CN115046207A

CN115046207A - Method and system for improving denitration flue gas temperature through pyrolysis gas afterburning

Info

Publication number: CN115046207A
Application number: CN202210655439.2A
Authority: CN
Inventors: 聂鑫; 刘辉; 谢贝贝; 成汭珅; 周凌宇; 柳宏刚
Original assignee: Thermal Power Research Institute
Current assignee: Thermal Power Research Institute
Priority date: 2022-06-10
Filing date: 2022-06-10
Publication date: 2022-09-13
Anticipated expiration: 2042-06-10
Also published as: CN115046207B; JP3243145U

Abstract

The invention discloses a method and a system for increasing the temperature of denitration flue gas by supplementary combustion of pyrolysis gas. A method for increasing the temperature of denitration flue gas by supplementary combustion of pyrolysis gas comprises the following steps: collecting solid waste and sending it into a pyrolysis furnace for pyrolysis to obtain Combustible pyrolysis product, the combustible pyrolysis product is sent to the incinerator for incineration to obtain high temperature flue gas, if the denitration reaction temperature of the denitration reactor of the power plant boiler is lower than the required temperature of the denitration catalyst, the high temperature flue gas is The gas is fed into the denitration reactor, and if the denitration reaction temperature of the denitration reactor is greater than or equal to the required temperature of the denitration catalyst, the high temperature flue gas is fed into the furnace of the power plant boiler. The method for increasing the temperature of denitration flue gas provided by the pyrolysis gas supplementary combustion has the advantages of increasing the temperature of the denitration reactor, making full use of solid waste and protecting the environment.

Description

Method and system for improving denitration flue gas temperature through pyrolysis gas afterburning

Technical Field

The invention relates to the technical field of solid waste coupling power generation, in particular to a method and a system for improving denitration flue gas temperature by pyrolysis gas afterburning.

Background

The urban multi-source industrial solid waste has the characteristics of high calorific value, strong pollution source and other resources and pollution attributes, and the resource disposal technology is more emphasized.

The renewable energy power generation peak regulation capacity is limited, the load change is fast, severe examination is brought to the peak regulation of a power grid, and the development of new energy power generation is restricted. In order to consume renewable energy, peak regulation is carried out by a thermal power generating unit with the largest power generation ratio in China, but the denitration environmental protection problem with wide load needs to be solved under the condition of low load of a coal-fired boiler. When the current boiler operates at low load, the temperature of the flue gas at the outlet of the economizer is usually lower than the temperature window of the 320-420 ℃ catalyst activity reaction of the selective catalytic reduction flue gas denitration system, so that the selective catalytic reduction flue gas denitration system cannot be normally put into operation, and the continuous and stable operation of the flue gas denitration system becomes necessary requirements due to the increasingly strict emission standard.

Disclosure of Invention

The present invention is based on the discovery and recognition by the inventors of the following facts and problems: pyrolysis is one of effective ways for realizing industrial organic solid waste energy gradient recovery at present. Through pyrolysis pretreatment, industrial organic solid waste can be converted into pyrolysis gas, pyrolysis oil and pyrolysis coke which are suitable for disposal of coal-fired power plants.

The present invention is directed to solving, at least to some extent, one of the technical problems in the related art.

Therefore, the embodiment of the invention provides a method for improving the denitration flue gas temperature by the pyrolysis gas after-combustion, and the method for improving the denitration flue gas temperature by the pyrolysis gas after-combustion has the advantages of improving the temperature of a denitration reactor, fully utilizing solid wastes and protecting the environment.

According to the method for improving the denitration flue gas temperature by the pyrolysis gas after-combustion, disclosed by the embodiment of the invention, the method for improving the denitration flue gas temperature by the pyrolysis gas after-combustion comprises the following steps: collecting solid waste and feeding the solid waste into a pyrolysis furnace for pyrolysis to obtain a combustible pyrolysis product, feeding the combustible pyrolysis product into an incinerator for incineration to obtain high-temperature flue gas, feeding the high-temperature flue gas into a denitration reactor of a power plant boiler if the denitration reaction temperature of the denitration reactor is lower than the required temperature of the denitration catalyst, and feeding the high-temperature flue gas into a hearth of the power plant boiler if the denitration reaction temperature of the denitration reactor is higher than or equal to the required temperature of the denitration catalyst. .

