Water resource pollution cascade treatment device for power plant realizing near-zero emission

Abstract

The present application belongs to the field of power plant sewage treatment, and particularly relates to a power plant water resource pollution cascade treatment device achieving near-zero emission, comprising: a cascade treatment pool main body, the top of which is fixedly connected with a fence for protection; a water inlet conversion assembly installed at the water inlet area of the cascade treatment pool main body, the water inlet conversion assembly comprising a multilayer variable-aperture curved surface energy dissipation cover; through the structural design of the water inlet conversion assembly, active conversion and spatial redistribution of the kinetic energy of the inlet water are achieved. Specifically, the multilayer variable-aperture curved surface energy dissipation cover adopts a three-layer nested structure of an inner cover, a middle cover and an outer cover, variable-diameter through holes are arranged on the middle cover in a spiral arrangement, and the hole diameter gradually increases from the center to the edge, so that the water flow forms a rotational velocity gradient field with fast center and slow edge when passing through, thereby constructing a dynamic rotating water curtain wall in the water inlet area and constraining the kinetic energy of the main water flow in the center area of the energy dissipation cover.

Description

Technical Field

[0001] This invention relates to the field of power plant wastewater treatment, specifically a cascade treatment device for power plant water pollution that achieves near-zero emissions. Background Technology

[0002] With increasingly stringent national standards for pollutant emissions from the thermal power industry, the recycling of water resources and near-zero emissions from power plants have become inevitable requirements for the industry's development. As the core structure of a power plant's wastewater treatment system, sedimentation tanks play a crucial role in separating suspended solids and thickening sludge, and their operational stability directly determines the load level of subsequent advanced treatment units and the final effluent quality.

[0003] In actual power plant operations, sedimentation tanks face challenges with distinct industry characteristics: various types of industrial wastewater (including circulating cooling wastewater, pre-treated desulfurization wastewater, and coal-containing wastewater) typically enter sedimentation tanks intermittently and at high flow rates. Furthermore, the drastic load fluctuations under deep peak-shaving conditions cause frequent changes in the sedimentation tank's influent flow rate within a short period. When high-speed water flows into the sedimentation tank from the inlet pipe, the enormous kinetic energy it carries, if not effectively dissipated, will directly impact the stable hydraulic stratification already formed within the tank, triggering secondary suspension of the settled sludge. This phenomenon not only causes a sharp increase in the effluent suspended solids concentration, affecting the operation of subsequent treatment units, but more seriously, the resuspended sludge is lost with the effluent, leading to a drop in sludge level in the sludge thickening zone and a decrease in sludge concentration, creating a vicious cycle of disturbance—floating—loss—inefficient sludge discharge.

[0004] Existing technologies offer several solutions for optimizing sedimentation tank influent: For example, an influent device consisting of a perforated distribution ring and an internally connected cross-shaped distribution pipe at the bottom of the tank. However, this device is only suitable for small sedimentation tanks. For large structures commonly used in power plants with diameters of ten or tens of meters, the outlets still exert considerable impact, making it impossible to achieve a stable influent flow. Another approach involves installing a skirt plate that forms a space between the influent channel and the tank wall, and placing a flow-damping plate below the distribution holes in the annular channel. While this partially eliminates the kinetic energy of the influent, the downward gravity-driven water distribution method is contrary to the upward flow of sedimentation water, causing the area around the sedimentation tank to lose its sedimentation function, reducing the effective sedimentation area, and still disturbing the already settled sludge layer. Other solutions utilize arc-shaped guide plates to reduce flow velocity through the wall effect, or adjust the uniformity of water distribution through a combination of guide plates and adjustable guide windows. However, these solutions only optimize a single influent point and fail to address the problem of the residual kinetic energy continuously disturbing the sludge-water interface after the water enters the sedimentation zone.

[0005] In summary, the existing technical solutions have the following systemic defects: First, most of the influent energy dissipation devices are passive structures, which can only reduce the flow velocity but cannot actively regulate the flow field distribution, and the residual turbulence will still cause continuous disturbance to the mud-water interface; Second, the mud-water interface lacks effective stabilization measures, and the settled sludge may be resuspended under slight disturbance. Summary of the Invention

[0006] To address the shortcomings of existing technologies, such as the potential re-suspension of settled sludge under the impact of incoming water, this invention proposes a cascade treatment device for power plant water pollution that achieves near-zero emissions.

[0007] The technical solution adopted by this invention to solve its technical problem is: a cascade treatment device for power plant water pollution that achieves near-zero emissions, comprising:

[0008] The main body of the cascade treatment pool is fixedly connected to a protective fence on its top;

[0009] The inlet conversion component is installed in the inlet area of ​​the main body of the cascade treatment tank. The inlet conversion component includes a multi-layer variable aperture curved surface energy dissipation cover, which is used to convert the high-speed water flow input from the inlet pipe into a low-speed rotating flow state and form a dynamic water curtain in the inlet area to suppress turbulent diffusion.

