Circulating fluidized bed boiler system for incinerating sludge at low heating value

Abstract

The invention relates to the technical field of sludge treatment, in particular to a low-calorific-value incineration sludge circulating fluidized bed boiler system which comprises a sludge component monitoring module, a fuel proportion adjusting module, a drying and gasifying module, a staged combustion module, a heat energy recycling and power generating module, an ash sorting module and a flue gas purifying module. Wherein the sludge component monitoring module is used for collecting organic matter content, water content and calorific value data of sludge; the fuel ratio adjusting module is used for automatically adjusting the ratio of the sludge to the auxiliary fuel; and the drying and gasifying module is used for receiving the fuel mixture and drying the fuel mixture by utilizing waste heat of the incinerator, and meanwhile, part of organic matters are converted into combustible gas through gasifying treatment. According to the invention, through intelligent fuel adjustment, waste heat recovery and multi-stage flue gas purification technologies, high-efficiency combustion, energy reutilization and up-to-standard emission of the low-calorific-value sludge are realized, and the environmental protection property and economical efficiency of sludge treatment are remarkably improved.

Description

Technical Field

[0001] The invention relates to the technical field of sludge treatment, and in particular to a circulating fluidized bed boiler system for incinerating sludge with a low calorific value. Background Art

[0002] Sludge incineration is one of the important methods of modern sludge treatment. By burning sludge under high temperature conditions, it can effectively achieve sludge reduction, harmlessness and stabilization, thereby meeting environmental protection requirements. A large amount of sludge generated in the process of municipal sewage treatment contains complex organic matter, inorganic matter and heavy metals, and direct landfill or farmland use may bring environmental pollution risks. Incineration technology can decompose the organic components in the sludge through high temperature, completely remove pathogens and convert the sludge into ash, significantly reducing the volume and weight. In addition, the heat generated by the incineration process can be utilized through the waste heat recovery system, which provides favorable conditions for the economy and energy utilization of the system. However, the calorific value of the sludge itself is low and the water content is high. Direct incineration requires a large amount of auxiliary fuel, and the harmful substances that may exist in the flue gas and ash need to be strictly controlled. Therefore, how to achieve efficient sludge incineration and stable waste heat utilization is an important research direction in current sludge treatment technology.

[0003] However, the existing low calorific value sludge incineration system faces many technical difficulties in practical application. First, the low calorific value and high water content of the sludge make the combustion process difficult to stabilize and the fuel consumption is large. The existing system lacks efficient fuel allocation and intelligent combustion control, and it is difficult to effectively adapt to the dynamic changes in sludge composition. Secondly, the high-temperature flue gas and ash generated by the incineration process have a single treatment method, and the waste heat recovery efficiency is low, resulting in serious waste of heat energy. In addition, the flue gas purification device often cannot take into account the multiple functions of dust removal, desulfurization, and denitrification, making it difficult to ensure that emissions meet standards. Summary of the invention

[0004] Based on the above objectives, the present invention provides a low calorific value sludge incineration circulating fluidized bed boiler system.

[0005] A low calorific value sludge incineration circulating fluidized bed boiler system includes a sludge composition monitoring module, a fuel ratio adjustment module, a drying and gasification module, a staged combustion module, a heat recovery and power generation module, an ash sorting module and a flue gas purification module; wherein:

[0006] Sludge composition monitoring module: used to collect data on organic matter content, moisture content and calorific value of sludge, and transmit the collected data to the fuel ratio adjustment module to provide real-time parameters of sludge composition;

[0007] Fuel ratio adjustment module: connected to the sludge composition monitoring module, used to receive the calorific value data of the sludge, and automatically adjust the ratio of the sludge and the auxiliary fuel based on the calorific value data to generate a fuel mixture, and send the fuel mixture to the drying and gasification module;

[0008] Drying and gasification module: connected to the fuel ratio adjustment module, used to receive the fuel mixture and use the waste heat of the incinerator to dry it to reduce the moisture content of the sludge; at the same time, part of the organic matter is converted into combustible gas through gasification, and the generated combustible gas and solid residue are transmitted to the staged combustion module;

[0009] Staged combustion module: connected to the drying and gasification module, used to receive combustible gas and solid residue, and perform staged oxygen supply control in different combustion stages to achieve complete combustion of the fuel, and transmit the high-temperature flue gas generated by combustion to the heat recovery and power generation module;

[0010] Heat recovery and power generation module: connected to the staged combustion module, used to receive high-temperature flue gas and recover heat from it, convert heat energy into steam to drive the generator to generate electricity, and transmit the generated low-temperature flue gas to the flue gas purification module for emission treatment;

[0011] Ash sorting module: connected to the staged combustion module, used to receive and sort the ash after combustion, extract the usable micro-particles from the sorted ash for subsequent production of building materials or road filling materials, and transport the remaining ash after sorting to a safe treatment area;

[0012] Flue gas purification module: connected to the heat recovery and power generation module, used to receive low-temperature flue gas and purify it, remove pollutants in the flue gas to ensure that emissions meet environmental protection standards. The purification treatment includes multi-stage dust removal, desulfurization and denitrification.

[0013] Optionally, the sludge composition monitoring module includes a data acquisition unit, a data processing unit and a data transmission unit; wherein:

[0014] Data collection unit: including organic matter detection sensor, humidity sensor and calorific value detection sensor, which are used to collect organic matter content, moisture content and calorific value data of sludge respectively;

[0015] Data processing unit: used to receive the organic matter content, moisture content and calorific value data collected by the data collection unit, and calibrate and format the received data;

[0016] Data transmission unit: used to transmit the standardized data generated by the data processing unit to the fuel ratio adjustment module to provide real-time parameters of sludge components.

[0017] Optionally, the fuel ratio adjustment module includes a data receiving unit, a ratio calculation unit and a mixed feeding unit; wherein:

[0018] Data receiving unit: used to receive the sludge calorific value data transmitted by the sludge component monitoring module, and transmit the received calorific value data to the proportion calculation unit to provide real-time parameters of the sludge components;

[0019] Ratio calculation unit: connected to the data receiving unit, used to automatically calculate the ratio of sludge and auxiliary fuel based on the received sludge calorific value data through a preset calorific value balance formula. The specific calculation formula is:

[0020] Where R represents the mass ratio of sludge to auxiliary fuel; Q 目标 The combustion target calorific value preset by the system; Q 污泥 is the actual calorific value of the sludge, provided by the data receiving unit; Q 辅燃料 The actual calorific value of the auxiliary fuel;

[0021] Mixing and feeding unit: connected with the proportion calculation unit, used to receive the calculation result of the proportion calculation unit, add the sludge and auxiliary fuel into the mixing silo in proportion according to the calculated mass ratio, generate a fuel mixture, and send the fuel mixture to the drying and gasification module.

