High-temperature oxygen plasma removal device for high-temperature corrosion control of water-cooled walls to remove CO and H2S

Abstract

This invention discloses a high-temperature oxygen plasma device for removing CO and H2S from water-cooled walls to combat high-temperature corrosion. It includes multiple flue gas reducing atmosphere measuring points located at corresponding positions on the upper water-cooled wall of the furnace. At each measuring point, a corresponding sampling port is provided on the furnace. These ports are connected to a flue gas analyzer via pipes. The inner tube of a short sootblower inside the furnace is connected to a non-transferred arc DC arc oxygen plasma generator via a plasma pipe. The non-transferred arc DC arc oxygen plasma generator and the flue gas analyzer are connected to a control module via wires. This invention uses a short sootblower to spray plasma containing active oxygen free radicals into the upper water-cooled wall region of the furnace, which is prone to high-temperature corrosion. Inside the furnace, the oxygen-containing plasma undergoes a non-equilibrium gas-phase oxidation reaction with the reducing gases CO and H2S, achieving efficient and timely removal of CO and H2S.

Description

Technical Field

[0001] This invention belongs to the technical field of high-temperature corrosion prevention and control devices for coal-fired power plant boilers, and relates to a high-temperature oxygen plasma removal device for high-temperature corrosion treatment of water-cooled walls that removes CO and H2S. This invention also relates to a method for high-temperature corrosion treatment of water-cooled walls that removes CO and H2S using high-temperature oxygen plasma. Background Technology

[0002] In coal-fired power plant boilers, the water-cooled wall tubes in the upper burner layer and the burnout air layer are key areas prone to high-temperature corrosion. Existing technologies primarily mitigate this corrosion by adding wall-mounted air jets in the furnace wall area. Chinese patent "Wall-mounted Air Jet Device for Preventing High-Temperature Corrosion in Pulverized Coal Boilers with Opposing Front and Rear Walls," publication number CN121274229A, publication date 2026.01.06, describes installing wall-mounted air jets on the furnace wall sidewalls to prevent high-temperature corrosion in pulverized coal boilers with opposing front and rear walls. However, the wall-mounted air jet technology requires a certain amount of time for the air to react with reducing gases CO and H2S near the water-cooled wall, resulting in the accumulation of reducing gases such as CO and H2S in the water-cooled area. This method has limitations in preventing high-temperature corrosion. Furthermore, based on engineering experience, current wall-mounted air jet technology still suffers from insufficient airflow volume, inadequate airflow rigidity, and insufficient jet distance. This results in insufficient replenishment of the water-cooled wall near the center of the furnace wall with wall-mounted air, making the current technology less than ideal for preventing high-temperature corrosion of the water-cooled walls. Therefore, the technical approach of preventing high-temperature corrosion simply by increasing wall-mounted airflow still has room for improvement. Summary of the Invention

[0003] The purpose of this invention is to provide a high-temperature oxygen plasma removal device for high-temperature corrosion treatment of water-cooled walls to remove CO and H2S. The device sprays plasma containing active oxygen free radicals into the upper water-cooled wall area of ​​the furnace, which is prone to high-temperature corrosion, through a short soot blower. In the furnace, the oxygen-containing plasma undergoes a non-equilibrium gas-phase oxidation reaction with the reducing gases CO and H2S, thereby achieving efficient and timely removal of CO and H2S.

[0004] Another objective of this invention is to provide a method for treating high-temperature corrosion of water-cooled walls by removing CO and H2S using high-temperature oxygen plasma.

[0005] The technical solution adopted in this invention is a high-temperature oxygen plasma removal device for CO and H2S removal from water-cooled walls to treat high-temperature corrosion. This device includes multiple flue gas reducing atmosphere measuring points located at corresponding positions on the upper water-cooled wall of the furnace. At each flue gas reducing atmosphere measuring point, a corresponding sampling hole is opened on the furnace. Multiple sampling holes are connected to a flue gas analyzer via pipes. The inner tube of a short sootblower inside the furnace is connected to a non-transfer arc DC arc oxygen plasma generator via a plasma pipe. The non-transfer arc DC arc oxygen plasma generator and the flue gas analyzer are connected to a control module via wires.

[0006] Preferably, each sampling port is equipped with a sampling connector, and the flue gas analyzer is connected to the sampling connector via a pipe.

[0007] Preferably, the non-transfer arc DC arc oxygen plasma generator is also connected to an oxygen source via a pipeline.

