Temperature control paperless recorder

2020-12-22 14:45:55

Keywords: temperature control, data logger

I. Overview:

The temperature control split recorder is widely used in the fields of chemical industry, thermoelectricity, petrochemical, pharmaceutical, metallurgy, machinery, electric furnace, heat treatment, food, papermaking, scientific research and experiment. For elemental analysis and determination, it is used for heating during heat treatment such as sintering, quenching, annealing, and tempering of general small steel parts. The high-temperature furnace can also be used for high-temperature heating such as sintering, dissolution and analysis of metals and ceramics. It is especially suitable for coal quality analysis and testing. In the determination of coal ash, volatile matter and analysis of coal ash composition.

The temperature control recorder accurately controls the temperature of various actuators, SCRs, solid state relays, AC contactors, electric control valves, pneumatic control valves, solenoid valves, etc.

2. System architecture of temperature control split paperless recorder  

Innovative application [True Color Human-Machine Interface Touch Screen] to form Yudian [Split Paperless Recorder Combining True Color Human-Machine Interface Touch Screen + Smart Meter] completely changed the structure of the paperless recorder and entered the category of computer applications.

AI-2070 true color man-machine interface touch screen, 7-inch screen (16:9), connected to AI series instrument; optional 2, 4, 6, 12, 18, 24 and 36 channel software system; 2G capacity U disk or SD card.

AI-3043S true color man-machine interface touch screen, 4.3 inches (16:9), connected with AI series instrument; optional 2, 4, 6, 8 channel software system;

AI-2010C multifunctional true color man-machine interface paperless recorder, 10.2 inches (16:9), connected to AI series instruments; optional 2, 4, 6, 12, 18, 24 and 32 channel software systems;

On the basis of AI series meters, the [True Color Human-Machine Interface Touch Screen] is added to realize the centralized display operation and paperless recorder functions, and the system appearance is more advanced. A photoelectrically isolated RS485 communication interface is used between the instrument and the touch screen. Each temperature adjustment instrument works independently. The bus connection respects tradition and leads the trend, and meets the design requirements of industrial control products of "centralized operation and dispersed danger". The RS485 bus is the simplest, most stable, and most mature industrial bus structure. It is an economical and traditional industrial bus method for device networking. RS485 has simple connection and communication distance greater than 1.2Km, which can be reliably used in industrial sites.

The system is simple and easy to use and saves investment: from design, installation, commissioning to normal production operation and maintenance, it shows considerable superiority. The RS485 fieldbus system is a fully digital, two-way, multi-station communication system between the input and output of the field instrument and the control system. A pair of twisted pair or a cable can usually be connected to multiple devices, so the amount of cables, terminals, slot boxes, and bridges is greatly reduced, and the workload of connection design and joint calibration is also greatly reduced. Allows users to save a lot of cable and compensation wire costs. In addition, in the design process, the actual needs of on-site technology and operators are fully considered. The user does not need computer professional technical knowledge at all. This requires understanding the requirements of the process for measuring points and control points; select the instrument module model and master the instrument module calmly The function is all right, simple and convenient, just buy it and use it.

Convenient application and free control: it can be applied and freely controlled after power on. Real-time display paperless recorder with touch function. Cooperate with the lower AI series acquisition and display control module to realize data monitoring, PID adjustment or program formula adjustment, remote hand operator, switch output and other functions; realize the automatic identification of the AI series product RS485 bus intelligent controller. Terminal, the perfect combination of AI series display control module and HMI touch screen. The seemingly simple hardware and software are combined to develop a monitoring system combination product with low price and convenient application. Let the system combination and free control be in your hands, leaving the convenience to the user and the difficulty to the manufacturer.

Especially the oven heating control system: it consists of three parts: adjustment control, measurement record, and power supply device. The temperature controller and nickel-chromium-silicon-nickel thermocouple are used together. The resistance furnace measurement and control are equipped with AI artificial intelligence digital program adjustment. The small control cabinet is equipped with an over-temperature protection output to control the power-off of the AC contactor. The temperature control adopts a phase-shift trigger to control the thyristor or zero-crossing to trigger the thyristor circuit and current transformer, terminal board and other electrical element. The temperature control instrument of the temperature controller uses an AI artificial intelligence regulator. The thermocouple converts the temperature in the furnace into a level signal, which is calculated by the self-tuning of the single-chip microcomputer control parameter in the temperature control instrument, and the control output is sent to the phase shifting module. The adjustment of the phase shift angle changes the size of the thyristor conduction angle to control the average heating power of the electric furnace. When it is close to the set temperature, the furnace is heated intermittently and finally maintains the set temperature in the furnace. The constant temperature time control is heated according to the set program, and the program is heated according to the format of [temperature-time-temperature]. It maintains precise temperature control during the constant temperature period. After entering the holding state, the temperature fluctuation is small; it has a variety of thermostats Available

The measurement record adopts a split paperless recorder ①It can reduce visual reading and human operation errors, and greatly improve work efficiency; ②It is equipped with an over-temperature alarm function record; it improves safety and reliability; ③It is equipped with 50-segment heating Program, you can set the heating process according to different experimental requirements; ④Select the instrument equipped with communication function to quickly connect the bus-type paperless recorder. ⑤The AI split paperless recorder is a transformation and upgrade of the old product.

