Thermocouple reference junction compensation device and method for assembling a thermocouple reference junction compensation device

Abstract

To enable stable temperature measurement of a target area.SOLUTION: A thermocouple reference junction compensation device is provided, comprising a heat equalizing block configured to accommodate a thermocouple reference junction, a main body with one open end designed to accommodate the heat equalizing block, a heat insulation material provided between the main body and the heat equalizing block, and a lid designed to close the one open end of the main body and fixed to the main body to suppress movement of the heat insulation material in the main body.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a thermocouple reference junction compensation device and a method for assembling a thermocouple reference junction compensation device. [Background technology]

[0002] In the reactor containment vessel, a thermocouple reference junction compensator box is installed as a device for measuring the temperature of the measurement target, which holds a thermocouple hot junction that measures the temperature at the target position and a resistance thermometer that measures the temperature at the reference junction. In Patent Document 1, in order to suppress the occurrence of environmental differences between the resistance thermometer and each hot junction, a heat insulating material is provided outside the area where the reference junction and the resistance thermometer are located, thereby suppressing temperature fluctuations inside the thermocouple reference junction compensator box. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 4995113 Summary of the Invention [Problem to be solved by the invention]

[0004] The thermocouple reference junction compensator box is equipped with heat insulating material to suppress fluctuations in the internal atmosphere. If the environment around the reference junction of the thermocouple reference junction compensator box becomes uneven, the temperature inside the box will change locally, reducing the accuracy of temperature measurement.

[0005] The present disclosure has been made in consideration of the above-mentioned problems, and aims to provide a thermocouple reference junction compensation device and a method for assembling a thermocouple reference junction compensation device that can maintain temperature detection accuracy. [Means for solving the problem]

[0006] In order to achieve the above-mentioned object, the thermocouple reference junction compensation device of the present disclosure includes a heat equalizing block that houses a thermocouple reference junction, a main body that houses the heat equalizing block and has one open side, an insulating material arranged between the main body and the heat equalizing block, and a lid that covers the one side of the main body, is fixed to the main body, and suppresses movement of the insulating material within the main body.

[0007] In order to achieve the above object, the thermocouple reference junction compensation device of the present disclosure includes a heat equalizing block that houses a thermocouple reference junction, a main body that houses the heat equalizing block and has one open side, and a heat insulating material arranged between the main body and the heat equalizing block, and the heat insulating material is fixed to the main body with an adhesive.

[0008] In order to achieve the above-mentioned object, the method for assembling a thermocouple reference junction compensation device according to the present disclosure includes the steps of placing a heat equalizing block to which the reference junction of the thermocouple is fixed in the internal space of the main body, placing an insulating material between the main body and the heat equalizing block, and fixing the insulating material to the main body by closing one open side of the main body with a lid.

[0009] To achieve the above object, the disclosed method for assembling a thermocouple reference junction compensation box includes the steps of placing a heat equalizing block to which the reference junction of the thermocouple is fixed in the internal space of the main body, applying adhesive to the outer peripheral surface of the heat insulating material, and placing the heat insulating material between the main body and the heat equalizing block and fixing the heat insulating material to the main body with the adhesive. [Effects of the Invention]

[0010] According to the present disclosure, it is possible to maintain high accuracy in temperature measurement. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 1 is a cross-sectional view showing a thermocouple reference junction compensation device. [Figure 2] FIG. 2 is a perspective view of a thermocouple reference junction compensation box. [Figure 3] Figure 3 is a schematic diagram of the top surface of the thermocouple reference junction compensation box. [Figure 4] FIG. 4 is a schematic diagram showing the front side of the lid portion. [Figure 5] FIG. 5 is a schematic diagram showing the back side of the lid. [Figure 6] FIG. 6 is a schematic perspective view of a heat insulating material. [Figure 7] FIG. 7 is a flowchart showing the assembly process of the thermocouple reference junction compensation box. DETAILED DESCRIPTION OF THE INVENTION

[0012] Preferred embodiments of the present disclosure will be described in detail below with reference to the drawings. However, the present disclosure is not limited to these embodiments. Furthermore, the components in the following embodiments include those that are replaceable and easy for those skilled in the art, or those that are substantially identical. Furthermore, the components in the embodiments described below can be variously omitted, replaced, or modified without departing from the spirit of the present invention. Furthermore, when there are multiple embodiments, the present disclosure also includes those configured by combining the respective embodiments.

