CN214745853U - Heat energy recovery and flue gas purification integrated system of incineration boiler - Google Patents

Abstract

The utility model discloses an incineration boiler heat recovery and flue gas purification integrated system, including boiler island and flue gas island. A flue gas baffle door is arranged between the upper part of the hearth of the boiler island and the convection heat exchange cavity, and a flue gas inlet of the flue gas island is communicated with the hearth at the upstream position of the flue gas baffle door through a flue gas circulating pipeline I; and a flue gas outlet of the flue gas island is connected between the downstream of a flue gas baffle door of the boiler island and the upstream of the convection heat exchange cavity through a flue gas circulation pipeline II. The convection heat exchanger is arranged in the convection heat exchange cavity, the purified flue gas exchanges heat in the convection heat exchange cavity, and the low-temperature flue gas after heat exchange is sent to a chimney through a flue gas pipeline through a draught fan and is discharged to the atmosphere. The utility model discloses thoroughly solved and in burning renewable energy source heat energy comprehensive utilization processes such as life or industrial waste, mud, agriculture and forestry living beings or general solid useless, to wearing and tearing, corruption and the stifled grey problem of boiler afterbody convection heating surface, greatly improved heat exchange efficiency, reduced equipment operation and maintenance cost.

Description

Heat energy recovery and flue gas purification integrated system of incineration boiler

The technical field is as follows:

the utility model relates to a mode such as circulating fluidized bed, grate layer fire boiler burns life or industrial waste, mud, agriculture and forestry living beings or general solid useless, technical field such as the comprehensive recycle of power generation or energy carries out, is the system device with boiler island and flue gas island organic integration, has both guaranteed that the boiler burns safety, stability, high efficiency, can make each item index of flue gas after burning again reach the ultralow emission requirement of standard.

Background art:

at present, boiler islands such as a circulating fluidized bed or a grate-fired furnace are generally adopted for harmless incineration treatment in the technical field of domestic or industrial garbage, sludge, agriculture and forestry biomass or general solid waste (compared with non-renewable fossil fuels such as coal, petroleum and the like, the substances are generally called renewable energy sources and are hereinafter collectively referred to as "renewable energy sources"). The boiler island equipment comprises an incineration boiler body, a water supply system, a smoke and air system, an ash treatment system and the like; the flue gas island equipment comprises a desulfurization system, a denitration system, a dioxin removal system, a flue gas dust removal system and the like, and is mainly used for purifying harmful components (such as SO2, NOX, CO and the like) and dust (mainly comprising human inhalable particles, harmful heavy metals, dioxin and the like) in polluted flue gas discharged by an incineration boiler to reach the national ultra-clean emission index and discharge the atmosphere.

For the incineration power generation of renewable energy sources or the comprehensive utilization of energy sources, a boiler island and a flue gas island are two core process systems of a waste energy-converting factory. How to achieve the organic coordination of the two core process systems is the key.

The traditional flue gas island is generally placed at the downstream of a boiler island, and purified flue gas is sent to a chimney through a boiler induced draft fan to be discharged into the atmosphere. At the moment, harmful flue gas discharged by the boiler island equipment is between 150 ℃ and 220 ℃, and the flue gas purification device is called as a low-temperature flue gas island in the patent term.

The low temperature flue gas island though can also reach the requirement of gas cleaning index to a certain extent, nevertheless to the boiler body, its harmful flue gas that does not process is from direct heat transfer in the convection current heat transfer cavity of furnace, will lead to following several problems:

(1) the wear problem of the convection heating surface of the heat exchanger is that the windward surface of the convection heat exchanger needs to be provided with an anti-wear sheet to reduce the damage to the heat exchange tube bundle, but reduce the convection heat exchange coefficient, influence the heat exchange efficiency and increase the operation and maintenance cost;

(2) the convection heating surface tube bundle of the boiler is easy to have ash blockage, and the surface of the convection heating surface tube bundle is cleaned regularly or irregularly by matching with a corresponding ash cleaning device, so that effective heat exchange can be ensured;

(3) after the boiler body passes through radiation and convection heat transfer, if the boiler exhaust gas temperature is too high can reduce waste heat recovery efficiency, if exhaust gas temperature crosses lowly then can cause the boiler convection heat exchanger tube bank to produce the low temperature corrosion and lead to the accident such as the pipe explosion is revealed.

In summary, there is a need for improvements in conventional flue gas cleaning devices and methods.

The utility model has the following contents:

the utility model aims to make up the defects of the prior art, provides an incineration boiler heat energy recovery and flue gas purification integrated system, breaks through the traditional thinking mode, and influences the heat exchange design concept of the boiler body; meanwhile, the process route transformation of the existing waste energy conversion factory is accelerated, and the process route transformation is a revolutionary technical innovation in the industry.

