CN112923582A

CN112923582A - Stable anti-frost-expansion heat-collecting device and roadbed thereof

Info

Publication number: CN112923582A
Application number: CN202110321502.4A
Authority: CN
Inventors: 俞祁浩; 王俊峰; 牛富俊
Original assignee: Northwest Institute of Eco Environment and Resources of CAS
Current assignee: Northwest Institute of Eco Environment and Resources of CAS
Priority date: 2021-03-25
Filing date: 2021-03-25
Publication date: 2021-06-08

Abstract

The invention provides a stable anti-frost-heaving heat-accumulating device and a roadbed thereof, and relates to the technical field of disease control in engineering construction in seasonal frozen soil areas. The stable anti-frost-heaving heat gathering device comprises a solar heat absorption box, a circulating power unit, a heat gathering pipe and a circulating pipe, wherein the circulating power unit comprises a solar photovoltaic panel, a temperature controller and a circulating pump which are sequentially and electrically connected, the solar heat absorption box, the heat gathering pipe and the circulating pump are sequentially communicated end to end through the circulating pipe to form a circulating loop, the heat gathering pipe is used for being inserted into a roadbed, a first temperature sensor is used for detecting the temperature T1 of the solar heat absorption box, a second temperature sensor is used for detecting the temperature T2 of the heat gathering pipe, and the temperature controller is used for conducting current under the condition that T1 is larger than T2. The device can utilize solar energy resource, through the key regulation and control of road bed ground temperature field leveling heating, the easy frost heaving position of road bed, realizes that the road bed is balanced, level and smooth heating, effectively avoids the production of engineering diseases such as the frozen heaving of road bed in the frozen soil area in season, inhomogeneous fluctuation.

Description

Stable anti-frost-expansion heat-collecting device and roadbed thereof

Technical Field

The invention relates to the technical field of disease control of engineering construction in seasonal frozen soil areas, in particular to a stable anti-frost-heaving heat accumulation device and a roadbed thereof.

Background

The area of the seasonal frozen soil area in China is about 513.7 ten thousand square kilometers, and occupies 53.5 percent of the area of the national soil. The seasonal frozen soil is affected by seasonality, and is frozen in winter and completely melted in summer. When the frozen layer and the season melt layer in summer melt, the formation of uneven settlement of the soil layer due to uneven distribution of the ice layer and the ice lens body is an important cause for deformation and damage of various buildings. The characteristics of frost heaviness, melt-sinking and the like of the seasonal frozen soil have great influence on the engineering. Therefore, the engineering construction or project in the seasonally frozen soil region should pay special attention to the influence and the precautionary measures of the seasonally frozen soil on the engineering. For the roadbed, the form of roadbed frost damage mainly includes frost heaving, thawing sinking, slurry turning and mud pumping.

The Qinghai-Tibet railway is located in northeast of Qinghai-Tibet plateau at West section of Qinghai-Tibet railway, and railway lines pass through coastal plain, alluvial plain and ice plain lands of the northwest of Qinghai lake, and the average altitude is 3220 m. The average annual precipitation amount is 376mm, the precipitation distribution is uneven, most of the precipitation is concentrated in 7-9 months, the average annual temperature is-0.6 ℃, and the average annual temperature in the coldest month is-20.6 ℃ in 1 month. The Qinghai-Tibet railway West section has cold climate, strong freezing capacity of air temperature and larger freezing depth, the maximum freezing depth can reach 1.8m, and the Qinghai-Tibet railway West section belongs to a typical seasonal frozen soil area. Therefore, the engineering diseases such as roadbed frost heaving, thaw collapse and the like caused by freezing and thawing are relatively serious.

In recent years, due to the continuous increase of rainfall capacity of the Qinghai-Tibet plateau, the enrichment of underground water and the increase of underground water level are caused, and the further increase of freeze-thaw engineering diseases in the region is caused by the aggravation of climate environment change, so that the long-term stability of the roadbed is greatly influenced. Although the research is carried out on the roadbed diseases under the engineering action of the seasonal frozen soil area, the research is mainly carried out on the problems of the micro frozen swelling engineering action and influence of the roadbed and the like under the working condition of highway engineering or high-speed railways in northeast, northwest and other areas. But the research on the development characteristics and the distribution rule of the diseases of the freeze-thaw engineering under the special conditions of high water level, coarse filler, strong freeze-thaw and the like of the west grid section of the Qinghai-Tibet railway is lacked. In the application of the methods such as changing and filling foundation bed soil, building drainage facilities for reducing the water content of the foundation bed of the roadbed, an inorganic binder stabilized soil heat preservation method, artificial salinized foundation soil, chemical grouting, waterproof curtains and the like used in the conventional areas, the methods are limited by the engineering conditions that trains normally run and construction cannot be interrupted, and the cracking of the treated part and the overall sealing of the lower part of the roadbed are very difficult due to the strong freezing and thawing action of the soil body, so that the methods are difficult to meet the actual engineering requirements. Because the previous research on the engineering measures for treating the engineering diseases is weak, the stability and the operation safety of the roadbed are influenced for a long time by engineering problems.

Disclosure of Invention

The invention aims to provide a stable anti-frost heaving heat accumulation device and a roadbed thereof, which can realize balanced and smooth heating of the roadbed by utilizing solar energy resources and by leveling and heating the roadbed ground temperature field and key regulation and control of parts of the roadbed which are easy to frost heaving, and effectively avoid engineering diseases such as frost heaving, uneven fluctuation and the like of the roadbed in a seasonal frozen soil area.

