Deep coal rock disturbance destruction test device and method considering hydrothermal coupling effect

Abstract

A deep coal rock disturbance destruction test device considering a hydrothermal coupling effect is characterized by comprising a loading system, a temperature control system, a humidity control system and a multi-physical-quantity monitoring system, and the device can effectively control the temperature and the humidity in the coal rock destruction process, so that the reliability of the device is improved. The occurrence state of deep coal rock in the coal mining process can be truly reflected, and multi-parameter response characteristics in disturbance damage of the deep coal rock can be analyzed; the device is simple in structure, convenient to operate and good in safety. The test method comprehensively considers the influence of water, heat and mining disturbance on coal rock damage characteristics, thereby providing a theoretical basis for early warning and prevention of deep coal rock dynamic disasters.

Description

Technical Field

[0001] The invention relates to the field of coal rock mechanics testing, and in particular to a deep coal rock disturbance destruction testing device and method considering the water-heat coupling effect. Background Art

[0002] The status of coal as the main energy source in my country is difficult to change in the short term. Only by giving full play to the bottom-line role of coal safety supply can we meet the major practical needs of national energy security. In recent years, with the exhaustion of shallow coal resources, coal mines have entered the deep mining stage one after another; deep mining faces a complex environment of high ground stress, high ground temperature, high karst water pressure and strong mining disturbance, which can easily induce coal rock dynamic disasters, causing serious damage and casualties. Therefore, coal rock dynamic disasters have become a bottleneck restricting the safe and efficient production of coal mines. Unlike shallow mining, deep mining will inevitably encounter the problem of gradually increasing ground temperature with increasing depth; at the same time, the deep surrounding rock will also be affected by groundwater and mining disturbance. Therefore, considering the influence of water, heat and mining disturbance on coal and rock cannot be ignored when studying the problem of deep coal rock dynamic disasters.

[0003] Deep coal and rock have been in a complex hydrothermal environment for a long time, and are affected by mining disturbances during the mining process, causing local coal and rock to be damaged, resulting in overall instability of the coal and rock structure. Research on the effects of water and heat on the physical and mechanical properties of coal and rock materials has attracted extensive attention from scholars at home and abroad, but previous studies have mostly considered the influence of a single factor in hydrothermal, and the temperature is as high as hundreds of degrees Celsius; it is unable to truly reflect the occurrence state of deep coal and rock during coal mining, and in actual mining, deep coal and rock will be disturbed by roof breakage, blasting, etc. Most previous test devices cannot comprehensively consider the disturbance and destruction characteristics of deep coal and rock under hydrothermal coupling. Summary of the invention

[0004] In view of the deficiencies of the above-mentioned prior art, the present invention aims to provide a device and method for testing deep coal and rock disturbance and destruction under the action of water-heat coupling. The device and method can comprehensively consider the influence of water, heat and mining disturbance on the destruction characteristics of coal and rock, thereby providing a theoretical basis for early warning and prevention of deep coal and rock dynamic disasters.

[0005] To achieve the above-mentioned purpose, the present invention provides a deep coal-rock disturbance damage test device considering the water-heat coupling effect, including a loading system, a temperature control system, a humidity control system and a multi-physical quantity monitoring system, wherein:

[0006] The loading system includes a static load / disturbance system, a pressure head and a constant temperature and humidity protection cover. The pressure head serves to fix and connect the static load / disturbance system and the sample, and the constant temperature and humidity protection cover serves to isolate the temperature and humidity exchange with the external environment.

[0007] Preferably, both static load and disturbance load are loaded by MTS e45305 electronic universal testing machine. Two loading modes, stress and displacement, can be selected during the test, and different disturbance frequencies and amplitudes can be set for the disturbance load.

[0008] The temperature control system includes a temperature sensor, a temperature controller, a temperature actuator and a temperature display: the temperature sensor uses a thermistor; the temperature controller is mainly used to receive the temperature signal sent by the sensor and compare it with the preset temperature value. According to the comparison result, the controller will issue corresponding instructions to adjust the working state of the heater or refrigerator to achieve precise temperature control; the temperature actuator uses a heater and a refrigerator to perform heating or cooling operations; the temperature display is connected to the temperature controller through a wire.

