JP4949081B2 - Thermometer for measuring surface temperature of curved surface and arrangement structure of thermometer - Google Patents

Description

The present invention relates to the arrangement structure of the thermometer, and the temperature gauge surface temperature measurement of the surface.

Conventionally, in order to measure the temperature of fluids such as gas and liquid flowing in tanks and heat exchangers, as well as piping and ducts for air conditioning equipment, etc., thermometers are installed on the surfaces of tanks and heat exchangers. In addition to pipes and ducts, the surface temperature of tanks and heat exchangers is measured in addition to pipes and ducts that measure the temperature of fluid in tanks and heat exchangers.
JP 2002-195887 A

  In such conventional temperature measurement, in addition to pipes and ducts, in addition to pipes and ducts, in addition to pipes and ducts, in addition to pipes and ducts, to the surface of tanks and heat exchangers, Open a through-hole that penetrates the insulation covering the surface of the tank or heat exchanger, insert a thermometer in the through-hole, and indirectly measure the temperature of the fluid flowing inside the pipe etc. from the surface of the pipe etc. Yes.

  As an example of a thermometer used for such temperature measurement, a tube wall thermometer as described in JP-A-2002-195887 is known.

  The pipe wall thermometer described in the above publication is a thermometer corresponding only to a specific pipe diameter, and for this purpose, the inner peripheral wall surface of the thermometer main body is assumed to be substantially the same as the radius of curvature of the pipe outer periphery to be attached. In the center of the inner peripheral wall, a through hole is formed through the opposite surface wall, and an elastic body and a temperature detection member are inserted into the through hole, and the temperature detection member is pushed to the outer peripheral wall surface of the pipe by the elastic body. At the same time, the wall surface on the front surface side of the attachment portion is hermetically fixed so as to cover the through hole on the back surface of the thermometer body, and the solar cell portion and the temperature display portion are disposed on the surface of the thermometer body.

  However, since such a pipe wall thermometer is only compatible with a specific pipe diameter as described in the publication, it is necessary to prepare a thermometer for each diameter of the measurement pipe, and the shape is delicate. Due to the difference, an air layer such as a gap is formed between the pipe surface and the thermometer body, and this difference in the thickness of the air layer causes an error for each thermometer.

  Further, as a pipe surface thermometer different from the above pipe wall thermometer, a thermometer as shown in FIG. 16 is generally known as a pipe surface measuring thermometer.

  Such a thermometer 100 is a sensor-type surface temperature sensor, and a ring-type magnet 102 having a hole 103 in the center, and a temperature sensing part A is located on the pipe surface side of the hole 103 in the center of the magnet 102. The thermocouple 106 is disposed in the hole 103 as described above, and a resin 108 for holding the temperature sensitive portion is filled in the gap between the holes 103 in the center, and the thermocouple 106 is supported by the filled resin 108. A drop-off prevention reinforcing member 104 is provided, and an insertion portion 107 is provided at the other end of the thermocouple 10 6 so that it can be connected to required measuring instruments.

  This sensor-type thermometer 100 is installed by providing a predetermined hole in a heat insulating material or a heat insulating material covering the pipe surface, and placing a magnet portion of the thermometer in the hole and adsorbing it on the pipe surface. However, such a sensor type thermometer 100 is based on the premise that the object to be measured is a flat surface temperature sensor. For this reason, a ferrite magnet having a weak magnetic force is generally used for the magnet 102 portion. It is. Moreover, since the normal thermocouple 106 is used for the temperature sensing part A, the temperature sensing part A at the tip of the thermocouple 106 is measured as a “point”.

When such a sensor type thermometer 100 is used, the following problems occur.
1) Because the magnetic force is weak, when used on the pipe surface, the thermometer as a sensor tilts due to its own weight.
2) Production errors are likely to occur, and production that satisfies the necessary conditions is difficult.
3) When filling a predetermined hole with a heat insulating material, there is a possibility that the measurement part of the thermometer is inclined.

  The above problems will be discussed in detail below.

  First, as a problem at the time of installation, the surface of the pipe is a curved surface, and if a magnet having a flat bottom surface is attached, a portion that cannot be in close contact with the pipe surface is generated. As a result, the magnetic force inherently possessed by the magnet cannot be fully exhibited, and the attractive force generally decreases. For this reason, a thermometer as a surface temperature sensor uses a magnet with weak magnetic force, so if it is installed on the pipe surface, the thermometer easily tilts due to the thermometer itself or the weight of the wiring, and the pipe Depending on the mounting location such as the upper surface or the side surface, an air layer is formed between the thermometer and the piping, which causes the measurement value to change.

