Effect of natural pressure drop in mine main ventilation

DOI 10.2478/amsc-2014-0036 A ch. Min. Sci., Vol. 59 (2014), No 2, p. 501–508 Elec onic e sion (in colo ) o his pape is a ailable: h p://mining.a chi es.pl PAVEL ZAPLETAL*, VLASTIMIL HUDEČEK*, VITALY TROFIMOV**, EFFECT OF NATURAL PRESSURE DROP IN MINE MAIN VENTILATION SKUTKI NATURALNEGO SPADKU CIŚNIENIA W GŁÓWNEJ SIECI WENTYLACYJNEJ KOPALNI Na u al en ila ion in a mine is en ila ion wi hou he use o means o a i icial en ila ion. The low o mine ai is induced by he di e ence be ween he mass column in an in ake and ha in a e u n. The di e ence in mine ai densi y is a esul o di e ence be ween he empe a u e o in ake ai and ha o e u n ai . To a ce ain ex en , he in luence o di e ences in mine ai humidi y and chemical composi ion can ac as well. Gassy mines in he Czech Republic and Uk aine a e en ila ed me ely a i icially, i.e. by means o exhaus en ila ion. Howe e , e en in he case o his ype o en ila ion, when he o al mine ai low is p oduced by ans, a na u al cu en o ai exis s and ac s in he en ila ion ne wo k o he mine. Keywo ds: Mine en ila ion, na u al p essu e d op, empe a u e, main an Na u alna wen ylacja w kopalni o wen ylacja bez wyko zys ania ś odków sz ucznej wen ylacji. P zepływ kolumny powie za wymuszony jes pop zez óżnicę ciśnień pomiędzy kolumną powie za na wlocie a p ądem zuży ego powie za. Różnica w gęs ości powie za kopalnianego wynika z óżnicy empe a u pomiędzy powie zem wlo owym i zuży ym. W pewnym s opniu uwidacznia się akże wpływ wilgo ności powie za kopalnianego i jego składu chemicznego. Kopalnie gazowe w Republice Czeskiej i na Uk ainie są p zewie zane p zy użyciu sz ucznej wen yla- cji, z wyko zys aniem ins alacji wyciągowej. Jednakże nawe w p zypadku zas osowania ego ypu sys emu wen ylacyjnego w k ó ym p zepływ powie za kopalnianego w całości gene owany jes p zez wen yla o y, nadal is nieją na u alne p ądy powie za, k ó ych obecność i działanie ujawnia się w sieci wen ylacyjnej. Słowa kluczowe: wen ylacja kopalni, na u alny spadek ciśnienia, empe a u a, wen yla o główny * VSB – TECHNICAL UNIVERSITY OF OSTRAVA ** DONECK NATINONAL TECHNICAL UNIVERSITY B ough o you by | Technicka Uni e zi a Os a a Au hen ica ed Download Da e | 1/28/15 1:52 PM 502 In oduc ion When passing h ough he mine and imagina ily back h ough he su ace a mosphe e, he mine ai unde goes a e e sible change. F om he a mosphe e he ai o empe a u e T0 and p essu e p0 lows o he mine whe e he men ioned s a e quan i ies g adually change o T1 up o Tn and p1 up o pn. The ai exi ing he mine mixes wi h he a mosphe ic ai and, wi h ega d o he disp opo iona ely la ge olume o he a mosphe ic ank ha can be aken wi h e e ence o he small amoun o mine ai as in ini e, he ini ial empe a u e T0 and p essu e p0 o ai emain cons an . The he modynamic cycle is hus closed and hen epea ed again (Suchan, 1984). The na u al cu en as well as he p essu e d op p oduced by he main an is a sou ce o ene gy o he low o ai in he mine. The na u al cu en p essu e d op is posi i e i he cu en ope a es syne gis ically wi h he an and he d op is nega i e i i ope a es non-syne gis ically wi h he an. 1. Ac i a ion a Combina ion o Fans I and II in Se ies The ac i a ed cha ac e is ic (AB)AS a elimina ing a an connec ed in se ies (e.g. I) is ob ained by deduc ing ele an o dina es o he cha ac e is ic o an I (p – Q )1 om