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Ceyhun Yilmaz - One of the best experts on this subject based on the ideXlab platform.

  • a case study exergoeconomic analysis and genetic algorithm optimization of performance of a hydrogen liquefaction cycle assisted by Geothermal absorption precooling cycle
    Renewable Energy, 2018
    Co-Authors: Ceyhun Yilmaz
    Abstract:

    Abstract The present paper deals with the hydrogen liquefaction system with absorption precooling cycle assisted by Geothermal energy is modeled and analyzed as an exergoeconomic. Uses part of the Geothermal Water heat for absorption refrigeration to precool the hydrogen gas and part of the Geothermal Water heat to produce work with a binary Geothermal cycle and use it in a liquefaction cycle. Exergoeconomic optimization procedure is applied using genetic algorithm method to the integrated system. The objective is to minimize the unit cost of hydrogen liquefaction of the composed system. Based on optimization calculations, hydrogen gas can be cooled down to −30 °C in the precooling cycle. The actual work consumption in the hydrogen liquefaction is calculated to be 10.06 kWh/kg LH2. The unit exergetic liquefaction cost of hydrogen is calculated to be 1.114 $/kg LH2 or 9.27 $/GJ, respectively in the optimum case.

  • performance analysis and optimization of a hydrogen liquefaction system assisted by Geothermal absorption precooling refrigeration cycle
    International Journal of Hydrogen Energy, 2018
    Co-Authors: Ceyhun Yilmaz, Önder Kaşka
    Abstract:

    Abstract The present paper deals with the hydrogen liquefaction with absorption precooling cycle assisted by Geothermal Water is modeled and analyzed. Uses Geothermal heat in an absorption refrigeration process to precool the hydrogen gas is liquefied in a liquefaction cycle. High-temperature Geothermal Water using the absorption refrigeration cycle is used to decrease electricity work consumption in the gas liquefaction cycle. The thermoeconomic optimization procedure is applied using the genetic algorithm method to the hydrogen liquefaction system. The objective is to minimize the unit cost of hydrogen liquefaction of the composed system. Based on optimization calculations, hydrogen gas can be cooled down to −30 °C in the precooling cycle. This allows the exergetic cost of hydrogen gas to be reduced to be 20.16 $/GJ (2.42 $/kg LH2). The optimized exergetic cost of liquefied hydrogen is 4.905 $/GJ (1.349 $/kg LH2), respectively.

  • Exergetic cost evaluation of hydrogen production powered by combined flash-binary Geothermal power plant
    International Journal of Hydrogen Energy, 2015
    Co-Authors: Ceyhun Yilmaz, Mehmet Kanoglu, Aysegul Abusoglu
    Abstract:

    A combined flash-binary Geothermal plant and a Water electrolysis unit for hydrogen production are considered and thermodynamic and exergoeconomic analyses of the system are performed. A liquid Geothermal Water resource at 200 °C with a flow rate of 100 kg/s is considered. The power produced in the plant is used for the electrolysis process. The electrolysis Water can be preheated to 70 °C by the Geothermal Water leaving the power plant and hydrogen can be produced at a rate of 0.0498 kg/s. The exergy efficiency of the power plant and the overall system are calculated to be 46.6% and 45.8%, respectively. The unit exergetic cost of electricity from the power plant is 11.1 $/GJ (or 0.0400 $/kWh) and that of the produced hydrogen is 26.1 $/GJ (or 3.14 $/kg H2).

