Temperature and flow double-closed-loop control method, system, equipment and medium

Abstract

The invention discloses a temperature and flow double-closed-loop control method, system, equipment and medium, and belongs to the technical field of industrial process control, and the method comprises the steps: calculating an instantaneous heat exchange load by combining a filtering temperature output current variable, a filtering flow output current variable and an inlet temperature with a volume heat capacity parameter, and carrying out recursive updating to obtain load disturbance estimation; calculating a temperature tracking error, and generating a flow set value subjected to hard constraint and slope constraint; the flow set value serves as a set value of a PID controller, and control output is calculated on the basis of the filtering flow output current-period variable; and executing low-flow freezing protection, actuator saturation tracking insufficient protection and overtemperature protection, and outputting updated flow upper and lower limits, weight factors and a manual control state as inputs of optimization calculation of a next sampling period. Through closed-loop processing of inner and outer rings and feedback of protection and constraint results to an optimization link, temperature response acceleration, smooth flow regulation and timely safety protection are realized.

Description

Technical Field

[0001] This invention relates to the field of industrial process control technology, specifically to a dual closed-loop control method, system, equipment, and medium for temperature and flow. Background Technology

[0002] In existing industrial process control fields, coupled temperature and flow control is a common requirement. For example, in heat exchangers, air conditioning units, heat pumps, and industrial cooling systems, temperature-flow dual-variable regulation is commonly used to maintain process stability. A common implementation in existing technologies is cascaded control, where an outer-loop temperature controller calculates the flow setpoint, which is then executed by an inner-loop flow controller. Typically, the outer-loop temperature controller uses proportional-integral-derivative (PID) control, while the inner-loop flow controller directly uses a conventional PID controller to achieve closed-loop flow regulation. Furthermore, to reduce the impact of temperature fluctuations, some research has attempted to improve temperature regulation accuracy using disturbance observation methods or model predictive control methods, but classical control methods remain the dominant approach.

[0003] However, existing technologies have significant shortcomings in practical applications: on the one hand, the calculation of flow setpoints lacks a unified optimization mechanism, making it impossible to simultaneously balance temperature tracking accuracy, the smoothness of setpoint changes, and energy efficiency, resulting in low operational energy efficiency. On the other hand, protection and constraint mechanisms are often independent of the control logic, making it difficult to achieve real-time dynamic adjustments in closed-loop optimization, thus increasing operational risks. Summary of the Invention

[0004] In view of the above-mentioned problems, the present invention is proposed.

[0005] Therefore, the technical problem solved by this invention is that the calculation of flow setpoints lacks a unified optimization mechanism, which cannot simultaneously balance temperature tracking accuracy, the smoothness of setpoint changes and energy efficiency, resulting in low operating energy efficiency. Furthermore, protection and constraint links are often independent of control logic, making it difficult to achieve real-time dynamic adjustment in closed-loop optimization.

[0006] To solve the above-mentioned technical problems, the present invention provides the following technical solution: a dual closed-loop control method for temperature and flow, comprising the following steps: Read the inlet temperature, temperature measurement value, and flow measurement value. Filter the temperature measurement value and flow measurement value to obtain the current variable of the filtered temperature output and the current variable of the filtered flow output. Combine the volumetric heat capacity parameter to calculate the current cycle load disturbance estimate. The temperature tracking error is calculated based on the current cycle load disturbance estimate, the current variable of the filtered temperature output, the inlet temperature, and the current variable of the filtered flow output. The weighting factor of the flow change is combined with the flow constraint to generate the flow setpoint. The flow rate setpoint is used as the controller setpoint, and the control output is calculated based on the current variable of the filtered flow rate output. Implement protection mechanisms, adjust traffic constraints, weighting factors, and manually control the status; The adjusted flow constraints and weighting factors are output and used as input for the optimization calculation in the next sampling period.

[0007] As a preferred embodiment of the temperature and flow dual closed-loop control method of the present invention, the step of calculating the current cycle load disturbance estimate by combining the volumetric heat capacity parameter includes: The current variables of the filtered temperature output and the filtered flow rate output, as well as the inlet temperature and volumetric heat capacity parameters are used as the input for calculating the instantaneous heat transfer load. The instantaneous heat transfer load is calculated based on the input quantities and volumetric heat capacity parameters. The current cycle load disturbance estimate is calculated using the current value of instantaneous heat exchange load.

[0008] The beneficial effects of this preferred technical solution are as follows: by calculating the current cycle load disturbance estimate through energy balance calculation and recursive method, dynamic disturbance compensation is realized, the accuracy of temperature prediction is improved, and the problem of slow response of traditional methods is overcome.

[0009] As a preferred embodiment of the temperature and flow dual closed-loop control method of the present invention, the step of calculating the weighting factor of temperature tracking error combined with flow rate change, and applying flow constraints to generate the flow rate setpoint includes: The predicted temperature is calculated by estimating the load disturbance, using the current variable of the filtered temperature output, and using the current variable of the inlet temperature and the current variable of the filtered flow rate output. The temperature tracking error is calculated based on the difference between the predicted temperature and the target temperature setpoint. Calculate the preliminary flow rate based on the temperature tracking error and the flow rate change weighting factor; Apply flow constraints to the initial flow rate and simultaneously apply flow rate change slope constraints to generate flow setpoints.

[0010] The beneficial effects of this preferred technical solution are: it simultaneously considers temperature accuracy, setpoint smoothness, and energy consumption constraints, achieving global optimization of the setpoint, avoiding sudden changes in flow setting and excessive energy consumption, and ensuring the stability and energy saving of the control process.

[0011] As a preferred embodiment of the temperature and flow dual closed-loop control method of the present invention, the step of calculating the control output based on the current variable of the filtered flow output includes: Read the flow rate setting and write it to the controller's setting port; Set the closed-loop activation port of the fixed controller to true and the manual activation port to false to ensure that the controller is in automatic closed-loop operation mode. The current flow error is calculated based on the flow setpoint and the current variable of the filtered flow output, and then converted into a control output.

