Intelligent ventilation temperature control system and temperature control method for driven pipe pile in permafrost region

Abstract

The invention discloses an intelligent ventilation and temperature control system and method for a driven-type pipe pile in a permafrost region, the intelligent ventilation and temperature control system comprises a low-temperature air conveying unit, an exhaust unit and an automatic intelligent control unit, and the automatic intelligent control unit controls the low-temperature air conveying unit to convey cold air into the pipe pile; the exhaust unit exhausts hot air in the pipe pile, and cold and hot alternate circulation of outside air and air in the pipe pile is achieved. According to the system, through an intelligent cold / warm season regulation and control mechanism, the thermal erosion process of a pile-soil interface is blocked in a low-energy-consumption, high-efficiency and high-environment-friendly mode, the thermal stability of a permafrost foundation around the pile is maintained, the bearing performance of a foundation structure is enhanced, and therefore long-term safe and stable operation of foundation engineering in the cold region is guaranteed.

Description

Technical Field

[0001] The present invention relates to the cross - technical field of permafrost area foundation engineering and mechanical ventilation, and particularly to an intelligent ventilation temperature control system and temperature control method for driven pipe piles in permafrost areas. Background Art

[0002] Under the dual influence of global climate warming and human engineering activities, the thermal equilibrium state of permafrost foundations is undergoing significant changes. Observation data shows that the degree and rate of permafrost degradation are intensifying, and the resulting thaw settlement deformation has seriously threatened the safety and service stability of cold - region engineering structures. Especially in linear engineering fields such as railways and highways, the non - uniform settlement caused by the melting of permafrost foundations not only affects the riding comfort of vehicles but also significantly increases the maintenance cost. Therefore, improving the thermal stability and mechanical bearing capacity of permafrost foundations has become a key technical requirement for ensuring the long - term safe operation of cold - region linear projects.

[0003] As an important innovative engineering measure for strengthening permafrost foundations, driven pipe piles are pre - fabricated hollow pipe piles that are penetrated into the target formation by means of hammering, vibration or static pressure. Due to its construction convenience and good load transfer characteristics, this technology is widely used in foundation engineering. However, existing conventional driven pipe piles lack the function of actively regulating the ground temperature field around the pile, and it is difficult to effectively inhibit the thermo - mechanical coupling instability problem caused by permafrost degradation. Specifically, there are two key defects: First, during the construction stage, the pile penetration process generates significant thermal disturbances, breaking the original ground temperature field distribution pattern; Second, during the operation period, superimposed on the impact of global warming, the continuous thermal erosion effect triggers the non - equilibrium heat exchange process at the pile - soil interface, inducing thermal erosion of the permafrost around the pile, significantly weakening the freezing bond strength and side friction resistance at the pile - soil interface, leading to the deterioration of pile foundation bearing capacity and the aggravation of settlement deformation, and ultimately causing irreversible deformation of the engineering structure.

[0004] Therefore, based on the above - mentioned technical bottlenecks, the current engineering community urgently needs to develop an active intelligent temperature control system suitable for driven pipe piles with strong environmental adaptability. Through innovative structural design, this system needs to achieve dynamic regulation of the heat exchange process at the pile - soil interface, and fundamentally improve the problem of the decline in the service performance of permafrost foundations in cold - region projects under the background of climate change, while meeting multiple constraints such as the real - time nature of environmental heat regulation and the economic efficiency of operation and maintenance. Summary of the Invention

[0005] The purpose of the present invention is to provide an intelligent ventilation temperature control system for driven pipe piles in permafrost areas to address the technical defects existing in the prior art.

[0006] Another purpose of the present invention is to provide a temperature control method for the above - mentioned intelligent ventilation temperature control system.