[0008] Preferably, an oxygen flow electric regulating valve is installed on the pipeline between the oxygen source and the non-transfer arc DC arc oxygen plasma generator, and the oxygen flow electric regulating valve is connected to the control module through a wire.

[0009] Preferably, the flue gas analyzer is also connected to a DCS display via wires.

[0010] Preferably, the control module includes a CO and H2S concentration analysis submodule, a non-transfer arc DC arc oxygen plasma generator power regulation submodule, and an oxygen flow electric regulating valve opening monitoring submodule. The flue gas analyzer is connected to the CO and H2S concentration analysis submodule via wires. The CO and H2S concentration analysis submodule is connected to the non-transfer arc DC arc oxygen plasma generator power regulation submodule and the oxygen flow electric regulating valve opening monitoring submodule via wires, respectively. The non-transfer arc DC arc oxygen plasma generator power regulation submodule and the oxygen flow electric regulating valve opening monitoring submodule are respectively connected to the non-transfer arc DC arc oxygen plasma generator and the oxygen flow electric regulating valve via wires.

[0011] The second technical solution adopted in this invention is a high-temperature oxygen plasma method for treating high-temperature corrosion of water-cooled walls by removing CO and H2S. Using the aforementioned high-temperature oxygen plasma device for removing CO and H2S from water-cooled walls, during boiler operation, the non-transfer arc DC arc oxygen plasma generator and the oxygen flow electric regulating valve are in servo mode, and the flue gas analyzer is always running. Real-time sampling of coal-fired flue gas is performed at the reducing atmosphere measurement point. The flue gas analyzer detects the concentrations of CO and H2S in the collected coal-fired flue gas and transmits these concentrations to the control module in real time. The control module adjusts the power of the non-transfer arc DC arc oxygen plasma generator and the opening degree of the oxygen flow electric regulating valve based on the CO and H2S concentrations.

[0012] Preferably, the concentrations of CO and H2S in the collected coal-fired flue gas are detected in a flue gas analyzer. The flue gas analyzer transmits the detected CO and H2S concentrations to the CO and H2S concentration analysis submodule in real time. The CO and H2S concentration analysis submodule performs concentration analysis and transmits the concentration analysis results to the non-transfer arc DC arc oxygen plasma generator power regulation submodule and the oxygen flow electric regulating valve opening monitoring submodule, respectively. The non-transfer arc DC arc oxygen plasma generator power regulation submodule and the oxygen flow electric regulating valve opening monitoring submodule make judgments based on the concentration analysis results and adjust the power of the non-transfer arc DC arc oxygen plasma generator and the opening of the oxygen flow electric regulating valve to inject oxygen plasma into the furnace through a short soot blower.

[0013] Preferably, the CO and H2S concentration analysis submodule is set with a CO concentration threshold of 5000ppm and an H2S concentration threshold of 200ppm. If the flue gas analyzer detects at least one CO and H2S concentration that is greater than or equal to the corresponding concentration threshold, the water-cooled wall is considered to have a high-temperature corrosion risk; otherwise, it is considered not to have a high-temperature corrosion risk.

[0014] Preferably, if the analysis results of the CO and H2S concentration analysis submodule indicate that there is a risk of high-temperature corrosion in the water-cooled wall, the power adjustment submodule of the non-transfer arc DC arc oxygen plasma generator and the oxygen flow electric regulating valve opening monitoring submodule adjust the power of the non-transfer arc DC arc oxygen plasma generator and the opening of the oxygen flow electric regulating valve according to the results.

[0015] Specifically: If the CO and H2S concentration analysis submodule indicates a risk of high-temperature corrosion in the water-cooled wall, the non-transferring arc DC arc oxygen plasma generator power regulation submodule controls the start of the non-transferring arc DC arc oxygen plasma generator and the oxygen flow electric regulating valve opening monitoring submodule controls the opening of the oxygen flow electric regulating valve to a certain degree. CO and H2S concentrations are continuously monitored for a certain period. If the concentration exceeding the threshold continues to increase, the power of the non-transferring arc DC arc oxygen plasma generator and the opening of the oxygen flow electric regulating valve are further increased until the concentration exceeding the threshold decreases. At this point, the current power and opening are maintained, and CO and H2S concentrations are continuously monitored. When the corresponding concentration drops below the threshold, the non-transferring arc DC arc oxygen plasma generator and the oxygen flow electric regulating valve are controlled to re-enter servo mode to save energy and oxygen. If the analysis results of the CO and H2S concentration analysis submodule indicate that there is no risk of high-temperature corrosion to the water-cooled wall, the non-transfer arc DC arc oxygen plasma generator and the oxygen flow electric regulating valve will continue to maintain servo status and continuously collect and monitor CO and H2S concentrations in real time.

