System and method for removing ammonium sulfate compound by SCR (selective catalytic reduction) flue gas denitration process

Abstract

The invention discloses a system and a method for removing ammonium sulfate compounds by an SCR (selective catalytic reduction) flue gas denitration process, and relates to the technical field of environmental protection engineering, the system comprises an SCR reaction tower, a system state monitoring system, a circulating air system, a power system and a centralized control system, the SCR reaction tower performs denitration reaction on flue gas entering the SCR reaction tower; the circulating air system is used for receiving the gas after denitration by the SCR reaction tower and inputting the heated gas into the SCR reaction tower for cleaning and heating the interior of the SCR reaction tower. The system can solve the problems of catalyst deactivation and system resistance increase caused by adhesion of the ammonium sulfate compound to the surface of the catalyst in the SCR flue gas denitration technology, realizes effective removal of the ammonium sulfate compound and dust particles through cooperation of the system state monitoring system, the circulating air system and the centralized control system, recovers the activity of the catalyst, and improves the denitration efficiency. The denitration efficiency is improved, and the equipment blockage risk is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of environmental protection engineering, and in particular to a system and method for removing ammonium sulfate compounds through an SCR flue gas denitration process. Background Art

[0002] Selective catalytic reduction (SCR) flue gas denitrification technology is recognized as the most effective technology for controlling NOx emissions. It has the advantages of high denitrification efficiency, stable and reliable operation, and simple and convenient maintenance. It is widely used in flue gas treatment in thermal power plants, cement kilns and other industrial fields.

[0003] However, it was found in actual use that when the flue gas passes through the SCR reactor, the SCR catalyst therein will catalytically oxidize part of the sulfur dioxide (SO2) in the flue gas, and the sulfur trioxide (SO3) generated by the catalytic oxidation process will react with the ammonia (NH3) escaping during the denitrification process to form ammonium sulfate compounds; ammonium sulfate compounds are sticky, corrosive and hygroscopic. In the temperature range of 150 to 220°C, ammonium sulfate compounds are a highly viscous liquid substance. In the medium and low temperature SCR denitrification process, it is very easy to condense and adhere to the surface of the SCR catalyst, and adhere to the fly ash particles in the flue gas, blocking the catalyst channel, resulting in the SCR catalyst and flue gas contact area reduction and deactivation, and the reaction tower resistance increased, affecting the denitrification efficiency.

[0004] Therefore, how to remove ammonium sulfate compounds and restore catalyst activity is of great significance to the emission of nitrogen oxides in SCR flue gas denitrification; to this end, a system and method for removing ammonium sulfate compounds in an SCR flue gas denitrification process are proposed. Summary of the invention

[0005] The object of the present invention is to provide a system and method for removing ammonium sulfate compounds in an SCR flue gas denitrification process to solve the problems raised in the above background technology.

[0006] To achieve the above object, the present invention provides the following technical solution: a system for removing ammonium sulfate compounds by an SCR flue gas denitrification process, comprising an SCR reaction tower, a system status monitoring system, a circulating air system, a power system, and a centralized control system:

[0007] An SCR reaction tower, wherein the SCR reaction tower performs a denitrification reaction on the flue gas entering therein and discharges the gas after the denitrification reaction;

[0008] A circulating air system, wherein the circulating air system receives and heats the gas depleted by the SCR reaction tower and the outside air, and inputs the heated mixed gas into the SCR reaction tower to clean and heat the inside of the SCR reaction tower;

[0009] A power system, which provides the power required for the flue gas to be transported in the SCR reaction tower and the circulating air system;

[0010] A system status monitoring system, which is used to monitor various determination data within the system and feed the monitoring data back to the centralized control system;

[0011] A centralized control system receives data fed back by a system status monitoring system and controls the automatic operation of the circulating air system according to preset logic.

[0012] Preferably, the reaction tower comprises a tower body, a rectifying layer, an SCR reactor and a catalyst layer;

[0013] The rectifying layer, the catalyst layer and the SCR reactor are sequentially installed in the tower body from top to bottom at intervals, wherein the catalyst layer is multiple and vertically stacked at intervals.

