Assembly having two compressors, method for retrofitting

Abstract

An assembly having a first compressor train and a second compressor train for compressing a process fluid, wherein the first compressor train has a first drive and a first compressor, wherein the second compressor train has a second drive and a second compressor, wherein the first compressor train is not mechanically coupled to rotating parts of the second compressor train for transmission of torque, wherein the two compressors of the different compressor trains are directly connected to each other fluidically by a connecting fluid line such that the first compressor is arranged upstream of the second compressor. The first compressor compresses at a pressure ratio between 1.1 and 1.6 before the process fluid is fed to the second compressor.

Claims

1. An arrangement comprising: a first compressor train and a second compressor train for compressing a process fluid, wherein the first compressor train comprises a first drive and a first compressor, wherein the second compressor train comprises a second drive and a second compressor, wherein the first compressor train is not mechanically coupled in torque-transmitting fashion to rotating parts of the second compressor train, wherein the first compressor and the second compressor are directly connected in fluid-conducting fashion to one another by means of a connecting fluid line, in such a way that the first compressor is arranged upstream of the second compressor, wherein the first compressor compresses with a pressure ratio between 1.1 and 1.6 before the process fluid is fed to the second compressor, wherein the second compressor is in the form of a geared compressor comprising a gearing housing on the outside of which are mounted plural spiral housings of respective radial compressor stages, wherein the respective radial compressor stages are arranged sequentially with respect to compressed air flowing therethrough, and wherein the second compressor is a constituent part of a gas turbine and supplies the compressed air to a turbine of the gas turbine.

2. The arrangement as claimed in claim 1, wherein the second compressor compresses with a pressure ratio between 3 and 60 while the first compressor compresses with the pressure ratio between 1.1 and 1.6.

3. The arrangement as claimed in claim 1, wherein the first drive is either a second gas turbine or a steam turbine or an electric motor.

4. The arrangement as claimed in claim 1, wherein the second compressor compresses with a pressure ratio that is at least 3.8 times higher than the pressure ratio of the first compressor.

5. The arrangement as claimed in claim 1, wherein the first compressor comprises a fan or a blower.

6. The arrangement as claimed in claim 1, wherein the first compressor comprises at least one first compressor stage and second compressor stage, and wherein the first drive is arranged between the at least one first compressor stage and the second compressor stage.

7. The arrangement as claimed in claim 1, wherein the first compressor is in the form of an at least two-stage radial compressor comprising a first compressor stage and a second compressor stage, wherein the first compressor stage and the second compressor stage each comprise an intake side and a wheel disk side, and wherein a wheel disk side of the first compressor stage faces axially toward a wheel disk side of the second compressor stage, and wherein intake of the first compressor stage and the second compressor stage occurs in axially opposite directions.

8. The arrangement as claimed in claim 7, wherein the first drive is arranged axially between the wheel disk side of the first compressor stage and the wheel disk side of the second compressor stage.

9. The arrangement as claimed in claim 1, wherein the first compressor train is arranged upstream of a filter and the process fluid is conducted into the second compressor only after passing through the filter.

10. The arrangement as claimed in claim 1, wherein a filter is arranged upstream of the first compressor, and the process fluid is conducted directly from the first compressor into the second compressor without passing the filter.

11. The arrangement as claimed in claim 1, wherein at least one surging protection device is provided between the first compressor and the second compressor, wherein the at least one surging protection device comprises a closing device, and wherein, in the event of surging, the closing device closes at least 80% of a flow cross section of the connecting fluid line between the first compressor and the second compressor.

12. The arrangement as claimed in claim 1, wherein at least one surging protection device is provided between the first compressor and the second compressor, wherein the at least one surging protection device comprises a pressure relief device which, in the event of surging of the first compressor and/or of the second compressor, relieves the connecting fluid line between the first compressor and the second compressor, or at least a section of the connecting fluid line between the first compressor and the second compressor, of pressure and/or pressure shocks through an opening and into a pressure sink.

13. The arrangement as claimed in claim 11, wherein the first compressor is an axial compressor.

14. The arrangement as claimed in claim 1, wherein the first compressor is in the form of a radial compressor and no surging protection device is provided upstream of the second compressor.

15. The arrangement as claimed in claim 11, wherein the closing device is designed such that, in the event of a backflow of the process fluid from the second compressor train to the first compressor train, the closing device, driven by the back-flowing process fluid, blocks the connecting fluid line over at least 80% of the flow cross section.

16. The arrangement as claimed in claim 11, wherein the closing device is connected to a slide valve and a mechanical thrust arising from a reverse differential pressure across the closing device moves the slide valve into an opening position, such that the connecting fluid line between the first compressor train and the second compressor train is thereby connected to a pressure sink, such that a release of pressure from the connecting fluid line occurs.

