A precooler (7) for cooling compressor bleed air (38) for an environmental control system (6) includes a heat exchanger (56) in fluid communication with a source of cooling air (57) and operable for cooling the bleed air (38). A variable bypass valve (74) between a bleed air source (116) and environmental control system (6) is operable for bypassing at least a portion of the compressor bleed air (38) around the heat exchanger (56). The cooling air may be a portion of fan air (33) modulated by a variable fan air valve (76). The bleed air source may be selectable between the low pressure bleed air source (116) and a high pressure bleed air source (118). One method includes flowing the compressor bleed air (38) from a single low pressure source only and increasing thrust sufficiently to meet a minimum level of pressure of the bleed air (38) during one engine out aircraft operating condition during approach or loitering.
ENVIRONMENTAL CONTROL SYSTEM SUPPLY PRECOOLER BYPASS
DERIVATION DU PREREFROIDISSEUR D'ALIMENTATION D'UN SYSTEME DE CONDITIONNEMENT D'AIR
2015-09-08
Patent
Electronic Resource
English
Novel high-temperature precooler for aircraft environmental control system
European Patent Office | 2020
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