فهرست مطالب

Energy Equipment and Systems - Volume:5 Issue:4, 2018
  • Volume:5 Issue:4, 2018
  • تاریخ انتشار: 1396/10/23
  • تعداد عناوین: 10
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  • Hassan Hajabdollahi *, Alireza Esmaieli Pages 325-339
    A regenerative organic Rankine cycle (RORC) is modeled and optimized for the use of waste heat recovery from a prime mover (PM). Three PMs including, a diesel engine, a gas engine, and a microturbine are selected in this study. Four refrigerants including isobutane, R123, R134a, and R245fa are selected. The nominal capacity of the PM, PM operating partial load, turbine inlet pressure, condenser pressure, refrigerant mass flow rate, pump efficiency, turbine efficiency, and regenerator effectiveness are considered as the decision variables. Then, the Genetic Algorithm is applied to maximize the thermal efficiency and minimize the total annual cost (TAC), simultaneously. The optimum results demonstrate that the best working fluid and the PM are, respectively, R123 and the diesel engine, which have a thermal efficiency of 0.50 and a TAC of $170,276/year. The optimum results are compared with each of the other studied cases. For example, the optimum result in the case of a diesel engine working with R123 shows a 2% and 2.52% improvement in the thermal efficiency and the TAC, respectively, in comparison to the case of a gas engine working with R123. Furthermore, a 26% and an 18.38% improvement in the thermal efficiency and the TAC are found when the best-studied cycle is compared with a microturbine and R123.
    Keywords: Regenerative Organic Rankine Cycle, Prime Mover, Total Annual Cost, Thermal Efficiency, Working Fluid
  • Hadi Ghaebi *, Mehdi Bahadorinejad, Mohammad Hassan Saidi Pages 341-348
    Confined aquifers are formations surrounded by impermeable layers called cap rocks and bed rocks. These aquifers are suitable for the seasonal storage of thermal energy.
    A confined aquifer was designed to meet the cooling and heating energy needs of a residential building complex located in Tehran, Iran. The annual cooling and heating energy needs of the buildings were estimated to be 8.7 TJ and 1.9 TJ, respectively. Two different alternatives were analyzed for an aquifer thermal energy storage (ATES) system. These alternatives were: 1) using ATES for cooling alone, and 2) coupling ATES with a heat pump for both cooling and heating. The thermal annual energy recovery factor and the annual coefficient of performance (COP) of the system were determined. A COP of 10 was obtained when ATES was employed for cooling alone. When ATES was employed for cooling and heating (using a heat pump), a COP of 17 was obtained for the cooling mode, and 5 for the heating mode.
    Keywords: Aquifer, Energy Recovery, Heat Pump, Thermal Energy Storage
  • Abdorrahman Haeri * Pages 349-355
    ISO 50001: 2011 provides an integrated and systematic framework to plan, implement, operate, certify, and maintain energy management systems (EMSs). Evaluation of organizations in relation to meeting the standard requirements is performed by an auditing qualitative approach. In this research, a quantitative approach has been proposed and implemented to assess organizations and rank them based on the related capabilities of the EMS. Initially, ISO 50001 was accurately reviewed to extract requirements. Later, an analytical hierarchy process (AHP) was used to perform pair-wise comparison and to specify the importance factors of ISO 50001 requirements. A number of Iranian oil and gas plants were evaluated in accordance with the specified requirements of ISO 50001. The results of the evaluation were used to rank the considered plant in capabilities of the EMS. In addition, it was used to specify which areas of ISO 50001 need more attention in the considered plants. Finally, the improvement approaches were proposed to enable Iranian oil and gas plants to increase the effectiveness of the implemented EMS.
    Keywords: Energy Management System (EMS), ISO 50001: 2011, Requirements of EMS, Analytical Hierarchy Process (AHP), Improvement Approaches
  • Azin Keshtkarbanaeemoghadam, Mohammad Hadi Kaboli *, Ali Dehghanbanadaki Pages 357-374
    Decreasing heating needed energy of building located in mountainous areas without any urban infrastructure of energy supply and services is one of the most important things to get thermal comfort. Accordingly, using building conditions based on different types of applicability and passive design strategies should be considered. Therefore, the objective of this study was to achieve the proper heating needed energy for proposing functional model as a mountainous shelter located in Iran. Two influence factors namely, number of people per area and different supportive space were considered. The analysis has been performed by Honeybee and Ladybug add-ons in Rhino/Grasshopper software. Material characteristic, zone load, location and climate data as sub-parameter were calculated using ASHRAE Standard 90.1-2010. The results indicated that regarding to time-use period of the shelter that is mostly in warm months, the highest performance of the space, based on minimum heating needed energy was attributed to the maximum size of supportive space by 608 m2 when the number of people was 0.26 per area. The reduction of heating needed energy was 17% in cold month and 23% in warm month.
    Keywords: Heating Needed Energy, Number of People Per Area, Supportive Space
  • Mohammadreza Shahnazari *, Leila Samandari-Masouleh, Saeed Emami Pages 375-387
    Combined cooling, heating, and power (CCHP) systems produce electricity, cooling, and heat due to their high efficiency and low emission. These systems have been widely applied in various building types, such as offices, hotels, hospitals and malls. In this paper, an economic and technical analysis to determine the size and operation of the required gas engine for specific electricity, cooling, and heating load curves during a year has been conducted for a building. To perform this task, an objective function net present value (NPV) was introduced and maximized by a genetic algorithm (GA). In addition, the results end up finding optimal capacities. Furthermore, a sensitivity analysis was necessary to show how the optimal solutions vary due to changes in some key parameters such as fuel price, buying electricity price, and selling electricity price. The results show that these parameters have an effect on the system’s performance.