[0014] Preferably, the circulating air system includes a residual heat exchange device, a heating and temperature raising device and a rake-type purge component, and the rake-type purge component is located above the catalyst layer;

[0015] The power system includes a high-pressure blower, which is used to provide power for gas transmission;

[0016] A pipeline assembly is provided between the circulating air system and the SCR reaction tower, and the SCR reaction tower is connected to the circulating air system through the pipeline assembly.

[0017] Preferably, the pipeline assembly includes a gas delivery pipeline, the high-pressure fan is connected to the rake-type purge assembly through the gas delivery pipeline, an electric butterfly valve 1 is installed at the top inlet of the SCR reaction tower, a gas pipeline and a liquid pipeline are respectively provided between the SCR reaction tower and the residual heat exchange equipment, an electric butterfly valve 2 is installed on the liquid pipeline, an electric valve 1 is installed on the gas pipeline, an electric valve 2 is installed at the air inlet of the residual heat exchange equipment, the electric valve 1 and the electric valve 2 are connected in parallel, and the gas outlet of the residual heat exchange equipment is connected to the air inlet of the high-pressure fan through a pipeline;

[0018] The heating and temperature raising device is connected in parallel with the gas delivery pipeline through a pipeline, and an electric valve three is installed at the air inlet position of the heating and temperature raising device, and an electric valve four is installed on the gas delivery pipeline, and the electric valve three and the electric valve four are connected in parallel.

[0019] Preferably, the system status monitoring system includes a pressure detection unit, a temperature detection unit and a CEMS system;

[0020] The pressure detection unit monitors the pressure values ​​at the inlet and outlet of the SCR reaction tower, and calculates the resistance of the SCR reaction tower according to the pressure difference for judgment and control;

[0021] The temperature detection unit monitors the temperature in the SCR reaction tower and the circulating air system;

[0022] The CEMS system is installed at the outlet of the residual heat exchange equipment, and the CEMS system monitors the gas composition and content at the gas outlet of the residual heat exchange equipment.

[0023] Preferably, the pressure detection unit comprises a first pressure transmitter and a second pressure transmitter, wherein the first pressure transmitter is installed at an inlet position at the top of the SCR reaction tower, and the second pressure transmitter is installed at an outlet position at the bottom of the SCR reaction tower.

[0024] Preferably, the temperature detection unit includes temperature transmitter 1, temperature transmitter 2 and temperature transmitter 3. The temperature transmitter 1 is installed on the pipeline between the residual heat exchange equipment and the high-pressure fan, and is used to monitor the temperature value of the exhaust gas in the residual heat exchange equipment. The temperature transmitter 2 is installed on the pipeline between the electric valve 4 and the electric valve 5, and is used to monitor the temperature value of the gas entering the rake purge assembly. The temperature transmitter 3 is installed at the bottom of the SCR reaction tower, and is used to monitor the temperature value of the exhaust gas from the SCR reaction tower.

[0025] On the other hand, the present invention also provides a method for removing ammonium sulfate compounds in an SCR flue gas denitration process, comprising the following steps:

[0026] Step 1: The pressure value P monitored by the pressure transmitter 1 and the pressure value P monitored by the pressure transmitter 2 in the pressure detection unit of the system status monitoring system are fed back to the centralized control system, and the centralized control system processes the pressure value P and the pressure value P to obtain the difference P between the two. At the same time, the centralized control system receives the nitrogen oxide concentration monitored by the CEMS system and;

[0027] Step 2: The centralized control system compares the pressure difference P and the nitrogen oxide concentration value monitored by the CEMS system with the set value. When PP ≥ the set value, and the nitrogen oxide emission concentration value monitored by the CEMS is greater than the set value, the thiamine compound removal process is performed;

[0028] Step three: when the nitrogen oxide emission concentration value monitored by CEMS is ≤ the set value, the dust cleaning process is carried out.

[0029] Preferably, in step 2, the process for removing the ammonium sulfate compound is specifically as follows:

[0030] Electric butterfly valve 1, electric butterfly valve 2, electric valve 2 and electric valve 4 are closed, electric valve 1 and electric valve 3 are opened, and the high-pressure fan and residual heat exchange equipment are started;

[0031] The gas discharged from the SCR reaction tower enters the residual heat exchange device to be heated, and then is sent to the heating and temperature-raising device through a high-pressure fan to be further heated until the gas temperature reaches the set temperature range. The heated gas enters the rake purge assembly and is discharged to the catalyst layer in the SCR reaction tower, so as to purge and heat the catalyst layer and remove the ammonium sulfate compounds.

