Yazar "Hepbasli, Arif" seçeneğine göre listele

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    Advanced exergoeconomic evaluation of a heat pump food dryer
    (Academic Press Inc Elsevier Science, 2014) Erbay, Zafer; Hepbasli, Arif
    In this study, the results of conventional and advanced exergoeconomic analyses of the performance of a pilot scale air-source heat pump food dryer were compared for the first time. The contributions of the components of the drying system to the exergetic cost effectiveness of the dryer were evaluated, and the effects of changing the inlet drying temperature were determined. The most important system component was determined to be the heat recovery unit, followed by the condenser with respect to the reducing potentials for the total costs of the overall system. Decreasing temperature caused an increase in the cost performance of drying. The modification of the system components for improving the efficiency of the system can be effectively determined through advanced exergoeconomic approach by stating the realistic potential improvements and the priorities in the system. (c) 2014 IAgrE. Published by Elsevier Ltd. All rights reserved.
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    Application of conventional and advanced exergy analyses to evaluate the performance of a ground-source heat pump (GSHP) dryer used in food drying
    (Pergamon-Elsevier Science Ltd, 2014) Erbay, Zafer; Hepbasli, Arif
    Inefficiencies in an energy system can be quantitatively determined through conventional exergy analysis while sources of the irreversibilities and real improvement potential can be deducted using a relatively new method named as advanced exergy analysis. For the first time, an advanced exergy analysis is applied to a ground-source heat pump (GSHP) drying system used in food drying for evaluating its performance along with each component in this study. The results indicate that the most important system component is the condenser due to the design standpoint. The inefficiencies within the compressor could particularly be improved by structural improvements of the whole system and the remaining system components. Furthermore, the inefficiencies of other system components except for the condenser and the evaporator are mainly affected by the internal operating condition. Both the equipment design and system components' interactions of the condenser and the evaporator have a significant effect on their inefficiencies. The conventional and modified (advanced) exergy efficiency values are calculated to be 77.05% and 93.5%, respectively. (C) 2013 Elsevier Ltd. All rights reserved.
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    Assessment of cost sources and improvement potentials of a ground-source heat pump food drying system through advanced exergoeconomic analysis method
    (Pergamon-Elsevier Science Ltd, 2017) Erbay, Zafer; Hepbasli, Arif
    Advanced exergoeconomic analysis, the so-called new exergetic approach combined with the economic analysis, is applied to a ground-source heap pump (GSHP) drying system in this study. The thermodynamic inefficiencies and cost performance of the system components are evaluated in parts. Moreover, the results of the advanced exergoeconomic analysis are compared to those of the conventional exergoeconomic analysis. The results show that total costs in the overall system are 4.008 $/h whereas 2.569 $/h of the total costs are avoidable. The avoidable investment costs are significantly lower than avoidable destruction costs. Advanced exergoeconomic analysis indicates that the most important system components are the drying duct and the condenser with respect to reducing the costs. It is possible to reduce 34.6% of the total costs by developing improvement strategies focused on the drying duct and the condenser. It may be concluded that the conventional exergoeconomic analysis is an effective approach to specify the components, in which costs are accumulated while the advanced exergoeconomic approach is essential to determine the cost sources and to develop cost effective improving strategies. (C) 2017 Elsevier Ltd. All rights reserved.
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    Enhanced exergetic analysis of an olive oil refining plant: evaluation of the first and second level of exergy destructions
    (Inderscience Enterprises Ltd, 2019) Bozoglan, Elif; Erbay, Zafer; Hepbasli, Arif; Gunerhan, Huseyin
    Enhanced exergy analysis is built up as a novel modality to specify the origins of irreversibilities and to concentrate substantial improvement potential of components. The scope of this paper is to apply the enhanced exergy analysis to an olive oil refinery plant operated in Izmir, Turkey, that is conducted for the first time to agree the first level (endogenous/exogenous) and the second level (combination of the endogenous/exogenous and unavoidable/avoidable parts studied before) of destructions for exposing substantial efficiencies. Results showed that the components in the plant mostly have endogenous exergy destructions. Besides, the distillation unit has the highest endogenous exergy destruction value of 150.9 kW as the avoidable and unavoidable endogenous sections are 76.85 and 74.08 kW, respectively. Furthermore, the shell and tube economiser has the highest modified (enhanced) exergetic efficiency of 99.9% while the modified performances of plate-heat exchanger and pump (VII) are calculated as 73% and 71.24%, respectively.
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    Exergoeconomic evaluation of a ground-source heat pump food dryer at varying dead state temperatures
    (Elsevier Sci Ltd, 2017) Erbay, Zafer; Hepbasli, Arif
    This study deals with exergoeconomic analysis of a ground-source heat pump food dryer through the specific exergy costing method for the first time. Moreover, variations of the exergetic and exergoeconomic performance parameters with dead state temperatures are also investigated and discussed with the literature results. The results show that the condenser is the most important system component from the efficiency improvement point of view with a total cost rate of 1.347 $/h and exergoeconomic factor of 0.029. The main part of the exergy costs accumulated in the condenser is generated during the process and the optimization of the operating conditions of the condenser has a major importance in improving the overall system performance. Furthermore, heat exchangers in the ground-source heat pump system are influenced from the alteration of the dead state temperature. Increase in the dead state temperature generally leads to decrease in the exergetic efficiencies of system components. The total costs occurred in the evaporator significantly increase with the rise in the dead state temperature. Authors expect that the results of the present study can provide some guidelines for the designs of the ground-source heat pump systems. (C) 2016 Elsevier Ltd. All rights reserved.
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    Splitting the exergy destructions of an olive oil refining plant into avoidable and unavoidable parts based on actual operational data
    (Inderscience Enterprises Ltd, 2016) Bozoglan, Elif; Erbay, Zafer; Hepbasli, Arif; Gunerhan, Huseyin
    This study focused on assessing the performance of an olive oil refinery plant (with an oil capacity of 5595 kg/h) located in Izmir, Turkey. The analysis was performed with the use of actual operational data of the system components while an advanced exergy analysis method was used. By this way, unavoidable and avoidable destructions of olive oil refinery plant components were obtained. The results indicated that the greater part of the exergy destructions detected in the system were avoidable and could be minimised by improvements in the design. The highest exergy destruction rate (217.96 kW) was determined owing to the distillation unit of the system with a markedly high unavoidable exergy destruction ratio of 50.92%. In addition, the efficiencies of the components in the plant varied from 5.67% to 90.7% while their corresponding modified exergetic efficiencies were in the range of 8.74% and 92.48%.