Method for establishing pneumatic conveying model, control method and system and electronic equipment

Abstract

The invention provides a method for establishing a pneumatic conveying model, a control method and system and electronic equipment. The method comprises the following steps that S1, at least two sets of fitting data are obtained, and each set of fitting data comprises the transition speed in a conveying pipeline and the critical blocking gas speed; s2, fitting data are substituted into a pneumatic conveying model; and S3, fitting to obtain fitting coefficients a and b, and training to obtain the pneumatic conveying model. According to the control method, the critical blocking gas speed in the conveying pipeline can be accurately calculated; and the air speed in the pipeline can be regulated and controlled in real time, so that the conveying air speed in the pipeline is always larger than the critical blocking air speed, and the situation that materials are blocked in the pneumatic conveying process is effectively avoided. The method has important guiding significance especially for design and safe and efficient operation of pneumatic conveying of biomass powder in industrial application.

Description

Technical Field

[0001] The present invention relates to the technical field of pneumatic conveying of biomass powder materials, and particularly relates to a method for establishing a pneumatic conveying model, a control method, a system and an electronic device. Background Art

[0002] As a renewable energy source, biomass has broad application prospects under the background of the "dual carbon goal" and the transformation of the energy supply structure. By realizing the safe, stable, continuous and efficient pneumatic conveying process of biomass powder, it can provide important reference for the design of biomass gasification devices in industry, thus promoting the efficient utilization of biomass energy.

[0003] In practical applications, in order to reduce the wear of pipelines and particles and considering the system economy, it is more desirable to carry out the pneumatic conveying of biomass powder at a lower gas velocity. However, when the gas velocity is reduced to a certain critical value, the pipeline will become blocked. In industrial applications, once the pneumatic conveying system of biomass powder becomes blocked, it will seriously affect the downstream process flow and even cause significant economic losses.

[0004] The minimum conveying gas velocity corresponding to the pipeline blockage is defined as the critical blockage gas velocity. At present, the research on the identification of the critical blockage state at home and abroad mainly stays in the empirical model stage. The most studied direction is the empirical fitting based on the gas velocity and solid-gas ratio at the pipeline inlet. The advantage of this method is that the calculation process is relatively simple, but it has the limitation of only being applicable to specific systems and materials. Once the system or material changes, the calculation accuracy of this method will be greatly reduced.

[0005] Once the conveying gas velocity is less than the critical blockage gas velocity, the pipeline will become blocked. At present, there is a lack of a control system and a control method that can adjust the pipeline gas velocity in real time to keep it always greater than the critical blockage gas velocity. Summary of the Invention

[0006] In order to overcome the defect that the prior art is prone to blockage problems when pneumatically conveying materials, the present invention provides a method for establishing a pneumatic conveying model, a control method, a system and an electronic device; this control method can accurately calculate the critical blockage gas velocity in the conveying pipeline; based on this, it can adjust the gas velocity in the pipeline in real time to make the conveying gas velocity in the pipeline always greater than the critical blockage gas velocity, effectively avoiding the situation of material blockage during the pneumatic conveying process. The present invention is particularly of great guiding significance for the design and safe and efficient operation of pneumatic conveying of biomass powder in industrial applications.

[0007] The present invention provides a method for establishing a pneumatic conveying model, which includes the following steps:

[0008] S1. Obtain at least two groups of fitting data, and each group of the fitting data includes the transition velocity U in the conveying pipelineg,s and the transition velocity U g,s corresponding critical choking velocity U g,cb ;

[0009] The conveying pipeline includes a horizontal section, a bent section or a vertical section;

[0010] At the horizontal section, the calculation model of the transition velocity U g,s ’ is as Equation I:

[0011]

[0012] At the vertical section, the calculation model of the transition velocity U g,s ” is as Equation II:

[0013]

[0014] At the bent section, the calculation model of the transition velocity U g,s ”’ is as Equation III:

[0015]

[0016] wherein, d V is the volume average particle size of the conveyed particles, m; ρ p is the density of the conveyed particles, kg / m 3 ; g is the acceleration of gravity, m / s 2 ; ρ g is the density of the conveying gas, kg / m 3 ; μ g is the dynamic viscosity of the conveying gas, Pa·s; D is the inner diameter of the conveying pipeline, m; C D is the drag coefficient;

[0017] S2. Substitute the fitting data into the pneumatic conveying model, and the pneumatic conveying model is as Equation IV:

[0018]

[0019] wherein, U g,cb is the critical choking velocity in the conveying pipeline, m / s; U g,s is the transition velocity in the conveying pipeline, m / s; m s is the mass flux of the conveyed particles, kg / (m 2 ·s); a and b are fitting coefficients respectively;

[0020] S3. Fit to obtain the fitting coefficients a and b, and train to obtain the pneumatic conveying model.

[0021] In the present invention, the fitting data requires the transition velocity U within the same conveying section g,s and the critical choking gas velocity U g,cb ; for example, obtaining fitting data in at least two horizontal sections, or obtaining fitting data in at least two bent sections, or obtaining fitting data in at least two vertical sections.

[0022] In some embodiments, the critical choking gas velocity U g,cb is obtained through experimental testing. The method of the experimental testing is as follows: keeping m s constant, gradually reducing U g until choking occurs. The U at the time of choking g is the U g,cb ; specifically, it includes the following steps: controlling the conveying pressure difference to be constant and keeping the mass flux of the conveyed particles constant; then gradually reducing the velocity of the conveying gas until the conveying pipeline becomes blocked; then, based on the total intake air volume, pipeline temperature, and pressure at the time of choking, the critical choking gas velocity U g,cb can be calculated.

[0023] In the present invention, the transition velocity U g,s represents the minimum conveying gas velocity required to keep the conveyed particles suspended; essentially, it is the conveying gas velocity U g corresponding to the state where the conveyed particles are in force balance in the vertical direction. U g is already included in the pneumatic conveying model. It only needs to substitute the various forces acting on the conveyed particles into the pneumatic conveying model.

[0024] In step S2 of the present invention, the pneumatic conveying model can also be referred to as the dynamic equation of the conveyed particles.

[0025] In the present invention, the force acting on a single particle during the pneumatic conveying process in the horizontal section is as follows: the particle moves horizontally along the x direction; in the y direction, the particle is subjected to the gravitational force F G , the buoyancy force F B and the lift force F L . F G comes from the gravitational field around the particle and is directed vertically downward. It is the main force causing the particle to settle; F B comes from the static pressure difference on the surface of the particle and is directed vertically upward. Its magnitude is equal to the gravity of the gas with the same volume as the particle; F L mainly comes from the radial gas velocity gradient in the pipeline; the gas velocity is smaller closer to the wall surface and the largest at the center of the pipeline; according to Bernoulli's equation, the pressure above the particle near the bottom of the pipeline is small and the pressure below is large, thus forming a vertical upward lift force.

