阅读说明：本技术 用红外成像技术测定炼焦煤成焦过程表面裂纹特性的方法 (Method for measuring surface crack characteristics of coking coal in coking process by using infrared imaging technology ) 是由 刘洋 白金锋 郭天赐 钟祥云 李超 张雅茹 于 2020-04-12 设计创作，主要内容包括：本发明涉及一种用红外成像技术测定炼焦煤成焦过程表面裂纹特性的方法,包括：(1)使用电阻炉升温对炼焦煤进行干馏,通过红外热成像仪对煤饼进行热成像,检测煤结焦过程中表面形态结构的变化过程,在不同结焦阶段观测焦炭的表面裂纹形态及其对应的温度范围；(2)将红外热成像仪测得的带有裂纹的焦炭表面形态结构图片,运用INSIDE IR软件分析系统通过网格划分的方式对不同炼焦煤在结焦过程中的裂纹尺寸面积进行计算,探讨炼焦煤裂纹面积及裂纹率与焦炭冷态强度的关系。本发明所述方法具有可视性强、量化性强的特点,裂纹尺寸从0.1mm～10mm均可以量化分析,分析结果对生产应用具有重要的实际指导意义。(The invention relates to a method for measuring surface crack characteristics of coking coal in a coking process by using an infrared imaging technology, which comprises the following steps: (1) the method comprises the following steps of (1) carrying out dry distillation on coking coal by using a resistance furnace to increase the temperature, carrying out thermal imaging on a coal cake by using an infrared thermal imager, detecting the change process of a surface morphological structure in the coal coking process, and observing the surface crack morphology of the coke and the corresponding temperature range thereof at different coking stages; (2) calculating the crack size area of different coking coals in the coking process by using an INSIDE IR software analysis system through a grid division mode according to the picture of the surface morphological structure of the coke with cracks measured by an infrared thermal imager, and discussing the relationship between the crack area and the crack rate of the coking coals and the cold-state strength of the coke. The method has the characteristics of strong visibility and high quantification performance, the crack size can be quantitatively analyzed from 0.1mm to 10mm, and the analysis result has important practical guiding significance for production and application.)

1. The method for measuring the surface crack characteristics of the coking coal in the coking process by using the infrared imaging technology is characterized by comprising the following steps of:

(1) the method comprises the following steps of (1) carrying out dry distillation on coking coal by using a resistance furnace to increase the temperature, carrying out thermal imaging on a coal cake by using an infrared thermal imager, detecting the change process of a surface morphological structure in the coal coking process, and observing the surface crack morphology of the coke and the corresponding temperature range thereof at different coking stages;

(2) calculating the crack size area of different coking coals in the coking process by using an INSIDE IR software analysis system through a grid division mode according to the picture of the surface morphological structure of the coke with cracks measured by an infrared thermal imager, and discussing the relationship between the crack area and the crack rate of the coking coals and the cold-state strength of the coke.

2. The method for determining the surface crack characteristics of coking coal in the coking process by using the infrared imaging technology as claimed in claim 1, wherein in the step (1), nitrogen with the purity of 99.99 percent is introduced into the coking chamber of the resistance furnace as protective gas, and the space velocity of the nitrogen in the resistance furnace is 10h^-1～20h^-1。

3. The method for determining the surface crack characteristics of the coking coal in the coking process by using the infrared imaging technology as claimed in claim 1, wherein in the step (1), after the temperature of the resistance furnace is raised to 300 ℃, the furnace cover is opened, and the coal cake is thermally imaged by an infrared thermal imaging instrument; the time interval for measuring the imaging pictures is 5 min-30 min, and the furnace cover is quickly covered after each photographing.

4. The method for determining the surface crack characteristics of the coking coal in the coking process by using the infrared imaging technology as claimed in claim 1, wherein the change process of the surface morphological structure in the coal coking process in the step (1) refers to the process of generating cracks by the softening melting of coal cakes and the shrinkage of semicoke.

5. The method for determining surface crack characteristics of coking coal in the coking process by using the infrared imaging technology as claimed in claim 1, wherein in the step (2), after the picture of the morphological structure of the surface of the coke with cracks, which is measured by the infrared thermal imager, is subjected to grid division, the area of the cracks in each grid is calculated, then the total area of the cracks of the coke cake is obtained, and the crack rate is calculated; and researching the relationship between the size and area of the crack formed in the coking process of the coal under different coalification degrees and the coking time and the relationship between the cracking rate of the coking coal and the cold strength of the coke according to the imaging pictures.

