Multispectral coal quality rapid testing method

Abstract

This invention relates to the field of detection technology and discloses a rapid multispectral coal quality testing method, including a sampling step, collecting sub-samples at intervals from the main coal flow; a pretreatment step, collecting and weighing each sub-sample using a pretreatment unit, and using a single sub-sample or multiple sub-samples combined into a material within a set mass range as the test sample; a shaping step, shaping the test sample to form a smooth coal layer; a detection step, performing multispectral detection on the test coal layer to obtain the corresponding spectral data; a data acquisition step, continuously acquiring the spectral data of each test sample and acquiring the instantaneous flow rate of the main coal flow in real time; and a calculation step, calculating the coal quality index data of each test sample, and using the mass of the main coal flow corresponding to each test sample as a weight to calculate the average quality value of the tested unit coal. This invention's rapid multispectral coal quality testing method controls the quality of coal samples and combines multispectral detection and a weighted algorithm to achieve accurate coal detection.

Description

Technical Field

[0001] This invention belongs to the field of detection technology, specifically relating to a rapid multispectral coal quality testing method. Background Technology

[0002] In related technologies, rapid coal testing methods typically involve directly testing the sampled coal through a rapid testing system. However, fluctuations in the main coal flow rate on the main conveyor belt during sampling can lead to significant variations in sample quality, resulting in inaccurate values ​​from the subsequent rapid testing system. Furthermore, after coal sample testing, the results for various indicators are often calculated as a weighted average of all subsamples from the same batch and their spectral acquisition time, which does not meet testing standards. Summary of the Invention

[0003] This invention aims to at least partially solve one of the technical problems in related technologies. To this end, embodiments of this invention propose a rapid multispectral coal quality testing method. This method controls the quality of coal samples and combines multispectral detection and a weighted algorithm to achieve accurate coal detection.

[0004] The multispectral coal quality rapid testing method of this invention is implemented using a multispectral coal quality rapid detection system. The system includes a preprocessing unit, a detection unit, a coal flow sensor, and a belt scale. The method includes a sampling step, in which sub-samples are collected at intervals from the main coal flow; a preprocessing step, in which each sub-sample is collected and weighed using the preprocessing unit, and a single sub-sample or multiple sub-samples combined to a set mass range are used as the test sample; a shaping step, in which the test sample is shaped to form a smooth coal seam; and a detection step, in which the test coal seam is subjected to multispectral detection to obtain the corresponding light... Spectral data; data acquisition step, continuously acquiring spectral data of each of the samples to be tested, and acquiring the instantaneous flow rate of the main coal flow in real time; calculation step, processing the spectral data of each of the samples to be tested, calculating the coal quality index data of each sample to be tested, and using the mass of the main coal flow corresponding to each sample to be tested as the weight, calculating the average quality value of the tested unit coal; wherein, the sampling time of the first subsample constituting the first sample to be tested is the sampling start time of the tested unit coal, and the sampling time of the last subsample constituting the last sample to be tested is the sampling end time of the tested unit coal.

[0005] The multispectral coal quality rapid testing method of this embodiment is adapted to the main coal flow conditions of belt conveyor, realizing online continuous and rapid detection of coal quality. On the one hand, it improves the representativeness and accuracy of coal quality detection results by limiting the quality of the test sample, and on the other hand, it improves the representativeness and accuracy of coal quality detection results by associating the test sample with the corresponding main coal flow quality and performing weighted calculation. Finally, the location limitation of the detection unit ensures the accuracy of the sample coal quality data, solving the problems of sampling quality fluctuation and large deviation between the results and the actual coal quality in traditional coal quality detection.

[0006] In some embodiments, the step of using a single subsample or multiple subsamples combined into a set mass range as the material to be tested specifically includes: if the weighing result of the subsample is less than a first threshold, then temporarily storing the subsample and merging it with one or more subsequent subsamples until the total mass of the merged sample is greater than or equal to the first threshold; if the weighing result of the subsample or the total mass of the merged sample is between the first threshold and a second threshold, then outputting all of the material as the material to be tested; if the weighing result of the subsample or the total mass of the merged sample is greater than the second threshold, then reducing the material so that the mass of the material to be tested after reduction is between the first threshold and the second threshold, and discarding the remaining portion.

