A method and device for grading oxygen supplement and turbulence enhancement of a waste incinerator under a high-altitude hypoxic environment

Abstract

The present application belongs to the field of household garbage incineration disposal and energy-saving and environment-friendly technology, and specifically discloses a method and device for staged oxygen supplement and turbulent flow enhancement of a garbage incinerator under a plateau hypoxic environment, which comprises the steps of staged pretreatment, three-stage layered oxygen supplement, double turbulent flow enhancement disturbance, self-adaptive regulation and control of hearth temperature, and flue gas waste heat recovery, etc. By setting a differential oxygen supply structure at the bottom, middle and upper parts of the hearth, precise oxygen supply matching in different combustion stages is realized. In combination with an inclined cyclone air port and a high-temperature-resistant spoiler structure, the gas-solid two-phase turbulent flow mixing in the hearth is enhanced, the laminar flow combustion state is improved, the heat and mass transfer efficiency is improved, and the residence time of flue gas in the high-temperature zone is prolonged, so as to promote the full reaction of combustible components and the deep decomposition of pollutants. The present application can effectively improve the combustion stability and uniformity of the garbage incineration process under the plateau hypoxic condition, improve the burnout effect, reduce the comprehensive energy consumption, and improve the pollutant control level.

Description

Technical Field

[0001] This invention relates to the field of municipal solid waste incineration and energy conservation and environmental protection technology, and in particular to a method and apparatus for staged oxygen supplementation and turbulence enhancement in a waste incinerator under high-altitude and low-oxygen conditions. Background Technology

[0002] The Qinghai-Tibet Plateau and the Western Sichuan Plateau in my country possess distinct environmental characteristics. These regions are characterized by high altitude, low atmospheric pressure, and low oxygen levels; under the same temperature conditions, the oxygen content is only 60-75% of that in plains areas. They also suffer from low air density, weak atmospheric convection, and consistently low temperatures. With the advancement of urbanization in plateau towns, the dispersed population structure has become increasingly prominent, leading to a year-on-year increase in the annual volume of domestic waste. This waste is complex, primarily consisting of mixed solid waste from kitchen waste, plastics, textiles, and straw. It generally exhibits high moisture content, large fluctuations in calorific value, and poor combustion stability, posing a significant challenge to the localized and harmless incineration and disposal of waste.

[0003] Currently, conventional waste incinerator combustion processes are mostly adapted to the normal pressure, oxygen-rich environment of plains, and their direct application in plateau regions presents numerous technical challenges. Single oxygen supply method: Traditional incinerators mostly use a single-stage bottom air supply for oxygen supplementation. The oxygen supply is concentrated, and the oxygen content in the upper part of the furnace is scarce. The volatile matter in the waste is difficult to burn completely, which easily produces harmful gases such as black smoke and carbon monoxide.

[0004] Poor airflow: Due to insufficient aerodynamics at high altitudes, the airflow inside the furnace is in a laminar state, the flue gas mixing disturbance is weak, the combustible components do not come into sufficient contact with oxygen, the combustion residence time is short, and the waste combustion rate is low.

[0005] Poor furnace temperature stability: The furnace combustion temperature is low in a low-oxygen environment, and the furnace temperature is below 850℃ under normal operating conditions, which cannot meet the conditions for high-temperature decomposition of dioxins, resulting in excessive emissions of toxic pollutants.

[0006] High energy consumption and costs: Existing high-pressure air supply equipment is suitable for plains conditions, but the wind pressure loss is large at high altitudes, resulting in a significant increase in air supply energy consumption. The equipment is also prone to icing and aging, leading to high operation and maintenance costs.

[0007] Currently, many high-altitude incineration equipment systems employ oxygen supplementation methods such as increasing air volume and pressure. However, simply increasing the air intake cannot solve the core problems of uneven oxygen distribution and weak airflow turbulence within the furnace. Furthermore, excessive cold air intake can lower the furnace temperature, exacerbate heat loss, and easily cause coking and corrosion in the furnace, thus shortening the equipment's service life. Currently, the industry lacks a systematic combustion process specifically adapted to the low-oxygen, low-pressure environment of high altitudes, which combines multi-stage precise oxygen supplementation with enhanced airflow turbulence. Summary of the Invention

[0008] The purpose of this invention is to provide a method and apparatus for staged oxygen supplementation and turbulence enhancement in a waste incinerator under high-altitude and low-oxygen conditions, so as to solve the technical problems of incomplete combustion, uneven oxygen distribution, insufficient flue gas disturbance capacity, poor furnace temperature stability, difficulty in achieving stable pollutant emission standards, and high system energy consumption in the existing technology of waste incineration under high-altitude and low-oxygen conditions.

[0009] To achieve the above objectives, this invention provides a method for staged oxygen supplementation and turbulence enhancement in a waste incinerator under high-altitude, low-oxygen conditions, comprising the following steps: S1. Collect domestic waste from highland towns and carry out waste classification and pretreatment; S2. A layered oxygen supply mode is adopted, which includes one oxygen supply at the bottom of the grate, two oxygen supplies in the middle of the furnace, and three oxygen supplies in the upper part of the furnace. The oxygen supply parameters are dynamically adapted and adjusted according to the low air pressure environment of the plateau. S3. A combination of airflow swirl and mechanical turbulence is used to create dual turbulent disturbances, thereby enhancing the turbulent field inside the furnace. S4. Temperature monitoring units are installed in the combustion zone and burnout zone of the furnace to collect furnace temperature data in real time, and the oxygen supply air volume and air intake ratio are dynamically adjusted according to the air pressure changes in the low-pressure environment of the plateau. S5. After combustion, the high-temperature flue gas is introduced into the tail flue after being disturbed by turbulence. Part of the high-temperature flue gas is circulated back to step S1, and the waste heat of the flue gas is used to dry the pre-treated waste. After purification, the flue gas is discharged in compliance with standards, and the incineration residue is collected and disposed of in a harmless manner.

