A control method and device for lime kiln denitration ammonia water supply

Abstract

The application discloses a control method and device for lime kiln denitration ammonia water supply, wherein voltage detection signals transmitted by power equipment of I-section ammonia water supply and II-section ammonia water supply are acquired respectively; if the voltage detection signal of any section of power equipment is detected as a fault, the section of ammonia water supply is switched to the standby section of ammonia water supply and water supply equipment; the starting frequency pre-stored according to the fault voltage detection signal is transmitted to the standby frequency converter, and the target valve opening pre-stored according to the fault voltage detection signal is transmitted to the standby valve to control the standby section of ammonia water supply. In this way, the initial control of the standby frequency converter and the standby valve can be performed according to the frequency converter and valve state at the time of failure, so that the ammonia water supply amount on site before the failure shutdown can be quickly and timely achieved, and the ammonia water waste is reduced under the condition of ensuring the emission review standard of nitrogen oxides.

Description

Technical Field

[0001] This invention relates to the field of metallurgical technology, and in particular to a method and apparatus for controlling the supply of ammonia water for denitrification in lime kilns. Background Technology

[0002] The steelmaking lime kiln has five kiln top dust collection facilities, each equipped with a denitrification system to reduce nitrogen oxide emissions. Combined with... Figure 2 As shown, three ammonia supply pumps provide ammonia to five lime kilns. One pump supplies kilns 1, 2, and 5; one pump supplies kilns 3 and 4; and the third pump is a backup. (See attached diagram.) Figure 1 As shown, under normal circumstances, valves 1 and 2 are open, while valves 3 and 4 are closed, with water pump 2 and frequency converter 2 serving as backup equipment. The frequencies of frequency converters 1 and 3 are adjusted to control nitrogen oxide and ammonia escape within standard target values, thus regulating the opening of valves 1 and 2. However, if the I-section transformer or II-section transformer alarms due to undervoltage, or if frequency converter 1 or 3 reports a fault and shuts down, water pump 2 needs to be activated to ensure ammonia supply. The common method is to manually activate the backup equipment first, then automatically adjust it; however, this results in excessive nitrogen oxide emissions. If the denitrification system is used to reduce nitrogen oxide emissions too much to the standard value, it wastes ammonia and gas, significantly increasing steelmaking costs. Some systems use conventional automatic activation of the backup equipment, but this is not timely or fast enough, and the control of frequency converter frequency and valve opening cannot promptly reach the ammonia supply level before the fault shutdown.

[0003] Therefore, the question is how to provide ammonia water quickly and timely while minimizing ammonia waste. Summary of the Invention

[0004] In view of the above problems, the present invention is proposed to provide a control method and device for the supply of ammonia water for denitrification in lime kilns. It can initially control the standby frequency converter and standby valves according to the equipment status at the time of failure, so as to quickly and timely reach the ammonia water supply at the site before the failure shutdown, and reduce ammonia water waste while ensuring the emission verification standards of nitrogen oxides.

[0005] According to a first aspect of the present invention, a method for controlling the supply of ammonia water for denitrification in a lime kiln is provided, comprising:

[0006] The voltage detection signals sent by the power equipment supplied with ammonia water in section I and section II are acquired respectively.

[0007] If a fault is detected in the voltage detection signal of any section of power equipment, the ammonia water supply of that section will be switched to the power equipment and water supply equipment of the backup ammonia water supply section.

[0008] The pre-stored start frequency based on the fault voltage detection signal is sent to the backup frequency converter, and the pre-stored target valve opening based on the fault voltage detection signal is sent to the backup valve to control the ammonia water supply in the backup section; wherein, the backup frequency converter is the power equipment for the ammonia water supply in the backup section, and the backup valve is the water supply equipment for the ammonia water supply in the backup section.

[0009] Optionally, the voltage detection signals sent by the power equipment supplying ammonia in stage I and stage II are acquired respectively, including:

[0010] Obtain the voltage detection signal of the transformer supplying ammonia water in section I and the voltage detection signal of the frequency converter;

[0011] The voltage detection signals of the transformer supplying ammonia water in stage II and the voltage detection signals of the frequency converter are obtained; the power equipment includes the frequency converter and the transformer.