[0012] As a preferred embodiment of the temperature and flow dual closed-loop control method of the present invention, the steps of adjusting the flow constraint, weighting factor, and manual control state include: Compare the current variable of the filtered flow output with the frozen flow threshold. When the current variable of the filtered flow output is less than the frozen flow threshold, raise the lower limit of the flow to the frozen flow threshold and increase the smoothing weight in the weighting factors. When the actuator output is equal to the boundary value of the set output range and the current flow error is greater than the preset flow deviation threshold, the smoothing weight and energy consumption weight in the weighting factor will be increased synchronously. When the actuator output meets the set output range or the current flow error is less than or equal to the preset flow deviation threshold, the smoothing weight and energy consumption weight in the weighting factor remain unchanged. Collect the real-time temperature of the controlled object, determine whether the real-time temperature is greater than the safe temperature threshold, and when the real-time temperature is greater than the safe temperature threshold, adjust the flow setpoint to the upper limit of the flow constraint, switch the control state to manual mode, and fix the manual output value to the safe opening degree until the temperature returns to the normal range. When the real-time temperature is less than or equal to the safe temperature threshold, the flow constraint remains unchanged.

[0013] As a preferred embodiment of the temperature and flow dual closed-loop control method of the present invention, the step of outputting the adjusted flow constraint and weighting factor as input for the optimization calculation in the next sampling period includes: Based on the adjusted weighting factors, and combined with the load disturbance estimate for the next sampling period, the current variable of the filtered temperature output, the inlet temperature, and the current variable of the filtered flow output, a preliminary flow setpoint is generated. Based on the adjusted flow constraints, the initial flow setting constraints are applied, and simultaneously, the flow change slope constraints are applied to generate the flow setting value for the next sampling period. The current flow error is calculated based on the flow setpoint for the next sampling period and the current variable of the filtered flow output for the next sampling period, and then the current flow error is converted into the control output for the next sampling period.

[0014] The beneficial effects of this preferred technical solution are as follows: through the inner loop rapid flow closed-loop control, the accurate tracking of flow setting and the stable operation of the actuator are ensured, thereby improving the speed and accuracy of overall temperature regulation.

[0015] As a preferred embodiment of the temperature and flow dual closed-loop control method of the present invention, the conversion formula for converting the current flow error into the control output is: ; in, To control the output, As a proportional parameter, it determines the direct strength of the error's effect on the control quantity. The integral parameter is used to eliminate steady-state deviation by accumulating historical errors. As a differential parameter, the response is anticipated based on the rate of change of error, thereby improving dynamic performance. This is the current flow error. The flow rate error is from the previous sampling period. Indicates the first The error from each sampling is used for integration and accumulation. The sampling period.

[0016] This invention provides a dual closed-loop control system for temperature and flow.

[0017] To solve the above-mentioned technical problems, the present invention further provides the following technical solution: a temperature and flow dual closed-loop control system, comprising: Data acquisition module: Reads inlet temperature, temperature measurement value, and flow rate measurement value; Preprocessing module: Filters the temperature and flow measurement values ​​to obtain the filtered temperature and flow output variables for the current period; First data calculation module: Calculates instantaneous heat transfer load based on the current variables of inlet temperature, filtered temperature output, and filtered flow rate output, combined with volumetric heat capacity parameters, and performs recursive updates to obtain the current cycle load disturbance estimate; The second data calculation module calculates the temperature tracking error based on the current cycle load disturbance estimate, the current variable of the filtered temperature output, the inlet temperature, and the current variable of the filtered flow output, and applies flow constraints to generate the flow setpoint. Control module: It uses the flow setpoint as the controller setpoint and calculates the control output based on the current variable of the filtered flow output; Data adjustment module: performs low flow freeze protection, actuator saturation tracking insufficiency protection, and over-temperature protection; adjusts flow upper and lower limits, smoothing weight, energy consumption weight, and manual control status.

[0018] The present invention provides a computer device, including a memory and a processor, wherein the memory stores a computer program, characterized in that the processor, when executing the computer program, implements the steps of a dual closed-loop control method for temperature and flow.

[0019] The present invention provides a computer-readable storage medium having a computer program stored thereon, characterized in that the computer program, when executed by a processor, implements the steps of a dual closed-loop control method for temperature and flow.

[0020] The beneficial effects of this invention are as follows: This invention calculates the current cycle load disturbance estimate through energy balance calculation and recursive method, realizing dynamic disturbance compensation, improving the accuracy of temperature prediction, and effectively overcoming the problem of slow response of traditional methods; This invention simultaneously considers temperature accuracy, setpoint smoothness, and energy consumption constraints, realizing global optimization of the setpoint, avoiding sudden changes in flow setting and excessive energy consumption, and ensuring the stability and energy saving of the control process; Through inner-loop fast flow closed-loop control, it ensures accurate tracking of flow setting and stable operation of actuator, improving the speed and accuracy of overall temperature regulation. Attached Figure Description

[0021] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0022] Figure 1 The above is a flowchart of a dual closed-loop control method for temperature and flow provided in one embodiment of the present invention. Detailed Implementation

[0023] To make the above-mentioned objects, features, and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the protection scope of the present invention.

[0024] Example 1, referring to Figure 1 This is the first embodiment of the present invention, which provides a dual closed-loop control method for temperature and flow rate, comprising: S100: Reads inlet temperature, temperature measurement value, and flow measurement value; filters the temperature measurement value and flow measurement value to obtain the current variable of filtered temperature output and the current variable of filtered flow output; and calculates the current cycle load disturbance estimate by combining the volume heat capacity parameter. S200: Calculates the temperature tracking error and the weighting factor of flow change based on the current cycle load disturbance estimate, the current variable of the filtered temperature output, the inlet temperature, and the current variable of the filtered flow output, and applies flow constraints to generate the flow setpoint. S300: Uses the flow rate setpoint as the controller setpoint and calculates the control output based on the current variable of the filtered flow rate output; S400: Implements protection mechanisms, adjusts traffic constraints, weighting factors, and manual control status; S500: Outputs the adjusted flow constraints and weighting factors, which also serve as input for the optimization calculation in the next sampling period.