[0013] FIG. 1 is a cross-sectional view showing a thermocouple reference junction compensation device. The thermocouple reference junction compensation device 10 has a housing 12, a thermocouple reference junction compensation box 40, a cold junction compensator 24, and a resistance temperature detector 30. The thermocouple reference junction compensation box 40 is also referred to as the compensation box 40 for short. The housing 12 houses the thermocouple reference junction compensation box 40 inside and is fixed to the facility. The thermocouple reference junction compensation box 40 houses the cold junction compensator 24 and the resistance temperature detector 30 inside.

[0014] The housing 12 has a box portion 13, a lid portion 16, bolts 18, and nuts 19. The box portion 13 is a box that is open on the upper side in the vertical direction. The box portion 13 is fixed to the wall of the facility or plant where it is installed by bolts, welding, or the like. The box portion 13 is formed of, for example, stainless steel. Note that in this embodiment, the open side of the box portion 13, i.e., the side on which the lid portion 16 is arranged, is the upper side in the vertical direction, but the orientation of the housing 12 is not limited to this. The open side (one side, open side) of the box portion 13 of the housing 12 may be arranged in a direction other than the upper vertical direction, for example, a side that opens horizontally or a side that opens obliquely.

[0015] The box portion 13 has a flange portion 14 formed at its upper end. Bolt holes 15 are formed in the flange portion 14. The flange portion 14 is formed along the outer periphery of the housing 12. The flange portion 14 is formed to protrude radially outward. The flange portion 14 has a thickness. The flange portion 14 has bolt holes 15, through which bolts 18 pass, formed at predetermined intervals along the circumferential direction. Here, the radial direction refers to a direction intersecting a central axis CL that passes through the center of the housing 12 and penetrates the lid portion 16 and the bottom portion 20. A direction moving away from the central axis CL from a certain position is referred to as a radially outward direction, and a direction moving closer to the central axis CL from a certain position is referred to as a radially inward direction. The direction along the central axis CL is referred to as an axial direction, and a direction surrounding the central axis CL (a direction around the central axis CL) is referred to as a circumferential direction. Terminals (connectors) 21 that connect cables 26a, 26b, and 32 of the cold junction compensator 24 and the resistance temperature detector 30 are fixed to the bottom surface 20 of the box portion 13. The portion of the bottom surface 20 of the box portion 13 into which the terminals 21 are inserted is sealed by the terminals 21.

[0016] The lid 16 is a plate-shaped member that covers the open upper surface of the box 13 in the vertical direction. The lid 16 is made of, for example, stainless steel. The lid 16 has bolt holes 17 formed in positions corresponding to the bolt holes 15 in the flange 14 of the box 13.

[0017] Bolt 18 is inserted into bolt hole 15 and bolt hole 17. Nut 19 is fastened to bolt 18 inserted through bolt holes 15 and 17. By fastening lid portion 16 and box portion 13 of housing 12 with bolt 18 and nut 19, the internal space is closed by lid portion 16.

[0018] For each thermocouple installed on the measurement target, the hot junction is located at the measurement position, and the reference junction 28 is located inside the compensation box 40. The cold junction compensator 24 has cables 26a and 26b connected to the reference junction 28. The cold junction compensator 24 is connected to the thermocouple via cable 26a. The cold junction compensator 24 forms a circuit with cable 26b and a control unit connected to cable 26b, and the control unit measures the current flowing due to the temperature difference between the reference junction and the measurement position, thereby measuring the temperature at the measurement position. Cable 26b is made of, for example, copper and is covered with insulating resin.