    Keywords: Combined Cooling Heating, Power, Net Present Value, Internal Rate of Return, Primary Energy Saving, Genetic Algorithm
  • Md Emrad Hossain * Pages 389-399
    Due to numerous advantages of the doubly-fed induction generator (DFIG), the application of DFIG based wind generator (WG) is increasing very rapidly. However, the transient stability is one of the major concerns of the DFIG based wind generator. Therefore to accomplish this goal, in this paper, an existing non-linear controller based new inductive bridge type fault current limiter (NC-NIBFCL) is proposed to augment the transient stability of the DFIG based wind farm (WF), and its performance is compared with the existing series dynamic braking resistor (SDBR). In this work all simulations were executed in Matlab/Simulink software and in simulation, a temporary three-line-to-line (3LL) fault, and double-line-to-line (2LL) faults were applied in the DFIG based tested model system to examine the transient stability improvement performance of the proposed NC-NIBFCL. After simulation results, it is proved that the proposed method can improve the transient stability of DFIG based WF and performed well compared to SDBR.
    Keywords: Doubly-Fed Induction Generators (DFIG), Non-Linear Controller New Inductive Bridge Type Fault Current Limiter (NC-NIBFCL), Series Dynamic Braking Resistor (SDBR), Wind Generator (WG), Wind Farm (WF)
  • Hassan Moradi Cheshmehbeigi *, Farzad Fathinia Pages 401-409
    The Electromagnetic Aircraft Launch System (EMALS) is being developed utilizing electrical and electronic technologies. EMALS is emerging in order to replace the existing steam catapult on naval carriers. Recently, the double-sided linear launcher has drawn increasing attention of researchers. This paper presents the design and analysis of the Linear Hybrid Reluctance Motor (LHRM). This new motor is characterized by a stator, formed by a combination of independent magnetic structures. Each magnetic structure is composed of an electromagnet—the magnetic core with one or several coils wound around it and associated with a permanent magnet, disposed between their poles. The rotor has the same configuration of a switched reluctance motor (SRM) without any coil, magnets or squirrel cage. In order to improve the thrust of LHRM, the structural characteristics and magnetic field are analyzed. According to the initial design, the Finite Element Analysis (FEA) is presented to obtain the magnetic cogging force and thrust force. Moreover, the effects of the parameters on the thrust and thrust ripple waveforms are analyzed using FEA.
    Keywords: EMALS, LHRM, Double-Sided, FEA, Magnetic Field Analysis
  • Saeed Firouzi *, Mohammad Bagherzadeh, Amir Hossein Bazyar Pages 411-418
    The aim of this research was to study the energy flow and the modelling of energy use in broiler production in the Guilan Province of Iran. The data were gathered through interview with 25 broiler farm managers out of a total of 146 broiler producers in Rasht, the center of Guilan Province, Iran. The effect of broiler farm size at three levels—small (˂20,000 birds), medium (20,000–30,000 birds), and large (˃30,000 birds)–was evaluated, based on the energy use indices. The Cobb-Douglas model and sensitivity analysis were used to investigate the effects of energy inputs on poultry production. The results showed that the total energy input and energy ratio were 2,605.54 Mcal (1000 birds)-1 and 0.234, respectively. Diesel fuel and feed were ranked the first and second energy inputs for broiler production with the shares of 43.92% and 36.68%, respectively, of the total energy input. The shares of renewable and non-renewable energy forms in broiler production were determined to be 37.33% and 62.67% of the total energy input, respectively. The energy ratios of small, medium, and large farms were computed as 0.232, 0.225, and 0.250, respectively. Consequently, the large-sized farms were more energy efficient than the small and medium-sized ones. Results of the Cobb-Douglas model showed that the impacts of energy inputs of labor, chick, diesel fuel, machinery, disinfectants, and medicines on broiler performance were positive, while the impacts of electricity and feed were negative.
    Keywords: Agriculture, Energy Analysis, Modeling, Poultry
  • Somayyeh Sadri, Ramin Haghighi Khoshkhoo *, Mohammad Ameri Pages 419-430
    The mathematical model to predict the performance and the exergetic efficiency in a multi-effect desalination system with thermal vapor compression (MED-TVC system) has been presented. The energy and the concentration conservation law were developed for each effect, considering the boiling point elevation and the various thermodynamic losses by developing the mathematical models. These analyses led to the determination of the thermodynamic properties at different points and to the gain output ratio (GOR) values. Then, a heat transfer equation was developed in each effect and the required heat transfer areas were determined. Finally, irreversibility analysis was performed, from which the exergy destruction (considering chemical and physical exergy) and the exergetic efficiency were calculated. To obtain the optimum point of a system, multi-objective optimization was used. Determination of the best trade-off between GOR and heat transfer area was the final goal of this optimization. The optimum design led to a selected system with the lowest heat transfer area (and related cost) and the highest GOR.
    Keywords: Desalination, Exergy Analysis, Heat Transfer Analysis, Multi-Effect Distillation, Optimization
  • Morteza Bayareh * Pages 431-437
    Three-dimensional numerical simulations are performed to investigate the effects of pressure drop across the turbine and solar radiance on the performance of a solar chimney power plant (SCPP). The SCPP system expected to provide electric power to a city is located in southern region of Iran (city of Lamerd, Fars province). Its dimensions are similar to the Manzanares prototype (built in Spain, 1970s). The results demonstrated that the SCPP can provide up to 40–200 KW of power, depending on the season. It was found that the turbine pressure drop and the solar radiation had significant effects on the first and second law efficiencies.
    Keywords: Solar Chimney Power Plant, Turbine Pressure Drop, Performance Analysis, South of Iran, Output Power