CN115200024A - A low-nitrogen, oxygen-enriched, high-efficiency and clean waste incineration system and method - Google Patents

Abstract

The invention discloses a low-nitrogen oxygen-enriched high-efficiency clean waste incineration system and method, which comprises pressure swing adsorption of O ₂ Separator, smoke-steam heat exchanger, incinerator, exhaust-heat boiler, semi-dry reaction tower and bag-type dust remover, and the whole combustion processIs divided into three stages of 'anaerobic drying/pyrolysis', 'solid phase product air combustion' and 'gas phase product oxygen-enriched burnout', and the flue gas is separated and then used for O ₂ Introducing secondary air to perform oxygen-enriched combustion and CO ₂ Adding primary air to react and fully utilize. The invention ensures the stable operation of the pyrolysis stage and fully utilizes the moisture/CO ₂ Reacts with carbon in the garbage to generate a large amount of reducing gas to fully realize CO ₂ The formation of reducing atmosphere is promoted, and the generation amount of NOx in the combustion process is effectively reduced; o after pressure swing adsorption ₂ The full use realizes the segmentation and arranges, has strengthened the mixture with burning the flue gas, guarantees gaseous phase abundant burning, and oxygen boosting high temperature melting has effectively solved the problem of burning furnace throat coking.

Description

A low-nitrogen, oxygen-rich, high-efficiency and clean waste incineration system and method

technical field

The invention relates to a low-nitrogen, oxygen-enriched, high-efficiency and clean waste incineration system and method, and belongs to the technical field of environmental protection.

Background technique

_NOx can form photochemical smog, which threatens human health and life. The country has stricter and stricter requirements for flue gas pollutant emissions, and the denitration process is becoming more and more complicated. The SCR process is used for denitrification. The waste catalyst needs to be treated as hazardous waste, and the cost is getting higher and higher . Under the current dual-carbon policy, power plants urgently need to reduce operating costs and reduce power consumption and CO ₂ emissions. Therefore, it is urgent to develop an efficient and clean process scheme to control NOx generation and flue gas volume from the source.

The patent publication number CN113464950A extracts 220 ℃ ~ 350 ℃ flue gas from the side or upper part of the waste heat boiler in the economizer section and returns it to the furnace for recycling, which contains a large amount of dust, heavy metals and other substances, which are easy to corrode the flue, and at the same time the primary air flue gas itself Containing O ₂ , it needs to be mixed with air and air in three stages, resulting in a large amount of oxygen doped in the drying and ignition units, which is not conducive to the generation of reducing gas. The first two stages of air distribution in this patent are carried out by oxygen-free gas heat carrier Drying and pyrolysis ensure a high reducing atmosphere. Due to the absence of oxygen, CO ₂ will further react with carbon in the garbage, promoting the generation of more pyrolysis gas and reducing NOx to the greatest extent.

The patent with publication number CN112781049A discloses a domestic waste incinerator and a combustion method using composite high-efficiency and low-NOx combustion. A plurality of primary air nozzles (11) and recirculating flue gas jet nozzles are mainly opened in the furnace chamber. There is a recirculation nozzle at the end of the furnace to promote the mixing of gas products to reduce NOx. It is completely different from this patent. The primary air position of this patent is passed into the flue gas without O ₂ , which greatly ensures that the reducing gas fills the entire incinerator. The secondary air adopts the method of oxygen-enriched air arrangement, which reduces the amount of flue gas and reduces the concentration of NOx and CO ₂ at the same time.

The patent publication number CN112503535A extends the flue gas at the tail of the induced draft fan to the throat of the incinerator, and the recirculated flue gas is introduced into the incinerator as secondary air, and the exhausted air pipeline is located between the recirculated flue gas pipeline and the incinerator. Above the connection point of , does not involve the regulation of primary air, and at the same time dilutes the secondary air, which may easily lead to excessive CO. This patent uses oxygen-enriched air at the outlet of the incinerator, which not only reduces the amount of flue gas during combustion, but also ensures that the gas phase products are fully burned out.