[0010] Preferably, S1 includes the following steps: S11. Collect domestic waste from highland towns and classify it using a drum screener; separate and remove non-combustible impurities, including stones, metals, and glass; the undersize material then enters a twin-shaft shear crusher for crushing. S12. For the high-moisture components of kitchen waste in plateau urban waste, a pre-drying treatment using furnace waste heat recovery is adopted to reduce the moisture content of the waste to a range suitable for stable combustion. Specifically: High-temperature flue gas drawn from the tail flue of the incinerator is sent into a closed drying drum after being cyclone dust collector, where it is dried with waste with high moisture content. Inside the drying drum, the material is constantly turned over and evenly dispersed by the lifting plate structure, so that it is fully heated and the heat and mass transfer process is enhanced. After treatment, the moisture content of the waste is controlled to below 35%. S13. A low-temperature slow drying strategy is adopted to control the inlet temperature of hot flue gas below 200℃ to avoid the formation of a hard shell structure on the surface of the material due to instantaneous dehydration. The dried waste is temporarily stored in an insulated silo to reduce direct contact with the outside low-temperature air and inhibit moisture reabsorption and heat loss.

[0011] Preferably, S2 is as follows: The primary oxygen supply system located below the grate provides oxygen to the bottom of the grate. The primary oxygen supply system adopts a distributed air supply structure that is evenly arranged along the transverse and longitudinal directions of the grate to provide the oxygen required for initial combustion and drying to the waste layer. Secondary oxygen supply is carried out in the main combustion zone in the middle of the furnace through a secondary oxygen supply system. The secondary oxygen supply system uses multiple sets of inclined swirl-type oxygen supply vents evenly arranged along the circumference of the furnace to provide the air required for enhanced oxidation to the main combustion zone. The upper part of the furnace is oxygenated three times by a three-stage oxygen supply system located in the burnout zone. The three-stage oxygen supply system is arranged axially to supplement a small amount of oxygen in the mainstream direction of the flue gas, which is used to promote the deep oxidation process of the residual combustible components in the flue gas.

[0012] Preferably, the graded oxygen replenishment process adopts a layered oxygen supply mode of one oxygen replenishment at the bottom of the grate, a second oxygen replenishment in the middle of the furnace, and a third oxygen replenishment in the upper part of the furnace, and the oxygen supply parameters are dynamically adapted and adjusted according to the real-time monitored ambient atmospheric pressure. in: The primary oxygen supply is delivered through the primary air chamber below the grate, with the air volume accounting for 50-70% of the total volume. The air is delivered evenly and stably to provide the oxygen required for the main combustion zone of the waste layer and to penetrate the material layer. Secondary oxygen supply is injected from the front and rear walls or side walls in the middle of the furnace, with the air volume ratio controlled at 10-20%. The inclined swirl air supply is used to enhance the mixing turbulence of volatiles and oxygen. Three oxygen supplements are provided, supplied from the upper part of the furnace or the burnout zone, with the air volume ratio controlled at 20-30%. The air supply is arranged axially to oxidize the residual CO, H2 and volatile organic compounds in the burnout flue gas. Preferably, in S3, the airflow swirl is specifically as follows: The inclined swirl oxygen supply nozzles in the secondary oxygen supply system are evenly distributed along the circumference of the furnace and installed at an angle relative to the tangential direction of the furnace. This allows the oxygen supply flow entering the furnace to have both axial and tangential velocity components during injection, forming a stable annular swirl structure inside the furnace and enhancing the gas-solid two-phase mixing effect. This swirling structure generates strong rotational motion and backflow effect in the flue gas, enhancing the turbulence intensity inside the furnace. At the same time, the central backflow zone formed by the swirling structure is used to intercept some of the high-temperature flue gas and unburned combustible components, prolonging the residence time of the flue gas in the high-temperature reaction zone and strengthening the reaction process.

[0013] Preferably, in S3, the mechanical turbulence specifically refers to: A wave-shaped high-temperature resistant baffle plate is fixedly installed on the upper inner wall of the furnace. The baffle plate is made of heat-resistant steel or silicon carbide composite material and is arranged in layers along the height of the furnace. As the high-temperature flue gas flows upward, the wavy surface continuously changes the flow direction and velocity distribution of the flue gas, generating local vortices and stagnation effects on the back flow side of the baffle and at the troughs. This increases the probability of collision between unburned combustible components and residual oxygen, and prolongs the actual residence time of the flue gas in the high-temperature reaction zone.

[0014] Preferably, the oxygen-supplementing air for the first oxygen supply at the bottom of the grate, the second oxygen supply in the middle of the furnace, and the third oxygen supply in the upper part of the furnace is preheated using the residual heat of the furnace before entering the furnace.

