Browsing by Author "Gunerhan, Huseyin"

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Citation - WoS: 26
Citation - Scopus: 29
A comprehensive evaluation of PV electricity production methods and life cycle energy-cost assessment of a particular system
(ELSEVIER SCI LTD, 2019) Huseyin Gunhan Ozcan; Huseyin Gunerhan; Nurdan Yildirim; Arif Hepbasli; Ozcan, Huseyin Gunhan; Yildirim, Nurdan; Hepbasli, Arif; Gunerhan, Huseyin
This paper presents the study about electricity generation from solar photovoltaic technology based on four different methodologies with some performance indicators namely performance ratio system efficiency fill and capacity utilization factors respectively. In this regard not only theoretical approach and simulation programs (PVSOL and TRNSYS) were used to determine annual production but also experimental studies were carried out for the validation. While annual sum of electricity generation was evaluated between 3913.84 and 4323.94 kWh the PVSOL program was determined to be the method that best reflected the experimental studies with a rate of 94.33%. Moreover while fill and capacity utilization factors were annually obtained to be almost similar annual values for the performance ratio and system efficiency were evaluated to be partially close to each other based on the theoretical approach and PVSOL program. Besides evaluation of the power production and performance indicators a life cycle energy analysis was also made for a particular system with a capacity of 2.55 kWp and energy payback periods were obtained to be between 1.99 and 2.54 years considering four different methodologies. Moreover the life cycle cost analysis was performed with or without battery option and some improvement proposals were presented for the energy market to become investable. (C) 2019 Elsevier Ltd. All rights reserved.
Citation - WoS: 168
Citation - Scopus: 211
A key review of wastewater source heat pump (WWSHP) systems
(Elsevier Ltd, 2014) A. Hepbasli; Emrah Biyik; Orhan Ekren; Huseyin Gunerhan; Mustafa Araz; Ekren, Orhan; Araz, Mustafa; Hepbasli, Arif; Gunerhan, Huseyin; Biyik, Emrah
Heat pumps (HPs) are part of the environmentally friendly technologies using renewable energy and have been utilized in the developed countries for years. Wastewater is seen as a renewable heat source for HPs. At the beginning of the 1980s waste (sewage) water source heat pumps (WWSHPs) were widely applied in North European countries like Sweden and Norway and partially applied in China. In the past two decades the WWSHP has become increasingly popular due to its advantages of relatively higher energy utilization efficiency and environmental protection. The present study comprehensively reviews WWSHP systems in terms of applications and performance assessments including energetic exergetic environmental and economic aspects for the first time to the best of the authors' knowledge. In this context a historical development of WWSHPs was briefly given first. Next wastewater potential and its characteristics were presented while a WWSHP system was introduced. The previously conducted studies on WWSHPs were then reviewed and classified in a tabulated form. Finally some concluding remarks were listed. The COP values of the reviewed studies ranged from 1.77 to 10.63 for heating and 2.23 to 5.35 for cooling based on the experimental and simulated values. The performance assessments are mostly made using energy analysis methods while the number of exergetic evaluations is very low and has not been comprehensively performed. It is expected that the comprehensive review here will be very beneficial to those dealing with the design analysis simulation and performance assessment of WWSHP systems. © 2017 Elsevier B.V. All rights reserved.