[0012] Optionally, before sending the pre-stored starting frequency based on the fault voltage detection signal to the standby inverter, the method further includes:

[0013] For each section of ammonia water supply, when the inverter bus voltage of the power equipment is lower than 950 volts, the low-voltage operating frequency of the inverter is obtained, and when the voltage detection signal of the power equipment in that section is faulty, the low-voltage operating frequency of the transformer in that section is taken as the first target operating frequency.

[0014] The second target operating frequency is obtained based on the operating frequency of the frequency converter of another power equipment that has not experienced a fault;

[0015] The start-up frequency is determined from the first target operating frequency and the second target operating frequency.

[0016] Optionally, the start-up frequency is determined from the first target operating frequency and the second target operating frequency, including:

[0017] The operating frequency of the first target is compared with the operating frequency of the second target, and the larger value is taken as the start frequency.

[0018] Optionally, before sending the target valve opening pre-stored based on the fault voltage detection signal to the standby valve, the method further includes:

[0019] When a fault is detected in the voltage detection signal of any section of power equipment, the valve opening of the ammonia supply valve of that section is saved as the target valve opening.

[0020] Optionally, control the ammonia supply to the backup section, including:

[0021] The standby frequency converter is activated based on the starting frequency.

[0022] The standby valve is set to 100% opening, and when the ammonia flow rate returns to the pre-fault flow rate, the standby valve is adjusted to the target valve opening.

[0023] Optionally, the method also includes:

[0024] After a preset time, the operating frequency of the standby inverter and the valve opening of the standby valve are adjusted according to the ammonia flow rate, ammonia pressure, ammonia escape, and nitrogen oxide emissions. The preset time is 3 seconds.

[0025] According to a second aspect of the present invention, a control device for the supply of ammonia water for denitrification in a lime kiln is provided, comprising:

[0026] The signal acquisition module is used to acquire the voltage detection signals sent by the power equipment supplied with ammonia water in stage I and the power equipment supplied with ammonia water in stage II, respectively.

[0027] The fault detection module is used to switch the ammonia water supply of any section of power equipment to the backup section of ammonia water supply if a fault is detected in the voltage detection signal of any section of power equipment.

[0028] The control module is used to send the pre-stored start frequency based on the fault voltage detection signal to the standby frequency converter and the pre-stored target valve opening based on the fault voltage detection signal to the standby valve, so as to control the ammonia water supply in the standby section; wherein, the standby frequency converter is the power equipment for the standby ammonia water supply and the standby valve is the water supply equipment for the standby ammonia water supply.

[0029] According to a third aspect of the present invention, an electronic device is provided, comprising: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the aforementioned control method for the supply of ammonia water for denitrification in a lime kiln.

[0030] According to a fourth aspect of the present invention, a computer-readable storage medium is provided having a computer program stored thereon, which, when executed by a processor, implements the aforementioned control method for the supply of ammonia water for denitrification in a lime kiln.

[0031] The above-described one or more technical solutions in the embodiments of this specification have at least the following technical effects:

[0032] This specification provides a control method and apparatus for ammonia water supply in a lime kiln denitrification system. It acquires voltage detection signals from the power equipment for both the first and second stages of ammonia water supply. If a fault is detected in the voltage detection signal of either stage, the ammonia water supply for that stage is switched to the power equipment and water supply equipment for the backup stage. A pre-stored start-up frequency based on the fault voltage detection signal is sent to the backup frequency converter, and a pre-stored target valve opening based on the fault voltage detection signal is sent to the backup valve to control the backup ammonia water supply. In this way, the backup frequency converter and backup valve can be initially controlled based on the status of the frequency converter and valves at the time of the fault, thereby quickly and timely achieving the ammonia water supply level before the fault shutdown, reducing ammonia water waste while ensuring compliance with nitrogen oxide emission standards.

[0033] The above description is merely an overview of the technical solution of the present invention. In order to better understand the technical means of the present invention and to implement it in accordance with the contents of the specification, and in order to make the above and other objects, features and advantages of the present invention more apparent and understandable, specific embodiments of the present invention are described below. Attached Figure Description

[0034] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Furthermore, the same reference figures denote the same parts throughout the drawings.

