CN112014353A - Method and system for determining distribution of concentration field of hydrogen jet - Google Patents
Method and system for determining distribution of concentration field of hydrogen jet Download PDFInfo
- Publication number
- CN112014353A CN112014353A CN202010920827.XA CN202010920827A CN112014353A CN 112014353 A CN112014353 A CN 112014353A CN 202010920827 A CN202010920827 A CN 202010920827A CN 112014353 A CN112014353 A CN 112014353A
- Authority
- CN
- China
- Prior art keywords
- determining
- hydrogen
- light ray
- concentration
- concentration field
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
- 239000001257 hydrogen Substances 0.000 title claims abstract description 124
- 229910052739 hydrogen Inorganic materials 0.000 title claims abstract description 124
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 title claims abstract description 119
- 238000000034 method Methods 0.000 title claims abstract description 46
- 238000005259 measurement Methods 0.000 claims description 12
- 238000005516 engineering process Methods 0.000 abstract description 3
- 230000000007 visual effect Effects 0.000 abstract description 3
- 238000001514 detection method Methods 0.000 abstract description 2
- 239000007789 gas Substances 0.000 description 10
- 239000000523 sample Substances 0.000 description 8
- 238000005070 sampling Methods 0.000 description 6
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 4
- 239000001301 oxygen Substances 0.000 description 4
- 229910052760 oxygen Inorganic materials 0.000 description 4
- 238000010586 diagram Methods 0.000 description 3
- 238000006073 displacement reaction Methods 0.000 description 3
- 238000011088 calibration curve Methods 0.000 description 2
- 238000002485 combustion reaction Methods 0.000 description 2
- 238000001914 filtration Methods 0.000 description 2
- 238000003491 array Methods 0.000 description 1
- 238000009792 diffusion process Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 230000007613 environmental effect Effects 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 238000004880 explosion Methods 0.000 description 1
- 150000002431 hydrogen Chemical class 0.000 description 1
- 238000010348 incorporation Methods 0.000 description 1
- 238000000691 measurement method Methods 0.000 description 1
- 230000003287 optical effect Effects 0.000 description 1
- 238000012545 processing Methods 0.000 description 1
- 230000000750 progressive effect Effects 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 238000012360 testing method Methods 0.000 description 1
Images
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
- G01N21/17—Systems in which incident light is modified in accordance with the properties of the material investigated
- G01N21/41—Refractivity; Phase-affecting properties, e.g. optical path length
- G01N21/45—Refractivity; Phase-affecting properties, e.g. optical path length using interferometric methods; using Schlieren methods
- G01N21/455—Schlieren methods, e.g. for gradient index determination; Shadowgraph
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N33/00—Investigating or analysing materials by specific methods not covered by groups G01N1/00 - G01N31/00
- G01N33/0004—Gaseous mixtures, e.g. polluted air
- G01N33/0009—General constructional details of gas analysers, e.g. portable test equipment
- G01N33/0027—General constructional details of gas analysers, e.g. portable test equipment concerning the detector
- G01N33/0036—General constructional details of gas analysers, e.g. portable test equipment concerning the detector specially adapted to detect a particular component
- G01N33/005—H2
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
- G01N21/17—Systems in which incident light is modified in accordance with the properties of the material investigated
- G01N2021/1765—Method using an image detector and processing of image signal
- G01N2021/177—Detector of the video camera type
Landscapes
- Chemical & Material Sciences (AREA)
- Health & Medical Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- General Health & Medical Sciences (AREA)
- Analytical Chemistry (AREA)
- Biochemistry (AREA)
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Immunology (AREA)
- Pathology (AREA)
- Engineering & Computer Science (AREA)
- Combustion & Propulsion (AREA)
- Food Science & Technology (AREA)
- Medicinal Chemistry (AREA)
- Investigating Or Analysing Materials By Optical Means (AREA)
Abstract
The invention relates to a method and a system for determining the distribution of a hydrogen jet concentration field. The method and the system for determining the distribution of the hydrogen jet concentration field adopt the schlieren technology, determine the change of the light ray offset on the image based on the principle that the refractive index gradient of light in the measured flow field is in direct proportion to the airflow density of the flow field, combine gamma distribution and obtain the final concentration distribution of the hydrogen jet concentration field through calibration and correction of a sensor in a visual and accurate manner. In addition, in the method and the system for determining the concentration field distribution of the hydrogen jet, the concentration field distribution of the hydrogen jet can be determined only by adopting one concentration sensor, so that the problem of inaccurate detection result caused by the influence of multiple sensors on the flow field in the prior art is solved.
Description
Technical Field
The invention relates to the technical field of gas concentration measurement, in particular to a method and a system for determining distribution of a hydrogen jet concentration field.
