阅读说明：本技术 油页岩高温热解时导热、膨胀与裂纹扩展的综合测试装置 (Comprehensive testing device for heat conduction, expansion and crack propagation in high-temperature pyrolysis of oil shale ) 是由 宋盛渊 张烁 郭威 张文 马文良 胡莹 于 2020-08-13 设计创作，主要内容包括：本发明公开一种油页岩高温热解时导热、膨胀与裂纹扩展的综合测试装置,包括实验系统、设置在实验系统内的加热系统、与实验系统连通的收集系统、与实验系统电性连接的控制及数据采集系统,本发明操作简单,高效,通过伺服压力机保持了岩体的垂直应力状态,能够在一次实验中系统地测定出在上覆地层自重压力作用下油页岩热解过程的线膨胀系数、油页岩的膨胀力及导热系数,提供了一种测定油页岩导热系数的新思路,该装置为可视化装置,克服了油页岩因热解,裂纹发展无规律、难以测定的难题。(The invention discloses a comprehensive testing device for heat conduction, expansion and crack propagation during high-temperature pyrolysis of oil shale, which comprises an experiment system, a heating system arranged in the experiment system, a collecting system communicated with the experiment system and a control and data acquisition system electrically connected with the experiment system.)

1. The utility model provides a comprehensive test device of heat conduction, inflation and crack propagation during oil shale pyrolysis which characterized in that: the device comprises an experiment system (A), a heating system (B) arranged in the experiment system (A), a collecting system (C) communicated with the experiment system (A), and a control and data acquisition system (D) electrically connected with the experiment system (A);

the experimental system (A) comprises an experimental cavity shell (1), high-temperature-resistant heat-insulating glass (26) is embedded in the front surface and the rear surface of the experimental cavity shell (1), a test piece container (7) is arranged in the experimental cavity shell (1), a test piece is placed in the test piece container (7), a circulating water cooling device (25) is arranged at the bottom of the test piece, a servo press (2) is arranged at the top of the experimental cavity shell (1), the output end of the servo press (2) is connected with a force transmission plate (3), and the force transmission plate (3) and the test piece container (7) are arranged in an up-and-down corresponding mode;

the heating system (B) comprises a heat insulation layer (4), the heat insulation layer (4) is fixed on the left side surface and the right side surface of the experiment cavity shell (1), a first heating element (5) is fixed on the end surface, located on the inner side of the experiment cavity shell (1), of the heat insulation layer (4), a second heating element (14) is arranged on the top surface of the test piece, and the second heating element (14) is an annular mica electric heating piece;

the collecting system (C) comprises a water bath cooling device (11), the water bath cooling device (11) is located outside the experiment cavity shell (1), a shale oil collecting container (12) is arranged in the water bath cooling device (11), the shale oil collecting container (12) is communicated with one end of an air guide pipe (9), and the other end of the air guide pipe (9) is communicated with the bottom end of the test piece container (7);

the control and data acquisition system (D) comprises a computer (19), and the computer (19) is connected with an infrared thermometer (6), a temperature measurement component, a high-temperature resistant camera (23), a pressure sensor (13) and a displacement sensor (18) through leads.

2. The comprehensive testing device for heat conduction, expansion and crack propagation in high-temperature pyrolysis of oil shale according to claim 1, characterized in that: displacement sensor (18) are located the top of experiment chamber shell (1), one side correspondence of displacement sensor (18) is provided with displacement transmission stick (17), displacement transmission stick (17) stretch into the top surface of experiment chamber shell (1) is connected on the top surface of biography power board (3).

3. The comprehensive testing device for heat conduction, expansion and crack propagation in high-temperature pyrolysis of oil shale according to claim 2, characterized in that: the through-hole has been seted up on the top surface of experiment chamber shell (1), displacement transmission stick (17) stretch into the through-hole and connect dowel steel (3), install heat preservation device (16) in the through-hole, heat preservation device (16), heat preservation (4) are the refractory fiber heat preservation layer material.

4. The comprehensive testing device for heat conduction, expansion and crack propagation in high-temperature pyrolysis of oil shale according to claim 1, characterized in that: the temperature measuring assembly comprises a first K-type thermocouple (8) and a second K-type thermocouple (15), a groove is formed in the bottom surface of the experiment cavity shell (1), the first K-type thermocouple (8) is fixed in the groove, the first K-type thermocouple (8) is arranged on the bottom surface of the test piece, a groove is formed in the bottom surface of the force transmission plate (3), the second K-type thermocouple (15) is fixed in the groove, and the second K-type thermocouple (15) and the top surface of the test piece are arranged correspondingly.

