The effect of air flow rate on smoke stratification in longitudinal tunnel ventilation

Ac a Mon anis ica Slo aca Volume 24 (2019), numbe 3, 173-187 173 The e ec o Ai Flow Ra e on Smoke S a i ica ion in Longi udinal Tunnel Ven ila ion Jiří Poko ný 1 , Lenka B uma o á 1 , Pe Kuče a 1 , Joze Ma inka 2 , Adam Thomi zek 1 and Pa el Zaple al 3 The cons uc ion o unnels is associa ed wi h mining. Fo sa e y and sui able wo king condi ions, i is necessa y o ensu e ha he e is sui able en ila ion du ing cons uc ion. Du ing ope a ion, unnels o m he in as uc u e o he a ea, which has a numbe o cha ac e is ics. Tunnel en ila ion is designed wi h ega ds o many di e en ac o s. Longi udinal en ila ion is especially used in one-way, ex a-u ban unnels bu in some cases also in u ban o wo-way unnels. The a icle desc ibes he pu pose and ypes o unnel en ila ion, ocusing on longi udinal en ila ion and en ila ion design s a egy. Longi udinal unnel en ila ion is he cause o signi ican u bulence ha a ec s he smoke s a i ica ion. The a icle compa es di e en unnel en ila ion op ions in e ms o selec ed s a egies and he di e en alues o applied ai low a es. A case s udy was conduc ed on he Klimko ice oad unnel in he Czech Republic using he i e model om he Fi e Dynamics Simula o . The s udy compa es he e ec o ai low a e on smoke s a i ica ion. The s udy was conduc ed wi h ai low a e alues o 0 o 5 m.s -1 . The esul s o he s udy show ha e en wi h lowe ai low a es, he smoke build-up is so signi ican ha he sa e y o indi iduals in he unnel canno be ensu ed. The dynamici y o i e is also an impo an ac o . Op ing o a lowe ai low a e s a egy because o highe expec ed conges ion o o he ac o s is a ques ionable p ac ice. G ea e ai low a es, howe e , c ea e be e condi ions o e acua ing indi iduals, al hough i is also necessa y o combine smoke s a i ica ion op ions wi h he selec ed en ila ion s a egy. Keywo ds: sa e y, unnel, i e, longi udinal en ila ion, smoke s a i ica ion In oduc ion Tunnel cons uc ion mus go hand in hand wi h sa e y. In he case o unnelling, he e is a necessi y o supply esh ai o he exposed ace o unnel ubes. The design equi emen s o en ila ing unnels a en' as speci ic as in, o example, gassy o non-gassy mines; howe e , he e is always he necessi y o supply esh ai o he wo kplace. The mos limi ing ac o s in en ila ing unnels a e he gases ca bon dioxide, monoxide, ni ogen oxides and hyd ogen sulphide. The ac ual en ila ion o he mined unnels depends on he p o ile and leng h o he exca a ion wo k. Fo example, sho unnelling ac i i y can be en ila ed by na u al en ila ion o by di usion, p o ided he limi concen a ions o he abo e gases a e no exceeded. In o he cases, i is necessa y o use a i icial en ila ion (sepa a e), which is p o ided by ans usually loca ed in on o he exca a ion po al and lu es, which b ing esh ai o he ace, o ice e sa used ai om he ace. In such cases, i is blow o suc ion en ila ion, he mos commonly used ype o en ila ion being he blow ype, especially wi h espec o he pu chase cos s o lu es, which may no ha e ein o cemen s, as in he case o he suc ion ype o en ila ion. In excep ional cases, o example, when using unnelling pla o ms, o when pe o ming small-p o ile unde g ound wo ks o ex usions whe e sepa a