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Increase of power and complication of turbomachinery design is accompanied by stricter requirements to their reliability. Increasing the service life of turbomachinery is also one of the main tasks of quality improvement. Since the blade is a highly loaded element of any turbomachine, high operational requirements are imposed on it, expressed in reliability and durability of this element. A large number of factors affect the performance of the blade, one of which is its twist. The purpose of the current study is to determine the effect of twist of a gas turbine blade twisted according to the potential vortex law.The results of research of twist law influence on stress-strain state of the blade of the last stage of axial gas turbine, twisted according to the potential vortex laware presented. For this purpose, using the internal packages Ansys, CFX and Static Structural, we performed an interdisciplinary conjugate analysis of the solutions of the computational gas dynamics and static strength problems. During the analysis of the static strength problem we considered the tensile stresses arising in the field of centrifugal forces, bending stress (in different planes — from the pressure difference between inlet and outlet and from the pressure difference on the concave and convex surfaces of the blade), torsional stress, as well as thermal stress.Evaluation of the obtained results in conjunction with the analysis of previously derived analytical dependencies allowed to establish the influence of blade twist on the stress-strain state. The factor of torsion stresses and deformations should be taken into account when designing twisted blades and their subsequent gas-dynamic and strength estimation.

The article is dedicated to the study of the feasibility of increasing the efficiency, reliability and manufacturability of existing gas turbine power plants with additive technologies that allow creating recuperators with regeneration degrees of 90...95%. The characteristics are presented for the following gas turbine power plants: TEEDA (Iran) 3.13 MW, ODK Perm Motors GTU-4P (Russia) 4.13 MW, Siemens SGT-100 (Germany) 5.1 MW, Solar Turbines Taurus 60 (USA) 5.67 MW. The research was carried out using the methods and programs of the Higher School of Power Engineering for the calculation of thermal circuits of GTPP. The dependences of effective efficiency, work ratio, effective specific work and specific consumption of conventional fuel of GTPPs under examination on compressor pressure ratio and regeneration factor are obtained. Solving the problem of increasing the regeneration factor in GTPP (above 0.9) requires the development of special designs of heat exchanger matrices of the recuperator, which is only possible with the use of additive technologies and new heat-resistant materials. Promising recuperators have a more complex design of heat exchange matrices, which ensures their being very compact. Such technical solutions can ensure the development and creation of fundamentally new designs of GTPP heat exchangers and significantly improve their technical characteristics.

The control of electrical insulation resistance is one of the important parameters characterizing the reliability of the ship's electric power system and the safety of its operation. A significant part of the faults and failures of elements of the shipboard power system is associated with reducing insulation electric resistance relative to the ship hull due to exposure to high humidity and temperature, and also mechanical damage of the insulating layer, electrical cables, wires, electrical machines and devices. The rules of technical operation establish the lowest values of insulation resistance of the elements of the ship's electric power system relative to the hull. At the same time, the presence of highly branched electrical networks on the ship complicates the task of centralized and localized control of insulation resistance. In addition, the increase in the number of power plants, possible change of the number of concurrent consumers in the power system, as well as increasing the share of high-voltage electrical equipment on the ship requires a more reliable control system of electrical insulation resistance. The author concludes that to ensure more reliable monitoring of insulation resistance of ship power system elements it seems relevant to use additionally new principles and methods for controlling the measurement information in the monitoring system and processing it, which differ from those traditionally used in the construction of such systems. For this purpose, as well as to improve the characteristics of the insulation resistance control system of the electric power system, it has been proposed to apply the Queuing theory with the assessment of its parameters. The presence on the vessel of a system of continuous automatic control of insulation resistance is an important component that ensures the reliability and safety of operation of the vessel by its crew.