Method and device for controlling starting of gas engine
First Claim
1. A method of controlling starting of a gas engine in whichfuel gas is introduced via a fuel gas flow control valve to a charging air supply pipe to be mixed with the air and the mixture is controlled in its flow rate by a throttle valve and supplied to combustion chambers of the engine, wherein are provideda starting operation mode in which fuel gas flow is controlled by the fuel gas flow control valve based on actual mixture flow rate and adequate excess air ratio prescribed for each of detected values of operating conditions of the engine and then mixture flow is controlled by the throttle valve so that engine rotation speed approaches a target rotation speed, anda normal operation mode in which fuel gas flow is controlled by the fuel gas flow control valve so that engine rotation speed approaches the target rotation speed and then mixture flow rate is controlled by the throttle valve so that air fuel ratio of the mixture coincides with an adequate value prescribed for each of detected values of operating conditions of the gas engine with the fuel gas flow flowing at a commanded fuel gas flow rate,wherein a switchover rotation speed is predetermined which is a threshold value of engine rotation speed for the engine to be able to run self-reliably, andwherein the engine is controlled in the starting operation mode during engine rotation speed of from a prescribed initial rotation speed to a prescribed switchover rotation speed, and when the rotation speed rises to equal to or exceeds the prescribed switchover rotation speed, the control is switched to the normal operation mode.
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Accused Products
Abstract
A method and device for controlling starting of a gas engine is proposed which is superior in starting performance and improved in load responsivity while maintaining air fuel ratio control.
There are provided a starting operation mode in which fuel gas flow is controlled by the fuel gas flow control valve based on actual mixture flow rate and adequate excess air ratio prescribed for each of detected values of operating conditions of the engine and then mixture flow is controlled by the throttle valve so that engine rotation speed approaches a target rotation speed, and a normal operation mode in which fuel gas flow is controlled by the fuel gas flow control valve so that engine rotation speed approaches the target rotation speed and then mixture flow rate is controlled by the throttle valve so that air fuel ratio of the mixture coincides with an adequate value prescribed for each of detected values of operating conditions of the gas engine with the fuel gas flow flowing at the commanded fuel gas flow rate, and a switchover rotation speed is predetermined so that operation mode is switched from starting mode to normal mode when engine speed reaches the switchover rotation speed.
19 Citations
9 Claims
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1. A method of controlling starting of a gas engine in which
fuel gas is introduced via a fuel gas flow control valve to a charging air supply pipe to be mixed with the air and the mixture is controlled in its flow rate by a throttle valve and supplied to combustion chambers of the engine, wherein are provided a starting operation mode in which fuel gas flow is controlled by the fuel gas flow control valve based on actual mixture flow rate and adequate excess air ratio prescribed for each of detected values of operating conditions of the engine and then mixture flow is controlled by the throttle valve so that engine rotation speed approaches a target rotation speed, and a normal operation mode in which fuel gas flow is controlled by the fuel gas flow control valve so that engine rotation speed approaches the target rotation speed and then mixture flow rate is controlled by the throttle valve so that air fuel ratio of the mixture coincides with an adequate value prescribed for each of detected values of operating conditions of the gas engine with the fuel gas flow flowing at a commanded fuel gas flow rate, wherein a switchover rotation speed is predetermined which is a threshold value of engine rotation speed for the engine to be able to run self-reliably, and wherein the engine is controlled in the starting operation mode during engine rotation speed of from a prescribed initial rotation speed to a prescribed switchover rotation speed, and when the rotation speed rises to equal to or exceeds the prescribed switchover rotation speed, the control is switched to the normal operation mode.
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5. A starting control device for controlling starting of a gas engine in which fuel gas is introduced via a fuel gas flow control valve to a charging air supply pipe to be mixed with the air and the mixture is controlled in its flow rate by a throttle valve and supplied to combustion chambers of the engine, the engine being equipped with a rotation speed sensor for detecting engine rotation speed, an inlet pressure sensor for detecting mixture inlet pressure, an inlet temperature sensor for detecting mixture inlet temperature, and an engine control device for controlling engine operation in accordance with detected values of operating conditions of the engine, wherein the engine control device has a means to allow the fuel gas flow control valve to control fuel gas flow rate based on actual mixture flow rate detected engine rotation speed, inlet manifold pressure, and inlet manifold temperature and based on an adequate value of excess air ratio prescribed for each of detected values of operating conditions of the gas engine and a means to allow the throttle valve to control mixture flow rate so that engine rotation speed approaches a prescribed target rotation speed, thereby enabling the control device to perform engine operation in a starting operation mode, and
a means to allow the fuel gas flow control valve to control fuel gas flow rate so that engine rotation speed approaches a prescribed target rotation speed and a means to allow the throttle valve to control mixture flow rate so that excess air ratio of the mixture coincides with an adequate value prescribed for each of detected values of operating conditions of the gas engine with the fuel gas flow flowing at the controlled fuel gas flow rate, thereby enabling the control device to perform engine operation in a normal operation mode, wherein a switching means for switching over operation mode from one mode to the other mode is provided, and wherein a switchover rotation speed is predetermined which is a threshold value of engine rotation speed at which the engine can run self-reliantly, whereby the engine is controlled in the starting operation mode during engine rotation speed of from a prescribed initial rotation speed to a prescribed switchover rotation speed, and when the rotation speed rises to equal to or exceeds the prescribed switchover rotation speed, the control is switched to the normal operation mode.
Specification