[0025] It should be noted that in industrial control scenarios, the inherent defects of existing technologies for temperature and flow control have become a bottleneck restricting the safe and efficient operation of systems. Due to the lack of a unified optimization mechanism for flow setpoint calculation, temperature tracking accuracy, setpoint smoothness, and energy efficiency are often in conflict. For example, pursuing rapid temperature target achievement may lead to drastic fluctuations in flow setpoints, or sacrificing temperature control accuracy to reduce energy consumption, ultimately resulting in low system energy efficiency and increased unnecessary energy and equipment wear. On the other hand, the design of protection and constraint links independent of the control logic means that risks such as low flow freezing, actuator saturation, and overheating cannot be linked to closed-loop optimization. When operating conditions change abruptly, protection actions lag behind control requirements, making it difficult to quickly avoid safety hazards. Furthermore, the disconnect between protection and control may cause secondary failures, threatening equipment lifespan and process stability, directly impacting production continuity and operational economy. Therefore, proposing a dual closed-loop control method for temperature and flow is crucial. Therefore, the control of temperature and flow has become a bottleneck restricting the safe and efficient operation of the system. Through steps S100 to S500, the current cycle load disturbance estimate is calculated using energy balance calculation and recursive methods, achieving dynamic disturbance compensation, improving the accuracy of temperature prediction, and effectively overcoming the slow response problem of traditional methods. This invention also considers temperature accuracy, setpoint smoothness, and energy consumption constraints, achieving global optimization of the setpoint, avoiding sudden changes in flow setting and excessive energy consumption, and ensuring the stability and energy saving of the control process. Through the inner loop fast flow closed-loop control, the accurate tracking of the flow setting and the stable operation of the actuator are ensured, improving the speed and accuracy of the overall temperature regulation.

[0026] Example 2, refer to Figure 1 This is the second embodiment of the present invention, which provides a dual closed-loop control method for temperature and flow.

[0027] In this embodiment of the application, in step S100, the inlet temperature, temperature measurement value, and flow measurement value are read. The inlet temperature of the heat exchanger is read by a resistance temperature sensor, the temperature measurement value of the heat exchanger is read by a thermocouple temperature sensor, and the volumetric flow rate of the liquid entering the heat exchanger is read by an electromagnetic flow meter.

[0028] During the temperature cycle task, the current code values ​​of the temperature input channel, inlet temperature input channel, and flow input channel are read synchronously, uniformly calibrated into engineering units, and then written into the temperature variable, inlet temperature, and flow variable respectively. Specifically, at the same sampling moment of the temperature cycle task, the current code value is read from the temperature input channel, the inlet temperature input channel, and the flow input channel and latched as the original temperature code value, the original inlet temperature code value, and the original flow code value for this cycle. Based on the three latched code values ​​and the range and zero-point parameters of the corresponding channels, a unified calibration is performed to obtain the temperature value, the inlet temperature value, and the flow value in engineering units. Based on the three engineering unit values, the temperature variable, the inlet temperature, and the flow variable are written into the data storage area at once and kept consistent with the timestamp of this cycle.

[0029] In this embodiment of the application, in step S100, the temperature measurement value and the flow measurement value are filtered to obtain the current variable of the filtered temperature output and the current variable of the filtered flow output. The current variable of the filtered temperature output and the current variable of the filtered flow output are obtained by processing the temperature measurement value and the flow measurement value read in the current cycle using a first-order low-pass filtering algorithm.

[0030] In this embodiment of the application, the calculation of the current cycle load disturbance estimate in step S100, which combines the volumetric heat capacity parameter, includes the following steps A1 to A3: A1: The current variables of the filtered temperature output and the filtered flow rate output, as well as the inlet temperature and volumetric heat capacity parameters are paired as the input quantities for calculating the instantaneous heat transfer load; In this embodiment, the current variable of the filtered temperature output, the current variable of the filtered flow output, and the inlet temperature are synchronously obtained from a shared location using a read-only snapshot method. The current sampling timestamp is written to the local input buffer as a consistency verification benchmark. A timestamp consistency check and validity check are performed on the local input buffer. Specifically, the timestamps of the three data items are checked to be equal to the current sampling timestamp, and the validity flags of the temperature measurement and flow measurement are valid. If there is out-of-bounds data that has already been pasted, the pasted value is directly used to maintain data continuity, and the data that passes the check is written back to the valid area of ​​the local input buffer. Based on the content of the valid area, the data is then processed from... The parameter database reads the medium density and specific heat capacity parameters, and combines their product to form the volumetric heat capacity parameter, in joules per cubic meter per Kelvin. This data is then written to the parameter area of ​​the local input buffer, using a read-only constant table or a medium switching table as the parameter source. Based on the effective area and parameter area of ​​the local input buffer, at the end of the same sampling period, the current variables of the filtered temperature and filtered flow rate, along with the inlet temperature and volumetric heat capacity parameters, are packaged with the current sampling timestamp to form the instantaneous heat load calculation input. This input is written to the instantaneous heat load calculation input buffer, and after successful writing, the instantaneous heat load calculation input buffer is marked as "readable". A2: Calculate the instantaneous heat transfer load based on the input quantities and volumetric heat capacity parameters. In this embodiment of the application, the formula for calculating the instantaneous heat transfer load based on the input quantity of the instantaneous heat transfer load calculation and the volumetric heat capacity parameter is as follows: ; in, For instantaneous heat exchange load, The current variable is output for the filtered flow rate. The current variable is used to filter the temperature output. Inlet temperature, It is the volumetric heat capacity; In this embodiment of the application, the current variable of the filter flow rate output is set to 2.46 liters / second, the current variable of the filter temperature output is set to 47.93℃, and the inlet temperature is set to 18.2℃. Substituting these values ​​into the instantaneous heat exchange load calculation formula, the instantaneous heat exchange load is calculated to be 306148.92 kJ / h, which is approximately 85.04 kW.

[0031] It should be noted that the required volumetric heat capacity parameters are derived from the physical properties of the medium and the equipment data. If necessary, fine-tuning can be performed through one-time parameter identification, thereby providing stable, computationally efficient, and traceable instantaneous heat transfer calculations and one-step temperature predictions during operation, providing deterministic input for subsequent calculations.

[0032] In one alternative implementation, the instantaneous heat load can also be calculated using the heat balance difference method. By measuring the inlet and outlet temperatures and flow rates of the hot and cold fluids, the instantaneous heat load is calculated using the heat balance principle. In the heat exchanger system, the inlet temperature, outlet temperature, and outlet flow rate of the hot fluid, and the inlet temperature, outlet temperature, and outlet flow rate of the cold fluid are measured respectively. Based on the principle that the heat released by the hot fluid is equal to the heat absorbed by the cold fluid, the instantaneous heat load is calculated by substituting the data.

