Desulfurization wastewater hot concentration and flue gas drying zero emission system

Abstract

The utility model provides a desulfurization waste water hot concentration and flue gas drying zero emission system, which comprises a heat source unit, a flue heat exchanger and a steam pressure stabilizing module, and low-temperature flue gas is used as a heat source to heat water to generate low-temperature saturated steam; the multi-effect evaporation unit comprises a plurality of evaporation modules, and the evaporation modules are arranged in series to realize step-by-step heating and concentration of wastewater; the conditioning unit is used for adjusting the pH value of the wastewater concentrated solution; conveying the conditioned wastewater concentrated solution to a flue gas drying unit to be evaporated and dried; the condensation vacuum unit is connected with a steam outlet of the evaporation module at the tail end of the multi-effect evaporation unit and is used for condensing and recycling steam; and the condensate water tank is used for collecting condensate water of each stage of evaporation module of the multi-effect evaporation unit. According to the utility model, a wastewater zero-discharge technology is formed through a high-salinity wastewater zero-discharge technology of coupling low-temperature flash evaporation concentration reduction with rotary atomization drying, so that zero discharge of high-salinity wastewater under various process conditions and unit loads is stably realized, and the operation cost of a zero-discharge system is reduced.

Description

Technical Field

[0001] This utility model relates to the field of wastewater treatment technology, and in particular to a zero-emission system for thermal concentration of desulfurization wastewater and drying of flue gas. Background Technology

[0002] Thermal power plants generate wastewater containing sulfides during operation; this wastewater, known as desulfurization wastewater, is characterized by its complex composition and high treatment difficulty. Traditional treatment methods often employ thermal concentration technology, reducing wastewater volume through evaporation and condensation to achieve volume reduction. However, traditional thermal concentration technology suffers from scaling problems, requiring pretreatment of the wastewater to reduce the content of scale-causing ions such as calcium, magnesium, and sulfate to prevent scaling during high-temperature operation. Furthermore, thermal concentration is energy-intensive, requiring significant energy to generate enough heat to evaporate the water. The system typically requires multiple evaporation and condensation units, along with associated vacuum pumps and other equipment, increasing both initial investment and maintenance costs.

[0003] Thermal concentration technology for desulfurization wastewater that does not require pretreatment can significantly reduce operating costs. Therefore, it is necessary to develop a zero-emission system for thermal concentration of desulfurization wastewater and drying of flue gas that can utilize the waste heat of low-temperature flue gas, eliminating the need for pretreatment of desulfurization wastewater, thereby reducing equipment units and improving the stability of system operation. Utility Model Content

[0004] The purpose of this invention is to provide a zero-emission system for thermal concentration of desulfurization wastewater and drying of flue gas, which effectively solves the problems of high cost, high energy consumption and complex operation in traditional desulfurization wastewater treatment.

[0005] According to one objective of this utility model, this utility model provides a zero-emission system for desulfurization wastewater thermal concentration and flue gas drying, comprising:

[0006] Heat source unit: includes flue heat exchanger and steam pressure stabilization module, which uses low-temperature flue gas as heat source to heat water to generate low-temperature saturated steam;

[0007] Multi-effect evaporation unit: includes multiple evaporation modules, which are arranged in series to achieve staged heating and concentration of wastewater, and finally collect it into the concentrate tank;

[0008] Conditioning unit: Adjusts the pH value of the wastewater concentrate;

[0009] Flue gas drying unit: The conditioned wastewater concentrate is transported to the flue gas drying unit for evaporation and drying;

[0010] Condensation vacuum unit: connected to the steam outlet of the evaporation module at the very end of the multi-effect evaporation unit, to condense and recover the steam;

[0011] Condensate tank: collects the condensate from each stage of the evaporation module in the multi-effect evaporation unit.

[0012] Furthermore, the evaporation module includes a heater, a separator, and a circulating pump connected in sequence, and the separator is provided with a steam outlet and a concentrate outlet.

[0013] Furthermore, the steam outlet above the separator of the evaporation module is connected to the heater of the next-stage evaporation module via a pipe.

[0014] Furthermore, a bypass is provided on the concentrate outlet pipe below the separator of the evaporation module, and a transfer pump is installed on the bypass pipe. The transfer pump is connected to the concentrate pipe of the next stage evaporation module.