[0015] The present invention also provides a staged oxygen supplementation and turbulence enhancement device for a waste incinerator in a high-altitude low-oxygen environment, including a feeding system, a furnace combustion system, a three-stage stratified oxygen supplementation system, a turbulence enhancement system, a temperature monitoring and control system, and a flue gas purification and waste heat recovery system. The feeding system includes a feeding hopper, a feeding device and an insulated silo connected in sequence, used to continuously and stably transport waste to the furnace combustion system; The furnace combustion system includes a grate and a furnace. The grate is located at the bottom of the furnace, and a furnace outlet is located above the furnace. An induced draft fan is connected to the furnace outlet. An ash outlet and an ash conveying mechanism are located at the bottom of the furnace. The three-stage stratified oxygen supply system includes a primary oxygen supply system located below the grate, a secondary oxygen supply system located in the lower part of the main combustion zone of the furnace, and a tertiary oxygen supply system located in the upper part of the burnout zone of the furnace. The turbulence enhancement system includes an airflow swirl structure and a mechanical turbulence structure. The airflow swirl structure is a secondary air nozzle installed at an inclined tangential angle, and the mechanical turbulence structure is a wave-shaped high-temperature resistant turbulence plate fixed in layers to the upper inner wall of the furnace. The temperature monitoring and control system includes several temperature sensors installed in the combustion zone and burnout zone of the furnace for real-time monitoring of the temperature inside the furnace. The flue gas purification and waste heat recovery system includes a waste heat boiler, a bag filter, a desulfurization and denitrification mechanism, and a chimney, which are connected in sequence to the secondary air duct.

[0016] Preferably, the primary oxygen supply system includes a primary air chamber located below the grate, wherein the primary air chamber supplies air to the bottom of the furnace through primary air nozzles; The secondary oxygen supply system includes a secondary air nozzle located in the lower part of the furnace, and the secondary air nozzle is connected to the air supply system through a secondary air duct. The three-stage oxygen replenishment system includes a tertiary air nozzle located at the top of the furnace for replenishing oxygen to the flue gas combustion zone; the secondary air nozzle is inclined, and a wave-shaped high-temperature resistant baffle is fixedly installed on the upper inner wall of the furnace.

[0017] Preferably, the high-temperature resistant baffle is made of heat-resistant steel or silicon carbide composite material.

[0018] Therefore, the present invention employs the above-mentioned method and apparatus for staged oxygen supplementation and turbulence enhancement in a waste incinerator under high-altitude low-oxygen conditions, and the beneficial effects are as follows: (1) This invention is designed for the characteristics of low pressure, low oxygen and low temperature in high plateau areas. It adopts waste classification pretreatment technology and a three-level layered differentiated oxygen supplementation mode to match the oxygen supply needs of the entire stages of waste drying, main combustion and burnout. It combines airflow swirl and mechanical disturbance to enhance turbulent mixing, which effectively improves the drawbacks of traditional laminar combustion, helps to solve the problems of combustion fluctuation and flameout in high plateau areas, and significantly improves the waste burnout rate.

[0019] (2) By extending the residence time of flue gas in the high-temperature zone and cooperating with adaptive furnace temperature control, the present invention can stably maintain the high-temperature working condition of the furnace, which can fully decompose toxic pollutants such as dioxins; at the same time, multi-stage precise oxygen supplementation avoids pollutants such as carbon monoxide and unburned carbon generated by local hypoxia. Combined with complete flue gas purification and waste heat treatment processes, it effectively reduces the smoke opacity and pollutant emissions, and meets the harmless and environmentally friendly incineration standards in plateau areas.

[0020] (3) This invention relies on the waste heat of flue gas to achieve pre-drying of garbage and preheating of combustion air, thereby achieving energy cascade utilization, greatly reducing additional energy consumption, and without the need to install high-pressure and high-power air supply equipment. Through structural optimization, the core problems of uneven oxygen supply and weak airflow disturbance on plateau can be solved. The equipment modification cost is low and the operation and maintenance are simple. It can effectively reduce the energy consumption of air supply and is suitable for small-scale incineration facilities in plateau towns.

[0021] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0022] Figure 1 This is an overall flowchart of an embodiment of the present invention of a method for staged oxygen supplementation and turbulence enhancement in a waste incinerator under high-altitude low-oxygen environment; Figure 2 This is a schematic diagram of a waste incinerator structure according to an embodiment of the present invention, which describes a staged oxygen supplementation and turbulence enhancement device for a waste incinerator in a high-altitude, low-oxygen environment.

[0023] Figure Labels 1. Feed hopper; 2. Feeding device; 3. Grate; 4. Primary air chamber; 5. Primary air nozzle; 6. Ash and slag outlet; 7. Ash and slag conveying mechanism; 8. Secondary air nozzle; 9. Secondary air duct; 10. Furnace; 11. Tertiary air nozzle; 12. Baffle plate; 13. Temperature sensor; 14. Furnace outlet; 15. Exhaust fan; 16. Waste heat boiler; 17. Baghouse dust collector; 18. Desulfurization and denitrification mechanism; 19. Chimney. Detailed Implementation

[0024] The technical solution of the present invention will be further described below with reference to the accompanying drawings and embodiments.

