فصلنامه مهندسی و مدیریت انرژی
سال سوم شماره 2 (پیاپی 8، تابستان 1392)

Generation Expansion Planning (GEP) is a large-scale nonlinear optimization problem with stochastic behavior. Generation system planers tend to use many different methods to address the expansion problem and to determine optimum plans by minimizing the mathematical objective function subject to different constraints. This paper presents an Improved Genetic Algorithm (IGA) to solve (GEP) problem. This algorithm uses Capacity Outage Table (COT) method، Analytical Hierarchy Process (AHP)، Successive Forward and Backward method and a new approach to improve the GA. The expert engineers suggestions have important role in this algorithm.

Magnesium hydride is one of the hydrogen storage materials in solid state that is taken into consideration duo to its high storage capacity. This paper investigates the adsorption of magnesium and nickel catalyst combination in 473 K at 2. 0 and 3. 5 Mpa. A planetary ball mill was used in order to produce fine particles and to increase adsorption. A volumetric method (Sievert) was used for hydrogen storage analysis. XRD analysis was performed before and after hydrogenation in order to phase identification. SEM images were used for morphological characterization and particle size distribution. Higher pressure leads to increase of adsorption because it helps to influence of hydrogen. Finally Mg+10Ni compound showed the adsorption of 2. 04% and 3. 51% wt. hydrogen in pressure of 2. 0 and 3. 5 Mpa، respectively. The results showed that Ni is a good catalyst for hydrogen storage with accelerating hydrogen molecules dissociation and assisting to better milling.

At this analyis، the premixed co-flow flames propagation of the Organic Porous particles-cloud combustion is studied with considering uniform mixture of fuel and air. Because of size equality assumption of the porous particles، lycopodium particles at this research are assumed. This analysis framework is thermal-diffusion model with this assumption that the lewis number is unit and the strain rate is constant. Velocity profiles are intended as a function of x in the direction of flames propagation. The structure of the flame is presumed to be consist of a preheat vaporization zone، a reaction zone and a convection zone. The Zeldovich number، based on the gas-phase oxidation of the gaseous fuel is large and the heat loss is neglected. This analysis consists of the result for the effect of different porous on the flame temperature and flame location. The results is illustrating when porous increase، the accessible substance to yield a gaseous fuel is decreasing that will be cause to burning velocity decrease. Also، flame location go to low burning velocity zone and the solid fuel at flame location increase، that not vaporized. This is match to the governing physics and experimental results.

In this paper، in order to introduce manufacturing cost reduction methods، using a thermodynamic approach، the performance of cast iron rotary furnaces is analyzed. To do so، the furnace atmosphere is chosen as a control volume. Then، heat sources، heat sinks and heat loss mechanisms are recognized and the first law of thermodynamic is applied to the control volume. The analysis showed that radiation is the dominant heat transfer mechanism and a large portion of heat generated by fuel consumption is lost through hot gasses that leave the furnace and due to heat conduction from furnace drum. Consequently، more than 90 percent of input energy to the furnace is lost. The first method to reduce the fuel cost is to pre-heat the input air which can reduce the fuel consumption by 10%. The other method is to replace the conventional fuel of cast iron rotary furnace –Fuel Oil- with Natural Gas، which is very effective to reduce fuel cost because the price of natural gas is much lower than the price of fuel oil.

In this paper a comprehensive model is proposed to simulate combined cycle water and power process (CCWP) based on thermal desalination. In order to verify the performance of model، Al-Taweelah cogeneration plant in UAE is thermodynamically simulated by Thermoflex V. 19 and the results are compared with actual operating conditions. Considering shortcomings of mentioned unit، a cogeneration combined cycle is configured based on conventional power generation units in Iran. In this configuration، thermal desalination units utilize exhausting steam from a back pressure turbine as energy source. Desalination processes which are investigated in present study include Multi-Stage Flash (MSF) and Multi-Effect Distillation (MED). Results show that increasing the backpressure from 6 to 40 bars decreases the electrical efficiency of cogeneration unit from 21 to 41%، compared to a single-purpose unit. It also leads to increment of 32 to 67% in power generation cost، but results in 23% of fuel saving. The electric power consumption of MSF unit is very high، about 3. 3 times of that of MED. This fact implies that the production cost of MSF is 12. 5% more than that of MED، which remains almost constant at 0. 88 $/m3 by changing the backpressure.

In this study، a micro-CHP system using a gas internal combustion engine with a maximum power of 5 kW of thermal and electricity energy has been designed and constructed. This system can be supply the consumption of heat and electrical energy for single households. The results indicated that the efficiency of the system is increased about 70% as compared to single generation system. Using the MCHP system is more efficient and saving energy than the conventional heat and power generation.