Constant-power automatic speed regulation control system and control method for UHPC stirring

Abstract

The invention relates to the field of UHPC stirring machine control, in particular to a constant-power automatic speed regulation control system and method for UHPC stirring, the operation process of a UHPC stirring machine is divided into a plurality of process stages, each stage corresponds to different frequencies, rotating speeds and operation time, accurate control over the rotating speeds is achieved, and on the premise that the power is constant, the speed regulation speed of the UHPC stirring machine can be accurately controlled. The rotating speed is flexibly adjusted to meet the requirements of different stirring stages of UHPC, the mixing quality is guaranteed, efficient utilization of energy is achieved, a constant-speed stirring machine is changed into a variable-speed intelligent stirring machine through multi-section speed control of the frequency converter, energy is saved by 30% or above, and the quality and productivity of UHPC products are remarkably improved through process-level rotating speed matching.

Description

Technical Field

[0001] This invention relates to the field of UHPC mixer control, specifically a constant power automatic speed regulation control system and control method for UHPC mixers. Background Technology

[0002] UHPC mixers are core equipment for producing ultra-high performance concrete. Traditional UHPC mixers use a power frequency drive, which has the following drawbacks: 1. When the mixer is running at full speed, energy consumption is proportional to the cube of the speed, resulting in serious energy waste and high energy consumption; 2. The UHPC production process includes four stages: feeding, dispersion, homogenization, and unloading. The shear rate requirements for each stage vary greatly, but the traditional power frequency drive uses a "one-size-fits-all" constant speed operation, which has poor process adaptability and cannot meet the process requirements of different stages; 3. Because the speed cannot be adjusted according to the process stage, the single batch cycle time is long and the production efficiency is low.

[0003] Therefore, the purpose of this invention is to provide a UHPC mixer control technology that can adjust the rotation speed according to different process stages, so as to solve the pain points of the prior art.

[0004] Purpose of the invention

[0005] The purpose of this invention is to achieve precise control of the rotation speed by dividing the operation of the UHPC mixer into multiple process stages, each stage corresponding to different frequencies, rotation speeds and running times, thereby significantly improving production efficiency, reducing energy consumption and enhancing product quality stability.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] A constant power automatic speed control system for UHPC stirring includes:

[0008] The frequency converter has a rated power of 75kW, an overload capacity of 200% / 60s, and a speed regulation accuracy of 0.2%.

[0009] The input / output unit includes input terminals and output terminals. The input terminals are interfaces for receiving external control signals. The input terminals include DI1 for operation enable, DI2-DI4 for three-speed operation, and DI5 for emergency stop. The output terminal AO is used to send the real-time speed to the DCS.

[0010] The control unit is used to set multi-speed process parameters and control the frequency converter to operate according to the multi-speed process parameters. The multi-speed process parameters include at least four process stages, and each process stage corresponds to a preset frequency, speed, and running time.

[0011] Furthermore, the inverter model is Robicon H901-75KW, and the parameters are set as follows:

[0012] P0-02 = 1, terminal control is used;

[0013] P0-03 = 6, multi-speed mode is used;

[0014] Write 35, 60, 120, 50, and 15Hz to P4-00 and P4-04 respectively;

[0015] P5-00 = 2, S1-S5 correspond to DI2-DI4 binary codes.

[0016] Acceleration / deceleration time P1-05 / P1-06 = 8s, to prevent slurry from splashing due to inertia.

[0017] Specifically, DI1 is used to receive an external permission signal to enable the inverter to enter the working state; DI2-DI4 send frequency commands for different speed ranges to the inverter through binary code combinations (power-on / power-off state); DI5 is used to receive an emergency stop signal to trigger the inverter to immediately stop output; the output terminal AO is used to transmit the real-time speed signal of the mixer to the DCS system to realize speed monitoring.

[0018] Furthermore, the multi-speed process parameters specifically include:

[0019] S1 stage: The process stage is the stage of feeding aggregates and powders. The frequency converter outputs high frequency and the mixer shears at high speed to improve the uniformity of materials in a short time.

