JPH09195806A - Stopping device of diesel engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To allow a sudden stop of the engine in an overspeed condition, by providing a switch valve on a nitrogen gas conduit, as well as connecting a nitrogen gas feeding source and the intake duct of the engine by this nitrogen gas conduit. SOLUTION: A nitrogen gas tank 22 in which a nitrogen gas pressurized to a specific pressure is sealed is provided. And it is connected to the suction duct 4 of a diesel engine 7 through a nitrogen gas pipe 21, while a solenoid valve 23 is provided to the pipe line 21. And when the diesel engine 7 is made in an overspeed condition, and an overspeed detecting means detects it, in the diesel engine 7 operation condition, the solenoid valve 23 is opened instantly, the nitrogen gas in the nitrogen tank 22 is mixed to the intake air in the intake duct 4 through the nitrogen gas pipe 21, and it is sucked in the cylinder of the diesel engine 7. Consequently, the inside of the cylinder of the diesel engine 7 is made in a sudden oxygen short condition, to make the fuel incombustible, and the diesel engine 7 is stopped suddenly.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sudden stop device for a diesel engine at overspeed.

[0002]

2. Description of the Related Art FIG. 3 shows a schematic structure of a diesel power generator. In FIG. 3, 7 is a diesel engine,
Reference numeral 8 is a generator directly connected to the diesel engine through a shaft coupling 15, 4 is an intake duct, 1 is an intake silencer provided at the inlet of the intake duct, 3 is an air cooler, and 2 is a supercharger. , 6 is an exhaust collecting pipe, 5 is an exhaust duct, and 9 is a fuel supply pipe.

In the above diesel power generator, the engine 7
Exhaust gas discharged from is collected in the exhaust collecting pipe 6,
After driving the supercharger 2, it is discharged from the exhaust duct 5 to the outside.

On the other hand, after the intake air is silenced by the intake silencer 1, the intake air passes through the intake duct 4 and enters the supercharger 2, where it is pressurized and pressure-increased. It is cooled by and sucked into the cylinder of the engine 7.

Fuel is sent to a fuel injection pump (not shown) in a fuel supply pipe 9 by a fuel supply pump (not shown), where it is pressurized to a high pressure and injected into a fuel injection valve (not shown).
Is injected into the cylinder.

In the above diesel engine, when the engine becomes over-speed (over-rotation), the fuel cutoff valve 10 installed in the fuel supply line 9 is rapidly closed and the fuel supply pump is stopped. , The supply of fuel to the engine 7 is cut off.

In addition to the above-mentioned means, when overspeed of the engine 7 is detected, compressed air is blown into the fuel supply pipe 9 instantaneously to blow off the fuel in the pipe (blow back to the fuel tank etc.). Also provides means for shutting off fuel supply to the engine 7.

[0008]

In the above diesel engine, as described above, when the engine 7 becomes overspeed, this is detected and the fuel cutoff valve 10 is suddenly closed. Even after the shutoff valve 10 is closed, the fuel remains in the fuel oil pipeline on the engine 7 side of the shutoff valve 10 and there is a residual pressure.

Therefore, the residual fuel is sucked into the fuel injection pump, pressurized, and injected into the cylinder from the fuel injection valve. Even if the fuel cutoff valve 10 is closed as described above, the fuel is burned for a while. However, it will be difficult to stop the engine suddenly.

Further, with the means for blowing off the compressed air to the fuel supply conduit 9, it is difficult to completely remove the fuel in the fuel supply conduit 9 in a short time by blowing the compressed air. Also in this case, it is difficult to stop the engine 7 suddenly.

It is an object of the present invention to provide a diesel engine stopping device which makes it possible to suddenly stop the engine at overspeed by cutting off the supply of oxygen to the engine.

[0012]

Means for Solving the Problems The present invention is intended to solve the above-mentioned problems, and the gist of the present invention is to shut down the engine by turning off oxygen among the three elements of combustion. The first means is
A stop device for a diesel engine, characterized in that a nitrogen gas supply source and an intake duct of the engine are connected by a nitrogen gas pipe, and an opening / closing valve for opening / closing the nitrogen gas pipe is provided.

According to this means, when the overspeed of the engine is detected, the opening / closing valve provided in the nitrogen gas pipeline opens the gas pipeline. As a result, the nitrogen gas from the nitrogen gas supply source flows into the intake duct and is sucked into the cylinder of the engine, the cylinder is deficient in oxygen, combustion is stopped, and the engine is suddenly stopped. Therefore, unlike the conventional one, the residual fuel does not make it difficult to stop suddenly, and the engine can be stopped quickly.

A second means of the present invention is to connect a recirculation gas duct connecting an exhaust duct downstream of the supercharger with an intake duct, a recirculation damper for opening / closing the recirculation gas duct, and opening / closing the intake duct and the exhaust duct, respectively. A stop device for a diesel engine, comprising an intake damper and an exhaust damper.

According to such means, when the overspeed of the engine is detected, the recirculation damper is opened, the intake damper and the exhaust damper are closed, and the exhaust gas having a low oxygen concentration passes through the intake duct into the cylinder. Recirculation causes a shortage of oxygen in the cylinder, combustion is stopped, and the engine is suddenly stopped. In this case, since the exhaust gas is recirculated, no special equipment such as the nitrogen gas supply source in the first means is required and the cost is reduced.

[0016]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 shows a configuration diagram of a diesel engine stop device in a diesel power generator according to a first embodiment of the present invention.