[0033] In another alternative implementation, the instantaneous heat load can also be calculated using an empirical formula method. Based on long-term experimental data, empirical formulas are summarized regarding the filter flow rate, filter temperature, inlet temperature, and instantaneous heat load. The instantaneous heat load is obtained by substituting the filter flow rate, filter temperature, and inlet temperature into the empirical formula.

[0034] A3: Calculate the current cycle load disturbance estimate using instantaneous heat exchange load.

[0035] In this embodiment of the application, the formula for generating the current cycle load disturbance estimate is as follows: ; in, For the current cycle load disturbance estimate, This is an estimate of the load disturbance for the previous cycle. This is the load disturbance smoothing factor. For instantaneous heat exchange load; In this embodiment, the instantaneous heat transfer load is set to 85kW, the estimated load disturbance of the previous cycle is 80kW, and the load disturbance smoothing factor is 0.4. Substituting these values ​​into the current cycle load disturbance estimation formula, the estimated load disturbance of the current cycle is calculated to be 82kW. It should be noted that, for the case where there is no load disturbance estimate for the previous period in the first sampling period, the instantaneous heat exchange load of the current period is directly used as the initial load disturbance estimate. Starting from the second sampling period, the calculation is performed according to the above recursive formula to ensure the continuity and stability of the load estimate.

[0036] In this embodiment of the application, the step S200 of calculating the weighting factor of temperature tracking error combined with flow rate change and applying flow rate constraints to generate the flow rate setpoint includes the following steps B1 to B4: B1: Calculate the predicted temperature by estimating the load disturbance, filtering the temperature output current variable, and using the inlet temperature and filtered flow output current variable; In this embodiment of the application, the formula for calculating the predicted temperature is: ; in, To predict temperature, The current variable is used to filter the temperature output. Inlet temperature, The current variable is output for the filtered flow rate. For load disturbance estimation, For volumetric heat capacity, The sampling period is This is the equivalent heat capacity.

[0037] In this embodiment, the current variable of the filter flow rate output is set to 2.46 liters / second, the current variable of the filter temperature output is set to 47.93°C, the inlet temperature is set to 18.2°C, the equivalent heat capacity is set to 10000, the volumetric heat capacity is set to 4186, the load disturbance estimate is set to 82kW, and the sampling period is set to 1 second. Substituting these values ​​into the predicted temperature calculation formula, the predicted temperature is calculated to be 47.93°C.

[0038] In one alternative implementation, the predicted temperature can also be calculated using a neural network. A neural network model is constructed, with the current variable of the filtered flow rate output, the current variable of the filtered temperature output, the inlet temperature, and the load disturbance estimate as inputs, and the actual temperature as the output for training. After the model is trained, the current variable of the filtered flow rate output, the current variable of the filtered temperature output, the inlet temperature, and the load disturbance estimate are input, and the predicted temperature is calculated by forward propagation of the neural network.

[0039] In another alternative implementation, the predicted temperature can also be calculated using linear regression prediction. Historical data on the current variable of filtered flow rate output, the current variable of filtered temperature output, the inlet temperature, the load disturbance estimate, and the corresponding actual temperature are collected. These data are divided into input and output items, and linear regression analysis is performed using statistical software to obtain a set of weighting coefficients. These coefficients represent the degree of influence of each input variable on the temperature. The current filtered flow rate, filtered temperature, inlet temperature, and load disturbance estimate are multiplied by their respective weighting coefficients, and all results are summed. Finally, a fixed correction value is added to obtain the predicted temperature.

[0040] B2: Calculate the temperature tracking error based on the difference between the predicted temperature and the target temperature setpoint; In this embodiment of the application, the formula for calculating the temperature tracking error is: ; in, For temperature tracking error, Set the target temperature value. To predict temperature; In this embodiment of the application, the predicted temperature is set to 47.93℃ and the target temperature is set to 50℃. Substituting these values ​​into the temperature tracking error calculation formula, the temperature tracking error is calculated to be 2.07℃.

[0041] B3: Calculate the preliminary flow rate based on the temperature tracking error and the flow rate change weighting factor; In this embodiment of the application, the formula for calculating the initial flow rate is: ; in, Set initial flow rate values. For temperature tracking error, A smoothing weight for traffic changes, used to suppress excessively rapid traffic adjustments. Energy consumption weights are used to reflect the weighting of energy consumption optimization. For reference traffic volume, the actual traffic volume setting value from the previous cycle can be used.

[0042] In this embodiment of the application, the temperature tracking error is set to 2.07℃, the smoothing weight is 0.5, the energy consumption weight is 0.6, the reference flow rate is 10 liters / second, and the initial flow rate is calculated to be 7.035 liters / second by substituting into the initial flow rate calculation formula.

[0043] It should be noted that, This item reflects the need to adjust the flow rate due to temperature deviations. The system references the traffic volume of the previous cycle, balancing energy consumption optimization with the smoothness of traffic adjustment, and avoiding excessively frequent traffic fluctuations.

[0044] B4: Apply flow constraints to the initial flow rate and simultaneously apply flow rate change slope constraints to generate flow setpoints.

[0045] In this embodiment, the flow constraint includes an upper flow limit and a lower flow limit. The initial flow is processed by interval approximation. That is, when the initial flow is less than the lower flow limit, the initial flow is adjusted to the lower flow limit. When the initial flow is greater than the upper flow limit, the initial flow is adjusted to the upper flow limit. When the initial flow is within the range of the lower flow limit to the upper flow limit, it remains unchanged. The adjusted result is recorded as the limit flow setting value. It should be noted that the lower limit and upper limit of flow rate represent the minimum allowable flow rate and the maximum allowable flow rate, respectively. Under normal circumstances, the lower limit of flow rate can be determined according to the pipe diameter of the equipment and the heat exchange requirements, for example, the value range is 0.05 to 0.2 liters / second, while the upper limit of flow rate is set according to the rated flow rate of the circulating pump, for example, the value range is 1.5 to 2.0 liters / second.

