EP1069313B1 - Turbo compressor - Google Patents

Description

The invention relates to a turbocompressor according to the Preamble of claim 1.

It is known a turbo compressor, which one Includes radial turbocompressor and an electric motor, wherein each of these units is arranged in a separate housing, and the shaft of the electric motor via a flexible shaft part the shaft of the radial turbocompressor is coupled.

A disadvantage of this known turbocompressor is the fact that this is made relatively large that a plurality of seals and bearings are required and that the Cost of the turbo compressor are therefore relatively high.

The document DE 37 29 486 C1 discloses a Turbo compressor, which two two-stage radial turbocompressor As well as an electric motor, these being connected to a rigid Wave are coupled, which in three places with magnetic Radial bearings is stored. In a particular embodiment a partial flow of the compressed and recooled gas is the Rotor of the electric motor and the radial bearings for cooling fed. The known turbocompressor has the disadvantage that the assembly is very elaborate and difficult that this arrangement for a maximum of two stages Radial turbocompressor is suitable and that the turbo compressor has relatively high dissipation losses.

From document US-A-4 523 896 is a generic Turbo compressor known in which the interiors of both sides of the Electric motors are each provided with a discharge. The Both discharges are with a to the intake manifold of the Compressor leading pipe connected. In the tube is a Injector arranged, which is a partial flow of the compressed gas is supplied. This gas is throttled in the injector to to create a lower pressure. In the tube is characterized Maintain low pressure circuit, which consists in that the medium from the interior of the electric motor for Intake manifold is returned. Through this cycle should the interior of the electric motor is placed under reduced pressure become.

The invention is based on the object for a generic turbocompressor effective cooling of the Electric motor and the electromagnetic bearing provide.

The task is in a generic turbocompressor According to the invention by the characterizing features of Claim 1 solved. Advantageous embodiments of the invention are the subject matter of claims 2 to 8.

In the invention, a portion of the compressed fluid or Process gas for longitudinal gas cooling of the engine and the Radial bearing used. Through the cooling gas circuit in conjunction with the outlet opening, the engine cooling on a low pressure level, thereby reducing the dissipation losses be reduced in the engine. This is when using a common, hermetically sealed pressure housing advantageous. As an electric motor is preferably one for suction or Standstill pressure designed engine used. In another advantageous embodiment, the electric motor has a separate, separate from the radial turbo compressor cooling circuit on.

Fig. 1

eine schematische Anordnung eines bekannten Turboverdichters;

Fig. 2

einen Längsschnitt eines Turboverdichters mit einem Elektromotor sowie einem Radialturboverdichter,

Fig. 3

einen Längsschnitt eines Turboverdichters mit beidseitig angeordneten Radialturboverdichtern,

Fig. 4

einen weiteren Längsschnitt eines Turboverdichters mit beidseitig angeordneten Radialturboverdichtern,

Fig. 5

einen Längsschnitt durch die Verbindungsstelle zweier Teilgehäuse,

Fig. 6

einen Längsschnitt eines schematisch dargestellten Gehäuses bestehend aus drei Teilgehäusen,

Fig. 7

einen Längsschnitt eines Turboverdichters mit separatem Kühlsystem.

The invention will be described below with reference to several embodiments, wherein the same reference numerals refer to the same objects. Show it:

Fig. 1

a schematic arrangement of a known turbocompressor;

Fig. 2

a longitudinal section of a turbocompressor with an electric motor and a radial turbocompressor,

Fig. 3

a longitudinal section of a turbocompressor with both sides arranged radial turbocompressors,

Fig. 4

a further longitudinal section of a turbocompressor with radial turbochargers arranged on both sides,

Fig. 5

a longitudinal section through the junction of two sub-housing,

Fig. 6

a longitudinal section of a schematically illustrated housing consisting of three sub-housings,

Fig. 7

a longitudinal section of a turbocompressor with separate cooling system.

Fig. 1 shows schematically a known turbocompressor 1, which a Radial turbocompressor 3 with a shaft 3a and a driving Electric motor 2 comprises a shaft 2a. The shaft 3a of Radial turbocompressor 3 is supported by two radial bearings 5 on both sides. Likewise, the shaft 2a of the electric motor 2 by two radial bearings. 5 stored on both sides. The two shafts 2a, 3a are connected via a coupling 4 comprising two coupling parts 4a and 4b a flexible intermediate piece connected, so that the electric motor 2 via the shaft 2a and the coupling 4th the shaft 3a of the radial turbocompressor 3 drives.

