阅读说明：本技术 一种热重-光谱检测系统及使用方法 (Thermogravimetric-spectral detection system and use method thereof ) 是由 司梦婷 程强 罗自学 袁林 李密 陈伟 于 2021-09-09 设计创作，主要内容包括：本发明涉及热重光谱检测技术领域,公开了一种热重-光谱检测系统,包括热重分析模块和用于拍摄样品的燃烧图像成像模块,热重分析模块包括称重单元和燃烧单元,称重单元连接有吊具的一端,吊具的另一端连接有吊篮,吊篮用于盛放样品,吊篮正下方对应设置有燃烧单元；此外,本发明还公开了一种基于热重-光谱检测系统的使用方法。本发明可同步获得单颗粒煤在整个燃烧过程中的质量变化以及颗粒的燃烧图像,可对单颗粒煤的反应动力学进行分析,并得到燃烧过程中单颗粒煤的燃烧温度和辐射特性参数演变。(The invention relates to the technical field of thermogravimetric spectrum detection, and discloses a thermogravimetric-spectroscopic detection system, which comprises a thermogravimetric analysis module and a combustion image imaging module for shooting a sample, wherein the thermogravimetric analysis module comprises a weighing unit and a combustion unit, the weighing unit is connected with one end of a lifting appliance, the other end of the lifting appliance is connected with a hanging basket, the hanging basket is used for containing the sample, and the combustion unit is correspondingly arranged right below the hanging basket; in addition, the invention also discloses a use method of the thermogravimetric-spectral detection system. The method can synchronously obtain the quality change of the single-particle coal in the whole combustion process and the combustion image of the particles, can analyze the reaction kinetics of the single-particle coal, and obtains the combustion temperature and radiation characteristic parameter evolution of the single-particle coal in the combustion process.)

1. A thermogravimetric-spectroscopic detection system comprising a thermogravimetric analysis module and an imaging module (5);

the thermogravimetric analysis module comprises a weighing unit (1) and a combustion unit (2), the weighing unit (1) is connected with one end of a lifting appliance (3), the other end of the lifting appliance (3) is connected with a hanging basket (4), the hanging basket (4) is used for containing a sample (7), and the combustion unit (2) is correspondingly arranged right below the hanging basket (4);

the imaging module (5) is used for shooting a combustion image of the sample (7).

2. The thermogravimetric-spectroscopic detection system according to claim 1, characterized in that a heat-insulating layer (6) is arranged below the weighing unit (1), the heat-insulating layer (6) is provided with a through hole, and the other end of the hanger (3) is connected with the basket (4) through the through hole.

3. The thermogravimetric-spectroscopic detection system of claim 1, characterized in that said weighing unit (1) is able to continuously measure the weight of said sample (7), said imaging module (5) being able to continuously take images of the combustion of said sample (7).

4. The thermogravimetric-spectral detection system of claim 3, wherein each of said combustion images comprises a plurality of spectral radiation images having a corresponding plurality of radiation wavelengths.

5. The thermogravimetric-spectroscopic detection system according to claim 1, characterized in that said combustion unit (2) comprises a burner (8) and a fuel gas cylinder (9), said burner (8) being in communication with said fuel gas cylinder (9) through a conduit (10), said conduit (10) being provided with a two-way valve (11) and a pressure regulating valve (12).

6. The thermogravimetric-spectroscopic detection system of claim 5, characterized in that said fuel gas cylinder (9) is a methane cylinder.

7. The thermogravimetric-spectroscopic detection system according to any one of claims 1 to 6, characterized in that the weighing unit (1) is a thermogravimetric balance, the burner (8) is a flat flame burner, the spreader (3) is a boom or a sling, and the imaging module (5) is a hyperspectral imaging device.

8. Use of the thermogravimetric-spectroscopic detection system according to any one of claims 1 to 7, characterized in that it comprises the following steps:

starting the weighing unit (1) and resetting;

making the sample (7) and placing the sample (7) on the upper surface of the basket (4);

triggering the weighing unit (1) and the imaging module (5), wherein the weighing unit (1) monitors and records the weight change of the sample (7), and the imaging module (5) shoots and records a combustion image of the sample (7);

igniting the combustion gas in the combustion unit (2) to drive the sample (7) to burn;

collecting data, collecting the record of the mass change of the sample (7) and the combustion image of the sample (7);

and (6) analyzing the data.

