阅读说明：本技术 一种室内土壤火烧模拟试验装置及其试验方法 (Indoor soil fire simulation test device and test method thereof ) 是由 梅雪峰 金涛 胡卸文 贺旭荣 黄光林 郑锐杰 薛松 赵立明 王严 杨瀛 曹希超 于 2021-01-27 设计创作，主要内容包括：一种室内土壤火烧模拟试验装置及其试验方法,电阻炉内设有风扇和温度传感器,电阻炉底板开口上有网筛,电阻炉放置在三角支座上面,机箱放置在三角支座下方,机箱内放置试验土芯。该机箱由两个半圆筒经合页连接组成为一个圆筒,圆筒内壁面衬有石棉隔热层,每个半圆筒上都有竖向矩形开口和设有标尺以及设有多个水平矩形开口,底盘与圆筒滑动配合,且底盘上两根螺栓分别从两个竖向矩形开口中伸出,并经螺母固定。温度、湿度传感器从每一水平矩形开口伸入试验土芯之中。本发明可在室内进行不同火烧温度和持续时间的原状土壤火烧试验,并可实时测量土芯内不同深度土壤在焙烧过程中温度和含水率的变化,具有试验测量方便,便于携带的特点。(A fan and a temperature sensor are arranged in a resistance furnace, a mesh screen is arranged on an opening of a bottom plate of the resistance furnace, the resistance furnace is placed on a triangular support, a case is placed below the triangular support, and a test soil core is placed in the case. The chassis is in sliding fit with the cylinder, and two bolts on the chassis respectively extend out of the two vertical rectangular openings and are fixed through nuts. The temperature and humidity sensors extend into the test soil core from each horizontal rectangular opening. The invention can carry out undisturbed soil fire tests with different fire temperatures and durations indoors, can measure the change of the temperature and the water content of the soil with different depths in the soil core in the roasting process in real time, and has the characteristics of convenient test and measurement and convenient carrying.)

1. An indoor soil fire simulation test device comprises a controller (39) and is characterized in that,

the structure of the resistance furnace (31) is as follows: the ceramic shell (36) is in a cylindrical shape with a sealed top and an opening on the bottom plate, the opening on the bottom plate is covered and fixed with a stainless steel mesh screen (32), a coiled resistance wire (33) is arranged on the mesh screen, a resistance furnace temperature sensor probe (34) is arranged at the central position of the resistance wire (33), a heat exhausting fan (35) is arranged at the top in the ceramic shell (36), and the resistance wire (33), the resistance furnace temperature sensor probe (34) and the heat exhausting fan (35) are respectively connected to the controller (39) through leads (38);

the triangular support (21) is formed by fixing three oblique support legs at the lower part of a circular ring; the resistance furnace (31) is placed on the triangular support (21), and the diameter of the bottom plate of the ceramic shell of the resistance furnace is slightly larger than the outer diameter of a circular ring at the top of the triangular support;

the structure of a case (11) used for containing the test soil core (18) is as follows: one side of two identical semi-cylinders is connected by at least two hinges (16), the other side is connected by a lock catch (17), asbestos heat-insulating layers (14) are fixed on the inner walls of the two semi-cylinders, vertical preset rectangular openings (13) are formed in the two semi-cylinders, the central lines of the two vertical preset rectangular openings (13) are coplanar with the axial line of the whole cylinder, an adjustable chassis (15) is positioned in the cylinder and is in sliding fit with the inner wall of the cylinder, the inner ends of two outward extending screws (151) are fixed on the side surface of the adjustable chassis (15), the outer ends of the two outward extending screws respectively extend out of the two vertical preset rectangular openings (13) and are fixed by adjusting nuts (152), a scale (131) is arranged at the position of the vertical preset rectangular opening (13) on one or two semi-cylinders, a plurality of horizontal preset rectangular openings (12) are arranged on the upper semi-cylinder according to a certain vertical, a temperature sensor probe (121) and a humidity sensor probe (122) extend into the center of a test soil core (18) arranged in the machine box cylinder through each horizontal preset rectangular opening (12);

the temperature sensor probe (121) and the humidity sensor probe (122) are respectively connected with the controller (39) through leads, and the case (11) is placed below the triangular support (21).