[0016] The beneficial effects of this invention are: This invention utilizes a plasma generator located outside the furnace to crack an oxygen-containing carrier gas to generate plasma. O、 OH, O2 + The system utilizes oxygen-containing, high-temperature, stable, and active plasma. Active oxygen-containing free radicals are sprayed onto the upper water-cooled wall region of the furnace, which is prone to high-temperature corrosion, via a short sootblower. In a furnace environment of approximately 1200℃, the high-temperature oxygen-containing plasma undergoes a non-equilibrium gas-phase oxidation reaction with reducing gases such as CO and H2S in the flue gas, converting CO to CO2 and oxidizing H2S to SO2 and H2O, achieving efficient and rapid removal of CO and H2S. Simultaneously, a dense oxide protective film is formed on the surface of the water-cooled wall tubes, further inhibiting the occurrence of high-temperature sulfide corrosion.

[0017] This invention does not rely on traditional gas-phase oxidants such as O2, and can achieve online removal of CO and H2S. It also has a fast reaction speed, does not damage the water-cooled wall substrate, causes no secondary pollution, has strong adaptability, and has low complexity in modifying existing equipment. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the high-temperature corrosion treatment device for water-cooled walls to remove CO and H2S using high-temperature oxygen plasma according to the present invention. Figure 2 This is a flowchart of the high-temperature corrosion treatment method for water-cooled walls to remove CO and H2S using high-temperature oxygen plasma, as described in this invention.

[0019] In the diagram: 1. Furnace, 2. Flue gas reducing atmosphere measuring point, 3. Short soot blower, 4. Flue gas analyzer, 5. Non-transfer arc DC arc oxygen plasma generator, 6. Control module, 7. Oxygen flow electric regulating valve, 8. Oxygen source, 9. DCS display. Detailed Implementation

[0020] The following detailed description is provided in conjunction with specific implementation methods.

[0021] Example 1 This invention discloses a high-temperature oxygen plasma removal device for treating high-temperature corrosion of water-cooled walls, the structure of which is as follows: Figure 1 As shown, the furnace includes multiple flue gas reducing atmosphere measuring points 2 set at corresponding positions on the upper water-cooled wall of the furnace 1. At each flue gas reducing atmosphere measuring point 2, a corresponding collection hole is opened on the furnace 1. Multiple collection holes are connected to a flue gas analyzer 4 through pipes. The inner tube of the short soot blower 3 in the furnace 1 is connected to a non-transfer arc DC arc oxygen plasma generator 5 through a plasma pipe. The non-transfer arc DC arc oxygen plasma generator 5 and the flue gas analyzer 4 are connected to a control module 6 through wires.

[0022] This invention utilizes a plasma generator located outside the furnace to crack an oxygen-containing carrier gas to generate plasma. O、 OH, O2 + The system utilizes oxygen-containing, high-temperature, stable, and active plasma. Active oxygen-containing free radicals are sprayed onto the upper water-cooled wall region of the furnace, which is prone to high-temperature corrosion, via a short sootblower. In a furnace environment of approximately 1200℃, the high-temperature oxygen-containing plasma undergoes a non-equilibrium gas-phase oxidation reaction with reducing gases such as CO and H2S in the flue gas, converting CO to CO2 and oxidizing H2S to SO2 and H2O, achieving efficient and rapid removal of CO and H2S. Simultaneously, a dense oxide protective film is formed on the surface of the water-cooled wall tubes, further inhibiting the occurrence of high-temperature sulfide corrosion.

[0023] The short sootblower includes components such as a drive unit (motor and gearbox), a travel box, a threaded gun barrel, a gooseneck valve, a nozzle assembly, a wall box, and an inner tube stroke control mechanism. The inner tube and the threaded gun barrel are nested together. The inner tube is fixed, while the threaded gun barrel extends into the furnace to deliver the gas from the inner tube to the furnace.

[0024] The non-transfer arc DC arc oxygen plasma generator 5, also known as an oxygen plasma torch, includes a cathode assembly, an anode assembly, an arc cavity, a nozzle, a gas path system, a water cooling system, an arc ignition system, and a power supply system.

