A double-wall pipe for dual-fuel ships and its construction process

Abstract

The present invention relates to the technical field of special ship manufacturing, and in particular to a double-walled pipe for dual-fuel ships and a construction process thereof, wherein the double-walled pipe for dual-fuel ships includes an inner pipe, an outer pipe and an elastic support unit. The outer pipe is sleeved on the periphery of the inner pipe, and an annular cavity is formed between the two. The elastic support unit is accommodated in the annular cavity and is used as a flexible connection transition between the outer pipe and the inner pipe. In the process of conveying combustible gas, when the inner pipe is excited at high frequency due to the action of airflow fluctuations, the elastic support unit always applies an elastic pushing force to it. In this way, on the one hand, the instantaneous acceleration and instantaneous displacement generated by the inner pipe when it is subjected to the action of high-frequency exciting force are effectively reduced, thereby ensuring that the working noise is reduced to below the allowable design value; on the other hand, the excitation strength of the inner pipe itself is effectively controlled, thereby preventing fatigue from easily occurring in the annular weld for butt connection thereon.

Description

Technical Field

[0001] The invention relates to the technical field of special ship manufacturing, in particular to a double-wall pipe for a dual-fuel ship and a construction process thereof. Background Art

[0002] In recent years, the shipbuilding and offshore engineering industry has actively responded to the national energy conservation and emission reduction policies and vigorously developed green ship technologies. As the future trend of ocean-going shipbuilding, the design and construction of dual-fuel propulsion ships continue to move towards a high degree of automation, energy conservation and environmental protection, and have inspired a large number of large and medium-sized shipyards to focus on the market development of dual-fuel propulsion ships. Recently, China Merchants Jinling Dingheng Ship (Yangzhou) Co., Ltd. and Jiangsu University of Science and Technology jointly developed the world's first ammonia-powered dual-fuel special stainless steel chemical tanker, and have already implemented construction.

[0003] Double-walled pipes are installed in ammonia-powered dual-fuel special stainless steel chemical ships, and they are used to transport combustible gases such as ammonia and hydrogen to gas generators. In accordance with the specifications of IMO and classification societies, double-walled pipes are designed with double-layer pipe walls to eliminate the risk of leakage and fire and explosion caused by defects such as pipeline welding. The inner pipeline is used for gas transportation, and a fan is installed in the cavity between the inner pipeline and the outer pipeline. In this way, when the inner pipeline is damaged, the leaked gas is immediately pumped out to an open-air safe area by the exhaust fan. However, in actual applications, the following problems occur: during the transportation of combustible gases, the pumping pressure is difficult to maintain at a constant value, and the inner pipe is bound to be excited at high frequency due to the unbalanced gas pressure. As a result, on the one hand, during the high-frequency excitation of the inner pipe, the friction between the pipe wall and the air is bound to cause noise. In addition, the inner pipe is completely surrounded by the outer pipe, and the working noise will be further amplified under the influence of the cavity effect; on the other hand, due to the high-frequency excitation force, the annular welds between adjacent inner pipes are prone to fatigue, and the welding microcracks are more likely to expand into large cracks, thereby greatly increasing the risk of leakage of combustible gases. Therefore, technical personnel are urgently needed to solve the above problems. Summary of the invention

[0004] Therefore, in view of the above existing problems and defects, the research team of the present invention collected relevant information, conducted multiple evaluations and considerations, and continuously experimented and modified the research team, which ultimately led to the emergence of the dual-fuel marine double-walled pipe.

[0005] In order to solve the above technical problems, the present invention relates to a dual-fuel marine double-wall pipe, which includes an inner pipe, an outer pipe and an elastic support unit. The inner pipe is connected to the gas generator set to transport combustible gas thereto. The outer pipe is sleeved on the periphery of the inner pipe, and an annular cavity is formed between the two. The elastic support unit is partially or wholly accommodated in the annular cavity and is used as a flexible connection transition between the outer pipe and the inner pipe. When the inner pipe vibrates at a high frequency due to the action of the exciting force, the elastic pushing force applied by the elastic support unit on its outer side wall changes adaptively.

[0006] As a further improvement of the technical solution disclosed in the present invention, the elastic support unit is composed of a plurality of elastic support sub-units linearly arranged along the central axis of the outer pipe.

[0007] As a further improvement of the technical solution disclosed in the present invention, the elastic support subunit is a first elastic support assembly. The first elastic support assembly includes a first special-shaped piece, a second special-shaped piece, a first fastening bolt assembly and a second fastening bolt assembly. The first special-shaped piece and the second special-shaped piece are reversely buckled, and are fixed as a whole by the first fastening bolt assembly and the second fastening bolt assembly. The first special-shaped piece is composed of a first supporting section, a first connecting transition section, a first arc-shaped embracing section, a second connecting transition section and a first arc-shaped elastic section in sequence. The second special-shaped piece is composed of a second supporting section, a third connecting transition section, a second arc-shaped embracing section, a fourth connecting transition section and a second arc-shaped elastic section in sequence. When the first special-shaped piece and the second special-shaped piece are assembled, the first supporting section and the second supporting section are correspondingly contacted on the fourth connecting transition section and the second connecting transition section, and the first arc-shaped embracing section and the second arc-shaped embracing section can be jointly expanded into a cylindrical embracing cavity adapted to the outer diameter of the inner pipe. When the first elastic support assembly is assembled relative to the inner pipe, the first arc-shaped elastic segment and the second arc-shaped elastic segment are maintained in an elastically compressed deformation state due to the reverse force from the inner wall of the outer pipe.

[0008] As a further improvement of the technical solution disclosed in the present invention, the first elastic support assembly also includes a first arc-shaped anti-wear pad, a second arc-shaped anti-wear pad, a first countersunk screw and a second countersunk screw. The first arc-shaped anti-wear pad is abutted against the outer wall of the first arc-shaped elastic section, and is removably fixed to the first arc-shaped elastic section as a whole by the first countersunk screw. The second arc-shaped anti-wear pad is abutted against the outer wall of the second arc-shaped elastic section, and is removably fixed to the second arc-shaped elastic section as a whole by the second countersunk screw. When the first elastic support assembly is assembled relative to the inner pipe, the first arc-shaped anti-wear pad and the second arc-shaped anti-wear pad both directly touch the inner wall of the outer pipe.

[0009] As a further improvement of the technical solution disclosed in the present invention, the first elastic support assembly also includes a first elastic rubber pad and a second elastic rubber pad. The first elastic rubber pad is detachably fixed to the first special-shaped member and completely covers the first arc-shaped embracing section. The second elastic rubber pad is detachably fixed to the second special-shaped member and completely covers the second arc-shaped embracing section. When the first elastic support assembly is assembled relative to the inner pipe, the first elastic rubber pad and the second elastic rubber pad are maintained in an elastically compressed deformation state due to the extrusion force from the outer wall of the inner pipe.

