CN111214953A - Heat accumulating type SCR denitration technology and system for wet desulfurization flue gas - Google Patents

Heat accumulating type SCR denitration technology and system for wet desulfurization flue gas Download PDF

Info

Publication number
CN111214953A
CN111214953A CN202010191081.3A CN202010191081A CN111214953A CN 111214953 A CN111214953 A CN 111214953A CN 202010191081 A CN202010191081 A CN 202010191081A CN 111214953 A CN111214953 A CN 111214953A
Authority
CN
China
Prior art keywords
flue gas
heat
temperature
heat storage
scr denitration
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
CN202010191081.3A
Other languages
Chinese (zh)
Inventor
谭自强
李鹏
瞿浪宇
梁学武
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Changsha Hasky Environmental Protection Technology Development Co ltd
Original Assignee
Changsha Hasky Environmental Protection Technology Development Co ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Changsha Hasky Environmental Protection Technology Development Co ltd filed Critical Changsha Hasky Environmental Protection Technology Development Co ltd
Priority to CN202010191081.3A priority Critical patent/CN111214953A/en
Publication of CN111214953A publication Critical patent/CN111214953A/en
Pending legal-status Critical Current

Links

Images

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
    • B01D53/34—Chemical or biological purification of waste gases
    • B01D53/74—General processes for purification of waste gases; Apparatus or devices specially adapted therefor
    • B01D53/86—Catalytic processes
    • B01D53/8621—Removing nitrogen compounds
    • B01D53/8625—Nitrogen oxides
    • B01D53/8631—Processes characterised by a specific device
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
    • B01D53/34—Chemical or biological purification of waste gases
    • B01D53/343—Heat recovery
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
    • B01D53/34—Chemical or biological purification of waste gases
    • B01D53/346—Controlling the process

Landscapes

  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Environmental & Geological Engineering (AREA)
  • Health & Medical Sciences (AREA)
  • Biomedical Technology (AREA)
  • Analytical Chemistry (AREA)
  • General Chemical & Material Sciences (AREA)
  • Oil, Petroleum & Natural Gas (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Treating Waste Gases (AREA)

Abstract

The invention discloses a heat accumulating type SCR denitration process and a heat accumulating type SCR denitration system for wet flue gas desulfurization, wherein the denitration process comprises the steps of communicating N heat accumulating chambers with an SCR denitration device through a heating chamber, dividing the N heat accumulating chambers into N groups, firstly storing heat in the first group of heat accumulating chambers, then carrying out primary heating, secondary heating and denitration on the wet flue gas desulfurization, storing heat in the next group of heat accumulating chambers by purified flue gas, and continuously carrying out flue gas denitration in an alternate heat accumulating and heat releasing mode. The system comprises a booster fan, a temperature rising chamber, an SCR denitration device, a tail exhaust chimney and at least two heat storage chambers, wherein a first air port of each heat storage chamber is communicated with the booster fan, a second air port of each heat storage chamber is communicated with an inlet of the SCR denitration device through the temperature rising chamber, a third air port of each heat storage chamber is communicated with an outlet of the SCR denitration device, and a fourth air port of each heat storage chamber is communicated with the tail exhaust chimney. The denitration process and the denitration system efficiently utilize the waste heat of the denitrated clean flue gas, improve the heat recovery rate, greatly reduce the fuel consumption and reduce the system operation cost.

