Search

CN-122006450-A - Flue gas desulfurization, CO removal and denitration cooperative treatment system and control method thereof

CN122006450ACN 122006450 ACN122006450 ACN 122006450ACN-122006450-A

Abstract

The invention discloses a flue gas desulfurization, CO removal and denitration cooperative treatment system and a control method thereof, and belongs to the technical field of atmospheric pollutant treatment. The system comprises a temperature control device, an activated carbon desulfurization and denitrification device, a low-temperature CO removal device, an ultralow-temperature denitrification device and a chimney which are sequentially arranged along the flow direction of the flue gas, and is provided with a hierarchical ammonia spraying control device, a fan, a plurality of continuous flue gas emission monitoring mechanisms and a cooperative controller. The method utilizes the prepositive active carbon to remove SO 2 efficiently to protect the CO removal catalyst, utilizes the heat of desulfurization and CO removal reaction to realize post ultralow-temperature denitration self-maintenance temperature rise, does not need external heat supplement and GGH (gas heater) in the whole process, and combines a cooperative controller and graded ammonia spraying control to realize the cooperative treatment of precise ammonia spraying and multiple pollutants. The invention has the advantages of simple flow, low investment and operation cost, low energy consumption, no external heat supplement and the like.

Inventors

  • HUANG YUNTAO
  • JIA XIAOHUI
  • DONG KUN
  • LI BING
  • ZHANG DAN

Assignees

  • 一重集团大连工程建设有限公司

Dates

Publication Date
20260512
Application Date
20260414

Claims (10)