[0010] Of course, as another modified design of the above technical solution, the elastic support subunit is composed of a plurality of second elastic support components uniformly distributed circumferentially around the central axis of the inner pipe. The second elastic support component may also include a first mounting seat, a second mounting seat, a third mounting seat, a first connecting rod mechanism, a second connecting rod mechanism, a first posture reset device, a second posture reset device and a pressure block. Along the radial direction of the inner pipe, the first mounting seat, the second mounting seat, and the third mounting seat are arranged in sequence in the annular cavity, and the central axes of the three are colinear. The first mounting seat is supported by the outer pipe. The first connecting rod mechanism connects the first mounting seat and the second mounting seat at the same time. The second connecting rod mechanism connects the second mounting seat and the third mounting seat at the same time. The pressure block and the third mounting seat are fixed as one, and they are always elastically pressed against the outer wall of the inner pipe. The first posture reset device and the second posture reset device are respectively used in a one-to-one correspondence with the first connecting rod mechanism and the second connecting rod mechanism. When the second elastic support component is assembled, in the process that the inner pipe is displaced toward the outer pipe due to the exciting force, the pressure block in the corresponding area is displaced toward the first mounting seat due to the pressing force, the first connecting rod mechanism is compressed due to the axial pressure, the elastic potential energy stored in the first posture reset device is synchronously increased, and the spacing distance L1 between the first mounting seat and the second mounting seat is correspondingly reduced. At the same time, the second connecting rod mechanism is also compressed due to the axial pressure, the elastic potential energy stored in the second posture reset device is synchronously increased, and the spacing distance L2 between the second mounting seat and the third mounting seat is correspondingly reduced. In this process, the pressure block is pushed up by the axial The first position reset device is configured to be actuated by the first and second position reset devices, and the first and second position reset devices are configured to be actuated by the first and second position reset devices. The first and second position reset devices are configured to be actuated by the first and second position reset devices, and the first and second position reset devices are configured to be actuated by the first and second position reset devices. The first and second position reset devices are configured to be actuated by the first and second position reset devices, and the first and second position reset devices are configured to be actuated by the first and second position reset devices. The first and second position reset devices are configured to be actuated by the first and second position reset devices, and the first and second position reset devices are configured to be actuated by the first and second position reset devices. The first and second position reset devices are configured to be actuated by the first and second position reset devices, and the first and second position reset devices are configured to be actuated by the first and second position reset devices. The first and second position reset devices are configured to be actuated by the first and second position reset devices, and the first and second position reset devices are configured to be actuated by the first and second position reset devices.

[0011] As a further improvement of the technical solution disclosed in the present invention, the first link mechanism is composed of N first link assemblies that are circumferentially evenly distributed around the central axis of the first mounting seat and are simultaneously connected between the first mounting seat and the second mounting seat. The second link mechanism is composed of N second link assemblies that are axially evenly distributed around the central axis of the second mounting seat and are simultaneously connected between the second mounting seat and the third mounting seat. In the process of the inner pipe performing displacement movement toward / away from the outer pipe due to the action of the exciting force, the first link assembly and the second link assembly are adaptively bent and deformed.

[0012] As a further improvement of the technical solution disclosed in the present invention, an arc-shaped top contact surface matching the outer side wall of the inner pipe is formed on the pressing block.

[0013] As a further improvement of the technical solution disclosed in the present invention, the first connecting rod assembly includes a first upper connecting rod, a first articulated seat, and a first lower connecting rod. The first upper connecting rod and the first lower connecting rod are both freely swingably hinged to the first articulated seat. The second connecting rod assembly includes a second upper connecting rod, a second articulated seat, and a second lower connecting rod. The second upper connecting rod and the second lower connecting rod are both freely swingably hinged to the second articulated seat. In the process of the inner pipe performing displacement movement toward / backward to the outer pipe due to the action of the exciting force, the angle α formed between the first upper connecting rod and the first lower connecting rod and the angle β formed between the second upper connecting rod and the second lower connecting rod change adaptively.

[0014] As a further improvement of the technical solution disclosed in the present invention, the first posture resetting device includes a first connecting transition block and N first tension springs. The first connecting transition block is arranged between the first mounting seat and the second mounting seat, and is surrounded by a plurality of first connecting rod assemblies. The inner ends of the N first tension springs are fixed to the first connecting transition block, and the outer ends are fixed to the N first hinged seats one by one. The second posture resetting device includes a second connecting transition block and N second tension springs. The second connecting transition block is arranged between the second mounting seat and the third mounting seat, and is surrounded by a plurality of second connecting rod assemblies. The inner ends of the N second tension springs are fixed to the second connecting transition block, and the outer ends are fixed to the N second hinged seats one by one.

[0015] Of course, as another modified design of the above technical solution, the first posture reset device includes a first compression spring. The first compression spring is elastically compressed between the first mounting seat and the second mounting seat. The second posture reset device includes a second compression spring. The second compression spring is elastically compressed between the second mounting seat and the third mounting seat. When the second elastic support assembly is assembled, in the process of the inner pipe performing displacement movement toward the outer pipe due to the action of the exciting force, the first compression spring and the second compression spring are compressed due to the axial pressure to store elastic potential energy; and in the process of the inner pipe performing displacement movement opposite to the outer pipe due to the action of the exciting force, the elastic potential energy stored in the first compression spring and the second compression spring is released synchronously.

[0016] As a further improvement of the technical solution disclosed in the present invention, the second elastic support assembly further includes a linear motion element, which is used to drive the first mounting seat to perform linear displacement movement toward / away from the inner pipe, and is supported by the outer pipe.

[0017] Compared with the dual-fuel ship double-wall pipe of the traditional design structure, in the technical solution disclosed in the present invention, the outer pipe and the inner pipe are connected and transitioned by means of an elastic support unit. In the process of conveying combustible gas, when the inner pipe is excited at high frequency due to the action of air flow fluctuation, the elastic support unit always applies an elastic push force to it, and the magnitude and direction of the elastic push force at a certain moment can be adaptively adjusted according to the excitation intensity and excitation direction. In this way, on the one hand, the instantaneous acceleration and instantaneous displacement generated by the inner pipe when it is subjected to the high-frequency excitation force are effectively reduced, which means that the friction strength between its pipe wall and the air is reduced, thereby ensuring that the working noise is reduced to below the allowable design value; on the other hand, under the continuous action of the elastic push force, the excitation strength of the inner pipe itself is effectively controlled, and the annular weld used for butt joint is not easy to fatigue, avoiding the occurrence of cracks on the side wall of the inner pipe during the normal service life, or even premature disconnection, ensuring that the combustible gas is continuously, stably and safely conveyed to the gas generator set over a fairly long period of time.

