Xinran Wang , Tie Li , Xinyi Zhou , Shuai Huang , Run Chen , Ping Yi , Yibin Lv , Yu Wang , Honghua Rao , Yanzhao Liu , Xiaodong Lv
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引用次数: 0
Abstract
How to reduce the exhaust NH3 and N2O emissions is very crucial for bridging the gap between the high greenhouse gas (GHG) reduction potential and the engineering application of ammonia engines with high ammonia energetic ratios (AER). In this study, experiments were conducted to explore how the diesel injection pressures and the split injections affect the characteristics of combustion, emissions, and thermal efficiency for the AER of 80 % in a LPDF (i.e., low-pressure injection ammonia-diesel dual-fuel) engine. As for the split injections, both the early first injection during the compression stroke and the postponed second injection after the top dead center (TDC) were detailed investigated. With the injection pressure of the pilot diesel increasing from 60 to 150 MPa, about 28 % reductions in the unburned NH3 and about 13 % reductions in the N2O are achieved. With the optimized split injections before the TDC, about 11 % reductions in the unburned NH3, 13 % reductions in N2O, and 1.1 % enhancements of the indicated thermal efficiency can be simultaneously achieved. For the split injections with the second injection after TDC, the exhaust temperature can be to some degree increased but result in more NH3 and N2O, alongside a decline in thermal efficiency. Numerical simulations show that the diesel spray targeting and mixture reactivity stratification can explain the mechanism behind the improved performance of the optimized split injections, suggesting the potential for further improvement by the co-optimization of diesel injection strategy and combustion chamber geometry for the LPDF operations with high AERs.
期刊介绍:
Applied Thermal Engineering disseminates novel research related to the design, development and demonstration of components, devices, equipment, technologies and systems involving thermal processes for the production, storage, utilization and conservation of energy, with a focus on engineering application.
The journal publishes high-quality and high-impact Original Research Articles, Review Articles, Short Communications and Letters to the Editor on cutting-edge innovations in research, and recent advances or issues of interest to the thermal engineering community.