CN115950549A - Single-camera double-color PLIF measuring device and measuring method - Google Patents

Abstract

The invention discloses a single-camera double-color PLIF measuring device and a measuring method, wherein an imaging lens, a light splitting and filtering module, a first reflection adjusting module, a second reflection adjusting module and an image combining module are integrated to form an integral optical device, and a first laser and a single camera are matched to form the single-camera double-color PLIF measuring device, the device can be used for testing to obtain a fluorescent signal-temperature relation curve in a working medium to be measured, so that the temperature distribution of a measuring position is reversely deduced according to the fluorescent signal obtained by the camera. The device reduces the difficulty and complexity of optical adjustment, thereby enabling the adjustment and use of the optical measurement part to be more convenient; after the device is adjusted, the deviation between the two images presented by the camera is extremely small, and a special algorithm is not needed for correcting the matched two images; the two-color laser induced fluorescence measuring device has higher integration level and wider usable optical magnification range compared with products provided by current commercial measuring manufacturers.

Description

Single-camera double-color PLIF measuring device and measuring method

Technical Field

The invention relates to the technical field of measurement of fluid temperature fields, in particular to a single-camera double-color PLIF measurement device and a measurement method.

Background

In the thermal fluid experiment, the temperature field of the fluid can be measured without disturbance by means of a laser-induced fluorescence method (laser-excited fluorescence, and the fluorescence intensity has a single corresponding relation with the temperature). The measurement method generally uses a single fluorescent substance as a temperature measuring substance to indirectly measure the temperature field of the fluid, the temperature sensitivity of the temperature measurement method is limited, and many other factors (such as fluorescent substance concentration, laser intensity spatial distribution, spatial angle, laser intensity time stability and the like) influence the accuracy of temperature measurement. In order to improve the laser-induced fluorescence temperature measurement method and improve the sensitivity and the anti-interference performance of the method, a two-color laser-induced fluorescence method can be selected, namely two fluorescent dyes are used, the laser is adopted to respectively excite the fluorescence of the two fluorescent dyes, the ratio processing is carried out by utilizing the relationship between the fluorescence intensity and the temperature of different fluorescent agents or other processing modes are adopted to obtain a new fluorescence signal-temperature relationship, so that the sensitivity of temperature measurement is improved, the dependence on other factors is reduced, and the anti-interference performance of the test method is improved.

However, the specific implementation of the two-color laser inducing method requires various optical components such as laser, optical filter, camera, and lens, and the two-color laser inducing method is mostly implemented by dispersed devices in current experimental practice, and the specific experimental device requires at least two cameras and matched lenses, and needs an additional synchronous control device to implement control management, so that the whole device operates. Therefore, the existing device needs multiple sets of camera lenses, the optical components are scattered, complicated field calibration needs to be performed, and the applicability of the experimental calibration relation needs to be maintained in the implementation process, so that the complexity of the measurement method is greatly improved, and the experiment development needs to consume more time cost and material cost.

Disclosure of Invention

The present invention is directed to solving, at least to some extent, one of the technical problems in the related art. Therefore, the invention aims to provide a single-camera double-color PLIF measuring device and a measuring method. The invention integrates the optical measurement part into a whole, thus reducing the difficulty and complexity of optical adjustment and leading the adjustment and use of the optical measurement part to be more convenient; the light splitting and image splitting adjusting module is formed by combining the light splitting and filtering module, the first reflection adjusting module, the second reflection adjusting module and the image combining module, and double images of different spectral bands required by the double-color PLIF can be formed only by combining one set of camera and an imaging lens; after the device is adjusted, the deviation between the double images presented by the camera is extremely small, and a special algorithm is not needed to correct and match the double images; the two-color laser induced fluorescence measuring device has higher integration level and wider usable optical magnification range compared with products provided by current commercial measuring manufacturers.

In a first aspect of the invention, a single-camera two-color PLIF measurement apparatus is presented. According to an embodiment of the present invention, the single-camera two-color PLIF measurement apparatus includes:

the first laser is used for exciting two fluorescent agents contained in the first working medium to be detected to generate two kinds of fluorescence;

the two types of fluorescence excited by the first laser enter the imaging lens for imaging;

the light from the imaging lens is dispersed into first light and second light after passing through the light splitting and filtering module, the wavelength of the first light is greater than that of the second light, the first light passes through the first reflection and adjustment module and then reaches the image combining module, and the second light passes through the second reflection and adjustment module and then reaches the image combining module;

a camera for respectively imaging the first light and the second light passing through the image combining module.

According to the single-camera two-color PLIF measuring device provided by the embodiment of the invention, firstly, the optical measuring part is integrated into a whole, so that the difficulty and complexity of optical adjustment are reduced, and the adjustment and use of the optical measuring part are more convenient; secondly, a light splitting and image splitting adjusting module is formed by combining the light splitting and filtering module, the first reflection adjusting module, the second reflection adjusting module and the image combining module, and double images of different spectral bands required by the double-color PLIF can be formed only by combining one set of camera and an imaging lens; thirdly, after the device is adjusted, the deviation between the double images presented by the camera is extremely small, and a special algorithm is not needed for correcting and matching the double images; fourthly, the two-color laser induced fluorescence measuring device has higher integration level and wider usable optical magnification range compared with products provided by current commercial measuring manufacturers.