[0009] The humidity control system includes a humidity sensor, a humidity controller, a humidity actuator and a humidity display: the humidity sensor adopts a resistive humidity sensor; the humidity controller is mainly used to receive the signal sent by the humidity sensor and compare it with the preset humidity value. According to the comparison result, the controller will issue corresponding instructions to adjust the working state of the humidifier or dehumidifier to maintain the stability of the humidity; the humidity actuator adopts a humidifier and a dehumidifier to perform humidification or dehumidification operations; the humidity display is connected to the humidity controller through wires.

[0010] The multi-physical quantity monitoring system includes an acoustic emission monitoring system, a strain monitoring system, a high-speed camera system, and a thermal infrared monitoring system: the acoustic emission monitoring system includes an acoustic emission sensor, an amplifier, and an acoustic emission host, and the acoustic emission sensor and the amplifier, and the amplifier and the acoustic emission host are connected by wires; the strain monitoring system includes a strain gauge and a strain collector, and the strain gauge and the strain collector are connected by wires; the high-speed camera system includes a high-speed camera and a high-speed photo storage, and the high-speed camera and the high-speed photo storage are connected by wires; the thermal infrared monitoring system includes a thermal infrared camera and an infrared photo storage, and the thermal infrared camera and the infrared photo storage are connected by wires.

[0011] On the other hand, the present invention also provides a method for testing the disturbance damage of deep coal and rock under the effect of water-heat coupling. The test method uses the above-mentioned device provided by the present invention to study the influence of temperature and humidity on the damage characteristics of deep coal and rock, and comprises the following steps:

[0012] S1. Design and process specimens;

[0013] S11. According to the method recommended by the International Society of Rock Mechanics, process no less than 48 groups of 50mm×50mm×50mm cubic specimens;

[0014] S12. Divide the samples into four groups, 12 in each group, and number them according to the following rules: Cu-0 / 3 / 5 / 7-25 / 50 / 75 / 100-1 / 2 / 3, where 0 / 3 / 5 / 7 represent drying, saturation with water for 3 days, 5 days, and 7 days, respectively; 25 / 50 / 75 / 100 represent room temperature, and heat treatment temperature is 50, 75, and 100°C, respectively; 1 / 2 / 3 represents the sample number in this group, such as: Cu-3-75-2 represents the second sample in the sample saturated with water for 3 days and heat treated at 75°C;

[0015] S2, sample drying and saturation treatment;

[0016] S21. Place the dried samples in an electric blast drying oven for 24 hours according to the number, and the remaining three groups are saturated with water for 3, 5 and 7 days respectively;

[0017] S3. Conduct deep coal-rock disturbance and destruction tests under water-heat coupling;

[0018] S31, selecting one of the above-mentioned dry and saturated samples, and arranging an acoustic emission sensor, a strain gauge, a high-speed camera and a thermal infrared camera in a certain layout;

[0019] S32. Then, according to the numbering rules, the temperature of the coal sample is controlled by using a temperature control system, and the temperature is heated from room temperature to the design temperature at a heating rate of 5°C / min, and the temperature in the constant temperature and humidity protective cover is kept constant;

[0020] S33. Simultaneously, a humidity control system is used to control the humidity of the sample, the humidity environment is set to 40%, and the humidity in the constant temperature and humidity protective cover is kept constant;

[0021] S34. After maintaining constant temperature and humidity for 2 hours, first use displacement loading to load the sample to 60% of the uniaxial compressive strength, and set the loading rate to 0.20 mm / min; then hold the load for 20 seconds; then use sinusoidal loading until the sample is destroyed, and the amplitude and frequency are set to 30% and 1 Hz of the uniaxial compressive strength respectively;

[0022] S34. Synchronously capture the deformation and failure characteristics of the coal body through the acoustic emission monitoring system, strain monitoring system, high-speed camera system, and thermal infrared monitoring system;

[0023] S35, storing relevant data after the sample is destroyed;

[0024] S36, take out the damaged sample to carry out the next set of experiments, and repeat the test steps S31-S35;

[0025] S37. After the experiment is completed, the disturbance deformation, damage and multi-parameter response characteristics of deep coal and rock under the action of hydrothermal coupling are analyzed, and then the relationship between the disturbance deformation, damage and multi-parameter response characteristics of coal samples and the hydrothermal coupling is analyzed.