Description

Heat accumulating type SCR denitration technology and system for wet desulfurization flue gas
Technical Field
The invention belongs to the technical field of flue gas purification, and relates to an SCR denitration process and system for wet desulfurization flue gas, in particular to a low-temperature flue gas heat accumulating type SCR denitration process and system at the rear end of wet desulfurization.
Background
The production process in the fields of iron and steel industry, smelting industry and the like can generate a large amount of industrial flue gas, and the nitrogen oxides and the sulfur oxides contained in the flue gas are main pollutants for forming acid rain and photochemical smog, so that the ecological environment is seriously damaged. Along with the stricter environmental protection standards, the emission index of the flue gas is gradually reduced, and the comprehensive treatment of the desulfurization and the denitrification of the industrial flue gas is not slow.
Selective Catalytic Reduction (SCR) denitration technology for Selective Catalytic Reduction (SCR) of flue gas, ammonia gas or urea is used as a denitration agent to be sprayed into a high-temperature flue gas denitration system, and NOx in the flue gas is decomposed into N under the action of a catalyst2And H2And O, so that the aim of purifying the flue gas is fulfilled, the reaction effect is optimal when the temperature of the flue gas is 300-400 ℃ under the action of the catalyst, the system is stable to operate, the denitration efficiency can reach more than 90%, no discharged wastewater exists, and the method has strong advantages.
However, because the specific reaction temperature interval of the catalyst in the SCR denitration process is 300-400 ℃, the existing SCR flue gas denitration process mostly adopts a front end arrangement mode, namely, the SCR reactor is arranged between a boiler economizer and an air preheater, and flue gas led out from the boiler economizer enters the air preheater after passing through the SCR reactor. This is currently the most common arrangement. The following features are provided according to the current arrangement: high dust content, SO2The concentration is high, so that the phenomena of easy poisoning, blockage and the like of the catalyst are caused, the denitration efficiency is influenced, and the denitration efficiency cannot reach the emission index, therefore, the traditional concept is changed, and the SCR process is arranged at the rear end of a dedusting and desulfurization system to become a research and development target.
The wet desulphurization process is the most widely and mature flue gas desulphurization treatment technology currently and occupies a great proportion in the fields of smelting industry, steel industry and the like, and after the wet desulphurization of the flue gas, the sulfur dioxide content in the flue gas can be reduced to 100mg/Nm3The water content and sulfuric acid mist content in the flue gas are lower and are completeThe method is suitable for the reaction conditions of the SCR process, but the flue gas temperature is lower after wet desulphurization, generally only about 40 ℃, and the window reaction temperature for denitration of the SCR process cannot be met. At present, the mainstream mode is to exchange heat between the waste heat of the denitration gas and the desulfurization flue gas through a GGH heat exchanger and then raise the temperature of the flue gas to the requirement of the reaction temperature of a catalyst by assisting a coal or natural gas burner to directly heat the flue gas, but the method has low heat exchange efficiency, so that the consumption of combustion raw materials is large, the operation cost is not facilitated to be saved, and meanwhile, the GGH heat exchanger has large heat exchange area, so that the occupied area of equipment is large, the equipment is too fat, the exhaust emission temperature is high, and the project operation risk is large.
Chinese patent document No. 201910764114.6, "a two-stage heating denitration device suitable for wet desulfurization", provides a bipolar heating denitration device for wet desulfurization, which adopts a GGH heat exchanger to heat up tail flue gas to inlet flue gas, and then secondarily heats the flue gas through a hot-blast stove to a reaction temperature range of SCR, after the desulfurized flue gas passes through the GGH heat exchanger, the temperature of the flue gas is raised from 58.8 ℃ to 275 ℃, and then the flue gas is mixed and heated by the hot-blast stove to 322 ℃, and the clean flue gas after reaction is reduced from 322 ℃ to 92.8 ℃. According to the method, the temperature of the flue gas needs to be raised to be close to 50 ℃ through the hot blast stove, and the system needs to consume more fuel to maintain the balance, so that the operation cost is not favorably saved.
Disclosure of Invention
The invention aims to overcome the defects of the prior art and provides a heat accumulating type SCR denitration process and system for wet desulphurization flue gas, which can fully utilize flue gas waste heat, greatly reduce external heat supply, have high heat recovery efficiency, small fuel consumption and low operation cost, and can also be named as a Selective heat accumulating type Catalytic Reduction denitration process and system, namely an SRCR (Selective Regenerative Catalytic Reduction of NOx) denitration process and system for short.
In order to solve the technical problems, the invention adopts the following technical scheme.
A heat accumulating type SCR denitration process for wet desulfurization flue gas comprises the following steps:
s1: the method comprises the following steps of (1) communicating N heat storage chambers with an SCR denitration device through a heating chamber, wherein the N heat storage chambers are divided into N groups, N is more than or equal to 2, and N is more than or equal to 2 and less than or equal to N, heating wet desulfurization flue gas to a set SCR denitration temperature, wherein the SCR denitration temperature is selected from 300-400 ℃, and then conveying the flue gas to a first group of heat storage chambers for heat storage until the temperature of the flue gas discharged from the first group of heat storage chambers is 10-30 ℃ higher than that of the wet desulfurization flue gas;
s2: switching a conveying path of the wet desulfurization flue gas, conveying the wet desulfurization flue gas to a first group of heat storage chambers which store heat, heating the wet desulfurization flue gas by heat release in the first group of heat storage chambers, heating the obtained first temperature-raised flue gas by a second heating temperature-raised chamber to make the temperature of the obtained second temperature-raised flue gas be the set SCR denitration temperature, conveying the second temperature-raised flue gas to the SCR denitration device for denitration, and conveying the denitrated purified flue gas to a second group of heat storage chambers for heat storage until the outlet temperature of the first group of heat storage chambers which are releasing heat is 10-30 ℃ lower than the set SCR denitration temperature or the temperature of the flue gas discharged from the second group of heat storage chambers which are storing heat is 10-30 ℃ higher than the temperature of the wet desulfurization flue gas;
s3: switching a conveying path of the wet flue gas desulfurization, conveying the wet flue gas desulfurization to a second group of heat storage chambers which store heat, heating the wet flue gas desulfurization by the second group of heat storage chambers by releasing heat, heating the obtained primary heated flue gas by the heating chamber for the second time to make the temperature of the obtained secondary heated flue gas be the set SCR denitration temperature, and conveying the secondary heated flue gas to the SCR denitration device for denitration,
when N is 2 (N is more than or equal to 2), conveying the denitrated purified flue gas to a first group of heat storage chambers for heat storage until the outlet temperature of the heat storage chambers of the second group which are releasing heat is 10-30 ℃ lower than the set SCR denitration temperature or the temperature of the flue gas discharged from the heat storage chambers of the first group which are storing heat is 10-30 ℃ higher than the temperature of the wet desulphurization flue gas;
when N is 3 (N is more than 2), conveying the denitrated purified flue gas into a third group of heat storage chambers for heat storage until the outlet temperature of the heat storage chamber of the second group which is releasing heat is 10-30 ℃ lower than the set SCR denitration temperature or the temperature of the flue gas discharged from the heat storage chamber of the third group which is storing heat is 10-30 ℃ higher than the temperature of the wet desulphurization flue gas, switching the conveying path of the wet desulphurization flue gas, conveying the wet desulphurization flue gas into the heat storage chamber of the third group which is storing heat, heating the wet desulphurization flue gas by heat release in the third group of heat storage chambers for the first time, heating the obtained first heated flue gas for the second time through a heating chamber to ensure that the temperature of the obtained second heated flue gas is the set SCR denitration temperature, conveying the second heated flue gas into an SCR denitration device for denitration, and conveying the denitrated purified flue gas into the heat storage chamber of the first group for heat storage, until the outlet temperature of the heat-releasing third group of heat storage chambers is 10-30 ℃ lower than the set SCR denitration temperature or the temperature of the flue gas discharged by the heat-storing first group of heat storage chambers is 10-30 ℃ higher than the temperature of the wet desulphurization flue gas;
