A cooling system for steel pipe welding and a method of using the same

Abstract

The present application relates to the technical field of steel pipe welding, in particular to a cooling system for steel pipe welding and a using method thereof, which comprises a cooling liquid circulating system and a heat exchange cylinder sleeved on the outside of the steel pipe to be welded, and the heat exchange cylinder is arranged close to the welding end of the steel pipe to be welded; the inner wall of the heat exchange cylinder is provided with a groove arranged around the axis of the steel pipe to be welded, and the outer wall of the steel pipe to be welded and the groove wall enclose a sealed cavity; the sealed cavity is provided with a liquid inlet and a liquid outlet, the liquid inlet is communicated with the liquid outlet end of the cooling liquid circulating system, and the liquid outlet is communicated with the liquid return end of the cooling liquid circulating system; by introducing cooling liquid into the first sealed cavity, the steel pipe to be welded can be cooled, and the cooling liquid directly contacts with the outer wall of the steel pipe to be welded, which ensures the heat exchange efficiency between the cooling liquid and the steel pipe to be welded, guarantees the cooling effect, reduces the welding construction time of the steel pipe, and further shortens the shipbuilding period.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of steel pipe welding, in particular to a cooling system for steel pipe welding and a using method thereof. BACKGROUND

[0002] The gas pipeline of the liquefied gas carrier needs to be welded by multiple segments of austenitic stainless steel pipes. During the welding process of the austenitic stainless steel pipe, if the temperature of the weld area is kept at the dangerous temperature range of 450 DEG C to 850 DEG C for a long time, intergranular corrosion of the weld and the surrounding austenitic stainless steel will occur. The intergranular corrosion starts from the surface of the metal and develops along the grain boundary to the interior of the grain, greatly weakening the bonding force between the grains and reducing the strength of the material. In severe cases, the mechanical strength of the material can be completely lost. Moreover, after the intergranular corrosion of the austenitic stainless steel occurs, there is no obvious change in appearance, which is difficult to be found during routine maintenance. However, the strength of the material has been greatly reduced, which can cause sudden failure of the austenitic stainless steel pipe and lead to gas leakage, posing a great safety hazard.

[0003] The gas pipeline of the liquefied gas carrier needs to be welded by multiple segments of austenitic stainless steel pipes. During the welding process of the austenitic stainless steel pipe, if the temperature of the weld area is kept at the dangerous temperature range of 450 DEG C to 850 DEG C for a long time, intergranular corrosion of the weld and the surrounding austenitic stainless steel will occur. The intergranular corrosion starts from the surface of the metal and develops along the grain boundary to the interior of the grain, greatly weakening the bonding force between the grains and reducing the strength of the material. In severe cases, the mechanical strength of the material can be completely lost. Moreover, after the intergranular corrosion of the austenitic stainless steel occurs, there is no obvious change in appearance, which is difficult to be found during routine maintenance. However, the strength of the material has been greatly reduced, which can cause sudden failure of the austenitic stainless steel pipe and lead to gas leakage, posing a great safety hazard.

[0004] However, there are a large number of gas pipelines that need to be welded on the liquefied gas carrier, and the welding voltage and current are small, and the dwell time between the welding passes is too long, which greatly increases the welding construction man-hours of the gas pipeline of the liquefied gas carrier and prolongs the shipbuilding construction period. SUMMARY

[0005] The technical problem to be solved by the present application is that the welding voltage and current are small, and the dwell time between the welding passes is too long when welding the gas pipeline of the liquefied gas carrier, which greatly increases the welding construction man-hours of the gas pipeline of the liquefied gas carrier and prolongs the shipbuilding construction period.

[0006] In order to solve the above technical problems, the purpose of the present application is to provide a cooling system for steel pipe welding, which comprises a cooling liquid circulation system and a heat exchange cylinder sleeved outside the steel pipe to be welded, the heat exchange cylinder being arranged close to the welding end of the steel pipe to be welded.

[0007] The inner wall of the heat exchange cylinder is provided with a groove arranged around the axis of the steel pipe to be welded, and the outer side wall of the steel pipe to be welded and the groove wall enclose a first sealed cavity; the first sealed cavity is provided with a liquid inlet and a liquid outlet, the liquid inlet is communicated with the liquid outlet end of the cooling liquid circulating system, and the liquid outlet is communicated with the liquid return end of the cooling liquid circulating system.