  1. 1. The flue gas desulfurization, CO and denitration cooperative treatment system is characterized by comprising a temperature control device (6), an activated carbon desulfurization, denitration device (1), a low-temperature CO removal device (2), an ultralow-temperature denitration device (3) and a chimney (4) which are communicated sequentially through a flue along the flue gas flowing direction; further comprises: The fan (10) is connected in series in the smoke flow flue and is used for providing smoke flow power; The first-stage ammonia spraying control device (7) is connected with a reactor in the active carbon desulfurization and denitrification device (1) through a pipeline; The two-stage ammonia spraying control device (8) is connected with an upstream flue of the ultralow-temperature denitration device (3) through a pipeline; The regenerated waste gas pipeline (5) of the low-temperature CO removal device (2) is communicated to an upstream flue of the temperature control device (6); A smoke emission continuous monitoring mechanism is arranged between the temperature control device (6) and the active carbon desulfurization and denitrification device (1), between the active carbon desulfurization and denitrification device (1) and the low-temperature CO removal device (2), between the low-temperature CO removal device (2) and the ultralow-temperature denitrification device (3) and on the chimney (4); The flue gas desulfurization and denitrification device further comprises a cooperative controller (9) which is respectively connected with each flue gas emission continuous monitoring mechanism, a primary ammonia spraying control device (7), a secondary ammonia spraying control device (8), a temperature control device (6), an active carbon desulfurization and denitrification device (1), a low-temperature CO removal device (2) and an ultralow-temperature denitrification device (3) in a signal manner and is used for cooperatively controlling the flue gas emission according to the measured value of the flue gas emission continuous monitoring mechanism.
  2. 2. The flue gas desulfurization, denitrification and CO-operation cooperative treatment system is characterized in that the activated carbon desulfurization and denitrification device (1) is provided with at least one group of activated carbon desulfurization and denitrification reactors, the low-temperature CO removal device (2) is provided with at least two groups of low-temperature CO removal reactors, the low-temperature CO removal reactors are used for enabling one group of low-temperature CO removal reactors to be switched between an operating state and a regeneration state, the activity temperature range of a low-temperature CO removal catalyst adopted by the low-temperature CO removal reactors is 100-200 ℃, the ultralow-temperature denitrification device (3) is provided with at least one group of denitrification reactors, each group of denitrification reactors is provided with at least two layers of low-temperature denitrification catalysts, and the activity temperature range of the ultralow-temperature denitrification catalyst is 120-200 ℃.
  3. 3. The flue gas desulfurization, CO-removal and denitration cooperative treatment system according to claim 2 is characterized in that the temperature control device (6) adopts a cold air doping mode or a flue gas cooler to limit the highest temperature of flue gas at the inlet of the active carbon desulfurization and denitration device (1), when the temperature is controlled by adopting the cold air doping mode, the temperature is adjusted by adjusting the opening of a cold air doping valve, and when the flue gas cooler is adopted, the temperature is adjusted by adjusting the flow of a cooling medium.
  4. 4. The flue gas desulfurization, CO and denitration cooperative treatment system according to claim 2 is characterized in that the first ammonia injection control device (7) comprises a first hot air pipeline and a first ammonia pipeline connected to the first hot air pipeline in a tandem mode, wherein the first ammonia pipeline is provided with a first ammonia flowmeter (701) and a first ammonia flow regulating valve (702), the first ammonia flowmeter (701) and the first ammonia flow regulating valve (702) are connected with a cooperative controller (9) in a signal mode, and the first ammonia injection flow is set by regulating the opening of the first ammonia flow regulating valve (702); The two-section ammonia spraying control device (8) comprises a two-section hot air pipeline and a two-section ammonia pipeline which is connected to the two-section hot air pipeline in a tandem mode, a two-section ammonia flowmeter (801) and a two-section ammonia flow regulating valve (802) are arranged on the two-section ammonia pipeline, the two-section ammonia flowmeter (801) and the two-section ammonia flow regulating valve (802) are connected with the cooperative controller (9) in a signal mode, and the two-section ammonia spraying flow is enabled to reach a set value through adjusting the opening of the two-section ammonia flow regulating valve (802).
  5. 5. The system of any one of claims 1-4, wherein the measured variables of each continuous monitoring mechanism for flue gas emission include flue gas flow, flue gas pressure, flue gas temperature, SO 2 content, NOx content, particulate content, CO content, NH 3 content, and moisture content.
  6. 6. A control method of a flue gas desulfurization, CO-removal and denitration cooperative treatment system, which is realized based on the system of any one of claims 1 to 5, and is characterized in that the method comprises the following steps: The temperature of the inlet flue gas is regulated and controlled, namely the temperature of the flue gas entering the active carbon desulfurization and denitrification device (1) is regulated and controlled by a temperature control device (6) according to the preset upper limit of the temperature of the inlet flue gas of the active carbon desulfurization and denitrification device (1); The low-temperature CO removing device (2) regeneration control, wherein a mode of combining timing regeneration and forced regeneration is adopted to execute regeneration switching adjustment on a low-temperature CO removing reactor in the low-temperature CO removing device (2); The primary ammonia spraying control, namely calculating and adjusting the primary ammonia spraying amount according to the flue gas parameters at the inlet of the active carbon desulfurization and denitrification device (1) and the preset denitrification efficiency; the secondary ammonia spraying control, namely calculating and adjusting the secondary ammonia spraying amount according to the flue gas parameters at the inlet of the ultralow temperature denitration device (3), the flue gas parameters discharged by the chimney (4) and the environmental protection discharge requirement; The above-mentioned adjustments are all performed by a coordinated controller (9).
  7. 7. The control method of the flue gas desulfurization, CO and denitration cooperative treatment system is characterized by specifically comprising the steps of setting an upper limit value Ts1 of the flue gas temperature of an inlet of an active carbon desulfurization and denitration device (1), and starting the temperature control device (6) to cool by a cooperative controller (9) when the measured temperature T1 of a continuous monitoring mechanism CEMS1 of flue gas emission before desulfurization arranged between the temperature control device (6) and the active carbon desulfurization and denitration device (1) exceeds Ts1, wherein the value range of the Ts1 is 140-160 ℃.
  8. 8. The control method of the flue gas desulfurization, CO and denitration cooperative treatment system according to claim 6 is characterized in that in the regeneration control of the low-temperature CO removal device (2), a regeneration period Tims1 is set during the time regeneration, and when the low-temperature CO removal operation time reaches the regeneration period Tims1, the cooperative controller (9) controls each group of low-temperature CO removal reactors to sequentially regenerate; The triggering condition of the forced regeneration is that when the CO removal efficiency of the low-temperature CO removal device (2) is lower than a set value E COS1 or the CO concentration C4 CO measured by a chimney flue gas emission continuous monitoring mechanism CEMS4 arranged on a chimney (4) is higher than the environment-friendly allowable emission concentration, the cooperative controller (9) controls each group of low-temperature CO removal reactors to sequentially carry out the forced regeneration.
  9. 9. The control method of the CO-treatment system for flue gas desulfurization, CO-removal and denitration according to claim 6, wherein the primary ammonia injection control is specifically to set denitration efficiency E NOxs1 of the activated carbon desulfurization, denitration device (1), and calculate primary ammonia injection amount set value V1 NH3 according to inlet flue gas flow V1, NOx content C1 NOx and moisture content C1 H2O measured by a continuous monitoring mechanism for flue gas emission before desulfurization CEMS1 arranged between the temperature control device (6) and the activated carbon desulfurization, denitration device (1), denitration efficiency set value E NOxs1 of the activated carbon desulfurization, denitration device (1), and excess coefficient k1, by the following steps: V1 NH3 =k1×V1×C1 NOx ×(1-C1 H2O )×10 -6 ×22.4/46; the primary ammonia flow regulating valve (702) is regulated by the cooperative controller (9), so that the flow measured by the primary ammonia flowmeter (701) is equal to the primary ammonia injection quantity set value V1 NH3 .
  10. 10. The method for controlling a CO-treatment system for flue gas desulfurization, CO-removal and denitration according to claim 6, wherein the secondary ammonia injection control is specifically implemented by calculating a secondary ammonia injection amount set value V2 NH3 according to a denitration inlet flue gas flow V3, a NOx content C3 NOx , a moisture content C3 H2O and an ammonia content C3 NH3 measured by a continuous monitoring mechanism for flue gas emission before denitration CEMS3, a chimney exhaust flue gas flow V4, a NOx content C4 NOx and a moisture content C4 H2O measured by a continuous monitoring mechanism for flue gas emission of a chimney CEMS4, and an environmental protection requirement NOx emission concentration C NOx and an environmental protection escape ammonia emission requirement C NH3 , which are arranged between a low-temperature CO-removing device (2) and an ultra-low-temperature denitration device (3), by: V2 NH3 =[V3×C3 NOx ×(1-C3 H2O )-V4×C NOx ×(1-C4 H2O )]×10 -6 ×22.4/46-[V3×C3 NH3 -V4×C NH3 ]×10 -6 ×22.4/17; The two-stage ammonia flow regulating valve (802) is regulated by the cooperative controller (9), so that the flow measured by the two-stage ammonia flowmeter (801) is equal to the two-stage ammonia injection quantity set value V2 NH3 .

