Crystallizer cooling water flow determination method and device based on thermal equivalence

Abstract

The invention provides a crystallizer cooling water flow determination method and device based on thermal equivalence. The method comprises the steps that the cooling water flow speed of the first crystallizer cooling structure is determined; according to the physical property parameters of the cooling water, the cooling water flow speed of the first crystallizer cooling structure and the equivalent diameter of a cooling water pipeline, the convective heat transfer coefficient between the first crystallizer cooling structure and the cooling water is determined; the equivalent diameter of a cooling water pipeline of the second crystallizer cooling structure is obtained, and the cooling water flow speed of the second crystallizer cooling structure is determined according to the physical property parameters of the cooling water, the convective heat transfer coefficient and the equivalent diameter of the cooling water pipeline of the second crystallizer cooling structure; therefore, the cooling water flow of the second crystallizer cooling structure is determined. Thermal equivalence of the crystallizer can be achieved physically, uniform growth of a blank shell is guaranteed, the bleed-out risk is reduced, and the casting blank quality is improved.

Description

Technical Field

[0001] This application relates to the field of metal processing technology, and in particular to a method and apparatus for determining the cooling water flow rate of a crystallizer based on thermal equivalence. Background Technology

[0002] Thermoequivalence of the crystallizer is a core concept in continuous casting process control and optimization. It refers to maintaining a stable and similar heat flux density distribution and thermal state within the crystallizer or between different crystallizers under different operating conditions by adjusting process parameters. Taking a slab continuous casting machine as an example, by making the wide-face cooling structure and the narrow-face cooling structure of the crystallizer thermally equivalent, the wide and narrow-face cooling structures of the crystallizer have similar thermal behavior and solidification states, thereby ensuring uniform shell growth, reducing the risk of leaks, and improving the quality of the cast billet.

[0003] In related technologies, the ratio of cooling water volume in the wide and narrow face cooling structures of the crystallizer is typically set as the ratio of the width of the copper plate in the wide and narrow face of the crystallizer to achieve thermal equivalence. This method is also commonly used between different casting machines. For example, between a 2150mm casting machine and a 1650mm casting machine, the ratio of the water volume in the wide face of the 2150mm casting machine's crystallizer to the water volume in the wide face of the 1650mm casting machine's crystallizer is set to 2150 / 1650.

[0004] However, the method of determining the cooling water flow rate based on the width of the crystallizer copper plate to achieve crystallizer thermal equivalence relies on the premise that the temperature difference between the inlet and outlet cooling water of the crystallizer can remain constant. In reality, however, the temperature difference between the inlet and outlet cooling water is a result of convective heat transfer between the crystallizer copper plate and the cooling water, and therefore usually varies. This makes it difficult to truly achieve crystallizer thermal equivalence based solely on the width of the crystallizer copper plate, leading to uneven billet shell growth, increased risk of steel leakage, and negative impact on billet quality. Summary of the Invention

[0005] This application provides a method and apparatus for determining the cooling water flow rate of a crystallizer based on thermal equivalence, which can accurately realize the thermal equivalence of the crystallizer, thereby ensuring uniform growth of the billet shell, reducing the risk of steel leakage, and improving the quality of the cast billet.

[0006] In a first aspect, this application provides a method for determining the cooling water flow rate of a crystallizer based on thermal equivalence, the method comprising: Determine the cooling water flow rate of the cooling structure of the first crystallizer; The convective heat transfer coefficient between the cooling structure of the first crystallizer and the cooling water is determined based on the physical properties of the cooling water, the flow rate of the cooling water in the cooling structure of the first crystallizer, and the equivalent diameter of the cooling water pipe. Obtain the equivalent diameter of the cooling water pipe of the second crystallizer cooling structure, and determine the cooling water flow rate of the second crystallizer cooling structure based on the physical properties of the cooling water, the convective heat transfer coefficient, and the equivalent diameter of the cooling water pipe of the second crystallizer cooling structure. Based on the cooling water flow rate of the second crystallizer cooling structure, the cooling water flow rate of the second crystallizer cooling structure is determined so as to achieve thermal equivalence between the second crystallizer cooling structure and the first crystallizer cooling structure through the cooling water flow rate of the second crystallizer cooling structure.

[0007] In some possible implementations, determining the cooling water flow rate of the first crystallizer cooling structure includes: Obtain the cooling water flow rate and cooling water pipe cross-sectional area of ​​the first crystallizer cooling structure, and determine the cooling water velocity of the first crystallizer cooling structure based on the cooling water flow rate and cooling water pipe cross-sectional area.

[0008] In some possible implementations, the physical properties of the cooling water include kinematic viscosity, Prandtl number, and thermal conductivity; The convective heat transfer coefficient between the cooling structure and the cooling water is determined based on the physical properties of the cooling water, the cooling water flow velocity of the first crystallizer cooling structure, and the equivalent diameter of the cooling water pipe. This includes: determining the Reynolds number of the first crystallizer cooling structure based on the kinematic viscosity of the cooling water, the cooling water flow velocity of the first crystallizer cooling structure, and the equivalent diameter of the cooling water pipe; determining the Nusselt number of the first crystallizer cooling structure based on the Reynolds number of the first crystallizer cooling structure and the Prandtl number of the cooling water; and determining the convective heat transfer coefficient between the first crystallizer cooling structure and the cooling water based on the Nusselt number of the first crystallizer cooling structure, the thermal conductivity of the cooling water, and the equivalent diameter of the cooling water pipe of the first crystallizer cooling structure.

