Development of UEC52LSE Diesel Engine
Ryoji NAKANO* and Shigemi ONO*
We have developed UE type diesel engine since 1955. The realization of all the models in the Mitsubishi UEC-LS II series engine was completed in 1998. Over 200 units have been operated with good performance and reliability. Based on these satisfactory service results, we started the development of the new UEC52LSE type engine in order to achieve the realization of high power in the future and respond to the social needs such as environmental requirements. This engine is a high power and high cost efficiency engine which is higher by 15% in the power ratio and the same fuel consumption ratio compared with the conventional engines. We have verified the design of this engine by making full use of our latest technologies and knowledge. We have analytically confirmed the expected performance and its reliability and thus completed the development recently.
Key Words: UE, UEC52LSE Diesel Engine Development,
Mitsubishi Heavy Industries, Ltd. has been manufacturing the UE type diesel engines of our own development since 1955. It developed the UEC37LS II type engine in 1998, and thus a series of the newest type UEC-LS II engines was developed. More than two hundred units of the UEC-LS II engines have already been in service and every engine has favorably been operated with good performance and reliability.
Mitsubishi Heavy Industries, Ltd. set about the development of the UEC52LSE type as engines with high output and high economy which could meet social needs such as the trend of ship demand and environmental requirement in future. In its development stage, the design concept of the UEC-LS II type engines with good service results was adopted as a design basis. The verification of its design was also implemented in performance and reliability aspects, actively using the newest technologies of the company such as FEM analysis, various kinds of simulation for performance, injection systems, valve actuating systems and main bearing characteristics as well as flow analysis of scavenging air and exhaust gas, in order to realize further high output and high economy.
This paper reports results of design verification for the UEC52LSE engine.
2. OUTLINE OF UE DIESEL ENGINES
Table 1 shows principal particulars of the newest UEC-LS II series engines together with those of the newly developed UEC52LSE engine. The LS II series is composed of eight types of engines from the 33LS II to 85LS II and covers the output range from 1,200 kW to 46,000 kW in the engine speed range from 54 rpm to 215 rpm. The longest operating hours of the UEC-LS II already exceeded 78,000 hours up to now and every engine has been operated under good condition.
They are highly reliable engines enjoying high appreciation in the reliability of combustion chambers as well as less wear ratio of piston rings and cylinder liners in particular. Fig.1 shows actual wear values of their piston rings and cylinder liners.
3. DEVELOPMENT CONCEPT
Table 1 shows principal particulars of the UEC52LSE. As shown in this table, the UEC52LSE type is a high output engine having higher brake mean effective pressure (Pme) by 10 percent and higher mean piston speed (Cm) by 5 percent than those of the previous UEC50LS II engine of the same class.
This type is able a high economy engine with the same specific fuel consumption as that of the UEC50LS II engine by increasing maximum cylinder pressure (Pmax) by 10%, irrespective of its higher output than that of the UEC-LS II engine.
In the development stage of the UEC-52LSE, high economy was pursued for all of ship owners, shipyards and engine manufactures.
Design emphasis was put on low fuel consumption; low after-sales service costs based on high reliability; ease of engine outfitting, maintenance, and maneuver; and fewer engine components. Taking account of measures for environmental issues which will become important in near future, this engine can adopt a water addition system which can reduce NOx-emission by some 50 percent from standard conditions. Thus, this engine can be said to be environmentally friendly.
* Mitsubishi Heavy Industries Ltd.
1-5-2 choume Marunouchi Chiyoda, Tokyo, 100-8315,