| 摘要 |
A turbocharging arrangement comprises a first stage (1) and a second stage (2) turbocharger, the first and second stages being arranged to operate in sequence, the first stage turbocharger comprising a turbine having a turbine bypass valve (8), or a wastegate. The size of the bypass valve (8) is chosen to produce a smooth transition from single to twin turbocharger operation. The gas bypassing the first stage turbine (T1) is used to accelerate the second stage turbocharger turbine (T2) during a load/speed change. This has the effect of reducing, and preferably negating, the transient discontinuity. Electronic control of the diverted gas is preferable but the bypass valve or wastegate can be controlled by the pressure generated by the turbocharger compressor. Improved steady state output is seen from the engine over a wide operating range. |
