Search Results

Smoke is the most obvious part of the exhaust emitted from Diesel engines. The methods for smoke testing currently used in Taiwan are the rapid acceleration test under no load and the constant speed test under full load. The smoke concentration is measured with the light reflection method. According to the test procedure, the smoke meter sampling time in the rapid acceleration test is 1∼2 seconds. The current range in sampling time may cause discrepancies in test results. In these tests, free acceleration of engine is achieved by actuating the pedal rapidly. However, the speed of engine acceleration has not been defined clearly in the test procedure. The objective of this research is to study the effect of the operating conditions upon the results of smoke tests. Experiments were carried out in this study. The results of measurements showed that the opacity of the engine exhaust increased rapidly after a delay of about 0.3 seconds and then fell.

Recently, due to the concern on shortage in the supply of energy source as well as the greenhouse effect of engine exhaust, the use of renewable fuel, e.g., biodiesel, in the transportation sector is promoted. However, there are distinctions on both the physical and chemical properties between biodiesel and fossil diesel. These deviations in fuel property would result in different combustion characteristics and affect the performance of exhaust aftertreatment system, including the catalytic converter and the diesel particle filter. The purpose of this study is to investigate the effect of biodiesel on the performance and the durability of diesel particle filter. The biofuel adopted in this study was obtained by transesterification from methanol and spent edible oils, and fulfills the requirements specified in EN 14214 standard. All the tests were conducted in a heavy diesel engine (ISUZU 4JJ1E4N). Two studies were carried out in this paper.

Diesel engines possess high energy efficiency as for power generation, and they have been used in commercial vehicles widely for a long time. Due to the coming shortage of fossil fuel in the near future and the impact of greenhouse gas effect in recent years, the types and quantities of diesel vehicles have grown year by year. However, smoke emission of diesel engine has always been an issue. Diesel smoke can be seen by eyes apparently, and it becomes an obvious pollution problem. Traditional diesel particulate filter (DPF) is the current solution to solve the problem of smoke emission currently. However, after using DPF for a certain period of time, the back pressure of engine will rise up and the engine performance will be affected because of the accumulation of soot particles. The soot particles must be removed. This process is the regeneration of DPF.