Experimental heating system and device based on PID dynamic adjustment

Abstract

The invention belongs to the technical field of PID control, and discloses an experiment heating system and device based on PID dynamic adjustment, and the system comprises a visual experiment box body which is used for carrying out a visual experiment; the heating assembly is used for heating by using a parabolic column cast copper heater and a cuboid cast copper heater; and the control system adopts a PID (Proportion Integration Differentiation) control algorithm and realizes dynamic power adjustment of the heating temperature through a PLC (Programmable Logic Controller) Different power levels and decay heat conditions are simulated through the power regulation subsystem, and the contact melting influence of heating assemblies in different shapes on a melting experiment piece is analyzed.

Description

Technical Field

[0001] The present invention belongs to, but is not limited to, the technical field of PID control, and particularly relates to an experimental heating system and device based on PID dynamic regulation. Background Art

[0002] Core melting is a complex system process, and a large number of experimental studies have been conducted internationally to simulate the melting process. In a core melting accident, as decay heat continues to be generated, some core materials begin to melt to form a molten pool. During the development of the molten pool, it is surrounded by high-temperature steam or cooling debris, and a relatively thick solidified shell will form outside the molten pool, keeping the molten pool in its original state. Under the action of its own gravity, the high-temperature molten pool solidified shell will squeeze and melt with in-core components (such as support plates, fuel elements, etc.), and this melting is a typical contact melting process, and existing melting models cannot well simulate this process.

[0003] Through the above analysis, the problems and defects existing in the prior art are as follows:

[0004] Currently, in the experimental device for core melting in a reactor severe accident, it is mainly a melting test bench for rod bundles, but the contact melting process cannot be well simulated. And existing contact melting test benches mostly focus on the energy storage field, for the contact melting problem in a heating container. Due to different heating methods and melting processes, the research on contact melting in the energy storage field has little reference value for the contact melting phenomenon occurring in the reactor severe accident process. Summary of the Invention

[0005] Aiming at the problems existing in the prior art, the present invention provides an experimental heating system and device based on PID dynamic regulation.

[0006] The present invention is implemented as follows. An experimental heating system based on PID dynamic regulation, the system includes:

[0007] A visualization experimental box for conducting visualization experiments;

[0008] A heating component for heating using a parabolic column copper heater and a cuboid copper heater;

[0009] A control system that adopts a PID control algorithm and realizes dynamic power regulation of the heating temperature through a PLC module.

[0010] Furthermore, the exterior of the visualization experiment box is made of Q235 cold-rolled steel plate with a thickness of 1.5 mm by bending and welding; the surface color is "grayish white", and the surface is polished, phosphated, which can increase the corrosion resistance of the metal and the adhesion of the paint. The high-temperature spray coating is in the shape of large corrugations to prevent rust and corrosion; the interior material and process of the visualization experiment box adopt 1.5 mm high-quality 304 stainless steel, which is corrosion-resistant, oxidation-proof and processed with reinforcing ribs to prevent shaking and deformation. The bottom of the box is reinforced with channel steel and can bear a weight of 100 kg.

[0011] Furthermore, the visualization experiment box is made of 1.5 mm high-quality 304 stainless steel, which is corrosion-resistant, oxidation-proof and processed with reinforcing ribs to prevent shaking and deformation. The bottom of the box is reinforced with channel steel and can bear a weight of 100 kg; the box skeleton is made of materials such as angle steel or square steel to maintain the bearing strength of each surface inside and outside the box, and the coefficient of thermal expansion and contraction is retained to prevent the box from deforming and enhance its stability; the bottom of the box is raised, and four wheels with brakes are installed at the bottom of the equipment for easy operation.

[0012] Furthermore, the thermal insulation material of the visualization experiment box is 100 mm thick aluminum silicate rock wool with a thermal conductivity of 0.04 W / (m×K) to ensure that the surface temperature of the outer shell does not exceed 60°C; 100K encrypted aluminum silicate rock wool is used, which is non-toxic, harmless, pollution-free to humans and the environment, and has the characteristics of non-combustibility and strong heat insulation, and can maintain stable performance for a long time.