[0007] In some embodiments, the first threshold is 5 kg and the second threshold is 15 kg.

[0008] In some embodiments, the shaping step includes spreading and compacting the coal sample using a spreading and compacting mechanism to form a coal layer to be inspected with a thickness of 3cm-10cm and a width of 10cm-30cm.

[0009] In some embodiments, the multispectral detection includes near-infrared spectral detection and laser-induced breakdown spectral detection performed sequentially along the transport direction using the detection unit, wherein the spectral data includes near-infrared reflectance spectra and laser-induced breakdown plasma spectra.

[0010] In some embodiments, the processing of spectral data specifically includes noise filtering, correction, normalization, and standardization of the spectral data, and calculating at least one coal quality index data among total moisture, ash, volatile matter, total sulfur, and calorific value from the processed spectral data.

[0011] In some embodiments, the step of weighting the average quality value of the tested unit coal by using the mass of the main coal flow corresponding to each tested sample as a weight specifically includes weighting the coal quality index data of all tested samples by using the mass of the main coal flow corresponding to each tested sample as a weight to obtain the average quality value of the tested unit coal; wherein, the mass of the main coal flow corresponding to the tested sample is obtained by time integration of the instantaneous flow rate of the main coal flow within the time period corresponding to the tested sample, wherein the time period starts at the sampling time of the last subsample that makes up the previous tested sample and ends at the sampling time of the last subsample that makes up the tested sample; wherein, for the first tested sample of the tested unit coal, its starting time is the sampling start time of the tested unit coal.

[0012] In some embodiments, a batch of coal includes at least one of the tested unit coals, and the average quality value of the batch of coal is derived by weighting the average quality values ​​of at least one of the tested unit coals by the amount of coal in each tested unit coal.

[0013] In some embodiments, the calculation step further includes excluding the coal quality index data of a preset number of the samples to be tested from the weighted calculation when the system is started or the coal type is changed.

[0014] In some embodiments, the instantaneous flow rate of the main coal stream is obtained from a coal flow sensor on the conveyor belt transporting the main coal stream; the coal quantity of the inspected unit is obtained by the cumulative value of the belt scale, or by integrating the instantaneous flow rate of the main coal stream over a period of time.

[0015] The multispectral coal quality rapid testing method of this invention accurately timestamps the spectral data of the sample to be tested with the instantaneous flow rate and cumulative mass of the main coal stream. Using the mass of the main coal stream corresponding to each sample as a weight, the average quality value of the tested unit coal and batch coal is calculated, ensuring a high degree of consistency between the test results and the actual coal quality of the main coal stream, significantly improving the representativeness and accuracy of the test results. Through the technical synergy of each step, the overall method completely solves the problems of large sample fluctuations and significant deviations between results and actual coal quality in traditional coal quality testing. It provides accurate and reliable real-time data support for dynamic quality control in coal storage, transportation, and processing, and is suitable for the needs of industrial-scale coal quality testing. Attached Figure Description

[0016] Figure 1 This is an overall schematic diagram of the multispectral coal quality rapid testing method according to an embodiment of the present invention.

[0017] Figure 2 This is an overall structural diagram of the multispectral coal quality rapid testing system in an embodiment of the present invention.

[0018] Figure 3This is a structural diagram of the shaping unit of the multispectral coal quality rapid testing system in this embodiment of the invention.

[0019] Figure 4 This is a schematic diagram of the laser detection area of ​​the multispectral coal quality rapid testing system in an embodiment of the present invention.

[0020] Figure label:

[0021] 1. Frame; 2. Conveying mechanism; 3. Pre-treatment unit; 31. Hopper; 32. Agitator; 33. Weighing module; 34. Distributor; 341. Discharge valve; 342. Distributor plate; 343. First channel; 344. Second channel; 4. Shaping unit; 41. Pressure roller; 42. Annular flange; 43. Guide plate; 44. Scraper; 5. Detection unit; 51. Near-infrared spectroscopy detection device; 52. Laser-induced breakdown spectroscopy detection device; 6. Clean up the module. Detailed Implementation

