Flue gas purification system and control method of semi-dry deacidification synergistic catalytic filter bag dust and saltpeter integrated device

Abstract

The present invention relates to the technical field of flue gas purification, and specifically to a flue gas purification system and control method for a semi-dry deacidification coordinated catalytic filter bag dust and saltpeter integrated device. Using the flue gas purification system of the semi-dry deacidification coordinated catalytic filter bag dust and saltpeter integrated device of the present invention, the flue gas at the outlet of the incinerator first enters the semi-dry deacidification tower for deacidification, and then the flue gas temperature at the outlet of the semi-dry deacidification tower is heated to a temperature range where the baking soda dry deacidification and catalytic filter bag have better effects through a steam heat exchanger. The baking soda dry deacidification solves the problem of SOx (SO 2 、SO 3 ) The concentration exceeds the tolerance limit of the catalytic filter bag, reducing the risk of sulfur poisoning of the SCR catalyst in the catalytic filter bag and the generation of ammonium bisulfate in the catalytic filter bag. At the same time, the generated ammonium bisulfate is decomposed by the catalytic filter bag regeneration system, which increases the service life of the catalytic filter bag and improves the stability of the flue gas purification system.

Description

Technical Field

[0001] The invention relates to the technical field of flue gas purification, and in particular to a flue gas purification system and a control method of a semi-dry deacidification coordinated catalytic filter bag dust and saltpeter integrated device. Background Art

[0002] In recent years, some provinces and cities have issued corresponding local standards for the emission limits of flue gas pollutants from the incineration of domestic waste, which are higher than the national standards. For example, Shenzhen requires the emission limit of nitrogen oxides to be 80mg / Nm 3 , sulfur dioxide emission limit is 30mg / Nm 3 、HCl emission limit is 8mg / Nm 3 In order to meet the above emission standards, the usual flue gas purification technology is to simply stack and connect various flue gas treatment technologies in series, resulting in a lengthy overall process flow, high raw material and energy consumption, and large investment.

[0003] In view of this, the integrated dust removal and denitrification technology has been gradually applied in the flue gas purification of domestic waste incineration. After replacing the filter bags in the original bag filter with catalytic filter bags, the integrated dust removal and denitrification can be achieved. The transformation investment is small and the cycle is short, which has a strong market application prospect. However, due to the temperature resistance limit of the filter bag material and the active temperature window of the SCR catalyst, the general operating temperature range of the catalytic filter bag is 170-250℃, and the formation of ammonium bisulfate cannot be avoided. In this temperature range, ammonium bisulfate is in liquid state and has strong viscosity. It will adhere to the surface of the catalytic filter bag and the pore structure, causing serious deactivation of the catalytic filter bag, excessive resistance of the filter bag, and the system cannot operate normally. In order to control the generation of ammonium bisulfate, on the one hand, it is necessary to reduce the SOx (SO2, SO3) entering the catalytic filter bag, that is, the deacidification process before the catalytic filter bag is required to have an extremely high desulfurization effect. However, the most commonly used SDA semi-dry desulfurization process in the current domestic waste incineration flue gas treatment process cannot meet the above requirements; on the other hand, the already generated ammonium bisulfate is usually treated by thermal decomposition, but the thermal decomposition temperature of ammonium bisulfate is above 390°C, which is far beyond the temperature resistance limit of the filter bag and cannot be used, limiting the application and promotion of catalytic filter bags. Summary of the invention

[0004] In view of the above technical problems, the present invention provides a flue gas purification system and a control method of a semi-dry deacidification and catalytic filter bag dust and saltpeter integrated device.

[0005] In order to solve the above technical problems, this application provides the following technical solutions:

[0006] A flue gas purification system of a semi-dry deacidification and catalytic filter bag dust and saltpeter integrated device, comprising an incinerator, a semi-dry deacidification tower, a steam heat exchanger, a catalytic filter bag dust and saltpeter integrated device, an external economizer, an induced draft fan, and a chimney connected in sequence through a flue;

[0007] The outlet of the steam heat exchanger is connected to a deacidifying agent injection system, the deacidifying agent injection system is connected to a deacidifying agent grinding system, and the deacidifying agent is a sodium-based deacidifying agent;

[0008] The inlet of the catalytic filter bag dust and saltpeter integrated device is connected to the SCR reducing agent preparation system; the catalytic filter bag dust and saltpeter integrated device is composed of at least two chambers, the inlet of each chamber is provided with a chamber inlet partition valve, the outlet of each chamber is provided with a chamber outlet partition valve, the inlet of each chamber is connected to the chamber regeneration inlet partition valve, the outlet of each chamber is connected to the chamber regeneration outlet partition valve, the other end of the chamber regeneration outlet partition valve is connected to the regeneration system outlet partition valve, and the other end of the regeneration system outlet partition valve is connected to the inlet of the semi-dry deacidification tower;

[0009] A regeneration system inlet valve is connected to the flue connecting the outlet of the steam heat exchanger and the inlet of the catalytic filter bag dust and saltpeter integrated device, the other end of the regeneration system inlet valve is connected to the inlet of the regeneration system dust collector, the outlet of the regeneration system dust collector is connected to the inlet of the regeneration circulation fan, the outlet of the regeneration circulation fan is connected to the inlet of the regeneration heater, the outlet of the regeneration heater is connected to the chamber regeneration inlet isolation valve, and the inlet of the regeneration circulation fan is also connected to the oxidant preparation system;

[0010] Each chamber inlet of the catalytic filter bag dust and saltpeter integrated device is provided with a chamber inlet pressure transmitter, and each chamber outlet is provided with a chamber outlet pressure transmitter; the regeneration circulation fan outlet is provided with a regeneration system NO / NO2 measuring instrument, the outlet of the regeneration heater is connected to a regeneration flue gas flow meter and a regeneration flue gas temperature meter, the outlet of the semi-dry deacidification tower is provided with an inlet CEMS, and the inlet of the chimney is provided with an outlet CEMS.

[0011] Furthermore, the deacidifying agent grinding system includes a deacidifying agent coarse powder bin, a coarse powder bin metering feeding device, a grinder and a grinder powder conveying fan connected in sequence; the deacidifying agent injection system includes a deacidifying agent fine powder bin inlet partition valve, a deacidifying agent fine powder bin, a deacidifying agent metering weighing device, a deacidifying agent powder conveying fan and a deacidifying agent powder conveying injector connected in sequence; the outlet of the grinder powder conveying fan is connected to the deacidifying agent fine powder bin inlet partition valve, and the deacidifying agent is baking soda.

[0012] Furthermore, the SCR reductant preparation system includes an ammonia water storage tank, an ammonia water delivery pump and an ammonia water atomizing spray gun connected in sequence, and the ammonia water in the ammonia water storage tank is transported to the inlet of the catalytic filter bag dust and nitrate integrated device by the ammonia water delivery pump and the ammonia water atomizing spray gun.

