JP6379007B2 - Piping and dryness measuring device - Google Patents

Description

  The present invention relates to a pipe and a dryness measuring apparatus including the pipe.

  After the water reaches the boiling point, it becomes wet steam in which water vapor gas (gas phase portion: saturated steam) and water droplets (liquid phase portion: saturated water) are mixed. Here, the weight ratio of the water vapor gas to the wet steam is referred to as “dryness”. For example, if water vapor gas and water droplets are present in half, the dryness is 0.5. Moreover, when there is no water droplet and only water vapor gas is present, the dryness is 1.0. In the heat exchanger or the like, the dryness of the wet steam is set to 1.0 from the viewpoint of effectively utilizing the sensible heat and latent heat possessed by the wet steam, and preventing the corrosion of the turbine blade in the steam turbine. It is desired to make the state close to. Therefore, various methods for measuring the dryness have been proposed.

  For example, the invention described in Patent Document 1 uses the fact that there is no change in the total enthalpy before and after the pressure control valve provided in the pipe, and based on the wet steam flow and pressure before and after the pressure control valve, the saturated steam table It is related with the technique which calculates | requires saturated water enthalpy and saturated vapor | steam enthalpy using, and calculates dryness.

  In addition, in order to measure the dryness at high speed, the invention described in Patent Document 2 includes (a) a light emitter that irradiates light to wet steam, (b) a light receiving element that receives light transmitted through the wet steam, and ( c) an environmental sensor that measures the temperature or pressure of the wet steam; and (d) a relation storage unit that stores the relationship between the intensity of light transmitted through the wet steam and the dryness of the wet steam for each temperature or pressure. (E) a dryness degree provided with a dryness specifying unit for specifying a dryness value of wet steam based on a measured value of light intensity by a light receiving element, a measured value of temperature or pressure by an environmental sensor, and the relationship It relates to a measuring device.

JP-A-8-312908 JP2013-092457A

  However, in the inventions described in Patent Documents 1 and 2, if the pipe diameter is increased, the optical path length from the incident end face to the exit end face in the pipe is increased. Therefore, depending on the size of the pipe diameter, it is attenuated by passing steam. In some cases, the intensity of the received light is lower than the detection sensitivity of the light receiving unit, and the intensity of the light attenuated in the light receiving unit may not be measured.

  Accordingly, an object of the present invention is to provide a pipe capable of reliably measuring the intensity of light passing through steam regardless of the pipe diameter.

In order to solve the above-described problem, a pipe according to one aspect of the present invention is a pipe through which steam flows , a light incident section that causes light emitted from a light emitting section to enter the steam from an incident end surface, and a transmission through the steam. Or a light emitting part that emits the reflected light from the emission end face toward the light receiving part, and the intensity of the light attenuated by passing through the vapor is equal to or higher than the minimum light intensity measurable by the light receiving part. The optical path length from the incident end surface to the exit end surface is adjusted so that at least one of the light incident portion and the light exit portion has a convex three-dimensional shape, and a convex shape with a flat top portion. A transmissive glass is provided, and the top portion projects toward the inside of the pipe so that the optical path length is smaller than the diameter of the pipe .

  In order to solve the above problems, a dryness measuring apparatus according to an aspect of the present invention measures the dryness of the vapor based on the pipe and the intensity or absorbance of the light emitted by the light emitting unit. And a dryness measuring unit.

  In the present invention, the “part” does not simply mean a physical means, but includes a case where the function of the “part” is realized by software. Also, even if the functions of one “unit” or device are realized by two or more physical means or devices, the functions of two or more “units” or devices are realized by one physical means or device. May be.

  According to the present invention, since the optical path length is adjusted so that the intensity of the light attenuated by passing through the vapor is equal to or higher than the minimum light intensity measurable by the light receiving unit, the pipe diameter can be any size. However, it is possible to provide a pipe capable of reliably measuring the intensity of light passing through the vapor.

It is the figure which showed correlation with the intensity | strength of light and optical path length. It is a schematic diagram of the dryness measuring apparatus which concerns on 1st Embodiment of this invention. It is a schematic diagram of the dryness measuring apparatus which concerns on 2nd Embodiment of this invention. It is a schematic diagram of the dryness measuring apparatus which concerns on 3rd Embodiment of this invention. It is a schematic diagram of the dryness measuring apparatus which concerns on 4th Embodiment of this invention. It is a schematic diagram of the dryness measuring apparatus which concerns on 5th Embodiment of this invention. It is a schematic diagram of the dryness measuring apparatus which concerns on 6th Embodiment of this invention.