when the temperature is more than 3 and less than or equal to N (N is more than 2), conveying the denitrified purified flue gas into a third group of heat storage chambers for heat storage until the outlet temperature of the heat storage chamber of the second group which is releasing heat is 10-30 ℃ lower than the set SCR denitration temperature or the temperature of the flue gas discharged from the heat storage chamber of the third group which is storing heat is 10-30 ℃ higher than the temperature of the flue gas of the wet desulphurization, switching the conveying path of the flue gas of the wet desulphurization, repeating the procedures of primary heating and temperature rise of the flue gas of the wet desulphurization in the heat storage chamber group which is storing heat, secondary heating and temperature rise in the temperature rise chamber, denitration in an SCR denitration device and conveying the purified flue gas to the heat storage chamber of the next group, and sequentially storing heat from the heat storage chambers of the fourth group to the Nth group until the outlet temperature of the heat storage chamber of the N-1 group which is releasing heat is 10-30 ℃ lower than the set SCR denitration temperature or the flue gas temperature of the heat storage chamber of Continuously heating the wet desulfurization flue gas in the heat storage chambers of the Nth group for primary heating and heating, heating in the heating chambers for secondary heating and denitration in an SCR denitration device, and conveying the purified flue gas to the heat storage chambers of the first group for heat storage according to the process until the outlet temperature of the heat storage chambers of the Nth group which are releasing heat is 10-30 ℃ lower than the set SCR denitration temperature or the temperature of the flue gas discharged from the heat storage chambers of the first group which are storing heat is 10-30 ℃ higher than the temperature of the wet desulfurization flue gas;
s4: and repeating the step S2 and the step S3, and continuously treating the wet desulphurization flue gas.
In the heat accumulating type SCR denitration process of wet desulfurization flue gas, preferably, the flow rate of the empty chamber in the heat accumulating chamber is controlled to be 1.0Nm3/(m2s)～3.0Nm3/(m2s)。
In the heat accumulating type SCR denitration process of wet flue gas desulfurization, preferably, in step S1, the heating and temperature raising is to send the wet flue gas desulfurization to a temperature raising chamber through an nth group of heat accumulating chambers to heat and raise the temperature, and then to enter the first group of heat accumulating chambers to store heat after passing through an unreacted SCR denitration device.
As a general technical concept, the invention also provides a heat accumulating type SCR denitration system for wet flue gas desulfurization, which comprises a booster fan, a heating chamber, an SCR denitration device, a tail flue gas chimney and at least two heat accumulating chambers, wherein each heat accumulating chamber is provided with a first gas port, a second gas port, a third gas port and a fourth gas port, the first gas port of each heat accumulating chamber is communicated with the booster fan, the second gas port of each heat accumulating chamber is communicated with an inlet of the SCR denitration device through the heating chamber, the third gas port of each heat accumulating chamber is communicated with an outlet of the SCR denitration device, and the fourth gas port of each heat accumulating chamber is communicated with the tail flue gas chimney.
In the above heat accumulating type SCR denitration system for wet flue gas desulfurization, preferably, the first gas port and the fourth gas port of the heat accumulating chamber are one port, and/or the second gas port and the third gas port of the heat accumulating chamber are separate.
In the above heat accumulating type SCR denitration system for wet flue gas desulfurization, preferably, the first gas port and the fourth gas port of the heat accumulating chamber are separate, and/or the second gas port and the third gas port of the heat accumulating chamber are one port.
Specifically, the following cases may be mentioned:
the first and fourth gas ports of the regenerator are one port, and the second and third gas ports of the regenerator are separate.
The first gas port and the fourth gas port of the regenerator are one port, and the second gas port and the third gas port of the regenerator are one port.
The first and fourth gas ports of the regenerator are separate and the second and third gas ports of the regenerator are separate.
The first and fourth ports of the regenerator are separate and the second and third ports of the regenerator are one port.
In the heat accumulating type SCR denitration system for wet flue gas desulfurization, preferably, the second gas port of each heat accumulating chamber is communicated with the inlet of the temperature rising chamber, and the outlet of the temperature rising chamber is communicated with the inlet of the SCR denitration device.
Preferably, the first air port of the heat storage chamber is connected with the booster fan, the second air port of the heat storage chamber is connected with the inlet of the warming chamber, the third air port of the heat storage chamber is connected with the outlet of the SCR denitration device, the fourth air port of the heat storage chamber is connected with the tail exhaust chimney through pipelines, and each pipeline is provided with a valve. Valves are arranged on the pipelines respectively connected with the first gas port, the second gas port, the third gas port and the fourth gas port of the regenerative chamber. More preferably, the valve is an automatic valve that can be controlled by a conventional reversing stage control system, but is not limited thereto.
In the heat accumulating type SCR denitration system for wet flue gas desulfurization, preferably, thermometers are respectively disposed on a pipeline between the second gas port of the heat accumulating chamber and the inlet of the temperature rising chamber, a pipeline between the outlet of the temperature rising chamber and the inlet of the SCR denitration device, and a pipeline between the fourth gas port of the heat accumulating chamber and the tail flue chimney.
In the heat accumulating type SCR denitration system for wet flue gas desulfurization, preferably, the booster fan is communicated with the wet flue gas desulfurization system through a pipeline, and a valve is arranged on the pipeline. More preferably, the valve is a manual valve.
In the denitration process of the invention, the outlet temperature of the regenerator which is releasing heat is preferably 15-25 ℃ lower than the set SCR denitration temperature, and the temperature of the flue gas discharged by the regenerator which is storing heat is preferably 15-25 ℃ higher than the temperature of the wet desulfurization flue gas.
In the denitration process of the present invention, the heat storage time is usually 1 to 5min, but is not limited thereto.
In the denitration process and the denitration system, the heating mode of the heating chamber can adopt but not limited to natural gas combustion heating or electric furnace heating and other heating modes.
In the denitration process and the denitration system, the heat storage chamber can only be in an up-in and down-out mode or in an up-in and down-out mode, and heat storage and heat release cannot be achieved simultaneously.
In the denitration system of the invention, when N is equal to N, only one regenerator in the regenerator group is provided.
Compared with the prior art, the invention has the advantages that:
(1) the denitration process of the invention divides N heat storage chambers into N groups, adopts the heat storage chambers to store heat and release heat in turn, can ensure the system to operate circularly and stably, and ensures that the other heat storage chambers are in a heat storage state in the process of heating low-temperature flue gas by single heat release to prepare for heat release of the next flow. In the prior art, when the GGH is adopted for primary heating and temperature rise, the target temperature cannot be regulated and controlled, so that the secondary heating temperature is basically and continuously fixed at about 50 ℃, and a large amount of fuel is continuously required for supplying secondary heating, in the invention, the fuel consumption can be effectively reduced by controlling the temperature difference between the outlet temperature of the regenerator which is releasing heat and the set SCR denitration temperature (namely the catalytic reduction reaction temperature) or the temperature difference between the temperature of the flue gas discharged from the regenerator which is storing heat and the wet desulphurization flue gas (the low-temperature flue gas discharged from a desulphurization system), and the heat recovery rate is obviously improved. Specifically, when the wet flue gas desulfurization is heated through heat release of the heat storage chamber, the outlet temperature of the heat storage chamber is initially close to the catalytic temperature, at the moment, the required fuel is very little, the outlet temperature of the heat storage chamber is gradually reduced along with the increase of heat storage time, the secondary heating energy supply is gradually increased, when the outlet temperature of the heat storage chamber which is releasing heat is lower than the set SCR denitration temperature by a certain temperature (selected from 10-30 ℃), the conveying path of the wet flue gas desulfurization is timely switched to the next group of heat storage chambers which have stored heat, so that the secondary heating energy supply is reduced again, the circulation is carried out, the fuel quantity is always kept at a low level, and the total fuel quantity is greatly reduced. That is, the target temperature of the one-time heating temperature rise of the invention can be flexibly regulated, which provides an opportunity for greatly saving fuel. Because the heat release of one heat storage chamber and the heat storage process of the other heat storage chamber are carried out simultaneously, when the temperature of the discharged heat storage chamber in heat storage is 10-30 ℃ higher than the temperature of the wet desulphurization flue gas entering the system for the first time, on one hand, the heat storage temperature in the heat storage chamber is proved to reach the set SCR denitration temperature, on the other hand, only a small amount of heat is discharged to the outside of the system from the energy conservation of the whole system, the heat recovery rate is very high, and meanwhile, the visual effect of common white smoke at the air outlet of the chimney can be eliminated due to the proper temperature rise. Compared with the closest GGH denitration process in the prior art, the heat accumulating type SCR denitration process has the advantages of obvious heat recovery rate and fuel consumption. Meanwhile, compared with the mainstream oxidation denitration and medicament denitration process in the current market, due to the essential difference of the reaction principle, the denitration process does not generate any wastewater, does not generate substances such as nitrate and nitrite in the operation process, does not cause secondary pollution, and also has obvious advantages.