e en ila ion canno be es ablished, i can be en ila ed by comp essed ai . Gene ally, in unnelling, he e a e wo basic ac o s o conside when designing he ype o en ila ion, namely blas ing and he associa ed exhaus en ila ion a e blas ing ope a ions, and he use o diesel engines, which, apa om elec ic mo o s, a e he only kind ha can wo k and ope a e in unde g ound wo kspaces. Du ing ope a ion, oad unnels a e a complex s uc u e, equipped wi h a numbe o cons uc ion elemen s and acili ies ha enable i o ope a e, and in many cases con ibu e o ensu ing sa e y. I s ipula es he echnical and main enance equi emen s o unnels longe han 500 m (Eu opean Pa liamen Di ec i e 2004/54/ES). The sa e y equi emen s o building oad unnels a e gi en by na ional egula ions o each indi idual coun y. Examples a e Road Tunnel Ven ila ion, Design, Dimensioning and Equipmen , ASTRA 13001 om Swi ze land (ASTRA 13001, 2008), RABT 2006 Tunnel Equipmen and Ope a ion Guidelines om Ge many (RABT, 2006), Tunnel Ven ila ion - Basic P inciples Aus ian Resea ch Associa ion o Roads, Rail and T anspo om Aus ia (RVS 09.02.31 2008) Manual 021 No wegian Public Roads Adminis a ion S anda d 1 Jiří Poko ný, Lenka B uma o á, Pe Kuče a, Adam Thomi zek, VSB – Technical Uni e si y o Os a a, Facul y o Sa e y Enginee ing, Lumí o a 630/13, 700 30 Os a a – Výško ice, Czech Republic, ji i.poko ny@ sb.cz, [email p o ec ed], [email p o ec ed], [email p o ec ed] 2 Joze Ma inka, Slo ak Uni e si y o Technology in B a isla a, Facul y o Ma e ials Science and Technology in T na a, Jána Bo u 2781/25, 917 24 T na a, Slo ak Republic, [email p o ec ed] 3 Pa el Zaple al, VSB - Technical Uni e si y o Os a a, Facul y o Mining and Geology, 17. lis opadu 2172/15, 708 00 Os a a – Po uba, Czech Republic, [email p o ec ed] Jiří Poko ný, Lenka B uma o á, Pe Kuče a, Joze Ma inka, Adam Thomi zek and Pa el Zaple al: The e ec o Ai Flow Ra e on Smoke S a i ica ion in Longi udinal Tunnel Ven ila ion 174 Road Tunnels 03.04 om No way (Manual 021, 2004)DMRB Volume 2 Sec ion 2 Pa 9 (BD 78/99) Design (subs uc u es and special s uc u es). Special s uc u es. Design o oad unnels om G ea B i ain (DMRB, 1999) o NFPA 502 S anda d o Road Tunnels, B idges, and O he Limi ed Access Highways om he Uni ed S a es (NFPA 502, 2017). In he Czech Republic and Slo akia, hese equi emen s a e go e ned by go e nmen dec ees (Go e nmen dec ee no. 269/2009; Go e nmen dec ee no. 344/2006), echnical s anda ds ČSN 737507, 2013; STN 737507, 2008) and me hodical ins uc ions issued by minis ies (Ma aso á e al., 2010). Unde he Eu opean Pa liamen Di ec i e (EU) no. 305/2011 (which s ipula es he ha monized condi ions o in oducing cons uc ion p oduc s on he ma ke and epeals EU di ec i e 89/106/EHS), one o he condi ions oad unnels mus also comply wi h a e i e sa e y equi emen s (Regula ion (EU) No 305, 2011). The equi emen s include secu ing he load-bea ing p ope y o he s uc u e, limi ing he sp ead o i e inside and ou side he s uc u e, ensu ing he e acua ion and he sa e y o indi iduals and secu ing he sa e y o escue uni s. Sa e y s anda ds o unnels a e also gi en by he Wo ld Road Associa ion (Wo ld Road Associa ion PIARC, 2019). Ope a ing oad unnels is his o ically associa ed wi h a ious eme gency si ua