[0015] Furthermore, the condensing vacuum unit includes a condenser, a circulating cooling device, and a condensing circulating pump connected in sequence, and the steam outlet of the separator of the evaporation module at the end of the multi-effect evaporation unit is connected to the condenser through a steam pipe.

[0016] Furthermore, the steam outlet of the heater in each of the evaporation modules of the multi-effect evaporation unit is connected to the condenser.

[0017] Furthermore, the heaters of the evaporation modules of the multi-effect evaporation unit are all connected to condensate tanks, and the top steam port of each condensate tank is connected to the inlet steam pipe of the heater of the same stage of the evaporation module through a balance pipe.

[0018] Furthermore, the last stage of the multi-effect evaporation unit has a bypass on the concentrated liquid outlet pipe below the separator of the evaporation module, and a discharge pump is installed on the bypass pipe, which is connected to the subsequent treatment unit.

[0019] Furthermore, the conditioning unit includes an alkali storage tank and an acid storage tank, which are connected to the concentrate tank via alkali pipes and acid pipes, respectively.

[0020] Furthermore, the flue gas drying unit includes an inlet flue, a drying tower, and an outlet flue. The top of the drying tower is equipped with a flue gas distributor, and a wastewater rotary atomizer is installed in the center of the flue gas distributor. Below the bottom cone of the drying tower, there is an ash conveying module, and the ash conveying pipe of the ash conveying module is connected to the power plant slag bin or ash silo. One end of the inlet flue is connected to the main flue outlet of the SCR denitrification system, and the other end of the inlet flue is connected to the flue gas distributor. One end of the outlet flue is connected to the side of the bottom cone of the drying tower, and the other end of the outlet flue is connected to the main flue after the air preheater and before the dust collector.

[0021] This invention provides a solution that enables multi-effect evaporation concentration and volume reduction of desulfurization wastewater without requiring softening pretreatment, thereby reducing the wastewater volume required for subsequent rotary atomization evaporation and drying. By coupling low-temperature flash evaporation concentration and volume reduction with rotary atomization drying for zero-discharge of high-salt wastewater, a complete zero-discharge technology has been developed, enhancing technological adaptability and stably achieving zero discharge of high-salt wastewater under various process conditions and unit loads, thus reducing the operating costs of the zero-discharge system. Attached Figure Description

[0022] To more clearly illustrate the specific embodiments of this utility model or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0023] Figure 1 This is a schematic diagram of the structure of an embodiment of the present utility model;

[0024] In the diagram: 1. Wastewater buffer tank; 2. Feed water pump; 3. Flue heat exchanger; 4. First-effect heater; 5. First-effect separator; 6. First-effect forced circulation pump; 7. Second-effect heater; 8. Second-effect separator; 9. Second-effect forced circulation pump; 10. Third-effect heater; 11. Third-effect separator; 12. Third-effect forced circulation pump; 13. First-end condenser; 14. Intermediate condenser; 15. Tail-end condenser; 16. Balance pipe; 17. Discharge pump; 18. Condenser; 19. Circulating cooling equipment; 20. Condensation circulation pump; 21. Vacuum pump; 22. Concentrate tank; 23. Alkali storage tank; 24. Acid storage tank; 25. Drying tower; 26. Inlet flue; 27. Outlet flue; 28. Flue gas distributor; 29. ​​Steam pressure stabilizing module. Detailed Implementation

[0025] The technical solution of this utility model will be clearly and completely described below with reference to the embodiments. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0026] In the description of this utility model, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this utility model and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model.

[0027] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the stated features. In the description of this utility model, "a plurality of" means two or more, unless otherwise explicitly specified. Furthermore, the terms "installed," "connected," and "linked" should be interpreted broadly; for example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0028] Example 1

[0029] like Figure 1 As shown, a zero-emission system for desulfurization wastewater hydrothermal concentration and flue gas drying includes:

[0030] Heat source unit: The flue heat exchanger 3 and steam pressure stabilizing module 29 are used to generate negative pressure steam by using low temperature flue gas as a heat source. The flue heat exchanger is set in the main flue between the dust collector and the flue gas desulfurization tower. The output steam temperature is 90-95℃ through the de-heating and pressure reducing equipment.