[0025] The CO and H2S flue gas analyzer 4 includes a pre-filter, a suction pump, and a flue gas component detection system. Each sampling port is equipped with a sampling connector, and the flue gas analyzer 4 is connected to the sampling connector via a pipe.

[0026] The non-transfer arc DC arc oxygen plasma generator 5 is also connected to an oxygen source 8 via a pipeline.

[0027] An electric oxygen flow regulating valve 7 is installed on the pipeline between the oxygen source 8 and the non-transfer arc DC arc oxygen plasma generator 5. The electric oxygen flow regulating valve 7 is connected to the control module 6 via a wire.

[0028] The oxygen flow electric regulating valve includes a motor, actuator, local opening indicator, and DCS remote signal measuring point.

[0029] The flue gas analyzer 4 is also connected to a DCS display 9 via wires.

[0030] The DCS display 9 is used to feed back the real-time monitored CO and H2S concentrations to the operators, enabling real-time monitoring of CO and H2S concentrations.

[0031] Example 2 This invention discloses a high-temperature oxygen plasma removal device for treating high-temperature corrosion of water-cooled walls, the structure of which is as follows: Figure 1 As shown, the furnace includes multiple flue gas reducing atmosphere measuring points 2 set at corresponding positions on the upper water-cooled wall of the furnace 1. At each flue gas reducing atmosphere measuring point 2, a corresponding collection hole is opened on the furnace 1. Multiple collection holes are connected to a flue gas analyzer 4 through pipes. The inner tube of the short soot blower 3 in the furnace 1 is connected to a non-transfer arc DC arc oxygen plasma generator 5 through a plasma pipe. The non-transfer arc DC arc oxygen plasma generator 5 and the flue gas analyzer 4 are connected to a control module 6 through wires.

[0032] The CO and H2S flue gas analyzer 4 includes a pre-filter, a suction pump, and a flue gas component detection system. The non-transfer arc DC arc oxygen plasma generator 5, also known as an oxygen plasma torch, includes a cathode assembly, an anode assembly, an arc cavity, a nozzle, a gas path system, a water cooling system, an arc ignition system, and a power supply system.

[0033] Each sampling port is equipped with a sampling connector, and the flue gas analyzer 4 is connected to the sampling connector via a pipe.

[0034] The non-transfer arc DC arc oxygen plasma generator 5 is also connected to an oxygen source 8 via a pipeline.

[0035] An electric oxygen flow regulating valve 7 is installed on the pipeline between the oxygen source 8 and the non-transfer arc DC arc oxygen plasma generator 5. The electric oxygen flow regulating valve 7 is connected to the control module 6 via a wire.

[0036] The oxygen flow electric regulating valve includes a motor, actuator, local opening indicator, and DCS remote signal measuring point.

[0037] The flue gas analyzer 4 is also connected to a DCS display 9 via wires.

[0038] The DCS display 9 is used to feed back the real-time monitored CO and H2S concentrations to the operators, enabling real-time monitoring of CO and H2S concentrations.

[0039] The control module 6 includes a CO and H2S concentration analysis submodule, a non-transfer arc DC arc oxygen plasma generator power regulation submodule, and an oxygen flow electric regulating valve opening monitoring submodule. The flue gas analyzer 4 is connected to the CO and H2S concentration analysis submodule via wires. The CO and H2S concentration analysis submodule is connected to the non-transfer arc DC arc oxygen plasma generator power regulation submodule and the oxygen flow electric regulating valve opening monitoring submodule via wires, respectively. The non-transfer arc DC arc oxygen plasma generator power regulation submodule and the oxygen flow electric regulating valve opening monitoring submodule are respectively connected to the non-transfer arc DC arc oxygen plasma generator 5 and the oxygen flow electric regulating valve 7 via wires.

[0040] Example 3 This invention relates to a method for treating high-temperature corrosion of water-cooled walls by removing CO and H2S using high-temperature oxygen plasma. The process is as follows: Figure 2 As shown, the high-temperature corrosion treatment device for water-cooled walls using high-temperature oxygen plasma to remove CO and H2S in Example 2 is employed. During boiler operation, the non-transfer arc DC arc oxygen plasma generator 5 and the oxygen flow electric regulating valve 7 are in servo mode, and the flue gas analyzer 4 is always in operation. The coal-fired flue gas is collected in real time at the reducing atmosphere measuring point 2. The concentration of CO and H2S in the collected coal-fired flue gas is detected in the flue gas analyzer 4, and the concentration of CO and H2S is transmitted to the control module 6 in real time. The control module 6 controls and adjusts the power of the non-transfer arc DC arc oxygen plasma generator 5 and the opening degree of the oxygen flow electric regulating valve 7 according to the concentration of CO and H2S.

