CN219101317U

CN219101317U - Underground in-situ pyrolysis simulation system for coal

Info

Publication number: CN219101317U
Application number: CN202123442942.XU
Authority: CN
Inventors: 吴志强; 高琨; 杨伯伦; 俞尊义; 杨盼曦; 张�杰; 郭伟; 魏进家; 李明杰
Original assignee: Xian Jiaotong University; Huaneng Group Technology Innovation Center Co Ltd
Current assignee: Xian Jiaotong University; Huaneng Group Technology Innovation Center Co Ltd
Priority date: 2021-12-31
Filing date: 2021-12-31
Publication date: 2023-05-30
Anticipated expiration: 2031-12-31

Abstract

The utility model belongs to the field of energy exploitation, and particularly relates to an underground in-situ pyrolysis simulation system for coal, which comprises a high-temperature high-pressure air supply module, a coal in-situ pyrolysis module, a servo control module and a product regulation and separation module; the high-temperature high-pressure gas supply module is used for providing high-temperature high-pressure steam and inert gas; the coal in-situ pyrolysis module is used for pyrolyzing coal samples; the servo control module is used for accurately detecting the simulation data in real time and controlling pyrolysis reaction according to the simulation data; the product regulation and separation module is used for separating pyrolysis products. The utility model simulates the coal pyrolysis in an in-situ link and provides theoretical basis and laboratory simulation basis for underground in-situ pyrolysis of coal.

Description

Underground in-situ pyrolysis simulation system for coal

Technical Field

The utility model belongs to the field of energy exploitation, and particularly relates to an underground in-situ pyrolysis simulation system for coal.

Background

The energy structure of China presents the endowment characteristics of 'oil deficiency, gas deficiency and relatively rich coal', the ratio of coal in the total consumption amount of primary energy is about 58.3 percent in 2020, the same ratio is increased by 0.6 percent, and the coal still occupies the main place in the energy structure of China in a quite long period in the future. In 2020, the external dependence of oil gas in China respectively reaches 73.5% and 43.2%, and the low-rank coal resources in China occupy more than half of the total amount of coal resources, and volatile substances in the low-rank coal resources are a large amount of oil gas resources, so that the development of the technology of coal-to-oil and coal-to-natural gas with coal pyrolysis as a core has important significance for realizing autonomous supply of domestic oil gas.

The main coal pyrolysis technology at present is ground pyrolysis, namely coal is mined and transported underground, and enters ground pyrolysis equipment to be converted into tar, coal gas and semicoke products after washing and selecting. But the ground pyrolysis has the problems of large occupied area, excessive productivity of pyrolysis semicoke, ground collapse after exploitation, air pollution, water pollution and the like.

Underground pyrolysis of coal, namely pyrolysis of coal directly under the ground through heat transfer of a thermal carrier, and extraction of the obtained oil gas products to the ground through a production well for separation processing. Compared with the conventional ground pyrolysis technology, the underground in-situ pyrolysis has the characteristics of small occupied area, capability of preventing ground collapse, small carbon emission footprint, low exploitation cost and the like, and has wide prospect.

The underground pyrolysis of coal is pyrolysis under a certain stress condition of raw rock, and the in-situ pyrolysis is characterized in that deep coal rock often bears higher axial pressure, confining pressure and pore pressure, and the existing coal compression pyrolysis device is mainly divided into a compression thermogravimetric analyzer, a compression screen reactor, a compression fixed bed reactor, a compression sedimentation tube reactor, a high-temperature high-pressure triaxial test machine and the like.

The pressurized thermogravimetric analyzer is often used for researching the weight loss characteristic and the dynamic characteristic of a sample, and is suitable for the pressurized pyrolysis test of small-batch mg-g coal. The pressurized screen reactor is mostly used for the fast pyrolysis of small particle coal samples; the pressurized sedimentation tube reactor is a entrained-flow reactor, can provide extremely high heating rate and is also suitable for single-particle reaction conditions. The pressurized fixed bed reactor is a gas-solid on-line reaction evaluation system which is used for coal pyrolysis research, but the pressurizing process is still a certain gap compared with the pressure of the oil-rich coal in the underground actual environment.

The existing high-pressure pyrolysis device is often aimed at the rapid pyrolysis of small-particle coal, and lacks a pyrolysis device for simulating the underground environment under axial and circumferential pressure. Therefore, the underground in-situ pyrolysis simulation system for coal is of great significance to energy development.

Disclosure of Invention

The utility model aims to provide an underground in-situ pyrolysis simulation system for coal, which aims to solve the technical problems that the existing high-pressure pyrolysis device cannot simulate underground coal state, the accurate calculation of the steam injection pyrolysis characteristic of coal under high pressure is lacked, and the relation between the product distribution rule and the temperature and the pressure is realized.

In order to achieve the above purpose, the present utility model adopts the following technical scheme:

the underground in-situ pyrolysis simulation system for the coal comprises a high-temperature high-pressure air supply module, a coal in-situ pyrolysis module, a servo control module and a product regulation and separation module;

the high-temperature high-pressure gas supply module gas pipeline is connected with the coal in-situ pyrolysis module, the product outlet of the coal in-situ pyrolysis module is connected with the product regulation and separation module, and the servo control module is connected with the coal in-situ pyrolysis module;

the high-temperature high-pressure gas supply module is used for supplying high-temperature high-pressure steam and inert gas to the coal in-situ pyrolysis module;

the coal in-situ pyrolysis module is used for pyrolyzing a coal sample by utilizing high-temperature and high-pressure steam and inert gas provided by the high-temperature and high-pressure gas supply module and producing pyrolysis products;

the servo control module is used for monitoring pyrolysis reaction data in real time and controlling pyrolysis reaction rate according to the pyrolysis reaction data;

the product regulation and separation module is used for separating pyrolysis products.

