Dorian/Seacor Vessels to Get Enhanced Reliquefaction Systems

Dorian-Seacor Vessels to Get Enhanced Reliquefaction Systems

Dorian/Seacor‘s liquefied petroleum gas (LPG) carriers are to benefit from the latest reliquefaction plant development from Babcock’s LGE Process, following a contract signed last month (May) for the innovative vent gas cooler enhancement to be fitted on two new very large gas carriers (VLGCs) being built for Dorian/Seacor in South Korea, with an option for a possible further three vessels.

The latest plant design enhancement (patents pending) from Babcock’s LGE is based on the innovative application of known and proven technology, to offer reduced capital and operating costs without compromising efficiency and operability. The novel vent gas cooler (VGC) enhances the reliquefaction systems used on gas carriers transporting LPG, ammonia and petrochemical gases with valuable efficiency, flexibility and environmental benefits.

Installed as part of a reliquefaction plant on fully refrigerated LPG carriers, the VGC provides greater refrigeration capacity yield from the same electric power input (improving efficiency), enables additional cargoes to be carried (providing increased operational flexibility), and reduces cargo vapour emissions and losses through venting (offering an environmentally-friendly solution).

The improved coefficient of performance (COP) of the plant – ie increased refrigeration capacity for the same electric power and seawater consumption – is one of the primary benefits of the VGC from which the Dorian/Seacor LPG carriers will benefit. By installing the VGC between the second and third stages of a three-stage compression system on large carriers, increases of 10-15 per cent in the COP can be achieved. This increased capacity allows conventional four compressor systems to be replaced by three slightly larger ones.

The system has been ordered by Dorian/Seacor for two new fully refrigerated 84,000 m³ VLGCs to be built for the company at the Hyundai Heavy Industries (HHI) shipyard in South Korea. As a result, these vessels will benefit from a three-compressor solution, with increased capacity and performance, reduced power consumption, and a lower overall build cost.

“We are delighted that the Dorian/Seacor vessels will benefit from our VGC innovation, which is designed to improve compression refrigeration systems through evolution rather than revolution, bringing valuable advantages such as reduced costs and improved performance,” Babcock’s LGE Process General Manager Andrew Scott said.

“Operating cost savings are achieved through a number of factors. For example, fuel consumption to provide electric power to drive the reliquefaction compressors is reduced. Additionally the increased refrigeration capacity for the same heat loads results in shorter operating periods, thereby also reducing the maintenance requirements for rotating machinery with greater intervals between overhauls. The VGC can equally easily and beneficially be fitted as retrofits to existing ships too, delivering the same advantages,” Scott added.

The vessels are due for delivery in 2014.


Babcock, June 21, 2013