Research On Structure Optimization Of Air-cooled And Evaporative Combined Cooling Tower

The air-cooled and evaporative combined cooling tower is a cooling tower that operates under multiple operating conditions.The heat-transferring coils are connected in series with finned tubes in the air-cooled zone and smooth tubes in the evaporative cooling zone.The upper part of the smooth tube is equipped with a spray device.,The opening and closing of the spray device can be controlled according to user needs.The advantage of the combined tower is that different operating modes can be switched through different weather parameters in different seasons,and the purpose of saving water,energy saving and consumption reduction can be achieved under the condition of ensuring the cooling water demand.This paper combines Matlab numerical calculation and Visual basic application development,and studies the structural layout and operation mode of the air-cooled and evaporative combined type.First of all,this topic combines the structure and operating characteristics of air-cooled and evaporative combined cooling towers,starting from the basic theory of heat and mass transfer inside the air-cooled zone and evaporative cooling zone,based on reasonable assumptions and simplified models.,Established the mathematical model of the combined cooling tower,and gave the method of determining the key parameters in the mathematical model,which provided theoretical support for the design and calculation of the subject.Secondly,because the combined cooling tower has a more complex structure than traditional cooling towers and has many influencing factors,it is necessary to explain in detail the entire process of heat transfer area design and calculation through specific examples.On this basis,Matlab software is used to compile relevant calculation programs,and the mathematical models of the cold zone and the evaporative cooling zone have been verified.The comparison between the calculated value of Matlab and the experimental value of the literature shows that the relative error is within the acceptable range,which confirms the accuracy of the mathematical model.Finally,the heat transfer area changes of the finned tube and the smooth tube under the design parameters of the most unfavorable temperature in summer and the most unfavourable temperature in winter are discussed,and the influence of different design conditions on the heat transfer area is analyzed.On this basis,the economical optimization design of the air-cooled and evaporative combined cooling tower was carried out,and the structural parameters suitable for the four seasons were obtained.The seasonal operation mode of the combined tower was discussed,and the climate switching node of the operation mode was obtained.,And the definite equation of how operating parameters are adjusted with changes in meteorological parameters.In addition,for actual engineering needs,the heat transfer area calculation software for air-cooled and evaporative combined cooling towers has been developed through Visual Basic,which can calculate the corresponding heat transfer area and structural parameters according to different requirements for faster and more direct to get the calculated result...