Long distance wastewater discharge system for offshore nuclear power plant

Abstract

The application belongs to the technical field of nuclear power plant wastewater discharge, and particularly relates to a long-distance wastewater discharge system for a near-sea nuclear power plant; the system comprises a plant-area drainage module, a land-area drainage module and a sea-area drainage module; the plant-area drainage module transports wastewater to the land-area drainage module through a land-area drainage pipeline; the land-area drainage pipeline is designed as a double-sleeve pipeline; the plant-area drainage module comprises a wastewater discharge device and a fresh water conveying device; the wastewater discharge device transports wastewater to the land-area drainage module through an inner sleeve of the land-area drainage pipeline; the fresh water conveying device conveys fresh water between the inner sleeve and an outer sleeve of the land-area drainage pipeline, so that the inner sleeve and the outer sleeve of the land-area drainage pipeline are filled with fresh water; the land-area drainage module transports wastewater to the sea-area drainage module through a sea-area drainage pipeline; and the sea-area drainage module discharges the wastewater into the sea. The double-sleeve design of the land-area drainage pipeline realizes reliable physical isolation of the wastewater from the environment soil.

Description

Technical Field

[0001] This application belongs to the field of nuclear power plant wastewater discharge technology, specifically relating to a long-distance wastewater discharge system for offshore nuclear power plants. Background Technology

[0002] Offshore nuclear power plant sites are typically tens of kilometers from the coast, and freshwater resources around these plants are limited, necessitating seawater cooling for the plant's process systems. Seawater cooling methods include direct-flow cooling and cooling tower cooling. Due to the distance from the sea, direct-flow cooling is expensive to build and operate; therefore, cooling tower cooling is more commonly used. The effluent from the cooling tower is pumped to the conventional island turbine condenser and auxiliary equipment cooling system, and the heated water is then returned to the cooling tower via pressurized pipelines for further cooling. This repeated seawater circulation dissipates heat into the air, but the circulating seawater also continuously concentrates, increasing salinity and potentially damaging equipment and pipelines. Therefore, concentrated brine needs to be periodically discharged. Additionally, if the nuclear power plant uses seawater desalination, concentrated brine will also be generated. Wastewater from the nuclear island, after treatment, also needs to be discharged. Concentrated brine and wastewater (hereinafter collectively referred to as wastewater) must be discharged together into a special utilization area in the sea.

[0003] The most economical way to discharge wastewater is through direct burial pipelines. However, since these pipelines must traverse land areas (including farmland), any damage to the pipe walls can lead to soil salinization and damage to local agricultural resources. Traditional methods include increasing fluid monitoring, comparing changes in inlet and outlet flow rates to assess leaks, and improving construction quality. However, these methods cannot monitor concentrated brine leaks in real time or provide timely remediation. Due to the large wastewater flow rate, by the time a flow rate change is detected, the wastewater has already contaminated the soil near the leak point in the buried pipe, causing damage to the surrounding soil and increasing the risks associated with compensation and public opinion. Summary of the Invention

[0004] The purpose of this application is to provide a long-distance wastewater discharge system for offshore nuclear power plants, which solves the problem that dozens of existing systems cannot promptly remedy wastewater leaks and cause damage to soil and the ecological environment.

[0005] The technical solution to achieve the purpose of this application is as follows:

[0006] This application provides a long-distance wastewater discharge system for offshore nuclear power plants, the system comprising: a plant area drainage module, a land area drainage module, and a marine area drainage module;

[0007] The plant area drainage module delivers wastewater to the land area drainage module through the land area drainage pipeline;

[0008] The land-based drainage pipeline is a double-sleeve design;

[0009] The plant drainage module includes a wastewater discharge device and a freshwater transport device; the wastewater discharge device transports wastewater to the land drainage module through the inner sleeve of the land drainage pipeline; the freshwater transport device transports freshwater between the inner sleeve and the outer sleeve of the land drainage pipeline, so that the space between the inner sleeve and the outer sleeve of the land drainage pipeline is filled with freshwater.

[0010] The land-based drainage module delivers the wastewater to the marine drainage module through the marine drainage pipeline;

[0011] The marine drainage module is used to discharge the wastewater into the ocean.

[0012] Optionally, at least one monitoring point is installed on the land drainage pipeline to monitor the water quality of the freshwater between the inner and outer sleeves.

