Heat-thermal water level gauge

Abstract

To provide a thermo water gauge also serving as a reliable temperature gauge.SOLUTION: A thermo water gauge 10A includes: a plurality of first temperature sensors 11n (n=1 to 5) arranged separately in the direction of a water depth; a heater 15 for discharging a thermal energy around the first temperature sensors 11n (n=1 to 5); a cylindrical body 16A (16) in which the first temperature sensors 11n (n=1 to 5) and the heater 15 are arranged in the inside where the water level is as high as in the outside; and a second temperature sensor 12n (n=1 to 5) arranged in the outer peripheral surface of the cylindrical body 16A.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] An embodiment of the present invention relates to a heat-thermo type water level gauge that also functions as a thermometer. [Background technology]

[0002] Heat-thermo water level gauges are used as water level gauges installed in the fuel pools of nuclear power plants. These heat-thermo water level gauges have a thermometer and a heater, and use the difference in heat transfer between air and water to distinguish between air and water from the difference in temperature rise of the thermometer when the heater is turned on. For this reason, when the heater is turned on, the temperature signal from the thermometer does not accurately reflect the water temperature in the fuel pool. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 6998279 Summary of the Invention [Problem to be solved by the invention]

[0004] As such, with conventional heat-thermo water level gauges, turning on the heater causes the water temperature in the vicinity to rise, making it impossible to measure water level and water temperature simultaneously. Therefore, in order to measure water level and water temperature simultaneously, a thermometer must be installed separately from the heat-thermo water level gauge. However, to ensure the reliability of water temperature measurements, the separately installed thermometer must be separated to eliminate the influence of heat generated by the heater, which creates the problem of increasing the size of the device.

[0005] The embodiments of the present invention have been made in consideration of the above circumstances, and an object of the present invention is to provide a small heat-thermo water level gauge that also functions as a highly reliable thermometer. [Means for solving the problem]

[0006] The heat-thermal water level gauge of the embodiment comprises a plurality of first temperature sensors spaced apart in the water depth direction, a heater that emits thermal energy around the first temperature sensors, a cylindrical body in which the first temperature sensors and the heater are arranged on the inside to maintain the same water level as on the outside, and a second temperature sensor arranged on the outer surface of the cylindrical body. [Effects of the Invention]

[0007] An object of the present invention is to provide a compact heat-thermo water level gauge that also functions as a highly reliable thermometer. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a ZX vertical cross-sectional view showing the concept of a heat-thermo type water level meter according to a first embodiment of the present invention, and a block diagram of its control unit. [Figure 2] 1 is an XY horizontal cross-sectional view of a heat-thermo type water level meter according to a first embodiment. [Figure 3] FIG. 5 is a ZX vertical cross-sectional view showing the concept of a heat-thermo type water level meter according to a second embodiment of the present invention. [Figure 4] FIG. 10 is an XY horizontal cross-sectional view of a heat-thermo type water level meter according to a second embodiment. [Figure 5] FIG. 10 is a ZX vertical cross-sectional view showing the concept of a heat-thermo type water level meter according to a third embodiment of the present invention. [Figure 6] FIG. 10 is an XY horizontal cross-sectional view of a heat-thermo type water level meter according to a third embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] (First embodiment) Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. Fig. 1 is a ZX vertical cross-sectional view showing the concept of a heat-thermal water level meter 10A (10) according to a first embodiment of the present invention, and a block diagram of its control unit 20. Fig. 2 is an XY horizontal cross-sectional view of the heat-thermal water level meter 10A (10).

[0010] In this way, the heat-thermal water level meter 10A has a plurality of first temperature sensors 11 arranged at intervals in the water depth direction (Z-axis direction). n (n=1 to 5) and these first temperature sensors 11 n A heater 15 that emits thermal energy around the (n=1 to 5) and a first temperature sensor 11 inside that keeps the water level the same as the outside. n (n=1 to 5), a cylindrical body 16A (16) in which the heater 15 is arranged, and a second temperature sensor 12 arranged on the outer circumferential surface of the cylindrical body 16A. n (n=1-5) and

[0011] As shown in Fig. 1, the heater 15 is configured from a pair of wires with high electrical resistance along the water depth direction (Z-axis direction) from the first temperature sensor 111 at the bottom to the first temperature sensor 115 at the top, as shown in cross-section in Fig. 2. The pair of wires is sealed in a sealed tube filled with magnesium oxide, which has high thermal conductivity. When electricity is applied to the heater 15, thermal energy generated by Joule heat is released to the outside via the liquid phase 31 and the gas phase 32.

