CN120274289A

CN120274289A - Energy-saving type waste incineration flue gas purification device and purification process

Info

Publication number: CN120274289A
Application number: CN202510429911.4A
Authority: CN
Inventors: 李新; 付志臣; 周飞飞; 孙丽娟; 吴永新; 黄浩; 路畅; 洪益州
Original assignee: Halo Zhichuang Environmental Protection Equipment Jiangsu Co ltd; Everbright Environmental Protection Technology Equipment Changzhou Co Ltd
Current assignee: Halo Zhichuang Environmental Protection Equipment Jiangsu Co ltd; Everbright Environmental Protection Technology Equipment Changzhou Co Ltd
Priority date: 2025-04-08
Filing date: 2025-04-08
Publication date: 2025-07-08

Abstract

The invention discloses an energy-saving type waste incineration flue gas purifying device and a purifying process. The energy-saving type waste incineration flue gas purification device realizes the multistage purification and energy recovery of flue gas through the combination of an incinerator, a waste heat boiler, a dust removal device, an SCR device, a GGH device and the like. The arrangement of the dry method device and the SNCR device in the furnace can be used for preliminary deacidification and denitration in the incineration process, so that the burden of subsequent treatment is reduced. The introduction of the condensing heat exchanger further utilizes sensible heat and latent heat in the flue gas, improves the energy utilization efficiency and reduces the energy consumption. The invention solves the contradiction that denitration needs to be heated and deacidified needs to be cooled, recovers the waste heat of the flue gas, and couples and transfers heat to SCR, so that the method can remove pollutants with high efficiency, realize ultralow emission, fully utilize the latent heat and sensible heat of the flue gas, and effectively improve the energy utilization rate.

Description

Energy-saving type waste incineration flue gas purification device and purification process

Technical Field

The invention relates to the technical field of flue gas treatment, in particular to the technical field of waste incineration flue gas purification, and specifically relates to an energy-saving waste incineration flue gas purification device and a purification process.

Background

The waste incineration flue gas pollutants mainly comprise particulate matters (such as fly ash and smoke dust), acid gases (such as sulfur dioxide and hydrogen chloride), nitrogen oxides, heavy metals (such as lead, mercury and cadmium), organic pollutants (such as dioxin and the like) and greenhouse gases (such as carbon dioxide). Common waste incineration deacidification methods include a waste incineration common deacidification method mainly comprising a wet method, a dry method and a semi-dry method. The wet deacidification efficiency is high, the removal efficiency of HCl can reach more than 99 percent, and the removal efficiency of SO2 can also reach more than 95 percent. A great amount of waste water is produced, a waste water treatment device is needed to be arranged, but the temperature of the deacidified flue gas is lower, and a flue gas reheating device is needed to be arranged to prevent chimney corrosion and white smoke. The dry method has the advantages of small investment, simple equipment, convenient maintenance and difficult blockage. However, the solid-liquid phase contact time is shorter, more medicines are needed to be consumed, and the purification efficiency is relatively lower. The semi-dry method combines the advantages of the dry method and the wet method, the deacidification efficiency is higher (90% -99%), the equipment is simple, and the operation is stable. The technical route is mature, and sewage discharge is rarely generated. However, the requirements on the operation level are high, and the residence time and the temperature difference between the inlet and the outlet of the reaction tower are required to be strictly controlled. Common garbage incineration and denitration methods mainly comprise selective non-catalytic reduction (SNCR), selective Catalytic Reduction (SCR) and SNCR/SCR combined technology. The SNCR technology has the advantages of no need of a catalyst, low equipment cost, simple and convenient operation, limited denitration efficiency (30% -65%), strict reaction temperature requirement, high ammonia escape and easy secondary pollution. SCR technology denitration efficiency is high (can reach more than 90%), and ammonia escape is few, and is strong to flue gas operating mode adaptability, but catalyst cost is high, needs the intensification. The SNCR/SCR combined technology combines the advantages of the two, the denitration efficiency is high (more than 80% -90%), the catalyst consumption is reduced, but the system is complex, and the investment and maintenance cost is relatively high. For dioxin, heavy metals and dust removal, a common method is a dry activated carbon plus dust remover.

At present, the conventional process route of garbage incineration is SNCR+semi-dry method+dry method+bag-type dust collector, the system can realize a certain degree of pollutant, the process chain is simple, the technology is mature, but ultra-low emission cannot be realized, and SCR and wet method are added on the basis of the above. At present, two technological routes of ultra-low emission are available, one is SNCR+semi-dry method+dry method+bag-type dust remover

+SGH+SCR+ GGH + wet process, one is SNCR+semi-dry method+dry method+bag-type dust collector+GGH1+wet method+GGH2+SGH+SCR.

