Custody transfer system for LNG carriers

Transcription

1 Custody transfer system for LNG carriers

2 Reliable tank gauging for LNG carriers Thousands of tons of liquefied natural gas rush through the pipes into the tanks of your LNG carrier. Raising your eyes, you look beyond the dazzling lights of the tank terminal into the dark sand dunes behind. Concentrating on the levels, temperatures and pressures in the tanks, you feel confident that the Saab TankRadar system is giving you instant, accurate, reliable information about your cargo. This brochure tells you how your LNG carrier operation can become more efficient and profitable with the Saab TankRadar custody transfer system. 2

3 3 The Saab TankRadar custody transfer system can be installed on LNG carriers with either spherical or membrane type tanks.

4 4 All values from the Saab TankRadar system are available on the Work Stations. The Work Stations are based on PCs with a fast real time operating system. The system is operated using a light pen.

5 In control of your cargo The feeling of being in control and of being able to rely on your equipment is important to all professionals in tanker operations. But, when your job is to handle liquefied natural gas in a safe, efficient way, this becomes significantly important. With the Saab TankRadar custody transfer system for LNG carriers, you have reliable information so that you can safely control your cargo operation. No downtime due to repairs inside the tanks With Saab TankRadar we introduce a whole new way of measuring the cargo in LNG carriers. With the tank gauges on top of the tanks, there are no parts inside the tanks that can break down or degrade. Knowing how much unscheduled downtime costs, your Saab TankRadar system will soon pay off with its reliable operation. Accurate and reliable radar measurement We have put a lot of effort into making a tank gauge that measures with high accuracy even under the most demanding circumstances. You receive accurate, reliable figures during all stages of loading, transporting or discharging. The temperature and pressure sensors are connected to the radar tank gauges, so that the Saab TankRadar system always gives you the complete picture of the cargo in your LNG tanks. 5

6 Certified custody transfer system The costs of transporting gas and the cost of the cargo places a lot of importance on the custody transfer system on any LNG carrier. The custody transfer system must generate detailed and indisputable cargo reports, based on accurate measurements and calculations. Saab TankRadar is a complete custody transfer system for LNG carriers. Accuracy certified by NKKK NKKK, the Japanese sworn surveyor, has certified the Saab TankRadar system for custody transfer. Saab TankRadar s accuracy of ± 5 mm meets the requirement of LNG exporters and importers. And all the major classification societies have type approved the Saab TankRadar system. Verification at any time The Saab TankRadar gauge measures ullage, temperature and pressure. From these values the Work Station calculates for example, levels, vapor and liquid average temperatures and cargo volumes at average liquid temperature. It uses certified tank tables and corrects for parameters, such as thermal expansion of the tank and the still pipe, the propagation speed of the radar waves in the vapor space, trim and heel. Whenever company procedures or measurement standards require verification, the crew can easily verify the performance of any of the Saab TankRadar gauges. They just set it to measure the distance to a verification pin inside the still pipe. This pin is invisible to the tank gauge in normal operation. Furthermore, the performance of the Saab TankRadar gauges can be checked against verifiers set to correspond to 20% and 80% of the tank s level. 6

7 Detailed and indisputable cargo reports are generated 7 by the Saab TankRadar custody transfer system.

8 Radar is the natural choice for LNG carriers In a tank that is -160 C, and may not be opened for years, you really do not want to have electrical cabling or moving mechanical parts. Any failure on such equipment inside the tank might result in having to warm the tank, inert it, gasfree it, enter into it to repair the failed equipment, inert, purge and cool down the tank. No LNG carrier operator wants to do these time-consuming tasks. This is where radar tank gauging, with only the still pipe and the cone antenna inside the tank, comes into the picture. No equipment inside the tank can break down or degrade in operation. The safety risk involved when gasfreeing is eliminated and no harmful gases have to be released to the environment. The electronic box of the Saab TankRadar gauge is placed outside the tank. In the unlikely event of a failure, the crew can easily replace it with a certified spare. The tank gauge can be serviced, tested and back in operation in less than an hour. Because the temperature sensors are placed in a thermowell, they can easily be replaced from outside the tank. Spare temperature sensors are stored onboard in the spare parts set. The still pipe guides the radar waves The electronic box generates and transmits radar waves into the cone antenna. It provides a smooth transition for the waves into the still pipe. Because the still pipe guides the radar waves, very little signal energy is lost, which results in a strong echo from the liquid surface. Saab TankRadar means no maintenance No maintenance is required on the Saab TankRadar system. This means years of trouble free operation, with highly accurate and reliable results calculated and presented on the Work Stations. 8

9 9 The Saab TankRadar gauges are installed on top of your tanks. No equipment inside the tank can break down or degrade in operation.

10 Pressure seal Electronic box Ball valve Pressure sensor Protective hose Antenna cone Thermowell Temperature sensor Still pipe 10

11 11 The Saab TankRadar gauge is installed on top of a still pipe. The temperature sensors are installed in a thermowell. This means that you can easily replace the electronic box and the temperature sensors, with the tank in operation.