[0010] An interface stabilization component is arranged in the mud-water interface layer of the main body of the cascade treatment tank. The interface stabilization component includes multiple flexible turbulence units, which are used to dissipate the residual water kinetic energy transferred to the sludge layer and guide the settled sludge to slide down its surface.

[0011] The induced sludge discharge component is located outside the main body of the cascade treatment tank and is spatially adjacent to the interface stabilization component. The induced sludge discharge component includes a sludge collection tank, a negative pressure sludge discharge pipeline and a negative pressure generating unit, which is used to generate negative pressure during sludge discharge and, with the cooperation of the flexible turbulence unit, discharge the sludge accumulated at the bottom of the tank outside the tank.

[0012] Preferably, the multi-layer variable aperture curved surface energy dissipation cover includes an inner cover, a middle cover, and an outer cover nested from the inside out. The inner cover is a pointed cone shape, used to withstand the impact of incoming water and guide the water flow radially. The middle cover is an inverted bowl shape, with variable diameter through holes arranged in a spiral pattern. The diameter of the variable diameter through holes gradually increases radially from the center to the edge, so that the water flow forms a rotational velocity gradient field when passing through. The outer cover is cylindrical, with vertical flow stabilizing slits on its cylindrical wall.

[0013] Preferably, the flexible flow disturbance unit is a graded density flexible flow disturbance unit, arranged in an array along the direction perpendicular to the water flow. The flexible flow disturbance unit includes a root anchoring section, a middle buffer section and a top flexible section along its axial direction, and the three sections have different hardness gradients. The hardness of the root anchoring section is greater than that of the middle buffer section, and the hardness of the middle buffer section is greater than that of the top flexible section. This is used to form stable support at the bottom and dissipate water flow energy through flexible oscillation at the top.

[0014] Preferably, a stainless steel counterweight core rod is pre-embedded inside the root anchoring section, and the surfaces of the root anchoring section, the middle buffer section and the top flexible section are provided with sludge guiding longitudinal grooves for guiding sludge to slide down, and the bottom of the root anchoring section is provided with a ring plate for fixing to the main body of the cascade treatment tank.

[0015] Preferably, the sludge collection trough is a V-shaped trough arranged along the width of the pool, the root of the flexible turbulence unit is inclined towards the center line of the sludge collection trough, the inclination angle is 10-15 degrees, and a filter screen is provided at the inlet of the negative pressure sludge discharge pipeline.

[0016] Preferably, the negative pressure generating unit includes: a vacuum pump for generating a negative pressure source; a vacuum buffer tank connected to the suction port of the vacuum pump via a pipeline for storing negative pressure energy and stabilizing negative pressure fluctuations; an electromagnetic pulse valve connected between the vacuum buffer tank and the negative pressure sludge discharge pipeline for converting stable negative pressure into pulsed negative pressure; and a PLC controller electrically connected to the inlet flow meter, sludge level gauge, and the electromagnetic pulse valve for controlling the opening and closing sequence of the electromagnetic pulse valve according to the inlet water load or sludge level signal.

[0017] Preferably, the vacuum buffer tank is equipped with a sludge discharge valve at the bottom for periodically discharging the sludge deposited in the tank, and a vacuum safety valve at the top of the vacuum buffer tank for preventing the negative pressure from exceeding the set value.

[0018] Preferably, when the PLC controller detects that the influent flow rate increases instantaneously beyond a set threshold, it triggers the electromagnetic pulse valve to open at a frequency of once per second to form a negative pressure pulse for sludge discharge; when it detects that the sludge level in the sludge collection tank exceeds a set height, it triggers the electromagnetic pulse valve to open for sludge discharge. The PLC controller is connected to the central control room through a communication interface for uploading operating data and receiving remote commands.

[0019] Preferably, the inlet area of ​​the cascade treatment tank is provided with an inlet pipe, and an inlet flow meter is fixedly connected to the inlet pipe. The inlet flow meter is used to monitor the inlet water load of the cascade treatment tank. A support plate for positioning the vacuum pump, vacuum buffer tank and PLC controller is fixedly connected to one side of the cascade treatment tank.

