Development of a direct-injected natural gas engine system for heavy-duty vehicles: Final report phase 2

Cox, George B.; DelVecchio, K.A.; Hays, W.J.; Hiltner, Joel; Nagaraj, Raveendra; Emmer, Claus

doi:10.2172/753776

Cited by 6 publications

(2 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Natural gas has to be heated to temperatures of 0-60 • C [18] depending on engine requirements [77] and the temperature of the available heat source [75]. The type of vaporizer used also depends on the required natural gas pressure which, in turn, depends on the type of gas engine: Therefore, LNG vaporizers for mobile applications are typically shell-and-tube heat exchangers (STHX) [36,62,79,84,85], and depending on the fuel injection pressure, they enable either supercritical [79, 82,83] or subcritical [18,62,86] regasification. The effect of pressure on the regasification process is shown in Figure 25.…”

Section: Lng Regasification and Chosen Challenges Of Lng Two-phase Heat Exchangersmentioning

confidence: 99%

Liquefied Natural Gas in Mobile Applications—Opportunities and Challenges

et al. 2020

View full text Add to dashboard Cite

Liquefied natural gas (LNG) is one of the most influential fuels of the 21st century, especially in terms of the global economy. The demand for LNG is forecasted to reach 400 million tonnes by 2020, increasing up to 500 million tonnes in 2030. Due to its high mass and volumetric energy density, LNG is the perfect fuel for long-distance transport, as well as for use in mobile applications. It is also characterized by low levels of emissions, which is why it has been officially approved for use as a marine fuel in Emission Control Areas (ECAs) where stricter controls have been established to minimize the airborne emissions produced by ships. LNG is also an emerging fuel in heavy road and rail transport. As a cryogenic fuel that is characterized by a boiling temperature of about 120 K (−153 °C), LNG requires the special construction of cryogenic mobile installations to fulfill conflicting requirements, such as a robust mechanical construction and a low number of heat leaks to colder parts of the system under high safety standards. This paper provides a profound review of LNG applications in waterborne and land transport. Exemplary constructions of LNG engine supply systems are presented and discussed from the mechanical and thermodynamic points of view. Physical exergy recovery during LNG regasification is analyzed, and different methods of the process are both analytically and experimentally compared. The issues that surround two-phase flows and phase change processes in LNG regasification and recondensation are addressed, and technical solutions for boil-off gas recondensation are proposed. The paper also looks at the problems surrounding LNG installation data acquisition and control systems, concluding with a discussion of the impact of LNG technologies on future trends in low-emission transport.

show abstract

Section: Lng Regasification and Chosen Challenges Of Lng Two-phase Heat Exchangersmentioning

confidence: 99%

Liquefied Natural Gas in Mobile Applications—Opportunities and Challenges

et al. 2020

View full text Add to dashboard Cite

show abstract

“…A typical spark-ignition direct-injection (SIDI) engine consists of a high-pressure fuel pump, injector, and ECU, where the ECU controls the amount of fuel injection and injection parameters, such as injection pressure and injection time [186]. It was reported that DI CNGs had increased engine torque at all engine speeds compared to MPI CNGs, due to higher volumetric efficiency, enhanced in-cylinder flow motion, and improved combustion with faster flame propagation [187]. The direct injection of CNG offers advantages regarding power output, an extension of lean limit, and unburned hydrocarbon (UHC) emission levels; it also increases IMEP by between 9% and 15% of that generated by the manifold injection [188,189].…”

Section: Spark-ignition Direct-injection Enginesmentioning

confidence: 99%

Natural Gas Engine Technologies: Challenges and Energy Sustainability Issue

2018

View full text Add to dashboard Cite

Energy sustainability and environmental issues pose greater challenges on different primary energy sectors as the global energy demand increases and it is projected to further increase with an upsurge in population. On the other hand, energy sources from conventional fossil-based fuels are depleting, forcing explorations in challenging and difficult locations. As a result, the use of alternative fuels received dramatic consideration to substitute these conventional fuels, of which natural gas took the significant share. However, the share of natural-gas vehicles in the current vehicle market is quite small, and it is estimated to be below 5%. This paper reviews the current resource scenarios including proven and potential reserves, current production, and consumption, along with the fueling infrastructure, distribution, and storage. It also provides summary of the development of fuel-injection technologies aimed to enhance the performance of gas engines. More attention was also given to natural-gas engines and their limitations. Parameters affecting the performance and combustion of compressed natural gas (CNG) in spark-ignition (SI) engines are thoroughly assessed, among which compression ratio and injection timing play major roles in the optimization of CNG-fueled engines. Furthermore, different technologies that help close the performance gap between conventional liquid-fuel and natural-gas engines and future directions of the research are presented.

show abstract