b 38 wb 5 M 9 f F p Vol.38, No.5 201 A 5 ψ JOURNAL OF ENGINEERING THERMOPHYIC May, 201 NaCl wflψgy ]y ~rzffωm ρ ffi μ χ flßff fiον (Hfi^-Pok» 8sV&fiJBd~}ff±Hfi 10049) ffl fi p0ψls Λ!8]μTE ±qp0xm]zruνb ΨffΞßBiffr5p0ß.=+$ O=(K) ]Kzffi3.±!ffiU?+$ O=[$]!e?fi±z ffir5p0!8=p0kg]-~xmξ$uhmyffi r5p0~}!±q NaCl jπr5p0]p0ß.kgffi~}zrξzrwr±r5p0]p0ß.fir5&fi'k)v»]&pu&pωfi> Π8,m'Dm]&PuR]Ωfi!em&P±p0ß.OtßR]±b.EW&PU?[ßKΞ bj[ p0ωr5p0ß.ωnacl jπω!em» `od: TK124 ΞY s: A Wd: 0253 231X(201)05 1024 05 Experimental Investigation on Flash peed of NaCl olution in Circulatory Flash Vaporization WANG Yu HE Qi YU Long-Wen YAN Jun-Jie (tate Key Laboratory of Multiphase Flow in Power Engineering, Xi an Jiaotong University, Xi an 10049, China) Abstract Flash vaporization is the key technology of lots of industrial processes. The research on the intensity of flash vaporization has great significance. In present paper, circulatory flash speed was defined as the average decreasing rate of non-equilibrium fraction during residence time inside flash chamber, which described the superheating energy consumed in unit time and represented the true intensity of circulatory flash vaporization. And an experimental rig for circulatory flash vaporization was designed and set up to carry out study on circulatory flash speed of NaCl solution circulatory flash. Results suggested that circulatory flash speed increased with the increasing of circulating flow rate and equilibrium pressure. Thicker water film and higher concentration of working fluids yielded smaller circulatory flash speed. Moreover, circulatory flash speed decreased rapidly at the initial stage, then increased with the increases of superheat degree and became flat eventually. Key words flash vaporization; circulatory flash speed; NaCl solution; superheat degree 0 ffi XCοChL" Ξ(3a»(!`οN@l pffl &u 4o<ΠΞ(Z = ChL" Jfl<ψdL"ΠY8Ξ(vwvψ %Π1wO ff/r. Ξ(@l@vL[ QY5<o/Λ οnß# Dd^fl?QΞ ffi$hπνß ffl οkr ψπk"νw2 [1,2] $D [3]? ρd9fl [4] ^Λffiso/ΞΦΞtμνJο lπ Zo/ <q4o/&n"o/λn"o /Φo/QY <οdλπ2 'Ξflo/Ξ( = J(L"Jfl<~ChL"T>AaNZa J(L" 2ψΛflGΠn"o/6<o/ QYyq?vcΛtV<±@ νmw1ffl < m'ο?ff <οo/dλπq4o/ ο avuφ201-01-20; vuφ201-04-21 o/ξ<νjοl J!