JP2019509419A - Compressor train startup using variable inlet guide vanes. - Google Patents

Abstract

A method for operating a compressor train start is disclosed. The row includes a drive machine (30) and at least one centrifugal compressor (1) drivingly coupled to the drive machine. The centrifugal compressor (1) has at least a first at the inlet of the plurality of compressor stages (3, 5, 7, 9, 11) and the compressor stages (3, 5, 7, 9, 11). A set of variable inlet guide vanes (17). The method initiates the rotation of the centrifugal compressor when the first set of variable inlet guide vanes is at least partially closed and when the first set of variable inlet guide vanes is at least partially closed. Accelerating the centrifugal compressor to a minimum operating speed and opening at least one set of variable inlet guide vanes to increase gas flow through the centrifugal compressor when the minimum operating speed is achieved. .
[Selection] Figure 26

Description

  The present disclosure relates to a centrifugal compressor train including one or more centrifugal compressors and a drive machine. Embodiments disclosed herein relate to a method and system for operating a start of a centrifugal compressor train.

  Centrifugal compressors are used in several industrial applications to increase the pressure of process gas. For example, in the field of oil and gas, centrifugal compressors are used to process refrigerant fluid in natural gas liquefaction plants (LNG plants). Refrigerant fluids such as mixed refrigerants and propane are used in such plants to remove heat from natural gas streams extracted from gas fields and to cool and liquefy natural gas for transportation purposes. The centrifugal compressor is driven by a drive that can include, for example, an electric motor or a gas turbine engine.

  Single shaft gas turbine engines operating with semi-fixed speed and fixed speed electric motors have problems when the torque capacity is reduced at start-up and the centrifugal compressor train must be started after stopping from a pressurized condition. The starting suction density can be much higher than the nominal suction density and can also cause starting problems when using variable speed drives such as aviation-derived gas turbine engines, steam turbines, variable speed electric motors, etc. There is. In such a situation, even if the drive has a nominal torque capability from low speed, the starting torque can be higher than the nominal torque, which can cause the starting sequence to fail.

  In order to limit the torque required to start the turbomachine, the fluid circuit of which the centrifugal compressor train forms a part must be emptied or the amount of fluid in it must be reduced. Emptying the fluid circuit and subsequently refilling the fluid circuit is a time consuming and expensive operation.

  Thus, there is a need for improvements in plants and systems that include centrifugal compressors that are aimed at alleviating or solving the shortcomings of state of the art systems, particularly those that occur during start-up.

US Patent Application Publication No. 2014/000272

According to a first aspect, a method for operating a start of a compressor train is disclosed herein. The compressor train includes a drive machine and at least one centrifugal compressor drivingly coupled to the drive machine. The centrifugal compressor is a further machine and not part of the drive machine. The centrifugal compressor includes a plurality of compressor stages and at least a first set of variable inlet guide vanes (hereinafter abbreviated IGV) at one inlet of the compressor stages. This method
At least partially closing the first set of variable inlet guide vanes;
Initiating rotation of the centrifugal compressor while the variable inlet guide vane is at least partially closed, accelerating the centrifugal compressor to a minimum operating speed;
Opening at least one set of variable inlet guide vanes to increase gas flow through the centrifugal compressor when a minimum operating speed is achieved.

  According to some embodiments, the minimum operating speed may be the minimum allowable speed of the machine. The minimum permissible speed can be defined according to the API 617 “Oil, Chemical and Gas Industry Services Axial and Centrifugal and Expander Compressor” standards. The API 617 standard defines the minimum allowable speed as the minimum speed (rpm) that the manufacturer's design allows for continuous operation.

  If the drive machine is an electric motor, the minimum operating speed may be the rated speed or the synchronous speed (ie, the speed of the electric motor's synchronization with the grid frequency).

  A partially closed inlet guide vane reduces the gas flow through the compressor and thus reduces the torque required to drive the compressor. A larger torque margin is available for accelerating the centrifugal compressor.

