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- 实验方案
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In-flame soot quantification of diesel sprays under sooting/non-sooting critical conditions in an optical engine
摘要： Because of the challenge of meeting stringent emissions regulations for internal combustion engines, some advanced low temperature combustion modes have been raised in recent decades to improve combustion efficiency. Therefore, detailed understanding and capability for accurate prediction of in-flame soot processes under such low sooting conditions are becoming necessary. Nowadays, a lot of investigations have been carried out to quantify in-flame soot in Diesel sprays under high sooting conditions by means of different optical techniques. However, no information of soot quantification can be found for sooting/non-sooting critical conditions. In current study, the instantaneous soot production in a two-stroke optical engine under low sooting conditions has been measured by means of a Diffused back-illumination extinction technique (DBI) and two-color method (2C) simultaneously. The fuels used were n-dodecane and n-heptane, which have been injected separately though two different injectors equipped with single-hole nozzles. A large cycle-to-cycle variation on soot production can be observed under such operating conditions, however the in-cylinder heat release traces were quite repeatable. It is the same with the well-known trends of soot amount to operating conditions that the probability of sooting cycles increases with higher ambient temperature, higher ambient density and lower injection pressure. Both techniques present a pretty good agreement on soot amount when the peak of KL value is close to 1. However, the KL value of two-color method becomes bigger than that of DBI and the difference increases with lower sooting conditions.
关键词： 2C,Soot critical conditions,DBI,Diesel sprays,Optical engine
更新于2025-09-23 15:23:52
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[IEEE 2018 2nd School on Dynamics of Complex Networks and their Application in Intellectual Robotics (DCNAIR) - Saratov, Russia (2018.10.8-2018.10.10)] 2018 2nd School on Dynamics of Complex Networks and their Application in Intellectual Robotics (DCNAIR) - Autonomous Power Supply System of Magnetron Generators Group
摘要： The issues which emerge at autonomous power supply system development are considered. The objects of power supply are magnetron generators groups as part of technological complex with a distributed supply of microwave energy.
关键词： solar panels,wind generator,power supply system,diesel generator,magnetron
更新于2025-09-23 15:23:52
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Hydrogen Production from Residual Glycerol in Biodiesel Synthesis by Photocatalytic Reforming
摘要： Biodiesel (BDF) has gained much attention as new sustainable energy alternative to petroleum-based fuels. In particular, BDF market has significantly increased in Europe to adhere energy and climate policies. Therefore, the increased BDF production requires new utilization of glycerol which is by product of BDF synthesis. We have focused on photocatalytic reforming using titanium oxide (TiO2) photocatalyst using glycerol as sacrificial agent (SaH). Recently we have found that SaH with all of the carbon attached oxygen atoms such as glycerol and methanol continued to serve as an electron source until their sacrificial ability was exhausted in photocatalyzed hydrogen evolution using a Pt-loaded TiO2 (Pt/TiO2) catalyst. Here we investigated the utilization of residual glycerol in BDF synthesis by photocatalytic reforming.
关键词： Bio-diesel,Reforming,TiO2,Hydrogen,Photocatalyst,BDF
更新于2025-09-23 15:21:21
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The influence of the solar radiation database and the photovoltaic simulator on the sizing and economics of photovoltaic-diesel generators
摘要： This study evaluated the outcome differences when adopting five different solar irradiation databases on the sizing of hybrid solar photovoltaic-diesel generators designed to supply electricity to isolated minigrids. To do this, the two most widely adopted photovoltaic (PV) simulation packages in the market, namely PVsyst? and HOMER Energy? were used. The different origins, data timespan, space and time resolution, of the five most relevant solar irradiation databases available for the region were compared. A case study was presented to illustrate the influences of the solar irradiation database and the solar simulation tool on the resulting PV generator. Furthermore, the hourly behavior of the energy supply to an existing load in a minigrid in the Brazilian Amazon was evaluated, together with the savings in diesel obtained with the resulting PV generator. Evaluating the five options of solar radiation databases, for the same PV plant configuration, variations of up to 19.7% were found in the expectation of PV generation. When the simulation software package was varied, the combined effect (radiation database X PV system sizing tool) showed differences of up to 20.6%. This demonstrates that despite having different algorithms, computational tools have a small influence (less than 1%) on results. These combined differences, taking into account the load curve behavior and the total diesel generation capacity installed at the site, resulted in over 100% differences in the optimum PV generator size in the case study. The total savings in diesel fuel, over a 15-years period, ranged from $ 6.5 million to over $ 16 million (> 2.5 times) for the smallest PV system. This demonstrates the importance of the correct choice of database. These evaluations can be extended to minigrids of any size elsewhere. The novelty and originality of this study is to demonstrate and quantify for the first time the influence of the solar radiation database and the PV simulator package on the sizing of PV-diesel generators. The consequences of this study are not only of scientific and academic importance, but of economic and commercial interest as well.
