High-ground-temperature tunnel liquid nitrogen rock breaking-cooling integrated construction equipment and method
Through the integrated construction equipment of liquid nitrogen rock-breaking-cooling, the energy released by the liquid nitrogen phase transformation is used to crack and break rock. Through heat absorption and cooling, the safety hazards and construction quality problems of tunnel construction in high ground temperature environments are solved, and efficient and safe tunnel construction is achieved.
Patent Information
- Application Number
- CN202510613152.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-05-13
- Publication Date
- 2025-06-17
AI Technical Summary
In high ground temperature environments, tunnel construction technology faces problems such as health security for construction personnel, safety hazards of explosive rock breaking and construction quality, and the existing technology is difficult to adapt to this harsh environment.
The integrated construction equipment of liquid nitrogen rock-breaking and cooling is adopted to use the energy released by the liquid nitrogen phase transition to crack the rock mass and break the rock through nitrogen release. At the same time, the heat absorption effect of liquid nitrogen is used to reduce the temperature of the construction area.
It improves the safety and efficiency of rock-breaking operations in high-ground temperature tunnel environments, improves the working environment of construction workers, reduces the high-temperature failure rate of mechanical equipment, and achieves green and efficient tunnel construction.
Smart Images
Figure CN120159436A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of high geothermal tunnel construction, and particularly relates to an integrated construction equipment and method for rock breaking and temperature reduction with liquid nitrogen in high geothermal tunnels. Background Art
[0002] Tunnels are important channels for humans to cross mountains and seas, and are known as the "throat projects" in the field of transportation. With the gradual implementation of national strategies such as building a transportation power and a maritime power, large-scale engineering construction has gradually shifted to the western region and the deep part of the earth. Engineering construction faces extreme geological conditions and environments such as high geothermal temperature and deep major faults. For example, in a certain project in the southwest, nearly 50% of the tunnels along the project route pass through the alpine gorge area of the Hengduan Mountains in southeastern Tibet. There are multiple geothermal anomaly areas distributed along the project route, and the highest measured temperature of the exploration hole reaches 98°C. Such special construction environments with high rock temperature, high water temperature, and high air temperature have seriously affected aspects such as construction technology, construction machinery and equipment, and the physical and mental health of personnel. The existing tunnel construction technologies for normal temperature environments cannot overcome the new challenges brought by high geothermal environments, mainly including several difficulties: On the one hand, in a high-temperature environment, the physical state and stress level of construction workers will be significantly different from those in a normal temperature tunnel construction environment. Working for a long time in a high-temperature environment makes it difficult to guarantee the physical health of front-line workers, and psychological states such as high pressure and anxiety will have a negative effect on the construction process of human work operations, affecting construction quality; On the other hand, during the construction process of the tunnel face by the drill and blast method, it is a very important technological link to strip the surrounding rock of the tunnel face through explosive blasting. However, there are certain safety hazards in using explosives to break rocks in a high-temperature environment. Therefore, most of the tunnel construction methods in a conventional environment are not suitable for the harsh environment of high geothermal tunnels. Today, with the concept of green construction and sustainable development deeply rooted in people's hearts, it is urgent to innovate the tunnel construction technology in high geothermal environments and achieve green and efficient tunneling on the premise of ensuring the physical and mental health of personnel. Summary of the Invention
[0003] In view of one or more of the above deficiencies in the existing technologies, the present invention provides an integrated construction equipment and method for rock breaking and temperature reduction with liquid nitrogen in high geothermal tunnels, which uses the energy released by the rapid phase change of liquid nitrogen to efficiently crack rock masses and reduce the temperature of the construction area of personnel near the tunnel face, so as to achieve the green and safe construction of high geothermal tunnels.
[0004] To achieve the above object, the present invention adopts one or more of the following technical solutions: In the first aspect, an integrated construction equipment for rock breaking and temperature reduction with liquid nitrogen in high geothermal tunnels is provided, including an energy-releasing rock-breaking mechanism, a nitrogen supply mechanism, and a power supply system. The energy-releasing rock-breaking mechanism acts on the rock-breaking holes of the tunnel face. The nitrogen supply mechanism is connected to the energy-releasing rock-breaking mechanism by an insulated conveying pipe and conveys nitrogen. The power supply system is connected to the energy-releasing rock-breaking mechanism; The energy-releasing rock-breaking mechanism includes a nitrogen storage cavity, in which a high-energy electric spark generating device is arranged. By discharging, the liquid nitrogen undergoes a phase change and expands to absorb heat, reducing the ambient temperature. A number of pressure-controlled directional energy-releasing holes are provided on the side wall of the nitrogen storage cavity. The pressure-controlled directional energy-releasing holes are closed under normal conditions and open when the liquid nitrogen pressure in the nitrogen storage cavity reaches the pressure release threshold, connecting the nitrogen storage cavity with the surrounding rock, and high-pressure nitrogen is released for rock-breaking.