The utility model further improves that: the high-temperature high-pressure air supply module comprises a steam generator, a gas busbar, a first high-pressure needle valve and a gas heater;

the coal in-situ pyrolysis module comprises a first pipeline heater, a second pipeline heater and a pyrolysis reactor;

the servo control module comprises a data sensor, a data acquisition system and an automation control console, wherein the data sensor comprises a first mass flowmeter, a first temperature sensor, a first pressure sensor, a thermocouple temperature sensor, a second mass flowmeter, a second temperature sensor, a second pressure sensor and a third mass flowmeter, the data acquisition system is used for acquiring monitoring data of each sensor in real time, and the automation control console is used for acquiring the monitoring data of each sensor according to the data acquisition system and controlling the pyrolysis and product separation processes of coal samples;

the product regulation and separation module comprises a catalytic fluidized bed reactor, a condenser, a gas-liquid separator, a tar collecting bottle, a gas separator, a drying pipe, a three-way valve, a gas stove, a gas collecting bottle and a second high-pressure needle valve;

the steam generator output port is connected with a first input port of a first mass flowmeter, a second input port of the first mass flowmeter is connected with a gas busbar output port, the first mass flowmeter output port is connected with a first input port of a gas heater, the gas heater output port is connected with a first pipeline heater input port through a first stop valve, a first temperature sensor and a first pressure sensor are arranged between the first stop valve and the first pipeline heater, the first pipeline heater output port is connected with a pyrolysis reactor input port, and the pyrolysis reactor output port is connected with a second pipeline heater input port through a second stop valve;

the second pipeline heater output port is connected with a second mass flowmeter input port, a second temperature sensor and a second pressure sensor are arranged between the second pipeline heater and the second mass flowmeter, the second mass flowmeter output port is connected with a catalytic fluidized bed reactor input port, the catalytic fluidized bed reactor output port is connected with a condenser input port, the condenser output port is connected with a gas-liquid separator input port, a gas-liquid separator liquid output port is connected with a tar collecting bottle, a gas output port of the gas-liquid separator is connected with a gas separator input port, and a first gas outlet of the gas separator is connected with a second input port of the gas heater through a second high-pressure needle valve;

the gas separator second gas outlet links to each other with the dry pipe input port, the dry pipe delivery outlet links to each other with the third mass flowmeter input port, the third mass flowmeter delivery outlet links to each other with the tee bend valve input port, the first delivery outlet of tee bend valve links to each other with the gas-cooker, the tee bend valve second delivery outlet links to each other with the gas collecting bottle, first mass flowmeter, first temperature sensor, first pressure sensor, second mass flowmeter, second temperature sensor, second pressure sensor, third mass flowmeter and pyrolysis reactor's signal delivery outlet links to each other with data acquisition system signal input port, data acquisition system signal delivery outlet links to each other with automated console signal input port, automated console signal delivery outlet links to each other with pyrolysis reactor signal input port.

The utility model further improves that: the pyrolysis reactor comprises a hydraulic machine, a pressure chamber, a servo valve and a heating electric furnace, wherein the pressure chamber is arranged in the hydraulic machine, an electric heating furnace is arranged on the outer side of the hydraulic machine, and the servo valve is arranged on the top of the hydraulic machine;

the hydraulic press comprises a main machine base, a main machine frame, a supporting beam, a hydraulic cylinder, a pressure transmission column, a pressure plate, a shaft pressure head, pyrophyllite powder/salt rings, a confining pressure head and a guide rail;

the pressure chamber comprises a pressure chamber base, a sample carrier, a pressure chamber cylinder, a distributor, a porous guide plate, a thermocouple temperature sensor, a sealing ring and a water cooling sleeve.

The utility model further improves that: host computer frame is equipped with above the host computer base, host computer frame top is equipped with the supporting beam, the supporting beam middle part is equipped with hydraulic cylinder, the hydraulic cylinder top is equipped with the servo valve, the hydraulic cylinder below is equipped with the pressure transmission post, the pressure transmission post below is equipped with the pressure plate, the pressure plate below is equipped with the axle pressure head, the axle pressure head both sides are equipped with the confining pressure head, the axle pressure head below is equipped with the distributor, the distributor top is equipped with the pipe, and the pipe links to each other with high temperature high pressure air feed module, and the below is equipped with a plurality of pipes as gas outlet, host computer base top is equipped with the guide rail in the host computer frame, the guide rail top is equipped with the pressure chamber base, the pressure chamber base comprises two coaxial cylinders, and the cylinder diameter of below is greater than the cylinder diameter of top, cylinder terminal surface is equipped with leaf wax stone powder/salt ring and pressure chamber barrel from inside to outside, leaf wax stone powder/salt ring are the drum, the inside is equipped with the sample carrier, the pressure chamber barrel outside is equipped with the electric heating furnace, all is equipped with water cooling jacket, the pressure chamber top is equipped with the guide plate, the pressure plate top is equipped with the porous guide plate, the porous guide plate top is equipped with the porous air deflector below the porous carrier, porous sensor is equipped with above the porous guide plate, porous carrier is equipped with above the porous guide plate.

The utility model further improves that: the porous guide plate is in a shape of a cake, and a plurality of round holes are formed in the upper round surface and the lower round surface of the porous guide plate.

The utility model further improves that: the upper part of the distributor is in a shape of a round cake, a round hole is formed in the top of the round cake, a plurality of vertical hollow cylinders are arranged below the round cake, a plurality of round holes are formed in the surfaces of the hollow cylinders, and a static mixer is arranged inside the hollow cylinders.

The utility model further improves that: the pressure chamber is provided with a visual window for directly observing pyrolysis of the internal coal sample on the surface of the pressure chamber.

The utility model further improves that: the maximum pressure of the hydraulic machine is 1000KN, and the maximum shaft pressure confining pressure is 20Mpa.

The utility model further improves that: the rated temperature of the first pipeline heater and the rated temperature of the second pipeline heater are both larger than 360 ℃.

