Method and device for acquiring convective heat transfer coefficient, electronic equipment and storage medium

Abstract

Embodiments of the present application disclose a method and device for obtaining a convective heat transfer coefficient, electronic equipment and a storage medium. The method comprises: obtaining a first basic parameter of each oil duct in a transformer and a second basic parameter of insulating oil in each oil duct, the first basic parameter comprising a radial diameter of the oil duct and an equivalent diameter of the oil duct; the second basic parameter comprising a density of the insulating oil, a dynamic viscosity of the insulating oil, a specific heat capacity of the insulating oil, a thermal conductivity of the insulating oil and a flow rate of the insulating oil; for each oil duct, a target Nusselt number of the insulating oil in the oil duct is calculated based on the first basic parameter and the second basic parameter; for the insulating oil in each oil duct, a convective heat transfer coefficient corresponding to the insulating oil in the oil duct is obtained through the target Nusselt number, and the convective heat transfer coefficient is used to reflect a heat exchange capacity of the insulating oil in each oil duct and a surface of a winding of the transformer. The embodiments of the present application improve the accuracy of the convective heat transfer coefficient.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of temperature detection, and in particular to a method and device for obtaining a convective heat transfer coefficient, an electronic device and a storage medium. BACKGROUND

[0002] With the increasing demand for energy, transformers are becoming increasingly important to power systems. As a kind of power equipment widely used in power systems, transformers are the main component of safe transmission and economic distribution of electric energy, and play a crucial role in the safe and stable operation of power systems.

[0003] Thermal calculation of transformers is very important for predicting hot spot temperature position in transformers and evaluating transformer life. However, the calculation accuracy of current thermal calculation of transformers is limited. Usually, the value of convective heat transfer coefficient involved in the calculation is not accurate enough, and therefore, a method for obtaining a convective heat transfer coefficient is needed to solve the above technical problems. SUMMARY

[0004] The embodiments of the present application provide a method and device for obtaining a convective heat transfer coefficient, an electronic device and a storage medium to solve the above technical problems.

[0005] In a first aspect, the embodiments of the present application provide a method for obtaining a convective heat transfer coefficient, comprising:

[0006] Obtaining a first basic parameter of each oil duct in a transformer and a second basic parameter of insulating oil in each oil duct, wherein the first basic parameter includes a radial diameter of the oil duct and an equivalent diameter of the oil duct; and the second basic parameter includes a density of the insulating oil, a dynamic viscosity of the insulating oil, a specific heat capacity of the insulating oil, a thermal conductivity of the insulating oil and a flow rate of the insulating oil;

[0007] For each oil duct, a target Nusselt number of the insulating oil in the oil duct is calculated based on the first basic parameter and the second basic parameter;

[0008] For the insulating oil in each oil duct, a convective heat transfer coefficient corresponding to the insulating oil in the oil duct is obtained through the target Nusselt number, and the convective heat transfer coefficient is used to reflect the heat exchange capacity of the insulating oil in each oil duct and the surface of the transformer winding.

[0009] In a second aspect, the embodiments of the present application also provide a device for obtaining a convective heat transfer coefficient, comprising:

[0010] The parameter acquisition module is configured to acquire a first basic parameter of each oil duct in the transformer and a second basic parameter of insulating oil in each oil duct, wherein the first basic parameter comprises a radial diameter of the oil duct and an equivalent diameter of the oil duct; and the second basic parameter comprises a density of the insulating oil, a dynamic viscosity of the insulating oil, a specific heat capacity of the insulating oil, a thermal conductivity coefficient of the insulating oil, and a flow rate of the insulating oil;

[0011] The target Nusselt number acquisition module is configured to acquire, for each oil duct, a target Nusselt number of insulating oil in the oil duct based on the first basic parameter and the second basic parameter.

[0012] The convective heat transfer coefficient acquisition module is configured to acquire, for insulating oil in each oil duct, a convective heat transfer coefficient corresponding to the insulating oil in the oil duct by using the target Nusselt number, wherein the convective heat transfer coefficient is used to reflect a heat exchange capacity of the insulating oil in each oil duct and a surface of a winding of the transformer.

[0013] In a third aspect, an electronic device is provided, and the electronic device includes:

[0014] One or more processors;

[0015] A storage device configured to store one or more programs,

[0016] When the one or more programs are executed by the one or more processors, the one or more processors implement the method for acquiring a convective heat transfer coefficient as described in any of the embodiments of the present application.

[0017] In a fourth aspect, a storage medium containing computer executable instructions is provided, and the computer executable instructions are used to execute the method for acquiring a convective heat transfer coefficient as described in any of the embodiments of the present application when executed by a computer processor.

[0018] The technical solution of the embodiments of the present application acquires a first basic parameter of each oil duct in the transformer and a second basic parameter of insulating oil in each oil duct, acquires, for each oil duct, a target Nusselt number of insulating oil in the oil duct based on the first basic parameter and the second basic parameter, and acquires, for insulating oil in each oil duct, a convective heat transfer coefficient corresponding to the insulating oil in the oil duct by using the target Nusselt number, wherein the convective heat transfer coefficient is used to reflect a heat exchange capacity of the insulating oil in each oil duct and a surface of a winding of the transformer. The target Nusselt number acquired by the embodiments of the present application is acquired based on the first basic parameter and the second basic parameter, and the influence of the dynamic viscosity of the insulating oil on the target Nusselt number due to temperature change is considered, so that the target Nusselt number is more in line with the characteristics of the oil duct and the insulating oil in the oil duct. Furthermore, the convective heat transfer coefficient calculated based on the target Nusselt number is more accurate and more targeted. BRIEF DESCRIPTION OF DRAWINGS

[0019] In order to make the technical solutions in the embodiments of the present application or the prior art clearer, the accompanying drawings needed in the embodiments or prior art description will be briefly introduced. Obviously, the accompanying drawings in the following description only aim to some embodiments of the present application, and other drawings can be obtained by those skilled in the art without any creative effort on the basis of these drawings.

