Method for determining flow coefficient of excitation coil, temperature control method and vibration table

Abstract

The present invention discloses a method for determining the flow coefficient of an excitation coil, a temperature control method and a vibration table. The method for determining the flow coefficient comprises: selecting multiple local structures of the excitation coil to construct multiple simulation objects corresponding to the multiple local structures; simulating the coolant flow rate of the multiple simulation objects to obtain multiple simulation flow values ​​corresponding to the multiple simulation objects; substituting the multiple simulation flow values ​​into the flow formula of the excitation coil set in advance to calculate the flow coefficient of the excitation coil. By selecting multiple local structures of the excitation coil to construct simulation objects to obtain multiple simulation flow values, and combining theoretical calculations to obtain the flow coefficient of the excitation coil, the requirements for computing resources can be effectively reduced and computing efficiency can be greatly improved.

Description

Technical Field

[0001] The invention relates to the field of electric vibration tables, and in particular to a method for determining a flow coefficient of an excitation coil, a temperature control method and a vibration table. Background Art

[0002] As the key structure of the electric vibration table, the excitation coil generates an electromagnetic field in the air gap of the vibration table after power is turned on, providing the necessary magnetic excitation for the normal operation of the vibration table. Since the magnetic field strength required by the large-tonnage electric vibration table is relatively large, the current in the excitation coil is usually also large, and the large current will cause the coil to heat up seriously, and there are strict requirements on the heat dissipation capacity of the coil. Most of the water cooling methods are used on the market to ensure the normal operation of the excitation coil, such as the prior art CN201152804Y. When designing the vibration table, it is particularly important to perform necessary heat dissipation performance debugging on the water-cooled excitation coil to ensure the normal operation of the vibration table. The method of using empirical values ​​to debug the heat dissipation parameters has low work efficiency and is difficult to ensure the accuracy of temperature control.

[0003] The inventor found that in the process of temperature control of the water-cooled excitation coil of the vibration table, the temperature can be accurately controlled by calculating and controlling the accurate coolant flow rate, but in the process of calculating the coolant flow rate, the flow coefficient of the excitation coil needs to be determined in order to calculate the coolant flow rate and achieve heat dissipation control. Due to the various winding methods of the excitation coil, different winding methods correspond to different flow coefficients. If the finite volume method is used to simulate the coolant flow of the entire excitation coil, a large number of grids need to be divided to accurately simulate the flow. The calculated flow coefficient has a high accuracy, but the requirements for computing resources are very high, and the calculation process is complicated and inefficient. Summary of the invention

[0004] Therefore, the present invention aims to solve the problem that the flow coefficient is calculated by simulating the coolant flow of the entire excitation coil in the prior art, which has high computing resource requirements, complex process and low efficiency. A method for determining the flow coefficient of the excitation coil, a temperature control method and a vibration table are provided.

[0005] An embodiment of the present invention provides a method for determining a flow coefficient of an excitation coil, wherein the excitation coil is wound by a wire having a hollow pipe, and a coolant flows in the hollow pipe; the method comprises the following steps:

[0006] Selecting multiple local structures of the excitation coil, and constructing multiple simulation objects corresponding to the multiple local structures one by one;

[0007] Performing simulation of coolant flow rates on the multiple simulation objects respectively to obtain multiple simulation flow rates corresponding to the multiple simulation objects one by one;

[0008] The multiple simulated flow values ​​are respectively substituted into the pre-set flow formula of the excitation coil to calculate the flow coefficient of the excitation coil.

[0009] Optionally, the step of substituting the plurality of simulated flow values ​​into a preset flow formula of the excitation coil to calculate the flow coefficient of the excitation coil comprises:

[0010] Substituting the plurality of simulated flow values ​​into the flow formula respectively to obtain a plurality of calculation equations, each calculation equation being used to represent a functional relationship between the flow rate of the coolant in a corresponding local structure and the flow coefficient of the local structure, and the calculation equation containing parameters for calculating the flow coefficient;

[0011] Combining the plurality of calculation equations to solve and obtain the value of the parameter;

[0012] The flow coefficient of the excitation coil is obtained by calculation using the parameters.

[0013] Optionally, the selecting of multiple local structures of the excitation coil to construct multiple simulation objects corresponding to the multiple local structures comprises:

[0014] Determine the number of parameters used to calculate the discharge coefficient;

[0015] A plurality of local structures equal to the number of the parameters are selected to construct a plurality of simulation objects equal to the number of the parameters.