[0013] Furthermore, the semi-dry deacidification tower is a slaked lime SDA semi-dry deacidification tower; the outlet flue gas temperature of the semi-dry deacidification tower is 150°C~160°C, and the outlet flue gas temperature of the steam heat exchanger is 170°C~190°C.

[0014] Furthermore, the oxidant preparation system is an ozone generator, a hydrogen peroxide preparation system, a sodium hypochlorite preparation system or a sodium chlorite preparation system.

[0015] Furthermore, the regeneration heater is an electric heater; the regeneration system dust collector is a bag dust collector; and the regeneration system outlet isolation valve is a gate valve.

[0016] Based on the above-mentioned flue gas purification system of the semi-dry deacidification synergistic catalytic filter bag dust and saltpeter integrated device, the present invention also provides a flue gas purification system control method of the semi-dry deacidification synergistic catalytic filter bag dust and saltpeter integrated device, comprising the following steps:

[0017] S1, set the cleaning start differential pressure Crit_DP_1 for the catalytic filter bag dust and saltpeter integrated device chamber to perform the cleaning procedure, set the regeneration start differential pressure Crit_DP_2 for the catalytic filter bag dust and saltpeter integrated device chamber to perform the regeneration procedure, set the chamber regeneration time SV_T_Reg, and execute step S2; the cleaning start differential pressure Crit_DP_1 = 1200~2500Pa, preferably, Crit_DP_1 = 1500~1800Pa; the regeneration start differential pressure Crit_DP_2 should be between the initial operation time of the chamber The initial operation differential pressure is between 500 and 700 Pa when the catalytic filter bag installed in the chamber is brand new and is operated at the designed filtration wind speed. Preferably, Crit_DP_2=800-1000 Pa, more preferably, Crit_DP_2=850-950 Pa; the chamber regeneration time SV_T_Reg=12-48 h, preferably, SV_T_Reg=12-24 h;

[0018] S2, judging whether the measured value PV_DP of the operation differential pressure of the chamber of the catalytic filter bag dust and saltpeter integrated device is greater than or equal to the set chamber cleaning start differential pressure Crit_DP_1, when the judgment result is "yes", executing step S3, when the judgment result is "no", executing step S11;

[0019] S3, executing the bin cleaning procedure, the bin cleaning procedure is as follows: (1) closing the bin outlet isolation valve; (2) cleaning the filter element in the bin, the cleaning method is line spray pulse cleaning or rotary pulse cleaning or box pulse cleaning; (3) opening the bin outlet isolation valve; after the bin cleaning procedure is completed, executing step S4;

[0020] S4, judging whether the measured differential pressure value PV_DP after the chamber of the catalytic filter bag dust and saltpeter integrated device is greater than or equal to the set chamber regeneration start differential pressure Crit_DP_2, when the judgment result is "yes", executing step S5, when the judgment result is "no", executing step S11;

[0021] S5. Execute the chamber regeneration startup procedure, which is as follows: (1) close the chamber inlet isolation valve; (2) close the chamber outlet isolation valve; (3) open the regeneration system inlet valve; (4) open the chamber regeneration inlet isolation valve; (5) open the chamber regeneration outlet isolation valve and the regeneration system outlet isolation valve; (6) start the regeneration circulation fan and set the flow rate SV_F_Reg of the regeneration circulation fan; (7) start the regeneration heater and set the regeneration heater outlet flue gas temperature setting value SV_Reg_Temp=230~250℃; (8) start the oxidant preparation system, Add an oxidant to the regeneration flue gas to oxidize part of the NO into NO2. The principle of adding the oxidant is that the ratio R of the molar concentration of NO to the molar concentration of NO2 in the flue gas after oxidation is between 0.7:0.3 and 0.5:0.5, that is, R=SV_mole_NO:SV_mole_NO2=0.7:0.3~0.5:0.5; (9) When the flue gas temperature PV_Reg_Temp at the outlet of the regeneration fan reaches SV_Reg_Temp and the regeneration fan flow PV_F_Reg reaches SV_F_Reg, start recording the chamber regeneration time T_Reg; Execute step S6;

[0022] S6, judging whether the chamber regeneration time T_Reg is greater than the chamber regeneration time setting value SV_T_Reg, when the judgment result is "yes", executing step S7, when the judgment result is "no", executing step S8;

[0023] S7, executing the chamber regeneration stop procedure, wherein the chamber regeneration stop procedure is: (1) shutting down the oxidant preparation system; (2) shutting down the regeneration heater; (3) shutting down the regeneration system inlet valve; (4) shutting down the chamber regeneration outlet isolation valve; (5) shutting down the chamber regeneration inlet isolation valve and the regeneration system outlet isolation valve; (6) opening the chamber outlet isolation valve; (7) opening the chamber inlet isolation valve, and executing step S9;

[0024] S8, issuing an external prompt to indicate that the chamber is undergoing regeneration, and executing step S6;

[0025] S9, judging whether the measured differential pressure value PV_DP after the chamber of the catalytic filter bag dust and saltpeter integrated device is greater than or equal to the set chamber regeneration start differential pressure Crit_DP_2, when the judgment result is "yes", executing step S11, when the judgment result is "no", executing step S10;

[0026] S10, an external alarm is issued, prompting "chamber regeneration failed!", and the operator is requested to handle it and execute step S11;

[0027] S11. Determine whether to end the automatic control. When the judgment result is "yes", end the automatic control. When the judgment result is "no", execute step S2.

[0028] Furthermore, the set value SV_F_Reg (Am 3 / h) is calculated according to the following formula:

[0029] SV_F_Reg= V×A_Fil_Ele×n_Fil_Ele×60, unit is Am 3 / h;

[0030] Wherein, V is the regeneration gas ratio (m / min), V=0.3~1.0, preferably, V=0.3~0.4;

[0031] A_Fil_Ele is the filtration area of ​​a single filter element, in m 2 ;

[0032] n_Fil_Ele is the number of filter elements installed in a single chamber.

[0033] Furthermore, the oxidant in step S5 is O3, and its addition amount F_O3 (kg / h) is determined by the following method:

[0034] ,

[0035] Where PV_NO is the NO concentration in the flue gas before adding the oxidant O3 measured by the inlet CEMS (mg / Am 3 , wet basis, actual O2);

[0036] PV_NO2 is the NO2 concentration in the flue gas before adding the oxidant O3 measured by the inlet CEMS (mg / Am 3 , wet basis, actual O2);

[0037] SV_F_Reg is the set value of the regeneration circulation fan flow (Am 3 / h);

[0038] SR is the stoichiometric ratio of the oxidant O3, that is, the ratio of the molar amount of O3 added to the molar amount of NO to be oxidized, SR = 1~1.3;

[0039] R is the ratio of the molar concentration of NO to the molar concentration of NO2 in the flue gas after oxidation, R=1~2.3.