[0020] S2 stage: The process stage is the addition of water-reducing agent and water. As the viscosity of the material increases after water is added, the speed of the mixer is gradually reduced to improve the wetting efficiency, fully activate the microsilica powder, reduce the speed to exhaust air, and remove air bubbles.

[0021] S3 stage: The process stage is unloading, which further reduces the rotation speed to prevent material splashing during unloading;

[0022] S4 stage: The process stage is standby, further reducing the speed to maintain energy saving and standby.

[0023] Furthermore, the multi-speed process parameters specifically include:

[0024] S1 stage: The process stage is the aggregate and powder feeding stage, with a frequency of 35Hz. After 5 seconds of feeding, the frequency increases to 60Hz, and after 15 seconds of feeding, the frequency increases to 90Hz. At this time, the aggregate and powder feeding ends, and the frequency is increased to 120Hz and maintained for 90-180 seconds.

[0025] S2 stage: The process stage is the stage of adding water-reducing agent and water. After the start of feeding, the frequency drops to 90Hz within 15 seconds, and then drops to 50Hz after 45 seconds, and is maintained for 60-120 seconds.

[0026] S3 stage: The process stage is unloading. After 10 seconds, the frequency will be reduced from 50Hz to 35Hz and maintained for 60-90 seconds until unloading is completed.

[0027] S4 stage: The process stage is standby. After unloading, the frequency drops to 15Hz to maintain energy saving and standby. Before feeding aggregates and powders, the frequency is increased to 35Hz to enter the next cycle.

[0028] On the other hand, the present invention provides a constant power automatic speed control method for UHPC stirring, including hardware configuration, multi-speed process setting, parameter tuning and program operation steps.

[0029] A constant power automatic speed control method for UHPC stirring is as follows:

[0030] The Robicon H901-75KW frequency converter is used as the hardware configuration, with input terminals DI1-DI5 and output terminal AO connected. DI1 is the operation enable terminal, DI2-DI4 are three-speed terminals, DI5 is the emergency stop terminal, and AO is used to send the real-time speed to the DCS.

[0031] Four multi-speed process stages are set up, each corresponding to a preset frequency, speed, and running time.

[0032] Configure the inverter parameters, including terminal control, multi-speed mode, frequency of each speed, encoding method, and acceleration / deceleration time;

[0033] By utilizing the built-in PLC function of the frequency converter, the frequency and auxiliary parameters corresponding to each process stage can be set, and intelligent operation can be achieved by starting the control system.

[0034] Furthermore, the specific parameters for the multi-speed process are:

[0035] S1 stage: The process stage is the aggregate and powder feeding stage, with a frequency of 35Hz. After 5 seconds of feeding, the frequency increases to 60Hz, and after 15 seconds of feeding, the frequency increases to 90Hz. At this time, the aggregate and powder feeding ends, and the frequency is increased to 120Hz and maintained for 90-180 seconds.

[0036] S2 stage: The process stage is the stage of adding water-reducing agent and water. After the start of feeding, the frequency drops to 90Hz within 15 seconds, and then drops to 50Hz after 45 seconds, and is maintained for 60-120 seconds.

[0037] S3 stage: The process stage is unloading. After 10 seconds, the frequency will be reduced from 50Hz to 35Hz and maintained for 60-90 seconds until unloading is completed.

[0038] S4 stage: The process stage is standby. After unloading, the frequency drops to 15Hz to maintain energy saving and standby. Before feeding aggregates and powders, the frequency is increased to 35Hz to enter the next cycle.

[0039] Furthermore, the inverter parameters are set as follows:

[0040] P0-02=1 indicates terminal control mode;

[0041] P0-03 = 6 indicates multi-speed mode;

[0042] P4-00 to P4-04 are set to 35, 60, 120, 50, and 15 Hz respectively (corresponding to the reference frequencies of each stage);

[0043] P5-00 = 2 (S1-S5 corresponds to DI2-DI4 binary encoding);

[0044] Acceleration / deceleration time P1-05 / P1-06 = 8s (to prevent slurry inertial splashing).

