Intelligent dual-fuel switching control system and method for crude tin smelting furnace

Abstract

The application discloses an intelligent dual-fuel switching control system and method for a crude tin smelting furnace, relates to the technical field of crude tin smelting, and comprises a DCS management layer, a DCS control layer and a field device layer. The intelligent dual-fuel switching system intelligently selects according to actual fuel parameters, selects corresponding configuration parameters according to fuel media, and ensures the temperature of the crude tin smelting furnace. The application solves the problem of single fuel for the crude tin smelting furnace, solves manual intervention from the control aspect, ensures the safety and stability of the crude tin smelting furnace, and provides a more flexible and reliable intelligent control system for the production of the crude tin smelting process.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of crude tin smelting, and more particularly to an intelligent dual-fuel switching control system and method for a crude tin smelting furnace. BACKGROUND

[0002] With the rapid development of crude tin smelting technology, the production scale is expanding, and the process is becoming more and more complex. The requirements for crude tin smelting production cost, technology and intelligent control are becoming higher and higher. In the traditional crude tin smelting process, the fuel used by the smelting furnace is bituminous coal. Using single fuel of coal powder, on the one hand, a large amount of dust is generated in the processing and transportation process of coal powder, increasing the difficulty of environmental protection management; on the other hand, a large amount of CO gas is generated in the combustion process of coal powder, which has a certain impact on environmental protection. In addition, the processing and transportation of coal powder consume a lot of cost, which does not achieve the purpose of energy saving and consumption reduction, and is not conducive to the long-term development of the company. At the same time, the dust after the combustion of bituminous coal brings certain influence and processing difficulty to the smelting furnace. Furthermore, coal is neither a renewable resource nor a clean energy, and it has its limitations in reserves, and cannot be used as a long-term fuel for crude tin smelting.

[0003] Based on the above situation, it is necessary to explore and research dual-fuel intelligent control and optimize the switching scheme, hoping to not only greatly improve the environmental quality, reduce personnel intervention and improve production efficiency, but also realize the bidirectional selection control of fuel.

[0004] Therefore, how to realize the dual-fuel function and control of crude tin smelting, reduce production cost and improve production efficiency is a problem to be solved by those skilled in the art. SUMMARY

[0005] Therefore, the present application provides an intelligent dual-fuel switching control system and method for a crude tin smelting furnace, which solves the problems existing in the traditional single-fuel control system of crude tin smelting, solves the single nature of fuel, and maximizes the saving of company operating costs.

[0006] In order to achieve the above purpose, the present application adopts the following technical scheme:

[0007] An intelligent dual-fuel switching control system for a crude tin smelting furnace, comprising a DCS management layer, a DCS control layer and a field device layer;

[0008] The DCS management layer comprises a DCS engineer station and a DCS configuration server;

[0009] The DCS control layer comprises a DCS controller, a data acquisition module and an output data module; the DCS controller is connected with the data acquisition module and the output data module through an EBUS bus for data interaction; the DCS controller is connected with a DCS configuration server and a DCS engineer station through a switch for communication; the DCS controller is connected with the switch through an LBUS bus for data interaction; the switch is connected with the DCS configuration server and the DCS engineer station through an industrial Ethernet for data interaction;

[0010] The field device layer comprises a fuel one device layer and a fuel two device layer; the data acquisition module is connected with the fuel one device layer and the fuel two device layer for communication, acquires device layer data and transmits the device layer data to the DCS controller; the DCS controller generates control instructions according to a furnace body operation mode and device layer data and transmits the control instructions to the output data module; the output data module is connected with the fuel one device layer and the fuel two device layer for communication and controls the fuel one device layer or the fuel two device layer according to the control instructions.

[0011] The technical effects of the above technical solution are that the data acquisition module acquires device layer data and transmits the device layer data to the DCS controller; the DCS controller is connected with the switch through the LBUS bus; the switch is connected with the DCS engineer station and the DCS configuration server through the industrial Ethernet; the data of the DCS controller is transmitted to the DCS configuration server through the switch and the industrial Ethernet in sequence for data display and real-time monitoring; the DCS engineer station is connected with the DCS controller for communication and burns a control program into the DCS controller.