[0041] The flue gas analyzer 4 detects the concentrations of CO and H2S in the collected coal-fired flue gas. The flue gas analyzer 4 transmits the detected CO and H2S concentrations to the CO and H2S concentration analysis submodule in real time. The CO and H2S concentration analysis submodule performs concentration analysis and transmits the concentration analysis results to the non-transfer arc DC arc oxygen plasma generator power regulation submodule and the oxygen flow electric regulating valve opening monitoring submodule, respectively. The non-transfer arc DC arc oxygen plasma generator power regulation submodule and the oxygen flow electric regulating valve opening monitoring submodule make judgments based on the concentration analysis results and adjust the power of the non-transfer arc DC arc oxygen plasma generator 5 and the opening of the oxygen flow electric regulating valve 7 to inject oxygen plasma into the furnace 1 through the short soot blower 3.

[0042] The CO and H2S concentration analysis submodule is set with a CO concentration threshold of 5000 ppm and an H2S concentration threshold of 200 ppm. If the CO and H2S concentrations detected by the flue gas analyzer 4 are at least greater than or equal to the corresponding concentration thresholds, the water-cooled wall is considered to be at risk of high-temperature corrosion; otherwise, it is considered not to be at risk of high-temperature corrosion.

[0043] If the analysis results of the CO and H2S concentration analysis submodule indicate that there is a risk of high-temperature corrosion in the water-cooled wall, the power adjustment submodule of the non-transfer arc DC arc oxygen plasma generator and the oxygen flow electric regulating valve opening monitoring submodule will adjust the power of the non-transfer arc DC arc oxygen plasma generator 5 and the opening of the oxygen flow electric regulating valve 7 according to the results. Specifically: If the CO and H2S concentration analysis submodule indicates a risk of high-temperature corrosion in the water-cooled wall, the non-transferring arc DC arc oxygen plasma generator power regulation submodule controls the start of the non-transferring arc DC arc oxygen plasma generator 5, and the oxygen flow electric regulating valve opening monitoring submodule controls the opening of the oxygen flow electric regulating valve 7 to a certain degree. CO and H2S concentrations are continuously monitored for a certain period. If the concentration exceeding the threshold continues to increase (for example, if the concentration exceeding the threshold continues to increase after one minute of operation, it indicates that the opening and power are not very effective, and the power and oxygen flow need to be increased), the power of the non-transferring arc DC arc oxygen plasma generator 5 and the opening of the oxygen flow electric regulating valve 7 are further increased until the concentration exceeding the threshold decreases. At this point, the current power and opening are maintained, and the CO and H2S concentrations are continuously monitored. When the corresponding concentration drops below the threshold, the non-transferring arc DC arc oxygen plasma generator 5 and the oxygen flow electric regulating valve 7 are controlled to re-enter servo mode to save energy and oxygen. If the analysis results of the CO and H2S concentration analysis submodule indicate that there is no risk of high-temperature corrosion to the water-cooled wall, then the non-transfer arc DC arc oxygen plasma generator 5 and the oxygen flow electric regulating valve 7 will continue to maintain servo status and continuously collect and monitor CO and H2S concentrations in real time.

[0044] Figure 2 The "CO and H2S Concentration Analysis Submodule" has a CO concentration threshold set to 5000 ppm and an H2S concentration threshold set to 200 ppm, pre-set in this module. Currently, in engineering practice, a CO concentration greater than 5000 ppm or an H2S concentration greater than 200 ppm is generally considered a risk of high-temperature corrosion for water-cooled walls. Therefore, this standard is adopted as the criterion for determining whether to perform oxygen plasma injection operation.

[0045] Figure 2 The "non-transfer arc DC arc oxygen plasma generator power adjustment submodule" and the "oxygen flow electric regulating valve opening monitoring submodule" can judge based on the CO and H2S concentrations and reasonably adjust the corresponding generator power and valve opening, thereby ensuring that the reducing gas concentration on the water-cooled wall surface inside the furnace is always kept within a safe range (CO less than 5000ppm, H2S less than 200ppm), thus fundamentally alleviating the occurrence of high-temperature corrosion of the wall-mounted water-cooled wall.