In addition, the single-camera two-color PLIF measurement apparatus according to the above embodiment of the present invention may further have the following additional technical features:

in some embodiments of the invention, the first laser comprises a first sub-laser and a second sub-laser.

In some embodiments of the invention, the apparatus further comprises: and the first laser beam combining mirror module is used for combining the laser emitted by the first sub laser and the laser emitted by the second sub laser.

In some embodiments of the invention, the apparatus further comprises: the first light splitting module is arranged on a light path between the first laser beam combining mirror module and the first to-be-detected working medium, and the first laser energy meter is arranged on a laser path line split by the first light splitting module.

In some embodiments of the invention, the apparatus further comprises: and the first optical component is arranged on an optical path between the first light splitting module and the first to-be-detected working medium.

In some embodiments of the invention, further comprising: the aperture controller is arranged at one end, close to the first working medium to be detected, of the imaging lens; and/or, further comprising: and the adjustable slit is arranged at one end of the imaging lens, which is close to the light splitting and image splitting adjusting module.

In some embodiments of the invention, further comprising: the first adapter is connected between the adjustable slit and the light splitting and image splitting adjusting module; and/or, further comprising: a second adapter connected between the spectral split adjustment module and the camera.

In some embodiments of the present invention, a long-wave pass short-wave reflection dichroic mirror is disposed in the spectral filtering module; and/or a first reflector is arranged in the first reflection adjusting module; and/or a second reflecting mirror is arranged in the second reflection adjusting module; and/or a long-wave anti-short wave pass dichroic mirror is arranged in the image combining module; and/or a photosensitive member is provided in the camera.

In some embodiments of the present invention, the spectral imaging adjustment module further includes a long-wave pass filter and a first narrow-band light trap, where the long-wave pass filter and the first narrow-band light trap are respectively disposed between the long-wave pass short-wave reflection dichroic mirror and the first reflector; and/or the light splitting and image splitting adjusting module further comprises a band-pass wave filter and a second narrow-band light trapping piece, wherein the band-pass wave filter and the second narrow-band light trapping piece are respectively arranged between the long-wave-pass short-wave reflection dichroic mirror and the second reflecting mirror.

In some embodiments of the present invention, the first substance to be tested comprises a first fluorescent agent and a second fluorescent agent, the fluorescence intensity of the first fluorescent agent is positively correlated with temperature, and the fluorescence intensity of the second fluorescent agent is negatively correlated with temperature; or the fluorescence intensity of the first fluorescent agent is positively correlated with the temperature, and the fluorescence intensity of the second fluorescent agent is zero correlated with the temperature; or the fluorescence intensity of the first fluorescent agent is inversely related to the temperature, and the fluorescence intensity of the second fluorescent agent is zero-related to the temperature.

In some embodiments of the invention, further comprising: the principle verifying device is used for determining the light intensity of the first laser, the types and the concentrations of two fluorescent agents in the first working medium to be tested, and comprises: the second laser comprises a third sub laser and a fourth sub laser, the second laser beam combining mirror module is used for combining laser emitted by the third sub laser and laser emitted by the fourth sub laser, the second light splitting module, the second sheet optical component and the second working medium to be detected are sequentially arranged on a light path of the combined laser, the second laser energy meter is arranged on a laser light path line divided by the second light splitting module, the second working medium to be detected generates two kinds of fluorescence under the excitation of the laser emitted by the second sheet optical component, the fluorescence receiving module comprises a focusing lens and a third narrow-band light trapping sheet, the fluorescence generated by the second working medium to be detected sequentially passes through the focusing lens and the third narrow-band light trapping sheet, and the fluorescence receiving module and the spectrum analyzer are connected through optical fibers.

In a second aspect of the invention, a method of measuring the temperature field of a fluid using the single camera dual color PLIF measurement apparatus described in the above embodiments is provided. According to an embodiment of the invention, the method comprises:

(1) Determining the light intensity of the first laser, the types and the concentrations of two fluorescent agents in the first working medium to be detected;

(2) Starting a first laser to excite the first to-be-detected working medium to generate two kinds of fluorescence;

(3) The two kinds of fluorescence pass through the imaging lens, light rays coming out of the imaging lens are dispersed into first light rays and second light rays after passing through the light splitting and filtering module, the first light rays pass through the first reflection adjusting module and then reach the image combining module, the second light rays pass through the second reflection adjusting module and then reach the image combining module, and the first light rays and the second light rays passing through the image combining module are respectively imaged by the camera so as to obtain fluorescence signals;

(4) Changing the temperature of the first working medium to be detected, and measuring corresponding fluorescent signals of the first working medium to be detected at different specific temperatures according to the method in the step (3) so as to obtain a fluorescent signal-temperature relation curve of the first working medium to be detected;

(5) And reversely deducing the temperature distribution of the measuring position according to the fluorescence signal obtained by the camera based on the fluorescence signal-temperature relation curve.

According to the method for measuring the temperature field of the fluid in the embodiment of the invention, the single-camera double-color PLIF measuring device integrating the optical measuring part into a whole is adopted, so that the difficulty and complexity of optical adjustment are reduced, and the adjustment and use of the optical measuring part are more convenient; the method adopts a light splitting and image splitting adjusting module formed by combining a light splitting and filtering module, a first reflection adjusting module, a second reflection adjusting module and an image combining module, and can form double images of different spectral bands required by a double-color PLIF (planar image filter) by only using a set of camera and imaging lens combination; after the method is used for adjusting, the deviation between the double images presented by the camera is extremely small, and a special algorithm is not needed for correcting and matching the double images; the two-color laser induced fluorescence measuring device adopted by the method has higher integration level, and the usable optical magnification range is wider than that of products provided by current commercial measuring manufacturers.

