Introduction of the Latest Mitsubishi UE Engine Technologies*

Introduction of the Latest Mitsubishi UE Engine Technologies * Introduction of the Latest Mitsubishi UE Engine Technologies* Ippei TERATA Akihito AOTA Koji EDO ** Ippei TERATA, Akihito AOTA and Koji EDO** Mitsubishi Heavy Industries Marine Machinery & Engine Co., Ltd. (-MME) has developed a new generation low-speed marine diesel engine, the UEC50LSH-Eco, for a wide output and speed range that includes the chemical tankers and Supramax and Handy-size Class bulk carriers and medium range tankers. The UEC50LSH-Eco has been developed on the principal design concepts of high efficiency and environmental friendliness and based on technologies accumulated from many years of technical development activities of Mitsubishi UE Engines. The UEC50LSH-Eco achieves extremely low (Specific Fuel Oil Consumption) owing to an improved trade-off relationship between and NOx obtained by an optimized fuel injection pressure and rate, reduction of mechanical loss, and high efficiency of the exhaust gas and scavenging air system. Moreover, further reduction can be achieved with Mitsubishi s MET Turbocharger technologies. Recently, -MME also released a new UEC-LSE series that includes the UEC-Eco electronically controlled engines, to comply with IMO-NOx Tier 2 regulations and market needs to save energy. All of these UE engines are in service and demonstrate excellent performance. 1. Introduction Mitsubishi UE engines feature high economic efficiency, high reliability, and environmentalfriendliness. The high economic performance of the UE engine can save ship owners operating costs for fuel oil and cylinder lubricating oil. Thus, many new UEC-LSE engines have recently been released in addition to the latest UEC-LSH series. Fig. 1 shows the latest naming rules for the UE engines, using 6UEC50LSH-Eco-C2 as an example. These rules newly add BMEP numbers B & C, which means BMEP (Brake Mean Effective Pressure) is more than 21 bar, and low version 2 as a version number. The UE engines have been developed and improved for more than half a century. Now, the full lineup of the UEC-LSE series have been rounded out (Fig. 2). 6 50 H C 2 Fig.1 Naming rules of Mitsubishi UE engines LSE series LSII Type L/LA/LS Type LSH series 50LSH-Eco 40LSE 33LSE 80LSE-Eco 35LSE Eco 45LSE Eco 50LSE Eco 60LSE Eco 68LSE 52LSE Eco Eco H/HA Type A/B/C/D/E Type 1955 1950 1960 1970 1980 1985 1990 1995 2000 2005 2010 2015 Fig.2 Development history of Mitsubishi UE engines *Received, 2015 * *Mitsubishi Heavy Industries Marine Machinery & Engine Co., Ltd. Electronically controlled engines, that is the UEC-Eco series, have also been in service since 2005. Fig.3 shows the percentage of production of Journal Journal of the of JIME the JIME Vol. 50, Vol.00,No.00(2005) 6(2015) -1-2

Introduction of the Latest Journal Mitsubishi of the JIME UE Engine Technologies 708 these UEC-Eco engines, which has rapidly increased since 2012. In addition, UE engines produced since 2010 comply with IMO-NOx Tier 2 regulations. The percentage of IMO-NOx Tier 2-adapted engines is shown in Fig. 4. Adaptation has been achieved by modifications to the scavenging air system and fuel injection system, and so on. The scavenging air system of these engines apply the Miller Cycle, a higher compression ratio, a lower scavenging air temperature and an optimized scavenging air swirl. The fuel injection system optimizes the fuel injection timing, fuel spray pattern and fuel injection rate. The fuel injection rate is controlled electronically. In this paper, the latest UE engine technologies and developments are reported. Percentage of UEC Eco engine [%] Percentage of Tier2 adapted engine [%] 70 60 50 40 30 20 10 0 2010 2011 2012 2013 2014 2015 Year Fig.3 Percentage of electronically controlled Eco engines 100 90 80 70 60 50 40 30 20 10 0 2010 2011 2012 2013 2014 2015 Year Fig.4 Percentage of IMO-NOx Tier 2 adapted engines 2. DEVELOPMENT OF THE NEW UEC50LSH-Eco The main particulars and the output and rotation speed rating of the UEC50LSH-Eco-C2 are shown in Fig.5. Engine type 6UEC50LSH -Eco-C2 Bore mm 500 Stroke mm 