[0035] In the attached diagram:

[0036] Figure 1 A schematic diagram of an electronic device according to an embodiment of the present invention is shown.

[0037] Figure 2 A schematic diagram of device relationships in an embodiment of the present invention is shown.

[0038] Figure 3 A flowchart of a method for controlling the supply of ammonia water for denitrification in a lime kiln, according to an embodiment of the present invention, is shown.

[0039] Figure 4 A block diagram of a control device for supplying ammonia water for denitrification in a lime kiln is shown in an embodiment of the present invention.

[0040] icon:

[0041] 100 - Electronic equipment; 10 - Control device for supplying ammonia water for denitrification in lime kilns; 11 - Signal acquisition module; 12 - Fault detection module; 13 - Control module; 20 - Memory; 30 - Processor; 40 - Communication unit. Detailed Implementation

[0042] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, 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. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0043] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0044] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0045] In the description of this invention, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0046] The steelmaking lime kiln has five kiln top dust collection facilities, each equipped with a denitrification system to reduce nitrogen oxide emissions. Combined with... Figure 2 As shown, three ammonia supply pumps provide ammonia to five lime kilns. One pump supplies kilns 1, 2, and 5; one pump supplies kilns 3 and 4; and the third pump is a backup. (See attached diagram.) Figure 1As shown, under normal circumstances, valves 1 and 2 are open, while valves 3 and 4 are closed, with water pump 2 and frequency converter 2 serving as backup equipment. The frequencies of frequency converters 1 and 3 are adjusted to control nitrogen oxide and ammonia escape within standard target values, thus regulating the opening of valves 1 and 2. However, if the I-section transformer or II-section transformer alarms due to undervoltage, or if frequency converter 1 or 3 reports a fault and shuts down, water pump 2 needs to be activated to ensure ammonia supply. The common method is to manually activate the backup equipment first, then automatically adjust it; however, this results in excessive nitrogen oxide emissions. If the denitrification system is used to reduce nitrogen oxide emissions too much to the standard value, it wastes ammonia and gas, significantly increasing steelmaking costs. Some systems use conventional automatic activation of the backup equipment, but this is not timely or fast enough, and the control of frequency converter frequency and valve opening cannot promptly reach the ammonia supply level before the fault shutdown.

[0047] Based on the above, this embodiment proposes a control method and device for the supply of ammonia water for denitrification in lime kilns. By detecting the DC bus voltage of the frequency converter and the undervoltage of a certain section of the transformer, and by collecting ammonia water flow rate, valve opening degree, and frequency converter frequency, the ammonia water supply is optimized through analysis and calculation.

[0048] Please see Figure 1 , Figure 1 This is a structural block diagram of an electronic device 100 provided in this embodiment. Figure 1 As shown, the electronic device may include a control device 10 for the supply of ammonia water for denitrification in a lime kiln, a memory 20, a processor 30, and a communication unit 40. The memory 20 stores machine-readable instructions that can be executed by the processor 30. When the electronic device 100 is running, the processor 30 and the memory 20 communicate with each other via a bus. The processor 30 executes the machine-readable instructions and performs the control method for the supply of ammonia water for denitrification in the lime kiln.

[0049] The memory 20, processor 30, and communication unit 40 are electrically connected directly or indirectly to each other to achieve signal transmission or interaction. For example, these components can be electrically connected to each other through one or more communication buses or signal lines. The control device 10 for the supply of ammonia water for denitrification in the lime kiln includes at least one software function module that can be stored in the memory 20 in the form of software or firmware. The processor 30 is used to execute the executable module (e.g., the software function module or computer program included in the control device 10 for the supply of ammonia water for denitrification in the lime kiln) stored in the memory 20.

[0050] The memory 20 may be, but is not limited to, random access memory (RAM), read-only memory (ROM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), etc.