Citation - WoS: 7
Citation - Scopus: 6
Achieving ultra-high coefficient of performance in a novel solar-assisted trigeneration system integrating absorption and Rankine cycles
(Elsevier Ltd, 2025) Aslı Tiktaş; A. Hepbasli; Huseyin Gunerhan; Hepbasli, Arif; Gunerhan, Huseyin; Tiktas, Asli
A novel solar-driven trigeneration system was developed and thermodynamically assessed integrating an absorption heat transformer (AHT) a Rankine cycle (RC) and an absorption cooling cycle (ACC) into a unified configuration. The innovation lay not only in the use of an AHT to power the RC—an uncommon integration in itself—but more significantly in the full thermodynamic loop architecture that employed a single working fluid pair (LiBr–H2O) shared by both absorption subsystemswhile also driving a steam-based Rankine subsystem. This tightly coupled single-loop design enabled internal thermal cascading and eliminated the need for separate working fluids auxiliary heating or intermediate heat exchangers— unlike conventional hybrid or cascade systems which (i) rely on multiple working fluid loops for power and cooling (ii) require fossil-fueled auxiliary heaters to drive RCs or (iii) incur high irreversibility losses due to fluid-to-fluid heat exchange between subsystems. Based on the simulation results a net electrical power output of 457.90 kW an overall exergetic efficiency of 74.40 % and a RC energy efficiency of 56.30 % were obtained. The cooling coefficient of performance (COP) reached 7.03 significantly outperforming conventional single-effect absorption systems. The system was fully powered by flat-plate solar collectors (FPSCs) without requiring any fossil-based auxiliary energy. A comprehensive validation was performed using component-level comparisons with experimental studies covering pressure drops internal irreversibility and the influence of working fluid properties on performance metrics. Additionally detailed thermo-economic assessments were carried out. The total investment cost was approximately US$8.54 million with a remarkably short payback period (PP) of 2.56 years and an internal rate of return (IRR) of 24.43 %. Levelized costs of electricity cooling and heating were calculated as US$0.20/kWh US$0.024/kWh and US$0.024/kWh respectively. Comparative analysis against literature benchmarks proven that the proposed system offered superior thermodynamic and economic performance especially in cooling and heating outputs. This study showed a new design paradigm for low-grade renewable energy utilization providing both a scalable solution for high efficiency multigeneration and a practical framework for future sustainable energy systems. © 2025 Elsevier B.V. All rights reserved.
Citation - WoS: 64
Citation - Scopus: 75
Advanced exergoeconomic analysis of a gas engine heat pump (GEHP) for food drying processes
(PERGAMON-ELSEVIER SCIENCE LTD, 2015) Aysegul Gungor; George Tsatsaronis; Huseyin Gunerhan; Arif Hepbasli; Tsatsaronis, George; Hepbasli, Arif; Gunerhan, Huseyin; Gungor, Aysegul
Exergetic and exergoeconomic analyses are often used to evaluate the performance of energy systems from the thermodynamic and economic points of view. While a conventional exergetic analysis can be used to recognize the sources of inefficiencies the so-called advanced exergy-based analysis is convenient for identifying the real potential for thermodynamic improvements and the system component interactions by splitting the exergy destruction and the total operating cost within each component into endogenous/ exogenous and unavoidable/avoidable parts. In this study for the first time an advanced exergoeconomic analysis is applied to a gas-engine-driven heat pump (GEHP) drying system used in food drying for evaluating its performance along with each component. The advanced exergoeconomic analysis shows that the unavoidable part of the exergy destruction cost rate within the components of the system is lower than the avoidable part. The most important components based on the total avoidable costs are drying ducts the condenser and the expansion valve. The inefficiencies within the condenser could particularly be improved by structural improvements of the whole system and the remaining system components. Finally it can be concluded that the internal design changes play a more essential role in determining the cost of each component. (C) 2014 Elsevier Ltd. All rights reserved.
Citation - WoS: 9
Citation - Scopus: 13
Assessing Exergy-Based Economic and Sustainability Analyses of a Military Gas Turbine Engine Fueled with Various Fuels
(MDPI AG rasetti@mdpi.com Postfach Basel CH-4005, 2020) Burak Yuksel; Huseyin Gunerhan; A. Hepbasli; Yuksel, Burak; Gunerhan, Useyin; Hepbasli, Arif; Gunerhan, Huseyin
This research put forth exergy-based economic and sustainability analyses of a (J85-GE-5H) military turbojet engine (TJE). Firstly sustainability conventional exergoeconomic and advanced exergoeconomic cost analyses were executed utilizing kerosene fuel according to real engine working circumstances. The engine was likewise investigated parametrically considering H2 fuel utilization. The sustainable economic analysis assessment of the TJE was finally actualized by comparing the acquired outcomes for both fuels. The entire engine's unit exergy cost of product ( ) cPr with kerosene was determined 76.45 $/GJ for the military (MIL) process mode (PM) whereas it was computed 94.97 $/GJ for the afterburner (AB) PM. Given the use of H2 the cPr increased to 179 and 288 $/GJ for the aforementioned two modes seriatim. While the sustainability cost index (SCI) values were obtained 52.86 and 78.84 $/GJ for the MIL and AB PM seriatim they became 128 and 244 $/GJ when considering H2. Consequently the higher exergy demolitions occurring in the afterburner exhaust duct (ABED) and combustion chamber (CC) sections led to higher exergy destruction costs in the TJE. However the engine worked less cost efficient with H2 fuel rather than JP-8 fuel because of the higher cost value of fuel. © 2020 Elsevier B.V. All rights reserved.