[0046] In this embodiment of the application, the lower limit of the flow rate is set to 0.1 liters / second and the upper limit of the flow rate is set to 2 liters / second. If the initial flow rate is 0.05 liters / second, the initial flow rate is adjusted to 0.1 liters / second. If the initial flow rate is 2.2 liters / second, the initial flow rate is adjusted to 2 liters / second.

[0047] In this embodiment, applying the flow rate change slope constraint involves forming a slope constraint window based on the reference flow rate, the maximum allowable flow rate change rate, and the sampling period. The upper limit boundary is equal to the reference flow rate plus the product of the maximum allowable flow rate change rate and the sampling period, and the lower limit boundary is equal to the reference flow rate minus the product of the maximum allowable flow rate change rate and the sampling period. The limit flow rate setting value is then adjusted again within the slope constraint window to the upper or lower limit boundary of the slope constraint window to obtain the flow rate setting value.

[0048] The formula for calculating the slope constraint window is: ; ; in, This is the upper bound of the slope constraint window. This represents the lower boundary of the slope constraint window. For reference traffic, For the maximum allowable rate of change of flow, The sampling period.

[0049] It should be noted that the maximum allowable rate of change of flow indicates the maximum rate of change that the flow setpoint can be allowed between two adjacent sampling periods. It is usually expressed as the "maximum allowable flow change per unit time", for example, a rate of change limit of 0.1 liters per second. If the sampling period is 1 second, then the maximum allowable flow change between two adjacent weeks is 0.1 liters.

[0050] In this embodiment of the application, the reference flow rate is set to 10 liters / second, the maximum allowable flow rate change rate is 0.1 liters / second, the sampling period is 1 second, and the upper limit boundary is calculated to be 10.1 liters / second and the lower limit boundary is 9.9 liters / second by substituting into the slope constraint window calculation formula.

[0051] If the initial flow rate after flow constraint adjustment is 9.5 liters / second, it needs to be adjusted to 9.9 liters / second according to the lower limit of the maximum allowable flow rate change, resulting in a flow rate setting of 9.9 liters / second. If the initial flow rate after flow constraint adjustment is 10 liters / second, no adjustment is needed, resulting in a flow rate setting of 10 liters / second. If the initial flow rate after flow constraint adjustment is 10.5 liters / second, it needs to be adjusted to 10.1 liters / second according to the upper limit of the maximum allowable flow rate change, resulting in a flow rate setting of 10.1 liters / second.

[0052] In this embodiment of the application, step S300, which calculates the control output based on the current variable of the filtered flow rate output, includes the following steps C1 to C4: C1: Read the flow rate setpoint and write it to the PID controller's setpoint port; In this embodiment, the flow rate setpoint is read and directly written into the setpoint port of the PID controller as the target input, thereby ensuring that the closed-loop control can be executed according to the expected flow rate obtained by optimization calculation; then, the current variable of the filtered flow rate output is read synchronously within the same sampling period, and the current variable of the filtered flow rate output is written into the input port of the PID controller as a real-time feedback quantity.

[0053] C2: Set the closed-loop activation port of the fixed PID controller to true and the manual activation port to false to ensure that the PID control is in automatic closed-loop operation. In this embodiment, the setpoint port and input port of the PID controller are used as the basic operating conditions. The closed-loop activation port is fixed to a logical true value to ensure that the controller is always in closed-loop operation mode. At the same time, the manual activation port is fixed to a logical false value to block the manual control channel, so that the controller is forced to enter the automatic operation state. Finally, the PID controller stably outputs control quantity in an automatic closed-loop manner within the current sampling period for the actuator to use, thereby maintaining the continuity with the output of the previous sampling period and ensuring that the subsequent execution actions are continuous and smooth.

[0054] C3: Calculate the current flow error based on the flow setpoint and the current variable of the filtered flow output, and convert the current flow error into a control output.

[0055] In this embodiment of the application, the formula for calculating the flow rate error is: ; in, For flow error, Set a value for the flow rate. Output the current period variable for the filtered flow rate; In this embodiment of the application, the flow rate setting value is set to 10 liters / second, the current variable of the filtered flow rate output is 9.5 liters / second, and the flow rate error is calculated to be 0.5 liters / second by substituting into the flow rate error calculation formula.

[0056] In this embodiment of the application, the calculation formula for converting the current flow error into control output is as follows: ; in, To control the output, As a proportional parameter, it determines the direct strength of the error's effect on the control quantity. The integral parameter is used to eliminate steady-state deviation by accumulating historical errors. As a differential parameter, the response is anticipated based on the rate of change of error, thereby improving dynamic performance. For flow error, The flow rate error is from the previous sampling period. Indicates the first The error from each sampling is used for integration and accumulation. is the sampling period, and k is the sampling period number.

[0057] In this embodiment, the flow rate error is set to 0.5 liters / second, the flow rate error of the previous sampling period is 0.3 liters / second, the proportional parameter is 2, the integral parameter is 0.5, and the derivative parameter is 1. Substituting these values ​​into the control output calculation formula, the following is obtained: The current control output is 1.6.

[0058] It should be noted that there is no previous sampling period in the first sampling period, so the flow error of the previous sampling period can be regarded as 0.

[0059] In one alternative implementation, the control output can also be calculated using fuzzy control. The flow error and error change rate are divided into three fuzzy levels: small, medium, and large. Fuzzy rules are then formulated based on experience or historical data. If the flow error is large and the error change rate is large, the control output is large. For example, if the current flow error is 0.5 liters / second and the flow error in the previous sampling period was 0.3 liters / second with an error change rate of 0.2 liters / second, the flow error is first determined to be in the large level and the error change rate to be in the small level. Then, according to the fuzzy rules, the corresponding fuzzy control output value is matched from the fuzzy rule library. Finally, the centroid method is used to defuzzify the fuzzy output and transform it into a precise control output.

[0060] In another alternative implementation, the control output can also be calculated using a nonlinear PID control method. The proportional, integral, and derivative parameters are dynamically changed according to the magnitude of the flow error. When the flow error is determined to be large, the proportional and derivative parameters are increased, and the integral parameter is decreased. Then, the calculation is performed according to the PID calculation logic, and finally the three results are added together to obtain the control output.

