A roasting kiln body roasting digital twin system and a control method

Abstract

The present application is aimed at the problems existing in the current rotary kiln monitoring and control technology, and provides a roasting kiln body roasting digital twin system and a control method. The system comprises 1) field monitoring instruments: including various types of field temperature, pressure, flow and heat value analysis instruments; 2) field control equipment: including various types of field regulating valves, shut-off valves, frequency conversion equipment; 3) signal isolation conversion system: including isolators, circuit breakers and their cabinets; 4) computer system: including PLC system, cabinet, switch, module, database. The present application constructs a complete kiln body 3D model, and adopts advanced monitoring means to monitor the kiln temperature, pressure and kiln skin temperature in real time, establishes a mathematical model to realize data simulation of the kiln process parameters. And constructs an intelligent algorithm to control the coal gas, air and kiln body rotating speed, realizes the control of the key parameters in the kiln, and then completes the roasting digital twin simulation, realizes the intelligent monitoring, prediction and control of the roasting state.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of intelligent factory construction of the steel industry, and particularly relates to a kiln body roasting digital twin system and a control method. BACKGROUND

[0002] With the rapid development of the domestic chain grate-rotary kiln pelletizing process, the normal operation of the chain grate, rotary kiln and ring cooler, the three main machines, is related to the operation efficiency of the entire production line. Among them, the gas flow, fuel combustion, heat transfer and material movement in the rotary kiln have a great influence on the roasting products. However, the traditional control system is limited by the detection and control conditions, and can only realize the PID control of the roasting gas in the rotary kiln, and there is no intelligent control and simulation system.

[0003] Digital twin is a simulation process integrating multi-discipline, multi-physical quantity, multi-scale and multi-probability by making full use of physical model, sensor update, operation history and other data, and completing mapping in a virtual space, so as to reflect the whole life cycle process of the corresponding entity equipment. If this technology is used to monitor important parameters of the rotary kiln and simulate data of process parameters in the kiln, the production technology and production efficiency of the rotary kiln will be further improved. SUMMARY

[0004] The present application is aimed at the problems existing in the present rotary kiln monitoring and control technology, and provides a roasting kiln kiln body roasting digital twin system and a control method. The present application constructs a complete kiln body 3D model, and uses advanced monitoring means to monitor the kiln temperature, pressure and kiln skin temperature in real time, establishes a mathematical model to realize data simulation of process parameters in the kiln. And an intelligent algorithm is constructed to control coal gas, air and kiln body speed, to realize the control of key parameters in the kiln, and then complete the roasting digital twin simulation, realize the intelligent monitoring, prediction and intelligent control of the roasting state.

[0005] One of the technical solutions of the present application is a roasting kiln kiln body roasting digital twin system, which comprises:

[0006] 1. Field monitoring instruments: including various field temperature, pressure, flow and heat value analysis instruments;

[0007] Specifically, it includes a coal gas heat value instrument, a coal gas flow meter, a coal gas pressure transmitter, an air gas flow meter, an air pressure transmitter, a flame detector, a burner front coal gas pressure transmitter, a kiln head colorimetric temperature instrument, a kiln head infrared temperature instrument, a kiln head S-type thermocouple, a kiln head pressure transmitter, a kiln tail S-type thermocouple, a kiln skin infrared temperature instrument and a kiln body rotation speed instrument.

[0008] 2. Field control equipment: including various field regulating valves, shut-off valves and frequency conversion equipment;

[0009] Specifically, it comprises a gas automatic igniter, a gas low-pressure quick cut-off valve, an air flow electric regulating valve, a gas flow electric regulating valve, and a kiln body rotation speed frequency converter.

[0010] 3. Signal isolation conversion system: comprising an isolator, a circuit breaker and its cabinet;

[0011] 4. Computer system: comprising a PLC system, a cabinet, a switch, a module, and a database;

[0012] Among them, the signals of the field monitoring instruments and the field control devices are sent to the computer system through the signal isolation conversion system, and the instruction signals of the computer system are sent to the field control devices through the signal isolation conversion system.

