Prototypowy silnik dwupaliwowy zasilany gazem CNG i olejem napędowym

Gaz naturalny obok ropy naftowej i węgla jest najważniejszym nośnikiem energii. Ma zastosowanie w energetyce i – coraz częściej – w motoryzacji. Silniki dwupaliwowe były i są obecnie przedmiotem badań głównie w aspekcie zastosowania do napędu pojazdów, zwłaszcza autobusów. W artykule zaprezentowano charakterystyki emisji adaptowanego silnika turbodoładowanego z chłodnicą powietrza doładowywanego i recyrkulacji spalin chłodzonych wodą do zasilania dwupaliwowego: CNG i ON

International combustion engine of 21. century

Przeprowadzono analizę termodynamiczną obiegu silnika spalinowego, z której wyciągnięto wnioski dotyczące potencjalnych możliwości jego dalszego ulepszenia w aspekcie sprawności i emisji. Głównym z nich jest zasilanie mieszankami ubogimi, w szczególności homogenicznymi, zarówno jeśli chodzi o silnik ZI jak i o ZS. Omówiono najistotniejsze problemy związane ze spalaniem mieszanek ubogich oraz zaprezentowano nowatorskie rozwiązania konstrukcyjne systemów spalania silników o bardzo małej emisji i wysokiej sprawności. Przedstawiono prognozy dotyczące rozwiązań konstrukcyjnych silnikówThermodynamic analysis of I.C. engine working-cycle has shown its potential capabilities of further development in view of economy and emissions. The engine, that will fulfil the demands of high efficiency and low emissions is thw engine (both S.I. and C.I.) fuelled with lean homogeneous mixtures. The technique of fuelling with lean homogeneous mixtures, especially these thermally/chemically activated and the effect of air fumigation on efficiency and emission is discussed. The features, with which the novel engine will be characterised are shown and discussed

HCCI engine - idea and expectations. Case study

Internal combustion engines yet have not exhausted their development possibilities in the range of economy and ecology demands. Development of SI and CI engines, which several years ago proceeded individually in-parallel, now becomes likely in common: one type of engine shares some features with the other one, e.g. direct injection, electronically controlled injectors, electronic control unit etc. However, type of ignition and mixture formation are still different (spark assisted ignition versus auto ignition and homogeneous mixture versus heterogeneous). HCCI engine overcomes this difference. At present HCCI engine uses both type of ignition modes and both types of mixture in different ranges of operational parameters. Direct injection during compression stroke and stratified charge are characteristics for low and mild power resulting in low emission of CO and HC as well as NOx. Combustion is initiated by spark when mixture is very poor. For maximum load and speed, auto-ignition of homogeneous stoichiometric mixture takes place in the whole volume of combustion chamber. Due to the absence of flame and low temperature, nitrogen oxides, of which molecules arise in post flame zone, are low. Also emission of CO and HC are low due to stoichiometry of the mixture. The key problem is controlled auto-ignition as a function of speed and load (fully HCCI engine). Several methods of auto-ignition control (CAI) are discussed in this paper

Compressed natural gas engines. A review

Resources, production, refuelling stations and physic-chemical properties of natural gas are presented. Technical problems connected with application of natural gas to SI and CI engines are shown and analyzed. Presently most of gas vehicles are converted from gasoline to natural gas application but also many companies produce gas vehicles driven with Sl engines originally fabricated as gas vehicles. However natural gas spark ignition engines have lower torque than CI engines normally used in trucks, pick-ups and busses. Therefore CI engines are also adapted to gas fuelling as dual-fuel engines. Comparison of NG SI engines and dual-fuel engines is performed. Performances and emissions of gas automotive engines are presented. World natural gas reserves, natural gas production physical and chemical properties of typical natural gas, natural gas vehicles and refuelling stations in the world, schematic of CNG fuelling installation of IVth and Vth generation, combustion system, natural gas admission and control in DF NG engine, schematic of ADCR engine adapted to CNG fuelling are presented in the paper

Natural gas engines - problems and challenges

At former KONES one of the co-authors presented a paper, is which general information about natural gas properties, reserves, production and distribution were given and application to SI and CI engines was presented, compared and discussed. It was shown, that more promising is dual-fuel CI engine. There is a lot of information on combustion, emissions and performances of dual-fuel natural gas engines, but there are also blank areas and controversial opinions, which were pointed out and discussed in this paper. For example: why combustion processes are delayed in comparison with combustion of diesel fuel only. It is also not clear whether noise of dual-fuel engine is higher than that of diesel engine or lower (there are contradictory data). These problems are shown and discussed in this paper. The proposal of further research is presented. Ignition and combustion in dual-fuel natural gas engines is yet not fully recognized, especially: combustion duration, mechanism at gaseous and condensed phase burning, kinetics and diffusion controlled combustion, noise, knock and cycle-by-cycle variation. Optimization of control parameters on account of efficiency and emissions is still an open problem. Influence of natural gas composition and its changes on engine performance and emissions still demand estimation

The condition and perspectives of development of organic farming in the Lubuskie province

Celem artykułu jest przedstawienie rozwoju rolnictwa ekologicznego w województwie lubuskim, które nabrało szczególnego znaczenia po akcesji Polski do UE. Rolnictwo ekologiczne stanowi jeden z najszybciej rozwijających się segmentów produkcji rolniczej w UE. Dokonano oceny poziomu produkcji ekologicznej w regionie lubuskim. Zaprezentowano kierunki i tempo zmian w wielkości i strukturze tej grupy gospodarstw. Wykazano znaczenie czynników makroekonomicznych na rozwój produkcji ekologicznej rolnictwa. Badania dotyczyły lat 2005-2015.The aim of this article is to present the development of organic farming in the lubuskie province, which took on special significance after the Polish accession to the European Union. Organic farming is one of the fastest growing models of management in agricultural production. Conducted levels of organic production in the region Lubuskie. Presented direction and pace of change in the size and structure of this group of households. It has been shown the importance of macroeconomic factors on the development of ecological agriculture. Researches were carried for years 2005-2015