[0008] As a preferred solution, the liquid return end of the cooling liquid circulating system is provided with a temperature gauge.

[0009] As a preferred solution, the heat exchange cylinder comprises a first flange plate, a first elastic sealing ring, a cylinder body, a second elastic sealing ring and a second flange plate, the groove is arranged in the cylinder body, and the first flange plate, the first elastic sealing ring, the cylinder body, the second elastic sealing ring and the second flange plate are sequentially sleeved on the outer side of the steel pipe to be welded.

[0010] The first flange plate and the cylinder body are connected by a first fastening structure, the first fastening structure drives the first flange plate to move towards the cylinder body to extrude the first elastic sealing ring, so that the inner wall of the first elastic sealing ring abuts against the outer side wall of the steel pipe to be welded.

[0011] The second flange plate and the cylinder body are connected by a second fastening structure, the second fastening structure drives the second flange plate to move towards the cylinder body to extrude the second elastic sealing ring, so that the inner wall of the second elastic sealing ring abuts against the outer side wall of the steel pipe to be welded.

[0012] As a preferred solution, one end of the cylinder body close to the first elastic sealing ring is provided with a first limiting groove, the first elastic sealing ring is arranged in the first limiting groove, and the first flange plate is provided with a first annular boss at the end opposite to the cylinder body, the first annular boss is inserted into the first limiting groove.

[0013] One end of the cylinder body close to the second elastic sealing ring is provided with a second limiting groove, the second elastic sealing ring is arranged in the second limiting groove, and the second flange plate is provided with a second annular boss at the end opposite to the cylinder body, the second annular boss is inserted into the second limiting groove.

[0014] As a preferred solution, the heat exchange cylinder comprises a first half-cylinder body and a second half-cylinder body which are detachably connected to form a cylinder, the inner wall of the first half-cylinder body is provided with a first groove section, the inner wall of the second half-cylinder body is provided with a second groove section, and the first groove section and the second groove section are spliced to form the groove.

[0015] As a preferred solution, the steel pipes to be welded include a first steel pipe and a second steel pipe, the welding end of the first steel pipe and the welding end of the second steel pipe are oppositely arranged, and the outer side of the first steel pipe and the outer side of the second steel pipe are both sleeved with the heat exchange cylinder;

[0016] The cooling system for steel pipe welding includes a first pipe body and a second pipe body, the first end of the first pipe body is inserted into the lumen of the first steel pipe, the outer side of the first end of the first pipe body is sleeved with a first annular capsule, the outer circumferential side of the first annular capsule is attached to the inner side wall of the first steel pipe, and the second end of the first pipe body is in communication with a cooling gas supply system;

[0017] The first end of the second pipe body is inserted into the lumen of the second steel pipe, the outer side of the first end of the second pipe body is sleeved with a second annular capsule, the outer circumferential side of the second annular capsule is attached to the inner side wall of the second steel pipe, and the second end of the second pipe body is in communication with an exhaust system.

[0018] As a preferred solution, the cooling gas supply system includes a liquefied argon tank, and the second end of the first pipe body is in communication with the gas outlet of the liquefied argon tank.

[0019] A method for using the above-mentioned cooling system for steel pipe welding includes the following steps:

[0020] Step S1: sleeving the heat exchange cylinder on the welding end of the first steel pipe and the welding end of the second steel pipe;

[0021] Step S2: welding the welding end of the first steel pipe and the welding end of the second steel pipe;

[0022] Step S3: removing the heat exchange cylinder.

[0023] As a preferred solution, the step S1 further includes:

[0024] placing the first pipe body and the first annular capsule in the first steel pipe, inflating the first annular capsule so that the outer circumferential side of the first annular capsule is attached to the inner side wall of the first steel pipe, placing the second pipe body and the second annular capsule in the second steel pipe, inflating the second annular capsule so that the outer circumferential side of the second annular capsule is attached to the inner side wall of the second steel pipe, and introducing cooling gas into the first pipe body;

[0025] In the step S2, the first steel pipe and the second steel pipe are welded by using a multi-layer and multi-pass welding method; first, a backing layer is welded along the circumference of the first steel pipe and the second steel pipe, so that the gap between the first steel pipe and the second steel pipe is closed, so that the first annular capsule, the second annular capsule, the wall of the first steel pipe, the backing layer and the wall of the second steel pipe enclose a second sealed cavity; and then, layer by layer, welding outwardly.

