KR101005833B1 - Method for optimizing shape of furnace - Google Patents

Abstract

Herein, a method of optimizing an incinerator shape for determining an optimal incinerator shape among several presented incinerator shapes is disclosed. The disclosed optimization method comprises the steps of: (a) calculating, for each incinerator shape, a plurality of physical quantity standard deviations; and (b) for each incinerator shape, each of the plurality of physical quantity standard deviations of the reference incinerator shape. Dividing each of the maximum physical quantity standard deviations to obtain a normalized plurality of physical quantity standard deviations, (c) for each incinerator shape, integrating each of the normalized physical quantity standard deviations of the normalized quantity in the incinerator length direction; (d) summing all the integrated physical quantity standard deviations of the plurality of integrated species to obtain a unified total standard deviation; and (e) of the incinerator shapes presented above, the shape of the incinerator having the smallest total standard deviation is optimal. Determining the shape of the incinerator.

Incinerator, Secondary, Combustion Chamber, Temperature, Speed, Species, Standard Deviation

Description

Optimization method of incinerator shape {METHOD FOR OPTIMIZING SHAPE OF FURNACE}

The present invention relates to a design technique of an incinerator, and more particularly, to a method of determining an optimal incinerator shape among various incinerator shapes when presented.

1 shows the general structure of a stocker incinerator. Referring to FIG. 1, the stocker type incinerator includes a primary combustion chamber 2, a secondary combustion chamber 4, and a boiler 6. The incinerator is also provided with an inlet 7 for waste, an outlet 8 for incineration ash, and an exhaust port 9 for combustion gas. The injected waste is sequentially processed via the primary combustion chamber 2 and the secondary combustion chamber 4. The incineration ash remaining after the treatment is discharged to the outside through the discharge port 8, and the combustion gas is discharged to the outside through the discharge port 9.

Conventionally, after determining the shape of an incinerator from the shape of an existing facility or based on empirical rules, the speed and temperature in an incinerator secondary combustion chamber for the purpose of verification or partial shape improvement of the determined incinerator shape. Evaluate the species concentration distribution. At this time, computational fluid dynamics analysis software is used to evaluate the velocity, temperature, and species concentration distributions. In other words, the conventional incinerator shape is evaluated from the results of the flow field analysis using the computational fluid dynamics analysis software, but was not utilized for the design of the incinerator shape.

As described above, in the related art, only a part of the shape of the incinerator which has been constructed and operated in the past has been changed, or only the shape of the incinerator has been determined based on empirical rules. Therefore, a systematic method for optimizing the design of the incinerator has not been proposed. Therefore, it is not possible to design the shape of the incinerator optimized according to the waste properties.

The inventors have evaluated the velocity, temperature and species concentration distributions in the incinerator secondary combustion chamber through the flow field analysis in the incinerator secondary combustion chamber using software for computational fluid analysis, and analyzed the incinerator shape and combustion from the analysis of the evaluation results. It was proposed to determine the method of supplying the air.

By uniformly designing the velocity distribution in the secondary combustion chamber, it is possible to minimize the size of the recycle zone in the secondary combustion chamber and to reduce the amount of carryover of dust.

By uniformly designing the temperature distribution in the secondary combustion chamber, it is possible to minimize the incomplete combustion region by equalizing the combustion region in the secondary combustion chamber.

By uniformizing the chemical species (eg, oxygen) concentration distribution in the secondary combustion chamber, the combustion in the secondary combustion chamber can be made uniform.

By uniformizing the combustion zone in the secondary combustion chamber, contaminants such as CO due to incomplete combustion can be minimized.

However, it is difficult to find a shape that is uniform in velocity, temperature, and species concentration distribution for various incinerator shapes.

Accordingly, the technical problem of the present invention is a method of determining an optimal incinerator shape in which physical quantity distributions such as velocity, temperature and species concentration distribution can be uniform among various presented incinerator shapes when presented. To provide.

Another technical problem of the present invention is to provide a method for determining an optimal incinerator shape in which all of the velocity, temperature and species (particularly oxygen) concentration distributions are uniform when several incinerator shapes are presented.