(2) In the denitration process, the temperature difference between the outlet temperature of the regenerator which is releasing heat and the set SCR denitration temperature is set to be 10-30 ℃, and the too high temperature difference is not beneficial to saving the fuel consumption, and more heat is required when heat is stored again, so that the operation cost is improved. The temperature of raising the temperature for the second time is maintained at the set SCR denitration temperature, the catalyst is easily deactivated due to the high temperature, the system stability control is not facilitated, the system heat recovery efficiency is low due to the low temperature, and the operation cost is not facilitated to be saved.
(3) In the denitration process, the temperature difference between the temperature of the flue gas discharged from the regenerative chamber which is storing heat and the temperature of the flue gas subjected to wet desulphurization is limited to 10-30 ℃, the temperature discharged from the flue gas in a single flow is gradually increased along with the saturation of the heat storage capacity of the regenerative chamber, when the temperature difference reaches 10-30 ℃ (namely the temperature discharged from the regenerative chamber reaches 50-80 ℃), the temperature discharged from the regenerative chamber can be switched to the next flow, the heat loss is large due to the fact that the temperature discharged from the regenerative chamber is too high, the operation cost is high, the duration of the single flow is short due to the fact that the temperature discharged from the regenerative chamber is.
(4) In the denitration process of the invention, the flow rate of the empty chamber of the regenerator is preferably controlled to be 1.0Nm3/(m2s)～3.0Nm3/(m2s), but not limited thereto, the heat recovery efficiency will be higher in this gas velocity range, with the most reasonable investment costs.
(5) The denitration system disclosed by the invention has the advantages that the temperature of the rear end of the heating chamber is linked with the temperature of the rear end of the heat storage chamber, the fuel consumption of the heating chamber is controlled, the fuel consumption can be obviously reduced, the operation cost of the system is reduced, the fuel combustion amount is greatly reduced when the temperature of the flue gas is higher after the initial heating in the previous period, the fuel combustion amount is gradually increased according to the reduction of the temperature of the front end, the outlet temperature of the heating chamber is kept stable, and the denitration efficiency of the rear end denitration system and the temperature of the discharged flue gas are ensured to be stable. The system is provided with at least two heat storage chambers, each heat storage chamber can be communicated with the SCR denitration device through a heat storage chamber, and the plurality of heat storage chambers can circulate flue gas independently or in a grouping mode, so that heat storage or heat release can be carried out on the heat storage chambers in turn, and the circulation can be realized. Whole system carries out the cooling for denitration back flue gas when rising temperature for the entry low temperature flue gas for the first time, make full use of the circulation of flue gas waste heat and a small amount of fuel heat, heat recovery efficiency is higher than heat transfer equipment such as traditional GGH heat exchanger, can reach more than 95%, and the required fuel consumption of maintaining system operation is still less, under the prerequisite of system steady operation, is favorable to practicing thrift project running cost by a wide margin. Compared with heat exchange equipment such as GGH heat exchangers and the like, the system has the advantages that the occupied area is small, the heat storage chambers (heat storage chambers) can be separately arranged, the equipment arrangement is flexible, meanwhile, the manufacturing cost of the heat storage chambers is lower than that of the traditional heat exchange equipment, and the project investment can be effectively reduced.
(6) Compared with the traditional denitration system with the preposed denitration, the SCR denitration system is arranged at the rear end of the desulfurization system, SO that smoke dust and SO in flue gas are reduced2The influence on the catalyst increases the service life of the catalyst, reduces the operation and maintenance cost of enterprises, and has no smoke dust and SO2Compared with the traditional system, the system stability is greatly improved, the phenomena of catalyst blockage, inactivation and the like do not exist, and secondly, the exhaust temperature of the tail exhaust chimney after denitration is improved to a certain extent compared with the temperature of the smoke generated by the original wet desulphurization, so that the visual effect of 'white smoke' at the air outlet of the chimney can be eliminated.
Drawings
Fig. 1 is a schematic structural diagram of a heat accumulating type SCR denitration system for wet flue gas desulfurization in embodiments 1 and 2 of the present invention.
Illustration of the drawings:
1. a booster fan; 2. a first valve; 3. a second valve; 4. a third valve; 5. a fourth valve; 6. a first regenerator; 7. a second regenerator; 8. a fifth valve; 9. a sixth valve; 10. heating the greenhouse; 11. an SCR denitration device; 12. a seventh valve; 13. an eighth valve; 14. a thermometer; 15. a ninth valve; 16. a tail chimney; 17. a first gas port; 18. a second gas port; 19. a third gas port; 20. a fourth gas port; 21. a regenerator.
Detailed Description
The invention is further described below with reference to the drawings and specific preferred embodiments of the description, without thereby limiting the scope of protection of the invention.
The materials and devices used in the following examples are commercially available unless otherwise specified.
Example 1
The invention relates to a heat accumulating type SCR denitration process of wet desulphurization flue gas, which comprises the following steps:
s1: the N regenerators 21 are communicated with the inlet of the heating chamber 10, the outlet of the heating chamber 10 is communicated with the inlet of the SCR denitration device 11, the N regenerators 21 are divided into N groups, N is more than or equal to 2, and N is more than or equal to 2 and less than or equal to N. In this embodiment, N and N are both 2, and for convenience of describing the flue gas flow path, the regenerator 21 is divided into a first regenerator 6 (i.e., a first group of regenerators) and a second regenerator 7 (i.e., a second group of regenerators). Heating the wet desulphurization flue gas to 350 ℃ of the set SCR denitration temperature, and then conveying the flue gas to the first heat storage chamber 6 for heat storage until the temperature of the flue gas discharged out of the first heat storage chamber 6 is 20 ℃ higher than that of the wet desulphurization flue gas;
s2: switching a conveying path of the wet desulfurization flue gas, conveying the wet desulfurization flue gas to a first heat storage chamber 6 which stores heat, heating the wet desulfurization flue gas by heat release in the first heat storage chamber 6 for the first time, heating the obtained first heated flue gas by a heating chamber 10 for the second time to maintain the temperature of the obtained second heated flue gas at 350 ℃ of the set SCR denitration temperature, then conveying the second heated flue gas to an SCR denitration device 11 for denitration, conveying the denitrated purified flue gas to a second heat storage chamber 7 for heat storage until the outlet temperature of the first heat storage chamber 6 which releases heat (i.e. the outlet temperature of the hot side, and also the temperature of a fifth valve 8) is 20 ℃ lower than the set SCR denitration temperature, namely the outlet temperature of the first heat storage chamber 6 is 330 ℃, or until the temperature of the flue gas discharged from the second heat storage chamber 7 which stores heat is 20 ℃ higher than the temperature of the wet desulfurization flue gas (40 ℃), namely, the temperature of the flue gas discharged out of the second heat storage chamber 7 which is storing heat reaches 60 ℃;
s3: switching a conveying path of the wet desulfurization flue gas, conveying the wet desulfurization flue gas to a second heat storage chamber 7 which stores heat, performing primary heating temperature rise on the wet desulfurization flue gas by the second heat storage chamber 7 through heat release, performing secondary heating temperature rise on the obtained primary temperature rise flue gas through a temperature rise chamber 1010 to maintain the temperature of the obtained secondary temperature rise flue gas at a set SCR denitration temperature of 350 ℃, then conveying the secondary temperature rise flue gas to an SCR denitration device 11 for denitration, conveying the purified flue gas after denitration to a first heat storage chamber 6 for heat storage until the outlet temperature of the second heat storage chamber 7 which releases heat is 20 ℃ lower than the set SCR denitration temperature or the temperature of the flue gas discharged from the first heat storage chamber 6 which stores heat is 20 ℃ higher than the temperature of the wet desulfurization flue gas;