  The variable inlet guide vane can be located at the inlet of the most upstream of the compressor stages. In some embodiments, additional variable inlet guide vanes can be placed on the inlet side of one or more additional compressor stages. For example, the compressors are back-to-back configurations, and variable inlet guide vanes are placed back-to-back at the inlet of the first (ie, most upstream) compressor stage of each group of compressor stages. This makes the compressor configuration particularly simple and affordable.

  According to some currently preferred embodiments, the step of at least partially closing the first set of variable inlet guide vanes can be performed prior to initiating rotation of the centrifugal compressor, although other embodiments According to the above, the rotation of the compressor can be started before closing the variable inlet guide vane. These latter are closed in a timely manner so that, for example, the torque margin does not fall below an unacceptable value once rotation has begun and a steady state rotational speed has been reached.

  In some embodiments, the drive machine includes a single shaft gas turbine engine and a starter. During the step of starting the rotation of the centrifugal compressor and accelerating the centrifugal compressor, power generated by the starter is supplied to the centrifugal compressor via a single shaft of the gas turbine engine.

  According to a further aspect, a gas compressor row is disclosed herein, wherein the gas compressor row is a plurality of compressors, a compressor outlet, and a plurality of gas turbine rows sequentially disposed between the compressor inlet and the compressor outlet. And a centrifugal compressor comprising at least a first set of variable inlet guide vanes at an inlet of one of the compressor stages. The compressor train includes a drive machine drivingly coupled to the centrifugal compressor, and a controller configured and arranged to at least partially close the set of variable inlet guide vanes during the startup and acceleration steps of the centrifugal compressor; Further included.

  Features and embodiments are disclosed herein below and are further described in the appended claims. The appended claims form an integral part of the specification. The foregoing brief description is intended to provide a better understanding of the following detailed description, and to further evaluate the contribution of the present invention to the art, to characterize various embodiments of the present invention. It is described. There are, of course, other features of the invention, which are described below and set forth in the appended claims. In this regard, before describing some embodiments of the present invention in detail, various embodiments of the present invention, in their application, will be described in the following description or shown in the details of construction shown in the drawings and It should be understood that the arrangement of components is not limited. The invention is capable of other embodiments and of being practiced and carried out in various ways. It should also be understood that the expressions and terms used herein are for purposes of explanation and should not be considered limiting.

  Thus, one of ordinary skill in the art can readily utilize the concepts on which the present disclosure is based as a basis for designing other structures, methods, and / or systems for carrying out some objectives of the present invention. You will understand that you can. It is important, therefore, that the claims be regarded as including such equivalent constructions insofar as they do not depart from the spirit and scope of the present invention.

  A more complete evaluation of the disclosed embodiments of the present invention and many of the attendant advantages of the present invention will be better understood by reference to the following detailed description taken in conjunction with the accompanying drawings.

