Process and system for controlling effective compression ratios in an engine cylinder

摘要

The present disclosure is directed at the control of an effective compression ratio setting in an engine which may use a variety of fuels or fuel blends. The effective compression ratio may be selected based upon information from a fuel sensor and stored information regarding the detected fuel composition. The effective compression ratio may be adjusted for a selected cylinder by intake or exhaust valve timing.

主权项

1. A method for adjusting the amount of mass in a selected cylinder undergoing compression comprising:
providing a database, wherein the database includes at least one physical or optical property for each of a plurality of fuels having different compositions, and targeted volume compression ratios for the plurality of fuels; identifying a fuel from the plurality of fuels in the database with a fuel composition sensor which senses a presence of the fuel by sensing the presence of the at least one physical or optical property of the fuel; identifying a targeted volume compression ratio for said fuel from said database from a plurality of targeted volume compression ratios for said fuel, said plurality of targeted volume compression ratios including at least a first targeted volume compression ratio to optimize energy output, a second targeted volume compression ratio to optimize fuel consumption, and a third targeted volume compression ratio to optimize emissions output; determining a time period for opening and closing at least one of an intake valve and exhaust valve sufficient to provide an effective compression ratio for said fuel in said selected cylinder based upon the targeted volume compression ratio for said fuel; opening and closing at least one of said intake valve and exhaust valve at said time period to provide said effective compression ratio; wherein said effective compression ratio is within +/−10% of said targeted volume compression ratio for said fuel; wherein said selected cylinder is a cylinder of an internal combustion engine which operates with variable valve timing; and wherein said effective compression ratio is achieved without use of an external air-injection compressor.