[0013] Optional,

[0014] There are at least two land-based drainage pipelines, with one pipeline serving as a backup.

[0015] Optionally, the inner sleeve of the land drainage pipe is made of fiberglass, and the outer wall of the inner sleeve is coated with anti-rust paint; the outer sleeve of the land drainage pipe is made of concrete; both the inner sleeve and the outer sleeve are provided with inspection holes for pipe maintenance.

[0016] Optionally, there are multiple monitoring points, with one monitoring point set at a preset distance along the land drainage pipeline.

[0017] Optionally, the land drainage module includes: an elevated drainage tower and a freshwater drainage pump;

[0018] The elevated drainage tower is located at the junction of the sea and land;

[0019] The inner sleeve of the land drainage pipeline is configured with an inverted U-shaped structure on the high-level drainage tower and is connected to the marine drainage pipeline.

[0020] Freshwater is transported between the inner and outer sleeves of the land drainage pipeline to the elevated drainage tower and then discharged into the ocean via the freshwater drainage pump.

[0021] Optionally, the land drainage module further includes: a vacuum pump;

[0022] The vacuum pump is used to draw non-condensable gas from the inverted U-shaped inner sleeve in the high-level drainage tower, while simultaneously creating a certain vacuum level.

[0023] Optionally, the elevated drainage tower is equipped with a monitoring instrument for monitoring the salinity of the freshwater inside.

[0024] Optionally, the marine drainage pipe is equipped with at least one drainage cap as an outlet for the wastewater to be discharged into the sea.

[0025] Optionally, there are at least two drainage pipes in the sea area.

[0026] Optionally, the marine drainage module includes: a discharge outlet management fence;

[0027] The discharge outlet management fence is used to prevent the drainage cap from being bumped.

[0028] The beneficial technical effects of this application are as follows:

[0029] (1) This application provides a long-distance wastewater discharge system for offshore nuclear power plants. The double-pipe design of the land drainage pipeline can realize that the wastewater flows in the inner pipe and the space between the inner and outer pipes is filled with fresh water. Even if the wastewater in the inner pipe leaks, it can only leak into the fresh water between the inner and outer pipes, thus realizing reliable physical isolation between the wastewater and the environmental soil. It also greatly reduces the difficulty of monitoring the leakage of the wastewater pipeline and can achieve "zero leakage" to the external environment during the wastewater discharge process, avoiding damage to the soil environment by the wastewater. The ecological and social benefits are significant and it is the first of its kind in China.

[0030] (2) This application provides a long-distance wastewater discharge system for offshore nuclear power plants. By setting up monitoring points and salinity monitors in the land drainage pipeline and the high-level drainage tower, the salinity of freshwater in the land drainage pipeline and the high-level drainage tower can be monitored in real time. Even if a small amount of wastewater leaks in the land drainage pipeline, it can be detected in time.

[0031] (3) This application provides a long-distance wastewater discharge system for offshore nuclear power plants. By setting up at least two land-based drainage pipelines, it is possible to switch pipelines in a timely manner in case of wastewater leakage without affecting the normal operation of the system and without affecting the operation of the unit. It also facilitates the isolation of faulty pipelines by pumping out water and allows personnel to enter for timely repairs. Attached Figure Description

[0032] Figure 1 A schematic diagram of a long-distance wastewater discharge system for an offshore nuclear power plant provided in this application embodiment;

[0033] Figure 2 A cross-sectional view of a land-based drainage pipeline in a long-distance wastewater discharge system for an offshore nuclear power plant, provided as an embodiment of this application;

[0034] Figure 3 This is a schematic diagram of another long-distance wastewater discharge system for offshore nuclear power plants provided in this application embodiment.

[0035] In the picture:

[0036] 1-Plant drainage module; 11-Wastewater discharge device; 12-Freshwater conveying device; 13-Wastewater pump;

[0037] 14-Suction tank; 15-Freshwater tank; 16-Ring network; 17-Freshwater makeup pump;

[0038] 2-Land drainage module; 21-Elevated drainage tower; 22-Freshwater drainage pump; 23-Vacuum pump;

[0039] 3-Marine drainage module; 31-Discharge outlet management fence;

[0040] 4-Land drainage pipeline; 41-Inner sleeve; 42-Outer sleeve; 43-Monitoring point;

[0041] 5-Sea area drainage pipe; 51-Drainage cap. Detailed Implementation

[0042] To enable those skilled in the art to better understand this application, the technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the embodiments described below are only a part of the embodiments of this application, and not all of them. Based on the embodiments described in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0043] See Figure 1 The figure is a schematic diagram of a long-distance wastewater discharge system for an offshore nuclear power plant provided in an embodiment of this application.

