JP4771411B2 - Start control method for gas turbine engine - Google Patents

Description

  The present invention relates to a gas turbine engine including a starter motor and a lubricating oil pump, and to a start control method used to start the gas turbine engine.

  FIG. 4 is a timing chart for explaining a start control sequence of a conventional gas turbine engine. In a conventional gas turbine engine, when a start signal is input, the lubricating oil pump is driven (ON) to supply lubricating oil to bearings of rotating shafts such as the output shaft of the starter motor and the output shaft of the engine. Then, it is determined whether the lubricating oil is sufficiently supplied to the bearing based on the pressure of the lubricating oil. After the hydraulic pressure detection sensor detects a predetermined pressure value (ON), the starter motor is started (ON). I was trying to start the engine.

  Conventionally, the lubricating oil pump is driven together with the input of the start signal, the lubricating oil pump is stopped once, and then the lubricating oil pump and the starter motor are simultaneously driven to lubricate the sliding portion of the engine. A technique for preventing the state from becoming excessive or insufficient depending on the lubricating oil temperature has been proposed (Patent Document 1).

Patent Document 1 relates to an engine starter, not a gas turbine engine. In addition, a gas turbine engine keeps driving a lubricating oil pump even after the engine is started. In the starter, the lubricating oil pump is stopped when the starter motor is stopped.
JP 2000-310172 A

  However, in the conventional start control method of the gas turbine engine as described above, when the environmental temperature is low, the viscosity of the lubricating oil increases, and the lubricating oil is supplied to the bearing of the rotating shaft including the output shaft of the starter motor. Since the starter motor is started, there is a problem in that it is difficult to smoothly increase the engine speed because the bearing loss on the rotating shaft increases.

  In Patent Document 1, since the once stopped lubricating oil pump and the starter motor are simultaneously driven, when the environmental temperature is low and the viscosity of the lubricating oil is high, the lubricating oil is rotated including the output shaft of the starter motor. The starter motor is started while supplying the shaft bearing, and as a result, the bearing loss in the rotating shaft is not improved.

  The present invention has been made in view of the above-described conventional situation, and suppresses bearing loss in the rotating shaft including the output shaft of the starter motor even when the ambient temperature is low and the viscosity of the lubricating oil is high. An object of the present invention is to provide a start control method for a gas turbine engine that can smoothly increase the rotational speed of the engine.

A start control method for a gas turbine engine according to the present invention includes a starter motor and a gas turbine engine including a lubricant pump that supplies lubricant to a bearing of a rotary shaft including an output shaft of the starter motor. When the start signal is input, the lubricating oil pump is driven for a predetermined time, and after the lubricating oil pressure reaches a predetermined value, the lubricating oil pump is stopped and then the starter motor is started. The configuration is such that the driving of the pump is resumed, and the above configuration is used as means for solving the conventional problems.

  In this type of gas turbine engine, a single-shaft engine having a compressor impeller and a turbine rotor on the same engine output shaft, and a compressor impeller and a turbine rotor on each of an engine input shaft and an engine output shaft are provided. There is a two-axis type, and the one-axis type rotates the engine output shaft with a starter motor, and the two-axis type rotates the engine input shaft with a starter motor. At this time, the output shaft of the starter motor may be integrated with the engine output shaft or the engine input shaft, or may be separated from these and connected by a power transmission mechanism.

  Therefore, in the present invention, as the rotation shaft, in addition to the output shaft of the starter motor, an engine output shaft or an engine input shaft integrated with the output shaft of the starter motor, an engine output shaft separate from the output shaft of the starter motor, or Includes engine input shaft.

Also, starting control method for a gas turbine engine according to the present invention, as a more preferred embodiment, the rotation of the engine is started by the scan Tatamota when it has the critical speed of the rotary shaft system while reaching the rated speed, It is characterized in that the drive of the lubricating oil pump is resumed when the engine speed is lower than the critical speed.