Compared with the prior art, the utility model at least comprises the following beneficial effects:

1. the utility model simulates the coal pyrolysis in an in-situ link, and provides a theoretical basis and a laboratory simulation basis for the underground in-situ pyrolysis of the coal;

2. according to the utility model, the hydrocarbon-containing pyrolysis gas is recycled through the second high-pressure needle valve, so that the heat transfer efficiency can be enhanced, the product distribution is improved, and the heat exchange means is simulated under the real working condition of the laboratory environment.

3. The three addition modes of the propping agent in the coal sample can effectively prevent pore canal from fracturing in the pyrolysis process, protect the pyrolysis process, strengthen the convection heat transfer of steam and improve the heating efficiency.

4. According to the utility model, through the primary catalytic regulation and control of the propping agent, the primary reaction of the coal pyrolysis is regulated and controlled, so that the oil gas yield obtained by the coal pyrolysis is improved; and the secondary reaction of the pyrolysis of the coal is regulated and controlled through the secondary catalytic regulation and control of the catalytic fluidized bed, so that the quality of the obtained tar is improved.

Drawings

The accompanying drawings, which are included to provide a further understanding of the utility model and are incorporated in and constitute a part of this specification, illustrate embodiments of the utility model and together with the description serve to explain the utility model. In the drawings:

FIG. 1 is a system block diagram of a coal underground in situ pyrolysis simulation system of the present utility model;

FIG. 2 is a schematic diagram of a pyrolysis reactor structure of an underground in-situ pyrolysis simulation system for coal according to the utility model;

FIG. 3 is a system flow diagram of a coal underground in situ pyrolysis simulation system of the present utility model;

FIG. 4 is a graph of a phi 200 x 400mm coal sample borehole;

FIG. 5 is a schematic diagram of a distributor in an underground in-situ pyrolysis simulation system for coal according to the present utility model;

FIG. 6 is a schematic diagram of a porous baffle structure in a coal underground in-situ pyrolysis simulation system according to the present utility model;

FIG. 7 is a schematic view of the position of a visual window in a coal underground in-situ pyrolysis simulation system according to the present utility model;

FIG. 8 is a schematic diagram of an upper inlet and upper outlet pyrolysis reactor in a coal underground in-situ pyrolysis simulation system according to the utility model.

In the figure, 1, a steam generator; 2. a gas bus; 3. a first high pressure needle valve; 4. a first mass flow meter; 5. a second high pressure needle valve; 6. a gas heater; 7. a first stop valve; 8. a first temperature sensor; 9. a first pressure sensor; 10. a first pipeline heater; 20. a pyrolysis reactor; 21. a host base; 22. a host frame; 23. a support beam; 24. a hydraulic cylinder; 25. a servo valve; 26. a pressure transmission column; 27. a pressure plate; 28. a pressure chamber base; 29. a shaft pressing head; 30. a confining pressure head; 31. a style carrier; 32. a pressure chamber cylinder; 33. a distributor; 34. a porous baffle; 35. pyrophyllite powder/salt rings; 36. an electric heating furnace; 37. a water cooling sleeve; 38. a seal ring; 39. a guide rail; 40. a thermocouple temperature sensor; 41. a first stop valve; 42. a second pipeline heater; 43. a second temperature sensor; 44. a second pressure sensor; 45. a second mass flow meter; 46. a catalytic fluidized bed reactor; 47. a condenser; 48. a gas-liquid separator; 49. a tar collection bottle; 50. a gas separator; 51. a drying tube; 52. a third mass flow meter; 53. a three-way valve; 54. a gas range; 55. a gas collection bottle; 61. a data acquisition system; 62. an automation console.

Detailed Description

The utility model will be described in detail below with reference to the drawings in connection with embodiments. It should be noted that, without conflict, the embodiments of the present utility model and features of the embodiments may be combined with each other.

The following detailed description is exemplary and is intended to provide further details of the utility model. Unless defined otherwise, all technical terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this utility model belongs. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments in accordance with the utility model.

As shown in fig. 1, the underground in-situ pyrolysis simulation system for coal comprises a high-temperature high-pressure air supply module, a coal in-situ pyrolysis module, a servo control module and a product regulation and separation module;

the high-temperature high-pressure air supply module comprises a steam generator 1, a gas busbar 2, a first high-pressure needle valve 3 and a gas heater 6;

the in-situ coal pyrolysis module comprises a first pipeline heater 10, a second pipeline heater 42 and a pyrolysis reactor 20;

the servo control module comprises a data sensor, a data acquisition system 61 and an automation control console 62, wherein the data sensor comprises a first mass flowmeter 4, a first temperature sensor 8, a first pressure sensor 9, a thermocouple temperature sensor 40, a second mass flowmeter 45, a second temperature sensor 43, a second pressure sensor 44 and a third mass flowmeter 52, the data acquisition system 61 can accurately monitor each test data in real time, and the automation control console 62 can realize automatic loading and unloading according to set data through a program;

the product regulation and separation module comprises a catalytic fluidized bed reactor 46, a condenser 47, a gas-liquid separator 48, a tar collecting bottle 49, a gas separator 50, a drying pipe 51, a three-way valve 53, a gas stove 54, a gas collecting bottle 55 and a second high-pressure needle valve 5;