The utility model discloses a realize through following technical scheme:

an integrated system for recovering heat energy and purifying fume of an incineration boiler comprises a boiler island and a fume island.

A smoke baffle plate door is arranged between the upper part of the hearth of the boiler island and the convection heat exchange cavity; the flue gas inlet of the flue gas island is communicated with the furnace at the upstream position of the flue gas baffle door through a flue gas circulation pipeline I, and the flue gas outlet of the flue gas island is connected between the downstream of the flue gas baffle door of the boiler island and the upstream of the convection heat exchange cavity through a flue gas circulation pipeline II; the convection heat exchanger is arranged in the convection heat exchange cavity, purified flue gas exchanges heat in the convection heat exchange cavity, and low-temperature flue gas after heat exchange is delivered to a chimney through a flue gas pipeline through a draught fan to be discharged to the atmosphere, so that an integrated system for comprehensive heat energy recycling and flue gas purification treatment through an incineration boiler is formed.

The flue gas island comprises a flue gas treatment body, a flue gas circulating pipeline, a dosing device and a circulating fan; the smoke treatment body comprises a clean room, a pollution chamber, a partition plate and a high-temperature-resistant composite filter cylinder, wherein the clean room and the pollution chamber are filtered by the high-temperature-resistant composite filter cylinder and are isolated by the partition plate to be divided into an upper chamber and a lower chamber; the upper port of the high-temperature resistant composite filter cylinder is an opening and is used for discharging clean smoke, the bottom port of the high-temperature resistant composite filter cylinder is closed and is used for blocking polluted smoke, filter holes are distributed in the side wall of the high-temperature resistant composite filter cylinder, dust is filtered through the high-temperature resistant composite filter cylinder, and the high-temperature resistant composite filter cylinder is connected to a fly ash conveying system through a dust falling pipeline; the upper end part of the high-temperature resistant composite filter cylinder is provided with a step which is convenient to clamp, and the partition plate is provided with mounting holes for clamping the high-temperature resistant composite filter cylinder; on the upstream of the flue gas circulation pipeline, a dosing device is arranged on the inlet pipeline of the flue gas treatment body, the dosing device is used for adding chemical agents including but not limited to a desulfurizer, a denitrifier and a dioxin removal agent storage tank, and the bottom of the dosing device is connected with the flue gas circulation pipeline through a control valve; and the smoke circulating system of the smoke island adopts a circulating fan to perform forced ventilation.

The high-temperature resistant composite filter cylinder consists of a high-temperature resistant ceramic filter cylinder and a vanadium-titanium-tungsten catalyst layer coated on the outer surface of the high-temperature resistant ceramic filter cylinder.

The utility model has the advantages that:

1. because the clean flue gas which is discharged after reaching the standard and has no pollution is arranged behind the flue gas baffle door of the boiler body, the convection heat exchange efficiency of the boiler is greatly improved;

2. the abrasion problem of the convection heating surface of the boiler is thoroughly solved, and in the design of the convection heat exchanger, an anti-abrasion sheet is not needed on the windward surface, so that higher flue gas flow velocity can be adopted, the convection heat transfer coefficient is improved, the convection heating surface is reduced, and metal materials are saved;

3. the problem of ash blockage of the convection heating surface of the boiler is thoroughly solved, the convection heat exchanger can adopt a heat exchange tube with a fin expansion heating surface, the space is saved, and in addition, a traditional ash removal device is not needed;

4. the problem of low-temperature corrosion of the convection heating surface of the boiler is thoroughly solved, lower exhaust gas temperature (the lowest exhaust gas temperature can be guaranteed to be below 60 ℃) can be adopted in the design of the boiler, the heat loss of exhaust gas is reduced, the design efficiency of the boiler is improved, and the environmental heat pollution of a power plant is reduced;

5. the phenomenon that a chimney of a power plant emits white smoke is thoroughly eliminated, the haze weather and the gypsum rain are reduced, and the environment protection is facilitated;

6. the dioxin is thoroughly chemically decomposed instead of being physically adsorbed, so that secondary pollution is avoided, and workers are also in a safe environment;

7. the synergistic high-temperature desulfurization and denitrification are adopted, the sewage discharge is zero, the high-temperature operation of equipment is realized, the corrosion of the equipment caused by condensation is avoided, the equipment and the like do not need heat tracing, and the maintenance cost is saved;

8. the flue gas treatment adopts a five-in-one integrated high-temperature flue gas purification process, which is more convenient for the high-efficiency recovery of the flue gas energy.