[0013] Furthermore, the density of the aluminum silicate rock wool is 80 - 150 kg / m 3 , the service temperature is 600°C, the thermal conductivity is 0.04 W / (m×K), the cross-sectional area of the conductor: 0.36㎡; the melting point of tin is known to be 231.9°C;

[0014] The formula for calculating the outer surface temperature of the plane thermal insulation layer is as follows:

[0015]

[0016] where T s represents the outer surface temperature of the plane thermal insulation layer; q represents the surface heat dissipation loss of the plane thermal insulation layer; λ represents the thermal conductivity of the thermal insulation material, taking 0.04 W / (m·K); δ represents the thickness of the thermal insulation layer, taking 0.1 m; T represents the outer surface temperature of the equipment heating element, taking 500°C; T a represents the ambient temperature, taking 20°C when the equipment is indoors according to the standard; α represents the heat transfer coefficient with the atmosphere, generally taking 11.63 W / (m 2 ·K);

[0017] Then calculate Equipment within the human - acceptable temperature range with a surface temperature greater than 60°C requires anti - scalding settings. After passing through the insulation layer, the temperature is 35.96°C, which is less than 60°C.

[0018] Furthermore, for the parabolic - column cast - copper heater and the cuboid cast - copper heater, 5 temperature - measuring points are arranged on the upper surface, with 3 in the center and 1 on each side; the cast - copper heater uses direct - current heating, and its lifespan is usually 3 - 5 years, but this is also affected by factors such as the environment, usage frequency, and maintenance.

[0019] The design of the two cast - copper heater schemes is as follows: For the parabolic - column heating component, the parabolic column is 20 cm long, 16 cm wide, and 4 cm high; the designed power is 1.5 KW, and two are made of copper material; multiple groups of thermocouples are configured on the surface of the heating component to observe the surface temperature.

[0020] For the cuboid heating component, the designed power is 1.2 KW, and two are made of copper material; multiple groups of thermocouples are configured on the surface of the heating component to observe the surface temperature.

[0021] Considering that the temperature of the cast - copper heater is relatively high, for anti - scalding considerations, the temperature will be displayed on the local temperature instrument, and there are high - temperature warning signs at obvious positions in the operation manual and on the test bench to prevent misoperation by test operators.

[0022] The heating element is made of all - copper casting, with 5 thermocouple holes and two heating power supports on it.

[0023] Quick - plug connectors for power and data are reserved on the back of the heating box and the control box. A multi - core connecting wire harness is configured between the control cabinet and the heating box for power supply and data transmission.

[0024] Furthermore, the control system selects Omron's precision tetrafluoro - shielded wire K - type contact thermocouple temperature sensor, which has strong temperature - resistance performance, is stable and reliable, is internally silver - plated for anti - interference, and is equipped with a 48 - channel inspection instrument data acquisition module. It preferably uses HMI, PLC control modules, and a power - adjustable power supply to collect and export temperature data under power adjustment required for the experiment.

[0025] Furthermore, the control system uses 220V, 50HZ AC incoming line, with a total power of 3 KW; according to the hardware layout position, it is divided into 48 K - type contact thermocouple temperature sensors, and 1 is arranged in the control box connected to the lower part of the temperature experiment box; the K - type contact thermocouple temperature sensor measures and collects the positions of the heater and the heated part; the control box temperature inspection instrument data acquisition module receives the sensor data for real - time data display; the PLC - side control software processes and displays the thermocouple temperature data on the heater in real - time, thus completing functions such as data acquisition and retention of the target temperature; the PC can communicate with the inspection instrument and the PLC control system by wire, and the communication distance is greater than 10 meters.

[0026] The specific implementation solutions are as follows:

[0027] (1) Automatic constant temperature: The thermostat can calculate the output power automatically by using PID according to the temperature value set by the user. When it is closer to the temperature set value, the output power is smaller, so as to achieve the purpose of constant temperature control and save energy and electricity.

[0028] (2) Over-temperature protection thermostat: The PID microcomputer intelligent built-in thermostat automatically tunes and calculates the output, with precise control. When the temperature exceeds the set value of the over-temperature protection thermostat, the heating power supply is automatically cut off.

[0029] (3) Heating tube control: Each heating tube adopts a non-contact SSR (solid state relay).