as shown in fig. 3, the output port of the steam generator 1 is connected with the first input port of the first mass flowmeter 4, the second input port of the first mass flowmeter 4 is connected with the output port of the gas busbar 2, the output port of the first mass flowmeter 4 is connected with the first input port of the gas heater 6, the output port of the gas heater 6 is connected with the input port of the first pipeline heater 10 through the first stop valve 7, a first temperature sensor 8 and a first pressure sensor 9 are arranged between the first stop valve 7 and the first pipeline heater, the output port of the first pipeline heater 10 is connected with the input port of the pyrolysis reactor 20, the output port of the pyrolysis reactor 20 is connected with the input port of the second pipeline heater 42 through the second stop valve 41, the output port of the second pipeline heater 42 is connected with the input port of the second mass flowmeter 45, a second temperature sensor 43 and a second pressure sensor 44 are arranged between the second pipeline heater 42 and the second mass flowmeter 45, the output port of the second mass flowmeter 45 is connected with the input port of the catalytic fluidized bed reactor 46, the output port of the catalytic fluidized bed reactor 46 is connected with the input port of the condenser 47, the output port of the condenser 47 is connected with the input port of the gas-liquid separator 48, the liquid output port of the gas-liquid separator 48 is connected with the tar collecting bottle 49, the gas output port of the gas-liquid separator 48 is connected with the input port of the gas separator 50, the first gas outlet port of the gas separator 50 is connected with the second input port of the gas heater 6 through the second high-pressure needle valve 5, the second gas outlet port of the gas separator 50 is connected with the input port of the drying pipe 51, the output port of the drying pipe 51 is connected with the input port of the third mass flowmeter 52, the output port of the third mass flowmeter 52 is connected with the input port of the three-way valve 53, the first output port of the three-way valve 53 is connected with the gas stove 54, the second output port of the three-way valve 53 is connected with the gas collection bottle 55, the signal output ports of the first mass flowmeter 4, the first temperature sensor 8, the first pressure sensor 9, the second mass flowmeter 45, the second temperature sensor 43, the second pressure sensor 44, the third mass flowmeter 52 and the pyrolysis reactor 20 are connected with the signal input port of the data acquisition system 61, the signal output port of the data acquisition system 61 is connected with the signal input port of the automation control console 62, and the signal output port of the automation control console 62 is connected with the signal input port of the pyrolysis reactor 20; the data acquisition system 61 is a distributed control system DCS, and the automation console 62 is an automatic control system ACS.

The high-temperature high-pressure gas supply module can provide high-temperature high-pressure steam, inert gas, reducing gas or low-concentration oxygen-containing gas and the like for pyrolysis and fracturing of a sample to generate pores, can provide water vapor with the temperature of 600 ℃ and the pressure of 5Mpa, nitrogen with the temperature of 500 ℃ and the pressure of 10Mpa and the like, and has the gas flow rate of up to 2L/min;

as shown in fig. 2, the pyrolysis reactor 20 comprises a hydraulic machine, a pressure chamber, a servo valve 25 and a heating electric furnace 36, wherein the pressure chamber is arranged in the hydraulic machine, the electric heating furnace 36 is arranged outside the hydraulic machine, and the servo valve 25 is arranged at the top of the hydraulic machine;

the hydraulic press comprises a main machine base 21, a main machine frame 22, a supporting beam 23, a hydraulic cylinder 24, a pressure transmission column 26, a pressure plate 27, a shaft pressure head 29, pyrophyllite powder/salt rings 35, a confining pressure head 30 and a guide rail 39;

the pressure chamber comprises a pressure chamber base 28, a sample carrier 31, a pressure chamber cylinder 32, a distributor 33, a porous deflector 34, a thermocouple temperature sensor 40, a sealing ring 38 and a water cooling sleeve 37;

the host computer frame 22 is arranged above the host computer base 21, the supporting beam 23 is arranged at the top of the host computer frame 22, the hydraulic cylinder 24 is arranged in the middle of the supporting beam 23, the servo valve 25 is arranged above the hydraulic cylinder 24, the pressure transmission column 26 is arranged below the hydraulic cylinder 24, the pressure plate 27 is arranged below the pressure plate 27, the shaft pressure head 29 is arranged on two sides of the shaft pressure head 29, the confining pressure head 30 is arranged below the shaft pressure head 29, the distributor 33 is arranged above the distributor 33, the guide pipes are connected with the high-temperature high-pressure air supply module, a plurality of guide pipes are arranged below the guide pipes and serve as air outlets, the guide rail 39 is arranged above the host computer base 21 in the host computer frame 22, the pressure chamber base 28 is arranged above the guide rail 39, the pressure chamber base 28 is formed by two coaxial cylinders, the diameter of the cylinder below is larger than the diameter of the cylinder above the guide rail, the cylinder end face of the pressure chamber base 28 is provided with the leaf wax stone powder/salt ring 35 and the pressure chamber cylinder 32 from inside to outside, the sample carrier 31 is arranged inside, the electric heating furnace 36 is arranged outside the pressure chamber cylinder body, the electric heating furnace 36 is provided with the water cooling sleeve 37, the upper end face of the electric heating furnace 36 is provided with the guide pipe 37, the guide plate 34 is arranged above the guide plate 34, the guide plate 34 is arranged below the guide plate 34, the guide plate is arranged above the guide plate 34, and the guide plate is arranged above the guide plate 34, the guide plate is arranged above the guide plate 34, and the guide plate is arranged above the guide plate is arranged on the guide plate, and the guide plate is arranged on the air.

As shown in fig. 5, the upper part of the distributor 33 is in a shape of a round cake, a round hole is formed in the top of the round cake, a plurality of vertical hollow cylinders are arranged below the round cake, and a plurality of round holes are formed in the surfaces of the hollow cylinders.

As shown in fig. 6, the porous baffle 34 is in the shape of a circular cake, and the upper and lower circular surfaces are provided with a plurality of circular holes.

The pyrolysis reactor 21 can carry out steam injection pyrolysis and direct heating pyrolysis on small-size coal blocks phi 50 x 100mm, study pyrolysis characteristics, and simultaneously can carry out injection heat carrier pyrolysis on large-size coal blocks phi 200 x 400mm, simulate convection heating in an underground pipeline, and explore a temperature distribution rule and a product distribution rule in the pyrolysis process.

