High-salinity wastewater electrochemical recycling synergistic coal-fired flue gas sulfur oxide removal system

Abstract

The utility model discloses a high-salinity wastewater electrochemical recycling synergistic coal-fired flue gas sulfur oxide removal system which comprises a bipolar membrane electrodialysis device, an air compressor, a spray gun and an SCR (Selective Catalytic Reduction) denitration device, the first spray gun sprays alkali mist formed by mixing and atomizing the alkali liquor and compressed air prepared by the air compressor into flues at the front end and the rear end of the SCR denitration device, and the alkali mist reacts with flue gas in the flues. High-salinity wastewater of the coal-fired power plant is electrolyzed through the bipolar membrane electrodialysis device, and product alkali liquor and compressed air are mixed, atomized and sprayed into flues at the front end and the rear end of the SCR denitration device. The alkaline liquor reacts with SO2 and SO3 in the flue gas, the content of sulfur oxides in the flue gas is reduced, damage, blockage and corrosion of ammonium bisulfate to related equipment are reduced, meanwhile, the acid liquor generated through electrolysis can also be used as a softening agent of a water treatment system in a plant, and the operation cost is reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of wastewater treatment, in particular to a system for removing sulfur oxides from coal-fired flue gas in coordination with electrochemical resource utilization of high-salt wastewater. Background Art

[0002] China's coal-fired power installed capacity will be about 1.12 billion kilowatts by 2022, accounting for about 43.8% of the total installed capacity. Coal-fired units will produce a large amount of circulating water, desulfurization wastewater, acid-base regeneration wastewater, etc. during operation. These wastewaters have high salt characteristics and cannot be discharged directly.

[0003] It has become an inevitable trend that high-salinity wastewater from power plants needs to be reused according to quality and classification, and zero discharge of wastewater. At present, zero discharge of high-salinity wastewater basically adopts pretreatment + concentration reduction + terminal solidification process. The terminal solidification is mainly based on evaporation crystallization, main flue evaporation, bypass evaporation crystallization, and electrodialysis process. These processes have high investment and operating costs, and there are problems such as equipment corrosion.

[0004] Contents of the utility model

[0005] The purpose of the utility model is to provide a high-salt wastewater electrochemical resource utilization and coal-fired flue gas sulfur oxide removal system, which has low investment and operation costs and good treatment effects. While achieving zero wastewater discharge, the alkaline solution produced by bipolar membrane electrodialysis can be used to absorb sulfur oxides in the flue gas, reduce the formation of ammonium bisulfate in the subsequent flue, and reduce the risk of air preheater blockage. The investment and operation costs are low, the treatment effect is good, and it is conducive to achieving zero wastewater discharge.

[0006] In order to solve the above technical problems, an embodiment of the utility model provides a system for electrochemical resource utilization of high-salt wastewater and synergistic sulfur oxide removal from coal-fired flue gas, comprising a bipolar membrane electrodialysis device, an air compressor, a spray gun and an SCR denitrification device, wherein the bipolar membrane electrodialysis device electrolyzes the high-salt wastewater to prepare acid solution and alkali solution, and the spray gun mixes the alkali solution with the compressed air prepared by the air compressor to form an alkaline mist, which is sprayed into the front and rear end flues of the SCR denitrification device, and the alkaline mist reacts with the flue gas in the flue.

[0007] It also includes a wastewater pretreatment device connected to the bipolar membrane electrodialysis device, and the wastewater pretreatment device includes a water supply pump and a safety filter. The inlet of the water supply pump is connected to the high-salt wastewater pipeline of the coal-fired power plant for transporting the high-salt wastewater. The safety filter is connected to the water supply pump for filtering the high-salt wastewater.

[0008] Among them, it also includes an alkali liquid tank, an acid liquid tank and an atomizing water pump connected to the bipolar membrane electrodialysis device, the alkali liquid tank is used to store the alkali liquid prepared by electrolysis of the bipolar membrane electrodialysis device, the acid liquid tank is used to store the acid liquid prepared by electrolysis of the bipolar membrane electrodialysis device, and the atomizing water pump is used to pump the alkali liquid to the spray gun.

