Marine diesel engine

Abstract

A marine diesel engine having superchargers, in which, when the superchargers are switched from single operation to parallel operation or from parallel operation to single operation, surging of a supercharger that is started up or stopped is prevented. The marine diesel engine has an exhaust pipe (L2) for connecting between an exhaust manifold (6) mounted on an engine body (2) and a turbine section (4a), a turbine inlet valve (10) connected to the middle of the exhaust pipe (L2), an air supply pipe (L4) for connecting between a compressor section (4b) and an air supply manifold (7) mounted on the engine body (2), a check valve (11) connected to the middle of the air supply pipe (L4) and becomes an open state when the exit pressure of the compressor section (4b) is not less than the exit pressure of a compressor (3b), an air release pipe (L9) having one end connected to the air supply pipe (L4) at its middle portion between the compressor section (4b) and the check valve (11), and an air release valve (12) connected to the middle of the air release pipe (L9).

Description

technical field [0001] The present invention relates to a marine diesel engine, and more particularly, to a marine diesel engine including a plurality of superchargers that boost the pressure of supply air using exhaust gas. Background technique [0002] As a sailing form of merchant ships, in order to reduce the fuel consumption of the main engine and to adjust the sailing schedule, some slow-down sailing is sometimes performed from the usual sailing speed. In this case, although it is necessary to reduce the load of the main engine from the usual sailing load for sailing, it is difficult to obtain a wide range of main engine load when only one supercharger is generally equipped. The most suitable supercharger efficiency. Therefore, by installing a plurality of superchargers and controlling the number of them to operate, the most suitable supercharger efficiency can be obtained in a wide range of main engine loads. Therefore, compared with the general case of only one supe...

AI Technical Summary

Problems solved by technology

[0004] However, in the marine diesel engine disclosed in the aforementioned Patent Document 1, if the valve b is opened when the No. 2 supercharger 2 is started, blower 1B (specifically, the ventilation chamber 3) of the No. 1 supercharger 1 When the blower 2B of the No. 2 supercharger 2 produces a backflow phenomenon, the No. 2 supercharger 2 cannot rotate (start) smoothly, and the No. 2 supercharger 2 has a problem of surge

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