A multi-source wastewater recycling system for a thermal power plant

Abstract

The utility model relates to wastewater recycling technical field, and disclose a kind of thermal power plant multi-source wastewater recycling system. Yellow river water enters industry and fire water pool, after being treated by the device by chemical water treatment unit, salt-free water is prepared after salt removal, while generating high-salt wastewater, low-salt wastewater, low-salt wastewater is treated by industrial wastewater treatment unit and enters reuse water pool, part of which can be used as coal conveying system flushing water, which is reused after being treated by coal-containing wastewater treatment system, and the remaining low-salt wastewater is stored in non-occasional wastewater pool, and the remaining part is mixed with high-salt wastewater and enters desulfurization tower through desulfurization process water tank, which reduces the amount of yellow river water and consumption of low-salt wastewater. In addition, salt-free water enters underground tank as make-up water for intercooler tower, and when the intercooler tower needs to be repaired, it can be recycled to the industrial and fire water pool and can be recycled to the chemical water treatment unit again as make-up water, forming a water recycling system.

Description

Technical Field

[0001] This utility model relates to the field of wastewater recycling technology, and in particular to a multi-source wastewater recycling system for thermal power plants. Background Technology

[0002] Thermal power plants, or coal-fired power plants for short, are factories that use combustibles as fuel to produce electricity. In their production and operation, and with the increasing efforts to protect the Yellow River, how to make more effective use of water resources and how to effectively carry out water conservation work directly affects the production, operation and sustainable development of power companies.

[0003] Regarding the above-mentioned and existing related technologies, the inventors believe that the following defects often exist: Currently, most thermal power plants adopt a model of separating recurring wastewater and non-recurring wastewater in terms of wastewater treatment and reuse. Recurring wastewater is mainly chemical drainage, which is ultimately used as greening water and ash conveying water in ash fields after acid-base neutralization. Its reuse path is relatively narrow. Non-recurring wastewater refers to start-up water, which needs to be treated by sedimentation, filtration and other processes to be used as supplementary water for greening water and ash conveying water in ash fields. Overall, the reuse scenarios are limited. Meanwhile, although the low-salinity wastewater generated by the chemical water treatment system can be used as supplementary water for the coal-containing wastewater treatment system after industrial wastewater treatment, the coal-containing wastewater only requires a small amount of rinsing and spraying in winter, and the amount of supplementary water is extremely small. As a result, a large amount of low-salinity wastewater can only be stored in the non-recurring wastewater pond and slowly consumed, failing to fully realize the value of water resources. In addition, the high-salinity wastewater from the chemical water treatment system is used as desulfurization supplementary water, but due to insufficient water volume, the desulfurization tower also needs to be supplemented with some Yellow River water. Furthermore, when the underground water tank of the indirect cooling tower needs to be repaired, all the water needs to be drained, resulting in a great waste. Utility Model Content

[0004] The technical problem to be solved by this utility model is that the existing technology has the disadvantages of insufficient wastewater reuse, high demand for fresh water sources and waste of maintenance drainage. To this end, we propose a multi-source wastewater recycling system for thermal power plants.

[0005] To achieve the above objectives, this application adopts the following technical solution: a multi-source wastewater recycling system for thermal power plants, comprising: a chemical water treatment unit, a desulfurization tower, an industrial wastewater treatment unit, an underground water tank, a recycled water pool, a coal-containing wastewater treatment unit, a non-recurring wastewater pool, and industrial and fire-fighting water pools; the chemical water treatment unit is connected to the desulfurization tower, the industrial wastewater treatment unit, and the underground water tank; the industrial wastewater treatment unit is connected to the recycled water pool; the recycled water pool is connected to the coal-containing wastewater treatment unit, a greening unit, and an ash storage humidification unit; the underground water tank is connected to an indirect cooling tower and industrial and fire-fighting water pools; and the industrial and fire-fighting water pools are connected to the chemical water treatment unit.

