Method for predicting mechanical heat and method for controlling temperature of machine outlet of concrete mixing plant

Abstract

The invention discloses a method for predicting mechanical heat and a method for controlling the temperature of a machine outlet of a concrete mixing plant, and relates to the technical field of concrete production equipment. The method comprises the following steps: acquiring a first target stirring duration of a concrete stirring process; the method is based on a predetermined motor heat loss prediction model, a stirring heat prediction model and a shearing heat prediction model. According to the first target stirring duration, determining a motor heat loss prediction value within the first target stirring duration, a stirring heat prediction value generated by sliding friction and collision between stirring machine blades and concrete, and a shear heat prediction value generated by friction between aggregate in the concrete and slurry; and based on a predetermined mechanical heat prediction model, according to the motor heat loss prediction value, the stirring heat prediction value and the shear heat prediction value, determining a mechanical heat prediction value within the first target stirring duration. The accuracy of the mechanical heat prediction result can be improved.

Description

Technical Field

[0001] This application relates to the field of concrete production equipment technology, specifically to a method for predicting mechanical heat and a method for controlling the temperature at the outlet of a concrete mixing plant. Background Technology

[0002] In existing technologies, the mechanical heat during concrete mixing is typically predicted using empirical formulas, usually Q. j =42Pt / V, where P is the mixer power (kW), t is the mixing time (min), and V is the mixer discharge volume (m³). In this empirical formula, mechanical heat is only related to the mixer power, mixing time, and discharge volume. However, in actual concrete mixing, in addition to the above factors, other factors also affect mechanical heat, such as mixer blade parameters. Therefore, the mechanical heat predicted by the empirical formula in the prior art is inaccurate; that is, the existing technology has the problem of inaccurate prediction results for mechanical heat. Summary of the Invention

[0003] The purpose of this application is to provide a method for predicting mechanical heat during concrete mixing, a method for controlling the outlet temperature of a concrete mixing plant, a device for predicting mechanical heat during concrete mixing, a device for controlling the outlet temperature of a concrete mixing plant, a concrete mixing plant, and a machine-readable storage medium, in order to solve the problem of inaccurate prediction results of mechanical heat in the prior art.

[0004] To achieve the above objectives, the first aspect of this application provides a method for predicting the mechanical heat during concrete mixing, the method comprising: To obtain the first target mixing time for the concrete mixing process; Based on the predetermined motor heat loss prediction model, mixing heat prediction model and shear heat prediction model, the predicted values ​​of motor heat loss, mixing heat generated by sliding friction and collision between mixer blades and concrete and shear heat generated by friction between aggregates and slurry in concrete are determined according to the first target mixing time. Among them, the motor heat loss prediction model, mixing heat prediction model and shear heat prediction model are all models with mixing time as the variable. Based on a predetermined mechanical heat prediction model, the mechanical heat prediction value within the first target stirring time is determined according to the predicted values ​​of motor heat loss, stirring heat, and shear heat. The mechanical heat prediction model characterizes the nonlinear relationship between mechanical heat and motor heat loss, stirring heat, and shear heat.

[0005] In this embodiment of the application, the process of determining the mechanical heat prediction model includes: acquiring the concrete temperature rise in the mixer under different actual mixing times detected by the temperature detection device; determining the actual mechanical heat under different actual mixing times based on the concrete temperature rise, the preset concrete material mix ratio, and the preset concrete specific heat capacity; and obtaining the mechanical heat prediction model based on the nonlinear regression analysis method, the actual mechanical heat under different actual mixing times, multiple actual mixing times, the motor heat loss prediction model, the mixing heat prediction model, and the shear heat prediction model.

[0006] In this embodiment of the application, the motor heat loss prediction model satisfies the following formula: Q 电机 =P×(1-η) ×t Among them, Q 电机 P is the predicted value of motor heat loss, η is the preset rated power of the motor, t is the preset motor efficiency, and t is the stirring time. The heat prediction model for stirring satisfies the following formula: Q 搅拌 =k×ρ×N 3 ×D 5 ×t Among them, Q 搅拌 ρ is the predicted value of mixing heat, k is the preset resistance coefficient, ρ is the preset concrete density, N is the preset mixing shaft speed of the mixer, D is the preset mixer blade radius, and t is the mixing time. The shear heat prediction model satisfies the following formula: Q 剪切 =μ×γ 2 ×V×t Among them, Q 剪切 γ is the predicted shear heat value, μ is the preset effective viscosity of concrete, γ is the preset average shear rate, V is the preset concrete volume, and t is the mixing time.

