Water level measurement system

Abstract

A water level measurement system according to one embodiment of the present invention includes a support pipe installed in a water tank filled with a fluid whose level is to be measured and extending in a depth direction of the water tank; a support rod located in an internal space of the support pipe and extending in a depth direction of the water 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 water tank, wherein the water level calculator calculates the water level of the water tank using the order of the ultrasonic probes located at the highest position among the plurality of ultrasonic probes that detect signals of reflected waves reflected from the support pipe.

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 refueling water tank or the nuclear fuel storage water tank of a nuclear power plant is monitored, and a safety response system and procedures therefor must be provided. That is, cooling is performed against decay heat in the nuclear fuel refueling water tank or the nuclear fuel storage water tank, and forced cooling by a pump or the like is performed. At this time, in the case of the nuclear fuel storage water tank, if the cooling function is lost or forced circulation or the like 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 rapid fluctuations 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 interference fringes of ultrasonic waves. The ultrasonic water level measurement method has a deep correlation 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 refueling 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 stereotyped 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 Initiative] [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 includes a water tank filled with a fluid whose water level is to be measured, a support pipe extending along the depth direction of the water tank, a support rod located in the internal space 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 of the water tank, wherein the water level calculator calculates the water level of the water tank using the order of the ultrasonic probes located at the highest position among the plurality of ultrasonic probes that detect reflected wave signals reflected from the support pipe.

[0007] When N is the number of the plurality of ultrasonic probes, L is the length of the support rod, and S is the order of the ultrasonic probes that detected the reflected wave signal and were positioned at the highest position, the water level in the tank can be calculated as (L / N)*S. The support rod may be located on the central axis of the support pipe.

[0008] The support rod may be positioned on one side with respect to the central axis 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 plurality of ultrasonic probes may be arranged along the depth direction of the water tank.

[0011] The tank may include a nuclear fuel reloading tank or a nuclear fuel storage tank for a nuclear power plant. [Effects of the Invention]

[0012] 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.

[0013] Furthermore, because this invention allows for the measurement of the water level of a fluid filling a tank using an ultrasonic probe, which is low-cost equipment, it is possible to measure the water level quickly and at a lower cost compared to methods that use expensive radar-based equipment. [Brief explanation of the drawing]

[0014] [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 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. [Figure 3] This diagram schematically shows a water level measuring system according to another embodiment installed inside a water tank. [Figure 4] This is a partially enlarged view of a water level measurement system according to another embodiment, illustrating the state in which ultrasonic waves propagate above and below the water surface. [Modes for carrying out the invention]

[0015] Hereinafter, with reference to the attached drawings, various embodiments of the present invention will be described in detail so that a person with ordinary skill in the art to which the present invention pertains can easily implement them. The present invention can be realized in a variety of different forms and is not limited to the embodiments described herein.

[0016] To clearly explain the present invention, unnecessary explanatory parts have been omitted, and the same or similar reference numerals are used throughout the specification for identical or similar components.

[0017] Furthermore, the dimensions and thicknesses of each component shown in the drawings are arbitrary for the sake of explanation, and therefore the present invention is not necessarily limited to those shown.

[0018] Figure 1 is a schematic diagram showing a water level measurement system according to one embodiment installed in a water tank, and Figure 2 is a partially enlarged view of the water level measurement system according to one embodiment, illustrating the state in which ultrasonic waves propagate above and below the water surface.

[0019] As shown in Figures 1 and 2, a water level measurement system according to one 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.

[0020] The support pipe 100 is installed inside a water tank 10 filled with a fluid 1 whose water level is to be measured. The support pipe 100 extends along the depth direction Y of the water tank 10 and may have a predetermined length L. The lower part of the support pipe 100 may be located below the water surface 1a of the fluid 1 filling the water tank 10, and the upper part may be located above the water surface 1a of the fluid 1. Thus, the internal space O of the support pipe 100 is filled with fluid 1. Such a support pipe 100 is made of a material such as metal. The water tank 10 may include a nuclear fuel reloading tank or a nuclear fuel storage tank of a nuclear power plant. Thus, the present invention can monitor the water level of the cooling water filling the inside of a water tank 10 of a nuclear power plant. However, the present invention is not necessarily limited thereto and is applicable to a variety of water tanks.