[0025] Unless otherwise defined, the technical or scientific terms used in this invention shall have the ordinary meaning understood by one of ordinary skill in the art to which this invention pertains. The terms "first," "second," and similar terms used in this invention do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Terms such as "comprising" or "including" mean that the element or object preceding the word encompasses the elements or objects listed following the word and their equivalents, without excluding other elements or objects. Terms such as "connected" or "linked" are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. Terms such as "upper," "lower," "left," and "right" are used only to indicate relative positional relationships; when the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0026] like Figure 1 As shown, a method for staged oxygen supplementation and turbulence enhancement in a waste incinerator under high-altitude, low-oxygen conditions includes a staged pretreatment process, a three-stage stratified oxygen supplementation process, a dual turbulence enhancement disturbance process, an adaptive furnace temperature control process, and a flue gas waste heat recovery process. This method is applicable to high-altitude, low-oxygen environments and can maintain stable combustion operation under low pressure, low oxygen, and low temperature conditions. The method is suitable for high-altitude areas of 2500-4500m, with an atmospheric pressure of 58-75kPa and an ambient temperature of -30-30℃. Specifically, it includes the following steps: S1. Graded Pre-treatment Process: Collect domestic waste from highland towns and carry out graded pre-treatment, including the following steps: S11. Collect domestic waste from plateau towns and send it to the pretreatment system. First, it is graded and screened by a drum screener to separate and remove large non-combustible impurities such as stones, metals, and glass. The undersize material then enters a twin-shaft shear crusher for further crushing.

[0027] S12. For the high-moisture components (moisture content > 80%) of kitchen waste in high-altitude urban waste, a furnace waste heat recovery pre-drying treatment is adopted to reduce the moisture content of the waste to a range suitable for stable combustion, thereby improving the calorific value and adapting to the low-temperature environment of the high altitude. Specifically: High-temperature flue gas (approximately 200°C) drawn from the tail flue of the incinerator is sent into a closed drying drum after being cyclone dust collector, where it is dried with waste with high moisture content. Inside the drying drum, the material is continuously turned over and evenly dispersed by the lifting plate structure, so that it is fully heated and the heat and mass transfer process is enhanced.

[0028] After treatment, the moisture content of the waste is controlled to below 35%; this ensures combustibility while avoiding unstable combustion caused by excessive moisture. All the heat required for the entire pre-drying process comes from the waste heat at the tail end of the incinerator, achieving cascaded energy utilization without the need for an external heating source, while also avoiding excessive drying that would lead to increased dust and higher system energy consumption.

[0029] S13. In high-altitude environments, due to lower atmospheric pressure, the boiling point of water is significantly reduced (e.g., approximately 86℃ at an altitude of about 4000m). Simultaneously, the phase change characteristics of water vaporization change, making the vaporization process more susceptible to limitations in heat and mass transfer. Based on these characteristics, this process employs a low-temperature, slow drying strategy, controlling the inlet temperature of the hot flue gas below 200℃ to prevent the formation of a hard shell structure on the material surface due to instantaneous dehydration. This prevents internal moisture from diffusing and migrating outward, ensuring the uniformity and stability of the overall drying process.

[0030] After drying, the waste is temporarily stored in an insulated silo. By reducing direct contact with the cold outside air, it effectively inhibits moisture reabsorption and heat loss, thus maintaining its calorific value stability and combustibility consistency. Through the integrated screening, crushing, and pre-drying process described above, the waste particle size distribution is more uniform, the fuel composition stability is significantly improved, and the proportion of organic matter is increased to a higher level, providing a good raw material foundation for reliable ignition, stable combustion, and complete combustion under the low-oxygen conditions of high altitude.

[0031] S2, Three-stage stratified oxygen supply process: A stratified oxygen supply mode is adopted, consisting of primary oxygen supply at the bottom of grate 3, secondary oxygen supply in the middle of furnace 10, and tertiary oxygen supply in the upper part of furnace 10. The oxygen supply parameters are dynamically adjusted according to the low-pressure environment of the plateau. Specifically: The present invention provides primary oxygen supply to the bottom of the grate 3 through a primary oxygen supply system located below the grate 3. The primary oxygen supply system adopts a distributed air supply structure evenly arranged along the transverse and longitudinal directions of the grate 3 to provide the oxygen required for initial combustion and drying of the waste layer.

[0032] This initial oxygen supplementation supports the oxidation reactions required during the drying, pyrolysis, and initial combustion stages of the waste, while maintaining stable ventilation in grate zone 3 to prevent incomplete combustion or coking caused by localized oxygen deficiency. In terms of operating parameters, the air volume ratio (total air) should be controlled at 50-70%, employing a uniform and stable air delivery method to ensure even air penetration into the waste material layer, thereby enhancing heat and mass transfer processes and improving the combustion uniformity on the grate 3 surface.

[0033] The present invention provides secondary oxygen supply to the middle part of the furnace 10 through a secondary oxygen supply system located in the lower part of the main combustion zone. The secondary oxygen supply system uses multiple sets of inclined swirl-type oxygen supply nozzles evenly arranged around the circumference of the furnace 10 to provide the air required for enhanced oxidation to the main combustion zone.

[0034] This secondary oxygen supply structure creates a swirling jet, causing intense turbulent mixing between the air entering the furnace 10 and the high-temperature combustible gas, thereby significantly improving the combustion reaction rate and mixing efficiency. Secondary oxygen supply primarily functions during the concentrated release of volatiles and the rapid oxidation of coke, making it a crucial oxygen supply link for maintaining stable high-temperature combustion. In terms of operating parameters, the air volume ratio (total air) should be controlled at 10-20%, employing an inclined swirling air supply method. This ensures jet penetration while enhancing the intensity of the recirculation zone inside the furnace 10, increasing the flue gas residence time, thereby promoting further oxidation of CO and incompletely combusted products, and reducing the probability of localized high-temperature zones.