[0009] The invention also includes a frequency converter arranged on the atomizing water pump, which is used to adjust the alkali solution delivery flow of the atomizing water pump.

[0010] Wherein, the spray gun is a 2205 duplex stainless steel spray gun or a 2507 duplex stainless steel spray gun, the nozzle of the spray gun is a 2205 duplex stainless steel nozzle or a 2507 duplex stainless steel nozzle, one nozzle is arranged on the spray gun or a plurality of nozzle arrays are arranged on the spray gun.

[0011] There are multiple spray guns, which are distributed on the same side of the flue or on both sides of the flue, including a first spray gun arranged at the front flue and a second spray gun arranged at the rear flue.

[0012] Among them, it also includes a ball valve, an on-site pressure gauge, a compressed air storage tank, a first pneumatic gate valve, a check valve, a second pneumatic gate valve, and a third pneumatic gate valve which are connected in sequence through a pipeline. The ball valve is arranged on the pipeline between the air compressor and the compressed air storage tank, and is used to isolate the air compressor from the compressed air storage tank when the air compressor stops working. The on-site pressure gauge is arranged on the compressed air storage tank, and is used to display the internal pressure of the compressed air storage tank. The compressed air storage tank is connected to the spray gun through an air supply pipeline, and the first pneumatic gate valve and the check valve are arranged on the air supply pipeline in sequence to adjust the compressed air delivery amount and cut off the compressed air delivery. The compressed air storage tank and the spray gun are connected through a pipeline, and the second pneumatic gate valve is arranged on the inlet air supply pipeline of the first spray gun, and is used to adjust the compressed air delivery amount and cut off the compressed air delivery; the compressed air storage tank and the second spray gun are connected through a second pipeline, and the third pneumatic gate valve is arranged on the inlet air supply pipeline of the second spray gun, and is used to adjust the compressed air delivery amount and cut off the compressed air delivery.

[0013] It also includes a boiler and an air preheater which are connected to each other through the flue in sequence. The flue gas generated by the combustion of the boiler is passed through the SCR denitrification device to remove nitrogen oxides, and the air entering the boiler is preheated by the air preheater. The outlet flue gas of the air preheater enters the dust collector for dust removal.

[0014] Among them, it also includes a sulfide concentration detector for detecting the inlet and outlet ends of the SCR denitrification device, which is used to detect the inlet sulfide concentration and the outlet sulfide concentration of the inlet section of the SCR denitrification device, and output the inlet sulfide concentration and the outlet sulfide concentration to the power plant DSC control system, and control the alkali solution flow of the atomizing water pump through the atomizing water pump inverter.

[0015] The high-salinity wastewater electrochemical resource utilization and sulfur oxide removal system for coal-fired flue gas provided in the embodiment of the utility model has the following advantages compared with the prior art:

[0016] The high-salt wastewater electrochemical resource utilization and sulfur oxide removal system for coal-fired flue gas provided by the embodiment of the utility model electrolyzes the high-salt wastewater of the coal-fired power plant through a bipolar membrane electrodialysis device, and the product alkali solution is mixed with compressed air and atomized and sprayed in the flue before and after the SCR denitrification device. The alkali solution reacts with SO2 and SO3 in the flue gas to reduce the sulfur oxide content in the flue gas, reduce the damage, blockage and corrosion of sulfur oxides to related equipment, and the acid solution produced by electrolysis can also be used as a softening agent for the water treatment system in the plant to reduce operating costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0018] Figure 1 A schematic diagram of the structure of an embodiment of the system for electrochemical resource utilization of high-salinity wastewater and sulfur oxide removal from coal-fired flue gas provided by the utility model;

[0019] Among them, 1-bipolar membrane electrodialysis device, 11-water feed pump, 12-security filter, 2-alkali liquid tank, 21-atomizing water pump, 22-frequency converter, 3-acid liquid tank, 31-acid liquid pump, 4-air compressor, 41-ball valve, 42-on-site pressure gauge, 43-compressed air storage tank, 44-first pneumatic gate valve, 45-check valve, 46-second pneumatic gate valve, 47-third pneumatic gate valve, 5-first spray gun, 51-first nozzle, 52-first electric regulating valve, 6-second spray gun, 61-second nozzle, 62-second electric regulating valve, 7-boiler, 8-SCR denitrification device, 9-air preheater. DETAILED DESCRIPTION

[0020] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0021] Please refer to Figure 1 , Figure 1 This is a structural schematic diagram of an embodiment of the high-salt wastewater electrochemical resource utilization and coal-fired flue gas sulfur oxide removal system provided by the utility model.

