CN112875968A

CN112875968A - Desulfurization wastewater zero discharge system and method thereof

Info

Publication number: CN112875968A
Application number: CN202110318161.5A
Authority: CN
Inventors: 闫彩霞; 李宏秀; 秦树篷; 周根来; 杨峰
Original assignee: Huadian Water Engineering Co ltd
Current assignee: Huadian Water Engineering Co ltd
Priority date: 2021-03-25
Filing date: 2021-03-25
Publication date: 2021-06-01

Abstract

The invention discloses a desulfurization wastewater zero-discharge system which comprises a pretreatment system, an evaporation reduction system and a high-temperature bypass flue drying system, wherein the pretreatment system comprises a wastewater adjusting tank, a reactor, a high-efficiency clarifier and a clean water tank which are sequentially connected through pipelines, the evaporation reduction system comprises a heat exchanger, a degassing tower, a falling film evaporator and a concentrated solution tank which are sequentially connected through pipelines, the high-temperature bypass flue drying system comprises an SCR (selective catalytic reduction) reactor, a spray drying tower and a concentrated solution tank which are sequentially connected through pipelines, and the clean water tank is connected with the heat exchanger through pipelines. The invention adopts the crystal seed method technology to preferentially grow substances such as calcium sulfate and the like precipitated in the solution concentration process on the surface of the calcium sulfate crystal seed, reduces the probability that the substances easy to scale are attached to the wall of the heat exchange tube, can effectively prevent the heat exchange tube from scaling, can recycle the calcium sulfate crystal seed, and reduces the overall cost.

Description

Desulfurization wastewater zero discharge system and method thereof

Technical Field

The invention relates to a desulfurization wastewater zero-discharge system and a method thereof, belonging to the technical field of wastewater treatment.

Background

With the gradual improvement of environmental protection standards, zero discharge of desulfurization wastewater tends to be the main trend, but the desulfurization wastewater of a thermal power plant has high content of suspended matters, high content of salt, strong corrosivity and large water quality fluctuation, and when the desulfurization wastewater is treated, the energy consumption is high, scaling is easy to occur in the evaporation process, and the maintenance cost is high. Therefore, the zero discharge cost of the desulfurization waste water is reduced, and the problem to be solved urgently in the industry is solved.

Disclosure of Invention

The invention aims to provide a desulfurization wastewater zero-discharge system and a desulfurization wastewater zero-discharge method.

In order to solve the technical problems, the invention adopts the following technical scheme: the utility model provides a desulfurization waste water zero release system, includes pretreatment systems, evaporation decrement system and high temperature bypass flue drying system, and pretreatment systems is including the waste water equalizing basin, reactor, high-efficient clarifier and the clean water basin that loop through the pipe connection, and evaporation decrement system is including the heat exchanger, degasser, falling film evaporator and the thick liquid jar that loop through the pipe connection, and high temperature bypass flue drying system is including the SCR reactor, spray drying tower and the thick liquid case that loop through the pipe connection, clean water basin and heat exchanger pipe connection are provided with concentrated system delivery pump in the pipeline section between clean water basin and the heat exchanger, thick liquid jar and thick liquid case pipe connection are provided with the thick liquid pump in the pipeline section between thick liquid jar and the thick liquid case.

The pretreatment system further comprises a pipeline A, a pipeline B, a process water system and a sludge dewatering machine, wherein the pipeline A is provided with a valve A and a valve B, the reactor is connected with a clean water tank through the pipeline A, a wastewater conveying pump is arranged on a pipeline section between a wastewater adjusting tank and the reactor, a wastewater lifting pump is arranged on a pipeline section between the reactor and the high-efficiency clarifier, a high-efficiency clarifier water outlet pipe is arranged on the high-efficiency clarifier, the high-efficiency clarifier water outlet pipe is connected on a pipeline section between the valve A and the valve B, a sludge discharge pipeline is arranged at the bottom of the high-efficiency clarifier, one end of the sludge discharge pipeline is connected with an outlet at the bottom of the high-efficiency clarifier, the other end of the sludge discharge pipeline is provided with a sludge pond, the process water system is connected with the pipeline of the reactor, the sludge dewatering machine is connected with the pipeline of the sludge pond, and a sludge conveying pump is, one end of the pipeline B is connected to a pipe section between the process water system and the reactor, the other end of the pipeline B is connected to a sludge discharge pipeline, and the bottom of the sludge dewatering machine is provided with an electric sludge hopper; and opening the valve B, enabling the discharged water to enter the pipeline A through the water outlet pipe of the high-efficiency clarifier and be conveyed to a clean water tank, enabling the discharged water of the high-efficiency clarifier to be unqualified, opening the valve A, closing the valve B, and enabling the discharged water to flow back to the reactor through the pipeline A to perform secondary reaction.

The utility model provides a zero discharge system of desulfurization waste water, be provided with waste water equalizing basin mixer in the waste water equalizing basin, be provided with the reactor mixer in the reactor, the top of reactor is provided with the medicine-adding machine, be provided with A aeration equipment in the clean water basin, be provided with B aeration equipment in the sludge impoundment, be provided with the A aeration pipe on the A aeration equipment, the one end and the A aeration equipment of A aeration pipe are connected, the other end of A aeration pipe is provided with the roots fan, be provided with the B aeration pipe on the B aeration equipment, the one end and the B aeration equipment of B aeration pipe are connected, the other end of B aeration pipe is connected in.

According to the desulfurization wastewater zero discharge system, the heat exchanger is provided with the cold water inlet pipe, the cold water outlet pipe, the hot water inlet pipe and the hot water outlet pipe, the cold water inlet pipe is connected with the side wall of the clean water tank, the cold water outlet pipe is connected with the top inlet of the degassing tower, one end of the hot water outlet pipe is connected with the heat exchanger, the other end of the hot water outlet pipe is provided with a circulating water supplementing water system, and the cold water inlet pipe is provided with the acid adding device and the scale inhibitor adding.

The utility model provides an aforementioned desulfurization waste water zero discharge system, evaporation decrement system still includes the distilled water jar, and the bottom export and the hot water inlet pipe of distilled water jar are connected, are provided with the distilled water pump on the bottom export of distilled water jar and the pipeline section between the hot water inlet pipe, and the top of distilled water jar is provided with C pipeline and D pipeline.

According to the zero discharge system of desulfurization waste water, an E pipeline and an F pipeline are arranged between the degassing tower and the falling film evaporator, one end of the C pipeline is connected with the top of the distilled water tank, the other end of the C pipeline is connected with the E pipeline, one end of the D pipeline is connected with the top of the distilled water tank, and the other end of the D pipeline is connected with the falling film evaporator.

The desulfurization wastewater zero discharge system is characterized in that a seed crystal feeding device is arranged on the falling film evaporator, a demister and a steam compressor are connected to one side of the falling film evaporator through a pipeline, the demister is connected with the steam compressor through a pipeline, an outlet portion of the steam compressor is connected with a side wall pipeline of the falling film evaporator, an evaporator circulating pipe is arranged on the falling film evaporator, one end of the evaporator circulating pipe is connected with the top of the falling film evaporator, the other end of the evaporator circulating pipe is connected with the bottom of the falling film evaporator, a circulating pump is arranged on the evaporator circulating pipe, and an alkali feeding device and a defoaming agent feeding device are arranged on a pipe section of the bottom.

In the desulfurization wastewater zero discharge system, the evaporation decrement system further comprises a seed crystal circulating pipe and a plant area steam system, an outlet of the seed crystal circulating pipe is connected to a pipe section between the defoaming agent adding device and the circulating pump, an inlet of the seed crystal circulating pipe is connected to an inlet pipeline of the circulating pump, a cyclone separator is arranged on the seed crystal circulating pipe, a G pipeline is arranged on the cyclone separator, the bottom of the cyclone separator is connected with the seed crystal circulating pipe through a G pipeline, the top of the cyclone separator is connected with the top of the concentrated solution tank through an H pipeline, one end of the I pipeline is connected to a pipe section between an outlet of the seed crystal circulating pipe and the circulating pump, the other end of the I pipeline is connected with an inlet of the cyclone separator, a cyclone separator pump is arranged on the I pipeline, and a plant area steam system pipeline is connected to a pipe section between the top of the steam compressor and the side wall of the falling film evaporator.

The high-temperature bypass flue drying system further comprises a dust remover, an air preheater and a boiler which are sequentially connected, wherein the dust remover is connected with a flue of the air preheater, a buffer tank is arranged on a pipe section between a spray drying tower and a concentrated liquid tank, a concentrated liquid lifting pump is arranged on the pipe section between the buffer tank and the concentrated liquid tank, a bottom outlet pipeline of the spray drying tower is connected with a slag bin system of a power plant, an ash conveying device is arranged on the pipe section between a bottom outlet of the spray drying tower and the slag bin system of the power plant, a flue gas pipeline A is arranged at the top of the spray drying tower, a rotary atomizer is arranged in the spray drying tower, an inlet electric plug-in door and an inlet electric adjusting door are arranged on the flue gas pipeline A, the inlet electric adjusting door is arranged at one end close to the spray drying tower, an outlet of the flue gas pipeline A is connected with an inlet of the rotary atomizer, an inlet end of the flue gas pipeline A is connected with the pipe section between the outlet of the air, a flue gas pipeline B is arranged at a bottom flue gas outlet of the spray drying tower, an outlet electric baffle door is arranged on the flue gas pipeline B, one end of the flue gas pipeline B is connected with the bottom flue gas outlet of the spray drying tower, and the other end of the flue gas pipeline B is connected with a flue between the dust remover and the air preheater.

