scholarly journals Efficiency of night ventilation in limiting the overheating of passive sports hall

2020 ◽  
Vol 322 ◽  
pp. 01031
Author(s):  
Anna Dudzińska ◽  
Tomasz Kisilewicz
Keyword(s):  
Natural Ventilation ◽  
Simulation Analysis ◽  
Experimental Studies ◽  
Internal Heat ◽  
Thermal Conditions ◽  
External Temperature ◽  
Building Insulation ◽  
Microclimatic Conditions ◽  
Summer Time ◽  
Night Ventilation

It is especially difficult to provide optimal microclimatic conditions in sports facilities during summer time. The internal heat gains and an airtight building insulation, combined with high external temperature can easily lead to overheating and upsetting of the body's thermal balance. This article focuses primarily on the effect of natural night ventilation on the thermal comfort in a passive sports hall building. Based on experimental studies of thermal conditions in the hall, a simulation model was made using the Design Builder program. Through simulation analysis, the program considered thermal conditions that arise in various scenarios of natural and mechanical ventilation. Results presented in this article show that the natural ventilation at night in a large volume building is the most effective and the easiest way to reduce overheating in summer.

Experimental studies of iodine stationary plasma thruster

2019 ◽  
pp. 81-90
Author(s):  
Boris A. Sokolov ◽  
Pavel A. Shcherbina ◽  
Ivan B. Sishko ◽  
Aleksandr V. Shipovskiy Aleksandr ◽  
Aleksandr A. Lyapin ◽  
...  
Keyword(s):  
Experimental Studies ◽  
Thermal Conditions ◽  
Economic Viability ◽  
Electron Drift ◽  
Experimental Facility ◽  
Operational Mode ◽  
Stationary Plasma Thruster ◽  
Stationary Plasma ◽  
Plasma Thruster ◽  
Closed Electron

The paper demonstrates the feasibility of using iodine as propellant for thrusters with closed electron drift and its economic viability. It describes a test setup for running experiments. It provides the results of experimental studies of the stationary plasma thruster using iodine as its propellant with xenon gas-passage hollow cathode, as well as of the operational mode of the thruster where a mixture of xenon and iodine is used. During tests gas dynamic and electrical properties of the thruster were analyzed. Thermal conditions in the iodine storage and supply system were studied. Conclusions were drawn on how the test object could be improved and upgraded. The paper describes the option to use a thermionic non-flow cathode as the compensator cathode for the operation of the iodine thruster. The paper provides the results of an experimental study of the prototype non-flow compensator cathode in diode mode. Based on the results of the studies an experimental facility was built for testing a thruster with non-flow compensator cathode. Key words: cathode, compensator cathode, thruster with closed electron drift, stationary plasma thruster, iodine.

scholarly journals The Effect Of Outside Corridor’s Orientation to Interior Thermal Condition at Lawang Sewu Semarang.

2018 ◽  
Vol 73 ◽  
pp. 01011
Author(s):  
Benediktus Yosef Arya Wastunimpuna ◽  
Wahyu Setia Budi ◽  
Erni Setyowati
Keyword(s):  
Heat Stress ◽  
Relative Humidity ◽  
Thermal Condition ◽  
Natural Ventilation ◽  
Thermal Conditions ◽  
Standard Theory ◽  
Hot Wire ◽  
Air Movement ◽  
Dutch Colonial

The outside corridor of Dutch Colonial Building in Indonesia was made to make the temperature of the room more comfortable. Lawang Sewu Building in Semarang is one example of a building that has an outside corridor along the building and until now still use natural ventilation. This study focuses on finding out whether there is a difference on the thermal conditions of each room’s orientation, so after that we know the effect of orientation of the outdoor corridor to the temperature of the interior. In this study the experiment based on measurement using Heat Stress WBGT Meter for Wet Bulb Temperature, Dry Bulb Temperature, Relative Humidity, and KW0600653 Hot Wire Anemometer for the air movement. The data will be analysed using thermal standard theory to find out which point has the most comfortable thermal conditions.. At the end of this study will be found the effect of corridor’s orientation to thermal condition of the interior in Lawang Sewu Semarang.

Improving Sustainability of Housing in Ghana through Energy Efficient Climate Control Strategies

2012 ◽  
Vol 608-609 ◽  
pp. 1698-1704
Author(s):  
Abdul Manan Dauda ◽  
Hui Gao
Keyword(s):  
Natural Ventilation ◽  
Energy Savings ◽  
Control Strategies ◽  
Internal Heat ◽  
Climate Control ◽  
Housing Design ◽  
Artificial Lighting ◽  
Testing Procedures ◽  
Mass Housing ◽  
Design Changes