  According to the start control method of the gas turbine engine of the present invention, the initial lubricating oil is supplied to the bearing of the rotating shaft including the output shaft of the starter motor, and the starter motor is started with the lubricating oil pump stopped. Even when the ambient temperature is low and the viscosity of the lubricating oil is high, the starter motor starts up and the initial lubricating oil temperature rises quickly and the viscosity decreases quickly, allowing the starter motor to start smoothly. The engine can be started, and then the supply of the lubricating oil is restarted, so that the engine speed can be increased smoothly while suppressing bearing loss in the rotating shaft.

  According to the start control method for a gas turbine engine of the present invention, after the start of the initial drive of the lubricant pump, after the lubricant pressure reaches a predetermined value, the lubricant pump is temporarily stopped to start the starter motor. Therefore, the engine can be started by starting the starter motor after reliably obtaining a state where the pressure of the lubricating oil has reached a predetermined value, that is, a state where the initial lubricating oil is supplied to the bearing.

  Furthermore, according to the start control method for a gas turbine engine of the present invention, the drive of the lubricating oil pump is resumed when the engine speed is lower than the critical speed of the rotating shaft system. When passing through the shaft, sufficient lubricating oil is supplied to the bearing of the rotating shaft, so that the bearing can be smoothly rotated and the life of the bearing can be extended.

  Further, according to the start control method considering the critical speed of the rotating shaft system as described above, when the bearing of the rotating shaft including the output shaft of the starter motor is a high-speed bearing supported by a squeeze film damper, As a result, it is possible to achieve a smooth rotation operation of the high-speed bearing and to extend the life of the high-speed bearing.

  Hereinafter, an embodiment of a start control method for a gas turbine engine according to the present invention will be described with reference to the drawings. FIG. 1 is a diagram for explaining a gas turbine engine 1 to which the start control method of the present invention can be applied.

  The illustrated gas turbine engine 1 is a single-shaft regenerative engine, and includes a starter motor 2 that also serves as a generator and an engine case 3, and an intake path between the housing 4 of the starter motor 2 and the engine case 3. 5 is formed. Further, the gas turbine engine 1 includes an output shaft 6 in which an output shaft of the starter motor 2 and an engine output shaft are integrated as a rotating shaft.

  The output shaft 6 is provided with a compressor impeller 7 disposed in the intake passage 5 and a turbine rotor 8 disposed in a combustion gas passage 13 which will be described later. The output shaft 6, the compressor impeller 7 And the turbine rotor 8 rotate integrally with each other.

  The output shaft 6 is held in the housing 4 by a plurality of high-speed bearings 9 supported by squeeze film dampers (oil films). That is, a gap is provided between the housing 4 and each high-speed bearing 9 to allow the radial displacement of each high-speed bearing 9 and restrict movement in the axial direction, and the squeeze is squeezed by the lubricating oil supplied to the gap. A film damper is formed.

  Further, the gas turbine engine 1 includes a lubricating oil supply means including a lubricating oil pump 21 and a hydraulic pressure detection sensor 22 that detects the pressure of the lubricating oil, and the lubricating oil is supplied from a nozzle disposed in the vicinity of the high-speed bearing 9. Is supplied to form a squeeze film damper, and lubricating oil is injected from another nozzle to lubricate the inside of the high-speed bearing 9. In addition to supplying the lubricating oil to the high-speed bearing 9, the lubricating oil supplying means can supply the lubricating oil to the bearings of the other rotating shafts and the sliding portions of the power transmission mechanism.

  The engine case 3 accommodates a combustor 12 having an ignition plug 10 and a fuel injection valve 11, a combustion gas flow path 13 continuous with the combustor 12, and a heat exchanger 14 continuous with the combustion gas flow path 13. An air passage 15 is formed between these and the engine case 3, and the previous turbine rotor 8 is disposed in the combustion gas passage 13.

