US 12,092,041 B2
Method for monitoring the operating state of a hydro-mechanical unit
Arnaud Bernard Clément Thomas Joudareff, Moissy-Cramayel (FR); and Guilhem Alcide Auguste Foiret, Moissy-Cramayel (FR)
Assigned to SAFRAN AIRCRAFT ENGINES, Paris (FR)
Appl. No. 17/423,349
Filed by SAFRAN AIRCRAFT ENGINES, Paris (FR)
PCT Filed Mar. 19, 2020, PCT No. PCT/EP2020/057694
§ 371(c)(1), (2) Date Jul. 15, 2021,
PCT Pub. No. WO2020/188059, PCT Pub. Date Sep. 24, 2020.
Claims priority of application No. 1902801 (FR), filed on Mar. 19, 2019.
Prior Publication US 2022/0003173 A1, Jan. 6, 2022
Int. Cl. F02C 9/26 (2006.01); F02C 7/232 (2006.01)
CPC F02C 9/263 (2013.01) [F02C 7/232 (2013.01); F05D 2260/80 (2013.01)] 8 Claims
OG exemplary drawing
 
1. A method for monitoring an operating state of a turbomachine hydro-mechanical unit of an aircraft, said hydro-mechanical unit comprising
a metering valve, comprising a movable metering part and allowing a passage, through the metering valve, of a mass flow rate of fuel, depending in particular on a position of the movable part,
a control valve, configured to maintain a predetermined pressure difference (ΔP) at terminals of the metering valve in order in particular to control the mass flow rate of fuel through the metering valve, and
a flow rate meter able to measure the mass flow rate of fuel,
wherein a monitoring module implements the method according to the following steps:
determining a vector of reconstructed flow rates containing reconstructed flow rates for different stabilized points of a flight envelope of the aircraft based on the position of the movable part measured by a position sensor of said part, and on a measurement of a density of the fuel,
calculating a vector of residues containing residues for the different stabilized points of the flight envelope of the aircraft, each residue corresponding to a difference between the mass flow rate as measured by the flow rate meter and the reconstructed flow rate of the vector of reconstructed flow rates for the same stabilized point of the flight envelope of the aircraft, and carrying out a first comparison of said vector of residues to a vector of determined threshold values for the different stabilized points of the flight envelope of the aircraft, and
determining one or several abnormal operating state(s) of the hydro-mechanical unit depending on a result of the first comparison, and wherein, if a residue of the vector of residues is less than the determined threshold value of the vector of determined threshold values for the same stabilized point of the flight envelope of the aircraft, said residue is stored in a memory of the monitoring module.