ions. One o he mos dange ous si ua ions is i e, signi ican examples being he inciden in 1982 a he unnel in Salang, A ghanis an, whe e 176 people died, he i e in he Mon blanc unnel in F ance in 1999, which killed 39 people, and he Go ha d unnel in Swi ze land in 2001, whe e mo e han 100 people los hei li es. O he no able examples include he i e in he unnel on he highway be ween Flo ence and Bologna in 1993, which killed ou people, he i e in he P ände unnel nea B egenz in Aus ia in 1995, also killing ou people, and he i e in he unnel nea Pale mo in 1996, which killed i e people. The causes o hese i es we e ei he oad acciden s o ca i es. (Wo ld Road Associa ion PIARC, 2019) F om 2013 o 2018, he Czech Republic expe ienced i e oad unnel i es (Poko ny e al., 2018). Compa ed o he a e age o al numbe o i es in he Czech Republic, which is a ound 20,000, his igu e is negligible (Fi e Rescue Se ice, Czech Republic, 2019). Despi e his and no signi ican loss o li e o damage o p ope y and he en i onmen , his o ical e en s demons a e ha he consequences o i es in unnels can be de as a ing. (K očo á, 2015) In o de o mi iga e eme gency si ua ions, unnels mus be p epa ed s uc u ally, echnically and o ganisa ionally (Yang, 2016) by he enginee ing a chi ec , cons uc ion company, unnel ope a o and escue uni s (especially he i e escue se ices and police). One o he mos impo an equi emen s o secu ing he sa e y o unde g ound s uc u es is en ila ion. The equi emen s o unnel en ila ion a e simila o he equi emen s o gene al abo eg ound s uc u es (Poko ny and Gondek, 2016). I is possible o classi y oad unnel en ila ion in o s anda d ope a ing en ila ion, eme gency en ila ion ( i es), and en i onmen ally iendly en ila ion. In pa icula , s anda d ope a ional equi emen s can be unde s ood as hose ensu ing a sui able en i onmen o pe sons who may be p esen . Eme gency ope a ion means c ea ing condi ions ha ensu e he sa e e acua ion o pe sons and e ec i e in e en ion o escue uni s. En i onmen al en ila ion should ensu e a minimal impac o he unnel ope a ion on he en i onmen . (ASTRA 13001, 2008; Minis y o T anspo , Depa men o Roads, 2013; Tomaško á and Va go á, 2018). The aim o his s udy was o de e mine he e ec o longi udinal unnel en ila ion on he sa e y o indi iduals and he e ec i eness o i e se ices unde a gi en s a egy and he e o e also he di e en ai low a e alues. The a icle in es iga es whe he some s a i ica ion o smoke emained using low ai low a es. Ma e ial and Me hods Tunnel i e en ila ion Tunnel i e en ila ion is a suppo ing measu e o he e acua ion and escue o indi iduals and also suppo s escue uni s. Fo he design o i e en ila ion in unnels, he essen ials a e he ollowing (ASTRA 13001, 2008; NFPA 502, 2017):  a ic in ensi y and mode,  unnel leng h,  ope a ing mode (one-way o wo-way). Based on he abo e c i e ia, unnels can be di ided in o he ollowing ca ego ies o en ila ion pu poses (ASTRA 13001, 2008; Minis y o T anspo , Depa men o Roads, 2013):  unnels wi h unidi ec ional a ic and low p obabili y o conges ion (ca . T1, usually highway unnels),  unnels wi h unidi ec ional a ic and a high p obabili y o conges ion (ca . T2, usually highway unnels),  unnels wi h wo-way a ic (ca . T3). The ollowing concep s (s a egies) a