However, the two discharge routes described above have the following disadvantages:

(1) The SNCR, the semi-dry method, the bag-type dust remover, the SGH, the SCR, the GGH and the wet process are adopted as main means of deacidification, water is sprayed to cool down in the process, and energy is transferred to latent heat of flue gas, the subsequent SCR denitration step requires to heat up again after the semi-dry method, so that unnecessary energy consumption is caused, the running cost is further increased, and the overall energy efficiency is reduced;

(2) SNCR+semi-dry method+dry method+bag-type dust collector+GGH1+wet method

The +GGH2+SGH+SCR process is also a primary means of deacidification by a semi-dry method, water is sprayed in the process for cooling, energy is transferred to latent heat of flue gas, the later wet method is used for cooling, and the temperature is raised by the process combination of GGH2+SGH after the two times of cooling, so that unnecessary energy consumption is further caused, the running cost is further increased, and the overall energy efficiency is reduced.

Disclosure of Invention

The invention solves the technical problems of overcoming the defects in the prior art, providing an energy-saving waste incineration flue gas purification device and a purification process, solving the contradiction that denitration needs to be heated and deacidification needs to be cooled, recovering the waste heat of flue gas, coupling heat transfer to SCR, removing pollutants with high efficiency, realizing ultralow emission, fully utilizing the latent heat and sensible heat of the flue gas, and effectively improving the energy utilization rate.

The technical scheme adopted for solving the technical problems is as follows:

an energy-saving type waste incineration flue gas purification device is sequentially provided with an incinerator, a waste heat boiler, a dust removal device, an SCR device, a GGH1 device, a GGH2 device, a GGH3 device, an induced draft fan and a chimney along a waste incineration flue gas travelling route, wherein the incinerator is connected with an air preheater for providing air for the incinerator;

The device also comprises an in-furnace dry method device and an SNCR device, wherein the in-furnace dry method device sprays deacidification agent powder into the hearth of the incinerator, and the SNCR device sprays denitration agent powder into the flue of the waste heat boiler;

The heat exchange assembly further comprises a heat exchange assembly for utilizing sensible heat and latent heat in the flue gas, the heat exchange assembly comprises a condensation heat exchanger, the condensation heat exchanger is provided with an air inlet, an air outlet, a flue gas inlet and a flue gas outlet, the air outlet of the condensation heat exchanger is connected with the GGH1 device through a pipeline, the air outlet of the GGH1 device is connected with the air inlet of the SCR device through a pipeline, and the GGH1 device provides dilution wind and seal wind for the SCR device.

The multi-stage purification and energy recovery of the flue gas are realized through the combination of the incinerator, the waste heat boiler, the dust removing device, the SCR device, the GGH device and the like. The arrangement of the dry method device and the SNCR device in the furnace can be used for preliminary deacidification and denitration in the incineration process, so that the burden of subsequent treatment is reduced. The introduction of the condensing heat exchanger further utilizes sensible heat and latent heat in the flue gas, improves the energy utilization efficiency and reduces the energy consumption.

Further, the dust collector comprises an activated carbon device and a cloth bag dust collector, the feeding end of the activated carbon device is connected with the discharging end of the waste heat boiler, the discharging end of the activated carbon device is connected with the feeding end of the cloth bag dust collector, and the discharging end of the cloth bag dust collector is connected with the feeding end of the SCR device.

Through the combination of active carbon device and sack cleaner, can effectively get rid of heavy metal and dust in the flue gas, ensure that the flue gas has passed preliminary purification before getting into the SCR device, reduce the load of SCR device, prolonged its life.

Further, the energy-saving type waste incineration flue gas purification device also comprises a wet tower, wherein a flue gas inlet of the wet tower is connected with a flue gas outlet of the GGH2 device, the flue gas outlet of the wet tower is connected with a flue gas inlet of a condensing heat exchanger, and the flue gas outlet of the condensing heat exchanger is connected with the GGH2 device through a pipeline.

The arrangement of the wet tower further enhances the deacidification effect, and particularly acidic substances in the flue gas are further removed after the GGH2 device, so that the discharged flue gas is ensured to meet the environmental protection standard. The use of the condensing heat exchanger further recovers heat in the flue gas, and improves the energy utilization rate.