Embodiments of the invention may be implemented as follows:

in a first aspect, the invention provides a stable anti-frost-heaving heat-gathering device, which comprises a solar heat absorption box, a circulating power unit, a heat-gathering pipe, a circulating pipe, a first temperature sensor and a second temperature sensor, wherein the circulating power unit comprises a solar photovoltaic panel, a temperature controller and a circulating pump which are sequentially and electrically connected, a solar heat absorption box, a heat collecting pipe and the circulating pump are sequentially communicated end to end through a circulating pipe to form a circulating loop, circulating working media are filled in the circulating loop, the heat collecting pipe is used for being inserted into a roadbed, a first temperature sensor is arranged in the solar heat absorption box, for detecting the temperature T1 of the solar heat absorption box, a second temperature sensor is arranged in the heat collecting pipe, the temperature detection device is used for detecting the temperature T2 of the heat collection pipe, the first temperature sensor and the second temperature sensor are both electrically connected with a temperature controller, and the temperature controller is used for conducting current under the condition that T1 > T2.

Therefore, under the condition that the temperature T1 of the solar heat absorption box is greater than the temperature T2 of the heat collecting pipe, the temperature controller conducts current, the solar photovoltaic panel can supply power to the circulating pump, heat absorbed by the solar heat absorption box is transferred to the heat collecting pipe through the circulating working medium, the heat is continuously released in the roadbed through the heat collecting pipe, soil bodies around the heat collecting pipe are heated, the roadbed is always in the process of net heat absorption and continuous accumulation of internal heat, the state that the heat is collected in the roadbed and the temperature is always kept at a positive temperature is achieved, and the purpose of preventing and treating engineering diseases such as roadbed soil body freezing, roadbed frost heaving and the like is achieved. That is, the set conditions for starting the circulation pump here include T1 > T2, whereby it is possible to avoid ineffective operation of the apparatus in winter or cloudy days.

In an optional embodiment, the circulating power unit further comprises a time controller, the solar photovoltaic panel, the time controller, the temperature controller and the circulating pump are sequentially connected in series, and the time controller is used for conducting current within a preset time period.

Therefore, in the preset time period and under the condition that T1 is greater than T2, the temperature controller and the time controller are conducted with current, and the solar photovoltaic panel can supply power to the circulating pump, so that the heat collecting pipe heats the roadbed. That is, the start conditions of the circulation pump are set to include T1 > T2 and within a preset time period, so that the device stops working in winter or cloudy days or in the case where the road bed does not need to be heated, and ineffective work is avoided.

In an alternative embodiment, the solar heat absorption box comprises a shell, a first header, a second header and a plurality of exhaust pipes, wherein the first header, the second header and the exhaust pipes are mounted in the shell, the plurality of exhaust pipes are arranged at intervals, one end of each exhaust pipe is communicated with the first header, the other end of each exhaust pipe is communicated with the second header, the second header is located below the first header, and one end of each second header, which is communicated with the heat collecting pipe, is lower than the other end of the second header.

Therefore, when the device stops working, the circulating working medium in the solar heat absorption box flows out of the solar heat absorption box as much as possible under the action of gravity, the phenomenon that the circulating working medium continuously absorbs heat of solar energy is avoided, boiling of the working medium in the solar heat absorption box is effectively avoided, and damage and adverse effects of high pressure formed by the vapor working medium on the whole system are avoided.

In an alternative embodiment, the height of the heat collecting pipe and the height of the circulating pump are both lower than the height of the solar heat absorption box.

Therefore, when the device stops working, the circulating working medium in the solar heat absorption box flows out of the solar heat absorption box as much as possible under the action of gravity and is stored in the heat collecting pipe or the circulating pump.

In an alternative embodiment, the number of the circulating pumps is multiple, and the multiple circulating pumps are connected in parallel between the solar heat absorption box and the heat collecting pipe.

Like this, set up two or more than two circulating pumps and parallelly connected, and only a circulating pump at every turn puts into use, after a circulating pump damages, puts into use another circulating pump again, has greatly improved life-span, stability and the reliability of system.

In an alternative embodiment, the heat focusing tube comprises:

an outer tube;

the liquid inlet pipe is communicated with the outside of the outer pipe and is communicated with one end of the circulating pipe;

and one end of the liquid outlet pipe is inserted into the outer pipe and is provided with an opening communicated with the outer pipe, and the other end of the liquid outlet pipe extends out of the outer pipe and is communicated with the other end of the circulating pipe.

Therefore, a heat release flow channel of the circulating working medium is formed between the outer pipe and the liquid outlet pipe, the circulating working medium is enabled to dissipate heat in the heat release flow channel, the heat dissipation flow channel is long, the heat transfer medium only has the pipe wall of the outer pipe, and the heat transfer efficiency is high.

In an alternative embodiment, the heat collecting pipe further comprises:

and the phase change energy storage body is arranged in the outer pipe and is positioned between the liquid outlet pipe and the outer pipe.

Therefore, the phase-change energy storage body absorbs or emits a large amount of heat, so that the severe fluctuation of the temperature inside the heat collecting pipe is avoided, the excessive rise of the temperature inside the heat collecting pipe is avoided, a large amount of vapor working media are generated, and the phenomenon of overpressure inside the system is favorably eliminated.

