Device for preventing undesirable rotation of gas turbine engine rotor

Abstract

FIELD: gas turbine engines.SUBSTANCE: invention relates to devices for preventing unwanted rotation of the rotor of a single-shaft gas turbine engine of stationary gas turbine units in non-operating modes. The device comprises a bracket with a sleeve for a pin, which is movably inserted into the sleeve, and a position sensor mounted on the bracket and configured to generate a signal to the control system about the position of the pin. The bracket is attached to the protective casing of the mechanical coupling that transmits torque from the shaft of the gas turbine engine to the shaft of the driven equipment, the sleeve is secured in a hole made in the protective casing of the mechanical coupling, the pin is designed to enter a hole made on the surface of the mechanical coupling. The end of the pin entering the hole on the surface of the mechanical coupling may have an eccentric, the end of the pin opposite the mechanical coupling may have a thickening, the diameter of which is larger than the internal diameter of the sleeve, in the middle part of the pin a radial through smooth hole may be made, and a longitudinal slot for a spring pin can be made in the sleeve. Two holes can be made along the height of the sleeve for a fastening element, and in the middle part of the pin, a thinning can be made for this fastening element, so that the upper hole in the sleeve serves to fix the position of the pin when the mechanical coupling is not locked, and the lower hole serves to secure the position of the pin when the mechanical coupling is locked. The sleeve may have stiffening ribs attached to the mechanical coupling housing. An inductive proximity switch can be used as a position sensor.EFFECT: simple, effective and safe-to-use device is provided to prevent unwanted rotation of the rotor of a single-shaft gas turbine engine in stationary gas turbine units.8 cl, 10 dwg

Description

[0001] The invention relates to the field of mechanical engineering, more specifically to stationary single-shaft gas turbine engines (hereinafter referred to as GTE) for driving an electric generator or compressor (hereinafter referred to as driven equipment), in particular to devices for preventing unwanted rotation of the GTE rotor of stationary gas turbine units in non-operating modes.

[0002] Stationary gas turbine units have air intake systems (e.g., in the form of integrated air preparation units) designed to supply treated atmospheric air to the gas turbine engine (GTE) combustion chambers for combustion. It is known that when the GTE is idle, atmospheric air entering from the air intake system can cause the rotor of the GTE's air compressor to rotate. This rotation can be transmitted through the common shaft of a single-shaft GTE to the rotor of its turbine, and through the gearbox and clutch to the shaft of the driven equipment. This unwanted rotation of the GTE rotor is called windmilling. Windmilling of the GTE reduces the service life of the GTE and can even lead to equipment failure.

[0003] To prevent autorotation during idle conditions of a gas turbine engine, the air intake system of stationary gas turbine units may have dampers that completely block the air duct. For example, similar technical solutions are known from patent documents US 4003200 (published January 18, 1977) or WO 2013131968 (published September 12, 2013). However, such solutions require complex and bulky devices and may include expensive equipment, such as electric drives. Other devices used to prevent autorotation during idle conditions of a gas turbine engine are also known in the prior art. For example, the device from patent document EP 4286704 (published 06.12.2023) contains an actuator (electric drive) designed to interact with either the shaft or the rotor of the gas turbine engine and block their rotation when the gas turbine engine is not operating, for example, by means of electromagnetic interaction or by means of a recess and a corresponding protrusion.This solution is also quite complex and also requires expensive and bulky equipment.

[0004] Any manufacturer, including those producing stationary gas turbine units for gas pumping or power generation, strives to reduce production costs. Therefore, units typically use standard equipment from subsuppliers—gearboxes, mechanical clutches, electric generators, compressors, and the like. Any custom orders from subsuppliers for specific needs increase production costs due to design complexity or increased lead times. Therefore, improvements that do not affect or require minimal design changes to subsupplier equipment and are simple, efficient, and safe are extremely beneficial.

[0005] A simple, effective, and safe propeller shaft locking device is disclosed in patent document CN 203497164 (published March 26, 2014). The device comprises a support (bracket) with a sleeve into which a cylindrical locking pin is screwed. One end of the pin is designed to engage a recess in the propeller shaft, while the other end has a rotating handle. The pin also has a travel limiter configured to engage two position sensors mounted on the support and connected to the control system, thereby ensuring the safe operation of the device. One of the sensors records the pin's position when the shaft is locked and cannot be started, while the other records the position when the shaft is unlocked and can be operated. We have accepted this technical solution as the closest equivalent. However, this device is not suitable for preventing autorotation of single-shaft gas turbine engines.

[0006] Thus, the challenge is to create a simple, effective, and safe device to prevent unwanted rotation (autorotation) of the rotor of a single-shaft gas turbine engine (GTE) in a stationary gas turbine plant. The proposed invention aims to achieve the technical result of creating such a device.

