Fuel-gas supply/purge system for diesel engine

Abstract

The purpose of the present invention is to enable switching from fuel-gas operation to fuel-oil operation, without temporarily stopping a diesel engine in cases when, during fuel-gas operation in which a fuel gas is injected from gas injection valves, a gas injection valve fails while open and cannot close, and inert gas is to be used to purge the fuel gas that has accumulated in an accumulator, when switching from fuel-gas operation in which the fuel gas is injected from the gas injection valves, to fuel-oil operation in which a fuel oil is injected from fuel-oil injection valves. Accordingly, valves (82) set in a fully closed state when switching from fuel-gas operation to fuel-oil operation are provided to midpoints of fuel-gas supply pipes (66) which guide, to gas injection valves (61) provided so as to correspond to respective cylinders of a diesel engine, a fuel gas which has been guided from a fuel-gas supply source, and which has accumulated inside accumulators (65) provided so as to correspond to the respective cylinders of the diesel engine.

Description

technical field [0001] The present invention relates to a fuel gas supply / cleaning system applied to a diesel engine capable of combusting both fuel oil and fuel gas or fuel gas by high-pressure injection. Background technique [0002] As a fuel gas supply / cleaning system applied to a diesel engine capable of combusting both fuel oil and fuel gas by high-pressure injection, a configuration disclosed in Patent Document 1, for example, is known. [0003] Patent Document 1: Japanese Patent Laying-Open No. 9-209788 ( Figure 7 ) [0004] Here, the same as described in the above-mentioned Patent Document 1 Figure 7 The gas injection valve 61, gas gate valve 62, vent valve 63 and exhaust valve 64 corresponding to the gas injection valve 2, shut-off valve 28, discharge valve 30 and purge valve 32 are as follows Figure 6 Configure as shown, such as Figure 6 As shown, the gas gate valve 62 is the same as that described in the above-mentioned Patent Document 1 Figure 7 In the ca...

AI Technical Summary

Problems solved by technology

Thus, in Image 6 In the structure shown, there is the following problem: the diesel engine must be temporarily stopped, so that the combustion gas in the cylinder does not flow into the accumulator 65, described in the above-mentioned patent document 1 Figure 7 state in the discharge pipes 31, 35, and clean the reservoir 65 with inert gas, and then inject fuel oil from the fuel oil injection valve to restart the diesel engine

However, in the present invention, it is also necessary to Image 6 The solution to the problem with the same structure as shown is that, during the fuel gas operation in which fuel gas is injected from the gas injection valve 24, a malfunction occurs while the gas injection valve 24 is kept open and is not closed. When switching from a fuel gas operation in which fuel gas is injected from the gas injection valve 24 to a fuel oil operation in which fuel oil is injected from a fuel oil injection valve (not shown), the fuel gas accumulated in the accumulator 22 is purged with an inert gas In this case, it may not be possible to switch from fuel gas operation to fuel oil operation without temporarily stopping the diesel engine.

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