[0005] Furthermore, an expansion sealing plug is provided outside the nitrogen storage cavity. The expansion sealing plug is annularly wrapped around the outer wall of the nitrogen storage cavity for filling the gap between the outer wall of the nitrogen storage cavity and the rock-breaking hole. Two expansion sealing plugs are provided and have a spacing. A sealing section is formed between the two expansion sealing plugs, which can enable the nitrogen released from the pressure-controlled directional energy-releasing holes to better act on the surrounding rock and improve the rock-breaking effect.
[0006] Furthermore, a heating wire is also provided in the nitrogen storage cavity. The heating wire is connected to a control system, which can increase the internal temperature of the nitrogen storage cavity and pre-heat the liquid nitrogen before the high-energy electric spark is excited, thereby promoting the phase change process of the liquid nitrogen.
[0007] Furthermore, a diversion hole is provided on one side of the energy-releasing rock-breaking mechanism. The diversion hole is arranged on the high-strength cavity wall and is connected to the nitrogen storage cavity. When the liquid nitrogen is injected into the nitrogen storage cavity, the original air in the cavity can be smoothly discharged through the diversion hole. Preferably, a temperature control switch is provided on the diversion hole for controlling the opening and closing of the diversion hole according to the temperature in the nitrogen storage cavity.
[0008] Furthermore, the nitrogen supply mechanism includes a protective housing, in which a liquid nitrogen storage tank, a servo relay cavity and a nitrogen injection pipeline are provided. The servo relay cavity is connected to the outlet of the liquid nitrogen storage tank, and at least one nitrogen injection pipeline is connected to the outlet end of the servo relay cavity.
[0009] Furthermore, an electric control switch valve is provided on each nitrogen injection pipeline. The electric control switch valve is connected to the outlet end of the servo relay cavity for controlling the on-off of the nitrogen injection pipeline where it is located.
[0010] Furthermore, a high-pressure servo pump group is provided on the nitrogen injection pipeline. The high-pressure servo pump group is connected to the energy-releasing rock-breaking mechanism through a heat-insulating delivery pipe, directly controlling the liquid nitrogen pressure in the energy-releasing rock-breaking mechanism.
[0011] Furthermore, a low-temperature pump group is also provided on the nitrogen injection pipeline. The low-temperature pump group is arranged between the electric control switch valve and the high-pressure servo pump group and serves as the primary pressurization mechanism of the nitrogen injection pipeline to provide the basic pressure for the nitrogen injection pipeline.
[0012] Further, a pressure stabilizing chamber is arranged between the cryogenic pump group and the high-pressure servo pump group, which is used to absorb pressure fluctuations, buffer the influence of pressure fluctuations in the nitrogen injection pipeline on the output pressure, and improve the stability of the output pressure of the nitrogen injection pipeline.
[0013] Further, the power supply system includes a power source and a voltage stabilizing device. One end of the voltage stabilizing device is connected to the power source, and the other end is connected to the energy-releasing rock breaking device, which can adjust the output voltage of the power source to ensure that the excitation voltage of the energy-releasing rock breaking mechanism is more stable.
[0014] In a second aspect, a construction method for integrated nitrogen cryogenic rock breaking and cooling in high geothermal tunnels is provided. Based on the integrated nitrogen cryogenic rock breaking and cooling construction equipment for high geothermal tunnels described in any one of the above, the method includes the following steps: Use the nitrogen supply mechanism to fill nitrogen into the energy-releasing rock breaking mechanism and inject liquid nitrogen into the nitrogen storage cavity. Pressurize and heat the liquid nitrogen inside the energy-releasing rock breaking mechanism. When the internal pressure of the nitrogen storage cavity approaches the rock breaking excitation pressure, activate the high-energy electric spark generating device to generate a high-temperature electric arc in a short time. The liquid nitrogen absorbs energy and quickly undergoes phase change and expansion to generate high-pressure nitrogen. And when the internal pressure of the cavity reaches the excitation threshold of the pressure-controlled directional energy-releasing hole, the pressure-controlled directional energy-releasing hole opens, and the high-pressure nitrogen is released and acts on the surrounding rock to perform rock breaking operations. Before and after the rock breaking process, the nitrogen will absorb the heat of the surrounding environment and play a role in cooling the area near the tunnel face.
[0015] Further, the pressurizing and heating of the liquid nitrogen inside the energy-releasing rock breaking mechanism includes: Adjust the pressure parameter of the high-pressure servo pump group to increase the pressure of the liquid nitrogen inside the energy-releasing rock breaking mechanism until it reaches the pre-excitation pressure. Activate the heating wire to increase the internal temperature of the nitrogen storage cavity.
