KR102472840B1 - Method for designing buck stay of refractory for coke oven - Google Patents

Abstract

The present invention relates to a method for designing a refractory support structure of a coke oven, comprising the steps of specifying operating boundary conditions, physical properties and design variables of a refractory, inputting a target expansion amount and allowable stress of the refractory support structure, and design variables. Entering the range of, setting a case by combining the input values, deriving an output value of the design variable through calculation of the thermal expansion of the case, selecting an optimal value of the design variable, and target expansion amount It is characterized in that it comprises the step of deriving the optimal design value by determining whether the stress value is satisfied. Therefore, by designing a buckstay for supporting a refractory in a coke oven using parameter optimization, the amount of overdesigned springs can be reduced compared to existing design methods, and thus the configuration of a refractory support structure including a buckstay can be reduced. It provides the effect of reducing the investment cost of the coke oven by optimizing the specifications of the buckstay.

Description

Design method of refractory support structure of coke oven {METHOD FOR DESIGNING BUCK STAY OF REFRACTORY FOR COKE OVEN}

The present invention relates to a method of designing a refractory support structure of a coke oven, and more particularly, to a refractory material of a coke oven for designing a buckstay as a refractory support structure that protects the refractory material from high-temperature thermal expansion of the oven refractory material producing coke. It relates to the design method of support structures.

In general, as a refractory support structure of a coke oven, a buskstay has a beam structure that supports the entire oven structure, and tie-rods that fix the buskstays on both sides are at the top and bottom It consists of a number of springs that allow the thermal expansion of the oven refractory.

As shown in FIGS. 3 to 6, the indirect heat exchange space for carbonizing coal into coke is a carbonization chamber, and there are combustion chambers on both sides of the carbonization chamber, and a total of 60 carbonization chambers are configured in the oven scale, , At this time, there are a total of 122 buckstays supported on both sides, 14 springs per buckstay, and 4 tie-rods.

To simply define the process of producing coke, it is a process of carbonizing coal in a coke oven and changing it into a fixed carbon mass (80-94%).

The coke oven used at this time is composed of the equipment shown in FIG. Combustion gas is injected through the pipes of ⑦ raw gas pipe 2 (mixed gas main) and ⑧ raw gas pipe 1 (COG main), and after being preheated in ④ heat storage chamber, it is burned in ⑥ combustion chamber.

The combustion heat generated in this process supplies the heat source to the carbonization chamber in an indirect heating method, and the coal entering the carbonization chamber through ① the coal inlet is carbonized as coke and ③ opens the oven door. The exhausted and burned gas is discharged through the ⑨ waste gas flue.

Since the carbonization chamber in which coal is carbonized into coke is composed of refractory bricks that can withstand high temperatures of 1,000℃ to 1,300℃ or more, a ② refractory bracing system is used to disperse and control the expansion force of the oven refractory. In this refractory support structure (bracing system), a buckstay is configured to maintain the outer wall structure while allowing expansion of the refractory, and a beam structure necessary for the role of the buckstay, It consists of a tie-rod and a number of springs.

As shown in FIGS. 4 to 6, the refractory support structure includes a WPP (Wall Protection Plate) in contact with the combustion chamber refractory and a buckstay that secures structural safety while allowing some expansion of the refractory (consisting of a plurality of springs) It consists of

Expansion of the refractory by combustion gas, thermal behavior and deformation of WPP (Wall Protection Plate), and a number of springs installed on the buckstay offset the thermal expansion force with spring stiffness while ensuring structural stability. do.

In the conventional design, a method of repeatedly applying the existing design to the rigidity of a tie-rod composed of a buckstay and a plurality of springs arranged up and down has been used, which is It was not a design that could respond to the change in thermal composition of the combustion chamber according to

The problem that can occur in such a design is that the thermal expansion amount of the refractory changes according to the refractory type change, and the thermal expansion amount changes. There was a problem that could lead to

In addition, the design of the buckstay of the refractory support structure of the conventional coke oven affects the operation and lifespan of the coke oven equipment, and also affects the required production volume of coke, which is a problem in the subsequent process. There was a problem.