[0031] Multi-effect evaporation unit: includes multiple evaporation modules, which are arranged in series to achieve staged heating and concentration;

[0032] Condensing vacuum unit: connected to the steam outlet of the last evaporation module in the multi-effect evaporation unit, responsible for condensing steam;

[0033] Condensate tank: collects condensate from each stage of the evaporation module;

[0034] Conditioning unit: Adjusts the pH value of the wastewater concentrate. The conditioned wastewater concentrate is then transported to the flue gas drying unit for evaporation and drying. The conditioning unit adjusts the pH value of the concentrate in the concentrate tank to 7.0-10.0 to meet the pH requirements of the influent of the flue gas drying unit.

[0035] Flue gas drying unit: evaporates and dries wastewater.

[0036] Specifically, in this embodiment, each evaporation module consists of a heater, a separator, and a circulation pump, and the separator on each evaporation module is provided with a steam outlet and a concentrate outlet.

[0037] The multi-effect evaporation unit includes a first-effect evaporation module, a second-effect evaporation module, and a third-effect evaporation module. The heat source unit is connected to the first-effect heater 4 of the first-effect evaporation module through a steam pipe.

[0038] The condensing vacuum unit includes a condenser 18, a circulating cooling device 19, and a condensing circulation pump 20. The steam pipe of the separator 11 of the last evaporation module in the multi-effect evaporation unit is connected to the condenser of the condensing vacuum unit. This invention only includes a tail-end vacuum pump 21, and only one vacuum module needs to be set up in the system. The vacuum pipeline of each effect is integrated into the tail-end vacuum module, reducing equipment costs.

[0039] The heater in each effect evaporation module of the multi-effect evaporation unit is connected to the outlet steam pipe of the separator in the last evaporation module. This allows the steam discharged from the heater outlet in each effect evaporation module to enter the condenser of the condensing vacuum unit through the steam pipe of the triple-effect separator 11.

[0040] In the multi-effect evaporation unit, the heater of each evaporation module is connected to a condensate tank, and the steam port at the top of each condensate tank is connected to the inlet steam pipe of the heater of the same effect evaporation module through a balance pipe 16.

[0041] In the multi-effect evaporation unit, the bottom outlet of the intermediate condensate tank is connected to the top of the final stage condensate tank.

[0042] When the evaporation unit is equipped with a multi-effect evaporation module, each effect evaporation module is connected in series; except for the last effect evaporation module, the steam outlet above the separator of each effect evaporation module is connected to the heater shell side of the next effect evaporation module through a pipe.

[0043] Except for the last effect, each evaporation module has a bypass on the concentrate outlet pipe below the separator, and a transfer pump is installed on the bypass pipe. The transfer pump is connected to the concentrate pipe of the next evaporation module. The concentrate obtained from the last evaporation module is transported to the concentrate tank 22 by the discharge pump.

[0044] The conditioning unit adjusts the pH value of the wastewater concentrate. The conditioned wastewater concentrate is then transported to the flue gas drying unit for evaporation and drying. The conditioning unit includes an alkali storage tank 23 and an acid storage tank 24, which are connected to the concentrate tank 22 via alkali pipes and acid pipes, respectively.

[0045] The flue gas drying unit includes an inlet flue, a drying tower 25, and an outlet flue 27. A flue gas distributor 26 is installed at the top of the drying tower 25, and an ash conveying module is installed below the cone at the bottom of the drying tower 25. A wastewater rotary atomizer 28 is installed in the center of the flue gas distributor 26. One end of the inlet flue is connected to the main flue of the SCR denitrification outlet, and the other end of the inlet flue is connected to the flue gas inlet of the flue gas distributor 26. One end of the outlet flue 27 is connected to the side of the cone of the drying tower, and the other end of the outlet flue 27 is connected to the main flue after the air preheater and before the dust collector. The ash conveying pipe of the ash conveying module is connected to the power plant slag bin or ash silo.

[0046] In existing multi-effect evaporation and concentration systems, the feed liquid flows naturally from the previous effect separator to the next effect separator. In order to ensure that the feed liquid can flow smoothly in the pipeline, the concentration of the feed liquid cannot be too high, which reduces the concentration factor of a single effect. If the concentration of the feed liquid is too high, it will cause blockage in the pipeline and reduce the flow capacity.

