RU2135885C1 - Method and device for pumping gas from disconnected section of pipe line to operating gas line - Google Patents

Abstract

FIELD: gas industry; transportation of gas via multi-line system. SUBSTANCE: pumping gas out of disconnected section of gas line to operating gas line may be effected only during operation of compressor shops of gas compressor station for any adjacent gas line. To this end, gas transfer units of compressor shops are connected in series to increase total degree of rising of pressure; additional cock is fitted in line of inter-shop strip to connect inter-shop inlet strip with outlet collectors of gas air cooling apparatus of adjacent shops. EFFECT: enhanced efficiency. 3 cl, 3 dwg

Description

 The invention relates to the transportation of gas through gas pipelines. The gas transport system includes gas compressor stations (GCS) with compressor shops (CC), in which gas pumping units (GPU) are installed to compress the transported gas and the linear part (LF) of gas pipelines 100 or more kilometers long between gas compressor stations separated by several valves linear sections (LU) with a length of 20 or more kilometers, while parallel sections of gas pipelines are connected by jumpers with shutoff valves for possible shutdown options Nia separate linear portion of the pipeline out of service if required production scheduled preventive maintenance and repair operations, and disconnected linear section of the pipeline is necessary to release the gas.

 Currently, there is a method of freeing gas from a selected linear section of a gas pipeline by venting it into the atmosphere through candles, which is economically disadvantageous and causing environmental harm to the environment (M. M. Volkov and others. "Gas industry worker Handbook", ed. 2, Nedra, 1989).

 From the technical literature it is known about laying a gas pipeline - looping (of a smaller diameter) along the route of the main gas pipeline to bypass gas into it from a section of the gas pipeline that is being repaired, requiring the release of this disconnected section of the gas pipeline from gas. Gas transferred to the gas pipeline - looping is accumulated and it is supposed to be used for fuel gas from compressor shops and other consumers (consumers of ryegas). In modern gas turbine installations, the fuel gas pressure is 20-30 kgf / cm2, therefore it is practically impossible to use bypass gas from the disconnected section to the gas pipeline — looping, this gas can be used through gas distribution stations to gas distribution consumers, as they operate at lower pressures. To implement this technical solution, it will be necessary to lay, although of a smaller diameter, but an additional pipeline along the route of the main gas pipeline and connect it with jumpers with stop valves with each linear section of the main gas pipeline. This project, apparently due to the large economic costs of its implementation, especially in the conditions of existing and operating gas transmission systems, has not been applied. (NTO - “Using the accumulating capacity of gas pipelines along their entire length”, Series “Transport and Underground Gas Storage”, issue 3 for 1988 of VNIIEGazprom, pp. 2, 35, 36).

 The technical task of the invention is to preserve in the gas pipeline a significant part of the natural gas released into the atmosphere by pumping it to another gas pipeline.

 This is achieved by the fact that in the method of pumping natural gas from a disconnected section of a gas pipeline into an operating gas pipeline of a multi-line system, if necessary, scheduled and preventive maintenance and repair work is carried out, including redistribution of gas flows and change of operating modes of gas pumping units of compressor shops of gas compressor stations, gas from the outlet of the compressor shop compressing the gas pipeline with the section off, they are fed to the input of other compressor workshops connected in series with it. At the same time, the overall degree of pressure increase of successively operating compressor shops is increased.

 To implement the method of pumping gas from a disconnected section of the gas pipeline into an existing gas pipeline, a device is needed that allows the compressor shops to work sequentially at the gas compressor station to any adjacent gas pipeline (string). To do this, the compressor shop, the compression gas pipeline with the disconnected section, is connected in series with other compressor shops in such a way that the output of the specified compressor shop is connected to the inputs of other compressor shops, and on the line of the inter-shop jumper connecting the inputs of adjacent compressor shops, an additional one is installed in series with the taps installed on them a crane, and a jumper with cranes is inserted between the series-installed cranes, connecting the input shop-floor jumper with the outputs of the devices zdushnogo cooling gas (ABO) neighboring shops.

 The method and device are illustrated by drawings, where in FIG. 1 shows a linear section of gas pipelines; in FIG. 2 - gas compressor station; in FIG. 3 - main gas pipeline and gas compressor station.

 Further in the text of the description the following terms, abbreviation and conventions are adopted: LC - linear crane; LC 470 km - a linear crane indicating the kilometer of the gas pipeline, JUICE - the northern security crane KTs (inlet); YuOK - KTs southern security crane (output), (valve N 20 - a valve for transporting gas bypassing the CC; crane N 1 - the inlet valve of the gas compressor unit; crane No. 2 - the outlet valve of the gas compressor unit; crane No. 6 - the bypass valve of the gas compressor unit; - crane No. 29 - ABO gas bypass valve; N 36 valve - KTs bypass valve; N 36p valve - Bypass valve crane N 36; N 36D valve - throttle valve; N 7 valve; N 8 crane - KC inlet and outlet valve, respectively; KC valve N 71 - the inter-workshop jumper crane between the KC input circuits; the N 81 crane - the inter-shop jumper crane between the KC output circuits; the N 70 crane - the purification device receiving chamber crane; the N 80 crane - the chamber crane start the treatment device.

