Hydrogen-doped natural gas jet combustion test device and test method

Abstract

The application discloses a hydrogen-doped natural gas injection combustion test device and a test method. The device comprises a mixing tank, a mixing module is arranged in the mixing tank, the mixing module is connected with a hydrogen storage tank and a natural gas storage tank respectively, an outlet end of the mixing tank is connected with a temporary storage tank, an outlet end of the temporary storage tank is provided with an injection combustion module, the test device further comprises an observation module and a controller, the observation module is used for collecting combustion characteristic parameters of an injection flame, and the controller is electrically connected with a hydrogen flowmeter, a natural gas flowmeter, a pressurizing module and the observation module. The application can input hydrogen-doped natural gas with any mixing ratio according to needs, improves the diversity of the test hydrogen-doped natural gas, separates a temporary storage area and a mixing area through the arrangement of the temporary storage tank, can simultaneously perform mixing operation while injection combustion, no longer needs to switch between different tank bodies, and no longer needs to prepare a large number of tank bodies for storing different hydrogen-doped natural gas, and the convenience of equipment operation is improved.

Description

Technical Field

[0001] This application relates to the field of combustion detection equipment technology, specifically to a hydrogen-blended natural gas injection combustion test device and test method. Background Technology

[0002] Hydrogen-blended natural gas (HCNG) is a mixture of hydrogen and natural gas in a certain proportion, representing an important direction for hydrogen energy utilization. The proportion of hydrogen-blended natural gas is typically between 3% and 30%, and it can be transported to end users directly via natural gas pipelines.

[0003] Due to the differences in the physicochemical properties of hydrogen and natural gas, the proportion of hydrogen blending needs to be strictly controlled. At the same time, in order to ensure the safe transportation of hydrogen-blended natural gas, its combustion properties need to be studied. In the existing technology, combustion tests of hydrogen-blended natural gas with different proportions are generally conducted through injection test devices. However, the above-mentioned injection combustion devices require multiple storage tanks to be prepared in advance to store hydrogen-blended natural gas with different blending proportions. When multiple blending proportions need to be tested, not only will the number of storage tanks increase indefinitely, but the switching between different storage tanks also requires complex control procedures, making the equipment inconvenient to use. Summary of the Invention

[0004] The main purpose of this application is to provide a hydrogen-blended natural gas injection combustion test device and test method, which aims to solve the defects of inconvenience in use in the prior art.

[0005] This application achieves the above objectives through the following technical solutions:

[0006] A hydrogen-blended natural gas injection combustion test apparatus, comprising:

[0007] A mixing tank is provided, and a mixing module is provided inside the mixing tank. The inlet end of the mixing module is connected to a hydrogen storage tank and a natural gas storage tank respectively. A hydrogen flow meter is also provided between the mixing module and the hydrogen storage tank, and a natural gas flow meter is provided between the mixing module and the natural gas storage tank.

[0008] A temporary storage tank, which is connected to the outlet end of the mixing tank via a pressurization module;

[0009] A jet combustion module, wherein the jet combustion module is connected to the temporary storage tank;

[0010] An observation module, which is used to acquire infrared temperature images of the jet flame;

[0011] The controller is electrically connected to the hydrogen flow meter, the natural gas flow meter, the pressurization module, and the observation module, respectively.

[0012] Optionally, the hybrid module includes an injection disc and an injection ring, the injection disc and the injection ring being coaxially arranged, the injection disc being provided with a first air inlet pipe for connecting to a hydrogen storage tank, and the injection ring being provided with a second air inlet pipe for connecting to a natural gas storage tank; the injection disc and the injection ring are provided with a plurality of injection heads.

[0013] Optionally, the temporary storage tank is also equipped with an internal circulation pipe, the inlet end of which is connected to the bottom of the temporary storage tank and the outlet end of which is connected to the top of the temporary storage tank; along the gas flow direction, a circulation pump and a mixing module are sequentially arranged on the internal circulation pipe.

[0014] Optionally, the mixing module includes a mixing tube, and a spiral guide vane coaxial with the mixing tube is provided inside the mixing tube. The surface of the spiral guide vane is provided with a plurality of interlaced mixing nails, and the cross-section of each mixing nail is arranged in a triangular structure.

