JPH0524922U - Air-fuel ratio controller for auxiliary combustion chamber of gas engine - Google Patents

Abstract

(57) [Summary] [Object] A sub-combustion chamber air-fuel ratio control device for a sub-combustion chamber type gas engine capable of keeping the air-fuel ratio of the sub-combustion chamber within the combustible range of fuel. In a sub-combustion chamber type gas engine constituted by a main combustion chamber 1, a sub-combustion chamber 2 and an ignition plug 3, an output sensor 12 is provided on an engine output shaft and an exhaust temperature sensor 13 is provided on an exhaust manifold. Each sensor 1
The signals 2 and 13 are sent to the fuel flow control valve 14 which controls the amount of fuel additionally supplied to the auxiliary combustion chamber 2 via the orifice 5, the check valve 6 and the like. [Effect] Since the amount of the fuel additionally supplied to the auxiliary combustion chamber 2 can be automatically and appropriately controlled, the auxiliary combustion chamber 2 can be controlled.
The air-fuel ratio is maintained within the combustible range of the fuel to ensure that the auxiliary combustion chamber 2 is combusted, whereby the lean mixed gas in the main combustion chamber 1 can be completely and stably combusted.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a sub-combustion chamber air-fuel ratio control device for a sub-combustion chamber type gas engine, in which the air-fuel ratio of the sub-combustion chamber can be kept within a combustible range of fuel.

[0002]

[Prior Art]

Conventionally, it has been known that it is effective to operate at a lean air-fuel ratio as a means for reducing NO _x in a gas engine, and as one of the means, a sub-engine as shown in FIG. 2 is used. Combustion chamber gas engines have been put to practical use. In the gas engine, the air-fuel ratio is set to about 1.8 to 2.2 in the main combustion chamber 1, but since ignition by the spark plug 3 is difficult at this air-fuel ratio, the fuel control valve controlled by the governor 21. 4, the fuel is additionally supplied to the auxiliary combustion chamber 2 via the orifice 5, the check valve 6, etc., and the fuel concentration in the auxiliary combustion chamber 2 is increased to facilitate ignition of the auxiliary combustion chamber 2. The air-fuel ratio is used. The auxiliary combustion chamber 2 having an air-fuel ratio that facilitates ignition is ignited by a spark plug 3 and the flame thereof is guided to the main combustion chamber 1 to completely and reliably burn the lean mixed gas in the main combustion chamber 1. Normally, if the air-fuel ratio of the auxiliary combustion chamber 2 is not about 0.8 to 1.3, ignition becomes impossible and misfire will occur.

Conventionally, the air-fuel ratio of the gas entering the main combustion chamber 1 through the intake valve 7 from the fuel control valve 4 and the air-fuel ratio control device 11 is kept constant with respect to the fluctuation of the engine load. As for the air-fuel ratio of the sub-combustion chamber 2, the fuel control valve 4 and the air-fuel ratio control device 11 operate so as to keep the air-fuel ratio of the main combustion chamber 1 constant as described above, and the passage area of the orifice 5 and the main Since the passage area connecting the combustion chamber 1 and the auxiliary combustion chamber 2 is constant, it is difficult to maintain the air-fuel ratio of the auxiliary combustion chamber 2 at a value that facilitates ignition. That is, the air-fuel ratio of the main combustion chamber 1 is kept constant by the fuel control valve 4 and the air-fuel ratio control device 11, but the flow characteristics of the orifice 5 and the passage between the main combustion chamber 1 and the auxiliary combustion chamber 2 are maintained. This is because the amount of fuel additionally supplied through the orifice 5 deviates from the optimum air-fuel ratio range of 0.8 to 1.3 in the auxiliary combustion chamber 2 because the flow rate characteristics of No. 1 do not match.

[0004]

[Problems to be solved by the device]

 The present invention, in a gas engine of a sub-combustion chamber type, ensures the combustion of the sub-combustion chamber by maintaining the air-fuel ratio of the sub-combustion chamber within the combustible range of the fuel, and thereby The present invention intends to obtain an auxiliary combustion chamber air-fuel ratio control device for a gas engine, which can completely and stably burn a lean mixed gas.