Further, the GGH3 device is provided with an air inlet and an air outlet, and the air outlet of the GGH3 device is connected with the air inlet of the air preheater through a pipeline.

The GGH3 device is arranged to enable the flue gas to exchange heat with primary air, so that heat in the flue gas is further recovered, the final discharge temperature of the flue gas is reduced, the temperature of the primary air entering the incinerator is improved, and the energy consumption of the incinerator is reduced.

The energy-saving type waste incineration flue gas purification process uses the energy-saving type waste incineration flue gas purification device, and the purification process specifically comprises the following steps of:

step S1, the incinerator adopts 200 ℃ air of an air preheater as primary air, and generated flue gas is firstly subjected to preliminary deacidification by an in-furnace dry method device, so that the concentration of acid pollutants is reduced;

s2, after preliminary deacidification, performing preliminary denitration by an SNCR device of a flue;

S3, after the flue gas subjected to preliminary denitration passes through a waste heat boiler, controlling the temperature to be about 190 ℃;

S4, removing heavy metals and dust from the flue gas at the outlet of the waste heat boiler through an activated carbon device and a bag-type dust remover;

S5, flue gas at the outlet of the bag-type dust collector is subjected to further denitration by an SCR device, wherein the outlet temperature of the flue gas of the bag-type dust collector is 185 ℃, and the SCR device uses 170 ℃ air from the GGH1 device as dilution air and sealing air;

S6, enabling flue gas at an outlet of the SCR device to enter a GGH1 device to exchange heat with air from a condensation heat exchanger, and reducing the temperature to 165 ℃, wherein the GGH1 device heats the air from the condensation heat exchanger from 60 ℃ to 170 ℃ at the same time, and the heated air is sent to the SCR device;

S7, enabling the flue gas at the outlet of the GGH1 device to enter the GGH2 device to exchange heat with the deacidified clean flue gas from the condensing heat exchanger, and reducing the temperature to 95 ℃;

s8, the dirty flue gas at the outlet of the GGH2 device enters a wet tower for further deacidification, the moisture in the dirty flue gas is increased to be near a saturated state, and the temperature is reduced to 60-65 ℃;

s9, enabling clean flue gas at the outlet of the wet tower to enter a condensing heat exchanger for heat exchange, heating the sent air by utilizing sensible heat and latent heat in the flue gas, and then, heating the air to 60 ℃ and then, removing the air to a GGH1 device;

s10, carrying out heat exchange between a GGH2 removing device of clean flue gas after condensing a heat exchanger and dirty flue gas from the GGH1 device, and raising the temperature to 120 ℃;

S11, the clean flue gas heated by the GGH2 device enters the GGH3 device to exchange heat with primary air, the temperature of the flue gas is reduced to 55 ℃, the temperature of the primary air is increased to 115 ℃, and the primary air is heated to 200 ℃ again through the air preheater and is sent into the incinerator;

And S12, after heat exchange of the GGH3 device, the flue gas is pumped away by an induced draft fan and is discharged from a chimney.

The process ensures the efficient purification of the flue gas and the full utilization of energy through multistage deacidification, denitration, dust removal and energy recovery. The whole process is reasonable in design, can effectively reduce the emission of pollutants, and simultaneously improves the energy utilization efficiency.

Further, air at 20-40 ℃ is introduced into the air inlet of the GGH3 device. 20-40 ℃ of air is introduced into an air inlet of the GGH3 device, so that the maximization of heat exchange efficiency is ensured, and equipment damage or efficiency reduction caused by overhigh or overlow temperature is avoided.

Further, air at 20-40 ℃ is introduced into the air inlet of the condensing heat exchanger. The air at 20-40 ℃ is introduced into the air inlet of the condensing heat exchanger, so that the heat in the flue gas can be efficiently recovered by the heat exchanger, and meanwhile, the heat exchange efficiency reduction caused by overhigh air temperature is avoided.

Further, the temperature of the outlet flue gas of the SCR device is 180 ℃. The temperature of the flue gas at the outlet of the SCR device is 180 ℃, so that the SCR device is ensured to operate in an optimal temperature range, the denitration efficiency is improved, and meanwhile, the catalyst deactivation or efficiency reduction caused by overhigh or overlow temperature is avoided.