[0015] Optionally, the injection combustion module includes an injection main pipe, a distribution plate, and several combustion tubes. The outlet end of the injection main pipe is connected to the distribution plate. The inlet end of each combustion tube is connected to the distribution plate, and the outlet end of each combustion tube is provided with the same or different nozzles.

[0016] Accordingly, this application also discloses a test method based on the above-mentioned test apparatus, including the following steps:

[0017] The blending ratio, injection pressure, and nozzle type of hydrogen-blended natural gas can be set as needed;

[0018] Acquire a set of infrared images of the jet flame;

[0019] Several temperature recognition thresholds are set, and several temperature distribution curve sets are extracted from the infrared image set according to the temperature recognition thresholds.

[0020] Several jet flame morphology diagrams were obtained based on the temperature distribution curve atlases described above;

[0021] The jet flame morphology parameters are obtained based on the jet flame morphology diagram.

[0022] Optionally, several temperature recognition thresholds are set, and several temperature distribution curve sets are extracted from the infrared image set according to the temperature recognition thresholds, including the following steps:

[0023] Several temperature recognition thresholds are set according to actual working conditions;

[0024] Retrieve the infrared image set and perform grayscale processing to obtain the grayscale image set of the jet flame;

[0025] Based on the temperature recognition thresholds described above, grayscale values ​​are calibrated to generate a grayscale-temperature conversion function.

[0026] The grayscale set to be identified is calculated based on the temperature recognition threshold and the grayscale-temperature conversion function.

[0027] Temperature distribution curves are extracted from the grayscale image set based on the identified grayscale set.

[0028] Optionally, grayscale values ​​are calibrated based on each temperature recognition threshold to generate a grayscale-temperature conversion function, including the following steps:

[0029] Obtain each temperature identification threshold, and determine the fitted temperature range based on each of the temperature identification thresholds;

[0030] Several test temperatures are randomly selected within the fitted temperature range;

[0031] Control the temperature of the adjustable blackbody furnace to any test temperature and capture an infrared temperature image at that test temperature;

[0032] Calculate the test grayscale value corresponding to the test temperature based on the infrared temperature image;

[0033] Repeat the process of controlling the temperature of the adjustable blackbody furnace to any test temperature to obtain all test grayscale values;

[0034] A grayscale-temperature conversion function is generated by fitting the test temperature and the test grayscale value.

[0035] Optionally, extracting a temperature distribution curve set from the grayscale image set based on the identified grayscale set includes the following steps:

[0036] Obtain any grayscale image from the grayscale image set;

[0037] The grayscale image is divided into several standard cells, and the actual grayscale value of each standard cell is marked.

[0038] Extract any identification grayscale value from the identification grayscale set;

[0039] Extract all standard cells whose actual grayscale value is equal to the identified grayscale value;

[0040] By connecting the extracted standard cells in a clockwise or counterclockwise direction via a curve, an identification temperature distribution curve is obtained, and these curves are then collected into the corresponding temperature distribution curve set.

[0041] Repeat the step of extracting any identification gray value from the identification gray set;

[0042] Repeat the step of obtaining any grayscale image from the grayscale image set to obtain several temperature distribution curve sets.

[0043] Optionally, several jet flame morphology diagrams are obtained based on the various temperature distribution curve atlases, including the following steps:

[0044] Obtain any of the temperature distribution curve sets mentioned above;

[0045] Each temperature distribution curve in the temperature distribution curve set is assigned a reference point;

[0046] A temperature distribution map is obtained by overlaying the temperature distribution curves based on the reference point.

[0047] Construct a minimum bounding box for the temperature distribution map, and take the center line of the minimum bounding box as the jet flame pattern.

[0048] Repeatedly obtain any of the temperature distribution curve sets to obtain several jet flame morphology diagrams.

[0049] Compared with the prior art, this application has the following beneficial effects:

[0050] This application includes a mixing tank, within which a mixing module is installed. The inlet of the mixing module is connected to a hydrogen storage tank and a natural gas storage tank, respectively. A hydrogen flow meter is installed between the mixing module and the hydrogen storage tank, and a natural gas flow meter is installed between the mixing module and the natural gas storage tank. The outlet of the mixing tank is connected to a temporary storage tank, and the outlet of the temporary storage tank is equipped with a jet combustion module. The experimental device also includes an observation module and a controller, wherein the observation module is used to collect combustion characteristic parameters of the jet flame; the controller is electrically connected to the hydrogen flow meter, the natural gas flow meter, the pressurization module, and the observation module, respectively.