[0022] Optionally, the drying and gasification module includes a waste heat drying unit and a gasification unit; wherein:

[0023] Waste heat drying unit: used to receive the fuel mixture transmitted by the fuel ratio adjustment module, and use the high-temperature flue gas generated by the incinerator to dry the fuel mixture, so that the water in the fuel mixture evaporates by heat, thereby reducing the water content of the sludge;

[0024] Gasification unit: connected to the waste heat drying unit, used to receive the dried fuel mixture and convert part of the organic matter in the mixture into combustible gas by controlling the gasification temperature. The gasification unit includes a gasifier, which is used to heat the fuel mixture at a predetermined temperature to cause the organic matter therein to undergo thermal cracking reaction to generate combustible gas, and output the generated combustible gas and solid residue to the staged combustion module.

[0025] Optionally, the waste heat drying unit includes:

[0026] Smoke guiding subunit: including a guide pipe and a regulating valve, wherein the guide pipe is used to convey high-temperature smoke and accurately guide it into the drying chamber of the heat exchange subunit; the regulating valve is used to regulate the flow of smoke entering the drying chamber to control the smoke temperature and drying rate;

[0027] Heat exchange subunit: connected to the flue gas guiding subunit, used to transfer the heat in the high-temperature flue gas to the fuel mixture and dry the fuel mixture to evaporate the water in the fuel mixture; assuming that the heat required in the drying process is Q, the formula is: Q = m 水 ×L+m 水 ×c 水 ×ΔT, where Q is the total heat required for drying the fuel mixture; m 水 is the mass of water in the fuel mixture; L is the latent heat of vaporization of water, which means the heat required for water to transform from liquid to gas; c 水 is the specific heat capacity of water, which indicates the amount of heat required to raise the temperature of water; ΔT is the temperature rise of water;

[0028] Moisture emission subunit: connected to the heat exchange subunit, used to collect and discharge the moisture generated during the drying process, and guide the moisture out of the drying chamber through the exhaust pipe. Assuming the exhaust speed is v, the calculation formula is: Where v is the moisture emission rate; ρ 湿气 is the density of moisture; cmoisture is the specific heat of moisture; ΔT is the temperature change of moisture.

[0029] Optionally, the staged combustion module includes a fuel input unit, a staged combustion unit and an oxygen supply control unit; wherein:

[0030] Fuel input unit: used to receive the combustible gas and solid residue transmitted by the drying and gasification module, and input them into different combustion stages of the staged combustion unit in a preset order;

[0031] Staged combustion unit: includes three combustion sections, namely, primary combustion section, intermediate combustion section and final combustion section; the primary combustion section is used to preheat the fuel for combustion; the intermediate combustion section is used to heat the fuel and start combustion of part of the solid residue to generate high-temperature flue gas; the final combustion section is used to achieve complete combustion of the solid residue to ensure complete oxidation of all combustible components in the fuel;

[0032] Oxygen supply control unit: connected to the staged combustion unit, used to control the oxygen supply in stages according to the demand of the combustion stage. The oxygen supply control unit includes multiple independent oxygen supply pipelines and adjustable valves. By controlling the oxygen supply amount of each combustion stage, it ensures that the fuel burns at an appropriate oxygen content; the oxygen supply amount is calculated based on the combustion stage temperature and the oxygen demand of the remaining fuel. The calculation formula is: Among them, O i represents the oxygen supply of the i-th combustion stage; H i is the combustion heat load of the combustion section; Q i is the combustion calorific value of the fuel in this section; η i For combustion efficiency.

[0033] Optionally, the heat energy recovery and power generation module includes a flue gas heat exchange unit, a steam generation unit and a smoke exhaust output unit; wherein:

[0034] Flue gas heat exchange unit: used to receive the high-temperature flue gas transmitted by the staged combustion module and transfer the heat of the high-temperature flue gas to the steam generation unit; heat is transferred through the heat exchanger, and the high-temperature flue gas in the heat exchanger flows through the heat exchange pipe, so that the water in the pipe absorbs heat and heats up, providing a stable heat source for subsequent steam generation;

[0035] Steam generation unit: connected to the flue gas heat exchange unit, used to receive the water heated by the heat exchanger and convert the heated water into high-temperature and high-pressure steam. The total heat required to generate steam is set to Q, and the formula is: Q 蒸汽 =M 水 ×C 液 ×ΔT 水 +M 水 ×H 汽化 , where Q steam represents the total heat required to generate steam; M 水 Indicates the quality of water entering the steam generation unit; C 液 ΔT represents the specific heat capacity of liquid water, that is, the amount of heat required for water to rise one degree; 水 Indicates the temperature change of water from the initial temperature to the boiling point; H 汽化 It represents the latent heat of vaporization of water, that is, the heat required for water to transform from liquid to gas. Water is heated to boiling and vaporized into steam. The steam is transported to the generator set through pipelines to drive the generator to convert heat energy into electrical energy.

[0036] Smoke exhaust output unit: connected to the flue gas heat exchange unit, used to guide the low-temperature flue gas after heat exchange and cooling to the flue gas purification module.

[0037] Optionally, the ash sorting module includes an ash receiving unit, a particle separation unit and a residue processing unit; wherein:

[0038] Ash receiving unit: used to receive the ash generated after the staged combustion module is burned, and evenly transport the ash to the particle separation unit; the ash receiving unit is equipped with a conveyor belt and a feed control device to ensure that the ash does not accumulate during the transportation process and the feed flow rate is uniform, providing a stable ash flow for subsequent separation processing;

[0039] Particle separation unit: connected to the ash receiving unit, used to separate usable micro-particles from the ash. The particle separation unit includes a vibrating screen and a magnetic separation device. The vibrating screen is used to screen the ash and extract micro-particles with a particle size that meets the requirements by controlling the size of the sieve holes. The magnetic separation device is used to separate and extract micro-particles containing iron or magnetic components in the screened ash.

[0040] Residue treatment unit: connected to the particle separation unit, used to receive the remaining ash after particle separation, and transport the remaining ash to the safe treatment area through a conveying device for subsequent treatment.

