An inorganic heat pipe electrically heated airport pavement deicing and snow melting system and its operation control method

Abstract

The present invention discloses an inorganic heat pipe electrically heated airport pavement de-icing and snow-melting system and its operation control method. The pavement de-icing and snow-melting system includes an inorganic heat pipe assembly, an electrically heated airport pavement structure, and a feedback control system. By analyzing the temperature field distribution characteristics of the pavement surface, the pavement de-icing and snow-melting demand is accurately obtained, and the demand is fed back to the feedback control system. The pavement de-icing and snow-melting system is started and operated. During the operation of the pavement de-icing and snow-melting system, the condition of weak points on and inside the pavement is monitored in real time. This information is compared with the target value of the de-icing and snow-melting demand to obtain an error result. The system operation state is adjusted in a timely manner according to the error result, and ultimately the operation result of the pavement de-icing and snow-melting system meets the target demand. The present invention solves the problems of existing technologies such as chemical de-icing agent methods and mechanical removal methods in de-icing and snow-melting pavements in high-altitude and cold airports, such as insufficient timeliness, poor applicability in extreme environments, and damage to the functional characteristics of the pavement surface.

Description

Technical Field

[0001] The present invention relates to an airport pavement deicing and snow-melting system and an operation control method thereof, and in particular to an inorganic heat pipe electrically heated airport pavement deicing and snow-melting system and an operation control method thereof. Background Art

[0002] Under the harsh natural conditions of high-altitude and cold regions, snow and icing events caused by extreme weather conditions such as extremely low temperatures and severe convection pose significant challenges to the efficient and safe operation of airport pavements. This is especially true when faced with sudden, severe temperature drops and heavy snowfalls in small, unpredictable environments. If runway de-icing and snow-melting measures are not timely and effective, aircraft will be grounded due to the inability to meet safe taxiing conditions during takeoff, or forced to make an emergency landing due to the lack of a suitable alternate airport. This can easily lead to large-scale airport delays and even aviation accidents. Therefore, for airports in high-altitude and cold regions, pavement de-icing and snow-melting technologies that are responsive, timely, efficient, and able to proactively adapt to complex and changing adverse weather events are extremely necessary and urgent.

[0003] At present, airport pavement de-icing and snow-melting technology still relies on conventional chemical de-icing agents and mechanical removal methods. However, both methods have certain limitations in the high-altitude and cold environment: (1) The de-icing effect of spreading de-icing agents is greatly affected by the ambient temperature, and it is difficult to achieve the desired effect in extreme weather conditions. Long-term and excessive use will inevitably cause erosion of pavement surface materials and ancillary facilities, and also interfere with the fragile ecological balance of water bodies and soil in high-altitude and cold areas of the plateau, which is contrary to the environmental protection concept of green, low-carbon and sustainable development. (2) The mechanical de-icing process often requires the closure of the flight area, affecting the normal operation of the airport. When facing long-term snowfall, in order to ensure safe aircraft take-off and landing conditions, mechanical de-icing needs to be carried out repeatedly. The de-icing efficiency is not high, the hidden ice is difficult to remove thoroughly, and the maintenance and operation costs are high. Frequent mechanical de-icing operations will cause physical damage to the surface of the airport pavement, reduce the anti-skid and durability properties of the runway, and bring potential safety risks to the aircraft take-off and landing process.

[0004] Gravity heat pipes and fluid heat pipes are new technologies that use thermal methods to remove snow and ice from airport pavements, achieving environmentally friendly, lossless and efficient de-icing and snow melting. However, both still have certain defects in their application in high-altitude and cold plateau environments: (1) The construction of gravity heat pipes is relatively complex, requiring the drilling of a certain depth of heat extraction wells, which has special requirements for professional drilling machinery and has certain construction complexity and technical barriers. In high-altitude and cold plateau areas, there are many hard rock structures, which are not convenient for construction operations. In addition, the heating temperature range of gravity heat pipes is limited by the heat extraction depth. If a wider temperature adaptation range is to be achieved in the high-altitude and cold plateau environment, deeper heat extraction wells need to be drilled, which increases the construction difficulty and cost. (2) Fluid heat pipes have high requirements for the quality and stability of the heat source. Although fluid heat pipes can adopt a variety of heat sources such as geothermal energy and solar energy, they all require the construction of heat pump units to increase the fluid temperature and stability, which also has certain construction difficulty and technical barriers. When faced with the need for de-icing and snow melting in extremely low temperature environments in high-altitude and cold plateau areas, the fluid must maintain a high temperature, which increases the difficulty of obtaining and maintaining the stability of the heat source, and increases the construction and operation costs.

[0005] In response to the above-mentioned problems, if the environmental protection, lossless and efficient thermal snow melting advantages of heat pipe technology are organically combined with the convenient, stable and controllable energy supply advantages of electric power, a new type of active pavement ice and snow removal technology and its operation control method can be developed, it can achieve fast response, thorough removal, on-demand operation, green and economical ice and snow melting operations, and meet the multiple special needs of airport pavement snow removal in extreme environments of plateau and cold areas in terms of efficiency, safety, environmental protection, timeliness, convenience, economy, and all-weather. Summary of the Invention

[0006] In response to the problems of existing technologies such as chemical deicing agents and mechanical removal methods in deicing and snowmelting pavements at high-altitude and cold airports, such as lack of timeliness, poor applicability in extreme environments, and damage to the functional properties of the pavement surface, the present invention combines the advantages of heat pipe deicing and electric power supply to propose an inorganic heat pipe electric heating airport pavement deicing and snowmelting system and its operation control method.