  Embodiments of the present invention will be described below with reference to the drawings. However, the embodiment described below is merely an example, and there is no intention to exclude various modifications and technical applications that are not explicitly described below. In other words, the present invention can be implemented with various modifications (combining the embodiments, etc.) without departing from the spirit of the present invention. In the following description of the drawings, the same or similar parts are denoted by the same or similar reference numerals. The drawings are schematic and do not necessarily match actual dimensions and ratios. In some cases, the dimensional relationships and ratios may be different between the drawings.

(Definition)
The main terms used in this specification are defined as follows.
“Vapor”: In each embodiment, it means water vapor, but it is not limited to water vapor as long as it is a vapor of a substance that is in a two-phase state of a gas phase portion and a liquid phase portion.
“Dryness”: Refers to the weight ratio of the gas phase portion in the steam. There is a relationship of dryness [%] = 100 [%] − wetness [%].
“Wet steam”: refers to steam having a dryness X of 0 to 100%.
“Saturated steam”: refers to the gas phase portion of wet steam. Also called dry saturated steam (saturated dry steam).
“Saturated water”: refers to the liquid phase of wet steam.
“Light intensity” (light intensity): A physical quantity indicating the intensity of light (electromagnetic wave), and there is no limitation on its name or unit. For example, these are physical quantities that are mutually different but can be converted into each other, such as radiation intensity, luminous intensity, and photon flux density.
“Absorbance”: A dimensionless amount indicating how much light intensity is weakened when light passes through wet steam, and is also called optical density. Absorbance includes not only the absorption of light but also the case where the intensity of light is weakened by scattering and reflection.

(Principle explanation)
The principle of the present invention will be described with reference to FIG. FIG. 1 shows the intensity of light and the optical path length (from the incident end face A1 in FIGS. 2 to 7) measured by the light receiving unit (the light receiving unit 13 in FIGS. 2 to 7) of the dryness measuring apparatus according to the embodiment of the present invention. It is the figure which illustrated correlation with length to injection end face A2: R).

  In general, when light passes through the wet steam, it is absorbed and attenuated by the wet steam. Therefore, the present inventor exemplarily uses steam having a dryness of 100%, steam having a dryness of 90% to less than 100%, and steam having a dryness of 80% to less than 90%, depending on the optical path length. As a result of examining how the intensity of light measured at the light receiving portion changes, the result shown in FIG. 1 was obtained.

  That is, as shown in FIG. 1, the light path is 100% dry, vapor with a dryness of 90% to less than 100%, and steam with a dryness of 80% to less than 90%. It has been found that the intensity of light measured by the light receiving portion decreases as the length increases. Further, regarding the light intensity decrease rate, the decrease rate increases in the order of steam having a dryness of 80% to less than 90%, steam having a dryness of 90% to less than 100%, and steam having a dryness of 100%. Furthermore, when the vapor with a dryness of 80% or more and less than 90% and the vapor with a dryness of 90% or more and less than 100% are used, the reduction rate of the light intensity is relatively high, and when the optical path length is 100 mm or more, It has been found that the light intensity is particularly reduced. It has been clarified that the light intensity greatly attenuated in this way may be lower than the detection sensitivity of the light receiving unit, and the light intensity may not be measured in the light receiving unit.

  Here, normally, if the pipe diameter of the pipe through which steam flows increases, the optical path length becomes longer. Therefore, depending on the pipe diameter, the intensity of light attenuated by passing through the steam may affect the detection sensitivity of the light receiving unit. In some cases, the intensity of the attenuated light may not be measured at the light receiving unit.

  Therefore, by using a pipe whose optical path length is adjusted in advance so that the intensity of the light attenuated by passing through the vapor is equal to or higher than the minimum light intensity measurable by the light receiving unit, the pipe diameter can be any size. However, the intensity of light passing through the vapor can be reliably measured.