  • thermodynamic evaluation of Geothermal energy powered hydrogen production by pem Water electrolysis
    Energy, 2014
    Co-Authors: Ceyhun Yilmaz, Mehmet Kanoglu
    Abstract:

    Thermodynamic energy and exergy analysis of a PEM Water electrolyzer driven by Geothermal power for hydrogen production is performed. For this purpose, work is produced from a Geothermal resource by means of the organic Rankine cycle; the resulting work is used as a work input for an electrolysis process; and electrolysis Water is preheated by the waste Geothermal Water. The first and second-law based performance parameters are identified for the considered system and the system performance is evaluated. The effects of Geothermal Water and electrolysis temperatures on the amount of hydrogen production are studied and these parameters are found to be proportional to each other. We consider a Geothermal resource at 160 °C available at a rate of 100 kg/s. Under realistic operating conditions, 3810 kW power can be produced in a binary Geothermal power plant. The produced power is used for the electrolysis process. The electrolysis Water can be preheated to 80 °C by the Geothermal Water leaving the power plant and hydrogen can be produced at a rate of 0.0340 kg/s. The energy and exergy efficiencies of the binary Geothermal power plant are 11.4% and 45.1%, respectively. The corresponding efficiencies for the electrolysis system are 64.0% and 61.6%, respectively, and those for the overall system are 6.7% and 23.8%, respectively.

  • thermal design of alkaline Water electrolysis assisted by combined flash binary Geothermal power plant
    ASME 2013 International Mechanical Engineering Congress and Exposition, 2013
    Co-Authors: Mehmet Kanoglu, Ceyhun Yilmaz
    Abstract:

    The purpose of this study is thermoeconomic performance evaluation of alkaline Water hydrogen production assisted by Geothermal energy. In this study energy, exergy and cost balances of combined systems of each component for hydrogen production assisted by Geothermal energy will be written. Exergy of each involved stream will be calculated and the exergetic balance of each subsystem will be assessed, as well as the global system, identifying and quantifying losses. This will allow thermodynamic performances of combined systems and each component. This information will be relevant to optimize the system performance from an economical point of view.We consider a Geothermal resource at 230°C available at a rate of 230 kg/s. Under realistic operating conditions, 21545 kW power can be produced in a power plant. The produced power is used for the electrolysis process. The electrolysis Water can be preheated to 67.6°C by the Geothermal Water leaving the power plant and hydrogen can be produced at a rate of 0.1125 kg/s. Also, combine flash binary Geothermal power plant energy and exergy efficiencies are calculated to be 12.1% and 57.4% at this condition. Electrolysis system energy and exergy efficiencies are calculated to be 71.4% and 60.7% of Geothermal Water temperature at 230°C and Geothermal Water flow rate at 230 kg/s. We evaluated at unit exergetic cost of electricity combined flash binary system is 10.1$/GJ (0.0364 $/kWh) and unit exergetic cost of hydrogen is 34.6$/GJ (4.16 $/kg H2).Copyright © 2013 by ASME

Mehmet Kanoglu - One of the best experts on this subject based on the ideXlab platform.

  • cryogenic energy storage powered by Geothermal energy
    Geothermics, 2019
    Co-Authors: Tugberk Hakan Cetin, Mehmet Kanoglu, Neslihan Yanikomer
    Abstract:

    Abstract Geothermal energy is one of the promising alternatives of power generation suitable for energy storage applications for load shifting operations. Cryogenic energy storage (CES) is an attractive option for energy storage driven by Geothermal power. In this study, thermodynamic assessment of a cryogenic energy storage unit integrated to a single-flash Geothermal power plant is performed and the effect of Geothermal source temperature on the system performance is investigated. Initially, a resource that can supply Geothermal Water at 180 °C at a rate of 100 kg/s is considered. Power generated from the Geothermal plant during off-peak hours is used to produce and store liquefied air. This liquefied air is used to generate power during peak hours using the heat of Geothermal Water. Our analysis indicates that the liquefaction unit consumes 4304 kW power in order to liquefy air for a 6-h charging period. In the discharge mode, the CES unit can produce a net power output of 12,049 kW for a 1-h operation. The flashing pressure is optimized at 255 kPa for which the total power output is 16,100 kW. The round-trip efficiency of the CES unit is determined to be 46.7% while the overall efficiency of the integrated system is 24.4%.