The invention has the beneficial effects that the design is reasonable, and the invention has the following advantages:

(1) The method adopts the combination of the dry method device in the furnace and the SCR device, and arranges the combination before the wet deacidification process, so that SGH (SGH must be arranged in the prior art) of the SCR device is omitted, the contradiction between the heating requirement in the denitration process and the cooling requirement in the deacidification process is solved, and the total operation cost is effectively reduced by omitting the extra energy consumption required by denitration heating;

(2) The dilution wind and the sealing wind of the SCR device are heated by the condensing heat exchanger and the GGH1 device, so that the energy consumption required by heating the wind is avoided, the energy waste is reduced, and the running cost is reduced;

(3) The flue gas at the outlet of the wet tower enters the GGH2 device after entering the condensation heat exchanger, so that the moisture in the flue gas is reduced, the latent heat and the sensible heat of the flue gas are utilized, the energy utilization rate is improved, the pollutant concentration is reduced, the negative effect caused by the wet water spraying is solved, and the possibility of white fog in the flue gas is reduced;

(4) The flue gas is firstly cooled and the moisture is removed through the condensing heat exchanger, so that conditions are created for the subsequent final reduction of the temperature of the flue gas to 55 ℃, and meanwhile, the acid moisture of the flue gas is effectively prevented from being separated out from the induced draft fan and the chimney, and the risk of corrosion of the induced draft fan and the chimney caused by the acid moisture is further reduced;

(5) The final heat of the system is exchanged to primary air through the GGH3 device, the temperature of a flue gas outlet is reduced to 55 ℃, and the waste heat of the flue gas is utilized to the greatest extent;

(6) And by adopting three GGH and condensing heat exchangers, sensible heat and latent heat in the flue gas are utilized in a cascade manner, the discharge temperature is reduced to the greatest extent, and the energy utilization rate is high.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings that are needed in the description of the embodiments or the prior art will be briefly described, and it is obvious that the drawings in the description below are some embodiments of the present invention, and other drawings can be obtained according to the drawings without inventive effort for a person skilled in the art.

Fig. 1 is a schematic structural view of an energy-saving type garbage incineration flue gas purifying device in the invention.

In the figure, the incinerator is 1, the dry method device in the incinerator is 2, the SNCR device is 3, the waste heat boiler is 4, the active carbon device is 5, the bag-type dust remover is 6, the SCR device is 7, the 8.GGH1 device is 9.GGH2 device is 10.GGH3 device is 11, the induced draft fan is 12, the chimney is 13, the wet method tower is 14, the condensing heat exchanger is 15, and the air preheater is 15.

Detailed Description

It should be noted that the following detailed description is illustrative and is intended to provide further explanation of the application. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs.

It is noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of exemplary embodiments according to the present application. As used herein, the singular forms also include the plural unless the context clearly indicates otherwise, and furthermore, it is to be understood that when the terms "comprises" and/or "comprising" are used in this specification, they specify the presence of stated features, steps, operations, devices, components, and/or combinations thereof.

The technical solutions of the present invention will be clearly and completely described in connection with the embodiments, and it is apparent that the described embodiments are some embodiments of the present invention, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.

Noun interpretation:

Incinerator overview an incinerator is a key device for innocuous treatment of garbage or biomass, and its core mechanism is to promote decomposition of organic matters in solid waste into harmless gas, water vapor and ash slag through high temperature environment (the temperature range is usually 850 ℃ to 1100 ℃).

The flue gas refers to gas, particulate pollutants and mixed substances thereof released in the process of incinerating garbage or biomass. The waste incineration flue gas pollutants mainly comprise particulate matters (such as fly ash and smoke dust), acid gases (such as sulfur dioxide and hydrogen chloride), nitrogen oxides, heavy metals (such as lead, mercury and cadmium), organic pollutants (such as dioxin and the like) and greenhouse gases (such as carbon dioxide).

The technology involves adding desulfurizing agents such as limestone, gypsum and the like into an incinerator, and the additives chemically react with sulfur dioxide generated by combustion at high temperature to generate soluble calcium sulfur compounds such as calcium sulfate and the like, thereby effectively achieving the deacidification purpose.

Waste heat boiler the waste heat boiler is the core equipment of waste incineration waste heat recovery system. The high-temperature flue gas generated by the incinerator is utilized to pass through a heating surface to transfer heat energy to water in the boiler, so that the water is changed into high-temperature and high-pressure steam.