[0018] In addition, the present invention also discloses a construction process, which is applicable to the above-mentioned dual-fuel ship double-walled pipe, which is formed by sequentially splicing and welding multiple sections of double-walled pipe segments. The preparation of double-walled pipe segments includes the following steps:

[0019] S1. Prepare an inner pipe and an outer pipe of equal length. Insert the inner pipe into the outer pipe;

[0020] S2. Adjust the relative position of the inner pipe and maintain its temporary posture by means of temporary support to ensure that its central axis coincides with the central axis of the outer pipe;

[0021] S3, installing a plurality of elastic support sub-units in sequence in the annular cavity;

[0022] S4, respectively adjusting the postures of the multiple elastic support subunits to ensure that the outer side wall of the inner pipe is acted upon by the elastic force;

[0023] S5. Remove temporary supports.

[0024] As a further improvement of the technical solution disclosed in the present invention, welding tooling is used to implement the welding operation of two adjacent inner pipes.

[0025] The welding tooling includes a first fastener, a second fastener, a third fastening bolt assembly and a fourth fastening bolt assembly. The first fastener is formed by connecting the first wing section, the third arc-shaped embracing section and the second wing section in sequence. A first avoidance gap for the welding gun to extend into is cut on the third arc-shaped embracing section. The second fastener is formed by connecting the third wing section, the fourth arc-shaped embracing section and the fourth wing section in sequence. A second avoidance gap for the welding gun to extend into is cut on the fourth arc-shaped embracing section. The first mounting hole and the third mounting hole that are compatible with the third fastening bolt assembly are opened one by one on the first wing section and the third wing section. The second mounting hole and the fourth mounting hole that are compatible with the fourth fastening bolt assembly are opened one by one on the second wing section and the fourth wing section. After the two adjacent inner pipes are butt-jointed, the first fastener and the second fastener are both fastened thereon, and it is ensured that the first avoidance notch and the second avoidance notch are aligned with the butt joint, the first mounting hole is aligned with the third mounting hole, and the second mounting hole is aligned with the fourth mounting hole. Then, the third fastening bolt assembly and the fourth fastening bolt assembly are inserted at the same time and tightened.

[0026] As a further improvement of the technical solution disclosed in the present invention, the welding tool also includes a first insulation pad and a second insulation pad. The first insulation pad and the second insulation pad are respectively matched with the third arc-shaped embracing section and the fourth arc-shaped embracing section in a one-to-one correspondence. When the welding tool is installed in place relative to the two adjacent inner pipes, the first insulation pad is elastically pressed between the third arc-shaped embracing section and the outer side wall of the inner pipe, and the second insulation pad is elastically pressed between the fourth arc-shaped embracing section and the outer side wall of the inner pipe.

[0027] Through the application of the above technical solution, on the one hand, the total working hours and costs required for the construction operation of the double-walled pipe for dual-fuel ships can be effectively reduced; on the other hand, in the specific construction operation, with the help of temporary support, it can be ensured that the inner pipe always occupies the correct relative position in the cavity of the outer pipe, which can not only effectively ensure that the elastic support subunit can be quickly and correctly installed, but also ensure that it is continuously subjected to the effect of stable elastic pushing force during the actual work process. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0029] Figure 1 It is a three-dimensional schematic diagram of a first embodiment of a double-walled pipe for dual-fuel ships in the present invention.

[0030] Figure 2 It is a three-dimensional schematic diagram of the first elastic support assembly in the first embodiment of the dual-fuel marine double-walled pipe of the present invention.

[0031] Figure 3 It is a front view of the first elastic support assembly in the first embodiment of the dual-fuel marine double-walled pipe of the present invention.

[0032] Figure 4 It is a three-dimensional schematic diagram of the first special-shaped part in the first embodiment of the double-walled pipe for dual-fuel ships of the present invention.

[0033] Figure 5 It is a three-dimensional schematic diagram of the second special-shaped part in the first embodiment of the double-walled pipe for dual-fuel ships of the present invention.

[0034] Figure 6 It is a perspective schematic diagram of a second embodiment of a double-walled pipe for dual-fuel ships in the present invention.

[0035] Figure 7 It is a three-dimensional schematic diagram of the second elastic support assembly in the second embodiment of the dual-fuel marine double-walled pipe of the present invention.

[0036] Figure 8 It is a front view of the second elastic support assembly in the second embodiment of the dual-fuel marine double-walled pipe of the present invention.

[0037] Fig. 9 It is a three-dimensional schematic diagram of the first connecting rod assembly in the second embodiment of the dual-fuel marine double-walled pipe of the present invention.

[0038] Fig.10 It is a three-dimensional schematic diagram of the second connecting rod assembly in the second embodiment of the dual-fuel marine double-walled pipe of the present invention.

[0039] Fig.11 It is a three-dimensional schematic diagram of a first attitude resetting device in a second embodiment of a dual-fuel marine double-walled pipe of the present invention.

[0040] Fig.12 It is a three-dimensional schematic diagram of a second posture resetting device in a second embodiment of a dual-fuel marine double-walled pipe of the present invention.

[0041] Fig.13 It is a three-dimensional schematic diagram of a third embodiment of a double-walled pipe for dual-fuel ships in the present invention.

[0042] Fig.14 It is a three-dimensional schematic diagram of the second elastic support assembly in the third embodiment of the dual-fuel marine double-walled pipe of the present invention.

[0043] Fig.15 It is a perspective schematic diagram of a fourth embodiment of a dual-fuel marine double-walled pipe of the present invention.

[0044] Fig.16 It is a front view of a fourth embodiment of a double-walled pipe for dual-fuel ships in the present invention.

[0045] Fig.17 The diagram is a schematic diagram of the state when the dual-fuel marine double-wall pipe segments and the inner pipe are connected and welded in the present invention.

[0046] Fig.18 The invention is a three-dimensional schematic diagram of welding tools used when the dual-fuel ship double-wall pipe segments are connected to the inner pipe and welded.

[0047] Fig.19 It is a three-dimensional schematic diagram of the first fastener used in the welding tooling when the dual-fuel ship double-wall pipe segment is connected with the inner pipe and welded in the present invention.

[0048] Fig. 20 It is a three-dimensional schematic diagram of a second fastener used in a welding tool when a dual-fuel ship double-wall pipe segment is connected to an inner pipe and welded.

