(577d) Effect of Friction Factor Correlations and Propagation Errors on Differential Pressure in a Crude OIL Fouling Measuring RIG

EFFECT OF
FRICTION FACTOR CORRELATIONS AND PROPAGATION ERRORS ON DIFFERENTIAL PRESSURE IN
A CRUDE OIL FOULING MEASURING RIG

Z.
Tajudin⁺, E.Diaz-Bejarano⁺, F. Coletti*, S. Macchietto⁺*
and G. F. Hewitt⁺*

+Department of Chemical Engineering, Imperial College London, South
Kensington Campus, London SW7 2AZ, UK

* Hexxcell Ltd, Imperial College Incubator, Bessemer Building Level 2,
Imperial College London, London SW7 2AZ, UK

Corresponding
author: s.macchietto@imperial.ac.uk

Keywords:
pilot scale, error of propagations,
experiment, validation

Abstract

In order to detect crude oil fouling
experimentally, primary measurements of 
differential pressure and temperatures must be obtained with high
fidelity, accuracy and reproducibility at (or close to) industrial conditions. Information
of the thermal and hydraulic effects of fouling can be studied by using robust
models to decouple the various phenomena involved. To start with, it is
important to have a reliable set of primary measurements in which the robust
model could be validated against the experiment data.

A novel pilot scale experimental
facility for study of crude oil fouling, 
High Pressure Oil Rig (HIPOR), was developed and tested with non-fouling
oil and crude oil at different operating conditions. The experiments have been
carefully designed in order to develop comprehensive and reliable baseline
validation for both oils without any fouling deposition. The model, an
extension of Hexxcell's model for HiPOR, for the tubular test section with
vertical geometries, considers the two dimensional (axial and radial) heat
transfer in different domains, boundary conditions and other aspects (for
example, heat losses) which are carefully determined.

The objectives of this work are
divided into two. First, a predictive model for differential pressure of the
HIPOR test section is validated against experimental results for both oils.  The model consists three friction factors
correlation was used to assist in the analysis and interpretation of the
experimental data collected, compared with 
the variation of flowrate as well as different heat inputs. Second, the
errors of propagation which are observed from the validation process have been
identified and its sensitivity towards inlet bulk temperature increments quantified.
 

The validation process shows that both
oils show excellent agreement with model predictions for at all ranges of
operating conditions and capturing all responses including the transient
processes. The best agreement is achieved for different friction factor
correlations for each oil. The reported results also show that the deviation
between simulation data and measured data due to the errors of propagation
starts to increase when the inlet bulk temperature of oil is increased from 80 ^oC
onwards. Furthermore, the errors of propagation have a linear correlation with
the temperature increment.

It is concluded that the model of the
HIPOR rig for non-fouling and crude oil conditions for differential pressure were
successfully validated and error of propagations with temperature effects have
been quantified. 

Acknowledgments

This research was
partially performed under the UNIHEAT project. The authors wish to acknowledge
the Skolkovo Foundation and BP for financial support. ZT wishes to also
acknowledge MARA and UniKL for their support and
funding. The support of Hexxcell
Ltd, through provision of Hexxcell Studio?, is also acknowledged.

References

S. Macchietto, G.F. Hewitt,F. Coletti, B.D. Crittenden,
D.R. Dugwell, A. Galindo, G. Jackson, R.
Kandiyoti, S.G. Kazarian, P.F.
Luckham, O.K. Matar, M. Millan-Agorio, E.A. Müller, W. Paterson, S.J. Pugh, S.M. Richardson, D.I. Wilson, ?Fouling in crude oil preheat
trains: a systematic solution to an old problem?, Heat Transfer Engineering, 32, 3, 197-215 (2011).

F. Coletti and S. Macchietto,
A dynamic, distributed model of shell-and-tube heat exchangers undergoing crude
oil fouling. Ind. Eng. Chem. Res. 50 (8), pp 4515?4533 (2011).

Z. Tajudin, Experiments,
Modelling and Validation of Crude Oil Fouling on Large Scale Rig. PhD, Imperial College London, UK ? submitted
for PhD awards (2015).

Hexxcell Ltd., 2015. Hexxcell Studio. http://www.hexxcell.com.