[0035] The present invention provides three oxygen supply systems in the upper burnout zone of the furnace 10. The three oxygen supply systems are arranged axially to supply a small amount of oxygen to the mainstream direction of the flue gas, which is used to promote the deep oxidation process of the residual combustible components in the flue gas.

[0036] This three-stage oxygen replenishment utilizes a weakly disturbed axial oxygen supply method to ensure uniform oxygen diffusion along the flue gas flow direction, thereby avoiding disruption to the main flue gas flow field and guaranteeing the flow stability of the burnout zone. This stage is primarily used for the final oxidation and purification of CO, H2, and trace volatile organic compounds. In terms of operating parameters, the air volume ratio (total air) should be controlled at 20-30%, and an axial air supply method should be adopted to avoid the formation of short-circuit flow in the flue gas, while simultaneously improving the oxygen utilization efficiency in the burnout zone, thereby reducing flue gas opacity and fly ash carbon content.

[0037] The aforementioned graded oxygen supply achieves precise oxygen matching and oxygen concentration gradient distribution for different combustion stages. Furthermore, the oxygen supply air for the initial oxygen supply at the bottom of grate 3, the secondary oxygen supply in the middle of furnace 10, and the tertiary oxygen supply in the upper part of furnace 10 is preheated using residual heat from furnace 10 before entering furnace 10, thereby increasing the combustion air temperature and reducing the impact of low-temperature cold air on the furnace 10 temperature.

[0038] S3. Dual Turbulence Enhancement and Disturbance Process: This process involves directional control of the airflow inside the furnace 10, using a combination of airflow swirl and mechanical disturbance to perform dual turbulence disturbance, thereby enhancing the turbulence intensity and gas-solid / gas-gas mixing efficiency inside the furnace 10, and thus strengthening the mass and heat transfer conditions of the combustion reaction process.

[0039] In this process, the secondary oxygen supply vent is designed with an inclined angle to create swirling turbulence in the oxygen supply flow, thereby enhancing the gas-solid two-phase mixing effect. Specifically: The inclined swirl-type oxygen supply vents in the secondary oxygen supply system are evenly distributed around the furnace 10 and installed at an angle relative to the tangential direction of the furnace 10. Based on this, the oxygen supply flow entering the furnace 10 has both axial and tangential velocity components during injection, thereby forming a stable annular swirl structure inside the furnace 10 and enhancing the gas-solid two-phase mixing effect.

[0040] This swirling structure generates strong rotational motion and a backflow effect in the flue gas, disrupting the original laminar boundary and significantly enhancing the turbulence intensity inside the furnace 10. Under the influence of the swirling flow, the contact area between the oxygen jet and the high-temperature combustible flue gas increases dramatically, accelerating the mixing process and shortening the diffusion path, thereby improving oxygen transfer efficiency and combustion reaction rate. Furthermore, the central backflow zone formed by the swirling structure effectively traps some of the high-temperature flue gas and unburned combustible components, prolonging the residence time of the flue gas in the high-temperature reaction zone and promoting further oxidation reactions of CO and volatile organic compounds.

[0041] Mechanical turbulence involves installing a high-temperature resistant turbulence structure in the upper part of the furnace 10 to periodically disturb and impede the flue gas flow, thereby extending the actual residence time of the flue gas in the high-temperature region. Specifically: A wave-shaped high-temperature resistant baffle plate 12 is fixedly installed on the upper inner wall of the furnace 10. The baffle plate 12 is made of heat-resistant steel or silicon carbide composite material and is arranged in layers along the height direction of the furnace 10.

[0042] As the high-temperature flue gas flows upward, the wavy surface continuously changes the flow direction and velocity distribution of the flue gas, generating local vortices and stagnation effects on the backflow side and troughs of the baffle 12. This breaks the original smooth laminar flow state of the flue gas, increases the probability of collision between unburned combustible components and residual oxygen, and prolongs the actual residence time of the flue gas in the high-temperature reaction zone.

[0043] This mechanical turbulence method requires no additional power input and can enhance combustion completeness simply by optimizing the internal flow field structure of the furnace 10. It is especially suitable for the stringent requirements of flue gas burnout under high-altitude and low-oxygen conditions.

[0044] S4. Furnace temperature adaptive control process: Temperature monitoring units are installed in the combustion zone and burnout zone of furnace 10 to collect furnace 10 temperature data in real time, and the oxygen supply air volume and air intake ratio are dynamically adjusted according to the air pressure changes in the low-pressure environment of the plateau to maintain a stable combustion state in the furnace and avoid combustion fluctuations or flameout under low oxygen conditions.

[0045] S5. Flue gas waste heat recovery process: After combustion, the high-temperature flue gas is introduced into the tail flue after being disturbed by turbulence. Part of the high-temperature flue gas is circulated back to step S1. The waste heat of the flue gas is used to dry the pre-treated waste, realizing the cascade utilization of energy. The flue gas is purified and discharged in compliance with standards. The incineration residue is collected and disposed of in a harmless manner.

[0046] like Figure 2 As shown, the present invention also provides a staged oxygen supplementation and turbulence enhancement device for a waste incinerator in a high-altitude low-oxygen environment, including a feeding system, a furnace combustion system, a three-stage stratified oxygen supplementation system, a turbulence enhancement system, a temperature monitoring and control system, and a flue gas purification and waste heat recovery system.

