CN113189137A - Single freezing pipe heat preservation and cold insulation similar model test device and test method under action of ground stress - Google Patents

Abstract

The invention relates to a single freezing pipe heat preservation and cold insulation similar model test device under the action of ground stress, which consists of a horizontal freezing pipe, a self-reaction frame, a congealing machine, a horizontal multistage centrifugal pump machine, a test box body, a lifting hole, a lower pressure-bearing steel plate, a heat preservation material, a sealing disc, a horizontal steel pipe, a TDS (total dissolved solids) thermometer, an oil cylinder, a temperature measuring line, a low-temperature alcohol conveying pipe and a valve; meanwhile, the invention also provides a single freezing pipe heat preservation and cold insulation similar model test method under the action of ground stress, provides a specific embodiment and has a guidance value for related tests in the field in the future. The device not only realizes the test of the heat preservation and cold insulation performance of the material under the action of the ground stress, but also obtains the cold quantity diffusion distribution condition and the cold quantity action range of different soil layer heights along the longitudinal direction of the single freezing pipe, has very important guiding significance for the subsequent extraction of surplus cold quantity of the stratum, and also provides a selection basis for selecting the material with excellent heat preservation and cold insulation performance during the construction of the underground engineering freezing method.

Description

Single freezing pipe heat preservation and cold insulation similar model test device and test method under action of ground stress

Technical Field

The invention relates to the technical field of test and test of heat preservation and cold insulation performance of materials, in particular to a single freezing pipe heat preservation and cold insulation similar model test device and a test method under the action of ground stress.

Background

Due to complex hydrogeological conditions of a deep surface soil layer, when underground engineering, particularly when a freezing method is adopted during shaft construction of a coal mine shaft, a large amount of cold energy is easily diffused to surrounding soil bodies when a freezing pipe passes through an initial surface soil section, so that the surrounding soil bodies are excessively frozen to influence the delay of construction period of subsequent shaft excavation; the forced blasting construction inevitably increases the construction cost. Therefore, a material with excellent heat and cold insulation performance is needed to be adopted for heat and cold insulation of the freezing pipe. However, when the initial surface soil section is insulated by heat and cold by adopting the material, the material is in a compressed state under the action of the ground stress of the soil body. Because the internal structure of the material can change under the compression state, the heat preservation performance of the material is influenced, the research on the heat preservation and cold insulation performance of the material under the action of the earth stress of the soil body has practical significance, and especially the research on the diffusion condition of the cold of the soil layer around the freezing pipe has very important guiding value for the subsequent extraction of the surplus cold of the stratum. At present, the influence of a stress state is mostly not considered when the material heat preservation and cold insulation performance is researched, even if a sleeve is adopted outside a freezing pipe and oil pressure is applied to a closed space to simulate the compression state of the freezing pipe heat preservation material, the test method can only arrange temperature measuring points on the heat preservation material and the freezing pipe, only can obtain the temperature change condition of the freezing pipe in a very small range, not only can not obtain the cold diffusion action range of the freezing pipe, but also can not obtain the temperatures of different soil layer heights along the longitudinal direction of the freezing pipe, and has certain limitation. In order to accurately grasp the cold quantity action range of the freezing pipe in a pressed state and the longitudinal temperature of the soil layer around the freezing pipe, it is necessary to test the heat preservation and cold insulation performance and the cold quantity diffusion condition of the material under the action of the ground stress.

Disclosure of Invention

The invention aims to overcome the defects of the prior art, provides a single freezing pipe heat-preservation and cold-insulation similar model test device and a test method under the action of ground stress, can perform a single freezing pipe heat-preservation and cold-insulation similar model test under the action of ground stress, can obtain the cold energy action range of a single freezing pipe and the temperature distribution conditions of different soil layers in the longitudinal direction of the single freezing pipe, obtain the evaluation index of the heat-preservation and cold-insulation effect of a material under the action of ground stress, and provide important reference for the selection of the heat-preservation and cold-insulation material during the construction of a coal mine shaft freezing method.