[0007] To achieve the specified technical result, a device for preventing unwanted rotation of a single-shaft gas turbine engine rotor comprises a bracket with a sleeve for a pin, which is movably inserted into the sleeve and has a travel limiter, the device also comprises a position sensor mounted on the bracket and configured to generate a signal to the control system about the position of the pin, wherein the bracket is attached to the outside of the protective casing (hereinafter referred to as the casing) of a mechanical coupling (hereinafter referred to as the coupling) transmitting torque from the gas turbine engine shaft to the shaft of the driven equipment, the sleeve is fixed in an opening made in the coupling casing, the pin is configured to enter an opening made on the surface of the coupling. In a particular case of implementing the invention, the end of the pin entering the opening on the surface of the coupling has an eccentric. In another particular case, the end of the pin opposite the coupling has a thickening serving as a travel limiter, the diameter of which is greater than the inner diameter of the sleeve.In another case, a radial through-hole for a spring pin is made in the middle of the pin, and a longitudinal slot is made in the sleeve. It is advisable to make a pair of radial through-threaded holes along the height of the sleeve for a fastener, such as a bolt, and to make a thinning in the middle of the pin for this fastener, such that the upper hole in the sleeve serves to fix the pin's position when it does not enter the hole on the coupling surface, and the lower hole serves to fix the pin's position when it does enter the hole on the coupling surface. It is advisable to design the sleeve with stiffening ribs attached to the coupling housing. It is advisable to use an inductive proximity switch as a position sensor.

[0008] The distinctive features of the proposed device from the above-mentioned known one, which is closest to it, are that the bracket is attached to the protective casing of the mechanical coupling that transmits torque from the shaft of the gas turbine engine to the shaft of the driven equipment, the sleeve is fixed in the hole made in the casing of the coupling, the pin is movably inserted into the sleeve with the ability to enter with its end into the hole made on the surface of the coupling.In particular cases of the invention implementation: the end of the pin entering the hole on the surface of the coupling has an eccentric; the end of the pin opposite to the coupling has a thickening, the diameter of which is greater than the internal diameter of the sleeve; in the middle part of the pin there is a radial through smooth hole for a spring cotter pin, and in the sleeve there is a longitudinal slot; along its height of the sleeve there is a pair of radial through threaded holes for a fastening element, for example, for a bolt, and in the middle part of the pin there is a thinning for this fastening element, so that the upper hole in the sleeve serves to fix the position of the pin, when it does not enter the blind hole on the surface of the coupling, and the lower hole serves to fix the position of the pin, when it enters the blind hole on the surface of the coupling; the sleeve is made with stiffening ribs attached to the casing of the coupling; an inductive contactless switch is used as a position sensor.

[0009] The bracket is attached to the coupling housing, which transmits torque from the gas turbine shaft to the driven equipment shaft. The sleeve is secured in a hole in the coupling housing, and the pin is movably inserted into the sleeve with its end oriented to a hole drilled on the coupling surface. This prevents the coupling from rotating around its axis when the pin end is inserted into its hole (the coupling is locked). Since the shafts of the generator, coupling, gearbox, and gas turbine are connected and form a common shaft line, the coupling lock simultaneously prevents unwanted rotation of the gas turbine rotor due to air pressure entering the rotor of the gas turbine's air compressor from the air intake system. Since minor deviations in the relative position of the hole in the coupling and the pin are possible, due to the fact that the end of the pin entering the hole on the surface of the coupling has an eccentric, contact of the pin with the hole in the coupling is guaranteed.The pin's thickened end, opposite the coupling, serves as a travel stop, with a diameter larger than the inner diameter of the sleeve. This ensures the device's safety; the pin cannot fall into the coupling housing and cause damage. A smooth, radial through-hole for a spring pin is drilled in the pin's center, and a longitudinal slot for a spring pin is made in the sleeve, allowing the pin's vertical position to be adjusted. The cotter pin and slot act as position stops, and the cotter pin head can also serve as a handle for pin manipulation. Furthermore, the cotter pin prevents the pin from being removed from the sleeve once it is inserted through the sleeve's longitudinal slot.The sleeve, along its height, contains a pair of radial through-threaded holes for a fastener, such as a bolt, and the pin's center section is recessed to accommodate this fastener. The upper hole in the sleeve serves to secure the pin when it is not engaged in the coupling surface opening (the coupling is free), while the lower hole serves to secure the pin when it is engaged in the coupling surface opening (the coupling is locked). This ensures secure pin positioning during gas turbine engine operating conditions or when unwanted rotation of the gas turbine rotor must be prevented, thereby ensuring the safety of the device. The bolt also prevents the pin from being removed from the sleeve. The sleeve's design with stiffening ribs attached to the coupling housing ensures the reliability and safety of the device.The use of a position sensor, specifically an inductive proximity switch capable of sending a pin position signal to the control system, ensures safe operation. The device is simple and requires little or no modification to standard commercial equipment, particularly the clutch. Thus, all of the above features provide a simple, effective, and safe device for preventing unwanted rotor rotation in a single-shaft gas turbine engine (GTE) of a stationary gas turbine plant.

