46 research outputs found

    Performance evaluation of palm oil-based biodiesel combustion in an oil burner

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    This paper presents an experimental investigation of the combustion characteristics of palm methyl ester (PME), also known as palm oil-based biodiesel, in an oil burner system. The performance of conventional diesel fuel (CDF) and various percentages of diesel blended with palm oil-based biodiesel is also studied to evaluate their performance. The performance of the various fuels is evaluated based on the temperature profile of the combustor's wall and emissions, such as nitrogen oxides (NOx) and carbon monoxide (CO). The combustion experiments were conducted using three different oil burner nozzles (1.25, 1.50 and 1.75 USgal/h) under lean (equivalence ratio (φ) = 0.8), stoichiometric (φ = 1) and rich fuel (φ = 1.2) ratio conditions. The results show that the rate of emission formation decreases as the volume percent of palm biodiesel in a blend increases. PME combustion tests present a lower temperature inside the chamber compared to CDF combustion. High rates of NOx formation occur under lean mixture conditions with the presence of high nitrogen and sufficient temperature, whereas high CO occurs for rich mixtures with low oxygen presence

    Performance Evaluation of Palm Oil-Based Biodiesel Combustion in an Oil Burner

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    This paper presents an experimental investigation of the combustion characteristics of palm methyl ester (PME), also known as palm oil-based biodiesel, in an oil burner system. The performance of conventional diesel fuel (CDF) and various percentages of diesel blended with palm oil-based biodiesel is also studied to evaluate their performance. The performance of the various fuels is evaluated based on the temperature profile of the combustor’s wall and emissions, such as nitrogen oxides (NOx) and carbon monoxide (CO). The combustion experiments were conducted using three different oil burner nozzles (1.25, 1.50 and 1.75 USgal/h) under lean (equivalence ratio (Φ) = 0.8), stoichiometric (Φ = 1) and rich fuel (Φ = 1.2) ratio conditions. The results show that the rate of emission formation decreases as the volume percent of palm biodiesel in a blend increases. PME combustion tests present a lower temperature inside the chamber compared to CDF combustion. High rates of NOx formation occur under lean mixture conditions with the presence of high nitrogen and sufficient temperature, whereas high CO occurs for rich mixtures with low oxygen presence

    Thermo-economic optimization of RSORC (regenerative solar organic Rankine cycle) considering hourly analysis

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    In this paper, a RSORC (regenerative solar organic rankine cycle) is optimized. For this purpose, hourly analysis is considered and evaporator pressure, condenser pressure, refrigerant mass flow rate, number of solar panel (solar collector), storage capacity and regenerator effectiveness are selected as design parameters. Then RPGA (Real Parameter Genetic Algorithm) is used to find the maximum value of a new objective function named the RAB (relative annual benefit). The optimization is separately performed for three working fluids including R123, R245fa and isobutane. The optimization results reveal that the best studied working fluid is isobutane with 258810 /yearasrelativeannualbenefitandfollowbyR245faandR123with68173and64028/year as relative annual benefit and follow by R245fa and R123 with 68173 and 64028 /year as the RAB. The hourly analysis shows that in the optimum situation, a plant with isobutane as a working fluid produces higher electricity in the day hours while no electricity is produced in the night hours. Furthermore, a plant with isobutane needs the higher evaporator pressure, mass flow rate and number of solar panels with the lower condenser pressure, storage tank capacity and regenerator effectiveness compared with R245fa and R123. Finally the sensitivity analysis on simulation time step is performed and results are reported

    Energy analysis and multi-objective optimization of an internal combustion engine-based CHP system for heat recovery

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    A comprehensive thermodynamic study is conducted of a diesel based Combined Heat and Power (CHP) system, based on a diesel engine and an Organic Rankine Cycle (ORC). Present research covers both energy and exergy analyses along with a multi-objective optimization. In order to determine the irreversibilities in each component of the CHP system and assess the system performance, a complete parametric study is performed to investigate the effects of major design parameters and operating conditions on the system's performance. The main contribution of the current research study is to conduct both exergy and multi-objective optimization of a system using different working fluid for low-grade heat recovery. In order to conduct the evolutionary based optimization, two objective functions are considered in the optimization; namely the system exergy efficiency, and the total cost rate of the system, which is a combination of the cost associated with environmental impact and the purchase cost of each component. Therefore, in the optimization approach, the overall cycle exergy efficiency is maximized satisfying several constraints while the total cost rate of the system is minimized. To provide a better understanding of the system under study, the Pareto frontier is shown for multi-objective optimization and also an equation is derived to fit the optimized point. In addition, a closed form relationship between exergy efficiency and total cost rate is derived

    Assessment of new operational strategy in optimization of CCHP plant for different climates using evolutionary algorithms

