WO2016068638A1

WO2016068638A1 - Air-to-fuel ratio control system and method using composite sensor

Info

Publication number: WO2016068638A1
Application number: PCT/KR2015/011540
Authority: WO
Inventors: 김세원; 이창엽; 권민준
Original assignee: 한국생산기술연구원
Priority date: 2014-10-31
Filing date: 2015-10-30
Publication date: 2016-05-06
Also published as: CN107208890A; KR20160053211A; KR101759217B1

Abstract

The present invention relates to a system and method which compositely sense an exhaust gas and a flame state and perform an air-to-fuel ratio control using the same. An air-to-fuel ratio control system having a heater, according to the present invention, comprises: a burner, positioned at one side of the heater, for performing combustion by mixing a fuel and air being supplied; a stack, positioned at another side of the heater, for discharging an exhaust gas generated within the heater by the combustion; a flame sensor provided at one side of the heater; an exhaust gas sensor provided at one side of the stack; an input module to which information detected by the flame sensor and the exhaust gas sensor is inputted; a control module for computing a control value of the heater using the information inputted to the input module; and a drive module for controlling the fuel and air to be supplied to the heater according to the control value. As such, it is possible to control the air-to-fuel ratio more efficiently.

Description

Air-fuel ratio control system and control method using composite sensor

The present invention relates to an air-fuel ratio control system and a control method, and more particularly, to a system and method for detecting an exhaust gas and a flame state in combination and controlling the air-fuel ratio using the same.

Due to energy depletion and environmental issues, high efficiency and low pollution combustion systems are recently recognized as essential. In order to apply a high efficiency low pollution combustion system, a great deal of research and development has been conducted from a more fundamental point of view, such as a study on a burner capable of high efficiency low pollution operation and a study for efficient operation.

For example, Japanese Patent No. 2966862 measures a flame directly, and in the case of a fast reaction optical sensor, each radical of OH *, CH *, C2 * generated in a flame is measured by using an optical filter. The system for measuring the air-fuel ratio is disclosed. This system has the disadvantage that the price of the system is very high. In addition, the number of components such as optical filters, photomultipliers (PMT, photomultiplier), etc. are large and the size is relatively large, causing problems in miniaturization.

In addition, it is impossible to maintain the operating conditions (O2 condition of exhaust gas) suggested by the user like O2 measurement control, and it is impossible to operate more efficiently and is not sensitive to changes in the surrounding environment (temperature, humidity, etc.) There is a problem that there is a possibility of causing gas.

(Patent Document 1) JP 2966862 B2

Accordingly, the present invention has been made in order to solve the above-described problems, it is possible to cope with the above problems by applying a combination of O2 trimming control, CO trimming control, photometric control and active control depending on the performance of the burner It is possible to induce the optimum air-fuel ratio operation possible in the performance of the burner, thereby enabling high efficiency operation of the combustion system, and the optical measurement system using the optical fiber is applicable to various types of burners.

Therefore, the present invention is applicable to a variety of combustion systems, by enabling a high efficiency operation possible according to the performance of the applied combustion system, the control is possible in the existing limited conditions, the problem of not maximizing high efficiency operation with stable air-fuel ratio operation It is an object to provide an air-fuel ratio control system and a control method that can be overcome.

In order to achieve the above object, the air-fuel ratio control system using a composite sensor according to the present invention, in the air-fuel ratio control system having a boiler, located on one side of the boiler, the combustion by mixing the supplied fuel and air burner; Located on the other side of the boiler, the stack exhaust gas generated by the combustion inside the boiler; A flame sensor provided on one side of the burner; An exhaust gas sensor provided at one side of the stack; An input module to input information detected by the flame sensor and the exhaust gas sensor; A control module for calculating a control value of the burner by using the information input to the input module; And a driving module for controlling fuel and air supplied to the burner according to the control value.

The exhaust gas sensor preferably includes an O 2 sensor and a CO sensor.

The drive module preferably includes a plurality of dampers (Damper) for adjusting the amount of fuel and air supplied to the burner.

The plurality of dampers are preferably controlled by a proportional-integral-derivative (PID) method.