Each embodiment of the present invention will be described below in view of the above principle.
In the first embodiment, a dryness measuring device in which an incident end face projects into a pipe in order to adjust an optical path length in a horizontal pipe (a pipe in which the axial direction of the pipe is parallel to the horizontal direction) will be described.
In the second embodiment, a dryness measuring device in which the emission end face projects into the pipe in order to adjust the optical path length in the horizontal pipe will be described.
In the third embodiment, in the horizontal pipe, the incident end face protrudes into the pipe to adjust the optical path length, the incident side light guide section approaches the incident end face, and the emission side light guide section approaches the exit end face. A dryness measuring apparatus will be described.
In the fourth embodiment, a dryness measuring apparatus including a convex transmission glass on the light incident side in the pipe in order to adjust the optical path length in the horizontal pipe will be described.
In the fifth embodiment, a dryness measurement apparatus in which an incident end face protrudes into a pipe in order to adjust an optical path length in a vertical pipe (a pipe in which the axial direction of the pipe is parallel to the vertical direction) will be described.
In the sixth embodiment, a dryness measurement device in which an emission end face protrudes into a pipe in order to adjust an optical path length in a vertical pipe will be described.

(First embodiment)
1st Embodiment is related with the dryness measuring apparatus in which incident end surface protrudes in the inside of piping in order to adjust optical path length in horizontal piping.

  FIG. 2 is a schematic diagram of the dryness measuring apparatus according to the first embodiment of the present invention. As shown in FIG. 2, the dryness measuring apparatus 1 </ b> A according to this embodiment illustratively includes a light emitting unit 11, a light receiving unit 13, an incident side tube 22, an exit side tube 24, and an incident side light guide unit 31 (first A light guide unit), an incident side collimator lens 33 (first light focusing unit), an emission side collimator lens 35 (second light focusing unit), an emission side light guiding unit 37 (second light guiding unit), and the computer apparatus 100. It is prepared for. Further, the computer apparatus 100 includes a dryness measurement unit 200 as a functional block.

  The light emitting unit 11 is a light emitting unit that emits light having a predetermined wavelength. For example, as the light emitting unit 11, a light emitting diode, a super luminescent diode, a semiconductor laser, a laser oscillator, a fluorescent discharge tube, a low pressure mercury lamp, a xenon lamp, a light bulb, and the like can be used.

  The incident side tube 22 and the incident side light guide 31 may be connected to the light emitting unit 11. The incident side tube 22 is provided through the side wall of the pipe 20. The incident-side light guide unit 31 enters the light emitted from the light emitting unit 11 at the first end surface B1, and emits the incident light at the second end surface B2. Further, the incident side light guide unit 31 is connected to the incident side collimator lens 33. The incident-side collimator lens 33 prevents the light emitted from the second end face B2 of the incident-side light guide section 31 from diverging, so that the light is appropriately incident on the pipe 20 through which the wet steam to be measured flows. To focus the light.

  The transmissive glass 26 </ b> A (light incident portion) is an incident window that allows the light focused by the incident-side collimator lens 33 to enter the vapor in the pipe 20 from the incident end surface A <b> 1 along the optical path L.

  The transmissive glass 26 </ b> B (light emitting part) is an emission window that introduces light that has transmitted or reflected wet steam inside the pipe 20 from the emission end face A <b> 2 along the optical path L and emits it toward the light receiving part 13. . In addition, although glass provided with heat resistance, pressure | voltage resistance, or corrosion resistance etc. is mentioned as transmissive glass 26A, 26B, If it can permeate | transmit light, it will not be limited to these.

Here, the optical path length R ₁ , which is the length from the incident end face A1 to the exit end face A2, is the lowest light intensity that can be measured by the light receiving unit 13 to be described later, the intensity of light attenuated by passing through the vapor in the pipe 20. It is adjusted so that it may become the above. Specifically, the pipe 20 is configured such that the incident end face A1 protrudes into the pipe 20 so that the optical path length is smaller than the pipe diameter.

For example, the relationship between the light intensity attenuated by passing through the vapor in the pipe 20 and immediately before entering the light receiving unit 13 and the minimum light intensity I _L that can be measured by the light receiving unit 13 is as follows. It can be described as a relational expression as shown in equation (1).