[0020] Wherein:

[0021] Figure 1 A flowchart of a method for obtaining a convective heat transfer coefficient in an embodiment;

[0022] Figure 2 A structural diagram of a device for obtaining a convective heat transfer coefficient in another embodiment;

[0023] Figure 3 A structural diagram of an electronic device in another embodiment. DETAILED DESCRIPTION

[0024] The technical solutions in the embodiments of the present application will be described clearly and completely with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only some embodiments of the present application, but not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without any creative effort belong to the protection scope of the present application.

[0025] In an embodiment of the present application, a method for obtaining a convective heat transfer coefficient is provided. The embodiment of the present application can be applied to the case of obtaining a convective heat transfer coefficient corresponding to insulation oil and winding in each oil duct. The method can be realized by a device for obtaining a convective heat transfer coefficient. The device can be realized in the form of software and / or hardware. For example, the software can be application software, and the hardware can be a computer in which a program for realizing the method for obtaining a convective heat transfer coefficient is stored.

[0026] As shown in Figure 1 The method for obtaining a convective heat transfer coefficient provided by the embodiment of the present application includes:

[0027] S110, obtaining a first basic parameter of each oil duct in a transformer and a second basic parameter of insulation oil in each oil duct.

[0028] The transformer in the embodiment of the present application comprises an oil-immersed transformer. The insulating oil in the oil duct of the transformer is also referred to as transformer oil. The first basic parameters comprise the radial diameter of the oil duct of the transformer and the equivalent diameter of the oil duct of the transformer; the radial diameter of the oil duct refers to the radial diameter of the oil duct parallel to the horizontal plane. The second basic parameters comprise the density of the insulating oil, the dynamic viscosity of the insulating oil, the specific heat capacity of the insulating oil, the thermal conductivity coefficient of the insulating oil and the flow rate of the insulating oil. The first basic parameters of the oil duct of the transformer and the second basic parameters of the insulating oil in the oil duct of the transformer can be obtained by sensors. Of course, the first basic parameters and the second basic parameters can be pre-set, and the pre-set first basic parameters and the second basic parameters are directly obtained. The oil duct of the transformer comprises at least one. Of course, it can be two, three and multiple.

[0029] Specifically, first, the first basic parameters and the second basic parameters are obtained, which prepares for the subsequent obtaining of the target Nusselt number.

[0030] In S120, for each oil duct, the target Nusselt number of the insulating oil in the oil duct is calculated based on the first basic parameters and the second basic parameters.

[0031] In the embodiment of the present application, the target Nusselt number is calculated based on the first basic parameters and the second basic parameters. This step prepares for the subsequent calculation of the convective heat transfer coefficient based on the target Nusselt number. Since the target Nusselt number is calculated based on the first basic parameters of the oil duct of the transformer and the second basic parameters of the insulating oil in the oil duct of the transformer, the target Nusselt number is more suitable for the characteristics of the oil duct of the insulating oil, and thus the subsequently calculated convective heat transfer coefficient can conform to the characteristics of the insulating oil in each oil duct, so that the accuracy of the convective heat transfer coefficient is higher.

[0032] In S130, for the insulating oil in each oil duct, the convective heat transfer coefficient corresponding to the insulating oil in the oil duct is obtained through the target Nusselt number.

[0033] The convective heat transfer coefficient is used to reflect the heat exchange capacity of the insulating oil in each oil duct and the surface of the transformer winding.

[0034] In the embodiment of the present application, the convective heat transfer coefficient is calculated based on the target Nusselt number of the insulating oil in each oil duct. Since the accuracy of the target Nusselt number is improved, the accuracy of the convective heat transfer coefficient is also improved. The convective heat transfer coefficient is used to reflect the heat exchange capacity of the insulating oil in each oil duct and the surface of the transformer winding. The accuracy of the convective heat transfer coefficient makes the thermal calculation of the transformer related to the convective heat transfer coefficient more accurate.

[0035] The technical scheme of the embodiment of the present application obtains the first basic parameter of each oil duct in the transformer and the second basic parameter of the insulating oil in each oil duct, calculates the target Nusselt number of the insulating oil in each oil duct based on the first basic parameter and the second basic parameter, and obtains the convective heat transfer coefficient corresponding to the insulating oil in each oil duct based on the target Nusselt number. The convective heat transfer coefficient is used to reflect the heat exchange capacity of the insulating oil in each oil duct and the winding surface of the transformer. The target Nusselt number obtained by the embodiment of the present application is obtained based on the first basic parameter and the second basic parameter, and the influence of the dynamic viscosity of the insulating oil on the target Nusselt number due to temperature change is considered, which is more in line with the characteristics of the oil duct and the insulating oil in the oil duct. Furthermore, the convective heat transfer coefficient obtained based on the target Nusselt number is more accurate.

[0036] Optionally, after obtaining the convective heat transfer coefficient, the convective heat transfer coefficient is set as a boundary condition of heat transfer between the transformer winding and the insulating oil in the finite element analysis, thereby simplifying the boundary layer partition in the finite element analysis calculation and accelerating the operation speed.

