Research On Dividing Tee Resistance Reduction Method Based On Turbulent Dissipation Rate Control

In a ventilation and air conditioning system,the energy consumed by the fan can generally account for 30% to 50% of the total energy consumption of the air conditioner.Therefore,by optimizing the structure of the local components of the ventilation and air-conditioning pipeline,the local resistance of the air duct can be reduced,and the energy consumption of the wind turbine can be significantly reduced,which has important engineering significance for improving energy utilization and energy conservation.However,at this stage,there are few studies on the reduction of resistance of local components of ventilation and air conditioning.Therefore,for the ventilation duct of the air conditioning system,on the basis of exploring the mechanism of the resistance generation,the corresponding resistance analysis method is given,which is one of the problems that need to be seriously explored at present.In the past,for the convenience of research,the research on the three links was carried out only on the premise that the size of the tee was unchanged.However,in actual engineering,the pipe sizes of the downstream and tributary sections of the tees are often different from the upstream.In this paper,the variation of the local resistance coefficient of the tee and the influencing factors are obtained by analyzing the fluid flow field of different sizes of tees in the form of arc-arc line height and baffle.The research methods used in this paper are a combination of experimental research,theoretical analysis and numerical simulation.Firstly,through the theoretical analysis of the fluid,the parameters affecting the local resistance of the tees are obtained.Then,through the numerical simulation of the fluid flow field,the height and diversion of the tee pipeline at different flow ratios,different arc-changing lines anddifferent flow rates are obtained.The local resistance coefficient in the form of sheet and the velocity field,pressure field and dissipative field corresponding to it are found,and the variation law of the local resistance of the tee is found.Finally,the accuracy of the local resistance coefficient of the tee in numerical simulation and theoretical analysis is verified by experiments..Studies have shown that changing the arc height of the tee connecting section can reduce the resistance of the tee straight pipe section and the branch pipe section to a certain extent,and the drag reduction rate can be up to 38.05%.The addition of the baffle also helps to reduce the resistance of the tee straight pipe section,and the maximum drag reduction rate is 263.8%.At the same time,the turbulent energy dissipation rate equation is the best equation for characterizing the local resistance coefficient under certain conditions,which explains the theoretical mechanism of pipeline resistance to some extent.At the end of the study,the drag reduction effect of the commonly used tee size at the recommended height of the drag reducing arc is verified,and the research on the flow resistance of the ventilation and air conditioning pipeline will be promoted,which will provide a theoretical basis for the formulation of relevant standards and manuals.