SNCR is a selective, non-catalytic flue gas denitration method. The method is characterized in that a reducing agent (such as urea solution, ammonia water solution and the like) containing ammonia free radicals is directly sprayed into a flue or a secondary flue of an incinerator under the high temperature condition (usually 850-1200 ℃), so that the reducing agent and nitrogen oxides (NOx) in flue gas are subjected to chemical reaction to generate nitrogen (N ₂) and water (H ₂ O), and the purpose of removing the NOx is achieved.

And the activated carbon system is a purification treatment system for adsorbing and removing harmful substances (such as heavy metals, dioxin and the like) in the flue gas by spraying activated carbon.

The cloth bag dust remover is key equipment for removing dust, heavy metal, dioxin and other harmful substances generated in the incineration process in a garbage incineration flue gas treatment system, has the advantages of high-efficiency filtration, high temperature resistance, corrosion resistance and the like, and ensures that the flue gas emission accords with the environmental protection standard by filtering the flue gas through cloth bag materials.

SCR (SELECTIVE CATALYTIC Reduction) refers to a selective catalytic Reduction technology in garbage incineration, and is an efficient flue gas denitration technology. The catalyst is used for reacting nitrogen oxides (NOx) in the flue gas with a reducing agent (such as ammonia gas) at a lower temperature (usually 200-450 ℃), so that harmless nitrogen and water are generated, and the flue gas is purified, and the atmospheric pollution is reduced.

GGH (Gas-GAS HEATER, flue Gas-flue Gas heat exchanger) is a high-efficiency heat energy recovery device, which utilizes heat exchange between high-temperature flue Gas and low-temperature flue Gas to effectively reduce the flue Gas emission temperature, and simultaneously preheats air entering a boiler or recovers heat energy for other technological processes, thereby improving the energy utilization efficiency of the whole system.

SGH refers to steam-flue gas heater (STEAM GAS HEATER). The flue gas reheating system heats flue gas with lower temperature at the outlet of a bag type dust collector to a temperature range suitable for denitration of an SCR (selective catalytic reduction) system in a steam direct heating mode, and the running temperature of an SCR catalyst is 170-200 ℃ generally. SGH plays a key role in the waste incineration flue gas purification process, and is beneficial to improving the stability and denitration efficiency of an SCR system, so that the emission of nitrogen oxides generated in the waste incineration process is effectively controlled.

Wet method is a technology for purifying flue gas in the garbage incineration process. The method utilizes alkaline solution (such as limestone solution) to carry out chemical reaction with acid gases (such as HCl, SO2 and the like) in the flue gas in a washing tower to generate salts and water, thereby removing acid components in the flue gas and achieving the purpose of deacidification. The wet deacidification has high efficiency, but has higher requirements on equipment, and a large amount of wastewater can be generated, and a wastewater treatment device is required to be configured.

The condensing heat exchanger is one kind of equipment for recovering and utilizing the latent heat of vaporization of water vapor in fume during garbage burning. By reducing the temperature of the discharged smoke to below the saturation temperature, superheated water vapor in the smoke is condensed into liquid water, and latent heat of vaporization is released, so that the heat exchange efficiency is improved. The condensing heat exchanger can effectively improve the energy utilization rate of the incineration system, reduce heat loss, simultaneously be beneficial to purifying the flue gas and reducing pollutant emission, and is an important component in the garbage incineration technology.

The latent heat refers to the heat released when the vapor in the flue gas is converted from the gas state to the liquid state in the garbage incineration process. This heat transfer occurs during flue gas cooling, and when the temperature drops below the dew point, the water vapor condenses into liquid water, releasing a large amount of energy, i.e., latent heat. The recovery and utilization of latent heat are of great significance for improving the energy efficiency of the garbage incineration system and reducing heat loss, and the recovery and utilization can be realized through equipment such as a condensation heat exchanger and the like.

The chimney is a high-rise structure used for discharging waste gas generated by combustion in the garbage incineration equipment. It is an important component of refuse incineration system, and is mainly used for discharging the burnt waste gas out of building.

SCR seal wind refers to an air flow for purging, sealing and protecting, which is purposely introduced in the process of adopting a Selective Catalytic Reduction (SCR) technology to perform flue gas denitration in order to ensure that internal components (such as a catalyst) of an SCR system are not corroded by external flue gas and maintain the tightness of the system. The seal wind is fed into the internal components after being heated, and the seal wind helps to prevent flue gas leakage, protect the catalyst from damage, and maintain the normal operation and high-efficiency denitration of the SCR system.

