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. An aircraft engine comprising:
an accessory box located in a nacelle of the aircraft engine radially outward from a bypass duct defined between an engine core of the aircraft engine and the nacelle, the accessory box being located outside a bypass airflow through the bypass duct;
a fuel accessory located in an interior space within the accessory box; and
a blast door engaged to a wall of the accessory box at an opening in the wall of the accessory box, the blast door moveable between a first position covering the opening and a second position, wherein the accessory box is airtight when the blast door is in the first position, and wherein in the second position the blast door opens a flow path extending from the interior space of the accessory box to the bypass duct via a detonation duct, the detonation duct located within the nacelle radially outward from the bypass duct and connecting the interior space of the accessory box to the bypass duct for relief of pressure in the accessory box in the event of a detonation in the interior space.
2. The aircraft engine as recited in claim 1 , wherein the blast door is engaged to the accessory box with a frangible connection configured to release the blast door from the accessory box to open the flow path in the event of a detonation in the interior space.
3. The aircraft engine as recited in claim 1 , wherein the blast door is hingedly engaged to the accessory box with a biased hinge, wherein the biased hinge biases the blast door to the first position with a biasing force configured to be overcome by a detonation within the interior space.
4. The aircraft engine as recited in claim 3 , wherein the biased hinge is positioned on an upper portion of the accessory box, wherein the blast door is configured to swing open on the biased hinge from the first position to the second position to deflect detonation gas downward in the event of a detonation in the interior space.
5. The aircraft engine as recited in claim 1 , further comprising a deflector mounted in the nacelle between the blast door and a portion of the engine core radially inward from the accessory box.
6. The aircraft engine as recited in claim 1 , wherein the blast door is passive, configured to open from the first position under forces of a detonation within the interior space.
7. The aircraft engine as recited in claim 6 , further comprising a sensor operatively connected to the blast door to detect opening of the blast door and produce an output signal indicative of the blast door opening.
8. The aircraft engines as recite in claim 1 , wherein the wall of the accessory box includes a carbon fiber and/or synthetic fiber material.
9. The aircraft engine as recited in claim 1 , further comprising an inlet port and an outlet port for evacuation of gas from the interior space.
10. The aircraft engine as recited in claim 1 , wherein the fuel accessory includes one or more of: a valve; a metering unit; a tube; a tube fitting; a pump; and an evaporator.
11. The aircraft engine as recited in claim 10 , wherein the fuel accessory conveys gaseous fuel therein, wherein the gaseous fuel is evaporated from liquid fuel.
12. The aircraft engine as recited in claim 1 , further comprising: a fuel system configured to combust gaseous fuel, the fuel system in fluid communication with a fuel source through the fuel accessory, wherein the aircraft engine is configured such that the accessory box is above the engine core, relative to the direction of gravity, when the aircraft engine is mounted to an aircraft and the aircraft is level relative to the ground.