Operational Characteristics of 10–12% CrMoV Bolt Steels for Steam Turbines

Author(s):  
K. H. Mayer ◽  
H. König
Author(s):  
A. Yu. Sosnovskiy ◽  
B. E. Murmanskiy ◽  
Yu. M. Brodov

ТНЕ PURPOSE. To carry out a comparative analysis of the performance characteristics of the longitudinal movement guides of the external bearing housings of steam turbines, using the principle of rotation to ensure full contact of their lateral surfaces with the lateral surfaces of the guide groove at the base of the external bearing housing of the steam turbine. Compare the manufacturability of elements and their implementation for both existing and newly developed steam turbines .METHODS. The permissible transverse forces are determined from the strength conditions and compared for the traditional design of fixed longitudinal guides and the design of guides, in which the principle of rotation is used to avoid "biting" of the bearing housing on the guides when temperature misalignment appears along the flanges of the turbine cylinder. Also, the allowable forces are determined and compared from the condition of the absence of plastic deformations in any of the elements of the interface of the guides, the base frame and the bearing housing. Based on the results obtained, the value of the permissible temperature misalignment along the flanges of the turbine cylinder is estimated. The analysis was carried out in relation to the operating conditions of the front bearing housing and HPC of turbines of the T 100/120-130 UTZ family.RESULTS. It has been established that all the considered designs of guides with pivoting elements make it possible to exclude the occurrence of plastic deformations in the junction of the base frame and the outboard bearing housing at a temperature misalignment of 20°C regulated in most turbine operating instructions. CONCLUSION. The design of longitudinal keys proposed by UTZ does not require a change in the technology for manufacturing the foundation frames and allows the unit to be modernized during repairs in a CHP. The best performance disc guide design can be used in new turbine designs or factory retrofits.


2019 ◽  
pp. 82-87
Author(s):  
Nina P. Nestyorkina ◽  
Olga Yu. Kovalenko ◽  
Yulia A. Zhuravlyova

The article analyses the operational characteristics of 10W LED lamps with T8 bulb manufactured by ASD (Russia), Smartbuy (Taiwan), and VOLPE (PRC) and 18W FL with T8 bulb manufactured by PHILIPS (Poland) including the dependence of these lamps on the supply voltage. The results of measurements show that: a) the period of stabilisation of electric parameters and luminous flux of LED lamps does not cause discomfort of illumination unlike the said FL, the luminous flux of which at the moment of switching on is 70 % of the nominal value, which is reached after 13 minutes; b) with nominal voltage of supply network, the value of luminous flux of 10W ASD LED-T8R-STD LED lamp (Russia) is 6 % less than the declared one, and that of Smartbuy SBL-T8-10-64K-A (Taiwan) and VOLPE LED-T8-10W/DW/G13/FR/FIX/N (PRC) is even less; c) the general colour rendering index of all studied LED lamps is less than the declared one (72 instead of 80); d) the flicker index of all studied LED lamps does not exceed the declared value of 5 %; e) the characteristics of LED lamps almost do not depend on changes of the supply voltage within the range of ±10 %. The recommendations regarding the application of the studied LED lamps are given.


2020 ◽  
pp. 39-48
Author(s):  
B. O. Bolshakov ◽  
◽  
R. F. Galiakbarov ◽  
A. M. Smyslov ◽  
◽  
...  

The results of the research of structure and properties of a composite compact from 13 Cr – 2 Мо and BN powders depending on the concentration of boron nitride are provided. It is shown that adding boron nitride in an amount of more than 2% by weight of the charge mixture leads to the formation of extended grain boundary porosity and finely dispersed BN layers in the structure, which provides a high level of wearing properties of the material. The effect of boron nitride concentration on physical and mechanical properties is determined. It was found that the introduction of a small amount of BN (up to 2 % by weight) into the compacts leads to an increase in plasticity, bending strength, and toughness by reducing the friction forces between the metal powder particles during pressing and a more complete grain boundary diffusion process during sintering. The formation of a regulated structure-phase composition of powder compacts of 13 Cr – 2 Mо – BN when the content of boron nitride changes in them allows us to provide the specified physical and mechanical properties in a wide range. The obtained results of studies of the physical and mechanical characteristics of the developed material allow us to reasonably choose the necessary composition of the powder compact for sealing structures of the flow part of steam turbines, depending on their operating conditions.


Author(s):  
A. E. Melnikov

Currently, one of the important tasks of the economic policy of Russia is the formation of a hightech image of the national economy, capable of effective functioning in the changing global geopolitical and geoeconomic conditions. In this context, the issue of revitalization of mechanical engineering, which plays a key role in the development of the country’s economy, is of particular relevance. This sector is a link between scientific and technological progress and the level of provision of domestic producers with domestic machines and equipment, allowing them to produce competitive products and to a lesser extent depend on the state of the external environment. The example of the developed countries of the world shows that the development of advanced engineering technology significantly increases the efficiency of the national economy, helps to accelerate its growth. At the same time, in Russia, in order to unleash the scientific and technical potential and activate engineering, it is necessary to initiate modernization processes in it. Based on the foregoing, the purpose of the study is to analyze the state of Russian engineering from the position of its role in the country’s economy. It is shown that at present a significant barrier to the development of this sector is the predominance of imported equipment, due to technical and operational characteristics, often superior to domestic counterparts.


Sign in / Sign up

Export Citation Format

Share Document