Background
Energy-saving economy and environmental protection economy are the main economic characteristics of the current society. Hydrogen energy has drawn attention as a new energy source with its outstanding advantages of high combustion efficiency, clean combustion products, easy low-cost storage and transportation, and versatile use. Although hydrogen has the advantages of widest flammability range, fastest flame propagation speed and lowest ignition energy, the advantages are all safety hazards in the use process, and once leakage occurs, explosion is extremely easy to cause. Therefore, the research on the hydrogen leakage and diffusion stages is of great significance.
At present, the commonly used technologies for detecting hydrogen leakage include gas-sensitive methods, gas probe sampling methods, sensor arrays and the like. Among them, Sang Heon Han et al in the literature (Experimental information of high-pressure Hydrogen release through a small hole. International Journal of Hydrogen Energy,2014) measure the concentration of a Hydrogen jet using a gas probe sampling method, arrange a series of sampling probes at different positions along the jet centerline, and then use an ABB gas analyzer to determine the molar concentration of Hydrogen in a mixed gas sample. The gas probe sampling method was also used in The literature (The structure and flame propagation regions in structural hydrojets. International Journal of hydrojet Energy,2011) by Veser et al, while The PIV technique was used to measure The velocity field of The Hydrogen jet. A series of hydrogen leakage experiments were also conducted by uk shell oil company and health and safety laboratory, in which the oxygen concentration in the mixed gas was measured using an oxygen concentration sensor, and the hydrogen concentration in the mixed gas was reversely deduced by using the decrease in the oxygen concentration, assuming that the decrease in the oxygen in the mixed gas was entirely caused by the incorporation of hydrogen.
Based on the above, although most studies currently use a concentration sensor or a sampling probe to measure the concentration distribution of hydrogen leakage, more sensors or probes need to be arranged in the measurement process, which may cause certain damage to the flow field structure, and the measurement result is often axial distribution, which is not accurate enough for radial distribution calculation, and cannot obtain the data of the whole concentration field.
Therefore, it is an urgent technical problem to be solved in the art to provide a measurement method or system capable of accurately and intuitively determining the whole hydrogen jet concentration field data.
Disclosure of Invention
The invention aims to provide a method and a system for determining the distribution of a hydrogen jet concentration field, so as to accurately and intuitively determine the hydrogen concentration distribution condition of the whole flow field while reducing the influence of multiple sensors on the flow field.
In order to achieve the purpose, the invention provides the following scheme:
a method of determining a hydrogen jet concentration field distribution, comprising:
acquiring a schlieren image of a hydrogen jet concentration field by using a camera;
determining parameters according to the schlieren image; the parameters include: pixel location, shape parameter, and inverse scale parameter;
determining a first light ray offset according to the parameters by adopting a texture method; the first light ray offset is the light ray offset of a pixel in the schlieren image;
fitting the first light ray offset by gamma distribution to obtain the light ray offset of the measured cross section in the hydrogen jet flow concentration field;
acquiring a hydrogen concentration value of a set point in a hydrogen jet flow concentration field by using a concentration sensor;
and determining the concentration field distribution of the hydrogen jet according to the light ray offset of the measured section and the hydrogen concentration value of the set point.
Preferably, the acquiring a schlieren image of the hydrogen jet concentration field by using the camera specifically includes:
the light passing through the measurement area is cut at set steps using the knife edge assembly and a schlieren image is acquired at each step using the camera.
Preferably, the determining the first light ray offset according to the parameter by using a texture method specifically includes:
the texture image of the jet is measured by a schlieren method,taking the axial direction of the texture image distribution jet port as the y axis and the radial direction as the x axis, taking a certain radial section in the texture image, and obtaining the texture image according to a formula
Determining a first ray offset Δ l (x, y);
where y and x represent pixel locations, α (y) is a shape parameter, β is an inverse scale parameter, and [ ] is an infinite product function containing variables.
Preferably, the fitting of gamma distribution to the first light ray offset to obtain the light ray offset of the measured cross section in the hydrogen jet concentration field includes:
using a formula
Determining the light ray offset of the measured cross section in the hydrogen jet concentration field;
in the formula, n (x, y) is the light offset of the measured section, y and x represent the pixel position, α (y) is the shape parameter, β is the inverse scale parameter, and [ ] is the infinite product function containing parameter.