[0045] The beneficial effects of this invention are:

[0046] Through multi-speed control, the single-batch cycle time was reduced from 12 minutes to 9 minutes, increasing production capacity by 33%. Furthermore, precise matching of shear energy to each process stage reduced the UHPC 28d strength fluctuation from ±3.5MPa to ±1.2MPa. The measured average power decreased from 35kW to 23kW, saving 35% on electricity. The soft-start current was ≤1.2Ie, peak impact was reduced by 80%, and motor temperature rise was reduced by 12K, extending motor life. Simultaneously, the inverter incorporates multiple protection functions to prevent motor burnout accidents.

[0047] This invention allows for flexible speed adjustment to adapt to the different mixing stages of a UHPC while maintaining constant power, ensuring mixing quality and achieving efficient energy utilization. The multi-speed control of the frequency converter transforms the "constant-speed mixer" into a "variable-speed intelligent mixer," saving more than 30% in energy. Furthermore, the "process-level" speed matching significantly improves the quality and capacity of UHPC products. This solution can be replicated for all batch and flow mixers, providing a low-investment, high-output upgrade path for industries such as building materials, chemicals, and food. Detailed Implementation

[0048] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0049] A constant power automatic speed control system for UHPC stirring includes:

[0050] The frequency converter, model Robicon H901-75KW, has a rated power of 75kW, an overload capacity of 200% / 60s, and a speed regulation accuracy of 0.2%.

[0051] The input / output unit includes input terminals and output terminals. The input terminals are interfaces for receiving external control signals. The input terminals include DI1 for operation enable, DI2-DI4 for three-speed operation, and DI5 for emergency stop. The output terminal AO is used to send the real-time speed to the DCS.

[0052] The control unit is used to set multi-speed process parameters and control the frequency converter to operate according to the multi-speed process parameters. The multi-speed process parameters include at least four process stages, and each process stage corresponds to a preset frequency, speed, and running time.

[0053] Among them, DI1 operation enable is the control node for starting and running the entire variable frequency multi-speed control system. When an external control signal energizes the DI1 operation enable terminal, it sends an instruction to the frequency converter to enable operation. At this time, the frequency converter is in a working state, and subsequent three-speed control instructions and other related operation instructions can be received and executed by the frequency converter.

[0054] The DI-DI4 three-speed terminal is the input part for realizing multi-speed control of the UHPC mixer. These three terminals transmit different frequency commands to the frequency converter through different power-on combinations.

[0055] The DI5 emergency stop terminal is used to trigger the system to stop operating in an emergency, playing a role in ensuring system safety. Once an emergency occurs during production, such as a sudden equipment failure or an operator discovering a safety hazard, the relevant triggering device will de-energize the DI5 terminal. After the DI5 terminal is de-energized, the frequency converter will respond immediately and quickly stop the current operating command, causing the motor of the UHPC mixer to stop running, thereby avoiding potentially more serious safety accidents or equipment damage.

[0056] As a preferred embodiment, the above-mentioned multi-speed process parameters are specifically as follows:

[0057] S1 stage: The process stage is the aggregate and powder feeding stage, with a frequency of 35Hz. After 5 seconds of feeding, the frequency increases to 60Hz, and after 15 seconds of feeding, the frequency increases to 90Hz. At this time, the aggregate and powder feeding ends, and the frequency is increased to 120Hz and maintained for 90-180 seconds.

[0058] S2 stage: The process stage is the stage of adding water-reducing agent and water. After the start of feeding, the frequency drops to 90Hz within 15 seconds, and then drops to 50Hz after 45 seconds, and is maintained for 60-120 seconds.

