World Bunkering >Articles > Company profiles > Endress + Hauser

Introduction

In the past few years, more and more attention has been given to the measuring of bunker fuel quantities. This has driven the industry to develop new improvements to the traditional manual tape measurement of tank levels.

Because of its inherent advantages over level based volume systems, the attention has been focused on the principle of Corioliseffect direct mass measurement. Coriolis meters are already widely recognised for their outstanding performance and unbeatable high reliability and availability. They are now used as the principle of choice for all industries and throughout the world – both for process control and for custody transfer applications in single-phase flow.

As a manufacturer of Coriolis Flow Meters and complete metering packages, Endress + Hauser have developed a total solution based on valuable inputs from the stakeholders in the whole process of bunkering. Endress + Hauser draws on its large experience of custody transfer applications in the traditional oil industry. Furthermore, Endress + Hauser are a member of the Committee led by the Marine Port Authorities in Singapore, where all stakeholders are working on a common standard for bunker metering.

The principle of Coriolis

In Coriolis meters, a meter tube is brought into oscillation with angular velocity ω (omega). The combination of this oscillation and the movement of the fluid through the pipe lead to an additional force on the measuring tube, the so-called Coriolis force. Let us have a look at the inlet piping section at the moment when the pipe moves to the top:

• The mass particle has an oscillation velocity v1
• The mass must then be accelerated to a higher oscillation velocity v2 (in order to move with the same angular velocity ω)
• Because the mass particle is inert, it presses against the pipe wall when being accelerated
• The pressure against the pipe wall points downwards and therefore slows the pipe movement down.

Now let us look at the outlet piping section:

• The mass particle has an oscillation velocity v1
• It has to slow down to a lower oscillation velocity v2 (in order to move with same angular velocity ω)
• Because the mass particle is inert, it presses against the pipe wall when being decelerated
• The pressure against the pipe wall points upwards and therefore the pipe movement is accelerated.

If the oscillation of the measuring tube(s) is picked-up at the inlet and the outlet, the signals will be in phase as long as there is NO mass flow. The increasing mass flow will generate a proportional Coriolis force, which in fact will influence the oscillation due to either dampening or acceleration of the tube motion. The two signals will show an increasing phase shift that is proportional to the mass flow.

A very clear video animation and explanation of the principle of Coriolis mass flow meters, can be found on www.endress.com or on YouTube (Search Coriolis + Endress).

Experiences so far

The first mass flow meter from Endress + Hauser for bunkering use was installed on Star Cruises, Super Star Virgo in Singapore in 2007. The first test gave a clear picture of the complexity of solving this special flow application. Due to the amount of air entrained during start up, ‘tank stripping’ and even normal operation, the first meter readings of this two-phase flow were not as impressive as expected. There are several possible solutions to this problem, but following discussions with the ship’s Chief Engineer, in this application a large capacity air eliminator was installed before the meter in order to create the best possible measuring conditions.

This amendment completely solved the problem, and the Super Star Virgo successfully meters its fuel bunkering every Friday in Singapore port.

Testimonial from Star Cruises

“During our weekly bunkering, the metering system performance (accuracy and repeatability) has been beyond our expectations. It helps us to achieve better efficiency and avoid any more disputes with our bunker suppliers. We are today very satisfied with the decision we took to engage Endress + Hauser as our partner in this project. We would recommend anyone looking for correct bunker figures to approach Endress + Hauser for installation of a bunker mass flow meter.”

Chief Engineer Kenneth Olsson

On the cruise ship Super Star Virgo, the space in the engine room presented the opportunity to install the large capacity air eliminator – this may not be possible for all similar installations. Therefore Endress + Hauser have developed a system that is able to operate without installation of an air eliminator. The philosophy and success of the system is based on two key factors:

Initial calibration is essential to any metering application. Endress + Hauser have invested a significant amount in facilities and skill in this area and are considered by many to be leaders in this field. When it comes to the flow metering of high viscosity fluids such as HFO, published research shows that to achieve acceptable accuracy the Coriolis meter should be calibrated on a fluid similar to that which the meter is intended for, as requested by OIML. Furthermore it has been proven that the adjustment needed is individually depending on the single meter under calibration. Endress + Hauser perform these calibrations at a purpose built internationally approved facility near Marseille, France, on multiple oil grades.

Secondly, to improve the metering conditions and hold single phase flow conditions for as long as possible during the bunker process, a pressure maintaining valve may be installed downstream of the meter.

In the periods where this is not possible (eg during tank-stripping and ‘ramp-up’ of the pumps) algorithms in a supervisory computer calculate the quantity of oil passing through the meter based on various diagnostic meter parameters. For best overall performance, these periods should be kept to a minimum. The Coriolis meter acts as a very sensitive sensor, with an ability to monitor itself for entrained air. If this is the case, the system will raise an alarm so that the proper measures can be taken to resolve the issue.

After bunkering completion, the system delivers a ‘Bunker Verification Report’ similar to the manual Bunker Reports used today. An additional advantage of this system is that it is possible to see all data collected during the bunker process in order to easily visualise any abnormalities.

This gives all involved parties access to a full historical data log of events, in the case of disputes.

Since all data from a bunkering are available in data format it is possible to transfer this electronically to any ERP system – for example this could allow immediate invoicing of the customer. It also offers barge owners improved opportunities for logistic optimisation since they can now monitor real-time online quantities delivered/ received from all barges.

In 2009 Maersk Oil Trading purchased 10 systems from Endress + Hauser which are currently under installation and test. The first test results are currently being evaluated but indicate that the system will meet the challenges with minor mechanical changes in the installations.

Endress + Hauser company profile

Endress + Hauser is a global leader in measurement instrumentation, services and solutions for industrial process engineering. With over 8,400 employees worldwide, the Group generates annual net sales of more than E1.2 billion.

Company-owned sales centres and a network of partners guarantee competent worldwide support. Production centres in 11 countries meet customers’ needs and requirements quickly and effectively. As a successful family-owned business, Endress + Hauser is set for continued independence and self-reliance in the future.

Endress + Hauser provides sensors, instruments, systems and services for level, flow, pressure and temperature measurement as well as liquid analysis and data acquisition. The company supports customers with solutions and services in automation engineering, logistics and information technology. Our products set standards in quality and technology.

Customers are primarily from the chemical/petrochemical, food & beverage, water/wastewater, life science, oil & gas, power & energy, renewable energies, primaries & metal, pulp & paper and shipbuilding industries. Endress + Hauser supports its customers to optimise their process engineering procedures while taking into consideration reliability, safety, economic efficiency and environmental protection.

Founded in 1953 by Georg H Endress (1924-2008) and Ludwig Hauser (1895-1975), Endress + Hauser have been solely owned by the Endress family since 1975. The company group, headed by Klaus Endress since 1995, has developed from being a specialist in level measurement to a provider of complete solutions for industrial measuring technology and automation, with constant expansion into new territories and markets.

For further information, please contact
Jens Fuglsang
Industry Manager Oil & Gas/Marine
Tel: +45 24 46 90 22
E-mail: jens.fuglsang@dk.endress.com
Website: www.dk.endress.com