| 摘要 |
Provided is a miller cycle engine in which the thermal efficiency is improved by increasing boost pressure, while the reliability of mechanical strength and thermal load of the engine body is secured by maintaining a maximum in-cylinder pressure. The mirror cycle engine includes an intake valve variable unit (36) for controlling timing to open or close an intake valve (14), a steam. turbine (28) serving as a boost pressure adding device which adds an additional boost pressure to the boost pressure increased by a turbocharger (20) so as to increase only the boost pressure, or so as to increase the boost pressure by the additional boost pressure that is larger than increase in exhaust pressure, and a valve closing timing control unit (34) which advances more the timing to close the intake valve (14) as the additional boost pressure added by the steam turbine (28) becomes higher so as to maintain the boost pressure at substantially the same level as a maximum in-cylinder pressure before adding the additional boost pressure. |