The method for improving the denitration flue gas temperature by pyrolysis gas afterburning disclosed by the embodiment of the invention has the advantages of improving the temperature of a denitration reactor, fully utilizing solid wastes and protecting the environment.

In some embodiments, a crusher processes the solid waste and conveys the solid waste to the pyrolysis furnace via a feeder.

In some embodiments, the combustible pyrolysis product is combustible gas produced by the pyrolysis furnace processing the solid waste, the pyrolysis furnace delivering the combustible gas to the incinerator.

In some embodiments, a thermal storage tank is coupled to the pyrolysis furnace and provides heat to the pyrolysis furnace.

In some embodiments, the incinerator provides heat to the thermal storage tank or utility power of a power plant provides electrical heating to the thermal storage tank.

In some embodiments, the heat source of the thermal storage tank further comprises high temperature flue gas or steam of the power plant boiler, the high temperature flue gas or the steam being circulated between the thermal storage tank and the power plant boiler.

In some embodiments, the heat source of the pyrolysis furnace further comprises high temperature flue gas of the power plant boiler and the incinerator.

In some embodiments, an air preheating system of the power plant boiler provides hot air to the incinerator.

In some embodiments, the high temperature flue gas produced by the incinerator is delivered to a front end flue of the denitration reactor.

According to the system for improving the denitration flue gas temperature through the supplementary combustion of the pyrolysis gas, the system for improving the denitration flue gas temperature through the supplementary combustion of the pyrolysis gas comprises a feeding device, a pyrolysis device and a power plant boiler, wherein the feeding device comprises a crusher and a feeding machine, the crusher is connected with the feeding machine, the feeding machine is connected with the pyrolysis device, the pyrolysis device comprises a pyrolysis furnace, a heat storage tank and an incinerator, the pyrolysis furnace is connected with the feeding machine, the heat storage tank is connected with the pyrolysis furnace and supplies heat to the pyrolysis furnace, the pyrolysis furnace is connected with the incinerator to convey high-temperature flue gas to the incinerator, the incinerator exchanges heat with the heat storage tank, the power plant boiler is provided with a denitration reactor, and the denitration reactor is connected with the incinerator to receive the high-temperature flue gas.

Drawings

FIG. 1 is a schematic structural diagram of a system for increasing denitration flue gas temperature by post-combusting pyrolysis gas in an embodiment of the invention.

Reference numerals: 1. a crusher; 2. a feeder; 3. a pyrolysis furnace; 4. a heat storage tank; 5. an incinerator; 6. a power plant boiler; 7. a denitration reactor; 8. high-temperature flue gas; 9. an air preheating system; 10. service power.

Detailed Description

Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings. The embodiments described below with reference to the drawings are illustrative and intended to be illustrative of the invention and are not to be construed as limiting the invention.

In order to further implement the national policy of comprehensive utilization of solid waste, fully play the storage role of the coal-fired unit, reduce the emission level of carbon dioxide of the thermal power unit, utilize the coal-electric unit to carry out coupling power generation on sludge, garbage and the like, and is a technical means for carrying out harmless treatment on the solid waste. Pyrolysis is one of the effective ways to realize the step recovery of industrial organic solid waste energy at present. Through pyrolysis pretreatment, industrial organic solid waste can be converted into pyrolysis gas, pyrolysis oil and pyrolysis coke which are suitable for disposal of coal-fired power plants.