3. Application of temperature control split paperless recorder

1. Temperature recorder function

The AI temperature adjustment instrument of each heating furnace can be used when connected to the RS485 communication line; flexible application: the temperature adjustment recorder can be connected to 2, 4, 6, 8, 12, 16, 18, 22, 32 AI temperature adjustment instruments Class; Freely edit and select the AI temperature adjustment instrument model on the recorder, write the heating furnace equipment number such as: [TIC-101]; The types of connected instruments not only include various temperature PID artificial intelligence adjustments, but also adjust pressure and flow. Electricity and other functions; any combination of AI products, you can choose to operate functions of intelligent regulator, hand operator, single or multiple display alarm, flow totalizer or switch input and output module;

Temperature adjustment: Each heating furnace AI intelligent instrument performs PID control function independently, and each AI adjustment and measurement unit can independently display operation: measured value, given value, set parameter, automatic manual switch without disturbance, adjust manual output value, The program curve can be set in the digital paperless recorder, and the programmed program formula is transmitted to the temperature control program instrument; start/run/stop program; precisely adjust the thyristor shift trigger and regulating valve of each electric heating furnace to control temperature. The system can be expanded at any time.

Data recording: Insert a U disk into the temperature-regulated split paperless recorder, with 2G as standard, and record data for several years. In the development process, the AI split temperature adjustment paperless recorder has continuously enhanced its software and data storage functions to adapt to the needs of the scene. The default automatic export U disk interval is 480 minutes (8 hours); the user can also set the export time interval at will;

If you need to remove the U disk, you must click the [Save Now] button, and everything will be transferred to the U disk immediately. Real-time export data to a USB flash drive; import the data format of the Excel report in CSV into the USB flash drive, and back up the data to the computer and open it directly with the CSV Excel report.

2. Installation method

The split-type paperless recorder is [upper computer-true color man-machine interface touch screen] and [lower computer-AI temperature adjustment instrument]; [upper computer-true color man-machine interface touch screen] adopts panel installation, [lower computer-AI temperature Adjustment instrument] Optional panel or guide rail installation mode. AI temperature adjustment instrument bus connection, arranged by address, AI instrument runs independently, does not interfere with each other, and can display operation when power is on; touch screen COM1 communication port uses [super Category 5 shielded twisted pair] 2 wires to connect to the communication port of AI instrument A/B end; COM2 communication port has random printing function.

3. Boot interface

The screens are: [Data screen] [Real-time curve bar graph] [Flow chart] [History curve] Quickly return to the [instrument screen] channel of a single instrument. Press [Previous Page] [Next Page] on similar pages; at the same time it has [Report], [Alarm], [Instrument Settings], [Record, Export Settings] functions

The regulation and control instrument adopts hyperbolic operation mode during operation, and it can see the comparison between the measured value (PV) and the set value (SV) in real time, the upper and lower limits or the positive and negative deviations, generate an alarm and prompt text promptly, and the switch output of the field instrument module Connect the protection interlock function or alarm buzzer.

4. Customized process flow chart-touch control motor start and stop [dry contact switch input and output]

Use vivid graphics to describe the on-site production process, which is the epitome of the entire industrial site. It is not just a picture, it has control buttons and real-time data displayed at the same time, so that the operator has a very intuitive remote control. Software editing can also realize the function of soft PLC switch output, clock timing control, and switch output counting function.

The button in the flowchart is available: the control button is connected to the AI-3013D5 switch 8-way relay output module, and the address is set to 33 (software has been customized). The switch button in the flowchart can control the start and stop of 4 motors; connect to AI -3011D5 switch quantity 8 input dry contacts, the address is set to No. 37, to display the operating status of the device; click the data box in the flowchart such as: [TIC-101] to return to the [real-time view] channel. According to customer requirements, the flow chart can be customized or other requirements can be handled as appropriate. Application of the inverter control loop on the flowchart: The AI-3013D5 switch output module can be directly controlled on the flowchart interface to control the [start and stop] of the inverter; the manual/automatic control instrument PID adjustment makes the inverter increase and decrease speed control.

