OPTICAL DIAGNOSIS SYSTEM AND METHOD FOR IGNITION OF SINGLE-PARTICLE EXCAVATE WASTE

Description

CROSS REFERENCE TO THE RELATED APPLICATIONS

This application is based upon and claims priority to Chinese Patent Application No. 202411661794.6, filed on Nov. 20, 2024, the entire contents of which are incorporated herein by reference.

TECHNICAL FIELD

The present invention relates to the technical field of solid waste treatment, and more particularly to an optical diagnosis system and method for ignition of single-particle excavate waste.

BACKGROUND

The treatment of existing domestic waste (excavate waste) in landfills has become an important task of environmental protection, and the clean energy treatment of excavate waste is the key to reducing environmental pollution and carbon emissions. There are a lot of combustible substances in excavate waste, which can be converted into heat energy or electrical energy through combustion, thus achieving energy recovery and utilization. However, the excavate waste also produces greenhouse gases such as NOX and CO2 during the combustion process, causing harm to the environment and human health. Ignition is a key process in fuel combustion. In-depth understanding of the ignition characteristics of excavate waste can achieve ignition mode judgment, ignition parameter measurement, development and application of advanced clean combustion technology, optimization of combustion equipment design and operating parameters, improvement of combustion efficiency, reduction of energy consumption and pollutant emissions. Therefore, accurate diagnosis of the ignition process of excavate waste under different clean combustion technologies (such as moderate or intense low oxygen dilution (MILD) combustion and oxy-fuel combustion) is particularly important.

At present, a direct observation method is mostly adopted for ignition characteristic research, and the combustion video of particles of different types and sizes under different combustion conditions is recorded for analysis. However, this method has large human errors, and often faces problems such as unstable sample convey and particle shedding during the experiment, resulting in large uncertainty in the experimental results and poor repeatability.

Therefore, how to provide an optical diagnosis system and method for ignition of single-particle excavate waste, which reduces human operation errors, improves the stability of sample transportation, ensures the stability of experiments, and achieves high-precision judgment of an ignition moment of single-particle excavate waste is a problem required to be solved urgently by those skilled in the art.

SUMMARY

In view of this, the present invention provides an optical diagnosis system and method for ignition of single-particle excavate waste, which reduces human operation errors, improves the stability of sample transportation, ensures the stability of experiments, and achieves high-precision judgment of an ignition moment of single-particle excavate waste. To achieve the above objective, the present invention adopts the following technical solutions. An optical diagnosis system for ignition of single-particle excavate waste includes an excavate waste combustion device, an excavate waste feeding device, an oxidant supply device, a flow monitoring device, an observation device and a flue gas analysis device; wherein the excavate waste feeding device cooperates with the excavate waste combustion device, the oxidant supply device is connected to the excavate waste combustion device via the flow monitoring device, the flue gas analysis device is connected to the excavate waste combustion device, and the observation device cooperates with the excavate waste combustion device.

Optionally, the excavate waste combustion device includes a furnace, a shell, a fuel conveying channel, an oxidant channel, a visualization window and a flue gas channel, the furnace is fixedly arranged inside the shell, a top of the furnace is connected to the fuel conveying channel, a bottom of the furnace is in sealing connection with the oxidant channel, the visualization window is formed on a side wall of the shell, and the flue gas channel is connected to the fuel conveying channel.

Optionally, the excavate waste feeding device includes a slide rail bracket, a hoisting tray, a high temperature resistant iron wire, a high temperature resistant corundum tube and a K-type thermocouple, the high temperature resistant corundum tube is connected to the slide rail bracket, one end of the high temperature resistant iron wire is connected to the high temperature resistant corundum tube, the other end of the high temperature resistant iron wire is connected to the hoisting tray, and the K-type thermocouple is fixed in the corundum tube.

Optionally, the optical diagnosis system further includes a furnace temperature display, and the furnace temperature display is mounted on the shell for displaying internal temperature information of the furnace.

Optionally, the optical diagnosis system further includes a temperature sensor arranged inside the furnace and used to monitor a temperature inside the furnace and in signal connection with the furnace temperature display.

Optionally, the optical diagnosis system further includes a K-type thermocouple temperature display, the K-type thermocouple temperature display is mounted on the shell, and the K-type thermocouple temperature display is in signal connection with the K-type thermocouple and is used to display temperature changes of the K-type thermocouple.