  • thermodynamic analysis and optimization of various power cycles for a Geothermal resource
    Energy Sources Part A-recovery Utilization and Environmental Effects, 2016
    Co-Authors: Ahmet Coskun, Ali Bolatturk, Mehmet Kanoglu
    Abstract:

    ABSTRACTIn this study, Geothermal resources in Kutahya-Simav region having Geothermal Water at a temperature suitable for power generation is considered. The study is aimed to yield the method of the most effective use of the Geothermal resource and a rational thermodynamic comparison of various cycles for a given resource. Maximum first law efficiencies vary between 6.9 to 10.6% while the second law efficiencies vary between 38.5 to 59.3% depending on the cycle considered. The maximum power output, the first law, and the second law efficiencies are obtained for Kalina cycle followed by combined cycle and binary cycle.

  • Exergetic cost evaluation of hydrogen production powered by combined flash-binary Geothermal power plant
    International Journal of Hydrogen Energy, 2015
    Co-Authors: Ceyhun Yilmaz, Mehmet Kanoglu, Aysegul Abusoglu
    Abstract:

    A combined flash-binary Geothermal plant and a Water electrolysis unit for hydrogen production are considered and thermodynamic and exergoeconomic analyses of the system are performed. A liquid Geothermal Water resource at 200 °C with a flow rate of 100 kg/s is considered. The power produced in the plant is used for the electrolysis process. The electrolysis Water can be preheated to 70 °C by the Geothermal Water leaving the power plant and hydrogen can be produced at a rate of 0.0498 kg/s. The exergy efficiency of the power plant and the overall system are calculated to be 46.6% and 45.8%, respectively. The unit exergetic cost of electricity from the power plant is 11.1 $/GJ (or 0.0400 $/kWh) and that of the produced hydrogen is 26.1 $/GJ (or 3.14 $/kg H2).

  • thermodynamic evaluation of Geothermal energy powered hydrogen production by pem Water electrolysis
    Energy, 2014
    Co-Authors: Ceyhun Yilmaz, Mehmet Kanoglu
    Abstract:

    Thermodynamic energy and exergy analysis of a PEM Water electrolyzer driven by Geothermal power for hydrogen production is performed. For this purpose, work is produced from a Geothermal resource by means of the organic Rankine cycle; the resulting work is used as a work input for an electrolysis process; and electrolysis Water is preheated by the waste Geothermal Water. The first and second-law based performance parameters are identified for the considered system and the system performance is evaluated. The effects of Geothermal Water and electrolysis temperatures on the amount of hydrogen production are studied and these parameters are found to be proportional to each other. We consider a Geothermal resource at 160 °C available at a rate of 100 kg/s. Under realistic operating conditions, 3810 kW power can be produced in a binary Geothermal power plant. The produced power is used for the electrolysis process. The electrolysis Water can be preheated to 80 °C by the Geothermal Water leaving the power plant and hydrogen can be produced at a rate of 0.0340 kg/s. The energy and exergy efficiencies of the binary Geothermal power plant are 11.4% and 45.1%, respectively. The corresponding efficiencies for the electrolysis system are 64.0% and 61.6%, respectively, and those for the overall system are 6.7% and 23.8%, respectively.

  • thermal design of alkaline Water electrolysis assisted by combined flash binary Geothermal power plant
    ASME 2013 International Mechanical Engineering Congress and Exposition, 2013
    Co-Authors: Mehmet Kanoglu, Ceyhun Yilmaz
    Abstract:

    The purpose of this study is thermoeconomic performance evaluation of alkaline Water hydrogen production assisted by Geothermal energy. In this study energy, exergy and cost balances of combined systems of each component for hydrogen production assisted by Geothermal energy will be written. Exergy of each involved stream will be calculated and the exergetic balance of each subsystem will be assessed, as well as the global system, identifying and quantifying losses. This will allow thermodynamic performances of combined systems and each component. This information will be relevant to optimize the system performance from an economical point of view.We consider a Geothermal resource at 230°C available at a rate of 230 kg/s. Under realistic operating conditions, 21545 kW power can be produced in a power plant. The produced power is used for the electrolysis process. The electrolysis Water can be preheated to 67.6°C by the Geothermal Water leaving the power plant and hydrogen can be produced at a rate of 0.1125 kg/s. Also, combine flash binary Geothermal power plant energy and exergy efficiencies are calculated to be 12.1% and 57.4% at this condition. Electrolysis system energy and exergy efficiencies are calculated to be 71.4% and 60.7% of Geothermal Water temperature at 230°C and Geothermal Water flow rate at 230 kg/s. We evaluated at unit exergetic cost of electricity combined flash binary system is 10.1$/GJ (0.0364 $/kWh) and unit exergetic cost of hydrogen is 34.6$/GJ (4.16 $/kg H2).Copyright © 2013 by ASME

Tolga Yalcin - One of the best experts on this subject based on the ideXlab platform.

  • climatic parameters and evaluation of energy consumption of the afyon Geothermal district heating system afyon turkey
    Renewable Energy, 2009
    Co-Authors: Omer Yetemen, Tolga Yalcin
    Abstract:

    Afyon Geothermal district heating system (AFJET) provides heating to 4519 residences, covering an area of 513,683m2. Due to limitations in reinjection capacity, Geothermal Waters are released to the Akarcay Stream, detrimentally affecting the environment. Optimum heating load of the system was determined for a given ambient conditions with respect to different outdoor temperatures. Usage of AFJET was found to be higher than the optimum consumption rates. Optimizing the usage of Geothermal Water will decrease operational cost, increase equipment life-span, and reduce environmental pollution.

  • climatic parameters and evaluation of energy consumption of the afyon Geothermal district heating system afyon turkey
    Renewable Energy, 2009
    Co-Authors: Omer Yetemen, Tolga Yalcin
    Abstract:

    Afyon Geothermal district heating system (AFJET) provides heating to 4519 residences, covering an area of 513,683 m 2 . Due to limitations in reinjection capacity, Geothermal Waters are released to the Akarcay Stream, detrimentally affecting the environment. Optimum heating load of the system was determined for a given ambient conditions with respect to different outdoor temperatures. Usage of AFJET was found to be higher than the optimum consumption rates. Optimizing the usage of Geothermal Water will decrease operational cost, increase equipment life-span, and reduce environmental pollution. Published by Elsevier Ltd.

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

  • development of a new solar and Geothermal based combined system for hydrogen production
    Solar Energy, 2016
    Co-Authors: Yusuf Bicer, Ibrahim Dincer
    Abstract:

    Abstract A new combined system, using solar and Geothermal resources, for hydrogen production, along with power generation, cooling and heating, is proposed and analyzed for practical applications. This combined renewable energy system consists of solar PV/T modules for heating, Water heating and hydrogen production purposes and Geothermal energy for electricity, cooling and hydrogen production. Energy and exergy analyses are conducted to assess the performance of the cycle, and the effects of various system parameters on energy and exergy efficiencies of the overall system and its subsystems are also studied. The overall energy and exergy efficiencies of the system can reach up to 10.8% and 46.3% respectively for a Geothermal Water temperature of 210 °C. Furthermore, the effects of varying Geothermal Water temperature and using different type of working fluids on the system performance are investigated.

  • exergoeconomic analysis of the gonen Geothermal district heating system for buildings
    Energy and Buildings, 2009
    Co-Authors: 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.

Jiao Tian - One of the best experts on this subject based on the ideXlab platform.

