In the period of sharp warming conditions can occur in which the temperature of the outer surface for some time will be below the ambient air temperature. While warmer ambient air, not in contact with the heated surface of the wall may cause condensation on the surface. The article discusses some of the exterior building envelope, in conditions of rapid warming and condensation process of moisture on the outer surface of the walls. With the help of finite difference method numerical modeling of the thermal regime of the outer surface.
Keywords: Exterior walls, non-stationary conditions, moisture condensation, winter
The article discusses the influence of the distance between the axes of pipes laid on the efficiency of the temperature distribution in the floor heating system. Using the computational experiment was simulated the temperature field on the surface of the floor heating. The calculations are performed using the program ELCUT.
Keywords: underfloor heating, numerical simulation, temperature field, the temperature of the feed piping system radiant heating
The aim of this work is determination of regularities that determine the operation parameters of the fan in a thermally non-stationary ventilation system contains a heater located along the air flow after the fan. It is established that the ventilation system, containing the heater, has two characteristics aerodynamic resistance related to the volumetric air flow at the sections of the network before and after the heater. It is proved that when using the superposition method, P-L characteristics to determine the parameters of the fan in the system, you must apply the P-L characteristic of the network is related to the volumetric air flow to the heater. The obtained dependences determine the parameters of the fan depending on its aerodynamic characteristics and the location of the heater in the system.
Keywords: the ventilation system is in a thermally transient mode, fan, heater, energy efficiency, energy conservation
Discusses issues related to the definition of process reliability systems. The dependence to determine the amount of damage accumulation to failure in the presence and absence of the experimental data.
Keywords: aspiration system, process reliability, failure, wear, damage, legal distribution of a random variable, the value of damage accumulation
For the region South of Russia is characterized by abrupt changes of temperature in winter. In the normative literature focuses on how the stationary thermal regime. Not enough investigated how it will affect the thermal design of building envelopes of a sharp increase in outdoor temperature. The paper considers the dynamic change of the temperature distribution of the outer walling for the conditions of rapid warming during winter on the example of enclosing structures made of different materials.
Keywords: dynamic analysis, building walls,temperature distribution, winter conditions
The wide distribution systems radiant panel heating in floor heating in wet areas, allows to increase comfort. Part of the thermal energy will increase the rate of evaporation from wetted surfaces. The article describes mathematical model and algorithm of calculation of the temperature field of the surface subject to evaporation. In the paper numerical experiment to analyze the efficiency of the distribution system temperature floor heating in wet areas.
Keywords: The evaporation of moisture from the surface, phase transition, Underfloor heating, wet rooms, temperature field
With the aim of obtaining objective data about the energy potential of the air flow in the ventilation system proposed to use the parameter "local mechanical power flow". The formulas describing the change of this parameter in different parts of the ventilation system. Describes the author's method of graphic representation of the processes of change of flow parameters in the coordinate axes L - Pn, allowing enough just to determine the change in local mechanical power on isothermal and non-isothermal sections of the ventilation system.
Keywords: ventilation system, fan, mechanical power, heat exchanger, energy efficiency, energy conservation
Discusses current issues related to the definition of the efficiency of ventilation systems on the composite elements of the installation. The dependence for determining the efficiency of the installation taking into account pressure losses in the elements of the installation.
Keywords: ventilation, air supply unit, efficiency, electric motor, quality criteria, pressure loss, power
In the article discusses the features of work air handling unit (AHU) based on spray chamber (SC), developed the design of the test bench and presents the results of the tests SC, identify ways to improve them, particularly in the lower part of the workspace was placed plane-parallel packing. It was established experimentally that the efficiency of processes of heat and moisture transfer increased by an average of 6 - 10%.
Keywords: air handling unit, spray chamber , heat and mass transfer, efficiency
The hydraulic test of perfect dead-end gas network with gas supply source and one consumer is performed by two ways: 1) natural experiment 2) the modelling of system in the specific programmatic sphere. Comparative analysis of natural experiment with the software simulation is performed. The effect of decrease gas load of consumers on optimally pressure of gas supply source is studied. The impact of the selective method of the calculation on the optimal huidraulic mode choice of the network function is analysed. The grafic relations are formed. The coefficient of optimum pressure is calculated and that makes it possible to determine the most adequate pressure of gas as it leaves the gas supply source on the basis of the pressure requirements in gas-based units.