[0010] The proposed design is illustrated by the drawings: Figure 1 shows a general view of a stationary gas turbine unit with a single-shaft GTE, gearbox and driven equipment (with a generator in the example shown) on a common frame, in axonometric projection; Figure 2 shows a general view of the proposed device in axonometric projection, one of the embodiment examples; Figure 3 is a side view of the device, Figure 4 is a top view and Figure 5 is a bottom view (the clutch casing is not shown conditionally), Figure 6 is a vertical section A-A, shown in Figure 4; Figure 7 shows a bracket in axonometric projection; Figure 8 is a pin; Figure 9 is a bushing for the pin;in figure 10 - general view of the device and the coupling (3D model), where 1 - gas turbine engine, 2 - gearbox, 3 - generator, 4 - coupling casing, 5 - device for preventing unwanted rotation of the gas turbine engine rotor, 6 - bracket, 7 - sleeve, 8 - pin, 9 - cotter pin, 10 - stiffener, 11 - eccentric, 12 - fastening element, 13 - pin thinning (8), 14 - pin thickening (8), 15 - radial through smooth hole in the pin (8) for the cotter pin (9), 16 - slot in the sleeve (7) for the cotter pin (9), 17 - radial through threaded hole in the sleeve (7) for the fastening element (12), 18 - coupling, 19 - hole on the surface of the coupling (18). The position sensor is not shown in the figures.

[0011] In a specific example of the invention embodiment shown in the figures, the gas turbine engine (1), gearbox (2) and generator (3) (together - a gas turbine power unit) are mounted on a common frame (Fig. 1). An elastic mechanical coupling (18) connects the shafts of the gearbox (2) and generator (3) (Fig. 10). The coupling has two hubs and a connecting part between them (not marked). A hole (19) is made on the cylindrical surface of the connecting part of the coupling (18). The hole (19) on the coupling (18) can be an existing hole or a hole specially bored for a pin (8). In the example shown, an existing fastening hole in the coupling (18) is used for a lifting device - an eye bolt, which is removed after the installation of the coupling (18). The coupling (18) may have several such holes (19) radially located on a common circumference. An example of such a coupling is the coupling according to patent document DE2010026813 (published 12.01.2012).The bracket (6) with the bushing (7) is welded to the casing (4) of the coupling (18) in such a way that the bushing (7) is coaxial with the opening (19) on the coupling (18) (Fig. 10). In this case, the bushing (7) passes into the opening in the casing (4) and is partially located in the cavity under the casing (4) (Fig. 6). Stiffening ribs (10) are welded to the bushing (7) and to the walls of the casing (4) on the outer and inner sides of the casing (4) (Figs. 2, 4, 5, 10). The bracket (6) is made with a platform (not marked) for placing a position sensor, in the example shown, the bracket (6) also has an opening (not marked) (Figs. 2, 7) for installing the sensitive element of the sensor, in the example shown, an inductive contactless switch is used. The sensor is installed in such a way as to record the working and non-working positions of the pin (8). Another suitable device can be used as a position sensor. A cylindrical pin (8) with an eccentric (11), a thinning (13), and a thickening (14) is inserted into the sleeve (7).In the example shown in Figure 6, the pin (8) is in the non-working position when its end with the eccentric (11) does not enter the hole of the coupling (18). The position of the pin (8) in the non-working position can be fixed by a cotter pin (9), which is inserted into the hole (15) in the pin (8) and is located above the sleeve (7), preventing the pin (8) from lowering. A vertical slot (16) is made on the sleeve (7) (Fig. 9), through which the hole (15) in the pin (8) is accessible, the cotter pin (9) can be inserted into the hole (15) and serve as a handle for the pin (8) when adjusting its position to lock the coupling (18). In addition, when the cotter pin (9) is inserted through the longitudinal slot (16), it does not allow the pin (8) to be removed from the sleeve (7). On the sleeve (7) there are two holes (17) made along the height for the fastening element (12); in the example shown, a bolt is used (Fig. 4), another suitable fastening element can be used.Bolt (12) is used to fix pin (8) in sleeve (7) in two positions: to fix in the position when coupling (18) is locked, bolt (12) is screwed into the lower hole (17); when coupling (18) is free - into the upper hole (17). In this case, bolt (12) with its end rests against thinning (13), preventing pin (8) from moving inside sleeve (7). All parts of the device are made of metal, permanent connections are made by welding.