SUMMARY OF THE INVENTION

The technical problem to be solved by the present invention is that the traditional waste incineration system has a large primary air distribution ratio, which leads to high NOx generation, and at the same time, due to the inherent characteristics of the grate furnace, the carbon content of the ash often exceeds the standard, and the burnout rate of the waste cannot meet the requirements. standard. The CO ₂ in the generated flue gas is also not utilized. As a result, the cost of flue gas treatment is high, and the economic benefit of the power plant is not high, but a low-nitrogen, oxygen-rich, high-efficiency and clean waste incineration system and method are provided.

In order to solve the above-mentioned technical problems, the technical scheme adopted in the present invention is:

A low-nitrogen, oxygen-enriched, high _- efficiency and clean waste incineration system, including a pressure swing adsorption O separator, a flue gas fan, a flue gas vapor heat exchanger, an incinerator, a waste heat boiler, a semi-dry reaction tower, a bag filter, and an induced draft fan , chimney, oxygen-enriched fan, oxygen-enriched pipeline, oxygen-enriched air inlet pipeline;

Pressure swing adsorption O ₂ separator, flue gas fan, flue gas vapor heat exchanger, incinerator, waste heat boiler, semi-dry reaction tower, bag filter, and induced draft fan are connected in sequence by pipeline;

The induced draft fan and the pressure swing adsorption O ₂ separator are respectively connected to the chimney by pipes;

The pressure swing adsorption O ₂ separator is connected to the incinerator through an oxygen-enriched pipeline, one end of the oxygen-enriched air inlet pipeline is connected to the oxygen-enriched pipeline, and the other end is connected to the incineration room of the waste heat boiler, and air is drawn from the incineration room for use. It is mixed with pure oxygen, equipped with oxygen-enriched air with a certain concentration, and the oxygen-enriched fan is installed on the oxygen-enriched pipeline.

As a further preferred solution, the incinerator includes a furnace body, an oxygen-free flue gas distribution pipeline, a primary air pipeline, and an oxygen-enriched supplementary air distribution pipeline, and the furnace body includes a side feeding port and an upper part. The flue gas outlet is connected to the waste heat boiler. The bottom of the furnace body has an inclined surface. The inclined surface is respectively provided with five units from top to bottom, namely the first unit, the second unit, the third unit and the fourth unit. , the fifth unit, and each unit corresponds to an air duct, which are the first section, the second section, the third section, the fourth section, and the fifth section, each air duct has a fan, the oxygen-free smoke One end of the gas distribution pipeline is connected to the flue gas vapor heat exchanger, and the other end is connected to the first, second, and third sections respectively, and the primary air pipeline is connected to the third, fourth, and third sections respectively. In the fifth stage, one end of the oxygen-enriched supplementary air distribution pipeline is connected to the oxygen-enriched pipeline, and the other end is connected to the flue gas outlet.

As a further preferred solution, there is an oxygen-enriched air upper road inlet and an oxygen-enriched air lower road inlet at the flue gas outlet, and the oxygen-enriched supplementary air distribution pipeline is respectively connected to the oxygen-enriched air upper road inlet and the oxygen-enriched air lower road inlet, The air volume ratio of the upper entrance of the oxygen-enriched air and the entrance of the lower oxygen-enriched air is 3:7.

As a further preferred solution, the O ₂ concentration in the oxygen-enriched pipeline is above 95%.

As a further preferred solution, the temperature of the flue gas entering the incinerator from the flue gas vapor heat exchanger is 250°C.

