Journal of Water and Wastewater; Ab va Fazilab (in persian)

Journal of Water and Wastewater; Ab va Fazilab (in persian)

Applying Dynamic Air Cooling System to Reduce Water Consumption of Iranian-Made Evaporative Coolers

Document Type : Technical Note

Author
Behzad Omidi Kashani
Assist. Prof. of Mechanical Engineering, Dept. of Mechanical Engineering, Faculty of Engineering, University of Birjand, South Khorasan, Iran
10.22093/wwj.2025.499350.3459
Abstract
The considerable water consumption associated with Iranian-produced evaporative coolers is evident given Iran’s water shortage and diminishing water resources in Iran. Although Iranian-produced evaporative coolers have an older design and are well suited to the atmospheric conditions of Iran, which are mainly hot and semi-arid, their high water consumptions and the lack of water resources, particularly in summer, highlights the need for more scientific research. This should include new ideas and techniques aimed to reduce water consumption in these devices. In this study, a new dynamic air cooling system is introduced, by which atmospheric air can be cooled to -90 oC without the use of conventional refrigeration systems. The dynamic air cooling system represents a novel and innovative method on a global scale.Based on the scientific principles of gas dynamics and thermodynamics, it is able to increase the speed of air passing through this system to supersonic values in several stages, consequently reducing the temperature of the air passing through the system or its sensible energy, significantly. This innovative system is currently being used commercially in industrial cold stores. In the current work, by using the cold air produced by this system, the temperature of the circulating water in evaporative water coolers is significantly reduced, and the amount of water consumption in evaporative water coolers is reduced. It is shown that by using the cold air produced by the dynamic cooling system, the temperature of the circulating water is reduced from the wet bulb temperature of the ambient air to a temperature of 4 oC; in these conditions, the cooling load and the seasonal energy efficiency ratio increase by 97% and 29.2%, respectively, while the water consumption rate and specific water consumption decrease by 35.2 and 67.5%, respectively. Therefore, by using this system in evaporative water coolers produced in Iran, the water and energy consumption rates are both significantly reduced.
Keywords
Evaporative Water Cooler
Dynamic Air Cooling
Water Consumption Reduction
Efficiency Increase
Temperature of Water Circulation
Al-Badri, A. R. and Al-Waaly, A. A. Y., 2017. The influence of chilled water on the performance of direct evaporative cooling. Energy and Buildings, 155, 143-150. https://doi.org/10.1016/j.enbuild.2017.09.021.
Alsaghir, A. M., Hamdan, M. O. and Orhan, M. F., 2021. Evaluating velocity and temperature fields for Ranque–Hilsch vortex tube using numerical simulation. International Journal of Thermofluids, 10, 100074. https://doi.org/10.1016/j.ijft.2021.100074.
ASHRAE, 2015. Method of Testing Direct Evaporative Air Coolers. Supersedes ANSI/ASHRAE Standard 133-2008. ISSN: 10412336. US: ASHRAE. [Link]
Don, W. G. and Robert, H. P., 2008. Perry's Chemical Engineers' Handbook, Eighth Edition, New York, McGraw-Hill Education.
Facciolo, L., 2006. A study on axially rotating pipe and swirling jet flows (Doctoral dissertation, KTH). [Link]
He, S., Guan, Z., Gurgenci, H., Jahn, I., Lu, Y. and Alkhedhair, A. M., 2014. Influence of ambient conditions and water flow on the performance of pre-cooled natural draft dry cooling towers. Applied Thermal Engineering, 66, 621-631. https://doi.org/10.1016/j.applthermaleng.2014.02.070.
Hu, Z., Wang, D., Gao, F., Cao, Y. and Wu, H., 2023. Experimental investigation on cooling performance of vortex tube with rectifier using Taguchi method. Case Studies in Thermal Engineering, 49, 103373. https://doi.org/10.1016/j.csite.2023.103373.
Huang, L. and El-Genk, M. S., 1998. Heat transfer and flow visualization experiments of swirling, multi-channel and conventional impinging jets. International Journal of Heat and Mass Transfer, 41, 583-600. https://doi.org/10.1016/S0017-9310(97)00123-3.
Hussain, I., Bibi, F., Bhat, S. A., Sajjad, U., Sultan, M., Ali, H. M. et al., 2022. Evaluating the parameters affecting the direct and indirect evaporative cooling systems. Engineering Analysis with Boundary Elements, 145, 211-223. https://doi.org/10.1016/j.enganabound.2022.09.016.
Nozaki, A., Igarashi, Y. and Hishida, K., 2003. Heat transfer mechanism of a swirling impinging jet in a stagnation region. Heat Transfer-Asian Research, 32, 663-673. https://doi.org/10.1002/htj.10120.
Omidi Kashani, B. and Deymi, O., 2021. Investigating the correct operation of domestic water meters in the range of water consumption of evaporative coolers according to the different atmospheric conditions for four cities of South Khorasan Province. Journal of Water and Wastewater, 32(3), 40-54. (In Perian) https://doi.org/10.22093/wwj.2020.250004.3067.
Omidi Kashani, B., 2015. The process of optimizing water evaporative coolers by adjusting the volume rate of circulating water. Iran patent application. (In Persian)
Omidi Kashani, B., 2017. The need for economical water efficiency labels on appliances such as water coolers and practical solutions to enhance the efficiency label. Iran Water and Wastewater Science Engineering Congress. Tehran: Iranian Water and Wastewater Association. (In Persian). [Link]
Omidi Kashani, B., 2022. Increase of energy efficiency ratio of a direct evaporative cooler by dynamic behavior with energy and exergy analysis. Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science, 236, 3818-3830. https://doi.org/10.1177/09544062211042051.
Rathakrishnan, E., 2019. Applied Gas Dynamics, John Wiley & Sons Ltd. 2nd Edition, Indian Institute of Technology Kanpur, India. [Link]
Razumtseva, O., Razumtsev, O. and Panasjuk, P., 2023. A refrigeration unit with dynamic air cooling and a working element of the unit. United States patent application 17/759,848. Publication of US20230129766A1. [Link]
Sellam, S. H., Moummi, A., Mehdid, C. E., Rouag, A., Benmachiche, A. H., Melhegueg, M. A. et al., 2022. Experimental performance evaluation of date palm fibers for a direct evaporative cooler operating in hot and arid climate. Case Studies in Thermal Engineering, 35, 102119. https://doi.org/10.1016/j.csite.2022.102119.
Teng, S. and Xi, H., 2022. Experimental evaluation of vortex tube and its application in a novel trigenerative compressed air energy storage system. Energy Conversion and Management, 268, 115972. https://doi.org/10.1016/j.enconman.2022.115972.
Wongcharee, K., Kunnarak, K., Chuwattanakul, V. and Eiamsa-Ard, S., 2020. Heat transfer rate of swirling impinging jets issuing from a twisted tetra-lobed nozzle. Case Studies in Thermal Engineering, 22, 100780. https://doi.org/10.1016/j.csite.2020.100780.
Xu, L., Yang, T., Sun, Y., Xi, L., Gao, J., Li, Y. et al., 2021. Flow and heat transfer characteristics of a swirling impinging jet issuing from a threaded nozzle. Case Studies in Thermal Engineering, 25, 100970. https://doi.org/10.1016/j.csite.2021.100970.
Zucker, R. D. and Biblarz, O., 2019. Fundamentals of Gas Dynamics, John Wiley & Sons, Inc. 3rd Edition. [Link]
Journal of Water and Wastewater; Ab va Fazilab (in persian)
Volume 36, Issue 4 - Serial Number 159
November and December 2025
Pages 97-114