[0022] In a specific embodiment, the high-salt wastewater electrochemical resource utilization and coal-fired flue gas sulfur oxide removal system includes a bipolar membrane electrodialysis device 1, an air compressor, a spray gun and an SCR denitrification device 8, wherein the bipolar membrane electrodialysis device 1 electrolyzes the high-salt wastewater to prepare acid solution and alkali solution, and the spray gun mixes the alkali solution with the compressed air prepared by the air compressor to form an alkaline mist, which is sprayed into the front and rear end flues of the SCR denitrification device 8, and the alkaline mist reacts with the flue gas in the flue.

[0023] The high-salt wastewater from the coal-fired power plant is electrolyzed by the bipolar membrane electrodialysis device 1, and the product alkali solution is mixed with compressed air and atomized and sprayed in the flue before and after the SCR denitration device 8. The alkali solution reacts with SO2 and SO3 in the flue gas to reduce the sulfur oxide content in the flue gas, reduce the damage, blockage and corrosion of sulfur oxides to related equipment, and the acid solution produced by electrolysis can also be used as a softening agent for the water treatment system in the plant to reduce operating costs.

[0024] In order to further improve the subsequent treatment efficiency, in one embodiment, the high-salt wastewater electrochemical resource utilization and coal-fired flue gas sulfur oxide removal system also includes a wastewater pretreatment device connected to the bipolar membrane electrodialysis device 1, and the wastewater pretreatment device includes a water supply pump 11 and a safety filter 12. The inlet of the water supply pump 11 is connected to the high-salt wastewater pipeline of the coal-fired power plant for transporting the high-salt wastewater, and the safety filter 12 is connected to the water supply pump 11 for filtering the high-salt wastewater.

[0025] The suspended matter in the wastewater is filtered in advance through the wastewater pretreatment device, making the subsequent atomization process reliable and improving the subsequent treatment effect.

[0026] The present application does not limit the structure of the wastewater pretreatment device, which includes but is not limited to the water supply pump 11 and the safety filter 12.

[0027] In order to further improve the atomization effect and improve the subsequent utilization efficiency of the electrolyte, in one embodiment, the high-salt wastewater electrochemical resource utilization and coal-fired flue gas sulfur oxide removal system also includes an alkali liquid tank 2, an acid liquid tank 3 and an atomizing water pump 21 connected to the bipolar membrane electrodialysis device 1, the alkali liquid tank 2 is used to store the alkali liquid prepared by electrolysis of the bipolar membrane electrodialysis device 1, the acid liquid tank 3 is used to store the acid liquid prepared by electrolysis of the bipolar membrane electrodialysis device 1, and the atomizing water pump 21 is used to pump the alkali liquid to the spray gun.

[0028] By setting up the alkali liquid tank 2, the acid liquid tank 3 and the atomizing water pump 21, the alkali liquid and the acid liquid are effectively stored. The alkali liquid is delivered to the spray gun by the atomizing water pump 21. There is no need to output all the generated alkali liquid to the spray gun in real time, and the output of the spray gun can be flexibly controlled.

[0029] In order to further achieve flexible adjustment of the output of the spray gun, in one embodiment, the high-salt wastewater electrochemical resource utilization and coal-fired flue gas sulfur oxide removal system also includes a frequency converter 22 arranged on the atomizing water pump 21, which is used to adjust the alkali solution delivery flow rate of the atomizing water pump 21.

[0030] The alkali solution delivery flow rate of the atomizing water pump 21 is adjusted by the frequency converter 22, and is adjusted in real time according to the amount of flue gas generated, thereby ensuring the high efficiency of sulfur oxide removal and avoiding excessive use.

[0031] The present application includes but is not limited to using a frequency converter 22 to adjust the alkali solution delivery flow rate of the atomizing water pump 21 .