[0044] This application provides a long-distance wastewater discharge system for an offshore nuclear power plant, comprising: a plant area drainage module 1, a land area drainage module 2, and a marine area drainage module 3.

[0045] The plant area drainage module 1 delivers wastewater to the land area drainage module 2 through the land area drainage pipe 4;

[0046] like Figure 2 As shown, land drainage pipe 4 is a double-casing design;

[0047] The plant drainage module 1 includes a wastewater discharge device 11 and a freshwater conveying device 12; the wastewater discharge device 11 conveys wastewater to the land drainage module 2 through the inner sleeve 41 of the land drainage pipe 4; the freshwater conveying device 12 conveys freshwater between the inner sleeve 41 and the outer sleeve 42 of the land drainage pipe 4, so that the space between the inner sleeve 41 and the outer sleeve 42 of the land drainage pipe 4 is filled with freshwater.

[0048] The land-based drainage module 2 delivers wastewater to the marine drainage module 3 through the marine drainage pipeline 5;

[0049] Marine drainage module 3 is used to discharge wastewater into the ocean.

[0050] Understandably, when a wastewater leak occurs, the wastewater inside the inner sleeve 41 will leak into the freshwater between the inner sleeve 41 and the outer sleeve 42, rather than leaking directly into the soil near the buried pipe, thus avoiding damage to the surrounding soil and ecological environment.

[0051] In some possible implementations of this application, to detect whether wastewater leakage has occurred, at least one monitoring point 43 is installed on the land drainage pipe 4 to monitor the water quality of the freshwater between the inner sleeve 41 and the outer sleeve 42. When wastewater leakage occurs, the salinity of the freshwater between the inner sleeve 41 and the outer sleeve 42 will increase, generating a salinity alarm. By monitoring the water quality of this freshwater, real-time monitoring of the wastewater leakage can be achieved.

[0052] In one example, there are multiple monitoring points 43, with one monitoring point 43 set at preset intervals along the land-based drainage pipeline 4. This way, when a wastewater leak occurs, the leak area can be quickly located and the investigation scope narrowed by using salinity alarms and data from each monitoring point. As an example, one monitoring point 43 is set every 1 kilometer along the land-based discharge pipeline 4 to monitor freshwater salinity. When the inner sleeve 41 leaks, the monitoring points 43 on either side of the leak point can quickly detect an increase in freshwater salinity.

[0053] In some possible implementations of the embodiments of this application, there are at least two land drainage pipes 4, with one land drainage pipe 4 serving as a backup.

[0054] Understandably, once the salinity of freshwater in one of the operating land drainage pipes 4 is detected to exceed the standard, the land drainage pipe 4 can be shut down immediately and switched to the backup land drainage pipe 4. This allows for timely pipe switching in case of leakage, without affecting the normal operation of the equipment or the unit, and facilitates the isolation of the faulty pipeline by pumping out water and allowing personnel to enter for timely repairs.

[0055] In some possible implementations of the embodiments of this application, the inner sleeve 41 of the land drainage pipe 4 is made of fiberglass, and the outer wall of the inner sleeve 41 is coated with anti-rust paint; the outer sleeve 42 of the land drainage pipe 4 is made of concrete; inspection holes are provided on the inner sleeve 41 and the outer sleeve 42 for pipe maintenance.

[0056] In some possible implementations of the embodiments of this application, such as Figure 3 As shown, the land drainage module 2 includes: an elevated drainage tower 21 and a freshwater drainage pump 22;

[0057] The elevated drainage tower 21 is located at the junction of the sea and land;

[0058] The inner sleeve 41 of the land drainage pipeline 4 is set in an inverted U-shaped structure inside the high-level drainage tower 21 and is connected to the marine drainage pipeline 5.

