The purpose of this work is to study the thermal stress of the furnace of a fire-tube boiler and its effect on the design of the boiler. To study the effect of thermal stress and furnace proportions on the ratio of heating surface areas, the calculated resistance was tested. Calculations of heat-tube boilers of sectional hot-water boilers with different proportions of the furnace at different thermal loads of the same furnace volume are performed. The calculation of each heating surface is carried out by the method of successive approximations, based in this case on the chord method. In the calculation process, the flue gas temperature at the outlet of the heating surface was first set, and then refined by successive approximations. To reduce the overall balance of the boiler, another global approximation is made when the temperature determined at the outlet of the last heating surface is set at the beginning of the calculation – in the heat balance, where it affects the loss with outgoing gases and the efficiency of the boiler. It is determined that the optimal.

Keywords: energy efficiency, fire-tube boiler, heat supply, thermal voltage, resource conservation

A comparative analysis of the lighting conditions of school premises was carried out based on design solutions for lighting devices from three Russian lamp manufacturers. All projects were carried out using lighting devices based on recommendations to manufacturers to use their range of lamps to illuminate various school premises. The design was carried out using the DIALux program. Each of the three manufacturers is widely known to specialists and has established itself as a reliable manufacturer of domestic lighting products, ready to offer a full range of lamps for various school premises. A technical and economic comparison of the total present costs for all lighting installations (using the example of one entire school) made it possible to conduct a comparative analysis and determine the most profitable options. An analysis of the current state of the Russian market of lighting devices recommended by manufacturers for classroom lighting has been carried out, their characteristics have been reviewed, and their compliance with current energy efficiency requirements has been assessed. Conclusions and forecasts have been made for the further development of lighting equipment with LEDs for lighting classrooms, based on the need to constantly improve the modern range of lighting devices in terms of their energy efficiency and competitiveness.

Keywords: technical and economic comparison, levelized cost method, comparative analysis, school lighting, lighting device, lighting modeling, energy efficiency

In this article, the authors consider the main aspects of maintaining the temperature and relative humidity of the premises of library collections and archive repositories using specialized engineering equipment. The preservation and preservation of material assets is designated as one of the priority tasks of preserving the cultural heritage of Russia. Conservation includes all types of activities and engineering support to guarantee the physical safety of any objects intended for long-term storage, such as library and museum. Currently, both the national program for the preservation of cultural values and the strategy for the development of librarianship have been adopted, including engineering methods for maintaining microclimate parameters for storage facilities and archives of various types: library, museum and federal purposes. Previously, the authors studied the reports provided on the preservation of library collections in Russia and abroad. It has been revealed that in a significant number of cases, the conditions for the preservation of both paper and other funds intended for storage and use as necessary to work with them are not provided. The authors conducted a study and analyzed changes in microclimate parameters when using central air conditioners of various configurations serving two separate sections of one library storage, which is a single-tier room type. The disadvantages of using a simplified basic modification of the central air conditioner based on the results of temperature and relative humidity control in each of the rooms, performed daily from January to June 2022, were confirmed. Variants of changing the configuration of engineering equipment with insufficient functionality with a limited area of the ventilation chamber are proposed.

Keywords: library, engineering equipment, central air conditioning, preservation of funds, conservation, microclimate, storage

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

Modern designs of water heating systems are saturated with different types of regulators, but their use is more often justified not by a systematic approach, but by solutions necessary for the operation of the system in its individual parts. The objectives of the presented work are to obtain and systematize experimental data to study the variable hydraulic mode of operation of horizontal water heating systems using apartment stations. In this paper, a problem in the field of development of modern water heating systems that needs to be solved is formulated. The analysis of the schematic solution of the heating system, as well as possible design options, was carried out. A simulation of the multivariate hydraulic mode of operation of the heating system of an apartment building was carried out on the simulator stand. The results of an experimental study are presented, and based on changes in design costs and the value of the adjustable pressure drop in parts of the system, proposals are made to reduce the cost of water heating systems for buildings under construction, as well as suggesting an increase in the ease of setup and quality of system regulation.

Keywords: balancing fittings, hydraulic characteristics research, water heating system, automatic regulators

The production of ultra high molecular weight polyethylene (UHMWPE) is associated with significant dust emissions into the production room, so the aspiration system plays an important role in the technological process. The study of dust in industrial product waste released into the work area is one of the objectives of the ongoing research. This work provides information on the dispersed composition of ultra-high molecular weight polyethylene (UHMWPE) particles, and various graphs are constructed based on the data obtained. Data on the deposition rate of UHMWPE particles were obtained experimentally. A comparative analysis of the obtained data with theoretical data obtained using formulas was carried out.

Keywords: ultra high molecular weight polyethylene, UHMWPE, dispersed composition of ultra high molecular weight polyethylene, sedimentation rate of ultra high molecular weight polyethylene particles, method for studying the properties of raw high molecular weight

The article considers the problem of sediment formation, sludge and corrosion on the heat transfer surface during the operation of heat exchange equipment at housing and communal services facilities. A new method of non-selective mechanical cleaning using a water hammer is proposed. The description and principle of operation of this cleaning system at the central heating station of the Ogarev Moscow State University are given. To confirm the effectiveness of the proposed technical solution, the results of thermal and hydraulic tests are presented.

