Iskanje po katalogu digitalne knjižnice

Opis: In this paper bioethanol/diesel and bioethanol/biodiesel blends, at several concentrations and temperatures, are studied to find its possible commercial usage as a fuel to run a diesel power plant. The tested fuels were: net mineral diesel fuel (D100) , 5 % bioethanol/diesel fuel blend (v/v) (E5D95), 10 % bioethanol/diesel fuel blend (v/v) (E10D90), 15 % bioethanol/diesel fuel blend (v/v) (E15D85), neat biodiesel (B100), 5 % bioethanol/biodiesel blend (v/v) (E5B95), 10 % bioethanol/biodiesel blend (v/v) (E10B90), and 15 % bioethanol/biodiesel blend (v/v) (E15B85). The fuels were tested at: 30, 25, 8and -18 C. This paper shows the observations done in 8 samples during 5 weeks. After each week, each sample was overviewed, and changes related to stability, colour and aggregation were recorded. It has been proved that additives are not necessary to ensure stability of bioethanol/biodiesel blends under low temperature conditions, as the phase separation never happens.But in case of bioethanol/diesel blends some additives are necessary to keep stability under low temperature conditions. Based on this study, it can be concluded that blends of biodiesel fuel with bioethanol up to 15% can be used to fuel a diesel power plant if engine performance tests corroborate it. The same conclusion can be applied to blends of diesel fuel with bioethanol up to 15% blends if additives to keep stability are added.
Ključne besede: alternative fuel, biodiesel, bioethanol, heat engines, fuels blend
Objavljeno v DKUM: 31.05.2012; Ogledov: 2554; Prenosov: 0

Opis: This paper deals with the investigation of the influential parameters of a mathematical spray breakup model using different fuels. Beside injection system measurements, fuel physical properties and injection process characteristics were measured, because they are necessary for the spray simulation input. For validation purposes, spray was injected into motionless air at atmospheric pressure and room temperature and filmed with a high-speed camera. Spray macrocharacteristics have been determined on the recorded images. Using the simulation program, the injection processes for diesel, biodiesel, and their 50% blend B50 have been simulated. Spray mathematical model parameters were tuned based on the experimentally gained results. Primary breakup model parameters showed the biggest impact on the spray characteristics and were therefore expressed using the fuel physical properties, the injection process characteristics, and the working regime parameters. Spray simulations into the combustion chamber were made in the end. All of these results are presented and discussed in this paper.
Ključne besede: fuel spray, spray breakup, biodiesel fuel, fuels, numerical simulations, mathematical model
Objavljeno v DKUM: 31.05.2012; Ogledov: 1952; Prenosov: 88
Povezava na celotno besedilo

Opis: The transport in many countries is the most significant source for NOx and particulate matter (PM) emissions. Therefore, the possibility of reducing NOx and PM emissions is experimentally investigated using biodiesel and some of its blends with mineral diesel. Attention is focused on the optimal bus dieselengine adjustments for each tested fuel. The obtained engine characteristics are compared to each other by considering the 13 modes of the European stationary cycle test. The optimal injection pump timings are determined with the aim of reducing harmful emissions, while keeping other engine characteristics within acceptable limits. The optimal fuel blend is suggested, and the harmful emissions (NOx, PM, CO, unburned hydrocarbon, and smoke) reduction is estimated.
Ključne besede: internal combustion engine, NOx emissions, biodiesel fuel
Objavljeno v DKUM: 31.05.2012; Ogledov: 2304; Prenosov: 63
Povezava na celotno besedilo

Opis: This paper deals with injection characteristics using different fuels at different fuel temperatures. The fuels under consideration are neat biodiesel from rapeseed oil and some blends with diesel as well as neat mineral diesel D2. The fuel and fuel temperature influences are investigated experimentally in the mechanically controlled diesel fuel injection M system. At first, attention is focused on the injection characteristics, especially on fuelling, mean injection rate, mean injection pressure, injection timing, injection delay, and injection duration, which influence the most important engine characteristics. Furthermore, the influence of fuel temperature is investigated. On the basis of the measurements of pressure drop through the fuel filter, the minimum fuel temperature for safe engine operation is determined.
Ključne besede: internal combustion engines, fuel blends, biodiesel fuel, temperature influence, injection characteristics
Objavljeno v DKUM: 31.05.2012; Ogledov: 1840; Prenosov: 106
Povezava na celotno besedilo

Opis: This paper discusses the influence of biodiesel on output characteristics of adiesel engine and optimal timing setup for its injection pump. The influence of biodiesel is studied by running experiments on an NA diesel bus engine MAN D2 2566 with a direct-injection M system. The fuel used is biodiesel produced from rapeseed. Special attention is focused on the determination of the optimal injection-pump timing with respect to engine harmful emissions, enginefuel consumption, and other engine performance parameters. These engine characteristics are compared against those obtained using conventional D2 diesel. Experiments with biodiesel and D2 are run on several engine operating regimes. The engine was monitored for possible operation problems and carefully examined after the tests. The results obtained are presented and analyzed. It is shown that with carefully optimized timing of the pump, the harmful emission of NOx, smoke, HC, and CO can be reduced essentially by keeping other engine characteristics within acceptable limits.
Ključne besede: internal combustion engines, diesel engines, fuel injection, biodiesel fuel, engine characeristics
Objavljeno v DKUM: 31.05.2012; Ogledov: 2898; Prenosov: 189
Povezava na celotno besedilo