Air-cooled fuel cell stacks integrated into aircraft wings
A fuel-cell-powered aircraft system has integrated air-cooled fuel cell stacks positioned within an interior space of at least one wing of an aircraft. An airflow path is positioned in contact with at least a heat exchanger of the fuel cell stack. The induced flow of air through the airflow path cools the heat exchanger. The efficiently-induced flow of air for cooling the fuel cell stack has a zero or minimal drag penalty.
1 . A fuel-cell-powered aircraft system comprising:
at least one fuel cell stack positioned within an interior space of at least one wing of an aircraft;
at least one plenum pipe formed by an interior space of a front spar of the at least one wing; and
an airflow path positioned in contact with at least a heat exchanger of the fuel cell stack, wherein induced flow of air through the airflow path cools the heat exchanger.
2 . The system of claim 1 , further comprising ducting directing a position of the airflow path, wherein the airflow path has an inlet positioned along a leading edge of the wing and an outlet positioned along a trailing edge of the wing.
3 . The system of claim 2 , wherein the inlet is positioned along a bottom surface of the leading edge of the wing, and the outlet is positioned along an upper surface of the trailing edge of the wing.
4 . The system of claim 2 , wherein at least one of the inlet or outlet is openable and closable using at least one of: a door, a wing slat, or a wing flap.
5 . The system of claim 2 , wherein the ducting at the outlet is convergent towards the trailing edge of the wing.
6 . The system of claim 2 , further comprising a membrane positioned at the inlet and outlet of the airflow path, wherein the membrane controls the flow of air through the inlet and the outlet.
7 . The system of claim 2 , further comprising at least one fan positioned proximate to the inlet at the leading edge of the wing, wherein the fan induces the flow of air through the airflow path to cool the heat exchanger.
8 . The system of claim 2 , wherein the at least one fuel cell stack positioned within the interior space of the wing further comprises a plurality of fuel cell stacks and the inlet is positioned within a propeller wash, and further comprising a diffuser connected to the inlet at the leading edge of the wing, the diffuser receiving a portion of air from the propeller wash and directing the portion of the air to the plurality of fuel cell stacks.
9 . The system of claim 1 , wherein the at least one fuel cell stack positioned within the interior space of the wing further comprises a plurality of fuel cell stacks, each positioned within the interior space of the wing in a location between a rear spar, the front spar, and at least one rib.
10 . The system of claim 1 , further comprising at least one plenum pipe positioned along at least a portion of a wingspan of the wing, the at least one plenum pipe transporting at least one of: pressurized air and hydrogen for use in high temperature proton exchange membranes (HTPEMs) or coolant for use in low temperature proton exchange membranes (LTPEMs).
11 . The system of claim 1 , further comprising a supplemental air pipe positioned along at least a portion of a wingspan of the wing, wherein airflow is provided to the heat exchanger of the fuel cell stack from the supplemental air pipe.
12 . The system of claim 1 , further comprising a rail positioned within the interior space of the wing along at least a portion of a wingspan of the wing, wherein the fuel cell stack is movably mounted to the rail.
13 . The system of claim 12 , further comprising at least one access opening formed in a skin of the wing, wherein the fuel cell stack is insertable through the access opening and into the interior space of the wing at a first position, and wherein the fuel cell stack is movable along the rail to a second position.
14 . The system of claim 1 , wherein the heat exchanger of the fuel cell stack is positioned within a skin of the wing, wherein the airflow path is positioned exterior of the wing and in contact with the skin of the wing to cool the heat exchanger.
15 . A fuel-cell-powered aircraft system comprising:
a plurality of fuel cell stacks positioned within an interior space of at least one wing of a fuel-cell-powered aircraft, wherein the interior space is formed in a location between a rear spar, a front spar, and at least one rib of the wing;
at least one plenum pipe formed by an interior space of the front spar of the wing; and
at least one airflow path formed between an inlet and outlet located on the wing, and positioned in contact with a heat exchanger of each of the fuel cell stacks in the interior space, wherein an induced flow of air through the airflow path cools the heat exchanger.
16 . A method of cooling at least one of the fuel cell stacks of the fuel-cell-powered aircraft as claimed in claim 15 , the method comprising:
inducing a flow of air through the at least one plenum pipe formed by the interior space of the front spar of the wing of the aircraft; and
directing the flow of air from the plenum pipe to a heat exchanger of the at least one of the fuel cell stacks positioned within the interior space of the wing of the aircraft, whereby the flow of air through the heat exchanger cools the heat exchanger.
17 . The method of claim 16 , further comprising controlling the flow of air with at least one of a door, a membrane, a wing slat, or a wing flap positionable over an inlet of the airflow path positioned along a leading edge of the wing or an outlet of the airflow path positioned along a trailing edge of the wing.
18 . The method of claim 16 , wherein the flow of air is induced by at least one of: a freestream flow, a propeller wash, at least one fan positioned proximate to an inlet of the airflow path, or a supplemental air pipe positioned along at least a portion of a wingspan of the wing.
19 . The method of claim 16 , wherein contacting the heat exchanger of the fuel cell stack positioned within the interior space of the wing of the aircraft further comprises: contacting a heat exchanger of each of a plurality of fuel cell stacks, each positioned within the interior space of the wing of the aircraft in a location between a rear spar, the front spar, and at least one rib.
20 . The system of claim 1 , wherein the at least one fuel cell stack is positioned along an airflow path.