[0046] Figure 2 Medium- and high-temperature oxygen plasma can enter through a connecting main pipe into a branch pipe installed on a short sootblower. After entering the furnace through the short sootblower, the oxygen plasma is sprayed near the water-cooled wall. This avoids the need to set up additional furnace-internal and external passages on the water-cooled wall, greatly reducing modification investment and subsequent maintenance costs.

[0047] Figure 2The DCS screen is transmitted to the central control room, allowing operators to monitor the concentrations of CO and H2S near the upper water-cooled wall of the furnace in real time. At the same time, historical data on the concentration of reducing gases can be retrieved, providing data reference for operators to adjust the boiler operation mode, thereby improving the operators' operational level.

[0048] Example 4 Based on Example 3, if it is a tangential combustion boiler, then the reducing atmosphere measurement points 2 for flue gas need to be arranged on all four furnace walls of the tangential combustion boiler. If it is a counter-current combustion boiler with front and rear walls, then the reducing atmosphere measurement points 2 for flue gas only need to be arranged on the two side walls of the counter-current combustion boiler.

[0049] Example 5 A 300MW coal-fired boiler uses a tangential combustion method and has been burning high-sulfur coal for a long time. Severe sulfidation corrosion has appeared on the water-cooled wall in the burner area. The CO concentration in the wall-attached area was measured to be 5.2% (52,000 ppm) and the H2S concentration was 340 ppm.

[0050] At the boiler burner elevation, four sets of the high-temperature oxygen plasma CO and H2S removal devices of this invention, as described in Example 4, are horizontally arranged along the water-cooled wall. Oxygen is used as the plasma source, and each set has a power of 30kW. After the system is put into operation, CO in the wall-adhering area drops below 2000ppm, and H2S drops below 150ppm. The water-cooled wall surface changes from a reducing atmosphere to a weakly oxidizing atmosphere, and the high-temperature corrosion rate decreases by more than 85%, achieving highly efficient treatment of high-temperature corrosion in the water-cooled wall area.

[0051] Example 6 A 660MW supercritical boiler features opposed-flow combustion along its front and rear walls. The water-cooled walls on both sides exhibit a strong reducing atmosphere, leading to CO and H2S enrichment and frequent tube ruptures. Six sets of the high-temperature oxygen plasma CO and H2S removal devices for water-cooled wall corrosion control, based on this invention, were layered along the high-corrosion zones on both sides. Operational results show that under high load, the oxygen volume fraction in the wall-adhering zone increased to 3%, and the CO concentration on the left wall decreased from 13% (130,000 ppm) to 4,800 ppm, fundamentally suppressing high-temperature corrosion of the water-cooled walls.

[0052] Example 7 A circulating fluidized bed boiler burning high-sulfur coal gangue suffers from severe sulfidation and high-temperature corrosion of the water-cooled walls in the lower part of the furnace, resulting in rapid wall thinning. By arranging the device of this invention above the dense phase zone of the furnace, the concentrations of CO and H2S are significantly reduced, eliminating the need for frequent spraying or welding repairs and greatly reducing maintenance costs.

[0053] Example 8 Comprehensive Treatment of High-Temperature Corrosion in Waste Incineration Boilers: The flue gas from a certain waste incineration boiler contains complex sulfur and carbon components, resulting in severe synergistic high-temperature corrosion and surface fouling of the water-cooled walls. The device in Embodiment 3 of this invention is arranged in the high-temperature corrosion zone of the furnace, utilizing high-temperature oxygen plasma to simultaneously oxidize CO, H2S, and some combustible reducing substances, thus both inhibiting corrosion and promoting the combustion rate of combustibles. After commissioning, the corrosion rate of the water-cooled walls was significantly reduced, and the coupled problem of water-cooled wall fouling and high-temperature corrosion was simultaneously and significantly improved.

[0054] Example 9 A boiler has been burning anthracite and lean coal for a long time, resulting in low volatile matter content, difficulty in ignition, severe local oxygen deficiency in the water-cooled wall area, high CO concentration on the wall, and accelerated high-temperature corrosion. The device described in Embodiment 3 of this invention is arranged in the burner area to directly supply high-temperature oxygen plasma to the reducing region. Without changing the boiler's main air distribution, the local atmosphere in the water-cooled wall area is significantly improved, achieving rapid removal of CO and H2S, and long-term control of high-temperature corrosion of the water-cooled wall.

