Optical sensor system for time-resolved quantification of methane densities in CH_4-fueled spark ignition engines

Abstract

We present the development and the first application of an optical sensor system that allows single-cycle determination of methane (CH) concentration inside internal combustion (IC) engines. We use non-dispersive infrared absorption spectroscopy to detect the CH density with a time resolution up to 33 μs at acquisition rates of 30 kHz. The measurement scheme takes advantage of the strong temperature dependence of the absorption band applying two detection channels for CH that detect different spectral regions of the ν anti-symmetric C-H-stretch absorption. The strategy allows the simultaneous determination of fuel concentration as well as gas temperature. We show the proof-of-concept by validation of the measurement strategy in static pressure cell experiments as well as its application to a methane-fueled IC engine using a modified spark plug probe. Our results clearly demonstrate that it is crucial to determine the CH temperature in the probe volume. Due to thermal influences of the sensor probe, the temperature needed to calculate the desired quantities (fuel density, fuel concentration) significantly differs from the gas phase temperature in the rest of the combustion chamber and estimations from standard thermodynamic models, e.g., polytropic compression, will fail.

Experimental investigation of effects of magnetic field on performance, combustion, and emission characteristics of a spark ignition engine

“…Hall Effect sensor and shaft encoder NEMICON were used in combination to determine the engine's top dead center (TDC) position as well as the engine crank angles (CADs). LaVision's ICOS‐Temperature system indicates the in‐cylinder and piston temperature with measurement error less than 2% . To measure the temperature of the cylinder and head cylinder, an Amphenol CHT sensor is used.…”

“…LaVision's ICOS-Temperature system indicates the in-cylinder and piston temperature with measurement error less than 2%. 21,22 To measure the temperature of the cylinder and head cylinder, an Amphenol CHT sensor is used. The images of fuel injection by an injector obtained using the "Olympus I SPEED" high-speed video camera.…”