A method for zero discharge of desulfurization wastewater comprises the following steps:

s1, opening a wastewater adjusting tank stirrer and a wastewater delivery pump, delivering the desulfurization wastewater to a reactor through a pipeline, simultaneously opening the reactor stirrer, adding an integrated adsorption flocculant into a dosing machine, stirring a mixed solution of the integrated adsorption flocculant and the desulfurization wastewater in the reactor by the reactor stirrer, opening a wastewater lifting pump, delivering the mixed solution of the integrated adsorption flocculant and the desulfurization wastewater to a high-efficiency clarifier through a pipeline, removing suspended matters in the desulfurization wastewater to enable the suspended matters to be less than or equal to 70mg/L, and obtaining effluent A and sludge;

s2, opening a valve B, enabling the A effluent to enter a pipeline A through a water outlet pipe of the efficient clarifier and be conveyed to a clean water tank, conveying sludge to a sludge tank through a sludge discharge pipeline, sequentially opening an aeration device A, an aeration device B and a Roots blower, carrying out aeration treatment on the A effluent in the clean water tank by the aeration device A, carrying out aeration treatment on the sludge in the sludge tank by the aeration device B, opening a sludge conveying pump, conveying the sludge to a sludge dewatering machine through the pipeline for dewatering treatment, and enabling the dewatered sludge to enter an electric sludge bucket;

s3, if the suspended matters are larger than 70mg/L, opening the valve A, closing the valve B, enabling the effluent A to flow back to the reactor through the pipeline A for secondary reaction, enabling the suspended matters in the mixed liquid of the integrated adsorption flocculant and the wastewater to be less than or equal to 70mg/L, then closing the valve A, opening the valve B, enabling the effluent A of the secondary reaction to be conveyed to a clean water tank through the pipeline A, and repeating the step S2;

s4, a conveying pump of a concentration system is started, pretreated A effluent is conveyed to a cold water inlet pipe, an acid adding device adds acid into the cold water inlet pipe, a scale inhibitor adding device adds a scale inhibitor into the cold water inlet pipe, the pretreated A effluent is mixed with acid and the scale inhibitor to obtain A mixed solution, the A mixed solution enters a heat exchanger through the cold water inlet pipe, the A mixed solution enters a degassing tower through a cold water outlet pipe after heat exchange treatment, degassing treatment is carried out on the A mixed solution, gases such as oxygen and dissolved carbon dioxide in waste water are removed to obtain B effluent, the B effluent enters a falling film evaporator through an F pipeline, a seed crystal is added into the falling film evaporator by a seed crystal adding device, alkali is added into the evaporator circulating pipe by an alkali adding device, a defoaming agent is added into the evaporator circulating pipe by the defoaming agent adding device, the seed crystal in the seed crystal circulating pipe also enters the evaporator circulating pipe, and a circulating pump, enabling alkali, a defoaming agent and crystal seeds to enter a falling-film evaporator to react with effluent B, performing evaporation concentration treatment to obtain effluent C, starting a cyclone separator pump, enabling the effluent C to enter a cyclone separator through a pipeline I, separating the crystal seeds from the effluent C through the cyclone separator to obtain effluent D and effluent E, enabling the effluent D to enter a concentrated solution tank through a pipeline H, enabling the effluent E to enter a crystal seed circulating pipe through a pipeline G, enabling the effluent E to enter the evaporator circulating pipe through the crystal seed circulating pipe, and enabling the effluent E to enter the falling-film evaporator under the action of the circulating pump;

s5, mixing the effluent E with the effluent B after entering the falling film evaporator to obtain a mixed solution B, and carrying out evaporation concentration treatment again to obtain steam and effluent F;

s6, enabling the steam to enter a demister through a pipeline, then entering a re-steam compressor, increasing the steam saturation pressure and temperature to obtain steam with high temperature saturation pressure, enabling the steam with the high temperature saturation pressure to return to a falling film evaporator through the pipeline for heat exchange treatment, condensing the steam into distilled water, enabling the distilled water to enter a distilled water tank through a D pipeline, turning on a distilled water pump, enabling the distilled water to enter a heat exchanger through a hot water inlet pipe, and then entering a circulating water make-up water system through a hot water outlet pipe;

s7, repeating the steps S4 and S5 for a plurality of times, and continuously evaporating the water in the mixed liquid B;

s8, opening the concentrated solution pump to make part of the water D in the concentrated solution tank enter the concentrated solution tank through the pipeline and the other part enter the seed crystal circulating pipe;

s9, opening a concentrated solution lift pump, conveying the D effluent in the concentrated solution tank to a buffer tank through a pipeline, and buffering the D effluent by the buffer tank;

s10, high-temperature flue gas is generated when a boiler operates, the high-temperature flue gas enters an SCR reactor through a pipeline for denitration treatment, an inlet electric adjusting door is opened to open an inlet electric inserting plate door, the denitrated high-temperature flue gas enters a spray drying tower through an A flue gas pipeline, then buffered D effluent enters the spray drying tower through the pipeline, the D effluent is sprayed out in a mist form through a rotary atomizer and is fully mixed with the denitrated high-temperature flue gas to obtain A flue gas and dry matters, an outlet electric baffle door is opened, the dry matters enter a dust remover through a B flue gas pipeline along with the A flue gas for dust removal treatment, and the dry matters which are not taken away by the A flue gas fall into an ash conveying device and then enter a slag bin system of a power plant through the pipeline.

Compared with the prior art, the invention has the advantages that:

1. effectively delay the scaling and reduce the cleaning frequency: aiming at the characteristics of saturated calcium sulfate and easy scaling of the desulfurization wastewater, a crystal seed method evaporation process is adopted, the generation of scaling on the surface of a heat exchange tube of an evaporator is effectively delayed while the required concentration multiple is achieved, the online rate of the system is high, and only 1-2 times of cleaning is needed in one year;

2. chemical softening is not needed, and the operation cost is saved: by adopting the seed crystal evaporation process, complex pretreatment units such as upstream chemical softening and the like are saved, the consumption of chemical agents is greatly reduced, the seed crystal can be recycled, the operation cost is saved, and compared with the membrane process, the operation cost is more advantageous;

3. lower energy consumption: the Mechanical Vapor Recompression (MVR) process is adopted, the power consumption per ton of water is lower than 20 ℃, and the operation cost is greatly reduced compared with that of the common multiple-effect evaporation process;

4. by adopting the bypass flue treatment, compared with the direct injection evaporation treatment method in the flue, the method has no potential hidden trouble and improves the dust removal efficiency of the subsequent electric dust remover;

5. the drying tower adopts a rotary atomization form, the core equipment is a rotary atomizer, the equipment has the advantages of reliability, easy maintenance, wear resistance, uniform atomization and the like, the regulation range of the spraying amount is wide, the adaptability to the change of the flue gas temperature, the flue gas components, the flue gas amount and the like is strong, and the change of the working condition of the unit can be quickly responded; the drying tower is provided with a rotary atomizer, and the flue gas enters the drying tower after passing through the flue gas distributor, so that the flue gas and the fog drops are fully mixed, and heat transfer and mass transfer reactions are realized.

Drawings

FIG. 1 is a schematic structural view of the present invention;

FIG. 2 is a schematic diagram of the pretreatment system of the present invention;

FIG. 3 is a schematic diagram of the evaporative abatement system of the present invention;

FIG. 4 is a schematic diagram of the high temperature bypass flue drying system of the present invention.

Reference numerals: 1-pretreatment system, 2-evaporation decrement system, 3-high temperature bypass flue drying system, 4-wastewater adjusting tank, 5-reactor, 6-high efficiency clarifier, 7-clean water tank, 8-heat exchanger, 9-degassing tower, 10-falling film evaporator, 11-concentrated solution tank, 12-SCR reactor, 13-spray drying tower, 14-concentrated solution tank, 15-concentration system delivery pump, 16-concentrated solution pump, 17-A pipeline, 18-B pipeline, 19-process water system, 20-sludge dewatering machine, 21-A valve, 22-B valve, 23-wastewater delivery pump, 24-wastewater lift pump, 25-high efficiency clarifier water outlet pipe, 26-sludge discharge pipeline, 27-sludge tank, 28-sludge delivery pump, 29-an electric mud bucket, 30-a wastewater adjusting tank stirrer, 31-a reactor stirrer, 32-a dosing machine, 33-a aeration device, 34-B aeration device, 35-a aeration pipe, 36-roots blower, 37-B aeration pipe, 38-cold water inlet pipe, 39-cold water outlet pipe, 40-hot water inlet pipe, 41-hot water outlet pipe, 42-circulating water replenishing system, 43-acid dosing device, 44-scale inhibitor dosing device, 45-distilled water tank, 46-distilled water pump, 47-C pipeline, 48-D pipeline, 49-E pipeline, 50-F pipeline, 51-seed crystal dosing device, 52-demister, 53-steam compressor, 54-evaporator circulating pipe and 55-circulating pump, 56-alkali adding device, 57-defoaming agent adding device, 58-seed crystal circulating pipe, 59-cyclone separator, 60-G pipeline, 61-H pipeline, 62-I pipeline, 63-cyclone separator pump, 64-dust remover, 65-air preheater, 66-boiler, 67-buffer tank, 68-concentrated liquid lifting pump, 69-power plant slag bin system, 70-ash conveying device, 71-A flue gas pipeline, 72-rotary atomizer, 73-inlet electric plugboard door, 74-inlet electric adjusting door, 75-B flue gas pipeline and 76-outlet electric baffle door; 77-plant steam System.

The invention is further described with reference to the following figures and detailed description.

Detailed Description

Example 1 of the invention: the utility model provides a desulfurization waste water zero discharge system, includes pretreatment systems 1, evaporation decrement system 2 and high temperature bypass flue drying system 3, pretreatment systems 1 is including the waste water equalizing basin 4 that loops through the pipe connection, reactor 5, high-efficient clarifier 6 and clean water basin 7, and evaporation decrement system 2 is including the heat exchanger 8 that loops through the pipe connection, degasser 9, falling film evaporator 10 and dense solution jar 11, and high temperature bypass flue drying system 3 is including the SCR reactor 12 that loops through the pipe connection, spray drying tower 13 and dense solution case 14,

clean water basin

7 and 8 pipe connection of heat exchanger, be provided with concentrated system delivery pump 15 on the pipeline section between clean water basin 7 and the heat exchanger 8, dense solution jar 11 and dense solution case 14 pipe connection, be provided with dense solution pump 16 on the pipeline section between dense solution jar 11 and the dense solution case 14.

Example 2 of the invention: a desulfurization wastewater zero discharge system comprises a pretreatment system 1, an evaporation decrement system 2 and a high-temperature bypass flue drying system 3, wherein the pretreatment system 1 comprises a wastewater adjusting tank 4, a reactor 5, a high-efficiency clarifier 6 and a clean water tank 7 which are sequentially connected through a pipeline, the evaporation decrement system 2 comprises a heat exchanger 8, a degassing tower 9, a falling film evaporator 10 and a concentrated solution tank 11 which are sequentially connected through a pipeline, the high-temperature bypass flue drying system 3 comprises an SCR (selective catalytic reduction) reactor 12, a spray drying tower 13 and a concentrated solution tank 14 which are sequentially connected through a pipeline, the clean water tank 7 is connected with the heat exchanger 8 through a pipeline, a concentrated system conveying pump 15 is arranged on a pipe section between the clean water tank 7 and the heat exchanger 8, the concentrated solution tank 11 is connected with the concentrated solution tank 14 through a pipeline, and a concentrated solution pump 16 is arranged on a pipe section between the concentrated solution; the pretreatment system 1 also comprises an A pipeline 17, a B pipeline 18, a process water system 19 and a sludge dewatering machine 20, wherein the A pipeline 17 is provided with an A valve 21 and a B valve 22, the reactor 5 is connected with the clean water tank 7 through the A pipeline 17, a pipe section between the wastewater adjusting tank 4 and the reactor 5 is provided with a wastewater delivery pump 23, a pipe section between the reactor 5 and the high-efficiency clarifier 6 is provided with a wastewater lift pump 24, the high-efficiency clarifier 6 is provided with a high-efficiency clarifier water outlet pipe 25, the high-efficiency clarifier water outlet pipe 25 is connected with the pipe section between the A valve 21 and the B valve 22, the bottom of the high-efficiency clarifier 6 is provided with a sludge discharge pipeline 26, one end of the sludge discharge pipeline 26 is connected with an outlet at the bottom of the high-efficiency clarifier 6, the other end of the sludge discharge pipeline 26 is provided with a sludge tank 27, the process water system 19 is connected with the reactor 5, a sludge delivery pump 28 is arranged on a pipe section between the sludge dewatering machine 20 and the sludge pool 27, one end of the B pipeline 18 is connected on the pipe section between the process water system 19 and the reactor 5, the other end of the B pipeline 18 is connected with a sludge discharge pipeline 26, and the bottom of the sludge dewatering machine 20 is provided with an electric sludge hopper 29; and (3) opening a valve B22 when the effluent of the high-efficiency clarifier 6 is qualified, enabling the effluent to enter the pipeline A17 through an outlet pipe 25 of the high-efficiency clarifier and be conveyed to the clean water tank 7, enabling the effluent of the high-efficiency clarifier 6 to be unqualified, opening the valve A21, closing the valve B22, and enabling the effluent to flow back to the reactor 5 through the pipeline A17 for secondary reaction.