17. A method for retrofitting and/or adding a first compressor train to a second compressor train of an existing installation, the method comprising: providing the first compressor train and the second compressor train for compressing a process fluid, wherein the first compressor train comprises a first drive and a first compressor, wherein the second compressor train comprises a second drive and a second compressor, wherein the first compressor train is not mechanically coupled in torque-transmitting fashion to rotating parts of the second compressor train, directly connecting the first compressor and the second compressor in fluid-conducting fashion to one another by means of a connecting fluid line, in such a way that the first compressor is arranged upstream of the second compressor, wherein the first compressor compresses with a pressure ratio between 1.1 and 1.6 before the process fluid is fed to the second compressor, wherein the second compressor is in the form of a geared compressor comprising a gearing housing on the outside of which are mounted plural spiral housings of respective radial compressor stages, wherein the respective radial compressor stages are arranged sequentially with respect to compressed air flowing therethrough, wherein the second compressor is a constituent part of a gas turbine and supplies the compressed air to a turbine of the gas turbine.

18. The method as claimed in claim 17, wherein, in a step of the retrofitting, the second compressor is aerodynamically modified such that a pressure ratio of the second compressor is reduced in relation to a state before the retrofitting.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Below, the invention will be described in more detail on the basis of a number of exemplary embodiments with reference to drawings, in which:

(2) FIG. 1 shows a schematic process overview of an arrangement according to the invention,

(3) FIG. 2 is a three-dimensional schematic illustration of an arrangement according to the invention,

(4) FIG. 3 shows a schematic depiction, in longitudinal section, of a combination of a filter with a first compressor train,

(5) FIG. 4 shows another embodiment of a first compressor train,

(6) FIG. 5 is a schematic illustration, in cross section, of a first compressor train of modular design,

(7) FIG. 6 shows a schematic longitudinal section through an arrangement according to the invention with a first compressor train, the first compressor of which is in the form of a radial blower,

(8) FIG. 7 is a schematic illustration of a first compressor train as a radial blower in longitudinal section through the first compressor,

(9) FIG. 8 shows an alternative embodiment in relation to the illustration of FIG. 7,

(10) FIG. 9 shows an exemplary embodiment of a surging protection means downstream of a first compressor, in the form of a radial blower, with an attached filter,

(11) FIG. 10 shows a closing device of a surging protection means,

(12) FIG. 11 shows a surging protection means, with a combined closing device and relief device in a first operating position in a closed position of the relief device,

(13) FIG. 12 shows the surging protection device as per FIG. 11 in a second operating position in an open position of the relief device.

DETAILED DESCRIPTION OF INVENTION

(14) An arrangement according to the invention having a first compressor train CT1 and a second compressor train CT2 is depicted in FIG. 1 in a schematic illustration in a plan view onto the longitudinal axis of the overall arrangement. A process fluid PF is taken in through a filter FIT, FIT and, in a first compressor CO1, which is in the form of a blower, of a first compressor train CT1, said process fluid is raised to a higher pressure level. FIG. 1 shows two alternative embodiments of the filter FIT, FIT. In a first possible embodiment, the filter FIT is situated in a housing which is separate from the first compressor train CT1. In the second embodiment, the filter FIT is situated in a common housing with the first compressor train CT1.

(15) After emerging from the first compressor CO1 of the first compressor train CT1, the process fluid PF passes into a connecting fluid line CFC situated downstream and, further downstream, to a second compressor train CT2. The second compressor train CT2 has a second compressor CO2 which is in the form of a geared compressor, such that a first compressor stage CO21 of the second compressor CO2 is driven by means of a first gearing GR1 and a second compressor stage CO22, situated downstream, of the second compressor CO2 is driven by means of a second gearing GR2. The first gearing GR1 and the second gearing GR2 are driven by means of a second drive DR2, wherein, in a manner which is not illustrated, the two gearings GR1, GR2 are constituent parts of a common gearing of the geared compressor.

(16) Such geared compressors are basically known. These are gearing housingswhich are relatively largeon the outside of which spiral housings of the individual compressor stages are flange-mounted. In general, in the gearing, there is arranged a large gear which is driven by a common drive for the individual compressor stages. Normally, said drive is, outside the gearing housing, connected in torque-transmitting fashion to the gearing housing by means of a clutch. The individual compressor stages are driven by means of pinion shafts, of which at least one shaft end, normally both shaft ends, project out of the gearing housing. The impellers of the individual compressor stages are attached, generally so as to be mounted in floating fashion, on the projecting-out shaft ends. Between the individual compressor stages of the geared compressor, the process fluid may be fed to other processes or may simply undergo cooling. Alternatively, the process fluid may also be transferred from one compressor stage directly to the next compressor stage by means of a connecting fluid line. In FIG. 1, an intercooler ICL between the two compressor stages CO21, CO22 of the second compressor CO2 is illustrated. After the compression in the second compressor CO2 of the second compressor train CT2, the process fluid PF is conducted to further processes PRO.

