Lime kiln intelligent combustion control system and method

Abstract

The invention relates to the technical field of lime kiln combustion control, in particular to a lime kiln intelligent combustion control system and method.The system comprises an acquisition control unit, an optimization control unit and a data acquisition unit, and the acquisition control unit comprises a PLC and a first-stage control system composed of a remote IO station in communication connection with the PLC; the optimization control unit comprises a secondary control system in communication connection with the primary control system, the secondary control system is provided with a plurality of prediction models used for predicting furnace conditions and calculating control strategies, optimization calculation is carried out based on data collected by the primary control system, and a control instruction issued by the primary control system is forwarded. According to the method, a first-level automatic system is guided by constructing a multi-type production system model, the production process is optimized, unnecessary fuel consumption is reduced through a model algorithm, energy loss caused by manual operation is reduced, the combustion temperature is accurately controlled, and the production quality is guaranteed.

Description

Technical Field

[0001] The present invention relates to the technical field of lime kiln combustion control, and in particular to a lime kiln intelligent combustion control system and method. Background Art

[0002] The double-chamber kiln is the first type of lime kiln currently in use. It uses two kiln chambers for alternating calcination. The lime produced has high activity and good quality, and can meet the lime needs of most users in the market. In the production process of the double-chamber kiln, the current level of automatic control of the lime kiln is low. The fluctuation of the limestone raw material composition and the lag in the quality detection of the finished lime product have caused great restrictions on the production process. For this reason, this application proposes a lime kiln intelligent combustion control system and method. Summary of the invention

[0003] In view of the above technical problems, the present invention overcomes the shortcomings of the prior art and provides a lime kiln intelligent combustion control system and method. The system guides the primary automation system by constructing various production system models, optimizes the production process, reduces unnecessary fuel consumption through model algorithms, reduces energy loss caused by manual operation, accurately controls the combustion temperature, and ensures production quality.

[0004] In a first aspect, the present invention provides a lime kiln intelligent combustion control system, comprising: The acquisition control unit includes a primary control system for acquiring and controlling field device data, wherein the primary control system includes a PLC controller and a remote IO station connected to the PLC controller; An optimization control unit includes a secondary control system connected to the primary control system in communication, wherein the secondary control system has a plurality of prediction models for predicting furnace conditions and calculating control strategies; performing optimization calculations based on data collected by the primary control system and forwarding control instructions to the primary control system; And a data acquisition unit is used to collect the PLC data of the primary control system specified by the electricity meter data and upload it to the Internet of Things platform.

[0005] Furthermore, the primary control system is connected with: Converter gas flowmeter for detecting converter gas flow; Pneumatic regulating valve for regulating the flow of coke oven gas; A mixed gas flow meter for detecting the flow rate of mixed gas; Scales for checking the weight of finished products; Oxygen content detector for detecting the oxygen content of combustion air; and Watt-hour meter for checking power consumption of fans and gas compressors.

[0006] Furthermore, the multiple prediction models include: A furnace temperature prediction model based on historical production data and historical furnace temperature data; A raw material process matching model established based on historical data of raw materials and furnace temperature; An ash quality prediction model based on historical raw material batches, ash quality test results and furnace temperature historical data; and A kiln coal burning zone prediction model based on real-time operating parameters.

[0007] Furthermore, the input parameters of the prediction model of the kiln calcining zone include: furnace temperature, ash quality, furnace discharge amount, ignition frequency and combustion-supporting frequency.

[0008] Furthermore, the secondary control system also includes an alarm management unit for real-time processing, monitoring and early warning of equipment failures, kiln pressure differences, calorific value fluctuations and temperature change rates.

[0009] In a second aspect, the present invention further provides a control method for the lime kiln intelligent combustion control system according to any solution of the first aspect, specifically comprising the following steps: The primary control system collects the operating data of the on-site equipment in real time, transmits the operating data to the hierarchical control system, uses the multiple prediction models to predict and analyze the lime kiln conditions, calculates the optimal control parameters based on the prediction and analysis results, and sends the control parameters to the hierarchical control system for execution of control.

[0010] The beneficial effects of the present invention are: (1) The present invention meets the requirements of the first-level automatic control system through hardware modification and the addition of new equipment and instruments; guides the first-level automation system by building a variety of production system models and optimizes the production process; reduces unnecessary fuel consumption and energy loss caused by manual operation through model algorithms, accurately controls the combustion temperature, and ensures production quality; (2) After the system provided by the present invention is put into use, excluding abnormal extreme conditions such as equipment failure and low calorific value, the overall automatic operation rate of the system reaches ≥95%, and at the same time, it can achieve disturbance-free switching with the manual control mode, reducing the labor intensity of the furnace burners. DETAILED DESCRIPTION

[0011] The lime kiln combustion control system architecture of this embodiment is divided into two parts: the primary control system and the secondary control system. The primary control system uses Siemens 400 PLC as the control core, connects the modified and newly added equipment data to the PLC, and realizes information interaction and operation control with valves, instrumentation equipment, etc. on the on-site gas pipeline through the host computer HMI screen. At the same time, new collection equipment is added to collect data from the electricity meter to provide data support for the lime kiln combustion optimization secondary control system. The primary PLC data is collected and uploaded to the board IoT simultaneously. A new server is deployed to deploy the lime kiln combustion optimization secondary control system. Through big data analysis, the corresponding prediction model is constructed to realize the calculation and issuance of the optimal control instructions, interact with the primary control system, and reserve interfaces for docking with other systems.