[0049] 1-inner pipe; 2-outer pipe; 3-elastic support unit; 31-elastic support subunit; 311-first elastic support assembly; 3111-first special-shaped member; 31111-first top section; 31112-first connecting transition section; 31113-first arc-shaped embracing section; 31114-second connecting transition section; 31115-first arc-shaped elastic section; 3112-second special-shaped member; 31121-second top section; 31122-third connecting transition section; 31123-second arc-shaped embracing section; 31124-fourth connecting transition section 31125-second arc-shaped elastic section; 3113-first fastening bolt assembly; 3114-second fastening bolt assembly; 3115-first arc-shaped anti-wear pad; 3116-second arc-shaped anti-wear pad; 3117-first countersunk screw; 3118-second countersunk screw; 312-second elastic support assembly; 3121-first mounting seat; 3122-second mounting seat; 3123-third mounting seat; 3124-first connecting rod mechanism; 31241-first connecting rod assembly; 312411-first upper connecting rod; 3124 12-first hinge seat; 312413-first lower connecting rod; 3125-second connecting rod mechanism; 31251-second connecting rod assembly; 312511-second upper connecting rod; 312512-second hinge seat; 312513-second lower connecting rod; 3126-first attitude reset device; 31261-first connecting transition block; 31262-first tension spring; 31263-first compression spring; 3127-second attitude reset device; 31271-second connecting transition block; 31272-second tension spring; 31273-second Compression spring; 3128-pressure block; 31281-arc-shaped top contact surface; 3129-pneumatic cylinder; 4-welding tooling; 41-first fastener; 411-first wing section; 412-third arc-shaped embracing section; 4121-first avoidance gap; 413-second wing section; 42-second fastener; 421-third wing section; 422-fourth arc-shaped embracing section; 4221-second avoidance gap; 423-fourth wing section; 43-third fastening bolt assembly; 44-fourth fastening bolt assembly; 45-first thermal insulation pad; 46-second thermal insulation pad. DETAILED DESCRIPTION

[0050] In the description of the present invention, it is necessary to understand that the directions or positional relationships indicated by the terms "front", "rear", "up", "down", "left", "right", etc. are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as a limitation on the present invention.

[0051] The following is a further detailed description of the present invention in conjunction with specific embodiments. Figure 1The three-dimensional schematic diagram of the first embodiment of the dual-fuel ship double-walled pipe in the present invention is shown. It can be seen that it is mainly composed of several parts such as an inner pipe 1, an outer pipe 2 and an elastic support unit 3. Among them, the inner pipe 1 is connected to the gas generator set to transport combustible gas (ammonia or hydrogen, etc.) to it. The outer pipe 2 is sleeved on the periphery of the inner pipe 1, and an annular cavity is formed between the two. Considering the two factors of ensuring high structural strength and avoiding excessive damage due to corrosion, the inner pipe 1 and the outer pipe 2 are preferably made of stainless steel or alloy steel (including titanium alloy and Hastelloy) with good corrosion resistance. The elastic support unit 3 is accommodated in the annular cavity as a whole and is used as a flexible connection transition between the outer pipe 2 and the inner pipe 1. The elastic support unit 3 is composed of a plurality of elastic support sub-units 31 linearly arranged along the central axis of the outer pipe 2. In the process of transporting combustible gas, when the inner pipe 1 is excited at high frequency due to airflow fluctuations, each elastic supporting subunit 31 always applies an elastic pushing force to it, and the size and direction of the elastic pushing force generated at a certain moment can be adaptively adjusted according to the excitation intensity and excitation direction.

[0052] By adopting the above technical solution, the dual-fuel marine double-wall pipe has achieved at least the following two beneficial technical effects in practical application, which are as follows:

[0053] 1) Effectively reduce the instantaneous acceleration and instantaneous displacement of the inner pipe 1 when it is subjected to high-frequency exciting force, which means that the friction strength between the pipe wall and the air is reduced, thereby ensuring that the working noise is reduced to below the allowable design value;

[0054] 2) Under the continuous action of the elastic pushing force, the excitation strength of the inner pipe 1 itself is effectively controlled, so that the annular weld used for butt joint is not prone to fatigue, avoiding the occurrence of cracks on the side wall of the inner pipe 1 or even premature disconnection during its normal service life, ensuring that the combustible gas is continuously, stably and safely transported to the gas generator set over a fairly long period of time.

[0055] As is known, according to design common sense, the elastic support subunit 31 can adopt a variety of design structures to achieve elastic pushing of the outer wall of the inner pipe 1. However, an implementation scheme with a simple design structure, easy manufacturing and implementation, and convenient for subsequent replacement and maintenance operations is recommended here. The specific implementation scheme is as follows: The main body of the elastic support subunit 31 is the first elastic support component 311 (to facilitate distinction from the second elastic support component 312 that appears later). Figure 2 , 3As shown in , the first elastic support assembly 311 is mainly composed of a first special-shaped member 3111, a second special-shaped member 3112, a first fastening bolt assembly 3113 and a second fastening bolt assembly 3114. The first special-shaped member 3111 and the second special-shaped member 3112 are both sheet metal bending parts. When performing the assembly operation, the two are reversely buckled and fixed as a whole by the first fastening bolt assembly 3113 and the second fastening bolt assembly 3114. Figure 4 As shown in , the first special-shaped member 3111 is sequentially composed of a first supporting section 31111, a first connecting transition section 31112, a first arc-shaped embracing section 31113, a second connecting transition section 31114 and a first arc-shaped elastic section 31115. Figure 5 As shown in the figure, the second special-shaped member 3112 is composed of the second top section 31121, the third connecting transition section 31122, the second arc-shaped embracing section 31123, the fourth connecting transition section 31124 and the second arc-shaped elastic section 31125 in sequence. When the first special-shaped member 3111 and the second special-shaped member 3112 are assembled, the first top section 31111 and the second top section 31121 are correspondingly contacted with the fourth connecting transition section 31124 and the second connecting transition section 31114, and the first arc-shaped embracing section 31113 and the second arc-shaped embracing section 31123 can be jointly expanded into a cylindrical embracing cavity adapted to the outer diameter of the inner pipe 1. When the first elastic support component 311 is assembled relative to the inner pipe 1, the first arc-shaped elastic section 31115 and the second arc-shaped elastic section 31125 are maintained in an elastically compressed deformation state due to the reverse force from the inner side wall of the outer pipe 2. In the process of transporting combustible gas, when the inner pipe 1 is excited at high frequency due to the fluctuation of airflow, the first arc-shaped elastic segment 31115 and the second arc-shaped elastic segment 31125 are deformed due to the pressure and store a large amount of elastic potential energy. At the same time, the first arc-shaped elastic segment 31115 and the second arc-shaped elastic segment 31125 always apply an elastic pushing force to the outer wall of the inner pipe 1, and the stored elastic potential energy is released.

[0056] It should be noted that the first special-shaped member 3111 and the second special-shaped member 3112 are preferably made of carbon spring steel or alloy spring steel with good bending strength and self-restoring performance. In this way, when the inner pipe 1 is excited at high frequency due to air flow fluctuations, it is beneficial to ensure that the first arc-shaped elastic section 31115 and the second arc-shaped elastic section 31125 have extremely fast response speeds when subjected to pressure, thereby ensuring that the elastic push force applied to the inner pipe 1 is compatible with the process of high-frequency exciting force generation.

