TWI747774B - Method for estimating an outlet temperature of a finishing mill - Google Patents

Abstract

A method for estimating an outlet temperature of a finishing mill is provided. The method includes the following steps: subtracting a theoretical outlet temperature from an actual outlet temperature to obtain a learned compensation value; at a plurality of positions between an inlet of the finishing mill and an outlet of the finishing mill, obtaining actual temperatures and theoretical temperatures respecting to the positions; subtracting the theoretical temperatures from the actual temperatures to which they respecting to obtain a plurality of position compensation values; summing the position compensation values multiplied by position weighting values corresponding to the position compensation values and the learned compensation value multiplied by a learning weighting value to obtain a corrected compensation value; and summing the theoretical outlet temperature and the corrected compensation value to obtain an estimating outlet temperature of the finishing mill.

Description

Estimation method of finishing mill outlet temperature

The present invention relates to a temperature estimation method, especially a method for estimating the exit temperature of a finishing mill.

In the finishing rolling process in the steelmaking industry, the exit temperature of the finishing mill will directly affect the quality of the rolled steel. In the existing technology, the theoretical model/physical model of the finishing rolling is often used to pre-estimate the exit temperature of the finishing rolling mill with working parameters. Then it compares and learns with the actual outlet temperature in the process and generates a compensation value, and then adjusts the working parameters through the compensation value so that the estimated outlet temperature can be close to the actual outlet temperature, thereby maintaining the accuracy of the estimated outlet temperature.

However, the prior art requires multiple steel coils or multiple batches to compare and learn to obtain an accurate compensation value, thereby reducing the error between the estimated finishing mill exit temperature and the actual exit temperature. In other words, when the steel material/specification (such as width, thickness) changes or the manufacturing process changes, because the finishing mill is still in the comparative learning stage for the first few batches of products, the actual exit temperature will be different from the estimated exit temperature of the finishing mill. Because of the large error, the rolling quality/specification of the first few batches of products will not meet the requirements and need to be rejected. As a result, comparing the energy consumed during the learning phase and rejecting products directly lead to an increase in production costs.

Therefore, it is necessary to provide a method for estimating the exit temperature of the finishing mill to solve the problems of the conventional technology.

The purpose of the present invention is to provide a method for estimating the exit temperature of a finishing mill, which can speed up the comparison and learning, so that the error between the actual exit temperature and the estimated exit temperature of the finishing mill in the same batch can be quickly converged, thereby maintaining the rolling quality And reduce the number of rejected steel coils.

In order to achieve the above objective, the present invention provides a method for estimating the exit temperature of a finishing mill, which includes the following steps: subtracting a theoretical exit temperature from an actual exit temperature to obtain a learned compensation value; At a plurality of positions between the exits of the rolling mill, obtain the respective actual temperatures and respective theoretical temperatures of these positions; subtract the respective theoretical temperatures from the respective actual temperatures of these positions to obtain the plurality of positions corresponding to these positions respectively Compensation value; each position compensation value is respectively multiplied by a corresponding position weight value and added with the learned compensation value multiplied by a learning weight value to obtain a corrected compensation value; and sum the theoretical outlet temperature and A corrected compensation value to obtain an estimated value of the exit temperature of the finishing mill.

In an embodiment of the present invention, the sum of the position weight values and the learning weight value is 1.

In an embodiment of the present invention, the positions include: a first position and a second position.

In an embodiment of the present invention, obtaining the respective actual temperatures and respective theoretical temperatures of the locations includes: using a first temperature sensor disposed at the first location to obtain the actual temperature of a first location; and using A second temperature sensor arranged at the second location obtains an actual temperature of the second location.

In an embodiment of the present invention, obtaining the respective actual temperatures and respective theoretical temperatures of the locations further includes: using a temperature physical model with at least one working parameter to calculate a first location theoretical temperature and a second location theoretical temperature temperature.