[0013] The second technical solution of the present application is the control method of the above-mentioned roasting kiln body roasting digital twin system, which comprises monitoring, intelligent analysis, control, feedback and abnormal alarm, and the following steps:

[0014] Step 1: constructing a 3D model of the kiln body and the gas-air pipe network

[0015] According to the specific structure of the kiln body, a 3D model of the kiln body and the gas-air pipe network is constructed;

[0016] Step 2: obtaining the data of the field detection instruments

[0017] Step 3: data storage, and making a display on the 3D model of the kiln body and the gas-air pipe network

[0018] The data of the field detection instruments is stored in the SQL database of the computer system, and the data of the field detection instruments is displayed in the 3D model;

[0019] Step 4: roasting temperature fitting in the kiln

[0020] 4.1 Constructing a kiln image coordinate system xy, reading the kiln tail position (x1, y1) kiln temperature TE4, kiln head position (x2, y2) kiln temperature TE2, and position (x3, y2) kiln temperature TE3;

[0021] 4.2 In the same coordinate system xy, a kiln skin temperature image is constructed according to the infrared temperature measurement of the kiln skin;

[0022] 4.3 The kiln temperature solving process:

[0023] The kiln tail kiln internal and external temperature difference is:

[0024] Δt 尾 = TE4-TE 54 (1)

[0025] The kiln head kiln internal and external temperature difference is:

[0026] Δt 头 = (TE2-TE 52 + TE3-TE 53 ) / 2 (2)

[0027] Kiln temperature:

[0028] t 内(x,y) = (Δt 头 - Δt 尾 )*(y-y1) / (y2-y1)+t 外(x,y) (3)

[0029] Solving the kiln temperature t 内(x,y) of each coordinate point in turn, generate the kiln temperature image;

[0030] Wherein, TE54, TE53, TE52 are the local temperature points of the kiln skin temperature image

[0031] Step 5: build kiln 3D firing twin

[0032] The t 外(x,y) collected by the kiln skin temperature TE-5ABC, the kiln temperature t 内(x,y) collected by the kiln head color temperature instrument, and the image are respectively constructed in the kiln 3D model to build three-dimensional twin and display;

[0033] Step 6: flame shape fitting

[0034] The flame shape is extracted from the temperature image collected by the kiln head color temperature instrument and displayed in the 3D model. At the same time, the flame shape information and corresponding coal gas, air, and kiln body speed data are stored in the graphic database;

[0035] Step 7: flame shape analysis

[0036] The length and width of the flame are analyzed and compared with the high-quality flame shape in the graphic database to determine the quality of the flame shape;

[0037] Step 8: adjust the amount of coal gas and air to stabilize the flame shape

[0038] According to the determined quality of the flame shape and the measured coal gas calorific value by the coal gas calorimeter, adjust the coal gas control parameters to achieve high-quality firing.

[0039] Further, the above control method further comprises step 9: accident state analysis, alarm, interlocking; set low pressure alarm for all pressure measurement values, wherein the low pressure shutdown quick cut-off valve is set for the coal gas pressure transmitter before the burner to prevent production accidents. BRIEF DESCRIPTION OF DRAWINGS

[0040] Figure 1 , setting diagram of field monitoring instrument and field control equipment

[0041] Figure 2 , a diagram showing the system structure of the present invention;

[0042] Figure 3 : Flowchart of the control method of the present invention;

[0043] Figure 4 : Schematic diagram of temperature image fitting in kiln.

[0044] Among them, 1. Chain grate, 2. Main transmission device, 3. Rotary kiln power station control system, 4. Coal injection burner. DETAILED DESCRIPTION

[0045] Example 1

[0046] A digital twin system solution for roasting kiln body is:

[0047] 1. If Figure 1 As shown, for the pelletizing project, the raw material is preheated by the grate and then put into the kiln for roasting. The heat source of the kiln comes from the heat generated by the combustion of the burner gas. During the roasting process, the hydraulic system drives the kiln to rotate to ensure that the material is evenly heated.

[0048] Temperature, pressure, flow, and calorific value instruments are installed at key locations within the kiln body to monitor production conditions in real time. On-site regulating valves and shut-off valves are also installed to regulate and control gas and air. Signals from on-site monitoring instruments and control equipment are transmitted to a computer system via a signal isolation system, creating a 3D model of the kiln body. Simultaneously, intelligent software analysis and calculations are used to control on-site control equipment, adjust gas, air, and rotation speed parameters, and achieve intelligent simulation of pellet roasting control.

[0049] 2. If Figure 2 As shown, the system consists of two parts: hardware and software. The hardware consists of field monitoring instruments, field control equipment, signal isolation and conversion system, power supply system, and computer system. The software consists of display interface, kiln body 3D model, and control program.