[0012] The device operates as follows. A pin is inserted into the sleeve, the cotter pin shaft is threaded through a slot in the sleeve and a radial hole in the pin, the cotter pin head serving as a handle. A bolt is threaded into the lower hole in the sleeve. The coupling is rotated around its axis using a turning device (not shown) to align the axis of the hole in the coupling with the axis of the sleeve, and until the end of the pin (eccentric) enters the hole in the coupling. After this, the pin position is fixed: the bolt is screwed into the lower radial threaded hole in the sleeve until it rests against the thinning on the pin. Stiffening ribs prevent the torque from the windrowing of the gas turbine rotor from breaking the sleeve out of the hole in the coupling housing, although experience has shown that the wall thickness of the coupling housing is sufficient to counteract the torque.The position sensor, in the example shown, an inductive proximity switch mounted on a bracket, sends a signal to the control system that the clutch, and therefore the rotor of the single-shaft gas turbine, is locked, as the upper part of the pin moves out of its active zone. The control system prevents the gas turbine unit from starting. Before starting the gas turbine unit, the bolt is removed from the lower hole in the sleeve, the pin is lifted by the cotter pin head, releasing the clutch. The bolt is screwed into the upper radial threaded hole in the sleeve until it rests against the recess on the pin. The inductive proximity switch sends a signal to the control system that the clutch, and therefore the rotor of the single-shaft gas turbine, is unlocked, as the upper part of the pin enters its active zone. After this, the gas turbine unit can be started.In the illustrated embodiment of the invention, the gas turbine engine is a single-shaft, simple-cycle turbine, in which the air compressor and turbine are mounted on a single shaft and rotate at the same speed. The compressor is single-stage centrifugal with a single impeller (rotor), and the turbine is centripetal, also with a single impeller (rotor). Although this device is proposed for gas turbine engines, it can also be used for other rotating equipment.

[0013] The claimed technical solution for a device for preventing unwanted rotation of a single-shaft gas turbine engine rotor can be implemented in an industrial production environment using standard equipment, modern materials, and technologies. Standard rolled metal products, fasteners, and measuring instruments are used in the manufacture of the device. The device is used in a gas turbine power unit including a Stamford S9H1D generator, an NGC MG170PC16 gearbox, a single-shaft GTD-AA-2000 gas turbine engine of the applicant, and an EAS elastic coupling. ® -HT from Mayr. The device uses a VBI-M18-34S-1111-S type contactless inductive switch, a 4-pin spring pin according to DIN 11024, and an M8×20 bolt according to DIN 933.

[0014] The authors have developed a design for a device to prevent unwanted rotation of a single-shaft gas turbine engine rotor, which has been successfully implemented in the GTEA-0204 gas turbine power unit at the applicant’s production facility.

Claims

1. A device for preventing unwanted rotation of a rotor of a single-shaft gas turbine engine (GTE), comprising a bracket with a sleeve for a pin, movably inserted into the sleeve and having a travel limiter, and a position sensor mounted on the bracket and configured to generate a signal to the control system about the position of the cylindrical pin, characterized in that the bracket is attached to the protective casing of a mechanical clutch that transmits torque from the GTE shaft to the shaft of the driven equipment, the sleeve is secured in an opening made in the protective casing of the mechanical clutch, the pin is configured to enter with its end into an opening made on the surface of the mechanical clutch.

2. The device according to paragraph 1, characterized in that the end of the pin, entering the hole on the surface of the mechanical coupling, has an eccentric.

3. The device according to paragraph 1, characterized in that the end of the pin opposite the mechanical clutch has a thickening that serves as a travel limiter, the diameter of which is larger than the internal diameter of the sleeve.

4. The device according to paragraph 1, characterized in that a radial through smooth hole is made in the middle part of the pin, and a longitudinal slot for a spring pin is made in the sleeve.

5. The device according to paragraph 1, characterized in that a thinning is made in the middle part of the cylindrical pin.

6. The device according to paragraph 5, characterized in that two radial through threaded holes for a fastening element are made along the height of the sleeve in such a way that the fastening element comes into contact with the thinning of the pin, wherein the upper radial threaded hole in the sleeve serves to fix the position of the pin by means of the fastening element when it does not enter the hole on the surface of the mechanical coupling, and the lower hole serves to fix the position of the pin by means of the fastening element when it enters the hole on the surface of the mechanical coupling.

7. The device according to paragraph 1, characterized in that the sleeve is made with stiffening ribs attached to the protective casing of the mechanical coupling.

8. The device according to paragraph 1, characterized in that an inductive contactless switch is used as a position sensor.

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