JP6212894B2 - Liquid level measurement system and liquid level measurement method - Google Patents

Description

  The present invention relates to a liquid level measurement system and a liquid level measurement method for measuring a liquid level of a liquid stored in a storage facility.

  As an apparatus for measuring the liquid level of the liquid stored in the storage facility, for example, a triangulation photoelectric sensor (also referred to as a position sensor or a displacement sensor) shown in Patent Document 1 can be used. The triangulation photoelectric sensor of Patent Document 1 projects light from a light projecting unit toward an object, receives reflected light irregularly reflected from the object at a light receiving unit (light receiving element), and receives the light from the light receiving element. The distance to the object is obtained by obtaining the light receiving spot position on the surface or the barycentric position of the received light amount distribution. In other words, the triangulation photoelectric sensor disclosed in Patent Document 1 detects the distance to an object by triangulation using light.

JP 2007-024653 A

  In a nuclear power plant, a suppression pool (also referred to as a suppression chamber (S / C)) is used as a storage tank for condensing the generated steam to lower the pressure in order to suppress an increase in internal pressure in the reactor containment vessel. Is provided. The suppression pool is stored in a torus room, and areas called triangle corners are adjacent to the four corners of the same floor as the torus room. In this triangular corner, water stored in the suppression pool (stored liquid) may flow, and the development of a method for measuring the water level (liquid level) of the flowing water is being studied.

  The use of ultrasonic waves as a measuring device for measuring the liquid level has been studied, but when measuring the liquid level at the stair landing at the triangular corner, the measurement is made from the gap in the staircase. It is very narrow. Therefore, an ultrasonic wave is not preferable because an incident wave spreads and it is difficult to receive a reflected wave.

  Therefore, as a liquid level measurement method applicable even in a narrow place, use of a displacement sensor using light (laser) as in Patent Document 1 is being studied. However, if the transparency of the stored liquid is high, most of the light passes through the liquid surface and reaches the equipment bottom surface. Then, the intensity of reflected light at the bottom of the facility is too strong, and the liquid level cannot be accurately grasped.

  In view of such problems, the present invention provides a liquid level measurement system and a liquid level measurement method capable of accurately measuring a liquid level even in a narrow place even when the transparency of the stored liquid is high. The purpose is to provide.

In order to solve the above problems, a typical configuration of a liquid level measurement system according to the present invention includes a distance measurement sensor that reflects light on a liquid surface and measures a distance, and a position where light is emitted from the distance measurement sensor. and a bubble generator for generating bubbles under the liquid surface of the bubble generating device is disposed on the liquid surface under pendent from above, characterized in that to generate bubbles in the vicinity of the liquid surface.

  According to the above configuration, since the vicinity of the liquid surface becomes pseudo turbid due to the bubbles generated from the bubble generating device, the transparency of the liquid can be reduced. Thereby, since the light irradiated from the distance measuring sensor is easily diffusely reflected on the liquid surface, the intensity of the reflected light from the liquid surface can be increased. Therefore, it is possible to accurately measure the liquid level in a narrow place even when the transparency of the stored liquid is high. Further, since bubbles are used, the property of the liquid (water quality is not changed).

It said bubble generating devices are disposed below the liquid surface pendent from above. Thereby, the density of the bubbles near the liquid surface can be easily increased. The bubble generating device may generate nitrogen bubbles. As the bubbles generated by the bubble generator, a gas having low reactivity such as nitrogen is suitable. Furthermore, as the distance measuring sensor, a triangular distance measuring method or a pulse distance measuring method can be suitably employed.

  The liquid level measurement system includes a wire that suspends the bubble generating device, a suspension control device that adjusts the length of the wire by detecting whether or not the bubble generating device is arranged below the liquid level by the tension of the wire, May be further provided. Thereby, even if the liquid level is lowered by reducing the amount of liquid stored in the storage facility, the bubble generating device is again placed below the liquid level. Therefore, the above-described effect can be obtained more reliably.

In order to solve the above problems, a typical configuration of a liquid level measuring method according to the present invention includes a distance measuring sensor that reflects light on a liquid surface and measures a distance, and a bubble generating device that generates bubbles in the liquid. The bubble generating device is suspended from above and placed below the liquid level, and bubbles are generated by the bubble generating device in the vicinity of the liquid level where light is irradiated from the distance measuring sensor. And The components corresponding to the technical idea in the liquid level measurement system described above and the description thereof can also be applied to the liquid level measurement method.

  According to the present invention, it is possible to provide a liquid level measurement system and a liquid level measurement method capable of accurately measuring a liquid level even in a narrow place even when the transparency of the stored liquid is high. it can.

It is a figure explaining the liquid level measurement system concerning this embodiment. It is a figure explaining a ranging sensor. It is a figure explaining the implementation of the liquid level measurement system of this embodiment.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. The dimensions, materials, and other specific numerical values shown in the embodiments are merely examples for facilitating understanding of the invention, and do not limit the present invention unless otherwise specified. In the present specification and drawings, elements having substantially the same function and configuration are denoted by the same reference numerals, and redundant description is omitted, and elements not directly related to the present invention are not illustrated. To do.

