DE3337132A1 - Expansion turbine with coupled compressor - Google Patents

Abstract

The rotor discs 12, 13 of the expansion turbine and compressor are over-mounted on a common shaft 11. The rotor discs 12, 13 of the expansion turbine and compressor, the shaft 11, the shaft bearings and the bearing support 10 are constructed as a constructional unit, to achieve a simple and maintenance-friendly design. The said unit is arranged in a housing 1 which is common to the expansion turbine and the compressor, and which has a gas inlet connection 17, 22 and a gas outlet connection 18, 21 for both the expansion turbine and the compressor. <IMAGE>

Description

LINDE AKTIENGESELLSCHAFT

_{(p. 447)} p. 83/81

Sln / bd 11.10.83

Expansion turbine with coupled compressor

The invention relates to an expansion turbine with a coupled compressor, in which the impellers of the expansion turbine and compressor are cantilevered on a common shaft.

The principle of cold generation through work-related expansion of a gas has been known for a long time and is used in various types of air and gas separation plants. Expansion turbines, mostly in the form of radial turbines with gas flow from the outside to the inside, are used in all systems with a higher output. The power extracted from the gas is transferred from the turbine either via a gearbox or an electric generator to the network or to an oil vortex brake or air brake located on the same shaft as the turbine wheel, or to a turbo compressor wheel that is attached to the free end of the turbine shaft. For reasons of thermal insulation, in the last-mentioned design the turbine wheel is cantilevered in its own housing on one shaft end, and the turbo compressor wheel is also cantilevered in its own housing on the other shaft shape. 5729 7.78

end attached. Between turbine housing and compressor. housings are in a special bearing bracket to which both Housing can be flanged, shaft seals, bearings and speed sensors attached.

Such expansion turbine compressor units are also used in the cooling of natural gas in dew point systems or other systems for the separation of gas mixture components, such as heavy hydrocarbons. In In the same construction as described above, the natural gas with the turbine wheel is expanded and the expanded gas lean natural gas, which is now passed through appropriate groups of equipment to separate the gas mixture components with the turbo compressor wheel sitting on the other end of the shaft condensed again, e.g. to be released into a pipeline.

A disadvantage with such known expansion turbine-compressor assemblies consists in the fact that for the inspection or repair of the bearings, seals and the turbine and compressor impellers first dismantled one of the two housings, the flanged gas supply line and gas discharge line loosened, unscrewed the bearing bracket from the second housing and then with the shaft, bearings and turbine as well Compressor impeller must be withdrawn from this. Depending on the size of the expansion turbine-compressor unit are to be added Slide rails and hydraulic tools required. The assembly is then carried out in the reverse order, hydraulic clamping devices must also be used. Another disadvantage of this type of construction consists in the fact that the discharge duct of the expansion turbine runs in the axial direction, which results in variable Mass flows result in a swirl flow in the turbine outlet which reduces the efficiency.

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The invention is based on the object of designing an expansion turbine of the type mentioned at the outset in such a way that the above disadvantages can be avoided in a simple and economical manner and with simple and maintenance-friendly structure an economical mode of operation is possible.

This object is achieved according to the invention in that the impellers of the expansion turbine and compressor, the shaft, the shaft bearing and the bearing bracket as a complete set Structural unit are formed, this structural unit is arranged in a housing common to the expansion turbine and compressor and the housing has a gas inlet nozzle and a gas outlet nozzle for the expansion turbine and compressor having.

With such a construction of the expansion turbine-compressor unit and the arrangement in only one housing need to remove the impellers, the shaft and the shaft bearings and the structural unit comprising the bearing support, the connecting lines to the gas inlet nozzle and gas outlet nozzle not to be resolved. This results in a significant reduction in downtime Maintenance and repair work, with the structural unit being replaced completely and very quickly if necessary can be. In addition, a compact design is possible with the use of only one housing, which allows the maintenance of high pressures and high performance ranges. This is not least due to that the complete assembly of shaft, shaft bearing and bearing bracket with the overhung on both The impellers of the expansion turbine and compressor arranged at the ends of the shaft can be made very short can. Because the bearings are then close together, a largely rigid one that can hardly be made to vibrate Formation of the wave and thus in addition to a loading

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driven with subcritical speeds, operation with supercritical speeds is also possible.