6. The method for determining the surface crack characteristics of coking coal in the coking process by using the infrared imaging technology as claimed in claim 1, wherein the parameters of the infrared thermal imaging instrument are satisfied as follows: wavelength range: 7.5-13 μm, temperature measuring range: -40 ℃ to 1000 ℃, measurement accuracy: . + -. 2 ℃ measurement reproducibility: ± 1 ℃, operating temperature: -15 ℃ to +50 ℃, humidity: 10 to 15 percent.

7. The method for determining the surface crack characteristics of the coking coal in the coking process by using the infrared imaging technology as claimed in claim 1, 2 or 3, wherein the electric resistance furnace is an external heating type cylindrical well type electric resistance furnace, and the inner diameter of a coking chamber of the electric resistance furnace is more than 130 mm.

8. The method for determining the surface crack characteristics of the coking coal in the coking process by using the infrared imaging technology as claimed in claim 1, wherein the particle size of the coking coal is 0-3 mm, and the coal particles with the particle size of 1-2 mm account for more than 80%.

Technical Field

The invention relates to the technical field of coke crack performance detection in the coal coking industry, in particular to a method for determining the surface crack characteristic of coking coal in a coking process by using an infrared imaging technology.

Background

Coke is an important raw material in the metallurgical industry, the function of which in blast furnaces is irreplaceable, and with the development of large blast furnaces, coke with larger particle size more suitable for large blast furnace application must be prepared, thereby placing higher measurement requirements on the coking technology and monitoring the crack formation affecting the change of the coke particle size during the coking process. The purposes of reducing the coking cost, saving high-quality coking coal resources and improving the coke quality are achieved by researching the change characteristic of the coke cracks in the coking process. The invention utilizes an infrared imager to carry out imaging and temperature characteristic research on the surface morphology of coking coal in the coking process, in particular to the process that softening, melting and semicoke shrinkage can occur to generate cracks in the coking process of the coking coal along with the rise of temperature in the heating process. The research of the coking process of the infrared radiation source in the coking process of the coking coal is not reported so far, and the process expresses that the crack formation in the coking process of the coking coal has the characteristics of intuition and good visualization.

Disclosure of Invention

The invention provides a method for determining the surface crack characteristics of coking coal in a coking process by using an infrared imaging technology, which has the characteristics of strong visibility and strong quantization when researching the change rule of coke cracks, the size of the cracks can be quantized from 0.1mm to 10mm, the change rule of the formed cracks along with the temperature is obvious, and the analysis result has important practical guiding significance for production and application.

In order to achieve the purpose, the invention adopts the following technical scheme:

the method for measuring the surface crack characteristics of the coking coal in the coking process by using the infrared imaging technology comprises the following steps:

(1) the method comprises the following steps of (1) carrying out dry distillation on coking coal by using a resistance furnace to increase the temperature, carrying out thermal imaging on a coal cake by using an infrared thermal imager, detecting the change process of a surface morphological structure in the coal coking process, and observing the surface crack morphology of the coke and the corresponding temperature range thereof at different coking stages;

(2) calculating the crack size area of different coking coals in the coking process by using an INSIDE IR software analysis system through a grid division mode according to the picture of the surface morphological structure of the coke with cracks measured by an infrared thermal imager, and discussing the relationship between the crack area and the crack rate of the coking coals and the cold-state strength of the coke.

In the step (1), nitrogen with the purity of 99.99 percent is introduced into a carbonization chamber of the resistance furnace as protective gas, and the space velocity of the nitrogen in the resistance furnace is 10h^-1～20h^-1。

In the step (1), after the temperature of the resistance furnace is raised to 300 ℃, opening a furnace cover, and carrying out thermal imaging on the briquette through an infrared thermal imaging instrument; the time interval for measuring the imaging pictures is 5 min-30 min, and the furnace cover is quickly covered after each photographing.

In the step (1), the change process of the surface morphological structure in the coal coking process refers to the process of the coal cake undergoing reflow and semicoke shrinkage causing cracks.

In the step (2), after grid division is carried out on the picture of the coke surface morphological structure with cracks, which is measured by an infrared thermal imager, the area of the cracks in each grid is calculated, then the total area of the coke cake cracks is obtained, and the crack rate is calculated; and researching the relationship between the size and area of the crack formed in the coking process of the coal under different coalification degrees and the coking time and the relationship between the cracking rate of the coking coal and the cold strength of the coke according to the imaging pictures.

The parameters of the infrared thermal imager should satisfy: wavelength range: 7.5-13 μm, temperature measuring range: -40 ℃ to 1000 ℃, measurement accuracy: . + -. 2 ℃ measurement reproducibility: ± 1 ℃, operating temperature: -15 ℃ to +50 ℃, humidity: 10 to 15 percent.

The resistance furnace is an external heating type cylindrical well type resistance furnace, and the inner diameter of a carbonization chamber of the resistance furnace is more than 130 mm.

