KR101088887B1 - Method for controlling starting performance using continuous controlling fuel quantity - Google Patents

Abstract

PURPOSE: A method for controlling starting performance using continuous controlling fuel quantity is provided to improve reliability of an engine by smoothly performing starting of an engine. CONSTITUTION: A method for controlling starting performance using continuous controlling fuel quantity comprises next steps. An air-fuel ratio sensor is turned on(S20). The fuel amount multiplying the fuel amount factor of the engine in the starting basis fuel supply-amount is supplied to the engine(S30). If the engine starts up, the engine is driven by applying a fuel amount factor. If the engine does not start, the fuel amount factor is gradually increase or decrease as a setting rate(S50). The reset fuel amount factor is applied to perform the engine starting. If the engine is started, the engine is driven by applying the reset fuel amount factor.

Description

TECHNICAL FOR CONTROLLING STARTING PERFORMANCE USING CONTINUOUS CONTROLLING FUEL QUANTITY}

The present invention relates to a start control method of an engine for power generation through continuous fuel amount control to improve engine startability by using continuous fuel amount control in an engine using a variable composition fuel such as biomass fuel and waste fuel.

In general, gas fuel produced from biomass or waste (hereinafter referred to as 'waste gas fuel') is used as a fuel of a power generation system using an internal combustion engine engine.

Waste gas-based power generation engines are mainly used as conventional gas or LPG fueled commercial gas engine as it is, or partially modified.

However, unlike natural gas or liquefied petroleum gas, waste gas fuel may vary in composition of waste gas fuel depending on the state or type of waste as well as the gas production process. Therefore, in an engine using waste gas fuel, a problem arises in starting the engine because the state of the fuel cannot be known in advance and an accurate ratio of air and fuel (fuel ratio) cannot be determined.

In order to solve this problem, there is a case where a mixed engine using diesel as an ignition source is sometimes applied.

Honso engines are retrofits of existing diesel-fueled diesel engines. In other words, Honso engines use a diesel injection of diesel fuel at the end of the compression of the piston, and the diesel fuel is combusted to become a powerful source of ignition. It is a method of stably burning a mixed gas of gas and air.

Honso engines produce stable combustion even when the ratio of air and waste gas is not adequate, but it is a major cause of deterioration of profitability of power generation system using waste gas because of the cost of diesel fuel.

On the other hand, an electric combustion engine using only waste gas as a fuel uses an electric spark plug as an ignition source. However, the electric spark generated from the spark plug has a small amount of energy, so that misfire occurs when the air-fuel ratio is not appropriate. Therefore, the burner engine using only waste gas as fuel should be controlled so that the air-fuel ratio is always maintained at an appropriate level. To this end, it is essential for the burner engine to apply an air-fuel ratio sensor or an oxygen sensor to check whether a fuel system that supplies an accurate amount of fuel and an appropriate air-fuel ratio is maintained. However, it is not possible to supply the exact amount of fuel in the fuel system because the waste gas varies depending on the state or type of waste as well as the gas production process. In particular, since the air-fuel ratio sensor or the oxygen sensor cannot be used at the start-up, a problem that often does not occur because the air-fuel ratio that can be burned cannot be implemented.

This problem of poor start-up causes distrust of the power generation system using waste and is the biggest cause of the failure of smooth distribution of the waste power generation system. In order to solve the global energy issue and carbon emission limitation problem, biomass and waste energy is essential, and in order to expand its supply, it is necessary to solve the start-up problem of waste power generation system.

An embodiment of the present invention is to provide a start control method of the engine for power generation through the continuous fuel amount control that can be started smoothly even if the composition of the fuel in the engine using biomass or waste as fuel.

One embodiment of the present invention is a method for controlling the driving of a power generation engine using a variable composition fuel, comprising the steps of: (a) activating an air-fuel ratio sensor; Supplying the engine with a fuel amount multiplied by a starting basic fuel amount, (c) starting the engine using the supplied fuel amount, and (d) when the engine starts, Applying the engine to drive the engine; (e) if the engine does not start, (c) continuously reducing or increasing the fuel amount factor to reset the fuel amount factor; and (f) applying the reset fuel amount factor. (G) driving the engine by applying the fuel amount factor reset in step (e) if the engine is started in step (f), and (h) After repeating steps (e) and (f) for a time, if the engine does not start, the engine is stopped and the air-fuel ratio is checked to determine the decrease or increase of the fuel amount factor.

