Investigation on the cooling performance of mechanical draft dry-wet hybrid cooling tower. (25th June 2023)

• Record Type: Journal Article
• Authors: Zhao, Cuilin; Wang, Mingwei; Gao, Qi; Cheng, Shen; He, Suoying; Zhao, Jifang; Zhan, Jianwei; Liu, Zhilan; Geng, Zhe; Zhang, Shuzhen; Qi, Jianhui; Gao, Ming; Shi, Yuetao
• Is Part Of: Applied thermal engineering. Volume 228(2023)
• Publication Date: 2023-06-25
• Subjects: Mechanical draft dry cooling tower -- Dry-wet hybrid cooling -- Cooling performance -- Control strategy; Heat engineering -- Periodicals; Heating -- Equipment and supplies -- Periodicals; Periodicals; 621.40205
• DOI: 10.1016/j.applthermaleng.2023.120473
• Languages: English
• ISSNs: 1359-4311

Abstract

Highlights: Cooling performances of MDDCTs pre-cooled with six wet media were compared. Media were CELdek7060, CELdek7090, CELdek5090, PVC1200, Trickle125 and Trickle100. 300 mm CELdek7060 is promising to improve cooling performance of studied MDDCT. Hybrid cooling and raising fan speed can improve MDDCT's performance by 92.04%. Abstract: To address the problem of poor cooling performance of mechanical draft dry cooling tower (MDDCT) at high ambient temperatures, this paper proposes a dry-wet hybrid cooling technology to evaporatively cool the inlet air of the MDDCT using wet media. A MATLAB iterative program of the dry-wet hybrid cooling tower is established, and the influences of the medium type and thickness, ambient temperature, humidity and the fan speed on the cooling performance of the dry-wet hybrid cooling tower and its performance control strategy are investigated. The results show that: (1) The cooling performance of the dry-wet hybrid cooling tower is better than that of the MDDCT during high ambient temperatures; (2) The cooling performance of the studied 12.5 m high MDDCT can be improved by 71.32 % (the heat rejection rate increases from 2.72 MW to 4.66 MW) using 300 mm CELdek7060 medium for hybrid cooling at the ambient temperature of 30 ℃ and humidity of 20 %; (3) The increase in the fan speed from 80 r/min to 160 r/min can improve the cooling performance of both the MDDCT by 89.73 % (the heat rejection rate increases from 1.85 MW to 3.51 MW) and the 300 mm CELdek7060 hybrid cooling tower by 92.04 % (the heat rejection rate increases from 3.14 MW to 6.03 MW); (4) Based on the meteorological data of Hami in Xinjiang in the year of 2020, the investigation on the control strategy reveals that the fan speed should be raised from 120 r/min to the maximum 333 r/min at the medium thickness of 300 mm to meet the 5 ℃ temperature drop in July (i.e., the hottest month).