[0007] The purpose of the present invention is achieved through the following technical solutions:

[0008] An inorganic heat pipe electrically heated airport pavement deicing and snow melting system includes an inorganic heat pipe component, an electrically heated airport pavement structure, and a feedback control system, wherein:

[0009] The inorganic heat pipe assembly consists of a single inorganic heat pipe body, a heating rod and a sealing structure;

[0010] The electrically heated airport pavement structure is composed of a cement-stabilized crushed stone base layer, a cement concrete surface layer, an inorganic heat pipe array, and an inorganic heat pipe support grid.

[0011] The feedback control system consists of a pre-buried temperature monitoring sensor assembly, a temperature acquisition device, a non-contact ice and snow state sensing system, and a heating control system;

[0012] The non-contact ice and snow state sensing system consists of an infrared sensor probe, a probe bracket, a cylindrical pole, an ice and snow state data collection box, a pre-buried ground cage, a cement concrete pier foundation, and a data transmission line;

[0013] The heating control system includes an electric control box, a heat pipe wire, a first branch wire, and a second branch wire;

[0014] The first and second ends of the inorganic heat pipe body are sealed, a heat pipe cavity is formed in the pipe, and the heat pipe cavity is filled with a heat transfer medium. A heating rod is provided at the second end of the inorganic heat pipe body, and the heating rod is connected to the heat pipe wire. A sealed cavity is provided at the connection between the heating rod and the heat pipe wire, and the sealed cavity is provided in a sealing member, which is connected to a sealing plug to form a sealed structure.

[0015] The inorganic heat pipe support grid is composed of horizontal support steel bars and vertical support steel bars. One end of the vertical support steel bar is embedded in the cement-stabilized gravel base, and the other end is welded to the horizontal support steel bar. The inorganic heat pipe array is composed of multiple inorganic heat pipe components. The multiple inorganic heat pipe components are arranged in parallel at equal intervals on the horizontal support steel bars to form an array heating structure. The heat pipe wires are connected to the electrical control box.

[0016] The temperature monitoring sensor assembly includes several temperature sensors, which are arranged on the surface of the cement concrete surface layer, at both ends of the inorganic heat pipe body, in the middle of the inorganic heat pipe body, and at 1 / 2 of the distance between two inorganic heat pipe bodies;

[0017] The temperature sensor is connected to the temperature acquisition device via a sensor wire, and the temperature acquisition device is connected to the electric control box via a first branch wire to realize power supply;

[0018] The pre-buried cage is buried in the cement concrete pier foundation, the bottom of the cylindrical pole is fixed to the anchor bolt exposed by the pre-buried cage, an ice and snow status data collection box is installed on the middle and lower sections of the cylindrical pole, a probe bracket is installed on the top of the cylindrical pole, an infrared sensor probe is installed at the front end of the probe bracket, the infrared sensor probe is connected to the ice and snow status data collection box through a data transmission line, and the ice and snow status data collection box is connected to the power supply inside the electric control box through a second branch wire;

[0019] The electric control box controls the connection and disconnection of the heat pipe wire, the first branch wire, and the second branch wire respectively through the circuit switch.

[0020] A method for controlling the operation of the inorganic heat pipe electrically heated airport pavement deicing and snow melting system comprises the following steps:

[0021] Step (1) When snow begins to fall, an AC power supply is connected, a heating control system is started, the inorganic heat pipe array is operated, and the airport pavement structure is heated electrically;

[0022] Step (2) starts the non-contact ice and snow state sensing system, and measures and calculates the average snow thickness on the road surface at 1 minute intervals;

[0023] Step (3) turning on the pavement internal temperature monitoring sensor assembly and the temperature acquisition device, and measuring the temperature of a single inorganic heat pipe wall, between two inorganic heat pipes, and the pavement surface at intervals of 10 to 20 minutes;

[0024] Step (4) determines the stopping time of the heating process of the inorganic heat pipe electric heating airport pavement deicing and snow melting system, and adopts the following judgment conditions: when the average snow thickness of the pavement is h snow,avg No greater than target snow layer thickness h snow,tgt = 0 mm, or when the maximum temperature gradient between all measuring points is gard T max Not less than the critical temperature gradient gard T crit =100℃ / m, the heating process of the inorganic heat pipe array stops, and the heating control system switches to regulating the temperature to remain constant; otherwise, the heating control system continues heating operation;

[0025] Step (5) After the snow stops, if the average snow thickness on the road surface is h snow,avg Greater than the target snow layer thickness h snow,tgt = 0mm, follow step (4); if the average snow thickness h snow,tgt Less than target snow layer thickness h snow,tgt = 0mm, the heating control system continues to operate, the inorganic heat pipe array continues to heat up, and the snow melt water on the road surface evaporates;

[0026] Step (6) determines the stopping time of the evaporation process of the inorganic heat pipe electric heating airport pavement deicing and snow melting system, and adopts the following judgment conditions: ① When the maximum temperature gradient gard T between all measuring points max Not greater than the critical temperature gradient gardT crit =100℃ / m, if the average water film thickness of the road surface is h water,avg Not greater than the target water film thickness h water,tgt = 0mm, the heating process of the inorganic heat pipe array stops, and the heating control system is shut down. Otherwise, the process returns to step (5); ② When the maximum temperature gradient gard T between all measuring points is max Greater than the critical temperature gradient gard T crit=100℃ / m, the inorganic heat pipe array temperature rise process stops, and the heating control system switches to regulating the temperature to remain constant until the average water film thickness on the road surface reaches h water,avg Less than the target water film thickness h water,tgt =0mm, the heating control system is shut down;

[0027] After the heating control system is turned off in step (7), the temperature monitoring sensor assembly, the temperature acquisition device, and the non-contact ice and snow status sensing system stop running, the AC power supply is cut off, and the road surface snow melting operation is completed.