Citation - WoS: 21
Citation - Scopus: 24
Comparative performance metric assessment of a military turbojet engine utilizing hydrogen and kerosene fuels through advanced exergy analysis method
(MDPI AG rasetti@mdpi.com Postfach Basel CH-4005, 2020) Burak Yuksel; Ozgur Balli; Huseyin Gunerhan; A. Hepbasli; Yuksel, Burak; Balli, Ozgur; Hepbasli, Arif; Gunerhan, Huseyin
This study dealt with evaluating the (J85-GE-5H) military turbojet engine (TJE) in terms of exergetic and advanced exergetic analyses at Military (MIL) and Afterburner (AB) process modes by utilizing kerosene (JP-8) and hydrogen (H2) fuels. First exergy and advanced exergy analyses of the engine were performed using JP-8 fuel as per actual engine operating conditions. These analyses of the turbojet engine using hydrogen fuel were also examined parametrically. The performance evaluation of the engine was lastly executed by comparing the obtained results for both fuels. Based on the parametric studies undertaken the entire engine’s exergetic efficiency with JP-8 was reckoned 30.85% at the MIL process mode while it was calculated as 16.98% at the AB process mode. With the usage of H2 the efficiencies of the engine decreased to 28.62% and 15.33% for the above mentioned two modes respectively. As the supreme exergy destructions occurred in the combustion chamber (CC) and afterburner exhaust duct (ABED) segments the new technological developments should be considered to design more efficient engines. As a result the engine worked less efficiently with hydrogen fuel due to the enhancement in exergy destructions. Conversely the greenhouse gas (GHG) emission parameters lessened with the utilization of H2 fuel. © 2020 Elsevier B.V. All rights reserved.
Energy and Exergy Assessments of a Single Flash Geothermal and Orc System with Packed Bed Storage Using Olive Pomace
(Vinca Inst Nuclear Sci, 2025) Hepbasli, Arif; Gunerhan, Huseyin; Yalcinkaya, Deniz Yildirim
This study presents a detailed analysis of a packed bed thermal energy storage system, supported by a critical review of similar configurations in the literature. The research emphasizes the impact of working fluids on overall system performance. Key parameters including thermal storage capacity, heat transfer mechanisms, pressure drop, air-flow velocity, biomass feed rate, and heat transfer fluid temperature are assessed for their roles in determining system behavior. The main objective is to develop an innovative system that integrates an ORC with a single flash geothermal unit. Thermodynamic assessments, covering both energy and exergy analyses, were performed usingMATLAB in conjunction with the CoolProp library to ensure precise thermophysical property data. Departing from conventional geothermal set-ups, this study introduces a novel ORC-SFGEO integration. While R245fa remains a benchmark working fluid, the study also evaluates low global warming potential alternatives including R1233zd(E), R1234ze(Z), R1234ze(E), and R1234yf commonly used in heat pumps to enhance thermodynamic and environmental performance. Results show that the integrated system yields a 40% performance increase compared to similar systems in the literature. The energy and exergy efficiencies of the base system, without a heat pump, are 24.26% and 7.51%, respectively. When the HPS is integrated, exergy efficiency improves by 55.5%, addressing fluctuations in solar input.
Energy and Exergy Assessments of a Single Flash Geothermal and Orc System with Packed Bed Storage Using Olive Pomace
(Serbian Society of Heat Transfer Engineers, 2025) Hepbasli, Arif; Gunerhan, Huseyin; Yalcinkaya, Deniz Yildirim
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: 2
Citation - Scopus: 2
Enhanced exergy analyses of a gas engine heat pump (GEHP) dryer for medicinal and aromatic plants
(INDERSCIENCE ENTERPRISES LTD, 2015) Aysegul Gungor; Arif Hepbasli; Huseyin Gunerhan; Hepbasli, Arif; Gunerhan, Huseyin; Gungor, Aysegul
In this study the performance of a gas engine heat pump (GEHP) drying system is evaluated using both conventional and advanced (or enhanced) exergetic analysis methods. The results indicated that the inefficiencies within the compressor and the drying ducts are mainly due to the internal operating conditions while the efficiency of the condenser could be improved by structural improvements of the whole system and the remaining system components. High levels of endogenous exergy destruction show that the component interactions do not contribute significantly to the thermodynamic inefficiencies. Thus one should focus on how to reduce the internal inefficiency rates of the components. On the overall system basis the value for the conventional exergetic efficiency is in the range of 79.71-81.66% while that for the modified exergetic efficiency varies between 84.50 and 86.00% through improving the overall components.