Keywords: Gas supplying, the reliability of gas distribution system, natural experiment, the software simulation
The results of analysis of regulatory requirements for dust collection systems based on existing environmental legislation. Development of systems for dust collection and dust extractor is using the tools of quality management. It has established a set of basic technical requirements for systems of dust removal and their parts taking into account modern requirements for energy efficiency.
Keywords: ecology, environmental regulations, dust collection, air quality management, dust collectors, energy efficiency
The results of the analysis of the energy efficiency of water heating's accession to the heat network. Introduced the concept of the coefficient of the hydropower efficiency. Discusses the features of its calculation in the dependent scheme of attaching the water heating system of consumers to the heat network and the independent circuit.
Keywords: Heat supply network, individual heating unit, water heating system, energy efficiency, hydropower efficiency ratio
The article is devoted to the improvement of heat exchangers for use of secondary heat potential gas-flow aspiration schemes in the construction industry. The use of waste heat from the thermal processing equipment raw materials and products can save the amount of fuel burned in the whole cycle of thermal power enterprises. It was researched and proposed improving of design and development of new heat-saving device for the effective use of secondary heat energy resources of hot gases’ emission of aspiration schemes at building industry. There is presented some results of a study of the heat transfer parameters in the proposed design device with fluidized bed of granular material as a the form of nozzle in this article. It was obtained and observed the regression relations for a few fluidized bed of granular material in the form of pellets, granules in the general kind of one’s. The design of the fluidized bed heat exchanger for efficient use (recycling) secondary heat and mass exchanging devices and determine the heat transfer coefficients in the range of effective modes of operation for use in aspiration schemes at building enterprises. There is presented the result of the executed experimental research and modeling in the form of generalized regression dependence for the the Nusselt criterion relations to determine the heat transfer coefficient from the particles to the solid tube’ wall where water is circulated inside within the fluidized bed granules in this article. It’s and to be heated in proposed. Efficient use of resources through the secondary heat from waste is also one of the most effective ways to implement measures to reduce thermal pollution and improve the environmental safety of the construction industry as a whole. Modernization of technologies and devices, providing a more efficient use of heat and energy resources and heat pollution of environment simultaneously, is an important task of innovative development and transformation of the industry construction and country. It was mentioned the some recommendations for proposed device’ use in the construction industry.
Keywords: granule, a heat exchanger, fluidized bed, building material, speed, pollution, environment, scheme, aspiration, recovery and heat savings
The article is devoted to the problem of modeling heat exchangers with fluidized packing of disperse material whenшы used in aspiration schemes at construction industry enterprises. Innovative transformation of industry and construction industry is associated with the most complete and effective use of thermal, energy potentials including low-potential secondary resources. The use of waste gas heat from equipment during thermal processing of raw materials and products, and ejecting in aspiration schemes, allows to reduce the specific consumption of fuel burned per unit of output production by the construction industry enterprises. There is presented an approach to modeling and calculation of heat transfer in the apparatus of the proposed design with a nozzle in the form of a fluidized bed of granules of a dispersed material in this article. There is presented the result of the executed experimental research and modeling in the form of generalized regression dependence for the the Nusselt criteria relations to determine the heat transfer coefficient from the particles to the solid tube’ wall where water is circulated inside within the fluidized bed granules in this article. It was described generalized form of the regression relation for the calculation of heat transfer in a heat exchanger with a fluidized bed of packing dispersed materials in the form of granules in this article.
Keywords: modeling, heat exchanger, fluidization, bed, material, velocity, criteria, pollution, atmosphere, scheme, aspiration
One of the most important systems for ensuring the required air quality in Orthodox churches is the ventilation system. Mechanical ventilation is getting contaminated during operation. The air, passing through the air ducts, contains dust particles, including pathogenic bacteria. To prevent bacteria from multiplying in the ventilation system, bactericidal filters must be used. Halls of Orthodox churches belong to public buildings with a large crowd of people with a long stay. Such premises require a bactericidal efficiency of at least 90%. For the ventilation systems of the church of St. Theophan the Recluse, the authors proposed and implemented a device for bactericidal air treatment using ultraviolet radiation. The bactericidal effectiveness of this device was 92%, which is higher than required. The authors recommend using the proposed device for public buildings.