Fig. 2 shows a turbocompressor 1, which in a hermetic sealed pressure housing 6 is arranged, wherein each one the Pressure housing 6 penetrating supply line 6c and 6d discharge provided is to the radial turbocompressor 3 fluid-conducting with an outside of the Pressure housing 6 arranged device to connect. The electric motor 2 comprises the rotor 2b and the stator 2c, wherein the rotor 2b part of the Motor shaft 2a, and the motor shaft 2a on both sides in the electromagnetic Radial bearing 5, each comprising a support device 5a and a electromagnetic coil 5b, is mounted in the radial direction. The Motor shaft 2a has a thrust bearing 7 against the radial turbocompressor 3 on, which is a part of the motor shaft 2a forming disc 2d as well comprises electromagnetic coils 7a. The motor shaft 2a is at the End section via a coupling 4 with the rotor 3a of the Radial turbocompressor 3 connected, with the opposite End portion of the rotor 3a is mounted in a radial bearing 5. The Motor shaft 2a and the rotor 3a form a common shaft 13. In Running direction of the rotor 3a are arranged two compressor wheels 3b, which a first compression stage 3c and a second compression stage Training. Not shown are the guide vanes 3f of Radial turbo-compressor 3. The main mass flow 8 of the compressed Fluids, preferably in the form of a gas, pass via the inlet opening 6a and the lead 6c enters and becomes the first compression stage 3c subsequently to the second compression stage 3d and subsequently via the Discharge 6d passed to the outlet opening 6b. A small fraction of the Main mass flow 8 is at the exit point of the first Compression level 3c derived via a connecting line 11 and as Cooling gas mass flow 9 a filter device 10 fed, which the Cooling gas mass flow 9 cleans of impurities, and the purified Cooling gas mass flow 9 as a coolant to the electromagnetic radial bearings 5 and the electric motor 2 supplies. In the illustrated embodiment the cooling gas mass flow 9 is flowing in the longitudinal direction of the housing, the radial bearing 5 and subsequently the electric motor 2 and the other Radial bearing 5 fed, the cooling gas preferably between the Wave 2a and the respective magnet 5b, 2c is performed. Of the Coolant gas mass flow 9 opens to the suction side of the first Compression level 3c, we compress this in turn, and is called Main mass flow 8 and / or further promoted as cooling gas mass flow 9. The connecting line 11 and the filter device 10 can within or be arranged outside of the pressure housing 6 extending. Of the Turbo compressor 1 according to the embodiment shown in Fig. 2 has the advantage that no seal the motor shaft 2a and the Runner 3a opposite atmosphere is required. In addition, there is no seal between the engine 2 and the first compression stage 3c required. The electric motor 2 is designed in such a way that this with Suction pressure or with standstill pressure is operable.

The turbo-compressor 1 could, of course, a plurality of in the direction of travel of the rotor 3a have arranged spaced compressor wheels 3b, so for example, a total of four, six, eight or ten compressor wheels 3 b. The compression pressure to be achieved is largely open to the top, wherein by a corresponding number connected in series Compressor wheels 3b, for example, a compression pressure of 600 bar is reachable. The turbocompressor 1 could also have one or more others Radial turbo compressor 3 and / or electric motors 2 include, which in Running direction of the rotor 3a, 2a are arranged, with all runs 3a, 2a to train a common wave. This common wave could be through Radial bearing, in particular magnetic radial bearings 5 be stored, wherein between each one Radialturboverdichter 3 preferably a single Radial bearing 5 is arranged. Preferably, all radial turbocompressors 3 together with the electric motor 2 or the electric motors 2 in one common, single pressure housing 6 is arranged.

The electromagnetic radial bearing 5 and the radial bearings. 5 associated portions of the shafts 2a and 3a have further, for a Professional self-evident and therefore not shown components on to form an electromagnetic radial bearing 5, such as electrical Coils, ferromagnetic parts, etc. The same applies to the electric motor 2, which is also shown only schematically.