[0051] In operation, the required amounts of hydrogen and natural gas are first calculated based on the hydrogen blending ratio. Then, hydrogen and natural gas are input into the mixing tank, and the mixing module achieves the mixing of hydrogen and natural gas. At the same time, the gas delivery volume is calculated by hydrogen flow meters and natural gas flow meters to control the blending ratio. After mixing, the gas is stored in a temporary storage tank and then injected and burned through the injection combustion module. During the injection process, the infrared temperature image of the injection flame is directly acquired by the observation module, and the relevant parameters of the injection flame are analyzed based on the infrared temperature image.

[0052] Compared with existing technologies, this application can input hydrogen-blended natural gas with any blending ratio as needed. On the one hand, it increases the diversity of hydrogen-blended natural gas for testing, which is beneficial to improving the accuracy of the test. On the other hand, due to the existence of the temporary storage tank, the temporary storage area and the blending area can be separated from each other. That is, the blending operation can be carried out simultaneously during injection combustion, eliminating the need to switch between different tanks or prepare a large number of different tanks for storing hydrogen-blended natural gas with different blending ratios. This improves the convenience of equipment operation and the response speed of the equipment. At the same time, it also simplifies the structure of the equipment and improves the reliability and stability of the entire system.

[0053] Meanwhile, this application produces hydrogen-blended natural gas through on-site blending, which can effectively avoid excessive amounts of hydrogen-blended natural gas at a certain blending ratio and improve gas utilization. Attached Figure Description

[0054] Figure 1 This is a schematic diagram of the structure of a hydrogen-blended natural gas injection combustion test device provided in Embodiment 1 of this application;

[0055] Figure 2 An exploded view of a hydrogen-blended natural gas injection combustion test apparatus provided in Embodiment 1 of this application;

[0056] Figure 3 This is a schematic diagram of the hybrid module.

[0057] Figure 4 This is an exploded view of the mixing module;

[0058] Figure 5 for Figure 4 Enlarged view of section A in the middle;

[0059] Figure 6 This is an exploded view of the jet combustion module;

[0060] Figure 7 A flowchart of the test method provided in Embodiment 2 of this application;

[0061] Figure 8 Schematic diagram for generating jet flame pattern;

[0062] Reference numerals: 1-Mixing tank, 2-Hydrogen storage tank, 3-Natural gas storage tank, 4-Hydrogen flow meter, 5-Natural gas flow meter, 6-Temporary storage tank, 7-Injection combustion module, 8-Observation module, 9-Controller, 10-Injection disc, 11-Injection ring, 12-First air inlet pipe, 13-Second air inlet pipe, 14-Injection head, 15-Internal circulation pipe, 16-Circulation pump, 17-Mixing pipe, 18-Spiral guide vane, 19-Mixing nail, 701-Injection main pipe, 702-Distribution disc, 703-Combustion pipe, 704-Nozzle.

[0063] The purpose, features, and advantages of this application will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0064] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0065] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present invention are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indication will also change accordingly.

[0066] In this invention, unless otherwise explicitly specified and limited, the terms "connection," "fixed," etc., should be interpreted broadly. For example, "fixed" can mean a fixed connection, a detachable connection, or an integral part; it can mean a mechanical connection or an electrical connection; it can mean a direct connection or an indirect connection through an intermediate medium; it can mean the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0067] Furthermore, if the embodiments of this invention involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the meaning of "and / or" throughout the text includes three parallel solutions; for example, "A and / or B" includes solution A, solution B, or a solution where both A and B are satisfied simultaneously. Furthermore, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this invention.

[0068] Implementation Method 1

[0069] Reference Figures 1 to 6This embodiment, as an optional embodiment of this application, discloses a hydrogen-blended natural gas injection combustion test device, including a mixing tank 1, a hydrogen storage tank 2, and a natural gas storage tank 3. A mixing module is also provided inside the mixing tube. The mixing module includes an injection disk 10 and an injection ring 11. The injection disk 10 has a cylindrical structure, and the injection ring 11 has a circular structure. The injection disk 10 is disposed inside the injection ring 11, and the injection disk 10 and the injection ring 11 are coaxially arranged.

[0070] The top surface of the injection disc 10 is also provided with a first air inlet pipe 12, and a second air inlet pipe 13 is connected to the injection ring 11. The inlet end of the first air inlet pipe 12 is connected to the hydrogen storage tank 2, and the inlet end of the second air inlet pipe 13 is connected to the natural gas storage tank 3.

