JPH0531926B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a method for investigating the diffusion of thermal wastewater in marine surveys.

<Conventional technology> Thermal drainage diffusion investigation in ocean research is an important investigation when conducting ocean development work.

This thermal wastewater diffusion survey requires measuring the position of ships on the ocean, seawater flow velocity, and underwater temperature and water quality measurements.

The current method of investigating thermal wastewater diffusion is to install multiple fixed propeller-type current meters in the sea at different measurement depths, and to place water thermometers and water quality meters on ships, etc. at each measurement depth. Water temperature and other measurements are being taken while being towed.

However, since the tide level changes from moment to moment, the height of the ship on the ocean also changes, making it impossible to obtain accurate water depth measurements.

Therefore, in order to obtain accurate water depth measurements, it is necessary to separately measure the tide level.

Later, on a desk, the height of the ship from the reference point is corrected based on the tide level record, and the measured water depth is determined from that height.

The various measured values obtained in the above manner are combined and analyzed to measure the diffusion of heated wastewater.

<Problems to be Solved by the Present Invention> The conventional heated wastewater diffusion investigation method described above has the following problems.

<B> Measurements of seawater flow conditions, temperature and water quality, and ship position measurements are carried out separately, making it impossible to obtain information on the same value and time.

Therefore, there is a problem with the accuracy of the data.

<B> Since each measurement value is obtained separately and the measurement method is extremely primitive, it takes an enormous amount of time and effort to later combine and analyze the measurement values.

<C> Only one piece of information can be obtained from a current velocity meter at one location, and in order to know the current velocity in the entire survey area,
A huge number of current meters are required.

Therefore, installing a current meter requires a great deal of labor and expense.

Furthermore, installation becomes difficult when the water is deep or the current is fast.

<D> Because the ocean is public, special permission is required to install a current meter, and surveys are often difficult due to issues such as power source locations and compensation issues and coordination of interests with those involved in the fishing industry.

<Objective of the present invention> The present invention was made in order to solve the above-mentioned problems, and it is an object of the present invention to provide a method for investigating thermal wastewater diffusion that is highly accurate and can reduce time, labor, and cost. With the goal.

<Structure of the present invention> An embodiment of the present invention will be described below with reference to the drawings.

As shown in the system diagram of Figure 1, the thermal wastewater diffusion survey method of the present invention performs three measurements: measuring the position of a ship on the ocean, measuring the temperature and water quality in the water, and measuring the flow state of seawater. The measured values are recorded on the same magnetic tape as information at the same location and time and unified, and the unified information is quickly analyzed and processed using a large computer.

<B> Measuring the position of ships at sea Accurately measuring the position of ships at sea is the basis of all marine surveys.

Since the ship's position changes from moment to moment, it is necessary to record it according to the time and link it with other information.

This system is equipped with these various positioning technologies and a subsystem that uses them to guide ships to predetermined areas or measurement lines.

In the present invention, as shown in FIG. 2, the ship position is measured using a light wave range finder 1.

The light wave rangefinder 1 is a device that can measure the position of an object from a remote location, and has an extremely high measurement accuracy of 1 to 2 cm at a distance of 1 km.

In other words, as is well known, there is a light wave range finder 1 on land.
A reflecting mirror 2 is placed on the ship.

The relationship between the coordinates and direction of the light wave rangefinder 1 on land and the mechanical height have been accurately measured.

Therefore, the XY coordinates of the ship can be determined simply by measuring the reflected light from the reflecting mirror 2 on the ship and by measuring the horizontal plane using the light wave range finder 1.

Furthermore, since the difference between the height and the mechanical height of the light wave rangefinder 1 can be measured, the height of the reflecting mirror 2 on the ship above the ground can also be determined at the same time. That is, the XY coordinates and ground height of the ship, that is, the three-dimensional coordinates of the ship can be determined at the same time.

<B> Ship position guidance method The measured values obtained as described above are converted into a telemeter signal 5 by the telemeter 3 and transmitted to the ship.

Onboard the ship, measurements taken from the ground can be immediately projected onto a display and printed out if necessary.

The person in charge of the ship compares this projected point with the planned line to be measured, and if there is a discrepancy, corrects the direction and guides the ship in the correct direction.

At the time of guidance, the ship is guided so that it sails on the measurement line 4 while keeping the ship's direction accurate using a gyroscope.

<C> Measurement of seawater flow conditions Generally speaking, the speed and direction of seawater flow is called the flow regime.

As shown in Figure 3, when an ultrasonic pulse is emitted into the water from the transducer 6 installed on the side of the ship, this ultrasonic pulse propagates through the water and some of it is scattered by underwater objects. It is reflected and returns to the transducer 6.

At this time, the frequency of the reflected signal from the scattering object deviates from the frequency of the transmitted signal in proportion to its moving speed and moving direction.

This phenomenon is widely known as the Doppler effect, and the principle of this measurement is to convert this frequency deviation into a flow velocity vector for calculation.