[0059] S3 stage: The process stage is unloading. After 10 seconds, the frequency will be reduced from 50Hz to 35Hz and maintained for 60-90 seconds until unloading is completed.

[0060] S4 stage: The process stage is standby. After unloading, the frequency drops to 15Hz to maintain energy saving and standby. Before feeding aggregates and powders, the frequency is increased to 35Hz to enter the next cycle.

[0061] A constant power automatic speed control method for a UHPC stirrer includes:

[0062] The Robicon H901-75KW frequency converter is used as the hardware configuration, with input terminals DI1-DI5 and output terminal AO connected. DI1 is the operation enable terminal, DI2-DI4 are three-speed terminals, DI5 is the emergency stop terminal, and AO is used to send the real-time speed to the DCS.

[0063] Four multi-speed process stages are set up, each corresponding to a preset frequency, speed, and running time.

[0064] Configure the inverter parameters, including terminal control, multi-speed mode, frequency of each speed, encoding method, and acceleration / deceleration time;

[0065] By utilizing the built-in PLC function of the frequency converter, the frequency and auxiliary parameters corresponding to each process stage can be set, and intelligent operation can be achieved by starting the control system.

[0066] Specifically, the four multi-speed process stages include:

[0067] S1 stage: The process stage is the aggregate and powder feeding stage, with a frequency of 35Hz. After 5 seconds of feeding, the frequency rises to 60Hz, and after 15 seconds of feeding, the frequency rises to 90Hz. At this time, the aggregate and powder feeding ends, and the frequency is raised to 120Hz and maintained for 90-180 seconds. In a short time, high frequency output and high speed shearing are achieved to improve the uniformity of materials.

[0068] S2 stage: The process stage is the addition of water-reducing agent and water. After the start of feeding, the frequency drops to 90Hz within 15 seconds, and then drops to 50Hz after 45 seconds, and is maintained for 60-120 seconds. This is achieved by reducing the rotation speed, improving wetting efficiency, activating the microsilica powder, and removing air bubbles.

[0069] S3 stage: The process stage is unloading. After 10 seconds, the frequency will be reduced from 50Hz to 35Hz and maintained for 60-90 seconds until unloading is completed. Low-speed operation prevents material splashing.

[0070] S4 stage: The process stage is standby. After unloading, the frequency drops to 15Hz to maintain energy saving and standby. Before feeding aggregates and powders, the frequency is increased to 35Hz to enter the next cycle.

[0071] The present invention will be described in detail below with reference to specific parameters:

[0072] Hardware configuration:

[0073] The Robicon H901-75KW frequency converter is selected. Input terminal DI1 is connected to the external operation enable switch, DI2-DI4 are connected to the PLC output relay (control binary code), DI5 is connected to the emergency stop button, and AO is connected to the DCS AI module.

[0074] The inverter parameters are set as follows:

[0075] Control modes: P0-02 = 1 (terminal control), P0-03 = 6 (multi-speed mode);

[0076] Frequency parameters: P4-00 = 35Hz, P4-01 = 60Hz, P4-02 = 120Hz, P4-03 = 50Hz, P4-04 = 15Hz;

[0077] Encoding method: P5-00 = 2 (the binary combination of DI2-DI4 corresponds to S1-S5);

[0078] Dynamic parameters: acceleration / deceleration time P1-05 / P1-06 = 8s, to avoid slurry splashing due to inertia.

[0079] The operating logic is as follows:

[0080] DI1 is enabled, and the system enters standby mode (S4 stage, 15Hz);

[0081] Triggering S1 stage: DI2-DI4 output "001" code, and the frequency increases in steps from 35 to 60 to 90 to 120Hz, which is used for high-speed shearing of aggregates and powders;

[0082] Switching to S2 stage: The encoding is switched to "010", and the frequency is gradually reduced to 50Hz to adapt to changes in material viscosity;

[0083] Switching to S3 stage: The encoding is switched to "011", the frequency is reduced to 35Hz, and the material is unloaded at low speed;

[0084] Returning to S4 stage: the encoding is switched to "100", the frequency drops to 15Hz to standby, and automatically rises back to 35Hz before the next cycle.

