Intelligent grout mixing and weighing device, control method and system parameter estimation method

Abstract

The present application relates to the technical fields of industrial fluid proportioning and process control, and discloses an intelligent slurry proportioning and weighing device, a control method and a system parameter estimation method, which comprises a slurry proportioning barrel for injecting slurry and clean water. The slurry proportioning barrel is provided with sensors for measuring the density and weight of the slurry in the barrel, and the injection amount of slurry and clean water can be adjusted according to the measurement results. By combining the mass and density for comparison, the accuracy of judgment is improved, and the beneficial effects of high proportioning accuracy, high automation degree, reusable return slurry, saving of slurry usage, improved sensor accuracy and reduced system parameter error are achieved.

Description

Technical Field

[0001] This invention relates to the field of industrial fluid proportioning and process control technology, and in particular to an intelligent slurry weighing device, control method, and system parameter estimation method. Background Technology

[0002] In fields such as civil engineering, oil drilling, and mining, it is necessary to prepare slurries of specific densities according to process requirements. Traditional methods, based on manual experience, calculate the required amounts of water and slurry, then rely on operators' experience to manually control the opening and timing of the water and slurry valves, using flow meters or simple level gauges for rough measurement. This method is highly susceptible to human factors such as operator skill level and attention span, resulting in low mixing accuracy. The density of the prepared slurry often deviates significantly from the target density, failing to meet the refined quality requirements of modern engineering.

[0003] The existing automatic control method for mixing can determine whether the density of the slurry in the mixing tank is equal to the set density. If it does not meet the set density, it will adjust the amount of clean water and raw slurry added. This method is simplistic, has a certain degree of error, and is prone to producing unqualified slurry that has to be scrapped.

[0004] Furthermore, when switching operating conditions (such as changing the pulp or adding pulp), the existing pulp mixing method lacks an effective adaptive control strategy and often still needs to rely on human experience for intervention, resulting in low operating efficiency, low mixing efficiency, and inability to achieve fast and accurate switching of operating conditions.

[0005] In addition, existing slurry mixing methods suffer from several drawbacks: the return slurry cannot be reused, and there is a lack of automatic sensor calibration. Over long-term operation, measurement errors accumulate, affecting the initial accuracy of the mixing ratio. More importantly, before each mixing operation, manual intervention is often required, relying on experience to pre-set system parameters (such as raw slurry density, the rate and time of adding raw slurry and water). This subjective approach leads to significant errors in the initial system parameters, resulting in even greater errors in the accuracy of the mixed slurry and reduced mixing efficiency. Summary of the Invention

[0006] To overcome the problems of low proportioning accuracy, single judgment method, low proportioning efficiency during working condition switching, and increased slurry preparation error due to manual setting of system parameters in the aforementioned background technology, this invention provides an intelligent slurry mixing and weighing device, control method, and system parameter estimation method. By combining mass and density for comparison, the accuracy of judgment is improved. It has the beneficial effects of high proportioning accuracy, high degree of automation, reusable returned slurry, saving raw slurry usage, improving sensor accuracy, and reducing system parameter errors.

[0007] The technical solution of the present invention is as follows: The intelligent slurry mixing and weighing device includes a slurry mixing tank for injecting slurry and clean water. The slurry mixing tank is equipped with sensors that measure the density and weight of the slurry mixed inside the tank, and can adjust the injection volume of slurry and clean water according to the measurement results.

[0008] Preferably, the mixing tank is equipped with a stirring device, which includes a motor and a stirring shaft. The motor is fixed on a mounting bracket at the opening of the mixing tank. The stirring shaft is connected to the output shaft of the motor and extends vertically into the tank from the center of the opening. The stirring shaft is provided with inclined stirring blades.

[0009] Preferably, pressure sensors are installed at different height positions inside the slurry mixing tank, and the density and volume of the slurry can be calculated based on the pressure difference between the two pressure sensors; the weight of the slurry mixing tank is measured by weighing sensors, and several weighing sensors are provided to surround and support the slurry mixing tank.

[0010] In a further preferred embodiment, each weighing sensor is installed on a corresponding weighing column, and a pressure plate extending from the side wall of the mixing tank presses onto the weighing sensor; the bottom ends of all weighing columns are fixedly connected to the base below the mixing tank; the weighing column is also fixed with a protective cover that can cover the weighing sensor.

