نشریه انرژی ایران
سال سیزدهم شماره 1 (پیاپی 46، بهار 1389)

In the last three decades, the D-T mixture owing to its appropriate properties as the fuel of future fusion reactors, has dedicated most of the activities and research facilities to itself x. In the last three decades, most of the activities and research facilities have been dedicated to the D-T mixture owing to its appropriate properties as the fuel for future fusion reactors. However, the D-T reaction has a few difficulties too, the most significant of which is the production of a considerable amount of neutrons that take up a major part of the generated energy, which is practically lost, and moreover instigate severe destruction of the reactor’s construction materials and also biological and environmental hazards. Studies have been carried out to overcome problems to find fuels capable of replacing the D-T fuel cycle. Types of fuels, usable in nuclear fusion have been introduced in this paper and their properties and their potential future use studied. Reaching the necessary conditions for self-sustaining fusion by these fuels still requires many scientific and technical advances, but is not impossible. Results of the studies carried out show that the mixture of p-11B is the most suitable fuel to solve the mentioned problems and majority of the research activities are now concentrated on this fuel.

Expansion of city electric trains is one of the fundamental solutions considered to control the rise of fuel demand of vehicles, in urban journeys. This solution has been discussed in our country for the last thirty years and has already grown considerably. Another means of public transport in the country is fleet of elecrtic buses that was initially well-liked for environmental reasons (especially in Tehran), but did not really develop afterwards in the absebnce of appropriate infrastructure needed for building new lines. Having these two systems of public transport, it is necessary as for other sectors, to calculate the required demand of this sector and include this in the energy planning programme of the country. Demand forecasting based on final demand models, is one of the accepted forecasting methods, and different models such as MAED have been developed for this purpose. Alongside this, all required information have been collected from the subway and electric bus companies, and the corresponding organizations. After processing and necessary calculations, the required data of the MAED model have been produced. Using this model, the electrical energy demand of transport sector is thus predicted and is compared with aims established in the twenty year development plan manifesto.

Awareness of efficiency limitations of turbines helps us be able to optimize the design of wind and water power generation fields. Exact assessment of theoretical generating power of the turbine in free flow of the fluid is of great importance. This is because the growing tendency to increase production of power from wind and from water sources with zero altitude is of ever-increasing attention. These include great kinetic energy source from oceans movement and tidal energy and from rivers with no dams built. In this article, a forthright and solvable mathematical model for estimation of maximum efficiency of turbine in free flow is given. These results can be utilized for electricity generating hydro/water turbines, where building dams is impossible. This model is associated with a finite two dimensional plane with fairly low permeability in an incompressible flow; which is desirable for two dimensional blades but is less suitable for turbines with transverse three dimensional flows. The most interesting finding of our analysis is that for free flow; highest efficiency of flat blade is 30%. This result is in great opposition with the 60% value given by Betz, which has been adopted presently and for the last few decades. It has been shown that Betz’s above assessment is the consequence of ignoring the curvature of the fluid flow. Also, it has been proved that the three dimensional spiral turbine is much more efficient than two dimensional blade, at least for hydro applications.

Oil products storage, loading & distribution system forms the most essential part of oil products supply chain. The management of this system plays a critical role in the performance of the oil products supply chain. Due to widespread operations in oil depots, implementing scientific methods and optimization, instead of traditional ones, seems necessary in order to optimize the use of fuel storage depots’ resources and decrease system costs. In this study, a queue model of depot with successive services has been adopted to achieve quantitative results for the analysis of the depot performance. The designed simulation model has been implemented by using information data from the Northwest of Tehran oil depot. Then by using the SA metaheuristic method, it has been attempted to obtain the optimum combination of loading arms in the depot for achieving minimum waiting time for tanker trucks in the queue, before entering the depot. The obtained results have been compared with optimum results from the commercial OptQuest optimization simulation software, and are briefly presented.

This paper deals with modeling and optimization of under-floor heating by Pex pipes. For modeling, the calculation region is divided into two sections. First section is above the floor comprising room space and its walls. For this section, the Multizone model is used. In this model, the first section is considered as a Control Volume and its non-linear energy equations are solved by Newton-Raffson method. Second section is the floor and below comprising heating pipes, concrete and floor covering. This section is modeled by numerical method. Through combining the modeling of first and second sections; simulation of the total system is completed. For optimization of under floor heating system, a goal function has been defined. Pipe diameter, concrete thickness, type and thickness of floor covering, and hot water flow rate inside the pipes are considered as deciding variables (design parameters). In continuation, sensitivity of the goal function to variation of deciding variables is investigated. Finally, effects of atmospheric temperature changes and thermal insulation thickness of the building upon the design parameters are investigated.

City of Yazd is located on the yellow radiation belt and has a high potential as regards receiving solar energy. Estimated radiated solar energy is about 7787 MJ/m2 per year. The object / purpose of this paper is to present two methods for estimating the total solar radiation on a plane surface and comparing this with pyranometric (pyrometric √) measurements data (in this city) and determining the statistical error in this city. In the first method by obtaining the parameters including temperature, precipitation, as well as sunshine and radiation hours, from Meteorological organization (IRIMO) for the duration of 1982 till 2003 the regression equation of Radiation versus these parameters was derived. In the second method (Angstrom Model) by using the data of pyranometric (pyrometric) and sunshine hours in the same time duration and calculating the rest of the parameters the amount of Radiation was estimated. From investigation by statistical software SPSS, it was observed that the statistical errors in the first method were higher, and that statistic correlation exists between the independent variables considered; and also these parameters are interacted on each other, and that finally the only independent parameter is the sunshine hours. So for this purpose, when the amount of the radiation is not available, using the Angstrom equation “” is suggested for city of Yazd.

Considering the increasing demand for energy in the world, in the face of limited fossil fuel resources; the necessity of using renewable energies is revealed more than ever. An alternative suggestion to overcome the intermittence of the renewable energy sources like sun and wind is to develop hybrid energy systems, where it is possible to convert and store surplus electrical energy. These sources combined with energy storage would then provide a more reliable system, making them suitable for stand-alone applications independent of the network. In this study, we will present the results of techno-economic analysis of the hybrid photovoltaic/wind energy system with hydrogen storage, which is carried out by the HOMER simulation software; adopted to simulate and optimize the supply of power to the stand-alone building and lighting of East-West Boulevard and landscaping of Taleghan site.