Patent Application
20140138490
An aircraft will typically include an ice protection system to prevent excessive ice accumulation on its wings, stabilizers, engine inlet lips, and/or pylons. The ice protection system can incorporate an array of contiguous deicing zones associated with areas surrounding the leading edge. Each deicing zone can include envelope having an electrothermal layer which converts electric power to heat for deicing of the associated area.
According to one embodiment, an ice protection system comprising a first set of contiguous deicing zones is disclosed. In this embodiment, each deicing zone comprises an envelope defining an ice-protection area; at least two of the envelopes are adjacent and share a common interzone border; each of the adjacent envelopes includes an edge region flanking the interzone border; and the edge region of at least one of the adjacent envelopes is configured to enhance ice deicing at the interzone border by providing a higher heating power density than the rest of the envelope.
Referring to
Referring to
The surface 20 is provided with an ice protection system 40 comprising an ice protection array 50 and a controller 60 operably connected to the array 50. The illustrated ice protection array 50 comprises a first set 100 of contiguous deicing zones 101-103, a second set 200 of contiguous deicing zones 201-203, and an anti-icing zone 310. The anti-icing zone 310 will usually coincide with the leading edge 30 and can be positioned between the fore zone 101 of the first deicer set 100 and the fore zone 201 of the second deicer set 200.
While the surface 20 appears flat in the drawing, this is simply for ease in illustration and explanation. In most instances, the surface 20 will have a curved profile wrapping around the leading edge 30 of the associated aircraft structure. If, for example, the ice-susceptible surface 20 is on a wing 12 or a horizontal stabilizer 13, the deicing zones 101-103 could be located on upper portion of the wing/stabilizer and the deicing zones 201-203 could be located on its lower portion. If the surface 20 resides on the vertical stabilizer 14 or one of the pylons 16, the deicing zones 101-103 could occupy its rightside portions and the deicing zones 201-203 could occupy its leftside portions. If the surface area 20 is on one of the engines 15, the deicing zones 101-103 could be situated on inner lip portions and the deicing zones 201-203 could be situated on outer lip portions.
The deicing zones 101-103 in the first deicer set 100 each comprise an envelope 111-113 defining an ice protection area 121-123. Each envelope 111-113 includes an electrothermal heater layer 131-133 which converts electric power to heat to deice the corresponding ice-protection area 121-123. The envelopes 111-113 can comprise further layers (e.g., layers 141-143, layers 151-153, etc.) surrounding the heater layers 131-133 for thermal transfer, electrical insulation, and/or protection purposes.
The envelopes 111-112 share a common interzone border 160 and the envelopes 112-113 share a common interzone border 170, which both extend generally in a spanwise direction perpendicular to the airstream direction A. The interzone border 160 is flanked by an end region 161 of the envelope 111 and an end region 162 of the envelope 112. The interzone border 170 s flanked by an end region 172 of the envelope 112 and an end region 173 of the envelope 113.
The envelope 111 has a non-common (e.g., fore) border 180 adjacent its edge region 181 and the envelope 113 has a non-common (e.g., aft) border 190 adjacent its edge region 193. The border 180 and the border 190 also extend generally in a spanwise direction perpendicular to the airstream direction A.
The deicing zones 201-203 in the second deicer set 200 include similar envelopes 211-213 defining ice protection areas 221-223 and including envelope layers (e.g., layers 231-233, layers 241-243, layers 251-253, etc.). They also include an interzone border 260 (flanked by envelope edge regions 261 and 262), an interzone border 270 (flanked by envelope edge regions 272 and 273), a fore border 280 (adjacent envelope edge region 281), and an aft border 290 (adjacent envelope edge region 293). The interzone border 260, the interzone border 270, the fore border 280, and the aft border 290 extend generally in a direction perpendicular to the airstream direction A.
The anti-icing zone 301 can include an envelope 311 defining an ice protection area 321, housing an electrothermal heater layer 331, and including additional envelope layers 341 and 351. The anti-icing zone 310 can be bounded by borders 160 and 260 and flanked by envelope edge regions 161 and 261.