[0037] In another embodiment of the present application, the obtaining, for the insulating oil in each oil duct, the convective heat transfer coefficient corresponding to the insulating oil in the oil duct based on the target Nusselt number comprises: calculating, for the insulating oil in each oil duct, the convective heat transfer coefficient corresponding to the insulating oil in the oil duct based on a predetermined convective heat transfer coefficient formula. wherein h is the convective heat transfer coefficient, Nu is the target Nusselt number, k is the thermal conductivity, and D is the equivalent diameter of the oil duct.

[0038] In the embodiment of the present application, the target Nusselt number, the equivalent diameter of the oil duct, and the thermal conductivity are calculated based on the predetermined convective heat transfer coefficient formula to obtain the convective heat transfer coefficient.

[0039] In another embodiment of the present application, the calculating, based on the first basic parameter and the second basic parameter, the target Nusselt number of the insulating oil in the oil duct comprises: calculating a Reynolds number based on the flow rate of the insulating oil, the density of the insulating oil, the dynamic viscosity of the insulating oil, and the equivalent diameter of the oil duct; calculating a Prandtl number based on the specific heat capacity of the insulating oil, the dynamic viscosity of the insulating oil, and the thermal conductivity of the insulating oil; and calculating the target Nusselt number of the insulating oil in the oil duct based on the Reynolds number, the Prandtl number, the radial diameter of the oil duct of the transformer, the equivalent diameter of the oil duct of the transformer, the dynamic viscosity of the insulating oil at the winding temperature, the dynamic viscosity of the insulating oil at the insulating oil flow field temperature, and a predetermined target coefficient.

[0040] In the embodiment of the present application, the Reynolds number is obtained by calculating the flow rate of the insulating oil, the density of the insulating oil, the dynamic viscosity of the insulating oil and the equivalent diameter of the oil duct through a predetermined Reynolds number formula. The Prandtl number is obtained by calculating the specific heat capacity of the insulating oil, the dynamic viscosity of the insulating oil and the thermal conductivity coefficient of the insulating oil through a predetermined Prandtl number formula. The target Nusselt number of the insulating oil in the oil duct is calculated based on the Reynolds number, the Prandtl number, the radial diameter of the oil duct of the transformer, the equivalent diameter of the oil duct of the transformer, the dynamic viscosity of the insulating oil at the winding temperature, the dynamic viscosity of the insulating oil at the insulating oil flow field temperature and a predetermined target coefficient.

[0041] For example, the predetermined Reynolds number formula includes: wherein R is the Reynolds number, v is the flow rate of the insulating oil, p is the density of the insulating oil, D is the equivalent diameter of the oil duct and μ is the dynamic viscosity of the insulating oil. The predetermined Prandtl number formula includes: wherein P is the Prandtl number, c is the specific heat capacity of the insulating oil and λ is the thermal conductivity coefficient of the insulating oil.

[0042] Optionally, the target Nusselt number of the insulating oil in the oil duct is calculated based on the Reynolds number, the Prandtl number, the radial diameter of the oil duct of the transformer, the equivalent diameter of the oil duct of the transformer, the dynamic viscosity of the insulating oil at the winding temperature, the dynamic viscosity of the insulating oil at the insulating oil flow field temperature and a predetermined target coefficient, which includes: the target Nusselt number of the insulating oil in the oil duct is obtained by calculating the Reynolds number, the Prandtl number, the radial diameter of the oil duct of the transformer, the equivalent diameter of the oil duct of the transformer, the dynamic viscosity of the insulating oil at the winding temperature, the dynamic viscosity of the insulating oil at the insulating oil flow field temperature and a predetermined target coefficient through a second Nusselt number formula, and the second Nusselt number formula is: wherein Nu is the target Nusselt number, a, b and n are the first coefficient, the second coefficient and the third coefficient in sequence, the target coefficient is composed of a, b and n; L is the radial diameter of the oil duct, R is the Reynolds number, P is the Prandtl number, D is the equivalent diameter of the oil duct, μ1 is the dynamic viscosity of the insulating oil at the winding temperature and μ2 is the dynamic viscosity of the insulating oil at the insulating oil flow field temperature.

[0043] In the embodiment of the present application, the target Nusselt number of the oil channel is obtained by calculating the Reynolds number, the Prandtl number, the radial diameter of the oil channel of the transformer, the equivalent diameter of the oil channel of the transformer, the dynamic viscosity of the insulating oil at the winding temperature, the dynamic viscosity of the insulating oil at the insulating oil flow field temperature, and the predetermined target coefficient by the second Nusselt number formula. The second Nusselt number formula in the embodiment of the present application is a formula set according to the characteristics of the oil channel of the transformer and the temperature characteristics of the insulating oil. The target Nusselt number calculated by the second Nusselt number formula is more accurate and more in line with the characteristics of the corresponding oil channel and the insulating oil in the oil channel. Therefore, the accuracy of the thermal calculation of the transformer can be improved.

[0044] The target Nusselt number of the embodiment of the present application can improve the accuracy of the convective heat transfer coefficient when calculating the convective heat transfer coefficient of the insulating oil and the winding. In the thermal calculation of the transformer, the convective heat transfer coefficient is needed. The thermal calculation is, for example, the calculation of the hot spot temperature of the transformer, and for example, the calculation of the hot spot temperature of the winding in the transformer. Therefore, the acquisition of the convective heat transfer coefficient in the embodiment of the present application can improve the accuracy of the subsequent thermal calculation of the transformer.