[0041] Optionally, the particle separation unit comprises:

[0042] Sieve hole setting: Set the sieve hole diameter D according to the particle size requirements of the target microparticles 直径 , so that it is smaller than the maximum allowable particle size D of the target particles 目标 , to ensure that the particle size of the sieve meets the requirements, that is, D 直径 ≤D 直径 ;

[0043] Vibration separation: The ash particles are moved on the screen surface through mechanical vibration. The micro particles smaller than the diameter of the screen hole fall through the screen hole to form the undersize; the particles larger than the screen hole remain on the screen surface and are sent to the residue treatment unit for treatment;

[0044] Magnetic field strength setting: The magnetic field strength H is set according to the magnetic strength of iron or other magnetic components in the microparticles. The magnetic field strength setting formula is: Wherein, H represents the magnetic field strength of the magnetic separation equipment; F 磁 represents the magnetic attraction of the microparticle; μ0 represents the magnetic permeability constant; χ represents the magnetic susceptibility of the microparticle; V represents the volume of the microparticle;

[0045] Magnetic separation: Under the set magnetic field strength, microparticles containing magnetic components are attracted by magnetic force and captured in the magnetic collection area of ​​the magnetic separation equipment; non-magnetic microparticles continue to be discharged through the discharge port of the equipment to form microparticle products that can eventually be used.

[0046] Optionally, the flue gas purification module includes a multi-stage dust removal unit, a desulfurization unit and a denitrification unit; wherein:

[0047] Multi-stage dust removal unit: used to remove particulate pollutants in low-temperature flue gas, the multi-stage dust removal unit includes a cyclone dust collector and a bag dust collector; the low-temperature flue gas first enters the cyclone dust collector, and the larger particles are settled into the collection tank through the centrifugal force to preliminarily remove the large particle pollutants; then the flue gas that has passed the cyclone dust collection enters the bag dust collector, and the fine particles in the flue gas are captured and accumulated on the surface of the bag.

[0048] Desulfurization unit: connected to the multi-stage dust removal unit, used to remove sulfur dioxide from the flue gas. The desulfurization unit adopts a wet desulfurization tower. After the flue gas enters the wet desulfurization tower, the desulfurization absorption liquid is atomized through a nozzle and contacts the flue gas. The alkaline substances contained in the absorption liquid react with sulfur dioxide to form sulfite. After the sulfur dioxide and the alkaline substances fully react, the generated sulfite precipitate is collected and discharged;

[0049] Denitrification unit: connected to the desulfurization unit, used to remove nitrogen oxides in the flue gas. The denitrification unit adopts the selective catalytic reduction method. In the SCR reactor, ammonia is sprayed into the flue gas as a reducing agent, and nitrogen oxides and ammonia undergo a reduction reaction on the catalyst surface; nitrogen oxides are reduced to harmless nitrogen and water under the action of the catalyst, and the flue gas after removal is discharged through the exhaust pipe to ensure that the exhaust gas meets environmental protection standards.

[0050] Beneficial effects of the present invention:

[0051] The present invention adopts intelligent fuel ratio adjustment and staged combustion control technology, so that low calorific value sludge can automatically adapt to component fluctuations during the incineration process, realizes precise adjustment and stable combustion of the fuel, and significantly improves the combustion efficiency. By intelligently monitoring the sludge composition and dynamically adjusting the fuel ratio, it not only reduces the consumption of auxiliary fuel, but also effectively reduces the combustion instability problem caused by high water content sludge, so that the system can continuously maintain the optimal combustion state.

[0052] The present invention converts the high-temperature flue gas generated by incineration into steam for power generation by utilizing waste heat recovery technology, thereby realizing efficient reuse of thermal energy, and gradually removes particulate matter, sulfur dioxide and nitrogen oxides in the flue gas through multi-stage flue gas purification technology to ensure that emissions meet standards. This design greatly improves the energy utilization rate and environmental performance of the system, and realizes the harmless, reduced and resource-based treatment of low calorific value sludge. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings in the following description are only for the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0054] Figure 1 A schematic diagram of a circulating fluidized bed boiler system for burning sludge with low calorific value according to an embodiment of the present invention;

[0055] Figure 2 Schematic diagram of a drying and gasification module according to an embodiment of the present invention. DETAILED DESCRIPTION

[0056] The present invention is described in detail below in conjunction with the accompanying drawings and specific embodiments. At the same time, it is explained here that in order to make the embodiments more detailed, the following embodiments are the best and preferred embodiments, and those skilled in the art may also adopt other alternatives to implement some known technologies; and the accompanying drawings are only for more specific description of the embodiments, and are not intended to specifically limit the present invention.

[0057] It should be noted that the references to "one embodiment", "an embodiment", "an exemplary embodiment", "some embodiments" and the like in the specification indicate that the embodiments described may include specific features, structures or characteristics, but not every embodiment may include the specific features, structures or characteristics. In addition, when a specific feature, structure or characteristic is described in conjunction with an embodiment, it should be within the knowledge of a person skilled in the art to implement such feature, structure or characteristic in conjunction with other embodiments (whether or not explicitly described).

[0058] In general, a term can be understood, at least in part, from its use in context. For example, depending, at least in part, on the context, the term "one or more" as used herein can be used to describe any feature, structure, or characteristic in the singular sense, or can be used to describe a combination of features, structures, or characteristics in the plural sense. Additionally, the term "based on" can be understood as not necessarily intended to convey an exclusive set of factors, but can instead, depending, at least in part, on the context, allow for the presence of other factors that are not necessarily explicitly described.