[0007] A second aspect of this application provides a method for controlling the temperature at the outlet of a concrete mixing plant, the method comprising: The initial control temperature of the target concrete material entering the machine, the initial control amount of ice added to the concrete mixing plant's ice system, the second target mixing time of the concrete mixing plant's mixer, and the target outlet temperature of the concrete are obtained. The mechanical heat prediction value within the second target mixing time is determined based on the second target mixing time, wherein the mechanical heat prediction value is predicted according to the above-mentioned method for predicting mechanical heat during concrete mixing. Based on the predetermined outlet temperature prediction model, the initial outlet temperature prediction value is determined according to the initial controlled inlet temperature, the initial controlled amount of ice added to the concrete, and the mechanical heat prediction value within the second target mixing time. The outlet temperature prediction model characterizes the relationship between the outlet temperature and the controlled inlet temperature of the concrete material, the controlled amount of ice added to the concrete by the ice adding system, and the mechanical heat during the concrete mixing process. If the temperature deviation between the initial predicted outlet temperature and the target outlet temperature exceeds the preset temperature deviation range, adjust the initial controlled inlet temperature and the initial controlled concrete ice addition amount until the temperature deviation is within the preset temperature deviation range, so as to obtain the target controlled inlet temperature of the target concrete material and the target controlled concrete ice addition amount of the ice addition system. The operation of the concrete mixing plant is controlled by adjusting the target inlet temperature and the target amount of ice added to the concrete.

[0008] In this embodiment of the application, the control method further includes: when the temperature deviation between the initial predicted outlet temperature and the target outlet temperature is within a preset temperature deviation range, controlling the operation of the concrete mixing plant according to the initial controlled inlet temperature and the initial controlled amount of ice added to the concrete.

[0009] A third aspect of this application provides an apparatus for predicting mechanical heat during concrete mixing, the apparatus comprising: a memory configured to store instructions; and a processor configured to retrieve instructions from the memory and, when executing the instructions, to implement the method described above for predicting mechanical heat during concrete mixing.

[0010] The fourth aspect of this application provides a control device for the outlet temperature of a concrete mixing plant. The control device includes: a memory configured to store instructions; and a processor configured to retrieve instructions from the memory and, when executing the instructions, to implement the control method for the outlet temperature of a concrete mixing plant as described above.

[0011] The fifth aspect of this application provides a concrete mixing plant, comprising: the device described above for predicting mechanical heat during the concrete mixing process; or the device described above for controlling the temperature at the outlet of the concrete mixing plant.

[0012] A sixth aspect of this application provides a machine-readable storage medium storing instructions for causing a machine to perform the method described above for predicting mechanical heat during concrete mixing.

[0013] A seventh aspect of this application provides a machine-readable storage medium storing instructions for causing a machine to perform the control method described above for the outlet temperature of a concrete mixing plant.

[0014] The above technical solution, through a pre-determined motor heat loss prediction model, stirring heat prediction model, shear heat prediction model, and a first target stirring time, can obtain relatively accurate predicted values ​​for motor heat loss, stirring heat, and shear heat within the first target stirring time. Based on a pre-determined mechanical heat prediction model that characterizes the nonlinear relationship between mechanical heat and motor heat loss, stirring heat, and shear heat, and according to the predicted values ​​for motor heat loss, stirring heat, and shear heat within the first target stirring time, a relatively accurate predicted value for mechanical heat within the first target stirring time can be obtained. This process not only considers that mechanical heat mainly consists of motor heat loss, stirring heat, and shear heat (i.e., it considers the influence of factors such as motor-related parameters, mixer-related parameters, and concrete material-related parameters on mechanical heat during the stirring process), but also considers the nonlinear relationship between mechanical heat and motor heat loss, stirring heat, and shear heat. This avoids the limitations of existing technologies that predict mechanical heat based on only a few influencing factors, enabling a more comprehensive and multi-dimensional accurate prediction of mechanical heat, thus improving the accuracy of mechanical heat prediction results.

[0015] Other features and advantages of the embodiments of this application will be described in detail in the following detailed description section. Attached Figure Description

[0016] The accompanying drawings are provided to further illustrate the embodiments of this application and form part of the specification. They are used together with the following detailed description to explain the embodiments of this application, but do not constitute a limitation on the embodiments of this application. In the drawings: Figure 1 The illustration shows a schematic flow diagram of a method for predicting mechanical heat during concrete mixing according to an embodiment of this application. Figure 2 The illustration shows a schematic flowchart of a method for controlling the outlet temperature of a concrete mixing plant according to an embodiment of this application. Figure 3 The schematic diagram illustrates a structural schematic of a concrete mixing plant according to an embodiment of this application. Detailed Implementation

[0017] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are only for illustration and explanation of the embodiments of this application and are not intended to limit the embodiments of this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0018] It should be noted that the acquisition, transmission, storage, use, and processing of data in the technical solution of this application all comply with relevant laws and regulations. In the embodiments of this application, certain existing industry solutions such as software, components, and models may be mentioned. These should be considered exemplary, intended only to illustrate the feasibility of implementing the technical solution of this application, and do not imply that the applicant has already used or necessarily used such solutions.

[0019] It should be noted that if the embodiments of this application involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicators will also change accordingly.

[0020] Furthermore, if the embodiments of this application involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, features defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the technical solutions of various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. If the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed in this application.