[0009] In some possible implementations, the physical properties of the cooling water include kinematic viscosity, Prandtl number, and thermal conductivity; Obtain the equivalent diameter of the cooling water pipes in the cooling structure of the second crystallizer, and determine the cooling water flow velocity of the second crystallizer cooling structure based on the physical properties of the cooling water, the convective heat transfer coefficient, and the equivalent diameter of the cooling water pipes. This includes: determining the Nusselt number of the second crystallizer cooling structure based on the convective heat transfer coefficient, the equivalent diameter of the cooling water pipes, and the thermal conductivity of the cooling water; determining the Reynolds number of the second crystallizer cooling structure based on the Nusselt number and the Prandtl number of the cooling water; and determining the cooling water flow velocity of the second crystallizer cooling structure based on the Reynolds number, the kinematic viscosity of the cooling water, and the equivalent diameter of the cooling water pipes.

[0010] In some possible implementations, the cooling water flow rate of the second crystallizer cooling structure is determined based on the cooling water flow velocity of the second crystallizer cooling structure, including: Obtain the cross-sectional area of ​​the cooling water pipe of the second crystallizer cooling structure, and determine the cooling water flow rate of the second crystallizer cooling structure based on the cooling water flow velocity and the cross-sectional area of ​​the cooling water pipe.

[0011] In some possible implementations, the physical properties of the cooling water include kinematic viscosity, Prandtl number, and thermal conductivity; before determining the convective heat transfer coefficient between the first crystallizer cooling structure and the cooling water based on the physical properties of the cooling water, the cooling water flow rate of the first crystallizer cooling structure, and the equivalent diameter of the cooling water pipes, the following steps are also included: Obtain the average temperature of the cooling water, and obtain the kinematic viscosity, Prandtl number, and thermal conductivity of the cooling water at the average temperature.

[0012] Secondly, this application provides a device for determining the cooling water flow rate of a crystallizer based on thermal equivalence, the device comprising: The first cooling water flow rate determination module is used to determine the cooling water flow rate of the first crystallizer cooling structure. The convective heat transfer coefficient determination module is used to determine the convective heat transfer coefficient between the cooling structure of the first crystallizer and the cooling water based on the physical properties of the cooling water, the cooling water flow rate of the cooling structure of the first crystallizer, and the equivalent diameter of the cooling water pipe. The second cooling water flow rate determination module is used to obtain the equivalent diameter of the cooling water pipe of the second crystallizer cooling structure, and determine the cooling water flow rate of the second crystallizer cooling structure based on the physical properties of the cooling water, the convective heat transfer coefficient and the equivalent diameter of the cooling water pipe of the second crystallizer cooling structure. The cooling water flow rate determination module is used to determine the cooling water flow rate of the second crystallizer cooling structure based on the cooling water flow velocity of the second crystallizer cooling structure, so as to achieve thermal equivalence between the second crystallizer cooling structure and the first crystallizer cooling structure through the cooling water flow rate of the second crystallizer cooling structure.

[0013] Thirdly, this application provides an electronic device, which includes: a processor and a memory storing computer program instructions; the processor reads and executes the computer program instructions to implement the method for determining the flow rate of crystallizer cooling water based on thermal equivalence as described above.

[0014] Fourthly, this application provides a computer-readable storage medium storing computer program instructions, which, when executed by a processor, implement the method for determining the flow rate of crystallizer cooling water based on thermal equivalence as described above.

[0015] Fifthly, this application provides a computer program product in which the instructions are executed by the processor of an electronic device, causing the electronic device to perform the crystallizer cooling water flow determination method based on thermal equivalence as described above.

[0016] The method and apparatus for determining the cooling water flow rate of a crystallizer based on thermal equivalence provided in this application embodiment determine the cooling water flow velocity of the first crystallizer cooling structure; determine the convective heat transfer coefficient between the first crystallizer cooling structure and the cooling water based on the physical properties of the cooling water, the cooling water flow velocity of the first crystallizer cooling structure, and the equivalent diameter of the cooling water pipe; then obtain the equivalent diameter of the cooling water pipe of the second crystallizer cooling structure, and determine the cooling water flow velocity of the second crystallizer cooling structure based on the physical properties of the cooling water, the convective heat transfer coefficient, and the equivalent diameter of the cooling water pipe of the second crystallizer cooling structure; thus, the cooling water flow rate of the second crystallizer cooling structure is determined based on the cooling water flow velocity of the second crystallizer cooling structure, which has the following technical effects: This application no longer uses the width or area of ​​the crystallizer copper plate as the basis for judging thermal equivalence, but directly uses the convective heat transfer coefficient as the criterion, fundamentally avoiding the problem of thermal equivalence failure caused by changes in the temperature difference between the inlet and outlet cooling water. By determining the convective heat transfer coefficient based on the physical properties of the cooling water, the cooling water flow rate of the first crystallizer cooling structure, and the equivalent diameter of the cooling water pipe, the true heat exchange state between the cooling water and the crystallizer copper plate can be objectively reflected. Furthermore, by ensuring that the second crystallizer cooling structure has the same convective heat transfer coefficient as the first crystallizer cooling structure, the cooling water flow rate of the second crystallizer cooling structure can be determined, ensuring that the heat transfer conditions between different crystallizer cooling structures remain consistent, thereby achieving crystallizer thermal equivalence in a physical sense. This, in turn, ensures uniform billet shell growth, reduces the risk of steel leakage, and improves billet quality. Attached Figure Description

[0017] This application can be better understood from the following description of specific embodiments in conjunction with the accompanying drawings, wherein: Other features, objects, and advantages of this application will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings, wherein the same or similar reference numerals denote the same or similar features.

[0018] Figure 1 This is a flowchart of a method for determining the cooling water flow rate of a crystallizer based on thermal equivalence, provided in some embodiments of this application; Figure 2 This is a schematic diagram of the structure of a crystallizer cooling water flow rate determination device based on thermal equivalence provided in some embodiments of this application; Figure 3 This is a schematic diagram of the hardware structure of the electronic device provided in the embodiments of this application. Detailed Implementation

[0019] The features and exemplary embodiments of various aspects of this application will be described in detail below. To make the objectives, technical solutions, and advantages of this application clearer, the application will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only intended to explain this application and not to limit it. For those skilled in the art, this application can be implemented without some of these specific details. The following description of the embodiments is merely to provide a better understanding of this application by illustrating examples.