[0022] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0023] like Figures 1-4 As shown, the multispectral coal quality rapid testing method of this invention is implemented using a multispectral coal quality rapid detection system. The system includes a preprocessing unit 3, a detection unit 5, a coal flow sensor, and a belt scale. The method includes a sampling step, in which sub-samples are collected at intervals from the main coal flow; a preprocessing step, in which each sub-sample is collected and weighed using the preprocessing unit 3, and a single sub-sample or multiple sub-samples are combined to a set mass range as the sample to be tested; a shaping step, in which the sample to be tested is shaped to form a coal seam with a smooth surface; and a detection step, in which the coal seam to be tested is subjected to multispectral detection to obtain the corresponding... The process involves: acquiring spectral data of the samples to be tested; continuously acquiring spectral data of each sample to be tested and acquiring the instantaneous flow rate of the main coal flow in real time; processing the spectral data of each sample to be tested to calculate the coal quality index data of each sample to be tested, and weighting the average quality value of the tested unit coal by using the mass of the main coal flow corresponding to each sample to be tested as the weight; wherein, the sampling time of the first subsample constituting the first sample to be tested is the sampling start time of the tested unit coal, and the sampling time of the last subsample constituting the last sample to be tested is the sampling end time of the tested unit coal.

[0024] The multispectral coal quality rapid testing method of this embodiment is adapted to the main coal flow conditions of belt conveyor, realizing online continuous and rapid detection of coal quality. By associating the sample to be tested with the corresponding main coal flow quality and performing weighted calculation, the representativeness and accuracy of coal quality test results are improved. At the same time, the operation steps are closely connected, the detection process matches the rhythm of the main coal flow, and the average quality of the tested unit coal can be fed back in real time. This solves the problems of sampling quality fluctuation and large deviation between results and actual coal quality in traditional coal quality testing.

[0025] This rapid multispectral coal quality testing method is implemented using a rapid multispectral coal quality detection system. This system is equipped with a pretreatment unit 3, a detection unit 5, a coal flow sensor, a shaping unit 4, and a belt scale. It can also be used to build an integrated detection platform based on the control system, frame 1, and conveying mechanism 2 of the online multispectral coal quality detection system. The conveying mechanism 2 is a belt conveyor, linked to the conveyor belt transporting the main coal flow, ensuring continuous transport of coal samples between processes. The specific operating steps of this method are as follows: The sampling process involves collecting sub-samples at intervals from the main coal flow. The sampling interval can be flexibly set according to the conveying speed of the main coal flow and the frequency requirements of actual coal quality testing. The sampling process ensures the randomness and representativeness of sub-sample collection. After collection, the sub-samples are directly transported to the pre-processing unit 3 to complete the collection and temporary storage of sub-samples.

[0026] In the preprocessing step, the preprocessing unit 3 weighs each collected subsample. The preprocessing unit 3 has the functions of temporary storage, mixing and precise weighing of coal samples. Based on the subsample quality results obtained from the weighing, it selects to perform a single subsample output or multiple subsample merging operation, and finally obtains the material with the quality within the set range as the sample to be tested. The quality setting of the sample to be tested is based on the principle of meeting the subsequent shaping effect and detection accuracy. After the sample to be tested is formed, it is guided by the preprocessing unit 3 to the conveying mechanism 2 and conveyed to the shaping unit 4 along with the conveying mechanism 2.

[0027] In the shaping step, after the conveying mechanism 2 transports the sample to be inspected to the shaping unit 4, the shaping unit 4 performs a shaping operation on the loose sample. Through the synergistic effect of spreading and compaction, the sample is processed into a coal seam with a smooth surface. The smoothness of the coal seam can eliminate the interference of the unevenness of the coal sample surface on subsequent spectral detection, and ensure the stable incident and reflection of the detection light. After the shaping is completed, the coal seam continues to be transported by the conveying mechanism 2 and enters the detection area of ​​the detection unit 5.

[0028] The detection steps involve the detection unit 5 performing multispectral detection on the coal seam to be inspected, which is transported to the detection area. During the detection process, the conveying mechanism 2 maintains a stable conveying speed to ensure the continuity of the detection. The detection unit 5 captures the spectral characteristics of the coal seam to be inspected through multispectral detection and obtains spectral data related to coal quality. This spectral data is transmitted in real time to the system's control system for temporary storage and preliminary processing.

