CN101865348B

CN101865348B - Freeze temporary blocking method and device for large-diameter gas pipeline

Info

Publication number: CN101865348B
Application number: CN201010186534XA
Authority: CN
Inventors: 梁政; 兰洪强; 李莲明; 邓雄; 赵广慧; 张梁; 蒋发光
Original assignee: Southwest Petroleum University
Current assignee: Southwest Petroleum University
Priority date: 2010-05-22
Filing date: 2010-05-22
Publication date: 2012-01-18
Anticipated expiration: 2030-05-22
Also published as: CN101865348A

Abstract

The invention relates to a freeze temporary blocking method and a device for a large-diameter gas pipeline, which are applied in the pipeline after spark-free cutting of natural gas pipeline and prior to butt welding of two pipelines. The method can reduce the technical requirements for inert gas replacement prior to welding, and realize the rapid freeze temporary blocking to ensure that the welding position is free from oil and gas. In the technical scheme, the method comprises the following steps: placing pre-frozen cores into two ends of a cut-off pipeline; fixing a bag filled with a freezing medium on the corresponding outer wall of the pipeline, wrapping an insulation jacket, and fixing with a winding belt; pouring water-consolidating emulsifier into the hopper of a screw conveyor, shaking the handle to inject the water-consolidating emulsifier into a gap between the frozen core and the pipeline wall, and completely filling the gap; fixing the freezing medium onto the insulation layer, make an insulation push plate cling to the frozen core with a push rod, and taking out the push rod and the insulation push plate after freezing and consolidation, thereby completing the welding. The invention has the advantages of simple operation, short operating period, low operating cost and good safety and reliability, and is particularly suitable for the field construction of the large-diameter gas pipeline.

Description

A kind of large-diameter gas pipeline freeze temporary blocking method and equipment

Technical field

The present invention relates to a kind of large-diameter gas pipeline freeze temporary blocking method and equipment in the pipeline before the two segment pipe butt welding after with the cutting of natural gas pipeline no-spark that is used for.

Technical background

In the natural gas pipeline actual moving process; Owing to receive the influence of the factors such as change of burn into wearing and tearing, gas transmission route; Therefore just have the repairing of natural gas pipeline, the generation of actual engineering problem such as relocate; Relate to the coal Gas for safety Ignition of gas pipeline, problems such as oil gas isolation.

Present stage, the oil gas isolation technology for the gas pipeline of big caliber had balloon occluder, the shutoff of pipeline disc type, butter wall shutoff etc.

In the actual operating process of getting angry of gas pipeline of big caliber, common way is that the main valve of gas pipeline is turned off, and utilizes inert medium (like nitrogen, water vapour, carbon dioxide) to carry out for a long time, grow apart from pipeline purging; By the time inflammable substance (comprising condensate, rock gas) cuts pipeline in the pneumatic tube when concentration is less than explosion limit; If machine pluggings such as employing balloon occluder are put into equipment such as machine plugging device or leather bag plugging device then apart from the perforate on tube wall of otch one distance from perforate, carry out weld job then, construction finishes the back and takes out plugging device, and the repair welding leather bag is put into the hole again.If adopt sealing agent or butter wall then they to be put into the temporary transient oil gas of isolating of pipeline, detect the content of inflammable gas in the welding process, then stop weldering, displacement if hydrocarbon content reaches explosion limit, up to standard after thread weldering again, so repeatedly.These plugging technology complicated operations, can not pressure-bearing or bearing capacity low, have can pressure-bearing but can not avoid the later stage gas transmission being caused potential safety hazard in the perforate of pipeline wall, can not satisfy the requirement that site safety is accomplished construction fast.

Summary of the invention

The objective of the invention is to: in order to reduce the technical requirements of inert gas replacement in the welding preceding pipeline, guarantee that the welding part does not have oil gas, guarantees weld job safety, the spy provides a kind of large-diameter gas pipeline freeze temporary blocking method and equipment.