[0026] In the present invention, for the horizontal section, since the gas density is usually much smaller than the particle density, the buoyancy force can be ignored.

[0027] In some embodiments, at the horizontal section, the transition velocity U g,s ’ is calculated by combining the gravity F of the transported particles G and the Saffman lift F of the transported particles L with Newton's second law. The motion equation of the transported particles is as follows:

[0028]

[0029] where m p is the mass of the transported particles, in kg; F G is the gravity of the transported particles, in N; F L is the Saffman lift of the transported particles, in N; is the velocity U of the transported particles p which is the rate of change of U with time t. U p is the velocity of the transported particles, in m / s.

[0030] In a specific embodiment, the gravity F of the transported particles G is calculated as follows:

[0031]

[0032] where π is the pi; d V is the volume average particle diameter of the transported particles, in m; ρ p is the density of the transported particles, in kg / m 3 ; g is the acceleration due to gravity, in m / s 2 .

[0033] In a specific embodiment, the Saffman lift F L is calculated as follows:

[0034]

[0035] where μ g is the dynamic viscosity of the transport gas, in Pa·s; ρ g is the density of the transport gas, in kg / m 3 ; d V is the volume average particle diameter of the transported particles, in m; U g is the transport gas velocity, in m / s; U p is the velocity of the transported particles, in m / s; is the velocity U of the transport gas g which is the velocity gradient perpendicular to the transport direction. In the present invention, the gravity F of the transported particles G and the Saffman lift F of the transported particles LSubstitute into the motion equation of the particles to obtain:

[0036]

[0037] In the present invention, since the gas motion in the boundary layer near the wall surface in the pipeline can generally be considered as a linear shear flow process, the corresponding gas velocity gradient is constant.

[0038] In a preferred embodiment, The calculation method of is as follows:

[0039]

[0040] Wherein, U g is the conveying gas velocity, m / s; D is the inner diameter of the conveying pipeline, m.

[0041] In a specific embodiment, the motion equation of the conveyed particles adopts boundary conditions, = 0, U p = 0.

[0042] Wherein, the acquisition method of the calculation model formula I of the transition velocity U g,s ’ is: Substitute the calculation formula of into the calculation formula of ; U p = 0; wherein, U g corresponds to the transition velocity U g,s ’ .

[0043] In the present invention, the force conditions of a single particle during the pneumatic conveying process in the vertical section are as follows: The particle climbs along the y direction; in the x direction, the particle is mainly subjected to the gravity F G , buoyancy F B , lift F L and drag force F D . Different from the horizontal section, the lift F L received by the particle in the vertical section mainly originates from the axial velocity difference of the gas; the pressure difference between the upper and lower parts of the particle forms the lift. F D comes from the flow around formed when the air flow passes through the particle, and its magnitude mainly depends on the slip velocity between the gas and the particle, the windward area of the particle and the drag coefficient.

[0044] In the present invention, for the vertical section, due to the very small axial pressure gradient, the buoyancy and lift can be ignored.

[0045] In some embodiments, at the vertical section, the transition velocity U g,s ”By the drag force F of the transported particles D and the gravity F of the transported particles G Combined with Newton's second law, the motion equation of the transported particles is obtained as follows:

[0046]

[0047] where, m p is the mass of the transported particles, kg; F G is the gravity of the transported particles, N; F D is the drag force of the transported particles, N; is the rate of change of the velocity U of the transported particles with time t, and U p is the velocity of the transported particles, m / s. In a specific embodiment, the gravity F of the transported particles p is calculated as follows: G where, π is the pi; d

[0048]

[0049] is the volume average particle size of the transported particles, m; ρ V is the density of the transported particles, kg / m p ; g is the acceleration due to gravity, m / s 3 ; 2 .

[0050] In a specific embodiment, the drag force F of the transported particles D is calculated as follows:

[0051]

[0052] where, C D is the drag coefficient; π is the pi; d V is the volume average particle size of the transported particles, m; ρ p is the density of the transported particles, kg / m 3 ; U g is the conveying gas velocity, m / s; U p is the velocity of the transported particles, m / s;

[0053] More preferably, C D takes the value of 0.44. In a specific embodiment, the motion equation of the transported particles adopts boundary conditions, U p = 0.

[0054] where, the acquisition method of the calculation model formula II of the transition velocity U g,s ” is: By the drag force F of the transported particles D and the gravity F of the transported particles GSubstituting into the motion equation of the particle, we get:

[0055]

[0056] where C D is closely related to the Reynolds number Re p of the particle. Re p is calculated according to the following formula: Re p = ρ g (U g - U p )d V / μ g . As Re p increases, the motion of the particle is in the laminar flow region, the transition region, and the turbulent flow region respectively; determining the drag coefficient corresponding to the particle motion in the turbulent flow region, that is, C D = 0.44; U p = 0; where U g corresponds to the transition velocity U g,s ” .

[0057] In the present invention, the force on a single particle during the pneumatic conveying process in the bending section is as follows: the particle moves obliquely upward; when passing through the bending section, the motion direction of the powder particle gradually transitions from the horizontal motion corresponding to θ = 0° to the vertical motion corresponding to θ = 90°. The particle is mainly affected by the gravity F G , the buoyancy F B , the lift F L , the drag force F D and the centrifugal force F C . F C comes from the circular motion of the particle along the bending section and is a fictitious force. The suspension and settlement of the particle in the pipeline depend on the force on the particle in the vertical direction.

[0058] In some embodiments, at the bending section, the transition velocity U g,s ”’ is calculated by combining the drag force F D of the conveyed particle, the gravity F G of the conveyed particle, the Saffman lift F L of the conveyed particle, and the centrifugal force F c of the conveyed particle with Newton's second law. The motion equation of the conveyed particle is:

[0059]

[0060] where m p is the mass of the conveyed particle, kg; F DThe drag force for transporting particles, N; F G The gravitational force for transporting particles, N; F L The Saffman lift force for transporting particles, N; F c The centrifugal force for transporting particles, N; is the velocity gradient for transporting particles within the time period t; θ is the movement angle of the transported particles. In the present invention, the motion equation of the above particles can be simplified as:

[0061]

[0062] In a specific embodiment, the gravitational force F of the transported particles G is calculated as follows:

[0063]

[0064] where, π is the pi; d V is the volume average particle size of the transported particles, m; ρ p is the density of the transported particles, kg / m 3 ; g is the gravitational acceleration, m / s 2 .