[0029] In the data acquisition step, the control system continuously receives and stores the spectral data of each sample to be tested transmitted by the detection unit 5. At the same time, it collects the instantaneous flow data of the main coal flow in real time through the coal flow sensor, and timestamps the spectral data and the instantaneous flow data to ensure that the spectral data of each sample to be tested can correspond to the specific flow period of the main coal flow. The belt scale simultaneously measures the cumulative coal quantity of the main coal flow to provide basic data support for subsequent weighted calculation.

[0030] The calculation process involves the control system first professionally processing the spectral data of each sample to be tested. Using a pre-set processing model (e.g., spectral data from multiple representative coal samples trained on an AI model) and algorithm, the system calculates the coal quality index data corresponding to each sample. Then, using the mass of the main coal flow corresponding to each sample as a weight, the system performs a weighted calculation of the coal quality index data for all samples to obtain the average quality value of the tested unit coal. In this process, a clear time definition standard for the tested unit coal is established. The sampling time of the first subsample constituting the first tested sample is taken as the start time of the tested unit coal sampling, and the sampling time of the last subsample constituting the last tested sample is taken as the end time of the tested unit coal. Based on this defined time period, the system accurately calculates the average quality value of the tested unit coal, achieving an overall evaluation of the coal quality of the tested unit coal within a specific time period.

[0031] In some specific embodiments, in order to further eliminate calculation bias, since the sampling of a single subsample has an operation time of 1-2 seconds and is not actually completed instantaneously, the sampling time of a single subsample can be uniformly defined as the start time of sampling or the end time of sampling.

[0032] In some embodiments, a single subsample or multiple subsamples combined into a set mass range are used as the material to be tested. Specifically, if the subsample weighing result is less than a first threshold, the subsample is temporarily stored and combined with one or more subsequent subsamples until the total combined mass is greater than or equal to the first threshold; if the subsample weighing result or the total combined mass is between the first threshold and a second threshold, the entire material is output as the material to be tested; if the subsample weighing result or the total combined mass is greater than the second threshold, the material is reduced in size so that the mass of the reduced material to be tested is between the first threshold and the second threshold, and the remaining part is discarded.

[0033] In some embodiments, the first threshold is 5 kg and the second threshold is 15 kg.

[0034] This embodiment achieves precise control over the quality of samples to be tested by defining the quality judgment thresholds for subsamples and merged subsamples and formulating differentiated material handling strategies. The optimal quality range of 5kg to 15kg is suitable for both the compaction and molding capabilities of the shaping unit 4 of the multispectral coal quality online detection system and the sample quantity requirements of the multispectral detection unit 5. This effectively avoids data distortion caused by insufficient sample quantity and substandard shaping caused by excessive sample quantity. It allows for seamless connection between material handling in the pretreatment stage and subsequent shaping and detection processes, significantly improving the stability of the detection process and the accuracy of the detection results.

[0035] In the multispectral coal quality rapid detection system relied upon in this embodiment, the pretreatment unit 3 is equipped with a hopper 31, a stirrer 32, a weighing module 33, and a material distribution device 34. The material distribution device 34 includes a discharge valve 341, a swingable material distribution plate 342, a first channel 343 facing the conveying mechanism 2, and a second channel 344 away from the conveying mechanism 2. The weighing module 33 can accurately measure the mass of the coal sample in the hopper 31, providing data basis for material processing. When performing the preprocessing step of taking a single subsample or merging multiple subsamples into a set mass range as the sample to be tested, a first threshold of 5 kg and a second threshold of 15 kg are set. Differential processing is applied in three cases: When the weighing module 33 detects that the weighing result of a single subsample is less than 5 kg, the discharge valve 341 is closed, and the subsample is temporarily stored in the hopper 31. The agitator 32 mixes the coal sample in the hopper 31 while continuing to receive one or more subsequent subsamples until the total mass of the merged subsamples in the hopper 31 is greater than or equal to 5 kg, at which point the discharge operation is initiated; When the weighing module 33 detects that the weighing result of a single subsample, or the total mass of multiple subsamples after merging and mixing, is between 5 kg and 15 kg, the discharge valve 341 is opened, and the distribution plate 342 swings to the first... The material in the hopper 31 is guided through the first channel 343 to the conveying mechanism 2 and directly transported to the shaping unit 4 as a sample to be inspected. When the weighing module 33 detects the weighing result of a single sample or the total mass of multiple samples after mixing is greater than 15kg, the discharge valve 341 is opened and the distribution plate 342 performs a reciprocating swing motion. By controlling the swing frequency and swing amplitude, the material in the hopper 31 is accurately divided so that the mass of the material falling to the conveying mechanism 2 through the first channel 343 is between 5kg and 15kg, which is used as a sample to be inspected. The remaining material discharged through the second channel 344 is treated as waste. After the division is completed, the distribution plate 342 is reset to the first position and the discharge valve 341 is closed, waiting for the collection and processing of the next batch of samples.