[0016] Adopting the above technical solutions, the beneficial effects of the present invention are as follows: The present invention transports liquid nitrogen to the energy-releasing rock-breaking mechanism through a nitrogen supply mechanism. The high-energy electric spark generated when the high-energy electric spark device is excited causes the liquid nitrogen in the nitrogen storage cavity to undergo a phase change, expand and absorb heat to generate high-pressure nitrogen, and the high-pressure nitrogen is released through the pressure-controlled directional energy-releasing holes for rock-breaking operations. On the one hand, the pressure generated by the phase change of liquid nitrogen is used to destroy the rock mass structure, effectively avoiding the influence of high-temperature environment on the performance of explosives, and greatly improving the safety of the rock-breaking operation process in the high-geothermal tunnel environment. On the other hand, when liquid nitrogen undergoes a phase change and absorbs heat, it can absorb a large amount of ambient temperature, forming a local non-high-temperature area near the working face area with intensive operations, which can significantly improve the working environment near the working face of the high-temperature tunnel, is conducive to protecting the physical and mental health of construction workers, and reducing the high-temperature failure rate of mechanical equipment. The equipment of the present invention is based on the design concept of modularization and assembly, which is convenient for long-term use and maintenance; it is integrally mounted on the engineering vehicle platform and can adapt to a variety of different engineering conditions. 3. In the present invention, the guiding hole is used to guide the rock-breaking construction at the rock-breaking hole. The rock-breaking hole can be designed in the form of a triangle, a pentagon, etc., so as to realize the development of various construction processes such as directional rock-breaking, pressure-relieving rock-breaking, and chain rock-breaking; and it is beneficial to further expand the construction technology of high-geothermal tunnels. Based on the present invention, more targeted construction plans and construction methods can be designed for different complex geological environments. BRIEF DESCRIPTION OF THE DRAWINGS
[0017] The accompanying drawings forming a part of this specification are used to provide a further understanding of the present invention. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation to the present invention.
[0018] Figure 1 Schematic diagram of the integrated liquid nitrogen rock-breaking and cooling construction equipment and its application in one or more embodiments of the present invention; Figure 2 Schematic diagram of the layout of the rock-breaking holes at the working face in one or more embodiments of the present invention; Figure 3 Schematic diagram of the energy-releasing rock-breaking mechanism in one or more embodiments of the present invention.
[0019] In the figure: 1, protective housing; 2, liquid nitrogen storage tank; 3, servo relay cavity; 4, electric control switch valve; 5, cryogenic pump group; 6, voltage stabilizing chamber; 7, high-pressure servo pump group; 8, heat-insulating conveying pipe; 9, engineering vehicle platform; 10, power supply; 11, voltage stabilizing device; 12, power supply wire; 13, tunnel working face; 14, rock-breaking hole; 15, guiding hole; 16, energy-releasing rock-breaking mechanism; 16-1, nitrogen storage cavity; 16-2, high-strength cavity wall; 16-3, expansion sealing plug; 16-4, pressure-controlled directional energy-releasing hole; 16-5, diversion hole; 16-6, high-energy electric spark generating device; 16-7, heating wire; 16-8, wire; 16-9, heat-insulating conveying pipe interface; 16-10, wire interface. Detailed implementation manners
[0020] It should be noted that the following detailed description is exemplary and is intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used in the present invention have the same meaning as commonly understood by those of ordinary skill in the technical field to which the present invention belongs.
[0021] It should be noted that the terms used herein are only for describing specific implementation manners and are not intended to limit the exemplary embodiments according to the present invention. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts belong to the scope of protection of the present invention.
[0022] Embodiment 1 In a typical implementation manner of the present application, a construction equipment for integrated rock breaking and temperature reduction of high geothermal tunnels with liquid nitrogen is provided. As Figures 1-3 shown, it includes an energy-releasing rock-breaking mechanism 16, a nitrogen supply mechanism, and a power supply system. The energy-releasing rock-breaking mechanism 16 acts on the rock-breaking hole 14 of the tunnel face. The nitrogen supply mechanism is connected to the energy-releasing rock-breaking mechanism 16 by a heat-insulating conveying pipe 8 and conveys nitrogen. The power supply system is connected to the energy-releasing rock-breaking mechanism 16 for power supply to provide excitation energy for liquid nitrogen rock breaking. The energy-releasing rock-breaking mechanism 16 includes a nitrogen storage cavity 16-1. An high-energy electric spark generating device 16-6 is arranged in the nitrogen storage cavity 16-1. By discharging, liquid nitrogen is vaporized and expanded to absorb heat, reducing the ambient temperature. A number of pressure-controlled directional energy-releasing holes 16-4 are provided on the side wall of the nitrogen storage cavity 16-1. The pressure-controlled directional energy-releasing holes are closed under normal conditions and open when the liquid nitrogen pressure in the nitrogen storage cavity reaches the pressure release threshold, connecting the nitrogen storage cavity with the surrounding rock, and high-pressure nitrogen is released for rock breaking.