In addition, a control method of the air-fuel ratio control system having a boiler, comprising: (a) inputting initial information of the boiler to an input module; (b) the burner is ignited; (c) setting a heat input value of the boiler in the control module; (d) calculating, by the control module, an optimal control value using information of the O 2 concentration detected by the exhaust gas sensor and the optical sensor; (e) calculating, by the control module, an optimal control value using information of the CO concentration detected by the exhaust gas sensor; (f) a driving module controlling fuel and air supplied to the burner according to an optimum control value calculated from the information of the O 2 and CO concentrations, and setting an optical signal value at an input module; (g) determining whether the burner is extinguished from the light signal value of the burner detected by the flame sensor; (h) when the burner is extinguished, the input of the detected O 2 and CO concentrations and the setting of the heat input value and the light signal value are terminated, and when the burner is not extinguished, the optical signal sensed by the burner Determining whether a value coincides with the set optical signal value; And (i) performing the step (g) when the optical signal value detected by the burner and the set optical signal value coincide with each other. And controlling the driving module using the optimum control values calculated from the detected O 2 concentration, CO concentration, and optical signal value, and performing step (g). Provides a control method for the system.

The step (d) may include: (d10) inputting initial values of a fuel and a damper to an input module, and (d20) setting an O2 concentration to an input module; (d30) detecting the O2 concentration by using an O2 sensor installed in the stack 200 and an O2 measurement value using photometry; (d40) determining whether a difference between the sensed O2 concentration of the exhaust gas and the set O2 concentration exceeds a preset value; (d50) if the difference between the detected O2 concentration of the exhaust gas and the set O2 concentration exceeds a preset value, notifying the step, and ending step (d); (d60) when the difference between the detected O2 concentration and the set O2 concentration is less than a preset value, the difference between the detected O2 concentration and the set O2 concentration exceeds a preset value different from the preset value Determining whether or not; (d70) When the difference between the detected O2 concentration and the set O2 concentration exceeds the other preset value, it is determined whether the accumulated number of counters is equal to or greater than a preset number of counters, and When the difference between the O2 concentration and the set O2 concentration is less than the other predetermined value, the opening and closing amount of the damper is adjusted, the state of the damper is adjusted, the state of the damper is stored, and the step (d) Terminating; And (d80) if the accumulated number of counters is equal to or greater than a preset number of counters, adjust the amount of air supplied to the burner, increase the preset number of counters, perform step (d60), and accumulate the counters. If the number of less than the predetermined number of counters, adjusting the opening and closing amount of the damper, increasing the predetermined number of counters, and performing the step (d60); preferably comprises the step comprising a.

Step (e) may include: (e10) inputting initial values of a fuel and a damper to the input module; (e20) setting a limit concentration and an optimal concentration of CO in the input module; (e30) setting an adjustment amount of a damper on the input module; (e40) adjusting the supplied air by adjusting the adjustment amount of the set damper in the driving module; (e50) comparing, by the control module, the detected CO concentration with a limit concentration of the set CO; (e60) if the detected CO concentration exceeds the threshold concentration of the set CO, notifying it, adjusting the damper to the initial value, performing step (e30), and the detected CO concentration is set to the Determining whether the detected CO concentration is within a preset optimal concentration range when the CO concentration is less than or equal to the limit concentration; and (e70) when the sensed CO concentration is within a preset optimal concentration range, maintaining the adjusted amount of the set damper. And after storing it, the step (e) ends, and when the detected CO concentration is outside the preset range, the damper is adjusted according to the adjustment amount calculated by the detected CO concentration, and the (e40) It is preferable that the step comprising; performing a step).

In the step (i), the calculation of the optimal control value using the sensed optical signal value, (i10) calculating the variance from the set optical signal value and the sensed optical signal value, using a predetermined correlation equation ; (i20) determining whether the calculated variable exceeds 0; (i30) if the calculated variable exceeds 0, opening the damper to a preset adjustment amount; and if the calculated variable does not exceed 0, closing the damper to a preset adjustment amount; It is preferable.

As described above, according to the air-fuel ratio control system and control method using the composite sensor according to the present invention, by controlling the air-fuel ratio of the boiler using a complex sensor, in particular by adding a flame sensor for detecting a flame emission signal, The control reaction is rapid.

Under the boiler's main operating conditions, efficiency gains can be achieved over existing air-fuel ratio control systems.

In addition, it is possible to apply burner in a wide range of conditions, to enable the operation of the optimum efficiency condition of the burner, and to continuously monitor for disturbances, and to respond quickly to changes in flame speed and flame conditions, enabling stable operation. Do.