As shown in Figure 3, this device emits ultrasonic pulses in four directions perpendicular to each other at an angle of 60 degrees, and when converting the reflected signals in these four directions into flow velocity, rolling,
This method removes the influence of agitation such as pitching and obtains the three-dimensional vector quantity of the flow velocity in the XYZ directions.

This makes it possible to simultaneously measure current velocity vectors for up to 16 layers in the water depth direction once every 30 seconds while the ship meanders.

These measured values are quickly processed by a large computer and output in real time to a television cathode ray tube as shown in FIG.

Therefore, it is possible to immediately examine the current velocity and its direction at multiple levels of water depth onboard the ship.

By combining it with the above-mentioned precise ship position (ship position) measurement or ship position guidance system, it is possible to accurately measure the entire current velocity in a given sea area in a very short time (1 to 2 hours). can.

<d> Measurement of temperature, etc. in water Measuring the temperature distribution and water quality distribution in water is essential information for investigating the diffusion range of heated wastewater.

Particularly for thermal wastewater diffusion studies, the relationship between seawater flow velocity and temperature is an important investigation item, and this system can simultaneously measure and analyze such information, which was conventionally collected separately.

The measurement involves connecting a plurality of thermosensors 7 with built-in water pressure gauges or water quality sensors to each measuring water depth using φ6 mm stainless wires, etc., and recording the three-dimensional temperature distribution of the sea area while being towed.

Note that water depth sensors are provided at both upper and lower ends of this group of thermosensors 7.

The electromagnetic induction transmission method is used to transfer data from the sensor, and high-speed data sampling enables real-time analysis processing on board.

This is done at the same time as the current velocity measurement method described above, and is recorded on the same magnetic tape along with accurate ship position information.
By processing with a large computer, a series of steps from measurement to analysis can be performed continuously.

<Thermal wastewater diffusion survey> Next, we will explain the thermal wastewater diffusion survey method.

The seawater current velocity survey uses the method described above to measure tidal currents in up to 16 vertical layers three-dimensionally in real time.

The resolution of the flow velocity is 1 cm/sec.

At the same time, water temperature and water quality surveys will be conducted onboard the ship using the methods described above.

The navigation line during measurements is taken while ensuring accurate positioning using the ship's position guidance system.

Each measurement value obtained in this way is
It is recorded on a magnetic tape as information at the same time, quickly subjected to simulation analysis processing using a large-scale computer, and then output to a television CRT.

The measurement results are supplemented to the mesh data by the spline method as shown in Figure 5, and the water temperature is determined as a horizontal distribution of the standard deviation of the difference from the reference water temperature as shown in Figure 6.

Based on such survey data, we will understand the ocean area characteristics and distribution characteristics of thermal wastewater dispersion.

<Effects of the Present Invention> Since the present invention has been described above, the following effects can be expected.

<A> The present invention simultaneously measures the flow state of seawater, the temperature and water quality distribution in the water, and the position of a ship on the ocean using ultrasonic waves.

Then, those measured values can be obtained as information at the same location and at the same time.

Therefore, the accuracy of information is improved.

<B> The time, ship position, flow conditions, etc. are recorded on the same magnetic tape.
Record temperature and water quality information. Using these measured values and measurement times, the state of diffusion of heated wastewater is determined.

Therefore, everything from measurement to analysis processing using a large computer can be carried out continuously, resulting in significant time and labor savings.

<C> Since each piece of information is subjected to simulation analysis and outputted to a TV CRT in real time, it is possible to immediately check and consider it on board the ship and manage it on the spot.

This has made it possible to conduct highly accurate surveys.

<d> Since the present invention has a structure in which ultrasonic pulses are emitted into the water from a transducer installed on the side of the ship, there is no need to install a huge number of current meters underwater as in the past. There is no.

Therefore, time, effort, and cost can be significantly reduced.

<E> By combining seawater current measurement with precise ship positioning or ship position guidance systems, it is possible to accurately determine the entire flow situation in a given sea area.
Measurements can be made in a very short time (1 to 2 hours).

<F> Since the present invention allows highly accurate thermal wastewater diffusion surveys to be conducted, it can be of great use in planning the installation of structures, surveying fishing reefs, and the like.

[Brief explanation of drawings]

Figure 1: Explanatory diagram showing the system of the present invention, Figure 2
Figure: An explanatory diagram showing the method for measuring the position of a ship on the ocean, Figure 3: An explanatory diagram showing the method for measuring the flow state of seawater, Figures 4 and 5
Figure: An explanatory diagram of the method of displaying the measurement results of seawater flow conditions. Figure 6: An explanatory diagram of the method of displaying the measurement results of water temperature, etc.

Claims (1)

[Claims] 1. In a method for investigating thermal wastewater diffusion in marine research, a ship is guided in a predetermined direction, the three-dimensional position of the ship on the ocean is measured, and ultrasonic waves are emitted into the sea, and the Doppler effect is used to measure each water depth. Measure the flow conditions in each layer corresponding to the water depth, place thermosensors and water quality sensors in each layer corresponding to each water depth, measure the temperature distribution in each layer while towing, and use these measured values and measurement times to A method for investigating thermal wastewater diffusion in ocean research, which is characterized by: determining the state of diffusion of thermal wastewater.