RU2771912C1 - Two-shaft gas compressor unit for booster compressor stations - Google Patents

Abstract

FIELD: mechanical engineering.

SUBSTANCE: invention relates to gas compressor units used at booster compressor stations for compressing hydrocarbon gases. The gas compressor unit contains a gas turbine engine 1, a multiplier 2 connected to it, having two power take-off shafts, and two compression stages in the form of a high-pressure compressor 3 and a low-pressure compressor 4 connected by a technological circuit, each of which is connected to the corresponding power take-off shaft. The gears are replaceable, while the power take-off shaft for one of the compressors is connected to the motor shaft 1 through an intermediate gear 8 that changes the rotation frequency of this shaft, and the bearing support of the intermediate gear 8 is designed to provide the required axial distances between the intermediate gear 8 and the associated gears 6, 7, which it is achieved either by providing a bearing with a sliding working surface offset relative to its outer diameter, or by performing an intermediate gear bearing housing with an offset boring axis.

EFFECT: providing the possibility of changing the rotation speed of the rotors of the compression stages of the two-shaft gas compressor unit regardless of each other.

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Description

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

The closest solution to the proposed invention is a compressor unit containing a gas turbine engine (GTE), an associated multiplier (step-up gearbox), having two power take-off shafts, and two compression stages in the form of a low-pressure compressor (LPC) and a high-pressure compressor connected by a technological circuit pressure (CVD), each of which is connected to the corresponding power take-off shaft. (see Patent RU No. 2554670, published on 06/27/2015).

The disadvantages of the above scheme are the inability to change the speed control range (gear ratio) for one of the power take-off branches, as well as the presence of the mutual influence of the gear ratio between the two power take-off shafts.

With fixed center distances in the gear housing, replacing a gear pair to change the gear ratio on one of the branches inevitably leads to a change by an inversely proportional gear ratio for the gear pair of the other branch. Due to this feature, to change the gear ratio of one of the branches, it is necessary to replace the entire multiplier assembly with the body.

A drive unit with two output shafts is known in which the bearing assemblies of the gear stages, output shafts and idle gear are located on the side walls along a broken line (see Patent KZ U 1340 published on 10/15/2015).

This installation cannot be used to drive two parallel LPC and HPC due to the small center distance between the parallel output shafts. In addition, this unit has overestimated axial transmission dimensions due to the use of a drive gear with an increased width for power take-off in different planes.

At the same time, for compressor equipment used in fields with heterogeneous formation gas compositions or fields with different production conditions during its operation, the possibility of changing its performance is important.

The task to be solved by the claimed invention is to increase the efficiency of a two-shaft gas compressor unit by providing the possibility of changing the rotational speed of the rotors of its compression stages independently of each other.

The technical result is achieved by the fact that in a two-shaft gas compressor unit containing a gas turbine engine, a multiplier with two power take-off shafts connected to the gas turbine engine shaft through gears, 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 the corresponding power take-off shaft, the gears are interchangeable, while the power take-off shaft for one of the compressors is connected to the GTE shaft through an intermediate gear wheel that changes the rotational speed of this shaft, and the bearing support of the intermediate gear wheel is configured to provide the required center distances between the idler and its associated gears. The latter is achieved by performing in the bearing support of the intermediate gear either a bearing with a working sliding surface offset relative to its outer diameter, or an intermediate gear bearing housing with an offset bore axis.

Making the gears replaceable, connecting one of the power take-off shafts to the GTE shaft through an intermediate gear that changes the gear ratio of this gear and making the intermediate gear bearing with the possibility of providing the center distance of the gears corresponding to the given gear ratio implements the possibility of installing replaceable gear pairs in the multiplier , which makes it possible to ensure highly efficient operation of the gas compressor unit in various operating modes.

The design of LPC and HPC housings provides for the possibility of installing replaceable flow parts for a higher pressure ratio, which makes it possible to ensure the operation of the gas compressor unit in a wide range of productivity and inlet pressures.

The invention is illustrated graphically, where:

- in Fig. 1 shows a kinematic diagram of the compressor unit used for the initial operating conditions of the facility.