The SCR dilution wind refers to air flow which is blown by a dilution fan and is used for diluting ammonia gas to a certain proportion and then spraying the diluted ammonia gas into a reactor pipeline in a Selective Catalytic Reduction (SCR) denitration process so as to remove nitrogen oxides in combustion flue gas and achieve the aim of environmental protection.

The ultra-low emission of the waste incineration flue gas refers to that in the waste incineration process, the advanced flue gas treatment process is adopted, so that the emission concentration of pollutants such as smoke dust, sulfur dioxide, nitrogen oxides and the like is greatly reduced, and the emission concentration is far lower than the limit value of the national emission standard, thereby realizing friendly and sustainable development to the environment. Conventional emissions refer to limits that meet national emissions standards.

Example 1

The energy-saving type waste incineration flue gas purification device shown in fig. 1 is provided with an incinerator 1, a waste heat boiler 4, a dust removal device, an SCR device 7, a GGH1 device 8, a GGH2 device 9, a GGH3 device 10, a draught fan 11 and a chimney 12 in sequence along a waste incineration flue gas travelling route, wherein the incinerator 1 is connected with an air preheater 15 for providing air for the incinerator 1, the energy-saving type waste incineration flue gas purification device further comprises an in-furnace dry method device 2 and an SNCR device 3, the in-furnace dry method device 2 sprays deacidification agent powder in a hearth of the incinerator 1, the SNCR device 3 sprays denitration agent powder in a flue of the waste heat boiler 4, the heat exchange assembly comprises a condensation heat exchanger 14, the condensation heat exchanger 14 is provided with an air inlet, an air outlet, a flue gas inlet and a flue gas outlet, the condensation heat exchanger 14 is connected with the GGH1 device 8 through a pipeline, the air outlet of the GGH1 device 8 is connected with the air inlet of the SCR device 7 through a pipeline, and the GGH1 device 8 provides dilution air and sealing air for the SCR device 7.

The dust collector comprises an activated carbon device 5 and a cloth bag dust collector 6, wherein the feeding end of the activated carbon device 5 is connected with the discharging end of the waste heat boiler 4, the discharging end of the activated carbon device 5 is connected with the feeding end of the cloth bag dust collector 6, and the discharging end of the cloth bag dust collector 6 is connected with the feeding end of the SCR device 7.

The energy-saving type waste incineration flue gas purification device further comprises a wet tower 13, wherein a flue gas inlet of the wet tower 13 is connected with a flue gas outlet of the GGH2 device 9, a flue gas outlet of the wet tower 13 is connected with a flue gas inlet of a condensation heat exchanger 14, and a flue gas outlet of the condensation heat exchanger 14 is connected with the GGH2 device 9 through a pipeline.

The GGH3 apparatus 10 is provided with an air inlet and an air outlet, and the air outlet of the GGH3 apparatus 10 is connected to an air inlet of the air preheater 15 through a pipeline.

The energy-saving type waste incineration flue gas purification process uses the energy-saving type waste incineration flue gas purification device, and specifically comprises the following steps of:

step S1, the incinerator 1 adopts 200 ℃ air of the air preheater 15 as primary air, and generated flue gas is firstly subjected to preliminary deacidification by the dry-method device 2 in the incinerator, so that the concentration of acid pollutants is reduced;

s2, after preliminary deacidification, performing preliminary denitration by an SNCR device 3 of a flue;

s3, after the flue gas subjected to preliminary denitration passes through the waste heat boiler 4, controlling the temperature to be about 190 ℃;

s4, removing heavy metals and dust from the flue gas at the outlet of the waste heat boiler 4 through an activated carbon device 5 and a bag-type dust remover 6;

S5, removing the flue gas at the outlet of the bag-type dust collector 6 to the SCR device 7 for further denitration, wherein the outlet temperature of the flue gas of the bag-type dust collector 6 is 185 ℃, and the SCR device 7 uses 170 ℃ air from the GGH1 device 8 as dilution air and sealing air;

S6, enabling flue gas at the outlet of the SCR device 7 to enter the GGH1 device 8 to exchange heat with air from the condensation heat exchanger 14, and reducing the temperature to 165 ℃, wherein the GGH1 device 8 heats the air from the condensation heat exchanger 14 from 60 ℃ to 170 ℃ at the same time, and the heated air is sent to the SCR device 7;

s7, enabling the flue gas at the outlet of the GGH1 device 8 to enter the GGH2 device 9 to exchange heat with the deacidified clean flue gas from the condensation heat exchanger 14, and reducing the temperature to 95 ℃;