5. The comprehensive testing device for heat conduction, expansion and crack propagation in high-temperature pyrolysis of oil shale according to claim 1, characterized in that: a groove is formed in the inner side wall of the test piece container (7), the pressure sensor (13) is fixed in the groove, and the infrared thermometer (6) is arranged in the experiment cavity shell (1).

6. The comprehensive testing device for heat conduction, expansion and crack propagation in high-temperature pyrolysis of oil shale according to claim 1, characterized in that: high temperature resistant camera (23) inlay and establish the left side of experiment chamber shell (1), the camera lens end cover of high temperature resistant camera (23) has cup jointed thermal-insulated glass cover (24).

7. The comprehensive testing device for heat conduction, expansion and crack propagation in high-temperature pyrolysis of oil shale according to claim 1, characterized in that: the servo press (2) is connected with a first control switch (20), the first heating element (5) is connected with a second control switch (21), and the second heating element (14) is connected with a third control switch (22).

8. The comprehensive testing device for heat conduction, expansion and crack propagation in high-temperature pyrolysis of oil shale according to claim 7, characterized in that: the first control switch (20), the second control switch (21) and the third control switch (22) are respectively connected with a computer.

9. The comprehensive testing device for heat conduction, expansion and crack propagation in high-temperature pyrolysis of oil shale according to claim 1, characterized in that: and a valve (10) is arranged on the air duct (9).

10. A method for testing heat conduction, expansion and crack propagation during high-temperature pyrolysis of oil shale, which is based on the comprehensive testing device for heat conduction, expansion and crack propagation during high-temperature pyrolysis of oil shale in claims 1-9, and comprises the following specific steps: step 1: preparing oil shale into a cylindrical test piece with the height of 200mm and the radius of 50mm, putting the test piece into a test piece container (7), and controlling a servo press (2) through a first control switch (20) to provide constant vertical pressure for the test piece;

step 2: the experimental device is sealed, the heating power of the first heating element (5) is controlled through the second control switch (21), when the infrared thermometer (6) measures that the set temperature is reached, the constant temperature of the experimental cavity is kept through the servo control system, and meanwhile, the displacement value X detected by the displacement sensor (18) when the oil shale sample rises by 10 ℃ every time is recorded, and the formula is adopted:

calculating the linear expansion coefficient of the oil shale, wherein:

linear expansion coefficient of alpha-oil shale

Delta X-displacement sensor twice detection displacement difference

L-specimen length

Δ T-temperature difference recorded twice;

and step 3: after no shale oil is produced, the pyrolysis of the oil shale is proved to be complete, the pressure value provided by the servo press (2) is gradually increased through the first control switch (20) until the displacement sensor returns to zero, and the pressure increased in the vertical direction and the numerical value measured by the lateral pressure sensor (13) are recorded, namely the expansion forces of the oil shale in the vertical direction and the horizontal direction after the pyrolysis;

and 4, step 4: closing the first heating element (5), closing the valve (10), sealing and insulating the experimental cavity at constant temperature, opening the circulating water cooling device (25), setting the constant heating power Q of the second heating element (14) through the third control switch (22), and recording the temperatures T1 and T2 of the upper and lower surfaces of the test piece recorded by the second K-type thermocouple (15) and the first K-type thermocouple (8) after the temperature of the experimental cavity measured by the infrared thermometer (6) is constant again after the device is stable again under the state, so as to pass the formula:

calculating the thermal conductivity coefficient under the high-temperature condition after pyrolysis, wherein:

lambda-coefficient of thermal conductivity of oil shale

Q-constant heating Power Q of the heating element 15

F-area of cross section of test piece

L is the length of the test piece.

Technical Field

The invention relates to the field of testing of rock-soil thermal physical properties, in particular to a comprehensive testing device for heat conduction, expansion and crack propagation in high-temperature pyrolysis of oil shale.

Background

Along with the development of the world economy and science and technology, the importance degree of energy sources to human beings is increasing day by day. Due to human consumption of energy, the energy structure of the world is constantly regulated. Particularly, after the 21 st century, the economy of China is accelerated, and the current energy situation of China is 'rich coal, poor oil and less gas', so that the China urgently needs to find out an alternative energy source for use. Oil shale is widely distributed all over the world as an alternative energy source of petroleum and has huge reserves. The reserves of oil shale in China far exceed the reserves of petroleum in China, and rank the second in the world. Therefore, it is very important to accelerate the development and exploration of oil shale and realize the industrial production of shale oil as soon as possible.

