AIRCRAFT AIR SUPPLY AND CONTAMINANT DETECTION SYSTEM
FIG2 is a schematic depiction of an example embodiment of an aircraft air cycle environmental conditioning system
An example embodiment of on-board air cycle cooling system 140 is schematically shown in FIG2. Air cycle cooling system depicts a so-called "four-wheel" system, referring to the four rotating devices (a ram air fan, one compressor, and two turbines), but "three-wheel" systems having only a single turbine are also contemplated. As shown in FIG2, compressed air 212 from a compressed air source (not shown) such as a pre-cooled turbine engine bleed, an APU bleed, or an electrically-powered compressor is delivered through control valve 214. From there, the compressed air is directed to a heat exchanger 215 (also referred to in the art as a primary heat exchanger) where it rejects heat to ambient air flowing through or across a heat absorption side of heat exchanger 215. Cooled compressed air is discharged from heat exchanger 215 to compressor 220. A portion of the air going to heat exchanger 215 can be controllably diverted through conduit 217 and control/expansion valve 219 to mix with the outlet of turbine 244 and control the temperature of the conditioned air exiting the system. Compressor 220 compresses its portion of the air from the heat exchanger 215, which also results in heating of the air. The further compressed air is discharged from compressor 220 through conduit 224 to heat exchanger 226 (also referred to in the art as a secondary heat exchanger) where it rejects heat to ambient air flowing through or across a heat absorption side of heat exchanger 226.
schematic
247
power transfer path
217
controllably diverted through conduit
214
delivered through control valve
230
heat exchanger
245
conduit
213
ambient air
220
compressor
238
being delivered through conduit
241
valve
228
fan
232
is delivered through conduit
226
heat exchanger heat exchangers
219
control/expansion valve
240
turbine turbines
244
turbine turbines
235
unit
212
compressed air
['1. An aircraft pressurized air system, comprising: a compressor (220) that receives and compresses outside air; an air cycle machine (140) that receives compressed air from the compressor and directs conditioned air to an aircraft pressurized zone; and a contaminant sensor (300) disposed along an air flow path between the compressor and the aircraft pressurized zone, comprising an optical guide (302,304), a metal organic framework (306) on an exterior surface of the optical guide in operative fluid communication with air from the air flow path, a light source (318) in communication with the optical guide at a first end of the optical guide, and a light detector (322) in communication with the optical guide at a second end of the optical guide.']