1 is a schematic diagram of an air-fuel ratio control system according to an embodiment of the present invention.

2 is a flowchart of an air-fuel ratio control method according to an embodiment of the present invention.

3 is a flowchart illustrating in detail a step of calculating an optimal control value by using information on sensed CO concentration, which is one step of the air-fuel ratio control method, according to an embodiment of the present invention.

4 is a flowchart illustrating in detail an operation of calculating an optimal control value using information on CO concentration detected by an exhaust gas sensor, which is one step of an air-fuel ratio control method, according to an embodiment of the present invention.

FIG. 5 is a flowchart illustrating in detail a step of calculating an optimal control value using an optical signal value which is one step of the air-fuel ratio control method according to an embodiment of the present invention.

6 is a view showing the response to the load variation during the control operation of the air-fuel ratio control system according to an embodiment of the present invention as O2 and CO concentration.

FIG. 7 is a diagram illustrating responsiveness to disturbance during ignition of a boiler, and compares an air-fuel ratio control system and an existing system according to an embodiment of the present invention.

8 is a view showing the responsiveness to disturbance during boiler fire, a view comparing the air-fuel ratio control system and the existing system according to an embodiment of the present invention.

9 is a view illustrating a flame emission signal and a photodiode spectral response detected in a flame of a burner during boiler operation.

Figure 10 shows the flame emission signal detected in the flame of the burner in the UV region according to the boiler operating conditions.

11 shows the efficiency according to the control operation of the air-fuel ratio control system and the control operation efficiency of the existing system according to an embodiment of the present invention.

12 illustrates changes in CO concentration and O 2 concentration of exhaust gas according to CO control in an air-fuel ratio control system according to an embodiment of the present invention.

FIG. 13 illustrates changes in CO concentration and O 2 concentration of exhaust gas according to O 2 and CO control in an air-fuel ratio control system according to an embodiment of the present invention.

The above objects, features and other advantages of the present invention will become more apparent by describing the preferred embodiments of the present invention in detail with reference to the accompanying drawings. In this process, the thickness of the lines or the size of the components shown in the drawings may be exaggerated for clarity and convenience of description. In addition, terms to be described below are terms defined in consideration of functions in the present invention, which may vary according to the intention or convention of a user or an operator. Therefore, definitions of these terms should be described based on the contents throughout the specification.

The described embodiments are provided by way of example for purposes of illustration, and do not limit the technical scope of the present invention.

Each component constituting the air-fuel ratio control system using the composite sensor of the present invention may be used integrally or separately separated as needed. In addition, some components may be omitted depending on the form of use.

First, with reference to the accompanying Figure 1 will be described an air-fuel ratio control system using a composite sensor according to an embodiment of the present invention.

Air-fuel ratio control system using a composite sensor according to an embodiment of the present invention as a control system for controlling the air-fuel ratio of the combustion made in the heat source, such as boiler 1000, the burner 100, the stack 200, flame sensor ( 110, an exhaust gas sensor 210, an input module 300, a control module 400, and a driving module 500 may be included.

Burner 100 is located on one side of the boiler 1000, and burns by mixing the fuel and air supplied to the burner (100). There are differences in the components included in the exhaust gas generated according to the air-fuel ratio, which is a mixture ratio of fuel and air supplied at the time of burning the burner 100, and the present invention effectively controls the air-fuel ratio.

The stack 200 is located at the other side of the boiler 1000 to discharge the exhaust gas generated in the boiler 1000 by the combustion of the burner 100.

Flame sensor 110 is to detect the flame burning in the burner 100, preferably an optical sensor for detecting the light generated from the flame for the measurement of the flame reaction area and the smooth measurement of the burner 100 of a complex structure Can be. Such an optical sensor may be made of an optical fiber, and preferably may be a lens-integrated fiber. The lens-integrated fiber has a larger NA (Numerical Aperture) than a general optical fiber. The NA of the optical fiber has a wide angle at which the light beam is combined with the optical fiber, which is a parameter required to predict the coupling with the light source.

In addition, the flame sensor 110, as shown in Figure 9, OH of the UV region is less affected by the other flame emission signal (CO2, soot) of the representative chemical emission signal (OH *, CH, C2 *) generated in the flame It may be a photodiode sensor for measuring a signal. Therefore, it may be desirable to measure around the OH * that represents the characteristics of the flame according to the air-fuel ratio of the flame.

