Bypass flue drying system and method for adjusting flue gas flow

Abstract

The invention belongs to the technical field of zero discharge of high-salinity wastewater, and particularly relates to a bypass flue drying system and method for adjusting flue gas flow. Comprising a waste water evaporator, a waste water adjusting valve is arranged on an inlet pipeline of the waste water evaporator, a rotary atomizer is arranged on the waste water evaporator, a waste water evaporator side wall thermocouple is installed on the side wall of the waste water evaporator, a waste water evaporator center thermocouple is installed in the waste water evaporator, and a high-temperature bypass flue is connected to an inlet of the waste water evaporator. An outlet of the waste water evaporator is connected with a recovery flue, the high-temperature bypass flue and the recovery flue are both connected with a boiler main flue, an evaporator inlet electric adjusting door is arranged on the high-temperature bypass flue, and a main flue automatic adjusting baffle door is arranged on the boiler main flue. The control module monitors the temperature monitored by the waste water evaporator side wall thermocouple and the waste water evaporator center thermocouple to control opening and closing of the evaporator inlet electric adjusting door and the main flue automatic adjusting baffle door.

Description

Technical Field

[0001] The present invention belongs to the technical field of zero discharge of high-salt wastewater, and in particular relates to a bypass flue drying system and method for regulating flue gas flow rate. Background Art

[0002] In recent years, zero discharge of high-salt wastewater has gradually become one of the focuses of environmental protection work in coal-fired power plants. Since high-salt wastewater is at the end of the cascade utilization of the water system of the whole plant, the water quality is complex and difficult to treat, which is a major environmental hazard. Various processes for zero discharge of high-salt wastewater, such as membrane concentration, evaporation crystallization, low-temperature flue gas waste heat concentration, and high-temperature bypass flue gas drying tower, have emerged and been applied in engineering, providing technical support for the effective treatment of high-salt wastewater. Among them, the high-temperature bypass flue gas drying tower technology has attracted a lot of attention due to its advantages such as simple process equipment, low investment cost, small impact on the main flue system and high degree of automation. It has been applied to coal-fired units from 300,000 kilowatts to 1 million kilowatts.

[0003] The high-temperature bypass flue gas drying tower evaporation unit extracts a portion of the hot flue gas after the SCR device and before the air preheater to the evaporator, and after heat and mass transfer with the high-salt wastewater sprayed in a mist form, the wastewater is evaporated to achieve zero emission. The salt in the wastewater combines with fly ash, part of which falls directly to the bottom of the evaporator cone bucket and is sent to the ash storage through a separate pneumatic ash conveying device; the remaining fly ash is sent back to the main flue with the flue gas at the evaporator outlet and is captured and collected by the electrostatic precipitator after the air preheater.

[0004] Under normal load conditions of the unit, the flue gas resistance of the high-temperature bypass flue gas drying system is small, and the pressure difference of the air preheater is greater than the pressure difference of the drying tower. The air preheater differential pressure can be used to ensure the flue gas volume required by the drying system, and the flue gas discharged from the drying tower can be transported to the main flue before the air preheater to the electrostatic precipitator. However, when the unit is under low load, the air preheater operation resistance is relatively small, and the flue gas volume taken by the differential pressure of the air preheater may be insufficient. In order to ensure the operating stability of the drying tower system, the water volume treated by the high-temperature bypass flue gas drying system can only be reduced, so that the high-temperature bypass flue gas drying tower cannot reach the designed output, resulting in the power plant failing to meet the zero discharge requirements of high-salt wastewater. Summary of the invention

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

[0006] In order to achieve the above object, the present invention adopts the following technical solution: A bypass flue drying system for regulating flue gas flow rate comprises a wastewater evaporator, a wastewater regulating valve is arranged on the inlet pipe of the wastewater evaporator, a rotary atomizer is arranged on the wastewater evaporator, a wastewater evaporator side wall thermocouple is installed on the side wall of the wastewater evaporator, a wastewater evaporator center thermocouple is installed in the wastewater evaporator, a high-temperature bypass flue is connected to the inlet of the wastewater evaporator, a recovery flue is connected to the outlet of the wastewater evaporator, the high-temperature bypass flue and the recovery flue are both connected to the main flue of the boiler, a main flue automatic regulating damper door is arranged on the main flue of the boiler, an evaporator inlet electric regulating door is arranged on the high-temperature bypass flue, the wastewater evaporator side wall thermocouple, the wastewater evaporator center thermocouple, the wastewater regulating valve, the main flue automatic regulating damper door and the electric regulating door are all connected to a control module, and the control module controls the opening of the wastewater regulating valve, the main flue automatic regulating damper door and the electric regulating door according to data monitored by the wastewater evaporator side wall thermocouple and the wastewater evaporator center thermocouple.

