Article
Mechanics
Di Fang, Yan Xiang, Yucheng Deng, Weimin Ma
Summary: In this study, the numerical simulation shows that the dynamics of the liquid film resulting from multi-nozzle spray cooling agrees well with experimental observation. It is also found that a decreasing nozzle-to-surface distance results in a thicker liquid film, lower velocity, and increased non-uniformity. Furthermore, the layout of the nozzle array has little influence on average liquid film thickness and velocity but significantly affects the film morphology.
INTERNATIONAL JOURNAL OF MULTIPHASE FLOW
(2023)
Article
Thermodynamics
Yuming Lu, Hongzi Fei, Hao Yang, Yiyong Huang, Hai Zhang
Summary: The selection of organic cooling mediums in injection cooling significantly affects the cooling effect, while most research focuses on water. The evaporation of organic cooling mediums such as ethanol can assist combustion, but research on their cooling effect is relatively lacking. Tests on organic working fluids show that the evaporation and cooling effect of ethanol solutions improve with increased concentration. Not all organic cooling mediums bring good temperature drop and evaporation effects. Higher airflow temperature enhances the cooling effect of working mediums, while the liquid-gas ratio has almost no influence on temperature drop.
APPLIED THERMAL ENGINEERING
(2022)
Article
Engineering, Environmental
Natalie Schmidt, Jens Denecke, Juergen Schmidt, Michael Davies
Summary: A new CFD model has been developed to accurately calculate storage tank breathing during cooldown in heavy rain events. The model evaluates temperature stratification, convection, and heat transfer inside the tank, as well as the presence of a rain film on the outside. It uses Euler and multiphase models for non-condensable and condensable substances, respectively, and has been validated against experimental data.
PROCESS SAFETY AND ENVIRONMENTAL PROTECTION
(2023)
Article
Thermodynamics
Huimin Pang, Chunrong Zhao, Shen Cheng, Mingwei Wang, Qi Gao, Suoying He, Gengsheng Sun, Guangxu Jiang, Qinggang Sun, Zhilan Liu, Zhe Geng, Shuzhen Zhang, Ming Gao
Summary: Nozzle spray pre-cooling can enhance the thermal performance of natural draft dry cooling towers (NDDCTs) by cooling the inlet air. A 3-D model of spray pre-cooled NDDCT was created to determine the optimal nozzle arrangement. The simulation results indicate that the ideal nozzle arrangement height is between 3-13 m, and the feasible nozzle radiuses vary with height. Additionally, different spray angles are suitable for different height zones.
THERMAL SCIENCE AND ENGINEERING PROGRESS
(2023)
Article
Thermodynamics
Huimin Pang, Mingwei Wang, Qi Gao, Shen Cheng, Zhilan Liu, Zhe Geng, Shuzhen Zhang, Suoying He, Tiantian Liu, Cuilin Zhao, Wangrui Liu, Ming Gao
Summary: In this study, a 3-D model was established using Fluent 16.2 to investigate the spray zones of a 120 m high natural draft dry cooling tower (NDDCT) under crosswind conditions. The results show that the nozzle height should be set at 7 m for a crosswind speed of 0 m/s, and 9 m for crosswind speeds of 2-10 m/s. The feasible spray angles of the nozzles are 0 degrees for crosswind speeds of 0-4 m/s, and 90 degrees for crosswind speeds of 6-10 m/s. The feasible nozzle radiuses also vary under different crosswind conditions.
INTERNATIONAL JOURNAL OF REFRIGERATION
(2023)
Article
Thermodynamics
Rui Chen, Deying Zhang, Zhengqing Zhang, Qiang Han, Suoying He, Ming Gao
Summary: This study utilized non-equidistant fillings to enhance the thermal performance of wet cooling towers, with simulation results indicating that the relatively optimal combination is to arrange 30 mm fillings in the inner zone and 26 mm fillings in the outer zone. As the inner zone radius increases, the water temperature drop, cooling efficiency, and Merkel number first rise and then decline.
CASE STUDIES IN THERMAL ENGINEERING
(2021)
Article
Thermodynamics
Linyi Xiang, Yanhua Cheng, Xingjian Yu, Yiwen Fan, Xuan Yang, Xinfeng Zhang, Bin Xie, Xiaobing Luo
Summary: In this study, a high-performance spray cooling system for high-power LEDs is designed and established, and the influence of nozzle configuration, flow rate, and nozzle-to-surface distance on the heat transfer characteristics are investigated. The system shows excellent heat dissipation capacity, and the double-nozzle configuration exhibits the highest single-phase heat transfer coefficient. The proposed cooling system has the potential to reduce energy consumption and promote the utilization of low-grade thermal energy in cooling high-power LEDs.
APPLIED THERMAL ENGINEERING
(2023)
Article
Mechanics
Hirotaka Maeyama, Soshi Kawai
Summary: Near-wall turbulence structures and generation in the wall-modelled large-eddy simulation (WMLES) are investigated by comparing with direct numerical simulation (DNS). The near-wall statistical structures producing turbulence are found to exist even in the WMLES, although they are numerically elongated. The near-wall turbulence structures in the WMLES are suggested to be coherent structures with alternating low- and high-speed fluids in the spanwise direction.