[0028] Compared with the prior art, the present invention has the following advantages:

[0029] (1) Using inorganic heat pipes with high electric heat conversion rate, fast heat transfer rate and large heating capacity, and forming a heating array, can achieve fast and efficient de-icing and snow melting on the road surface. The heating heat load of the inorganic heat pipe is not less than 600W / m 2 The heating rate can reach up to 20°C / hour, and only requires a conventional 220V AC power supply. Compared to traditional chemical de-icing agents and mechanical de-icing methods, this system can quickly and efficiently respond to sudden heavy snowfall events in the high-altitude, cold plateau environment. It has strong adaptability to extreme environments. Furthermore, thermal de-icing can completely remove hidden ice from the road surface and maintain its anti-skid structure, achieving both de-icing and anti-skid effects.

[0030] (2) The inorganic heat pipe heating array is installed by using steel support brackets and steel wire tying to fix. After the pavement is cast and hardened, the steel formwork is removed, and the heating rod is installed at the heating end of the inorganic heat pipe and sealed to complete the laying of the inorganic heat pipe. The construction process is simple, the process is relatively simple, and the laying is convenient. Compared with traditional gravity heat pipes and fluid heat pipes, there is no need for additional large-scale special machinery and equipment to drill deep holes and bury heat pipes, and the construction of energy conversion and lifting devices such as heat pump units is avoided. The design and construction cost is low and the speed is fast. The environmental interference during the construction process is low. The construction of inorganic heat pipe electric heating pavement in the high-altitude and cold environment has the outstanding advantages of being green and low-carbon.

[0031] (3) The use of an electrically heated inorganic heat pipe pavement structure can ensure that the de-icing and snow-melting operations on the airport pavement are controlled on demand, safe and economical, and meet the needs of emergency response. The electrically heated inorganic heat pipe pavement structure can start and stop the system by turning the power on and off. The system's operation control operation is simple and the conversion is fast. In particular, in response to the changeable weather conditions and extreme weather intensity at high-altitude and cold airports, the feedback control system can monitor the pavement temperature conditions and adjust the system operation process at any time according to changes in environmental conditions. It can quickly respond to weather changes, reasonably optimize the system working strategy, and effectively save system operating costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 Schematic diagram of inorganic heat pipe electric heating for de-icing and snow melting of airport pavement and its control system;

[0033] Figure 2 Schematic diagram of the three-dimensional structure of the inorganic heat pipe assembly;

[0034] Figure 3 Schematic diagram of the cross-sectional structure of an inorganic heat pipe assembly;

[0035] Figure 4 This is the structural diagram of the inorganic heat pipe electrically heated airport pavement;

[0036] Figure 5 This is the plan layout diagram of the inorganic heat pipe support grid;

[0037] Figure 6 This is a cross-sectional layout diagram of the inorganic heat pipe support grid;

[0038] Figure 7 This is a front view of the non-contact ice and snow state perception sensor structure;

[0039] Figure 8 This is a top view of the non-contact ice and snow state perception sensor structure;

[0040] Figure 9 Installation diagram for inorganic heat pipe array;

[0041] Figure 10 The structural diagram for the layout of the pavement internal temperature monitoring sensor;

[0042] Figure 11 This is the connection structure diagram of the inorganic heat pipe electric heating airport pavement deicing and snow melting system;

[0043] Figure 12 This is the operation control flow chart of the inorganic heat pipe electric heating airport pavement deicing and snow melting system;

[0044] Figure 13 This is a graph of the pavement temperature change during the deicing and snow melting process of an airport pavement electrically heated by an inorganic heat pipe;

[0045] Figure 14 This is a graph showing the changes in snow thickness and water film thickness on the pavement surface during the deicing and snow melting process of an airport pavement electrically heated by an inorganic heat pipe.

[0046] Figure 15 This is the operating effect diagram of the inorganic heat pipe electric heating airport pavement deicing and snow melting system;

[0047] In the figure: 1-inorganic heat pipe body; 2-first end; 3-second end; 4-heat pipe cavity; 5-heating rod; 6-heat pipe wire; 7-sealed cavity; 8-seal; 9-sealing plug; 10-rubber ring; 11-cement stabilized gravel base layer; 12-cement concrete surface layer; 13-U-shaped protective groove; 14-horizontal support steel bar; 15-vertical support steel bar; 16-electrical control box; 17-prefabricated cover plate; 18-temperature sensor; 19-sensor wire; 20-temperature acquisition device; 21-first branch wire; 22-infrared sensor probe; 23-probe bracket; 24-cylindrical pole; 25-ice and snow status data acquisition box; 26-buried cage; 27-cement concrete pier foundation; 28-data transmission line; 29-second branch wire. DETAILED DESCRIPTION

[0048] The technical solution of the present invention is further described below with reference to the accompanying drawings, but is not limited thereto. Any modification or equivalent replacement of the technical solution of the present invention that does not depart from the spirit and scope of the technical solution of the present invention should be included in the scope of protection of the present invention.