[0059] Understandably, the inner sleeve 41 is designed with an inverted U-shaped structure inside the high-level drainage tower 21 to prevent seawater from flowing back in at the highest design tide level and to ensure that wastewater flows by gravity to the drainage outlet.

[0060] Freshwater is transported between the inner sleeve 41 and the outer sleeve 42 of the land drainage pipeline 4 to the high-level drainage tower 21 and discharged into the ocean through the freshwater drainage pump 22.

[0061] In some examples, the land drainage module 2 also includes: a vacuum pump 23;

[0062] Vacuum pump 23 is used to extract non-condensable gas from the inverted U-shaped inner sleeve 41 in the high-level drainage tower 21, and at the same time, to extract a certain value of vacuum to ensure that wastewater can reach the top of the inverted U-shaped inner sleeve 41, and to appropriately reduce the head of wastewater pump 13 in the plant drainage module 1.

[0063] The elevated drainage tower 21 is equipped with a monitoring instrument for monitoring the salinity of the freshwater inside it. Monitoring the salinity of the freshwater passing through the elevated drainage tower 21 can further ensure the reliability and accuracy of salinity monitoring.

[0064] In practical applications, data from monitoring points 43 and the high-level discharge tower 21 are transmitted to the control center of the freshwater drainage pumping station. The control center has a monitoring screen displaying the monitoring and alarm values ​​of each monitoring point 43. Based on the alarm values ​​of monitoring points 43, the leakage range of the land drainage pipeline 4 can be quickly determined, the approximate location of the leak can be judged, and then the leak point can be located through on-site inspection and timely remedial measures can be taken. Inspection wells are set at appropriate locations in the land drainage pipeline 4, and inspection holes are set on the pipe walls of the inner sleeve 41 and the outer sleeve 42. After the land drainage pipeline 4 is emptied and isolated, personnel can enter the pipe for maintenance.

[0065] In some possible implementations of the embodiments of this application, at least one drainage cap 51 is provided on the marine drainage pipe 5 as a discharge outlet for wastewater to be discharged into the sea.

[0066] In practical applications, the number of drainage caps 51 can be set according to the discharge flow requirements. The number and spacing of drainage caps 51 are determined by comprehensively considering requirements such as temperature rise, temperature rise area, and temperature rise area shape control in the drainage area. As an example, 3-5 drainage caps 51 are set at a certain interval at the end of the marine drainage pipeline 5. Drainage caps 51 can be equipped with drainage outlets for wastewater discharge into the sea. Isolation gates are installed at the drainage outlets of drainage caps 51 to ensure reliable isolation of the marine drainage pipeline 5 during maintenance.

[0067] It should also be noted that the elevation of the drainage cap 51 is set to ensure that it can be submerged by seawater at the design low tide level, and the drainage outlet of the drainage cap 51 is equipped with an isolation gate to ensure that the drainage pipe can be reliably isolated during maintenance.

[0068] In some cases, there are at least two marine drainage pipes 5, one as a backup, to prevent damage to the pipes from affecting the normal operation of the unit.

[0069] In practical applications, the marine drainage pipe 5 can be a single-layer pipe with an inner diameter of Dn2800 and a water flow velocity of approximately 2.48 m / s. The pipe material is fiberglass water supply pipe, and the pipe wall is coated with anti-rust paint. Wastewater can be uniformly discharged into a special utilization area in the sea through the marine drainage pipe 5.

[0070] In some possible implementations of the embodiments of this application, the marine drainage module 3 includes: a discharge outlet management fence 31;

[0071] The discharge outlet management fence 31 is used to prevent the drain cap 51 from being bumped.

[0072] Understandably, the discharge outlet management fence 31 also helps to prevent the risk of collisions between personnel and divers operating the drain cap 51 and external vessels. In some cases, warning lights are installed on the discharge outlet management fence 31 to remind vessels to avoid the area of ​​the drain cap 51 in advance.

[0073] In some possible implementations of the embodiments of this application, the wastewater discharge device 11 includes: a ring network 16, a wastewater pump 13, and at least one suction tank 14;

[0074] Water intake pool 14 is used to collect and store wastewater that needs to be discharged into the sea.

[0075] As an example, the wastewater may include concentrated seawater generated during the circulating cooling process, concentrated brine generated during the seawater desalination process, and qualified wastewater from the nuclear island treatment.

