RADIAL COMPRESSOR

Abstract

A compressor having a rotor which extends along an axis of rotation, a housing, wherein the housing is arranged around the rotor, wherein the housing has an axial inflow and, downstream of the axial inflow, a first compression stage and, further downstream of the first compression stage, a radial outflow for a process fluid, the radial outflow leading through the housing, and an impeller which is arranged on the rotor, with an injection device for injecting a fluid into the axial inflow.

Claims

1. A compressor comprising: a rotor which extends along a rotation axis, a housing, wherein the housing is arranged around the rotor, wherein the housing has an axial inflow and downstream of the axial inflow has a first compressor stage and further downstream of the first compressor stage has a radial outflow for a process fluid, wherein the radial outflow leads through the housing, an impeller which is arranged on the rotor, characterized by an injection apparatus for injecting a liquid into the axial inflow, wherein the process fluid which is intended to be compressed is initially drawn in and a quantity of injected liquid is carried out in accordance with a temperature and relative humidity of a medium drawn in.

2. The compressor as claimed in claim 1, wherein an evaporation temperature of the liquid is lower than the temperature of the process fluid which is intended to be compressed after injection in the first compressor stage.

3. The compressor as claimed in claim 1, further comprising a control device which is configured in such a manner that the quantity of injected liquid can be controlled.

4. The compressor as claimed in claim 1, wherein the injection apparatus is configured in such a manner that the injection of the liquid is carried out within the medium which is intended to be compressed.

5. The compressor as claimed in claim 1, wherein the injection of the liquid is carried out in front of the impeller.

6. The compressor as claimed in claim 1, wherein the compressor has a helical stage and the injection of the liquid is carried out in the helical stage.

7. The compressor as claimed in claim 1, wherein the compressor has an inlet and the injection of the liquid is carried out in the inlet.

8. The compressor as claimed in claim 1, wherein the compressor has a return stage and the injection of the liquid is carried out in the return stage.

9. The compressor as claimed in claim 1, wherein the injection of the liquid is carried out via a plurality of nozzles.

10. The compressor as claimed in claim 9, wherein the compressor has an impeller inlet having an impeller inlet diameter, wherein a spacing between a last nozzle in front of the impeller and the impeller inlet is three times the impeller inlet diameter.

11. The compressor as claimed claim 9, wherein the compressor has an impeller inlet having an impeller inlet diameter, wherein a spacing between a last nozzle in front of the impeller and the impeller inlet is 10 times the impeller inlet diameter.

12. The compressor as claimed in claim 9, wherein the plurality of nozzles are arranged with spacing from each other in an axial direction and form a cascading injection.

13. The compressor as claimed in claim 9, wherein the plurality of nozzles are arranged to be offset from each other.

14. The compressor as claimed in claim 9, wherein the quantity of injected liquid can be controlled by switching the plurality of nozzles on and off.

15. The compressor as claimed in claim 1, wherein the quantity of injected liquid can be controlled by a speed.

16. The compressor as claimed in claim 1, wherein the quantity of injected liquid is carried out by means of a bypass control.

17. The compressor as claimed in claim 1, wherein the injection apparatus for injection is configured in such a manner that an admixture of water and alcohol can be injected.

18. The compressor as claimed in claim 1, wherein the injection apparatus for injection is configured in such a manner that an admixture has water and ethanol and/or water and methanol.

19. The compressor as claimed in claim 1, in a form of a radial compressor.

20. The compressor as claimed in claim 19, wherein the compressor is configured in one stage.

21. The compressor as claimed in claim 19, wherein the compressor is configured with multiple stages.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0034] FIG. 1 shows a sectioned illustration of a radial compressor according to the prior art;

[0035] FIG. 2 shows a longitudinal section through a schematic illustration of a first compressor according to an embodiment of the invention.

[0036] Terms such as axial, radial, tangential or circumferential direction refer to an X axis of a rotor unless stated otherwise.

DETAILED DESCRIPTION OF THE DRAWINGS

[0037] FIG. 1 shows a known radial flow machine in a (simplified) sectioned illustration. The flow machine illustrated is a compressor 1, in particular a radial compressor.

[0038] The flow machine includes inter alia a radial impeller 2 which is rotatably supported about a rotation axis 3. The impeller 2 has an axial inflow 4 and a radial outflow 5.

[0039] Furthermore, the impeller 2 includes a hub 6 and impeller blades 7 which protrude radially from the hub 6. Between the impeller blades 7, there are formed flow channels through which a fluid can flow. Furthermore, the hub 6 is connected to a shaft (which is not illustrated in the Figures) of the compressor.

[0040] Furthermore, the impeller 2 has a wheel disk 8 which is formed in one piece with the hub 6 and which connects the impeller blades 7 to each other. In the present exemplary embodiment, the impeller 2 is a so-called open impeller, that is to say, an impeller without any covering plate. In an alternative embodiment (not illustrated in the Figures), the impeller 2 could also be a so-called closed impeller, that is to say, an impeller with a covering plate.