[0005]

[Means for Solving the Problems]

 The present invention has been made in view of the above point of view, and in a gas engine of a sub-combustion chamber type configured by a main combustion chamber, a sub-combustion chamber, and a spark plug, an output sensor is provided on an engine output shaft and an exhaust gas is emitted. A temperature sensor is provided in each exhaust manifold, and a signal from each sensor is sent to a fuel flow control valve that controls the amount of fuel additionally supplied to the auxiliary combustion chamber through an orifice, a check valve, etc. It aims to provide a combustion chamber air-fuel ratio control device.

[0006]

[Action and Example]

 Hereinafter, the structure of one embodiment of the present invention will be described with reference to FIG. The sub-combustion chamber type gas engine is composed of a main combustion chamber 1, a sub-combustion chamber 2, and a spark plug 3. The fuel whose amount is adjusted by the fuel control valve 4 controlled by the governor 21 enters the main combustion chamber 1 through the intake valve 7. On the other hand, a part of the fuel exiting the fuel control valve 4 passes through the orifice 5 and is throttled to the required amount in the auxiliary combustion chamber 2 and enters the auxiliary combustion chamber 2. The fuel in the sub-combustion chamber 2 having an appropriate air-fuel ratio is ignited by the spark plug 3, and its flame spreads to the main combustion chamber 1 through the passage with the main combustion chamber 1, and thereby the main combustion chamber 1 A fuel having a lean air-fuel ratio of 1 is burned, and its pressure becomes an engine output by the piston 8, the connecting rod 9, and the crankshaft 10.

In order to obtain stable combustion, the output sensor 12 is provided on the engine output shaft, and the exhaust temperature sensor 13 is provided on the exhaust manifold. The sensors 12 and 13 detect changes in the engine output and changes in the exhaust temperature that appear when combustion in the main combustion chamber 1 becomes unstable, and the signals are sent via the orifice 5, the check valve 6, etc. The amount of fuel additionally supplied to the combustion chamber 2 is sent to a fuel flow rate control valve 14, which controls the amount of fuel additionally supplied to the auxiliary combustion chamber 2.

[0008]

[Effect of the device]

 According to the present invention, as described above, in the auxiliary combustion chamber type gas engine constituted by the main combustion chamber 1, the auxiliary combustion chamber 2, and the spark plug 3, the output sensor 12 is the engine output shaft and the exhaust temperature sensor 13 is the exhaust gas. The signals of the respective sensors 12, 13 are respectively provided in the manifolds and sent to the fuel flow rate control valve 14 for controlling the amount of the fuel additionally supplied to the auxiliary combustion chamber 2 through the orifice 5, the check valve 6 and the like, As a result, the amount of the fuel additionally supplied to the auxiliary combustion chamber 2 is automatically and appropriately controlled, so that the air-fuel ratio of the auxiliary combustion chamber 2 is kept within the combustible range of the fuel to prevent the auxiliary combustion. The combustion in the chamber 2 is ensured so that the lean mixed gas in the main combustion chamber 1 can be completely and stably combusted.

[Brief description of drawings]

FIG. 1 is a schematic circuit configuration diagram showing a configuration of an embodiment of the present invention.

FIG. 2 is a schematic circuit configuration diagram showing a conventional example.

[Explanation of symbols]

 1 Main Combustion Chamber 2 Sub Combustion Chamber 3 Spark Plug 5 Orifice 6 Check Valve 12 Output Sensor 13 Exhaust Temperature Sensor 14 Fuel Flow Control Valve

Claims (1)

[Scope of utility model registration request] 1. A main combustion chamber 1, a sub combustion chamber 2, and a spark plug 3
In the sub-combustion chamber type gas engine configured by, the output sensor 12 is provided on the engine output shaft, the exhaust temperature sensor 13 is provided on the exhaust manifold, and the signals of the sensors 12 and 13 are supplied to the orifice 5 and the check valve 6 respectively. A sub-combustion chamber air-fuel ratio control device for a gas engine, characterized in that the fuel is supplied to a fuel flow rate control valve 14 for controlling the amount of fuel additionally supplied to the sub-combustion chamber 2 via the above.