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    Optimal design of combined cooling, heating and power (CCHP) generation systems is presented in this paper. The goal of this study is comparison of a new operational strategy named variable electric cooling ratio (VER) with constant electric cooling ratio (CER) for different climates including hot, cold and moderate. In VER strategy, the share of absorption and electrical chillers supply load could vary during a year while in CER strategy it is constant. The gas engine is selected as prime mover and Particle Swarm Optimization (PSO) method is used to select the optimum CCHP equipments by maximizing the Relative Annual Benefit (RAB) as a new objective function. Optimization Results show that VER strategy, provides more benefit in comparison with CER strategy in all the studied climates. VER strategy shows 12.71%, 5.84% and 10.92% growth in optimum value of RAB in comparison with CER in the case of hot, cold and moderate climates, respectively. Furthermore, the optimum results demonstrate that a gas engine with higher nominal capacity is needed in VER compared with CER strategy. Results show that the VER strategy is a good alternative for following the cooling load in the CCHP operational strategy since it gives a good increment in RAB. Finally the optimum results of PSO algorithm is compared with Genetic Algorithm and differences are reported

    Multi-objective particle swarm optimization of flat plate solar collector using constructal theory

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    In this study, the design and thermo-economic assessment of a flat plate solar collector has been explored by considering two scenarios. A conventional flat plate collector (FPC) is selected as the first scenario and multi-objective particle swarm optimization (MOPSO) algorithm has been applied to improve the thermal efficiency and total annual cost (TAC) simultaneously. In the second scenario, the constructal concept is implemented for the FPC by considering the same range of variations for the selected decision variables in the conventional FPC. Six design parameters including the system specifications are selected for the conventional FPC and for the constructal FPC in which is analyzed in two parts, hence twelve design parameters are selected for its optimization. The Pareto optimal front is obtained and compared for these two scenarios. In the thermal efficiencies higher than 0.54, the constructal Pareto optimal front is dominated over the results related to the conventional FPC

    An overview of renewable hydrogen production from thermochemical process of oil palm solid waste in Malaysia

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    Hydrogen is one of the most promising energy carriers for the future of the world due to its tremendous capability of pollution reduction. Hydrogen utilization is free of toxic gases formation as well as carbon dioxide (CO2) emission. Hydrogen production can be implemented using a wide variety of resources including fossil fuels, nuclear energy and renewable and sustainable energy (RSE). Amongst various RSE resources, biomass has great capacity to be employed for renewable hydrogen production. Hydrogen production from palm solid residue (PSR) via thermochemical process is a perfect candidate for waste-to-well strategy in palm oil mills in Malaysia. In this paper, various characteristics of hydrogen production from thermochemical process of PSR includes pyrolysis and gasification are reviewed. The annual oil palm fruits production in Malaysia is approximately 100 million tonnes which the solid waste of the fruits is capable to generate around 1.05 × 1010 kgH2 (1.26 EJ) via supercritical water gasification (SCWG) process. The ratio of energy output to energy input of SCWG process of PSR is about 6.56 which demonstrates the priority of SCWG to transform the energy of PSR into a high energy end product. The high moisture of PSR which is the most important barrier for its direct combustion, emerges as an advantage in thermochemical reactions and highly moisturized PSR (even more than 50%) is utilized directly in SCWG without application of any high cost drying process. Implementation of appropriate strategies could lead Malaysia to supply about 40% of its annual energy demand by hydrogen yield from SCWG of PSR. ©2015 Elsevier Ltd. All rights reserved

    Effects of duct burner on bottoming cycle in a combined cycle power plant

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    In this study, thermodynamic modeling and exergoeconomic assessment of a Combined Cycle Power Plant (CCPP) with a Duct Burner (DB) was performed. Obtaining an optimum condition for the performance of a CCPP, using a DB after gas turbine was investigated by various researchers. DB is installed between gas turbine cycle and Rankine cycle of a CCPP to connect the gas turbine outlet to the Heat Recovery Steam Generator (HRSG) in order to produce steam for bottoming cycle. To find the irreversibility effect in each component of the bottoming cycle, a comprehensive parametric study is performed. In this regard, the effect of DB fuel flow rate on cost efficiency and economic of the bottoming cycle are investigated. To obtain a reasonable result, all the design parameters are kept constant while the DB fuel flow rate is varied. The results indicate that by increasing DB fuel flow rate, the investment cost and the efficiency of CCPP are increased. T-S diagram reveals that by using a DB, higher pressures steam in heat recovery steam generator has higher temperature while the low pressure is decreased. In addition, the exergy of flow gases in heat recovery steam generator increases. So, the exergy efficiency of the whole cycle was increased to around 6 percent, while the cost of the plant reduced by one percent
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