[0032] Preferably, in step three, the dust removal process is specifically as follows:

[0033] When PP≥set value, electric butterfly valve 1, electric valve 1 and electric valve 3 are closed, electric butterfly valve 2, electric valve 2, electric valve 4 and electric valve 5 are opened, the high-pressure fan is started, and the external gas enters the residual heat exchange device to be heated, and then passes through the high-pressure fan through electric valve 4 and electric valve 5 into the rake-type purge assembly and is sprayed out to the catalyst layer, and the dust on the catalyst layer is removed by wind power;

[0034] When PP is less than the set value, electric valve 1, electric valve 2, electric valve 3, electric valve 4, electric valve 5, high-pressure fan and heating equipment are closed, electric butterfly valve 1 and electric butterfly valve 2 are opened, and the circulating air system is closed.

[0035] Compared with the prior art, the system and method for removing ammonium sulfate compounds by the SCR flue gas denitrification process provided by the present invention has the following technical effects:

[0036] The present invention can solve the problems of catalyst deactivation and increased system resistance caused by the adhesion of ammonium sulfate compounds to the catalyst surface in the SCR flue gas denitrification technology. Through the cooperation of the system status monitoring system, the circulating air system and the centralized control system, the ammonium sulfate compounds and dust particles are effectively removed, the catalyst activity is restored, the denitrification efficiency is improved, and the risk of equipment blockage is reduced, which is of great significance to environmental protection and industrial production. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 It is a schematic diagram of the structure of the system for removing ammonium sulfate compounds by the SCR flue gas denitrification process of the present invention.

[0038] In the figure: 101, tower body; 102, rectifying layer; 103, SCR reactor; 104, catalyst layer; 105, rake purge assembly; 200, residual heat exchange equipment; 300, heating and temperature raising equipment; 400, high-pressure fan. DETAILED DESCRIPTION

[0039] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0040] The present invention provides Figure 1 A system for removing ammonium sulfate compounds by an SCR flue gas denitrification process is shown, comprising:

[0041] SCR reaction tower, the SCR reaction tower performs a denitrification reaction on the flue gas entering therein, and discharges the gas after the denitrification reaction. The reaction tower includes a tower body 101, a rectifying layer 102, an SCR reactor 103 and a catalyst layer 104. The rectifying layer 102, the catalyst layer 104 and the SCR reactor 103 are sequentially installed in the tower body 101 from top to bottom, wherein the catalyst layers 104 are multiple and vertically stacked; the catalyst layers 104 are generally arranged in three groups, and the catalyst layer 104 located at the topmost position in the tower body 101 is used as a backup, so that when the other two groups of catalyst layers 104 fail The spare one can be used directly to ensure the normal operation of the system. The rectifier 102 mainly improves the uniform distribution of the flow field, which not only helps to improve the denitrification efficiency and reduce environmental pollution, but also prolongs the service life of the catalyst layer 104, ensuring the long-term stable operation of the SCR reaction tower; the SCR reactor 103 is based on the selective catalytic reduction method (SCR method), and through the action of the catalyst layer 104, it accelerates the chemical reaction between the reducing agent (ammonia) and the NOx in the flue gas to generate harmless nitrogen and water vapor; the catalyst layer 104 generally selects any one of the vanadium-titanium-based catalyst and the tungsten-titanium-based catalyst;

