Water level measuring system

Abstract

A water level measuring system according to an embodiment of the present application includes a support pipe installed in a water tank filled with a fluid of which a water level is to be measured and extending in a depth direction of the water tank, a support rod located in an inner space of the support pipe and extending in the 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 attached to the support rod and calculating a water level in the water tank, wherein the water level calculator calculates the water level in the water tank by using an order of an ultrasonic probe of the plurality of ultrasonic probes detecting a signal of a reflected wave reflected from the support pipe, which is in a highest position.

Description

Technical Field

[0001] This invention relates to a water level measurement system, and more specifically, to a water level measurement system utilizing ultrasonic waves. Background Technology

[0002] Typically, the water level of the cooling water filling the nuclear fuel reloading tanks or nuclear fuel storage tanks in nuclear power plants is monitored, and corresponding safety response systems and procedures are prepared. That is, in the case of nuclear fuel reloading tanks or nuclear fuel storage tanks, a cooling process is performed to dissipate decay heat, and forced cooling is achieved through pumps. In the case of nuclear fuel storage tanks, if the cooling function is lost or forced circulation is not implemented, the fuel tank may boil, and steam may mix. In this situation, the water level must be monitored so that an alternative water source can be immediately mobilized, and even after the alternative water source is supplied, its status must be monitored through continuous water level monitoring.

[0003] Water levels are typically measured using either differential pressure or ultrasonic methods. In differential pressure methods, the rapid fluctuations in fluid flow when bubbles or steam are generated inside the tank make it difficult to measure the water level by pressure difference. Ultrasonic methods measure water level by calculating the time between the emitted ultrasonic wave and its reflection in a dense medium such as a liquid, or by using the interference fringes of the ultrasonic waves. Ultrasonic water level measurements are highly dependent on the presence of reflected waves after the ultrasonic waves have traveled through the dense medium. When conditions are abnormal, such as when the cooling function of a nuclear fuel reloading tank or storage vessel is lost, boiling occurs in the cooling water, rapidly generating bubbles or steam. Because the reflected waves disappear or are lost, it is difficult to calculate the normalized reflected waves. Therefore, it is difficult to accurately measure the reflected waves, and there are limitations to water level measurement. In particular, when bubbles are generated, the non-uniform waveform of the ultrasonic waves makes accurate water level measurement difficult.

[0004] To complement these water level measurement methods, thermal contact radar, thermal diffusion radar, or methods that mimic the shape of radar are used to measure water levels. However, in these methods, complex modules or equipment for analysis and interpretation are combined, and equipment for analyzing radar-type data must be installed, thus increasing the price and cost of the equipment itself. Summary of the Invention

[0005] Technical issues

[0006] This embodiment relates to a water level measurement system that can accurately measure water levels even under abnormal conditions.

[0007] Technical solution

[0008] The water level measurement system according to an embodiment includes: a support tube installed in a water tank filled with fluid for which the water level is to be measured and extending in the depth direction of the water tank; a support rod disposed in the internal space of the support tube and extending in the depth direction of the water tank; a plurality of ultrasonic detectors attached to the support rod and generating ultrasonic waves; and a water level calculator connected to the plurality of ultrasonic detectors and calculating the water level in the water tank, wherein the water level calculator calculates the water level in the water tank by using the order of the ultrasonic detectors positioned at the highest position among the plurality of ultrasonic detectors that detect signals of reflected waves reflected from the support tube.

[0009] When the number of ultrasonic detectors is N, the length of the support rod is L, and the order of the ultrasonic detectors that detect the reflected wave signal at the highest position is S, the water level in the tank can be calculated as (L / N)*S.

[0010] The support rod can be set on the central axis of the support tube.

[0011] The support rod can be set on one side of the support tube based on the central axis of the support tube.

[0012] Multiple ultrasonic detectors can propagate ultrasonic waves in a horizontal direction parallel to the surface of the fluid.

[0013] Multiple ultrasonic detectors can be positioned along the depth of the water tank.

[0014] The tank may include a nuclear fuel refill tank or a nuclear fuel storage tank for a nuclear power plant.