The automation control console 62 comprises a 16-channel data acquisition instrument and accurately detects temperature, pressure and flow parameters in the acquisition test process; displaying temperature, pressure and flow parameters measured by a sensor in the test process in real time, generating data, and generating a pressure loading rate curve, a temperature rise curve and a real-time flow curve; the external electric heating furnace 36 is programmed to heat, and the heating speed of different stages can be controlled by setting heating parameters; the pressure loading of the test process and the pressure relief work of the device at the end of the test can be accurately controlled by the control console at the beginning of the test.

Sample carrier 31 has different specifications of phi 200 x 400mm, phi 50 x 100mm and the like, and is used in combination with a sample, wherein phi 50 x 100mm sample steam injection directly enters from a top gas channel, and flows out from the bottom after pyrolysis is finished; a 200 x 400mm sample carrier requires a distributor 33.

As shown in fig. 5, the distributor 33 further includes four air inlet pipes with a length of Φ15×250mm, each air inlet pipe is provided with a plurality of air outlet holes with a length of Φ3mm, and the air inlet pipe is internally provided with a static mixer with a length of Φ10×240, so as to play a role in enhancing heat exchange.

And a 50 mm-20 mm window is further arranged in the middle of the pressure chamber, and pyrolysis of the internal coal sample can be directly observed on the surface of the pressure chamber.

For a Φ50×100mm sample, thermocouple temperature sensor 40 is inserted into the sample center from the bottom, detecting the temperature change at the center; for the 200 x 400mm sample, the thermocouple temperature sensors 40 were four in total, one at the center height of 200mm, one at the center height of 150mm, one at the center height of 60mm, one at the center height of 100mm, and one at the center height of 85mm, and detect the temperature distribution during pyrolysis in the lateral and longitudinal directions, respectively.

The heating temperature of the first pipeline heater 10 and the second pipeline heater 42 is higher than 360 ℃, so that pyrolysis volatile matters are prevented from condensing in the pipeline to block the pipeline.

The hydraulic press with 1000KN is adopted, the maximum axial pressure confining pressure can reach 20Mpa, the maximum heating electric furnace can reach 700 ℃, and the pyrolysis of the coal bed under the geological environment with the buried depth of 1000m can be simulated.

The pyrolysis reactor adopts an integral structure, and the pressure chamber can reciprocate on the guide pipe 39, and the pressure chamber cylinder 32 is lifted by controlling the lifting equipment, so that the sample can be conveniently filled.

The seal ring 38 of the pressure chamber uses a graphite packing material which can withstand high temperatures, is strong and durable, waterproof and rust-proof, and has good flexibility.

The pressure chamber comprises a visual window, a coal sample is adopted to replace part of confining pressure medium, and the pyrolysis process of the internal coal sample can be directly observed on the surface of the pressure chamber.

As shown in FIG. 7, the visual window can be installed in two ways, a circle of window can be formed in the wall of the pressure chamber, rectangular windows with different sizes can also be formed in the wall of the pressure chamber, and a sapphire glass window is installed on the wall of the pressure chamber. For a 50 x 100mm sample, a circle of window with the height of 20mm is formed in the wall of the pressure chamber, the window is made of sapphire glass, and the position of the pyrophyllite powder/salt ring 35 is replaced by the sapphire glass; for phi 200 x 400mm samples, a 50 x 80mm sapphire glass window is formed in the wall of the pressure chamber, the pyrophyllite powder/salt ring 35 is replaced by a coal sample, and the window can be arranged at the middle and lower parts of the wall of the pressure chamber.

The multifunctional propping agent with the catalytic function and the heat conduction function is added in the sample, so that the sample is not crushed in the pyrolysis process, the convection heating of steam is enhanced, and the pyrolysis of the coal sample is regulated and controlled through the catalytic function.

The propping agent is prepared by crushing and drying red mud, grinding the red mud to 150 meshes, and then adding an adhesive, a peptizing agent, an extrusion aid, a pore-expanding agent and water according to the following steps of 5:2:0.5:0.25:0.25:2, uniformly mixing, and drying for use. The adhesive is one or more of cellulose, starch and phenolic resin; the peptizing agent is one or two of acetic acid, formic acid and other organic acids; the extrusion assisting agent is sesbania powder; and the pore-expanding agent uses mesitylene.

The propping agent has three addition modes; (1) preparing into particles, and adding the particles into an air inlet duct; (2) preparing gel, and coating on the outer wall of the pore canal; (3) The red mud is mixed with crushed coal, pulverized coal, sodium carboxymethylcellulose and water and then compressed into lump coal for use.

The thermocouple temperature sensor 40 is used for detecting the temperature change in the pyrolysis coal sample in real time on the transverse gradient and the longitudinal gradient, and can draw an internal temperature distribution diagram in the pyrolysis process of the coal sample.

The bottom of the pressure chamber is provided with a porous diversion trench 34 which is convenient for the outflow of volatile matters and prevents the volatile matters from being blocked in the pressure chamber and the pipeline.

The catalytic fluidized bed reactor 46 is a regulating reactor, a catalyst is placed in the middle of the catalytic fluidized bed reactor 46, and catalytic regulation is performed for the secondary reaction of the pyrolysis volatile matters.

The catalyst in the catalytic fluidized bed reactor 46 is prepared from red mud and deionized water according to a ratio of 1:1.5, respectively modulating by acid and alkali, and drying to prepare the product; the acid solution is one or more of sulfuric acid, hydrochloric acid and nitric acid; the alkaline solution is one or two of sodium hydroxide and ammonia water.

Aiming at the problem that the pyrolysis volatile matters are easy to condense and block the pipeline, the first pipeline heater 10 and the second pipeline heater 42 are arranged at the outlet and the inlet of the pyrolysis reactor 2, the heating temperature of the first pipeline heater and the second pipeline heater is more than 400 ℃ and is higher than the condensing temperature of tar, so that the pyrolysis volatile matters can be effectively prevented from condensing and blocking the pipeline in the pipeline.