[0049] Specific implementation method 1. This implementation method provides an inorganic heat pipe electric heating airport pavement deicing and snow melting system, such as Figures 1 to 8 As shown, the deicing and snow melting system includes an inorganic heat pipe assembly, an electrically heated airport pavement structure, and a feedback control system, wherein:

[0050] The inorganic heat pipe assembly consists of a single cylindrical, slender inorganic heat pipe body 1, a heating rod 5, and a sealing structure. The inorganic heat pipe body 1 has a diameter of 28 to 32 cm and a length of 4.0 m. The outer tube body is made of a corrosion-resistant carbon steel alloy. The first end 2 and the second end 3 are sealed with a low thermal conductivity material. A heat pipe cavity 4 is formed in the tube, and the heat pipe cavity 4 is filled with a heat transfer medium with excellent thermal conductivity. A heating rod 5 is provided at the second end 3 of the inorganic heat pipe body 1. The heating rod 5 is connected to a heat pipe wire 6. A sealed cavity 7 is provided at the connection between the heating rod 5 and the heat pipe wire 6. The sealed cavity 7 is provided in a sealing member 8 and is filled with sealant. A rubber ring 10 is provided between the sealing member 8 and the sealing plug 9. The sealing member 8 and the sealing plug 9 are threadedly connected to form a sealed structure. After power is turned on, the heating rod 5 starts working, directly heating the heat transfer medium in the heat pipe cavity 4, causing the temperature of the inorganic heat pipe body 1 to rise and dissipate heat radially through the pipe wall. The heating power of a single inorganic heat transfer pipe is 600W.

[0051] The electric heating airport pavement structure is composed of a cement stabilized gravel base layer 11, a cement concrete surface layer 12, an inorganic heat pipe array, an inorganic heat pipe support grid, and a U-shaped protective groove 13. The inorganic heat pipe support grid is composed of a horizontal support steel bar 14 and a vertical support steel bar 15, wherein one end of the vertical support steel bar 15 is embedded in the cement stabilized gravel base layer 11 and the other end is welded to the horizontal support steel bar 14; the inorganic heat pipe array is composed of a plurality of inorganic heat pipe components, and the plurality of inorganic heat pipe components are arranged in parallel on the horizontal support steel bar at a certain distance. 14, forming an array heating structure, the inorganic heat pipe body 1 and the horizontal support steel bar 14 are bound with steel wire; one end of the inorganic heat pipe containing the heating rod 5 is aligned with the edge of the cement concrete surface layer 12, the heat pipe wire 6 is connected to the electric control box 16, and a U-shaped protective groove 13 is provided at the edge of the cement concrete surface layer 12. The temperature sensor wire 19 and the heat pipe wire 6 are placed in the U-shaped protective groove 13 to prevent rainwater intrusion and sunlight exposure; the U-shaped protective groove 13 is cast with cement concrete or masonry, and a prefabricated cover plate 17 is provided on the top of the groove.

[0052] The feedback control system is composed of a pre-buried temperature monitoring sensor assembly, a temperature acquisition device 20, a non-contact ice and snow state perception system, and a heating control system; the temperature monitoring sensor assembly includes a plurality of temperature sensors 18, which are arranged on the surface of the cement concrete surface layer 12, the two ends of the inorganic heat pipe body 1, the middle of the inorganic heat pipe body 1, and the 1 / 2 position of the distance between the two inorganic heat pipe bodies 1; the temperature sensor 18 is connected to the temperature acquisition device 20 through a sensor wire 19, and the temperature acquisition device 20 is connected to the electric control box 16 through a first branch wire 21 to realize power supply. The temperature acquisition device 20 receives temperature data at a certain time interval to obtain the temperature field state inside the heated pavement structure; the non-contact ice and snow state perception system is a pavement condition sensor based on infrared laser remote sensing technology, which is installed in the form of a column on the side of the pavement panel to measure the state and thickness of ice, snow, and water film on the pavement as required. The non-contact ice and snow state perception system is composed of an infrared sensor probe 22, a probe bracket 23, a cylindrical pole 24, an ice and snow state data acquisition box 25, a pre-buried The pre-buried cage 26 is embedded in the cement concrete pier foundation 27, and the bottom of the cylindrical pole 24 is fixed on the anchor bolt exposed by the pre-buried cage 26. The middle and lower sections of the cylindrical pole 24 are fastened to the ice and snow status data collection box 25 with a clamp, and the top of the cylindrical pole 24 is fastened to the probe bracket 23 with a clamp. The front end of the probe bracket 23 is equipped with an infrared sensor probe 22, and the infrared sensor probe 22 is connected to the ice and snow status data collection box 25 through the data transmission line 28. The snow status data collection box 25 is connected to the power supply inside the electrical control box 16 through the second branch conductor 29; according to the snow melting demand, temperature conditions and ice and snow conditions of the pavement, the heating control system can be turned on or off to achieve pavement heating and cooling; the heating control system includes the electrical control box 16, the heat pipe conductor 6, the first branch conductor 21, and the second branch conductor 29. The electrical control box 16 controls the connection and disconnection of the heat pipe conductor 6, the first branch conductor 21, and the second branch conductor 29 through the circuit switch, thereby realizing the operation of the inorganic heat pipe electrically heated airport pavement deicing and snow melting system.