[0007] A spray flow meter is also provided on the inlet pipe of the wastewater evaporator, and the spray flow meter is connected to the control module. The control module controls the opening of the wastewater regulating valve according to the flow data monitored by the spray flow meter.

[0008] 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.

[0009] A cone hopper material level meter is arranged in the cone hopper, and the cone hopper material level meter is connected to the control module. The control module controls the opening and closing of the automatic gate valve at the hopper outlet according to the ash height monitored by the cone hopper material level meter.

[0010] The high-temperature bypass flue is provided with an evaporator inlet thermocouple and an evaporator inlet flue gas flowmeter for real-time monitoring of the temperature and flue gas flow in the high-temperature bypass flue. The evaporator inlet thermocouple and the evaporator inlet flue gas flowmeter are connected to the control module.

[0011] An air preheater is also provided on the main flue of the boiler, and the air preheater is used to heat the flue gas in the main flue of the boiler.

[0012] The inlet pipe of the recovery flue is provided with an evaporator outlet pressure transmitter, and the outlet pipe of the recovery flue is provided with a flue outlet pressure transmitter. Both the evaporator outlet pressure transmitter and the flue outlet pressure transmitter are connected to the control module, and the pressure value of the evaporator outlet pressure transmitter should be greater than the pressure value of the flue outlet pressure transmitter. The evaporator outlet thermocouple is used 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.

[0013] The outlet pipe of the recovery flue is provided with a flue outlet pressure transmitter and a flue outlet manual baffle door for real-time monitoring of the pressure and temperature of the flue gas at the outlet of the recovery flue.

[0014] A manual baffle door at the flue inlet is provided on the inlet pipe of the high-temperature bypass flue, and a manual baffle door at the flue outlet is provided on the outlet pipe of the recovery flue. The manual baffle door at the flue inlet and the manual baffle door at the flue outlet are in a closed state when the high-temperature bypass flue and the recovery flue are under maintenance.

[0015] A bypass flue drying method for regulating flue gas flow rate, high-salt wastewater enters a rotary atomizer through a wastewater regulating valve, the high-salt wastewater is sprayed into a wastewater evaporator through the rotary atomizer, a high-temperature bypass flue introduces high-temperature flue gas from a boiler main flue, the high-temperature flue gas enters the wastewater evaporator through an electric regulating door at an evaporator inlet, the high-temperature flue gas and high-salt wastewater are fully contacted and evaporated, and the flue gas passing through the wastewater evaporator re-enters the boiler main flue through a recovery flue at the lower end of the wastewater evaporator.

[0016] Compared with the prior art, the present invention has the following beneficial effects: The invention discloses a bypass flue drying system for regulating flue gas flow rate. The wastewater evaporator side wall thermocouple and central thermocouple integrated in the system can monitor the temperature distribution inside the evaporator in real time. The control module dynamically adjusts the opening of the wastewater regulating valve, the main flue automatic regulating baffle door and the evaporator inlet electric regulating door according to these data to ensure the best heat exchange state between flue gas and wastewater, thereby improving the evaporation efficiency and treatment effect and meeting the emission standards. Through the precise control of the electric regulating door, the flue gas flow entering the wastewater evaporator can be adjusted according to actual needs, which not only ensures sufficient heat supply, but also avoids resource waste, so that the flue gas is It is more efficient and economical to use, and realizes precise control of flue gas and high-salt wastewater; the application of rotary atomizer enhances the atomization effect of wastewater, and combined with the precise control of flow by wastewater regulating valve, ensures that wastewater is evenly dispersed and fully contacted with high-temperature flue gas, thereby increasing evaporation rate, reducing wastewater treatment costs, reducing wastewater residues and improving treatment quality; the integration of control modules realizes real-time monitoring and automatic adjustment of the operating status of the entire system, which can not only respond quickly to changes in the environment or working conditions, but also improve the stability and reliability of the system, reduce human operating errors, and ensure a continuous, efficient and safe wastewater treatment process.