2,300 Stroke / Bore - 4.6 Rated output kw 10,680 Rated speed min -1 108 BMEP MPa 2.19 Piston speed m/s 8.28 g/kwh 164 Fig. 5 Main particulars (Left) and output and The development concepts of the UEC50LSH-Eco are as follows. (1) Lower fuel oil consumption - Lower fuel oil consumption is achieved by combining a longer stroke and lower engine speed, which benefits the ship operator. (2) Wide rating field - The UEC50LSH-Eco covers a wide rating field from 85 min -1 to 108 min -1, which benefits the shipyard. (3) Compact engine size - The compact size and lighter weight help to lower the engine builder s manufacturing costs. (4) New conceptual electronically controlled engine. - Electronically controlled fuel oil injection and starting air system - Camshaft-driven exhaust valve system - Driving oil for the electronically controlled system supplied by low capacity, electric high pressure pumps In addition, the UEC50LSH-Eco can comply with IMO-NOx Tier 3 regulations when combined with the electronically controlled system and EGR/SCR [1],[2]. The first UEC50LSH-Eco are shown in Fig. 6 and have finished sea trials in August 2015 and entered service in September 2015. 2.1 Concepts of The UEC50LSH-Eco The UEC50LSH-Eco is the main engine targeted for chemical tankers, Supramax bulk carriers, Handy-size bulk carriers, medium range tankers and chip carriers. Journal of the JIME Vol.00,No.00(2005) -2- Journal of the JIME Vol. 50, No. 6(2015) 3

709 Introduction 日本マリンエンジニアリング学会執筆要項 of the Latest Mitsubishi UE Engine Technologies Bedplate and column - Stiffer and lighter by adoption of a single wall structure Tie bolts - High stiffness and light weight with twin tie bolts and low alloy steel Main bearing and crankpin bearing - Made of aluminum metal - Stiffer fatigue strength Cylinder jacket - High stiffness and lighter weight owing to an optimized shape Fig.6 First 6UEC50LSH-Eco-C2 (2) Combustion chamber Details of the combustion chamber are shown in Fig. 9. The features of each part are as follows. 2.2 Structure of The UEC50LSH-Eco A representative outline and structure of the 6UEC50LSH-Eco-C2 are shown in Fig. 7. New concept Eco system reduction by electric hydraulic pump Zero-sac FOV Higher reliability by reduction of HC 3 FOVs per cylinder More uniform combustion Tie bolt High stiffness and light weight by twin tie bolt and low alloy steel Reduction of deformation of main bearing Cylinder jacket High stiffness by optimized shape Exhaust valve Higher reliability by nimonic Piston Higher reliability by bore cooling and high top land Piston ring Reduction of maintenance cost with 3 stage ring package Cylinder liner Simple structure by slim type Appropriate temperature control by bypass line A-ECL system Reduction of running cost by lower cylinder oil consumption Bedplate & Column High stiffness and light weight by adoption of single wall New design for 50LSH Main bearing & Crankpin bearing Improved fatigue strength by aluminum metal Proven design by existing LSE-series Fig. 7 Structure of 6UEC50LSH-Eco-C2 (1) Main structure Details of the main structure are shown in Fig. 8. The features of each part are as follows. Fig. 8 Details of the main structure Fig. 9 Details of combustion chamber Piston - Bore cooling and high top land to reduce the thermal load of the cylinder liner - Prevents fuel oil sulfur from adhering to the cylinder liner wall. Piston ring - Reduced maintenance costs and prolonged service-life owing to hard coating rings in three stages Cylinder liner - Simplified by adoption of a no-bore cooling type liner - The cooling water temperature is controlled appropriately by a bypass line. Cylinder lubricating system - A well-proven A-ECL (Advanced Electronically Controlled Lubricating) system is applied. This Journal of the JIME Vo00, No. 00-3- 日本マリンエンジニアリング学会誌第 00 巻第 00 号 (0000-00) Journal of the JIME Vol. 50, No. 6(2015) 4