An incineration method for a low-nitrogen, oxygen-enriched, high-efficiency and clean waste incineration system, comprising the following steps:

Step 1: Part of the flue gas in the chimney is drawn through the oxygen-enriched fan to enter the pressure swing adsorption O ₂ separator to separate O ₂ from the oxygen-free flue gas. The remaining substances in the oxygen-free flue gas are mainly N ₂ CO ₂ and H ₂ O;

Step 2: After the oxygen-free flue gas is sucked by the flue gas fan, it is heated from 120 ℃ to 250 ℃ through the flue gas steam heat exchanger;

Step 3: The heated anaerobic flue gas enters the first and second sections of the incinerator to ensure drying and partial pyrolysis under anaerobic conditions;

Step 4: The third unit is fed with air and a small amount of oxygen-free flue gas according to the traditional waste incineration method, and the air passage coefficient is controlled to be 0.3 to 0.5, so that partial combustion and pyrolysis occur, and the radiant heat is transferred to the waste gas. The second unit ensures that at the same time the pyrolysis process occurs in the second unit, its high concentration of CO ₂ reacts with C in the garbage, and the reaction formula is as follows:

C+CO ₂ =2CO

C+H ₂ O=CO+H ₂

Further, not only the reducing gas contained in the pyrolysis itself, but also a large amount of reducing gas is further generated through CO ₂ and H ₂ O;

Step 5: A sufficient amount of air is introduced into the fourth unit, and the excess air coefficient is about 1.1. In addition, a part of the fifth unit enters the "solid product air combustion" stage and is fully burned, producing a large amount of NO, which is produced with the second and third units. The reducing gas reacts in the incineration furnace to reduce NOx and consume a large amount of _CO2 ;

Step 6: The gas that has interacted contains some unburned components, and the "oxygen-enriched combustion stage" is fully burned in the upper part of the incinerator. The oxygen separated by the pressure swing adsorption O ₂ separator is sucked by the oxygen-enriched fan and divided into Two paths are sprayed into the upper part of the incinerator, and the ratio of the upper path is 10% to 30%, and the rate of the lower path is 90% to 70%; according to the indicators of pollutants in the flue gas, the valve opening of the oxygen-enriched air inlet pipe is appropriately opened, and the supply from the incineration room is replenished. The right amount of air is still guaranteed to be oxygen-enriched combustion (oxygen concentration is greater than 30%); while the unburned gas is fully burned, the gas phase combustion increases the temperature of the throat, which largely inhibits the coking of the throat of the waste incinerator phenomenon, while further ensuring the emission of dioxins up to the standard.

Compared with the prior art, the present invention can suppress the generation of _NOx in the flue gas from the source, reduce _CO2 emissions while meeting the emission standard, improve the thermal efficiency of power plant boilers, and reduce the process route of flue gas volume, and has the following advantages. .

(1) The introduction of oxygen-free flue gas in the first and second stages of the incinerator enhances the waste drying process, ensures the stable progress of the pyrolysis stage, and makes full use of the reaction of moisture and _CO to generate a large amount of reducing gas, Fully realize the recycling of CO2 and the formation of a reducing atmosphere, effectively reducing the amount of NOx generated during the combustion process; the mixing of the third section of flue gas and air at the grate position not only provides part of the heat for the pyrolysis of waste, but also provides heat for waste pyrolysis. The stable combustion of the fourth unit provides a guarantee, realizes efficient and clean combustion, and is conducive to the C content in the ash and slag reaching the standard.

(2) The _O2 after pressure swing adsorption is fully utilized to realize segmented arrangement, strengthen the mixing with incineration flue gas, and ensure full gas phase combustion. The flue gas volume of the entire incineration system is reduced, the power consumption of the induced draft fan and the concentration of pollutants are reduced, and the incineration of waste is low-carbon, energy-efficient, efficient and clean.

Description of drawings

Fig. 1 is the flow chart of the waste incineration low-carbon and low-nitrogen system of the present invention;

Figure 2 is a flow chart of the air distribution system of the waste incinerator.

Detailed ways

The preferred technical solutions of the present invention will be described in detail below with reference to the accompanying drawings.

In the traditional waste incineration system, the primary air distribution ratio is large, and the excess air system is between 1.6 and 1.8, which leads to high NOx generation. At the same time, the inherent characteristics of the grate furnace cause the carbon content of the ash to exceed the standard frequently, and the burnout rate of the waste. Can't meet the standard. The CO ₂ in the generated flue gas is also not utilized. As a result, the cost of flue gas treatment is high, and the economic benefits of the power plant are not high. Especially after the release of the dual-carbon target, and the biomass power plant will no longer enjoy the national subsidy after 82,500 hours of operation or 15 years, the waste incineration power plant energy saving and emission reduction is also imminent.