[0021] 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 the central axis C of the support pipe 100 and 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. 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 spaced apart from the inner wall of the support pipe 100 by a predetermined distance D and be located on the central axis C 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.

[0022] The plurality of ultrasonic probes 300 can be attached to the circumferential surface of the support rod 200 to generate ultrasonic waves 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 from 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.

[0023] The plurality of ultrasonic probes 300 are arranged at a predetermined interval along the depth direction Y of the water tank 10.

[0024] Such ultrasonic probes 300 are provided at the same height and can include a plurality of sub - ultrasonic probes 310, 320 that are separated from each other. Therefore, ultrasonic waves can be generated in various directions of the support rod 200, so that the water level can be measured more accurately. In this embodiment, two sub - ultrasonic probes are shown, but it is not necessarily limited to this, and various numbers of sub - ultrasonic probes can be used.

[0025] In this case, the support rod 200, which is filled inside, may not be in direct contact with the inner wall of the support pipe 100, and may be structured to be separated from each other. Therefore, the ultrasonic vibrations generated by the multiple probes 300 attached to the support rod 200 will not directly affect the support pipe 100 which is separated from the support rod 200, and ultrasonic interference and other issues can be eliminated, allowing for more accurate measurement of the water level.

[0026] 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.

[0027] The ultrasonic waves L1 generated from 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. The reflected waves R then travel back to the ultrasonic transducer 300, allowing the ultrasonic transducer 300 to detect the reflected waves.

[0028] Furthermore, the ultrasonic waves L2 generated from the ultrasonic transducer 300 located above the water surface 1a do not travel through the fluid 1, so they are either annihilated or scattered by the inner wall of the support pipe 100, and the ultrasonic transducer 300 cannot detect the reflected waves R.

[0029] 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 using the order of the ultrasonic probes located at the highest position among the ultrasonic probes 300 that have detected the reflected wave R signal reflected from the support pipe 100.

[0030] At this time, among the ultrasonic transducers 300 that detected the reflected wave R signal, the ultrasonic transducer 300 positioned at the highest position can be confirmed by comparing its position with that of the ultrasonic transducers 300 that detected the reflected wave signal using an AND logic gate.

[0031] Each ultrasonic transducer 300 can act as a channel for measuring the water level. The AND logic gate of the water level calculator 400 compares the channels between adjacent ultrasonic transducers 300. At this time, as the water level rises one step at a time, the signal of the final reflected wave R detected by the ultrasonic transducer 300 can be confirmed by comparing the channels with each other. Therefore, the comparison is carried up to the ultrasonic transducer 300 that detects the final reflected wave signal, i.e., the channel, and by confirming the signal of the highest reflected wave detected last, the water level of the tank 10 can be calculated. In Figure 1, the AND logic gate of the water level calculator 400 is used to detect signals up to the 8th reflected wave R8, so the order of the ultrasonic transducer 300 located at the highest position among the multiple ultrasonic transducers 300 that detected the reflected wave R signal can be calculated as 8.

[0032] 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 positioned at the highest position among the 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. Here, the order of the ultrasonic probes 300 refers to the order calculated from the lower end of the support rod 200. [Formula 1] P = (L / N) * S In this case, each ultrasonic probe 300 can act as a channel for measuring the water level. That is, 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 mount 100 ultrasonic probes 300 on a support rod 200 that is 6 m long, and position one ultrasonic probe 300 every 6 cm.

[0033] Furthermore, if we intend to measure the water level in a water tank 10 with a water level of 4m using 150 channels, we can mount 150 ultrasonic probes 300 on a support rod 200 that is 4m long, so that one ultrasonic probe 300 is positioned every 2.67cm.

[0034] If the channel at the highest position among the channels in which the reflected wave signal is detected is 123, that is, if the order of the ultrasonic transducers 300 at the highest position among the multiple ultrasonic transducers 300 that detected the reflected wave signal is 123, then the water level P in tank 10 is calculated as (400cm / 150)*123=328.41cm.

[0035] Furthermore, by increasing the number of channels, or the number of ultrasonic probes 300, the water level can be measured more precisely.

[0036] 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.

[0037] 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.

[0038] Multiple fixing members 500 can connect the support rod 200 and the inner wall of the support pipe 100 to each other, thereby fixing the support rod 200 inside the support pipe 100. Such fixing members 500 can be positioned between vertically adjacent ultrasonic probes 300. Therefore, the swinging of the support rod 200 can be prevented, allowing for more accurate water level measurement by the ultrasonic probe 300.