[0065] In a specific embodiment, the Saffman lift force F L is calculated as follows:

[0066]

[0067] where, μ g is the dynamic viscosity of the transport gas, Pa·s; ρ g is the density of the transport gas, kg / m 3 ; d V is the volume average particle size of the transported particles, m; U g is the velocity of the transport gas, m / s; U p is the velocity of the transported particles, m / s; is the velocity U of the transport gas g in the velocity gradient perpendicular to the transport direction.

[0068] In a specific embodiment, the drag force F of the transported particles D is calculated as follows:

[0069]

[0070] where, C D is the drag coefficient; π is the pi; d V is the volume average particle size of the transported particles, m; ρ p is the density of the transported particles, kg / m 3 ; U gis the velocity of the conveying gas, m / s; U p is the velocity of the conveyed particles, m / s.

[0071] Preferably, C D takes the value of 0.44.

[0072] In a specific embodiment, the centrifugal force F of the conveyed particles c is calculated as follows:

[0073]

[0074] where π is the pi; d V is the volume average particle size of the conveyed particles, m; ρ p is the density of the conveyed particles, kg / m 3 ; U p is the velocity of the conveyed particles, m / s; r is the bending radius of the bending section, m.

[0075] In a specific embodiment, the motion equation of the particles adopts boundary conditions, U p = 0.

[0076] where the transition velocity U g,s ”’ is obtained by substituting the drag force F of the conveyed particles D , the gravitational force F of the conveyed particles G , the Saffman lift F of the conveyed particles L , and the centrifugal force F of the conveyed particles c into the simplified motion equation of the above particles, resulting in:

[0077]

[0078] where, U p = 0; where U g corresponds to the transition velocity U g,s ”’ .

[0079] In some embodiments, the d V is measured by a particle size analyzer.

[0080] In some embodiments, the ρ p is measured by a particle density analyzer.

[0081] In some embodiments, the ρ g is calculated based on the pressure and gas temperature of the conveying pipeline; specifically, its calculation method is as follows:

[0082]

[0083] Among them, P is the absolute pressure of the conveying pipeline, in Pa; M is the molar mass of the gas, in g / mol; R is the ideal gas constant, with a value of 8.314 J / (mol·K); T is the gas temperature, in K.

[0084] In some embodiments, the conveyed particles include biomass.

[0085] In some embodiments, the particle size of the conveyed particles is 0.01 mm to 5 mm.

[0086] In some embodiments, the inner diameter of the conveying pipeline is 0.01 m to 0.2 m.

[0087] In some embodiments, the conveying gas in the conveying pipeline is compressed air.

[0088] In the present invention, the transition velocity U g,s can describe the suspension and settlement of a single particle in the pipeline. However, in the actual pneumatic conveying process, collisions continuously occur inside the particle group and between the particles and the pipe wall, resulting in the energy and momentum of a single particle changing at all times. This makes it impossible to directly use U g,s to calculate the motion state of the particle group.

[0089] Among them, the acquisition method of the pneumatic conveying model IV is: determining the functional relationship between the critical choking gas velocity and the solid mass flux:

[0090]

[0091] Among them, m s is the solid mass flux, which is used to measure the particle collision intensity in the pipeline; the faster the particle movement speed and the higher the solid phase concentration, the more intense the collisions inside the particle group and between the particle group and the pipe wall; the calculation formula of the solid mass flux is:

[0092] M s = U p C s

[0093] Among them, U p is the velocity of the conveyed particles, in m / s; C s is the solid phase concentration, in kg / m 3 .

[0094] In the present invention, the fitting coefficients a and b can be obtained through nonlinear regression analysis.

[0095] The present invention also provides a control method for pneumatic conveying, which includes the following steps:

[0096] ss1. Collect pneumatic conveying information and calculate the conveying gas velocity U of the conveying gas according to Equation V. g The pneumatic conveying information includes the inner diameter D of the conveying pipeline, the pressure P of the conveying pipeline, the temperature T of the conveying gas, and the volume flow rate Q of the conveying gas.

[0097]

[0098] ss2. Compare the conveying gas velocity U of the conveying gas g with the critical blockage gas velocity U g,cb The critical blockage gas velocity U g,cb is calculated by the method of establishing the pneumatic conveying model as described above.

[0099] When U g is greater than U g,cb , repeat step S1 to continuously monitor the conveying gas velocity of the conveying gas.

[0100] When U g is less than or equal to U g,cb , adjust the volume flow rate Q of the conveying gas and repeat step S1 to keep U g greater than U g,cb .

[0101] In some embodiments, when the conveying pipeline is a horizontal section, a bent section or a vertical section, by adjusting the volume flow rate Q of the conveying gas, keep U g greater than U g,cb .

[0102] In some embodiments, when the conveying pipeline includes at least two of a horizontal section, a bent section and a vertical section, by adjusting the volume flow rate of the conveying gas, keep U g greater than any U g,cb .

[0103] In a specific embodiment, the control method of the pneumatic conveying is carried out in a pneumatic conveying system, and the pneumatic conveying system includes a gas supply unit, a material storage unit, and a material receiving unit; an air flow pipeline is provided between the gas supply unit and the material storage unit; a discharge port is provided at the bottom of the material storage unit; a conveying pipeline is provided between the material storage unit and the material receiving unit, and the conveying pipeline includes a horizontal section, a bent section and a vertical section, and the two ends of the bent section are respectively connected to the horizontal section and the vertical section; a gas flow meter and a temperature measuring instrument are provided on the air flow pipeline; a first pressure sensor, a second pressure sensor and a third pressure sensor are respectively provided on the horizontal section, the bent section and the vertical section.

[0104] In a preferred embodiment, a first branch, a second branch, and a third branch are further provided between the air supply unit and the material storage unit; one end of the air flow pipeline is connected to the air supply unit, and the other end is respectively connected to the inlet ends of the first branch, the second branch, and the third branch; the outlet ends of the first branch and the second branch are both connected to the material storage unit; the outlet end of the third branch is connected to the conveying pipeline.

[0105] In a preferred embodiment, the conveying pipeline sequentially includes a first vertical section, a first bending section, a horizontal section, a second bending section, a second vertical section, and a third bending section; the first pressure sensor is disposed on the horizontal section, the second pressure sensor is disposed on the second bending section, and the third pressure sensor is disposed on the second vertical section.