In addition, the method according to the above embodiment of the present invention may also have the following additional technical features:

in some embodiments of the invention, step (1) comprises the steps of: starting a second laser to excite a second working medium to be detected containing any two fluorescers to generate two fluorescences; and enabling the two types of fluorescence to sequentially pass through the focusing lens and the third narrow-band light trapping sheet to enter a spectrum analyzer, and obtaining a change curve of the fluorescence intensity-laser irradiation relation of the two fluorescent agents according to the change of the fluorescence intensity along with time so as to select the light intensity of the second laser, the type and the concentration of the fluorescent agent.

Additional aspects and advantages of the invention will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the invention.

Drawings

The above and/or additional aspects and advantages of the present invention will become apparent and readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which:

FIG. 1 is a schematic diagram of a single camera dual color PLIF measurement apparatus according to an embodiment of the present invention;

FIG. 2 is a schematic diagram of a principle verification device according to an embodiment of the present invention;

FIG. 3 is a flow chart of a method for measuring a fluid temperature field using a single camera bi-color PLIF measurement apparatus according to an embodiment of the present invention.

The attached drawings are marked as follows:

100-a first working medium to be tested, 200-an aperture controller, 300-an imaging lens, 400-an adjustable slit, 500-a first adapter, 600-a light splitting and image splitting adjusting module, 610-a light splitting and filtering module, 611-a long-wave pass short-wave reflection and light splitting mirror, 620-a first reflection and adjusting module, 621-a first reflector, 630-a second reflection and adjusting module, 631-a second reflector, 640-an image combining module, 641-a long-wave reverse short-wave pass light splitting mirror, 650-a long-wave pass filter, 660-a band-pass filter, 700-a second adapter, 800-a camera, 810-a photosensitive member, 910-a first sub-laser, 920-a second sub-laser, 930-a first laser beam combining mirror module, 940-a first light splitting module, 950-a first laser energy trap meter, 960-a first sheet optical assembly, 1000-principle verification device, 1100-a third sub-laser, 1200-a fourth sub-laser, 1300-a second laser beam combining mirror module, 1400-a second light splitting mirror module, 1600-a second laser energy trap optical assembly, 1600-a narrow band focusing optical analyzer, 1802-a second light band receiving narrow-band optical spectrum analyzer, and a narrow band focusing optical spectrum analyzer.

Detailed Description

Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the accompanying drawings are illustrative and intended to explain the present invention and should not be construed as limiting the present invention.

In the description of the present invention, it is to be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "axial", "radial", "circumferential", and the like, indicate orientations and positional relationships based on the orientations and positional relationships shown in the drawings, and are used merely for convenience in describing the present invention and for simplicity in description, and do not indicate or imply that the elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore, are not to be construed as limiting the present invention.

Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or to implicitly indicate the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of the feature. In the description of the present invention, "a plurality" means at least two, e.g., two, three, etc., unless specifically limited otherwise.

In the present invention, unless otherwise expressly specified or limited, the terms "mounted," "connected," "secured," and the like are to be construed broadly and can, for example, be fixedly connected, detachably connected, or integrally formed; can be mechanically or electrically connected; they may be directly connected or indirectly connected through intervening media, or they may be connected internally or in any other suitable relationship, unless expressly stated otherwise. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.

In the present invention, unless otherwise expressly stated or limited, the first feature "on" or "under" the second feature may be directly contacting the first and second features or indirectly contacting the first and second features through an intermediate. Also, a first feature "on," "over," and "above" a second feature may be directly or diagonally above the second feature, or may simply indicate that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature may be directly under or obliquely under the first feature, or may simply mean that the first feature is at a lesser elevation than the second feature.

In one aspect of the present invention, the present invention provides a single-camera two-color PLIF measurement apparatus, referring to fig. 1, the single-camera two-color PLIF measurement apparatus comprising: a first laser; an imaging lens 300; the spectral image-splitting adjusting module 600, the spectral image-splitting adjusting module 600 includes a spectral filtering module 610, a first reflection adjusting module 620, a second reflection adjusting module 630 and an image combining module 640; and a camera 800. The following describes the single-camera two-color PLIF measurement device according to the present invention in detail with reference to the accompanying drawings.

In an embodiment of the present invention, the first laser is used to excite two fluorescent agents contained in the first substance to be detected 100 to generate two fluorescence lights. Further, referring to fig. 1, the first laser includes a first sub-laser 910 and a second sub-laser 920, and the first sub-laser 910 and the second sub-laser 920 respectively emit two laser beams with different intensities, which are respectively used for exciting two fluorescent agents to generate two fluorescence. It should be noted that different fluorescent agents need to be excited by laser with different intensities, for example, a rhodamine B fluorescent dye corresponds to 532nm laser, and fluorescein sodium corresponds to 477nm laser.