[0059] like Figure 1-Figure 2 As shown, a low calorific value sludge incineration circulating fluidized bed boiler system includes a sludge composition monitoring module, a fuel ratio adjustment module, a drying and gasification module, a staged combustion module, a heat recovery and power generation module, an ash sorting module and a flue gas purification module; wherein:

[0060] Sludge composition monitoring module: used to collect data on organic matter content, moisture content and calorific value of sludge, and transmit the collected data to the fuel ratio adjustment module to provide real-time parameters of sludge composition;

[0061] Fuel ratio adjustment module: connected to the sludge composition monitoring module, used to receive the calorific value data of the sludge, and automatically adjust the ratio of the sludge and the auxiliary fuel based on the calorific value data to generate a fuel mixture, and send the fuel mixture to the drying and gasification module to maintain a suitable furnace temperature and combustion conditions;

[0062] Drying and gasification module: connected to the fuel ratio adjustment module, used to receive the fuel mixture and use the waste heat of the incinerator to dry it to reduce the moisture content of the sludge; at the same time, part of the organic matter is converted into combustible gas through gasification, and the generated combustible gas and solid residue are transmitted to the staged combustion module to improve the combustion efficiency;

[0063] Staged combustion module: connected to the drying and gasification module, used to receive combustible gas and solid residue, and perform staged oxygen supply control in different combustion stages to achieve complete combustion of the fuel; this module adjusts the temperature and oxygen content of different combustion stages to keep the fuel in a suitable combustion state at each stage, and transmits the high-temperature flue gas generated by combustion to the heat recovery and power generation module;

[0064] Heat recovery and power generation module: connected to the staged combustion module, used to receive high-temperature flue gas and recover heat from it, convert heat energy into steam to drive the generator to generate electricity, and transmit the generated low-temperature flue gas to the flue gas purification module for emission treatment;

[0065] Ash sorting module: connected to the staged combustion module, used to receive and sort the ash after combustion, extract the usable micro-particles from the sorted ash for subsequent production of building materials or road filling materials, and transport the remaining ash after sorting to a safe treatment area;

[0066] Flue gas purification module: connected to the heat recovery and power generation module, used to receive low-temperature flue gas and purify it, remove pollutants in the flue gas to ensure that emissions meet environmental standards. The purification process includes multi-stage dust removal, desulfurization and denitrification.

[0067] The sludge composition monitoring module includes a data acquisition unit, a data processing unit and a data transmission unit; wherein:

[0068] Data collection unit: including organic matter detection sensor, humidity sensor and calorific value detection sensor, which are used to collect organic matter content, moisture content and calorific value data of sludge respectively to ensure the integrity of collected data;

[0069] The specific collection principles are as follows:

[0070] The organic matter detection sensor detects the content of organic matter in sludge through infrared spectroscopy. By using an infrared light source to irradiate the sludge sample, the receiving sensor captures the sample's absorption rate of infrared light of a specific wavelength and calculates the proportion of organic matter in the sludge; the formula is: Among them, A λ is the absorbance of the sludge sample at a specific wavelength λ of infrared light; ε is the molar absorption coefficient of organic matter at this wavelength, which indicates the absorption capacity of organic matter at a specific concentration; b is the optical path length, i.e., the distance that infrared light passes through in the sludge sample. This formula calculates the concentration of organic matter based on the infrared light absorption of the sample. By comparing the difference between the absorbance and the reference absorbance, combined with the molar absorption coefficient and the optical path length, the proportion of organic matter in the sludge is obtained.

[0071] The humidity sensor detects the moisture content of the sludge through capacitive measurement. It uses the characteristic that the capacitance of the sludge sample changes with humidity to measure the moisture content in the sludge to ensure the accuracy of the sludge moisture content data.

[0072] The calorific value detection sensor detects the calorific value of sludge by thermal conductivity method, uses thermal conductivity to detect the heat conduction rate of sludge sample at a specific temperature, and calculates the actual calorific value of sludge; the specific calculation formula is as follows: Where Q represents the actual calorific value of the sludge (in J / g); k is the thermal conductivity of the sludge sample (W / m·K), which represents the ability of the sludge to conduct heat under a unit temperature difference; A is the cross-sectional area of ​​the sample (m 2 ) ; ΔT is the temperature difference (k), which indicates the temperature change at both ends of the sample; d is the thickness of the sample (m). This formula calculates the calorific value of the sludge under specific temperature difference conditions through thermal conductivity, temperature difference and geometric parameters of the sample to reflect its combustibility and provide a basis for subsequent fuel ratio adjustment.

[0073] Data processing unit: used to receive the organic matter content, moisture content and calorific value data collected by the data collection unit, and calibrate and format the received data to generate standardized data suitable for subsequent transmission, so that each data maintains a unified accuracy requirement and numerical standard;

[0074] Data transmission unit: used to transmit the standardized data generated by the data processing unit to the fuel ratio adjustment module to provide real-time parameters of the sludge composition, ensuring that the fuel ratio adjustment module makes accurate ratio adjustments based on the current composition data of the sludge; through the configuration of the above-mentioned sludge composition monitoring module, the system can efficiently and accurately obtain the organic matter content, moisture content and calorific value data of the sludge, and provide real-time and accurate composition data support for the fuel ratio adjustment module, thereby improving the combustion stability and efficiency of the system when processing low calorific value sludge.

[0075] The fuel ratio adjustment module includes a data receiving unit, a ratio calculation unit and a mixed feeding unit; wherein:

[0076] Data receiving unit: used to receive the sludge calorific value data transmitted by the sludge component monitoring module, and transmit the received calorific value data to the proportion calculation unit to provide real-time parameters of the sludge components;

[0077] Ratio calculation unit: connected to the data receiving unit, used to automatically calculate the ratio of sludge and auxiliary fuel based on the received sludge calorific value data through a preset calorific value balance formula. The specific calculation formula is:

[0078] Where R represents the mass ratio of sludge to auxiliary fuel; Q 目标 The combustion target calorific value preset by the system; Q 污泥 is the actual calorific value of the sludge, provided by the data receiving unit; Q 辅燃料 is the actual calorific value of the auxiliary fuel. This formula adjusts the ratio of sludge to auxiliary fuel so that the generated fuel mixture meets the combustion target calorific value set by the system to ensure the stability of the calorific value during the combustion process.

[0079] Mixing feeding unit: connected to the ratio calculation unit, used to receive the calculation results of the ratio calculation unit, add sludge and auxiliary fuel into the mixing bin in proportion according to the calculated mass ratio, generate a fuel mixture, and send the fuel mixture to the drying and gasification module; through the configuration of the above-mentioned fuel ratio adjustment module, automatic ratio adjustment of sludge and auxiliary fuel is realized, and the generated fuel mixture meets the target calorific value requirements of the system combustion, effectively improving the combustion efficiency of low calorific value sludge and the stability of the system.