  • fluid geochemistry and its implications on the role of deep faults in the genesis of high temperature systems in the eastern edge of the qinghai tibet plateau
    Applied Geochemistry, 2021
    Co-Authors: Jiao Tian, Zhonghe Pang, Dawei Liao, Xiaocheng Zhou
    Abstract:

    Abstract Deep faults could provide fluent channels for Geothermal Water uplift so that it is one of the targets for high-temperature hydrothermal exploration in orogenic Geothermal belt. In the eastern edge of the Qinghai Tibet Plateau, significant Geothermal potential reflected by hot springs, fumaroles, and sinters, are indeed exposed along a series of lithospheric-scale faults, including the Jinshajiang, the Ganzi-Litang and the Xianshuihe faults. However, as the controlling fault of the eastern edge of the plateau, the Longmenshan Fault has few Geothermal manifestations. In order to uncover the role of deep faults in the genesis of high-temperature Geothermal systems, a comprehensive chemical and isotopic comparison of Geothermal fluid between the Xianshuihe-Anninghe Fault and the Longmenshan-Minjiang Fault was investigated in this paper. According to FixAl modeling and cation geothermometric calculations, the reservoir temperatures of Geothermal systems along the Longmenshan Fault are lower than 150 °C with circulation depth of Geothermal Water less than 4 km while those in the Xianshuihe Fault reaches up to 260 °C with Geothermal Water circulating as deep as 8 km. Compared to the Xianshuihe Fault, the low reservoir temperatures along the Longmenshan Fault are accompanied by two characteristics of Geothermal fluid: (1) no distinctive oxygen shift occurs in stable isotopes of Geothermal Waters; and (2) little mantle-derived volatiles found in the gaseous components. We propose that, extensional fracture systems are locally formed in the strike-slip movement of the Xianshuihe and Anninghe faults, which not only act as conduits for deep-derived Geothermal volatiles, such as metamorphic carbon dioxide and mantle helium, but also enhance the heat convection processes, resulting in the formation of high-temperature Geothermal systems. In contrast, in the Longmenshan Thrust Fault, the shallow circulation of Geothermal Water in closed fracture systems accounts for its lower reservoir temperatures. Therefore, deep extensional fault is a crucial element in forming a high-temperature Geothermal system in the eastern edge of the Qinghai Tibet Plateau.

  • fluid geochemistry of the cuopu high temperature Geothermal system in the eastern himalayan syntaxis with implication on its genesis
    Applied Geochemistry, 2019
    Co-Authors: Jiao Tian, Zhonghe Pang, Yingchun Wang
    Abstract:

    Abstract High-temperature Geothermal fluids dissolve constituents pertinent to Water-rock interaction and magmatic volatile absorption, resulting in high total dissolved solid (TDS) values. However, this study focuses on the hydrochemical evolution of the low-salinity HCO3–Na type high-temperature Geothermal fluid in Cuopu, eastern Himalayas. The Geothermal Water is recharged by local precipitation and glacier Water from surrounding mountains. The TDS values are below 834 mg/L and the constituents are mainly products of the Water-carbon dioxide-rock interactions lacking magmatic volatile dissolved in the fluid. The Geothermal Water reaches an almost complete chemical equilibrium with the feldspar or plagioclase-enriched reservoir rock in a reducing condition. The reservoir temperature is between 175 °C–200 °C, while the temperature could reach up to 400 °C in the deep crustas indicated by the carbon isotopic exchange equilibrium between CO2 and CH4. The infiltrated glacier Water was heated during its circulation within the hot thickened crust and continued dissolving the crustal metamorphic gas, such as radiogenic helium and limestone metamorphic CO2, until the junction of the two sets of faults provided an ascending channel for it. Upon rising along the conduit, the Geothermal Water mixed with cold groundWater to different degrees. Approximately 0.015 mol/L CO2 escaped from the Geothermal fluid when it scattered as bubbling hot springs on the surface of the anisotropic porous Quaternary sediments. Such kind ofhydrochemical evolution of lowsalinity alkaline HCO3–Na type Water represents a typical formation mechanism of the high-temperature Geothermal systems along the Himalayas.