The conventional waste incineration process is that after the waste enters the furnace, after the primary air incineration and the secondary air are burned out, the flue gas enters the waste heat boiler through the first and second flues, and after absorbing the heat, it enters the semi-dry reaction tower for deacidification. After the dust is removed by the bag filter, it is evacuated by the induced draft fan. The combustion process will produce a high concentration of NOx, the pollution is more serious.

The principle of this patented process is to firstly control the reaction atmosphere in different areas of the grate, and divide the waste combustion process into three stages: "anaerobic drying/pyrolysis", "air combustion of solid phase products" and "oxygen-enriched burnout of gas phase products" . The invention provides a high-efficiency, clean, low-carbon and low-nitrogen system for a waste incineration power plant. The process principle is as follows: the waste with high water content is first subjected to anaerobic drying/pyrolysis to generate semi-coke with low or no water and reducing volatiles (including water steam, tar, pyrolysis gas, etc.); garbage semi-coke has good flammability, after it is mixed with the flue gas generated by primary air combustion and pyrolysis volatiles, the NOx contained in the flue gas is replaced by the tar, volatile matter in the volatile matter. The reducing components such as H ₂ and CO are reduced to N ₂ , thereby reducing the initial NO _x generation in the combustion process; the unburned volatiles are then contacted with the secondary oxygen-enriched air for complete combustion.

A low-nitrogen, oxygen-enriched, high-efficiency and clean waste incineration system of the present invention includes a pressure swing adsorption O ₂ separator 10, a flue gas vapor heat exchanger 9, an incinerator 11, a waste heat boiler 12, a semi-dry reaction tower 13, and a bag dust collector. 14, chimney 16, oxygen-enriched pipe 17, oxygen-enriched air inlet pipe 5;

As shown in Figure 1, the pressure swing adsorption O ₂ separator 10, the flue gas fan 3, the flue gas steam heat exchanger 9, the incinerator 11, the waste heat boiler 12, the semi-dry reaction tower 13, the bag filter 14, the induced draft fan 15 The pipes are connected in sequence, wherein the flue gas steam heat exchanger 9 is connected to the incinerator 11 through the oxygen-free flue gas inlet pipe 6;

The induced draft fan 15 is piped to the chimney 16, and the pressure swing adsorption O ₂ separator 10 is connected to the flue gas taking port 1 of the chimney 16 through the flue gas pipe 2;

The pressure swing adsorption O ₂ separator 10 is connected to the upper part of the incinerator 11 through an oxygen-enriched pipe 17 , one end of the oxygen-enriched air inlet pipe 5 is connected to the oxygen-enriched pipe 17 , and the oxygen-enriched fan 4 is installed on the oxygen-enriched pipe 17 .

The incinerator 11 includes a furnace body 18, an oxygen-free flue gas distribution pipeline 19, a primary air pipeline 20, and an oxygen-enriched supplementary air distribution pipeline 21. The furnace body 18 includes a side feed port 22 and an upper flue gas pipeline. The outlet 23, the flue gas outlet 23 is connected to the flue and enters the waste heat boiler 12. The bottom of the furnace body 18 has an inclined surface. The inclined surface is respectively provided with five air pipes from top to bottom, which are the first section, the second section and the first section. The third section, the fourth section and the fifth section have a fan on each air duct. One end of the oxygen-free flue gas distribution pipeline 19 is connected to the flue gas vapor heat exchanger 9, and the other end is connected to the first section and the second section respectively. In the second and third sections, the primary air pipeline 20 is connected to the third, fourth and fifth sections respectively. One end of the oxygen-enriched supplementary air distribution pipeline 21 is connected to the oxygen-enriched pipeline 17, and the other end is connected to the 23 flue gas outlets (throat of the incinerator).