2. The indoor soil fire simulation test device according to claim 1, wherein the opening diameter of the bottom plate of the ceramic shell (36) of the resistance furnace is not larger than the inner diameter of the top ring of the triangular support (21), and the inner diameter of the cylinder of the case (11) is slightly smaller than the inner diameter of the top ring of the triangular support (21).

3. An indoor soil fire simulation test device according to claim 1, wherein the lock catch (17) is structured as: all be fixed with the otic placode on the opposite side of two semicylinders of machine case, fixed screw post (171) on the otic placode, porose (172) on the other otic placode, two semicylinders fold the back, and the screw post passes hole (172) and fixes through nut (173).

4. An indoor soil fire simulation test device as claimed in claim 1, wherein a hollow handle (37) is fixed on a ceramic shell (36) of the resistance furnace, the outer ends of a plurality of wires (38) are connected with the controller (39), and the inner ends of the wires penetrate through the inner cavity of the handle and are connected with a resistance wire, a temperature sensor probe of the resistance furnace and a heat exhausting fan in the ceramic shell.

5. An indoor soil fire simulation test device as claimed in claim 1, wherein the height of the cylinder of the case (11) is slightly lower than that of the triangular support (21).

6. An indoor soil fire simulation test device as claimed in claim 1, wherein the controller (39) is further provided with a display for displaying the temperature of the resistance furnace and the test soil core in real time and displaying the humidity of the test soil core.

7. A test method using the burning simulation test device as defined in any one of claims 1 to 6, comprising the steps of:

s1, field sampling: using a cutting ring with the inner diameter and the height slightly smaller than the inner cavity of the machine case cylinder to obtain a standard undisturbed soil sample in the field, namely a test soil core;

s2, opening a case lock catch, putting the well-taken field cylindrical test soil core into the case, putting the adjustable chassis at the bottom of the test soil core in the case cylinder, folding the case and fixing the case by the lock catch; rotating the adjusting nut to loosen the adjustable chassis, and then moving the adjustable chassis to enable the upper surface of the soil core to be flush with the upper end surface of the chassis cylinder; putting a temperature sensor, a humidity sensor and the like into a horizontal preset rectangular opening of a case according to a certain distance and depth requirements, and detecting the readiness of a system;

s3, placing the triangular support on the upper part of the case, then placing a high-temperature resistance furnace heated to a preset experiment temperature on the triangular support, starting a fan to heat and bake the upper surface of the soil core, preparing a burning simulation system, and starting timing a soil burning simulation experiment;

s4, in the test process, measuring the temperature and the moisture content change in the soil body burning process through a temperature sensor and a humidity sensor;

s5, burning until the preset test time, closing the high-temperature resistance furnace, naturally cooling the soil core, and dismantling the equipment;

s6, rotating the adjusting nut to enable the adjustable chassis to be connected with the case loosely, dragging the adjustable chassis to enable the soil body to move upwards, and cutting soil samples with corresponding depths from the upper part of the case corresponding to the scale marks of the scale to perform geotechnical tests;

s7, changing the heating temperature and the heating duration of the high-temperature resistance furnace, and repeating (S1-S6) to study the change of the soil property under different surface firing temperatures and different firing durations.

Technical Field

The invention relates to the technical field of testing of post-fire debris flow disaster mechanism and prevention and control research, in particular to an indoor soil fire simulation test device and a test method thereof.

Background

After forest fire occurs in mountainous areas, the post-fire debris flow which is different from the traditional debris flow occurs at a very high probability near a burn area. Compared with the non-fired debris flow, the source starting is obviously different, and the change of physical properties, water physical properties and the like of the soil under the forest caused by high-temperature roasting in the forest fire combustion process is closely related. Because the uncertainty of forest fire ignition time, place, fire passing temperature and fire passing duration in mountain areas causes difficulty in research on the aspect, the forest fire ignition test planning cost is high, the fire burning range is not easy to control, and the forest fire inhibition makes the existing field test means basically difficult to implement, so that the research on the indoor soil fire burning simulation experiment for changing the soil property by forest fire is particularly important. However, at present, the existing indoor soil fire simulation test device still has some defects:

one of them, present fire analogue test device is mostly remolded soil fire test device, and the soil body disturbance is great, and the error is great.

