Mass integration of fast-response NO measurements from a two-stroke large-bore natural gas engine

Abstract

Abstract

A thermodynamic two-stroke-cycle engine simulation with a quasi-steady scavenging model was developed and used to mass-integrate cycle-resolved NO measurements made with a fast-response NO analyser. The engine tested was a Cooper-Bessemer GMV-4TF large-bore natural gas engine and the fast NO measurements were made in cylinders 2 and 4 using a Cambustion fNO_x400 two-channel fast-response analyser. The engine simulation was deemed to provide a good representation of the cycle-resolved scavenging mass flow. The mass-integrated NO results were compared to Fourier transform infrared (FTIR) steady measurements taken downstream of the cylinders 2 and 4 exhaust-manifold junction. The correlation between the two techniques was linear to within 2 per cent. A strong correlation was exhibited between mass-integrated cycle-to-cycle NO and measured peak and crank angle location of peak combustion pressure. The correlation with peak pressure was slightly better than the location of peak pressure.