Light intensity I ≧ minimum light intensity I _L that can be measured by the light receiving unit 13 (1)

Further, light attenuation also occurs in the incident-side light guide unit 31 and the incident-side collimator lens 33, as well as in an emission-side collimator lens 35 and an emission-side light guide unit 37 described later. Therefore, the attenuation in at least one part / lens of the incident-side light guide unit 31, the incident-side collimator lens 33, the emission-side collimator lens 35, and the emission-side light guide unit 37 is attenuated by passing the vapor in the pipe 20. In addition, the relationship between the light intensity I ₁ immediately before entering the light receiving unit 13 and the minimum light intensity I _L that can be measured by the light receiving unit 13 in the case of further consideration is as shown in the following equation (2). Can be described as:

Light intensity I ₁ ≧ Minimum light intensity I _L that can be measured by the light receiving unit 13 (2)

Thus, the optical path length R ₁ is adjusted so that the light intensities I and I ₁ attenuated by passing through the vapor in the pipe 20 are not less than the minimum light intensity measurable by the light receiving unit 13. . The optical path length R ₁ may be adjusted according to the presence / absence of the entrance-side collimator lens 33 and the exit-side collimator lens 35, the shape of each lens, the property of each lens, and the like.

  Further, the pipe 20 may be connected with an emission side tube 24 into which light transmitted through or reflected from the wet vapor inside the pipe 20 enters through the transmission glass 26B. The injection side cylinder 22 is provided through the side wall of the pipe 20.

  The exit side collimator lens 35 focuses the light transmitted or reflected through the wet vapor inside the pipe 20 so that the light does not diverge when irradiated through the transmission glass 26B. The exit side collimator lens 35 is connected to the exit side light guide 37. The exit-side light guide 37 enters the light focused by the exit-side collimator lens 35 at the third end face C1, and emits the incident light toward the light receiving section 13 at the fourth end face C2.

  The incident side tube 22 and the emission side tube 24 may be separate from the pipe 20 or may be integrated with the pipe 20. The incident-side collimator lens 33 and the emission-side collimator lens 35 are not particularly limited as long as they can focus light, and lenses having any shape and material whose aberrations are corrected so that the light can be focused. It can be used.

  Furthermore, the incident side light guide unit 31 and the emission side light guide unit 37 can use a plastic optical fiber made of polymethyl methacrylate resin (PMMA), a glass optical fiber made of quartz glass, and the like. However, the present invention is not limited to this as long as light can propagate through the same optical path. In addition, light does not have to be able to propagate in the exact same optical path, and in order to accurately measure the dryness of wet steam, it is possible to accurately measure the intensity or absorbance of a plurality of lights transmitted or reflected through wet steam. As long as the optical paths are the same.

  Furthermore, the light emitting unit 11 may be provided close to the side wall of the pipe 20 without providing the incident side tube 22, and the light receiving unit 13 may be provided close to the side wall of the pipe 20 without providing the emission side tube 24. Also good.

The light receiving unit 13 is a measuring unit that receives light transmitted or reflected through the wet vapor in the pipe 20 and measures the intensity and / or absorbance of the light. As described above, the light receiving unit 13 is adjusted so that the optical path length R ₁ is equal to or higher than the minimum light intensity that can be measured by the light receiving unit 13 as the light intensity attenuated by passing through the vapor in the pipe 20. Therefore, the intensity of the light can be measured. For example, as the light receiving unit 13, a photoelectric conversion element such as a photodiode or a phototransistor can be used. The light receiving unit 13 outputs a light intensity signal Sd corresponding to the intensity of light transmitted or reflected through the wet steam to the computer apparatus 100.

  Further, as the light receiving unit 13, an optical measuring device such as a spectrophotometer that can obtain an output corresponding to the intensity and / or absorbance of light can be applied. In this case, the spectrophotometer may output an absorbance signal corresponding to the absorbance of light transmitted or reflected through the wet steam to the computer apparatus 100.

When a spectrophotometer is used as the light receiving unit 13, specifically, the spectrophotometer calculates the absorbance based on the intensity of the light that transmits or reflects the wet vapor, and outputs it as an absorbance signal. Here, the absorbance A is defined as in Expression (3) where I ₀ is the incident light intensity and I is the intensity of the received light.

Absorbance A = −log ₁₀ (I / I ₀ ) (3)

From the above, the absorbance A can be uniquely specified if the intensity of light transmitted through the wet steam can be measured.

  Instead of outputting the absorbance A to the light receiving unit 13, the computer apparatus 100 may be configured to input the light intensity signal Sd including the light intensity and calculate the absorbance A based on the equation (3). .

  In the present embodiment, only one light receiving unit 13 is provided, but there may be two or more light receiving units 13, and the number of light receiving units 13 is not particularly limited. Furthermore, any configuration can be applied to the light receiving unit 13 as long as it can output a physical quantity corresponding to the intensity of light that transmits or reflects wet steam.