According to the method for improving the denitration flue gas temperature by the pyrolysis gas after-combustion, disclosed by the embodiment of the invention, the method for improving the denitration flue gas temperature by the pyrolysis gas after-combustion comprises the following steps: collect solid useless and send into pyrolysis oven 3 and carry out the pyrolysis, obtain flammable pyrolysis product, send flammable pyrolysis product into incinerator 5 and burn, obtain high temperature flue gas, burn incinerator 5 and can adopt chain incinerator 5. If the denitration reaction temperature of the denitration reactor 7 of the power plant boiler 6 is lower than the required temperature of the denitration catalyst, the high-temperature flue gas is sent into the denitration reactor 7, and if the denitration reaction temperature of the denitration reactor 7 is greater than or equal to the required temperature of the denitration catalyst, the high-temperature flue gas is sent into the hearth of the power plant boiler 6. Therefore, the coal-fired power plant is utilized to treat general solid waste to generate pyrolysis gas for afterburning, and heat generated by afterburning is sent to the denitration reactor 7 so as to improve the temperature of the denitration reactor 7, improve the temperature of the denitration reactor 7 while treating the solid waste, and have good social benefit and economic benefit. The harmless treatment of the solid waste is realized by utilizing the self environmental protection facilities of the coal-fired power plant, so that the reduction, the recycling and the harmless treatment of the solid waste are realized, the environment is protected, and the operation cost is reduced.

In some embodiments, the crusher 1 processes and conveys the solid waste to the pyrolysis furnace 3 through the feeder 2.

From this, handle solid useless follow-up pyrolysis oven of being convenient for fully to pyrolyze solid useless through the breaker, carry solid useless speed of being convenient for control solid useless input pyrolysis oven and the input volume useless admittedly through the batcher, ensure the pyrolysis effect useless admittedly.

In some embodiments, the combustible pyrolysis product is combustible gas produced by the pyrolysis furnace 3 processing solid waste, and the pyrolysis furnace 3 delivers the combustible gas to the incinerator 5.

Specifically, admittedly useless the pyrolysis produces combustible gas in pyrolysis oven 3, and the gas port of pyrolysis oven 3 carries combustible gas to burn burning furnace 5 and burns, and combustible gas is convenient for carry, need not conveyor to shift pyrolysis coke and pyrolysis oil in pyrolysis oven 3, is convenient for clean burning furnace 5 of burning.

In some embodiments, the thermal storage tank 4 is connected to the pyrolysis furnace 3 and supplies heat to the pyrolysis furnace 3. The heat storage tank 4 is capable of collecting and storing heat, and the heat storage tank 4 maintains the temperature of the pyrolysis furnace 3. Specifically, the heat storage tank 4 employs a molten salt heat storage tank 4.

From this, the pyrolysis furnace passes through heat storage tank heat supply, can guarantee the temperature stability of pyrolysis furnace, ensures that the solid useless abundant pyrolysis in the pyrolysis furnace, and heat storage tank is favorable to the flexible operation of unit and further improves degree of depth peak regulation ability.

In some embodiments, the incinerator 5 provides heat to the thermal storage tank 4 or the service electricity 10 of the power plant provides electrical heating to the thermal storage tank 4.

Specifically, heat storage tank 4 links to each other with the station service 10 of power plant, and heat storage tank 4 adopts the electrical heating can consume the surplus electric quantity of a part power plant and improves the degree of depth peak shaving ability of unit, and heat storage tank 4 can make full use of the heat of burning furnace 5 with the high temperature flue gas heat transfer that burns burning furnace 5, and the heat that burns burning furnace 5 production gets into heat storage tank 4 and is favorable to the unit to move in a flexible way, and heat storage tank 4 stores the heat and plays energy saving and consumption reduction's purpose.

In some embodiments, the heat source of the thermal storage tank 4 further comprises high temperature flue gas 8 or steam of the power plant boiler 6, the high temperature flue gas 8 or steam being circulated between the thermal storage tank 4 and the power plant boiler 6.

