DIESEL ENGINES
DISCUSSION AT THE
DIESEL ENGINE LABORATORY
ROYAL DUTCH SHELL COMPANY AT DELFT
The Royal Dutch Shell laboratory at Delft is probably the only Diesel laboratory in the world that is equipped to solve fuel problems and operating problems of the larger marine-type Diesel engines. This laboratory has pioneered in combustion research in Diesel engines and is continuing to make significant contributions in this field. J.J. Broeze who is Director of the laboratory was absent during my visit but I had the opportunity to discuss the work with L.A. Pellatier, Assistant Director, B.J. Gravesteyn, in charge of the marine Diesel operations, and G. Wassenar, in charge of the automotive Diesel work. The marine Diesel laboratory uses a single cylinder Sulzer engine, having a piston diameter of 20 inches and a single Stock engine having a piston diameter of 22 inches, for the study of both fuel and lubricating problems in large engines. These problems are considerably different in the larger engines, in particular, the lubricating oil problems frequently required study on the full scale.
Considerable work has been done by Shell on the use of heavy fuel oils in Diesel engines. These heavier oils have been used in engines having speeds of 400-500 rpm. Oil viscosity of 180 seconds Saybolt furol has been used. In using the heavier oils it is extremely important to remove salt and reduce the ash content by centrifugation. It has been found that an ash content of .15%, or less, is essential. The purification system for a typical installation would consist of two DeLaval centrifuges in series, preceded by a purifier and clarifier to remove water and sediment.
The injection characteristics of different fuels are measured at the Shell laboratory in order to solve problems in combustion and other operating difficulties as related to the fuel used. In making these performance tests, the needle lift as a function of time is used as a simple criterion of performance and the Shell laboratories have developed a simple method of getting a point by point curve. The work on the automotive Diesel engines is not as active in the Shell laboratories as the work on marine Diesel engines, and for the most part, the automotive Diesel work is concerned with lubricating oil problems.