[0106] In the present invention, the operation logic of the control method for pneumatic conveying is as follows: The measured values of the gas flowmeter and the pressure sensor are read in real time, and combined with the physical property parameters of the material and the solid mass flux parameters, the conveying gas velocity U is calculated. g And the critical choking gas velocity U g,cb ; Then, by comparing the two, the conveying gas velocity is controlled to be always greater than the critical choking gas velocity, that is, U g > U g,cb , and the target conveying gas velocity U g,t is given. Finally, the computer control system calculates the required target gas volume Q g,t according to the set U t and feeds it back to the gas flowmeter, thereby effectively preventing the material from being blocked during pneumatic conveying.

[0107] The control method provided by the present invention is applicable to the pneumatic conveying system of biomass powder under different pipeline types, different materials, and different operating conditions.

[0108] The present invention also provides a control system for pneumatic conveying, which includes a control unit. The control unit is electrically connected to the gas flowmeter, the first pressure sensor, the second pressure sensor, and the third pressure sensor of the pneumatic conveying system in the control method for pneumatic conveying as described above, and is used to convert the received pressure signal into a gas flow control signal to regulate the gas flowmeter.

[0109] The present invention also provides an electronic device, which includes a memory, a processor, and a computer program stored on the memory and executable on the processor. When the processor executes the computer program, it implements the method for establishing a pneumatic conveying model as described above, or the control method for pneumatic conveying as described above.

[0110] On the basis of conforming to the common knowledge in the art, the above-mentioned preferred conditions can be combined arbitrarily to obtain various preferred examples of the present invention.

[0111] The reagents and raw materials used in the present invention are all commercially available.

[0112] The positive and progressive effects of the present invention are as follows:

[0113] 1. The control method and system of the present invention can accurately calculate the critical choking gas velocity in the conveying pipeline; based on this, the conveying gas velocity in the pipeline can be controlled in real time to make it always greater than the critical choking gas velocity, realizing the anti-blocking of the biomass pneumatic conveying system. The blocking risk in the pneumatic conveying process of biomass powder is effectively reduced.

[0114] 2. The control method and system provided by the present invention can be applied to the biomass powder pneumatic conveying system under different pipeline types, different materials, and different operating conditions. Description of the Drawings

[0115] Figure 1 is the force decomposition diagram of a single particle in the horizontal section of the conveying pipeline in Embodiment 1;

[0116] Figure 2 is the force decomposition diagram of a single particle in the vertical section of the conveying pipeline in Embodiment 1;

[0117] Figure 3 is the force decomposition diagram of a single particle in the bent section of the conveying pipeline in Embodiment 1;

[0118] Figure 4 is the structural schematic diagram of the pneumatic conveying system in Embodiment 1.

[0119] Figure 5 is the control flow schematic diagram when using the pneumatic conveying system in Embodiment 2.

[0120] Description of the Reference Numerals:

[0121] Gas supply unit 1

[0122] Air flow pipeline 101

[0123] First branch 102

[0124] Second branch 103

[0125] Third branch 104

[0126] Gas flowmeter 2

[0127] Material storage unit 3

[0128] First pressure sensor 4

[0129] Second pressure sensor 5

[0130] The third pressure sensor 6

[0131] The material receiving unit 7

[0132] The control unit 8

[0133] The conveying pipeline 9

[0134] The first vertical section 901

[0135] The first bending section 902

[0136] The horizontal section 903

[0137] The second bending section 904

[0138] The second vertical section 905

[0139] The third bending section 906. Specific implementation manners

[0140] The present invention will be further described below by way of embodiments, but the present invention is not limited to the scope of the described embodiments. For the experimental methods without specific conditions noted in the following embodiments, they are carried out according to conventional methods and conditions, or selected according to the product specifications.

[0141] Embodiment 1

[0142] This embodiment discloses a method for establishing a pneumatic conveying model.

[0143] The conveying object in this embodiment is biomass powder with a particle density of 1608 kg / m 3 , and its average particle volume diameter is 313.41 μm; the conveying gas is compressed air; the inner diameter of the conveying pipeline is 0.2 m. Among them, the density ρ g of the compressed air needs to be calculated according to the pressure and gas temperature of the conveying pipeline, and the dynamic viscosity value is 1.79×10 -6 Pa·s, and the calculation method of ρ g is as follows:

[0144]

[0145] Where P is the absolute pressure of the conveying pipeline, Pa; M is the molar mass of the gas, g / mol; R is the ideal gas constant, with a value of 8.314 J / (mol·k); T is the gas temperature, K.

[0146] The method for establishing the pneumatic conveying model includes the following process:

[0147] Step S1: Obtain 18 sets of fitting data (among which, 6 sets are fitting data for the horizontal section, 6 sets are fitting data for the vertical section, and 6 sets are fitting data for the bending section). Each set of fitting data includes the transition velocity U in the conveying pipeline g,s and the critical choking gas velocity U g,s corresponding to the transition velocity U g,cb ;

[0148] The conveying pipeline 9 successively includes a first vertical section 901, a first bending section 902, a horizontal section 903, a second bending section 904, a second vertical section 905, and a third bending section 906;

[0149] The following is the calculation method of the forces that the particles may be subjected to in the conveying pipeline:

[0150] The gravity F of the particles G :

[0151]

[0152] where π is the pi; d V is the volume average particle size of the conveyed particles, m; ρ p is the density of the conveyed particles, kg / m 3 ; g is the acceleration due to gravity, m / s 2 .

[0153] According to Archimedes' principle, the buoyancy F exerted by the gas on the particles B is equal to the gravity of the gas displaced by the particles:

[0154]

[0155] where π is the pi; d V is the volume average particle size of the conveyed particles, m; ρ g is the density of the conveying gas, kg / m 3 ; g is the acceleration due to gravity, m / s 2 .

[0156] The Saffman lift F caused by the gas velocity gradient L :

[0157]

[0158] where μ g is the dynamic viscosity of the conveying gas, Pa·s; ρ g is the density of the conveying gas, kg / m 3 ; d V is the volume average particle size of the conveyed particles, m; U g is the conveying gas velocity, m / s; U p is the velocity of the conveyed particles, m / s; is the velocity U of the conveying gas g Velocity gradient perpendicular to the conveying direction;

[0159] Drag force F D The calculation formula is as follows:

[0160]

[0161] where C D is the drag coefficient, and C D takes the value of 0.44; π is the pi; d V is the volume average particle size of the conveyed particles, m; ρ p is the density of the conveyed particles, kg / m 3 ; U g is the conveying gas velocity, m / s; U p is the velocity of the conveyed particles, m / s.

