Tunnel geothermal anti-freezing system based on energy piles

Abstract

The invention discloses a tunnel terrestrial heat anti-freezing system based on energy piles, and relates to the technical field of tunnel terrestrial heat anti-freezing, the tunnel terrestrial heat anti-freezing system comprises a tunnel, a heat exchanger in the tunnel, a heat pump unit and multiple groups of tunnel energy piles, the multiple groups of tunnel energy piles are connected with a heat exchanger in a tunnel pile foundation; the reinforced concrete pile body of the tunnel energy pile wraps the second heat exchange pipe, the effects of heat absorption and bearing are achieved, the second heat exchange pipe is embedded in the pile foundation and connected with the heat pump system, the heat pump system is arranged in the heat exchange pipe, and the heat pump system is arranged in the heat exchange pipe. The tunnel energy pile exchanges heat with surrounding soil, the heat pump unit circulates heat to achieve the expected tunnel heat preservation effect, the heat exchange pipe in the lining continuously supplies heat to the interior of the tunnel, and the tunnel energy pile foundation serves as a heat exchange well, so that the well digging link of a ground source heat pump system can be reduced, and the heat exchange efficiency is improved. And the grouting backfilling procedure of the heat exchange well can be reduced.

Description

Technical Field

[0001] The invention relates to the technical field of tunnel geothermal antifreeze, and in particular to a tunnel geothermal antifreeze system based on energy piles. Background Art

[0002] Tunnels are an important type of transportation infrastructure, usually used to cross mountains, water bodies or other obstacles to provide convenient transportation channels. During the construction and operation of tunnels, antifreeze measures are an important part of ensuring the safety and smooth operation of tunnels. Traditional tunnel antifreeze methods mainly rely on electric heating and infrared heating.

[0003] The electric heating method converts electrical energy into thermal energy for heating to achieve the purpose of antifreeze. Although this method is simple and direct, it consumes a lot of energy and produces a lot of greenhouse gas emissions, which is not in line with the concept of green and environmentally friendly energy utilization.

[0004] The infrared heating method uses an infrared generator to heat the construction lining with sealed radiation to achieve the antifreeze effect. This method has a high heating efficiency, but the heating range is limited. In addition, for the antifreeze needs of long-distance and large-space tunnels, it is difficult to implement and the cost is relatively high.

[0005] On the other hand, as a green and efficient way of utilizing energy, the ground source heat pump system has been widely used in the field of geothermal energy utilization. However, the application of traditional horizontal or vertical ground source heat pump systems in tunnel antifreeze is limited. The horizontal ground source heat pump system requires a large horizontal space for laying, which is difficult to implement in a space-limited environment such as a tunnel. Although the vertical ground source heat pump system can save horizontal space, it requires special drilling construction, which increases the construction cost and difficulty.

[0006] In view of the shortcomings of the above-mentioned traditional antifreeze methods and the limitations of ground source heat pump systems in tunnel antifreeze applications, a new, efficient and environmentally friendly tunnel antifreeze system is urgently needed to meet actual needs. Therefore, the present invention proposes a tunnel geothermal antifreeze system based on energy piles, which combines the advantages of energy piles and geothermal energy, aiming to provide a green, clean and recyclable antifreeze solution. Summary of the invention

[0007] The present invention provides a tunnel geothermal antifreeze system based on energy piles, which solves the above-mentioned technical problems.

[0008] In order to solve the above technical problems, the present invention provides a tunnel geothermal antifreeze system based on energy piles, comprising a tunnel, a heat exchanger in the tunnel, a heat pump unit and a plurality of groups of tunnel energy piles, wherein the plurality of groups of tunnel energy piles are connected to a heat exchanger in a tunnel pile foundation, and the heat exchanger in the tunnel, the heat pump unit and the heat exchanger in the tunnel pile foundation are connected in a pipeline circulation manner;

[0009] The heat exchanger in the tunnel pile foundation includes two circulating pumps, two valves and two heat exchange tubes installed inside each group of tunnel energy piles. The water inlet and outlet ends of the plurality of heat exchange tubes are connected in parallel through pipelines. The water outlet parallel pipeline is connected to the input end of the two circulating pumps. The pipeline at the output end of the two circulating pumps is connected to the heat pump unit. The water inlet parallel pipeline is connected to the output end of the two valves. The pipeline at the input end of the two valves is connected to the heat pump unit.