Description of the drawings:

fig. 1 is a schematic diagram of a boiler island and flue gas island integrated system.

Fig. 2 is a schematic diagram of a smoke island structure.

Fig. 3 is a schematic structural diagram of a high temperature resistant composite filter cartridge.

Reference numerals:

1. a boiler island; 1-1, a hearth; 1-2, a convection heat exchanger; 1-3, a convection heat exchange cavity; 1-4, a flue gas damper door; 2. a flue gas island; 2-1, cleaning room; 2-2, a pollution chamber; 2-3, a partition board; 2-4, high-temperature composite filter cylinders; 2-4-1, high temperature resistant ceramic filter cartridge; 2-4-2, a vanadium-titanium-tungsten catalyst layer; 2-5, a flue gas circulation pipeline; 2-6, a dosing device; 2-7, a circulating fan; 3-1, a flue gas circulation pipeline I; 3-2 flue gas circulation pipeline II; 4. a flue gas duct; 5. an induced draft fan; 6. and (4) a chimney.

The specific implementation mode is as follows:

see the drawings.

An integrated system for recovering heat energy and purifying flue gas of an incineration boiler comprises a boiler island 1 and a flue gas island 2, wherein a flue gas baffle door 1-4 is arranged between the upper part of a hearth 1-1 of the boiler island 1 and a convection heat exchange cavity 1-3, and a flue gas inlet of the flue gas island 2 is communicated with the hearth 1-1 at the upstream position of the flue gas baffle door 1-4 through a flue gas circulating pipeline I3-1; the flue gas outlet of the flue gas island 2 is connected between the downstream of a flue gas baffle door 1-4 of the boiler island 1 and the upstream of a convection heat exchange cavity 1-3 through a flue gas circulating pipeline II 3-2, a convection heat exchanger 1-2 is arranged in the convection heat exchange cavity 1-3, the purified flue gas exchanges heat in the convection heat exchange cavity 1-3, the low-temperature flue gas after heat exchange is sent to a chimney 6 through a flue gas pipeline 4 through an induced draft fan 5 to be exhausted to the atmosphere, and an integrated system for comprehensive heat energy recycling and flue gas purification treatment through an incineration boiler is formed.

Further, the flue gas island 2 comprises a flue gas treatment body, a flue gas circulation pipeline 2-5, a dosing device 2-6 and a circulating fan 2-7, the flue gas treatment body comprises a clean room 2-1, a pollution chamber 2-2, a partition plate 2-3 and a high temperature resistant composite filter cylinder 2-4, the clean room 2-1 and the pollution chamber 2-2 are filtered through the high temperature resistant composite filter cylinder 2-4 and are isolated through the partition plate 2-3 to be divided into an upper chamber and a lower chamber, the upper port of the high temperature resistant composite filter cylinder 2-4 is an opening and is used for discharging clean flue gas, the lower port is closed and is used for isolating polluted flue gas, filter holes are distributed on the side wall of the high temperature resistant composite filter cylinder 2-4, the dust is filtered by the high-temperature resistant composite filter cylinder 2-4 and is connected to a fly ash conveying system by a dust falling pipeline. The high-temperature resistant composite filter cylinder 2-4 consists of a high-temperature resistant ceramic filter cylinder 2-4-1 and a vanadium-titanium-tungsten catalyst layer 2-4-2 coated on the outer surface. The flue gas circulating pipeline 2-5 adopts a circulating fan 2-7 to perform forced ventilation. The upper end part of the high-temperature resistant composite filter cylinder 2-4 is provided with a step which is convenient to clamp, and the partition plate 2-3 is distributed with mounting holes for clamping the high-temperature resistant composite filter cylinder 2-4. The upper reaches of the flue gas circulating pipeline 2-5, the inlet pipeline of the flue gas processing body is provided with a dosing device 2-6, the dosing device 2-6 is used for adding chemical agents including but not limited to a desulfurizer, a denitrifier and a dioxin removal agent storage tank, and the bottom of the dosing device is connected with the flue gas circulating pipeline 2-5 through a control valve.

To the utility model discloses burn boiler heat recovery and gas cleaning integrated system, the boiler island needs the performance assurance on gas island:

1. the treated smoke pollutants meet the national ultra-clean emission requirement;

2. the air leakage rate is not more than 2%;

3. the smoke resistance is about 1300-1600 Pa and cannot exceed 1600 Pa;

4. the temperature of an inlet and an outlet of the treated flue gas is reduced to 20-50 ℃, and the maximum temperature is not more than 50 ℃;

5. the maximum bearing smoke can not be lower than 420 ℃.