[0055] Example 10 A certain cogeneration boiler experiences significant load fluctuations. Under high load conditions, the reducing atmosphere of the water-cooled walls intensifies, leading to exacerbated high-temperature corrosion. The device of this invention employs a zoned, time-based, and on-demand operation mode. While ensuring effective corrosion control, it simultaneously reduces the device's energy and oxygen consumption, achieving a balance between high-temperature corrosion control and economical boiler operation.

[0056] This invention utilizes a plasma generator located outside the furnace to crack an oxygen-containing carrier gas to generate plasma. O、 OH, O2 + The system utilizes oxygen-containing, high-temperature, stable, and active plasma. Active oxygen-containing free radicals are sprayed onto the upper water-cooled wall region of the furnace, which is prone to high-temperature corrosion, via a short sootblower. In a furnace environment of approximately 1200℃, the high-temperature oxygen-containing plasma undergoes a non-equilibrium gas-phase oxidation reaction with reducing gases such as CO and H2S in the flue gas, converting CO to CO2 and oxidizing H2S to SO2 and H2O, achieving efficient and rapid removal of CO and H2S. Simultaneously, a dense oxide protective film is formed on the surface of the water-cooled wall tubes, further inhibiting the occurrence of high-temperature sulfide corrosion.

[0057] This invention does not rely on traditional gaseous oxidants such as O2. Unlike simple oxygen supplementation or wall-mounted air technology, high-temperature oxygen plasma, as a plasma state substance that is distinct from gaseous, liquid, and solid substances, can still exist stably at high furnace temperatures. Moreover, its reactivity with CO and H2S is much higher than that of O2 in traditional air. It can achieve online, efficient, and rapid removal of CO and H2S without shutting down the boiler. Furthermore, it has the advantages of fast reaction speed, no damage to water-cooled wall substrate, no secondary pollution, and strong adaptability.

Claims

1. A high-temperature oxygen plasma removal of CO, H2S water-cooled wall high-temperature corrosion treatment device, characterized in that, The furnace includes multiple flue gas reducing atmosphere measuring points (2) set at the corresponding positions of the upper water-cooled wall of the furnace (1). At each of the flue gas reducing atmosphere measuring points (2), a corresponding collection hole is opened on the furnace (1). The multiple collection holes are connected to a flue gas analyzer (4) through pipes. The inner tube of the short soot blower (3) in the furnace (1) is connected to a non-transfer arc DC arc oxygen plasma generator (5) through a plasma pipe. The non-transfer arc DC arc oxygen plasma generator (5) and the flue gas analyzer (4) are connected to a control module (6) through wires.

2. The high-temperature oxygen plasma CO and H2S removal device for water-cooled wall high-temperature corrosion control according to claim 1, characterized in that, Each of the collection holes is equipped with a collection connector, and the flue gas analyzer (4) is connected to the collection connector through a pipe.

3. The high-temperature oxygen plasma removal device for CO and H2S in water-cooled walls as described in claim 1, characterized in that, The non-transfer arc DC arc oxygen plasma generator (5) is also connected to an oxygen source (8) via a pipeline.

4. The high-temperature oxygen plasma removal device for CO and H2S removal in water-cooled walls as described in claim 3, characterized in that, An oxygen flow electric regulating valve (7) is installed on the pipeline between the oxygen source (8) and the non-transfer arc DC arc oxygen plasma generator (5), and the oxygen flow electric regulating valve (7) is connected to the control module (6) through a wire.

5. The high-temperature oxygen plasma removal device for CO and H2S in water-cooled walls as described in claim 4, characterized in that, The flue gas analyzer (4) is also connected to a DCS display (9) via wires.

6. The high-temperature oxygen plasma removal device for CO and H2S in water-cooled walls as described in claim 5, characterized in that, The control module (6) includes a CO and H2S concentration analysis submodule, a non-transfer arc DC arc oxygen plasma generator power adjustment submodule, and an oxygen flow electric regulating valve opening monitoring submodule. The flue gas analyzer (4) is connected to the CO and H2S concentration analysis submodule via wires. The CO and H2S concentration analysis submodule is connected to the non-transfer arc DC arc oxygen plasma generator power adjustment submodule and the oxygen flow electric regulating valve opening monitoring submodule via wires. The non-transfer arc DC arc oxygen plasma generator power adjustment submodule and the oxygen flow electric regulating valve opening monitoring submodule are respectively connected to the non-transfer arc DC arc oxygen plasma generator (5) and the oxygen flow electric regulating valve (7) via wires.

