WO2015098278A1

WO2015098278A1 - Steam-quality measurement device and steam-quality measurement method

Info

Publication number: WO2015098278A1
Application number: PCT/JP2014/078821
Authority: WO
Inventors: 康博五所尾; 義一西野; 志功田邉; アレクサンドルルクラー
Original assignee: アズビル株式会社
Priority date: 2013-12-27
Filing date: 2014-10-29
Publication date: 2015-07-02
Also published as: JP2015127649A

Abstract

This invention provides a steam-quality measurement device and a steam-quality measurement method that make it possible to accurately measure the quality of wet steam inside a pipe as follows: light emitted by a plurality of light-producing bodies is collected and suitably inputted into a light-guiding part from one end face thereof, said end face being of limited size; the wet steam is suitably exposed to said light; and the quality of the wet steam is measured on the basis of the intensity of light reflected thereby or the absorbance of said wet steam with respect to light passing therethrough. This steam-quality measurement device, which measures the quality of wet steam on the basis of the intensity of light reflected thereby or the absorbance of said wet steam with respect to light passing therethrough, is provided with the following: a light-producing-body array comprising a plurality of light-producing bodies that each produce light; a light-collecting part that collects the light produced by said light-producing bodies; and a first light-guiding part that has a first end face via which the collected light is inputted and a second end face via which the inputted light is outputted to the aforementioned wet steam.

Description

Dryness measuring device and dryness measuring method

The present invention relates to a dryness measuring apparatus and a dryness measuring method.

After water reaches the boiling point, it becomes wet steam in which water vapor gas (gas phase part: saturated steam) and water droplets (liquid phase part: 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, in the invention described in Patent Document 1, in order to measure the dryness at high speed, (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.

In the invention described in the above-mentioned Patent Document 1, light having a plurality of wavelengths is irradiated from one light emitter, and the magnitude relationship between a plurality of measured values of the intensity of light transmitted through the wet steam at each of the plurality of wavelengths irradiated. Based on this, it is disclosed to calculate the dryness of wet steam.

JP 2013-092457 A

However, it is difficult to match the light emitted from multiple light emitters to the same optical path without using a light guide, and it is suitable for one end face of a light guide such as an optical fiber, which is limited in size. Therefore, it is difficult to properly irradiate the wet steam to be measured in the pipe, and it is difficult to accurately measure the dryness.

Therefore, an object of the present invention is to provide a dryness measuring apparatus and a dryness measuring method capable of measuring an accurate dryness.

In order to solve the above-mentioned problem, the dryness measuring apparatus according to the present invention is a dryness measurement that measures the dryness of the wet steam based on the intensity or absorbance of a plurality of lights transmitted or reflected from the wet steam to be measured. An apparatus, a light emitter array having a plurality of light emitters each emitting light, a light collecting portion for collecting a plurality of light emitted by each of the light emitters, and the light collected A first light guide section having a first end face on which a plurality of lights are incident and a second end face on which the plurality of incident lights are emitted to the wet steam.

In order to solve the above-described problem, the dryness measurement method according to the present invention is a dryness measurement method that measures the dryness of the wet steam based on the intensity or absorbance of a plurality of light beams that are transmitted or reflected through the wet steam to be measured. A method for measuring a degree of light, comprising: condensing a plurality of lights; and entering the plurality of collected lights, and emitting the incident light to the wet steam .

According to the present invention, light emitted from a plurality of light emitters is collected and appropriately incident on one end surface of the light guide unit, which has a limited size, and is applied to the wet steam to be measured in the pipe. Accurate dryness can be measured by measuring the dryness of the wet steam based on the intensity or absorbance of light that is appropriately irradiated and transmitted or reflected through the wet steam.

It is a schematic diagram of the dryness measuring apparatus which concerns on embodiment of this invention. It is a schematic diagram of the light-incidence part which concerns on embodiment of this invention. It is a figure explaining the conditions in case the light emitted from the light-emitting body which concerns on embodiment of this invention is projected on the incident side light passage part. It is a schematic diagram of the light-receiving part which concerns on embodiment of this invention.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. 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 χ 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.

(Constitution)
In FIG. 1, the structure of the dryness measuring apparatus 1 in this embodiment is shown. As shown in FIG. 1, the dryness measuring apparatus 1 according to the present embodiment exemplarily includes a light incident part 11, a light receiving part 13, an incident side light guide part 21 (first light guide part), and an emission side light guide. A unit 22 (second light guide unit), an incident side collimator lens 42 (first light focusing unit), an emission side collimator lens 44 (second light focusing unit), and the computer apparatus 100 are configured. Further, the computer apparatus 100 includes a dryness measurement unit 200 as a functional block.