 The method is as follows.

 On the line of the inter-shop jumper connecting the input circuits of the neighboring compressor shops in series to the cranes N 71 installed on them, FIG. 2, additional cranes N 71A are required; FIG. 2, and between the series-installed cranes, insert a jumper with cranes N 81A, N 32A, FIG. 2 connecting the output collectors of the ABO gas, adjacent shops with the input inter-shop jumper. At those gas pumping stations where there are no inter-shop jumpers, it is necessary to perform them according to the proposed scheme of FIG. 2.

 In order to pump gas from a linear section of a gas pipeline that is being repaired, it is necessary to perform the following switching of valves, for example 3, disconnect the linear section of the gas pipeline “A” from 470 km to 495 km, while opening the northern lintels on linear cranes 470 km between the gas pipelines “AB” and “B-V”, close the southern jumper on the northern security cranes 525 km between with А-B pipelines, close the 470 km linear valve of the A gas pipeline, the compressor department KTs-1 pump gas from the formed capacity of the A gas pipeline from the 470 km linear valve to the KTs-1 inlet, as the inlet and outlet pressure decreases KC-1 of FIG. 2 open the crane N 36p, then the crane N 36, the crane N 36D is open FIG. 2, the check valve at the output of KC-1 of FIG. 2, at the same time, the GPU load on KC-1 is reduced, the shop operates on a “ring”, that is, the compressed gas from the KC-1 outlet is fed to its input, then taps N 81A, N 71A are opened, FIG. 2, while the position of the cranes N 71, N 81 is “closed” between KTs-1 and KTs-2 of FIG. 2, if cranes N 71, N 71A, between KTs-2 and KTs-3 of FIG. 2 were closed, then they are opened, valves No. 36, No. 36p of FIG. 2. Thus, sequential operation of gas pumping units, compressor shops will be carried out, that is, from the output of KC-1, the compressed gas is supplied to the inlet of the GPU KC-2 and KTs-3.

The sequential operation of the gas compressor station of the compressor shops allows to increase the overall degree of pressure increase of the gas compressor station, limited for gas pipelines of internal nominal diameter d _у = 1400 mm, with an outlet pressure P _out = 75 kgf / cm ² , as a result, it is possible to reduce the pressure at the inlet of the gas compressor station КЦ-1 for gas evacuation from the disconnected section of the gas pipeline and, accordingly, the pressure and volume of gas in the disconnected section of the gas pipeline will significantly decrease.

где E - степень повышения давления газа одного компрессорного цеха; P_вых - выходное давление КУ, ата; P_вх - входное давление КЦ, ата;
При последовательной работе КЦ степени повышения давления умножаются, то есть E = 1,5 • 1,5 = 2,25, следовательно давление на входе КЦ откачивающего газ из отключенного участка понизится до
P_вх = P_вых/E - 76/2,25 = 34 ата.

where E is the degree of increase in gas pressure of one compressor shop; P _o - output pressure KU, ata; P _I - input pressure CC, ata;
During the successive operation of the CC, the degree of pressure increase is multiplied, that is, E = 1.5 • 1.5 = 2.25, therefore the pressure at the inlet of the CC pumping gas from the disconnected section will decrease to
P _in = P _out / E - 76 / 2.25 = 34 at.

 Further gas pumping is limited by the technical capabilities of gas pumping units. Section A of the gas pipeline “A” 470 km - 495 km is finally shut off, that is, they close the linear crane 495 km of the gas pipeline “A”, open the southern jumpers on linear cranes 495 km between the gas pipelines “AB” and “B-V”, open the southern bridge on the SOK 525 km between the AB gas pipelines, valves N 81A, N 71A are closed at the gas compressor station, between KTs-1 and KTs-2, taps N 71, N 71A are closed, between KTs-2 and KTs-3, they are being restored GPU operation of the gas compressor station, open candle taps for 470 km and 495 km, the remaining gas in the disconnected section is vented to the atmosphere.

Claims (2)

 1. A method of pumping natural gas from a disconnected section of a gas pipeline into an existing gas pipeline of a multi-strand system, including redistributing gas flows and changing operating modes of gas pumping units of compressor shops of gas compressor stations, if necessary, carrying out scheduled maintenance and repair work, characterized in that the gas from the outlet of the compressor shop is compressing a gas pipeline with a disconnected section is fed to the entrance of other compressor shops connected in series with it, while increasing vayut overall pressure ratio of compressor stations operating in series.  2. A device for pumping natural gas from a disconnected section of a gas pipeline into an existing gas pipeline, including a multi-shop compressor station of a multi-strand gas pipeline with gas pumping units of compressor shops connected to the inlets and outlets of the corresponding gas pipeline, gas purification and cooling units, shutoff valves and jumpers between the shops, characterized the fact that the compressor shop compressing the gas pipeline with the disconnected section is connected in series with other compressor shops Thus, the output of the specified compressor shop is connected to the inputs of other compressor shops, and on the line of the inter-shop jumper connecting the inputs of neighboring compressor shops, an additional crane is installed in series with the cranes installed on them, and a jumper with cranes is connected between the series-installed cranes connecting the inlet shop a jumper with the exits of gas cooling apparatuses of neighboring workshops.

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