[0026] The beneficial effects of the present invention are as follows: the present invention provides a deep coal rock disturbance damage test device and method considering the water-heat coupling effect, the device can effectively control the temperature and humidity in the coal rock damage process, can truly reflect the occurrence state of deep coal rock in the coal mining process, and can analyze the multi-parameter response characteristics in the deep coal rock disturbance damage; the device has a simple structure, convenient operation and good safety. The test method comprehensively considers the influence of water, heat and mining disturbance on the coal rock damage characteristics, thereby providing a theoretical basis for early warning and prevention of deep coal rock dynamic disasters. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a schematic diagram of the test device of the present invention;

[0028] Figure 2 This is the loading path of the disturbance damage test mentioned in the present invention;

[0029] Figure 3 The present invention relates to the layout of acoustic emission sensors and strain gauges;

[0030] The descriptions of the various numbers in the figure are as follows:

[0031] 1- sample, 2- static load / disturbance system, 3- pressure head, 4- constant temperature and humidity protective cover, 5- temperature sensor, 6- temperature controller, 7- temperature actuator, 8- heater, 9- refrigerator, 10- temperature display, 11- humidity sensor, 12- humidity controller, 13- humidity actuator, 14- humidifier, 15- dehumidifier, 16- humidity display, 17- acoustic emission sensor, 18- amplifier, 19- acoustic emission host, 20- strain gauge, 21- strain collector, 22- high-speed camera, 23- high-speed photo storage, 24- thermal infrared camera, 25- infrared photo storage. DETAILED DESCRIPTION

[0032] The following describes several preferred embodiments of the present invention with reference to the drawings in the specification, so that the technical content is clearer and easier to understand. The present invention can be embodied in many different forms of embodiments, and the protection scope of the present invention is not limited to the embodiments mentioned in the text.

[0033] In the drawings, components with the same structure are indicated by the same numerical reference numerals, and components with similar structures or functions are indicated by similar numerical reference numerals. The size and thickness of each component shown in the drawings are arbitrarily shown, and the present invention does not limit the size and thickness of each component. In order to make the illustration clearer, the thickness of the components is appropriately exaggerated in some places in the drawings.

[0034] Combination Figure 1 and Figure 3 , assemble the test device described in the present invention, and the specific component composition and connection method of each system are as follows:

[0035] The loading system includes a static load / disturbance system 2 and a pressure head 3, and is built into a constant temperature and humidity protective cover 4;

[0036] The static load and disturbance load involved in the working process of the static load / disturbance system 2 are loaded by MTS e45305 electronic universal testing machine. Two loading modes, stress and displacement, can be selected during the test. The disturbance load can be set with different disturbance frequencies and amplitudes.

[0037] The temperature control system includes a temperature sensor 5, a temperature controller 6, a temperature actuator 7 and a temperature display 10: the temperature sensor 6 is made of a thermistor; the temperature controller 6 is mainly used to receive the temperature signal sent by the sensor and compare it with a preset temperature value. According to the comparison result, the temperature controller 6 will issue corresponding instructions to adjust the working state of the heater 8 or the refrigerator 9 to achieve precise temperature control; the temperature actuator 7 includes a heater 8 and a refrigerator 9 to perform heating or cooling operations; the temperature display 10 is connected to the temperature controller 6 through a wire.

[0038] The humidity control system includes a humidity sensor 11, a humidity controller 12, a humidity actuator 13 and a humidity display 16: the humidity sensor 11 is made of a resistive humidity sensor; the humidity controller 12 is mainly used to receive the signal sent by the humidity sensor and compare it with the preset humidity value. According to the comparison result, the humidity controller 12 will issue corresponding instructions to adjust the working state of the humidifier or dehumidifier to maintain the stability of the humidity; the humidity actuator 13 includes a humidifier 14 and a dehumidifier 15 to perform humidification or dehumidification operations; the humidity display 16 is connected to the humidity controller 12 through a wire.

[0039] The multi-physical quantity monitoring system includes an acoustic emission monitoring system, a strain monitoring system, a high-speed camera system, and a thermal infrared monitoring system: the acoustic emission monitoring system includes an acoustic emission sensor 17, an amplifier 18, and an acoustic emission host 19, and the acoustic emission sensor 17, the amplifier 18, and the acoustic emission host 19 are all connected by wires; the strain monitoring system includes a strain gauge 20 and a strain collector 21, and the strain gauge 20 and the strain collector 21 are connected by wires; the high-speed camera system includes a high-speed camera 22 and a high-speed photo storage 23, and the two are connected by wires; the thermal infrared monitoring system includes a thermal infrared camera 24 and an infrared photo storage 25, and the two are connected by wires.

