Proceedings of the Thirty-second (2022) International Ocean and Polar Engineering Conference
Shanghai, China, June 5–10, 2022
Copyright © 2022 by the International Society of Offshore and Polar Engineers (ISOPE)
ISBN 978-1-880653-81-4; ISSN 1098-6189

www.isope.org

Tolerance optimization for high temperature triple eccentric butterfly valve using QRNN algorithm
Zhuyun Shao , Bowen Jin , Ji Zeng , Renan Liu , Pan Gao , He Zhang , Shukang Tong
Shanghai Maritime University, Shanghai AFFCO Flow Control Co., Ltd.
Shanghai, China

ABSTRACT

structure and valve disc for numerical solution, such as genetic
algorithm (Ding et al., 2009 , Jiao and Li, 2013 , Zhang et al., 2011).
The references of (Corbera et al., 2016) performed multi-objective
global optimization butterfly valves and verified the reliability of theresults by comparing actual data. A game theoretic approach to design
tolerance to reduce manufacturing cost and optimal installation is by(Lu et al., 2012). Variation in torque was obtained in the references(Zhe et al., 2020) due to the different pressure on both sides of thevalve disc by computational fluid dynamics (CFD), and the torquefluctuation intensity became larger when the stem diameter was smaller.
In references of (Chen and Fan, 2011) only established the 3D model oftritec butterfly valve and the simulation movement of switching, but did
not carry out correlation analysis.
At present, there has not been research on the interaction between
bearing tolerancing and jamming of tritec butterfly valves thatincorporates non-linear thermal expansion of the valve materials at hightemperature. In particular, the design of tolerances is generally
calculated through simple empirical formulas combined withexperiments, which is uneconomical and time-consuming. There is noconvenient guide formula for bearing tolerances, and there is notolerance optimization of tritec butterfly valve.
In this paper, the research object is the tritec butterfly valve with923.15 k steam and four inches used in the marine platform. COMSOL
is used to establish 3D model and the friction torque is calculated bymultiplying the contact stress by the diameter of the valve stem,
through parameter scanning to obtain the dynamic tolerance diagram ofthe bearing. After that, the QRNN algorithm is used for multi-objective
optimization to find out the optimal tolerance, so as to obtain thetolerance to satisfy the minimum objective under the constraint
condition. Namely, the optimal tolerance should minimize thedimension chain and cost without jam.

Thermal expansion of materials at high temperature exhibits anonlinear change with temperature. Therefore, it is difficult to design
the tolerances of the shaft and bearing, bearing and body, valve discand metal seat of traditional marine triple eccentric butterfly valves andsimilar nested structures, which can jam or leak. Tolerances are
generally calculated through simple empirical formulas combined withexperiments, which is uneconomical and time-consuming. COMSOL isused to analyze the contact stress and friction torque corresponding todifferent tolerances when each nested structure is subjected to thermalexpansion and structural coupling at different temperatures, to obtain
the optimal tolerance. Quantile Regression Neural Network (QRNN) is
used to analyze the optimal tolerances, which can meet the friction
torque based on the minimization of the dimension chain without jam.
The optimal tolerances are sorted into a dynamic tolerance diagram ofthe bearing, forming an efficient design methodology. Results from ahigh temperature switching test of 1000 tolerances under different
working conditions demonstrate that the tolerances obtained by thismethod are reliable.

KEY WORDS: triple eccentric butterfly valve; thermal expansion;
jam; QRNN algorithm

INTRODUCTION
The triple eccentric (tritec) butterfly valves can realize flow regulationand fluid truncation at high temperature (up to 973.15 k), which is
widely applied in offshore platforms and ships for high temperature
steam transmission. The particular structure of the tritec butterfly valve
reduces the friction drag of the valve disc and the valve seat. The
second is that the pressure becomes tighter and tighter when the valve
is closed, so as to achieve reliable sealing requirements. However, thisis also the difficulty and key point of design and manufacture, and thereason that friction torque of each part are cannot be accuratelycalculated. Bearing is a vital structure, and its tolerance optimization
design includes the establishment and solution of tolerance
optimization model. However, the existing tolerance optimization
model mostly considers the dimension chain and price of sealing

THEORETICAL STUDY ON JAM
Causes of Jam
In references of (Li et al., 2018) stated three eccentricity of tritec
butterfly valve refers to axis eccentricity and radial eccentricity ofvalve body center and angle eccentricity between butterfly disc axis

863