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Ibrahim Dincer - One of the best experts on this subject based on the ideXlab platform.

  • investigation of some renewable energy and exergy parameters for two Geothermal District Heating systems
    International Journal of Exergy, 2011
    Co-Authors: C Coskun, Zuhal Oktay, Ibrahim Dincer
    Abstract:

    In this study, three new exergy parameters, namely total exergy destruction ratio, component exergy destruction ratio and dimensionless exergy destruction are introduced in addition to energetic renewability ratio, exergetic renewability ratio, energetic reinjection ratio and exergetic reinjection ratio, and compared for Edremit and Bigadic Geothermal District Heating Systems (GDHSs) based on their actual data. The respective daily graphs of these parameters are presented. Also, regression analyses using the actual data are performed to obtain some correlations for practical use. In brief, these parameters help us to identify the degree of renewability and other aspects and provide some insights.

  • new energy and exergy parameters for Geothermal District Heating systems
    Applied Thermal Engineering, 2009
    Co-Authors: C Coskun, Zuhal Oktay, Ibrahim Dincer
    Abstract:

    This paper introduces four new parameters, namely energetic renewability ratio, exergetic renewability ratio, energetic reinjection ratio, and exergetic reinjection ratio for Geothermal District energy systems. These parameters are applied to Edremit Geothermal District Heating System (GDHS) in Balikesir, Turkey for daily, monthly and yearly assessments and their variations are studied. In addition, the actual data are regressed to obtain some applied correlations for practical use. Some results follow: (i) Both energetic and exergetic renewability ratios decrease with decreasing temperature in Heating season and increasing temperature in the summer. (ii) Both energetic and exergetic reinjection ratios increase with decreasing temperature for Heating season and increase with increasing temperature for summer season.

  • exergoeconomic analysis of the gonen Geothermal District Heating system for buildings
    Energy and Buildings, 2009
    Co-Authors: Zuhal Oktay, Ibrahim Dincer
    Abstract:

    Abstract This paper presents an application of an exergoeconomic model, through exergy and cost accounting analyses, to the Gonen Geothermal District Heating system (GDHS) in Balikesir, Turkey for the entire system and its components. This exergoeconomic model is used to reveal the cost formation process and the productive interaction between components. The exergy destructions in the overall Gonen GDHS are quantified and illustrated for a reference temperature of 4 °C. The results indicate that the exergy destructions in the system occur primarily as a result of losses in the cooled Geothermal water injected back into the reservoir, pumps, heat exchangers, and pipelines. Total exergy destruction and reinjection exergy of the cooled Geothermal water result in 1010 kW (accounting for 32.49%), 320.3 kW (accounting for 10%) of the total exergy input to the Gonen GDHS, respectively. Both energy and exergy efficiencies of the overall Gonen GDHS are also investigated to analyze the system performance, as these efficiencies are determined to be 42% and 50%, respectively. It is found that an increase of the load condition leads to a decrease in the overall thermal costs, which will result in more cost-effective energy systems for buildings.

  • energetic exergetic and environmental assessments of the edremit Geothermal District Heating system
    2008
    Co-Authors: Zuhal Oktay, Ibrahim Dincer
    Abstract:

    Balikesir-Edremit Geothermal Inc. (BEGI) personal support of its General Manager Natural Sciences and Engineering Research Council in Canada

  • energetic and exergetic performance investigation of the bigadic Geothermal District Heating system in turkey
    Energy and Buildings, 2008
    Co-Authors: C Coskun, Zuhal Oktay, Ibrahim Dincer
    Abstract:

    In this study a comprehensive performance analysis of the Bigadic Geothermal District Heating System (GDHS) in Balikesir, Turkey is performed through thermodynamic assessment in terms of energy and exergy efficiencies. The actual thermal data taken from the Technical Department of the GDHS are utilized in the analysis to determine the exergy destructions in each component of the system and the overall energy and exergy efficiencies of the system for two reference temperatures taken as 15.6 °C for November (e.g., case 1) and 11 °C for December (e.g., case 2). The energy and exergy flow diagrams are clearly drawn to illustrate how much destructions/losses take place in addition to the inputs and outputs. The average energy and exergy efficiencies are found to be 30% and 36% for case 1, and 40% and 49% for case 2, respectively. The key reason as to why the exergy efficiencies are higher is because the heat recovery option is used through the reinjection processes which make use of waste heat. A parametric study is also conducted to show how energy and exergy flows change with the environment temperature. The results are expected to be helpful to researchers and engineers in the area.