Preferably, the determining the concentration field distribution of the hydrogen jet according to the light ray offset of the measured cross section and the hydrogen concentration value of the set point comprises:
acquiring the light ray offset of a set point;
according to the light ray offset of the set point and the hydrogen concentration value of the set point, adopting a formula
Determining an initial value of the distribution of the concentration field; the set points are: the intersection point of the jet orifice axis and the cross section at the set position away from the jet orifice;
according to the light ray offset of the measured section and the initial value of the concentration field distribution, adopting a formula Cx＝CrelXn (x, y) determining the concentration field distribution of the hydrogen jet;
in the formula, C0As an initial value of the distribution of the concentration field, CrelHydrogen concentration value, n, as set point(x0,y0) Amount of light shift for set point, CxFor the concentration field distribution of the hydrogen jet, n (x, y) is the light ray offset of the measured cross section.
A system for determining a hydrogen jet concentration field distribution, comprising:
the schlieren image acquisition module is used for acquiring a schlieren image of the hydrogen jet concentration field by adopting a camera;
the parameter determining module is used for determining parameters according to the schlieren image; the parameters include: pixel location, shape parameter, and inverse scale parameter;
the first light ray offset determining module is used for determining a first light ray offset according to the parameters by adopting a texture method; the first light ray offset is the light ray offset of a pixel in the schlieren image;
the second light ray offset determining module is used for fitting the first light ray offset by means of gamma distribution to obtain the light ray offset of the measured cross section in the hydrogen jet flow concentration field;
the hydrogen concentration value determining module is used for acquiring a hydrogen concentration value of a set point in a hydrogen jet flow concentration field by adopting a concentration sensor;
and the concentration field distribution determining module is used for determining the concentration field distribution of the hydrogen jet according to the light ray offset of the measured cross section and the hydrogen concentration value of the set point.
Preferably, the schlieren image obtaining module includes:
and a schlieren image acquisition unit for cutting the light passing through the measurement area by a set step amount using the blade member, and acquiring a schlieren image at each step amount using the camera.
Preferably, the first light ray offset determining module specifically includes:
a first light ray offset determining unit for measuring the texture image of the jet flow by using a schlieren method, taking a certain radial section in the texture image by taking the axial direction of a texture image distribution jet flow port as a y axis and the radial direction as an x axis, and obtaining the radial section according to a formula
Determining a first ray offset Δ l (x, y);
where y and x represent pixel locations, α (y) is a shape parameter, β is an inverse scale parameter, and [ ] is an infinite product function containing variables.
Preferably, the second light ray offset amount determining module includes:
a second light ray offset determination unit for employing a formula
Determining the light ray offset of the measured cross section in the hydrogen jet concentration field;
in the formula, n (x, y) is the light offset of the measured section, y and x represent the pixel position, α (y) is the shape parameter, β is the inverse scale parameter, and [ ] is the infinite product function containing parameter.
Preferably, the concentration field distribution determining module includes:
a light offset acquisition unit for acquiring a light offset of a set point;
a concentration field distribution initial value determining unit for adopting a formula according to the light ray offset of the set point and the hydrogen concentration value of the set point
Determining an initial value of the distribution of the concentration field; the set points are: the intersection point of the jet orifice axis and the cross section at the set position away from the jet orifice;
a concentration field distribution determining unit for adopting formula C according to the light ray offset of the measured cross section and the initial value of the concentration field distributionx＝CrelXn (x, y) determining the concentration field distribution of the hydrogen jet;
in the formula, C0As an initial value of the distribution of the concentration field, CrelHydrogen concentration value, n (x), for set point0,y0) Amount of light shift for set point, CxFor the concentration field distribution of the hydrogen jet, n (x, y) is the light ray offset of the measured cross section.
According to the specific embodiment provided by the invention, the invention discloses the following technical effects:
the method and the system for determining the distribution of the hydrogen jet concentration field adopt the schlieren technology, determine the change of the light ray offset on the image based on the principle that the refractive index gradient of light in the measured flow field is in direct proportion to the airflow density of the flow field, combine gamma distribution and calibrate and correct through a sensor to visually and accurately determine the final concentration distribution of the hydrogen jet concentration field.
In addition, in the method and the system for determining the concentration field distribution of the hydrogen jet, the concentration field distribution of the hydrogen jet can be determined only by adopting one concentration sensor, so that the problem of inaccurate detection result caused by the influence of multiple sensors on the flow field in the prior art is solved.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings needed to be used in the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings without inventive exercise.
FIG. 1 is a flow chart of a method for determining a hydrogen jet concentration field distribution provided by the present invention;
FIG. 2 is a schematic structural diagram of a schlieren flow field display system according to an embodiment of the present invention;
FIG. 3 is a schematic view of gamma distribution in an embodiment of the present invention;
FIG. 4 is a diagram illustrating an optical offset according to an embodiment of the present invention;
FIG. 5 is a schematic structural diagram of a system for determining the concentration field distribution of a hydrogen jet in accordance with the present invention.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
The invention aims to provide a method and a system for determining the distribution of a hydrogen jet concentration field, so as to accurately and intuitively determine the hydrogen concentration distribution condition of the whole flow field while reducing the influence of multiple sensors on the flow field.
