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
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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
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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
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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:
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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)
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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.
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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.
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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. Me hod o Regula ing Elemen s o he Me hane D ainage Ne wo k Using
Compu e Simula ion. A ch. Min. Sci., Vol. 54, No 2, p. 159-187.
Dziu zynski W., K uczkowski J., 2011. Va iabili y o he olume ic ai low a e in a mine an channel o a ious
dampe posi ions. A ch. Min. Sci., Vol. 56, No 4, p. 641-650.
Gacek Z., Olajossy A., 2007. Ma e ial balance in a pseudo-s eady s a e o na u al gas low. A ch. Min. Sci., Vol. 52,
No 2, p. 171-193.
Hudecek V., 2008. Analysis o Sa e y P ecau ions o Coal and Gas Ou bu s – Haza dous S a a. Jou nal o Mining
Science, Vol. 44, No 5, p. 42-50.
Kopáček F., 2003. The coope a ion o he p essu e sou ces wi h he subsu ace en ila ion. Associa e p o esso hesis,
VŠB – TU Os a a.
P okop P. e al., 1985. Ven ila ion o deep mines. VŠB – TU Os a a, ex book, 1985.
P okop P., Zaple al P., Peg imek I., 2011. P ognosis o esidual coal gas capaci y made by he “exp ess” me hod. In e -
na ional Jou nal o Mine als, Me allu gy and Ma e ials, 18 (2011), No.2, p.127.
Skoczylas N., 2012. 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
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