[0030] (4) The power regulation range of the power supply is 0 - 3KW; the programming resolution of the power supply is 0.1W; the display resolution is 1W; the user can program the output voltage and current of the power supply through the REMOTE interface (DB26) analog quantity on the rear panel of the power supply. At the same time, the REMOTE interface (DB26) on the rear panel also provides monitoring signals for the output voltage and current of the user; the ranges of the programming signal and the monitoring signal can be set to 0 - 5V or 0 - 10V through local control or remote communication;

[0031] (5) The analog output module of the PLC is connected to the REMOTE interface, and the output power of the power supply is controlled by controlling the change of voltage or current through the output analog quantity. The change curve of the analog quantity is the change curve of the power. Through the buttons on the HMI, the changed power and the time of power change are input; at the same time, the power and time can be displayed on the HMI for monitoring, and the power can be adjusted in gears and steplessly variable. The two adjustment methods can be connected in series for application;

[0032] (6) The output power is adjustable, and the adjustment formula is shown in the formula P(t) = P 0 +k*t. P(t) is the output power, P 0 is the initial power, k is the slope value, and t is the time. The P(t) power output value changing with time can be obtained.

[0033] Furthermore, the control method and characteristics of the control system are as follows:

[0034] (1) Adopt a 5-inch touch screen programmable PLC controller;

[0035] (2) It can record temperature data in real time, store up to 1000 days of data at most, support U disk export of documents, and can be directly opened on the computer side;

[0036] (3) The controller intelligently controls the temperature change data, dynamically adjusts the output power for energy saving, and ensures stable and energy-saving temperature.

[0037] (4) 99 temperature operation programs can be edited and set, and each program can run at 99 different temperatures and times.

[0038] (5) It is controlled in cooperation with an intermediate relay.

[0039] (6) The heating method set by the power curve is switched through a conversion knob to an adjustable power supply for self-heating, and the power can be automatically decreased according to a certain slope.

[0040] Another object of the present invention is to provide an experimental heating device based on PID dynamic regulation, which is used to implement the experimental heating system based on PID dynamic regulation.

[0041] Combined with the above technical solutions and the solved technical problems, the advantages and positive effects of the technical solution to be protected by the present invention are as follows:

[0042] First, the present invention uses the PID (Proportional-Integral-Derivative) control algorithm to dynamically regulate the experimental heating system. By real-time monitoring the temperature data of the heating component, the power output is adjusted to ensure that the temperature fluctuation range during the heating process is controlled within ±1°C. The PID controller automatically adjusts the output power according to the deviation between the set temperature and the actual temperature through a feedback loop, achieving the effects of fast response and stable control. Even under the conditions of load change or environmental condition fluctuation, high-precision temperature control can still be maintained.

[0043] The heating control system designed by the present invention combines dynamic power regulation technology, effectively optimizes the energy distribution and usage efficiency, and avoids excessive energy consumption. Through the modular power regulation subsystem, the power output is intelligently distributed according to the temperature and heat load requirements needed in different experimental stages, reducing energy waste. At the same time, the system automatically reduces the power output when approaching the target temperature, avoiding overshoot phenomena, significantly improving the energy efficiency ratio, and meeting the requirements of energy conservation and consumption reduction.

[0044] The present invention adopts the modular design concept, independently designs functional units such as heating components, control systems, and sensors, which is convenient for later component replacement and system upgrade. For example, the parabolic column cast copper heater and the cuboid cast copper heater can be independently disassembled, replaced, or upgraded. At the same time, the PLC module, inspection instrument module, etc. of the control system also support separate maintenance. The modular design not only improves the service life and reliability of the equipment, but also reduces the maintenance cost, significantly enhancing the convenience of equipment maintenance and operation efficiency.

[0045] The present invention simulates different power levels and thermal decay conditions through a power regulation subsystem to study the effects of parabolic cylindrical copper heaters and cuboid copper heaters in contact melting experiments. By adjusting the heater power curve and contact area, the differences in the contact melting efficiency, uniformity, and heat conduction characteristics of heating components of different shapes are compared and analyzed, providing accurate experimental data support and an important reference basis for optimizing heater design and subsequent process development.

[0046] Second, after the technical solution of the present invention is transformed, it can be used in contact melting experiments. It can simulate the contact melting processes of heating parts of various shapes under various heating methods. The experiments conducted can further analyze and study the relevant mechanisms of contact melting.