[0036] In some embodiments, the shaping step includes spreading and compacting the coal sample through a spreading and compacting mechanism to form a coal layer to be inspected with a thickness of 3cm-10cm and a width of 10cm-30cm.

[0037] This embodiment shapes the sample to be tested into a coal seam with a thickness of 3cm-10cm and a width of 10cm-30cm. This ensures that the size of the coal seam is precisely matched to the detection range of the multispectral detection probe in the detection unit 5. This guarantees that the light from near-infrared spectroscopy and laser-induced breakdown spectroscopy can uniformly and fully cover the detection surface of the coal seam. This eliminates the detection blind spots caused by excessively thick or wide coal seams, or the insufficient spectral data caused by excessively thin or narrow coal seams. At the same time, the standardized size of the coal seam matches the conveying rhythm of the conveying mechanism 2 and the compaction structure of the shaping unit 4, ensuring the stability of the conveying after the coal seam is formed. This avoids material breakage and collapse during the conveying process, providing a well-formed test sample for subsequent testing and improving the effectiveness of the spectral detection data.

[0038] In the multispectral coal quality rapid detection system relied upon in this embodiment, the shaping unit 4 is equipped with a pressure roller 41. The outer circumferential surface of the pressure roller 41 has at least two annular flanges 42, and multiple pressure rollers 41 are arranged sequentially along the conveying direction. The distance between the outer circumferential surface of at least some of the pressure rollers 41 and the bearing surface of the conveying mechanism 2 is adjustable. The shaping unit 4 is also equipped with a guide plate 43 and a scraper 44. During the shaping step, after the sample to be tested is conveyed to the area of ​​the shaping unit 4 by the conveying mechanism 2, it is first gathered towards the center of the conveying mechanism 2 by the guide plate 43 to prevent the coal sample from scattering to both sides. Then, it enters the compaction area of ​​the pressure roller 41. The rotating pressure roller 41 spreads and compacts the gathered coal sample. During the compaction process, the annular flanges 42 on the outer circumferential surface limit the width of the coal sample, ensuring that the width of the coal layer to be tested is limited. The coal sample is compressed stepwise along the conveying direction with a thickness controlled between 10cm and 30cm. By adjusting the interval between the pressure rollers 41 and the bearing surface of the conveying mechanism 2, and coordinating the stepwise compaction operation, the coal sample is gradually flattened and compacted. Finally, the thickness of the coal layer to be inspected after forming is precisely controlled between 3cm and 10cm, and the surface of the coal layer to be inspected is kept flat throughout the process. The scrapers 44, which correspond one-to-one with the pressure rollers 41, continuously scrape off the coal sample adhering to the outer circumference of the pressure rollers 41 to ensure the compaction effect of the pressure rollers 41. The formed, regular coal layer to be inspected continues to be conveyed to the testing unit 5 along with the conveying mechanism 2 and enters the subsequent testing stage.

[0039] In some embodiments, multispectral detection includes near-infrared spectral detection and laser-induced breakdown spectral detection performed sequentially along the transport direction using the detection unit 5, and the spectral data includes near-infrared reflectance spectrum and laser-induced breakdown plasma spectrum.

[0040] In some embodiments, the spectral data is processed, specifically including noise filtering, correction, normalization, and standardization of the spectral data, and the processed spectral data is used to calculate at least one coal quality index data among total moisture, ash, volatile matter, total sulfur, and calorific value.