Introduction of the Latest Journal Mitsubishi of the JIME UE Engine Technologies 710 A-ECL system has already accumulated extensive service experiences with good results. - The piston rings and cylinder liner are kept in excellent condition. - Reduced cylinder oil consumption and prevention of cylinder liner low-temperature corrosion by wide range injection at the appropriate timing. Fuel injection system - Hydrocarbons are reduced by zero-sac fuel injection valves. - Uniform combustion and improved trade-off performance between fuel oil consumption and NOx by configuring three valves per cylinder and controlling fuel injection rate - Fuel oil consumption is improved by controlling the fuel injection rate with the mechanism shown in Fig. 10. Two sets of main valves and solenoid valves are mounted to control the injection rate. Each of the main valves is controlled by solenoid valve, and hydraulic oil is supplied to the fuel pump through the main valves. Fuel injection rate is controlled as shown in the figures by differences in the main valve s lift and valve open timing. This controlled fuel injection rate improves the trade-off relationship between thermal efficiency and NOx emission as shown in Fig. 11. Exhaust valve - The exhaust valve is driven by a camshaft. - The exhaust valve is made of Nimonic and features an extended maintenance interval. - A welded type of exhaust valve made of heat-resistant steel also can be applied in the near future. Fuel injection press. Fuel injection press.(kgf/cm2) [kgf/cm2] Relative rate(%) [%] 900 600 300 0 110 105 100 95 90 85 80 Fuel injection control OFF Fuel injection control ON rate Fuel injection control OFF Fuel injection control ON 100% 99.5% 100% NOx rate Normal Load 1kgf/cm2=0.098MPa 89.8% Fig. 11 Effect of fuel injection rate control (3) Eco system A newly conceptualized electronically controlled system is applied to the UEC50LSH-Eco as below. Hydraulic system - Details of the Eco hydraulic system are shown in Fig. 12. - Electric hydraulic pumps are adopted for the Eco system. Control system - The Eco control system and peripheral equipment are connected by network communications. - Cylinder pressure is adjusted by feedback control of the Eco control system. Electric driven hydraulic pumps Control valve block with solenoid valve unit Fuel injection pump Cylinder control box Hydraulic oil rail Main solenoid valve to Fuel injection pump Pilot oil High pressure hydraulic oil 1 2 Main valve High pressure Pilot oil hydraulic oil [Control mechanism] Fuel injection rate controlled by two main valves opening timing Main valve opening timing are controlled by each solenoid valves Controlled fuel injection rate contributes to improve the trade-off relationship of NOx emission and FOC. Main valve lift Fuel injection pressure Concept of fuel injection mode Crank angle from control signal (deg) Fig. 10 Fuel injection rate control mechanism Fig. 12 Details of Eco hydraulic system 3. LATEST LINEUP OF UEC-LSE ENGINES The latest UEC-LSE series that was released before the UEC-LSH series is introduced in this section. 3.1 UEC80LSE-Eco-B1 The UEC80LSE-Eco-B1 shown in Fig. 13 is a main engine developed as the best engine for VLCC and VLOC. The main particulars and the output Journal of the JIME Vol.00,No.00(2005) -4- Journal of the JIME Vol. 50, No. 6(2015) 5

日本マリンエンジニアリング学会執筆要項 Introduction of the Latest Mitsubishi UE Engine Technologies 711 and rotation speed rating are shown in Fig. 14. The first 7UEC80LSE-Eco-B1 has been put into service and excellent performance has been confirmed. results show the high reliability and performance of the UE engine s combustion chamber and cylinder lubricating system. Fig. 15 Conditions of combustion chamber piston (left) and cylinder liner (right) 3.3 UEC33LSE-C2 The UEC33LSE-C2 shown in Fig. 16 is a main engine targeted for small chemical tankers under 20,000 dwt, domestic vessels, container ships, cargo ships, multipurpose vessels and the like. Fig. 13 First 7UEC80LSE-Eco-B1 min bar m/s 7UEC80LSE -Eco-B1 800 3,150 3.9 31,080 80 21 8.4 g/kwh 166 Engine type Bore Stroke Stroke / Bore Rated output Rated speed BMEP Piston speed mm mm kw -1 Fig. 14 Main particulars (Left) and output and 3.2 Combustion Chamber Conditions of 7UEC80LSE-Eco in Service A high top land piston is applied to the UEC 80LSE-Eco engine, which prevents the lubricating oil film from being damaged by combustion