[0012] Preferably, the fuel one equipment layer comprises an oxygen pressure detector A, an oxygen cut-off valve, an oxygen flow detector A, an oxygen regulating valve A, a natural gas pressure detector, a natural gas cut-off valve, a natural gas flow detector, a natural gas regulating valve, an oxygen purge valve, a natural gas purge valve, a nitrogen pressure detector, a nitrogen cut-off valve, a nitrogen flow detector, a nitrogen regulating valve, a secondary air pressure detector A, a secondary air flow detector A, a secondary air regulating valve A and a lance; the oxygen pressure detector A, the oxygen cut-off valve, the oxygen flow detector A and the oxygen regulating valve A are connected in sequence; the natural gas pressure detector, the natural gas cut-off valve, the natural gas flow detector and the natural gas regulating valve are connected in sequence; the nitrogen pressure detector, the nitrogen cut-off valve, the nitrogen flow detector and the nitrogen regulating valve are connected in sequence; the secondary air pressure detector A, the secondary air flow detector A and the secondary air regulating valve A are connected in sequence; the outlet end of the oxygen regulating valve A is connected to the outlet end of the oxygen purge valve and the lance respectively, the inlet end of the oxygen purge valve is connected to the inlet end of the nitrogen pressure detector and the inlet end of the natural gas purge valve, the outlet end of the natural gas purge valve, the outlet end of the natural gas regulating valve, the outlet end of the nitrogen regulating valve and the outlet end of the secondary air regulating valve A are all connected to the lance; the oxygen pressure detector A, the oxygen flow detector A, the natural gas pressure detector, the natural gas flow detector, the nitrogen pressure detector, the nitrogen flow detector, the secondary air pressure detector A and the secondary air flow detector A are all electrically connected to the data acquisition module; the oxygen cut-off valve, the oxygen regulating valve A, the natural gas cut-off valve, the natural gas regulating valve, the oxygen purge valve, the natural gas purge valve, the nitrogen cut-off valve, the nitrogen regulating valve and the secondary air regulating valve A are all electrically connected to the output data module; the lance is inserted through the opening on the furnace body and installed in the furnace body.

[0013] Preferably, the fuel two equipment layer comprises a primary air pressure detector, a primary air flow detector, a primary air regulating valve, a pulverized coal bin, a pulverized coal feeder, a secondary air pressure detector B, a secondary air flow detector B, a secondary air regulating valve B, an oxygen pressure detector B, an oxygen flow detector B and an oxygen regulating valve B; the primary air pressure detector, the primary air flow detector and the primary air regulating valve are connected in sequence; the secondary air pressure detector B, the secondary air flow detector B and the secondary air regulating valve B are connected in sequence; the oxygen pressure detector B, the oxygen flow detector B and the oxygen regulating valve B are connected in sequence; the outlet end of the primary air regulating valve is connected to the connecting pipeline between the outlet end of the pulverized coal bin and the inlet end of the pulverized coal feeder, the outlet end of the pulverized coal feeder, the outlet end of the secondary air regulating valve B and the outlet end of the oxygen regulating valve B are all connected to the furnace body; the primary air pressure detector, the primary air flow detector, the pulverized coal feeder, the secondary air pressure detector B, the secondary air flow detector B, the oxygen pressure detector B and the oxygen flow detector B are all electrically connected to the data acquisition module; the primary air regulating valve, the pulverized coal feeder, the secondary air regulating valve B and the oxygen regulating valve B are all electrically connected to the output data module.

[0014] Preferably, the fuel one filled in the fuel one equipment layer is natural gas, and the fuel two filled in the fuel two equipment layer is coal powder; the supply condition of the fuel one is determined by the natural gas pressure value detected by the natural gas pressure detector in the fuel one equipment layer, and the DCS controller controls the automatic switching of the fuel according to the supply condition of the fuel one; in the case of sufficient supply of the fuel one, the system preferentially selects the fuel one equipment layer to supply energy by using the fuel one; and in the case of insufficient supply of the fuel one, the system switches to the fuel two equipment layer to supply energy by using the fuel two.

[0015] Preferably, the natural gas pressure value is compared with the set minimum natural gas pressure value; if the natural gas pressure value is greater than or equal to the minimum natural gas pressure value, the supply condition is that the fuel one is supplied sufficiently, and the fuel one equipment layer is switched to work; otherwise, the supply condition is that the fuel one is supplied insufficiently, and the fuel two equipment layer is switched to work.

[0016] Preferably, the furnace operation mode includes a preparation mode, a blowing mode and a furnace slagging mode; in the DCS controller, different preset valve openings of different regulating valves and shut-off valves at the initial time of switching modes are set according to different modes, or the valve openings are controlled; when the furnace operation mode is automatically switched under different equipment layer working modes, the corresponding valves of different equipment layers are switched to the preset valve openings or are opened, so as to prevent the slag from blocking the lance when the fuel is switched to coal.

[0017] Preferably, when the fuel one equipment layer works, the nitrogen regulating valve and the secondary air regulating valve A are preset to have valve openings, so as to prevent the pipeline from being blocked, the nitrogen gas flow and the secondary air gas flow are set to have corresponding fixed values, and the PID controller in the DCS controller adjusts the openings of the corresponding regulating valves according to the fixed values and the equipment layer data.

