JP2006078305A - Turbine temperature measuring device and temperature measuring device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a turbine temperature measuring device capable of securing response speed, and suppressing vibration. <P>SOLUTION: This turbine temperature measuring device for measuring the steam temperature in a turbine is formed by inserting a sheathed thermocouple into a metal protection tube and by projecting the tip part of the sheathed thermocouple from the tip of the metal protection tube. Chrome carbide is coated with the thickness of 0.07-0.2 mm by spraying on the whole periphery in a range wherein some position within 5 mm in the tip direction from a metal protection tube tip equivalent position on the sheath surface of the sheathed thermocouple is used as the start point and some position in the length direction from backward 50 mm to 100 mm is used as the end point, and the outer diameter of the sheath is formed to be a narrow outer diameter of the diameter of 4-8 mm in the ranged of 10-20 mm in the tip part axial direction, and a part other than the tip part is formed to have the outer diameter of the diameter of 10-20 mm. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a turbine temperature measuring device and a temperature measuring device for measuring the temperature of a gas fluid in a turbine.

  FIG. 2 shows a conventional typical turbine temperature measuring device for measuring the temperature of the gas fluid in the turbine.

  Reference numeral 1 denotes a metal protective tube for protecting the sheath type thermocouple 2. The sheath type thermocouple 2 accommodates the thermocouple core wire in a metal sheath such as SUS316 with an inorganic insulating material such as magnesium oxide (MgO) interposed therebetween. The ring 3 is fixed to the sheathed thermocouple 2 by welding, fixes the sheathed thermocouple 2 to the metal protective tube 1, and shuts off the atmosphere inside and outside the turbine. An adapter 4 for installing the temperature measuring device on the turbine wall is welded to the metal protective tube 1. The screw 5 presses the ring 3 against the adapter 4. The terminal box 6 connects a thermocouple core wire attached to the end of the sheath type thermocouple 2 with an external cable.

  In this temperature measuring device, a male screw engraved on the outside of the adapter 4 of the ring 3 is screwed to a female screw engraved on the turbine wall. The part below the adapter 4 is inserted into the turbine to measure the temperature of the high flow rate gas. The insertion length is approximately 1 m.

The sheath thermocouple of the sheath type thermocouple 2 and the metal protective tube 1 are fixed by a ring 3. The sheath thermocouple 2 and the metal protective tube 1 are not fixed in the portion ahead of the ring 3 in order to absorb the difference in thermal expansion due to temperature difference and material difference during measurement.
Japanese Patent Laid-Open No. 08-077552

  The conventional temperature measuring device as described above has the following problems.

  The metal protective tube 1 is made of a thick metal, and by increasing the diameter, vibration due to the high flow velocity gas to be measured can be suppressed to a small extent, but the sheath type thermocouple 2 is to suppress vibration. If the sheath metal, which is a strong component, is made thick and the diameter is increased, the heat capacity increases and the response speed of the measurement to the temperature change of the gas being measured slows down, ensuring the response speed and suppressing vibration. Was difficult.

  When vibration is generated in the sheath type thermocouple 2, the outer surface of the sheath type thermocouple 2 is brought into contact with the tip portion of the metal protective tube 1 and the sheath type thermocouple 2 because the ring 3 vibrates on the structure described above. The sheath of the steel is worn and eventually damaged, and gas enters the sheath, breaking the insulation and losing its function as a sensor. For this reason, the lifetime as a measuring device becomes short.

  Therefore, in view of the above circumstances, the present invention inserts a sheathed thermocouple into a metal protective tube in order to secure response speed and suppress wear of the sheath due to vibration, and the tip of the sheathed thermocouple is attached to the sheathed thermocouple. In the turbine temperature measuring device for measuring the temperature of steam in the turbine protruding from the tip of the metal protective tube, any one of the ranges of 5 mm in the tip direction from the position corresponding to the tip of the metal protective tube on the sheath surface of the sheath type thermocouple Chrome carbide is coated by thermal spraying at a thickness of 0.07 to 0.2 mm on the entire circumference starting from this position and ending at any position in the length direction from 50 mm to 100 mm behind. And a turbine temperature measuring instrument in which the outer diameter of the sheath is formed to be a thin outer diameter of 4 to 8 mm in the range of 10 to 20 mm in the axial direction of the tip, and the outer diameter of the sheath other than the tip is formed to be 10 to 20 mm. It was.

  In addition, the present invention secures a response speed and suppresses sheath wear due to vibration, and specifically, from the position corresponding to the tip of the metal protective tube on the sheath surface of the sheath type thermocouple to the tip direction. Coating the chromium carbide with a thickness of 0.07 to 0.2 mm by thermal spraying on the entire circumference in the range starting from any position in the range of 5 mm and ending in the length direction position of the rear 70 mm, In addition, a turbine temperature measuring instrument was formed in which the outer diameter of the sheath was formed to be a thin outer diameter of 6 mm in the range of 16 mm in the axial direction of the distal end, and the outer diameter other than the distal end was formed to be 15 mm.