[0045] In another embodiment of the present application, the target coefficient is included in the second Nusselt number formula, and the target coefficient includes a first coefficient, a second coefficient, and a third coefficient. The target coefficient in the embodiment of the present application can be determined based on the characteristics of the oil channel and the characteristics of the insulating oil. Optionally, the method further comprises: determining the target coefficient; the determination of the target coefficient comprises: establishing a two-dimensional oil channel model of each oil channel of the transformer; in each two-dimensional oil channel model, fluid mechanics simulation is performed to obtain a plurality of groups of heat transfer parameters under constant heat generation power, the heat transfer parameters including the temperature of the winding surface wall in the oil channel and the temperature of the insulating oil flow field; for each oil channel, each group of heat transfer parameters is input into the first Nusselt number formula to obtain a plurality of first Nusselt numbers of the insulating oil in the oil channel; the first Nusselt number formula is: wherein Nu1 is the first Nusselt number, q is the heat flux density, D is the equivalent diameter of the oil channel, k is the thermal conductivity, t1 is the temperature of the winding surface wall in the oil channel, and t2 is the temperature of the insulating oil flow field; each first Nusselt number is processed by the to-be-corrected Nusselt number formula to obtain a plurality of groups of to-be-corrected coefficients; the second Nusselt number formula refers to the to-be-corrected Nusselt number formula in which the target coefficient is determined; and the target coefficient is obtained from the plurality of groups of to-be-corrected coefficients.

[0046] Exemplarily,

[0047] In the embodiment of the present application, a two-dimensional oil duct model of each oil duct of the transformer is established, in each two-dimensional oil duct model, fluid mechanics simulation is performed to obtain temperature distribution under constant heat power, that is, the temperature of each position in the oil duct, and a set of heat transfer parameters is obtained from the temperature of each position. In the embodiment of the present application, a plurality of sets of to-be-modified heat transfer coefficients are obtained, the heat transfer parameters include the temperature of the winding surface wall in the oil duct and the temperature of the insulating oil flow field. For each oil duct, a first Nusselt number formula is used to calculate each set of heat transfer parameters to obtain a plurality of first Nusselt numbers of the insulating oil in the oil duct. Each first Nusselt number is calculated by a to-be-modified Nusselt number formula to obtain a plurality of sets of to-be-modified coefficients, and a target coefficient is obtained from the plurality of sets of to-be-modified coefficients. The first Nusselt number formula refers to the existing conventional Nusselt number formula.

[0048] For example, after obtaining the plurality of sets of to-be-modified coefficients, each set of to-be-modified coefficients is substituted into the to-be-modified Nusselt number formula to obtain a to-be-processed Nusselt number formula corresponding to each set of to-be-modified coefficients. Based on the first to-be-comparison value calculated by the to-be-processed Nusselt number formula, the second to-be-comparison value obtained by the CFD software under the same first basic parameter and second basic parameter, and the correlation coefficient between the first to-be-comparison value and the second to-be-comparison value is calculated. Through the above steps, the correlation coefficient corresponding to each set of to-be-modified coefficients can be obtained. The to-be-modified coefficient corresponding to the maximum correlation coefficient is determined as the target coefficient.

[0049] The CFD software is the abbreviation of Computational fluid Dynamics software, which can be used to calculate the Nusselt number. In another embodiment of the present application, the two-dimensional oil duct model of each oil duct of the transformer is established, including: for each oil duct of the transformer, a two-dimensional oil duct model of the oil duct is established based on the radial diameter of the oil duct and the axial diameter of the oil duct.

[0050] In the embodiment of the present application, for the two-dimensional oil duct model, the two-dimensional oil duct model is obtained through the radial diameter of the oil duct and the axial diameter of the oil duct. For example, the comsol finite element software can be used to process the radial diameter of the oil duct and the axial diameter of the oil duct to construct the two-dimensional oil duct model. Alternatively, the radial diameter of the oil duct herein refers to the radial diameter of the oil duct parallel to the horizontal plane. The axial diameter refers to the axial diameter of the oil duct parallel to the horizontal plane.

[0051] In another embodiment of the application, after the two-dimensional oil channel model of each oil channel of the transformer is established, the method further comprises: obtaining the oil temperature at the inlet and the oil flow speed at the inlet of different groups of the oil channel; and performing fluid mechanics simulation in each of the two-dimensional oil channel models to obtain a plurality of groups of heat transfer parameters under constant heat generation power, including: for each oil channel of the transformer, based on the oil temperature at the inlet and the oil flow speed at the inlet of different groups of the oil channel, performing fluid mechanics simulation by using the two-dimensional oil channel model to obtain the heat transfer parameters corresponding to the oil temperature at the inlet and the oil flow speed at the inlet of each group of the oil channel.

[0052] In the embodiment of the application, after the two-dimensional oil channel model is established, the oil temperature at the inlet and the oil flow speed at the inlet of different groups of the oil channel are obtained. For the two-dimensional oil channel model of each oil channel of the transformer, the oil temperature at the inlet and the oil flow speed at the inlet of different groups are input, and the heat transfer parameters corresponding to the oil temperature at the inlet and the oil flow speed at the inlet are calculated under constant heat generation power by fluid mechanics simulation. Through the technical scheme of the embodiment of the application, a plurality of groups of heat transfer parameters corresponding to each oil channel can be obtained, which prepares for subsequent calculation of target coefficients.