[0016] Optionally, the excitation coil is a disc winding structure, and the parameters include a local resistance coefficient and an along-the-path resistance coefficient.

[0017] Optionally, the selecting a plurality of local structures equal to the number of the parameters to construct a plurality of simulation objects equal to the number of the parameters comprises:

[0018] Select two windings at the middle position of the disc winding of the excitation coil as two simulation objects;

[0019] The coolant flow rate is simulated for each of the plurality of simulation objects to obtain a plurality of simulation flow rate values ​​corresponding to the plurality of simulation objects, including:

[0020] The coolant flow rate is simulated for the two simulation objects, and two simulation flow rate values ​​Q1 and Q2 are obtained accordingly.

[0021] Optionally, the multiple simulated flow values ​​are substituted into the flow formula to obtain multiple calculation equations, including:

[0022] The lengths of the two windings selected in the disc winding and the hydraulic diameter of the water-passing section are obtained, and the simulated flow values ​​Q1 and Q2 are substituted into the flow formula of the excitation coil. The flow formula includes:

[0023] Formula 1: μ = 1 / (1 + ε + γ k / d) 0.5

[0024] Formula 2:

[0025] Among them, ε=nζ, n is the number of turns of the disc winding, ε is the local resistance coefficient of the disc winding, among which, ζ is the local resistance coefficient of each turn of the disc winding, γ is the resistance coefficient along the way, k is the length of the disc winding, d is the hydraulic diameter of the water-passing section; S is the cross-sectional area of ​​the water-passing section, H=P / ρg is the equivalent head height of the water flow pressure at the inlet, among which, P is the pressure at the inlet, g is the acceleration of gravity, ρ is the density of the coolant, μ is the flow coefficient of the excitation coil, and Q is the flow of the excitation coil;

[0026] The combining of the plurality of calculation equations to solve the parameter values ​​comprises: calculating the local resistance coefficient ζ and the along-the-line resistance coefficient γ of each winding in the stacked winding;

[0027] The method of calculating the flow coefficient of the excitation coil by using the parameters includes: substituting the above result value into Formula 1 to obtain the flow coefficient of the excitation coil.

[0028] An embodiment of the present invention provides a method for controlling the temperature of an excitation coil, wherein the flow coefficient of the excitation coil is obtained by any of the above flow coefficient determination methods, and the method for controlling the temperature of the excitation coil comprises the following steps:

[0029] Determining a temperature rise ΔT of the coolant based on the target temperature of the excitation coil;

[0030] Obtaining the heating power W of the excitation coil during operation;

[0031] According to the temperature rise ΔT of the coolant and the heat generation power W of the excitation coil during operation, a target coolant flow rate for the excitation coil to reach the target temperature during operation is obtained;

[0032] A target control amount for the coolant is determined based on the target coolant flow rate and the flow coefficient of the excitation coil to perform temperature control on the excitation coil, wherein the target control amount is used to control the excitation coil to reach the target temperature under the action of the target coolant flow rate.

[0033] Optionally, the step of obtaining a target coolant flow rate for the excitation coil to reach the target temperature when the excitation coil is working according to the temperature rise ΔT of the coolant and the heat generation power W of the excitation coil during operation comprises:

[0034] When the excitation coil is working, the formula for the temperature rise ΔT of the coolant in it is:

[0035] ΔT=W / (CQ ALL )

[0036] Where, C is the specific heat capacity of the coolant;

[0037] According to the above coolant temperature rise ΔT formula, the target coolant flow rate Q is obtained. ALL .

[0038] Optionally, determining a target control amount of the coolant based on the target coolant flow rate and a flow coefficient of the excitation coil includes:

[0039] The target coolant flow rate Q ALL And the flow coefficient μ of the excitation coil is substituted into the following formula:

[0040]

[0041] Among them, S is the cross-sectional area of ​​the water flow section, g is the gravitational acceleration, H is the equivalent head height of the water flow pressure at the inlet, μ is the flow coefficient of the excitation coil, and Q is the flow rate of the excitation coil; thus, the equivalent head height H of the water flow pressure at the inlet is obtained;

[0042] Substitute the equivalent head height H of the water flow pressure at the inlet into the formula H=P / ρg, where P is the pressure at the inlet, g is the acceleration of gravity, and ρ is the density of the coolant; obtain the pressure P at the inlet, and use the obtained pressure P at the inlet as the target control quantity.