[0080] The drying and gasification module includes a waste heat drying unit and a gasification unit; wherein:

[0081] Waste heat drying unit: used to receive the fuel mixture transmitted by the fuel ratio adjustment module, and use the high-temperature flue gas generated by the incinerator to dry the fuel mixture, so that the water in the fuel mixture evaporates by heat, thereby reducing the moisture content of the sludge and improving the combustibility of the fuel mixture;

[0082] Gasification unit: connected to the waste heat drying unit, used to receive the dried fuel mixture and convert part of the organic matter in the mixture into combustible gas by controlling the gasification temperature. The gasification unit includes a gasifier, which is used to heat the fuel mixture at a predetermined temperature to cause the organic matter therein to undergo thermal cracking reaction to generate combustible gas, and output the generated combustible gas and solid residue to the staged combustion module together; through the configuration of the above-mentioned drying and gasification modules, the water in the fuel mixture is fully evaporated, and part of the organic matter is converted into combustible gas through the gasification process, providing the staged combustion module with fuel with higher combustibility, thereby enhancing the thermal energy utilization efficiency of the combustion and the stability of the system.

[0083] The waste heat drying unit includes:

[0084] Smoke guide subunit: It includes a guide pipe and a regulating valve. The guide pipe is used to transport high-temperature smoke and accurately guide it into the drying chamber of the heat exchange subunit to ensure the stability of the smoke flow path; the regulating valve is used to regulate the smoke flow entering the drying chamber to control the smoke temperature and drying rate, ensuring the heat supply of the drying process is stable and meeting the required drying conditions;

[0085] Heat exchange subunit: connected to the flue gas guiding subunit, used to transfer the heat in the high-temperature flue gas to the fuel mixture and dry the fuel mixture to evaporate the water in the fuel mixture; assuming that the heat required in the drying process is Q, the formula is: Q = m 水 ×L+m 水 ×c 水 ×ΔT, where Q is the total heat required for drying the fuel mixture (in J); m 水is the mass of water in the fuel mixture (in kg); L is the latent heat of vaporization of water (in J / kg), which indicates the heat required to convert water from liquid to gas; c 水 is the specific heat capacity of water (in J / (kg℃), indicating the amount of heat required to raise the temperature of water; ΔT is the temperature rise of water (in ℃);

[0086] Moisture emission subunit: connected to the heat exchange subunit, used to collect and discharge moisture generated during the drying process, and to guide the moisture out of the drying chamber through the exhaust pipe to prevent moisture accumulation from affecting the drying effect. Assuming the exhaust speed is v, the calculation formula is: Where, v is the moisture emission velocity (in m / s); ρ 湿气 is the density of moisture (in kg / m 3 ); c moisture is the specific heat capacity of moisture, in units of J / (kg·℃); ΔT is the temperature variation of moisture (in units of ℃); through the step-by-step configuration of the above-mentioned waste heat drying sub-units, the water in the fuel mixture can be fully evaporated, providing a fuel state with a suitable water content for subsequent gasification treatment, thereby significantly improving the thermal energy utilization rate and combustion efficiency of the system.

[0087] The staged combustion module includes a fuel input unit, a staged combustion unit and an oxygen supply control unit; wherein:

[0088] Fuel input unit: used to receive the combustible gas and solid residue transmitted by the drying and gasification module, and input them into different combustion sections of the staged combustion unit in a preset order to ensure uniform supply of fuel in each combustion section;

[0089] Staged combustion unit: It includes three combustion sections, namely the primary combustion section, the intermediate combustion section and the final combustion section. The primary combustion section is used to preheat the fuel and mainly burn the combustible gas to achieve the initial temperature increase effect. The intermediate combustion section is used to heat the fuel and start the combustion of some solid residues to generate high-temperature flue gas. The final combustion section is used to achieve complete combustion of solid residues and ensure the complete oxidation of all combustible components in the fuel. The staged combustion design controls the combustion efficiency of each combustion section by gradually increasing the combustion temperature.

[0090] Oxygen supply control unit: connected to the staged combustion unit, used to control the oxygen supply in stages according to the demand of the combustion stage. The oxygen supply control unit includes multiple independent oxygen supply pipelines and adjustable valves. By controlling the oxygen supply of each combustion stage, it ensures that the fuel burns at an appropriate oxygen content; the oxygen supply is calculated based on the combustion stage temperature and the oxygen demand of the remaining fuel. The calculation formula is: Among them, O i Indicates the oxygen supply of the i-th combustion stage (in m 3 / h); H iis the combustion heat load of the combustion section (in J); Q i The combustion heat value of the fuel in this section (in J / m 3 );η i For combustion efficiency; the oxygen supply control unit automatically adjusts the oxygen supply according to the oxygen demand and heat load of each combustion section, so that each combustion section has the best combustion conditions, realizes the step-by-step burnout of the fuel, and ensures complete combustion; through the configuration of the above-mentioned segmented combustion module, the combustible gas and solid residue enter the different combustion sections in sequence, realizes complete combustion step by step, significantly improves the combustion efficiency and ensures the complete oxidation of the fuel, providing the system with stable and efficient heat energy output.

[0091] The heat recovery and power generation module includes a flue gas heat exchange unit, a steam generation unit and a flue gas output unit; wherein:

[0092] Flue gas heat exchange unit: used to receive the high-temperature flue gas transmitted by the staged combustion module and transfer the heat of the high-temperature flue gas to the steam generation unit; heat is transferred through the heat exchanger, and the high-temperature flue gas in the heat exchanger flows through the heat exchange pipe, so that the water in the pipe absorbs heat and heats up, providing a stable heat source for subsequent steam generation; in this process, the temperature of the high-temperature flue gas gradually decreases, preparing for transmission to the exhaust output unit;

[0093] Steam generation unit: connected to the flue gas heat exchange unit, used to receive the water heated by the heat exchanger and convert the heated water into high-temperature and high-pressure steam. The total heat required to generate steam is set to Q, and the formula is: Q 蒸汽 =M 水 ×C 液 ×ΔT 水 +M 水 ×H 汽化 , where Q steam represents the total heat required to generate steam (in J); M 水 Indicates the mass of water entering the steam generating unit (in kg); C 液 It represents the specific heat capacity of liquid water (in J / (kg·℃)), that is, the amount of heat required for water to rise one degree; ΔT 水 Indicates the temperature change of water from the initial temperature to the boiling point (in °C); H 汽化 It represents the latent heat of vaporization of water, that is, the heat required to convert water from liquid to gas; this formula is used to calculate the total heat requirement for converting water into steam. The steam generation unit heats water to boiling and vaporizes it into steam under the heat source provided by the heat exchanger. The steam is transported to the generator set through a pipeline to drive the generator to convert thermal energy into electrical energy.