Using this flame sensor 110, it is possible to observe the flame of a wider operating conditions range (see Fig. 10).

The exhaust gas sensor 210 is provided at one side of the stack 200 to sense the concentration of each component included in the exhaust gas discharged to the stack 200. Preferably, the exhaust gas sensor 210 may include an O 2 sensor and a CO sensor, thereby detecting the concentration of O 2 and CO contained in the exhaust gas.

The input module 300 is connected to the flame sensor 110 and the exhaust gas sensor 210, information of the flame and exhaust gas detected by the flame sensor 110 and the exhaust gas sensor 210, the exhaust gas set by the user The information and the fuel and air supplied to the burner 100, the amount of adjustment of the drive module 500 to be described later may be set.

The control module 400 calculates the operation control value of the appropriate burner 100 by using the respective information input to the input module 300, which will be described later.

The driving module 500 realizes an appropriate air-fuel ratio by adjusting the fuel and air supplied to the burner 100 according to the control value calculated by the control module 400. One or more dampers (Damper) for controlling the fuel and air supplied to the drive module 500, the damper is not limited to the control method, preferably by a PID (Proporation-Integral-Derivative) method It is desirable to regulate the fuel and air supplied.

In general, the exhaust gas measurement measured by the stack 200 includes a time delay due to the flow of the exhaust gas, and a time delay for stabilization of the exhaust gas sensor 210. Therefore, the exhaust gas sensor 210 installed in the stack 200 has a time delay according to the change in the flame conditions. This time delay increases the error of control and leads to an increase in stabilization time. Therefore, in the present invention, the measurement of the exhaust gas for control is performed by simultaneously applying not only the exhaust gas sensor 210 installed on the stack 200 but also the flame sensor 110 directly measuring the flame. This method measures the current exhaust gas concentration by applying the respective weights with the contents of the initial information of the boiler input by the user, and otherwise measures the O2 concentration using the flame sensor 110 for the control using the initial O2 concentration. In the latter part of the control, concentration measurement using the exhaust gas sensor 210 of the stack 200 is performed accurately.

Thus, there is an advantage that faster and more precise control is possible.

Hereinafter, an air-fuel ratio control method using a composite sensor according to an exemplary embodiment of the present invention will be described with reference to FIGS. 2 to 5.

First, the initial information of the boiler 1000 is input (S100).

Here, the initial information of the boiler 1000 is not limited, and means information required for operation of the boiler 1000 such as the size of the boiler 1000 and the capacity of the burner 100 to be installed.

Next, the burner 100 is ignited (S200).

Next, the heat input value of the boiler 1000 is set in the control module 400 (S300).

Next, the control module 400 calculates an optimal control value using information of the O 2 concentration detected by the flame sensor 110 and the exhaust gas sensor 210 (S400).

Using information of the O 2 concentration sensed by the exhaust gas sensor 210, as shown in FIG. 3, it may be desirable to calculate the optimum control value as the following steps.

First, initial values of the fuel and the damper are input to the input module 300 (S410).

Next, the O2 concentration is set in the input module 300 (S420).

The O 2 concentration here is calculated using the O 2 measurement value using the exhaust gas sensor 210 and the flame sensor 110 installed in the stack 200. This calculation is preferably calculated using the weight of the exhaust gas sensor 210 and the flame sensor 110 installed in the stack 200 of the initial information of the boiler. This is because the O2 using the flame sensor 110 is faster than the O2 sensor installed in the stack 200 it is possible to control faster.

Next, it is determined whether the difference between the detected O2 concentration of the exhaust gas and the set O2 concentration exceeds a preset value (S430).

The preset value here is to prevent the error of the damper set value and the failure of the drive module 500 when exceeded, and is preferably set higher than the optimum value to be controlled. For example, 3 It may be set to a value of ˜5%, but is not limited thereto.

Next, when the difference between the sensed O2 concentration of the exhaust gas and the set O2 concentration exceeds a preset value, the controller is notified of this, and calculating the optimum control value using the information of the O2 concentration (S400) ends (S431). ).

On the other hand, when the difference between the detected O2 concentration of the exhaust gas and the set O2 concentration is less than a predetermined value, it is determined whether the difference between the detected O2 concentration and the set O2 concentration exceeds a predetermined value different from the predetermined value. It is determined (S440).