Arif Hepbasli - One of the best experts on this subject based on the ideXlab platform.

  • comparing advanced exergetic assessments of two Geothermal District Heating systems for residential buildings
    Energy and Buildings, 2014
    Co-Authors: Ali Keçebaş, C Coskun, Zuhal Oktay, Arif Hepbasli
    Abstract:

    Abstract Advanced exergy analysis method has been increasingly utilized in analyzing and assessing the performance of energy-related systems in recent years due to more deeply investigating the exergy destructions. In this study, two various Geothermal District Heating systems (GDHSs), the Afyon and Bigadic GDHSs, which have been operated in Turkey, were considered to perform their advanced exergy analyses and assessments. The GDHSs studied were also compared with each other for the first time in terms of advanced exergetic aspects. In the analyses and calculations of the GDHS, the actual operational data obtained from the measurements and technical staff were utilized. The overall conventional and advanced exergetic efficiency values for the Afyon GDHS are determined to be 27.53% and 34.72% while those for the Bigadic GDHS are obtained to be 21.03% and 32.52%, respectively. Considering both the interactions among components and the potential for improving components, more effective and efficient improvement priorities were proposed.

  • Conventional and advanced exergoeconomic analyses of Geothermal District Heating systems
    Energy and Buildings, 2014
    Co-Authors: Ali Keçebaş, Arif Hepbasli
    Abstract:

    Abstract The present study deals with analyzing, assessing and comparing conventional and advanced exergoeconomic analyses to identify the direction and potential for energy savings of a Geothermal District Heating system in future conditions/projections. As a real case study, the Afyon Geothermal District Heating system in Afyonkarahisar, Turkey, is considered while its actual operational thermal data on 8 February 2011 are utilized in the analysis, which is based on the specific exergy costing method. In this study for the first time, based on the concepts of avoidable/unavoidable and endogenous/exogenous parts, cost rates associated with both exergy destruction and capital investment of the Geothermal District Heating system are determined first, and the obtained results are then evaluated. The results indicate that the internal design changes play a more essential role in determining the cost of each component. The cost rate of unavoidable part within the components of the system is lower than that of the avoidable one. For the overall system, the value for the conventional exergoeconomic factor is determined to be 5.53% while that for the modified one is calculated to be 9.49%. As a result, the advanced exergoeconomic analysis makes more sense given the additional information in splitting process of the components.

  • a comparative study on conventional and advanced exergetic analyses of Geothermal District Heating systems based on actual operational data
    Energy and Buildings, 2013
    Co-Authors: Arif Hepbasli, Ali Keçebaş
    Abstract:

    Abstract This paper comparatively evaluates exergy destructions of a Geothermal District Heating system (GDHS) using both conventional and advanced exergetic analysis methods to identify the potential for improvement and the interactions among the components. As a real case study, the Afyon GDHS in Afyonkarahisar, Turkey, is considered based on actual operational data. For the first time, advanced exergetic analysis is applied to the GDHSs, in which the exergy destruction rate within each component is split into unavoidable/avoidable and endogenous/exogenous parts. The results indicate that the interconnections among all the components are not very strong. Thus, one should focus on how to reduce the internal inefficiency (destruction) rates of the components. The highest priority for improvement in the advanced exergetic analysis is in the re-injection pump (PM-IX), while it is the heat exchanger (HEX-III) in the conventional analysis. In addition, there is a substantial influence on the overall system as the total avoidable exergy destruction rate of the heat exchanger (HEX-V) has the highest value. On the overall system basis, the value for the conventional exergetic efficiency is determined to be 29.29% while that for the modified exergetic efficiency is calculated to be 34.46% through improving the overall components.

  • a review on energetic exergetic and exergoeconomic aspects of Geothermal District Heating systems gdhss
    Energy Conversion and Management, 2010
    Co-Authors: Arif Hepbasli
    Abstract:

    Abstract Geothermal is a reliable and promising renewable energy. In 1892 the first Geothermal District Heating system (GDHS) began operations in Boise, Idaho, USA. Since then, a number of GDHSs installations have been made worldwide. Various investigations on the efficient utilization of Geothermal energy resources have also been conducted to attain sustainable development. There is a link between exergy and sustainable development. In recent years, exergy analysis has been widely used in the design, simulation and performance assessment of thermal systems. Exergoeconomic analysis, which is a combination of exergy and economics, is nowadays considered a powerful tool to study and optimize various types of energy-related systems. The present study comprehensively reviews GDHSs in terms of three aspects, namely energetic, exergetic and exergoeconomic analyses and assessments, for the first time to the best of the author’s knowledge. A brief historical development of the studies on GDHSs was given on the base of these three aspects first. Next, GDHSs analyzed were schematically presented and shortly described. The previously conducted studies on GDHSs were then reviewed and classified. Finally, the conclusions were presented. It is expected that this comprehensive study will be very beneficial to everyone involved or interested in the energetic, exergetic and exergoeconomic design, analysis and performance evaluation of GDHSs.