[0040] Furthermore, the amount of the oxidant added can also be determined by the NO concentration (mg / Am 3 , wet basis, actual O2), NO2 concentration (mg / Am 3 , wet basis, actual O2) to perform PID automatic control to ensure that the ratio of the molar concentration of NO to the molar concentration of NO2 in the flue gas after the addition of oxidant is R.

[0041] Furthermore, when multiple chambers need to be regenerated simultaneously in step S4, an external prompt is issued, and the operator determines the order of chamber regeneration.

[0042] Compared with the prior art, the flue gas purification system and control method of the semi-dry deacidification synergistic catalytic filter bag dust and saltpeter integrated device of the present invention have at least the following beneficial effects:

[0043] (1) In the flue gas purification system of the semi-dry deacidification and catalytic filter bag dust and nitrate integrated device provided by the present invention, the flue gas at the outlet of the incinerator first enters the semi-dry deacidification tower for deacidification, and then the flue gas temperature at the outlet of the semi-dry deacidification tower is heated to a temperature range where the baking soda dry deacidification and catalytic filter bag have better effects through a steam heat exchanger. The baking soda dry deacidification solves the problem that the SOx (SO2, SO3) concentration at the outlet of the semi-dry deacidification tower exceeds the tolerance limit of the catalytic filter bag, reduces the risk of sulfur poisoning of the SCR catalyst in the catalytic filter bag and the generation of ammonium bisulfate in the catalytic filter bag, and at the same time, the generated ammonium bisulfate is decomposed by the catalytic filter bag regeneration system, thereby increasing the service life of the catalytic filter bag and improving the stability of the flue gas purification system.

[0044] (2) Due to the adoption of the flue gas purification device and method of the semi-dry deacidification and catalytic filter bag dust and nitrate integrated device, the existing semi-dry deacidification tower can continue to be used for the renovation project, which greatly reduces the construction cost, construction period and renovation difficulty of the system renovation, and is conducive to the market promotion of catalytic filter bags.

[0045] (3) Even if semi-dry deacidification and baking soda dry deacidification are applied at the same time, ammonium bisulfate will still be generated in the catalytic filter bag after long-term operation due to the presence of a small amount of SOx in the flue gas at the outlet of the deacidification system and the fluctuation and failure of the operation of the deacidification system. This will cause the catalytic filter bag to become clogged and its activity to decrease. The above effects can usually be alleviated by thermal decomposition, but the thermal decomposition temperature of ammonium bisulfate is above 390°C, which is not suitable for catalytic filter bags. The present invention provides a method suitable for regenerating catalytic filter bags, which can complete the decomposition of ammonium bisulfate at a temperature that does not exceed the temperature limit of the catalytic filter bag, thereby extending the service life of the catalytic filter bag and facilitating the market promotion of the catalytic filter bag.

[0046] (4) The present invention can automatically monitor the operation of the catalytic filter bag, detect the formation of ammonium bisulfate in the catalytic filter bag at an early stage and handle it. During regeneration, there is no need to shut down the machine or take the catalytic filter bag out of the chamber, thus realizing the function of online in-situ regeneration and greatly reducing the workload of on-site maintenance.

[0047] (5) The flue gas after regeneration treatment in the system of the present invention is sent back to the inlet of the semi-dry deacidification tower and is discharged into the atmosphere after being deacidified, denitrified and dusted again, ensuring that the emission meets the relevant standards.

[0048] The flue gas purification system and control method of the semi-dry deacidification and catalytic filter bag dust and saltpeter integrated device of the present invention are further described below in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] Figure 1 It is a schematic diagram of a flue gas purification system of a semi-dry deacidification and coordinated catalytic filter bag dust and saltpeter integrated device of the present invention;

[0050] Figure 2 This is a control flow chart of the flue gas purification system of the semi-dry deacidification and catalytic filter bag dust and saltpeter integrated device of the present invention.

[0051] Among them, 1-incinerator, 2-semi-dry deacidification tower, 3-steam heat exchanger, 4-catalytic filter bag dust and nitrate integrated device, 401 / 402 / 403 / 404-catalytic filter bag dust and nitrate integrated device chamber, 411 / 412 / 413 / 414-catalytic filter bag dust and nitrate integrated device chamber inlet isolation valve, 421 / 422 / 423 / 424-catalytic filter bag dust and nitrate integrated device chamber outlet isolation valve, 431 / 432 / 433 / 434-chamber inlet pressure transmitter, 441 / 442 / 443 / 444-chamber outlet pressure transmitter, 5-external economizer, 6-induced draft fan, 7-chimney, 8-deacidifying agent coarse powder bin, 9-coarse powder bin metering feeding device, 10-grinder, 11-grinding Machine powder conveying fan, 12-deacidifying agent fine powder bin inlet isolation valve, 13-deacidifying agent fine powder bin, 14-deacidifying agent metering and weighing device, 15-deacidifying agent powder conveying fan, 16-deacidifying agent powder conveying injector, 17-ammonia storage tank, 18-ammonia delivery pump, 19-ammonia atomizing spray gun, 20-regeneration system inlet valve, 21-regeneration circulation fan, 22-regeneration heater, 23-chamber regeneration inlet isolation valve, 24-chamber regeneration outlet isolation valve, 25-inlet CEMS, 26-outlet CEMS, 27-oxidant preparation system, 28-regeneration flue gas temperature meter, 29-regeneration flue gas flow meter, 30-regeneration system dust collector, 31-regeneration system outlet isolation valve, 32-regeneration system NO / NO2 measuring instrument. DETAILED DESCRIPTION

[0052] like Figure 1 As shown, a flue gas purification system of a semi-dry acid removal and catalytic filter bag dust and nitrate integrated device comprises an incinerator 1, a semi-dry acid removal tower 2, a steam heat exchanger 3, a catalytic filter bag dust and nitrate integrated device 4, an external economizer 5, an induced draft fan 6, and a chimney 7 which are connected in sequence through a flue.

[0053] The outlet of the steam heat exchanger 3 is connected to a deacidifying agent injection system, and the deacidifying agent injection system is connected to a deacidifying agent grinding system, and the deacidifying agent is baking soda.