Optionally, the flue gas analysis device is a flue gas analyzer, the flue gas analyzer is connected to the flue gas channel, and the flue gas analyzer is used to detect a concentration of pollutants generated in a combustion process of the excavate waste.

Optionally, the flow monitoring device is a mass flow meter.

Optionally, a flow stabilizing plate is also fixedly connected to a top of the oxidant channel, and the flow stabilizing plate is used to stabilize airflow distribution in a combustion process.

Optionally, the observation device includes a high-speed camera and a computer, the high-speed camera is in signal connection with the computer, the high-speed camera is used to capture images inside the visualization window, and the high-speed camera is placed parallel to the visualization window.

Optionally, an optical diagnosis method for ignition of single-particle excavate waste includes:

• • placing excavate waste particles on a hoisting tray, and fixing by using high temperature resistant inorganic glue;
  • when a temperature in a furnace reaches a preset value, conveying a particle sample to a visualization window by a slide rail bracket;
  • starting a high-speed camera to capture an image of a moment when the excavate waste particles are ignited; and
  • processing the image of the ignition process, including smoothing, differential processing and brightness enhancement, screening out an image of an ignition moment with a precision of 10 us to 1 ms, and performing ignition mode judgment and ignition delay time parameter measurement.

It can be known from the technical solutions that, compared with the prior art, the present invention provides an optical diagnosis system and method for ignition of single-particle excavate waste, which has the following beneficial effects.

The present invention provides an optical diagnosis system for ignition of single-particle excavate waste, which includes an excavate waste combustion device, an excavate waste feeding device, an oxidant supply device, a flow monitoring device, an observation device and a flue gas analysis device; wherein the excavate waste feeding device cooperates with the excavate waste combustion device, the oxidant supply device is connected to the excavate waste combustion device via the flow monitoring device, the flue gas analysis device is connected to the excavate waste combustion device, and the observation device cooperates with the excavate waste combustion device. According to the present invention, the excavate waste particles are automatically conveyed through the slide rail bracket, so that the manual operation error is reduced, the stability of sample conveying is improved, and the operability and repeatability of an experiment are significantly improved; according to the characteristics (such as easy expansion and high looseness) of the excavate waste fuel, the phenomenon that particles fall off due to thermal expansion is avoided by adopting the hoisting tray, so that the stability of an experiment is ensured; a flow stabilizing plate is added at the bottom of the combustion device to allow the oxidant gas to enter the furnace evenly through multiple channels, which ensures the stability of the combustion process and is more conducive to capturing the ignition moment; and image enhancement processing is performed by a Python program on a captured image, including image smoothing, differential processing and brightness enhancement, to accurately screen out a moment when the luminous flame first appears, thereby achieving high-precision judgment of the ignition moment.

BRIEF DESCRIPTION OF THE DRAWINGS

To more clearly illustrate the technical solutions in the embodiments of the present invention or in the prior art, the drawings required to be used in the description of the embodiments or the prior art are briefly introduced below. It is obvious that the drawings in the description below are merely embodiments of the present invention, and those of ordinary skill in the art can obtain other drawings according to the drawings provided without creative efforts.

FIG. 1 is a framework diagram of a structure of an optical diagnosis system for ignition of single-particle excavate waste according to the present invention.

FIG. 2 is a schematic diagram of a structure of an excavate waste feeding device according to the present invention.

FIG. 3 is a schematic diagram of a structure of a hoisting tray of an excavate waste feeding device according to the present invention.

FIG. 4 is a schematic diagram of a structure of a flow stabilizing plate of a visual excavate waste combustion device according to the present invention.

In the drawings, 1: fuel conveying channel; 2: furnace temperature display; 3: K-type thermocouple temperature display; 4: furnace; 5: flow stabilizing plate; 6: excavate waste particle; 7: visualization window; 8: high-speed camera; 9: flue gas channel; 10: flue gas analyzer; 11: computer; 12: mass flow meter; 13: oxidant supply device; 14: excavate waste feeding device; and 131: hoisting tray.

DETAILED DESCRIPTION OF THE EMBODIMENTS

The following clearly and completely describes the technical solutions in the embodiments of the present invention with reference to drawings in the embodiments of the present invention. It is clear that the described embodiments are merely a part rather than all of the embodiments of the present invention. Based on the examples of the present invention, all other examples obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

An embodiment of the present invention discloses an optical diagnosis system for ignition of single-particle excavate waste, as shown in FIG. 1, which includes an excavate waste combustion device, an excavate waste feeding device 14, an oxidant supply device 13, a flow monitoring device, an observation device and a flue gas analysis device; wherein the excavate waste feeding device 14 cooperates with the excavate waste combustion device, the oxidant supply device 13 is connected to the excavate waste combustion device via the flow monitoring device, the flue gas analysis device is connected to the excavate waste combustion device, and the observation device cooperates with the excavate waste combustion device.

