In the presented scientific work, the basic design versions of the thrust bearings of Hydrogenerators are considered. The main causes of emergencies in the thrust bearing unit of a high-power Hydrogenerator are considered. The main requirements for the operation of thrust bearings are submitted. Cause-and-effect relationships of emerging and development of defects are established. Existing methods for calculating the stressed state of a thrust bearing in the classical formulation for a stationary mode of operation are considered. The main features of the operation of the thrust bearing unit are investigated in relation to the features of the sliding bearings. The calculation of the elastic chambers of the hydraulic thrust bearing in a three-dimensional formulation is carried out, taking into account the physical properties of the oil, the material of the chambers and distribution of the acting loads. It is shown that the applied designs of Join Stock Company “Ukrainian Energy Machines” can be used in high-power Hydrogenerators.

In this article, the main causes of vibration in the thrust bearing of hydrogenerator motors rated 320 MW are considered. The main types of internal and surface defects that appear on the working surface of the thrust bearing disc during long-term operation are considered. A method of three-dimensional modeling of such defects is presented, and an assessment of the stress-strain state of the heel disc is proposed, taking into account the main forces acting on the working surface using the finite element method. An analysis of the possible further operation of discs with similar defects, in accordance with the technical requirements, is carried out, and we consider ways to eliminate them.

In the submitted scientific work, the existing types of stator fastening design of turbogenerators and the main causes of the stressed state of the stator suspensions are considered. A detailed calculation of the complex stressed state of the turbogenerator stator suspension was carried out for a number of electrical sheet steels, taking into consideration the unevenness of the heat distribution along the horizontal axis of the unit. It is proposed that the calculation of the mechanical stress is carried out by means of the mechanical and thermal calculation, coordinated with the electrical one. The possibility of replacing steel 38Х2Н2ВА with steel 34CrNiMo6 and 40NiCrMo7 is indicated, subject to compliance with GOST 8479-70 for the same strength group.

This study's object is the aerodynamic characteristics of the compressor diffusers in hydrogen-cooled turbogenerators. This paper reports a solution to the task of improving the efficiency of a cooling system discharge unit. This issue relates to enabling the necessary gas consumption while reducing the number of diffuser blades. The problem was solved by introducing a seal with improved technological control capabilities and step-by-step optimization of the diffuser flow part. Another issue is the thermal loads on the power components of the diffuser unit due to the action of circulating currents and temperature gradients. The problem was solved by introducing dielectric and non-magnetic elements into the structure, by additional finning and multi-component design for the diffuser strength circuits. The main result is the designed multi-component diffuser structure with a number of blades of 20 while enabling a head of Hst = 978 mm H2O. The adopted duct opening angle was 20°. Other necessary geometric parameters were determined. The introduction of a multilayer seal made it possible to reduce the gap between the impeller and the diffuser to 0.9 mm. The proposed design was tested on the bench at a manufacturing enterprise. The results of the study are attributed to the use of non-magnetic and dielectric materials (AISI 321 steel and fiberglass), as well as the introduction of additional strength decoupling elements. A special feature of the proposed method is the application of mathematical models based on the basic equations of gas dynamics, taking into account the composition principles of engineering alloys and synthetic materials. This could be achieved via a step-by-step optimization of the design. The proposed structure could be implemented when designing and modernizing hydrogen-cooled turbogenerators

Gas coolers are critical elements of turbogenerator cooling systems, which ensure the reliability and stability of the thermal mode of high-power electric machines. The aim of this research is to improve the accuracy of thermal calculations of gas coolers by combining analytical methods with numerical CFD-modeling (Computation Fluid Dynamics). The cooler’s total cooling capacity is approximately 3.8 MW, distributed across three identical sections.An analytical calculation of heat transfer for a hydrogen-water gas cooler with finned tubes was performed, using classical dependencies to determine the heat transfer coefficients and pressure losses. The results were verified using three-dimensional CFD-modeling of the hydrogen flow through the cooler using the standard k-ε (k-epsilon) turbulence model. The discrepancy between the results of analytical and numerical calculations is less than 10%. The temperature of the cooled hydrogen at the outlet meets the design requirements (+40 °C); however, areas of uneven temperature distribution were identified that require further design optimization. The study introduces, for the first time, a combined approach using analytical calculations and CFD by thoroughly evaluating the heat exchange between the cooling tube fins and hydrogen. This scientific solution enabled the simulation of hydrogen flow within the multi-stage cooler system. The proposed method has proven to be reliable and can be applied both at the design stage and for the analysis of upgraded cooling systems of turbogenerators.