In order to achieve the above object, the technical solution of the present invention is as follows:

the single freezing pipe heat-preservation cold-insulation similar model test device under the action of ground stress comprises a horizontal freezing pipe, a self-reaction frame, a freezing machine, a horizontal multistage centrifugal pump machine, a test box body, lifting holes, a lower bearing steel plate, a heat-preservation material, a sealing disc, a horizontal steel pipe, a TDS (total dissolved solids) thermodetector, an oil cylinder, a temperature measuring line, a low-temperature alcohol conveying pipe and a valve, wherein the self-reaction frame is formed by welding nuts, screws, T-shaped steel, a cross-shaped steel beam, a bearing column and an upper bearing steel plate, two circular holes are formed in two sides of the test box body and are welded with the bearing column, the lifting holes are formed in the upper end face of the test box body, the heat-preservation material wraps the outer surface of the horizontal freezing pipe, the freezing machine and the horizontal multistage centrifugal pump machine are respectively provided with a low-temperature alcohol bearable input port and a low-temperature alcohol output port, and the horizontal multistage centrifugal pump machine is low in temperature of-30 ℃, the device comprises a lower pressure-bearing steel plate, a TDS (total dissolved solids) thermometer, a test box body, an oil cylinder, a self-reaction frame, a lower pressure-bearing steel plate, sealing discs, a horizontal steel pipe, an electric oil pump, an oil outlet and an oil inlet, wherein wire outlet holes are formed in two sides of the lower pressure-bearing steel plate, the sealing discs are welded at two ends of the horizontal steel pipe respectively, the horizontal steel pipe is welded at the center of the sealing discs, the TDS thermometer is connected with a temperature measuring point inside the test box body through a temperature measuring line, the oil cylinder is placed between the self-reaction frame and the lower pressure-bearing steel plate, the electric oil pump is used for pressurizing the self-reaction frame, the oil outlet and the oil inlet are formed in the cylinder body, a low-temperature alcohol conveying pipe is made of rubber, and a valve is welded at one end of the horizontal freezing pipe.

Preferably, in the single freezing pipe heat preservation and cold insulation similar model test device under the action of the ground stress, the self-reaction frame and the lower end bearing plate are made of Q235 steel materials.

Preferably, in the single freezing pipe heat preservation and cold insulation similar model test device under the action of the ground stress, the horizontal steel pipe is a seamless steel pipe with the diameter of 140mm, the thickness of 22mm and the length of 600 mm.

Preferably, the invention also provides a single freezing pipe heat preservation and cold insulation similar model test method under the action of ground stress, which comprises the following steps:

the method comprises the following steps: firstly, selecting a horizontal freezing pipe with a proper length by measuring the distance between circular holes on two sides of the test box body, enabling the horizontal freezing pipe to penetrate through the test box body, enabling two ends of the horizontal freezing pipe to be exposed out of the box body by 10cm, then arranging 3 temperature measuring points on a straight line on the upper side of the horizontal freezing pipe, which is parallel to the pipe axis, at equal intervals, respectively arranging 3 temperature measuring lines on the 3 temperature measuring points, fixing the 3 temperature measuring lines on the upper side of the horizontal freezing pipe by using an adhesive tape, then fixing the heat-insulating material on the outer surface of the horizontal freezing pipe, and arranging 3 temperature measuring points on the outer surface of the heat-insulating material in the same way;

step two: arranging a layer of temperature measuring points at intervals of 15cm from the lower side of the horizontal freezing pipe, arranging 3-4 layers in total, arranging 3 temperature measuring points on each layer, arranging 3 temperature measuring points on a straight line parallel to the axis of the horizontal freezing pipe at equal intervals, and arranging 5-6 layers of temperature measuring points on the upper side of the horizontal freezing pipe in the same manner;

step three: when the test box body is filled with soil to the position where the temperature measuring points are buried, burying one end of each temperature measuring line at the position of the temperature measuring point in the second step, filling soil layer by layer from bottom to top and burying the temperature measuring lines, covering the lower pressure-bearing steel plate above the soil body after filling the soil, and enabling the temperature measuring lines to extend out of wire outlet holes of the lower pressure-bearing steel plate;