Keywords: Orthodox church, church buildings, ventilation of religious buildings, bactericidal treatment of air, ultraviolet radiation, air disinfection, bactericidal effectiveness
The article is devoted to the peculiarities of qualitative and quantitative composition of emissions in the production of building materials. This article describes a way of reducing dust emissions of solid substances pollutions exhausted in the atmosphere in the manufacture construction materials. The article focuses on the environmental problems of building construction industry. Volume of production of building materials is growing up and amount of dust particles substances in emissions around 5-8% every year at least both. One of ways to increase the environmental safety is reduction of dust emissions. Data on the relative content of some types of dust, typical for the construction industry in the total dust emissions entering the atmosphere of the city enterprises. The results of studies show that a significant content of fine particles, for example, 10 microns or less is concern in dust emissions systems of aspiration at the building construction enterprises. The great amount mention above of solid substances fine particles dimension involves the usage of special complex integrated analysis method of variance dust. The great amount mention above of solid substances fine particles dimension involves the usage of special complex integrated analysis method of variance dust. The value of the maximum permissible concentration of fine particles content by mention above dimension (around 10 microns) is less than for ordinary powder of building materials’ dusts. There exist and work a lot of building materials enterprises treat with bulk building materials in present time. It isn’t necessary to have ecological project of limitation emissions for small construction companies. So that this reason demands the improvement norms methodology for limitation for fine particles are concern in dust emissions systems of aspiration at the building construction industry. It allows preventing growing pollutions of atmosphere by emissions with fine particles dust.
Keywords: Dust, cement, sand, emissions, environment, system, building industry, analysis of variance, rationing, aspiration
This article describes a way of reducing dust emissions of solid substances pollutions exhausted in the atmosphere in the manufacture construction materials. The article focuses on the construction industry to improve the environmental safety improvement dust decreasing systems using complex integrated analysis method of variance dust emissions of dust aspiration systems. The article suggested developing a promising approach to improving the methods of complex analysis of variance with dust particles medium average rate (weighted average) parameters and integrated particle distribution function hydraulically equivalent size’ dimension and sedimentation’ time of dust samples investigated sample. Studies show that the use of response hydraulically equivalent size and the velocity of dust particles hovering sedimentation’ functions allow to obtain more reliable results of complex integrated analysis method of variance of the dispersion dust. At the same time developed using the results of such research and the complex devices used in combination of dry and wet cleaning can significantly reduce the amount of loose dust emissions in the production of building materials. The research’s results show that the integrated use of the devices dry and wet cleaning can significantly reduce the amount of loose dust emissions in the production of building materials. Reducing emissions of dust is one of the most effective reliable ways to implement environmental protection measures and to Increase of ecological safety of building materials industry treat with dispersion-bulk materials.
Keywords: dust, cement, sand, dust collector, cleaning, construction materials, leakage, analysis of variance, velocity, sedimentation, the atmosphere, the scheme, dust removal, aspiration
The article discusses the influence of design parameter of the spin flow of primary input on efficiency of dust collection and aerodynamic resistance of dust collector on the counter swirling flows. Covers theoretical and experimental dependences describing the effect of setting the initial twist of the flow on the collection efficiency and the aerodynamic resistance of dust collectors, and the optimal values of the initial intensity of the spin flow
Keywords: dust collector, inertia precipitator and counter-swirling flows, the separation chamber, the aerodynamics of the near-wall region, the motion parameters of the dust particles, the primary input stream, formparametr swirling flow, the dust collection effic
The paper analyzed the influence of the shape and projection of its location on the surface of the heat sink on the heat source temperature. Based on the theoretical analysis, it was shown that the pins, ribs, hinges, and other projections are present on the surface of the heat sink, it does not increase the cooling surface and heat-loaded lower temperature source. These designs provide only near the side surfaces of the rapidly decreasing dipole, quadrupole, and other components of the field, which are not conducive to heat dissipation from the source, and create a circulating flow.