EXERGETIC ANALYSIS OF A SOLAR ENERGY-BASED HYDROGEN PRODUCTION SYSTEM
(International Association for Hydrogen Energy IAHE, 2022) Hilal Akci; Huseyin Gunerhan; A. Hepbasli; Hepbasli, Arif; Akci, Hilal; Gunerhan, Huseyin; I. Dincer , C.C. Colpan , M.A. Ezan
In this study energy exergy and sustainability analyses are performed for a solar energy-based hydrogen production system which is modeled with TRNSYS and Engineering Equation Solver (EES) software packages. This system consists of solar photovoltaic panels (PVs) a controller an electrolyzer a metal hydride hydrogen tank used for hydrogen production and storage and Proton Exchange Membrane Fuel Cell (PEMFC) for electricity storage. Dead state temperature is taken as 0 ºC. The results revealed that the PEMFC had the highest energy efficiency of 53.28%. Exergy efficiencies of the solar PV panel the electrolyzer and the PEMFC were determined to be 9.66% 60% and 29.39% respectively. The exergetic sustainability index of the electrolyzer had the maximum value of 2.501. © 2023 Elsevier B.V. All rights reserved.
Citation - WoS: 3
Citation - Scopus: 3
Exergoeconomic and exergoenvironmental assessment of a PV/T assisted wastewater source heat pump system for a sustainable future
(INDERSCIENCE ENTERPRISES LTD, 2021) Mustafa Araz; Arif Hepbasli; Huseyin Gunerhan; Hepbasli, Arif; Gunerhan, Huseyin; Araz, Mustafa
This paper investigated exergetic exergoeconomical and exergoenvironmental performances of a photovoltaic/thermal (PV/T) assisted wastewater source heat pump (WWSHP) system. The highest relative irreversibility among all the components occurred in the PV/T unit followed by the compressor. The functional exergy efficiencies of the WWSHP and whole system were found to be 0.10 and 0.15 respectively. The exergoeconomic factors of the condenser and wastewater heat exchanger were determined to be considerably high among all the components. The highest exergy loss per unit price was due to the PV/T system. Exergoeconomic factors for each equipment and the entire system decreased with increasing yearly working period and decreasing interest rate. The same trend was also observed in the specific cost of exergetic product. Exergy destruction related environmental impacts were found to be the major element in almost all of the components and therefore its reduction should be the main focus on exergoenvironmental performance improvements.
Citation - WoS: 13
Citation - Scopus: 13
Exergoeconomic optimization of a proposed novel combined solar powered electricity and high-capacity cooling load production system for economical and potent generation via utilization of low-grade waste heat source
(ELSEVIER, 2024) Asli Tiktas; Huseyin Gunerhan; Arif Hepbasli; Hepbasli, Arif; Gunerhan, Huseyin; Tiktas, Asli
A novel system for combined electricity and cooling generation was introduced integrating Flat Plate Solar Collectors (FPSC) Absorptional Heat Transformer (AHT) Organic Rankine Cycle (ORC) and Absorption Cooling Cycle (ACC) systems to utilize low-grade solar energy. The ability to use low-grade waste heat sources (70 degrees C-90 degrees C) via FPSC system for high-capacity integrated cooling and electricity generation in a more economical way a feature not commonly addressed in conventional systems and previous literature studies was a key advancement. The need for additional generators boilers and high-temperature heat sources was eliminated resulting in substantial cost savings and a simplified system design. The FPSC-AHT integration identified as having significant advantages over separate electricity and cooling load production was comprehensively evaluated for its combined exergoeconomic and environmental benefits in multigeneration system design. The modeling was performed using Engineering Equation Solver (EES) and Transient System Simulation Software (TRNSYS) in Izmir Turkey with the aim of achieving the heightened economic efficiency