[0020] The advantages of this invention are:

[0021] 1. This invention achieves active conversion and spatial redistribution of the kinetic energy of incoming water through the structural design of the water inlet conversion component. Specifically, the multi-layer variable-aperture curved energy dissipation cover adopts a three-layer nested structure of inner cover, middle cover, and outer cover. The middle cover has spirally arranged variable-diameter through holes with the diameter gradually increasing from the center to the edge, creating a rotational velocity gradient field where the water flow is fast at the center and slow at the edge. This constructs a dynamically rotating water curtain wall in the water inlet area, confining the kinetic energy of the main incoming water flow to the central area of ​​the energy dissipation cover. Compared with existing technologies that only passively block water flow using fixed perforated baffles or simple guide tubes, the water inlet conversion component of this invention can fundamentally eliminate the direct disturbance of the main water body in the sedimentation zone by the incoming water, transforming the flow field in the water inlet area from an impact type to a rotating diffusion type, effectively reducing the turbulence intensity and creating stable hydraulic conditions for subsequent efficient sedimentation.

[0022] 2. This invention achieves flexible protection and sludge guidance at the mud-water interface through the structural design of the interface stabilization component. The graded density flexible turbulence unit is axially configured with three sections of different hardness gradients: a root anchoring section, a middle buffer section, and a top flexible section. The root anchoring section has the highest hardness and is pre-embedded with a stainless steel counterweight mandrel, fixed to the bottom of the tank via a ring plate. The middle buffer section has moderate hardness and elastic bending capability, while the top flexible section has the lowest hardness and extremely high flexibility. When the residual water flow micro-turbulence is transmitted to the mud-water interface, the top flexible section converts the turbulent kinetic energy into mechanical heat energy dissipation through high-frequency, small-amplitude oscillations. The middle buffer section further absorbs energy through elastic bending, constructing an adaptive flexible buffer layer with a thickness of 200-300mm at the mud-water interface. Simultaneously, the sludge guiding longitudinal channels on the unit surface generate a weak pumping effect during the oscillation process, guiding the settled sludge to slide down the channel towards the root. Compared to existing technologies where mechanical scraping with rigid scrapers easily disturbs the sludge layer or where simple static settling offers no resistance to disturbance, the interface stabilization component of this invention reduces the water flow pulsation velocity at the sludge-water interface to below 0.01 m / s, lowers the resuspension rate of settled sludge, and achieves active stabilization control of the sludge-water interface.

[0023] 3. This invention achieves synergistic optimization of precise sludge discharge and secondary disturbance elimination through the structural design of the induced sludge discharge component. The sludge collection trough is a V-shaped trough arranged along the width and length of the pool, with the root of the flexible turbulence unit inclined at an angle of - degrees towards the centerline of the sludge collection trough. The negative pressure generating unit includes a vacuum pump, a vacuum buffer tank, an electromagnetic pulse valve, and a PLC controller. By dynamically linking the sludge discharge trigger with the influent load, it achieves intelligent feedback where the greater the disturbance, the more active the sludge discharge. When the influent flow rate instantaneously increases beyond a set threshold or the sludge level reaches a set height, the PLC controller triggers the electromagnetic pulse valve to open and close at a frequency of 3-5 times per second, converting the stable negative pressure into a pulsed negative pressure. The negative pressure suction causes the root of the flexible turbulence unit to contract centripetally, briefly opening the barrier above the sludge collection trough to form a funnel-shaped guiding channel. High-concentration sludge is rapidly sucked into the pipeline under the dual action of negative pressure and gravity. After sludge discharge, the flexible unit relies on its own elasticity to return to its original shape and re-cover the sludge collection trough. Compared to the conventional approach in existing technologies where negative pressure is only used for pipeline transportation and is independent of the water inlet conditions, the induced sludge discharge component of this invention increases the sludge concentration and reduces the sludge discharge water consumption. Moreover, the sludge discharge process does not disturb the flow state in the pool. At the same time, the oscillation effect of pulse negative pressure effectively prevents pipeline blockage, significantly improving the reliability and intelligence level of system operation. Attached Figure Description

[0024] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0025] Figure 1 This is a three-dimensional schematic diagram of the overall structure of a power plant water pollution cascade treatment device that achieves near-zero emissions according to the present invention;

[0026] Figure 2 This is a schematic diagram of the main structure of the cascade treatment pool of a power plant water pollution cascade treatment device that achieves near-zero emissions according to the present invention;

[0027] Figure 3 This is a schematic diagram of the influent conversion component structure of a power plant water pollution cascade treatment device that achieves near-zero emissions according to the present invention;

[0028] Figure 4 This invention relates to a cascade treatment device for water pollution in power plants that achieves near-zero emissions. Figure 3 A schematic diagram of the enlarged structure at point A in the middle;

[0029] Figure 5 This is a top view schematic diagram of the overall structure of a power plant water pollution cascade treatment device that achieves near-zero emissions according to the present invention;

[0030] Figure 6 This is a schematic diagram of the interface stabilization component structure of a power plant water pollution cascade treatment device that achieves near-zero emissions according to the present invention.