Specifically, the flue gas outlet 23 (throat of the incinerator) has an oxygen-enriched air upper inlet 8 and an oxygen-enriched air lower inlet 7, and the oxygen-enriched supplementary air distribution pipeline 21 is respectively connected to the oxygen-enriched upper inlet 8 and the oxygen-enriched air inlet 7. Oxygen-enriched air lower road inlet 7, oxygen-enriched air upper road inlet 8 and oxygen-enriched air lower road inlet 7; wherein, a flue gas fan 3 is installed on the oxygen-free flue gas distribution pipeline 19 for discharging the oxygen-free flue gas into incineration The furnace 11, and the anaerobic flue gas distribution pipeline 19 is equipped with a flue gas steam heat exchanger 9. The temperature of the anaerobic flue gas is generally about 130°C. The oxygen-free flue gas enters the incinerator and can be fully dried and pyrolyzed. The primary air pipeline 20 is equipped with a primary air-air preheater 24. The primary air-air preheater 24 mainly heats the air to ensure that the third, fourth and fifth sections are heated. , the solid phase product can be fully combusted to ensure the stable working condition of the incinerator and the compliance of the waste burnout rate. The oxygen-enriched air distribution pipeline 21 is equipped with an oxygen-enriched fan 4 .

The concentration of O ₂ separated into the oxygen-enriched pipeline 17 by the pressure swing adsorption O ₂ separator 10 is above 95%.

The temperature of the flue gas entering the incinerator 11 after being heated by the flue gas vapor heat exchanger 9 is 250°C.

The traditional primary air distribution system is composed of a flue gas steam heat exchanger, a primary air fan and a primary air distribution pipeline. The primary air is distributed in five sections through ①-⑤ induced draft fans to provide oxygen for waste incineration. In the incinerator of the patent of the present invention, the first stage is anaerobic drying, and the second stage is partially anaerobic pyrolysis, which ensures that the excess air coefficient of the two stages is basically 0, and greatly improves the generation of pyrolysis gas. The third stage adopts the mode of mixing air and anaerobic flue gas, which can not only ensure the temperature of the entire pyrolysis stage, but also provide a large amount of radiant heat for the second stage of garbage to ensure the complete pyrolysis process. It is ensured that after the semi-coke after pyrolysis enters the fourth stage, it can ignite normally and enter complete combustion, and the fifth stage burns out, which further ensures the burning of the residual carbon. Since some carbon and oxygen-free flue gas also react in the first three stages, the amount of air required in the fourth and fifth stages is less than that of traditional combustion, and the entire combustion process can also be guaranteed. A large amount of pyrolysis gas and tar and other substances are produced through the oxygen-free flue gas. After the flue gas burned in the fourth and fifth stages is mixed, part of the NOx is reduced, and then completely burned through the oxygen-enriched supplementary air system. The oxygen-enriched air supply system is divided into upper and lower channels. By adjusting the proportion of the air distribution between the two channels, the gas is burned out and the flue gas pollutants are further reduced. The air volume ratio of the upper and lower channels is preferably 3:7. Through the disturbance of the large air volume in the lower channel, it not only ensures sufficient combustion, but also further promotes the interaction between reducing gases (CO, NH _i and CN, etc.) and NOx, and reduces its generation at the source. . The high temperature generated by the combustion of the oxygen-enriched gas can melt the coke at the throat, which can effectively solve the coking problem at the throat of the waste incinerator, reduce the number of shutdowns, prolong the operation time of waste incineration, and improve economic benefits. At the same time, oxygen-enriched combustion is adopted, and the overall amount of air used is much less than that of traditional combustion, so the amount of flue gas is reduced by 15% to 30% compared with traditional combustion, the frequency and power consumption of induced draft fans are reduced, and NOx generation is reduced by 35%. ～60%, the total CO ₂ emissions are reduced by 10% to 15%, and the incineration of low-carbon, energy-saving, efficient and clean waste is realized.