s4: and repeating the step S2 and the step S3, so that the first heat storage chamber 6 and the second heat storage chamber 7 alternately store heat and release heat, and the wet desulphurization flue gas is continuously treated by combining the heating chamber 10 and the SCR denitration device 11.
In the present embodiment, the cell flow rate in the first regenerative chamber 6 and the second regenerative chamber 7 is controlled to 1.0Nm3/(m2s)～3.0Nm3/(m2s)。
In this embodiment, the heating and temperature raising in step S1 is performed by sending the wet flue gas after desulfurization to the temperature raising chamber 10 through the second group of regenerators 7 that do not store heat, and then passing through the SCR denitration device 11 that does not react and then entering the first regenerator 6 to store heat.
In this embodiment, if N is 2 < N ≦ N, step S3 performs the processes of heating up the second regenerator 7 once in S3, heating up the temperature chamber 10 twice, and denitration in the SCR denitration device 11, and then sends the purified flue gas to the next regenerator (or group) for heat storage until the outlet temperature of the second regenerator 7 that is releasing heat is 20 ℃ lower than the set SCR denitration temperature or the flue gas temperature discharged from the next regenerator (or group) that is storing heat is 20 ℃ higher than the temperature of the wet flue gas, and repeats the flow of heating up the wet flue gas once in the regenerators that have stored heat, heating up the second in the temperature chamber 10, denitration in the SCR denitration device 11, and sending the purified flue gas to the next regenerator (or group) for heat storage, and stores heat in the third to nth regenerators (or groups) in sequence until the outlet temperature of the N-1 (or group) that is releasing heat is 20 ℃ lower than the set SCR temperature Or the temperature of the flue gas discharged from the Nth heat storage chamber (or the group) which is storing heat is 20 ℃ higher than the temperature of the wet desulphurization flue gas, the wet desulphurization flue gas is heated and heated in the Nth heat storage chamber (or the group) for the first time, heated and heated in the heating chamber 10 for the second time, denitrated in the SCR denitration device 11, and the purified flue gas is conveyed to the first heat storage chamber 6 for heat storage according to the process until the outlet temperature of the Nth heat storage chamber (or the group) which is releasing heat is 20 ℃ lower than the set SCR denitration temperature or the temperature of the flue gas discharged from the first heat storage chamber 6 which is storing heat is 20 ℃ higher than the temperature of the wet desulphurization flue gas.
In a heat accumulating type SCR denitration system for wet flue gas desulfurization according to the present invention, as shown in fig. 1, two regenerators 21 are provided, which are a first regenerator 6 and a second regenerator 7, respectively, and the denitration process of the above embodiment 1 can be performed by using the denitration system, but is not limited thereto. When N is more than 2 and less than or equal to N, the number of the regenerative chambers 21 is increased correspondingly.
The denitration system comprises a booster fan 1, a heating chamber 10, an SCR denitration device 11, a tail exhaust chimney 16 and two heat storage chambers 21, wherein each heat storage chamber 21 is provided with a first air port 17, a second air port 18, a third air port 19 and a fourth air port 20, the first air port 17 of each heat storage chamber 21 is communicated with the booster fan 1, the second air port 18 of each heat storage chamber 21 is communicated with an inlet of the SCR denitration device 11 through the heating chamber 10, the third air port 19 of each heat storage chamber 21 is communicated with an outlet of the SCR denitration device 11, and the fourth air port 20 of each heat storage chamber 21 is communicated with the tail exhaust chimney 16.
In this embodiment, the first port 17 and the fourth port 20 of the regenerator 21 are one port, and the second port 18 and the third port 19 of the regenerator 21 are separate.
In the present embodiment, the second port 18 of each regenerator 21 communicates with the inlet of the temperature increasing chamber 10, and the outlet of the temperature increasing chamber 10 communicates with the inlet of the SCR denitration device 11.
In the embodiment, the first air port 17 of each heat storage chamber 21 and the booster fan 1, the second air port 18 of each heat storage chamber 21 and the inlet of the warming chamber 10, the third air port 19 of each heat storage chamber 21 and the outlet of the SCR denitration device 11, and the fourth air port 20 of each heat storage chamber 21 and the tail exhaust chimney 16 are connected by pipes, and each pipe is provided with a valve.
Specifically, a first valve 2 is arranged on a pipeline between a first air port 17 of the first heat storage chamber 6 and the booster fan 1, a fifth valve 8 is arranged between a second air port 18 of the first heat storage chamber 6 and an inlet of the warming chamber 10, a seventh valve 12 is arranged on a pipeline between an outlet of the SCR denitration device 11 and a third air port 19 of the first heat storage chamber 6, a second valve 3 is arranged on a pipeline between a fourth air port 20 of the first heat storage chamber 6 and a tail smoke exhaust chimney 16, a third valve 4 is arranged on a pipeline between the first air port 17 of the second heat storage chamber 7 and the booster fan 1, a sixth valve 9 is arranged between the second air port 18 of the second heat storage chamber 7 and the inlet of the warming chamber 10, an eighth valve 13 is arranged on a pipeline between the outlet of the SCR denitration device 11 and the third air port 19 of the second heat storage chamber 7, a fourth valve 5 is arranged on a pipeline between the fourth air port 20 of the second heat storage chamber 7 and the tail smoke exhaust chimney 16, the first port 17 (and the fourth port 20), the second port 18, and the third port 19 of the second regenerator 7 are omitted from FIG. 1. The pipeline connected with the first air port 17 of the first regenerator 6 is provided with two branches, one branch is communicated with the booster fan 1, the first valve 2 is arranged on the branch, the other branch is communicated with the tail discharge chimney 16, and the second valve 3 is arranged on the branch. The pipeline connected with the first air port 17 of the second regenerator 7 is provided with two branches, one branch is communicated with the booster fan 1, the third valve 4 is arranged on the branch, the other branch is communicated with the tail discharge chimney 16, and the fourth valve 5 is arranged on the branch. Each valve is an automatic valve and can be controlled by a reversing-stage control system. The reversing control system is an existing control system, two or more automatic valves can be used for directional switching as a group when the valves are controlled, and the directional valves can also be used as switching pivots, so that risks such as flue gas leakage and the like caused by flue gas in the switching process are avoided.
In this embodiment, thermometers 14 are provided on the pipeline between the second port 18 of the regenerator 21 and the inlet of the warming chamber 10, on the pipeline between the outlet of the warming chamber 10 and the inlet of the SCR denitration device 11, and on the pipeline between the fourth port 20 of the regenerator 21 and the tail flue chimney 16.
In this embodiment, the booster fan 1 is communicated with the wet desulphurization system through a pipeline, and a manual valve is arranged on the pipeline.
The specific working flow of the heat accumulating type SCR denitration process and system for wet desulphurization flue gas of the embodiment is as follows:
s1, first regenerator 6 stores heat: the ninth valve 15, the third valve 4, the sixth valve 9, the seventh valve 12 and the second valve 3 are opened, and the first valve 2, the fifth valve 8, the eighth valve 13 and the fourth valve 5 are closed. After the valves are set, the booster fan 1 is started, wet desulphurization flue gas at about 40 ℃ is introduced into the second heat storage chamber 7 through the ninth valve 15 and the third valve 4, enters the temperature raising chamber 10 through the second heat storage chamber 7 and the sixth valve 9, the temperature of the flue gas is raised to 350 ℃ in the temperature raising chamber 10 mainly through fuel heating, then is introduced into the first heat storage chamber 6 through the SCR denitration device 11 and the seventh valve 12 which do not start to operate, heat is stored in the first heat storage chamber 6, the temperature of the first heat storage chamber 6 reaches 350 ℃, the flue gas passes through the first heat storage chamber 6 and then is discharged to the tail smoke exhaust chimney 16 through the second valve 3, the heat storage is stopped when the temperature of the discharged air reaches 60 ℃, and the heat storage of the first heat storage chamber 6 is completed.
S2: second regenerator 7 stores heat: switching a conveying path of the wet desulphurization flue gas, opening a first valve 2, a fifth valve 8, an eighth valve 13 and a fourth valve 5, closing a third valve 4, a sixth valve 9, a seventh valve 12 and a second valve 3, and enabling the low-temperature wet desulphurization flue gas to enter a first regenerator 6 through the first valve 2, wherein the temperature is higher because the first regenerator 6 is subjected to heat storage in the step S1, the heat accumulator in the first regenerator 6 releases heat, the temperature of the flue gas is increased for the first time, the temperature of the flue gas is increased to 350 ℃, and in the process that the flue gas passes through the first regenerator 6, the outlet temperature of the first regenerator 6 is slowly decreased to 330 ℃ from 350 ℃ along with the increase of the heat release time of the heat accumulator. The gas after primary heating enters the heating chamber 10 through a fifth valve 8 to be heated for the second time so as to keep the outlet temperature of the heating chamber 10 stable at 350 ℃, and thermometers 14 are arranged at the inlet and the outlet of the heating chamber 10 to be linked. The flue gas passes through the heating chamber 10 and then enters the SCR denitration device 11, and the secondarily heated flue gas and ammonia water or urea complete catalytic reduction reaction on the surface of the denitration catalyst at 350 ℃. The purified flue gas after reaction enters the second heat storage chamber 7 through the eighth valve 13 to store heat for the second heat storage chamber 7 until the temperature of the flue gas outlet of the second heat storage chamber 7 is 60 ℃, and then is discharged to the tail smoke exhaust chimney 16 through the fourth valve 5 to be discharged at high altitude.