In an embodiment of the invention, with reference to fig. 1, the apparatus further comprises: the first laser beam combiner module 930, the first laser beam combiner module 930 is configured to combine the laser light emitted by the first sub-laser 910 with the laser light emitted by the second sub-laser 920. Further, with reference to fig. 1, the apparatus further comprises: the first light splitting module 940 is arranged on an optical path between the first laser beam combining mirror module 930 and the first workpiece 100 to be measured, the first light splitting module 940 is used for splitting a small proportion of laser light, the small proportion of laser light is projected to the first laser energy meter 950, and the large proportion of laser light is reflected to the first optical assembly 960. The first laser energy meter 950 is disposed on the laser path split by the first light splitting module 940, and is configured to detect power stability of the combined laser. Further, with reference to fig. 1, the apparatus further comprises: a first optical component 960 (e.g., a lens), wherein the first optical component 960 is disposed on an optical path between the first beam splitter 940 and the first to-be-measured medium 100, and is configured to combine the beams to form a sheet of light.

In an embodiment of the present invention, the first substance to be tested 100 may be disposed in a cuvette cell.

In the embodiment of the present invention, referring to fig. 1, an imaging lens 300, the imaging lens 300 is used for imaging an imaging object (i.e. a working medium containing a fluorescent agent), and a commercial lens or an ad hoc lens may be adopted.

Further, with reference to fig. 1, the apparatus further comprises: and the aperture controller 200, the aperture controller 200 being disposed at an end of the imaging lens 300 close to the first to-be-detected workpiece 100, is used for adjusting the light-entering amount of the imaging lens 300, and the imaging depth of field can be adjusted by adjusting the aperture controller 200.

Further, with reference to fig. 1, the apparatus further comprises: the adjustable slit 400 is disposed at one end of the imaging lens 300 close to the spectral image splitting adjustment module 600, and is used for adjusting an imaging range.

In an embodiment of the present invention, referring to fig. 1, the light splitting and image splitting adjustment module 600 includes a light splitting and filtering module 610, a first reflection adjustment module 620, a second reflection adjustment module 630 and an image combining module 640, where light rays coming out from the imaging lens 300 are dispersed into first light rays and second light rays after passing through the light splitting and filtering module 610, a wavelength of the first light rays is greater than a wavelength of the second light rays, the first light rays pass through the first reflection adjustment module 620 and then reach the image combining module 640, and the second light rays pass through the second reflection adjustment module 630 and then reach the image combining module 640. Alternatively, 4 small modules included in the spectral splitting adjustment module 600 are integrated.

Further, referring to fig. 1, a long-wavelength-pass short-wavelength reflection dichroic mirror 611 is disposed in the spectral filtering module 610, which is required to ensure that the long-wavelength fluorescence (i.e., the first light) can be transmitted, and the short-wavelength fluorescence (i.e., the second light) is reflected or absorbed. Referring to fig. 1, a first reflector 621 is disposed in the first reflection adjustment module 620 for reflecting the first light to the image combining module 640. Referring to fig. 1, a second reflecting mirror 631 is disposed in the second reflection adjustment module 630 for reflecting the second light to the image combining module 640. Referring to fig. 1, the image combining module 640 is provided with a long-wave anti-short-wave pass dichroic mirror 641, which is required to ensure that the long-wave fluorescence (i.e., the first light) is reflected or absorbed, and the short-wave fluorescence (i.e., the second light) is transmitted, so as to achieve the purpose of combining the first light and the second light. In fig. 1, an arrow in an imaging object is taken as an example for explanation, and during imaging, the arrow passes through the imaging lens 300, and light enters the spectral imaging module, wherein light (i.e. first light) above a specific spectral threshold forms one image, and light (i.e. second light) below the specific spectral threshold forms another image.

Optionally, the long-wave pass short-wave reflection dichroic mirror 611 is fixed in the spectral filtering module 610 through a 45-degree lens holder. Optionally, the long-wave anti-short wave pass dichroic mirror 641 is fixed in the image combining module 640 through a 45-degree lens support. Optionally, the first reflector 621 is disposed in the first reflection adjustment module 620 through an angle-adjustable lens holder; optionally, the second reflecting mirror 631 is disposed in the second reflection adjusting module 630 through an angle-adjustable mirror holder, so that the imaging distance of the first light and the second light (i.e., the distance imaged by two arrows in the camera 800 of fig. 1) can be adjusted.

Further, referring to fig. 1, the spectral image splitting adjustment module 600 further includes a long-wave pass filter 650 and a first narrow-band light trap (not shown in the figure), and the long-wave pass filter 650 and the first narrow-band light trap are respectively disposed between the long-wave pass short-wave reflecting dichroic mirror 611 and the first reflecting mirror 621. The long-wave pass filter 650 is used for ensuring that the fluorescence of long wave passes through and other stray light is filtered; the first narrow-band light trap functions to filter out laser peaks generated by the first laser in the fluorescent doping.

Further, referring to fig. 1, the spectral image splitting adjustment module 600 further includes a band-pass filter 660 and a second narrow-band light trap (not shown in the figure), and the band-pass filter 660 and the second narrow-band light trap are respectively disposed between the long-pass short-wave reflecting dichroic mirror 611 and the second reflecting mirror 631. The band-pass filter 660 has the function of ensuring that short-wave fluorescence passes through, other stray light is filtered out, and the second narrow-band light trap has the function of filtering out a laser peak value generated by the first laser in fluorescence doping.

The first narrow band light trapping sheet and the second narrow band light trapping sheet are selected with the first laser wavelength used as the center wavelength, and the bandwidth is preferably 10nm to 25nm (e.g., 10nm or 25 nm), and is as low as possible to filter out reflected, scattered laser light and stray light and retain as much center wavelength fluorescence information as possible.

