Investigation of thermal and mechanical cylinder liner loads and its modernization in 5L50MC МАN-В&W diesel engine

Authors: V.N. Kucherov,  M.V. Florianskaya

 

Abstract

Extensive wear of cylinder liners, piston rings and grooves of the early models of various size L-MC series engines has been documented in the attempt to operate them at the power output close or exceeding the values recommended by the manufacturer. The rings mainly experienced extensive wear, loss of elasticity (collapse) and fractures. The majority of faults have occurred in L42MC and L50MC engines with the thickest cylinder liner wall at the TDC ofthe upper piston ring (61 mm in L50MC position) and, consequently, higher thermal resistance. The research has shown inadmissibly high local temperatures during operation at the TDC of the upper piston ring at the set load of 0,82 of the nominal value. The liner's temperature field is asymmetrical and maximum at the exhaust side. As a result, the piston groove wear speed is higher at the exhaust side and lower at the maneuver side (larboard). The calculation of temperature and mechanical tensions has confirmed the possibility of modernization of the liner's upper part through the eccentric grooving at the exhaust side to equalize the temperature field ofthe liner. Such modernization allows to lessen the liner's thermal load at the exhaust side corresponding with the engine's load cutting by 15 % of the output power, and, with the symmetrical temperature field, to ensure the reliable operation of the engine's cylinders at the set power output. The purpose of the conducted research is to analyze the operational conditions of the cylinder-piston group of L-MC engines, causes and modes of failures and faults in its elements, as well as the development of designing and possible operational measures for enhancement of power and resource characteristics of the engines of this group.

 

Keywords: diesel engine, cylinder liners, wear, investigation, thermal measurement, mechanical stress, modernization, tests

 

References

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About authors

V.N. Kucherov - PhD, professor, G.I. Nevelskoy Maritime State University, Vladivostok, e-mail: Nadezkin@msun.ru 

M.V. Florianskaya - PhD, professor, G.I. Nevelskoy Maritime State University, Vladivostok, e-mail: flormary@yandex.ru

 

For citation: V.N. Kucherov, M.V. Florianskaya. Investigation of thermal and mechanical cylinder liner loads and its modernization in 5L50MC МАN-В&W diesel engine. Research Bulletin by Russian Maritime Register of Shipping. 2018, No. 52/53, pp. 88-96.

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UDC:  621.43:629.5
Pages:  88-96