In an embodiment of the present invention, subtracting the respective theoretical temperatures from the respective actual temperatures of the positions to obtain the position compensation values corresponding to the positions respectively includes: subtracting the first position actual temperature from the first position A theoretical position temperature to obtain a first position compensation value; and the second position theoretical temperature is subtracted from the actual second position temperature to obtain a second position compensation value.

In an embodiment of the present invention, multiplying each position compensation value by the corresponding position weight value and adding the learned compensation value multiplied by the learning weight value to obtain the corrected compensation value includes: The first position compensation value is multiplied by a first position weight value, the second position compensation value is multiplied by a second position weight value, and the learned compensation value multiplied by the learned weight value is added to obtain the corrected compensation value.

In an embodiment of the present invention, the sum of the first position weight value, the second position weight value, and the learning weight value is 1.

The present invention also provides a method for estimating the exit temperature of a finishing mill, which includes the following steps: subtracting a theoretical exit temperature from an actual exit temperature to obtain a learned compensation value; At a first position, obtain an actual temperature of a first position and a theoretical temperature of a first position; subtract the actual temperature of the first position from the theoretical temperature of the first position to obtain a first position compensation value; The position compensation value multiplied by a first position weight value and the learned compensation value multiplied by a learning weight value are added to obtain a corrected compensation value; and the theoretical outlet temperature and a corrected compensation value are added to Obtain an estimate of the exit temperature of the finishing mill.

In an embodiment of the present invention, the sum of the first position weight value and the learned weight value is 1.

As mentioned above, the method for estimating the exit temperature of the finishing mill provided by the present invention obtains the actual temperature (for example, using a temperature sensor) and the theoretical temperature at multiple positions between the entrance of the finishing mill and the exit of the finishing mill, and calculates the respective values of these positions. Position compensation value. Subsequently, these position compensation values and the corresponding position weight values can make the error between the actual exit temperature and the estimated exit temperature of the finishing mill quickly converge, thereby maintaining the rolling quality and reducing the number of rejected coils.

In order to make the above and other objectives, features, and advantages of the present invention more obvious and understandable, the following will specifically cite the preferred embodiments of the present invention, together with the accompanying drawings, and describe in detail as follows. Furthermore, the directional terms mentioned in the present invention, such as up, down, top, bottom, front, back, left, right, inside, outside, side, surrounding, center, horizontal, horizontal, vertical, vertical, axial, The radial direction, the uppermost layer or the lowermost layer, etc., are only the direction of reference to the attached drawings. Therefore, the directional terms used are used to describe and understand the present invention, rather than to limit the present invention.

其中

是精軋機出口溫度估算值、

是理論出口溫度、

是鋼捲溫度補償值、

是批次溫度補償值。其中鋼捲溫度補償值

及批次溫度補償值

分別會通過下列數學式2來比對學習來提高補償值的精度： [數學式2]

其中是

是學習後補償值、

是實際出口溫度、

是理論出口溫度。 Please refer to Figure 1. Figure 1 is a schematic diagram of the comparison and learning process of the current technology finishing mill. The current technology will use the following mathematical formula 1 to estimate the exit temperature of the finishing mill: [Mathematical formula 1]

in

Is the estimated value of the exit temperature of the finishing mill,

Is the theoretical outlet temperature,

Is the coil temperature compensation value,

Is the batch temperature compensation value. Among them, the coil temperature compensation value

And batch temperature compensation value

The following mathematical formula 2 will be used to compare and learn to improve the accuracy of the compensation value: [Math 2]

Where is

Is the compensation value after learning,

Is the actual outlet temperature,

Is the theoretical outlet temperature.

及批次溫度補償值

分別進行比對學習。現行技術就需要經過較多的鋼捲及批次的學習來降低精軋機出口溫度估算值與實際出口溫度之間的誤差，這樣也使得在比對學習階段中的產品的軋延品質/規格多會不符合需求而遭到剔退。過多的剔退產品再加上學習階段中所消耗的能源都會直接導致生產成本的增加。 Because the actual outlet temperature is required for comparison and learning, plus the need to compensate for the coil temperature

And batch temperature compensation value

Compare and learn separately. The current technology needs to go through more steel coil and batch learning to reduce the error between the estimated value of the finishing mill exit temperature and the actual exit temperature, which also makes the rolling quality/specification of the product in the comparison learning stage more Will not meet the requirements and be rejected. Too many rejected products plus the energy consumed in the learning phase will directly lead to an increase in production costs.