In FIG. 1, 7 is a diesel engine, 8 is a generator directly connected to the diesel engine via a shaft coupling 15, 4 is an intake duct, and 1 is an intake silencer provided at the inlet of the intake duct. 3 is an air cooler, 2 is a supercharger, 6
Is an exhaust collecting pipe, 5 is an exhaust duct, and 9 is a fuel supply pipe.

In the above diesel generator, the engine 7
The exhaust gas discharged from the exhaust gas is collected in the exhaust collecting pipe 6 to drive the supercharger 2 and then discharged from the exhaust duct 5 to the outside.

On the other hand, the intake air is silenced by the intake silencer 1 and then enters the supercharger 2 through the intake duct 4 where it is pressurized to raise and raise the temperature, and the air cooler 3 It is cooled by and sucked into the cylinder of the engine 7.

Further, the fuel is sent to the fuel injection pump (not shown) in the fuel supply pipe 9 by the fuel supply pump (not shown), where it is pressurized to a high pressure to be injected into the fuel injection valve (not shown).
Is injected into the cylinder. The above configuration is similar to the conventional configuration shown in FIG.

Reference numeral 22 denotes a nitrogen tank in which nitrogen gas pressurized to a predetermined pressure is sealed, and the nitrogen tank 22 is connected to the intake duct 4 of the engine through a nitrogen gas pipe 21. Reference numeral 23 is a solenoid valve that controls the opening and closing of the nitrogen gas pipe 21, and the solenoid valve 23 opens and closes the nitrogen gas pipe 21 by a detection signal from a detection means (not shown) that detects the overspeed of the engine 7. It is supposed to do.

When the engine 7 is in an overspeed state during operation of the diesel engine constructed as described above, an overspeed detecting means (not shown) detects this and sends a detection signal to the solenoid valve 23. The solenoid valve 23 is
Upon receiving the detection signal, the nitrogen tank 22 is instantly opened.
The nitrogen gas therein passes through the nitrogen gas pipe 21 and mixes with the intake air in the intake duct 4, and is sucked into the cylinder of the engine 7.

As a result, the cylinder of the engine 7 suddenly becomes deficient in oxygen, the fuel injected into the cylinder by the fuel injection valve (not shown) becomes incombustible, and the engine 7 is suddenly stopped.

In this embodiment, a fuel cutoff valve 10 similar to the conventional one shown in FIG. 3 may be provided, and this stop means by nitrogen gas may be used together.

FIG. 2 shows a second embodiment of the present invention. In FIG. 2, 19 is a recirculation gas duct that connects the exhaust duct 5 downstream of the supercharger 2 and the intake duct 4 upstream of the supercharger 2, and 12 is a recirculation damper that opens and closes the flow path in the recirculation gas duct 19. Further, the intake duct 4 is provided with an intake damper 13 for opening and closing the flow path thereof, and the exhaust duct 5 is provided with an exhaust damper 11 for opening and closing the flow path thereof. Other configurations are the same as those of the first embodiment shown in FIG.

When the diesel engine shown in FIG. 2 is in operation, when the overspeed detecting means similar to that of the first embodiment detects the overspeed of the engine 7, the control and operation signals from the control device (not shown) cause an instantaneous change. The recirculation damper 12 is opened, the intake damper 13 is closed, and the exhaust damper 1
1 is closed.

As a result, the supply of the intake air to the intake duct 4 is cut off, and the exhaust gas with a low oxygen concentration in the exhaust duct 5 is completely recirculated to the intake duct 4 through the recirculation gas duct 19 and the engine 7 is exhausted. The engine 7 is sucked into the cylinder, oxygen in the cylinder becomes insufficient, and the engine 7 is suddenly stopped.
In this case, since the exhaust gas is recirculated upstream of the supercharger 2, surging does not occur in the supercharger 2. During normal operation, the recirculation gas damper 19 is closed, and the intake damper 13 and the exhaust damper 11 are open. Note that the fuel cutoff valve 10 may be provided in this embodiment as well.

[0028]

The present invention is configured as described above.
According to the invention of claim 1, since the nitrogen gas is supplied into the cylinder at the same time when the overspeed is detected, there is no problem that the sudden stop of the engine becomes difficult due to the residual fuel unlike the conventional one, and the engine is instantaneously stopped. It can be stopped quickly and reliably.

Further, according to the invention of claim 2, since the exhaust gas is recirculated into the cylinder, a special device as in claim 1 is not required, and the engine can be suddenly stopped with a low cost device. It will be possible.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a diesel engine stop device according to a first embodiment of the present invention.

FIG. 2 is an equivalent view of FIG. 1 showing a second embodiment of the present invention.

FIG. 3 is a corresponding view of FIG. 1 showing a conventional diesel engine stop device.

[Explanation of symbols]

 2 Supercharger 4 Intake duct 5 Intake duct 7 Diesel engine 11 Exhaust damper 12 Recirculation damper 13 Intake damper 19 Recirculation gas duct 21 Nitrogen gas pipe 22 Nitrogen tank 23 Solenoid valve

Claims (2)

[Claims] 1. A diesel engine characterized in that a nitrogen gas supply source and an intake duct of the engine are connected by a nitrogen gas pipe, and an opening / closing valve for opening and closing the nitrogen gas pipe is provided in the nitrogen gas pipe. Stop device. 2. A recirculation gas duct that connects an exhaust duct and an intake duct downstream of the supercharger, a recirculation damper that opens and closes the recirculation gas duct, and an intake damper and an exhaust damper that open and close the intake duct and the exhaust duct, respectively. A stop device for a diesel engine characterized by the following.