REAL CYCLE OF A COMPRESSION IGNITION ENGINE RUNNING IN DUAL-FUEL REGIME: DIESEL AND NATURAL GAS

Abstract

The engines converted to natural gas usually emit great amounts of no burned fuel due to bad quality of the conversion devices. The technology of the natural gas engine has been applied commercially in the Otto cycle engines, but it is still incipient in engines of Diesel cycle. It is necessary to improve the technology of the dual-fuel engines, knowing their characteristics and its better operation. One of the items that there aren't sufficient studies is the real cycle of operation of a dual-fuel engine, working simultaneously with Diesel and natural gas. This work aims to study the existent differences in the diagram of pressures inside of a Diesel engine cylinder, running on Diesel regime and the same engine running under a dual fuel regime (diesel ‒ natural gas). The tests were accomplished in Diesel engine purposely modified to run on dual-fuel regime with electronic injection of gas. Ten (10) experiments (test bench)were carried out with duration of 25 seconds for the engine running on Diesel and dual-fuel combustibles. The peak of pressure of the engine running in regime Diesel presented lower values than those observed for the dual-fuel regime. In the dual-fuel regime, the peak was accentuated and it has a short duration, approximating of the pattern of an Ottocycle. Keywords: Diesel engine, dual-fuel engine, natural gas, Diesel oil, diagram of pressures, experimental investigation.