According to one aspect of the present invention, there is provided an incinerator shape optimization method for determining an optimal incinerator shape among several presented incinerator shapes. The optimization method includes the steps of: (a) calculating a plurality of physical quantity standard deviations for each incinerator shape, and (b) for each incinerator shape, each of the plurality of physical quantity standard deviations in the reference incinerator shape. Dividing each of the maximum physical quantity standard deviations to obtain a normalized plurality of physical quantity standard deviations, (c) for each incinerator shape, integrating each of the normalized physical quantity standard deviations of the normalized quantity in the incinerator length direction; (d) summing all the integrated physical quantity standard deviations of the plurality of integrated species to obtain a unified total standard deviation; and (e) of the incinerator shapes presented above, the shape of the incinerator having the smallest total standard deviation is optimal. Determining the shape of the incinerator.

Preferably, the physical quantities of the plurality of species may include at least two or more of fluid velocity, temperature, and chemical species concentration in the secondary combustion chamber of the incinerator, more preferably, each of the plurality of physical quantities of the incinerator Fluid velocity, temperature and species concentration in the secondary combustion chamber. At this time, the chemical species concentration is preferably oxygen concentration.

Preferably, in step (b), the incinerator having the smallest standard deviation with respect to the corresponding physical quantity is selected.

Preferably, the step (a) may calculate the physical quantity distributions in the secondary combustion chamber of the corresponding second incinerator through the flow field analysis for each incinerator shape, and calculate the standard deviations of the plurality of physical quantities from the physical quantity distributions, respectively. have.

According to another aspect of the present invention, a method for optimizing an incinerator shape for determining an optimal incinerator shape among several presented incinerator shapes is provided. The method comprises the steps of: (A) calculating the standard deviation of physical quantities for each incinerator shape; and (B) for each incinerator shape, the physical quantity standard deviation is normalized by dividing the standard quantity by the maximum standard deviation of the reference incinerator shape. Obtaining a physical quantity standard deviation, (C) integrating each of the normalized physical quantity standard deviations in the incinerator longitudinal direction with respect to each incinerator shape, and (D) the shape of the incinerator having the smallest integrated physical quantity standard deviation Determining the optimal incinerator shape.

In this case, the physical quantity is preferably any one of the fluid velocity, temperature and chemical species concentration in the secondary combustion chamber of the incinerator, the chemical species concentration is preferably oxygen concentration, the reference incinerator of step (B) Incinerators with the smallest standard deviation with respect to physical quantities are selected. In the step (A), it is preferable to calculate the physical quantity distribution in the secondary combustion chamber of the incinerator through the flow field analysis for each incinerator shape, and calculate the standard deviation of the physical quantity from the physical quantity distribution.

Conventionally, in contrast to changing the shape of the incinerator, which has been constructed and operated in the past, or determining the shape of the incinerator based on empirical rules, the present invention is to determine the shape of the incinerator having a uniform physical quantity among various presented incinerator shapes. In this regard, there is an advantage that quantitative evaluation and design of the optimum incinerator shape is possible. In particular, according to one embodiment of the present invention, it is possible to determine the optimum incinerator shape in which the velocity, temperature, and species species (particularly oxygen) concentration distribution of the flow field are all uniform.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. The following embodiments are provided as examples to ensure that the spirit of the present invention to those skilled in the art will fully convey. Accordingly, the present invention is not limited to the embodiments described below and may be embodied in other forms. And, in the drawings, the width, length, thickness, etc. of the components may be exaggerated for convenience. Like numbers refer to like elements throughout.

2 is a block flow diagram illustrating an optimization method of an incinerator shape according to an embodiment of the present invention.

Referring to FIG. 2, the method of the present embodiment includes calculating a plurality of physical quantity standard deviations (S1), normalizing the physical quantity standard deviations (S2), integrating the normalized physical quantity standard deviations (S3), and , A step S4 of integrated physical quantity standard deviations, and an optimal incinerator shape determination step S5.

At this time, the above steps S1, S2, S3 and S4 are performed for each of the various incinerator shapes presented. In step S4, the values obtained through all of the above steps S1, S2, and S3, that is, the standard deviation values obtained through successive calculations of the physical quantity standard deviation, normalization of the calculated physical standard deviations, and integration of the normalized physical standard deviations, are obtained. Summing up to find the single total standard deviation for each incinerator shape. By comparing the total standard deviations of the incinerator shapes and designing the incinerator shape with the smallest value, it is possible to find the optimum incinerator shape in which all physical quantities need to be considered.