Further, with reference to fig. 1, the apparatus further comprises: the first adapter 500, the first adapter 500 is connected between the adjustable slit 400 and the split image adjusting module 600, for connecting the imaging lens 300 and the split image adjusting module 600 as a whole. Further, with reference to fig. 1, the apparatus further comprises: the second adapter 700, the second adapter 700 is connected between the split image adjusting module 600 and the camera 800, for connecting the split image adjusting module 600 and the camera 800 into a whole, thereby integrating the optical measurement part into a whole, reducing difficulty and complexity of optical adjustment, and facilitating adjustment and use of the optical measurement part. Meanwhile, by adjusting the imaging lens 300, the first adapter 500, or the second adapter 700, the imaging optical magnification can be adjusted.

Further, referring to fig. 1, the camera 800 is configured to image the first light and the second light respectively via the image combining module 640. Further, a photosensitive member 810 is provided in the camera 800.

Furthermore, the working medium of the two fluorescent agents comprises a first fluorescent agent and a second fluorescent agent, the fluorescence intensity of the first fluorescent agent is positively correlated with the temperature, and the fluorescence intensity of the second fluorescent agent is negatively correlated with the temperature; or the fluorescence intensity of the first fluorescent agent is positively correlated with the temperature, and the fluorescence intensity of the second fluorescent agent is zero correlated with the temperature; or the fluorescence intensity of the first fluorescent agent is inversely related to the temperature, and the fluorescence intensity of the second fluorescent agent is zero-related to the temperature. By adopting the two fluorescent agents to carry out ratio processing or adopting other processing modes, a new fluorescent signal-temperature relation is obtained, so that the influence of the factors such as fluorescent substance concentration, laser intensity spatial distribution, spatial angle, laser intensity time stability and the like on the temperature measurement accuracy is eliminated, the sensitivity of temperature measurement is improved (the sensitivity is improved by 2-5 times), the dependence on other factors is reduced, and the anti-interference capability of the measurement method is improved. The invention determines the types of two fluorescers by a principle verification device.

As mentioned above, the fluorescent substance concentration, the fluorescent substance type and the laser intensity spatial distribution all affect the fluorescent temperature distribution, so when measuring the temperature field of the fluid, it is first necessary to select a proper fluorescent substance concentration, fluorescent substance type and laser intensity in the first working medium 100 to be measured. Thus, with reference to fig. 2, the apparatus further comprises: principle verifying attachment 1000, principle verifying attachment 1000 is used for confirming the light intensity of the first laser, the kind and concentration of two fluorescent agents in the first work substance 100 to be measured, and principle verifying attachment 1000 includes: the system comprises a second laser, a second laser beam combiner module 1300, a second light splitting module 1400, a second laser energy meter 1500, a second optical assembly 1600, a second working medium to be detected 1700, a fluorescence receiving module 1800 and a spectrum analyzer 1900. The second laser comprises a third sub laser 1100 and a fourth sub laser 1200, and the third sub laser 1100 and the fourth sub laser 1200 respectively emit two lasers with different intensities, and the two lasers are respectively used for exciting two fluorescent agents to generate two fluorescent lights. The second laser beam combining mirror module 1300 is configured to combine the laser light emitted by the third sub-laser 1100 and the laser light emitted by the fourth sub-laser 1200. The second light splitting module 1400, the second sheet of optical assembly 1600 and the second working medium to be detected 1700 are sequentially arranged on the light path of the combined laser, the second light splitting module 1400 is used for splitting a small proportion of laser, and the second laser energy meter 1500 is arranged on a laser route split by the second light splitting module 1400 and used for detecting the power stability of the laser after combination. The second light sheet assembly 1600 is used for forming a light sheet by the combined laser. The second working medium 1700 to be tested generates two kinds of fluorescence under the excitation of the laser emitted from the second optical assembly 1600, the fluorescence receiving module 1800 includes a focusing lens 1802 and a third narrow-band light trapping sheet 1801, the focusing lens 1802 is used for focusing, and the third narrow-band light trapping sheet 1801 is used for filtering out the laser peak value generated by the second laser in the fluorescence doping. Fluorescence generated by the second working medium to be detected 1700 sequentially passes through the focusing lens 1802 and the third narrow-band light trapping sheet 1801, and the fluorescence receiving module 1800 and the spectrum analyzer 1900 are connected through optical fibers. Specifically, the appropriate laser intensity, fluorescent dye type, concentration, etc. are selected according to the variation of the integral values of the long-wave fluorescence and short-wave fluorescence spectra received by the spectrum analyzer 1900 with the laser intensity, fluorescent dye concentration, and temperature. Further, irradiating a fluid sample containing a fluorescent coloring agent by using laser for a long time, observing the change of the fluorescence intensity along with time, and qualitatively providing a change curve of the fluorescence intensity-laser irradiation relation in the quenching process of the fluorescent substance according to the change of the fluorescence intensity along with time, so as to determine the appropriate application range of the laser intensity and the concentration; finally obtaining the proper experimental configuration.