Republic of Korea Patent Registration No. 10-0897754 [0010] (May 15, 2009) Republic of Korea Patent No. 10-1505161 (March 23, 2015) Republic of Korea Patent No. 10-1762822 (July 28, 2017)

The present invention has been devised to solve the above conventional problems, and by designing a buckstay for supporting a coke oven refractory using variable optimization, the amount of overdesigned springs is reduced compared to conventional design methods, and the resulting buckstay It is an object of the present invention to provide a design method of a refractory support structure of a coke oven capable of reducing the configuration of a refractory support structure including, and reducing the investment cost of a coke oven by optimizing the specifications of a buckstay.

In addition, the present invention analyzes the correlation between the stiffness parameters of the tie rod and the spring composed of the buckstay using a variable optimization technique, and determines the stiffness and longitudinal direction of the tie rod corresponding to the expansion amount and stress value of the buckstay, which are target values. Another purpose is to provide a design method for a refractory support structure of a coke oven that can minimize the amount and cost of springs compared to the existing design method for buckstays by deriving the optimal value of the stiffness of a number of springs. do.

The present invention for achieving the above object is a buckstay installed in the front and rear directions of the refractory of the coke oven as a refractory support structure of the coke oven, a plurality of springs and tie rods installed in the vertical direction ( A design method of a refractory support structure of a coke oven in which a multivariate combination design of a tie-rod is performed by a computer system, comprising: specifying operating boundary conditions of the coke oven and physical properties and design variables of the refractory; inputting a target expansion amount and allowable stress of the refractory support structure, which are objective functions; inputting the range of each design variable of the refractory support structure; Setting a case by combining input values between the operational boundary conditions and design variables; Deriving an output value of a design variable through thermal expansion calculation of the set case; selecting optimal values of design variables based on the derived output values; and deriving an optimal design value by determining whether the target expansion amount and stress value of the refractory support structure are satisfied.

The step of designating the operational boundary conditions of the present invention is characterized in that the combustion temperature of the oven refractory combustion chamber, the coke temperature of the carbonization chamber, and the atmospheric temperature of the external atmosphere are input.

The step of designating the design variables of the present invention is characterized in that design variables of a plurality of springs and tie-rods installed in the vertical direction of the buckstay are designated.

The step of inputting the range of the design variable of the present invention is characterized by inputting the stiffness range of a plurality of springs and tie-rods.

The step of setting the case of the present invention is characterized in that the case is set by combining the input values between the operating boundary condition and the design variable by a central composite planning method.

In the step of selecting the optimum value of the present invention, based on the expansion amount and stress value of the buckstay derived in the step of deriving the output value, a plurality of springs and tie-rods are selected. It is characterized in that each optimal design value is selected.

As described above, the present invention designs a buckstay for supporting a refractory in a coke oven using variable optimization, thereby reducing the amount of springs that are overdesigned compared to existing design methods, and thus constructing a refractory support structure including a buckstay. can be reduced, and by optimizing the specifications of the buckstay, it provides the effect of reducing the investment cost of the coke oven.

In addition, by using the variable optimization technique, the correlation between the stiffness variables of the tie rod and the spring composed of the buckstay is analyzed, and the stiffness of the tie rod that meets the target value, the expansion amount and stress value of the buckstay, and the number of longitudinal By deriving the optimal value of spring stiffness, it provides an effect that can minimize the quantity and cost of spring compared to the existing design method for buckstay.

1 is a schematic flow chart schematically showing a design method of a refractory support structure of a coke oven according to an embodiment of the present invention.
2 is a detailed flowchart showing a design method of a refractory support structure of a coke oven according to an embodiment of the present invention.
3 to 6 are configuration diagrams showing a refractory support structure of a coke oven according to an embodiment of the present invention.
7 is a graph showing a case setting step of a design method of a refractory support structure of a coke oven according to an embodiment of the present invention.
8 is a graph showing an output value derivation step of a design method of a refractory support structure of a coke oven according to an embodiment of the present invention.
9 and 10 are state diagrams showing the expansion state of the refractory and the state of the refractory support structure of the coke oven according to an embodiment of the present invention.
11 is a state diagram showing a behavior sequence of a bracing system according to thermal expansion of a refractory material of a coke oven according to an embodiment of the present invention.
12 and 13 are state diagrams showing the stress state of the optimal design of the initial design of the design method of the refractory support structure of the coke oven according to an embodiment of the present invention.
14 to 16 are state diagrams illustrating an example of a design method of a refractory support structure of a coke oven according to an embodiment of the present invention.

