1. Method for determining steam quality comprising the steps of:
frequency-scanning a laser beam emitted from a narrow linewidth laser along a path through steam in a steam chamber to excite a molecular transition in the steam, the steam having a water vapor phase and a liquid water phase;
determining a total number of water vapor molecules in the path of the laser beam based on a normalized peak absorption amplitude of the water vapor phase as the laser beam passes through the steam;
determining a total number of liquid water molecules in the laser beam path based on a shift in dc level of a peak absorption amplitude of the water vapor phase from a dc level of a reference peak absorption amplitude;
determining specific volumes of the water vapor phase and the liquid water phase in the steam using the total numbers of water vapor and liquid water molecules; and
calculating quality of the steam based on the specific volumes of water vapor phase and liquid water phase in the steam.
2. Method as in claim 1 wherein the narrow linewidth laser is coupled with optic fibers for laser beam transmission and conditioning.
3. Method for determining steam quality comprising the steps of:
frequency-scanning a laser beam emitted from a narrow linewidth laser along a path through steam in a steam chamber to excite a molecular transition in the steam, the steam having a water vapor phase and a liquid water phase;
measuring peak absorption amplitude of the water vapor phase as the laser beam passes through the steam;
normalizing the peak absorption amplitude of the water vapor phase using a reference peak absorption amplitude to determine a normalized peak absorption amplitude;
determining a total number of water vapor molecules in the path of the laser beam based on the normalized peak absorption amplitude;
determining a dc level of the peak absorption amplitude of the water vapor phase;
determining a dc level of the reference peak absorption amplitude;
normalizing the dc level of the peak absorption amplitude of the water vapor phase with the de level of the reference peak absorption amplitude to determine a shift in the dc level of the peak absorption amplitude of the water vapor phase from the dc level of the reference peak absorption amplitude;
determining a total number of water molecules in the laser beam path based on the shift in the de level of the peak absorption amplitude of the water vapor phase using Beer Lambert’s law;
determining specific volumes of the water vapor phase and liquid water phase in the steam using the total numbers of water vapor and liquid water molecules; and
calculating quality of the steam based on the specific volumes of the water vapor phase and the liquid water phase in the steam.
4. Method as in claim 3 wherein the narrow linewidth laser is a narrow linewidth single mode tunable diode laser.
5. Method as in claim 4 wherein the narrow linewidth single mode tunable diode laser is an external cavity tunable diode laser.
6. Method as in claim 3 wherein the narrow linewidth single mode tunable diode laser has a tuning range wavelength of 1366 to 1440 nm.
7. Method as in claim 3 wherein the laser beam has a linewidth of less than or equal to 0.0075 nm.
8. Method as in claim 3 wherein the laser beam has a linewidth of less than or equal to 0.005 nm.
9. Method as in claim 3 wherein the laser beam has a linewidth of less than or equal to 0.0001 nm.
10. Method as in claim 3 wherein the step of frequency-scanning comprises splitting the laser beam into a first part which passes through the steam and a second part which is diverted along a path through ambient air outside of the chamber and the method further comprises the step of measuring peak absorption amplitude of water vapor in the ambient air as the second pan of the laser beam passes through the ambient air to determine the reference peak absorption amplitude.
11. Method as in claim 3 wherein the step of frequency-scanning comprises frequency-scanning a laser beam at a wavelength of 1383.8 nm to 1384.2 nm.
12. Method as in claim 3 wherein the chamber comprises glass windows for transmission of the laser beam through the steam and the method further comprises heating the glass windows to reduce steam condensation on the windows.
13. Method as in claim 12 wherein the glass windows are high-transmission quartz glass windows.
14. Method as in claim 3 wherein the chamber is part of a steam turbine system.
15. System for determining steam quality comprising:
a chamber for containing steam, the steam having a water vapor phase and a liquid water phase;
a narrow linewidth laser operatively associated with the chamber for frequency-scanning a laser beam along a path through the steam to excite a molecular transition in the steam; and
a device for measuring peak absorption amplitude of the water vapor phase as the laser beam passes through the steam and a shift in de level of a peak absorption amplitude of the water vapor phase from a dc level of a reference peak absorption amplitude.