[0047] To solve this technical problem, this invention adds a transfer pump between each effect of the system. The concentrated liquid from the previous effect is transported to the next effect for further concentration via the transfer pump. This ensures efficient delivery of high-concentration liquids, avoids blockage of the delivery pipeline, and increases the concentration ratio of each effect. A balance pipe 16 is added between the heater 4 and the condenser in each effect to ensure pressure balance between the two, allowing condensate to flow automatically to the condenser.

[0048] A bypass is provided on the concentrate outlet pipe below the separator of the last-effect evaporation module, and a discharge pump 17 is installed on the bypass pipe. The discharge pump 17 is connected to the subsequent treatment unit. The steam outlet above the separator of the last-effect evaporation module is connected to the steam inlet of the condenser through a pipe.

[0049] The multi-effect evaporation unit can be equipped with a single-effect or multi-effect evaporation module.

[0050] The heat source unit is a flue heat exchanger, which can be switched and controlled according to the unit load. The output steam temperature is 90-95℃ through desuperheating and pressure reducing equipment.

[0051] The use of this utility model includes the following steps:

[0052] Wastewater treatment begins: Desulfurization wastewater is first stored in wastewater buffer tank 1;

[0053] Single-effect evaporation module: Wastewater is transported to the heater of the single-effect evaporation module via wastewater supply pump 2, and the wastewater is heated by the steam in the heater;

[0054] Separation of steam and concentrate: The heated wastewater enters the separator for flash evaporation, the steam is discharged, and the concentrate continues to circulate or is transported to the next effect evaporation module;

[0055] Multi-stage concentration process: The steam generated by the first-effect evaporation module is used to heat the wastewater in the second-effect evaporation module, and so on, until the last-effect evaporation module;

[0056] Final treatment of wastewater concentrate: The concentrate obtained from the final evaporation module is pumped to the concentrate tank 22 for further treatment.

[0057] In this embodiment of the invention, an automatic control unit is also provided to realize automatic control of the system; the heat source unit is equipped with instruments such as pressure and temperature; the multi-effect evaporation unit is equipped with instruments such as pressure, temperature, differential pressure, and liquid level, and a density meter is provided at the outlet of the last-effect concentrate; the conditioning unit is equipped with an automatic dosing meter and a pH meter, with the pH meter placed in the concentrate tank; the flue gas drying unit is equipped with instruments such as pressure, temperature, and flue gas flow rate; the wastewater buffer tank is equipped with a liquid level gauge; and the concentrate tank is equipped with a liquid level gauge.

[0058] Specifically, this embodiment includes the following steps:

[0059] Step 1: Desulfurization wastewater enters wastewater buffer tank 1;

[0060] Step 2: The desulfurization wastewater is transported to the first-effect evaporation module via the feed water pump 2. The steam generated by the flue heat exchanger 3 is then transported to the first-effect heater 4 of the first-effect evaporation module, where the desulfurization wastewater is heated by the steam.

[0061] Step 3: The heated desulfurization wastewater enters the first-effect separator 5 of the first-effect evaporation module. The desulfurization wastewater undergoes flash evaporation in the first-effect separator 5. A portion of the wastewater forms steam and is discharged through the steam outlet at the top of the first-effect separator 5. The concentrated liquid formed after flash evaporation is discharged through the concentrated liquid outlet at the bottom of the first-effect separator 5.

[0062] Step 4: The wastewater concentrate is circulated into the first-effect heater 4 via the first-effect forced circulation pump 6 and circulated in the first-effect evaporation module; when it is concentrated to a certain concentration, it is transported to the second-effect evaporation module via the first-effect transfer pump; the steam discharged from the first-effect separator 5 enters the second-effect heater 7 through the pipeline to heat the concentrated wastewater.

[0063] Step 5: Based on the concentration of wastewater in the system, set up a single-effect or multi-effect evaporation module, repeat step 4 multiple times, and the wastewater passes through a double-effect heater 7, a double-effect separator 8, and a double-effect forced circulation pump 9, and further passes through a triple-effect heater 10, a triple-effect separator 11, and a triple-effect forced circulation pump 12. Finally, the wastewater concentrate that meets the requirements is formed by monitoring with an online density meter and discharged to the subsequent treatment system through a discharge pump.

