Rong-Fang Horng

Reaction of the electrically-heated catalyst of a four-stroke motorcycle engine under cold-start conditions with additional enrichment of the intake mixture

Abstract By using additional fuel enrichment, the influence of an electrical heater and the oxidation of unburnt exhaust gases on the reaction of an electrically-heated catalyst under cold-start condition of a four-stroke motorcycle engine was investigated. The effects of different cold-start enriching times, heating temperatures, exhaust settings of the CO level and heating positions were studied. The heating temperatures were 60, 80, 100 and 120°C, and the CO levels were 1.0 and 1.8 per cent. The two heating positions were at the inlet and the mid-section of the catalyst. The results showed that additional enrichment of the intake mixture can reduce the heating temperature for self-reaction of the catalyst as well as improve the conversion effciency of the catalyst on the exhaust emissions. High conversion effciency has been achieved for a heating temperature as high as 100°C for the 1.8%CO setting level. It has also been revealed that self-reaction of the catalyst was not possible for a heating temperature of up to 140°C in the case of a 1.0%CO setting level.

The effects of vibration and reciprocating on boiling heat transfer in cylindrical container

Abstract The performance of enhancing boiling heat transfer in cylindrical container was studied experimentally. The effects of the heat load, the grain size of the steel and plastic balls added in the container, the vibration frequency of the disk, and the reciprocation frequency of the cylindrical container on the characteristics of heat transfer were investigated in detail for water as working fluid. The experiment results show that the active methods can really improve the boiling heat transfer promisingly. That is, the heat transfer can be raised only by adding an appropriate amount of additives inside the heated container with vibration or reciprocating rotation, then the boiling heat transfer can be raised by 20∼65% without increasing the heating area.

THE EFFECT OF GROOVED PATTERN ON ENHANCED BOILING HEAT TRANSFER IN A CYLINDRICAL TANK BASE WITH A CONSTANT SURFACE AREA

The effect of grooved pattern on enhanced boiling heat transfer in a cylindrical tank base with a constant surface area was studied experimentally. The effects of vibration and reciprocating rotation on enhanced boiling heat transfer were also tested and discussed in the research. The experimental model consists of integrated copper piping structure and an aluminum cylindrical tank with an equal cross-section stainless pipe between cylindrical tank and its seal lid. The working fluid is distilled water. Besides the effect of different grooved pattern on enhanced boiling heat transfer was investigated, the effect of either different frequency of vibration or reciprocating rotation was also studied in this experiment

Study on the operating range for syngas production by oxidation dry reforming of biogas

This study investigated syngas (H2+CO) production by oxidation dry reforming of biogas, and its operating range was discovered. In order to describe the characteristics of MDR (Methane Dry Reforming) and ODR (Oxidation Dry Reforming), the chemical equilibrium calculation and analysis were performed using the minimum of Gibbs free energy. The main parameters settings are CO2/CH4 ratio between 0.1-1.5, and O2/CH4 ratio between 0.1-0.6. The equilibrium calculations were conducted with various parameters to reveal the produced components, and carbon formation. Therefore, the results could reveal and avoid carbon formation in experiments. Due to the DR (Dry reforming) reactions are endothermic, thus, an additional oxygen supply in reforming reactions could cause heat release in oxidation reaction. The heat release in oxidation reaction was utilized as the energy source for DR. Whereas, O2/CH4 ratio should be well selected because over high settings would cause oxidation of fuel and thus decrease in syngas production.

Purification of H 2 -rich gas from methanol reformer by preferential oxidation over Pt-Ru/Al 2 O 3 catalyst

A methanol reformer with a purification system was designed and investigated in this study. Hydrogen was produced by ATR (auto-thermal reforming), and reformate gas was purified by WGS (water gas shifting reaction) and PrOX (preferential oxidation). The investigated parameters were GHSV (gas hourly space velocity) and O2/CO (oxygen/carbon monoxide molar ratio). Experimental results showed that hydrogen concentration was 28.52% and carbon monoxide concentration was 7.67% in hydrogen-rich gas from ATR reformer. Through the water gas shifting reactor, CO concentration was as low as 0.81%. The improvement of CO was 98.58% under the GHSV=7800 h-1 and O2/CO=1.44. The reformate gas sampled in the outlet of preferential oxidation reactor, CO concentration was measured as low as 12 ppm at GHSV=3900 h-1. The overall H2 flow rate of 23.24 L/min could be supplied for the requirement of a 1.5 kW fuel cell system. By performing a 4-hour stability test, the CO could be controlled around as low as 50 ppm, and H2 concentration could be maintained at approximately 32%-33%.