107 research outputs found
Experimental Investigation and RSM Modeling of the Effects of Injection Timing on the Performance and NOx Emissions of a Micro-Cogeneration Unit Fueled with Biodiesel Blends
The (partial or total) substitution of petro-diesel with biodiesel in internal combustion engines (ICEs) could represent a crucial path towards the decarbonization of the energy sector. However, critical aspects are related to the controversial issue of the possible increase in Nitrogen Oxides (NOx) emissions. In such a framework, the proposed study aims at investigating the effects of biodiesel share and injection timing on the performance and NOx emissions of a diesel micro combined heat and power (CHP) system. An experimental campaign has been conducted considering the following operating conditions: (i) a reference standard injection timing (17.2° BTDC), an early injection timing (20.8° BTDC), and a late injection timing (12.2° BTDC); (ii) low (0.90 kW), partial (2.45 kW), and full (3.90 kW) output power load; and (iii) four fuel blends with different biodiesel (B) shares (B0, B15, B30, and B100). Experimental data were also elaborated on thanks to the response surface modelling (RSM) technique, aiming at (i) quantifying the influences of the above-listed variables and their trends on the responses, and (ii) obtaining a set of predictive numerical models that represent the basis for model-based design and optimization procedures. The results show: (i) an overall improvement of the engine performance due to the biodiesel presence in the fuel blend —in particular, B30 and B100 blends have shown peak values in both electrical (29%) and thermal efficiency (42%); (ii) the effective benefits of late SOI strategies on NOx emissions, quantified in an overall average NOx reduction of 27% for the early-to-late injection, and of 16% for the standard-to-late injection strategy. Moreover, it has emerged that the NOx-reduction capabilities of the late injection strategy decrease with higher biodiesel substitution rates; through the discussion of high-prediction-capable, parametric, data-driven models, an extensive RSM analysis has shown how the biodiesel share promotes an increase of NOx whenever it overcomes a calculated threshold that is proportional to the engine load (from about 66.5% to 85.7% of the biodiesel share)
Effect of non-surgical maxillary expansion on the nasal septum deviation: a systematic review
Hydro-liquefaction of woody biomass for bio-oil in supercritical solvent with [BMIM]Cl/NiCl2 catalyst
Vínculo entre enfermeiros e mães de crianças menores de dois anos: percepção de enfermeiros
Tooth whitening with hydrogen peroxide in adolescents: study protocol for a randomized controlled trial
Kinetic Characterization of the Residues from the Pruning of Apple Trees for their Use as Energy Vectors
Process analysis of an MCFC power plant fed with a biomass syngas
The coupling of renewable energy sources and innovative power generation technologies is of topical interest to meet demands for increased
power generation and cleaner environmental performance. Accordingly, biomass is receiving considerable attention as a partial substitute for fossil
fuels, as it is more environmentally friendly and provides a profitable way of disposing of waste. In addition, fuel cells are perceived as most
promising electrical power generation systems. Today, many plants combining these two concepts are under study; they differ in terms of biomass
type and/or power plant configuration. Even if the general feasibility of such applications has been demonstrated, there are still many associated
problems to be resolved. This study examines a plant configuration based on a molten carbonate fuel cell (MCFC) and a recirculated fluidized-bed
reactor which has been applied to the thermal conversion of many types of biomass. Process analysis is conducted by simulating the entire plant
using a commercial code. In particular, an energy assessment is studied by taking account of the energy requirements of auxiliary equipment and
the possibility of utilizing the exhaust gases for cogeneration
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