Example 3 of the invention: a desulfurization wastewater zero discharge system comprises a pretreatment system 1, an evaporation decrement system 2 and a high-temperature bypass flue drying system 3, wherein the pretreatment system 1 comprises a wastewater adjusting tank 4, a reactor 5, a high-efficiency clarifier 6 and a clean water tank 7 which are sequentially connected through a pipeline, the evaporation decrement system 2 comprises a heat exchanger 8, a degassing tower 9, a falling film evaporator 10 and a concentrated solution tank 11 which are sequentially connected through a pipeline, the high-temperature bypass flue drying system 3 comprises an SCR (selective catalytic reduction) reactor 12, a spray drying tower 13 and a concentrated solution tank 14 which are sequentially connected through a pipeline, the clean water tank 7 is connected with the heat exchanger 8 through a pipeline, a concentrated system conveying pump 15 is arranged on a pipe section between the clean water tank 7 and the heat exchanger 8, the concentrated solution tank 11 is connected with the concentrated solution tank 14 through a pipeline, and a concentrated solution pump 16 is arranged on a pipe section between the concentrated solution; the pretreatment system 1 also comprises an A pipeline 17, a B pipeline 18, a process water system 19 and a sludge dewatering machine 20, wherein the A pipeline 17 is provided with an A valve 21 and a B valve 22, the reactor 5 is connected with the clean water tank 7 through the A pipeline 17, a pipe section between the wastewater adjusting tank 4 and the reactor 5 is provided with a wastewater delivery pump 23, a pipe section between the reactor 5 and the high-efficiency clarifier 6 is provided with a wastewater lift pump 24, the high-efficiency clarifier 6 is provided with a high-efficiency clarifier water outlet pipe 25, the high-efficiency clarifier water outlet pipe 25 is connected with the pipe section between the A valve 21 and the B valve 22, the bottom of the high-efficiency clarifier 6 is provided with a sludge discharge pipeline 26, one end of the sludge discharge pipeline 26 is connected with an outlet at the bottom of the high-efficiency clarifier 6, the other end of the sludge discharge pipeline 26 is provided with a sludge tank 27, the process water system 19 is connected with the reactor 5, a sludge delivery pump 28 is arranged on a pipe section between the sludge dewatering machine 20 and the sludge pool 27, one end of the B pipeline 18 is connected on the pipe section between the process water system 19 and the reactor 5, the other end of the B pipeline 18 is connected with a sludge discharge pipeline 26, and the bottom of the sludge dewatering machine 20 is provided with an electric sludge hopper 29; the effluent of the high-efficiency clarifier 6 is qualified, the valve B22 is opened, the effluent enters the pipeline A17 through the water outlet pipe 25 of the high-efficiency clarifier and is conveyed to the clean water tank 7, the effluent of the high-efficiency clarifier 6 is unqualified, the valve A21 is opened, the valve B22 is closed, and the effluent is enabled to flow back to the reactor 5 through the pipeline A17 for secondary reaction; be provided with waste water equalizing basin mixer 30 in the waste water equalizing basin 4, be provided with reactor mixer 31 in the reactor 5, the top of reactor 5 is provided with medicine feed machine 32, be provided with A aeration equipment 33 in the clean water basin 7, be provided with B aeration equipment 34 in the sludge impoundment 27, be provided with A aeration pipe 35 on the A aeration equipment 33, the one end and the A aeration equipment 33 of A aeration pipe 35 are connected, the other end of A aeration pipe 35 is provided with roots's fan 36, be provided with B aeration pipe 37 on the B aeration equipment 34, the one end and the B aeration equipment 34 of B aeration pipe 37 are connected, the other end of B aeration pipe 37 is connected in roots's fan 36.

Example 4 of the invention: a desulfurization wastewater zero discharge system comprises a pretreatment system 1, an evaporation decrement system 2 and a high-temperature bypass flue drying system 3, wherein the pretreatment system 1 comprises a wastewater adjusting tank 4, a reactor 5, a high-efficiency clarifier 6 and a clean water tank 7 which are sequentially connected through a pipeline, the evaporation decrement system 2 comprises a heat exchanger 8, a degassing tower 9, a falling film evaporator 10 and a concentrated solution tank 11 which are sequentially connected through a pipeline, the high-temperature bypass flue drying system 3 comprises an SCR (selective catalytic reduction) reactor 12, a spray drying tower 13 and a concentrated solution tank 14 which are sequentially connected through a pipeline, the clean water tank 7 is connected with the heat exchanger 8 through a pipeline, a concentrated system conveying pump 15 is arranged on a pipe section between the clean water tank 7 and the heat exchanger 8, the concentrated solution tank 11 is connected with the concentrated solution tank 14 through a pipeline, and a concentrated solution pump 16 is arranged on a pipe section between the concentrated solution; the pretreatment system 1 also comprises an A pipeline 17, a B pipeline 18, a process water system 19 and a sludge dewatering machine 20, wherein the A pipeline 17 is provided with an A valve 21 and a B valve 22, the reactor 5 is connected with the clean water tank 7 through the A pipeline 17, a pipe section between the wastewater adjusting tank 4 and the reactor 5 is provided with a wastewater delivery pump 23, a pipe section between the reactor 5 and the high-efficiency clarifier 6 is provided with a wastewater lift pump 24, the high-efficiency clarifier 6 is provided with a high-efficiency clarifier water outlet pipe 25, the high-efficiency clarifier water outlet pipe 25 is connected with the pipe section between the A valve 21 and the B valve 22, the bottom of the high-efficiency clarifier 6 is provided with a sludge discharge pipeline 26, one end of the sludge discharge pipeline 26 is connected with an outlet at the bottom of the high-efficiency clarifier 6, the other end of the sludge discharge pipeline 26 is provided with a sludge tank 27, the process water system 19 is connected with the reactor 5, a sludge delivery pump 28 is arranged on a pipe section between the sludge dewatering machine 20 and the sludge pool 27, one end of the B pipeline 18 is connected on the pipe section between the process water system 19 and the reactor 5, the other end of the B pipeline 18 is connected with a sludge discharge pipeline 26, and the bottom of the sludge dewatering machine 20 is provided with an electric sludge hopper 29; the effluent of the high-efficiency clarifier 6 is qualified, the valve B22 is opened, the effluent enters the pipeline A17 through the water outlet pipe 25 of the high-efficiency clarifier and is conveyed to the clean water tank 7, the effluent of the high-efficiency clarifier 6 is unqualified, the valve A21 is opened, the valve B22 is closed, and the effluent is enabled to flow back to the reactor 5 through the pipeline A17 for secondary reaction; a wastewater adjusting tank stirrer 30 is arranged in the wastewater adjusting tank 4, a reactor stirrer 31 is arranged in the reactor 5, a chemical feeding machine 32 is arranged at the top of the reactor 5, an A aeration device 33 is arranged in the clean water tank 7, a B aeration device 34 is arranged in the sludge tank 27, an A aeration pipe 35 is arranged on the A aeration device 33, one end of the A aeration pipe 35 is connected with the A aeration device 33, the other end of the A aeration pipe 35 is provided with a Roots blower 36, a B aeration pipe 37 is arranged on the B aeration device 34, one end of the B aeration pipe 37 is connected with the B aeration device 34, and the other end of the B aeration pipe 37 is connected with the Roots blower 36; the heat exchanger 8 is provided with a cold water inlet pipe 38, a cold water outlet pipe 39, a hot water inlet pipe 40 and a hot water outlet pipe 41, the cold water inlet pipe 38 is connected with the side wall of the clean water tank 7, the cold water outlet pipe 39 is connected with the top inlet of the degassing tower 9, one end of the hot water outlet pipe 41 is connected with the heat exchanger 8, the other end of the hot water outlet pipe 41 is provided with a circulating water supplementing water system 42, and the cold water inlet pipe 38 is provided with an acid adding device 43 and a scale inhibitor adding device 44.