[0050] System hardware and software function configuration:

[0051] 1) System hardware configuration and functions

[0052] (1) On-site monitoring equipment

[0053] As attached Figure 1 As shown, the following equipment is set up in the gas ignition area:

[0054] Equipment Symbol Equipment Name Equipment Purpose Equipment Specification AE / AT-1 Gas Calorimeter Monitor gas calorific value Range: 0 ~ X kJ / m3 Power supply: 220V AC FE / FT-1 Gas Flowmeter Monitor gas flow Range: 0 ~ X m3 / h Power supply: 220V AC PE / PT-1 Pressure Transmitter Monitor gas pressure Range: 0 ~ 1 MPa Power supply: 24V DC FV / FZ-1 Electric Regulating Valve Regulate gas flow Power supply: 220V AC FE / FT-2 Gas Flowmeter Monitor air flow Range: 0 ~ X m3 / h Power supply: 220V AC PE / PT-2 Pressure Transmitter Monitor air pressure Range: 0 ~ 1 MPa Power supply: 24V DC FV / FZ-2 Electric Regulating Valve Regulate air flow Power supply: 220V AC PE / PT-3 Pressure Transmitter Monitor gas pressure before burner Range: 0 ~ 1 MPa Power supply: 24V DC PV / PZ-3 Quick Cut-off Valve Low pressure gas quick cut-off Power supply: 220V AC BE-1 Flame Detector Monitor ignition state BS-1 Igniter Automatic gas ignition Power supply: 220V AC

[0055] As attached Figure 1 As shown, the following monitoring instruments are set in the kiln body:

[0056]

[0057]

[0058] (2) Signal isolation conversion system configuration and function

[0059] As attached Figure 2 The signal isolation and conversion system shown in Figure 2 includes a signal isolator, a power distributor, corresponding circuit breakers, and a cabinet. The system's primary function is to transmit signals from on-site instruments and control equipment to the computer system, and to transmit control command signals to on-site control equipment for isolation and protection.

[0060] (3) Computer system

[0061] As attached Figure 2 As shown in the computer system, this part includes the PLC system, cabinet, switch, module, host computer, database, etc. The PLC system and module are responsible for collecting signals and issuing instructions, while the host computer is responsible for screen display and intelligent algorithm program processing.

[0062] 2) System software configuration and functions

[0063] (1) Display interface: including display and operation interface programs such as process, parameters, and control panel.

[0064] A complete 3D model of the kiln body is constructed, and a mathematical model is established to simulate the firing process in the kiln, displaying the temperature field inside and outside the kiln in real time and predicting the temperature change trend.

[0065] A mathematical model is established to simulate the data of the gas and air pipeline network, realizing the real-time display of the status of the gas and air pipeline network.

[0066] (2) Intelligent control program: including signal reception, analysis, processing, and distribution programs.

[0067] Build intelligent algorithms to control gas, air, and kiln speed, realize control of important process parameters in the kiln, and ultimately control the roasting flame shape, thereby completing the digital twin simulation of the roasting process and realizing monitoring, prediction, and intelligent control of the roasting status.

[0068] 3. Kiln digital simulation control process and algorithm:

[0069] As attached Figure 3 As shown, the main adjustment mode of this system is: monitoring - intelligent analysis - control - feedback, abnormal alarm. In this invention, the main program flow is as follows:

[0070] Step 1: Construct 3D model of kiln body and gas and air pipes:

[0071] The BIM software is used to build the 3D model of the kiln body and the gas and air pipe network.

[0072] Step 2: Obtain the on-site instrument detection parameters (appendix Figure 1 on-site instrument)

[0073] Store the on-site instrument monitoring parameters in the SQL database.

[0074] Step 3: Data storage, while making a display on the 3D model of the kiln body and the gas and air pipe network

[0075] Display the on-site instrument monitoring parameters in the 3D model.

[0076] Step 4: Fitting of the roasting temperature in the kiln (appendix Figure 3 , Four )

[0077] 4.1 Build the kiln image coordinate system xy, read the kiln tail position (x1, y1) kiln temperature TE4, kiln head position (x2, y2) kiln temperature TE2, and position (x3, y2) kiln temperature TE3;

[0078] 4.2 In the same coordinate system xy, build the kiln skin temperature image according to TE-5ABC imaging;

[0079] 4.3 Kiln temperature solving process:

[0080] The kiln tail kiln internal and external temperature difference is:

[0081] Δt 尾 = TE4-TE 54 (1)

[0082] The kiln head kiln internal and external temperature difference is:

[0083] Δt 头 = (TE2-TE 52 + TE3-TE 53 ) / 2 (2)

[0084] Kiln temperature:

[0085] t 内(x,y) = (Δt 头 - Δt 尾 )*(y-y1) / (y2-y1)+t 外(x,y) (3)

[0086] Solve the kiln temperature t 内(x,y) of each coordinate point in turn to generate the kiln temperature image.

[0087] Wherein, TE54, TE53, TE52 are local temperature points of the kiln skin temperature image.