  As a means for solving this problem, it is conceivable to increase the magnetic force. For example, it is possible to replace the ferrite magnet with a neodymium magnet. With such a method, a strong magnetic force can be obtained and the above-mentioned problems can be solved. However, when the thermometer is removed from the pipe, the adsorption force between the pipe and the magnet is too strong, and the thermocouple is large. A load is applied, and the thermocouple falls off from the resin portion bonded to the magnet. That is, there is a problem of reinforcing the bonded portion between the magnet and the thermocouple.

  Although it is conceivable to remove the magnet part, it is difficult because it cannot be easily removed due to the small magnet part or strong attraction force.

  Next, as a problem at the time of manufacture, it is important that the position of the thermosensitive portion of the thermocouple is arranged at the center of the ring-type magnet in each thermometer. This is a problem that leads to measurement accuracy and difficulty in manufacturing.

  In addition, if the temperature sensing part of the thermometer is at the center of the ring-type magnet, the temperature sensing part will be located in the immediate vicinity of the surface of the pipe. An error occurs in the measured value depending on the direction.

  Moreover, as a problem at the time of heat insulating material construction, when measuring cold water or hot water pipes, the heat insulating material is covered to prevent condensation and heat loss after the thermometer is installed. However, during the covering operation of the heat insulating material, there is a possibility that the thermometer as a sensor is pushed by the heat insulating material and tilted. If the thermometer is tilted, the same effect as described above will occur. Furthermore, since the heat insulation changes depending on the kind of the heat insulating material, the construction procedure, the other construction method, the thickness, etc., it is necessary to unify the construction method finely.

In view of the above problems, the present invention provides a thermometer for measuring a surface temperature of a curved surface having a shape suitable for measuring a surface temperature of a tank, a heat exchanger, etc., in addition to a pipe or duct having a curved surface . It is an object to provide an arrangement structure .

  In order to achieve the above object, a curved surface temperature measuring thermometer according to the present invention includes a ring-shaped magnet having a hole formed in the center thereof, and a metal protective tube having one end inserted into and fixed to the hole of the magnet. A thermocouple disposed in the metal protective tube and having one end positioned near the contact surface of the ring-type magnet with the surface of the object to be measured, and heat conduction to the thermocouple filled in the metal protective tube It is characterized by having a filler for improving the viscosity.

  The construction method of the surface temperature measurement thermometer for the curved surface of the object to be measured flowing in the inside of the present invention is a ring-type magnet having a hole formed in the center, and one end is inserted into and fixed to the hole of this magnet. A metal protection tube, a thermocouple placed in the metal protection tube, and a thermocouple located near the contact surface with the surface of the object to be measured on the lower surface of the ring magnet, and filled in the metal protection tube In order to install a thermometer for surface temperature measurement with a filler that improves heat conduction to the thermocouple on the surface of the curved surface covered with the heat insulating material, a drilling jig is used on the surface of the heat insulating material. A step of drilling a hole, a step of placing and attaching a thermometer in a hole opened in the heat insulating material, and a step of closing the opening of the heat insulating material in which the thermometer is installed with aluminum foil or aluminum tape. It is characterized by. Further, the construction method of the thermometer for measuring the surface temperature of the curved surface of the object to be measured, in which the fluid flows in the present invention, the drilling jig has a hollow cylindrical member having a blade formed at one end, and the blade edge is kept warm. It is preferable to provide a protective cap that can be pushed into the surface of the material to open a hole and that covers the cutting edge of one end of the drilling jig.

  The method for measuring the surface temperature of an object to be measured having a curved surface in which a fluid flows inside is to measure the surface temperature of the object to be measured having a curved surface whose surface is covered with a heat insulating material and in which the fluid flows. In addition, a process for installing a thermometer by making a hole in the surface of the heat insulating material, placing a thermometer for measuring the surface temperature in the hole and bringing the ring-shaped magnet of the thermometer into contact with the curved surface, and the ambient temperature in the opening A step of placing another ambient thermometer in the opening for measuring the temperature, a step of closing the opening of the heat insulating material with aluminum foil or aluminum tape after the placement of the ambient thermometer, the temperature of the curved surface and the inside of the opening And a step of correcting the measured value of the curved surface temperature based on the difference between the curved surface temperature measured by measuring the ambient temperature and the ambient temperature in the opening. Moreover, this measuring method can punch a hole by inserting a drilling jig having a hollow cylindrical member having a blade formed at one end into the surface of the heat insulating material covering the surface of the curved surface.