And finally, selecting a first fluorescent agent with the fluorescence intensity positively correlated to the temperature and a second fluorescent agent with the fluorescence intensity negatively correlated to the temperature, or selecting the first fluorescent agent with the fluorescence intensity positively correlated to the temperature and the second fluorescent agent with the fluorescence intensity zero correlated to the temperature, or selecting the first fluorescent agent with the fluorescence intensity negatively correlated to the temperature and the second fluorescent agent with the fluorescence intensity zero correlated to the temperature.

In the prior art, to implement a two-color laser induced method, at least two cameras and associated lenses are required, and an additional synchronous control device is required to implement control management, so that the whole device operates. Therefore, the optical components of the conventional device are scattered, complicated field calibration is required, the applicability of an experimental calibration relation needs to be maintained in the implementation process, the complexity of the measurement method is greatly improved, and the experiment development needs to consume more time cost and material cost. In order to solve the above problems, the present invention integrates the imaging lens, the spectral filtering module, the first reflection adjustment module, the second reflection adjustment module, and the image combining module to form an integrated optical device, and combines with the first laser and the single camera to form a two-color laser induced fluorescence imaging device, wherein the two-color laser induced fluorescence imaging device has at least one of the following advantages:

firstly, the optical measurement part is integrated into a whole, so that the difficulty and complexity of optical adjustment are reduced, and the adjustment and use of the optical measurement part are more convenient;

secondly, a light splitting and image splitting adjusting module is formed by combining the light splitting and filtering module, the first reflection adjusting module, the second reflection adjusting module and the image combining module, and double images of different spectral bands required by the double-color PLIF can be formed only by combining one set of camera and an imaging lens;

thirdly, after the device is adjusted, the deviation between the double images presented by the camera is extremely small, and a special algorithm is not needed for correcting and matching the double images;

fourthly, the two-color laser induced fluorescence measuring device has higher integration level and wider range of usable optical magnification compared with products provided by current commercial measuring manufacturers. Specifically, the light-splitting image-splitting adjusting module is arranged between the imaging lens and the camera, the image distance is increased, the optical magnification can be larger, the size of the light-splitting image-splitting adjusting module can be very compact, and the image distance and the object distance can be controlled by selecting a proper lens, so that the optical magnification is reduced. If the light-splitting and image-splitting adjusting module is arranged between the imaging lens and the object, the effect of increasing the image distance cannot be achieved.

In a second aspect of the invention, the invention provides a method for measuring the temperature field of a fluid using the single-camera two-color PLIF measurement device described above in the embodiments above. According to an embodiment of the invention, with reference to fig. 3, the method comprises:

s100: determining the light intensity of the first laser, the types and concentrations of two fluorescent agents in the first working medium to be detected

In this step, the principle verification device is used to determine the light intensity of the first laser, the types and concentrations of the two fluorescent agents in the first workpiece 100 to be tested, and the method specifically comprises the following steps:

starting a second laser to excite a second working medium to be detected containing any two fluorescers to generate two fluorescences;

and the two kinds of fluorescence sequentially pass through the focusing lens and the third narrow-band light trapping sheet to enter the spectrum analyzer, and the change curve of the fluorescence intensity-laser irradiation relation of the two fluorescent agents is obtained according to the change of the fluorescence intensity along with time, so that the light intensity of the second laser, the types of the fluorescent agents and the concentration of the fluorescent agents are selected appropriately.

Specifically, a third sub laser and a fourth sub laser are respectively started, the third sub laser and the fourth sub laser respectively emit two kinds of laser with different intensities, a second laser beam combining mirror module combines the laser emitted by the third sub laser and the laser emitted by the fourth sub laser, the second light splitting module divides a small proportion of laser, a second laser energy meter detects the power stability of the combined laser, the second light assembly combines the combined laser to form a sheet of light, a working medium containing two fluorescent agents generates two kinds of fluorescence under the excitation of the laser emitted by the second light assembly, and the two kinds of fluorescence sequentially pass through a focusing lens and a third narrow-band light trapping sheet and enter a spectrum analyzer. And selecting proper laser intensity, fluorescence stain type, concentration and the like according to the changes of the spectrum integral values of the long-wave fluorescence and the short-wave fluorescence received by the spectrum analyzer along with the laser intensity, the fluorescence stain concentration and the temperature. Further, irradiating a fluid sample containing a fluorescent coloring agent by using laser for a long time, observing the change of the fluorescence intensity along with time, and qualitatively providing a change curve of the fluorescence intensity-laser irradiation relation in the quenching process of the fluorescent substance according to the change of the fluorescence intensity along with time, so as to determine the appropriate application range of the laser intensity and the concentration; finally obtaining the proper experimental configuration.

And finally, selecting a first fluorescent agent with the fluorescence intensity positively correlated to the temperature and a second fluorescent agent with the fluorescence intensity negatively correlated to the temperature, or selecting the first fluorescent agent with the fluorescence intensity positively correlated to the temperature and the second fluorescent agent with the fluorescence intensity zero correlated to the temperature, or selecting the first fluorescent agent with the fluorescence intensity negatively correlated to the temperature and the second fluorescent agent with the fluorescence intensity zero correlated to the temperature.