Further, the excavate waste combustion device includes a furnace 4, a shell, a fuel conveying channel 1, an oxidant channel, a visualization window 7 and a flue gas channel 9, the furnace 4 is fixedly arranged inside the shell, a top of the furnace is connected to the fuel conveying channel 1, a bottom of the furnace is in sealing connection with the oxidant channel, the visualization window 7 is formed on a side wall of the shell, and the flue gas channel 9 is connected to the fuel conveying channel 1.

Further, as shown in FIGS. 2 and 3, the excavate waste feeding device 14 includes a slide rail bracket, a hoisting tray 131, a high temperature resistant iron wire, a high temperature resistant corundum tube and a K-type thermocouple, the high temperature resistant corundum tube is connected to the slide rail bracket, one end of the high temperature resistant iron wire is connected to the high temperature resistant corundum tube, the other end of the high temperature resistant iron wire is connected to the hoisting tray, and the K-type thermocouple is fixed in the corundum tube.

In a specific embodiment, the working principle of the excavate waste feeding device 14 includes: a fixed platform, a first vertical telescopic pull rod, a second vertical telescopic pull rod and a first transverse pull rod, wherein a fixed block is mounted at a top of the first vertical telescopic pull rod, the first vertical telescopic pull rod is connected to the first transverse pull rod by the fixed block, and the first vertical telescopic pull rod can move up and down in a telescopic mode and is used to convey fuel particles to a specified position (a center of the visualization window 7). A telescopic joint of the first vertical telescopic pull rod can rotate; and after a conveying distance is determined by the first vertical telescopic pull rod, the second vertical telescopic pull rod is positioned by telescoping the second vertical telescopic pull rod, and the second vertical telescopic pull rod abuts against the first transverse pull rod during positioning. After positioning, there is no need to reposition in each experiment. After placing the sample into the hoisting tray 131, the sample can be directly moved vertically downward by the fixed block, and the first transverse pull rod is pulled to the position of the second vertical telescopic pull rod, so that the fuel particles are exactly at the visualization window 7. The pull rod is set to be telescopic to facilitate height adjustment. Meanwhile, since the hoisting tray 131 needs to be conveyed to the center of the furnace (window), a distance from an entrance of the fuel conveying channel 1 to the center of the furnace 4 changes with the excavate waste combustion device and is not a fixed value, so that the telescopic pull rod is arranged.

Specifically, the high temperature resistant corundum tube is a corundum tube with 99% alumina purity, the high temperature resistant iron wire is a nickel-chromium alloy heating wire, and the hoisting tray 131 is made of nickel-chromium alloy mesh 2080, which has high temperature resistance and corrosion resistance, and ensures stable loading of particles. The slide rail bracket is used to deliver single-particle excavate waste 6 into the furnace, the hoisting tray 131 supports the waste particles, the high temperature resistant iron wire connects the hoisting tray and the high temperature resistant corundum tube, the high temperature resistant corundum tube is used to isolate the K-type thermocouple from the high temperature resistant iron wire to ensure that the temperature measurement accuracy is not affected, and the K-type thermocouple is used to measure the flame temperature during the combustion process.

Further, the optical diagnosis system also includes a furnace temperature display 2, and the furnace temperature display 2 is mounted on the shell for displaying internal temperature information of the furnace.

Further, in the oxidant supply device 13, the oxidant supply device 13 includes oxygen, carbon dioxide and nitrogen supply devices for providing different atmospheres required by combustion, so as to study various combustion conditions. The oxygen supply device is an oxygen cylinder, the carbon dioxide supply device is a carbon dioxide cylinder, and the nitrogen supply device is a nitrogen cylinder, which are used to adjust the combustion atmosphere and achieve ignition under various clean combustion technologies, such as MILD combustion and oxy-fuel combustion.

Further, the optical diagnosis system also includes a K-type thermocouple temperature display 3, the K-type thermocouple temperature display 3 is mounted on the shell, and the K-type thermocouple temperature display 3 is in signal connection with the K-type thermocouple and is used to display temperature changes of the K-type thermocouple.

