Liquefied air energy storage rock breaking device for tunnel excavation

Abstract

The utility model provides a liquefied air energy storage rock breaking device for tunnel excavation, and relates to the technical field of tunnel engineering construction devices, the liquefied air energy storage rock breaking device for tunnel excavation comprises a blasting pipe, an impact pipe and a tensioning sleeve, the blasting pipe is of a hollow cylindrical structure, and a blasting cavity filled with liquefied air is formed in the blasting pipe. A heating component capable of conducting gradient heating is arranged at the top of the blasting cavity, and a connecting shaft arranged at one end of the blasting pipe is further included in a preferable scheme. Through cooperation of the structures, the rock breaking device has the following beneficial effects that firstly, the outer ring of the tensioning sleeve is tensioned and fixed to the inner wall of the rock breaking hole, and the tensioning sleeve can prevent the problem of pipe flying caused by the fact that the rock breaking device flies out of the rock breaking hole due to the counter-acting force in the rock breaking process of the impact rod; and secondly, resistors in three different areas are arranged on a heating part, a resistance gradient with the high front part and the low rear part is formed, sectional type gasification is achieved, uncontrollable pressure impact caused by instantaneous energy concentration is avoided, and therefore the blasting pipe is prevented from being rushed out.

Description

TECHNICAL FIELD

[0001] The utility model relates to a tunnel engineering construction device technical field, especially a kind of liquefied air energy storage rock breaking device for tunnel excavation. BACKGROUND

[0002] In tunnel construction technology, drill and blast method, shield method and full-face tunnel boring machine method are relatively mature main excavation methods. In particular, in drill and blast method, liquefied air blasting is widely used as an environmentally friendly and effective rock breaking technology. The method injects liquefied air (mainly composed of liquid oxygen and liquid nitrogen) into a specially designed blasting pipe, and places it in a pre-drilled rock hole. Then, the liquefied air is heated to rapidly gasify, producing high-pressure gas to break the rock.

[0003] However, in actual application, especially in the process of shallow hole blasting, due to the uniform distribution of heating power in the axial direction of the blasting pipe, the liquefied air rapidly gasifies simultaneously. Especially in the case of uniform resistance of a single heating rod, this uniform heating will cause the liquefied air to gasify preferentially from the middle or rear end of the blasting pipe, causing a sudden rise in gas pressure. The reaction force generated by this high-pressure gas is concentrated in an instant explosion, which can easily cause the blasting pipe to be impacted and fly out of the hole, i.e. the "blasting pipe flying pipe" phenomenon. This situation not only may cause blasting failure, but also may cause blasting pipe damage or even personnel injury, seriously affecting the safety of construction. Therefore, in order to improve the safety of shallow hole blasting construction in tunnels, a blasting rock breaking device that can avoid the flying pipe problem is needed. SUMMARY

[0004] To solve the above-mentioned problems of the prior art, the technical problem to be solved by the utility model is to provide a liquefied air energy storage rock breaking device for tunnel excavation, which can suppress the peak value of reaction force and guide the directional expansion of gas, thereby avoiding the flying pipe problem.

[0005] To solve the above-mentioned problems, the utility model adopts the following technical scheme: the utility model provides a liquefied air energy storage rock breaking device for tunnel excavation, comprising a blasting pipe, an impact pipe and a tension sleeve. The blasting pipe is a hollow cylindrical structure, and has a blasting cavity filled with liquefied air inside. The blasting cavity is characterized by a gradient-heatable heating component at the top.

[0006] In a preferred embodiment, a connecting shaft is provided at one end of the blasting pipe. The inner wall of the blasting cavity has a blasting hole at the end, and the blasting hole has a bursting disc. The bursting disc blocks the blasting hole.

[0007] The impact tube is arranged at the end of the blasting tube, and the impact tube is axially provided with a piston hole, a piston sliding block is arranged in the piston hole, the piston sliding block is slidable in the piston hole, a driving slope is arranged below the piston sliding block, and the impact tube is radially provided with a plurality of transverse impact holes;

[0008] A transverse impact rod is arranged in the transverse impact hole, and an end of the transverse impact rod close to the piston hole is a driving end, the driving end of the transverse impact rod is provided with a driven slope matched with the driving slope, and the plurality of transverse impact rods are radially distributed at equal angles.

[0009] In the preferred scheme, the piston hole is opposite to the blasting hole, the piston hole is coaxial with the blasting hole, and the diameters of the piston hole and the blasting hole are equal, the piston hole and the blasting hole are separated by a bursting disc;

[0010] A lower impact hole is arranged at the lower end of the impact tube, and a lower impact rod is arranged at the lower end of the piston sliding block and located in the lower impact hole;

[0011] The driving slope is a conical frustum, and the driven slope is matched with the driving slope.

[0012] In the preferred scheme, a plurality of pressure relief holes are further arranged on the impact tube, the pressure relief holes penetrate the side wall of the impact tube and are communicated with the piston hole, and the pressure relief holes are located above the transverse impact holes.

[0013] In the preferred scheme, the expansion sleeve is sleeved on the connecting shaft, the expansion sleeve is a liquid expansion sleeve, a ring-shaped liquid expansion cavity is arranged in the liquid expansion sleeve, one end of the liquid expansion sleeve is provided with a liquid inlet, and a liquid delivery pipe is connected to the liquid inlet;

[0014] A one-way valve is arranged on the liquid inlet, a liquid outlet is further arranged on the liquid expansion sleeve, an overflow valve is arranged on the liquid outlet, a plurality of embedded protruding portions are arranged on the outside of the liquid expansion sleeve, and the embedded protruding portions are used for being embedded in the inner wall of the rock breaking hole under the action of liquid expansion.

[0015] In the preferred scheme, a fastening shaft is further arranged on the connecting shaft, a fastening thread is arranged on the outer wall of the fastening shaft, a fixing threaded sleeve is arranged on the fastening shaft, the fixing threaded sleeve is arranged on the fastening shaft, and the lower end of the fixing threaded sleeve presses the expansion sleeve.

[0016] The connecting shaft is a circular frustum shaft with a thin upper end and a thick lower end, and the inner wall of the expansion sleeve is a conical frustum surface matched with the outer surface of the circular frustum shaft.

[0017] The connecting shaft is axially provided with a wire hole, a connecting wire is arranged in the wire hole, the connecting wire is connected with the heating component, and the connecting wire extends to the outside of the blasting tube.

[0018] In the preferred scheme, the heating component is a gradually changing resistance spiral heating wire, the gradually changing resistance spiral heating wire is spirally wound along the axial direction of the blasting tube, the wire diameter of the gradually changing resistance spiral heating wire continuously increases from top to bottom along the axial direction, the resistance value of the gradually changing resistance spiral heating wire continuously decreases from top to bottom along the axial direction, and a three-section gradient distribution is formed.

[0019] In a preferred embodiment, the three-section gradient distribution is divided into an upper high-resistance section, a middle medium-resistance section and a lower low-resistance section.

[0020] In a preferred embodiment, the rupture disc is made of nickel-based superalloy.

[0021] In a preferred embodiment, the rupture disc has a diameter of 80 mm, a thickness of 3 mm and a safety threshold of 15 MPa.

[0022] The utility model provides a kind of liquefied air energy storage rock breaking device for tunnel excavation, by the cooperation between above structure, with following beneficial effects:

[0023] First, by the outer ring of tight sleeve is fixed in the inner wall of rock breaking hole, tight sleeve can prevent the reaction force in the process of impact rod rock breaking from flying out of rock breaking device and cause the problem of flying pipe, to improve the safety and rock breaking efficiency of rock breaking device;

[0024] Second, by setting three different regions of resistance to heating component, form the resistance gradient of high in front and low in back, realize sectional gasification, front resistance is big, temperature is high, preferential gasification liquefied air, gasification starting point is close to hole bottom, back resistance gradually reduces, temperature is lower, gasification is slower, delay hole mouth end gasification, and utilize directional expansion to guide high-pressure gas to hole bottom direction expansion by Bernoulli effect, to gradually release pressure in this way, form energy progressive release, avoid uncontrollable pressure impact caused by instantaneous energy concentration, reduce the peak value of instantaneous reaction force, to prevent blast pipe from being flushed out. BRIEF DESCRIPTION OF DRAWINGS

[0025] The utility model will be further described below in connection with drawings and examples:

[0026] Figure 1 It is the overall structure schematic diagram of working in the embodiment of the utility model.

[0027] Figure 2 It is the internal structure diagram in the embodiment of the utility model.

[0028] Figure 3 It is Figure 2 The enlarged view of place A in middle.

[0029] Figure 4 It is the structure schematic diagram of blast pipe and impact pipe in the embodiment of the utility model.

[0030] In the drawing: blast pipe 1, blast cavity 11, rupture disc 12, connecting shaft 13, impact pipe 2, piston hole 21, transverse impact rod 22, pressure relief hole 23, lower impact rod 24, piston sliding block 3, driving slope 31, heating component 4, connecting wire 5, tight sleeve 6, infusion tube 61, fixed threaded sleeve 7, rock breaking hole 8. DETAILED DESCRIPTION

[0031] For better understanding of the purpose, structure and function of the utility model, the embodiments in the application and the features in the embodiments can be combined with each other without conflict. The utility model will be described in detail below with reference to the drawings and in combination with embodiments.

[0032] EMBODIMENT

[0033] As Figures 1 to 4 The utility model relates to a liquefied air energy storage rock breaking device for tunnel excavation, comprising a blasting pipe 1, an impact pipe 2 and a tension sleeve 6.

[0034] The top of the blasting pipe 1 is provided with a connecting shaft 13; the blasting pipe 1 is a hollow cylindrical structure, and is internally provided with a blasting cavity 11; the top of the blasting cavity 11 is provided with a heating component 4; the blasting cavity 11 is filled with liquefied air; the heating component 4 is fixed in the blasting cavity 11; a connecting wire 5 is connected to the heating component 4 and extends to the outside of the blasting pipe 1; the connecting wire 5 is used to control the heating of the liquefied air by the heating component 4, thereby controlling the blasting process of the blasting pipe 1.

[0035] The heating component 4 is a heating rod or a gradually changing resistance spiral heating wire.

[0036] In an implementable mode, the heating component 4 is a heating rod; a single heating rod causes an axial temperature gradient of 200-300 DEG C / m, and the difference in the gasification rate of liquid oxygen is > 40%.

[0037] In another implementable mode, the heating component 4 is a gradually changing resistance spiral heating wire; the gradually changing resistance spiral heating wire changes the resistance by using the method of continuously changing the wire diameter, realizes temperature zoning through the resistance gradient, and is distributed in three sections for independent temperature control when heating; the upper part of the blasting cavity is rapidly heated to start gasification, the middle part maintains stable gasification, and the lower part prevents premature gasification from causing pressure loss; the regional control can optimize the gasification process, ensure the concentrated release of high-pressure gas when needed, and not produce pressure unevenly in the entire blasting cavity, which can effectively utilize energy and accelerate the rock breaking speed.

[0038] It should be noted that the gradually changing resistance spiral heating wire is spirally wound along the axial direction of the blasting pipe 1, and the resistance value decreases from the front end to the rear end in sequence, forming a three-section gradient distribution.

[0039] The upper part of the gradually changing resistance spiral heating wire has a length of 35 mm, a wire diameter of Φ1.2 mm, and a pitch of the coil of 8 mm, and has the highest resistance value, preferentially heating the liquefied air at the deep hole end.

[0040] The middle length of the gradually changing resistance spiral heating wire is 45 mm, the wire diameter is Φ1.6 mm, the pitch of the coil is 12 mm, the resistance value is moderate, the gasification rate is controlled, and the stable gasification rate is maintained, and the pressure is continuously increased to 15 MPa;

[0041] The lower length of the gradually changing resistance spiral heating wire is 20 mm, the wire diameter is Φ2.0 mm, the pitch of the coil is 15 mm, the resistance value is the lowest, the orifice end gasification is delayed, and the pressure relief is prevented.

[0042] The performance comparison of the heating rod and the gradually changing resistance spiral heating wire is shown in Table 1 below:

[0043] Table 1

[0044]

[0045] The connecting wire 5 is connected to the microcontroller, and the temperature layered control is realized through the PID algorithm: the upper part of the heating component 4 is maintained at 200℃±3℃, the middle part of the heating component 4 is maintained at 150℃±2℃, and the lower part of the heating component 4 is controlled at 50℃±5℃.

[0046] The bottom of the explosion cavity 11 is provided with an explosion hole, and the explosion hole is provided with a bursting disc 12. The bursting disc 12 blocks the explosion hole, and the explosion hole is used to seal the liquefied air in the explosion cavity 11. After the liquefied air is detonated, the high-pressure gas enters the impact tube 2 by breaking the explosion hole.

[0047] It should be noted that the bursting disc 12 is made of corrosion-resistant alloy, including one of austenitic stainless steel or nickel-based high-temperature alloy, and the threshold value of the bursting disc 12 is calculated by the ratio of thickness to diameter and the bursting pressure formula:

[0048]

[0049] Wherein, is the tensile strength of the material, t is the thickness, D is the diameter, and K is a coefficient with a value of 0.35, which depends on the edge fixing method.

[0050] The bearing threshold of the bursting disc 12 in this embodiment is shown in Table 2 below:

[0051] Table 2

[0052]

[0053] The impact tube 2 is threadedly connected to the end position of the bursting tube 1. The impact tube 2 is axially provided with a piston hole 21, and the impact tube 2 is radially provided with a plurality of transverse impact holes. The piston hole 21 is opposite to the explosion hole, the piston hole 21 is coaxial with the explosion hole, and the diameters of the two are equal. The piston hole 21 and the explosion hole are separated by the bursting disc 12.

[0054] ​A piston sliding block 3 is arranged in the piston hole 21 and can slide in the piston hole 21, and a driving slope 31 is arranged below the piston sliding block 3;

[0055] In the embodiment, the driving slope 31 is a conical frustum, a transverse impact rod 22 is arranged in the transverse impact hole, the end of the transverse impact rod 22 close to the piston hole 21 is a driving end, a driven slope is arranged on the driving end of the transverse impact rod 22, a plurality of transverse impact rods 22 are distributed at equal angles in a radial manner, and the driven slope is attached to the driving slope 31.

[0056] In the embodiment, the outer diameters of the blasting pipe 1 and the impact pipe 2 are equal, and the outer diameters of the blasting pipe 1 and the impact pipe 2 are slightly smaller than the diameter of the rock breaking hole 8, so that the blasting pipe 1 and the impact pipe 2 can be placed in the rock breaking hole 8, and the outer wall of the expansion sleeve 6 is attached to the inner wall of the pre-drilled rock breaking hole 8, so as to fix the rock breaking device.

[0057] When the liquefied air energy storage rock breaking device works, a rock breaking hole 8 is pre-drilled in the rock to be broken, the whole device is placed in the rock breaking hole 8, high-pressure oil is injected into the expansion sleeve 6 to make the expansion sleeve 6 expand and fix the rock breaking device, then the liquefied air in the blasting pipe 1 is heated by the heating component 4, the liquefied air in the blasting cavity 11 is rapidly gasified to produce high-pressure air, and the energy is controlled in three stages to realize step-by-step gasification. The resistance of the upper part of the heating component 4 in the initiation stage is large, the temperature is high, the liquefied air is preferentially gasified, the middle part of the heating component 4 in the continuous stage maintains stable gasification, the lower part of the heating component 4 in the finishing stage is zero power, the gasification starting point is close to the hole bottom, the rear resistance gradually decreases, the temperature is relatively low, and the gasification is relatively slow. The gasification of the hole opening end is delayed, and the Bernoulli effect is used to guide the high-pressure gas to expand towards the hole bottom, so as to gradually release the pressure, form energy progressive release, avoid uncontrolled pressure impact caused by instantaneous energy concentration, reduce the peak value of instantaneous reaction force, and the high-pressure air can break the bursting disc 12 to push the piston sliding block in the piston hole 21 of the impact pipe 2 to move downward, so that the piston sliding block drives multiple impact rods to apply impact load to the inner wall of the rock breaking hole 8 at the same time, promotes the rock breaking hole 8 to break, and achieves the effect of rapidly breaking the rock. And the expansion sleeve 6 can prevent the reaction force in the rock breaking process of the impact rod from causing the rock breaking device to fly out of the rock breaking hole 8 and cause the problem of flying pipe, thereby improving the safety and rock breaking efficiency of the rock breaking device.

[0058] In the preferred embodiment, the expansion sleeve 6 is a liquid expansion sleeve, a ring-shaped liquid expansion cavity is arranged in the liquid expansion sleeve, a liquid inlet is arranged at the top of the liquid expansion sleeve, and a liquid delivery pipe 61 is connected to the liquid inlet.

[0059] A one-way valve is arranged on the liquid inlet. The liquid delivery pipe 61 is connected to a high-pressure oil injection device, and is used to input high-pressure oil into the liquid expansion sleeve after the whole rock breaking device is placed in the rock breaking hole 8, so that the outer wall of the expansion sleeve 6 expands against the inner wall of the rock breaking hole 8.

[0060] In the preferred embodiment, the liquid expansion sleeve is further provided with a liquid discharge port, and the liquid discharge port is provided with an overflow valve. The liquid expansion sleeve is externally provided with a plurality of embedded protrusions, which are used to embed into the inner wall of the rock breaking hole 8 under the action of liquid expansion.

[0061] In the preferred embodiment, the impact tube is further provided with a plurality of pressure relief holes 23, which penetrate through the sidewall of the impact tube and communicate with the piston hole 21, and the pressure relief holes 23 are located above the transverse impact hole. After the piston sliding block 3 moves downward by a distance, the end of the pressure relief hole 23 is opened, so that the high-pressure air in the piston hole 21 can be discharged, preventing the impact tube from being damaged by high-pressure air.

[0062] In the preferred embodiment, the connecting shaft 13 is further provided with a fastening shaft, the outer wall of the fastening shaft is provided with a fastening thread, the fastening shaft is provided with a fixed threaded sleeve 7, the fixed threaded sleeve 7 is threadedly connected to the fastening shaft, the lower end of the fixed threaded sleeve 7 presses the expansion sleeve 6, and the fixed threaded sleeve 7 is used to firmly connect the expansion sleeve 6 to the connecting shaft 13.

[0063] In the preferred embodiment, the connecting shaft 13 is a circular truncated cone shaft with a thin upper end and a thick lower end, and the inner wall of the expansion sleeve 6 is a conical truncated surface matched with the outer surface of the circular truncated cone shaft. The circular truncated cone structure of the connecting shaft 13 can further exert an outward tension on the expansion sleeve 6 during the blasting process, ensuring that the entire rock breaking device will not be ejected from the rock breaking hole 8.

[0064] In the preferred embodiment, the lower end of the impact tube is provided with a lower impact hole, the lower end of the piston sliding block 3 is provided with a lower impact rod 24, the lower impact rod 24 is located in the lower impact hole, and the lower impact rod 24 can impact the bottom of the rock breaking hole 8 during the downward movement of the piston sliding block 3, thereby further improving the rock breaking effect.

[0065] In the preferred embodiment, the connecting shaft 13 is axially provided with a wire hole, and the wire hole is provided with a connecting wire 5 connected to the heating component 4.

[0066] In order for those skilled in the art to better understand the technical scheme of the present application, the above-mentioned embodiments are only preferred technical schemes of the present application, and should not be regarded as limiting the present application. The protection scope of the present application should be based on the technical scheme recited in the claims, including equivalent replacement schemes of the technical features recited in the claims. That is, equivalent replacement improvements within this scope are also within the protection scope of the present application.

[0067] It also needs to be explained that the terms "first", "second" and the like in the description and claims of the utility model and the above-mentioned drawings are used to distinguish similar objects, and do not have to be used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged under appropriate circumstances, so that the embodiments of the utility model described herein.

Claims

1. A liquefied air energy storage rock-breaking device for tunnel excavation, comprising a blasting pipe (1), an impact pipe (2), and a tensioning sleeve (6), wherein the blasting pipe (1) is a hollow cylindrical structure and has an internal blasting cavity (11) filled with liquefied air, characterized in that, The top of the blasting chamber (11) is equipped with a heating element (4) that can be heated in a gradient.

2. The liquefied air energy storage rock-breaking device for tunnel excavation according to claim 1, characterized in that, It also includes a connecting shaft (13) at one end of the blasting tube (1), and a blasting hole is provided at the end of the inner wall of the blasting chamber (11). A blasting disc (12) is provided in the blasting hole, and the blasting disc (12) seals the blasting hole. The impact tube (2) is located at the end of the blasting tube (1). The impact tube (2) is provided with a piston hole (21) in the axial direction. A piston slider (3) is provided in the piston hole (21). The piston slider (3) can slide in the piston hole (21). A driving inclined surface (31) is provided below the piston slider (3). The impact tube (2) is provided with multiple transverse impact holes in the radial direction. The transverse impact hole is provided with a transverse impact rod (22). The end of the transverse impact rod (22) near the piston hole (21) is the driving end. The driving end of the transverse impact rod (22) is provided with a driven inclined surface that is compatible with the driving inclined surface (31). Multiple transverse impact rods (22) are radially distributed at equal angles.

3. The liquefied air energy storage rock-breaking device for tunnel excavation according to claim 2, characterized in that, The piston hole (21) is directly opposite the blast hole. The piston hole (21) and the blast hole are coaxial and have the same diameter. The piston hole (21) and the blast hole are separated by a rupture disc (12). The lower end of the impact tube (2) is provided with a lower impact hole, and the lower end of the piston slider (3) is provided with a lower impact rod (24), which is located inside the lower impact hole; The driving inclined surface (31) is a frustum-shaped surface, and the driven inclined surface is in contact with the driving inclined surface (31).

4. The liquefied air energy storage rock-breaking device for tunnel excavation according to claim 2 or 3, characterized in that, The impact tube (2) is also provided with multiple pressure relief holes (23). The pressure relief holes (23) penetrate the side wall of the impact tube (2) and communicate with the piston hole (21). The pressure relief holes (23) are located above the transverse impact holes.

5. The liquefied air energy storage rock-breaking device for tunnel excavation according to claim 4, characterized in that, The tensioning sleeve (6) is sleeved on the connecting shaft (13). The tensioning sleeve (6) is a hydraulic expansion sleeve. The hydraulic expansion sleeve has an annular hydraulic expansion cavity inside. One end of the hydraulic expansion sleeve has an inlet, and an inlet pipe (61) is connected to the inlet. A one-way valve is provided on the inlet, and a drain port is provided on the expansion sleeve. An overflow valve is provided on the drain port. Multiple embedded protrusions are provided on the outside of the expansion sleeve. The embedded protrusions are used to embed into the inner wall of the rock-breaking hole (8) under the action of liquid expansion.

6. The liquefied air energy storage rock breaking device for tunnel excavation according to claim 5, characterized in that, The connecting shaft (13) is also provided with a fastening shaft, the outer wall of the fastening shaft is provided with a fastening thread, the fastening shaft is provided with a fixing thread sleeve (7), the fixing thread sleeve (7) is provided on the fastening shaft, and the lower end of the fixing thread sleeve (7) presses against the tensioning sleeve (6); the connecting shaft (13) is a frustum shaft with a thin upper end and a thick lower end, and the inner wall of the tensioning sleeve (6) is a frustum surface that mates with the outer surface of the frustum shaft; The connecting shaft (13) is provided with a wire hole in the axial direction. A connecting wire (5) is provided in the wire hole. The connecting wire (5) is connected to the heating element (4). The connecting wire (5) extends to the outside of the bursting tube (1).

7. The liquefied air energy storage rock breaking device for tunnel excavation according to claim 1, characterized in that, The heating element (4) is a gradually changing resistance spiral heating wire. The gradually changing resistance spiral heating wire is spirally wound along the axial direction of the bursting tube (1). The wire diameter of the gradually changing resistance spiral heating wire increases continuously from top to bottom along the axial direction, and the resistance value decreases sequentially from top to bottom along the axial direction, forming a three-segment gradient distribution.

8. The liquefied air energy storage rock breaking device for tunnel excavation according to claim 7, characterized in that, The three-segment gradient distribution is divided into an upper high-resistance segment, a middle medium-resistance segment, and a lower low-resistance segment.

9. The liquefied air energy storage rock-breaking device for tunnel excavation according to claim 2, characterized in that, The rupture disc (12) is made of a nickel-based high-temperature alloy.

10. The liquefied air energy storage rock-breaking device for tunnel excavation according to claim 9, characterized in that, The rupture disc (12) has a diameter of 80 mm, a thickness of 3 mm, and a safety threshold of 15 MPa.

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