[0010] The tunnel comprises surrounding rock and lining, and the heat exchanger part in the tunnel is installed between the surrounding rock and the lining and connected with the pipeline of the heat pump unit.

[0011] Furthermore, the heat exchanger in the tunnel includes multiple groups of heat exchange tubes, a circulating pump and a valve. The multiple groups of heat exchange tubes are laid and installed between the surrounding rock and the lining. The water inlet and outlet ends of the multiple groups of heat exchange tubes are connected in parallel through pipes, wherein the water outlet parallel pipe is connected to the input end of valve one, and the output end of valve one is connected to the water output end pipe of the condenser. The water inlet parallel pipe is connected to the output end of valve one, and the input end of valve one is connected to the water output end pipe of the condenser.

[0012] Furthermore, the tunnel energy pile is a reinforced concrete pile, and the heat exchange tube 2 is fixed in the steel cage of the tunnel energy pile by binding.

[0013] Furthermore, the steel cage and heat exchange tube 2 of the tunnel energy pile are buried underground at a specified depth through drilling, and backfilled with soil to the pile bottom elevation, and poured with concrete to form.

[0014] Furthermore, the heat pump unit includes an evaporator, a gas-liquid separator, a compressor, an oil separator, a condenser, an electronic expansion valve, a filter and a liquid receiver. The water-liquid output end pipeline of the evaporator is connected to the second input end of the valve, the water-liquid input end pipeline of the evaporator is connected to the second output end of the circulation pump, the medium output end pipeline of the evaporator is connected to the gas-liquid separator input end, the gas-liquid separator output end pipeline is connected to the compressor input end, the compressor output end pipeline is connected to the oil separator input end, the oil separator output end pipeline is connected to the condenser medium input end, the condenser medium output end pipeline is connected to the liquid receiver input pipe, the liquid receiver output end pipeline is connected to the filter input end, the filter output end pipeline is connected to the electronic expansion valve input end, and the electronic expansion valve output end pipeline is connected to the evaporator medium input end.

[0015] Compared with the related art, the tunnel geothermal antifreeze system based on energy piles provided by the present invention has the following beneficial effects:

[0016] The present invention provides that the reinforced concrete pile body of the tunnel energy pile wraps the heat exchange pipe 2 to play the role of absorbing heat and bearing, the heat exchange pipe 2 is buried in the pile foundation and connected to the heat pump system, the tunnel energy pile and the surrounding soil exchange heat, the heat pump unit circulates the heat to achieve the expected insulation tunnel effect, the heat exchange pipe in the lining continuously heats the inside of the tunnel, and the pile foundation of the tunnel energy pile is used as a heat exchange well, which can reduce the well drilling process of the ground source heat pump system and the grouting backfilling process of the heat exchange well.

[0017] Compared with the traditional electric heating method and infrared heating method, the present invention is connected to the tunnel energy pile, the heat source is green, clean and recyclable geothermal energy, which can reduce the emission of greenhouse gases and has the conditions of heating snowmelt in advance and heating snowmelt in real time.

[0018] Compared with horizontal or vertical ground source heat pump systems, the present invention provides that because the construction of tunnel energy piles itself requires drilling, no secondary drilling is required when laying heat exchange, thus saving drilling costs. In addition, it occupies a small horizontal space and is not restricted by surrounding underground conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a schematic diagram of a tunnel geothermal antifreeze system based on energy piles according to the present invention.