[0007] The technical solution adopted to achieve the purpose of the present invention is as follows: An intelligent ventilation and temperature control system for driven pipe piles in permafrost regions, comprising a low-temperature air transportation unit, an exhaust unit, and an automatic intelligent control unit. The automatic intelligent control unit controls the low-temperature air transportation unit to transport cold air into the pipe piles, and the exhaust unit discharges the hot air in the pipe piles, realizing the cold and hot alternating cycle of the external air and the internal air of the pipe piles in the cold season; The automatic intelligent control unit includes a first control circuit and a second control circuit connected in parallel with a low-voltage power supply. A first temperature thermistor and a first resistor are connected in series on the first control circuit, and a second temperature thermistor and a second resistor are connected in series on the second control circuit. The first control circuit is connected to the negative pole of a voltage comparator, and the second control circuit is connected to the positive pole of the voltage comparator. The control terminal of the voltage comparator is connected to a relay through an NPN-type triode, and the relay controls the on-off of a louver motor. The louver motor is opened in the cold season, and the low-temperature air transportation unit transports cold air into the pipe piles. The louver motor is closed in the warm season, and the low-temperature air transportation unit stops transporting air; In the above technical solution, the number of the low-temperature air transportation units is at least one group. Each group of the low-temperature air transportation units includes an air delivery pipeline, an air inlet device, and a plurality of vertical air delivery pipelines in the pile body. Each of the vertical air delivery pipelines in the pile body is vertically arranged in a pipe pile, and its top end is communicated with the air delivery pipeline. One end of the air delivery pipeline is communicated with the outside through the air inlet device, and the other end is communicated with the top of a vertical air delivery pipeline in the pile body. The tops of the remaining vertical air delivery pipelines in the pile body are all communicated with the pipe body of the air delivery pipeline; In the above technical solution, an arc-shaped diversion elbow is installed at the end of the air delivery pipeline communicated with the outside. The arc-shaped diversion elbow opens downward, and an air inlet device is installed at the opening of the arc-shaped diversion elbow; In the above technical solution, the air inlet of the air inlet device is set in a horn shape; In the above technical solution, the number of the exhaust units is the same as that of the low-temperature air transportation units. Each group of low-temperature air transportation units is matched with a group of low-temperature air transportation units to realize the cold and hot alternating cycle of the external air and the internal air of the pipe piles; In the above technical solution, each group of the exhaust units includes a second main exhaust pipeline, a first main exhaust pipeline arranged in the subgrade, and a plurality of exhaust branch pipelines. One end of each exhaust branch pipeline is communicated with the pile cap of the pipe pile, and the other end is communicated with the horizontally arranged first main exhaust pipeline. One end of the second main exhaust pipeline is communicated with the first main exhaust pipeline, and the other end is communicated with the outside through a power-free wind cap; In the above technical solution, the height of the air inlet of the air inlet device is lower than the height of the air outlet of the power-free wind cap; In the above technical solution, the air inlet device includes a louver motor, the louver motor is installed in the circuit integration box, the first temperature thermistor is arranged at the air inlet of the air inlet device, and the second temperature thermistor is arranged on the inner wall of the upper part of the pipe pile; In the above technical solution, a solar panel is installed on the top surface of the circuit integration box to supply power to the automatic intelligent control unit.

[0008] Another aspect of the present invention also includes a temperature control method for the intelligent ventilation and temperature control system of the driven pipe pile in the permafrost region, comprising the following steps: When the outside temperature is lower than the permafrost foundation temperature, the resistance value of the first temperature thermistor is higher than that of the second temperature thermistor, the voltage at the positive pole of the voltage comparator increases, the voltage comparator outputs a high level, the NPN type triode conducts current, the relay is energized and connected to its normally open contact, the louver motor opens, and at the same time the indicator light goes out. The outside cold air is conveyed into the pipe pile through the air delivery pipeline and the vertical air delivery pipe, and at the same time the warm air in the pipe pile cavity is discharged to the outside through the first exhaust main pipeline and the second exhaust main pipeline to reduce the temperature in the pipe pile cavity; When the outside temperature is higher than the permafrost foundation temperature, the resistance value of the first temperature thermistor is lower than that of the second temperature thermistor, the voltage at the positive pole of the voltage comparator decreases, the voltage comparator outputs a low level, the NPN type triode cuts off the current, the relay is de-energized and connected to its normally closed contact, the louver motor stops rotating, and the indicator light becomes bright to prevent the outside warm air from entering the pipe pile cavity.