FIG. 2 shows a configuration of the light incident part 11 according to the present embodiment. As illustrated in FIG. 2, the light incident unit 11 is configured to include, for example, a light emitter support 30,

light emitters

32 a, 32 b, and 32 c, and a condenser lens 40 (light collector).

The

light emitters

32a, 32b, and 32c shown in FIG. 2 are light emitting means that each emit light having a single wavelength. For example, the

light emitters

32a, 32b, and 32c are formed of light emitting diodes, and the light emitter 32a emits light having a wavelength that is not absorbed by the liquid phase portion of the wet vapor but absorbed by the gas phase portion. The light emitter 32b emits light having a wavelength that is not absorbed by the vapor phase portion of the wet vapor but is absorbed by the liquid phase portion, and the light emitter 32c is not absorbed by the vapor phase portion and the liquid phase portion of the wet vapor. It is configured to emit light (for reference) having such a wavelength.

In addition, the wavelength of light that is not absorbed by the vapor phase portion of the wet vapor but absorbed by the liquid phase portion is formed by water molecules in the cluster (a combination of water molecules bonded through hydrogen bonds). Set to correlate with the number of hydrogen bonds made. For example, the wavelength of the light emitted from any one of the

light emitters

32a, 32b, and 32c may be 1880 nm at which the absorption peak of a water molecule appears when the number of hydrogen bonds is 0. It may be 1910 nm where the absorption peak of water molecules appears. However, the wavelength of the light emitted from any of the

light emitters

32a, 32b, and 32c may be different from the absorption peak wavelength of water molecules as long as it is within the wavelength band absorbed by water. For example, the wavelength of light emitted from any of the

light emitters

32a, 32b, and 32c may be between 1880 and 1910 nm.

As the light emitters 32a, 32b, and 32c, 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

light emitters

32a, 32b, and 32c do not have to be of the same type, and the light emitter 32a is configured as a light emitting diode, the light emitter 32b is configured as a super luminescent diode, and the light emitter 32a is configured as a light bulb. It is also possible.

The condensing lens 40 shown in FIG. 2 is a means for condensing light emitted from the

light emitters

32a, 32b, and 32c so as to appropriately guide the light to the incident-side light guide unit 21. Specifically, the condensing lens 40 guides the light emitted from the light emitter 32a to the incident opening A1 of the incident side light guide 21 as shown in the light path La, and as shown in the light path Lb, the light emitter 32b. The light emitted from the light-emitting body 32c is guided to the incident opening A1 of the incident-side light guide 21 as shown by the light path Lc. Thus, although the size of the end surface (incidence opening A1) of the incident-side light guide 21 is limited (for example, several μm) by the condenser lens 40, the

light emitters

32a, 32b, and 32c. Can be appropriately guided to the incident-side light guide 21.

The condensing lens 40 is not particularly limited as long as it has a function of condensing light. For example, a convex lens, a dome lens, a circular lens, or the like can be used.

In FIG. 3, the figure explaining the conditions in case the light emitted from the light-emitting

bodies

32a, 32b, and 32c which concerns on embodiment of this invention is projected on the incident side light guide part 21 is shown. As shown in FIG. 3, the light in the light path L emitted from the light emitter 32 is condensed by the condenser lens 40 and guided to the incident-side light guide unit 21. As shown in FIG. 3, for example, when the object (light emitter 32) is installed outside the focal point F, the distance f ₁ from the object plane to the principal point O, and from the principal point O to the image plane. The relationship between the distance f ₂ , the object height a, and the image height b can be expressed by the following relational expression (1).

(A / f ₁ ) = (b / f ₂ ) (1)

Furthermore, as shown in FIG. 3, in order for the light of the light path L emitted from the light emitter 32 to be condensed by the condenser lens 40 and appropriately guided to the incident-side light guide unit 21, the main surface is viewed from the object surface. It is preferable that the distance f ₁ to the point O, the distance f ₂ from the principal point O to the image plane, the object height a, the image height b, and the radius X of the incident-side light guide 21 are as follows. In other words, when the image height b is the same as or smaller than the radius X of the incident-side light guide 21, the light emitted from the light emitter 32 is more appropriately guided to the incident-side light guide 21. Here, the above relationship is defined by the following relational expression (2).

