CN114519495A - Ocean pollutant motion trajectory prediction and coastal power plant water taking safety early warning method - Google Patents

Abstract

The invention discloses a method for predicting motion trail of marine pollutants and safely warning water intake of a coastal power plant, which comprises the following steps: (1) establishing a regional power flow mathematical model; (2) establishing a particle tracking model; (3) dividing the sea area around the engineering water intake door into a plurality of particle source release points by taking the engineering water intake door as a center; (4) calculating the motion path of the pollutants, and counting the flux and distribution condition of the pollutants entering the open channel; (5) making a probability cloud picture of pollutants entering an open channel; (6) marking the pollutants according to field synchronization; (7) and inputting the pollutant information into a particle mathematical model, predicting the subsequent motion track of the pollutant and calculating the time of the pollutant moving to a water intake, and giving an early warning to a coastal power plant operation unit. By adopting the technical scheme, early warning can be provided for cold source safety departments of the coastal power plants, the risk of unit shutdown caused by pollutant accumulation of the coastal power plants is reduced, and the operation efficiency of the coastal power plants is improved.

Description

Prediction of Marine Pollutant Trajectory and Early Warning Method for Water Intake Safety in Binhai Power Plant

technical field

The invention belongs to the technical field of coastal power plant security, and in particular relates to a method for predicting the movement trajectory of marine pollutants and a safety warning method for water intake in a coastal power plant.

Background technique

In recent years, incidents of marine organisms or foreign objects affecting the safety of water intake in Binhai Power Plant have occurred many times at home and abroad, and there is an increasing trend. Cold source safety has become an important factor affecting the safety of Binhai Power Plant. According to analysis by the World Association of Nuclear Operators (WANO), approximately 20% of such incidents have a direct impact on safety-related systems. In extreme cases such as massive accumulation of marine organisms and sudden influx of pollutants, accidents such as damage to the containment structure and shutdown of units have seriously affected the water intake safety of Binhai Power Plants.

Due to the wide variety of pollutants and limited by scientific forecasting methods, the main way to deal with pollutants is passive cleaning. On the net, and then by manual salvage. For the day-to-day operation period, regular maintenance can ensure the safe operation of the power plant. However, under extreme conditions, after a large amount of pollutants suddenly poured into the water intake door, due to the inability of manpower and material resources to meet the pollutant cleaning requirements in a short period of time, a large number of pollutants accumulated, resulting in damage to the structure of the pollution blocking net or serious blocking of the pollution blocking net, which affected the water intake. , thereby further causing the shutdown of the power plant and affecting the operating efficiency of the power plant.

The movement of marine pollutants is affected by tidal current, wind power and cold source water intake. For a specific area, the tidal current has periodic characteristics. Therefore, the movement trajectory of pollutants can be analyzed and predicted under the condition of grasping the characteristics of regional tidal current and water intake. Therefore, combined with on-site monitoring, the time for pollutants to reach the water intake door can be calculated, providing effective early warning information for Binhai Power Plant operating units, thereby providing effective technical support for the disaster prevention and mitigation work of Binhai Power Plant.

SUMMARY OF THE INVENTION

Aiming at the problems existing in the prior art, the present invention provides a method for predicting the movement trajectory of marine pollutants and a safety warning method for water intake in a coastal power plant.

The present invention is implemented in this way, a method for predicting the movement trajectory of marine pollutants and the safety early warning method for water intake in a coastal power plant, which is characterized in that: it includes the following steps:

(1) Establishing a mathematical model of tidal currents: First, according to the characteristics of the engineering area, a mathematical model of large-scale tidal currents is established. The distance between the outer sea boundary and the engineering location is 50-100 km; Pressure assumption; use tide forecasting software Chinatide to provide tidal level boundary data, and verify the validity of various parameters of the mathematical model in the sea area of the project by verifying the actual hydrological data, and ensure the accuracy of the tidal mathematical model;

(2) Establish a particle tracking model: the floating pollutants that are discrete, have no self-swimming ability or have weak self-swimming ability entering the open channel are generalized into particles in the mathematical model; the particle tracking model uses the Langevin equation to describe the particle migration movement;

(3) Determine the particle source release point: take the project water intake as the center, and set up several particle source release points in the surrounding sea area according to the distance and orientation;