[0054] The inlet of the catalytic filter bag dust and saltpeter integrated device 4 is connected to the SCR reducing agent preparation system; the catalytic filter bag dust and saltpeter integrated device 4 is composed of four chambers 401 / 402 / 403 / 404, the inlets of the four chambers are respectively provided with chamber inlet partition valves 411 / 412 / 413 / 414, the outlets of the four chambers are respectively provided with chamber outlet partition valves 421 / 422 / 423 / 424, the inlet of each chamber is connected to the chamber regeneration inlet partition valve 23, the outlet of each chamber is connected to the chamber regeneration outlet partition valve 24, the other end of the chamber regeneration outlet partition valve 24 is connected to the regeneration system outlet partition valve 31, and the other end of the regeneration system outlet partition valve 31 is connected to the inlet of the semi-dry deacidification tower 2.

[0055] A regeneration system inlet valve 20 is connected to the connecting flue between the outlet of the steam heat exchanger 3 and the inlet of the catalytic filter bag dust and saltpeter integrated device 4. The other end of the regeneration system inlet valve 20 is connected to the inlet of the regeneration system dust collector 30. The outlet of the regeneration system dust collector 30 is connected to the inlet of the regeneration circulation fan 21. The outlet of the regeneration circulation fan 21 is connected to the inlet of the regeneration heater 22. The outlet of the regeneration heater 22 is connected to the chamber regeneration inlet isolation valve 23. The inlet of the regeneration circulation fan 21 is also connected to the oxidant preparation system 27.

[0056] The four chamber inlets of the catalytic filter bag dust and saltpeter integrated device 4 are respectively provided with chamber inlet pressure transmitters 431 / 432 / 433 / 434, and the four chamber outlets are provided with chamber outlet pressure transmitters 441 / 442 / 443 / 444; the outlet of the regeneration circulation fan 21 is provided with a regeneration system NO / NO2 measuring instrument 32, the outlet of the regeneration heater 22 is connected to a regeneration flue gas flow meter 29 and a regeneration flue gas temperature meter 28, the outlet of the semi-dry deacidification tower is provided with an inlet CEMS25, and the inlet of the chimney is provided with an outlet CEMS26.

[0057] The deacidifying agent grinding system includes a deacidifying agent coarse powder bin 8, a coarse powder bin metering feeding device 9, a grinder 10 and a grinder powder conveying fan 11 which are connected in sequence; the deacidifying agent injection system includes a deacidifying agent fine powder bin inlet isolation valve 12, a deacidifying agent fine powder bin 13, a deacidifying agent metering weighing device 14, a deacidifying agent powder conveying fan 15 and a deacidifying agent powder conveying injector 16 which are connected in sequence; the outlet of the grinder powder conveying fan 11 is connected to the deacidifying agent fine powder bin inlet isolation valve 12.

[0058] The SCR reducing agent preparation system includes an ammonia water storage tank 17, an ammonia water delivery pump 18 and an ammonia water atomizing spray gun 19 which are connected in sequence. The ammonia water in the ammonia water storage tank 17 is delivered to the inlet of the catalytic filter bag dust and nitrate integrated device 4 by the ammonia water delivery pump 18 and the ammonia water atomizing spray gun 19.

[0059] The grinder 10 is an air-classifying grinder with a remote adjustment function. The running speed of the classifying wheel built into the grinder 10 can control the particle size of the baking soda at the outlet of the grinder 10. The coarse powder bin metering feeding device 9 is a metering rotary feeding valve with a remote adjustment function. The motor speed of the rotary feeding valve is adjusted by frequency conversion to control the flow of baking soda entering the grinder 10. The deacidifying agent metering weighing device 14 adopts a loss-in-weight scale with a remote adjustment function, which can control the flow of baking soda at the outlet of the deacidifying agent powder delivery injector 16 as needed.

[0060] The semi-dry deacidification tower 2 is a slaked lime SDA semi-dry deacidification tower; the outlet flue gas temperature of the semi-dry deacidification tower 2 is 150°C, and the outlet flue gas temperature of the steam heat exchanger 3 is 180°C.

[0061] The oxidant preparation system 27 is an ozone generator. The regeneration heater 22 is an electric heater; the regeneration system dust collector 30 is a bag dust collector; and the regeneration system outlet isolation valve 31 is a gate valve.

[0062] The basic design parameters of this embodiment are shown in the following table:

[0063] Serial number project unit Numeric 1 Flue gas flow at the incinerator outlet <![CDATA[Nm 3 / h]]> 35,000.00 2 Flue gas composition at the incinerator outlet 3 <![CDATA[H2O]]> % 20.97% 4 <![CDATA[O2]]> % 7.00% 5 <![CDATA[N2]]> % 63.11% 6 <![CDATA[CO2]]> % 8.06% 7 Flue gas pollutant concentration at the incinerator outlet 8 NO <![CDATA[mg / m 3 ]]> 190.00 9 <![CDATA[NO2]]> <![CDATA[mg / m 3 ]]> 10.00 11 Steam heat exchanger outlet flue gas temperature ℃ 180.00 16 Number of chambers of catalytic filter bag dust and nitrate integrated device indivual 4 17 Number of filter elements in a single compartment indivual 252 18 Filter area of ​​a single filter element <![CDATA[m 2 ]]> 1.32

[0064] Note: The flue gas flow rate at the incinerator outlet and the flue gas pollutant concentration at the incinerator outlet in the above table are the values ​​under the standard state, dry basis and 11% O2 conversion basis.

[0065] During operation, the flue gas at the outlet of the incinerator 1 first enters the semi-dry deacidification tower 2 for primary deacidification, and then the flue gas temperature is heated to 180°C by the steam heat exchanger 3 to obtain excellent baking soda dry deacidification efficiency and catalytic filter bag SCR denitrification activity, and then the baking soda dry deacidification is used for secondary deacidification to ensure that SO in the flue gas entering the catalytic filter bag dust and nitrate integrated device 4 is x The concentration meets the use requirements of the catalytic filter bag. In this embodiment, it is required that the SO x Concentration less than 10mg / Nm 3 (Standard state, dry basis, 11% O2). In order to minimize the cost of the comprehensive deacidification agent of slaked lime SDA semi-dry deacidification and baking soda dry deacidification, the SO x The operation of the semi-dry deacidification tower 2 is automatically adjusted by the concentration, HCl concentration, and flue gas temperature to ensure that the SO X Concentration not more than 50mg / Nm 3 (Standard state, dry basis, 11% O2), HCl concentration is not more than 20mg / Nm 3 (Standard state, dry basis, 11% O2); SO measured by outlet CEMS x The concentration of baking soda and HCl concentration are automatically adjusted to control the baking soda flow rate at the outlet of baking soda powder injector 16 to ensure that the SO in the flue gas at the outlet of baking soda dry deacidification is x Concentration not more than 10mg / Nm 3 (Standard state, dry basis, 11% O2), HCl concentration is not more than 10mg / Nm 3 (Standard state, dry basis, 11% O2).