Hereinafter, a preferred embodiment of the present invention will be described in more detail with reference to the accompanying drawings.

1 is a schematic flowchart schematically showing a design method of a refractory support structure of a coke oven according to an embodiment of the present invention, and FIG. 2 is a schematic flowchart showing a design method of a refractory support structure of a coke oven according to an embodiment of the present invention. 3 to 6 are configuration diagrams showing a refractory support structure of a coke oven according to an embodiment of the present invention, and FIG. 7 is a design method of a refractory support structure of a coke oven according to an embodiment of the present invention. 8 is a graph showing a case setting step, and FIG. 8 is a graph showing an output value derivation step of a design method for a refractory support structure of a coke oven according to an embodiment of the present invention, and FIGS. Figure 11 is a state diagram showing the expansion state of the refractory of the coke oven and the state of the refractory support structure, Figure 11 is a state diagram showing the behavior sequence of the bracing system according to the thermal expansion of the refractory of the coke oven according to an embodiment of the present invention 12 and 13 are state diagrams showing the stress state of the optimal design of the initial design of the design method of the refractory support structure of the coke oven according to an embodiment of the present invention, and FIGS. 14 to 16 are one embodiment of the present invention. It is a state diagram showing an example of the design method of the refractory support structure of the coke oven according to the example.

The support structure of the refractory of the coke oven of the present invention relates to a buskstay among bracing systems for the refractory that disperses the expansion of the refractory in the combustion chamber of the oven and helps the stable operation of the coke oven equipment.

As shown in FIGS. 1, 2, and 14 to 16, the design method of the refractory support structure of the coke oven according to the present embodiment includes a variable designation step (S10), an expansion amount and allowable stress input step (S20), It includes a design range input step (S30), a case setting step (S40), an output value derivation step (S50), an optimal value selection step (S60), a correlation analysis step (S70), and an optimal design value derivation step (S80). , As a refractory support structure of a coke oven, a multi-variable combination design of a Buckstay installed in the front and rear directions of the refractory of the coke oven and a plurality of springs and tie-rods installed in the vertical direction As a method of designing a refractory support structure of a coke oven performed by a computer system, it is a method of designing a buckstay that protects a refractory material from high temperature thermal expansion of a refractory material of a coke oven that produces coke.

The variable designation step (S10) is a step of designating the operating boundary conditions of the coke oven and the physical properties and design variables of the refractory, which is inputting the high-temperature condition inside the combustion chamber of the oven (S11) and inputting the thermal expansion coefficient of the refractory in the combustion chamber. It consists of step S12.

In the step of inputting the high-temperature condition inside the oven combustion chamber (S11), the operation boundary condition of the coke oven is designated by inputting the combustion temperature of the oven refractory combustion chamber, the coke temperature of the carbonization chamber, and the atmospheric temperature of the external atmosphere.

In step S12 of inputting the thermal expansion coefficient of the refractory in the combustion chamber, as shown in FIG. 9 , the thermal expansion coefficient of the first to third refractories in the combustion chamber of the coke oven is input.

In addition, in the step of designating design variables, design variables of a plurality of springs and tie-rods installed in the vertical direction of the buckstay as a refractory support structure of the coke oven are designated.

The expansion amount and allowable stress input step (S20) is a step of inputting the target expansion amount and allowable stress of the refractory support structure, which is an objective function, as a refractory support structure of a coke oven. Buckstay and tie-rod ), enter the target expansion amount and allowable stress.

The design range input step (S30) is a step of inputting the range of each design variable of the refractory support structure, and inputs the stiffness range of a plurality of springs and tie-rods as the refractory support structure of the coke oven. will do

The design range input step (S30) includes inputting the stiffness range of the upper tie-rod (S31) and inputting the stiffness range of the lower tie-rod (S32); It consists of a step (S33) of inputting the stiffness range of the longitudinal spring (Spring).