[0085] Example 1

[0086] The UHPC mixer variable frequency multi-speed control method described in this invention is as follows:

[0087] Hardware configuration: Robicon H901-75KW frequency converter is selected. Input terminal DI1 is for operation enable, DI2-DI4 are three-speed terminals, DI5 is for emergency stop, and output terminal AO sends the real-time speed to DCS.

[0088] Multi-speed process parameter settings:

[0089] S1 stage (aggregate and powder feeding stage): The frequency is initially 35Hz, then increases to 60Hz after 5 seconds of feeding, then to 90Hz after 15 seconds, and finally increases to 120Hz after the aggregate and powder feeding is completed. This frequency is maintained for 160 seconds to achieve high-speed shearing and improve material uniformity.

[0090] S2 stage (water-reducing agent and water stage): The frequency drops to 90Hz within 15 seconds after the start of feeding, then drops to 50Hz after 45 seconds, and is maintained for 80 seconds. The rotation speed is reduced to improve wetting efficiency, activate microsilica powder and remove air bubbles.

[0091] S3 stage (unloading): After 10 seconds, the frequency drops from 50Hz to 35Hz and is maintained for 70 seconds until unloading is completed. Low-speed operation prevents material splashing.

[0092] S4 stage (standby): After unloading, the frequency drops to 15Hz to save energy and standby. Before feeding aggregates and powders, it rises to 35Hz to enter the next cycle.

[0093] Inverter parameter settings: P0-02 = 1 (terminal control), P0-03 = 6 (multi-speed mode), P4-00 to P4-04 are written with 35, 60, 120, 50, and 15Hz respectively, P5-00 = 2 (S1-S5 correspond to DI2-DI4 binary codes), acceleration / deceleration time P1-05 / P1-06 = 8s.

[0094] Operation status: Utilizing the built-in PLC function of the frequency converter, intelligent operation is achieved by starting the control system.

[0095] Comparative Example 1

[0096] The conventional UHPC mixer is driven by industrial frequency, as follows:

[0097] Hardware configuration: It adopts the mains frequency drive method, without frequency converter, and the motor is directly connected to the mains frequency power supply to run.

[0098] Operating mode: The mixer always runs at a fixed full speed. The speed does not change during all process stages, including feeding aggregates, powders, water-reducing agents and water, unloading, and standby.

[0099] Operating status: Throughout the process, the motor runs continuously at the industrial frequency speed, and the speed cannot be adjusted according to the needs of different process stages.

[0100] The results data are as follows:

[0101] Comparative Example 1: The single-batch cycle time is 12 minutes, resulting in low production capacity; the UHPC 28d strength fluctuation is ±3.5MPa, indicating poor stability; the average power during operation is 35kW, resulting in high energy consumption; the current surge during startup is large, the peak current is high, the motor temperature rise is significant, and the equipment lifespan is affected; there is a lack of targeted protection mechanisms, posing a risk of motor burnout.

[0102] Example 1: Single batch cycle time is 9 minutes, increasing production capacity by 33%; UHPC 28d intensity fluctuation is ±1.2MPa; measured average power is 23kW, saving 35% of power compared to the mains frequency; soft start current ≤1.2Ie, peak impact reduced by 80%, motor temperature rise reduced by 12K, and lifespan extended; the frequency converter has multiple built-in protection functions to avoid motor burnout accidents.

[0103] The above description is merely an embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural or procedural transformations made based on the content of the present invention specification, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of the present invention.