step four: welding the sealing discs at two ends of the horizontal freezing pipe, welding the horizontal steel pipe at the center of the sealing discs, and connecting the horizontal steel pipe, the congealing machine and the horizontal multistage centrifugal pump together through the low-temperature alcohol delivery pipe to form a circulation loop;

step five: pouring low-temperature alcohol into the congealer and starting a refrigeration mode, then starting the horizontal multistage centrifugal pump, enabling the low-temperature alcohol to continuously circulate through the horizontal freezing pipe, connecting the temperature measuring line extending in the third step to the TDS temperature measuring instrument, detecting whether the temperature measuring line works normally, and closing the instrument after detecting and ensuring the normal work;

step six: firstly, placing the oil cylinder on the lower pressure-bearing steel plate by using a crane, connecting an electric oil pump with an oil inlet and an oil outlet on the oil cylinder through an oil pipe, then applying pressure to a soil body by using the electric oil pump and the oil cylinder, then opening the TDS temperature measuring instrument, and starting temperature monitoring until the test is finished;

step seven: after the test is finished, storing test data on a computer, unloading the pressure of the oil cylinder, closing the TDS thermodetector, and opening a valve on the horizontal freezing pipe to discharge low-temperature alcohol;

step eight: and (3) arranging and analyzing test data, measuring the heat preservation and cold insulation performance of the heat preservation material by taking the temperature of each layer of temperature measurement point and the temperature difference value on the horizontal freezing pipe as a standard, and when the temperature of a certain layer of temperature measurement point is approximately consistent with the room temperature, determining that the distance from the temperature measurement point of the soil layer to the horizontal freezing pipe is the maximum range of the cold quantity action of the freezing pipe when the heat preservation material works.

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

the device uses low-temperature alcohol to continuously circulate in the single freezing pipe for cold diffusion, so that the temperature of the single freezing pipe can be kept consistent with that of the freezing pipe during freezing construction, temperature measuring points are arranged on different soil layers along the longitudinal direction of the freezing pipe, the temperature change conditions at different heights along the longitudinal direction of the single freezing pipe can be monitored, the cold diffusion action range of the single freezing pipe can be obtained, meanwhile, the stress state of the material under the action of ground stress is simulated more truly by applying load on the upper part of a soil body by using the oil cylinder, the test result is closer to the real working condition, the test data is more comprehensive, and an ideal test device and a test method can be provided for selecting the material with excellent heat preservation and cold insulation performance during freezing construction.

Drawings

FIG. 1 is a schematic connection diagram of the present invention.

Fig. 2 is a schematic structural diagram of a patent test chamber according to the invention.

Fig. 3 is a schematic view of the whole structure of the horizontal freezing pipe of the invention.

FIG. 4 is a schematic diagram of a cylinder structure according to the present invention.

FIG. 5 is a schematic structural diagram of the pressure-bearing steel plate of the present invention.

FIG. 6 is a schematic view of the self-reaction frame according to the present invention.

The reference numbers in the figures illustrate: 1-horizontal freezing pipe, 2-self-reaction frame, 3-congealing machine, 4-horizontal multistage centrifugal pump machine, 5-test box body, 6-lifting hole, 7-lower pressure-bearing steel plate, 8-heat-insulating material, 9-sealing disk, 10-horizontal steel pipe, 11-TDS thermodetector, 12-oil cylinder, 13-temperature measuring line, 14-low-temperature alcohol conveying pipe, 15-valve, 16-nut, 17-screw, 18-T-shaped steel, 19-cross steel beam, 20-pressure-bearing column, 21-upper pressure-bearing steel plate, 22-low-temperature alcohol input port, 23-low-temperature alcohol output port, 24-oil outlet, 25-oil inlet

Detailed Description

The invention will be described in further detail with reference to the following drawings and specific embodiments, and it should be understood that the described embodiments are only a part of the embodiments of the invention, and not all 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 the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for convenience of description and simplicity of description, but do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus, should not be construed as limiting the present invention.

