Motor power calculation method considering stirring state change of liquid solidified soil

Abstract

The invention relates to the technical field of numerical simulation, and particularly discloses a motor power calculation method considering stirring state change of liquid solidified soil, which comprises the following steps: firstly, determining liquid viscosity curves of the liquid solidified soil in different stirring states; constructing a particle motion control equation of the moving particle semi-implicit method MPS; calculating population density; discretizing the particle motion control equation, and calculating the pressure intensity of fluid particles under different viscosity conditions; an MPS model of liquid solidified soil stirring is established, the pressure intensity of liquid solidified soil particles acting on solid particles on stirring blades is monitored, and the acting force of the liquid solidified soil particles on the blade solid particles and the torque of a stirring shaft are calculated; working torque of the motor is obtained through a torque and force calculation formula, and finally motor power is obtained. According to the motor power calculation method considering the liquid solidified soil stirring state change, efficient matching of the mixing state of the fluid solidified soil and the stirring motor power change can be achieved.

Description

Technical Field

[0001] The invention relates to the technical field of numerical simulation, and in particular to a method for calculating motor power taking into account changes in the mixing state of liquid solidified soil. Background Art

[0002] Liquid solidified soil, also known as superfluid solidified soil, is a self-leveling, self-compacting, pouring engineering material that can be transported by a mud pump after a certain proportion of mineral-based gelling agent is directly added to the engineering waste mud and stirred by a mixer. When the mixer parameters remain unchanged, the stirring power and resistance of the solidified soil are mainly affected by the mixing state and interaction force of the mixture. Therefore, the effective determination of the law of stirring power and torque changes over time can achieve efficient matching of the mixing state of fluid solidified soil and the change of stirring motor power.

[0003] In the prior art, a real-time monitoring method can be used to mix liquid solidified soil, but this method has the problems of long time, high cost, non-closed mixing process and requirement for workers to have rich construction experience. Summary of the invention

[0004] The purpose of the present invention is to provide a method for calculating the motor power taking into account the changes in the mixing state of liquid solidified soil. By controlling the feeding time according to the stirring power in the stirring pump and using the MPS method to perform modeling simulation, efficient matching of the mixing state of fluid solidified soil and the changes in the stirring motor power can be achieved.

[0005] To achieve the above object, the present invention provides a method for calculating the motor power taking into account the change in the mixing state of liquid solidified soil, comprising the following steps: S1. Using a rotary viscometer to measure the viscosity of liquid solidified soil under different stirring states, and determine the liquid viscosity curve under different stirring states; S2, construct the particle motion control equations of the moving particle semi-implicit method MPS; S3, calculating the particle number density by introducing a weight function; S4, using the Laplace model and gradient model to discretize the particle motion control equations and calculate the pressure of fluid particles under different viscosity conditions; S5. Establish an MPS model for liquid solidified soil mixing, monitor the pressure of liquid solidified soil particles on solid particles on the mixing blades, and calculate the force of liquid solidified soil particles on the solid particles of the blades and the torque of the mixing shaft; S6. Calculate the working torque of the motor through the torque and force calculation formula, and finally calculate the motor power.

[0006] Preferably, in step S1, the specific process of determining the liquid viscosity curve under different stirring states is: According to the calculation formula of the viscosity value of the rotational viscometer, the torsion angle of the hairspring is measured and the dynamic viscosity of the liquid is calculated. The calculation formula of the dynamic viscosity value is: (1) in, is the torque, is the length of the inner cylinder, is the additional length caused by the cross-section effect, is the inner radius, is the inner radius of the outer cylinder, and ω is the angular velocity.

[0007] Preferably, in step S2, based on the mass conservation equation and the momentum conservation equation, the particle motion control equation of the moving particle semi-implicit method MPS is constructed, and the specific process is: According to the mass conservation equation and momentum conservation equation, for incompressible Newtonian fluid: (2) (3) in, is the density of the fluid, is the flow rate, For pressure, is the dynamic viscosity value measured above, is the acceleration due to gravity, is the surface tension.

[0008] Preferably, in step S3, the specific process of calculating the particle number density is: The positions of all particles are obtained. The particle number density will be affected by the neighboring particles within the effective radius and follow the weight function: (4) in, It is a particle and particles j The weight function between particles and particles j The distance between ,in, For particles j The position vector of For particles The position vector of is the effective radius; Based on the weights of all particles, they are summed up to get the particle number density.