Herein, another preset value is a setting value for actually adjusting the damper. For example, a value around 0.2% may be set, but the present invention is not limited thereto, and the error of the damper setting value and the failure of the driving module 500 are not limited thereto. It is sufficient if it is set lower than the set value to prevent.

Next, when the difference between the detected O2 concentration of the exhaust gas and the set O2 concentration exceeds another predetermined value, it is determined whether the accumulated number of counters is equal to or greater than the preset number of counters (S450).

In the present air-fuel ratio control method, since part of the feedback control (feedback) according to the condition (condition), the control system may fall into an infinite loop. It is not a problem if the control method inherently in mind, but this air-fuel ratio control method may be a problem in such a case, it is terminated when the number of repetitions according to the condition by setting a constant counter. The number of counters is not limited and can be set arbitrarily by a user.

Next, when the difference between the detected O 2 concentration and the set O 2 concentration is less than another predetermined value, the opening and closing amount of the damper is adjusted (S441), the state of the damper is adjusted, and the state of the damper is stored. In operation S442, the calculation of the optimum control value using the information of the O 2 concentration is terminated.

On the other hand, if the accumulated number of counters is greater than or equal to the preset number of counters, the amount of air supplied to the burner 100 is adjusted (S460), the preset number of counters is increased, and the detected O2 concentration and the set O2 Determining whether or not the difference in concentration exceeds a predetermined value different from the predetermined value (S450) (S470),

If the accumulated number of counters is less than the preset number of counters, the opening and closing amount of the damper is adjusted (S451), the preset number of counters is increased, and the difference between the detected O2 concentration of the exhaust gas and the set O2 concentration is a preset value. In operation S450, it is determined whether or not a predetermined value different from the predetermined value is exceeded (S452).

Next, in the control module 400, an optimal control value is calculated using the sensed CO concentration information (S500). Using information of the CO concentration sensed by the exhaust gas sensor 210, as shown in FIG. 4, it may be desirable to calculate an optimal control value as the following steps.

First, initial values of the fuel and the damper are input to the input module 300 (S510).

Next, the limit concentration and the optimal concentration of CO are set in the input module 300 (S520).

That is, the limit concentration and the optimum concentration of CO which should not be included in excess of the exhaust gas discharged to the stack 200 are set.

Next, the adjustment amount of the damper is set in the input module 300 (S530).

The user sets the damper adjustment amount in advance.

The air supplied is adjusted by adjusting the adjustment amount of the damper set by the driving module 500 (S540).

The control module 400 compares the detected CO concentration with the limit concentration of the set CO (S550).

If the sensed CO concentration exceeds the limit of the set CO, it is notified (S551), the damper is adjusted to the initial value, and the adjustment amount of the damper is performed (S530).

On the other hand, if the detected CO concentration is less than the threshold concentration of the set CO, it is determined whether the detected CO concentration is within the predetermined optimal concentration range (S560).

When the detected CO concentration is within a preset optimal concentration range, the control amount of the set damper is maintained and stored (S570), and the optimal control value is calculated using the information of the CO concentration (S500). and,

On the other hand, if the detected CO concentration is outside the preset range, adjusting the damper according to the adjustment amount calculated by the detected CO concentration (S561), and adjusting the supplied air by adjusting the adjustment amount of the set damper S540 is performed again.

At this time, in the step of adjusting the damper according to the adjustment amount calculated by the detected concentration of CO, the adjustment amount of the damper may be calculated step by step, in this case, it can be calculated by the following equation.

Next, the driving module 500 controls the fuel and air supplied to the burner 100 according to the optimum control value calculated from the information of the O 2 and CO concentration, and the optical signal value is set in the input module 300. (S600).

The user can preset the optical signal value.

Next, it is determined whether the burner 100 is extinguished from the optical signal value of the burner 100 sensed by the flame sensor 110 (S700).

When the burner 100 is extinguished, the input of the detected O 2 and CO concentration and the setting of the heat input value and the optical signal value are terminated (S800),

If the burner 100 is not extinguished, it is determined whether the optical signal value detected by the burner 100 and the set optical signal value match (S900).

Next, when the optical signal value detected by the burner 100 and the set optical signal value match, performing the step (S900) of determining whether the optical signal value detected by the burner 100 and the set optical signal value match. ,

On the other hand, if there is a mismatch, the optimum control value is calculated using the detected optical signal value, and the driving module 500 is controlled by using the optimum control value calculated from the detected O 2 concentration, CO concentration, and optical signal value. In operation S1000, it is determined whether the optical signal value detected by the burner 100 matches the set optical signal value (S900).