In the description of the present invention, the terms "mounted," "connected," and "connected" are to be understood broadly, and may be, for example, fixedly connected, detachably connected, or integrally connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.

Example (b):

the single freezing pipe heat preservation and cold insulation similar model test device under the ground stress effect as shown in figure 1 comprises a material heat preservation and cold insulation performance test device under the ground stress state, and comprises a horizontal freezing pipe 1, a self-reaction frame 2, a freezing machine 3, a horizontal multistage centrifugal pump machine 4, a test box body 5, a lifting hole 6, a lower pressure-bearing steel plate 7, a heat preservation material 8, a sealing disc 9, a horizontal steel pipe 10, a TDS thermodetector 11, an oil cylinder 12, a temperature measuring line 13, a low-temperature alcohol conveying pipe 14 and a valve 15, wherein the self-reaction frame 2 is formed by welding a nut 16, a screw 17, a T-shaped steel 18, a cross steel beam 19, a pressure-bearing column 20 and an upper pressure-bearing steel plate 21, two circular holes are formed in two sides of the test box body 5 and are welded with the pressure-bearing column 20, the lifting hole 6 is arranged on the upper end face of the test box body 5, the heat preservation material 8 is wrapped on the outer surface of the horizontal freezing pipe 1, the freezing machine 3 and the horizontal multistage centrifugal pump 4 are respectively provided with a low-temperature alcohol input port 22 and a low-temperature alcohol output port 23, the horizontal multistage centrifugal pump 4 can bear a low temperature of-30 ℃, wire outlets are arranged on two sides of the lower bearing steel plate 7, the sealing discs 9 are respectively welded on two ends of the horizontal steel pipe 10, the horizontal steel pipe 10 is welded at the center of the sealing disc 9, the TDS thermodetector 11 is connected with a temperature measuring point inside the test box body 5 through a temperature measuring line 13, the oil cylinder 12 is placed between the self-reaction frame 2 and the lower bearing steel plate 7, an electric oil pump is adopted to pressurize the oil cylinder, an oil outlet 24 and an oil inlet 25 are arranged on the cylinder body, the low-temperature alcohol conveying pipe 14 is made of rubber, and the valve 15 is welded at one end of the horizontal freezing pipe 1. Preferably, in the single freezing pipe heat-preservation and cold-insulation similar model test device under the action of the ground stress, the self-reaction frame and the lower end bearing plate are made of Q235 steel materials, and the horizontal steel pipe is a seamless steel pipe with the diameter of 140mm, the thickness of 22mm and the length of 600 mm.

The specific test operation steps are as follows:

the method comprises the following steps: firstly, selecting a horizontal freezing pipe 1 with a proper length by measuring the distance between circular holes on two sides of the test box body 5, enabling the horizontal freezing pipe 1 to penetrate through the test box body 5, enabling two ends of the horizontal freezing pipe to be exposed out of the box body by 10cm, then arranging 3 temperature measuring points on a straight line parallel to the pipe axis on the upper side of the horizontal freezing pipe 1 at equal intervals, respectively arranging 3 temperature measuring lines 13 on the 3 temperature measuring points, fixing the 3 temperature measuring lines 13 on the upper side of the horizontal freezing pipe 1 by using an adhesive tape, then fixing the heat-insulating material 8 on the outer surface of the horizontal freezing pipe 1, and arranging 3 temperature measuring points on the outer surface of the heat-insulating material 8 in the same way;

step two: arranging a layer of temperature measuring points at intervals of 15cm from the lower side of the horizontal freezing pipe 1, arranging 3-4 layers in total, arranging 3 temperature measuring points on each layer, arranging 3 temperature measuring points on a straight line parallel to the axis of the horizontal freezing pipe 1 at equal intervals, and arranging 5-6 layers of temperature measuring points on the upper side of the horizontal freezing pipe 1 in the same manner;