[0053] In this embodiment, the inorganic heat pipe electrically heated airport pavement de-icing and snow-melting system primarily utilizes the conversion of electrical energy into thermal energy. In this system, the electric heating element, an inorganic heat pipe assembly, boasts high energy conversion efficiency and temperature rise rates. Embedded within the pavement structure, the element rapidly heats one end of the inorganic heat pipe assembly when current is applied. This heat is then transferred to the inorganic heat transfer fluid within the heat pipe, uniformly heating the entire pipe body. The inorganic heat pipe then transfers the heat to the pavement material, gradually raising the surface temperature of the electrically heated airport pavement structure through heat conduction, increasing the heat flux required to melt the snow, and ultimately achieving the melting of accumulated snow and ice.

[0054] Specific embodiment 2: This embodiment provides a construction method of the inorganic heat pipe electrically heated airport pavement deicing and snow melting system as described in specific embodiment 1. The method is implemented according to the following steps:

[0055] (1) Paving heated pavement cement stabilized gravel base structure:

[0056] On the stable soil base structure, a paver is used to evenly spread the cement-stabilized gravel base layer 11 in layers according to thickness. The spreading thickness is 38 to 42 cm, and the cement dosage is 4.0 to 5.0%. When the moisture content of the cement-stabilized gravel base layer 11 is at the optimum moisture content, a roller is immediately used to compact it within the full width of the structural layer. After the compaction is completed and the compaction degree is checked to be qualified, the compacted cement-stabilized gravel base layer 11 is covered and cured. The curing period is not less than 7 days. During this period, the cement-stabilized gravel base layer 11 is kept moist. After the curing is completed, the pavement structure layer of the cement-stabilized gravel base layer 11 that is fully solidified and meets the strength standards is obtained.

[0057] The mix ratio and raw materials of the base materials shall be in accordance with the "Technical Specifications for Construction of Earthwork and Pavement Base (Cushion) Layers in Civil Airport Airfields" (MH / T 5014-2022).

[0058] (2) Installing the inorganic heat pipe support grid;

[0059] Several small holes with a depth of 1 / 3 of the base thickness are drilled on the base structure, and a single vertical support steel bar 15 is placed in each small hole. Cement-stabilized gravel is backfilled and fixed after hardening. Horizontal support steel bars 14 are welded to the vertical support steel bars 15 to obtain an inorganic heat pipe support grid.

[0060] (3) fixing the inorganic heat pipe array heating structure;

[0061] Several inorganic heat pipe assemblies are arranged at equal intervals on the horizontal support steel bars 14, and the inorganic heat pipe body 1 is fixed to the horizontal support steel bars 14 by steel wire binding. When the inorganic heat pipe body 1 is placed, the end containing the heating rod 5 is aligned with one side of the road surface. The inorganic heat pipe body 1 is placed at an angle with a slope of 1 to 2%, and the end containing the heating rod 5 is slightly lower.

[0062] (4) Installing temperature sensors inside the pavement;

[0063] Temperature sensors 18 are arranged on the side walls of the pipe at both ends and the middle position of a single inorganic heat pipe body 1, and at 1 / 2 the pipe spacing in the middle position of two inorganic heat pipe bodies 1. In addition, temperature sensors 18 are arranged on the surface of the pavement cement concrete surface layer 12, and the sensor wires 19 connected to the temperature sensors 18 are led out of the pavement structure and connected to the temperature collection device 20.

[0064] (5) Casting the heated pavement cement concrete surface structure;

[0065] Install the pavement surface construction steel formwork, pour the newly mixed cement concrete, use a paver to evenly spread the cement concrete, the spreading thickness is 38 to 40 cm, use an inserted vibrator or a flat vibrator to vibrate the spread concrete to ensure that the concrete is dense and eliminate bubbles. After the vibration is completed, use a scraper or a leveler to level the pavement surface immediately, and then perform anti-slip treatment such as roughening and grooving on the surface. After the construction is completed, cover with geotextile and use wet curing method for no less than 14 days. After the cement concrete hardens and forms strength, the heated pavement cement concrete surface layer 12 structure is obtained.

[0066] The mix ratio and raw materials of the surface materials shall be in accordance with the "Technical Specifications for Construction of Cement Concrete Pavement Surface Layers in Civil Airport Airfields" (MH5006-2015).

[0067] (6) Set up a non-contact ice and snow status sensing system;

[0068] A cement concrete pier foundation 27 is cast 5 to 8 meters from the middle of the side of the cement concrete surface layer 12. A pre-buried ground cage 26 is placed in the cement concrete pier foundation 27, with the anchor bolts of the pre-buried ground cage 26 exposed on the surface of the cement concrete pier foundation 27. The cement concrete pier foundation 27 is allowed to solidify for 3 to 5 days. A probe bracket 23, an infrared sensor probe 22, and a data transmission line 28 are installed on the top of the cylindrical upright 24. After the cement concrete pier foundation 27 hardens, the bottom end of the cylindrical upright 24 is connected to the anchor bolts of the pre-buried ground cage 26 and fixed. An ice and snow status data collection box 25 is installed in the lower middle section of the cylindrical upright 24 using a clamp. The data transmission line 28 is passed through the internal tube of the cylindrical upright 24 and connected to the ice and snow status data collection box 25. A second branch conductor 29 is led out from the ice and snow status data collection box 25 and connected to the power supply of the electrical control box 16, thereby obtaining a non-contact ice and snow status sensing system.