[0011] Preferably, it also includes a return slurry tank for recovering returned slurry, which can inject returned slurry into a mixing tank; the slurry includes raw slurry and returned slurry; a sludge discharge funnel is also provided next to the return slurry tank, and the returned slurry in the return slurry tank is injected into the mixing tank or the sludge discharge funnel; a pipe for injecting raw slurry into the mixing tank is connected to the mixing tank or the sludge discharge funnel.

[0012] Preferably, it also includes a control cabinet, which is divided into upper and lower layers by a horizontal partition. The electrical control unit and the pneumatic control unit are arranged on the upper layer and connected to the corresponding lines through aviation plugs or quick-connectors in the horizontal partition. The upper layer of the control cabinet is divided into two sides by a vertical partition, with the electrical control unit arranged on one side and the pneumatic control unit arranged on the other side.

[0013] Compared with existing technologies, the advantages of the above technical solution are as follows: (1) This application improves the mixing accuracy of the prepared slurry by using an automated control method, which greatly reduces the deviation between the density of the prepared slurry and the target density required in the actual situation. The mixing accuracy is high and the degree of automation is high. Furthermore, the prepared slurry in the mixing tank is compared with the set density by comparing the measured density with the set density, and the weight calculated by combining the measured density with the measured weight. By combining the two methods to detect and adjust the prepared slurry in the mixing tank, a high-precision mixing ratio can be achieved, which greatly avoids the situation where the prepared slurry is scrapped due to non-compliance.

[0014] (2) The raw slurry and the returned slurry can be injected into the mixing tank together, which can greatly save the amount of raw slurry used; and the raw slurry and the returned slurry can be injected into the drain funnel in time after the corresponding slurry in the mixing tank reaches the set injection amount, which can further improve the accuracy of the slurry preparation in the mixing tank and reduce errors.

[0015] Based on the above technical solution, the present invention also provides a control method for intelligent slurry mixing, used in the above-mentioned intelligent slurry mixing and weighing device, including a calibration stage, a slurry mixing stage, a slurry replenishment stage, and a slurry adjustment stage. In the slurry mixing stage, the slurry replenishment stage, and the slurry adjustment stage, the required volumes of raw slurry, returned slurry, and clean water are calculated according to the slurry volume and density set in the slurry mixing tank and the volume and density of the remaining slurry in the tank, and the injection amount of raw slurry, returned slurry, and clean water is adjusted according to the slurry density and mass in the slurry mixing tank.

[0016] Preferably, during the calibration stage, zero-point calibration and full-scale calibration are performed on the mixing tank and the return tank, respectively; wherein, when the mixing tank is calibrated to full scale, clean water is continuously extracted from the mixing tank for a certain period of time, and the mass change and the cumulative volume of the flow meter are calculated.

[0017] The beneficial effects of the above technical solution are as follows: (1) By using a four-stage control method (calibration, mixing, replenishing, and changing), the complex mixing process is programmed and automated, realizing phased intelligent control. Users only need to set the target parameters, and the system can automatically complete the entire process from calibration to mixing, maintenance, and adjustment, greatly reducing the dependence on the operator's experience, making control simple, and solving the problems of low efficiency of manual mixing and inability to achieve fast and accurate switching of working conditions.

[0018] (2) By performing zero-point calibration and full-scale calibration on the mixing tank and return tank respectively during the calibration stage, the measurement error of each sensor can be eliminated, the accuracy of measurement can be improved, and the starting point of the mixing ratio accuracy can be avoided due to the lack of automatic calibration of the sensor.

[0019] Based on the above technical solutions, the present invention also provides a method for estimating system parameters for slurry preparation, which sets the system parameters to be estimated: water injection time and flow rate, raw slurry injection time and flow rate, and raw slurry density; simulates slurry preparation; calculates multiple sets of system parameters according to the simulated slurry preparation calculation model, and establishes the correspondence between system parameters and prepared slurry density.