[0057] Furthermore, since the structural strength of the first special-shaped member 3111 and the second special-shaped member 3112 made of spring steel is significantly higher than that of the outer pipe 2 made of stainless steel, in long-term use, the inner wall of the outer pipe 2 is easily damaged by rigid friction, which will not only greatly reduce its own service life, but also the first arc-shaped elastic section 31115 and the second arc-shaped elastic section 31125 are subjected to uneven wear in each area, resulting in the elastic push force generated by them. The strength and direction are difficult to meet the design requirements. In view of this, as a further optimization of the above technical solution, if Figure 2 , 3 As shown in , the first elastic support assembly 311 is additionally provided with a first arc-shaped anti-wear pad 3115, a second arc-shaped anti-wear pad 3116, a first countersunk screw 3117 and a second countersunk screw 3118. The first arc-shaped anti-wear pad 3115 is attached to the outer wall of the first arc-shaped elastic section 31115, and is detachably fixed to the first arc-shaped elastic section 31115 by the first countersunk screw 3117. The second arc-shaped anti-wear pad 3116 is attached to the outer wall of the second arc-shaped elastic section 31125, and is detachably fixed to the second arc-shaped elastic section 31125 by the second countersunk screw 3118. When the first elastic support assembly 311 is assembled relative to the inner pipe 1, the first arc-shaped anti-wear pad 3115 and the second arc-shaped anti-wear pad 3116 are directly in contact with the inner wall of the outer pipe 2. In actual application, the first arc-shaped anti-wear pad 3115 is always arranged between the first arc-shaped elastic section 31115 and the inner wall of the outer pipe 2, and the second arc-shaped anti-wear pad 3116 is always arranged between the second arc-shaped elastic section 31125 and the inner wall of the outer pipe 2, thereby effectively preventing the inner wall of the outer pipe 2 from being worn due to direct rigid scraping.

[0058] In addition, since the structural strength of the first special-shaped member 3111 and the second special-shaped member 3112 made of spring steel is significantly higher than that of the inner pipe 1 made of stainless steel, in long-term use, the outer wall of the inner pipe 1 is easily damaged by rigid friction, which not only greatly reduces its own service life, but also the first arc-shaped embracing section 31113 and the second arc-shaped embracing section 31123 become unstable due to uneven wear in each area, which leads to the elastic push force generated by the first arc-shaped elastic section 31115 and the second arc-shaped elastic section 31125. The strength and direction of the elastic push force are difficult to meet the design requirements. In view of this, as a further optimization of the above technical solution, the first elastic support component 311 is further provided with a first elastic rubber pad and a second elastic rubber pad (not shown in the figure). The first elastic rubber pad is detachably fixed to the first special-shaped member 3111 and completely covers the first arc-shaped embracing section 31113. The second elastic rubber pad is detachably fixed to the second special-shaped member 3112 and completely covers the second arc-shaped embracing section 31123. When the first elastic support component 311 is assembled relative to the inner pipe 1, the first elastic rubber pad and the second elastic rubber pad are kept in an elastically compressed deformation state due to the squeezing force from the outer wall of the inner pipe 1. It is also necessary to explain here that due to the addition of the first elastic rubber pad and the second elastic rubber pad, the friction force pre-applied by the first special-shaped member 3111 and the second special-shaped member 3112 to the outer wall of the inner pipe 1 can be effectively increased, thereby preventing the first elastic support component 311 from moving along the inner pipe 1 due to the axial excitation force, which is conducive to ensuring that each first elastic support component 311 always maintains a correct relative position, thereby ensuring that the elastic push force value and direction pre-applied to the outer wall of the inner pipe 1 are consistent with the expected design.

[0059] Figure 6 The figure shows a perspective schematic diagram of the second embodiment of the dual-fuel ship double-walled pipe of the present invention. It can be seen that the difference between the second embodiment and the first embodiment is that the elastic support subunit 31 is composed of a plurality of second elastic support components 312 uniformly distributed around the central axis of the inner pipe 1. Figure 7As shown in the figure, the second elastic support assembly 312 is mainly composed of a first mounting seat 3121, a second mounting seat 3122, a third mounting seat 3123, a first connecting rod mechanism 3124, a second connecting rod mechanism 3125, a first attitude reset device 3126, a second attitude reset device 3127 and a pressing block 3128. Among them, along the radial direction of the inner pipe 1, the first mounting seat 3121, the second mounting seat 3122, and the third mounting seat 3123 are arranged in sequence and at intervals in the annular cavity, and the central axes of the three are colinear. The first mounting seat 3121 is fixed on the inner side wall of the outer pipe 2. The first connecting rod mechanism 3124 simultaneously connects the first mounting seat 3121 and the second mounting seat 3122. The second connecting rod mechanism 3125 simultaneously connects the second mounting seat 3122 and the third mounting seat 3123. The pressing block 3128 and the third mounting seat 3123 are detachably fixed as a whole, and they are always elastically pressed against the outer side wall of the inner pipe 1. The first posture resetting device 3126 and the second posture resetting device 3127 are respectively matched with the first connecting rod mechanism 3124 and the second connecting rod mechanism 3125 in a one-to-one correspondence.

[0060] By adopting the above technical solution, when the second elastic support component 312 is assembled, in the process that the inner pipe 1 performs displacement movement toward the outer pipe 2 due to the excitation force, the pressure block 3128 in the corresponding area performs displacement movement toward the first mounting seat 3121 due to the pressing force, the first connecting rod mechanism 3124 is compressed due to the axial pressure, the elastic potential energy stored in the first posture reset device 3126 is synchronously increased, and the spacing distance L1 between the first mounting seat 3121 and the second mounting seat 3122 is correspondingly reduced. At the same time, the second connecting rod mechanism 3125 is also compressed due to the axial pressure, the elastic potential energy stored in the second posture reset device 3127 is synchronously increased, and the spacing distance L2 between the second mounting seat 3122 and the third mounting seat 3123 is correspondingly reduced. In this process, the pressure The block 3128 is always pressed against the outer wall of the inner pipe 1 due to the axial pushing force; or, in the process of the inner pipe 1 moving away from the outer pipe 2 due to the exciting force, the elastic potential energy stored in the first posture reset device 3126 is released, and the first connecting rod mechanism 3124 is axially stretched and reset due to the elastic restoring force, and the distance L1 between the first mounting seat 3121 and the second mounting seat 3122 is increased accordingly. At the same time, the elastic potential energy stored in the second posture reset device 3127 is also released synchronously, and the second connecting rod mechanism 3125 is axially stretched and reset due to the elastic restoring force, and the distance L2 between the second mounting seat 3122 and the third mounting seat 3123 is increased accordingly. In this process, the pressing block 3128 is always pressed against the outer wall of the inner pipe 1 due to the axial pushing force.