关键词： Photovoltaic simulation tool,Hybrid photovoltaic-diesel power plant,Solar database,Minigrids,Solar irradiation
更新于2025-09-23 15:21:01
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Control methodology and implementation of a Z-source inverter for a stand-alone photovoltaic-diesel generator-energy storage system microgrid
摘要： This paper deals with the control and implementation of a bidirectional Z-source inverter for a photovoltaic-diesel generator-energy storage hybrid system. The proposed control strategy is based on the voltage regulation across one of the Z-network capacitor (Vcz), through a buck-boost converter of the storage system side. In some critical situations, where the load power is important, the Vcz voltage regulation is no longer able to ensure the duration of the necessary state shoot-through for the maximum power point tracking achievement. In this context, the diesel generator can therefore be solicited to ensure the shoot-through duration and achieve maximum power point tracking so that it can be used more advantageously without any harmful e?ects on the Z-source inverter operation. The e?ectiveness of the proposed control strategy is evaluated and validated by extensive simulations and experiments.
关键词： Energy maximum power point tracking (MPPT),Hybrid system,Microgrid,Photovoltaic generator,Z-source inverter,Diesel generator,Energy storage system
更新于2025-09-23 15:19:57
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Quantitative remote and on-site Hg2+ detection using the handheld smartphone based optical fiber fluorescence sensor (SOFFS)
摘要： Di-n-butyl ether (DBE) is one of the most promising alternative biofuels for vehicles due to its superior physicochemical properties and because it is a renewable resource. This study investigated the effects of DBE addition on the spray macroscopic characteristics of diesel-biodiesel blends under various injection and ambient conditions. Three kinds of ternary blended fuels were prepared—(1) 72% diesel, 18% biodiesel, 10% DBE by volume (D72B18DBE10); (2) 64% diesel, 16% biodiesel, 20% DBE by volume (D64B16DBE20); and (3) 56% diesel, 14% biodiesel, and 30% DBE by volume (D56B14DBE30)—in order to compare their spray characteristics with those of an 80% diesel–20% biodiesel mix (D80B20) and conventional diesel (D100). The experiments were conducted in a constant volume chamber with a high-pressure common rail injection system using a high-speed photography method. The results show that D80B20 gives the longest spray tip penetration and the smallest cone angle and projected area among the five test fuels. With increased DBE blending ratio, the spray penetration length decreases slightly, and spray cone angle and projected area increase. When the DBE volume fraction in the ternary blend is 20%, the spray tip penetration, cone angle, and projected area are comparable to those of diesel. In addition, air entrainment characteristics were analyzed with the quasi-steady jet theory. It was found that the addition of DBE can improve the air entrainment characteristics of diesel-biodiesel blends, and D64B16DBE20 results in fuel-air mixing similar to that of D100.
关键词： Biodiesel,Diesel,Di-n-butyl ether,Spray characteristics
更新于2025-09-19 17:13:59
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Coupled photothermal and joule-heating process for stable and efficient interfacial evaporation
摘要： A trade-off inevitably exists between soot and NOX emissions in a traditional engine. The addition of an oxygen-containing biofuel can decrease the soot emission but increase the NOX emission. Multi-injection strategy can be used to decrease the NOX emission. Therefore, both simulations and experimental tests were conducted to evaluate the influences of pre-injection on the combustion and emission characteristics of pure diesel (D100) and diesel/n-butanol (30% n-butanol and 70% diesel by volume, B30). The results showed that as the pre-injection interval decreased, the in-cylinder pressure peak increased, the pre-injection heat release ratio increased, and the brake-specific fuel consumption (BSFC) decreased. Only at a small pre-injection interval, the BSFC under pre-injection condition was lower than that obtained using the single injection strategy. When the same pre-injection strategy was used, B30 had a higher BSFC and lower brake thermal efficiency than D100. The soot emission decreased with the increase in pre-injection interval but increased with the increase in pre-injection ratio. More soot was emitted using the pre-injection strategy than that using single injection strategy. B30 had a lower soot emission than D100 due to a longer ignition delay. As the pre-injection interval increased, the decreasing amplitude of NO production became smaller than the increasing amplitude of NO2 production, thus increasing the net NOX emission. As the pre-injection ratio increased, more CO was produced through the reaction paths CH2O → HCO → CO, whereas the transformation of CO to CO2 almost remained unchanged, thus increasing the net CO emission. The increase in pre-injection ratio inhibited the oxidation of CO to CO2 and thus increased the CO emission. The amount of unburned hydrocarbons increased with the increase in both pre-injection ratio and interval.