[0047] The feeding system includes a feeding hopper 1, a feeding device 2 and an insulated silo connected in sequence. The feeding hopper 1 and the feeding device 2 are connected to each other and are used to continuously and stably transport the waste to the grate 3 of the furnace combustion system.

[0048] The furnace combustion system includes a grate 3 and a furnace 10. The grate 3 is located at the bottom of the furnace 10. A furnace outlet 14 is located above the furnace 10, and an induced draft fan 15 is connected to the furnace outlet 14. An ash outlet 6 and an ash conveying mechanism are located at the bottom of the furnace 10.

[0049] The three-stage stratified oxygen supply system includes a primary oxygen supply system located below the grate 3, a secondary oxygen supply system located in the lower part of the main combustion zone of the furnace 10, and a tertiary oxygen supply system located in the upper burnout zone of the furnace 10.

[0050] The primary oxygen supply system includes a primary air chamber 4 located below the grate 3, which supplies air to the bottom of the furnace 10 through a primary air nozzle 5.

[0051] The secondary oxygen supply system includes a secondary air nozzle 8 that is inclinedly arranged in the lower part of the furnace 10. The secondary air nozzle 8 is connected to the air supply system through a secondary air duct 9.

[0052] The three-stage oxygen replenishment system includes a three-stage air nozzle 11 located at the top of the furnace 10 for replenishing oxygen to the flue gas combustion zone; a wave-shaped high-temperature resistant baffle 12 is fixedly installed on the upper inner wall of the furnace 10 to enhance flue gas turbulence.

[0053] The turbulence enhancement system includes an airflow swirl structure and a mechanical turbulence structure. The airflow swirl structure is a secondary air nozzle 8 installed at an angle and tangentially. The mechanical turbulence structure is a wave-shaped high-temperature resistant baffle plate 12 fixed in layers to the upper inner wall of the furnace 10. The high-temperature resistant baffle plate 12 is made of heat-resistant steel or silicon carbide composite material.

[0054] The temperature monitoring and control system includes several temperature sensors 13 installed in the combustion zone and burnout zone of the furnace 10 for real-time monitoring of the temperature inside the furnace 10.

[0055] The flue gas purification and waste heat recovery system includes a waste heat boiler 16, a bag filter 17, a desulfurization and denitrification mechanism 18, and a chimney 19, which are connected in sequence to the secondary air duct 9.

[0056] In application, high-altitude domestic waste first enters the feeding device 2 through the feed hopper 1, and is continuously conveyed to the grate 3 for combustion. Before entering the furnace 10, the waste can be screened, crushed, and pre-dried to improve the combustion stability of the waste and reduce the impact of high-moisture waste on the furnace temperature.

[0057] During combustion, the primary air chamber 4 supplies air to the bottom of the grate 3 through the primary air nozzle 5, providing oxygen for waste drying and the initial combustion stage. Due to the low air pressure and insufficient oxygen content in plateau areas, this invention adopts a multi-stage layered oxygen supplementation method. A secondary air nozzle 8 is set in the lower part of the furnace 10, and swirling air is injected into the furnace through the secondary air duct 9 to enhance the oxygen supply and airflow disturbance effect in the main combustion zone. At the same time, a tertiary air nozzle 11 is set in the upper part of the furnace 10 to supplement oxygen to the flue gas burnout zone, so as to promote the further combustion of the residual combustible components in the flue gas and improve the burnout effect.

[0058] In this embodiment of the invention, the secondary air nozzle 8 is inclined, causing the air entering the furnace 10 to form a swirling structure, enhancing the mixing effect between oxygen and combustible flue gas and improving the traditional laminar combustion state. At the same time, the baffle 12 set at the upper part of the furnace 10 blocks and guides the high-temperature flue gas, forcing the flue gas to change its flow direction, thereby prolonging the residence time of the flue gas in the high-temperature region and improving combustion stability and pollutant decomposition effect.

[0059] To adapt to the low-oxygen and low-temperature environment of high altitudes, this invention installs a temperature sensor 13 inside the furnace 10 to monitor the temperature changes of the furnace 10 in real time and dynamically adjust the oxygen supply volume and air supply intensity at each stage based on the detection results. When the ambient air pressure changes or the calorific value of the waste fluctuates, the system can automatically adjust the oxygen supply status to maintain stable combustion in the furnace 10 and avoid low-temperature flameout or incomplete combustion.

[0060] The high-temperature flue gas after combustion is discharged from the furnace outlet 14 and enters the waste heat boiler 16 / heat exchanger under the action of the induced draft fan 15. The waste heat of the flue gas can be used for waste pretreatment or oxygen supplementation air preheating to achieve heat energy recovery and utilization. Subsequently, the flue gas enters the bag filter 17 for particulate matter removal, and then enters the desulfurization and denitrification unit 18 for pollutant purification treatment, and is finally discharged from the chimney 19.

[0061] The ash produced after combustion is discharged through ash outlet 6 and then collected and treated in a centralized manner by ash conveying mechanism 7.

[0062] The waste incinerator provided in this invention, through a combination of multi-stage layered oxygen supplementation and turbulence enhancement structure, can effectively improve problems such as uneven oxygen distribution, unstable combustion, and insufficient flue gas disturbance during waste incineration in high-altitude low-oxygen environments, thereby improving the stability and burnout effect of waste combustion and reducing pollutant emissions and system operating energy consumption.

