Why the latest pump technology is key to effective LNG carrier conversions

Compressed air systems for X series LNGCs

In October, TMC secured a contract to supply an energy-efficient marine compressed air system and associated equipment for four LNG carriers under construction for Greece’s TMS Cardiff Gas.

“In almost all tenders we participate in, shipowners increasingly emphasise energy and fuel efficiency as well as the lifetime cost of the equipment,” says Mr Tanum.

TMS Cardiff Gas is constructing the four LNG carriers at South Korean shipbuilders Hyundai Heavy Industries (HHI) and Samsung Heavy Industries (SHI). Each vessel will have storage capacity of 174,000 m³, with GTT Mark III Flex membrane cargo containment technology and low-speed, dual-fuel X-DF main engines from WinGD.

Destined to start long-term charters with Shell once they are delivered, the four LNG carriers are part of TMS Cardiff Gas’ X carrier series of orders. Formed in 2011, TMS Cardiff Gas will grow to 16 LNG carriers.

TMC spokesman Endre Johansen tells LNG Shipping and Terminals: “TMC has conducted a lot of R&D work to generate higher capacity output of control and service air, but with lower energy consumption, service requirements and as a result, lower opex and harmful emissions to air.” Mr Johansen says TMC has sought inspiration from the automotive industry, which for several decades has made engines more compact while squeezing out more horsepower and reducing fuel consumption and associated CO₂ emission levels: “For compressors between 150 and 235 kW, for example, TMC has in recent years increased capacity by up to 9.7%, while energy consumption has been reduced by up to 9.2%.” Adds Mr Johansen, “Simply put, more power for less cost.”

TMC’s scope of supply is to provide two control air compressors, one service air compressor and two nitrogen feed air compressors for each of the four vessels. For the LNG carriers being built by HHI, TMC will also supply two selective catalytic reduction (SCR) compressors. TMC’s contract value is undisclosed.

This is not the first contract TMC has been awarded by TMS Cardiff Gas. In June 2018, TMC won a contract to supply a marine compressed air system for three TMC Cardiff Gas LNG carriers being built by HHI.

New test facility supports cryogenic pump and expander line

US-based Elliott Group, a wholly owned subsidiary of Japan’s Ebara Corp, broke ground in December on a new US$60M cryogenic products test facility in Jeannette, Pennsylvania. When it opens in 2021, the test facility will help integrate the manufacture of custom-engineered cryogenic pumps and expanders into its product line. Elliott also manufactures compressors and steam turbines. Integration of the new products follows the completion of the Elliott Group’s merger with Ebara International Corp, Sparks, Nevada in April 2019. Ebara International’s cryogenic pumps and expanders under the Cryodynamics brand name are now manufactured at Elliott’s facility in Jeannette.

Compact in size and about a third of the weight of an external motor pump or expander, with an external generator, the Cryodynamics line of submerged motor pumps and expanders are well suited for installation on FLNG and floating storage and regasification (FSRU) vessels where space is at a premium, says the Elliott Group.

Cryodynamics ECC model pumps are used in high-pressure, send-out service on FSRUs, while retractable ECR model pumps can be employed to service the storage tanks on the vessels, and LX liquid expanders can be used on the FLNG topside module. Vessel-mounted ECC pumps and LX expanders incorporate additional lateral supports to reduce the loads on the suction or discharge vessel-mounting lugs. These supports are derived from shipboard cargo EC pumps. The pump is protected from lateral loads by a lower support rod. In-tank retractable pumps use a deep-seat style suction valve or a rigid retraction system to eliminate the possibility of the pump unseating from the valve seal surface during hull motion.

Nine Cryodynamics pumps and one expander were supplied for Shell’s Prelude FLNG, moored in 250 m of water in the Browse Basin, 475 km offshore of Western Australia. With a production capacity of 3.6 mta of LNG, Prelude FLNG shipped its first commissioning cargo to Asia in June 2019. The Prelude FLNG facility is operated by Shell in a joint venture with Inpex, which has a 17.5% interest, Kogas (10%) and OPIC (5%).

Pump partners

In December, TMC struck a co-operation agreement with Germany’s Sauer Compressors to work together to meet a broad range of air compressor requirements for offshore, marine and shipping companies. While the two companies will continue to operate separately, they believe their complementary product lines of marine and offshore compressors will allow them to offer the complete marine compressed air package that yards and shipowners often want, according to Sauer Compressors COO Harald Schulz.

TMC supplies screw compressors for marine and offshore use, while Sauer Compressors is a global supplier of piston compressors for the commercial shipping, offshore and navy segments. Most vessels require both screw and piston compressors to fulfil their on-board compressed air requirements.

TMC delivers screw compressors in the range from 1.5 to 20 bar pressure, while Sauer provides high-pressure piston compressors for pressures between 20 and 500 bar.

“TMC and Sauer will continue to offer our respective products on a stand-alone basis, but this agreement enables us to co-operate more closely and cost-effectively, which could be highly beneficial for both yards and shipowners,” says TMC chief executive Per Kjellin.