Water level measurement system

Abstract

A water level measurement system according to one embodiment of the present invention is installed in a tank filled with a fluid whose water level is to be measured, and includes: a support pipe extending in a depth direction of the tank; a support rod located on one side of a central axis of the support pipe and extending in a depth direction of the tank; a plurality of ultrasonic probes attached to the support rod and generating ultrasonic waves; and a water level calculator connected to the plurality of ultrasonic probes and calculating the water level of the tank.

Description

Technical Field

[0001] The present invention relates to a water level measurement system, and more particularly to a water level measurement system using ultrasonic waves.

Background Art

[0002] Generally, the water level of the cooling water filled inside the nuclear fuel reloading water tank or the nuclear fuel storage water tank of a nuclear power plant is monitored, and a safety response system and procedures must be provided accordingly. That is, cooling is performed against decay heat in the nuclear fuel reloading water tank or the nuclear fuel storage water tank, and forced cooling by a pump is performed. At this time, in the case of the nuclear fuel storage water tank, if the cooling function is lost or forced circulation is not performed, boiling may occur in the nuclear fuel storage water tank, and a situation where steam is mixed may occur. At this time, the water level must be monitored so that an alternative water source can be mobilized immediately, and even after the incorporation of the alternative water source, the state must be monitored by continuously monitoring the water level.

[0003] Generally, a differential pressure type water level measurement method or an ultrasonic water level measurement method is used to measure the water level. In the differential pressure type water level measurement method, when bubbles or steam are generated inside the water tank, it becomes difficult to measure the water level by differential pressure due to the rapid fluctuation of the fluid. The ultrasonic water level measurement method calculates the time between the ultrasonic wave emitted from a dense medium such as a liquid and the reflected ultrasonic wave, or measures the water level using an interference fringe of the ultrasonic wave. The ultrasonic water level measurement method is deeply correlated with the presence of the reflected wave that exits after the ultrasonic wave is transmitted through a dense medium and reflected. However, when the conditions are not normal, that is, when the cooling function of the nuclear fuel reloading water tank or the nuclear fuel storage water tank is lost, boiling occurs in the cooling water, and bubbles or steam are rapidly generated, the reflected wave disappears or is lost, making it difficult to calculate the standardized reflected wave. Therefore, it is difficult to accurately measure the reflected wave and there is a limit to measuring the water level. In particular, when bubbles are generated, the waveform of the ultrasonic wave is not uniform, making it difficult to measure the accurate water level.

[0004] To complement these water level measurement methods, methods such as thermal contact radar, thermal diffusion radar, or methods that measure water levels by mimicking the shape of a radar are used. However, these methods involve the integration of complex modules or equipment for analysis and interpretation, and the installation of machines to analyze radar data increases the price and cost of the equipment itself. [Overview of the project] [Problems that the invention aims to solve]

[0005] This embodiment relates to a water level measuring system that can accurately measure water levels even under abnormal conditions. [Means for solving the problem]

[0006] A water level measuring system according to one embodiment is provided in a water tank filled with a fluid whose water level is to be measured, and includes a support pipe extending along the depth direction of the water tank, a support rod located on one side with respect to the central axis of the support pipe and extending along the depth direction of the water tank, a plurality of ultrasonic probes attached to the support rod that generate ultrasonic waves, and a water level calculator connected to the plurality of ultrasonic probes that calculates the water level in the water tank.

[0007] The support rod can come into contact with the inner wall of the support pipe.

[0008] The ultrasonic probe is positioned opposite the exposed inner wall of the support pipe.

[0009] The plurality of ultrasonic probes can propagate the ultrasonic waves in a horizontal direction parallel to the surface of the fluid.

[0010] The water level calculator can calculate the water level in the tank using the number of ultrasonic probes that detected the reflected wave signal reflected by the support pipe from among the plurality of ultrasonic probes.