e applied in designing i e en ila ion (Minis y o T anspo , Road Depa men , 2013): Ac a Mon anis ica Slo aca Volume 24 (2019), numbe 3, 173-187 175  na u al (longi udinal) en ila ion (sui able o sho unnels o T1 unnels),  longi udinal en ila ion, ixed ins alla ion (sui able o unnels o T1 unnels),  longi udinal en ila ion wi h ai low egula ion a de ined alues (sui able o T2 and T3 unnels),  ans e se en ila ion (sui able o T2 and T3 unnels). The gi en classi ica ion was pu in place in he Czech Republic. In p inciple, howe e , i is also used o many o eign coun ies whe e he classi ica ion may be modi ied. Fo longi udinal en ila ion in unnels, he equi ed ai low a e is essen ial. Ai low eloci y equi emen s a y somewha in he design guidelines and a e lis ed in Table 1 o cla i y. Table 1. Ai low eloci y se poin s o longi udinal en ila ion Coun y Cha ac e (ca ego y) unnel Requi ed low a e o longi udinal en ila ion (m.s -1 ) No e F ance (Annexe n° 2, 2000) one-way ex a-u ban unnels 3 one-way u ban unnels 3 ecommended o unnels up o 500 m long 1 - 2 (Phase 1) 3 (Phase 2) Phase 1 - he e acua ion o pe sons 2nd phase - suppo o escue uni s bidi ec ional 3 Czech Republic (Minis y o T anspo , Depa men o Roads, 2013) unidi ec ional unnels wi h a lowe incidence o conges ion (T1) c i ical ai eloci y up o 10 he c i ical speed is gene ally abou 3 m.s -1 unidi ec ional unnels wi h a highe incidence o conges ion (T2) 1.2 bidi ec ional unnels (T3) 1.2 Ge many (RABT, 2006) unidi ec ional unnels wi h a lowe incidence o conges ion 2.3 – 3.6 depends on unnel slope, unnel ube shape ( ec angula , hipped) and i e in ensi y unidi ec ional unnels wi h a highe incidence o conges ion 1.5 bidi ec ional unnels (T3) 1.5 Ne he lands (Huijben e al. (2006) No dependen on unnel cha ac e is ics 2.5 No way (Manual 021, 2004) unnels longe han 500 m and inclined ≥ 2 ° min. 2 i e en ila ion is speci ied by calcula ion o he unnels wi h inclina ion < 2 ° 2 i e in ensi y 5 MW 3.5 i e in ensi y 20 MW Aus ia (RVS 09.02.31 (2008) No dependen on unnel cha ac e is ics 2 o ai olume low in he unnel 120 m 3 .s -1 Swi ze land (ASTRA 13001, 2008) unidi ec ional unnels wi h a lowe incidence o conges ion (RV 1) 3 unidi ec ional unnels wi h a highe incidence o conges ion (RV 2) 1.5 - 3 depending on he unnel g adien and di ec ion o en ila ion bidi ec ional (GV) 1.5 Slo akia (TP 049, 2018) one-way a ic wi h a low p obabili y o conges ion (common highway unnels) (A) 1.5 - 2 (1 – 1.5 o excep ional bidi ec ional a ic) phase 1 - he e acua ion o pe sons in he case o smoke ex ac ion wi h longi udinal en ila ion 1.5 - 2 m.s -1 om bo h sides o he ex ac ion poin one-way a ic wi h a high p obabili y o conges ion (common highway unnels) (B) 1 – 1.5 wo-way a ic unnels (C) 1 – 1.5 all a ian s c i ical ai eloci y up 2nd phase - suppo o Jiří Poko ný, Lenka B uma o á, Pe Kuče a, Joze Ma inka, Adam Thomi zek and Pa el Zaple al: The e ec o Ai Flow Ra e on Smoke S a i ica ion in Longi udinal Tunnel Ven ila ion 176 o 10 escue uni s ini ia ion upon he demand o escue uni s Uni ed S a es o Ame ica (NFPA 502, 2017) No dependen on unnel cha ac e is ics c i ical ai eloci y up o 10 2.54 – 2.95 la ge-scale es s G ea B i ain (DMRB 1999) No dependen on unnel cha ac e is ics 