[0053] In another embodiment of the application, a device for obtaining a convective heat transfer coefficient is provided. The device can execute the method for obtaining a convective heat transfer coefficient provided in any embodiment of the application, and has a function module and beneficial effects corresponding to the execution method. As shown in the figure, the device comprises a parameter acquisition module 210, a target Nusselt number acquisition module 220, and a convective heat transfer coefficient acquisition module 230, wherein, Figure 2

[0054] The parameter acquisition module 210 is configured to acquire a first basic parameter of each oil channel in the transformer and a second basic parameter of insulating oil in each oil channel. The first basic parameter comprises a radial diameter of the oil channel and an equivalent diameter of the oil channel. The second basic parameter comprises a density of the insulating oil, a dynamic viscosity of the insulating oil, a specific heat capacity of the insulating oil, a thermal conductivity coefficient of the insulating oil, and a flow speed of the insulating oil.

[0055] The target Nusselt number acquisition module 220 is configured to, for each oil channel, calculate a target Nusselt number of the insulating oil in the oil channel based on the first basic parameter and the second basic parameter.

[0056] The convective heat transfer coefficient acquisition module 230 is configured to, for the insulating oil in each oil channel, obtain a convective heat transfer coefficient corresponding to the insulating oil in the oil channel by using the target Nusselt number. The convective heat transfer coefficient is used to reflect the heat exchange capacity of the insulating oil in each oil channel and the surface of the transformer winding.

[0057] Preferably, in the embodiment of the application, the target Nusselt number acquisition module 220 is further configured to: ​

[0058] a Reynolds number is calculated based on the flow rate of the insulating oil, the density of the insulating oil, the dynamic viscosity of the insulating oil and the equivalent diameter of the oil duct; a Prandtl number is calculated based on the specific heat capacity of the insulating oil, the dynamic viscosity of the insulating oil and the thermal conductivity coefficient of the insulating oil; and a target Nusselt number of the insulating oil in the oil duct is calculated based on the Reynolds number, the Prandtl number, the radial diameter of the oil duct of the transformer, the equivalent diameter of the oil duct of the transformer, the dynamic viscosity of the insulating oil at the winding temperature, the dynamic viscosity of the insulating oil at the insulating oil flow field temperature and the target coefficient.

[0059] Preferably, in the embodiment of the present application, the method further comprises:

[0060] a target coefficient determination module, configured to determine the target coefficient; the target coefficient determination module is further configured to: establish a two-dimensional oil duct model of each oil duct of the transformer; perform fluid mechanics simulation in each two-dimensional oil duct model to obtain a plurality of groups of heat transfer parameters under constant heat generation power, the heat transfer parameters including the temperature of the winding surface wall in the oil duct and the temperature of the insulating oil flow field; for each oil duct, calculate a plurality of first Nusselt numbers of the insulating oil in the oil duct by using a first Nusselt number formula on each group of heat transfer parameters; the first Nusselt number formula is: wherein Nu1 is the first Nusselt number, q is the heat flux density, D is the equivalent diameter of the oil duct, k is the thermal conductivity coefficient, t1 is the temperature of the winding surface wall in the oil duct and t2 is the temperature of the insulating oil flow field; process each first Nusselt number by using a to-be-corrected Nusselt number formula to obtain a plurality of groups of to-be-corrected coefficients; the second Nusselt number formula refers to the to-be-corrected Nusselt number formula in which the target coefficient is determined; and the target coefficient is obtained from the plurality of groups of to-be-corrected coefficients.

[0061] Preferably, in the embodiment of the present application, the device further comprises:

[0062] an insulating oil parameter acquisition module, configured to acquire the oil temperature at the inlet and the oil flow speed at the inlet of different groups of the oil ducts;

[0063] the target coefficient determination module is further configured to:

[0064] for each oil duct of the transformer, a two-dimensional oil duct model of the oil duct is established based on the radial diameter of the oil duct and the axial diameter of the oil duct.

[0065] Preferably, in the embodiment of the present application, the target coefficient determination module is further configured to:

[0066] For each oil duct of the transformer, based on the oil temperature at the inlet and the oil flow speed at the inlet of different groups of the oil duct, fluid mechanics simulation is performed by using the two-dimensional oil duct model to obtain the heat transfer parameter corresponding to the oil temperature at the inlet and the oil flow speed at the inlet of each group of the oil duct.

[0067] Preferably, in the embodiment of the present application, the target Nusselt number acquisition module 220 is further configured to:

[0068] The target Nusselt number of the oil duct is obtained by calculating the Reynolds number, the Prandtl number, the radial diameter of the oil duct of the transformer, the equivalent diameter of the oil duct of the transformer, the dynamic viscosity of the insulating oil at the winding temperature, the dynamic viscosity of the insulating oil at the insulating oil flow field temperature, and the predetermined target coefficient through the second Nusselt number formula, and the second Nusselt number formula is: Wherein, Nu is the target Nusselt number, a, b and n are the first coefficient, the second coefficient and the third coefficient, respectively, and the target coefficient is composed of a, b and n; L is the radial diameter of the oil duct, R is the Reynolds number, P is the Prandtl number, D is the equivalent diameter of the oil duct, μ1 is the dynamic viscosity of the insulating oil at the winding temperature, and μ2 is the dynamic viscosity of the insulating oil at the insulating oil flow field temperature.