12 Convenient installation Because the only parts inside the tank are the still pipe, cone antenna and thermowell, the installation of the Saab TankRadar system is very convenient. It can be installed on newbuildings or be retrofitted on existing LNG carriers. Reduced testing at shipyard We put each Saab TankRadar system and each tank gauge, including the still pipe, through a factory acceptance test, that is also supervised by a sworn surveyor, before delivery. This minimizes testing at the shipyard and ensures the best possible measurement conditions. We deliver the still pipe in typically sixmeter-long, numbered sections, ready to be installed into the tank s pipe tower or tripod. The temperature sensors are installed into a thermowell manufactured by the shipyard. After the sensors have been installed and connected, the thermowell is inerted. Both the still pipe and the thermowell can share the same penetration through the tank dome. Technical support from design to commissioning Saab Marine Electronics supports the shipyard with documentation and technical support from the design stages to the commissioning of the system. Together with each Saab TankRadar system, we also provide comprehensive and dedicated documentation that includes all applicable certificates. One of our certified service engineers assists during the commissioning of the system. 12

13 Electronic box Protective hose for cables Antenna cone Still pipe Tank dome penetration Thermowell Temperature sensors Pipe for inerting the thermowell Pressure equalization hole Verification pin The Saab TankRadar system can be installed on newbuildings or retrofitted on existing LNG carriers. 13 Both the still pipe and the thermowell can normally share the same tank penetration.

14 Saab TankRadar Wed Aug 24 20:05: Window Overview Setup Group Trend Alarm Alarm P P P P CT4 Ullage m 0.00 m/h LC8 T=19.1 T=18.7 T=18.6 T.avg 18.8 C LC7 26 bar Cargo System Fore CT3 Ullage m 0.00 m/h LC6 T=19.1 T=18.7 T=18.6 T.avg 18.8 C LC5 24 bar CT2 Ullage m 0.00 m/h LC4 T=19.1 T=18.7 T=18.6 T.avg 18.8 C LC3 20 bar Help Exit all Back Exit CT1 Ullage m 0.00 m/h LC2 T=19.1 T=18.7 T=18.6 T.avg 18.8 C LC1 23 bar Saab TankRadar Wed Aug 24 20:05: Window Overview Setup Group Trend Alarm Alarm P P P P CT4 Ullage m 0.00 m/h LC8 T=19.1 T=18.7 T=18.6 T.avg 18.8 C LC7 26 bar Cargo System Fore CT3 Ullage m 0.00 m/h LC6 T=19.1 T=18.7 T=18.6 T.avg 18.8 C LC5 24 bar CT2 Ullage m 0.00 m/h LC4 T=19.1 T=18.7 T=18.6 T.avg 18.8 C LC3 20 bar Help Exit all Back Exit CT1 Ullage m 0.00 m/h LC2 T=19.1 T=18.7 T=18.6 T.avg 18.8 C LC1 23 bar OK i LCP LCMLCSLCMLCS LCI ALARM SYSTEM MENU SERV ENTER CLEAR Technical details The main parts of the Saab TankRadar system are: The tank gauges that measure ullage, vapor pressure as well as liquid and vapor temperature. The Level Unit that contains much of the calculation power for the signal processing and the circuits for ensuring the intrinsic safety. The tank gauges are connected to the Level Unit. The signal processors and memory circuits are doubled for internal redundancy in the Level Unit. The Work Stations that calculate the cargo volume from tank parameters and measured values. They also supervise and warn of any alarms that may occur. A Work Station consists of a PC that is type approved for operating in the marine environment. A printer is included for printing custody transfer reports and various logs. The Redundancy Box that automatically switches master Work Station, if the active master fails. Work Station Work Station Level Unit Hi.Hi CT 6 Ullage 1,837 (2,000) m 2...more Accept BuzzerStop Printer Hi.Hi CT 6 Ullage 1,837 (2,000) m 2...more Accept BuzzerStop Radar Tank Gauge Redundancy Box Interface to other computers I/O Box Still pipe and thermowell Technical specifications for Saab TankRadar Accuracy: ±5 mm Measurement range: 0-45 m Gauge operating temperature: -40 to +80 C (intank temperatures can be down to -165 C) Max. operating pressure: 8 bar abs Intrinsic safety of gauge: EEx ia IIC T4 Temperature measurement range: -165 to +55 C Temperature measurement accuracy (including sensor): ±0.2 C for cargo temperatures -165 to -145 C, ±1.5 C for cargo temperatures -145 to +50 C Number of temperature sensors: Typically 5 active sensors per tank Pressure measurement range: 0.8 to 1.4 bar abs Pressure measurement accuracy: ±1% of full scale Still pipe (Saab or yard supply): x 3.65 mm in stainless steel or aluminum Thermowell (yard supply): Max. outer Ø 32 mm Tank penetration (yard supply): Still pipe only: Min. inner Ø 154 mm, recommended 250 mm Pipe and thermowell: Min. inner Ø 300 mm 14

15 Saab Marine Electronics Pioneers in radar tank gauging Tank gauging with radar is not a new technology for Saab Marine Electronics. We have developed, produced and marketed radar tank gauging systems for tankers since We have released three generations of Saab TankRadar systems for tankers each new generation bringing new customer benefits. Today, more than tankers are sailing with Saab TankRadar systems. onshore tanks are equipped with Saab TankRadar and it has been successfully installed on LNG storage tanks in Japan. More than Saab TankRadar gauges have been installed on both tankers and onshore tanks. Certified quality and environmental systems Copyright Saab Marine Electronics AB, May Contents subject to change without prior notice. Saab TankRadar is a registered trademark. In the early 1980s Saab Marine Electronics released Saab TankRadar for onshore In 1992, Saab Marine Electronics was the first supplier of tank gauging equipment tanks. Many of the same features that to be certified according to ISO In brought success on the tanker market, 1997 we were again first to be certified appealed to the instrument engineers at according to ISO for our environmental management system. refineries, tank terminals, chemical plants and other industries. More than 500 LPG LNG/C Khannur with Saab TankRadar onboard. 15

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