[0071] Around the axis of the spray disk 10, a plurality of spray heads 14 are provided on the outer peripheral surface of the spray disk 10, and a plurality of spray heads 14 are also provided on the inner side surface of the spray ring 11. Each spray head 14 on the spray disk 10 corresponds one-to-one with each spray head 14 on the spray ring 11, and along the radial direction of the spray disk 10, two corresponding spray heads 14 are arranged facing each other.

[0072] Meanwhile, a hydrogen storage tank 2 is installed on the first air inlet pipe 12, and a natural gas flow meter 5 is installed on the second air inlet pipe 13;

[0073] In use, the flow rate of hydrogen and natural gas is measured by hydrogen flow meter 4 and natural gas flow meter 5 respectively, thereby achieving precise hydrogen blending. At the same time, since the nozzles 14 on the injection disc 10 and the nozzles 14 on the injection ring 11 are directly opposite each other, the hydrogen and natural gas ejected in high pressure will collide violently. The gas flow after the collision will achieve uniform mixing of itself, and the dispersed gas flow will also agitate the gas in the mixing tank 1, thereby achieving the mixing of the mixed gas in the tank.

[0074] Furthermore, the injection direction of each nozzle 14 can be adjusted to improve the stirring and mixing effect on the gas in the mixing tank 1.

[0075] Furthermore, a gas supply pipe is provided at the bottom of the mixing tank 1, and a pressurization module is provided on the gas supply pipe. The outlet end of the pressurization module is connected to the temporary storage tank 6; the pressurization module includes a pressurization pump.

[0076] Furthermore, an inner circulation pipe 15 is also provided on the temporary storage tank 6. The inlet end of the inner circulation pipe 15 is connected to the bottom of the temporary storage tank 6, and its outlet end is connected to the top of the temporary storage tank 6. Along the gas flow direction, a circulation pump 16 and a mixing module are sequentially arranged on the inner circulation pipe 15. The mixing module includes a mixing pipe 17. Along the axis of the mixing pipe 17, both ends of the mixing pipe 17 are connected to the outlet ends of the inner circulation pipe 15 and the circulation pump 16, respectively. A spiral guide vane 18 coaxial with the mixing pipe 17 is provided inside the mixing pipe 17, and a plurality of interlaced mixing nails 19 are provided on the surface of the spiral guide vane 18.

[0077] The cross-section of the mixing nail 19 is arranged in a triangular structure, with any edge of it facing the direction of airflow.

[0078] Furthermore, to improve the flow diversion effect, the two sides that intersect with the edge facing the airflow direction are designed with an arc-shaped structure;

[0079] In use, the airflow in the temporary storage tank 6 is forcibly drawn into the inner circulation pipe 15 by the circulation pump 16, and then through the mixing pipe 17. The spiral guide plate 18 can not only guide the direction of the airflow, but also prolong the residence time of the airflow in the mixing pipe 17, which is beneficial to improving the uniformity of mixing.

[0080] Secondly, the mixing nails 19 with triangular cross sections can cut the airflow, and the two airflows after being divided will flow in two different directions. At the same time, since the mixing nails 19 are staggered, airflow collision will occur in the blank area between the two mixing nails 19, further improving the uniformity of mixing.

[0081] The internal circulation pipe 15 effectively enhances the circulation of hydrogen-blended natural gas in the temporary storage tank 6, preventing a decrease in the uniformity of the hydrogen-blended natural gas during storage, thereby ensuring a relatively stable hydrogen concentration for the output of hydrogen-blended gas and guaranteeing the accuracy of the combustion test.

[0082] Furthermore, the outlet end of the temporary storage tank 6 is also connected to a jet combustion module. The jet combustion module includes a jet main pipe 701, a distribution plate 702, and a plurality of combustion pipes 703. The inlet end of the jet main pipe 701 is connected to the outlet end of the temporary storage tank 6, and its outlet end is connected to the distribution plate 702. The inlet end of each combustion pipe 703 is connected to the distribution plate 702, and the outlet end of each combustion pipe 703 is provided with the same or different nozzles 704.