In order to make the aforementioned objects, features and advantages of the present invention comprehensible, embodiments accompanied with figures are described in further detail below.
Fig. 1 is a flowchart of a method for determining a hydrogen jet concentration field distribution according to the present invention, and as shown in fig. 1, a method for determining a hydrogen jet concentration field distribution includes:
step 100: and acquiring a schlieren image of the hydrogen jet concentration field by using a camera.
In this step 100, a schlieren flow field display system, which is commonly used in the prior art, is mainly used to collect the texture image. The detailed structure of the schlieren flow field display system is shown in fig. 2.
By adopting the display system, under the condition of no flow field, the knife edge position is adjusted by the knife edge component by a certain stepping amount delta a, and the schlieren image of each stepping amount is recorded by the high-speed camera. Then, with a flow field, an image is recorded with a high speed camera.
Step 101: parameters are determined from the schlieren image. The parameters include: pixel location, shape parameter, and inverse scale parameter.
Step 102: and determining the first light ray offset according to the parameters by adopting a texture method. The first light ray offset is a light ray offset of a pixel in the schlieren image.
The method specifically comprises the following steps: measuring texture image of jet flow by using schlieren method, taking the axial direction of texture image distribution jet flow port as y-axis and radial direction as x-axis, taking a certain radial section in texture image, and calculating the texture image according to formula
Determining a first light deviationThe amount of shift Δ l (x, y).
Where y and x represent pixel locations, α (y) is a shape parameter, β is an inverse scale parameter, and [ ] is an infinite product function containing variables.
Step 103: and fitting the first light ray offset by gamma distribution to obtain the light ray offset of the measured cross section in the hydrogen jet flow concentration field.
This step preferably comprises: using a formula
And determining the light ray offset of the measured section in the hydrogen jet concentration field.
In the formula, n (x, y) is the light offset of the measured section, y and x represent the pixel position, α (y) is the shape parameter, β is the inverse scale parameter, and [ ] is the infinite product function containing parameter.
Step 104: a concentration sensor is employed to obtain a hydrogen concentration value for a set point in the hydrogen jet concentration field.
Step 105: and determining the concentration field distribution of the hydrogen jet according to the light ray offset of the measured section and the hydrogen concentration value of the set point.
This step preferably comprises:
the light ray offset of the set point is obtained.
According to the light ray offset of the set point and the hydrogen concentration value of the set point, adopting a formula
And determining the initial value of the distribution of the concentration field. The set points are: an intersection of the ejection port axis and the cross section at the ejection port set position.
According to the light ray offset and the initial value of the concentration field distribution of the measured section, adopting a formula Cx＝CrelXn (x, y) determines the concentration field distribution of the hydrogen jet.
In the formula, C0As an initial value of the distribution of the concentration field, CrelHydrogen concentration value, n (x), for set point0,y0) Amount of light shift for set point, CxN (x, y) is the light ray offset of the measured cross section for the concentration field distribution of the hydrogen jet。
The following provides a detailed description of the embodiments of the invention.
A. Collecting a reference schlieren image and calibrating:
when no flow field disturbance exists in the measurement area of the schlieren system, the knife edge component adjusts the cutting amount of the knife edge by a certain stepping amount delta a, the knife edge is adjusted from the scale 0 of the knife edge until the maximum scale of the knife edge, the knife edge cuts the light rays passing through the measurement area, images with different light and shade can be finally presented, the series of schlieren images are recorded by a high-speed camera, because of external interference, uneven light and other factors, the image has certain background noise, therefore, firstly wiener filtering is carried out, then the gray value is extracted from the pixel of each image and the average value is obtained, the obtained average gray value and the stepping quantity are calibrated to obtain a calibration curve, finally the average value of the maximum value and the minimum value of the gray value is used as the reference gray value, and selecting a schlieren image with the gray value similar to that of the schlieren image as a reference image, wherein the knife edge position corresponding to the background image is the knife edge reference position.
B. Acquiring and measuring schlieren images:
the knife edge is adjusted to a knife edge reference position, a hydrogen jet flow field is placed in a test area of the schlieren system, a schlieren image of the flow field is obtained by a high-speed camera, and due to factors such as external interference and uneven light, the image has certain background noise. Through carrying out wiener filtering denoising processing on the image, a uniform image can be obtained.
Collecting concentration value C at a distance of 10cm from the jet orificerel。
A concentration sensor was disposed on the axis of the ejection port at a distance of 10cm from the ejection port to measure a concentration value C at that pointrelUsed as calibration
The light ray shift amount Δ l of the schlieren image is measured using gamma distribution (as shown in fig. 3) fitting.