1 is a schematic diagram of a multi-stage centrifugal compressor system according to embodiments described herein. FIG. FIG. 2 is a diagram showing the head curve of the compressor stage of FIG. 1, showing the change in head of the compressor stage relative to the process gas flow at start-up when the IGV is fully open. FIG. 2 is a diagram showing the head curve of the compressor stage of FIG. 1, showing the change in head of the compressor stage relative to the process gas flow at start-up when the IGV is fully open. FIG. 2 is a diagram showing the head curve of the compressor stage of FIG. 1, showing the change in head of the compressor stage relative to the process gas flow at start-up when the IGV is fully open. FIG. 2 is a diagram showing the head curve of the compressor stage of FIG. 1, showing the change in head of the compressor stage relative to the process gas flow at start-up when the IGV is fully open. FIG. 2 is a diagram showing the head curve of the compressor stage of FIG. 1, showing the change in head of the compressor stage relative to the process gas flow at start-up when the IGV is fully open. FIG. 2 shows pressure versus time at start-up of the compressor system of FIG. 1 operating with a fully open IGV. It is a figure which shows the torque margin and fluid torque of the compressor system which operate | moves on the conditions of FIGS. It is a figure which shows the torque margin and fluid torque of the compressor system which operate | moves on the conditions of FIGS. FIG. 10 shows the same curves of FIGS. 2 to 9 when the compressor system operates with a partially closed IGV at start-up. FIG. 10 shows the same curves of FIGS. 2 to 9 when the compressor system operates with a partially closed IGV at start-up. FIG. 10 shows the same curves of FIGS. 2 to 9 when the compressor system operates with a partially closed IGV at start-up. FIG. 10 shows the same curves of FIGS. 2 to 9 when the compressor system operates with a partially closed IGV at start-up. FIG. 10 shows the same curves of FIGS. 2 to 9 when the compressor system operates with a partially closed IGV at start-up. FIG. 10 shows the same curves of FIGS. 2 to 9 when the compressor system operates with a partially closed IGV at start-up. FIG. 10 shows the same curves of FIGS. 2 to 9 when the compressor system operates with a partially closed IGV at start-up. FIG. 10 shows the same curves of FIGS. 2 to 9 when the compressor system operates with a partially closed IGV at start-up. FIG. 10 shows the same view of FIGS. 2 to 9 when the compressor system operates with gas bleed from the second stage to the first stage with the IGV partially closed at start-up. FIG. 10 shows the same view of FIGS. 2 to 9 when the compressor system operates with gas bleed from the second stage to the first stage with the IGV partially closed at start-up. FIG. 10 shows the same view of FIGS. 2 to 9 when the compressor system operates with gas bleed from the second stage to the first stage with the IGV partially closed at start-up. FIG. 10 shows the same view of FIGS. 2 to 9 when the compressor system operates with gas bleed from the second stage to the first stage with the IGV partially closed at start-up. FIG. 10 shows the same view of FIGS. 2 to 9 when the compressor system operates with gas bleed from the second stage to the first stage with the IGV partially closed at start-up. FIG. 10 shows the same view of FIGS. 2 to 9 when the compressor system operates with gas bleed from the second stage to the first stage with the IGV partially closed at start-up. FIG. 10 shows the same view of FIGS. 2 to 9 when the compressor system operates with gas bleed from the second stage to the first stage with the IGV partially closed at start-up. FIG. 10 shows the same view of FIGS. 2 to 9 when the compressor system operates with gas bleed from the second stage to the first stage with the IGV partially closed at start-up. FIG. 3 is a schematic diagram of a further embodiment of a multi-stage centrifugal compressor system according to the present disclosure. FIG. 3 illustrates an exemplary embodiment of a centrifugal compressor train of an LNG plant that includes a drive machine portion according to one embodiment.

  In the following detailed description of the exemplary embodiments, reference is made to the accompanying drawings. The same reference numbers in different drawings identify the same or similar elements. Further, the drawings are not necessarily drawn to scale. Also, the following detailed description does not limit the invention. Instead, the scope of the invention is defined by the appended claims.

  Throughout this specification, references to “one embodiment”, “embodiments” or “some embodiments” refer to particular features, structures, or characteristics described in connection with certain embodiments. In at least one embodiment. Thus, the phrases “in one embodiment” or “in one embodiment” or “in some embodiments” appearing in various places throughout this specification are not necessarily referring to the same embodiment. Furthermore, the particular features, structures or characteristics may be combined in any suitable manner in one or more embodiments.

  FIG. 1 schematically shows a multistage centrifugal compressor 1 comprising a plurality of stages 3, 5, 7, 9, 11. For the sake of clarity, each stage of the compressor 1 is shown as a separate unit. However, it is understood that the compressor stages 3-11 can be arranged in the same compressor casing having a compressor suction side (or compressor inlet) 13 and a compressor discharge side (or compressor outlet) 15. I want. Although not shown in FIG. 1, the multistage centrifugal compressor 1 can be rotationally driven by a driving device. The drive machine can include an electric motor. In some embodiments, a variable speed connection, such as a variable speed planetary gear, can be placed between the fixed speed electric motor and the compressor 1.

  In other embodiments, the drive machine may include a gas turbine engine. In some exemplary embodiments, the drive machine includes a single shaft gas turbine engine. In combination with the gas turbine engine, the drive machine can include a starter, such as an electric machine, that operates as a motor to start the compressor train.

