Zhong Chuan

On March 24, 2018, the first smart main engine 6S35ME-B MK 9.5 equipped with high pressure SCR system manufactured by the Dalian Marine Diesel Engine Co Ltd (DMD) successfully performed delivery-check. “Equipped with high pressure SCR system” means the engine complies with IMO highest emission standard -- Tier Ⅲ and has become the first marine engine product by DMD meeting the standard.

Over recent years, DMD has held the concept of “Making high quality main engine and taking the brand path”,kept a close watch on market demand,laid emphasis on development of costeffective, environment-friendly, smart and new products with extra large cylinder diameter, further strengthened its manufacturing capacity of environmentfriendly and smart low-speed marine engine, and laid a solid foundation for occupying a strong position amidst fierce market competition.

Tracing back to the beginning of 2017, by changing management strategy and innovating marketing model, DMD secured a 2+3 6S35ME-B MK 9.5 main engine order from AVIC Ship, providing power for the 7999 dwt chemical tanker Swedish shipping company SIRIUS ordered to AVIC Ship. This was not only the first cooperation between DMD and AVIC Ship, but also the Company’s first undertaking a main engine order which complies with the Tier Ⅲ emission standard.

6S35ME-B MK 9.5 main engine applies the latest design patent technology of Man Diesel & Turbine, with a rated power of 5220 kW, equipped with Hitachi high pressure SCR system, when high sulfur fuel oil is used, its NOx emission value does not exceed 2g/kWh, by far less than the limiting value of the IMO TierⅢ standard 3.4g/kWh. Not only so, SCR system installed on the engine is also the world first reactor bypass valve (RBV)SCR system mounted in the exhaust constant pressure pipe.

This means the 6S35ME-B MK 9.5 engine production difficulty is selfevident: As a small cylinder bore main engine with high pressure SCR system,its layout space is limited, hence more accurate design of layout and position of main engine piping, electric appliances and ancillary equipment as well as corresponding adjustment of welding processing technique. In order to ensure delivery of high quality main engine to the client, DMD made complete preparations for process measures, process control and supporting organization. Technicians played a leading role, earnestly digested and absorbed technical information of the patent companies and SCR manufacturer, based on practical needs of production and processing, revised the original design of main engine parts, and independently completed the SCR testing platform and piping design. On this basis, all departments made concerted effort, made close cooperation, jointly solved relevant challenges and completed purchasing and installation of parts.

It was very cold during the main engine commissioning period. In order to obtain the most complete data, relevant personnel were often so busy as to stay up all night, solving problems that cropped up from the commissioning. They only took six days to succeed in all tests under Tier Ⅲ operation mode, adjust the main engine to optimal state and create “DMD speed” in the SCR system main engine commissioning.

The successful development and delivery-check of 6S35ME-B MK 9.5 main engine not only enabled DMD to accumulate “engine + SCR” project experience and enhanced development capability and confidence in the main engine meeting the Tier Ⅲ standard,but also paved the way for the Company undertaking environment-friendly, smart low-speed diesel engine order in future.

In fact, 6S35ME-B MK 9.5 main engine is not alone. Since the outburst of the international financial crisis in 2008,the shipping market has been extremely depressed and the engine-making market competition has been unusually fierce. Not afraid of shock, conforming to the trend and keeping tight tracking of world advanced DMD engine-making technology, DMD has been vigorously promoting technological innovation and product upgrading and striving to build“DMD” brand. In 2016, the Company successfully developed and manufactured three first models -- 6S40ME-B 9.5,6S50ME-C 9.5 and W5X40-B, among which 6S50ME-C 9.5 main engine was not only DMD’s first, but also world first product.

In the above three models,W5X40-B engine was successfully delivered for check at the end of 2016;during the development, DMD focused on research of product design improvement,large main engine assembly technology,large structural component welding processing technology and large moving parts processing and manufacturing technology, broke through several key manufacturing technical challenged and accumulated valuable experience in manufacturing small cylinder bore main engines. In December 2017, the engine development project passed CSIC scientific and technological achievement appraisal, experts unanimously believed the manufacturing technology reached the international advanced level, obtained patent technology with independent IPRs, comprehensively improved the Company’s core competitiveness in the marine low-speed diesel engine manufacturing sector, and laid a solid technical foundation for the Company batch undertaking such main engines in future.

DMD’s another first product --6G50ME-C eco-friendly main engine was successfully delivered for check in July 2017. The maximum power was 8820 kW, compared with S main engine, it had longer stroke and lower speed, with higher matching efficiency of engine and propeller and lower fuel consumption. Through optimal design,6G50ME-C engine was equipped with LDCL system, RDL cylinder sleeve,EGB valve regulating equipment, bearing wear monitoring system, fuel (ELFI) and exhaust (ELVA) control valve and other new equipment, extending overhaul interval and reducing shipowner’s operation cost while meeting the humanization design requirement.

To do a good job of 6G50ME-C engine, DMD technicians actively communicated with all manufacturing departments and patent companies at the drawing preparation stage, conducted timely feedback of drawing problems and ensured accuracy of welding, processing and assembly; for ship survey approval matters, conducted timely communication with the ship survey agency, and realized timely review of drawings; according to the shipyard requirements of revising top support and pipe interface, checked dimensions and ensured smooth operation of production. ★