جستجوی مقالات مرتبط با کلیدواژه « ساختمان » در نشریات گروه « مکانیک »

After the era of the Industrial Revolution and the emergence of the modern age, many environmental hazards have been appeared. All of intellectual developments led humans to interact more with nature and the environment. The emergence of eco-technical, sustainable and green approaches were as a result of these changes and tried to establish more communication between the artificial environment and the natural environment. Among these, the field of architecture and construction has great importance due to the extent of the impact on the environment. In this regard, and in the field of architecture, many efforts were made in different countries of the world, such as the United States, the United Kingdom, etc. Therefore sustainable Assessment systems were designed and used to better control the construction process. In Japan, the CASBEE system is designed for this purpose. This article tries to study the structural features of CASBEE system as one of the most advanced systems for Assessing sustainable buildings with a descriptive-analytical approach with emphasis on studies. The CASBEE Assessment System technically and accurately calculates the environmental assessment of a building and its effects on its surroundings. While it has paid less attention to the social and economic aspects of sustainable development.

Wheat straw is one of the wastes produced in agricultural section that is burned in the farmlands entering huge greenhouse gases into the atmosphere. The aim of this study is to evaluate thermal energy loss from external walls of a building constructed using fired clay hollow bricks filled with compacted wheat straw. Hence, fired clay hollow bricks compared to those filled with compacted wheat straw (having a density of 0.156 g cm-3) were used to build up the walls of an experimental container model outdoor and thermal energy loss throughout the walls of it were evaluated. Comparison of thermal properties of the constructed walls using non insulated fired clay hollow bricks or insulated with compacted wheat straw including: thermal conductivity, heat flow rate and heat transfer coefficient showed decreasing from 0.2 to 0.04 W m-1 ºC-1, 18.36 to 6.98 W m-2 and 1.7 to 0.41 W m-2 °C-1, respectively, for insulated walls. The results revealed a decreased thermal energy loss between 72 to 81 percent from walls of the building constructed once compacted wheat straw with the compaction degree applied.

In this research, energy analysis of a cogeneration cooling and heating systems using solar energy for an office building for two various climates, namely Tabriz and Zahedan was presented. For this purpose, first, on office building measuring 112.7m2 was simulated in Hap4.9 software and required cooling and heating demand was calculated throughout a year. Afterwards, in order to meet the building energy requirement in the aforementioned regions, heating and cooling performance of an experimental apparatus, located in Niroo Research Institute in Tehran, was investigated with regarded alterations. TRNSYS 16 software was applied to simulate the system and the annual outputs for the climates were presented to evaluate the system.

Open space in residential complexes is a context for the generation of social relations along with environmental performance. Thermal comfort and appropriate architectural features attract people to these spaces. Airflow is one of the most fundamental parameters of outdoor thermal comfort, which is influenced by various factors, including the geometry of buildings. The present study investigated the effect of geometric modifications of buildings on wind flow pattern around the blocks in a residential complex. The case study is a residential complex consisting of 9 midrise blocks. The geometric shape of the blocks was modified and simulated in three steps and the effect of these modifications on the outdoor wind performance was evaluated. The main research method was descriptive analytical method with numerical simulation strategy and analysis of the results was conducted by logical reasoning. The models were simulated in Ansys Airpak 3.0.16 and their results were presented in the form of quantitative outputs, graphic contours as well as several charts. The results of numerical simulations proved the effect of building geometry on the outdoor wind flow pattern around the buildings. The results indicated an increase of 13.83% and 6.76% in average and maximum outdoor air velocity under the influence of buildings geometry modification. Among the studied geometries, the T-shaped form with proper wind flow conduction improved wind behavior in inter-block and inter-row domains. However, L-shaped forms (M3 model) significantly reduced the flow velocity in the inter-block areas by blocking the wind flow.