[0061] In this embodiment of the application, the execution of the protection mechanism in step S400, adjusting the flow constraints, weighting factors, and manual control status, includes the following steps D1~D1: D1: Compare the current variable of the filtered flow output with the frozen flow threshold. When the current variable of the filtered flow output is less than the frozen flow threshold, raise the lower limit of the flow to the frozen flow threshold and increase the smoothing weight in the weighting factors. In this embodiment of the application, the formula for adjusting the smoothing weight in the weighting factor is as follows: ; in, For the updated smoothing weights, For the smoothed weights before the update, The freeze adjustment factor for the smoothing weights; In this embodiment, the current variable of the filtered flow output is set to 0.2 liters / second, the frozen flow threshold is 0.25 liters / second, the lower limit of flow is 0.1 liters / second, the smoothing weight before the update is 0.5, and the freeze adjustment coefficient of the smoothing weight is 1.05. At this time, the current variable of the filtered flow output is less than the frozen flow threshold, triggering low flow freeze protection. The lower limit of flow should be adjusted from 0.1 liters / second to 0.25 liters / second of the frozen flow threshold. At the same time, the updated smoothing weight is calculated to be 1.05 × 0.5 = 0.525 according to the smoothing weight adjustment formula.

[0062] The current period's filtered flow output variable and the frozen flow threshold are written into the current period's judgment buffer. A freeze trigger flag is generated based on the current period's filtered flow output variable and the frozen flow threshold in the judgment buffer. The freeze trigger flag is set to valid only if the current period's filtered flow output variable is less than the frozen flow threshold. At this time, the freeze trigger flag, along with the current period's filtered flow output variable and the frozen flow threshold, are written into the constraint update buffer. Under the premise that the freeze trigger flag is valid, the lower limit variable of the flow is temporarily increased to the frozen flow threshold using the constraint update buffer as input. Based on the freeze trigger flag, the set smoothing weight is adjusted upwards in a one-time increment according to the preset micro-increment, and the updated smoothing weight is generated.

[0063] It should be noted that the freezing flow threshold refers to the minimum flow rate data under low-temperature risk conditions during historical operation, combined with the physical characteristics of the medium, such as the freezing point temperature of water or ethylene glycol solution at low temperatures, as well as the heat exchange area and flow channel characteristics of the equipment. This data serves as the physical basis for the occurrence of freezing risk. The minimum stable flow rate corresponding to the freezing point in historical data is used as the reference lower limit of the freezing flow threshold. At the same time, the range resolution of the flow metering device and the adjustment accuracy of the control actuator are considered to ensure that the threshold is within the controllable range of control accuracy. The freezing flow threshold is corrected for safety margin by combining the lowest ambient temperature boundary of the operating environment and the lower limit of safe operating flow rate recommended by the equipment manufacturer, so that the freezing flow threshold is not lower than the safety lower limit. Finally, the value range of the freezing flow threshold is limited to the minimum effective flow rate allowed by the flow measurement and the minimum operating flow rate allowed by the equipment, and it is fixed as the trigger condition for freezing protection in the control logic.

[0064] D2: When the actuator output is equal to the boundary value of the set output range and the current flow error is greater than the preset flow deviation threshold, the smoothing weight and energy consumption weight in the weighting factor will be increased synchronously; when the actuator output meets the set output range or the current flow error is less than or equal to the preset flow deviation threshold, the smoothing weight and energy consumption weight in the weighting factor will remain unchanged. The formula for simultaneously increasing the smoothing weight and energy consumption weight in the weighting factors is as follows: ; ; in, For the updated smoothing weights, For the smoothed weights before the update, For the updated energy consumption weight, The energy consumption weight before the update This is the saturation adjustment coefficient; In this embodiment, the actuator output is a specific action parameter generated by the actuator according to the control command, which can directly change the state of the controlled object (such as flow rate, pressure, temperature). In this example, the valve opening is taken as an example. In this embodiment, the smoothing weight before the update is set to 0.5, the energy consumption weight before the update is 0.4, the saturation adjustment coefficient is 1.1, the actuator output is 80%, the actuator's set output range is 10%~80%, the flow error is 0.15 liters / second, and the preset flow deviation threshold is 0.1 liters / second. At this time, the actuator output is equal to the boundary value of the set output range of 80%, and the current flow error of 0.15 liters / second is greater than the preset flow deviation threshold of 0.1 liters / second, triggering the actuator's insufficient saturation tracking protection. It is necessary to increase the smoothing weight and energy consumption weight in the weight factors simultaneously. Substituting the smoothing weight before the update, the energy consumption weight before the update, and the saturation adjustment coefficient into the calculation formula for the simultaneous increase of smoothing weight and energy consumption weight, the updated smoothing weight is calculated to be 0.55, and the updated energy consumption weight is 0.44. At the same time, an alarm prompt is triggered on the monitoring interface to prevent excessive changes in the flow setting.

[0065] It should be noted that the adjustment of smoothing weight and energy consumption weight should be limited to the allowable range to form the set smoothing weight update result and energy consumption weight update result to suppress excessive changes in the setting in the next cycle; set alarms on the monitoring interface and record the timestamp, saturation direction, flow deviation and current weight to the event log to support operation traceability.

[0066] It should be noted that setting the flow deviation threshold includes confirming the flow measurement resolution, the minimum adjustable increment of the actuator, the maximum allowable flow rate, and the sampling period. The absolute baseline threshold is fixed as the larger of twice the flow measurement resolution and the minimum adjustable increment of the actuator, denoted as the absolute baseline. The proportional threshold is fixed at 2.5% of the flow setpoint and is updated in real time with the flow setpoint. The flow deviation threshold for the current period is the larger of the absolute baseline threshold and the proportional threshold, and the result is limited to a range not less than the absolute baseline threshold and not exceeding 10% of the maximum allowable flow rate.

[0067] D3: Collect the real-time temperature of the controlled object and determine whether the real-time temperature is greater than the safe temperature threshold. When the real-time temperature is greater than the safe temperature threshold, adjust the flow rate setpoint to the upper limit of the flow rate constraint, switch the control state to manual mode, and fix the manual output value to the safe opening degree until the temperature returns to the normal range. When the real-time temperature is less than or equal to the safe temperature threshold, keep the flow rate constraint unchanged.

