Gas turbine engine with geared turbofan and oil thermal management system with unique heat exchanger structure

A gas turbine engine comprising:

• a fan, a compressor section, including a low pressure compressor section and a high pressure compressor section;
• a combustor;
• a turbine section including both a low pressure turbine and a high pressure turbine section, and said low pressure turbine section driving said low pressure compressor section;
• and
• a fan drive gear system provided such that said low pressure turbine further driving said fan, with said fan and said low pressure compressor being driven at different rates;
• a lubricant system including a lubricant pump delivering lubricant to an outlet line, said outlet line splitting into at least a hot line and into a cool line, said hot line being directed primarily to locations in the gas turbine engine that are not intended to receive cooler lubricant, and said cool line being directed through at least one heat exchanger at which the lubricant is cooled, and said cool line then being routed to at least a journal bearing for said fan drive gear system;
• and
• said at least one heat exchanger including at least an air/oil cooler wherein air is pulled across said air/oil cooler to cool lubricant, and said air/oil cooler being provided with an ejector tapping compressed air from a compressor section to increase airflow across the air/oil cooler;
• and
• at least a portion of the lubricant in said cool line passing through a first fuel/oil cooler configured to cool the lubricant using fuel, leading to a combustion section of the associated gas turbine engine, and the lubricant in said hot line not passing through said first fuel/oil cooler.

A method of managing lubricant supply for a gas turbine engine comprising the steps of:

• moving a lubricant from a main lubricant pump into an outlet line, and splitting the outlet lines into a cool line which is delivered into at least one heat exchanger to cool the lubricant, and the cooled lubricant then being delivered to at least a journal being for a gear reduction that drives a fan associated with the gas turbine engine;
• supplying lubricant from a hot line which is not passed through said at least one heat exchanger to bearings associated with at least a turbine section in the gas turbine engine;
• said at least one heat exchanger including at least an air/oil cooler wherein air is pulled across said air/oil cooler to cool lubricant, and said air/oil cooler being provided with an ejector tapping compressed air from a compressor section to increase airflow across the air/oil cooler;
• and
• passing at least a portion of the lubricant in the cool line through a first fuel/oil cooler configured to cool the lubricant using fuel, leading to a combustion section of the associated gas turbine engine, and the lubricant in said hot line not passing through said first fuel/oil cooler.