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Abstract

This article proposes a method for grinding coal based on the use of the energy of a pulsed shock wave resulting from a spark electric discharge in a liquid. The main purpose of the scientific work is the development of an electric pulse device for producing coal powder, the main component of coal-water fuel. The diameter of the initial coal fraction averaged 3 mm, and the size of the resulting product was 250 μm. To achieve this goal, the dependence of the length of a metal rod electrode (positive electrode) on the length and diameter of its insulation is investigated. Various variants of the shape of the base (bottom) of the device acting as a negative electrode are considered, and an effective variant based on the results of coal grinding is proposed. An experimental electric pulse installation is described, the degree of coal grinding is determined depending on the geometric parameters. The optimal characteristics of the obtained coal powder have been established.
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Bibliography

[1] A. Hanif, Z. Lu, and Z. Li. Utilization of fly ash cenosphere as lightweight filler in cement-based composites – A review. Construction and Building Materials, 144(30):373–384, 2017. doi: 10.1016/j.conbuildmat.2017.03.188.
[2] A. Kijo-Kleczkowska. Research on coal-water fuel combustion in a circulating fluidized bed. Archives of Mining Sciences, 57(1):79–92, 2012. doi: 10.2478/v10267-012-0006-5.
[3] R.S. Blissett and N.A. Rowson. A review of the multi-component utilisation of coal fly ash. Fuel, 97:1–23, 2012. doi: 10.1016/j.fuel.2012.03.024.
[4] M.A. Dmitrienko, A.G. Kosintsev, G.S. Nyashina, and S.Yu. Lyrshchikov. Anthropogenic emissions from combustion of coal-water slurries containing petrochemicals based on coal and oil processing wastes. Chemical and Petroleum Engineering, 54(8):57–62, 2018. doi: 10.1007/s10556-018-0439-6.
[5] A. Staroń, Z. Kowalski, P. Staroń, and M. Banach. Analysis of the useable properties of coal-water fuel modified with chemical compounds. Fuel Processing Technology, 152:183–191, 2016. doi: 10.1016/j.fuproc.2016.07.007.
[6] A. Atal and Y.A. Levendis. Observations on the combustion behavior of coal water fuels and coal water fuels impregnated with calcium magnesium acetate. Combustion and Flame, 93(1-2):61–89. 1993. doi: 10.1016/0010-2180(93)90084-G.
[7] S. Yavuzkurt and M.Y Ha. A model of the enhancement of combustion of coal-water slurry fuels using high-intensity acoustic fields. Journal of Energy Resources Technology, 113(4):268–276, 1991. doi: 10.1115/1.2905911.
[8] D.O. Glushkov, S.V. Syrodoy, A.V. Zhakharevich, and P.A. Strizhak. Ignition of promising coal-water slurry containing petrochemicals: Analysis of key aspects. Fuel Processing Technology, 148:224–235, 2016. doi: 10.1016/j.fuproc.2016.03.008.
[9] D.O. Glushkov, S.Y. Lyrshchikov, S.A. Shevyrev, and P.A. Strizhak. Burning properties of slurry based on coal and oil processing waste. Energy & Fuels, 30(4):3441–3450, 2016. doi: 10.1021/acs.energyfuels.5b02881.
[10] G.S. Khodakov. Coal-water suspensions in power engineering. Thermal Engineering, 54(1):36–47, 2007. doi: 10.1134/S0040601507010077.
[11] G.A. Núñez, M.I. Briceño, D.D. Joseph, and T. Asa. Colloidal coal in water suspensions. Energy & Environmental Science, 3(5):629–640. 2010. doi: 10.1039/B923601P.
[12] F.Boylu, H. Dinçer, and G. Ateşok. Effect of coal particle size distribution, volume fraction and rank on the rheology of coal-water slurries. Fuel Processing Technology, 85(4):241–250, 2004. doi: 10.1016/S0378-3820(03)00198-X.
[13] J. Robak, K. Ignasiak, and M. Rejdak. Coal micronization studies in vibrating mill in terms of coal water slurry (CWS) fuel preparation. Journal of Ecological Engineering, 18(2):111–118. 2017. doi: 10.12911/22998993/68214.
[14] A.R. Rizun, T.D. Denisyuk, Y.V. Golen, V.Y. Kononov, and A.N. Rachkov. Electric discharge disintegration and coal desulphurization in the manufacture of water-coal fuel. Surface Engineering and Applied Electrochemistry, 47(1):100–102. 2011. doi: 10.3103/S1068375511010170.
[15] I. Kuritnik, B.R. Nussupbekov A.K. Khassenov, D.Zh. Karabekova. Disintegration of copper ores by electric pulses. Archives of Metallurgy and Materials, 60(4):2449–2551. 2015. doi: 10.1515/amm-2015-0412.
[16] L.A. Yutkin. Electrohydraulic effect and its application in industry. Mechanical Engineering, 1986. (in Russian).
[17] B.R. Nussupbekov, A.K. Khassenov, D.Zh. Karabekova, U.B. Nussupbekov, M. Stoev, and M.M. Bolatbekova. Coal pulverization by electric pulse method for water-coal fuel. Bulletin of the University of Karaganda-Physics, 4(96):80–84, 2019. doi: 10.31489/2019Ph4/80-84.
[18] V.I. Kurets, M.A. Soloviev, A.I. Zhuchkov, and A.V. Barskaya. Electric Discharge technologies for processing and destruction of materials. Publishing house of Tomsk Polytechnic University, Tomsk, Russia 2012. (in Russian).
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Authors and Affiliations