In this embodiment, the physical quantities of the plurality of types described above are the velocity, temperature, and species concentration in the incinerator secondary combustion chamber. However, if one of the above three physical quantities does not need to be considered, that is, only speed and temperature, speed and species concentration, and temperature and species concentration can be used in the calculation. Here, it is preferable that a chemical species concentration is an oxygen concentration.

At this time, the computer system or apparatus used in the method for optimizing the incinerator shape, as shown in Figure 3, hydrodynamic analysis unit 11, standard deviation calculation unit 12, standard deviation normalization unit 13, integral A unit 14, a sum unit 15, and a determination unit 16 are included.

For example, the hydrodynamic analysis unit 11 may be used in step S1 to calculate a distribution of physical quantities to be obtained through flow field analysis for a given incinerator shape and air supply conditions. In addition, the standard deviation calculation unit 12 can be used together in the above step S1 to obtain the standard deviation of the physical quantity from the physical quantity distribution value. In addition, the standard deviation normalization unit 13 is used in the step S2, and divides the standard deviation of the physical quantities in the same unit calculated in the step S1 by the maximum physical quantity standard deviation described in detail below, and normalizes the physical quantity standard deviation. do. In addition, the integrating unit 14 is used in step S3 to integrate the normalized physical quantity standard deviation. In addition, the adder 15 is used in the step S4, and adds all the standard deviations of the physical quantity normalized and then integrated to obtain a single total standard deviation. In addition, the determination unit 16 is used in step S5, and determines the incinerator shape having the smallest total single standard deviation among the incinerator shapes as the optimum incinerator shape.

Hereinafter, each step described above will be described in more detail.

<S1: Calculating Standard Deviation of Multiple Kinds of Physical Quantity (Speed, Temperature, Species Concentration)>

For various incinerator shapes presented, a computational fluid dynamics analysis unit, ie, software for computational fluid dynamics analysis, is used to calculate the velocity, temperature and species concentration distributions within the incinerator. Next, for each incinerator shape, the standard deviations for speed, temperature and species are calculated according to each cross section inside the incinerator.

4 shows an example of calculating the standard deviation of velocity, temperature and species for a given incinerator shape.

In Figure 4, x represents the combustion gas flow direction. 4 shows an example of obtaining a speed standard deviation, a temperature standard deviation, and an oxygen concentration standard deviation as a species at a specific position in the secondary combustion chamber of the incinerator.

σ _{x, v} represents the standard deviation of the velocity (v) in the cross section of the x position, σ _{x, T} represents the standard deviation of the temperature (T) in the cross section of the x position, σ _{x, YO2} represents the cross section of the x position The standard deviation for the oxygen concentration (Y _O2 ) at.

The definition of velocity standard deviation is to find the square of the speed at the data position (n) of each section minus the average value of the velocity at that section, then take the square root and divide by the number of velocity data n used in the calculation. Indicates.

The definition of the temperature standard deviation is to find the square of the temperature at each data point (n) of the cross section minus the average value of the temperature at that cross section, then take the square root and divide by the number of velocity data n used in the calculation. Indicates.

The definition of the species species (oxygen, in this example) is the square of the species concentration (%) at the data position (n) of each cross section minus the average (%) of the species concentration at that cross section. After summation, we take the square root and divide it by the number n of data used in the calculation. As the chemical species, in addition to the oxygen concentration, as in the present embodiment, there may be a nitrogen oxide concentration, carbon monoxide concentration, etc., and an appropriate chemical species should be selected according to the incinerator. Since the chemical species of interest in the general incinerator is oxygen, oxygen was selected as the chemical species in this embodiment.

As shown in FIG. 5, the velocity standard deviation, the temperature standard deviation, and the oxygen concentration standard deviation are calculated for each of the various types of incinerator shapes (case 1, case 2, and case 3) presented as shown in FIG. 5.