indi idual o dina es o he cha ac e is ic o segmen AB ΔpAB = RAB · Q 2. Fig. 1. Ac i a ion a combina ion o ans I and II in se ies B ough o you by | Technicka Uni e zi a Os a a Au hen ica ed Download Da e | 1/28/15 1:52 PM 503 The in e sec ion o he ac i a ed cha ac e is ic (AB)AS wi h he cha ac e is ic o an II (p – Q )2 will be designa ed PS; his is he ope a ing poin ha de e mines he condi ions o combina ion o ans I and II. The o dina e o poin PS ep esen s he olume low a e Q s in he segmen AB. A pa allel o he axis o o dina es, unning h ough he poin PS, will in e sec he cha ac e is ic (p – Q )1 a he poin P1S and he cha ac e is ic ΔpAB = RAB · Q 2 a he poin P2S. The o dina e o poin PS gi es he p essu e g adien Δp2S p oduced by an II, he o dina e o poin P1S gi es he p essu e g adien Δp1S p oduced by he an I and he o dina e o poin P2S gi es he p essu e g adien ΔpS, i he ai wi h he olume low a e Q s lows along he segmen AB. 2. Ac i a ion a Pa allel Combina ion o Fans I and II The ac i a ed cha ac e is ic (AB)AP a elimina ing a an connec ed in pa allel (e.g. II) is ob- ained by deduc ing ele an segmen s o he cha ac e is ic o an II (Δp – Q 2)2 om indi idual segmen s o he cha ac e is ic o segmen AB ΔpAB = RAB · Q 2. Fig. 2. Ac i a ion a pa allel combina ion o ans I and II B ough o you by | Technicka Uni e zi a Os a a Au hen ica ed Download Da e | 1/28/15 1:52 PM 504 The in e sec ion o he ac i a ed cha ac e is ic (AB)AP wi h he cha ac e is ic o an I (p – Q ) will be designa ed PP. A pa allel o he axis o he segmen s passing h ough he poin PP in e sec s he cha ac e is ic o an II (Δp – Q )2 a he poin P1P and he cha ac e is ic o he segmen ΔpAB = RAB · Q 2 a he poin P2P. The o dina e o poin PP gi es he olume low a e Q 1P o an I, he o dina e o poin P1P hen he olume low a e Q 2P o an II and he o dina e o poin P2P gi es he o e all olume low a e Q 2 in he segmen AB. The o dina e o poin PP gi es he p essu e g adien ΔpP in he segmen AB and p essu e g adien s caused by he ans. (P okop e al., 1985, 2011) 3. Replacemen o a Fan by a Na u al Sou ce o P essu e D op When one o he ans is eplaced by a na u al sou ce o p essu e d op, a combina ion o he an and he sou ce o na u al p essu e d op can be deal wi h. The cha ac e is ic o he sou ce o p essu e d op is ep esen ed in he diag am Δp – Q as a pa allel o he axis Q a a dis ance o he gi en alue o Δp. Then h ee cases o in e ac ion be ween he main an and he sou ce o na u al p essu e d op (na u al p essu e d op = NVP) may occu . (1) NVP ac s syne gis ically wi h he main an, (2) NVP ac s non-syne gis ically – agains he ac ion o he main an, (3) The alue o NVP is so small ha i will no a ec he wo k o he main an. In Figu e 4 we can see he ac i a ed cha ac e is ic (auxilia y ac i a ed cu e NVP = –320 Pa) and he ep esen a ion o he ope a ing poin on he ope a ing cha ac e is ic o he an. We can see ha he ope a ing poin will mo e by he ac i a ion o he mine cha ac e is ic by 320 Pa downwa ds. This means ha he an only needs “ o p oduce a p essu e d op by 320 Pa smalle ” o p oduce he equi ed olume ai low a e (Kopáček, 2003). In addi ion o he ae odynamic esis ance o mine wo kings hemsel es, he main mine an has o o e come he ae odynamic esis ance o he ai duc , he in e nal esis ance o he an i sel and he ae odynamic esis ance o he di use . The o al nega i e p essu e ha has o be p oduced by he an is hen gi en