In this case, the calculation of the optimal control value using the sensed optical signal value, as shown in Figure 5, it may be preferably performed through the following steps.

First, the variance is calculated by using a predetermined association equation between the set optical signal value and the sensed optical signal value (S1100).

Preferably, the variable can be calculated by the following equation.

In the above equation, the variable> 0 indicates that the air-fuel ratio increases, and the variable <0 indicates that the air-fuel ratio decreases. In addition, the value of 5% is an arbitrary value, of course, the user can be used arbitrarily set.

Next, it is determined whether the calculated variable exceeds 0 (S1200).

As described above, since the air-fuel ratio decreases or increases based on the variable 0, it is determined whether the variable exceeds O.

Next, when the calculated variable exceeds 0, the damper is opened with a preset adjustment amount (S1300),

On the other hand, if the calculated variable does not exceed 0, the damper is closed with a preset adjustment amount (S1300).

In this way, by controlling the air-fuel ratio of the boiler 1000 by using a complex sensor, and in particular by adding a flame sensor 110 for detecting a flame emission signal, the control reaction according to the situation is quick, Figure 6, the boiler ( 1000) shows the response to the load variation during the control operation by measuring the O2 and CO concentration, Figure 7 and Figure 8 shows the response of the photo-measurement signal to the disturbance that occurs and the ignition in the existing system (Fig. 7) And digestion (FIG. 8), as shown, the responsiveness of the photometric signal is about 50 seconds faster on average than conventional systems.

In addition, by using the air-fuel ratio control system and method using the composite sensor as described above, as shown in Figure 11, under the load conditions of 30 ~ 70%, which is the main operating condition of the

boiler

1000, 2 than the existing air-fuel ratio control system Efficiency improvement of more than% was confirmed.

And, Figure 12 shows a change in the CO concentration and O2 concentration of the exhaust gas according to the CO control in the air-fuel ratio control system according to an embodiment of the present invention, Figure 13 is an air-fuel ratio control system according to an embodiment of the present invention The change of CO concentration and O2 concentration of exhaust gas by O2 and CO control of is shown. Here, it can be seen that the control is quickly made in response to the change in the CO or O2 concentration of the exhaust gas.

As described above, according to the air-fuel ratio control system and method according to the present invention, it is possible to apply a burner of a wide range of conditions, to enable the operation of the optimum efficiency conditions that the burner has, and to continuously monitor for disturbance, fast response speed Stable operation is possible because of immediate reaction in case of fire condition change.

Although described above with reference to a preferred embodiment of the present invention, those of ordinary skill in the art various modifications and variations of the present invention within the scope and spirit of the present invention described in the claims below It will be appreciated that it can be changed.

1000: boiler

100: burner

110: flame sensor

200: stack

210: exhaust gas sensor

300: input module

400: control module

500: drive module

Claims

In the air-fuel ratio control system provided with the boiler 1000,

A burner (100) positioned on one side of the boiler (1000) to perform combustion by mixing supplied fuel and air;

Located on the other side of the boiler 1000, the stack 200, the exhaust gas generated by the combustion in the boiler 1000 is discharged;

A flame sensor 110 provided on one side of the burner 100;

An exhaust gas sensor 210 provided on one side of the stack 200;

An input module 300 to which information detected by the flame sensor 110 and the exhaust gas sensor 210 is input;

A control module 400 for calculating a control value of the burner 100 by using the information input to the input module 300; And

Characterized in that it comprises a; drive module 500 for controlling the fuel and air supplied to the burner 100 in accordance with the control value

Air-fuel ratio control system using composite sensor.
The method of claim 1,

The exhaust gas sensor 210 includes an O 2 sensor and a CO sensor,

Air-fuel ratio control system using composite sensor.
The method of claim 1,

The drive module 500 includes a plurality of dampers (Damper) for adjusting the amount of fuel and air supplied to the burner 100,

Air-fuel ratio control system using composite sensor.
The method of claim 3, wherein

The plurality of dampers are adjusted by the Proportional-Integral-Derivative (PID) method.

