Abstracts
Among many nominated papers, three technical papers and an annual review have been published in this volume. However, there are excellent papers in the unselected ones, some of them, are summarized hereafter for readers' reference.
Characteristics of deNOx System With Hydrocarbon Reduction Agent on Small Size Test Equipment
By Nakayama Nobuyoshi, Jinja Yoichi, Yamasita Hisashi, Sugata Masahiro, Sonoda Keniche, Yahagi Tuyoshi, Watanabe Motohisa
Authors have carried out experiments for deNOx performance of small size deNOx plant with platinum-zeolite catalyst and propylene reduction agent, for development of deNOx system with hydrocarbon reduction agent.
As result of experiments, following have been found.
(1) The deNOx equipment with hydrocarbon reduction agent is higher reduction efficiency by control of exhaust gas temperature at catalyst.
(2) Supply method of reduction agent influences reduction performance of deNOx equipment, so that divide supply of reduction agent is higher reduction efficiency.
(3) NOx reduction effect of this system with other deNOx method, as fuel injection retard and water emulsified fuel, is comparable without other deNOx method.
(4) After driving this system at about 200 hr, NOx reduction efficiency is not drop.
- Reprinted from Journal of the M.E.S.J., vol.34, No.10 -
In-cylinder Combustion in Spark-Ignited Natural Gas Engine and Its Dependence on Engine Running Conditions
By Yukiyoshi Fukano, Kazuo Tachibana. Shigeo Kida, Toshikazu Kadota
An experimental study was made to investigate in-cylinder combustion in a spark-ignited natural gas engine and its dependence on engine running conditions. Flame propagation in a single-cylinder visualization engine was measured from the cylinder axis direction by the high speed schileren method, over the wide range of spark timing and excess air ratio. The results showed that flame did not propagate concentrically around spark plug electrode, but was shifted by swirl flow. The gravity center of flame area moves corresponding to flow field in the combustion chamber. In the case of partial-burning, flame left from the spark plug electrode, resulting in no more propagation. Cylinder pressure increase is delayed compared to flame propagation. Heat release is detected when flame area occupies around 4% of the combustion chamber area. Heat release shows its maximum when flame area occupies around 70% of the combustion chamber area. Flame area varies cycle-to-cycle within±10% to its average, which is smaller than cycle variation of swirl velocity. Spark liming had little effect on flame propagation and its speed. Larger excess air ratio resulted in more slender flame, slower and more shifted flame propagation. Flame propagation speed, which is negatively proportional to excess air ratio, gets half from about 10m/s to about 5m/s as excess air ratio changes from 1.3 to 1.6.
- Reprinted from Journal of the M.E.S.J., vol.34, No.10 -