The purpose of this research is to design energy storage tanks using phase change material (PCM) in air conditioning system that PCM is part of the heat pump system and is connected directly to the air conditioner. From simulation and modeling methods through coding in software, parametric analysis, as well as introduction and suggestions for use a suitable PCM to store and reduce energy consumption in the building and check the performance of the heat exchanger in the latent heat storage using phase change materials is effective, are discussed. In this paper, first the thermal and refrigeration loads calculated using Carrier software and in the following, the cooling and heating process is simulated. Finally, from the phase change material in different modes used for energy storage in cooling and heating processes and is simulated in EES software. After modeling analysis with a minimum temperature of -5°C and maximum temperature 38°C considered and in different situations, the most suitable option for PCM tank mode in the heating process at the inlet temperature 35°C using 20 pipes in each row and PCM tank mode in the cooling process at the inlet temperature 10°C and selected using 22 tubes in each row.

The purpose of this research is to study the amount of energy consumed by the residential building and attempts to optimize it. In this work, the heating and cooling load of a residential tower in a hot and dry climate in Tehran has been calculated by Carrier software. To optimize energy consumption, changes in the material and color of the exterior walls and the change of the window's type and also the examination of the presence of shades to reduce the heat transfer coefficient were made. Results indicate that the change in the type of window will reduce the thermal and cooling load significantly. By replacing the single-layer window with the double-layer reflex one, the thermal load required to provide comfort conditions in the building in the winter is reduced by about 40%. The shading on the windows and also the change in the color of the external walls have each about 3 percentages reducing effect on the thermal and cooling load of the building, that is of less importance in comparison with the effect of windows type. Also choosing optimized materials for external walls leads to about 9 % load reduction in the winter and 6% in the summer. Finally, by calculating optimization process cost and also the cost of consuming energy for the building heating and cooling, the Break-even point and the return cost time regarding to the changes in the material of the window and the exterior wall were investigated. In the best situation the return cost time is about 3 years.

In the light of importance of sustainabile development, global warming as well as mortality of Fossil fuel correspondingly using of solar energy be more and more important. Photovoltaiv panel is an application of solar energy resource. A weakness of Photovoltaic panel is efficiency reduction caused by temperature increase. The efficiency of photovoltaic panel decreases by approximately 0.5% per Kelvin. There are different methods to PV thermal regulation, which the use of Phase change material is more important one. Organic or inorganic compounds that are capable of absorbing and storing large amounts of heat energy are called phase-change materials. Due to the high efficiency and high capicity of phase-change materials in energy storage systems, the use of these materials in recent years has attracted many developed countries. Accordingly, this paper reviewd studies about using PCMs for PV thermal regulation. Considering to the considerable enhancement of the PV performance via application the PCM, the PCMs can be a appropriate solution for the PV performance enhancement.

In today’s world too much energy is consumed to provide comfort conditions inside the buildings and this makes it necessary to estimate the energy consumption and recommend appropriate strategy to reduce it. One way of calculating the amount of energy consumption for providing comfort conditions is to employ simulated programs such as EnergyPlus and DesignBuilder. In this paper one authentic case study has been chosen and by applying DesignBuilder program, the amount of energy consumption for its cooling condition on 1st of July in three different cities based on two different strategies has been simulated and their effects on electric energy consumption have been compared. The first strategy is to employ the equation of estimating heat transfer via solar radiation and using overhang shades (6 different thicknesses) to reduce the area of the building exposed to solar radiation and reducing the heat gained from it. The second one is to apply the equations of Fourier's law in which the amount of reduction in heat transferred to the building by utilizing heat insulations in 5 different thicknesses is calculated. The results showed that the second strategy has much more superiority over the first one considering in Ahvaz and Tehran cities, but for Tabriz, the difference between two strategies is less. Furthermore the results obtained in Ahvaz showed that our conception of reducing the energy consumption by employing overhang shades is not always right. And employing heat insulation even by the thickness of one centimeter is more effective.

Present paper introduces a novel floor heating system which provides its heat by the Sun. This integrated system incorporates the advantages of both floor heating and free energy supply simultaneously. It is examined for a special building under different climate conditions. Based on the obtained results for very cold climate conditions the new system’s performance is significantly low. This is mainly due to the working fluid’s high temperature limit which causes the supporting solar system to be too much bigger than the normal one which is sufficient to heat up the building. The most significant advantages of the proposed design is for moderate climate conditions where the inlet temperature limit does not impose an extra area and, hence, cost for the solar system. For this condition the integrated system has superior advantages to the traditional ones.