  The computer device 100 is a computing unit that functions as the dryness measurement unit 200 of the present invention, which measures the dryness of wet steam based on the measured light intensity or absorbance. The computer device 100 includes, as an example, a CPU (Central Processing Unit), a RAM (Random Access Memory), a ROM (Read Only Memory), and an interface (I / F) circuit, which are not illustrated. . For example, an external storage device (not shown) is connected to the computer device 100. In the external storage device, for example, a software program for causing the computer device 100 to execute the dryness measuring method according to the present invention is stored. The computer apparatus 100 functionally implements the dryness measurement unit 200 by reading a software program related to the dryness measurement method according to the present invention stored in an external storage device or the like into the RAM and executing it.

  The dryness measuring unit 200 includes the light intensity measured by the light receiving unit 13, the area of the vapor phase portion and the liquid phase portion of the wet vapor corresponding to the intensity of the light, and the vapor phase portion and the liquid phase portion of the wet vapor. And the difference in density between the vapor phase portion and the liquid phase portion of the wet steam, and the dryness X of the wet steam is calculated. Then, the dryness measuring unit 200 outputs the measured dryness X.

  In addition, the dryness measuring unit 200 includes the light intensity measured by the light receiving unit 13 described above, the area of the vapor phase portion of the wet vapor and the area of the liquid phase portion corresponding to the intensity of the light, and the vapor phase portion of the wet vapor. It is not necessary to calculate the wet steam dryness X based on the speed difference between the liquid phase part and the density difference between the gas phase part and the liquid phase part of the wet steam. It may be used to calculate the dryness X of the wet steam. Further, the dryness measuring unit 200 calculates the absorbance of the wet steam with reference to the light intensity signal Sd based on the measured light intensity, and calculates the dryness X of the wet steam based on the absorbance. Good.

  The dryness measuring unit 200 calculates the dryness X based on the light intensity received by the light receiving unit 13 or the absorbance A obtained based on the incident light intensity and the light received by the light receiving unit 13. It may be configured such that the amount of saturated steam and the amount of saturated water can be obtained in the process of measurement.

According to the first embodiment, in the horizontal pipe, the optical path length R ₁ is adjusted so that the intensity of light attenuated by passing through the vapor is equal to or higher than the minimum light intensity measurable by the light receiving unit 13. It is possible to provide a pipe capable of reliably measuring the intensity of light passing through the vapor regardless of the pipe diameter.

(Second Embodiment)
The second embodiment relates to a dryness measuring device in which an emission end face projects into a pipe in order to adjust an optical path length in a horizontal pipe. Below, a different point from 1st Embodiment is demonstrated especially and description is abbreviate | omitted about another point.

FIG. 3 is a schematic diagram of a dryness measuring apparatus according to the second embodiment of the present invention. As shown in FIG. 3, in the dryness measuring apparatus 1 </ b> B according to the present embodiment, the optical path length R ₂ that is the length from the incident end face A < _b > 1 to the exit end face A < _b > ₂ is attenuated by passing through the vapor in the pipe 20. The light intensity is adjusted to be equal to or higher than the minimum light intensity measurable by the light receiving unit 13. Specifically, the pipe 20 is configured such that the emission end face A2 protrudes into the pipe 20 so that the optical path length is smaller than the pipe diameter.

According to the second embodiment, in addition to the effects of the first embodiment, structural or other convenient arrangement of members of the horizontal pipe, you can not adjust the optical path length R ₂ by altering the position of the incident end face A1 For example, the optical path length can be adjusted even when there is a restriction that the incident end face A1 cannot protrude into the inside 20 of the pipe 20.

(Third embodiment)
In the third embodiment, in a horizontal pipe, the incident end face protrudes into the pipe in order to adjust the optical path length, the incident side light guide section approaches the incident end face, and the emission side light guide section approaches the exit end face. It relates to a dryness measuring apparatus. Below, a different point from the said embodiment is demonstrated especially and description is abbreviate | omitted about another point.

  FIG. 4 is a schematic diagram of a dryness measuring apparatus according to a third embodiment of the present invention. As shown in FIG. 4, the incident-side light guide unit 31 of the dryness measuring apparatus 1 </ b> C according to this embodiment is configured so that the incident-side collimator lens 33 connected to the incident-side light guide unit 31 is in contact with the transmission glass 26 </ b> A. Or it is comprised so that it may approach, so that it contacts, although it is not touching (1st structure). Further, the exit-side light guide unit 37 of the dryness measuring apparatus 1C according to the present embodiment also touches or contacts the exit-side collimator lens 35 connected to the exit-side light guide unit 37 with the transmission glass 26B. Although it is not, it is comprised so that it may approach so that it may contact (2nd structure).