[0066] The flue gas after dry deacidification by baking soda enters the catalytic filter bag dust and nitrate integrated device 4, and performs comprehensive purification of dust removal, deacidification and denitration at the same time. The fly ash, deacidification products and deacidification agent that has not reacted in time in the flue gas are filtered and form dust filter cakes on the outer surface of the catalytic filter bag. NO in the flue gas x It enters the interior of the catalytic filter bag and reacts with the SCR reducing agent under the action of the SCR catalyst loaded inside the catalytic filter bag to convert NO x The reducing agent required by SCR is ammonia water. The SCR reducing agent preparation system includes an ammonia water storage tank 17, an ammonia water delivery pump 18 and an ammonia water atomizing spray gun 19. The ammonia water in the ammonia water storage tank 17 is delivered to the inlet of the catalytic filter bag dust and nitrate integrated device 4 by the ammonia water delivery pump 18 and the ammonia water atomizing spray gun 19; the ammonia water delivery pump 18 is frequency-controlled and can be remotely controlled. The operating frequency of the ammonia water delivery pump 18 is based on the NO measured by the outlet CEMS 26. x Concentration (standard state, dry basis, 11% O2) and NO x The difference of the control target value is automatically adjusted by PID. In this embodiment, NO x The control target value is 80mg / Nm 3 (Standard state, dry basis, 11% O2).

[0067] The flue gas at the outlet of the catalytic filter bag dust and saltpeter integrated device 4 is about 180°C, and then enters the external economizer 5, where the waste heat in the flue gas is comprehensively utilized to reduce the flue gas temperature to about 150°C, and is discharged into the chimney 7 through the induced draft fan 6.

[0068] As the running time of the catalytic filter bag dust and nitrate integrated device 4 increases, the thickness of the dust filter cake formed on the outer surface of the catalytic filter bag continues to increase, and the running resistance of each chamber 401 / 402 / 403 / 404 of the catalytic filter bag dust and nitrate integrated device 4 also continues to increase. The running resistance PV_DP of each chamber 401 / 402 / 403 / 404 is measured and calculated by the chamber inlet pressure transmitter 431 / 432 / 433 / 434 and the chamber outlet pressure transmitter 441 / 442 / / 443 / 444. When PV_DP is greater than or equal to the preset chamber cleaning starting differential pressure Crit_DP_1, it is necessary to remove the dust filter cake on the outer surface of the catalytic filter bag through chamber over-cleaning means so that the chamber running resistance PV_DP is restored to the initial running differential pressure. The initial running differential pressure refers to the chamber differential pressure or design differential pressure measured when the catalytic filter bag installed in the chamber is brand new and runs at the designed filtration wind speed.

[0069] In this embodiment, the cleaning method is pulse cleaning, the cleaning mode is online cleaning or offline cleaning, and Crit_DP_1 = 1800 Pa. When the operating resistance PV_DP of the chamber is greater than or equal to the preset chamber cleaning start differential pressure Crit_DP_1 (1800 Pa), the chamber cleaning procedure is executed. Taking chamber 401 as an example, the specific procedure is: (1) close the chamber outlet isolation valve 421; (2) clean the filter element in the chamber, and the cleaning method is pulse cleaning; (3) open the chamber outlet isolation valve 421.

[0070] Each time the chamber cleaning procedure is completed and the chamber is put into use again, it is immediately determined whether the operating resistance PV_DP after the chamber cleaning is greater than or equal to the chamber regeneration starting differential pressure Crit_DP_2, and whether ammonium bisulfate is generated in the catalytic filter bag in the chamber. The regeneration starting differential pressure Crit_DP_2 should be between the initial operating differential pressure of the chamber and the cleaning starting differential pressure Crit_DP_1. In this embodiment, Crit_DP_2=900Pa.

[0071] When the operating resistance PV_DP of the chamber after cleaning is greater than or equal to the chamber regeneration start differential pressure Crit_DP_2, the chamber regeneration start procedure is executed. Taking chamber 401 as an example, the specific procedure is as follows: (1) close the chamber inlet isolation valve 411; (2) close the chamber outlet isolation valve 421; (3) open the regeneration system inlet valve 20 to introduce part of the flue gas between the baking soda dry deacidification and the SCR reductant injection point, that is, the flue gas here has been treated with semi-dry deacidification and baking soda deacidification, and most of the SO xThe concentration has been removed, but the ammonia required for the SCR reaction has not yet been added to the flue gas, that is, the NH3 concentration in the flue gas here is extremely low to meet the needs of catalytic filter bag regeneration; at the same time, the flue gas temperature here is 180°C, which is suitable for partial oxidation of NO in the flue gas using the oxidant O3; (4) Open the chamber regeneration inlet isolation valve 23; (5) Open the chamber regeneration outlet isolation valve 24, and open the regeneration system outlet isolation valve 31; (6) Start the regeneration circulation fan 21 and set the flow rate SV_F_Reg of the regeneration circulation fan 21; (7) Start the regeneration heater 22 and set the regeneration heater 22 outlet flue gas temperature setting value SV_ Reg_Temp=250℃; (8) Start the oxidant preparation system 27, add O3 into the regeneration flue gas to oxidize part of NO into NO2. The principle of adding the oxidant is that the ratio of the molar concentration of NO to the molar concentration of NO2 in the flue gas after oxidation is R=0.5:0.5, that is, R=SV_mole_NO:SV_mole_NO2=0.5:0.5; (9) When the flue gas temperature PV_Reg_Temp at the outlet of the regeneration fan reaches SV_Reg_Temp and the regeneration fan flow PV_F_Reg reaches SV_F_Reg, start recording the chamber regeneration time T_Reg.

[0072] In this embodiment, the set value of the regeneration circulation fan flow rate SV_F_Reg (Am 3 / h) is calculated according to the following formula:

[0073] SV_F_Reg= V×A_Fil_Ele×n_Fil_Ele×60, unit is Am 3 / h;

[0074] Where, V is the regeneration gas to cloth ratio (m / min), V=0.3, A_Fil_Ele is the filtration area of ​​a single filter element, unit is m 2 , A_Fil_Ele=1.32m 2 ; n_Fil_Ele is the number of filter elements installed in a single chamber, n_Fil_Ele=252.

[0075] That is, SV_F_Reg = 0.3 × 1.32 × 252 × 60 = 5987.62Am 3 / h, by rounding, determine that SV_F_Reg=6000Am in this embodiment 3 / h.

[0076] The amount of oxidant O3 added is determined by the following method:

[0077] ,

[0078] The NO concentration PV_NO (mg / Am) in the flue gas before adding the oxidant O3 was measured by the inlet CEMS. 3 , wet basis, actual O2) and NO2 concentration PV_NO2 (mg / Am 3 , wet basis, actual O2), in this example PV_NO = 190 (mg / Am 3 , wet basis, actual O2), PV_NO2=10 (mg / Am 3 , wet basis, actual O2), SR=1, R=1.