S200: starting the first laser to excite the first substance to be detected to generate two kinds of fluorescence

In the step, a first sub laser and a second sub laser are started, the first sub laser and the second sub laser respectively emit two lasers with different intensities, a first laser beam combining mirror module combines the lasers emitted by the first sub laser and the lasers emitted by the second sub laser, a first light splitting module splits a small proportion of the lasers, a first laser energy meter detects the power stability of the lasers after combination, the lasers form a sheet of light after combination, and a first working medium to be detected generates two kinds of fluorescence under the excitation of the lasers emitted by the first sheet of light module. It should be noted that the two fluorescent agents contained in the working medium in this step are known fluorescent agents, and the concentrations of the fluorescent agents in the working medium are also known and determined by using the principle verification device in step S100. Meanwhile, the intensities of the first sub-laser and the second sub-laser in this step are also determined in step S100 by using the principle verification device.

As a specific example, 477nm and 532nm laser devices are selected, the two laser devices are combined, and after the power stability of the laser light is detected through light splitting, a sheet of light is formed through a sheet of light assembly. The fluorescent dye substance is selected from rhodamine B fluorescent dye and fluorescein sodium dye. The fluorescence wavelength of the rhodamine B fluorescence staining agent is 532nm, the generated fluorescence peak value is about 550-560 nm, and the relationship between the fluorescence intensity and the temperature is negative correlation; the fluorescence wavelength of the fluorescein sodium staining agent is 477nm, the fluorescence peak value is about 500-520 nm, and the fluorescence intensity is in positive correlation with the temperature.

S300: two kinds of fluorescence pass through imaging lens, and the light that comes out from imaging lens disperses into first light and second light behind beam split filter module, and first light is to closing the image module behind first reflection adjustment module, and the second light is to closing the image module behind second reflection adjustment module, adopts the camera to close first light and second light of image module and form images respectively to obtain fluorescence signal

In the step, the two fluorescence lights pass through the imaging lens to image an imaging object (namely, a working medium containing a fluorescent agent). Light rays coming out of the imaging lens are dispersed into first light rays (namely light rays higher than a specific light splitting threshold value) and second light rays (light rays lower than the specific light splitting threshold value) through the light splitting filtering module, the first light rays and the second light rays are imaged respectively, the first light rays are reflected to the image combining module through the first reflection adjusting module, the second light rays are reflected to the image combining module through the second reflection adjusting module, and the first light rays and the second light rays passing through the image combining module are imaged respectively by a camera so as to obtain a fluorescent signal.

S400: changing the temperature of the first working medium to be measured, and measuring the corresponding fluorescent signals of the first working medium to be measured at different specific temperatures according to the method of the step S300 so as to obtain the fluorescent signal-temperature relation curve of the first working medium to be measured

In this step, the temperature of the first working medium to be detected is changed according to the set temperature (e.g., 0 ℃,10 ℃,20 ℃,30 ℃,40 ℃,50 ℃,60 ℃,70 ℃,80 ℃, 90 ℃,100 ℃, etc.), and then the fluorescence signals corresponding to the first working medium to be detected at each set temperature are measured according to the method of step S300, so as to obtain the fluorescence signal-temperature relationship curve of the first working medium to be detected.

S500: reversely deducing the temperature distribution of the measuring position according to the fluorescence signal obtained by the camera based on the fluorescence signal-temperature relation curve

In this step, since only the fluorescence intensity corresponding to the set temperature (e.g., 0 ℃ C., 10 ℃ C.) is measured in step S400, and the temperature between 0 ℃ C. And 10 ℃ C. Is not measured, the corresponding fluorescence signal in this temperature range can be determined by a linear graduation method. Therefore, the temperature distribution corresponding to the measurement position can be reversely deduced according to the fluorescence signal obtained by the camera based on the fluorescence signal-temperature relation curve.

According to the method for measuring the temperature field of the fluid in the embodiment of the invention, the single-camera double-color PLIF measuring device integrating the optical measuring part into a whole is adopted, so that the difficulty and complexity of optical adjustment are reduced, and the adjustment and use of the optical measuring part are more convenient; the method adopts a light splitting and image splitting adjusting module formed by combining a light splitting and filtering module, a first reflection adjusting module, a second reflection adjusting module and an image combining module, and can form double images of different spectral bands required by a double-color PLIF (planar image filter) by only using a set of camera and imaging lens combination; after the method is used for adjusting, the deviation between the double images presented by the camera is extremely small, and a special algorithm is not needed for correcting and matching the double images; the two-color laser induced fluorescence measuring device adopted by the method has higher integration level, and the usable optical magnification range is wider than that of products provided by current commercial measuring manufacturers.

In the description herein, references to the description of the term "one embodiment," "some embodiments," "an example," "a specific example," or "some examples," etc., mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above are not necessarily intended to refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Furthermore, various embodiments or examples and features of different embodiments or examples described in this specification can be combined and combined by one skilled in the art without contradiction.

Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention, and that variations, modifications, substitutions and alterations can be made to the above embodiments by those of ordinary skill in the art within the scope of the present invention.

Claims (10)

1. A single-camera, two-color PLIF measurement apparatus, comprising:

the first laser is used for exciting two fluorescent agents contained in the first working medium to be detected to generate two kinds of fluorescence;

the two types of fluorescence excited by the first laser enter the imaging lens for imaging;

the light from the imaging lens is dispersed into first light and second light after passing through the light splitting and filtering module, the wavelength of the first light is greater than that of the second light, the first light passes through the first reflection and adjustment module and then reaches the image combining module, and the second light passes through the second reflection and adjustment module and then reaches the image combining module;

and the camera is used for respectively imaging the first light ray and the second light ray which pass through the image combination module.