[0020] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising..." does not exclude the presence of additional identical elements in the process, method, article, or apparatus that includes the element.

[0021] Thermoequivalence of the crystallizer is a core concept in continuous casting process control and optimization. It refers to maintaining a stable and similar heat flux density distribution and thermal state within the crystallizer or between different crystallizers under different operating conditions by adjusting process parameters. Taking a slab continuous casting machine as an example, by making the wide-face cooling structure and the narrow-face cooling structure of the crystallizer thermally equivalent, the wide and narrow-face cooling structures of the crystallizer have similar thermal behavior and solidification states, thereby ensuring uniform shell growth, reducing the risk of leaks, and improving the quality of the cast billet.

[0022] In related technologies, the ratio of cooling water volume in the wide and narrow face cooling structures of the crystallizer is typically set as the ratio of the width of the copper plate in the wide and narrow face of the crystallizer to achieve thermal equivalence. This method is also commonly used between different casting machines. For example, between a 2150mm casting machine and a 1650mm casting machine, the ratio of the water volume in the wide face of the 2150mm casting machine's crystallizer to the water volume in the wide face of the 1650mm casting machine's crystallizer is set to 2150 / 1650.

[0023] However, the method of determining the cooling water flow rate based on the width of the crystallizer copper plate to achieve crystallizer thermal equivalence relies on the premise that the temperature difference between the inlet and outlet cooling water of the crystallizer can remain constant. In reality, however, the temperature difference between the inlet and outlet cooling water is a result of convective heat transfer between the crystallizer copper plate and the cooling water, and therefore usually varies. This makes it difficult to truly achieve crystallizer thermal equivalence based solely on the width of the crystallizer copper plate, leading to uneven billet shell growth, increased risk of steel leakage, and negative impact on billet quality.

[0024] To address the aforementioned problems, embodiments of this application provide a method and apparatus for determining the cooling water flow rate of a crystallizer based on thermal equivalence. The method for determining the cooling water flow rate of a crystallizer based on thermal equivalence, as provided in this application, will be described below.

[0025] Figure 1 A schematic flowchart of a method for determining the cooling water flow rate of a crystallizer based on thermal equivalence, according to an embodiment of this application, is shown. Figure 1 As shown, the method includes the following steps: S101 to S104.

[0026] S101: Determine the cooling water flow rate of the first crystallizer cooling structure.

[0027] S102: Determine the convective heat transfer coefficient between the cooling structure of the first crystallizer and the cooling water based on the physical properties of the cooling water, the cooling water flow rate of the cooling structure of the first crystallizer, and the equivalent diameter of the cooling water pipe.

[0028] S103: Obtain the equivalent diameter of the cooling water pipe of the second crystallizer cooling structure, and determine the cooling water flow rate of the second crystallizer cooling structure based on the physical properties of the cooling water, the convective heat transfer coefficient, and the equivalent diameter of the cooling water pipe of the second crystallizer cooling structure.

[0029] S104: Determine the cooling water flow rate of the second crystallizer cooling structure based on the cooling water flow rate of the second crystallizer cooling structure, so as to achieve thermal equivalence between the second crystallizer cooling structure and the first crystallizer cooling structure through the cooling water flow rate of the second crystallizer cooling structure.

[0030] It should be noted that, in the embodiments of this application, the cooling structure of the crystallizer can correspond to the overall cooling system of the crystallizer, or it can correspond to a local cooling area or independent cooling circuit of the crystallizer, such as a wide-face cooling structure, a narrow-face cooling structure of the crystallizer, or a cooling structure corresponding to different copper plates in the same crystallizer.

[0031] Therefore, this application no longer uses the width or area of ​​the crystallizer copper plate as the basis for judging thermal equivalence, but directly uses the convective heat transfer coefficient as the criterion, fundamentally avoiding the problem of thermal equivalence failure caused by changes in the temperature difference between the inlet and outlet cooling water. By determining the convective heat transfer coefficient based on the physical properties of the cooling water, the cooling water flow rate of the first crystallizer cooling structure, and the equivalent diameter of the cooling water pipe, the true heat transfer state between the cooling water and the crystallizer copper plate can be objectively reflected. On this basis, by determining the cooling water flow rate of the second crystallizer cooling structure by ensuring that the convective heat transfer coefficient of the second crystallizer cooling structure is the same as that of the first crystallizer cooling structure, it is possible to ensure that the heat flow transfer conditions between different crystallizer cooling structures are consistent, thereby achieving crystallizer thermal equivalence in a physical sense, thus ensuring uniform billet shell growth, reducing the risk of steel leakage, and improving billet quality.

[0032] In some embodiments, determining the cooling water flow rate of the first crystallizer cooling structure includes: Obtain the cooling water flow rate and cooling water pipe cross-sectional area of ​​the first crystallizer cooling structure, and determine the cooling water velocity of the first crystallizer cooling structure based on the cooling water flow rate and cooling water pipe cross-sectional area.

[0033] In a practical implementation, the cooling water flow rate and the cross-sectional area of ​​the cooling water pipe of the first crystallizer cooling structure can be obtained. These cooling water flow rate and the cross-sectional area of ​​the cooling water pipe can be relevant parameter values ​​collected or obtained on the production site.

[0034] In one example, the cooling water flow rate of the first crystallizer cooling structure is known to be 3600 Nl / min, and the cross-sectional area of ​​the cooling water pipe is 91.2 cm². 2 The cooling water flow rate of the first crystallizer cooling structure can be calculated as follows: .