[0017] Furthermore, the cooperation between the wastewater regulating valve and the spray flowmeter realizes the fine adjustment of the wastewater flow entering the rotary atomizer, ensuring the atomization effect and evaporation rate, so that the wastewater can be evenly and fully contacted with the high-temperature flue gas, improving the efficiency and quality of wastewater treatment, and helping to meet strict emission standards.

[0018] Furthermore, the cone hopper level meter and the automatic gate valve at the hopper outlet are integrated with the control module to automatically control the ash removal, ensuring that the ash is discharged in time after accumulating to a certain height, avoiding blockage problems, maintaining the continuous and stable operation of the system, and also reducing manual intervention and improving operation safety.

[0019] Furthermore, the real-time monitoring of the evaporator outlet pressure transmitter and the flue outlet pressure transmitter cooperates with the control module to perform 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.

[0020] Furthermore, the design of the manual baffle door at the flue inlet and the manual baffle door at the flue outlet facilitates the isolation operation of the system during overhaul or maintenance, ensures the safety of the operators, and is conducive to the efficient implementation of daily maintenance work.

[0021] Furthermore, the bypass flue drying method for adjusting the flue gas flow disclosed in the present invention can accurately adjust the high-salt wastewater flow entering the rotary atomizer through the fine control of the wastewater regulating valve, ensure that the wastewater is fully in contact with the high-temperature flue gas in the best atomization state, improve the heat exchange efficiency, accelerate the evaporation process of the wastewater, thereby improving the wastewater treatment speed and treatment quality, and meet the emission standards; the side wall and center thermocouples installed in the wastewater evaporator are used to monitor the temperature in real time, and the control module automatically adjusts the flow and temperature of the flue gas according to the monitoring data to ensure that the most suitable evaporation conditions are maintained in the evaporator. This dynamic adjustment mechanism avoids the energy waste and low processing efficiency caused by excessively high or low temperatures; the method realizes real-time monitoring and dynamic adjustment of the operating status of the entire system through an integrated control module, and can automatically adjust the working status of each component according to actual conditions, such as flue gas flow, wastewater atomization degree, etc., enhances the stability of the system operation and adaptability to changes in external conditions, and ensures the continuity and reliability of the treatment process. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 A flow chart of a bypass flue drying system for regulating flue gas flow; Figure 2 The invention is a control logic diagram of a bypass flue drying system for regulating flue gas flow.

[0023] Label: 1. Wastewater evaporator; 2. Air preheater; 3. Automatic damper door at main flue; 4. Spray flowmeter; 5. Wastewater regulating valve; 6. Rotary atomizer; 7. Manual damper door at flue inlet; 8. High-temperature bypass flue; 9. Flue inlet pressure transmitter; 10. Electric regulating door at evaporator inlet; 11. Evaporator inlet thermocouple; 12. Evaporator inlet flue gas flowmeter; 13. Wastewater evaporator side wall thermocouple; 14. Wastewater evaporator center thermocouple; 15. Cone hopper level meter; 16. Automatic gate valve at hopper outlet; 17. Evaporator outlet pressure transmitter; 18. Evaporator outlet thermocouple; 19. Evaporator outlet electric door; 20. Flue outlet pressure transmitter; 21. Flue outlet manual damper door; 22. Boiler main flue; 23. Recovery flue; 24. Control module. DETAILED DESCRIPTION

[0024] In order to further understand the content of the present invention, the present invention is described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be understood that the embodiments are only for explaining the present invention and are not intended to limit it.

