A thesis for the degree of Doctor of Technical Sciences in specialty 05.05.03 – Engines and Power Plants. – Admiral Makarov National University of Shipbuilding, Ministry of Education and Science of Ukraine, Mykolaiv, 2021.
The dissertation is devoted to the solution of an important scientific and applied problem of increasing the efficiency of using the energy potential of compressed working fluid by rational organization of the working process of potential energy converting into mechanical work, namely, ensuring the increase in the expansion completeness, reducing the reverse compression and gas-dynamic losses of the working fluid in the volumetric machines in power plants based on them. In the course of the study, the analysis and systematization of the design features, the principle of operation and the areas of application of various types of serial machines of volumetric and dynamic action, as well as possible alternative ma-chines of volumetric action and constructive ideological solutions in them were carried out. A number of operational advantages and disadvantages of their use in various industries are highlighted.
An experimental power plant was developed on the basis of a prototype of a rotary-piston positive displacement engine with hinge-cam motion mechanism, as well as a re-search program. The regularities of changes in the energy and economic indicators of the operation of a rotary-piston engine with hinge-cam motion mechanism were experimentally determined, and the effect on them of the operating parameters of the engine (speed and working pressure) and regulation of the duration of the filling process was investigated.
A mathematical model has been developed for calculating the working cycle of a rotary piston positive displacement engine with hinge-cam motion mechanism, which involves taking into account the influence of the features of the combination of the advantages of organizing the working process of rotary and piston engines due to the design of the movement and gas exchange mechanism.
The analysis and generalization of the results of the study of the efficiency of using positive displacement rotary-piston engines with hinge-cam motion mechanism in existing and prospective power plants for various purposes are carried out.
Based on the results of scientific and technical research, a concept has been developed to improve the efficiency of converting low-potential energy of a compressed working fluid into mechanical work of positive displacement machines by combining the advantages of organizing the working process of rotary and reciprocating engines, namely by ensuring regulation of the beginning and duration of the filling process, increasing the completeness of expansion of the working fluid and a decrease in dead volume and gas-dynamic losses during gas exchange, which is realized through the use of new design solutions for the movement and gas exchange mechanism in the form of hinge-cam motion mechanism. This made it possible to reduce the specific gravity by 17...50 %, increase the ratio of the starting torque to the nominal torque by 11 %, and reduce the specific consumption of the working fluid by 15...24 % compared to serial piston displacement machines with spool valve timing and crank connecting rod motion mechanism.
The scientific significance of the obtained results lies in the development of the foundations and principles of converting low-potential energy of the compressed working fluid into mechanical work by combining the features and advantages of organizing the working process of various types of engines, which is the theoretical basis for implementing the concept of increasing the efficiency of volumetric machines.
The practical significance lies in the newly developed and scientifically grounded foundations for the design and creation of highly efficient rotary-piston positive displacement engines with hinge-cam motion mechanism, as well as power plants for various purposes based on them, which is essential for the development of industry. The results obtained are the theoretical basis for further scientific research of various power plants based on rotary piston engines, technical improvement and energy efficiency increase, and the developed general foundations for the design of rotary piston engines make it possible to create highly efficient engines for various purposes.