[0019] The resistance temperature detector 30 is inserted into the compensation box 40 and connected to the control unit via a cable 32. The resistance temperature detector 30 measures the temperature inside the compensation box 40, i.e., the temperature of the reference junction 28 of the cold junction compensator 24. The control unit calculates the temperature of the reference junction 28 from the measurement result of the resistance temperature detector 30, and calculates the temperature at the measurement position from the information on the temperature of the reference junction 28 and the information on the temperatures of the hot junctions of each thermocouple installed in the object to be measured. Three resistance temperature detectors 30 are inserted. However, the number of resistance temperature detectors 30 is not limited to three.

[0020] The thermocouple reference junction compensation box 40 will be described using Fig. 2 to Fig. 5. Fig. 2 is a perspective view of the thermocouple reference junction compensation box. Fig. 3 is a schematic diagram of the top surface of the thermocouple reference junction compensation box. Fig. 4 is a schematic diagram showing the front of the lid. Fig. 5 is a schematic diagram showing the back of the lid.

[0021] The thermocouple reference junction compensation box 40 includes a main body 42 , a bolt 46 , a metal block 54 , a lid 60 , a heat insulating material 70 , and adhesives 90 and 92 .

[0022] The main body 42 is a cylindrical structure with a flange 44 joined to its upper end. The main body 42 houses a metal block 54, a heat insulating material 70, and adhesives 90 and 92 in an internal space 48. The main body 42 is made of stainless steel. The lower end of the main body 42 is joined to a bottom surface 50 of the metal block 54, which has a larger outer diameter than the lower end. The main body 42 is fixed by fastening the bottom surface 50 to the bottom 20 of the housing 12 with bolts 52.

[0023] The flange portion 44 is joined along the outer periphery of the upper end of the main body portion 42 and protrudes radially outward from the main body portion 42. In this embodiment, the flange portion 44 has notches 45 formed at predetermined intervals. The notches 45 can accommodate tools, for example. However, the notches 45 do not necessarily have to be formed. The flange portion 44 has bolt holes 47 through which bolts 46 pass.

[0024] The metal block 54 is a heat equalizing block. The metal block 54 is made of solid stainless steel and formed into a cylindrical shape. The metal block 54 is arranged so that the central axis CL of the internal space 48 of the main body 42 and the center of the metal block 54 are coaxial. The metal block 54 has a plurality of accommodating holes 55 into which the cold junction compensator 24 and the resistance temperature detector 30 are inserted. The accommodating holes 55 are each formed to be approximately the same in shape and depth.

[0025] The bottom surface portion 50 has a disk shape that protrudes radially outward from the metal block 54. The bottom surface portion 50 has bolt holes 53, through which bolts 52 pass, provided at predetermined intervals radially outward from the joint portion of the main body portion 42. The bottom surface portion 50 is fixed to the bottom 20 of the housing 12 by the bolts 52. The bottom surface portion 50 may be separate from the metal block 54. In that case, the bottom surface portion 50 is joined to the bottom surface of the metal block 54 that does not have the receiving hole 55 along the circumferential direction.

[0026] The lid portion 60 closes the main body portion 42 with its back surface contacting the upper end surface of the flange portion 44. The lid portion 60 closes the main body portion 42 by being fastened with bolts 46. The lid portion 60 is formed in a disk shape from stainless steel. A lid opening 62 is formed in the lid portion 60. The lid portion 60 has bolt holes 61 formed along the circumferential direction, through which the bolts 46 pass. The lid opening 62 penetrates from the front to the back surface. The lid opening 62 is formed to have a size equivalent to the outer diameter of the portion of the metal block 54 that has the accommodation hole 55. The lid opening 62 allows cables 26a, 26b, and 32 between the cold junction compensator 24 and the resistance thermometer sensor 30 to pass through.

[0027] The gasket 64 is disposed on the surface of the lid portion 60 facing the main body portion 42. The gasket 64 is provided radially outward of the lid opening 62 and inward of the bolt holes 61. The gasket 64 is provided along the circumferential direction. The gasket 64 has a width. It is preferable that the width of the gasket 64 is sufficient to cover the upper surface portion 74 of the thermal insulation material 70.