[0026] As a preferred solution, before welding the base layer, tin foil paper is attached around the outside of the welded end of the first steel pipe, and the side of the tin foil paper away from the first steel pipe is attached to the outside of the second steel pipe; when welding the base layer, the tin foil paper is gradually torn open following the welding gun, so that the cooling gas entering the second sealed cavity escapes from the second sealed cavity at the welding point.

[0027] Compared with the prior art, the beneficial effects of the present application are that:

[0028] The steel pipe welding cooling system of the present application comprises a cooling liquid circulation system and a heat exchange cylinder sleeved on the outside of the steel pipe to be welded, and the heat exchange cylinder is arranged close to the welded end of the steel pipe to be welded; the inner wall of the heat exchange cylinder is provided with a groove arranged around the axis of the steel pipe to be welded, and the outer side wall of the steel pipe to be welded and the groove wall enclose a sealed cavity; the sealed cavity is provided with a liquid inlet and a liquid outlet, the liquid inlet is in communication with the liquid outlet end of the cooling liquid circulation system, and the liquid outlet is in communication with the liquid return end of the cooling liquid circulation system; by introducing cooling liquid into the first sealed cavity, the steel pipe to be welded can be cooled, and the cooling liquid directly contacts the outer side wall of the steel pipe to be welded, ensuring the heat exchange efficiency between the cooling liquid and the steel pipe to be welded and ensuring the cooling effect, thereby reducing the accumulation of heat at the weld, increasing the welding voltage and welding current, shortening the dwell time between welds, reducing the welding construction working hours of the steel pipe, and further shortening the shipbuilding construction period. BRIEF DESCRIPTION OF DRAWINGS

[0029] Figure 1 It is a structural schematic view of the steel pipe welding cooling system of the present application;

[0030] Figure 2 It is a sectional view of the heat exchange cylinder;

[0031] Figure 3 It is Figure 1 It is a sectional view at A-A;

[0032] Figure 4 It is a side view of the heat exchange cylinder;

[0033] Figure 5 It is a schematic view of the first elastic sealing ring installed in the first limiting groove;

[0034] Figure 6 It is a structural schematic view of the gas cooling system;

[0035] In the figure, 1, heat exchange cylinder; 1a, first half cylinder body; 1b, second half cylinder body; 11, groove; 12, first sealing cavity; 13, first flange plate; 131, first annular boss; 14, first elastic sealing ring; 15, cylinder body; 151, first limiting groove; 152, second limiting groove; 16, second elastic sealing ring; 17, second flange plate; 171, second annular boss. DETAILED DESCRIPTION

[0036] The specific embodiments of the present application will be further described in detail below with reference to the accompanying drawings and examples. The following examples are used to illustrate the present application, but are not used to limit the scope of the present application.

[0037] In the description of the present application, it should be understood that the terms "upper", "lower", "left", "right", "top", "bottom", etc. indicate the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application. It should be understood that the terms "first", "second", etc. are used to describe various information in the present application, but these information should not be limited to these terms, and these terms are only used to distinguish the same type of information from each other. For example, the "first" information can also be referred to as "second" information, and similarly, the "second" information can also be referred to as "first" information without departing from the scope of the present application.