[0031] Figure 7 This is a schematic diagram of the flexible turbulence unit structure of a power plant water pollution cascade treatment device that achieves near-zero emissions according to the present invention;

[0032] Figure 8 This is a schematic diagram of the induced sludge discharge component structure of a power plant water pollution cascade treatment device that achieves near-zero emissions according to the present invention;

[0033] Figure 9 This is a schematic diagram of the negative pressure generating unit structure of a power plant water pollution cascade treatment device that achieves near-zero emissions, according to the present invention.

[0034] In the diagram: 100, main body of the cascade treatment tank; 110, inlet pipe; 120, inlet flow meter; 130, enclosure; 140, support plate; 200, inlet conversion component; 210, multi-layer variable aperture curved energy dissipation cover; 211, inner cover; 212, middle cover; 213, outer cover; 214, variable diameter through hole; 215, vertical flow stabilization joint; 300, interface stabilization component; 310, flexible flow disturbance unit; 311, root anchoring section; 31 2. Middle buffer section; 313. Top flexible section; 315. Sludge guide longitudinal channel; 316. Annular disc; 400. Sludge induction discharge assembly; 410. Sludge collection trough; 420. Negative pressure sludge discharge pipeline; 421. Filter screen; 430. Negative pressure generating unit; 431. Vacuum pump; 432. Vacuum buffer tank; 433. Electromagnetic pulse valve; 434. PLC controller; 435. Vacuum safety valve; 436. Sludge discharge valve; 442. Sludge level gauge. Detailed Implementation

[0035] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0036] Please see Figures 1-3 As shown, a cascade treatment device for water pollution in power plants that achieves near-zero emissions includes:

[0037] The main body 100 of the cascade treatment pool is fixedly connected to a protective fence 130 on its top;

[0038] The inlet conversion component 200 is installed in the inlet area of ​​the main body 100 of the cascade treatment tank. The inlet conversion component 200 includes a multi-layer variable aperture curved energy dissipation hood 210, which is used to convert the high-speed water flow input from the inlet pipe 110 into a low-speed rotating flow state and form a dynamic water curtain in the inlet area to suppress turbulent diffusion.

[0039] Interface stabilization component 300 is arranged in the mud-water interface layer of the main body 100 of the cascade treatment tank. Interface stabilization component 300 includes multiple flexible turbulence units 310, which are used to dissipate the residual water kinetic energy transferred to the sludge layer and guide the settled sludge to slide down its surface.

[0040] The induced sludge discharge component 400 is located outside the main body 100 of the cascade treatment tank and is spatially adjacent to the interface stabilization component 300. The induced sludge discharge component 400 includes a sludge collection tank 410, a negative pressure sludge discharge pipeline 420 and a negative pressure generating unit 430, which is used to generate negative pressure during sludge discharge and, with the cooperation of the flexible turbulence unit 310, discharge the sludge accumulated at the bottom of the tank outside the tank.

[0041] The inlet area of ​​the cascade treatment tank body 100 is provided with an inlet pipe 110, and an inlet flow meter 120 is fixedly connected to the inlet pipe 110. The inlet flow meter 120 is used to monitor the inlet water load of the cascade treatment tank body 100. A support plate 140 for positioning the vacuum pump 431, the vacuum buffer tank 432, and the PLC controller 434 is fixedly connected to one side of the cascade treatment tank body 100.

[0042] like Figure 3 and Figure 4 As shown, the multi-layer variable aperture curved surface energy dissipation cover 210 includes an inner cover 211, a middle cover 212 and an outer cover 213 nested from the inside to the outside. The inner cover 211 is a pointed cone shape, used to withstand the impact of incoming water and guide the water flow radially. The middle cover 212 is an inverted bowl shape, with variable diameter through holes 214 arranged in a spiral pattern on it. The diameter of the variable diameter through holes 214 gradually increases radially from the center to the edge, so that the water flow forms a rotational velocity gradient field when passing through. The outer cover 213 is cylindrical, with vertical flow stabilizing slits 215 on its cylindrical wall.