[0069] Preferably, in the embodiment of the present application, the convection heat transfer coefficient acquisition module 230 is further configured to:

[0070] For the insulating oil in each oil duct, the convection heat transfer coefficient corresponding to the insulating oil in the oil duct is obtained by calculating through a predetermined convection heat transfer coefficient formula; and the predetermined convection heat transfer coefficient formula is: Wherein, h is the convection heat transfer coefficient, Nu is the target Nusselt number, k is the thermal conductivity, and D is the equivalent diameter of the oil duct.

[0071] The technical scheme of the embodiment of the present application obtains the first basic parameter of each oil duct in the transformer and the second basic parameter of the insulating oil in each oil duct, for each oil duct, calculates the target Nusselt number of the insulating oil in the oil duct based on the first basic parameter and the second basic parameter, for the insulating oil in each oil duct, obtains the convection heat transfer coefficient corresponding to the insulating oil in the oil duct through the target Nusselt number, and the convection heat transfer coefficient is used to reflect the heat exchange capacity of the insulating oil in each oil duct and the surface of the transformer winding. The target Nusselt number obtained by the embodiment of the present application is obtained based on the first basic parameter and the second basic parameter, which is more in line with the characteristics of the oil duct and the insulating oil in the oil duct. Furthermore, the convection heat transfer coefficient obtained based on the target Nusselt number calculation is more accurate.

[0072] It is to be noted that the various modules included in the above apparatus are only divided according to the functional logic, and are not limited to the above division, as long as the corresponding functions can be realized; in addition, the specific names of the functional modules are only for the convenience of mutual differentiation, and do not serve to limit the protection scope of the embodiments of the present application.

[0073] In another embodiment of the application, Figure 3 A structural schematic diagram of an electronic device provided by the embodiments of the present application is shown. Figure 3 A block diagram of an exemplary electronic device 50 suitable for implementing the embodiments of the present application is shown. Figure 3 The electronic device 50 shown is merely an example, and should not bring any limitation to the functions and use range of the embodiments of the present application.

[0074] As Figure 3 shown, the electronic device 50 is in the form of a general-purpose computing device. The components of the electronic device 50 can include, but are not limited to, one or more processors or processing units 501, a system memory 502, and a bus 503 that couples various system components including the system memory 502 and the processing unit 501.

[0075] The bus 503 represents one or more of several types of bus structures, including a memory bus or memory controller, a peripheral bus, a graphics acceleration bus, a processor or local bus using any of a variety of bus architectures including an industry standard architecture (ISA), micro-channel architecture (MAC), enhanced ISA (EISA), Video Electronics Standards Association (VESA) local bus, and a peripheral component interconnect (PCI) bus.

[0076] The electronic device 50 typically includes a variety of computer system readable media. Such media can be any available media that is accessible by the electronic device 50 and includes both volatile and non-volatile media, removable and non-removable media.

[0077] The system memory 502 can include computer system readable media in the form of volatile memory, such as random access memory (RAM) 504 and / or cache memory 505. The electronic device 50 can further include other removable / non-removable, volatile / non-volatile computer system storage media. By way of example only, a storage system 506 can be provided for reading from and writing to non-removable, non-volatile magnetic media (e.g., a "hard drive"). Figure 3 not shown, commonly referred to as a "hard disk drive", for reading from and writing to non-removable, non-volatile magnetic media (e.g., a "hard drive"). Although not specifically shown, alternate embodiments can implement a magnetic floppy disk drive (FDD) or a magnetic tape drive for a floppy disk or magnetic cassette. As these elements are well known by those of ordinary skill in the art, no additional detail concerning these elements is provided. Figure 3A disk drive, a floppy disk drive, a CD-ROM drive, a DVD-ROM drive, or other removable media drive, or any combination thereof, can be provided in the exemplary computing device 50 for reading from and writing to a removable nonvolatile media (e.g., a floppy disk, a CD-ROM, a DVD-ROM, a Blu-ray Disc®, or another optical media). The removable nonvolatile media can be coupled to the computing device 50 by one or more of the data media interfaces 505. The memory 502 can include at least one program product 507 having a set (e.g., at least one) of program modules 508 that are configured to carry out the functions of embodiments of the application. The program / product 507 can be stored in the memory 502 by way of one or more of the data media interfaces 505.

[0078] The program / utility 508, having a set (at least one) of program modules 507, can be stored in memory 502 by way of the data media interfaces 505. The program modules 507 include, but are not limited to, an operating system, one or more applications, other program modules 507, and program data. Each of the operating system, the one or more applications, and other program modules 507 can include an implementation of a networking environment. The modules 507 are generally executed by the processor 501 to implement the techniques described herein.

[0079] The electronic device 50 can also communicate with one or more external devices 509 such as a keyboard or a pointing device, displays 510, etc.; one or more devices that enable a user to interact with the electronic device 50; and / or one or more devices that enable the electronic device 50 to communicate with one or more other computing devices. Such communication can be via the input / output (I / O) interfaces 511. Similarly, the electronic device 50 can communicate with one or more networks, such as a local area network (LAN), a wide area network (WAN), and / or the Internet via the network adapter 512. The network adapter 512 can be any of a variety of modems, including cable modem, digital subscriber line (DSL), and / or the like. It is to be appreciated that the network adapter 512 can be connected to the one or more networks either directly or via a wireless connection. Figure 3 Other hardware and / or software modules that can be used in conjunction with the electronic device 50 include, but are not limited to, microcode, device drivers, redundant processing units, external disk drive arrays, RAID systems, tape drives, and data archival storage systems, etc.

[0080] The processing unit 501 performs various functions, such as implementing the method for obtaining the convective heat transfer coefficient provided by embodiments of the application, by executing the program stored in the system memory 502.