ΠN %d" Ξ@ lfl2 o//vff^d n$hffn"o/μ5 P "Λ Miyatake ^ [5,6] pj(@l 40 80 C? 3 5 K ψdl :<Fν Ξo/jffl} yqπ #hω'j(@0&'j(»λ'j(» NEF Φ±fiDffΨ-»Πψ1o/jf qlλffis NEF ff Nfl2ρ+ΠZo/ <±ο/vff62 /vρfianλgopalakrishna ^ [] pfν&cl< 3.5%wν Ξo/jffl} yqλ} ψ<π ψdl< 0.5 10 CΠΞ= @l< 25 80 CΠ ΞΩl< 165, 305 & 45 mmλ#fl?n"o/ /v:ff DffΨ} μλλaury ^ [8] = Ξ hlπtφfijpb o=h (No.51436006±No.51306148); fijbd=azrw(ff1nix: (No.2015CB251504) ikφ8 ffi (1993 )±;±&±zrx±g I r5p0 f4lfi.ofi»3zrξ ± Φ x c±ffi± Email:yanjj@mail.xjtu.edu.cn
5 M 8 ffi: NaCljΠr5p0]p0ß.~}zr 1025 Ωl< 15 mmπ= @l< 30 5 CΠψdl< 1 35 K Fνn"o/' fl} yqπaury h <Ξ ψd>ff^*νo//r TddΛQRΠ #fl?fl/v:ffffψdl4n } μλλ# yqflu[ο-po/ WΛdflψ5Πflhψ dllπt>/v:ffc/'flλfath ^ [9] p'b o/i0jffl»66@yqπ#hωflo/u^ -ff(ffo/u ^flλdflψ5π%oψdlπo /ψ4>π;2%b»?*# N 'Ωo/U ^-ΛCipollna ^ LXfl} Ωρ6 rbo/ [10] I0#, 'J(@0V<^--»(ffo/jf qlλdflψ5π'j(@0ffψdl&λπfi E» %OtQ ΠffΞΩl %Ot%OΛYan ^ pffyqflfν n"o/ffq4o/πhω flq4o/ *# NΠ#X fl0± DdD: [11] Gρ6cΛZhang ^ [12],ψ±flb%ΛflΛΠ5p Ξ9u[ο-Πyqfl'.o/ο- Fν& NaCl iξn"o/π#hωn"o/ο-<±ο/va n'j(» Jyfl2-ΛZhang ^ [13] pfνq 4o/ 'J($hjffl} yqλ} dfl?πq4o/?π'j(»ff%ff&j(u %OtQ ΠffΞΩl%Ot%OΛ Qrffi Πgpo/yq ψ<πr, 'J(@0 'J(»&o/U^-ff(ffo/ jf qlλvφπpοq4o/πq4 :! o/u< *# NμTΠ#Yo/Ξ<%ο& o/ud» '. :#6*# NJ!0fiΛ9 -»Dxy q4o/,3wlλοahω q4o/ο-<*# N<'J(» Jyfl2 -Π#tGLXflq4o/} ψλp'.ψdl q4%ff = ΞΩl J(u?= ΞC ll q4o/ο-' flyqλ 1 ~K2flvμ q4} I0k4 1 ffiξπfflωnfif 9) Fq49) /RflB9)&ΠHfl9)ΛFq4 9)fflΩBΞο Fq4ρ ν6ekdp g J O%ffG o/u?9νflpλo/avw!fq 49)< o/u<λo/ψ<:1woff/rπ /RflB9)fflΩ±fiν Λ8dPΠν<<flB νλ/rflb-:9zbξο<λ!gψ<πflb ν,ψ:ff%ffgπ }.[flbν :ff% -ΛΠHfl9)` <, ψ<π/r':j l, ρλ o/uφq4o/ *UΠN;K< 0.1 m (3) 0.1 m ( ) 0.48 m(ω)π-ρ4< fi2e ΠΠ+χ<μ/I % ΛNρfi4 @3fflχΠ Qso/ψ<dff flzλo/uj?π5p y< 25 mmλo/ug*kμ P100 xudφpπ ffp.o/ψ<j(u Λo/Uj?ΠffK μ5p 2 mm T cdefπ ffm.j?π@lλ 5 1 ~}J1ΠΨ5 Fig. 1 chematic of experimental system 2 ~effiflλg 2.1 Φfx }q ^ffi 9ΠCrn*!yqo/ ψ<πr ' J(@0 'J(»?o/U^-V<LLχΠ Rψflo/2(jf qlλvφπ!q4o /ψ<π ο'. Φ)ULΠq4 :!o/ U< *# N'.Π+χ'>,}y?o / WlΛ, Yan ^ [11] '? *# NGρ} xλn<ξ< *# N τ &νj%ο u Gρ} xkl τ = L u u = Q BH (1) (2) N<ΠQ <q4%ffπb L H "Φo/U l 3l &Ξ = ΩlΛ 4 2 'Ξfl'. ΦLΠq4 :!o/u< *# NΛ }?Π!'. ΦLΠ*# N0 fi`oλ<flg@*# N WΠοAZq4o / o/ο-hω<*# N<Π'J(» NEF Jyfl2-, ψξq4o/jf WlΠkΛ (3)