[0018] When the preparation mode is switched to the blowing mode, the nitrogen regulating valve, the secondary air regulating valve A, the oxygen regulating valve A and the natural gas regulating valve are preset to have valve openings, so as to ensure that the initial combustion parameter ratio is reasonable and sufficient solvent stirring pressure is provided in the furnace; through the algorithm deployed in the DCS controller, the secondary air gas flow and the oxygen gas flow are calculated to have corresponding gas set values according to the equipment layer data, and the nitrogen gas flow and the natural gas flow are set to have corresponding fixed values; and the PID controller adjusts the openings of the corresponding regulating valves according to the fixed values, the equipment layer data and the gas set values.

[0019] In the slagging mode, the nitrogen regulating valve, the secondary air regulating valve A, the oxygen regulating valve A and the natural gas regulating valve are also preset to have valve openings, so as to maintain normal heat supply.

[0020] Preferably, when the fuel two device layer is working, the DSC controller controls the primary air regulating valve, the secondary air regulating valve B and the oxygen regulating valve B to open in the preparation mode, and sets corresponding gas fixed values for the primary air flow and the secondary air flow;

[0021] In the blowing mode and the slagging mode, corresponding gas fixed values are set for the primary air flow, the secondary air flow and the oxygen flow, and the opening degree of the corresponding valve and / or the speed of the coal powder feeder are adjusted according to the preset gas fixed values.

[0022] The device layer data includes natural gas pressure value, natural gas flow value, oxygen pressure value, oxygen flow value, nitrogen pressure value, nitrogen flow value, secondary air pressure value, secondary air flow value, primary air pressure value, primary air flow value and coal powder feeder speed.

[0023] Preferably, when the fuel one device layer is working, the gas set value includes oxygen flow set value, secondary air flow set value and natural gas flow set value; the oxygen flow set value is calculated according to the oxygen-fuel ratio, the excess coefficient, the natural gas flow value and the secondary air flow value; the secondary air flow set value is calculated according to the nitrogen flow value and the mixed gas set value; and the natural gas flow set value is set according to the experience value of the furnace operation mode.

[0024] The calculation formula of the oxygen flow set value SV1 and the secondary air flow set value SV2 is as follows:

[0025] SV1=K1*K*FT1-FT2*0.21

[0026] SV2=SV-FT3

[0027] Wherein, SV1 is the oxygen flow set value; K1 is the oxygen-fuel ratio; K is the excess coefficient; FT1 is the natural gas flow value; FT2 is the secondary air flow value detected by the secondary air flow detector A; SV2 is the secondary air flow set value; SV is the mixed gas set value; and FT3 is the nitrogen flow value.

[0028] Preferably, the oxygen pressure value, the nitrogen pressure value, the secondary air pressure value and the primary air pressure value are checked to determine whether the gas pressure in the furnace body is stable.

[0029] Preferably, the intelligent double-fuel switching control system for the crude tin smelting furnace is further provided with an operator station and an OPC server, both of which are connected to the Ethernet switch, the operator station is used for data monitoring, and the OPC server is used for uploading data to other systems.

[0030] An intelligent double-fuel switching control method for a crude tin smelting furnace, comprising the following steps:

[0031] Step 1: Collect the natural gas pressure value and determine whether the natural gas pressure value is greater than the switching threshold value.

[0032] Step 2: If the value exceeds the switching threshold, start the fuel one equipment layer to supply fuel one and enter the preparation mode in the furnace operation mode, then proceed to step 3; otherwise, start the fuel two equipment layer to supply fuel two and enter the preparation mode in the furnace operation mode, then proceed to step 7.

[0033] Step 3: Open the oxygen purge valve, natural gas purge valve and nitrogen shut-off valve in the fuel equipment layer, and open the nitrogen regulating valve and secondary air regulating valve A to the preset valve opening, and enter the blowing mode in the furnace operation mode;

[0034] Step 4: Collect equipment layer data in the fuel equipment layer and determine whether any of the following data is less than the minimum set value: natural gas flow rate, oxygen flow rate, secondary air flow rate, natural gas pressure, and oxygen pressure. If all of them are greater than the minimum set value, proceed to step 5; otherwise, enter the preparation mode and return to step 3.

[0035] Step 5: Close the oxygen purge valve and natural gas purge valve in the fuel equipment layer, open the oxygen shut-off valve and natural gas shut-off valve, and open the oxygen regulating valve A, natural gas regulating valve, nitrogen regulating valve and secondary air regulating valve A to the preset valve opening. Calculate the gas setpoint based on the equipment layer data, compare the gas setpoint with the equipment layer data, and adjust the opening of the oxygen regulating valve A, natural gas regulating valve, nitrogen regulating valve and secondary air regulating valve A respectively through the PID controller in the DCS controller according to the comparison result and the preset gas fixed value. The opening of the secondary air regulating valve A is used to control the air flow to reach the secondary air flow setpoint.

