scholarly journals Method of the boiler room ventilation system efficiency experimental determination

2020 ◽  
pp. 71-81
Author(s):  
O. Voznyak ◽  
◽  
Yu. Yurkevych ◽  
M. Kasynets ◽  
N. Spodyniuk ◽  
...  
Keyword(s):  
Experimental Determination ◽  
Ventilation System ◽  
Experimental Studies ◽  
Regulatory Requirements ◽  
Air Jets ◽  
Boiler Room ◽  
Room Ventilation System ◽  
Air Flow Velocity ◽  
Air Exchange

The issue of the normative air exchange ensuring in the premises of the boiler houses is extremely important. The article presents the results of theoretical and experimental studies of air velocity determination in the distribution of air by round and compact jets in the boiler room. Graphical and analytical dependences are given. The research results substantiate the higher accuracy of the average air flow velocity determination in small boiler rooms. The aim of the work is to develop a method for experimental determination of the efficiency of the ventilation system in the boiler room; to increase of the accuracy of the average velocity determination of the round and the compact air jets in the plane of the supply nozzle to ensure the normative air exchange of the boiler room and to substantiate of the calculation method. The characteristics and patterns of development of round and compact air jets in the premises are established and the calculated dependences are obtained. It is substantiated that the application of the proposed method will significantly increase the accuracy of air exchange determination in the boiler rooms to ensure the required value in accordance with regulatory requirements. Recommendations for the practical determination of the calculated values to ensure proper ventilation of the boiler rooms are given.

scholarly journals Method of the boiler room ventilation system efficiency experimental determination

2020 ◽  
Vol 2020 (2) ◽  
pp. 84-91
Author(s):  
Orest Voznyak ◽  
◽  
Yuriy Yurkevych ◽  
Iryna Sukholova ◽  
Oleksandr Dovbush ◽  
...  
Keyword(s):  
Experimental Determination ◽  
Average Velocity ◽  
Air Flow ◽  
Ventilation System ◽  
Experimental Studies ◽  
Air Velocity ◽  
Air Jets ◽  
Boiler Room ◽  
Air Exchange

The issue of the normative air exchange ensuring in the premises of the boiler houses is extremely important. The article presents the results of theoretical and experimental studies of air velocity determination in the distribution of air by round and compact jets in the boiler room. Graphical and analytical dependences are given. The research results substantiate the higher accuracy of the average air flow velocity determination in small boiler rooms. The aim of the work is to develop a method for experimental determination of the efficiency of the ventilation system in the boiler room; to increase of the accuracy of the average velocity determination of the round and the compact air jets in the plane of the supply nozzle to ensure the normative air exchange of the boiler room and to substantiate of the calculation method. The characteristics and patterns of development of round and compact air jets in the premises are established and the calculated dependences are obtained. The unitless integral air velocity for the round and compact air jets in the boiler room is established. Calculation dependences for determining of the air flow rate in the boiler room have been obtained. It is substantiated that the application of the proposed method will significantly increase the accuracy of air exchange determination in the boiler rooms to ensure the required value in accordance with regulatory requirements. Also it is substantiated that to obtain satisfactory experimental results on speed measurements in the boiler room, it is necessary to measure the speed in the center of the supply nozzle several times with maximum accuracy. Then multiply the result by the relative average velocity: for a round jet vav = 0,26 and for a compact jet – vav = 0,2025. The obtained results allow to avoid a significant error (19 %) in determining the required air exchange ventilation of the boiler room. Recommendations for the practical determination of the calculated values to ensure proper ventilation of the boiler rooms are given.

EXPERIMENTAL STUDIES OF REINFORCED CONCRETE STRUCTURES WITH CROSS-SHAPED SPATIAL CRACK UNDER TORSION WITH BENDING

2020 ◽  
Vol 92 (6) ◽  
pp. 13-25
Author(s):  
Vl.I. KOLCHUNOV ◽  
◽  
A.I. DEMYANOV ◽  
M.M. MIHAILOV ◽  
◽  
...  
Keyword(s):  
Reinforced Concrete ◽  
Experimental Determination ◽  
Calculation Method ◽  
Experimental Studies ◽  
Concrete Structures ◽  
Design Parameters ◽  
Reinforced Concrete Structures ◽  
Experimental Scheme

The article offers a method and program for experimental studies of reinforced concrete structures with cross-shaped spatial crack under torsion with bending, the main purpose of which is to check the design assumptions and experimental determination of the design parameters of the proposed calculation method. The conducted experimental studies provide an opportunity to test the proposed calculation apparatus and clarify the regularities for determining deflections, angles of rotation of extreme sections, and stresses in the compressed zone of concrete. For analysis, the article presents a typical experimental scheme for the formation and development of cracks in the form of a sweep, as well as characteristic graphs of the dependence of the angles of rotation of end sections.