[0032] The number and material of the spray gun and the corresponding nozzle are not limited in the present application. The spray gun is a 2205 duplex stainless steel spray gun or a 2507 duplex stainless steel spray gun, the nozzle of the spray gun is a 2205 duplex stainless steel nozzle or a 2507 duplex stainless steel nozzle, one nozzle is arranged on the spray gun or a plurality of nozzle arrays are arranged on the spray gun, or a spray gun and nozzle of other materials.

[0033] In one embodiment, there are multiple spray guns, which are distributed on the same side of the flue or on both sides of the flue, including a first spray gun disposed at the front flue and a second spray gun disposed at the rear flue.

[0034] By arranging spray guns in both the front flue and the rear flue, the overall desulfurization efficiency is ensured. The present application does not limit the number and location of the spray guns.

[0035] In order to further improve the desulfurization elimination capability, in one embodiment, the high-salt wastewater electrochemical resource utilization and coal-fired flue gas sulfur oxide removal system also includes a ball valve 41, an on-site pressure gauge 42, a compressed air storage tank 43, a first pneumatic gate valve 44, a check valve 45, a second pneumatic gate valve 46, and a third pneumatic gate valve 47, which are sequentially connected through pipelines. The ball valve 41 is arranged on the pipeline between the air compressor 4 and the compressed air storage tank 43, and is used to isolate the air compressor 4 from the compressed air storage tank 43 when the air compressor 4 stops working. The on-site pressure gauge 42 is arranged on the compressed air storage tank 43, and is used to display the internal pressure of the compressed air storage tank 43. force, the compressed air storage tank 43 is connected to the spray gun through an air supply pipeline, and the first pneumatic gate valve 44 and the check valve 45 are sequentially arranged on the air supply pipeline to adjust the compressed air delivery amount and cut off the delivery of the compressed air, the compressed air storage tank 43 is connected to the spray gun through a pipeline, and the inlet air supply pipeline of the first spray gun is provided with the second pneumatic gate valve 46 to adjust the compressed air delivery amount and cut off the compressed air delivery; the compressed air storage tank 43 and the second spray gun are connected through a second pipeline, and the inlet air supply pipeline of the second spray gun is provided with a third pneumatic gate valve 47 to adjust the compressed air delivery amount and cut off the compressed air delivery.

[0036] Through the above structure, the atomization and the input of air etc. can be efficiently adjusted, thus improving the flexibility of desulfurization.

[0037] The present application includes but is not limited to the above structures.

[0038] In order to improve the processing efficiency, in one embodiment, the high-salt wastewater electrochemical resource utilization and coal-fired flue gas sulfur oxide removal system also includes a boiler and an air preheater connected in sequence through the flue, the flue gas generated by the boiler combustion is removed of nitrogen oxides through the SCR denitrification device 8, and the air entering the boiler is preheated by the air preheater, and the outlet flue gas of the air preheater enters the dust collector for dust removal.

[0039] By setting up the air preheater, the air entering the boiler is preheated, and the outlet flue gas of the air preheater enters the dust collector for dust removal, thereby improving the operating efficiency of the boiler and reducing the generation of pollutants.

[0040] In order to further improve the feedback on desulfurization and improve the processing efficiency, in one embodiment, the high-salt wastewater electrochemical resource utilization and coal-fired flue gas sulfur oxide removal system also includes a sulfide concentration detector for detecting the inlet and outlet ends of the SCR denitrification device 8, which is used to detect the inlet sulfide concentration and the outlet sulfide concentration of the inlet section of the SCR denitrification device 8, and output the inlet sulfide concentration and the outlet sulfide concentration to the power plant DSC control system, and control the flow rate of the alkali solution of the atomizing water pump 21 through the frequency converter 22.

[0041] The inlet sulfide concentration and the outlet sulfide concentration of the inlet section of the SCR denitrification device 8 are detected in real time by means of a sulfide concentration detector, and the inlet sulfide concentration and the outlet sulfide concentration are output to the DSC control system of the power plant. The flow rate of the alkaline solution of the atomizing water pump 21 is controlled by the frequency converter 22 to improve the flexibility and reliability of the atomization output.

