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Gas conditioning towers (GCTs) or cooling towers have broad industrial applicability, especially in the cement industry. Most cement factories deal with the same problems faced by other factories. However, the solutions to these problems are barely internationally published and have not received much attention, meaning a lot of time and money is spent on researching previous solutions. Iran is among the top ten cement manufacturing countries in the world. Therefore, many of these problems have occurred in Iranian cement factories. The purpose of this paper is to provide a review of studies in this field over the last couple of decades, with a particular focus on advances in Iran. The most important findings in the literature are summarised in order to suggest the best possible solutions for improving the performance and lifetime of GCTs and decreasing common problems such as dust build-up and wet bottom. Numerical methods for modelling different aspects of GCTs are reviewed. The results can be used to reduce water and energy consumption, air pollution and the repair and maintenance costs of cement factories. [ABSTRACT FROM AUTHOR]

Population growth and building mechanical devices to achieve thermal comfort have increased energy consumption. The hot and humid climates account for high energy consumption in the building sector. Meanwhile, for centuries, vernacular houses in this climate complied with their environment. This paper examined the vernacular architectural elements of two southern cities of Iran with hot and humid climate conditions on the coast of Makran. However, a comprehensive study of these elements and their role in indoor air quality and the creation of thermal comfort has yet to be discovered. This study incorporated climatic information into a computational fluid dynamics simulation to analyze vernacular architectural elements in the study area. By combining the architectural elements of Bushehr and Chabahar vernacular houses, 13 building models were created, with a component of each element to be investigated. Results showed which elements boost the incoming flow and which models become more effective in developing an enhanced model in terms of ventilation. However, a wind exchanger (Dudkesh) works better than a wind catcher and Taremeh in terms of airflow velocity across the buildings. Additionally, models could establish about 38% comfortable hours during the year with natural ventilation and sun shading in Bushehr. Before HVAC systems and the emergence of technology, people in different cities discovered different ways of ventilating and cooling their homes. Among these strategies was the use of architectural elements in their vernacular dwellings. A tall wind catcher or a central courtyard could change the air condition and was not solely intended for aesthetic purposes. Many of Iran's ancient cities have architectural elements unique to their old vernacular architecture. According to their location, these elements differed in size and shape based on the climate. Chabahar and Bushehr are located near the Persian Gulf and Oman Sea in southern Iran. Although both are located in hot and humid areas, the architectural elements used in their vernacular architecture differ. In this study, we tried to examine their function individually or by combining them to see whether they could work if installed in another environment. [ABSTRACT FROM AUTHOR]

Energy demand keeps growing all over the world and is contributing to climate change. So, fossil fuels must be replaced by renewable energies. Solar energy is the most accessible energy in Iran as well as in many other countries. Parabolic solar collectors appear to be a very promising technology in solar energy absorption. Meanwhile, nano-fluids are known to improve the heat transfer capabilities in comparison with ordinary pure fluids. In this work, an experimental study was applied to solar collectors using water/Al2O3 nano-fluid located in a renewable energy site of Islamic Azad university of Khomenishahr branch followed by numerical simulations. Experimental tests were conducted for 2, 3, and 4 L·min−1 flow rates with pure water and 0.1 %, 0.2 %, and 0.3 % volume fraction of nanoparticles, respectively, with the results validating the numerical simulations. The results revealed that reductions in flow rate and elevations in volume fraction led to increased outlet temperature of solar collector, inlet and outlet temperature difference in collector, tank and radiator, and improved solar collector efficiency. Also, heat transfer coefficient rose with augmenting the flow rate and volume fraction. [ABSTRACT FROM AUTHOR]

Abstract: Thermal analysis of a novel integrated system of ground heat exchanger and indirect evaporative cooler is performed in the summer conditions of Tehran, the capital city of Iran. A ground-coupled circuit pre-cools the entering air of an indirect evaporative cooler. This circuit includes four vertical ground heat exchangers which are arrayed in a series configuration. In order to have an accurate prediction of the optimum performance of the ground-coupled circuit, a three-dimensional computational fluid dynamics simulation is run. The simulation results reveal that the combination of the ground-coupled circuit and the indirect evaporative cooler can easily provide comfort conditions. Based on the results, the cooling effectiveness of this hybrid system is more than unity and this novel hybrid system significantly decreases the air temperature below the ambient wet-bulb temperature. As a result, the proposed system can be used as a clean and efficient air conditioner. [Copyright &y& Elsevier]

The application of incinerators for the municipal solid waste (MSW) is growing due to the ability of such instruments to produce energy and, more specifically, reduce waste volume. In this paper, a numerical simulation of the combustion process with the help of the computational fluid dynamics (CFD) inside a portable (mobile) incinerator has been proposed. Such work is done to investigate the most critical parameters for a reliable design of a domestic portable incinerator, which is suitable for the Iranian food and waste culture. An old design of a simple incinerator has been used to apply the natural gas (NG), one of the available cheap fossil fuels in Iran. After that, the waste height, place of the primary burner, and the flow rate of the cooling air inside the incinerator, as the main parameters of the design, are investigated. A validation is also performed for the mesh quality test and the occurrence of the chemical reactions near the burner of the incinerator. Results proved that the numerical results have less than 5% error compared to the previous experimental and numerical approaches. In addition, results show that by moving the primary burner into the secondary chamber of the incinerator, the temperature and the heating ability of the incinerator could be affected dramatically. Moreover, it has been found that by increasing the flow rate of the cooling air inside the incinerator to some extent, the combustion process is improved and, on the other hand, by introducing more cooling air, the evacuation of the hazardous gases from the exhaust is also improved. [ABSTRACT FROM AUTHOR]