[0020] The preferred simulation model for pulp preparation is as follows: Q1 T1_n+Q2 C0 T2_n-Q3_n C T3_n+Q4_n Cf + MassStart_n = MassEnd_n; In the calculation model, Q1 is the flow rate of clean water injection, T1_n is the time of clean water injection, Q2 is the flow rate of raw slurry injection, C0 is the density of raw slurry, T2_n is the time of raw slurry injection, Q3_n is the average injection rate, C is the density of the prepared slurry, T3_n is the injection period time, Q4_n is the average return slurry flow rate, Cf is the average return slurry density, MassStart_n is the mass of slurry in the mixing tank at the start of injection, and MassEnd_n is the mass of slurry in the mixing tank after injection. Simulated slurry preparation: Inject clean water, raw slurry, and returned slurry into the slurry preparation tank, and add the slurry after preparation is completed; During the simulated slurry preparation process, obtain no less than 3 sets of measurable data: T1_n, C0_INT, T2_n, Q3_n, T3_n, Q4_n, C, MassStart_n, and MassEnd_n; Substitute the acquired data set into the calculation model for calculation, where C0_INT is the initial pulp density. Substitute C0 into the calculation model to solve for Q1, Q2 and C. Then, another set of data is obtained during the simulated slurry preparation process: T1_n, T2_n, Q3_n, T3_n, Q4_n, C, MassStart_n, and MassEnd_n. The solved Q1, Q2, and C are substituted into the calculation model to obtain C0. T1_n, T2_n, Q1, Q2, C0, and C in this set are recorded to establish a correspondence between a set of system parameters and the configured slurry density. By changing the values ​​of Q1 and Q2, the pulp mixing calculation process is repeated to establish multiple sets of corresponding relationships.

[0021] The beneficial effects of the above technical solution are as follows: By establishing the correspondence between multiple sets of estimated system parameters and the required slurry density, more accurate system parameters can be set in advance, reducing initial system parameter errors, improving the accuracy of the mixed slurry after preparation, and increasing the proportioning efficiency. Attached Figure Description

[0022] The present invention will be described with reference to the accompanying drawings, wherein: Figure 1 This is a three-dimensional structural diagram of the entire invention; Figure 2 This is a side view of the present invention; Figure 3 This is a schematic diagram of the internal structure of the control cabinet of the present invention.

[0023] Attached reference numerals: 1. Mixing tank; 11. Motor; 12. Agitator shaft; 13. Heat dissipation shield; 14. Mounting bracket; 15. Pressure plate; 2. Weighing sensor; 21. Weighing column; 22. Shield; 3. Base; 31. Bracket; 4. Return tank; 41. Sewage funnel; 42. Cylinder; 43. Mounting seat; 44. Movable rod; 5. Control cabinet; 51. Cabinet door; 52. Horizontal partition; 53. Electrical control unit; 54. Main board; 55. Weighing sensor transmitter; 56. Solenoid valve; 57. Vertical partition; 58. Pneumatic control unit. Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0025] Example 1: As Figures 1 to 3 The intelligent slurry mixing and weighing device shown includes a slurry mixing tank 1 for injecting slurry and clean water. The slurry mixing tank 1 is equipped with a sensor that measures the density and weight of the slurry mixed in the tank, and can adjust the injection volume of slurry and clean water according to the measurement results.

[0026] When preparing slurry in the mixing tank 1, the required slurry volume and water volume to be injected are first calculated based on the density and volume of the slurry, the density of the slurry, and the density of the water. After injecting the slurry and water, it is determined whether the density of the prepared slurry measured by the current sensor is equal to the set slurry density, and whether the weight of the prepared slurry calculated based on the measured density and volume is equal to the weight measured by the sensor. If they are not equal, the amount of slurry and water to be added is recalculated based on the function curve of the change rate of the measured slurry density versus the slurry-to-water volume ratio, until the slurry density and weight meet the requirements. The specific calculation method described above is existing publicly available technology, detailed in Chinese Invention Patent CN108762321A, "Intelligent Stepless Slurry Preparation Implementation Method," and will not be elaborated further here.

[0027] Furthermore, when the volume or density of the slurry in mixing tank 1 needs to be changed or increased, or when slurry needs to be replenished or changed, the required slurry volume and clean water volume can be calculated by setting the density and volume of the slurry, the density of the slurry and the density of the clean water, and adding the volume and density of the remaining slurry in mixing tank 1. This allows for timely adaptive adjustments. Users only need to set the target parameters, and the system can automatically complete the entire process from calibration to preparation, maintenance, and adjustment. This greatly reduces the reliance on the operator's experience, simplifies control, and solves the problems of low operating efficiency, low mixing efficiency, and inability to achieve fast and accurate switching of working conditions.