[0023] Specifically, in combination with Figure 1 and Figure 2As shown in the figure, rock-breaking holes 14 and guiding holes 15 are arranged on the tunnel face 13. The guiding holes 15 are arranged around the rock-breaking holes 14 and are used to control the development direction of the main cracks during the rock-breaking process so as to achieve precise directional rock-breaking. In this embodiment, the energy-releasing rock-breaking mechanism 16 is fixed in the rock-breaking hole 14 for rock-breaking. The rear end of the energy-releasing rock-breaking mechanism 16 is respectively connected to a nitrogen supply mechanism and a power supply system. The nitrogen supply mechanism includes a liquid nitrogen storage tank 2, and a heat-insulating delivery pipe 8 delivers the liquid nitrogen in the liquid nitrogen storage tank to the energy-releasing rock-breaking mechanism 16. The power supply system includes a power source 10, which is connected to the energy-releasing rock-breaking mechanism 16 through a power supply wire 12 to supply power to structures such as a high-energy electric spark device and a heating wire inside the nitrogen storage cavity, providing the energy required for the excitation and energy release of the energy-releasing rock-breaking mechanism.
[0024] Specifically, as Figure 1 shown, the nitrogen supply mechanism includes a protective shell 1. Inside the protective shell 1, there are arranged a liquid nitrogen storage tank 2, a servo relay cavity 3, and at least one nitrogen injection pipeline. The liquid nitrogen storage tank 2 is arranged inside the protective shell 1 and is used to store liquid nitrogen. The servo relay cavity 3 is directly connected to the liquid nitrogen storage tank 2 and is used to temporarily store liquid nitrogen and directly supply nitrogen to the nitrogen injection pipeline. On the one hand, the volume of the relay cavity is smaller than that of the liquid nitrogen storage tank, which is better for controlling the pressure, thus ensuring the stable output of liquid nitrogen. On the other hand, it also has better safety. Servo valves are arranged at both the inlet and outlet of the cavity of the servo relay cavity 3 and can be uniformly controlled by the control system of the equipment. The outlet side of the servo relay cavity 3 can be connected to multiple nitrogen injection pipelines. Combining Figure 2 shown, in this embodiment, two rock-breaking holes 14 are opened on the tunnel face 13. Therefore, the outlet side of the servo relay cavity is connected to two parallel nitrogen injection pipelines, respectively supplying liquid nitrogen to the energy-releasing rock-breaking mechanisms in the two rock-breaking holes.
[0025] Among them, the protective shell is made of high-strength alloy material and serves as an explosion-proof protective shell, having characteristics such as anti-static and anti-impact. The whole protective shell 1 is placed on the engineering vehicle platform 9 and is designed with a modular combined structure. It can be conveniently combined with different vehicle chassis according to the tunnel construction conditions, so as to meet the operation requirements of different scenarios. Among them, the liquid nitrogen storage tank is transformed based on a standard liquid nitrogen storage device, and heat-insulating measures and anti-seismic measures are taken to meet the requirements of long-term transportation on a mobile platform. The engineering vehicle platform, as the main bearing platform of the rock-breaking and cooling integrated equipment in this embodiment, can be transformed based on a mature engineering vehicle chassis and has characteristics such as large load, large horsepower, large torque, and high mobility.
[0026] In this embodiment, combining Figure 1As shown in the figure, an electric control switch valve 4, a cryogenic pump set 5, a pressure stabilizing chamber 6, and a high-pressure servo pump set 7 are sequentially arranged on each nitrogen injection pipeline and are connected by a heat-insulating conveying pipe 8. The end of the heat-insulating conveying pipe 8 is communicated with the nitrogen storage cavity 16-1. Among them, the heat-insulating conveying pipe 8 is the main channel for liquid nitrogen to be transported from the liquid nitrogen storage tank 2 to the energy-releasing rock-breaking mechanism 16, and is composed of multiple layers of flexible composite materials, which can meet the high-pressure heat-insulating requirements during the long-term transportation of high-pressure liquid nitrogen.
[0027] Among them, the electric control switch valve 4 is arranged at the outlet end of the servo relay cavity 3 and is the branch switch of each nitrogen injection pipeline, used to control the on-off of the nitrogen injection pipeline where it is located. The electric control switch valve 4 is connected to the control system of the entire equipment and can be uniformly controlled by a computer. The cryogenic pump set 5 is arranged after the electric control switch valve 4 and serves as the primary pressurizing mechanism for each branch nitrogen injection pipeline, providing the basic pressure for the nitrogen injection pipeline and at the same time providing auxiliary pressure for the energy-releasing rock-breaking mechanism during the rock-breaking process. In this embodiment, the cryogenic pump set 5 adopts the mode of alternating energy replenishment of the cryogenic pump array, which can provide sufficient power for the liquid nitrogen transportation pipeline while maintaining the pipeline pressure, avoiding the premature phase change of liquid nitrogen in the pipeline, and can work for a long time in the environment from -250°C to room temperature, and has multiple working modes such as constant pressure, constant current, and pulse.