Further, the flue gas analysis device is a flue gas analyzer 10, the flue gas analyzer 10 is connected to the flue gas channel 9, and the flue gas analyzer 10 is used to detect a concentration of pollutants generated in a combustion process of the excavate waste and detect components of tail gas discharged in a combustion process.

Further, the flow monitoring device is a mass flow meter 12.

Further, as shown in FIG. 4, a flow stabilizing plate 5 is also fixedly connected to a top of the oxidant channel, and the flow stabilizing plate 5 is used to stabilize airflow distribution in a combustion process, so as to ensure uniform combustion conditions.

Further, the observation device includes a high-speed camera 8 and a computer 11, the high-speed camera 8 is in signal connection with the computer 11, the high-speed camera 8 is used to capture images inside the visualization window 7, and the high-speed camera 8 is placed parallel to the visualization window 7 and is used to capture a moment when the excavate waste particles 6 in the furnace 4 are ignited in real time, so as to ensure the accuracy and integrity of optical diagnosis data.

In a specific embodiment, the high-speed camera 8 is used to capture an image of a moment when the excavate waste particles 6 are ignited; and the flue gas analyzer is used to detect the concentration of pollutants such as NO_X generated in the combustion process of the excavate waste particles 6. The fuel conveying channel 1 is used to convey excavate waste particles 6, the oxidant channel is used to provide gas required by a combustion atmosphere, the visualization window 7 is used to provide an observation window for optical measurement, and the flue gas channel 9 is connected to the flue gas analyzer 10 and used to detect the emission concentration of combustion pollutants.

In a specific embodiment, an optical diagnosis method for ignition of single-particle excavate waste includes:

• • placing excavate waste particles 6 on a hoisting tray 131, and fixing by using high temperature resistant inorganic glue to ensure the stability of the particles in the combustion process;
  • when an average temperature in a furnace 4 reaches a preset value, conveying a particle sample to a visualization window 7 by a slide rail bracket;
  • starting a high-speed camera 8 to capture an image of a moment when the excavate waste particles 6 are ignited; and
  • processing the image of the ignition process, including smoothing, differential processing and brightness enhancement, screening out an image of an ignition moment with a precision of 10 us to 1 ms, and performing ignition mode judgment and ignition delay time parameter measurement.

In a specific embodiment, the collected images are processed by computer software, and the captured images are processed by a Python program in an image enhancement processing method. Firstly, an original image is smoothed; the smoothed image is differentially processed with the original image, and a part less than a threshold is set to 0; the differentiated image is added to the smoothed result; then the mean and standard deviation are calculated, and a reasonable enhancement coefficient is selected to adjust the saturation of the image, so as to more accurately screen the image where the luminous flame first appears. Therefore, the ignition moment is judged according to the image brightness value, and the ignition moment of the excavate waste is determined.

Specifically, the time corresponding to when the luminous flame first appears in the image is determined as the ignition moment of the fuel.

In a specific embodiment, a diameter of the excavate waste particles 6 is not limited and can be determined based on specific experimental conditions; a diameter of the high temperature resistant corundum tube should match that of the K-type thermocouple and can be adjusted appropriately, and the entire system has good compatibility.

In a specific embodiment, the height of the slide rail bracket can be adjusted based on a distance from the furnace feeding port to the visualization window 7.

In the specific embodiment, the oxidant channel can freely change the combustion atmosphere, and the emission of CO₂ and NO_X of excavate waste can be reduced by adjusting the component contents of the oxidant, which is beneficial to promoting the efficient cleaning treatment of fuel.

The present invention discloses an optical diagnosis system and method for ignition of single-particle excavate waste, which achieves optical diagnosis and measurement of ignition of single-particle excavate waste, improves the stability of fuel conveying, solves the problem that excavate waste hoisted in the combustion process falls off due to thermal expansion, and reduces the error rate of experiments.

The embodiments in the specification are all described in a progressive manner, and each embodiment focuses on differences from other embodiments, and portions that are the same and similar between the embodiments may be referred to each other. Since the apparatus disclosed in the embodiment corresponds to the method disclosed in the embodiment, the description is relatively simple, and reference may be made to the partial description of the method.

The above description of the disclosed embodiments enables those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the present invention. Thus, the present invention is not intended to be limited to these embodiments shown herein but is to be accorded the broadest scope consistent with the principles and novel features disclosed herein.