The Application of a Jet Fan for the Control of Air and Methane Streams Mixing at the Excavations Cross – The Results of Numerical Simulation

Wrona, Paweł; Różański, Zenon; Pach, Grzegorz; Domagała, Lech

doi:10.2478/mspe-03-03-2016

Cited by 3 publications

(1 citation statement)

References 5 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This software has already been applied for the simulation of gas flow in underground excavations or in the tunnels (e.g. Wrona, 2013;Wrona et al, 2013;Suban 2015;Wrona et al, 2016a). The model has been validated by the National Institute of Standards and Technology, USA (McGrattan et al, 2010).…”

Section: The Modelmentioning

confidence: 99%

The Influence of Climate Change on CO2 and CH4 Concentration Near Closed Shaft – Numerical Simulations

Wrona¹

2017

Archives of Mining Sciences

Self Cite

View full text Add to dashboard Cite

Given the scientific consensus pointing to climate change, the more extreme weather events associated with this will lead to deeper pressure drops. As has already been stated, pressure drops are the main cause of gas flow from underground sites to the surface. This article presents the results of numerical simulations of the change in distribution of CO 2 and CH 4 near a closed mining shaft under the predicted baric tendency. Simulations have been undertaken by means of the FDS software package with the Pyrosim graphical interface -a CFD tool for fire and ventilation analysis. Assumptions have been based on previous results of in-situ measurements. The results (determined for a height of 1m above the ground) were compared to the following levels (later in the text comparison levels): for CO 2 0.1%vol. according to Pettenkoffer's scale and 2.5%vol. for CH4 as the half of Lower Explosive Limit (LEL). The results show that the deeper baric drops anticipated could lead to a wider spread of both greenhouse gases in the vicinity of the shaft, especially along the prevailing wind direction. According to the results obtained, CO 2 and CH 4 with concentrations above their comparison levels are expected at a distance greater than 50m from the shaft when wind is present for CO 2 and at a distance of 4.5m for CH 4 . Subsequent analysis of the results enabled the determination of functions for describing the concentration of gases along the wind direction line under the projected pressure drop. The results relate to a particular case, although the model could easily be modified to any other example of gas emissions from underground sites.Keywords: greenhouse gas emissions, climate change, mine closure, abandoned shaft, underground gas storage, public safety, CFD Wraz ze zmianami klimatu należy spodziewać się większej niż obecnie liczby dni w roku, w któ-rych będą występować ekstremalne zjawiska pogodowe, związane z przechodzeniem coraz głębszych frontów atmosferycznych (np. Falarz, 1997; Koźmiński i Michalska, 2010). Przyczyni się to do wzrostu tendencji barycznej zniżek ciśnienia. Zniżki baryczne są główną przyczyną emisji gazów kopalnianych na powierzchnię (Wrona et al., 2016b). Gazy te zawierają głównie CO 2 i CH 4 , które są uznawane za gazy cieplarniane oraz mogą stworzyć lokalne zagrożenie dla bezpieczeństwa powszechnego (np. Czaja, 2012 640W artykule przedstawiono wyniki symulacji numerycznych dotyczących zmiany stężenia obu gazów emitowanych z nieczynnego szybu górniczego na skutek zwiększającej się zniżkowej tendencji barycznej. Na podstawie analizy literaturowej zagadnienia (np. Falarz, 1997), stwierdzono, że w przyszłości możliwe są ekstremalne zniżki baryczne sięgające lub nawet przekraczające 5 hPa/1h. Na obszarze południowej Polski można spodziewać się raz na dwa lata zniżki sięgającej 4 hPa/1h oraz raz na 10 lat przekraczającej 5 hPa/1h. Takie zdarzenie, spowodowane przez zmiany klimatu, może doprowadzić do intensywniejszego wypływu gazów z obszarów podziemnych, a przez to zasięg ich oddziaływania może być za...

show abstract

Section: The Modelmentioning

confidence: 99%

The Influence of Climate Change on CO2 and CH4 Concentration Near Closed Shaft – Numerical Simulations

Wrona¹

2017

Archives of Mining Sciences

Self Cite

View full text Add to dashboard Cite

show abstract

Evaluation of synthetic gas harmful effects created at the underground coal gasification process realized in laboratory conditions

et al. 2019

View full text Add to dashboard Cite

The Prediction of Possibilities of CO Poisoning and Explosion during Syngas Leakage in the UCG Process

et al. 2021

View full text Add to dashboard Cite

Underground coal gasification (UCG) is an industrial process that converts coal into product gas (syngas). This technology makes it possible to obtain energy without mining coal and post-processing. The UCG process is considered a safe technology with various advantages over conventional mining techniques. However, a small amount of potentially dangerous syngas may escape from the UCG cavity, and it is necessary to pay attention to the safety of the process in this respect. This article analyses the impact of a syngas leak from UCG on a possible CO poisoning and explosion hazard in the vulnerable zones. Measured data from experiments and proposed mathematical models were used for the analysis of the UCG process and simulation studies. It is mainly a mathematical model mixing of gases, which evaluated the danger of explosion and CO poisoning in sensitive zones. This model predicts the composition of the syngas mixture with air because this mixture can be dangerous at a certain concentration. Simulation studies focused mainly on CO poisoning in vulnerable areas based on the measured data from laboratory experiments. Simulation studies have shown that the critical value of CO poisoning can achieve with a certain composition of syngas and its escape into vulnerable areas. The results of the studies here indicate a possible hazard. However, by monitoring and control of UCG process, this risk can be minimized. Based on the obtained results, the control of the supply of fresh air to the endangered area during the monitoring of the syngas composition was proposed to prevent the occurrence of possible poisoning.

show abstract

The Application of a Jet Fan for the Control of Air and Methane Streams Mixing at the Excavations Cross – The Results of Numerical Simulation

Cited by 3 publications

References 5 publications

The Influence of Climate Change on CO2 and CH4 Concentration Near Closed Shaft – Numerical Simulations

The Influence of Climate Change on CO2 and CH4 Concentration Near Closed Shaft – Numerical Simulations

Evaluation of synthetic gas harmful effects created at the underground coal gasification process realized in laboratory conditions

The Prediction of Possibilities of CO Poisoning and Explosion during Syngas Leakage in the UCG Process

Contact Info

Product

Resources

About