The first pressure sensor 9 and the second pressure sensor 44 are liquid pressure sensors, and the automation control console 62 controls the pressure in the pressure chamber in the pyrolysis reactor 20 to be consistent with the preset pressure according to signals fed back by the first pressure sensor 9 and the second pressure sensor 44, so that the pressure closed-loop control of the shaft confining pressure system is formed.

Example 2

An underground in-situ pyrolysis simulation method for coal comprises the following steps:

s1, processing a coal sample into a cylinder, arranging a plurality of holes on the cylinder as shown in figures 6-7, and uniformly coating propping agents on the edges of the holes;

s2, mounting the processed coal sample on a sample carrier 31, and placing a thermocouple temperature sensor 40 into a hole which is processed in advance by the coal sample; mounting a shaft pressing head 29 and sealing by using a sealing ring 38;

s3, a pyrophyllite powder/salt ring 35 is arranged between the pressure chamber cylinder 32 and the sample carrier 31, confining pressure loading medium NaCl is filled, compaction is carried out in the filling process, pyrophyllite powder is filled at a position exceeding a lower pressure head, filling is stopped when the pyrophyllite powder/salt ring 35 is filled to a position with a vertical height higher than the bottom surface of the shaft pressure head 39, and the confining pressure head 30 and the heating electric furnace 36 are installed after filling is completed;

s4, connecting a pipeline of the high-temperature high-pressure air supply module to an outlet of a conduit above the distributor 33, and connecting a conduit at the bottom of the porous guide plate 34 with an inlet of the product regulation and separation module;

s5, controlling the shaft pressing head 29 and the confining pressure head 30 to alternately press the coal sample step by step in sequence through a servo control module, and finally achieving preset axial confining pressure;

s6, opening a first high-pressure needle valve 7, introducing high-pressure nitrogen in the gas busbar 2 into the pyrolysis reactor 20, evacuating air in the pyrolysis reactor 20, preventing the coal sample from oxidizing combustion in the heating process, closing a second stop valve 41, and loading a catalyst in the catalytic fluidized bed reactor 46;

s7, starting an electric heating furnace 36 to heat the coal sample, and directly pyrolyzing the coal sample if the coal sample is a small-size sample;

if the sample is a large-size sample, opening a first stop valve 7, and injecting a high-temperature high-pressure heat carrier into the coal sample for pyrolysis;

s8, after pyrolysis is finished, a first stop valve 41 is opened, a first high-pressure needle valve 2 is opened to enable a gas busbar 2 to be purged with high-temperature nitrogen, pyrolysis gas enters a catalytic fluidized bed reactor 46 to be regulated and controlled, liquid tar is collected into a tar collecting bottle 49 sequentially through a condenser 47 and a gas-liquid separator 48, residual gas products enter a gas separator 50, the second high-pressure needle valve 5 is opened to enable pyrolysis hydrocarbon gas to flow back and strengthen pyrolysis, the residual product gas passes through a drying pipe 51 and a third mass flowmeter 52 and then enters a gas stove 54 through a three-way valve 53, when the gas stove 54 can ignite the gas, the channel of the three-way valve 53 is changed to enable the gas products to enter the gas collecting bottle 55;

s9, sequentially closing the second stop valve 41, stopping the condenser 47, closing the first high-pressure needle valve 3 and the first stop valve 7, closing the electric heating furnace 36, closing the water cooling sleeve 37 when the temperature is waited to be reduced to the detachable temperature, unloading the shaft pressing head 29 and the confining pressure head 30 and removing the rest parts when the axial and confining pressure stresses are reduced to normal pressure, and preparing for the next test.

The coal samples have different height-diameter ratios of phi 200-400 mm, phi 150-200 mm, phi 50-100 mm and the like, and the phi 50-100 mm samples need to be drilled into pore channels with the length of 60mm and the diameter of 6mm at the center by using a drilling machine; a 200 x 400mm sample was drilled with 4 channels 270mm long and 8mm in diameter directly at the center and 100mm from the center using a drill.

The coal sample can be obtained by cutting lump coal; and meanwhile, crushed coal, pulverized coal, red mud, an adhesive and a wetting agent are selected, and the mixture is compressed and molded by a briquetting machine, wherein the adhesive is one or more of hydroxypropyl methylcellulose (HPMC), sodium carboxymethylcellulose (CMC-Na) and povidone (PVP), and the wetting agent is water or ethanol.

Example 3

As shown in fig. 4-5, taking a coal sample with phi 50 x 100mm as an example, simulating underground pyrolysis at a buried depth of 500mm, taking a side pressure coefficient of 1.2, taking a temperature of 600 ℃, and testing the following steps:

a pore canal with the length of 60mm and the diameter of 6mm is arranged in the center of the coal sample; and a positioning hole with the diameter of 5mm and the length of 5mm is processed at the center of the lower end surface of the coal sample.

Positioning through the positioning holes, installing a coal sample into the sample carrier 31, and then installing the sample carrier 31 on the pressure chamber base 28; positioning thermocouple temperature sensor 40 into the hole of the coal sample; mounting a shaft pressing head 29 and a confining pressing head 30, sealing by using a sealing ring 38, and then mounting a pressure chamber cylinder 32;

a pyrophyllite powder/salt ring 35 is arranged between the pressure chamber cylinder 32 and the sample carrier 31, the confining pressure loading medium NaCl is filled, compaction is carried out in the filling process, the pyrophyllite powder is filled at a position exceeding the lower pressure head, the filling is stopped when the pyrophyllite powder/salt ring 35 is filled to a position with the vertical height higher than the bottom surface of the shaft pressure head 39, and the confining pressure head 30 and the heating electric furnace 36 are installed after the filling is completed;

connecting the high-temperature high-pressure air supply module pipeline to the outlet of the conduit above the distributor 33, and connecting the conduit at the bottom of the porous guide plate 34 with the inlet of the product regulation and separation module;

