JPH03110492A - Detection of underwater suspended matter - Google Patents

Abstract

PURPOSE:To easily and surely detect underwater suspended matter by oscillating ultrasonic wave toward a plurality of echo sounder receivers arranged and provided underwater from an ultrasonic oscillator provided underwater and sensing fluctuation of the intensity distribution of ultrasonic wave. CONSTITUTION:An ultrasonic wave oscillator 3 is provided underwater in one side in the vicinity of the place wherein medusas 6 being suspended matter to be detected pass. A plurality of echo sounder receivers 4 are provided at many rows and many steps toward the oscillator 3 underwater in the other side. Intensive ultrasonic wave 5 is oscillated toward the receivers 4 from the oscillator 3. Then existence of medusas 6 is detected from change in intensity distribution of ultrasonic wave received by the respective receivers 4. In this case, straightly progressed ultrasonic wave and refracted ultrasonic wave exist in the place wherein medusas 6 float. Therefore intensity of ultrasonic wave received by the respective receivers 4 differs and the status thereof is timely changed. Accordingly medusas 6 are detected by fluctuation of intensity distribution and timely fluctuation.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Detailed Description] The present invention relates to a method for detecting floating objects in water, such as large swarms of jellyfish, etc., on one side of a cooling water intake in a power plant or other plant. This is used as a signal to detect floating objects in the water when detecting the arrival of floating objects in the water and taking measures to prevent the floating objects from entering the water intake. .

[Conventional technology]

Conventionally, seawater has been used as cooling water when condensing steam for power generation, but sometimes jellyfish occur in the seawater, and the jellyfish are sucked in from the cooling water intake along with the seawater and filtered. This can lead to blockages in the cooling water supply, reducing the amount of cooling water and making it impossible for the power plant to operate.

In order to prevent this, for example, as a first means, Japanese Patent Publication No. 62-6044, as a second means, Japanese Patent Application Laid-Open No. 61-254712, and as a third means, Japanese Patent Application Laid-Open No. 51-139146. As a fourth means, a method described in Japanese Utility Model Application Laid-open No. 61-134274 is known.

However, in the first method described above, the flow rate of the heated wastewater is increased and it is discharged from the water outlet below the sea surface, and cooling water is flowed in at a small flow rate from the water intake below that, which causes a large amount of jellyfish to be generated. In such a case, although the flow rate is small, it cannot be expected to prevent the jellyfish from being sucked into the water intake.
A net is installed to prevent the inflow of jellyfish.If a large number of jellyfish occur, they will inevitably attach to the net and reduce the amount of water intake. This method attempts to collect jellyfish near the water intake, and it is extremely difficult to prevent jellyfish that have spawned in large quantities from being sucked into the water intake.

Therefore, the present inventors developed an underwater system that prevents jellyfish and garbage from being sucked into the cooling water intake even if a large number of jellyfish occur or a large amount of garbage is floating in the sea. Proposed a device for removing floating objects, and filed a patent application in 1983
No. 43440, Utility Application No. 1-43011, Patent Application No. 1-1
No. 24197, Japanese Patent Application No. 1-124198, Utility Application No. 1-
No. 57089, Jitsugan No. 1-58165, Jitsugan No. 1-5
The application has been filed as No. 8186.

In the above application, an upflow generator is installed on the seabed in front of the cooling water intake, and the upflow generator generates an upflow, and the floating objects such as jellyfish and garbage in the sea are removed by the upflow. The floating objects are placed on the water and floated near the water surface to prevent the objects floating in the water from approaching the water intake port.

[Problem to be solved by the invention]

However, the above-mentioned application uses an upflow generating device,
Since the operation is performed in anticipation of the arrival of floating objects in the water, there is a problem in that, as a result, operation when the floating objects in the water do not arrive becomes a wasteful operation and is not economical.

The present invention relates to a method for detecting floating objects in water that can solve the above problems.

That is, an object of the present invention is to provide a method for detecting floating objects in water that can reliably detect the presence or absence of floating objects in water and prevent wasteful operation of a device for removing floating objects in water. It is something.

[Means to solve the problem]

In order to achieve the above object, the underwater floating object detection method of the present invention includes installing an ultrasonic oscillator in the water on one side near the point where the underwater floating object to be detected passes; A plurality of receivers are arranged and installed in the water on the other side facing the ultrasonic oscillator, and ultrasonic waves are oscillated from the ultrasonic oscillator toward the receiver, and the number of receivers is The presence or absence of floating objects in the water is detected according to variations in the intensity distribution of the received ultrasonic waves.

[Effect]

According to the present invention, since ultrasonic waves are oscillated from an ultrasonic oscillator installed underwater to a plurality of receivers installed in a plurality of arrays underwater, there may be a group of jellyfish, etc. between the ultrasonic oscillator and the receiver. If there are objects floating in the water, the ultrasonic waves are reflected and refracted within the objects floating in the water. However, floating objects such as jellyfish, which have acoustic properties quite similar to those of seawater, reflect only a small amount of sound, making it difficult to detect with a reflection-type ultrasonic detector. On the other hand, if there is a slight change in acoustic characteristics, ultrasonic waves will be refracted unless they are incident perpendicularly to the surface of a floating object.

