The water-chemical condition of the steam generators (SG) within the established limits are supporting by a purge. The purge is two kinds they are permanent and periodic. The main idea of the purge consists in taking part of the boiler water from the places of the most likely accumulation of sludge, corrosion products, salts, as well as water purification and its subsequent return to the circuit. The further way of boiler water which is taken from SG is the purge expander. The thermal-hydraulic sketch which is shown in the article and considered to be a mathematic model of the purge expander illustrated level changes in dynamic. Also the mathematic model of automatic control system for purge expander level control which includes a fuzzy governor is presented in the article. Both models are realized with use of software for technique system modelling called SimInTech. The technique implementation of level governor in the SG purge expander realized on the base of the standard software and hardware TPTS-EM which is used as grassroots automation for automatic control system in the technological process of NPP having water-water power reactor which power is 1000 megawatt.

Keywords: reactor, purge, steam generator, corrosion, erosion abrasion, heat carrier, purge expander, governor, model, fuzzy logic, level, pressure, consumption

This article analyzes the problem of determining the location of an object based on the method of passive positioning of single-station systems with a long baseline. The method proposed in the article implies that the antenna array is integrated into a single-station system with a long baseline using three antennas. The mentioned method is able to determine the actual location of the radiation object and the parameters of the object's position by estimating the phase difference and the actual direction of the radiation object. The simulation results confirm the validity of the proposed method.

Keywords: antenna array, passive positioning system, phase difference, bearing, azimuth, error

The paper proposes a model of a circuit with a pulsating circulation of a liquid coolant for cooling an oil transformer and investigates the dependence of the heat transfer coefficient on the frequency of the liquid pulsation in the heated circuit. As a result of the experiments, it was found that the pressure amplitude remains practically unchanged up to a frequency of 0.45 Hz, then sharply decreases and at a frequency of 0.9 Hz it is approximately 12.5 kPa. It was also found that in the heated circuit (circuit 1) the temperature difference exceeds the temperature difference in the heating circuit (circuit 2), which is due to the fact that the fluid flow rate in the heating circuit exceeds the flow rate in the heated circuit. The theoretical calculation carried out showed that in the proposed model the heat transfer coefficient reaches its maximum at a pulsation frequency of 0.6 Hz and is 133.675 W/m2K.

Keywords: energy efficiency, oil transformer, heat recovery, heat exchanger, transformer cooling

The article considers the potential of atmospheric pollution by a combination of certain average annual values of microclimatic parameters and the range of their changes. Numerical methods for solving the turbulent diffusion equation are used in the construction of research models of various scales. An important place among them is occupied by methods of component-by-component splitting. With their help, it is possible to solve not only direct, but also inverse (conjugate) problems. The presented program allows calculating one-time concentrations of impurities under various meteorological conditions based on data on sources of impurity emissions and local conditions and provides for the possibility of constructing a topo-base of the settlement platform.

Keywords: microclimatic parameters, pollution, surface concentrations, topo bases of the settlement platform, methods of component-by-component splitting

The paper considers theoretical studies of the deformed state of the nagel joint with claw washers in LVL structures (from the English LVL – Laminated Veneer Lumber). A mathematical model of snow load has been developed. The method of theoretical calculations of creep from the action of periodic load on the basis of previously performed experiments is given.

Keywords: claw washer, LVL, connection, deformation, mathematical model, load, regression equation, humidity, creep

The regulation of the stress-strain state of the floor slab is considered in order to choose the optimal design solution for the frame of a unique building. Three variants of design solutions with varying reinforcement of the plate and cross sections of the vertical elements of the frame are proposed. The numerical experiment was performed by the finite element method using the Lira-CAD software package. To improve the accuracy of the results obtained, calculations were made taking into account the nonlinear operation of materials. The computational model of the floor slab includes physically nonlinear shell finite elements. Nonlinear loading was modeled taking into account the creep of concrete. Based on the results of the calculations, the analysis of the deflections of the floor slab and the consumption of materials was performed. The numerical experiment allowed us to propose an optimal design solution for the frame of a unique building.

Keywords: stress-strain state, finite element method, unique building, physical nonlinearity, deformation law, building frame

This article proposes a way to automate work on the development of the construction schedule (CP) based on BIM-model. As an example we used the project of an oil well pad developed by VolgaTEKengineering LLC in Khanty-Mansi Autonomous Okrug in 2019.

Keywords: construction, building information modeling, BIM, 3D, 4D, 5D, schedule, estimate

The topic of BIM is relevant for the present and is inseparable from the issues of infrastructure development and Smart Cities development projects. Our country is on the path of digital transformation and the development of information technologies in all its fields of activity. BIM technologies are being introduced into the construction industry and will be developed through the promotion of the state. BIM technologies create information models that are implemented through infrastructure projects. This process creates the basis for smart cities. Within the framework of the work, the directions of development in "Smart cities" were highlighted, the positive effects of BIM technologies were considered.

Keywords: smart city, BIM technologies, information model

The method of numerical calculation of the parameters of the river channel in the arms is given. The method of nonlinear programming for analysis of dissipative systems with concentrated parameters is used. The technique is focused on computer modeling in the environment of engineering package MathCad. The results of the experiment are given.

Keywords: Distribution of water flow, calculation method, multi-node sections of rivers, water flow