[0047] The technical solution of the present invention fills the technical gaps in the industry at home and abroad: Currently, most of the heating and melting experiments at home and abroad are fixed constant-power heating. This technology can, through self-programming, achieve various heating methods such as constant temperature, constant power, and linear power. The heating component will migrate downward as the material melts, which can well reflect the complex heating process of reactor core melting. In addition, it can also be used for experimental research on the relevant mechanisms of contact melting. Brief Description of the Drawings

[0048] Figure 1 It is the structure diagram of the box body provided by the embodiment of the present invention;

[0049] Figure 2 It is the side view of the box body provided by the embodiment of the present invention;

[0050] Figure 3 Schematic diagram of the air inlet and exhaust outlet provided by the embodiment of the present invention

[0051] Figure 4 It is the schematic diagram of the layout of the melting part and temperature measurement points in the heating box body provided by the embodiment of the present invention;

[0052] Figure 5 It is the schematic diagram of the control system provided by the embodiment of the present invention;

[0053] Figure 6 It is the control interface provided by the embodiment of the present invention;

[0054] Figure 7 It is the three-dimensional design of the parabolic cylindrical heating component provided by the embodiment of the present invention;

[0055] Figure 8 It is the three-dimensional design of the cuboid heating component provided by the embodiment of the present invention;

[0056] Figure 9 It is the actual experimental process (1) provided by the embodiment of the present invention;

[0057] Figure 10It is the actual experimental process (2) provided by the embodiments of the present invention;

[0058] Figure 11 It is the graph of the experimental heating power varying with time provided by the embodiments of the present invention;

[0059] Figure 12 It is the graph of the measured point temperature varying with time provided by the embodiments of the present invention;

[0060] Figure 13 It is the graph of the average heat flux density varying with time provided by the embodiments of the present invention.

[0061] Figure 1 、 2 In Figures 1, 2, 3, and 4: 1. Pressure gauge; 2. Thermometer; 3. Overlimit alarm; 4. Experimental bench; 5. Movable side door; 6. Observation movable door; 7. Power supply box; 8. Observation side window; 9. Air inlet hole; 10. Experimental box; 11. Exhaust hole; 12. Guide pipe; 13. Power supply cabinet; 14. Guide post; 15. Heating element; 16. Temperature-measuring thermocouple; 17. Melting element; 18. Workbench. Specific embodiments

[0062] In order to make the objectives, technical solutions, and advantages of the present invention clearer and more understandable, the present invention will be further described in detail below in conjunction with embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0063] The embodiments of the present invention provide an experimental heating system based on PID dynamic regulation, and the system includes:

[0064] Pressure gauge 1, thermometer 2, overlimit alarm 3, experimental bench 4, movable side door 5, observation movable door 6, power supply box 7, observation side window 8, air inlet hole 9, experimental box 10, exhaust hole 11, guide pipe 12, power supply cabinet 13.

[0065] A visual experimental box body 10 for conducting visual experiments;

[0066] A heating assembly for heating using a parabolic column copper heater and a cuboid copper heater;

[0067] A control system that adopts a PID control algorithm and realizes dynamic power regulation of the heating temperature through a PLC module.

[0068] The experimental heating system based on PID dynamic regulation of the present invention provides an experimental environment through the visualization experimental chamber 10, and is equipped with a parabolic cylinder cast copper heater and a cuboid cast copper heater for heating. The experimental chamber 10 is provided with a pressure gauge 1, a thermometer 2 and an overlimit alarm 3 to monitor the pressure and temperature changes of the experimental environment in real time and trigger an alarm when it exceeds the set range. The structure of the experimental chamber 10 includes a movable side door 5, an observation movable door 6 and an observation side window 8, which are convenient for experimental operation and real-time observation of the internal experimental state.

[0069] The heating component includes two cast copper heaters with different shapes, which are respectively suitable for different experimental requirements. The heating component introduces a power cord through the opening on the side wall of the experimental chamber to connect the power cabinet 13 and the power supply box 7, providing a stable power input for the heating element. The experimental chamber 10 is provided with an air inlet hole 9 and an exhaust hole 11 to adjust the gas flow in the experimental environment and ensure the stability of the experimental conditions.

[0070] The control system adopts the PID control algorithm and realizes dynamic power regulation through the PLC module. The thermometer 2 and the thermocouple sensor collect temperature data in real time. The PLC module calculates the current heating power requirement according to the PID algorithm and adjusts the power output of the heating component through the solid-state relay (SSR) of the power cabinet 13 to ensure stable regulation of the temperature within the set range.