This paper aims at explaining testing procedures used to evaluate the potential of natural ventilation and daylighting applications to passive design of housing in Ghana. The objectives of research were to reduce energy costs and increase the sustainability of housing. From the results of these experiments actual and potential designs are illustrated and discussed. Mass housing results in multi-storey buildings which require substantial artificial lighting and ventilation. Also, with the increasing usage of glass for windows and doors in Ghana, even the shaded depths of buildings require additional daylight usually resulting in more energy consumption. By supplementing the internal lighting levels with daylight, reducing the internal heat load by shading windows to direct radiation and the utilization of natural ventilation over air conditioning where possible, significant energy savings are could be achieved. The research proposes mass housing design changes such as: delivering daylight above the suspended ceiling into the depths of the building by horizontal light pipes and natural ventilation, utilizing stack effect and wind siphonage, etc.

scholarly journals THEORETICAL RESEARCH OF THE EXTERNAL TEMPERATURE INFLUENCE ON THE TRACTION AND SPEED PROPERTIES AND THE FUEL ECONOMY OF CARGO-CARRYING VEHICLES

2020 ◽  
pp. 1-9
Author(s):  
Zhasur Kulmukhamedov ◽  
Ravshan Khikmatov ◽  
Alisher Saidumarov ◽  
Yulduz Kulmukhamedova
Keyword(s):  
Experimental Data ◽  
Fuel Economy ◽  
Experimental Studies ◽  
Statistical Processing ◽  
Research Data ◽  
Theoretical Research ◽  
Temperature Influence ◽  
External Temperature ◽  
Average Speed ◽  
The Mathematical Model

The manuscript proposes analytical methods for calculating fuel economy and traction-speed properties when modeling the movement of cargo-carrying vehicles on real routes, based on theoretical and experimental studies in a hot and dry climate, which allows for determining the efficiency of cargo-carrying vehicles objectively in terms of traction and speed, fuel and economic indicators. Using the statistical processing of experimental, theoretical research data, the authors calculate the coefficient X2, which allows for evaluating the adequacy of the mathematical model and experimental data. As an example, the manuscript provides for an assessment of fuel economy and traction and speed properties. The authors presented the results in graphs for the ease of evaluating the effect of external temperature on fuel consumption and the average speed of a road train. The authors’ methodology allows for determining the efficiency of cargo-carrying vehicles in a hot and dry climate.

Small and Full-Scale Modeling for the Application of Wall Solar Chimneys

2016 ◽  
Author(s):  
David Park ◽  
Francine Battaglia
Keyword(s):  
Natural Ventilation ◽  
Velocity Ratio ◽  
Thermal Conditions ◽  
Ambient Air ◽  
Full Scale ◽  
Scale Model ◽  
Small Scale ◽  
Solar Chimney ◽  
Window Position ◽  
Pi Theorem

A solar chimney is a natural ventilation technique that has a potential to save energy consumption as well as to maintain the air quality in the building. However, studies of buildings are often challenging due to their large sizes. The objective of the current study was to determine relationships between small- and full-scale solar chimney system models. In the current work, computational fluid dynamics (CFD) was utilized to model different building sizes with a solar chimney system, where the computational model was validated with the experimental study of Mathur et al. The window, which controls entrainment of ambient air, was also studied to determine the effects of window position. Correlations for average velocity ratio and non-dimensional temperature were consistent regardless of window position. Buckingham pi theorem was employed to further non-dimensionalize the important variables. Regression analysis was conducted to develop a mathematical model to predict a relationship among all of the variables, where the model agreed well with simulation results with an error of 2.33%. The study demonstrated that the flow and thermal conditions in larger buildings can be predicted from the small-scale model.

Energy Consumption Analysis on Office Building Ventilation

2012 ◽  
Vol 516-517 ◽  
pp. 1139-1143
Author(s):  
Ke Chun Sun ◽  
Wei Jun Zhang
Keyword(s):  
Energy Consumption ◽  
Energy Saving ◽  
Air Conditioning ◽  
Room Temperature ◽  
Simulation Analysis ◽  
Simulation Software ◽  
Energy Simulation ◽  
Office Building ◽  
Saving Effect ◽  
Night Ventilation

Chongqing weather conditions as the representative, energy simulation software DesT-c Chongqing office building energy simulation analysis, simulated natural building under different ventilation conditions at room temperature, the energy consumption of building cooling load and air-conditioning system changes, with an emphasis on energy-saving effect of the night ventilation; The study showed that in Chongqing reasonable use of ventilation reduce building natural room temperature to a certain extent; Sensitive indicators of building air conditioning energy consumption than the heating energy consumption of ventilation was significantly; Night ventilation when the number of ventilators is less than 5 times / h, the energy saving effect is very significant.