[0081] In another embodiment of the application, a storage medium containing computer-executable instructions is also provided, which, when executed by a computer processor, are used to perform a method for obtaining the convective heat transfer coefficient, the method comprising:

[0082] The first basic parameters of each oil channel in the transformer and the second basic parameters of the insulating oil in each oil channel are acquired, the first basic parameters include the radial diameter of the oil channel and the equivalent diameter of the oil channel, and the second basic parameters include the density of the insulating oil, the dynamic viscosity of the insulating oil, the specific heat capacity of the insulating oil, the thermal conductivity coefficient of the insulating oil and the flow rate of the insulating oil; for each oil channel, the target Nusselt number of the insulating oil in the oil channel is calculated based on the first basic parameters and the second basic parameters; for the insulating oil in each oil channel, the convective heat transfer coefficient corresponding to the insulating oil in the oil channel is obtained through the target Nusselt number, and the convective heat transfer coefficient is used to reflect the heat exchange capacity of the insulating oil in each oil channel and the transformer winding surface.

[0083] The computer storage medium of the embodiment of the present application can adopt any combination of one or more computer readable media. The computer readable medium can be a computer readable signal medium or a computer readable storage medium. The computer readable storage medium may, for example, be, but is not limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, device or apparatus, or any combination thereof. More specific examples (non-exhaustive list) of the computer readable storage medium include an electrical connection having one or more wires, a portable computer diskette, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the above. In this document, the computer readable storage medium can be any tangible medium that contains or stores a program that can be used by or in connection with an instruction execution system, device or apparatus.

[0084] The computer readable signal medium can include a data signal propagated in a baseband or as a part of a carrier wave, in which a computer readable program code is borne. Such a propagated data signal can take on multiple forms, including but not limited to an electromagnetic signal, an optical signal or any suitable combination thereof. The computer readable signal medium can also be any computer readable medium that is not a computer readable storage medium and that can transmit, propagate or transport a program for use by or in connection with an instruction execution system, device or apparatus.

[0085] The program code contained on the computer readable medium can be transmitted by any suitable medium, including but not limited to wireless, wire, optical cable, RF, etc., or any suitable combination thereof.

[0086] Computer program code for carrying out operations of embodiments of the present application can be written in any combination of one or more programming languages, including an object oriented programming language such as Java, Smalltalk, C++ or the like, and conventional procedural programming languages, such as the "C" programming language or similar programming languages. The program code can execute entirely on the user's computer, partly on the user's computer, as a stand-alone software package, partly on the user's computer and partly on a remote computer or entirely on the remote computer or server. In the latter scenario, the remote computer can be connected to the user's computer through any type of network, including a local area network (LAN) or a wide area network (WAN), or the connection can be made to an external computer (for example, through the Internet using an Internet Service Provider).

[0087] The foregoing is considered as illustrative only of the principles of the application. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the application to the exact construction and practice described. Accordingly, all such variations are intended to be included within the scope of the present application as defined in the following claims.

Claims

1. A method of obtaining a convective heat transfer coefficient, characterized by, The method comprises: obtaining a first basic parameter of each oil duct in a transformer and a second basic parameter of insulation oil in each oil duct, the first basic parameter comprising a radial diameter of the oil duct and an equivalent diameter of the oil duct, and the second basic parameter comprising a density of the insulation oil, a dynamic viscosity of the insulation oil, a specific heat capacity of the insulation oil, a thermal conductivity of the insulation oil, and a flow rate of the insulation oil; for each oil duct, calculating a target Nusselt number of the insulation oil in the oil duct based on the first basic parameter and the second basic parameter; for the insulation oil in each oil duct, obtaining a convective heat transfer coefficient corresponding to the insulation oil in the oil duct through the target Nusselt number, the convective heat transfer coefficient being used to reflect a heat exchange capacity of the insulation oil in each oil duct and a winding surface of the transformer; the calculation of the target Nusselt number of the insulation oil in the oil duct based on the first basic parameter and the second basic parameter comprises: calculating a Reynolds number based on the flow rate of the insulation oil, the density of the insulation oil, the dynamic viscosity of the insulation oil, and the equivalent diameter of the oil duct; calculating a Prandtl number based on the specific heat capacity of the insulation oil, the dynamic viscosity of the insulation oil, and the thermal conductivity of the insulation oil; calculating the target Nusselt number of the insulation oil in the oil duct based on the Reynolds number, the Prandtl number, the radial diameter of the oil duct of the transformer, the equivalent diameter of the oil duct of the transformer, the dynamic viscosity of the insulation oil at a winding temperature, the dynamic viscosity of the insulation oil at an insulation oil flow field temperature, and a predetermined target coefficient.

2. The method of claim 1, wherein, The method further comprises: determining the target coefficient; the determination of the target coefficient comprises: establishing a two-dimensional oil duct model of each oil duct of the transformer; in each two-dimensional oil duct model, performing fluid mechanics simulation to obtain a plurality of sets of heat transfer parameters under a constant heat generating power, the heat transfer parameters comprising a winding surface wall temperature in the oil duct and an insulation oil flow field temperature; for each oil duct, calculating a plurality of first Nusselt numbers of the insulation oil in the oil duct through a first Nusselt number formula for each set of heat transfer parameters; the first Nusselt number formula is: ， wherein, N1 is the first Nusselt number, q q is the heat flux, D De is the equivalent diameter of the oil duct, k k is the thermal conductivity, t 1 is the temperature of the winding surface wall in the oil duct and t 2 is the temperature of the insulating oil flow field; processing each first Nusselt number through a to-be-corrected Nusselt number formula to obtain a plurality of sets of to-be-corrected coefficients; obtaining the target coefficient from the plurality of sets of to-be-corrected coefficients.