Air-fuel ratio control system using composite sensor.
As a control method of the air-fuel ratio control system provided with the boiler 1000,

(a) inputting initial information of the boiler 1000 into an input module 300;

(b) the burner 100 is ignited;

(c) setting the heat input value of the boiler 1000 in the control module 400;

(d) calculating, by the control module 400, an optimal control value using information of the O 2 concentration detected by the photometric sensor 110 and the exhaust gas sensor 210;

(e) calculating, by the control module 400, an optimal control value using information of the CO concentration detected by the exhaust gas sensor 210;

(f) the driving module 500 controls the fuel and air supplied to the burner 100 according to the optimum control value calculated from the information of the O2 and CO concentrations, and the optical signal value is set in the input module 300. Becoming;

(g) determining whether the burner 100 is extinguished from the optical signal value of the burner 100 sensed by the flame sensor 110;

(h) when the burner 100 is extinguished, the input of the detected O 2 and CO concentration and the setting of the heat input value and the optical signal value are terminated,

Determining whether the burner 100 matches the light signal value detected by the burner 100 and the set light signal value if the burner 100 is not extinguished; And

(i) if the optical signal value detected by the burner 100 and the set optical signal value match, perform step (g),

If it does not match, the optimum control value is calculated using the detected optical signal value, and the driving module 500 is controlled by using the optimum control value calculated from the detected O 2 concentration, CO concentration, and optical signal value. And, performing the step (g).

Control method of air-fuel ratio control system using compound sensor.
The method of claim 5, wherein

In step (d),

(d10) inputting initial values of a fuel and a damper to the input module 300,

(d20) setting the O2 concentration in the input module 300 by using a photometer sensor and an exhaust gas O2 meter;

(d30) determining whether a difference between the detected O 2 concentration of the exhaust gas and the set O 2 concentration exceeds a preset value;

(d40) if the difference between the detected O2 concentration of the exhaust gas and the set O2 concentration exceeds a preset value, notifying the step, and ending step (d);

(d50) when the difference between the detected O2 concentration and the set O2 concentration is less than a predetermined value, the difference between the detected O2 concentration and the set O2 concentration exceeds a preset value different from the preset value. Determining whether or not;

(d50) if the difference between the detected O2 concentration of the exhaust gas and the set O2 concentration exceeds the other preset value, it is determined whether the number of accumulated counters is greater than or equal to the preset number of counters,

When the difference between the sensed O2 concentration of the exhaust gas and the set O2 concentration is less than the other predetermined value, the opening and closing amount of the damper is adjusted, the state of the damper is adjusted, and the state of the damper is stored, Terminating the step (d); And

(d60) If the accumulated number of counters is equal to or greater than a preset number of counters, the amount of air supplied to the burner 100 is adjusted, the preset number of counters is increased, and the step (d50) is performed.

If the accumulated number of counters is less than a predetermined number of counters, adjusting the amount of opening and closing of the damper, increasing the number of preset counters, and performing step (d50).

Control method of air-fuel ratio control system using compound sensor.
The method of claim 5, wherein

In step (e),

(e10) inputting initial values of a fuel and a damper to the input module 300;

(e20) setting a limit concentration and an optimal concentration of CO in the input module 300;

(e30) setting an adjustment amount of a damper on the input module 300;

(e40) adjusting the supplied air by adjusting the adjustment amount of the set damper in the driving module 500;

(e50) comparing the detected CO concentration with a limit concentration of the set CO in the control module 400;

(e60) if the detected CO concentration exceeds the threshold concentration of the set CO, notifying it, adjusting the damper to the initial value, and performing the step (e30),

Determining whether the detected CO concentration is within a preset optimal concentration range when the sensed CO concentration is less than or equal to the threshold concentration of the set CO: And

(e70) If the detected CO concentration is within a preset optimal concentration range, the control amount of the set damper is maintained, stored, and then the step (e) is terminated.

If the detected CO concentration is outside the preset range, adjusting the damper according to the adjustment amount calculated by the detected CO concentration, and performing the step (e40);

Control method of air-fuel ratio control system using compound sensor.
The method of claim 5, wherein

In the step (i), the calculation of the optimum control value using the detected optical signal value,

(i10) calculating a variance of the set optical signal value and the sensed optical signal value using a predetermined correlation equation;

(i20) determining whether the calculated variable exceeds 0;

(i30) If the calculated variable exceeds 0, the damper is opened with a preset adjustment amount,

If the calculated variable does not exceed 0, closing the damper to a predetermined adjustment amount; comprising;

Control method of air-fuel ratio control system using compound sensor.