S3: first regenerator 6 stores heat: after the above process is finished, the opening and closing of the respective movable valves are switched, the first valve 2, the fifth valve 8, the eighth valve 13 and the fourth valve 5 are closed, the third valve 4, the sixth valve 9, the seventh valve 12 and the second valve 3 are opened, so that the wet desulfurization flue gas enters the second heat storage chamber 7 for heating and temperature rise, the second heat storage chamber 7 releases heat, the heated flue gas enters the first heat storage chamber 6 for heat storage after secondary temperature rise and denitration, until the outlet temperature of the first heat storage chamber 6 rises to 60 ℃, and the cooled flue gas is discharged to the tail flue gas exhaust chimney 16.
S4: the steps of S2 and S3 are repeated, the valves are switched to be opened and closed circularly, the first heat storage chamber 6 and the second heat storage chamber 7 are used for heat storage in turn, energy is kept in the denitration system, the continuous heat storage and heat release processes of the system are maintained, and high heat recovery rate and fuel saving are achieved.
Example 2
An example of the application of the heat accumulating type SCR denitration process and system for wet flue gas desulfurization of the present invention can adopt the heat accumulating type SCR denitration system for wet flue gas desulfurization of embodiment 1, as shown in fig. 1, but is not limited thereto. Firstly, the smelting flue gas is subjected to primary denitration by a conventional SNCR process furnace, and then the flue gas discharged from the furnace is subjected to an organic amine desulfurization system to remove the dust content and SO in the flue gas2The outlet flue gas condition of the desulfurization system is shown in table 1, and the flue gas enters the heat accumulating type SCR denitration system for denitration, which comprises the following steps:
TABLE 1 flue gas condition after wet desulfurization
Figure BDA0002415929070000101
S1: the system is started (startup) to store heat for the first regenerator 6: the ninth valve 15, the third valve 4, the sixth valve 9, the seventh valve 12 and the second valve 3 are opened, and the first valve 2, the fifth valve 8, the eighth valve 13 and the fourth valve 5 are closed. The first valve 2 to the eighth valve 13 are all automatic valves, and the ninth valve 15 is a manual valve. After the valves are set, the booster fan 1 is started, smelting flue gas (wet desulphurization flue gas) with the temperature of about 40 ℃ from the rear end of the desulphurization system is introduced into the second heat storage chamber 7 through the ninth valve 15 and the third valve 4, enters the temperature raising chamber 10 through the second heat storage chamber 7 and the sixth valve 9, is heated by fuel in the temperature raising chamber 10 to raise the temperature of the flue gas to 350 ℃, is subjected to removal of nitrogen oxides in the flue gas through the SCR denitration device 11, is introduced into the first heat storage chamber 6 through the seventh valve 12, stores heat in the first heat storage chamber 6 to enable the temperature of the first heat storage chamber 6 to reach 350 ℃, and is discharged to the tail smoke exhaust chimney 16 through the second valve 3 after passing through the first heat storage chamber 6, stops storing heat when the temperature of the discharged air reaches 60 ℃, and completes heat storage in the first heat storage chamber 6. The flue gas channel communicated with the third valve 4, the sixth valve 9, the seventh valve 12 and the second valve 3 can be called a second flue gas circulation line, the flue gas channel communicated with the first valve 2, the fifth valve 8, the eighth valve 13 and the fourth valve 5 can be called a first flue gas circulation line, and the first flue gas circulation line and the second flue gas circulation line pass through the temperature rising chamber 10 and the SCR denitration device 11.
S2: and switching the conveying path of the wet desulphurization flue gas to store heat for the second heat storage chamber 7: opening a first valve 2, a fifth valve 8, an eighth valve 13 and a fourth valve 5, namely opening all the valves on the first flue gas flow line, closing a third valve 4, a sixth valve 9, a seventh valve 12 and a second valve 3, namely closing all the valves on the second flue gas flow line, so that the low-temperature wet desulphurization flue gas enters a first heat storage chamber 6 through the first valve 2, because the first heat storage chamber 6 is subjected to heat storage in the step S1 and has higher temperature, a heat accumulator in the first heat storage chamber 6 releases heat, the temperature of the flue gas is increased for the first time, the temperature of the flue gas is increased to 350 ℃, and in the process that the flue gas passes through the first heat storage chamber 6, along with the heat release of the heat accumulator, the outlet temperature of the first heat storage chamber 6 is slowly reduced to 330 ℃, the size of the heat storage chamber is 2.1m long by 2.4m wide, and the gas velocity of the empty chamber is 1.27Nm3/(m2s) and the height of the thermal storage layer is 1.35 m. The gas after primary heating enters the warming chamber 10 through a fifth valve 8 to be heated for the second time so as to keep the outlet temperature of the warming chamber 10 stable at 350 ℃, thermometers 14 are arranged at an inlet and an outlet of the warming chamber 10 to be linked, the inlet temperature is T0103, the outlet temperature is T0104, the fuel consumption of secondary heating gradually rises along with the reduction of the flue gas temperature after primary heating, but the total is small, and the average natural gas consumption is 15Nm3H is used as the reference value. The consumption of natural gas in the existing denitration process adopting GGH is at least 42Nm3More than h. The flue gas passes through a temperature rising chamber 10 and then enters an SCR denitration device 11, and the secondarily heated flue gas is mixed with the flue gas under the condition of proper high temperatureAmmonia water or urea completes catalytic reduction reaction on the surface of the denitration catalyst, and the concentration of nitrogen oxide in the outlet flue gas is reduced to 43.2mg/m3. The purified flue gas after reaction enters the second heat storage chamber 7 through the eighth valve 13 to store heat for the second heat storage chamber 7, the temperature of the flue gas outlet of the second heat storage chamber 7 is 40-60 ℃, and the purified flue gas is discharged to the tail smoke exhaust chimney 16 through the fourth valve 5 to be discharged at high altitude. When the process is run for 2 minutes, the outlet temperature of the first regenerator 6 is reduced to 330 ℃ and the outlet temperature of the second regenerator 7 is increased to 60 ℃, and the process is completed.
S3: first regenerator 6 stores heat: after the flow is finished, the opening and closing of the valves are switched simultaneously through the control system, namely the valves on the first flue gas flow line are closed, the valves on the second flue gas flow line are opened, so that the wet desulfurization flue gas enters the second heat storage chamber 7 to be heated and heated, the second heat storage chamber 7 releases heat, the heated flue gas enters the first heat storage chamber 6 to be stored after being heated and denitrated for the second time until the outlet temperature of the first heat storage chamber 6 is raised to 60 ℃, and the cooled flue gas is exhausted to the tail exhaust chimney 16.
S4: and repeating the steps of S2 and S3, and circularly switching the opening and closing of each valve to alternately utilize the first flue gas circulation line and the second flue gas circulation line to keep energy inside the denitration system, so that the continuous heat storage and heat release process of the system is maintained, and the high heat recovery rate and the great saving of fuel are realized.
In this embodiment, a plurality of regenerators 21 may be added, and it is sufficient that part of the regenerators 21 store heat and part of the regenerators 21 release heat.
In this embodiment, the heat recovery rate is 95%, the system operation cost can be saved by 65% compared with the GGH exchange, for example, the fuel operation cost of the GGH heat exchanger is about 89.9 ten thousand yuan per year, while the SRCR denitration technology of the present invention can save the fuel operation cost by about 32.1 ten thousand yuan per year and 57.8 ten thousand yuan per year.
The foregoing is merely a preferred embodiment of the invention and is not intended to limit the invention in any manner. Although the present invention has been described with reference to the preferred embodiments, it is not intended to be limited thereto. Those skilled in the art can make many possible variations and modifications to the disclosed embodiments, or equivalent modifications, without departing from the spirit and scope of the invention, using the methods and techniques disclosed above. Therefore, any simple modification, equivalent replacement, equivalent change and modification made to the above embodiments according to the technical essence of the present invention are still within the scope of the protection of the technical solution of the present invention.