Further, as shown in FIG. 4, in the dryness measuring apparatus 1C according to the present embodiment, the optical path length R ₃ that is the length from the incident end surface A1 to the exit end surface A2 passes through the steam in the pipe 20. Adjustment is made so that the intensity of the attenuated light is equal to or higher than the minimum light intensity measurable by the light receiving unit 13. Specifically, the pipe 20, such that the optical path length R ₃ is smaller than the pipe diameter, the exit end face A2 is configured to protrude into the interior of the pipe 20.

  Note that the dryness measuring apparatus 1C according to the present embodiment may be configured to include at least one of the first configuration and the second configuration. In the present embodiment, the pipe 20 in which the incident end face A1 protrudes into the pipe 20 has been described in order to adjust the optical path length. Instead of the incident end face A1 protruding into the pipe 20, the exit end face A2 is used. May protrude into the pipe 20.

  According to the third embodiment, in addition to the effects of the first embodiment, it is possible to more appropriately prevent the light from being emitted before the light from the light emitting unit 11 reaches the light receiving unit 13, The intensity of light can be measured more accurately.

(Fourth embodiment)
4th Embodiment is related with the dryness measuring apparatus provided with convex type | mold transmission glass in the incident side of light in piping, in order to adjust optical path length in horizontal piping. Below, a different point from the said embodiment is demonstrated especially and description is abbreviate | omitted about another point.

FIG. 5 is a schematic diagram of a dryness measuring apparatus according to a fourth embodiment of the present invention. In the dryness measuring apparatuses 1A to 1C of the above embodiment, the transmission glass 26A has a plate-like three-dimensional shape (see FIGS. 2 to 4), but in the dryness measuring apparatus 1D according to the present embodiment. Instead of the transmissive glass 26A, a glass having a convex three-dimensional shape, that is, a convex transmissive glass 29 is employed. The optical path length R ₄ , which is the length from the incident end face A 1 to the exit end face A 2, is equal to or greater than the minimum light intensity that can be measured by the light receiving unit 13 as the light attenuated by passing through the vapor in the pipe 20. So that it is adjusted. Specifically, the pipe 20 is configured such that the incident end face A1 protrudes into the pipe 20 so that the optical path length R ₄ is smaller than the pipe diameter.

  In addition, you may employ | adopt convex transmission glass instead of the transmission glass 26B. Moreover, you may employ | adopt convex transmission glass instead of both transmission glass 26A and 26B. Further, the transmissive glass can have various three-dimensional shapes, for example, a three-dimensional shape such as a truncated cone shape.

  Also in the dryness measuring apparatus 1D according to the present embodiment, the incident-side light guide unit 31, the exit-side light guide unit 37, and the incident-side collimator lens are the same as the dryness measurement apparatuses 1A to 1C of the above-described embodiment. 33 and the exit side collimator lens 35 may be provided.

According to the fourth embodiment, in addition to the effects of the first embodiment, the optical path length R ₄ can be adjusted by the shape of the convex transmission glass. The manufacturing cost can also be suppressed.

(Fifth embodiment)
The fifth embodiment relates to a dryness measuring apparatus in which an incident end face projects into the pipe in order to adjust the optical path length in the vertical pipe. Below, a different point from the said embodiment is demonstrated especially and description is abbreviate | omitted about another point. In the first embodiment to the fourth embodiment, the horizontal pipe has been described. In the present embodiment and the sixth embodiment, the vertical pipe will be described.

FIG. 6 is a schematic diagram of a dryness measuring apparatus according to a fifth embodiment of the present invention. As shown in FIG. 6, in the dryness measuring apparatus 1 </ b> E according to the present embodiment, the pipe 20 is a vertical pipe, and the optical path length R ₅ that is the length from the incident end face A <b> 1 to the exit end face A <b> 2 is within the pipe 20. The light intensity attenuated by passing through the vapor is adjusted to be equal to or higher than the minimum light intensity measurable by the light receiving unit 13. Specifically, the pipe 20 is configured such that the incident end face A1 protrudes into the pipe 20 so that the optical path length R ₅ is smaller than the pipe diameter.