[0051] In some embodiments, processor 30 is used to perform one or more functions described in this embodiment. In some embodiments, processor 30 may include one or more processing cores (e.g., a single-core processor (S) or a multi-core processor (S)). By way of example only, processor 30 may include a central processing unit (CPU), an application-specific integrated circuit (ASIC), an application-specific instruction-set processor (ASICP), a graphics processing unit (GPU), a physical processing unit (PPU), a digital signal processor (DSP), a field-programmable gate array (FPGA), a programmable logic device (PLD), a controller, a microcontroller unit, a reduced instruction set computer (RISC), or a microprocessor, or any combination thereof.

[0052] For ease of explanation, only one processor is described in electronic device 100. However, it should be noted that electronic device 100 in this embodiment may also include multiple processors, and therefore the steps performed by one processor as described in this embodiment may also be performed jointly or individually by multiple processors. For example, if the server's processor performs steps A and B, it should be understood that steps A and B may also be performed jointly by two different processors or individually by one processor. For example, one processor performs step A, and a second processor performs step B, or the first and second processors jointly perform steps A and B.

[0053] In this embodiment, the memory 20 is used to store the program, and the processor 30 is used to execute the program after receiving the execution instruction. The process definition method disclosed in any implementation of this embodiment can be applied to the processor 30, or implemented by the processor 30.

[0054] The communication unit 40 is used to establish a communication connection between the electronic device 100 and other devices via a network, and to send and receive data via the network.

[0055] In some implementations, the network can be any type of wired or wireless network, or a combination thereof. By way of example only, the network may include wired networks, wireless networks, fiber optic networks, telecommunications networks, intranets, the Internet, local area networks (LANs), wide area networks (WANs), wireless local area networks (WLANs), metropolitan area networks (MANs), public switched telephone networks (PSTNs), Bluetooth networks, ZigBee networks, or near field communication (NFC) networks, or any combination thereof.

[0056] In this embodiment, the electronic device 100 may be, but is not limited to, a laptop computer, an ultra-mobile personal computer (UMPC), a netbook, a personal digital assistant (PDA), or other electronic devices. This embodiment does not impose any restrictions on the specific type of electronic device.

[0057] Understandably, Figure 1The structure shown is for illustrative purposes only. The electronic device 100 may also have... Figure 1 Showing more or fewer components, or having with Figure 1 The different configurations shown. Figure 1 The components shown can be implemented using hardware, software, or a combination thereof.

[0058] based on Figure 1 The implementation architecture of this embodiment provides a control method for the supply of ammonia water for denitrification in a lime kiln, which is based on... Figure 1 The electronic device 100 shown performs the following based on Figure 1 The structural diagram of the electronic device 100 shown illustrates in detail the steps of the control method for the supply of ammonia water for denitrification in a lime kiln provided in this embodiment, in conjunction with... Figure 2 , Figure 3 As shown, the method for controlling the supply of ammonia water for denitrification in the lime kiln includes steps 101 to 103:

[0059] Step 101: Obtain the voltage detection signals sent by the power equipment supplied with ammonia water in section I and section II, respectively.

[0060] In this embodiment, the normal ammonia supply consists of two sections: Section I and Section II. If one section fails, it switches to the backup section. The equipment used in Section I and Section II is essentially the same, including electrical equipment and water supply systems. When the electrical equipment is functioning normally, both Section I and Section II supply ammonia to the five lime kilns. If the electrical equipment in one section fails, the backup section takes over, supplying ammonia to the five lime kilns. The voltage detection signal from the electrical equipment indicates whether that section is faulty.

[0061] The main power equipment includes transformers and frequency converters, and the voltage detection signals are obtained from the transformers and frequency converters in each section. Specifically, the voltage detection signals of the transformer supplying ammonia water in section I and the frequency converter are obtained; the voltage detection signals of the transformer supplying ammonia water in section II and the frequency converter are also obtained.

[0062] Step 102: If a voltage detection signal for any segment of power equipment is detected as faulty, then the voltage detection signal for any segment of power equipment is detected as faulty.

[0063] Common faults include low voltage reports from the inverter's DC bus or undervoltage reports from the distribution cabinet circuit breaker. It should be noted that the distribution cabinet is connected to the transformer; if the distribution cabinet circuit breaker reports undervoltage, it indicates that a section of the transformer is undervoltage. A voltage detection signal from any section of electrical equipment indicates a fault.