Example 5 of the invention: a desulfurization wastewater zero discharge system comprises a pretreatment system 1, an evaporation decrement system 2 and a high-temperature bypass flue drying system 3, wherein the pretreatment system 1 comprises a wastewater adjusting tank 4, a reactor 5, a high-efficiency clarifier 6 and a clean water tank 7 which are sequentially connected through a pipeline, the evaporation decrement system 2 comprises a heat exchanger 8, a degassing tower 9, a falling film evaporator 10 and a concentrated solution tank 11 which are sequentially connected through a pipeline, the high-temperature bypass flue drying system 3 comprises an SCR (selective catalytic reduction) reactor 12, a spray drying tower 13 and a concentrated solution tank 14 which are sequentially connected through a pipeline, the clean water tank 7 is connected with the heat exchanger 8 through a pipeline, a concentrated system conveying pump 15 is arranged on a pipe section between the clean water tank 7 and the heat exchanger 8, the concentrated solution tank 11 is connected with the concentrated solution tank 14 through a pipeline, and a concentrated solution pump 16 is arranged on a pipe section between the concentrated solution; the pretreatment system 1 also comprises an A pipeline 17, a B pipeline 18, a process water system 19 and a sludge dewatering machine 20, wherein the A pipeline 17 is provided with an A valve 21 and a B valve 22, the reactor 5 is connected with the clean water tank 7 through the A pipeline 17, a pipe section between the wastewater adjusting tank 4 and the reactor 5 is provided with a wastewater delivery pump 23, a pipe section between the reactor 5 and the high-efficiency clarifier 6 is provided with a wastewater lift pump 24, the high-efficiency clarifier 6 is provided with a high-efficiency clarifier water outlet pipe 25, the high-efficiency clarifier water outlet pipe 25 is connected with the pipe section between the A valve 21 and the B valve 22, the bottom of the high-efficiency clarifier 6 is provided with a sludge discharge pipeline 26, one end of the sludge discharge pipeline 26 is connected with an outlet at the bottom of the high-efficiency clarifier 6, the other end of the sludge discharge pipeline 26 is provided with a sludge tank 27, the process water system 19 is connected with the reactor 5, a sludge delivery pump 28 is arranged on a pipe section between the sludge dewatering machine 20 and the sludge pool 27, one end of the B pipeline 18 is connected on the pipe section between the process water system 19 and the reactor 5, the other end of the B pipeline 18 is connected with a sludge discharge pipeline 26, and the bottom of the sludge dewatering machine 20 is provided with an electric sludge hopper 29; the effluent of the high-efficiency clarifier 6 is qualified, the valve B22 is opened, the effluent enters the pipeline A17 through the water outlet pipe 25 of the high-efficiency clarifier and is conveyed to the clean water tank 7, the effluent of the high-efficiency clarifier 6 is unqualified, the valve A21 is opened, the valve B22 is closed, and the effluent is enabled to flow back to the reactor 5 through the pipeline A17 for secondary reaction; a wastewater adjusting tank stirrer 30 is arranged in the wastewater adjusting tank 4, a reactor stirrer 31 is arranged in the reactor 5, a chemical feeding machine 32 is arranged at the top of the reactor 5, an A aeration device 33 is arranged in the clean water tank 7, a B aeration device 34 is arranged in the sludge tank 27, an A aeration pipe 35 is arranged on the A aeration device 33, one end of the A aeration pipe 35 is connected with the A aeration device 33, the other end of the A aeration pipe 35 is provided with a Roots blower 36, a B aeration pipe 37 is arranged on the B aeration device 34, one end of the B aeration pipe 37 is connected with the B aeration device 34, and the other end of the B aeration pipe 37 is connected with the Roots blower 36; the heat exchanger 8 is provided with a cold water inlet pipe 38, a cold water outlet pipe 39, a hot water inlet pipe 40 and a hot water outlet pipe 41, the cold water inlet pipe 38 is connected with the side wall of the clean water tank 7, the cold water outlet pipe 39 is connected with the top inlet of the degassing tower 9, one end of the hot water outlet pipe 41 is connected with the heat exchanger 8, the other end of the hot water outlet pipe 41 is provided with a circulating water supplementing system 42, and the cold water inlet pipe 38 is provided with an acid adding device 43 and a scale inhibitor adding device 44; the evaporation decrement system 2 further comprises a distilled water tank 45, the bottom outlet of the distilled water tank 45 is connected with the hot water inlet pipe 40, a distilled water pump 46 is arranged on a pipe section between the bottom outlet of the distilled water tank 45 and the hot water inlet pipe 40, and a C pipeline 47 and a D pipeline 48 are arranged at the top of the distilled water tank 45.

Example 6 of the invention: a desulfurization wastewater zero discharge system comprises a pretreatment system 1, an evaporation decrement system 2 and a high-temperature bypass flue drying system 3, wherein the pretreatment system 1 comprises a wastewater adjusting tank 4, a reactor 5, a high-efficiency clarifier 6 and a clean water tank 7 which are sequentially connected through a pipeline, the evaporation decrement system 2 comprises a heat exchanger 8, a degassing tower 9, a falling film evaporator 10 and a concentrated solution tank 11 which are sequentially connected through a pipeline, the high-temperature bypass flue drying system 3 comprises an SCR (selective catalytic reduction) reactor 12, a spray drying tower 13 and a concentrated solution tank 14 which are sequentially connected through a pipeline, the clean water tank 7 is connected with the heat exchanger 8 through a pipeline, a concentrated system conveying pump 15 is arranged on a pipe section between the clean water tank 7 and the heat exchanger 8, the concentrated solution tank 11 is connected with the concentrated solution tank 14 through a pipeline, and a concentrated solution pump 16 is arranged on a pipe section between the concentrated solution; the pretreatment system 1 also comprises an A pipeline 17, a B pipeline 18, a process water system 19 and a sludge dewatering machine 20, wherein the A pipeline 17 is provided with an A valve 21 and a B valve 22, the reactor 5 is connected with the clean water tank 7 through the A pipeline 17, a pipe section between the wastewater adjusting tank 4 and the reactor 5 is provided with a wastewater delivery pump 23, a pipe section between the reactor 5 and the high-efficiency clarifier 6 is provided with a wastewater lift pump 24, the high-efficiency clarifier 6 is provided with a high-efficiency clarifier water outlet pipe 25, the high-efficiency clarifier water outlet pipe 25 is connected with the pipe section between the A valve 21 and the B valve 22, the bottom of the high-efficiency clarifier 6 is provided with a sludge discharge pipeline 26, one end of the sludge discharge pipeline 26 is connected with an outlet at the bottom of the high-efficiency clarifier 6, the other end of the sludge discharge pipeline 26 is provided with a sludge tank 27, the process water system 19 is connected with the reactor 5, a sludge delivery pump 28 is arranged on a pipe section between the sludge dewatering machine 20 and the sludge pool 27, one end of the B pipeline 18 is connected on the pipe section between the process water system 19 and the reactor 5, the other end of the B pipeline 18 is connected with a sludge discharge pipeline 26, and the bottom of the sludge dewatering machine 20 is provided with an electric sludge hopper 29; the effluent of the high-efficiency clarifier 6 is qualified, the valve B22 is opened, the effluent enters the pipeline A17 through the water outlet pipe 25 of the high-efficiency clarifier and is conveyed to the clean water tank 7, the effluent of the high-efficiency clarifier 6 is unqualified, the valve A21 is opened, the valve B22 is closed, and the effluent is enabled to flow back to the reactor 5 through the pipeline A17 for secondary reaction; a wastewater adjusting tank stirrer 30 is arranged in the wastewater adjusting tank 4, a reactor stirrer 31 is arranged in the reactor 5, a chemical feeding machine 32 is arranged at the top of the reactor 5, an A aeration device 33 is arranged in the clean water tank 7, a B aeration device 34 is arranged in the sludge tank 27, an A aeration pipe 35 is arranged on the A aeration device 33, one end of the A aeration pipe 35 is connected with the A aeration device 33, the other end of the A aeration pipe 35 is provided with a Roots blower 36, a B aeration pipe 37 is arranged on the B aeration device 34, one end of the B aeration pipe 37 is connected with the B aeration device 34, and the other end of the B aeration pipe 37 is connected with the Roots blower 36; the heat exchanger 8 is provided with a cold water inlet pipe 38, a cold water outlet pipe 39, a hot water inlet pipe 40 and a hot water outlet pipe 41, the cold water inlet pipe 38 is connected with the side wall of the clean water tank 7, the cold water outlet pipe 39 is connected with the top inlet of the degassing tower 9, one end of the hot water outlet pipe 41 is connected with the heat exchanger 8, the other end of the hot water outlet pipe 41 is provided with a circulating water supplementing system 42, and the cold water inlet pipe 38 is provided with an acid adding device 43 and a scale inhibitor adding device 44; the evaporation decrement system 2 further comprises a distilled water tank 45, the bottom outlet of the distilled water tank 45 is connected with the hot water inlet pipe 40, a distilled water pump 46 is arranged on a pipe section between the bottom outlet of the distilled water tank 45 and the hot water inlet pipe 40, and a C pipeline 47 and a D pipeline 48 are arranged at the top of the distilled water tank 45; an E pipeline 49 and an F pipeline 50 are arranged between the degassing tower 9 and the falling-film evaporator 10, one end of a C pipeline 47 is connected with the top of the distilled water tank 45, the other end of the C pipeline 47 is connected with the E pipeline 49, one end of a D pipeline 48 is connected with the top of the distilled water tank 45, and the other end of the D pipeline 48 is connected with the falling-film evaporator 10.

Example 7 of the invention: a desulfurization wastewater zero discharge system comprises a pretreatment system 1, an evaporation decrement system 2 and a high-temperature bypass flue drying system 3, wherein the pretreatment system 1 comprises a wastewater adjusting tank 4, a reactor 5, a high-efficiency clarifier 6 and a clean water tank 7 which are sequentially connected through a pipeline, the evaporation decrement system 2 comprises a heat exchanger 8, a degassing tower 9, a falling film evaporator 10 and a concentrated solution tank 11 which are sequentially connected through a pipeline, the high-temperature bypass flue drying system 3 comprises an SCR (selective catalytic reduction) reactor 12, a spray drying tower 13 and a concentrated solution tank 14 which are sequentially connected through a pipeline, the clean water tank 7 is connected with the heat exchanger 8 through a pipeline, a concentrated system conveying pump 15 is arranged on a pipe section between the clean water tank 7 and the heat exchanger 8, the concentrated solution tank 11 is connected with the concentrated solution tank 14 through a pipeline, and a concentrated solution pump 16 is arranged on a pipe section between the concentrated solution; the pretreatment system 1 also comprises an A pipeline 17, a B pipeline 18, a process water system 19 and a sludge dewatering machine 20, wherein the A pipeline 17 is provided with an A valve 21 and a B valve 22, the reactor 5 is connected with the clean water tank 7 through the A pipeline 17, a pipe section between the wastewater adjusting tank 4 and the reactor 5 is provided with a wastewater delivery pump 23, a pipe section between the reactor 5 and the high-efficiency clarifier 6 is provided with a wastewater lift pump 24, the high-efficiency clarifier 6 is provided with a high-efficiency clarifier water outlet pipe 25, the high-efficiency clarifier water outlet pipe 25 is connected with the pipe section between the A valve 21 and the B valve 22, the bottom of the high-efficiency clarifier 6 is provided with a sludge discharge pipeline 26, one end of the sludge discharge pipeline 26 is connected with an outlet at the bottom of the high-efficiency clarifier 6, the other end of the sludge discharge pipeline 26 is provided with a sludge tank 27, the process water system 19 is connected with the reactor 5, a sludge delivery pump 28 is arranged on a pipe section between the sludge dewatering machine 20 and the sludge pool 27, one end of the B pipeline 18 is connected on the pipe section between the process water system 19 and the reactor 5, the other end of the B pipeline 18 is connected with a sludge discharge pipeline 26, and the bottom of the sludge dewatering machine 20 is provided with an electric sludge hopper 29; the effluent of the high-efficiency clarifier 6 is qualified, the valve B22 is opened, the effluent enters the pipeline A17 through the water outlet pipe 25 of the high-efficiency clarifier and is conveyed to the clean water tank 7, the effluent of the high-efficiency clarifier 6 is unqualified, the valve A21 is opened, the valve B22 is closed, and the effluent is enabled to flow back to the reactor 5 through the pipeline A17 for secondary reaction; a wastewater adjusting tank stirrer 30 is arranged in the wastewater adjusting tank 4, a reactor stirrer 31 is arranged in the reactor 5, a chemical feeding machine 32 is arranged at the top of the reactor 5, an A aeration device 33 is arranged in the clean water tank 7, a B aeration device 34 is arranged in the sludge tank 27, an A aeration pipe 35 is arranged on the A aeration device 33, one end of the A aeration pipe 35 is connected with the A aeration device 33, the other end of the A aeration pipe 35 is provided with a Roots blower 36, a B aeration pipe 37 is arranged on the B aeration device 34, one end of the B aeration pipe 37 is connected with the B aeration device 34, and the other end of the B aeration pipe 37 is connected with the Roots blower 36; the heat exchanger 8 is provided with a cold water inlet pipe 38, a cold water outlet pipe 39, a hot water inlet pipe 40 and a hot water outlet pipe 41, the cold water inlet pipe 38 is connected with the side wall of the clean water tank 7, the cold water outlet pipe 39 is connected with the top inlet of the degassing tower 9, one end of the hot water outlet pipe 41 is connected with the heat exchanger 8, the other end of the hot water outlet pipe 41 is provided with a circulating water supplementing system 42, and the cold water inlet pipe 38 is provided with an acid adding device 43 and a scale inhibitor adding device 44; the evaporation decrement system 2 further comprises a distilled water tank 45, the bottom outlet of the distilled water tank 45 is connected with the hot water inlet pipe 40, a distilled water pump 46 is arranged on a pipe section between the bottom outlet of the distilled water tank 45 and the hot water inlet pipe 40, and a C pipeline 47 and a D pipeline 48 are arranged at the top of the distilled water tank 45; an E pipeline 49 and an F pipeline 50 are arranged between the degassing tower 9 and the falling-film evaporator 10, one end of a C pipeline 47 is connected with the top of the distilled water tank 45, the other end of the C pipeline 47 is connected with the E pipeline 49, one end of a D pipeline 48 is connected with the top of the distilled water tank 45, and the other end of the D pipeline 48 is connected with the falling-film evaporator 10; the falling-film evaporator 10 is provided with a seed crystal feeding device 51, one side of the falling-film evaporator 10 is connected with a demister 52 and a vapor compressor 53 through pipelines, the demister 52 is connected with the vapor compressor 53 through a pipeline, an outlet part of the vapor compressor 53 is connected with a side wall pipeline of the falling-film evaporator 10, the falling-film evaporator 10 is provided with an evaporator circulating pipe 54, one end of the evaporator circulating pipe 54 is connected with the top of the falling-film evaporator 10, the other end of the evaporator circulating pipe 54 is connected with the bottom of the falling-film evaporator 10, the evaporator circulating pipe 54 is provided with a circulating pump 55, and an alkali feeding device 56 and a defoaming agent feeding device 57 are arranged on a pipe section of the.