[0042] In one embodiment, the processing flow of the above system is as follows:

[0043] A) High-salinity wastewater from a coal-fired power plant is transported to a bipolar membrane electrodialysis device through a feed water pump for electrolysis to obtain alkali solution and acid solution, wherein the alkali solution is stored in an alkali solution tank and the acid solution is stored in an acid solution tank;

[0044] B) Storing the compressed air prepared by the air compressor in a compressed air storage tank;

[0045] C) mixing the alkali solution obtained in step A and the compressed air obtained in step B in a spray gun, adjusting the compressed air supply flow rate by a pneumatic gate valve and a check valve, adjusting the alkali solution supply flow rate by a frequency converter on an atomizing water pump, and controlling the compressed air flow rate and the alkali solution flow rate to be 140-150:1, thereby achieving alkali solution atomization;

[0046] D) the atomized alkali solution obtained in step C is evenly sprayed on the front and rear flues of the SCR denitration device through a nozzle on a spray gun to control the droplet size to 50-60 μm;

[0047] E) The acid solution prepared in step A is pumped back to the water treatment dosing system in the plant for use.

[0048] The high-salt wastewater from the coal-fired power plant is electrolyzed through a bipolar membrane electrodialysis device. The alkali solution produced by the bipolar membrane electrodialysis device and the compressed air provided by the air compressor are mixed in the spray gun to achieve atomization, and sprayed in the flue before and after the SCR denitrification device through the nozzle on the spray gun with 50-60μm droplets. In the flue before the SCR denitrification device, the main component of the alkali solution, NaOH, reacts with SO2 and SO3 in the flue gas to reduce the sulfur oxide content in the flue gas and reduce the impact of sulfur oxides on the SCR denitrification device, air preheater, and desulfurization system. In the flue after the SCR denitrification device, the main component of the alkali solution, NaOH, reacts with SO3 in the flue gas to generate Na2SO4, avoiding the blockage and corrosion of the air preheater caused by the reaction of NH3 with SO3 in the flue gas after the ammonia spraying of the SCR denitrification device. The acid HCl / H2SO4 produced by the bipolar membrane electrodialysis device can also be used as a softening agent for the water treatment system in the plant to reduce operating costs.

[0049] In one embodiment, the electrochemical resource recovery system of high-salinity wastewater is used in conjunction with the sulfur oxide removal system of coal-fired flue gas, such as Figure 1 As shown, the inlet of the water supply pump 11 is connected to the high-salt wastewater of the coal-fired power plant through a pipeline to transport the high-salt wastewater; the inlet of the security filter 12 is connected to the water supply pump 11 to filter the high-salt wastewater transported by the water supply pump; the inlet of the bipolar membrane electrodialysis device 1 is connected to the security filter 1 to electrolyze the high-salt wastewater to produce acid and alkali solution; the inlet of the alkali solution tank 2 is connected to the bipolar membrane electrodialysis device to store the alkali solution produced by the electrolysis of the bipolar membrane electrodialysis device; the atomizing water pump 21 is used to transport the alkali solution to the spray gun; the frequency converter 22 is arranged on the atomizing water pump 21 to adjust the alkali solution delivery flow rate; the inlet of the acid solution tank 3 is connected to the bipolar membrane electrodialysis device to To store the acid produced by electrolysis in the bipolar membrane electrodialysis device; an acid pump 31 is used to transport the acid to the water treatment softening and dosing system for reuse; an air compressor 4 is used to produce compressed air; a ball valve 41 is installed on the pipeline between the air compressor 4 and the compressed air storage tank; an on-site pressure gauge 42 is installed on the body of the compressed air storage tank; a compressed air storage tank 43 is used to store compressed air; a first pneumatic gate valve 44 is installed on the outlet pipeline of the compressed air storage tank; a check valve 45 is installed on the outlet pipeline of the compressed air storage tank 43; a second pneumatic gate valve 46 is installed on the air supply pipeline at the inlet of the first spray gun to control the air supply volume of the first spray gun.