[0028] The heat insulating material 70 has a cylindrical shape and is disposed between the metal block 54 and the main body portion 42. In this embodiment, three heat insulating materials 70 are stacked in the vertical direction. However, the number of stacked materials is not limited to three. The heat insulating materials 70 are disposed in the internal space 48 with their heights parallel to the axial direction. The heat insulating materials 70 are disposed in three layers, inserted from above the internal space 48 up to the height of the upper surface of the flange portion 44. The heat insulating materials 70 may each have a different height.

[0029] FIG. 6 is a schematic perspective view of the heat insulating material. As described above, the heat insulating material 70 has a cylindrical shape, and the inner peripheral surface 72 faces the metal block 54. In other words, the metal block 54 is disposed in the internal space enclosed by the inner peripheral surface 72. The upper surface 74 and lower surface 76 of the heat insulating material 70 contact the adjacent heat insulating material 70, the lid portion 60, and the bottom portion 50. The outer peripheral surface 78 of the heat insulating material 70 faces the inner peripheral surface of the main body portion 42. The heat insulating material 70 can be a sintered body (ceramic) formed by firing an object formed from fine ceramic powder and a binder. Specifically, the heat insulating material 70 is a sintered body formed mainly from alumina Al2O3 and a binder.

[0030] An adhesive 90 is applied to the surface of the heat insulating material 70 that faces the main body 42, and the heat insulating material 70 is fixed to the main body 42 by the adhesive 90. The adhesive 90 fills the space between the heat insulating material 70 and the main body 42. Adjacent heat insulating materials 70 are also bonded with adhesive 92. The adhesives 90 and 92 can be a mixture of fine ceramic powder and a binder, for example, a mixture of alumina (Al2O3) and a binder. The adhesives 90 and 92 need only be able to bond the heat insulating material 70 and the main body 42 and maintain their performance in the environment in which the compensation box 40 is placed. Here, it is preferable that the adhesives 90 and 92 have a thermal expansion coefficient similar to that of the heat insulating material.

[0031] <Assembly method> Next, a method for assembling the thermocouple reference junction compensation box 40 will be described with reference to Fig. 7. Fig. 7 is a flowchart showing the method for assembling the thermocouple reference junction compensation box.

[0032] The assembly method involves inserting a metal block into the main body (step S12). The metal block 54 is placed in the internal space 48 of the main body 42. In this embodiment, the cold junction compensator 24 and the resistance temperature detector 30 are fixed to the metal block 54 installed in the main body 42. In addition, the cold junction compensator 24 and the resistance temperature detector 30 are connected to the cables 26a, 26b, and 32.

[0033] Next, in the assembly method, adhesive is applied to the insulating material (step S14). For example, adhesives 90 and 92 are applied to two surfaces, the top surface 74 and the outer peripheral surface 78, of the insulating material 70 to be placed in the lowest tier. For the insulating material 70 to be sandwiched between other insulating materials 70, adhesive 90 is applied to the outer peripheral surface 78. For the insulating material 70 to be sandwiched between other insulating materials 70, adhesive 92 may be applied to both surfaces where the insulating materials 70 are bonded. By applying adhesive 92 to both surfaces of the insulating material 70 to be sandwiched between other insulating materials, adhesive can be applied to both surfaces where the insulating material is bonded, for example, the bottom surface 76 of the insulating material 70 in the middle tier and the top surface 74 of the bottom tier. Note that adhesive 92 does not need to be applied to the surface facing the insulating material 70 to which adhesive 92 is applied. For the insulating material 70 in the top tier, adhesives 90 and 92 are applied to two surfaces, the bottom surface 76 and the outer peripheral surface 78.

[0034] Next, the assembly method involves placing the adhesive-coated heat insulating materials one by one between the metal block and the main body (step S16). After applying adhesive 90 to each heat insulating material 70, the heat insulating materials with adhesive 90 applied are inserted one by one between the main body 42 and the metal block 54.