[0028] In this embodiment, as Figure 1 shown, the high-pressure servo pump set 7 is arranged at the end of the nitrogen injection pipeline and is connected to the control system, and can be directly controlled by a computer. The high-pressure servo pump set 7 serves as the secondary pressurizing mechanism for each branch nitrogen injection pipeline and adopts the mode of series operation of large-capacity pump sets to directly control the liquid nitrogen pressure in the energy-releasing rock-breaking mechanism 16, and can provide a maximum nitrogen injection pressure of 150 MPa. The high-pressure servo pump set is provided with a servo valve group, which can realize various pressure loading modes such as servo constant pressure, servo constant current, and servo pulse.
[0029] In this embodiment, combined with Figure 1 shown, a pressure stabilizing chamber 6 is arranged between the cryogenic pump set 5 and the high-pressure servo pump set 7. The pressure stabilizing chamber adopts the structure of a buffer tank in the prior art and is made of high-strength low-temperature-resistant materials, which can adapt to the low-temperature environment of liquid nitrogen transportation. By absorbing the pressure fluctuations generated during the liquid nitrogen transportation through the internal space, it can buffer the influence of the pressure fluctuations in the nitrogen injection pipeline on the output pressure and improve the stability of the output pressure of the nitrogen injection pipeline.
[0030] Specifically, as Figure 1As shown in the figure, the power supply 10, the voltage stabilizing device 11, and the power supply wire 12 together constitute a power supply system to provide excitation energy for the energy-releasing rock-breaking mechanism. Among them, the power supply 10 adopts a high-power power supply to meet the rock-breaking requirements. The voltage stabilizing device 11 is arranged at the outlet end of the power supply 10 and is connected to the energy-releasing rock-breaking structure through the wire 12, and can supply power to electrical devices such as a high-energy electric spark generating device and a heating wire. The voltage stabilizing device 11 can adjust the output voltage of the power supply 10 to make the voltage supplied to the energy-releasing rock-breaking mechanism more stable. The voltage stabilizing device can adopt products such as high-power power supply voltage stabilizers on the market.
[0031] Specifically, in combination with Figures 1-3 As shown in the figure, the energy-releasing rock-breaking mechanism 16 is integrally in a cylindrical structure and is arranged in a rock-breaking hole in the rock mass for rock-breaking operations. The main structure is a high-strength cavity wall 16-2 and an internal nitrogen storage cavity 16-1. The outer diameter of the high-strength cavity wall 16-2 matches the aperture of the corresponding rock-breaking hole. The nitrogen storage cavity 16-1, as the main part of the energy-releasing rock-breaking mechanism, collects the cryogenic liquid nitrogen transported from the nitrogen storage tank to the energy-releasing rock-breaking mechanism, laying a foundation for subsequent rock-breaking operations. The overall shape is cylindrical and needs to be placed in a drill hole in the rock mass for rock-breaking operations, and its diameter matches the aperture of the corresponding rock-breaking hole.
[0032] In this embodiment, an expansion sealing plug 16-3 is arranged outside the nitrogen storage cavity 16-1. The expansion sealing plug 16-3 adopts an electrically controlled excitation type flexible structure and is annularly wrapped around the outer wall of the high-strength cavity wall 16-2, and can fill the gap between the high-strength cavity wall and the rock-breaking hole. The expansion sealing plug 16-3 is connected to the control system, and the expansion sealing plug can be excited through the control system to completely fix the energy-releasing rock-breaking mechanism in the rock-breaking hole. In this embodiment, as Figure 3 shown in the figure, two expansion sealing plugs 16-3 are arranged. There is a certain interval between the two expansion sealing plugs 16-3, and a sealing section is formed between the two expansion sealing plugs 16-3, which can make the nitrogen released by the energy-releasing rock-breaking mechanism act better on the surrounding rock, achieving a better rock-breaking effect. Of course, in other embodiments, the number of expansion sealing plugs can be set to one or more, and this application does not limit this.
[0033] In this embodiment, as Figure 3As shown in the figure, several functional structures are provided inside the nitrogen storage cavity 16-1, including pressure-controlled directional energy release holes 16-4, high-energy electric spark generating devices 16-6, and heating wires 16-7. Among them, several pressure-controlled directional energy release holes 16-4 are arranged on the side wall of the high-strength cavity wall 16-2 and communicate with the inside of the nitrogen storage cavity 16-1. The pressure-controlled directional energy release hole 16-4 is a failure pressure relief mechanism dominated by pressure. Its principle is that when the pressure reaches the set threshold, the material fails and the hole opens, similar to a pressure-controlled valve. The valve automatically opens after the pressure reaches a certain value. Before liquid nitrogen is injected into the nitrogen storage cavity, the pressure-controlled directional energy release hole is in a closed state. When liquid nitrogen is injected and the pressure reaches the set pressure relief threshold, the pressure-controlled directional energy release hole will immediately fail, connecting the nitrogen storage cavity with the surrounding rock. The high-pressure nitrogen gas vaporized in the nitrogen storage cavity can act on the surrounding rocks through the pressure-controlled directional energy release holes to achieve rock breaking operations.