9. Use of the thermogravimetric-spectroscopic detection system according to claim 8, characterized in that the recording frequency of the weighing cell (1) and the shooting frequency of the imaging module (5) are both 1s^-1。

10. Use of the thermogravimetric-spectroscopic detection system according to claim 8, characterized in that said sample (7) is two single particles of coal having a diameter of 8mm-10 mm.

Technical Field

The invention relates to the technical field of thermogravimetric-spectroscopic detection, in particular to a thermogravimetric-spectroscopic detection system and a use method thereof.

Background

Coal resources in China are rich in reserves and low in price, and are always one of main energy sources, coal mainly provides energy sources through combustion, and coal still plays an important role in energy consumption in the future.

At present, the combustion characteristics of coal are not directly detected, coal quality parameters of the coal are directly obtained through industrial analysis element analysis, and calculation and prediction are carried out according to an empirical formula, so that the accuracy is not high. The main reason is that the combustion characteristics of coal are closely related to the chemical structure of coal, and the research on the combustion characteristics of coal through element analysis parameters has certain one-sidedness.

At the present stage, in order to research the combustion characteristics of coal, mathematical modeling can be performed on the combustion condition of industrial coal, which is often performed on the basis of knowledge of a combustion mechanism and a model, and further experimental research needs to be performed on the combustion behavior of single-particle coal.

The combustion behaviour of single-particle coal is mainly dependent on the reaction kinetics, photographic observations of the characteristic combustion phenomena (ignition, devolatilization, expansion, oxidation and burnout, etc.), and the evolution of the combustion temperature and radiation parameters. Through researching the combustion behavior of single-particle coal, a combustion mechanism can be explored, and a combustion model can be established, so that the method is effectively used for guiding the improvement and optimization design of the coal combustion technology in industrial production.

Therefore, in order to further understand the coal combustion characteristics, a device for photographing and observing based on a single combustion behavior and further understanding the evolution of the combustion temperature and the radiation parameters needs to be designed.

Disclosure of Invention

The invention aims to provide a thermogravimetric-spectroscopic detection system and a using method thereof, which are used for researching the combustion behavior of single-particle coal.

In order to achieve the purpose, the invention provides the following scheme: the invention provides a thermogravimetric-spectroscopic detection system, which comprises a thermogravimetric analysis module and an imaging module;

the thermogravimetric analysis module comprises a weighing unit and a combustion unit, the weighing unit is connected with one end of a lifting appliance, the other end of the lifting appliance is connected with a hanging basket, the hanging basket is used for containing samples, and the combustion unit is correspondingly arranged right below the hanging basket;

the imaging module is used for shooting a combustion image of the sample.

Further, a heat insulation layer is arranged below the weighing unit and provided with a through hole, and the other end of the lifting appliance penetrates through the through hole and is connected with the hanging basket.

Further, the weighing unit can continuously measure the weight of the sample, and the imaging module can continuously take combustion images of the sample.

Further, each of the combustion images comprises a plurality of spectral radiation images corresponding to a plurality of radiation wavelengths.

Further, the combustion unit comprises a combustor and a fuel gas storage cylinder, the combustor is communicated with the fuel gas storage cylinder through a pipeline, and a two-way valve and a pressure regulating valve are arranged on the pipeline.

Further, the fuel gas cylinder is a methane cylinder.

Further, the weighing unit is a thermogravimetric balance, the combustion unit is a flat flame combustor, the lifting appliance is a lifting rod or a lifting rope, and the imaging module is a hyperspectral imaging device.

The invention discloses the following technical effects:

the invention combines thermogravimetric analysis and hyperspectral imaging to research the combustion behavior of single-particle coal. By using the system of the invention, the quality change of single-particle coal in the whole combustion process and the combustion image of particles can be synchronously obtained. From the obtained mass change, we can analyze the reaction kinetics of single-particle coal; the combustion picture obtained by shooting from the image system can not only observe the typical combustion phenomenon, the flame shape and the particle combustion state of the single-particle coal, but also further obtain the combustion temperature and radiation characteristic parameter evolution of the single-particle coal in the combustion process.

The invention also provides a use method based on the thermogravimetric-spectroscopic detection system, which comprises the following steps:

starting the weighing unit and resetting;

making the sample and placing the sample on the upper surface of the basket;

triggering the weighing unit and the imaging module, wherein the weighing unit monitors and records the weight change of the sample, and the imaging module shoots and records a combustion image of the sample;

igniting a combustion gas in the combustion unit to drive the sample to burn;

collecting data, namely collecting the mass change record of the sample and a combustion image of the sample;

and (6) analyzing the data.