[0015] Beneficial effects

[0016] According to the embodiment, since the ultrasonic waves propagate in the space between the support rod and the inner wall of the support tube without generating bubbles or steam, the water level can be accurately measured even in abnormal conditions where bubbles or steam are generated inside the water tank.

[0017] Furthermore, since the water level of the fluid filling the tank can be measured using an ultrasonic detector, which is a low-cost device, the water level can be measured quickly and at a low cost compared to methods using expensive radar-type equipment. Attached Figure Description

[0018] Figure 1 This is a schematic diagram showing the state in which the water level measurement system according to an embodiment is installed in a water tank.

[0019] Figure 2 This is a partial enlarged view of the water level measurement system according to an embodiment, and a diagram showing the propagation of ultrasonic waves above and below the water surface.

[0020] Figure 3 This is a schematic diagram showing the state of a water level measuring system installed in a water tank according to another embodiment.

[0021] Figure 4 This is a partial enlarged view of a water level measurement system according to another embodiment, and is an accompanying drawing showing the propagation of ultrasonic waves above and below the water surface. Detailed Implementation

[0022] In the following description, various embodiments of the invention will be detailed to aid in understanding the invention and to enable those skilled in the art to readily implement the invention with reference to the accompanying drawings. The invention can be implemented in many different forms and is not limited to the embodiments described herein.

[0023] To clearly illustrate the invention, irrelevant parts have been omitted, and the same or similar constituent elements are given the same reference numerals throughout the specification.

[0024] Furthermore, since the dimensions and thicknesses of each structure shown in the accompanying drawings are arbitrarily illustrated for better understanding and ease of description, the present invention is not necessarily limited to the contents shown in the drawings.

[0025] Figure 1 This is a schematic diagram showing the state in which the water level measurement system according to an embodiment is installed in a water tank. Figure 2 This is a partial enlarged view of the water level measurement system according to an embodiment, and a diagram showing the propagation of ultrasonic waves above and below the water surface.

[0026] like Figure 1 and Figure 2 As shown, the water level measurement system according to the embodiment includes a support pipe 100, a support rod 200, a plurality of ultrasonic detectors 300, a water level calculator 400, and a plurality of fixing components 500.

[0027] A support pipe 100 can be installed inside a water tank 10 filled with fluid 1 whose water level is to be measured. The support pipe 100 can extend relatively long in the depth direction Y of the water tank 10 and can have a predetermined length L. The support pipe 100 can have a lower portion positioned below the water surface 1a of the fluid 1 inside the water tank 10 and an upper portion positioned above the water surface 1a of the fluid 1. Therefore, fluid 1 can fill the internal space O of the support pipe 100. The support pipe 100 can be made of a material such as metal. The water tank 10 can include a nuclear fuel reloading tank or nuclear fuel storage tank of a nuclear power plant. Therefore, the present invention can monitor the water level of cooling water filled in the water tank 10 of a nuclear power plant. However, the present invention is not necessarily limited to this and can be applied to various water tanks.

[0028] The support rod 200 can be disposed within the internal space O of the support tube 100. The support rod 200 can be disposed on the central axis C of the support tube 100 and can extend in the depth direction Y. The length L of the support rod 200 can be the same as the length L of the support tube 100. However, it is not necessarily limited to this, and according to embodiments, the length L of the support rod 200 can be different from the length L of the support tube 100. The support rod 200 can be spaced apart from the inner wall of the support tube 100 by a predetermined distance D and disposed on the central axis C of the support tube 100. Therefore, the fluid 1 can be disposed in the narrow space between the inner wall of the support tube 100 and the support rod 200. Therefore, even in abnormal conditions where boiling occurs in the water tank 10 and bubbles or steam are generated, bubbles or steam are unlikely to exist in the fluid 1 disposed in the narrow space between the inner wall of the support tube 100 and the support rod 200.

[0029] Multiple ultrasonic detectors 300 can be attached to the circumferential surface of the support rod 200 to generate ultrasonic waves and detect reflected waves R. Furthermore, the multiple ultrasonic detectors 300 can propagate ultrasonic waves in a horizontal direction X parallel to the surface 1a of the fluid 1. Therefore, the ultrasonic waves generated by the multiple ultrasonic detectors 300 can propagate to the inner wall of the support tube 100. At this time, since bubbles or steam are difficult to exist in the path of the ultrasonic waves, the water level can be accurately measured.

