scholarly journals МЕТОД ОПТИМІЗАЦІЇ ПРИ ПРОЕКТУВАННІ ПОВІТРЯНИХ РОЗПОДІЛЬНИХ МЕРЕЖ ЕНЕРГЕТИЧНИХ СИСТЕМ ЛІТАКА

2019 ◽  
pp. 119-135
Author(s):  
В. Ф. Шмырев ◽  
А. Д. Донец
Keyword(s):  
System Reliability ◽  
Air Conditioning ◽  
Distribution Systems ◽  
Mechanical Energy ◽  
Heating System ◽  
Structure Design ◽  
Geometric Constraints ◽  
Air Distribution ◽  
Working Medium ◽  
Pressurization System

Augmentation of the flight range, speed and altitude along with the extension of the number of missions accomplished by aircraft has resulted in the expansion and complication of the functions performed by the aircraft air distribution systems. Thus, for instance, the air distribution system of a modern transport airplane  includes:-        cabin air conditioning system;-        underfloor area heating system;-        wing ice protection and fuel tank venting system; -        engine air intake ice protection system;-        engine pneumatic starting system;-        the system of controlled air extraction from the equipment/avionics compartment;-        hydraulic tank pressurization system;-        turbine-driven hydraulic pump drive;-        radio equipment and radar pressurization system;       -        auxiliary power unit compartment heating system;-        cabins air conditioning using ground sources;-        cabins ventilation using atmospheric air;-        air supply for inert gas generation  In terms of structure design the aircraft air systems are a complex of heat exchange mechanisms, cooling turbines, compressors, filters, limiters and regulators, mixers, pipelines and other components interacting with each other and with the environment through the exchange of  the flows of working media, heat and mechanical energy. The system purpose is implemented in the  process of its functioning which implies on-board generation of working medium and its supply to consumers with the quantity and quality of the medium conditioned by external characteristics.  External characteristic is a quantification of the purpose of system functioning.  As an engineering entity the air distribution systems are characterized  by a number of functional indicators. These include the system reliability and weight, expenditure of energy and working medium, overall dimensions,  external energy release, factor of safety, cost, etc.  In the practical development of air distribution systems, when meeting the cooling performance requirements  use is later made, as a general rule, of such indicator as "installation weight", less frequently – of the integrated "reduced" weight indicator with introduction of limitations on other indicators. Designing the air distribution systems involves lookup for a compromise between a number of conflicting requirements: minimization of the installation weight and energy losses, high system reliability, fail safety, rigorous geometric constraints, high manufacturability and comparatively low cost of production. Application of the mathematical statics techniques makes it possible to optimize parameters of the air system. 

scholarly journals Some Aspects of HVAC Design in Energy Renovation of Buildings

2021 ◽  
Author(s):  
Taghi Karimipanah
Keyword(s):  
Renewable Energy ◽  
Air Conditioning ◽  
Distribution Systems ◽  
Energy System ◽  
Building Energy ◽  
Hvac Systems ◽  
Heat Losses ◽  
Energy Sources ◽  
Air Distribution ◽  
Building Energy System

It is well-known fact that air conditioning systems are responsible for a significant part of all energy systems in building energy usage. In EU buildings, the building HVAC systems account for ca 50% of the energy consumed. In the U.S., air-conditioning accounts on average about 12% of residential energy expenditures. The proper choice of air distribution systems and sustainable energy sources to drive the electrical components have a vital impact to achieve the best requirements for indoor climate including, hygienical, thermal, and reasonable energy-saving goals. The building energy system components that have a considerable impact on the demand for final energy in the building are design, outdoor environment conditions, HVAC systems, water consumption, electrical appliances, indoor thermal comfort, and indoor human activities. For calculation of the energy balance in a building, we need to consider the total energy flows in and out from the building including ventilation heat losses, the perimeters transmission heat loses, solar radiation, internal heat from occupants and appliances, space and domestic water heating, air leakage, and sewage heat losses. However, it is a difficult task to handle the above time-dependent parameters therefore an energy simulation program will always be used. This chapter aims to assess the role of ventilation and air-conditioning of buildings through the sustainability approaches and some of the existing renewable energy-based methods of HVAC systems are presented. This comprehensive review has been shown that using the new air distribution systems in combination with renewable energy sources are key factors to improve the HVAC performance and move toward Nearly Zero Carbon Buildings (NZCB).

