PRELIMINARY EVALUATION OF A HEAT PIPE HEAT EXCHANGER ON A REGENERATIVE TURBOFAN

摘要

A preliminary evaluation was made of a regenerative turbofan engine using a heat pipe heat ex¬changer. The heat exchanger had an effectiveness of 0.70, a pressure drop of 3 percent on each side, and used sodium for the working fluid in the stainless steel heat pipes. The engine was compared to a reference turbofan engine originally designed for service in 1979. Both engines had a bypass ratio of 4.5 and a fan pressure ratio of 2.0. The design thrust of the engines was in the 4000 N range at a cruise condition of Mach 0.98 and 11.6 km. This study showed that heat pipe heat exchangers of this type would cause a large weight and size problem for the engine. The penalties were too severe to be overcome by the small uninstalled fuel consumption advantage. This type heat exchanger should only be considered for small airflow engines in flight ap¬plications. Ground applications might prove more suitable and flexible.