[0028] Therefore, this embodiment improves the proportioning accuracy of the prepared slurry by using an automated slurry mixing method, significantly reducing the deviation between the density of the prepared slurry and the target density required. The proportioning accuracy is high and the degree of automation is high. In this application, the prepared slurry in the mixing tank 1 is compared with the set density by comparing the measured density with the set density, and the weight calculated by combining the measured density with the measured weight. By combining these two methods to detect and adjust the prepared slurry in the mixing tank 1, high-precision proportioning can be achieved, which greatly avoids the situation where the prepared slurry is scrapped due to being unqualified.

[0029] Example 2: Based on Example 1, the mixing tank 1 is optimized. The mixing tank 1 is equipped with a stirring device, which includes a motor 11 and a stirring shaft 12. The motor 11 is a geared motor 11, and a heat dissipation protective cover 13 is also installed on the motor 11. A mounting bracket 14 is fixed to the opening of the mixing tank 1, and the motor 11 is fixed to the mounting bracket 14. Its output shaft extends vertically downward and is connected to the stirring shaft 12. The stirring shaft 12 extends vertically into the tank from the center of the opening. The motor 11 can drive the stirring shaft 12 to rotate, so that the mixed slurry in the mixing tank 1 is uniformly mixed. The stirring shaft 12 is also equipped with inclined stirring blades. The geared motor 11 and the stirring shaft 12 with inclined stirring blades cooperate to optimize the stirring speed and torque, avoid the mixed slurry from heating up due to excessive stirring or sedimentation due to excessively slow stirring, and improve the uniformity and quality of the mixed slurry.

[0030] Example 3: Based on Example 1, the sensor design is optimized. Pressure sensors are installed at different height positions inside the slurry mixing tank 1. Specifically, the sensors measuring the density of the slurry mixed in the mixing tank 1 are pressure sensors, and capacitive pressure sensors can be selected. The density and volume of the mixed slurry can be calculated based on the pressure difference between the two pressure sensors. The specific calculation method is a known technique and will not be elaborated here. This method of calculating the density and volume of the mixed slurry through pressure difference improves the stability of the measurement data.

[0031] Example 4: Based on Example 1, the sensor is optimized. The weight of the mixing tank 1 is measured by the weighing sensor 2. Several weighing sensors 2 are provided, which surround and support the mixing tank 1. The entire mixing tank 1 is suspended and supported by the weighing sensors 2, so its weight can be measured by the weighing sensors 2.

[0032] Specifically, each weighing sensor 2 is installed on a corresponding weighing column 21, and a horizontally extending pressure plate 15 is fixed to the side wall of the slurry mixing tank 1, pressing the corresponding weighing sensor 2; all weighing columns 21 are arranged vertically, and their bottom ends are fixedly connected to the base 3 below the slurry mixing tank 1; the weighing column 21 is also fixed with a protective cover 22 that can cover the weighing sensor 2, which can protect the weighing sensor 2 from being contaminated by splashed slurry and extend its service life.

[0033] Therefore, by setting up several weighing sensors 2 installed on the weighing column 21 to support the slurry mixing tank 1, the stability of the support can be maintained, and the weight of the slurry can be measured in real time. Furthermore, the measured mass and the measured density of the prepared slurry can be combined to jointly detect the state of the prepared slurry in the tank, and the injection volume of slurry and clean water can be adjusted adaptively according to the detection results.

[0034] Example 5: Based on Example 1, a preferred design is provided, which also includes a return slurry tank 4 for recovering returned slurry. The return slurry tank 4 can inject the returned slurry into the mixing tank 1. The returned slurry is the slurry that returns after injection into the formation, and this slurry can be recycled by injecting it into the mixing tank 1. Therefore, the slurry injected into the mixing tank 1 includes raw slurry and returned slurry. The raw slurry is a slurry with a pre-set density. The raw slurry and returned slurry can be injected together into the mixing tank 1, which can significantly reduce the amount of raw slurry used.

[0035] The return slurry tank 4 is equipped with a sensor to detect the return slurry density. This can be a contact sensor or a pressure sensor connected to a vent pipe inserted into the return slurry tank 4 to indirectly obtain the return slurry density. In this embodiment, the return slurry density is obtained indirectly through a pressure sensor, and a constant airflow is introduced into the vent pipe to prevent blockage. Furthermore, flow meters are installed on the corresponding pipes that introduce raw slurry, return slurry, and clean water into the mixing tank 1 to measure the injection volume.