gas. In addition, the cylinder liner temperature is also controlled properly, as there has not been a cylinder liner worn down by low-temperature corrosion. The lubricating oil feed rate of the 7UEC80LSE-Eco has been reduced to 0.88 g/kwh (when using fuel oil sulfur 2.9% and cylinder oil BN70), almost in accordance with the guidance. The feed rate can be reduced further by confirming combustion chamber conditions. The piston rings and cylinder liner are also shown in Fig. 15 (total running time : 5590 hr). They are in excellent condition as there is no low-temperature corrosion. The piston ring wear rate is less than 0.03 mm/1000 hr. These Journal of the JIME Vo00 No 00 Journal of the JIME Vol. 50, No. 6 2015 Fig. 16 First 6UEC33LSE-C2 The main particulars and the output and rotation speed rating of the UEC33LSE-C2 are shown in Fig. 17. The UEC33LSE is a strategic model that meets the market demands for small vessels because its output and rotation speed rating are not covered by other low-speed engines, and it can also be used to replace medium-speed engines due to its lower fuel consumption rate. A mechanical type of UEC33LSE has already been released with a fuel consumption rate as low as competitor electronically controlled engines. Fuel consumption reduction through longer piston strokes and improvement in the Energy Efficiency Design Index (EEDI) and enhanced propeller efficiency through lower rotation speeds are the primary development concept of the UEC33LSE. The first UEC33LSE was completed in May 2014. 5 日本マリンエンジニアリング学会誌 第 00 巻 第 00 号 (0000-00) 6 日本マリンエンジニアリング学会誌 第50巻 第 6 号 2015

Introduction of the Latest Journal Mitsubishi of the JIME UE Engine Technologies 712 Engine type 6UEC33LSE-C2 Cylinder bore mm 330 Piston stroke mm 1,550 Stroke/Bore - 4.7 Rated output kw 4,980 Rated speed min -1 167 BMEP MPa 2.25 Piston speed m/s 8.6 g/kwh 174 Fig. 17 Main particulars (Left) and output and 3.4 UEC45LSE-Eco-B2 The UEC45LSE-Eco-B2 shown in Fig. 18 is a main engine targeted for Handy-size bulk carriers, small chemical tankers, container ships and so on. The main particulars and the output and rotation speed rating are shown in Fig. 19. The UEC45LSE-Eco-B2 was developed on the proven best-selling UEC45LSE-1 and applies new technologies established with other recent UE engines. The first UEC45LSE-Eco-B2 entered service in September 2014. 3.5 UEC60LSE-Eco-A2 The UEC60LSE-Eco-A2 is a main engine suitable for PCTC, Panamax bulk carriers, coal carriers, 2000TEU class container ships and so on. The first UEC60LSE-Eco-A2 successfully finished shop tests in March 2014 (Fig. 20). The main particulars and the output and rotation speed rating of the UEC60LSE-Eco-A2 are shown in Fig.21. The UEC60LSE series engines were released in 2007 and have proven to be highly reliable as seen by production records. This engine is especially suitable for PCTC because of its low piston dismount height and advantages gained from its low fuel oil consumption. The UEC60LSE-Eco-A2 can provide superior performance in combination with a cylinder pressure control system (Pmax feedback system). The first engine entered service in September 2014, and shows good performances. Fig. 20 UEC60LSE-Eco-A2 engine in a shop Engine type 6UEC45LSE -Eco-B2 Bore mm 450 Stroke mm 1,930 Stroke / Bore - 4.29 Rated output kw 8,280 Rated speed min -1 128 BMEP bar 21.1 Piston speed m/s 8.23 g/kwh 170 Fig. 18 UEC45LSE-Eco-B2 Fig. 19 Main particulars (Left) and output and Engine type 7UEC60LSE -Eco-A2 Bore mm 600 Stroke mm 2,400 Stroke / Bore - 4 Rated output kw 14,280 Rated speed min -1 105 BMEP MPa 2.0 Piston speed m/s 8.4 g/kwh 168 Fig. 21 Main particulars (Left) and output and Journal of the JIME Vol.00,No.00(2005) -6- Journal of the JIME Vol. 50, No. 6(2015) 7

