Compressor pre-spin control method

摘要

A method is provided for controlling a pre-spin operation of a compressor of an internal combustion engine provided with a turbocharger. The presence of a turbocharger imposes additional requirements on the method. The wear of a compressor clutch is proportional to the transferred energy when the clutch is engaged. In order to reduce the wear of the compressor clutch, or increase the maximum engine speed where it is allowed to engage the compressor, a compressor pre-spin operation is used to reduce the transferred energy when the clutch is engaged. The pre-spin is achieved by controlling the air mass flow over the compressor by controlling a bypass throttle angle of a bypass throttle. The bypass throttle is provided in a parallel conduit to the compressor, bypassing the compressor. Since the air mass flow over the compressor affects the air mass flow to the turbocharger, the method takes the turbocharger into consideration.

主权项

1. A method for controlling a pre-spin operation of a compressor of an internal combustion engine, wherein the internal combustion engine comprises an air intake, a compressor conduit, a bypass conduit and a turbocharger, wherein the air intake is in fluid communication with an air inlet of the turbocharger, the compressor conduit comprises a compressor and is arranged between the air intake and the turbocharger such that the compressor is in fluid communication with the air intake and the turbocharger, and the bypass conduit comprises a bypass throttle and is arranged in fluid communication with the air intake and the turbocharger inlet such that the bypass conduit bypasses the compressor, wherein a compressor clutch connects the compressor to a crankshaft of the internal combustion engine such that the compressor can be engaged and disengaged from the crankshaft, and wherein the bypass throttle can be controlled by setting a bypass throttle angle such that the bypass throttle can be controlled between an open position and a closed position, the method comprising:
checking a number of conditions including:
if the compressor clutch is in a disengaged state,if a load of the internal combustion engine is in a predetermined load range,if an air mass flow delivered by the turbocharger is within a predetermined mass flow range,if a speed of the compressor is below a threshold value, andif the bypass throttle is at least partially open; and if the conditions are fulfilled, performing the following: calculating a bypass throttle angle dependent on at least a mass flow over the internal combustion engine and a target pressure difference over the compressor such that a predetermined pre-spin of the compressor is achieved, the internal combustion engine load stays in the predetermined load range, and the air mass flow delivered by the turbocharger stays within the predetermined mass flow range; and setting the bypass throttle angle according to the calculated bypass throttle angle.