[0061] It should be noted that, in order to ensure that the pressing block 3128 can be stably and reliably pressed against the outer wall of the inner pipe 1, and thus ensure that the elastic pushing force can be correctly transmitted, Figure 7 As shown in , an arc-shaped top contact surface 3128 adapted to the outer side wall of the inner pipe 1 is formed thereon.

[0062] As a further refinement of the above technical solution, Figure 7 As shown in , the first link mechanism 3124 is composed of four first link assemblies 31241 that are evenly distributed around the central axis of the first mounting seat 3121 and are simultaneously connected between the first mounting seat 3121 and the second mounting seat 3122. The second link mechanism 3125 is composed of four second link assemblies 31251 that are evenly distributed around the central axis of the second mounting seat 3122 and are simultaneously connected between the second mounting seat 3122 and the third mounting seat 3123. In the process of the inner pipe 1 performing displacement movement toward / away from the outer pipe 2 due to the action of the exciting force, the spacing distance L1 between the first mounting seat 3121 and the second mounting seat 3122 and the spacing distance L2 between the second mounting seat 3122 and the third mounting seat 3123 change accordingly, thereby causing the first link assembly 31241 and the second link assembly 31251 to bend and deform adaptively.

[0063] Furthermore, by Figure 8 , 9 As shown in the figure, both the first connecting rod assembly 31241 and the second connecting rod assembly 31251 adopt a double connecting rod design. The first connecting rod assembly 31241 is mainly composed of several parts such as the first upper connecting rod 312411, the first articulated seat 312412 and the first lower connecting rod 312413. The first upper connecting rod 312411 and the first lower connecting rod 312413 can be freely swung and hinged to the first articulated seat 312412. The second connecting rod assembly 31251 is mainly composed of several parts such as the second upper connecting rod 312511, the second articulated seat 312512 and the second lower connecting rod 312513. The second upper connecting rod 312511 and the second lower connecting rod 312513 can be freely swung and hinged to the second articulated seat 312512. In the process of the inner pipe 1 performing displacement movement toward / against the outer pipe 2 due to the exciting force, the spacing distance L1 between the first mounting seat 3121 and the second mounting seat 3122 and the spacing distance L2 between the second mounting seat 3122 and the third mounting seat 3123 change accordingly, and the angle α formed between the first upper connecting rod 312411 and the first lower connecting rod 312413 and the angle β formed between the second upper connecting rod 312511 and the second lower connecting rod 312513 change adaptively.

[0064] As a further refinement of the above technical solution, combined with the attached Figure 7 , 10 As shown in the figure, the first posture restoring device 3126 mainly includes a first connecting transition block 31261 and four first tension springs 31262. The first connecting transition block 31261 is arranged between the first mounting seat 3121 and the second mounting seat 3122, and is surrounded by a plurality of first connecting rod assemblies 31241. The inner ends of the four first tension springs 31262 are fixed to the first connecting transition block 31261, and the outer ends are fixed to the four first hinge seats 312412 one by one. Figure 7 , 11 As shown in the figure, the second posture restoring device 3127 includes a second connection transition block 31271 and four second tension springs 31272. The second connection transition block 31271 is arranged between the second mounting seat 3122 and the third mounting seat 3123, and is surrounded by a plurality of second connecting rod assemblies 31251. The inner ends of the four second tension springs 31272 are fixed to the second connection transition block 31271, and the outer ends are fixed to the four second hinge seats 312512 one by one. In actual applications, after the second elastic support component 312 is assembled, when the inner pipe 1 performs displacement movement toward / away from the outer pipe 2 due to the excitation force, the spacing distance L1 between the first mounting seat 3121 and the second mounting seat 3122 changes accordingly, and the telescopic length of the first tension spring 31262 also changes adaptively. At the same time, the spacing distance L2 between the second mounting seat 3122 and the third mounting seat 3123 changes accordingly, and the telescopic length of the second tension spring 31272 also changes adaptively, ensuring that the outer wall of the inner pipe 1 is always subjected to a stable elastic pushing force, ultimately ensuring that its excitation intensity is always maintained within a reasonable value range.

[0065] Fig.13 The figure shows a three-dimensional schematic diagram of a third embodiment of a double-walled dual-fuel marine pipe according to the present invention. Fig.14The third embodiment of the dual-fuel marine double-walled pipe of the present invention is shown in a three-dimensional schematic diagram of the second elastic support assembly. It can be seen that compared with the second embodiment, the second elastic support assembly 312 included in the two adopts a similar design structure, and the only difference is that the first attitude reset device 3126 is preferably a first compression spring 31263. The first compression spring 31263 is elastically compressed between the first mounting seat 3121 and the second mounting seat 3122. The second attitude reset device 3127 is preferably a second compression spring 31273. The second compression spring 31273 is elastically compressed between the second mounting seat 3122 and the third mounting seat 3123. When the second elastic support assembly 312 is assembled, in the process of the inner pipe 1 performing displacement movement toward the outer pipe 2 due to the action of the exciting force, the first compression spring 31263 and the second compression spring 31273 are compressed due to the axial pressure to store elastic potential energy; and in the process of the inner pipe 1 performing displacement movement away from the outer pipe 2 due to the action of the exciting force, the elastic potential energy stored in the first compression spring 31263 and the second compression spring 31273 is released synchronously, ensuring that the outer wall of the inner pipe 1 is always subjected to the action of a stable elastic pushing force, and finally ensuring that its excitation intensity is always maintained within a reasonable value range.

[0066] Fig.15 , Fig.16 The three-dimensional schematic diagram and the front view of the fourth embodiment of the dual-fuel ship double-walled pipe of the present invention are respectively shown. It can be seen that, regardless of the specific design structure of the second elastic support component 312, the difference between it and the second embodiment and the third embodiment is that the second elastic support component 312 is further provided with a pneumatic cylinder 3129. The pneumatic cylinder 3129 is used to drive the first mounting seat 3121 to perform linear displacement movement toward / backward to the outer wall of the inner pipe 1, and it is penetrated and fixed on the outer wall of the outer pipe 2. In this way, it can not only effectively ensure that the outer wall of the inner pipe 1 is always subjected to the effect of a stable elastic thrust force, but also expand the scope of application of the second elastic support component 312. The reason is that the second elastic support component 312 can be prefabricated as a component in the prefabrication workshop, and prefabricated in batches. At this stage, there is no need to consider the specific outer diameters of the pre-matched inner pipe 1 and the outer pipe 2. During the operation of inserting the second elastic support assembly 312 into the annular cavity, it is necessary to observe in real time whether each pressing block 3128 is stably and reliably pressed against the inner pipe 1. If not, the corresponding pneumatic cylinder 3129 is activated to drive the second elastic support assembly 312 to perform displacement movement toward / backward of the inner pipe 1 until the elastic push force generated by it is within the theoretical design range. Of course, when the outer diameter of the pre-constructed inner pipe 1 or outer pipe 2 changes, it can also be adjusted in accordance with the above method.