Referring to
In a zoned electrothermal deicing procedure, the power-supply episodes are executed in a staggering schedule so as to minimize power-draw spikes. The heaters' episodes are collectively viewed in terms of time intervals t1-tn, with different heaters being supplied power during different intervals. A cycle is completed when a power-supply episode has occurred for each deicing zone.
In
The anti-icing zone 301 is continuously supplied with power in all of the illustrated power-supply procedures. This continuous supply of electrical power is intended to persistently heat the corresponding ice protection area 311 so that ice never even forms thereon. The use of such an anti-icing approach along a leading edge is considered customary in airfoil ice protection.
As was indicated above, the envelope structures commonly include further layers (e.g., layers 141-143, layers 151-153, etc.) surrounding the heater layers 131-133, at least some of which are for electrical insulation and/or protection purposes. As such, envelope constructions can often hinder the transfer of ice-melting heat to edge regions of the deicing zones. This hindering is especially apparent when two adjacent deicer envelopes share a common interzone border (e.g., envelopes 111-112 sharing border 160, adjacent envelopes 112-113 sharing border 170, adjacent envelopes 211-212 sharing border 260, and adjacent envelopes 212-213 sharing border 270).
When designing a deicer envelope, the non-heating layers are generally optimized to provide adequate electrical insulation, sufficient environmental protection, maximum heat transfer, lighter weights, lower power draws, and longer lives. As such, trimming parameters along edge regions could compromise electrical insulation and environmental protection. Likewise, protracting parameters within non-edge regions could cause weight and power-draw concessions.
The ice protection system 40 addresses border-heat-hindrance issues by configuring envelope edge regions to enhance deicing at such interzone boundaries.
As shown in
As shown in the 8th through 13th drawing sets, the heating layers 131-133 of the deicing zones 101-103 can comprise heating elements 135-137 and the heating layers 231-233 of the deicing zones 201-203 can comprise heating elements 235-237. These heating elements can comprise conductive tracks printed, etched, laid, or otherwise posed in a heating pattern within the heating layers. Increased power density in the relevant edge regions can be achieved by tighter spacing, higher heights, and/or wider widths of the tracks.
As shown in the 14th through 16th drawing sets, the heating elements 135-137 and 235-237 can instead each comprise a single track printed, etched, laid, or otherwise posed in a solid heating pattern. The heating layers 131-133 and 231-233 can include bus bars (not shown) for supply and return of electric power to and from the solid heating pattern. Increased power density in the relevant edge regions can be achieved by higher resistance and/or higher heights of the single solid tracks.
An increased power density in envelope edge regions can translate into more power being used by a particular deicing zone during each episode. However, analytical results indicate that a slight increase in per-episode power can result in a dramatic decrease in total deicing time, and thus a remarkable reduction in overall power. As shown in
As shown in
Although the aircraft 10, the aircraft surface 20, the system 40, the array 50, the controller 60, the deicing zones 101-103, the deicing zone 201-203, and/or the anti-icing zone 301 have been shown and described with respect to a certain embodiments, it is obvious that equivalent alterations and modifications will occur to others skilled in the art upon the reading and understanding of this specification and the annexed drawings. Specifically, for example, ice protection systems with more or less deicing and/or anti-icing zones are feasible and foreseeable. And while a particular feature of the aircraft 10 or the system 40 may have been described above with respect to some of the illustrated embodiments, such feature may be combined with one or more other features of the other embodiments, as may be desired and advantageous.
This application claims priority under 35 U.S.C. 119(e) to U.S. Provisional Patent Application No. 61/623,047, filed Apr. 11, 2012, entitled “DEICER ZONES WITH HEATING-ENHANCED BORDERS”, and to Application No. 61/623,050, filed Apr. 11, 2012, entitled “DEICER ZONES WITH SHEDDING-ENHANCED BORDERS”, both of which are incorporated herein by reference in their entirety.
| Number | Date | Country | |
|---|---|---|---|
| 61623047 | Apr 2012 | US | |
| 61623050 | Apr 2012 | US |