Taking a certain radial section in an image from a measured schlieren image with the axial direction of a jet opening as the y axis and the radial direction as the x axis, extracting gray value information of the section, and obtaining the gray value information of the radial section according to the gray value on the radial sectionFinding out the knife edge displacement value corresponding to the calibration curve, subtracting the knife edge displacement value corresponding to the gray value of the background picture to obtain the relative displacement delta a of the knife edge, calculating the offset delta l of the light ray generated on the focal plane of the convergent lens,
wherein f is the focal length of the lens.
The delta l distribution image is in symmetrical distribution, and the first quadrant of the delta l distribution image approximately satisfies gamma distribution
According to the principle of schlieren method
Combination formula
The following can be obtained:
wherein,
n (x, y) -1 ═ k ρ (x, y), and k is a constant.
When gamma distribution fitting is carried out on different measured sections, a group of alpha is obtainediAnd betaiThe numerical value of (A):
wherein: theta is 21 DEG, alpha0Is a jet orificeWhere m is the number of fitted measured sections, alphaiIs the shape parameter of the i-th cross section, betaiIs the inverse scale parameter of the ith cross section, and Y is the maximum pixel position value.
Calculating the initial value C of the distribution of the concentration field0And obtaining a final concentration distribution curve, which specifically comprises the following steps:
according to the measured concentration value CrelCalculate C0Comprises the following steps:
the final concentration distribution of the measured section is as follows: cx＝CrelX n (x, y). In the present invention, the final concentration distribution results of the measured cross-section are shown in FIG. 4.
Aiming at the method for determining the distribution of the concentration field of the hydrogen jet, the invention also correspondingly provides a system for determining the distribution of the concentration field of the hydrogen jet. As shown in fig. 5, the system includes:
and the schlieren image acquisition module 1 is used for acquiring schlieren images of the hydrogen jet flow concentration field by adopting a camera.
And the parameter determining module 2 is used for determining parameters according to the schlieren image. The parameters include: pixel location, shape parameter, and inverse scale parameter.
And the first light ray offset determining module 3 is used for determining the first light ray offset according to the parameters by adopting a texture method. The first light ray offset is a light ray offset of a pixel in the schlieren image.
And the second light ray offset determination module 4 is used for fitting the first light ray offset by gamma distribution to obtain the light ray offset of the measured cross section in the hydrogen jet flow concentration field.
And the hydrogen concentration value determining module 5 is used for acquiring the hydrogen concentration value of the set point in the hydrogen jet flow concentration field by adopting a concentration sensor.
And the concentration field distribution determining module 6 is used for determining the concentration field distribution of the hydrogen jet according to the light ray offset of the measured section and the hydrogen concentration value of the set point.
Wherein, the schlieren image obtaining module 1 comprises:
and the schlieren image acquisition unit is used for cutting the hydrogen jet flow concentration field by adopting the knife edge part according to the set step amount and acquiring a schlieren image under each step amount by adopting the camera.
The first light ray offset determining module 3 specifically includes:
a first light ray offset determining unit for measuring the texture image of the jet flow by using a schlieren method, taking the axial direction of the texture image distribution jet flow port as the y axis and the radial direction as the x axis, taking a certain radial section in the texture image, and obtaining the radial section according to a formula
A first ray offset Δ l (x, y) is determined.
Where y and x represent pixel locations, α (y) is a shape parameter, β is an inverse scale parameter, and [ ] is an infinite product function containing variables.
The second light ray offset amount determining module 4 includes:
a second light ray offset determination unit for employing a formula
And determining the light ray offset of the measured section in the hydrogen jet concentration field.
In the formula, n (x, y) is the light offset of the measured section, y and x represent the pixel position, α (y) is the shape parameter, β is the inverse scale parameter, and [ ] is the infinite product function containing parameter.
The concentration field distribution determining module 6 includes:
and the light ray offset acquisition unit is used for acquiring the light ray offset of the set point.
A concentration field distribution initial value determining unit for determining the hydrogen concentration value of the set point according to the light ray offset of the set point and the formula
And determining the initial value of the distribution of the concentration field. The set points are: jet orifice axis and jet orifice distance setting positionThe intersection of the cross sections.
A concentration field distribution determining unit for adopting formula C according to the light ray offset and initial value of concentration field distribution of the measured cross sectionx＝CrelXn (x, y) determines the concentration field distribution of the hydrogen jet.
In the formula, C0As an initial value of the distribution of the concentration field, CrelHydrogen concentration value, n (x), for set point0,y0) Amount of light shift for set point, CxFor the concentration field distribution of the hydrogen jet, n (x, y) is the light ray offset of the measured cross section.