  Furthermore, the present invention secures response speed and suppresses abrasion of the sheath due to vibration, and replaces chromium carbide with a carbide alloy or wear-resistant ceramic on the surface of the sheath type thermocouple. It is coated by thermal spraying or vapor deposition.

  Furthermore, the present invention secures a response speed and suppresses abrasion of the sheath due to vibration, and the surface of the sheath type thermocouple is made of chromium carbide, carbide alloy or wear-resistant ceramic. Is a temperature measuring device for measuring a liquid or gas having a high flow rate coated by welding or vapor deposition.

  As described above, the present invention provides a turbine temperature for measuring the temperature of steam in a turbine in which a sheathed thermocouple is inserted into a metal protective tube, and the tip of the sheathed thermocouple is protruded from the tip of the metal protective tube. In the measuring instrument, any position in the length direction from 50 mm to 100 mm starting from any position within a range of 5 mm from the position corresponding to the tip of the metal protective tube on the sheath surface of the sheath type thermocouple to the tip direction. The outer circumference of the sheath is coated with chrome carbide at a thickness of 0.07 to 0.2 mm by thermal spraying, and the outer diameter of the sheath is 4 mm in the range of 10 to 20 mm in the tip axial direction. Since the turbine temperature measuring instrument is formed to have a thin outer diameter of ˜8 mm and the outer diameter is 10 to 20 mm except for the tip, the response speed can be ensured and the sheath wear due to vibration can be suppressed.

  Further, in the present invention, any position within the range of 5 mm from the position corresponding to the tip of the metal protective tube on the sheath surface of the sheath type thermocouple to the tip direction is set as the starting point, and the position in the length direction of 70 mm behind is set as the end point. The outer periphery of the sheath is coated with chrome carbide with a thickness of 0.07 to 0.2 mm by thermal spraying, and the outer diameter of the sheath is formed in a narrow outer diameter of 6 mm in the range of 16 mm in the axial direction of the tip, Since the turbine temperature measuring instrument is formed with an outer diameter of 15 mm except for the tip, the response speed can be ensured and the sheath wear due to vibration can be suppressed.

  Furthermore, since the present invention is a turbine temperature measuring device in which a carbide alloy or a wear-resistant ceramic is coated on the surface of a sheathed thermocouple instead of chrome carbide by spraying or vapor deposition, the response speed is ensured, In addition, wear of the sheath due to vibration can be suppressed.

  Furthermore, the present invention provides a temperature measurement for measuring a high flow rate liquid or gas in which a surface of a sheathed thermocouple is coated with chrome carbide, carbide alloy or wear-resistant ceramic by welding or vapor deposition. Since the container is used, the response speed can be ensured and the sheath wear due to vibration can be suppressed.

  A sheathed thermocouple according to the present invention is shown in FIG. FIG. 1 shows the sheath-type thermocouple 2 of FIG. 2 taken out and drawn, and the overall configuration is the same as FIG.

  The turbine temperature measuring instrument of the present invention measures the temperature of steam in the turbine.

  As shown in FIG. 1, in the present invention, the surface of the sheath of the sheath type thermocouple 2 is coated with chrome carbide by spraying with a thickness of 0.07 to 0.2 mm as a guide. The coating range is a range in which the sheath tip of the sheath type thermocouple 2 has a slight margin at the contact portion with the metal protective tube 1 due to the vibration, that is, 5 mm in the distal direction from a position corresponding to the tip of the metal protective tube 1. This is the entire circumference of the sheath surface in the axial range of 70 mm rearward, starting from any position in the range. A chromium carbide is coated in the range indicated by reference numeral 7.

  In FIG. 1, the location indicated by A is the tip position of the metal protective tube 1, and the axial range of the coating is a range of 0 to 5 mm and b of 70 mm.

  The sheath outer diameter is 15 mm, but the axial direction 16 mm from the tip is a thin outer diameter of 6 mm.

  Even if the sheath type thermocouple 2 is coated with high hardness chromium carbide as described above, the sheath diameter is reduced and vibration due to a high flow rate gas is generated. And a long-life turbine temperature measuring instrument can be obtained without sacrificing the response speed.

  In the temperature measuring device having the shape shown in FIG. 2, a high-flow-rate gas is obtained by using the sheath-type thermocouple 2 coated with the above-mentioned coating and the one using the uncoated sheath-type thermocouple 2 having the same size and shape. As a result of the comparison of the amount of wear, the sheath wear depth was more than twice that of the latter, and it was confirmed that the coating was effective in extending the life of the sheath.