Therefore, in order to make the error between the estimated value of the exit temperature of the finishing mill and the actual exit temperature quickly converge, so as to reduce the rejection of products and maintain the rolling quality. The invention provides a method for estimating the exit temperature of a finishing mill.

Please refer to FIGS. 2 and 3. FIG. 2 is a step-by-step flowchart of a method for estimating the exit temperature of a finishing mill according to an embodiment of the present invention, and FIG. 3 is an example of applying the embodiment in FIG. In Figure 3, a finishing mill 100 includes a finishing mill entrance temperature sensor 110 and a finishing mill exit temperature sensor 180, and the finishing mill entrance temperature sensor 110 and the finishing mill exit temperature sensor A first finishing roll set 115, a second finishing roll set 125, a third finishing roll set 135, a fourth finishing roll set 145, and a fifth finishing roll set 155 are arranged between the device 180. A sixth finishing roll set 165 and a seventh finishing roll set 175. The finishing mill inlet temperature sensor 110 is used to obtain an actual inlet temperature, and the finishing mill outlet temperature sensor 180 is used to obtain an actual outlet temperature. In addition, temperature sensors are provided at a plurality of positions between the temperature sensor at the entrance of the finishing mill and the exit of the finishing mill. For example, a first temperature sensor 120 is provided at a first position between the first finishing roll set 115 and the second finishing roll set 125, and a first temperature sensor 120 is provided between the second finishing roll set 125 and the second finishing roll set 125. A second temperature sensor 130 is provided at a second position between the three finishing roller sets 135, and a third temperature sensor 130 is provided at a third position between the third finishing roller set 135 and the fourth finishing roller set 145 A third temperature sensor 140, a fourth temperature sensor 150 is arranged at a fourth position between the fourth finishing roller set 145 and the fifth finishing roller set 155, and a fourth temperature sensor 150 is arranged at the fifth finishing roller set 145 A fifth temperature sensor 160 is provided at a fifth position between the roller set 155 and the sixth finishing roll set 165, and a fifth temperature sensor 160 is provided between the sixth finishing roll set 165 and the seventh finishing roll set 175 A sixth temperature sensor 170 is provided at the first six positions in the middle.

As shown in Figure 2, the method for estimating the exit temperature of the finishing mill provided by this embodiment includes the following steps.

其中是

是該學習後補償值、

是該實際出口溫度、

是該理論出口溫度。 In step S110, a theoretical outlet temperature is subtracted from an actual outlet temperature to obtain a learned compensation value. The actual outlet temperature and the theoretical outlet temperature can be obtained through temperature sensors installed at the entrance of the finishing mill and the exit of the finishing mill, respectively. It should be understood that the theoretical outlet temperature can be calculated based on a theoretical formula, and the theoretical outlet temperature can be calculated by a verified physical model. Therefore, step S130 may further include: using a temperature physical model with at least one working parameter to calculate the theoretical outlet temperature. In addition, step S130 may be presented as the following mathematical formula 3: [Mathematical formula 3]

Where is

Is the compensation value after the learning,

Is the actual outlet temperature,

Is the theoretical outlet temperature.

In step S120, at a plurality of positions between the entrance of a finishing mill and the exit of a finishing mill, the respective actual temperatures and respective theoretical temperatures of these positions are obtained.

In step S130, the actual temperature of the respective positions is subtracted from the respective theoretical temperature to obtain a plurality of position compensation values corresponding to the respective positions.

Step S140: Multiply each position compensation value by a corresponding position weight value and add the learned compensation value multiplied by a learning weight value to obtain a corrected compensation value.