[0009] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. The system of the present invention includes a low-temperature air transportation unit, an exhaust unit and an automatic intelligent control unit. The automatic intelligent control unit automatically regulates the opening and closing of the low-temperature air transportation unit according to the difference between the outside air temperature and the temperature in the pipe pile, realizes opening the air inlet channel in the cold season, cold air enters the pipe pile cavity, and the exhaust unit continuously discharges the air in the pipe pile cavity, enhances the heat exchange efficiency of the outside low-temperature air in the pipe pile cavity, and realizes the heat discharge in the driven pipe pile cavity; in the warm season, the air inlet channel is closed to prevent warm air from entering the pipe pile cavity; 2. The system of the present invention blocks the heat erosion process at the pile-soil interface in a low-energy consumption, high-efficiency and high-environmental protection manner through an intelligent cold / warm season regulation mechanism, maintains the thermal stability of the permafrost foundation around the pile, enhances the bearing performance of the foundation structure, and thus ensures the long-term safe and stable operation of the cold region foundation project. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 It is a schematic structural sectional view of the intelligent ventilation and temperature control system of the driven pipe pile in the permafrost region of the present invention.

[0011] Figure 2 This is a top view of the positions of the exhaust branch pipeline, the vertical air duct inside the pile body, and the pile cap in the intelligent ventilation and temperature control system of the driven pipe pile in the permafrost area of the present invention.

[0012] Figure 3 This is a circuit schematic diagram of the automatic intelligent control unit in the intelligent ventilation and temperature control system of the driven pipe pile in the permafrost area of the present invention.

[0013] Wherein: 1: Highway pavement without a central divider, 2: Subgrade, 3: Exhaust branch pipeline, 4-1: First main exhaust pipeline, 4-2: Second main exhaust pipeline, 5: Unpowered wind cap, 6: Air delivery pipeline, 7: Arc-shaped diversion elbow, 8: Air inlet device, 9: Pile cap, 10: Pipe pile, 11: Vertical air delivery pipeline inside the pile body, 12: Foundation, 13: Circuit integration box, 15: Low-voltage power supply, 16: First temperature thermistor, 17: Second temperature thermistor, 18: First resistor, 19: Second resistor, 20: Voltage comparator, 21: NPN-type triode, 22: Relay, 23: Indicator light, 24: Louver motor, 25: High-voltage power supply. Specific embodiments

[0014] The present invention will be further described in detail below in conjunction with specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0015] Embodiment 1 As Figure 1 - Figure 2 shown, an intelligent ventilation and temperature control system for a driven pipe pile in a permafrost area includes a low-temperature air transportation unit, an exhaust unit, and an automatic intelligent control unit. The automatic intelligent control unit controls the low-temperature air transportation unit to transport cold air into the pipe pile 10, and the exhaust unit discharges the hot air in the pipe pile 10 to achieve the cold and hot alternating cycle of the outside air and the air inside the pipe pile 10 in the cold season. When the outside temperature is lower than the temperature of the permafrost foundation 12, the automatic intelligent control unit controls the low-temperature air transportation unit to open and transports the outside cold air into the pipe pile 10. At the same time, the exhaust unit discharges the warm air in the cavity of the pipe pile 10 to the outside to reduce the temperature in the cavity of the pipe pile 10. When the outside temperature is higher than the temperature of the permafrost foundation 12, the automatic intelligent control unit controls the low-temperature air transportation unit to close to prevent the outside warm air from entering the cavity of the pipe pile 10.