In an alternative embodiment, the angles of the heat collecting pipes rising from the inside of the roadbed to the outside in the length direction are as follows: 0 to 30 degrees.

Therefore, the heat collecting pipes are convenient to install in the roadbed, the drilling depth is small, the quantity is small, the original engineering structure of the roadbed cannot be changed, the stability of the original roadbed is guaranteed, the construction process does not influence the normal running of the train, and the difficult problem of engineering construction under the condition of meeting the running condition of the train is effectively solved.

In a second aspect, the present invention provides a stabilized frost heaving prevention heat accumulation roadbed, which comprises a roadbed and the stabilized frost heaving prevention heat accumulation device of any one of the previous embodiments, wherein the solar heat absorption box is installed outside the roadbed, and the heat accumulation pipe is inserted into the roadbed.

In an optional embodiment, the stabilized anti-frost-heaving heat-accumulation roadbed further comprises an insulation material layer, and the insulation material layer is arranged on the slope surface of the roadbed.

Therefore, under the condition of no solar radiation at night, the whole system stops working, and meanwhile, the heat insulation material layer on the outer side of the roadbed effectively prevents a large amount of heat inside the roadbed from being dissipated.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings needed to be used in the embodiments will be briefly described below, it should be understood that the following drawings only illustrate some embodiments of the present invention and therefore should not be considered as limiting the scope, and for those skilled in the art, other related drawings can be obtained according to the drawings without inventive efforts.

Fig. 1 is a schematic structural diagram of a stable frost heaving prevention heat accumulation roadbed provided by an embodiment of the invention;

FIG. 2 is a schematic front view of a stabilized frost heave prevention heat accumulation device;

FIG. 3 is a schematic side view of a stabilized frost heave prevention heat collection device;

FIG. 4 is a schematic illustration of the composition of the circulating power unit;

FIG. 5 is a schematic cross-sectional view of a heat-gathering pipe;

FIG. 6 is a schematic side view of a heat collecting pipe;

FIG. 7 is a schematic diagram of a plurality of groups of stable anti-frost-heaving heat accumulation devices arranged in parallel;

fig. 8 is a schematic view of a simulated calculation result geothermal field 30 days after the heat collecting pipes are arranged on the roadbed.

Icon: 1-stable type frost heaving prevention heat accumulation roadbed; 2-roadbed; 3-a heat insulating material layer; 4-a stable anti-freezing expansion heat-gathering device; 5-solar heat absorption box; 51-a housing; 52-a first header; 53-a second header; 54-calandria; 6-circulating pipe; 7-a first temperature sensor; 8-a second temperature sensor; 9-cycle power unit; 91-solar photovoltaic panel; 92-a time controller; 93-a temperature controller; 94-circulation pump; 10-heat collecting pipe; 101-an outer tube; 102-a liquid inlet pipe; 103-a liquid outlet pipe; 104-phase change energy storage body; 105-a scaffold; 106-cycle fluid; 11-anchor rod.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention. The components of embodiments of the present invention generally described and illustrated in the figures herein may be arranged and designed in a wide variety of different configurations.

Thus, the following detailed description of the embodiments of the present invention, presented in the figures, is not intended to limit the scope of the invention, as claimed, but is merely representative of selected embodiments of the invention. 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.

It should be noted that: like reference numbers and letters refer to like items in the following figures, and thus, once an item is defined in one figure, it need not be further defined and explained in subsequent figures.

In the description of the present invention, it should be noted that if the terms "upper", "lower", "inside", "outside", etc. indicate an orientation or a positional relationship based on that shown in the drawings or that the product of the present invention is used as it is, this is only for convenience of description and simplification of the description, and it does not indicate or imply that the device or the element referred to must have a specific orientation, be constructed in a specific orientation, and be operated, and thus should not be construed as limiting the present invention.

Furthermore, the appearances of the terms "first," "second," and the like, if any, are used solely to distinguish one from another and are not to be construed as indicating or implying relative importance.

It should be noted that the features of the embodiments of the present invention may be combined with each other without conflict.

The embodiment of the invention is provided aiming at the key scientific and technological problems in subgrade frost heaving, and the aims of controlling temperature and preventing and controlling subgrade frost heaving are achieved by arranging the device provided by the embodiment of the invention starting from the subgrade temperature in three indispensable essential elements of water, soil and temperature generated by subgrade frost heaving.

Referring to fig. 1, the present embodiment provides a stable frost heaving prevention heat accumulation roadbed 1, where the stable frost heaving prevention heat accumulation roadbed 1 includes a roadbed 2, a thermal insulation material layer 3 and a stable frost heaving prevention heat accumulation device 4, where the stable frost heaving prevention heat accumulation device 4 is installed on one side of a sunny slope or one side of a cloudy slope of the roadbed 2.

The heat insulation material layer 3 is arranged on the slope surface of the roadbed 2, can cover the whole slope surface of the roadbed 2 and is fixed through the anchor rods 11. In other embodiments, it is also possible to compact and fix the insulating-material layer 3 by covering the outer surface of the insulating-material layer 3 with a thin layer of soil or other material. The heat-insulating material layer 3 can be made of building rock wool heat-insulating materials or an integrated heat-insulating plate. Specifically, the sunny slope surface and the cloudy slope surface of the roadbed 2 can be provided with the heat insulation material layer 3, so that the heat inside the roadbed 2 can be prevented from dissipating, and the retention of the heat inside the roadbed 2 can be effectively guaranteed in the day and night change process.