[0043] An embodiment of the present invention provides a vibration table, comprising an excitation coil, wherein the temperature of the excitation coil is controlled by using any of the above excitation coil temperature control methods.

[0044] The technical solution of the present invention has the following advantages:

[0045] 1. The method for determining the flow coefficient of an excitation coil provided by the present invention obtains multiple simulated flow values ​​by selecting multiple local structures of the excitation coil to construct a simulation object, and obtains the flow coefficient of the excitation coil in combination with theoretical calculations, thereby avoiding direct simulation of the entire excitation coil with a large aspect ratio. Therefore, it can effectively reduce the computing resource requirements and greatly improve the computing efficiency.

[0046] 2. The excitation coil temperature control method provided by the present invention can accurately control the temperature of the excitation coil by controlling the pressure P at the inlet of the excitation coil coolant, so that the excitation coil operates at the target temperature, ensuring stable and efficient operation of the excitation coil.

[0047] 3. The vibration table provided by the present invention adopts the excitation coil temperature control method to control the temperature, and can accurately control the temperature of the excitation coil of the vibration table, so that the excitation coil works at the target temperature, ensuring that the excitation coil works stably and efficiently, thereby improving the stability and service life of the vibration table. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0049] Figure 1 It is a flowchart of a specific example of the method for determining the flow coefficient of the excitation coil in Embodiment 1 of the present invention;

[0050] Figure 2 It is a schematic diagram of a partial winding structure of the excitation coil winding in Embodiment 1 of the present invention;

[0051] Figure 3 is a cross-sectional view of the excitation coil in Example 1 of the present invention;

[0052] Figure 4 This is a schematic diagram of the unfolding structure of the double-disc laminated winding in a preferred embodiment of Embodiment 1 of the present invention;

[0053] Figure 5 This is a flowchart of a specific example of the excitation coil temperature control method in Embodiment 2 of the present invention. DETAILED DESCRIPTION

[0054] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0055] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0056] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, it can also be the internal connection of two components, it can be a wireless connection, or it can be a wired connection. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0057] In addition, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0058] Example 1

[0059] This embodiment provides a method for determining the flow coefficient of an excitation coil. Figure 2-4 As shown, the excitation coil is wound by a wire having a hollow pipe, and a coolant flows in the hollow pipe; Figure 1 As shown, the method may include the following steps:

[0060] S1: Select multiple local structures of the excitation coil, and construct multiple simulation objects corresponding to the multiple local structures. The multiple local structures can be formed by regularly dividing the excitation coil according to the structural characteristics of the excitation coil. For example, according to the structure of the excitation coil, a single-turn or multi-turn winding is used as a local structure. A single local structure only occupies one tenth of the total length of the excitation coil, or a smaller proportion. The simulation object is a digital model of the local structure constructed by simulation software, and the digital model can reflect the structural characteristics and material characteristics of the local structure in the form of data.

[0061] S2: Simulate the coolant flow rate of the multiple simulation objects respectively to obtain multiple simulation flow values ​​corresponding to the multiple simulation objects; the simulation can be performed using simulation software or finite volume method. The simulation flow value is a data value calculated by a computer simulation program using simulation software to simulate the simulation object.

[0062] S3: Substitute the multiple simulated flow values ​​into the pre-set flow formula of the excitation coil respectively to calculate the flow coefficient of the excitation coil; the pre-set flow formula of the excitation coil is used to express the functional relationship between the flow rate of the coolant in the local structure and the flow coefficient of the local structure.

[0063] Since the excitation coil is a structure with a large aspect ratio, its cross-sectional size is in the millimeter level, while its length can reach hundreds of meters. If the finite volume method is used alone to simulate the flow of coolant in the excitation coil, a large number of grids need to be divided to accurately simulate the flow. The amount of calculation is extremely large and the requirements for computing resources are very high, making such simulation not very easy to implement.

[0064] According to an embodiment of the present invention, a plurality of local structures of the excitation coil are selected to construct a simulation object to obtain a plurality of simulated flow values, and the flow coefficient of the excitation coil is obtained in combination with theoretical calculation, thereby avoiding direct simulation of the entire excitation coil with a large aspect ratio. Therefore, the computing resource requirements can be effectively reduced and the computing efficiency can be greatly improved.