Igor P. Kurytnik
1
ORCID: ORCID
Ayanbergen K. Khassenov
2
ORCID: ORCID
Ulan B. Nussupbekov
2
ORCID: ORCID
Dana Z. Karabekova
2
ORCID: ORCID
Bekbolat R. Nussupbekov
2
ORCID: ORCID
Madina Bolatbekova
2
ORCID: ORCID

  1. The Witold Pilecki State Higher School, Oświęcim, Poland
  2. E.A.Buketov University of Karaganda, Kazakhstan
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Abstract

The aim of this research was to model the performances of energy and exergy on a Trombe wall system to enable an adequate thermal comfort. The main equations for the heat transfer mechanisms were developed from energy balances on subcomponents of the Trombe wall with the specification of the applicable initial and boundary conditions. During the incorporation of the PCM on the Trombe wall, the micro-encapsulation approach was adopted for better energy conservation and elimination of leakage for several cycling of the PCM. The charging and discharging of the PCM were equally accommodated and incorporated in the simulation program. The results of the study show that an enhanced energy storage could be achieved from solar radiation using PCM-augmented system to achieve thermal comfort in building envelope. In addition, the results correspond with those obtained from comparative studies of concrete-based and fired-brick augmented PCM Trombe wall systems, even though a higher insolation was used in the previous study.
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Bibliography

[1] I. Blasco Lucas, L. Hoesé, and D. Pontoriero. Experimental study of passive systems thermal performance. Renewable Energy, 19(1-2):39–45, 2000. doi: 10.1016/S0960-1481(99)00013-0.
[2] A. Mastrucci. Experimental and Numerical Study on Solar Walls for Energy Saving, Thermal Comfort and Sustainability of Residential Buildings. Ph.D. Thesis, University Politecnica delle Marche, Italy, 2013.
[3] A. Chel, J.K. Nayak, and G. Kaushik. Energy conservation in honey storage building using Trombe wall. Energy and Building, 40(9):1643–1650, 2008. doi: 10.1016/j.enbuild.2008.02.019.
[4] L. Zalewski, A. Joulin, S. Lassue, Y. Dutil, and D. Rousse. Experimental study of small-scale solar wall integrating phase change material. Solar Energy, 86(1):208–219, 2012. doi: 10.1016/j.solener.2011.09.026.
[5] C.M. Lai and C.M. Chiang. How phase change materials affect thermal performance: hollow bricks. Building Research & Information, 34(2):118–130, 2011. doi: 10.1080/09613210500493197.
[6] K. Sankaranarayanan, H.J. van der Kooi, and J. de Swaan Arons. Efficiency and Sustainability in the Energy and Chemical Industries. Scientific Principles and Case Studies. CRC Press, Boca Raton, 2010. doi: 10.1201/EBK1439814703.
[7] F. Kuznik and J. Virgone. Experimental assessment of a phase change material for wall building use. Applied Energy, 86(10):2038–2046, 2009. doi: 10.1016/j.apenergy.2009.01.004.
[8] D. Feldman, M.M. Shapiro, D. Banu, and C.J. Fuks. Fatty acids and their mixtures as phase-change materials for thermal energy storage. Solar Energy Materials, 18(3-4):201–216, 1989. doi: 10.1016/0165-1633(89)90054-3.
[9] W.I. Okonkwo and C.O. Akubuo. Trombe wall system for poultry brooding. International Journal of Poultry Science, 6(2):125–130, 2007. doi: 10.3923/ijps.2007.125.130.
[10] L. Cao, F. Tang, and G. Fang. Synthesis and characterization of microencapsulated paraffin with titanium dioxide shell as shape-stabilized thermal energy storage materials in buildings. Energy and Buildings, 72:31–37, 2014. doi: 10.1016/j.enbuild.2013.12.028.
[11] F. Abbassi and L. Dehmani. Experimental and numerical study on thermal performance of an unvented Trombe wall associated with internal thermal fins. Energy and Buildings, 105:119–128, 2015. doi: 10.1016/j.enbuild.2015.07.042.
[12] M.J. Huang, P.C. Eames, and N. J. Hewitt. The application of a validated numerical model to predict the energy conservation potential of using phase change materials in the fabric of a building. Solar Energy Materials and Solar Cells, 90(13):1951–1960, 2006. doi: 10.1016/j.solmat.2006.02.002.
[13] S.A. Ajah, B.O. Ezurike, and H.O. Njoku. A comparative study of energy and exergy performances of a PCM-augmented cement and fired-brick Trombe wall systems. International Journal of Ambient Energy, 1–18, 2020. doi: 10.1080/01430750.2020.1718753.
[14] H.O. Njoku, B.E. Agashi, and S.O. Onyegegbu. A numerical study to predict the energy and exergy performances of a salinity gradient solar pond with thermal extraction. Solar Energy, 157:744–761, 2017. doi: 10.1016/j.solener.2017.08.079.
[15] C. Ji, Z. Qin, S. Dubey, F.H. Choo, and F. Duan. Three-dimensional transient numerical study on latent heat thermal storage for waste heat recovery from a low temperature gas flow. Applied Energy, 205:1–12, 2017. doi: 10.1016/j.apenergy.2017.07.101.
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Authors and Affiliations