Referring to fig. 1 and 2, the stable anti-frost-heaving heat collector 4 includes a solar heat absorption box 5, a circulating power unit 9, a heat collecting pipe 10, a circulating pipe 6, a first temperature sensor 7 and a second temperature sensor 8. The solar heat absorption box 5, the heat collecting pipe 10 and the circulating pump 94 in the circulating power unit 9 are sequentially communicated end to end through a circulating pipe 6 to form a circulating loop, a circulating working medium 106 is filled in the circulating loop, and the circulating working medium 106 is a freezing liquid, glass water or other liquid which is not frozen at the temperature of minus 30 ℃ and has good fluidity. The circulating pipe 6 is a metal pipe or a non-metal pipe which can resist outdoor solar radiation and aging.

The solar heat absorption box 5 can be arranged on the sunny slope side of the roadbed 2 and in the natural ground surface area close to the toe of the slope, or can be arranged on the cloudy slope side of the roadbed 2 and in the natural ground surface area capable of being irradiated by the sun in winter, and the solar heat absorption box 5 is used for absorbing solar energy and heating the circulating working medium 106.

The heat collecting pipe 10 is inserted into the roadbed 2 and transmits the heat of the circulating working medium 106 to the interior of the roadbed 2, so that the roadbed 2 is always in the processes of net heat absorption and continuous accumulation of internal heat, the heat collecting inside the roadbed and the temperature of the roadbed are always kept at a normal temperature, and the purposes of preventing and treating engineering diseases such as roadbed soil body freezing, roadbed frost heaving and the like are achieved.

The heat collecting pipe 10 is inserted into the roadbed 2 from a range between a half slope and a toe of the roadbed 2, and the insertion direction is perpendicular to the length direction of the roadbed 2. The length of the heat collecting pipe 10 can be determined according to actual conditions in the field. The included angle range between the length direction of the heat collecting pipe 10 and the horizontal plane is as follows: -30 ° to 30 °, in this embodiment, the angle of the heat collecting pipe 10 rising from the inside of the roadbed 2 to the outside in the length direction is preferably: specifically, the angle of elevation of the heat collecting pipe 10 in the x direction is 0 ° to 30 °, that is, as shown in fig. 1, the heat collecting pipe 10 extends in the x direction, and the angle of elevation in the y direction is 0 ° to 30 °, so that the height of the heat collecting pipe 10 is located at the middle-lower position of the roadbed 2, and the heat collecting pipe 10 spans most of the width of the roadbed 2. Therefore, the heat collecting pipes 10 are convenient to install in the roadbed 2, the drilling depth is small, the quantity is small, the original engineering structure of the roadbed 2 cannot be changed, the stability of the original roadbed 2 is guaranteed, the construction process does not influence the normal running of the train, and the difficult problem of engineering construction under the condition of meeting the running condition of the train is effectively solved.

The first temperature sensor 7 is installed in the solar heat absorption box 5 for detecting a temperature T1 of the solar heat absorption box 5. The second temperature sensor 8 is installed in the heat accumulating pipe 10 for detecting a temperature T2 of the heat accumulating pipe 10.

Referring to fig. 3, the solar heat absorption box 5 includes a housing 51, and a first header 52, a second header 53 and a plurality of rows of tubes 54 mounted in the housing 51, wherein the plurality of rows of tubes 54 are arranged at intervals, one end of each row of tubes 54 is connected to the first header 52, the other end of each row of tubes 54 is connected to the second header 53, the second header 53 is located below the first header 52, and one end of each second header 53 connected to the heat collecting pipe 10 is lower than the other end of the second header 53. Like this, when the device stops working, the circulation working medium 106 in the solar energy heat absorption case 5 can be under the effect of gravity, solar energy heat absorption case 5 of flowing out as far as possible, avoid circulation working medium 106 still continuously to absorb the heat of solar energy, effectively avoid the boiling of the inside working medium of solar energy heat absorption case 5, and the high pressure that steam state working medium formed damages and adverse effect that whole system caused, specifically, can design the contained angle of second collector 53 and water flat line and be 0 ~ 5, inside circulation working medium 106 all flows back to the inside of heat pipe 10 of gathering when further guaranteeing system stop work.

The height of the heat collecting pipe 10 and the height of the circulating pump 94 are both lower than the height of the solar heat absorption box 5. Thus, when the device stops working, the circulating working medium 106 in the solar heat absorption box 5 flows out of the solar heat absorption box 5 as much as possible under the action of gravity and is stored in the heat collecting pipe 10 or the circulating pump 94.