Example 8 of the invention: a desulfurization wastewater zero discharge system comprises a pretreatment system 1, an evaporation decrement system 2 and a high-temperature bypass flue drying system 3, wherein the pretreatment system 1 comprises a wastewater adjusting tank 4, a reactor 5, a high-efficiency clarifier 6 and a clean water tank 7 which are sequentially connected through a pipeline, the evaporation decrement system 2 comprises a heat exchanger 8, a degassing tower 9, a falling film evaporator 10 and a concentrated solution tank 11 which are sequentially connected through a pipeline, the high-temperature bypass flue drying system 3 comprises an SCR (selective catalytic reduction) reactor 12, a spray drying tower 13 and a concentrated solution tank 14 which are sequentially connected through a pipeline, the clean water tank 7 is connected with the heat exchanger 8 through a pipeline, a concentrated system conveying pump 15 is arranged on a pipe section between the clean water tank 7 and the heat exchanger 8, the concentrated solution tank 11 is connected with the concentrated solution tank 14 through a pipeline, and a concentrated solution pump 16 is arranged on a pipe section between the concentrated solution; the pretreatment system 1 also comprises an A pipeline 17, a B pipeline 18, a process water system 19 and a sludge dewatering machine 20, wherein the A pipeline 17 is provided with an A valve 21 and a B valve 22, the reactor 5 is connected with the clean water tank 7 through the A pipeline 17, a pipe section between the wastewater adjusting tank 4 and the reactor 5 is provided with a wastewater delivery pump 23, a pipe section between the reactor 5 and the high-efficiency clarifier 6 is provided with a wastewater lift pump 24, the high-efficiency clarifier 6 is provided with a high-efficiency clarifier water outlet pipe 25, the high-efficiency clarifier water outlet pipe 25 is connected with the pipe section between the A valve 21 and the B valve 22, the bottom of the high-efficiency clarifier 6 is provided with a sludge discharge pipeline 26, one end of the sludge discharge pipeline 26 is connected with an outlet at the bottom of the high-efficiency clarifier 6, the other end of the sludge discharge pipeline 26 is provided with a sludge tank 27, the process water system 19 is connected with the reactor 5, a sludge delivery pump 28 is arranged on a pipe section between the sludge dewatering machine 20 and the sludge pool 27, one end of the B pipeline 18 is connected on the pipe section between the process water system 19 and the reactor 5, the other end of the B pipeline 18 is connected with a sludge discharge pipeline 26, and the bottom of the sludge dewatering machine 20 is provided with an electric sludge hopper 29; the effluent of the high-efficiency clarifier 6 is qualified, the valve B22 is opened, the effluent enters the pipeline A17 through the water outlet pipe 25 of the high-efficiency clarifier and is conveyed to the clean water tank 7, the effluent of the high-efficiency clarifier 6 is unqualified, the valve A21 is opened, the valve B22 is closed, and the effluent is enabled to flow back to the reactor 5 through the pipeline A17 for secondary reaction; a wastewater adjusting tank stirrer 30 is arranged in the wastewater adjusting tank 4, a reactor stirrer 31 is arranged in the reactor 5, a chemical feeding machine 32 is arranged at the top of the reactor 5, an A aeration device 33 is arranged in the clean water tank 7, a B aeration device 34 is arranged in the sludge tank 27, an A aeration pipe 35 is arranged on the A aeration device 33, one end of the A aeration pipe 35 is connected with the A aeration device 33, the other end of the A aeration pipe 35 is provided with a Roots blower 36, a B aeration pipe 37 is arranged on the B aeration device 34, one end of the B aeration pipe 37 is connected with the B aeration device 34, and the other end of the B aeration pipe 37 is connected with the Roots blower 36; the heat exchanger 8 is provided with a cold water inlet pipe 38, a cold water outlet pipe 39, a hot water inlet pipe 40 and a hot water outlet pipe 41, the cold water inlet pipe 38 is connected with the side wall of the clean water tank 7, the cold water outlet pipe 39 is connected with the top inlet of the degassing tower 9, one end of the hot water outlet pipe 41 is connected with the heat exchanger 8, the other end of the hot water outlet pipe 41 is provided with a circulating water supplementing system 42, and the cold water inlet pipe 38 is provided with an acid adding device 43 and a scale inhibitor adding device 44; the evaporation decrement system 2 further comprises a distilled water tank 45, the bottom outlet of the distilled water tank 45 is connected with the hot water inlet pipe 40, a distilled water pump 46 is arranged on a pipe section between the bottom outlet of the distilled water tank 45 and the hot water inlet pipe 40, and a C pipeline 47 and a D pipeline 48 are arranged at the top of the distilled water tank 45; an E pipeline 49 and an F pipeline 50 are arranged between the degassing tower 9 and the falling-film evaporator 10, one end of a C pipeline 47 is connected with the top of the distilled water tank 45, the other end of the C pipeline 47 is connected with the E pipeline 49, one end of a D pipeline 48 is connected with the top of the distilled water tank 45, and the other end of the D pipeline 48 is connected with the falling-film evaporator 10; the falling-film evaporator 10 is provided with a seed crystal feeding device 51, one side of the falling-film evaporator 10 is connected with a demister 52 and a vapor compressor 53 through pipelines, the demister 52 is connected with the vapor compressor 53 through a pipeline, an outlet part of the vapor compressor 53 is connected with a side wall pipeline of the falling-film evaporator 10, the falling-film evaporator 10 is provided with an evaporator circulating pipe 54, one end of the evaporator circulating pipe 54 is connected with the top of the falling-film evaporator 10, the other end of the evaporator circulating pipe 54 is connected with the bottom of the falling-film evaporator 10, the evaporator circulating pipe 54 is provided with a circulating pump 55, and an alkali feeding device 56 and a defoaming agent feeding device 57 are arranged on a pipe section of the; the evaporation decrement system 2 further comprises a seed crystal circulating pipe 58 and a plant area steam system 77, wherein the outlet of the seed crystal circulating pipe 58 is connected to the inlet pipeline of the circulating pump 55, the inlet of the seed crystal circulating pipe 58 is connected to the pipe section between the concentrated solution pump 16 and the concentrated solution tank 14, the seed crystal circulating pipe 58 is provided with a cyclone separator 59, the cyclone separator 59 is provided with a G pipeline 60, an H pipeline 61 and an I pipeline 62, wherein the bottom of the cyclone separator 59 is connected with the seed circulation pipe 58 through a G pipeline 60, the top of the cyclone separator 59 is connected with the top of the concentrated solution tank 11 through the H pipeline 61, one end of the I pipeline 62 is connected with a pipe section between the outlet of the seed circulation pipe 58 and the circulating pump 55, the other end of the I pipeline 62 is connected with the inlet of the cyclone separator 59, a cyclone separator pump 63 is arranged on the I pipeline 62, and a plant steam system 77 is connected with a pipe section between the outlet of the vapor compressor 53 and the side wall of the falling film evaporator 10 through a pipeline.