Secondly, the existing burning simulation test device is difficult to realize the controllable experimental study of burning temperature and burning time.

Thirdly, the existing burning simulation test device is difficult to monitor the temperature and the moisture content change of soil at different depths in the burning process in real time.

Fourthly, the existing burning simulation test device is difficult to accurately obtain soil samples with different depths after burning.

Disclosure of Invention

The invention aims to provide an indoor soil burning simulation test device which is convenient to install, use and measure and can be properly disassembled, and aims to measure the change conditions of the temperature and the water content of soil with different temperatures in the roasting process in real time by performing soil burning tests with different burning temperatures and duration indoors.

The purpose of the invention is realized as follows: an indoor soil burning simulation test device comprises a controller,

the resistance furnace structure is: the ceramic shell is in a cylindrical shape with a top seal and a hole on the bottom plate, the hole on the bottom plate is covered and fixed with a stainless steel mesh screen, a coiled resistance wire is arranged on the mesh screen, a probe of a resistance furnace temperature sensor is arranged at the center of the resistance wire, the top in the ceramic shell is provided with a heat exhausting fan, and the resistance wire, the probe of the resistance furnace temperature sensor and the heat exhausting fan are respectively connected to the controller through leads;

the triangular support is formed by fixing three oblique support legs at the lower part of a circular ring; the resistance furnace is placed on the triangular support, and the diameter of a bottom plate of a ceramic shell of the resistance furnace is slightly larger than the outer diameter of a circular ring at the top of the triangular support;

a quick-witted case structure for splendid attire experimental soil core does: one side of each of the two identical semi-cylinders is connected by at least two hinges, the other side of each of the two identical semi-cylinders is connected by a lock catch, asbestos heat insulation layers are fixed on the inner walls of the two semi-cylinders, vertical preset rectangular openings are formed in the two semi-cylinders, the central lines of the two vertical preset rectangular openings are coplanar with the axial line of the whole cylinder, the adjustable chassis is positioned in the cylinder and is in sliding fit with the inner wall of the cylinder, the inner ends of the two overhanging screws are fixed on the side surface of the adjustable chassis, the outer ends of the two overhanging screws respectively extend outwards from the two vertical preset rectangular openings and are fixed by the adjusting nuts, a ruler is arranged at the position, close to the vertical preset rectangular opening, of one or two semicircular cylinders, a plurality of horizontal preset rectangular openings are arranged on the upper semicircular cylinder at certain vertical intervals, and the temperature sensor probe and the humidity sensor probe extend into the center position of the test soil core arranged in the chassis cylinder through each horizontal preset rectangular opening;

the temperature sensor probe and the humidity sensor probe are respectively connected with the controller through leads, and the case is placed below the triangular support.

The diameter of the opening of the bottom plate of the ceramic shell of the resistance furnace is not more than the inner diameter of the circular ring at the top of the triangular support, and the inner diameter of the cylinder of the case is slightly less than the inner diameter of the circular ring at the top of the triangular support.

The lock catch structure is as follows: all be fixed with the otic placode on the opposite side of two semicircles of machine case, fixed screw post on the otic placode, porose on the otic placode of another, two semicircles fold the back, and the screw post passes the hole and fixes through the nut.

A hollow handle is fixed on a ceramic shell of the resistance furnace, the outer ends of a plurality of wires are connected with the controller, and the inner ends of the wires penetrate through an inner cavity of the handle to be connected with a resistance wire, a temperature sensor probe of the resistance furnace and a heat exhausting fan in the ceramic shell.

The height of the case cylinder is slightly lower than that of the triangular support.

The controller is also provided with a display which displays the temperature of the resistance furnace and the test soil core in real time and the humidity of the test soil core.

The invention also aims to provide a test method of the burning simulation test device.