[0030] Multiple ultrasonic detectors 300 can be spaced apart at predetermined gaps in the depth direction Y of the water tank 10.

[0031] The ultrasonic detector 300 may include multiple sub-ultrasonic detectors 310 and 320 mounted at the same height and spaced apart from each other. Therefore, since ultrasonic waves can be generated in various directions of the support rod 200, water level can be measured more accurately. Although two sub-ultrasonic detectors are shown in this embodiment, it is not a limitation, and the number of sub-ultrasonic detectors can be varied.

[0032] At this point, the support rod 200 filling the interior does not directly contact the inner wall of the support tube 100, and the support rod 200 and the support tube 100 can be spaced apart from each other. Therefore, the vibration of ultrasonic waves generated by the multiple ultrasonic detectors 300 attached to the support rod 200 does not directly affect the support tube 100 spaced apart from the support rod 200, thereby eliminating ultrasonic interference and thus measuring the water level more accurately.

[0033] In other words, since the ultrasonic detector 300 is attached to a fixed support rod 200 inside the filling to transmit ultrasonic waves to the support tube 100 which does not directly contact the ultrasonic detector 300, the ultrasonic waves between the ultrasonic detectors 300 do not interfere with each other, thus preventing the generation of interference or noise signals. Therefore, since complex additional equipment such as arithmetic processing devices for processing interference or noise signals is not required, and each ultrasonic detector 300 independently measures the water level, a simple structure can be achieved and manufacturing costs can be minimized.

[0034] Since the ultrasonic wave L1 generated by the ultrasonic detector 300 located below the water surface 1a propagates inside the fluid 1, a reflected wave is generated on the inner wall of the support tube 100. Since the reflected wave R returns to the ultrasonic detector 300, the ultrasonic detector 300 can detect the reflected wave.

[0035] Furthermore, since the ultrasonic wave L2 generated by the ultrasonic detector 300 positioned above the water surface 1a does not propagate inside the fluid 1, it dissipates or scatters on the inner wall of the support tube 100, thus the ultrasonic detector 300 cannot detect the reflected wave R.

[0036] The water level calculator 400 can be connected to multiple ultrasonic detectors 300 to calculate the water level of the water tank 10. The water level calculator 400 can calculate the water level of the water tank 10 by using the sequence of ultrasonic detectors 300 positioned at the highest point to detect the signal of the reflected wave R reflected from the support pipe 100.

[0037] At this time, the ultrasonic detector 300, which is set at the highest position in the ultrasonic detector 300 that detects the signal of the reflected wave R, can be compared and confirmed by an AND logic gate.

[0038] Each ultrasonic detector 300 can function as a channel for measuring water level. The AND logic gate of the water level calculator 400 can compare the channels between adjacent ultrasonic detectors 300. As the water level rises progressively, the signal of the final reflected wave in the reflected wave R detected by the ultrasonic detector 300 can be confirmed by comparing the channels. Therefore, the water level in tank 10 can be calculated by comparing the ultrasonic detectors 300, i.e., the channels that detected the final reflected wave signal, and confirming the signal of the reflected wave at the highest position. Figure 1 In this process, since the signal of the eighth reflected wave R8 is detected by using the AND logic gate of the water level calculator 400, the order of the ultrasonic detector 300 set at the highest position among the multiple ultrasonic detectors 300 that detect the signal of the reflected wave R can be calculated as eight.

[0039] When the number of ultrasonic detectors 300 is N, the length of the support rod 200 (or support tube 100) is L, and the order of the ultrasonic detector 300 at the highest position among the multiple ultrasonic detectors 300 detecting the reflected wave R is S, the water level P of the water tank 10 can be expressed by the following Equation 1. Here, the order of the ultrasonic detectors 300 refers to the order calculated from the lower end of the support rod 200.

[0040] [Equation 1]

[0041] P = (L / N) * S

[0042] At this time, each ultrasonic detector 300 can function as a channel for measuring water level. That is, when 100 channels in a water tank 10 filled with fluid 1 at a water level of 6m are used to measure water level, 100 ultrasonic detectors 300 can be installed on a support rod 200 with a length of 6m, and one ultrasonic detector 300 can be set every 6cm.