The case setting step (S40) is a step of setting a case by combining the input values between the operating boundary conditions specified in the variable designation step (S10) and the design variables input in the design range input step (S30), and the operating boundary conditions and A case is set by combining the input values between the design variables by the central composite programming method.

In this case setting step (S40), an application case between design variables using CCD (Central Composite Design), which is a representative design method of response surface design (RSD), is set.

The output value derivation step (S50) is a step of deriving the output value of the design variable through the thermal expansion calculation of the case set in the case setting step (S40), and also, the case configured in FIG. By performing thermal expansion analysis, the response surface according to the design variable combination is derived as shown in FIG. 8.

The optimal value selection step (S60) is a step of selecting the optimal value of the design variable based on the output value derived in the output value derivation step (S50), and the step of confirming the target expansion amount of the Buckstay (S61) and It consists of checking the target stress value of the buckstay (S62) and checking the target stress value of the tie-rod (S63).

The response surface analysis method RSD used in the case setting step (S40), the output value derivation step (S50), and the optimal value selection step (S60) is an input variable X (design variable in the present invention), an output variable Y (objective function in the present invention As one of the DOE (Design Of Experiments), a design of experiment (DOE) used when the relationship between ) has a quadratic curve relationship, in the case setting step (S40) of the present invention, the central synthetic programming method CCD that performs an experiment at the level shown in FIG. (Central Composite Design) is preferred.

The central composite programming method is an experiment consisting of a center point, a cube point, and an axial point, and is an experimental method that can identify the curvature effect on the response surface (surfacing the value of the output variable Y). to be.

For example, the stiffness of the S1 spring, which is one of the ranges of design variables input in the design range input step (S30), is set from 300 N/mm to 400 N/mm, and the stiffness of the tie-rod is set to 1,000 N/mm. Assuming that N/mm is specified as 2,000 N/mm, the combination of the case of design variables to construct the response surface (output variable Y, Busckstay expansion amount in the present invention) is shown in Figure 7 below by the central composite programming method. is composed as

In addition, in the output value derivation step (S50), the response surface according to the design variable combination is derived as shown in FIG. 8 by performing thermal expansion analysis on the case of the case setting step (S40) configured in FIG. 7.

In the above example, two design variables were dealt with, and in the present invention, the stiffness of the upper and lower tie-rods and the stiffness of the spring for each position in the longitudinal direction were selected, and about 20 design variables were selected using the central composite planning method. Case) and use the response surface analysis method to derive the optimal value of the design variable that meets the objective function (buckstay expansion amount and generated stress).

The correlation analysis step (S70) is a step of analyzing the correlation between the design variables selected in the optimal value selection step (S60), and determining whether the target expansion amount of the objective function buckstay (ckstay) is satisfied (S71) and a step of determining whether the target stress value of buckstay, which is an objective function, is satisfied (S72), and if the expansion amount and stress value of buckstay do not satisfy the target value, an optimal value selection step (S60) will give feedback again.

The optimal design value derivation step (S80) is a step of deriving an optimal design value based on the result of determining whether the target expansion amount and stress value of the refractory support structure are satisfied in the correlation analysis step (S70), and the output value derivation step (S50 ) Based on the results determined in the correlation analysis step (S70) of the buckstay expansion and stress values, the optimal design values of the plurality of springs and tie-rods are selected, respectively. will do

11 shows the behavior sequence of the initial installation of the coke oven, the refractory expansion according to thermal expansion, and the bracing system, and the behavior sequence is as follows.

The first expansion of the refractory material is that the refractory material expands in the direction of the WPP (Wall Protection Plate) by the combustion heat of the combustion chamber, and the second is that the WPP moves in the direction of the busckstay. is to hold the evenly.

The third is to partially fix the expansion pressure of the refractory with the compression force of the S12 spring. At this time, the spring is compressed as much as the compression margin, and the expansion pressure greater than the compression force is transmitted to the Busckstay.

The fourth is to move the buckstay by the expansion pressure transmitted by the S12 spring, and the fifth is to share a certain portion of the expansion pressure of the refractory material with the compression force of the S1 and 2 springs, and the buckstay This is the order of being compressed by the movement amount of .

