At the present stage of social development, the need for rational use of energy resources of the planet is particularly acute. Most countries have already faced the problem of the energy crisis. An appropriate way to solve this problem is the utilization of secondary energy resources. With the help of turbine generators, it is possible to reduce the pressure and utilize the potential energy of excess pressure of gas or vapours to produce electricity. Such units can be created based on a jet reaction turbine. The study aims to assess the impact of the degree of off-design of the traction nozzle on the efficiency of the jet reactive turbine. The analysis of the factors influencing the efficiency of the jet reaction turbine is carried out in the work. The obtained efficiency rate for the jet reactive turbine depending on the given dimensionless velocity of λout t at the inlet pressure of the inlet nozzle of 2, 4, 6 and 10 MPa in the design mode (at the degree of off-design of S = 1) and in the off-design modes of operation ( S> 1). Graphical dependencies of the jet reaction turbine efficiency rate on the given circular velocity of the impeller are constructed (U− = 0… 0.7). The research shows that with increasing pressure at the inlet to the inlet nozzle, the efficiency rate of the turbine increases, and the optimum of the efficiency rate is shifted towards the increase of the given circular velocity of the impeller, both in the design and off-design operating modes. It is found that the greatest value of the efficiency rate is acquired at the design mode of operation of the traction nozzle, i.e. at S = 1.

At gas distribution stations, a large amount of energy of compressed gases is lost. In such cases, the useful power is obtained with the aid of a turboexpander. The problem is that there is a great need for turboexpanders with a capacity of up to 500-700 kW. For these capacities, the turboexpander with the use of classical turbines turns out to be high-speed, complex, expensive, with a payback period that is more than two years. The solution of this problem is seen in the creation of turboexpander installations based on vortex machines. A promising type of vortex expansion machines are side channel machines. Results of studies of vortex hydraulic turbines with side channel showed high values of the efficiency. The goal of this research is study of the working process of vortex expansion machine with side channel by performing a computational experiment in the ANSYS CFX software package. The results of the research showed that the efficiency of vortex expansion machine with side channel is greater than in vortex expansion machine with peripheral channel (real experiment).

Vortex compressing machines (VC), viz., compressors, vacuum compressors, vacuum pumps, etc., possess the merits of dynamic machines [absence of complicated kinematic and friction couples, reliability, safety, long service life, "dry" flowthrough part (casing), relatively small size and weight, etc.] and of positive-displacement machines [ability to develop high heads at low outputs (capacities)]. These compressors are distinguished by simple design, technological effectiveness (adaptability to manufacture), low manufacturing cost, serviceability, minimum operational cost, stability, steady characteristics in the whole range of variation in operating conditions, in particular, absence of stalling and surging typical of centrifugal compressors, and so on. Maximum efficiency of a VC is attained at a relatively low rotation speed and peripheral rotor speed, which makes it possible to make them without boosters.Vortex compressors (VC) are well researched [1][2][3][4][5][6][7][8][9]. The best known work is [10] where theoretical hypotheses about the operating process of VCs are reviewed, experimental data are summarized and analyzed, and a procedure for calculating geometric parameters and operating conditions of a single-stage VC, making use of regenerative hypothesis, is given. It is indicated there as well that the characteristics of the stage may also be calculated for variation (with a definite step) in the flow factor.Vortex compressors find application in the domain of relatively low outputs (capacities) and high heads (the head factor of a VC in the rated operating conditions may be > 2), where they successfully compete with centrifugal compressors and compressors of the rotor type, especially of the type of liquid-packed ring, gear, and other compressors. In terms of energy conversion method, VCs are dynamic type of machines: gas particles in the flow-through part move in a spiral-like path from the inlet to the outlet of the machine, repeatedly interacting with the impeller vanes and gradually receiving energy from the impeller. This longitudinal-vortex flow is the primary flow with the energy being exchanged between the VC vanes and the gas particles in the casing channel; the flow intensity is geatly influenced by the type of the flow-through part and the geometric parameters that characterize both the stage as a whole (ratio of the diameter of the flow-through part to the diameter of the VC, ratio of the area of the inlet/outlet pipe to the area of the flow-through part, and so on) and its individual elements (angles of mounting and inclination, number of vanes of the VC, angles of inclination of the inlet and outlet pipe, etc.).A distinctive feature of the operating process of a vortex compressor (VC) is transfer of a part of the working medium through the cutoff device from the outlet to the inlet of the stage, which causes (especially when working with a compressible medium) further energy loss, lowering of efficiency of the machine as a result of mixing and change in the thermodynamic state of the str...

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