[0162] Centrifugal force F C The calculation formula is as follows:

[0163]

[0164] where π is the pi; d V is the volume average particle size of the conveyed particles, m; ρ p is the density of the conveyed particles, kg / m 3 ; U p is the velocity of the conveyed particles, m / s; r is the bending radius of the bending section, m.

[0165] The following is the way to obtain the calculation formula of the transition velocity in the horizontal section, vertical section, and bending section:

[0166] a) Analyze the force situation of a single particle near the bottom of the pipeline during the pneumatic conveying process in the horizontal section. Figure 1 is the force decomposition diagram of a single particle in the horizontal section of the conveying pipeline in this embodiment. As Figure 1 shown, the particle moves horizontally along the x direction. In the y direction, the particle is mainly affected by the gravity F G , buoyancy F B and lift force F L . In the horizontal section, F G is the main force causing particle sedimentation. F B comes from the static pressure difference on the particle surface, with the direction vertically upward, and its magnitude is equal to the gravity of the gas with the same volume as the particle. F L mainly comes from the radial gas velocity gradient in the pipeline; the gas flow velocity is smaller closer to the wall surface, and the flow velocity at the center of the pipeline is the largest. According to Bernoulli's equation, the pressure above the particle near the bottom of the pipeline is small, and the pressure below is large, thus forming a vertically upward lift force.

[0167] For the motion equation of a single particle in the horizontal section: Since the gas density is usually much smaller than the particle density, the buoyancy force can be neglected. According to Newton's second law, the motion equation of a single particle near the bottom of the pipeline in the y-direction can be established in the horizontal section:

[0168]

[0169] where m p is the mass of the transported particle, kg; F G is the gravity of the transported particle, N; F L is the Saffman lift of the transported particle, N; is the change rate of the velocity U p of the transported particle with time t, and U p is the velocity of the transported particle, m / s.

[0170] Substituting equations (1) and (3) into equation (6) gives:

[0171]

[0172] Since the gas motion in the boundary layer near the wall in the pipeline can usually be considered as a linear shear flow process, the corresponding gas velocity gradient is constant. Therefore, the gas velocity gradient term in equation (7) can be expressed as:

[0173]

[0174] where U g is the gas transport velocity, m / s; D is the inner diameter of the transport pipeline, m;

[0175] Assume that the particle is in a suspended state initially. As the gas velocity decreases, the lift force acting on the particle decreases continuously. Under the action of gravity, the particle will start to settle. The minimum gas velocity required to maintain the particle suspension is defined as the transition velocity. When the gas velocity in the pipeline is less than this velocity, the particle will settle, and vice versa, the particle will be vertically lifted.

[0176] Substituting the boundary condition U p = 0, and equation (8) into equation (7), the calculation model of the transition velocity in the horizontal section can be established:

[0177]

[0178] where U g,s ’ is the transition velocity in the horizontal section of the transport pipeline, m / s; π is the pi; d V is the volume average particle diameter of the transported particle, m; ρ pis the density of the transported particles, kg / m 3 ; g is the acceleration due to gravity, m / s 2 ; ρ g is the density of the transport gas, kg / m 3 ; μ g is the dynamic viscosity of the transport gas, Pa·s; D is the inner diameter of the transport pipeline, m.

[0179] b) Analyze the force acting on a single particle near the bottom of the pipeline during the pneumatic conveying process in the second vertical section. Figure 2 is the force decomposition diagram of a single particle in the vertical section of the transport pipeline in this embodiment. As Figure 2 shown, the particle moves vertically upward along the y direction. In the x direction, the solid particle is mainly subjected to the gravitational force F G , the buoyant force F B , the lift force F L and the drag force F D . Different from the horizontal section, the lift force F L acting on a single particle in the vertical section mainly comes from the axial velocity difference of the gas. The pressure difference between the upper and lower parts of the particle forms the lift force. F D results from the flow around the particle when the air flow passes through the particle, and its magnitude mainly depends on the slip velocity between the gas and the particle, the windward area of the particle and the drag coefficient.

[0180] For the motion equation of a single particle in the second vertical section: Since the axial pressure gradient is very small, the buoyant force and the lift force can be neglected. According to Newton's second law, the motion equation of a single particle in the x direction during the pneumatic conveying process in the vertical section can be established:

[0181]

[0182] Substituting equations (1)(4) into equation (10) gives:

[0183]

[0184] When the sum of the forces acting on the particle in the x direction is 0, the acceleration of the particle in the x direction disappears. When the axial velocity of the particle is 0, the particle reaches the critical suspension state. Substituting the boundary conditions and U p = 0 into equation (11), the calculation model of the transition velocity in the vertical section can be established:

[0185]

[0186] where, U g,s ” is the transition velocity in the vertical section of the transport pipeline, m / s; d V is the volume average particle size of the transported particles, m; ρ pis the density of the conveyed particles, kg / m 3 ; g is the acceleration due to gravity, m / s 2 ; ρ g is the density of the conveying gas, kg / m 3 ; C D is the drag coefficient, C D takes the value of 0.44.

[0187] In equation (12), the magnitude of C D is closely related to the particle Reynolds number Re p , Re p is calculated according to the following formula: Re p =ρ g (U g -U p )d V / μ g . As Re p increases, the motion of the particles is in the laminar flow region, the transition region, and the turbulent flow region respectively. To simplify the calculation, the drag coefficient corresponding to the turbulent flow region is taken, that is, C D =0.44.

[0188] c) Analyze the force acting on a single particle near the bottom of the pipeline during the pneumatic conveying process in the second bending section. In the elbow, the direction of particle motion continuously changes, but it can always be decomposed into the sum of vertical and horizontal motions. Therefore, the same idea as that for the horizontal pipe and the vertical pipe can be used to model the transition velocity corresponding to the elbow. Figure 3 is the force decomposition diagram of a single particle in the bending section of the conveying pipeline in this embodiment. As Figure 3 shown, the particle moves obliquely upward; where θ represents the angle between the conveying gas velocity and the horizontal plane. In the x direction, the solid particle is mainly affected by the gravity F G , the buoyancy F B , the lift F L , the drag force F D and the centrifugal force F C . F C comes from the circular motion of the particle along the bending section and is a fictitious force. The suspension and settlement of the particle in the pipeline depend on the force acting on the particle in the vertical direction.