[0038] As Figures 1 to 6 shown, the preferred embodiment of the steel pipe welding cooling system of the present application includes a cooling liquid circulating system 6 and a heat exchange cylinder 1 sleeved outside the steel pipe to be welded, the heat exchange cylinder 1 is arranged close to the welding end of the steel pipe to be welded; the inner wall of the heat exchange cylinder 1 is provided with a groove 11 arranged around the axis of the steel pipe to be welded, the outer side wall of the steel pipe to be welded and the groove wall of the groove 11 form a first sealing cavity 12; the first sealing cavity 12 is provided with an inlet and an outlet, the inlet is in communication with the outlet end of the cooling liquid circulating system 6, and the outlet is in communication with the return end of the cooling liquid circulating system 6. By introducing cooling liquid into the first sealing cavity 12, the steel pipe to be welded can be cooled, and the cooling liquid directly contacts the outer side wall of the steel pipe to be welded, ensuring the heat exchange efficiency between the cooling liquid and the steel pipe to be welded and ensuring the cooling effect, thereby reducing the accumulation of heat at the weld, allowing the welding voltage and welding current to be increased and the dwell time between welds to be shortened, reducing the welding construction working hours of the gas pipeline for liquefied gas carrier, and further shortening the shipbuilding construction period. Specifically, the cooling liquid circulating system includes a circulating water pump, a cooler and a liquid storage tank connected in sequence, the outlet of the circulating water pump is connected with the inlet, and the inlet of the cooler is connected with the outlet.

[0039] Wherein, in order to ensure the cooling effect of the cooling liquid, the return liquid end of the cooling liquid circulating system is provided with a thermometer, in the embodiment, the cooling liquid is water, when the return water temperature of the cooling liquid is higher than 80 DEG C, the welding operation is stopped. Further, the steel pipe welding cooling system comprises a controller and a buzzer, the buzzer and the thermometer are electrically connected with the controller, when the temperature of the thermometer is higher than 80 DEG C, the controller sends an electric signal to the buzzer, so that the buzzer buzzes to alarm, so that the operator can know the real-time temperature of the cooling liquid.

[0040] Specifically, in order to ensure the sealing of the first sealed cavity 12, as shown, Figure 2 The heat exchange cylinder 1 comprises a first flange plate 13, a first elastic sealing ring 14, a cylinder body 15, a second elastic sealing ring 16 and a second flange plate 17, the groove 11 is arranged in the cylinder body 15, and the first flange plate 13, the first elastic sealing ring 14, the cylinder body 15, the second elastic sealing ring 16 and the second flange plate 17 are sequentially sleeved outside the steel pipe to be welded; the first flange plate 13 is connected with the cylinder body 15 through a first fastening structure, the first fastening structure drives the first flange plate 13 to move towards the cylinder body 15, so as to extrude the first elastic sealing ring 14, and the inner wall of the first elastic sealing ring 14 is in abutment with the outer side wall of the steel pipe to be welded; the second flange plate 17 is connected with the cylinder body 15 through a second fastening structure, the second fastening structure drives the second flange plate 17 to move towards the cylinder body 15, so as to extrude the second elastic sealing ring 16, and the inner wall of the second elastic sealing ring 16 is in abutment with the outer side wall of the steel pipe to be welded.

[0041] Further, one end of the cylinder body 15 close to the first elastic sealing ring 14 is provided with a first limiting groove 151, the first elastic sealing ring 14 is arranged in the first limiting groove 151, and the other end of the first flange plate 13 opposite to the cylinder body 15 is provided with a first annular boss 131, the first annular boss 131 is inserted into the first limiting groove 151; the first limiting groove 151 limits the deformation space of the first elastic sealing ring 14 after being compressed, so that when the first flange plate 13 extrudes the first elastic sealing ring 14, the inner wall of the first elastic sealing ring 14 is tightly attached to the outer side wall of the steel pipe to be welded.

[0042] One end of the cylinder body 15 close to the second elastic sealing ring 16 is provided with a second limiting groove 152, the second elastic sealing ring 16 is arranged in the second limiting groove 152, and the other end of the second flange plate 17 opposite to the cylinder body 15 is provided with a second annular boss 171, the second annular boss 171 is inserted into the second limiting groove 152.