Referring to fig. 4, the circulating power unit 9 includes a solar photovoltaic panel 91, a time controller 92, a temperature controller 93 and a circulating pump 94, the solar photovoltaic panel 91, the time controller 92, the temperature controller 93 and the circulating pump 94 are sequentially connected in series, and the solar heat absorption box 5, the heat collecting pipe 10 and the circulating pump 94 are sequentially communicated end to end through the circulating pipe 6 to form a circulating loop. The solar photovoltaic panel 91 is used for absorbing solar power and supplying it to the time controller 92, the temperature controller 93 and the circulation pump 94. The time controller 92 is used for conducting current in a preset time period, and the temperature controller 93 is used for conducting current under the condition that T1 is greater than T2. Thus, the temperature controller 93 and the time controller 92 conduct the current only during the preset time period and under the condition that T1 > T2, that is, the start condition of the circulation pump 94 is set to include T1 > T2 and during the preset time period, so that the device stops working and avoids ineffective working in winter or cloudy days or in the case that the road bed does not need to be heated.

The time controller 92 mainly controls the working period, specifically, the working period from 11 months to 3 months in winter can be designed as the working period, the working period from 8 am to 6 pm in the daytime can be designed as the working period, and other dates and times are all in the off state. The temperature controller 93 controls the system to be turned on and off according to the temperature difference between the temperature probes arranged in the solar heat absorption box 5 and the heat collecting pipe 10, and is turned on when the temperature in the heat collecting pipe 10 is lower than the temperature in the solar heat absorption box 5, and is turned off otherwise. The temperature controller 93 and the time controller 92 are connected in series, and the circulation pump 94 starts to operate only when both are in an on state.

The circulating power unit 9 realizes multi-stage intelligent control on the circulating process of the device. The time controller 92 is used to control the start of the working period in winter and in daytime, and the temperature difference is further detected during the working period to control the system. Under the morning solar radiation condition, the temperature in the solar heat absorption box 5 can be continuously increased, and when the temperature in the solar heat absorption box 5 is higher than the temperature in the heat collecting pipe 10, the circulating pump 94 is started, the system starts to work, and the whole system heats the interior of the roadbed 2. In the afternoon, the temperature inside the solar heat absorption box 5 will decrease continuously under the condition that the solar radiation is weakened continuously, and when the temperature is lower than the temperature inside the heat collecting pipe 10, the circulating pump 94 is turned off, and the system stops working. Thereby avoiding inefficient operation of the device in winter or cloudy days.

Wherein, can set up two or more than two circulating pump 94 and connect in parallel, and only one circulating pump 94 comes into operation at every turn, after a circulating pump 94 damages, comes into operation with another circulating pump 94 again, has greatly improved life-span, stability and the reliability of system.

The circulation pump 94 is directly driven by the solar photovoltaic panel 91 without an external power supply. The circulating power unit 9 is mainly connected by an aging-resistant, high-strength hose and a joint. Programmable logic control programs are arranged in the time controller 92 and the temperature controller 93, firstly, the circulating pump 94 is driven to start working according to the comprehensive judgment of the daily change time and the solar radiation condition, and an overvoltage protection program for the circulating pump 94 can be arranged to ensure that the circulating pump 94 can work normally under the severe environment in the field. The circulation pump 94 may be a liquid pump or a gas pump, and the circulation medium 106 may be a liquid or a gas.

Referring to fig. 5 and 6, the heat collecting pipe 10 includes an outer pipe 101, a liquid inlet pipe 102, a liquid outlet pipe 103, a phase change energy storage body 104, and a support 105, wherein the liquid inlet pipe 102 is connected to the outside of the outer pipe 101 and is connected to one end of the circulation pipe 6. The liquid outlet pipe 103 is located at the bottom of the outer pipe 101, one end of the liquid outlet pipe 103 is inserted into the outer pipe 101 and is provided with an opening communicated with the outer pipe 101, and the other end of the liquid outlet pipe 103 extends out of the outer pipe 101 and is communicated with the other end of the circulating pipe 6. Thus, a heat release flow channel of the circulating working medium 106 is formed between the outer pipe 101 and the liquid outlet pipe 103, and the circulating working medium 106 is enabled to dissipate heat in the heat release flow channel, so that the heat dissipation flow channel is long, the heat transfer medium is only the pipe wall of the outer pipe 101, and the heat transfer efficiency is high. The design of the liquid inlet pipe 102 and the liquid outlet pipe 103 enables the heat collecting pipe 10 to be filled with the circulating working medium 106, so that heat exchange between the circulating working medium 106 and the pipe wall is more sufficient, and the heating efficiency of the heat collecting pipe 10 on the roadbed is further improved.

The phase change energy storage body 104 is installed in the outer tube 101 through the bracket 105 and located between the liquid outlet tube 103 and the outer tube 101, the phase change energy storage body 104 is immersed in the circulating working medium 106, and the phase change energy storage body 104 can be an organic material or an inorganic salt phase change material. Therefore, the phase-change energy storage body 104 absorbs or releases a large amount of heat, so that severe fluctuation of the internal temperature of the heat collecting pipe 10 is avoided, excessive rise of the internal temperature of the heat collecting pipe 10 is avoided, a large amount of vapor working media are generated, and the phenomenon of overpressure inside the system is eliminated.

Referring to fig. 7, the present embodiment further provides a stable frost heaving prevention heat accumulation roadbed, where the stable frost heaving prevention heat accumulation roadbed includes a plurality of groups of parallel stable frost heaving prevention heat accumulation devices 4, and the roadbed is heated by the parallel connection of the plurality of groups of stable frost heaving prevention heat accumulation devices 4, so that the heating efficiency of the roadbed can be improved. Specifically, a plurality of groups of stable anti-frost-heaving heat-collecting devices 4 can be arranged in parallel on one side of the roadbed, heat-collecting pipes 10 inserted from one side of the roadbed are uniformly arranged at certain intervals, and solar heat-absorbing boxes 5 are arranged in parallel.

