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Сформована математична модель процесу термічної утилізації гумо-технічних відходів за технологією багатоконтурного циркуляційного піролізу, яка включає повний механізм деструк-ції та кінетику паралельно-послідовних реак-цій піролізу. Запропонована модель дозволяє роз-рахувати концентрації отриманих продуктів деструкції, а відтак дає можливість наближе-но визначити склад цільових кінцевих продуктів. Застосування даної моделі необхідне при опти-мізації температурних режимів устаткування Article [3] introduced a method for the production of pylolysis oil from used automobile tires, based on the effect of microwave oven. The properties of the resulting alternative fuel, which is suitable for the diesel engine, were explored. Results of the study showed that heat-generating capacity of the resulting liquid fuel is 40.4 MJ/kg. The paper does not provide other characteristics compared to traditional diesel fuel, which does not allow us to talk about the high potential of fuel replacement.In the study [4], a new approach to a heating system with the use of liquid products of pyrolysis of waste tires was presented. Fuel properties of pyrolysis liquids, such as density, viscosity, the content of carbon and hydrogen, are almost comparable with commercial automobile diesel fuels. The problem is the high sulfur content and the lower flash point.Authors [5] considered pyrolysis of worn tires with an immobile layer in the reactor with vacuum and with the use of catalytic additives, such as Na 2 CO 3 , NaOH. As a result of the performed studies, they draw a conclusion on the feasibility of using NaOH as it is possible to achieve a decrease in the temperature of the process without changing the output of the liquid fraction (pyrolysis oil). The use of Na 2 CO 3 did not essentially change the course of the reaction. It was proved that vacuum pyrolysis has advantages over atmospheric pyrolysis.Scientists in paper [6] examined properties of the liquid fraction, obtained as a result of pyrolysis of worn tires, compared with diesel fuel. As a result, they made conclusions about the possibility of subsequent use of pyrolysis oil because its properties are similar to those of diesel fuel and are able to replace it in a small engine. Certain mixtures were taken for examination, and it was defined in conclusion that the mixture DTPO 25 demonstrated better results than DTPO 50 and DTRO 75.Article [7] proposed a number of engineering solutions to intensify the process of pyrolysis of shredded tires by the technology EnresTec Inc. (Taiwan). A special feature of this method of recycling is the postcombustion of tailgas with vapor wastes. Paper [8] shows the heat and mass exchange balances and calculations for enhancing energy efficiency and economic component. Calculation-analytical substantiations are undoubtedly an important contribution into the study of thermal processes of recycling worn tires. However, the main results of these studies are determining the quantitative characteristics of finished products. The composition and quality o...

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This work relates to the energy industry, in particular, complements the existing knowledge about a problem of increasing the overall efficiency of a centrifugal compressor stage by improving the geometric parameters of an impeller. The design features of the centrifugal compressors are analysed and the issues of their general modelling are considered in the article. The aim of the work is to increase the efficiency of the centrifugal compressor stage by improving the method of thermogasdynamic calculation with an extended determination of the number of its thermogasdynamic gas parameters and subsequent optimization of the design parameters of the impeller blades. This goal is achieved by solving the following problems: a) development of a model of the centrifugal compressor stage based on a method of thermogasdynamic calculation; b) study of the influence of the geometric parameters of the impeller and a diffuser on the components of gas velocities; c) improvement of the design methodology by optimizing the number of impeller blades, their thickness and angle of inclination to increase the efficiency of the stage. The most significant scientific results of the work are the construction method and the model of the centrifugal compressor stage, which allow taking into account real thermogasdynamic gas processes and calculating the geometric parameters of the impeller blades that are optimal in terms of efficiency.