[0036] Preferably, a drain funnel 41 is also provided on the side of the return slurry tank 4, and the return slurry in the return slurry tank 4 is fed into the mixing tank 1 or the drain funnel 41. The pipe for injecting raw slurry into the mixing tank 1 is connected to the mixing tank 1 or the drain funnel 41. This arrangement allows the raw slurry or return slurry to be injected into the drain funnel 41 in a timely manner after the corresponding slurry in the mixing tank 1 reaches the set injection volume, further improving the accuracy of the slurry preparation in the mixing tank 1.

[0037] In this embodiment, a set of cylinders 42 controls the injection of raw slurry and returned slurry into the discharge funnel 41 or the slurry mixing tank 1. Specifically, the mounting end of each set of cylinders 42 is hinged to a mounting base 43, which is fixed to a bracket 31. The bracket 31 is arranged around the circumference of the slurry mixing tank 1 and is fixedly connected to the base 3 below the slurry mixing tank 1. The output end of the piston rod of the cylinder 42 is hinged to a movable rod 44, which is correspondingly connected to the pipe for injecting raw slurry or returned slurry. When the piston rod extends or retracts, it drives the corresponding pipe to move through the movable rod 44, allowing it to move back and forth between the discharge funnel 41 and the slurry mixing tank 1, stopping above the discharge funnel 41 or the slurry mixing tank 1 to inject slurry. In addition, both the discharge funnel 41 and the returned slurry tank 4 are fixed to the bracket 31 around the circumference of the slurry mixing tank 1.

[0038] Example 6: Based on Example 1, a preferred design is provided, including a control cabinet 5. The control cabinet 5 is fixed to the opening of the slurry mixing tank 1, with its door 51 facing outwards. The control cabinet 5 is divided into upper and lower layers by a horizontal partition 52. The electrical control unit 53 and the pneumatic control unit 58 are located on the upper layer and connected to corresponding lines via aviation plugs or quick-connect fittings within the horizontal partition 52. Each line passes through a wire hole on the bottom of the control cabinet 5 and connects to the corresponding connectors or plugs within the horizontal partition 52, protecting the connectors, plugs, and control units, and reducing or isolating the effects of splashing slurry and moisture in the construction environment. The electrical control unit 53 includes a main board 54, a load cell transmitter 55, and other electrical control devices. The measured slurry density, weight, and injection volume of each liquid are converted into electrical signals and transmitted to the main board 54, which then performs corresponding control according to the control program. The load cell transmitter 55 connects the load cell 2 to the main board 54, converting the weak and easily interfered analog signal output by the sensor into a stable, standard signal that can be transmitted over long distances. The pneumatic control unit 58 includes pneumatic control devices such as solenoid valve 56. Solenoid valve 56 controls the extension and retraction of cylinder 42 according to the instructions of main board 54, injecting raw slurry or returned slurry into slurry mixing tank 1 or sewage discharge funnel 41.

[0039] Preferably, the upper part of the control cabinet 5 is divided into two sides by a vertical partition 57 in the middle, with the electrical control unit 53 arranged on one side and the pneumatic control unit 58 arranged on the other side. This arrangement can prevent moisture and other substances generated during the use of the pneumatic circuit from corroding the components and causing adverse effects such as short circuits in the electrical control unit.

[0040] Example 7: Based on the above examples, this example provides a control method for intelligent slurry preparation, including a calibration stage, a slurry preparation stage, a slurry replenishment stage, and a slurry adjustment stage. In the slurry preparation stage, the slurry replenishment stage, and the slurry adjustment stage, the required volumes of raw slurry, returned slurry, and clean water are calculated based on the slurry volume and density set in the slurry preparation tank 1 and the volume and density of the remaining slurry in the tank. The injection amounts of raw slurry, returned slurry, and clean water are adjusted according to the slurry density and mass in the slurry preparation tank 1.

[0041] Specifically, during the calibration phase, zero-point calibration and full-scale calibration are performed on the mixing tank 1 and the return tank 4, respectively. For zero-point calibration of the mixing tank 1, the liquid inside is drained, its mass is measured, and zero-point calibration is performed to eliminate systematic errors. For full-scale calibration of the mixing tank 1, the tank is first filled with clean water, and then the water is continuously pumped out for a certain period of time. The mass change and the cumulative volume of the flow meter are measured and calculated to calibrate the system proportionality coefficient of the weighing sensor 2 and the flow meter, thereby establishing an accurate mass-volume conversion relationship and laying the foundation for subsequent accurate calculation of the mixed slurry weight. For zero-point calibration of the return tank 4, the liquid inside is drained, and density zero-point calibration is performed. For full-scale calibration of the return tank 4, the tank is filled with water, its density is measured, and the sensor readings are calibrated. By performing zero-point calibration and full-scale calibration on the mixing tank and return tank respectively during the calibration stage, the measurement errors of each sensor can be eliminated, the accuracy of measurement can be improved, and the starting point of the mixing ratio accuracy can be avoided due to the lack of automatic calibration of the sensors.