[0012] 1. Basic hardware transformation: installation of converter gas flow meter, coke oven gas regulating valve, mixed gas flow meter, belt scale, watt-hour meter, oxygen content detector and PLC slave station, etc.

[0013] 2. First-level control system transformation: The on-site L1 control system PLC is Siemens S7-400 series, and the CPU uses 416-2. Considering the independence of the original PLC points and the system, an ET200M remote IO station is added to access the signals of the installed converter gas flowmeter, belt scale, oxygen content detector and other equipment.

[0014] 3. Data collection: Deploy data collection stations in the 1# coal pressure PLC distribution room and the electrical room on the second floor of the 3# and 4# kilns, and connect the electricity meter data to the collection gateway via communication; connect the signals of the installed and modified converter gas flowmeter, coke oven gas regulating valve, mixed gas flowmeter, oxygen content detector, belt scale and other equipment to the PLC via 4~20mA signals to provide data support for the lime kiln combustion optimization secondary system, and upload the PLC data to the plate IoT simultaneously.

[0015] 4. Secondary control system transformation: The secondary control system needs to collect data such as lime kiln gas flow, furnace zone temperature, furnace pressure, gas calorific value, loading weight, ash discharge frequency, ash discharge times, and material discharge volume. The above data will jointly participate in combustion control to achieve closed-loop control.

[0016] 5. Algorithm model: The secondary control system for lime kiln combustion optimization uses a set of multiple lime kiln process models to predict a furnace condition model that conforms to the actual situation. The model set includes calculation and prediction, and realizes the prediction results of lime kiln furnace condition prediction, ash quality prediction model and furnace mechanism model based on the underlying data. The model is used to calculate the strategy of gas, combustion air and cooling air supply to achieve the effect of stabilizing the furnace condition and saving gas.

[0017] 6. Alarm management function: The lime kiln combustion optimization system needs to communicate data with other systems such as the automation control system. Therefore, in order to ensure normal communication, a new alarm function for communication interruption between the combustion optimization system and other systems is added. After the communication interruption alarm occurs, the operation and maintenance personnel need to handle it in time. The system provides automatic mode and manual mode. When the alarm is triggered, the operator switches to manual mode in time. When the alarm is triggered, the system automatically identifies the alarm source and alarms at the first time, and handles it quickly. Alarm management includes the management of alarm signals such as equipment failure warning, kiln pressure difference abnormal warning, calorific value fluctuation abnormal warning, ash temperature, channel temperature, and exhaust gas temperature change rate abnormal warning.

[0018] It should be noted that the specific implementation method of the lime kiln combustion control system should be adjusted and optimized according to the on-site process conditions. During the implementation process, sufficient testing and verification are required to ensure the stability and reliability of the system.

[0019] In addition to the above embodiments, the present invention may also have other implementation modes. Any technical solution formed by equivalent replacement or equivalent transformation falls within the protection scope required by the present invention.

Claims

1. A lime kiln intelligent combustion control system, characterized in that: include: The acquisition control unit includes a primary control system for acquiring and controlling field device data, wherein the primary control system includes a PLC controller and a remote IO station connected to the PLC controller; An optimization control unit includes a secondary control system connected to the primary control system in communication, wherein the secondary control system has a plurality of prediction models for predicting furnace conditions and calculating control strategies; performing optimization calculations based on data collected by the primary control system and forwarding control instructions to the primary control system; And a data acquisition unit is used to collect the PLC data of the primary control system specified by the electricity meter data and upload it to the Internet of Things platform.

2. The intelligent combustion control system of lime kiln according to claim 1 is characterized in that: The primary control system is connected with: Converter gas flowmeter for detecting converter gas flow; Pneumatic regulating valve for regulating the flow of coke oven gas; A mixed gas flow meter for detecting the flow rate of mixed gas; Scales for checking the weight of finished products; Oxygen content detector for detecting the oxygen content of combustion-supporting air; as well as Watt-hour meter for checking power consumption of fans and gas compressors.

3. The intelligent combustion control system of lime kiln according to claim 1 is characterized in that: The multiple prediction models include: A furnace temperature prediction model based on historical production data and historical furnace temperature data; A raw material process matching model established based on historical data of raw materials and furnace temperature; An ash quality prediction model based on historical raw material batches, ash quality test results and furnace temperature historical data; and A kiln coal burning zone prediction model based on real-time operating parameters.

4. The intelligent combustion control system of the lime kiln according to claim 3 is characterized in that: The input parameters of the prediction model for the kiln calcining zone include: furnace temperature, ash quality, furnace discharge amount, ignition frequency and combustion-supporting frequency.

5. The intelligent combustion control system of lime kiln according to claim 1 is characterized in that: The secondary control system also includes an alarm management unit for real-time processing, monitoring and early warning of equipment failures, kiln pressure differences, calorific value fluctuations and temperature change rates.

6. The control method of the lime kiln intelligent combustion control system according to any one of claims 1 to 5, characterized in that: The following steps are involved: The primary control system collects the operating data of the on-site equipment in real time, transmits the operating data to the hierarchical control system, uses the multiple prediction models to predict and analyze the lime kiln conditions, calculates the optimal control parameters based on the prediction and analysis results, and sends the control parameters to the hierarchical control system for execution of control.