[0009] Preferably, in step S4, the pressure exerted on the fluid particles under different viscosity conditions is calculated, and the specific process is as follows: Based on the MPS method, the control equations are discretized by using the Laplace model and the gradient model to obtain the pressure on the fluid particles; The Laplace model is: (5) in, For particles Any scalar, are the Laplace model coefficients, d is the space dimension, n 0 is the initial particle number density, It is a particle and particles j The weight function between ; The pressure gradient model is: (6) in, For pressure, For particles i Minimum pressure in adjacent areas.

[0010] Preferably, in step S5, the calculation to obtain the force of the liquid solidified soil particles on the solid particles of the blade and the torque of the stirring shaft is specifically performed as follows: The MPS model of liquid solidified soil mixing is established. According to step S4, the pressure of liquid solidified soil particles on the solid particles on the mixing blade is monitored, and the force on the mixing blade is obtained as follows: (7) in, P For pressure, A is the contact area between the particles and the stirring blades; The torque of the stirring shaft is: (8) Where r is the radius of the stirring blade.

[0011] Preferably, in step S6, the specific process of calculating and obtaining the motor power is: The output torque of the motor is the torque of the stirring shaft obtained in step S5 above, and the motor power calculated therefrom is: (9).

[0012] Therefore, the present invention adopts the above-mentioned method for calculating the motor power taking into account the change in the mixing state of liquid solidified soil, and the beneficial effects are as follows: (1) The mixing and reuse of liquid solidified soil in the present invention is a targeted construction process. By controlling the feeding time according to the stirring power in the stirring pump and using the MPS method for modeling and simulation, efficient matching of the mixing state of the fluid solidified soil and the power change of the stirring motor can be achieved.

[0013] (2) The present invention uses the MPS method to establish a simulation model of the motor stirring chamber. By monitoring the pressure of liquid solidified soil particles on the solid particles on the stirring blades, the motor power is calculated, thereby achieving the simulation calculation effect of different viscosities of liquid solidified soil slurry.

[0014] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a schematic diagram of the overall flow of an embodiment of a method for calculating motor power taking into account the change in the mixing state of liquid solidified soil according to the present invention; Figure 2 It is a liquid viscosity variation curve diagram of an embodiment of a method for calculating motor power taking into account the variation of the mixing state of liquid solidified soil according to the present invention; Figure 3 The invention discloses a liquid solidified soil mixing simulation model according to an embodiment of a method for calculating motor power taking into account the change of the liquid solidified soil mixing state.

[0016] Reference numerals 1. Chamber solid particles; 2. Solidified soil liquid particles; 3. Stirring shaft solid particles; 4. Stirring blade solid particles. DETAILED DESCRIPTION

[0017] The technical solution of the present invention is further described below through the accompanying drawings and embodiments.

[0018] Unless otherwise defined, the technical terms or scientific terms used in the present invention should be understood by people with ordinary skills in the field to which the present invention belongs. The words "first", "second" and similar words used in the present invention do not indicate any order, quantity or importance, but are only used to distinguish different components. "Include" or "comprise" and similar words mean that the elements or objects appearing before the word include the elements or objects listed after the word and their equivalents, without excluding other elements or objects. "Connect" or "connected" and similar words are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "Up", "down", "left", "right" and the like are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0019] like Figure 1 As shown in the figure, according to the liquid viscosity change curve measured by a rotational viscometer and based on the moving particle semi-implicit (MPS) method, a simulation model of the motor stirring chamber is established to simulate the stirring process of the fluidized solidified soil until the unloading is completed and stopped; by monitoring the pressure of the liquid solidified soil particles on the solid particles on the stirring blades, the motor power is calculated, and the physical parameters involved include: dynamic viscosity coefficient, pressure, torque and power, displacement, velocity and particle number density.

[0020] A method for calculating motor power considering the change of the mixing state of liquid solidified soil is used to match the corresponding motor power. The process includes the following steps: S1. Use a rotary viscometer to measure the viscosity of liquid solidified soil under different stirring conditions, such as Figure 2 As shown, the viscosity curve of the liquid under different stirring states is determined. The specific process is: According to the calculation formula of the viscosity value of the rotational viscometer, the torsion angle of the hairspring is measured and the dynamic viscosity of the liquid can be calculated. The calculation formula of the dynamic viscosity value is: (1) in, is the torque, is the length of the inner cylinder, is the additional length caused by the cross-section effect, is the inner radius, is the inner radius of the outer cylinder, and ω is the angular velocity.