[0020] Numbers in the figure: 1. Heat exchanger in the tunnel; 11. Heat exchange tube 1; 12. Circulating pump 1; 13. Valve 1; 2. Heat pump unit; 21. Evaporator; 22. Gas-liquid separator; 23. Compressor; 24. Oil separator; 25. Condenser; 26. Electronic expansion valve; 27. Filter; 28. Liquid receiver; 3. Tunnel energy pile; 4. Heat exchanger in tunnel pile foundation; 41. Circulating pump 2; 42. Valve 2; 43. Heat exchange tube 2; 5. Tunnel; 51. Surrounding rock; 52. Lining. DETAILED DESCRIPTION

[0021] Example, by Figure 1 A tunnel geothermal antifreeze system based on energy piles is provided, comprising a tunnel 5, a heat exchanger 1 in the tunnel, a heat pump unit 2 and a plurality of groups of tunnel energy piles 3, wherein the heat exchanger 1 in the tunnel, the heat pump unit 2 and the heat exchanger 4 in the tunnel pile foundation are connected through a pipeline circulation.

[0022] In this embodiment, multiple groups of tunnel energy piles 3 are connected to the heat exchanger 4 in the tunnel pile foundation, and the heat exchanger 4 in the tunnel pile foundation includes a circulation pump 2 41, a valve 2 42 and a heat exchange tube 2 43 installed inside each group of tunnel energy piles 3. The water inlet ends and the water outlet ends of the multiple heat exchange tubes 2 43 are respectively connected in parallel through pipes, the water outlet parallel pipe is connected to the input end of the circulation pump 2 41, the circulation pump 2 41 output end pipe is connected to the heat pump unit 2, the water inlet parallel pipe is connected to the output end of the valve 2 42, and the valve 2 42 input end pipe is connected to the heat pump unit 2;

[0023] Specifically, multiple tunnel energy piles 3 exchange heat with the surrounding soil, so that the water in the multiple heat exchange tubes 2 43 is heated up, and the hot water is transported to the evaporator 21 for heating through the circulation pump 2 41. The evaporator 21 absorbs the low-level heat source of the hot water to heat the internal refrigerant, and the water cooled by heat exchange flows back into the heat exchange tubes 2 43 of the multiple tunnel energy piles 3 to continue to exchange heat with the surrounding soil, forming a cycle.

[0024] Among them, the tunnel energy pile 3 is a reinforced concrete pile, and the heat exchange tube 2 43 is fixed in the steel cage of the tunnel energy pile 3 by binding. The steel cage and heat exchange tube 2 43 of the tunnel energy pile 3 are buried underground at a specified depth through drilling, and the soil is backfilled to the pile bottom elevation, and concrete is poured to form it.

[0025] Specifically, the heat exchange tube 2 43 is wrapped by the reinforced concrete pile body of the tunnel energy pile 3 to absorb heat and carry loads. The pile foundation of the tunnel energy pile 3 is used as a heat exchange well. The heat exchange tube 2 43 is buried in the pile foundation and connected to the heat pump system. The tunnel energy pile 3 exchanges heat with the surrounding soil. This can reduce the well drilling process of the ground source heat pump system and the grouting backfilling process of the heat exchange well.

[0026] In this embodiment, the tunnel 5 includes surrounding rock 51 and lining 52. The heat exchanger 1 in the tunnel is partially installed between the surrounding rock 51 and the lining 52 and connected to the heat pump unit 2 through a pipeline. The heat exchanger 1 in the tunnel includes multiple groups of heat exchange tubes 11, circulating pumps 12 and valves 13. The multiple groups of heat exchange tubes 11 are laid and installed between the surrounding rock 51 and the lining 52. The water inlet ends and water outlet ends of the multiple groups of heat exchange tubes 11 are respectively connected in parallel through pipelines, wherein the water outlet parallel pipeline is connected to the valve 13 input end, and the valve 13 output end is connected to the condenser 25 water liquid output end pipeline, and the water inlet parallel pipeline is connected to the valve 13 output end, and the valve 13 input end is connected to the condenser 25 water liquid output end pipeline.