[0036] Step 6: Determine the slag condition. If the tin content is lower than the set tin value, enter the furnace body operation mode for slag discharge. Once slag discharge is completed, the blowing process ends. Otherwise, continue the blowing mode and return to Step 5.

[0037] Step 7: Open the primary air regulating valve, secondary air regulating valve B and oxygen regulating valve B in the fuel equipment layer, start the pulverized coal feeder, and enter the blowing mode in the furnace operation mode;

[0038] Step 8: Collect equipment layer data in the fuel equipment layer, and determine whether any of the primary air flow rate, oxygen flow rate and secondary air flow rate is less than the minimum set value. If all of them are greater than the minimum set value, proceed to step 9; otherwise, enter the preparation mode and return to step 7.

[0039] Step 9: Perform PID control of the primary air regulating valve, secondary air regulating valve B, and oxygen regulating valve B according to the preset gas fixed value; determine the slag condition. If the tin content is lower than the set tin value, enter the furnace body operation mode for slag discharge. When the slag discharge ends, the blowing ends; otherwise, continue the blowing mode and return to step 8.

[0040] As can be seen from the above technical solution, compared with the prior art, this invention discloses an intelligent dual-fuel switching control system and method for a crude tin smelting furnace. The system determines the supply status of fuel one based on its pressure value. When fuel one is in sufficient supply, it is preferentially selected as the fuel for the crude tin smelting furnace. The furnace operating mode is used to select and control the switching of the shut-off valve and the opening of the regulating valve. When fuel one is insufficient, fuel two is selected as the fuel for the crude tin smelting furnace. Different set parameters are selected for valve control based on the furnace operating status. The entire system realizes intelligent dual-fuel switching control, selecting appropriate configuration parameters according to the fuel medium to ensure the temperature of the crude tin smelting furnace. This solves the problem of traditional single fuel in crude tin smelting furnaces, eliminates manual intervention in control, improves production efficiency, and ensures the safety and stability of the crude tin smelting furnace, providing a more flexible and reliable intelligent control system for crude tin smelting processes. Attached Figure Description

[0041] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0042] Figure 1 A structural diagram of an intelligent dual-fuel switching control system and method for a crude tin smelting furnace provided in this invention;

[0043] Figure 2 A structural diagram of a fuel-equipment device provided for an example of the present invention;

[0044] Figure 3 The structural diagram of the fuel equipment provided by this invention;

[0045] Figure 4 The present invention provides a program logic control diagram for an intelligent dual-fuel switching control method for a crude tin smelting furnace. Detailed Implementation

[0046] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0047] This invention discloses an intelligent dual-fuel switching control system for a crude tin smelting furnace, such as... Figure 1As shown, the system includes a DCS management layer, a DCS control layer, and a field device layer. The DCS management layer includes a DCS engineering station and a DCS configuration server. The DCS management layer writes the production process control program into the controllers of the DCS control layer through the DCS engineering station and the DCS configuration server, and performs real-time monitoring and control of the DCS control layer data. The DCS control layer includes controllers and data acquisition modules. Data exchange between the DCS controllers and data acquisition modules is achieved through an EBUS bus connection. Data from the DCS control layer is transmitted to the DCS system management layer via a switch for data display and real-time monitoring. Data exchange between the DCS controllers and the switch is achieved through an LBUS bus, and data exchange between the switch and the DCS configuration server and DCS engineering station is achieved through an industrial Ethernet network.

[0048] The field equipment layer includes a fuel equipment layer 1 and a fuel equipment layer 2, as follows: Figure 2 , Figure 3 As shown.

[0049] The first fuel equipment layer includes an oxygen pressure detector A1, an oxygen shut-off valve 2, an oxygen flow detector A3, an oxygen regulating valve A4, a natural gas pressure detector 5, a natural gas shut-off valve 6, a natural gas flow detector 8, a natural gas regulating valve 9, an oxygen purging valve 7, a natural gas purging valve 10, a nitrogen pressure detector 11, a nitrogen shut-off valve 12, a nitrogen flow detector 13, a nitrogen regulating valve 14, a secondary air pressure detector A15, a secondary air flow detector A16, a secondary air regulating valve A17, and a spray gun 18; the second fuel equipment layer includes a primary air pressure detector 19, a primary air flow detector 20, a primary air regulating valve 21, a pulverized coal bunker 22, a pulverized coal feeder 26, a secondary air pressure detector B23, a secondary air flow detector B24, a secondary air regulating valve B25, an oxygen pressure detector B27, an oxygen flow detector B28, and an oxygen regulating valve B29; the spray gun 18 is inserted through an opening on the furnace body and installed inside the furnace body.