[0021] Figure 1 The illustration schematically shows a flow diagram of a method for predicting the mechanical heat during concrete mixing according to an embodiment of this application. Figure 1 As shown in the illustration, this application provides a method for predicting the mechanical heat during concrete mixing. Taking the application of this method to a processor as an example, the method may include the following steps: Step S102: Obtain the first target mixing time for the concrete mixing process.

[0022] Step S104: Based on the predetermined motor heat loss prediction model, mixing heat prediction model, and shear heat prediction model, determine the predicted values ​​of motor heat loss, mixing heat generated by sliding friction and collision between mixer blades and concrete, and shear heat generated by friction between aggregates and slurry within the first target mixing time according to the first target mixing time. Among them, the motor heat loss prediction model, mixing heat prediction model, and shear heat prediction model are all models with mixing time as the variable.

[0023] Step S106: Based on the predetermined mechanical heat prediction model, determine the mechanical heat prediction value within the first target stirring time according to the predicted values ​​of motor heat loss, stirring heat, and shear heat. The mechanical heat prediction model characterizes the nonlinear relationship between mechanical heat and motor heat loss, stirring heat, and shear heat.

[0024] It can be understood that the first target mixing time is the desired mixing time for the concrete mixing process when it is necessary to predict the mechanical heat during concrete mixing. The motor heat loss prediction model is a calculation model used to predict the heat loss of the motor during concrete mixing. It can be determined in advance through experiments. The heat loss is related to motor parameters such as motor power (usually a constant) and mixing time. The mixing heat prediction model is a calculation model used to predict the heat generated by the sliding friction and collision between the mixer blades and concrete during concrete mixing. It can be determined in advance through experiments. The mixing heat is related to mixer parameters such as mixer blade parameters (usually a constant), concrete material parameters such as raw material ratio (usually a constant), and mixing time. The shear heat prediction model is a calculation model used to predict the heat generated by the friction between aggregates and the slurry in the concrete during concrete mixing. It can be determined in advance through experiments. The shear heat is related to concrete material parameters such as raw material ratio (usually a constant) and mixing time. Understandably, the motor heat loss prediction model, the mixing heat prediction model, and the shear heat prediction model are all models that use mixing time (i.e., time) as a variable. That is, motor heat loss, mixing heat, and shear heat all change with the mixing time. The mechanical heat prediction model is a calculation model used to predict the mechanical heat during the concrete mixing process. It consists of three parts: motor heat loss, mixing heat, and shear heat. Among them, the mechanical heat has a non-linear relationship with motor heat loss, mixing heat, and shear heat. The mechanical heat prediction model can be determined in advance through non-linear regression analysis.

[0025] Specifically, the processor can obtain the first target mixing time of the concrete mixing process, and based on the pre-determined motor heat loss prediction model, mixing heat prediction model, and shear heat prediction model, input the first target mixing time into the motor heat loss prediction model, mixing heat prediction model, and shear heat prediction model, thereby obtaining the predicted values ​​of motor heat loss, mixing heat, and shear heat within the first target mixing time output by the motor heat loss prediction model, mixing heat prediction model, and shear heat prediction model, respectively. Further, based on the pre-determined mechanical heat prediction model, the predicted values ​​of motor heat loss, mixing heat, and shear heat are input into the mechanical heat prediction model, thereby obtaining the mechanical heat prediction value within the first target mixing time output by the mechanical heat prediction model.

[0026] The aforementioned method for predicting mechanical heat during concrete mixing, through a pre-determined motor heat loss prediction model, mixing heat prediction model, shear heat prediction model, and a first target mixing time, can obtain relatively accurate predicted values ​​for motor heat loss, mixing heat, and shear heat within the first target mixing time. Based on a pre-determined mechanical heat prediction model characterizing the nonlinear relationship between mechanical heat and motor heat loss, mixing heat, and shear heat, and according to the predicted values ​​for motor heat loss, mixing heat, and shear heat within the first target mixing time, a relatively accurate predicted value for mechanical heat within the first target mixing time can be obtained. This process not only considers that mechanical heat mainly consists of motor heat loss, mixing heat, and shear heat (i.e., it considers the influence of factors such as motor-related parameters, mixer-related parameters, and concrete material-related parameters on mechanical heat during mixing), but also considers the nonlinear relationship between mechanical heat and motor heat loss, mixing heat, and shear heat. This avoids the limitations of existing technologies that predict mechanical heat based on only a few influencing factors, enabling a more comprehensive and multi-dimensional accurate prediction of mechanical heat, thus improving the accuracy of mechanical heat prediction results.

[0027] In one embodiment, the process of determining the mechanical heat prediction model includes: acquiring the concrete temperature rise in the mixer under different actual mixing times detected by a temperature detection device; determining the actual mechanical heat under different actual mixing times based on the concrete temperature rise, the preset concrete material mix ratio, and the preset concrete specific heat capacity; and obtaining the mechanical heat prediction model based on the nonlinear regression analysis method, the actual mechanical heat under different actual mixing times, multiple actual mixing times, the motor heat loss prediction model, the mixing heat prediction model, and the shear heat prediction model.

