75504
2712-8172
Magazine of Civil Engineering
2
28
2012
1-84
RAR
RUS
2-7
Kuznetsov
Geniy
Tomsk polytechnic university
elf@tpu.ru
Polovnikov
Vyacheslav
National Research Tomsk Polytechnic University
polov@tpu.ru
Heat loss of underground channel heat pipelines with strained thermal insulation layer, taking into account radiative heat transfer in the cavity of the channel
The weakest places of centralized heating systems are the pipelines. Heat pipe network systems, built in the USSR, are characterized by low reliability, high damage possibility and large heat losses. The main reasons for the heat losses growth are moisture, deformation and breakage of the thermal insulation layer. The purpose of this paper is to assess the extent of underground channel pipelines with strained thermal insulation layer heat losses, taking into account radiative heat transfer in the cavity of the channel. During the work the numerical analysis of thermal insulation layer deformation effect and radiation heat transfer in the cavity of the channel influence on thermal conditions and heat losses of underground channel pipelines was achieved. On the basis of these results the perspective of the developed model and numerical analysis techniques for the extent of pipelines with deformed thermal insulation heat losses evaluation was determined.
10.5862/MCE.28.1
mathematical modeling
heat pipeline
heat losses
heat insulation
https://engstroy.spbstu.ru/article/2012.28.1/
01.pdf
RAR
RUS
9-17
Motuzienė
V.
Vilnius Gediminas Technical University
Valančius
K.
Vilnius Gediminas Technical University
Rynkun
Genrika
Vilnius Gediminas Technical University
pastatu.energetika@vgtu.lt
Complex Analysis of Energy Efficiency of public buildings: case study of VGTU
The purpose of this work was to make analysis of energy efficiency of Vilnius Gediminas Technical University (VGTU) buildings. The survey was performed within the frame of the Intelligent Energy – Europe (IEE) project “Use Efficiency” – Universities and Students for Energy Efficiency. The methodology of the detailed auditing proves that energy audits must be performed with the maximum use of measurements. When having main parameters measured, it is much exact and easier to form energy balance of the building. It has been inferred that performing detailed energy audits with the support of measurements enable to asses building’s present energy efficiency very precise and consequently savings, related to the proposed energy saving measures, can be assessed more realistic than just analytical calculations. The analysis performed consists of 2 levels: the 1st and the 2nd level audits. During the 1st level audits, according to the operational energy, critical buildings were identified. The 2nd level audits contain a detailed analysis of the energy efficiency of the buildings and are based on different measurements and analytical calculations (performed according to the national methodology). This analysis could be a guideline for others performing this type of investigations.
10.5862/MCE.28.2
energy efficiency
public buildings
energy audits
indoor climate
elements thermal characteristics
measurements
economical evaluation
https://engstroy.spbstu.ru/article/2012.28.2/
02.pdf
RAR
RUS
18-23
56352359500
0000-0002-5156-7352
Sergey
Korniyenko
Volgograd State Technical University
svkorn2009@yandex.ru
28, Lenina Ave., Volgograd, Russia, 400005
Testing of calculation method of the enclosing structures temperature-humidity conditions on the results of indoor climate in-situ measurements
The problem of energy expenses decreasing and buildings energy efficiency growth is closely connected with necessity of heat and mass exchange processes research, forecasting of the enclosing structures temperature-humidity conditions and increasing of heat engineering calculations reliability. In this article the results of indoor climate parameters in-situ measurements are used for testing the method of temperature-humidity conditions calculation in three-dimensional areas of enclosing structures developed by the author. Testing of this method confirms its veracity that allows to use the specified method in design practice.