  According to the present invention, the thermometer for measuring the surface temperature of the curved surface has a shape suitable for the measurement of the surface temperature of the curved surface of the object to be measured, and regardless of who is performing the measurement, the thermometer for measuring the surface temperature is used. This provides a thermometer with a constant measurement condition and its construction method, and corrects the relationship between the measured value obtained and the temperature inside the heat insulation material opening of the object to be measured. Temperature can be measured.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.
Example 1
FIG. 1 is a schematic cross-sectional view showing a surface temperature measurement thermometer in a pipe or duct as an example of an object to be measured in the present invention.

  As shown in the figure, a thermometer 1 for measuring a surface temperature according to the present invention includes a ring-type magnet 2 having a hole 3 formed in the center, and a metal protective tube having one end inserted into and fixed to the hole 3 of the magnet 2. 4, a thermocouple 6 disposed in the metal protective tube 4 and having one end positioned in the vicinity of the contact surface 2 a with the pipe surface of the magnet 2, and the heat to the thermocouple 6 filled in the metal protective tube 4 And a filler 8 for improving conduction.

  A thermometer 1 for surface temperature measurement according to the present invention includes a ring-type magnet 2 having an inner diameter that matches the outer diameter of a metal protective tube 4 and an epoxy resin adhesive. The plug 7 is provided at the other end of the thermocouple 6 so that it can be connected to required measuring instruments.

  In the illustrated embodiment, the lower part of the thermometer 1 for surface temperature measurement attached to the outer peripheral surface of the pipe 10 by the magnet 2 is shown in cross section, and a part of the pipe 10 as an object to be measured is shown. The heat insulating material covering the other part of the pipe 10 and the surface of the pipe 10 is not shown and is omitted. Further, the pipe 10 is not limited to a pipe through which a fluid such as cold water or hot water flows, but can be used for a similar one such as a duct, tank, heat exchanger or the like for air conditioning.

  In such a thermometer 1 for surface temperature measurement of the present invention, the magnet 2 is preferably a neodymium magnet having the strongest magnetic force among permanent magnets, and the thermocouple 6 is a thermoelectric with a metal protective tube 4. It is also important to use a pair and to flatten the bottom surfaces of the magnet 2 and the metal protective tube 4 to be bonded. As the metal protective tube 4, for example, stainless steel can be used, which has a cylindrical and flat bottom surface and is open upward. For example, magnesium oxide is used as the filler 8 filled in the metal protective tube 4. After filling such a material with good thermal conductivity, the measuring unit of the thermometer 1 can be configured by covering with a resin. Here, the thermocouple 6 is held by metal powder, but a material having good thermal conductivity may be melted and flown around the material to be solidified.

  A thermocouple 6 is disposed inside a metal protective tube 4 that is inserted into the hole 3 of the ring-type magnet 2 and fixed by an adhesive. The thermocouple 6 is disposed in the metal protective tube 4 so as to be disposed along the axis of the metal protective tube 4, and the tip portion is positioned in the vicinity of the contact surface 2 a with the pipe 10 of the magnet 2. That is, the tip portion can be provided so as to be located slightly away from the contact surface 2a. That is, the tip of the thermocouple 6 is not brought into contact with the pipe surface (outer peripheral surface). As a result, the measurement unit can be prevented from being affected even when a minute current flows through the pipe.

  This is to prevent the tip of the thermocouple 6 from coming into contact with the outer peripheral surface of the pipe 10 and being damaged. Thereby, when the thermometer 1 is installed on the outer peripheral surface of the pipe 10, the thermometer 1 is favorably provided with a temperature sensing portion for the contact surface 2 a of the hole 3 of the magnet 2.