  • geochemistry of Geothermal fluids with implications on the sources of Water and heat recharge to the rekeng high temperature Geothermal system in the eastern himalayan syntax
    Geothermics, 2018
    Co-Authors: Jiao Tian, Tianming Huang, Zhonghe Pang, Yingchun Wang, Yanlong Kong
    Abstract:

    Abstract Rekeng Geothermal system in Eastern Himalayan syntax is found to exhibit the strongest surface manifestations in the western Sichuan plateau, with numerous boiling springs, fumeroles and geysers. What is the heat source of such a high temperature system? Is there a magmatic heat source to support it? In this study we have attempted to seek clues from the isotope geochemistry of Geothermal fluids. The stable isotope δ 2 H and δ 18 O composition of Geothermal Water suggests that it is recharged by precipitation and snow melt of the surrounding mountains. The chemical type of the Geothermal Water is alkaline HCO 3 -Na as a result of Water-CO 2 -rock interaction. Geothermal reservoir temperature in the fractured metamorphic rock is estimated to be between 200 °C–225 °C, using the chemical geothermometers and the chemical thermodynamic modeling approach. During the degassing process upon rising, 0.05 mol/L CO 2 has escaped from the Geothermal fluid. Evidence from the relationships among major ions and Geothermal suite (Li, B, F, As) indicate that the hot springs shared the same parent source fluid and they mixed with cold groundWater to different levels in the subsidiary fractures near surface. Carbon isotope signatures show that the CO 2 enriched Geothermal gas is 95% of crustal metamorphic origin. Additionally, based on helium isotope analysis, the mantle magmatic 3 He signatures have been largely obliterated since it accounts for no more than 5%, implying there is no underlying mantle-derived magma chamber acting as heat source. Therefore, a significant portion of heat is likely converted from crustal deformation in view of the regional tectonic background as Eastern Himalayan syntax.

  • fluid geochemistry and geothermometry applications of the kangding high temperature Geothermal system in eastern himalayas
    Applied Geochemistry, 2017
    Co-Authors: Zhonghe Pang, Yingchun Wang, Jiao Tian
    Abstract:

    Abstract High-temperature Geothermal systems hold an enormous capacity for generating Geothermal energy. The Kangding area is a typical high-temperature Geothermal field in the Himalayan Geothermal Belt. Hydrogeochemical, gas geochemical and isotopic investigations were performed to identify and qualify the main hydrogeochemical processes affecting thermal Water composition, including mixing and degassing, and then to estimate a reliable reservoir temperature. Nine Water samples and four Geothermal gas samples were collected and analysed for chemical and isotopic components. The results demonstrate the alkaline deep Geothermal Water is the mixtures of approximately 75% snow-melt Water and 25% magmatic Water. It is enriched in Na, K, F, Li and other trace elements, indicating the granite reservoir nature. The shallow Geothermal Water is the mixtures of approximately 30% upward flow of deep Geothermal Water and 70% meteoric cold Water. High concentrations of Ca, Mg and HCO3 indicate the limestone reservoir nature. There is no remarkable oxygen isotope shift in the Geothermal Water since the rapid circulation is difficult to trigger off strong Water-rock interaction. CO2 is the predominant Geothermal gas, accounting for more than 97% of total gases in volume percentage. The concentration of CO2 degassing ranged from 0.4 mol L−1 to 0.8 mol L−1 via geothermometrical modelling. As a result, the Geothermal Water pH increased from 6.0 to 9.0, and approximately 36% of the total SiO2 re-precipitate. The sources of CO2 are the metamorphism of limestone and magmatic degassing based on the composition of carbon isotope. The appropriate geothermometers of Na-K and Na-Li yield reservoir temperature of 280 °C. The geothermometrical modelling, developed to eliminate the effects of CO2 degassing, yields temperature of 250 °C. The silica-enthalpy mixing model yields temperature of 270 °C with no steam separation before mixing.