by he ollowing ela ion Δpc Δpc = Δpdd + Δpk + Δp + Δpd ± Δpn [Pa] (1) whe e: Δpc — o al nega i e p essu e, [Pa], Δpdd — p essu e g adien equi ed o o e coming he o al ae odynamic esis ance o mine wo kings, [Pa], Δpk — p essu e g adien equi ed o o e coming he esis ance o he ai duc , [Pa], ±Δpn (NVP) — p essu e g adien due o he na u al p essu e d op, [Pa], Δp — p essu e g adien necessa y o o e coming he in e nal esis ance o he an oge he wi h he esis ance o he noise dampe and di use chambe . To he consump ion o nega i e p essu e we ha e o add he alue o dynamic ( eloci y) com- ponen o p essu e du ing he exi o ai masses o he a mosphe e, and his is gi en by he ol- lowing ela ion: B ough o you by | Technicka Uni e zi a Os a a Au hen ica ed Download Da e | 1/28/15 1:52 PM 505 2 2 d p   [Pa] (2) whe e: — eloci y o mine ai exi ing o he a mosphe e, [m·s–1], ρ — densi y o e u n ai mo ed by he main an, [kg·m–3]. The magni udes o he alues o indi idual esis ances ha e he decisi e in luence on he wo k o he main an. Tha is why i is necessa y o o m, as ea ly as du ing he s age o plan- ning, p econdi ions o as small as possible ae odynamic esis ance o he ai duc . This can be achie ed by sho ening he leng h o he duc , by g adual non-sha p changing he di ec ion o ai low in ai channels, by slow changing he shape o ai channels when di iding he ai low in o pa allel b anches, e c. (Skoczylas, 2012) 4. Model Si ua ion o Combina ion o Na u al Ai Cu en and Mine Main Ven ila ion On he basis o measu ed alues om he Ka iná Mine, ČSA plan , we analysed model si ua ions o he combina ion o na u al ai cu en and mine main en ila ion (Zaple al, 2009). Fig. 3. Ac i a ed cu e o esis ance o he mine including NVP e ec s (Kopáček, 2003) B ough o you by | Technicka Uni e zi a Os a a Au hen ica ed Download Da e | 1/28/15 1:52 PM 506 Fo he analyse we used polish so wa e Ven g aph (Dziu zynski e al., 2009, 2011). This p o- g am is used o he en ila ion ne wo k calcula ions in he no mal condi ions and he anomalous condi ions, like a mine i e, o me hane exhala ions. (Hudeček, 2008) The basic pa ame e s o his analysis we e measu ed alues o d y empe a u es and comp essible calcula ion o he en ila ion ne wo k. Su ace empe a u e: 18.8°C, Rela i e humidi y: 51%, Ba ome ic p essu e: 102000 Pa, Fan p essu e d op – upcas sha : ČSA 3 3169 Pa, Doub a a III 2727 Pa, Eleono a 3020 Pa. TABLE 1 Table o pa o calcula ion a empe a u e o 18.8°C and ini ial p essu e d op o ans B anch no. Nodal poin 1 Nodal poin 2 ρQ Δp [kg·m–7] [m3·s–1] [Pa] 0 1 1A 1.21 212.3 0 1 1A 2 1.24 207.3 565.4 2 2 3 1.28 196.1 150.4 3 3 4 1.30 162.8 57.5 4 3 7 1.29 6.2 10.2 The ollowing able shows a change in mine ai densi y ρ, olume low a e Q and p essu e d op Δp a a change in empe a u e in wo in ake nodes (a he nodal poin 1A om 18.8°C o -5°C and a he nodal poin 2 om 21°C o -2°C) TABLE 2 Table o pa o calcula ion a pa ial change in empe a u e and ini ial p essu e d op o ans B anch no. Nodal poin 1 Nodal poin 2 ρQ Δp [kg·m–7] [m3·s–1] [Pa] 0 1 1A 1.33 257 0 1 1A 2 1.36 250.3 824.6 2 2 3 1.34 244.2 233.2 3 3 4 1.30 202.7 88.8 4 3 7 1.29 4.7 147.3 Su ace empe a u e: –5°C, Rela i e humidi y: 51%, Ba ome ic p essu e: 102000 Pa, Fan p essu e d op – upcas sha : ČSA 3 2535.2 Pa, Doub a a III 2181.6 Pa, Eleono a 2416 Pa. B ough o you by | Technicka Uni e zi a Os a a Au hen ica ed Download Da e | 1/28/15 1:52 