Kolbasenko O. Improving the technical, economic, environmental efficiency and reliability of boiler installations by means of activating the combustion of water-fuel emulsions

The results of research into the combustion of water-fuel emulsion are presented in the dissertation, as well as practical recommendations for improving the technology of its use in combustion chambers of boiler installations that have been developed. The object of the study is the physicochemical processes that occur during the combustion of water-fuel emulsions in the combustion chambers of boiler installations. The subject of the study is the patterns that characterize the process of burning water-fuel emulsions and their influence on the efficiency, environmental friendliness and reliability of the operation of boiler installations. The objective of the dissertation is scientific development of the theoretical basis and practical solutions to improve the technical, economic, environmental performance and reliability of boiler installations when using water-fuel emulsions. The introduction demonstrates the relevance of the topic of the dissertation, defines the research objectives, provides data on its scientific originality, practical significance, testing of the results, and publications made on the topic of the work. The first chapter presents an analysis of sources of information on the use of water-fuel emulsions in engines, gas turbines, and boiler installations. Factors affecting the combustion process of water-fuel emulsions are analyzed in comparison with traditional methods of improving the quality of combustion, such as injecting steam or introducing water into the combustion zone. The influence of water quality on the efficiency of power generating installations and methods of its preparation are analyzed, and the need for additional measures to activate work processes, including cavitation processing at the stage of preparation of the water-fuel emulsions, is shown. The lack of complete information on determining water quality requirements for water-fuel emulsions and work processes parameters when burning emulsion under conditions of different water content is pointed out. In the second chapter, the processes of vibrational combustion and their influence on the combustion of water-fuel emulsion are examined. Different types of vibrational combustion and their mathematical description are considered. The conditions under which a positive effect of such combustion mode on the intensification of heat transfer and the reduction of harmful emissions into the environment is observed are determined. Various processes of transformation of the water phase of the water-fuel emulsions are analyzed, each of which is accompanied by different patterns of fragmentation of the initial fuel droplets. The third chapter is devoted to the study of the phenomenon of high- and low-temperature corrosion during the combustion of water-fuel emulsions. A description of the experimental setup and the results of studies of the influence of the mineral part of the fuel and water during the combustion of water-fuel emulsions, as well as of the metal surface temperature and the excess air coefficient at different water salinity for steel 20 and 1X18N10T, are presented. A comparative analysis of the consumption of water-fuel emulsions and heavy fuel oil was conducted, and the dependences of the rate of high-temperature and low-temperature corrosion at different salt content and excess air coefficient were obtained. On the basis of processing the results of experimental studies, regression equations were obtained that allow predicting the intensity of corrosion when using water-fuel emulsions and pure fuels, and an assessment of the errors of the obtained equations was carried out. In the fourth chapter design solutions for industrial and waste-to-energy boilers equipped with the condensing heating surfaces made of various materials are proposed. The use of scrubber technologies that envision condensation surfaces with a nozzle made of non-corrosive materials is proposed. For ship boiler installations, the use of electrodialysis technologies for water preparation is substantiated, and the advantage of their use is shown. A scheme of the technology for the integrated use of fuel, energy and water resources has been developed, the feature of which is the use of cavitation processing of various levels of intensity at all stages of preliminary preparation of fresh water and fuel. An analysis of the influence of water vapor injection on the emission of harmful substances during the combustion of water-fuel emulsions in comparison with pure fuel was carried out. Using statistical data processing methods, multivariate regression equations were obtained, which allows determining the rate of increase in pollutants for the combustion of water-fuel emulsions with a sulfur content of up to 30%. In the conclusions, the main results of the scientific work regarding the solution of the scientific problems set in the research are presented.