Fuel metering circuit and method with compensation for fuel-density variability

Patent metadata

Field	Value
Publication number	US-11365692-B2
Application number	US-201816630705-A
Country	US
Kind code	B2
Filing date	Jul 13, 2018
Priority date	Jul 13, 2017
Publication date	Jun 21, 2022
Grant date	Jun 21, 2022

Abstract

A fuel metering circuit for a turbomachine includes: a meter; a pump; a control valve configured to return an excess flow of fuel delivered to the meter towards the pump on the basis of a fuel pressure differential at the terminals of the meter; a diaphragm; and a volumetric flow meter. The diaphragm and the volumetric flow meter are mounted parallel to the meter, downstream of the control valve, in order to determine a density of the fuel flowing in the metering circuit.

First claim

The invention claimed is:

1. A fuel metering circuit for a turbomachine comprising:
a metering device;
a pump configured to circulate a fuel flow rate toward the metering device;
a regulating valve configured to regulate the fuel flow rate delivered to the metering device according to a difference in fuel pressure at terminals of the metering device;
a diaphragm; and
a volume flow meter configured to determine a volume flow rate of fuel passing through the diaphragm,
wherein the diaphragm and the volume flow meter are mounted in parallel with the metering device in a bypass duct, downstream of the regulating valve, in order to determine a density of the fuel circulating in the metering circuit.

2. The metering circuit according to claim 1 , wherein the volume flow meter is mounted upstream or downstream of the diaphragm.

3. The metering circuit according to claim 1 , further comprising an electronic card configured to receive information from the volume flow meter on the volume flow rate of the fuel and adjust a metering device monitoring setpoint by taking into account the fuel density thus determined.

4. The metering circuit according to claim 1 , wherein the pump comprises a volumetric pump.

5. A turbomachine comprising a fuel metering circuit according to claim 1 .

6. An aircraft comprising the turbomachine of claim 5 .

7. A fuel metering method implemented in a fuel metering circuit according to claim 1 , the method comprising:
determining the difference in fuel pressure at the terminals of the metering device;
measuring the volume flow rate of the fuel using the volume flow meter; and
calculating, from the difference in fuel pressure, from the volume flow rate and from constants related to the diaphragm, the fuel density.

8. The metering method according to claim 7 , further comprising a step during which the flow meter transmits information on the volume flow rate of the fuel to an electronic card and the electronic card adjusts a metering device monitoring setpoint by taking into account the fuel density.

9. The metering method according to claim 7 , wherein the fuel flow rate is monitored by recirculating a variable fuel flow rate toward the pump by the regulating valve.

Assignees

• Safran Aircraft Engines

Inventors

• Pora Loic
• Joudareff Arnaud Bernard Clement Thomas

Classifications

• F02C9/263 Primary

  by means of fuel metering valves · CPC title

• F02C7/22 Primary

  Fuel supply systems · CPC title

• F05D2240/35

  Combustors or associated equipment · CPC title

• F05D2220/323

  for aircraft propulsion, e.g. jet engines · CPC title

• F02C7/232

  Fuel valves {(control of fuel supply by means of fuel metering valves F02C9/263)}; Draining valves or systems (valves in general F16K) · CPC title