[0065] Preferably, step S3 may include the following steps:

[0066] S31: Substitute the multiple simulated flow values ​​into the flow formula respectively to obtain multiple calculation equations, each calculation equation is used to represent the functional relationship between the flow rate of the coolant in the corresponding local structure and the flow coefficient of the local structure, and the calculation equation contains parameters for calculating the flow coefficient; for the excitation coil formed by winding a wire with a hollow pipe, the flow coefficient is related to multiple factors such as its structure and material, and the multiple factors are manifested in that the flow coefficient is determined by multiple parameters, and the multiple parameters and the flow coefficient form a specific functional relationship.

[0067] S32: combining the plurality of calculation equations to obtain the value of the parameter by solving them;

[0068] S33: Calculate the flow coefficient of the excitation coil using the parameters.

[0069] Compared with the method of repeatedly debugging the heat dissipation parameters using empirical values, the above-mentioned theoretical calculation method improves the debugging efficiency and also improves the accuracy of the flow coefficient of the excitation coil to a great extent, thereby ensuring the accuracy of the temperature control of the excitation coil.

[0070] Preferably, step S1 may include the following steps:

[0071] S11: determining the number of parameters used to calculate the flow coefficient;

[0072] S12: selecting a plurality of local structures equal to the number of the parameters, and constructing a plurality of simulation objects equal to the number of the parameters.

[0073] For an excitation coil wound by a wire having a hollow pipe, the flow coefficient is related to multiple factors such as its structure and material, and the multiple factors are manifested in that the flow coefficient is determined by multiple parameters, and a specific functional relationship is formed between the multiple parameters and the flow coefficient. A plurality of simulation objects equal to the number of the parameters are constructed to construct a multivariate equation group, and the multiple parameters are obtained by solving the multivariate equation group, and then the flow coefficient of the excitation coil is calculated based on the specific functional relationship between the multiple parameters and the flow coefficient.

[0074] By constructing local structure simulation models with a number equal to the number of the parameters, it can be ensured that the multiple parameters can be calculated without increasing the amount of additional calculations, thereby further improving the calculation efficiency of the method for determining the flow coefficient of the excitation coil.

[0075] Preferably, the parameters may include a local resistance coefficient and an along-the-path resistance coefficient, and the excitation coil is a disc winding structure.

[0076] like Figure 2 As shown, the excitation coil is a disc winding structure. In this case, in order to obtain the flow rate of the excitation coil, it is only necessary to determine the two unknowns, the local resistance coefficient ε and the resistance coefficient γ along the way. The local resistance coefficient ε is related to the bending angle of the coil and the diameter of the coil, while the resistance coefficient γ along the way is related to the water-passing cross-sectional area of ​​the elbow and the elbow material.

[0077] Preferably, step S12 may include the following steps:

[0078] S121: selecting two windings at the middle position of the disc winding of the excitation coil as two simulation objects;

[0079] The process of using simulation to simulate the coolant flow in the annular hollow pipe should be as close as possible to the actual flow state of the coolant in the disc winding in the excitation coil, so that the local resistance coefficient ζ and the along-the-path resistance coefficient γ of the disc winding in the excitation coil can be solved relatively accurately. Therefore, in the two bend flow simulation processes, the cross-sectional area of ​​the bend needs to be consistent with the cross-sectional area of ​​the excitation coil, and the diameter of the bend is the middle size of the disc winding. According to the above two requirements, select Figure 2 The two windings numbered 3 and 4 (located in the middle of the disc winding) are used as the objects of simulation. The flow process of the coolant in these two windings is simulated, and the flow rate in two different flow processes can be finally obtained. Substituting into the above-mentioned binary linear equation, the local resistance coefficient ζ and the resistance coefficient along the path of the single winding in the disc winding are further obtained. It should be noted here that since the two windings as the objects of simulation are made of the same material and have similar structures, they can be approximated to have the same local resistance coefficient ζ and resistance coefficient along the path γ.

[0080] Optionally, when the disc winding has an odd number of turns, the middle turn and its adjacent turn can be selected as the objects of simulation; in some cases, when the calculation accuracy of the excitation coil flow coefficient is not high, any two windings in the disc winding can also be selected as the objects of simulation.