[0043] To address the issues of intense localized turbulence and large impact range caused by concentrated kinetic energy at the inlet of traditional sedimentation tanks, the following design is implemented: When the wastewater from the power plant enters the main body 100 of the cascade treatment tank via the inlet pipe 110, the wastewater first flows through the inlet flow meter 120 installed on the inlet pipe 110. This flow meter 120 monitors the inlet flow rate in real time and transmits the flow signal to the PLC controller 434, providing a data basis for subsequent linkage control. Subsequently, the high-speed water flow enters the inlet conversion component 200, specifically the multi-layered variable-aperture curved energy dissipation hood 210. When the high-speed water flow impacts the pointed conical surface of the inner hood 211, this geometry converts the vertically downward kinetic energy of the inlet water into radially diffused flow potential energy, preventing the inlet water from directly impacting the already settled sludge layer at the bottom of the tank, thus avoiding sludge re-suspension. The radially diffused water flow then enters the annular interlayer space between the inner cover 211 and the middle cover 212, and, driven by pressure, passes through multiple spirally arranged variable-diameter through-holes 214 on the middle cover 212. The diameter of the variable-diameter through-holes 214 increases radially from the center to the edge (e.g., the diameter is 8 mm in the central region and gradually increases to 20 mm in the edge region), arranged in a spiral. This specific structure causes the water flow to generate differentiated flow velocities when passing through the orifices of different diameters, with a relatively high flow velocity in the central region and a relatively low flow velocity in the edge region, thereby creating a rotational velocity gradient field inside the energy dissipation cover, where the velocity is fast in the center and slow at the edge. This velocity gradient field induces the water flow to form a slowly rotating vortex motion, generating a dynamically rotating water curtain in the inlet area. This water curtain confines the main kinetic energy of the inlet water to the central region of the energy dissipation cover, effectively suppressing the outward diffusion of high-speed turbulence into the main water body of the sedimentation zone. Finally, the water, after being decelerated by rotation, overflows evenly through the vertical flow stabilizing slits 215 on the outer casing 213, entering the main body 100 of the cascade treatment tank in a nearly undisturbed, low-velocity laminar flow. The influent conversion component 200 completes the process of efficiently dissipating the kinetic energy of the high-speed influent and converting it into a stable flow state conducive to sedimentation. Compared with the fixed perforated baffles or simple guide tubes commonly used in the prior art (which can only passively reduce the flow velocity through physical obstruction and cannot actively control the flow field distribution), the multi-layer variable aperture curved surface energy dissipation cover 210 of the present invention achieves active conversion and spatial redistribution of the kinetic energy of the influent by constructing a velocity gradient field, changing the flow field in the influent zone from an impact type to a rotational diffusion type, fundamentally eliminating the direct disturbance of the influent to the main water body in the sedimentation zone, and creating the preconditions for subsequent efficient sedimentation.

[0044] like Figure 5 and Figure 6 and Figure 7As shown, the flexible turbulence unit 310 is a graded density flexible turbulence unit, arranged in an array along the direction perpendicular to the water flow. The flexible turbulence unit 310 includes a root anchoring section 311, a middle buffer section 312, and a top flexible section 313 along its axial direction, and the three sections have different hardness gradients. The hardness of the root anchoring section 311 is greater than that of the middle buffer section 312, and the hardness of the middle buffer section 312 is greater than that of the top flexible section 313. This is used to form stable support at the bottom and dissipate water flow energy through flexible oscillation at the top. A stainless steel counterweight core rod is pre-embedded inside the root anchoring section 311. The surfaces of the root anchoring section 311, the middle buffer section 312, and the top flexible section 313 are provided with sludge guiding grooves 315 for guiding sludge to slide down. The bottom of the root anchoring section 311 is provided with an annular disc 316 for fixing to the main body 100 of the cascade treatment tank.

[0045] To address the problem of unstable mud-water interface control and sludge resuspension caused by slight disturbances in existing sedimentation tanks: Specifically, after pretreatment by the influent conversion component 200, a low-velocity water flow enters the sedimentation zone, where suspended particles begin to settle to the bottom under gravity. At this point, the interface stabilization component 300, arranged in the mud-water interface layer, plays a crucial role. This component consists of multiple flexible flow-disrupting units 310 arranged in an array (preferably in a staggered, quincunx pattern). Each flexible flow-disrupting unit 310 has three different hardness levels along the axial direction: the root anchoring section 311 has the highest hardness, and its interior is pre-embedded with a stainless steel counterweight core rod, which is fixedly connected to the bottom of the cascade treatment tank body 100 via a bottom ring plate 316, forming a stable support; the middle buffer section 312 has moderate hardness and elastic bending capability; and the top flexible section 313 has the lowest hardness and extremely high flexibility. When the residual turbulent kinetic energy of the water flow (possibly caused by temperature difference convection or weak inflow fluctuations) is transferred to the mud-water interface, it first touches the top flexible section 313. This section converts the turbulent kinetic energy into mechanical heat dissipation through high-frequency, small-amplitude flexible oscillations, reducing the kinetic energy of the water to less than one-tenth of its original strength. If the kinetic energy is stronger, the middle buffer section 312 further absorbs energy through elastic bending, while the root anchoring section 311 remains upright, ensuring the stability of the integrated unit structure. This dynamic response mechanism constructs a flexible buffer layer with a thickness of approximately 200 to 300 mm at the mud-water interface. This buffer layer can adaptively adjust the oscillation amplitude according to the inflow intensity, thereby completely isolating any residual kinetic energy from directly scouring the already settled sludge layer. At the same time, the weak pumping effect generated by the sludge guiding longitudinal channels 315 (spiral-shaped) on the unit surface during the unit's oscillation guides the sludge particles that have settled to the unit surface to slide down the channel towards the root, eventually flowing into the sludge collection tank 410, effectively preventing sludge accumulation on the surface of the flexible unit. Compared to existing technologies that use rigid scrapers to mechanically scrape mud (which may disturb the mud layer during operation) or simple static settling (which has no resistance to disturbance), this graded density flexible turbulence unit 310 achieves flexible protection of the mud-water interface. The difference is that existing technologies regard the mud surface as a passive bearing surface, while this solution transforms the mud surface into a dynamic interface with active energy dissipation capabilities, and achieves a balance between protection strength and response speed through material gradient design.