Specifically, the high-temperature flue gas 8 or steam of the power plant boiler 6 supplies heat to the heat storage tank 4, and the flue gas or steam after heat exchange is returned to the power plant boiler 6.

In some embodiments, the heat source of the pyrolysis furnace 3 also includes high temperature flue gas of the power plant boiler 6, the incinerator 5.

Specifically, the heat source of the pyrolysis furnace 3 is provided by high-temperature flue gas of a power plant boiler 6 and an incinerator 5, the requirement of the pyrolysis furnace 3 on external energy is reduced, the deep peak regulation capacity of a unit is improved, and energy consumption is reduced.

In some embodiments, the air preheating system 9 of the power plant boiler 6 provides hot air to the incinerator 5.

Therefore, an air preheating device for supplying secondary air to the incinerator can be omitted by the aid of the air preheating system of the power plant boiler, and equipment cost is reduced.

In some embodiments, the high-temperature flue gas generated by the incinerator 5 is delivered to the front end flue of the denitration reactor 7. Specifically, when the power boiler 6 is under high load, the denitration reaction temperature of the denitration reactor 7 meets the temperature required by the denitration catalyst, the high-temperature flue gas of the incinerator 5 is delivered to the hearth of the power boiler 6 to increase the hearth temperature, and a part of the high-temperature flue gas is delivered to the molten salt heat storage tank 4 to exchange heat so as to provide a heat source for the pyrolysis furnace 3.

From this, burn the high temperature flue gas of burning furnace and improved the denitration reaction temperature under the power boiler low-load after getting into the front end flue of denitration reactor, guaranteed the work efficiency of denitration reactor.

According to the system for improving the denitration smoke temperature through the afterburning of the pyrolysis gas, the system for improving the denitration smoke temperature through the afterburning of the pyrolysis gas comprises a feeding device, a pyrolysis device and a power plant boiler 6, wherein the feeding device comprises a crusher 1 and a feeder 2, the crusher 1 is connected with the feeder 2, the feeder 2 is connected with the pyrolysis device, the pyrolysis device comprises a pyrolysis furnace 3, a heat storage tank 4 and an incinerator 5, the pyrolysis furnace 3 is connected with the feeder 2, the heat storage tank 4 is connected with the pyrolysis furnace 3 and supplies heat to the pyrolysis furnace 3, the pyrolysis furnace 3 is connected with the incinerator 5 to convey high-temperature smoke to the incinerator 5, the incinerator 5 exchanges heat with the heat storage tank 4, the power plant boiler 6 is provided with a denitration reactor 7, and the denitration reactor 7 is connected with the incinerator 5 to receive the high-temperature smoke from the incinerator 5.

The technical advantages of the system for increasing the denitration flue gas temperature by pyrolysis gas afterburning according to the embodiment of the invention are the same as those of the method for increasing the denitration flue gas temperature by pyrolysis gas afterburning, and are not described herein again.

In the description of the present invention, it is to be understood that the terms "central," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," "circumferential," and the like are used in the orientations and positional relationships indicated in the drawings for convenience in describing the invention and to simplify the description, but are not intended to indicate or imply that the device or element so referred to must have a particular orientation, be constructed in a particular orientation, and be operated in a particular manner, and are not to be construed as limiting the invention.

Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of the present invention, "a plurality" means at least two, e.g., two, three, etc., unless specifically limited otherwise.

In the present invention, unless otherwise expressly stated or limited, the terms "mounted," "connected," "secured," and the like are to be construed broadly and can, for example, be fixedly connected, detachably connected, or integrally formed; may be mechanically coupled, may be electrically coupled or may be in communication with each other; they may be directly connected or indirectly connected through intervening media, or they may be connected internally or in any other suitable relationship, unless expressly stated otherwise. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.

In the present invention, unless otherwise expressly stated or limited, the first feature "on" or "under" the second feature may be directly contacting the first and second features or indirectly contacting the first and second features through an intermediate. Also, a first feature "on," "over," and "above" a second feature may be directly or diagonally above the second feature, or may simply indicate that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature may be directly under or obliquely under the first feature, or may simply mean that the first feature is at a lesser elevation than the second feature.