[0021] S2. Based on the mass conservation equation and momentum conservation equation, the particle motion control equation of the moving particle semi-implicit method MPS is constructed. The liquid solidified soil part is composed of fluid particles, and the chamber wall and mixing blades are composed of solid particles. The specific process is as follows: In the MPS method, an implicit algorithm is used to calculate the pressure term, and an explicit algorithm is used to calculate the viscosity and external force terms. According to the mass conservation equation and momentum conservation equation, for an incompressible Newtonian fluid: (2) (3) in, is the density of the fluid, is the flow rate, For pressure, is the dynamic viscosity value measured above, is the acceleration due to gravity, is the surface tension.

[0022] Formula (3) can also be written as follows: ;

[0023] in The left side of the momentum conservation equation is the Lagrangian differential including the convection term, which is directly calculated by tracking the motion of the particle. The right side consists of the pressure gradient and the external force term. All terms expressed by differential operators should be replaced by the interaction of the particles.

[0024] Among them, the discrete form of the momentum conservation equation can be written as: (4) Where k is the current time step number, is the size of the time step.

[0025] The viscosity term in the formula is discretized into the following form: (5) in It is a particle At time step k The kinematic viscosity coefficient and dynamic viscosity coefficient are is a variable parameter; the Laplace term on the left can be interpreted as the difference between the velocity at a point and the average velocity of a small surrounding volume, which means that viscosity is the diffusion of momentum.

[0026] S3. Calculate the particle number density by introducing the weight function. The specific process is as follows: The initial positions of all particles are obtained. In the MPS method, the particle number density is affected by the neighboring particles within the effective radius and follows the weight function as follows: (6) in, It is a particle and particles j The weight function between particles and particles j The distance between , For particles j The position vector of For particles The position vector of is the effective radius. Based on the weights of all particles, the particle number density is obtained by summing them up.

[0027] When the positions of all particles are known, the particle number density can also be obtained: (7) S4. Use the Laplace model and gradient model to discretize the particle motion control equation and calculate the pressure of fluid particles under different viscosity conditions. The specific process is as follows: Based on the MPS method, the control equation is discretized by using the Laplace model and the gradient model to obtain the pressure on the fluid particles (the pressure of the liquid solidified soil particles on the solid particles on the mixing blades): (8) in, is the minimum pressure in the region adjacent to particle i: (9) The Laplace model is: (10) in, is an arbitrary scalar of particle i, are the Laplace model coefficients, d is the space dimension, n 0 is the initial particle number density, It is a particle i and particles j The weight function between ; Where: (11) The pressure gradient model is: (12) in, For pressure, For particles Minimum pressure in adjacent areas.

[0028] S5, such as Figure 3 As shown in the figure, the MPS model of liquid solidified soil mixing is established to monitor the pressure of liquid solidified soil particles on the solid particles on the mixing blades, and the force of liquid solidified soil particles on the solid particles of the blades and the torque of the mixing shaft are calculated. The specific process is as follows: The MPS model of liquid solidified soil mixing is established. According to step S4, the pressure of liquid solidified soil particles on the solid particles on the mixing blade is monitored, and the force on the mixing blade is obtained as follows: (13) in, P For pressure, A is the contact area between the particles and the stirring blades; The torque of the stirring shaft is: (14) Where r is the radius of the stirring blade.

[0029] S6. The working torque of the motor is obtained by the calculation formula of torque and force, and finally the motor power is obtained. The specific process is as follows: The output torque of the motor is the torque of the stirring shaft obtained in step S5. According to formula (13), the torque of the stirring blade at a distance of The particles are analyzed, that is: (15) in, h The height of the stirring blade.

[0030] After integration, we get: (16) in, x for The distance from the center axis, where M is the resultant moment on the particle, and its value is: (17) After simplifying equation (16), the torque of the motor can be obtained as follows: (18) in, r is the radius of the stirring blade, h is the height of the rotating blade.

[0031] The motor power calculated from this is: (19).

[0032] The particle positions are updated, and the program proceeds to the next time step loop until all particles in the model are calculated and the simulation is stopped.

[0033] In summary, one calculation step is divided into three processes: in the first process, the liquid viscosity change curve is measured; in the second process, the MPS model of liquid solidified soil mixing is established, and the pressure of liquid solidified soil particles on the solid particles on the mixing blades is calculated, and then the force of liquid solidified soil particles on the solid particles of the blades is obtained; in the third process, the torque of the motor is calculated, and finally the motor power is obtained.