[0042] A circulating air system, a pipeline assembly is provided between the circulating air system and the SCR reaction tower, the SCR reaction tower is connected to the circulating air system through the pipeline assembly, the circulating air system receives the gas and the outside air after the SCR reaction tower is depleted and heats them, and inputs the heated mixed gas into the SCR reaction tower for cleaning and heating inside the SCR reaction tower, the circulating air system includes a residual heat exchange device 200, a heating and temperature raising device 300 and a rake-type purge assembly 105, the residual heat exchange device 200 added to the circulating air system can utilize the residual heat of the flue gas to preheat the back-blowing gas to avoid damage caused by supercooled air entering the SCR reaction tower, the rake-type purge assembly 105 is located above the catalyst layer 104, the rake-type purge assembly 105 is a prior art, and the specific composition is not described here, and the motor in the rake-type purge assembly 102 is used to drive the forward and reverse rotation of the catalyst layer 104. , the back-blowing pipe is driven to reciprocate through the screw drive, so that the catalyst layer 104 can be purged and heated at a close distance, which can help decompose and remove the ammonium sulfate compounds adhering to the surface of the catalyst layer 104, restore the sparks of the catalyst layer 104, and thus reduce the risk of clogging of the catalyst layer 104. The gas entering the rake-type purge assembly 105 is kept at a preset temperature to purge the catalyst layer 104 by utilizing the residual temperature of the purified flue gas and the heating effect of the heating and heating equipment 300, so that the gas entering the rake-type purge assembly 105 is maintained at a preset temperature to purge the catalyst layer 104, and the wind power and temperature can be used to clean the surface of the catalyst layer 104 and decompose the ammonium sulfate compounds; in addition, the heating and heating equipment 300 can also achieve the purpose of rapid heating in the SCR reaction tower by heating the air, so that the temperature in the SCR reaction tower rises quickly, and the SCR reaction tower is prevented from being easily damaged due to excessively low temperature;

[0043] The power system includes a high-pressure blower 400. The power system provides the power required for the flue gas to be transported in the SCR reaction tower and the circulating air system. The high-pressure blower 400 can be used to pressurize the gas for transmission, thereby ensuring the power for gas transmission;

[0044] System status monitoring system, the system status monitoring system is used to monitor various judgment data in the system and feed back the monitoring data to the centralized control system. The system status monitoring system includes a pressure detection unit, a temperature detection unit and a CEMS system (continuous emission monitoring system). The pressure detection unit monitors the pressure values ​​at the inlet and outlet of the SCR reaction tower, and calculates the resistance of the SCR reaction tower according to the pressure difference for judgment and control; the temperature detection unit monitors the temperature in the SCR reaction tower and the circulating air system; the CEMS system is installed at the outlet position of the residual heat exchange equipment 200, and the CEMS system monitors the gas composition and content at the gas outlet of the residual heat exchange equipment 200. The CEMS system is mainly used for the concentration value of nitrogen oxides in the flue gas discharged from the outlet of the residual heat exchange equipment 200, and assists in the judgment and control of the circulating air system, and then cooperates with the pressure detection unit and the temperature detection unit to monitor the pressure value and temperature value of the corresponding position respectively, so as to facilitate the judgment and control of the circulating air system;

[0045] Centralized control system: The centralized control system receives data fed back by the system status monitoring system and controls the automatic operation of the circulating air system according to the preset logic. The centralized control system can be controlled by a PLC that meets the use requirements in the existing technology. It can receive temperature values, pressure values, gas composition and content and control the circulation air system according to the preset logic to realize the automatic operation of the system, which helps to improve the operation efficiency of the system.

[0046] Furthermore, the pipeline assembly includes a gas delivery pipeline, and the high-pressure fan 400 is connected to the rake purge assembly 105 through the gas delivery pipeline. An electric butterfly valve 1 is installed at the top inlet of the SCR reaction tower, and the start and stop of the SCR reaction tower inlet is controlled by the electric butterfly valve 1. A gas pipeline and a liquid pipeline are respectively provided between the SCR reaction tower and the residual heat exchange equipment 200. An electric butterfly valve 2 is installed on the liquid pipeline. The electric butterfly valve 2 cooperates with the liquid pipeline to transport and discharge impurities after the purge treatment. An electric valve 1 is installed on the gas pipeline, and an electric valve 2 is installed at the air inlet of the residual heat exchange equipment 200. The electric valve 1 and the electric valve 2 are connected in parallel. The gas outlet of the residual heat exchange equipment 200 and the air inlet of the high-pressure fan 400 are connected through a pipeline. Connected; the heating and heating device 300 is connected in parallel with the gas delivery pipeline through a pipeline, and an electric valve three is installed at the air inlet position of the heating and heating device 300, and an electric valve four is installed on the gas delivery pipeline, and the electric valve three and the electric valve four are connected in parallel, the heating and heating device 300 is connected in parallel with the gas delivery pipeline, and the two routes are separately controlled by the electric valve three and the electric valve four, and the corresponding transmission route can be selected according to the gas temperature value, so that when the gas temperature value after heat exchange by the residual heat exchange device 200 does not reach the set value, the heating and heating device 300 can be used for auxiliary heating to ensure that the gas can reach the preset temperature and enter the rake purge assembly 105 to perform the purging and temperature decomposition operations of the catalyst layer 104.