The present invention is a low-nitrogen, oxygen-enriched, high-efficiency and clean incineration method for a waste incineration system, characterized in that it comprises the following steps:

Step 1: by extracting a part of the flue gas in the chimney 16 and entering the pressure swing adsorption O ₂ separator 10, the O ₂ and the oxygen-free flue gas are separated;

Step 2: After the oxygen-free flue gas is drawn by the flue gas fan 3, it is heated from 120°C to 250°C through the flue gas vapor heat exchanger 9;

Step 3: The heated anaerobic flue gas enters the first and second sections of the incinerator 11 to ensure drying and partial pyrolysis under anaerobic conditions;

Step 4: The third unit is fed with air and a small amount of oxygen-free flue gas according to the traditional waste incineration method, and the air passage coefficient is controlled to be 0.3 to 0.5, so that partial combustion and pyrolysis occur, and the radiant heat is transferred to the waste gas. The second unit ensures that at the same time the pyrolysis process occurs in the second unit, its high concentration of CO ₂ reacts with C in the garbage, and the reaction formula is as follows:

C+CO ₂ =2CO

C+H ₂ O=CO+H ₂

Further, not only the reducing gas contained in the pyrolysis itself, but also a large amount of reducing gas is further generated through CO ₂ and H ₂ O;

Step 5: A sufficient amount of air is introduced into the fourth unit, and the excess air coefficient is about 1.1. In addition, a part of the fifth unit enters the "solid product air combustion" stage and is fully burned, producing a large amount of NO, which is produced with the second and third units. The reducing gas reacts in the incineration furnace to reduce NOx and consume a large amount of _CO2 ;

Step 6: The gas that has interacted contains some unburned components, and the "oxygen-enriched combustion stage" is fully burned in the upper part of the incinerator 11, and the oxygen separated by the pressure swing adsorption O ₂ separator 10 is pumped through the oxygen-enriched fan 4. Inhalation, spray into the upper part of the incinerator 11 in two ways, the proportion of the upper route is 10% to 30%, and the proportion of the lower route is 90% to 70%; according to the indicators of pollutants in the flue gas, the valve opening of the oxygen-enriched air inlet duct 5 is appropriately opened. , Supplement an appropriate amount of air from the incineration room, and still ensure oxygen-enriched combustion; while fully burning the unburned gas, due to the gas phase combustion, the temperature of the throat is increased, which largely inhibits the phenomenon of coking in the throat of the waste incinerator , while further ensuring the emission of dioxins up to standard.

Example 1

Using this design idea, for a 300t/d waste incinerator, the flue gas volume is 50000Nm ³ /h, and the initial NOx emission value is 350mg/Nm ³ . After the process transformation of this patent is implemented, 10000Nm ³ /h of flue gas is extracted from the tail of the induced draft fan and enters the pressure swing adsorption oxygen separator. The first and second units of the primary air are fed with oxygen-free flue gas, and the air volume of the third unit is reduced by 60%. , the fourth and fifth paragraphs remain unchanged. In the gas-phase oxygen-enriched combustion stage, the ratio of lower air to upper air is 7:3, and the oxygen concentration is 45%. The initial value of NOx is 140-190 mg/Nm ³ , the average value is 160 mg/Nm ³ , and the denitration efficiency is as high as 54%. The flue gas volume is reduced to 42,000Nm ³ /h, the power consumption of the induced draft fan is reduced by 16%, and the annual operating cost is saved by 670,000 yuan.

Example 2

Using this design idea, for a 600t/d waste incinerator, the flue gas volume is 120000Nm3/h, and the initial NOx emission value is 320mg/Nm3. After the process transformation of this patent is implemented, 30000Nm3/h of flue gas is extracted from the tail of the induced draft fan and enters the pressure swing adsorption oxygen separator. Air, the air volume is reduced to 50% of the original, and the fourth and fifth stages remain unchanged. In the gas phase oxygen-enriched combustion stage, the ratio of the lower air to the upper air is 8:2, and the oxygen concentration is 40%. The initial value of NOx was 132-195 mg/Nm ³ , the average value was 172 mg/Nm ³ , and the denitration efficiency was as high as 46.25%. The flue gas volume is reduced to 105000Nm ³ /h, the power consumption of the induced draft fan is reduced by about 18%, the economic benefits are obvious, and the annual operating cost is saved by 1.35 million yuan.