[0041] This embodiment achieves multispectral detection by sequentially combining near-infrared spectroscopy and laser-induced breakdown spectroscopy. It combines the advantages of two spectral detection technologies: near-infrared spectroscopy can quickly capture the spectral characteristics of organic components in coal, while laser-induced breakdown spectroscopy can accurately detect the spectral information of inorganic elements. The two technologies complement each other, enabling comprehensive capture of coal quality characteristics. At the same time, a series of standardized processing steps, such as noise filtering and correction, are performed on the spectral data to effectively eliminate interference factors such as equipment and environment during the detection process, improve the effectiveness and consistency of the spectral data, and make the calculation results of coal quality indicators more accurate, providing high-quality data support for subsequent weighted calculations.

[0042] In the multispectral coal quality rapid detection system relied upon in this embodiment, the detection unit 5 is located on the frame 1 and downstream of the shaping unit 4. It includes a near-infrared spectral detection device 51 and a laser-induced breakdown spectral detection device 52 arranged sequentially along the conveying direction of the conveying mechanism 2. There is a gap between the near-infrared spectral detection device 51 and the laser-induced breakdown spectral detection device 52. The detection unit 5 is electrically connected to the control system. The system is also equipped with a cleaning module 6 for automatically blowing and cleaning the detection probe.

[0043] During the detection process, the coal seam to be inspected, after being processed by the shaping unit 4 and having a smooth surface, is conveyed at a constant speed by the conveying mechanism 2 to the detection area of ​​the detection unit 5. The coal seam to be inspected first passes through the near-infrared spectroscopy detection device 51, which emits near-infrared light to irradiate the detection surface of the coal seam to be inspected, and simultaneously receives the reflected light from the surface of the coal seam to be inspected and converts it into near-infrared reflectance spectral data. The data is transmitted to the control system in real time for temporary storage. The coal seam to be inspected continues to be conveyed forward by the conveying mechanism 2, and after passing through the interval between the two, it reaches the laser-induced breakdown spectroscopy detection device 52. This device emits a laser beam to break through the detection surface of the coal seam to be inspected to form plasma, and simultaneously captures the plasma spectrum and converts it into laser-induced breakdown plasma spectral data, which is also transmitted to the control system in real time to complete the multispectral detection of a single coal seam to be inspected. After the detection is completed, the cleaning module 6 immediately performs automatic blowing and cleaning of the detection probes of the near-infrared spectroscopy detection device 51 and the laser-induced breakdown spectroscopy detection device 52 to prevent coal dust from adhering and affecting the accuracy of subsequent detection.

[0044] In addition, to obtain more representative elemental distribution information, the laser-induced breakdown spectroscopy detection device 52 can employ various scanning acquisition structures. In one implementation, the detection probe of the laser-induced breakdown spectroscopy detection device 52 is mounted on a linear module and driven by a servo motor to reciprocate along the axial direction of the pressure roller 41. During the operation of the conveying mechanism 2, the detection probe reciprocates along the width direction of the coal seam to be inspected while being continuously fed along the conveying direction by the conveying mechanism 2. The combined motion of these two movements causes the laser focused spot to form an S-shaped scanning trajectory on the surface of the coal seam to be inspected. This S-shaped detection area can cover multiple locations along the width direction of the coal seam to be inspected, effectively avoiding sampling deviations caused by differences in elemental distribution between the edge and center of the coal seam. In another implementation, multiple laser-induced breakdown spectroscopy detection devices 52 are configured, with multiple detection probes arranged at intervals along the axial direction of the pressure roller 41. Each probe forms multiple parallel linear detection areas covering different locations along the width direction of the coal seam to be inspected, enabling a full-width scan in one operation. This is suitable for scenarios with high conveying speeds and high detection cycle requirements. As another implementation, the near-infrared spectroscopy detection device 51 and the laser-induced breakdown spectroscopy detection device 52 are jointly installed at the end of the multi-axis robotic arm. The robotic arm is set on one side of the frame 1. The control system drives the robotic arm to move the two sets of detection probes to any designated position above the coal seam to be inspected according to the location of the coal seam to be inspected, the coal type information, or the preset detection point. This structure is particularly suitable for offline single-sample detection or situations where there are local features on the surface of the coal seam to be inspected that require focused detection.