  Although the illustration of the inside of the heat exchanger 14 is omitted, the combustion gas passage extending from the combustion gas passage 13 to the outside, and the introduction portions 16 provided at the upper and lower portions of the heat exchanger 14 to the combustor 12 are provided. A heat exchange air flow path leading to the air supply unit 17 is provided, and heat exchange is performed between the fuel gas and the air to achieve high efficiency of operation.

  In addition to the above-described configuration, the gas turbine engine 1 includes fuel supply means including a battery connected to a starter motor 2 that also serves as a generator, a fuel tank, a fuel pump, and the like, and an electronic device for controlling the engine as a whole. Control means are provided. The electronic control means inputs signals from the start switch, the stop switch, the oil pressure detection sensor 22 and the like, and controls the lubricating oil pump 21 and the starter motor 2 based on these signals to start the engine, adjust the rotational speed, and The engine is to be stopped.

  Furthermore, the gas turbine engine 1 is compact and easy to carry by providing a casing that houses the entire engine, a cooling fan that introduces outside air into the casing, and the like. As a drive source, it can be used for various purposes, and by using the starter motor 2 also serving as a generator, the overall structure is simplified and downsized.

  FIG. 2 is a timing chart for explaining a start control sequence which is an embodiment of the start control method of the gas turbine engine 1.

  In the start control method of this embodiment, when a start signal is input, first, the lubricant pump 21 is started (ON), the initial lubricant is supplied to the high-speed bearing 9 and the squeeze film damper, and driven for a predetermined time. The lubricating oil pump 21 is temporarily stopped (OFF). At this time, in the start control method, after the driving of the lubricating oil pump 21 is started, the pressure of the supplied lubricating oil is detected by the oil pressure detection sensor 22, and after the pressure of the lubricating oil reaches a predetermined value (oil pressure detection). After the signal from the sensor 22 turns ON), the lubricating oil pump 21 is temporarily stopped.

  Then, the starter motor 2 is started (ON) while the lubricating oil pump 21 is stopped, the compressor impeller 7 and the turbine rotor 8 are rotated together with the output shaft 6, and then the oil film in the high-speed bearing 9 and the squeeze film damper. The drive of the lubricating oil pump is restarted (ON) before the power is cut off.

  Thereby, the gas turbine engine 1 is started. That is, the outside air is compressed by the compressor impeller 7 and introduced into the combustor 12. In the combustor 12, the compressed air and the fuel injected from the fuel injection valve 11 are mixed and burned. Rotating drive. Thereafter, the starter motor 2 functions as a generator.

  In the start control method described above, the initial lubricating oil is supplied to the high-speed bearing 9 and the squeeze film damper of the output shaft 6, the lubricating oil pump 21 is temporarily stopped, and the starter motor 2 is started. When the oil viscosity is high, the conventional start control method in which the starter motor 2 is started while supplying the lubricating oil has a large bearing loss. On the other hand, the temperature of the initial lubricating oil quickly increases as the starter motor 2 starts. And the viscosity quickly decreases, so that the starter motor 2 can be started smoothly and the engine 1 can be started.

  In the start control method, after the starter motor 2 is started as described above, the supply of the lubricating oil is resumed, so that the engine speed can be increased smoothly while suppressing the bearing loss of the output shaft 6. Realizes a smooth start of the engine.

  Also, according to the start control method, after starting the initial drive of the lubricating oil pump 21, after the lubricating oil pressure reaches a predetermined value, the lubricating oil pump 21 is temporarily stopped and the starter motor 2 is started. The starter motor 2 is started after obtaining the state in which the oil pressure reaches a predetermined value, that is, the state in which the initial lubricating oil is sufficiently supplied to the high speed bearing 9 and the squeeze film damper. Increased further.

  FIG. 3 is a timing chart for explaining a start control sequence which is another embodiment of the start control method of the gas turbine engine 1 shown in FIG.

