, in mkg, and specific internal energy, in (c) Determine the specific volume, in mkg, of final state (State 2) and locate the final state (State 2) ofthe initial state (State Tk (656) in the T-r diagram (66) (d) Read the pertinent Table to the temperature, in °C at final state (State 2); (5%) (c) Determine the quality, x, fr final state (State 2k (4%) (f) Determine the specific internal energy, kng, offinal state (State 2); (6%) (g) Calculate the mindheat tnsfe-ing the process, e in k. (95) s) and equation(s) a) b) Page 6 of 7

Answer 1

Given that m = 1 kg, p_1 = 5 bar, T_1 = 20 degree p_2 = 2 bar, u_2 = u_1 b) from the label u_1 = 0.26949 mj/kg v_1 = 1353.32 KJ/kg } super loaded start c) v_2 = v_1 = 0.2649m^3/kg, saturated region d) at 2 layer V_2 = 1.507 times 10^-3 + x_2(0.5940) => x_2 = 0.4507 T_2 = -18.86 degree e) x_2 = 0.4507 f) u_2 = 93.50 + 0.4507(1300.39 - 93.5) u_2 = 637.44KJ/kg g) h_1 = 1488.06 KJ/kg h-2 = 93.8 + 0.4507(1325.51 - 93.80) = 648.93 KJ/kg Q = (h_1- h_2)m = Q = (1488.06 - 648.93) = 840 KJ => Q = 840 KJ