2. The single-camera, dual-color PLIF measurement device of claim 1, wherein the first laser comprises a first sub-laser and a second sub-laser;

optionally, the apparatus further comprises: the first laser beam combining mirror module is used for combining the laser emitted by the first sub laser and the laser emitted by the second sub laser;

optionally, the apparatus further comprises: the first light splitting module is arranged on an optical path between the first laser beam combining mirror module and the first to-be-detected working medium, and the first laser energy meter is arranged on a laser route split by the first light splitting module;

optionally, the apparatus further comprises: and the first optical component is arranged on an optical path between the first light splitting module and the first to-be-detected working medium.

3. The single-camera, dual-color PLIF measurement device of claim 1, further comprising: the aperture controller is arranged at one end, close to the first working medium to be detected, of the imaging lens;

and/or, further comprising: and the adjustable slit is arranged at one end of the imaging lens, which is close to the light splitting and image splitting adjusting module.

4. The single-camera, dual-color PLIF measurement device of claim 3, further comprising: the first adapter is connected between the adjustable slit and the light splitting and image splitting adjusting module;

and/or, further comprising: a second adapter connected between the spectral splitting adjustment module and the camera.

5. The single-camera two-color PLIF measurement apparatus according to any of claims 1-4, wherein a long-wave pass short-wave reflection dichroic mirror is disposed in the spectral filtering module;

and/or a first reflector is arranged in the first reflection adjusting module;

and/or a second reflecting mirror is arranged in the second reflection adjusting module;

and/or a long-wave anti-short wave pass dichroic mirror is arranged in the image combining module;

and/or a photosensitive component is arranged in the camera.

6. The single-camera bi-color PLIF measurement apparatus of claim 5 wherein said spectral split adjustment module further comprises a long pass filter and a first narrow band notch, said long pass filter and said first narrow band notch being disposed between said long pass short wave reflective dichroic mirror and said first reflector, respectively;

and/or the light splitting and image splitting adjusting module further comprises a band-pass wave filter and a second narrow-band light trapping piece, wherein the band-pass wave filter and the second narrow-band light trapping piece are respectively arranged between the long-wave-pass short-wave reflection dichroic mirror and the second reflecting mirror.

7. The single-camera, dual-color PLIF measurement device of any of claims 1-4, wherein the first test substance comprises a first phosphor having a fluorescence intensity that is positively correlated with temperature and a second phosphor having a fluorescence intensity that is negatively correlated with temperature;

or the fluorescence intensity of the first fluorescent agent is positively correlated with the temperature, and the fluorescence intensity of the second fluorescent agent is zero correlated with the temperature;

or the fluorescence intensity of the first fluorescent agent is inversely related to the temperature, and the fluorescence intensity of the second fluorescent agent is zero-related to the temperature.

8. The single-camera, dual-color PLIF measurement apparatus of any of claims 1-4, further comprising: the principle verifying device is used for determining the light intensity of the first laser, the types and the concentrations of two fluorescent agents in the first working medium to be tested, and comprises: the second laser comprises a third sub laser and a fourth sub laser, the second laser beam combining mirror module is used for combining laser emitted by the third sub laser and laser emitted by the fourth sub laser, the second light splitting module, the second sheet optical component and the second working medium to be detected are sequentially arranged on a light path of the combined laser, the second laser energy meter is arranged on a laser light path line divided by the second light splitting module, the second working medium to be detected generates two kinds of fluorescence under the excitation of the laser emitted by the second sheet optical component, the fluorescence receiving module comprises a focusing lens and a third narrow-band light trapping sheet, the fluorescence generated by the second working medium to be detected sequentially passes through the focusing lens and the third narrow-band light trapping sheet, and the fluorescence receiving module and the spectrum analyzer are connected through optical fibers.

9. A method of measuring a temperature field of a fluid using the single camera dual color PLIF measurement device of any of claims 1-8, comprising:

(1) Determining the light intensity of the first laser, the types and the concentrations of two fluorescent agents in the first working medium to be detected;

(2) Starting a first laser to excite the first to-be-detected working medium to generate two kinds of fluorescence;

(3) The two kinds of fluorescence pass through the imaging lens, light rays coming out of the imaging lens are dispersed into first light rays and second light rays after passing through the light splitting and filtering module, the first light rays pass through the first reflection adjusting module and then reach the image combining module, the second light rays pass through the second reflection adjusting module and then reach the image combining module, and the first light rays and the second light rays passing through the image combining module are respectively imaged by the camera so as to obtain fluorescence signals;

(4) Changing the temperature of the first working medium to be detected, and measuring corresponding fluorescent signals of the first working medium to be detected at different specific temperatures according to the method in the step (3) so as to obtain a fluorescent signal-temperature relation curve of the first working medium to be detected;

(5) And reversely deducing the temperature distribution of the measuring position according to the fluorescence signal obtained by the camera based on the fluorescence signal-temperature relation curve.

10. The method of claim 9, wherein step (1) comprises the steps of:

starting a second laser to excite a second working medium to be detected containing any two fluorescers to generate two fluorescences;

and enabling the two types of fluorescence to sequentially pass through the focusing lens and the third narrow-band light trapping sheet to enter a spectrum analyzer, and obtaining a change curve of the fluorescence intensity-laser irradiation relation of the two fluorescent agents according to the change of the fluorescence intensity along with time so as to select the light intensity of the second laser, the type and the concentration of the fluorescent agent.

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