According to the fifth embodiment, in the vertical pipe, the optical path length R ₅ is adjusted so that the intensity of light attenuated by passing through the steam is equal to or higher than the minimum light intensity measurable by the light receiving unit 13. It is possible to provide a pipe capable of reliably measuring the intensity of light passing through the vapor regardless of the pipe diameter.

(Sixth embodiment)
The sixth embodiment relates to a dryness measuring apparatus in which an emission end face projects into the pipe in order to adjust the optical path length in the vertical pipe. Below, a different point from the said embodiment is demonstrated especially and description is abbreviate | omitted about another point.

FIG. 7 is a schematic diagram of a dryness measuring apparatus according to a sixth embodiment of the present invention. As shown in FIG. 7, in the dryness measuring apparatus 1 </ b> F according to the present embodiment, the pipe 20 is a vertical pipe, and the optical path length R ₆ that is the length from the incident end face A <b> 1 to the exit end face A <b> 2 is within the pipe 20. The light intensity attenuated by passing through the vapor is adjusted so as to be equal to or higher than the minimum light intensity measurable by the light receiving unit 13. Specifically, the pipe 20 is configured such that the exit end face A2 protrudes into the pipe 20 so that the optical path length R ₆ is smaller than the pipe diameter.

According to the sixth embodiment, in addition to the effects of the fifth embodiment, the optical path length R ₆ cannot be adjusted by changing the position of the incident end face A1 due to the structure of the vertical piping or the arrangement of other members. For example, the optical path length can be adjusted even when there is a restriction that the incident end face A1 cannot protrude into the inside 20 of the pipe 20.

(Other embodiments)
Each of the above embodiments is for facilitating the understanding of the present invention, and is not intended to limit the present invention. The present invention can be changed / improved (for example, by combining the embodiments, omitting a part of the configuration of each embodiment) without departing from the spirit thereof, and the present invention includes equivalents thereof. It is. The present invention is not limited to the first to sixth embodiments described above, and can be combined in various ways, can be applied in a modified manner, and each component included in each embodiment can also be applied. It can be combined in various ways and can be applied in a modified manner.

  In addition, in order to adjust the optical path length so that the intensity of light attenuated by passing through the vapor is equal to or higher than the minimum light intensity measurable by the light receiving unit 13, the shape of the pipe 20 itself may be modified. For example, the optical path length may be adjusted by changing the shape of a part of the pipe 20 so as to protrude into the pipe 20.

  Further, the pipe 20 may be configured such that both the incident end face A1 and the exit end face A2 protrude into the pipe 20 in order to adjust the optical path length.

DESCRIPTION OF SYMBOLS 1 Dryness measuring apparatus 11 Light emission part 13 Light reception part 20 Piping 22 Incident side cylinder 24 Emission side cylinder 26A Transmission glass 26B Transmission glass 29 Convex type transmission glass 31 Incident side light guide part 33 Incident side collimator lens 35 Emission side collimator lens 37 Emission Side light guide unit 100 Computer device 200 Dryness measuring unit A1 Incidence end surface A2 Exit end surface B1 First end surface B2 Second end surface C1 Third end surface C2 Fourth end surface

Claims (4)

A pipe through which steam flows,
A light incident part for causing the light emitted from the light emitting part to enter the vapor from the incident end face;
A light emitting part that emits light transmitted through or reflected from the vapor toward the light receiving part from the emission end face; and
With
As the intensity of the light attenuation is measurable minimum of light intensity by the light receiving portion by passing through the vapor, the optical path length from the incident end face to the exit end face is adjusted,
At least one of the light incident part and the light emitting part includes a convex transmissive glass having a convex three-dimensional shape and having a flat top.
The top portion protrudes toward the inside of the pipe so that the optical path length is smaller than the diameter of the pipe.
Plumbing. Piping according to claim 1;
A dryness measurement unit that measures the dryness of the vapor based on the intensity or absorbance of the light received by the light receiving unit;
A dryness measuring device. The light incident part is
A first light guide part having a first end face on which the light emitted from the light emitting part is incident and a second end face on which the incident light is emitted;
A first light focusing section connected to the first light guiding section and focusing the light emitted by the first light guiding section,
The dryness measuring apparatus according to claim 2. The light emitting part is
A second light focusing portion for focusing the light that has passed through the vapor;
A second light guide section connected to the second light focusing section and having a third end face for entering the light focused by the second light focusing section and a fourth end face for emitting the incident light; Comprising
The dryness measuring apparatus according to claim 2 or 3.

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