[0025] The embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0026] See also Figure 1 and Figure 2A spray flowmeter 4 and a wastewater regulating valve 5 are arranged on the inlet pipe of the wastewater evaporator 1, a rotary atomizer 6 is arranged on the wastewater evaporator 1, a wastewater evaporator side wall thermocouple 13 is installed on the side wall of the wastewater evaporator 1, a wastewater evaporator center thermocouple 14 is installed in 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, the outlet pipe of the cone hopper is provided with a hopper outlet automatic gate valve 16, and a cone hopper level meter 15 is arranged in 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, and a high-temperature The bypass flue 8 and the recovery flue 23 are both connected to the boiler main flue 22. The boiler main flue 22 is provided with an air preheater 2 and a main flue automatic adjustment damper door 3. The high-temperature bypass flue 8 is provided with a flue inlet manual damper door 7, a flue inlet pressure transmitter 9, an evaporator inlet electric adjustment door 10, an evaporator inlet thermocouple 11 and an evaporator inlet flue gas flowmeter 12; the recovery flue 23 is provided with an evaporator outlet pressure transmitter 17, an evaporator outlet thermocouple 18, an evaporator outlet electric door 19, a flue outlet pressure transmitter 20 and a flue outlet manual damper door 21; among them, the spray flowmeter 4, the wastewater The regulating valve 5, the manual damper door at the flue inlet 7, the flue inlet pressure transmitter 9, the electric regulating door at the evaporator inlet 10, the evaporator inlet thermocouple 11, the flue gas flowmeter at the evaporator inlet 12, the side wall thermocouple 13 of the wastewater evaporator installed on the side wall, the central thermocouple 14 of the wastewater evaporator, the cone hopper level meter 15, the automatic gate valve 16 at the hopper outlet, the main flue automatic regulating damper door 3, the evaporator outlet pressure transmitter 17, the evaporator outlet thermocouple 18, the evaporator outlet electric door 19, the flue outlet pressure transmitter 20 and the manual damper door 21 at the flue outlet are all connected to the control module 24, and the control module 24 controls the flue outlet according to the control module 24. The spray flowmeter 4, the evaporator inlet thermocouple 11, the evaporator inlet flue gas flowmeter 12, the side wall mounted wastewater evaporator side wall thermocouple 13, the wastewater evaporator center thermocouple 14, the cone hopper level meter 15, the evaporator outlet pressure transmitter 17, the evaporator outlet thermocouple 18 and the flue outlet pressure transmitter 20 monitor the temperature, flow and pressure data in real time to control the opening and closing of the wastewater regulating valve 5, the flue inlet manual damper door 7, the evaporator inlet electric regulating door 10, the hopper outlet automatic gate valve 16, the evaporator outlet electric door 19, the flue outlet manual damper door 21 and the main flue automatic regulating damper door 3.

[0027] This embodiment provides a bypass flue drying system and method for adjusting flue gas flow rate, and the specific implementation steps are as follows: The technicians pre-set the initial opening of the wastewater regulating valve 5 according to the treatment volume of the high-salt wastewater and the characteristics of the flue gas, and at the same time adjust the opening ratio of the evaporator inlet electric regulating door 10 on the high-temperature bypass flue 8 and the main flue automatic regulating damper door 3 on the boiler main flue 22; the high-salt wastewater passes through the wastewater regulating valve 5 and is sprayed into the wastewater evaporator 1 after high-speed rotation by the rotary atomizer 6; 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, and enters the wastewater evaporator 1 after passing through the evaporator inlet electric regulating door 10. The high-temperature flue gas fully contacts with the high-salt wastewater sprayed by the rotary atomizer 6 in the wastewater evaporator 1 to evaporate water and form ash, which falls into the cone bucket at the lower end of the wastewater evaporator 1, and the outlet of the cone bucket is connected to the ash discharge system, and the ash is discharged through the ash discharge system. The high-temperature flue gas that does not participate in evaporation in the wastewater evaporator 1 re-enters the boiler main flue 22 through the recovery flue 23 connected to the lower end of the wastewater evaporator 1.

[0028] A cone hopper level meter 15 is provided in the cone hopper at the lower end of the wastewater evaporator 1. The cone hopper level meter 15 monitors the height of the ash falling into the cone hopper in real time. The cone hopper level meter 15 sends the cone hopper ash height data to the control module 24. The control module 24 is preset with a cone hopper level threshold. When the cone hopper ash height is equal to the cone hopper level threshold, the control module 24 controls the hopper outlet automatic gate valve 16 at the outlet below the cone hopper to open. In any case, when the cone hopper ash height is less than the cone hopper level threshold, the hopper outlet automatic gate valve 16 is in a closed state.