The present invention adopts a low-nitrogen, low-carbon, and oxygen-enriched process design method, and the entire combustion process is divided into three stages: "oxygen-free drying/pyrolysis", "air combustion of solid-phase products" and "oxygen-enriched burnout of gas-phase products". In the second and third stages, through drying and pyrolysis, volatilization analysis shows that in the fourth stage only solid semi-coke is burned, and the incomplete combustion is further burned in the fifth stage _; The secondary air is used for oxygen-enriched combustion and CO ₂ is added to the primary air to make full use of it. The anaerobic flue gas is used for drying and pyrolysis of the garbage. The primary air combustion is placed in the fourth and fifth units. The oxygen-enriched combustion method in which pure oxygen and air are mixed, with layered arrangement and distribution ratio, generates a large amount of reducing gas, fully realizes the recycling and reuse of CO2 and the formation of reducing atmosphere, and effectively reduces the amount of NOx generated during the combustion process. O ₂ is fully utilized to achieve segmented arrangement, strengthen the mixing with incineration flue gas, ensure full gas phase combustion, and oxygen-enriched high-temperature melting effectively solves the problem of coking in the throat of the incinerator, and at the same time greatly reduces the amount of flue gas in the entire incineration system. , reduce the power consumption of the induced draft fan, the concentration of pollutants, and realize the low-carbon, energy-saving, efficient and clean incineration of waste.

The specific embodiments described above further describe the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above descriptions are only specific embodiments of the present invention, and are not intended to limit the present invention. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims (6)

1. The utility model provides a high-efficient clean msw incineration system of low nitrogen oxygen boosting which characterized in that: involving pressure swing adsorption of O ₂ The system comprises a separator (10), a flue gas fan (3), a flue gas steam heat exchanger (9), an incinerator (11), a waste heat boiler (12), a semi-dry reaction tower (13), a bag-type dust collector (14), an induced draft fan (15), a chimney (16), an oxygen-enriched fan (4), an oxygen-enriched pipeline (17) and an oxygen-enriched air inlet pipeline (5);

the pressure swing adsorption of O ₂ The separator (10), the flue gas fan (3), the flue gas steam heat exchanger (9), the incinerator (11), the waste heat boiler (12), the semi-dry reaction tower (13), the bag-type dust collector (14) and the induced draft fan (15) are sequentially connected through pipelines;

the induced draft fan (15) and the pressure swing adsorption O ₂ The separators (10) are respectively connected to a chimney (16) through pipelines;

the pressure swing adsorption of O ₂ The separator (10) is connected to the incinerator (11) through an oxygen-enriched pipeline (17), one end of the oxygen-enriched air inlet pipeline (5) is connected to the oxygen-enriched pipeline (17), the other end of the oxygen-enriched air inlet pipeline is connected to the incineration room of the waste heat boiler (12), and the oxygen-enriched fan (4) is installed on the oxygen-enriched pipeline.

2. The low-nitrogen, oxygen-enriched, high-efficiency and clean waste incineration system of claim 1, wherein: the incinerator (11) comprises a furnace body (18), an oxygen-free flue gas air distribution pipeline (19), a primary air pipeline (20) and an oxygen-enriched air supplementing air distribution pipeline (21), wherein the furnace body (18) comprises a feed inlet (22) on the side portion and a flue gas outlet (23) on the upper portion, the flue gas outlet (23) is communicated with a waste heat boiler (12), the bottom of the furnace body (18) is provided with an inclined plane, the inclined plane is provided with five units from top to bottom, the five units are respectively a first unit, a second unit, a third unit, a fourth unit and a fifth unit, each unit corresponds to one air pipe and is respectively a first section, a second section, a third section, a fourth section and a fifth section, each air pipe is provided with one fan, one end of the oxygen-free flue gas air distribution pipeline (19) is connected with a flue gas vapor heat exchanger (9), the other end of the oxygen-free flue gas air distribution pipeline is communicated with the first section, the second section and the third section, the primary air pipeline (20) is communicated with the third section, the fourth section and the fifth section, the oxygen-enriched air supplementing pipeline (21) one end of the oxygen-enriched air distribution pipeline is connected to the flue gas outlet (23).

