A bypass flue gas drying system and method for regulating flue gas flow.

Abstract

This invention belongs to the technical field of zero discharge of high-salinity wastewater, specifically relating to a bypass flue drying system and method for regulating flue gas flow. It includes a wastewater evaporator, a wastewater regulating valve installed on the inlet pipe of the evaporator, a rotary atomizer installed on the evaporator, sidewall thermocouples installed on the sidewall of the evaporator, a central thermocouple installed inside the evaporator, a high-temperature bypass flue connected to the inlet of the evaporator, and a recovery flue connected to the outlet of the evaporator. Both the high-temperature bypass flue and the recovery flue are connected to the main flue of the boiler. An electric regulating valve is installed at the inlet of the high-temperature bypass flue, and an automatic regulating damper is installed on the main flue of the boiler. The opening and closing of the electric regulating valve at the inlet and the automatic regulating damper in the main flue are controlled by a control module that monitors the temperatures detected by the sidewall thermocouples and the central thermocouple of the evaporator.

Description

Technical Field

[0001] This invention belongs to the field of zero discharge technology for high-salinity wastewater, specifically relating to a bypass flue gas drying system and method for regulating flue gas flow. Background Technology

[0002] In recent years, zero discharge of high-salinity wastewater has gradually become one of the key focuses of environmental protection work in coal-fired power plants. Because high-salinity wastewater is located at the end of the plant's water system's cascade utilization process, its complex water quality and high treatment difficulty pose a major environmental hazard. Various processes for zero discharge of high-salinity wastewater, such as membrane concentration, evaporation crystallization, low-temperature flue gas waste heat concentration, and high-temperature bypass flue gas drying towers, have emerged and been implemented in engineering projects, providing technical support for the effective treatment of high-salinity wastewater. Among these, the high-temperature bypass flue gas drying tower technology has received considerable attention due to its advantages of simple equipment, low investment cost, minimal impact on the main flue gas system, and high degree of automation, and has been applied in coal-fired units ranging from 300,000 kW to 1,000,000 kW.

[0003] The high-temperature bypass flue gas drying tower evaporation unit draws a portion of the hot flue gas from the SCR unit and before the air preheater into the evaporator. This gas then undergoes heat and mass transfer with the atomized high-salt wastewater, evaporating the wastewater to achieve zero emissions. The salt in the wastewater combines with fly ash. A portion of the fly ash falls directly to the bottom of the evaporator cone and is transported to the ash silo via a separate pneumatic ash conveying device. The remaining fly ash is returned to the main flue along with the flue gas exiting the evaporator and is captured and collected by the electrostatic precipitator after the air preheater.

[0004] Under normal unit load conditions, the flue gas resistance of the high-temperature bypass flue gas drying system is relatively small, and the pressure difference of the air preheater is greater than that of the drying tower. The air preheater differential pressure can be used to ensure the required flue gas volume for the drying system and to transport the flue gas discharged from the drying tower to the main flue before the electrostatic precipitator. However, when the unit is under low load, the air preheater operating resistance is relatively small, and the flue gas volume obtained by utilizing the air preheater differential pressure may be insufficient. To ensure the operational stability of the drying tower system, the water treatment capacity of the high-temperature bypass flue gas drying system must be reduced, causing the high-temperature bypass flue gas drying tower to fail to reach its design output, resulting in the power plant's inability to meet the zero-discharge requirements for high-salinity wastewater. Summary of the Invention

[0005] This invention provides a bypass flue gas drying system and method for adjusting flue gas flow rate, in order to solve the technical problem in the prior art where the treatment efficiency of high-salt wastewater cannot reach the designed treatment capacity due to the inability to accurately control the flow rate of flue gas and wastewater.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] A bypass flue drying system for regulating flue gas flow includes a wastewater evaporator, a wastewater regulating valve installed on the inlet pipe of the wastewater evaporator, a rotary atomizer installed on the wastewater evaporator, a sidewall thermocouple installed on the sidewall of the wastewater evaporator, a central thermocouple installed inside the wastewater evaporator, a high-temperature bypass flue connected to the inlet of the wastewater evaporator, and a recovery flue connected to the outlet of the wastewater evaporator. Both the high-temperature bypass flue and the recovery flue are connected to the main flue of the boiler. An automatic regulating damper is installed on the main flue of the boiler, and an electric regulating damper is installed at the inlet of the evaporator on the high-temperature bypass flue. The sidewall thermocouples, central thermocouples, regulating valve, automatic regulating damper, and electric regulating damper of the main flue are all connected to a control module. The control module controls the opening degree of the wastewater regulating valve, the automatic regulating damper, and the electric regulating damper based on the data monitored by the sidewall thermocouples and central thermocouples.

