| 摘要 |
PROBLEM TO BE SOLVED: To provide a fuel flow control circuit allowing injection of a flow rate of fuel proportional to the displacement of a nozzle flapper during normal operation and sudden increase/decrease of the flow rate of fuel with less time lag and high responsibility during sudden acceleration/deceleration. SOLUTION: This fuel flow control circuit comprises a fuel pump 1 for applying pressure to liquid fuel, a measuring valve 2 for measuring the pressure fuel to be supplied to a combustor, a bypass valve 5 for bypassing the pressure fuel to be returned to the upstream side of the fuel pump, and a differential pressure sensor valve 6 for controlling the bypass valve. The differential pressure sensor valve 6 has a spool 6a to be moved at a differential pressureΔP, a spring 6b for energizing the spool against upstream pressure P1 and a spring shift device 10 for shifting a seat of the spring to the direction of moving the spool. The spring shift device 10 is used to position the seat of the spring 6b at a low differential pressure position L and a high differential pressure position H, so that the differential pressureΔP is controlled to be a constant low differential pressureΔP1 at the low differential pressure position L and to be a constant high differential pressureΔPh at the high differential pressure position H.
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