  The multistage centrifugal compressor 1 may be one of a plurality of refrigerant compressors of the LNG plant. For example, the multistage centrifugal compressor 1 may be a mixed refrigerant compressor or a propane compressor. The multistage centrifugal compressor 1 compresses the refrigerant fluid from the suction pressure to the discharge pressure and circulates in the closed refrigerant circuit. The compressed refrigerant fluid is then expanded in an expander or expansion valve device, causing the temperature to drop. The cooled expanded refrigerant fluid is placed in a heat exchange relationship with a natural gas stream that is cooled and liquefied to remove heat from the natural gas stream, and then processed again by the multi-stage centrifugal compressor 1. It is cooled by heat exchange with a heat sink.

  One, some or all of the centrifugal compressor stages 3-9 can be provided with variable inlet guide vanes. In the schematic embodiment of FIG. 1, a variable inlet guide vane (IGV) is shown at the inlet of the first centrifugal compressor stage 3 and is shown schematically at 17.

  One or more bleed lines or bypass lines may be provided that fluidly connect the discharge side of one compressor stage to the suction side of another upstream compressor stage. In the exemplary embodiment of FIG. 1, a bleed line 19 is shown that fluidly couples the discharge side of the compressor stage 5 to the suction side 13 of the compressor, ie the suction side of the first compressor stage 3. A bleed valve 20 can be disposed on the bleed line 19 to control the amount of bleed process gas flowing through the bleed line 19.

  By acting on the variable inlet guide vane 17, the operating conditions of the multistage centrifugal compressor 1 can be controlled. These latter can act, for example, to change the gas flow rate through the multistage centrifugal compressor 1.

  2-6 show the compressor curve profiles of five stages 3-11 when the multistage centrifugal compressor 1 operates with the fully open IGV 17. Each of FIGS. 2 to 6 shows a head versus flow curve for each of the five stages of the multistage centrifugal compressor 1. FIG. 7 shows the multistage centrifugal compressor 1 under the same operating conditions at start-up when the fluid circuit in which the multistage centrifugal compressor 1 forms part of the fluid circuit is filled with process gas. The suction side pressure and the discharge side pressure are shown as a function of time. The multistage centrifugal compressor 1 starts at time t = 0.

  FIG. 8 shows the torque margin (%) as a function of compressor speed starting from zero speed. Torque margin is the percentage of available torque from the drive machine. For proper operation of the compressor train at start-up, the torque margin must be greater than zero to ensure acceleration of the compressor train according to the drive machine speed schedule required by the drive machine manufacturer.

  FIG. 9 shows fluid torque versus compressor speed for five compressor stages 3-11. Curves T3, T5, T7, T9 and T11 represent the torque absorbed by steps 3, 5, 7, 9, and 11, respectively.

  As can be seen from FIG. 8, when the multistage centrifugal compressor 1 is started with a fully opened IGV and a fully filled compressor circuit, the torque margin is below zero at a given compressor speed. descend. Therefore, starting the multi-stage centrifugal compressor 1 requires at least partially emptying the compressor circuit before starting. Alternatively, an oversized drive machine must be used to provide sufficient torque at start-up. Alternatively, other devices such as an inlet throttling valve (located in the antisurge loop) can be taken into account to reduce the absorbed torque when starting the compressor. If the drive machine is an electric motor, an oversized electric motor with an output rate that exceeds the output rate required to drive the compressor train under steady-state conditions to handle large torque demands at start-up A motor is required.

  If the drive machine includes a single shaft gas turbine engine, a separate starter such as an electric motor or a steam turbine is required to start the multi-stage centrifugal compressor 1. In such a case, the rated output of the starter must be dimensioned so that sufficient torque is obtained at start-up. Starter costs and dimensions are very high. In addition, the high power rate supplied by the starter cannot be transmitted through the shaft of the gas turbine engine, so the starter must be placed at the end of the compressor line shaft line on the opposite side of the gas turbine engine. I must. This creates drawbacks in terms of accessibility to the turbomachine and causes problems during the maintenance of the centrifugal compressors in the compressor train.

