A blast furnace design system and method

Abstract

The present application relates to a kind of blast furnace furnace type design system and method, belong to blast furnace design technical field.It includes: according to the preset furnace type size, raw material condition, blast parameter, operation parameter calculation furnace temperature, soft melting zone position, iron oxide indirect reduction completed position, and according to the law of furnace temperature, soft melting zone position, iron oxide indirect reduction completed position when the change of furnace type size determines suitable furnace type size.The system includes preset working condition module, material balance and heat balance module, furnace temperature (including soft melting zone position) calculation module, iron oxide indirect reduction completed position calculation module, furnace type size rationality judging module.The present application provides a kind of furnace type design method, quantifies the synergistic effect of furnace type size and raw material condition, blast parameter, operation parameter on furnace state, provides a kind of new method for designing furnace type.

Description

Technical Field

[0001] This invention belongs to the field of blast furnace design technology, and relates to a blast furnace design system and method. Background Technology

[0002] The blast furnace shape is closely related to the descent of the burden and the ascent of the gas flow. The furnace shape affects the descent rate of the burden, the ascent rate of the gas flow, and the heat exchange capacity between the gas and the burden, which in turn affects the furnace temperature distribution and the reduction process of iron ore. Therefore, furnace shape design is a very important part of blast furnace design.

[0003] Past blast furnace designs were mainly based on previous furnace dimensions, combined with the operating conditions of the blast furnace, and modified according to experience or qualitative rules. Some of these designs were successful in practice, while others encountered problems. The main reason for the uncertainty in the effectiveness of these furnace designs was the lack of quantification of the relationship between furnace dimensions, raw material conditions, operating parameters, and the internal state of the furnace, resulting in insufficient adaptability of the blast furnace design to the operating conditions. Summary of the Invention

[0004] In view of this, the purpose of the present invention is to provide a blast furnace design system and method, which determines the appropriate furnace design size based on the quantitative relationship between furnace size, furnace temperature distribution, and the reduction process of iron ore. This addresses the problem that existing blast furnace designs rely heavily on existing furnace types and engineering experience, making it difficult to quantitatively reveal the synergistic effects of furnace size, raw material conditions, blast parameters, and operating parameters on furnace temperature distribution, softening zone location, and iron oxide reduction process, resulting in insufficient adaptability of the design results to operating conditions.

[0005] To achieve the above objectives, the present invention provides a blast furnace design method, comprising: At least one set of operating conditions and furnace size parameters to be tested are preset; the operating conditions include raw material conditions, blast parameters and operating parameters; wherein, the furnace size parameters to be tested are obtained from a historical database containing furnace size parameters, and based on the blast furnace volume to be designed, the historical blast furnace size parameters under the same volume are searched from the database.

[0006] Material balance and heat balance calculations are performed based on raw material conditions, blast parameters, and operating parameters to obtain material parameters and gas parameters used for furnace temperature calculation. Based on the material parameters, gas parameters, and furnace size parameters to be calculated, the furnace temperature distribution and the location of the softening zone inside the blast furnace are calculated; where the softening zone is the furnace charge within a temperature range, and the location of the softening zone can be obtained at the same time as calculating the furnace temperature distribution.

[0007] Based on the furnace temperature distribution and the properties of the furnace charge, the location where the indirect reduction of iron oxides in the furnace is completed is calculated; Based on the relative positional relationship between the location where the indirect reduction of iron oxides is completed and the location of the softening zone, determine whether the furnace temperature distribution is reasonable. If it is reasonable, record the furnace size parameters to be calculated. By changing the furnace size parameters to be tested and repeatedly calculating the furnace temperature distribution, the location of the softening zone, and the location where the indirect reduction of iron oxides is completed, the range of furnace size that makes the furnace temperature distribution reasonable under the current operating conditions can be obtained.

[0008] By changing the operating conditions, the range of furnace size under different operating conditions is obtained, and the distribution range of the target furnace size is determined based on the range of furnace size under different operating conditions.

[0009] Furthermore, the raw material conditions include the composition, particle size, and heat transfer parameters of the ore, coke, and pulverized coal used in the blast furnace; the blast parameters include moisture content, oxygen enrichment, and blast temperature; and the operating parameters include blast furnace output and pulverized coal injection rate. Pulverized coal and some coke are used as fuel.