[0045] During the calculation process, when processing the acquired spectral data, the control system simultaneously processes the received near-infrared reflectance spectrum and laser-induced breakdown plasma spectrum data. First, noise filtering is performed on both types of spectral data, using algorithms to remove invalid information such as clutter and abnormal jumps generated during the detection process. Next, spectral correction is performed to eliminate detection errors caused by baseline drift and light intensity fluctuations. Subsequently, data normalization and standardization are sequentially completed to unify the dimensions and distribution range of different spectral data, eliminating systematic errors caused by different detection periods and minute morphological differences in the coal seam being inspected.

[0046] After completing the above processing, the control system uses the built-in processing model to extract features and perform analysis calculations on the optimized spectral data, and finally obtains at least one coal quality index data of the corresponding sample to be tested, including total moisture, ash, volatile matter, total sulfur and calorific value, providing accurate basic indicators for the subsequent weighted calculation of the average quality value of the tested unit coal.

[0047] In some embodiments, the weighted calculation of the average quality value of the tested unit coal, using the mass of the main coal flow corresponding to each sample as the weight, specifically includes weighting the coal quality index data of all samples to be tested using the mass of the main coal flow corresponding to each sample as the weight, to obtain the average quality value of the tested unit coal; wherein, the mass of the main coal flow corresponding to the sample is obtained by time integration of the instantaneous flow rate of the main coal flow within the time period corresponding to the sample, the time period starting from the sampling time of the last subsample that makes up the previous sample to be tested and ending at the sampling time of the last subsample that makes up the sample to be tested; wherein, for the first sample of the tested unit coal, its starting time is the sampling start time of the tested unit coal.

[0048] In some embodiments, the calculation step further includes excluding the coal quality index data of a preset number of samples to be tested from the weighted calculation when the system is started or the coal type is changed, for example, starting the calculation from the 5th sample to be tested.

[0049] The specific calculation method is as follows: Step 1: Calculate the average quality value of the tested coal unit. The total mass m of the main coal flow of the i-th sample to be tested is calculated using the following formula. i :

[0050] T a The sampling time is the last subsample that makes up the previous sample to be tested, where i=1 is the sampling start time of the coal sample of the tested unit.

[0051] T b The sampling time of the last subsample that makes up the i-th sample to be tested; G(t) is the instantaneous flow rate of the main coal stream; For each sample to be tested for which coal quality index data has been obtained, the average quality value of the tested unit coal is calculated using the following formula. :

[0052] Where, x i Let represent the coal quality index data for the i-th sample to be tested.

[0053] In some embodiments, a batch of coal includes at least one tested unit coal, and the average quality value of the batch of coal is derived by weighting the average quality value of at least one tested unit coal by the amount of coal in each tested unit coal.

[0054] The specific calculation method is as follows: The average quality value of a batch of coal is calculated as follows:

[0055] Among them, M j The coal quantity of the j-th inspected unit; j The average quality value of the j-th inspected coal unit; X This represents the average quality value of the batch of coal.

[0056] In some embodiments, the instantaneous flow rate of the main coal stream is obtained from a coal flow sensor on the conveyor belt transporting the main coal stream; the coal quantity of the inspected unit is obtained by the cumulative value of the belt scale, or by time-period integration of the instantaneous flow rate of the main coal stream.

[0057] In some special cases, if the flow rate M of the tested unit coal j While not directly obtainable, the coal flow rate of each inspected unit can be calculated through time integration. For example...

[0058] t a Let t be the starting time of the j-th inspected coal unit. b Let G(t) be the termination time of the j-th inspected coal unit, and let G(t) be the instantaneous coal flow rate of the main coal stream.

[0059] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0060] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0061] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between them; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to 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.

[0062] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0063] In this invention, the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0064] Although the above embodiments have been shown and described, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Any changes, modifications, substitutions and variations made to the above embodiments by those skilled in the art are within the protection scope of the present invention.