713 Introduction 日本マリンエンジニアリング学会執筆要項 of the Latest Mitsubishi UE Engine Technologies 4. PROJECT MEET PACKAGES WITH UEC60LSE-Eco-A2 -MME has the responsibility to protect and sustain the earth's environment, including its beautiful and life-giving oceans. In fulfilling this responsibility, -MME provides marine solutions that meet the needs of our customers by delivering superior energy efficiency and reduced environmental impact. Project MEET (Mitsubishi Marine Energy & Environmental Technical Solution-System) is the cornerstone of -MME's ongoing quest to meet the energy and environmental needs of today's marine machinery and engine market, with the technology of tomorrow (Fig. 22). The first UE engine installed with a hybrid turbocharger entered service in March 2015. Fig. 26 shows an outline of the hybrid turbocharger and Fig. 27 shows its power generation output. We confirmed that the hybrid turbocharger can recover about 290 kw of energy from its generator in 100% load operation. Thus, -MME can provide the best solutions for wide market through combinations engineered in Project MEET. On/Off Valve Gas inlet inner casing UE engine + MEET1 package UEC Eco-Engine VTI turbocharger Electric assist turbocharger Electric deck crane Electric deck machinery Fig. 23 VTI turbocharger MALS (Mitsubishi Air Lubrication System) MTA blower for MALS Waste heat recovery equipments Electric steering gear MAP Mark-W New exhaust gas economizer Lithium battery Hybrid ORC turbocharger MERS Valve open Valve close Nozzle area : Large (Valve open) Nozzle area : Small (Valve close) Fig. 22 Project MEET Fig. 24 Acting mechanism of VTI Successful packages are already available with the UEC60LSE-Eco-A2 and other recent engines, in combination with a VTI (Variable Turbine Inlet) turbocharger or hybrid turbocharger. The VTI turbocharger can be easily retrofitted on vessels in service and improves engine performance with high scavenging pressure by changing the nozzle passage area in low load operation. Fig. 23 shows the VTI turbocharger and Fig. 24 shows the acting mechanism of the VTI. The VTI decreases nozzle area under low load and accelerates exhaust gas pass through the turbine blade so as to increase scavenging pressure and reduce fuel oil consumption [3]. Fig. 25 shows the reduction in fuel oil consumption from the VTI turbocharger. The VTI can reduce fuel oil consumption about 4 g/kwh at 65% load and 3 g/kwh at 40% load. The open/close switching load at 65% is set as the standard in consideration of operating needs. In some projects, the switching load can be increased to around 70~75% load. FOC [g/kwh] Based on original 50% load 12 10 8 6 4 2 0-2 -4-6 -8 VTI CLOSE -10 20% 30% 40% 50% 60% 70% 80% 90% 100% Operating load [%] Original VTI VTI OPEN Fig. 25 Reduction in FOC by VTI turbocharger Journal of the JIME Vo00, No. 00-7- 日本マリンエンジニアリング学会誌第 00 巻第 00 号 (0000-00) Journal of the JIME Vol. 50, No. 6(2015) 8

Introduction of the Latest Journal Mitsubishi of the JIME UE Engine Technologies 714 References Fig. 26 Hybrid turbocharger with UEC60LSE-Eco-A2 [1] Development of Exhaust Gas Recirculation System for Exhaust Gas Emission Control of Mitsubishi UE Diesel Engine, T. Ueda, K. Ito, J. Yanagi, and N. Hiraoka, ISME Harbin (2014) [2] Exhaust Emission Control of Mitsubishi UE Diesel Engine, N. Hiraoka, K. Imanaka, CIMAC Congress 2013, Shanghai, (2013), paper No. 418 [3] 減速運転 -メリットと注意点, J. Yanagi, Journal of the JIME Vol.49, No.1 (2014) 300 Power generation output (ISO) [kw] 250 200 150 100 Engine output at 100% load 13815kW,105rpm 50 45 50 55 60 65 70 75 80 85 90 95 100 105 Operating load [%] Fig. 27 Power generation amount 5. Conclusions This paper discussed the new generation UEC50LSH-Eco engine that is based on conventional high reliable UE engines and further improvements. The UEC50LSH-Eco suits growing environmental needs including IMO-NOx Tier 3 regulations and helps ship owners, ship operators and shipyards to cut operating and manufacturing costs. In addition, a full lineup of the UEC-LSE series and Eco engine have been completed, and the UE engines comply with IMO-NOx Tier 2 regulations. The latest UE technologies achieve a lower cylinder oil feed rate and higher performance of the combustion chamber. The first 6UEC50LSH-Eco-C2 has been completed and entered service in September 2015. -MME will continue to serve the environmental and economic needs of customers around the world. Journal of the JIME Vol.00,No.00(2005) -8- Journal of the JIME Vol. 50, No. 6(2015) 9