[0046] like Figure 2 , Figure 5 and Figure 8 and Figure 9As shown, the sludge collection tank 410 is a V-shaped trough arranged along the width of the tank. The root of the flexible turbulence unit 310 is inclined towards the centerline of the sludge collection tank 410 at an angle of 10-25 degrees. A filter screen 421 is provided at the inlet of the negative pressure sludge discharge pipe 420. The negative pressure generating unit 430 includes: a vacuum pump 431 for generating a negative pressure source; a vacuum buffer tank 432, which is connected to the suction port of the vacuum pump 431 through a pipe for storing negative pressure energy and stabilizing negative pressure fluctuations; and an electromagnetic pulse valve 433, which is connected to... A PLC controller 434 is connected between the vacuum buffer tank 432 and the negative pressure sludge discharge pipeline 420 to convert stable negative pressure into pulse negative pressure. It is electrically connected to the inlet flow meter 120, the sludge level gauge 442 and the electromagnetic pulse valve 433 to control the opening and closing sequence of the electromagnetic pulse valve 433 according to the inlet water load or sludge level signal. The vacuum buffer tank 432 is equipped with a sludge discharge valve 436 at the bottom to periodically discharge the sludge deposited in the tank. The vacuum buffer tank 432 is equipped with a vacuum safety valve 435 at the top to prevent the negative pressure from exceeding the set value.

[0047] To address the technical problems of secondary disturbance and low sludge concentration during traditional sludge removal methods (such as gravity sludge removal and mechanical scraping), specifically, the sludge sliding to the bottom of the pool is enriched into the sludge collection trough 410 under the action of gravity along the slope of the pool bottom. The sludge collection trough 410 is a V-shaped trough arranged along the width of the pool. The root of the flexible turbulence unit 310 is inclined at 10-25 degrees towards the centerline of the sludge collection trough 410. This inclination design shortens the sludge sliding path and creates geometric guidance conditions for subsequent negative pressure sludge removal. When the influent flow meter 120 detects an instantaneous flow increase exceeding a preset threshold (e.g., 20 percent, lasting for 3 minutes) or the sludge level gauge 442 detects that the sludge level in the sludge collection trough 410 has reached a set height, the PLC controller 434 activates the induced sludge removal component 400. Its working process is as follows: First, the vacuum pump 431 starts and continuously draws air from the vacuum buffer tank 432 to establish a stable negative pressure inside the tank. Subsequently, the PLC controller 434 triggers the electromagnetic pulse valve 433 to open and close at a high speed of 3-5 times per second according to preset logic. When the electromagnetic pulse valve 433 opens, the negative pressure energy stored in the vacuum buffer tank 432 is instantly released through the negative pressure sludge discharge pipe 420 to the inlet of the negative pressure sludge discharge pipe 420 in the sludge collection tank 410; when the valve closes, the negative pressure is interrupted. This high-frequency opening and closing process converts the stable negative pressure into pulsed negative pressure. This pulsed negative pressure acts on the inlet of the negative pressure sludge discharge pipe 420, generating a local strong negative pressure zone. Because the root of the flexible turbulence unit 310 is inclined towards the center of the sludge collection tank 410, the suction force generated by the negative pressure causes a slight centripetal contraction at the root of the unit. This contraction action temporarily opens the flexible barrier that originally covered the sludge collection tank 410, forming a funnel-shaped guide channel. At this point, the high-concentration sludge accumulated in the sludge collection tank 410 is rapidly drawn into the suction branch pipe under the combined action of negative pressure and gravity, and enters the vacuum buffer tank 432 through the negative pressure sludge discharge pipeline 420. After entering the buffer tank, the heavier sludge particles settle at the bottom of the tank, while the gas is discharged through the vacuum pump 431. The settled sludge is periodically discharged into subsequent sludge thickening or dewatering equipment through the bottom sludge discharge valve 436. After the sludge discharge is completed, the electromagnetic pulse valve 433 closes, the negative pressure disappears, and the base of the flexible turbulence unit 310 returns to its original shape due to its own elasticity, re-covering the sludge collection tank 410 to prevent disturbance from the upper water body. The entire sludge discharge process lasts 3-5 seconds, and the sludge discharge volume is precisely controllable. Compared to existing technologies where negative pressure is only used for pipeline transportation (such as negative pressure self-priming sludge discharge devices, which only involve external pipelines and are unrelated to the flow state inside the pool) or where sludge discharge and water intake conditions are independent of each other, the induced sludge discharge component 400 in this solution achieves a triple function: First, it dynamically links sludge discharge triggering with water intake load, realizing intelligent feedback that the greater the disturbance, the more active the sludge discharge; Second, by utilizing the centripetal contraction of the flexible turbulence unit 310 under negative pressure, it achieves a life-like behavior of clearing the channel during sludge discharge and automatically closing it after sludge discharge, completely eliminating secondary disturbances in the sludge discharge process; Third, the oscillation effect of pulsed negative pressure effectively prevents pipeline blockage and improves system reliability.