[0035] In this embodiment, the cooling water flow rate is calculated by the cooling water flow rate and the cross-sectional area of ​​the cooling water pipe, which enables the method of this application to directly use the existing process parameters on site as input conditions, reducing the complexity of the method implementation and improving the operability and applicability of the method in actual production.

[0036] In some embodiments, the physical properties of the cooling water include kinematic viscosity, Prandtl number, and thermal conductivity; The convective heat transfer coefficient between the cooling structure and the cooling water is determined based on the physical properties of the cooling water, the cooling water flow velocity of the first crystallizer cooling structure, and the equivalent diameter of the cooling water pipe. This includes: determining the Reynolds number of the first crystallizer cooling structure based on the kinematic viscosity of the cooling water, the cooling water flow velocity of the first crystallizer cooling structure, and the equivalent diameter of the cooling water pipe; determining the Nusselt number of the first crystallizer cooling structure based on the Reynolds number of the first crystallizer cooling structure and the Prandtl number of the cooling water; and determining the convective heat transfer coefficient between the first crystallizer cooling structure and the cooling water based on the Nusselt number of the first crystallizer cooling structure, the thermal conductivity of the cooling water, and the equivalent diameter of the cooling water pipe of the first crystallizer cooling structure.

[0037] In practical implementation, the physical properties of the cooling water may include kinematic viscosity, Prandtl number, and thermal conductivity. Therefore, the Reynolds number of the cooling structure of the first crystallizer can be calculated according to the following formula (1): (1) in, The Reynolds number of the cooling structure of the first crystallizer; The cooling water flow rate of the first crystallizer cooling structure is expressed in m / s. The equivalent diameter of the cooling water pipe in the cooling structure of the first crystallizer is expressed in meters. The kinematic viscosity of cooling water, in units of m. 2 / s.

[0038] Based on this, the Nusselt number of the cooling structure of the first crystallizer can be calculated according to the following formula (2): (2) in, The Nusselt number of the cooling structure of the first crystallizer; The Reynolds number of the cooling structure of the first crystallizer; This is the Prandtl number of the cooling water.

[0039] Furthermore, the convective heat transfer coefficient between the cooling structure of the first crystallizer and the cooling water can be calculated according to the following formula (3): (3) in, The convective heat transfer coefficient between the cooling structure of the first crystallizer and the cooling water is expressed in W / (m2·℃). The equivalent diameter of the cooling water pipe in the cooling structure of the first crystallizer is expressed in meters. The thermal conductivity of the cooling water is expressed in W / (m·℃). is the Nusselt number of the cooling structure of the first crystallizer.

[0040] In this embodiment, by introducing a heat transfer calculation method based on Reynolds number and Nusselt number, the convective heat transfer coefficient between the cooling structure of the first crystallizer and the cooling water can be accurately and quantitatively determined, thereby providing a reliable heat transfer benchmark for subsequent thermal equivalent calculations and avoiding errors caused by empirical settings or simplification assumptions.

[0041] In some embodiments, the physical properties of the cooling water include kinematic viscosity, Prandtl number, and thermal conductivity; Obtain the equivalent diameter of the cooling water pipes in the cooling structure of the second crystallizer, and determine the cooling water flow velocity of the second crystallizer cooling structure based on the physical properties of the cooling water, the convective heat transfer coefficient, and the equivalent diameter of the cooling water pipes. This includes: determining the Nusselt number of the second crystallizer cooling structure based on the convective heat transfer coefficient, the equivalent diameter of the cooling water pipes, and the thermal conductivity of the cooling water; determining the Reynolds number of the second crystallizer cooling structure based on the Nusselt number and the Prandtl number of the cooling water; and determining the cooling water flow velocity of the second crystallizer cooling structure based on the Reynolds number, the kinematic viscosity of the cooling water, and the equivalent diameter of the cooling water pipes.

[0042] In practical applications, the equivalent diameter and flow rate of the cooling water pipe of the first crystallizer cooling structure can be replaced with the equivalent diameter and flow rate of the cooling water pipe of the second crystallizer cooling structure by combining the aforementioned formulas (1), (2) and (3), thereby reversing and calculating the Nusselt number, Reynolds number and flow rate of the second crystallizer cooling structure.

[0043] In this embodiment, by reverse calculation of the cooling water flow rate, the second crystallizer cooling structure can obtain the same heat exchange capacity as the first crystallizer cooling structure under different structural parameters. This achieves true crystallizer thermal equivalence in a physical sense, rather than just achieving surface consistency in cooling water volume or geometric dimensions. This helps ensure that the heat transfer conditions between different crystallizer cooling structures remain consistent, thereby achieving crystallizer thermal equivalence in a physical sense. This, in turn, ensures uniform growth of the billet shell, reduces the risk of steel leakage, and improves the quality of the cast billet.

[0044] In some embodiments, determining the cooling water flow rate of the second crystallizer cooling structure based on the cooling water flow rate of the second crystallizer cooling structure includes: Obtain the cross-sectional area of ​​the cooling water pipe of the second crystallizer cooling structure, and determine the cooling water flow rate of the second crystallizer cooling structure based on the cooling water flow velocity and the cross-sectional area of ​​the cooling water pipe.

[0045] In a practical implementation, the cross-sectional area of ​​the cooling water pipe of the second crystallizer cooling structure can be obtained. This cross-sectional area can be a relevant parameter value collected or obtained at the production site. Based on the cooling water flow rate of the second crystallizer cooling structure and the cross-sectional area of ​​the cooling water pipe, the cooling water flow rate of the second crystallizer cooling structure can be determined.