[0011] When N is the number of the plurality of ultrasonic probes, L is the length of the support rod, and S is the number of ultrasonic probes that detected the reflected wave signal, the water level in the tank is calculated as (L / N)*S.

[0012] The plurality of ultrasonic probes are arranged along the depth direction of the water tank.

[0013] The system may further include a fixing member for securing the ultrasonic probe to the support rod.

[0014] The tank may include a nuclear fuel reloading tank or a nuclear fuel storage tank for a nuclear power plant. [Effects of the Invention]

[0015] According to one embodiment, since the ultrasonic waves travel between the support rod and the inner wall of the support pipe, where no bubbles or steam are generated, the water level can be accurately measured even under abnormal conditions where bubbles or steam are generated inside the tank.

[0016] Furthermore, because it is possible to measure the water level of the fluid filling the tank using low-cost ultrasonic probes, the water level can be measured quickly and at a lower cost compared to methods using expensive radar-based equipment. [Brief explanation of the drawing]

[0017] [Figure 1] This diagram schematically shows a water level measurement system according to one embodiment installed inside a water tank. [Figure 2] This is a partial perspective view of a water level measurement system according to one embodiment. [Figure 3] This is a plan view of a water level measurement system according to one embodiment. [Figure 4] This is a partially enlarged view of a water level measurement system according to one embodiment, illustrating the state in which ultrasonic waves propagate above and below the water surface. [Modes for carrying out the invention]

[0018] Hereinafter, for the understanding of the present invention, various embodiments of the present invention will be described in detail so that those having ordinary knowledge in the technical field to which the present invention pertains can easily implement them with reference to the attached drawings. The present invention can be realized in various different forms and is not limited to the embodiments described herein.

[0019] For the sake of clarity in the description of the present invention, parts that are unnecessary for the description are omitted, and the same reference numerals are assigned to the same or similar components throughout the specification.

[0020] In addition, the size and thickness of each component shown in the drawings are arbitrarily shown for convenience of explanation, and the present invention is not necessarily limited to what is shown in the drawings.

[0021] FIG. 1 is a diagram schematically showing a state in which a water level measurement system according to an embodiment is provided in a water tank, FIG. 2 is a partial perspective view of a water level measurement system according to an embodiment, and FIG. 3 is a plan view of a water level measurement system according to an embodiment.

[0022] As shown in FIG. 1, a water level measurement system according to an embodiment includes a support pipe 100, a support rod 200, a plurality of ultrasonic probes 300, a water level calculator 400, and a plurality of fixing members 500.

[0023] The support pipe 100 is provided in a water tank 10 filled with a fluid 1 for measuring the water level. The support pipe 100 extends long along the depth direction Y of the water tank 10 and can have a predetermined length L. The lower part of the support pipe 100 is located below the water surface 1a of the fluid 1 filled in the water tank 10, and the upper part can be located above the water surface 1a of the fluid 1. Therefore, the internal space O of the support pipe 100 is filled with the fluid 1. Such a support pipe 100 is made of a substance such as metal. The water tank 10 can include a nuclear fuel reloading water tank or a nuclear fuel storage water tank of a nuclear power plant. Therefore, the present invention can monitor the water level of the cooling water filled inside the water tank 10 of a nuclear power plant. However, the present invention is not necessarily limited to this and is applicable to various water tanks.

[0024] The support rod 200 can be located in the internal space O of the support pipe 100. The support rod 200 can be located on one side with respect to the central axis C of the support pipe 100 and can extend along the depth direction Y. The length L of the support rod 200 may be the same as the length L of the support pipe 100. However, it is not necessarily limited to this, and according to the embodiment, the length L of the support rod 200 may be different from the length L of the support pipe 100. The support rod 200 can be in contact with the inner wall of the support pipe 100 and located on one side of the support pipe 100. Therefore, the fluid 1 can be located in the narrow internal space O between the inner wall of the support pipe 100 and the support rod 200. Therefore, even under abnormal conditions where boiling occurs in the water tank 10 and bubbles or steam are generated, it is difficult for bubbles or steam to exist in the fluid 1 located in the narrow space between the inner wall of the support pipe 100 and the support rod 200.