[0064] Step 103: Send the pre-stored start frequency based on the fault voltage detection signal to the standby frequency converter, and send the pre-stored target valve opening based on the fault voltage detection signal to the standby valve to control the ammonia water supply in the standby section; wherein, the standby frequency converter is the power equipment for the ammonia water supply in the standby section, and the standby valve is the water supply equipment for the ammonia water supply in the standby section.

[0065] The starting frequency is predetermined. For each ammonia supply segment, before the inverter's DC bus reports a low voltage, there is a voltage reduction process. During this process, when the inverter bus voltage drops below 950 volts, the low-voltage operating frequency of that inverter is obtained. When the voltage detection signal of that segment's power equipment indicates a fault, the low-voltage operating frequency of that transformer is used as the first target operating frequency. Then, based on the inverter operating frequency of another segment of power equipment that is not experiencing a fault, a second target operating frequency is obtained. For example, in the event of a fault, the inverter operating frequency of the other segment is multiplied by two-thirds to obtain the second target operating frequency. The starting frequency is determined from the first and second target operating frequencies. Specifically, the first and second target operating frequencies can be compared, and the larger value is taken as the starting frequency.

[0066] In this embodiment, before sending the target valve opening pre-stored based on the fault voltage detection signal to the standby valve, the method further includes:

[0067] When a voltage detection signal for any segment of power equipment is detected as faulty, the valve opening of the ammonia supply valve for that segment is saved as the target valve opening. This target valve opening is then sent to the standby valve to control the ammonia supply to the standby segment. When controlling the ammonia supply, the standby frequency converter starts according to its startup frequency; the standby valve opening is initially 100%, and once the ammonia flow rate returns to its pre-fault level, the standby valve is adjusted to the target valve opening. After a preset time (3 seconds), the operating frequency of the standby frequency converter and the valve opening of the standby valve are adjusted based on the ammonia flow rate, ammonia pressure, ammonia escape, and nitrogen oxide emissions.

[0068] To facilitate understanding and implementation by those skilled in the art, combined with Figure 2 As shown, the example of a shutdown due to undervoltage in section II and undervoltage in inverter No. 3 is used to illustrate the problem.

[0069] Figure 2 The main components include circuit breakers in section I and section II distribution cabinets, contactor 1, contactor 2, frequency converters 1-3, ammonia water supply pumps 1-3, valves 1-4, ammonia water flow detection devices for kilns 1-5, PLC, and WinCC host computer.

[0070] Section I distribution cabinet circuit breaker: connected to Section I transformer, equipped with an undervoltage detection device, which transmits digital signals to the PLC. When it goes high, it triggers an undervoltage alarm.

[0071] Section II distribution cabinet circuit breaker: connected to Section II transformer, equipped with an undervoltage detection device, which transmits digital signals to the PLC. When it goes high, it triggers an undervoltage alarm.

[0072] Contactor 1: Connected to the circuit breaker of section I distribution cabinet and frequency converter No. 2, and connected to PLC. The PLC transmits the activation and deactivation signals to contactor 1.

[0073] Contactor 2: Connected to the circuit breaker of Section II distribution cabinet and frequency converter No. 2, and connected to PLC. The PLC transmits the activation and deactivation signals to contactor 2.

[0074] Frequency converters 1-3: control the motors of water supply pumps 1-3 respectively, and play a role in speed regulation.

[0075] Ammonia supply pumps 1-3: Pump 1 supplies ammonia to kilns 1, 2, and 5; pump 3 supplies ammonia to kilns 3 and 4; pump 2 is used as a backup pump and is started when there is a problem with the ammonia supply system 1 or 3.

[0076] Valve 1-4: Under normal circumstances, valves 1 and 2 are in the open state, transmitting open / close digital signals to the PLC; when using water pump No. 2 and there is a problem with the water supply circuit of valve 1, valve 3 operates, transmitting open / close digital signals to the PLC; when using water pump No. 2 and there is a problem with the water supply circuit of valve 2, valve 4 operates, transmitting open / close digital signals to the PLC.