  In accordance with some embodiments of the presently disclosed subject matter, a multi-stage centrifugal compressor is used to reduce torque margin degradation and thus address the torque and power required at start-up with lower performance starters. One variable IGV 17 is at least partially closed during start-up. This reduces the process gas flow across the multi-stage centrifugal compressor 1 and, as a result, reduces the torque required to rotate the multi-stage centrifugal compressor 1.

  FIGS. 10 to 17 show the same views as FIGS. 2 to 9 when starting the multistage centrifugal compressor 1 with the partially closed IGV 17. Because the IGV 17 is located at the inlet of the first compressor stage 3, the head curve of the first stage 3 (FIG. 10) is maximized for a given process fluid flow and then decreases.

  As for torque margin, this is reflected in the minimum torque margin (see FIG. 16) at a given compressor speed, and then the torque margin increases, so in this example the torque margin drops below about 14%. There is no. Mass flow across the compressor stage is substantially reduced.

  FIG. 17 shows the torque absorbed by each of the five stages 3 to 11 of the multistage centrifugal compressor 1. By closing the variable IGV 17, the torque absorbed by the first stage 3 decreases relative to the torque absorbed under the operating conditions shown in FIG. 9, and reaches a maximum at a given compressor speed. When the compressor speed value is exceeded, the torque decreases and the torque margin increases (see FIG. 16). It should be noted that the absolute torque after the second stage also decreases due to the lower gas density downstream of the first stage.

  A further advantage with respect to torque reduction can be achieved by extracting a portion of the process gas returning from one of the compressor stages to the suction side of the upstream compressor stage. In the embodiment of FIG. 1, the bleed line 19 is arranged between the discharge side of the second compressor stage 5 and the suction side of the first compressor stage 3. By extracting the percentage of the process gas flow from the discharge side of the compressor stage 5 to the suction side of the first compressor stage 3, the head curve of the first compressor stage 3 is further increased by increasing the flow rate. The total torque absorbed by the multistage centrifugal compressor 1 decreases.

  18-25 show the same view as FIGS. 10-17 with additional process gas bleed. As can be seen in particular by comparing FIGS. 24 and 25 with FIGS. 16 and 17, the torque margin in this case does not fall below 20% and the torque absorbed by the first stage 3 can be zero. .

  Torque reduction at start-up is achieved by reducing the process fluid flow acting on the variable IGV 17. In the presently preferred embodiment, the variable IGV 17 is closed before starting the rotation of the multistage centrifugal compressor 1. However, this is not strictly necessary. Actually, as shown in the head curves of FIGS. 2, 10, 18, 18, 8, 16, and 24, when the multistage centrifugal compressor 1 is started, the head gradually increases and the torque margin gradually decreases. Therefore, it is possible to start the starting procedure with the fully opened IGV 17 and gradually close the IGV 17 to limit the head increase and the torque margin decrease.

  The variable IGV 17 can be opened again when the multistage centrifugal compressor 1 reaches a minimum operating speed. In the case of a turbomachine train operating at a fixed or semi-fixed speed, the minimum operating speed may be the rated speed of the drive machine. In some embodiments, the minimum operating speed can be set as the minimum allowable speed under the API 617 standard (see API 617 standard, 2002 edition, paragraph 1.5.22).

  FIG. 26 shows a further exemplary embodiment of the multistage centrifugal compressor 1. The schematic diagram of FIG. 26 shows a drive machine 30 that can be comprised of an electric motor and / or a gas turbine engine, preferably a single shaft gas turbine engine.

  In the illustrated embodiment, the multi-stage centrifugal compressor 1 includes a first set of compressor stages 31 and a second set of compressor stages 33 in a back-to-back arrangement. The gas flow in the first set of compressor stages 31 is generally in the direction of arrow F31, and the gas flow in the second set of compressor stages 33 is generally in the direction of arrow F33. The discharge side of the first set of the most downstream compressor stages 31 is fluidly coupled to the suction side of the second set of the most upstream compressor stages 33.