[0027] Specifically, the circulating pump 12 extracts the water in the heat exchange tube 43 and circulates it to the condenser 25. The high-temperature refrigerant enters the condenser 25 and heats the water in the internal heat exchange tube 11. The heated water is transported to the heat exchange tube 43 in the tunnel 5 to heat the tunnel 5, thereby heating the tunnel 5 to melt snow.

[0028] In this embodiment, the heat pump unit 2 includes an evaporator 21, a gas-liquid separator 22, a compressor 23, an oil separator 24, a condenser 25, an electronic expansion valve 26, a filter 27 and a liquid receiver 28. The water-liquid output end pipeline of the evaporator 21 is connected to the input end of the valve 2 42, the water-liquid input end pipeline of the evaporator 21 is connected to the output end of the circulation pump 2 41, the medium output end pipeline of the evaporator 21 is connected to the input end of the gas-liquid separator 22, the gas-liquid separator 22 output end pipeline is connected to the input end of the compressor 23, the compressor 23 output end pipeline is connected to the input end of the oil separator 24, the oil separator 24 output end pipeline is connected to the medium input end of the condenser 25, the medium output end pipeline of the condenser 25 is connected to the input pipe of the liquid receiver 28, the output end pipeline of the liquid receiver 28 is connected to the input end of the filter 27, the output end pipeline of the filter 27 is connected to the input end of the electronic expansion valve 26, and the output end pipeline of the electronic expansion valve 26 is connected to the medium input end of the evaporator 21.

[0029] Specifically, hot water is transported to the evaporator 21 through the circulation pump 241 to be heated. The evaporator 21 absorbs the low-level heat source of the hot water to heat the internal refrigerant. The heated refrigerant flows from the evaporator 21 to the compressor 23. During the transportation process, the liquid droplets in the heated refrigerant are separated by the gas-liquid separator 22. The heated refrigerant enters the compressor 23. The compressor 23 compresses the refrigerant to increase its temperature and pressure, thereby converting the low-level heat energy into high-level heat energy. When the high-temperature refrigerant oil is transported to the condenser 25, it passes through the oil separator 24 to convert the refrigerant gas-liquid mixture into high-level heat energy. The lubricating oil in the condenser 25 is separated to prevent the lubricating oil from entering the condenser 25. The heat is released when entering the condenser 25. The high-temperature refrigerant enters the condenser 25 and heats the water in the internal heat exchange tube 11. The cooled refrigerant flows out of the condenser 25 and is stored in the liquid receiver 28. The liquid receiver 28 stores the output refrigerant. The refrigerant passes through the filter 27 to filter impurities in the refrigerant. The electronic expansion valve 26 adjusts the refrigerant flow entering the refrigeration device according to the preset program to achieve precise control, so that the refrigerant flows back into the evaporator 21 for heat exchange, and the cycle is repeated.

[0030] Evaporator 21: The liquid working medium absorbs heat from the air in the evaporator 21 and evaporates to form steam. The latent heat of vaporization is the recovered heat.

[0031] Gas-liquid separator 22: separates the liquid droplets in the airflow leaving the evaporator 21 and entering the compressor 23, prevents liquid hammer from occurring in the compressor 23, and plays a role in regulating the flow rate.

[0032] Compressor 23: compresses the gas into a high-temperature and high-pressure state to release the heat of the gas.

[0033] Oil separator 24 : Separates lubricating oil from the refrigerant gas-liquid mixture to prevent the lubricating oil from entering the condenser 25 and the evaporator 21 to affect the heat exchange efficiency, while ensuring the supply of lubricating oil in the compressor 23 .

[0034] Condenser 25: cools the high-temperature and high-pressure gas into liquid, releasing heat to the water that needs to be heated.

[0035] Electronic expansion valve 26: adjusts the refrigerant flow entering the refrigeration unit according to a preset program to achieve precise control.

[0036] Filter 27: Filters impurities in the refrigerant to ensure clean and efficient operation of the system.