step three: when the test box body 5 is filled with soil to the position of the embedded temperature measuring point, one end of the temperature measuring line 13 is embedded at the position of the temperature measuring point in the second step, the soil is filled layer by layer from bottom to top and the temperature measuring line 13 is embedded, after the soil is filled, the lower pressure bearing steel plate 7 is covered above the soil body, and the temperature measuring line 13 extends out of a wire outlet of the lower pressure bearing steel plate 7;

step four: welding the sealing discs 9 at two ends of the horizontal freezing pipe 1, welding the horizontal steel pipe 10 at the center of the sealing discs 9, and connecting the horizontal steel pipe 10, the congealer 3 and the horizontal multistage centrifugal pump 4 together through the low-temperature alcohol conveying pipe 14 to form a circulation loop;

step five: pouring low-temperature alcohol into the congealing machine 3, starting a refrigeration mode, then starting the horizontal multistage centrifugal pump machine 4, enabling the low-temperature alcohol to continuously circulate through the horizontal freezing pipe 1, connecting the temperature measuring line 13 extending in the third step to the TDS temperature measuring instrument 11, detecting whether the temperature measuring line 13 works normally, and closing the instrument after detecting and ensuring the normal work;

step six: firstly, placing the oil cylinder 12 on the lower pressure-bearing steel plate 7 by using a crane, connecting an electric oil pump with an oil inlet and an oil outlet on the oil cylinder 12 through an oil pipe, then applying pressure to a soil body by using the electric oil pump and the oil cylinder 12, then opening the TDS thermodetector 11, and starting temperature monitoring until the test is finished;

step seven: after the test is finished, storing test data on a computer, relieving the pressure of the oil cylinder 12, closing the TDS thermodetector 11, and opening a valve 15 on the horizontal freezing pipe 1 to discharge low-temperature alcohol;

step eight: and (3) arranging and analyzing test data, measuring the heat preservation and cold insulation performance of the heat preservation material 8 by taking the temperature of each temperature measuring point and the temperature difference value on the horizontal freezing pipe 1 as a standard, and when the temperature of a certain temperature measuring point is consistent with the room temperature, determining that the distance from the temperature measuring point to the horizontal freezing pipe 1 is the maximum range of the cold effect of the horizontal freezing pipe 1 when the heat preservation material 8 works.

It will be appreciated by those skilled in the art that the invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The embodiments disclosed above are therefore to be considered in all respects as illustrative and not restrictive. All changes which come within the scope of or equivalence to the invention are intended to be embraced therein.

Claims (1)

1. The single freezing pipe heat-preservation cold-insulation similar model test device under the action of ground stress comprises a horizontal freezing pipe, a self-reaction frame, a freezing machine, a horizontal multistage centrifugal pump machine, a test box body, lifting holes, a lower bearing steel plate, a heat-preservation material, a sealing disc, a horizontal steel pipe, a TDS (total dissolved solids) thermodetector, an oil cylinder, a temperature measuring line, a low-temperature alcohol conveying pipe and a valve, wherein the self-reaction frame is formed by welding nuts, screws, T-shaped steel, a cross-shaped steel beam, a bearing column and an upper bearing steel plate, two circular holes are formed in two sides of the test box body and are welded with the bearing column, the lifting holes are formed in the upper end face of the test box body, the heat-preservation material wraps the outer surface of the horizontal freezing pipe, the freezing machine and the horizontal multistage centrifugal pump machine are respectively provided with a low-temperature alcohol bearable input port and a low-temperature alcohol output port, and the horizontal multistage centrifugal pump machine is low in temperature of-30 ℃, the device comprises a lower pressure-bearing steel plate, a TDS (total dissolved solids) thermometer, a test box body, an oil cylinder, a self-reaction frame, a lower pressure-bearing steel plate, sealing discs, a horizontal steel pipe, an electric oil pump, an oil outlet and an oil inlet, wherein wire outlet holes are formed in two sides of the lower pressure-bearing steel plate, the sealing discs are welded at two ends of the horizontal steel pipe respectively, the horizontal steel pipe is welded at the center of the sealing discs, the TDS thermometer is connected with a temperature measuring point inside the test box body through a temperature measuring line, the oil cylinder is placed between the self-reaction frame and the lower pressure-bearing steel plate, the electric oil pump is used for pressurizing the self-reaction frame, the oil outlet and the oil inlet are formed in a cylinder body, a low-temperature alcohol conveying pipe is made of rubber, and a valve is welded at one end of the horizontal freezing pipe. The self-reaction frame and the lower end bearing plate are made of Q235 steel materials, the horizontal steel pipe is a seamless steel pipe, the diameter of the horizontal steel pipe is 140mm, the thickness of the horizontal steel pipe is 22mm, and the length of the horizontal steel pipe is 600 mm.