[0071] The system supports multi-point temperature measurement and temperature curve setting. Users can set different temperature segments and heating times through the control interface and monitor the experimental process in real time. The temperature data can be stored and exported for post-experiment analysis. The overlimit alarm 3 provides an alarm signal when the temperature exceeds the safe range to ensure the safety and reliability of the experiment.

[0072] As Figure 1 、 Figure 2 、 Figure 3 shown, the outer part of the box body of the visualization experimental chamber 10 is made of 1.5 mm thick Q235 cold-rolled steel plate by bending and welding; the surface color is "gray-white", and the surface is polished, phosphated, which can increase the corrosion resistance of the metal, and the adhesion of the paint is treated. The high-temperature spray coating is in the shape of large corrugations to prevent rust and corrosion; the inner material and process of the box body of the visualization experimental chamber 10 adopt 1.5 mm high-quality 304 stainless steel, which is corrosion-resistant, oxidation-proof and processed with reinforcing ribs to prevent shaking and deformation. The bottom of the box body is reinforced with channel steel and can bear a weight of 100 kg.

[0073] The box body of the visualization experimental box 10 is made of high-quality 304 stainless steel with a thickness of 1.5 mm, which is corrosion-resistant and oxidation-proof, and is processed with reinforcing ribs to prevent shaking and deformation. The bottom of the box body is reinforced with channel steel and can bear a weight of 100 kg. The box body skeleton is made of materials such as angle steel or square steel to maintain the bearing strength of each surface inside and outside the box body, and the coefficient of thermal expansion and contraction is retained to prevent the box body from deforming and enhance its stability. The bottom of the box body is raised, and four wheels with brakes are installed at the bottom of the equipment for easy operation.

[0074] The thermal insulation material inside the box body shell of the visualization experimental box 10 is 100 mm thick aluminum silicate rock wool with a thermal conductivity of 0.04 W / (m·K) to ensure that the surface temperature of the outer shell does not exceed 60 °C. 100K encrypted aluminum silicate rock wool is used, which is non-toxic and harmless, pollution-free to the human body and the environment, and has the characteristics of non-combustibility and strong heat insulation, and can maintain stable performance for a long time.

[0075] The density of the aluminum silicate rock wool is 80 - 150 kg / m 3 , the service temperature is 600 °C, the thermal conductivity is 0.04 W / (m·K), the cross-sectional area of the conductor is 0.36 ㎡; the melting point of tin is known to be 231.9 °C;

[0076] The calculation formula for the outer surface temperature of the plane thermal insulation layer is as follows:

[0077]

[0078] Among them, T s represents the outer surface temperature of the plane thermal insulation layer; q represents the surface heat dissipation loss of the plane thermal insulation layer; λ represents the thermal conductivity of the thermal insulation material, taking 0.04 W / (m·K); δ represents the thickness of the thermal insulation layer, taking 0.1 m; T represents the outer surface temperature of the equipment heating element, taking 500 °C; T a represents the ambient temperature, which is taken as 20 °C according to the standard when the equipment is indoors; α represents the heat transfer coefficient with the atmosphere, which is generally taken as 11.63 W / (m 2 ·K);

[0079] Then the calculation belongs to the temperature range acceptable to the human body. Equipment with a surface temperature greater than 60 °C needs to be provided with anti-scalding settings, and the temperature after passing through the thermal insulation layer is 35.96 °C, which is less than 60 °C. Such as Figure 3As shown in the figure, the exhaust and safety module is provided with an air inlet and an air outlet. Both the intake valve and the exhaust valve are one-way valves. The inert gas filled in the experiment is helium. Therefore, the intake valve is arranged above the box body, and the exhaust valve is arranged on the lower side of the box body. When inflating, the air is discharged downward by the gravity of helium. To avoid the damage to the high-temperature power supply caused by the direct downward discharge of the heated high-temperature gas, a guide pipe 12 is connected to the exhaust valve to discharge the high-temperature gas from the side. When the pressure in the box body is higher than the set differential pressure threshold, it will automatically relieve pressure through the exhaust valve, so excessive high-pressure gas will not accumulate in the box body.

[0080] As Figure 4 Shown in the figure is the schematic layout diagram of the melting part 16 and the heating part 15 in the experiment. The melting part is fixed in the workbench 18 through pins, and the temperature-measuring thermocouple 16 is inserted according to the experimental needs. A through hole is opened in the middle of the heating part 15, and a guide rod 14 is inserted along the hole. The guide rod 14 is installed and fixed to the workbench through pins. The insertion of the guide rod can ensure the melting movement of the heating part in the vertical direction, prevent the heating part from slipping during the melting process, and enhance the stability of the experiment.