  FIG. 1 is a diagram illustrating a liquid level measurement system according to this embodiment. In this embodiment, the water storage facility 150 is exemplified as the storage facility, and the case where the liquid level of the liquid stored therein, that is, the water level of the stored water is measured is described as an example. However, the present invention is limited to this. It is not a thing. The liquid level measurement system 100 and the liquid level measurement method according to the present embodiment can naturally measure the liquid level of liquids other than water, for example, liquids such as oil and chemicals.

  As shown in FIG. 1, the liquid level measurement system 100 of this embodiment includes a distance measuring sensor 110 and a bubble generation device 120. The distance measuring sensor 110 measures the distance by reflecting light on the water surface 104 (liquid surface). The bubble generation device 120 generates bubbles below the water surface 104 where light is emitted from the distance measuring sensor 110. In FIG. 1, the distance measuring sensor 110, the wires 108a and 108b, and the suspension control device 130 are attached to the rigid frame 106, and the bubble generating device 120 is suspended by the wire.

  FIG. 2 is a diagram for explaining the distance measuring sensor 110. In the distance measuring sensor 110 shown in FIG. 2, light (laser light) from the semiconductor laser 112 (light projecting unit) is focused by the light projecting lens 114 and irradiated onto the water surface 104a. The reflected light reflected on the water surface 104a is collected by the light receiving lens 116 and received by the light receiving element 118 (light receiving unit). At this time, the reflected light reflected on the water surface 104a is received at the point A by the light receiving element 118, and the reflected light reflected on the water surface 104b higher than the water surface 104a is received at the point B by the light receiving element 118. The distance to the water surface, that is, the water level (displacement amount) can be measured from the light receiving position (imaging position) in the light receiving element 118.

  In the present embodiment, a triangulation type distance measuring sensor has been described as an example of the distance measuring sensor 110. However, the present invention is not limited to this. As the distance measuring sensor 110, for example, a distance measuring sensor such as a pulse distance measuring method may be used.

  As shown in FIG. 1, the bubble generator 120 is connected to a pump 124 by a tube 122. Thereby, the gas sent out by the pump 124 is ejected from the bubble generating device 120 as the bubble 102. As the gas sent out by the pump 124, that is, the bubble 102 generated by the bubble generation device 120, a gas having low reactivity is preferable, and for example, nitrogen can be suitably used. In addition, in this embodiment, although the structure which generates a bubble using the bubble generation apparatus 120 was illustrated, it is not limited to this. For example, a foam or the like that generates bubbles when placed in a liquid (in water) can be used instead of the bubble generator 120.

  By arranging the bubble generating device 120 below the water surface (near the water surface 104), bubbles 102 are generated from the bubble generating device 120 below the water surface. Then, since the vicinity of the water surface 104 becomes pseudo turbid due to the bubbles 102, the transparency of the water is lowered, and the light irradiated by the distance measuring sensor 110 is easily diffusely reflected on the water surface. That is, the bubble 102 acts as a reflector. Thereby, since the intensity | strength of the reflected light from the water surface 104 can be raised, even if the transparency of the water stored is high, it becomes possible to measure a water level correctly.

  In particular, in the present embodiment, the bubble generating device 120 is suspended from above and disposed below the water surface. If the bubble generating device 120 is placed on the bottom surface of the water storage facility, the bubbles 102 from the bubble generating device 120 may not reach the vicinity of the water surface 104, and the above-described effects may not be sufficiently obtained. In addition, when the bubble generator 120 is placed on the bottom surface of the water storage facility, the position may be shifted due to the flow of water. To correct the position, the bubble generator 120 must be taken out of the water once. A cumbersome work is required.

  On the other hand, since the bubble generating device 120 can be suitably placed near the water surface by suspending the bubble generating device 120 from above by the wires 108a and 108b and placing it below the water surface as in this embodiment, Bubbles 102 can be sufficiently generated in the vicinity of the water surface 104, and the above-described effects can be enhanced. Moreover, if it suspends from upper direction like this embodiment, even if the position of the bubble generation apparatus 120 may shift | deviate, it is possible to correct a position easily.

  In particular, in the present embodiment, the suspension control device 130 detects whether or not the bubble generating device 120 is disposed below the liquid surface by the tension of the wires 108a and 108b, and the wires 108a and 108b are detected according to the detection result. The length is adjusted. As a result, even if the amount of water stored in the water storage facility 150 is reduced and the water level is lowered, the suspension control device 130 detects that the bubble generating device 120 is above the water surface, and the length of the wires 108a and 108b is reduced. Once adjusted, the bubble generator 120 is again placed below the surface of the water. Therefore, the water level can be measured more reliably.