[0008] A spray flow meter is also installed on the inlet pipe of the wastewater evaporator. The spray flow meter is connected to the control module, which controls the opening of the wastewater regulating valve based on the flow data monitored by the spray flow meter.

[0009] The lower end of the wastewater evaporator is a cone hopper, and the outlet of the cone hopper is connected to the ash discharge system through an automatic gate valve at the hopper outlet.

[0010] The cone hopper is equipped with a cone hopper level gauge, which is connected to the control module. The control module controls the opening and closing of the automatic gate valve at the hopper outlet based on the ash height monitored by the cone hopper level gauge.

[0011] The high-temperature bypass flue is equipped with an evaporator inlet thermocouple and an evaporator inlet flue gas flow meter to monitor the temperature and flow rate of the flue gas in the high-temperature bypass flue in real time. The evaporator inlet thermocouple and the evaporator inlet flue gas flow meter are connected to the control module.

[0012] An air preheater is also installed on the main flue of the boiler, which is used to heat the flue gas in the main flue of the boiler.

[0013] An evaporator outlet pressure transmitter is installed on the inlet pipe of the recovery flue, and a flue outlet pressure transmitter is installed on the outlet pipe of the recovery flue. Both the evaporator outlet pressure transmitter and the flue outlet pressure transmitter are connected to the control module. The pressure value of the evaporator outlet pressure transmitter should be greater than that of the flue outlet pressure transmitter. An evaporator outlet thermocouple is also installed to monitor the pressure and temperature of the flue gas at the inlet of the recovery flue in real time. The evaporator outlet pressure transmitter and the evaporator outlet thermocouple are connected to the control module.

[0014] The outlet pipe of the recovery flue is equipped with a flue outlet pressure transmitter and a flue outlet manual damper to monitor the pressure and temperature of the flue gas at the outlet of the recovery flue in real time.

[0015] The inlet pipe of the high-temperature bypass flue is equipped with a manual flue inlet damper, and the outlet pipe of the recovery flue is equipped with a manual flue outlet damper. The manual flue inlet damper and the manual flue outlet damper are closed when the high-temperature bypass flue and the recovery flue are under maintenance.

[0016] A bypass flue drying method for regulating flue gas flow involves high-salt wastewater entering a rotary atomizer through a wastewater regulating valve, then being sprayed into a wastewater evaporator via the rotary atomizer. High-temperature flue gas is introduced from the main flue of the boiler through a high-temperature bypass flue. The high-temperature flue gas enters the wastewater evaporator through an electric regulating valve at the evaporator inlet, where it fully contacts and evaporates the high-salt wastewater. The flue gas that has passed through the wastewater evaporator re-enters the main flue of the boiler through a recovery flue at the lower end of the wastewater evaporator.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] This invention discloses a bypass flue gas drying system for regulating flue gas flow. The integrated wastewater evaporator sidewall thermocouple and central thermocouple enable real-time monitoring of the internal temperature distribution within the evaporator. Based on this data, the control module dynamically adjusts the opening of the wastewater regulating valve, the main flue automatic regulating damper, and the evaporator inlet electric regulating valve to ensure optimal heat exchange between the flue gas and wastewater, thereby improving evaporation efficiency and treatment effect, and meeting emission standards. Through precise control of the electric regulating valve, the flow rate of flue gas entering the wastewater evaporator can be adjusted according to actual needs, ensuring sufficient heat supply while avoiding resource waste, thus improving the efficiency of the flue gas... The system achieves precise control of flue gas and high-salinity wastewater through more efficient and economical methods. The application of rotary atomizers enhances the atomization effect of wastewater, and combined with precise flow control by wastewater regulating valves, it ensures uniform dispersion of wastewater, full contact with high-temperature flue gas, improved evaporation rate, reduced wastewater treatment costs, reduced wastewater residue, and improved treatment quality. The integrated control module enables real-time monitoring and automatic adjustment of the entire system's operating status, which not only responds quickly to changes in environment or operating conditions but also improves system stability and reliability, reduces human error, and ensures a continuous, efficient, and safe wastewater treatment process.