16. System as in claim 15 wherein the chamber comprises glass windows for transmission of the laser beam through the steam and the system further comprises a heater for heating the glass windows to reduce steam condensation on the windows.
17. System as in claim 16 wherein the glass windows are high-transmission quartz glass windows.
18. System as in claim 15 wherein the narrow linewidth laser is a narrow linewidth single mode unable diode laser.
19. System as in claim 18 wherein the narrow linewidth single mode tunable diode laser is an external cavity tunable diode laser.
20. System as in claim 18 wherein the narrow linewidth single mode tunable diode laser has a tuning range wavelength of 1366 to 1440 nm.
21. System as in claim 15 wherein the narrow linewidth laser is capable of emitting a laser beam having a linewidth of less than or equal to 0.0075 nm.
22. System as in claim 15 wherein the narrow linewidth laser is capable of emitting a laser beam having linewidth of less than or equal to 0.005 nm.
23. System as in claim 15 wherein the narrow linewidth laser is capable of emitting a laser beam having linewidth of less than or equal to 0.0001 nm.
24. System as in claim 15 further comprising a beam splitter for splitting the laser beam into a first pad which passes through the steam and a second part which is diverted along a path through ambient air outside of the chamber and a device for measuring peak absorption amplitude of water vapor in the ambient air as the second part of the laser beam passes through the ambient air.
25. System as in claim 24 wherein the device for measuring peak absorption amplitude of the water vapor phase as the laser beam passes through the steam comprises a first photodetector for measuring the intensity of the laser beam after the laser beam passes through the steam, a device for measuring peak absorption amplitude of water vapor in the ambient air as the second part of the laser beam passes through the ambient air for measuring the intensity of the laser beam after the laser beam passes through the ambient air, and an oscilloscope for determining the peak absorption amplitude of the water vapor phase in the steam based on the intensity of first pad of the laser beam and the peak absorption amplitude of water vapor in the second part of the laser beam.
26. System as in claim 15 wherein the narrow linewidth laser is capable of frequency-scanning a laser beam at a wavelength of 1383.8 nm to 1384.2 nm.
27. System as in claim 15 wherein the device for measuring peak absorption amplitude comprises a photodetector for measuring the intensity of the laser beam after the laser beam passes through the steam and an oscilloscope for determining the peak absorption amplitude of the water vapor phase based on the intensity of the laser beam.
28. System as in claim 15 wherein the narrow linewidth laser is coupled with optic fibers for laser beam transmission and conditioning.
29. A steam turbine comprising the steam quality measurement system of claim 15.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. An image processor, comprising:
an image pickup part configured to pick up a pickup image of a certain area;
an irradiator configured to irradiate at least a part of the certain area for the pickup image picked up by the image pickup part;
an extractor configured to extract, as an irradiation image, a light irradiated from the irradiator, the irradiation image being extracted from the pickup image picked up by the image pickup part;
an image generating part configured to generate an irradiation removed image which is obtained by removing the irradiation image from the pickup image;
an object recognizer configured to recognize an object in the certain area, based on the irradiation removed image generated by the image generating part;
a distance sensor configured to sense a distance to the object recognized by the object recognizer; and
an administrative processor configured to administratively control each of the image pickup part, the irradiator, the extractor, the image generating part, the object recognizer, and the distance sensor, the administrative processor including:
a frequency analyzer configured to analyze a frequency component of a signal of an original image which is the pickup image including an external light and obtained by the image pickup part, and
a controller configured to:
control the irradiator such that the irradiator is set to have an irradiation period different from a period of the frequency component of the external light obtained by the frequency analyzer, and
control the extractor to be in conformity with the irradiation period of the irradiator.
2. The image processor according to claim 1, wherein the extractor is a variable band pass filter.
3. The image processor according to claim 2, wherein the frequency analyzer is configured to set the variable band pass filter to conform to the irradiation period of the irradiator.
4. The image processor according to claim 1, wherein the extractor includes a synchronous detector configured to extract an irradiation pattern of the irradiation image, by allowing a signal synchronous with the irradiation period of the irradiator to be inputted from the controller to the synchronous detector.