[0028] It is understandable that the temperature detection device can be used to detect the temperature rise of the concrete inside the mixer. The preset concrete mix proportion is a predetermined combination ratio of concrete materials. The preset concrete specific heat capacity is a predetermined concrete specific heat capacity. The actual mechanical heat is the mechanical heat actually calculated during the concrete mixing process.

[0029] Specifically, the processor can acquire the concrete temperature rise in the mixer under different actual mixing times detected by the temperature detection device during the actual concrete mixing process. Then, based on the concrete temperature rise, the preset concrete material mix ratio, and the preset concrete specific heat capacity, it determines the actual mechanical heat under different actual mixing times. Based on the nonlinear regression analysis method, it obtains the mechanical heat prediction model based on the actual mechanical heat under different actual mixing times, multiple actual mixing times, a pre-determined motor heat loss prediction model, a pre-determined mixing heat prediction model, and a pre-determined shear heat prediction model. In this process, the motor heat loss prediction model, the mixing heat prediction model, and the shear heat prediction model are all pre-determined models with the actual mixing time as the variable, and they participate in the entire nonlinear regression analysis process.

[0030] In this embodiment, the actual mechanical heat under different actual mixing times can be obtained by measuring the concrete temperature rise under different actual mixing times. Then, based on the nonlinear regression analysis method, a predetermined motor heat loss prediction model, mixing heat prediction model, and shear heat prediction model with the actual mixing time as the variable are fitted. Based on multiple actual mixing times, the actual mechanical heat corresponding to multiple actual mixing times, the motor heat loss prediction model, the mixing heat prediction model, and the shear heat prediction model, an accurate mechanical heat prediction model can be obtained to improve the accuracy of the mechanical heat prediction results.

[0031] In one embodiment, the actual mechanical heat can be determined by the following formula: Q j实 =m×C× In the formula, t represents the weight of the concrete (which can be calculated using a preset concrete mix design), and C represents the preset specific heat capacity of the concrete. t represents the temperature rise of the concrete.

[0032] In one embodiment, the motor heat loss prediction model satisfies the following formula: Q 电机 =P×(1-η) ×t Among them, Q 电机 Here, P represents the predicted heat loss of the motor, η represents the preset rated power of the motor, t represents the preset motor efficiency, and t represents the stirring time. It can be understood that the preset rated power and preset motor efficiency can be predetermined and are both related to the motor.

[0033] In the embodiments of this application, the predicted value of motor heat loss obtained by the above-mentioned motor heat loss prediction model takes into account relevant motor parameters, and can achieve accurate prediction of motor heat loss.

[0034] In one embodiment, the heat of stirring prediction model satisfies the following formula: Q 搅拌 =k×ρ×N 3 ×D5 ×t Among them, Q 搅拌 Here, k is the predicted heat of mixing, ρ is the preset resistance coefficient, ρ is the preset concrete density, N is the preset mixing shaft speed of the mixer, D is the preset mixer blade radius, and t is the mixing time. It can be understood that the preset resistance coefficient and preset concrete density can be predetermined and are both related to the concrete material; similarly, the preset mixing shaft speed, preset mixer blade radius, and preset resistance coefficient can be predetermined and are all related to the mixer itself.

[0035] In the embodiments of this application, the predicted heat of mixing obtained by the above-mentioned heat of mixing prediction model takes into account the relevant parameters of concrete materials and the relevant parameters of mixer, and can achieve accurate prediction of heat of mixing.

[0036] In one embodiment, the shear heat prediction model satisfies the following formula: Q 剪切 =μ×γ 2 ×V×t Among them, Q 剪切 Here, μ is the predicted shear heat, γ is the preset effective concrete viscosity, γ is the preset average shear rate, V is the preset concrete volume, and t is the mixing time. It can be understood that the preset effective concrete viscosity, preset average shear rate, and preset concrete volume can be predetermined and are all related to the concrete material.

[0037] In the embodiments of this application, the shear heat prediction value obtained by the above-mentioned shear heat prediction model takes into account the relevant parameters of concrete materials, and can achieve accurate prediction of shear heat.

[0038] Figure 2 The illustration schematically shows a flow chart of a method for controlling the outlet temperature of a concrete mixing plant according to an embodiment of this application. Figure 2 As shown in the figure, this application provides a method for controlling the temperature at the outlet of a concrete mixing plant. Taking the application of this control method to a processor as an example, the control method may include the following steps: Step S202: Obtain the initial controlled inlet temperature of the target concrete material, the initial controlled ice amount of the concrete mixing plant's ice system, the second target mixing time of the concrete mixing plant's mixer, and the target outlet temperature of the concrete.

[0039] Step S204: Determine the mechanical heat prediction value within the second target mixing time based on the second target mixing time, wherein the mechanical heat prediction value is predicted according to the method for predicting mechanical heat during concrete mixing in the above embodiment.