(17) The compression in the first compressor train CT1 takes place with a pressure ratio between 1.1 and 1.6. The second compressor train CT2 compresses the process fluid PF to a final pressure of approximately 3 to 60 bar. The intake of the first compressor train CT1 occurs approximately under atmospheric conditions, wherein the process fluid is, in the present case, air. The use as an air compressor is the design type advantageous for the invention. The intake of the first compressor train CT1 occurs slightly below atmospheric pressure because the filter FIT arranged upstream causes a pressure loss.

(18) FIG. 2 shows a perspective illustration of a possible embodiment of the arrangement according to the invention. A filter FIT is arranged in a filter housing upstream of the first compressor train CT1. The first compressor train CT1 is integrated in the connecting fluid line CFC, which extends substantially from the filter FIT to the second compressor train CT2. Possible embodiments of such a first compressor CO1 or of the first compressor train CT1 are illustrated in FIGS. 3, 4 and 5. Illustrated downstream of the connecting fluid line CFC is a second compressor CO2, in the form of a geared compressor, of the second compressor train CT2. The second gearing of the geared compressor is denoted GR2, wherein the second gearing has, for each individual compressor stage, dedicated gearing components which are not individually designated here. The type of construction of said geared compressor corresponds to the above-described basic design of geared compressors. According to the invention, the second compressor is designed as a geared compressor. The second drive DR2 of the second compressor train CT2 is situated downstream of the second compressor CO2 in an axial elongation of the flow of the process fluid PF through the connecting fluid line CFC. The first drive DR1 of the first compressor train CT1 is integrated, in a manner which is not shown, in the connecting fluid line CFC.

(19) Such a type of construction of the integrated form of the first compressor train CT1 is illustrated in FIG. 3. Downstream of a filter FIT, the process fluid PF is raised to a higher pressure level by the first compressor train CT1, wherein both the first compressor CO1 and the first drive DR1 are integrated in the connecting fluid line CFC between the filter FIT and the downstream second compressor train CT2, which is not illustrated in any more detail. Here, the first compressor CO1 is in the form of an axial compressor. The two illustrated compressor stages CO11, CO12 of the first compressor CO1 may in this case be driven in opposite directions, with guide blades being omitted, wherein corresponding gearing measures for the drive are not illustrated here. The first drive DR1 may also be situated radially outside said axial blade arrangement. For the integral form of the first compressor CO1 in an elongation of the connecting fluid line or as an integral constituent part of the connecting fluid line CFC, the embodiment of the first compressor as an axial compressor is advantageous. An alternative embodiment of an axial compressor as first compressor CO1 is shown in FIG. 4, in which four compressor stages CO11, CO12, CO13, CO14 are arranged axially in series, in relation to an axis of rotation X which extends along the main flow direction of the process fluid PF. Said axis of rotation X is also depicted in FIG. 3. Whereas, in FIG. 3, the first drive DR1 is situated on one axial side of the overall first compressor CO1, it is the case in FIG. 4 that the first drive DR1 is arranged axially between compressor stages CO11 to CO14 situated upstream and downstream. This axial sequence has the advantage that the axis of the rotor does not project particularly far out of the drive DR1 and, in this way, the bearing arrangement within the motor is sufficient to control the rotor dynamics of the overall arrangement of the first compressor. FIGS. 7 and 8 show similar views with regard to the embodiment of the first compressor train CT1 or of the first compressor CO1 as a radial compressor.

(20) Special modularity of the first compressor train CT1 is shown in FIG. 5. Here, the connecting fluid line CFC has been sectioned perpendicular to the axis X, and the individual compressor stages CO11 to CO14 are schematically shown. The cross section of the connecting fluid line CFC is divided into four segments, wherein one compressor stage CO11 to CO14 is arranged in each segment, such that a parallel rather than a series compressor stage arrangement is realized. In this way, relatively small blowers can be used adjacent to one another in order to precompress the process fluid PF before it enters the second compressor CO2.