1.3 i e ou pu 3 MW 3 i e ou pu 25 MW 7 i e ou pu 25 MW Table 1 shows ha in unidi ec ional unnels wi h a lowe incidence o conges ion, c i ical speeds a e gene ally equi ed. In unidi ec ional unnels wi h a highe incidence o conges ion, i is usually equi ed o educe he ai low a e below he c i ical speed ( he low a e educ ion is in he ange o 1.2 – 1.5 m.s -1 ). Con e sely, highe ai low a es will cause a mo e in ense in lux o smoke o he unnel (smoke s a i ica ion will be quickly in e up ed, and he smoke will be channelled in one di ec ion). The i e en ila ion design is s ongly linked o isk analysis. Risk analysis de e mines he choice o ype and s a egy o he en ila ion sys em. The gene al echniques o isk analysis a e applied o e alua e isk in oad unnels ( o example, ČSN EN 31010, 2011; ČSN ISO 31000, 2018). Fi e design An impo an ac o in designing unnel en ila ion is he i e scena io mos likely o de elop i e (Hauku Ingason e al., 2015; ISO 16733-1, 2015; KUČERA e al., 2009). The hea ou pu o he i e scena io in ela ion o he numbe o hea y uck ehicles pe uni o ime ( ypically a day) and he leng h o he unnel is 5, 30 and 50 MW. Di e en hea ou pu s can be de e mined in he isk analysis. (Minis y o T anspo , Roads Depa men , 2013). A hea ou pu alue o 30 MW is ypically conside ed in a i e en ila ion design. Fi e en ila ion design and s a egy in unnels Jus as in o he buildings and s uc u es, he mo emen o smoke c ea ed du ing a unnel i e is a ec ed by se e al ac o s ha ange om low o high impo ance. The main ac o s a ec ing he mo emen o smoke in unnel s uc u es a e as ollows (Poko ny and Gondek, 2016):  he unnel’s geome y,  chimney e ec ,  e ec o s a iona y ehicles,  wind,  buoyancy e ec c ea ed by he i e,  inc eased gas olume,  en ila ion equipmen . When i e en ila ion is designed o unnel s uc u es, hese a e impo an ac o s ha mus be conside ed. Sui able s a egies a e applied o en ila e oad unnels. The s a egy o longi udinal unnel en ila ion depends on he cha ac e is ics o he unnel in e ms o a ic di ec ion (one-way o wo-way) and he p obabili y o conges ion occu ing (low o high). Fi e en ila ion should ul il i s gi en unc ion in he selec ed s a egy. The aim o longi udinal en ila ion in unnels ope a ing wi h one-way a ic and a low p obabili y o conges ion (T1) is o channel (expel) he smoke in he di ec ion o ehicle a ic and p e en i sp eading owa ds s a iona y ehicles. The c i ical ai low a e is ypically be ween 2.5 o 3 m.s -1 . (ČSN 737507, 2013) The aim o longi udinal en ila ion in unnels wi h one-way a ic and a high p obabili y o conges ion (T2) o in wo-way a ic unnels (T3) is o channel he smoke and limi i s sp ead, o else dec ease i s low a e and c ea e he condi ions o smoke s a i ica ion o a ce ain pe iod o ime. Gene ally, he ai low a e used is 1.2 m.s -1 . (ČSN 737507, 2013) The c i ical gas low a e is de ined as he a e ha ensu es he smoke is channelled in he di ec ion o ehicle a ic and limi s i s sp ead owa ds s a iona y ehicles. The c i ical gas low a e and a e age smoke empe a u e can be de e mined by Kennedy’s model and calcula ed wi h he ollowing equa ions (NFPA 502, 2017):   =  ∙  ∙ ∙∙ ∙  ∙∙     (1)   =+  ∙  ∙∙   (2) whe e V c c i ical low a e [m.s -1 ] Ac a Mon anis ica Slo aca Volume 24 (2019), numbe 3, 173-187 177 K 1 F oude numbe , F -1/3 (0.606) [-] K g slope/g adien ac o [-] g accele a ion due o g a i y [m.s -2 ] H heigh o he unnel a he loca ion o he i e [m] Q con ec i e a io o eleased hea lux [kW] ρ a e age densi y o in oduced ai [kg.m -3 ] c p speci ic hea capaci y o smoke [kJ.