[0010] Furthermore, the material balance calculation and heat balance calculation include: calculating material parameters and gas parameters based on the principles of material balance and heat balance, according to the raw material conditions and blast parameters; among which, the material parameters include the amount of ore used and the amount of fuel consumed, and the gas parameters include the amount of gas in the tuyere swirl zone and the gas temperature in the tuyere swirl zone.

[0011] Furthermore, the calculation of furnace temperature distribution includes: based on the amount of ore used, fuel consumption, ore particle size, coke particle size, gas volume and temperature in the tuyere swirl zone, combined with the heat exchange between the gas and the furnace charge, the heat consumption of the reaction in the furnace, and the furnace size parameters to be calculated, the furnace temperature distribution is calculated, and the location of the softening zone is determined simultaneously.

[0012] Furthermore, by combining the furnace temperature distribution and the properties of the furnace charge, the location where the indirect reduction of iron oxides in the furnace is completed is calculated. This includes: calculating the kinetic parameters of the iron ore reduction chemistry in each region of the furnace based on the furnace temperature distribution and the properties of the furnace charge, and further calculating the reduction rate based on the kinetic parameters, and then calculating the location of the indirect reduction of iron ore in the furnace based on the reduction rate.

[0013] Furthermore, based on the relative positional relationship between the location where the indirect reduction of iron oxides is completed and the location of the softening zone, and based on the principle that the location of the indirect reduction of iron ore must be higher than the location of the softening zone, it is determined whether the furnace temperature distribution is reasonable.

[0014] Specifically, if the location of indirect reduction of iron ore is higher than the softening zone, the furnace temperature distribution is reasonable, and the furnace size parameters to be calculated are recorded. If the location of indirect reduction of iron ore is not higher than the location of the softening zone, the furnace temperature distribution is unreasonable. Discard the current furnace size parameters to be calculated, and calculate the furnace temperature distribution, location of indirect reduction of iron ore, and location of the softening zone corresponding to the next furnace size parameters to be calculated.

[0015] Furthermore, determining the target furnace size based on the furnace size range under different operating conditions includes taking the intersection of the furnace size range under different operating conditions as the target furnace size distribution range.

[0016] On the other hand, the present invention provides a blast furnace design system, which includes a preset operating condition module, a material balance and heat balance module, a furnace temperature and softening zone position calculation module, an iron oxide indirect reduction completion position calculation module, and a furnace size rationality judgment module. The system is configured to perform the methods described in the foregoing aspects.

[0017] The beneficial effects of this invention are as follows: (1) The present invention incorporates raw material conditions, blast parameters, operating parameters and furnace size into the calculation, which can reflect the comprehensive effect of each factor on the thermal state and reduction process in the furnace and improve the systematicness of the design.

[0018] (2) This invention transforms empirical judgment into a quantifiable and comparable analysis process by continuously calculating material balance, heat balance, furnace temperature distribution and indirect reduction position, thereby improving the objectivity of furnace design and the repeatability of the process.

[0019] (3) By comparing the relative positional relationship between the indirect reduction of iron oxide and the softening zone, and by repeatedly calculating different furnace sizes, this invention can identify unreasonable furnace types, narrow the design range, and reduce the risk of mismatch between furnace type and working conditions.

[0020] (4) By determining the reasonable range of furnace size under different working conditions and finding the intersection, the present invention can obtain a furnace structure that adapts to changes in raw materials and operation, thereby improving the design reliability and operational stability of the blast furnace.

[0021] Other advantages, objectives, and features of the invention will be set forth in part in the description which follows, and in part will be apparent to those skilled in the art from the following examination, or may be learned from practice of the invention. The objectives and other advantages of the invention can be realized and obtained through the following description. Attached Figure Description

[0022] To make the objectives, technical solutions, and advantages of the present invention clearer, the preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings, wherein: Figure 1 This is a schematic diagram of the blast furnace design method provided by the present invention; Figure 2 This is a schematic diagram of the furnace dimensions; Figure 3 This is a schematic diagram of the furnace temperature distribution; Figure 4 In order to be in Figure 3 The diagram shows the location of indirect iron ore reduction under the furnace temperature distribution shown. Figure 5 This is a schematic diagram showing the location of indirect iron ore reduction when the furnace body height is 18000 mm. Figure 6 This is a schematic diagram showing the location of indirect iron ore reduction when the furnace body height is 18600 mm. Figure 7 This is a schematic diagram of the furnace temperature distribution when the furnace waist radius is 7.5 m and the maximum daily iron production is 10,000 t. Figure 8 for Figure 7 The diagram shows the location of indirect reduction of iron ore under the furnace temperature distribution shown. Figure 9 This diagram shows the furnace temperature distribution, the location of indirect iron ore reduction, and the location of the softening zone when the furnace waist radius is 7.9 m. Figure 10 This diagram shows the furnace temperature distribution, the location of indirect iron ore reduction, and the location of the softening zone when the furnace waist radius is 8.4 m. Detailed Implementation