[0046] In this embodiment, by converting the cooling water flow rate obtained based on thermal equivalence calculation into cooling water flow rate, the calculation results of this application can be directly used for setting and adjusting the flow rate of the crystallizer cooling water system, so as to realize the thermal equivalence between the second crystallizer cooling structure and the first crystallizer cooling structure, thereby improving the practicality of the aforementioned method in industrial settings.

[0047] In some embodiments, the physical properties of the cooling water include kinematic viscosity, Prandtl number, and thermal conductivity; before determining the convective heat transfer coefficient between the first crystallizer cooling structure and the cooling water based on the physical properties of the cooling water, the cooling water flow rate of the first crystallizer cooling structure, and the equivalent diameter of the cooling water pipe, the method further includes: Obtain the average temperature of the cooling water, and obtain the kinematic viscosity, Prandtl number, and thermal conductivity of the cooling water at the average temperature.

[0048] In practical applications, when obtaining the physical properties of cooling water, the average temperature of the cooling water can be obtained, along with its kinematic viscosity, Prandtl number, and thermal conductivity at the average temperature. This allows the calculation of the convective heat transfer coefficient to better reflect actual working conditions, improving the accuracy and reliability of the thermal equivalent calculation results, and further ensuring the precision of the thermal equivalent control of the crystallizer.

[0049] In fact, based on the principles of heat transfer, the formula for calculating the heat flow of the continuous casting crystallizer in steady state can be obtained (4): (4) Where q is the heat flux density of the crystallizer, in W / m³. 2 ;T s T represents the melting point of molten steel during continuous casting, expressed in °C. water The average temperature of the cooling water in the crystallizer during the continuous casting process is expressed in °C. The convective heat transfer coefficient between the copper plate of the crystallizer and the cooling water of the crystallizer is expressed in W / (m2·℃). The thickness of the steel billet shell during continuous casting is expressed in meters (m). The thermal conductivity of the billet shell is expressed in W / (m·℃). The thickness of the copper plate in the crystallizer during continuous casting is expressed in meters (m). The value is the thermal conductivity of the copper plate in the crystallizer, expressed in W / (m·℃).

[0050] Based on this, combined with the above formulas (1), (2) and (3), it can be seen that the key parameters affecting the thermal equivalence between different crystallizer cooling structures are the molten steel temperature, the crystallizer cooling water temperature, the billet shell thickness, the billet shell thermal conductivity, the copper plate thickness, the copper plate thermal conductivity, the thermal resistance of the protective slag film, and the convective heat transfer coefficient between the crystallizer copper plate and the cooling water.

[0051] In actual production, the temperature of molten steel and the temperature of the cooling water in the crystallizer are generally stable and controllable, and the thickness of the copper plate in the crystallizer is usually fixed. Furthermore, when achieving thermal equivalence between different crystallizer cooling structures, the heat flow distribution between these structures is similar, and the billet shell thickness can also be approximated as the same. For the same steel grade, under the same casting speed, the consumption of the protective slag can be considered a constant value, meaning the thermal resistance of the protective slag film is equal.

[0052] Therefore, by combining the above formulas (1), (2), (3) and (4), it can be concluded that in the actual production process, by ensuring that the convective heat transfer coefficients between the copper plates and cooling water of different crystallizer cooling structures are equal, thermal equivalence between different crystallizer cooling structures can be achieved.

[0053] In other words, this application directly uses the convective heat transfer coefficient as the thermal equivalence criterion, which can fundamentally avoid the problem of thermal equivalence failure caused by changes in the temperature difference between the inlet and outlet cooling water. By determining the convective heat transfer coefficient based on the physical properties of the cooling water, the cooling water flow rate of the first crystallizer cooling structure, and the equivalent diameter of the cooling water pipe, the true heat exchange state between the cooling water and the copper plate of the crystallizer can be objectively reflected. Furthermore, by determining the cooling water flow rate of the second crystallizer cooling structure by ensuring that the convective heat transfer coefficient of the second crystallizer cooling structure is the same as that of the first crystallizer cooling structure, it is possible to ensure that the heat flow transfer conditions between different crystallizer cooling structures remain consistent, thereby achieving thermal equivalence of the crystallizer in a physical sense. This, in turn, ensures uniform growth of the billet shell, reduces the risk of steel leakage, and improves the quality of the cast billet.

[0054] The embodiments of this application will be further described below with reference to a specific example: In this embodiment, the cooling water flow rate of the first crystallizer cooling structure is known to be 3600 Nl / min, and the cross-sectional area of ​​the cooling water pipe is 91.2 cm². 2 The cooling water flow rate of the first crystallizer cooling structure can be calculated as follows: .

[0055] Furthermore, it is known that the average temperature of the cooling water is 40℃, at which temperature the thermal conductivity of water is 0.633 W / (m·℃) and the kinematic viscosity is 0.659 × 10⁻⁶. -6 m 2 / s, Prandtl number is 4.34, equivalent diameter of cooling water pipe is 8.2 mm; the Reynolds number of the cooling structure of the first crystallizer can be calculated: ; Nusselt number of the cooling structure of the first crystallizer: Nu1=0.023*815820.8*4.340.4=351.6; Thus, the convective heat transfer coefficient between the cooling structure of the first crystallizer and the cooling water is obtained: =351.6*0.633 / 8.2*1000=27228W / (m 2 ·℃).

[0056] Furthermore, given that the equivalent diameter of the cooling water pipes in the second crystallizer cooling structure is 8.6 mm, the Nusselt number of the second crystallizer cooling structure can be calculated: Nu2=27228*8.6 / 1000 / 0.633=369.9; Reynolds number of the cooling structure of the second crystallizer: Re2=(369.9 / 0.023 / 4.340.4)1.25=86936; Thus, the cooling water flow rate of the second crystallizer cooling structure is obtained: .