[0039] On the other hand, in the above embodiment, the support rod is located on the central axis of the support pipe, but other embodiments are also possible in which the support rod is located on one side with respect to the central axis of the support pipe.

[0040] A water level measuring system according to another embodiment of the present invention will be described in detail below with reference to Figures 3 and 4.

[0041] Figure 3 is a schematic diagram showing a water level measurement system according to another embodiment installed in a water tank, and Figure 4 is a partially enlarged view of the water level measurement system according to another embodiment, illustrating the state in which ultrasonic waves propagate above and below the water surface.

[0042] Other embodiments shown in Figures 3 and 4 are substantially identical to the embodiment shown in Figures 1 and 2, except for the position of the support rods; therefore, repeated explanations will be omitted.

[0043] As shown in Figures 3 and 4, a water level measuring system according to another embodiment of the present invention 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. The support rod 200 is located on one side of the support pipe 100 with respect to its central axis C and can extend along the depth direction Y. The support rod 200 can be located on one side of the support pipe 100 in contact with its inner wall.

[0044] 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.

[0045] 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.

[0046] 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 using the order of the ultrasonic probes 300 that are positioned at the highest position among the ultrasonic probes 300 that have detected the reflected wave R signal reflected from the support pipe 100.

[0047] At this time, among the ultrasonic transducers 300 that detected the reflected wave R signal, the ultrasonic transducer 300 positioned at the highest position can be confirmed by comparing its position with that of the ultrasonic transducers 300 that detected the reflected wave signal using an AND logic gate.

[0048] Each ultrasonic transducer 300 can act as a channel for measuring the water level. The AND logic gate of the water level calculator 400 compares the channels between adjacent ultrasonic transducers 300. At this time, as the water level rises one step at a time, the signal of the final reflected wave R detected by the ultrasonic transducer 300 can be confirmed by comparing the channels with each other. Therefore, the comparison is carried up to the ultrasonic transducer 300 that detects the final reflected wave signal, i.e., the channel, and by confirming the signal of the highest reflected wave detected last, the water level of the tank 10 can be calculated. In Figure 3, the AND logic gate of the water level calculator 400 is used to detect up to the signal of the 12th reflected wave R12, so the order of the ultrasonic transducer 300 located at the highest position among the multiple ultrasonic transducers 300 that detected the reflected wave R signal can be calculated as 12.

[0049] When attempting to measure the water level in a water tank 10 with a water level of 4m using 150 channels, 150 ultrasonic probes 300 can be mounted on a 4m long support rod 200, with one ultrasonic probe 300 positioned every 2.67cm.

[0050] If the channel at the highest position among the channels in which the reflected wave signal is detected is 12, that is, if the order of the ultrasonic transducers 300 at the highest position among the multiple ultrasonic transducers 300 that detected the reflected wave signal is 12, then the water level P of the tank 10 is calculated as (400cm / 150)*12=32cm.

[0051] 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.

[0052] Although the present invention 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 in the internal space 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, The plurality of ultrasonic probes are connected to a water level calculator that calculates the water level in the water tank, The water level calculator uses the order of the ultrasonic probes positioned at the highest position among the plurality of ultrasonic probes that detect the reflected wave signals reflected from the support pipe to calculate the water level in the tank. The support rod is located on the central axis of the support pipe, Each of the ultrasonic probes includes a plurality of sub-ultrasonic probes provided at the same height on the outer wall of the support rod and spaced apart from each other. The support rod and the support pipe do not come into direct contact with each other. Each of the sub-ultrasonic probes generates ultrasonic waves, and if fluid is present, the generated ultrasonic waves travel through the fluid toward the inner wall of the support pipe, generating reflected waves at the inner wall, and the sub-ultrasonic probes detect the reflected waves. Water level measurement system.

2. The water level measuring system according to claim 1, wherein when the number of the plurality of ultrasonic probes is N, the length of the support rod is L, and the order of the ultrasonic probes that detected the reflected wave signal, the ultrasonic probes positioned at the highest position are S, the water level in the water tank is calculated as (L / N) * S.

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 plurality of ultrasonic probes are arranged along the depth direction of the water tank.

5. 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.

Images