The flue gas island only guarantees above-mentioned performance, and incineration boiler heat recovery and gas cleaning integrated system just can reach the utility model discloses a system is optimum.

In the above structure: set up the flue gas damper on the flue gas passageway between boiler body burning furnace room and heat convection device, will pollute the flue gas and take out before the damper, behind the flue gas purification device, clean flue gas up to standard is introduced from behind the flue gas damper again. At the moment, the clean flue gas and the boiler body convection heat exchange device perform sufficient heat exchange, the low-temperature flue gas after heat exchange is led out from the boiler body, and then the low-temperature flue gas is exhausted to the atmosphere through a chimney by a boiler induced draft fan.

The temperature of the flue gas extracted from the middle of the boiler body is between 300 ℃ and 450 ℃, and the flue gas purification device is called as a high-temperature flue gas island in the patent.

Although also there is the case of taking out the high temperature flue gas from the middle of the boiler body to handle at present, but generally only be limited to the denitration of flue gas, the utility model discloses the high temperature flue gas island that indicates includes flue gas desulfurization, denitration, takes off white, gets rid of dioxin, five integrative flue gas purification processes that integrate such as flue gas dust removal.

The utility model discloses, high temperature flue gas island core technical description is as follows:

the high temperature composite filter cartridge is mounted directly to the aperture plate of the dust collector. The product can work in high temperature environment. The composite filter cartridge is constructed of an aluminum silicate ceramic to provide dust filtration efficiency at higher temperatures (relative to conventional cloth bag filter cartridges) and to maintain stable performance over time. The traditional filter cloth has elasticity, expands and deforms when blown against the air, and completely peels off the dust cake, so that the dust is feared to penetrate. The high temperature composite filter cartridge is a rigid filter body, retains the residual dust cake and improves the filtering effect of fine particles. The life span is superior to that of the conventional dust collector (filter bag). The equipment is operated at high temperature, the corrosion of the equipment caused by condensation is avoided, the equipment and the like do not need heat tracing, and the maintenance cost is saved.

In addition, besides high efficiency of flue gas dust removal, the effects of denitration, desulfurization, whitening and dioxin removal are also assisted, and five parts of the flue gas dust removal device can be simultaneously processed and finished in a closed environment under the same temperature working condition.

And (3) synergistic desulfurization: acid gases (SO 2, HCL, HF, etc.) are removed by dry methods using various alkaline agents, such as sodium bicarbonate (NaHCO 3) or slaked lime (Ca (OH) 2). The filter drum dust remover can be regarded as a desulfurization reaction cabin, and a slaked lime filter cake fixed bed is formed outside the filter drum, so that the reaction effect is improved.

And (3) performing synergistic denitration: ammonia or urea is added to remove nitrogen oxides. The catalytic high-temperature composite filter cylinder is characterized in that a layer of vanadium-titanium-tungsten catalyst is laid on the outer side of the filter cylinder and used for reducing nitrogen oxides into nitrogen. The principle of removing nitrogen oxides by adopting a high-temperature composite filter cylinder belongs to an improved Selective Catalytic Reduction (Selective Catalytic Reduction). The catalyst adopts a vanadium-titanium-tungsten system, and the optimal operation temperature is 300-420 ℃ and the maximum temperature is 450 ℃.

And (3) synergistic whitening: the water vapor in the flue gas participates in the whole desulfurization process, and the dry desulfurization is adopted, so that the water vapor in the flue gas participates in the chemical reaction of the desulfurizer and the acid-removing gas, the sewage is zero-emission, and the white feather (white smoke) phenomenon of a chimney is eliminated.

Synergistic decomposition of dioxins: under the action of the vanadium-based catalyst, dioxin and oxygen react and are decomposed into non-toxic or slightly-toxic substances such as CO2, H2O, HCl and the like to be discharged.

Approximate reaction equation for dioxin decomposition:

C12HnCl8-nO2+(9+0.5n)O2=(n-4)H2O+12CO2+(8-n)HCl。

the vanadium-based catalyst is used for chemically decomposing dioxin, while the traditional activated carbon is used for adsorbing dioxin, and the dioxin in the flue gas is only transferred into fly ash and needs to be sent to a hazardous waste treatment plant for fly ash solidification treatment so as to prevent the dioxin from escaping again. The activated carbon is a physical process rather than a chemical decomposition of dioxin, so secondary pollution is inevitable.