[0077] Ammonia water flow detection device for kilns 1-5: detects the ammonia water flow rate of kilns 1-5 and transmits the data to the PLC.

[0078] PLC: Receives the aforementioned digital and analog signals, sends start / stop and speed commands to frequency converters 1-3; controls the start / stop of valves 1-4; and transmits alarm information to the WinCC host computer.

[0079] WinCC host computer: Communicates with the PLC and sends commands to the PLC.

[0080] Under normal circumstances, the WinCC host computer sends a pump start command to the PLC, which then sends a command to frequency converters 1 and 3. The ammonia supply pumps 1 and 3 start and are then properly interlocked based on the ammonia flow rate, pressure, ammonia slip value, and nitrogen oxide value to ensure that the nitrogen oxide value and ammonia slip value are below the emission standard.

[0081] During normal ammonia water supply for denitrification, when the DC bus voltage of inverter No. 3 is lower than 950V, the PLC stores the operating frequency of inverter No. 3 in memory M1000. When inverter No. 3 reports a low voltage fault and shuts down, or when the circuit breaker of the II-stage distribution cabinet is undervoltage, the ammonia water flow rate of kiln No. 4 is stored in memory M4 of the PLC, the ammonia water flow rate of kiln No. 5 is stored in memory M5 of the PLC, the valve opening degree of valve 2 is stored in memory M100, and the frequency of inverter No. 1 is multiplied by 2 / 3 and stored in memory M5. In memory M2000, memory M3000 retrieves the maximum value between M1000 and M2000, which serves as the set frequency for starting inverter #2. The PLC controls contactor 1 to energize, valve 2 closes, and valve 4 opens to 100%. When the ammonia flow rate reaches the value in M4 or M5 again, the PLC sets the valve 4 opening to the value in M100. After a 3-second delay, normal adjustment resumes. In other words, the frequency of inverter #2 and the valve 4 opening automatically adjust according to flow rate, pressure, ammonia escape, and nitrogen oxide emissions. This continues until the WinCC host computer determines that the equipment has returned to normal, selects to resume inverter #3 operation, inverter #2 stops working, valve 2 is open, and valve 4 is closed, returning to the initial normal state.

[0082] This implementation method can pre-start the No. 2 ammonia supply pump before the No. 3 frequency converter reports a low voltage fault or before the II-stage transformer experiences undervoltage, and automatically and quickly set a reasonable starting frequency and valve opening. It can also automatically and quickly set a reasonable starting frequency and valve opening when the No. 3 frequency converter reports a fault. This ensures that ammonia escape and nitrogen oxide levels are below the required standard values, meeting environmental protection requirements.

[0083] This specification provides a method for controlling the ammonia water supply in a lime kiln denitrification process. The method involves acquiring voltage detection signals from the power equipment for both the first and second stages of ammonia water supply. If a fault is detected in the voltage detection signal of either stage, the ammonia water supply for that stage is switched to the backup stage's power equipment and water supply equipment. A pre-stored start-up frequency based on the fault voltage detection signal is sent to the backup frequency converter, and a pre-stored target valve opening based on the fault voltage detection signal is sent to the backup valve to control the backup ammonia water supply. This allows for initial control of the backup frequency converter and backup valves based on the status of the frequency converter and valves at the time of the fault, enabling rapid and timely restoration of the ammonia water supply to the pre-fault shutdown level. This reduces ammonia water waste while ensuring compliance with nitrogen oxide emission standards.

[0084] Based on the same inventive concept, combined with Figure 4 As shown, this embodiment of the invention also provides a control device 10 for the supply of ammonia water for denitrification in a lime kiln, including a signal acquisition module 11, a fault detection module 12, and a control module 13.

[0085] The signal acquisition module 11 is used to acquire the voltage detection signals sent by the power equipment supplied with ammonia water in section I and the power equipment supplied with ammonia water in section II, respectively.

[0086] The fault detection module 12 is used to switch the ammonia water supply of any section of power equipment to the backup section of power equipment and water supply equipment if the voltage detection signal of any section of power equipment is detected to be faulty.