[0040] Step S206: Based on the predetermined outlet temperature prediction model, determine the initial outlet temperature prediction value according to the initial controlled inlet temperature, the initial controlled amount of ice added to the concrete, and the mechanical heat prediction value within the second target mixing time. The outlet temperature prediction model characterizes the relationship between the outlet temperature and the controlled inlet temperature of the concrete material, the controlled amount of ice added to the concrete by the ice adding system, and the mechanical heat during the concrete mixing process.

[0041] Step S208: If the temperature deviation between the initial predicted outlet temperature and the target outlet temperature exceeds the preset temperature deviation range, adjust the initial controlled inlet temperature and the initial controlled concrete ice addition amount until the temperature deviation is within the preset temperature deviation range, so as to obtain the target controlled inlet temperature of the target concrete material and the target controlled concrete ice addition amount of the ice addition system.

[0042] Step S210: Control the operation of the concrete mixing plant according to the target controlled inlet temperature and the target controlled amount of ice added to the concrete.

[0043] It is understandable that a concrete mixing plant (such as a hydraulic mixing plant) may include an ice-adding system, a mixer, etc. The ice-adding system can cool the concrete material before or during mixing. In addition, concrete mixing plants usually include an air-cooling system, which can cool the concrete material before mixing. For example, when the air-cooling system is located in the storage silo, it can cool the concrete material in the storage silo that has not yet entered the mixer. The target concrete material is the desired concrete material. The initial controlled inlet temperature is the initially preset controlled temperature of the target concrete material before it enters the mixer. The initial controlled concrete ice amount is the initially preset amount of ice added by the ice-adding system to pre-cool the concrete. For example, it can refer to the amount of ice added per unit volume of concrete or the total amount of ice added. The second target mixing time is the desired mixing time of the concrete mixing process in the actual application scenario of concrete mixing plant outlet temperature control. The target outlet temperature is the desired outlet temperature of the concrete mixing plant, specifically referring to the concrete temperature measured at 5cm-10cm below the concrete surface by sampling at the outlet of the concrete mixing plant. The outlet temperature prediction model is a computational model used to predict the outlet temperature of a concrete mixing plant. It characterizes the relationship between the outlet temperature and the controlled inlet temperature of the concrete material, the controlled amount of ice added by the icing system, and the mechanical heat during the concrete mixing process. The initial outlet temperature prediction value is calculated based on the initial controlled inlet temperature of the target concrete material, the initial controlled amount of ice added by the icing system, and the predicted mechanical heat value within the second target mixing time. The preset temperature deviation range is the pre-set allowable deviation range between the predicted outlet temperature value and the target outlet temperature. The target controlled inlet temperature is the finally determined controlled inlet temperature of the target concrete material. The target controlled amount of ice added is the finally determined amount of ice added by the icing system.

[0044] Specifically, the processor can acquire the initial controlled inlet temperature of the target concrete material, the initial controlled amount of ice added to the concrete mixing plant's ice-adding system, the second target mixing time of the concrete mixing plant's mixer, and the target outlet temperature of the concrete. Then, based on the method for predicting mechanical heat during the concrete mixing process described in the above embodiments, it determines the predicted mechanical heat value within the second target mixing time. Thus, based on a pre-determined outlet temperature prediction model, and according to the initial controlled inlet temperature, the initial controlled amount of ice added to the concrete, and the predicted mechanical heat value within the second target mixing time, it determines the initial predicted outlet temperature value. Further, the processor can compare the initial predicted outlet temperature value with the target outlet temperature. If the temperature deviation between the initial predicted outlet temperature value and the target outlet temperature exceeds a preset temperature deviation range, the processor can adjust the initial controlled inlet temperature and the initial controlled amount of ice added to the concrete until the temperature deviation between the predicted outlet temperature value and the target outlet temperature is within the preset temperature deviation range, thereby obtaining the target controlled inlet temperature of the target concrete material and the target controlled amount of ice added to the ice-adding system. Finally, the processor can control the operation of the concrete mixing plant based on the target controlled inlet temperature and the target controlled amount of ice added to the concrete.

[0045] The above-mentioned method for controlling the outlet temperature of a concrete mixing plant involves determining a mechanical heat prediction value based on a second target mixing time. Based on a pre-determined outlet temperature prediction model, and considering the initial controlled inlet temperature of the target concrete material, the initial controlled amount of ice added to the ice-adding system, and the mechanical heat prediction value within the second target mixing time, an initial outlet temperature prediction value is determined. If the temperature deviation between the initial outlet temperature prediction value and the target outlet temperature exceeds a preset temperature deviation range, the initial controlled inlet temperature and the initial controlled amount of ice added to the concrete material are adjusted until the temperature deviation falls within the preset temperature deviation range. This yields the target controlled inlet temperature of the target concrete material and the target controlled amount of ice added to the ice-adding system. The concrete mixing plant operation is then controlled based on these target controlled inlet temperatures and the target controlled amount of ice added to the concrete material. The above process can obtain accurate mechanical heat through the second target mixing time, and then obtain an accurate initial outlet temperature prediction value based on the mechanical heat. By comparing the deviation between the initial outlet temperature prediction value and the target outlet temperature, it is determined whether the initial control temperature of the target concrete material and the initial control amount of ice added to the concrete by the ice adding system are appropriate. Then, the most suitable cooling method is selected, that is, the most suitable cooling parameters are selected, so as to achieve precise control of the outlet temperature of the concrete mixing plant.