[0048] When the PLC controller 434 detects that the influent flow rate increases instantaneously beyond the set threshold, it triggers the electromagnetic pulse valve 433 to open at a frequency of 3-5 times per second to form a negative pressure pulse for sludge discharge. When the sludge level in the sludge collection tank 410 exceeds the set height, it triggers the electromagnetic pulse valve 433 to open for sludge discharge. The PLC controller 434 is connected to the central control room through a communication interface to upload operating data and receive remote commands.

[0049] To address the disconnect between sludge discharge and influent conditions in existing sludge tank control systems, the following two sets of logic are implemented: First, a load-linked logic continuously monitors the influent flow rate change rate. When an instantaneous flow rate increase exceeds 20% and lasts for more than 3 seconds, it is determined to be an increased influent disturbance, immediately triggering the sludge discharge procedure. At this time, the PLC controller 434 outputs a high-frequency switching signal (3-5 times per second) to control the opening and closing of the electromagnetic pulse valve 433 for 3-5 seconds, creating a negative pressure pulse for sludge discharge. The principle is that a sudden increase in influent flow rate indicates an increased disturbance source, and the sludge-water interface faces a greater risk of impact. Discharging some sludge in advance can lower the sludge level and reduce the possibility of resuspension. Second, a sludge level control logic continuously monitors the sludge level in the sludge collection tank 410. When the sludge level exceeds a set threshold (e.g., 80% of the tank depth), the sludge discharge procedure is triggered. At this time, the PLC controller 434 can be adjusted to a lower frequency (e.g., 1-2 times per second) pulse or continuous negative pressure sludge discharge to ensure timely sludge discharge without excessive concentration and caking. The two sets of logic complement each other, ensuring precise sludge removal under any operating condition. Simultaneously, the PLC controller 434 connects to the central control room via an Ethernet communication interface, uploading operational data in real time (including influent flow rate, sludge level, number of sludge removals, equipment status, etc.) and receiving remote commands, enabling unattended automated operation. Compared to conventional methods in existing technologies that employ timed sludge removal (independent of water quality conditions) or simple sludge level control (with delayed response), this solution's PLC controller 434, through its dual logic of load linkage and sludge level control, achieves proactive response and precise control to changes in operating conditions, significantly improving the level of intelligence and operational stability.

[0050] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed invention.

Claims

1. A cascade treatment device for water pollution in power plants that achieves near-zero emissions, characterized in that, include: The main body (100) of the cascade treatment pool is fixedly connected to a protective fence (130) on its top. The inlet conversion component (200) is installed in the inlet area of ​​the main body (100) of the cascade treatment tank. The inlet conversion component (200) includes a multi-layer variable aperture curved energy dissipation hood (210) for converting the high-speed water flow input from the inlet pipe (110) into a low-speed rotating flow state and forming a dynamic water curtain in the inlet area to suppress turbulent diffusion. An interface stabilization component (300) is arranged in the mud-water interface layer of the main body (100) of the cascade treatment tank. The interface stabilization component (300) includes a plurality of flexible turbulence units (310) for dissipating the residual water kinetic energy transferred to the sludge layer and guiding the settled sludge to slide down its surface. The induced sludge discharge assembly (400) is located outside the main body (100) of the cascade treatment tank and is spatially adjacent to the interface stabilization assembly (300). The induced sludge discharge assembly (400) includes a sludge collection tank (410), a negative pressure sludge discharge pipeline (420), and a negative pressure generating unit (430), which is used to generate negative pressure during sludge discharge and, in conjunction with the flexible turbulence unit (310), discharge the sludge accumulated at the bottom of the tank outside the tank.