[0042] During the slurry preparation stage: Based on the density and volume of the prepared slurry, as well as the density of the slurry and the density of the clean water, calculate the required slurry volume (including the original slurry volume and the returned slurry volume) and the clean water volume. Based on the valve opening degree, calculate the opening time for injection. After injection, it is necessary to determine whether the density and weight of the prepared slurry meet the requirements. If not, recalculate each injection amount until the requirements are met.

[0043] During the grouting stage: Based on the density and volume of the prepared grout, as well as the density of the grout and the density of the clean water, plus the volume and density of the remaining grout in grouting tank 1, calculate the required grout volume (including the original grout volume and the returned grout volume) and clean water volume. Based on the valve opening degree, calculate the opening time for grouting. After grouting, it is necessary to determine whether the density and weight of the prepared grout meet the requirements. If not, recalculate the grouting amount until the requirements are met.

[0044] Slurry preparation stage: Similarly, based on the density and volume of the prepared slurry, as well as the density of the slurry and the density of the clean water, plus the volume and density of the remaining slurry in slurry tank 1, calculate the required slurry volume (including the original slurry volume and the returned slurry volume) and clean water volume. Based on the valve opening degree, calculate the opening time for injection. After injection, it is necessary to determine whether the density and weight of the prepared slurry meet the requirements. If not, recalculate the injection amount until the requirements are met.

[0045] Therefore, the automation and intelligence levels are significantly improved through the above control methods, and the operation is simplified. Through the four-stage control method (calibration, mixing, replenishing, and changing the pulp), the complex mixing process is programmed and automated, realizing staged intelligent control. Users only need to set the target parameters, and the system can automatically complete the entire process from calibration to mixing, maintenance, and adjustment, realizing dynamic and rapid replenishment and changing of the pulp. This greatly reduces the dependence on the operator's experience, simplifies control, and solves the problems of low operating efficiency, low mixing efficiency, and inability to achieve rapid and accurate switching of working conditions.

[0046] Based on the above embodiments, this embodiment provides a system parameter estimation method for intelligent slurry preparation. By establishing the correspondence between multiple sets of estimated system parameters and the required slurry density, more accurate system parameters can be set in advance, reducing initial system parameter errors, improving the accuracy of the mixed slurry after preparation, and increasing the proportioning efficiency.

[0047] Specifically, the system parameters to be estimated are set as follows: water injection time, water injection flow rate, raw slurry injection time, raw slurry injection flow rate, and raw slurry density; simulated slurry preparation is performed; multiple sets of system parameters are calculated based on the simulated slurry preparation calculation model, and the correspondence between system parameters and prepared slurry density is established.

[0048] The calculation model for simulating pulp preparation is as follows: Q1 T1_n+Q2 C0 T2_n-Q3_n C T3_n+Q4_n Cf + MassStart_n = MassEnd_n; In the calculation model, Q1 is the flow rate of clean water injection, T1_n is the time of clean water injection, Q2 is the flow rate of raw slurry injection, C0 is the density of raw slurry, T2_n is the time of raw slurry injection, Q3_n is the average injection rate, C is the density of the prepared slurry in the mixing tank, T3_n is the injection period time, Q4_n is the average return slurry flow rate, Cf is the average return slurry density, MassStart_n is the mass of slurry in mixing tank 1 at the start of injection, and MassEnd_n is the mass of slurry in mixing tank 1 after injection.

[0049] Among them, Q1 T1_n represents the mass of clean water injected into mixing tank 1 within T1_n; Q2 C0 T2_n represents the mass of raw slurry injected into slurry mixing tank 1 within T2_n; the average injection rate Q3_n is the volume of slurry stably injected into a unit length (or area, volume) of formation per unit time; Q3_n C T3_n represents the mass of slurry with density C injected into the formation within a time period T3_n after the slurry preparation in slurry mixing tank 1 is completed; Q4_n Cf represents the mass of return slurry injected into the slurry mixing tank 1, where Q4_n already includes the time for injection of return slurry.