and superior Coefficient of Performance (COP) values without high-temperature waste heat sources. Three configurations were examined with the third demonstrating superior technoeconomic performance due to the increased thermal efficiency of solar hybrid photovoltaic-thermal (PV-T) systems. The higher cost per unit area in the PV-T system was effectively offset by the substantial electricity consumption contributing to energy savings. Economic indicators for the third configuration included an initial investment of US$9.91 million annual operational costs of US$1.29 million a payback period of 4.2 years an annual energy cost gain of US$9.25 million a levelized cost of cooling (LCC) of US$0.014/kWh and an electricity cost (LCE) of US$0.015/kWh. Through exergy analysis toluene was identified as the optimal working fluid revealing a total exergy destruction rate of 13245.46 kW. The performance of the proposed system was tested under different operation conditions and based on these results a sensitivity analysis and a comparison with the real-word studies were performed. In comparison to real- world data the proposed system exhibits superior performance metrics especially in terms of COP and exergy efficiency values. The optimal configuration established using single and multiobjective optimization approaches based on exergoeconomic parameters indicated annual electricity and cooling load production of 40000 MWh and 300 GWh respectively. The system's efficiency in producing 1000 kW of electricity power and 4000 kW of cooling load at a comparable cost to systems generating only one output was highlighted. To determine the technoeconomic performance improvement of the proposed integrated system the optimal configuration of the novel integrated system was compared to a reference plant for similar-scaled integrated power and cooling generation (UCI Trigeneration Plant). Compared to the UCI Trigeneration Plant the proposed system demonstrated significant improvements in technoeconomic performance. Specifically the proposed system achieved a 164.13 % increase in annual electricity production a 97.38 % increase in annual cooling duty a 60.36 % reduction in initial investment a 57 % reduction in annual operational costs and a 47.5 % reduction in payback period. Additionally the levelized costs of electricity and cooling were 40 % and 22.22 % lower respectively. Significantly higher electricity and cooling output highlights the system's ability to meet demanding energy needs. Lower initial investment and operational costs coupled with a reduced payback period make the system financially attractive. Lower levelized costs for electricity and cooling increase the system's competitiveness and affordability. The innovative integration of technologies provides new insights into the design of multigeneration systems setting a new benchmark for sustainable energy solutions.
Citation - WoS: 9
Exergy and sustainability-based optimisation of flat plate solar collectors by using a novel mathematical model
(INDERSCIENCE ENTERPRISES LTD, 2023) Asli Tiktas; Huseyin Gunerhan; Arif Hepbasli; Hepbasli, Arif; Gunerhan, Huseyin; Tiktas, Asli
A novel mathematical model was used to estimate optimum tilt and azimuth angles considering exergoeconomic and sustainability aspects. This approach made the solar collector's performance evaluation independent of experimental precision. The optimal angles of 41.191degree celsius 10.038degree celsius for Izmir maximised the total surface radiation exergetic efficiency exergetic sustainability index and minimised the destruction and cost rates due to the enhanced useful exergy stream. However for thermal efficiency maximisation useful collected solar energy and total surface radiation competed leading to lower tilt and azimuth angles (0 -0.008). A multi-objective optimisation process chose the pair (0 259.428) to maximise first law efficiency and exergoeconomic factor.