3. The low-nitrogen oxygen-rich high-efficiency clean waste incineration system according to claim 2, characterized in that: flue gas outlet (23) department has oxygen boosting wind inlet (8) and oxygen boosting wind inlet (7) that descends, oxygen boosting wind distribution pipeline (21) communicates oxygen boosting wind inlet (8) and oxygen boosting wind inlet (7) that descend respectively, and the amount of wind ratio 3 of oxygen boosting wind inlet (8) and oxygen boosting wind inlet (7) that descends: 7.

4. the low-nitrogen oxygen-rich high-efficiency clean waste incineration system according to claim 2, characterized in that: o in the oxygen-rich pipeline (17) ₂ The concentration is more than 95%.

5. The low-nitrogen oxygen-rich high-efficiency clean waste incineration system according to claim 2, characterized in that: the temperature of the flue gas entering the incinerator (11) through the flue gas vapor heat exchanger (9) is 250 ℃.

6. The incineration method of the low-nitrogen oxygen-enriched high-efficiency clean waste incineration system according to any one of the claims 1 to 5, comprising the following steps:

the method comprises the following steps: a part of the flue gas in the chimney (16) is extracted by the oxygen-enriched fan (4) and enters the pressure swing adsorption O ₂ A separator (10) for separating O ₂ Separating with oxygen-free flue gas, wherein the residual substances in the oxygen-free flue gas are mainly N ₂ CO ₂ And H ₂ O；

Step two: after being sucked by a flue gas fan (3), the oxygen-free flue gas passes through a flue gas steam heat exchanger (9) and is heated from 120 ℃ to 250 ℃;

step three: the heated oxygen-free flue gas enters a first section and a second section of the incinerator (11) to ensure that drying and partial pyrolysis are carried out under the oxygen-free condition;

step four: the third unit being conventional refuse incinerationThe mode is that air is introduced and a small amount of oxygen-free flue gas is also introduced, the air passing coefficient is controlled to be 0.3-0.5, the radiant heat is transferred to the second unit when partial combustion and pyrolysis are carried out, and high-concentration CO is ensured to be generated in the pyrolysis process of the second unit ₂ Reacting with C in the garbage, wherein the reaction formula is as follows:

C+CO ₂ ＝2CO

C+H ₂ O＝CO+H ₂

further, not only the reducing gas itself but also CO are pyrolyzed ₂ 、H ₂ O further generates a large amount of reducing gas;

step five: sufficient air is introduced into the fourth unit, the coefficient of the excess air is about 1.1, and a part of area of the fifth unit enters a stage of solid-phase product air combustion to be fully combusted, so that a large amount of NO is generated, and the NO reacts with reducing gas generated by the second unit and the third unit in an incineration hearth to reduce NOx and simultaneously react with CO to reduce NOx ₂ A large amount of consumption;

step six: the gas having interacted contains partial unburned components, and is subjected to "oxygen-enriched combustion stage" at the upper part of the incinerator (11) for full combustion, and pressure swing adsorption of O ₂ The oxygen separated by the separator (10) is sucked by an oxygen-enriched fan (4) and is divided into two paths to be sprayed to the upper part of the incinerator (11), the proportion of the upper path is 10-30 percent, and the proportion of the lower path is 90-70 percent; the valve opening of the oxygen-enriched air inlet pipeline (5) is properly opened according to the indexes of pollutants in the flue gas, and a proper amount of air is supplemented from the incineration chamber, so that oxygen-enriched combustion is still ensured; when the unburned gas is fully combusted, the temperature of the throat part is improved due to gas-phase combustion, the phenomenon of coking of the throat part of the garbage incinerator is inhibited to a great extent, and meanwhile, the standard emission of dioxin is further ensured.

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