[0043] In this embodiment, after the welding is completed, the heat exchange cylinder 1 can be moved along the axial direction of the welded steel pipe to be detached from the welded steel pipe; in order to facilitate the disassembly of the heat exchange cylinder 1, in this embodiment, the heat exchange cylinder 1 comprises a first half cylinder body 1a and a second half cylinder body 1b which are detachably connected to form a cylindrical shape, the inner wall of the first half cylinder body 1a is provided with a first groove section, the inner wall of the second half cylinder body 1b is provided with a second groove section, and the first groove section and the second groove section are combined into a groove 11. Specifically, as shown in Figure 3 、 Figure 4 , the first flange plate 13, the cylinder body 15 and the second flange plate 17 all adopt a two-leaf combined structure; in this embodiment, as shown in Figure 5 , the first elastic sealing ring 14 comprises at least two high-temperature-resistant rubber rings 141 arranged in sequence, each high-temperature-resistant rubber ring 141 is a non-closed structure, specifically, each high-temperature-resistant rubber ring 141 is provided with a cut-off port 1411, and in use, each cut-off port 1411 is arranged staggered to ensure the sealing performance, and the cut-off port 1411 facilitates the removal of each high-temperature-resistant rubber ring 141 from the welded steel pipe, so that each high-temperature-resistant rubber ring 141 can be reused; in other embodiments of the present application, the first elastic sealing ring 14 and the second elastic sealing ring 16 can adopt an integral type, and after the welding is completed, the first elastic sealing ring 14 and the second elastic sealing ring 16 can be cut off.

[0044] In this embodiment, the steel pipe to be welded comprises a first steel pipe 21 and a second steel pipe 22, the welded end of the first steel pipe 21 and the welded end of the second steel pipe 22 are arranged in opposite intervals, and the outer side of the first steel pipe 21 and the outer side of the second steel pipe 22 are both sleeved with a heat exchange cylinder 1; the cooling system for steel pipe welding comprises a gas cooling system, the gas cooling system comprises a first pipe body 31 and a second pipe body 32, the first end of the first pipe body 31 is inserted into the lumen of the first steel pipe 21, the outer side of the first end of the first pipe body 31 is sleeved with a first annular capsule 41, the outer peripheral side of the first annular capsule 41 is attached to the inner side wall of the first steel pipe 21, and the second end of the first pipe body 31 is in communication with a cooling gas supply system; the first end of the second pipe body 32 is inserted into the lumen of the second steel pipe 22, the outer side of the first end of the second pipe body 32 is sleeved with a second annular capsule 42, the outer peripheral side of the second annular capsule 42 is attached to the inner side wall of the second steel pipe 22, and the second end of the second pipe body 32 is in communication with an exhaust system. The cooling gas is blown to the surrounding of the weld, which further improves the cooling effect of the steel pipe welding cooling system of the present application on the steel pipe to be welded. Specifically, the first sealing cavities 12 of the two heat exchange cylinders 1 are communicated through the third pipe body 7.

[0045] Specifically, the cooling gas supply system comprises a liquefied argon tank, and the second end of the first pipe body 31 is communicated with the gas outlet of the liquefied argon tank. The temperature of the liquefied argon is reduced after vaporization, which ensures that the argon gas entering the surrounding of the weld has a low temperature, and the argon gas can reduce the oxygen content around the weld to prevent the weld from being oxidized, thereby further improving the welding quality.

[0046] A method for using the above-mentioned cooling system for steel pipe welding, comprising the following steps:

[0047] Step S1, each of the heat exchange cylinders 1 is sleeved on the welding end of the first steel pipe 21 and the welding end of the second steel pipe 22, and the first sealing cavity of each of the heat exchange cylinders 1 is communicated with the cooling liquid circulation system;

[0048] Step S2, welding the welding end of the first steel pipe 21 and the welding end of the second steel pipe 22;

[0049] Step S3, removing each of the heat exchange cylinders 1.

[0050] Specifically, step S1 further comprises:

[0051] The first pipe body 31 and the first annular bag 41 are placed in the first steel pipe 21, the first annular bag 41 is inflated, so that the outer circumferential side of the first annular bag 41 is attached to the inner side wall of the first steel pipe 21; the second pipe body 32 and the second annular bag 42 are placed in the second steel pipe 22, the second annular bag 42 is inflated, so that the outer circumferential side of the second annular bag 42 is attached to the inner side wall of the second steel pipe 22, and the cooling gas is introduced into the first pipe body 31;

[0052] In step S2, the first steel pipe 21 and the second steel pipe 22 are welded by using a multi-layer and multi-pass welding method; first, a backing layer is welded along the circumference of the first steel pipe 21 and the second steel pipe 22, so that the gap between the first steel pipe 21 and the second steel pipe 22 is closed, so that the first annular bag 41, the second annular bag 42, the pipe wall of the first steel pipe 21, the backing layer and the pipe wall of the second steel pipe 22 enclose a second sealing cavity; then, the welding is performed layer by layer outward. After the gap between the first steel pipe 21 and the second steel pipe 22 is closed, argon gas is introduced into the second sealing cavity, which can avoid the outflow of argon gas in the subsequent welding process, and further improve the cooling effect.