[0046] In one embodiment, the outlet temperature prediction model includes the following formula:

[0047] in, The temperature at the outlet of the concrete mixing plant (°C) For each cubic meter of concrete, the first The mass of the material (kg / m³) For the first The specific heat capacity of the material (kJ / (kg·℃)) For the first The temperature (°C) of the material after air cooling. The cold energy utilization rate of ice is expressed as a decimal; 1.0 can be used for dry ice heated to sub-zero temperatures, and 0.9 for moist ice. 355 represents the latent heat of fusion of ice (kJ / kg). The amount of ice added per cubic meter of concrete (kg / m³) The mechanical heat generated during the mixing of each cubic meter of concrete (kg / m³). This represents the total number of material types.

[0048] In one embodiment, the control method further includes: controlling the operation of the concrete mixing plant based on the initial controlled inlet temperature and the initial controlled amount of ice added to the concrete, provided that the temperature deviation between the initial predicted outlet temperature and the target outlet temperature is within a preset temperature deviation range.

[0049] Specifically, if the temperature deviation between the initial predicted outlet temperature and the target outlet temperature is within the preset temperature deviation range, the processor does not need to make multiple selections and can directly determine the cooling method based on the initial controlled inlet temperature and the initial controlled amount of ice added to the concrete, thereby controlling the operation of the concrete mixing plant.

[0050] like Figure 3 As shown, a hydraulic mixing plant is a mixing plant used to produce pre-cooled concrete. Pre-cooled concrete refers to a process in which the temperature of raw materials (such as aggregates, water, cement, etc.) or mixtures is reduced in advance by specific technical means before or during concrete mixing, thereby controlling the temperature of the concrete at the outlet of the mixer.

[0051] Commonly used precooling processes include air cooling, ice cooling, and water cooling. Air cooling refers to adding air cooling equipment to the aggregate storage silo, using cold air circulation to cool the aggregate. Ice cooling refers to adding ice to the aggregate to lower its temperature. Water cooling refers to adding cold water as a raw material to lower the temperature.

[0052] Controlling the outlet temperature typically requires first predicting mechanical heat, and then using this mechanical heat and the raw material control temperature to predict the outlet temperature. After the pre-cooling system and raw material control temperature are set, the air-cooling system cools the aggregate in the storage silo. The cooled aggregate is stored in the cone section of the storage silo and, during production, is unloaded into a sand and gravel scale for weighing. After weighing, it is unloaded into a transition hopper via system instructions. Simultaneously, an ice scale weighs the aggregate according to the set ice quantity and unloads it into a conveyor via system instructions. The conveyor then transports the aggregate to the transition hopper, and finally, the raw materials in the transition hopper are unloaded into the mixer for mixing to produce concrete. Since the outlet temperature of the concrete mixing plant is related to mechanical heat, accurate prediction of mechanical heat is crucial for achieving precise outlet temperature control.

[0053] In existing technologies, the mechanical heat prediction during the concrete mixing process is usually calculated using empirical formulas, typically Q. j =42Pt / V, where P is the mixer power (kW), t is the mixing time (min), and V is the mixer discharge volume (m³). In this empirical formula, mechanical heat is only related to the mixer power, mixing time, and discharge volume. However, in the actual concrete mixing process, in addition to the above factors affecting mechanical heat, other factors such as mixer blade parameters and raw material ratios also affect mechanical heat.

[0054] Furthermore, the empirical formulas mentioned above show that mechanical heat increases with mixing time, indicating a linear change in mechanical heat. However, in actual concrete mixing, once raw materials enter the mixer, the mixer starts operating. As the amount of material added increases, the load on the mixer gradually increases, leading to a rise in mechanical heat. When all the material has been added, the mixer load stabilizes, and the mechanical heat also stabilizes. Finally, after mixing is complete, the mechanical heat returns to zero. It can be seen that in actual concrete mixing, mechanical heat rises from zero to a certain level, then increases from low to high, and finally returns to zero. This means that mechanical heat does not increase with mixing time but exhibits a non-linear change. In conclusion, the mechanical heat predicted using empirical formulas in existing technologies is inaccurate, and existing technologies suffer from inaccurate mechanical heat prediction results.

[0055] To address the aforementioned problems, a specific embodiment of this application provides a method for controlling the temperature at the outlet of a concrete mixing plant. This method uses an accurate mechanical-thermal calculation model to correct the concrete outlet calculation model, thereby improving the accuracy of the concrete outlet temperature control. The specific method is as follows: 1. A temperature sensor is installed inside the mixer to monitor and record the temperature change of the material over time in real time. t, combined with the concrete mix proportion, yields the measured mechanical heat Q. j实 =m×C× t, where m is the weight of concrete and C is the specific heat capacity of concrete. t represents the temperature rise of the concrete.