JOURNAL OF FLUID MECHANICS
(2023)
Article
Energy & Fuels
Chu-Qi Su, Shuo Wang, Xun Liu, Qi Tao, Yi-Ping Wang
Summary: In this study, a method of spray cooling the radiator using water produced by the fuel cell was proposed to address the heat transfer problem in fuel cell vehicles during climbing and high temperature conditions. A test bench was constructed to evaluate the effectiveness of this method and determine the optimal spray working conditions. Numerical simulation and experimental verification were conducted to study the convective heat transfer coefficient of the radiator's air side. The results demonstrated that inclined spray was more effective than vertical spray, and the numerical simulation process provided valuable reference for the design of fuel cell vehicle spray cooling system.
Article
Thermodynamics
Suoying He, Yang Li, Mingwei Wang, Aiping Wang, Abdullah M. Alkhedhair, Hongjun Guan, Xuehong Wu, Yuetao Shi, Ming Gao
Summary: This study investigates the control mechanism of a spray pre-cooling system for performance improvement of natural draft dry cooling towers. It develops a 3-D model to simulate a 120 m high tower and explores the effects of spray angles, nozzle arrangement, and water flowrates. The findings suggest optimized schemes for maximal cooling performance improvement with minimal water consumption, as well as recommendations for achieving uniform cooling.
APPLIED THERMAL ENGINEERING
(2022)
Article
Thermodynamics
Yi Jin, Lu Lu, Ziwei Huang, Xingsi Han
Summary: This study investigates film cooling using a newly developed VLES method and compares it with other turbulence modelling methods. The results show that different turbulence methods produce significantly different results at low momentum flux ratios, while the differences become less significant at higher ratios. The study demonstrates the potential of the VLES method for accurately predicting complex film cooling problems.
INTERNATIONAL JOURNAL OF THERMAL SCIENCES
(2022)
Article
Thermodynamics
P. Navarro, J. Ruiz, A. S. Kaiser, M. Lucas
Summary: This paper focuses on the experimental optimization of the thermal performance of a new prototype of a forced, mechanical-draft, wet, inverted cooling tower. The effects of fill length and nozzle arrangement on the tower's operation were investigated. The results show that the upper manifold performs better than the intermediate and lower manifolds, and the fill length of 1.6 m provides the best performance.
APPLIED THERMAL ENGINEERING
(2023)
Article
Energy & Fuels
Guodong Gai, Abdellah Hadjadj, Sergey Kudriakov, Stephane Mimouni, Olivier Thomine
Summary: This study investigates the spray-induced turbulence generated from industrial spray nozzles through numerical simulations to better understand its role in fires or explosions. The validation of the polydisperse model for predicting gas and droplet velocities is crucial, and the distribution characteristics of turbulent kinetic energy and integral length scale inside and outside the spray cone are examined.
Article
Engineering, Multidisciplinary
Zhang ZhiWei, Hu DingHua, Li Qiang, Liu Chao, Zhou Fan
Summary: The study reveals that increasing superheat results in finer droplets and thinner liquid film, improving heat transfer efficiency. Expanding atomization angle benefits in reducing spray distance in flash spray cooling. The choice of nozzle is crucial for the cooling performance in flash spray, depending on the superheat level.
SCIENCE CHINA-TECHNOLOGICAL SCIENCES
(2021)
Article
Thermodynamics
Danyal Mohaddes, Philipp Boettcher, Matthias Ihme
Summary: This study investigates the thermal ignition of liquid n-dodecane fuel spray on a hot surface, focusing on ignition characteristics and flame propagation mechanisms in different temperature regimes. Through experimental simulation, fundamental understanding of the physical phenomena involved in the process is provided towards the goal of improved industrial safety.
COMBUSTION AND FLAME
(2021)
Article
Engineering, Chemical
Qiang Xie, Zuobing Chen, Qinfu Hou, A. B. Yu, Runyu Yang
Article
Thermodynamics
Qiang Xie, Zuobing Chen, Gong Chen, Yongjie Yu, Zheyu Zhao
Article
Geochemistry & Geophysics
Chang Liu, Zuobing Chen, Ya Mao, Zhiming Yao, Weili Zhang, Weidong Ye, Yuanyuan Duan, Qiang Xie
Summary: This study focuses on the energy consumption and grinding efficiency of a laboratory vertical roller mill. By using response surface method and multi-objective optimization design method, the influence of operating parameters on energy consumption and grinding efficiency is systematically investigated. A set of optimal parameters is obtained, providing reliable guidance for reducing energy consumption and improving grinding efficiency.
Article
Chemistry, Physical
Chengguang Tong, Zuobing Chen, Chang Liu, Qiang Xie
Summary: This study investigates the effects of stirrer helix angle (a), stirrer diameter (d), and rotating speed (n) on the grinding performance of an industrial vertical stirred mill (VSM) using the discrete element method (DEM) and the response surface method (RSM). The optimized parameters show significant improvements in media collision effects and energy conversion rate.
Article
Chemistry, Multidisciplinary
Yunqing Yu, Shuisheng Xu, Mei Wang, Qiang Xie
Summary: This study developed a multi-point spacing measuring system based on the eddy current sensing principle, which has a simple structure and high measurement accuracy. By simultaneously obtaining measurement data from multiple points and using LabVIEW program for processing, efficient and accurate measurement results were obtained. Experimental tests showed that the system has shorter measurement duration and smaller error uncertainty compared to traditional manual operations, demonstrating better efficiency and precision.
APPLIED SCIENCES-BASEL
(2023)
Article
Thermodynamics
Qiang Xie, Zuobing Chen, Ya Mao, Gong Chen, Weiqiang Shen
CASE STUDIES IN THERMAL ENGINEERING
(2018)