5. Description of host model of heating furnace adjustment instrument

AI-808P function enhanced 30+20 segment program control artificial intelligence regulator;

AI-708P type 30+20 program control artificial intelligence regulator;

AI-518P type 30-segment program artificial intelligence thermostat;

AI-808 function-enhanced artificial intelligence regulator (0.1-level precision / manual output / external reference / valve servo);

AI-518/708 artificial intelligence regulator (0.3/0.2 level accuracy/0.24 second control cycle/multiple input/modularity);

AI-708J type manual operator/servo amplifier (modularization/delayable deviation alarm function/hand automatic slow change function);

AI-519/719 artificial intelligence regulator (0.3/0.1 grade accuracy, soft start on power-on/parameter table of V7.5 version);

6. AI intelligent temperature meter debugging

AI intelligent temperature regulator: It is the core part of the heating furnace temperature control system. The AI instrument pioneered the use of the platform concept, turning a very professional digital adjustment instrument into a platform-based design product. The AI artificial intelligence adjustment algorithm is a new type of algorithm that uses fuzzy rules for PID adjustment. When the time, fuzzy algorithm adjustment is used to eliminate the PID saturation integral phenomenon. When the error becomes smaller, the improved PID algorithm is used for adjustment, and part of the characteristics of the controlled object can be automatically learned and memorized in the adjustment to optimize the effect.

Self-tuning method: Since the self-tuning is executed by position adjustment, after 2 to 3 oscillations, the internal microprocessor of the instrument analyzes the period, amplitude and wave type of the oscillation generated by the position control to automatically calculate M 5, P, t and other control parameters. It has the characteristics of no overshoot, high precision, simple parameter determination, and good control effect for complex objects. When the program instrument is self-tuning, please set the first program to the common temperature or the highest temperature self-tuning. . . .

In the process of use, the AI regulator combines PID adjustment, self-learning and fuzzy control technology to realize the self-tuning/adaptive function, and precise adjustment without under-adjustment, and its performance is far better than traditional PID regulators.

Four, industry application cases

In many temperature controls, instead of pure temperature control, real-time data recording is required. The temperature control recorder [split paperless recorder] is used to organically combine the regulating instrument and the recorder to provide the best control and Recording performance solves the problems in practical applications.

The development direction of today's ceramic kilns is from the roller table, automation, coal gasification, light-duty, and large-scale development proposed in the past to green (environmental, energy-saving and intelligent) kilns. The standard of green kiln is low consumption (energy-saving), low pollution (environmental protection), low cost and high efficiency. The direction of efforts to achieve green kilns is to study new automatic control methods and methods, reduce power consumption and noise of kiln fans, research advanced burners, use new refractory materials and coatings, and establish exhaust gas purification research and testing centers. The goal of achieving a green furnace is to further reduce fuel consumption by 10%-20%, increase furnace thermal efficiency by 10%-20%, reduce power consumption by 10%-30%, and reduce noise and smoke to a greater extent. This puts forward higher technical requirements for the original furnace control methods and methods. The current furnace control method has been developed from manual control in the 1990s to intelligent control; from decentralized control to distributed control; the temperature has changed from the previous pure PID adjustment method to the PID plus fuzzy control adjustment method; From conventional control to linear speed control with frequency conversion technology, etc. As the length of the kiln increases (150-250m), the production output increases (6000-1500m2/day), the firing cycle shortens (60-30min) and other factors change. In addition, the kiln control target is a multi-input, multi-input The output, multi-variable, large lag, and non-linear take-off change make our past control methods less and less suitable for the development requirements of the current furnace. With the development of computer technology and electronic technology, computer control technology has gradually replaced traditional control technology.

The AI artificial intelligence adjustment algorithm is a new type of algorithm that uses fuzzy rules for PID adjustment. When the error is large, the fuzzy algorithm is used to adjust to eliminate the PID saturation integral phenomenon. When the error becomes smaller, the improved PID algorithm is used for adjustment. And can automatically learn and memorize part of the characteristics of the controlled object during the adjustment to optimize the effect.

In the process of use, the AI regulator combines PID adjustment, self-learning and fuzzy control technology to realize the self-tuning/adaptive function, and precise adjustment without under-adjustment, and its performance is far better than traditional PID regulators.

The use of temperature control recorder organically combines the adjustment instrument with the recorder, provides the best control and recording performance, and solves the problems in practical applications.

1. Application of high temperature furnace

The laboratory high-temperature furnace is commonly known as the muffle furnace: it is a commonly used industrial electric furnace and a universal heating equipment. It can be divided into box furnaces, tube furnaces and crucible furnaces. The furnace wall is made of square refractory and thermal insulation materials, and an electric heating wire is wound on the furnace wall. The muffle furnace is a periodic operation type, mainly used for

Coal, electric power, chemical industry, building materials, metallurgy, scientific research and other departments and laboratories of universities and colleges do elemental analysis and determination.