[0094] Smoke exhaust output unit: connected to the flue gas heat exchange unit, used to guide the low-temperature flue gas after heat exchange and cooling to the flue gas purification module; this unit stably transports the low-temperature flue gas to the flue gas purification module through the smoke exhaust pipe, ensuring that the flue gas is fully purified before discharge; through the configuration of the above-mentioned heat energy recovery and power generation modules, the heat of the high-temperature flue gas is fully recovered in the flue gas heat exchange unit for steam generation, and the steam drives the generator to achieve electrical energy output, while the low-temperature flue gas is transported to the flue gas purification module through the smoke exhaust output unit, realizing efficient utilization of the system's waste heat and environmentally friendly emissions.

[0095] The ash sorting module includes an ash receiving unit, a particle separation unit and a residue processing unit; wherein:

[0096] Ash receiving unit: used to receive the ash generated after the staged combustion module is burned, and evenly transport the ash to the particle separation unit; the ash receiving unit is equipped with a conveyor belt and a feed control device to ensure that the ash does not accumulate during the transportation process and the feed flow rate is uniform, providing a stable ash flow for subsequent separation processing;

[0097] Particle separation unit: connected to the ash receiving unit, used to separate usable micro-particles from the ash. The particle separation unit includes a vibrating screen and a magnetic separation device. The vibrating screen is used to screen the ash and extract micro-particles with particle sizes that meet the requirements by controlling the size of the sieve holes; the magnetic separation device is used to separate and extract micro-particles containing iron or magnetic components in the screened ash, so that the obtained micro-particles meet the requirements for use as building materials or road filling materials;

[0098] Residue treatment unit: connected to the particle separation unit, used to receive the remaining ash after particle separation, and transport the remaining ash to a safe treatment area through a conveyor for subsequent treatment. The unit can select safe landfill, solidification treatment or other harmless treatment methods according to the composition of the ash to ensure the environmental friendliness of the residue; through the configuration of the above-mentioned ash sorting module, the ash after combustion is sorted into micro-particles that meet the particle size and magnetic requirements for subsequent use as building materials or road filling materials; and the remaining ash is safely transported to a designated area for harmless treatment, realizing the resource utilization and environmentally friendly disposal of the ash.

[0099] The particle separation unit includes:

[0100] Sieve hole setting: Set the sieve hole diameter D according to the particle size requirements of the target microparticles 直径 , so that it is smaller than the maximum allowable particle size D of the target particles 目标 , to ensure that the particle size of the sieve meets the requirements, that is, D 直径 ≤D 直径 ;

[0101] Vibration separation: The ash particles are moved on the screen surface through mechanical vibration. The micro particles smaller than the diameter of the screen hole fall through the screen hole to form the undersize; the particles larger than the screen hole remain on the screen surface and are sent to the residue treatment unit for treatment;

[0102] Magnetic field strength setting: The magnetic field strength H is set according to the magnetic strength of iron or other magnetic components in the microparticles. The magnetic field strength setting formula is: Wherein, H represents the magnetic field strength of the magnetic separation equipment (in A / m); F 磁 represents the magnetic attraction of the microparticle (in N); μ0 represents the magnetic permeability constant (in T·m / A); χ represents the magnetic susceptibility of the microparticle; V represents the volume of the microparticle (in m 3 );

[0103] Magnetic separation: Under the set magnetic field strength, microparticles containing magnetic components are attracted by magnetic force and captured in the magnetic collection area of ​​the magnetic separation equipment; non-magnetic microparticles continue to be discharged through the discharge port of the equipment to form microparticle products that can finally be used; through the configuration of the above-mentioned particle separation unit, the vibrating screen can effectively screen the ash according to the particle size requirements, and the magnetic separation equipment can further separate the magnetic component microparticles, thereby obtaining microparticles with particle size and composition that meet the requirements for subsequent use as construction materials or road filling materials, thereby achieving efficient utilization of resources.

[0104] The flue gas purification module includes a multi-stage dust removal unit, a desulfurization unit and a denitrification unit; among which:

[0105] Multi-stage dust removal unit: used to remove particulate pollutants in low-temperature flue gas. The multi-stage dust removal unit includes a cyclone dust collector and a bag dust collector. The low-temperature flue gas first enters the cyclone dust collector, where the larger particles are settled into the collection tank through centrifugal force to preliminarily remove the large particle pollutants. The flue gas that has passed the cyclone dust removal then enters the bag dust collector, where the fine particles in the flue gas are captured and accumulated on the surface of the bag, and the purified gas is discharged to the next processing unit to ensure that the particle removal effect meets the emission requirements.

[0106] Desulfurization unit: connected to the multi-stage dust removal unit, used to remove sulfur dioxide (SO2) from the flue gas. The desulfurization unit adopts a wet desulfurization tower. After the flue gas enters the wet desulfurization tower, the desulfurization absorption liquid is atomized through a nozzle and contacts the flue gas. The absorption liquid contains alkaline substances (such as sodium hydroxide solution) that react with sulfur dioxide to form sulfite. After sulfur dioxide and alkaline substances fully react, the generated sulfite precipitate is collected and discharged, realizing the efficient removal of sulfur dioxide. The purified flue gas enters the denitrification unit;

[0107] Denitrification unit: connected to the desulfurization unit to remove nitrogen oxides (NO x), the denitrification unit adopts the selective catalytic reduction (SCR) method. In the SCR reactor, ammonia (NH3) is sprayed into the flue gas as a reducing agent, and nitrogen oxides and ammonia undergo a reduction reaction on the catalyst surface; nitrogen oxides are reduced to harmless nitrogen (N2) and water (H2O) under the action of the catalyst, and the flue gas after removal is discharged through the exhaust pipe to ensure that the exhaust gas meets environmental protection standards; through the multi-stage purification design of the above-mentioned flue gas purification module, the low-temperature flue gas is gradually removed from particulate matter, sulfur dioxide and nitrogen oxides in the multi-stage dust removal unit, desulfurization unit and denitrification unit, ensuring that the flue gas purification effect meets environmental protection emission standards and avoids the emission of atmospheric pollutants.

[0108] The present invention covers any substitution, modification, equivalent method and scheme made on the essence and scope of the present invention. In order to make the public have a thorough understanding of the present invention, specific details are described in detail in the following preferred embodiments of the present invention, but those skilled in the art can fully understand the present invention without the description of these details. In addition, in order to avoid unnecessary confusion about the essence of the present invention, well-known methods, processes, procedures, components and circuits are not described in detail.