Finally, the sixth step is to avoid the stress concentration of the buckstay by adjusting the fixed part of the tie-rod when it moves more than the compression margin of S1 and 2, and the operator's intervention is required at this step. .

As an embodiment of the invention, as shown in Table 1 and FIG. 12, the stress of the buckstay of the original design is 120 MPa and based on the first designed buckstay spring, the optimal design of Table 2 and FIG. 13 The buckstay stress was 136 MPa and the specifications of the optimally designed buckstay spring were determined.

At the time of the initial design, the spring stiffness of the S12 spring group was equally applied at 607 N/mm, so the total compressive force sharing the refractory expansion force of the S12 spring group was 111.3 tonf. .8 The rigidity of the spring is optimized to 600N/mm and the rigidity of the S12.2 to S12.7 spring to 560N/mm.

At this time, the set variable is the stiffness of the S12.1 to S12.8 springs, and the objective function sets the compression force (or equivalent to the Buckstay target expansion amount) of the S12 spring group to 100 tonf or more, and the buckstay ( Buckstay) was set to 150 MPa or less.

The design of the optimized buckstay spring is determined by a combination of variables that satisfies the objective function, the total compressive force of the S12 spring group of 100 tonf or more, and the maximum generated stress of the buckstay satisfies the allowable stress of 150 MPa or less. It became.

Accordingly, it was found that the specification of the initially designed spring was optimized, resulting in a saving effect of about 7.7%, and a design that satisfies the operating specifications of the coke oven facility was derived.

As described above, according to the present invention, by designing a buckstay for supporting a refractory material of a coke oven using variable optimization, the amount of overdesigned springs is reduced compared to existing design methods, and the construction of a refractory support structure including a buckstay resulting therefrom can be reduced, and by optimizing the specifications of the buckstay, it provides the effect of reducing the investment cost of the coke oven.

In addition, by using the variable optimization technique, the correlation between the stiffness variables of the tie rod and the spring composed of the buckstay is analyzed, and the stiffness of the tie rod corresponding to the expansion and stress value of the buckstay, which is the target value, and the number of longitudinal By deriving the optimal value of spring stiffness, it provides the effect of minimizing the quantity and cost of springs compared to the existing design method for buckstays.

The present invention described above can be implemented in various other forms without departing from its technical spirit or main characteristics. Therefore, the above embodiments are mere examples in all respects and should not be construed in a limited manner.

Claims (6)

As a refractory support structure of a coke oven, a buckstay installed in the front and rear directions of the refractory of the coke oven and a plurality of springs and tie-rods installed in the vertical direction are designed by computer As a design method of a refractory support structure of a coke oven performed by the system,
Specifying the operational boundary conditions of the coke oven and the physical properties and design parameters of the refractory;
inputting a target expansion amount and allowable stress of the refractory support structure, which are objective functions;
inputting the range of each design variable of the refractory support structure;
Setting a case by combining input values between the operational boundary conditions and design variables;
Deriving an output value of a design variable through thermal expansion calculation of the set case;
selecting optimal values of design variables based on the derived output values; and
A method for designing a refractory support structure of a coke oven, comprising the steps of determining whether the target expansion amount and stress value of the refractory support structure are satisfied and deriving an optimal design value. According to claim 1,
Designating a refractory support structure for a coke oven, characterized in that the step of specifying the operating boundary condition inputs the combustion temperature of the oven refractory combustion chamber, the coke temperature of the carbonization chamber, and the ambient temperature of the external atmosphere. According to claim 1,
In the step of specifying the design variables, design variables of a plurality of springs and tie-rods installed in the vertical direction of the buckstay are specified. Refractory support structure of a coke oven design method. According to claim 1,
The step of inputting the range of design variables is a method of designing a refractory support structure of a coke oven, characterized in that by inputting a stiffness range of a plurality of springs and tie-rods. According to claim 1,
The step of setting the case is a method of designing a refractory support structure of a coke oven, characterized in that for setting the case by combining the input values between the operating boundary condition and the design variable by a central composite planning method. According to claim 1,
In the step of selecting the optimal value, the optimal design value of a plurality of springs and tie-rods based on the expansion amount and stress value of the buckstay derived in the step of deriving the output value Design method of a refractory support structure of a coke oven, characterized in that for selecting each.

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