Miroshnychenko D. Energy efficiency upgrading of pneumatic units created on the basis of vortex expansion machines

The dissertation is devoted to raising of the efficiency and reliability, determination of area of rational application of pneumatic units on the basis of vortex expansion machines. A parameter-oriented model, technique of experimental and numerical optimization study of a multithreaded vortex expansion machine with an external peripheral channel has been developed. Planned (using the experimental design theory) and carried out computational experiments, the results of which performed multi-objective optimization, have made it possible to find geometrics of flowing sections and their ratios, providing the maximum adiabatic (isentropic) efficiency of multithreaded vortex expansion machines with an external peripheral channel. The optimum values of the efficiency of the vortex double-stream machine with an external peripheral channel have been successfully increased by more than 15% (from 30% to more than 45%). The test facility for the study of vortex expansion machines of low power (up to 15 kW), an experimental model of the double-stream vortex expansion machine and the data measuring system of the test facility has been created. As a result of the experimental studies, the characteristics of the optimized flowing section were obtained. The results of experimental studies of the vortex expansion machine have verified the results of the computational experiment. As a result, the influence of geometrical and gas-dynamic parameters on the flow pattern in the flow path of vortex expansion machine with a peripheral channel was established. The most influential factors on machine efficiency are identified and the ranges of their variations are determined. The feasibility of using units based on vortex expansion machines with capacity up to 500 kW have been substantiated. Areas of their rational use with the basic criteria complexes, generally recognized in the theory and practice of turbomachines have been determined.