Controlling the operation of a compressor

Abstract

A method and apparatus for controlling a compressor 22 of a turbocharger 20 fitted to an internal combustion engine in which the maximum permitted outlet temperature of the compressor is adjusted based upon an age factor representing an equivalent age of the compressor if the compressor 22 were to be operated at a predetermined outlet temperature. In this way a higher boost pressure can safely be used during the early life of the compressor 22 but excessive coking of the compressor 22 with a resultant loss of efficiency later in the life of the compressor 22 is avoided. The method can further comprise repetitively determining, for successive predetermined time periods, discrete age factors based on the instantaneous outlet temperature of the compressor during the predetermined time period, wherein the compressor total age factor is a summation of various discrete age factors.

Description

[0001] related application [0002] This application claims priority from UK Patent Application No. 1102342.1 filed 10 February 2011, the entire contents of which are hereby incorporated by reference for all purposes. technical field [0003] The present disclosure relates to boosted engine systems, and in particular to methods for controlling compressors forming part of such systems. Background technique [0004] It is known to improve the torque and emissions performance of diesel engines using exhaust-gas driven turbochargers or superchargers. For a strongly supercharged diesel engine, whether supercharged or turbocharged, the outlet temperature of the compressor of the supercharger (T comp-out ) are usually the limiting factors in determining the maximum permissible boost level. Many factors exist to determine the limit T comp-out , such as the materials used to make the engine's intake manifold, but often the least of these factors is related to compressor coking cau...

AI Technical Summary

Problems solved by technology

[0007] This method of control is disadvantageous because for most bus users, the proportion of time that they operate at conditions related to the maximum allowable compressor outlet temperature is very small

Images