[0067] Here, the present invention also discloses a construction process, which is applicable to the above-mentioned dual-fuel ship double-walled pipe. The dual-fuel ship double-walled pipe is formed by sequentially splicing and welding multiple sections of double-walled pipe segments. The preparation of double-walled pipe segments includes the following steps:

[0068] S1. Prepare an inner pipe 1 and an outer pipe 2 of equal length. Insert the inner pipe 1 into the outer pipe 2;

[0069] S2. Adjust the relative position of the inner pipe 1 and maintain its temporary posture by means of temporary support to ensure that its central axis coincides with the central axis of the outer pipe 2;

[0070] S3, installing a plurality of elastic support subunits 311 (including the first elastic support component 31 and the second elastic support component 32 mentioned above) in the annular cavity in sequence;

[0071] S4, respectively adjusting the postures of the multiple elastic support subunits 311 to ensure that the outer wall of the inner pipe 1 is subjected to a reasonable elastic force;

[0072] S5. Remove temporary supports.

[0073] Through the application of the above technical solution, on the one hand, the total working hours and costs required for the construction of dual-fuel marine double-walled pipes can be effectively reduced; on the other hand, in specific construction operations, temporary support can be used to ensure that the inner pipe 1 always occupies the correct relative position in the annular cavity, which can not only effectively ensure that the elastic support subunit 311 can be quickly and correctly installed, but also ensure that it is continuously subjected to the action of a stable elastic pushing force during the actual work process.

[0074] In order to prevent the misalignment of the two pre-aligned segmented inner pipes 1 during the welding process and to ensure that the inner pipes 1 have good straightness after welding, in actual construction, it is preferred to use welding tools 4 to perform the welding operation of the two adjacent inner pipes 1. Fig.18 , 19As shown in Figures 20 and 21, the welding tool 4 is mainly composed of several parts such as a first fastener 41, a second fastener 42, a third fastening bolt assembly 43 and a fourth fastening bolt assembly 44. Among them, the first fastener 41 is sequentially connected by the first wing section 411, the third arc-shaped embracing section 412 and the second wing section 413. A first avoidance gap 4121 for the welding gun to extend into is cut on the third arc-shaped embracing section 412. The second fastener 42 is sequentially connected by the third wing section 421, the fourth arc-shaped embracing section 422 and the fourth wing section 423. A second avoidance gap 4221 for the welding gun to extend into is cut on the fourth arc-shaped embracing section 422. The first mounting hole and the third mounting hole adapted to the third fastening bolt assembly 43 are opened one by one on the first wing section 411 and the third wing section 421. The second wing section 413 and the fourth wing section 423 are provided with a second mounting hole and a fourth mounting hole which are matched with the fourth fastening bolt 44 assembly. When the adjacent double-walled pipe segments are assembled and formed (i.e. the segment inner pipe 1 is inserted relative to the segment outer pipe 2, and the elastic support subunit 311 has been accurately installed), the assembled inner pipe 1 is extended in advance, and the new segment inner pipe 1 is pre-joined to the double-walled pipe segment, and then the first fastener 41 and the second fastener 42 are both buckled thereon, and it is ensured that the first avoidance notch 4121 and the second avoidance notch 4221 are aligned with the butt joint, the first mounting hole is aligned with the third mounting hole, and the second mounting hole is aligned with the fourth mounting hole, and then the third fastening bolt assembly 43 and the fourth fastening bolt assembly 44 are inserted at the same time and screwed to tighten.

[0075] It is known that according to common welding knowledge, the quality of weld formation is not only related to the material of the base material, the material of the welding rod, the welding technique, the welding current, and the welding voltage, but also closely related to the output form of welding heat. Because welding tools 4 are required in the welding process, and welding tools 4 are usually made of metal materials with good thermal conductivity, and the specific installation position is inevitably biased, resulting in different welding heat dissipation rates and paths in different areas of the annular weld, which will inevitably lead to poor forming quality of the annular weld after forming. In view of this, as a further optimization of the above technical solution, if Fig.18 As shown in the figure, the welding tool 4 is additionally provided with a first insulation pad 45 and a second insulation pad 46. The first insulation pad 45 and the second insulation pad 46 are respectively and one-to-one matched with the third arc-shaped embracing section 412 and the fourth arc-shaped embracing section 422. When the welding tool 4 is installed in place relative to the two adjacent segmented inner pipes 1, the first insulation pad 45 is elastically pressed between the third arc-shaped embracing section 412 and the outer side wall of the inner pipe 1, and the second insulation pad 46 is elastically pressed between the fourth arc-shaped embracing section 422 and the outer side wall of the inner pipe 1.

[0076] Finally, it should be noted that when the external pipeline 2 is extended, the above-mentioned method can also be referred to for implementation, and the welding tooling 4 can be adaptively designed. In order to save space, it will not be described in detail here.

