JP4142673B2 - Control device for gas turbine engine - Google Patents

Description

  The present invention relates to a control device for a gas turbine engine, and more particularly to a control device for allowing safe operation to continue even when an abnormality occurs in a pressure sensor of a compressor.

  In an aircraft gas turbine engine, various sensors are used to optimally control the operating state of the engine. The compressor outlet pressure (P3) and the fuel flow rate (Qfr) are set as control parameters such as Qfr / P3. Then, since the air-fuel ratio characteristics at the time of acceleration and deceleration are improved and misfire is difficult, it is regarded as one of the most important control parameters, and it is required to obtain an appropriate value. If a sensor that outputs such a value serving as the basis of a control parameter fails, the control parameter exhibits an abnormality, which hinders proper control of the engine. Therefore, a countermeasure at the time of sensor failure is extremely important.

  As a countermeasure against sensor failure, it is common to provide a plurality of sensors at one measurement point and compare the output values of each sensor to determine the presence or absence of an abnormality. In view of the above constraints and manufacturing costs, it is difficult to provide a plurality of sensors.

Thus, conventionally, when the outlet pressure of the compressor shows an abnormal value, the output value of the sensor is filtered or replaced with a certain fixed value. Further, a technique for shifting to a no-load operation mode when an output value of the sensor is abnormal is known (see Patent Document 1).
JP 2003-184578 A

  However, with this conventional countermeasure, the difference between the substitute value and the normal value may become too large depending on the engine operating condition, resulting in a longer deceleration time. I had to rely heavily on the skill of the pilot. The control method described in Document 1 is effective for a stationary engine, but is not practically applicable to an aircraft engine.

  In view of such disadvantages of the prior art, the present invention is relatively quick to a stable state without suddenly changing the operating state of the engine even when the output value of the sensor for detecting the outlet pressure of the compressor shows an abnormality. It was set as a subject to be able to be converged to.

In order to solve such a problem, a control apparatus for a gas turbine engine according to the present invention includes an outlet pressure detecting means (high pressure sensor 8) for detecting an outlet pressure (P3) of a compressor (2), and a fan (6). A control apparatus for a gas turbine engine having an inlet pressure detecting means (low pressure sensor 9) for detecting an inlet pressure (P1), wherein a relationship between an engine speed, an intake air temperature, and an output value of the inlet pressure detecting means. Outlet pressure estimating means (high pressure value estimating section 24) for estimating the outlet pressure of the compressor based on the output value determining means (high pressure sensor output determining section) for determining whether or not the output value of the outlet pressure detecting means is normal 22) and when the output value determination means determines that the output value of the outlet pressure detection means is not normal, the output value of the outlet pressure detection means is replaced with the output value of the outlet pressure estimation detection means And If the output value of the outlet pressure estimated detection means is determined to be abnormal, the output selecting means for replacing the output value of the outlet pressure detecting means by the output value of the inlet pressure detecting means (the output selection unit 23) Have

  According to the present invention as described above, even if the compressor outlet pressure detection means malfunctions, an alternative value that can continue operation stably is provided, so that sudden changes in engine behavior are suppressed and engine operation is stabilized. Can be continued.

  Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

  FIG. 1 shows a schematic configuration of a gas turbine engine controlled by a control device to which the present invention is applied. This gas turbine engine 1 has a high-pressure shaft 4 that connects a compressor 2 and a high-pressure turbine 3, and a low-pressure shaft 7 that connects a low-pressure turbine 5 and a fan 6, and an outlet pressure P 3 of the compressor 2 is detected by a high-pressure sensor 8. The inlet pressure P1 of the fan 6 is detected by the low pressure sensor 9, the rotational speed N2 of the high pressure shaft 4 is detected by the high pressure shaft rotation sensor 10, and the inlet temperature T1 of the fan 6 is detected by the intake air temperature sensor 11, respectively. The fuel flow rate controller 15 controls the fuel metering valve 16 so that the fuel flow rate supplied to the combustion chamber 17 is controlled so that the engine shows an optimal response based on the outputs of the various operating condition detection sensors. It has become.

  Since the high-pressure sensor 8 is provided under severe conditions of high temperature and high pressure, the high-pressure sensor 8 is configured so that the minimum stable operation can be continued even when the output becomes abnormal due to failure, for example. A device for responding to an abnormality is provided. This abnormality response device includes an operation mode determination unit 21, a high-voltage sensor output determination unit 22, an output selection unit 23, and a high-pressure value estimation unit 24.

  In the operation mode discriminating unit 21, for example, based on the output value N2 of the high-pressure shaft rotation sensor 10 and the output TA of the throttle lever angle sensor 12, mode discrimination value maps 31 and 32 (FIG. 2, FIG. The operation state at that time is determined with reference to 3). As the operating state discriminated here, start ST, low load steady operation LR, acceleration operation AC, high load steady operation HR, deceleration operation DC, emergency fuel cut-off CO, and the like are set. In this embodiment, the mode discrimination values based on the output values of the high-pressure shaft rotation sensor 10 and the throttle lever angle sensor 12 are exemplified, but not only these values are referred to but also the values of speedometers, altimeters, etc. It may be possible to further improve the discrimination accuracy by referring to a flight schedule set in advance.