[0047] Among them, the pressure detection unit includes pressure transmitter 1 and pressure transmitter 2. Pressure transmitter 1 is installed at the top inlet position of the SCR reaction tower, and pressure transmitter 2 is installed at the bottom outlet position of the SCR reaction tower. Pressure transmitter 1 and pressure transmitter 2 respectively monitor the pressure values ​​of the inlet and outlet of the SCR reaction tower, so as to calculate the pressure difference between the inlet and outlet of the SCR reaction tower. The resistance of the SCR reaction tower can be calculated according to the pressure difference, which is used to determine the action of the circulating air system; the temperature detection unit includes temperature transmitter 1, temperature transmitter 2 and temperature transmitter 3. Temperature transmitter 1 is installed on the pipeline between the residual heat exchange equipment 200 and the high-pressure fan 400 to monitor the temperature value of the exhaust gas in the residual heat exchange equipment 200. Temperature transmitter 2 is installed on the electric valve The pipeline between door four and electric valve five is used to monitor the temperature value of the gas entering the rake purge assembly 105. Temperature transmitter three is installed at the bottom of the SCR reaction tower to monitor the temperature value of the gas discharged from the SCR reaction tower. Through the cooperation of temperature transmitter one and temperature transmitter two, the temperature value of the gas discharged from the residual heat exchange device 200 and the temperature value of the gas discharged from the heating and temperature raising device 300 are monitored separately, so that it is possible to choose whether to perform auxiliary heating and temperature raising according to the gas temperature value, avoid unnecessary energy consumption loss, help reduce costs, and achieve energy conservation and environmental protection. Temperature transmitter three is used to monitor the temperature inside the SCR reaction tower to ensure that the temperature inside the SCR reaction tower is kept constant and avoid malfunction and damage caused by too low temperature inside the tower.

[0048] On the other hand, based on the above-mentioned system for removing ammonium sulfate compounds by the SCR flue gas denitration process, a method for removing ammonium sulfate compounds by the SCR flue gas denitration process comprises the following steps:

[0049] Step 1: The pressure value P1 monitored by the pressure transmitter 1 and the pressure value P2 monitored by the pressure transmitter 2 in the pressure detection unit of the system status monitoring system are fed back to the centralized control system, and the centralized control system processes the pressure value P1 and the pressure value P2 to obtain the difference P between the two. At the same time, the centralized control system receives the nitrogen oxide concentration monitored by the CEMS system and;

[0050] Step 2: The centralized control system compares the pressure difference P and the nitrogen oxide concentration value monitored by the CEMS system with the set value. When P2-P1≥the set value, and the nitrogen oxide emission concentration value monitored by the CEMS is greater than the set value, the thiamine compound removal process is performed;

[0051] Step three: when the nitrogen oxide emission concentration value monitored by CEMS is ≤ the set value, the dust cleaning process is carried out.

[0052] In step 2, the process for removing the ammonium sulfate compound is specifically as follows:

[0053] The electric butterfly valve 1, the electric butterfly valve 2, the electric valve 2 and the electric valve 4 are closed, the electric valve 1 and the electric valve 3 are opened, and the high-pressure fan 400 and the residual heat exchange device 200 are started;

[0054] The gas exhausted from the SCR reaction tower enters the residual heat exchange device 200 to be heated and then is sent to the heating and temperature-raising device 300 through the high-pressure fan 400 to be further heated until the gas temperature reaches the set temperature range. The heated gas enters the rake purge assembly 105 and is discharged to the catalyst layer 104 in the SCR reaction tower, so as to purge and heat the catalyst layer 104 and remove the ammonium sulfate compound.