[0016] The number of the low-temperature air transportation units is at least one group. Each group of the low-temperature air transportation units includes an air delivery pipe 6, an air inlet device 8, and a plurality of vertical air delivery pipes 11 inside the piles. Each of the vertical air delivery pipes 11 inside the piles is vertically arranged in a pipe pile 10. The bottom air outlet of each vertical air delivery pipe 11 inside the pile is spaced from the bottom of the pipe pile 10, and the two are about 20 cm apart. The top of each vertical air delivery pipe 11 inside the pile is communicated with the air delivery pipe 6. One end of the air delivery pipe 6 is communicated with the outside through the air inlet device 8, and the other end is communicated with the top of a vertical air delivery pipe 11 inside the pile. The tops of the remaining vertical air delivery pipes 11 inside the piles are all communicated with the pipe body of the air delivery pipe 6. The air inlet device 8 conveys the outside cold air to the inside of the pipe pile 10 through the air delivery pipe 6 and the vertical air delivery pipes 11 inside the piles in sequence, exchanges heat with the permafrost area foundation 12, reduces the temperatures of the pipe pile 10 and the permafrost area foundation 12, and achieves the purpose of weakening the thermal erosion at the pile-soil interface.

[0017] Further, an arc-shaped diversion elbow 7 is installed at the end of the air delivery pipe 6 communicated with the outside. The arc-shaped diversion elbow 7 has an opening facing downwards. The air inlet device 8 is installed at the opening of the arc-shaped diversion elbow 7. The air inlet device 8 includes a louver motor 24, and the air inlet or non-air inlet is realized by controlling the on-off of the louver motor 24. The air inlet of the air inlet device 8 is set in a horn shape to avoid the influence of adverse factors such as sand, rain / snow, etc. on the smoothness of the air inlet.

[0018] Further, the central axis of the vertical air delivery pipe 11 inside the pile coincides with the central axis of the pipe pile 10.

[0019] The number of the exhaust units is the same as that of the low-temperature air transportation units. Each group of low-temperature air transportation units is matched with a group of low-temperature air transportation units to realize the cold and hot alternating cycle of the outside air and the air inside the pipe pile 10. The exhaust unit includes a second exhaust main pipe 4-2, a first exhaust main pipe 4-1 arranged in the roadbed 2 (the roadbed 2 is arranged under the highway pavement 1 without a central divider), and a plurality of exhaust branch pipes 3. One end of each exhaust branch pipe 3 is communicated with the pile cap 9 (the cross-section of the pile cap 9 is square) of the pipe pile 10, and the other end of each exhaust branch pipe 3 is communicated with the horizontally arranged first exhaust main pipe 4-1. The diameter of the exhaust branch pipe 3 is much smaller than the diameter of the pile cap 9, and it will not affect the mechanical bearing function of the pile cap 9. In this embodiment, two exhaust branch pipes 3 are installed on the pile cap 9 of each pipe pile 10. The axes of the two exhaust branch pipes 3 are parallel to the axis of the vertical air transportation pipe 11 in the pile body and are in the same plane. The axis of the exhaust branch pipe 3 is parallel to the axis of the pipe pile 10, and the distance between the axis of each exhaust branch pipe 3 and the axis of the pipe pile 10 is half of the radius of the pipe pile 10. One end of the second exhaust main pipe 4-2 is communicated with the first exhaust main pipe 4-1, and the other end is communicated with the outside through a non-powered wind cap 5. The end opening of the second exhaust main pipe 4-2 faces upward. The non-powered wind cap 5 discharges the hot air in the pipe pile 10 to the external environment through the first exhaust main pipe 4-1, the exhaust branch pipe 3 and the second exhaust main pipe 4-2 in sequence.

[0020] Further, the air inlet height of the air inlet device 8 is lower than the air outlet height of the non-powered wind cap 5.