[0035] Next, in the assembly method, the cables 26a, 26b, and 32 are inserted through the lid opening 62 (step S18). Specifically, the cables 26a and 26b of the cold junction compensator 24 and the cable 32 of the resistance temperature detector 30 are inserted through the lid opening 62 together.

[0036] Next, the assembly method involves fastening the lid to the main body to close the inside of the main body with the lid and secure the insulating material (step S20). With the lid 60 secured to the top surface of the main body 42, the insulating material 70 is restricted from moving within the main body 42 (movement in the vertical direction in this embodiment) and its position within the main body 42 is fixed. The insulating material 70 is secured to the main body with adhesive 90 and to adjacent insulating materials 70 with adhesive 92.

[0037] The thermocouple reference junction compensator 10 is provided with a cover 60 to prevent movement of the insulating material 70, thereby preventing the insulating material 70 from moving relative to the main body 42 due to vibrations such as earthquakes. This prevents the insulating material 70 from shifting position or coming loose, which could change the state of heat transfer around the insulating material 70 on the periphery of the metal block 54 and increase the difference in temperature between the contacts of the cold junction compensator 24 and the resistance thermometer sensor. This allows the temperature measurement accuracy to be maintained.

[0038] Furthermore, in the thermocouple reference junction compensation device 10, the insulating material 70 can be fixed to the main body 42 with an adhesive 90 to prevent the insulating material 70 from shifting position or coming loose. The adhesive 90 may be applied only to the outer surface 78. The adhesive 90 may also be applied to the inner surface 80. The adhesive 90 is preferably made of the same material as the insulating material 70, but may also be made of a material whose thermal expansion coefficient is the same as that of the insulating material 70 within a predetermined range. In this way, the insulating material 70 can be fixed without fastening the lid 60 to the main body 42. In other words, the insulating material 70 can be fixed to the main body 42 simply by applying the adhesive 90 to the insulating material 70.

[0039] By providing the gasket 64, it is possible to prevent the heat insulating material 70 arranged in the internal space 48 of the main body 42 from coming into contact with the lid and being damaged.

[0040] In the assembly method of the present embodiment, the metal block 54 is placed in the internal space 48 with the cables 26a, 26b, and 32 connected to the cold junction compensator 24 and the resistance temperature detector 30 fixed to the metal block 54, but this is not limiting. For example, the metal block 54 may be placed in the internal space 48, and then the cables 26a, 26b, and 32 may be connected to the cold junction compensator 24 and the resistance temperature detector 30 fixed to the metal block 54.

[0041] The present disclosure discloses the following inventions, but is not limited to the following.

[0042] (1) A thermocouple reference junction compensation device including: a heat equalizing block that accommodates the reference junction of a thermocouple; a main body that accommodates the heat equalizing block and has one open side; a heat insulating material disposed between the main body and the heat equalizing block; and a lid that covers the one side and is fixed to the main body to suppress movement of the heat insulating material within the main body. According to the present disclosure, the heat insulating material 70 can be fixed while suppressing movement due to vertical vibration.

[0043] (2) The thermocouple reference junction compensation device according to (1), wherein the heat insulating material has a cylindrical shape and is stacked in multiple layers, thereby facilitating the manufacture of the device.

[0044] (3) The thermocouple reference junction compensation device according to (2), wherein the heat insulating material is fixed to the adjacent heat insulating material with an adhesive. According to the present disclosure, movement of the heat insulating material 70 due to vibrations in the vertical and horizontal directions can be suppressed.

[0045] (4) The thermocouple reference junction compensation device according to any one of (1) to (3), wherein the heat insulating material is fixed to the main body with an adhesive. According to the present disclosure, movement of the heat insulating material 70 due to vertical and horizontal vibrations can be suppressed.

[0046] (5) A thermocouple reference junction compensation device according to any one of (1) to (4), which has a gasket disposed on the surface of the lid that comes into contact with the thermal insulator. According to the present disclosure, the thermocouple reference junction compensation box 40 can be sealed without damaging the thermal insulator 70.

