Effects of the geometrical features of flow paths on the flow capacity of a control valve trim

Abstract

Control valves are an integral part of a number of energy systems, such as those used in chemical and nuclear industries. These valves are used to regulate the amount of fluid flow passing through these systems. A key component of a control valve is its trim, which in case of a multi-stage continuous-resistance trim consists of a staggered arrangement of columns.Flow passing through the channels formed between adjacent columns (also called as flow paths), loses a significant amount of its energy and regulates the pressure field. As the geometrical features of these flow paths dictate the flow capacity of the trim, systematic investigations have been carried out to analyse the complex flow behaviour within these flow paths. Well-verified computational fluid dynamics based solver has been used to investigate the effects of the geometrical features of flow paths on the flow capacity of the trim, at various valve opening positions. It has been noticed that reducing the size of flow paths increases the flow capacity of the trim, however, at a critical flow path size, the inherent opening characteristics of a trim have been observed to alter. In order to recover the original opening behaviour of the trim, careful manipulation of the flow paths is required, which has been successfully achieved in the present investigation.

Numerical Study of the Microflow Characteristics in a V-ball Valve

“…The flow characteristics [ 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 ] and dynamic characteristics [ 20 , 21 , 22 ] of a valve are the key indicators for judging the performance of the valve in a specific application. For the flow characteristics, research work has mainly focused on the flow coefficient.…”

“…Iravani and Toghraie [ 17 ] experimentally tested the flow characteristics of a ball valve in a compressible flow, and their results showed that the flow coefficient and loss coefficient were affected by the pressure and the flow rate and the loss coefficient had an inverse relationship with the pressure. Asim et al [ 18 ] focused on a valve trim made of a staggered arrangement of columns in a control valve, and they investigated the effects of the size of the flow path on the flow capacity and found a critical flow path size. Chern et al [ 19 ] numerically investigated the relationship between the flow coefficient and the flow cross-sectional area of the passages in a single cage and in multicages to help future valve cage design.…”

Quantification of additive manufacturing induced variations in the global and local performance characteristics of a complex multi-stage control valve trim

“…Surface roughness was not modelled in their simulations as the trim disc used in this study was considered to be hydrodynamically smooth. Asim et al [15][16][17] and Oliveira [18] adopted the approach of 3-D simulations to conduct CFD simulations on the full three-dimensional body of the valve. These simulations showed very close agreement with the results from the experimental testing.…”

“…As the VOP increases, there is an increase in the flow capacity of the valve. Asim et al [15][16][17] conducted studies on the variation of pressure and velocity within the trim and highlighted the importance of local flow analysis within the trim which could be used for the development of better designs of the trim. They observed that cavitation may occur in the flow paths within the trim as the local static pressure at some locations around the cylinders may drop below the vapour pressure under extreme conditions of operation.…”

Integration of TRIZ and CFD to New Product Development Process

“…In the flow handling equipment industry, Computational fluid dynamics (CFD) technology, is an analysis tool for monitoring and predicting flow behaviour functions by applying the equations of motion using discretised elements of a numerical model to analyse flow behaviour in a system (Asim, Charlton, and Mishra 2017) thereby saving costs by reducing over-reliance on experimental activities (Dhotre et al 2013;Goto 2016). CFD has been applied to various flow handling applications and is also useful in investigating flow path geometry changes for flow optimisation (Asim et al 2019). However, as CFD is a virtual testing and analysis tool, it does not, on its own, predict geometric design changes that would CONTACT Chino Uzoka c.uzoka2@hud.ac.uk yield the required results (Spalart and Venkatakrishnan 2016).…”