For a cost-effective construction of the expansion turbine with a compressor, it is particularly expedient to have the housing to be designed as a pot housing with the housing covers assigned to the open sides. With this design of the housing there is no problem with the complete assembly of impellers, shafts and shaft bearings and bearing brackets. after removing one of the housing covers from the housing. In addition, a such a housing in a simple manner, for example by casting or in a welded construction The gas inlet and gas outlet nozzles are cast on at the same time, depending on the manufacturing method of the housing or can be welded on at a later date. The attachment of the gas inlet and gas outlet nozzles on the housing can be made fluid mechanically "in such a way that the turbine inlet and Compressor outlet tangential, turbine outlet and compressor inlet are arranged radially.

A simple structure is advantageously also achieved in that the housing cover has shear rings are fixed in the housing.

To on the compressor or. Turbine impeller to obtain an inlet or outlet that is favorable in terms of fluid mechanics, it is also advantageous to arrange and intermediate floors between the bearing bracket and the housing covers the intermediate floor together with the housing covers to an outflow channel for the expansion turbine and to to form an inflow channel for the compressor. For this it is only necessary to have both the intermediate floor and remove the housing cover on the inside wall of the housing.

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support, the intermediate floors for a radial inflow and outflow with a bore that widens away from the impellers and the housing cover with an axially on the To provide impellers tapering and into the bore of the intermediate floor protruding guide device.

To contrast, in a simple manner in the housing also an inflow channel to the impeller of the expansion turbine and a Outflow channel from the impeller of the compressor to be able to, it is also useful to open between the intermediate floor and the bearing bracket to the running wheels Form pressure chambers and the one pressure chamber the gas inlet port of the expansion turbine and the other Allocate the pressure chamber to the gas outlet nozzle of the compressor. All that is needed is a pressure-tight connection required at least between the inner wall of the housing and the intermediate floor. So that they can also be supported in the axial direction on the bearing bracket, the intermediate floor have a U-shaped cross-section, the legs both on the housing inner wall and on the Bearing bracket.

If the bearing bracket is also connected to the inner wall of the housing in a pressure-tight manner, there is still an advantageous manner the possibility of forming a non-pressurized space between the bearing bracket and the inner wall of the housing. Due to the unpressurized state, this space can open to the environment without any structural effort for the supply and discharge of lubricating oil as well as for the reception of measuring elements.

To protect the axial bearing, a further advantageous embodiment of the invention provides in to arrange axial probes for axial thrust control on the housing lids and to switch them off to a device

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to be connected in case of overload. The arrangement of the axial probes can be done, for example, in the bores of the housing cover, which are in the on the impellers of the turbine and compressor running guide devices of the housing cover are executed. -

In the drawing, an embodiment of an expansion turbine according to the invention with a compressor is shown schematically.
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1 with a tubular pot housing is referred to, which on closed at both ends by means of a U-shaped housing cover 2, 3 is. Their legs rest on the circumference of the inner wall of the housing 1, while the inwardly directed Leg ends are in turn on intermediate floor 6, 7 which is U-shaped in cross section. On the outside the housing covers 2, 3 are secured against axial displacement by shear rings 4, 5 engaging in the housing 1.

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The legs of the U-shaped intermediate floors 6, 7 are located also on the circumference of the housing inner wall, while the leg ends are in turn on supports 8, 9, which are welded, for example, to the inner wall of the housing ', over the supports 8, 9 is designed as a rotating part Bearing bracket 10 supported in housing 1, bearing bracket 10 screwed to only one support 8 or is attached with shear rings and is only pushed into the other support 9. The bearing carrier 10 are the shaft 11 of the expansion turbine and compressor together with the shaft bearing, the shaft seal and assigned to the channels required for lubrication. On the left end in the figure of the shaft 11 is the impeller 13 of the expansion turbine and on the right "end of the shaft 11 the impeller 12-des Overhung compressor.

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Within the supports 8 _f 9 and between the bearing bracket 10 and the housing inner wall, a pressureless space 14 is formed which has openings to the environment, for example for the supply and discharge of lubricating oil and for receiving measuring elements. These feed and discharge lines and the measuring elements are not shown for the sake of clarity. This intermediate space 14 can, however, also be directly under the pressure of a pressurized oil system, in which case corresponding flange connections for the oil supply and oil discharge can be arranged on the housing wall.

Outside the supports 8, 9 are between these and the U-shaped intermediate floors 6, 7 pressure spaces 15, 16 formed, which are open to the impellers 12, 13 of the compressor and expansion turbine. These pressure spaces 15, 16 are on the outside of the housing 1 of the gas inlet nozzle 17 to the expansion turbine or the gas outlet nozzle 18 assigned to the compressor. The gas inlet connection 17 and the pressure chamber 15 of the expansion turbine are here expediently designed so that there is a pre-swirl, while the pressure chamber 16 and the Gas outlet nozzle 18 of the compressor are designed for a spiral-like flow.