[0079] ,

[0080] According to calculation, the addition amount of oxidant O3 in this embodiment is 0.88 kg / h.

[0081] In this embodiment, the oxidant O3 is added to oxidize part of NO into NO2, so that the molar ratio of NO to NO2 in the flue gas is 1, and then the flue gas enters the regeneration flue gas heater 22 to heat the flue gas to the set temperature, SV_Reg_Temp=250°C, and then enters the chamber 401 to regenerate the catalytic filter bag. The regenerated flue gas is introduced back to the inlet of the SDA deacidification reaction tower.

[0082] Studies have shown that in a "fast SCR" atmosphere where the molar ratio of NO to NO2 in flue gas is 1, ammonium bisulfate and NO x The decomposition reaction temperature can be reduced to below 200°C, and the slight deposit of ammonium bisulfate can be effectively decomposed at 250°C, which is much lower than the starting temperature of 390°C for the thermal decomposition of ammonium bisulfate.

[0083] Different from the traditional "standard SCR reaction" atmosphere, when the ratio of NO2 to NO in the flue gas reaches 1:1, NO x The reaction rate with NH3 is one order of magnitude higher than the conventional "standard SCR reaction", and it shows a high denitrification efficiency under high space velocity conditions and in the low temperature window range (150℃-250℃), which is called the "fast SCR" reaction. When in a "fast SCR" atmosphere, the reaction of the deposited ammonium bisulfate with NO / NO2 / O2 can be carried out at a temperature far lower than the temperature at which ammonium bisulfate thermally decomposes and releases gaseous NH3. At this time, the surface NH4 + Yes Restore NO x main substance.

[0084] The reaction equation of fast SCR is as follows:

[0085] NO + NO2 + 2NH3 → 2N2 + 3H2O

[0086] Since the regeneration flue gas entering the chamber contains almost no NH3, the above reaction is further promoted to proceed to the right, thereby completing the decomposition of ammonium bisulfate.

[0087] During the regeneration process, it is determined whether the chamber regeneration time T_Reg is greater than the chamber regeneration time setting value SV_T_Reg. In this embodiment, SV_T_Reg=12h;

[0088] When the chamber regeneration time T_Reg is greater than 12h, the chamber regeneration stop procedure is executed, and the chamber regeneration stop procedure is: (1) turn off the oxidant preparation system 27; (2) turn off the regeneration heater 22; (3) turn off the regeneration system inlet valve 20; (4) turn off the chamber regeneration outlet isolation valve 24, and turn off the regeneration system outlet isolation valve 31; (5) turn off the chamber regeneration inlet isolation valve 23; (6) open the chamber outlet isolation valve 421; (7) open the chamber inlet isolation valve 411, and the chamber 401 is put into use again.

[0089] Each time the chamber is put back into use after the chamber is regenerated, it is immediately determined whether the chamber regeneration running resistance PV_DP is greater than or equal to the chamber regeneration start differential pressure Crit_DP_2 to determine the chamber regeneration effect. If the chamber regeneration running resistance PV_DP is still greater than Crit_DP_2, an external alarm is issued to prompt the operator to handle it.

[0090] like Figure 2 As shown, the control method of the flue gas purification system of the semi-dry deacidification and catalytic filter bag dust and saltpeter integrated device is specifically that when the dry deacidification flue gas purification device is put into operation, the control is performed according to the following procedures:

[0091] S1, set the cleaning start differential pressure Crit_DP_1 of the catalytic filter bag dust and saltpeter integrated device chamber to perform the cleaning procedure to 1800Pa, set the regeneration start differential pressure Crit_DP_2 of the catalytic filter bag dust and saltpeter integrated device chamber to perform the regeneration procedure to 900Pa, set the chamber regeneration time SV_T_Reg to 24h, and execute step S2;

[0092] S2, judging whether the measured value of the operating differential pressure PV_DP of the chamber of the catalytic filter bag dust and saltpeter integrated device is greater than or equal to the set chamber cleaning start differential pressure Crit_DP_1=1800Pa, when the judgment result is "yes", executing step S3, when the judgment result is "no", executing step S11;

[0093] S3, executing the chamber cleaning procedure. Taking chamber 401 as an example, the chamber cleaning procedure is as follows: (1) closing the chamber outlet isolation valve 421; (2) cleaning the filter element in the chamber by pulse spraying; (3) opening the chamber outlet isolation valve 421; after the chamber cleaning procedure is completed, executing step S4;

[0094] S4, judging whether the measured differential pressure value PV_DP after cleaning the chamber 401 of the catalytic filter bag dust and saltpeter integrated device is greater than or equal to the set chamber regeneration start differential pressure Crit_DP_2=900Pa, when the judgment result is "yes", executing step S5, when the judgment result is "no", executing step S11;

[0095] S5. Execute the chamber regeneration startup procedure, which is as follows: (1) Close the chamber inlet isolation valve 411; (2) Close the chamber outlet isolation valve 421; (3) Open the regeneration system inlet valve 20; (4) Open the chamber regeneration inlet isolation valve 23; (5) Open the chamber regeneration outlet isolation valve 24, and open the regeneration system outlet isolation valve 31; (6) Start the regeneration circulation fan 21, and set the flow rate SV_F_Reg of the regeneration circulation fan; (7) Start the regeneration heater 22, and set the outlet flue gas temperature setting value SV_Reg_Temp of the regeneration heater 22 to 250°C; (8) Start the oxidant (O3) preparation system, and An oxidant (O3) is added to the regeneration flue gas to oxidize part of the NO into NO2. The principle of adding the oxidant is that the molar concentration ratio of NO to the molar concentration of NO2 in the flue gas after oxidation is R=0.5:0.5, that is, R=SV_mole_NO:SV_mole_NO2=0.5:0.5; (9) When the flue gas temperature PV_Reg_Temp at the outlet of the regeneration circulation fan 21 reaches SV_Reg_Temp=250°C and the regeneration fan flow PV_F_Reg reaches SV_F_Reg, the recording of the chamber regeneration time T_Reg begins; Execute step S6;

[0096] S6, judging whether the chamber regeneration time T_Reg is greater than the chamber regeneration time setting value SV_T_Reg=12h, when the judgment result is "yes", executing step S7, when the judgment result is "no", executing step S8;

[0097] S7, executing the chamber regeneration stop procedure, the chamber regeneration stop procedure is: (1) shutting down the oxidant (O3) preparation system 27; (2) shutting down the regeneration heater 22; (3) shutting down the regeneration system inlet valve 20; (4) shutting down the chamber regeneration outlet isolation valve 24, and shutting down the regeneration system outlet isolation valve 31; (5) shutting down the chamber regeneration inlet isolation valve 23; (6) opening the chamber outlet isolation valve 421; (7) opening the chamber inlet isolation valve 411, and executing step S9;

[0098] S8. Issue an external prompt to indicate that the chamber 401 is being regenerated, and execute step S6.