Benjamin O. Ezurike
1
ORCID: ORCID
Stephen A. Ajah
1
ORCID: ORCID
Uchenna Nwokenkwo
1
ORCID: ORCID
Chukwunenye A. Okoronkwo
1
ORCID: ORCID

  1. Department of Mechanical/Mechatronics Engineering, Alex Ekwueme Federal University Ndufu-Alike, Nigeria
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Abstract

Different configurations of journal bearings have been extensively used in turbomachinery and power generating equipment. Three-lobe bearing is used due to its lower film temperature and stable operation. In this study, static performance of such a bearing has been investigated at different eccentricity ratios considering lubricant compressibility and variable viscosity. The effect of variable viscosity was considered by taking the viscosity as a function of the oil film thickness while Dowson model is used to consider the effect of lubricant compressibility. The effect of such parameters was considered to compute the oil film pressure, load-carrying capacity, attitude angle and oil side leakage for a bearing working at (ε from 0.6 to 0.8) and (viscosity coefficient from 0 to 1). The mathematical model as well as the computer program prepared to solve the governing equations were validated by comparing the pressure distribution obtained in the present work with that obtained by EL-Said et al. A good agreement between the results has been observed with maximum deviation of 3%. The obtained results indicate a decrease in oil film pressure and load-carrying capacity with the higher values of viscosity coefficient while the oil compressibility has a little effect on such parameters.
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Bibliography