[0083] Each of the combustion tubes 703 is equipped with a solenoid valve for adjusting its on / off state;

[0084] During use, staff can select nozzle 704 as needed to meet the test requirements. Compared with existing technologies, when it is necessary to switch between different nozzles 704, it can be achieved by adjusting the solenoid valve, eliminating the need for manual replacement of nozzle 704. This not only makes adjustment more convenient and improves test efficiency, but also effectively reduces the workload of staff.

[0085] Furthermore, both the temporary storage tank 6 and the mixing tank are equipped with combustion pipes 703 for burning excess hydrogen-blended natural gas. Additionally, a purge pipe is installed at the top of the temporary storage tank 6, with the inlet end of the purge pipe connected to an external purge nitrogen source.

[0086] When the combustion test of hydrogen-blended natural gas with a certain blending ratio is completed, if the hydrogen-blended natural gas in the temporary storage tank 6 is not completely consumed, the excess hydrogen-blended natural gas is discharged through the combustion pipe 703 and burned directly. Finally, nitrogen is introduced through the purging pipe to purge the residual hydrogen-blended natural gas in the temporary storage tank 6, thereby ensuring that the hydrogen-blended natural gas is output in a more precise blending ratio.

[0087] Meanwhile, corresponding sensors can be added to the outlet ends of the temporary storage tank 6 and the mixing tank to detect the mixing ratio of hydrogen; for example, a palladium alloy nanofilm hydrogen sensor can be added.

[0088] It should be noted that the device described in this application also needs to be equipped with devices such as pressure control devices. These devices are all conventional devices in the prior art and are widely used in technical fields such as natural gas transmission. Therefore, this application will not describe these devices again.

[0089] Furthermore, the experimental device also includes an observation module 8 and a controller 9, wherein the observation module 8 includes an infrared thermal imager; the controller 9 includes an industrial control computer and a PLC, the industrial control computer and the PLC are connected via a data bus, and the PLC is electrically connected to devices such as a hydrogen flow meter 4, a natural gas flow meter 5, a pressurization pump, and an infrared thermal imager, to realize data collection and automatic control.

[0090] Implementation Method 2

[0091] Reference Figure 7 This embodiment, as another optional embodiment of this application, discloses a method for testing the injection combustion of hydrogen-blended natural gas, including the following steps:

[0092] S1. Set the blending ratio, injection pressure, and nozzle type of hydrogen-blended natural gas as needed;

[0093] First, the blending ratio of hydrogen-blended natural gas is set according to the specific arrangements of the hydrogen blending test. At the same time, the injection pressure and burner nozzle type are set for each blending ratio of hydrogen-blended natural gas.

[0094] At the same time, the total amount of hydrogen-blended natural gas also needs to be set according to parameters such as combustion time;

[0095] S2. Acquire a set of infrared images of the jet flame;

[0096] Hydrogen and natural gas are delivered to the mixing tank according to the set blending ratio. The flow rate of hydrogen and natural gas is measured by hydrogen flow meter and natural gas flow meter respectively, so as to achieve precise hydrogen blending. At the same time, since the nozzles on the injection plate and the nozzles on the injection ring are directly opposite each other, the hydrogen and natural gas ejected in high pressure will collide violently. The gas flow after the collision will not only achieve uniform mixing, but the dispersed gas flow will also agitate the gas in the mixing tank, thereby achieving the mixing of the mixed gas in the tank.

[0097] After blending, the hydrogen-blended natural gas is transported to a temporary storage tank via a pressurization device, and then fed into the injection combustion module when an experiment is required.

[0098] During combustion, infrared temperature images of the jet flame are continuously collected at a certain sampling frequency, and a set of infrared temperature images is obtained for each experiment.

[0099] S3. Set several temperature recognition thresholds, and extract several temperature distribution curve sets from the infrared image set according to the temperature recognition thresholds;

[0100] S31. Set several temperature recognition thresholds according to actual working conditions;

[0101] Staff set several temperature recognition thresholds based on practical work experience, such as 1000℃, 1100℃, 1200℃, 1300℃, 1400℃ and 1500℃.

[0102] It should be noted that the temperatures mentioned above are just examples. The specific settings should be determined by the staff based on the actual situation. In addition, after setting the temperature, in order to ensure the accuracy of subsequent calculations, all temperatures need to be set with a certain upward adjustment percentage, such as 5%. Then the highest temperature recognition threshold will be increased by 5% based on the set value, and the lowest temperature recognition threshold will be decreased by 5%.