  In addition, although the structure provided with the suspension control apparatus 130 was illustrated in this embodiment, it is not limited to this. However, since the water level fluctuates up and down, when the configuration is not provided with the suspension control device 130, the length of the wire is set so that the bubble generating device 120 is below the water surface even at the lowest possible water level. It is desirable to set.

  Next, the liquid level measurement method according to the present embodiment will be described in detail while describing the embodiment of the liquid level measurement system 100 described above. FIG. 3 is a diagram illustrating an embodiment of the liquid level measurement system 100 of the present embodiment, and FIG. 3A is a plan view illustrating a water storage facility 150 to which the liquid level measurement system 100 of the present embodiment is applied. FIG. 3B is a side view of the triangular corner 160 b adjacent to the torus chamber 154.

  In the water storage facility 150 shown in FIG. 3A, the suppression pool 152 is stored in the torus chamber 154, and triangular corners 160 a to 160 d (staircase chambers) are provided to access the torus chamber 154. The stairs 162 provided at the triangular corners 160a to 160d are folded back at the landing 164. Hereinafter, the stairs above the landing 164 are referred to as the upper stairs 164a, and the stairs below the landing 164 are referred to as the lower stairs 164b.

  In the present embodiment, as the water storage facility 150 (storage facility), the triangular corners 160a to 160d adjacent to the torus chamber 154 in which the suppression pool 152 is accommodated are illustrated, but the present invention is not limited to this. The liquid level measurement system 100 of the present embodiment and the liquid level measurement method described later can also be applied to other storage facilities. Since the triangular corners 160a to 160d have the same configuration, the triangular corner 160b is illustrated in the following description and FIG.

  As shown in FIG. 3 (b), water (liquid) stored (stored) in the suppression pool 152 may flow into the triangular corner 160b, and the water level (position of the water surface 104) flowing into the triangle pool 160b. There is a need for a measurement technique. However, when the water level is measured at the landing 164 of the triangular corner 160b, the gap 166 of the staircase 162 is about 5 cm and is extremely narrow, so that it is difficult to measure with a measuring device using ultrasonic waves. For this reason, adoption of a displacement sensor using light (laser) has been studied, but when the transparency of the stored water is high, most of the light passes through the water surface and is reflected at the bottom of the facility. There was a problem that it was difficult to accurately grasp the water level (liquid level).

  Therefore, in the liquid level measurement method according to the present embodiment, as shown in FIG. 3B, the distance measuring sensor 110 is installed on the handrail of the upper step 164 a, and the bubble generating device 120 is placed on the water surface 104 through the gap 166 of the step 162. Place in the vicinity. The bubble generating device 120 generates bubbles below the water surface near the water surface 104 where the light from the distance measuring sensor 110 is irradiated, and the distance measuring sensor 110 reflects the light to the water surface 104 to measure the distance. To do. This makes it possible to accurately measure the water level in a narrow place even when the transparency of the stored water is high.

  As mentioned above, although preferred embodiment of this invention was described referring an accompanying drawing, it cannot be overemphasized that this invention is not limited to the example which concerns. It will be apparent to those skilled in the art that various changes and modifications can be made within the scope of the claims, and these are naturally within the technical scope of the present invention. Understood.

  The present invention can be used as a liquid level measurement system for measuring the liquid level of a liquid stored in a storage facility.

DESCRIPTION OF SYMBOLS 100 ... Liquid level measurement system, 102 ... Bubble, 104 * 104a * 104b ... Water surface, 106 ... Frame, 108a, 108b ... Wire, 110 ... Ranging sensor, 112 ... Semiconductor laser, 114 ... Projection lens, 116 ... Light reception lens , 118 ... Light receiving element, 120 ... Bubble generator, 130 ... Suspension controller, 122 ... Tube, 124 ... Pump, 150 ... Water storage facility, 152 ... Suppression pool, 154 ... Torus room, 160a to 160d ... Triangular corner, 162 ... Stairs, 164 ... landing, 164a ... upper stairs, 164b ... lower stairs, 166 ... gap

Claims (5)

A distance measuring sensor that reflects light on the liquid surface and measures the distance;
A bubble generating device that generates bubbles below the liquid level at a position irradiated with light from the distance measuring sensor;
With
The bubble generating device is suspended from above and disposed below the liquid level, and generates the bubbles in the vicinity of the liquid level. A wire for suspending the bubble generating device;
A suspension control device that detects whether or not the bubble generating device is disposed below the liquid surface by tension of the wire and adjusts the length of the wire;
The liquid level measurement system according to claim 1, further comprising:   The liquid level measurement system according to claim 1, wherein the bubble generator generates nitrogen bubbles.   The liquid level measurement system according to claim 1, wherein the distance measuring sensor is a triangular distance measuring method or a pulse distance measuring method. A distance measuring sensor that reflects light on the liquid surface and measures the distance;
Using a bubble generator that generates bubbles in the liquid,
The bubble generating device is suspended from above and placed below the liquid level,
A liquid level measuring method, wherein bubbles are generated by the bubble generating device in the vicinity of a liquid surface at a position irradiated with light from the distance measuring sensor.

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