For achieving the above object; The technical problem that the present invention solves adopts following technological scheme: a kind of large-diameter gas pipeline freeze temporary blocking method; It is characterized in that: calculate the distance L (100mm-600mm) of large-diameter gas pipeline earlier apart from the welding heat affected zone of otch; In the pipeline that cuts off pipe ends, put into place to the core that freezes that freezes in advance earlier, freeze core by solid water emulsifier freezing processing in mould apart from conduits cut L; Again refrigerant dry ice is divided in the pouch, and is fixed on,, insulation jacket is fixed on the pipeline outer wall with take-up strap in pipeline outer wall parcel insulation jacket corresponding to the pipeline outer wall that freezes the core position; The solid water emulsifier is poured in the hopper of helix transporting device, shaken the handle of helix transporting device, the thrust of utilizing helix transporting device to produce is injected into the solid water emulsifier in the slit of freezing between core and the tube wall, with the slit and fill up; Again in the outer end of freezing core, be fixed on refrigerant on the thermal insulation layer of insulation push pedal, push rod is connected in the push pedal, with push rod whole insulation push pedal and freeze the applying of core front-end face; Solid water emulsifier in being injected into the slit of freezing between core and the pipeline and pipeline wall and freeze wicking surface and freeze when firm take out push rod and insulation push pedal, and can implement welding operation this moment.

Welding procedure is taken off insulation jacket and take-up strap and refrigerant packing pouch after accomplishing, and twine gas pipeline freezing position with heat tape winter, makes the solid water emulsifier recover original state, discharges with rock gas when treating gas pipeline recovery gas transmission.

The related insulation jacket of this method is to be fixed on the leather fabric with certain toughness with aluminum silicate insulation material to form, and the thermal insulating material edge is than the wide 20-40mm of leather fabric, so that compress when twining.The solid water emulsifier is by French chalk, latex powder, and water, organic phenolic aldehyde of making crosslinking agent is made in proportion.

The employed equipment of large-diameter gas pipeline freeze temporary blocking method; By manual helix transporting device, be incubated push pedal, freeze cores and form; Its structure characteristic is: manually helix transporting device has one to have the bearing that becomes 30 °-45 ° tilt angle with Vertical direction, on bearing, places worm conveyor; Hopper is installed above worm conveyor, and front end connects delivery hose, and bearing and handle are installed in the top; The diameter of insulation push pedal is formed with the push pedal of gas pipeline inwall Spielpassung and bonding superincumbent polyurethane foam insulation layer, and push pedal is connected with nut with the push rod that has scale; Freeze cores and connected and composed with the bolt symmetry by the two and half dumbbell shape shells that steel plate rolls, an end is equipped with capping, and the other end top is equipped with the injection channel of injecting the solid water emulsifier.

The present invention and existing technology relatively have following beneficial effect: avoided on large-diameter gas pipeline the perforate to cause stress to concentrate, having improved the Security that gas transmission is recovered in the construction back.Bearing capacity is high, does not need long-time, long distance displacement pipeline purging, saves the engineering time, reduces operating cost, improves the Security of operation.Do not influence normal gas transmission after the de-plugging of solid water emulsifier, need not adopt additive method to get rid of, be applicable to the site operation of large-diameter gas pipeline.

Description of drawings

Fig. 1 is the equipment assembling schematic representation of large-diameter gas pipeline freeze temporary blocking method of the present invention.

Fig. 2 is temporary blocking method thermal insulating material 3 of the present invention and take-up strap 2 structural representations.

Fig. 3 is the insulation of equipment push pedal assembling schematic representation of temporary blocking method of the present invention.

Fig. 4 freezes the cores structural representation for the equipment of temporary blocking method of the present invention.

Among the figure: 1, pipeline 2, take-up strap 3, insulation jacket 4, pouch 5, freeze core 6, refrigerant 7, thermal insulation layer 8, push pedal 9, bearing 10, hopper 11, worm conveyor 12, handle 13, delivery hose 14, bearing 15, leather fabric 16, push rod 17, half dumbbell shape shell 18, bolt 19, injection channel 20, capping 21, nut

Embodiment

Below in conjunction with accompanying drawing and mode of execution the present invention is described further.