[0189] For the motion equation of a single particle in the second bending section: The buoyancy force acting on the particle can be ignored. When passing through the bending section, the direction of particle motion gradually transitions from the horizontal motion corresponding to θ = 0° to the vertical motion corresponding to θ = 90°. Therefore, it is necessary to integrate each force acting on the particle from θ = 0° to θ = 90°, and then according to Newton's second law, the motion equation of the powder particles in the vertical direction can be established:

[0190]

[0191] Simplifying equation (13) yields:

[0192]

[0193] Substituting equations (1)(3)(4)(5) into equation (14), we obtain:

[0194]

[0195] The boundary conditions and U p = 0 is substituted into equation (15), and the transition velocity calculation model in the bending section can be established:

[0196]

[0197] Among them, U g,s ”’ is the transition speed of the bend section in the pipeline, m / s; d V is the volume average particle size of the transported particles, m; ρ p is the density of the transported particles, kg / m 3 ; g is the acceleration due to gravity, m / s 2 ρ g is the density of the conveying gas, kg / m 3 ;μ g is the dynamic viscosity of the transported gas, Pa·s; D is the inner diameter of the transport pipeline, m; C D is the drag coefficient, C D The value is 0.44.

[0198] Among them, d V Measured by particle size analyzer; ρ p Measured by particle density meter; ρ g Calculated based on ambient temperature and average pressure in the delivery pipeline.

[0199] S2. The particle group collision effect can be characterized by the solid mass flux. The faster the particle movement speed and the higher the solid concentration, the more intense the collision between the particle group and the tube wall. The solid mass flux is calculated as:

[0200] m s =U p C s (17)

[0201] The pneumatic conveying model IV is obtained by determining the functional relationship between the critical blocking gas velocity and the solid mass flux:

[0202]

[0203] Substitute the above-fitted data into the pneumatic conveying model, where the pneumatic conveying model is as follows:

[0204]

[0205] where, U g,cb is the critical choking gas velocity in the conveying pipeline, m / s; U g,s is the transition velocity in the conveying pipeline, m / s; m s is the mass flux of the conveyed particles, kg / (m 2 ·s); a and b are fitting coefficients respectively.

[0206] where, U p is the velocity of the conveyed particles, m / s; C s is the solid-phase concentration, kg / m 3 .

[0207] According to the position of the particles in the conveying pipeline (horizontal section, vertical section or bending section), conduct 6 groups of pneumatic conveying experiments under different solid mass fluxes. Based on Equation (18), obtain the parameter a through power function fitting. Substitute the parameter a into Equation (19) and obtain the parameter b through proportional function fitting.

[0208] where, under the conditions of three solid mass fluxes with a pipeline inner diameter of 0.02 m and m s = 302, 451, 605 kg / (m 2 ·s), and three solid mass fluxes with a pipeline inner diameter of 0.05 m and m s = 557, 692, 934 kg / (m 2 ·s), conduct biomass powder pneumatic conveying experiments; specifically, the experimental test method for the critical choking gas velocity U g,cb is as follows: keep the solid mass flow rate constant by controlling the conveying pressure difference unchanged, and then gradually reduce the regulating gas (the third branch 104) until the pipeline is blocked. The critical choking gas velocity U g,cb can be calculated based on the total intake air volume, pipeline temperature and pressure at the time of blockage.

[0209] Calculate the value of U g,s according to the calculation formula in step S1, fit Equation 19, and then substitute the obtained parameters a and b into Equation (19). In Equation (19), U g,cb is obtained through the above-mentioned conveying experiment test, while U g,s is calculated through known parameters such as dv, ρ g .

[0210] The critical choking gas velocity under different pipe inner diameters and solid mass fluxes can be calculated, and the results are shown in Table 1. Table 1 presents the analysis results of the actual and calculated values of the critical choking gas velocity under different inner diameters and solid mass fluxes of the conveying pipeline. Among them, the deviation is calculated as: (U g,cb Calculated value - U g,cb Actual value) / U g,cb Actual value × 100%.

[0211] Table 1

[0212]

[0213] As can be seen from the above table, when calculating the critical choking gas velocity using this embodiment, the deviation between the calculated value of the critical choking gas velocity and the actual value of the critical choking gas velocity is within ±11.70%; furthermore, the deviation between the calculated value of the critical choking gas velocity and the actual value of the critical choking gas velocity is mostly within ±6%, effectively meeting the calculation requirements of the critical choking gas velocity for the biomass pneumatic conveying system.

[0214] Example 2

[0215] This embodiment discloses a control method for pneumatic conveying; this control method for pneumatic conveying is carried out in a pneumatic conveying system.

[0216] Figure 4 is a schematic structural diagram of the pneumatic conveying system in this embodiment. The pneumatic conveying system includes a gas supply unit 1, a material storage unit 3, and a material receiving unit 7; there is an air flow pipeline 101 between the gas supply unit 1 and the material storage unit 3; there is a discharge port at the bottom of the material storage unit 3; there is a conveying pipeline 9 between the material storage unit 3 and the material receiving unit 7, and the conveying pipeline 9 successively includes a first vertical section 901, a first bending section 902, a horizontal section 903, a second bending section 904, a second vertical section 905, and a third bending section 906; a first pressure sensor 4 is arranged on the horizontal section 903, a second pressure sensor 5 is arranged on the second bending section 904, and a third pressure sensor 6 is arranged on the second vertical section 905.

[0217] Among them, there are also a first branch 102, a second branch 103, and a third branch 104 between the gas supply unit 1 and the material storage unit 3; one end of the air flow pipeline 101 is connected to the gas supply unit 1, and the other end is respectively connected to the inlet ends of the first branch 102, the second branch 103, and the third branch 104; the outlet ends of the first branch 102 and the second branch 103 are both connected to the material storage unit 3; the outlet end of the third branch 104 is connected to the conveying pipeline 9.

[0218] The control method for pneumatic conveying further includes a control system for pneumatic conveying, which includes a control unit 8. The control unit 8 is electrically connected to the gas flow meter 2, the first pressure sensor 4, the second pressure sensor 5, and the third pressure sensor 6 of the pneumatic conveying system in the control method for pneumatic conveying as described above, and is used to convert the received pressure signal into a gas flow control signal to regulate the gas flow meter.

[0219] Figure 5 It is a schematic diagram of the control process when the pneumatic conveying system is adopted in this embodiment.

[0220] The control method for pneumatic conveying includes the following steps:

[0221] ss1. Collect the pneumatic conveying information, and calculate the conveying gas velocity U of the conveying gas according to the formula V g ; the pneumatic conveying information includes the inner diameter D of the conveying pipeline, the pressure P of the conveying pipeline, the temperature T of the conveying gas, and the volume flow rate Q of the conveying gas;

[0222]

[0223] ss2. Compare the conveying gas velocity U of the conveying gas g with the critical choking gas velocity U g,cb ; the critical choking gas velocity U g,cb is calculated through the pneumatic conveying model established in Embodiment 1;

[0224] When U g is greater than U g,cb , repeat step S1 to continuously monitor the conveying gas velocity of the conveying gas;

[0225] When U g is less than or equal to U g,cb , adjust the volume flow rate Q of the conveying gas, and repeat step S1 to keep U g greater than U g,cb .

