Sains Malaysiana 46(11)(2017): 2143-2148

http://dx.doi.org/10.17576/jsm-2017-4611-15

 

Influence of Air Supply Velocity on Temperature Field in the Self Heating Process of Coal

(Pengaruh Halaju Bekalan Udara pada Bidang Suhu dalam Proses Pemanasan Sendiri Arang Batu)

 

SHUANGLIN SONG1,2, SHUGANG WANG1*, YUNTAO LIANG2, XIAOCHEN LI1 & QI LIN1

 

1Faculty of Infrastructure Engineering, Dalian University of Technology, Dalian 116024, China

 

2State Key Laboratory of Coal Mine Safety Technology, CCTEG Shenyang Research Institute

Shenyang, 110016, China

 

Received: 15 January 2017/Accepted: 21 May 2017

 

ABSTRACT

The air supply velocity is an important factor affecting the spontaneous combustion of coal. The appropriate air velocity can not only provide the oxygen required for the oxidation reaction, but maintains the good heat storage environment. Therefore, it is necessary to study the influence of the actual air velocity in the pore space on the self-heating process of coal particles. This paper focuses on studying the real space piled up by spherical particles. CFD simulation software is used to establish the numerical model from pore scale. Good fitness of the simulation results with the existing results verifies the feasibility of the calculation method. Later, the calculation conditions are changed to calculate and analyze the velocity field and the temperature field for self-heating of some particles (the surface of the particles is at a certain temperature) and expound the effect of different air supply velocities on gathering and dissipating the heat.

Keywords: Coal self-heating; flow field; pore scale; self-heating point; temperature field

 

ABSTRAK

Halaju bekalan udara adalah faktor penting yang mempengaruhi pembakaran spontan arang batu. Halaju udara yang sesuai bukan sahaja dapat memberikan oksigen yang diperlukan untuk reaksi pengoksidaan, tetapi mengekalkan persekitaran penyimpanan haba yang baik. Oleh itu, adalah perlu untuk mengkaji pengaruh halaju udara sebenar di ruang liang pada proses pemanasan sendiri zarah arang batu. Makalah ini memberi tumpuan kepada mengkaji ruang sebenar yang ditimbun oleh zarah sfera. Perisian simulasi CFD digunakan untuk menubuhkan model berangka daripada skala liang. Kesesuaian yang baik daripada keputusan simulasi dengan keputusan sedia ada mengesahkan kelayakan kaedah pengiraan yang digunakan. Kemudian, keadaan pengiraan diubah untuk mengira dan menganalisis medan halaju dan medan suhu untuk pemanasan sendiri beberapa zarah (contohnya permukaan zarah berada pada suhu tertentu) dan menjelaskan kesan halangan bekalan udara yang berlainan pada pengumpulan dan menghilangkan haba.

 

Kata kunci: Bidang aliran; medan suhu; pemanasan sendiri arang batu; skala lubang; titik pemanasan sendiri

REFERENCES

Achenbach, E. 1995. Heat and flow characteristics of packed beds. Experimental Thermal and Fluid Science 10: 17-27.

Ahamed, A.J. & Loganathan, K., 2017. Water quality concern in the Amaravathi River Basin of Karur district: A view at heavy metal concentration and their interrelationships using geostatistical and multivariate analysis. Geology, Ecology, and Landscapes 1(1): 19-36.

Deng, J., Xu, J-C, & Wang, H-Q. 2002. Numerical simulation study on the spontaneous combustion process of the column coal sample. Journal of Liaoning Technical University (Natural Science Edition) 21: 129-132.

Dixon, A.G., Taskin, M.E., Nijemeisland, M. & Stitt, E.H. 2011. Systematic mesh development for 3D CFD simulation of fixed beds: Single sphere study. Computers and Chemical Engineering 35(7): 1171-1185.

Guardo, A., Coussirat, M., Larrayoz, M.A., Recasens, F. & Egusquiva, E. 2004. CFD flow and heat transfer in nonregular packings for fixed bed equipment design. Industrial & Engineering Chemistry Research 43(22): 7049-7056.

Jiang, P.X. & Lu, X.C. 2006. Numerical simulation of fluid flow and convection heat transfer in sintered porous plate channels. International Journal of Heat and Mass Transfer 49(9-10): 1685-1695.

Jolls, K.R. & Hanratty, T.J. 1966. Transition to turbulence for flow through a dumped bed of spheres. Chemical Engineering Science 21: 1185-90.

Krishnaswamy, S., Bhat, S. & Gunn, R.D. 1996. Low-temperature oxidation of coal. Fuel 75: 333-362.

Noraini, T., Ruzi, A.R., Ismail, B.S., Ummu Hani, B., Sahimi, S. & Azeyanty, J.A. 2016. Petiole vascular bundles and its taxonomic value in the tribe Dipterocarpeae (Dipterocarpaceae) Sains Malaysiana 45(2): 247-253.

Patankar, S.V. 1988.  Numerical Heat Transfer and Fluid Flow (New York: Taylor & Francis. pp. 13-16.

Sardar, M.S., Zafar, S. & Farahani, M.R. 2017. Computing sanskruti index of the polycyclic aromatic hydrocarbons. Geology, Ecology, and Landscapes 1(1): 37-40.

Tobiś, J. & Ziółkowski, D. 1988. Modelling of heat transfer at the wall of a packed-bed apparatus. Chemical Engineering Science 43: 3031-3036.

Wakao, N. & Funazkri, T. 1978. Effect of fluid dispersion coefficients on particle-to-fluid mass transfer coefficients in packed beds: Correlation of Sherwood numbers. Chemical Engineering Science 33: 1375-1384.

Wu, C.Y., Ferng, Y.M., Chieng, C.C. & Liu, C.C. 2010. Investigating the advantages and disadvantages of realistic approach and porous approach for closely packed pebbles in CFD simulation. Nuclear Engineering and Design 240: 1151-1159.

Xu, J. & Wang, H. 2002. The neural network prediction method for the limit parameters of coal self-ignition. Journal of China Coal Society 27: 366-370.

Yuan, L. & Smith, A.C. 2009. CFD modeling of spontaneous heating in a large-scale coal chamber. Journal of Loss Prevention in the Process Industries 22: 426-433.

 

*Corresponding author; email: sgwang@dlut.edu.cn

 

 

 

 

 

 

 

 

 

 

 

previous