(kg.K) -1 ] An a ea pe pendicula o he ai low [m 2 ] T a e age smoke empe a u e [K] T a e age in oduced ai empe a u e [K] Case s udy Aim o he s udy The equen ly selec ed s a egies, and he e o e also di e en ai low a es o longi udinal i e en ila ion in oad unnels, we e e alua ed in he case s udy. The Klimko ice unnel loca ed in he Mo a ia-Silesian egion nea he ci y o Os a a in he Czech Republic was selec ed o he case s udy. The Klimko ice unnel is pa o he D47 highway along he Bílo ec – Os a a, Rudná sec ion. The unnel is designed o one-way a ic wi h wo unnel ubes. The leng h o he unnel is app oxima ely 1000 m. The wid h o he oad is 9.5 m, and he wid h o he wo-way sidewalks is 1 and 1.2 m, he heigh o he unnel is 4.8 m. The unnel ubes ha e a longi udinal g adien o 0.6 %. The unnel ubes a e connec ed wi h i e jumpe s. Longi udinal en ila ion is ins alled in he unnel and consis s o eigh pai s o en ila o s. The en ila o s comply wi h he s anda d equi emen s o he Czech Republic o emain ope a ional in empe a u es o 400 °C o 90 minu es. The en ila o s always become ope a ional a e i e seconds. The unnel commenced ope a ion in 2008. Fi e model The ma hema ical i e model used o he case s udy is he Fi e Dynamics Simula o (FDS). The FDS model is a CFD model de eloped by NIST (Na ional Ins i u e o S anda ds and Technology, Ma yland, USA) and allows nume ous pa ame e s associa ed wi h i e de elopmen o be se , including he ‘enclosu e olume’ ac o . The model applies Na ie –S okes equa ions, which a e use ul o e alua ing he lux o smoke mo emen and also ake hea in o accoun . This i e model uses he Smoke iew so wa e o isualise he nume ical calcula ions. (Fi e Dynamics Simula o , 2019) A compu ing g id wi h cell dimensions o 0.5 x 0.5 x 0.5 m was used o calcula ion. The ini ial empe a u e was se o 15 °C, ela i e ai humidi y a 70 %. The en i onmen al condi ions we e de e mined p ima ily by he echnical p ope ies o he conc e e linings and he ai low a e in o he compu ing zone. The inpu assump ions o he s udy Fo he pu poses o he s udy, he unnel was e alua ed as an isola ed sys em wi hou conside ing ex e nal e ec s on he po al (such as wind). The poin o o igin o he i e was se a a dis ance o 256 m om he mo e ele a ed po al in he di ec ion o a ic (app oxima ely one- hi d o he unnel leng h). The main channel o longi udinal en ila ion was he e o e expec ed o be agains he g adien o he unnel. The hea ou pu o he i e was simula ed a wo design le els: 5 MW (pe sonal ehicle i e) and 30 MW (small uck o eigh ehicle i e). The ai low a e o he unnel was se o when en ila ion was no in ope a ion, hese being 0.5 m.s -1 , 1 m.s -1 , 1.5 m.s -1 , 2 m.s -1 , 2.5 m.s -1 , 3 m.s -1 , 3.5 m.s -1 and 5 m.s -1 . The geome y o he unnel and he loca ion o he i e o igin a e shown in Fig. 1. E alua ion me hod o he s udy The s udy e alua ed he e ec o ai low a e on e aining smoke s a i ica ion in he unnel. En i onmen isibili y was selec ed as a limi