Claims

1. A constant power automatic speed control system for UHPC stirring, characterized in that, include: The frequency converter, model Robicon H901-75KW, has a rated power of 75kW, an overload capacity of 200% / 60s, and a speed regulation accuracy of 0.2%. The input / output unit includes input terminals and output terminals. The input terminals are interfaces for receiving external control signals. The input terminals include DI1 for operation enable, DI2-DI4 for three-speed operation, and DI5 for emergency stop. The output terminal AO is used to send the real-time speed to the DCS. The control unit is used to set multi-speed process parameters and control the frequency converter to operate according to the multi-speed process parameters. The multi-speed process parameters include at least four process stages, and each process stage corresponds to a preset frequency, speed, and running time.

2. The constant power automatic speed control system for UHPC stirring according to claim 1, characterized in that, The inverter parameters are set as follows: P0-02 = 1, terminal control is used; P0-03 = 6, multi-speed mode is used; Write 35, 60, 120, 50, and 15Hz to P4-00 and P4-04 respectively; P5-00 = 2, S1-S5 correspond to DI2-DI4 binary codes. Acceleration / deceleration time P1-05 / P1-06 = 8s, to prevent slurry from splashing due to inertia.

3. The constant power automatic speed control system for UHPC stirring according to claim 1, characterized in that, The multi-speed process parameters specifically include: S1 stage: The process stage is the aggregate and powder feeding stage, with a frequency of 35Hz. After 5 seconds of feeding, the frequency increases to 60Hz, and after 15 seconds of feeding, the frequency increases to 90Hz. At this time, the aggregate and powder feeding ends, and the frequency is increased to 120Hz and maintained for 90-180 seconds. S2 stage: The process stage is the stage of adding water-reducing agent and water. After the start of feeding, the frequency drops to 90Hz within 15 seconds, and then drops to 50Hz after 45 seconds, and is maintained for 60-120 seconds. S3 stage: The process stage is unloading. After 10 seconds, the frequency will be reduced from 50Hz to 35Hz and maintained for 60-90 seconds until unloading is completed. S4 stage: The process stage is standby. After unloading, the frequency drops to 15Hz to maintain energy saving and standby. Before feeding aggregates and powders, the frequency is increased to 35Hz to enter the next cycle.

4. The constant power automatic speed control system for UHPC stirring according to claim 1, characterized in that, The multi-speed process parameters specifically include: S1 stage: The process stage is the aggregate and powder feeding stage. The frequency is initially 35Hz, then increases to 60Hz after 5 seconds of feeding, then to 90Hz after 15 seconds, and finally increases to 120Hz after the aggregate and powder feeding is completed. This frequency is maintained for 160 seconds to achieve high-speed shearing and improve material uniformity. S2 stage: The process stage is the addition of water-reducing agent and water. After the start of feeding, the frequency drops to 90Hz within 15 seconds, then drops to 50Hz after 45 seconds, and is maintained for 80 seconds. The rotation speed is reduced to improve wetting efficiency, activate microsilica powder and remove air bubbles. S3 stage: The process stage is unloading. After 10 seconds, the frequency drops from 50Hz to 35Hz and is maintained for 70 seconds until unloading is completed. Low-speed operation prevents material splashing. S4 stage: The process stage is standby. After unloading, the frequency drops to 15Hz for energy saving and standby. Before feeding aggregate and powder, it rises to 35Hz to enter the next cycle.

5. A constant power automatic speed control method for UHPC stirring according to any one of claims 1-4, comprising hardware configuration, multi-speed process setting, parameter setting, and program operation steps, characterized in that: The Robicon H901-75KW frequency converter is used as the hardware configuration, with input terminals DI1-DI5 and output terminal AO connected. DI1 is the operation enable terminal, DI2-DI4 are three-speed terminals, DI5 is the emergency stop terminal, and AO is used to send the real-time speed to the DCS. Four multi-speed process stages are set up, each corresponding to a preset frequency, speed, and running time. Configure the inverter parameters, including terminal control, multi-speed mode, frequency of each speed, encoding method, and acceleration / deceleration time; By utilizing the built-in PLC function of the frequency converter, the frequency and auxiliary parameters corresponding to each process stage can be set, and intelligent operation can be achieved by starting the control system.