[0050] The simulated pulp preparation process is as follows: Inject clean water, raw slurry, and returned slurry into slurry mixing tank 1 to mix the slurry. After the slurry is mixed, inject it into the formation.

[0051] In the simulated pulp preparation process, data needs to be acquired step by step: Step (a): Obtain no less than 3 sets of measurable data during the simulated slurry preparation process. Each set of data includes the following data: water injection time T1_n, initial raw slurry density C0_INT, raw slurry injection time T2_n, average injection rate Q3_n, injection period time T3_n, average return slurry flow rate Q4_n, average return slurry density Cf, slurry mass in slurry tank 1 at the start of injection MassStart_n, and slurry mass in slurry tank 1 at the end of injection MassEnd_n.

[0052] Substitute the acquired data set into the calculation model, where the initial raw slurry density C0_INT is substituted into the raw slurry density C0 in the calculation model to solve for the water injection flow rate Q1, the raw slurry injection flow rate Q2, and the configured slurry density C.

[0053] Step (b): Obtain another set of measurement data during the simulated slurry preparation process: water injection time T1_n, raw slurry injection time T2_n, average injection rate Q3_n, injection period time T3_n, average return slurry flow rate Q4_n, average return slurry density Cf, slurry mass in slurry tank 1 at the start of injection MassStart_n and slurry mass in slurry tank 1 after injection MassEnd_n, and combine them with the previously obtained water injection flow rate Q1, raw slurry injection flow rate Q2 and prepared slurry density C.

[0054] Substitute the set of measurement data and the solved data back into the calculation model to obtain the original slurry density C0. This original slurry density C0 is not the initial original slurry density C0_INT, but is obtained by substituting the measurement data obtained in step (b) with the water injection flow rate Q1, the original slurry injection flow rate Q2 and the configured slurry density C obtained in step (a) back into the calculation model.

[0055] Finally, record the water injection time T1_n and slurry injection time T2_n obtained in step (b), the water injection flow rate Q1, slurry injection flow rate Q2, and slurry density C obtained in step (a), and the slurry density C0 obtained in step (b). Then, a set of system parameters and slurry density correspondences can be established.

[0056] By changing the flow rate of clean water (Q1) and the flow rate of raw slurry (Q2) and repeatedly simulating the slurry mixing process, multiple sets of corresponding relationships can be obtained. Before the actual slurry mixing, the parameters of each system can be preset based on the data in the corresponding relationships, reducing the initial system parameter error, improving the accuracy of the mixed slurry after mixing, and increasing the mixing efficiency.

[0057] The above embodiments merely illustrate specific implementation methods of this application, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of protection of this application. It should be noted that those skilled in the art can make several modifications and improvements without departing from the concept of the technical solution of this application, and these all fall within the scope of protection of this application.

Claims

1. An intelligent pulp mixing and weighing device, characterized in that: The slurry mixing tank (1) includes slurry and water. The slurry mixing tank (1) is equipped with a sensor that measures the density and weight of the slurry mixed in the tank and can adjust the amount of slurry and water injected according to the measurement results.

2. The intelligent pulp mixing and weighing device according to claim 1, characterized in that: The mixing tank (1) is equipped with a stirring device, which includes a motor (11) and a stirring shaft (12). The motor (11) is fixed on the mounting bracket (14) at the opening of the mixing tank (1). The stirring shaft (12) is connected to the output shaft of the motor (11) and extends vertically into the tank from the center of the opening. The stirring shaft (12) is provided with inclined stirring blades.

3. The intelligent pulp mixing and weighing device according to claim 1, characterized in that: Pressure sensors are installed at different height positions inside the slurry mixing tank (1), and the density and volume of the slurry can be calculated based on the pressure difference between the two pressure sensors. The weight of the slurry mixing tank (1) is measured by a weighing sensor (2), and there are several weighing sensors (2) that surround and support the slurry mixing tank (1).

4. The intelligent slurry mixing and weighing device according to claim 3, characterized in that: The weighing sensor (2) is installed on the corresponding weighing column (21), and the pressure plate (15) protruding from the side wall of the mixing tank (1) is pressed on the weighing sensor (2); the bottom of all the weighing columns (21) is fixedly connected to the base (3) below the mixing tank (1); the weighing column (21) is also fixed with a protective cover (22) that can cover the weighing sensor (2).