Compared with the prior art, the invention has the following advantages:
1. the invention realizes the visual measurement of the hydrogen jet concentration field by utilizing the schlieren technical principle, and realizes the visual measurement of the axial direction and the radial direction of the concentration field;
2. the invention adopts fewer sensors to correct data, reduces the interference of multiple sensors or sampling probes on a flow field, and has more accurate measurement result.
The embodiments in the present description are described in a progressive manner, each embodiment focuses on differences from other embodiments, and the same and similar parts among the embodiments are referred to each other. For the system disclosed by the embodiment, the description is relatively simple because the system corresponds to the method disclosed by the embodiment, and the relevant points can be referred to the method part for description.
The principles and embodiments of the present invention have been described herein using specific examples, which are provided only to help understand the method and the core concept of the present invention; meanwhile, for a person skilled in the art, according to the idea of the present invention, the specific embodiments and the application range may be changed. In view of the above, the present disclosure should not be construed as limiting the invention.
Claims (10)
1. A method of determining a hydrogen jet concentration field distribution, comprising:
acquiring a schlieren image of a hydrogen jet concentration field by using a camera;
determining parameters according to the schlieren image; the parameters include: pixel location, shape parameter, and inverse scale parameter;
determining a first light ray offset according to the parameters by adopting a texture method; the first light ray offset is the light ray offset of a pixel in the schlieren image;
fitting the first light ray offset by gamma distribution to obtain the light ray offset of the measured cross section in the hydrogen jet flow concentration field;
acquiring a hydrogen concentration value of a set point in a hydrogen jet flow concentration field by using a concentration sensor;
and determining the concentration field distribution of the hydrogen jet according to the light ray offset of the measured section and the hydrogen concentration value of the set point.
2. The method for determining the distribution of the concentration field of the hydrogen jet according to claim 1, wherein the acquiring the schlieren image of the concentration field of the hydrogen jet by using the camera specifically comprises:
the light passing through the measurement area is cut at set steps using the knife edge assembly and a schlieren image is acquired at each step using the camera.
3. The method of claim 1, wherein the determining the first light ray offset from the parameter using a texture method specifically comprises:
measuring texture image of jet flow by adopting a schlieren method, taking the axial direction of a jet flow port distributed by the texture image as a y axis and the radial direction as an x axis, taking a certain radial section in the texture image, and obtaining the texture image according to a formula
Determining a first ray offset Δ l (x, y);
where y and x represent pixel locations, α (y) is a shape parameter, β is an inverse scale parameter, and [ ] is an infinite product function containing variables.
4. The method of claim 1, wherein fitting the first light ray offset with a gamma distribution to obtain a light ray offset of a measured cross section in the hydrogen jet concentration field comprises:
using a formula
Determining the light ray offset of the measured cross section in the hydrogen jet concentration field;
in the formula, n (x, y) is the light offset of the measured section, y and x represent the pixel position, α (y) is the shape parameter, β is the inverse scale parameter, and [ ] is the infinite product function containing parameter.
5. A method of determining a hydrogen jet concentration field distribution according to claim 1, wherein determining a hydrogen jet concentration field distribution from the ray offset of the measured cross-section and the hydrogen concentration value of the set point comprises:
acquiring the light ray offset of a set point;
according to the light ray offset of the set point and the hydrogen concentration value of the set point, adopting a formula
Determining an initial value of the distribution of the concentration field; the set points are: the intersection point of the jet orifice axis and the cross section at the set position away from the jet orifice;
according to the light ray offset of the measured section and the initial value of the concentration field distribution, adopting a formula Cx＝CrelXn (x, y) determining the concentration field distribution of the hydrogen jet;
in the formula, C0As an initial value of the distribution of the concentration field, CrelHydrogen concentration value, n (x), for set point0,y0) Amount of light shift for set point, CxFor the concentration field distribution of the hydrogen jet, n (x, y) is the light ray offset of the measured cross section.
6. A system for determining a hydrogen jet concentration field distribution, comprising:
the schlieren image acquisition module is used for acquiring a schlieren image of the hydrogen jet concentration field by adopting a camera;
the parameter determining module is used for determining parameters according to the schlieren image; the parameters include: pixel location, shape parameter, and inverse scale parameter;
the first light ray offset determining module is used for determining a first light ray offset according to the parameters by adopting a texture method; the first light ray offset is the light ray offset of a pixel in the schlieren image;
the second light ray offset determining module is used for fitting the first light ray offset by means of gamma distribution to obtain the light ray offset of the measured cross section in the hydrogen jet flow concentration field;
the hydrogen concentration value determining module is used for acquiring a hydrogen concentration value of a set point in a hydrogen jet flow concentration field by adopting a concentration sensor;
and the concentration field distribution determining module is used for determining the concentration field distribution of the hydrogen jet according to the light ray offset of the measured cross section and the hydrogen concentration value of the set point.