  In some embodiments, a first set of variable inlet guide vanes 17 is located on the suction side of the multi-stage centrifugal compressor 1 and a second set of variable inlet guide vanes 18 is a second set of compressor stages 33. Is arranged on the suction side of the most upstream compressor stage. One or both of the variable inlet guide vanes 17 and 18 can be controlled to reduce the process gas flow at start-up, and the total torque required for the start-up rotation of the multi-stage centrifugal compressor 1 can be reduced.

  In some embodiments, as shown in FIG. 26, a side stream in fluid communication with the intermediate compressor stage can be provided. The arrangement of the side flow is common in refrigerant compressors for LNG applications. In the schematic of FIG. 26, the main process fluid stream enters the suction side 13 of the multi-stage centrifugal compressor 1 and side streams 34, 35, 37 are provided in fluid communication with the intermediate compressor stage. Sidestreams 34 and 35 are fluidly coupled to the stages of the first set of compressor stages 31 and sidestreams 37 are fluidly coupled to the suction side of the upstream stage of the second set of compressor stages 33. Is done. Accordingly, the third side stream 37 merges with the partially compressed process fluid flowing from the outlet 39 of the first set of compressor stages 31 to the inlet 41 of the second set of compressor stages 33. Thus, a second set of variable inlet guide vanes 18 can be used to regulate the flow through the side flow.

  A reduction in output obtained at the start of the multistage centrifugal compressor 1 may reduce the rated output of the electric motor that drives the multistage centrifugal compressor 1, or may reduce the rated output. The starter and the rated output of the starter used in combination with a prime mover such as a gas turbine engine that forms part of the drive machine may be reduced.

  The lower power rate results in a smaller and less expensive machine, but provides additional advantages, more clearly with reference to the configuration of FIG. 27 showing further embodiments of the centrifugal compressor arrangement and associated drive machine Become.

  The system of FIG. 27 includes, as an example, a compressor row 2 that includes a first multistage centrifugal compressor 1A and a second multistage centrifugal compressor 1B, both driven by a drive machine 30. Two multistage centrifugal compressors 1A, 1B can be used to process the same or different process gases. For example, the compressor row 2 can be part of an LNG refrigeration circuit. In some embodiments, the first multi-stage centrifugal compressor 1A can be configured to process propane, and the second multi-stage centrifugal compressor 1B can be configured to process a mixed refrigerant. In other embodiments, the two multi-stage centrifugal compressors 1A, 1B may be any number selected from the group consisting of, for example, methane, ethane, propane, ethylene, nitrogen, ammonia, butane, isobutene, propylene, and combinations thereof. Any one of the possible refrigerant fluids can be processed. Broadly speaking, gases belonging to the standard refrigerant designation of ASHRAE (American Heating, Refrigeration and Air Conditioning Engineers Association) can be used.

  The multistage centrifugal compressors 1A and 1B may be vertically divided compressors, or both horizontally divided compressors. For example, the compressors 1A and 1B may both be MCL series compressors, and both may be BCL series compressors. If one of the two compressors is a vertically divided compressor, such as a BCL series compressor, in some preferred configurations, the vertically divided compressor is: It is arranged at the end of the compressor row 2, that is, on the opposite side of the drive machine 30.

  The drive machine 30 can be composed of a gas turbine engine 43. For example, the gas turbine engine 43 may include a single shaft gas turbine engine 43. The gas turbine engine 43 may include an air compressor unit 45, a combustor unit 47, and a turbine unit 49. The power generated by the turbine unit 49 drives the air compressor unit 45 and the compressor train 2.

  Reference numeral 51 schematically represents a single shaft of the gas turbine engine 43. The shaft 51 has a first shaft end 51 </ b> A on the suction side of the gas turbine engine 43, i.e., on the low temperature side, and a second shaft end 51 </ b> B on the pressure side of the gas turbine engine 43, i.e., on the high temperature side. In contrast to the commonly used configuration of the current technology where an electric starter is located at the end of the compressor train 2 opposite the gas turbine engine 43, the disclosed configuration operates as a starter. An electric machine 53 is drivingly connected to the first end 51 </ b> A of the shaft 51. The electric machine 53 may be a reversible electric machine that can selectively operate in a generator mode or a motor mode. Thus, the electric machine 53 can operate as a starter, a helper, or a generator when operating in the electric motor mode. The second end 51 </ b> B of the shaft 51 is drivingly connected to the compressor row 2.

