Passively-cooled Cabinets on World’s Largest Vessel

MarineLink.com
Thursday, February 20, 2014
Custom instrumentation protection cabinets that Intertec is producing for Shell’s Prelude FLNG project are designed to withstand Category 5 cyclones.

Enclosure specialist Intertec is supplying high performance environmental protection cabinets for Shell’s Prelude floating liquefied natural gas project. Designed specifically for extended service life in hazardous areas, the shelters incorporate innovative semi-passive cooling technology and are some of the most stringently specified instrumentation protection solutions that Intertec has ever produced.

Shell’s Prelude floating liquefied natural gas (FLNG) project is setting new engineering records. Designed to liquefy natural gas extracted from subsea wells by chilling it to -162 degrees Celsius, and to then store the liquid until it is offloaded to large LNG carriers, the vessel will be the largest in the world, with a length of 488 meters and a width of 74 meters. The hull of the vessel was constructed in South Korea and launched in December 2013. Due to enter service in 2017, the vessel will be towed to the Prelude and Concerto gas fields in the Browse Basin near Timor, about 200 km off the northwest coast of Australia, where it will be permanently anchored for about 25 years. After this time it will be inspected, overhauled and possibly moved to a new location, where it will be expected to provide a further 25 years of service.

Much of the on-line process analysis instrumentation on the Prelude FLNG vessel will be housed in purpose-built environmental protection cabinets supplied by Intertec. In total, the company is supplying 90 cabinets for sample conditioning systems and 30 cabinets for process analyzers, each designed to match the instrumentation content and layout precisely in order to optimize thermal performance.

As Intertec’s Commercial Director, Hans Geiger, points out, “Only three of the 120 cabinets that Intertec is supplying for this project are the same size. Our specialized design and automated manufacturing capabilities enable us to produce custom environmental protection products very easily, to optimize performance and match the space available on demanding applications like this.”

The cabinets that Intertec is supplying are required to be capable of withstanding severe Category 5 tropical cyclones with wind speeds in excess of 252 km/h (157 mph) and to have a minimum service life of 25 years - with 50 years as a design aim. Additional requirements include a high degree of resistance to corrosion being caused by the saline environment and the presence of sour or acid gas, and the ability to cool electronics equipment without using explosion-proof air conditioning systems, which incur high capital and operating costs.

Intertec’s environmental protection cabinets are constructed from a proprietary composite material comprising sandwich walls of long-fiber glass reinforced polyester (GRP) sheets, enclosing a core of polyurethane foam. The material has a similar strength to that of stainless steel but is about four times lighter, making it ideal for use on offshore platforms and floating structures, where every effort is made to minimize weight.

Other advantages include a very low thermal conductivity which facilitates the construction of efficient, condensation-free cooling cabinets, and an inherently high resistance to corrosion caused by salt or aggressive chemicals such as sulfur or chlorine. For this project, the external surfaces of the cabinets are further protected by a thick layer of UV-resistant gel coat. In order to meet the application’s high wind speed requirements, each cabinet is equipped with special built-in mountings – which are external to the thermally insulated parts of the enclosure – to secure the top and base to Prelude’s deck structure. All external metal components are fabricated from 316 stainless steel with a corrosion-resistant protective coating that is specified for ship use.

Each of the 120 Intertec cabinets incorporates a unique form of semi-passive cooling technology. The internal face of the cabinets' rear walls are fitted with a high efficiency heat exchanger, comprising one or more aluminum cooling plates and stainless steel coolant pipes connected to Prelude’s cold water supply system, which obtains ‘cold’ water from the deep sea by a 150 m long pipe below the vessel. Heat dissipated by the equipment in the cabinets is absorbed by the water and transferred to the vessel’s main water cooling system, where it is dissipated to the environment. The size of each cabinet depends on the power dissipation of the contained sample conditioning or process analyzer system, which ranges from 140 W to 900 W.

This form of distributed cooling has enormous technical and economic advantages, especially in hazardous areas or where space and weight is at a premium. It provides a very efficient means of removing heat from the cabinets without requiring local air conditioning systems, which would necessarily need to be explosion proof – and therefore expensive. Furthermore, transferring heat from individual air conditioners of below-deck cabinet installations to the ambient environment would be a major challenge and involve significant amounts of space-consuming air ducting. The semi-passive cooling system is inherently safe for use in a hazardous environment; at the cabinet level it requires little or no electrical power of its own and is virtually maintenance-free, making it ideal for long life-cycle applications.

The intended operating environment for Shell’s Prelude FLNG vessel poses significant instrumentation protection challenges. The BrowseBasin is very close to the Equator, which means that it has a tropical climate with an average temperature of about 32 degrees Celsius. This moist and hot environment, combined with a salt-laden atmosphere, is highly conducive to rust formation, making non-metallic protection cabinets a sensible design choice. In some of Prelude’s more confined spaces, the ambient temperature could reach more than 50 degrees Celsius. Even under these extreme conditions, all of the passively-cooled cabinets that Intertec is producing for the project are designed to keep their internal air temperature below 35 degrees Celsius.
 