S8, the dirty flue gas at the outlet of the GGH2 device 9 enters a wet tower 13 for further deacidification, the moisture in the dirty flue gas is increased to be near a saturated state, and the temperature is reduced to 60-65 ℃;

S9, clean flue gas at the outlet of the wet tower 13 enters a condensing heat exchanger 14 to exchange heat, sensible heat and latent heat in the flue gas are utilized to heat the sent air, and the air is heated to 60 ℃ and then goes to the GGH1 device 8;

S10, carrying out heat exchange between the clean flue gas which is condensed with the heat exchanger 14 and the GGH2 removing device 9 and the dirty flue gas which is discharged from the GGH1 device 8, and raising the temperature to 120 ℃;

S11, the clean flue gas heated by the GGH2 device 9 enters the GGH3 device 10 to exchange heat with primary air, the temperature of the flue gas is reduced to 55 ℃, the temperature of the primary air is increased to 115 ℃, and the primary air is heated to 200 ℃ again through the air preheater 15 and is sent into the incinerator 1;

And S12, after heat exchange of the GGH3 device 10, the flue gas is pumped away by the induced draft fan 11 and is discharged from the chimney 12.

20-40 ℃ Of air is introduced into the air inlet of the GGH3 device 10, and 20-40 ℃ of air is introduced into the air inlet of the condensing heat exchanger 14.

The temperature of the flue gas at the outlet of the SCR device 7 is 180 ℃.

In conclusion, the invention realizes the efficient purification of the flue gas and the full utilization of energy through multistage purification, energy recovery and efficient heat exchange. The specific effects include:

(1) The high-efficiency purification ensures that pollutants such as acidic substances, heavy metals, dust, nitrogen oxides and the like in the flue gas are effectively removed by multistage purification such as an in-furnace dry method device 2, an SNCR device 3, an active carbon device 5, a bag-type dust collector 6, an SCR device 7, a wet method tower 13 and the like, and the discharged flue gas meets the environmental protection standard;

(2) The sensible heat and the latent heat in the flue gas are fully recovered through the use of the three GGH devices and the condensing heat exchanger 14, so that the energy consumption is reduced, and the energy utilization efficiency is improved;

(3) The method is energy-saving and environment-friendly, the whole process is reasonable in design, energy consumption is reduced, operation cost is reduced, and meanwhile, pollutant emission is reduced, so that the method meets the requirements of energy conservation and environment protection;

(4) And the service life of the equipment is prolonged, the loads of key equipment such as SGH in the SCR device are reduced through multistage purification, the service life of the equipment is prolonged, and the maintenance cost is reduced.

In general, the device and the process realize the efficient recovery and the utilization of energy while ensuring the flue gas purification effect, and have remarkable energy-saving and environment-friendly benefits.

It should be noted that the above embodiments are merely for illustrating the technical solution of the present invention and not for limiting the same, and although the present invention has been described in detail with reference to the above embodiments, it should be understood by those skilled in the art that the technical solution described in the above embodiments may be modified or some or all of the technical features may be equivalently replaced, and these modifications or substitutions do not make the essence of the corresponding technical solution deviate from the scope of the technical solution of the embodiments of the present invention.

Claims

1. An energy-saving type waste incineration flue gas purification device is characterized in that an incinerator (1), a waste heat boiler (4), a dust removal device, an SCR device (7), a GGH1 device (8), a GGH2 device (9), a GGH3 device (10), an induced draft fan (11) and a chimney (12) are sequentially arranged along a waste incineration flue gas travelling route, and the incinerator (1) is connected with an air preheater (15) for providing air for the incinerator (1);

The device also comprises an in-furnace dry method device (2) and an SNCR device (3), wherein the in-furnace dry method device (2) sprays deacidification agent powder in the hearth of the incinerator (1), and the SNCR device (3) sprays denitration agent powder in the flue of the waste heat boiler (4);

The heat exchange assembly further comprises a heat exchange assembly for utilizing sensible heat and latent heat in the flue gas, the heat exchange assembly comprises a condensation heat exchanger (14), the condensation heat exchanger (14) is provided with an air inlet, an air outlet, a flue gas inlet and a flue gas outlet, the air outlet of the condensation heat exchanger (14) is connected with the GGH1 device (8) through a pipeline, the air outlet of the GGH1 device (8) is connected with the air inlet of the SCR device (7) through a pipeline, and the GGH1 device (8) provides dilution wind and sealing wind for the SCR device (7).