[0050] Furthermore, the first fuel layer is filled with natural gas, while the second fuel layer is filled with pulverized coal. The supply status of fuel one is determined by the natural gas pressure value collected by the natural gas pressure detector 5 in the first fuel layer. If the supply of fuel one is sufficient, the system prioritizes fuel one; if the supply of fuel one is insufficient, the system automatically switches to fuel two. The natural gas pressure value is compared with the set minimum natural gas pressure value. If the pressure value is greater than or equal to the minimum pressure value, the supply of fuel one is sufficient, and the system switches to the first fuel layer; otherwise, the supply of fuel one is insufficient, and the system switches to the second fuel layer.

[0051] Furthermore, the furnace operation modes include preparation mode, blowing mode, and furnace slag discharge mode. In the DCS controller, different valve openings are preset for different regulating valves and shut-off valves at the initial moment of mode switching for different modes, or the valves are controlled to open. When the furnace operation mode is automatically switched between different equipment layers, the corresponding valves of different equipment layers are switched to the preset valve openings or opened to prevent slag from clogging the spray guns when switching to coal fuel.

[0052] Furthermore, when the fuel equipment layer is operating, switching to the preparation mode, the opening degrees of the nitrogen regulating valve and secondary air regulating valve A are preset to ensure a certain valve opening value and prevent pipeline blockage. Corresponding fixed gas values ​​are set for the nitrogen and secondary air flow rates. The PID controller in the DCS controller adjusts the opening degree of the corresponding regulating valves based on the fixed gas values ​​and equipment layer data. When switching from the preparation mode to the blowing mode, the opening degrees of the nitrogen regulating valve, secondary air regulating valve A, oxygen regulating valve A, and natural gas regulating valve are preset to ensure a reasonable initial combustion parameter ratio and provide sufficient solvent stirring pressure in the furnace. Through the algorithm deployed in the DCS controller, the corresponding gas setpoints for the secondary air and oxygen flow rates are calculated based on the equipment layer data, and corresponding fixed gas values ​​are set for the nitrogen and natural gas flow rates. The PID controller adjusts the opening degree of the corresponding regulating valves based on the fixed gas values, equipment layer data, and gas setpoints. In the slag discharge mode, the opening degrees of the nitrogen regulating valve, secondary air regulating valve A, oxygen regulating valve A, and natural gas regulating valve are also preset to maintain normal heat supply.

[0053] Furthermore, during the operation of the fuel equipment layer, the DSC controller, in preparation mode, controls the opening of the primary air regulating valve, secondary air regulating valve B, and oxygen regulating valve B, setting corresponding fixed gas values ​​for the primary and secondary air flow rates. In blowing mode and slag discharge mode, corresponding fixed gas values ​​are set for the primary air flow rate, secondary air flow rate, and oxygen flow rate, and the opening degree of the corresponding valves and / or the pulverized coal feeder speed are adjusted according to the preset fixed gas values. Equipment layer data includes natural gas pressure, natural gas flow rate, oxygen pressure, oxygen flow rate, nitrogen pressure, nitrogen flow rate, secondary air pressure, secondary air flow rate, primary air pressure, primary air flow rate, and pulverized coal feeder speed.

[0054] Furthermore, when the fuel equipment layer is in operation, the gas setpoints include oxygen flow rate setpoints, secondary air flow rate setpoints, and natural gas flow rate setpoints. The oxygen flow rate setpoint is calculated based on the oxygen-fuel ratio, excess coefficient, natural gas flow rate, and secondary air flow rate. The secondary air flow rate setpoint is calculated based on the nitrogen flow rate and the total nitrogen and air requirements (mixture setpoint). The natural gas flow rate setpoint is empirically set based on the furnace operation mode.

[0055] The formulas for calculating the oxygen flow rate setpoint and the air flow rate setpoint are as follows:

[0056] SV1 = K1 * K * FT1 - FT2 * 0.21

[0057] SV2 = SV - FT3

[0058] Wherein, SV1 is the oxygen flow rate setpoint; K1 is the oxygen-fuel ratio; K is the excess coefficient; FT1 is the natural gas flow rate; FT2 is the secondary air flow rate; SV2 is the secondary air flow rate setpoint; SV is the mixture setpoint; and FT3 is the nitrogen flow rate.

[0059] Furthermore, the oxygen pressure, nitrogen pressure, secondary air pressure, and primary air pressure values ​​are checked to determine whether the gas pressure inside the furnace is stable.

[0060] Furthermore, the system is equipped with operator stations and an OPC server, both connected to a switch via Ethernet. The operator stations are used for data monitoring, and the OPC server is used to upload data to other systems.

[0061] When the first fuel equipment layer is operating, the parameter configuration table for fuel one is shown in Table 1 below. When the second fuel equipment layer is operating, the primary air volume, secondary air volume, and pulverized coal volume parameters are set accordingly based on the furnace operating mode, as shown in Table 2 below.