Development of a Predictive Equation for Ventilation in a Wall-Solar Chimney System

2017 ◽  
Vol 139 (3) ◽  
Author(s):  
David Park ◽  
Francine Battaglia
Keyword(s):  
Mathematical Model ◽  
Relative Error ◽  
Natural Ventilation ◽  
Thermal Conditions ◽  
Ambient Air ◽  
Maximum Error ◽  
Scale Model ◽  
Small Scale ◽  
Maximum Relative Error ◽  
Solar Chimney

A solar chimney is a natural ventilation technique that has potential to save energy consumption as well as to maintain the air quality in a building. However, studies of buildings are often challenging due to their large sizes. The objective of this study was to determine the relationships between small- and full-scale solar chimney system models. Computational fluid dynamics (CFD) was employed to model different building sizes with a wall-solar chimney utilizing a validated model. The window, which controls entrainment of ambient air for ventilation, was also studied to determine the effects of window position. A set of nondimensional parameters were identified to describe the important features of the chimney configuration, window configuration, temperature changes, and solar radiation. Regression analysis was employed to develop a mathematical model to predict velocity and air changes per hour, where the model agreed well with CFD results yielding a maximum relative error of 1.2% and with experiments for a maximum error of 3.1%. Additional wall-solar chimney data were tested using the mathematical model based on random conditions (e.g., geometry, solar intensity), and the overall relative error was less than 6%. The study demonstrated that the flow and thermal conditions in larger buildings can be predicted from the small-scale model, and that the newly developed mathematical equation can be used to predict ventilation conditions for a wall-solar chimney.

Experimental Studies of Hydrodynamics and Heat Transfer in Channels With High-Porous Cellular Materials in Single-Phase Forced Convection and Flow Boiling of Working Fluids

1999 ◽  
Author(s):  
Yury F. Gortyshov ◽  
Igor A. Popov ◽  
Konstantin E. Gulitsky
Keyword(s):  
Heat Transfer ◽  
Single Phase ◽  
Pore Diameter ◽  
Flow Boiling ◽  
Experimental Studies ◽  
Internal Heat ◽  
Cellular Materials ◽  
Heat Fluxes ◽  
Working Fluids ◽  
Resistance Surface

Abstract In this paper we consider experimental studies of hydraulic resistance, surface heat transfer, internal heat exchange and critical heat fluxes for the flow of single-phase and boiling working fluids in channels with high-porous inserts. Experiments were carried out with more than 40 samples of high-porous cellular materials with the porosity 0.8...0.98 and mean pore diameter 0.62...4 mm and with more than 10 samples of regular porous inserts and porosity ε = 0.512...0.86 and mean pore diameter 1.5...3.5 mm. These samples were made of porcelain, invar, nichrome, bronze and copper.

Second Law Analysis of a Stirling Cryocooler With Optimal Design of the Regenerator and Losses

2001 ◽  
Author(s):  
E. D. Rogdakis ◽  
N. A. Bormpilas
Keyword(s):  
Gas Flow ◽  
Optimization Technique ◽  
Internal Heat ◽  
Thermodynamic Characteristics ◽  
Coefficient Of Performance ◽  
Solid Matrix ◽  
Second Law ◽  
External Temperature ◽  
Technical Requirements ◽  
Second Law Analysis

Abstract The aim of the research in this paper is a second law analysis of a Stirling cryocooler. A one-dimensional model is proposed for the simulation of the gas flow in the expansion space, the regenerator, the warm-end, the compression space and the compressor. Helium gas is selected as the working medium. An algorithm has been developed considering parametrically the most from the main operational tasks of the thermodynamic cycle. Performance indices such as heat input, efficiency, external dimensions of the engine and technical requirements are taken into account as constraints. Engine operating parameters i.e. speed, external temperature, mean pressure are fixed. The regenerator loss has a critical influence on the cryocooler efficiency and the reduction of this kind of internal irreversibilities is extremely difficult due to the generator is subject to rapidly cycling flows accompanied by steep temperature gradients and large pressure variations. The second flow analysis of the regenerator identifies two principal losses, the irreversible internal heat transfer into the solid matrix and the hydraulic resistance. An optimization technique leads to entropy generation charts, extremely useful for a good design of the regenerator. Finally the main thermodynamic characteristics (net refrigeration, power input and the coefficient of performance) of the cryocooler are given both cases with and without external and internal irreversibilities.

Graph-Analytical Estimation Method of Natural Ventilation Efficiency during Natural Gas Combustion

2018 ◽  
Vol 931 ◽  
pp. 901-904 ◽  
Author(s):  
Victor I. Chebotarev ◽  
Anastasia P. Pirozhnikova ◽  
Alla V. Koroleva
Keyword(s):  
Natural Gas ◽  
Natural Ventilation ◽  
Theoretical Calculations ◽  
Residential Buildings ◽  
Experimental Studies ◽  
Estimation Method ◽  
Combustion Products ◽  
Gas Combustion ◽  
Analytical Estimation ◽  
Ventilation Duct

Open burning of natural gas when using gas equipment in the premises of residential buildings is considered, taking into account the formation of combustion products, depending on the coefficients of excess air. Theoretical and experimental studies of combustion processes are presented. To determine the aerodynamic process in the ventilation duct, theoretical calculations of the dependence of the discharge at the entrance to the ventilation duct from the outside temperature of the atmospheric air were made. Graph-analytic method of evaluating the effectiveness of natural ventilation is carried out.

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