  • Semi-passive cooling technology is fitted into each instrumentation protection cabinet that Intertec has produced for Shell’s Prelude FLNG project - avoiding the need for expensive and large explosion-proof air conditioning equipment.

    Semi-passive cooling technology is fitted into each instrumentation protection cabinet that Intertec has produced for Shell’s Prelude FLNG project - avoiding the need for expensive and large explosion-proof air conditioning equipment.

Maritime Reporter July 2014 Digital Edition
FREE Maritime Reporter Subscription
Latest Maritime News    rss feeds

Technology

Wärtsilä Signs Harvey Gulf OSV Maintenance Agreement

Wärtsilä says it has signed a long-term Technical Management Agreement with Harvey Gulf International Marine LLC (Harvey Gulf). This five-year agreement covers

ARENA Supporting Bright Ideas in Solar R&D

The Australian Government today announced $21.5 million funding for 12 cutting edge R&D projects that will keep Australia at the forefront of solar research.

WR Nominated for International Seatrade Insider Cruise Award

WR Systems has been shortlisted for the Environmental Initiative Award. Judged by an independent panel of experienced cruise industry specialists, the Seatrade

Tanker Trends

Latest Ocean-Going Shipbuilding Orders

Clarkson Hellas notes in its latest 'S&P Weekly Bulletin' shipbuilding orders placed in the dry bulk, tankship, gas carrier and containership sectors, as follows: Dry

Livanos Becomes Euronav Chairman

On 22 July 2014, the Board of Directors of Euronav NV unanimously appointed Peter G. Livanos as Chairman of the Board, with immediate effect in replacement of Marc

MN 100: gplink

1500 Sensation Weigh Beaufort, NC 28516 Tel: (252) 504-2640    Email: dwebb@gplink.com Website: www.gplink.com President & CEO: Greg Poole, III The Company: gplink

Energy

Narendra Modi Eyes Breakthrough Nuclear Pact with Japan

India is hoping to win Japanese backing for a nuclear energy pact during a visit by Prime Minister Narendra Modi, and lure investment into its $85 billion market

Venezuela Considers Importing Crude for the First Time

PDVSA would use its own fleet to transport imported crude; Purchases of crude imports would reduce costs; Venezuela has been exporting oil for a century Venezuela

ARENA Supporting Bright Ideas in Solar R&D

The Australian Government today announced $21.5 million funding for 12 cutting edge R&D projects that will keep Australia at the forefront of solar research.

LNG

LNG Finalizes Acquisition of Bear Head LNG Project

Liquefied Natural Gas Limited today informed having finalised the acquisition of 100% of Bear Head LNG Corporation (BHLC). This follows the announcement

Latest Ocean-Going Shipbuilding Orders

Clarkson Hellas notes in its latest 'S&P Weekly Bulletin' shipbuilding orders placed in the dry bulk, tankship, gas carrier and containership sectors, as follows: Dry

Seaborne Ethane and Demand for a New Ship Type

Lloyd's Register report looks at the commercial landscape, regulatory issues and technical realities of a new trade in ethane emerging as a result of increased U.

Marine Equipment

Reflex Marine to Bring FROG-6 into Mexico

Reflex Marine has been granted approval by the Mexican Merchant Marines to sell its crane transfer device, the FROG-6, in Mexico. The certification is a result

MN 100: Scania USA Inc.

121 Interpark Blvd. Ste. 1002 San Antonio, Texas 78216 Tel: (210) 679-3126  Email: smurdock@scaniausainc.com Website: www.scaniausa.com President & CEO:

MN 100: gplink

1500 Sensation Weigh Beaufort, NC 28516 Tel: (252) 504-2640    Email: dwebb@gplink.com Website: www.gplink.com President & CEO: Greg Poole, III The Company: gplink

Vessels

Oceanteam Focuses on Mexico Strategy

Oceanteam Shipping ASA releases its Q2 2014 financial report, with extracts as follows: The company says it saw, with its early focus on Mexico, a long term

Wärtsilä Signs Harvey Gulf OSV Maintenance Agreement

Wärtsilä says it has signed a long-term Technical Management Agreement with Harvey Gulf International Marine LLC (Harvey Gulf). This five-year agreement covers

Euronav Books Profit from Sale of Chartered Ship

The owner of the 157,258 dwt containership Cap Isabella (built 2013), a vessel which Euronav had on bareboat charter, decided to sell the vessel to an unrelated third party.

 
 
Maritime Contracts Maritime Security Maritime Standards Navigation Pod Propulsion Port Authority Salvage Ship Electronics Shipbuilding / Vessel Construction Winch
rss | archive | history | articles | privacy | terms and conditions | contributors | top maritime news | about us | copyright | maritime magazines
maritime security news | shipbuilding news | maritime industry | shipping news | maritime reporting | workboats news | ship design | maritime business

Time taken: 0.1669 sec (6 req/sec)