In the practical application process, the flexible arrangement and combination of multiple factors of the heat collecting pipes, the heat insulating material layer and the solar heat absorption box can be carried out according to the engineering conditions of the roadbed trend, the height and the like, the solar radiation, the surrounding environment conditions of the field and the like, for example, the arrangement of the embedding angle and the spacing of the heat collecting pipes and one side or two sides of the heat insulating material layer is adjusted, even one layer of auxiliary heat insulating material is added, and the like, so that the temperature rising strength and the action area of the roadbed geothermal field are adjusted, and the optimal geothermal regulation and control effect is achieved.

The stable anti-frost-heaving heat accumulation device and the roadbed thereof provided by the embodiment have the working principles that:

under the daytime sunshine condition, the solar heat absorption box absorbs solar radiation to heat the internal circulating working medium, and then the heated circulating working medium is conveyed to the heat collecting pipe by the circulating power unit; the soil around the heat collecting pipe is heated by the continuous heat release of the heat collecting pipe in the roadbed. Under the condition of no solar radiation at night, the whole system stops working, and the phase-change energy storage body is filled in the heat collecting pipe, so that the heat energy absorbed in the daytime can be stored, the heat energy stored in the heat collecting pipe is continuously released, the soil around the heat collecting pipe is continuously heated, and the frost heaving of the roadbed at night is avoided; in addition, the heat insulation material layer outside the roadbed can effectively prevent a large amount of heat inside the roadbed from dissipating, and maintain the roadbed soil body in a normal temperature state. Therefore, in the day and night circulation and heat transfer processes, the roadbed is always in the processes of net heat absorption and continuous accumulation of internal heat, the states of heat accumulation inside the roadbed and constant positive temperature of the temperature are achieved, and the purposes of preventing and treating engineering diseases such as roadbed soil body freezing, roadbed frost heaving and the like are achieved.

The working principle also comprises: phase change energy storage bodies are longitudinally distributed and filled in the closed container of the heat collecting pipe, and the phase change energy storage bodies are solid and liquid interconversion materials. The phase-change energy storage body absorbs or emits a large amount of heat near the phase-change temperature, so that the violent fluctuation of the temperature in the heat collecting pipe is avoided, the excessive rise of the temperature in the heat collecting pipe is avoided, a large amount of vapor working media are generated, and the phenomenon of overpressure in the system is favorably eliminated; moreover, the heat exchange efficiency inside the system is also increased by prolonging the heat release process. The heat collecting pipe can be rectangular in shape, and can also be circular or other geometric shapes. The phase-change temperature of the phase-change energy storage body is 5-50 ℃.

The stable anti-frost-heaving heat accumulation device and the roadbed thereof have the advantages that:

1. the method has obvious difference and advantages with the prior engineering technology.

a) Change of prevention and control mode

In order to control the roadbed diseases in the frozen soil area in seasons, the embodiment directly starts with the root factor of 'ground temperature' causing the roadbed diseases, and heats the roadbed soil body through the continuous heat collection pipe, so that the roadbed soil body is always in a positive temperature state, and the roadbed soil body is prevented from being frozen and expanded due to negative temperature freezing. In addition, this embodiment directly heats the cycle fluid through solar energy heat absorption case, then directly carries the heat to road bed disease position by the circulating pump, has really realized from "production" to "consumption", does not have middle heat energy loss, and entire system is high-efficient, swift.

b) Change in overall system stability

The embodiment adopts a sensible and programmable logic control system, the circulating pumps are designed to be connected in parallel by two or more than two, only one circulating pump is put into use at each time, and the health working state of the circulating pump is monitored in real time by the perception system, so that the service life, the stability and the reliability of the system are greatly improved.

c) Environmental protection and energy consumption changes

The embodiment enriches the solar energy resource through make full use of local, realizes the purpose to the road base heating, and the energy can be saved, green. In the past roadbed electrical heating measures, the roadbed is heated by the roadbed internal electrical heating measures, external power supply is required, special power lines are required to be built and laid, a large amount of power resources are consumed each year, and the operation and maintenance cost is high when an internal electronic electrical heating system fails under the field use condition.

In conclusion, the freeze-thaw key control elements in the roadbed diseases in the seasonal area are solved, so that the effect of achieving double results with half the effort is achieved; meanwhile, the subgrade temperature isolines are horizontally and symmetrically distributed, so that the difference effect of subgrade thermal coupling is eliminated, and the stability of the subgrade mechanical field is further enhanced. The method effectively avoids the generation of engineering diseases such as uneven frost heaving, longitudinal cracking and the like of the roadbed, and ensures the long-term stability of the roadbed, so the method has outstanding scientificity and advancement.

2. The embodiment also prominently solves the existing engineering problem. In the embodiment, because the construction part is arranged on one side or two sides of the roadbed, the construction mode is horizontal punching, the roadbed is constructed in a point mode, the drilling speed is high when the roadbed is filled with soil, the opening diameter of the hole is small, and the stability of the roadbed is not influenced; meanwhile, in the implementation process, only holes and jacks are formed, and the influences of the previous measures such as grouting, replacement and filling on the roadbed, such as large-scale disturbance and mechanical property change are avoided, so that the stability of the original roadbed is further ensured, the influence of the construction process on the normal running of the train is avoided, and the difficulty in engineering construction under the running condition of the train is effectively solved.