2. The energy-saving type waste incineration flue gas purification device according to claim 1, wherein the dust removal device comprises an activated carbon device (5) and a cloth bag dust remover (6), the feeding end of the activated carbon device (5) is connected with the discharging end of the waste heat boiler (4), the discharging end of the activated carbon device (5) is connected with the feeding end of the cloth bag dust remover (6), and the discharging end of the cloth bag dust remover (6) is connected with the feeding end of the SCR device (7).

3. The energy-saving garbage incineration flue gas purification device according to claim 1, further comprising a wet tower (13), wherein a flue gas inlet of the wet tower (13) is connected with a flue gas outlet of the GGH2 device (9), a flue gas outlet of the wet tower (13) is connected with a flue gas inlet of a condensing heat exchanger (14), and a flue gas outlet of the condensing heat exchanger (14) is connected with the GGH2 device (9) through a pipeline.

4. The energy-saving type waste incineration flue gas purification device according to claim 1, wherein the GGH3 device (10) is provided with an air inlet and an air outlet, and the air outlet of the GGH3 device (10) is connected with an air inlet of an air preheater (15) through a pipeline.

5. The purification process of energy-saving type waste incineration flue gas is characterized by using the energy-saving type waste incineration flue gas purification device as claimed in any one of claims 1-4, and specifically comprises the following steps:

Step S1, the incinerator (1) adopts 200 ℃ air used as primary air of an air preheater (15), and generated flue gas is firstly subjected to preliminary deacidification through an in-furnace dry method device (2) to reduce the concentration of acidic pollutants;

s2, after preliminary deacidification, performing preliminary denitration by an SNCR device (3) of a flue;

S3, after the flue gas subjected to preliminary denitration passes through a waste heat boiler (4), controlling the temperature to be about 190 ℃;

S4, removing heavy metals and dust from flue gas at an outlet of the waste heat boiler (4) through an activated carbon device (5) and a bag-type dust remover (6);

S5, flue gas at the outlet of the bag-type dust collector (6) is further denitrated by an SCR device (7), the outlet temperature of the flue gas of the bag-type dust collector (6) is 185 ℃, and the SCR device (7) uses 170 ℃ air from a GGH1 device (8) as dilution air and sealing air;

S6, enabling flue gas at the outlet of the SCR device (7) to enter the GGH1 device (8) to exchange heat with air from the condensing heat exchanger (14), and reducing the temperature to 165 ℃, heating the air from the condensing heat exchanger (14) from 60 ℃ to 170 ℃ by the GGH1 device (8), and enabling the heated air to enter the SCR device (7);

s7, enabling flue gas at an outlet of the GGH1 device (8) to enter the GGH2 device (9) to exchange heat with deacidified clean flue gas from the condensing heat exchanger (14), and reducing the temperature to 95 ℃;

s8, the dirty flue gas at the outlet of the GGH2 device (9) enters a wet tower (13) for further deacidification, the moisture in the dirty flue gas is increased to be near a saturated state, and the temperature is reduced to 60-65 ℃;

S9, clean flue gas at the outlet of the wet tower (13) enters a condensing heat exchanger (14) for heat exchange, sensible heat and latent heat in the flue gas are utilized for heating the sent air, and the air is sent to a GGH1 device (8) after being heated to 60 ℃;

S10, carrying out heat exchange between a GGH2 removing device (9) of clean flue gas after condensing a heat exchanger (14) and dirty flue gas from a GGH1 device (8), and raising the temperature to 120 ℃;

S11, the clean flue gas heated by the GGH2 device (9) enters the GGH3 device (10) to exchange heat with primary air, the temperature of the flue gas is reduced to 55 ℃, the temperature of the primary air is increased to 115 ℃, and the primary air is heated to 200 ℃ again through the air preheater (15) and is sent into the incinerator (1);

and S12, after heat exchange of the GGH3 device (10), the flue gas is pumped away by an induced draft fan (11) and is discharged from a chimney (12).

6. The process for purifying flue gas generated by energy-saving garbage incineration according to claim 5, wherein the air inlet of the GGH3 device (10) is filled with air at 20-40 ℃.

7. The process for purifying flue gas generated by energy-saving garbage incineration according to claim 5, wherein the air inlet of the condensing heat exchanger (14) is filled with air at 20-40 ℃.

8. The process for purifying energy-saving garbage incineration flue gas according to claim 5, wherein the temperature of the flue gas at the outlet of the SCR device (7) is 180 ℃.