Keywords: deposits, sludge, corrosion, cleaning, heat exchanger, water hammer, heat transfer

The article gives an insight into the traditional passive cooling techniques utilized in Mediterranean and hot climate regions, showcasing the effectiveness of natural ventilation and central patios in improving indoor thermal comfort and reducing energy consumption. The integration of these traditional design elements with modern technologies is crucial for creating environmentally friendly and culturally significant architectural solutions for the future. The discussion then transitions to the importance of energy efficiency and environmental sustainability in modern building design, highlighting the use of Ansys Fluent software for modeling natural ventilation in a residential apartment in Yemen. The article emphasizes the need for engineering and architectural solutions to achieve high performance in energy efficiency and environmental safety in contemporary construction practices.

Keywords: natural ventilation, Yemeni houses, Spalart-Allmaras model, civil engineering, Ansys Fluent

The paper describes the process of modeling 3D structures of synthetic gas burners, with the analysis of the simulation results obtained for several types of models and the selection of optimal modes for them. The main use of the burner is planned for boiler equipment for household needs in private as well as apartment buildings, in the absence of central heating. In addition, the article provides a justification for the thermal parameters at the inlet and outlet of the burner.

Keywords: synthesis gas, combustion, design parameters, combustion chamber, nozzle, modeling

Using numerical simulation, particle deposition in a porous heat exchanger was studied; the mechanism of sediment formation was sinvestigated, and the influence of sediment on the heat flow was assessed. The influence of porous heat exchanger length, dust particle size, and air flow velocity on particle deposition efficiency, particle breakthrough, and heat flux value was studied. Research results have shown that with increasing length of the heat exchanger, the efficiency of dust particle deposition increases, which leads to the formation of sediment. In turn, the sediment reduces the value of the heat flow from the porous heat exchanger. Depending on the length of the heat exchanger and air velocity, the reduction in heat flow is 3.43-7.27%.

Keywords: porous media, heat exchanger, particle deposition, deposition efficiency, particle breakthrough, sediment, heat flow, numerical modeling, computational fluid dynamics, calculation

The use of closed methods for laying underground polyethylene gas pipelines using horizontal directional and directional drilling methods when crossing artificial and natural obstacles is considered. The results of calculating the geometric parameters of the working and receiving pits when laying polyethylene gas pipelines using a closed method using horizontal directional drilling are presented.

Keywords: polyethylene gas pipeline, closed installation method, horizontal directional drilling, directional drilling, dimensions of working and receiving pits

The article is devoted to modeling heating of fuel oil using a pulsed fluid flow in the SolidWorks Flow Simulation software module. In the future, the use of this technological solution can be considered by a number of industries in the Russian Federation and abroad. The purpose of this article is to describe the results of a computer model of the technological process under study. The computer calculation of the fuel oil heating model using a pulse flow makes it possible to evaluate the efficiency of the process and determine the optimal parameters to achieve maximum efficiency. This will help to reduce the cost of heating fuel oil and increase the efficiency of industrial equipment of enterprises.

Keywords: fuel oil, oil, coolant, shock unit, diaphragm pump, pulse flow, turbulent mode, cavitation, solidworks flow simulation

When choosing an intensification method, the assessment of thermal-hydraulic efficiency is an important criterion. In this paper, the thermal-hydraulic efficiency of the pulsating method of heat transfer intensification was assessed as applied to an in-line tube bundle. The thermohydraulic efficiency was estimated by comparing the ratio of the increase in the Nusselt number to the increase in the coefficient of friction factor in a pulsating flow compared to a stationary flow. The coefficient of friction factor was determined by numerical simulation in AnsysFluent. The results of a numerical study showed that an increase in the product of the pulsation amplitude and the Strouhal number leads to a decrease in the thermal-hydraulic efficiency at all values of the Reynolds number, while the thermal-hydraulic efficiency is higher at the minimum values of the Reynolds number.

Keywords: Reynolds analogy factor, flow pulsation, heat transfer enhancement, thermal hydraulic efficiency.

In connection with improvement of public welfare, coming to the fore are requirements enabling comfortable living, which primarily depends on conditions of indoor air environment. This article provides arguments to suggest that, during reconstruction and overhaul of residential buildings, natural ventilation systems, failing to provide the required air exchange, need to be replaced with hybrid ventilation systems, allowing to maintain stable ventilation in existing multi-storey buildings throughout the year and involving minor capital and operating costs. Based on the example of a typical nine-storey residential building, two variations of hybrid ventilation have been developed: containing an ejector and roof fans, with economic feasibility of using both determined.