X ≧ b = (a / f ₁ ) · f ₂ (2)

Accordingly, the

light emitters

32a, 32b, and 32c are installed so as to satisfy the relational expression (2).

In addition, the relationship for the light emitted from the

light emitters

32a, 32b, and 32c to be more appropriately guided to the incident-side light guide unit 21 shown in the relational expression (2) is merely an example, and the light emitter There is no particular limitation as long as the light emitted from 32a, 32b, and 32c is appropriately guided to the incident-side light guide unit 21, and the

light emitters

32a, 32b are satisfied so as to satisfy these relationships described above. , And 32c can be installed.

Referring back to FIG. 1, the pipe 20 is a pipe through which wet steam to be measured flows. The incident side collimator lens 42 is connected to the incident side light guide 21. In addition, the incident-side collimator lens 42 prevents a plurality of lights from diverging with respect to a plurality of lights propagated through the incident-side light guide unit 21, and the plurality of lights are appropriately applied to the pipe 20 through which the wet steam to be measured flows. In order to enter, a plurality of lights are focused so as to become parallel lights. The transmissive glass window 50 is an incident window that emits a plurality of lights focused by the incident-side collimator lens 42 into the pipe 20 along the optical path L.

The exit side collimator lens 44 is configured to receive a plurality of light beams transmitted or reflected through the wet vapor inside the pipe 20 through a transmission type glass window 52 installed in the pipe 20. Focus so that it does not diverge.

The incident-side collimator lens 42 and the emission-side collimator lens 44 are not particularly limited as long as a plurality of lights can be converged to become parallel lights, and aberration correction has been performed so as to obtain parallel lights. Any lens can be used.

The exit side light guide unit 22 is connected to the exit side collimator lens 44. Further, the emission side light guide unit 22 is configured to be able to propagate a plurality of lights focused by the emission side collimator lens 44 and to enter the light receiving unit 13 along the optical path L. Further, the end portion of the exit-side light guide portion 22 faces the end portion of the incident-side light guide portion 21 in the radial direction of the pipe 20.

In addition, the incident side light guide part 21 and the emission side light guide part 22 can use a plastic optical fiber made of polymethylmethacrylate resin (PMMA: Poly (methyl methacrylate)), a glass optical fiber made of quartz glass, and the like. However, the present invention is not limited to this as long as a plurality of lights can propagate through the same optical path. In addition, it is not necessary that a plurality of lights can be propagated in the same optical path, and in order to accurately measure the dryness of the wet steam, the intensity or absorbance of the plurality of lights transmitted or reflected by the wet steam is accurately determined. It is sufficient if the optical paths are the same so that they can be measured.

FIG. 4 shows a configuration of the light receiving unit 13 according to the embodiment of the present invention. As shown in FIG. 4, the light receiving unit 13 includes a measuring unit 60 and a signal generating unit 62 as functional blocks.

The measuring unit 60 is a measuring unit that receives the light transmitted through or reflected from the wet vapor in the pipe 20 and measures the intensity I and / or absorbance A of the light. For example, as the measurement unit 60, a photoelectric conversion element such as a photodiode or a phototransistor can be used.

The signal generator 62 is a means for generating a signal corresponding to the intensity I or the absorbance A of the light transmitted or reflected by the wet steam. Specifically, the signal generation unit 62 generates a light intensity signal Sd corresponding to the intensity I of the light transmitted or reflected by the wet steam and outputs the light intensity signal Sd to the computer device 100. Further, as the light receiving unit 13, an optical measuring instrument 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 signal generation unit 62 generates an absorbance signal Sa corresponding to the absorbance of the light transmitted or reflected through the wet steam and outputs the absorbance signal Sa to the computer device 100.

Specifically, the spectrophotometer calculates the absorbance A based on the intensity I of the light that transmits or reflects the wet steam, and outputs it as the absorbance signal Sa. 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, if the incident light intensity I ₀ and the intensity I of the light passing through the wet steam can be measured, the absorbance A is uniquely specified.

Note that the computer apparatus 100 may be configured to input the light intensity signal Sd and calculate the absorbance A based on Expression (3).

Referring back to FIG. 1, among the components described above, the dryness measuring unit 200 is a functional block that is functionally realized by the computer device 100 executing a predetermined software program. The computer device 100 is connected to a data storage device (not shown) including a relation storage unit (not shown). The relationship storage unit stores, for example, the relationship between the light reception intensity I obtained by the light receiving unit 13 and the dryness of the wet steam, which is acquired in advance. The relationship between the received light intensity I and the dryness may be stored as an equation or may be stored as a table.