[0023] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of the present invention. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0024] The accompanying drawings are for illustrative purposes only and are schematic diagrams, not actual pictures. They should not be construed as limiting the invention. To better illustrate the embodiments of the invention, some parts in the drawings may be omitted, enlarged, or reduced, and do not represent the actual product dimensions. It is understandable to those skilled in the art that some well-known structures and their descriptions may be omitted in the drawings.

[0025] In the accompanying drawings of the embodiments of the present invention, the same or similar reference numerals correspond to the same or similar components. In the description of the present invention, it should be understood that if terms such as "upper," "lower," "left," "right," "front," and "rear" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, they are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, the terms used to describe positional relationships in the drawings are only for illustrative purposes and should not be construed as limiting the present invention. For those skilled in the art, the specific meaning of the above terms can be understood according to the specific circumstances.

[0026] like Figure 1 As shown, this invention provides a blast furnace design method, which includes: 1) Parameter preset Preset raw material conditions, including the composition and particle size of the ore, coke, and pulverized coal that the blast furnace may use, as well as heat transfer parameters; Preset the blower parameters to determine the possible airflow and oxygen enrichment rate, as well as the air temperature range, based on the capacity of the blower and oxygen generator. Preset operating parameters, including the range of output and pulverized coal injection rate; Furnace parameters are variables in this method. The appropriate furnace size is determined by adjusting the furnace temperature, the position of the softening zone, and the position where the indirect reduction of iron oxides is completed.

[0027] 2) Material balance and heat balance calculations Based on the preset raw material conditions and blast parameters, the ore consumption, fuel consumption, and gas volume and temperature in the tuyeres' vortex zone are calculated according to the principles of material balance and heat balance, and used as the conditions for furnace temperature calculation.

[0028] 3) Calculate furnace temperature Based on the amount of ore and fuel used, the particle size of ore and coke, the amount and temperature of gas, as well as the heat exchange between gas and furnace charge and the heat consumption of the reaction inside the furnace, the furnace temperature distribution and the location of the softening zone are calculated in conjunction with the furnace size.

[0029] 4) Calculate the location of indirect reduction of iron ore Based on the furnace temperature distribution and the properties of the furnace charge, the kinetic parameters of the iron ore reduction chemistry in each region are calculated, and the reduction rate is calculated. Then, the location of indirect reduction of iron ore in the furnace is calculated.

[0030] 5) Determine the reasonableness of the furnace temperature The rationality of the furnace temperature is judged based on the principle that the indirect reduction of iron ore must be above the softening zone.

[0031] 6) Calculate suitable furnace dimensions Change the furnace size and repeat steps 3) to 5) to determine the reasonable range of furnace size under the current raw material conditions, blast parameters, and operating parameters.

[0032] 7) Determine the optimal furnace size By changing the raw material conditions, blast parameters, and operating parameters, and repeating steps 1) to 6), the intersection of the reasonable furnace size range under different conditions is the optimal furnace size.

[0033] The present invention will be illustrated by some examples below.

[0034] Example 1 This embodiment designs the furnace body height in the dimensions of a blast furnace, and the steps are as follows: 1. Preset operating conditions 1) Raw material conditions, as shown in Table 1.

[0035] Table 1

[0036] 2) Blower parameters, as shown in Table 2.

[0037] Table 2

[0038] 3) Operating parameters, as shown in Table 3.

[0039] Table 3

[0040] 4) Furnace type and dimensions, such as Figure 2 As shown in Table 4.

[0041] Table 4

[0042] 2. Material balance and heat balance calculations The material and gas parameters were calculated based on an oxygen enrichment rate of 6%. The data related to the furnace temperature calculation are shown in Table 5.