[0056] 2. The mechanical heat generated during the mixing process of the mixer consists of three parts: motor heat loss Q. 电机 The mixing heat Q generated by the sliding friction and collision between the blades and the concrete 搅拌 The shear heat Q generated by the friction between the aggregate and the slurry 剪切 Each of the three establishes an independent computational model with time t as the variable: Q 电机 =P×(1-η) ×t, where P is the rated power of the motor, η is the motor efficiency, and t is the stirring time; Q 搅拌 =k×ρ×N 3 ×D 5 ×t, where k is the resistance coefficient, ρ is the concrete density, N is the rotational speed of the mixing shaft, D is the radius of the mixing blades, and t is the mixing time; Q 剪切 =μ×γ 2 ×V×t, where μ is the effective viscosity of concrete, γ is the average shear rate, V is the volume of concrete, and t is the mixing time.

[0057] 3. By fitting the above three calculation models using nonlinear regression analysis, a calculation model for theoretical mechanical heat is obtained. For example, the model expression can be Q. j模 =f(Q 电机 Q 搅拌 Q 剪切 Then, the model expression Q j模 The data was input into simulation analysis software for simulation, and combined with the measured value Q. j实 The model is then modified to obtain an accurate mechanical-thermal calculation model Q. j .

[0058] 4. Substitute the mechanical thermal calculation model into the background calculation model for the concrete mixing plant outlet temperature, and determine whether the deviation between the predicted outlet temperature and the target outlet temperature coincides with the allowable fluctuation range. If they coincide, the cooling method is considered to meet the design requirements; if they do not coincide, the coarse aggregate cooling temperature and water-cooling / ice-cooling parameters are adjusted until they meet the design requirements.

[0059] In summary, existing technologies all neglect the non-linear variation of mechanical heat in actual mixing processes. Calculating mechanical heat using empirical formulas leads to significant discrepancies between the obtained outlet temperature and the actual temperature. This patent addresses this issue by establishing a mechanical heat calculation model for the mixer to obtain simulated mechanical heat values. These simulated values ​​are then corrected using measured values ​​to arrive at a more accurate mechanical heat calculation model. Finally, this model is substituted into the calculation model for the concrete mixing plant's outlet temperature. By comparing the predicted and target outlet temperatures and determining if the deviation falls within a preset range, the suitability of the cooling method is assessed. This allows for the selection of the most appropriate cooling method, thereby further improving the control accuracy of the concrete outlet temperature.

[0060] This application provides an apparatus for predicting mechanical heat during concrete mixing. The apparatus includes: a memory configured to store instructions; and a processor configured to retrieve instructions from the memory and, when executing the instructions, to implement the method for predicting mechanical heat during concrete mixing according to the above embodiments.

[0061] This application provides a control device for the outlet temperature of a concrete mixing plant. The control device includes: a memory configured to store instructions; and a processor configured to retrieve instructions from the memory and, when executing the instructions, to implement the control method for the outlet temperature of a concrete mixing plant according to the above embodiments.

[0062] This application provides a concrete mixing plant, including: a device for predicting mechanical heat during the concrete mixing process according to the above embodiments; or a device for controlling the outlet temperature of the concrete mixing plant according to the above embodiments.

[0063] This application provides a machine-readable storage medium storing instructions for causing a machine to perform a method for predicting mechanical heat during concrete mixing according to the above embodiments.

[0064] This application provides a machine-readable storage medium storing instructions for causing a machine to execute a method for controlling the temperature at the outlet of a concrete mixing plant according to the above embodiments.

[0065] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0066] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0067] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0068] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0069] In a typical configuration, a computing device includes one or more processors (CPU), input / output interfaces, network interfaces, and memory.

[0070] Memory may include non-persistent memory in computer-readable media, such as random access memory (RAM) and / or non-volatile memory, such as read-only memory (ROM) or flash RAM. Memory is an example of computer-readable media.

[0071] Computer-readable media includes both permanent and non-permanent, removable and non-removable media that can store information using any method or technology. Information can be computer-readable instructions, data structures, modules of programs, or other data. Examples of computer storage media include, but are not limited to, phase-change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technologies, CD-ROM, digital versatile optical disc (DVD) or other optical storage, magnetic tape, disk storage or other magnetic storage devices, or any other non-transferable medium that can be used to store information accessible by a computing device. As defined herein, computer-readable media does not include transient computer-readable media, such as modulated data signals and carrier waves.

[0072] It should also be noted that the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0073] The above are merely embodiments of this application and are not intended to limit the scope of this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of the claims of this application.