[0109] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A low calorific value sludge incineration circulating fluidized bed boiler system, characterized in that: It includes sludge composition monitoring module, fuel ratio adjustment module, drying and gasification module, staged combustion module, heat recovery and power generation module, ash sorting module and flue gas purification module; among which: Sludge composition monitoring module: used to collect data on organic matter content, moisture content and calorific value of sludge, and transmit the collected data to the fuel ratio adjustment module to provide real-time parameters of sludge composition; Fuel ratio adjustment module: connected to the sludge composition monitoring module, used to receive the calorific value data of the sludge, and automatically adjust the ratio of the sludge and the auxiliary fuel based on the calorific value data to generate a fuel mixture, and send the fuel mixture to the drying and gasification module; Drying and gasification module: connected to the fuel ratio adjustment module, used to receive the fuel mixture and use the waste heat of the incinerator to dry it to reduce the moisture content of the sludge; at the same time, part of the organic matter is converted into combustible gas through gasification, and the generated combustible gas and solid residue are transmitted to the staged combustion module; Staged combustion module: connected to the drying and gasification module, used to receive combustible gas and solid residue, and perform staged oxygen supply control in different combustion stages to achieve complete combustion of the fuel, and transmit the high-temperature flue gas generated by combustion to the heat recovery and power generation module; Heat recovery and power generation module: connected to the staged combustion module, used to receive high-temperature flue gas and recover heat from it, convert heat energy into steam to drive the generator to generate electricity, and transmit the generated low-temperature flue gas to the flue gas purification module for emission treatment; Ash sorting module: connected to the staged combustion module, used to receive and sort the ash after combustion, extract the usable micro-particles from the sorted ash for subsequent production of building materials or road filling materials, and transport the remaining ash after sorting to a safe treatment area; Flue gas purification module: connected to the heat recovery and power generation module, used to receive low-temperature flue gas and purify it, remove pollutants in the flue gas to ensure that emissions meet environmental protection standards. The purification treatment includes multi-stage dust removal, desulfurization and denitrification.

2. A low calorific value sludge incineration circulating fluidized bed boiler system according to claim 1, characterized in that: The sludge composition monitoring module includes a data acquisition unit, a data processing unit and a data transmission unit; wherein: Data collection unit: including organic matter detection sensor, humidity sensor and calorific value detection sensor, which are used to collect organic matter content, moisture content and calorific value data of sludge respectively; Data processing unit: used to receive the organic matter content, moisture content and calorific value data collected by the data collection unit, and calibrate and format the received data; Data transmission unit: used to transmit the standardized data generated by the data processing unit to the fuel ratio adjustment module to provide real-time parameters of sludge components.

3. A low calorific value sludge incineration circulating fluidized bed boiler system according to claim 1, characterized in that: The fuel ratio adjustment module includes a data receiving unit, a ratio calculation unit and a mixed feeding unit; wherein: Data receiving unit: used to receive the sludge calorific value data transmitted by the sludge component monitoring module, and transmit the received calorific value data to the proportion calculation unit to provide real-time parameters of the sludge components; Ratio calculation unit: connected to the data receiving unit, used to automatically calculate the ratio of sludge and auxiliary fuel based on the received sludge calorific value data through a preset calorific value balance formula. The specific calculation formula is: Where R represents the mass ratio of sludge to auxiliary fuel; Q 目标 The combustion target calorific value preset by the system; Q 污泥 is the actual calorific value of the sludge, provided by the data receiving unit; Q 辅燃料 The actual calorific value of the auxiliary fuel; Mixing and feeding unit: connected with the proportion calculation unit, used to receive the calculation result of the proportion calculation unit, add the sludge and auxiliary fuel into the mixing silo in proportion according to the calculated mass ratio, generate a fuel mixture, and send the fuel mixture to the drying and gasification module.

4. A low calorific value sludge incineration circulating fluidized bed boiler system according to claim 1, characterized in that: The drying and gasification module includes a waste heat drying unit and a gasification unit; wherein: Waste heat drying unit: used to receive the fuel mixture transmitted by the fuel ratio adjustment module, and use the high-temperature flue gas generated by the incinerator to dry the fuel mixture, so that the water in the fuel mixture evaporates by heat, thereby reducing the water content of the sludge; Gasification unit: connected to the waste heat drying unit, used to receive the dried fuel mixture and convert part of the organic matter in the mixture into combustible gas by controlling the gasification temperature. The gasification unit includes a gasifier, which is used to heat the fuel mixture at a predetermined temperature to cause the organic matter therein to undergo thermal cracking reaction to generate combustible gas, and output the generated combustible gas and solid residue to the staged combustion module.

5. A low calorific value sludge incineration circulating fluidized bed boiler system according to claim 4, characterized in that: The waste heat drying unit comprises: Smoke guiding subunit: including a guide pipe and a regulating valve, wherein the guide pipe is used to convey high-temperature smoke and accurately guide it into the drying chamber of the heat exchange subunit; the regulating valve is used to regulate the flow of smoke entering the drying chamber to control the smoke temperature and drying rate; Heat exchange subunit: connected to the flue gas guiding subunit, used to transfer the heat in the high-temperature flue gas to the fuel mixture and dry the fuel mixture to evaporate the water in the fuel mixture; assuming that the heat required in the drying process is Q, the formula is: Q = m 水 ×L+m 水 ×c 水 ×ΔT, where Q is the total heat required for drying the fuel mixture; m 水 is the mass of water in the fuel mixture; L is the latent heat of vaporization of water, which means the heat required for water to transform from liquid to gas; c 水 is the specific heat capacity of water, which indicates the amount of heat required to raise the temperature of water; ΔT is the temperature rise of water; Moisture emission subunit: connected to the heat exchange subunit, used to collect and discharge the moisture generated during the drying process, and guide the moisture out of the drying chamber through the exhaust pipe. Assuming the exhaust speed is v, the calculation formula is: Where v is the moisture emission rate; ρ 湿气 is the density of moisture; cmoisture is the specific heat of moisture; ΔT is the temperature change of moisture.