[0012] In the drawing, the heater 15 is connected to a plurality of first temperature sensors 11. n In this example, two wires are arranged as a pair over the entire length of the first temperature sensors 11 (n=1 to 5) in the depth direction. However, the heater 15 to be applied is not limited to this. n It is also possible to arrange a plurality of pairs of wires each corresponding to each of (n=1 to 5).

[0013] A plurality of first temperature sensors 11 n (n=1 to 5) varies in thermal diffusivity of thermal energy depending on whether the surroundings are in the gas phase 32 or the liquid phase 31, and therefore the output value after the heater 15 is energized varies. n When the first temperature sensor 11 is exposed to the gas phase 32, the thermal energy supplied from the heater 15 does not diffuse into the gas phase 32, which has a small thermal diffusivity, and therefore the output value of the first temperature sensor 11 increases significantly. nWhen the heater 15 is immersed in the liquid phase 31, the thermal energy supplied from the heater 15 is diffused into the liquid phase 31, which has a large thermal diffusivity, and therefore the output value does not increase very much.

[0014] The cylindrical body 16A (16) is configured so that when it is immersed in the liquid phase 31 contained in the container 30, the outside and inside thereof maintain the same water level 17. That is, the cylindrical body 16A (16) has openings at the bottom and top ends in the depth direction, and is configured so that even if the water level 17 of the liquid phase 31 in the container 30 changes, the water level 17 inside it follows.

[0015] The partition wall forming the cylindrical body 16A (16) separates the liquid phase 31 contained in the container 30 into the inside and outside of the cylindrical body 16A. Therefore, the thermal energy emitted by the heater 15 inside the cylindrical body 16A (16) is retained inside the cylindrical body 16A (16) and is prevented from leaking to the outside. Therefore, the second temperature sensor 12 disposed on the outer circumferential surface of the cylindrical body 16A (16) n (n=1 to 5) is not affected by the thermal energy emitted by the heater 15 and can accurately detect the temperature (water temperature) of the liquid phase 31 outside it.

[0016] The material of the partition wall of the cylindrical body 16A that separates the liquid phase 31 into an inside and an outside may be metal, glass, resin, etc., but is not particularly limited, and a material with a small heat transfer coefficient is preferable. The horizontal cross section of the cylindrical body 16A is also exemplified as being cylindrical, but is not limited to this and can be any shape, such as rectangular or elliptical.

[0017] First temperature sensor 11 n (n=1 to 5) and the second temperature sensor 12 n (n=1 to 5) all have a common configuration, in which a thermocouple wire is housed in a sheath tube with a closed tip. This sheath tube is filled with magnesium oxide as an insulating material along with the wire. In a thermocouple, wires of different metals are welded at the tip, and the ambient temperature of this tip is measured based on the thermoelectromotive force detected at the opposite end.

[0018] As shown in FIG. 2, the first temperature sensor 11 n The second temperature sensors 12 (n=1 to 5) are arranged concentrically around the heater 15 in the XY horizontal cross section. n The first temperature sensor 11 (n=1 to 5) is also arranged concentrically around the outer periphery of the cylindrical body 16A (16) in the XY horizontal cross section. n (n=1 to 5) and the second temperature sensor 12 n The arrangement of (n=1 to 5) is not particularly limited.

[0019] Also, the second temperature sensor 12 n (n=1 to 5) are arranged in the longitudinal direction of the cylindrical body 16, and the first temperature sensor 11 n (n=1 to 5), and a plurality of them are arranged with the same height. As a result, the temperatures of the liquid phase 31 and the gas phase 32 contained in the container 30 and the first temperature sensor 11 n Furthermore, it is also possible to examine the temperature distribution in the depth direction of the liquid phase 31 and the gas phase 32. However, the present invention is not limited to such a configuration, and the second temperature sensor 12 n (n=1 to 5) are the first temperature sensors 11 n (n=1 to 5) There is no need to match the height of each, and there is no need to match the number either; for example, just one is fine.

[0020] Returning to FIG. 1, the explanation will be continued. The control unit 20 of the heat-thermal water level gauge includes an electric current supply unit 25 that supplies electric current to the heater 15 to cause it to emit thermal energy, and a plurality of first temperature sensors 11. n a first receiving unit 21 that receives temperature signals from the first temperature sensors 11 (n=1 to 5) after emitting thermal energy; n a water level determination unit 26 that determines the water level 17 based on the amount of change in the temperature signal from a plurality of second temperature sensors 12 (n=1 to 5); n (n=1 to 5), and the second temperature sensor 12 receives the temperature signal regardless of whether or not the heater 15 is emitting thermal energy. n and a temperature determination unit 27 that determines the temperature (water temperature) of the liquid phase 31 based on the temperature signals (n=1 to 5).

