This paper highlights the problem of determining the durability of water heating systems based on a comprehensive analysis of oxygen permeability and corrosion processes. The focus is on electrochemical corrosion of the steel elements of the system. Such types of corrosion as general, local, pitting and ulcerous are considered. Various experimental data were analyzed and quantitative dependences of corrosion rate, corrosion permeability and depth of ulcer corrosion depending on coolant temperature and dissolved oxygen concentration were obtained from them. For water heating systems with polymer pipes without an oxygen barrier, a methodology for calculating the dynamics of oxygen concentration in the coolant has been proposed. A criterion for assessing the durability of the system has been developed, which connects the accumulated depth of peptic ulcer corrosion with the wall thickness of the most thin-walled element. It has been shown that the durability of the system directly depends on the initial oxygen content and oxygen permeability of polymer pipes. The proposed method makes it possible to predict durability and plan equipment replacement, preventing accidents.

Keywords: corrosion, pitting corrosion, heating systems, polymer pipes, heat carrier, oxygen permeability, durability

The article is devoted to the development and calculation of cable-stayed structures used as protective barriers against unmanned aerial vehicles (UAVs). The analysis of the design and calculation of cable-stayed structures for protective enclosing structures designed to counter UAVs is carried out. The main stages of the calculation are considered, including the determination of external loads, dynamic modeling of shock effects, finding the dynamicity coefficient through energy loss, and the conversion of kinetic energy into potential energy. The prospects for the development of this area are discussed with an emphasis on modularity, adaptability and integration of systems. It is concluded that cable-stayed structures are a promising solution for protecting critical facilities, providing high strength with minimal weight and cost.

Keywords: cable-stayed structures, impact impacts, protective enclosing

The schematic solution of the heating system is analyzed, as well as possible variants of design solutions. A multi-variant hydraulic mode of operation of the heating system of an apartment building is simulated on a simulator stand. The results of the experimental study are presented, and based on the change in design costs and the value of the adjustable pressure drop in parts of the system, proposals are made that allow reducing the cost of water heating systems of buildings under construction, as well as suggesting an increase in the simplicity of adjustment and quality of system regulation.

Keywords: water heating system, oxygen permeability, gas permeability, polymer pipes, gas solubility