Application note

Sentinel in LNG terminal offloading application
Benefits:• Low maintenance• No pressure drop = reduce
flashing risk
• No Interruption to operations
after installation• Long term stability and drift
characteristics

Summary
Natural Gas is one of the most in-demand energy sources of the century as we
look for more sustainable energy sources. As the energy transition rapidly gathers
momentum, the demand for natural gas will continue to increase. To manage thegrowing demand, construction of LNG receiving terminals are also increasing. As ofFeb-2021, global LNG regasification capacity reached a high of 850.1 MTPA; and isstill growing (source: World LNG report 2021).
Keep reading to learn how Panametrics measurement technology was used at theQingdao, Tianjin LNG terminal in China to help optimize the conversion of LNG toNatural Gas.

Application
The main LNG component is methane; ranging between 75% and 99% content.
Regasification terminals harbor ships carrying LNG which need to be unloaded intostorage tanks, before being converted into Natural Gas and connected to the grid.
Offloading the LNG is a critical step. It must be measured accurately to comparewith what has been recorded from the vessel tank gauges. If the two sets of data
do not marry up to an acceptable level, then the operator may raise questions andchallenge the vessel owner or their supplier, even if the billing is typically always
coming from the vessel. There are various potential technologies to measure LNG
flow, including Venturi, Coriolis and ultrasonic flow meters.

Challenges
For these offloading applications, Coriolis mass flowmeters are usually unsuitable
due to very high flow capacity - the pipe size is typically > 24” and in the Qingdao
example 42” (DN1050). During the offloading process the LNG flows at low pressure,therefore it is critical that any risk of local flashing is prevented, particularly given
LNG’s close proximity to its vapor pressure point. Knowing that local flashing causes
serious issues, especially as the volume ratio of gas is 600 times that of liquid, carefulmeasurement technology selection is required. This would rule out Venturi type
differential pressure flow meters.

Although they exhibit the lowest pressure drop among thedifferential pressure technologies, the Venturi technology isstill susceptible to drops in pressure and are expensive forsuch large line sizes. In this case an ultrasonic transit time
flowmeter was the most effective choice.

Solution
At the China Qingdao, Tianjin LNG terminal the customer
selected Panametrics 4-path Sentinel LNG flowmeter asa fit for purpose solution. The customer recognized thelevel of accuracy and reliability that the technology offers,
developed after more than 20 years at the forefront of theultrasonic measurement sector for LNG.
The Sentinel LNG uses a BWT (Bundle Waveguide Technology)transducer with feed thru buffers to create a temperature
gradient that doesn’t expose the transducers to cryogenic
temperatures while also allowing online retraction underflowing conditions.
Computational Fluid Dynamics (CFD) analysis was used tosimulate different path configurations under various flowing
conditions enabling Panametrics to optimize its configuration
while also ensuring good accuracy under cryogenic conditions.

ResultThe customer can now confidently offload the LNG vessels
while ensuring the volume transferred to the terminal
measured by the flow meter matches the calculated volume
from the vessel tank gauges.
Panametrics Sentinel LNG was also successfully testedon the Rotterdam LNG accredited laboratory to assess its
performances under real life conditions.

Application specification
Qingdao LNG Terminal application data
• Pipe diameter: 42’’ 150# RF• Material: SS304/SS304L• Process pressure: 0.6Mpa (87 psi)
• Process temperature: -160 °C (-256 °F)• Flow range: 5,880 - 67,280 t/hr
• Flow velocity: 0.46~5.49 m/s (1.5~18 ft/s)
Panametrics, a Baker Hughes business, provides solutions in the toughest
applications and environments for moisture, oxygen, liquid and gas flow
measurement.
Experts in flare management, Panametrics technology also reduces flareemissions and optimizes performance.
With a reach that extends across the globe, Panametrics’ criticalmeasurement solutions and flare emissions management are enablingcustomers to drive efficiency and achieve carbon reduction targets acrosscritical industries including: Oil & Gas; Energy; Healthcare; Water andWastewater; Chemical Processing; Food & Beverage and many others.
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BHCS39136		

(09/2021)

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