[0025] The plurality of ultrasonic probes 300 can be attached to the circumferential surface of the support rod 200 to generate ultrasonic waves L1, L2 and detect the reflected wave R. And the plurality of ultrasonic probes 300 can make the ultrasonic waves travel in the horizontal direction X parallel to the water surface 1a of the fluid 1. Therefore, the ultrasonic waves generated by the plurality of ultrasonic probes 300 can travel to the inner wall of the support pipe 100. At this time, since it is difficult for bubbles or steam to exist on the path of the ultrasonic waves, accurate water level measurement is possible.

[0026] The plurality of ultrasonic probes 300 are arranged at a predetermined interval along the depth direction Y of the water tank 10.

[0027] Such ultrasonic probes 300 are provided on the circumferential surface of the support rod 200 at a position facing the exposed inner wall of the support pipe 100. Therefore, ultrasonic waves can be generated in one direction from the support rod 200.

[0028] In this case, the inner walls of the support pipe 100 opposite the side walls of the support rod 200 to which the multiple ultrasonic probes 300 are attached may not be in direct contact with each other, but rather separated. Therefore, the ultrasonic vibrations generated by the multiple probes 300 attached to the support rod 200 will not directly affect the support pipe 100 that is separated from the support rod 200, eliminating ultrasonic interference and allowing for more accurate measurement of the water level.

[0029] In other words, the ultrasonic probe 300 is attached to a support rod 200 that is filled and fixed inside, and ultrasonic waves are transmitted to the support pipe 100 that does not directly contact the ultrasonic probe 300. As a result, the ultrasonic waves between the ultrasonic probes 300 do not interfere with each other, and no interference signals or unwanted signals are generated. Therefore, complex additional equipment such as a processing unit for processing interference signals or unwanted signals is not required, and since each ultrasonic probe 300 measures the water level independently, a simple structure is possible, and manufacturing costs can be minimized.

[0030] Figure 4 is a partially enlarged view of a water level measurement system according to one embodiment, illustrating the state in which ultrasonic waves propagate above and below the water surface.

[0031] As shown in Figure 4, the ultrasonic waves L1 generated by the ultrasonic transducer 300 located below the water surface 1a travel through the fluid 1, generating reflected waves at the inner wall of the support pipe 100. These reflected waves R travel back to the ultrasonic transducer 300, allowing the ultrasonic transducer 300 to detect the reflected waves.

[0032] Furthermore, since the ultrasonic waves L2 generated by the ultrasonic probe 300 located on the water surface 1a do not travel through the fluid 1, they are destroyed or scattered by the inner wall of the support pipe 100, and the ultrasonic probe 300 cannot detect the reflected waves R.

[0033] The water level calculator 400 is connected to multiple ultrasonic probes 300 and can calculate the water level of the tank 10. The water level calculator 400 can calculate the water level of the tank 10 by summing up the number of ultrasonic probes 300 that detected the reflected wave R signal reflected by the support pipe 100.

[0034] In other words, when N is the number of ultrasonic probes 300, L is the length of the support rod 200 (or support pipe 100), and S is the number of ultrasonic probes 300 that detected the reflected wave R signal, the water level (P) of the water tank 10 can be expressed by the following formula 1. [Formula 1] P = (L / N) * S In this case, each ultrasonic probe 300 can act as a channel for measuring the water level. In other words, if we want to measure the water level in a water tank 10 filled with fluid 1 having a water level of 6 m using 100 channels, we can attach 100 ultrasonic probes 300 to a support rod 200 that is 6 m long, and position one ultrasonic probe 300 every 6 cm.