3. The power cycle of the embodiment is obviously different from the prior solar energy cycle system.

a) In the aspect of structure, the solar photovoltaic panel directly starts the circulating pump without a battery or external power supply, and can meet the requirement of long-term stable operation in a severe outdoor environment. In the past, the solar energy circulating system must be provided with a battery or external electric power, and the circulating process is driven by related electric power or water pressure.

b) In the aspect of circulation requirements, the circulation of the embodiment has the characteristics of no pressure difference, short distance and self circulation of a closed system, so that the required driving force is small, the equipment load is small, the working condition of the equipment is good under the severe environment in the field, and the stability is high. The reverse is true of previous solar energy circulation systems.

c) In the aspect of the circulation mode, the temperature circulation of the embodiment is characterized by low temperature value and low grade heat energy circulation, the circulation work is started under the irradiation of the sun, and the sunset circulation is finished. In the former system, high temperature value and high grade heat energy are circulated, and the circulation time and the circulation mode are greatly different.

4. The heat absorption position of the embodiment is also characterized by being flexibly arranged according to site conditions, being arranged on two sides, being integrally arranged on one side, being arranged outside the roadbed or on the slope surface of the roadbed, and effectively solving different practical problems of limited site and fund or difficulty in engineering construction and the like.

5. In this embodiment, the solar energy heat absorption case is by aluminium alloy material integrated into one piece and from major, press close to ground or domatic placing, and every monomer can concatenate each other or connect in parallel, can greatly improve system stability under the strong wind adverse circumstances in western China, and the centrobaric reduction of heating element helps the formation and the increase of the whole thermal cycle thrust of device in addition to guarantee smooth and easy and high-efficient work of whole circulation and heat transfer process.

In order to verify the regulation and control efficiency of the stable anti-frost-heaving heat accumulation device and the roadbed thereof provided by the embodiment of the invention, numerical simulation calculation under the action of engineering measures is carried out by combining geological conditions of engineering sites from Xining to Guermu test of Tibet railway.

Example (c): on the slope surface on the side of the shadow slope of the Qinghai-Tibet railway roadbed with the height of 2.0m and the top surface width of 7.5m, heat collecting pipes are horizontally inserted into the roadbed at the height position of 0.5m, the insertion length is 8m, and the distance between the heat collecting pipes along the length direction of the roadbed is 2 m. In the heating system setup, the heating power is referred to the existing 1m²The heating power of the solar water heater in the region is 900W, the working time is 10 o 'clock in the daytime to 4 o' clock in the afternoon, and the effective power is reduced and calculated according to 50%. To further verify the effectiveness of this measure under adverse conditions, no insulation layer was laid on the subgrade slope in the simulation calculations.

Under the working condition, the heat collecting pipe is arranged at 12 months and 15 days, and the simulated calculation result geothermal field after the heat collecting pipe is arranged at 1 month and 15 days in winter in the current year is shown in figure 8. Fig. 8 is a cross-sectional view of the roadbed ground temperature at 8:30 morning and under the condition of lowest external environment temperature after the roadbed passes through a heat dissipation process in one night in day 30. It can be seen that, (a) in the aspect of the ground temperature value characteristics, the ground temperature of most areas in the roadbed is in a normal temperature state, the ground temperature of the bearing layer at the lower part of the embankment and the part with higher moisture is in a relatively high temperature area, and the highest temperature can reach 18 ℃; (b) in the aspect of the morphological characteristics of the ground temperature field, the ground temperature contour lines are horizontal and parallel to each other, especially the isothermal lines at 0 ℃ are distributed smoothly, namely the freezing area and the normal temperature area are parallel to each other, wherein the freezing area is only a small amount on the upper part of the roadbed and is distributed uniformly and symmetrically in a thin layer line mode, the frozen soil engineering problem can be effectively solved, and the morphological characteristics are as follows:

(1) the temperature state of the temperature field of the original roadbed central area is improved, the regulation and control requirements of the temperature field of the roadbed of the railway in the frozen soil area in seasons are met, and it can be seen from the graph in fig. 8 that after the implementation of the embodiment, the earth temperatures of the roadbed central area and the main bearing layer are in the normal temperature state, and normal temperature and high temperature soil nuclei are formed in the center of the roadbed;

(2) the distribution of the 0 ℃ earth temperature contour line and other isothermal lines of the temperature field is completely horizontal and flat, and the freezing areas are distributed on the top of the roadbed and close to the slope protection in a thin layer line mode, so that the stability of the roadbed is greatly improved, as can be seen from figure 8, the distribution of the roadbed temperature field is flat, particularly the distribution of the 0 ℃ isothermal lines is flat, the temperature field is integrally distributed in a convex mode in the roadbed, and the moisture in the roadbed is favorably discharged in the stage of frequent alternate actions of atmospheric precipitation and freeze thawing in early spring, so that the frost heaving amount of the roadbed is obviously reduced;

(3) the influence of yin-yang slope effect is eliminated, the engineering diseases of longitudinal subgrade cracking are basically eliminated, as can be seen from fig. 8, the subgrade temperature fields below the road surface are basically distributed symmetrically around the subgrade center, the temperature field isotherms in the subgrade are distributed smoothly, and the freezing zone is only distributed on the subgrade top surface and a thinner strip-shaped area under the slope protection, so that a small amount of transverse differential frost heaving generated by part of frozen parts is further weakened, and the possibility of longitudinal subgrade cracking is further eliminated.