7. The system for determining a hydrogen jet concentration field distribution according to claim 6, wherein the schlieren image acquisition module comprises:
and a schlieren image acquisition unit for cutting the light passing through the measurement area by a set step amount using the blade member, and acquiring a schlieren image at each step amount using the camera.
8. The system for determining a concentration field distribution of a hydrogen gas jet according to claim 6, wherein the first light ray offset determination module specifically comprises:
a first light ray offset determining unit for measuring the texture image of the jet flow by using a schlieren method, taking a certain radial section in the texture image by taking the axial direction of a texture image distribution jet flow port as a y axis and the radial direction as an x axis, and obtaining the radial section according to a formula
Determining a first ray offset Δ l (x, y);
where y and x represent pixel locations, α (y) is a shape parameter, β is an inverse scale parameter, and [ ] is an infinite product function containing variables.
9. The system for determining a hydrogen jet concentration field distribution according to claim 6, wherein the second light ray offset determination module comprises:
a second light ray offset determination unit for employing a formula
Determining the light ray offset of the measured cross section in the hydrogen jet concentration field;
in the formula, n (x, y) is the light offset of the measured section, y and x represent the pixel position, α (y) is the shape parameter, β is the inverse scale parameter, and [ ] is the infinite product function containing parameter.
10. The system for determining a concentration field distribution of a hydrogen gas jet according to claim 6, wherein the concentration field distribution determining module comprises:
a light offset acquisition unit for acquiring a light offset of a set point;
a concentration field distribution initial value determining unit for adopting a formula according to the light ray offset of the set point and the hydrogen concentration value of the set point
Determining an initial value of the distribution of the concentration field; the set points are: the intersection point of the jet orifice axis and the cross section at the set position away from the jet orifice;
a concentration field distribution determining unit for adopting formula C according to the light ray offset of the measured cross section and the initial value of the concentration field distributionx＝CrelXn (x, y) determining the concentration field distribution of the hydrogen jet;
in the formula, C0As an initial value of the distribution of the concentration field, CrelHydrogen concentration value, n (x), for set point0,y0) Amount of light shift for set point, CxFor the concentration field distribution of the hydrogen jet, n (x, y) is the light ray offset of the measured cross section.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010920827.XA CN112014353B (en) | 2020-09-04 | 2020-09-04 | Method and system for determining distribution of concentration field of hydrogen jet |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010920827.XA CN112014353B (en) | 2020-09-04 | 2020-09-04 | Method and system for determining distribution of concentration field of hydrogen jet |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN112014353A true CN112014353A (en) | 2020-12-01 |
| CN112014353B CN112014353B (en) | 2021-07-13 |
Family
ID=73516516
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202010920827.XA Active CN112014353B (en) | 2020-09-04 | 2020-09-04 | Method and system for determining distribution of concentration field of hydrogen jet |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN112014353B (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112505048A (en) * | 2021-02-02 | 2021-03-16 | 北京理工大学 | Testing device and method for calibrating hydrogen concentration |
| CN113295650A (en) * | 2021-05-28 | 2021-08-24 | 北京理工大学 | Hydrogen three-dimensional concentration testing device and testing method thereof |
| CN117928885A (en) * | 2024-03-25 | 2024-04-26 | 中国测试技术研究院 | Method for measuring density of flow field to be measured by multi-reflection lens schlieren automatic calibration |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB2416205A (en) * | 2004-07-16 | 2006-01-18 | Otsuka Denshi Kk | Method and apparatus for determining the amount of impurity in a gas |
| CN103454396A (en) * | 2013-09-06 | 2013-12-18 | 中国科学技术大学 | Test device for high-pressure combustible gas leakage spontaneous combustion and shock wave induction ignition |
| CN103940779A (en) * | 2014-04-13 | 2014-07-23 | 浙江大学 | Measurement method of gas injection flow field |
| CN106593718A (en) * | 2016-11-14 | 2017-04-26 | 江苏大学 | Dual-fuel jet research device combining schlieren technology and PIV technology and method thereof |
| CN207318044U (en) * | 2017-11-01 | 2018-05-04 | 四川物科光学精密机械有限公司 | A kind of parallel transmission flow field tubular type schlieren |