[0087] The control module 13 is used to send the pre-stored start frequency based on the fault voltage detection signal to the standby frequency converter and to send the pre-stored target valve opening based on the fault voltage detection signal to the standby valve, so as to control the ammonia water supply in the standby section; wherein, the standby frequency converter is the power equipment for the ammonia water supply in the standby section and the standby valve is the water supply equipment for the ammonia water supply in the standby section.

[0088] In an optional implementation, the signal acquisition module 11 is further configured to:

[0089] Obtain the voltage detection signal of the transformer supplying ammonia water in section I and the voltage detection signal of the frequency converter;

[0090] The voltage detection signals of the transformer supplying ammonia water in stage II and the voltage detection signals of the frequency converter are obtained; the power equipment includes the frequency converter and the transformer.

[0091] In an optional implementation, the control module 13 is further configured to:

[0092] For each section of ammonia water supply, when the inverter bus voltage of the power equipment is lower than 950 volts, the low-voltage operating frequency of the inverter is obtained, and when the voltage detection signal of the power equipment in that section is faulty, the low-voltage operating frequency of the transformer in that section is taken as the first target operating frequency.

[0093] The second target operating frequency is obtained based on the operating frequency of the frequency converter of another power equipment that has not experienced a fault;

[0094] The start-up frequency is determined from the first target operating frequency and the second target operating frequency.

[0095] In an optional implementation, the control module 13 is further configured to:

[0096] The operating frequency of the first target is compared with the operating frequency of the second target, and the larger value is taken as the start frequency.

[0097] In an optional implementation, the control module 13 is further configured to:

[0098] When a fault is detected in the voltage detection signal of any section of power equipment, the valve opening of the ammonia supply valve of that section is saved as the target valve opening.

[0099] In an optional implementation, the control module 13 is further configured to:

[0100] The standby frequency converter is activated based on the starting frequency.

[0101] The standby valve is set to 100% opening, and when the ammonia flow rate returns to the pre-fault flow rate, the standby valve is adjusted to the target valve opening.

[0102] In an optional implementation, the control module 13 is further configured to:

[0103] After a preset time, the operating frequency of the standby frequency converter and the valve opening of the standby valve are adjusted according to the ammonia flow rate, ammonia pressure, ammonia escape, and nitrogen oxide emissions.

[0104] This specification provides a control device for the ammonia water supply in a lime kiln denitrification process. It acquires voltage detection signals from the power equipment in section I and section II of the ammonia water supply system. If a fault is detected in the voltage detection signal of either section, the ammonia water supply for that section is switched to the power equipment and water supply equipment in the backup section. A pre-stored start-up frequency based on the fault voltage detection signal is sent to the backup frequency converter, and a pre-stored target valve opening based on the fault voltage detection signal is sent to the backup valve to control the backup section's ammonia water supply. In this way, the backup frequency converter and backup valve can be initially controlled based on the status of the frequency converter and valves at the time of the fault, thereby quickly and timely reaching the ammonia water supply level before the fault shutdown, reducing ammonia water waste while ensuring compliance with nitrogen oxide emission standards.

[0105] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working process of the control device for the denitrification ammonia water supply in the lime kiln described above can be referred to the corresponding process in the aforementioned method, and will not be elaborated further here.

[0106] Based on the above, this embodiment provides a readable storage medium storing a computer program, which, when executed by a processor, implements the control method for the supply of denitrification ammonia water in a lime kiln according to any of the aforementioned embodiments.

[0107] Those skilled in the art will understand that, for the sake of convenience and brevity, the specific working process of the readable storage medium described above can be referred to the corresponding process in the aforementioned method, and will not be elaborated further here.