- in Fig. 2 shows the kinematic diagram of the compressor unit after the upgrade of the multiplier by replacing the gear pair, which provides a corresponding change in the speed of LPC and HPC (in most cases, an increase in the number of revolutions is required).

- fig. 3 shows a diagram of changing the center distances by the value h, which determine the position of the intermediate gear shaft, by using a bearing with an eccentric bore;

- Fig. 4 shows a diagram of changing the center distances by the value h, which determine the position of the intermediate gear shaft, by changing the bearing housing.

A two-shaft gas compressor unit for booster compressor stations contains a gas turbine engine 1, to which a multiplier 2 is connected, having two parallel power take-off shafts for a high pressure compressor 3 (HPC) and a low pressure compressor 4 (LPC), connected to the shaft of the gas turbine engine 1 through gear wheels 5, 6, 7, 8.

The choice of individual rotation speed of LPC 4 and HPC3, the calculation of gears that transmit torque from the gas turbine engine to the corresponding power take-off shafts, is performed according to the following scheme.

The gear ratio from the gear wheel 7 to the gear wheel 5 to ensure the nominal speed of the LPC 4 is calculated at a fixed center distance A1. The gear ratio from the gear wheel 7 to the gear wheel 6 is determined based on the required speed of HPC 3. The center distance A - is selected constructively based on the technological possibility of servicing the equipment. In this case, to transmit torque to HPC 3, an intermediate gear wheel 8 is used, the spatial position of which is determined by the center distances A2 and A3.

If it is necessary to change the gear ratio between the shaft of the gas turbine engine 1 and the shafts of the LPC 4 and HPC 3, gears 5, 6, 7, 8 are replaced with gears 9, 10, 11, 12 (Fig. 2). First, it is necessary to determine the number of teeth of the gear wheels 9 and 11, based on the fixed center distance A1, the diameter of the gear wheel 10 and the required speed of HPC 3. After that, the dimensions of the intermediate wheel 12 and the center distances A12 and A13 (Fig. 3) are determined, which in comparison with nominal distances A2 and A3 must be changed to eliminate the mutual influence of the gear ratio between the two power take-off shafts.

To change the center distances, the design of the gear train (Fig. 3) with bearings 13 of the intermediate wheel 12 with an offset working sliding surface relative to the outer diameter of the bearing 13 (an insert with an eccentric bore) can be used. The eccentricity of the boring is calculated in such a way that when the bearing is rotated 180 degrees, the axis of the working surface is displaced by a distance h, which allows you to install a replaceable gear pair with a different gear ratio. In this case, A3-A13=A12-A2=h

Center distances can also be changed through the use of an intermediate wheel bearing 12 with a replaceable housing 14 (Fig. 4). When replacing the gear pair, the bearing housing 14 is replaced, in which the boring axis is shifted by a distance h.

Thus, thanks to the above-described design of the gas compressor unit with a multiplier with two power take-off shafts, with a parallel scheme for using LPC and HPP, it is possible to individually select the rotor speed of each of the compression stages, which makes it possible to provide optimal operating modes for the unit for fields with heterogeneous formation gas compositions and fields with different production conditions during the operation time.

Claims (3)

1. A two-shaft gas compressor unit for booster compressor stations, containing a gas turbine engine, a multiplier having two power take-off shafts connected to the gas turbine engine shaft through gears, 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 the corresponding power take-off shaft, characterized in that the gears are made interchangeable, while the power take-off shaft for one of the compressors is connected to the shaft of the gas turbine engine through an intermediate gear wheel that changes the rotational speed of this shaft, and the bearing support of the intermediate gear wheel is made with the possibility of providing the required center distances between the intermediate wheel and the gears associated with it. 2. A two-shaft gas compressor unit according to claim 1, characterized in that the bearing in the bearing support of the intermediate gear wheel is made with a working sliding surface offset relative to its outer diameter. 3. Two-shaft gas compressor unit according to claim 1, characterized in that the bearing housing in the bearing support of the intermediate gear wheel is made with an offset boring axis.

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