[0226] In addition to the above control method, the target conveying gas velocity U g,t can also be set according to the maximum deviation between the calculated value and the actual value of the critical choking gas velocity. According to the calculation deviation result of Embodiment 1, the predicted deviation between the calculated value and the actual value of the critical choking gas velocity is mostly within ±6%, and the maximum deviation is -11.7%. Therefore, the target conveying gas velocity U g,t can be controlled in the control system to be more than 111.7% of the calculated value of the critical choking gas velocity U g,cb , that is, U g,t >1.117U g,cb . U g,tThe higher it is above the calculated value of the critical plugging gas velocity, the higher the corresponding energy consumption, but the greater the anti-plugging safety redundancy of the conveying system.

[0227] Example 3

[0228] This embodiment discloses an electronic device, which includes a memory, a processor, and a computer program stored in the memory and configured to run on the processor. When the processor executes the computer program, it implements the method for establishing a pneumatic conveying model provided in the above-mentioned Embodiment 1 and the control method for pneumatic conveying provided in the above-mentioned Embodiment 2. The electronic device is merely an example and should not impose any limitations on the functions and usage scope of the embodiments of the present disclosure.

[0229] The electronic device may be presented in the form of a general-purpose computing device. For example, it may be a server device. The components of the electronic device may include, but are not limited to: the above-mentioned at least one processor, the above-mentioned at least one memory, and a bus connecting different system components (including the memory and the processor).

[0230] The bus includes a data bus, an address bus, and a control bus.

[0231] The memory may include volatile memory, such as random access memory (RAM) and / or cache memory, and may further include read-only memory (ROM).

[0232] The memory may also include program tools (or utilities) having a set (at least one) of program modules. Such program modules include, but are not limited to: an operating system, one or more application programs, other program modules, and program data. Each or some combination of these examples may include the implementation of a network environment.

[0233] The processor executes various functional applications and data processing by running the computer program stored in the memory, such as the method for establishing a pneumatic conveying model provided in the above-mentioned Embodiment 1 and the control method for pneumatic conveying provided in the above-mentioned Embodiment 2.

[0234] The electronic device may also communicate with one or more external devices (such as a keyboard, a pointing device, etc.). Such communication may be carried out through an input / output (I / O) interface. Moreover, the electronic device may also communicate with one or more networks (such as a local area network (LAN), a wide area network (WAN), and / or a public network, such as the Internet) through a network adapter. As shown in the figure, the network adapter communicates with other modules of the electronic device through the bus. It should be understood that other hardware and / or software modules may be used in combination with the electronic device, including but not limited to: microcode, device drivers, redundant processors, external disk drive arrays, RAID (disk array) systems, tape drives, and data backup storage systems, etc.

[0235] It should be noted that although several units / modules or sub-units / modules of the electronic device are mentioned in the above detailed description, this division is merely exemplary and not mandatory. In fact, according to the embodiments of the present disclosure, the features and functions of two or more units / modules described above can be embodied in one unit / modules. Conversely, the features and functions of one unit / modules described above can be further divided and embodied by multiple units / modules.

Claims

1. A method for establishing a pneumatic conveying model, characterized in that: It includes the following steps: S1, obtaining at least two sets of fitting data, each set of fitting data including the transition velocity U in the transport pipeline g,s , and the transition speed U g,s The corresponding critical blockage velocity U g,cb ; The conveying pipeline includes a horizontal section, a bent section or a vertical section; At the horizontal section, the transition speed U g,s ’ The calculation model is as follows: At the vertical section, the transition speed U g,s The calculation model of " is as follows: At the bending section, the transition speed U g,s The calculation model of ' is as follows: Among them, d V is the volume average particle size of the transported particles, m; ρ p is the density of the transported particles, kg / m 3 ; g is the acceleration due to gravity, m / s 2 ρ g is the density of the conveying gas, kg / m 3 ;μ g is the dynamic viscosity of the transported gas, Pa·s; D is the inner diameter of the transport pipeline, m; C D is the drag coefficient; S2. Substituting the fitting data into a pneumatic conveying model, the pneumatic conveying model is as shown in Formula IV: Among them, U g,cb is the critical blocking gas velocity in the transmission pipeline, m / s; U g,s is the transition velocity in the transport pipeline, m / s; m s is the mass flux of transported particles, kg / (m 2 ·s); a and b are fitting coefficients respectively; S3. Fitting coefficients a and b are obtained by fitting, and the pneumatic conveying model is obtained by training.

2. The method for establishing a pneumatic conveying model according to claim 1, characterized in that: At the horizontal section, the transition speed U g,s ’ The gravity F of the transported particles G and the Saffman lift force F of the transported particles L Combined with Newton's second law, the motion equation of the conveying particles is calculated as follows: Among them, m p is the mass of the transported particles, kg; F G is the gravity of the transported particles, N; F L is the Saffman lift force for transporting particles, N; is the particle conveying speed U p The rate of change over time t, U p is the speed of conveying particles, m / s; Preferably, the gravity F of the transported particles G The calculation formula is as follows: Among them, π is the ratio of circumference to diameter; d V is the volume average particle size of the transported particles, m; ρ p is the density of the transported particles, kg / m 3 ; g is the acceleration due to gravity, m / s 2 ; Preferably, the Saffman lift F L The calculation formula is as follows: Among them, μ g is the dynamic viscosity of the transported gas, Pa·s; ρ g is the density of the conveying gas, kg / m 3 ;d V is the volume average particle size of the transported particles, m; U g is the conveying gas velocity, m / s; U p is the speed of conveying particles, m / s; is the speed of the transported gas, U g The velocity gradient perpendicular to the conveying direction; More preferably, The calculation method is as follows: Among them, U g is the conveying gas velocity, m / s; D is the inner diameter of the conveying pipeline, m; Preferably, the motion equation for transporting particles adopts boundary conditions, U p =0.