ing c i e ion. Visibili y was e alua ed a 20 e enly spaced measu emen poin s along he axis o he unnel (one poin e e y 50 m o he unnel’s leng h) a a heigh o 2.5 m abo e he oad’s su ace ( he con en ional limi alue o e alua ing he sa e y o indi iduals in espec o smoke om a i e) (ČSN P CEN/TR 12101-5, 2008). The momen o in e up ion o smoke s a i ica ion was de ined as he momen when isibili y dec eased o 15 m. This is he con en ional limi alue when panic and a signi ican inc ease in he di icul y o e acua ion is an icipa ed (Folwa czny and Poko ný, 2006; Hu ley, 2015). Gene ally, he ime o he sa e e acua ion o indi iduals ia an unp o ec ed eme gency exi is expec ed a 2.5 min (HOSSER, 2013). The a e o mo emen o indi iduals owa ds an unp o ec ed eme gency exi is ypically gi en as 30 m.min -1 (ČSN 73 0804, 2010). On he basis o hese assump ions, he dis ance o mo ing indi iduals o a sa e dis ance was app oxima ely 75 m. Jiří Poko ný, Lenka B uma o á, Pe Kuče a, Joze Ma inka, Adam Thomi zek and Pa el Zaple al: The e ec o Ai Flow Ra e on Smoke S a i ica ion in Longi udinal Tunnel Ven ila ion 178 Tunnel geome y Loca ion o i e in he unnel Fig. 1. The geome y o he unnel and he loca ion o he i e o igin Simula ion esul s The ollowing igu es show he esul s o he i e simula ion model. Fig. 2 shows he empe a u e p o ile a 180 s du ing i e he mal powe 30 MW and he mo emen o smoke nea he i e o igin poin wi hou en ila ion a 600 s and du ing he i e he mal powe a 5 MW. Tempe a u e p o ile a i e he mal powe o 30 MW Smoke mo emen wi hou en ila ion and i e powe o 5 MW Fig. 2. Rep esen a ion o empe a u e p o ile and smoke mo emen in he enclosed space The mo emen o smoke nea he i e o igin a 5 MW and 30 MW a 600 s and a ious smoke eloci ies a e shown in Fig. 3. The mal powe o i e 5 MW 30 MW Smoke mo emen a a low a e o 0.5 m.s - 1 and ou pu o 5 MW Smoke mo emen a a low a e o 0.5 m.s - 1 and ou pu o 30 MW Smoke mo emen a a low a e o 1.0 m.s - 1 and ou pu o 5 MW Smoke mo emen a a low a e o 1.0 m.s - 1 and ou pu o 30 MW Smoke mo emen a a low a e o 3.5 m.s - 1 and ou pu o 5 MW Smoke mo emen a a low a e o 3.5 m.s - 1 and ou pu o 30 MW Fig. 3. Demons a ion o smoke mo emen nea he i e o igin a a he mal ou pu o 5 MW and 30 MW Visibili y was e alua ed a e 100 seconds, 200 seconds, 300 seconds, 400 seconds, 500 seconds, and 600 seconds a e he i e's de elopmen . The dec ease in isibili y o a i e hea ou pu o 5 MW in ela ion o he simula ed ime and unnel posi ion is line). Fig Fig . Ac a Mon anis ica Slo aca V Visibili y was e alua ed a e 100 seconds, 200 seconds, 300 seconds, 400 seconds, 500 seconds, and 600 seconds a e he i e's de elopmen . The dec ease in isibili y o a i e hea ou pu o 5 MW in ela ion o he simula ed ime and unnel posi ion is shown in Figu es 4 o 12 Fig. 4. Visibili y wi hou en ila ion in ela ion o simula ed ime and posi ion in he unnel Fig . 5. Visibili y o he low a e o 0.5 m.s -1 in ela ion o simula ed ime and posi ion in he unnel . 