[0069] (7) Connect the heating end wire of the inorganic heat pipe;

[0070] The construction steel formwork of the cement concrete surface layer 12 is removed, the heating rod 5 is installed into the second end 3 of the inorganic heat pipe body 1, and after the heat pipe wire 6 is led out, the sealed cavity 7 in the sealing member 8 outside the second end 3 is sealed with sealant. The heat pipe wire 6 is connected to the electrical control box 16 of the heating control system, and the AC power is introduced into the electrical control box 16.

[0071] (8) Building U-shaped protective trough;

[0072] A U-shaped protective groove 13 is formed by masonry or cement concrete casting, and the temperature sensor wire 19 and the heat pipe wire 6 at the heating end of the inorganic heat pipe are placed in the U-shaped protective groove 13. A prefabricated cover plate 17 is placed on the top surface of the U-shaped protective groove 13 and sealed with potting glue.

[0073] Specific embodiment three: This embodiment provides an operation control method of the inorganic heat pipe electrically heated airport pavement deicing and snow melting system described in specific embodiment one. The method is implemented according to the following steps:

[0074] (1) When snow begins to fall, the AC power supply is turned on, the heating control system is turned on, and the inorganic heat pipe array heats up and operates;

[0075] (2) Turn on the non-contact ice and snow status sensing system to measure and calculate the average snow thickness on the road surface at 1-minute intervals;

[0076] (3) Turn on the pavement internal temperature monitoring sensor assembly and temperature acquisition device, and measure the temperature of a single inorganic heat pipe wall, between two inorganic heat pipes, and the pavement surface at intervals of 10 to 20 minutes;

[0077] (4) Determine the stopping time of the heating process of the inorganic heat pipe electric heating airport pavement deicing and snow melting system, and adopt the following judgment conditions: when the average snow thickness on the pavement is h snow,avg No greater than target snow layer thickness h snow,tgt = 0mm, or when the maximum temperature gradient gardT among all measuring points max Not less than the critical temperature gradient gardT crit =100℃ / m, the heating process of the inorganic heat pipe array stops, and the heating control system switches to regulating the temperature to remain constant; otherwise, the heating control system continues heating operation;

[0078] Average snow thickness on road surface h snow,avg Calculate according to the following formula (1):

[0079]

[0080] Where: n is the number of snow thickness measuring points, h snow,i is the snow elevation at measuring point number i, h dry,i It is the surface elevation of the dry road surface at measuring point number i.

[0081] The maximum temperature gradient between all measuring points gardT max Calculate according to the following formula (2) and formula (3):

[0082] Gard T max =max(gard T j,k )(2)

[0083]

[0084] Where: gardT j,k is the temperature gradient between any two temperature monitoring points numbered j and k, T j is the temperature value at the temperature monitoring point number j, T k is the temperature value at the temperature monitoring point number k, x j and z j are the horizontal and vertical coordinates of the temperature monitoring point number j, respectively, k and z k are the horizontal and vertical coordinates of the temperature monitoring point number k respectively.

[0085] (5) After the snow stops, if the average snow thickness on the road surface is h snow,avg Greater than the target snow layer thickness h snow,tgt = 0mm, follow step (4); if the average snow thickness h snow,tgt Less than target snow layer thickness h snow,tgt = 0mm, the heating control system continues to operate, the inorganic heat pipe array continues to heat up, and the snow melt water on the road surface evaporates;

[0086] (6) To determine the stopping time of the evaporation process of the inorganic heat pipe electric heating airport pavement deicing and snow melting system, the following judgment conditions are adopted: ① When the maximum temperature gradient gardT max Not greater than the critical temperature gradient gardT crit =100℃ / m, if the average water film thickness of the road surface is h water,avg Not greater than the target water film thickness h water,tgt = 0mm, the heating process of the inorganic heat pipe array stops, and the heating control system is shut down, otherwise it returns to step (5); ② When the maximum temperature gradient gardT among all measuring points is max Greater than the critical temperature gradient gardT crit =100℃ / m, the inorganic heat pipe array temperature rise process stops, and the heating control system switches to regulating the temperature to remain constant until the average water film thickness on the road surface reaches h water,avg Less than the target water film thickness h water,tgt =0mm, the heating control system is shut down.

[0087] Average water film thickness on the road surface h water,avg Calculate according to the following formula (4):

[0088]

[0089] Where: m is the number of water film thickness measurement points, h water,t is the water film elevation at measuring point number t, hdry,t It is the surface elevation of the dry road surface at measuring point number t.

[0090] (7) After the heating control system is turned off, the temperature monitoring sensor assembly, temperature acquisition device, and non-contact ice and snow status sensing system stop running, the AC power supply is cut off, and the road surface snow melting operation is completed.

[0091] The operation and control of the inorganic heat pipe electric heating airport pavement deicing and snow melting system has been completed.