(e) step (e1) through the sensing signal of the air-fuel ratio sensor, continuously reducing the fuel amount factor for the set time when the oxygen concentration of the exhaust gas is rich, and (e2) through the sensing signal of the air-fuel ratio sensor The method may include continuously increasing the fuel amount factor for a predetermined time when the oxygen concentration of the exhaust gas is lean.

The determination of the rich or lean state of the exhaust gas may be determined based on the oxygen concentration contained in the exhaust gas in the theoretical air-fuel ratio state.

In the step (e1), it is possible to reduce the fuel amount factor in unit second intervals for a set time. In the step (e2), it is possible to increase the fuel amount factor in unit second intervals for a set time. The preset time may be less than 10 seconds.

In step (e1), the fuel quantity factor can be continuously reduced in the range of more than 0% and less than 50%. In step (e2), the fuel quantity factor can be continuously increased in the range of more than 0% and less than 50%.

The starting basic fuel amount may be a fuel amount corresponding to a theoretical air fuel ratio of the engine.

The activation of the air-fuel ratio sensor can be activated by supplying power by turning on the start key of the engine.

According to an embodiment of the present invention, the engine is started smoothly even if the composition of the fuel is changed in the engine using biomass or waste as fuel, thereby smoothly starting the engine after the engine is manufactured for the first time, thereby improving the reliability of the engine. This is possible.

1 is a flowchart schematically illustrating a start control method of a power generation engine through continuous fuel amount control according to an embodiment of the present invention.
2 is a block diagram schematically illustrating an engine, an air-fuel ratio sensor, and an electronic controller according to an embodiment of the present invention.

Hereinafter, a start control method of an engine for power generation through continuous fuel amount control according to embodiments of the present invention will be described in detail with reference to the accompanying drawings. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. It is provided to let you know.

The engine described below is an internal-combustion engine that combusts a combustion-air mixture. The internal combustion engine of the present embodiment can be applied to an engine used in a power generation system. However, the engine of this embodiment is not limited to being used in power generation systems, but can be applied to engines of various uses using waste and biomass gas fuels. Biomass fuel refers to fuels such as methane, ethanol and hydrogen produced by pyrolysis or fermentation of living organisms.

The engine applied in the embodiment of the present invention is intended for an unused engine in the initial state in which no starting operation is started after it is manufactured. That is, the fuel supplied to the engine for the first time is the fuel supplied to the engine in step S20 described later.

1 is a flowchart schematically illustrating a start control method of a power generation engine through continuous fuel amount control according to an embodiment of the present invention, and FIG. 2 is an engine and an air-fuel ratio sensor and electronic control according to an embodiment of the present invention. A block diagram schematically showing the device. Hereinafter, a start control method of an engine through fuel amount control according to an embodiment of the present invention will be described with reference to FIGS. 1 and 2.

First, by operating the engine start key (ON) to supply power to the engine (S10).

Then, the air-fuel ratio sensor 30 of the engine 10 is activated using the power supplied in step S10 (S20). The air-fuel ratio sensor 30 is a sensor for detecting the oxygen concentration contained in the exhaust gas. In this embodiment, by using the method of early activation of the air-fuel ratio sensor 30 to measure the oxygen concentration of the exhaust gas, it is possible to smoothly control the startability according to the fuel composition.

Next, when it is determined in step S20 that the air-fuel ratio sensor 30 is activated (ON), the fuel amount factor (Factor_1) initially stored in the electronic control unit (ECU) 20 after the engine 10 is manufactured, the fuel amount for driving the engine. It is determined as a factor and input to the electronic control unit ECU 20 (S21).

Then, the fuel amount obtained by multiplying the fuel amount factor Factor_1 by the starting basic fuel supply amount is supplied to the engine (S30). Here, the starting basic fuel supply amount is the amount of fuel supplied to the engine in the theoretical air-fuel ratio state. Therefore, in order to supply fuel to the engine with the starting basic fuel supply amount in step S30, the initial value of the fuel amount factor is 1.0.

Next, the ignition switch of the engine 10 is turned on using the fuel supplied in step S30 (S40), and it is determined whether the engine is started on (S50).

Subsequently, when it is determined that the engine is started in step S50, the fuel amount factor Factor_1 of step S21 is determined as a factor for driving the engine and the engine is driven (S110). Therefore, if the start is smoothly performed in step S50, the composition of the fuel supplied to the engine is the same as the composition of the fuel initially stored in the electronic controller 20, and the engine is driven using the amount of fuel set in step S30. If the start is not smoothly performed in step S50, it is determined that the composition of the fuel is changed in the state initially stored in the electronic control apparatus 20, and the steps to be described later are sequentially performed.

