Global First Suezmax LNG Dual-Fueled Tanker Delivered

Wang Jin, Kuang Zhanting, Peng Yonggui, Fu Zhiguan, Zhong Wei

The first ship of 158,000 DWT LNG dual-fueled tankers GREENWAY, designed by MARIC，the CSSC No.708 Research Institute and built by Guangzhou Shipbuilding International (GSI), was officially delivered on June 28. The ship is not only the largest LNG dual-fuel green ship built in South China, but also the world's first Suezmax LNG dual-fueled tanker.

The Suezmax ship refers to one with the upper limit of the Suez Canal navigation conditions and about 150,000 DWT. The 158,000 DWT LNG dual-fuel tanker is about 274 m in overall length, 48 m in molded breadth, 23.7 m in molded depth and has a service speed of 14.2 knots. In fuel and gas mode,it can meet IMO Tier III emission standards; in LNG mode, it can reduce carbon dioxide emissions by about 20% and nitrogen oxide emissions by about 85% and particulate matter and sulfur oxide emissions by about 99%.

The main engine of the ship has a high-pressure selective catalytic reduction (SCR) system, which can meet the most stringent emission requirements in all waters and ports around the world. The system theory is to spray ammonia, urea, or other nitrogen-containing compounds into the exhaust gas containing nitrogen oxides to reduce the nitrogen oxides to nitrogen gas and water.

The exhaust gas produced by the main engine of the ship enters from the exhaust pipe into the evaporation mixing pipe, and then enters the SCR reactor through the reducing agent reaction, and the exhaust gas is converted into nitrogen and water under the action of the catalyst in the reactor, so as to realize the purification of nitrogen oxide. In the installation and commissioning of the system, GSI cooperated with the engine manufacturer to carry out stress calculation, scientifically arranged the fixed pipe code, which solved the vibration problem of the system and pipe, and accumulated experience for the construction of subsequent ships.

The ship's LNG gas supply system can transform the liquid fuel in the LNG tank through the pump and evaporator / heater into gas which meets appropriate temperature, pressure,flow rate and other conditions, so as to meet the use requirements of the main engine, generator, boiler and other equipment. To ensure full combustion of LNG, the ship's main engine uses a high-pressure LNG system for gas supply, with an internal gas pipeline pressure of 350bar and 525bar during a double-wall pipe pressure test.

The pressure of 350bar is equivalent to the pressure generated by the 3500 m water column, and the pressure in the pressure cooker commonly used in our daily life is about 1bar. Just imagine the pressure in the ship's high pressure LNG gas supply system!

In the construction process of the ship, GSI first undertook the design and production of the high pressure LNG system pipe using the doublewall pipe structure. The inner pipe undertakes the transmission of high pressure LNG, the outer pipe plays a protective role, and there is mechanical ventilation between the inner and outer pipe walls. The successful application of the technology on this ship provides a reference for the subsequent pipeline design and production of related ships.

In the construction course, GSI technicians arranged the breathable mast of the LNG system on the top of the gas treatment room by combining the layout of the gas treatment room and the LNG tank, effectively optimizing the layout space of the deck surface, and saving the materials of the breathable mast and the fixed frame. In addition, the water spray system layout with cooling protection is added to the LNG system tank, gas treatment room and filling station, and the protective water curtain system is also added to the side plate of the LNG filling station area. The design of the system does not have any reference cases, and it is completely conceived and arranged by the designers according to the actual situation of the site, which well meets the relevant requirements of the classification society.

The 158,000 DWT LNG dual fuel tanker is planned to build two.The construction contract was signed on December 3, 2019, which is the first time GSI has built a Suezmax tanker. The delivery of the first ship marks the full coverage in the field of tanker construction. GSI is currently the world's liquid cargo tanker with most types of ships and most complete series.

GSI has been deeply engaged in the development of clean energypowered ships for many years, and has taken the lead in delivering the first inland waterway thousand-ton electric ship, South China's first LNG dual-fueled product oil tanker in China, and the first methanol dualfuel MR-type tanker. At the same time, the world's first "four-drive hybrid" passenger ro-ro cruiser is under construction.

At present, GSI handheld ship orders top 70 ships worth more than 50 billion yuan, of which nearly 40 orders worth about 20 billion yuan are for new dual-fuel green ships, reaching the world's leading level in the field of green ship development, design and manufacturing.