The relationship storage unit shows the relationship between the light reception intensity (light intensity I) by the light receiving unit 13 and the dryness of the wet steam, and the temperature, pressure, and flow velocity of the wet steam detected by an environmental sensor (not shown). And one or two or more selected from the group of flow rates.

The relationship between the received light intensity I by the light receiving unit 13 and the dryness of the wet steam is measured by measuring the dryness of the wet steam with a conventional dryness meter while heating the wet steam with a boiler or the like, for example. It can be acquired in advance by measuring the intensity I of the light transmitted through the vapor. Conventionally, there are various dryness meters, but when acquiring the relationship, any one of them may be used alone or in combination.

The dryness measuring unit 200 receives, for example, the light intensity signal Sd corresponding to the intensity I of the light transmitted through the wet steam inside the pipe 20 from the light receiving unit 13. In addition, the dryness measurement unit 200 receives one or more detection values selected from the group of the temperature, pressure, flow rate, and flow rate of the wet steam inside the pipe 20 from the environment sensor. Further, the dryness measuring unit 200 is selected from the group of temperature, pressure, flow rate, and flow rate corresponding to one or more detection values selected from the group of wet steam temperature, pressure, flow rate, and flow rate from the relationship storage unit. The relationship between the intensity of light received by the light receiving unit 13 and the dryness of wet steam under one or more conditions is read out.

Here, the dryness measuring unit 200 has one or more conditions selected from the group of temperature, pressure, flow rate, and flow rate that match one or more detection values selected from the group of temperature, pressure, flow rate, and flow rate. When the following relationship is stored in the relationship storage unit, one selected from the group of temperature, pressure, flow rate, and flow rate that matches one or more detection values selected from the group of temperature, pressure, flow rate, and flow rate. Alternatively, a relationship under two or more conditions is read from the relationship storage unit. In addition, the dryness measuring unit 200 is, for example, one or more selected from the group of temperature, pressure, flow rate, and flow rate that matches one or more detection values selected from the group of temperature, pressure, flow rate, and flow rate. If the relationship of the conditions is not stored in the relationship storage unit, select from the group of temperature, pressure, flow rate and flow rate that most closely approximates one or more detection values selected from the group of temperature, pressure, flow rate and flow rate. The relationship under one or more conditions is read from the relationship storage unit.

The dryness measurement unit 200 identifies the dryness value of the wet steam based on the read relationship and the measured value of the received light intensity I. For example, when the relationship is expressed by an expression in which the received light intensity I is an independent variable and the dryness is a dependent variable, the dryness measuring unit 200 measures the received light intensity I as an independent variable of the received light intensity I in the expression. By substituting the value, the dryness value of the wet steam to be measured in the pipe 20 is calculated.

Note that the relationship storage unit may store the relationship between the absorbance A due to the wet steam and the dryness of the wet steam. In this case, as shown in the above formula (3), the dryness measurement unit 200 determines the wetness of the measurement target from the light emission intensity I ₀ of the

light emitters

32a, 32b, and 32c and the light reception intensity I by the light receiver 13. The measured value of the absorbance A by steam is calculated, and the value of the dryness of the wet steam to be measured may be specified based on the relationship between the absorbance A and the dryness and the measured value of the absorbance A.

Also, the correlation between the dryness of the wet steam inside the pipe 20 and the light intensity I transmitted through the wet steam can be changed by the light transmission volume in the wet steam. For example, factors of the change in the light transmission volume include the pipe diameter, the area of the light emitter, the area of the light receiving element, and the like. Therefore, the relationship storage unit may store the correlation between the dryness of the wet steam and the light intensity I transmitted through the wet steam for each light transmission volume of the wet steam. In this case, the dryness measurement unit 200 receives one or more detection values selected from the group of the temperature, pressure, flow rate, and flow rate of the wet steam from the relation storage unit, and the value of the light transmission volume of the wet steam to be measured. The relationship between the received light intensity I and the dryness level corresponding to the above may be read.

The dryness measuring unit 200 may be configured to be able to obtain the amount of saturated steam and the amount of saturated water in the process of measuring the dryness based on the light intensity I or the absorbance A. .