Keywords: microclimate quality, air exchange, natural ventilation, hybrid ventilation, an ejector, a roof fan, economic feasibility

The possibility and expediency of switching from qualitative regulation of heat supply to quantitative in centralized heat supply systems for the existing network from the district boiler house No. 1364 of Volgograd is substantiated. The main advantages and disadvantages of each method of regulating heat supply to consumers are considered. The basic formulas for determining the thermal loads required depending on the outside air temperature, the hydraulic calibration calculation of the existing network from boiler house No. 1364 are described. Volgograd, determination of the internal hydraulic characteristics of the resistance of the heat network and determination of the required hydraulic regime for consumers of the microdistrict No. 1364, depending on the change in coolant flow due to the regulation of the speed of rotation of the pump impeller. As a result, the implementation of the transition from a qualitative to a quantitative method of regulating heat release is possible without serious hydraulic interventions.

Keywords: heat supply, control methods, heat carrier temperature, heat carrier consumption, boiler room, heat network, pump, frequency-controlled drive, hydraulic modes, thermal energy saving

The results of research of engineering solutions for ventilation of swimming pools based on mathematical modeling taking into account real thermal loads and moisture releases are presented. The analysis of air distribution options in rooms with swimming pools for various purposes – a public swimming pool, a SPA complex and a sports pool with bleachers for spectators. Based on the results obtained in the form of distribution fields of the parameters of the air environment, the necessary changes in the schemes of the organization of air exchange are revealed. If the parameters deviate from the normalized values, recommendations have been developed to improve the state of the microclimate. These temperature distributions allow us to conclude that the air temperature near the surfaces of external fences meets the requirements that ensure their safety. conclusions on the compliance of the obtained results with the required parameters of the microclimate for rooms with high relative humidity.

Keywords: Swimming pool, ventilation, heat, moisture, air distribution, microclimate, air environment, numerical modeling

The article discusses the main causes of natural gas leaks and ways to detect them. Data on the volume of natural gas leakage and the nature of damage were obtained at the experimental installation. The objects of experimental research are gas connections to devices, such as: bellows hose made of stainless steel, rubber hose and cap nut of gas connection with varying degrees of tightening. The course of conducting an experimental study of filling a room with natural gas, depending on the degree of damage to the gas supply and its nature, is described. The analysis of the results of the experiment to determine the dependence of the gas flow rate on the type of damage to the gas supply is carried out. The most dangerous types of leaks in the room are determined, graphs of the dependence of gas flow through various damages and methods of their prevention to prevent such situations are constructed.

Keywords: gas leak, gas appliances, leak detection, types of gas leaks, type of damage to the gas supply

The value of the efficiency of domestic gas boilers of the brand Baxi ECO-4S 24 with various schemes of air supply and smoke removal is considered. The difference in the calculated efficiency values and the passport values is analyzed.

Keywords: efficiency, flue gas discharge, household gas boiler, thermal balance, energy efficiency

The tasks of preparing for the modernization of the automatic pressure control system with the transition from the use of a PD controller in favor of a PID controller and the introduction of a controlled electric fan drive in a boiler plant are being solved. A technique for constructing a fan model in the automatic control system for air supply to the boiler is given using the example of a VD-18 blower fan and a BKZ-160 boiler. The block diagram of the operation of the fan and pipeline is given. A mathematical model of the fan is shown, a calculation is made and a computer model is designed in MATLAB Simulink. The simulation results are presented, which prove the correctness of the obtained model. The presented model can serve as a basis for automating the air supply system in other boilers using blowers.

Keywords: automatic pressure control system, automatic control system, dynamic model, computer model, blower fan, boiler plant

The article substantiates the need to clarify the value of pressure losses in the shut-off valves. Various methods of determining the coefficient of local resistance of steel ball valves are considered. A comparative analysis of the values of the local resistance coefficient obtained theoretically and experimentally is performed. Recommendations on the application of numerical values of the local resistance coefficient of steel ball valves are given.

Keywords: hydraulic calculation, pressure loss, disconnecting devices, ball valve, local resistance coefficient

The work of new Russian regulators RED is being considered. The results of a study of the compliance of regulators with the declared class of locking pressure using the "PLEXOR" installation are presented. The conducted tests show that Russian gas pressure regulators in the conditions of import substitution are not inferior to foreign analogues in their technical and functional characteristics.

Keywords: gas reduction point, pressure regulator, locking pressure class, diagnostics, setting limits

The issues of seasonal unevenness of gas consumption for the needs of heating, ventilation and hot water supply of the shopping and leisure complex are considered. Calculations of volumetric and power indicators of uneven gas consumption for 2020-2022 are given according to the data of the archive of gas consumption meters.

Keywords: gas consumption, uneven gas consumption, volume, capacity indicators, shopping center

The work of the FL200AN300+TR regulators installed in the hydraulic fracturing plant No. 4 in Volgograd is considered. The results of calculations of the throughput capacity of pressure regulators are presented. The range of their stable operation is determined on the basis of archival data of the gas flow metering unit. It was revealed that not all outlets provide stable operation of pressure regulators with minimal gas consumption.

Keywords: head gas control point, pressure regulator, throughput, range of stable operation