10.5862/MCE.28.3
temperature-humidity conditions of enclosing structures
indoor climate parameters
computer program
https://engstroy.spbstu.ru/article/2012.28.3/
03.pdf
RAR
RUS
24-31
Petrosova
Daria
Air filtering through the building envelope
Recently, building envelopes with efficient insulation of low thermal conductivity, including light building envelope, which allow to increase thermal protection of buildings, are widely used. This new building envelope require a comprehensive study, because previously considered unimportant features often start to make significant effect on the performance characteristics of structures. To reduce the air permeability in the constructions wind-proof membranes are used. However, the influence of air filtering in such structures has not been researched yet. When the air-permeable building envelopes are used, the heat flow is moved away also due to the air filtering. It is proposed to take into account the convective heat transfer mechanism commensurate with the conductive heat transfer mechanism. In the formula for determining the heat flow due to the air filtering the filtration coefficient of air through the building envelope is used. This coefficient is found experimentally for light building envelopes. Furthermore, the empirical expression for the filtration coefficient, which relates it and the coefficient of heat loss is found.
10.5862/MCE.28.4
air permeability
air filtering
building envelope
filtration rate
cross filtering
filtering heat transfer
https://engstroy.spbstu.ru/article/2012.28.4/
04.pdf
RAR
RUS
32-38
Sotnikov
Anatoliy
Nonprofit partnership “AVOK – Severo-Zapad”
asotnikov2005@yandex.ru
Borovitskiy
Andrey
Vladimir State University
borovitsk@mail.ru
Theoretical and experimental validation of the air changes in industrial ventilation optimization method
Wide dissemination and development of industrial ventilation of different industries, which began in our country from the period of industrialization of the 30s years of the twentieth century has led to significant scientific and practical achievements noted in numerous books and articles. It also has a positive effect on the health of manufactures staff. More than 2.5 thousand different harmful substances and local suctions from them were investigated in detail by hygienists and engineers in the USSR, in Russia and abroad, but, unfortunately, have not been systematized and generalized. This article tries to make such generalization, corroborated by analytical relationships and dependencies experienced by different authors. This technique is based on the exponential-power dependence for the effectiveness of local suction, which is close to dependence, accepted in the study of turbulent diffusion, but in more general terms. The proposed in the article new term equivalent-effective rate is rather universal concept, which allows to compare the effectiveness of hazards trapping for different design, technological and aerodynamic parameters of the source and the suction of any kind. On the basis of this idea, an opportunity of the ventilation systems in industrial ventilation for numerous industrial processes optimization appeared. As a result of using this method the capital and operating costs for the equipment of these systems, steam curing, and air movement could be reduced, thereby significant technical and economic effect could be provided.
10.5862/MCE.28.5
air exchange
the harmfulness
concentration
local suction
efficiency
optimization
ventilation
minimum of the function
equivalent-effective rate
https://engstroy.spbstu.ru/article/2012.28.5/
05.pdf
RAR
RUS
39-47
Absalyamov
Damir
Military and Spaсe Academy named after A. F. Mojaiskiy
damir73@yandex.ru
Improving the engineering systems reliability by formalizing the failure search
In the article a method of the failures search formalizing by efficiency indicators of energy resources in heating, ventilation and air conditioning of buildings and structures is proposed. The main feature of this method is the combination of the educational process and the procedure of selecting a minimal set of controlled parameters. In the framework of the method a way of training patterns grouping and groups ranking in order to accelerate the convergence of the learning process, as well as the modification of training procedures at low volume and lack of a priori information about the system is considered. The solution of the problem of choosing a minimal set of controlled parameters is based on the properties of orthogonal vector systems.
10.5862/MCE.28.6
learning procedure
denial
a controlled rate
training set
the recurrence relation
an orthonormal basis
https://engstroy.spbstu.ru/article/2012.28.6/
06.pdf
RAR
RUS
48-50
0000-0003-2533-9732
Samarin
Oleg
National Research Moscow State Civil Engineering University
samarin-oleg@mail.ru
Azivskaya
S.
Moscow State University of Civil Engineering
The influence of control algorithm on the annual energy consumption of automated climate systems
In the paper the estimation of energy consumption of the automated ventilating systems and air conditionings (V and AC) under condition of their regulation "on deviation" is reviewed. The analysis of processes descending in V and AC and maintained room is given. The outcomes of numerical calculation of a non-steady thermal mode of a room with the computer program designed by authors are adduced. Calculations were organized on different combinations of radiant and convective components of variable heat ingress. The optimal control algorithm of V and AC from the point of view of minimal general energy consumption during the heating system is found. The presentation is illustrated by a graphic stuff and by a numerical example of technical and economical estimation of optimal control algorithm using.