[0103] S32. Retrieve the infrared image set and perform grayscale processing on it to obtain the grayscale image set of the jet flame;

[0104] S33. Based on the temperature recognition thresholds described above, grayscale values ​​are calibrated to generate a grayscale-temperature conversion function;

[0105] S331. Obtain each temperature recognition threshold and determine the fitted temperature range based on each of the temperature recognition thresholds.

[0106] First, the temperature identification threshold set in step S31 is obtained, and then the temperature identification threshold is used to determine the fitting temperature range; for example, the fitting temperature range is set to 950℃-1600℃.

[0107] S332. Randomly select several test temperatures within the fitted temperature range;

[0108] Randomly select several temperature values ​​from the set fitting temperature range as test temperatures. It should be noted that the test temperatures are best selected according to a certain gradient, such as selecting in 5℃ increments.

[0109] S333: Control the temperature of the adjustable blackbody furnace to any test temperature and capture an infrared temperature image at that test temperature;

[0110] After the test temperature value is determined, the first test temperature is selected for testing. Then the temperature of the adjustable blackbody furnace is adjusted to the test temperature, and an infrared temperature image at the test temperature is captured by an infrared thermal imager.

[0111] It should be noted that the infrared thermal imager used in this step is the same device as the infrared thermal imager in the observation module, that is, the observation module is directly used in this step;

[0112] S334. Calculate the test grayscale value corresponding to the test temperature based on the infrared temperature image;

[0113] Extract the captured infrared temperature image, process it to obtain the corresponding grayscale image, calculate the grayscale value of the amplitude image, and use this grayscale value as the test grayscale value corresponding to the test temperature, thus obtaining a corresponding element group (T1, G1); where T1 represents the test temperature, G1 represents the test grayscale value, and 1 is the number.

[0114] S335. Repeat the step of controlling the temperature of the adjustable blackbody furnace to any test temperature to obtain all test grayscale values;

[0115] Repeating steps S333 and S334 will yield a series of test grayscale values, and simultaneously a series of corresponding element groups (T1, G1), (T2, G3), ..., (T...). n G n (), where n is the parameter number;

[0116] S336. Generate a gray-scale-temperature conversion function by fitting the test temperature and the test gray-scale value.

[0117] First, construct a two-dimensional coordinate system, where the X-axis represents the test temperature and the Y-axis represents the test grayscale value;

[0118] According to the element groups (T1, G1), (T2, G3), ..., (T) in step S335 n G n Points are selected in a two-dimensional coordinate system, and a fitting curve is obtained by computer fitting. The equation of the fitting curve is calculated, which is the gray-scale-temperature conversion function.

[0119] S34. Calculate the recognition grayscale set based on the temperature recognition threshold and the grayscale-temperature conversion function;

[0120] Obtain all temperature recognition thresholds, and substitute each of the temperature recognition thresholds into the grayscale-temperature conversion function to calculate the recognition grayscale set {G1', G2', G3', ..., G...}. i '}, where i represents the number used to identify grayscale values.

[0121] In the above steps, the blackbody test can be used to calibrate the equipment used in the observation module, thereby eliminating detection errors of different equipment as much as possible and improving the accuracy of identification.

[0122] S35. Extract a temperature distribution curve set from the grayscale image set based on the identified grayscale set.

[0123] S351. Obtain any grayscale image from the grayscale image set;

[0124] S352. Divide the grayscale image into several standard cells and mark the actual grayscale value of each standard cell;

[0125] The grayscale image is segmented using latitude and longitude lines to generate several standard cells. The area of ​​each standard cell is determined according to the calculation accuracy requirements, etc. The minimum standard cell is one pixel unit, and the number of standard cells is not less than 10,000.

[0126] Once the division is complete, each standard cell is numbered.

[0127] Simultaneously, the grayscale value of each standard cell is obtained, and these grayscale values ​​are used as the actual grayscale values ​​of the standard cells. The set of actual grayscale values ​​{G} is then output. 11 G 12 G 13 ... G ab}, where a represents the column number of the standard cell and b represents the row number of the standard cell;

[0128] S353. Extract any identification gray value from the identification gray set;

[0129] S354. Extract all standard cells whose actual grayscale value is equal to the recognized grayscale value;

[0130] Compare the identified grayscale value with each of the actual grayscale values. If the actual grayscale value is equal to the identified grayscale value, then the corresponding standard cell is retained on the divided grayscale image; otherwise, the standard cell is removed.