[0062] Table 1. Parameter Configuration Table for Fuel Type 1

[0063]

[0064] Table 2 Parameter Configuration for Fuel Type II

[0065]

[0066] In the table, SV represents the gas setpoint, MV preset represents the preset valve opening, and minimum value represents the minimum setpoint.

[0067] Example 2

[0068] Based on the above embodiments, in one specific embodiment, the following is adopted: Figure 4 The illustrated process implements intelligent dual-fuel switching control for a crude tin smelting furnace. Based on operational plans and field data collected by the control layer, management selects the appropriate furnace fuel and configures furnace temperature control accordingly. The slag condition is assessed based on actual smelting conditions; when the tin content in the slag is low, a slag discharge mode is activated, and smelting automatically stops upon completion of slag discharge. The process includes the following steps:

[0069] S1: Collect the natural gas pressure value and determine whether the natural gas pressure value is greater than the switching threshold;

[0070] S2: If the value is greater than the switching threshold, start the fuel one equipment layer to supply fuel one and enter the preparation mode in the furnace operation mode, then proceed to S3; otherwise, start the fuel two equipment layer to supply fuel two and enter the preparation mode in the furnace operation mode, then proceed to S7.

[0071] S3: Open the oxygen purge valve, natural gas purge valve and nitrogen shut-off valve in the fuel equipment layer, and open the nitrogen regulating valve and secondary air regulating valve A to the preset valve opening, and enter the blowing mode in the furnace operation mode.

[0072] S4: Collect equipment layer data in the fuel equipment layer, and determine whether any of the following data is less than the minimum set value: natural gas flow rate, oxygen flow rate, secondary air flow rate, natural gas pressure, and oxygen pressure. If all of them are greater than the minimum set value, proceed to S5; otherwise, enter the preparation mode and return to S3.

[0073] S5: Close the oxygen purge valve and natural gas purge valve in the fuel equipment layer, open the oxygen shut-off valve and natural gas shut-off valve, and open oxygen regulating valve A, natural gas regulating valve, nitrogen regulating valve and secondary air regulating valve A to the preset valve opening. Calculate the gas setpoint based on the equipment layer data, compare the gas setpoint with the equipment layer data, and adjust the opening of oxygen regulating valve A, natural gas regulating valve, nitrogen regulating valve and secondary air regulating valve A respectively through the PID controller in the DCS controller according to the comparison result and the preset gas fixed value. The opening of secondary air regulating valve A is used to control the air flow to reach the secondary air flow setpoint.

[0074] S6: Determine the slag condition. If the tin content is lower than the set tin value, enter the furnace body operation mode for slag discharge. Once slag discharge is completed, the blowing process ends. Otherwise, continue the blowing mode and return to S5.

[0075] S7: Open the primary air regulating valve, secondary air regulating valve B and oxygen regulating valve B in the fuel equipment layer, start the pulverized coal feeder, and enter the blowing mode in the furnace operation mode;

[0076] S8: Collect equipment layer data in the fuel equipment layer, and determine whether any of the primary air flow rate, oxygen flow rate and secondary air flow rate is less than the minimum set value. If all of them are greater than the minimum set value, proceed to S9; otherwise, enter the preparation mode and return to S7.

[0077] S9: Perform PID control of the primary air regulating valve, secondary air regulating valve B, and oxygen regulating valve B according to the preset gas fixed value; judge the slag condition. If the tin content is lower than the set tin value, enter the furnace body operation mode for slag discharge. When the slag discharge ends, the blowing ends; otherwise, continue the blowing mode and return to S8.

[0078] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the apparatus disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the description is relatively simple; relevant parts can be referred to the method section.