  In such a thermometer 1 for measuring a surface temperature of the present invention, by using a neodymium magnet having a strong magnetic force, it is possible to prevent the thermometer 1 from being inclined due to its own weight, and to eliminate the restriction of the mounting location. It becomes. Further, the use of the metal protective tube also eliminates the concern about the problem of removing the thermometer 1. That is, when the thermometer 1 is attached or detached, if the thermometer 1 is tilted so as to be tilted by holding the upper portion of the metal protective tube 4 of the thermometer 1 standing upright on the outer peripheral surface of the pipe 10, the magnet 2 The magnet 2 is raised obliquely from the outer peripheral surface of the pipe 10 by the action of the lever with a part of the outer peripheral edge of the contact surface 2 a as a fulcrum, whereby the magnet 2 is separated from the outer peripheral surface of the pipe 10. Next, if the metal protective tube 4 is held and lifted upward, the thermometer 1 can be easily detached from the pipe 10. Thereby, since no force is applied to the wiring of the thermocouple 6 when the thermometer 1 is attached / detached, reinforcement for preventing the metal protective tube 4 from falling off the magnet 2 is not required.

  Further, by using such a metal protective tube 4, the temperature-sensitive portion on the contact surface 2 a of the magnet 2 with respect to the pipe 10 of the thermometer 1 and the contact portion of the filler 8 filled in the metal protective tube 4 are surfaced. Thus, by matching the bottom surface of the metal protective tube 4 of the ring-shaped magnet 2, the temperature sensing part comes into contact with the pipe 10 reliably, and heat such as magnesium oxide filled in the metal protective tube 4 is obtained. Even if the position of the temperature measuring junction of the thermocouple 6 is slightly different inside the metal protective tube 4 by the individual thermometers 1 due to the filling with the high conductivity filler 8, this difference is the measured value. The impact on the is extremely small. Therefore, as a result, since there is no strict restriction on the position of the temperature measuring junction of the thermocouple 6, the manufacture is facilitated.

The following advantages are obtained by the thermometer 1 for measuring a surface temperature of the present invention configured as described above.
1) A strong magnetic force can be exerted even on an object to be measured whose surface is curved, and it can be firmly attached, so that it can be easily removed even when the object to be measured is vibrated or shocked from the outside. It will not shift.
2) Due to the above, the mounting posture is constant, and the inclination due to the weight of the thermometer and the weight of the wiring is reduced.
3) From the above, there is no individual difference in installation, and constant measurement is always possible.
4) By using a thermocouple with a metal protection tube and filling the metal protection tube with a filler such as magnesium oxide, there is no problem even if the thermocouple's temperature measuring contact is slightly displaced, and manufacturing errors can be reduced. In addition, manufacturing is also easy.
5) By flattening the bottom surface of the magnet and the metal protective tube, the bottom surface of the metal protective tube always comes into contact with the object to be measured even on the curved surface of the object to be measured.
6) The thermometer can be easily attached and detached.
7) The need for reinforcement for preventing the metal protective tube from falling off is eliminated.

  In relation to the above advantages, a drilling jig manufactured for thermometer mounting and its working examples will be described in detail below.

In the above-described embodiments, the thermometer of the present invention has been described as a thermometer for measuring the pipe surface temperature. However, the present invention can be applied not only to pipes but also to air conditioning ducts, tanks, heat exchangers, and the like. It is.
(Example 2)
Next, the construction method of the thermometer in the case of performing temperature measurement using the above-described surface temperature measurement thermometer of the present invention will be described.

The construction method of the thermometer for measuring the surface temperature of the curved surface of the measured object through which the fluid flows in the present invention,
A ring-type magnet with a hole formed in the center, a metal protective tube with one end inserted into and fixed to the hole of the magnet, and a temperature-sensing portion disposed at one end of the bottom surface of the ring-type magnet A thermometer for measuring a surface temperature having a thermocouple located in the vicinity of the contact surface with the surface of the object to be measured on the side, and a filler filled in a metal protective tube to improve heat conduction to the thermocouple, A step (first step) of making a hole on the surface of the heat insulating material using a drilling jig in order to install it on the surface of the object to be measured covered with the heat insulating material;
A process (second process) in which a thermometer is placed and installed in the hole opened in the heat insulating material,
A process (third process) of closing the opening of the heat insulating material in which the thermometer is installed with aluminum foil or aluminum tape;
These first to third steps are shown for each step in FIGS. 2 to 4.