[0057] Furthermore, it is known that the cross-sectional area of ​​the cooling water pipes in the cooling structure of the second crystallizer is 62.9 cm². 2 The cooling water flow rate of the second crystallizer cooling structure can be calculated: Q=62.9*6.66 / 10*60=2513 Nl / min.

[0058] Therefore, thermal equivalence between the cooling structure of the second crystallizer and the cooling structure of the first crystallizer can be achieved by controlling the cooling water flow rate of the second crystallizer cooling structure.

[0059] Based on the method for determining the cooling water flow rate of a crystallizer based on thermal equivalence provided in the above embodiments, this application also provides a specific implementation of the device for determining the cooling water flow rate of a crystallizer based on thermal equivalence.

[0060] Please refer to the following examples.

[0061] First see Figure 2 The crystallizer cooling water flow rate determination device 200 based on thermal equivalence provided in this application embodiment includes the following modules: The first cooling water flow rate determination module 201 is used to determine the cooling water flow rate of the first crystallizer cooling structure; The convective heat transfer coefficient determination module 202 is used to determine the convective heat transfer coefficient between the cooling structure of the first crystallizer and the cooling water based on the physical property parameters of the cooling water, the cooling water flow rate of the cooling structure of the first crystallizer and the equivalent diameter of the cooling water pipe. The second cooling water flow rate determination module 203 is used to obtain the equivalent diameter of the cooling water pipe of the second crystallizer cooling structure, and determine the cooling water flow rate of the second crystallizer cooling structure based on the physical property parameters of the cooling water, the convective heat transfer coefficient and the equivalent diameter of the cooling water pipe of the second crystallizer cooling structure. The cooling water flow rate determination module 204 is used to determine the cooling water flow rate of the second crystallizer cooling structure based on the cooling water flow velocity of the second crystallizer cooling structure, so as to achieve thermal equivalence between the second crystallizer cooling structure and the first crystallizer cooling structure through the cooling water flow rate of the second crystallizer cooling structure.

[0062] As one implementation of this application, the first cooling water flow rate determination module 201 includes: The first cooling water flow rate determination submodule is used to obtain the cooling water flow rate and cooling water pipe cross-sectional area of ​​the first crystallizer cooling structure, and determine the cooling water flow rate of the first crystallizer cooling structure based on the cooling water flow rate and cooling water pipe cross-sectional area of ​​the first crystallizer cooling structure.

[0063] As one implementation of this application, the physical properties of the cooling water include kinematic viscosity, Prandtl number, and thermal conductivity; the convective heat transfer coefficient determination module 202 includes: The first Reynolds number determination submodule is used to determine the Reynolds number of the first crystallizer cooling structure based on the kinematic viscosity of the cooling water, the cooling water flow rate of the first crystallizer cooling structure, and the equivalent diameter of the cooling water pipe. The first Nusselt number determination submodule is used to determine the Nusselt number of the first crystallizer cooling structure based on the Reynolds number of the first crystallizer cooling structure and the Prandtl number of the cooling water. The convective heat transfer coefficient determination submodule is used to determine the convective heat transfer coefficient between the first crystallizer cooling structure and the cooling water based on the Nusselt number of the first crystallizer cooling structure, the thermal conductivity of the cooling water, and the equivalent diameter of the cooling water pipe of the first crystallizer cooling structure.

[0064] As one implementation of this application, the physical properties of the cooling water include kinematic viscosity, Prandtl number, and thermal conductivity; the second cooling water flow rate determination module 203 includes: The second Nusselt number determination submodule is used to determine the Nusselt number of the second crystallizer cooling structure based on the convective heat transfer coefficient, the equivalent diameter of the cooling water pipe of the second crystallizer cooling structure, and the thermal conductivity of the cooling water. The second Reynolds number determination submodule is used to determine the Reynolds number of the second crystallizer cooling structure based on the Nusselt number of the second crystallizer cooling structure and the Prandtl number of the cooling water. The second cooling water flow rate determination submodule is used to determine the cooling water flow rate of the second crystallizer cooling structure based on the Reynolds number of the second crystallizer cooling structure, the kinematic viscosity of the cooling water, and the equivalent diameter of the cooling water pipe of the second crystallizer cooling structure.

[0065] As one implementation of this application, the cooling water flow rate determination module 204 includes: The cooling water flow rate determination submodule is used to obtain the cross-sectional area of ​​the cooling water pipe of the second crystallizer cooling structure, and determine the cooling water flow rate of the second crystallizer cooling structure based on the cooling water flow rate and the cross-sectional area of ​​the cooling water pipe.

[0066] As one implementation of this application, the physical properties of the cooling water include kinematic viscosity, Prandtl number, and thermal conductivity; the device also includes: The physical property parameter acquisition module is used to obtain the average temperature of the cooling water, and to obtain the kinematic viscosity, Prandtl number, and thermal conductivity of the cooling water at the average temperature.

[0067] Each module in the crystallizer cooling water flow rate determination device based on thermal equivalence provided in this application embodiment can implement each step in the above-mentioned crystallizer cooling water flow rate determination method based on thermal equivalence and achieve the corresponding effect. For the sake of brevity, it will not be described in detail here.

[0068] Figure 3 A schematic diagram of the structure of an electronic device provided in an embodiment of this application is shown.

[0069] The electronic device may include a processor 301 and a memory 302 storing computer program instructions.

[0070] Specifically, the processor 301 may include a central processing unit (CPU), an application-specific integrated circuit (ASIC), or one or more integrated circuits that can be configured to implement the embodiments of this application.

[0071] Memory 302 may include mass storage for data or instructions. For example, and not limitingly, memory 302 may include a hard disk drive (HDD), floppy disk drive, flash memory, optical disk, magneto-optical disk, magnetic tape, or Universal Serial Bus (USB) drive, or a combination of two or more of these. Where appropriate, memory 302 may include removable or non-removable (or fixed) media. Where appropriate, memory 302 may be internal or external to the integrated gateway disaster recovery device. In a particular embodiment, memory 302 is non-volatile solid-state memory.

