Gas turbine engine

A gas turbine engine comprising:

• a casing that accommodates a compressor, a combustor, and a turbine;
• fuel pump units at an outside of the casing, the fuel pump units being lined up in a circumferential direction along an outer peripheral surface of the casing, the fuel pump units being connected in parallel;
• a fuel supply pipe that collects fuel discharged from the fuel pump units and supplies the fuel to the combustor;
• a fuel suction pipe that guides the fuel stored in a fuel tank to the fuel pump units by negative pressure generated in the fuel pump units;
• a rotational frequency sensor that detects a rotational frequency of a rotating shaft;
• and
• a controller that controls the fuel pump units in accordance with a detected value of the rotational frequency sensor, wherein:
• each of the fuel pump units includes
• a displacement pump including a rotation axis, and
• an electric motor that is adjacent to the displacement pump in a direction along the rotation axis of the displacement pump and drives the displacement pump;
• a discharge port of the displacement pump is at an opposite side of the electric motor in the direction along the rotation axis of the displacement pump, the discharge port being oriented in the direction along the rotation axis;
• an inlet port of the displacement pump is located at the opposite side in the displacement pump in the direction along the rotation axis, the inlet port being oriented in the direction along the rotation axis;
• the fuel supply pipe includes
• a common pipe extending toward the combustor, and
• branch pipes extending from the common pipe toward an upstream side;
• the fuel supply pipe is at the opposite side of the electric motors across the displacement pumps of the fuel pump units;
• the branch pipes are connected to the discharge ports of the displacement pumps in the direction along the rotation axis;
• the fuel suction pipe connects the inlet ports of the displacement pumps to the fuel tank in the direction along the rotation axis;
• the controller compares the rotational frequency detected by the rotational frequency sensor with at least one threshold and determines a fuel pump unit to be stopped among the fuel pump units in accordance with a relation between the rotational frequency and the at least one threshold;
• when the gas turbine engine is started in a state where the rotational frequency detected by the rotational frequency sensor is zero, the controller stops at least one of the fuel pump units;
• and
• when the rotational frequency detected by the rotational frequency sensor exceeds a predetermined threshold, the controller increases a number of fuel pump units to be driven among the fuel pump units.