If it is determined that the engine is not started in step S50 stops the engine start operation (S60).

Next, by determining the output signal of the air-fuel ratio sensor 30, it is determined whether the oxygen concentration contained in the exhaust gas is lean or rich (S70). The criteria for determination of lean or rich oxygen concentration contained in the exhaust gas is based on the oxygen concentration contained in the exhaust gas in a theoretical air-fuel ratio state. That is, in step S70, if the concentration of oxygen contained in the exhaust gas is higher than the oxygen concentration in the theoretical air-fuel ratio state, it is determined as rich, and if the concentration of oxygen contained in the exhaust gas is below the oxygen concentration in the theoretical air-fuel ratio state, it is determined as lean.

Next, when it is determined that the oxygen concentration contained in the exhaust gas is rich through the output signal of the air-fuel ratio sensor 30 in step S70, the fuel amount factor of step S30 is continuously reduced and reset (S80). Here, the fuel amount factor may be continuously reduced in unit second intervals for a time of less than 10 seconds. This is a reduction time in consideration of the startup time of step S82 described later.

Subsequently, the fuel supplied to the engine is continuously reduced by multiplying the starting fuel amount of step S30 by the fuel amount factor reduced in step S80 (S81). Here, the continuous reduction of the fuel supply can be continuously reduced in the range of more than 0% and less than 50% based on the starting basic fuel amount of the step S30.

Next, the engine is continuously started for a predetermined time in the process of continuously changing the fuel amount factor at step S80 to determine whether the engine is started (S82). In this embodiment, the starting operation time of the engine may be determined to be less than 10 seconds. In other words, in step S82, the engine start operation is continuously performed for a period of less than 10 seconds while determining whether the engine is started while continuously reducing the engine fuel supply amount from 0% to 50% or less based on the starting basic fuel amount. will be.

In this case, if the engine is not started at step S82, it is determined whether the engine start time is less than 10 seconds (S83), and if the engine start time is within 10 seconds, the step S80 of continuously reducing the fuel amount factor is continuously performed. When the engine start time is determined to be 10 seconds or more, the engine moves to step S60 to stop the engine, and the output signal of the air-fuel ratio sensor 30 is determined again in step S70 to determine whether the fuel amount factor is decreased or increased.

When the engine starts normally in step S82, the fuel amount is derived by multiplying the reduced fuel amount factor Factor_1 at the time when the engine is started by the starting reference fuel amount in step S30 (S100).

Subsequently, engine driving is performed using the fuel amount derived in step S100 (S110).

Hereinafter, a method of determining a value in which the fuel amount factor is continuously reduced in step S80 will be described in more detail by using the following formula.

[Equation 1]

Factor = Factor × (1-α × Tsec / 10sec)

Factor: Fuel amount factor, α: 0.5, Tsec: Startup time

As described above, in step S80, when the start time Tsec is changed for 0 to 10 seconds, the fuel amount factor is continuously changed in a range not exceeding 0.5. Therefore, by multiplying the determined fuel amount factor in the step S81 by the starting base fuel amount in step S81, the amount of change in the fuel amount can be continuously reduced in the range of more than 0% and 50% or less based on the starting base fuel amount.

 On the other hand, if it is determined in step S70 that the oxygen concentration of the exhaust gas is lean through the output signal of the air-fuel ratio sensor 30, the fuel quantity factor of step S30 is continuously increased and reset (S90). Here, the fuel amount factor may be continuously increased in unit second intervals for a time within 10 seconds. This is an increase time considering the startup time of the step S92 described later.

Subsequently, the fuel supplied to the engine is continuously increased by multiplying the starting fuel amount of the step S30 by the fuel amount factor increased in the step S90 (S91). Here, the continuous increase in the fuel supply can be continuously increased in the range of more than 0% and less than 50% based on the starting basic fuel amount in step S30.

Next, the engine is continuously started for a predetermined time in the process of continuously increasing the fuel amount factor in step S90 to determine whether the engine is started (S92). In this embodiment, the starting operation time of the engine may be determined to be less than 10 seconds. That is, in step S92, the engine start operation is continuously performed for a period of less than 10 seconds while determining whether the engine is started while continuously increasing the engine fuel supply amount from 0% to 50% or less based on the starting basic fuel amount. will be.

In this case, if the engine is not started in step S92, it is determined whether the start time is less than 10 seconds (S93), and if the start time is within 10 seconds, step S90 is performed to continuously increase the fuel amount factor. When the start time is determined to be 10 seconds or more, the engine moves to step S60 to stop the engine, and the output signal of the air-fuel ratio sensor 30 is determined again in step S70 to determine whether the fuel amount factor decreases or increases.