  • determination of optimum pipe diameter along with energetic and exergetic evaluation of Geothermal District Heating systems modeling and application
    Energy and Buildings, 2008
    Co-Authors: Yildiz Kalinci, Arif Hepbasli, Ismail H Tavman
    Abstract:

    Abstract This study deals with determination of optimum pipe diameters based on economic analysis and the performance analysis of Geothermal District Heating systems along with pipelines using energy and exergy analysis methods. In this regard, the Dikili Geothermal District Heating system (DGDHS) in Izmir, Turkey is taken as an application place, to which the methods presented here are applied with some assumptions. The system mainly consists of three cycles, namely (i) the transportation network, (ii) the Danistay region, and (iii) the Bariskent region. The thermal capacities of these regions are 21,025 and 7975 kW, respectively, while the supply (flow) and return temperature values of those are 80 and 50 °C, respectively. Based upon the assessment of the transportation network using the optimum diameter analysis method, minimum cost is calculated to be US$ 561856.906 year −1 for a nominal diameter of DN 300. The exergy destructions in the overall DGDHS are quantified and illustrated using exergy flow diagram. Furthermore, both energy and exergy flow diagrams are exhibited for comparison purposes. It is observed through analysis that the exergy destructions in the system particularly take place due to the exergy of the thermal water (Geothermal fluid) reinjected, the heat exchanger losses, and all pumps losses, accounting for 38.77%, 10.34%, 0.76% of the total exergy input to the DGDHS. Exergy losses are also found to be 201.12817 kW and 1.94% of the total exergy input to the DGDHS for the distribution network. For the system performance analysis and improvement, both energy and exergy efficiencies of the overall DGDHS are investigated, while they are determined to be 40.21% and 50.12%, respectively.

Ali Keçebaş - One of the best experts on this subject based on the ideXlab platform.

  • exergoenvironmental analysis for a Geothermal District Heating system an application
    Energy, 2016
    Co-Authors: Ali Keçebaş
    Abstract:

    Energy sources are of great importance in relation to pollution of the world. The use of renewable energy resources and the creation of more efficient energy systems make great contributions to the prevention of greenhouse gases. Recently, many studies indicate that the energy conversion systems have many advantages in terms of technical and economic point of view. In near future, environmental impact is going to play an important role in the selection/design of such energy resources and systems. In this study, the Afyon GDHS (Geothermal District Heating system) having actual operating conditions is investigated at the component level in terms of environmental impact by using exergoenvironmental analysis. Moreover, the effects of ambient and wellhead temperatures on the environmental impacts of the system are discussed. The results show that a great part of total environmental impact of the system occurs from the exergy destructions of the components. Therefore, the environmental impacts can be reduced by improving their exergetic efficiencies instead of design changes of the system components. The environmental impacts of the system are reduced when the ambient temperature decreases and the wellhead temperature increases. Thus, it might not be necessary to conduct separately the exergoenvironmental analysis for different ambient temperatures.

  • comparing advanced exergetic assessments of two Geothermal District Heating systems for residential buildings
    Energy and Buildings, 2014
    Co-Authors: Ali Keçebaş, C Coskun, Zuhal Oktay, Arif Hepbasli
    Abstract:

    Abstract Advanced exergy analysis method has been increasingly utilized in analyzing and assessing the performance of energy-related systems in recent years due to more deeply investigating the exergy destructions. In this study, two various Geothermal District Heating systems (GDHSs), the Afyon and Bigadic GDHSs, which have been operated in Turkey, were considered to perform their advanced exergy analyses and assessments. The GDHSs studied were also compared with each other for the first time in terms of advanced exergetic aspects. In the analyses and calculations of the GDHS, the actual operational data obtained from the measurements and technical staff were utilized. The overall conventional and advanced exergetic efficiency values for the Afyon GDHS are determined to be 27.53% and 34.72% while those for the Bigadic GDHS are obtained to be 21.03% and 32.52%, respectively. Considering both the interactions among components and the potential for improving components, more effective and efficient improvement priorities were proposed.