Another object of the invention is achieved by: the test method comprises the following steps:

s1, field sampling: using a cutting ring with the inner diameter and the height slightly smaller than the inner cavity of the machine case cylinder to obtain a standard undisturbed soil sample in the field, namely a test soil core;

s2, opening a case lock catch, putting the well-taken field cylindrical test soil core into the case, putting the adjustable chassis at the bottom of the test soil core in the case cylinder, folding the case and fixing the case by the lock catch; rotating the adjusting nut to loosen the adjustable chassis, and then moving the adjustable chassis to enable the upper surface of the soil core to be flush with the upper end surface of the chassis cylinder; putting a temperature sensor, a humidity sensor and the like into a horizontal preset rectangular opening of a case according to a certain distance and depth requirements, and detecting the readiness of a system;

s3, placing the triangular support on the upper part of the case, then placing a high-temperature resistance furnace heated to a preset experiment temperature on the triangular support, starting a fan to heat and bake the upper surface of the soil core, preparing a burning simulation system, and starting timing a soil burning simulation experiment;

s4, in the test process, measuring the temperature and the moisture content change in the soil body burning process through a temperature sensor and a humidity sensor;

s5, burning until the preset test time, closing the high-temperature resistance furnace, naturally cooling the soil core, and dismantling the equipment;

s6, rotating the adjusting nut to enable the adjustable chassis to be connected with the case loosely, dragging the adjustable chassis to enable the soil body to move upwards, and cutting soil samples with corresponding depths from the upper part of the case corresponding to the scale marks of the scale to perform geotechnical tests;

s7, changing the heating temperature and the heating duration of the high-temperature resistance furnace, and repeating (S1-S6) to study the change of the soil property under different surface firing temperatures and different firing durations.

Compared with the prior art, the invention has the beneficial effects that: the device is convenient to install, use and measure, can carry out soil burning tests with different burning temperatures and duration indoors while ensuring the minimum disturbance of the undisturbed soil structure, and can measure the temperature and water content change conditions of soil with different depths in the burning process in real time; fresh baked soil samples with different depths can be obtained in time after the burning test, and the samples are used for testing other physical, mechanical and hydrological property indexes of baked soil in an indoor soil test; the corresponding parts can be properly disassembled, and the device is convenient to carry and has high popularization value in the aspects of disaster mechanism and prevention and treatment research of the debris flow after fire.

Drawings

FIG. 1 is a schematic front view of the testing apparatus of the present invention;

FIG. 2 is a schematic top view of the structure of FIG. 1;

FIG. 3 is a schematic view of the detection system of the present invention;

FIG. 4 is a schematic structural view of a support structure system of the present invention;

FIG. 5 is a schematic structural diagram of a fire simulation system according to the present invention;

fig. 6 is a schematic structural diagram of a latch in the detection system shown in fig. 3.

Detailed Description

The embodiments of the present invention will be further explained with reference to the drawings, wherein the reference numerals are defined as follows:

11: (cylindrical) casing, 12: horizontal preset rectangular opening, 121: temperature sensor probe, 122: humidity sensor probe, 13: vertical preset rectangular opening (downward through the semi-cylinder or not), 131: scale, 14: asbestos insulation layer, 15: adjustable chassis, 151: overhanging screw, 152: adjusting nut, 16: hinge, 17: a lock catch and a locking part 171: (left plate of latch, left ear plate) screw post, 172: (locking buckle right piece is right ear plate) screw hole, 173: (tightening) nut, 18: test soil core, 21: tripod rest, 31: (high temperature) resistance furnace, 32: stainless steel mesh screen, 33: (high temperature) resistance wire, 34: resistance furnace temperature sensor probe, 35: heat exhausting fan, 36: (high-temperature resistance furnace) ceramic case, 37: handle, 38: wire (including high temperature resistance wire, temperature sensor, the circular telegram wire of heat extraction fan), 39: and the controller (comprises a resistance wire temperature detection and control device, a fan start-stop device, a test soil core temperature and humidity detection and control device and a display).

As shown in fig. 1 and 2, the present invention mainly includes a detection system, a support structure system and a fire simulation system, which are sequentially arranged from bottom to top.

