Patent ID: 8205427
Filing Date: 2012-06-26
Classification: F01D,F02C,F05D,Y02T

Abstract:
1. A heat exchange system comprising: first and second subsystems forming first and second respective liquid flow circuits through which first and second respective lubricants are circulatable to provide selected operations in each respective subsystem; turbine engine parts, portions of which being connected to one of the first and second liquid flow circuits to receive one of the first and second lubricants, respectively; an airstream heat exchanger connected in the first subsystem so as to have the first lubricant pass therethrough to cool the first lubricant at selectively variable rates in airstreams passing thereby during at least some such uses of the turbine engine parts; a coupling heat exchanger connected in both the first and second subsystems to have the first and second lubricants pass therethrough to permit one of the first and second subsystems to cool the other; a subsystem heat exchanger connected in the second subsystem to have both another fluid and the second lubricant pass therethrough; a control system for operating the coupling heat exchanger to determine the amount of heat exchanged therein between the first and second lubricants; and a bypass valve connected in a selected one of the first and second subsystems across the coupling heat exchanger so as to permit flows of a corresponding one of the first and second lubricants therein to bypass the coupling heat exchanger as selected by the control system, wherein the control system operates the bypass valve to selectively bypass the coupling heat exchanger so as to exchange heat from the first lubricant to the second lubricant to be discharged via the subsystem heat exchanger to the another fluid when temperature of the first lubricant exceeds a threshold, and wherein the control system operates the bypass valve to selectively bypass the coupling heat exchanger so as to exchange heat from the second lubricant to the first lubricant to be discharged via the airstream heat exchanger to the airstreams when temperature of the second lubricant exceeds a threshold.