2001 The Effect of Nozzle Locaton on the Concentraton Profles n Chemcal Addton Tank,,, 305-353 150, dsk block, CFD FLUENT 5, Abstract A numercal analyss of the flow and necton characterstcs s performed for the flow feld created by water nected nto a cylndrcal tank wth an ntally statonary flud The flow s relevant to the operaton of the chemcal addton system n the chemcal and volume control system (CVCS) of nuclear power plants Ths study s performed to mprove the current desgn whch has a dsk block nsde tank The numercal analyss for the flow and necton characterstcs n chemcal addton tank are carred out usng CFD code FLUENT 5 Results show that the nlet nozzle nstalled n tangental drecton at the uppermost regon of the tank cylnder and the outlet nozzle located at the center of the tank bottom s very effectve n enhancng the necton n the tank 1 1,,, 314-701 182
, [1] (dssolved oxygen), ph (CVCS, Chemcal and Volume Control System) (CAS, Chemcal Addton System) (VCT, Volume Control Tank) (oxdzng speces) 656 1211 (hydrazne, N 2 H 4 ), ph L 7 ( -7) (LOHH 2 O) 1996 dsk block [2] dsk block / dsk block 4 dsk block, 2 1, 416 10-2 m 3, (H/D) 2 03 m,, 126 10-4 m 3 /s [2] dsk block, ase 1) (Fg 1), case 2) 1/4 (Fg 1), case 3) 1/4 (Fg 1(c)), case 4) (Fg 1(d))
(t<0), 1 t=0 0 ( ), Reynolds 3,900 Case 1 3,, [3] ρ t + ( ρu ) = 0 p τ ( ρ u ) + ( ρuu ) = + + ρg (2) t ( ρ ma ) + ( ρuma ) = J A, (3) t ρ u p m,, (1) τ J,,, A u u τ = µ ( + ) (4) ma J A, = ρ DA, m (5) D A, m (mxture) A 0096 m/s, (no-slp condton) CFD FLUENT 5 2 (second-order backward mplct Euler method)
, (frst-order upwnd scheme), (segregated) SIMPLE,, (mesh adapton), 12 03-06, 08 10-3, 3,000-5,000, 10-15 4 (PWR, Pressurzed Water Reactor) (CSTR, Contnuous Strred-Tank Reactor) [4] win C = CIN + ( CO CIN ) exp( t) (6) W, t=, (sec) TANK C IN =, (kg/kg) C O =, (kg/kg) w IN =, (kg/s) W TANK =, (kg) 100 Table 1 Fg 2 ( ) 1 Fg 2 case 1 1 70% dsk block (6) [2], case 4 dsk block
Fg 3 case1 1 1/6, 1/2 5/6, Case 1, case 1 dsk block, Fg 2 case 2, 3 4 case 1, Fg 4, 5 6 case 2, 3 4 5 1/6, 1/2 5/6, case 2, 3 4 case 4 case 4 H/D Fg 7 H/D 1, 2 4 1 H/D 5, CFD FLUENT 5 case 1), case 2) 1/4, case 3) 1/4, case 4),,,
6 (1) EPRI, "PWR prmary water chemstry gudelnes, Rev3", TR-105714, 1995 (2) Chang, KS, and Park, BH, "A numercal study on mxng characterstcs of the chemcal necton tank", Journal of the Korean Nuclear Socety, Vol 29, No 1, 1997, pp 38-67 (3) "FLUENT 5 User's Gude", Fluent Inc, 1998 (4) Brd, RB, Stewart, WE and Lghtfoot, EN, "Transport phenomena", Wley, New York, 1960 (5) Patankar, SV, "Numercal heat transfer and flud flow", McGraw-Hll, New York, 1980 (6) Versteeg, HK, and Malalasekera, W, "An Introducton to Computatonal Flud Dynamcs - The Fnte Volume Method", Longman Scentfc & Techncal, 1995 (7) Van Sonsbeek, HM, van Verlaan, P and Tramper, J, "Hydrodynamcs, mxng, and oxygen transfer n lqud-mpelled loop reactors", Inter Chem E Symposum 121(1990) 259-268 (8) Yoo, GJ, and So, RMC, "Varable densty effects on axsymmetrc sudden-expanson flows", Inter J Heat Mass Transfer 32(1989) 105-120 Table 1 Normalzed average speces concentraton for varous tme (t=5 mn) (t=10 mn) (t=15 mn) (t=20 mn) Case 1 0959 0932 0906 0881 Case 2 0600 0347 0195 0106 Case 3 0607 0354 0201 0111 Case 4 0489 0225 0099 0042 10 08 Case 1 Cave/Co 06 04 CSTR Eq Case 2&3 02 Case 4 (c) (d) 000 10 20 30 40 50 60 Tme (mn) Fg1 Inlet/outlet nozzle locaton for each case Fg 2 Tme dependent normalzed average speces concentraton for varous case
085 075 082 067 085 069 056 085 065 053 085 074 059 069 054 085 006 059 061 062 025 070 054 053 062 053 056 062 048 Fg 3 Contours of concentraton at the cross secton for case 1 (tme=60mn) Fg 4 Contours of concentraton at the cross secton for case 2 (tme = 5 mn) 043 077 043 049 012 057 054 057 040 078 059 070 054 040 041 056 061 043 059 074 048 049 056 049 Fg 5 Contours of concentraton at the cross secton for case 3 (tme=5mn) Fg 6 Contours of concentraton at the cross secton for case 4 (tme = 5 mn) 10 Cave/Co 08 06 H/D=4 04 H/D=1 H/D=2 02 00 0 10 20 053 053 051 054 049 053 30 Tme (mn) 40 50 60 Fg 7 Tme dependent normalzed average speces concentraton for varous geometres (case 4)