ME 3333 Chapter : Homework 5 Solutions Fall 2012
Document Summary
T = 120 k, p = 0. 8 mpa. P = 200 kpa, v = 0. 12 m3/kg. => x = undefined and we find the state in table b. 6. 2. T ~ 32. 5 c = 30 + (40 30) (0. 12 0. 11889)/(0. 12335 - 0. 11889) u = 403. 1 + (411. 04 403. 1) 0. 24888 = 405. 07 kj/kg. A rigid tank holds 0. 75 kg ammonia at 70 c as saturated vapor. The tank is now cooled to 20 c by heat transfer to the ambient. Determine the amount of work and heat transfer during the process. Process: rigid tank v = c => v = constant & 1w2 = . : u2 u1 = 1q2 1w2 = 1q2, State 1: v1 = 0. 03787 m3/kg, u1 = 1338. 9 kj/kg. State 2: t, v => two-phase (straight down in. V x2 = (v vf)/vfg = (0. 03787 0. 001638)/0. 14758 = 0. 2455 u2 = uf + x2 ufg = 272. 89 + 0. 2455 1059. 3 = 532. 95 kj/kg.