(Operation)
Next, the operation of this embodiment will be described.
First, as shown in FIG. 2, when measuring the dryness of the wet steam while the wet steam is flowing in the pipe 20, the

light emitters

32 a, 32 b, and 32 c of the light incident portion 11 emit light. Next, the condensing lens 40 (condensing part) of the light incident part 11 condenses so that the emitted several light may be guide | induced to the incident side light guide part 21 appropriately. Next, the light condensed by the condenser lens 40 is guided to the pipe 20 by the incident side light guide 21 (first light guide).

Next, as shown in FIG. 1, the plurality of lights guided through the incident-side light guide unit 21 along the same optical path are converged to become parallel light by the incident-side collimator lens 42 (first light focusing unit). Then, the light enters the pipe 20 through the transmissive glass window 50 (light path L).

Next, the plurality of lights that have entered the pipe 20 transmit or reflect the wet vapor to be measured. Next, the plurality of lights that have transmitted or reflected the wet steam inside the pipe 20 are emitted outside the pipe 20 through the transmission type glass window 52 installed in the pipe 20. Then, after the plurality of lights are emitted to the outside of the pipe 20, the plurality of lights are converged by the emission side collimator lens 44 (second light focusing unit) so as not to diverge.

Next, the exit-side light guide unit 22 (second light guide unit) guides the plurality of lights focused by the exit-side collimator lens 44 so as to have the same optical path, and the light-receiving unit 13 along the optical path L. To enter.

Next, as shown in FIG. 4, the measurement unit 60 of the light receiving unit 13 receives the light transmitted or reflected through the wet vapor in the pipe 20 and measures the light intensity I and / or absorbance A. Next, the signal generation unit 62 generates a light intensity signal Sd corresponding to the intensity I of the light transmitted or reflected through the wet steam, and the absorbance signal Sa corresponding to the absorbance A of the light transmitted or reflected through the wet steam. Is generated.

Next, returning to FIG. 1, the light receiving unit 13 outputs a light intensity signal Sd corresponding to the intensity I of the light transmitted or reflected through the wet steam to the computer apparatus 100. In addition, the light receiving unit 12 outputs an absorbance signal Sa corresponding to the absorbance A of light transmitted or reflected through the wet steam to the computer device 100.

Next, the dryness measurement unit 200 selects one or two selected from the group of temperature, pressure, flow rate, and flow rate that matches (or approximates) one or more detection values selected from the group of temperature, pressure, flow rate, and flow rate. The relationship between the received light intensity I under the above conditions and the dryness of the wet steam is read from the relation storage unit. Based on the read relationship and the measured value of the received light intensity I, the dryness of the wet steam is measured.

(effect)
According to the present embodiment described above, the light irradiated from a plurality of light emitters is collected, and the measurement target in the pipe is appropriately incident on one end surface of the light guide unit having a limited size. By accurately irradiating the wet steam, and measuring the dryness of the wet steam based on the intensity or absorbance of the light transmitted or reflected by the wet steam, the accurate dryness can be measured.

(Other embodiments)
The embodiment described above is merely an example, and there is no intention of excluding various modifications and technical applications that are not explicitly described above. That is, the present invention can be implemented with various modifications without departing from the spirit of the present invention.

DESCRIPTION OF SYMBOLS 1 Dryness measuring apparatus 11 Light incident part 13 Light receiving part 20 Piping 21 Incident side light guide part 22 Emission side

light guide part

32, 32a, 32b, 32c Light emitter 40 Condensing lens 42 Incident side collimator lens 44 Emission side collimator lens 100 Computer device 200 Dryness measuring unit

Claims

A dryness measuring device that measures the dryness of the wet steam based on the intensity or absorbance of a plurality of light beams transmitted or reflected from the wet steam to be measured,
A light emitter array having a plurality of light emitters, each emitting light;
A condensing unit that condenses a plurality of light emitted by each of the plurality of light emitters;
A first light guide section having a first end face for entering the collected light and a second end face for emitting the entered light to the wet steam.
Dryness measuring device.
A first light focusing section for focusing the plurality of lights emitted by the first light guide section so as to be parallel light;
The dryness measuring apparatus according to claim 1.
A second light focusing portion for focusing a plurality of light beams transmitted or reflected by the wet steam;
A second light guide part having a third end face for entering the plurality of lights focused by the second light focusing part and a fourth end face for emitting the plurality of incident lights;
The dryness measuring apparatus according to claim 1 or 2.
A dryness measurement method that measures the dryness of the wet steam based on the intensity or absorbance of a plurality of light beams transmitted or reflected from the wet steam to be measured,
Condensing multiple lights,
Injecting the collected plurality of lights, and emitting the entered plurality of lights to the wet steam,
Dryness measurement method.