  The high pressure value estimation unit 24 includes an engine rotation speed correction value N2C obtained by correcting the output value N2 of the high pressure shaft rotation sensor 10 at the inlet temperature T1 of the fan 6 output by the intake air temperature sensor 11, and a fan output by the low pressure sensor 9. 6 stores an estimated high-pressure value calculation map set by actually measuring the relationship with the inlet pressure P1 of 6 by a bench test, and inputs the inlet temperature T1 and inlet pressure P1 of the fan 6 and the high-pressure shaft rotational speed N2. Then, an estimated high pressure value P3E is obtained. However, N2C is given by the following equation.

  Next, a control parameter selection processing flow according to the present invention will be described with reference to FIG.

  First, the operation mode discriminating unit 21 performs a mode check, and the operation mode at that time (starting ST, low load steady operation LR, acceleration operation AC, high load steady operation HR, deceleration operation DC, emergency fuel cut-off CO). Is discriminated (step 1).

  Next, the reference value map 33 (FIG. 5) stored in the high-voltage sensor output determination unit 22 is referred to, and a reference value corresponding to the operation mode at that time (for example, in the range of A to D in FIG. In the case of the steady load operation mode, a range of B to C) is set (step 2).

  At the same time, the output value P3 of the high-pressure sensor 8 is captured (step 3), and this value is compared with the reference value by the high-pressure sensor output determination unit 22 to determine whether or not the value is within a specified range (step 4). More specifically, in this step, the output value P3 of the high-pressure sensor 8 is sampled, for example, every 10 msec, and the sampled value is compared with a reference value. Is determined.

  If it is determined that the high-pressure sensor 8 is normal, the output selection unit 23 outputs the output value P3 at that time as a control parameter (step 5). On the other hand, if it is determined to be abnormal here, it is checked whether or not the previous time was normal (step 6). If the previous time was normal, the current abnormal value is assumed to be transient. The previous P3 value stored is output as a control parameter (step 7). On the contrary, if the previous time was also abnormal, it is determined that the high-pressure sensor 8 is abnormal, and it is determined whether or not the estimated high-pressure value P3E obtained from the high-pressure value estimating unit 24 is normal (step 8).

  Whether the estimated high pressure value P3E is correct or not is determined by referring to the time history and a predetermined threshold value for the rotational speed N2 of the high pressure shaft 4, the inlet temperature T1 of the fan 6, and the inlet pressure P1. In addition, the inlet temperature T1 and the inlet pressure P1 of the fan 6 are compared with three values output from each sensor provided on the airframe side and on the engine side, and if the two values match, the values are used. The rotation speed N2 of the high-pressure shaft 4 is assumed to be a correct value, and the four values output from each sensor provided on the fuselage side and two on the engine side are compared. It shall be regarded as a correct value.

  If it is determined that the estimated high pressure value P3E is normal, the estimated high pressure value P3E is output as a control parameter from the output selection unit 23 to control the engine (step 9). On the other hand, when it is determined that the estimated high pressure value P3E is abnormal, the output selection unit 23 outputs the output P1 of the low pressure sensor 9 as a control parameter, and performs engine control (step 10).

  The output value P1 of the low-pressure sensor 9, that is, the inlet pressure of the fan 6, is relatively high in the measurement environment itself, and has high reliability because the sensor is provided on both the engine side and the airframe side. Can be ensured. Accordingly, although the output value P3 of the high-pressure sensor 8, that is, the outlet pressure of the compressor 2 is different, a similar tendency value can be obtained. Therefore, in order to continue the operation of the engine that can ensure the required minimum stability. This is far more advantageous than controlling by substituting with a certain constant or correcting the output value P3 of the unreliable high voltage sensor 8.

  If the output value P1 of the low-pressure sensor 9 is replaced, it prevents the misfire in the high sky where the P1 value is small, and because the engine speed is low, the relative difference between P1 and P3 is small and the absolute value of P1 is large. Can contribute to prevention of deterioration of air-fuel ratio characteristics on the ground or in the low air.

  Thus, in the present invention, when the high-pressure sensor 8 that detects the outlet pressure of the compressor 2 has an abnormality, the fan is finally replaced with an alternative value that can continue the minimum stable operation. By giving the output value P1 of the low pressure sensor 9 that detects the inlet pressure of 6, the engine behavior can be prevented from changing suddenly and stable continuation of the engine operation can be realized.

When the output value P1 of the low-pressure sensor 9 is abnormal, it is dealt with by giving a value of standard atmospheric pressure (1.003 kgf / cm ² ).

It is a schematic block diagram of this invention apparatus. It is a conceptual diagram of an operation mode discriminant value map. It is a conceptual diagram of another operation mode discriminant value map. It is a control flowchart of this invention apparatus. It is a conceptual diagram of a reference value map.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Gas turbine engine 2 Compressor 6 Fan 8 High pressure sensor 9 Low pressure sensor 22 High pressure sensor output determination part 23 Output selection part 24 High pressure value estimation part

Claims (1)

A control device for a gas turbine engine having outlet pressure detecting means for detecting an outlet pressure of a compressor and inlet pressure detecting means for detecting an inlet pressure of a fan,
Outlet pressure estimating means for estimating the outlet pressure of the compressor based on the relationship between the rotational speed of the engine, the intake air temperature, and the output value of the inlet pressure detecting means;
Output value determination means for determining whether or not the output value of the outlet pressure detection means is normal;
When the output value determination means determines that the output value of the outlet pressure detection means is not normal, the output value of the outlet pressure detection means is replaced with the output value of the outlet pressure estimation detection means, and An output selection means for replacing the output value of the outlet pressure detection means with the output value of the inlet pressure detection means when the output value of the outlet pressure estimation detection means is determined to be abnormal ;
A control device for a gas turbine engine comprising:

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