Reliable flow measurements on the high seas

In order to transmit electricity from the sea to land, it must first be converted from alternating current to direct current on large offshore converter platforms. To ensure that this complex technology functions flawlessly, a wide range of technical parameters must be monitored. Contactless measurement systems, which can be used without interrupting the process, are the perfect tool for this.

Offshore work environments are characterised by confined spaces, harsh environmental conditions, and also by the individual mental and physical agility of their staff. A consistently high work pace characterises the day-to-day working life of offshore teams. This places corresponding demands on the robustness and ease of use of the measurement technology employed. A wide range of regulations and provisions ensure that only suitable measuring equipment may be used to fulfil these demanding measurement tasks. This is where the tried-and-tested, non-contact ultrasonic flow measurement technology, with its clamp-on sensors, comes into its own, allowing the user – without the need for time-consuming process interruptions or interventions in the process system – to install or relocate the equipment easily, and to generate accurate and reliable data on flow velocity, volumetric flow rate and thermal energy.

Owing to these characteristics, TenneT TSO GmbH – a transmission system operator with a statutory obligation to connect offshore wind farms to the grid – set out to find a suitable measuring instrument. The aim was to find a portable ultrasonic flow meter that met all criteria regarding compactness, robustness and intuitive operation. Other measurement methods were not considered due to the requirement for a non-invasive measurement method. The measurement equipment was deployed on the offshore converter platforms HelWin alpha and beta, as well as SylWin alpha, in the eastern North Sea.

Following a recommendation, attention quickly turned to the international measurement equipment manufacturer Katronic AG & Co. KG. After in-depth consultation, a trial run with a KATflow 200 portable ultrasonic flow meter was agreed and carried out. Olaf Koberstein, Deputy Service Group Manager at TenneT TSO GmbH, commented: “I was particularly impressed by the intuitive operation, the professional support and, of course, the excellent measurement results.” At the same time, the Acoustic Sensor Positioning Assistant – a user aid for precise sensor placement – was particularly highlighted. This meant that nothing stood in the way of purchasing the measuring equipment.

Today, the flow meter is primarily used to monitor pumps, measuring sensors and various control valves. The meter is also used to regularly check the helideck’s water-based fire-suppression system. This enables potential faults in the system to be identified quickly and ensures the proper operation of the entire system. The measurements primarily involve salt water, fresh water and water-glycol mixtures in various concentrations, within a pipe diameter range of DN 25 mm to 450 mm.

Across a wide range of industrial sectors, it has become increasingly clear over the years that flow measurement technology based on ultrasonic technology has, thanks to its versatility, established a firm place in the range of applications used by many engineers and technicians, and is demonstrating its far-reaching advantages in ever-new market segments.

Image credit: TenneT