A suite of High Rate Heavy Vacuum Gas Oil (HVGO) pumps in an operating Upgrader Plant experienced repeated failures; typically, less than 7 weeks. The need for online measuring tools arose that could measure pump and piping system strain changes with dynamic thermal gradients. The challenge was to record the effect on the entirety of pump component alignment and vibration. In current industrial practices no such tools and techniques are directly and comprehensively available for rotary equipment. Strain gauges are not accurate, and cannot provide broader real time strain mapping.
Optical metrology can analyze the mechanical properties and behavior of all kinds of materials in various test scenarios. To date such methods are experimental and principally found in advanced application environments. At the time the method was unknown and especially in such a difficult industrial plant. In such a complex and extreme hot and cold operating service warm-up, cooling, with variations in flow and temperature, can directly and dynamically affect strain measurements.
It was not certain whether optical meorology measurement techniques would be able to identify and correlate dynamic operating scenarios with the source of the pump and pipe hardware issues experienced in these Heavy Vacuum Gas Oil (HVGO) pump systems.
The influence of the casing thickness and stiffness on the resulting vibration characteristics was investigated by using FEA and operational testing and dynamic analysis. Increasing the interface web thickness results in notable reduction in deformation. Comparison of the results of the live testing against the initial design was performed and studied for remedial action. Materials and heat treatment options were also evaluated and reported. The three-dimensional turbulent flow was modelled and analyzed.
The application of those tools for this type of problem are described along with the other rigorous techniques employed. The range of tools included modal and vibration analysis, thermography, rotor and shaft dynamics, baseplate, frame, metallurgical analysis and ultimately compared with FEA, pipe stress modelling and strain analysis.
This paper should be read in conjunction with PVP 2020-21204; Piping & Equipment Dynamics of High Rate HVGO Pumps.