Example 9 of the invention: a desulfurization wastewater zero discharge system comprises a pretreatment system 1, an evaporation decrement system 2 and a high-temperature bypass flue drying system 3, wherein the pretreatment system 1 comprises a wastewater adjusting tank 4, a reactor 5, a high-efficiency clarifier 6 and a clean water tank 7 which are sequentially connected through a pipeline, the evaporation decrement system 2 comprises a heat exchanger 8, a degassing tower 9, a falling film evaporator 10 and a concentrated solution tank 11 which are sequentially connected through a pipeline, the high-temperature bypass flue drying system 3 comprises an SCR (selective catalytic reduction) reactor 12, a spray drying tower 13 and a concentrated solution tank 14 which are sequentially connected through a pipeline, the clean water tank 7 is connected with the heat exchanger 8 through a pipeline, a concentrated system conveying pump 15 is arranged on a pipe section between the clean water tank 7 and the heat exchanger 8, the concentrated solution tank 11 is connected with the concentrated solution tank 14 through a pipeline, and a concentrated solution pump 16 is arranged on a pipe section between the concentrated solution; the pretreatment system 1 also comprises an A pipeline 17, a B pipeline 18, a process water system 19 and a sludge dewatering machine 20, wherein the A pipeline 17 is provided with an A valve 21 and a B valve 22, the reactor 5 is connected with the clean water tank 7 through the A pipeline 17, a pipe section between the wastewater adjusting tank 4 and the reactor 5 is provided with a wastewater delivery pump 23, a pipe section between the reactor 5 and the high-efficiency clarifier 6 is provided with a wastewater lift pump 24, the high-efficiency clarifier 6 is provided with a high-efficiency clarifier water outlet pipe 25, the high-efficiency clarifier water outlet pipe 25 is connected with the pipe section between the A valve 21 and the B valve 22, the bottom of the high-efficiency clarifier 6 is provided with a sludge discharge pipeline 26, one end of the sludge discharge pipeline 26 is connected with an outlet at the bottom of the high-efficiency clarifier 6, the other end of the sludge discharge pipeline 26 is provided with a sludge tank 27, the process water system 19 is connected with the reactor 5, a sludge delivery pump 28 is arranged on a pipe section between the sludge dewatering machine 20 and the sludge pool 27, one end of the B pipeline 18 is connected on the pipe section between the process water system 19 and the reactor 5, the other end of the B pipeline 18 is connected with a sludge discharge pipeline 26, and the bottom of the sludge dewatering machine 20 is provided with an electric sludge hopper 29; the effluent of the high-efficiency clarifier 6 is qualified, the valve B22 is opened, the effluent enters the pipeline A17 through the water outlet pipe 25 of the high-efficiency clarifier and is conveyed to the clean water tank 7, the effluent of the high-efficiency clarifier 6 is unqualified, the valve A21 is opened, the valve B22 is closed, and the effluent is enabled to flow back to the reactor 5 through the pipeline A17 for secondary reaction; a wastewater adjusting tank stirrer 30 is arranged in the wastewater adjusting tank 4, a reactor stirrer 31 is arranged in the reactor 5, a chemical feeding machine 32 is arranged at the top of the reactor 5, an A aeration device 33 is arranged in the clean water tank 7, a B aeration device 34 is arranged in the sludge tank 27, an A aeration pipe 35 is arranged on the A aeration device 33, one end of the A aeration pipe 35 is connected with the A aeration device 33, the other end of the A aeration pipe 35 is provided with a Roots blower 36, a B aeration pipe 37 is arranged on the B aeration device 34, one end of the B aeration pipe 37 is connected with the B aeration device 34, and the other end of the B aeration pipe 37 is connected with the Roots blower 36; the heat exchanger 8 is provided with a cold water inlet pipe 38, a cold water outlet pipe 39, a hot water inlet pipe 40 and a hot water outlet pipe 41, the cold water inlet pipe 38 is connected with the side wall of the clean water tank 7, the cold water outlet pipe 39 is connected with the top inlet of the degassing tower 9, one end of the hot water outlet pipe 41 is connected with the heat exchanger 8, the other end of the hot water outlet pipe 41 is provided with a circulating water supplementing system 42, and the cold water inlet pipe 38 is provided with an acid adding device 43 and a scale inhibitor adding device 44; the evaporation decrement system 2 further comprises a distilled water tank 45, the bottom outlet of the distilled water tank 45 is connected with the hot water inlet pipe 40, a distilled water pump 46 is arranged on a pipe section between the bottom outlet of the distilled water tank 45 and the hot water inlet pipe 40, and a C pipeline 47 and a D pipeline 48 are arranged at the top of the distilled water tank 45; an E pipeline 49 and an F pipeline 50 are arranged between the degassing tower 9 and the falling-film evaporator 10, one end of a C pipeline 47 is connected with the top of the distilled water tank 45, the other end of the C pipeline 47 is connected with the E pipeline 49, one end of a D pipeline 48 is connected with the top of the distilled water tank 45, and the other end of the D pipeline 48 is connected with the falling-film evaporator 10; the falling-film evaporator 10 is provided with a seed crystal feeding device 51, one side of the falling-film evaporator 10 is connected with a demister 52 and a vapor compressor 53 through pipelines, the demister 52 is connected with the vapor compressor 53 through a pipeline, an outlet part of the vapor compressor 53 is connected with a side wall pipeline of the falling-film evaporator 10, the falling-film evaporator 10 is provided with an evaporator circulating pipe 54, one end of the evaporator circulating pipe 54 is connected with the top of the falling-film evaporator 10, the other end of the evaporator circulating pipe 54 is connected with the bottom of the falling-film evaporator 10, the evaporator circulating pipe 54 is provided with a circulating pump 55, and an alkali feeding device 56 and a defoaming agent feeding device 57 are arranged on a pipe section of the; the evaporation decrement system 2 further comprises a seed crystal circulating pipe 58 and a plant area steam system 77, wherein the outlet of the seed crystal circulating pipe 58 is connected to the inlet pipeline of the circulating pump 55, the inlet of the seed crystal circulating pipe 58 is connected to the pipe section between the concentrated solution pump 16 and the concentrated solution tank 14, the seed crystal circulating pipe 58 is provided with a cyclone separator 59, the cyclone separator 59 is provided with a G pipeline 60, an H pipeline 61 and an I pipeline 62, wherein the bottom of the cyclone separator 59 is connected with the seed circulation pipe 58 through a G pipeline 60, the top of the cyclone separator 59 is connected with the top of the concentrated solution tank 11 through the H pipeline 61, one end of the I pipeline 62 is connected with a pipe section between the outlet of the seed circulation pipe 58 and the circulating pump 55, the other end of the I pipeline 62 is connected with the inlet of the cyclone separator 59, a cyclone separator pump 63 is arranged on the I pipeline 62, and a plant steam system 77 is connected with a pipe section between the outlet of the vapor compressor 53 and the side wall of the falling film evaporator 10 through a pipeline; the high-temperature bypass flue drying system 3 further comprises a dust remover 64, an air preheater 65 and a boiler 66 which are sequentially connected, the dust remover 64 is connected with a flue of the air preheater 65, a buffer tank 67 is arranged on a pipe section between the spray drying tower 13 and the concentrated liquid tank 14, a concentrated liquid lifting pump 68 is arranged on the pipe section between the buffer tank 67 and the concentrated liquid tank 14, a bottom outlet pipeline of the spray drying tower 13 is connected with a slag bin system 69 of a power plant, an ash conveying device 70 is arranged on the pipe section between a bottom outlet of the spray drying tower 13 and the slag bin system 69 of the power plant, a flue gas pipeline A71 is arranged at the top of the spray drying tower 13, a rotary atomizer 72 is arranged in the spray drying tower 13, an inlet electric inserting plate door 73 and an inlet electric adjusting door 74 are arranged on the flue gas pipeline A71, the inlet electric adjusting door 74 is arranged at one end close to the spray drying tower 13, an outlet of the flue gas pipeline A71 is connected with an inlet, the inlet end of the flue gas pipeline A71 is connected to a pipe section between the air preheater 65 and the outlet of the SCR reactor 12, the flue gas pipeline B75 is arranged at the bottom flue gas outlet of the spray drying tower 13, the flue gas pipeline B75 is provided with an outlet electric baffle door 76, one end of the flue gas pipeline B75 is connected with the bottom flue gas outlet of the spray drying tower 13, and the other end of the flue gas pipeline B75 is connected to a flue between the dust remover 64 and the air preheater 65.

s1, opening a wastewater adjusting tank stirrer 30 and a wastewater conveying pump 23, conveying the desulfurization wastewater to a reactor 5 through a pipeline, simultaneously opening a reactor stirrer 31, adding an integrated adsorption flocculant into a dosing machine 32, stirring a mixed solution of the integrated adsorption flocculant and the desulfurization wastewater in the reactor 5 by the reactor stirrer 31, opening a wastewater lifting pump 24, conveying the mixed solution of the integrated adsorption flocculant and the desulfurization wastewater to an efficient clarifier 6 through a pipeline, removing suspended matters in the desulfurization wastewater to enable the suspended matters to be less than or equal to 70mg/L, and obtaining effluent A and sludge;

s2, opening the valve B22, enabling the effluent A to enter the pipeline A17 through the water outlet pipe 25 of the efficient clarifier and be conveyed to the clean water tank 7, conveying the sludge to the sludge tank 27 through the sludge discharge pipeline 26, sequentially opening the aeration device A33, the aeration device B34 and the Roots blower 36, carrying out aeration treatment on the effluent A in the clean water tank 7 by the aeration device A33, carrying out aeration treatment on the sludge in the sludge tank 27 by the aeration device B34, opening the sludge conveying pump 28, conveying the sludge to the sludge dewatering machine 20 through the pipeline for dewatering treatment, and enabling the dewatered sludge to enter the electric sludge bucket 29;

s3, if the suspended matters are larger than 70mg/L, opening the valve A21, closing the valve B22, enabling the effluent A to flow back to the reactor 5 through the pipeline A17 for secondary reaction, enabling the suspended matters in the mixed liquid of the integrated adsorption flocculant and the wastewater to be less than or equal to 70mg/L, then closing the valve A21, opening the valve B22, enabling the effluent A of the secondary reaction to be conveyed to the clean water tank 7 through the pipeline A17, and repeating the step S2;

s4, turning on a conveying pump 15 of a concentration system, conveying pretreated A effluent to a cold water inlet pipe 38, adding acid into the cold water inlet pipe 38 by an acid adding device 43, adding scale inhibitor into the cold water inlet pipe 38 by a scale inhibitor adding device 44, mixing the pretreated A effluent with the acid and the scale inhibitor to obtain A mixed solution, feeding the A mixed solution into a heat exchanger 8 through the cold water inlet pipe 38, performing heat exchange treatment, feeding the A mixed solution into a degassing tower 9 through a cold water outlet pipe 39, performing degassing treatment, removing oxygen, dissolved carbon dioxide and other gases in wastewater to obtain B effluent, feeding the B effluent into a falling film evaporator 10 through an F pipeline 50, adding seed crystals into the falling film evaporator 10 by a seed crystal adding device 51, adding alkali into an evaporator circulating pipe 54 by an alkali adding device 56, adding defoaming agent into the evaporator circulating pipe 54 by a defoaming agent adding device 57, feeding the seed crystals into the evaporator circulating pipe 54 by a defoaming agent circulating pipe 58, opening a circulating pump 55, enabling alkali, a defoaming agent and crystal seeds to enter the falling film evaporator 10 to react with the effluent B, performing evaporation concentration treatment to obtain C effluent, opening a cyclone separator pump 63, enabling the C effluent to enter a cyclone separator 59 through an I pipeline 62, separating the crystal seeds from the C effluent by the cyclone separator 59 to obtain D effluent and E effluent, enabling the D effluent to enter a concentrated solution tank 11 through an H pipeline 61, enabling the E effluent to enter a crystal seed circulating pipe 58 through a G pipeline 60, enabling the E effluent to enter an evaporator circulating pipe 54 through the crystal seed circulating pipe 58, and enabling the E effluent to enter the falling film evaporator 10 under the action of the circulating pump 55;

s5, mixing the effluent E with the effluent B after entering the falling film evaporator 10 to obtain a mixed solution B, and carrying out evaporation concentration treatment again to obtain steam and effluent F;