6. Visibili y o he low a e o 1.0 m.s -1 in ela ion o simula ed ime and posi ion in he unnel sou ce o i e Ac a Mon anis ica Slo aca V olume 24 (201 Visibili y was e alua ed a e 100 seconds, 200 seconds, 300 seconds, 400 seconds, 500 seconds, and 600 seconds a e he i e's de elopmen . The dec ease in isibili y o a i e hea ou pu o 5 MW in ela ion o he shown in Figu es 4 o 12 ( he sou ce o i e is indica ed by Visibili y wi hou en ila ion in ela ion o simula ed ime and posi ion in he unnel in ela ion o simula ed ime and posi ion in he unnel in ela ion o simula ed ime and posi ion in he unnel (201 9), numbe 3, 173-187 179 Visibili y was e alua ed a e 100 seconds, 200 seconds, 300 seconds, 400 seconds, 500 seconds, and 600 seconds a e he i e's de elopmen . The dec ease in isibili y o a i e hea ou pu o 5 MW in ela ion o he i e is indica ed by he ed dashed in ela ion o simula ed ime and posi ion in he unnel in ela ion o simula ed ime and posi ion in he unnel Jiří Poko ný, Lenka B uma o á, Pe Ku Smoke S a i ica ion in Longi udinal Tunnel Ven ila ion 180 Fig . Fig . Fig . Fig. Lenka B uma o á, Pe Kuče a, Joze Ma inka, Adam Thomi zek Smoke S a i ica ion in Longi udinal Tunnel Ven ila ion . 7. Visibili y o he low a e o 1.5 m.s -1 in ela ion o simula ed . 8. Visibili y o he low a e o 2.0 m.s -1 in ela ion o simula ed ime and posi ion in he unnel . 9. Visibili y o he low a e o 2.5 m.s -1 in ela ion o simula ed ime and posi ion in he unnel 10. Visibili y o he low a e o 3.0 m.s -1 in ela ion o simula ed ime and posi ion in he unnel e a, Joze Ma inka, Adam Thomi zek and Pa el Zaple al: The e ec o Ai Flow Ra e on in ela ion o simula ed ime and posi ion in he unnel in ela ion o simula ed ime and posi ion in he unnel in ela ion o simula ed ime and posi ion in he unnel in ela ion o simula ed ime and posi ion in he unnel The e ec o Ai Flow Ra e on ime and posi ion in he unnel in ela ion o simula ed ime and posi ion in he unnel in ela ion o simula ed ime and posi ion in he unnel in ela ion o simula ed ime and posi ion in he unnel Fig. Fig The dec ease in isibili y p esen du ing a i e hea ou pu o 30 MW in ela ion o simula ed ime and posi ion inside he unnel is shown on Figu e 13 Fig Fig. Ac a Mon anis ica Slo aca V 11. Visibili y o he low a e o 3.5 m.s -1 in ela ion o simula ed ime and posi ion in he unnel Fig . 12. Visibili y o he low a e o 5.0 m.s -1 in ela ion o simula ed ime and posi ion in he unnel The dec ease in isibili y p esen du ing a i e hea ou pu o 30 MW in ela ion o simula ed ime and inside he unnel is shown on Figu e 13 o 21 ( he sou ce o i e is indica ed by he ed dashed line). Fig . 13. Visibili y wi hou en ila ion in ela ion o simula ed ime and posi ion in he unnel 14. Visibili y o he low a e o 0.5 m.s -1 in ela ion o sou ce o i e Ac a Mon anis ica Slo aca V olume 24 (201 in ela ion o simula ed ime and posi ion in he unnel in ela ion o simula ed ime and posi ion in he unnel The dec ease in isibili y p esen du ing a i e hea ou pu o 30 MW in ela ion o simula ed ime and ( he sou ce o i e is indica ed by he ed dashed line). Visibili y wi hou en ila ion in ela ion o simula ed ime and posi ion in he unnel in ela ion o simula ed ime and posi ion in he unnel (201 9), numbe 3, 173-187 181 in ela ion o simula ed ime and posi ion in he unnel in ela ion o simula ed ime and posi ion in he unnel The dec ease in isibili y p esen du ing a i e hea ou pu o 30 MW in ela ion o simula ed ime and ( he sou ce o i e is indica ed by he ed dashed line). simula ed ime and posi ion in he unnel