[0064] Step Six: The conditioning unit adjusts the pH value of the wastewater concentrate;

[0065] Step 7: The conditioned wastewater concentrate is transported to the flue gas drying unit for evaporation and drying;

[0066] Step 8: The condensate formed by the condensation of steam in the first-effect heater 4 of the first-effect evaporation module is transported to the first-end condenser 13; the condensate formed in the heaters of the subsequent evaporation modules is transported to the corresponding intermediate condenser 14 and tail-end condenser 15 respectively.

[0067] Step 9: The non-condensable gas in the heater of each evaporation module and the steam in the triple-effect separator 11 of the last evaporation module are condensed by the condensation vacuum unit and discharged into the tail-end condenser tank 15.

[0068] Step 10: The cooling water in the condensate tank can be reused in the power plant's circulating water system or process water system to achieve water resource reuse.

[0069] Example 2

[0070] In this embodiment, a zero-emission system for thermal concentration of desulfurization wastewater and drying of flue gas is described, wherein the multi-effect evaporation unit adopts triple-effect evaporation, and the influent flow rate of desulfurization wastewater is 9.5 m³. 3 The steam generated after passing through the flue heat exchanger at a temperature of 94.5℃ per hour enters the first-effect evaporation module along with the desulfurization wastewater. The wastewater is heated by steam in the first-effect heater and then enters the first-effect separator, where partial evaporation of the wastewater is achieved at -0.07MPa, generating steam at 64.2℃ which enters the second-effect evaporation module. The concentrated liquid is then transported from the first-effect to the second-effect evaporation module via a first-effect transfer pump.

[0071] The desulfurization wastewater, after being concentrated in the first effect, is further concentrated in the second effect. The steam generated in the first effect is used as a heat source to heat the wastewater. The heated wastewater is partially evaporated in the second-effect separator at -0.07MPa, forming 61.6℃ steam which enters the third-effect evaporation module. The concentrated liquid is then transported to the third-effect evaporation module by the second-effect transfer pump.

[0072] The desulfurization wastewater, after being concentrated in the second effect, is further concentrated in the third effect. Steam generated in the second effect is used as a heat source to heat the wastewater. The heated wastewater undergoes partial evaporation at -0.08 MPa in the triple-effect separator, generating 55.9°C steam which enters the condenser of the vacuum condensation unit. The concentrated liquid is then pumped from the third effect to the concentrated liquid tank for further treatment. The density of the concentrated liquid at the third effect outlet reaches 1100 kg / m³. 3 .

[0073] The concentrated desulfurization wastewater is adjusted to a pH of approximately 8.0 by a conditioning unit before being transported to the flue gas drying unit, where 2.5 m³ of water is evaporated. 3 / h, the ash at the bottom of the tower after evaporation is transported to the power plant's slag sil

[0074] This invention significantly improves wastewater treatment efficiency through a series of multi-effect evaporation modules for staged concentration. The introduction of a transfer pump and balancing pipe design optimizes material flow, preventing pipe blockage and system pressure instability, thus enhancing system efficiency and operational stability. Eliminating the need for pretreatment of desulfurization wastewater reduces the use of chemical reagents and pretreatment equipment, lowering operating costs and environmental impact. Utilizing low-temperature flue gas waste heat as a heat source significantly reduces energy consumption.

[0075] This utility model provides a zero-emission system for thermal concentration of desulfurization wastewater and flue gas drying. Through low-temperature flash evaporation concentration using a seed crystal method on high-salt wastewater, it achieves multi-effect evaporation concentration and volume reduction of desulfurization wastewater without requiring softening pretreatment. This reduces the wastewater volume requiring subsequent rotary atomization evaporation and drying. This technology utilizes waste heat from flue gas, eliminating the need for softening. Taking advantage of the characteristics of desulfurization wastewater, it employs a seed crystal method for low-temperature evaporation concentration, reducing softening costs and energy consumption. It solves the problems of high softening costs and high energy consumption for high-salt wastewater, significantly improving the adaptability of the zero-emission system to different wastewater volumes.