s6, the steam enters the demister 52 through a pipeline and then enters the re-steam compressor 53, the steam saturation pressure and temperature are increased, the steam with the high-temperature saturation pressure is obtained, the steam with the high-temperature saturation pressure returns to the falling film evaporator 10 through the pipeline for heat exchange treatment and is condensed into distilled water, the distilled water enters the distilled water tank 45 through the D pipeline 48, the distilled water pump 46 is started, the distilled water enters the heat exchanger 8 through the hot water inlet pipe 40 and then enters the circulating water make-up water system 42 through the hot water outlet pipe 41;

s8, turning on the concentrated solution pump 16 to make part of the D effluent in the concentrated solution tank 11 enter the concentrated solution tank 14 and the other part enter the seed crystal circulating pipe 58;

s9, turning on the concentrated solution lift pump 68, conveying the D effluent in the concentrated solution tank 14 to the buffer tank 67 through a pipeline, and buffering the D effluent by the buffer tank 67;

s10, generating high-temperature flue gas when the boiler 66 operates, enabling the high-temperature flue gas to enter the SCR reactor 12 through a pipeline for denitration treatment, opening the inlet electric adjusting door 74 to enable the inlet electric inserting plate door 73 to be opened, enabling the denitrated high-temperature flue gas to enter the spray drying tower 13 through the flue gas pipeline A71, enabling buffered D outlet water to enter the spray drying tower 13 through the pipeline, enabling the D outlet water to be sprayed out in a mist form through the rotary atomizer 72 and be fully mixed with the denitrated high-temperature flue gas to obtain flue gas A and dry matters, opening the outlet electric baffle door 76, enabling the dry matters to enter the dust remover 64 through the flue gas pipeline B75 along with the flue gas A for dust removal treatment, enabling the dry matters which are not taken away by the flue gas A to fall into the ash conveying device 70 and then enter the slag.

The working principle of one embodiment of the invention is as follows: when the device is in a working state, the wastewater adjusting tank stirrer 30 and the wastewater delivery pump 23 are opened, the desulfurization wastewater is delivered to the reactor 5 through a pipeline, the reactor stirrer 31 is opened, the integrated adsorption flocculant is added into the dosing machine 32, the reactor stirrer 31 stirs the mixed liquid of the integrated adsorption flocculant and the desulfurization wastewater in the reactor 5, the wastewater lifting pump 24 is opened, the mixed liquid of the integrated adsorption flocculant and the desulfurization wastewater is delivered to the high-efficiency clarifier 6 through a pipeline, suspended matters in the desulfurization wastewater are removed, the suspended matters are enabled to be less than or equal to 70mg/L, and effluent A and sludge are obtained; opening a valve B22, enabling the A effluent to enter a pipeline A17 through a water outlet pipe 25 of the high-efficiency clarifier and be conveyed to a clean water tank 7, conveying sludge to a sludge tank 27 through a sludge discharge pipeline 26, sequentially opening an aeration device A33, an aeration device B34 and a Roots blower 36, carrying out aeration treatment on the A effluent in the clean water tank 7 by the aeration device A33, carrying out aeration treatment on the sludge in the sludge tank 27 by the aeration device B34, opening a sludge conveying pump 28, conveying the sludge to a sludge dewatering machine 20 through a pipeline for dewatering treatment, and enabling the dewatered sludge to enter an electric sludge hopper 29; if the suspended matter is more than 70mg/L, opening the valve A21, closing the valve B22, enabling the effluent A to flow back to the reactor 5 through the pipeline A17 for secondary reaction, enabling the suspended matter in the mixed liquid of the integrated adsorption flocculant and the wastewater to be less than or equal to 70mg/L, then closing the valve A21, opening the valve B22, enabling the effluent A of the secondary reaction to be conveyed to the clean water tank 7 through the pipeline A17, and repeating the previous step; opening a conveying pump 15 of a concentration system, conveying pretreated A effluent to a cold water inlet pipe 38, adding acid into the cold water inlet pipe 38 by an acid adding device 43, adding scale inhibitor into the cold water inlet pipe 38 by a scale inhibitor adding device 44, mixing the pretreated A effluent with acid and the scale inhibitor to obtain A mixed solution, feeding the A mixed solution into a heat exchanger 8 through the cold water inlet pipe 38, after heat exchange treatment, feeding the A mixed solution into a degassing tower 9 through a cold water outlet pipe 39, degassing, removing oxygen, dissolved carbon dioxide and other gases in wastewater to obtain B effluent, feeding the B effluent into a falling film evaporator 10 through an F pipeline 50, adding seed crystals into the falling film evaporator 10 by a seed crystal adding device 51, adding alkali into an evaporator circulating pipe 54 by an alkali adding device 56, adding defoaming agent into the evaporator circulating pipe 54 by a defoaming agent adding device 57, feeding defoaming agent into the evaporator circulating pipe 54 by the seed crystal circulating pipe 58, opening a circulating pump 55, enabling alkali, a defoaming agent and crystal seeds to enter the falling film evaporator 10 to react with the effluent B, performing evaporation concentration treatment to obtain C effluent, opening a cyclone separator pump 63, enabling the C effluent to enter a cyclone separator 59 through an I pipeline 62, separating the crystal seeds from the C effluent by the cyclone separator 59 to obtain D effluent and E effluent, enabling the D effluent to enter a concentrated solution tank 11 through an H pipeline 61, enabling the E effluent to enter a crystal seed circulating pipe 58 through a G pipeline 60, enabling the E effluent to enter an evaporator circulating pipe 54 through the crystal seed circulating pipe 58, and enabling the E effluent to enter the falling film evaporator 10 under the action of the circulating pump 55; the effluent E enters a falling film evaporator 10 and then is mixed with the effluent B to obtain a mixed solution B, and evaporation concentration treatment is carried out again to obtain steam and effluent F; steam enters a demister 52 through a pipeline and then enters a re-steam compressor 53, the steam saturation pressure and temperature are increased, steam with high temperature saturation pressure is obtained, the steam with high temperature saturation pressure returns to the falling film evaporator 10 through the pipeline for heat exchange treatment and is condensed into distilled water, the distilled water enters a distilled water tank 45 through a D pipeline 48, a distilled water pump 46 is started, the distilled water enters a heat exchanger 8 through a hot water inlet pipe 40 and then enters a circulating water make-up water system 42 through a hot water outlet pipe 41; opening the concentrated solution pump 16 to enable part of the water D in the concentrated solution tank 11 to enter the concentrated solution tank 14 and the other part of the water D to enter the seed crystal circulating pipe 58; opening a concentrated solution lifting pump 68, conveying the D effluent in the concentrated solution tank 14 to a buffer tank 67 through a pipeline, and buffering the D effluent by the buffer tank 67; the boiler 66 generates high-temperature flue gas during operation, the high-temperature flue gas enters the SCR reactor 12 through a pipeline for denitration treatment, the inlet electric adjusting door 74 is opened to open the inlet electric inserting plate door 73, the denitrated high-temperature flue gas enters the spray drying tower 13 through the A flue gas pipeline 71, then the buffered D outlet water enters the spray drying tower 13 through the pipeline, the D outlet water is sprayed out in a mist manner through the rotary atomizer 72 and is fully mixed with the denitrated high-temperature flue gas to obtain the A flue gas and dry matters, the outlet electric baffle door 76 is opened, the dry matters enter the dust remover 64 through the B flue gas pipeline 75 along with the A flue gas for dust removal treatment, and the dry matters which are not taken away by the A flue gas fall into the ash conveying device 70 and then enter the slag bin system 69 of the power plant through the.

Claims

1. A desulfurization wastewater zero-discharge system is characterized by comprising a pretreatment system (1), an evaporation decrement system (2) and a high-temperature bypass flue drying system (3), wherein the pretreatment system (1) comprises a wastewater adjusting tank (4), a reactor (5), a high-efficiency clarifier (6) and a clean water tank (7) which are sequentially connected through pipelines, the evaporation decrement system (2) comprises a heat exchanger (8), a degassing tower (9), a falling-film evaporator (10) and a concentrated solution tank (11) which are sequentially connected through pipelines, the high-temperature bypass flue drying system (3) comprises an SCR reactor (12), a spray drying tower (13) and a concentrated solution tank (14) which are sequentially connected through pipelines, the clean water tank (7) is connected with the heat exchanger (8) through pipelines, and a concentrated system delivery pump (15) is arranged between the clean water tank (7) and the heat exchanger (8), the concentrated solution tank (11) is connected with the concentrated solution tank (14) through a pipeline, and a concentrated solution pump (16) is arranged on a pipe section between the concentrated solution tank (11) and the concentrated solution tank (14).

2. The desulfurization wastewater zero-discharge system according to claim 1, characterized in that the pretreatment system (1) further comprises an A pipeline (17), a B pipeline (18), a process water system (19) and a sludge dewatering machine (20), the A pipeline (17) is provided with an A valve (21) and a B valve (22), the reactor (5) is connected with the clean water tank (7) through the A pipeline (17), a wastewater delivery pump (23) is arranged on a pipe section between the wastewater adjusting tank (4) and the reactor (5), a wastewater lift pump (24) is arranged on a pipe section between the reactor (5) and the high-efficiency clarifier (6), the high-efficiency clarifier (6) is provided with a high-efficiency clarifier water outlet pipe (25), the high-efficiency clarifier water outlet pipe (25) is connected to a pipe section between the A valve (21) and the B valve (22), the bottom of the high-efficiency clarifier (6) is provided with a sludge discharge pipeline (26), one end of a sludge discharge pipeline (26) is connected with an outlet at the bottom of the high-efficiency clarifier (6), the other end of the sludge discharge pipeline (26) is provided with a sludge tank (27), a process water system (19) is connected with a pipeline of the reactor (5), a sludge dewatering machine (20) is connected with the pipeline of the sludge tank (27), a sludge delivery pump (28) is arranged on a pipe section between the sludge dewatering machine (20) and the sludge tank (27), one end of a B pipeline (18) is connected on the pipe section between the process water system (19) and the reactor (5), the other end of the B pipeline (18) is connected with the sludge discharge pipeline (26), and the bottom of the sludge dewatering machine (20) is provided with an electric sludge hopper (29).

3. The desulfurization wastewater zero-discharge system according to claim 2, characterized in that a wastewater adjusting tank stirrer (30) is arranged in the wastewater adjusting tank (4), a reactor stirrer (31) is arranged in the reactor (5), a chemical feeding machine (32) is arranged at the top of the reactor (5), an A aeration device (33) is arranged in the clean water tank (7), a B aeration device (34) is arranged in the sludge tank (27), an A aeration pipe (35) is arranged on the A aeration device (33), one end of the A aeration pipe (35) is connected with the A aeration device (33), a Roots blower (36) is arranged at the other end of the A aeration pipe (35), a B aeration pipe (37) is arranged on the B aeration device (34), one end of the B aeration pipe (37) is connected with the B aeration device (34), and the other end of the B aeration pipe (37) is connected with the Roots blower (36).