(4) Statistical particle flux and distribution: According to the mathematical model of tidal flow and particle tracking model, calculate the movement trajectory of particles with the tidal current and open channel water intake after pollutants are released at different points at different times and different tidal patterns, and count the particle trajectories. The flux and distribution of the sewage interception net through the water intake; at this time, the trajectory prediction of pollutants is completed;

(5) Make a probability cloud map: According to the statistical results, make a probability cloud map of pollutants entering the open channel, and evaluate the impact of pollutants on the safety of water intake. Through the probability cloud map, the dangerous degree of the direction of the pollutants can be determined, and the monitoring of this direction should be strengthened. , by providing the performance of the observation equipment, the longer the monitoring range and distance, the more time for countermeasures;

(6) Real-time monitoring and marking: carry out real-time monitoring of pollutants according to the site, mark the pollutants that have entered the observation scope of the project area in time, and grasp the location, orientation and time from the water intake;

(7) Predict the follow-up trajectory of the marked particles: input the marked particle information into the particle mathematical model, calculate the follow-up trajectory of the marked particles and calculate the time to the water intake through the calculation of the particle mathematical model, which is the engineering operation unit Provide early warning and take timely emergency measures, including deploying personnel and equipment in advance to improve cleaning capacity, or selecting different salvage plans according to the type of pollutants.

Preferably, the measured hydrological data in step 1 mainly includes tidal level, flow velocity, and flow direction data.

Preferably, the objects with no self-swimming ability or weak self-swimming ability in step 2 include one or more of foams, straws, branches, plastics and aquatic plants.

Preferably, in step 3, with the project water intake as the center, a particle release point is set within a distance of 10km and every 1km, and a direction is 22.5°.

Preferably, in step 4, the movement of different points after the pollutants are released at the time of sudden rise, the time of daily limit, the time of sudden fall, and the time of fall and stop are calculated.

Advantages and technical effects of the present invention: by establishing a numerical model of the movement of pollutants in the sea area of the Binhai Power Plant, the present invention proposes the key monitoring range and orientation of pollutants by counting the probability of pollutants entering the water intake, and provides guidance for on-site monitoring. By combining the method of on-site monitoring and numerical simulation, the movement trajectory of pollutants found in the sea area around Binhai Power Plant can be quickly calculated, and the time when the pollutants move to the water intake gate can be predicted. Deal with the problem of sudden influx of pollutants, and provide early warning information for the operation department of the power plant.

Since the present invention adopts the above technical solution, the power plant operation department can strengthen the monitoring of key areas in the engineering sea area, and after finding that a large amount of pollutants enters the key areas, the emergency plan can be quickly activated in advance, and emergency resources can be allocated to effectively solve the problem of responding to the sudden influx of pollutants. The problem of unit shutdown caused by entering the water intake and failure to clean up the garbage in time improves the operation efficiency of the power plant.

Description of drawings

Fig. 1 is a flow chart of the present invention for predicting the movement trajectory of marine pollutants and for early warning of water intake safety in Binhai Power Plant.

2 is a topographic and grid map of the engineering scope of an application embodiment of the present invention;

Fig. 3 is the tide level verification curve graph;

Fig. 4 is the verification curve diagram of flow velocity and flow direction;

Figure 5 is a schematic diagram of the release position of pollutants;

Figure 6 is a diagram of the movement trajectory of pollutants released at a distance of 1 km from the embankment head in the direction of WSW and at the time of emergency;

Fig. 7 is the probability distribution diagram of the flux of pollutants entering the open channel at different positions at the time of surge.

Detailed ways

In order to make the objectives, technical solutions and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention, but not to limit the present invention.

Please refer to FIG. 1, a method for predicting the movement trajectory of marine pollutants and the safety early warning method for water intake of a coastal power plant, which is characterized in that: it includes the following steps:

(1) Establishing a mathematical model of tidal currents: First, according to the characteristics of the engineering area, a mathematical model of large-scale tidal currents is established. The distance between the outer sea boundary and the engineering location is 50-100 km; Pressure assumption; use tide forecasting software Chinatide to provide tidal level boundary data, and verify the validity of various parameters of the mathematical model in the sea area of the project by verifying the actual hydrological data, and ensure the accuracy of the tidal mathematical model;