[0053] Further, in order to prevent a large amount of argon gas from flowing out during welding of the backing layer, a tin foil paper 5 is attached around the outer side of the welding end of the first steel pipe 21 before welding of the backing layer, and the side of the tin foil paper 5 away from the first steel pipe 21 is attached to the outer side of the second steel pipe 22; during welding of the backing layer, the tin foil paper 5 is gradually torn away following the welding gun, so that the cooling gas introduced into the second sealing cavity 9 flows out of the second sealing cavity at the welding point.

[0054] In summary, the preferred embodiment of the cooling system for steel pipe welding can cool the steel pipe to be welded by introducing the cooling liquid into the first sealing cavity 12, and the cooling liquid directly contacts the outer wall of the steel pipe to be welded, which ensures the heat exchange efficiency between the cooling liquid and the steel pipe to be welded, guarantees the cooling effect, reduces the heat accumulation at the weld, increases the welding voltage and welding current, shortens the dwell time between the welds, reduces the welding construction time of the gas pipeline for liquefied gas carrier, and further shortens the shipbuilding construction period.

[0055] The above only describes the preferred embodiments of the present application, and it should be noted that those skilled in the art can make several improvements and replacements without departing from the technical principles of the present application, and these improvements and replacements should also be considered as the protection scope of the present application.

Claims

1. A cooling system for welding a steel pipe, characterized by, The steel pipe welding cooling system comprises a cooling liquid circulating system (6) and a heat exchange cylinder (1) sleeved outside a steel pipe to be welded, wherein the heat exchange cylinder (1) is arranged close to a welding end of the steel pipe to be welded. An inner wall of the heat exchange cylinder (1) is provided with a groove (11) arranged around an axis of the steel pipe to be welded, and an outer side wall of the steel pipe to be welded and a groove wall of the groove (11) form a first sealed cavity (12); the first sealed cavity (12) is provided with an inlet and an outlet, the inlet is communicated with an outlet end of the cooling liquid circulating system (6), and the outlet is communicated with a return end of the cooling liquid circulating system (6); the heat exchange cylinder (1) comprises a first flange plate (13), a first elastic sealing ring (14), a cylinder body (15), a second elastic sealing ring (16) and a second flange plate (17), the groove (11) is arranged in the cylinder body (15), and the first flange plate (13), the first elastic sealing ring (14), the cylinder body (15), the second elastic sealing ring (16) and the second flange plate (17) are sequentially sleeved outside the steel pipe to be welded. A first fastening structure is connected between the first flange plate (13) and the cylinder body (15), the first fastening structure drives the first flange plate (13) to move towards the cylinder body (15) to extrude the first elastic sealing ring (14), so that an inner wall of the first elastic sealing ring (14) abuts against the outer side wall of the steel pipe to be welded. A second fastening structure is connected between the second flange plate (17) and the cylinder body (15), the second fastening structure drives the second flange plate (17) to move towards the cylinder body (15) to extrude the second elastic sealing ring (16), so that an inner wall of the second elastic sealing ring (16) abuts against the outer side wall of the steel pipe to be welded. The heat exchange cylinder (1) comprises a first half cylinder (1a) and a second half cylinder (1b) which are detachably connected to form a cylinder, an inner wall of the first half cylinder (1a) is provided with a first groove section, an inner wall of the second half cylinder (1b) is provided with a second groove section, and the first groove section and the second groove section are spliced to form the groove (11). The steel pipe to be welded comprises a first steel pipe (21) and a second steel pipe (22), a welding end of the first steel pipe (21) and a welding end of the second steel pipe (22) are oppositely and spacedly arranged, and the first steel pipe (21) and the second steel pipe (22) are both sleeved with the heat exchange cylinder (1). The steel pipe welding cooling system comprises a first pipe body (31) and a second pipe body (32), a first end of the first pipe body (31) is inserted into a pipe cavity of the first steel pipe (21), an outer side of the first end of the first pipe body (31) is sleeved with a first annular capsule (41), an outer circumferential side of the first annular capsule (41) is attached to an inner side wall of the first steel pipe (21), and a second end of the first pipe body (31) is communicated with a cooling gas supply system. The first end of the second pipe body (32) is inserted into the lumen of the second steel pipe (22), the outer side of the first end of the second pipe body (32) is sleeved with a second annular bag (42), the outer peripheral side of the second annular bag (42) is attached to the inner side wall of the second steel pipe (22), and the second end of the second pipe body (32) is communicated with an exhaust system. The first elastic sealing ring (14) comprises at least two high-temperature-resistant rubber rings (141) arranged in sequence.