10.5862/MCE.28.7
automatic control system
power consumption
control algorithm
investment costs
operating costs
https://engstroy.spbstu.ru/article/2012.28.7/
07.pdf
RAR
RUS
51-55
Kalyakin
Aleksandr
Yuri Gagarin State Technical University or Saratov
elevadim@gmail.com
Chesnokova
Elena
Yuri Gagarin State Technical University or Saratov
adamas.elena@gmail.com
New relationship for determining the coefficient of hydraulic resistance in the transition zone of resistance (from laminar to turbulent flow)
To determine the pressure loss of liquids in pipelines during the transition from laminar to turbulent motion several dependencies for the coefficient of hydraulic friction are found. They are the dependencies of the ratio from the Re number of and can be obtained in the form of a segment of a series from three or four terms. The implementation of the process can be performed either by using elementary computational devices, and using the computer program. Upper and lower Reynolds numbers are set arbitrarily, taking into account the working conditions of the pipeline. Method was experimentally confirmed. The results could be applied in the design of construction machinery and equipment of average power operating at high frequency vibrations. Dependences for the coefficient of hydraulic friction are applied for the calculations of pipelines for liquid mixes.
10.5862/MCE.28.8
coefficient of hydraulic friction
transition zone
the pressure drop
Reynolds number
coupling curves
https://engstroy.spbstu.ru/article/2012.28.8/
08.pdf
RAR
RUS
56-60
Mikhalev
Mikhail
Peter the Great Saint Petersburg Polytechnic University
mikhalev@cef.spbstu.ru
Polytechnicheskay, 29
Free flow velocity of high-drag particles in liquid
This article discusses the phenomenon of free movement of buffle bodies in a fluid. The basis of hydraulic design of many technical devices (septic tanks, aeration and flotation chambers, hydro-and pneumatic transport, etc.) is the deposition rate (or floating) of the various bodies in the fluid. The solution of objective is obtained by the methods of mathematical modeling only at very low Reynolds numbers. Physical modeling of the phenomena is based on the results of fixed bodies flowed by oncoming external flow study. But from the standpoint of modern physical modeling methods the body, which moves freely, and the fixed body, streamlined at the same rate, represent two different phenomena: at the first variant speed is not known beforehand, at the second - it is originally given. Consequently, at the first variant there is no criterion between similarity numbers. The paper shows how the criteria are obtained from similarity numbers. Decisions are based on the similarity theory.The numbers, similarity criteria and criterial equations are determined. Proposed dependences have generalizing properties, if the conditions belong to the same class. In case of equal numbers of similarity, such phenomena are described by the same dependencies. They include: deposition of heavy particles in the air and water environments, the water droplets in the air, floating bubbles in the water, etc.
10.5862/MCE.28.9
physical modeling
settling velocity
numbers of similarity
criteria of similarity
criteria equation
https://engstroy.spbstu.ru/article/2012.28.9/
09.pdf
RAR
RUS
61-67
Miltsin
Dmitriy
The Volga State Academy of Water Transport
mantikor5@rambler.ru
Dynamics of the water flow, appearing during navigation lock chamber drawdown
Increasing the capacity of navigation locks is a very important sector of the Russian Federation inland waterway transport development. One of its directions is the structure of the flow in the navigation lock discharge system investigation,using modern methods of mathematical modeling. Calculations on the numerical model, described in this paper, allow to analyze the hydrodynamics of water flow that occurs when the chamber is drawdowned, and evaluate the work of flow energy quenching system at the outlet of the tailrace. This article presents a standard dampers design and their disadvantages, two new flow energy dissipation systems are proposed. The high efficiency of these systems (in comparison with already existing systems) is proved by mathematical modeling, their using can significantly improve the vessels placing conditions and increase the capacity of navigation facilities.
10.5862/MCE.28.10
navigation lock drawdown system
mathematical modeling
flow hydrodynamics
https://engstroy.spbstu.ru/article/2012.28.10/
10.pdf