The utility model provides an indoor soil fever analogue test device, resistance furnace 31 structure is: the ceramic shell 36 is in a cylindrical shape with a top sealed and a bottom plate provided with an opening, the opening of the bottom plate is covered and fixed with a stainless steel mesh screen 32, a coiled resistance wire 33 is arranged on the mesh screen, a resistance furnace temperature sensor probe 34 is arranged at the center of the resistance wire 33, a heat exhausting fan 35 is arranged at the top in the ceramic shell 36, and the resistance wire 33, the resistance furnace temperature sensor probe 34 and the heat exhausting fan 35 are respectively connected to the controller 39 through leads 38;

the triangular support 21 is formed by fixing three oblique support legs at the lower part of a circular ring; the resistance furnace 31 is placed on the triangular support 21, and the diameter of the bottom plate of the ceramic shell of the resistance furnace is slightly larger than the outer diameter of the circular ring at the top of the triangular support;

the structure of the case 11 for containing the test soil core 18 is as follows: one side of two identical semi-cylinders is connected by at least two hinges 16, the other side is connected by a lock catch 17, asbestos heat insulation layers 14 are fixed on the inner walls of the two semi-cylinders, vertical preset rectangular openings 13 are formed in the two semi-cylinders, the central lines of the two vertical preset rectangular openings 13 are coplanar with the axial line of the whole cylinder, an adjustable chassis 15 is positioned in the cylinder and is in sliding fit with the inner wall of the cylinder, the inner ends of two extending screws 151 are fixed on the side surface of the adjustable chassis 15, the outer ends of the two extending screws respectively extend outwards from the two vertical preset rectangular openings 13 and are fixed through adjusting nuts 152, a scale 131 is arranged at the position, close to the vertical preset rectangular openings 13, of one semi-cylinder or the two semi-cylinders, a plurality of horizontal preset rectangular openings 12 are arranged on the upper semi-cylinder according to a certain vertical distance, and a temperature sensor probe 121 and a humidity sensor probe 122 extend into the central position of a built-in a soil core (ii) a

The temperature sensor probe 121 and the humidity sensor probe 122 are respectively connected to the controller 39 through wires, and the case 11 is placed under the triangular support 21.

A hollow handle 37 is fixed on a ceramic shell 36 of the resistance furnace, the outer ends of a plurality of wires 38 are connected with a controller 39, and the inner ends of the wires penetrate through the inner cavity of the handle to be connected with a resistance wire, a temperature sensor probe of the resistance furnace and a heat exhausting fan in the ceramic shell.

The ceramic shell is a cylindrical enclosure having a top plate and a bottom plate with openings (i.e., openings) in the bottom plate, see fig. 3, where the vertical centerlines of the two vertically preset rectangular openings are parallel and coplanar with the axis of the entire cylinder.

The diameter of the opening of the bottom plate of the ceramic shell 36 of the resistance furnace is not more than the inner diameter of the top ring of the triangular support 21, and the inner diameter of the cylinder of the case 11 is slightly less than the inner diameter of the top ring of the triangular support 21.

Referring to fig. 3 and 6, the latch 17 has the following structure: all be fixed with the otic placode on the opposite side of two semicylinders of machine case, fixed screw 171 on the otic placode, porose 172 on the otic placode of another, two semicylinders fold the back, and the screw passes hole 172 and fixes through nut 173. The left screw stud 171 of the latch passes through the right hole 172 of the latch and then the left and right pieces (i.e. the left and right ear plates) are connected and fixed by the screwed nut 173, so that the folding and fixing of the cylindrical case are realized. The case 11 is formed by connecting two half cylinders without bottoms and covers through hinges, and a horizontal preset rectangular opening 12 is arranged on the side surface of each half cylinder at a certain vertical interval along the circumferential direction so as to be convenient for inserting a probe of a temperature and humidity sensor. Two vertical preset rectangular openings 13 (preferably located in the middle of the wall of each semi-cylindrical barrel) which are symmetrically distributed are formed in the side face of each semi-cylindrical barrel, a channel is provided for the outward extending screw 151 to move along with the adjustment nut 152 when the adjustable chassis 15 is moved, and a scale 131 is arranged beside each vertical preset rectangular opening 13, so that the soil with the corresponding depth can be accurately cut after the burning test. The inner wall of the cylindrical case 11 is provided with a cylindrical asbestos heat insulation layer 14 distributed along the inner wall. The cylindrical case 11 is internally provided with a cylindrical test soil core 18, the upper surface of the test soil core is flush with the upper edge of the cylindrical case, and a probe of the sensor is inserted into the test soil core 18. The sensors in the detection system include a temperature sensor 121 and a humidity sensor 122. The probes of the sensor are inserted horizontally along the horizontal preset rectangular openings 12 of different heights on the side surface of the cylindrical case 11 in layers. One temperature sensor probe 121 and one humidity sensor probe 122 are inserted into each horizontal preset rectangular opening 12 and respectively extend into the position close to the axis of the cylindrical case 11.

