| 摘要 |
<p>The present invention provides a method for reducing frost formation on a heat transfer surface in a precooler of an air breathing engine. In the precooler (1), the heat exchanger tube (2) is provided. Into the heat exchanger tube (2), liquid hydrogen (12) serving as a coolant is supplied. The main air flow (11) is sent to the precooler (1) via the intake duct (3), and the main air flow which is cooled down there, is then sent to a compressor of the air breathing engine. Via the nozzle (4) provided in the intake duct (3), liquid oxygen (13) is sprayed into the main air flow (11). As the sprayed liquid oxygen (13) is vaporized, the main air flow (11) in the intake duct (3) is cooled down to a temperature below the dew point, and the water vapor contained in the main air flow (11) is condensed by nucleation. Ice piece thus formed is carried on the main air flow (11) into the precooler (1). As the vapor passes around the heat exchanger tubes (2) in the form of ice piece, the amount of the frost formation on the surface of the heat exchanger tube (2) is reduced as compared to the case where the vapor passes as it is. <IMAGE></p> |