[0072] Memory may include read-only memory (ROM), random access memory (RAM), disk storage media devices, optical storage media devices, flash memory devices, and electrical, optical, or other physical / tangible memory storage devices. Therefore, typically, memory includes one or more tangible (non-transitory) computer-readable storage media, such as memory devices, encoded with software including computer-executable instructions, and when the software is executed by one or more processors, it is operable to perform the operations described with reference to the thermally equivalent crystallizer cooling water flow rate determination method according to any embodiment of this disclosure.

[0073] The processor 301 reads and executes computer program instructions stored in the memory 302 to implement any of the methods for determining the cooling water flow rate of the crystallizer based on thermal equivalence in the above embodiments.

[0074] In one example, the electronic device may also include a communication interface 303 and a bus 310. For example, Figure 3 As shown, the processor 301, memory 302, and communication interface 303 are connected through bus 310 and complete communication with each other.

[0075] The communication interface 303 is mainly used to realize communication between various modules, devices, units and / or equipment in the embodiments of this application.

[0076] Bus 310 includes hardware, software, or both, that couples components of an online data traffic metering device together. For example, and not limitingly, the bus may include an Accelerated Graphics Port (AGP) or other graphics bus, an Enhanced Industry Standard Architecture (EISA) bus, a Front Side Bus (FSB), HyperTransport (HT) interconnect, an Industry Standard Architecture (ISA) bus, an Infinite Bandwidth Interconnect, a Low Pin Count (LPC) bus, a memory bus, a Microchannel Architecture (MCA) bus, a Peripheral Component Interconnect (PCI) bus, a PCI-Express (PCI-X) bus, a Serial Advanced Technology Attachment (SATA) bus, a Video Electronics Standards Association Local (VLB) bus, or other suitable buses, or combinations of two or more of these. Where appropriate, bus 410 may include one or more buses. Although specific buses are described and illustrated in embodiments of this application, any suitable bus or interconnect is contemplated herein.

[0077] Furthermore, in conjunction with the method for determining the cooling water flow rate of a crystallizer based on thermal equivalence in the above embodiments, this application embodiment can provide a computer storage medium for implementation. This computer storage medium stores computer program instructions; when these computer program instructions are executed by a processor, they implement any of the methods for determining the cooling water flow rate of a crystallizer based on thermal equivalence in the above embodiments.

[0078] This application also provides a computer program product, including a computer program that, when executed, implements any of the methods for determining the flow rate of crystallizer cooling water based on thermal equivalence in the above embodiments.

[0079] It should be clarified that this application is not limited to the specific configurations and processes described above and shown in the figures. For the sake of brevity, detailed descriptions of known methods are omitted here. In the above embodiments, several specific steps are described and shown as examples. However, the method process of this application is not limited to the specific steps described and shown. Those skilled in the art can make various changes, modifications, and additions, or change the order of steps, after understanding the spirit of this application.

[0080] The functional blocks shown in the above block diagram can be implemented as hardware, software, firmware, or a combination thereof. When implemented in hardware, they can be, for example, electronic circuits, application-specific integrated circuits (ASICs), appropriate firmware, plug-ins, function cards, etc. When implemented in software, the elements of this application are programs or code segments used to perform the required tasks. Programs or code segments can be stored on a machine-readable medium or transmitted over a transmission medium or communication link via data signals carried on a carrier wave. "Machine-readable medium" can include any medium capable of storing or transmitting information. Examples of machine-readable media include electronic circuits, semiconductor memory devices, ROM, flash memory, erasable ROM (EROM), floppy disks, CD-ROMs, optical disks, hard disks, fiber optic media, radio frequency (RF) links, etc. Code segments can be downloaded via computer networks such as the Internet, intranets, etc.

[0081] It should also be noted that the exemplary embodiments mentioned in this application describe methods or systems based on a series of steps or apparatus. However, this application is not limited to the order of the above steps; that is, the steps can be performed in the order mentioned in the embodiments, or in a different order, or several steps can be performed simultaneously.

[0082] The aspects of this disclosure have been described above with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this disclosure. It should be understood that each block in the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing apparatus to produce a machine such that these instructions, executable via the processor of the computer or other programmable data processing apparatus, enable the implementation of the functions / actions specified in one or more blocks of the flowchart illustrations and / or block diagrams. Such a processor can be, but is not limited to, a general-purpose processor, a special-purpose processor, a special application processor, or a field-programmable logic circuit. It is also understood that each block in the block diagrams and / or flowcharts, and combinations of blocks in the block diagrams and / or flowcharts, can also be implemented by special-purpose hardware performing the specified functions or actions, or can be implemented by a combination of special-purpose hardware and computer instructions.

[0083] The above are merely specific embodiments of this application. Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working processes of the systems, modules, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here. It should be understood that the protection scope of this application is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in this application, and these modifications or substitutions should all be covered within the protection scope of this application.

Claims

1. A method for determining the cooling water flow rate of a crystallizer based on thermal equivalence, characterized in that, The method includes: Determine the cooling water flow rate of the cooling structure of the first crystallizer; The convective heat transfer coefficient between the first crystallizer cooling structure and the cooling water is determined based on the physical properties of the cooling water, the cooling water flow rate of the first crystallizer cooling structure, and the equivalent diameter of the cooling water pipe. Obtain the equivalent diameter of the cooling water pipe of the second crystallizer cooling structure, and determine the cooling water flow rate of the second crystallizer cooling structure based on the physical property parameters of the cooling water, the convective heat transfer coefficient, and the equivalent diameter of the cooling water pipe of the second crystallizer cooling structure. Based on the cooling water flow rate of the second crystallizer cooling structure, the cooling water flow rate of the second crystallizer cooling structure is determined so as to achieve thermal equivalence between the second crystallizer cooling structure and the first crystallizer cooling structure through the cooling water flow rate of the second crystallizer cooling structure.