[0081] Preferably, step S2 may include the following steps:

[0082] S21: Simulating the coolant flow rate of the two simulation objects, and obtaining two simulation flow rate values ​​Q1 and Q2 accordingly.

[0083] With the help of the finite volume method, the flow of coolant in different annular bends was simulated twice, and the final flow rates Q1 and Q2 were obtained respectively. The two unknowns ε and γ can be further obtained, and finally the calculation formula for the coolant flow in the excitation coil was determined.

[0084] Preferably, step S31 may include the following steps:

[0085] S311: Obtain the length of the two selected windings in the disc winding and the hydraulic diameter of the water-passing section, and substitute the simulated flow values ​​Q1 and Q2 into the flow formula of the excitation coil. The flow formula includes:

[0086] Formula 1: μ = 1 / (1 + ε + γ k / d) 0.5

[0087] Formula 2:

[0088] Among them, ε=nζ, n is the number of turns of the disc winding, ε is the local resistance coefficient of the disc winding, ζ is the local resistance coefficient of each turn of the disc winding, γ is the resistance coefficient along the way, k is the length of the disc winding, d is the hydraulic diameter of the water-passing section; S is the cross-sectional area of ​​the water-passing section, H=P / ρg is the equivalent head height of the water flow pressure at the inlet, where P is the pressure at the inlet, g is the acceleration of gravity, ρ is the density of the coolant, μ is the flow coefficient of the excitation coil, and Q is the flow of the excitation coil; such as Figure 3 The cross-sectional area of ​​the water-passing section S = (a-2t) (b-2t), and the hydraulic diameter of the water-passing section d = 4 (a-2t) (b-2t) / [2 ((a-2t) + (b-2t))];

[0089] S312: The combining of the plurality of calculation equations to solve the parameter values ​​includes: calculating the local resistance coefficient ζ and the longitudinal resistance coefficient γ of each winding in the stacked winding;

[0090] Preferably, step S33 may include the following steps:

[0091] S331: Substitute the above result value into Formula 1 to obtain the flow coefficient of the excitation coil.

[0092] Since the two simulated coolant flow pipes are selected for the coil in the middle position of the disc winding, the local resistance coefficient ζ of the single-turn winding obtained through these two simulations can be approximated as the average value of the local resistance coefficient of each turn of the disc winding. Therefore, the local resistance coefficient of the entire disc winding can be expressed as: ε=nζ; where n is the number of turns of the disc winding.

[0093] As an alternative embodiment, the coolant may be selected as cooling water; or other existing liquids or gases may be selected as the coolant based on the requirements of cooling performance, taking into account factors such as safety and cost.

[0094] As a preferred embodiment, as the excitation coil of the large-tonnage vibration table, its basic composition structure is a single double-disc laminated winding, which is formed by a hollow copper wire wound from the middle to the two ends in a forward spiral and a reverse spiral. The specific structure is as follows Figure 4 As shown. Such multiple (usually more than 10) double-disc laminated windings are longitudinally arranged and combined together to form an excitation coil. The water outlets (12, 22) and water inlets (11, 12) of all double-disc laminated windings in the coil are connected in parallel by water pipes, and the water outlet ports (12) and water inlet ports (21) of two adjacent double-disc laminated windings are welded together by electric welding, so that the electricity in the excitation coil can be ensured to be connected in series.

[0095] Example 2

[0096] This embodiment provides a method for controlling the temperature of an excitation coil, wherein the flow coefficient of the excitation coil is obtained by any of the flow coefficient determination methods described in Embodiment 1, such as Figure 5 As shown, the excitation coil temperature control method may include the following steps:

[0097] S10: determining a temperature rise ΔT of the coolant based on the target temperature of the excitation coil;

[0098] S20: Obtaining the heating power W of the excitation coil during operation;

[0099] Specifically, a constant voltage U is passed through the excitation coil, and the resistance value R of the entire excitation coil can be expressed as: R = λL / Ф; where λ is the resistivity of the material used for the excitation coil; L is the unfolded length of the excitation coil; Ф = ab-(a-2t)(b-2t) is the conductive cross-sectional area of ​​the excitation coil. Correspondingly, the current I on the excitation coil can be expressed as: I = U / R; then the heating power W in the excitation coil is: W = UI.