[0034] One or more high-energy electric spark generating devices can be provided. In this embodiment, as Figure 3 shown, two high-energy electric spark generating devices 16-6 are provided inside the nitrogen storage cavity 16-1, which are respectively arranged at the front end and the rear end of the nitrogen storage cavity 1. The two high-energy electric spark generating devices 16-6 are connected in parallel. A wire interface 16-10 is provided on the side wall of the high-strength cavity wall 16-2. One end of the wire interface 16-10 is connected to the power supply wire 12, and the other end is connected to the wire 16-8, which is used to supply power to the electrical devices inside the nitrogen storage cavity. The high-energy electric spark generating device 16-6 is connected to the wire interface 16-10 through the wire 16-8, and then connected to the power supply system. The output voltage of the power supply 10 is sent to the wire interface 16-10 through the voltage stabilizing device 11 and then sent to the high-energy electric spark generating device 16-6 through the wire 16-8 to provide excitation energy to activate the high-energy electric spark generating device, generate a high-temperature arc, quickly heat up and phase-change the liquid nitrogen in the nitrogen storage cavity, generate a relatively high pressure, and provide a sufficient power source for rock breaking operations.
[0035] In this embodiment, the heating wire 16-7 is arranged inside along the length direction of the nitrogen storage cavity, connected to the power supply system and the control system, and can be controlled by a computer. It pre-heats the liquid nitrogen in the cavity before the high-energy electric spark is excited to promote the phase change process of the liquid nitrogen.
[0036] In addition, as Figure 3As shown in the figure, heat-insulating conveying pipe interfaces 16-9 and diversion holes 16-5 are also provided at both ends of the energy-releasing rock-breaking mechanism 16. Among them, the heat-insulating conveying pipe interface 16-9 is arranged at the rear end and fixedly connected to the high-strength cavity wall 16-2. The inside of the heat-insulating conveying pipe interface 16-9 extends into the nitrogen storage cavity 16-1, and the outside is connected to the heat-insulating conveying pipe 8, facilitating the transportation of low-temperature liquid nitrogen in the liquid nitrogen storage tank into the nitrogen storage cavity. The diversion hole 16-5 is located on the front side of the energy-releasing rock-breaking mechanism and can be arranged at the end or on the side wall. When liquid nitrogen is injected into the nitrogen storage cavity, the original air in the cavity can be smoothly discharged through the diversion hole. In this embodiment, the diversion hole 16-5 is provided with a temperature control switch, which can control the opening and closing of the diversion hole according to the temperature in the nitrogen storage cavity. Specifically, the diversion hole is in the open state by default, and the temperature control switch controls the diversion hole to close when the temperature drops to the critical temperature of nitrogen.
[0037] Embodiment 2 In another typical embodiment of the present invention, a construction method for integrated liquid nitrogen rock breaking and temperature reduction in high geothermal tunnels is provided. Based on the integrated liquid nitrogen rock breaking and temperature reduction construction equipment in Embodiment 1, it includes: Using a nitrogen supply mechanism to fill nitrogen into the energy-releasing rock-breaking mechanism and injecting liquid nitrogen into the nitrogen storage cavity; Pressurizing and heating the liquid nitrogen inside the energy-releasing rock-breaking mechanism; When the internal pressure of the nitrogen storage cavity is close to the rock-breaking excitation pressure, activate the high-energy electric spark generating device to generate a high-temperature arc. The liquid nitrogen vaporizes and expands to generate high-pressure nitrogen, and the surrounding environmental heat is absorbed during the expansion process; and when the internal pressure of the cavity reaches the excitation threshold of the pressure-controlled directional energy-releasing hole, the pressure-controlled directional energy-releasing hole opens, and the high-pressure nitrogen is released and acts on the surrounding rock for rock-breaking operations.
[0038] Among them, the steps of pressurizing and heating the liquid nitrogen inside the energy-releasing rock-breaking mechanism are: Adjust the pressure parameters of the high-pressure servo pump group to increase the pressure of the liquid nitrogen inside the energy-releasing rock-breaking mechanism until the pre-excitation pressure is reached; Activate the heating wire to increase the internal temperature of the nitrogen storage cavity.
[0039] Specifically, the integrated construction method of liquid nitrogen rock breaking and temperature reduction provided in this embodiment will be further described below in combination with the process flow.