The present example is only a representative analysis for the present invention, and the conclusion of the present example is that the trend (the difference in specific numerical value) basically represents the effect achieved by the present invention.

In addition, simulation calculation shows that the structure provided by the embodiment is used for railway construction in the frozen soil region in seasons, the frozen soil roadbed stores heat energy all the time during operation, and the freezing area in the roadbed is reduced along with the operation time, so that the structure can meet the requirement of roadbed mechanical stability and can maintain the roadbed stable for a long time.

Based on the roadbed structure disclosed in the above content, it can be seen that, in the face of broad roadbeds such as bidirectional or multi-strand railways, the pavement has larger heat release and freezing strength, and frost heaving engineering damage at the lower part and the center of the roadbed is more prominent, the embodiment can effectively solve the above problems through the application of the bilateral and low-level shallow buried balanced heat-gathering heating roadbed structure, and realizes the realization of the target of balanced, smooth and frost heaving prevention on the broad roadbeds.

The above description is only for the specific embodiments of the present invention, but the scope of the present invention is not limited thereto, and any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope of the present invention are included in the scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.

Claims

1. The stable anti-frost-heaving heat-gathering device is characterized by comprising a solar heat-absorbing box (5), a circulating power unit (9), a heat-gathering pipe (10), a circulating pipe (6), a first temperature sensor (7) and a second temperature sensor (8), wherein the circulating power unit (9) comprises a solar photovoltaic panel (91), a temperature controller (93) and a circulating pump (94) which are sequentially and electrically connected, the solar heat-absorbing box (5), the heat-gathering pipe (10) and the circulating pump (94) are sequentially communicated end to end through the circulating pipe (6) to form a circulating loop, a circulating working medium (106) is filled in the circulating loop, the heat-gathering pipe (10) is used for being inserted into a roadbed (2), and the first temperature sensor (7) is installed in the solar heat-absorbing box (5), the solar heat collecting box is used for detecting the temperature T1 of the solar heat collecting box (5), the second temperature sensor (8) is installed in the heat collecting pipe (10) and used for detecting the temperature T2 of the heat collecting pipe (10), the first temperature sensor (7) and the second temperature sensor (8) are both electrically connected with the temperature controller (93), and the temperature controller (93) is used for conducting current under the condition that T1 is larger than T2.

2. The device according to claim 1, wherein the circulating power unit (9) further comprises a time controller (92), the solar photovoltaic panel (91), the time controller (92), the temperature controller (93) and the circulating pump (94) are connected in series, and the time controller (92) is used for conducting current for a preset period of time.

3. The stable frost-proof thermal collector of claim 1, wherein the solar heat-absorbing box (5) comprises a housing (51), and a first header (52), a second header (53) and a plurality of pipes (54) mounted in the housing (51), wherein the pipes (54) are arranged at intervals, one end of the pipes (54) is connected to the first header (52), the other end of the pipes (54) is connected to the second header (53), the second header (53) is located below the first header (52), and one end of the pipe (10) is connected to the second header (53) by the second header (53).

4. The stationary frost heave prevention heat collection device of claim 1, wherein the height of the heat collection pipe (10) and the height of the circulation pump (94) are both lower than the height of the solar heat absorption tank (5).

5. The device according to claim 1, wherein the number of the circulation pumps (94) is plural, and plural circulation pumps (94) are connected in parallel between the solar heat absorption tank (5) and the heat collecting pipe (10).

6. The stable frost heave prevention heat collection device of claim 1, wherein the heat collection tube (10) comprises:

an outer tube (101);

a liquid inlet pipe (102) communicated with the outside of the outer pipe (101) and communicated with one end of the circulating pipe (6);

drain pipe (103), the one end of drain pipe (103) is inserted the inside of outer tube (101), and seted up with the opening of outer tube (101) intercommunication, the other end of drain pipe (103) stretches out outer tube (101), and with the other end intercommunication of circulating pipe (6).

7. The stable frost heave prevention heat collection device of claim 6, wherein the heat collection tube (10) further comprises:

and the phase change energy storage body (104) is arranged in the outer pipe (101) and is positioned between the liquid outlet pipe (103) and the outer pipe (101).

8. The stable frost heaving prevention heat collection device of claim 1, wherein the angle of the heat collection pipe (10) rising from the inside of the roadbed (2) to the outside in the length direction is: 0 to 30 degrees.

9. A stabilized frost heaving prevention heat accumulation roadbed, characterized in that the stabilized frost heaving prevention heat accumulation roadbed comprises a roadbed (2) and the stabilized frost heaving prevention heat accumulation device of any one of claims 1 to 8, wherein the solar heat absorption box (5) is installed outside the roadbed (2), and the heat accumulation pipe (10) is inserted inside the roadbed (2).

10. The stabilized frost heaving prevention heat accumulation roadbed according to claim 9, wherein the stabilized frost heaving prevention heat accumulation roadbed further comprises an insulation material layer (3), and the insulation material layer (3) is arranged on the slope surface of the roadbed (2).