[0131] After comparing all elements in the actual grayscale value set, a series of standard cells with a certain distribution pattern will be obtained;

[0132] S355. Connect the extracted standard cells in a clockwise or counterclockwise direction using a curve to obtain the identified temperature distribution curve, and then collect them into the corresponding temperature distribution curve set.

[0133] First, generate the center point for each standard unit;

[0134] Then, the center points of each standard cell are connected by a curve in a clockwise or counterclockwise direction to obtain the temperature distribution identification curve;

[0135] Based on the temperature value corresponding to the identified grayscale value, the temperature distribution curve can be collected into the corresponding temperature distribution curve image set;

[0136] S356. Repeat the step of extracting any identification gray value from the identification gray set;

[0137] Repeating steps S351 to S355 will obtain all temperature distribution curves corresponding to the temperature recognition threshold. Based on the principle that one temperature recognition threshold corresponds to one set, a temperature distribution curve can be filled for each set.

[0138] S357. Repeat the step of obtaining any grayscale image from the grayscale image set to obtain several temperature distribution curve sets.

[0139] Repeating steps S351 to S356 will generate several temperature distribution curves based on each grayscale image in the grayscale image set.

[0140] Because the flame exhibits a certain degree of instability during the combustion process of the jet flame, meaning the flame will flicker, the above method can standardize a series of images of the jet flame during the stable combustion process, thereby obtaining more comprehensive image information of the flame, avoiding the impact of accidental factors on data analysis, and thus improving the accuracy and reliability of data analysis.

[0141] S4. Obtain several jet flame pattern diagrams based on the temperature distribution curve atlases described above.

[0142] S41. Obtain any of the temperature distribution curve sets mentioned above;

[0143] Since all temperature distribution curves in the same temperature distribution curve set correspond to the same temperature identification threshold, all temperature distribution curves under that temperature identification threshold can be obtained by extracting the temperature distribution curve set.

[0144] S42. Set reference points for each temperature distribution curve in the temperature distribution curve set;

[0145] A reference point is set at the same point on each of the temperature distribution curves. Preferably, the reference point is the flame nozzle.

[0146] S43. Overlay the temperature distribution curves according to the reference point to obtain a temperature distribution map;

[0147] Based on the reference point, the temperature distribution curves are superimposed, that is, the projections of the temperature distribution curves in the same direction are superimposed onto the same graph to obtain the temperature distribution graph.

[0148] S44. Construct the minimum bounding box for the temperature distribution map, and take the center line of the minimum bounding box as the jet flame pattern map;

[0149] Reference Figure 8 A minimum bounding box is generated for the temperature distribution map. Then, several radial dividing lines are randomly generated within the minimum bounding box. The midpoint of each radial dividing line is taken and connected by a smooth curve. The smooth curve is output as a jet flame pattern map.

[0150] The area between the two dashed lines in the figure represents the smallest bounding box, and the dotted line in the middle represents the jet flame pattern; the solid lines in the figure represent temperature distribution curves.

[0151] Due to the flickering of the flame, the temperature distribution of the jet flame is in a dynamic process of change. However, in the absence of external wind, the flickering amplitude of the jet flame is limited, that is, the change of the temperature distribution curve is concentrated within a certain range, which is the minimum bounding box.

[0152] The minimum bounding box can accurately delineate the temperature distribution range, and combined with the center line, the jet flame pattern can be quickly determined while minimizing the impact of detection errors and fluctuations, thus improving the accuracy of jet flame pattern extraction.

[0153] It should be noted that although the temperature distribution curve variation caused by flame jumping is a random event, under relatively stable external factors, the temperature distribution must follow the normal distribution law, that is, a large number of temperature distribution curves will be concentrated in the central region of the smallest bounding box, and the curves on both sides will gradually decrease. Based on the above principle, in order to further improve the accuracy of the results, in this step, temperature distribution curves that are significantly deviated from the central region can be removed by manual elimination, thereby reducing the smallest bounding box and improving the accuracy of the jet flame pattern diagram.

[0154] S45. Repeatedly obtain any of the temperature distribution curve sets to obtain several jet flame morphology diagrams.

[0155] S5. Obtain the jet flame morphology parameters based on the jet flame morphology diagram.