Further, the recording frequency of the weighing unit and the shooting frequency of the imaging module are both 1s^-1。

Further, the sample is two single-particle coals, and the diameter of the single-particle coal is 8mm-10 mm.

The advantages of the thermogravimetric-spectroscopic detection system and the use method thereof over the prior art are the same, and are not repeated herein.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings needed to be used in the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings without inventive exercise.

FIG. 1 is a schematic diagram of a thermogravimetric-spectroscopic detection system according to the present invention;

FIG. 2 is a schematic view of the structure of the combustion unit of the present invention;

FIG. 3 is a graph of weight loss curve and simultaneous combustion image for single particle coal;

FIG. 4 is a photograph of the combustion of a single particle of coal at 20 typical combustion times;

FIG. 5 is a radiation intensity image of single particle coal at a radiation intensity of 852 nm;

reference numerals: 1. a weighing unit; 2. a combustion unit; 3. a spreader; 4. a hanging basket; 5. an imaging module; 6. a heat-insulating layer; 7. a sample; 8. a burner; 9. a fuel gas cylinder; 10. a pipeline; 11. a two-way valve; 12. a pressure regulating valve.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

In order to make the aforementioned objects, features and advantages of the present invention comprehensible, embodiments accompanied with figures are described in further detail below.

Referring to fig. 1, the present invention provides a thermogravimetric-spectroscopic detection system, which is composed of a thermogravimetric analysis module and an imaging module 5.

The thermogravimetric analysis module comprises a weighing unit 1 and a combustion unit 2, the weighing unit adopts a thermogravimetric balance, the thermogravimetric balance is flatly placed on the support frame for realizing the automatic and continuous collection of the weight in the combustion process of a sample 7, a heat preservation layer 6 of 10cm is installed below the thermogravimetric balance, a central through hole is formed in the heat preservation layer 6, the heat preservation layer 6 is arranged for preventing the thermal disturbance generated in the combustion process from influencing the measurement of the thermogravimetric balance, the lower end of the thermogravimetric balance is provided with a lifting appliance 3, the weighing end of the balance is connected with one end of the lifting appliance 3, the other end of the lifting appliance 3 penetrates through the central through hole in the heat preservation layer 6 to be connected with a hanging basket 4, the hanging basket 4 is arranged at the height position of 10cm right above the combustion unit 2, the sample 7 is placed in the hanging basket 4, and the combustion unit 2 is ignited.

The imaging module 5 is a hyperspectral imaging device, is placed 35cm away from the combustor 8 in the horizontal direction, and the hyperspectral imaging device and the sample 7 are at the same horizontal height and are used for synchronously recording the combustion condition of the sample 7.

On one hand, the thermogravimetric-spectroscopic detection system can record the mass change of the sample 7 in the combustion process through the thermogravimetric analysis system, and on the other hand, an image detection module of the thermogravimetric-spectroscopic detection system can synchronously record the combustion image of the sample 7.

Preferably, referring to fig. 2, the combustion unit 2 further includes a burner 8 and a fuel gas cylinder 9, the fuel gas cylinder is communicated with the fuel gas cylinder 9 through a pipe 10, the fuel gas cylinder 9 stores methane gas, the fuel gas cylinder 9 is a methane gas cylinder, the pipe 10 is provided with a two-way valve 11 and a pressure regulating valve 12, the two-way valve 11 is used for regulating the opening and closing of gas, and the pressure regulating valve 12 can regulate the pressure of combustion gas to be constant.

It is worth to say that the thermogravimetric balance is ML204T/02(Mettler-Toledo) type thermogravimetric balance, the weighing range is 0.16 g-220 g (+ -0.1 mg), and the minimum reading interval is 0.01 second respectively; the lifting appliance 3 can be a lifting rod or a lifting rope; the hanging basket 4 is a wire mesh; the combustor adopts a McKenna combustor; an imaging device of the thermogravimetric-spectral detection system is an MQ022HG-IM-SM5X5-NIR type hyperspectral imaging device, the minimum exposure time of the imaging device is 72 mu s, the spectral resolution is 600 nm-975 nm, the spatial resolution is 409 (horizontal) X217 (vertical) pixels, one image shot by the imaging device comprises 25 spectral radiation images, wherein the 25 spectral radiation images correspond to 25 radiation wavelengths.