[0079] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. An intelligent dual-fuel switching control system for a crude tin smelting furnace, characterized in that, This includes the DCS management layer, the DCS control layer, and the field equipment layer; The DCS management layer includes the DCS engineer station and the DCS configuration server. The DCS control layer includes a DCS controller, a data acquisition module, and an output data module; the DCS controller interacts with the data acquisition module and the output data module; the DCS controller communicates with the DCS configuration server and the DCS engineering station through a switch. The field equipment layer includes the Fuel Equipment Layer 1 and the Fuel Equipment Layer 2; The data acquisition module is connected and communicates with the first and second fuel equipment layers to collect data from the equipment layers and transmit it to the DCS controller. The DCS controller generates control commands based on the furnace operating mode and the equipment layer data and transmits them to the output data module. The output data module is connected and communicates with the first and second fuel equipment layers and controls the first or second fuel equipment layer according to the control commands. The fuel equipment layer includes an oxygen pressure detector A, an oxygen shut-off valve, an oxygen flow detector A, an oxygen regulating valve A, a natural gas pressure detector, a natural gas shut-off valve, a natural gas flow detector, a natural gas regulating valve, an oxygen purging valve, a natural gas purging valve, a nitrogen pressure detector, a nitrogen shut-off valve, a nitrogen flow detector, a nitrogen regulating valve, a secondary air pressure detector A, a secondary air flow detector A, a secondary air regulating valve A, and a spray gun; Oxygen pressure detector A, oxygen shut-off valve, oxygen flow detector A, and oxygen regulating valve A are connected in sequence; natural gas pressure detector, natural gas shut-off valve, natural gas flow detector, and natural gas regulating valve are connected in sequence; nitrogen pressure detector, nitrogen shut-off valve, nitrogen flow detector, and nitrogen regulating valve are connected in sequence; secondary air pressure detector A, secondary air flow detector A, and secondary air regulating valve A are connected in sequence; the outlet end of oxygen regulating valve A is connected to the outlet end of oxygen purging valve and the spray gun respectively; the inlet end of oxygen purging valve is connected to the inlet end of nitrogen pressure detector and the inlet end of natural gas purging valve; the outlet ends of natural gas purging valve, natural gas regulating valve, nitrogen regulating valve, and secondary air regulating valve A are all connected to the spray gun. Oxygen pressure detector A, oxygen flow detector A, natural gas pressure detector, natural gas flow detector, nitrogen pressure detector, nitrogen flow detector, secondary air pressure detector A, and secondary air flow detector A are all electrically connected to the data acquisition module; The oxygen shut-off valve, oxygen regulating valve A, natural gas shut-off valve, natural gas regulating valve, oxygen purging valve, natural gas purging valve, nitrogen shut-off valve, nitrogen regulating valve, and secondary air regulating valve A are all electrically connected to the output data module. The spray gun is inserted through an opening on the furnace body and installed inside the furnace body; The second fuel equipment layer includes a primary air pressure detector, a primary air flow detector, a primary air regulating valve, a pulverized coal silo, a pulverized coal feeder, a secondary air pressure detector B, a secondary air flow detector B, a secondary air regulating valve B, an oxygen pressure detector B, an oxygen flow detector B, and an oxygen regulating valve B. The primary air pressure detector, primary air flow detector, and primary air regulating valve are connected in sequence; the secondary air pressure detector B, secondary air flow detector B, and secondary air regulating valve B are connected in sequence; the oxygen pressure detector B, oxygen flow detector B, and oxygen regulating valve B are connected in sequence; the outlet end of the primary air regulating valve is connected to the connecting pipeline between the outlet end of the pulverized coal bunker and the inlet end of the pulverized coal feeder; the outlet end of the pulverized coal feeder, the outlet end of the secondary air regulating valve B, and the outlet end of the oxygen regulating valve B are all connected to the furnace body; The primary air pressure detector, primary air flow detector, pulverized coal feeder, secondary air pressure detector B, secondary air flow detector B, oxygen pressure detector B, and oxygen flow detector B are all electrically connected to the data acquisition module. The primary air regulating valve, the pulverized coal feeder, the secondary air regulating valve B, and the oxygen regulating valve B are all electrically connected to the output data module. The first fuel layer is filled with natural gas, and the second fuel layer is filled with pulverized coal. The supply status of fuel one is determined by the natural gas pressure value collected by the natural gas pressure detector in the first fuel layer. The DCS controller performs automatic fuel switching control based on the supply status of fuel one. When the supply of fuel one is sufficient, the system prioritizes using the first fuel layer for energy supply. When the supply of fuel one is insufficient, it switches to using the second fuel layer for energy supply.

2. The intelligent dual-fuel switching control system for a crude tin smelting furnace according to claim 1, characterized in that, The furnace operating modes include preparation mode, blowing mode, and furnace slag discharge mode. In the DCS controller, different valve openings are preset for different regulating valves and shut-off valves at the initial moment of switching modes, or the valves are controlled to open. When the furnace operating mode is automatically switched under different equipment layer working modes, the corresponding valves of different equipment layers are switched to the preset valve openings or opened.

3. The intelligent dual-fuel switching control system for a crude tin smelting furnace according to claim 2, characterized in that, When the fuel equipment layer is working, switch to the preparation mode, preset the valve opening of the nitrogen regulating valve and the secondary air regulating valve A, and set the corresponding fixed gas values ​​for the nitrogen flow rate and the secondary air flow rate. The PID controller in the DCS controller adjusts the opening of the corresponding regulating valve according to the fixed gas values ​​and the equipment layer data. When the preparation mode is switched to the blowing mode, the valve openings of the nitrogen regulating valve, secondary air regulating valve A, oxygen regulating valve A and natural gas regulating valve are preset. The algorithm deployed in the DCS controller calculates the corresponding gas setpoints for the secondary air flow and oxygen flow based on the equipment layer data, and sets the corresponding fixed gas values ​​for the nitrogen flow and natural gas flow. The PID controller adjusts the opening of the corresponding regulating valves according to the fixed gas values, equipment layer data and gas setpoints. When switching from the slag discharge mode to the smelting mode, preset the valve openings of the nitrogen regulating valve, secondary air regulating valve A, oxygen regulating valve A, and natural gas regulating valve.