Citation - WoS: 18
Citation - Scopus: 18
Exergy-based techno-economic and environmental assessments of a proposed integrated solar powered electricity generation system along with novel prioritization method and performance indices
(ELSEVIER, 2023) Asli Tiktas; Huseyin Gunerhan; Arif Hepbasli; Emin Acikkalp; Açıkkalp, Emin; Tiktaş, Aslı; Hepbasli, Arif; Gunerhan, Huseyin
This study focused on the two important gaps in the literature. The first is solar energy- powered electricity generation in a more economical way via the integration of flat plate solar collector (FPSC) an Organic Rankine Cycle (ORC) and an absorptional heat transformer (AHT) system. Another gap is advanced exergy analysis of the AHT cycle/ORC process based on renewable energy integration to reveal clues for improving the system. To close these gaps a novel system including a lithium bromide AHT cycle-ORC with a FPSC system application was proposed in this study. In this proposed system the temperature of the heat source for the ORC system was upgraded via an integration of the AHT and FPSC cycles. The main components of the AHT cycle are the condenser (ABScon) refrigerant cycle pump (P1) evaporator (EV) absorber (ABS) solution heat exchanger (SHX) absorbent cycle pump (P2) expansion valve (V) generator (Gen) ORC turbine (ORCT) and ORC condenser (ORCcon). To demonstrate the electricity production from solar energy in a more economical way thanks to the proposed system a comparison was made with similar-scaled existing solar power plants. The results supported the main purpose of this study. The annual electricity production with the proposed system was calculated as 2601 MWh with initial investment cost and payback period values of US$3.924 million and 4.531 years respectively. The conventional and advanced exergy exergoeconomic environmental impact and sustainability analyzes were also performed. Based on these the novel performance parameters and prioritization method were proposed to assess the improvement potential of the system. The results indicated that SHX and FPSC had the highest exergy destruction rates (EDRs) of 23.711% and 21.849% over 5853.89 kW due to the stronger thermal and chemical reactions. Similarly Gen FPSC and SHX had the highest ED cost rates (CRs) of 67.59% 59.09% and 47.98% respectively. Gen V and ORCcon were higher contributors to the exergy destruction rates of almost all the components. However these showed an adverse manner for irreversibility activities. So the temperatures of Gen and ORCcon should be optimized carefully. ABScon P2 P1 ABS Gen ORCT and ORCcon had high development priority to improve the whole system.
Citation - WoS: 5
Citation - Scopus: 5
Experimental exergoeconomic performance assessment of a wastewater source heat pump system
(Inderscience Publishers, 2019) Mustafa Araz; A. Hepbasli; Huseyin Gunerhan; Hepbasli, Arif; Gunerhan, Huseyin; Araz, Mustafa
This study aims at experimentally analysing and assessing the performance of a wastewater source heat pump system (WWSHP) in cooling mode which was installed at Yasar University Izmir Turkey through exergetic and thermoeconomic (exergoeconomic) analysis methods. Within this context first conventional exergy analysis was performed based on the actual experimental data where exergy efficiencies destructions and relative irreversibilities of each element were determined to indicate improvements. Then these results were combined with the cost data of the system to make exergoeconomic analysis. Functional exergy efficiencies of the entire system and the WWSHP were obtained to be 7.56% and 11.77% respectively. The compressor had the biggest relative irreversibility which was followed by the fan-coil. The exergoeconomic factor values of the condenser WW heat exchanger (WWHE) and fan-coil unit were lower than 0.5 indicating that the exergy destruction costs associated with these components were higher than the capital investments. © 2020 Elsevier B.V. All rights reserved.
Citation - WoS: 14
Citation - Scopus: 11
Extended exergy analysis of a novel integrated absorptional cooling system design without utilization of generator for economical and robust provision of higher cooling demands
(Elsevier Ltd, 2024) Aslı Tiktaş; Huseyin Gunerhan; A. Hepbasli; Emin Açıkkalp; Acikkalp, Emin; Tiktas, Asli; Hepbasli, Arif; Gunerhan, Huseyin
The focus of this study is on designing a novel system for the provision of high-capacity cooling and heating loads (4000 kW) with the utilization of absorption technology to increase economic viability and COP value of existing cooling plants via lower-grade waste heat sources (70 °C-90 °C). To achieve this aim in the novel system an integration including the LiBr-water solution based absorptional heat transformer (AHT) and absorptional cooling cycle (ACC) and flat plate solar collector (FPSC) systems was proposed. In the integration the utilization of the generator in the cooling cycle was avoided with the interaction of the high-temperature LiBr-water solution (120 °C-150 °C) from the AHT system and ACC system evaporator. In this way both the additional cost of the boiler and heat source and the enhancement of economic viability and COP value were achieved. Energy economic traditional and extended exergy sustainability and environmental analyses were implemented in this novel system. The COP value for the cooling system was determined to be 3.10 from energy analysis. This result forms a significant indicator for achieving of the main focus of the current study with the proposed novel system. The annual heating and cooling duty generations with this novel system were computed as 52.37 GWh and 52.40 GWh respectively. In the context of economically comparing the proposed system to other plants with similar scale that already exist the initial overall expenditure yearly operational expenses and the time it takes to recover the investment for the proposed system were set at $4.56 million $3.12 million and 1.75 years respectively. It is worth noting though that these figures fall within the range of $6–8 million $5–7 million and 5–10 years respectively for the currently operational plants. This result indicated that the proposed system provides a robust alternative to the existing cooling-heating cogeneration systems in terms of main output generation and is more economically viable. Also the novel system gained annually US$3.89 million in energy costs. The conventional exergy analysis results were summarized by forming an exergy flow and loss diagram namely the Grassmann diagram. In addition in this current study the novel extended exergy flow diagram indicating extended exergy content components energy carriers of the proposed system and exergy product rate streams was also proposed and drawn for the proposed system. © 2024 Elsevier B.V. All rights reserved.