Step S150, adding the theoretical outlet temperature and the corrected compensation value to obtain an estimated value of the finishing mill outlet temperature.

Taking FIG. 3 as an example, step S120 includes: using a first temperature sensor 120 arranged at the first position to obtain an actual temperature at a first position; using a second temperature sensor arranged at the second position Use the device 130 to obtain the actual temperature of a second location; use a third temperature sensor 140 set at the third location to obtain the actual temperature of a third location; use a fourth temperature sensor set at the fourth location To obtain an actual temperature at a fourth position; use a fifth temperature sensor 160 set at the fifth position to obtain an actual temperature at a fifth position; and use a sixth temperature sensor set at the sixth position The detector 170 is used to obtain an actual temperature at the sixth position. It should be understood that the first position, the second position, the third position, the fourth position, the fifth position, and the sixth position can also be adjusted according to different requirements, and they are not necessarily set on each finishing roll. Between wheels.

In addition, step S120 may also include: using a temperature physical model with at least one working parameter corresponding to each finishing roll set 115, 125, 135, 145, 155, 165, 175 to calculate a first position theoretical temperature, a The second position theoretical temperature, a third position theoretical temperature, a fourth position theoretical temperature, a fifth position theoretical temperature, and a sixth position theoretical temperature.

其中

是第

個位置的位置補償值、

是第

個位置的實際溫度、

是第

個位置的理論溫度，以及

為1至6。 Step S130 may include: subtracting the first position theoretical temperature from the first position actual temperature to obtain a first position compensation value; and subtracting the second position theoretical temperature from the second position actual temperature to obtain a first position Second position compensation value; the third position actual temperature is subtracted from the third position theoretical temperature to obtain a third position compensation value; the fourth position actual temperature is subtracted from the fourth position theoretical temperature to obtain a first Four position compensation value; the fifth position actual temperature is subtracted from the fifth position theoretical temperature to obtain a fifth position compensation value; and the sixth position actual temperature is subtracted from the sixth position theoretical temperature to obtain a The sixth position compensation value. Therefore, step S130 may present the following mathematical formula 4: [Mathematical formula 4]

in

Is the first

Position compensation value for each position,

Is the first

Actual temperature at each location,

Is the first

Theoretical temperature at each location, and

For 1 to 6.

其中

是各位置補償值、

是各位置權重值、

是該學習後補償值、

是該學習權重值，且

為1至6。此外，

與

的總和為1，且

在0至1之間。 Step S140 may include: multiplying the first position compensation value by a first position weight value, the second position compensation value by a second position weight value, and the third position compensation value by a third position weight value , The fourth position compensation value is multiplied by a fourth position weight value, the fifth position compensation value is multiplied by a fifth position weight value, the sixth position compensation value is multiplied by a sixth position weight value, and the result of the learning The compensation value is multiplied by the learning weight value and added to obtain the corrected compensation value. In addition, the sum of the first position weight value, the second position weight value, the third position weight value, the fourth position weight value, the fifth position weight value, the sixth position weight value and the learning weight value Is 1. The learning weight value is between 0 and 1. Therefore, step S140 may present the following mathematical formula 5: [Mathematical formula 5]

in

Is the compensation value of each position,

Is the weight value of each position,

Is the compensation value after the learning,

Is the learning weight value, and

For 1 to 6. also,

and

The sum of is 1, and

Between 0 and 1.

其中

是該精軋機出口溫度估算值、

是該理論出口溫度、

是該補償修正值。 Therefore, step S150 may present the following mathematical formula 6: [Mathematical formula 6]

in

Is the estimated value of the exit temperature of the finishing mill,

Is the theoretical outlet temperature,

Is the compensation correction value.