2. The method for determining the cooling water flow rate of a crystallizer based on thermal equivalence according to claim 1, characterized in that, Determining the cooling water flow rate of the first crystallizer cooling structure includes: Obtain the cooling water flow rate and cooling water pipe cross-sectional area of ​​the first crystallizer cooling structure, and determine the cooling water velocity of the first crystallizer cooling structure based on the cooling water flow rate and cooling water pipe cross-sectional area of ​​the first crystallizer cooling structure.

3. The method for determining the cooling water flow rate of a crystallizer based on thermal equivalence according to claim 1, characterized in that, The physical properties of the cooling water include kinematic viscosity, Prandtl number, and thermal conductivity. The convective heat transfer coefficient between the first crystallizer cooling structure and the cooling water is determined based on the physical properties of the cooling water, the cooling water flow velocity of the first crystallizer cooling structure, and the equivalent diameter of the cooling water pipe. This includes: determining the Reynolds number of the first crystallizer cooling structure based on the kinematic viscosity of the cooling water, the cooling water flow velocity of the first crystallizer cooling structure, and the equivalent diameter of the cooling water pipe; determining the Nusselt number of the first crystallizer cooling structure based on the Reynolds number of the first crystallizer cooling structure and the Prandtl number of the cooling water; and determining the convective heat transfer coefficient between the first crystallizer cooling structure and the cooling water based on the Nusselt number of the first crystallizer cooling structure, the thermal conductivity of the cooling water, and the equivalent diameter of the cooling water pipe of the first crystallizer cooling structure.

4. The method for determining the cooling water flow rate of a crystallizer based on thermal equivalence according to claim 1, characterized in that, The physical properties of the cooling water include kinematic viscosity, Prandtl number, and thermal conductivity. Obtaining the equivalent diameter of the cooling water pipes in the second crystallizer cooling structure, and determining the cooling water flow velocity of the second crystallizer cooling structure based on the physical properties of the cooling water, the convective heat transfer coefficient, and the equivalent diameter of the cooling water pipes in the second crystallizer cooling structure, includes: determining the Nusselt number of the second crystallizer cooling structure based on the convective heat transfer coefficient, the equivalent diameter of the cooling water pipes in the second crystallizer cooling structure, and the thermal conductivity of the cooling water; determining the Reynolds number of the second crystallizer cooling structure based on the Nusselt number of the second crystallizer cooling structure and the Prandtl number of the cooling water; and determining the cooling water flow velocity of the second crystallizer cooling structure based on the Reynolds number of the second crystallizer cooling structure, the kinematic viscosity of the cooling water, and the equivalent diameter of the cooling water pipes in the second crystallizer cooling structure.

5. The method for determining the cooling water flow rate of a crystallizer based on thermal equivalence according to claim 1, characterized in that, Determining the cooling water flow rate of the second crystallizer cooling structure based on the cooling water flow velocity of the second crystallizer cooling structure includes: Obtain the cross-sectional area of ​​the cooling water pipe of the second crystallizer cooling structure, and determine the cooling water flow rate of the second crystallizer cooling structure based on the cooling water flow velocity and the cross-sectional area of ​​the cooling water pipe.

6. The method for determining the cooling water flow rate of a crystallizer based on thermal equivalence according to claim 1, characterized in that, The physical properties of the cooling water include kinematic viscosity, Prandtl number, and thermal conductivity. Before determining the convective heat transfer coefficient between the first crystallizer cooling structure and the cooling water based on the physical properties of the cooling water, the cooling water flow rate of the first crystallizer cooling structure, and the equivalent diameter of the cooling water pipe, the process further includes: The average temperature of the cooling water is obtained, and the kinematic viscosity, Prandtl number, and thermal conductivity of the cooling water at the average temperature are also obtained.

7. A device for determining the cooling water flow rate of a crystallizer based on thermal equivalence, characterized in that, The device includes: The first cooling water flow rate determination module is used to determine the cooling water flow rate of the first crystallizer cooling structure. The convective heat transfer coefficient determination module is used to determine the convective heat transfer coefficient between the first crystallizer cooling structure and the cooling water based on the physical property parameters of the cooling water, the cooling water flow rate of the first crystallizer cooling structure, and the equivalent diameter of the cooling water pipe. The second cooling water flow rate determination module is used to obtain the equivalent diameter of the cooling water pipe of the second crystallizer cooling structure, and determine the cooling water flow rate of the second crystallizer cooling structure based on the physical property parameters of the cooling water, the convective heat transfer coefficient and the equivalent diameter of the cooling water pipe of the second crystallizer cooling structure. The cooling water flow rate determination module is used to determine the cooling water flow rate of the second crystallizer cooling structure based on the cooling water flow velocity of the second crystallizer cooling structure, so as to achieve thermal equivalence between the second crystallizer cooling structure and the first crystallizer cooling structure through the cooling water flow rate of the second crystallizer cooling structure.

8. An electronic device, characterized in that, The electronic device includes: a processor and a memory storing computer program instructions; the processor reads and executes the computer program instructions to implement the method for determining the cooling water flow rate of a crystallizer based on thermal equivalence as described in any one of claims 1-6.

9. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores computer program instructions, which, when executed by a processor, implement the method for determining the flow rate of crystallizer cooling water based on thermal equivalence as described in any one of claims 1-6.

10. A computer program product, characterized in that, When the instructions in the computer program product are executed by the processor of the electronic device, the electronic device performs the method for determining the flow rate of the crystallizer cooling water based on thermal equivalence as described in any one of claims 1-6.

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