  In the construction method of the surface temperature measurement thermometer of the curved surface of the object to be measured in which fluid flows inside the present invention, when the surface temperature measurement thermometer described above is installed on the object to be measured, It is necessary to first remove the heat insulating material covering the object to be measured. That is, even if it is an existing installation or a new installation, the entire outer periphery of the object to be measured is covered with a heat insulating material, and the measurement site is exposed to this.

  The removal of the heat insulating material in the first step is performed using a drilling jig as shown in FIG. The detailed configuration of the drilling jig will be described in detail later.

  As a result, an opening of the same size is always obtained for the heat insulating material of the object to be measured, regardless of who constructs it.

  In this embodiment, a method for constructing a thermometer for measuring a surface temperature in a pipe or duct as an example of an object to be measured in the present invention will be described.

  As shown in FIG. 2, the tip of the blade 24 of the drilling jig 20 is applied to the surface of the heat insulating material 12 of the pipe 10 to be drilled, and the drilling jig 20 is screwed into the heat insulating material 12. Press to. Thereby, the tip of the blade 24 of the drilling jig 20 bites into the heat insulating material 12 and cuts the exterior material of the heat insulating material 12. Thereby, the opening 14 is formed.

  In this way, when the hole is formed in the heat insulating material 12 and the opening 14 is formed, the thermometer 1 is installed in the opening 14 of the heat insulating material 12 as the second step. This second step is illustrated in FIG.

  As shown in the figure, a thermometer for measuring the surface temperature of the pipe or duct described above is used as the thermometer 1, and the thermometer 1 is placed in the opening 14 opened in the heat insulating material 12 of the pipe 10. Installed. The installed thermometer 1 for surface temperature measurement is installed in a state in which the lower magnet 2 is attracted to the outer peripheral surface of the pipe 10 and stands upright in the opening 14. The state of this second step is shown in FIG.

When the surface temperature measuring thermometer 1 is thus installed in the opening 14 of the heat insulating material 12, the wiring 9 such as a lead wire of the thermometer 1 extends along the outer peripheral surface of the heat insulating material 12 of the pipe 10. Arranged in such a manner that an exterior material such as aluminum foil or aluminum tape 16 is attached to the entrance of the opening 14 to close the opening 14. This third step is illustrated in FIG. Thus, if the thermometer 1 is installed in the opening part 14 of the heat insulating material 12 of the pipe 10, the inlet of the opening part 14 is made of an aluminum foil or an inlet without filling the opening part 14 without being heated. It is closed with aluminum tape 16. The following advantages and disadvantages are observed when the opening 14 is closed with the aluminum foil or the aluminum tape 16 without keeping the temperature.
(advantage)
1) The thermometer is not tilted by the heat insulating material when the heat insulating material is filled.
2) The thermometer installation procedure can be unified.
3) Workability at the time of thermometer installation can be improved.
(Disadvantage)
1) The influence of ambient temperature is easily transmitted to the thermometer.
2) There is a possibility of condensation on the surface of aluminum tape or aluminum foil.

  In the above disadvantage, the influence of the ambient temperature in 1) can be solved by grasping the relationship between the temperature inside the opening of the heat insulating material, the measured value, and the temperature in the pipe. When this problem is solved, it is advantageous in that it is easily influenced by the ambient temperature. The reason for this point and the measurement method will be described later.

  In addition, regarding the possibility of condensation for not performing heat insulation, the surface temperature of the aluminum tape or the aluminum foil is more strongly affected by the ambient temperature than the temperature inside the pipe. Therefore, there is no problem because the surface temperature of the aluminum tape or aluminum foil does not decrease to the extent that condensation occurs.

  5 to 7 show a drilling jig used in connection with the construction method of the thermometer for measuring the surface temperature of the pipe or duct of the present invention, its use state, and a protective cap.

  As shown in FIG. 5, the drilling jig 20 is composed of a hollow cylindrical member 22 made of, for example, stainless steel, and a blade 24 is formed at one end thereof. The blade 24 preferably has an angle of approximately 10 ° to 20 °. As an example, the blade 24 may have an outer diameter of approximately 40 mm and a length of approximately 100 mm.

  Such a drilling jig 20 has an opening for attaching the pipe surface temperature measuring thermometer 1 to a heat insulating material 12 such as an aluminum foil heat insulating cylinder constructed in cold water or hot water system of the air conditioning pipe 10. It is used when opening as the part 14.