  Furthermore, by reducing the sheath diameter only at the tip, which is the temperature measurement point of the sheath type thermocouple 2, the heat capacity at the tip can be reduced to ensure response speed, and at the same time, the sheath diameter can be increased except at the tip. The effect of extending the life of the measuring instrument can be obtained by reducing the wear of the coated sheath by suppressing the vibration intensity.

  For example, by setting the outer diameter of the sheath tip to φ6 mm and the diameter other than the tip to φ15 mm, a response speed equivalent to that of a sheath type thermocouple having an outer diameter of φ6 mm can be obtained, and regarding vibration, the outer diameter of the sheath is φ15 mm. Vibration can be suppressed to the same level as a thermocouple.

  The response speed of the sheath diameter at the distal end portion of the sheath thermocouple increases as the diameter decreases. However, if the diameter is too small, deformation and breakage occur due to gas flow. Further, the axial length of the small-diameter portion needs to be a certain length or more in order to ensure the response speed. However, if the length is too long, the same problem occurs. The narrow diameter part of the sheath tip has an outer diameter of 4 to 8 mm and a length of 10 to 20 mm, thereby satisfying the response speed required for the turbine temperature measuring instrument, that is, within a few seconds as the time constant, and depending on the gas flow in the turbine There is no damage.

  Although vibrations can be suppressed by making the diameter other than the tip portion thicker, excessively thickening causes an increase in the size of the turbine temperature measuring device and adversely affects the gas flow. Moreover, it is not economically advantageous in the production of the turbine temperature measuring device.

  From these viewpoints, it is appropriate that the outer diameter of the sheath other than the tip is φ10 to 20 mm.

  The diameter of the hole for inserting the sheath type thermocouple of the metal protective tube is about 0.5 mm larger than the outer diameter of the sheath in consideration of the difference in thermal expansion with the sheath type thermocouple. The insertion length is about 1 m as described above.

  Contact between the metal protective tube and the sheath-type thermocouple having the above-described shape due to vibration, and wear of the sheath due to the contact mainly occur in a range of about 50 mm from the tip of the metal protective tube. Therefore, the coating range to be applied to the sheath surface needs to be at least one of the positions within the range of 5 mm from the position corresponding to the tip of the protective tube in the direction of the tip and the axial range up to 50 mm behind, Even taking into account changes in the wear range due to manufacturing errors, differences in sheath diameter, manufacturing errors, etc., it is sufficient to have an axial range up to 100 mm rearward. In FIG. 1, the coating may be performed in the axial range where a is 0 to 5 mm and b is 50 to 100 mm.

  In the above description, the surface of the sheath of the sheath-type thermocouple is coated with chrome carbide by thermal spraying. Alternatively, a carbide alloy or wear-resistant ceramic may be coated by thermal spraying or vapor deposition. .

  The turbine temperature measuring instrument of the present invention has a short life due to vibration without sacrificing the response speed not only for measuring the high flow gas temperature in the turbine but also for measuring the temperature of other high flow liquid or gas. It can be used as a long-life temperature measuring instrument that is greatly suppressed.

It is a front view of the principal part of the turbine temperature measuring device of the present invention. It is a front view of the conventional turbine temperature measuring device.

Explanation of symbols

2 ... Sheath type thermocouple 1 ... Metal protective tube

Claims (4)

  In a turbine temperature measuring instrument for measuring the temperature of steam in a turbine in which a sheathed thermocouple is inserted into a metal protective tube and the tip of the sheathed thermocouple is protruded from the tip of the metal protective tube, From the position corresponding to the tip of the metal protective tube on the sheath surface to the tip direction, the starting point is any position in the range of 5 mm, and the end point is any position in the length direction from the rear 50 mm to 100 mm. The outer circumference of the sheath is coated with a thickness of 0.07 to 0.2 mm by thermal spraying, and the outer diameter of the sheath is formed in a thin outer diameter of 4 to 8 mm in the range of 10 to 20 mm in the axial direction of the tip. A turbine temperature measuring instrument formed to have an outer diameter of 10 to 20 mm except the tip.   Chromium is applied to the entire circumference in the range starting from any position within the range of 5 mm from the position corresponding to the tip of the metal protective tube on the sheath surface of the sheath type thermocouple to the tip direction and ending in the length direction position of 70 mm rearward. Carbide is coated by thermal spraying to a thickness of 0.07 to 0.2 mm, and the outer diameter of the sheath is formed in a thin outer diameter of 6 mm in the range of 16 mm in the axial direction of the distal end. The turbine temperature measuring device according to claim 1, wherein the turbine temperature measuring device is formed to have an outer diameter.   The turbine temperature measuring device according to claim 1 or 2, wherein a carbide alloy or a wear-resistant ceramic is coated by spraying or vapor deposition instead of chromium carbide. A temperature measuring instrument for measuring a liquid or a gas having a high flow velocity having the configuration according to claim 1, claim 2 or claim 3.

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