Claims

1. A rapid multispectral coal quality testing method, implemented using a rapid multispectral coal quality detection system, the system comprising a preprocessing unit, a detection unit, a coal flow sensor, a shaping unit, and a belt scale, characterized in that, include: The sampling procedure involves collecting sub-samples at intervals from the main coal flow. The pretreatment step involves collecting and weighing each of the subsamples using a pretreatment unit, and using a single subsample or a combination of multiple subsamples within a set mass range as the material to be tested. The shaping step involves shaping the sample to be inspected to form a coal seam with a smooth surface. The detection step involves performing multispectral detection on the coal seam to be inspected to obtain the corresponding spectral data; The data acquisition step involves continuously acquiring the spectral data of each of the samples to be tested, and acquiring the instantaneous flow rate of the main coal flow in real time. The calculation steps involve processing the spectral data of each of the test samples to obtain the coal quality index data of each test sample, and using the mass of the main coal flow corresponding to each test sample as the weight to calculate the average quality value of the tested unit coal. The sampling time of the first subsample that makes up the first sample to be tested is the starting time of the sampling of the tested unit coal, and the sampling time of the last subsample that makes up the last sample to be tested is the ending time of the tested unit coal.

2. The rapid multispectral coal quality testing method according to claim 1, characterized in that, The process of using a single subsample or multiple subsamples combined into a set quality range as the material to be tested specifically includes: If the weighing result of the subsample is less than the first threshold, the subsample is temporarily stored and merged with one or more subsequent subsamples until the total mass of the merged samples is greater than or equal to the first threshold. If the weighing result of the subsample or the total combined mass is between the first threshold and the second threshold, then all of the material will be output as samples to be tested. If the weighing result of the subsample or the total combined mass is greater than the second threshold, the material is reduced to a fraction such that the mass of the sample to be tested after reduction is between the first threshold and the second threshold, and the remaining part is discarded.

3. The rapid multispectral coal quality testing method according to claim 2, characterized in that, The first threshold is 5 kg, and the second threshold is 15 kg.

4. The rapid multispectral coal quality testing method according to claim 1, characterized in that, The shaping step includes spreading and compacting the coal sample through the shaping unit to form a coal layer to be inspected with a thickness of 3cm-10cm and a width of 10cm-30cm.

5. The rapid multispectral coal quality testing method according to claim 1, characterized in that, The multispectral detection includes near-infrared spectral detection and laser-induced breakdown spectral detection performed sequentially along the conveying direction using the detection unit. The spectral data includes near-infrared reflectance spectrum and laser-induced breakdown plasma spectrum.

6. The rapid multispectral coal quality testing method according to claim 5, characterized in that, The processing of spectral data specifically includes noise filtering, correction, normalization, and standardization of the spectral data, and the calculation of at least one coal quality index data among total moisture, ash, volatile matter, total sulfur, and calorific value from the processed spectral data.

7. The rapid multispectral coal quality testing method according to claim 1, characterized in that, The weighted calculation of the average quality value of the tested unit coal, using the mass of the main coal stream corresponding to each sample as a weight, specifically includes: Using the mass of the main coal flow corresponding to each of the tested samples as the weight, the coal quality index data of all the tested samples are weighted and averaged to obtain the average quality value of the tested unit coal. The mass of the main coal flow corresponding to the sample to be tested is obtained by integrating the instantaneous flow rate of the main coal flow within the time period corresponding to the sample to be tested. The time period starts at the sampling time of the last sub-sample that makes up the previous sample to be tested and ends at the sampling time of the last sub-sample that makes up the sample to be tested. For the first sample of the tested unit coal, its starting time is the sampling start time of the tested unit coal.

8. The rapid multispectral coal quality testing method according to claim 7, characterized in that, The batch of coal includes at least one of the tested unit coals, and the average quality value of the batch of coal is obtained by weighting the average quality values ​​of at least one of the tested unit coals according to the coal quantity of each tested unit coal.

9. The rapid multispectral coal quality testing method according to claim 8, characterized in that, The calculation steps also include excluding the coal quality index data of a preset number of the samples to be tested from the weighted calculation when the system is started or the coal type is changed.

10. The rapid multispectral coal quality testing method according to claim 9, characterized in that, The instantaneous flow rate of the main coal stream is obtained from the coal flow sensor on the conveyor belt transporting the main coal stream; The coal quantity of the inspected unit is obtained by the cumulative value of the belt scale, or by the time-period integration of the instantaneous flow rate of the main coal flow.

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