A method, medium and device for predicting resistance loss in flow channel of casting roller

Abstract

The present invention is applied in actual engineering manufacturing scenarios, and in particular provides a method, medium and equipment for analyzing and predicting the resistance loss of the flow channel inside a casting roller. By obtaining the diameter, spiral rise angle, water inlet head number, inlet flow velocity and density ρ of the spiral flow channel inside the casting roller, the total length of the spiral line, the width of the flow channel, the hydraulic diameter of the flow channel and the average water flow velocity are obtained according to the diameter, spiral rise angle and water inlet head number of the spiral flow channel inside the casting roller; without considering the resistance correction coefficient, the resistance loss of water is obtained according to the inlet flow velocity and density; the resistance loss of water is linearly fitted with the actual resistance loss in the spiral flow channel obtained by three-dimensional simulation to obtain a dimensionless resistance coefficient; according to the relationship between the dimensionless resistance coefficient and the local loss in the pipeline, the resistance loss prediction result in the spiral flow channel is obtained. This method can quickly calculate the pressure loss of the flow channel inside the casting roller through calculation, analysis and fitting of a large amount of data.

Description

Technical Field

[0001] The invention relates to a method for predicting resistance loss in a flow channel, and in particular to a method, medium and equipment for predicting resistance loss in a flow channel inside a large-sized heated casting roller. Background Art

[0002] In the process of manufacturing film by casting roller, the heat inside and outside the roller needs to be transferred through the water inside the flow channel and the casting roller. Therefore, the flow process of water in the flow channel is crucial to the final cooling effect of the film. The higher the flow rate, the better the temperature consistency of the outer surface of the roller. However, the higher the flow rate, the greater the resistance loss. Since the flow channel inside the casting roller is spiral, affected by the complex structure of the flow channel inside the casting roller, the water generates considerable pressure loss during the flow process. Excessive pressure loss in the flow channel will lead to excessive inlet pressure, pressure drop of the fluid in the pipeline, and other consequences, which will have an adverse effect on the manufacture of cast film.

[0003] At present, the pressure drop in the flow channel is calculated only by measuring the inlet and outlet pressures. Once the pressure loss inside the casting roller flow channel exceeds the set range, it will cause huge economic losses. However, the existing calculation of the resistance loss in the spiral flow channel is to make the flow condition of the spiral flow channel equivalent to the flow in the viscous fluid pipeline, so that it can be applied to the local loss calculation formula in the pipeline. However, there is a dimensionless along-the-line loss coefficient λ in this formula. λ is related to the viscosity of the fluid, the Reynolds number and the general wall roughness, and cannot be directly calculated, resulting in the inability to accurately predict the pressure loss inside the casting roller flow channel.

[0004] Therefore, it is necessary to propose a method for predicting the resistance loss in the flow channel of a casting roller to solve the problem of low accuracy in predicting the pressure loss inside the flow channel of the existing casting roller. Summary of the invention

[0005] The present application provides a method, medium and device for predicting the resistance loss in the flow channel of a casting roller, so as to solve the above-mentioned problem existing in the prior art, that is, the problem of low accuracy in predicting the pressure loss inside the flow channel of the casting roller in the prior art. The present application provides a method for predicting the resistance loss in the flow channel of a casting roller, the method comprising:

[0006] Obtain the diameter, spiral angle, number of water inlet heads, inlet flow velocity and density ρ of the spiral flow channel in the casting roller;

[0007] According to the diameter, spiral angle and water inlet head of the spiral flow channel, the total length of the spiral line, the width of the flow channel, the hydraulic diameter of the flow channel and the average water flow velocity in the flow channel are obtained;

[0008] Without considering the resistance correction coefficient, the water resistance loss is obtained according to the inlet velocity and density of the water in the flow channel. The water resistance loss is linearly fitted with the actual resistance loss in the spiral flow channel obtained by three-dimensional simulation to obtain the dimensionless resistance coefficient.

[0009] According to the relationship between the dimensionless resistance coefficient and the local loss in the pipeline, the resistance loss prediction result in the spiral flow channel is obtained.

[0010] Optionally, the method further includes:

[0011] The spiral flow channel is a rectangular parallelepiped tubular flow channel with a rectangular cross-section; the height of the spiral flow channel is the height of the rectangular parallelepiped pipe, the flow channel width is equivalent to the width of the rectangular parallelepiped tubular flow channel, and the length of the spiral line is the length of the rectangular parallelepiped pipe.

