The Numerical Analysis And Experimental Investigation Of The Automatic Balancing Valve

Several automatic balancing valves with different dominant discharge were designed innovatively. Numerical analyses of three-dimensional turbulent flow of different spool displacements were performed on these models. The RNG k-ε turbulence model and SIMPLE scheme based on unstructured grid system was adopted in numerical analyses. Aiming to correct the flow coefficient of spool side pore, the numerical simulation of the three-dimensional turbulent flow was carried out on the standard pore plate. The relations between pressure difference and spool displacement were obtained by numerical analyzing the flow of different spool displacement. Numerical analyses indicate that high-precision constant flow control can be obtained by using linear helical spring.In experimental investigation, we specially designed a set to test the regulating property of balancing valves, and got the relations between pressure difference and spool displacement and relations between flow and pressure difference. We also analyzed the factors involved in the precision of flow control and gave several improvements such as correcting flow coefficient of side pore using formula got from the numerical simulation of the standard pore plate, modifying the side variable pore linearly and the invariable pore. These ways improved the precision of flow control obviously.Using theoretical analysis and numerical computation, we specially studied the impacts of Young's modulus of linear helical spring on dominant discharge, precision of flow control and working pressure difference.The investigation indicates that it is feasible to optimize and predict balancing valve models by three-dimensional CFD numerical simulation. Automatic balancing valves with high precision of flow control can be obtained by combining numerical analysis and experimental investigation and can be apply to engineering.Lastly, serialization design of the automatic balancing valves were performed.