Experimental Research And Calibration Of HCNG Engine

As one of the solution for petroleum crisis and environment protection, hydrogen enriched compressed natural gas (HCNG) also acts as a feasible way to transform vehicle fuel from conventional fuel to hydrogen gas. This paper uses EQD210N-20 natural gas engine made Dongfeng as a base engine and calibrate the ECU of CNG engine by burning HCNG fuel with volumetric ratio 20% Hydrogen. The HCNG engine calibrated must pass the European III emission standard and meet the power and economy requirement of HCNG vehicle.The thesis analyzes the software of ECU by studying the material of ITMS system designed by Delphi, and then adjusts the ECU to HCNG fuel by calibration experiment. The calibration experiment of HCNG engine includes three facets: steady condition calibration, idle condition calibration and transient condition calibration.In the steady condition HCNG engine uses two different air-fuel ratio strategy and spark timing retarded properly in wide open throttle (WOT) condition and other operation condition to keep the same power as the CNG engine and obtain better emission. Idle condition calibration is focused mainly on idle air control (IAC) and advanced spark timing. The advanced spark timing is changed greatly to fit the HCNG fuel because the combustion stabilization of HCNG fuel is better than CNG fuel in the idle condition. Some fuel control modes which designed for gasoline in the transient condition are eliminated because they are not suit gas fuel. The highest priority of the transient condition calibration has been given to the power and emission requirement.Acceleration performance, maximum speed, maximum degree of climbing and economic performance of HCNG vehicle meet the design requirement in the road test. The HCNG engine has passed the European European III emission standard by European test cycle (ETC).