< S2 : Physical quantity (speed, temperature, Chemical species  Normalization of Standard Deviations>

), 온도 표준편차(

) 및 산소농도 표준편차(

)를 각각 기준 소각로 형상의 최대 속도 표준편차(

), 최대 온도 표준편차(

), 최대 산소농도 표준편차(

)로 나누어, 위의 표준편차들을 정규화되며, 이에 의해, 정규화된 속도, 온도 및 산소농도의 표준편차들(

,

,

)이 구해진다.As shown in [Equation 1] below, the speed standard deviation obtained in the previous step S1 (

), Temperature standard deviation (

) And oxygen standard deviation (

) Is the maximum speed standard deviation (

), Maximum temperature standard deviation (

), Maximum oxygen concentration standard deviation (

), The above standard deviations are normalized, whereby the standard deviations of normalized rate, temperature and oxygen concentration (

,

,

) Is obtained.

), 최대 온도 표준편차(

), 최대 산소농도 표준편차(

)는 기준 소각로의 해당 물리량에 대한 최대 표준편차로서, 기준 소각로의 선정은 해당 물리량에 대하여 가장 작은 표준편차를 갖도록 이루어진다. At this time, the maximum speed standard deviation (

), Maximum temperature standard deviation (

), Maximum oxygen concentration standard deviation (

) Is the maximum standard deviation of the corresponding physical quantity of the reference incinerator, and the selection of the reference incinerator is made to have the smallest standard deviation of the corresponding physical quantity.

S3: Normalization of Normalized Standard Deviations

,

,

)이 아래의 [수학식 2]와 같이 해당 소각로의 길이방향으로 적분된다. 이에 따라, 속도, 온도 및 산소 농도의 적분된 표준편차(

,

,

)들이 각각 얻어진다. [수학식 2]에서 “L”은 소각로 2차 연소실의 입구부터 연소가스 흐름에 따라 2차 연소실 출구까지의 거리를 나타낸다.For each incinerator shape, the standard deviations of normalized velocity, temperature and oxygen concentration (

,

,

) Is integrated in the longitudinal direction of the incinerator as shown in [Equation 2] below. Accordingly, the integrated standard deviation of velocity, temperature and oxygen concentration (

,

,

) Are obtained respectively. In Equation 2, "L" represents the distance from the inlet of the incinerator secondary combustion chamber to the outlet of the secondary combustion chamber according to the combustion gas flow.

<S4, S5: Acquire Total Standard Deviation and Determine Optimal Incinerator Shape>

), 온도 표준편차(

), 및 산소농도 표준편차(

)가 아래의 [수학식 3]과 같이 합산되며, 이에 의해, 단일의 총 표준편차(

)이 구해진다.Next, for each incinerator shape, the velocity standard deviation integrated in the incinerator longitudinal direction (

), Temperature standard deviation (

), And standard deviation of oxygen concentration (

) Are summed as in Equation 3 below, whereby a single total standard deviation (

) Is obtained.

)는 해당 소각로 형상의 속도, 온도, 산소농도의 표준편차를 모두 대표한다. 그리고, 상기 단일의 총 표준편차가 작다는 것은 소각로 내의 속도, 온도, 산소농도가 균일하다는 것을 의미한다. The total standard deviation (

) Represents all the standard deviations of velocity, temperature and oxygen concentration of the incinerator shape. In addition, the small single standard deviation means that the velocity, temperature and oxygen concentration in the incinerator are uniform.

As described above, since the magnitude of the total standard deviation obtained for each incinerator shape is small, it means that the speed, temperature, and chemical species in the incinerator are uniform. Therefore, the optimal incinerator shape may be selected to have the smallest total standard deviation. .

Above, three physical quantities are considered: speed, temperature and species concentration. However, as introduced below, only two physical quantities may be considered.

For example, if you want to find the optimal condition of a device in which the same gas or liquid is supplied at different temperatures and mixed uniformly, the smallest sum of the normalized velocity and temperature standard deviation integrated for the given shapes is optimal. It becomes a shape. In other words, the standard deviation for the chemical species does not need to be considered because the same chemical species is targeted. This can be represented by Equation 4 below.

의 값 중에서 최소값을 갖는 형상을 최적의 형상으로 결정한다.In the above case, the number of shapes to be compared is m, in which case σ'1, σ'2, σ'3,

The shape having the minimum value among the values of is determined as the optimum shape.