[0019] Furthermore, the combination of the wastewater regulating valve and the spray flow meter enables precise adjustment of the wastewater flow rate entering the rotary atomizer, ensuring atomization effect and evaporation rate. This allows the wastewater to come into uniform and sufficient contact with the high-temperature flue gas, improving the efficiency and quality of wastewater treatment and helping to meet stringent emission standards.

[0020] Furthermore, the cone hopper level gauge is integrated with the automatic gate valve at the hopper outlet and the control module to automate the discharge of ash, ensuring that ash is discharged in a timely manner after accumulating to a certain height, avoiding blockage problems, maintaining the continuous and stable operation of the system, reducing manual intervention, and improving operational safety.

[0021] Furthermore, the real-time monitoring and control module of the evaporator outlet pressure transmitter and the flue outlet pressure transmitter enables corresponding pressure regulation, ensuring smooth flow of flue gas in the recovery flue, avoiding system instability caused by improper pressure difference, and improving the operating efficiency and safety of the entire bypass flue drying system.

[0022] Furthermore, the design of the manual damper door at the flue inlet and outlet facilitates isolation operations during system inspection or maintenance, ensuring the safety of operators and promoting efficient daily maintenance work.

[0023] Furthermore, this invention discloses a bypass flue drying method for regulating flue gas flow. Through precise control of the wastewater regulating valve, the flow rate of high-salt wastewater entering the rotary atomizer can be accurately adjusted, ensuring that the wastewater is in optimal atomization state and fully contacts the high-temperature flue gas. This improves heat exchange efficiency, accelerates the evaporation process of the wastewater, and thus enhances the wastewater treatment speed and quality, meeting emission standards. The method utilizes thermocouples installed on the side walls and center of the wastewater evaporator to monitor the temperature in real time. The control module automatically adjusts the flow rate and temperature of the flue gas based on the monitoring data, ensuring that the evaporator maintains the most suitable evaporation conditions. This dynamic adjustment mechanism avoids energy waste and low treatment efficiency caused by excessively high or low temperatures. The method, through an integrated control module, achieves real-time monitoring and dynamic adjustment of the entire system's operating status. It can automatically adjust the working status of each component, such as flue gas flow rate and wastewater atomization degree, according to actual conditions, enhancing the stability of system operation and adaptability to changes in external conditions, ensuring the continuity and reliability of the treatment process. Attached Figure Description

[0024] Figure 1 This is a flow chart of a bypass flue drying system for regulating flue gas flow.

[0025] Figure 2 This is a control logic diagram of a bypass flue drying system used to regulate flue gas flow.

[0026] Labels: 1. Wastewater evaporator; 2. Air preheater; 3. Main flue automatic regulating damper; 4. Spray flow meter; 5. Wastewater regulating valve; 6. Rotary atomizer; 7. Flue inlet manual damper; 8. High-temperature bypass flue; 9. Flue inlet pressure transmitter; 10. Evaporator inlet electric regulating valve; 11. Evaporator inlet thermocouple; 12. Evaporator inlet flue gas flow meter; 13. Wastewater evaporator sidewall thermocouple; 14. Wastewater evaporator center thermocouple; 15. Conical hopper level gauge; 16. Hopper outlet automatic gate valve; 17. Evaporator outlet pressure transmitter; 18. Evaporator outlet thermocouple; 19. Evaporator outlet electric gate; 20. Flue outlet pressure transmitter; 21. Flue outlet manual damper; 22. Boiler main flue; 23. Recovery flue; 24. Control module. Detailed Implementation

[0027] To further understand the content of this invention, the invention will be described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the embodiments are merely illustrative and not limiting of the invention.

