US Patent 8205427 Interdependent lubrication systems in a turbine engine

A heat exchange system for use in operating equipment having a plurality of subsystems in each of which one of a plurality of working fluids is utilized to provide selected operations with there being an air and working fluid heat exchanger providing controlled cooling to cool at least one of the plurality of working fluids in its corresponding subsystem. In addition, a coupling heat exchanger is also provided connected to two of the subsystems to pass there working fluids therethrough, including the subsystem with the air and working fluid heat exchanger, to allow one of the connected subsystems to aid in cooling the other.