Vortex flowmeters operate by measuring pressure variations associated with vortices shed from a ‘bluff body’ in the flowline. Traditional devices use piezoelectric sensors which require associated electronics, so limiting their application in harsh and hazardous environments. SmartFlow addresses this limitation by combining vortex shedding flow measurement techniques with FBG sensing advantages. The result is a meter capable of withstanding extremes of temperature, vibration, magnetic field and radiation, whilst operating in hazardous areas without expensive associated Ex rated electronics. This then enables more affordable and practical flow measurement in such applications as steam plants, subsea and downhole oil & gas, LNG flowlines and nuclear reactors.

SmartFlow was tested in dry gas at pressures between 1 and 40 bar, showing linear performance at various pressures and demonstrating good accuracy across a range of Reynolds numbers. The meter was also tested in wet gas at up to 30% mass fraction of liquid, achieving accuracies better than 10% for wet gas.

A further, unique SmartFlow feature comes from the FBG data processing scheme. For conventional, electronic-based vortex flowmeters, sensor data is typically encoded into a simple 4-20mA signal at the point of measurement, at which point all further, detailed measurement data is lost. For SmartFlow, high-frequency signals from the FBG sensors are transferred to the remote instrument and fully analysed for data content. This data was found to contain a signal representing the Eigenfrequency of the sensor plate that correlates directly with the density of the flowing fluid. For steam flow applications, this leads to the highly sought after capability of combined steam flow and steam quality measurement from a single, inexpensive meter.

The multiplexing capability of FBG technology allows for a system wherein dozens of SmartFlow meters across a facility can be simultaneously interrogated with a single SmartScan interrogator, ATEX certified as required. For use in a surface facility, the interrogator can be located in a safe area control room. For downhole or subsea use, the interrogator can be located in a suitable surface location some tens of kilometres distant from the point of measurement.

  • FBG vortex shedding flowmeter suitable for liquids and gases
  • Also measures density from which steam quality and thermal mass flow is derived
  • No electronics enables ultra-harsh environment use
  • Intrinsically safe operation with ATEX certified SmartScan interrogator
  • Numerous meters can multiplex to a single, remote instrument
  • Surface, subsea or downhole application
  • Designs available for 1” to 12” lines
Case Study 2013

Case Study 2013. Steam flowmeter development and qualification

Related FAQs

FAQ. What is the warranty period for Smart Fibres equipment?

All of our fibre optic sensors come with a standard one year warranty. This warranty can be increased on a year by year basis. Extended warranty is available at the time of initial purchase on request.

FAQ. How do I calculate which wavelength to use for my FBGs to maximise the number of sensors on a particular channel?

Smart Fibres has created a wavelength budget calculation tool for FBG wavelength selection.

Please Email Us or call +44 1344 484111 with details of your application and we can help you create a wavelength budget.

FAQ. What fibre type is used in your systems?

Single mode fibre with a 9 µm core, 125 µm cladding, and a 155 µm Polyimide or 245 µm Acrylate coating. Optical Fibers with pure silica core, bend tolerant and small core e.g. 6/125 or 4/125, can also be used but with some optical power losses. Multi mode fibre cannot be used.

FAQ. Can we put different sensor types on the same fibre?

Yes, Smart Fibres’ WDM products allow the user to combine different sensors types, e.g. temperature, strain and vibration all on a single fibre.