With the development of oil shale mining technology, the in-situ conversion technology of oil shale is the focus of research at home and abroad at present. During in-situ mining, the pyrolysis of the oil shale occurs underground, and the pyrolyzed semicoke, carbon residue and the like are directly left underground, so that a large amount of land cannot be occupied, and the ground environment cannot be greatly polluted. However, the mining method is still in a test stage at present, influences on the underground environment and geology are not clear, various geological problems such as ground collapse, ground subsidence and the like can be caused, and research on physical parameters and thermal physical parameters during pyrolysis of the oil shale is very important for judging the stability of a stratum after pyrolysis of the oil shale.

Because the conventional measuring instrument cannot be applied to the pyrolysis process of the oil shale due to the pyrolysis of the oil shale, a plurality of researches related to the pyrolysis of the oil shale are carried out at home at present. However, due to the fact that substances change when the oil shale is pyrolyzed at a high temperature and cracks are initiated and expanded, the research on the thermal physical coefficient and the expansion of the cracks at the high temperature of the oil shale is difficult to a certain extent, the invention patent with the patent number of CN201310220946.4 discloses a test device for high-temperature and high-pressure pyrolysis reaction, the device simulates the conditions of in-situ pyrolysis of the oil shale, a detection method for the permeability and the mechanical property of the pyrolysis of the oil shale is provided, the thermal physical parameters of the oil shale cannot be measured, and the expansion of the cracks in the pyrolysis process of the oil shale cannot be observed and recorded. Therefore, a technical blank exists in the patent literature for measuring the thermophysical parameters and crack propagation in the high-temperature pyrolysis of the oil shale at home and abroad.

Disclosure of Invention

The invention aims to provide a comprehensive test device for heat conduction, expansion and crack propagation during high-temperature pyrolysis of oil shale, which solves the problems in the prior art, can measure the heat conduction coefficient, the linear expansion coefficient and the expansion force of the oil shale during high-temperature pyrolysis, can observe the crack propagation rule caused by the pyrolysis of the oil shale, and achieves the effect of comprehensive test.

In order to achieve the purpose, the invention provides the following scheme: the invention provides a comprehensive testing device for heat conduction, expansion and crack propagation in high-temperature pyrolysis of oil shale, which comprises an experiment system, a heating system arranged in the experiment system, a collecting system communicated with the experiment system, and a control and data acquisition system electrically connected with the experiment system, wherein the heating system is arranged in the experiment system;

the experimental system comprises an experimental cavity shell, high-temperature-resistant heat-insulating glass is embedded in the front surface and the rear surface of the experimental cavity shell, a test piece container is arranged in the experimental cavity shell, a test piece is placed in the test piece container, a circulating water cooling device is arranged at the bottom of the test piece, a servo press is arranged at the top of the experimental cavity shell, the output end of the servo press is connected with a force transmission plate, and the force transmission plate and the test piece container are arranged in an up-and-down corresponding mode;

the heating system comprises a heat insulation layer, the heat insulation layer is fixed on the left side surface and the right side surface of the experiment cavity shell, a first heating element is fixed on the end surface of the heat insulation layer, which is positioned on the inner side of the experiment cavity shell, a second heating element is arranged on the top surface of the test piece, and the second heating element is an annular mica electric heating sheet;

the collecting system comprises a water bath cooling device, the water bath cooling device is positioned outside the experimental cavity shell, a shale oil collecting container is arranged in the water bath cooling device, the shale oil collecting container is communicated with one end of an air guide pipe, and the other end of the air guide pipe is communicated with the bottom end of the test piece container;

the control and data acquisition system comprises a computer, and the computer is connected with an infrared thermometer, a temperature measurement component, a high-temperature resistant camera, a pressure sensor and a displacement sensor through leads.

Preferably, the displacement sensor is located the top of experiment chamber shell, one side correspondence of displacement sensor is provided with the displacement transmission stick, the displacement transmission stick stretches into the top surface of experiment chamber shell and connects on the top surface of biography power board.

Preferably, a through hole is formed in the top surface of the experimental cavity shell, the displacement transfer rod extends into the through hole to be connected with the force transfer plate, a heat preservation device is installed in the through hole, and the heat preservation device and the heat preservation layer are made of refractory fiber heat preservation layer materials.