[0063] Example 1: In this embodiment, the method and apparatus of the present invention are applied to a small-scale municipal solid waste incineration plant in a town on the Qinghai-Tibet Plateau. After screening and crushing, the municipal solid waste enters the grate 3 through the feed hopper 1 for combustion. Primary air nozzles 5 supply air to the bottom of the grate 3, secondary air nozzles 8 create a swirling flow for oxygen supplementation, and tertiary air nozzles 11 supplement oxygen to the burnout zone. Baffles 12 are installed inside the furnace 10 to enhance flue gas turbulence, and temperature sensors 13 monitor furnace temperature changes in real time. The flue gas after combustion is purified sequentially through a waste heat boiler 16 / heat exchanger, a bag filter 17, and a desulfurization and denitrification unit 18 before being discharged. This embodiment can effectively adapt to the low-pressure, low-oxygen environment of the plateau, improving the stability of waste combustion and the flue gas purification effect.

[0064] Therefore, the present invention adopts the above-mentioned method and device for staged oxygen supplementation and turbulence enhancement in a waste incinerator under high-altitude low-oxygen environment. By optimizing the flow field and oxygen concentration distribution in the furnace through multi-structure synergy, it solves the problems of incomplete combustion, unstable furnace temperature and high energy consumption in traditional incineration processes. It has the advantages of low transformation cost and outstanding environmental benefits, and has high engineering promotion value.

[0065] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the technical solutions of the present invention, and these modifications or equivalent substitutions cannot cause the modified technical solutions to deviate from the spirit and scope of the technical solutions of the present invention.

Claims

1. A method for staged oxygen supplementation and turbulence enhancement in a waste incinerator under high-altitude low-oxygen conditions, characterized in that, Includes the following steps: S1. Collect domestic waste from highland towns and carry out waste classification and pretreatment; S2. A layered oxygen supply mode is adopted, which includes one oxygen supply at the bottom of the grate, two oxygen supplies in the middle of the furnace, and three oxygen supplies in the upper part of the furnace. The oxygen supply parameters are dynamically adapted and adjusted according to the low air pressure environment of the plateau. S3. A combination of airflow swirl and mechanical turbulence is used to create dual turbulent disturbances, thereby enhancing the turbulent field inside the furnace. S4. Temperature monitoring units are installed in the combustion zone and burnout zone of the furnace to collect furnace temperature data in real time, and the oxygen supply air volume and air intake ratio are dynamically adjusted according to the air pressure changes in the low-pressure environment of the plateau. S5. After combustion, the high-temperature flue gas is introduced into the tail flue after being disturbed by turbulence. Part of the high-temperature flue gas is circulated back to step S1, and the waste heat of the flue gas is used to dry the pre-treated waste. After purification, the flue gas is discharged in compliance with standards, and the incineration residue is collected and disposed of in a harmless manner.

2. The method for staged oxygen supplementation and turbulence enhancement in a waste incinerator under high-altitude low-oxygen conditions according to claim 1, characterized in that, S1 includes the following steps: S11. Collect domestic waste from highland towns and classify it using a drum screener; separate and remove non-combustible impurities, including stones, metals, and glass; the undersize material then enters a twin-shaft shear crusher for crushing. S12. For the high-moisture components of kitchen waste in plateau urban waste, a pre-drying treatment using furnace waste heat recovery is adopted to reduce the moisture content of the waste to a range suitable for stable combustion. Specifically: High-temperature flue gas drawn from the tail flue of the incinerator is sent into a closed drying drum after being cyclone dust collector, where it is dried with waste with high moisture content. Inside the drying drum, the material is constantly turned over and evenly dispersed by the lifting plate structure, so that it is fully heated and the heat and mass transfer process is enhanced. After treatment, the moisture content of the waste is controlled to below 35%. S13. A low-temperature slow drying strategy is adopted to control the inlet temperature of hot flue gas below 200℃ to avoid the formation of a hard shell structure on the surface of the material due to instantaneous dehydration. The dried waste is temporarily stored in an insulated silo to reduce direct contact with the outside low-temperature air and inhibit moisture reabsorption and heat loss.

3. The method for staged oxygen supplementation and turbulence enhancement in a waste incinerator under high-altitude low-oxygen conditions according to claim 2, characterized in that, S2 specifically refers to: The primary oxygen supply system located below the grate provides oxygen to the bottom of the grate. The primary oxygen supply system adopts a distributed air supply structure that is evenly arranged along the transverse and longitudinal directions of the grate to provide the oxygen required for initial combustion and drying to the waste layer. Secondary oxygen supply is carried out in the main combustion zone in the middle of the furnace through a secondary oxygen supply system. The secondary oxygen supply system uses multiple sets of inclined swirl-type oxygen supply vents evenly arranged along the circumference of the furnace to provide the air required for enhanced oxidation to the main combustion zone. The upper part of the furnace is oxygenated three times by a three-stage oxygen supply system located in the burnout zone. The three-stage oxygen supply system is arranged axially to supplement a small amount of oxygen in the mainstream direction of the flue gas, which is used to promote the deep oxidation process of the residual combustible components in the flue gas.