[1] R. Sinhasan, M. Malik, and M. Chandra. A comparative study of some three-lobe bearing configurations. Wear, 72(3):277–286, 1981. doi: 10.1016/0043-1648(81)90254-4.
[2] K. Prabhakaran Nair, R. Sinhasan, and D.V. Singh. A study of elasto-hydrodynamic effects in a three-lobe journal bearing. Tribology International, 20(3):125–132, 1987. doi: 10.1016/0301-679X(87)90042-9.
[3] K.C. Goyal and R Sinhasan. Elastohydrodynamic studies of three-lobe journal bearings with non-Newtonian lubricants. Proceedings of the Institution of Mechanical Engineers, Part C: Mechanical Engineering Science, 205(6):379–388, 1991, doi: 10.1243/PIME_PROC_ 1991_205_135_02.
[4] N.P. Mehat and S.S. Rattan. Performance of three-lobe pressure-dam bearings. Tribology International, 26(6):435–442, 1993. doi: 10.1016/0301-679X(93)90084-E.
[5] M. Malik, R. Sinhasan, and M. Chandra. Design data for three-lobe bearings. ASLE Transactions, 24(3):345–353, 2008, doi: 10.1080/05698198108983031.
[6] N.K. Batra, Gian Bhushan, and N.P. Mehta. Effect of L/D ratio on the performance of an inverted three-lobe pressure dam bearing. Journal of Engineering and Technology, 1(2):94–99, 2011.
[7] L. Roy and S.K. Kakoty. Groove location for optimum performance of three- and four-lobe bearings using genetic algorithm. Proceedings of the Institution of Mechanical Engineers, Part J: Journal of Engineering Tribology, 229(1):47–53, 2015. doi: 10.1177/1350650114541253.
[8] A. Chasalevris. Analytical evaluation of the static and dynamic characteristics of three-lobe journal bearings with finite length. Journal of Tribology, 137(4):041701, 2015. doi: 10.1115/1.4030023.
[9] A.K.H. EL-Said, B.M. EL-Souhily, W.A. Crosby, and H.A. EL-Gamal. The performance and stability of three-lobe journal bearing textured with micro protrusions. Alexandria Engineering Journal, 56(4):423–432, 2017. doi: 10.1016/j.aej.2017.08.003.
[10] D.Y. Dhande, D.W. Pande, and G.H. Lanjewar. Numerical analysis of three lobe hydrodynamic journal bearing using CFD–FSI technique based on response surface evaluation. Journal of the Brazilian Society of Mechanical Sciences and Engineering, 40(393):1–16, 2018. doi: 10.1007/s40430-018-1311-5.
[11] TVVLN Rao, A.M.A. Rani, Norani M. Mohamed, H.H. Ya, M. Awang, and F.M. Hashim. Static and stability analysis of partiaslip texture multi-lobe journal bearings. Proceedings of the Institution of Mechanical Engineers, Part J: Journal of Engineering Tribology, 234(4):567–587, 2019, doi: 10.1177/1350650119882834.
[12] P. Sinha, C. Singh, and K.R. Prasad. Effect of viscosity variation due to lubricant additives in journal bearings. Wear, 66(2):175–188, 1981. doi: 10.1016/0043-1648(81)90112-5.
[13] N.B. Naduvinamani and A.K. Kadadi. Effect of viscosity variation on the micropolar fluid squeeze film lubrication of a short journal bearing. Advances in Tribology, 2013:id743987, 2013. doi: 10.1155/2013/743987.
[14] J.R. Patel and G. Deheri. Viscosity variation effect on the magnetic fluid lubrication of a short bearing. Journal of the Serbian Society for Computational Mechanics, 13(2):56–66, 2019. doi: 10.24874/jsscm.2019.13.02.05.
[15] Q. Qu, H. Zhang, L. Zhou, and C. Wang. The analysis of the characteristics of infinitely short journal bearings modified by equivalent viscosity. 2010 International Conference on Measuring Technology and Mechatronics Automation, 754–757, 2010. doi: 10.1109/ICMTMA.2010.357.
[16] A. Siddangouda, T.V. Biradar, and N.B. Naduvinamani. Combined effects of surface roughness and viscosity variation due to additives on long journal bearing. Tribology – Materials, Surfaces & Interfaces, 7(1):21–35, 2013. doi: 10.1179/1751584X13Y.0000000024.
[17] L. Bertocchi, M. Giacopini, A. Strozzi, M.T. Fowell, and D. Dini. A mass-conserving complementarity formulation to study fluid film lubrication in the presence of cavitation for non-Newtonian and compressible fluids. Proceedings of the ASME 2012 11th Biennial Conference on Engineering Systems Design and Analysis, volume 4, pages 629–635, Nantes, France, July 2–4, 2012. doi: 10.1115/ESDA2012-82885.
[18] M. Besanjideh and S.A. Gandjalikhan Nassab. Effect of lubricant compressibility on hydrodynamic behavior of finite length journal bearings. running under heavy load conditions. Journal of Mechanics, 32(1):101–111, 2016. doi: 10.1017/jmech.2015.51.
[19] N. Tipei. Theory of Lubrication: with Applications to Liquid and Gas Film Lubrication. chapter 3, Stanford University Press, 1962.
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Authors and Affiliations

Mushrek A. Mahdi
1
ORCID: ORCID
Basim Ajeel Abbas
2

  1. University of Babylon, College of Engineering/Al-Musayab, Automobile Engineering Department, Babylon, Iraq
  2. University of Babylon, College of Engineering, Mechanical Engineering Department, Babylon, Iraq

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