Preferably, the temperature measuring assembly comprises a first K-type thermocouple and a second K-type thermocouple, a groove is formed in the bottom surface of the experimental cavity shell, the first K-type thermocouple is fixed in the groove, the first K-type thermocouple is arranged on the bottom surface of the test piece, a groove is formed in the bottom surface of the force transmission plate, the second K-type thermocouple is fixed in the groove, and the second K-type thermocouple is arranged corresponding to the top surface of the test piece.

Preferably, a groove is formed in the inner side wall of the test piece container, the pressure sensor is fixed in the groove, and the infrared thermometer is arranged in the experiment cavity shell.

Preferably, the high temperature resistant camera is embedded in the left side of the experimental cavity shell, and the lens end of the high temperature resistant camera is sleeved with the heat insulation glass cover.

Preferably, the servo press is connected with a first control switch, the first heating element is connected with a second control switch, and the second heating element is connected with a third control switch.

Preferably, the first control switch, the second control switch and the third control switch are respectively connected with a computer.

Preferably, the air duct is provided with a valve.

A method for testing heat conduction, expansion and crack propagation during high-temperature pyrolysis of oil shale comprises the following specific steps: step 1: preparing oil shale into a cylindrical test piece with the height of 200mm and the radius of 50mm, putting the test piece into a test piece container, and controlling a servo press through a first control switch to provide constant vertical pressure for the test piece;

step 2: the experimental device is sealed, the heating power of the first heating element is controlled through the second control switch, when the infrared thermometer reaches a set temperature, the experimental cavity is kept at a constant temperature through the servo control system, and meanwhile, the displacement value X detected by the displacement sensor when the oil shale sample rises by 10 ℃ every time is recorded, and the formula is as follows:

calculating the linear expansion coefficient of the oil shale, wherein:

linear expansion coefficient of alpha-oil shale

Delta X-displacement sensor twice detection displacement difference

L-specimen length

Δ T-temperature difference recorded twice;

and step 3: after observing that no shale oil is generated, the pyrolysis of the oil shale is complete, the pressure value provided by the servo press is gradually increased through the first control switch until the displacement sensor returns to zero, and the pressure increased in the vertical direction and the value measured by the lateral pressure sensor are recorded, namely the expansion force of the oil shale in the vertical direction and the horizontal direction after the pyrolysis;

and 4, step 4: closing the first heating element, closing the valve, sealing and insulating the experimental cavity at constant temperature, opening the circulating water cooling device, setting the constant heating power Q of the second heating element through the third control switch, and recording the temperatures T1 and T2 of the upper and lower surfaces of the test piece recorded by the second K-type thermocouple and the first K-type thermocouple after the device is stable again in the state that the temperature of the experimental cavity is measured by the infrared thermometer and is constant again, so as to pass through the formula:

calculating the thermal conductivity coefficient under the high-temperature condition after pyrolysis, wherein:

lambda-coefficient of thermal conductivity of oil shale

Q-constant heating Power Q of the heating element 15

F-area of cross section of test piece

L is the length of the test piece.

The invention discloses the following technical effects: 1. the invention has simple and efficient operation, and provides the integrated comprehensive test device with visual oil shale pyrolysis heat conduction, expansion and crack propagation, the vertical stress state of the rock mass is kept through the servo press, and the linear expansion coefficient, the expansion force and the heat conduction coefficient of the oil shale in the oil shale pyrolysis process under the action of the dead weight pressure of the overlying strata can be systematically measured in one experiment.

2. The invention provides a new idea for measuring the heat conductivity coefficient of oil shale, which comprises the steps of heating the oil shale to a certain temperature, discharging all gas phase and liquid phase after reaction is completed, and calculating the heat conductivity coefficient of the oil shale at the temperature by defining the heat conductivity coefficient through secondary heating. The method solves the problem that the thermal conductivity of the oil shale at high temperature cannot be measured due to the change of oil shale substances in the pyrolysis process, can measure the thermal conductivity of the oil shale at a specified temperature, and can also be used for measuring the thermal conductivity of other materials with the change of substances along with the temperature.

3. The device is visualization device, has overcome the difficult problem that the oil shale is irregular, difficult to survey because of the crackle development that the pyrolysis leads to, and the whole accessible people of experiment is observed by people, realizes real-time supervision to the inside camera of instrument can record the overall process of oil shale pyrolysis, records the output of oil gas of oil shale pyrolysis process and the expansion of crackle.