4. The method for staged oxygen supplementation and turbulence enhancement in a waste incinerator under high-altitude low-oxygen conditions according to claim 3, characterized in that, The graded oxygen replenishment process adopts a layered oxygen supply mode of one oxygen replenishment at the bottom of the grate, two oxygen replenishments in the middle of the furnace, and three oxygen replenishments in the upper part of the furnace. The oxygen supply parameters are dynamically adjusted according to the real-time monitored ambient atmospheric pressure. in: The primary oxygen supply is delivered through the primary air chamber below the grate, with the air volume accounting for 50-70% of the total volume. The air is delivered evenly and stably to provide the oxygen required for the main combustion zone of the waste layer and to penetrate the material layer. Secondary oxygen supply is injected from the front and rear walls or side walls in the middle of the furnace, with the air volume ratio controlled at 10-20%. The inclined swirl air supply is used to enhance the mixing turbulence of volatiles and oxygen. Three oxygen supplements are provided, supplied from the upper part of the furnace or the burnout zone, with the air volume ratio controlled at 20-30%. The air supply is arranged axially to oxidize the residual CO, H2 and volatile organic compounds in the burnout flue gas.

5. The method for staged oxygen supplementation and turbulence enhancement in a waste incinerator under high-altitude low-oxygen conditions according to claim 4, characterized in that, In S3, the airflow swirl is specifically as follows: The inclined swirl oxygen supply nozzles in the secondary oxygen supply system are evenly distributed along the circumference of the furnace and installed at an angle relative to the tangential direction of the furnace. This allows the oxygen supply flow entering the furnace to have both axial and tangential velocity components during injection, forming a stable annular swirl structure inside the furnace and enhancing the gas-solid two-phase mixing effect. This swirling structure generates strong rotational motion and backflow effect in the flue gas, enhancing the turbulence intensity inside the furnace. At the same time, the central backflow zone formed by the swirling structure is used to intercept some of the high-temperature flue gas and unburned combustible components, prolonging the residence time of the flue gas in the high-temperature reaction zone and strengthening the reaction process.

6. The method for staged oxygen supplementation and turbulence enhancement in a waste incinerator under high-altitude low-oxygen conditions according to claim 5, characterized in that, In S3, the mechanical turbulence specifically refers to: A wave-shaped high-temperature resistant baffle plate is fixedly installed on the upper inner wall of the furnace. The baffle plate is made of heat-resistant steel or silicon carbide composite material and is arranged in layers along the height of the furnace. As the high-temperature flue gas flows upward, the wavy surface continuously changes the flow direction and velocity distribution of the flue gas, generating local vortices and stagnation effects on the back flow side of the baffle and at the troughs. This increases the probability of collision between unburned combustible components and residual oxygen, and prolongs the actual residence time of the flue gas in the high-temperature reaction zone.

7. The method for staged oxygen supplementation and turbulence enhancement in a waste incinerator under high-altitude low-oxygen conditions according to claim 6, characterized in that, The oxygen-supplementing air for the first oxygen supply at the bottom of the grate, the second oxygen supply in the middle of the furnace, and the third oxygen supply in the upper part of the furnace is preheated using the residual heat of the furnace before entering the furnace.

8. A staged oxygen supply and turbulence enhancement device for a waste incinerator in a high-altitude, low-oxygen environment, used to implement the method described in any one of claims 1-7, characterized in that, It includes a feeding system, a furnace combustion system, a three-stage stratified oxygen supplementation system, a turbulence enhancement system, a temperature monitoring and control system, and a flue gas purification and waste heat recovery system; The feeding system includes a feeding hopper, a feeding device and an insulated silo connected in sequence, used to continuously and stably transport waste to the furnace combustion system; The furnace combustion system includes a grate and a furnace. The grate is located at the bottom of the furnace, and a furnace outlet is located above the furnace. An induced draft fan is connected to the furnace outlet. An ash outlet and an ash conveying mechanism are located at the bottom of the furnace. The three-stage stratified oxygen supply system includes a primary oxygen supply system located below the grate, a secondary oxygen supply system located in the lower part of the main combustion zone of the furnace, and a tertiary oxygen supply system located in the upper part of the burnout zone of the furnace. The turbulence enhancement system includes an airflow swirl structure and a mechanical turbulence structure. The airflow swirl structure is a secondary air nozzle installed at an inclined tangential angle, and the mechanical turbulence structure is a wave-shaped high-temperature resistant turbulence plate fixed in layers to the upper inner wall of the furnace. The temperature monitoring and control system includes several temperature sensors installed in the combustion zone and burnout zone of the furnace for real-time monitoring of the temperature inside the furnace. The flue gas purification and waste heat recovery system includes a waste heat boiler, a bag filter, a desulfurization and denitrification mechanism, and a chimney, which are connected in sequence to the secondary air duct.

9. The staged oxygen supply and turbulence enhancement device for a waste incinerator in a high-altitude low-oxygen environment according to claim 8, characterized in that, The primary oxygen supply system includes a primary air chamber located below the grate, which supplies air to the bottom of the furnace through primary air nozzles; The secondary oxygen supply system includes a secondary air nozzle located in the lower part of the furnace, and the secondary air nozzle is connected to the air supply system through a secondary air duct. The three-stage oxygen replenishment system includes a tertiary air nozzle located at the top of the furnace for replenishing oxygen to the flue gas combustion zone; the secondary air nozzle is inclined, and a wave-shaped high-temperature resistant baffle is fixedly installed on the upper inner wall of the furnace.

10. The staged oxygen supply and turbulence enhancement device for a waste incinerator in a high-altitude low-oxygen environment according to claim 8, characterized in that, The high-temperature resistant baffle is made of heat-resistant steel or silicon carbide composite material.

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