2. Periodic resistance furnace applications: box furnace: trolley furnace (divided into self-propelled and traction), used for annealing, and the workpiece is cooled with the furnace after heating; pit furnace: bell furnace (mainly used for Annealing, the heating mantle can be lifted and moved); Rotary drum furnace: sealed box furnace (also known as multi-purpose furnace, can be carburized, smooth quenching, carbonitriding and other heat treatment processes;

3. Application of tunnel oven heating control system: The annealing furnace is mainly composed of a roller drive system and a temperature control heating system. Zone heating. The heating body is made of iron-chromium-aluminum materials, the operating temperature is 0~1100℃, the nickel-chromium-nickel-silicon thermocouple is used for temperature measurement, and the heating power supply is a low-voltage 380V three-phase power supply. The heating bodies are connected in a star shape, and they are arranged on the top and bottom of the furnace. The new temperature control heating system is composed of AI-808PAI5X3L1L1S4 program temperature control regulator, three-phase SCR trigger circuit and AI-2070 split paperless recorder and other low-voltage control components.

4. Application of automatic chemical drying oven: steam circulation oven products have reached the advanced level at home and abroad after many upgrades, with an average thermal efficiency of more than 70%, using axial fan circulation, equipped with an automatic constant temperature system, and adopting AI-2070 Paperless recorder intelligent program temperature control records the data record of the whole process. It uses steam or electricity as the heat source, and heats the air by convective heat exchange to the heat exchanger with an axial flow fan. The laminar flow of hot air passes through the drying pan and transfers heat to the material. Fresh air is replenished from the air inlet, and the waste wet air is discharged from the temperature exhaust port. The fresh air is constantly added and the waste wet air is discharged, so as to maintain the proper temperature and relative humidity in the oven. The biggest feature of this series of ovens is that most of the heat circulates in the oven, and the entire circulation process is closed, which enhances sensing and saves energy.

5. Application of vacuum heat treatment furnace: Vacuum heat treatment furnace is one of the four basic industries of mechanical manufacturing (casting, forging, heat treatment, welding), and a very important key process in the manufacturing process of mechanical products. The intelligent program temperature control of the vacuum heat treatment furnace, the furnace door opens automatically, the trolley automatically moves, the furnace fire movement state,

As we all know, the quality of heat treatment depends on the heat treatment process and equipment. Advanced heat treatment equipment not only can correctly complete the heat treatment process, but also has the functions of energy saving and pollution prevention, so as to realize energy saving, precision and green heat treatment.

The electric heating element in the vacuum heat treatment furnace is spiral, and the back wall and furnace top are equipped with thermocouples. The AI-2070 paperless recorder is used to control the temperature of the intelligent program to control and record the furnace temperature and vacuum degree. These data are stored in the AI-2070 paperless recorder database.

6. Application of thyristor temperature controller: Industrial resistance furnace is a common industrial controlled object with nonlinearity, large hysteresis, and large inertia. The resistance furnace is widely used in the sample melting in the laboratory, the segmented heating and cooling of the workpiece in the heat treatment, etc. Different types of PID regulators can be selected to control the temperature in an appropriate range according to the different requirements of the process for temperature accuracy.

For resistance furnaces that require constant temperature control instead of temperature recording, a digital temperature display regulator with PID adjustment is used to display and adjust the temperature, and output 0~10mA as a DC signal input to control the thyristor voltage regulator or trigger board to change the thyristor The output power can be adjusted by the conduction angle of the tube, which can fully meet the requirements, with low investment cost, convenient and intuitive operation and easy maintenance.

For complex control systems that require high temperature control accuracy, multi-point temperature control and recording, it is ideal to use AI-2070 paperless recorder. The control system composed of input and output modules replaces the previous multiple digital temperature indicating regulators, which not only realizes the equipment It’s upgraded and fully compatible with previous equipment.

Five, concluding remarks

AI temperature split paperless recorder has a wide range of applications, covering industry, agriculture, transportation, science and technology, environmental protection, national defense, culture, education and health, and people’s lives. Its products have been mainly used in chemical, thermoelectric, petrochemical, pharmaceutical, metallurgy, machinery, Electric furnaces, heat treatment, food, papermaking, scientific research and experiments, etc. Has a good market demand and huge development potential. Specific applications such as: independent electric furnace, furnace control, various continuous production processes, more suitable for batch control, discontinuous production of flow accumulation, quality inspection and other occasions that require intermittent display records. The system implements the flexible design concept. The signal types of all input channels can be set and changed as needed. The storage time of each recorded data can be set according to the requirements of the recorded data sampling interval, and it can be easily transferred to the removable hard disk. The system has a long-term stable operation record on site and has a good user reputation. It is a mature, reliable and trustworthy product.