[0012] Optionally, the total length of the spiral line, the width of the flow channel, the hydraulic diameter of the flow channel and the average water flow rate in the flow channel are obtained according to the diameter of the spiral flow channel, the spiral rise angle and the number of water inlet heads, specifically including:

[0013] The total length of the spiral is calculated using the following formula:

[0014] S G =πD n tanα

[0015]

[0016] Among them, D n is the inner end diameter of the casting roll, S G is the pitch of the spiral line on the spiral flow channel, L is the axial length of the casting roller, and α is the helical rise angle of the spiral flow channel;

[0017] The spiral flow channel width is calculated using the following formula:

[0018]

[0019] The hydraulic diameter of the flow channel is calculated using the following formula:

[0020]

[0021] Among them, dx is the height of the spiral flow channel, dy is the width of the spiral flow channel, and n is the number of water inlet heads;

[0022] The average water flow rate in the flow channel is calculated using the following formula:

[0023]

[0024] Among them, u in is the inlet flow rate, D in is the inner diameter of the liquid water inlet.

[0025] Optionally, the water resistance loss is calculated using the following formula:

[0026]

[0027] Where g is the acceleration due to gravity.

[0028] Optionally, the following formula is used to calculate the predicted result of the resistance loss in the spiral flow channel:

[0029]

[0030] Where λ is the dimensionless drag coefficient.

[0031] The present application provides a computer-readable storage medium, wherein the storage medium stores a computer program, and when the computer program is executed by a processor, the method for predicting the resistance loss in the flow channel of a casting roller is implemented.

[0032] The present application provides a computer device, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the program, the method for predicting the resistance loss in the flow channel of the casting roller is implemented.

[0033] Compared with the prior art, the beneficial effects of the present application are as follows: The present application provides a method for predicting the resistance loss in the flow channel of a casting roller, which analyzes the model parameters of the casting roller obtained, obtains the resistance loss of water according to the flow parameters of water in the flow channel without considering the resistance correction coefficient, linearly fits the resistance loss of water with the actual resistance loss in the spiral flow channel obtained by three-dimensional simulation, and obtains a dimensionless resistance coefficient, and then obtains the resistance loss prediction result in the spiral flow channel according to the dimensionless resistance coefficient and the calculation formula for local loss in the pipeline. In order to solve the problem of low accuracy in predicting the pressure loss inside the flow channel of the casting roller, accurate and rapid prediction of the pressure loss in the flow channel of the casting roller can be achieved through calculation analysis and fitting of a large amount of data. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application.

[0035] Figure 1 A flow chart of a method for predicting resistance loss in a casting roller flow channel provided by an embodiment of the present invention;

[0036] Figure 2 A schematic diagram of a spiral flow channel provided by an embodiment of the present invention;

[0037] Figure 3A schematic diagram of a spiral flow channel provided in an embodiment of the present invention being equivalent to a pipeline with a rectangular cross section;

[0038] Figure 4 A schematic diagram of a linear fitting result provided by an embodiment of the present invention;

[0039] Figure 5 It is a computer device schematic diagram of a method for predicting resistance loss in a casting roller flow channel provided by the present invention.

[0040] The above drawings have shown clear embodiments of the present application, which will be described in more detail later. These drawings and text descriptions are not intended to limit the scope of the present application in any way, but to illustrate the concept of the present application to those skilled in the art by referring to specific embodiments. DETAILED DESCRIPTION

[0041] In order to make the purpose, technical solutions and advantages of this application clearer, the technical solutions in this application will be clearly and completely described below in conjunction with the drawings in this application. Obviously, the described embodiments are part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0042] The terms "first", "second", "third", "fourth", etc. (if any) in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the numbers used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in sequences other than those illustrated or described herein, for example.

[0043] In the embodiments of the present application, the words "exemplary" or "for example" are used to indicate examples, illustrations or descriptions. Any embodiment or design described as "exemplary" or "for example" in the present application should not be interpreted as being more preferred or more advantageous than other embodiments or designs. Specifically, the use of words such as "exemplary" or "for example" is intended to present related concepts in a specific way.

[0044] Since the internal flow channel of the casting roller is spiral, affected by the complex structure of the internal flow channel of the casting roller, the cooling water generates considerable pressure loss during the flow process, which will have an adverse effect on the manufacture of the cast film.

[0045] Currently, the pressure drop in the flow channel is calculated only by measuring the inlet and outlet pressures, which results in a low accuracy in predicting the pressure loss inside the flow channel of the casting roller. Once the pressure loss inside the flow channel of the casting roller exceeds the set range, it will cause huge economic losses.