[0077] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A double-walled pipe for dual-fuel ships, characterized in that: It comprises an inner pipe, an outer pipe and an elastic support unit; the inner pipe is connected to the gas generator set to transport combustible gas thereto; the outer pipe is sleeved on the periphery of the inner pipe to form an annular cavity between the two; the elastic support unit is partially or entirely accommodated in the annular cavity and is used as a flexible connection transition between the outer pipe and the inner pipe; When the inner pipe vibrates at a high frequency due to the exciting force, the elastic pushing force applied by the elastic support unit on its outer wall changes adaptively; the elastic support unit is composed of a plurality of elastic support sub-units linearly arranged along the central axis of the outer pipe; the elastic support sub-unit is composed of a plurality of second elastic support components circumferentially uniformly distributed around the central axis of the inner pipe; the second elastic support component includes a first mounting seat, a second mounting seat, a third mounting seat, a first connecting rod mechanism, a second connecting rod mechanism, a first posture reset device, a second posture reset device and a pressure block; along the radial direction of the inner pipe, The first mounting seat, the second mounting seat, and the third mounting seat are sequentially arranged in the annular cavity at intervals, and the central axes of the three are collinear; the first mounting seat is supported by the outer pipe; the first connecting rod mechanism simultaneously connects the first mounting seat and the second mounting seat; the second connecting rod mechanism simultaneously connects the second mounting seat and the third mounting seat; the pressing block and the third mounting seat are fixed as a whole, and they are always elastically pressed against the outer side wall of the inner pipe; the first posture reset device and the second posture reset device are respectively matched with the first connecting rod mechanism and the second connecting rod mechanism in a one-to-one correspondence; When the second elastic support component is assembled, in the process that the inner pipe is displaced toward the outer pipe due to the exciting force, the pressure block in the corresponding area is displaced toward the first mounting seat due to the pressing force, the first connecting rod mechanism is compressed due to the axial pressure, the elastic potential energy stored in the first posture reset device is synchronously increased, and the spacing distance L1 between the first mounting seat and the second mounting seat is correspondingly reduced. At the same time, the second connecting rod mechanism is also compressed due to the axial pressure, the elastic potential energy stored in the second posture reset device is synchronously increased, and the spacing distance L2 between the second mounting seat and the third mounting seat is correspondingly reduced. In this process, the pressure block is The first position reset device is configured to be pressed against the outer wall of the inner pipe by the pushing force; or, in the process of the inner pipe moving away from the outer pipe due to the excitation force, the elastic potential energy stored in the first position reset device is released, the first connecting rod mechanism is axially stretched and reset due to the elastic restoring force, and the spacing distance L1 between the first mounting seat and the second mounting seat is increased accordingly. At the same time, the elastic potential energy stored in the second position reset device is also synchronously released, the second connecting rod mechanism is axially stretched and reset due to the elastic restoring force, and the spacing distance L2 between the second mounting seat and the third mounting seat is increased accordingly. In this process, the pressing block is always pressed against the outer wall of the inner pipe due to the axial pushing force; The first link mechanism includes a first upper link, a first hinge seat, and a first lower link; the first upper link and the first lower link are both freely swingably hinged to the first hinge seat; the second link mechanism includes a second upper link, a second hinge seat, and a second lower link; the second upper link and the second lower link are both freely swingably hinged to the second hinge seat; in the process of the inner pipe performing displacement movement toward / backward to the outer pipe due to the action of the exciting force, the angle α formed between the first upper link and the first lower link and the angle β formed between the second upper link and the second lower link are adaptively changed; The first posture reset device includes a first connecting transition block and N first tension springs; the first connecting transition block is arranged between the first mounting seat and the second mounting seat, and is surrounded by multiple first connecting rod mechanisms; the inner ends of the N first tension springs are fixed to the first connecting transition block, and the outer ends are fixed to the N first hinge seats one by one; the second posture reset device includes a second connecting transition block and N second tension springs; the second connecting transition block is arranged between the second mounting seat and the third mounting seat, and is surrounded by multiple second connecting rod mechanisms; the inner ends of the N second tension springs are fixed to the second connecting transition block, and the outer ends are fixed to the N second hinge seats one by one.

2. The dual-fuel marine double-wall pipe according to claim 1, characterized in that: The first link mechanism is composed of N first link mechanisms that are circumferentially evenly distributed around the central axis of the first mounting seat and are simultaneously connected between the first mounting seat and the second mounting seat; the second link mechanism is composed of N second link mechanisms that are axially evenly distributed around the central axis of the second mounting seat and are simultaneously connected between the second mounting seat and the third mounting seat; in the process of the inner pipe performing displacement movement toward / opposite to the outer pipe due to the action of the exciting force, the first link mechanism and the second link mechanism adaptively bend and deform.

3. The dual-fuel ship double-wall pipe according to claim 1, characterized in that: An arc-shaped top contact surface matched with the outer side wall of the inner pipe is formed on the pressing block.

4. The dual-fuel marine double-walled pipe according to any one of claims 1 to 3, characterized in that: The first posture reset device includes a first compression spring; the first compression spring is elastically compressed between the first mounting seat and the second mounting seat; the second posture reset device includes a second compression spring; the second compression spring is elastically compressed between the second mounting seat and the third mounting seat; when the second elastic support assembly is assembled, in the process of the inner pipe performing displacement movement toward the outer pipe due to the action of the exciting force, the first compression spring and the second compression spring are compressed due to the axial pressure to store elastic potential energy; and in the process of the inner pipe performing displacement movement away from the outer pipe due to the action of the exciting force, the elastic potential energy stored in the first compression spring and the second compression spring is released synchronously.

5. The dual-fuel marine double-wall pipe according to any one of claims 1 to 3, characterized in that: The second elastic support assembly also includes a linear motion element; the linear motion element is used to drive the first mounting seat to perform linear displacement movement toward / away from the inner pipe, and the linear motion element is supported by the outer pipe.

6. A construction process, applicable to the dual-fuel marine double-wall pipe as claimed in any one of claims 1 to 3, characterized in that: The dual-fuel ship double-walled pipe is formed by sequentially splicing and welding multiple double-walled pipe segments; the preparation of the double-walled pipe segments includes the following steps: S1. Prepare the inner pipe and the outer pipe of equal length; insert the inner pipe into the outer pipe; S2. Adjust the relative position of the inner pipe and maintain its temporary posture by means of temporary support to ensure that its central axis coincides with the central axis of the outer pipe; S3, installing the plurality of elastic support sub-units in sequence in the annular cavity; S4, respectively adjusting the postures of the plurality of elastic supporting subunits to ensure that the outer side wall of the inner pipe is acted upon by elastic force; S5. Remove temporary supports.

7. The construction process according to claim 6, characterized in that: Using welding tools to carry out welding of two adjacent inner pipes; The welding tool comprises a first fastener, a second fastener, a third fastening bolt assembly and a fourth fastening bolt assembly; the first fastener is sequentially connected by a first wing section, a third arc-shaped embracing section and a second wing section; a first avoidance gap for a welding gun to extend into is cut on the third arc-shaped embracing section; the second fastener is sequentially connected by a third wing section, a fourth arc-shaped embracing section and a fourth wing section; a second avoidance gap for a welding gun to extend into is cut on the fourth arc-shaped embracing section; a first fastening bolt assembly adapted to the third fastening bolt assembly is provided on the first wing section and the third wing section in a one-to-one correspondence. a first mounting hole and a third mounting hole; a second mounting hole and a fourth mounting hole matched with the fourth fastening bolt assembly are opened on the second wing section and the fourth wing section respectively; when the two adjacent inner pipes are butt-jointed, the first clip and the second clip are both fastened thereon, and it is ensured that the first avoidance gap and the second avoidance gap are aligned with the butt joint, the first mounting hole is aligned with the third mounting hole, and the second mounting hole is aligned with the fourth mounting hole, and then, the third fastening bolt assembly and the fourth fastening bolt assembly are inserted at the same time and tightened.

8. The construction process according to claim 7, characterized in that: The welding tool also includes a first insulation pad and a second insulation pad; the first insulation pad and the second insulation pad are respectively and one-to-one matched with the third arc-shaped embracing section and the fourth arc-shaped embracing section; when the welding tool is installed in place relative to the two adjacent inner pipes, the first insulation pad is elastically pressed between the third arc-shaped embracing section and the outer side wall of the inner pipe, and the second insulation pad is elastically pressed between the fourth arc-shaped embracing section and the outer side wall of the inner pipe.

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