[0043] In addition, when the water level is to be measured using 150 channels in the water tank 10 with a water level of 4m, 150 ultrasonic detectors 300 can be installed on the support rod 200 with a length of 4m, and one ultrasonic detector 300 can be set every 2.67cm.

[0044] When the channel set at the highest position in the channel that detects the reflected wave signal is 123, that is, when the ultrasonic detector set at the highest position in the ultrasonic detector 300 that detects the reflected wave signal is 123, the water level P of the water tank 10 can be calculated as (400cm / 150)*123=328.41em.

[0045] Furthermore, by increasing the number of channels, i.e. the number of ultrasonic detectors 300, the water level in the water tank 10 can be measured more accurately.

[0046] As described above, in the water level measurement system according to an embodiment of the present invention, ultrasonic waves propagate between the support rod 200 and the inner wall of the support tube 100 (which is a space where no bubbles or steam are generated), thereby enabling more accurate measurement of the water level of the fluid 1 filled inside the water tank 10.

[0047] Furthermore, since the water level of the fluid 1 filled in the water tank 10 can be measured using an ultrasonic detector 300, which is a low-cost device, the water level can be measured quickly and at low cost compared to the method of using expensive radar-type equipment.

[0048] Multiple fixing components 500 can be used to fix the support rod 200 inside the support tube 100 by connecting the inner wall of the support rod 200 to the support tube 100. The fixing components 500 can be arranged between adjacent ultrasonic detectors 300. Therefore, the swaying of the support rod 200 can be prevented, and the water level can be measured more accurately by the ultrasonic detector 300.

[0049] On the other hand, in the above embodiment, the support rod is disposed on the central axis of the support tube, but in another embodiment, the support rod may also be disposed on one side of the support tube based on the central axis of the support tube.

[0050] In the following text, reference will be made to Figure 3 and Figure 4 A water level measurement system according to another embodiment of the present invention is described in detail.

[0051] Figure 3 This is a schematic diagram showing the state of a water level measuring system installed in a water tank according to another embodiment. Figure 4 This is a partial enlarged view of a water level measurement system according to another embodiment, and is a diagram showing the propagation of ultrasonic waves above and below the water surface.

[0052] Apart from the position of the support rod Figure 3 and Figure 4 Another embodiment shown is similar to Figure 1 and Figure 2 The embodiments shown are essentially the same, and repeated descriptions are omitted.

[0053] like Figure 3 and 4 As shown, a water level measurement system according to another embodiment includes a support pipe 100, a support rod 200, a plurality of ultrasonic detectors 300, a water level calculator 400, and a plurality of fixing components 500. The support rod 200 can be disposed on one side of the support pipe 100 based on the central axis C of the support pipe 100 and can extend in the depth direction Y. The support rod 200 can contact the inner wall of the support pipe 100 and is disposed on one side of the support pipe 100.

[0054] At this point, the sidewalls of the support rod 200 to which the multiple ultrasonic detectors 300 are attached do not directly contact the inner walls of the support tube 100 facing each other and can have a structure that is separate from each other. Therefore, the vibrations of the ultrasonic waves generated by the multiple ultrasonic detectors 300 attached to the support rod 200 do not directly affect the support tube 100 which is spaced apart from the support rod 200, thereby eliminating ultrasonic interference and thus measuring the water level more accurately.

[0055] In other words, since the ultrasonic detector 300 is attached to a fixed support rod 200 inside the filling to transmit ultrasonic waves to the support tube 100 which does not directly contact the ultrasonic detector 300, the ultrasonic waves between the ultrasonic detectors 300 do not interfere with each other, thus preventing the generation of interference or noise signals. Therefore, since complex additional equipment such as arithmetic processing devices for processing interference or noise signals is not required, and each ultrasonic detector 300 independently measures the water level, a simple structure can be achieved and manufacturing costs can be minimized.

[0056] The water level calculator 400 can be connected to multiple ultrasonic detectors 300 to calculate the water level of the water tank 10. The water level calculator 400 can calculate the water level of the water tank 10 by using the sequence of ultrasonic detectors 300 positioned at the highest point among those that detect the signal of the reflected wave R reflected from the support pipe 100.