(2) Establish a particle tracking model: the floating pollutants that are discrete, have no self-swimming ability or have weak self-swimming ability entering the open channel are generalized into particles in the mathematical model; the particle tracking model uses the Langevin equation to describe the particle migration movement;

(3) Determine the particle source release point: take the project water intake as the center, and set up several particle source release points in the surrounding sea area according to the distance and orientation;

(4) Statistical particle flux and distribution: According to the mathematical model of tidal flow and particle tracking model, calculate the movement trajectory of particles with the tidal current and open channel water intake after pollutants are released at different points at different times and different tidal patterns, and count the particle trajectories. The flux and distribution of the sewage interception net through the water intake; at this time, the trajectory prediction of pollutants is completed;

(5) Make a probability cloud map: According to the statistical results, make a probability cloud map of pollutants entering the open channel, and evaluate the impact of pollutants on the safety of water intake. Through the probability cloud map, the dangerous degree of the direction of the pollutants can be determined, and the monitoring of this direction should be strengthened. , by providing the performance of the observation equipment, the longer the monitoring range and distance, the more time for countermeasures;

(6) Real-time monitoring and marking: carry out real-time monitoring of pollutants according to the site, mark the pollutants that have entered the observation scope of the project area in time, and grasp the location, orientation and time from the water intake;

(7) Predict the follow-up trajectory of the marked particles: input the marked particle information into the particle mathematical model, calculate the follow-up trajectory of the marked particles and calculate the time to the water intake through the calculation of the particle mathematical model, which is the engineering operation unit Provide early warning and take timely emergency measures, including deploying personnel and equipment in advance to improve cleaning capacity, or selecting different salvage plans according to the type of pollutants.

The technical scheme that the present invention further adopts is as follows:

Preferably, the measured hydrological data in step 1 mainly includes tidal level, flow velocity, and flow direction data. The purpose of selecting the above-mentioned tidal level, flow velocity and flow direction hydrological data is to ensure that the mathematical model can truly simulate the tidal flow characteristics of the engineering area through the verification of the above parameters, which can further provide a reliable mathematical model basis for particle motion simulation.

Preferably, the pollutants in step 2 refer to objects with no self-swimming ability or weak self-swimming ability, including one or more of foam, straw, branches, plastics and aquatic plants. According to the safety accidents of water intake that have occurred, there are many types of pollutants of this type, and compared with biological pollutants with autonomous swimming ability, their water flow followability is good, so this type of pollutants can be simulated by mathematical models.

Preferably, in step 3, with the water intake of the Binhai Power Plant as the center, a particle release point is set within a distance of 10km and every 1km, and a direction is 22.5°. The advantage of using this technical solution is that the spatial position of the engineering sea area is discretized and accurate, which provides a basis for making the probability cloud map of pollutants entering the open channel; in addition, according to the tidal characteristics of different sea areas, pollutants within a range of 10 km are within a tidal cycle. The probability of entering the open channel is very small, so the simulation of particle motion within 10km can meet the needs of early warning.

Preferably, in step 4, the movement of different points after the pollutants are released at the time of sudden rise, the time of daily limit, the time of sudden fall, and the time of fall and stop are calculated. Since the tidal flow velocity has the characteristic of periodic variation, the purpose of using four moments is to discretize the time and simulate the motion of particles at different moments.

Specific engineering examples:

(1) First, establish the mathematical model of the tidal current in the engineering area, and verify the accuracy of the model according to the measured hydrological data;

(1.1) First establish a mathematical model of power flow for a power plant project. The calculation grid is shown in Figure 1. The calculation area is about 54km long from north to south, about 76km wide from east to west, and the outer boundary is up to -50m isobath;

(1.2) Verify the mathematical model of the power flow;

According to the measured hydrological data, it mainly includes tidal level, flow velocity and flow direction data. The verification results are shown in Figure 2 and Figure 3. It can be seen that the calculated results of tide level, flow velocity and flow direction are in good agreement with the measured data and meet the specifications ("Technical Specifications for Water Transportation Engineering Simulation Tests" JTS/T 231-2021) requirements, so the model can be used for power flow calculation in engineering areas.

(2) Establish a particle tracking model: the floating pollutants entering the open channel are mainly plastics, foams and wood, etc., which are generally discrete, and are generalized into particles in the mathematical model. The particle tracking model uses the Langevin equation to describe the migration of particles.