[0006] Preferably, the desulfurization tower is connected to an external Yellow River water source, high-salinity wastewater from a chemical water treatment unit, and low-salinity wastewater from an industrial wastewater treatment unit, thereby reducing the amount of Yellow River water used.

[0007] Preferably, the start-up wastewater from the thermal power plant is transported to a non-recurring wastewater pond and an industrial wastewater treatment unit. The wastewater pond in the industrial wastewater treatment unit is connected to a reclaimed water pond after aeration, sedimentation, and filtration, so that low-salinity wastewater can be recycled and reused.

[0008] Preferably, the wastewater from the low-salt chemical discharge of the thermal power plant is transported to the non-recurring wastewater pool and industrial wastewater treatment unit, and then recycled after being mixed with the unit discharge and start-up discharge; the high-salt wastewater is neutralized by acid and alkali and then sent to the desulfurization tower for reuse to reduce the amount of Yellow River water used.

[0009] Preferably, the chemical water treatment unit, desulfurization tower, industrial wastewater treatment unit, underground water tank, recycled water pool, coal-containing wastewater treatment unit, non-recurring wastewater pool, industrial and fire-fighting water pool, greening unit, ash field conveying unit, indirect cooling tower and external Yellow River water source are all connected by the above-mentioned conveying pipelines to facilitate the flow of wastewater.

[0010] Preferably, the conveying pipeline forms a connecting passage between the chemical water treatment unit, desulfurization tower, industrial wastewater treatment unit, underground water tank, recycled water pool, coal-containing wastewater treatment unit, non-recurring wastewater pool, industrial and fire-fighting water pool, greening unit, ash storage humidification and external Yellow River water source. Each branch node of the conveying pipeline connecting each unit is equipped with a corresponding control valve. By controlling the opening and closing of the valve, the wastewater flow direction and flow rate can be adjusted according to the actual situation, so as to better realize the distribution and recycling of multi-source wastewater.

[0011] The technical effects and advantages of this utility model are as follows:

[0012] In this invention, the device treats Yellow River water through a chemical water treatment unit, producing desalinated water, high-salinity wastewater, and low-salinity wastewater. The low-salinity wastewater, after treatment by an industrial wastewater treatment unit, enters a reuse water tank, where a portion can be used as makeup water for a coal-containing wastewater treatment system. The remaining low-salinity wastewater is stored in a non-recurring wastewater tank. A portion of this wastewater, along with the high-salinity wastewater that can directly enter the desulfurization tower, reduces the amount of Yellow River water used and consumes the low-salinity wastewater to avoid waste. Additionally, the desalinated water enters an underground water tank as makeup water for an indirect cooling tower. Furthermore, when the indirect cooling tower requires maintenance of the underground water tank, the water can be recycled to industrial and fire-fighting water tanks and then back to the chemical water treatment unit as makeup water, forming a water cycle and preventing waste. Attached Figure Description

[0013] The disclosure of this utility model is illustrated with reference to the accompanying drawings. It should be understood that the drawings are for illustrative purposes only and are not intended to limit the scope of protection of this utility model. In the drawings, the same reference numerals are used to refer to the same parts:

[0014] Figure 1 This is a schematic diagram of the multi-source wastewater recycling of this utility model. Detailed Implementation

[0015] It is readily understood that, based on the technical solution of this utility model, those skilled in the art can propose various interchangeable structural methods and implementations without altering the essential spirit of this utility model. Therefore, the following detailed embodiments and accompanying drawings are merely illustrative descriptions of the technical solution of this utility model and should not be considered as the entirety of this utility model or as limitations or restrictions on the technical solution of this utility model.