4. The desulfurization wastewater zero discharge system of claim 1, characterized in that a cold water inlet pipe (38), a cold water outlet pipe (39), a hot water inlet pipe (40) and a hot water outlet pipe (41) are arranged on the heat exchanger (8), the cold water inlet pipe (38) is connected with the clean water tank (7), the cold water outlet pipe (39) is connected with the top inlet of the degassing tower (9), one end of the hot water outlet pipe (41) is connected with the heat exchanger (8), the other end of the hot water outlet pipe (41) is provided with a circulating water replenishing system (42), and an acid adding device (43) and a scale inhibitor adding device (44) are arranged on the cold water inlet pipe (38).

5. The desulfurization waste water zero discharge system according to claim 4, characterized in that the evaporation decrement system (2) further comprises a distilled water tank (45), a bottom outlet of the distilled water tank (45) is connected with the hot water inlet pipe (40), a distilled water pump (46) is arranged on a pipe section between the bottom outlet of the distilled water tank (45) and the hot water inlet pipe (40), and a C pipeline (47) and a D pipeline (48) are arranged at the top of the distilled water tank (45).

6. The zero discharge system of desulfurization waste water according to claim 5, characterized in that an E pipeline (49) and an F pipeline (50) are arranged between the degassing tower (9) and the falling film evaporator (10), one end of the C pipeline (47) is connected with the top of the distilled water tank (45), the other end of the C pipeline (47) is connected with the E pipeline (49), one end of the D pipeline (48) is connected with the top of the distilled water tank (45), and the other end of the D pipeline (48) is connected with the falling film evaporator (10).

7. The desulfurization wastewater zero discharge system of claim 1, characterized in that a seed crystal feeding device (51) is arranged on the falling-film evaporator (10), a demister (52) and a vapor compressor (53) are connected to one side of the falling-film evaporator (10) through a pipeline, the demister (52) is connected to the vapor compressor (53) through a pipeline, an outlet portion of the vapor compressor (53) is connected to a side wall pipeline of the falling-film evaporator (10), an evaporator circulating pipe (54) is arranged on the falling-film evaporator (10), one end of the evaporator circulating pipe (54) is connected to the top of the falling-film evaporator (10), the other end of the evaporator circulating pipe (54) is connected to the bottom of the falling-film evaporator (10), a circulating pump (55) is arranged on the evaporator circulating pipe (54), and an alkali feeding device (56) and a defoaming agent feeding device (57) are arranged on a pipe section of the circulating pump (55) and the bottom.

8. The desulfurization waste water zero discharge system according to claim 7, wherein the evaporation abatement system (2) further comprises a seed circulation pipe (58) and a plant steam system (77), an outlet of the seed circulation pipe (58) is connected to an inlet pipeline of the circulation pump (55), an inlet of the seed circulation pipe (58) is connected to a pipe section between the concentrate pump (16) and the concentrate tank (14), a cyclone separator (59) is arranged on the seed circulation pipe (58), a G pipeline (60), an H pipeline (61) and an I pipeline (62) are arranged on the cyclone separator (59), the bottom of the cyclone separator (59) is connected to the seed circulation pipe (58) through the G pipeline (60), the top of the cyclone separator (59) is connected to the top of the concentrate tank (11) through the H pipeline (61), and one end of the I pipeline (62) is connected to a pipe section between an outlet of the seed circulation pipe (58) and the circulation pump (55), the other end of the I pipeline (62) is connected with the inlet of a cyclone separator (59), a cyclone separator pump (63) is arranged on the I pipeline (62), and a factory steam system (77) is connected to a pipeline section between the outlet of the steam compressor (53) and the side wall of the falling film evaporator (10).

9. The desulfurization wastewater zero-emission system of claim 1, characterized in that the high-temperature bypass flue drying system (3) further comprises a dust remover (64), an air preheater (65) and a boiler (66) which are connected in sequence, the dust remover (64) is connected with the flue of the air preheater (65), a buffer tank (67) is arranged on a pipe section between the spray drying tower (13) and the concentrated solution tank (14), a concentrated solution lift pump (68) is arranged on a pipe section between the buffer tank (67) and the concentrated solution tank (14), a power plant slag bin system (69) is connected with a bottom outlet pipeline of the spray drying tower (13), an ash conveying device (70) is arranged on a pipe section between the bottom outlet of the spray drying tower (13) and the power plant slag bin system (69), a flue gas pipeline A (71) is arranged at the top of the spray drying tower (13), and a rotary atomizer (72) is arranged in the spray drying tower (13), an inlet electric inserting plate door (73) and an inlet electric adjusting door (74) are arranged on the A flue gas pipeline (71), the inlet electric adjusting door (74) is arranged at one end close to the spray drying tower (13), the outlet of the A flue gas pipeline (71) is connected with the inlet of the rotary atomizer (72), the inlet end of the A flue gas pipeline (71) is connected to a pipe section between the air preheater (65) and the outlet of the SCR reactor (12), a B flue gas pipeline (75) is arranged at the bottom flue gas outlet of the spray drying tower (13), an outlet electric baffle door (76) is arranged on the B flue gas pipeline (75), one end of the B flue gas pipeline (75) is connected with the bottom flue gas outlet of the spray drying tower (13), and the other end of the B flue gas pipeline (75) is connected to a flue between the dust remover (64) and the air preheater (65).

10. The method for realizing zero discharge of desulfurization wastewater is characterized by comprising the following steps of:

s1, opening a wastewater adjusting tank stirrer (30) and a wastewater delivery pump (23), delivering desulfurization wastewater to a reactor (5) through a pipeline, simultaneously opening a reactor stirrer (31), adding an integrated adsorption flocculant into a dosing machine (32), stirring a mixed solution of the integrated adsorption flocculant and the desulfurization wastewater in the reactor (5) by the reactor stirrer (31), opening a wastewater lifting pump (24), delivering the mixed solution of the integrated adsorption flocculant and the desulfurization wastewater to a high-efficiency clarifier (6) through a pipeline, removing suspended matters in the desulfurization wastewater to enable the suspended matters to be less than or equal to 70mg/L, and obtaining effluent A and sludge;

s2, opening a valve B (22), enabling the A effluent to enter a pipeline A (17) through a water outlet pipe (25) of the efficient clarifier and be conveyed to a clean water tank (7), conveying the sludge to a sludge tank (27) through a sludge discharge pipeline (26), sequentially opening an aeration device A (33), an aeration device B (34) and a Roots blower (36), carrying out aeration treatment on the A effluent in the clean water tank (7) through the aeration device A (33), carrying out aeration treatment on the sludge in the sludge tank (27) through the aeration device B (34), opening a sludge conveying pump (28), conveying the sludge to a sludge dewatering machine (20) through a pipeline for dewatering treatment, and enabling the dewatered sludge to enter an electric sludge hopper (29);

s3, if the suspended matters are larger than 70mg/L, opening the valve A (21), closing the valve B (22), enabling the effluent A to flow back to the reactor (5) through the pipeline A (17) for secondary reaction, enabling the suspended matters in the mixed liquid of the integrated adsorption flocculant and the wastewater to be smaller than or equal to 70mg/L, then closing the valve A (21), opening the valve B (22), enabling the effluent A of the secondary reaction to be conveyed to the clean water tank (7) through the pipeline A (17), and repeating the step S2;

s4, a conveying pump (15) of a concentration system is started, pretreated A effluent is conveyed to a cold water inlet pipe (38), acid is added into the cold water inlet pipe (38) by an acid adding device (43), scale inhibitor is added into the cold water inlet pipe (38) by a scale inhibitor adding device (44), the pretreated A effluent is mixed with the acid and the scale inhibitor to obtain A mixed solution, the A mixed solution enters a heat exchanger (8) through the cold water inlet pipe (38), the A mixed solution enters a degassing tower (9) through a cold water outlet pipe (39) after heat exchange treatment, degassing treatment is carried out to remove oxygen, dissolved carbon dioxide and other gases in waste water to obtain B effluent, the B effluent enters a falling film evaporator (10) through an F pipeline (50), seed crystals are added into the falling film evaporator (10) by a seed crystal adding device (51), and alkali is added into an evaporator circulating pipe (54) by an alkali adding device (56), an antifoaming agent adding device (57) adds an antifoaming agent into an evaporator circulating pipe (54), seed crystals in a seed crystal circulating pipe (58) also enter the evaporator circulating pipe (54), a circulating pump (55) is started to enable alkali, the antifoaming agent and the seed crystals to enter a falling film evaporator (10) to react with effluent B, evaporation concentration treatment is carried out to obtain effluent C, a cyclone separator pump (63) is started to enable the effluent C to enter a cyclone separator (59) through a pipeline I (62), the seed crystals are separated from the effluent C through the cyclone separator (59) to obtain effluent D and effluent E, the effluent D enters a concentrated solution tank (11) through a pipeline H (61), the effluent E enters the seed crystal circulating pipe (58) through a pipeline G (60), and the effluent E enters the evaporator circulating pipe (54) through the seed crystal circulating pipe (58), e, enabling effluent water to enter the falling film evaporator (10) under the action of a circulating pump (55);

s5, mixing the effluent E with the effluent B after entering a falling film evaporator (10) to obtain a mixed solution B, and carrying out evaporation concentration treatment again to obtain steam and effluent F;

s6, the steam enters a demister (52) through a pipeline and then enters a re-steam compressor (53), the steam saturation pressure and temperature are improved, the steam with high temperature saturation pressure is obtained, the steam with high temperature saturation pressure returns to a falling film evaporator (10) through the pipeline for heat exchange treatment and is condensed into distilled water, the distilled water enters a distilled water tank (45) through a D pipeline (48), a distilled water pump (46) is started, the distilled water enters a heat exchanger (8) through a hot water inlet pipe (40), and then enters a circulating water make-up water system (42) through a hot water outlet pipe (41);

s8, opening the concentrated solution pump (16) to make the D effluent water in the concentrated solution tank (11) enter the concentrated solution tank (14) through one part of the pipeline and make the other part enter the seed crystal circulating pipe (58);

s9, turning on a concentrated solution lift pump (68), conveying the D effluent in the concentrated solution tank (14) to a buffer tank (67) through a pipeline, and buffering the D effluent by the buffer tank (67);

s10, high-temperature flue gas is generated when a boiler (66) operates, the high-temperature flue gas enters an SCR reactor (12) through a pipeline for denitration treatment, an inlet electric adjusting door (74) is opened to open an inlet electric inserting plate door (73), the high-temperature flue gas after denitration enters a spray drying tower (13) through an A flue gas pipeline (71), then buffered D effluent enters the spray drying tower (13) through the pipeline, the D effluent is sprayed out in a mist form through a rotary atomizer (72) and is fully mixed with the high-temperature flue gas after denitration to obtain A flue gas and dry matters, an outlet electric baffle door (76) is opened, the dry matters enter a dust remover (64) through a B flue gas pipeline (75) along with the A flue gas for dust removal treatment, and the dry matters not taken away by the A flue gas enter a slag bin system (69) of a power plant through the pipeline after falling into an ash conveying device (70).