scholarly journals New Approach for Refined Efficiency Estimation of Air Exchange Organization

2018 ◽  
Vol 7 (3.2) ◽  
pp. 591
Author(s):  
Volodymyr Dovhaliuk ◽  
Viktor Mileikovskyi ◽  
. .
Keyword(s):  
Energy Efficiency ◽  
Turbulence Intensity ◽  
Air Conditioning ◽  
Mechanical Energy ◽  
Air Distribution ◽  
New Approach ◽  
Air Volume ◽  
Efficiency Estimation ◽  
Special Approach ◽  
Air Exchange

In the modern conditions, energy efficiency is one of the most important world problems. One of the important factors influencing the overall energy efficiency of buildings is air distribution in rooms. Literature review shows different options of efficiency estimation of air exchange with significant limitations. Some of them have non-obvious physical meaning. Certain of them do not take into account possible room zoning. Consideration of turbulence intensity in the efficiency estimation was not found. In this work, we propose an approach to estimate the air exchange efficiency in different kind of rooms. It is a relation of minimum room demands and inlet air potentials. Additional definitions are introduced for the parameters and demands estimation. The mechanical energy of the air is used for the estimation, which includes the energy of averaged motion and turbulent pulsation. Special approach is offered for turbulence intensity computation for energy calculations. The example of efficiency estimation of air exchange in a museum room with constant air volume system of air conditioning is solved.  

Energy Saving Potentials of All Cold Air Distribution System With Stratified Air Conditioning in Large Space Building

2008 ◽  
Author(s):  
Wei Bing ◽  
Li Li ◽  
Yuefen Gao ◽  
Xianliang Yang
Keyword(s):  
Energy Consumption ◽  
Energy Saving ◽  
Air Conditioning ◽  
Distribution Systems ◽  
Future Application ◽  
Air Distribution ◽  
Outdoor Air ◽  
Large Space ◽  
Cold Air ◽  
Air System

So far the energy saving potentials in refrigeration and air conditioning systems are the focuses of researchers all over the world. The all cold air distribution systems are being widely used due to the advantages of saving building space, less energy consumption in some given conditions and less initial cost, mostly in the residential or office buildings. The stratified air conditioning technology is adopted mainly for large space buildings to reduce the system energy consumption, normally at conventional supply air temperature. In this paper, with an example of large space building, the energy consumptions of four all outdoor air systems are calculated and compared from the view of the total annual primary energy consumption. The detailed analysis shows that comparing the conventional all outdoor air system for the whole indoor space or that with stratified air conditioning technology, the all cold outdoor air system with stratified air conditioning has the energy saving potentials. It will be promoted in the future application of HVAC systems in large space buildings.

Controls and Diagnostics for Air Distribution Systems

2003 ◽  
Vol 125 (3) ◽  
pp. 310-317 ◽  
Author(s):  
John M. House ◽  
Kwangduk Douglas Lee ◽  
Leslie K. Norford
Keyword(s):  
High Frequency ◽  
Air Conditioning ◽  
Distribution Systems ◽  
Diagnostic Method ◽  
Air Distribution ◽  
The Past ◽  
Research Challenges ◽  
Operational Characteristics ◽  
New Findings ◽  
The Relationship

Fault detection and diagnostics applied to heating, ventilating, and air-conditioning (HVAC) equipment has been an active area of research over the past decade, with much of the work focusing on air distribution systems. Concurrent efforts have sought to improve the control of these systems. This paper discusses the relationship between controls and diagnostics for air distribution systems, provides an overview of the diagnostic literature for these systems, presents new findings from a diagnostic method that enables operational characteristics of individual HVAC components to be extracted from high-frequency measurements of whole-building power, and outlines research challenges that remain to be addressed.