  Here, this type of small gas turbine engine 1 generally has a very high rated speed (for example, 50,000 to 100,000 rpm), and passes the critical speed of the rotating shaft system until the rated speed is reached. In some cases, the shape of the rotating shaft is designed so that the vibration in the high-speed rotation range is small. In such a rotating shaft system, it is well known that a method of attenuating vibration in a dangerous speed and a high-speed rotation region by supporting the high-speed bearing 9 with a squeeze damper (oil film) is effective.

  For this reason, in the gas turbine engine 1, when the rotational speed of the output shaft 6 passes the dangerous speed, the load on the output shaft 6 and the bearings also increases. Need to be done smoothly.

  Therefore, in this embodiment, after the start signal is input, the lubricating oil pump 21 is driven for a predetermined time, and after the hydraulic pressure reaches a predetermined value, the lubricating oil pump 21 is temporarily stopped, and then the starter motor 2 is started and lubricated. The driving of the oil pump 21 is resumed in order, but the lubricating oil pump 21 is driven at a speed Nx at a stage lower than the critical speed Nc while the rotational speed of the engine (output shaft 6) reaches the rated rotational speed N from start-up 0. Restart the drive.

  As a result, according to the start control method, the same effect as in the previous embodiment can be obtained, and the high speed bearing 9 and the squeeze film can be obtained before the rotational speed of the engine (output shaft 6) passes the critical speed. Sufficient lubricating oil is supplied to the damper to realize smooth operation of the high speed bearing 9 and the squeeze film damper when passing through the dangerous speed, and to reduce the load applied to them to extend the life of the bearings. be able to.

  It should be noted that the gas turbine engine start control method according to the present invention is not limited to the above-described embodiments in the details of the configuration and the structure of the applicable gas turbine engine, and is not limited to the scope of the present invention. Details and the like can be changed as appropriate.

  In addition, since the gas turbine engine start control method according to the present invention deals with a case where the environmental temperature is low and the viscosity of the lubricating oil is high, for example, a temperature sensor for measuring the temperature of the lubricating oil is used to measure the temperature. When the value is equal to or lower than the predetermined value, the above-described control (the control shown in FIGS. 2 and 3) is performed, and the measured value of the temperature sensor does not reach the predetermined value due to conditions such as the environmental temperature or immediately after the engine is stopped. That is, when the viscosity of the lubricating oil is low, for example, it is possible to perform the same control as the conventional one (control shown in FIG. 4).

  However, the start control method of the gas turbine engine can be applied not only when the environmental temperature is low and the viscosity of the lubricating oil is high, but also when the environmental temperature is high and the viscosity of the lubricating oil is low. As a result, the engine can be started well without being influenced by the environmental temperature.

It is sectional drawing explaining the gas turbine engine which can apply the starting control method of this invention. It is a timing chart explaining the starting control sequence which is one Example of the starting control method concerning this invention. It is a timing chart explaining the starting control sequence which is another Example of the starting control method concerning this invention. It is a timing chart explaining the conventional starting control sequence.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Gas turbine engine 2 Starter motor 6 Output shaft 9 High-speed bearing 21 Lubricating oil pump 22 Oil pressure detection sensor

Claims (2)

In a gas turbine engine equipped with a starter motor and a lubricating oil pump that supplies lubricating oil to a bearing of a rotary shaft including the output shaft of the starter motor, when the gas turbine engine is started, lubrication is performed after a start signal is input. A gas characterized in that the oil pump is driven for a predetermined time, and after the lubricating oil pressure reaches a predetermined value, the lubricating oil pump is temporarily stopped, the starter motor is started, and then the driving of the lubricating oil pump is resumed. A start control method for a turbine engine.   When the rotating shaft system has a critical speed between the start of engine rotation by the starter motor and the rated speed, restart the drive of the lubricant pump when the engine speed is lower than the critical speed. The start control method for a gas turbine engine according to claim 1.

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