Optimal Water Conservation in a Mechanical Cooling Tower Operations

Authors: M. Boumaza, Y. Bakhabkhi

Abstract:

Water recycling represents an important challenge for many countries, in particular in countries where this natural resource is rare. On the other hand, in many operations, water is used as a cooling medium, as a high proportion of water consumed in industry is used for cooling purposes. Generally this water is rejected directly to the nature. This reject will cause serious environment damages as well as an important waste of this precious element.. On way to solve these problems is to reuse and recycle this warm water, through the use of natural cooling medium, such as air in a heat exchanger unit, known as a cooling tower. A poor performance, design or reliability of cooling towers will result in lower flow rate of cooling water an increase in the evaporation of water, an hence losses of water and energy. This paper which presents an experimental investigate of thermal and hydraulic performances of a mechanical cooling tower, enables to show that the water evaporation rate, Mev, increases with an increase in the air and water flow rates, as well as inlet water temperature and for fixed air flow rates, the pressure drop (ΔPw/Z) increases with increasing , L, due to the hydrodynamic behavior of the air/water flow.

Keywords: water, recycle, performance, cooling tower

Digital Object Identifier (DOI): doi.org/10.5281/zenodo.1331739

References:

[1] N. Milosavljevic, P. Heikkila, A comprehensive approach to cooling tower design, Applied Thermal Engineering 21 (2001) 899−915.
[2] J. C. Kloppers, D. G. Kröger, Refinement of the transfer characteristic correlation of wet cooling tower fills, Heat Transfer Engineering 26 (4) (2005) 35−41.
[3] E. Elsarrag, Experimental study and predictions of an inclined draft ceramic tile packing cooling tower, Energy Conversion and Management 47 (2006) 2034−2043.
[4] F. Gharagheizi, R. Hayati, S. Fatemi, Experimental study on the performance of mechanical cooling tower with two types of film packing, Energy Conversion and Management 48 (2007) 277−280.
[5] J. E. Braun, Methodologies for the design and control of central cooling plants, PhD Thesis, Mechanical engineering, University of Wisconsin−Madison, USA, 1988.
[6] J. C. Kloppers, A critical evaluation and refinement of the performance prediction of wet cooling towers, PhD Thesis, Mechanical engineering, University of Stellenbosch, South Africa, 2003.
[7] B. A. Qureshi, S. M. Zubair, A complete model of wet cooling towers with fouling in fills, Applied Thermal Engineering 26 (2006) 1982−1989.
[8] Y. I. Ignatenkov, Study and elaboration of a method for calculating optimum parameters of mass exchange apparatuses with vertical grids, Doctorate Thesis, Institute of Leningrad, 1979.
[9] M. Lemouari, M.Boumaza: An experimental investigation of thermal characteristics of a draft wet cooling tower, in: Proceedings 13th IAHR Symposium in cooling towers, Poitiers, France, 2005.
[10] M. Lemouari, M. Boumaza, M. Mujtaba: Thermal performances investigation of a wet cooling tower, Applied Thermal Engineering 27 (2007) 902−909.
[11] M. Lemouari, M. Boumaza, A.Kaabi:: Experimental analysis of heat and mass transfer phenomena in a direct contact evaporative cooling tower, Energy conversion management, 50, 2009.
[12] F. Merkel, Verdunstungskuehlung, VDI Forschungsarbeiten, no. 275, Berlin, 1925.
[13] R. E. Treybal, Mass Transfer operations, Third ed., McGraw-Hill, 1980.Instruction manual: Basic water cooling tower, Engineering Teaching and Research Equipment, Armfield, England, 1993.
[14] W. K. Hutchison, E. Spivey, Design and performance of cooling towers, Trans. Inst. Chem. Eng. 20 (1942) 14−29.
[15] A. M. London, W. E. Mason, L. M. K. Boelter, Performance characteristics of a mechanically induced draft counterflow packed cooling tower, Trans. A. S. M. E. 62 (1940) 41−50.