4. The intelligent dual-fuel switching control system for a crude tin smelting furnace according to claim 2, characterized in that, When the fuel equipment layer is working, the DSC controller controls the opening of the primary air regulating valve, secondary air regulating valve B and oxygen regulating valve B in the preparation mode, and sets the corresponding fixed gas values ​​for the primary air flow and secondary air flow. In both blowing and slag discharge modes, corresponding fixed gas values ​​are set for primary air flow, secondary air flow, and oxygen flow. The opening of the corresponding valves and / or the speed of the pulverized coal feeder are adjusted according to the preset fixed gas values.

5. The intelligent dual-fuel switching control system for a crude tin smelting furnace according to claim 3, characterized in that, When the fuel equipment layer is in operation, the gas setpoints include the oxygen flow rate setpoint and the secondary air flow rate setpoint; the oxygen flow rate setpoint is calculated based on the oxygen-fuel ratio, excess coefficient, natural gas flow rate, and secondary air flow rate; the secondary air flow rate setpoint is calculated based on the nitrogen flow rate and the mixed gas setpoint. The formulas for calculating the oxygen flow rate setpoint and the air flow rate setpoint are as follows: SV1 = K1 * K * FT1 - FT2 * 0.21 SV2 = SV - FT3 Wherein, SV1 is the oxygen flow rate setpoint; K1 is the oxygen-fuel ratio; K is the excess coefficient; FT1 is the natural gas flow rate detected by the natural gas flow meter; FT2 is the secondary air flow rate detected by the secondary air flow meter A; SV2 is the secondary air flow rate setpoint; SV is the mixed gas setpoint; and FT3 is the nitrogen flow rate detected by the nitrogen flow meter.

6. A method for intelligent dual-fuel switching control of a crude tin smelting furnace, characterized in that, The intelligent dual-fuel switching control system for a crude tin smelting furnace according to any one of claims 1-5 includes the following steps: Step 1: Collect the natural gas pressure value and determine whether the natural gas pressure value is greater than the switching threshold; Step 2: If the value exceeds the switching threshold, start the fuel one equipment layer to supply fuel one and enter the preparation mode in the furnace operation mode, then proceed to step 3; otherwise, start the fuel two equipment layer to supply fuel two and enter the preparation mode in the furnace operation mode, then proceed to step 7. Step 3: Open the oxygen purge valve, natural gas purge valve and nitrogen shut-off valve in the fuel equipment layer, and open the nitrogen regulating valve and secondary air regulating valve A to the preset valve opening, and enter the blowing mode in the furnace operation mode; Step 4: Collect equipment layer data in the fuel equipment layer and determine whether any of the following data is less than the minimum set value: natural gas flow rate, oxygen flow rate, secondary air flow rate, natural gas pressure, and oxygen pressure. If all of them are greater than the minimum set value, proceed to step 5; otherwise, enter the preparation mode and return to step 3. Step 5: Close the oxygen purge valve and natural gas purge valve in the fuel equipment layer, open the oxygen shut-off valve and natural gas shut-off valve, and open the oxygen regulating valve A, natural gas regulating valve, nitrogen regulating valve and secondary air regulating valve A to the preset valve opening. Calculate the gas setpoint based on the equipment layer data, and adjust the opening of the oxygen regulating valve A, natural gas regulating valve, nitrogen regulating valve and secondary air regulating valve A respectively through the PID controller in the DCS controller according to the gas setpoint, equipment layer data and preset gas fixed value. Step 6: Determine the slag condition. If the tin content is lower than the set tin value, enter the furnace body operation mode for slag discharge. Once slag discharge is completed, the blowing process ends. Otherwise, continue the blowing mode and return to Step 5. Step 7: Open the primary air regulating valve, secondary air regulating valve B and oxygen regulating valve B in the fuel equipment layer, start the pulverized coal feeder, and enter the blowing mode in the furnace operation mode; Step 8: Collect equipment layer data in the fuel equipment layer, and determine whether any of the primary air flow rate, oxygen flow rate and secondary air flow rate is less than the minimum set value. If all of them are greater than the minimum set value, proceed to step 9; otherwise, enter the preparation mode and return to step 7. Step 9: Perform PID control of the primary air regulating valve, secondary air regulating valve B, and oxygen regulating valve B according to the preset gas fixed value; determine the slag condition. If the tin content is lower than the set tin value, enter the furnace body operation mode for slag discharge. When the slag discharge ends, the blowing ends; otherwise, continue the blowing mode and return to step 8.

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