6. A low calorific value sludge incineration circulating fluidized bed boiler system according to claim 1, characterized in that: The staged combustion module includes a fuel input unit, a staged combustion unit and an oxygen supply control unit; wherein: Fuel input unit: used to receive the combustible gas and solid residue transmitted by the drying and gasification module, and input them into different combustion stages of the staged combustion unit in a preset order; Staged combustion unit: includes three combustion sections, namely, primary combustion section, intermediate combustion section and final combustion section; the primary combustion section is used to preheat the fuel for combustion; the intermediate combustion section is used to heat the fuel and start combustion of part of the solid residue to generate high-temperature flue gas; the final combustion section is used to achieve complete combustion of the solid residue to ensure complete oxidation of all combustible components in the fuel; Oxygen supply control unit: connected to the staged combustion unit, used to control the oxygen supply in stages according to the demand of the combustion stage. The oxygen supply control unit includes multiple independent oxygen supply pipelines and adjustable valves. By controlling the oxygen supply amount of each combustion stage, it ensures that the fuel burns at an appropriate oxygen content; the oxygen supply amount is calculated based on the combustion stage temperature and the oxygen demand of the remaining fuel. The calculation formula is: Among them, O i represents the oxygen supply of the i-th combustion stage; H i is the combustion heat load of the combustion section; Q i is the combustion calorific value of the fuel in this section; η i For combustion efficiency.

7. A low calorific value sludge incineration circulating fluidized bed boiler system according to claim 1, characterized in that: The heat recovery and power generation module includes a flue gas heat exchange unit, a steam generation unit and a smoke exhaust output unit; wherein: Flue gas heat exchange unit: used to receive the high-temperature flue gas transmitted by the staged combustion module and transfer the heat of the high-temperature flue gas to the steam generation unit; heat is transferred through the heat exchanger, and the high-temperature flue gas in the heat exchanger flows through the heat exchange pipe, so that the water in the pipe absorbs heat and heats up, providing a stable heat source for subsequent steam generation; Steam generation unit: connected to the flue gas heat exchange unit, used to receive the water heated by the heat exchanger and convert the heated water into high-temperature and high-pressure steam. The total heat required to generate steam is set to Q, and the formula is: Q 蒸汽 =M 水 ×C 液 ×ΔT 水 +M 水 ×H 汽化 , where Q steam represents the total heat required to generate steam; M 水 Indicates the quality of water entering the steam generation unit; C 液 ΔT represents the specific heat capacity of liquid water, that is, the amount of heat required for water to rise one degree; 水 Indicates the temperature change of water from the initial temperature to the boiling point; H 汽化 It represents the latent heat of vaporization of water, that is, the heat required for water to transform from liquid to gas. Water is heated to boiling and vaporized into steam. The steam is transported to the generator set through pipelines to drive the generator to convert heat energy into electrical energy. Smoke exhaust output unit: connected to the flue gas heat exchange unit, used to guide the low-temperature flue gas after heat exchange and cooling to the flue gas purification module.

8. The low calorific value sludge incineration circulating fluidized bed boiler system according to claim 1, characterized in that: The ash sorting module includes an ash receiving unit, a particle separation unit and a residue processing unit; wherein: Ash receiving unit: used to receive the ash generated after the staged combustion module is burned, and evenly transport the ash to the particle separation unit; the ash receiving unit is equipped with a conveyor belt and a feed control device to ensure that the ash does not accumulate during the transportation process and the feed flow rate is uniform, providing a stable ash flow for subsequent separation processing; Particle separation unit: connected to the ash receiving unit, used to separate usable micro-particles from the ash. The particle separation unit includes a vibrating screen and a magnetic separation device. The vibrating screen is used to screen the ash and extract micro-particles with a particle size that meets the requirements by controlling the size of the sieve holes. The magnetic separation device is used to separate and extract micro-particles containing iron or magnetic components in the screened ash. Residue treatment unit: connected to the particle separation unit, used to receive the remaining ash after particle separation, and transport the remaining ash to the safe treatment area through a conveying device for subsequent treatment.

9. A low calorific value sludge incineration circulating fluidized bed boiler system according to claim 8, characterized in that: The particle separation unit comprises: Sieve hole setting: Set the sieve hole diameter D according to the particle size requirements of the target microparticles 直径 , so that it is smaller than the maximum allowable particle size D of the target particles 目标 , to ensure that the particle size of the sieve meets the requirements, that is, D 直径 ≤D 直径 ; Vibration separation: The ash particles are moved on the screen surface through mechanical vibration. The micro particles smaller than the diameter of the screen hole fall through the screen hole to form the undersize; the particles larger than the screen hole remain on the screen surface and are sent to the residue treatment unit for treatment; Magnetic field strength setting: The magnetic field strength H is set according to the magnetic strength of iron or other magnetic components in the microparticles. The magnetic field strength setting formula is: Wherein, H represents the magnetic field strength of the magnetic separation equipment; F 磁 represents the magnetic attraction of the microparticle; μ0 represents the magnetic permeability constant; χ represents the magnetic susceptibility of the microparticle; S represents the volume of the microparticle; Magnetic separation: Under the set magnetic field strength, microparticles containing magnetic components are attracted by magnetic force and captured in the magnetic collection area of ​​the magnetic separation equipment; non-magnetic microparticles continue to be discharged through the discharge port of the equipment to form microparticle products that can eventually be used.

10. The low calorific value sludge incineration circulating fluidized bed boiler system according to claim 1, characterized in that: The flue gas purification module includes a multi-stage dust removal unit, a desulfurization unit and a denitrification unit; wherein: Multi-stage dust removal unit: used to remove particulate pollutants in low-temperature flue gas, the multi-stage dust removal unit includes a cyclone dust collector and a bag dust collector; the low-temperature flue gas first enters the cyclone dust collector, and the larger particles are settled into the collection tank through the centrifugal force to preliminarily remove the large particle pollutants; then the flue gas that has passed the cyclone dust collection enters the bag dust collector, and the fine particles in the flue gas are captured and accumulated on the surface of the bag. Desulfurization unit: connected to the multi-stage dust removal unit, used to remove sulfur dioxide from the flue gas. The desulfurization unit adopts a wet desulfurization tower. After the flue gas enters the wet desulfurization tower, the desulfurization absorption liquid is atomized through a nozzle and contacts the flue gas. The alkaline substances contained in the absorption liquid react with sulfur dioxide to form sulfite. After the sulfur dioxide and the alkaline substances fully react, the generated sulfite precipitate is collected and discharged; Denitrification unit: connected to the desulfurization unit, used to remove nitrogen oxides in the flue gas. The denitrification unit adopts the selective catalytic reduction method. In the SCR reactor, ammonia is sprayed into the flue gas as a reducing agent, and nitrogen oxides and ammonia undergo a reduction reaction on the catalyst surface; nitrogen oxides are reduced to harmless nitrogen and water under the action of the catalyst, and the flue gas after removal is discharged through the exhaust pipe to ensure that the exhaust gas meets environmental protection standards.

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