Means for handling gaseous fuel
In accordance with at least one aspect of this disclosure, there is provided a system for an aircraft engine. In embodiments, the system includes an accessory box and a fuel accessory located in an interior space within the accessory box, where a vent is defined through a wall of the accessory box. In embodiments, the vent includes a plurality of holes or slots in an outer wall of the accessory box for passage of gaseous fuel from the interior space. In embodiments, the vent is configured for passive ventilation of the interior space.
1. A system for an aircraft engine of an aircraft, the system comprising:
an accessory box;
a fuel accessory located in an interior space within the accessory box;
a sensor operatively connected to detect fuel gas within the interior space;
a ventilation system in fluid communication with the interior space, the ventilation system including a selective vent defined through a wall of the accessory box, the selective vent having a venting configuration and a closed position, the selective vent including an exhaust port door defined through the wall of the accessory box for fluid communication between the interior space and an ambient environment external to the accessory box; and
a controller operatively connected to the sensor and to the ventilation system, wherein the controller includes machine readable instructions configured to cause the controller to:
command the ventilation system to actively purge the interior space of fuel gas upon receipt of an input signal from the sensor indicative of presence of the fuel gas within the interior space.
2. The system as recited in claim 1 , wherein the venting configuration of the selective vent allows flow out from the interior space to the ambient environment and wherein the closed position blocks said flow.
3. The system as recited in claim 1 , wherein the ventilation system includes a compressor bleed conduit in selective fluid communication with the interior space through a valve, wherein the valve is operatively connected to the controller to place compressor bleed air in fluid communication with the interior space upon detection of fuel gas in the interior space.
4. The system as recite in claim 1 , wherein the ventilation system includes:
an air scoop door communicating with the accessory box and upstream of the exhaust port door relative to purge flow out of the exhaust port, wherein the air scoop door includes an actuator configured to selectively move the air scoop door between an open position and a closed position, wherein the open position allows flow from the interior space to the ambient environment and wherein the closed position blocks said flow.
5. The system as recited in claim 4 , wherein the wall of the accessory box having the exhaust port door is a radially outer wall of the accessory box, and wherein the air scoop door is positioned on a radially inner wall of the accessory box.
6. The system as recited in claim 1 , wherein the ventilation system includes:
a source of compressed inert gas in selective fluid communication with the interior space through a valve, wherein the valve is operatively connected to the controller to place the source of compressed inert gas in fluid communication with the interior space upon detection of fuel gas in the interior space.
7. The system as recited in claim 1 , wherein the sensor includes at least one of a temperature sensor, a flame sensor, and/or a gas species sensor.
8. The system as recited in claim 1 , wherein the accessory box is located in a nacelle.
9. The system as recited in claim 8 , wherein an outer wall of the accessory box forms a portion of an outer nacelle wall of the nacelle, the outer nacelle wall facing radially outward away from the aircraft engine.
10. The system as recited in claim 1 , wherein the fuel accessory includes a plurality of fuel accessories, each fuel accessory having an interface connected between another of the plurality of fuel accessories, wherein at least each interface is included within the accessory box.
11. The system as recited in claim 1 , wherein the fuel accessory includes at least one of a valve, a metering unit, a tube, and/or a tube fitting, a pump, and/or an evaporator.
12. The system as recited in claim 11 , wherein at least some fuel accessories convey liquid therein and wherein at least some fuel accessories convey gas therein, wherein the gas is evaporated from the liquid.
13. The system as recited in claim 1 , further comprising:
the aircraft engine; and
a fuel system configured to combust gaseous fuel, the fuel system in fluid communication with a fuel source through the at least one fuel accessory, wherein the accessory box is above the aircraft engine relative to the direction of gravity when the aircraft is on the ground.