[0028] The embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0029] See Figure 1 and Figure 2A spray flow meter 4 and a wastewater regulating valve 5 are installed on the inlet pipe of the wastewater evaporator 1. A rotary atomizer 6 is installed on the wastewater evaporator 1. A wastewater evaporator sidewall thermocouple 13 is installed on the side wall of the wastewater evaporator 1. A wastewater evaporator center thermocouple 14 is installed inside the wastewater evaporator 1. The lower end of the wastewater evaporator 1 is a cone hopper. The outlet pipe of the cone hopper is connected to the ash discharge system. An automatic hopper outlet gate valve 16 is installed on the outlet pipe of the cone hopper. A cone hopper level gauge 15 is installed inside the cone hopper. A high-temperature bypass flue 8 is connected to the inlet of the wastewater evaporator 1, and a recovery flue 23 is connected to the outlet of the wastewater evaporator 1. Both the bypass flue 8 and the recovery flue 23 are connected to the main boiler flue 22. The main boiler flue 22 is equipped with an air preheater 2 and an automatic regulating damper 3. The high-temperature bypass flue 8 is equipped with a manual damper 7 at the flue inlet, a flue inlet pressure transmitter 9, an electric regulating damper 10 at the evaporator inlet, a thermocouple 11 at the evaporator inlet, and a flue gas flow meter 12 at the evaporator inlet. The recovery flue 23 is equipped with an evaporator outlet pressure transmitter 17, an evaporator outlet thermocouple 18, an electric damper 19 at the evaporator outlet, a flue outlet pressure transmitter 20, and a manual damper 21 at the flue outlet. Among these, a spray flow meter 4 and a wastewater... 5. Regulating valve at the flue inlet; 7. Manual damper at the flue inlet; 9. Pressure transmitter at the flue inlet; 10. Electric regulating valve at the evaporator inlet; 11. Thermocouple at the evaporator inlet; 12. Flue gas flow meter at the evaporator inlet; 13. Side-wall thermocouple for the wastewater evaporator; 14. Center thermocouple for the wastewater evaporator; 15. Conical hopper level gauge; 16. Automatic slide gate valve at the hopper outlet; 3. Automatic regulating damper at the main flue; 17. Pressure transmitter at the evaporator outlet; 18. Thermocouple at the evaporator outlet; 19. Electric damper at the evaporator outlet; 20. Pressure transmitter at the flue outlet; and 21. Manual damper at the flue outlet are all connected to the control module 24. The control module 24... The spray flow meter 4, evaporator inlet thermocouple 11, evaporator inlet flue gas flow meter 12, sidewall thermocouple of wastewater evaporator 13, center thermocouple of wastewater evaporator 14, cone hopper level gauge 15, evaporator outlet pressure transmitter 17, evaporator outlet thermocouple 18 and flue outlet pressure transmitter 20 monitor temperature, flow and pressure data in real time to control the opening and closing of wastewater regulating valve 5, flue inlet manual damper 7, evaporator inlet electric regulating valve 10, hopper outlet automatic slide gate valve 16, evaporator outlet electric door 19, flue outlet manual damper 21 and main flue automatic regulating damper 3.

[0030] This embodiment provides a bypass flue gas drying system and method for adjusting flue gas flow rate, and its specific implementation steps are as follows:

[0031] Based on the treatment volume of high-salinity wastewater and the characteristics of flue gas, technicians pre-set the initial opening of the wastewater regulating valve 5, and simultaneously adjust the opening ratio of the electric regulating valve 10 at the evaporator inlet on the high-temperature bypass flue 8 and the automatic regulating damper 3 on the main flue of the boiler main flue 22. The high-salinity wastewater is sprayed into the wastewater evaporator 1 after being rotated at high speed by the rotary atomizer 6 through the wastewater regulating valve 5. At the same time, the flue gas in the boiler main flue 22 is heated by the air preheater 2 to form high-temperature flue gas, which is input into the high-temperature bypass flue 8, passes through the electric regulating valve 10 at the evaporator inlet, and enters the wastewater evaporator 1. The high-temperature flue gas fully contacts the high-salinity wastewater sprayed by the rotary atomizer 6 in the wastewater evaporator 1, evaporates the water, and forms soot. The soot falls into the cone at the lower end of the wastewater evaporator 1, and the outlet of the cone is connected to the ash discharge system, through which the soot is discharged. The high-temperature flue gas that did not participate in the evaporation in the wastewater evaporator 1 re-enters the main flue gas 22 of the boiler through the recovery flue 23 connected to the lower end of the wastewater evaporator 1.