[0037] Liquid receiver 28: stores liquid refrigerant and plays the role of buffering and stabilizing system pressure.

[0038] Tunnel 5 geothermal antifreeze system construction steps and working principles:

[0039] The construction steps of the geothermal antifreeze system of Tunnel 5 are as follows:

[0040] Step 1: Fix the heat exchange tube 2 43 in the steel cage of the tunnel energy pile 3 by binding, lower the steel cage and the heat exchange tube 2 43 to the specified depth, backfill the soil to the pile bottom elevation, pour concrete, and install and bury other tunnel energy piles 3 in the same way.

[0041] Step 2: Connect the inlet and outlet of the heat exchange pipe 2 43 of all buried tunnel energy piles 3 in parallel with the inlet and outlet water mains, which are respectively connected to the heat pump unit 2 through pipelines and controlled by the ground source heat pump control device.

[0042] Step 3: When the tunnel 5 is under construction, the heat exchange pipe 11 is buried between the surrounding rock 51 and the lining 52. The inlet and outlet of all heat exchange pipes 11 are connected in parallel with the inlet and outlet water main pipes, and the inlet and outlet water main pipes are connected to the heat pump unit 2 through pipelines.

[0043] Step 4: Complete the construction of Tunnel 5.

[0044] Working principle of Tunnel 5 geothermal antifreeze system:

[0045] The multiple tunnel energy piles 3 exchange heat with the surrounding soil, so that the water in the multiple heat exchange tubes 2 43 is heated up. The hot water is transported to the evaporator 21 for heating through the circulation pump 2 41. The evaporator 21 absorbs the low-level heat source of the hot water to heat the internal refrigerant. The heated refrigerant flows from the evaporator 21 to the compressor 23, and the water cooled by heat exchange flows back into the heat exchange tubes 2 43 of the multiple tunnel energy piles 3 to continue to exchange heat with the surrounding soil, forming a cycle.

[0046] During the transportation process, the liquid droplets in the heated refrigerant are separated through the gas-liquid separator 22, and the heated refrigerant enters the compressor 23. The compressor 23 compresses the refrigerant to increase its temperature and pressure, thereby converting low-level heat energy into high-level heat energy. When the high-temperature refrigerant oil is transported to the condenser 25, it passes through the oil separator 24 to separate the lubricating oil in the refrigerant gas-liquid mixture to prevent the lubricating oil from entering the condenser 25. When entering the condenser 25, the heat is released. The high-temperature refrigerant enters the condenser 25 and heats the water in the internal heat exchange tube 11. The circulating pump 12 extracts the water in the heat exchange tube 2 43 and circulates it to the condenser 25 for heating. The heated water is transported to the heat exchange tube 2 43 in the tunnel 5 to heat the tunnel 5, thereby heating the tunnel 5 to melt snow.

[0047] The cooled refrigerant flows out of the condenser 25 and is stored in the liquid receiver 28. The liquid receiver 28 stores the output refrigerant, and the refrigerant passes through the filter 27 to filter impurities in the refrigerant. The electronic expansion valve 26 adjusts the refrigerant flow entering the refrigeration device according to a preset program to achieve precise control, so that the refrigerant flows back into the evaporator 21 for heat exchange, and the cycle continues.

[0048] To sum up, the geothermal energy utilization technology based on energy piles is to turn the tunnel energy piles 3 buried underground into a part of the heat storage and heat exchange geothermal heat pump system, use the tunnel energy piles 3 as heat exchange wells, bury the heat exchange pipes in the pile foundation, and connect them to the heat pump system through pipelines. The tunnel energy piles 3 exchange heat with the surrounding soil, which can not only reduce the well drilling process of the geothermal heat pump system, but also reduce the grouting backfilling process of the heat exchange wells. At the same time, it can obtain geothermal energy from deep rock and soil layers through deep drilling, avoiding the huge plane layout area requirements of the geothermal heat pump. The application of energy pile technology can reduce the well drilling cost by about one-third of the cost of the entire heat exchange system, and at the same time shorten the construction period and save land space.