  In this way, the drilling jig 20 is constituted by the stainless steel cylindrical member 22, one end is cut so that the tip is sharp, the blade 24 is provided, and the heat insulating material 12 covering the pipe 10 is provided. It is easy to penetrate, and it is possible to easily open the opening 14 of a certain size at an arbitrary or predetermined place of the pipe 12 and obtain the opening 14 of the same size no matter who constructs it. Can be done. In addition, since the heat insulating material 12 of the pipe 10 is layered, the heat insulating material 12 is once pushed into the heat insulating material 12 using the drilling jig 20 and inserted, and then the drilling jig 20 is extracted. The heat insulating material 12 into which the jig 20 has been inserted stays inside the drilling jig 20, and the opening 14 can be formed cleanly. This state is shown in FIG. In this embodiment, the heat insulating material 12 of the pipe 10 has an outer peripheral surface of the heat insulating material 12 such as glass wool covered with an aluminum sheet as an exterior material.

  As shown in FIG. 7, when drilling the heat insulating material 12 at a required place with respect to the pipe 10, the blade 24 of the drilling jig 20 is attached to the heat insulating material 12 with respect to the heat insulating material 12 covering the pipe 10. If the outer material is pressed against the surface of the outer material and rotated, and the outer material is cut and then inserted, the tip of the blade 24 of the drilling jig 20 cuts the heat insulating material 12 and bites in. By pulling out 20, the heat insulating material 12 staying inside the drilling jig 20 can be removed so as to be pushed out from the opposite side when the blade 24 at the tip of the drilling jig 20 is shaved. Thus, the opening part 14 for installing the thermometer 1 in the heat insulating material 12 of the pipe 10 can be provided.

  As described above, it is sufficiently possible to provide the opening 14 in the heat insulating material 12 of the pipe 10 using only the drilling jig 20, but the other end of the drilling jig 20 can be placed with a palm every time a hole is drilled. You have to press it and you may hurt your hands. In order to eliminate the possibility of hurting such a hand, a protective cap for use with the drilling jig 20 is shown in FIG.

  As shown in the drawing, the protective cap 30 is made of rubber, a soft synthetic resin material, or urethane rubber having high heat insulation properties, and is formed of a cylindrical portion 32 and a top portion 34. The cylindrical portion 32 has an inner diameter dimension that is slightly smaller than the outer dimension of the drilling jig 20, and has a dimension that fits perfectly so that it does not fall off when fitted into the drilling jig 20. Is preferred.

  If such a protective cap 30 is attached to the drilling jig 20 and used to make a hole in the heat insulating material 12 of the pipe 10, the protective cap 30 is made of rubber or a soft synthetic resin material. You can pierce well without slipping and do not hurt your hands. Moreover, since the protective cap 30 is made to be slightly smaller than the outer dimension of the drilling jig 20, it does not drop out naturally and can be prevented from falling off.

In addition, after the drilling jig 20 is used, the protective cap 30 is attached to the blade 24 side of the drilling jig 20 to prevent the blade 24 from being chipped while the drilling jig 20 is being carried or to damage the human body. Can be prevented.
(Application examples)
Next, an application example using the above-described drilling jig 20 will be described.

  As shown in FIGS. 8 and 9, in this application example, the drilling jig 20 is prepared by being made approximately 10 mm longer than the thickness of the heat insulating material 12 of the pipe 10. Further, the protective cap 30 is made of urethane rubber having high heat insulation properties.

  Using such a drilling jig 20 and the protective cap 30, as shown in FIG. 8, the drilling jig 20 is pushed into the heat insulating material 12 of the pipe 10 to make a hole, and the inside of the drilling jig 20 is Empty and place the thermometer 1 inside the drilling jig 20. A wire 9 such as a lead wire of the thermometer 1 is extended to the outside of the drilling jig 20 and connected to a measuring instrument, and a protective cap 30 of urethane rubber with high heat insulation is fitted to the upper end of the drilling jig 20 and attached. . By using a protective cap 30 with high heat insulation such as urethane rubber, the inside of the drilling jig 20 in which the thermometer 1 as a sensor is installed is similar to a pipe insertion type protective tube. .

In this way, when the necessary surface temperature of the pipe 10 is measured and the measurement is completed, by removing only the thermometer 1, the trouble of repairing the opened heat insulating material 12 can be saved and at the same time, for example, 1 When the measurement is performed again after a year or the like, it is not necessary to make a hole again, and the measurement can be performed while keeping the measurement conditions constant, and a highly accurate measurement value can be obtained.
(Example 3)
Next, a measurement method in the case of performing temperature measurement using such a surface temperature measurement thermometer of the present invention will be described.