The particle size of the coking coal is 0-3 mm, wherein the coal particles with the particle size of 1-2 mm account for more than 80%.

Compared with the prior art, the invention has the beneficial effects that:

(1) the invention provides a method for researching the temperature of coal cracks and the size of the cracks in the coking process of coking coal by using an infrared imaging technology, and the research method is visual and convenient;

(2) the method does not need a large-scale test coke oven, has simple experimental equipment, can meet the requirement of quick and variable laboratory research, and has high test efficiency;

(3) by controlling the heating rate of the resistance furnace and introducing protective atmosphere into the resistance furnace in the heating process to prevent the coal from being oxidized, the simulation of the heating process and the production of the coke oven can be ensured, and the analysis and the comparison are convenient;

(4) the cracks of the coal cake on the infrared imaging picture are clearly visible, the obtained picture is subjected to grid division, the length and the width of the cracks in each grid are measured, and the total length, the width and the area of the cracks are calculated, so that the represented crack index parameters can be formed; experiments prove that the width of the crack changes obviously along with the rise of the self heating temperature of the coal cake; the difference of the crack amount of the tamping coal with high coal material density and the top-loading coal with low coal material density and the temperature parameters of cracks generated by different coal blending schemes are different;

(5) the crack amount of each single coal is analyzed and compared with the cold strength of the coke, the influence of the crack on important indexes of the metallurgical coke in the coking process is researched, the quantitative analysis value on the thermal polycondensation characteristic in the coking process of the coking coal is important, and the theoretical and practical significance on mastering the crack formation rule in the coking process of the coking coal and guiding the coal blending coking production is important.

Drawings

Fig. 1-8 are thermal imaging diagrams of coal samples at different furnace temperatures in the embodiment of the invention.

FIG. 9 is a coal cake grid division diagram in an embodiment of the present invention.

Detailed Description

The invention relates to a method for measuring the surface crack characteristics of coking coal in a coking process by using an infrared imaging technology, which comprises the following steps:

(1) the method comprises the following steps of (1) carrying out dry distillation on coking coal by using a resistance furnace to increase the temperature, carrying out thermal imaging on a coal cake by using an infrared thermal imager, detecting the change process of a surface morphological structure in the coal coking process, and observing the surface crack morphology of the coke and the corresponding temperature range thereof at different coking stages;

(2) calculating the crack size area of different coking coals in the coking process by using an INSIDE IR software analysis system through a grid division mode according to the picture of the surface morphological structure of the coke with cracks measured by an infrared thermal imager, and discussing the relationship between the crack area and the crack rate of the coking coals and the cold-state strength of the coke.

In the step (1), nitrogen with the purity of 99.99 percent is introduced into a carbonization chamber of the resistance furnace as protective gas, and the space velocity of the nitrogen in the resistance furnace is 10h^-1～20h^-1。

In the step (1), after the temperature of the resistance furnace is raised to 300 ℃, opening a furnace cover, and carrying out thermal imaging on the briquette through an infrared thermal imaging instrument; the time interval for measuring the imaging pictures is 5 min-30 min, and the furnace cover is quickly covered after each photographing.

In the step (1), the change process of the surface morphological structure in the coal coking process refers to the process of the coal cake undergoing reflow and semicoke shrinkage causing cracks.

In the step (2), after grid division is carried out on the picture of the coke surface morphological structure with cracks, which is measured by an infrared thermal imager, the area of the cracks in each grid is calculated, then the total area of the coke cake cracks is obtained, and the crack rate is calculated; and researching the relationship between the size and area of the crack formed in the coking process of the coal under different coalification degrees and the coking time and the relationship between the cracking rate of the coking coal and the cold strength of the coke according to the imaging pictures.

The parameters of the infrared thermal imager should satisfy: wavelength range: 7.5-13 μm, temperature measuring range: -40 ℃ to 1000 ℃, measurement accuracy: . + -. 2 ℃ measurement reproducibility: ± 1 ℃, operating temperature: -15 ℃ to +50 ℃, humidity: 10 to 15 percent.

The resistance furnace is an external heating type cylindrical well type resistance furnace, and the inner diameter of a carbonization chamber of the resistance furnace is more than 130 mm.

The particle size of the coking coal is 0-3 mm (namely the particle size is not less than 0 and not more than 3mm), wherein the coal particles with the particle size of 1-2 mm (the particle size is not less than 1mm and not more than 2mm) account for more than 80%.

The following examples are carried out on the premise of the technical scheme of the invention, and detailed embodiments and specific operation processes are given, but the scope of the invention is not limited to the following examples. The methods used in the following examples are conventional methods unless otherwise specified.