[0021] Based on an operator's command, the power supply unit 25 passes current through the heater 15 to generate Joule heat and release a certain amount of thermal energy into the surrounding area. The magnitude and duration of the current passed through the heater 15 can be set in advance and are controlled by the water level determination unit 26.

[0022] Each of the first receiving unit 21 and the second receiving unit 22 receives a plurality of first temperature sensors 11. n (n=1 to 5) and a plurality of second temperature sensors 12 n Each of the first receiving unit 21 and the second receiving unit 22 receives the temperature signal in real time, regardless of the operation of the power supply unit 25 (n=1 to 5).

[0023] First temperature sensor 11 n (n=1 to 5) and the second temperature sensor 12 n Each of the heaters (n=1 to 5) constantly outputs a voltage on the order of mV as a temperature signal. The Joule heat generated by passing a current through the heater 15 has different thermal diffusivities depending on whether the surroundings are in the gas phase 32 or the liquid phase 31, which causes differences in the voltage output (temperature signal).

[0024] Each of the first receiving unit 21 and the second receiving unit 22 is connected to the first temperature sensor 11. n and the second temperature sensor 12 n The weak voltage output from the temperature sensor 21 is converted into a temperature signal at a voltage level that can be processed by an analog circuit and output to the water level determination unit 26.

[0025] The water level determination unit 26 determines the temperature of the corresponding first temperature sensor 11 based on the amount of change in the temperature signal after the heater 15 releases thermal energy. n (n=1 to 5) is identified as being in the liquid phase 31 or the gas phase 32. Specifically, if the amount of change in the temperature signal is smaller than a specified value, the corresponding first temperature sensor 11 is in the liquid phase 31, and if it is larger than a specified value, the corresponding first temperature sensor 11 is in the gas phase 32. n The water level determination unit 26 then determines that the two first temperature sensors 11 are located at positions where the discrimination result of the liquid phase 31 and the gas phase 32 is switched. nIt is determined that there is a water level of 17 between them.

[0026] On the other hand, the temperature determination unit 27 determines the temperature of the position determined to be the liquid phase 31 based on the temperature signal received by the second receiving unit 22, regardless of whether thermal energy is being released to the heater 15. It can also determine the temperature of the position determined to be the gas phase 32.

[0027] (Second embodiment) Next, a second embodiment of the present invention will be described with reference to Figs. 3 and 4. Fig. 3 is a ZX vertical cross-sectional view showing the concept of a heat-thermal water level gauge 10B (10) according to the second embodiment of the present invention. Fig. 4 is an XY horizontal cross-sectional view of a heat-thermal water level gauge 10B (10) according to the second embodiment. The heat-thermal water level gauge 10B of the second embodiment differs from the heat-thermal water level gauge 10A of the first embodiment described above in that the structure of the cylindrical body 16B (16) is different. In Figs. 3 and 4, parts having the same structure or function as those in Figs. 1 and 2 are designated by the same reference numerals, and duplicated explanations will be omitted.

[0028] In the heat-thermo type water level gauge 10B of the second embodiment, the partition wall separating the outside and inside of the cylindrical body 16B has a hollow structure 35. By having the partition wall of the cylindrical body 16B have a hollow structure 35 sealed by a double wall in this way, the heat insulating effect between the inside and outside of the cylindrical body 16B is improved, and the second temperature sensor 12 arranged on the outside n (n=1 to 5) can detect the temperature of the liquid phase 31 or the gas phase 32 more accurately without being affected by the thermal energy emitted by the heater 15 inside.

[0029] The hollow structure 35 of the partition wall of the cylindrical body 16B is decompressed and sealed to create a vacuum, which further improves the heat insulating effect and allows the second temperature sensor 12 n (n=1 to 5), the temperature of the liquid phase 31 or the gas phase 32 can be detected more accurately. In the cylindrical body 16B in the second embodiment, the partition wall has a hollow structure 35 sealed by a double wall, which improves the heat insulating effect between the inside and outside of the cylindrical body 16, so there is no need to limit the material of the partition wall as much as in the cylindrical body 16A in the first embodiment.

[0030] (Third embodiment) Next, a third embodiment of the present invention will be described with reference to Figs. 5 and 6. Fig. 5 is a ZX vertical cross-sectional view showing the concept of a heat-thermal water level gauge 10C (10) according to the third embodiment of the present invention. Fig. 6 is an XY horizontal cross-sectional view of a heat-thermal water level gauge 10C (10) according to the third embodiment. The heat-thermal water level gauge 10C of the third embodiment differs from the heat-thermal water level gauges 10A and 10B of the first and second embodiments described above in that the structure of the cylindrical body 16C (16) is different. In Figs. 5 and 6, parts having the same structure or function as those in Figs. 1 and 2 are designated by the same reference numerals, and duplicated explanations will be omitted.