[0092] In this embodiment, the operation control method of the inorganic heat pipe electrically heated airport pavement de-icing and snow-melting system utilizes the positive feedback control principle to accurately obtain the pavement de-icing and snow-melting demand by analyzing the ice, snow, and water film status on the pavement surface and the temperature field distribution characteristics inside the pavement. The demand is fed back to the heated pavement feedback control system, and the pavement de-icing and snow-melting system is started and operated. During the operation of the pavement de-icing and snow-melting system, the condition information of weak points on and inside the pavement is monitored in real time. This information is compared with the target value of the de-icing and snow-melting demand to obtain an error result. The system operation state is adjusted in a timely manner according to the error result, and ultimately the operation result of the pavement de-icing and snow-melting system meets the target demand.

[0093] Example:

[0094] This embodiment uses the Ali region of the Tibet Autonomous Region as an example, and uses the following experiments to demonstrate the beneficial effects of the inorganic heat pipe electrically heated airport pavement deicing and snow melting system and its operation control method in a high-altitude cold environment:

[0095] like Figure 13 As shown in the figure, after the inorganic heat pipe electric heating airport pavement de-icing and snow melting system was put into operation, the temperature at different depths of the pavement showed a gradual upward trend. The temperature rose faster near the buried depth of the inorganic heat pipe. The temperature at 5 cm and 8 cm from the pavement surface rose from -5.5°C and -6.5°C to 0°C in about 10 minutes, respectively. The temperature at 2 cm from the pavement surface rose from -8°C to 0°C in 40 minutes.

[0096] like Figure 14 As shown, the initial snow thickness is 2.4 mm. As the snowmelt time increases, the snow thickness on the pavement gradually decreases, exhibiting an initial slow decline phase and a later rapid decline phase. The slow decline phase corresponds to the heating process of the heat pipe, starting and ending at 0 minutes and ending at 125 minutes. The rapid decline phase begins at 125 minutes, and the snow thickness on the pavement decreases linearly and dramatically. As the snow melts, the pavement water film thickness gradually increases, reaching its maximum value after the snow has completely melted. The system then continues to heat up, and the meltwater on the pavement enters the evaporation phase, with the water film thickness gradually decreasing until the pavement is completely dry, marking the end of the heating system's snowmelt process.

[0097] like Figure 15As shown, the deicing and snow melting process of the airport pavement using inorganic heat pipe electric heating performed well on March 15, which can achieve rapid melting of ice and snow on the pavement surface, effectively meeting the deicing and snow melting needs of airport pavements in high-altitude and cold environments.

Claims

1. An inorganic heat pipe electric heating airport pavement deicing and snow melting system, characterized in that The pavement deicing and snow melting system includes an inorganic heat pipe assembly, an electrically heated airport pavement structure, and a feedback control system, wherein: The inorganic heat pipe assembly consists of a single inorganic heat pipe body, a heating rod and a sealing structure; The electrically heated airport pavement structure is composed of a cement-stabilized crushed stone base layer, a cement concrete surface layer, an inorganic heat pipe array, and an inorganic heat pipe support grid. The feedback control system consists of a pre-buried temperature monitoring sensor assembly, a temperature acquisition device, a non-contact ice and snow state sensing system, and a heating control system; The non-contact ice and snow state sensing system consists of an infrared sensor probe, a probe bracket, a cylindrical pole, an ice and snow state data collection box, a pre-buried ground cage, a cement concrete pier foundation, and a data transmission line; The heating control system includes an electric control box, a heat pipe wire, a first branch wire, and a second branch wire; The first and second ends of the inorganic heat pipe body are sealed, a heat pipe cavity is formed in the pipe, and the heat pipe cavity is filled with a heat transfer medium. A heating rod is provided at the second end of the inorganic heat pipe body, and the heating rod is connected to the heat pipe wire. A sealed cavity is provided at the connection between the heating rod and the heat pipe wire, and the sealed cavity is provided in a sealing member, which is connected to a sealing plug to form a sealed structure. The inorganic heat pipe support grid is composed of horizontal support steel bars and vertical support steel bars. One end of the vertical support steel bar is embedded in the cement-stabilized gravel base, and the other end is welded to the horizontal support steel bar. The inorganic heat pipe array is composed of multiple inorganic heat pipe components. The multiple inorganic heat pipe components are arranged in parallel at equal intervals on the horizontal support steel bars to form an array heating structure. The heat pipe wires are connected to the electrical control box. The temperature monitoring sensor assembly includes several temperature sensors, which are arranged on the surface of the cement concrete surface layer, at both ends of the inorganic heat pipe body, in the middle of the inorganic heat pipe body, and at 1 / 2 of the distance between two inorganic heat pipe bodies; The temperature sensor is connected to the temperature acquisition device via a sensor wire, and the temperature acquisition device is connected to the electric control box via a first branch wire to realize power supply; The pre-buried cage is buried in the cement concrete pier foundation, the bottom of the cylindrical pole is fixed to the anchor bolt exposed by the pre-buried cage, an ice and snow status data collection box is installed on the middle and lower sections of the cylindrical pole, a probe bracket is installed on the top of the cylindrical pole, an infrared sensor probe is installed at the front end of the probe bracket, the infrared sensor probe is connected to the ice and snow status data collection box through a data transmission line, and the ice and snow status data collection box is connected to the power supply inside the electric control box through a second branch wire; The electric control box controls the connection and disconnection of the heat pipe wire, the first branch wire, and the second branch wire respectively through the circuit switch.