[0076] Wastewater pump 13 is used to transport wastewater from suction tank 14 to ring network 16 through pipeline. Ring network 16 is used to collect wastewater and transport it to land drainage module 2 through inner sleeve 41 of land drainage pipeline 4.

[0077] Freshwater delivery device 12 includes: freshwater tank 15 and freshwater replenishment pump 17;

[0078] Freshwater tank 15 is used to store freshwater. Freshwater replenishment pump 17 is used to draw freshwater from freshwater tank 15 and pump it into the space between the inner sleeve 41 and the outer sleeve 41 of the land discharge pipe 5.

[0079] The present application has been described in detail above with reference to the accompanying drawings and embodiments. However, the present application is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present application. All content not described in detail in this application can be derived from existing technology.

Claims

1. A long distance wastewater discharge system for an offshore nuclear power plant, characterized in that, The system comprises a plant area drainage module, a land area drainage module and a sea area drainage module; The plant area drainage module transports wastewater to the land area drainage module through a land area drainage pipeline; The land area drainage pipeline is designed as a double sleeve pipeline; The plant area drainage module comprises a wastewater discharge device and a fresh water delivery device; the wastewater discharge device transports the wastewater to the land area drainage module through an inner sleeve of the land area drainage pipeline; the fresh water delivery device delivers fresh water between the inner sleeve and an outer sleeve of the land area drainage pipeline so that the inner sleeve and the outer sleeve of the land area drainage pipeline are filled with fresh water; The land area drainage module transports the wastewater to the sea area drainage module through a sea area drainage pipeline; The land area drainage module comprises a high-level drainage tower and a fresh water drainage pump; The high-level drainage tower is arranged at a sea-land junction; The inner sleeve of the land area drainage pipeline is arranged in a reverse U-shaped structure in the high-level drainage tower and is connected with the sea area drainage pipeline to prevent seawater from flowing backward at the highest design tide level and to ensure that the wastewater flows to a drainage outlet by itself; Fresh water is delivered between the inner sleeve and the outer sleeve of the land area drainage pipeline into the high-level drainage tower and is discharged into the sea by the fresh water drainage pump; the sea area drainage module is used to discharge the wastewater into the sea; At least one monitoring point is arranged on the land area drainage pipeline to monitor the water quality of the fresh water between the inner sleeve and the outer sleeve.

2. The long-distance wastewater discharge system for offshore nuclear power plants according to claim 1, wherein The land area drainage pipeline has at least two pipelines, and the two pipelines are used alternatively.

3. The long distance wastewater discharge system for an offshore nuclear power plant according to claim 1, characterized by, The inner sleeve of the land area drainage pipeline is made of glass fiber reinforced plastic, and the outer wall of the inner sleeve is coated with anti-rust paint; the outer sleeve of the land area drainage pipeline is made of concrete; the inner sleeve and the outer sleeve are provided with maintenance holes for pipeline maintenance.

4. A long distance wastewater discharge system for an offshore nuclear power plant according to any of claims 2-3, characterized in that, There are multiple monitoring points, and one monitoring point is arranged on the land area drainage pipeline every interval of a preset distance.

5. The long distance wastewater discharge system for an offshore nuclear power plant according to claim 1, characterized by, The land area drainage module further comprises a vacuum pump; The vacuum pump is used to suck non-condensed gas in the reverse U-shaped inner sleeve of the high-level drainage tower and to extract a certain value of vacuum.

6. The long distance wastewater discharge system for an offshore nuclear power plant according to claim 1, characterized by, The high-level drainage tower is provided with a monitor for monitoring the salinity of the fresh water inside the tower.

7. The long distance wastewater discharge system for an offshore nuclear power plant according to claim 1, characterized by, At least one drainage cap is arranged on the sea area drainage pipeline as a discharge outlet for the wastewater to be discharged into the sea.

8. A long distance wastewater discharge system for an offshore nuclear power plant according to claim 7, characterized in that, The sea area drainage pipeline has at least two pipelines.

9. The long distance wastewater discharge system for an offshore nuclear power plant according to claim 7, characterized by, The sea area drainage module comprises a discharge outlet management fence; The discharge outlet management fence is used to prevent the drainage cap from being collided.

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