The invention also provides a single freezing pipe heat preservation and cold insulation similar model test method under the action of ground stress, which comprises the following steps:

the method comprises the following steps: firstly, selecting a horizontal freezing pipe with a proper length by measuring the distance between circular holes on two sides of the test box body, enabling the horizontal freezing pipe to penetrate through the test box body and expose out of the box body by 10cm at two ends, then arranging 3 temperature measuring points on a straight line on the upper side of the horizontal freezing pipe, which is parallel to the pipe axis, at equal intervals, respectively arranging 3 temperature measuring lines on the 3 temperature measuring points, fixing the 3 temperature measuring lines on the upper side of the horizontal freezing pipe by using an adhesive tape, then fixing the heat-insulating material on the outer surface of the horizontal freezing pipe, and arranging 3 temperature measuring points on the outer surface of the heat-insulating material in the same way;

step two: arranging a layer of temperature measuring points at intervals of 15cm from the lower side of the horizontal freezing pipe, arranging 3-4 layers in total, arranging 3 temperature measuring points on each layer, arranging 3 temperature measuring points on a straight line parallel to the axis of the horizontal freezing pipe at equal intervals, and arranging 5-6 layers of temperature measuring points on the upper side of the horizontal freezing pipe in the same manner;

step three: when the test box body is filled with soil to the position where the temperature measuring points are buried, burying one end of each temperature measuring line at the position of the temperature measuring point in the second step, filling soil layer by layer from bottom to top and burying the temperature measuring lines, covering the lower pressure-bearing steel plate above the soil body after filling the soil, and enabling the temperature measuring lines to extend out of wire outlet holes of the lower pressure-bearing steel plate;

step four: welding the sealing discs at two ends of the horizontal freezing pipe, welding the horizontal steel pipe at the center of the sealing discs, and connecting the horizontal steel pipe, the congealing machine and the horizontal multistage centrifugal pump together through the low-temperature alcohol delivery pipe to form a circulation loop;

step five: pouring low-temperature alcohol into the congealer and starting a refrigeration mode, then starting the horizontal multistage centrifugal pump, enabling the low-temperature alcohol to continuously circulate through the horizontal freezing pipe, connecting the temperature measuring line extending in the third step to the TDS temperature measuring instrument, detecting whether the temperature measuring line works normally, and closing the instrument after detecting and ensuring the normal work;

step six: firstly, placing the oil cylinder on the lower pressure-bearing steel plate by using a crane, connecting an electric oil pump with an oil inlet and an oil outlet on the oil cylinder through an oil pipe, then applying pressure to a soil body by using the electric oil pump and the oil cylinder, then opening the TDS temperature measuring instrument, and starting temperature monitoring until the test is finished;

step seven: after the test is finished, storing test data on a computer, unloading the pressure of the oil cylinder, closing the TDS thermodetector, and opening a valve on the horizontal freezing pipe to discharge low-temperature alcohol;

step eight: and (3) arranging and analyzing test data, measuring the heat preservation and cold insulation performance of the heat preservation material by taking the temperature of each layer of temperature measurement point and the temperature difference value on the horizontal freezing pipe as a standard, and when the temperature of a certain layer of temperature measurement point is approximately consistent with the room temperature, determining that the distance from the temperature measurement point of the soil layer to the horizontal freezing pipe is the maximum range of the cold quantity action of the freezing pipe when the heat preservation material works.

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