Ventilating electrical rooms with intense heat emission sources is imperative to prevent workers’ injury and damage to equipment. This paper investigates by means of computational fluid dynamics (CFD) the performance of seven proposed ventilation schemes for a multi-zone transformer room of an indoor substation in Beirut city. To this end, an indoor multi-zone substation with four transformers was simulated using ANSYS/Fluent 15.0 with different proposed ventilation schemes. The location of inlet louvers was fix, while the positions of four exhaust outlets were changed throughout the CFD simulations to determine the best-case scenario providing the lowest levels of temperatures in the operating zone and in the vicinity of transformers. The analysis showed that the cooling effect improves as the elevation of the exhaust fans decreases. The obtained results can be used to make some recommendations for design and optimization of similar ventilation projects of indoor transformer rooms.
ventilation schemes, numerical modeling, transformer substation, turbulent flow, thermal field
 IEC 62271-202. (2006). High-voltage switchgear and controlgear, part 202: high voltage/low voltage prefabricated substations. IEC Standard.
 Hua Z, Min R, Neng G, Bu Y. (1993). 35-110 kV Substation Design (GB50059-92). China Planning Press, China.
 IEC 60076-2. (1997). Power transformers, part 2: temperature rise. IEC Standard, 2nd ed.
 Menheere WMM. (1995). Transformer stations and natural ventilation. CIRED 13th International Conference on Electricity Distribution, Brussels, Belgium, pp. 1-23.
 Radakovic Z, Maksimovic S. (2002). Non-stationary thermal model of indoor transformer stations. Electrical Engineering Archiv fur Elektrotechnik 84(2): 109-117. http://dx.doi.org/ 10.1007/s00202-001-0111-5
 Iskender I, Mamizadeh A. (2011). An improved nonlinear thermal model for MV/LV prefabricated oil-immersed power transformer substations. Electrical Engineering Archiv fur Elektrotechnik 93(1): 9-22. http://dx.doi.org/ 10.1007/s00202-010-0186-y
 Hurtado JP, Acuna EI. (2015). CFD analysis of 58 Adit main fans parallel installation for the 2015-2019 underground developments of the new level mine project. Applied Thermal Engineering 90:1109-1118. http://dx.doi.org/ 10.1016/j.applthermaleng.2015.05.014
 Liu Y, Wang S, Deng Y, Ma W, Ma Y. (2016). Numerical simulation and experimental study on ventilation system for powerhouses of deep underground hydropower stations. Applied Thermal Engineering 105: 151-158. http://dx.doi.org/ 10.1016/j.applthermaleng.2016.05.101
 Ye WB. (2017). Design method and modeling verification for the uniform air flow distribution in the duct ventilation. Applied Thermal Engineering 110: 573-583. http://dx.doi.org/ 10.1016/j.applthermaleng.2016.08.177
 Lu KH, Mao SH, Wang J, Lu S. (2017). Numerical simulation of the ventilation effect on fire characteristics and detections in an aircraft cargo compartment. Applied Thermal Engineering 124: 1441-1446. http://dx.doi.org/ 10.1016/j.applthermaleng.2017.06.128
 Loucaides N, Ioannides Y, Efthymiou V, Georghiou GE. (2010). Thermal modeling of power substations using the finite element method. 7th Mediterranean Conference and Exhibition on Power Generation, Transmission, Distribution and Energy Conversion (MedPower 2010), Agia Napa, Cyprus, pp. 1-5.
 Ramos JC, Rivas A, Morcillo JM. (2005). Numerical thermal modelling of the natural ventilation of a half-buried transformer substation using CFD techniques. Progress in Computational Heat and Mass Transfer 2: 929-934.
 Vega MG, Díaz KMA, Oro JMF, Tajadura RB, Morros CS. (2008). Numerical 3D simulation of a longitudinal ventilation system: memorial tunnel case. Tunnelling and Underground Space Technology 23(5): 539-551. http://dx.doi.org/ 10.1016/j.tust.2007.10.001
 Kanaan M, Ghaddar N, Ghali K. (2016). Localized air-conditioning with upper-room UVGI to reduce airborne bacteria cross-infection. Building Simulation 9(1): 63-74. http://dx.doi.org/ 10.1007/s12273-015-0250-7
 Voelker C, Diewald M. (2015). CFD simulation and measurement of the heat transfer from building material specimens to the indoor environment. 14th Conference of International Building Performance Simulation Association, Hyderabad, India, pp. 891-896.
 ANSYS Inc. ANSYS15.0.7 – Engineering Simulation and 3-D Design Software.