[0050] The third pneumatic gate valve 47 is installed on the air supply pipeline at the inlet of the second spray gun to control the air supply volume of the second spray gun; the first spray gun 5, the first nozzle 51, the first electric valve 52, the inlet of the first spray gun is a two-way pipeline, one of which is a compressed air supply pipeline connected to the compressed air storage tank, and the compressed air supply flow is regulated by the second pneumatic gate valve, and the other is an alkali liquid delivery pipeline connected to the outlet of the atomizing water pump, and the alkali liquid delivery flow is regulated by the first electric valve, thereby realizing the atomization of the alkali liquid and compressed air in the first spray gun, and the atomized droplet particle size is controlled to 50-60μm through the first nozzle; the second spray gun 6, the second nozzle 61. The second electric valve 62. The inlet of the second spray gun 61 is two-way pipeline, one of which is a compressed air supply pipeline connected to a compressed air storage tank, and the compressed air supply flow is regulated by a No. 3 pneumatic gate valve, and the other is an alkali solution delivery pipeline connected to an outlet of an atomizing water pump, and the alkali solution delivery flow is regulated by a second electric valve, thereby realizing atomization of the alkali solution and compressed air in the second spray gun, and controlling the atomized droplet size to 50-60 μm by a second nozzle; a boiler 7, used for burning pulverized coal; an SCR denitrification device 8, used for removing nitrogen oxides (NOx) in flue gas; an air preheater 9, used for preheating the air entering the boiler.

[0051] Embodiment 1:

[0052] The desulfurization system of a 2×320MW coal-fired unit adopts a wet desulfurization process, and the desulfurization wastewater volume is about 10m 3 / h, the suspended solids of desulfurization wastewater are 6500mg / L and the hardness is 250mmol / L. After pretreatment by the triple box, the suspended solids of the produced water are 90mg / L and the hardness is 90mmol / L. The produced water of the triple box overflows into the clean water tank and is transported to the bipolar membrane electrodialysis device for electrolysis through the water feed pump. The NaOH concentration in the obtained alkali solution is about 6%, which is transported to the spray gun through the atomizing water pump and mixed with compressed air for atomization and evenly sprayed in the flue at the front and rear ends of the SCR denitrification device.

[0053] After this technical transformation, under full load conditions, the SO3 concentration in the flue after the SCR denitrification device dropped from 38mg / L to 7.5mg / L, and the SO3 removal rate was 80.26%.

[0054] In summary, the high-salt wastewater electrochemical resource utilization and sulfur oxide removal system for coal-fired flue gas provided by the embodiment of the utility model electrolyzes the high-salt wastewater of the coal-fired power plant through a bipolar membrane electrodialysis device, and the product alkali solution is mixed with compressed air and atomized and sprayed in the flue before and after the SCR denitrification device. The alkali solution reacts with SO2 and SO3 in the flue gas to reduce the sulfur oxide content in the flue gas, reduce the damage, blockage and corrosion of sulfur oxides to related equipment, and the acid solution produced by electrolysis can also be used as a softening agent for the water treatment system in the plant to reduce operating costs.

[0055] The above is a detailed introduction to the high-salt wastewater electrochemical resource utilization and coal-fired flue gas sulfur oxide removal system provided by the utility model. This article uses specific examples to illustrate the principles and implementation methods of the utility model. The description of the above embodiments is only used to help understand the method of the utility model and its core idea. It should be pointed out that for ordinary technicians in this technical field, without departing from the principles of the utility model, the utility model can also be improved and modified, and these improvements and modifications also fall within the scope of protection of the claims of the utility model.

Claims

1. A system for electrochemical resource utilization of high-salinity wastewater and sulfur oxide removal from coal-fired flue gas, characterized in that: It comprises a bipolar membrane electrodialysis device, an air compressor, a spray gun and an SCR denitration device, wherein the bipolar membrane electrodialysis device electrolyzes high-salt wastewater to prepare acid solution and alkali solution, the spray gun atomizes the alkali solution and the compressed air prepared by the air compressor to form an alkali mist which is sprayed into the front and rear end flues of the SCR denitration device, and the alkali mist reacts with the flue gas in the flue.

2. The high-salinity wastewater electrochemical resource recovery and coal-fired flue gas sulfur oxide removal system as claimed in claim 1 is characterized in that: It also includes a wastewater pretreatment device connected to the bipolar membrane electrodialysis device, the wastewater pretreatment device includes a water feed pump and a safety filter, the inlet of the water feed pump is connected to the high-salt wastewater pipeline of the coal-fired power plant, and is used to transport the high-salt wastewater, and the safety filter is connected to the water feed pump, and is used to filter the high-salt wastewater.