the servo control module controls the shaft pressing head 29 and the confining pressure head 30 to alternately press the coal sample step by step in sequence, the shaft pressure is initially set to be 10MPa, the confining pressure is set to be 12MPa, and the preset axial confining pressure is finally achieved;

opening a first high-pressure needle valve 7, introducing 3MPa nitrogen in the gas busbar 2 into the pyrolysis reactor 20 at a flow rate of 500ml/min, closing the gas busbar 2 when the second mass flowmeter 45 and the third mass flowmeter 54 are the same as the first mass flowmeter 4 in flow rate, simultaneously closing the first high-pressure needle valve 7 and the second stop valve 41, evacuating air in the pyrolysis reactor 20, preventing the coal sample from oxidizing combustion in the heating process, closing the second stop valve 41, and filling a catalyst in the catalytic fluidized bed reactor 46;

starting a steam generator 1, wherein the equivalent of cold water is 10ml/min, when the steam temperature is 500 ℃, the steam pressure is 3Mpa, starting a first stop valve 7, injecting high-temperature high-pressure steam into a coal sample, and performing steam pyrolysis; simultaneously, the electric heating furnace 36 is started, the temperature rising rate is 10 ℃/min according to the setting of 500 ℃, and the temperature rising is synchronous.

After 3 hours, a second stop valve 41 is opened, the heating temperature of the first pipeline heater 10 and the second pipeline heater 42 is set to 400 ℃, a first high-pressure needle valve 2 is opened to enable a gas busbar 2 to be purged with high-temperature nitrogen, pyrolysis gas enters a catalytic fluidized bed reactor 46 to be regulated and controlled, liquid tar is collected into a tar collecting bottle 49 sequentially through a condenser 47 and a gas-liquid separator 48, residual gas products enter a gas separator 50, the second high-pressure needle valve 5 is opened to enable pyrolysis hydrocarbon gas to flow back and strengthen pyrolysis, the residual product gases enter a gas stove 54 through a three-way valve 53 after passing through a drying pipe 51 and a third mass flowmeter 52, when the gas stove 54 can ignite the gases, the channel of the three-way valve 53 is changed to enable the gas products to enter the gas collecting bottle 55, when the flow rates of the first mass flowmeter 4 and the third mass flowmeter 52 are the same, the channel of the three-way valve 53 is changed to enable the product gases to enter the gas stove 54, when the gas stove 54 cannot ignite, the product collection is ensured to be complete, and the test is ended;

the second stop valve 41 is closed, the condenser 47 is stopped, the first high-pressure needle valve 3 and the first stop valve 7 are closed, the electric heating furnace 36 is closed, the water cooling jacket 37 is closed when the temperature is waited to drop to the detachable temperature, the shaft pressing head 29 and the confining pressure head 30 are unloaded, and the rest parts are removed when the axial and confining pressure stresses are 0MPa, so that the next test is prepared.

Example 4

As shown in fig. 8, the same structure as that of the pyrolysis reactor 20 in embodiment 1 is different in that two pipes are provided above the distributor 33, and no pipe is provided below the porous deflector 37, and in this embodiment, either one of the two pipes above the distributor 33 may serve as an air inlet, and the other one as an air outlet.

It will be appreciated by those skilled in the art that the present utility model can be carried out in other embodiments without departing from the spirit or essential characteristics thereof. Accordingly, the above disclosed embodiments are illustrative in all respects, and not exclusive. All changes that come within the scope of the utility model or equivalents thereto are intended to be embraced therein.

Finally, it should be noted that: the above embodiments are only for illustrating the technical aspects of the present utility model and not for limiting the same, and although the present utility model has been described in detail with reference to the above embodiments, it should be understood by those of ordinary skill in the art that: modifications and equivalents may be made to the specific embodiments of the utility model without departing from the spirit and scope of the utility model, which is intended to be covered by the claims.

Claims

1. The underground in-situ pyrolysis simulation system for the coal is characterized by comprising a high-temperature high-pressure air supply module, a coal in-situ pyrolysis module, a servo control module and a product regulation and separation module;

the high-temperature high-pressure gas supply module is used for providing a high-temperature high-pressure heat carrier for the coal in-situ pyrolysis module, wherein the heat carrier is steam, inert gas, reducing gas or low-concentration oxygen-containing gas;

the coal in-situ pyrolysis module is used for pyrolyzing a coal sample by utilizing the high-temperature high-pressure heat carrier provided by the high-temperature high-pressure air supply module and producing pyrolysis products;

2. The underground in-situ pyrolysis simulation system for coal according to claim 1, wherein the high-temperature high-pressure gas supply module comprises a steam generator (1), a gas busbar (2), a first high-pressure needle valve (3) and a gas heater (6);

the in-situ coal pyrolysis module comprises a first pipeline heater (10), a second pipeline heater (42) and a pyrolysis reactor (20);

the servo control module comprises a data sensor, a data acquisition system (61) and an automation control console (62), wherein the data sensor comprises a first mass flowmeter (4), a first temperature sensor (8), a first pressure sensor (9), a thermocouple temperature sensor (40), a second mass flowmeter (45), a second temperature sensor (43), a second pressure sensor (44) and a third mass flowmeter (52), the data acquisition system (61) is used for acquiring monitoring data of each sensor in real time, and the automation control console (62) is used for acquiring the monitoring data of each sensor according to the data acquisition system (61) and controlling the pyrolysis and product separation processes of coal samples;

the product regulation and separation module comprises a catalytic fluidized bed reactor (46), a condenser (47), a gas-liquid separator (48), a tar collecting bottle (49), a gas separator (50), a drying pipe (51), a three-way valve (53), a gas stove (54), a gas collecting bottle (55) and a second high-pressure needle valve (5);

