Kongsberg K-GAUGE GAS LNG / LPG / NH3 FUEL TANK MONITORING SYSTEM

The K-Gauge GAS LNG/LPG/NH3

fuel tank monitoring system is designed to meet the classification

rules and guidelines concerning instrumentation and monitoring

of storage tanks for ships using liquified gases as fuel.

The accuracy, reliability, integrity and safety of shipboard

containment and operations are key ele ments embedded into

the system design.

System description

The implementation of dual fuel engines and growing interest

in using liquefied gases as a marine fuel, raise many practical

challenges regarding bunkering, storing and processing.

The K-Gauge GAS fuel tank monitoring system is designed to

fulfil the requirements set in the IGF Code and the challenging

demands concerning safe monitoring and storage of liquefied

gas on board ships.

KONGSBERG extensive knowhow from 20 years in produc

tion, design and servicing LNG automation and tank monitoring

systems, is embedded into complete solutions for main engine

control, Fuel Gas Supply and tank instrumentation for monitor

ing of fuel tanks for liquefied gases (LNG / LPG / NH3).

Functional description

K-Gauge GAS fuel tank monitoring system measure the level

by use of KONGSBERG well proven Radar Tank Gauge.

Extensive surface movements, combined with the low dielec

tric properties of LNG and LPGs, require quality instrumenta

tion and signal processing to provide reliable measurements.

KONGSBERG unique Radar Tank Gauge design, with its high

signal-to-noise ratio and powerful signal processing, offers

accurate measurement regardless of the tank atmospheric con

ditions.

The system also implement quality temperature- and pressure

transmitters, safety barriers, processing units and display panel

for local monitoring through dedicated mimics.

Flexible hardware and software modules ensure easy adapta

tion to all IMO type tank designs, and all kind of liquefied gases.

All field equipment is designed and certified for marine use,

manufactured in AISI 316L stainless steel and type approved by

the major classification societies. The intrinsically safe appara

tus is certified Ex ia according to ATEX and IECEx.

BUILDING BLOCKS

Radar Tank Gauge (RTG)

The KONGSBERG Radar Tank Gauge (RTG), GLA-310/5

FUEL, is designed to measure level in tanks containing lique

fied gases. Accurate measurement is possible regardless of the

tank atmospheric conditions. Flexible hardware and software

modules ensure easy adaptation to all tank designs.

The RTG consists of a microwave antenna and an electronic

unit. The electronic unit includes a sophisticated signal detec

tion method that ensures optimum performance, which com

bined with its superb signal-to-noise ratio offers the highest

measurement reliability and accuracy.

The horn antenna is designed to guide a frequency sweeping

microwave signal through a 50 mm standpipe. The distance is

derived from the time delay of the reflected signal.

The standpipe has ventilation holes allowing the vapour pres

sure inside and outside the pipe to stabilize, thus allowing the

liquid to rise or fall in the pipe. The standpipe is considered an

integrated part of the level gauge, and is delivered to match the

total tank height.

The RTG is specially designed to withstand the severe mechan

ical and physical conditions in a maritime environment. Only

AISI 316L acid-resistant steel and PTFE/PEEK materials are

used.

Signal Processing Unit (SPU)

Each RTG is connected to a dedicated signal processing unit,

where the specific tank design data is stored.

The GLK-300 Signal Processing Unit (SPU) is located in safe

area and provides necessary communication and power barri

ers to the instrumentation located in hazardous area. The SPU

employs powerful processing of the data from the Radar Tank

Gauge and temperature transmitter.

AutroCAL®

Gas vapour density and mixture of gases influence the prop

agation speed of the radar signal, thus the accuracy of the

measurement. AutroCAL® utilizes multiple reference markers to

measure the speed of the signal down the tank and continuous

ly compensates level readings for a varying propagation speed.

Each pipe section is delivered with reference markers in the

flange joints. The liquid level and the markers are measured

simultaneously, and the system automatically verifies itself at

every measurement.

Temperature transmitter

The K-Gauge GAS system offers two alternative temperature

monitoring configurations:

Alt. 1: Up to three temperature sensors

KONGSBERG Cargo Temperature Unit (CTU), GC-300. is a

marine approved intrinsically safe signal converter and connec

tion box designed for installation on tank top for connection of

up to three temperature sensors through one tank penetration.

Alt. 2: Up to six temperature sensors

KONGSBERG Cargo Temperature Unit (CTU), GC-306. is a

marine approved intrinsically safe signal converter for con

nection of up to six temperature sensors. The transmitter is

designed to be installed in a local cabinet. A connection box for

connection of the temperature sensors on tank top is included

and provide gas sealing toward the tank atmosphere.