[0041] Furthermore, the compressor 1 includes a housing 9 in which the impeller 2 is placed. A portion of the housing 9 is in the form of a helical housing. That is to say, the housing 9 has a helical housing portion 10 having a helical hollow space 11.

[0042] Furthermore, the compressor has an annular diffusor 12 which is axially symmetrical with respect to the rotation axis 3 and which is in the form of a hollow chamber or a channel in the housing 9. The diffusor 12 is arranged around a circumference of the impeller 2 and is in the form of a radial diffusor. Furthermore, the diffusor 12 opens in the helical housing portion 10 or in the hollow space 11 thereof.

[0043] Furthermore, in FIG. 1, an outlet diameter 13 of the impeller 2 is indicated in the form of a double-headed arrow.

[0044] Furthermore, the diffusor 12 has a plurality of diffusor blades 14. That is to say, the diffusor 12 is a bladed diffusor. In the present exemplary embodiment, the diffusor 12 has six diffusor blades 14 of which only two can be seen in FIG. 1. In principle, however, the diffusor 12 could also have a different number of diffusor blades 14.

[0045] The compressor 1 is used to compress a fluid, such as, for example, air. During operation of the compressor 1, the fluid flows axially through the axial inflow 4 into the impeller 2 or into the flow channels formed by the impeller blades 7. The fluid is caused to rotate by the impeller 2 and leaves the impeller 2 radially in an outward direction through the radial outflow 5.

[0046] From there, the fluid discharged from the impeller 2 flows into the diffusor 12. The diffusor 12 converts a portion of the kinetic energy of the fluid into potential energy in the form of pressure and guides the fluid into the hollow space 11 of the helical housing portion 10.

[0047] FIG. 2 shows a longitudinal section of a schematic illustration of a portion of the compressor 1 having an injection apparatus 15 according to an embodiment of the invention. At the left edge of FIG. 2, a portion of the axial inflow 4 can be seen. The double-headed arrow indicates an impeller inlet diameter 16. The impeller inlet 17 is arranged in front of the impeller 2 which is not illustrated in FIG. 2.

[0048] There is arranged at the impeller inlet 17 an inflow housing 18 and they are connected to each other by means of a plurality of flanges 19.

[0049] At a spacing 20, a nozzle 21 is arranged in the inflow housing 18. The nozzle 21 is formed to supply liquid. In this instance, a process fluid which flows from the right is moved in the direction of the compressor 1 and by means of the nozzles 21 a liquid reaches the process fluid.

[0050] In this instance, the evaporation temperature of the liquid is lower than the temperature of the process fluid which is intended to be compressed after the injection in the compression process.

[0051] Furthermore, the injection apparatus 15 has a control device which is not illustrated in greater detail and which is configured in such a manner that the quantity of injected fluid can be controlled.

[0052] In this instance, the injection apparatus 5 is configured in such a manner that the process fluid which is intended to be compressed is initially drawn in and the quantity of injected fluid is produced in accordance with the temperature and relative humidity of the process fluid drawn in.

[0053] As can be seen in FIG. 2, the injection apparatus 15 is configured in such a manner that the injection of the liquid is carried out within the process fluid which is intended to be compressed.

[0054] The injection apparatus 15 may have a plurality of nozzles 21 (not illustrated) which are arranged one behind the other in the flow direction of the process fluid.

[0055] It has been found that the effect of the injection is advantageous when the spacing 20 between the last nozzle 21 in front of the impeller 2 and the impeller inlet 17 is 3 times the impeller inlet diameter 16.

[0056] Another advantageous effect is evident when the spacing 20 between the last nozzle 21 in front of the impeller 2 and the impeller inlet 17 is from 0.5 to 0.75 times, preferably 0.66 times the impeller inlet diameter 16.

[0057] The injection apparatus 15 has a particularly effective action when the spacing 20 between the last nozzle 21 in front of the impeller 2 and the impeller inlet 17 is 10 times the spacing 22 of the impeller inlet diameter 16.

[0058] Another possibility of improving the effectiveness of the injection apparatus 5 is achieved in that a plurality of nozzles are arranged are behind the other in the flow direction. An improved mixing is thereby possible. In FIG. 2, this improved arrangement is illustrated schematically by a first line 23 and a second line 24.

[0059] Both on the first line 23 and on the second line 24, additional nozzles (not illustrated) are arranged. The spacing between the nozzles 21 and the position which corresponds to 10 times the spacing 22 is the length L. The spacing between the nozzles 21 and the additional nozzles at the position on the first line 23 substantially corresponds to a third of the length L.

[0060] The spacing between the additional nozzles at the first position 23 and the additional nozzles at the position on the second line 24 substantially corresponds to a third of the length L.

[0061] The spacing between the additional nozzles at the second position 24 and the position which corresponds to 10 times the spacing 22 is substantially a third of the length L.

[0062] In FIG. 2, only two additional positions for additional nozzles are illustrated. Additional nozzles which are arranged with spacing from each other are also conceivable.