  • Conventional and advanced exergoeconomic analyses of Geothermal District Heating systems
    Energy and Buildings, 2014
    Co-Authors: Ali Keçebaş, Arif Hepbasli
    Abstract:

    Abstract The present study deals with analyzing, assessing and comparing conventional and advanced exergoeconomic analyses to identify the direction and potential for energy savings of a Geothermal District Heating system in future conditions/projections. As a real case study, the Afyon Geothermal District Heating system in Afyonkarahisar, Turkey, is considered while its actual operational thermal data on 8 February 2011 are utilized in the analysis, which is based on the specific exergy costing method. In this study for the first time, based on the concepts of avoidable/unavoidable and endogenous/exogenous parts, cost rates associated with both exergy destruction and capital investment of the Geothermal District Heating system are determined first, and the obtained results are then evaluated. The results indicate that the internal design changes play a more essential role in determining the cost of each component. The cost rate of unavoidable part within the components of the system is lower than that of the avoidable one. For the overall system, the value for the conventional exergoeconomic factor is determined to be 5.53% while that for the modified one is calculated to be 9.49%. As a result, the advanced exergoeconomic analysis makes more sense given the additional information in splitting process of the components.

  • thermodynamic and economic evaluations of a Geothermal District Heating system using advanced exergy based methods
    Energy Conversion and Management, 2014
    Co-Authors: Mehmet Tan, Ali Keçebaş
    Abstract:

    Abstract In this paper, a Geothermal District Heating system (GDHS) is comparatively evaluated in terms of thermodynamic and economic aspects using advanced exergy-based methods to identify the potential for improvement, the interactions among system components, and the direction and potential for energy savings. The actual operational data are taken from the Saraykoy GDHS, Turkey. In the advanced exergetic and exergoeconomic analyses, the exergy destruction and the total operating cost within each component of the system are split into endogenous/exogenous and unavoidable/avoidable parts. The advantages of these analyses over conventional ones are demonstrated. The results indicate that the advanced exergy-based method is a more meaningful and effective tool than the conventional one for system performance evaluation. The exergetic efficiency and the exergoeconomic factor of the overall system for the Saraykoy GDHS were determined to be 43.72% and 5.25% according to the conventional tools and 45.06% and 12.98% according to the advanced tools. The improvement potential and the total cost-savings potential of the overall system were also determined to be 2.98% and 14.05%, respectively. All of the pumps have the highest improvement potential and total cost-savings potential because the pumps were selected to have high power during installation at the Saraykoy GDHS.

  • An economic comparison and evaluation of two Geothermal District Heating systems for advanced exergoeconomic analysis
    Energy Conversion and Management, 2014
    Co-Authors: Pınar Keçebaş, Harun Gökgedik, Mehmet Ali Alkan, Ali Keçebaş
    Abstract:

    This paper refers to an economic comparison and evaluation of two Geothermal District Heating systems (GDHSs) under same reference state condition and mechanic/economic parameters by using an advanced exergoeconomic analysis. In this analysis, costs of investment and exergy destruction of each component for the thermal systems such as the Afyon and Saraykoy GDHSs were split into endogenous/exogenous and unavoidable/avoidable parts, and were also compared with each other for the first time. The results obtained show that the advanced exergoeconomic analysis makes the information more accurate and useful, and supplies additional information that cannot be provided by the conversional analysis. Furthermore, the Afyon GDHS can be made more cost effectiveness, removing the system components’ irreversibilities, technical-economic limitations, and poorly chosen manufacturing methods, according to the Saraykoy GDHS. The majority of the components in the Saraykoy GDHS are to operate more economically than those in the Afyon GDHS. As a result, the usefulness of this method was clearly demonstrated comparing both the systems.

Leyla Ozgener - One of the best experts on this subject based on the ideXlab platform.

Zuhal Oktay - One of the best experts on this subject based on the ideXlab platform.