[0081] As Figure 7 、 8 As shown in the figure, for the parabolic column copper casting heater and the cuboid copper casting heater, 5 temperature measurement points are designed and arranged on their upper surfaces, with 3 in the center and 1 on each side; the copper casting heater adopts the DC heating method, and its service life is usually 3 - 5 years, but this is also affected by factors such as the environment, usage frequency, and maintenance;

[0082] The design of the two copper casting heater schemes is as follows: For the parabolic column heating component, the size is 20 cm in length, 16 cm in width, and 4 cm in height; the designed power is 1.5 KW, and two are made of copper materials; multiple groups of thermocouples are configured on the surface of the heating component to observe the surface temperature;

[0083] For the cuboid heating component, the designed power is 1.2 KW, and two are made of copper materials; multiple groups of thermocouples are configured on the surface of the heating component to observe the surface temperature;

[0084] Considering that the temperature of the copper casting heater is relatively high, for the consideration of preventing scalding, the temperature will be displayed on the local temperature instrument, and there are high-temperature warning signs at obvious positions in the operation manual and the test bench to prevent misoperation by the test operators;

[0085] The heating part is made of all-copper casting, with 5 thermocouple holes and two heating power supports on it;

[0086] Quickly pluggable connectors for power and data are reserved on the backs of the heating box body and the control box body. A multi-core connecting wire harness is configured between the control cabinet and the heating box body to supply power and transmit data.

[0087] As Figure 5As shown, the control system selects Omron's precision PTFE shielded wire K-type contact thermocouple temperature sensor, which has strong temperature resistance performance, is stable and reliable, has silver plating inside to resist interference, and is equipped with a 48-channel inspection instrument data acquisition module. The HMI, PLC control module, and power adjustable power supply are preferably selected to collect and export temperature data under power adjustment required for the experiment.

[0088] The control system uses 220V, 50HZ AC incoming line, with a total power of 3KW; it is divided into 48 K-type contact thermocouple temperature sensors according to the hardware layout position, and 1 is arranged in the control box connected to the lower part of the temperature test chamber; the K-type contact thermocouple temperature sensor measures and collects the positions of the heater and the heated part; the temperature inspection instrument data acquisition module in the control box receives the sensor data and displays the real-time data; the PLC-side control software processes and displays the thermocouple temperature data on the heater in real time, thus completing functions such as data acquisition and maintenance of the target temperature; the PC can communicate with the inspection instrument and the PLC control system by wire, and the communication distance is greater than 10 meters.

[0089] The specific implementation plan is as follows:

[0090] (1) Automatic constant temperature: The temperature controller can automatically calculate and output the power size by PID according to the temperature value set by the user. When it is closer to the temperature set value, the output power is smaller, so as to achieve the purpose of constant temperature control and save energy and electricity.

[0091] (2) Over-temperature protection temperature controller: The PID microcomputer intelligent built-in temperature controller automatically adjusts and calculates the output. The control is accurate. When the temperature exceeds the set value of the over-temperature protection temperature controller, the heating power supply is automatically cut off.

[0092] (3) Heating tube control: Each heating tube uses a non-contact SSR (solid state relay).

[0093] (4) The power adjustment range of the power supply is 0 - 3KW; the programming resolution of the power supply is 0.1W; the display resolution is 1W; the user can program the output voltage and current of the power supply through the REMOTE interface (DB26) analog quantity on the rear panel of the power supply. At the same time, the REMOTE interface (DB26) on the rear panel also provides monitoring signals for the output voltage and current of the user; the range of the programming signal and the monitoring signal can be set to 0 - 5V or 0 - 10V through local control or remote communication.

[0094] (5) The analog output module of the PLC is connected to the REMOTE interface. By outputting analog quantities to control the changes in voltage or current, the output power of the power supply is controlled. The change curve of the analog quantity is the change curve of the power. Through the buttons on the HMI, the changed power and the time of power change are input; at the same time, the power and time can be displayed on the HMI for monitoring, and gear adjustment of power and stepless variable speed adjustment of power can be realized. The two adjustment methods can be connected in series for application;

[0095] (6) The output power is adjustable, and the adjustment formula is shown in the formula P(t) = P 0 + k * t. P(t) is the output power, P 0 is the initial power, k is the slope value, and t is the time. The P(t) power output value changing with time can be obtained.

