| Quantifying nonroad engine emission levels under different ambient and operating conditions can complement current manufacturer's certifications. An initial data set consisting of CAN, weather, and emissions information was obtained from a 104 hp LPG irrigation engine using different RPM and torque settings over an ambient temperature range of 75°F to 103°F. Polynomial models were developed to determine what variables affect emission levels of oxides of nitrogen (NOx) and Carbon Monoxide (CO) at different ambient and operating conditions. Variables shown to have a direct affect on predicting NOx emission levels at 90 percent confidence levels were fuel rate, rpm, and humidity. Variables shown to have a direct affect on predicting CO emission levels at 76 percent confidence levels were rpm, percent torque, and manifold temperature. Using modeling software to predict gaseous emissions of a LPG engine is possible. |
