The statement, 'can be run on two types of fuel', is an insufficient description of the possibilities of big, modern marine Diesel engines, since what is meant by the two types, are simply gas and liquid fuel. Here one can see, in which direction the modern container ships are being developed, namely, to be ready for the most variable possible future. Assuming that the respective tanks are fitted, it can even be switched over during the trip. The condition is: At least 5% of the fuel must be in liquid form.
The turbo-charging in a marine Diesel engine also functions differently than that of a truck. Not only that the turbocharger can weigh as much as two tons, there may also be several which are connected with each other. The speciality is, that there are adjustable guide-vanes (VTG-charger) which are not anchored to a fixed centre of rotation, but also that the rotary parts are so big, that when running, the blades can be evenly twisted.
Arranged in stages, the exhaust gas can, e.g., be guided first through the high pressure- and then through a low pressure turbine. Vice versa, the fresh air goes first through the low pressure- and then through the high pressure compressor. In the meantime, also for the truck sector, an unbelievable 6 bar of pressure is reached. Fast running four-stroke engines can thus achieve far more than 1000 kW per cylinder, reduce the NOX by roughly a quarter and achieve 170 g/kWh.
This would mean, that in theory, the modern truck with only 100kW of performance, could reach a speed of 100 km/h and would only be using just under 15 litres per 100 km. You can easily see: It can't manage this. If more kW is applies or it is driven more slowly, both of which are probable, the difference would be even greater. 12/14
Top of page
2001-2015 Copyright programs, texts, animations, pictures: H. Huppertz - E-Mail
Translator: Don Leslie - Email: email@example.com