[0029] A wastewater evaporator side wall thermocouple 13 is installed on the side wall 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 side wall thermocouple 13 and the wastewater evaporator center thermocouple 14 monitor the side wall temperature and the center temperature of the wastewater evaporator 1 in real time. The wastewater evaporator side wall 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 of the side wall temperature and the center temperature to obtain the average temperature value of the wastewater evaporator. The control module 24 presets a preset temperature value of the wastewater evaporator in advance. The control module 24 determines whether the heating state in the wastewater evaporator 1 can meet the evaporation requirement of high-salt wastewater according to the wastewater evaporator average temperature value and the wastewater evaporator preset temperature value.

[0030] If the average temperature value of the wastewater evaporator is less than the preset temperature value of the wastewater evaporator, it means that the heat inside the wastewater evaporator 1 is insufficient, and the control module 24 controls the electric regulating door 10 at the wastewater evaporator inlet to increase the opening to increase the flue gas introduced from the boiler main flue into the high-temperature bypass flue; after a period of time, if the average temperature value of the side wall temperature and the center temperature of the wastewater evaporator 1 monitored by the wastewater evaporator side wall thermocouple 13 and the wastewater evaporator center thermocouple 14 is still lower than the preset temperature value of the wastewater evaporator, the control module 24 sends an outlet control signal to the evaporator outlet electric door 19 on the recovery flue 23, controls the evaporator outlet electric door 19 to close, and ensures that all the flue gas entering the wastewater evaporator 1 remains in the wastewater until the average temperature value of the wastewater evaporator is equal to the preset temperature value of the wastewater evaporator, and then the control module 24 controls the evaporator outlet electric door 19 to reopen.

[0031] On the contrary, if the average temperature value of the wastewater evaporator is greater than the preset temperature value of the wastewater evaporator, the control module 24 sends a control signal to the wastewater regulating valve 5 on the water inlet pipe of the wastewater evaporator 1, controlling the wastewater regulating valve 5 to increase the opening to increase the flow of high-salt wastewater; a spray flowmeter 4 is also provided on the water inlet pipe of the wastewater evaporator 1, and the spray flowmeter 4 monitors the flow of high-salt wastewater flowing into the wastewater evaporator 1 in real time. The control module 24 performs corresponding calculations according to the preset temperature value of the wastewater evaporator, and sets the adaptation flow value. After the control module 24 controls the wastewater regulating valve 5 to increase the opening, the control module 24 monitors in real time whether the flow value of the spray flowmeter 4 reaches the set adaptation flow value. If the flow value of the spray flowmeter 4 does not reach the set adaptation flow value, the control module 24 controls the wastewater regulating valve 5 to continue to increase the opening until the flow value of the spray flowmeter 4 is greater than or equal to the set adaptation flow value, and then maintains the current opening of the wastewater regulating valve 5.

[0032] Further preferably, in order to ensure smooth passage of flue gas in the recovery flue 23, it is necessary to ensure that the pressure at the outlet of the recovery flue 23 is lower 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 provided 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 0.08-1.5KPa to ensure normal smoke exhaust of 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 door 3 to control the main flue automatic regulating damper door 3 to increase the opening, so that the flue gas at the outlet of the recovery flue 23 passes through the boiler main flue 22 quickly, 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 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 inlet pressure transmitter 9 sends the pressure value in the inlet pipe of the high-temperature bypass flue 8 to the control module 24, and the control module 24 adjusts the opening of the evaporator inlet electric regulating door 10 according to this data; the pressure value of the flue 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 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 evaporator inlet electric regulating door 10 to reduce the opening, so that the pressure value of the flue inlet pressure transmitter 9 increases, until the pressure value of the flue inlet pressure transmitter 9 is greater than the pressure value of the evaporator outlet pressure transmitter 17.

[0033] Further preferably, a manual baffle door 21 at the flue outlet is provided on the outlet pipe of the recovery flue 23, and a manual baffle door 7 at the flue inlet is provided on the inlet pipe of the high-temperature bypass flue 8. During the high-salt wastewater treatment process, the manual baffle door 21 at the flue outlet and the manual baffle door 7 at the flue inlet are in an open state. When the recovery flue 23 and the high-temperature bypass flue 8 need maintenance, the technicians close the manual baffle door 21 at the flue outlet and the manual baffle door 7 at the flue inlet for maintenance.