[0108] The above are merely various embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A method for controlling the supply of ammonia water for denitrification in a lime kiln, characterized in that, include: The voltage detection signals sent by the power equipment supplied with ammonia water in section I and section II are acquired respectively. If a fault is detected in the voltage detection signal of any section of power equipment, the ammonia water supply of that section will be switched to the power equipment and water supply equipment of the backup ammonia water supply section. The pre-stored start frequency based on the fault voltage detection signal is sent to the backup frequency converter, and the pre-stored target valve opening based on the fault voltage detection signal is sent to the backup valve to control the ammonia water supply in the backup section; wherein, the backup frequency converter is the power equipment for the ammonia water supply in the backup section, and the backup valve is the water supply equipment for the ammonia water supply in the backup section. The method further includes, before sending the pre-stored start-up frequency based on the fault voltage detection signal to the standby frequency converter: For each section of ammonia water supply, when the inverter bus voltage of the power equipment is lower than 950 volts, the low-voltage operating frequency of the inverter is obtained, and when the voltage detection signal of the power equipment in that section is faulty, the low-voltage operating frequency of the transformer in that section is taken as the first target operating frequency. The second target operating frequency is obtained based on the operating frequency of the frequency converter of another power equipment that has not experienced a fault; The first target operating frequency is compared with the second target operating frequency, and the larger value is taken as the start frequency.

2. The method for controlling the supply of ammonia water for denitrification in a lime kiln according to claim 1, characterized in that, The acquisition of voltage detection signals from the power equipment supplying ammonia in section I and section II includes: Obtain the voltage detection signal of the transformer supplying ammonia water in section I and the voltage detection signal of the frequency converter; The voltage detection signal of the transformer supplying ammonia water in stage II and the voltage detection signal of the frequency converter are obtained; wherein, the power equipment includes the frequency converter and the transformer.

3. The method for controlling the supply of ammonia water for denitrification in a lime kiln according to claim 1, characterized in that, Before sending the target valve opening pre-stored based on the fault voltage detection signal to the standby valve, the method further includes: When a fault is detected in the voltage detection signal of any section of power equipment, the valve opening of the ammonia supply valve of that section is saved as the target valve opening.

4. The method for controlling the supply of ammonia water for denitrification in a lime kiln according to claim 1, characterized in that, The control of the backup ammonia supply includes: The backup frequency converter is activated according to the starting frequency; The backup valve is set to 100% opening, and when the ammonia flow rate recovers to the pre-fault flow rate, the backup valve is adjusted to the target valve opening.

5. The method for controlling the supply of ammonia water for denitrification in a lime kiln according to claim 4, characterized in that, The method further includes: After a preset time, the operating frequency of the backup frequency converter and the valve opening of the backup valve are adjusted according to the ammonia flow rate, ammonia pressure, ammonia escape, and nitrogen oxide emissions; wherein, the preset time is 3 seconds.

6. A control device for supplying ammonia water for denitrification in a lime kiln, characterized in that, include: The signal acquisition module is used to acquire the voltage detection signals sent by the power equipment supplied with ammonia water in stage I and the power equipment supplied with ammonia water in stage II, respectively. The fault detection module is used to switch the ammonia water supply of any section of power equipment to the backup section of ammonia water supply if a fault is detected in the voltage detection signal of any section of power equipment. The control module is used to send the pre-stored start frequency based on the fault voltage detection signal to the backup frequency converter, and to send the pre-stored target valve opening based on the fault voltage detection signal to the backup valve, so as to control the ammonia water supply in the backup section; wherein, the backup frequency converter is the power equipment for the ammonia water supply in the backup section, and the backup valve is the water supply equipment for the ammonia water supply in the backup section. The control module is further configured to, before sending the pre-stored start-up frequency based on the fault voltage detection signal to the backup frequency converter, include: for each section of ammonia supply, when the frequency converter bus voltage of the power equipment is below 950 volts, acquiring the low-voltage operating frequency of the frequency converter, and when the voltage detection signal of the power equipment section is a fault, using the low-voltage operating frequency of the transformer of that section as the first target operating frequency; obtaining a second target operating frequency based on the frequency converter operating frequency of another power equipment section that has not experienced a fault; comparing the first target operating frequency with the second target operating frequency, and using the larger value as the start-up frequency.

7. An electronic device, characterized in that, The electronic device includes: a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it implements the control method for supplying ammonia water for denitrification in lime kilns as described in any one of claims 1-5.

8. A computer-readable storage medium, characterized in that, It stores a computer program that, when executed by a processor, implements the control method for the supply of ammonia water for denitrification in lime kilns as described in any one of claims 1-5.

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