Experimental Studies of Force Systems on Steered Agricultural Tyres

1966 ◽  
Vol 181 (1) ◽  
pp. 133-148 ◽  
Author(s):  
P. A. Taylor ◽  
R. Birtwistle
Keyword(s):  
Experimental Determination ◽  
Experimental Studies ◽  
Soil Surface ◽  
Slip Angle ◽  
Vertical Load ◽  
Force Systems

The paper reports the experimental determination of the force systems acting on free-rolling 7–50 times 16 agricultural tyres, measured with a six-component suspension of the test wheel. Multivariate experimentation techniques were used involving five variables: slip angle, camber, vertical load, tyre pattern and land or furrow operation. The results are presented as three force and three moment components; other methods of representation are discussed briefly. Although the side or cornering force depends on many factors, particularly the soil surface, and is therefore difficult to predict, it is suggested that the draught force (i.e. resistance in the direction of motion) can be expressed as a function of slip for all surfaces.

Modern Regulatory Requirements for Gas Fire Extinguishing to Improve the Safety of Facilities

2020 ◽  
pp. 55-60
Author(s):  
N.V. Smirnov ◽  
◽  
A.V. Kazakov ◽  
D.V. Bukhtoyarov ◽  
◽  
...  
Keyword(s):  
Experimental Studies ◽  
Combustion Time ◽  
Regulatory Requirements ◽  
Fire Extinguishing ◽  
Eurasian Economic Union ◽  
Flammable Liquids ◽  
Fire Experiment ◽  
Economic Union ◽  
Selection Of

To implement the technical regulations of the Eurasian Economic Union «On the requirements for fire safety and fire extinguishing equipment» (TR EAEU 043/2017), modern regulatory requirements were developed based on the advanced domestic and foreign research in order to increase the efficiency of using automatic gas fire extinguishing installations. The domestic methodology of experimental determination of the gas extinguishing concentration in the fire chamber has a number of advantages in comparison with the foreign analogues. It is established that it is necessary to take into account the conditions of fire experience for the selection of equipment for a fire extinguishing installation with FK-5-1-12 in the process of its design, in order to ensure more complete evaporation of the liquid phase of FK-5-1-12 after leaving the nozzles. An assumption was substantiated that allows setting the normative concentration of fire extinguishing gases at the level of heptane without conducting a fire experiment to extinguish fires of flammable liquids with a flash point of more than 61 оC. In this case, the concentration value can be taken 15 % less than according to the requirements of ISO 12854: 2009. Experimental studies on extinguishing smoldering materials with gases were conducted. It was established that nitrogen, CO2, freons 114B2 and 227ea at a concentration for extinguishing heptane eliminate not only flame combustion, but also smoldering if the free combustion time does not exceed 3 min. With free combustion for more than 6 minutes, reliable suppression of smoldering is achieved when the oxygen content in the volume of the fire chamber is up to 2.5 % vol. The results of the experiments were taken into account in the draft norms for the design of fire extinguishing installations. Additional requirements were developed for gas fire extinguishing containers and selector valves, which will make it possible to exclude the use of low-quality or obsolete products as part of gas fire extinguishing installations in the territory of the Eurasian Economic Union. The developed modern requirements are included in the drafts of new regulatory documents, which were publicly discussed, and are at the approval stage.

Review of new requirements for smoke ventilation system for road tunnels in NFPA 502 published in 2020

2020 ◽  
pp. 16-25
Author(s):  
Борис Борисович Колчев ◽  
Андрей Владимирович Пехотиков ◽  
Игорь Иванович Ильминский ◽  
Павел Алексеевич Чернышов ◽  
Оксана Владимировна Фомина
Keyword(s):  
Ventilation System ◽  
Significant Discrepancy ◽  
Limited Access ◽  
Fire Extinguishing ◽  
Release Capacity ◽  
Road Tunnels ◽  
Air Intake ◽  
Air Flow Velocity ◽  
Heat Release Capacity

Одним из нормативных документов, содержащих основные требования к системам противодымной вентиляции автодорожных тоннелей, является NFPA 502 «Standard for Road Tunnels, Bridges and Limited Access Highways». Стандарт обобщает накопленный опыт, полученный в результате экспериментальных исследований, проводимых как в США, так и за их пределами. В августе 2019 г. была опубликована его новая редакция (2020 Edition), в которой значительно изменился подход к определению требуемых параметров противодымной вентиляции, основанной на продольной схеме. The article presents an analysis of the new edition of NFPA 502 “Standard for Road Tunnels, Bridges, and Limited Access Highways” regarding the method for determining the critical value of the longitudinal air flow velocity generated by smoke ventilation based on longitudinal scheme. The classification of road tunnels introduced by NFPA 502 is described, taking into account the occupancy of tunnels by vehicles during rush hour, as well as the length of the tunnel. The data concerning protection of tunnel by fire protection systems taking into account the introduced classification are presented. There are analysed the schemes of smoke ventilation, including longitudinal, semi-transverse and transverse, containing different number of concentrated and distributed smoke receiving and air intake devices introduced by NFPA 502. There is described the effect of trapping air from under the smoke layer, that is called as “Plugholing” effect in the standard. The data on heat release capacity from fire source are presented taking into account various types of burning vehicles, as well as the equipment of tunnel with automatic fire extinguishing systems. There is performed the comparison of results of the calculated determination of critical velocity, determined by the dependencies of NFPA 502 in 2017 and 2020 editions. The significant discrepancy in required values is found.