As shown in fig. 4, the support structure system includes a tripod stand 21. The upper part of the three-leg support is circular, and the diameter of the three-leg support is slightly larger than the outer diameter of the cylindrical case 11 in the detection system and slightly smaller than the outer diameter of the ceramic shell 36 of the high-temperature resistance furnace in the burning simulation system. The vertical height of the tripod support 21 is slightly higher than the height of the cylindrical case 11 for ventilation to ensure sufficient oxygen.

As shown in FIG. 5, the ceramic shell of the high temperature resistance furnace 31 is disc-shaped, the side of the ceramic shell is connected with the ceramic handle 37 to lead out the power line and facilitate movement, the side of the ceramic shell 36 of the high temperature resistance furnace 31 is connected with the ceramic handle 37 to facilitate movement, and a lead 38 is led out and connected with a controller 39 which can adjust the power of the resistance furnace and monitor, control and display the working temperature of the surface of the resistance wire in real time. Wherein the high temperature resistance wire 33 is coiled horizontally at the lower part. The lower surface of the resistance furnace is provided with a stainless steel mesh 32, so that the heat radiation is uniform and the high-temperature resistance wire 33 is prevented from falling off. The temperature sensor probe 34 is arranged at the center of the high-temperature resistance wire 33 and is externally connected with a temperature sensing receiver (arranged in the controller 39). In the test, the power of the high-temperature resistance furnace 31 can be adjusted by the controller 39 to control the surface working temperature of the high-temperature resistance wire 33 so as to carry out the fire test with different preset fire temperatures. (note: the temperature detected by the temperature sensor in the test is the heating temperature of the resistance wire and can be similar to the heating temperature of the surface of the soil core in the test)

The test method of the burning simulation test device comprises the following steps:

s1, field sampling: using a cutting ring with the inner diameter and the height slightly smaller than the inner cavity of the machine case cylinder to obtain a standard undisturbed soil sample in the field, namely a test soil core;

s2, opening a case lock catch, putting the well-taken field cylindrical test soil core into the case, putting the adjustable chassis at the bottom of the test soil core in the case cylinder, folding the case and fixing the case by the lock catch; rotating the adjusting nut to loosen the adjustable chassis, and then moving the adjustable chassis to enable the upper surface of the soil core to be flush with the upper end surface of the chassis cylinder; putting a temperature sensor, a humidity sensor and the like into a horizontal preset rectangular opening of a case according to a certain distance and depth requirements, and detecting the readiness of a system;

s3, placing the triangular support on the upper part of the case, then placing a high-temperature resistance furnace heated to a preset experiment temperature on the triangular support, starting a fan to heat and bake the upper surface of the soil core, preparing a burning simulation system, and starting timing a soil burning simulation experiment;

s4, in the test process, measuring the temperature and the moisture content change in the soil body burning process through a temperature sensor and a humidity sensor;

s5, burning until the preset test time, closing the high-temperature resistance furnace, naturally cooling the soil core, and dismantling the equipment;

s6, rotating the adjusting nut to enable the adjustable chassis to be connected with the case loosely, dragging the adjustable chassis to enable the soil body to move upwards, and cutting soil samples with corresponding depths from the upper part of the case corresponding to the scale marks of the scale to perform geotechnical tests;

s7, changing the heating temperature and the heating duration of the high-temperature resistance furnace, and repeating the steps S1-S6 to study the change of the soil property under different surface firing temperatures and different firing durations.