Characterization of Impinged Water Spray Distribution in a Cooling Tower

• Main Authors: XIAO, YU-XIAN, 蕭瑀嫻
• Other Authors: 楊安石
• Format: Others
• Language: zh-TW
• Published: 2019
• Online Access: http://ndltd.ncl.edu.tw/handle/jjzpew

碩士 === 國立臺北科技大學 === 能源與冷凍空調工程系 === 107 === Falling film heat exchangers have been broadly utilized in the industries such as refrigeration, chemical engineering, petroleum refining processing and desalinization. The objective of this research is to perform CFD simulations and experimental measurement for investigating the liquid jet impingement and spreading behavior issued from water spray ejectors in an evaporator. The volume-of-fluid (VOF) method was utilized to simulate the liquid water-air interfacial flow motions for the water spray flow development. This study used simulation methods to illustrate the subtle characteristics of experimental measurements, and then explored the fan-shaped liquid film impact phenomenon at different flow rates(5, 7.5, 10 LPM). The collections of water distribution variability were to evaluate the effects of two different design nozzles, nozzle spacing of 12.5, 14.5 and 16.5 cm and the height of the water collecting surface of 10, 13.5 and 17.5 cm on the liquid distribution. We applied ANSYS/Fluent® CFD software to simulate the phenomenon of the liquid impact expansion process under different inlet flow condition. CFD simulations were then extended to visualize the change of the velocity direction after the fluid impact, and explore the influence of the vector velocity change at each monitoring point on the liquid expansion distribution. The experimental results show that the design A of spray nozzle under the highest flow rate and the nozzle spacing of 12.5 cm with a maximum impact angle and the highest impact point. Moreover, the height of water collecting of 17.5 cm achieve the best distribution effect.