[0021] As Figure 3 shown, the automatic intelligent control unit includes a first control circuit and a second control circuit connected in parallel with the low-voltage power supply 15. A first temperature thermistor 16 and a first resistor 18 are connected in series on the first control circuit, and a second temperature thermistor 17 and a second resistor 19 are connected in series on the second control circuit. The first control circuit is connected to the negative electrode (“-” terminal) of the voltage comparator 20, and the second control circuit is connected to the positive electrode of the voltage comparator 20. The voltage comparator 20 is used to compare the voltages of the first control circuit and the second control circuit. The control terminal of the voltage comparator 20 is connected to the relay 22 through an NPN-type triode 21. The relay 22 controls the on-off of the shutter motor 24 of the air inlet device 8. The first temperature thermistor 16 is arranged at the air inlet of the air inlet device 8, and the second temperature thermistor 17 is arranged on the inner wall of the upper part of the pipe pile 10. Except for the first temperature thermistor 16 and the second temperature thermistor 17, the rest of the automatic intelligent control unit is installed in a circuit integration box 13. A solar panel is installed on the top surface of the circuit integration box 13 to supply power to the automatic intelligent control unit.

[0022] Further, the circuit integration box 13 is made of iron sheet, which can function to prevent wind, water / snow, etc.

[0023] Embodiment 2 Based on Embodiment 1, this embodiment provides a working method for the automatic intelligent control unit, including the following steps: When the outside temperature is higher than the temperature of the permafrost area foundation 12, the resistance value of the first temperature thermistor 16 is less than that of the second temperature thermistor 17, the voltage at the positive pole (“+” terminal) of the voltage comparator 20 decreases, the voltage comparator 20 outputs a low level, the NPN-type triode 21 cuts off the current, the relay 22 is powered off and connected to its normally closed contact, the shutter motor 24 closes and stops rotating, and the indicator light 23 becomes bright.

[0024] When the outside temperature is lower than the temperature of the permafrost foundation 12, the resistance value of the first temperature thermistor 16 is higher than that of the second temperature thermistor 17, the voltage at the “+” terminal of the voltage comparator 20 increases, the voltage comparator 20 outputs a high level, the NPN-type triode 21 conducts current, the relay 22 is powered on and connected to its normally open contact, the shutter motor 24 opens and runs, and the indicator light 23 goes out.

[0025] Further, the high-voltage power supply 25 is connected in series with either the shutter motor 24 or the indicator light 23. When the relay 22 controls the shutter motor 24 to open, the shutter motor 24 is powered by the high-voltage power supply 25. When the relay 22 controls the indicator light 23 to open, the indicator light 23 is powered by the high-voltage power supply 25.

[0026] Embodiment 3 Based on Embodiment 1 and Embodiment 2, this embodiment provides a temperature control method for the intelligent ventilation and temperature control system of the driven pipe pile in the permafrost area, including the following steps: When the outside temperature is lower than the temperature of the permafrost area foundation 12, the shutter motor 24 opens, and the outside cold air is transported into the pipe pile 10 through the air delivery pipeline 6 and the vertical air delivery pipeline 11 in the pile body. At the same time, the warm air in the cavity of the pipe pile 10 is discharged to the outside through the first exhaust main pipeline 4-1 and the second exhaust main pipeline 4-2 to reduce the temperature in the cavity of the pipe pile 10. When the outside temperature is higher than the temperature of the permafrost area foundation 12, the shutter motor 24 closes to prevent the outside warm air from entering the cavity of the pipe pile 10.

[0027] The above are only the preferred embodiments of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and refinements can be made, and these improvements and refinements should also be regarded as the protection scope of the present invention.

Claims

1. An intelligent ventilation and temperature control system for driven pipe piles in permafrost regions, characterized in that, It includes a low-temperature air transportation unit, an exhaust unit, and an automatic intelligent control unit. The automatic intelligent control unit controls the low-temperature air transportation unit to transport cold air into the pipe pile, and the exhaust unit discharges the hot air in the pipe pile, realizing the cold and hot alternating cycle of the external air and the air inside the pipe pile in the cold season. The automatic intelligent control unit includes a first control circuit and a second control circuit connected in parallel with a low-voltage power supply. A first temperature thermistor and a first resistor are connected in series on the first control circuit, and a second temperature thermistor and a second resistor are connected in series on the second control circuit. The first control circuit is connected to the negative pole of a voltage comparator, and the second control circuit is connected to the positive pole of the voltage comparator. The control terminal of the voltage comparator is connected to a relay through an NPN-type triode, and the relay controls the on-off of the shutter motor. When the shutter motor is opened, the low-temperature air transportation unit transports low-temperature air into the pipe pile. When the shutter motor is closed, the low-temperature air transportation unit stops transporting low-temperature air.