[0043] Table 5

[0044] 3. Calculate furnace temperature distribution The furnace temperature was calculated based on a predetermined furnace height of 17,600 mm and a maximum daily iron production of 10,000 t. The furnace temperature distribution is as follows: Figure 3 As shown, the discontinuity of furnace temperature can be used to preliminarily determine that the furnace temperature distribution is abnormal.

[0045] 4. Calculate the location where the indirect reduction of iron oxides is completed. To further determine whether the furnace temperature was appropriate, the locations of indirect iron ore reduction under this furnace temperature distribution were calculated, such as... Figure 4 As shown in the calculation results, the indirect reduction of Fe3O4 and FeO occurs in the middle of the softening zone.

[0046] 5. Determine the reasonableness of the furnace temperature. Based on the principle that the indirect reduction of iron ore must be located above the softening zone, this furnace temperature distribution is unreasonable, indicating that the furnace height must be greater than 17600mm.

[0047] 6. Change the furnace height to be calculated. The furnace height was adjusted to 18000 mm, and the furnace temperature distribution, the location of indirect iron ore reduction, and the location of the softening zone were recalculated. The results are as follows: Figure 5 As shown, the principle that the indirect reduction of iron ore must be located above the softening zone indicates that a furnace height of 18,000 mm or more is appropriate.

[0048] The furnace height was adjusted to 18600 mm, and the furnace temperature distribution, the location of indirect iron ore reduction, and the location of the softening zone were recalculated. The results are as follows: Figure 6 As shown.

[0049] from Figure 5 and Figure 6 It can be seen that when the furnace height is 18000 mm and 18600 mm, it meets the principle that the position of indirect iron ore reduction must be higher than the softening zone. Therefore, the two furnace height parameters of 18000 mm and 18600 mm are recorded.

[0050] Therefore, the target dimensions for furnace height are above 18,000 mm.

[0051] 7. Determine the target furnace height In comparison, the improvement of a furnace height of 18,600 mm over 18,000 mm is not very significant, and the cost is higher when the furnace height is 18,600 mm. Therefore, the optimal furnace height is 18,000 mm.

[0052] The height of the furnace waist and the height of the furnace belly can also be determined according to the method provided in this embodiment.

[0053] Example 2 This embodiment designs the waist diameter of a blast furnace in the dimensions of a certain blast furnace type. The steps are as follows: 1. Preset operating conditions 1) Raw material conditions, as shown in Table 1 of Example 1.

[0054] 2) Blower parameters, as shown in Table 2 of Example 1.

[0055] 3) Operating parameters, as shown in Table 3 of Example 1.

[0056] 4) Furnace dimensions: After determining the reasonable furnace height in Example 1, the dimensions are shown in Table 6.

[0057] Table 6

[0058] 2. Material balance and heat balance calculations were performed, and the results were consistent with those in Table 5 of Example 1. 3. Calculate furnace temperature distribution The furnace temperature is calculated based on a furnace waist radius of 7.5 m and a maximum daily iron production of 10,000 t. The furnace temperature distribution is as follows: Figure 7 As shown, the discontinuity of furnace temperature can be used to preliminarily determine that the furnace temperature distribution is abnormal.

[0059] 4. Calculate the location where the indirect reduction of iron oxides is completed. To further determine whether the furnace temperature was appropriate, the locations of indirect iron ore reduction under this furnace temperature distribution were calculated, such as... Figure 8 As shown in the calculation results, the indirect reduction of Fe3O4 and FeO occurs in the middle of the softening zone.

[0060] 5. Determine the reasonableness of the furnace temperature. According to the principle that the indirect reduction of iron ore must be located above the softening zone, this furnace temperature distribution is unreasonable. Moreover, the furnace waist radius is constrained by the furnace belly angle, which is 84.2894° at this time. This is too large and not conducive to the formation of slag skin, indicating that the furnace waist radius must be greater than 7.5 m.

[0061] 6. Change the furnace waist radius to be calculated. The furnace waist radius was adjusted to 7.9 m, and the furnace temperature distribution, the location of indirect iron ore reduction, and the location of the softening zone were recalculated. The results are as follows: Figure 9 As shown, the principle that the location of indirect iron ore reduction must be higher than the softening zone indicates that a furnace waist radius of 7.9 m or more is appropriate.

[0062] The furnace waist radius was adjusted to 8.4 m, and the furnace temperature distribution, the location of indirect iron ore reduction, and the location of the softening zone were recalculated. The results are as follows: Figure 10 As shown.