[0032] A cone level gauge 15 is installed in the cone hopper at the lower end of the wastewater evaporator 1. The cone level gauge 15 monitors the height of the soot falling into the cone hopper in real time and sends the soot height data to the control module 24. The control module 24 has a preset cone level threshold. When the soot height in the cone hopper is equal to the cone level threshold, the control module 24 controls the automatic gate valve 16 at the outlet of the cone hopper to open. Conversely, when the soot height in the cone hopper is less than the cone level threshold, the automatic gate valve 16 at the outlet of the cone hopper is closed.

[0033] A wastewater evaporator sidewall thermocouple 13 is installed on the sidewall of the wastewater evaporator 1, and a wastewater evaporator center thermocouple 14 is installed in the center of the wastewater evaporator 1. The wastewater evaporator sidewall thermocouple 13 and the wastewater evaporator center thermocouple 14 monitor the sidewall temperature and center temperature of the wastewater evaporator 1 in real time. The wastewater evaporator sidewall thermocouple 13 and the wastewater evaporator center thermocouple 14 send the real-time monitored temperature data to the control module 24. The control module 24 takes the average value of the sidewall temperature and the center temperature to obtain the average temperature value of the wastewater evaporator. The control module 24 has a preset temperature value for the wastewater evaporator. The control module 24 determines whether the heating state inside the wastewater evaporator 1 can meet the evaporation requirements of high-salt wastewater based on the average temperature value and the preset temperature value of the wastewater evaporator.

[0034] If the average temperature of the wastewater evaporator is less than the preset temperature of the wastewater evaporator, it indicates that the heat inside the wastewater evaporator 1 is insufficient. The control module 24 controls the electric regulating valve 10 at the wastewater evaporator inlet to increase the opening of the flue gas introduced from the main flue of the boiler through the high-temperature bypass flue. After a period of time, if the average temperature of the side wall temperature and the center temperature of the wastewater evaporator 1 monitored by the thermocouple 13 on the side wall of the wastewater evaporator and the thermocouple 14 at the center of the wastewater evaporator are still lower than the preset temperature of the wastewater evaporator, the control module 24 sends an outlet control signal to the electric valve 19 at the evaporator outlet on the recovery flue 23 to close the electric valve 19 at the evaporator outlet, ensuring that all the flue gas entering the wastewater evaporator 1 remains in the wastewater until the average temperature of the wastewater evaporator equals the preset temperature of the wastewater evaporator. Then, the control module 24 controls the electric valve 19 at the evaporator outlet to reopen.

[0035] Conversely, if the average temperature of the wastewater evaporator is greater than the preset temperature value, the control module 24 sends a control signal to the wastewater regulating valve 5 on the inlet pipe of the wastewater evaporator 1 to increase the opening of the wastewater regulating valve 5, thereby increasing the flow rate of the high-salt wastewater. A spray flow meter 4 is also installed on the inlet pipe of the wastewater evaporator 1. The spray flow meter 4 monitors the flow rate of the high-salt wastewater flowing into the wastewater evaporator 1 in real time. After the control module 24 performs corresponding calculations based on the preset temperature value of the wastewater evaporator, it sets an appropriate flow rate value. After the control module 24 controls the wastewater regulating valve 5 to increase its opening, the control module 24 monitors in real time whether the flow rate value of the spray flow meter 4 reaches the set appropriate flow rate value. If the flow rate value of the spray flow meter 4 does not reach the set appropriate flow rate value, the control module 24 controls the wastewater regulating valve 5 to continue to increase its opening until the flow rate value of the spray flow meter 4 is greater than or equal to the set appropriate flow rate value, and then maintains the current opening of the wastewater regulating valve 5.