Description

Flue gas desulfurization, CO removal and denitration cooperative treatment system and control method thereof Technical Field The invention belongs to the technical field of atmospheric pollutant treatment, relates to the technology of purifying atmospheric pollutants SO 2, CO and NOx, and in particular relates to a flue gas desulfurization, CO and denitration cooperative treatment system and a control method thereof. Background At present, the flue gas discharged by industry usually contains various pollutants such as sulfur dioxide, nitrogen oxides, carbon monoxide and the like, and the flue gas can be discharged after reaching standards through cooperative treatment. The traditional comprehensive treatment process of the flue gas mostly adopts a combined technology of desulfurization and SCR denitration, and is widely applied. However, this process has the following disadvantages in practical applications: The high-efficiency reaction temperature range of the conventional SCR denitration catalyst is generally 200-400 ℃, and the temperature of flue gas is generally reduced to below 100 ℃ after wet desulfurization or semi-dry desulfurization, so that the temperature requirement of SCR denitration cannot be directly met. In order to raise the flue gas temperature, the prior art generally needs to provide a flue gas reheater, a hot blast stove, an electric heater and other heat supplementing devices, or a GGH flue gas heat exchanger to recover waste heat. This not only results in high system investment and large occupied area, but also significantly increases the energy consumption and running cost of the wind turbine. Especially under the current large trend of energy conservation and carbon reduction, the concurrent heating or configuring of the GGH can consume a large amount of fuel and electric energy, and increase the carbon emission pressure. Meanwhile, the heat exchange equipment such as GGH is easy to cause the problems of blockage, corrosion, leakage and the like, the failure rate and maintenance difficulty of the system are improved, and the stability and reliability of the flue gas treatment system are reduced. The existing low-temperature denitration technology can be operated at a lower temperature, but most of the low-temperature denitration technology does not fully utilize the reaction heat of the components of the flue gas, and still depends on an external heat source or a complex heat exchange system, so that low-energy consumption and self-balancing operation are difficult to realize. CO in the flue gas releases a large amount of heat in the catalytic oxidation removal process, and the temperature of the flue gas can be raised by about 6-7 ℃ when 1000mg/m 3 of CO is removed. However, this heat has not been directly used to provide the required temperature rise for the denitration unit in the current technology, resulting in energy waste. In addition, the CO catalytic oxidation catalyst is highly sensitive to SO 2 and moisture in flue gas, is easy to poison and deactivate due to the increase of the moisture and SO 2 content, but the poisoned catalyst can recover the activity after being regenerated at high temperature. Chinese patent application CN118987964a discloses a combined device for desulfurizing, decarbonizing and denitrating. The method adopts a medium-high Wen Tuoxiao, and utilizes a heat supplementing system for regenerating active coke to supplement heat for CO removal and denitration processes, and simultaneously configures GGH for heat exchange, and the problem of on-line regeneration of a CO removal catalyst is not considered. Chinese patent CN222694429U discloses a device for removing CO before denitration and ammonia injection of sintering flue gas. The patent also needs to adopt GGH for heat exchange, and is provided with a heat supplementing system for heating, and the operation of the CO removal catalyst under the regeneration working condition is not considered. Chinese patent application CN118416690a discloses a system and method for removing CO from sintering flue gas. The flue gas is desulfurized by a semi-dry method, and after the desulfurized flue gas is subjected to GGH heat exchange, CO removal and SCR denitration are sequentially carried out. The method utilizes heat generated by CO removal, but the CO removal temperature is required to be higher than 180 ℃ and the denitration temperature is required to be higher than 200 ℃, and the flue gas temperature after semi-dry desulfurization is usually lower than 100 ℃, so that a large amount of fuel is still required to be consumed for heat compensation. In addition, the SO 2 content after semi-dry desulfurization in actual production is generally more than 30mg/m 3, and the semi-dry process technology can increase the moisture content in flue gas and seriously affect the service life of the CO removal catalyst. Chinese patent application CN112403232a discloses a flue gas multi-pollutant synergistic purification process