1026 8 e E ffl o 38 w ffiξ: CF = NEF in NEF out τ (3) N<ΠNEF in <o/ujπ 'J(»ΠNEF in = *< 1ΛNEF out Φo/U?Π'J(»ΠNEF out = T out T sat j±)νψξ< = ΔT out ΔT in ΛflG CF CF = 1 NEF out τ (4) 5 2 (/ ΨMr5 ;"p0v=]+$ O Fig. 2 Residence time of working fluids inside flash chamber under various experimental conditions 2.2 Φfx }q Xecp 4 3 'Ξfl'.q4%ff Q LΠo/ο- CF ffo/ulπψdl ΔT fl2ρ+λh4 3 < }?ΠXJ(u P e ΠΞ= Ωl H 0 Π= C l f m?o/ulπψdl ΔT :*hπq4o /ο-ffq4%ff %Ot%OΛ+Φ οq4% ff%oy8o/ξ<νj%ο%oπ%wo/ξ < cjπ %fflkwψπoz%wo/ V Π flgo/ο-%oλ 4 4 fl?fl'.j(u P e Lq4o/ο-ff o/ulπψdl ΔT fl2ρ+λdflψ5πx Nχ-» :'flπψdl±h ΠffMJ(u %OΠo/ο-%OΛ!U.ψdlLΠJ(u yωpfflmjlo/uq4 : @lryλy 8Ξ( ψ4) Q Π. Π@lyΩQ2Td Q Π%W % vψlλflgπj(u %OΠ [o/wl'yπo/ο-%oλ '.= ΞΩlLq4o/ο-ffψdl fl2ρ+k4 5 ffiξλdfl?πffmo/u< = Ξ+l %OΠo/ο-[`Λ+Φ ο!` 5 3 (/&fimr5p0ß.fi!em]ffi3ff, Fig. 3 Circulatory flash speed versus ΔT arious Q 5 4 (/K)v»Mr5p0ß.ffi3ff, Fig. 4 Circulatory flash speed versus ΔT arious P e 5 5 (/> Π8ffmMr5p0ß.]ffi3ff, Fig. 5 Circulatory flash speed versus ΔT arious H 0 u4olo/ξ+l1w nu' 0/Λ4 6 fl?fl'.j(u LΠo/Ξa*ffg* & @l40 DTΛk4 6 ffiξπ!u. J(u LΠ
H OU Ex&(?$!Y`' Y`'b V>v{ $qv'#-!2,! $$#'#-s<z[0 9='#-&(v$!Y`$#+#- 4 A0w a ' Ex)5$!$#'q(!&(v$' {yy.0e x)5 $!$#'q(! $ I'\- u.!& # $I09=')5 $ #'3 $ %#-! z[:. U'5 #- 4 A 0 5 : NaCl 102 DT DT f n o Et Fig. Circulatory flash speed versus ΔT arious fm 有 f n w o 6 Et学 报 版 权 所 理 物 Fig. 6 Circulatory flash speed versus ΔT arious H0 ( % )5 4 E E % 4 & '*+ t # Zu T! T v& E P 'w 4 %Z+H ( 8$ 程 '热 #- A! $!),<40M&\?工x&(( 8$! Y.'#- AU 0#-: '> ;<, cn. x}6 > I0 [14] @?+V %y> et '& )C'!zzÆY!V { (5)'%$ NaCl i O&' {,@s? BPE '{ (5) *32 { p. t (6) 0 x NaCl O&8$!s?'KFy Y.' je / %,@ U 09=8$?'zzÆY.'% :/, Uh'\z[, ' #-U$'#- Atp U 0 ht R= 2σTsat (Tin Tsat )ρv r (5) R= 2σTbe (Tin Tbe )ρv r (6) f n o { } M Q=1200 L h 1, Pe =12.3 kpa, H0 =130 mm, fm =0.15 Fig. 8 Visualization of circulatory flash vaporization phenomenon: Q=1200 L h 1, Pe =12.3 kpa, H0 =130 mm, fm =0.15 8 )'Tbe = Tsat + BP E 0 * 3 5 *3r?'' 2!2 *l ' #-!#- A! $Y. U ' d{yy.6}$)=0 8 @?+#3 n!*, ~0*3r?! $s "'# ', }'!&~zf8 '#- As ' x 9 > #- A ~ G";/'H! $!Y.'#-YU'! $Y.<; 5 )5(! $ 0G% NaCl O& #-!# $'#-:}U ', + '49#-E/0 - A8 +2 60f<+ #-!#- )5 E c ' W B 4 E xy4 6 z A 4 E '*+ Z 5 4 & ~Q C) 0 5 4 A B; 5 4
