TECHNICAL FIELD

The present disclosure relates to a fuel supply control device.

BACKGROUND ART

Patent Document 1 discloses a fuel supply apparatus for a gas turbine engine. The fuel supply apparatus operates a centrifugal pump (low-pressure pump) and a gear pump (high-pressure pump) by controlling and driving a motor (electric motor) with a motor controller (fuel supply control device), and supplies desired fuel to fuel nozzles through parallel flow passages of a fixed orifice and a pressurizing valve. Further, the motor controller takes a front-rear differential pressure across the fixed orifice, that is, the pressurizing valve, which is detected by a differential pressure gauge, as a feedback signal; and performs the feedback control of the electric motor on the basis of a difference between the feedback signal and a command signal that is taken from full authority digital engine control (FADEC) that is a control device electrically controlling an engine for an airplane on the basis of the position of a throttle lever and inputs from various sensors.

CITATION LIST

Patent Document

[Patent Document 1] Japanese Unexamined Patent Application, First Publication No. 2013-231406

SUMMARY OF THE INVENTION

Technical Problem

The fixed orifice and the pressurising valve function as a metering valve, but there is a possibility that the front-rear differential pressure may be unstable in a high flow-rate range where the pressurizing valve is opened. Accordingly, there is a possibility that it may be difficult to perform stable fuel supply control in the high flow-rate range where the pressurizing valve is opened in the fuel supply control device in the related art.

The disclosure has been made in consideration of the above-mentioned circumstances, and an object of the disclosure is to achieve stable fuel supply control in a high flow-rate range where a pressurizing valve is opened.

Solution to Problem

According to a first aspect of the disclosure, there is provided a fuel supply control device that is configured to control a fuel supply pump on the basis of a front-rear differential pressure across a metering valve for a fuel supply amount, which is detected by a differential pressure gauge, using parallel flow passages of an orifice and a pressurizing valve as the metering valve. The fuel supply control device includes a first control amount generation unit that is configured to generate a first control amount on the basis of the front-rear differential pressure, a second control amount generation unit that is configured to generate a second control amount on the basis of a rotation speed of the fuel supply pump, a control amount selection unit that is configured to alternatively select the first control amount or the second control amount on the basis of the rotation speed and to output the selected control amount, a subtractor that is configured to calculate a deviation of an output of the control amount selection unit from a control target value and to output the deviation, and a control calculation unit that is configured to calculate an operation amount of the fuel supply pump on the basis of an output of the subtractor. The control amount selection unit is configured to select the first control amount in a case where the rotation speed is equal to or lower than a predetermined threshold and to select the second control amount instead of the first control amount in a case where the rotation speed exceeds the threshold.

According to a second aspect of the disclosure, in the first aspect, the first control amount generation unit is configured to generate the first control amount on the basis of a differential pressure-fuel supply amount conversion table showing a relationship between the front-rear differential pressure and a flow rate of fuel.

According to a third aspect of the disclosure, in the first or second aspect, the second control amount generation unit is configured to generate the second control amount on the basis of a rotation speed-fuel supply amount conversion table showing a relationship between the rotation speed and a flow rate of fuel.

According to a fourth aspect of the disclosure, in the third aspect, the second control amount generation unit is configured to generate the second control amount by correcting an output of the rotation speed-fuel supply amount conversion table on the basis of an estimation value of leakage of fuel acquired in advance about the fuel supply pump.

According to a fifth aspect of the disclosure, in any one of the first to fourth aspects, the second control amount generation unit is configured to generate the second control amount by taking a rotation speed of a motor, which drives the fuel supply pump, as the rotation speed of the fuel supply pump.

According to a sixth aspect of the disclosure, in any one of the first to fifth aspects, the control amount selection unit is configured to alternatively select the first control amount or the second control amount on the basis of a rotation speed of a gas turbine instead of the rotation speed of the fuel supply pump in a case where fuel is supplied to the gas turbine.

According to a seventh aspect of the disclosure, in any one of the first to sixth aspects, the control calculation unit is configured to calculate the operation amount of the fuel supply pump by performing PID calculation processing on the output of the subtractor.

According to the disclosure, it is possible to achieve stable fuel supply control in a high flow-rate range where a pressurizing valve is opened.