Fig. 3 shows a longitudinal section of another embodiment of a Turbo compressor 1 comprising two radial turbocompressors 3, wherein at each Side of the electric motor 2 per a Radialturboverdichter 3 arranged and whose rotor 3a is connected via a coupling 4 with the motor shaft 2a. Only the upper half of the turbocompressor 1 is shown. It will only the opposite to the embodiment according to FIG. 2 essential Differences in detail described. The entire wave includes the Motor shaft 2a and the two rotor 3a is by four, in the longitudinal direction of the distributed throughout the wave electromagnetic radial bearings 5 stored. The left-hand radial turbocompressor 3 is as Low pressure part connected and has six compressor wheels 3b. Of the right radial turbocompressor 3 is as a high pressure part connected and has five compressor wheels 3b. Also shown are the vanes 3f. The main mass flow 8 passes through the supply line 6c in the low pressure part, and after compression over a Connecting line 12 is supplied to the high pressure part, wherein the Main mass flow 8 the high pressure part after compression over the Derivative 6d leaves. A small part of the main mass flow 8 is after the first compression stage 3c as the cooling gas mass flow 9 in the Conduction line 11 passed, said cooling gas mass flow 9 after the flow through the filter 10 that on the right side of the electric motor 2 arranged interior 9 c is supplied, and thereafter in the longitudinal direction the motor shaft 2 a flowing over the inner space 9 b of the suction port of the first compression stage 3c zuflust. Thus, a part of himself in the Radial turbo compressor 3 located process gas for cooling the Derived and used electric motor 2.

Between the right arranged Radialturboverdichter 3 and the Electric motor 2 is on the rotor 3a a non-contact seal 19th arranged to the internal pressure on the right side of the electric motor. 2 keep it low. The electric motor 2 is again designed to be operable at a suction pressure or a standstill pressure. The Connecting line 12 and / or the connecting line 11 and the Filter device 10 could also be completely inside the housing 6 be arranged running.

The radial turbo compressor 3 can, for example, in a "back to back "arrangement, in other words such that the by the two Radialturboverdichter 3 on the shaft caused forces in act in the opposite direction to such in the direction of the Motor shaft 2a acting shear forces to compensate and reduce.

The housing 6 is set in the embodiments according to FIGS. 3 and 4 from the three sub-housings 6e, 6f, 6g together, the sub-housings 6e, 6g form part of the radial turbocompressor 3 and the part housing 6f part of Engine 2 forms. The sub-housings 6e, 6f, 6g are adapted to one another in this way designed so that they, as shown in Figures 3 and 4, fixed can be connected to each other, for example by means of screws. At this Junctions can also be arranged seals to the To hermetically seal the interior of the housing 6 so that only over the intended lines 6c, 6d, 11, 12 or corresponding flanges a fluid-conducting connection between the interior of the housing. 6 and the outer space, due to the in Figs. 3 and 4 shown arrangement of the lines 11 and 12 only through the lines 6c, 6d and optionally through the discharge line 6i a fluid-conducting connection to the outside space exists. The joints can also do so be adapted to each other that arranged adjacent Part housing when pushed together and connect with respect to Longitudinal axis of the turbocompressor 1 automatically center each other. The two partial housings 6e, 6g each have an opening 23a in the outer wall which can be closed gas-tight with a cover 23b. In Fig. 3 is the in the sub-housing 6g arranged opening 23a with lid 23b shown. Of the Turbo compressor 1 is preferably prefabricated such that the Radial turbo compressor 3 is installed in the respective sub-housing 6e, 6g and the electric motor 2 is installed in the sub housing 6f. The like preconfigured sub-housing 6e, 6f, 6g are in the assembled State transported to the place of application. The assembly of the Turbo compressor 1 is as follows: After the sub-housing 6e, 6f, 6g on the Flanges 6k, 6l are firmly connected to each other, the shaft 3a and the rotor 2b at the outside accessible through the opening 23a Clutch 4 firmly connected. Thereafter, the opening 23 a with the lid 23b firmly and sealed gas-tight. The at the clutch 4 used fasteners, such as screws, are in themselves known and therefore not shown in detail.

The turbocompressor 1 shown in Fig. 4, in otherwise substantially the same configuration as the turbocompressor according to FIG. 3, in the housing part 6e a fluidically connected to the interior 9b outlet opening 6h and a subsequently arranged derivative 6i, through which the Cooling gas mass flow 9 and a minor proportion of Main mass flow 9a exits and example of a foreign investment Process source is supplied. This arrangement is opposite to the Embodiment according to FIG. 3 has the advantage that the pressure in the Derivative 6i subsequent device independent of the pressure in Radial turbo compressor 3 is, this pressure is preferably selected is that the engine cooling is done at a lower pressure level than in the Embodiment according to FIG. 3, which gives the advantage that the between the dissipation losses occurring in the rotating and static parts are reduced in the engine 2. Between the engine 2 and the Radial turbo compressor 3 is a seal 19 disposed on both sides. The Discharge 6i may be supplied to, for example, a compressor 24, which compresses the mass flow 9, 9a again the inlet opening 6a supplies. The suction pressure generated by the compressor in the discharge line 6i can for example, be lower than 50 bar.