[0046] In response to the above problems, the present application provides a method for predicting the resistance loss in the flow channel of a casting roller. The method analyzes the model parameters of the casting roller, and linearly fits the resistance loss of water with the actual resistance loss in the spiral flow channel obtained by three-dimensional simulation without considering the resistance correction coefficient to obtain a dimensionless resistance coefficient; the resistance loss prediction result in the spiral flow channel is obtained through the relationship between the dimensionless resistance coefficient and the local loss in the pipeline. In response to the problem of low accuracy in predicting the pressure loss inside the flow channel of the casting roller, the calculation analysis and fitting of the data can be used to accurately and quickly predict the pressure loss of the flow channel of the casting roller, effectively improving the accuracy of the pressure loss prediction of the flow channel of the casting roller, and the method does not require the construction and pre-processing of the model, further improving the convenience of subsequent flow channel design.

[0047] The technical solution of the present application and how the technical solution of the present application solves the above-mentioned technical problems are described in detail below with specific embodiments. The following specific embodiments can be combined with each other, and the same or similar concepts or processes may not be repeated in some embodiments. The embodiments of the present application will be described below in conjunction with the accompanying drawings.

[0048] Figure 1 is a flow chart of a method for predicting the resistance loss in the flow channel of a casting roller provided in an embodiment of the present application, such as Figure 1 As shown, this embodiment shows a method for predicting the resistance loss in the flow channel of a casting roller, comprising:

[0049] S1: Obtain the diameter, spiral angle, number of water inlet heads, inlet flow rate and density ρ of the spiral flow channel in the casting roller

[0050] S2: According to the diameter, spiral angle and water inlet head number of the spiral flow channel in the casting roller, the total length of the spiral line, the width of the flow channel, the hydraulic diameter of the flow channel and the average water flow rate in the flow channel are obtained.

[0051] like Figure 2 As shown in the figure, in this step, the specific calculation formula for the total length of the spiral is:

[0052] S G =πD n tanα

[0053]

[0054] Among them, D n is the inner end diameter of the casting roll, S G is the pitch of the spiral line on the spiral flow channel, L is the axial length of the casting roller, and α is the helical rise angle of the spiral flow channel.

[0055] like Figure 3 As shown, the spiral flow channel can be stretched straight and equivalent to a rectangular tubular flow channel with a rectangular cross-section; wherein the height of the spiral flow channel is the height of the rectangular pipeline, the flow channel width can be equivalent to the width of the rectangular pipeline, and the length of the spiral line is the length of the rectangular pipeline.

[0056] The specific calculation formula for the width of the spiral flow channel is:

[0057]

[0058] The specific calculation formula for the hydraulic diameter of the flow channel is:

[0059]

[0060] Among them, dx is the height of the spiral flow channel, dy is the width of the spiral flow channel, and n is the number of water inlet heads.

[0061] The specific calculation formula for the average water flow velocity in the flow channel is:

[0062]

[0063] Among them, u in is the inlet flow rate, D in is the inner diameter of the liquid water inlet.

[0064] S3: Without considering the resistance correction coefficient, the water resistance loss is obtained according to the flow parameters of the water in the flow channel.

[0065] In this step, the specific calculation formula for the resistance loss without considering the resistance loss coefficient along the way is:

[0066]

[0067] Where g is the acceleration due to gravity.

[0068] S4: Linearly fit the water resistance loss with the actual resistance loss in the spiral flow channel obtained by three-dimensional simulation to obtain a dimensionless resistance coefficient.

[0069] like Figure 4 As shown in the schematic diagram of the linear fitting result, it can be seen that the pressure loss calculation result without considering the resistance loss coefficient has a good linear fitting effect with the three-dimensional actual calculation result, and the slope of the straight line obtained by fitting is the resistance loss coefficient λ.

[0070] S5: Based on the dimensionless resistance coefficient and the calculation formula for local loss in the pipeline, the resistance loss prediction result in the spiral flow channel is obtained.

[0071] The specific calculation formula of the corrected resistance loss is:

[0072]

[0073] Where λ is the dimensionless drag coefficient.

[0074] Among them, the local loss calculation formula in the pipeline is a calculation formula for calculating the resistance loss of the flow in the pipeline of viscous fluid, and is applicable to fully developed laminar flow and turbulent flow in smooth and rough pipes of any cross-sectional shape. The resistance loss calculation in the spiral flow channel in this application is achieved by equating the flow condition of the spiral flow channel to the flow in the pipeline of viscous fluid, calculating the resistance loss without considering λ through the local loss calculation formula in the pipeline and the result of the three-dimensional simulation calculation by linear fitting to obtain λ, thereby obtaining the resistance loss result in the spiral flow channel.