The device can determine the heat conductivity coefficient, the linear expansion coefficient and the expansive force of the oil shale during high-temperature pyrolysis, can observe the crack expansion rule caused during the pyrolysis of the oil shale, is simple and efficient to operate, achieves good comprehensive test effect, and fills up the technical blank existing in the patent literature for measuring the thermal physical parameters and the crack expansion during the high-temperature pyrolysis of the oil shale at home and abroad.

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 front view of the comprehensive testing device for heat conduction, expansion and crack propagation in high-temperature pyrolysis of oil shale according to the present invention;

FIG. 2 is a top view of the integrated testing apparatus for thermal conductivity, expansion and crack propagation in high temperature pyrolysis of oil shale according to the present invention;

FIG. 3 is a schematic diagram of a constant pressure control of the servo press;

FIG. 4 is a schematic diagram of temperature control of the first heat-generating element;

the system comprises an A-experiment system, a B-heating system, a C-collecting system, a D-control and data acquisition system, a 1-experiment cavity shell, a 2-servo press, a 3-force transmission plate, a 4-heat insulation layer, a 5-first heating element, a 6-infrared thermometer, a 7-test piece container, an 8-first K-type thermocouple, a 9-air guide pipe, a 10-valve, an 11-water bath cooling device, a 12-shale oil collecting container, a 13-pressure sensor, a 14-second heating element, a 15-second K-type thermocouple, a 16-heat insulation device, a 17-displacement transmission rod, an 18-displacement sensor, a 19-computer, a 20-first control switch, a 21-second control switch, a 22-third control switch, a, 23-high temperature resistant camera, 24-heat insulation glass cover, 25-circulating water cooling device and 26-high temperature resistant heat insulation glass.

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. 1-4, the invention provides a thermal physical property testing device under the high-temperature pyrolysis condition of oil shale, which comprises an experiment system a, a heating system B arranged in the experiment system a, a collecting system C and a control and data acquisition system D. The device comprises an experimental cavity shell 1, a servo press 2, a force transmission plate 3, a heat preservation layer 4, a first heating element 5, an infrared thermometer 6, a test piece container 7, a first K-type thermocouple 8, an air guide pipe 9, a valve 10, a water bath cooling device 11, a shale oil collecting container 12, a pressure sensor 13, a second heating element 14, a second K-type thermocouple 15, a heat preservation device 16, a displacement transmission rod 17, a displacement sensor 18, a computer 19, a first control switch 20, a second control switch 21, a third control switch 22, a high-temperature resistant camera 23, a heat insulation glass cover 24, a circulating water cooling device 25 and high-temperature resistant heat insulation glass 26.

The experiment system A consists of an experiment cavity shell 1 and internal elements thereof, the front and back surfaces of the experiment cavity shell 1 are composed of high-temperature-resistant heat-insulating glass 26, the heat insulation effect can be achieved, and the reaction condition in the experiment cavity can be observed through the glass. For metal atress skeleton about from top to bottom, servo press 2 is connected to upper portion skeleton, and servo press 2 provides the vertical pressure of invariable equipartition for the test piece through biography power board 3. A displacement transmission stick 17 is connected on 3 upper portions of biography power board, stretches out the outer displacement sensor 18 of connecting of experiment chamber through the trompil, and heat preservation device 16 is passed through to trompil department, adopts refractory fiber heat preservation shutoff exit gap to do the heat preservation. The test piece container 7 is arranged right below the servo press 2 and is made of high-temperature and high-pressure resistant glass. A circulating water cooling device 25 is arranged in the lower framework of the position opposite to the test piece, and the heat of the test piece is absorbed at the bottom of the test piece when the heat conductivity coefficient is measured.

The heating system B consists of a heating element and a heat preservation layer 4, wherein the heat preservation layer 4 is made of refractory fiber heat preservation layers and is arranged inside the left and right metal frames of the experimental cavity and is fully paved with the left and right metal frames. The heating element comprises a first heating element 5 and a second heating element 14, the first heating element 5 is an electric heating sheet and is fixed on the end face of the heat-insulating layer 4, which is located on the inner side of the experimental cavity shell 1, and the second heating element 14 is an annular mica electric heating sheet and is fixed on the top end of the test piece.

The collecting system C is composed of an air duct 9, a valve 10, a water bath cooling device 11 and a shale oil collecting container 12. Oil gas generated in the pyrolysis process enters the shale oil collecting container 12 through the gas guide pipe 9 and passes through the water bath cooling device 11, so that the shale oil is cooled and left in the shale oil collecting container 12, and the gas is discharged out of the shale oil collecting container 12.