(3)

3.1) First, take the water intake of the project as the center, and divide the surrounding sea area into 16 directions, namely E, ENE, ... i... ENE (every 22.5° is a direction, which takes E as the starting point, rotates counterclockwise, and ENE is the end point, Corresponding to i numbered from 1 to 16), as the direction in which the pollutants appear;

3.2) Set up a number of pollutant source points at different positions in each azimuth distance from the door, such as 1km, 2km, ...j...nkm;

Since the source of pollutants can only be in the water body, assuming that there are water bodies within the nkm range around the project, there are 16n sources of the above pollutants.

3.3) The above positions can be expressed as;

Assuming that the position of the water intake door is (X ₀ , Y ₀ ), the positions of each point are:

The trajectories of pollutants at each location under the action of tidal current and water intake are calculated separately. And according to the following methods to determine the probability of pollutants entering the open channel:

(4) According to the mathematical model of the tidal current and the particle tracking model, after different points release pollutants at different times and different tidal patterns, the movement trajectories of the particles with the tidal current and the water intake of the open channel are calculated, and the traffic flow of the particles through the position of the sewage interception net at the water intake is calculated. The amount and distribution of pollutants; the trajectory prediction of pollutants is completed at this time;

Monitor the pollutant flux of pollutants through the water intake interception net; the pollutant release lasts for 1 hour, and the accumulation of pollutants under each working condition is evaluated by the pollutant flux percentage Pp, where:

Assuming that the pollutants are located at the positions of X(i,j) and Y(i,j) under the kth working condition, the pollution point continuously releases the amount of pollution for 1 hour, the amount of pollutants released per second is pt, and the total amount released is Tp, calculate the movement trajectory of pollutants under this working condition, and the amount of pollutants entering the open channel Ip, then under this working condition, the proportion (probability) of pollutants entering the open channel is

Pp=Ip/Tp

Pp——Percentage of pollutant flux through a section

Ip - pollutant flux through a section

Tp: total pollutant release

The statistical time of pollutant flux is within 24h from the time of pollutant release. The schematic diagram of the pollutant release position is shown in Figure 5. In this embodiment, the model calculation can intuitively see the movement trajectory of the pollutant after the occurrence of the tidal current and the water intake from the open channel. In the direction of WSW, 1km away from the embankment head, the movement trajectory of the particles after the release of the particles is explained; see Figure 5 for details. The dotted line in the figure represents the trajectory, the hollow dots indicate the initial release position of pollutants, and the solid dots indicate 24 hours. last position after.

It can be observed from the figure that after the emergence of pollutants, the pollutants mainly move westward with the rising tide, and during the ebb tide, they move eastward with the ebb current, to the vicinity of the mouth, due to the effect of water intake, the pollutants move into the open channel, and close to the channel. The side of the west embankment moves into the open channel, so it can be judged that the side of the west embankment is a pollutant accumulation area. Therefore, the garbage removal device should be deployed on the side of the west embankment, which should be considered in the design.

(5) According to the statistical results under each working condition, make a cloud map of the probability of pollutants entering the open channel, and evaluate the impact of pollutants on the safety of water intake; in this embodiment, according to the above calculation method, the movement of pollutants under different working conditions is repeatedly calculated In this case, the probability cloud map as shown in Figure 7 is obtained by statistics.

From the probability cloud map, it can be seen that the pollutants entering the open channel are mainly in the WSW~W direction, and the flux entering the open channel at different times is quite different. , almost no pollutants enter the open channel. Therefore, during on-site observation, the monitoring of pollutants within 6km inward from WSW to W should be strengthened. According to the performance of on-site monitoring equipment, the monitoring range can be appropriately expanded.

(6) Real-time monitoring and marking: carry out real-time monitoring of pollutants according to the site, mark the pollutants that have entered the observation scope of the project area in time, and grasp the location, orientation and time from the water intake;

(7) According to the real-time monitoring of pollutants on site, timely record the pollutants that have entered the observation range of the project area; input the pollutant information into the particle mathematical model, predict the subsequent trajectory of the pollutant and calculate it to the water intake At the same time, the operation unit of Binhai Power Plant will give an early warning and take emergency measures in a timely manner. The specific operation in this embodiment is as follows: by observing the pollution situation on site, and inputting the position and time of the pollutant into the mathematical model, the movement trajectory and the time to reach the open channel can be obtained, and an early warning can be provided for the Binhai Power Plant operating unit, which can be used in advance for emergency management. Reserve a certain amount of time and take emergency measures in a timely manner, including deploying personnel and equipment in advance to improve the cleaning capacity, or choosing different salvage plans according to the type of pollutants.