In the present disclosure, the terms "one embodiment," "some embodiments," "an example," "a specific example," or "some examples" and the like mean that a specific feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the present disclosure. In this specification, the schematic representations of the terms used above are not necessarily intended to refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Furthermore, various embodiments or examples and features of different embodiments or examples described in this specification can be combined and combined by one skilled in the art without contradiction.

Although embodiments of the present invention have been shown and described, it will be understood that the above embodiments are exemplary and not to be construed as limiting the present invention and that many changes, modifications, substitutions and alterations can be made to the above embodiments by those of ordinary skill in the art without departing from the scope of the present invention.

Claims

1. The method for improving the denitration flue gas temperature by pyrolysis gas afterburning is characterized by comprising the following steps of:

collecting solid waste and feeding the solid waste into a pyrolysis furnace for pyrolysis to obtain a combustible pyrolysis product;

sending the combustible pyrolysis product into an incinerator for incineration to obtain high-temperature flue gas;

if the denitration reaction temperature of the denitration reactor of the power plant boiler is lower than the required temperature of the denitration catalyst, feeding the high-temperature flue gas into the denitration reactor;

and if the denitration reaction temperature of the denitration reactor is greater than or equal to the required temperature of the denitration catalyst, sending the high-temperature flue gas into the hearth of the power plant boiler.

2. The method for increasing the denitration flue gas temperature by post-combusting pyrolysis gas as claimed in claim 1, wherein a crusher processes the solid waste and conveys the solid waste to the pyrolysis furnace through a feeder.

3. A method in accordance with claim 1, wherein the combustible pyrolysis product is a combustible gas generated by the pyrolysis furnace processing the solid waste, and the pyrolysis furnace transmits the combustible gas to the incinerator.

4. The method for increasing the denitration flue gas temperature by post-combusting pyrolysis gas as claimed in claim 1, wherein a heat storage tank is connected with the pyrolysis furnace and supplies heat to the pyrolysis furnace.

5. The method for increasing denitration flue gas temperature by post-combustion of pyrolysis gas as claimed in claim 4, wherein the incinerator supplies heat to the heat storage tank or the plant power of the power plant electrically heats the heat storage tank.

6. The method of claim 4, wherein the heat source of the heat storage tank further comprises high-temperature flue gas or steam of the power plant boiler, and the high-temperature flue gas or the steam circulates between the heat storage tank and the power plant boiler.

7. The method for increasing the denitration flue gas temperature by post-combusting pyrolysis gas as claimed in claim 4, wherein the heat source of the pyrolysis furnace further comprises high-temperature flue gas of the power plant boiler and the incinerator.

8. The method for increasing the denitration flue gas temperature by the afterburning of the pyrolysis gas as claimed in claim 1, wherein the air preheating system of the power plant boiler provides hot air to the incinerator.

9. The method for increasing the temperature of the denitrated smoke through the afterburning of the pyrolysis gas as claimed in claim 1, wherein the high-temperature smoke generated by the incinerator is delivered to a front end flue of the denitration reactor.

10. The utility model provides a system for pyrolysis gas afterburning improves denitration gas temperature which characterized in that includes:

the feeding device comprises a crusher and a feeder, the crusher is connected with the feeder, and the feeder is connected with the pyrolysis device;

the pyrolysis device comprises a pyrolysis furnace, a heat storage tank and an incinerator, the pyrolysis furnace is connected with the feeding machine, the heat storage tank is connected with the pyrolysis furnace and supplies heat to the pyrolysis furnace, the pyrolysis furnace is connected with the incinerator to convey high-temperature flue gas to the incinerator, and the incinerator exchanges heat with the heat storage tank; and

the power plant boiler is provided with a denitration reactor, and the denitration reactor is connected with the incinerator to receive the high-temperature flue gas.