For the gas discharge from the expansion turbine or for the gas feed line to the compressor, there are intermediate floors 6, 7 and the housing covers 2, 3 in turn formed pressure-resistant spaces 19, 20, with on the outside of the housing 1, one of the gas outlet nozzles 21 of the expansion turbine and the other of the gas inlet nozzles 22 of the compressor are assigned. To enable a swirling flow in both cases, are both intermediate floors 6, 7 with one on the shape of the impellers 12, 13 of the compressor and expansion tower

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bine matched / outwardly in the direction of the housing cover 2, 3 widening channels.23, 24 provided, in the arranged on the housing covers 2, 3,
Guide devices 25, 26 extending axially onto the running wheels 12, 13 protrude. In these guide devices 25, 26 there are bores 27, 28 in which axial probes 29, 30 are arranged for axial thrust control. These are connected to a device, not shown, for disconnection in the event of an overload.

The channel 23, which acts as a turbine outlet diffuser, is expediently designed as a radial diffuser, there with a radial diffuser with a swirling turbine outlet flow in the off-design operating state common axial diffusers achieve higher efficiencies can be.

With this construction of expansion turbine and compressor, all that is required to remove the structural unit consisting of bearing bracket 10, shaft 11 with impellers 12, 13, shaft bearings and shaft seals is to remove the shear ring 4 located in the housing on the compressor side, the corresponding housing cover 2 and the
intermediate floor 6 assigned to it from housing 1

and then the fastening of the

Bearing carrier 10 to solve on the support 8. The inlet and outlet lines to the compressor do not need to be removed. Due to the floating mounting, the
Impellers 12, 13 of the compressor and expansion turbine

a short, compact design of the shaft and the bearing carrier and thus ultimately also of the housing is possible, whereby a correspondingly constructed expansion turbine with compressor for high pressures and power ranges
suitable is.

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A further simplification of the structure is possible by assigning the supports 8, 9 to the bearing bracket 10, so that a complete slide-in unit is created, which extends over the intermediate floor 6 and 7 and the housing cover 2 and 3 is supported on the shear rings 4 and 5. This allows the supports 8, 9 to be welded to the inner wall of the housing and the arrangement of connecting screws between the individual elements of the pot housing is omitted.

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Claims (7)

(S 447) S 83/81 Sln / bd
10/11/83
10 Patent to sayings (1.) Expansion turbine with a coupled compressor, in which the impellers of the expansion turbine and compressor are overhung on a common shaft, characterized in that 'the impellers (12, 13) of
Expansion turbine and compressor ,, the shaft (11) ;, the 2Q shaft bearing and the bearing bracket (10) are designed as a structural unit, this structural unit in a housing (1) common to the expansion turbine and compressor
is arranged and the housing (1) each have a gas inlet nozzle (17, 22) and a gas outlet nozzle zen (18, 21) for expansion turbine and compressor. 2. Expansion turbine according to claim 1, characterized in that the housing (1) as a pot housing with the offe- _. NEN sides assigned housing covers (2, 3) formed is. 3. Expansion turbine according to claim 2, characterized in that the housing cover (2, 3) via shear rings (4, 5) are fastened in the housing (1). Shape. 5729 7.78 4. Expansion turbine according to one of claims 1 to 3, characterized in that between the bearing bracket (10) and the housing covers (2, 3) intermediate floors (6, 7) are arranged and the intermediate floors (6, 7) together with the housing covers (2, 3) to an outflow channel for the expansion turbine and to an inflow channel for the compressor are trained. 5. Expansion turbine according to claim 4, characterized in that between the intermediate floors (6, 7) and the Bearing carrier (10) open to the running wheels (12, 13) Pressure chambers (15, 16) are formed and the one. Pressure chamber (15) of the gas inlet nozzle (17) of the expansion turbine and the gas outlet nozzle (18) of the compressor is assigned to the other pressure chamber (16). 6. expansion turbine according to one of claims 1 to 5, characterized in that between the bearing bracket (10) and the inner wall of the housing there is an unpressurized intermediate space (14) is formed. 7. Expansion turbine according to one of claims 2 to 6, characterized in that in the housing covers (2, 3) Axial probes (29, 30) are arranged for axial thrust control and these with a device for switching off are in operative connection in the event of an overload. Shape. 5729 7.78