Therefore, the intensity distribution of the ultrasonic waves received by each of the receivers becomes different compared to when there is no floating object in the water, so it is possible to detect floating objects in the water depending on the variation in the intensity distribution. can.

〔Example〕

1 and 2 show an example of an apparatus for carrying out the detection method of the present invention.

In the figure, 1 is a water surface, 2 is a seabed, 3 is an ultrasonic oscillator, 4 is a receiver, 5 is an ultrasonic wave, and 6 is a jellyfish.

To explain further, an ultrasonic oscillator 3 and a wave receiver 4 are installed underwater at a certain height from the seabed 2 in front of a cooling water intake of a power plant (not shown). That is, an ultrasonic oscillator 3 is installed in the water on one side near the point where the jellyfish 6, which is the floating object in the water, passes through, and a receiver 4 is placed in the water on the other side facing the ultrasonic oscillator 3. It is installed in multiple rows and stages.

First, a strong ultrasonic wave 5 is emitted from the ultrasonic oscillator 3 toward the receiver 4, and then the ultrasonic wave 5 is transmitted to each of the receivers 4, 4.・・・
・The presence or absence of jellyfish 6 is detected from changes in the intensity distribution of the ultrasonic waves received.

That is, in the place where the jellyfish 6 is floating, the ultrasonic waves emitted from the ultrasonic oscillator 3 have a portion that travels straight and a portion that is refracted. The intensity of the ultrasonic waves received by ... differs, and the different appearance changes over time. Therefore, each receiver 4, 4 . Since the intensity distribution of the ultrasonic waves received by ... will be different compared to the case where there is no jellyfish 6, the jellyfish 6 can be detected based on the fluctuations in the intensity distribution and the temporal fluctuations.

For example, when there is a jellyfish 6, as shown by curve a in FIG. 3 (a) or curve a in FIG. The intensity distribution of the ultrasonic waves received by ... fluctuates, resulting in a temporally unstable distribution, but in the absence of jellyfish 6, the intensity distribution is relatively stable, as shown by the curve in Figure 4. are doing.

Therefore, the presence or absence of the jellyfish 6 can be detected from the difference between the curves a and a'.

In this way, when it is detected that the jellyfish 6 has arrived, this detection signal is input to the jellyfish removal device (not shown), which starts immediately, and the jellyfish 6 enters the cooling water intake. Make sure you have nothing to do.

In addition, in the example illustrated above, the jellyfish 6 was explained, but
For example, detection of floating objects in water such as garbage can be performed in the same manner. In addition, in order to avoid the effects of reflection from the water surface, the seabed, etc., the ultrasonic waves from the ultrasonic oscillator are made into short pulses (for example, several milliseconds) and the repetition rate is long (for example, several seconds). ,
Additional processing can be performed, such as capturing signals only for a few milliseconds after the transmission time of ultrasonic waves in seawater between the oscillator and the receiver has elapsed.

〔Effect of the invention〕

As explained above, according to the present invention, ultrasonic waves are oscillated from an ultrasonic oscillator installed underwater toward a plurality of receivers arranged in an array underwater, and are received by each of the receivers. Since this method detects the presence or absence of floating objects in water according to changes in the intensity distribution of ultrasonic waves, it is possible to extremely easily and reliably detect the presence or absence of floating objects in water, which cannot be detected with reflective sensors. There is an effect that can be achieved.

[Brief explanation of drawings]

Fig. 1 is a partially sectional front view showing an example of an apparatus for carrying out the method of the present invention, Fig. 2 is a plan view thereof, Fig. 3 (a),
(b) is an explanatory diagram of the intensity distribution of the ultrasonic waves received by the receiver of FIG. 1 when there is a jellyfish, and FIG. 4 is a similar explanatory diagram when there is no jellyfish. 1... Water surface, 2... Seabed, 3... Ultrasonic oscillator,
4...Receiver, 5...Ultrasonic wave, 6...Jellyfish. Patent applicant Ishikawajima Harima Heavy Industries Co., Ltd. No. 3

Claims (1)

[Claims] 1. An ultrasonic oscillator is installed in the water on one side near the point where the underwater floating object to be detected passes, and the ultrasonic oscillator is installed in the water on the other side of the point where the underwater floating object passes through. A plurality of receivers are arranged and installed facing each other, and the ultrasonic oscillator oscillates ultrasonic waves toward the receiver, and each receiver responds to fluctuations in the intensity distribution of the ultrasonic waves it receives. A method for detecting floating objects in water, comprising: detecting the presence or absence of the floating objects in water. 2. An ultrasonic oscillator and a wave receiver are installed in front of a cooling water intake into which seawater is introduced as cooling water to detect floating objects in the water that are about to enter the cooling water intake. How to detect floating objects in water. 3. The method for detecting floating objects in water according to claim 2, wherein the floating objects in water are a group of jellyfish. 4. The oscillated ultrasonic wave is a pulse wave, and after the ultrasonic oscillator emits the pulse wave, the reception signal of the receiver is transmitted for a short time after the transmission time of the ultrasonic wave in the sea between the oscillator and the receiver has elapsed. The method for detecting floating objects in water according to claim 1, 2 or 3, wherein the method is used as a signal for detecting floating objects in water.