According to a variant of the invention, only one physical quantity can be considered, for example, the integrated normalization for each given shape when obtaining the optimum conditions in a device that must maintain a single gas or liquid at a uniform rate. The smallest magnitude of the velocity standard deviation may be determined as the optimum shape.

 In this case, the method of determining the optimized incinerator shape is performed in the following order.

First, for each incinerator shape, the physical quantity standard deviation is calculated. The calculation method of the physical quantity standard deviation is the same as in the previous embodiment. However, only one physical quantity standard deviation is calculated. Next, for each incinerator shape, the normalized physical quantity standard deviation is obtained by dividing the physical quantity standard deviation by the maximum physical quantity standard deviation of the reference incinerator shape. The method of normalizing the physical quantity standard deviation is also the same as in the previous embodiment. Next, the shape of the incinerator having the smallest normalized physical quantity standard deviation is determined as the optimum incinerator shape. In this case, the physical quantity may be any one of the fluid velocity, temperature, and chemical species concentration in the secondary combustion chamber of the incinerator, but is preferably a speed.

1 shows a general structure of a stalker incinerator.

2 is a block flow diagram illustrating a method for optimizing an incinerator shape according to an embodiment of the present invention.

3 is a view for explaining an example of a computer system or apparatus used in the method for optimizing the incinerator shape.

4 shows an example of calculating the standard deviation of velocity, temperature and species for a given incinerator shape.

5 is a view showing an example of calculating the standard deviation for the speed, temperature, species for incinerators of various shapes.

Claims (11)

As an optimization method of incinerator shape to determine the optimal incinerator shape among several presented incinerator shapes, (a) calculating, for each incinerator shape, a plurality of physical quantity standard deviations (S1); (b) obtaining, for each incinerator shape, a normalized plurality of physical quantity standard deviations by dividing each of the plurality of physical quantity standard deviations by the maximum physical quantity standard deviations of the reference incinerator shape respectively; (c) for each incinerator shape, integrating each of the normalized plurality of physical quantity standard deviations in the incinerator longitudinal direction (S3); (d) adding all of the integrated plurality of physical quantity standard deviations to obtain a unified total standard deviation (S4); And (e) determining the shape of the incinerator having the smallest total standard deviation among the presented incinerator shapes as an optimal incinerator shape. The method according to claim 1, wherein the physical quantity of the plurality of species comprises at least two or more of the fluid velocity, temperature and chemical species concentration in the secondary combustion chamber of the incinerator. The method of claim 1, wherein each of the plurality of physical quantities is a fluid velocity, a temperature, and a chemical concentration in the secondary combustion chamber of the incinerator. The incinerator shape optimization method according to claim 2 or 3, wherein the chemical species concentration is oxygen concentration. The method according to claim 1, wherein in the step (b), the reference incinerator is selected incinerator having the smallest standard deviation with respect to the physical quantity is selected. The method of claim 1, wherein the step (a) calculates the physical quantity distributions in the secondary combustion chamber of the corresponding second incinerator through flow field analysis for each incinerator shape, and calculates a plurality of standard deviations of the physical quantity from the physical quantity distributions, respectively. Optimization method of the incinerator shape, characterized in that. As an optimization method of incinerator shape to determine the optimal incinerator shape among several presented incinerator shapes, (A) for each incinerator shape, calculating a physical quantity standard deviation; (B) for each incinerator shape, obtaining a normalized physical quantity standard deviation by dividing the physical quantity standard deviation by the maximum physical quantity standard deviation of the reference incinerator shape; (C) determining the shape of the incinerator having the smallest normalized physical quantity standard deviation as an optimal incinerator shape. The method according to claim 7, wherein the physical quantity is any one of the fluid velocity, temperature and species concentration in the secondary combustion chamber of the incinerator. The method of claim 8, wherein the chemical species concentration is oxygen concentration. The method according to claim 7, wherein in the step (B), the reference incinerator is an incinerator shape optimization method characterized in that the incinerator having the smallest standard deviation with respect to the physical quantity is selected. The incinerator according to claim 8, wherein the step (A) calculates the physical quantity distribution in the secondary combustion chamber of the incinerator through the flow field analysis for each incinerator shape, and calculates the standard deviation of the physical quantity from the physical quantity distribution. How to optimize the shape.

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