  The same drive machine 30 can be used in combination with the configuration of FIGS.

  By operating the IGVs 17 and / or 18 of one or more multi-stage centrifugal compressors 1A, 1B at start-up, the gas flow rate through the gas compressor train 2 at start-up is reduced. In order to start the compressor train, less power is required compared to centrifugal compressor trains of the current technology. Thus, the total output rate of the electric machine 53 can be lower than that in the current technology plant configuration.

  Thus, the electric machine 53 is connected to the gas turbine engine 43 on the opposite side of the compressor row 2 thanks to the reduced mechanical power that needs to be transmitted across the gas turbine engine 43 via a single shaft 51. Can be placed on the side.

  By arranging the starter on the opposite side of the compressor row 2 of the gas turbine engine 43, maintenance of the compressor row is facilitated. In particular, the opening of the multistage centrifugal compressor 1B divided in the vertical direction and access to the inside thereof are not important, and can be obtained without disassembling the line shaft.

  Although the embodiments described above are specifically referred to LNG applications, the innovative features disclosed herein can be implemented in other systems where similar problems occur when starting the compressor. .

  Furthermore, while the above description refers specifically to a drive machine that includes a single shaft gas turbine, the use of a variable IGV during start-up also provides advantages when the drive machine includes an electric motor. If less power is consumed at start-up, the rated output, size, and hence cost, of the electric motor can be reduced.

  While the disclosed embodiments of the subject matter described in this specification have been illustrated in the drawings and have been fully described above in particular and detail in connection with certain exemplary embodiments, many modifications, Those skilled in the art will recognize that changes and omissions may be made without departing significantly from the new teachings, principles and concepts described herein, and the advantages of the subject matter recited in the appended claims. It will be clear. Accordingly, the proper scope of disclosed innovations should only be determined by interpreting the appended claims in the broadest sense so as to include all such modifications, changes and omissions. In addition, the order or sequence of any methods or method steps may be changed or re-ordered according to alternative embodiments.

1 Multistage Centrifugal Compressor 1A First Multistage Centrifugal Compressor 1B Second Multistage Centrifugal Compressor 2 Compressor Rows 3, 5, 9, 7, 11 Compressor Stage 13 Suction Side 17 Variable Inlet Guide Vane 18 Variable Inlet Guide Vane 19 Extraction line 20 Extraction valve 30 Drive machine 31 First set of compressor stages 33 Second set of compressor stages 34, 35, 37 Side flow 39 Outlet 41 Inlet 43 Gas turbine engine 45 Air compressor section 47 Combustor Part 49 turbine part 51 shaft 51A first shaft end 51B second shaft end 53 electric machine

Claims (19)