[0055] In step three, the dust removal process is specifically as follows:

[0056] When P2-P1≥set value, electric butterfly valve 1, electric valve 1 and electric valve 3 are closed, electric butterfly valve 2, electric valve 2, electric valve 4 and electric valve 5 are opened, high-pressure fan 400 is started, external gas enters residual heat exchange device 200 to be heated, and then passes through high-pressure fan 400, electric valve 4 and electric valve 5, enters rake purge assembly 105 and is sprayed toward catalyst layer 104, and dust on catalyst layer 104 is removed by wind power;

[0057] When P2-P1 is less than the set value, electric valve 1, electric valve 2, electric valve 3, electric valve 4, electric valve 5, high-pressure fan 400 and heating and heating equipment 300 are closed, electric butterfly valve 1 and electric butterfly valve 2 are opened, and the circulating air system is closed.

[0058] Finally, it should be noted that the above is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, it is still possible for those skilled in the art to modify the technical solutions described in the aforementioned embodiments or to make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A system for removing ammonium sulfate compounds by an SCR flue gas denitrification process, characterized in that: Including SCR reaction tower, system status monitoring system, circulating air system, power system, centralized control system: An SCR reaction tower, wherein the SCR reaction tower performs a denitrification reaction on the flue gas entering therein and discharges the gas after the denitrification reaction; A circulating air system, wherein the circulating air system receives and heats the gas depleted by the SCR reaction tower and the outside air, and inputs the heated mixed gas into the SCR reaction tower to clean and heat the inside of the SCR reaction tower; A power system, which provides the power required for the transportation of flue gas in the SCR reaction tower and the circulating air system; A system status monitoring system, which is used to monitor various determination data within the system and feed the monitoring data back to the centralized control system; A centralized control system receives data fed back by a system status monitoring system and controls the automatic operation of the circulating air system according to preset logic.

2. A system for removing ammonium sulfate compounds by an SCR flue gas denitrification process according to claim 1, characterized in that: The reaction tower comprises a tower body (101), a rectifying layer (102), an SCR reactor (103) and a catalyst layer (104); The rectifying layer (102), the catalyst layer (104) and the SCR reactor (103) are installed in sequence from top to bottom in the interior of the tower body (101) at intervals, wherein the catalyst layer (104) is multiple and vertically stacked at intervals.

3. A system for removing ammonium sulfate compounds by an SCR flue gas denitrification process according to claim 2, characterized in that: The circulating air system comprises a residual heat exchange device (200), a heating and temperature raising device (300) and a rake-type purge component (105), wherein the rake-type purge component (105) is located above the catalyst layer (104); The power system comprises a high-pressure blower (400), and the high-pressure blower (400) is used to provide power for gas transmission; A pipeline assembly is provided between the circulating air system and the SCR reaction tower, and the SCR reaction tower is connected to the circulating air system through the pipeline assembly.

4. A system for removing ammonium sulfate compounds by an SCR flue gas denitrification process according to claim 3, characterized in that: The pipeline assembly comprises a gas delivery pipeline, the high-pressure blower (400) is connected to the rake-type purge assembly (105) through the gas delivery pipeline, an electric butterfly valve 1 is installed at the top inlet of the SCR reaction tower, a gas pipeline and a liquid pipeline are respectively provided between the SCR reaction tower and the residual heat exchange device (200), an electric butterfly valve 2 is installed on the liquid pipeline, an electric valve 1 is installed on the gas pipeline, an electric valve 2 is installed at the air inlet of the residual heat exchange device (200), the electric valve 1 and the electric valve 2 are connected in parallel, and the gas outlet of the residual heat exchange device (200) is connected to the air inlet of the high-pressure blower (400) through a pipeline; The heating and temperature raising device (300) is connected in parallel with the gas delivery pipeline via a pipeline, and an electric valve three is installed at the air inlet position of the heating and temperature raising device (300), and an electric valve four is installed on the gas delivery pipeline, and the electric valve three and the electric valve four are connected in parallel.

5. A system for removing ammonium sulfate compounds by an SCR flue gas denitration process according to claim 4, characterized in that: The system status monitoring system includes a pressure detection unit, a temperature detection unit and a CEMS system; The pressure detection unit monitors the pressure values ​​at the inlet and outlet of the SCR reaction tower, and calculates the resistance of the SCR reaction tower according to the pressure difference for judgment and control; The temperature detection unit monitors the temperature in the SCR reaction tower and the circulating air system; The CEMS system is installed at the outlet position of the residual heat exchange device (200), and the CEMS system monitors the gas composition and content at the gas outlet of the residual heat exchange device (200).

