Advanced Internal Combustion Research Articles

Advanced combustion strategies for improving ic engine efficiency and emissions

The growing need for higher fuel efficiency and compliance with increasingly stringent emission regulations has prompted significant advancements in internal combustion (IC) engine technology. Traditional combustion methods, while widely utilized, face inherent challenges such as limited thermal efficiency and the production of harmful emissions like nitrogen oxides (NOx), particulate matter (PM), carbon monoxide (CO), and unburned hydrocarbons (HC). To address these concerns, researchers and engineers have developed a range of advanced combustion strategies that offer the potential to drastically improve engine efficiency while minimizing environmental impact.This paper provides a comprehensive analysis of cutting-edge combustion techniques, with a focus on strategies that balance the trade-off between fuel efficiency and emission reduction. Prominent among these strategies is Homogeneous Charge Compression Ignition (HCCI), which utilizes a lean, premixed air-fuel mixture to achieve spontaneous ignition at low temperatures, significantly reducing NOx and PM emissions. Another promising technique, Reactivity-Controlled Compression Ignition (RCCI), leverages the controlled use of two fuels with different reactivity levels, enabling precise control over the combustion process and enhancing both fuel efficiency and emission control. In contrast, Gasoline Direct Injection (GDI) technology improves fuel atomization and combustion control by injecting fuel directly into the combustion chamber, leading to higher efficiency and power output, albeit with challenges related to particulate emissions.In addition to these combustion strategies, this paper explores the role of Low-Temperature Combustion (LTC), which operates at reduced in-cylinder temperatures to mitigate the formation of NOx and soot, as well as the potential of advanced ignition systems like plasma or laser-based ignition to improve lean-burn combustion processes. Furthermore, the paper examines the integration of renewable fuels, such as hydrogen and biofuels, with advanced combustion techniques to support the global transition toward cleaner energy.The analysis also considers technological enablers such as variable valve timing (VVT), turbocharging, and sophisticated exhaust after-treatment systems that complement these advanced combustion strategies. Moreover, the application of simulation and optimization tools, including computational fluid dynamics (CFD) and machine learning (ML), is highlighted as essential for refining engine design and optimizing combustion processes.Despite the notable progress, challenges remain in terms of system complexity, control precision, and expanding the operational range of these advanced combustion techniques. As the automotive industry moves towards electrification and hybridization, advanced IC engine combustion strategies will continue to play a crucial role in improving vehicle performance and sustainability. This paper concludes by outlining the future prospects for further optimizing combustion efficiency and integrating renewable fuels in next-generation IC engines, thereby contributing to a cleaner, more efficient transportation sector.

Cooling, Heating, and Power (CHP) for Commercial Buildings Benefits Analysis

ABSTRACT We performed a detailed analysis of the energy consumption and end-user economics combined heat and power (CHP) systems in largecommercial buildings that included: Five generation technologies (standard and advanced microturbines, standard and advanced internal combustion (IC) engines, and high-temperature PEM fuel cells); Three building types (hospital, large office, and large hotel); Five US cities (New York, Los Angeles, Chicago, Miami, and Phoenix); and Utilizing recovered heat for both heating and absorption cooling. Our detailed, hour-by-hour analysis includes a novel operating algorithm that makes the generate-versus-buy decision based on minimizing overall operating costs, including accounting for the impacts of electric demand charges. Our analysis did not consider benefits beyond end-user energy-cost savings, such as improved power quality/reliability, transmission and distribution system (T&D) support, and possibly emissions credits. This is an important limitation as these other benef...

Efficiency versus cost of alternative fuels from renewable resources: outlining decision parameters

In the discussion of traditional versus renewable energies and alternatives to conventional crude oil-based fuels in the transportation sector, efficiency calculations are but one decision making parameter. Comparing the assets and liabilities of fossil-based and renewable fuels in the transportation sector, further aspects such as centralized versus decentralized technologies, cost evaluations, taxation, and ecological/social benefits have to be taken into account. This paper outlines the driving parameters for shifting toward alternative fuels based on fossil or renewable resources and their use in innovative vehicle technologies such as advanced internal combustion and fuel cell electric drive systems. For the decision in favor or against an alternative fuel to be introduced to the mass market, automotive technologies and the energy supply system have to be examined in an integrated way. From an economic and technological perspective, some fuels may be even incompatible with the trend toward using renewable resources that have advantages in decentralized systems. Beyond efficiency calculations, political and industrial interests arise and may be influential to reshaping our currently crude oil-based mobility sector.