[0088] Step 5: Construct the kiln body 3D firing twin

[0089] The kiln skin temperature TE-5ABC collected t 外(x,y) , kiln temperature t 内(x,y) The images collected by the kiln head thermal imaging TE-1 are used to construct three-dimensional twins in the software model and displayed on the software screen.

[0090] Step 6: Flame shape fitting

[0091] The flame shape is extracted from the temperature image captured by the kiln head thermal imaging TE-1 and displayed in the 3D model. The flame shape information and the corresponding gas, air, and kiln speed are stored in the graphic database.

[0092] Step 7: Flame Morphology Analysis

[0093] Analyze the flame length and width, and compare it with the high-quality flame shapes in the database to determine the flame shape quality.

[0094] Step 8: Adjust the gas and air volume to stabilize the flame shape

[0095] According to the flame shape quality and the calorific value of the gas measured by the calorific value meter AE / AT-1, the gas control parameters are adjusted to achieve high-quality roasting.

[0096] Step 9: Accident status analysis, alarm, and interlocking

[0097] Low pressure alarms are set for all pressure measurement values, and a low pressure shut-off quick shut-off valve PV / PZ-3 is set for the gas pressure PE / PT-3 before the burner to prevent production accidents.

Claims

1. A control method for a calcination digital twin system of a calcination kiln body, wherein the calcination digital twin system of the calcination kiln body comprises: 1) field monitoring instruments, including various types of field temperature, pressure, flow, and heat value analysis instruments; 2) field control equipment, including various types of field regulating valves, shut-off valves, and frequency conversion equipment; 3) a signal isolation conversion system, including an isolator, a circuit breaker, and a cabinet thereof; 4) a computer system, including a PLC system, a cabinet, a switch, a module, and a database; wherein the signals of the field monitoring instruments and the field control equipment are sent to the computer system through the signal isolation conversion system, and the instruction signals of the computer system are sent to the field control equipment through the signal isolation conversion system; characterized in that it comprises the following steps: Step 1: constructing a 3D model of the kiln body and the gas-air pipe network constructing a 3D model of the kiln body and the gas-air pipe network according to the specific structure of the kiln body; Step 2: obtaining data of the field detection instruments Step 3: data storage, while making a display on the 3D model of the kiln body and the gas-air pipe network storing the data of the field detection instruments in the SQL database of the computer system, and displaying the data of the field detection instruments in the 3D model; Step 4: fitting the calcination temperature in the kiln 4.1 constructing a kiln image coordinate system xy, reading the kiln tail position (x1, y1) kiln temperature TE4, the kiln head position (x2, y2) kiln temperature TE2, and the position (x3, y2) kiln temperature TE3; 4.2 constructing a kiln skin temperature image according to the kiln skin infrared temperature measurement instrument imaging in the same coordinate system xy; 4.3 solving process of kiln temperature: the kiln tail kiln internal and external temperature difference is: Δt 尾 = TE4 - TE 54 (1) the kiln head kiln internal and external temperature difference is: Δt 头 = (TE2- TE 52 + TE3- TE 53 ) / 2 (2) the kiln temperature is: t 内（x,y） = (At 头 - At 尾 ) * (y - y1) / (y2 - y1) + t 外（x,y） (3) Solving the temperature t of each coordinate point in the kiln in turn 内（x,y） Generating a temperature image in the kiln; wherein TE54, TE53, and TE52 are local temperature points of the kiln skin temperature image; Step 5: constructing a 3D calcination twin body of the kiln body The temperature t of the kiln skin collected by the infrared temperature measuring instrument 外（x,y） , the temperature t in the kiln 内（x,y） , and the image collected by the colorimetric temperature measuring instrument at the kiln head are respectively constructed into three-dimensional twins in the kiln body 3D model and displayed. Step 6: fitting the flame shape extracting the flame shape from the temperature image collected by the kiln head colorimetric temperature instrument, displaying it in the 3D model, and storing the flame shape information and corresponding coal gas, air, and kiln body rotating speed data into the graphic database; Step 7: flame shape analysis analyzing the length and width of the flame, and comparing with the high-quality flame shape in the graphic database to determine the quality of the flame shape; Step 8: adjusting the amount of coal gas and air to stabilize the flame shape according to the determined quality of the flame shape, adjusting the coal gas control parameters according to the coal gas calorific value measured by the coal gas calorimeter to achieve high-quality calcination.

2. The control method of the roasting digital twin system of the roasting kiln body according to claim 1, characterized in that, It also comprises Step 9: accident state analysis, alarm, and interlocking setting a low pressure alarm for all pressure measurement values, wherein the low pressure shut-off quick cut-off valve is set for the coal gas pressure transmitter before the burner to prevent production accidents.

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