关键词： Chemical kinetics,CFD,Pre-injection,Diesel/n-butanol blends,Low-temperature combustion
更新于2025-09-16 10:30:52
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[ACM Press the 4th International Conference - Moscow, Russian Federation (2018.06.25-2018.06.27)] Proceedings of the 4th International Conference on Frontiers of Educational Technologies - ICFET '18 - Implementation and Statistics of Photovoltaic (Pv) Diesel Hybrid Solar System In Commercial Buildings of Pakistan
摘要： Pakistan is well known developing country in the world with a population of around 200 Million [1] with annual growth of 2.61 % [1] in 2017 and the energy demand gap of electrical power generation is 4500 to 5500 MWH [2] due to which a lot of load shedding occurs to cover the shortfall of energy crisis. This trend of energy crisis should be overcome and reduce by promoting solar system which can be drive independently with the help of generator sets by PV diesel hybrid solution. Environmental to non- protection concerns are gradually conventional generation of power in the whole world. Renewable energy sources (RES) with advanced technology plays a vital role in that sustainable increasing energy demand and burning of natural resources such as fossils fuels, coal etc. in the context of such environmental issue [3]. The renewable energy sources such as solar PV system is eco-friendly and less maintenance electrical power generation technique which can be synchronize with generator set to minimize the consumption of gas or diesel in the generator or shutdown the one generator in peak hours of solar system to reduce the cost of fuels of generator such as gas, diesel and other resources and decrease the foot prints of carbon dioxide from the environment. In this research paper the 200 kWp PV diesel hybrid solar system in Dream world resort Karachi Pakistan has been analyzed. This paper provides the working principal of PV diesel hybrid system and the energy generation from simulation report and the online portal that is realistic energy generation at site and the reduction of carbon dioxide foot prints from the environment in comparison of different energy generation resources.
关键词： Energy,Generation,Hybrid,environment,Gensets,Green Energy,Carbondioxide,Photovoltaic,Diesel
更新于2025-09-12 10:27:22
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Assessment of the Carbon and Cost Savings of a Combined Diesel Generator, Solar Photovoltaic, and Flywheel Energy Storage Islanded Grid System
摘要： The use of diesel generators to provide power for islanded grids has been the technology of choice but they generate substantial carbon emissions unless the part or all the fuel comes from a renewable source. Notwithstanding this, the engine must be sized to meet maximum demand and will operate ine?ciently at part load most of the time, which is particularly bad for a synchronous constant speed engine. Given the availability of low cost solar photovoltaic (PV) systems, it is very enticing to ?t a diesel generator and allow the engine to be turned o? during PV generation. However, this combination will not work without some form of energy storage since it takes time for the engine to start, leading to gaps in supply and instability of the system. Lithium-ion batteries are typically considered to be the best solution to this problem because they have a high response rate, costs are lower, and they are available as products. However, they will su?er from the limited cycle and calendar life due to high cycling requirements in the application described. It is, therefore, proposed that a ?ywheel system could o?er a lower lifetime cost alternative since only short duration bridging power storage is needed and ?ywheels of appropriate design can o?er lower power cost than Lithium-ion battery systems. Flywheels are particularly attractive since they have a very high calendar with almost an in?nite cycle life and are fully recyclable at the end of life. This research, therefore, presents an assessment of the ?ywheel energy storage system (FESS) as an alternative to electrochemical batteries to supplement solar PV systems backed up by diesel generators. The model of an islanded PV system combined with a diesel generator and a FESS supplying power to a residential load is implemented in MATLAB/Simulink. The results of the analysis for the cases with and without storage based on a number of di?erent charge-discharge strategies provide evidence to support this hypothesis.
关键词： dynamic model,standalone hybrid system,solar photovoltaic system,backup diesel generator,flywheel energy storage
更新于2025-09-12 10:27:22
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Commercial-scale hybrid solar photovoltaic - diesel systems in select Arab countries with weak grids: An integrated appraisal
摘要： Solar photovoltaic (PV) diesel hybrid systems are effective solutions for sustainable energy transition in countries where utility grids are intermittent. An ‘integrated appraisal’ of ’hybrid solar (PV) - diesel’ systems are carried out to assess their overall energetic, environmental, financial and economic performances. The study carries out the analysis of hybridized solar photovoltaic energy using first-hand data and information collected from the Palestinian, Lebanese and Iraqi commercial and/or industrial sectors, adopting several scenarios of tariff and diesel fuel prices, capital costs assumptions, solar PV curtailment, and values for environmental damage adopted from life-cycle impact assessment methods that allow for monetization and are globally valid. Results show that hybrid PV-diesel systems have largely beneficial energy, environmental and economic performances in all three countries, whereas their financial performance are also positive for Palestine and Lebanon, however less promising in Iraq, mainly due Iraq’s heavily subsidized electricity tariff. The study concludes with policy recommendations focused on promoting solar PV in the commercial and/or industrial sectors, namely: the gradual phasing-out of fossil fuel subsidies, the effective execution of net-metering, the provision of subsidized sustainable energy loans, and carefully designed energy management systems.
关键词： Life-cycle assessment,Arab countries,Cost-benefit analysis,Hybrid solar PV-Diesel
更新于2025-09-12 10:27:22