2. The inorganic heat pipe electrically heated airport pavement deicing and snow melting system according to claim 1 is characterized in that The inorganic heat pipe body is placed obliquely with an inclination of 1-2%, and the end containing the heating rod is slightly lower.

3. The inorganic heat pipe electrically heated airport pavement deicing and snow melting system according to claim 1 or 2, characterized in that The inorganic heat pipe has a diameter of 28-32 cm and a length of 4.0 m. The outer pipe is made of a corrosion-resistant carbon steel alloy. The first end and the second end are sealed with a low thermal conductivity material.

4. The inorganic heat pipe electrically heated airport pavement deicing and snow melting system according to claim 1 is characterized in that The sealing cavity is filled with sealant, a rubber ring is provided between the sealing member and the sealing plug, and the sealing member and the sealing plug are connected by threads.

5. The inorganic heat pipe electrically heated airport pavement deicing and snow melting system according to claim 1 is characterized in that A U-shaped protective groove is provided at the edge of the cement concrete surface layer, and the temperature sensor wire and the heat pipe wire are placed in the U-shaped protective groove.

6. The inorganic heat pipe electrically heated airport pavement deicing and snow melting system according to claim 5 is characterized in that The U-shaped protection trough is cast with cement concrete or built with bricks and stones, and a prefabricated cover plate is provided on the top of the trough.

7. An operation control method for an inorganic heat pipe electrically heated airport pavement deicing and snow melting system according to any one of claims 1 to 6, characterized in that The method comprises the following steps: Step (1) When snow begins to fall, the AC power supply is connected, the heating control system is turned on, the inorganic heat pipe array is operated, and the electric heating of the airport pavement structure is heated; Step (2) turning on the non-contact ice and snow state sensing system to measure and calculate the average snow thickness on the road surface at 1-minute intervals; Step (3) turning on the pavement internal temperature monitoring sensor assembly and the temperature acquisition device, and measuring the temperature of a single inorganic heat pipe wall, between two inorganic heat pipes, and the pavement surface at intervals of 10 to 20 minutes; Step (4) determines the stopping time of the heating process of the inorganic heat pipe electric heating airport pavement deicing and snow melting system, and adopts the following judgment conditions: when the average snow thickness on the pavement is h snow,avg No greater than the target snow layer thickness h snow,tgt , or when the maximum temperature gradient among all measuring points Gard T max Not less than the critical temperature gradient Gard T crit When the inorganic heat pipe array temperature rise process stops, the heating control system switches to regulating the temperature to remain constant, otherwise the heating control system continues heating operation, wherein: h snow,tgt =0mm, T crit =100℃ / m; Step (5) After the snow stops, if the average snow thickness on the road surface is h snow,avg Greater than target snow layer thickness h snow,tgt , follow step (4); if the average snow thickness on the road is h snow,tgt Less than target snow layer thickness h snow,tgt , the heating control system continues to operate, the inorganic heat pipe array continues to heat up, and evaporates the snow melt water on the road surface; Step (6) determines the stopping time of the evaporation process of the inorganic heat pipe electric heating airport pavement deicing and snow melting system, and adopts the following judgment conditions: ① When the maximum temperature gradient between all measuring points Gard T max Not greater than the critical temperature gradient Gard T crit If the average water film thickness of the pavement is satisfied h water,avg Not greater than the target water film thickness h water,tgt , the inorganic heat pipe array heating process stops, and the heating control system shuts down. Otherwise, the process returns to step (5), where: Gard T crit =100℃ / m, h water,tgt =0mm;②When the highest temperature gradient among all measuring points Gard T max Greater than the critical temperature gradient Gard T crit When the inorganic heat pipe array temperature rise process stops, the heating control system switches to regulating the temperature to remain constant until the average water film thickness on the road surface reaches h water,avg Less than target water film thickness h water,tgt , the heating control system is shut down; After the heating control system is turned off in step (7), the temperature monitoring sensor assembly, the temperature acquisition device, and the non-contact ice and snow state sensing system stop running, the AC power supply is cut off, and the road surface snow melting operation is completed.

8. The operation control method of the inorganic heat pipe electrically heated airport pavement deicing and snow melting system according to claim 7 is characterized in that Average snow thickness on the road surface h snow,avg Calculated according to the following formula: Where: n is the number of snow thickness measurement points, h snow,i Number the measuring point i The snow elevation at h dry,i Number the measuring point i The surface elevation of the road surface in dry conditions.

9. The operation control method of the inorganic heat pipe electrically heated airport pavement deicing and snow melting system according to claim 7 is characterized in that The maximum temperature gradient between the measuring points Gard T max Calculated according to the following formula: Where: Gard T j,k Number any two temperature monitoring points j and k The temperature gradient between T j Number the temperature monitoring point j The temperature value at T k Number the temperature monitoring point k The temperature value at x j and z j Temperature monitoring point numbers j The horizontal and vertical coordinates of x k and z k Temperature monitoring point numbers k The horizontal and vertical coordinates of .

10. The operation control method of the inorganic heat pipe electrically heated airport pavement deicing and snow melting system according to claim 7 is characterized in that The average water film thickness of the road surface h water,avg Calculated according to the following formula: Where: m is the number of water film thickness measurement points, h water,t Number the measuring point t The water film elevation at h dry,t Number the measuring point t The surface elevation of the road surface in dry conditions.

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