RU2458253C1 - Radial-flow compressor unit - Google Patents

Abstract

FIELD: engines and pumps.

SUBSTANCE: proposed compressor incorporates motor with rotor and stator fitted on shaft running in bearings, and vaned compression assembly. Said assemblies are arranged in tight housing. Note here that motor stator is arranged inside hollow vaned rotor to make compression assembly rotor section with its stator section arranged on tight housing and made up of vanes attached to tight housing.

EFFECT: higher reliability and efficiency, lower operating costs, ease of repair and maintenance.

3 cl, 2 dwg

Description

The invention relates to the field of compressor engineering, mainly to sealed axial and centrifugal compressors with integrated high-speed electric drive without lubrication in the rotor bearings.

A known design of a sealed compressor unit containing a high-speed electric motor with one shaft on magnetic bearings, at each end of which is cantilevered on the wheel. All rotating elements are in one sealed enclosure, located in the gas environment of the technological process (see, for example, Yves Detomb “Use of magnetic bearings in the oil and gas industries” in the collection “New in equipment and technology”, Moscow, “Neftegaz-98” p. 143-148).

The disadvantages of this device include:

- restriction on the degree of increase in pressure in the unit, due to the use of one or two impellers fixed on the consoles of the motor shaft;

- restrictions on the dimensions and weight of the impellers imposed by the critical shaft speed (flexible rotor).

Also known is a centrifugal compressor unit containing an electric motor having a stator and a rotor, at least one compressor containing a driven shaft rotationally driven by the rotor of the electric motor, and a system of wheels with vanes mounted on said driven shaft, the system formed by the engine and compressor, is located in a common housing, while the housing of the unit is formed by connecting the elements of this housing, providing, respectively, engine retention and retention of compression stages of the compressor litter, and these housing elements are connected to each other rigidly and tightly, while the rotor of the engine and the driven shaft of the compressor are interconnected by a flexible connecting element located in the said housing, and the ends of each shaft are held by an end bearing (see patent RU 2333398, published September 10, 2008).

The design used the traditional classical scheme:

- the stator of the electric motor with field windings is located outside the rotor of the electric motor;

- compression modules are placed at the ends of the motor in the axial direction;

- the rotor of the electric motor and the rotor of the compression module constitute the rotor of the compressor unit, rotating on magnetic bearings located in the stator of the electric motor and in the cases of the compression modules.

The disadvantage of this device is that the number of magnetic bearings in the compressor unit increases in proportion to the number of compression modules; the axial dimension of the unit increases; access to (electro) magnetic poles is complicated.

The technical result of the invention is to increase the operational reliability of a sealed compressor unit, reduce operating costs, reduce the amount of work during maintenance and repair, reduce the number of monitored parameters, reduce overall dimensions.

The technical result of the invention is achieved due to the fact that the centrifugal compressor unit contains an electric motor having a stator and a rotor with a shaft mounted on bearings and a compression unit including blades, while the said units are located in a sealed housing, and the stator of the electric motor is installed inside the hollow rotor enclosing it an electric motor made with blades and forming the rotor part of the compression unit, the stator part of which is located on an airtight housing and made in the form of a shovel Mounted on a sealed enclosure.

In addition, the bearings are magnetic or electromagnetic bearings.

In addition, the stator of the electric motor is fixed in the housing by means of struts fixed to the housing.

The invention is illustrated by drawings, where figure 1 shows a centrifugal compressor unit with a radial inlet and a radial outlet of the process gas; figure 2 shows the axial section of the compressor unit with axial input-output.

The centrifugal compressor unit contains a stationary sealed housing 1. Inside the housing 1 are a high-speed electric motor 2 and a compression unit 3. The electric motor 2 has a cooled stator 4 with field windings (Fig. 1, 2), which is rigidly fixed in the housing 1 by means of covers 5 fixed to its ends (Fig. 1). Also, the electric motor 2 has a hollow rotor 6 located on the outside of the stator 4, having a shaft (not shown) in common with the stator 4. Between the stator 4 and the rotor 6 is a set of bearings 7, which are magnetic or electromagnetic bearings on which the rotor 6 rotates.

The compression unit 3 of the compressor unit includes a rotor part formed by the rotor 6 with compressor blades 8 (wheels) located on its outer side, which make up one or several rows, and a stator part, formed by stator parts fixed to the inner side of the housing 1 (including the number of blades) 9 located between the respective blades 8 (wheels) of the rotor part. In this case, the rotor 6 becomes "rigid" in terms of critical rotational speeds.

In a design with an axial inlet-outlet of the process gas (Fig. 2), the stator 4 of the electric motor 2 is fixed in the housing 1 by means of struts 10.

When the electric motor 2 is turned on, the rotor 6 of the electric motor 2 together with the blades 8 (wheels) of the compression unit 3 rotates in electromagnetic bearings 7. The rotor blades 8 (wheels) together with the stator parts 9 compress the process gas.

Thus, the centrifugal compressor unit contains a minimum number of components: one sealed housing 1 with a fixed stator 4 of the electric motor 2; one rotor 6, combining the functions of a rotor of an electric motor 2 and a rotor of a multi-stage compressor; one set of (electro) magnetic bearings 7 located between the stator 4 and rotor 6 of the electric motor 2. Reducing the number of components of the unit is one of the ways to increase its operational reliability and reduce operating costs. The axial dimension of the unit is reduced. This centrifugal compressor unit can be located directly in the process gas pipeline.

Since the housing 1 is sealed, when the gas is compressed in the compressor unit, leakages of the compressible gas into the environment are excluded, the component composition of the gas is kept constant. In this case, the compressor unit can be used to work in other environments, in particular under water.

Claims (3)

1. A centrifugal compressor unit comprising an electric motor having a stator and a rotor with a shaft mounted on bearings and a compression unit including blades, said nodes being located in a sealed housing, characterized in that the stator of the electric motor is installed inside the hollow rotor of the electric motor enclosing it, made with blades and forming the rotor part of the compression unit, the stator part of which is located on a sealed housing and made in the form of blades mounted on a sealed housing. 2. The assembly according to claim 1, characterized in that the bearings are magnetic or electromagnetic bearings. 3. The assembly according to claim 1, characterized in that the stator of the electric motor is fixed in the housing by means of racks mounted on the housing.

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