Orifice Plate Deformation

Completed

Fossil Fuels: Oil Gas and Coal(Oil and Gas, Refining, transport and storage of oil and gas)

Applied Research and Development

PHYSICAL SCIENCES AND MATHEMATICS (Physics)
ENGINEERING AND TECHNOLOGY (Mechanical, Aeronautical and Manufacturing Engineering)

Not Cross-cutting

Project Contact
Cadent Gas

Network Innovation Allowance

Ofgem

01 February 2011

01 May 2014

39 months

£190,154

Technical Consultancy

London

Network Innovation Allowance

Project Contact, Cadent Gas

Project Contact, National Grid Gas Transmission
Project Contact, Northern Gas Networks
Project Contact, SGN

To improve the measurement of volume and energy flow through orifice plate metering systems by ensuring that orifice plate deformation is calculated correctly. The achievements of this project will enable the calculation of orifice plate deformation to be carried out more accurately, there is currently not a single agreed industry method and with the advantages of modern computational techniques, it is believed that this can now be achieved; The ultimate aim is to recommend this method as the Industry Standard. The technical achievements are anticipated to be: -Survey of existing technical literature to establish current status of orifice plate deformation calculation. Establish the causes of the differences between the Jeplast routine within HPMIS and other equationsUse computational fluid dynamics (CFD) to calculate the actual load distribution on the orifice plate for a worst possible case. Use FEA to calculate the behaviour of the orifice plate under the load distribution calculated from the CFD for a worst possible case. Repeat the CFD and FEA calculation method established in stage 2 for a range of plate sizes, beta ratios, seal and mounting types. Recommend a method of calculating orifice plate deformation that can be implemented.

There is a need for an agreed industry method of calculating orifice plate deformation more accurately. Equations currently used to calculate orifice plate deformation were derived during the 1920’s to 1950’s, some work was also undertaken by the British Gas Engineering Research Station in 1975, the results of which are included in a program called Jeplast which is embedded in HPMIS, it has been noted that there are differences in the results obtained from Jetplast and other equations which are noticeable at higher beta ratios currently and commonly in use in the UK, further differences have also been noted when comparing results obtained from Jetplast and those independent auditors, this has impacted the compliance with the ISO standard. An initial study has been carried out and comprised a survey of the existing orifice plates in use by National Grid Distribution as well as the existing technical literature and equations currently used to predict orifice plate deformation. Further stages of the project will involve computational fluid dynamics (CFD) and finite element analysis (FEA) to establish how orifice plates behave in the field, to determine and quantify measurement errors caused by the deflection of orifice plate. CFD runs have to be conducted with the deflected orifice plate geometry which is unknown at the start. For this, iterative runs between CFD and FEA are required, this will establish the parameters and geometries which have the greatest effect on orifice plate deformation, the output from this stage will be a new method for assessing orifice plate deformation based on the worst possible case - this will enable the identification of those parameters which have the greatest impact.Note : Project Documents may be available via the ENA Smarter Networks Portal using the Website link above

17/09/18