Diesel Combustion and Emission Using High Boost and High Injection Pressure in a Single Cylinder Engine(Effects of Boost Pressure and Timing Retardation on Thermal Efficiency and Exhaust Emissions)

Abstract

Heavy-duty diesel engines have adopted numerous technologies for clean emissions and low fuel consumption. Some are direct fuel injection combined with high injection pressure and adequate in-cylinder air motion, turbo-intercooler systems, and strong steel pistons. Using these technologies, diesel engines have achieved an extremely low CO 2 emission as a prime mover. However, heavy-duty diesel engines with even lower NOx and PM emission levels are anticipated. This study achieved high-boost and lean diesel combustion using a single cylinder engine that provides good engine performance and clean exhaust emission. The experiment was done under conditions of intake air quantity up to five times that of a naturally aspirated (NA) engine and 200 MPa injection pressure. The adopted pressure booster is an external supercharger that can control intake air temperature. In this engine, the maximum cylinder pressure was increased and new technologies were adopted, including a monotherm piston for endurance of P max = 30 MPa. Moreover, every engine part is newly designed. As the boost pressure increases, the rate of heat release resembles the injection rate and becomes sharper. The combustion and brake thermal efficiency are improved. This high boost and lean diesel combustion creates little smoke; ISCO and ISTHC without the ISNOx increase. It also yields good thermal efficiency.

Investigation of early soot formation process in a diesel spray flame via excitation—emission matrix using a multi-wavelength laser source

“…Smokeless diesel spray combustion based on a variety of approaches, such as low-temperature combustion [1][2][3], high-pressure fuel injection, and high boost charging [4], has been attracting growing attention as a potential technology to overcome ever-stringent emission regulations. In order to explore and enhance the potential of these emerging spray combustion technologies, especially when they are coupled with advanced aftertreatment technologies and model-based engine control strategies, detailed chemical and physical understanding of soot formation processes in the spray flame is becoming increasingly important.…”

Study on Spray Characteristics of Biodiesel using a Rapid Compression Machine

“…It is well known that the rapid compression machine (RCM) is an excellent tool to study the mixture formation and combustion process. RCM is an instrument designed to stimulate a single compression event of an engine cycle of internal combustion engine [6][7][8]. The influence of the injection process inside the combustion chamber has to be considered in the analysis of spray formation and propagation.…”