RU2554670C1 - Two-shaft gas-compressor unit for booster compressor stations - Google Patents

Abstract

FIELD: oil and gas industry.

SUBSTANCE: gas-compressor unit includes a gas-turbine engine, a multiplier connected to it, having two power takeoff shafts and two compression stages in the form of a low pressure compressor and a high pressure compressor, which are connected with a process loop and each of which is connected to the corresponding power takeoff shaft.

EFFECT: improving vibration characteristics and efficiency of unit operation, simplifying a process flow diagram and excluding the need for use of additional equipment; providing symmetric load distribution to the multiplier.

3 cl, 1 dwg

Description

The invention relates to the industry of oil and gas engineering, in particular to gas compressor units used at booster compressor stations for compressing hydrocarbon gases for further transportation through main pipelines or for use in gas preparation and processing processes.

At booster compressor stations, two-stage compression with intermediate gas cooling is used to achieve high compression ratios (over 4.0). Existing technological schemes of booster compressor stations suggest the following layout options for gas pumping units with centrifugal compressors:

- two autonomous booster compressor stations of the first and second compression stages with gas compressor units, which include single-stage single-case centrifugal compressors with direct drive from a gas turbine engine;

- a booster compressor station, which includes gas compressor units with two-stage two-case compressors with intermediate cooling, located on one shaft, the drive of which is carried out from the gas turbine engine through an intermediate boost gearbox (multiplier) having one power take-off shaft;

- a booster compressor station, which includes gas compressor units with two-section single-shell centrifugal compressors with intermediate cooling, the drive of which is carried out from a gas turbine engine through an intermediate boost gearbox (multiplier) having one power take-off shaft.

The closest solution to the proposed invention is a block-complete turbocharger installation for the transportation of hydrocarbon gas, consisting of a double-shell centrifugal compressor with the location of the compressor housings low and high pressure on one shaft, a gas turbine drive with a multiplier, a process circuit equipped with shut-off and control valves, as well as sensors of the automated control system of the installation, moreover, the technological circuit has a linear layout, and the compression stages of the double-shell centrifugal compressor are equipped with air-cooling units and separators (see Patent RU No. 2464448, published on October 20, 2012).

The disadvantages of the above schemes and the closest solutions are:

- complex technological scheme;

- a long line of the shaft of a centrifugal compressor;

- the inability to use a high-tech vertical housing connector for the compressor of the first stage of compression;

- low efficiency of the unit, caused by the inability to use compressors of the first and second compression stages with different nominal speeds;

- the complexity of the maintenance during operation and during the overhaul;

- the presence of mutual mechanical and gas-dynamic effects of compressor rotors of the first and second stages of compression;

- technological limitations on linear dimensions and pressure characteristics in the case of single-case compressors;

- the difficulty of unification of gas compressor units of the first and second stages of compression;

- low vibration resistance.

The technical result of the invention is to improve the vibrational characteristics and increase the efficiency of the unit due to the possibility of using compressors of the first and second compression stages with different nominal speeds while eliminating the mutual influence of compressor rotors, simplifying the technological scheme, ensuring a symmetrical load distribution on the multiplier.

The technical result of the invention is achieved due to the fact that the gas compressor unit contains a gas turbine engine, an associated multiplier having two power take-off shafts, and two compression stages in the form of a low-pressure compressor and a high-pressure compressor connected by a technological circuit, each of which is connected to a corresponding shaft power take-off.

In addition, the PTO shafts are parallel to each other.

In addition, each of these compressors has a housing with a vertical connector.

The invention is illustrated in the drawing, which schematically shows a twin-shaft gas compressor unit.

The twin-shaft gas compressor unit for booster compressor stations is a gas turbine installation, which contains a gas turbine engine 1, to which a multiplier 2 (boost reduction gear) is connected, having two power take-off shafts 3 and 4 parallel to each other. The installation also contains a double-shell centrifugal compressor, comprising two stages of compression in the form of a compressor 5 low pressure and compressor 6 high pressure connected by a technological circuit 9. Centrifugal compressor There is an apparatus 7 for intermediate air cooling, located in the technological circuit 9 between two stages of compression. Centrifugal compressors 5 and 6 have housings with a high-tech vertical “barrel” type connector (not shown) and are located on a power frame (not shown) parallel to each other. The low-pressure compressor 5 is connected to the driven shaft 3 of the multiplier 2, and the high-pressure compressor 6 is connected to the driven shaft 4 of the multiplier 2, thus, the compressors 5, 6 have independent drives, each of which has its own speed during operation.

The gas compressor unit also includes a technological shelter 8 with a technological circuit 9 (with engineering support systems), equipped with pipelines, shutoff and control valves, as well as control sensors.

The design of the centrifugal compressor housings provides for the possibility of installing replaceable flowing parts at a higher pressure ratio, which allows the gas compressor unit to operate in a wide range of capacity and inlet pressures.

To transmit torque from the shaft of the power turbine of the driving gas turbine engine 1 to the shafts 3, 4 of the low and high pressure compressors 5, 6, a multiplier 2 with a parallel arrangement of two power take-off shafts 3, 4 is used. A power turbine (output shaft) of the driving gas turbine engine 1 is connected with the drive shaft of the multiplier 2 by means of an elastic "dry" coupling (not shown), which allows to compensate for the inaccuracy of the installation of the connected shafts, as well as thermal displacement due to the elastic elements. The driven shafts 3, 4 of the multiplier 2 are connected through a clutch (not shown) with the shafts of the rotors of low and high pressure compressors 5, 6.

Compressed gas is supplied to the inlet of the low-pressure compressor 5, then after cooling in the intermediate gas cooler 7 to the inlet of the high-pressure compressor 6, after which it is supplied to the discharge pipe.

In the case of using a gas compressor unit in a technological scheme with intermediate low-temperature separation, a low-pressure compressor 5 is used to compress associated petroleum gas, and a high-pressure compressor 6 is used for dry stripped gas.

Thus, due to the above-described embodiment of a gas compressor unit with two power take-off shafts, it is possible to use compressors with different nominal revolutions as stages of low and high pressure; the compressor shaft length is reduced by half; vibration characteristics of both compressors and the entire unit as a whole are improved; symmetrical load distribution on the drive gear of the multiplier is provided due to the presence of two parallel power take-off shafts; mutual influence of rotors of low and high pressure compressors is excluded, especially in the range of emergency conditions; if a low-temperature separation cycle is used as part of a two-stage booster compressor station, it is possible to unify the units of the first and second stages by using a single gas turbine engine to drive a low pressure compressor (first stage) to compress associated petroleum gas and a high pressure compressor (second stage) - for compressing dry stripped gas; Due to the presence of a high-tech housing with a vertical connector, both its maintenance during operation and the overhaul of compressors are greatly simplified.

If it is necessary to achieve high compression ratios, the unit allows the use of single-casing two-section centrifugal compressors with intermediate cooling at both stages of compression.

Claims (3)

1. A gas compressor unit comprising a gas turbine engine, an associated multiplier having two power take-off shafts and two compression stages in the form of a low-pressure compressor and a high-pressure compressor connected by a process circuit, each of which is connected to a corresponding power take-off shaft. 2. The unit according to claim 1, characterized in that the power take-off shafts of the multiplier are parallel to each other. 3. The unit according to claim 1, characterized in that each of these compressors has a housing with a vertical connector.

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