The Study Of Measures To Control Visible Plume Of Mechanical Draft Cooling Tower

Cooling tower without visible plume is a type of which finned tube is installed contrasted with the traditional cooling tower, use the heat convection of finned tubes and cooling tower air to increase the outlet air temperature of the cooling tower, avoid visible plume mixed with the atmosphere. The visible plume of cooling tower often make people mistakenly believe that fire and harmful pollutants in densely populated areas and is apt to cause panic, cause social harm. In recent years, because of the visible plume of cooling tower generating social awareness of environmental protection has attracted much attention. At present, research on cooling tower without visible plume is less, so this article start the research and analyze of the overall design of cooling tower without visible plume system preliminarily.Firstly, the article introduce the reason for the cooling tower of visible plume and the environmental hazards of visible plume, and cooling tower of visible plume were analyzed from the theory, put forward by changing the cooling tower structure such as installing finned tubes, electric heating equipment etc. to prevent visible plume, and compare the advantages and disadvantages of various options. After considering various factors, choose finned tube to study the visible plume cooling tower.Secondly, according to the position of finned tubes, the cooling tower will be divided into different series and parallel in two forms, Taking into account the corrosion and the impact of finned tubes for air duct resistance to optimize the structure design of finned tubes. After determining finned tube hot convective equilibrium equations and numerical simulation equations,we take finned tube heat transfer coefficient for the optimization target and use orthogonal experimental method to determine the structure of finned tubes, Through theoretical analysis and numerical simulation of two FLUENT species method, we study the influence of finned tube structure parameters:base tube diameter, fin pitch, fin thickness, fin height and other factors to the convection heat transfer.Thirdly, we study the weather conditions of large commercial buildings which produces visible plume, and through controlling the number of the operating cooling tower and fan speed, collect a variety of combinations of operating conditions data, we can get conclusion that a reasonable operating policy can be a effective method to control and reduce the generation of visible plume. Considering the economic and feasibility of the solar collector system is used in the cooling tower without visible plume, solar collectors investment costs and operating costs are relatively low, so it is an ideal solution for cooling tower without visible plume. Due to the different properties of the fluid, solar hot water collectors bring less energy consumption, lower operating costs than the solar air collector, the paper choose solar hot water collectors as an auxiliary heat source for cooling tower without visible plume system.Finally, through summarizing the achievements and defects of the cooling tower without visible plume, can provide reference for the study in the future.