Based on these findings, on NOx concentration in the emissions, the influence of the cetane index and nitrogen content can be ignored.
3.3 Measurement Results of NOx Concentration and its Fluctuation Factors
Fig.3 shows the results of monitoring NOx concentration and its fluctuation factors regarding these two cogeneration engines. The abscissa axis represents the one-year duration from June 1996 to May 1997. As factors that may be associated with fluctuation in NOx concentration, ambient temperature ta(℃), intercooled air temperature tsc(℃), absolute humidity Ha(g/kg), and engine load factor(%) were monitored. NOx-concentration values were converted into NOx13. The engine load factor was high in July and August because of demand for the power of cooler.
