Journal of Selected Topics in Energy

Potential of Energy Saving in The Furnaces

Hadie Mazlumi

Furnaces in refinery and petrochemical processes are major consumers of energy. The most important factors for the controlling the energy consumption of the furnace can be divided into three main groups The first group includes the potential savings without cost or low cost, such as adjusting air – fuel ratio in the burner and pressure control into the furnace, The second group includes the potential savings with medium cost such as insulating body, and the third group includes the potential savings with high investment such as heat recovery from the exhaust flue. In this paper, the thermal energy savings potential on the 4 fixed- furnaces in the Loabiran companies are investigated and calculated that savings potential of adjusting air – fuel ratio in the burner is 165,973,500 Rials in the year, controlling pressure inside the furnace 95,822,300 Rials in the year, body insulation 622,167,700 Rials and recycled flue gases 929,762,400 Rials in the year. Also Loabiran companies uses regenerator that is a periodic heat recovery system to preheat the incoming air. This will result in annual savings for the daily production of 20 tons of frit, are 3,577,000,000 Rials.

Existing Methods For The Simulation of Turbulent Drag Reduction By Using Microfibers

Amin Moosaie

Drag reduction in turbulent flows allows achieving of higher speeds and reducing energy consumption in the motion of submerged objects. An efficient technique for drag reduction uses dilute solutions of microfibers. In this paper, a review of available methods for the simulation of turbulent drag reduction by microfiber additives is presented. To compute the turbulent flow, the direct numerical simulation (DNS) technique is employed. The effect of the fibers on the flow is described by a non-Newtonian stress tensor, involving the distribution of fiber position and orientation. The fiber dynamics is governed by a Fokker-Planck equation. The computation involves a numerical solution of three-dimensional, time-dependent Navier-Stokes equations for the incompressible flow of a non-Newtonian fluid. In this article, various methods for solving the Fokker-Planck equation are reviewed.

Solar Still System To Distillation Saline Water: A Review

Ali Hosseini

Water shortage and energy crisis are two major challenges for human societies. Solar distillation devices the best solution for converting salt water to fresh water and saline domestic scale using free energy from the sun. This paper presents an overview of a variety of active and passive solar distillation devices for desalination of saline waters in remote rural areas with high solar radiation potential is done.

The Use of Cognitive Radio Networks Routing to Reduce Energy Consumption in Wireless Sensor Networks Dayjkstra Algorithm

Afsaneh Ebrahimi

The reduction of energy consumption on sensor nodes using cognitive radio network routing algorithm to help Dayjkstra, Can help a lot in increasing the life of nodes and improve the whole problem of the exchange of information without slowing down. Holes containing channel energy threshold is detected and checked by applying a range of secondary users assigned. From the simulation results of cognitive radio-based network routing algorithm can be seen Dayjkstra sensor nodes send data from the source node to the final node of their shortest and best route. Energy consumption by as much as 80 percent less sensor nodes with Dayjkstra algorithm of algorithms such as LEACH, DASC, EEUC that this factor is an increase in the lifetime of nodes in the network.

Thermal Management of Lithium-Ion Batteries in Automotive Electrical

Gholamreza Karimi

Because of increasing demand on new reliable power source for hybrid electric vehicles, lithium-ion (Li-ion) batteries have received much attention in the last decade. Problem free Li-ion batteries are already in use for low power demand applications such as cell phone and laptop battery packs, however; for high power applications such as in automotive propulsion drives, there are serious issues which need to be addressed. Among various issues that high power application lithium-ion (Li-ion) batteries are encountered, thermal issues have received more attention because of their potential to degrade battery performance. In this work, a lumped capacitance heat transfer model is developed in conjunction with a flow network approach to study performance of a commercial-size Lithium-ion battery pack, under various design and operating conditions of a thermal management system. Air, silicon oil and water are chosen as cooling media in the battery pack. Different flow configurations are considered and temperature dispersion, cell-averaged voltage and resistance distributions, and parasitic losses due to the fan/pump power demand are calculated. It is found that application of a coolant with an appropriate viscosity and heat capacity, such as water, in conjunction with a Y-type flow configuration will result in uniform temperature and voltage distributions in the battery pack while keeping the power requirement at low, acceptable levels.

Flare Gas Recovery In A Gas Refinery

Vahab Kazerouni

Considering the significant waste of gas in the oil and gas industry flares, it is highly desired to recover the gas in the industrial processes. Gas recovery reduces the energy consumption as well as the negative environmental impacts. In this study, different flare gas recovery methods are presented from exergy perspectives. Exergy analysis based on the second law overcomes the limitations of the energy-based analysis and offers a much more meaningful evaluation by indicating the association of irreversibilities. Analytical results indicate that simultaneous generation of power and heat by flare gases is the most effective method and can decrease the exergy destruction and fuel gas consumption of the cycle by 77.58 MW and 5793 kg/hr, respectively. When there is no demand for power, recycling the flare gases to process units and steam generating by the turbine exhaust gases can decrease fuel gas consumption of the cycle by 5605 kg/hr. It is also observed that pressurizing and recycling the gas for utility consumption can decrease the exergy destruction and fuel gas consumption of the cycle by 28 MW and 2100 kg/hr, respectively.