6. A system for removing ammonium sulfate compounds by an SCR flue gas denitrification process according to claim 5, characterized in that: The pressure detection unit includes a pressure transmitter 1 and a pressure transmitter 2. The pressure transmitter 1 is installed at the top inlet position of the SCR reaction tower, and the pressure transmitter 2 is installed at the bottom outlet position of the SCR reaction tower.

7. A system for removing ammonium sulfate compounds by an SCR flue gas denitrification process according to claim 6, characterized in that: The temperature detection unit comprises a temperature transmitter 1, a temperature transmitter 2 and a temperature transmitter 3. The temperature transmitter 1 is installed on the pipeline between the residual heat exchange device (200) and the high-pressure blower (400) and is used to monitor the temperature value of the exhaust gas in the residual heat exchange device (200). The temperature transmitter 2 is installed on the pipeline between the electric valve 4 and the electric valve 5 and is used to monitor the temperature value of the gas entering the rake purge assembly (105). The temperature transmitter 3 is installed at the bottom of the SCR reaction tower and is used to monitor the temperature value of the exhaust gas from the SCR reaction tower.

8. The method for removing ammonium sulfate compounds by an SCR flue gas denitrification process according to claim 7, characterized in that: The following steps are involved: Step 1: The pressure value P1 monitored by the pressure transmitter 1 and the pressure value P2 monitored by the pressure transmitter 2 in the pressure detection unit of the system status monitoring system are fed back to the centralized control system, and the centralized control system processes the pressure value P1 and the pressure value P2 to obtain the difference P between the two. At the same time, the centralized control system receives the nitrogen oxide concentration monitored by the CEMS system and; Step 2: The centralized control system compares the pressure difference P and the nitrogen oxide concentration value monitored by the CEMS system with the set value. When P2-P1≥the set value, and the nitrogen oxide emission concentration value monitored by the CEMS is greater than the set value, the thiamine compound removal process is performed; Step three: when the nitrogen oxide emission concentration value monitored by CEMS is ≤ the set value, the dust cleaning process is carried out.

9. A system and method for removing ammonium sulfate compounds by an SCR flue gas denitrification process according to claim 8, characterized in that: In the step 2, the process for removing the ammonium sulfate compound is specifically as follows: The electric butterfly valve 1, the electric butterfly valve 2, the electric valve 2 and the electric valve 4 are closed, the electric valve 1 and the electric valve 3 are opened, and the high-pressure fan (400) and the residual heat exchange device (200) are started; The gas discharged from the SCR reaction tower enters the residual heat exchange device (200) to be heated, and then is sent to the heating and temperature raising device (300) through the high-pressure fan (400) to be further heated until the gas temperature reaches the set temperature range. The heated gas enters the rake purge assembly (105) and is discharged to the catalyst layer (104) in the SCR reaction tower, so as to purge and heat the catalyst layer (104) and remove the ammonium sulfate compound.

10. The system and method for removing ammonium sulfate compounds by SCR flue gas denitration process according to claim 8, characterized in that: In step 3, the dust removal process is specifically as follows: When P2-P1≥the set value, the electric butterfly valve 1, the electric valve 1 and the electric valve 3 are closed, the electric butterfly valve 2, the electric valve 2, the electric valve 4 and the electric valve 5 are opened, the high-pressure fan (400) is started, the external gas enters the residual heat exchange device (200) to be heated, and then passes through the high-pressure fan (400) through the electric valve 4 and the electric valve 5 to enter the rake-type purge assembly (105) and is sprayed toward the catalyst layer (104), and the dust on the catalyst layer (104) is removed by wind power; When P2-P1 is less than the set value, the electric valve 1, the electric valve 2, the electric valve 3, the electric valve 4, the electric valve 5, the high-pressure fan (400) and the heating and temperature raising device (300) are closed, the electric butterfly valve 1 and the electric butterfly valve 2 are opened, and the circulating air system is closed.

Images