[0063] from Figure 9 and Figure 10 It can be seen that when the furnace waist radius is 7.9 m and 8.4 m, it meets the principle that the position of indirect reduction of iron ore must be higher than the position of the softening zone.

[0064] Therefore, the target size range for the furnace waist radius is 7.9 m or more.

[0065] 7. Determine the target furnace waist diameter In comparison, the improvement of a furnace waist radius of 8.4 m over 7.9 m is not very significant. Considering investment economics, the optimal furnace waist diameter is 7.9 m. 2 = 15.8 m is more suitable.

[0066] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A blast furnace design method, characterized in that, The method includes: Obtain at least one set of operating conditions and furnace size parameters to be calculated; operating conditions include raw material conditions, blast parameters, and operating parameters; Material balance and heat balance calculations are performed based on raw material conditions, blast parameters, and operating parameters to obtain material parameters and gas parameters used for furnace temperature calculation. Based on the material parameters, gas parameters, and furnace size parameters to be calculated, calculate the furnace temperature distribution and the location of the softening zone inside the blast furnace; Based on the furnace temperature distribution and the properties of the furnace charge, the location where the indirect reduction of iron oxides in the furnace is completed is calculated; Based on the relative positional relationship between the location where the indirect reduction of iron oxides is completed and the location of the softening zone, determine whether the furnace temperature distribution is reasonable. If it is reasonable, record the furnace size parameters to be calculated. By changing the furnace size parameters to be tested and repeatedly calculating the furnace temperature distribution, the location of the softening zone, and the location where the indirect reduction of iron oxides is completed, the range of furnace size that makes the furnace temperature distribution reasonable under the current operating conditions can be obtained. By changing the operating conditions, the range of furnace size under different operating conditions is obtained, and the target furnace size is determined based on the reasonable range of furnace size under different operating conditions.

2. The method according to claim 1, characterized in that, Raw material conditions include the composition, particle size, and heat transfer parameters of the ore, coke, and pulverized coal used in the blast furnace; The blower parameters include moisture content, oxygen enrichment rate, and air temperature. Operating parameters include blast furnace output and pulverized coal injection rate.

3. The method according to claim 2, characterized in that, Material balance and heat balance calculations include: calculating material parameters and gas parameters based on raw material conditions and blast parameters; among which, material parameters include ore consumption and fuel consumption, and gas parameters include gas volume and temperature in the tuyere swirl zone.

4. The method according to claim 3, characterized in that, The calculation of furnace temperature distribution includes: based on the amount of ore used, fuel consumption, ore particle size, coke particle size, gas volume and temperature in the tuyere swirl zone, combined with the heat exchange between gas and furnace charge, the heat consumption of the reaction in the furnace, and the furnace size parameters to be calculated, the furnace temperature distribution is calculated, and the location of the softening zone is determined simultaneously.

5. The method according to claim 4, characterized in that, The calculation of the location where the indirect reduction of iron oxides in the furnace is completed, based on the furnace temperature distribution and the properties of the furnace charge, includes: calculating the kinetic parameters of the iron ore reduction chemistry in each region of the furnace based on the furnace temperature distribution and the properties of the furnace charge; calculating the reduction rate based on the kinetic parameters; and calculating the location of the indirect reduction of iron ore in the furnace based on the reduction rate.

6. The method according to claim 5, characterized in that, Based on the relative positional relationship between the location where the indirect reduction of iron oxides is completed and the location of the softening zone, and based on the principle that the location of the indirect reduction of iron ore is higher than the location of the softening zone, it is determined whether the furnace temperature distribution is reasonable.

7. The method according to claim 1, characterized in that, Determining the target furnace size based on the range of furnace size under different operating conditions includes taking the intersection of the furnace size ranges under different operating conditions as the target furnace size.

8. The method according to claim 1, characterized in that, Based on the target blast furnace volume, the historical blast furnace size parameters of the same volume are retrieved from the historical database and used as the furnace size parameters to be calculated.

9. A blast furnace design system for implementing the method according to any one of claims 1 to 8, characterized in that, The system includes a preset operating condition module, a material balance and heat balance module, a furnace temperature and softening zone position calculation module, an iron oxide indirect reduction completion position calculation module, and a furnace size rationality judgment module.

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