The method for measuring the surface temperature of an object to be measured which has a curved surface and a fluid flows inside the present invention,
In order to measure the surface temperature of the object to be measured that has a curved surface covered with a heat insulating material and fluid flows inside, a hole is made in the surface of the heat insulating material and a thermometer for measuring the surface temperature is placed in the hole. Attaching the thermometer by bringing the ring-shaped magnet of the thermometer into contact with the curved surface (first step);
Placing another ambient thermometer in the opening for measuring the ambient temperature in the opening (second step);
A step (third step) of closing the opening of the heat insulating material with aluminum foil or aluminum tape after the ambient thermometer is arranged;
A step of correcting the measured value of the surface temperature of the curved surface by a difference between the surface temperature of the curved surface measured by measuring the temperature of the curved surface and the ambient temperature in the opening and the ambient temperature in the opening (fourth step);
It is characterized by comprising.

  In this embodiment, a method for measuring the surface temperature of a pipe or duct as an example of the object to be measured in the present invention will be described.

  In the method for measuring the surface temperature (temperature of the outer peripheral surface) of a pipe or duct, which is a measurement object having a curved surface and in which a fluid flows, in the present invention, the temperature inside the opening 14 of the heat insulating material 12 is kept warm. It is impossible to completely suppress the influence of the ambient temperature. When the ambient temperature changes by 10 ° C., the influence changes by 0.4 ° C. to 0.5 ° C. as a measured value (see FIG. 10).

  Here, a general correction method is to measure the ambient temperature with another thermometer installed outside the heat insulation near the measurement location, and measure the relationship between the ambient temperature, the measured value of the pipe surface thermometer, and the temperature in the pipe. It is derived and corrected.

  However, with this method, if the ambient temperature changes suddenly during pipe surface temperature measurement, the thermometer that measures the ambient temperature measures the pipe surface temperature, although the measured value also changes according to the change. The thermometer is not immediately transmitted to the thermometer due to the effect of heat retention in the opening. In other words, because the time constants of the ambient thermometer and the pipe surface thermometer are different, the relationship between the ambient temperature, the measured value, and the temperature in the pipe cannot be easily applied, and the speed at which heat is transferred through the heat insulating material opening is also considered Necessity comes out.

  On the other hand, when the construction method of FIG. 2 to FIG. 4 is used, the measured value changes by 0.7 ° C. to 0.8 ° C. when the ambient temperature changes by 10 ° C. (see FIG. 11). As compared with the case where the inside of the opening is kept warm, the influence of the ambient temperature is stronger. However, the effect is linear with respect to the ambient temperature and can be easily corrected.

  For correction of the measured value, conventionally, the temperature at which the external ambient temperature is measured, that is, the temperature inside the heat insulating material opening measured by the ambient thermometer 1A in the present invention is used (FIG. 12). As shown in the drawing, in the opening 14 formed in the heat insulating material 12 of the pipe 10, an ambient thermometer 1 </ b> A is arranged in addition to the pipe surface temperature measuring thermometer 1, and the surface temperature of the pipe 10 and the opening 14 are arranged. Measure the ambient temperature inside. As a result, the difference in time constant between the pipe surface temperature measuring thermometer 1 and the ambient thermometer 1A is reduced, and as a result, highly accurate measurement and correction are possible even in an environment where the ambient temperature changes suddenly.

  As shown in FIG. 12, the temperature in the pipe as an experimental result when the thermometer 1 for pipe surface temperature measurement of the present invention of FIG. 1 is used and the thermometer 1 is attached according to the procedure of FIGS. The measured values for are shown in FIGS.

  In FIG. 13 to FIG. 15, the measurement values are corrected by the temperature inside the heat insulating material opening as the ambient temperature measured by another thermometer as the ambient thermometer and the thermometer for measuring the pipe surface temperature in the heat insulating material opening. This is done by grasping the relationship between both measured values and the pipe surface temperature measured by.