[0068] In this embodiment of the application, taking the hot water outlet of the heat exchanger as an example, the safe temperature threshold is set to 95°C, the real-time temperature is 98°C, the lower limit of the flow rate in the flow constraint is 0.1 liters / second, the upper limit of the flow rate is 2 liters / second, and the safe opening degree of the valve is 80%. Since the real-time temperature is higher than the safe temperature threshold, the over-temperature protection is triggered. At this time, the control state is switched to manual mode, and the manual output value is fixed at the safe opening degree of 80% until the real-time temperature drops to 95°C, at which point the control state is switched from manual mode to automatic mode.

[0069] In one optional implementation, over-temperature protection can also employ a PID control over-temperature suppression method. When the real-time temperature approaches the safety threshold, the PID control parameters are adjusted to enhance temperature suppression. Taking a heat exchanger as an example, under normal PID parameters, when the real-time temperature is 93℃ (close to the safety temperature threshold of 95℃), the proportional parameter of the PID is automatically increased (e.g., from the usual 2 to 3) to make the flow rate adjustment more sensitive and quickly increase the flow rate to reduce the temperature. If the temperature still rises to 96℃, which exceeds the safety threshold, the system switches to manual mode, fixes the safety opening, and waits until the temperature drops below the safety temperature threshold before switching back to automatic mode and using the temporarily increased PID parameters to continue adjusting until the temperature stabilizes within the normal range. Then, the normal PID parameters and flow constraints are restored.

[0070] In another optional implementation, over-temperature protection can also employ an immediate intervention method based on thermal balance deviation. This involves simultaneously monitoring the inlet and outlet temperatures and flow rates of both the hot and cold fluids, and calculating the heat exchange between them. When the heat released by the hot fluid is significantly greater than the heat absorbed by the cold fluid, it indicates that the system's heat dissipation capacity is insufficient and the temperature may continue to rise. In this case, the cold fluid flow rate is immediately increased to 90% of its upper limit, and the thermal balance deviation is continuously monitored. If the deviation continues to widen or the temperature exceeds the safety threshold, the system switches to manual mode, fixing the valve's safe opening until the temperature drops to a safe range. Then, the control status is switched from manual to automatic mode.

[0071] In this embodiment of the application, step S500 outputs the adjusted flow constraint and weighting factor, which are also used as inputs for the optimization calculation in the next sampling period, including: The flow constraint and weighting factor adjusted in step S400 are output to the next sampling period. In the next sampling period, based on the adjusted weighting factor, combined with the load disturbance estimate of the next sampling period, the current variable of the filtered temperature output, the inlet temperature, and the current variable of the filtered flow output, a preliminary flow setpoint is generated. Based on the adjusted flow constraints, the initial flow setting constraints are applied, and simultaneously, the flow change slope constraints are applied to generate the flow setting value for the next sampling period. The current flow error is calculated based on the flow setpoint for the next sampling period and the current variable of the filtered flow output for the next sampling period, and then the current flow error is converted into the control output for the next sampling period.

[0072] Example 3, referring to Figure 1 This is a third embodiment of the present invention, which provides a dual closed-loop control system for temperature and flow, comprising: Data acquisition module: Reads inlet temperature, temperature measurement value, and flow rate measurement value; Preprocessing module: Filters the temperature and flow measurement values ​​to obtain the filtered temperature and flow output variables for the current period; First data calculation module: Calculates instantaneous heat transfer load based on the current variables of inlet temperature, filtered temperature output, and filtered flow rate output, combined with volumetric heat capacity parameters, and performs recursive updates to obtain the current cycle load disturbance estimate; The second data calculation module calculates the temperature tracking error based on the current cycle load disturbance estimate, the current variable of the filtered temperature output, the inlet temperature, and the current variable of the filtered flow output, and applies flow constraints to generate the flow setpoint. Control module: It uses the flow setpoint as the controller setpoint and calculates the control output based on the current variable of the filtered flow output; Data adjustment module: performs low flow freeze protection, actuator saturation tracking insufficiency protection, and over-temperature protection; adjusts flow upper and lower limits, smoothing weight, energy consumption weight, and manual control status.

[0073] Example 4, the fourth embodiment of the present invention, differs from the previous three embodiments in that: if the function is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, essentially, or the part that contributes to the prior art, or a part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods of the various embodiments of the present invention. The aforementioned storage medium includes: USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, optical disks, and other media capable of storing program code.

[0074] The logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as a sequenced list of executable instructions for implementing logical functions, and can be embodied in any computer-readable medium for use by, or in conjunction with, an instruction execution system, apparatus, or device (such as a computer-based system, a processor-including system, or other system that can fetch and execute instructions from, an instruction execution system, apparatus, or device). For the purposes of this specification, "computer-readable medium" can be any means that can contain, store, communicate, propagate, or transmit programs for use by, or in conjunction with, an instruction execution system, apparatus, or device.

[0075] More specific examples (a non-exhaustive list) of computer-readable media include: electrical connections (electronic devices) having one or more wires, portable computer disk drives (magnetic devices), random access memory (RAM), read-only memory (ROM), erasable and editable read-only memory (EPROM or flash memory), fiber optic devices, and portable optical disc read-only memory (CDROM). Furthermore, computer-readable media can even be paper or other suitable media on which programs can be printed, because programs can be obtained electronically, for example, by optically scanning the paper or other media, followed by editing, interpreting, or otherwise processing as necessary, and then stored in computer memory.

[0076] It should be understood that various parts of the present invention can be implemented in hardware, software, firmware, or a combination thereof. In the above embodiments, multiple steps or methods can be implemented in software or firmware stored in memory and executed by a suitable instruction execution system. For example, if implemented in hardware, as in another embodiment, it can be implemented using any one or a combination of the following techniques known in the art: discrete logic circuits having logic gates for implementing logical functions on data signals, application-specific integrated circuits (ASICs) having suitable combinational logic gates, programmable gate arrays (PGAs), field-programmable gate arrays (FPGAs), etc.