[0040] The present invention also provides a method for testing deep coal-rock disturbance damage under the effect of water-heat coupling, and the sample preparation method uses the test device provided by the present invention. Figure 2 The sample preparation method provided in this embodiment comprises the following steps:

[0041] S1, design and process specimen 1;

[0042] S11. According to the method recommended by the International Society of Rock Mechanics, process no less than 48 groups of 50mm×50mm×50mm cubic specimens;

[0043] S12, divide the sample 1 into four groups, each with 12 pieces, and number them according to the following rules: Cu-0 / 3 / 5 / 7-25 / 50 / 75 / 100-1 / 2 / 3, where 0 / 3 / 5 / 7 represent drying, saturation with water for 3 days, 5 days, and 7 days, respectively; 25 / 50 / 75 / 100 represent room temperature, and heat treatment temperature is 50, 75, and 100°C, respectively; 1 / 2 / 3 represents the numbering of the sample 1 in the group, such as: Cu-3-75-2 represents the second sample 1 in the sample saturated with water for 3 days and heat treated at 75°C;

[0044] S2, drying and saturation treatment of sample 1;

[0045] S21. Drying sample 1 of the drying group was placed in an electric hot air drying oven for 24 hours according to the number, and the remaining three groups were saturated with water for 3, 5 and 7 days respectively;

[0046] S3. Conduct deep coal-rock disturbance and destruction tests under water-heat coupling;

[0047] S31, select a piece from the above-mentioned dried and saturated water treated sample 1, according to Figure 2 The acoustic emission sensor 17 and the strain gauge 20 are arranged in the layout method, and combined with Figure 1 Arrange a high-speed camera 22 and a thermal infrared camera 24;

[0048] S32, then, according to the numbering rule, the temperature of the sample 1 is controlled by using a temperature control system, and the sample is heated from room temperature to the design temperature at a heating rate of 5°C / min, and the temperature in the constant temperature and humidity protective cover 4 is kept constant;

[0049] S33, simultaneously, the humidity of the sample 1 is controlled by using a humidity control system, the humidity environment is set to 40%, and the humidity in the constant temperature and humidity protective cover 4 is kept constant;

[0050] S34, after maintaining constant temperature and humidity for 2 hours, first use displacement loading to load to 60% of the uniaxial compressive strength of sample 1, and the loading rate is set to 0.20mm / min; then hold the load for 20s; then use sinusoidal loading until sample 1 is destroyed, and the amplitude and frequency are set to 30% and 1Hz of the uniaxial compressive strength respectively;

[0051] S34. Synchronously capture the deformation and failure characteristics of the coal body through the acoustic emission monitoring system, strain monitoring system, high-speed camera system, and thermal infrared monitoring system;

[0052] S35, after the sample 1 is destroyed, the relevant data is stored;

[0053] S36, take out the damaged sample to carry out the next set of experiments, and repeat the test steps S31-S35;

[0054] S37. After the experiment is completed, the disturbance deformation, damage and multi-parameter response characteristics of deep coal and rock under the action of hydrothermal coupling are analyzed, and then the relationship between the disturbance deformation, damage and multi-parameter response characteristics of coal samples and the hydrothermal coupling is analyzed.

[0055] It should be noted that the above description is only a preferred embodiment of the present invention and is not intended to limit the scope of the present invention. It should be noted that any equivalent replacement and obvious deformation made by any person skilled in the art under the guidance of this specification are within the substantive scope of this specification and should be protected by the present invention.