[0040] ① Construction preparation.
[0041] Before going to the construction area, ensure in advance that the liquid nitrogen storage tank is full of liquid nitrogen, the power supply is fully charged, arrange the rock-breaking holes and guiding holes on the tunnel face in advance, start the equipment power supply, and complete the self-inspection work of the equipment to ensure that the functions of each system are in a normal state.
[0042] ② Rock-breaking operation 1) Place the energy-releasing rock-breaking mechanism in the rock-breaking hole, and activate the expansion seal plug through the control system to completely fix the energy-releasing rock-breaking mechanism in the rock-breaking hole.
[0043] 2) Open the electric control switch valve through the control system, start the cryogenic pump group and the high-pressure servo pump group, and set the initial injection parameters. The liquid nitrogen in the liquid nitrogen storage tank enters the energy-releasing rock-breaking mechanism through the heat-insulating conveying pipe, passing through the servo relay cavity, the electric control switch valve, the cryogenic pump group, the pressure stabilizing chamber, and the high-pressure servo pump group in sequence.
[0044] 3) After the liquid nitrogen in the energy-releasing rock-breaking mechanism fills the nitrogen storage cavity, the liquid nitrogen contacts the diversion hole, triggering the temperature control switch therein, and then the diversion hole closes. At this time, the energy-releasing rock-breaking mechanism is only connected to the heat-insulating conveying pipe.
[0045] 4) Adjust the pressure parameters of the high-pressure servo pump group in the control system, gradually increase the liquid nitrogen pressure inside the energy-releasing rock-breaking mechanism until the pre-excitation pressure is reached, and then stop pressurizing; the high-pressure servo pump group maintains a one-way pressurizing state.
[0046] 5) Activate the heating wire in the control system to quickly increase the internal temperature of the nitrogen storage cavity, and at the same time monitor the pressure change inside the nitrogen storage cavity.
[0047] 6) When the internal pressure of the nitrogen storage cavity is close to the rock-breaking excitation pressure, activate the high-energy electric spark generating device to generate a high-temperature arc, so that the internal temperature of the nitrogen storage cavity rises rapidly and significantly. The liquid nitrogen undergoes a phase change to generate nitrogen gas. When the internal pressure of the cavity reaches the excitation threshold of the pressure-controlled directional energy-releasing hole, the pressure-controlled directional energy-releasing hole opens, and the high-pressure nitrogen gas is released through the pressure-controlled directional energy-releasing hole and acts on the rock mass around the drill hole to achieve rock-breaking operation. At the same time, when the liquid nitrogen undergoes a phase change and expands and absorbs heat, its own low-temperature state will absorb a large amount of ambient temperature, thereby forming a local non-high-temperature area near the heading face area, which can effectively improve the working environment near the high-temperature tunnel heading face, is conducive to protecting the physical and mental health of construction workers, and avoids mechanical equipment failures due to high temperature.
[0048] ③ Equipment shutdown and maintenance After the rock-breaking is completed, close all the valves on the pipeline, recover the energy-releasing rock-breaking mechanism during the mucking operation, and then the entire equipment leaves the operation site with the engineering vehicle platform. Replace the worn components and prepare for the next rock-breaking operation.
[0049] In this embodiment, for the construction project of complex high geothermal tunnels such as high rock temperature, high water temperature, and high air temperature, liquid nitrogen is used as the main energy source for rock breaking, and the rock mass structure is destroyed by the pressure generated by the phase change of liquid nitrogen. Compared with traditional explosive blasting, it avoids the influence of high temperature environment on the performance of explosives, essentially eliminates the risk source, and greatly improves the safety during the rock breaking operation. Moreover, when liquid nitrogen expands and absorbs heat during phase change, its own low temperature state will absorb a large amount of ambient temperature, forming a local non-high temperature area near the face area with intensive operations, which can significantly improve the operation environment near the face of the high temperature tunnel and has important practical significance for protecting the physical and mental health of construction workers and reducing the influence of high temperature on mechanical equipment.
[0050] The technological process of this embodiment is simple, the operation is convenient, it is user-friendly, has a low usage threshold, and is convenient for construction workers to operate.
[0051] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Those of ordinary skill in the art should understand that the present invention can have various changes and modifications. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.
Claims
1. A high geothermal tunnel liquid nitrogen rock breaking and cooling integrated construction equipment, characterized in that: It includes an energy-releasing rock-breaking mechanism, a nitrogen supply mechanism and a power supply system. The energy-releasing rock-breaking mechanism acts in the rock-breaking hole of the tunnel face. The nitrogen supply mechanism is connected to the energy-releasing rock-breaking mechanism by a heat-insulating delivery pipe and delivers nitrogen. The power supply system is connected to the energy-releasing rock-breaking mechanism. The energy-releasing and rock-breaking mechanism comprises a nitrogen storage cavity, in which a high-energy electric spark generating device is arranged, and liquid nitrogen is vaporized, expanded and absorbs heat by discharge to reduce the ambient temperature; a plurality of pressure-controlled directional energy-releasing holes are arranged on the side wall of the nitrogen storage cavity, and the pressure-controlled directional energy-releasing holes are normally closed. When the liquid nitrogen pressure in the nitrogen storage cavity reaches a pressure-releasing threshold, the pressure-controlled directional energy-releasing holes are opened, and the nitrogen storage cavity is connected with the external surrounding rock, and high-pressure nitrogen is released to break the rock.