[0096] As Figure 4 shown, the control method and characteristics of the control system are as follows:

[0097] (1) Adopt a 5-inch touch screen programmable PLC controller;

[0098] (2) Can record temperature data in real time, store up to 1000 days of data, support exporting documents to a USB flash drive, and can be directly opened on the computer side;

[0099] (3) The controller intelligently controls the temperature change data, dynamically adjusts the output power for energy saving, and ensures stable temperature and energy saving;

[0100] (4) 99 temperature operation programs can be edited and set, and each program can run at 99 different temperatures and times;

[0101] (5) Cooperate with a intermediate relay for control;

[0102] (6) The heating method set by the power curve is through the switching of the conversion knob. Switch to the adjustable power supply for self-heating, and the power can be automatically decreased according to a certain slope.

[0103] The embodiment of the present invention provides an experimental heating device based on PID dynamic regulation, which is used to implement the experimental heating system based on PID dynamic regulation.

[0104] As Figure 9 、 10 shown, the actual experimental process provided by the embodiment of the present invention can better complete the relevant melting process and observe the temperature data in real time. The box body can select the constant temperature and the heating power size during constant temperature heating through the control panel, and set the alarm temperature and pressure on the alarm interface. When the temperature and pressure exceed the preset values, the alarm on the upper part of the box body will sound an alarm. Figure 11This is the power variation diagram during the experiment. During the experiment, the temperature values of 48 thermocouples can be observed in real time by controlling the cabinet panel. After the experiment, the operation data can be exported using a USB flash drive for processing. The resulting temperature vs. time effect diagram is as follows. According to the temperature values of each cross-section, the variation of the surface-averaged heat flux density of each plane with time can be obtained using Fourier's law of heat conduction, as follows Figure 12 , 13 shown. This experimental bench can better reflect the influence of the migration and solidification of the melt on the melting process during contact melting.

[0105] Based on the data in the experiment, the temperature characteristics of the contact melting process and the influence of the melt migration on subsequent melting can be intuitively presented.

[0106] The experimental heating system of the present invention adopts PID dynamic adjustment control to achieve high-precision temperature control and real-time data monitoring. The experimental cabinet is equipped with multiple temperature measurement points. The constant temperature and heating power can be selected through the control panel, and the alarm temperature and pressure are set at the same time. When the temperature or pressure exceeds the preset value during the experiment, the alarm on the upper part of the cabinet will sound an alarm to ensure the safe and stable operation of the experiment. During the experiment, the temperature data of multiple channels of thermocouples can be observed in real time through the touch screen interface, and the data can be exported for analysis after the experiment.

[0107] The heating system adopts two different-shaped heating components, a parabolic cylinder copper heater and a cuboid copper heater, to ensure uniform heating of the experimental materials. Thermocouple sensors are arranged at different positions of the experimental sample to collect the temperature change data of each area and transmit the data to the PLC control system for processing. The experimental chamber 10 is provided with an air inlet hole 9 and an exhaust hole 11 to control the gas flow in the experimental environment and avoid overheating or abnormal pressure affecting the experimental results.

[0108] The control system adopts the PID algorithm to dynamically adjust the power output through the PLC to ensure stable temperature control. The adjustment of the heating power is dynamically corrected based on the temperature data feedback to make the heating rate conform to the preset curve. The power variation is as Figure 11 shown. During the experiment, the system can adjust the power in real time to maintain a stable temperature, improving the repeatability and accuracy of the experiment.

[0109] During the experiment, the curve of the temperature data varying with time is as Figure 12 shown, and the trend of the temperature change of different temperature measurement points with time can be clearly observed. Further, by analyzing the temperature data of each temperature measurement point using Fourier's law of heat conduction, the surface-averaged heat flux density of each plane can be calculated, and the curve of its variation with time can be plotted, as Figure 13 shown, so as to deeply analyze the heat flux change law of the melting process.

[0110] This experimental bench can well simulate the contact melting process and observe the influence of the migration and solidification of the melt on the melting behavior. The fluidity, migration rate of the melt under high-temperature conditions, and the temperature distribution after solidification can all be intuitively presented through experimental data, providing experimental support for studying the heat transfer characteristics in the contact melting process.