3. The high-salinity wastewater electrochemical resource recovery and sulfur oxide removal system for coal-fired flue gas according to claim 1 is characterized in that: It also includes an alkali liquid tank, an acid liquid tank and an atomizing water pump connected to the bipolar membrane electrodialysis device. The alkali liquid tank is used to store the alkali liquid prepared by electrolysis of the bipolar membrane electrodialysis device, the acid liquid tank is used to store the acid liquid prepared by electrolysis of the bipolar membrane electrodialysis device, and the atomizing water pump is used to pump the alkali liquid to the spray gun.

4. The high-salinity wastewater electrochemical resource recovery and sulfur oxide removal system for coal-fired flue gas as claimed in claim 3 is characterized in that: It also includes a frequency converter arranged on the atomizing water pump, which is used to adjust the alkali solution delivery flow of the atomizing water pump.

5. The high-salinity wastewater electrochemical resource recovery and sulfur oxide removal system for coal-fired flue gas according to claim 1 is characterized in that: The spray gun is a 2205 duplex stainless steel spray gun or a 2507 duplex stainless steel spray gun, the nozzle of the spray gun is a 2205 duplex stainless steel nozzle or a 2507 duplex stainless steel nozzle, one nozzle is arranged on the spray gun or a plurality of nozzle arrays are arranged on the spray gun.

6. The high-salinity wastewater electrochemical resource recovery and sulfur oxide removal system for coal-fired flue gas as claimed in claim 5 is characterized in that: There are multiple spray guns, which are distributed on the same side of the flue or on both sides of the flue, including a first spray gun arranged at the front flue and a second spray gun arranged at the rear flue.

7. The high-salinity wastewater electrochemical resource recovery and sulfur oxide removal system for coal-fired flue gas as claimed in claim 6 is characterized in that: It also includes a ball valve, an on-site pressure gauge, a compressed air storage tank, a first pneumatic gate valve, a check valve, a second pneumatic gate valve, and a third pneumatic gate valve which are sequentially connected through a pipeline. The ball valve is arranged on the pipeline between the air compressor and the compressed air storage tank, and is used to isolate the air compressor from the compressed air storage tank when the air compressor stops working. The on-site pressure gauge is arranged on the compressed air storage tank, and is used to display the internal pressure of the compressed air storage tank. The compressed air storage tank is connected to the spray gun through an air supply pipeline. The first pneumatic gate valve and the check valve are sequentially arranged on the air supply pipeline to adjust the compressed air delivery amount and cut off the delivery of the compressed air. The compressed air storage tank and the spray gun are connected through a pipeline. The second pneumatic gate valve is arranged on the inlet air supply pipeline of the first spray gun, and is used to adjust the compressed air delivery amount and cut off the compressed air delivery. The compressed air storage tank and the second spray gun are connected through a second pipeline. The third pneumatic gate valve is arranged on the inlet air supply pipeline of the second spray gun, and is used to adjust the compressed air delivery amount and cut off the compressed air delivery.

8. The high-salinity wastewater electrochemical resource recovery and sulfur oxide removal system for coal-fired flue gas according to claim 1 is characterized in that: It also includes a boiler and an air preheater which are connected to each other through the flue in sequence. The flue gas generated by the combustion of the boiler is passed through the SCR denitrification device to remove nitrogen oxides, and the air entering the boiler is preheated by the air preheater. The outlet flue gas of the air preheater enters the dust collector for dust removal.

9. The high-salinity wastewater electrochemical resource recovery and sulfur oxide removal system for coal-fired flue gas as claimed in claim 1 is characterized in that: It also includes a sulfide concentration detector for detecting the inlet and outlet ends of the SCR denitrification device, which is used to detect the inlet sulfide concentration and the outlet sulfide concentration of the inlet section of the SCR denitrification device, and output the inlet sulfide concentration and the outlet sulfide concentration to the power plant DSC control system, and control the alkali solution flow of the atomizing water pump through the atomizing water pump inverter.

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