Keywords: radiator protrusion shape, thermal conductivity, thermal apparatus mode, the temperature of the heat source
The main maintenance of a diversification of production as activity of subjects of managing is considered. being shown in purchase of the operating enterprises, the organizations of the new enterprises, redistribution of investments in interests of the organization and development of new production on available floor spaces. The most important organizational economic targets of a diversification of management are presented by innovative activity of the industrial enterprise.
Keywords: heat transfer, coefficient of heat transfer, thermal conductivity, similarity criteria, electric analog, vertical pipe, fluid, air, hot-water boiler
"The article presents the results of creating a low-cost heat recovery system on the example of ""light"" of the gas infrared emitter by changing a single-layer thin-walled reflector to reflector upgraded on the principle of ""water jacket"" and the results of testing the effectiveness of modernized design on a specially designed stand. As a result, it was concluded that the streamlined design of the reflector gas infrared emitter will minimize the loss of heat towards the ceiling of the building and to avoid condensation on the inner surface of the roofs, a violation of the thermal regime, and as a consequence of premature failure of the roof and walling. In addition, through the use of exhaust heat for heating the coolant (water) flowing through a modernized reflector increases the efficiency of the system of gas infrared heating by 10%."
Keywords: Gas infrared heaters, efficiency, reflector, coolant
The article presents ecological heat and power recuperator for air heating. Due to the development of jet turbulent flow of the heating air, this device achieves positive heat exchange effect. It also allows reducing the noxious elements in combustion gases, exhausting into atmosphere.
Keywords: energy saving, ecology, heat-exchange, perforated surface, temperature, heat-exchange intensification
The article presents the results of an experimental research on the effect of the pulsating mode a capacitive heat exchanger with an active pipe part on the convective processes heated fluid. Described dignity capacitive heat exchangers. The research was conducted using a thermal imaging surveys. Compares two modes: stationary and pulsating. The method of experimental data processing, based on the analysis of fluid layers. A regression analysis allows to determine the dependence of the relative distribution of the temperature difference between the layers of fluid in the studied mode. The obtained regression equations were presented in the form of an exponential function and harmonic. The effect of pulsing regime on the process of convection in the upper quarter of the heating zone in a capacitive heat exchanger. The study showed the advantage of the capacitive heat exchanger with an active pipe part is often compared with the classical heat exchanger in part the speed of convective processes in the fluid to be heated.
Keywords: capacitive heat exchanger with an active pipe part, pulse heating system, convective process
In article authors considered the main processes having impact on distribution in atmospheric air of the polluting substances which are formed during the work of the enterprises of fuel and energy complex – boiler rooms and combined heat and power plant. Various changes to which are exposed gaseous and the strong polluting substances coming to the atmosphere with flue gases, and also the factors influencing dispersion and their concentration in the air basin of the cities are analysed. The climatic characteristics significantly influencing formation of pollution of the air basin of the cities are investigated. In the conclusion authors drew a conclusion that, despite an arrangement of installations of the centralized boiler rooms within an urban area or is close to it, decrease in pollution of the air basin of the cities in comparison with systems of autonomous heating of each house is observed.
Keywords: the polluting substances, the enterprises of fuel and energy complex, dispersion of the polluting substances, air pollution of the cities
In article authors considered organic types of fuel as the most widespread sources of obtaining thermal and electric energy at the enterprises of fuel and energy complex. The prevailing types of organic fuel – natural gas, coal, fuel oil are revealed, and also the composition of flue gases depending on a type of the burned organic fuel is analysed. So, when burning natural gas the main polluting substances are nitrogen oxides and carbon oxides. When burning liquid fuel oxides of sulfur and ashes are added to them. Coal burning, besides above-mentioned substances, leads to receipt to the air basin firm particles, particles (flying ashes) consisting from the zolovykh, not burned down solid fuel and soot. Negative impact of the enterprises of fuel and energy complex on environment components is investigated. In the conclusion authors drew a conclusion that, in comparison with other types of organic fuel, burning of natural gas does the minimum harm to environment.
Keywords: organic fuels, combustion, environmental pollution, exhaust gases, pollutants