1028 8 e E ffl o 38 w -ffjπψdl ΔT Πq4%ff QΠJ(u P e = ΞΩl H 0?= ΞCl f m fl2ρ+λ yqvqπ!ξ9;±flff )ULΠq4o /ο-ffq4%ff QΠJ(u P e %Ot%OΨ ff= Ξ+l&Cl %Oo/ο-Q Ψffψ dl%oπo/ο-nsοq Πa-DV%OT >ZοJ6Λ Z n Λ [1] Yan J J, hao F, Wang J,et al. Improvement of a Multi-tage Flash eawater Desalination ystem for Cogeneration Power Plants [J]. Desalination, 200, 21(1-3): 191 202 [2] Venkatesan G, Iniyan, Jalihal P. A Theoretical and Experimental tudy of a mall-cale Barometric ealed Flash Evaporative Desalination ystem Using Low Grade Thermal Energy [J]. Applied Thermal Engineering, 2014, 3(1): 629 640 [3] Zotarelli M F, Porciuncula B D A, Laurindo J B. A Convective Multi-Flash Drying Process for Producing Dehydrated Crispy Fruits [J]. Journal of Food Engineering, 2012, 108(4): 523 531 [4] Li Y Z, Yan M, Zhang L Q,et al. Method of Flash Evaporation and Condensation-Heat Pump for Deep Cooling of Coal-Fired Power Plant Flue Gas: Latent Heat And Water Recovery [J]. Applied Energy, 2016, 12: 10 11 [5] Osamu M, Murakami K, Kawata Y,et al. Fundamental Experiments with Flash Evaporation [J]. Heat Transfer- Japanese Research, 193, 2(4): 89 100 [6] Osamu M, Tetsu G, Toshiaki T,et al. Flash Evaporation Phenomena of Pool Water [J]. Hear Transfer-Japanese Research, 19, 6(2): 13 24 [] Gopalakrishna, Purushothaman V M, Lior N. An Experimental tudy of Flash Evaporation from Liquid Pools [J]. Desalination, 198, 65(1-3): 139 451 [8] aury D, Harmand, iroux M. Experimental tudy of Flash Evaporation of a Water Film [J]. International Journal of Heat and Mass Transfer, 2002, 45(16): 344 345 [9] Fath H. The Non-Equilibrium Factor and the Flashing Evaporation Rate Inside the Flash Chamber of a Multi- tage Flash Desalination Plant [J]. Desalination, 199, 114(3): 2 28 [10] Cipollina A, Micale G, Rizzuti L. Investigation of Flashing Phenomena in MF Chambers [J]. Desalination, 200, 216(1-3): 183 195 [11] Yan J J, Zhang D, Chong D T,et al. Experimental tudy on tatic/circulatory Flash Evaporation [J]. International Journal of Heat and Mass Transfer, 2010, 53(23): 5528 5535 [12] Zhang D, Chong D T, Yan J J,et al. tudy on team- Carrying Effect in tatic Flash Evaporation [J]. International Journal of Heat and Mass Transfer, 2012, 55(1/18): 448 449 [13] Zhang Y, Wang J, Liu J P,et al. Experimental tudy on Heat Transfer Characteristics of Circulatory Flash Evaporation [J]. International Journal of Heat and Mass Transfer, 2013, 6: 836 842 [14] Tong L, Tang Y. Boiling Heat Transfer and Two-Phase Flow [M]. Washington: Taylor & Francis, 199: 9