PM 507 TABLE 3 Table o pa o calcula ion a pa ial change in empe a u e and a educ ion in p essu e d op o ans by 20% B anch no. Nodal poin 1 Nodal poin 2 ρQ Δp [kg·m–7] [m3·s–1] [Pa] 0 1 1A 1.33 242.8 0 1 1A 2 1.36 236.6 736.4 2 2 3 1.34 230.5 207.7 3 3 4 1.30 190.4 78.7 4 3 7 1.29 23.4 146.2 F om he ollowing ables Tabs. 1, 2 and 3 i is e iden ha he p og am Ven g aph can also be used o he con ol o p essu e d ops o main ans a a change in ai empe a u e. I could be used p o i ably in he case o combina ion o mine main en ila ion and na u al ai cu en . The compa ison o Tables 1 and 2 shows ha a a change in su ace empe a u e, p essu e d ops in he ne wo k b anches and olume low a es o ai will inc ease due o he na u al ai cu en . I we howe e dec ease p essu e d ops o main ans (e.g. by 20%), hen a keeping he dec eased empe a u e, a educ ion in p essu e d ops a nodal poin s and in olume low a es will occu . (Gacek e al., 2007) 5. Ac ual The mal Buoyancy and A e age Tempe a u es To e i y he p e ious conside a ions, we compa ed he ue alues om he en ila ion balances o s ill ac i e mines. In he ollowing able, he amoun o he na u al p essu e d op Δp e a a ious decisi e quan i ies, such as s a ic p essu e Δps , su ace empe a u e and olume low a e Q is clea . TABLE 4 The mal buoyancy Mine – upcas sha P essu e d op measu emen NVP [Pa] Su ace empe a u e Δps [Pa] Q [m3·s–1] ČSM – Jih May –136 14,5°C 2750 309 ČSM – Se e May –242 15°C 2650 315 DARKOV – Mí 4 May –190 15°C 2786 433 DARKOV – Su-S o III May –132 12°C 1916 230 KARVINÁ – ČSA 3 May –470 17,5°C 3875 258 KARVINÁ – Do-III May –360 17,5°C 2698 145 KARVINÁ – Lazy June –75 22°C 2089 300 PASKOV – S iadno Oc obe –230 3,5°C 2580 136 PASKOV – S aříčOc obe –305 3,5°C 3178 219 PASKOV – Chlebo ice Oc obe –205 4,5°C 2990 218 I can be deduced om Table 4 ha he mal buoyancy in mines being compa ed ac s syn- e gis ically wi h he main ans. B ough o you by | Technicka Uni e zi a Os a a Au hen ica ed Download Da e | 1/28/15 1:52 PM 508 6. Conclusion An impo an condi ion o he calcula ion o en ila ion ne wo k wi h he use o a i icial en ila ion and na u al ai cu en and con ol o p essu e d ops caused by main ans is he con- side a ion o a possible change in empe a u e a all nodal poin s, especially hen a he nodal poin s o main downcas and upcas sha s. Thus he o e all in luence o na u al en ila ion on he whole en ila ion ne wo k will mani es i sel . Mine en ila ion is a e y impo an pa ame e o ac i e mines and cos s o mine en ila ion hemsel es a e usually a e y signi ican i em o he o e all cos s o he mine. I he na u al ai cu en was easonably used in mine en ila ion, a educ ion in elec ical ene gy consump ion could be achie ed, because ans would no wo k a hei usual pe o mance and hus also he cos s o mine en ila ion i sel could be dec eased. Re e ences Dziu zynski W., K ach A., Palka T., 2009. 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Coal seam me hane p essu e as a pa ame e de e mining he le el o he ou bu s isk – labo a o y and in si u esea ch. A ch. Min. Sci., Vol. 57, No 4, p. 861-869. Suchan L., 1984. Deep Mine Ven ila ion, Libo Suchan, P ague 1984. Zaple al P 2009. P oposal o P inciples o Con ol o Ven ila ion Ne wo k in a Fi e-A ec ed A ea. Ph.D. hesis, VŠB – TU Os a a. Rec ei ed: 19 Augus 2013 B ough o you by | Technicka Uni e zi a Os a a Au hen ica ed Download Da e | 1/28/15 1:52 PM