In Fig. 4 also a control device 17 is shown, which at least for driving the electromagnetic radial bearing 5 and the motor 2 serves. In the area of the radial bearings 5 are sensors 16a, 16b, 16c, 16d arranged, which the position of the entire shaft 13 and the sub-waves 2a, 3a with respect to the radial bearings 5, the sensors 16a, 16b, 16c, 16d via electrical lines 16e, 16f, 16g, 16h with the control device 17 are connected. For controlling the magnetic coils of Radial bearing 5 are arranged electrical lines 15a, 15b, 15c, 15d, which are connected to the control device 17. There is also one electrical line 15 e is provided, which the control device 17 via a power electronics, not shown, with the winding of the Electric motor 2 connects.

Fig. 5 shows a longitudinal section through a housing 6, wherein the Junction of two sub-housing 6e, 6f is shown. The flange 6k of the first sub-housing 6e has a recess configured in this way, that the flange 6l of the second part housing 6f is received therein, wherein the mutual position of the two sub-housings 6e, 6f at Joining together by the flanges 6k, 6l are centered on each other. The Flanges 6k, 6l are distributed by several in the circumferential direction arranged screws 6m held together with nut 6n, wherein at the Face of the flanges 6k, 6l extending in the circumferential direction groove is provided, in which a sealing element 6o is arranged to the by the two sub-housing 6e, 6f limited interior to the outside seal.

6 shows a longitudinal section of a schematically illustrated housing 6 consisting of three sub-housings 6e, 6f, 6g with flanges 6k, 6l and a Supply line 6c and a derivative 6d. The housing 6 is about two Supporting elements 18a, 18b supported on a substrate 14. Within the Housing is arranged a base member 6p, which is a rigid, in Longitudinal direction of the housing 6 extending support, in particular a Supporting surface forms on which the electromagnetic radial bearings. 5 are arranged. The function of the basic elements 6p is one as possible stable and preferably temperature-insensitive reference plane too form, on which at least some radial bearings 5 are arranged. The Base member 6p may be configured in a variety of embodiments be, for example, as a solid, solid plate, as a carrier or as Grating. On the base element 6p further components such as Electric motor 2 or 3 Radialturboverdichter be anchored. The Using a base element 6p allows the electromagnetic Radial bearing 5 mutually very precise and in particular precisely aligned to arrange. The common arrangement of the radial bearing 5 on the Base element 6p has the advantage that due to attacking Tensile, compressive or shear forces or due to temperature influences mutual shifts of the radial bearings turn out very low. moreover This arrangement can be set up very quickly ready for use. In the From Fig. 1 known arrangement, it was necessary the two separate Devices electric motor 2 and radial turbocompressor 3 separated set up and in a time-consuming process exactly one another to align so that the shafts 2a, 3a are arranged in alignment. In spite of This effort can be the electric motor 2 and / or the Radial turbocompressor 3 or their radial bearings conditionally For example, by acting forces, a shift of Move background or temperature changes mutually.

The bearing force generated by electromagnetic radial bearings is much lower than that of known hydrodynamic bearings producible bearing force. That is why the exact mutual Alignment of electromagnetic radial bearings and preventing a mutual displacement of the radial bearings of central importance. The Electromagnetic radial bearing is usually operated such that the Shaft is held in the geometric center of the radial bearing. One mutual displacement of the radial bearing has the consequence that the Radial bearing has to expend considerable forces to the shaft anyway in the to hold geometric center. Since the electromagnetic radial bearing relative it soon gets into the state of magnetic saturation Radial bearing in this situation over lower, to carry the shaft to Available forces. This effect reduces the operational safety the turbocompressor, the electromagnetic radial bearing in the Extreme case is no longer able to carry the shaft. Therefore it is with the Use of electromagnetic radial bearings of central importance that they are arranged as precisely as possible in alignment, and that they are so are arranged that a mutual displacement of the radial bearing also is prevented as far as possible during operation of the turbocompressor. Therefore, it is also advantageous if the electromagnetic radial bearings in Course of the common shaft 13 a larger mutual Have distance. In the known embodiment according to FIG. 1 have the two central radial bearing 5 is a relatively small mutual distance, so that at a mutual offset of this two middle radial bearing 5 the problem can occur that this in generate radial forces against each other, which causes that the remaining power available for carrying the electromagnetic radial bearing is less or not at all Available.