5. An image processor, comprising:
an image pickup part configured to pick up a pickup image of a certain area;
an irradiator configured to irradiate at least a part of the certain area for the pickup image picked up by the image pickup part;
an extractor configured to extract, as an irradiation image, a light irradiated from the irradiator, the irradiation image being extracted from the pickup image picked up by the image pickup part;
an image generating part configured to generate an irradiation removed image which is obtained by removing the irradiation image from the pickup image;
an object recognizer configured to recognize an object in the certain area, based on the irradiation removed image generated by the image generating part;
a distance sensor configured to sense a distance to the object recognized by the object recognizer; and
a luminance determiner configured to determine a per-pixel luminance of a signal of the pickup image which is an original image,
wherein the image generating part implements a difference operation between the pickup image and the irradiation image based on a determination result of the luminance determiner, wherein the image generating part forbids the difference operation of a part of an image signal which has a determination result of less than or equal to a noise level.
6. An image processor, comprising:
an image pickup part configured to pick up a pickup image of a certain area
an irradiator configured to irradiate at least a part of the certain area for the pickup image picked up by the image pickup part;
an extractor configured to extract, as an irradiation image, a light irradiated from the irradiator, the irradiation image being extracted from the pickup image picked up by the image pickup part;
an image generating part configured to generate an irradiation removed image which is obtained by removing the irradiation image from the pickup image;
an object recognizer configured to recognize an object in the certain area, based on the irradiation removed image generated by the image generating part;
a distance sensor configured to sense a distance to the object recognized by the object recognizer,
an image moving amount calculator configured to make a time-series calculation of a moving amount of an image on a screen based on:
the irradiation image extracted by the extractor from a pickup image picked up previously, and
the irradiation image extracted by the extractor from a pickup image picked up currently; and
a moving amount corrector configured to correct the following, based on the moving amount obtained by the image moving amount calculator:
a position of the irradiation image on the screen and a size of the irradiation image, the irradiation image being included in the pickup image obtained at a next time,
wherein the image processor is configured to remove, from the current pickup image, the irradiation image included in the next pickup image.
7. An image processing method, comprising:
picking up a pickup image of a certain area;
irradiating at least a part of the certain area for the pickup image picked up by the picking up operation;
extracting, as an irradiation image, a light irradiated from the irradiating operation, the irradiation image being extracted from the pickup image picked up by the picking up operation;
generating an irradiation removed image which is obtained by removing the irradiation image from the pickup image;
recognizing an object in the certain area, based on the irradiation removed image generated by the generating operation;
sensing a distance to the object recognized by the recognizing operation;
making a time-series calculation of a moving amount of an image on a screen based on:
the irradiation image extracted by the extracting operation from the pickup image picked up previously; and
the irradiation image extracted by the extracting operation from the pickup image picked up currently; and
correcting the following, based on the moving amount obtained by the image moving amount calculating operation:
a position of the irradiation image on the screen and a size of the irradiation image, the irradiation image being included in the pickup image obtained at a next time,
wherein the image processing method removes, from the current pickup image, the irradiation image included in the next pickup image.
8. An image processor, comprising:
means for picking up a pickup image of a certain area;
means for irradiating at least a part of the certain area for the pickup image picked up by the means for picking up;
means for extracting, as an irradiation image, a light irradiated from the means for irradiating, the irradiation image being extracted from the pickup image picked up by the means for picking up;
means for generating an irradiation removed image which is obtained by removing the irradiation image from the pickup image;
means for recognizing an object in the certain area, based on the irradiation removed image generated by the means for generating; and
means for sensing a distance to the object recognized by the means for recognizing; and
means for making a time-series calculation of a moving amount of an image on a screen based on:
the irradiation image extracted by the means for extracting from the pickup image picked up previously; and
the irradiation image extracted by the means for extracting from the pickup image picked up currently; and
means for correcting the following, based on the moving amount obtained by the means for making a time-series calculation of a moving amount:
a position of the irradiation image on the screen and a size of the irradiation image, the irradiation image being included in the pickup image obtained at a next time,
wherein the image processor removes, from the current pickup image, the irradiation image included in the next pickup image.