[0047] (6) A thermocouple reference junction compensation device including a temperature equalizing block that accommodates a thermocouple reference junction, a main body that accommodates the temperature equalizing block and has one open side, and a heat insulating material that is arranged between the main body and the temperature equalizing block, the heat insulating material being fixed to the main body with an adhesive. According to the present disclosure, the heat insulating material can be fixed while suppressing movement of the heat insulating material 70 due to vertical vibration.

[0048] (7) A method for assembling a thermocouple reference junction compensation device, comprising the steps of: arranging a heat equalizing block to which a reference junction of a thermocouple is fixed in an internal space of a main body; arranging a heat insulating material between the main body and the heat equalizing block; and fixing the heat insulating material to the main body by closing an open side of the main body with a lid. According to the present disclosure, the heat insulating material 70 can be fixed while suppressing movement due to vertical vibration.

[0049] (8) A method for assembling a thermocouple reference junction compensation device, comprising the steps of: placing a heat equalizing block to which a reference junction of a thermocouple is fixed in the interior space of the main body; applying adhesive to the outer circumferential surface of the heat insulating material; and placing the heat insulating material between the main body and the heat equalizing block and fixing the heat insulating material to the main body with the adhesive. According to the present disclosure, the heat insulating material 70 can be fixed while suppressing movement due to vertical vibration. [Explanation of symbols]

[0050] 10 Thermocouple reference junction compensation device 12. Case 13 Hakobe 14 Body flange 15 bolt holes 16 Lid 17 bolt holes 18 volts 19 Nut 20 bottom 21 terminals 24 Cold Junction Compensator 28 Reference Junction 26a, 26b, 32 cables 30 Resistance thermometer 40 Thermocouple reference junction compensation box (compensation box) 42 Main body 44 Flange 45 Notch 48 Interior Space 54 Metal Block 60 Lid 62 Lid opening 64 Gasket 70 Insulation 72 Inner surface 74 Top surface 76 Bottom side 78 Outer surface 90, 92 Adhesive

Claims

1. a thermal equalization block containing the reference junction of the thermocouple; a main body portion that houses the heat equalizing block and has one open surface; a heat insulating material disposed between the main body and the heat equalizing block; a cover portion that covers the one surface of the main body portion, is fixed to the main body portion, and suppresses movement of the heat insulating material within the main body portion, A thermocouple reference junction compensation device having a gasket disposed on a surface of the lid that contacts the insulating material.

2. 2. The thermocouple reference junction compensation device according to claim 1, wherein the heat insulating material has a cylindrical shape and is stacked in multiple layers.

3. 3. The thermocouple reference junction compensation device of claim 2, wherein the insulating material is fixed to an adjacent insulating material with an adhesive.

4. 2. The thermocouple reference junction compensation device according to claim 1, wherein the heat insulating material is fixed to the main body with an adhesive.

5. a thermal equalization block containing the reference junction of the thermocouple; a main body portion that houses the heat equalizing block and has one open surface; a heat insulating material disposed between the main body and the heat equalizing block; a cover portion that covers the one surface of the main body portion, is fixed to the main body portion, and suppresses movement of the heat insulating material within the main body portion, The thermocouple reference junction compensation device includes a plurality of cylindrical insulating materials stacked one on top of the other.

6. a thermal equalization block containing a thermocouple reference junction; a main body portion that houses the heat equalizing block and has one open surface; a heat insulating material disposed between the main body and the heat equalizing block, The heat insulating material has a cylindrical shape and is laminated in multiple layers. The insulating material is fixed to the adjacent insulating material with an adhesive; The thermocouple reference junction compensation device, wherein the heat insulating material is fixed to the main body with an adhesive.

7. placing a heat equalizing block, to which a reference junction of a thermocouple is fixed, in the internal space of the main body; disposing a heat insulating material between the main body and the heat equalizing block; and a step of fixing the heat insulating material to the main body by closing the open side of the main body with a lid.

8. placing a heat equalizing block, to which a reference junction of a thermocouple is fixed, in the internal space of the main body; applying an adhesive to the outer peripheral surface of the insulating material; and placing the insulating material between the main body and a heat equalizing block and fixing the insulating material to the main body with the adhesive.

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