[0111] Through this experimental device, the temperature characteristics of contact melting can be intuitively analyzed, and the influence of the melt migration on subsequent melting can be studied, providing an experimental basis for optimizing the control strategy of the melting process. The experimental data can be used to establish a more accurate heat transfer model, further enhancing the understanding of the melting process and providing theoretical support for related engineering applications.

[0112] As described above, it is only the specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any modification, equivalent replacement, and improvement made within the spirit and principle of the present invention by those skilled in the art within the technical scope disclosed by the present invention should be covered by the protection scope of the present invention.

Claims

1. An experimental heating system based on PID dynamic adjustment, characterized in that: include: a) Experimental box, which is composed of external cold-rolled steel plate and internal 304 stainless steel, with the external surface sprayed with plastic, the interior provided with insulation material, and the bottom reinforced with channel steel; b) a heating assembly comprising at least two cast copper heaters, each heater being provided with a plurality of thermocouple holes and power supply supports and supporting independent heating; c) Temperature monitoring module, including multiple K-type thermocouple sensors and patrol meter data acquisition module, for multi-point temperature data acquisition; d) Control system, using PID control algorithm, adjusts the power output of the heating component through the PLC control module, supports temperature data recording and program setting.

2. The experimental heating system according to claim 1, characterized in that: The insulation material of the experimental box is 100mm thick aluminum silicate rock wool, with a thermal conductivity of 0.04W / (m·K) and a density of 80-150kg / m 3 .

3. The experimental heating system according to claim 1, characterized in that: The heating assembly comprises a parabolic cast copper heater and a rectangular cast copper heater, the power of which is set to 1.5KW and 1.2KW respectively, and a plurality of thermocouple holes are arranged on the surface of the heater.

4. The experimental heating system according to claim 1, characterized in that: The temperature monitoring module includes an Omron K-type contact thermocouple sensor, supports at least 48 temperature measurement channels, and is connected to the inspection instrument data acquisition module for real-time data acquisition and storage.

5. The experimental heating system according to claim 1, characterized in that: The control system is equipped with a touch screen programmable PLC controller, which supports the setting of 99 temperature operation programs, each program contains up to 99 temperatures and time periods, and can realize dynamic power adjustment through HMI.

6. The experimental heating system according to claim 1, characterized in that: The control system is connected to the REMOTE interface via an analog interface to achieve voltage and current programming control. The power output curve of the power supply can be set to linear or nonlinear changes, and data transmission and power supply are performed via a multi-core connecting line.

7. An experimental heating method based on PID dynamic regulation, characterized in that: The following steps are involved: a) Conducting experiments in an experimental box, wherein the experimental box is made of cold-rolled steel plate outer shell, 304 stainless steel inner wall and aluminum silicate rock wool insulation material; b) Use parabolic copper heaters and rectangular copper heaters to provide heat sources, and configure multiple sets of thermocouples to monitor the surface temperature of the heaters in real time; c) Through the control system, the PID control algorithm is combined with the PLC module to dynamically adjust the power output according to the target temperature setting value to achieve temperature control.

8. The experimental heating method according to claim 7, characterized in that: The heating method comprises the following steps: a) Aluminum silicate rock wool is used as the insulation material to keep the external temperature of the box below 60°C by reducing the thermal conductivity; b) According to the equipment outer surface temperature formula, the heat dissipation stability of the experimental box is ensured by adjusting the thickness of the insulation layer and the heat loss parameters.

9. The experimental heating method according to claim 7, characterized in that: The method comprises the following steps: a) Use K-type thermocouple sensor to measure the temperature of the heater surface and the heated part; b) The temperature data is transmitted to the PLC module through the inspection instrument acquisition module, and the power output change is calculated in real time by the PID control algorithm; c) Set the power curve and temperature change curve through the touch screen programming control interface, and monitor and adjust the heating process in real time through the HMI.

10. The experimental heating method according to claim 7, characterized in that: The control system comprises the following steps: a) Connect the power curve of the power supply to the PLC module through the analog interface to achieve the programmed output of voltage and current; b) Set the dynamic change formula of output power, adjust the power change slope and time parameters through HMI to achieve linear or nonlinear power output; c) Record temperature data during the experiment, support multi-stage setting of temperature operation program and long-term storage and export functions.

Images