[0100] S30: Obtaining a target coolant flow rate for the excitation coil to reach the target temperature when the excitation coil is working according to the coolant temperature rise ΔT and the heat generation power W of the excitation coil;

[0101] After the excitation coil is working stably, the excitation coil and the coolant inside it will reach thermal equilibrium, and the coolant and the excitation coil have good heat conduction. It can be determined that the temperature of the coolant at this time is the temperature of the excitation coil.

[0102] S40: Determine a target control amount for the coolant based on the target coolant flow rate and the flow coefficient of the excitation coil to perform temperature control on the excitation coil, wherein the target control amount is used to control the excitation coil to reach the target temperature under the action of the target coolant flow rate.

[0103] Preferably, step S30 may include the following steps:

[0104] When the excitation coil is working, the temperature rise ΔT of the coolant in it is: ΔT=W / (CQ ALL ).

[0105] Where, C is the specific heat capacity of the coolant;

[0106] According to the above coolant temperature rise ΔT formula, the target coolant flow rate Q is obtained. ALL .

[0107] Preferably, step S40 may include the following steps:

[0108] S401: The target coolant flow rate QALL And the flow coefficient μ of the excitation coil is substituted into the following formula:

[0109]

[0110] Wherein, S is the cross-sectional area of ​​the water flow section, g is the gravitational acceleration, H is the equivalent water head height of the water flow pressure at the inlet; thereby obtaining the equivalent water head height H of the water flow pressure at the inlet, μ is the flow coefficient of the excitation coil, and Q is the flow rate of the excitation coil;

[0111] S402: Substitute the equivalent head height H of the water flow pressure at the inlet into the formula H=P / ρg, where P is the pressure at the inlet, g is the acceleration of gravity, and ρ is the density of the coolant; obtain the pressure P at the inlet, and use the obtained pressure P at the inlet as the target control quantity.

[0112] According to the above embodiment, the temperature of the excitation coil can be accurately controlled by controlling the pressure P at the inlet of the excitation coil coolant, so that the excitation coil operates at the target temperature, ensuring that the excitation coil operates stably and efficiently.

[0113] Example 3

[0114] This embodiment provides a vibration table, including an excitation coil, wherein the temperature of the excitation coil is controlled by any of the excitation coil temperature control methods described in Embodiment 2.

[0115] The vibration table adopts the excitation coil temperature control method to control the temperature, and can accurately control the temperature of the excitation coil of the vibration table, so that the excitation coil works at the target temperature, ensuring that the excitation coil works stably and efficiently, thereby improving the stability and service life of the vibration table.

[0116] Obviously, the above embodiments are merely examples for the purpose of clear explanation, and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived therefrom are still within the scope of protection of the invention.

Claims

1. A method for determining a flow coefficient of an excitation coil, wherein the excitation coil is wound by a wire having a hollow pipe, and a coolant flows in the hollow pipe; characterized in that: The method comprises the following steps: Selecting multiple local structures of the excitation coil, and constructing multiple simulation objects corresponding to the multiple local structures one by one; Performing simulation of coolant flow rates on the multiple simulation objects respectively to obtain multiple simulation flow rates corresponding to the multiple simulation objects one by one; Substituting the multiple simulated flow values ​​into the pre-set flow formula of the excitation coil respectively, and calculating the flow coefficient of the excitation coil; Substituting the multiple simulated flow values ​​into a preset flow formula of the excitation coil to calculate the flow coefficient of the excitation coil includes: Substituting the plurality of simulated flow values ​​into the flow formula respectively to obtain a plurality of calculation equations, each calculation equation being used to represent a functional relationship between the flow rate of the coolant in a corresponding local structure and the flow coefficient of the local structure, and the calculation equation containing parameters for calculating the flow coefficient; Combining the plurality of calculation equations to solve and obtain the value of the parameter; The flow coefficient of the excitation coil is obtained by calculation using the parameters.

2. The method for determining the flow coefficient of the excitation coil according to claim 1, characterized in that: The selecting of multiple local structures of the excitation coil to construct multiple simulation objects corresponding to the multiple local structures comprises: Determine the number of parameters used to calculate the discharge coefficient; A plurality of local structures equal to the number of the parameters are selected to construct a plurality of simulation objects equal to the number of the parameters.

3. The method for determining the flow coefficient of the excitation coil according to claim 2, characterized in that: The excitation coil is a disc winding structure, and the parameters include a local resistance coefficient and an along-the-path resistance coefficient.