According to shown in Figure 1; Freezing core 5 to the dumbbell shaped that freezes in advance puts into apart from pipeline 1 otch L place; Refrigerant 6 is divided in the pouch 4, is fixed on pouch 4 corresponding to pipeline 1 outer wall that freezes core 5 positions, again with take-up strap 2 fixedly insulation jacket 3 in refrigerant 6 outsides; The solid water emulsifier is poured in the hopper 10 of manually operated type helix transporting device, with delivery hose 13 the solid water emulsifier is imported to injection channel 19, the slit that will freeze core 5 and inner-walls of duct 1 fills up; Be fixed on refrigerant 6 on the thermal insulation layer 7 of insulation push pedal, push rod 16 be connected in the push pedal 8, with push rod 16 with whole insulation push pedal with freeze core front-end face applying.For the natural gas pipeline 1 of Φ=700m, insulation jacket 3 and take-up strap 2 winding pipelines 1 length 1000mm;

The thermal insulation layer 7 of insulation push pedal is 696mm with the diameter of push pedal 8, and the insulation push pedal is connected by nut 21 with push rod 16; Welding heat affected zone L=400mm.Manually the tilt angle of helix transporting device bearing 14 is 30 °-45 °, and worm conveyor 11 is installed on bearing 14; Above dress worm conveyor 11, hopper 10 is installed, front end connects delivery hose 13, and bearing 9 and handle 12 are installed in the top.

According to shown in Figure 3, the insulation push pedal is made up of push pedal 8 and bonding superincumbent polyurethane foam insulation layer 7, and push pedal 8 is connected with the push rod that has scale 16 usefulness nuts 21.

According to shown in Figure 4, freeze cores by the two and half dumbbell shape shells 17 that steel plate rolls, connect and compose with bolt 18 symmetries, an end is equipped with capping 20, and the other end top is equipped with the injection channel 19 of injecting the solid water emulsifier.

Natural gas pipeline for Φ=700m; After 1-2 hour, solid water emulsifier and pipeline wall and freeze wicking surface and freeze firmly bear the pipe internal pressure this moment at 0.5-1.0MPa; Effectively block the gas stream in the pipeline; Avoid long distance, replace operation for a long time, getting angry band oil gas becomes no oil gas and gets angry, and makes that pipeline welding is quick, safety, low cost carries out.

Claims

1. large-diameter gas pipeline freeze temporary blocking method; It is characterized in that: calculate the distance L of large-diameter gas pipeline earlier apart from the welding heat affected zone of otch; Freeze core (5) to the dumbbell shaped that freezes in advance and put into, freeze core (5) by solid water emulsifier freezing processing in freezing cores apart from pipeline (1) otch L place; Again refrigerant (6) dry ice is divided in the pouch (4), and is fixed on,, insulation jacket (3) is fixed on pipeline (1) outer wall with take-up strap (2) in pipeline (1) outer wall parcel insulation jacket (3) corresponding to pipeline (1) outer wall that freezes core (5) position; The solid water emulsifier is poured in the hopper (10) of manually operated type helix transporting device, shaken the handle (12) of helix transporting device, the solid water emulsifier is injected in the slit of freezing between core (5) and the pipeline (1) through flow in pipes (19), the slit is filled up; Again in the outer end of freezing core (5), be fixed on refrigerant (6) on the thermal insulation layer (7) of insulation push pedal, push rod (16) is connected in the push pedal (8), with push rod (16) whole insulation push pedal with freeze the applying of core (5) front-end face; Solid water emulsifier in being injected into the slit of freezing between core (5) and the pipeline (1) and pipeline (1) wall and freeze core (5) when shallow freezing is firm take out push rod (16) and insulation push pedal, and can implement welding operation this moment.

2. equipment that freeze temporary blocking method as claimed in claim 1 uses; By manual helix transporting device, be incubated push pedal, freeze cores and form, it is characterized in that: manually helix transporting device has one to have the bearing (14) that becomes 30 °-45 ° tilt angle with Vertical direction and go up and place worm conveyor (11); Hopper (10) is installed in top at worm conveyor (11), and front end connects delivery hose (13), and bearing (9) and handle (12) are installed in the top; The diameter of insulation push pedal is formed with the push pedal (8) of gas pipeline (1) inwall Spielpassung and bonding superincumbent polyurethane foam insulation layer (7), and push pedal (8) is connected with nut (21) with the push rod that has scale (16); Freeze cores and connected and composed with bolt (18) symmetry by the two and half dumbbell shape shells (17) that steel plate rolls, an end is equipped with capping (20), and the other end top is equipped with the injection channel (19) of injecting the solid water emulsifier.