[0034] Further preferably, an evaporator outlet thermocouple 18 and an evaporator inlet thermocouple 11 are provided on the inlet pipe of the recovery flue 23, and the evaporator inlet thermocouple 11 of the high-temperature bypass flue 8, and the evaporator outlet thermocouple 18 and the evaporator inlet thermocouple 11 are both connected to the control module 24, and the evaporator outlet thermocouple 18 and the evaporator inlet thermocouple 11 send the real-time monitored evaporator inlet and outlet flue gas temperature data to the control module 24, and the control module 24 sends the data to the middle section display for display, and the technician monitors the inlet and outlet flue gas temperatures of the wastewater evaporator 1 by displaying the data on the display screen. In addition, it should be understood that although this specification is described in accordance with the implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other implementation modes that can be understood by those skilled in the art. The above content is only to illustrate the technical idea of ​​the present invention, and cannot be used to limit the protection scope of the present invention. Any changes made on the basis of the technical solution according to the technical idea proposed by the present invention shall fall within the protection scope of the claims of the present invention.

Claims

1. A bypass flue drying system for regulating flue gas flow, characterized in that: It comprises a wastewater evaporator (1), wherein the flue gas inlet of the wastewater evaporator (1) is connected to the bypass flue gas exhaust port of the boiler main flue (22), and the flue gas outlet of the wastewater evaporator (1) is connected to the flue gas recovery port of the boiler main flue (22).

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

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

4. A bypass flue drying system for adjusting flue gas flow rate according to claim 3, characterized in that: The flue gas inlet of the wastewater evaporator (1) is connected to the boiler main flue (22) through a high-temperature bypass flue (8), and an evaporator inlet electric regulating door (10) is provided on the high-temperature bypass flue (8). The evaporator inlet electric regulating door (10) is connected to a control module (24), and the control module (24) controls the opening and closing of the evaporator inlet electric regulating door (10) according to data monitored by a wastewater evaporator side wall thermocouple (13) and a wastewater evaporator center thermocouple (14).

5. A bypass flue drying system for adjusting flue gas flow rate according to claim 4, characterized in that: The high-temperature bypass flue (8) is also provided with an evaporator inlet thermocouple (11) and an evaporator inlet flue gas flowmeter (12). The evaporator inlet thermocouple (11) and the evaporator inlet flue gas flowmeter (12) are connected to a control module (24). The control module (24) controls the opening and closing of the evaporator inlet electric regulating door (10) according to data monitored by the evaporator inlet thermocouple (11) and the evaporator inlet flue gas flowmeter (12). A flue inlet manual damper door (7) is also provided at the entrance of the high-temperature bypass flue (8). The flue inlet manual damper door (7) is in a closed state when the high-temperature bypass flue (8) is under maintenance.

6. A bypass flue drying system for adjusting flue gas flow rate according to claim 5, characterized in that: A spray flow meter (4) is also provided on the water 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 of the wastewater regulating valve (5) according to the flow data monitored by the spray flow meter (4).

7. A bypass flue drying system for adjusting flue gas flow rate according to claim 1, characterized in that: The flue gas outlet of the wastewater evaporator (1) is connected to the main flue (22) of the boiler via a recovery flue (23). The recovery flue (23) is provided with an evaporator outlet pressure transmitter (17), an evaporator outlet thermocouple (18), an evaporator outlet electric door 19 and a flue outlet pressure transmitter (20). The evaporator outlet pressure transmitter (17), the evaporator outlet thermocouple (18), the evaporator outlet electric door 19 and the flue outlet pressure transmitter (20) are all connected to a control module (24). The control module (24) controls the opening and closing of the evaporator outlet electric door 19 according to data monitored by the evaporator outlet pressure transmitter (17), the evaporator outlet thermocouple (18) and the flue outlet pressure transmitter (20). A flue outlet manual damper door (21) is provided at the outlet of the recovery flue (23). The flue outlet manual damper door (21) is in a closed state when the recovery flue (23) is under maintenance.

8. A bypass flue drying system for adjusting flue gas flow rate according to claim 1, characterized in that: The main flue (22) of the boiler is also provided with an air preheater (2) and an automatic regulating door (3). The air preheater (2) is used to heat the flue gas in the main flue (22) of the boiler. The automatic regulating door (3) is connected to a control module (24). The control module (24) controls the flow rate of the high-temperature flue gas entering the wastewater evaporator (1) from the main flue (22) of the boiler.

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

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

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