2. The power plant water pollution cascade treatment device for achieving near-zero emissions according to claim 1, characterized in that: The multi-layer variable aperture curved surface energy dissipation cover (210) includes an inner cover (211), a middle cover (212), and an outer cover (213) nested from the inside to the outside. The inner cover (211) is a pointed cone shape, used to withstand the impact of incoming water and guide the water flow radially. The middle cover (212) is an inverted bowl shape, with variable diameter through holes (214) arranged in a spiral pattern on it. The diameter of the variable diameter through holes (214) gradually increases radially from the center to the edge, so that the water flow forms a rotational velocity gradient field when passing through. The outer cover (213) is cylindrical, with vertical flow stabilizing slits (215) on its cylindrical wall.

3. The power plant water pollution cascade treatment device for achieving near-zero emissions according to claim 1, characterized in that: The flexible flow disturbance unit (310) is a graded density flexible flow disturbance unit, arranged in an array along the direction perpendicular to the water flow. The flexible flow disturbance unit (310) includes a root anchoring section (311), a middle buffer section (312), and a top flexible section (313) along its axial direction. The three sections have different hardness gradients. The hardness of the root anchoring section (311) is greater than that of the middle buffer section (312), and the hardness of the middle buffer section (312) is greater than that of the top flexible section (313). It is used to form a stable support at the bottom and dissipate the water flow energy through flexible swing at the top.

4. The power plant water pollution cascade treatment device for achieving near-zero emissions according to claim 3, characterized in that: The root anchoring section (311) is pre-embedded with a stainless steel counterweight core rod. The surfaces of the root anchoring section (311), the middle buffer section (312) and the top flexible section (313) are provided with sludge guiding grooves (315) for guiding sludge to slide down. The bottom of the root anchoring section (311) is provided with a ring plate (316) for fixing to the main body (100) of the cascade treatment tank.

5. The power plant water pollution cascade treatment device for achieving near-zero emissions according to claim 4, characterized in that: The sludge collection trough (410) is a V-shaped trough arranged along the width of the pool. The root of the flexible turbulence unit (310) is inclined towards the center line of the sludge collection trough (410) with an inclination angle of 10 degrees to 25 degrees. A filter screen (421) is provided at the inlet of the negative pressure sludge discharge pipeline (420).

6. The power plant water pollution cascade treatment device for achieving near-zero emissions according to claim 5, characterized in that: The negative pressure generating unit (430) includes: a vacuum pump (431) for generating a negative pressure source; a vacuum buffer tank (432) connected to the suction port of the vacuum pump (431) via a pipeline for storing negative pressure energy and stabilizing negative pressure fluctuations; an electromagnetic pulse valve (433) connected between the vacuum buffer tank (432) and the negative pressure sludge discharge pipeline (420) for converting stable negative pressure into pulse negative pressure; and a PLC controller (434) electrically connected to the inlet flow meter (120), the sludge level gauge (442), and the electromagnetic pulse valve (433) for controlling the opening and closing sequence of the electromagnetic pulse valve (433) according to the inlet water load or sludge level signal.

7. The power plant water pollution cascade treatment device for achieving near-zero emissions according to claim 6, characterized in that: The vacuum buffer tank (432) is equipped with a sludge discharge valve (436) at the bottom for periodically discharging the sludge deposited in the tank. The vacuum buffer tank (432) is equipped with a vacuum safety valve (435) at the top to prevent the negative pressure from exceeding the set value.

8. The power plant water pollution cascade treatment device for achieving near-zero emissions according to claim 6, characterized in that: When the PLC controller (434) detects that the influent flow rate increases instantaneously beyond the set threshold, it triggers the electromagnetic pulse valve (433) to open at a frequency of 3-5 times per second to form a negative pressure pulse for sludge discharge. When the sludge level in the sludge collection tank (410) exceeds the set height, it triggers the electromagnetic pulse valve (433) to open for sludge discharge. The PLC controller (434) is connected to the central control room through a communication interface to upload operating data and receive remote commands.

9. The power plant water pollution cascade treatment device for achieving near-zero emissions according to claim 1, characterized in that: The inlet area of ​​the cascade treatment tank body (100) is provided with an inlet pipe (110), and an inlet flow meter (120) is fixedly connected to the inlet pipe (110). The inlet flow meter 120 is used to monitor the inlet load of the cascade treatment tank body (100). A support plate (140) for positioning the vacuum pump (431), the vacuum buffer tank (432), and the PLC controller (434) is fixedly connected to one side of the cascade treatment tank body (100).

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