[0016] Reference Figure 1As shown, this utility model provides a technical solution: a multi-source wastewater recycling system for thermal power plants, comprising: a chemical water treatment unit, a desulfurization tower, an industrial wastewater treatment unit, an underground water tank, a recycled water pool, a coal-containing wastewater treatment unit, a non-recurring wastewater pool, and an industrial and fire-fighting water pool; the chemical water treatment unit is connected to the desulfurization tower, the industrial wastewater treatment unit, and the underground water tank respectively; the industrial wastewater treatment unit is connected to the recycled water pool; the recycled water pool is connected to the coal-containing wastewater treatment unit, a greening unit, and an ash storage humidification unit; the underground water tank is connected to an indirect cooling tower and the industrial and fire-fighting water pool respectively; and the industrial and fire-fighting water pool is connected to the chemical water treatment unit. The treatment process of the chemical water treatment unit in industrial and fire-fighting water tanks mainly involves first adding a coagulant to form flocs, then removing suspended solids, colloids, organic matter, and some microorganisms through sedimentation and filtration. Next, membrane separation and ion exchange technology are used to remove salt ions from the water, simultaneously generating wastewater with varying salinity. During this process, water enters the reverse osmosis system, where water molecules can permeate through the reverse osmosis membrane, while most salt ions are retained. The reverse osmosis permeate then enters the ion exchanger, where cations are replaced by hydrogen ions and anions by hydroxide ions, ultimately yielding demineralized water. After the ion exchange resin becomes ineffective, it is regenerated with dilute acid / alkali. The wastewater discharged after regeneration combines with the salt ions retained in the reverse osmosis system and some water that did not permeate the membrane to form chemically high-salinity wastewater. Meanwhile, the starting flushing of the chemical equipment and various backwash drainages mix to form low-salinity wastewater. Therefore, these wastewaters can be transported to their respective locations via pipelines and control valves. In addition, the unit's drainage is transported to the industrial wastewater treatment unit through the plant's pipeline network. It is mixed with chemical low-salt wastewater and then aerated, settled, and filtered before being transported to the coal-containing wastewater treatment unit to be mixed with the coal-containing wastewater. This solves the problem of water loss during the treatment of coal-containing wastewater due to evaporation and sludge dewatering, which could lead to water shortage and system interruption. It also reduces the consumption of Yellow River water.

[0017] High-salinity chemical wastewater from thermal power plants is directly used as the water source for desulfurization towers. Only when the high-salinity wastewater is insufficient is Yellow River water added to reduce the amount of Yellow River water used.

[0018] Reference Figure 1 As shown in this implementation plan: the desulfurization tower is connected to an external Yellow River water source, high-salinity wastewater output from a chemical water treatment unit, and low-salinity wastewater output from an industrial wastewater treatment unit, thereby reducing the amount of Yellow River water used.

[0019] The unit drainage and start-up wastewater of thermal power plants can be either temporarily stored in non-recurring wastewater ponds or directly treated in industrial wastewater treatment units.

[0020] The chemical water treatment unit, desulfurization tower, industrial wastewater treatment unit, underground water tank, recycled water pool, coal-containing wastewater treatment unit, non-recurring wastewater pool, industrial and fire-fighting water pool, greening unit, ash field conveying unit, indirect cooling tower and external Yellow River water source are all connected by the above-mentioned conveying pipelines to facilitate the flow of wastewater.

[0021] Each set of delivery pipelines is equipped with a control valve at the branch node connecting to each unit, which facilitates control and adjustment.