7. A method for treating high-temperature corrosion of water-cooled walls by removing CO and H2S using high-temperature oxygen plasma, characterized in that, Using the high-temperature oxygen plasma CO and H2S removal device for water-cooled wall high-temperature corrosion treatment as described in claim 6, during boiler operation, the non-transfer arc DC arc oxygen plasma generator (5) and the oxygen flow electric regulating valve (7) are in servo mode. The coal-fired flue gas is collected in real time at the flue gas reducing atmosphere measuring point (2). The concentration of CO and H2S in the collected coal-fired flue gas is detected in the flue gas analyzer (4), and the concentration of CO and H2S is transmitted to the control module (6) in real time. The control module (6) controls and adjusts the power of the non-transfer arc DC arc oxygen plasma generator (5) and the opening degree of the oxygen flow electric regulating valve (7) according to the concentration of CO and H2S.

8. The method for treating high-temperature corrosion of water-cooled walls by removing CO and H2S using high-temperature oxygen plasma according to claim 7, characterized in that, The flue gas analyzer (4) detects the concentrations of CO and H2S in the collected coal-fired flue gas. The flue gas analyzer (4) transmits the detected CO and H2S concentrations to the CO and H2S concentration analysis submodule in real time. The CO and H2S concentration analysis submodule performs concentration analysis and transmits the concentration analysis results to the non-transfer arc DC arc oxygen plasma generator power adjustment submodule and the oxygen flow electric regulating valve opening monitoring submodule, respectively. The non-transfer arc DC arc oxygen plasma generator power adjustment submodule and the oxygen flow electric regulating valve opening monitoring submodule make judgments based on the concentration analysis results and adjust the power of the non-transfer arc DC arc oxygen plasma generator (5) and the opening of the oxygen flow electric regulating valve (7) to inject oxygen plasma into the furnace (1) through the short soot blower (3).

9. The method for treating high-temperature corrosion of water-cooled walls by removing CO and H2S using high-temperature oxygen plasma according to claim 8, characterized in that, The CO and H2S concentration analysis submodule is set with a CO concentration threshold of 5000ppm and an H2S concentration threshold of 200ppm. If the flue gas analyzer (4) detects at least one CO concentration and H2S concentration greater than or equal to the corresponding concentration threshold, the water-cooled wall is considered to have a high-temperature corrosion risk; otherwise, it is considered not to have a high-temperature corrosion risk.

10. The method for treating high-temperature corrosion of water-cooled walls by removing CO and H2S using high-temperature oxygen plasma according to claim 9, characterized in that, If the analysis results of the CO and H2S concentration analysis submodule indicate that there is a risk of high-temperature corrosion in the water-cooled wall, the power adjustment submodule of the non-transfer arc DC arc oxygen plasma generator and the oxygen flow electric regulating valve opening monitoring submodule will adjust the power of the non-transfer arc DC arc oxygen plasma generator (5) and the opening of the oxygen flow electric regulating valve (7) according to the results. Specifically: If the analysis result of the CO and H2S concentration analysis submodule is that there is a risk of high temperature corrosion in the water-cooled wall, the non-transfer arc DC arc oxygen plasma generator power regulation submodule controls the start of the non-transfer arc DC arc oxygen plasma generator (5) and the oxygen flow electric regulating valve opening monitoring submodule controls the oxygen flow electric regulating valve (7) to open to a certain degree. The CO and H2S concentrations are monitored for a certain period of time. If the concentration exceeding the threshold is still increasing, the power of the non-transfer arc DC arc oxygen plasma generator (5) and the opening of the oxygen flow electric regulating valve (7) are increased until the concentration exceeding the threshold decreases. At this time, the current power and opening are maintained, and the CO and H2S concentrations are continuously monitored. When the corresponding concentration is reduced to below the threshold, the non-transfer arc DC arc oxygen plasma generator (5) and the oxygen flow electric regulating valve (7) are controlled to re-enter the servo state. If the analysis results of the CO and H2S concentration analysis submodule indicate that there is no risk of high-temperature corrosion of the water-cooled wall, the non-transfer arc DC arc oxygen plasma generator (5) and the oxygen flow electric regulating valve (7) continue to maintain servo status and continuously collect and monitor CO and H2S concentrations in real time.

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