The control and data acquisition system D is composed of an infrared thermometer 6, a first K-type thermocouple 8, a second K-type thermocouple 15, a pressure sensor 13, a displacement sensor 18, a computer 19, a first control switch 20, a second control switch 21, a third control switch 22 and a high-temperature resistant camera 23. The infrared thermometer 6 is arranged inside the experiment cavity shell 1. The first K-type thermocouple 8 is fixed on the upper surface of the lower framework of the test piece through a groove reserved in the lower framework of the experimental cavity and is used for measuring the temperature of the bottom of the test piece. And a second K-type thermocouple 15 is fixed on the lower surface of the force transmission plate 3 through a groove reserved on the lower surface of the force transmission plate 3 and is used for measuring the temperature of the top of the test piece. The pressure sensor 13 is fixed in a recess made in the inner side wall of the specimen container 7. The displacement sensor 18 is arranged outside the laboratory cavity and connected to the displacement transmission rod 7. High temperature resistant camera 23 inlays in experiment chamber shell 1 left side skeleton, because high temperature resistant camera 23 need maintain lasting wind and water cooling, so arrange thermal-insulated glass cover 24 in order to reduce because of the heat that high temperature camera wind and water cooling run off. The computer 19 is connected with the infrared thermometer 6, the second K-type thermocouple 15, the first K-type thermocouple 8, the pressure sensor 13, the displacement sensor 18 and the high-temperature resistant camera 23 through leads, can display data collected by the infrared thermometer 6, the second K-type thermocouple 15, the first K-type thermocouple 8, the pressure sensor 13 and the displacement sensor 18, and records the generation of oil shale oil gas and the development of cracks in the pyrolysis process through the high-temperature resistant camera 23. The first control switch 20 is connected with the computer and the servo press machine 2 through a lead wire, so that the pressure of the servo press machine 2 can be controlled, the second control switch 21 is connected with the computer and the first heating element 5, the heating power of the first heating element 5 is adjusted through data detected by the infrared thermometer 6 to control the constant temperature in the experimental cavity, the third control switch 22 is connected with the computer and the second heating element 14 through a lead wire, so that the constant heating power of the second heating element 14 can be set, and the experimental test piece can be heated for the second time.

The device comprises the following specific implementation processes:

step 1: the oil shale is prepared into a cylindrical test piece with the height of 200mm and the radius of 50mm, the test piece is placed into a test piece container 7, and the servo press machine 2 is controlled through the first control switch 20 to provide constant vertical pressure for the test piece.

Step 2: the experimental device is sealed, the heating power of the first heating element 5 is controlled through the second control switch 21, when the infrared thermometer 6 reaches a set temperature, the temperature of the experimental cavity is kept constant through the servo control system, and meanwhile, the displacement value X detected by the displacement sensor 18 when the oil shale sample rises by 10 ℃ every time is recorded, and the formula is as follows:

calculating the linear expansion coefficient of the oil shale, wherein:

linear expansion coefficient of alpha-oil shale

Delta X-displacement sensor twice detection displacement difference

L-specimen length

Delta T-temperature difference recorded twice

And step 3: after observing that no shale oil is generated, the pyrolysis of the oil shale is complete, the pressure value provided by the servo press 2 is gradually increased through the first control switch 20 until the displacement sensor 18 returns to zero, and the increased pressure in the vertical direction and the value measured by the lateral pressure sensor 13 are recorded, namely the expansion forces in the vertical direction and the horizontal direction of the oil shale after the pyrolysis.

And 4, step 4: closing the first heating element 5, closing the valve 10, sealing and insulating the experimental cavity at constant temperature, opening the circulating water cooling device 25, setting the constant heating power Q of the heating element 14 through the third control switch 22, and after the device is stable again in the state, namely after the temperature of the experimental cavity measured by the infrared thermometer 6 is constant again, recording the temperatures T1 and T2 of the upper and lower surfaces of the test piece recorded by the second K-type thermocouple 15 and the first K-type thermocouple 8, and according to the formula:

calculating the thermal conductivity coefficient under the high-temperature condition after pyrolysis, wherein:

lambda-coefficient of thermal conductivity of oil shale

Q-constant heating Power Q of the heating element 15

F-area of cross section of test piece

L is the length of the test piece.

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.