[0076] This invention presents an adaptive low-temperature flash evaporation concentration and volume reduction coupled with rotary atomization drying technology for zero discharge of high-salt wastewater. This technology forms a complete set of zero-discharge technologies, improves technical adaptability, stably achieves zero discharge of high-salt wastewater under various process conditions and unit loads, and reduces the operating cost of the zero-discharge system.

[0077] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A zero-emission system for hydrothermal concentration and flue gas drying of desulfurization wastewater, characterized in that, include: Heat source unit: includes flue heat exchanger and steam pressure stabilization module, which uses low-temperature flue gas as heat source to heat water to generate low-temperature saturated steam; Multi-effect evaporation unit: includes multiple evaporation modules, which are arranged in series to achieve staged heating and concentration of wastewater, and finally collect it into the concentrate tank; Conditioning unit: Adjusts the pH value of the wastewater concentrate; Flue gas drying unit: The conditioned wastewater concentrate is transported to the flue gas drying unit for evaporation and drying; Condensation vacuum unit: connected to the steam outlet of the evaporation module at the very end of the multi-effect evaporation unit, to condense and recover the steam; Condensate tank: collects the condensate from each stage of the evaporation module in the multi-effect evaporation unit.

2. The zero-emission system for desulfurization wastewater hydrothermal concentration and flue gas drying according to claim 1, characterized in that, The evaporation module includes a heater, a separator, and a circulating pump connected in sequence. The separator is provided with a steam outlet and a concentrate outlet.

3. The zero-emission system for desulfurization wastewater hydrothermal concentration and flue gas drying according to claim 2, characterized in that, The steam outlet above the separator of the evaporation module is connected to the heater of the next-stage evaporation module via a pipe.

4. The zero-emission system for desulfurization wastewater hydrothermal concentration and flue gas drying according to claim 3, characterized in that, The evaporation module has a bypass on the concentrate outlet pipe below the separator, and a transfer pump is installed on the bypass pipe. The transfer pump is connected to the concentrate pipe of the next stage evaporation module.

5. The zero-emission system for desulfurization wastewater hydrothermal concentration and flue gas drying according to claim 2, characterized in that, The condensing vacuum unit includes a condenser, a circulating cooling device, and a condensing circulating pump connected in sequence. The steam exiting the separator of the evaporation module at the end of the multi-effect evaporation unit is connected to the condenser through a steam pipe.

6. The zero-emission system for desulfurization wastewater hydrothermal concentration and flue gas drying according to claim 5, characterized in that, The steam outlet of the heater in each of the evaporation modules of the multi-effect evaporation unit is connected to the condenser.

7. The zero-emission system for desulfurization wastewater hydrothermal concentration and flue gas drying according to claim 6, characterized in that, The heaters of the evaporation modules of the multi-effect evaporation unit are all connected to condensate tanks, and the top steam port of each condensate tank is connected to the inlet steam pipe of the heater of the same level evaporation module through a balance pipe.

8. The zero-emission system for desulfurization wastewater hydrothermal concentration and flue gas drying according to claim 2, characterized in that, The last stage of the multi-effect evaporation unit has a bypass on the concentrated liquid outlet pipe below the separator of the evaporation module, and a discharge pump is installed on the bypass pipe. The discharge pump is connected to the subsequent treatment unit.

9. The zero-emission system for desulfurization wastewater hydrothermal concentration and flue gas drying according to claim 2, characterized in that, The conditioning unit includes an alkali storage tank and an acid storage tank, which are connected to the concentrate tank via alkali pipes and acid pipes, respectively.

10. The zero-emission system for desulfurization wastewater hydrothermal concentration and flue gas drying according to claim 2, characterized in that, The flue gas drying unit includes an inlet flue, a drying tower, and an outlet flue. The top of the drying tower is equipped with a flue gas distributor, and a wastewater rotary atomizer is installed in the center of the flue gas distributor. Below the cone at the bottom of the drying tower, there is an ash conveying module, and the ash conveying pipe of the ash conveying module is connected to the power plant slag bin or ash silo. One end of the inlet flue is connected to the main flue of the SCR denitrification outlet, and the other end of the inlet flue is connected to the flue gas distributor. One end of the outlet flue is connected to the side of the cone at the bottom of the drying tower, and the other end of the outlet flue is connected to the main flue after the air preheater and before the dust collector.

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