[0034] Therefore, the present invention adopts the above-mentioned method for calculating the motor power taking into account the changes in the stirring state of liquid solidified soil. The stirring and reuse of liquid solidified soil is a targeted construction process. The feeding time is controlled according to the stirring power in the stirring pump, and the MPS method is used for modeling and simulation, thereby achieving efficient matching between the mixing state of fluid solidified soil and the changes in the stirring motor power.

[0035] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that they can still modify or replace the technical solution of the present invention with equivalents, and these modifications or equivalent replacements cannot cause the modified technical solution to deviate from the spirit and scope of the technical solution of the present invention.

Claims

1. A method for calculating motor power considering the change of mixing state of liquid solidified soil, characterized in that: The following steps are involved: S1. Using a rotary viscometer to measure the viscosity of liquid solidified soil under different stirring states, and determine the liquid viscosity curve under different stirring states; S2, construct the particle motion control equations of the moving particle semi-implicit method MPS; S3, calculating the particle number density by introducing a weight function; S4, using the Laplace model and gradient model to discretize the particle motion control equations and calculate the pressure of fluid particles under different viscosity conditions; S5. Establish an MPS model for liquid solidified soil mixing, monitor the pressure of liquid solidified soil particles on solid particles on the mixing blades, and calculate the force of liquid solidified soil particles on the solid particles of the blades and the torque of the mixing shaft; S6. Calculate the working torque of the motor through the torque and force calculation formula, and finally calculate the motor power.

2. A method for calculating motor power considering the change of the mixing state of liquid solidified soil according to claim 1, characterized in that: In step S1, the specific process of determining the liquid viscosity curve under different stirring states is as follows: According to the calculation formula of the viscosity value of the rotational viscometer, the torsion angle of the hairspring is measured and the dynamic viscosity of the liquid is calculated. The calculation formula of the dynamic viscosity value is: （1） in, is the torque, is the length of the inner cylinder, is the additional length caused by the section effect, is the inner radius, is the inner radius of the outer cylinder, and ω is the angular velocity.

3. A method for calculating motor power considering the change of the mixing state of liquid solidified soil according to claim 2, characterized in that: In step S2, based on the mass conservation equation and momentum conservation equation, the particle motion control equation of the moving particle semi-implicit method MPS is constructed. The specific process is as follows: According to the mass conservation equation and momentum conservation equation, for incompressible Newtonian fluid: （2） （3） in, is the density of the fluid, is the flow rate, For pressure, is the dynamic viscosity value measured above, is the acceleration due to gravity, is the surface tension.

4. A method for calculating the motor power considering the change of the mixing state of liquid solidified soil according to claim 3, characterized in that: In step S3, the specific process of calculating the particle number density is: The positions of all particles are obtained. The particle number density will be affected by the neighboring particles within the effective radius and follow the weight function: （4） in, It is a particle and particles j The weight function between particles and particles j The distance between ,in, For particles j The position vector of For particles i The position vector of is the effective radius; Based on the weights of all particles, they are summed up to get the particle number density.

5. A method for calculating motor power considering the change of the mixing state of liquid solidified soil according to claim 4, characterized in that: In step S4, the pressure exerted on the fluid particles under different viscosity conditions is calculated. The specific process is as follows: Based on the MPS method, the control equations are discretized by using the Laplace model and the pressure gradient model to obtain the pressure on the fluid particles; The Laplace model is: （5） in, For particles Any scalar, are the Laplace model coefficients, d is the space dimension, n 0 is the initial particle number density, It is a particle and particles j The weight function between ; The pressure gradient model is: （6） in, For pressure, For particles Minimum pressure in adjacent areas.

6. A method for calculating motor power considering the change of the mixing state of liquid solidified soil according to claim 5, characterized in that: In step S5, the calculation is performed to obtain the force of the liquid solidified soil particles on the solid particles of the blade and the torque of the stirring shaft. The specific process is: The MPS model of liquid solidified soil mixing is established. According to step S4, the pressure of liquid solidified soil particles on the solid particles on the mixing blade is monitored, and the force on the mixing blade is obtained as follows: （7） in, P For pressure, A is the contact area between the particles and the stirring blades; The torque of the stirring shaft is: （8） Where r is the radius of the stirring blade.

7. A method for calculating motor power considering the change of the mixing state of liquid solidified soil according to claim 6, characterized in that: In step S6, the specific process of calculating and obtaining the motor power is as follows: The output torque of the motor is the torque of the stirring shaft obtained in step S5 above, and the motor power calculated therefrom is: （9）。

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