Claims

1. A method for predicting the mechanical heat during concrete mixing, characterized in that, The method includes: To obtain the first target mixing time for the concrete mixing process; Based on a predetermined motor heat loss prediction model, a mixing heat prediction model, and a shear heat prediction model, the predicted values ​​of motor heat loss, mixing heat generated by sliding friction and collision between the mixer blades and concrete, and shear heat generated by friction between aggregates and slurry within the first target mixing time are determined according to the first target mixing time. The motor heat loss prediction model, the mixing heat prediction model, and the shear heat prediction model are all models with mixing time as a variable. Based on a predetermined mechanical heat prediction model, the mechanical heat prediction value within the first target stirring time is determined according to the predicted values ​​of motor heat loss, stirring heat, and shear heat. The mechanical heat prediction model characterizes the nonlinear relationship between mechanical heat and motor heat loss, stirring heat, and shear heat.

2. The method according to claim 1, characterized in that, The process of determining the mechanical thermal prediction model includes: The temperature rise of concrete in the mixer under different actual mixing times was obtained by a temperature detection device. Based on the concrete temperature rise, the preset concrete material mix ratio, and the preset concrete specific heat capacity, the actual mechanical heat under different actual mixing times is determined. Based on nonlinear regression analysis, the mechanical heat prediction model is obtained according to the actual mechanical heat under different actual stirring times, multiple actual stirring times, the motor heat loss prediction model, the stirring heat prediction model, and the shear heat prediction model.

3. The method according to claim 1, characterized in that, The motor heat loss prediction model satisfies the following formula: Q 电机 =P×(1-η)×t Among them, Q 电机 P is the predicted value of motor heat loss, η is the preset rated power of the motor, t is the preset motor efficiency, and t is the stirring time. The stirring heat prediction model satisfies the following formula: Q 搅拌 =k×ρ×N 3 ×D 5 ×t Among them, Q 搅拌 ρ is the predicted value of mixing heat, k is the preset resistance coefficient, ρ is the preset concrete density, N is the preset mixing shaft speed of the mixer, D is the preset mixer blade radius, and t is the mixing time. The shear heat prediction model satisfies the following formula: Q 剪切 =μ×γ 2 ×V×t Among them, Q 剪切 γ is the predicted shear heat value, μ is the preset effective viscosity of concrete, γ is the preset average shear rate, V is the preset concrete volume, and t is the mixing time.

4. A method for controlling the temperature at the outlet of a concrete mixing plant, characterized in that, The control method includes: The initial control temperature of the target concrete material entering the machine, the initial control amount of ice added to the concrete mixing plant's ice system, the second target mixing time of the concrete mixing plant's mixer, and the target outlet temperature of the concrete are obtained. The mechanical heat prediction value within the second target mixing time is determined based on the second target mixing time, wherein the mechanical heat prediction value is predicted by the method for predicting mechanical heat during concrete mixing according to any one of claims 1 to 3; Based on a predetermined outlet temperature prediction model, the initial outlet temperature prediction value is determined according to the initial controlled inlet temperature, the initial controlled amount of ice added to the concrete, and the mechanical heat prediction value within the second target mixing time. The outlet temperature prediction model characterizes the relationship between the outlet temperature and the controlled inlet temperature of the concrete material, the controlled amount of ice added to the concrete by the ice adding system, and the mechanical heat during the concrete mixing process. If the temperature deviation between the initial predicted outlet temperature and the target outlet temperature exceeds the preset temperature deviation range, the initial controlled inlet temperature and the initial controlled concrete ice addition amount are adjusted until the temperature deviation is within the preset temperature deviation range, so as to obtain the target controlled inlet temperature of the target concrete material and the target controlled concrete ice addition amount of the ice addition system. The operation of the concrete mixing plant is controlled based on the target controlled inlet temperature and the target controlled amount of ice added to the concrete.

5. The control method according to claim 4, characterized in that, Also includes: If the temperature deviation between the initial predicted outlet temperature and the target outlet temperature is within a preset temperature deviation range, the operation of the concrete mixing plant is controlled according to the initial controlled inlet temperature and the initial controlled amount of ice added to the concrete.

6. An apparatus for predicting mechanical heat during concrete mixing, characterized in that, The device includes: The memory is configured to store instructions; and The processor is configured to retrieve the instructions from the memory and, when executing the instructions, to implement the method for predicting mechanical heat during concrete mixing according to any one of claims 1 to 3.

7. A device for controlling the temperature at the outlet of a concrete mixing plant, characterized in that, The control device includes: The memory is configured to store instructions; and The processor is configured to retrieve the instructions from the memory and, when executing the instructions, to implement the method for controlling the outlet temperature of a concrete mixing plant according to claim 4 or 5.

8. A concrete mixing plant, characterized in that, include: The apparatus for predicting mechanical heat during concrete mixing as described in claim 6. Or the control device for the outlet temperature of the concrete mixing plant as described in claim 7.

9. A machine-readable storage medium, characterized in that, The machine-readable storage medium stores instructions for causing the machine to perform the method for predicting mechanical heat during concrete mixing according to any one of claims 1 to 3.

10. A machine-readable storage medium, characterized in that, The machine-readable storage medium stores instructions for causing the machine to perform the control method for the outlet temperature of the concrete mixing plant as described in claim 4 or 5.

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