A method for operating a start of a compressor train (2) comprising a drive machine (30) and at least one centrifugal compressor (1) drivingly coupled to the drive machine (30), comprising: The centrifugal compressor (1) includes a plurality of compressor stages and at least a first set of variable inlet guide vanes (17) at one inlet of the compressor stages, the method comprising:
At least partially closing said first set of variable inlet guide vanes (17);
While the first set of variable inlet guide vanes (17) is at least partially closed, the centrifugal compressor (1) begins to rotate and accelerates the centrifugal compressor (1) to a minimum operating speed. Step to
Opening the first set of variable inlet guide vanes (17) to increase gas flow through the centrifugal compressor (1) when the minimum operating speed is achieved.   The method of claim 1, wherein the first set of variable inlet guide vanes (17) is disposed at the inlet of the most upstream compressor stage of the centrifugal compressor (1).   The drive machine (30) includes a single-shaft gas turbine engine (43) and a starter, and starts the rotation of the centrifugal compressor (1) to accelerate the centrifugal compressor (1). The method according to claim 1 or 2, wherein the power generated by the starter is supplied to the centrifugal compressor (1).   The method of claim 3, wherein the starter is one of an electric motor and a steam turbine.   The starter is drivingly connected to a first end of the single shaft gas turbine engine (43), and the centrifugal compressor (1) is driven to a second end of the single shaft gas turbine engine (43). The method according to claim 3 or 4, wherein the methods are linked.   During at least part of the steps of extracting gas from the discharge side of one of the compressor stages and starting the rotation of the centrifugal compressor (1) and accelerating the centrifugal compressor (1) Returning the bleed gas to an upstream compressor stage inlet on the discharge side.   During at least part of the step of initiating rotation of the centrifugal compressor (1) and accelerating the centrifugal compressor (1), an intermediate one of the plurality of compressor stages or the most downstream The method according to one or more of the preceding claims, further comprising at least partly closing a second set of variable inlet guide vanes (18) arranged upstream one.   A gas side stream is fed to an intermediate one of the compressor stages between the first set of variable inlet guide vanes (17) and the second set of variable inlet guide vanes (18). The method of claim 7, further comprising a step.   The first set of variable inlet guide vanes (17) and the second set of variable inlet guide vanes (18) are arranged at the inlets of respective compressor stages arranged in a back-to-back configuration. Item 9. The method according to Item 7 or 8. A gas compressor train (2),
A compressor inlet, a compressor outlet, a plurality of compressor stages sequentially disposed between the compressor inlet and the compressor outlet, and at least a first set at one inlet of the compressor stages; A variable inlet guide vane (17), and a centrifugal compressor (1) comprising:
A drive machine (30) drivingly connected to the centrifugal compressor (1);
A gas compressor train (2) comprising: a controller configured and arranged to at least partially close the set of variable inlet guide vanes during startup and acceleration steps of the centrifugal compressor (1).   The gas compressor train (2) according to claim 10, wherein the first set of variable inlet guide vanes (17) is arranged at the inlet of the most upstream compressor stage of the centrifugal compressor (1). .   The gas according to claim 10 or 11, wherein the drive machine (30) comprises a single shaft gas turbine engine (43) and a starter, the starter being drivingly connected to the single shaft gas turbine engine (43). Compressor train (2).   The gas compressor train (2) according to claim 12, wherein the starter is one of an electric motor and a steam turbine.   The starter is drivingly connected to a first end of the single shaft gas turbine engine (43), and the centrifugal compressor (1) is driven to a second end of the single shaft gas turbine engine (43). Gas compressor train (2) according to claim 12 or 13, which is connected.   15. Gas compression according to one or more of claims 10 to 14, further comprising a bleed line disposed between the discharge side of one of the compressor stages and the inlet of one of the compressor stages. Machine train (2).   The gas compressor row (2) according to claim 15, wherein an outlet of the bleed line is connected to an inlet of an upstream stage of the compressor stage.   The controller further includes a second set of variable inlet guide vanes (18) disposed upstream of one of the plurality of compressor stages or one of the most downstream, wherein the controller is configured to perform the starting and accelerating steps. The gas compressor row (2) according to one or more of the claims 10 to 15, wherein the gas compressor row (2) is constructed and arranged to at least partly close the second set of variable inlet guide vanes (18).   The centrifugal compressor (1) comprises a first set of compressor stages (31) and a second set of compressor stages (33) arranged downstream of the first set of compressor stages (31). ), And the first set of compressor stages (31) and the second set of compressor stages (33) each include at least one compressor stage, and the first set of compression stages The machine stage (31) and the second set of compressor stages (33) are arranged in a back-to-back configuration, and the second set of variable inlet guide vanes (18) are arranged in the second set of compressor stages. A gas compressor row (2) according to claim 17, arranged at the inlet of one of the compressor stages of (33).   19. A gas compressor train according to claim 17 or 18, wherein a side flow is provided between the first set of variable inlet guide vanes (17) and the second set of variable inlet guide vanes (18). (2).