The Intelligent Engine: Prospects and Experience from Service
The paper deals with the development of computer controlled low speed crosshead diesel engines and the application prospects for such 'Intelligent Engines'. The main development goals are enhanced reliability, reduced operational costs and great operational flexibility with regard to output and emissions. The concept is outlined and the paper describes the fuel injection and exhaust valve actuation systems, the electronic control system, the cylinder pressure measuring system and the cylinder lubrication system. Examples of the flexibility of the injection system are given.
A full-scale service test of such a system on all cylinders of the 6L60MC main engine of the 37,500 dwt Norwegian chemical carrier M/T Bow Cecil will start mid-2000. The design of the systems is outlined, followed by a description of the experience with those parts of the new system which are already in service. Finally, the first commercial orders for 'intelligent engines', four 7S60ME-C engines, will be dealt with.
As outlined in a number of papers during the last decade, it is our firm conviction that the use of electronic software and hardware for marine engines will increase tremendously in the future.
We are convinced that, when properly used, this will contribute to improving engine reliability and reducing maintenance as well as total running costs. This is why we established a separate Electronics & Software Development Department some five years ago, with hardware and software expertise and the capacity to do professional development work. This investment in development capacity was meant not only to further the ongoing development of our 'Intelligent Engine' but certainly also to promote the development of systems that can be used to enhance the reliability of the existing engine series, and to facilitate new applications.
The Intelligent Engine concept has been described in a number of publications such as , ,  and . Thus, the present paper will merely outline the concept and then concentrate on giving a progress report of the development of this concept as well as experience obtained with the systems in service.
2. THE INTELLIGENT ENGINE CONCEPT
The aim of this long-term development is to create an engine generation that is extremely reliable and, at the same time, has a high degree of flexibility in terms of operating modesfor example fuel economy-optimised or emission-optimised.
To meet the operational flexibility target, it is necessary to have great flexibility in the operation of at least the fuel injection and exhaust valve systems. Achieving this objective with cam-driven units would require substantial mechanical complexity that would hardly contribute to engine reliability.
To meet the reliability target, it is necessary to generate a system that can protect the engine from damage caused by overload, lack of maintenance, maladjustment, etc. A condition monitoring system must be used to evaluate the general engine condition so as to maintain the engine performance and keep its operating parameters within the prescribed limits.
2.1 System description
The above implies that a new type of drive is needed for the injection pumps and the exhaust valves and that an electronic control and monitoring system will also be called for. The concept, which caters for these needs, is illustrated in Fig.1.
The upper part shows the Operating Modes which may be selected from the bridge control system or by the intelligent engine's own control system. The control system contains data for optimal operation in these modes, which consist of a number of single modes corresponding, for instance, to different engine loads and different emission requirements.
The fuel-economy modes and emission-controlled modes (some of which may incorporate the use of an SCR catalytic clean-up system) are selected from the bridge. In contrast, the optimal reversing/crash stop modes are selected by the electronic control system itself when the bridge control system requests the engine to carry out the corresponding operation.
* MAN B&W Diesel A/S, Research & Development,
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** MAN B&W Diesel A/S, Marketing & Sales