[0031] In the heat-thermo water level gauge 10C of the third embodiment, the cylindrical body 16C is provided with an inlet 36 and an outlet 37 for a medium 38 to circulate in the hollow structure 35 of the partition. In this way, the medium 38 introduced from the inlet 36 circulates in the water depth direction and circumferential direction of the hollow structure 35 of the cylindrical body 16C and is discharged from the outlet 37. As a result, the thermal energy released by the heater 15 inside the cylindrical body 16C is discharged to the outside together with the medium 38.

[0032] As a result, the second temperature sensor 12 n (n=1 to 5), the thermal energy of the heater 15 is prevented from reaching the liquid phase 31 or the gas phase 32, and the temperature can be detected more accurately. Note that, since the cylindrical body 16C in the third embodiment improves the heat insulating effect by circulating the medium 38 in the hollow structure 35, it is not necessary to limit the material of the partition wall as much as in the cylindrical body 16A in the first embodiment. The circulated medium 38 can also be a liquid or a gas.

[0033] The heat-thermo water level gauge 10 according to each embodiment can be inserted into a small-diameter pipe and measure the water level and temperature inside simultaneously. That is, by having the configuration described in each embodiment, the cylindrical body 16 prevents the thermal energy of the heater 15 from being transmitted to the second temperature sensor 12. As a result, even if the distance between the second temperature sensor 12 and the heater 15 is short, the second temperature sensor 12 can accurately detect the temperature of the liquid phase 31 or the gas phase 32 without being affected by the thermal energy emitted by the heater 15. That is, because the cross-sectional area of ​​the heat-thermo water level gauge 10 in the X-Y horizontal cross section can be reduced, the heat-thermo water level gauge 10 can be inserted into a small-diameter pipe and measure the water level and temperature inside simultaneously.

[0034] According to at least one embodiment of the heat-thermal water level gauge described above, a first temperature sensor and heater are arranged inside the cylindrical body, and a second temperature sensor is arranged on its outer surface, thereby providing a small heat-thermal water level gauge that also serves as a highly reliable thermometer.

[0035] Although several embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, substitutions, modifications, and combinations can be made without departing from the spirit of the invention. These embodiments and their modifications are included within the scope and spirit of the invention, as well as the inventions described in the claims and their equivalents. [Explanation of symbols]

[0036] 10 (10A, 10B, 10C)...Heat thermo type water level gauge, 11...First temperature sensor, 12...Second temperature sensor, 15...Heater, 16 (16A, 16B, 16C)...Cylindrical body, 17...Water level, 20...Control unit, 21...First receiving unit, 22...Second receiving unit, 25...Electrification unit, 26...Water level determination unit, 27...Temperature determination unit, 30...Containing body, 31...Liquid phase, 32...Gas phase, 35...Hollow structure, 36...Inlet, 37...Outlet, 38...Gaseous medium.

Claims

1. a plurality of first temperature sensors arranged at intervals in a water depth direction; a heater that emits thermal energy around the first temperature sensor; a cylindrical body in which the first temperature sensor and the heater are arranged and whose inside maintains the same water level as the outside; A heat-thermo type water level gauge comprising: a second temperature sensor arranged on the outer peripheral surface of the cylindrical body.

2. The heat-thermo type water level meter according to claim 1, The cylindrical body is a heat-thermo type water level gauge in which the partition wall separating the outside and the inside has a hollow structure.

3. The heat-thermo type water level meter according to claim 2, The hollow structure of the partition is a heat-thermo type water level gauge in which the hollow structure is sealed under reduced pressure or in which a medium is circulated.

4. The heat-thermo type water level meter according to any one of claims 1 to 3, A heat thermostatic water level gauge in which a plurality of second temperature sensors are arranged in the water depth direction of the cylindrical body.

5. The heat-thermo type water level meter according to any one of claims 1 to 3, an electric current supply unit that supplies current to the heater to cause the heater to emit the thermal energy; a first receiving unit that receives temperature signals from the plurality of first temperature sensors; a water level determination unit that determines the water level based on the amount of change in the temperature signals of the plurality of first temperature sensors after the thermal energy is released; a second receiving unit that receives temperature signals from the plurality of second temperature sensors; A heat thermostatic water level meter comprising: a temperature determination unit that determines the temperature of the water or gas outside the cylindrical body based on the temperature signal received from the second temperature sensor, regardless of whether the thermal energy is being released to the heater.

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