the steam generator (1) output port is connected with a first input port of a first mass flowmeter (4), a second input port of the first mass flowmeter (4) is connected with an output port of a gas busbar (2), the output port of the first mass flowmeter (4) is connected with a first input port of a gas heater (6), the output port of the gas heater (6) is connected with an input port of a first pipeline heater (10) through a first stop valve (7), a first temperature sensor (8) and a first pressure sensor (9) are arranged between the first stop valve (7) and the first pipeline heater, the output port of the first pipeline heater (10) is connected with an input port of a pyrolysis reactor (20), and the output port of the pyrolysis reactor (20) is connected with an input port of a second pipeline heater (42) through a second stop valve (41);

the output port of the second pipeline heater (42) is connected with the input port of the second mass flowmeter (45), a second temperature sensor (43) and a second pressure sensor (44) are arranged between the second pipeline heater (42) and the second mass flowmeter (45), the output port of the second mass flowmeter (45) is connected with the input port of the catalytic fluidized bed reactor (46), the output port of the catalytic fluidized bed reactor (46) is connected with the input port of the condenser (47), the output port of the condenser (47) is connected with the input port of the gas-liquid separator (48), the liquid output port of the gas-liquid separator (48) is connected with the tar collecting bottle (49), the gas output port of the gas-liquid separator (48) is connected with the input port of the gas separator (50), and the first gas outlet of the gas separator (50) is connected with the second input port of the gas heater (6) through the second high-pressure needle valve (5);

the gas separator (50) second gas outlet links to each other with drying tube (51) input port, drying tube (51) delivery outlet links to each other with third mass flowmeter (52) input port, third mass flowmeter (52) delivery outlet links to each other with tee bend valve (53) input port, tee bend valve (53) first delivery outlet links to each other with gas-cooker (54), tee bend valve (53) second delivery outlet links to each other with gas collecting bottle (55), first mass flowmeter (4), first temperature sensor (8), first pressure sensor (9), second mass flowmeter (45), second temperature sensor (43), second pressure sensor (44), third mass flowmeter (52) and pyrolysis reactor (20) signal output part link to each other with data acquisition system (61) signal input part, data acquisition system (61) signal output part links to each other with automation control platform (62) signal input part, automation control platform (62) signal output part links to each other with pyrolysis reactor (20) signal input part.

3. The underground in-situ pyrolysis simulation system for coal according to claim 2, wherein the pyrolysis reactor (20) comprises a hydraulic machine, a pressure chamber, a servo valve and a heating electric furnace, wherein the pressure chamber is arranged in the hydraulic machine, an electric heating furnace (36) is arranged outside the hydraulic machine, and the servo valve (25) is arranged at the top of the hydraulic machine;

the hydraulic press comprises a main machine base (21), a main machine frame (22), a supporting beam (23), a hydraulic cylinder (24), a pressure transmission column (26), a pressure plate (27), a shaft pressure head (29), pyrophyllite powder/salt rings (35), a confining pressure head (30) and a guide rail (39);

the pressure chamber comprises a pressure chamber base (28), a sample carrier (31), a pressure chamber cylinder (32), a distributor (33), a porous guide plate (34), a thermocouple temperature sensor (40), a sealing ring (38) and a water cooling sleeve (37).

4. The underground in-situ pyrolysis simulation system for coal according to claim 3, wherein a host frame (22) is arranged above the host base (21), a supporting beam (23) is arranged at the top of the host frame (22), a hydraulic cylinder (24) is arranged in the middle of the supporting beam (23), a servo valve (25) is arranged above the hydraulic cylinder (24), a pressure transmission column (26) is arranged below the hydraulic cylinder (24), a pressure plate (27) is arranged below the pressure transmission column (26), a shaft pressure head (29) is arranged below the pressure plate (27), two sides of the shaft pressure head (29) are provided with a confining pressure head (30), a distributor (33) is arranged below the shaft pressure head (29), a guide pipe is arranged above the distributor (33), the guide pipe is connected with a high-temperature high-pressure air supply module, a plurality of guide pipes are arranged below the guide pipe to serve as air outlets, a guide rail (39) is arranged in the host base (21), a pressure chamber base (28) is arranged above the guide rail (39), a salt powder cylinder (35) is arranged below the pressure chamber base (28), a salt powder cylinder (35) is formed by coaxially arranging two cylinders (35) from the diameter of the lower side of the cylinder to the cylinder body (35), the inside is equipped with sample carrier (31), the pressure chamber barrel outside is equipped with electric heating furnace (36), electric heating furnace (36) are equipped with water cooling jacket (37) from top to bottom, cylinder terminal surface is equipped with porous guide plate (34) on pressure chamber base (28), porous guide plate (34) below is equipped with the pipe and is used for the exhaust gas, porous guide plate (34) top is equipped with thermocouple temperature sensor (40), porous guide plate (34) below and distributor (top are equipped with sealing washer (38).

5. A coal underground in-situ pyrolysis simulation system according to claim 3, wherein the porous guide plate (34) is in the shape of a cake, and a plurality of round holes are formed in the upper round surface and the lower round surface.

6. A coal underground in-situ pyrolysis simulation system according to claim 3, wherein the upper part of the distributor (33) is in a shape of a round cake, a round hole is formed in the top of the round cake, a plurality of vertical hollow cylinders are arranged below the round cake, a plurality of round holes are formed in the surfaces of the plurality of hollow cylinders, and a static mixer is arranged inside the plurality of hollow cylinders.

7. A coal underground in-situ pyrolysis simulation system according to claim 3, wherein a visual window is arranged on the pressure chamber for directly observing pyrolysis of the internal coal sample on the surface of the pressure chamber.

8. A coal underground in situ pyrolysis simulation system according to claim 3 wherein the hydraulic press has a maximum pressure of 1000KN and a shaft pressure confining pressure of at most 20Mpa.

9. A coal underground in situ pyrolysis simulation system according to claim 2, wherein the rated temperature of the first (10) and second (42) pipeline heaters is greater than 360 ℃.