Citation - WoS: 100
Citation - Scopus: 117
Heat exchanger applications in wastewater source heat pumps for buildings: A key review
(ELSEVIER SCIENCE SA, 2015) Oguzhan Culha; Huseyin Gunerhan; Emrah Biyik; Orhan Ekren; Arif Hepbasli; Culha, Oguzhan; Ekren, Orhan; Hepbasli, Arif; Gunerhan, Huseyin; Biyik, Emrah
Wastewater heat recovery applications are becoming widespread in energy saving applications. A sustainable and low emissions operation in air conditioning and heating processes is achieved by harvesting the otherwise wasted energy in wastewater through specially designed heat exchangers lying at the core of heat pumps. This combined system is called wastewater source heat pump. In this study a review of wastewater heat exchangers in wastewater source heat pump applications is presented and wastewater heat exchangers are classified in detail based on multiple features including utilization and construction methodology. Also the potential of wastewater types of wastewater source heat pumps and their applications are briefly discussed. (C) 2015 Elsevier B.V. All rights reserved.
Citation - WoS: 6
Citation - Scopus: 7
Humidifying solar collector for improving the performance of direct solar desalination systems: A theoretical approach
(PERGAMON-ELSEVIER SCIENCE LTD, 2022) Harris J. N. Welepe; Huseyin Gunerhan; Levent Bilir; Bilir, Levent; Gunerhan, Huseyin; Welepe, Harris J. N.
In this paper a new type of solar collector named humidifying solar collector that is a solar collector with air humidification function is proposed. The particularity of this system compared to previous systems in the literature is that the quantity of liquid water present in the collector at each instant is equal to the quantity that will evaporate within the following unit time no longer greater. This minimizes the quantity of liquid water present in the collector at each instant and consequently allows to reach desired evaporation temperatures in shorter times and even under low solar irradiances and minimizes the thermal resistance between evaporation surface and absorber caused by water depth. Then a theoretical and comparative study by simulation using Engineering Equation Solver software between the performance of the humidifying solar collector-based solar still (proposed system) and that of the solar air heater-based humidification dehumidification solar desalination system (conventional system) is conducted. The performance parameters assessed are energy and exergy effi-ciencies dry air mass flow rate required and the maximum water mass flow rate that can evaporate in that air. The results reveal that in general case the proposed system is fundamentally more efficient than the conven-tional system. For instance for the sizes and heat transfer parameters chosen in this study the performance of the proposed system is 1.3-32.2 times higher than that of the conventional system, its freshwater productivity under incident solar irradiance of 900 W/m2 can reach 2.923 kg/h and can be further improved by optimizing the design of the humidifying solar collector.
Nanoakışkan Kullanılan Sıvı Akışkanlı Güneş Kolektörlerinin Enerji Verimliliği Açısından Karşılaştırılması
(2023) Hepbasli, Arif; Gunerhan, Huseyin; Kesen, Fırat
In this study, the effects of nanofluids on the energy efficiency of collectors in solar collectors using nanofluids were evaluated. The evaluation was made by considering factors such as different nanofluid types, sizes, concentrations and surfactant usage. The study includes a comprehensive literature study. The effects of nanofluids on the efficiency of the flat-plane collector and parabolic collector are presented in detail in the tables. It has been observed that a significant improvement in energy efficiency can be achieved by using nanofluids with very high thermal conductivity capacity and consequently the ability to increase efficiency instead of standard liquids used in collectors. In this study, it was emphasized that, depending on the detailed research results, it is possible to achieve energy efficiency increases of up to 95% in collector efficiency with the use of appropriate nanofluid.