3. The method for establishing a pneumatic conveying model according to claim 1, characterized in that: At the vertical section, the transition speed U g,s "Through the drag force F of the transported particles D and the gravity F of the transported particles G Combined with Newton's second law, the motion equation of the conveying particles is calculated as follows: Among them, m p is the mass of the transported particles, kg; F G is the gravity of the transported particles, N; F D is the drag force for transporting particles, N; is the particle conveying speed U p The rate of change over time t, U p is the speed of conveying particles, m / s; Preferably, the gravity F of the transported particles G The calculation formula is as follows: Among them, π is the ratio of the circumference of a circle; d V is the volume average particle size of the transported particles, m; ρ p is the density of the transported particles, kg / m 3 ; g is the acceleration due to gravity, m / s 2 ; Preferably, the drag force F for transporting particles is D The calculation formula is as follows: Among them, C D is the drag coefficient; π is the circumference of a circle; d V is the volume average particle size of the transported particles, m; ρ p is the density of the transported particles, kg / m 3 ; U g is the conveying gas velocity, m / s; U p is the speed of conveying particles, m / s; More preferably, C D The value is 0.44; Preferably, the motion equation for transporting particles adopts boundary conditions, U p =0.

4. The method for establishing a pneumatic conveying model according to claim 1, characterized in that: At the bending section, the transition speed U g,s ”'Through the drag force F of the transported particles D , Gravity of transported particles F G , Saffman lift force F for transporting particles L , Centrifugal force F of transported particles c Combined with Newton's second law, the motion equation of the conveying particles is calculated as follows: Among them, m p is the mass of the transported particles, kg; F D is the drag force for transporting particles, N; F G is the gravity of the transported particles, N; F L is the Saffman lift force for transporting particles, N; F c is the centrifugal force for transporting particles, N; is the velocity gradient of the transported particles in the time period t; θ is the movement angle of the transported particles; Preferably, the gravity F of the transported particles G The calculation formula is as follows: Among them, π is the ratio of the circumference of a circle; d V is the volume average particle size of the transported particles, m; ρ p is the density of the transported particles, kg / m 3 ; g is the acceleration due to gravity, m / s 2 ; Preferably, the Saffman lift F L The calculation formula is as follows: Among them, μ g is the dynamic viscosity of the transported gas, Pa·s; ρ g is the density of the conveying gas, kg / m 3 ;d V is the volume average particle size of the transported particles, m; U g is the speed of the conveying gas, m / s; U p is the speed of conveying particles, m / s; is the speed of the transported gas, U g The velocity gradient perpendicular to the conveying direction; Preferably, the drag force F for transporting particles is D The calculation formula is as follows: Among them, C D is the drag coefficient; π is the circumference of a circle; d V is the volume average particle size of the transported particles, m; ρ p is the density of the transported particles, kg / m 3 ; U g is the conveying gas velocity, m / s; U p is the speed of conveying particles, m / s; More preferably, C D The value is 0.44; Preferably, the centrifugal force F for conveying particles c The calculation formula is as follows: Among them, π is the ratio of the circumference of a circle; d V is the volume average particle size of the transported particles, m; ρ p is the density of the transported particles, kg / m 3 ; U p is the speed of conveying particles, m / s; r is the bending radius of the bending section, m; Preferably, the motion equation for transporting particles adopts boundary conditions, U p =0.

5. The method for establishing a pneumatic conveying model according to claim 1, characterized in that: The method for establishing the pneumatic conveying model satisfies one or more of the following conditions: ①The above V Measured by particle size analyzer; ②The above p Measured by particle density meter; ③The above g Calculation is performed based on the pressure and gas temperature of the delivery pipeline; ④ The transport particles include biomass; ⑤ The particle size of the conveying particles is 0.01mm to 5mm; ⑥The inner diameter of the conveying pipeline is 0.01m~0.2m.

6. A method for controlling pneumatic conveying, characterized in that: It includes the following steps: ss1. Collect pneumatic conveying information and calculate the conveying gas velocity U of the conveying gas according to formula V g The pneumatic conveying information includes the inner diameter D of the conveying pipeline, the pressure P of the conveying pipeline, the temperature T of the conveying gas, and the volume flow rate Q of the conveying gas; ss2. Compare the conveying gas velocity U of the conveying gas g and critical blockage velocity U g,cb The critical blocking velocity U g,cb Calculated by the method for establishing a pneumatic conveying model as described in any one of claims 1 to 5; When U g Greater than U g,cb When the transmission gas velocity is continuously monitored, step S1 is repeated; When U g Less than or equal to U g,cb When U g Greater than U g,cb .

7. The pneumatic conveying control method according to claim 6, characterized in that: The control method of pneumatic conveying satisfies one of the following conditions: ① When the conveying pipeline is a horizontal section, a curved section or a vertical section, the volume flow rate Q of the conveying gas is adjusted to maintain U g Greater than U g,cb ; ② When the delivery pipeline includes at least two of the horizontal section, the bending section and the vertical section, the volume flow rate of the delivery gas is adjusted to maintain U g Greater than any U g,cb .

8. The pneumatic conveying control method according to claim 7, characterized in that: The pneumatic conveying control method is performed in a pneumatic conveying system, which includes an air supply unit, a material storage unit, and a material receiving unit; An air flow duct is provided between the air supply unit and the material storage unit; A discharge port is provided at the bottom of the material storage unit; A conveying pipeline is provided between the material storage unit and the material receiving unit, and the conveying pipeline includes a horizontal section, a bending section and a vertical section, and two ends of the bending section are respectively connected to the horizontal section and the vertical section; The gas flow pipe is provided with a gas flow meter and a temperature meter; the horizontal section, the bending section, and the vertical section are respectively provided with a first pressure sensor, a second pressure sensor, and a third pressure sensor; Preferably, a first branch, a second branch and a third branch are further provided between the air supply unit and the material storage unit; one end of the air flow pipeline is connected to the air supply unit, and the other end is respectively connected to the inlet end of the first branch, the inlet end of the second branch and the inlet end of the third branch; the outlet end of the first branch and the outlet end of the second branch are both connected to the material storage unit; the outlet end of the third branch is connected to the conveying pipeline; Preferably, the conveying pipeline includes a first vertical section, a first bending section, a horizontal section, a second bending section, a second vertical section and a third bending section in sequence; the first pressure sensor is arranged on the horizontal section, the second pressure sensor is arranged on the second bending section, and the third pressure sensor is arranged on the second vertical section.

9. A pneumatic conveying control system, characterized in that: It includes a control unit, which is electrically connected to the gas flow meter, the first pressure sensor, the second pressure sensor, and the third pressure sensor of the pneumatic conveying system in the pneumatic conveying control method as described in claim 8, and is used to convert the received pressure signal into a gas flow control signal to regulate the gas flow meter.

10. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the computer program, the method for establishing a pneumatic conveying model as described in any one of claims 1 to 5 is implemented, or the method for controlling pneumatic conveying as described in any one of claims 6 to 8 is implemented.

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