[0099] S9, judging whether the measured differential pressure value PV_DP after the chamber of the catalytic filter bag dust and saltpeter integrated device is greater than or equal to the set chamber regeneration start differential pressure Crit_DP_2=900Pa, when the judgment result is "yes", executing step S11, when the judgment result is "no", executing step S10;

[0100] S10, an external alarm is issued, prompting "Regeneration of chamber 401 is unsuccessful!", and the operator is requested to handle it and execute step S11;

[0101] S11. Determine whether to end the automatic control. When the judgment result is "yes", end the automatic control. When the judgment result is "no", execute step S2.

[0102] Among them, the set value of the regeneration circulation fan flow SV_F_Reg (Am 3 / h) is calculated according to the following formula:

[0103] SV_F_Reg= V×A_Fil_Ele×n_Fil_Ele×60, unit is Am 3 / h;

[0104] Where, V is the regeneration gas to cloth ratio (m / min), V=0.3, A_Fil_Ele is the filtration area of ​​a single filter element, unit is m 2 , A_Fil_Ele=1.32m 2 ; n_Fil_Ele is the number of filter elements installed in a single chamber, n_Fil_Ele=252.

[0105] That is, SV_F_Reg = 0.3 × 1.32 × 252 × 60 = 5987.62Am 3 / h, by rounding, determine that SV_F_Reg=6000Am in this embodiment 3 / h.

[0106] The amount of oxidant O3 added is determined by the following method:

[0107] ,

[0108] The NO concentration PV_NO (mg / Am) in the flue gas before adding the oxidant O3 was measured by the inlet CEMS. 3 , wet basis, actual O2) and NO2 concentration PV_NO2 (mg / Am 3 , wet basis, actual O2), in this example PV_NO = 190 (mg / Am 3, wet basis, actual O2), PV_NO2=10 (mg / Am 3 , wet basis, actual O2), SR=1, R=1.

[0109] ,

[0110] According to calculation, the addition amount of oxidant O3 in this embodiment is 0.88 kg / h.

[0111] The embodiments described above are merely descriptions of preferred implementation modes of the present invention and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should all fall within the protection scope determined by the claims of the present invention.

Claims

1. A flue gas purification system of a semi-dry deacidification and catalytic filter bag dust and saltpeter integrated device, characterized in that: It comprises an incinerator (1), a semi-dry deacidification tower (2), a steam heat exchanger (3), a catalytic filter bag dust and saltpeter integrated device (4), an external economizer (5), an induced draft fan (6), and a chimney (7) which are connected in sequence through a flue; The outlet of the steam heat exchanger (3) is connected to a deacidifying agent injection system, the deacidifying agent injection system is connected to a deacidifying agent grinding system, and the deacidifying agent is a sodium-based deacidifying agent; The inlet of the catalytic filter bag dust and saltpeter integrated device (4) is connected to the SCR reducing agent preparation system; the catalytic filter bag dust and saltpeter integrated device (4) is composed of at least two chambers, the inlet of each chamber is provided with a chamber inlet isolation valve, the outlet of each chamber is provided with a chamber outlet isolation valve, the inlet of each chamber is connected to a chamber regeneration inlet isolation valve (23), the outlet of each chamber is connected to a chamber regeneration outlet isolation valve (24), the other end of the chamber regeneration outlet isolation valve (24) is connected to the regeneration system outlet isolation valve (31), and the other end of the regeneration system outlet isolation valve (31) is connected to the inlet of the semi-dry deacidification tower (2); A regeneration system inlet valve (20) is connected to the flue connecting the outlet of the steam heat exchanger (3) and the inlet of the catalytic filter bag dust and saltpeter integrated device (4); the other end of the regeneration system inlet valve (20) is connected to the inlet of the regeneration system dust collector (30); the outlet of the regeneration system dust collector (30) is connected to the inlet of the regeneration circulation fan (21); the outlet of the regeneration circulation fan (21) is connected to the inlet of the regeneration heater (22); the outlet of the regeneration heater (22) is connected to the chamber regeneration inlet isolation valve (23); and the inlet of the regeneration circulation fan (21) is also connected to the oxidant preparation system (27); Each chamber inlet of the catalytic filter bag dust and saltpeter integrated device (4) is provided with a chamber inlet pressure transmitter, and each chamber outlet is provided with a chamber outlet pressure transmitter; the outlet of the regeneration circulation fan (21) is provided with a regeneration system NO / NO2 measuring instrument (32), the outlet of the regeneration heater (22) is connected to a regeneration flue gas flow meter (29) and a regeneration flue gas temperature meter (28), the outlet of the semi-dry deacidification tower is provided with an inlet CEMS (25), and the inlet of the chimney is provided with an outlet CEMS (26); the outlet flue gas temperature of the semi-dry deacidification tower (2) is 150°C to 160°C, and the outlet flue gas temperature of the steam heat exchanger (3) is 170°C to 190°C.

2. The flue gas purification system of the semi-dry deacidification and catalytic filter bag dust and saltpeter integrated device according to claim 1 is characterized by: The deacidifying agent grinding system comprises a deacidifying agent coarse powder bin (8), a coarse powder bin metering feeding device (9), a grinder (10) and a grinder powder feeding fan (11) which are connected in sequence; the deacidifying agent injection system comprises a deacidifying agent fine powder bin inlet cut-off valve (12), a deacidifying agent fine powder bin (13), a deacidifying agent metering weighing device (14), a deacidifying agent powder feeding fan (15) and a deacidifying agent powder feeding injector (16) which are connected in sequence; the outlet of the grinder powder feeding fan (11) is connected to the deacidifying agent fine powder bin inlet cut-off valve (12), and the deacidifying agent is baking soda.

3. The flue gas purification system of the semi-dry deacidification and catalytic filter bag dust and saltpeter integrated device according to claim 1 is characterized in that: The SCR reducing agent preparation system comprises an ammonia water storage tank (17), an ammonia water delivery pump (18) and an ammonia water atomizing spray gun (19) which are connected in sequence. The ammonia water in the ammonia water storage tank (17) is delivered to the inlet of the catalytic filter bag dust and nitrate integrated device (4) by the ammonia water delivery pump (18) and the ammonia water atomizing spray gun (19).

4. The flue gas purification system of the semi-dry deacidification and catalytic filter bag dust and saltpeter integrated device according to claim 1 is characterized in that: The semi-dry deacidification tower (2) is a slaked lime SDA semi-dry deacidification tower.