| CN110929460A (en) * | 2019-11-29 | 2020-03-27 | 福建龙净环保股份有限公司 | Flow field optimization method and system for flue evaporation process with zero discharge of desulfurization wastewater |
-
2020
- 2020-09-04 CN CN202010920827.XA patent/CN112014353B/en active Active
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB2416205A (en) * | 2004-07-16 | 2006-01-18 | Otsuka Denshi Kk | Method and apparatus for determining the amount of impurity in a gas |
| CN103454396A (en) * | 2013-09-06 | 2013-12-18 | 中国科学技术大学 | Test device for high-pressure combustible gas leakage spontaneous combustion and shock wave induction ignition |
| CN103940779A (en) * | 2014-04-13 | 2014-07-23 | 浙江大学 | Measurement method of gas injection flow field |
| CN106593718A (en) * | 2016-11-14 | 2017-04-26 | 江苏大学 | Dual-fuel jet research device combining schlieren technology and PIV technology and method thereof |
| CN207318044U (en) * | 2017-11-01 | 2018-05-04 | 四川物科光学精密机械有限公司 | A kind of parallel transmission flow field tubular type schlieren |
| CN110929460A (en) * | 2019-11-29 | 2020-03-27 | 福建龙净环保股份有限公司 | Flow field optimization method and system for flue evaporation process with zero discharge of desulfurization wastewater |
Non-Patent Citations (3)
| Title |
|---|
| JIANHUI ZHAO 等: ""Visualization research on influence of ambient pressure on CNG jet characteristics of gas injector with outward-opening nozzle"", 《FUEL》 * |
| SANG HEON HAN 等: ""Experimental investigation of highly pressurized hydrogen release through a small hole"", 《I N T E RNA T I ONAL JOURNAL O F HYDROGEN ENERGY》 * |
| 李雪芳 等: ""高压氢气小孔泄漏射流分层流动模型与验证"", 《清华大学学报(自然科学版)》 * |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112505048A (en) * | 2021-02-02 | 2021-03-16 | 北京理工大学 | Testing device and method for calibrating hydrogen concentration |
| CN113295650A (en) * | 2021-05-28 | 2021-08-24 | 北京理工大学 | Hydrogen three-dimensional concentration testing device and testing method thereof |
| CN117928885A (en) * | 2024-03-25 | 2024-04-26 | 中国测试技术研究院 | Method for measuring density of flow field to be measured by multi-reflection lens schlieren automatic calibration |
Also Published As
| Publication number | Publication date |
|---|---|
| CN112014353B (en) | 2021-07-13 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN112014353B (en) | Method and system for determining distribution of concentration field of hydrogen jet | |
| JP2007101508A (en) | Temperature measurement method and device | |
| CN108801164B (en) | Method and system for testing gap value of workpiece based on laser | |
| CN108692711B (en) | Method for realizing ocean data processing based on low-altitude sounding rocket | |
| Zhao et al. | Tools for the quantitative analysis of sedimentation boundaries detected by fluorescence optical analytical ultracentrifugation | |
| CN109060659A (en) | A kind of detection system and detection method of optical element surface defect three-dimensional information | |
| CN111089941A (en) | Formaldehyde detection device and detection method thereof | |
| CN109754406A (en) | Lithium battery pole slice burr detection device and method based on two-dimensional silhouette instrument | |
| US7051586B2 (en) | Method for determining aerodynamic parameters and method for detecting failure of a probe used for determining aerodynamic parameters | |
| CN105044039A (en) | Method for automatically inverting horizontal visibility according to laser radar data | |
| CN116862887A (en) | Quantitative detection method and system for gas leakage based on laser scanning and infrared imaging | |
| CN101169322A (en) | Concrete surface crack long distance photoelectric type digital detection system | |
| CN107796482A (en) | Liquid-level detecting method and liquid level detection device | |
| CN102520028B (en) | Method for digitally processing raw silk defects | |
| CN108414997B (en) | Boundary layer height inversion method based on particle characteristic difference | |
| CN106338253A (en) | Dam surface underwater collapse distributed optical fiber detection device and detection method | |
| Probst et al. | Nondestructive thickness determination of plastic pipes in a nearby industrial environment using terahertz time domain spectroscopy | |
| CN111929227B (en) | Switching method, device, equipment and storage medium of infrared detection pool | |
| CN110567899B (en) | Low-temperature compensation method for COD detection | |
| CN203053861U (en) | Light interference type methane concentration detector | |
| CN109633208A (en) | Air velocity transducer quality determining method and device | |
| Gu et al. | Research on the fractal model and calibration of the aerosol mass concentration measurement based on the particle group light scattering | |
| Innocenti et al. | Estimate of characteristic scales of atmospheric turbulence by thin beams: comparison between the von Karman and Hill-Andrews models | |
| Zhang et al. | Processing Jump Point of LIDAR Detection Data and Inversing the Aerosol Extinction Coefficient | |
| CN114720536B (en) | Mining toxic and harmful gas concentration detection method based on single-point calibration fitting algorithm |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |