Frequency-adjustable self-vibration pulse cavitation jetting nozzle and combined rock breaking and tunneling equipment thereof

Abstract

The present application belongs to the technical field of tunneling device, and provides a tunable frequency self-vibration pulse cavitation jet nozzle and combined rock breaking tunneling equipment thereof. The tunable frequency self-vibration pulse cavitation jet nozzle comprises an upper nozzle and a lower nozzle, a plurality of first connecting pieces are arranged on the outer circumferential surface of the upper nozzle, a plurality of second connecting pieces are arranged on the lower nozzle, and the first connecting pieces are connected with the second connecting pieces to form a self-vibration cavity between the upper nozzle and the lower nozzle. The axial cavity length of the self-vibration cavity is determined by adjusting the distance between the first connecting pieces and the second connecting pieces. The lower nozzle adopts a contraction-expansion type cavitation nozzle. The self-vibration pulse cavitation jet nozzle is adjustable, the jet frequency is changed by adjusting the axial cavity length of the nozzle, so that the equipment has a wider frequency selection range when facing different rock bodies, and can adapt to the frequency optimization problem of the TBM under different rotating speeds.

Description

Technical Field

[0001] This invention belongs to the technical field of tunneling equipment, specifically relating to a frequency-adjustable self-vibrating pulse cavitation jet nozzle and its combined rock-breaking tunneling equipment. Background Technology

[0002] The statements in this section are merely background information related to the present invention and do not necessarily constitute prior art.

[0003] Currently, there has been extensive research on pulsed jets both domestically and internationally, yielding numerous meaningful results. However, most current pulsed jets are of fixed size, with an inherently non-adjustable structure. When the engineering environment changes and the jet's frequency parameters need improvement, replacing each nozzle individually will inevitably impact project progress and increase costs. Furthermore, wear on the pulsed nozzle primarily occurs at the lower nozzle; replacing the entire nozzle due to lower nozzle wear would further increase project costs. Therefore, considering the characteristics and needs of current underground space engineering projects, and to meet the frequency conversion requirements during underground space expansion, designing pulsed jet nozzles with adjustable frequencies and replaceable parts is highly significant.

[0004] Currently, designs for combined jet and TBM rock-breaking cutterheads exist, such as those published in CN112483105A and CN110735646A. The rock-breaking efficiency of pulsed jets is significantly affected by lithology, lateral velocity, and the natural frequency of the rock mass, requiring adjustments to pulse parameters to adapt to changing working conditions. However, the aforementioned designs do not consider the changes in jet parameters when the TBM encounters sudden changes in geological formations and alters the tunneling method. Furthermore, multiple nozzles are typically arranged at different installation radii within the cutterhead, and these nozzles exhibit significant differences in linear velocity. This necessitates parameter adjustments for different nozzles under the same pump pressure to achieve efficient rock breaking. Therefore, the aforementioned patents also lack consideration for the collaborative operation of multiple pulse nozzles. Summary of the Invention

[0005] To address the aforementioned problems, this invention proposes an adjustable frequency self-oscillating pulse cavitation jet nozzle and its combined rock-breaking tunneling equipment. The self-oscillating pulse cavitation jet nozzle is adjustable, and the jet frequency can be changed by adjusting the axial cavity length of the nozzle. This allows the equipment to have a wider range of frequency selection when facing different rock masses, and can also adapt to the frequency optimization problem of TBM at different rotation speeds.

[0006] According to some embodiments, the present invention adopts the following technical solution:

[0007] In a first aspect, the present invention provides a frequency-adjustable self-oscillating pulse cavitation jet nozzle.

[0008] A frequency-adjustable self-vibrating pulse cavitation jet nozzle includes an upper nozzle and a lower nozzle. The outer circumferential surface of the upper nozzle is provided with a plurality of first connecting members, and the lower nozzle is provided with a plurality of second connecting members. After the first connecting members and the second connecting members are connected, a self-vibrating cavity is formed between the upper nozzle and the lower nozzle.

[0009] The axial cavity length of the self-vibrating cavity is determined by adjusting the distance between the first connecting member and the second connecting member;

[0010] The lower nozzle is a contraction-expansion type cavitation nozzle.

[0011] Furthermore, the upper nozzle and the lower nozzle are connected by a rotation;

[0012] Furthermore, the rotary connection is a threaded connection, with external threads on the outer circumferential surface of the upper nozzle and internal threads on the inner circumferential surface of the lower nozzle.

[0013] Furthermore, the axial cavity length of the self-vibrating cavity is equal to the thickness of the first connecting member, the thickness of the second connecting member, and the distance between the first ear plate and the second ear plate.

[0014] Furthermore, the first connector adopts a first lug, and the second connector adopts a second lug.

[0015] Furthermore, the first ear plate and the second ear plate are fastened together by bolts and nuts;

[0016] Furthermore, the first ear plate and the second ear plate are fastened together by screws and nuts;

[0017] Furthermore, the first ear plate and the second ear plate are fastened together by screws and nuts.

[0018] Furthermore, the first connector is a threaded groove, and the second connector is a screw hole, with the threaded groove and the screw hole connected by bolts.

[0019] Furthermore, the axial cavity length of the self-vibrating cavity is determined based on the jet frequency.

[0020] Furthermore, the axial cavity length of the self-resonating cavity, determined based on the jet frequency, is determined using the following formula:

[0021]

[0022] Among them, D c L represents the circumferential cavity length of the self-resonating cavity. c f represents the axial cavity length of the self-resonating cavity; j The structure frequency of the jet is represented by N; the modal number is represented by N = 1, 2, 3…; u is represented by the jet velocity; U crepresents the convection velocity of the jet within the cavity; c represents the local sound wave velocity.

[0023] Secondly, the present invention provides a combined rock-breaking device with a frequency-adjustable self-oscillating pulse cavitation jet nozzle.

[0024] A combined rock-breaking device with a frequency-adjustable self-oscillating pulse cavitation jet nozzle includes a cutterhead on which a roller cutter and the frequency-adjustable self-oscillating pulse cavitation jet nozzle described in the first aspect are provided.

[0025] Furthermore, the cutter head is connected to a high-pressure pipeline via a rotary mechanism. The high-pressure pipeline is connected to a high-pressure water pump. The high-pressure water pump is connected to both the water supply system and the air supply system. A switch is installed on the high-pressure pipeline. The switch is connected to the air supply system, the high-pressure water pump, the abrasive supply system, and the external control system.

[0026] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0027] This invention, while enabling frequency adjustment of the pulse nozzle for different working conditions, couples the pulse jet with the cavitation effect, ultimately forming a variable frequency pulse cavitation jet nozzle. This provides a wider range of frequency selection for the jet when facing different rock masses, and solves the problems of mechanical adaptation and frequency optimization. This design overcomes the difficulties of replacing traditional integrated pulse nozzles, high costs, and inability to meet the frequency conversion requirements of practical engineering, greatly improving the practicality and rock-breaking efficiency of the jet. The self-oscillating pulse cavitation jet nozzle is adjustable; the jet frequency is changed by adjusting the axial cavity length of the self-oscillating chamber, ensuring precise adjustment of the axial cavity length.

[0028] This invention employs a frequency-adjustable self-vibrating pulse cavitation jet nozzle to generate a pulsed jet. The cutting effect of the pulsed abrasive jet is coupled with the compressive-shear effect of the roller cutter via a cutterhead, enabling efficient rock-breaking by the TBM in hard rock areas. The self-vibrating pulse cavitation jet nozzle allows for precise adjustment of the cavity length to change the jet frequency, achieving different frequencies for different rock types and different speeds. The combined rock-breaking equipment can be a water jet-TBM tunneling system or a water jet-shield tunneling system. Attached Figure Description

[0029] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0030] Figure 1 This is a schematic diagram of the adjustable frequency self-oscillating pulse cavitation jet nozzle shown in Embodiment 1 of the present invention;

[0031] Figure 2This is a top view of the frequency-adjustable self-oscillating pulse cavitation jet nozzle shown in Embodiment 1 of the present invention;

[0032] Figure 3 This is a schematic diagram of a conventional self-vibrating nozzle structure shown in Embodiment 1 of the present invention;

[0033] Figure 4 This is a schematic diagram of the combined rock-breaking equipment structure of the adjustable frequency self-oscillating pulse cavitation jet nozzle shown in Embodiment 2 of the present invention.

[0034] Figure 5 This is a schematic diagram of the cutter head structure shown in Embodiment 2 of the present invention. Detailed Implementation

[0035] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0036] It should be noted that the following detailed descriptions are exemplary and intended to provide further illustration of the invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0037] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of exemplary embodiments according to the invention. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the term "comprising" is used in this specification, it indicates the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0038] In this invention, terms such as "fixed connection," "connected," and "linked" should be interpreted broadly, indicating a fixed connection, an integral connection, or a detachable connection; a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can determine the specific meaning of these terms in this invention based on the specific circumstances, and they should not be construed as limitations on the invention.

[0039] Example 1

[0040] This embodiment provides a frequency-adjustable self-oscillating pulse cavitation jet nozzle.

[0041] A frequency-adjustable self-vibrating pulse cavitation jet nozzle includes an upper nozzle and a lower nozzle. The outer peripheral surface of the upper nozzle is provided with a plurality of first connecting members, and the lower nozzle is provided with a plurality of second connecting members. After the first connecting members and the second connecting members are connected, a self-vibrating cavity is formed between the upper nozzle and the lower nozzle.

[0042] The axial cavity length of the self-vibrating cavity is determined by adjusting the distance between the first connecting member and the second connecting member;

[0043] The lower nozzle is a contraction-expansion type cavitation nozzle.

[0044] As one or more embodiments, the upper nozzle and the lower nozzle are rotatably connected;

[0045] As one or more embodiments, the rotary connection is a threaded connection, with external threads on the outer circumferential surface of the upper nozzle and internal threads on the inner circumferential surface of the lower nozzle.

[0046] As one or more embodiments, the axial cavity length of the self-vibrating cavity is equal to the thickness of the first connecting member, the thickness of the second connecting member, and the distance between the first ear plate and the second ear plate.

[0047] In one or more embodiments, the first connector uses a first ear plate, and the second connector uses a second ear plate.

[0048] As one or more embodiments, the first ear plate and the second ear plate are fastened together by bolts and nuts;

[0049] In one or more embodiments, the first ear plate and the second ear plate are fastened together by screws and nuts;

[0050] In one or more embodiments, the first ear plate and the second ear plate are fastened together by screws and nuts.

[0051] In one or more embodiments, the first connector is a threaded groove, the second connector is a screw hole, and the threaded groove and the screw hole are connected by bolts.

[0052] The axial cavity length of the self-vibrating cavity can be adjusted by rotating the lower nozzle. The upper nozzle is provided with a threaded groove for a fixing screw. The screw head is stuck in the groove. The position of the screw relative to the lower nozzle can be adjusted by moving the screw. After aligning the screw with the screw hole of the lower nozzle, the screw cap is tightened. The lower nozzle is provided with a screw hole every 60° to fix the screw of the upper nozzle.

[0053] like Figure 1 As shown, the self-oscillating pulse cavitation jet nozzle is divided into two parts: an upper nozzle and a lower nozzle. Figure 2 The continuous jet generated by the high-pressure water pump enters through the upper nozzle. The upper and lower nozzles are connected by a threaded rotation and tightened by screws designed on both sides of the nozzles. The jet enters the self-vibrating cavity through the upper nozzle, generating a pulse effect, and forms a cavitation effect at the outlet section of the lower nozzle, thus forming a self-vibrating pulsed cavitation jet.

[0054] Figure 3 The image shows a traditional one-piece self-oscillating pulse nozzle; in contrast, Figure 1The self-oscillating pulse cavitation jet nozzle shown can change the jet frequency by adjusting the axial cavity length and the circumferential cavity length of the self-oscillating cavity. At the same time, the contraction-expansion type design at the lower nozzle can generate a reverse jet inside the flow channel, thereby causing the jet to produce a cavitation effect, and finally generating a pulse cavitation jet. The coupling of the pulse effect and the cavitation effect enhances the rock-breaking effect of the jet.

[0055] The characteristic frequency of a pulsed jet comprises three parts: the jet frequency, the cavity's natural frequency, and the cavity's turbulence frequency. The circumferential cavity length D of the self-resonating cavity can be derived from the formula. c With respect to the axial cavity length L of the self-vibrating cavity c The ratio calculation formula is based on formula (1), which shows that the axial cavity length L of the self-vibrating cavity is... c The variations are typically within millimeters, thus requiring precise adjustment of the cavity length over a small range. Based on this consideration, this embodiment implements a continuously adjustable cavity length design. Furthermore, according to formula (1), the jet frequency f... j Also related to the circumferential cavity length D of the self-vibrating cavity c Relatedly, the internal spiral design of the lower nozzle in this design provides it with more space to adjust the cavity diameter.

[0056] In this embodiment, the nozzle has two parts, the upper and lower, each with a protrusion on its outer side. Each protrusion has a ring of screw tracks and six screw holes. When the protrusions are assembled, their length is equal to the length of the self-vibrating cavity. During use, when adjusting the circumferential length of the self-vibrating cavity according to the required frequency, the required circumferential length is calculated using formula (1). After removing all screws from the outer side of the nozzle, a vernier caliper is used to measure the length of the protruding part on the outer side of the nozzle to reach the required length. At this point, the internal cavity length of the nozzle is the calculated circumferential length of the self-vibrating cavity. Finally, all screws are installed and tightened. Simultaneously, by adjusting the nozzle mounting module, the angle between the pulse jet and the tunnel face can be changed, improving the jet rock-breaking efficiency to achieve the optimal rock-breaking specific energy in conjunction with the roller cutter.

[0057]

[0058] Among them, D c L represents the circumferential cavity length of the self-resonating cavity. c f represents the axial cavity length of the self-resonating cavity; j The structure frequency of the jet is represented by N; the modal number is represented by N = 1, 2, 3…; u is represented by the jet velocity; U c represents the convection velocity of the jet within the cavity; c represents the local sound wave velocity.

[0059] Example 2

[0060] This embodiment provides a combined rock-breaking device with a frequency-adjustable self-oscillating pulse cavitation jet nozzle.

[0061] A combined rock-breaking device with a frequency-adjustable self-oscillating pulse cavitation jet nozzle includes a cutterhead, on which a roller cutter and the frequency-adjustable self-oscillating pulse cavitation jet nozzle described in Embodiment 1 are provided.

[0062] Furthermore, the cutter head is connected to a high-pressure pipeline via a rotary mechanism. The high-pressure pipeline is connected to a high-pressure water pump. The high-pressure water pump is connected to both the water supply system and the air supply system. A switch is installed on the high-pressure pipeline. The switch is connected to the air supply system, the high-pressure water pump, the abrasive supply system, and the external control system.

[0063] like Figure 4 As shown, a combined rock-breaking equipment with an adjustable frequency self-oscillating pulse cavitation jet nozzle includes a high-pressure jet generating device (high-pressure water pump, switch, water supply system, high-pressure pipeline), an abrasive supply device, a high-pressure air pump, a rotary mechanism, a control switch, and a TBM cutter head (disc cutter, jet mounting module). The air pump is connected to the high-pressure water pump through a pipeline to provide high-pressure air to the high-pressure water pump. The abrasive supply device is connected to the high-pressure water pump through a sand pipe and the high-pressure pipeline to provide abrasive for the jet. The high-pressure water pump is externally connected to the high-pressure pipeline and is connected to the cutter head through the rotary mechanism to provide high-pressure jet to the cutter head. A switch is installed in the middle of the high-pressure pipeline, and the switch is connected to the air pump. The switch is opened and closed by the high-pressure air and controlled by the control system.

[0064] like Figure 5 As shown, the TBM cutterhead is equipped with a roller cutter and jet mounting module. A certain gap is reserved around the roller cutter and jet mounting module, and their positions can be adjusted according to needs. Depending on the relative positions of the roller cutter and jet after adjustment, it can be changed to the same trajectory and different trajectory rock breaking modes.

[0065] Because frequency has a significant impact on rock-breaking efficiency during jet rock breaking, studies have shown that the optimal jet rock-breaking effect is achieved when the jet frequency is close to the natural frequency of the rock mass, with the nozzle stationary. Due to the different nozzle positions installed on the TBM, the linear velocity of the nozzles will vary considerably at a given cutterhead rotation speed. This necessitates timely adjustment of the frequency parameters of the nozzles installed on the cutterhead. Furthermore, nozzle replacement is quite cumbersome in actual use; therefore, this combined rock-breaking equipment employs variable frequency pulse jet nozzles.

[0066] In operation, the high-pressure jet system is first activated, the high-pressure water pump begins pressurization, and the high-pressure air pump and abrasive supply equipment start working simultaneously. Then, the cutter head begins operation, the jet switch is opened, and the high-pressure jet is ejected from the nozzles on the cutter head via a rotating mechanism. The abrasive system supplies abrasive, and the pulsed jets at the nozzles mix to form a pulsed abrasive jet. The jet strikes the rock mass, creating grooves and microcracks. The roller cutter then penetrates further to crush the rock mass, and this process is repeated until the rock-breaking process is complete. Notably, because the pulse frequency can be varied within a wide range by adjusting the nozzle cavity length, the rock-breaking efficiency can be improved according to changes in lithology.

[0067] This embodiment combines pulsed abrasive jets with roller cutters to achieve combined rock breaking using a pulsed jet-TBM system. This solves the problems of high difficulty, high cost, and slow speed associated with traditional purely mechanical rock breaking in hard rock areas. The pulsed jet replaces the continuous jet, avoiding the stagnation pressure problem inherent in continuous jets and improving the jet's impact force and rock-breaking efficiency. The pulsed jet nozzle is adjustable; the jet frequency is changed by adjusting the nozzle's cavity length. This provides the equipment with a wider frequency selection range when facing different rock masses and adapts to the frequency optimization issues of the TBM at different speeds. Furthermore, the sliding rail bolt mounting slot design of the upper nozzle and the design that the length of the nozzle's outer edge protrusion is equal to the axial cavity length of the self-vibrating chamber ensure precise adjustment of the cavity length. The roller cutters and jet mounting modules on the cutter head are provided with sufficient movement space for testing under various combined working conditions, such as same-track rock breaking and different-track rock breaking.

[0068] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A frequency-adjustable self-oscillating pulse cavitation jet nozzle, characterized in that, It includes an upper nozzle and a lower nozzle. The outer circumferential surface of the upper nozzle is provided with a plurality of first connecting members, and the lower nozzle is provided with a plurality of second connecting members. After the first connecting members and the second connecting members are connected, a self-vibrating cavity is formed between the upper nozzle and the lower nozzle. The axial cavity length of the self-vibrating cavity is determined by adjusting the distance between the first connecting member and the second connecting member; The lower nozzle is a contraction-expansion type cavitation nozzle; The axial cavity length of the self-resonating cavity is determined based on the jet frequency using the following formula: in, D c This indicates the circumferential cavity length of the self-resonating cavity; L c This indicates the axial cavity length of the self-resonating cavity; f j Indicates the structural frequency of the jet; N Represents the number of modes. N =1,2,3…; u Indicates the jet velocity; U c This indicates the convection velocity of the jet within the cavity; c This indicates the local sound wave speed.

2. The frequency-adjustable self-oscillating pulse cavitation jet nozzle according to claim 1, characterized in that, The upper nozzle and the lower nozzle are connected by a rotation; Alternatively, the rotary connection can be a threaded connection, with external threads on the outer circumferential surface of the upper nozzle and internal threads on the inner circumferential surface of the lower nozzle.

3. The frequency-adjustable self-oscillating pulse cavitation jet nozzle according to claim 1, characterized in that, The axial cavity length of the self-vibrating cavity = the thickness of the first connector + the thickness of the second connector + the distance between the first ear plate and the second ear plate.

4. The frequency-adjustable self-oscillating pulse cavitation jet nozzle according to claim 1, characterized in that, The first connector uses a first lug, and the second connector uses a second lug.

5. The frequency-adjustable self-oscillating pulse cavitation jet nozzle according to claim 4, characterized in that, The first ear plate and the second ear plate are fastened together by bolts and nuts; Alternatively, the first ear plate and the second ear plate are fastened together by screws and nuts; Alternatively, the first ear plate and the second ear plate are fastened together by screws and nuts.

6. The frequency-adjustable self-oscillating pulse cavitation jet nozzle according to claim 1, characterized in that, The first connector is a threaded groove, and the second connector is a screw hole. The threaded groove and the screw hole are connected by bolts.

7. A combined rock-breaking device with a frequency-adjustable self-oscillating pulse cavitation jet nozzle, characterized in that, It includes a cutter head, on which a roller cutter and a frequency-adjustable self-oscillating pulse cavitation jet nozzle as described in any one of claims 1-6 are provided.

8. The combined rock-breaking equipment with the adjustable frequency self-oscillating pulse cavitation jet nozzle according to claim 7, characterized in that, The cutter head is connected to a high-pressure pipeline via a rotary mechanism. The high-pressure pipeline is connected to a high-pressure water pump. The high-pressure water pump is connected to both a water supply system and a gas supply system. A switch is installed on the high-pressure pipeline. The switch is connected to the gas supply system, the high-pressure water pump, the abrasive supply system, and an external control system.

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