5. The intelligent pulp mixing and weighing device according to claim 1, characterized in that: It also includes a return slurry tank (4) for recycling returned slurry, which can inject returned slurry into a mixing tank (1); the slurry includes raw slurry and returned slurry; a sludge discharge funnel (41) is also provided on the side of the return slurry tank (4), and the returned slurry in the return slurry tank (4) is injected into the mixing tank (1) or the sludge discharge funnel (41); the pipe for injecting raw slurry into the mixing tank (1) is connected to the mixing tank (1) or the sludge discharge funnel (41).

6. The intelligent pulp mixing and weighing device according to claim 1, characterized in that: It also includes a control cabinet (5), which is divided into upper and lower layers by a horizontal partition (52). The electrical control unit (53) and the pneumatic control unit (58) are arranged on the upper layer and connected to the corresponding lines through aviation plugs or quick-connectors in the horizontal partition (52). The upper layer of the control cabinet (5) is divided into two sides by a vertical partition (57). The electrical control unit (53) is arranged on one side and the pneumatic control unit (58) is arranged on the other side.

7. A method for controlling intelligent pulp mixing, characterized in that: The intelligent slurry mixing and weighing device according to any one of claims 1-6 includes a calibration stage, a slurry mixing stage, a slurry replenishment stage, and a slurry adjustment stage. In the slurry mixing stage, the slurry replenishment stage, and the slurry adjustment stage, the required volumes of raw slurry, returned slurry, and clean water are calculated based on the slurry volume and density set in the slurry mixing tank (1) and the volume and density of the remaining slurry in the tank. The injection volume of raw slurry, returned slurry, and clean water is adjusted according to the slurry density and mass in the slurry mixing tank (1).

8. The intelligent pulping control method according to claim 7, characterized in that: During the calibration stage, zero-point calibration and full-scale calibration were performed on the mixing tank (1) and the return tank (4), respectively. When the mixing tank (1) was calibrated to full scale, clean water was continuously extracted from the mixing tank (1) for a certain period of time to calculate the mass change and the cumulative volume of the flow meter.

9. A method for estimating system parameters of intelligent pulp mixing, characterized in that: For the weighing device or control method according to any one of claims 1-8, the following system parameters to be estimated are set: water injection time and flow rate, raw slurry injection time and flow rate, and raw slurry density; simulated slurry preparation is performed; multiple sets of system parameters are calculated according to the simulated slurry preparation calculation model, and the correspondence between system parameters and prepared slurry density is established.

10. The system parameter estimation method for intelligent pulp mixing according to claim 9, characterized in that: The simulation calculation model for pulp preparation is as follows: Q1 T1_n+Q2 C0 T2_n-Q3_n C T3_n+Q4_n Cf+MassStart_n=MassEnd_n; In the calculation model, Q1 is the flow rate of clean water injection, T1_n is the time of clean water injection, Q2 is the flow rate of raw slurry injection, C0 is the density of raw slurry, T2_n is the time of raw slurry injection, Q3_n is the average injection rate, C is the density of the prepared slurry, T3_n is the injection period time, Q4_n is the average return slurry flow rate, Cf is the average return slurry density, MassStart_n is the mass of slurry in the mixing tank (1) at the beginning of injection, and MassEnd_n is the mass of slurry in the mixing tank (1) after injection. Simulated slurry preparation: Inject clean water, raw slurry, and returned slurry into the slurry preparation tank (1), and add the slurry after preparation is completed; During the simulated pulp preparation process, at least three sets of measurable data are obtained: T1_n, C0_INT, T2_n, Q3_n, T3_n, Q4_n, C, MassStart_n, and MassEnd_n; Substitute the acquired data set into the calculation model for calculation, where C0_INT is the initial pulp density. Substitute C0 into the calculation model to solve for Q1, Q2 and C. Then, another set of data is obtained during the simulated slurry preparation process: T1_n, T2_n, Q3_n, T3_n, Q4_n, C, MassStart_n, and MassEnd_n. The solved Q1, Q2, and C are substituted into the calculation model to obtain C0. T1_n, T2_n, Q1, Q2, C0, and C in this set are recorded to establish a correspondence between a set of system parameters and the configured slurry density. By changing the values ​​of Q1 and Q2, the pulp mixing calculation process is repeated to establish multiple sets of corresponding relationships.

Images