3. The method of claim 2, wherein the convective heat transfer coefficient is obtained by, The establishment of the two-dimensional oil duct model of each oil duct of the transformer comprises: for each oil duct of the transformer, establishing a two-dimensional oil duct model of the oil duct based on the radial diameter of the oil duct and the axial diameter of the oil duct.

4. The method of claim 2, wherein the heat transfer coefficient is obtained by, After the establishment of the two-dimensional oil duct model of each oil duct of the transformer, the method further comprises: obtaining oil temperatures at different groups of inlets of the oil duct and oil flow velocities at the inlets; the fluid mechanics simulation in each two-dimensional oil duct model to obtain a plurality of sets of heat transfer parameters under a constant heat generating power comprises: for each oil duct of the transformer, performing fluid mechanics simulation by using the two-dimensional oil duct model based on the oil temperatures at different groups of inlets of the oil duct and the oil flow velocities at the inlets to obtain heat transfer parameters corresponding to each set of oil temperature at the inlet and oil flow velocity at the inlet of the oil duct.

5. The method of obtaining a convective heat transfer coefficient according to claim 1, wherein, The target Nusselt number of the insulating oil in the oil duct is calculated based on the Reynolds number, the Prandtl number, the radial diameter of the oil duct of the transformer, the equivalent diameter of the oil duct of the transformer, the dynamic viscosity of the insulating oil at the winding temperature, the dynamic viscosity of the insulating oil at the insulating oil flow field temperature, and a predetermined target coefficient, and includes: The target Nusselt number of the insulating oil in the oil duct is calculated by a second Nusselt number formula based on the Reynolds number, the Prandtl number, the radial diameter of the oil duct of the transformer, the equivalent diameter of the oil duct of the transformer, the dynamic viscosity of the insulating oil at the winding temperature, the dynamic viscosity of the insulating oil at the insulating oil flow field temperature, and a predetermined target coefficient, and the second Nusselt number formula is a to-be-corrected Nusselt number formula in which the target coefficient is determined; The second Nusselt number formula is: ， wherein, Nu is a target Nusselt number, a , b and n consisting of a first coefficient, a second coefficient and a third coefficient, respectively, by a , b and n comprise a target coefficient; L is a radial diameter of the oil duct, R is a Reynolds number, P is a Prandtl number, D is an equivalent diameter of the oil duct, is a dynamic viscosity of the insulating oil at a winding temperature and is a dynamic viscosity of the insulating oil at an insulating oil flow field temperature.

6. The method of claim 1, wherein, The convective heat transfer coefficient corresponding to the insulating oil in the oil duct is obtained based on the target Nusselt number for the insulating oil in each oil duct, and includes: The convective heat transfer coefficient corresponding to the insulating oil in the oil duct is calculated based on a predetermined convective heat transfer coefficient formula for the insulating oil in each oil duct; and the predetermined convective heat transfer coefficient formula is: ， wherein, h is the convective heat transfer coefficient, Nu is the target Nusselt number, k is the thermal conductivity and D is the equivalent diameter of the oil gallery.

7. An apparatus for obtaining a convective heat transfer coefficient, characterized by It includes: A parameter acquisition module is configured to acquire first basic parameters of each oil duct in a transformer and second basic parameters of insulating oil in each oil duct, the first basic parameters including a radial diameter of the oil duct and an equivalent diameter of the oil duct, and the second basic parameters including a density of the insulating oil, a dynamic viscosity of the insulating oil, a specific heat capacity of the insulating oil, a thermal conductivity of the insulating oil, and a flow rate of the insulating oil; A target Nusselt number acquisition module is configured to calculate a target Nusselt number of insulating oil in each oil duct based on the first basic parameters and the second basic parameters. A convective heat transfer coefficient acquisition module is configured to obtain a convective heat transfer coefficient corresponding to the insulating oil in the oil duct based on the target Nusselt number for the insulating oil in each oil duct, and the convective heat transfer coefficient is used to reflect the heat exchange capacity of the insulating oil in each oil duct and the surface of the transformer winding. The target Nusselt number acquisition module is specifically configured to: Calculate a Reynolds number based on the flow rate of the insulating oil, the density of the insulating oil, the dynamic viscosity of the insulating oil, and the equivalent diameter of the oil duct; Calculate a Prandtl number based on the specific heat capacity of the insulating oil, the dynamic viscosity of the insulating oil, and the thermal conductivity of the insulating oil; Calculate a target Nusselt number of the insulating oil in the oil duct based on the Reynolds number, the Prandtl number, the radial diameter of the oil duct of the transformer, the equivalent diameter of the oil duct of the transformer, the dynamic viscosity of the insulating oil at the winding temperature, the dynamic viscosity of the insulating oil at the insulating oil flow field temperature, and a predetermined target coefficient.

8. An electronic device, comprising: The electronic device includes: One or more processors; A storage device for storing one or more programs, When the one or more programs are executed by the one or more processors, the one or more processors implement the method for acquiring a convective heat transfer coefficient as claimed in any one of claims 1-6.

9. A storage medium containing computer-executable instructions, wherein: The computer executable instructions, when executed by the computer processor, serve to perform the method of obtaining a convective heat transfer coefficient as claimed in any one of claims 1-6.

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