2. The intelligent ventilation and temperature control system according to claim 1, wherein The number of the low-temperature air transportation units is at least one group. Each group of the low-temperature air transportation units includes an air delivery pipe, an air inlet device, and a plurality of vertical air delivery pipes in the pile body. Each vertical air delivery pipe in the pile body is vertically arranged in a pipe pile. The top end of each vertical air delivery pipe in the pile body is communicated with the air delivery pipe. One end of the air delivery pipe is communicated with the outside through the air inlet device. One end of the air delivery pipe is communicated with the top of a vertical air delivery pipe in the pile body, and the tops of the remaining vertical air delivery pipes in the pile body are communicated with the pipe body of the air delivery pipe.

3. The intelligent ventilation and temperature control system according to claim 2, characterized in that, An arc-shaped diversion elbow is installed at the end of the air delivery pipe communicated with the outside. The arc-shaped diversion elbow opens downward, and the air inlet device is installed at the opening of the arc-shaped diversion elbow.

4. The intelligent ventilation and temperature control system according to claim 2, wherein The air inlet of the air inlet device is set in a horn shape.

5. The intelligent ventilation and temperature control system according to claim 4, characterized in that, The number of the exhaust units is the same as that of the low-temperature air transportation units. Each group of low-temperature air transportation units is matched with a group of low-temperature air transportation units to realize the cold and hot alternating cycle of the external air and the air inside the pipe pile in the cold season.

6. The intelligent ventilation and temperature control system according to claim 5, wherein Each group of the exhaust units includes a second main exhaust pipe, a first main exhaust pipe arranged in the subgrade, and a plurality of exhaust branch pipes. One end of each exhaust branch pipe is communicated with the pile cap of the pipe pile, and the other end is communicated with the horizontally arranged first main exhaust pipe. One end of the second main exhaust pipe is communicated with the first main exhaust pipe, and the other end is communicated with the outside through a power-free wind cap.

7. The intelligent ventilation and temperature control system according to claim 6, characterized in that, The height of the air inlet of the air inlet device is lower than the height of the air outlet of the power-free wind cap.

8. The intelligent ventilation and temperature control system according to claim 2, wherein, The air inlet device includes a shutter motor. The shutter motor is installed in the circuit integration box. The first temperature thermistor is arranged at the air inlet of the air inlet device, and the second temperature thermistor is arranged on the inner wall of the upper part of the pipe pile.

9. The intelligent ventilation and temperature control system according to claim 8, wherein A solar panel is installed on the top surface of the circuit integration box to supply power to the automatic intelligent control unit.

10. The temperature control method of the intelligent ventilation temperature control system according to any one of claims 6 to 9, characterized in that, It includes the following steps: When the outside temperature is lower than the temperature of the foundation in the permafrost area, the resistance value of the first temperature thermistor is higher than that of the second temperature thermistor. The voltage at the positive terminal of the voltage comparator increases, and the voltage comparator outputs a high level. The NPN-type triode conducts current, the relay is energized and connected to its normally open contact, the shutter motor opens, and at the same time the indicator light goes out. The outside cold air is transported into the pipe pile through the air delivery pipeline and the vertical air delivery pipeline in the pile body. At the same time, the warm air in the pipe pile cavity is discharged to the outside through the first main exhaust pipeline and the second main exhaust pipeline to reduce the temperature in the pipe pile cavity. When the outside temperature is higher than the temperature of the foundation in the permafrost area, the resistance value of the first temperature thermistor is lower than that of the second temperature thermistor. The voltage at the positive terminal of the voltage comparator decreases, and the voltage comparator outputs a low level. The NPN-type triode cuts off the current, the relay is de-energized and connected to its normally closed contact, the shutter motor stops rotating, and the indicator light becomes bright, preventing the outside warm air from entering the pipe pile cavity.

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