Browsing by Author "Erbay, Zafer"

Now showing 1 - 9 of 9

Citation - WoS: 49
Citation - Scopus: 53
Advanced exergoeconomic evaluation of a heat pump food dryer
(ACADEMIC PRESS INC ELSEVIER SCIENCE, 2014) Zafer Erbay; Arif Hepbasli; Hepbasli, Arif; Erbay, Zafer
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.
Citation - WoS: 53
Citation - Scopus: 56
Advanced Exergy Analysis of a Heat Pump Drying System Used in Food Drying
(Taylor & Francis Inc, 2013) Zafer Erbay; A. Hepbasli; Hepbasli, Arif; Erbay, Zafer
Exergy analysis has been used as a powerful tool to study and optimize various types of energy systems. However the methodology of splitting the exergy destructions (the so-called advanced exergy analysis) allows for a further understanding of the exergy destruction values to improve the system efficiency. In this study advanced exergy analysis was applied to a pilot-scale heat pump drying system used in food drying for the first time to evaluate its performance at different drying temperatures. The results showed that inefficiencies within the compressor and condenser were mainly due to the internal operating conditions and the efficiencies in the evaporator and heat recovery system could be improved by structural improvements of the whole system and remaining system components. © 2013 Copyright Taylor and Francis Group LLC. © 2013 Elsevier B.V. All rights reserved.
Citation - WoS: 98
Citation - Scopus: 101
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) Zafer Erbay; A. Hepbasli; Hepbasli, Arif; Erbay, Zafer
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. © 2013 Elsevier Ltd. All rights reserved. © 2014 Elsevier B.V. All rights reserved.
Citation - WoS: 36
Citation - Scopus: 45
Assessment of cost sources and improvement potentials of a ground-source heat pump food drying system through advanced exergoeconomic analysis method
(Elsevier Ltd, 2017) Zafer Erbay; A. Hepbasli; Hepbasli, Arif; Erbay, Zafer
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. © 2018 Elsevier B.V. All rights reserved.
Citation - WoS: 1
Citation - Scopus: 1
Enhanced exergetic analysis of an olive oil refining plant: evaluation of the first and second level of exergy destructions
(INDERSCIENCE ENTERPRISES LTD, 2019) Elif Bozoglan; Zafer Erbay; Arif Hepbasli; Huseyin Gunerhan; Erbay, Zafer; Hepbasli, Arif; Bozoglan, Elif; 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.
Citation - WoS: 50
Citation - Scopus: 56
Exergoeconomic evaluation of a ground-source heat pump food dryer at varying dead state temperatures
(ELSEVIER SCI LTD, 2017) Zafer Erbay; Arif Hepbasli; Hepbasli, Arif; Erbay, Zafer
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.
Citation - Scopus: 36
Performance assessment and optimization of industrial pasta drying
(2013) Neslihan Colak Gunes; Zafer Erbay; A. Hepbasli; Colak, Neslihan; Hepbasli, Arif; Erbay, Zafer
Drying is a high-energy-intensive operation and an important step in the pasta production. In this study exergy analysis of a four-step drying system in a farfalle pasta production line using actual operational data obtained from a plant located in Izmir Turkey was performed. Exergy loss rates evaporation rates exergy efficiencies and improvement in potential rates for each dryer section were determined in this drying system. The exergy efficiency values varied between 0.25% and 5.27% from the predrying to the final drying section. The exergy efficiency value for the entire drying system was calculated to be 2.96% and the highest exergetic improvement in potential rate was 165.54kW for the first dryer section. Copyright © 2013 John Wiley & Sons Ltd. A four-step drying system in a farfalle pasta production line was exergetically analyzed for assessing and improving the efficiency of the drying process and the entire system along with its main components. Actual operational data were used in the analysis. The exergy efficiency values varied between 0.25% and 5.27% from the predrying to the final drying section being 2.96% for the entire drying system. The highest exergetic improvement in potential rate (IP) was 165.54 kW for the first dryer section. © 2013 John Wiley & Sons Ltd. © 2013 Elsevier B.V. All rights reserved.
Citation - WoS: 46
Citation - Scopus: 49
Splitting the exergy destruction into avoidable and unavoidable parts of a gas engine heat pump (GEHP) for food drying processes based on experimental values
(Pergamon-Elsevier Science Ltd, 2013) Aysegul Gungor; Zafer Erbay; A. Hepbasli; Huseyin Gunerhan; Erbay, Zafer; Hepbasli, Arif; Gunerhan, Huseyin; Gungor, Aysegul
Some limitations in a conventional exergy analysis may be significantly reduced through an advanced exergy analysis. In this regard the latter is a very useful tool to assess the real potential for improving a system component by splitting the exergy destruction into unavoidable and avoidable parts. This may provide a realistic measure to deduct the improvement potential for the thermodynamic efficiency of a component. For this purpose improvement efforts are then made by focusing only on these avoidable parts. In this paper a gas engine heat pump (GEHP) drying system was analyzed using both conventional and advanced exergy analyses. Three medicinal and aromatic plants (Foeniculum vulgare Malva sylvestris L. and Thymus vulgaris) were dried in a pilot scale GEHP drier which was designed constructed and installed in Ege University Izmir Turkey. Drying experiments were performed at an air temperature of 45 C with an air velocity of 1 m/s. For each system component avoidable and unavoidable exergy destructions modified exergy efficiency values and modified exergy destruction ratios were determined. Except for the compressor the evaporator and the drying cabinet most of the exergy destructions in the system components were avoidable and these avoidable parts can be reduced by design improvements. For the HP unit and the overall drying system the values for exergy efficiency were obtained to be in the range of 82.51-85.11% and 79.71-81.66% while those for the modified exergy efficiency were calculated to be in the range of 85.70-89.26% and 84.50-86.00% respectively. © 2013 Elsevier Ltd. All rights reserved. © 2013 Elsevier B.V. All rights reserved.
Citation - WoS: 4
Citation - Scopus: 4
Splitting the exergy destructions of an olive oil refining plant into avoidable and unavoidable parts based on actual operational data
(Inderscience Publishers, 2016) Elif Bozoglan; Zafer Erbay; A. Hepbasli; Huseyin Gunerhan; Erbay, Zafer; Hepbasli, Arif; Bozoglan, Elif; 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%. © 2020 Elsevier B.V. All rights reserved.