The experimental process is as follows: starting a thermal gravimetric balance and resetting; two single-particle coals with the diameter of about 8-10 mm are made as samples 7, and the single-particle coals are placed in the center of the hanging basket 4; triggering the thermogravimetric balance and the hyperspectral imaging equipment at the same time, so that the thermogravimetric balance starts to weigh continuously, and the hyperspectral imaging equipment continuously shoots combustion images of the sample 7; igniting methane combustion gas on the combustor to drive the single-particle coal to combust; the weight and spectral image data in the combustion process of the single-particle coal are respectively recorded by a thermogravimetric balance and a hyperspectral imaging device; and (6) analyzing the data.

Preferably, the recording frequency of the thermogravimetric balance is set to 1s^-1The shooting frequency of the hyperspectral imaging device is also set to 1s^-1。

And (3) data analysis process:

the mass of the single-particle coal is calculated after being weighed by a thermogravimetric balance, and the calculation is as follows:

wherein m is the mass of the single-particle coal, G is the weight of the single-particle coal weighed by the thermogravimetric balance, and G is the acceleration of gravity.

The normalized form of the weight loss of an individual coal sample 7, which can represent its degree of combustion, can be defined as:

where α is the normalized weight loss of a single coal sample 7, m_iIs the initial mass, m, of the individual coal particle sample 7_tIs the actual mass of the individual coal particle sample 7 at that time, m_fIs the final mass of the individual coal particle sample 7.

Further, by differentiating the normalized weight loss of a single coal particle sample 7 with respect to time, the combustion reaction rate of a single coal particle sample 7 can be obtained:

wherein r is the reaction rate and t is the reaction time. According to the above formula, the combustion dynamics of the individual coal particle sample 7 can be analyzed based on the results of mass change obtained by the balance.

Fig. 3 shows a weight loss-time curve and a synchronous combustion image of a single-particle coal obtained by a thermogravimetric-spectroscopic detection system.

On the other hand, the radiation intensity of a single combustion coal particle received by the hyperspectral imaging apparatus is calculated as follows:

I_λ＝ε_λI_bλ

wherein the content of the first and second substances,

here, I_λRepresenting the intensity of radiation, ε, of individual burning coal particles_λThe spectral emissivity of single-particle coal is shown; i is_bλIs the spectral black body radiation intensity; c₁Denotes a first radiation constant, C₁＝3.741832×108W·μm³/m²，C₂Denotes a second radiation constant, C₂Where, K is 1.4388 × 104 μm · K, λ denotes the radiation wavelength, and T denotes the temperature.

We divide the spectral radiation intensities at two wavelengths to yield:

based on the two-color method, the temperature of the single particle can be obtained:

where i denotes the ith wavelength of the hyperspectral imaging apparatus,is the intensity of the spectral radiation at the i-th wavelength detected by the device. By aligning T within a certain range_iThe average value is taken to obtain the combustion temperature of the pellets.

The spectral emissivity of single-particle coal is as follows:

further, we obtained the total spectral emissivity of single particle coal:

finally, the combustion temperature and radiation characteristic parameter evolution of the particles in the combustion process can be obtained.

To further analyze the particle combustion process, a picture of the combustion of a single particle of coal at 20 typical combustion times obtained by a thermogravimetric-spectroscopic detection system is shown in fig. 4.

The combustion picture taken by the spectral imaging device can be converted into 25 spectral radiation intensity images by calibration on a high-temperature black body furnace, and as shown in fig. 5, the radiation intensity image of a single particle converted from the combustion picture at 20 typical combustion moments with the radiation intensity of 852nm is obtained.

In the description of the present invention, it is to be understood that the terms "longitudinal", "lateral", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", and the like, indicate orientations or positional relationships based on those shown in the drawings, are merely for convenience of description of the present invention, and do not indicate or imply that the referenced devices or elements must have a particular orientation, be constructed and operated in a particular orientation, and thus, are not to be construed as limiting the present invention.

The above-described embodiments are merely illustrative of the preferred embodiments of the present invention, and do not limit the scope of the present invention, and various modifications and improvements of the technical solutions of the present invention can be made by those skilled in the art without departing from the spirit of the present invention, and the technical solutions of the present invention are within the scope of the present invention defined by the claims.