4. The method for determining the flow coefficient of the excitation coil according to claim 3, characterized in that: The selecting of a plurality of local structures equal to the number of the parameters to construct a plurality of simulation objects equal to the number of the parameters comprises: Select two windings at the middle position of the disc winding of the excitation coil as two simulation objects; The coolant flow rate is simulated for each of the plurality of simulation objects to obtain a plurality of simulation flow rate values ​​corresponding to the plurality of simulation objects, including: The coolant flow rate is simulated for the two simulation objects, and two simulation flow rate values ​​Q1 and Q2 are obtained accordingly.

5. The method for determining the flow coefficient of the excitation coil according to claim 4, characterized in that: Substituting the multiple simulated flow values ​​into the flow formula respectively, a plurality of calculation equations are obtained, including: The lengths of the two windings selected in the disc winding and the hydraulic diameter of the water-passing section are obtained, and the simulated flow values ​​Q1 and Q2 are substituted into the flow formula of the excitation coil. The flow formula includes: Formula 1: μ=1 / (1+ε+γk / d) 0.5 Formula 2: Among them, ε=nζ, n is the number of turns of the disc winding, ε is the local resistance coefficient of the disc winding, among which, ζ is the local resistance coefficient of each turn of the disc winding, γ is the resistance coefficient along the way, k is the length of the disc winding, d is the hydraulic diameter of the water-passing section; S is the cross-sectional area of ​​the water-passing section, H=P / ρg is the equivalent head height of the water flow pressure at the inlet, among which, P is the pressure at the inlet, g is the acceleration of gravity, ρ is the density of the coolant, μ is the flow coefficient of the excitation coil, and Q is the flow of the excitation coil; The combining of the plurality of calculation equations to solve the parameter values ​​comprises: calculating the local resistance coefficient ζ and the along-the-line resistance coefficient γ of each winding in the stacked winding; The method of calculating the flow coefficient of the excitation coil by using the parameters includes: substituting the above result value into Formula 1 to obtain the flow coefficient of the excitation coil.

6. A method for controlling the temperature of an excitation coil, characterized in that: The flow coefficient of the excitation coil is obtained by the flow coefficient determination method according to any one of claims 1 to 5, and the excitation coil temperature control method comprises the following steps: Determining a temperature rise ΔT of the coolant based on the target temperature of the excitation coil; Obtaining the heating power W of the excitation coil during operation; According to the temperature rise ΔT of the coolant and the heat generation power W of the excitation coil during operation, a target coolant flow rate for the excitation coil to reach the target temperature during operation is obtained; A target control amount for the coolant is determined based on the target coolant flow rate and the flow coefficient of the excitation coil to perform temperature control on the excitation coil, wherein the target control amount is used to control the excitation coil to reach the target temperature under the action of the target coolant flow rate.

7. The method for controlling the temperature of the excitation coil according to claim 6, characterized in that: The method of obtaining a target coolant flow rate for the excitation coil to reach the target temperature when the excitation coil is working according to the temperature rise ΔT of the coolant and the heat generation power W of the excitation coil during operation comprises: When the excitation coil is working, the formula for the temperature rise ΔT of the coolant in it is: ΔT=W / (CQ ALL ) Where, C is the specific heat capacity of the coolant; According to the above coolant temperature rise ΔT formula, the target coolant flow rate Q is obtained. ALL .

8. The method for controlling the temperature of the excitation coil according to claim 6, characterized in that: The step of determining a target control amount of the coolant based on the target coolant flow rate and the flow coefficient of the excitation coil includes: The target coolant flow rate Q ALL And the flow coefficient μ of the excitation coil is substituted into the following formula: Among them, S is the cross-sectional area of ​​the water flow section, g is the gravitational acceleration, and H is the equivalent head height of the water flow pressure at the inlet; thus, the equivalent head height H of the water flow pressure at the inlet is obtained; Substitute the equivalent head height H of the water flow pressure at the inlet into the formula H=P / ρg, where P is the pressure at the inlet, g is the acceleration of gravity, and ρ is the density of the coolant; obtain the pressure P at the inlet, and use the obtained pressure P at the inlet as the target control quantity, μ is the flow coefficient of the excitation coil, and Q is the flow of the excitation coil.

9. A vibration table, comprising an excitation coil, characterized in that: The temperature of the excitation coil is controlled by the excitation coil temperature control method as described in any one of claims 6 to 8.

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