[0077] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A dual closed-loop control method for temperature and flow rate, characterized in that, include, Read the inlet temperature, temperature measurement value, and flow measurement value. Filter the temperature measurement value and flow measurement value to obtain the current variable of the filtered temperature output and the current variable of the filtered flow output. Combine the volumetric heat capacity parameter to calculate the current cycle load disturbance estimate. The temperature tracking error is calculated based on the current cycle load disturbance estimate, the current variable of the filtered temperature output, the inlet temperature, and the current variable of the filtered flow output. The weighting factor of the flow change is combined with the flow constraint to generate the flow setpoint. The flow rate setpoint is used as the controller setpoint, and the control output is calculated based on the current variable of the filtered flow rate output. Implement protection mechanisms, adjust traffic constraints, weighting factors, and manually control the status; The adjusted flow constraints and weighting factors are output and used as input for the optimization calculation in the next sampling period.

2. The temperature and flow dual closed-loop control method as described in claim 1, characterized in that, The steps for calculating the current cycle load disturbance estimate based on volumetric heat capacity parameters include: The current variables of the filtered temperature output and the filtered flow rate output, as well as the inlet temperature and volumetric heat capacity parameters are used as the input for calculating the instantaneous heat transfer load. The instantaneous heat transfer load is calculated based on the input quantities and volumetric heat capacity parameters. The current cycle load disturbance estimate is calculated using the current value of instantaneous heat exchange load.

3. The temperature and flow rate dual closed-loop control method as described in claim 2, characterized in that, The steps for calculating the temperature tracking error in conjunction with the weighting factor of flow rate changes, and applying flow constraints to generate the flow rate setpoint include: The predicted temperature is calculated by estimating the load disturbance, using the current variable of the filtered temperature output, and using the current variable of the inlet temperature and the current variable of the filtered flow rate output. The temperature tracking error is calculated based on the difference between the predicted temperature and the target temperature setpoint. Calculate the preliminary flow rate based on the temperature tracking error and the flow rate change weighting factor; Apply flow constraints to the initial flow rate and simultaneously apply flow rate change slope constraints to generate flow setpoints.

4. The temperature and flow dual closed-loop control method as described in claim 3, characterized in that, The steps for calculating the control output based on the current variable of the filtered flow output include: Read the flow rate setting and write it to the controller's setting port; Set the closed-loop activation port of the fixed controller to true and the manual activation port to false to ensure that the controller is in automatic closed-loop operation mode. The current flow error is calculated based on the flow setpoint and the current variable of the filtered flow output, and the current flow error is converted into a control output.

5. The temperature and flow dual closed-loop control method as described in claim 4, characterized in that, The steps for adjusting traffic constraints, weighting factors, and manually controlling the status include: Compare the current variable of the filtered flow output with the frozen flow threshold. When the current variable of the filtered flow output is less than the frozen flow threshold, raise the lower limit of the flow to the frozen flow threshold and increase the smoothing weight in the weighting factors. When the actuator output is equal to the boundary value of the set output range and the current flow error is greater than the preset flow deviation threshold, the smoothing weight and energy consumption weight in the weighting factor will be increased synchronously. When the actuator output meets the set output range or the current flow error is less than or equal to the preset flow deviation threshold, the smoothing weight and energy consumption weight in the weighting factor remain unchanged. Collect the real-time temperature of the controlled object, determine whether the real-time temperature is greater than the safe temperature threshold, and when the real-time temperature is greater than the safe temperature threshold, adjust the flow setpoint to the upper limit of the flow constraint, switch the control state to manual mode, and fix the manual output value to the safe opening degree until the temperature returns to the normal range. When the real-time temperature is less than or equal to the safe temperature threshold, the flow constraint remains unchanged.

6. The temperature and flow dual closed-loop control method as described in claim 5, characterized in that, The steps of outputting the adjusted flow constraints and weighting factors, and using them as input for the optimization calculation in the next sampling period, include: Based on the adjusted weighting factors, and combined with the load disturbance estimate for the next sampling period, the current variable of the filtered temperature output, the inlet temperature, and the current variable of the filtered flow output, a preliminary flow setpoint is generated. Based on the adjusted flow constraints, the initial flow setting constraints are applied, and simultaneously, the flow change slope constraints are applied to generate the flow setting value for the next sampling period. The current flow error is calculated based on the flow rate setpoint for the next sampling period and the current variable of the filtered flow rate output for the next sampling period, and the current flow error is converted into the control output for the next sampling period.

7. The temperature and flow dual closed-loop control method as described in claim 4, characterized in that, The conversion formula for converting the current flow error into control output is as follows: ； in, To control the output, As a proportional parameter, it determines the direct strength of the error's effect on the control quantity. The integral parameter is used to eliminate steady-state deviation by accumulating historical errors. As a differential parameter, the response is anticipated based on the rate of change of error, thereby improving dynamic performance. This is the current flow error. The flow rate error is from the previous sampling period. Indicates the first The error from each sampling is used for integration and accumulation. The sampling period.

8. A temperature and flow dual closed-loop control system, employing the temperature and flow dual closed-loop control method as described in any one of claims 1 to 7, characterized in that, include: Data acquisition module: Reads inlet temperature, temperature measurement value, and flow rate measurement value; Preprocessing module: Filters the temperature and flow measurement values ​​to obtain the filtered temperature and flow output variables for the current period; First data calculation module: Calculates instantaneous heat transfer load based on the current variables of inlet temperature, filtered temperature output, and filtered flow rate output, combined with volumetric heat capacity parameters, and performs recursive updates to obtain the current cycle load disturbance estimate; The second data calculation module calculates the temperature tracking error based on the current cycle load disturbance estimate, the current variable of the filtered temperature output, the inlet temperature, and the current variable of the filtered flow output, and applies flow constraints to generate the flow setpoint. Control module: It uses the flow setpoint as the controller setpoint and calculates the control output based on the current variable of the filtered flow output; Data adjustment module: performs low flow freeze protection, actuator saturation tracking insufficiency protection, and over-temperature protection; adjusts flow upper and lower limits, smoothing weight, energy consumption weight, and manual control status.

9. A computer device comprising a memory and a processor, wherein the memory stores a computer program, characterized in that, When the processor executes the computer program, it implements the steps of the temperature and flow dual closed-loop control method according to any one of claims 1 to 7.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements the steps of the temperature and flow dual closed-loop control method according to any one of claims 1 to 7.

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