| 摘要 |
PURPOSE:To speed up a tugboat in navigation without tugging another boat or ship, by increasing the rotational frequency of an engine in such a range that the mean effective pressure of the engine does not exceed the theoretical value. CONSTITUTION:The pitch of a fixed-picture propeller is set so that an engine should generate its maximum continuous output MCR at rotational frequency n1 set on the basis of the theoretical mean effective pressure of the engine, in the case C of work such as tugging a ship or the like. In navigation without tugging a ship or the like, a tugboat is run within the same region 1 as the case C until a predetermined boat speed is achieved at predetermined rotational frequency of the engine. When the engine has reached the set rotational frequency n1, the engine is reset at maximum rotational frequency n2 within such a range that the mean effective pressure of the engine does not exceed the theoretical value. As a result, said navigation is continued in a region II. In the case A of the navigation, the load is lower than in the case C of work and no extra motive power is needed, so that the output power of the engine can be positively heightened to speed up the tugboat as msuch as possible. |