Claims (10)

1. A heat accumulating type SCR denitration process of wet desulphurization flue gas is characterized by comprising the following steps:
s1: the method comprises the following steps of (1) communicating N heat storage chambers (21) with an SCR denitration device (11) through a heating chamber (10), dividing the N heat storage chambers (21) into N groups, wherein N is more than or equal to 2, and N is more than or equal to 2 and less than or equal to N, heating wet desulfurization flue gas to a set SCR denitration temperature, wherein the SCR denitration temperature is 300-400 ℃, and then conveying the flue gas to a first group of heat storage chambers for heat storage until the temperature of the flue gas discharged out of the first group of heat storage chambers is 10-30 ℃ higher than that of the wet desulfurization flue gas;
s2: switching a conveying path of the wet desulfurization flue gas, conveying the wet desulfurization flue gas to a first group of heat storage chambers which store heat, heating the wet desulfurization flue gas by heat release in the first group of heat storage chambers, heating the obtained primary heated flue gas by a second heating temperature rise in the heat rise chamber (10) to make the temperature of the obtained secondary heated flue gas be the set SCR denitration temperature, then conveying the secondary heated flue gas to the SCR denitration device (11) for denitration, and conveying the denitrated purified flue gas to a second group of heat storage chambers for heat storage until the outlet temperature of the first group of heat storage chambers which release heat is 10-30 ℃ lower than the set SCR denitration temperature or the temperature of the flue gas discharged from the second group of heat storage chambers which store heat is 10-30 ℃ higher than the temperature of the wet desulfurization flue gas;
s3: switching a conveying path of the wet flue gas desulfurization, conveying the wet flue gas desulfurization to a second group of heat storage chambers which store heat, heating the wet flue gas desulfurization by the second group of heat storage chambers by releasing heat, heating the obtained primary heated flue gas by the heat storage chambers (10) for a second time to make the temperature of the obtained secondary heated flue gas be the set SCR denitration temperature, and conveying the secondary heated flue gas to the SCR denitration device (11) for denitration,
when N is 2, conveying the denitrated purified flue gas to a first group of heat storage chambers for heat storage until the outlet temperature of the heat storage chambers in the heat release process is 10-30 ℃ lower than the set SCR denitration temperature or the temperature of the flue gas discharged from the heat storage chambers in the heat storage process is 10-30 ℃ higher than the temperature of the wet desulphurization flue gas;
when N is 3, conveying the denitrated purified flue gas into a third group of heat storage chambers for heat storage until the outlet temperature of the heat-releasing second group of heat storage chambers is 10-30 ℃ lower than the set SCR denitration temperature or the temperature of the flue gas discharged from the heat-storing third group of heat storage chambers is 10-30 ℃ higher than the temperature of the wet desulfurization flue gas, switching the conveying path of the wet desulfurization flue gas, conveying the wet desulfurization flue gas into the heat-storing third group of heat storage chambers, performing primary heating and temperature rise on the wet desulfurization flue gas by heat release in the third group of heat storage chambers, performing secondary heating and temperature rise on the obtained primary heated flue gas through a temperature rise chamber (10) to enable the temperature of the obtained secondary heated flue gas to be the set SCR denitration temperature, conveying the secondary heated flue gas into an SCR denitration device (11) for denitration, and conveying the denitrated purified flue gas into the first group of heat storage chambers for heat storage, until the outlet temperature of the heat-releasing third group of heat storage chambers is 10-30 ℃ lower than the set SCR denitration temperature or the temperature of the flue gas discharged by the heat-storing first group of heat storage chambers is 10-30 ℃ higher than the temperature of the wet desulphurization flue gas;
when the temperature is more than 3 and less than or equal to N, conveying the denitrified purified flue gas into a third group of heat storage chambers for heat storage until the outlet temperature of the heat-releasing second group of heat storage chambers is 10-30 ℃ lower than the set SCR denitration temperature or the temperature of the flue gas discharged from the heat-storing third group of heat storage chambers is 10-30 ℃ higher than the temperature of the wet desulphurization flue gas, switching the conveying path of the wet desulphurization flue gas, repeating the flow of primary heating and temperature rising of the wet desulphurization flue gas in the heat storage chambers which store heat, secondary heating and temperature rising in a heating chamber (10), denitration in an SCR denitration device (11), conveying the purified flue gas into the next group of heat storage chambers for heat storage, and sequentially storing heat from the fourth group of heat storage chambers to the Nth group of heat storage chambers until the outlet temperature of the heat-releasing N-1 group of heat storage chambers is 10-30 ℃ lower than the set SCR denitration temperature or the temperature of the flue gas discharged from the heat storage chambers which store heat is N group of heat storage chambers which The temperature is 10-30 ℃, the wet desulfurization flue gas is continuously heated and heated in the heat storage chamber N for the first time, heated and heated in the heating chamber 10 for the second time, denitrated in the SCR denitration device 11, and the purified flue gas is conveyed to the heat storage chamber first for heat storage according to the process until the outlet temperature of the heat storage chamber N which is releasing heat is 10-30 ℃ lower than the set SCR denitration temperature or the temperature of the flue gas discharged from the heat storage chamber first which is storing heat is 10-30 ℃ higher than the temperature of the wet desulfurization flue gas;
s4: and repeating the step S2 and the step S3, and continuously treating the wet desulphurization flue gas.
2. The regenerative SCR denitration process of wet desulfurization flue gas according to claim 1, wherein the flow rate of empty chamber in the regenerative chamber (21) is controlled to 1.0Nm3/(m2s)～3.0Nm3/(m2s)。
3. The heat accumulating type SCR denitration process of the wet flue gas desulfurization of claim 2, wherein in step S1, the wet flue gas desulfurization is sent to the temperature increasing chamber (10) for heating and temperature increasing after passing through the Nth group of heat accumulating chambers, and then enters the first group of heat accumulating chambers for heat accumulation after passing through the SCR denitration device (11) which has not reacted.
4. The heat accumulating type SCR denitration system for the wet desulfurization flue gas is characterized by comprising a booster fan (1), a heating chamber (10), an SCR denitration device (11), a tail exhaust chimney (16) and at least two heat accumulating chambers (21), wherein each heat accumulating chamber (21) is provided with a first air port (17), a second air port (18), a third air port (19) and a fourth air port (20), the first air port (17) of each heat accumulating chamber (21) is communicated with the booster fan (1), the second air port (18) of each heat accumulating chamber (21) is communicated with an inlet of the SCR denitration device (11) through the heating chamber (10), the third air port (19) of each heat accumulating chamber (21) is communicated with an outlet of the SCR denitration device (11), and the fourth air port (20) of each heat accumulating chamber (21) is communicated with the tail exhaust chimney (16).
5. A regenerative SCR denitration system according to claim 4, characterized in that the first (17) and fourth (20) gas ports of the regenerator (21) are one port, and/or the second (18) and third (19) gas ports of the regenerator (21) are separate.
6. A regenerative SCR denitration system according to claim 4, characterized in that the first (17) and fourth (20) gas ports of the regenerator (21) are separate and/or the second (18) and third (19) gas ports of the regenerator (21) are one port.
7. A heat accumulating type SCR denitration system for wet flue gas desulfurization according to claim 4, wherein the second air port (18) of each heat accumulating chamber (21) is communicated with the inlet of the temperature rising chamber (10), and the outlet of the temperature rising chamber (10) is communicated with the inlet of the SCR denitration device (11).
8. The heat accumulating type SCR denitration system for the wet desulphurization flue gas according to any one of claims 4 to 7, wherein a first air port (17) of the heat accumulating chamber (21) is connected with the booster fan (1), a second air port (18) of the heat accumulating chamber (21) is connected with an inlet of the warming chamber (10), a third air port (19) of the heat accumulating chamber (21) is connected with an outlet of the SCR denitration device (11), and a fourth air port (20) of the heat accumulating chamber (21) is connected with the tail smoke exhaust chimney (16) through pipelines, and each pipeline is provided with a valve.
9. The heat accumulating type SCR denitration system for wet flue gas desulfurization according to claim 8, wherein thermometers (14) are arranged on the pipeline between the second air port (18) of the heat accumulating chamber (21) and the inlet of the heat rising chamber (10), the pipeline between the outlet of the heat rising chamber (10) and the inlet of the SCR denitration device (11), and the pipeline between the fourth air port (20) of the heat accumulating chamber (21) and the tail smoke exhaust chimney (16).
10. The heat accumulating type SCR denitration system of the wet flue gas desulfurization according to claim 8, wherein the booster fan (1) is communicated with the wet flue gas desulfurization system through a pipeline, and a valve is arranged on the pipeline.
CN202010191081.3A 2020-03-18 2020-03-18 Heat accumulating type SCR denitration technology and system for wet desulfurization flue gas Pending CN111214953A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202010191081.3A CN111214953A (en) 2020-03-18 2020-03-18 Heat accumulating type SCR denitration technology and system for wet desulfurization flue gas