  FIG. 13 is a graph showing the measured value for the temperature in the pipe and the error due to the temperature in the pipe according to the ambient temperature when the pipe surface temperature measuring thermometer is installed according to the procedure of FIGS. FIG. 15 is a graph showing the relationship between the measured value for the difference between the temperature in the pipe and the temperature inside the heat insulating material opening and the temperature in the pipe, and FIG. 15 is a graph showing the error after correction of the measured value with respect to the temperature in the pipe. is there.

  13 to 15, it is possible to perform correction with accuracy of ± 0.2 ° C. by correcting the measured value and the temperature inside the heat insulating material opening.

  That is, in FIG. 13, an error (measurement value−in-pipe temperature) with respect to the in-pipe temperature as a measurement value increases with the ambient temperature in relation to the change in the in-pipe temperature.

  Thereby, the relationship between the heat insulating material opening internal temperature and the pipe internal temperature is expressed by the following equation.

Error = Ax (Temperature in piping-Temperature inside heat insulation material opening) + B
However, A is a time constant according to the measuring method of the present invention, and B is an instrumental difference for each measuring instrument.

  Therefore, as shown in FIG. 15, an error with respect to the difference between the temperature inside the pipe and the temperature inside the heat insulating material opening can be measured with an accuracy within ± 0.2 ° C.

  As described above, the curved surface temperature measuring thermometer according to the present invention has a function of facilitating the manufacture and improving the attachment / detachment work by using a thermocouple with a metal protective tube. The construction method using such a thermometer, combined with the use of a drilling jig, makes it possible to unify the construction conditions and measure the surface temperature of the object to be measured with a curved surface through which fluid flows. The method can measure with high accuracy by correcting the measurement value based on the internal temperature of the heat insulating material opening.

  It can be used not only for measuring the temperature of the fluid flowing in the piping but also for measuring the temperature of the fluid in an air conditioning duct, tank, heat exchanger, or the like.

Cross-sectional schematic diagram showing a thermometer for measuring the surface temperature of a curved surface in the present invention, The figure which shows the procedure of the construction method which attaches the thermometer of FIG. 1, The figure which shows a drilling process, The figure which shows the attachment process of the thermometer following FIG. The figure which shows the process of plugging a hole, after installing a thermometer following FIG. An enlarged cross-sectional view showing a drilling jig, The expanded sectional view which shows the protective cap with which the drilling jig of FIG. 5 is mounted, FIG. 5 is an enlarged schematic cross-sectional view showing a state in which a hole is formed in the heat insulating material of the pipe with the drilling jig of FIG. An enlarged cross-sectional schematic diagram showing an application example using the drilling jig of FIG. In the application example of FIG. 8, an enlarged cross-sectional schematic diagram showing a state where the thermometer is removed after the measurement is completed, In the method for measuring the surface temperature of the object to be measured of the present invention, a graph showing a temperature error at the time of heat insulation construction in the heat insulation material opening, Graph showing temperature error when the heat insulation material opening is closed with aluminum tape, Cross-sectional schematic diagram showing a measurement method in which a thermometer and an ambient thermometer are installed inside the heat insulating material opening, A graph showing the measured value for the temperature in the pipe when the thermometer is installed in the procedure of FIGS. 2 to 4 and the error due to the temperature in the pipe for each ambient temperature, A graph showing the relationship between the measured value for the difference between the temperature inside the pipe and the temperature inside the heat insulating material opening and the temperature inside the pipe, A graph showing the error after correction of the measured value with respect to the temperature in the pipe, It is a cross-sectional schematic diagram which shows an example of the conventional thermometer for piping surface temperature measurement.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Thermometer for surface temperature measurement of piping 2 Ring-type magnet 2a Contact surface 3 Hole 4 Metal protective tube 6 Thermocouple 8 Filler 10 Piping 12 Heat insulating material 14 Opening part 20 Drilling jig 22 Cylindrical member 24 Blade 30 Protection cap 32 Cylindrical part 34 Top part

Claims (2)

  A ring-type magnet having a hole formed in the center; a metal protective tube having one end inserted into and fixed to the hole of the magnet; and one end disposed in the metal protective tube and the pipe surface of the ring-type magnet A thermometer for measuring the surface temperature of a curved surface, comprising: a thermocouple located in the vicinity of the contact surface; and a filler filled in the metal protective tube to improve heat conduction to the thermocouple. An arrangement structure of a thermometer, wherein the thermometer according to claim 1 is arranged in a hole provided in a heat insulating material covering the pipe surface, and an ambient thermometer is arranged in the hole.

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