Please refer to Fig. 4a and Fig. 4b. Fig. 4a is a comparison diagram of the actual outlet temperature and estimated value of the outlet temperature in the prior art, and Fig. 4b is a comparison diagram of the actual outlet temperature and the estimated value of the outlet temperature according to the present invention. As shown in Figure 4a, the average value of the error between the actual exit temperature and the estimated value of the exit temperature using the prior art is 3.24, and the standard deviation is 10.88, and as shown in Figure 4b, the actual exit temperature and the exit temperature of the present invention are used The average error of the estimated value is 1.55, and the standard deviation is 9.7. That is to say, the error between the actual outlet temperature and the estimated value of the outlet temperature in the prior art is relatively large and the error range is relatively wide, while the error between the actual outlet temperature and the estimated value of the outlet temperature of the present invention is relatively small and the range is also relatively large. small. The embodiment of the present invention can quickly converge the error between the estimated value of the exit temperature of the finishing mill and the actual exit temperature, thereby reducing rejection of products and maintaining rolling quality.

Please refer to FIG. 5, which is a flow chart of a step of a method for estimating the exit temperature of a finishing mill according to another embodiment of the present invention. The method for estimating the exit temperature of the finishing mill provided by the embodiment in Fig. 5 includes the following steps.

In step S210, a theoretical outlet temperature is subtracted from an actual outlet temperature to obtain a learned compensation value. The actual outlet temperature and the theoretical outlet temperature can be obtained by temperature sensors arranged at the entrance of the finishing mill and the exit of the finishing mill, respectively. It should be understood that the theoretical outlet temperature can be calculated by a theoretical formula, or the theoretical outlet temperature can be calculated by using a verified temperature physical model with at least one working parameter. In addition, the working parameters may include an inlet temperature, a steel width, a thickness of the steel before finishing rolling, a thickness of the steel after finishing rolling, a finishing rolling speed, a water spray amount, and combinations thereof. Step S210 may also present the above-mentioned mathematical formula 3, which will not be repeated here.

Step S220, at a first position between an entrance of a finishing mill and an exit of a finishing mill, obtain an actual temperature at a first position and a theoretical temperature at a first position. For example, a temperature sensor is provided at the first location to obtain the actual temperature of the first location. In addition, the theoretical temperature of the first position can be obtained through a theoretical formula or a verified temperature physical model with at least one working parameter.

為1。 In step S230, the actual temperature of the first position is subtracted from the theoretical temperature of the first position to obtain a first position compensation value. Step S210 can also present the above-mentioned mathematical formula 4, the difference is only

Is 1.

數學式7與數學式5相似，兩者的差異僅在於

為1。 Step S240, adding the first position compensation value multiplied by a first position weight value and the learned compensation value multiplied by a learning weight value to obtain a corrected compensation value. In addition, the sum of the first position weight value and the learned weight value is 1. And step S240 can also present the following mathematical formula 7: [Mathematical formula 7]

Mathematical formula 7 is similar to Mathematical formula 5. The difference between the two is only

Is 1.

In step S250, the theoretical outlet temperature and the corrected compensation value are added to obtain an estimated value of the finishing mill outlet temperature. Step S250 may also present the above-mentioned Mathematical Formula 6, which will not be repeated here.

As mentioned above, the method for estimating the exit temperature of the finishing mill provided by the present invention obtains the actual temperature (for example, using a temperature sensor) and the theoretical temperature at multiple positions between the entrance of the finishing mill and the exit of the finishing mill, and calculates the respective values of these positions. Position compensation value. Subsequently, these position compensation values and the corresponding position weight values can make the error between the actual exit temperature and the estimated exit temperature of the finishing mill quickly converge, thereby maintaining the rolling quality and reducing the number of rejected coils.

Although the present invention has been disclosed in preferred embodiments, it is not intended to limit the present invention. Anyone familiar with the art can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the present invention The scope of protection shall be subject to the scope of the attached patent application.