When the engine starts normally in step S92, the fuel amount is derived by multiplying the increased fuel amount factor Factor_1 at the time when the engine is started by the starting reference fuel amount in step S30 (S100).

Subsequently, engine driving is performed using the fuel amount derived in step S100 (S110).

Hereinafter, a method of determining a value in which the fuel amount factor is continuously increased in step S90 will be described in more detail by using the following formula.

[Equation 2]

Factor = Factor × (1 + α × Tsec / 10 sec)

Factor: Fuel amount factor, α: 0.5, Tsec: Startup time

As described above, in step S90, when the start time Tsec is changed for 0 to 10 seconds, the fuel amount factor is continuously changed in a range not exceeding 1.5. Accordingly, by multiplying the determined fuel amount factor by the starting base fuel amount in step S91 in step S90, the amount of change in fuel amount may be continuously increased in a range of more than 0% and 50% or less based on the starting base fuel amount.

In this way, in steps S82 and S92, the amount of fuel supplied to the engine at the time of engine start-up is sensed, so that the fuel supply amount to be started even in a state where the composition of the fuel is changed can be accurately determined. Therefore, the engine is driven by using the fuel amount derived through the fuel amount factor determined in steps S82 and S92 at the time of starting the engine to be performed later, so that a smooth start can be made even if the fuel composition is changed.

The present invention has been described above with reference to the embodiments shown in the drawings. However, the present invention is not limited thereto, and various modifications or other embodiments falling within the scope equivalent to the present invention are possible by those skilled in the art.

10 Engine 20 Fuel consumption sensor
30 ... ECU

Claims (10)

In the method of controlling the drive of the engine for power generation using a variable composition fuel,
(a) activating the air-fuel ratio sensor;
(b) supplying a fuel amount to the engine by multiplying a starting amount of fuel by a fuel amount factor initially input to the electronic control apparatus of the engine;
(c) starting an engine using the supplied fuel amount;
(d) driving the engine by applying the fuel amount factor when the engine is started;
(e) if the engine does not start, resetting the fuel amount factor by continuously decreasing or increasing the fuel amount factor;
(f) applying the reset fuel amount factor to start an engine; And
(g) if the engine is started in step (f), driving the engine by applying the fuel amount factor reset in step (e);
(h) after repeating steps (e) and (f) for a preset time, if the engine is not started, stopping the engine and checking the air-fuel ratio again to determine the decrease or increase of the fuel quantity factor.
Starting control method of the engine for power generation through continuous fuel amount control comprising a. The method of claim 1,
In step (e),
(e1) continuously reducing the fuel amount factor for the predetermined time when the oxygen concentration of the exhaust gas is rich through the sensing signal of the air-fuel ratio sensor; And
(e2) continuously increasing the fuel amount factor for the set time when the oxygen concentration of the exhaust gas is low through the sensing signal of the air-fuel ratio sensor;
Starting control method of the engine for power generation through continuous fuel amount control comprising a. The method of claim 2,
Determination of the rich or lean state of the exhaust gas, it is determined based on the oxygen concentration contained in the exhaust gas in the theoretical air-fuel ratio state, the start control method of the engine for power generation through continuous fuel amount control. The method of claim 2,
In the step (e1), the start-up control method of the power generation engine through the continuous fuel amount control, characterized in that for reducing the fuel amount factor in units of second intervals during the set time. The method of claim 2,
In the step (e2), the start-up control method of the engine for power generation through the continuous fuel amount control, characterized in that for increasing the fuel amount factor in units of second intervals during the set time. The method of claim 1,
The preset time is less than 10 seconds starting control method of the engine for power generation through continuous fuel amount control, characterized in that. The method of claim 2,
Starting control method of the engine for power generation through the continuous fuel amount control, characterized in that continuously reducing the fuel amount factor in the range of more than 0% and 50% or less in the step (e1). The method of claim 2,
Starting control method of the engine for power generation through the continuous fuel amount control, characterized in that continuously increasing the fuel amount factor in the range of more than 0% and less than 50% in the step (e2). The method of claim 1,
And the starting basic fuel amount is a fuel amount corresponding to a theoretical air-fuel ratio of the engine. The method of claim 1,
The activation of the air-fuel ratio sensor, the start control method of the engine for power generation through the continuous fuel amount control, characterized in that by activating by supplying power to the start key ON (ON) operation of the engine.

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