(21) FIG. 6 shows a schematic illustration of an arrangement according to the invention, wherein the first compressor CO1 of the first compressor train CT1 is in the form of a radial blower and compresses air, which has been taken in atmospherically, before said air enters the filter FIT. Here, the filter FIT and the first compressor CO1 are arranged outside a machine case for the second compressor train CT2, or on the outside of a case wall BW of the machine case MH. Here, the housing of the filter FIT is charged with an outlet pressure which is higher than the atmospheric pressure, and said housing must therefore be designed to be stronger than in the case of a situation with atmospheric intake. This is of significance in particular in the case of retrofitting of the first compressor train CT1, because it may be necessary for the entire filter FIT to be replaced with a strengthened model.

(22) FIGS. 7 and 8 show a possible embodiment of the first compressor CO1 as illustrated in FIG. 6. Here, similarly to the axial compressors of FIGS. 3 and 4, it is the case in FIG. 7 that the first drive DR1 is arranged axially adjacent to the compressor stages CO11, CO11, and in FIG. 8, the first drive DR1 is situated axially between the two compressor stages CO11, CO11. The difference in relation to the illustration of FIGS. 3 and 4 of the axial compressor lies substantially in the fact that the intake by the radial blower embodiment of FIGS. 7 and 8 occurs axially and the discharge thereof occurs radially, and in the fact that the radial compressor stages operate not in series with one another but in parallel.

(23) FIGS. 9, 10, 11 and 12 are concerned with a surging protection device PPC for the arrangement. FIG. 9 shows the first compressor CO1 as a radial blower in an arrangement upstream of the filter FIT. The connecting fluid line CFC situated downstream is equipped with the surging protection device PPC. The surging protection device PPC is a pressure relief device PRL, wherein spring-preloaded flaps open in the presence of positive pressure in the connecting fluid line CFC. In this way, the radial blower of the first compressor CO1 is protected against surging shocks on the second compressor CO2 (not illustrated) situated downstream.

(24) FIG. 10 shows a closing device BLO which may be provided in the connecting fluid line CFC in order to protect the first compressor CO1 against surging shocks from the second compressor CO2. Said closing device BLO may basically be a constituent part of any surging protection device PPC, or else may otherwise be provided as a non-return flap for preventing backflows. The closing device BLO is depicted, on the left in FIG. 10, in a view in an axial direction along an axis X. Here, the axis X corresponds to the main flow direction of the process fluid PF. The closing device BLO comprises multiple flaps which are arranged adjacent to one another in the manner of lamellae and which can close the flow cross section of the connecting fluid line CFC over at least 80% of the area. Here, a complete sealing action is not sought here, it rather being the intention for large pressure differences from pressure shocks to be prevented or shielded. In the action sequence depicted to the right of the cross-sectional illustration, multiple flaps FLPviewed in the direction of their rotary spindles perpendicular to the main flow directionare initially arranged adjacent to one another in an open position. A process fluid PF flows along the normal flow direction. In the event of a reversal of the flow directionthat is to say in the case of a backflowof the process fluid PF, it is firstly the case that the central pair of flaps FLP closes as a result of the aerodynamic design of the flaps, in which the backflow becomes caught and thereby pushes the flaps FLP closed. Similarly to a domino effect, the adjacent flaps are also sequentially pivoted closed as a result of the pivoting-closed and/or the flow diversion of the flaps FLP that are pivoted closed first. In this way, in the fourth image of the sequential illustration, the entire closing device BLO is situated in a closed position. The flaps FLP are advantageously equipped with a damping arrangement which operates in one direction, such that surging shocks do not result in permanent opening and closing of the closing device BLO. The damped movement direction is in this case advantageously the movement into the open position.

(25) FIGS. 11 and 12 show the embodiment of a surging protection device PPC which combines a closing device BLO and a pressure relief device PRL with one another. Here, in FIG. 11, the surging protection device PPC is situated in a normal open operating position, and in FIG. 12, said surging protection device PPC is situated in an operating position which is closed for the normal flow of the process fluid PF. Here, the connecting fluid line CFC is equipped with a slide valve SLV which is axially displaceable in the direction of an axis X. Said slide valve SLV is a constituent part of the pressure relief device PRL. Fixedly connected to the slide valve SLV is the closing device BLO, which, in the presence of an axial backflow of the process fluid PF, closes the flow cross section of the connecting fluid line CFC over at least 80% of the area. Counter to the force of a restoring spring EEL and of a damper DMP, the differential pressure of the process fluid PF across the closing device BLO, which seeks to flow backward, drives the slide valve SLV into an axial position in which a radial outlet of the pressure relief device PRL is open both upstream and downstream of the closing device BLO, such that the process fluid PF is relieved of pressure. In this way, the first compressor train CT1 and the second compressor train CT2 are protected, both upstream and downstream of the surging protection device PPC, against surging shocks.