100: Finishing mill 110: Finishing mill inlet temperature sensor 115: The first finishing roller set 120: The first temperature sensor 125: The second finishing roller set 130: second temperature sensor 135: The third finishing roller set 140: The third temperature sensor 145: The fourth finishing roller set 150: The fourth temperature sensor 155: Fifth finishing roller set 160: Fifth temperature sensor 165: The sixth finishing roller set 170: The sixth temperature sensor 175: The seventh finishing roller set 180: Finishing mill exit temperature sensor S110～S150: steps S210～S250: steps

Figure 1 is a schematic diagram of the comparison and learning process of the prior art finishing mill. Figure 2 is a step flow chart of a method for estimating the exit temperature of a finishing mill according to an embodiment of the present invention. Figure 3 is an example of applying the embodiment in Figure 2. Figure 4a is a comparison diagram of the actual exit temperature and the estimated exit temperature in the prior art. Figure 4b is a comparison diagram between the actual outlet temperature of the present invention and the estimated outlet temperature. Figure 5 is a step flow chart of a method for estimating the exit temperature of a finishing mill according to another embodiment of the present invention.

S110~S150: steps

Claims (8)

A method for estimating the exit temperature of a finishing mill, which includes the following steps: subtracting a theoretical exit temperature from an actual exit temperature to obtain a learned compensation value; at a plurality of positions between the entrance of a finishing mill and the exit of a finishing mill , Obtain the respective actual temperature and respective theoretical temperature of the positions; subtract the respective theoretical temperature from the respective actual temperature of the positions to obtain a plurality of position compensation values corresponding to the positions; Respectively multiply a corresponding position weight value and add to the learned compensation value multiplied by a learning weight value to obtain a corrected compensation value, wherein the sum of the position weight values and the learning weight value is 1; and The theoretical outlet temperature and the corrected compensation value are added together to obtain an estimated value of the finishing mill outlet temperature. The method for estimating the exit temperature of a finishing mill according to claim 1, wherein the positions include: a first position and a second position. The method for estimating the exit temperature of a finishing mill according to claim 3, wherein obtaining the respective actual temperatures and respective theoretical temperatures of the positions includes: using a first temperature sensor arranged at the first position to obtain a first temperature sensor. Actual temperature of the location; and using a second temperature sensor set at the second location to obtain an actual temperature of the second location. The method for estimating the exit temperature of the finishing mill as described in claim 4, wherein obtaining the respective actual temperatures and respective theoretical temperatures of the positions further includes: A temperature physical model and at least one working parameter are used to calculate a theoretical temperature at a first position and a theoretical temperature at a second position. The method for estimating the exit temperature of the finishing mill as described in claim 5, wherein the actual temperature of the respective positions is subtracted from the respective theoretical temperature to obtain the position compensation values corresponding to the respective positions, including: the first position The actual temperature is subtracted from the theoretical temperature of the first position to obtain a first position compensation value; and the actual temperature of the second position is subtracted from the theoretical temperature of the second position to obtain a second position compensation value. The method for estimating the exit temperature of a finishing mill according to claim 6, wherein each position compensation value is respectively multiplied by the corresponding position weight value and added to the learned compensation value multiplied by the learning weight value to obtain the correction The post-compensation value includes: multiplying the first position compensation value by a first position weight value, the second position compensation value multiplied by a second position weight value, and the post-learning compensation value multiplied by the learning weight value and added, To obtain the corrected compensation value. The method for estimating the exit temperature of a finishing mill according to claim 7, wherein the sum of the first position weight value, the second position weight value, and the learned weight value is 1. A method for estimating the exit temperature of a finishing mill, which includes the following steps: subtracting a theoretical exit temperature from an actual exit temperature to obtain a learned compensation value; a first position between the entrance of a finishing mill and the exit of a finishing mill , Obtain an actual temperature at a first location and a theoretical temperature at a first location; The first position actual temperature is subtracted from the first position theoretical temperature to obtain a first position compensation value; the first position compensation value is multiplied by a first position weight value and the learned compensation value is multiplied by a learning The weight values are added to obtain a corrected compensation value, wherein the sum of the first position weight value and the learning weight value is 1; and the theoretical outlet temperature and a corrected compensation value are added to obtain a finishing mill Estimated outlet temperature.

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