Development of the high-speed diesel engine 20V 8000 M71

摘要

In 2001, MTU introduced its 8,200 kW, four-stroke 20V 8000 M70 diesel engine for commercial marine applications onto the market. As a result of customer demand and the envisaged tightening of emission requirements, the 20V 8000 M71 was further developed and its power output increased to 9,100 kW. Development of the engine focused on low fuel consumption, improved ease of maintenance, a long service life and a wide performance map over the total speed range. Essential contributions to achieving these targets are provided by the Common-Rail fuel injection system with a rail pressure of 1800 bar known from the previous engine version as well as the proven concept of sequential turbocharging. As demonstrated in tests, engine operation without black and white-smoke is ensured throughout the entire performance map. The power increase was made possible essentially by further developing the single-stage supercharging and by a new combustion method. This way MTU succeeded in achieving low NO_x emissions and very low fuel consumption despite the higher engine performance. An iterative development process, during which the design, analytics and test departments cooperated closely, allowed targets to be achieved within a very short time. In addition to detailed analytical computations, extensive parameter studies were carried out on a single-cylinder engine. This paper inludes a description of those engine components which have been changed in comparison to the M70 version, and of their development. It also presents the experience gained from using the single-cylinder engine during the combustion development as well as the supercharging-system development. A discussion of the results of the PowerUnit endurance tests on the single-cylinder engine, the results from tests on a full-size engine and the customer-specific technical data is also included.