A Study on Improving the Flow Capacity of the Valves

Authors: A. G. Pradeep, Gorantla Giridhar Kumar, Vijay Turaga, Vinod Srinivasa

Abstract:

The major problem in the flow control valve is of lower Flow Capacity (Cv) which will reduce overall efficiency of flow circuit. Designers are continuously working to improve the Cv of the valve, but they need to validate the design ideas they have regarding the improvement of Cv. Traditional method of prototype and testing take a lot of time, that is where CFD comes into picture with very quick and accurate validation along with the visualization which is not possible with traditional testing method. We have developed a method to predict Cv value using CFD analysis by iterating on various Boundary conditions, solver settings and by carrying out grid convergence studies to establish correlation between the CFD model and Test data. The present study investigates 3 different ideas put forward by the designers for improving the flow capacity of the valves like reducing the cage thickness, changing the port position, and using the parabolic plug to guide the flow. Using CFD, we analyzed all design changes using the established methodology that we developed. We were able to evaluate the effect of these design changes on the Valve Cv. We optimized the wetted surface of the valve further by suggesting the design modification to the lower part of the valve to make the flow more streamlined. We could find that changing cage thickness and port position has little impact on the valve Cv. Combination of optimized wetted surface and introduction of parabolic plug improved the Cv of the valve significantly.

Keywords: Flow control valves, flow capacity, CFD simulations, design validation.

References:

[1] Sreekala, S. K., and U. Muthukumar. "Cv Value Evaluation of a Globe valve using CFD Analysis."
[2] Zhou, Xiao-Ming, Zhi-Kun Wang, and Yi-Fang Zhang. "A simple method for high-precision evaluation of valve flow coefficient by computational fluid dynamics simulation." Advances in Mechanical Engineering 9.7 (2017): 1687814017713702.
[3] Mahajan, Sahil, and Naresh Jaiswal. "Determining Flow Coefficient for Globe Valve with Different Trim shapes using a CFD Tool." International Journal of Engineering Research & Technology (IJERT) 7.10 (2018).
[4] Praveen, J. V. S., and Mehboob Pathan. "Flow coefficient analysis for a globe valve by using CFD." Int J Sci Res 6 (2017): 756-763.
[5] Yevale, Swapnil R., and K. S. Gharge. "A Review on CFD Analysis of Control Valves."
[6] https://www.theprocesspiping.com/introduction-to-globe-valve/
[7] https://kimray.com/training/what-valve-flow-coefficient-cv
[8] https://www.electricalvolt.com/2021/11/measurement-of-control-valve-flow-coefficient-cv/