[0156] The jet flame morphology parameters are obtained from the jet flame morphology diagram, including flame length, aspect ratio, etc.

[0157] Compared with existing technologies, this application can input hydrogen-blended natural gas with any blending ratio as needed. On the one hand, it increases the diversity of hydrogen-blended natural gas for testing, which is beneficial to improving the accuracy of the test. On the other hand, due to the existence of the temporary storage tank, the temporary storage area and the blending area can be separated from each other. That is, the blending operation can be carried out simultaneously during injection combustion, eliminating the need to switch between different tanks or prepare a large number of different tanks for storing hydrogen-blended natural gas with different blending ratios. This improves the convenience of equipment operation and the response speed of the equipment. At the same time, it also reduces the structure of the equipment and improves the reliability and stability of the entire system.

[0158] Meanwhile, this application produces hydrogen-blended natural gas through on-site blending, which can effectively avoid excessive amounts of hydrogen-blended natural gas at a certain blending ratio and improve gas utilization.

[0159] The above are merely preferred embodiments of this application and do not limit the patent scope of this application. Any equivalent structural or procedural transformations made using the content of this application's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of this application.

Claims

1. A test method for a hydrogen-blended natural gas injection combustion test device, characterized in that, Includes the following steps: The blending ratio, injection pressure, and nozzle type of hydrogen-blended natural gas can be set as needed; Acquire a set of infrared images of the jet flame; Several temperature recognition thresholds are set, and several temperature distribution curve sets are extracted from the infrared image set according to the temperature recognition thresholds; wherein each temperature distribution curve in the same temperature distribution curve set corresponds to the same temperature recognition threshold. Obtain any of the temperature distribution curve sets mentioned above; Reference points are set on each temperature distribution curve in the temperature distribution curve atlas; A temperature distribution map is obtained by overlaying the temperature distribution curves based on the reference point. Construct a minimum bounding box for the temperature distribution map, randomly generate several radial dividing lines within the minimum bounding box, take the midpoint of each radial dividing line, connect the midpoints with a smooth curve to generate a center line, and output the center line as a jet flame pattern map. Repeat the steps of acquiring any of the temperature distribution curve sets to obtain several jet flame morphology diagrams; The jet flame morphology parameters are obtained based on the jet flame morphology diagram.

2. The test method according to claim 1, characterized in that, The process of setting several temperature recognition thresholds and extracting several temperature distribution curve sets from the infrared image set based on the temperature recognition thresholds includes the following steps: Several temperature recognition thresholds are set according to actual working conditions; Retrieve the infrared image set and perform grayscale processing to obtain the grayscale image set of the jet flame; Based on the temperature recognition thresholds described above, grayscale values ​​are calibrated to generate a grayscale-temperature conversion function. The grayscale set to be identified is calculated based on the temperature recognition threshold and the grayscale-temperature conversion function. Temperature distribution curves are extracted from the grayscale image set based on the identified grayscale set.

3. The test method according to claim 2, characterized in that, The step of calibrating grayscale values ​​based on various temperature recognition thresholds and generating a grayscale-temperature conversion function includes the following steps: Obtain each temperature identification threshold, and determine the fitted temperature range based on each of the temperature identification thresholds; Several test temperatures are randomly selected within the fitted temperature range; Control the temperature of the adjustable blackbody furnace to any test temperature and capture an infrared temperature image at that test temperature; Calculate the test grayscale value corresponding to the test temperature based on the infrared temperature image; Repeat the process of controlling the temperature of the adjustable blackbody furnace to any test temperature to obtain all test grayscale values; A grayscale-temperature conversion function is generated by fitting the test temperature and the test grayscale value.

4. The test method according to claim 2, characterized in that, The step of extracting a temperature distribution curve set from the grayscale image set based on the identified grayscale set includes the following steps: Obtain any grayscale image from the grayscale image set; The grayscale image is divided into several standard cells, and the actual grayscale value of each standard cell is marked. Extract any identification grayscale value from the identification grayscale set; Extract all standard cells whose actual grayscale value is equal to the identified grayscale value; By connecting the extracted standard cells in a clockwise or counterclockwise direction via a curve, an identification temperature distribution curve is obtained, and these curves are then collected into the corresponding temperature distribution curve set. Repeat the step of extracting any identification gray value from the identification gray set; Repeat the step of obtaining any grayscale image from the grayscale image set to obtain several temperature distribution curve sets.

Images