JP2001141234A - Method of adjusting characteristic curve of burner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To quickly and inexpensively optimize the characteristic curves of a burner. SOLUTION: In a method for adjusting characteristic curves of burner, the air characteristic curve, fuel characteristic curve, and auxiliary characteristic curve of a burner are adjusted. At the time of adjusting the curves, the output value of the burner is changed starting from the output values P1 of the air value A1 and fuel value F1, and the flow rates of air and fuel are changed in a first direction R1 until the exhaust gas value changes. Continuously, the next air value A2 and fuel value F2 are set at the next output value P2 so that a prescribed exhaust gas value may be obtained. Also continuously, the flow rates of air and fuel are changed in the direction which is decided by the results of the exhaust gas measurement and the preceding exhaust gas measurement. In such a constitution, the characteristic curves of the burner can be adjusted so that a prescribed exhaust gas value may be obtained at all output values.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for adjusting a characteristic curve of a burner, and more particularly to a method for obtaining a predetermined exhaust gas value by using an air value and a fuel value as values representing the air flow rate and the fuel flow rate of the burner. Thus, the invention relates to a method for adjusting a characteristic curve of a burner or a combustion device in which the air value, the fuel value and the auxiliary value, if provided, are changed based on the output value of the burner.

[0002]

2. Description of the Related Art Various methods for adjusting the characteristic curve of a burner are known. In that case, different air values, fuel values or other regulating parameters for each burner output value and / or auxiliary values for the auxiliary drive of the combustion device are stored in the computer, thereby determining the required output, A computer regulates components such as the pump, regulating unit and ventilator so that the burner reaches a corresponding output value. In that case, care is taken, in particular in modern combustion systems, to obtain a predetermined exhaust gas value which is as optimal as possible for each output value.

Since at least one air value and fuel value must be determined for each burner output value and a predetermined exhaust gas value must be maintained, a method for adjusting the burner characteristic curve, that is to say the individual burner characteristics, is used. It is known to determine a corresponding air or fuel value for an output value. In such a method, the air supply amount or the fuel supply amount is changed successively or repeatedly until an optimum exhaust gas value is obtained for the corresponding output value. In that case,
Output "adjusted" according to air supply or fuel supply
Is done. For example, DE 3039994 C2 or E
From P0209771 A1, at the start of operation of the burner for the first time, the optimum air supply is determined individually by individually selecting the fuel value in the load area of interest and measuring the corresponding exhaust gas value and storing it in the computer. It is known to

[0004] Furthermore, from DE 197 49 506 C1, from the point of time when the fuel flow rate becomes constant during the operation of the combustion device, the characteristic curve of the burner is optimized by changing the amount of air supply, for example, smoke gas in the exhaust gas. It is known to determine the minimum required air supply depending on whether it occurs.

[0005]

However, in these known methods, the characteristic curve of the burner can be determined only when the fuel flow rate is determined. This is because the optimal combustion air supply is non-linear with respect to the corresponding fuel flow. Depending on the burner structure, the type of fuel, and the structure of the heating device or the combustion device, the optimum air-fuel ratio at each output value of the burner will be different.

In the known method of adjusting the corresponding characteristic curve, the adjustment of such a characteristic curve is very time-consuming and expensive, since the individual points are determined sequentially, and the actual use of the combustion device takes place. At the same time, there is the disadvantage that the combustion or exhaust gas values are not optimized simply by preliminarily adjusting such a characteristic curve on the factory side. In such a case as well, the operator or installer of the heating installation must successively optimize the characteristic curves of the burners individually, ie, point by point.

It is an object of the present invention to improve the known method of adjusting the characteristic curve of a burner so that the corresponding characteristic curve can be determined quickly and inexpensively.

[0008]

In order to solve the above-mentioned problems, according to the present invention, a predetermined exhaust gas value is obtained by using an air value and a fuel value as values representing an air flow rate and a fuel flow rate of a burner (1). The characteristic curve of the burner in which the air value (A _i ), the fuel value (F _i ) and possibly the auxiliary value (H _i ) are changed on the basis of the output value (P _{1... N} ) of the burner is adjusted. And the output (P) of the burner (1) is:
Changing the output (P), starting from a _first output value (P ₁ ) having an air value (A ₁ ), a fuel value (F ₁ ) and possibly an auxiliary value (H ₁ ) Until the exhaust gas value changes at the next output value (P _{i + 1} )
The next output value (P _{i + 1} ) is changed such that the air flow rate and / or the fuel flow rate and / or the auxiliary drive is respectively changed in the first direction (R _i ) and the predetermined exhaust gas value is obtained again. At least one next air value (A _{i + 1} ) and / or at least one next fuel value (F _i )
_{i + 1} ) is determined and the output (P) is varied starting from the next output value (P _{i + 1} ), the air flow and / or the fuel flow and / or the auxiliary drive are at least A configuration is adopted in which each is changed in the next direction (R _{i + 1} ) determined by the result of another one of the exhaust gas measurements.

[0009] Preferred embodiments are also described and claimed in the dependent claims.

The method according to the invention for adjusting the characteristic curve of the burner air and fuel or of the auxiliary drive comprises the following steps.

First, the output of the burner is the first air value,
The first output value with the first fuel value and possibly the first auxiliary value is varied as a starting point. In that case, by changing the output, the air flow rate and / or the fuel flow rate and / or the auxiliary drive are respectively changed in the first direction. The respective first direction is the direction in which the entire complex (all the adjusting elements or drives) is displaced along a substantially defined characteristic curve (characteristic point), such a displacement resulting in a change in the exhaust gas value. And the output value at which the exhaust gas value changes is set as the next output value. Therefore, the exhaust gas value changes at the next output value and does not fall within the predetermined allowable range. During such an adjustment, the only parameter is an adjustment of the power, and the individual air values and the fuel values and / or auxiliary values are automatically changed along the first direction. Thus, the installer does not repeatedly change the individual values one after the other, but only changes the corresponding output of the burner.

Subsequently, at the next output value, the corresponding air flow rate or the corresponding fuel flow rate or the auxiliary value of the auxiliary drive is changed so that a predetermined exhaust gas value is again obtained. That is, the corresponding air value or fuel value is changed at this output value to determine the next air value and the next fuel value, and the predetermined exhaust gas value can be obtained again there.

If the output of the burner is subsequently changed again, the air flow and the fuel flow and possibly also the auxiliary values of the auxiliary drive are no longer (automatically) changed in the first direction, but (automatically). It is changed in another direction, ie this time and at least one other time, for example the next direction determined from the previous exhaust gas measurement result. Thereafter, these three steps are repeated successively until the terminal value or the maximum output value of the output, that is, the rated output of the burner is reached.

If the output value for a small load (low load) is not known, the ignition point of the burner, for example, is used as a first starting point. As the output value, a fuel value determined by the ignition position is temporarily used. This ignition position can be used as an output value at low load for the time being. However, if the minimum load (small load) of the burner is known as the first output value, that is, the first output value, It is preferable to use In that case, at the beginning of the regulation, the air flow and the fuel flow and possibly also the auxiliary drive, when the power is correspondingly increased, the maximum value at which the burner output is at a maximum (maximum air flow or fuel flow). Flow rate). Thus, when the power is increased, the air flow or fuel flow is calculated starting from the first, e.g. minimum, air or fuel value in the power-air-fuel diagram, or starting from the value of the ignition position. It is increased linearly along a straight line passing through the maximum air or fuel value (adjustment member opening 90 °; output 100%). Starting from this first value, the output value is then increased (increased air flow or fuel flow) until the exhaust gas value changes. At the point where the exhaust gas value changes (intermediate point), a new value for the fuel value, air value or auxiliary value is determined and stored.

After determining the next air or fuel value,
When changing the output, the air flow or fuel flow
For example, they are varied along other directions obtained by extrapolating a straight line through the current air or fuel value, respectively. This straight line does not pass through the previously used end point, the intersection of the maximum power at the maximum fuel flow as well as the maximum air flow, and extends along another straight line.

After obtaining the next air value and / or the next fuel value or the next auxiliary value, the air flow rate and / or the fuel flow rate or the auxiliary driving device are controlled by the output adjusting direction,
That is, according to whether the output change direction is performed in the direction of a larger output value or in the direction of a smaller output value, the maximum value of the air flow rate and the fuel flow rate when the burner output becomes maximum or minimum, respectively, or It is also possible to vary along the direction of the minimum value or the maximum or minimum value of the displacement of the auxiliary drive. In that case,
Using the obtained latest value, a characteristic curve between that value and the previously obtained value is determined.

In the method of adjusting the air characteristic curve or the fuel characteristic curve of the burner, other characteristic curves can likewise be determined. This is, for example, the characteristic curve of an auxiliary drive (for example a motor) for driving an auxiliary pump, an auxiliary fan or other device or for driving another adjusting member for adjusting the burner. The overall parameters, i.e. all the parameters that can be adjusted, can be determined at the same time as moving to the respective (i.e. new) output values. The following criteria can be used when setting the output value and then re-adjusting the air value, the fuel value or other values, and thereby determining the new direction of the characteristic curve extending therefrom.

Since various combustion values having a predetermined allowable range can be used as the predetermined exhaust gas value, one of the combustion values can be used.
The next fuel value, the next air value, or another value is determined when the upper or lower limit of one or more tolerance ranges is exceeded or falls below.

The air or fuel characteristic curve or other characteristic curve is obtained by successively joining the individual sections between the previously determined air or fuel values. Adjustment of such a characteristic curve is performed before starting the burner or during maintenance work in order to optimize the burner. If the part of the burner or the burner device itself is replaced, the corresponding characteristic curve can be quickly and simply reset by the method according to the invention. In that case, there is no need to adjust the corresponding open-loop or closed-loop control at the factory.

After the burner characteristic curve or the individual fuel characteristic curve or the air characteristic curve has been adjusted for the first time, the tolerances of the various combustion values are reduced or reduced, thereby setting stringent conditions on the shape of the characteristic curve. be able to.
By newly "optimizing" the characteristic curve, i.e. by passing again through the individual output areas of the burner, a new "optimization point" or output value of the burner when above or below a smaller tolerance band At the output value, the individual air value, fuel value or other value can be optimized, i.e. readjusted, so that the exhaust gas value again falls within the reduced tolerance range.

Thus, the burner can be optimized with arbitrary precision by successively joining the individual straight sections.

For this purpose, according to another preferred embodiment of the invention, the output value is moved along the adjusted characteristic curve to a new output value so that a predetermined exhaust gas value is obtained again. It is also possible to determine a fuel value and / or an auxiliary value. In that case, the characteristic curve is adjusted or reset with the new air value and / or fuel value and / or auxiliary value.

According to another preferred embodiment of the present invention,
Similarly, along the characteristic curve that has been adjusted, it is moved to a predetermined output value, and at this predetermined output value the air value and / or
Or if a new output value is determined based on the fuel value and / or the auxiliary value or by power measurement, and it is found that the new output value does not match the original output value, the characteristic curve is formed using the new output value. Adjustment or resetting is also possible.

It is also possible to combine the two methods described above, and to move to a predetermined output value along the adjusted characteristic curve and to obtain a new exhaust gas value again so as to obtain a predetermined exhaust gas value. Values and / or fuel values and / or auxiliary values are determined, in which case new output values are determined based on new air values and / or fuel values or auxiliary values at the output values or by power measurement, and new air values and / or It is also possible to adjust or reset the characteristic curve using the fuel value and / or the auxiliary value and the new output value.

The air adjusting member for adjusting the air flow rate, the fuel adjusting member for adjusting the fuel flow rate, or the auxiliary driving device is changed at a predetermined ramp speed. In that case, the ramp speed is the displacement speed which changes the adjusting member or its driving device, preferably 3 ° to make a 90 ° displacement.
It takes 0 to 120 seconds. According to the respective characteristic curve, i.e. the "slope" of the characteristic curve section connecting the two values of the air-conditioning element, the fuel-conditioning element or the auxiliary drive, each regulating element or drive has a flow rate characteristic curve,
That is, it is changed at an individual ramp speed so as to follow the slope of the characteristic curve. The output change is, for example, 5%, the air characteristic curve section is between 30 ° and 40 °, and the fuel characteristic curve section is 2%.
Between 5 ° and 30 °, set ramp speed is 30s / 9
At 0 °, the air conditioner is adjusted at full ramp speed and the fuel conditioner is adjusted at half ramp speed. In that case, the time required for it is 3.33 s. As a result, the entire complex (adjusting element or drive) is moved along the characteristic curve during a power change, in which case it is temporarily displaced from the characteristic curve, combustion deteriorates, and pollutant emissions increase. There is no such thing.

In addition, by using three, four or more points of each characteristic curve to determine an appropriate function, the corresponding "sampling value" of each determined, ie, corresponding, output value is obtained. The air or fuel values can also be combined by a second, third or higher order function. In that case, the requirements for the accuracy of the individual characteristic curves can be met in accordance with the respective interpolation (interpolation) algorithms.

[0027]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail based on embodiments shown in the drawings.

FIG. 1 schematically shows a burner 1 to which fuel 3 and air 2 are supplied. A burner controller (controller) 7 is provided for controlling the air supply amount (air flow amount) or the fuel supply amount (fuel flow amount), and the burner controller includes a fuel adjusting member 4 for adjusting the fuel flow amount, and The air adjusting member 5 for adjusting the air flow rate is controlled. To control the air supply or the fuel supply, the burner controller 7 receives the signal of an exhaust gas sensor 6, by means of which a number of exhaust gas values or combustion values of the exhaust gas 8 are supplied to the burner controller 7. For each output value P _{1... N of the} burner 1, an optimum air value A _i or fuel value F _i is determined and, using this, the burner controller 7 optimally regulates the combustion process by means of a characteristic curve. The method of the present invention for adjusting

A preferred process for carrying out the method of the present invention will be described with reference to FIGS.

Adjusting members 4 to 5 of characteristic curves 2, 3, H
Alternatively, after setting the other auxiliary drive device at a predetermined position, first, the ignition position Z of each characteristic curve is obtained. If fuel, air and auxiliary drives are provided, as shown in FIG. 2, three different positions are obtained for the auxiliary drives.

After setting the ignition position Z, the burner 1 is moved after the start of operation, for example, if the first output value P ₁ representing the low load (small load) position is known. Otherwise, the ignition position is used, in which case the fuel value at the ignition position is used as the output value. In this way, the air value A ₁ , the fuel value F ₁ and the value of the displacement of the auxiliary drive or the value of the drive amount (hereinafter referred to as the auxiliary value H ₁ ) are obtained. The first output value as a low load position, if not previously entered, the control device, i.e. a burner controller 7 now, the first output position, i.e. ignition position for the first output value P ₁ Z Is used.

The actual adjustment of the burner characteristic curve then takes place. What is adjusted is the characteristic curve of fuel 3, air 2
And the characteristic curve H of the auxiliary drive device. In a preferred embodiment of the invention, the operator changes the output value by increments in order to adjust the characteristic curve of the burner. The starting point in that case is the above-mentioned first output value P ₁ , for example, a low load point. From there, the burner 1 is operated by manual operation or automatic operation in a direction to increase the output. In this first direction, the values of fuel or air, etc., are respectively the first point and the maximum point at which the displacement of the adjusting member 4 or 5 at the maximum power is maximum (shown as 90 ° in FIG. 2). ) Is varied along a straight line. Accordingly, the fuel value, air value or auxiliary value is varied along an interpolated (interpolated) and / or extrapolated (extrapolated) straight line. This maximum point X is therefore used as an auxiliary point for determining the direction of the individual characteristic curves starting from the first air value A ₁ , the fuel value F ₁ and the auxiliary value H ₁ . This first direction is indicated in FIG. 2 by R ₁ with respect to the characteristic curve H of the auxiliary drive.

FIG. 3 shows a second output value P ₂ , at which the combustion value, ie the predetermined exhaust gas value (optimal exhaust gas value), is no longer obtained. Or the exhaust gas value changes so that it does not fall within the predetermined allowable range. In this output value P _2, again given the new air value such that the exhaust gas value, fuel value and the auxiliary value is determined. After a new adjustment to the corresponding air value A ₂ , fuel value F ₂ and auxiliary value H ₂ , a new direction R ₂ is determined for the air 2, fuel 3 and auxiliary characteristic curves H, respectively. . These new direction R ₂ is a straight line respectively through to the last two points A _1, A ₂ no F _1, F ₂ or alternatively H _1, H ₂ obtained by extrapolating.

In this way, the installer of the heating apparatus, the operator of the burner or the one who performs maintenance service is
The output value can be varied up to the point where the burner reaches its maximum output, that is, its rated output _Pmax .

Accordingly, as shown in FIG. 4, a characteristic curve obtained by sequentially connecting the individual linear portions to each other is obtained. In that case, the various directions are illustrated as R ₁ , R ₂ or R ₄ .

[0036] After determining the individual characteristic curve of the burner using the method according to the invention, in the present invention, as shown in FIG. 4, for example, as a starting point the air value A _5, along a predetermined characteristic curve The burner can be further fine-tuned by changing it backwards. This “downward” movement allows finer adjustment by making the allowable range of the combustion value smaller. However, in that case it is also possible to move to the individual output values within a predetermined value (for example in the central region) and to further optimize the characteristic curve.

In order to determine the individual sampling points of each characteristic curve, the output data, ie the output values, and the position data of the used adjusting member, for example, the fuel adjusting member 4 or the air adjusting member 5 or its drive, are determined. Are suitable.

FIG. 5 shows another method of adjusting the characteristic curve. In that case, after determining the next air value A _{i + 1} and / or the next fuel value F _{i + 1} and / or the next auxiliary value H _{i + 1} , the air flow rate and / or the fuel flow rate and / or the auxiliary drive The device has a maximum or minimum air flow and fuel flow or a maximum or minimum displacement of the auxiliary drive or a value of the drive amount R _x , R _{0 at} which the burner output reaches the maximum or minimum P _max , P ₀ , respectively. Is varied along. In that case, for example, defines the air characteristic curve between second air value A ₂ and the third air value A ₃ using the third air value A _3, whereas the air flow in the direction in which the output becomes large, 3 It is changed along a straight line defined by the _third air value A ₃ and the auxiliary value X.

The air characteristic curves described in connection with the above figures,
In the fuel characteristic curve and the auxiliary characteristic curve, at least one characteristic curve is adjusted, and each one characteristic curve, or two characteristic curves thereof, or all characteristic curves can be adjusted, and the air value, the fuel value, The auxiliary value is adjusted accordingly.

[0040]

As described above, according to the present invention, the characteristic curve of the burner can be adjusted quickly and inexpensively.
By optimizing the characteristic curve of the burner, it becomes possible to operate the burner optimally with a low exhaust gas value.

[Brief description of the drawings]

FIG. 1 is a configuration diagram schematically showing a configuration of a burner according to the present invention.

FIG. 2 is a diagram showing an initial process for adjusting three characteristic curves of a burner.

FIG. 3 is a diagram showing a next process for adjusting three characteristic curves of a burner.

FIG. 4 is a diagram showing a final process for adjusting three characteristic curves of a burner.

FIG. 5 is a diagram showing another embodiment for adjusting a characteristic curve of a burner.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Burner 2 Air 3 Fuel 4 and 5 Adjusting member 6 Exhaust gas sensor 7 Burner controller 8 Exhaust gas

Claims (11)

[Claims] An air value and a fuel value are defined as values representing an air flow rate and a fuel flow rate of a burner (1), and are based on output values (P _{1... N} ) of the burner so as to obtain a predetermined exhaust gas value. A method for adjusting a characteristic curve of a burner in which the air value (A _i ), the fuel value (F _i ) and possibly the auxiliary value (H _i ) are varied, wherein the output (P) of the burner (1) is , The first output value (P ₁ ) having the air value (A ₁ ), the fuel value (F ₁ ) and possibly the auxiliary value (H ₁ ), to change the output (P) Thereby, the air flow rate and / or the fuel flow rate and / or the auxiliary drive are respectively changed in the first direction (R _i ) until the exhaust gas value changes at the next output value (P _{i + 1} ), and again as the predetermined exhaust gas value is obtained, low in the next output value (P i _{+ 1)} With the next one air values (A i _{+ 1)} and / or at least the next one of the fuel value (F
_{i + 1} ) is determined, and if the output (P) is changed starting from the next output value (P _{i + 1} ), the air flow and / or the fuel flow and / or the auxiliary drive will A method for adjusting the characteristic curve of a burner, characterized in that it is changed in each of the following directions (R _{i + 1} ) determined by the results of another exhaust gas measurement. 2. The ignition position of the burner (1) or the minimum load value (P _min ) is used as the first output value (P ₁ ). When the output (P) is increased, the air flow rate and the fuel flow rate are increased. In some cases, the auxiliary drive may include a first airflow and a fuel flow at the maximum burner output ( _Pmax ) or a maximum displacement of the auxiliary drive.
2. The method according to claim 1, characterized in that it is changed linearly in the direction (R ₁ ). 3. The output (P) is changed after a next air value (A _{i + 1} ) and / or a next fuel value (F _{i + 1} ) or a next auxiliary value (H _{i + 1} ) are obtained. In this case, the air flow and / or the fuel flow or the auxiliary drive are, respectively, the last two air values (A _i ; A _{i -1} ) or the fuel values (F _i ; F _i-1 ) or the auxiliary values (H _i). Method according to claim 1 or 2, characterized in that it is varied along a _second direction (R2) obtained by extrapolation or interpolation of a straight line passing through Hi _-1 ). 4. The output (P) is changed after the next air value (A _{i + 1} ) and / or the next fuel value (F _{i + 1} ) or the next auxiliary value (H _{i + 1} ) are obtained. In this case, the air flow rate and / or the fuel flow rate and / or the auxiliary drive are respectively at maximum or minimum (P _max , P ₀ ) when the burner output is at the maximum or minimum, and / or the displacement of the auxiliary drive. Method according to claim 1 or 2, characterized in that the value of the quantity is varied along the direction of maximum or minimum ( _Rx , _Ro ). 5. A combustion value having a predetermined allowable range is used as the predetermined exhaust gas value. When the combustion value exceeds or falls below an upper limit value or a lower limit value of the predetermined allowable range of the combustion value, the next fuel value (F _{i + 1} ) Or the next air value (A _{i + 1} ) or auxiliary value (H
_5. The method according to claim _{1, wherein i + 1} ) is determined. 6. The characteristic curve of the burner (1) is determined by successively joining individual sections consisting of linear sections of individual air values and fuel values or auxiliary values. The method according to any one of claims 1 to 4. 7. A predetermined characteristic along the adjusted characteristic curve.
Output value (P_i) And the specified exhaust gas value is obtained again.
As the new air value (A_{i *}) And / or fuel value (F
_{i *}) Or auxiliary value (H_{i *}) Is required, in which case this new
New air value (A _{i *}) And / or fuel value (F_{i *}) Or supplement
Auxiliary value (H_{i *}) To adjust or reset the characteristic curve
The method according to any one of claims 1 to 6, wherein
the method of. 8. Moving along the adjusted characteristic curve to a predetermined output value (P _i ), based on the air value (A _i ) and / or the fuel value (F _i ) or the auxiliary value (H _i ). 7. The method as claimed in claim 1, wherein a new output value (P _{i *} ) is determined by means of this and is used to adjust or reset the characteristic curve. 9. A method according to claim 6, wherein the predetermined characteristic curve is set along the characteristic curve after the adjustment.
Output value (P_i) And the specified exhaust gas value is obtained again.
As the new air value (A_{i *}) And / or fuel value (F
_{i *}) Or auxiliary value (H_{i *}) Is required, in which case this new
New air value (A _{i *}) And / or fuel value (F_{i *}) Or supplement
Auxiliary value (H_{i *}) Using the new output value (P _{i *})
2. The method according to claim 1, wherein the sex curve is adjusted or reset.
7. The method according to any one of claims 1 to 6. 10. The apparatus according to claim 1, wherein the air adjusting member for adjusting the air flow rate, the fuel adjusting member for adjusting the fuel flow rate, or the auxiliary driving device are each changed at a predetermined speed. Or the method of claim 1. 11. The air-conditioning member, the fuel-conditioning member or the auxiliary driving device has different speeds and outputs (P)
When changing the air flow rate and / or the fuel flow rate and / or
11. The method according to claim 10, wherein the auxiliary drive is changed at a speed corresponding to the slope of the respective characteristic curve.