Low pressure injection of oxyhydrogen in turbocharged compression ignition engines

U radu se predlaže eksperimentalna analiza utjecaja primjene elektrolitičkog plina (oxyhydrogen gas) kao rezultata postupka elektrolize provedene na vozilu, u motoru s kompresijskim paljenjem. Eksperiment se sastoji od niza testova trajnog opterećenja (isti položaj akceleratora), na šasiji dinamometra, započinjući s uobičajenim gorivom (standardno gorivo za diesel motore), a u sljedećoj fazi uvodeći elektrolitički plin (plin kisika i vodika) kroz razdjelnik motora vozila, uz različite postotke volumena. Eksperimentalni podaci pokazuju pozitivan utjecaj dodanog elektrolitičkog plina na neprozirnost dimnog plina i porast NOx koncentracije. Mehanički parametri motora istaknuli su određene trendove, rezultirajući s definitivno korisnim obogaćujućim utjecajem elektrolitičkog plina.The paper proposes to analyse experimentally the influence of using oxyhydrogen gas, resulting from a process of electrolysis produced on board the vehicle, in supercharged compression ignition engine. The experiment consists in the series of the constant load tests (the same position of the accelerator), on the chassis dynamometer, initially starting with conventional fuel (standard diesel oil) and in the second phase by introducing the oxyhydrogen through engine manifold of the vehicle, with different volume percentages. The experimental data reveal a positive influence of the added oxyhydrogen on opacity of the flue gas and an increase of the NOx concentration. The mechanical parameters of the engine just highlighted certain trends, resulting in definitely the favourable enriching influence of oxyhydrogen

Smanjenje zagađenja okoliša izgaranjem mješavine biobutanola u pilot instalaciji za kogeneraciju toplinske i električne energije

Increasingly more, on the government agenda meetings is the environmental pollution caused by the large industrialists. In this category, a high percentage, are represented by the existing Power Plants. A new approach in reducing the environmental pollution is producing energy and heat trough cogeneration. At small scale, cogeneration with high efficiency can be achieved with reciprocating internal combustion engines. The following paper highlights the possibility of running a small scale cogeneration plant with reciprocating internal combustion diesel engine with biobutanol blends. Results regarding the efficiency, emissions and energy cost calculations are presented. Final conclusions and discussions are closing the paper.Zagađenje okoliša od strane velikih industrijskih postrojenja je sve češće na dnevnom redu vlada u čitavom svijetu. Veliki postotak ovih industrijskih postrojenja predstavljaju postojeće termocentrale. Novi pristup koji ima kao rezultat smanjenje zagađenja predstavlja kogeneracija toplinske i električne energije. U pilot instalaciji u laboratorijskim uvjetima kogeneracija sa visokim stupnjem iskorištenja može se postići s motorom s unutarnjim izgaranjem. Rad stavlja u prvi plan pilot instalaciju za kogeneraciju s dizel motorom i mješavinom biobutanola kao osnovnim gorivom. Rezultati su predstavljeni kroz stupanj iskorištenja, emisije štetnih plinova i proračun troškova. Na kraju rada su predstavljeni zaključci i završna diskusija

Thermodynamic analysis of gas turbine powered cogeneration systems

548-553This study proposes an integrated model for thermodynamic analysis of gas turbine powered cogeneration systems,covering simple cycle and overall cogeneration efficiency, load control by using inlet guide vanes, inlet fogging and supplementaryfiring. The model can be further developed for other applications (air cooling, steam injection, and trigeneration ofpower, heat and cooling)

Calculation of the Heat Transfer Coefficient for Laminar Flow in Pipes in Practical Engineering Applications

Paper presents an analysis of existing correlations for laminar liquid flow and heat transfer in tubes based on the published theoretical research and experimental data. Considering the relatively large deviation of existing correlations from the experimental data, the novel correlation for laminar heat transfer in tubes is proposed. The new correlation covers large range of tube diameters ranging from micro-scale level 125.4 mu m to conventional diameter 20.8 mm, Graetz numbers up to 6500 and fluid to wall viscosity ratio 0.0048-11.7. Correlation ratio of the newly proposed relationship for a total number of 390 experimental runs is 96.6% and standard deviation is 16.2%. Moreover, correlation covers both the hydraulically and thermally undeveloped and developed flows and all cases of boundary conditions that can be met in industrial applications.Peer-reviewed version of the article: [https://machinery.mas.bg.ac.rs/handle/123456789/3927

Sustainable development of Romanian cities through biogas production from municipal wastes and application in co-combustion processes

Today municipal wastes represent a general problem from multiple points of view: necessary space for depositing, odor, possible soil contamination. In the same time, a large quantity of organic residual material remains unused in terms of energy conversion by potentially producing a biofuel which, in its term, can be used for covering at least partially, the human demand for energy. In this context, the present paper underlines the possible applications of anaerobic fermentation for biogas production by using as main substrate solid municipal waste from city of Timisoara, Romania, inside a pilot installation for determining its potential for further usage at larger scale in firing or co-firing processes; in this context, conclusions will be traced, based on the resulted experiments