5. The flue gas purification system of the semi-dry deacidification and catalytic filter bag dust and saltpeter integrated device according to claim 1 is characterized in that: The oxidant preparation system (27) is an ozone generator, a hydrogen peroxide preparation system, a sodium hypochlorite preparation system or a sodium chlorite preparation system.

6. The flue gas purification system of the semi-dry deacidification and catalytic filter bag dust and saltpeter integrated device according to claim 1 is characterized by: The regeneration heater (22) is an electric heater; the regeneration system dust collector (30) is a bag dust collector; and the regeneration system outlet isolation valve (31) is a gate valve.

7. The control method of the flue gas purification system according to any one of claims 1 to 6, characterized in that: The following steps are involved: S1, set the cleaning start differential pressure Crit_DP_1 for the catalytic filter bag dust and saltpeter integrated device chamber to perform the cleaning procedure, set the regeneration start differential pressure Crit_DP_2 for the catalytic filter bag dust and saltpeter integrated device chamber to perform the regeneration procedure, set the chamber regeneration time SV_T_Reg, and execute step S2; the cleaning start differential pressure Crit_DP_1 = 1200 ~ 2500Pa; the regeneration start differential pressure Crit_DP_2 should be between the initial operation differential pressure of the chamber and the cleaning start differential pressure Crit_DP_1, the initial operation differential pressure refers to the chamber differential pressure or design differential pressure measured when the catalytic filter bag installed in the chamber is brand new and operates under the design filtration wind speed; the chamber regeneration time SV_T_Reg = 12 ~ 48h; S2, judging whether the measured value PV_DP of the operation differential pressure of the chamber of the catalytic filter bag dust and saltpeter integrated device is greater than or equal to the set chamber cleaning start differential pressure Crit_DP_1, when the judgment result is "yes", executing step S3, when the judgment result is "no", executing step S11; S3, execute the bin cleaning procedure, the bin cleaning procedure is: ① close the bin outlet isolation valve; ② clean the filter element in the bin, the cleaning method is line spray pulse cleaning or rotary pulse cleaning or box pulse cleaning; ③ open the bin outlet isolation valve; after the bin cleaning procedure is completed, execute step S4; S4, judging whether the measured differential pressure value PV_DP after the chamber of the catalytic filter bag dust and saltpeter integrated device is greater than or equal to the set chamber regeneration start differential pressure Crit_DP_2, when the judgment result is "yes", executing step S5, when the judgment result is "no", executing step S11; S5. Execute the chamber regeneration startup procedure, which is: ① Close the chamber inlet isolation valve; ② Close the chamber outlet isolation valve; ③ Open the regeneration system inlet valve; ④ Open the chamber regeneration inlet isolation valve; ⑤ Open the chamber regeneration outlet isolation valve, open the regeneration system outlet isolation valve; ⑥ Start the regeneration circulation fan, set the flow rate SV_F_Reg of the regeneration circulation fan; ⑦ Start the regeneration heater, set the regeneration heater outlet flue gas temperature setting value SV_Reg_Temp = 230 ~ 250 ° C; ⑧ Start the oxidant preparation system, add oxidant to the regeneration flue gas Oxidize part of NO to NO2. The principle of adding the oxidant is that the ratio R of the molar concentration of NO to the molar concentration of NO2 in the flue gas after oxidation is between 0.7:0.3 and 0.5:0.5, that is, R=SV_mole_NO:SV_mole_NO2=0.7:0.3~0.5:0.5; ⑨ When the flue gas temperature PV_Reg_Temp at the outlet of the regeneration fan reaches SV_Reg_Temp, and the regeneration fan flow PV_F_Reg reaches SV_F_Reg, start recording the chamber regeneration time T_Reg; execute step S6; S6, judging whether the chamber regeneration time T_Reg is greater than the chamber regeneration time setting value SV_T_Reg, when the judgment result is "yes", executing step S7, when the judgment result is "no", executing step S8; S7, execute the chamber regeneration stop procedure, the chamber regeneration stop procedure is: ① turn off the oxidant preparation system; ② turn off the regeneration heater; ③ turn off the regeneration system inlet valve; ④ turn off the chamber regeneration outlet isolation valve; ⑤ turn off the chamber regeneration inlet isolation valve, turn off the regeneration system outlet isolation valve; ⑥ open the chamber outlet isolation valve; ⑦ open the chamber inlet isolation valve, and execute step S9; S8, issuing an external prompt to indicate that the chamber is undergoing regeneration, and executing step S6; S9, judging whether the measured differential pressure value PV_DP after the chamber of the catalytic filter bag dust and saltpeter integrated device is greater than or equal to the set chamber regeneration start differential pressure Crit_DP_2, when the judgment result is "yes", executing step S11, when the judgment result is "no", executing step S10; S10, an external alarm is issued, prompting "chamber regeneration failed!", and the operator is requested to handle it and execute step S11; S11. Determine whether to end the automatic control. When the judgment result is "yes", end the automatic control. When the judgment result is "no", execute step S2.

8. The control method of the flue gas purification system according to claim 7, characterized in that: The set value SV_F_Reg of the regeneration circulation fan flow in step S5 is calculated according to the following formula: SV_F_Reg=V×A_Fil_Ele×n_Fil_Ele×60, unit is Am 3 / h; Wherein, V is the regeneration gas ratio, the unit is m / min, V = 0.3 ~ 1.0; A_Fil_Ele is the filtration area of ​​a single filter element, in m 2 ; n_Fil_Ele is the number of filter elements installed in a single chamber.

9. The control method of the flue gas purification system according to claim 7, characterized in that: The oxidant in step S5 is O3, and the addition amount F_O3, in kg / h, is determined by the following method: Where PV_NO is the NO concentration in the flue gas before adding the oxidant O3 measured by the inlet CEMS, in mg / Am 3 , wet basis, actual O2; PV_NO2 is the NO2 concentration in the flue gas before adding the oxidant O3 measured by the inlet CEMS, in mg / Am 3 , wet basis, actual O2; SV_F_Reg is the set value of the regeneration circulation fan flow, the unit is Am 3 / h; SR is the stoichiometric ratio of the oxidant O3, that is, the ratio of the molar amount of O3 added to the molar amount of NO to be oxidized, SR = 1 to 1.3; R is the ratio of the molar concentration of NO to the molar concentration of NO2 in the flue gas after oxidation, R = 1 to 2.

3.

10. The control method of the flue gas purification system according to claim 7, characterized in that: The amount of the oxidant added can be automatically controlled by PID through the NO concentration and NO2 concentration measured by the NO / NO2 measuring instrument of the regeneration system to ensure that the ratio of the molar concentration of NO to the molar concentration of NO2 in the flue gas is R after the oxidant is added.

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