[0035] Furthermore, if we want to measure the water level in a tank 10 with a water level of 4m using 150 channels, we can place 150 ultrasonic transducers 300 on a support rod 200 that is 4m long, so that one ultrasonic transducer 300 is positioned every 2.67cm. In this case, if there are 123 channels in which the reflected wave R signal is detected, the number of ultrasonic transducers 300 that detected the reflected wave R signal (S) will be 123. Therefore, since the total number of ultrasonic transducers 300 (N) is 150 and the length L of the support rod 200 is 400cm, the water level (P) in the tank 10 is calculated as (400cm / 150)*123 = 328.41cm.

[0036] Furthermore, by increasing the number of channels, that is, the number of ultrasonic probes 300, the water level in the tank 10 can be measured more precisely.

[0037] Thus, in this embodiment of the present invention, the water level measuring system travels between the support rod 200 and the inner wall of the support pipe 100, where no bubbles or steam are generated, allowing for more accurate measurement of the water level of the fluid 1 filling the water tank 10.

[0038] Furthermore, since the water level of the fluid 1 filling the tank 10 can be measured using the low-cost ultrasonic probe 300, the water level can be measured quickly and at a lower cost compared to methods using expensive radar-based equipment.

[0039] Multiple fixing members 500 can be used to fix multiple ultrasonic probes 300 to the support rod 200. The fixing members 500 may include a first fixing member 510 and a second fixing member 520 that are provided in contact with the upper and lower surfaces of the ultrasonic probes 300, respectively. Since the oscillation of the ultrasonic probes 300 can be prevented by using such first fixing members 510 and second fixing members 520, water level measurement by the ultrasonic probes 300 can be performed more accurately.

[0040] Although the present disclosure has been described above through preferred embodiments, it will be readily apparent to those engaged in the art to which the present invention pertains that the present invention is not limited thereto, and that a variety of modifications and variations are possible, as long as they do not deviate from the scope of the claims described below.

Claims

1. A support pipe is installed in a water tank filled with a fluid for measuring the water level, and extends along the depth direction of the water tank. A solid support rod is located on one side with respect to the central axis of the support pipe and extends along the depth direction of the water tank, Multiple ultrasonic probes that attach to the outer wall of the support rod and generate ultrasonic waves, A water level calculator connected to the plurality of ultrasonic probes for calculating the water level in the water tank, Includes, The ultrasonic probe is positioned opposite the exposed inner wall of the support pipe, The fluid whose water level is to be measured is located in the space between the inner wall of the support pipe and the support rod. The ultrasonic waves generated by the ultrasonic probe, if fluid is present, travel through the fluid towards the inner wall of the support pipe, generating reflected waves at the inner wall, and the ultrasonic probe detects these reflected waves. Water level measurement system.

2. The water level measuring system according to claim 1, wherein the outer wall of the support rod is in contact with the inner wall of the support pipe along the depth direction of the water tank.

3. The water level measuring system according to claim 1, wherein the plurality of ultrasonic probes propagate the ultrasonic waves in a horizontal direction parallel to the surface of the fluid.

4. The water level measuring system according to claim 1, wherein the water level calculator calculates the water level of the water tank using the number of ultrasonic probes among the plurality of ultrasonic probes that detected the signal of the reflected wave reflected by the support pipe.

5. The water level measuring system according to claim 4, wherein when the number of the plurality of ultrasonic probes is N, the length of the support rod is L, and the number of ultrasonic probes that detected the reflected wave signal is S, the water level in the water tank is calculated as (L / N) * S.

6. The water level measuring system according to claim 1, wherein the plurality of ultrasonic probes are arranged along the depth direction of the water tank.

7. The water level measuring system according to claim 1, further comprising a fixing member for fixing the ultrasonic probe to the support rod.

8. The water level measuring system according to claim 1, wherein the water tank includes a nuclear fuel reloading tank or a nuclear fuel storage tank of a nuclear power plant.

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