[0036] Further preferably, to ensure smooth passage of flue gas within the recovery flue 23, the pressure at the outlet of the recovery flue 23 must be less than the pressure at the inlet of the recovery flue 23. An evaporator outlet pressure transmitter 17 and a flue outlet pressure transmitter 20 are respectively installed at the inlet and outlet of the recovery flue. The evaporator outlet pressure transmitter 17 and the flue outlet pressure transmitter 20 monitor the pressure values ​​at the inlet and outlet of the recovery flue 23 in real time and send the pressure data to the control module 24. The control module 24 controls the pressure values ​​of the evaporator outlet pressure transmitter 17 and the flue outlet pressure transmitter 20. The pressure value displayed by the evaporator outlet pressure transmitter 17 should be greater than the pressure value displayed by the flue outlet pressure transmitter 20, and the pressure difference between the two should be maintained between 0.08 and 1.5 kPa to ensure normal exhaust from the boiler main flue 22. When the pressure value displayed by the evaporator outlet pressure transmitter 17 is less than or equal to the pressure value displayed by the flue outlet pressure transmitter 20, the control module 24 sends a control signal to the main flue automatic regulating damper 3 to control the main flue automatic regulating damper 3 to increase the opening degree, so that the flue gas at the outlet of the recovery flue 23 passes quickly through the boiler main flue 22, reducing the pressure at the outlet of the recovery flue 23, so that the pressure value displayed by the evaporator outlet pressure transmitter 17 is greater than the pressure value displayed by the flue outlet pressure transmitter 20. The flue gas inlet pressure transmitter 9 on the high-temperature bypass flue 8 monitors the pressure value in the inlet pipe of the high-temperature bypass flue 8 in real time. The flue gas inlet pressure transmitter 9 sends the pressure value in the inlet pipe of the high-temperature bypass flue 8 to the control module 24. The control module 24 adjusts the opening of the electric regulating valve 10 at the evaporator inlet based on this data. The pressure value of the flue gas inlet pressure transmitter 9 should be greater than the pressure value of the evaporator outlet pressure transmitter 17. When the pressure value of the flue gas inlet pressure transmitter 9 is less than or equal to the pressure value of the evaporator outlet pressure transmitter 17, the control module 24 controls the electric regulating valve 10 at the evaporator inlet to reduce its opening, thereby increasing the pressure value of the flue gas inlet pressure transmitter 9 until the pressure value of the flue gas inlet pressure transmitter 9 is greater than the pressure value of the evaporator outlet pressure transmitter 17.

[0037] In a further preferred embodiment, a manual damper 21 is installed on the outlet pipe of the recovery flue 23, and a manual damper 7 is installed on the inlet pipe of the high-temperature bypass flue 8. During the high-salt wastewater treatment process, the manual damper 21 and the manual damper 7 are in the open state. When the recovery flue 23 and the high-temperature bypass flue 8 need maintenance, the technicians will close the manual damper 21 and the manual damper 7 before carrying out the maintenance.

[0038] In a further preferred embodiment, an evaporator outlet thermocouple 18 is installed on the inlet pipe of the recovery flue 23, and an evaporator inlet thermocouple 11 is installed on the high-temperature bypass flue 8. Both the evaporator outlet thermocouple 18 and the evaporator inlet thermocouple 11 are connected to the control module 24. The evaporator outlet thermocouple 18 and the evaporator inlet thermocouple 11 send the real-time monitored flue gas temperature data of the evaporator inlet and outlet to the control module 24. The control module 24 sends the data to the intermediate display for display. Technicians monitor the inlet and outlet flue gas temperatures of the wastewater evaporator 1 by displaying the data on the screen.

[0039] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can be appropriately combined to form other embodiments that can be understood by those skilled in the art. The above content is only for illustrating the technical concept of the present invention and should not be construed as limiting the scope of protection of the present invention. Any modifications made based on the technical concept proposed in this invention shall fall within the scope of protection of the claims of this invention.

Claims

1. A bypass flue drying system for regulating flue gas flow, characterized in that, The system includes a wastewater evaporator (1), whose flue gas inlet is connected to the bypass flue gas outlet of the boiler main flue (22) via a high-temperature bypass flue (8), and an automatic regulating valve (3) is installed on the boiler main flue (22); the wastewater evaporator (1)'s flue gas outlet is connected to the flue gas recovery outlet of the boiler main flue (22) via a recovery flue (23); an evaporator outlet pressure transmitter (17) and a flue outlet pressure transmitter (20) are installed on the recovery flue (23); an evaporator inlet electric regulating valve (10) is installed on the high-temperature bypass flue (8); the wastewater evaporator ( 1) The wastewater evaporator sidewall thermocouple (13) and wastewater evaporator center thermocouple (14) are installed on it; the automatic regulating door (3), evaporator outlet pressure transmitter (17), flue outlet pressure transmitter (20), evaporator inlet electric regulating door (10), wastewater evaporator sidewall thermocouple (13) and wastewater evaporator center thermocouple (14) are all connected to the control module (24); the control module (24) controls the opening degree of the automatic regulating door (3) according to the data monitored by the evaporator outlet pressure transmitter (17) and flue outlet pressure transmitter (20).