Calculated-Experimental Determination of Values Natural Frequencies Oscillations of the Case and Parameters of the Case Determining these Values

2019 ◽  
pp. 89-104
Author(s):  
A.V. Proskurin ◽  
A.V. Shlishevskiy
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Experimental Determination ◽  
Analytical Solutions ◽  
Natural Frequencies ◽  
Experimental Studies ◽  
The Body ◽  
Design Parameters ◽  
The Finite Element Method

The task of studying the behavior of various structures under the influence of intense pulsed (shock) loads that arise during the operation of many modern structures, machines and devices remains relevant for many years. One of the stages of this study is to find the values of the natural frequencies of vibrations and design parameters that determine these values. To find the natural frequencies of oscillations of the body, which are four flanges connected by cylindrical shells, the finite element method and analytical solutions were used. An analysis of experimental studies. Determination of natural frequencies values and design parameters determining these values will allow evaluating the response of the structure to the loads acting during its operation, and making corrections to the structure that change the response of the structure, as well as will help to more accurately select the installation sites of piezoelectric accelerometers for recording drums accelerations.

scholarly journals EXPERIMENTAL DETERMINATION OF THE LEVEL OF INCIPIENT TURBULENCE IN THE WORKING PART OF THE T-1 WIND TUNNEL OF IVAN KOZHEDUB KHARKIV NATIONAL AIR FORCE UNIVERSITY

2021 ◽  
Vol 5 (2) ◽  
pp. 98-102
Author(s):  
Віталій Бездєльний ◽  
Сергій Шевченко ◽  
Ілля Грідасов
Keyword(s):  
Experimental Study ◽  
Pressure Drop ◽  
Wind Tunnel ◽  
Experimental Determination ◽  
Air Force ◽  
Normal Condition ◽  
Aerodynamic Drag ◽  
Experimental Studies ◽  
The Subject

The subject of the article is to determine the level of incipient turbulence in the wind tunnel T-1 which is based on the method of measuring the pressure drop. The purpose is to experimentally determine the level of incipient turbulence in the working part of wind tunnel T-1 of Ivan Kozhedub Kharkiv National Air Force University in preparation for aerodynamic testing of aircraft models. Research methods: the method of pressure drop on the surface of the sphere by drainage. The following results of experimental determination of the level of incipient turbulence in the wind tunnel T-1 were obtained. It is established that the wind tunnel T-1 has a level of incipient turbulence 0,5…0,9 %, which corresponds to the normal condition for further experimental studies. Conclusions. According to the results of studies of the incipient turbulence in the wind tunnel T-1 by the method of pressure drop, the main dependences are obtained, and the incipient turbulence of the flow for the wooden sphere x = 0,9 %, and for the metal sphere x = 0,5 %, is determined. Determining the pressure distribution and aerodynamic drag does not involve measures to balance the aerodynamic scales and their certification, which determines the necessary role in the obtained reliable results of the experimental study, and this favors the drainage method.

scholarly journals The heat supply object thermal regime under conditions of gas infrared emitter and air exchange system joint operation

2021 ◽  
Vol 2119 (1) ◽  
pp. 012091
Author(s):  
G V Kuznetsov ◽  
V I Maksimov ◽  
T A Nagornova ◽  
A V Vyatkin
Keyword(s):  
Ventilation System ◽  
Temperature Drop ◽  
Experimental Studies ◽  
Heat Fluxes ◽  
Joint Operation ◽  
Exchange System ◽  
Infrared Emitters ◽  
Infrared Emitter ◽  
Favorable Temperature ◽  
Air Exchange

Abstract The paper presents the results of experimental studies on the formation of thermal comfort conditions in large premises with the joint operation of gas infrared emitters and air exchange ventilation system. The values of temperatures and heat fluxes on the clothing surface under natural and mixed convection conditions were obtained. It has been established that the air exchange system operation in the premises reduces the temperature drop of the person clothes surface, respectively, a more favorable temperature condition is achieved in the working area.

Experimental Determination and Modeling of Desorption Isotherms of the Tomato "Lycopersicum esculentum"

2021 ◽  
pp. 24-31
Author(s):  
Roland Lankouande ◽  
G. Gilbert Nana ◽  
Souleymane Ouedraogo ◽  
Kalifa Palm ◽  
Frédéric Ouattara ◽  
...  
Keyword(s):  
Experimental Determination ◽  
Experimental Studies ◽  
Gravimetric Method ◽  
Sorption Isotherms ◽  
Storage Conditions ◽  
Market Place ◽  
Desorption Isotherms ◽  
Final Water Content ◽  
The Stability

The aim of this work is to make a contribution to the drying of tomatoes. The purpose of this contribution is the experimental determination of the desorption isotherms of a variety of tomato (one of the most widespread on the Burkinabe market place) using the static gravimetric method at temperatures of 25°C, 40°C and 50°C. It is more specifically a question of validating a theoretical model based on these experimental studies. Sorption isotherms allow us to have information to establish the stability of food products and their storage conditions. These isotherms are curves which give valuable information on the hygroscopic balance of a product because they allow to know its range of stability after drying by determining the final water content.

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