Fig. 7 shows a turbocompressor 1 with a compared to Embodiment according to FIG. 4 separately cooled electric motor 2. It is between the pressure part of the radial turbocompressor 3 and the electric motor 2 each a system with a double seal, comprising a Dry gas seal 19 and subsequently a seal 20, arranged wherein between the two seals 19, 20 an outlet 21, as a vent (Exit to the atmosphere without gas combustion) or flare (exit to the Atmosphere with gas combustion) configured, which is arranged by the housing wall 6 runs. The electric motor 2 has a separate, separated by the seals 19, 20 from the radial turbo compressor 3 Cooling circuit on which a connecting line 11 and a radiator 22nd includes. The cooling gas mass flow 9 which cools the electric motor 2 flows between the stator 2c and the rotor 2b in the longitudinal direction, is in the range of the one end 9b of the electric motor 2 from the housing 6 in the Conduction line 11 passed, and is after flowing through the Cooler 22 and the subsequently arranged connection line 11 am another end 9c of the electric motor 2 is returned to the housing 6. Not shown are other components of this cycle, such as a Coolant gas driving device. A supply line 9d carries additional Cooling gas to, for example, the effluent via the discharge line 21 Compensate cooling gas components. As the cooling gas is not in particular aggressive gas such as nitrogen. The arrangement according to FIG. 7 is For example, then advantageous if no process gas at a low Pressure level for cooling the electric motor 2 is available, or if the process gas has aggressive properties or is dirty is, for example, by liquid gas impurities, so this For example, parts of the electric motor 2, such as the shaft 2a or the electrical insulation, could damage. The cooling circuit of the Electric motor 2 may be designed such that this pressure in the Range of atmospheric pressure or slightly above it. As in 7, the cooling circuit can be designed such that a small proportion of the cooling gas mass flow 9 via the seal 20 for Outlet 21 arrives. This ensures that the Coolant gas mass flow 9 is not contaminated by foreign gases. in the Embodiment according to FIG. 7 also flows a small proportion of Process gas 8 via the seal 19 to the outlet 21. The outlet 21 can a so-called flare or vent be subordinate to that from the Outlet 21 discharged gases unburned vent (vent) or via a subsequent combustion (flare) dissipate, especially to the environment leave.

An advantage of the embodiment according to FIG. 7 can be seen in that the cooling gas 9 has a low pressure and / or that as a cooling gas favorable or easily manageable gas is used, in particular a gas without aggressive properties.

An advantage of the turbocompressor 1 according to the invention can be seen therein that the electric motor 2 and the radial turbocompressor 3 together with the corresponding housing parts 6e, 6f are preassembled, so that the Turbo compressor 1 as a housing 6 or as a unit for Site is transportable and can be set up there.

The extending in Figures 3, 4 and 7 outside the housing 6 Lines 11, 12 and the associated components 22, in a further embodiment also within the housing. 6 be arranged running.

Claims (8)

1. Turbo-compressor comprising a casing (6), gas-tight towards the outside, within which an electric motor (2) as well as a multiple-stage radial-flow turbo-compressor (3) are arranged on a common shaft (13), wherein for the support of shaft (13) electro-magnetic radial bearings (5) are arranged with spacing in the running direction of said shaft, wherein a gas seal (19) surrounding shaft (13) is placed between electric motor (2) and radial-flow turbo-compressor (3) in order to seal electric motor (2) towards radial-flow turbo-compressor (3), wherein either end section of electric motor (2) is provided with an inside chamber (9b, 9c), and wherein one of the inside chambers (9c) is connected in a fluid-conductive form with an outlet port (6h, 21) penetrating the casing, characterized in that inside chambers (9b, 9c) of electric motor (2) are connected through a connection line (11) in such a fluid-conductive form that a closed fluid cycle (9) is formed through the gap between stator (2c) and rotor (2b) of electric motor (2) and connection line (11).
2. Turbo-compressor according to claim 1, characterized in that inside chamber (9b) of one end section of electric motor (2) is connected in a fluid-conductive form with one compressor stage.
3. Turbo-compressor according to claim 1 or 2, characterized in that the closed cycle (9) is connected with a feed line (9d) in a fluid-conductive form in order to deliver a separate fluid, in particular nitrogen, to cycle (9).
4. Turbo-compressor according to one of claims 1 to 3, characterized in that the closed fluid cycle (9) comprises a cooler (22).
5. Turbo-compressor according to one of claims 1 to 4, characterized in that a seal (20) is placed between inside chamber (9b) of one end section of electric motor (2) and outlet port (21) at shaft (13).
6. Turbo-compressor according to one of claims 1 to 5, characterized in that outlet port (21) ends in a flare or vent or is connected in a fluid-conductive form with the suction side of a compressor (24).
7. Turbo-compressor (1) according to one of claims 1 to 6, characterized in that one radial-flow turbo-compressor (3) is arranged at either side of electric motor (2).
8. System comprising a turbo-compressor according to one of claims 1 to 7.

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