Through the above technical solutions, the floating pollutants in the sea area near the water intake of Binhai Power Plant are marked by on-site observation, and their subsequent motion trajectories are predicted, and the probability of entering the open channel and the time of arrival are calculated, which directly contributes to the safety of the cold source of Binhai Power Plant. The department issued an early warning to reduce the risk of unit shutdown caused by pollutant accumulation in Binhai Power Plant and improve the operation efficiency of Binhai Power Plant.

The above descriptions are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present invention shall be included in the protection of the present invention. within the range.

Claims (5)

1. A marine pollutant motion trail prediction and coastal power plant water taking safety early warning method is characterized by comprising the following steps: the method comprises the following steps:

(1) establishing a tidal current mathematical model: firstly, establishing a large-range tidal current mathematical model according to the characteristics of a project area, wherein the distance between an open sea boundary and a project position is 50-100 km; the mathematical model is based on fluid incompressibility and Navier-Stokes equations and obeys Boussinesq assumption and hydrostatic pressure assumption; providing tide level boundary data by using tide forecasting software Chinatade, and verifying hydrologic actual measurement data to ensure the validity of various parameters of a mathematical model under the engineering sea area and ensure the accuracy of the tide mathematical model;

(2) establishing a particle tracking model: floating pollutants which are in a scattered state, have no self-swimming capability or weak self-swimming capability and enter the open channel are generalized into particles in a mathematical model; the particle tracking model adopts a Langevin equation to describe the migration motion of the particles;

(3) determining a particle source release point: respectively arranging a plurality of particle source release points in the surrounding sea area according to the distance and the direction by taking the engineering water intake as a center;

(4) counting the flux and distribution of the particles: calculating the motion tracks of the particles under the action of the tidal current and the open channel water taking after pollutants are released at different points at different moments and different tidal modes according to the tidal current mathematical model and the particle tracking model, and counting the flux and the distribution condition of the particles passing through the position of the water intake trash rack; at the moment, the pollutant movement track prediction is finished;

(5) making a probability cloud picture: according to the statistical result, a probability cloud picture of the pollutants entering the open channel is made, the influence of the pollutants on water taking safety is evaluated, the coming danger degree of the pollutants can be judged through the probability cloud picture, the monitoring of the direction is emphasized, and the time of measures is reserved as the performance of observation equipment is provided, and the monitoring range and the distance are farther;

(6) real-time monitoring and marking: carrying out real-time monitoring on pollutants on site, timely marking the pollutants entering an observation range of an engineering area, and mastering the positions, the directions and the time of the pollutants from a water intake;

(7) predicting the subsequent motion track of the marked particle: inputting the marked particle information into a particle mathematical model, predicting the subsequent motion track of the marked particle and calculating the time from the subsequent motion track to a water intake through the calculation of the particle mathematical model, providing early warning for engineering operation units, and taking emergency measures in time, wherein the emergency measures comprise allocating personnel and equipment in advance to improve the cleaning capacity or selecting different salvage schemes according to the types of pollutants.

2. The marine pollutant motion trail prediction and coastal power plant water intake safety early warning method according to claim 1, characterized in that: the measured hydrological data in step 1 mainly includes tide level, flow rate and flow direction data.

3. The marine pollutant motion trail prediction and coastal power plant water intake safety early warning method according to claim 1, characterized in that: the objects without self-swimming ability or weak self-swimming ability in the step 2 comprise one or more of foam, straws, branches, plastics and aquatic weeds.

4. The marine pollutant motion trail prediction and coastal power plant water intake safety early warning method according to claim 1, characterized in that: in step 3, a particle release point is arranged within the range of 10km from the engineering water intake as the center and at intervals of 1km, and 22.5 degrees is taken as a direction.

5. The marine pollutant motion trail prediction and coastal power plant water intake safety early warning method according to claim 1, characterized in that: and 4, calculating the motion conditions of different point positions after pollutants are released at the rising and stopping time, the falling and stopping time.

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