Vedelkütustest moodustatud küttesegu töötlemise süsteem sädesüütega mootorgeneraatorites kasutamiseks kriisi olukorras

A Thesis for applying for the degree of Doctor of Philosophy in Engineering Sciences.Väitekiri filosoofiadoktori kraadi taotlemiseks tehnikateaduse erialal.In times of crisis and war, there is a high probability that the operation of electrical networks will be disrupted, and therefore some distribution networks may remain without electricity. As a result, important information- and communication technology nodes of the core networks of the country's critical infrastructure are also without electricity. In a crisis situation, the missing electrical energy can be produced with widespread spark ignition engine-generators, but in their case, flexibility in the use of fuels is important. In a crisis situation, all possible engine fuels, both light and heavy, must be used. The problem with the use of engine-generators for the production of electricity is their single-fuel nature. By heating the fuel mixture, better evaporation is achieved and thus it is possible to bypass the problem and use all liquid fuels intended for internal combustion engines to produce electricity in a spark-ignition engine-generator. The dissertation is based on six articles. The research paper described the effects of EU and NATO legislative acts on the liquid fuels used in Estonia, analyzed solutions for solving problems related to energy security in Estonia, analyzed the bottlenecks in the use of diesel and biodiesel fuels in compression ignition engines, developed a technical solution for a air-fuel mixture processing system made from different fuels, and improved the solution so that it is suitable for use with spark ignition engine and engine experiments were performed. The aim of the work was to develop a air-fuel mixture processing system made of different liquid fuels for a spark-ignition engine, and its suitability in practice was assessed. The aim of the system is to adapt the air-fuel mixture for use in a spark-ignition engine in order to ensure the production of distributed electricity in times of crisis and war to support the country's critical infrastructure. The conducted research and the developed solution contribute to the production of distributed electricity with spark ignition engine-generator in a crisis or war situation, using currently available liquid fuel to supply the country's information systems with electricity until NATO Article 5 is triggered, if necessary.Kriisi- ja sõjaajal on suure tõenäosusega elektrivõrkude töö häiritud ja seetõttu võivad osad jaotusvõrgud jääda elektrita. Elektrita on sellest tulenevalt ka riigi kriitilise informatsiooni- ja kommunikatsiooni tehnoloogia infrastruktuuri tuumvõrkude olulised sõlmed. Kriisisituatsioonis saab puuduvat elektrienergiat toota laialtlevinud sädesüütega mootor-generaatoritega kuid nende puhul on oluline kütuste kasutamise paindlikkus. Kriisiolukorras tuleb kasutada kõiki võimalikke mootorikütuseid, nii kerge- kui raskekütuseid. Mootor-generaatorite kasutamisel elektrienergia tootmiseks on probleemiks nende ühekütuselisus. Küttesegu kuumutamisega saadakse parem aurustumine ja nii on võimalik mööduda probleemist ning kasutada sädesüütega mootor-generaatoris elektrienergia tootmiseks kõiki sisepõlemismootorile ettenähtud vedelkütuseid. Väitekiri on koostatud kuue artikli põhjal. Uurimustöös kirjeldati EL ja NATO seadusandlike aktide mõjud Eestis kasutatavatele vedelkütustele, analüüsiti lahendusi energiajulgeolekuga seotud probleemide lahendamisele Eestis, analüüsiti diisli- ja biodiislikütuste kasutamise kitsaskohti survesüütega mootorites, töötati välja erinevatest kütustest valmistatud küttesegu töötlemise süsteemi tehniline lahendus, lahendust täiendati nii, et see sobiks kasutamiseks sädesüütega mootoril ning teostati mootorikatsetused. Töö eesmärgiks oli töötada välja erinevatest vedelkütustest moodustatud küttesegu töötlemise süsteem sädesüütega mootorile ja hinnati selle sobivust praktikas. Süsteemi eesmärgiks on kohandada küttesegu sädesüütega mootoris kasutamiseks, et tagada kriisi- ja sõjaajal hajuseleketrienergia tootmine riigi kriitilise infrastruktuuri toetamiseks. Läbiviidud uuringud ja väljatöötatud lahendus aitavad kaasa kriisi- või sõjaolukorras sädesüütega mootor-generaatoriga hajutatud elektrienergia tootmisele, kasutades selleks hetkel kättesaadavat vedelkütust, et varustada elektriga riigi IKT süsteeme kuniks vajadusel käivitub NATO artikkel 5.Publication of this thesis is supported by Estonian University of Life Sciences and the Doctoral School of Energy and Geotechnology III and Estonian University of Life Sciences ASTRA project „Value-chain based bio-economy

Study on performance of compression engine operated by biodiesel fuel

The analysis of the performance of biofuel is aimed at evaluating the energy efficiency of operating the engine with the use of biodiesel fuel as function of the fuel’s composition and other physical-and-chemical parameters. The mathematical models and analysis techniques known to the authors do not take into account the effect that the use of different bio-diesel fuels has on the operation of the engine and, therefore, need refinement in terms of the mathematical expressions and empirical formulae that describe the physical processes taking place in the engine’s cylinders. The aim of the study is to improve the mathematical relations taking into consideration the physical-and-chemical parameters of different types of fuel. The research methods proposed in the article are based on step-by-step consideration of the mathematical models of processes that follow each other, with due account for their possible overlapping, which jointly have an effect on the engine’s output indices. The boundary conditions and parameter increments are pre-set in electronic work sheets. Thus, it becomes possible, using the refined mathematical model, to calculate the main performance indices of the diesel engine with due account for the changes in the physical-and-chemical parameters of the fuel. The novelty of the described approach is in the possibility, through the use of the refined model and taking into account the data on the composition of the fuel and the design and operation parameters of the engine, to calculate the indices that allow evaluating the efficiency of use of specific fuels in the internal combustion engine under consideration. In results, formulas for the calculation of the effective power of the engine, fresh air charge density, excess air factor, effective specific fuel consumption and combustion pressure have been developed. Combustion pressure modelling and experimental data is presented