2. The high geothermal tunnel liquid nitrogen rock breaking and cooling integrated construction equipment according to claim 1, characterized in that: An expansion sealing plug is provided outside the nitrogen storage cavity. The expansion sealing plug is annularly wrapped around the outer wall of the nitrogen storage cavity and is used to fill the gap between the outer wall of the nitrogen storage cavity and the rock-breaking hole. Two expansion sealing plugs are provided and spaced apart, and a sealing section is formed between the two expansion sealing plugs.
3. The high geothermal tunnel liquid nitrogen rock breaking and cooling integrated construction equipment according to claim 1, characterized in that: A heating wire is also provided in the nitrogen storage cavity, and the heating wire is connected to a control system.
4. The high geothermal tunnel liquid nitrogen rock breaking and cooling integrated construction equipment according to claim 1, characterized in that: The nitrogen supply mechanism comprises a protective shell, in which a liquid nitrogen storage tank, a servo relay chamber and a nitrogen injection pipeline are arranged. The servo relay chamber is connected to the outlet of the liquid nitrogen storage tank, and the outlet end of the servo relay chamber is connected to at least one nitrogen injection pipeline.
5. The high geothermal tunnel liquid nitrogen rock breaking and cooling integrated construction equipment as claimed in claim 4, characterized in that: Each of the nitrogen injection pipelines is provided with an electrically controlled switch valve, which is connected to the outlet end of the servo relay cavity and is used to control the on-off of the nitrogen injection pipeline.
6. The high geothermal tunnel liquid nitrogen rock breaking and cooling integrated construction equipment as claimed in claim 4, characterized in that: The nitrogen injection pipeline is provided with a high-pressure servo pump group, which is connected to the energy-releasing rock-breaking mechanism through a heat-insulating delivery pipe to directly control the liquid nitrogen pressure in the energy-releasing rock-breaking mechanism.
7. The high geothermal tunnel liquid nitrogen rock breaking and cooling integrated construction equipment as claimed in claim 6, characterized in that: A cryogenic pump group is also provided on the nitrogen injection pipeline. The cryogenic pump group is arranged between the electronically controlled switch valve and the high-pressure servo pump group, and serves as a primary pressurizing mechanism of the nitrogen injection pipeline to provide basic pressure for the nitrogen injection pipeline. A pressure stabilizing chamber is arranged between the cryogenic pump group and the high-pressure servo pump group.
8. The high geothermal tunnel liquid nitrogen rock breaking and cooling integrated construction equipment according to claim 1, characterized in that: The power supply system comprises a power supply and a voltage stabilizing device, one end of the voltage stabilizing device is connected to the power supply, and the other end is connected to a high-energy electric spark generating device of the energy-releasing rock-breaking mechanism.
9. A high geothermal tunnel liquid nitrogen rock breaking and cooling integrated construction method, based on a high geothermal tunnel liquid nitrogen rock breaking and cooling integrated construction equipment as claimed in any one of claims 1 to 8, characterized in that: The steps include: The nitrogen supply mechanism is used to charge the energy-releasing rock-breaking mechanism with nitrogen, and liquid nitrogen is injected into the nitrogen storage cavity; Pressurize and heat the liquid nitrogen inside the energy-releasing rock-breaking mechanism; When the pressure inside the nitrogen storage cavity is close to the rock-breaking excitation pressure, the high-energy electric spark generating device is activated to generate a high-temperature arc, and the liquid nitrogen vaporizes and expands to generate high-pressure nitrogen. The expansion process absorbs heat from the surrounding environment. When the pressure inside the cavity reaches the excitation threshold of the pressure-controlled directional energy release hole, the pressure-controlled directional energy release hole opens, and the high-pressure nitrogen is released to act on the surrounding rock to carry out rock breaking operations.
10. A high geothermal tunnel liquid nitrogen rock breaking and cooling integrated construction method as claimed in claim 9, characterized in that: The pressurizing and heating of the liquid nitrogen inside the energy-releasing rock-breaking mechanism comprises: Adjust the pressure parameters of the high-pressure servo pump group to increase the liquid nitrogen pressure inside the energy-releasing rock-breaking mechanism until the pre-excitation pressure is reached; Activate the heating wire to increase the temperature inside the nitrogen storage chamber.