  • comparing advanced exergetic assessments of two Geothermal District Heating systems for residential buildings
    Energy and Buildings, 2014
    Co-Authors: Ali Keçebaş, C Coskun, Zuhal Oktay, Arif Hepbasli
    Abstract:

    Abstract Advanced exergy analysis method has been increasingly utilized in analyzing and assessing the performance of energy-related systems in recent years due to more deeply investigating the exergy destructions. In this study, two various Geothermal District Heating systems (GDHSs), the Afyon and Bigadic GDHSs, which have been operated in Turkey, were considered to perform their advanced exergy analyses and assessments. The GDHSs studied were also compared with each other for the first time in terms of advanced exergetic aspects. In the analyses and calculations of the GDHS, the actual operational data obtained from the measurements and technical staff were utilized. The overall conventional and advanced exergetic efficiency values for the Afyon GDHS are determined to be 27.53% and 34.72% while those for the Bigadic GDHS are obtained to be 21.03% and 32.52%, respectively. Considering both the interactions among components and the potential for improving components, more effective and efficient improvement priorities were proposed.

  • investigation of a hybrid solar and Geothermal driven absorption cooling system for District applications
    International Journal of Exergy, 2012
    Co-Authors: C Cosku, Zuhal Oktay, Ibrahim Dince
    Abstract:

    In this paper, a new hybrid Geothermal and solar driven absorption cooling system (ACS) is proposed for low–temperature District energy applications. Two approaches are proposed in this study, namely: a) a new model for determining the specific entropy values of LiBr–water solution and (b) two new energetic and exergetic parameters, namely Geothermal contribution index and solar contribution index. A feasibility study of incorporating a solar driven ACS into Bigadic Geothermal District Heating System is considered and investigated in this regard. Some parametric studies are conducted to highlight the importance of the present study and make a practical illustration.

  • investigation of some renewable energy and exergy parameters for two Geothermal District Heating systems
    International Journal of Exergy, 2011
    Co-Authors: C Coskun, Zuhal Oktay, Ibrahim Dincer
    Abstract:

    In this study, three new exergy parameters, namely total exergy destruction ratio, component exergy destruction ratio and dimensionless exergy destruction are introduced in addition to energetic renewability ratio, exergetic renewability ratio, energetic reinjection ratio and exergetic reinjection ratio, and compared for Edremit and Bigadic Geothermal District Heating Systems (GDHSs) based on their actual data. The respective daily graphs of these parameters are presented. Also, regression analyses using the actual data are performed to obtain some correlations for practical use. In brief, these parameters help us to identify the degree of renewability and other aspects and provide some insights.

  • new energy and exergy parameters for Geothermal District Heating systems
    Applied Thermal Engineering, 2009
    Co-Authors: C Coskun, Zuhal Oktay, Ibrahim Dincer
    Abstract:

    This paper introduces four new parameters, namely energetic renewability ratio, exergetic renewability ratio, energetic reinjection ratio, and exergetic reinjection ratio for Geothermal District energy systems. These parameters are applied to Edremit Geothermal District Heating System (GDHS) in Balikesir, Turkey for daily, monthly and yearly assessments and their variations are studied. In addition, the actual data are regressed to obtain some applied correlations for practical use. Some results follow: (i) Both energetic and exergetic renewability ratios decrease with decreasing temperature in Heating season and increasing temperature in the summer. (ii) Both energetic and exergetic reinjection ratios increase with decreasing temperature for Heating season and increase with increasing temperature for summer season.

  • exergoeconomic analysis of the gonen Geothermal District Heating system for buildings
    Energy and Buildings, 2009
    Co-Authors: Zuhal Oktay, Ibrahim Dincer
    Abstract:

    Abstract This paper presents an application of an exergoeconomic model, through exergy and cost accounting analyses, to the Gonen Geothermal District Heating system (GDHS) in Balikesir, Turkey for the entire system and its components. This exergoeconomic model is used to reveal the cost formation process and the productive interaction between components. The exergy destructions in the overall Gonen GDHS are quantified and illustrated for a reference temperature of 4 °C. The results indicate that the exergy destructions in the system occur primarily as a result of losses in the cooled Geothermal water injected back into the reservoir, pumps, heat exchangers, and pipelines. Total exergy destruction and reinjection exergy of the cooled Geothermal water result in 1010 kW (accounting for 32.49%), 320.3 kW (accounting for 10%) of the total exergy input to the Gonen GDHS, respectively. Both energy and exergy efficiencies of the overall Gonen GDHS are also investigated to analyze the system performance, as these efficiencies are determined to be 42% and 50%, respectively. It is found that an increase of the load condition leads to a decrease in the overall thermal costs, which will result in more cost-effective energy systems for buildings.