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202010191081.3A CN111214953A (en) 2020-03-18 2020-03-18 Heat accumulating type SCR denitration technology and system for wet desulfurization flue gas

Publications (1)

Publication Number Publication Date
CN111214953A true CN111214953A (en) 2020-06-02

Family

ID=70813152

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202010191081.3A Pending CN111214953A (en) 2020-03-18 2020-03-18 Heat accumulating type SCR denitration technology and system for wet desulfurization flue gas

Country Status (1)

Country Link
CN (1) CN111214953A (en)

Similar Documents

Publication Publication Date Title
CN105771946B (en) A kind of active coke regeneration system and regeneration method
CN107014217B (en) Coke oven gas utilization and flue gas treatment system of coking plant and treatment method thereof
CN204365100U (en) A kind of regenerative system of desulphurization denitration activated coke
CN106422695A (en) Desulfurization and denitration system for coke oven flue gas
CN208177248U (en) It is a kind of based on active carbon/coke coke oven flue gas system for desulfuration and denitration
CN112915724A (en) Integrated removal system and method for multiple pollutants in flue gas
CN110496527A (en) A kind of method of coke oven flue exhuast gas desulfurization denitration
CN107899413A (en) A kind of exhaust gas of hot-blast stove desulphurization denitration cooperates with administering method
CN211963739U (en) Heat accumulating type SCR denitration system for wet desulfurization flue gas
CN111214953A (en) Heat accumulating type SCR denitration technology and system for wet desulfurization flue gas
CN207729640U (en) A kind of water heat medium formula air preheater with SCR denitration function
CN206103709U (en) Glass high -temperature furnace flue gas energy saving and emission reduction clean system
CN105889895B (en) It is a kind of to change area and the type of flow to improve the economizer of SCR inlet smoke temperature
CN205613436U (en) Active burnt regeneration system
CN206229169U (en) The system for desulfuration and denitration of flue gases of cock oven
CN209221872U (en) A kind of recuperative heater flue gas denitrification system of two-stage accumulation of heat
CN203890290U (en) Coke oven equipment
CN209271187U (en) Denitration reaction device and smoke processing system
CN219494873U (en) Low oxygen-enriched air heat accumulation steady-state combustion double-smoke-discharging heating furnace device
CN106139900B (en) Glass high temperature kiln flue gas energy-saving and emission-reduction purification method
CN207169372U (en) A kind of flue gas purification system
CN216079867U (en) Flue gas treatment system
CN109260947A (en) A kind of recuperative heater flue gas denitrification system of two-stage accumulation of heat
CN220143408U (en) Improved low-temperature Claus catalyst regenerating device
CN219209526U (en) Multistage accuse temperature denitrification facility of industrial kiln

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination
CB03 Change of inventor or designer information
CB03 Change of inventor or designer information

Inventor after: Tan Ziqiang

Inventor after: Li Ke

Inventor after: Li Peng

Inventor after: Qu Langyu

Inventor after: Liang Xuewu

Inventor before: Tan Ziqiang

Inventor before: Li Peng

Inventor before: Qu Langyu

Inventor before: Liang Xuewu