Claims

1. A deep coal-rock disturbance damage test device considering the water-heat coupling effect, characterized in that: It includes loading system, temperature control system, humidity control system and multi-physical quantity monitoring system, among which: The loading system includes a static load / disturbance system, a pressure head and a constant temperature and humidity protection cover. The pressure head serves to fix and connect the static load / disturbance system and the sample, and the constant temperature and humidity protection cover serves to isolate the temperature and humidity exchange with the external environment. The temperature control system includes a temperature sensor, a temperature controller, a temperature actuator and a temperature display: the temperature sensor adopts a thermistor; the temperature controller is mainly used to receive the temperature signal sent by the sensor and compare it with the preset temperature value. According to the comparison result, the controller will issue a corresponding instruction to adjust the working state of the heater or refrigerator to achieve accurate temperature control; the temperature actuator adopts a heater and a refrigerator to perform heating or cooling operations; the temperature display is connected to the temperature controller through a wire; The humidity control system includes a humidity sensor, a humidity controller, a humidity actuator and a humidity display: the humidity sensor adopts a resistive humidity sensor; the humidity controller is mainly used to receive the signal sent by the humidity sensor and compare it with the preset humidity value. According to the comparison result, the controller will issue a corresponding instruction to adjust the working state of the humidifier or dehumidifier to maintain the stability of the humidity; the humidity actuator adopts a humidifier and a dehumidifier to perform humidification or dehumidification operations; the humidity display is connected to the humidity controller through a wire; The multi-physical quantity monitoring system includes an acoustic emission monitoring system, a strain monitoring system, a high-speed camera system, and a thermal infrared monitoring system: the acoustic emission monitoring system includes an acoustic emission sensor, an amplifier, and an acoustic emission host, and the acoustic emission sensor and the amplifier, and the amplifier and the acoustic emission host are connected through wires; the strain monitoring system includes a strain gauge and a strain collector, and the strain gauge and the strain collector are connected through wires; the high-speed camera system includes a high-speed camera and a high-speed photo storage, and the high-speed camera and the high-speed photo storage are connected through wires; the thermal infrared monitoring system includes a thermal infrared camera and an infrared photo storage, and the thermal infrared camera and the infrared photo storage are connected through wires.

2. The test device according to claim 1, characterized in that: The static load and disturbance load involved in the working process of the static load / disturbance system are loaded by using MTSe45305 electronic universal testing machine. Two loading modes, stress and displacement, can be selected during the test, and the disturbance load can be set with different disturbance frequencies and amplitudes.

3. A method for testing the disturbance and destruction of deep coal and rock under the effect of water-heat coupling, characterized in that: The test method uses the sample device according to any one of claims 1 to 2, and the test method comprises the following steps: S1. Design and process specimens; S11. According to the method recommended by the International Society of Rock Mechanics, process no less than 48 groups of 50mm×50mm×50mm cubic specimens; S12. Divide the samples into four groups, 12 in each group, and number them according to the following rules: Cu-0 / 3 / 5 / 7-25 / 50 / 75 / 100-1 / 2 / 3, where 0 / 3 / 5 / 7 represent drying, saturation with water for 3 days, 5 days, and 7 days, respectively; 25 / 50 / 75 / 100 represent room temperature, and heat treatment temperature is 50, 75, and 100°C, respectively; 1 / 2 / 3 represents the sample number in this group, such as: Cu-3-75-2 represents the second sample in the sample saturated with water for 3 days and heat treated at 75°C; S2, sample drying and saturation treatment; S21. Place the dried samples in an electric blast drying oven for 24 hours according to the number, and the remaining three groups are saturated with water for 3, 5 and 7 days respectively; S3. Conduct deep coal-rock disturbance and destruction tests under water-heat coupling; S31, selecting one of the above-mentioned dry and saturated samples, and arranging an acoustic emission sensor, a strain gauge, a high-speed camera and a thermal infrared camera in a certain layout; S32. Then, according to the numbering rules, the temperature of the coal sample is controlled by using a temperature control system, and the temperature is heated from room temperature to the design temperature at a heating rate of 5°C / min, and the temperature in the constant temperature and humidity protective cover is kept constant; S33. Simultaneously, a humidity control system is used to control the humidity of the sample, the humidity environment is set to 40%, and the humidity in the constant temperature and humidity protective cover is kept constant; S34. After maintaining constant temperature and humidity for 2 hours, first use displacement loading to load the sample to 60% of the uniaxial compressive strength, and set the loading rate to 0.20 mm / min; then hold the load for 20 seconds; then use sinusoidal loading until the sample is destroyed, and the amplitude and frequency are set to 30% and 1 Hz of the uniaxial compressive strength respectively; S34. Synchronously capture the deformation and failure characteristics of the coal body through the acoustic emission monitoring system, strain monitoring system, high-speed camera system, and thermal infrared monitoring system; S35, after the sample is destroyed, storing relevant data; S36, take out the damaged sample to carry out the next set of experiments, and repeat the test steps S31-S35; S37. After the experiment is completed, the disturbance deformation, damage and multi-parameter response characteristics of deep coal and rock under the action of hydrothermal coupling are analyzed, and then the relationship between the disturbance deformation, damage and multi-parameter response characteristics of coal samples and the hydrothermal coupling is analyzed.

Images