Today, meeting increased power demand and solving the integration problems of fossil energy sources do not seem to be possible with today’s power grid infrastructure. As well as environmental pollution due to non-renewable energy is increased, so the best way to reduce the transmission and distribution losses and environmental pollution is that each building is supplied by its own unique renewable energy sources. This paper investigate the various aspects of building energy management and control systems of home appliances and electrical energy and review a smart building with renewable energy sources and energy storage systems. The effect of use of smart building management systems with renewable energy is studied. In fact, in this study, the method of load shifting has been used to smooth the load profile. One goal of this paper is to minimize dependence on the power grid during peak hours of electricity consumption and maximize the use of renewable resources. In order to overcome these problems and saving money, a new method of energy management has been proposed for smart building with renewable sources using load shifting. The results show 28% saving on the cost of electricity using proposed energy management system in smart building with renewable energy.

In this article, indicators of annual energy intensity 13 residential complexes with different characteristics were evaluated and compared. These features include the type of facade, heating and cooling systems, windows, and separate or shared type gas meters are units available in the complex. Introducing selected complexes, specifications hull, heating and cooling systems as well as the energy used in the study and analysis of energy flows in the complex have been discussed. The data processing methodology for calculating the energy consumption rate index have been studied conglomerate. The indices are calculated energy intensity of buildings and structures with different properties in terms of energy intensity compared. Compare energy intensity indicators show that the use of new energy Mtalh like metal siding board (decorative panels) instead facade, windows UPVC windows instead of metal, instead of single-wall and double glass instead of heaters and boilers as well as the use of semi-centralized heating systems or room in the building's energy intensity has considerably decreased. Also, instead of using a separate gas meter gas meter joint, by influencing the behavior of the occupants of the building and create a financial incentive to reduce energy use saves natural gas consumption and decreasing energy intensity building.

Energy consumption tendency in buildings and to find out the methods to manage and optimize it as audit or energy management methods are considered nowadays. Energy audit in every building is influenced by academic studies, experience and acquainting with new technologies of energy conservation. Renewable energies can play an important role in this way. Phase change materials (PCMs) are new substances with high heat of fusion. They absorb energy as latent heat until transformation in their phase. When the absorbed heat is needed, heat is extracted and material change to the primary condition. PCMs are very effective because they can be used in a variety of temperatures in cooling and heating. During the summer season, the benefits are a decrease in overall energy consumption and a time shift in peak load to off-peak hours that can decrease energy consumption cost. So, in this paper the role of PCMs in energy consumption management is considered.

Solar energy can be utilized through different types of passive and active solar systems. One of the passive systems is the Greenhouse that provides different functions. In this research, heating performance of Greenhouse in cold climate is simulated, investigated, and analyzed by means of computer software. The results of this research showed that Greenhouse, in comparison with Direct Gain glazing system, decreases building heating load, despite the diminution of the direct radiation gains. In Ardebil, the optimal building orientation, in order to get the maximum solar gain and the minimum load in the heating period, is obtained in south west and west direction of the facade. The maximum heat loss and minimum solar gain occur through the north side of the building, which is considered as the most inappropriate facade direction for the Greenhouse system.

Abstract- The correct selection of typical meteorological year is an important factor for accurate building energy simulation. In this study, the Sandia method has been applied to analyze the measured weather data of a 14-year period (1992–2005) in Tehran and to select the proper data for the typical meteorological year. Also, typical meteorological year has been generated by using the Meteonorm and Weathergenrator softwares. Then the results of the Sandia method and the two mentioned softwares have been compared with long term average measured data for main parameters in the weather data file. It was found that, the results of the Sandia method has good agreement with the long term average measured data but the created TMY data by the Weathergenrator and Meteonorm softwares have not good agreement with the long term average measured data.