Indoor Environment Numerical Simulation of All Cold Air Distribution System With Stratified Air Conditioning

2008 ◽  
Author(s):  
Wei Bing ◽  
Li Li ◽  
Jiang Lu ◽  
Zhang Wei
Keyword(s):  
Numerical Simulation ◽  
Distribution System ◽  
Air Conditioning ◽  
Distribution Systems ◽  
Dew Point ◽  
Air Distribution ◽  
Large Space ◽  
Cold Air ◽  
Point Temperature ◽  
Dew Point Temperature

At present all cold air distribution systems are being used widely due to their advantages of smaller ductwork, shorter floor-to-floor height and less energy consumption etc. They are mostly used in VAV (Variable Air Volume) systems or with the radiant panel systems in the office and residential buildings at the supply air dew point temperature of 6∼10°C, rarely used in large space buildings. The technology of stratified air conditioning is one of the energy saving technologies to large space buildings, which has been popularly used in the conventional air supply systems with the supply air dew point temperature of 11∼16°C. In this paper, the cold air distribution system and the stratified air conditioning technology in a large space building are combined to study. With the method of CFD, the indoor thermal environment of a large space workshop is simulated. The velocity and the temperature as well as the relative humidity fields under different air flow modes are presented, analyzed and compared. With the help of numerical simulation results, the optimal airflow mode is proposed, which show that the all cold air distribution with the stratified air conditioning is a good option for large space buildings. All these above will be good references to the application of cold air distribution system and the selection of the airflow mode in large space buildings.

A Study on Thermal Characteristics Affected by Air Distribution System Installed in Indoor Ice Rink Arena

2019 ◽  
Vol 27 (01) ◽  
pp. 1950007 ◽  
Author(s):  
Yong-Il Kwon
Keyword(s):  
Distribution System ◽  
Distribution Systems ◽  
Thermal Environment ◽  
Ventilation System ◽  
Thermal Characteristics ◽  
Heating System ◽  
Air Distribution ◽  
Winter Olympics ◽  
Ice Surface ◽  
The Republic

The Republic of Korea held the Winter Olympics in February 2018 and built several indoor ice rinks. Recently, the population of viewing and enjoying winter sports in indoor ice rink arenas is increasing and it is expected that the demand for building new indoor ice rink arenas will increase in the future. These indoor ice rinks generally should have an adequate dehumidification and heating system to provide optimal indoor air condition for users (spectators and athletes) under the required heat and humidity conditions. In addition, HVAC system designers should take steps to prevent fogging from condensation on the ice surface and to prevent condensation on the walls. This study was carried out to evaluate the formation of fog near the ice surface by using two air distribution systems applicable to the indoor ice rink arena. It was confirmed that the mixed ventilation method did not cause fog near ice surface, and that there is a great difference in the composition of the indoor thermal environment of the ice rink arena according to the type of ventilation system.

scholarly journals Influence of air distribution in modern large university lecture hall on thermal comfort

2019 ◽  
Vol 10 (1) ◽  
pp. 63-69
Author(s):  
Mária Budiaková
Keyword(s):  
Thermal Comfort ◽  
Distribution System ◽  
Air Conditioning ◽  
Distribution Systems ◽  
Winter Season ◽  
Point Of View ◽  
Air Distribution ◽  
Lecture Hall ◽  
Globe Temperature ◽  
Air Conditioning Systems

The paper is focused on the influence of air distribution in modern large university lecture hall on the thermal comfort. Providing the optimal parameters of the thermal comfort in the interiors of a university is immensely important for the students. Meeting these parameters is inevitable not only from physiological point of view but also to achieve the desirable students' performance. Parameters of the thermal comfort are also influenced by air distribution system in large university lecture hall. Correct position of supply air and extract air is very important. Experimental measurements of thermal comfort were carried out in the winter season in the large lecture hall of Vienna University of Economics and Business. The device Testo 480 was used for the measurements. Obtained values of air temperature, air relative humidity, air velocity, globe temperature, indexes PMV and PPD are presented in the charts. Modern air distribution system and air conditioning system of the large university lecture hall were evaluated on the basis of thermal comfort parameters. Conclusion of this paper states the principles of how to design modern air distribution systems and air conditioning systems in the new large university lecture halls.

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