2. A bypass flue drying system for regulating flue gas flow according to claim 1, characterized in that, A rotary atomizer (6) is installed at the upper end of the wastewater evaporator (1), and a cone hopper is installed at the lower end of the wastewater evaporator (1). The outlet of the cone hopper is connected to the ash discharge system through the hopper outlet automatic gate valve (16). A cone hopper level gauge (15) is installed inside the cone hopper. The cone hopper level gauge (15) is connected to the control module (24). The control module (24) controls the opening and closing of the hopper outlet automatic gate valve (16) according to the ash height monitored by the cone hopper level gauge (15).

3. A bypass flue drying system for regulating flue gas flow according to claim 2, characterized in that, Wastewater regulating valve (5) is installed on the inlet pipe of the wastewater evaporator (1). The thermocouple (13) on the side wall of the wastewater evaporator and the thermocouple (14) in the center of the wastewater evaporator are connected to the control module (24). The control module (24) controls the opening and closing of the wastewater regulating valve (5).

4. A bypass flue drying system for regulating flue gas flow according to claim 1, characterized in that, The high-temperature bypass flue (8) is also equipped with an evaporator inlet thermocouple (11) and an evaporator inlet flue gas flow meter (12). The evaporator inlet thermocouple (11) and the evaporator inlet flue gas flow meter (12) are connected to the control module (24). The control module (24) controls the opening and closing of the evaporator inlet electric regulating door (10) based on the data monitored by the evaporator inlet thermocouple (11) and the evaporator inlet flue gas flow meter (12).

5. A bypass flue drying system for regulating flue gas flow according to claim 4, characterized in that, A spray flow meter (4) is also installed on the inlet pipe of the wastewater evaporator (1). The spray flow meter (4) is connected to the control module (24). The control module (24) also controls the opening degree of the wastewater regulating valve (5) according to the flow data monitored by the spray flow meter (4).

6. A bypass flue drying system for regulating flue gas flow according to claim 1, characterized in that, An evaporator outlet thermocouple (18) and an evaporator outlet electric door (19) are installed on the recovery flue (23). Both the evaporator outlet thermocouple (18) and the evaporator outlet electric door (19) are connected to the control module (24). The control module (24) controls the opening and closing of the evaporator outlet electric door (19) based on the data monitored by the evaporator outlet thermocouple (18). A flue outlet manual damper door (21) is installed at the outlet of the recovery flue (23). The flue outlet manual damper door (21) is closed when the recovery flue (23) is under maintenance.

7. A bypass flue drying system for regulating flue gas flow according to claim 1, characterized in that, An air preheater (2) is also installed on the main flue of the boiler (22), which is used to heat the flue gas in the main flue of the boiler (22).

8. A method for drying a bypass flue for regulating flue gas flow, characterized in that, A bypass flue drying system for regulating flue gas flow according to any one of claims 1 to 7, wherein the method is as follows: high-salt wastewater enters the wastewater evaporator (1), and high-temperature flue gas is transported from the boiler main flue (22) to the wastewater evaporator (1). The high-temperature flue gas and high-salt wastewater fully contact and evaporate in the wastewater evaporator (1). The flue gas passing through the wastewater evaporator (1) re-enters the boiler main flue (22) through the outlet of the wastewater evaporator (1).

9. A method for drying a bypass flue gas duct for adjusting flue gas flow rate according to claim 8, characterized in that, The control module (24) receives real-time temperature data of the drying reaction in the wastewater evaporator (1) monitored by the side wall thermocouple (13) and the center thermocouple (14) of the wastewater evaporator, and controls the opening of the wastewater regulating valve (5) and the electric regulating gate (10) at the evaporator inlet. When the height of the soot in the cone hopper level gauge (15) at the lower end of the wastewater evaporator (1) reaches the height threshold, the control module (24) controls the automatic gate valve (16) at the hopper outlet to open, and the soot is discharged to the ash discharge system through the automatic gate valve (16) at the hopper outlet.

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