Computational Simulation And Experimental Research On The Bidirectional Inside And Outside Tu Be Differential Pressure Flowmeter

Flow measurement is the basis for flow control, differential pressure flowmeter is widely used in industrial production. V cone flowmeter appearance opens up a new field of the development of differential pressure flowmeter. But the V-Cone still has some deficiencies because of its own structure.For structural defects, it was suggested that the double cone and the inside and outside tube differential pressure flowmeter. Combining the advantages of the two flowmeters, the paper proposed a new differential pressure flowmeter – the bidirectional inside and outside tube differential pressure flowmeter.Combining with the theoretical analysis, the paper used a fluid simulation software FLUENT to simulate the bidirectional inside and outside the tube differential pressure flowmeter workfield at DN32 diameter for study the characteristics of the flowmeter, comparative analysised the performance of the bidirectional inside and outside tube differential pressure flowmeter, double-cone flowmeter and the inside and outside tube differential pressure flowmeter with some experiments. The main work of this thesis as follows:1) Paper analyzed the principle of the bidirectional inside and outside tube differential pressure flowmeter., established theoretical model; referring to other differential pressure flowmeter, the equivalent diameter ratio of the bidirectional inside and outside tube differential pressure flowmeter was defined; defined the flow spliting through analyzing of the characteristics of the flowmeter ratio. Three main factors affecting the performance of the bidirectional inside and outside tube differential pressure flowmeter are: divergence angle θ, the equivalent diameter ratio β and flow spliting ratio α.2) Paper optimized the divergence angle by FLUENT, and created some different equivalent diameter ratio and different flow spliting ratio models with the optimized divergence angle,The principle how the equivalent diameter ratio and flow spliting ratio affect the bidirectional inside and outside tube differential pressure flowmeter performance by calculating and analyzing these models: Pressure loss and pressure signal of the flowmeter increases as the equivalent diameter ratio decreases and the Reynolds number increases, the pressure loss ratio increases as the Reynolds number increases; in a certain equivalent diameter ratio, pressure loss ratio increases first and then decreases as the flow spliting ratio increases, and the higher equivalent diameter ratio, the smaller flow spliting ratio to the maximum pressure loss ratio; efflux coefficient is stable in low flow spliting ratio at low Reynolds number,at high Reynolds number efflux coefficient is stable in high flow splitting ratio.3) In the same equivalent diameter ratio, paper compared the performance of the three kinds of flowmeter: energy efficiency and accuracy of the bidirectional inside and outside tube differential pressure flowmeter is better than the other two flowmeter, its sensitivity is slightly worser than the inside and outside tube differential pressure flowmeter.The results are verified by experiment and the error of efflux coefficient is about 2%.