In addition, because the clean flue gas does not have low-temperature corrosion to the heat exchange pipe, the flue gas temperature of the incineration boiler can be reduced to the maximum extent, and the aims of saving energy and reducing consumption are fulfilled. In order to avoid low-temperature corrosion, the exhaust gas temperature of the boiler must be higher than the dew point of the exhaust gas, and the exhaust gas temperature is generally controlled to be 150-220 ℃. The utility model discloses a lean on each convection current part rational arrangement heat transfer part to realize the purpose that the boiler ultra-low temperature discharged, exhaust gas temperature can guarantee below 60 ℃, and the maximum recycle of accomplishing the energy.

In the description of the present invention, it should be noted that the terms "upstream" and "downstream" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, which is only for the convenience of describing the present invention and simplifying the description, but does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus, should not be construed as limiting the present invention. Further, " serial numbers 1, 2, 3 … …" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

In the description of the present invention, it should also be noted that, unless expressly stated or limited otherwise, the terms "disposed," "mounted," "connected," and "connected" are to be construed broadly, e.g., "connected" can be a fixed connection or a removable connection; or may be a mechanical connection through an intermediate transmission. The specific meaning of the above terms in the present application can be understood by those of ordinary skill in the art according to specific circumstances.

Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that changes, modifications, substitutions and alterations can be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.

Claims (6)

1. The utility model provides an incineration boiler heat recovery and gas cleaning integrated system, including boiler island (1) and gas island (2), its characterized in that: a smoke baffle plate door (1-4) is arranged between the upper part of a hearth (1-1) of the boiler island (1) and the convection heat exchange cavity (1-3); a flue gas inlet of the flue gas island (2) is communicated with a hearth (1-1) at the upstream position of a flue gas baffle door (1-4) through a flue gas circulating pipeline I (3-1), and a flue gas outlet of the flue gas island (2) is connected between the downstream of the flue gas baffle door (1-4) of the boiler island (1) and the upstream of the convection heat exchange cavity (1-3) through a flue gas circulating pipeline II (3-2); the convection heat exchanger (1-2) is arranged in the convection heat exchange cavity (1-3), the purified flue gas exchanges heat in the convection heat exchange cavity (1-3), the flue gas after heat exchange is called as low-temperature flue gas, and the low-temperature flue gas is sent to a chimney (6) through a flue gas pipeline (4) through a draught fan (5) to be discharged to the atmosphere, so that an integrated system for comprehensive heat energy recycling and flue gas purification treatment through an incineration boiler is formed.

2. The incineration boiler heat energy recovery and flue gas purification integrated system according to claim 1, wherein: the flue gas island (2) comprises a flue gas treatment body, a flue gas circulating pipeline (2-5), a dosing device (2-6) and a circulating fan (2-7); the flue gas treatment body comprises a clean room (2-1), a pollution room (2-2), a partition plate (2-3) and a high-temperature-resistant composite filter cylinder (2-4); the clean room (2-1) and the pollution room (2-2) are filtered through a high-temperature resistant composite filter cylinder (2-4) and isolated through a partition plate (2-3) to be divided into an upper chamber and a lower chamber; the upper port of the high-temperature resistant composite filter cylinder (2-4) is an opening and is used for discharging clean flue gas, and the bottom port of the high-temperature resistant composite filter cylinder is closed and is used for blocking polluted flue gas; the side wall of the high-temperature resistant composite filter cylinder (2-4) is distributed with filter holes, dust is filtered through the high-temperature resistant composite filter cylinder (2-4), and the filter holes are connected to a fly ash conveying system through a dust falling pipeline.

3. The incineration boiler heat energy recovery and flue gas purification integrated system according to claim 2, wherein: the high-temperature resistant composite filter cylinder (2-4) consists of a high-temperature resistant ceramic filter cylinder (2-4-1) and a vanadium-titanium-tungsten catalyst layer (2-4-2) coated on the outer surface.

4. The incineration boiler heat energy recovery and flue gas purification integrated system according to claim 2, wherein: the smoke circulating pipeline (2-5) adopts a circulating fan (2-7) to forcibly ventilate.

5. The incineration boiler heat energy recovery and flue gas purification integrated system according to claim 2, wherein: the upper end part of the high-temperature resistant composite filter cylinder (2-4) is provided with a step which is convenient to clamp; and mounting holes for clamping the high-temperature-resistant composite filter cylinder (2-4) are distributed on the partition plate (2-3).

6. The incineration boiler heat energy recovery and flue gas purification integrated system according to claim 2, wherein: a dosing device (2-6) is arranged on the upstream of the flue gas circulating pipeline (2-5) and on the inlet pipeline of the flue gas treatment body; the chemical adding device (2-6) is used for adding chemical agents, including but not limited to a desulfurizer, a denitrifier and a dioxin removal agent storage tank, and the bottom of the chemical adding device is connected with the flue gas circulation pipeline (2-5) through a control valve.

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