2. The cooling system for welding steel pipes according to claim 1, characterized by The liquid return end of the cooling liquid circulation system (6) is provided with a thermometer.

3. The cooling system for welding steel pipes according to claim 1, wherein The end of the cylinder body (15) close to the first elastic sealing ring (14) is provided with a first limiting groove (151), the first elastic sealing ring (14) is arranged in the first limiting groove (151), and the end of the first flange plate (13) opposite to the cylinder body (15) is provided with a first annular boss (131), the first annular boss (131) is inserted into the first limiting groove (151). The end of the cylinder body (15) close to the second elastic sealing ring (16) is provided with a second limiting groove (152), the second elastic sealing ring (16) is arranged in the second limiting groove (152), and the end of the second flange plate (17) opposite to the cylinder body (15) is provided with a second annular boss (171), the second annular boss (171) is inserted into the second limiting groove (152).

4. The cooling system for welding steel pipes according to claim 1, wherein The heat exchange cylinder (1) comprises a first half cylinder body (1a) and a second half cylinder body (1b) which are detachably connected to form a cylinder, the inner wall of the first half cylinder body (1a) is provided with a first groove section, the inner wall of the second half cylinder body (1b) is provided with a second groove section, and the first groove section and the second groove section are spliced into the groove (11).

5. The cooling system for welding steel pipes according to claim 1, wherein The cooling gas supply system comprises a liquefied argon tank, and the second end of the first pipe body (31) is communicated with the gas outlet of the liquefied argon tank.

6. A method of using the cooling system for welding a steel pipe according to any one of claims 1 to 5, characterized by, The method comprises the following steps: Step S1, sleeving the heat exchange cylinder (1) on the welded end of the first steel pipe (21) and the welded end of the second steel pipe (22); Step S2, welding the welded end of the first steel pipe (21) and the welded end of the second steel pipe (22); Step S3, removing the heat exchange cylinder (1).

7. The method of using a quench system for welding steel pipe according to claim 6, wherein The step S1 further comprises: placing the first pipe body (31) and the first annular bag (41) in the first steel pipe (21), inflating the first annular bag (41) so that the outer peripheral side of the first annular bag (41) is attached to the inner side wall of the first steel pipe (21), placing the second pipe body (32) and the second annular bag (42) in the second steel pipe (22), inflating the second annular bag (42) so that the outer peripheral side of the second annular bag (42) is attached to the inner side wall of the second steel pipe (22), and introducing cooling gas into the first pipe body (31). In the step S2, the first steel pipe (21) and the second steel pipe (22) are welded by using a multi-layer multi-pass welding method; first, a backing layer is welded along the circumferential direction of the first steel pipe (21) and the second steel pipe (22), so that the gap between the first steel pipe (21) and the second steel pipe (22) is closed, so that the first annular capsule (41), the second annular capsule (42), the wall of the first steel pipe (21), the backing layer and the wall of the second steel pipe (22) form a second sealed cavity; then, the layers are welded outward layer by layer.

8. The method of using a cooling system for welding steel pipe according to claim 7, wherein, Before welding the backing layer, tin foil paper (5) is attached around the outer side of the welding end of the first steel pipe (21), and the side of the tin foil paper (5) away from the first steel pipe (21) is attached to the outer side of the second steel pipe (22); when welding the backing layer, the tin foil paper (5) is gradually torn away following the welding gun, so that the cooling gas entering the second sealed cavity (9) escapes from the second sealed cavity at the welding point.

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