Claims

1. A tunnel geothermal antifreeze system based on energy piles, comprising a tunnel (5), a heat exchanger (1) in the tunnel, a heat pump unit (2) and a plurality of sets of tunnel energy piles (3), characterized in that: The plurality of groups of tunnel energy piles (3) are connected to a heat exchanger (4) in the tunnel pile foundation, and the heat exchanger (1) in the tunnel, the heat pump unit (2) and the heat exchanger (4) in the tunnel pile foundation are connected in a circulation manner via a pipeline; The heat exchanger (4) in the tunnel pile foundation comprises a second circulation pump (41), a second valve (42) and a second heat exchange pipe (43) installed inside each group of tunnel energy piles (3); the water inlet ends and the water outlet ends of the plurality of second heat exchange pipes (43) are respectively connected in parallel through pipes; the water outlet parallel pipe is connected to the input end of the second circulation pump (41); the pipe at the output end of the second circulation pump (41) is connected to the heat pump unit (2); the water inlet parallel pipe is connected to the output end of the second valve (42); the pipe at the input end of the second valve (42) is connected to the heat pump unit (2); The tunnel (5) comprises surrounding rock (51) and lining (52), and the heat exchanger (1) in the tunnel is partially installed between the surrounding rock (51) and the lining (52) and connected to the pipeline of the heat pump unit (2).

2. The tunnel geothermal antifreeze system based on energy piles according to claim 1 is characterized in that: The tunnel heat exchanger (1) comprises a plurality of heat exchange tubes (11), a circulation pump (12) and a valve (13). The plurality of heat exchange tubes (11) are laid and installed between the surrounding rock (51) and the lining (52). The water inlet and water outlet of the plurality of heat exchange tubes (11) are connected in parallel through pipelines, wherein the water outlet parallel pipeline is connected to the valve (13) input end, the valve (13) output end is connected to the condenser (25) water liquid output end pipeline, the water inlet parallel pipeline is connected to the valve (13) output end, the valve (13) input end is connected to the condenser (25) water liquid output end pipeline.

3. The tunnel geothermal antifreeze system based on energy piles according to claim 1 is characterized in that: The tunnel energy pile (3) is a reinforced concrete pile, and the second heat exchange tube (43) is fixed in the steel cage of the tunnel energy pile (3) by binding.

4. The tunnel geothermal antifreeze system based on energy piles according to claim 3 is characterized in that: The steel cage and the second circulating pump (41) of the tunnel energy pile (3) are buried underground at a specified depth by drilling holes, and then backfilled with soil to the pile bottom elevation and poured with concrete to form the pile.

5. The tunnel geothermal antifreeze system based on energy piles according to claim 1 is characterized in that: The heat pump unit (2) comprises an evaporator (21), a gas-liquid separator (22), a compressor (23), an oil separator (24), a condenser (25), an electronic expansion valve (26), a filter (27) and a liquid receiver (28); a pipeline at the water-liquid output end of the evaporator (21) is connected to an input end of a second valve (42); a pipeline at the water-liquid input end of the evaporator (21) is connected to an output end of a second circulation pump (41); a pipeline at the medium output end of the evaporator (21) is connected to an input end of the gas-liquid separator (22); a pipeline at the output end of the gas-liquid separator (22) is connected to an input end of the second circulation pump (41); The pipeline at the output end of the compressor (23) is connected to the input end of the oil separator (24), the pipeline at the output end of the oil separator (24) is connected to the medium input end of the condenser (25), the pipeline at the medium output end of the condenser (25) is connected to the input pipe of the liquid receiver (28), the pipeline at the output end of the liquid receiver (28) is connected to the input end of the filter (27), the pipeline at the output end of the filter (27) is connected to the input end of the electronic expansion valve (26), and the pipeline at the output end of the electronic expansion valve (26) is connected to the medium input end of the evaporator (21).

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