[0022] Working principle: Using the Yellow River as the external water source for the thermal power plant, the start-up wastewater generated during the startup phase is transported to the non-recurring wastewater pond and industrial wastewater treatment unit. Simultaneously, low-salinity wastewater from the power plant's chemical wastewater is also transported to the non-recurring wastewater pond and industrial wastewater treatment unit. After mixing with the unit wastewater and startup wastewater, the treated water undergoes aeration, sedimentation, and filtration before being used as makeup water for reclaimed water. Meanwhile, high-salinity chemical wastewater undergoes acid-base neutralization treatment and is then used as makeup water for the desulfurization tower, thus realizing the main treatment and utilization methods for existing wastewater. Therefore, based on the above background, the treatment of Yellow River water through a chemical water treatment unit will generate desalinated water, high-salinity wastewater, and low-salinity wastewater. The high-salinity wastewater can be directly transported to the desulfurization tower as part of the desulfurization makeup water. The low-salinity wastewater, after treatment by the industrial wastewater treatment unit, enters a reuse pond. Therefore, the low-salinity wastewater in the reuse pond can serve as makeup water for the coal-containing wastewater treatment system. Furthermore, since coal-containing wastewater only requires a small amount of rinsing and spraying in winter, the makeup water is minimal, and the remaining low-salinity wastewater can only be stored in a non-recurring wastewater pond. Therefore, the unused low-salinity wastewater is also added to the desulfurization tower, thereby reducing the amount of Yellow River water used. This not only further replaces Yellow River water but also increases the consumption of low-salinity wastewater, avoiding waste. Furthermore, the demineralized water entering the underground water tank serves as makeup water for the indirect cooling tower. During maintenance, this water needs to be completely emptied. By optimizing the process, when the indirect cooling tower requires maintenance of the underground water tank, the water that would otherwise need to be emptied can be recycled to industrial and fire-fighting water tanks. These tanks can then supply water to the chemical water treatment unit as makeup water, creating a water resource recycling system that avoids waste and reduces the chemical water treatment unit's reliance on Yellow River water. Therefore, this process significantly reduces the use of Yellow River water and further optimizes wastewater recycling, achieving multi-source wastewater classification and treatment, and better meeting actual production needs.

[0023] The technical scope of this utility model is not limited to the content described above. Those skilled in the art can make various modifications and variations to the above embodiments without departing from the technical concept of this utility model, and all such modifications and variations should fall within the protection scope of this utility model.

Claims

1. A multi-source wastewater recycling system for thermal power plants, characterized in that: It includes chemical water treatment units, desulfurization towers, industrial wastewater treatment units, underground water tanks, reclaimed water pools, coal-containing wastewater treatment units, non-recurring wastewater pools, and industrial and fire-fighting water pools; The chemical water treatment unit is connected to a desulfurization tower, an industrial wastewater treatment unit, and an underground water tank. The industrial wastewater treatment unit is connected to a recycled water tank. The recycled water tank is connected to a coal-containing wastewater treatment unit, a greening unit, and an ash storage humidification unit. The underground water tank is connected to an indirect cooling tower and industrial and fire-fighting water tanks. The industrial and fire-fighting water tanks are connected to the chemical water treatment unit.

2. The multi-source wastewater recycling system for thermal power plants according to claim 1, characterized in that: The Yellow River water source is connected to the inlet pipeline of the industrial and fire-fighting water tank.

3. The multi-source wastewater recycling system for thermal power plants according to claim 1, characterized in that: The desulfurization tower is connected to industrial and fire water tanks for storing high-salinity wastewater from the chemical water treatment unit and low-salinity wastewater from the industrial wastewater treatment unit.

4. The multi-source wastewater recycling system for thermal power plants according to claim 1, characterized in that: During the start-up phase and normal operation of the thermal power plant, wastewater is transported to a non-recurring wastewater pond. The non-recurring wastewater pond then enters the industrial wastewater treatment unit, where it undergoes aeration, sedimentation, and filtration before being connected to the recycled water pond unit.

5. The multi-source wastewater recycling system for thermal power plants according to claim 1, characterized in that: Low-salinity wastewater from the chemical discharge of the thermal power plant is transported to an industrial wastewater treatment unit, which is connected to a reuse water tank; high-salinity wastewater from the chemical discharge of the thermal power plant is transported to a desulfurization tower.

6. The multi-source wastewater recycling system for thermal power plants according to claim 1, characterized in that: The chemical water treatment unit, desulfurization tower, industrial wastewater treatment unit, underground water tank, recycled water pool, coal-containing wastewater treatment unit, non-recurring wastewater pool, industrial and fire-fighting water pool, greening unit, ash storage humidification unit, ash field conveying unit, indirect cooling tower, and external Yellow River water source are all connected through the aforementioned conveying pipelines.

7. The multi-source wastewater recycling system for thermal power plants according to claim 6, characterized in that: Each of the branch nodes connecting the conveying pipelines to each unit is equipped with a corresponding control valve.

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