[0075] This embodiment provides a method for predicting the resistance loss in the flow channel of a casting roller, by obtaining the diameter, spiral rise angle, water inlet head number, inlet flow velocity and density ρ of the spiral flow channel in the casting roller; according to the diameter, spiral rise angle and water inlet head number of the spiral flow channel, the total length of the spiral line, the flow channel width, the hydraulic diameter of the flow channel and the average water flow velocity in the flow channel are obtained; without considering the resistance correction coefficient, the resistance loss of water is obtained according to the flow parameters of water in the flow channel, and the resistance loss of water is linearly fitted with the actual resistance loss in the spiral flow channel obtained by three-dimensional simulation to obtain a dimensionless resistance coefficient; according to the relationship between the dimensionless resistance coefficient and the local loss in the pipeline, the resistance loss prediction result in the spiral flow channel is finally obtained. Aiming at the problem of low accuracy in predicting the pressure loss inside the flow channel of the casting roller, the pressure loss of the casting roller flow channel can be accurately and quickly predicted by calculating, analyzing and fitting a large amount of data, which effectively improves the accuracy of the pressure loss prediction of the casting roller flow channel, and the method does not need to go through the model building and pre-processing process, thereby further improving the convenience of subsequent flow channel design.

[0076] The present application also provides a computer-readable storage medium, which stores a computer program. The computer program can be used to execute the above-mentioned method for predicting the resistance loss in the flow channel of the casting roller.

[0077] This application also provides Figure 5 The structural diagram of the computer device shown in FIG. Figure 5 As shown, at the hardware level, the computer device includes a processor, an internal bus, a network interface, a memory, and a non-volatile memory, and may also include hardware required for other services. The processor reads the corresponding computer program from the non-volatile memory into the memory and then runs it to implement the method for predicting the resistance loss in the flow channel of the casting roller provided in the above embodiment.

[0078] Those of ordinary skill in the art can understand that all or part of the processes in the above-mentioned embodiment methods can be completed by instructing the relevant hardware through a computer program, and the computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above-mentioned methods. Among them, any reference to memory, storage, database or other media used in the embodiments provided in this application can include at least one of non-volatile and volatile memory. Non-volatile memory may include read-only memory (ROM), magnetic tape, floppy disk, flash memory or optical memory, etc. Volatile memory may include random access memory (RAM) or external cache memory. As an illustration and not limitation, RAM can be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM).

[0079] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this application.

Claims

1. A method for analyzing and predicting the flow channel resistance loss inside a casting roll, characterized in that: The method comprises: Obtain the diameter, spiral angle, number of water inlet heads, inlet flow velocity and density ρ of the spiral flow channel in the casting roller; According to the diameter, spiral angle and water inlet head of the spiral flow channel, the total length of the spiral line, the width of the flow channel, the hydraulic diameter of the flow channel and the average water flow velocity in the flow channel are obtained; The total length of the spiral line, the width of the flow channel, the hydraulic diameter of the flow channel and the average water flow rate in the flow channel are obtained according to the diameter of the spiral flow channel, the spiral rise angle and the number of water inlet heads, which specifically include: The total length of the spiral is calculated using the following formula: ； ； in, D n is the inner end diameter of the casting roller, S G is the pitch of the helix on the spiral channel, L is the axial length of the casting roller, α is the helical angle of the spiral flow channel; The spiral channel width is calculated using the following formula: ； The hydraulic diameter of the flow channel is calculated using the following formula: ； in, dx is the height of the spiral channel, dy is the width of the spiral channel, n is the number of water inlet heads; The average water flow rate in the flow channel is calculated using the following formula: ； in, u in is the inlet flow rate, D in is the inner diameter of the liquid water inlet; Without considering the resistance correction coefficient, the water resistance loss is obtained according to the inlet velocity and density of the water in the flow channel. The water resistance loss is linearly fitted with the actual resistance loss in the spiral flow channel obtained by three-dimensional simulation to obtain the dimensionless resistance coefficient. According to the relationship between the dimensionless resistance coefficient and the local loss in the pipeline, the resistance loss prediction result in the spiral flow channel is obtained; The predicted result of the resistance loss in the spiral flow channel is calculated using the following formula: ； in, λ is the dimensionless drag coefficient.

2. The method according to claim 1, characterized in that The method further comprises: The spiral flow channel is a rectangular parallelepiped tubular flow channel with a rectangular cross-section; the height of the spiral flow channel is the height of the rectangular parallelepiped pipe, the flow channel width is equivalent to the width of the rectangular parallelepiped tubular flow channel, and the length of the spiral line is the length of the rectangular parallelepiped pipe.

3. The method according to claim 1, characterized in that The water resistance loss is calculated using the following formula: ； in, g is the acceleration due to gravity.

4. A computer-readable storage medium, characterized in that: The storage medium stores a computer program, and when the computer program is executed by a processor, the method according to any one of claims 1 to 3 is implemented.

5. A computer device, characterized in that: The method comprises a memory, a processor and a computer program stored in the memory and executable on the processor, wherein when the processor executes the program, the method described in any one of claims 1 to 3 is implemented.

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