[0057] At this time, the ultrasonic detector 300, which is set at the highest position in the ultrasonic detector 300 that detects the signal of the reflected wave R, can be compared and confirmed by an AND logic gate.

[0058] Each ultrasonic detector 300 can function as a channel for measuring water level. The AND logic gate of the water level calculator 400 can compare the channels between adjacent ultrasonic detectors 300. As the water level rises progressively, the signal of the final reflected wave in the reflected wave R detected by the ultrasonic detectors 300 can be confirmed by comparing the channels. Therefore, the water level of the tank 10 can be calculated by comparing the ultrasonic detectors 300, i.e., the channels that detected the final reflected wave signal, and confirming the signal of the reflected wave at the highest position. Figure 3 In this process, since the signal of the twelfth reflected wave R12 is detected by using the AND logic gate of the water level calculator 400, the order of the ultrasonic detector 300 set at the highest position among the multiple ultrasonic detectors 300 that detect the signal of the reflected wave R can be calculated as twelfth.

[0059] When the water level needs to be measured using 150 channels in a water tank 10 with a water level of 4m, 150 ultrasonic detectors 300 can be installed on a support rod 200 with a length of 4m, and one ultrasonic detector 300 can be set every 2.67cm.

[0060] When the channel that detects the reflected wave signal is 12, that is, when the ultrasonic detector 300 that detects the reflected wave signal is 12 in the order of the ultrasonic detector 300 that detects the reflected wave signal at the highest position, the water level P of the water tank 10 can be calculated as (400cm / 150)*12=32cm.

[0061] Multiple fixing members 500 can secure multiple ultrasonic detectors 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 in contact with and respectively mounted on the upper and lower surfaces of the ultrasonic detectors 300. Since the ultrasonic detectors 300 can be prevented from shaking by using the first fixing member 510 and the second fixing member 520, the water level can be measured more accurately by the ultrasonic detectors 300.

[0062] Although the invention has been described with reference to the preferred embodiments above, those skilled in the art will understand that the invention is not limited thereto, and various modifications and variations can be made without departing from the scope of the appended claims.

Claims

1. A water level measurement system, comprising: A support tube is installed in a water tank filled with fluid for measuring the water level and extends in the depth direction of the water tank. A support rod is disposed within the internal space of the support tube and extends in the depth direction of the water tank; Multiple ultrasonic detectors are attached to the sidewall of the support rod and generate ultrasonic waves. as well as A water level calculator, connected to the plurality of ultrasonic detectors, calculates the water level in the water tank. The water level calculator calculates the water level in the tank by using the order of the ultrasonic detectors positioned at the highest point among a plurality of ultrasonic detectors that detect signals of reflected waves reflected from the support pipe. The plurality of ultrasonic detectors propagate ultrasonic waves in a horizontal direction parallel to the surface of the fluid. The ultrasonic waves propagate between the support rod and the inner wall of the support tube and are reflected on the inner wall of the support tube. The side wall of the support rod to which the plurality of ultrasonic detectors are attached does not directly contact the inner wall of the support tube.

2. The water level measurement system according to claim 1, wherein, When the number of the plurality of ultrasonic detectors is N, the length of the support rod is L, and the order of the ultrasonic detector located at the highest position among the plurality of ultrasonic detectors that detect the reflected wave signal is S, the water level of the water tank is calculated as (L / N)*S.

3. The water level measurement system according to claim 1, wherein, The support rod is mounted on the central axis of the support tube.

4. The water level measurement system according to claim 1, wherein, The support rod is positioned on one side of the support tube based on the central axis of the support tube.

5. The water level measurement system according to claim 1, wherein, The plurality of ultrasonic detectors are positioned along the depth direction of the water tank.

6. The water level measurement system according to claim 1, wherein, The tank includes a nuclear fuel refill tank or a nuclear fuel storage tank for a nuclear power plant.

7. The water level measurement system according to claim 3, wherein, The support rod and the support tube do not come into direct contact with each other.

8. The water level measurement system according to claim 4, wherein, The ultrasonic detector is installed at a position facing the exposed inner wall of the support tube.

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