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Every technology and anthropogenic activity affects the environment. This even applies to renewable, green energy forms, such as geothermal energy, which are often labelled as being climate neutral. Yet, a second glance reveals that this is not the case, as the construction, operation and decommissioning of geothermal power plants implies a consumption of materials and energy. Life Cycle Assessments (LCA) help to identify and quantify these impacts in order to ensure realistic comparability at different levels. Despite a growing number of surveys, however, either not all influencing parameters are explicitly considered, or the studies are only theoretical and based on generic data. Therefore, this study explores the binary plant of Kirchstockach located in Southern Germany in a comprehensive LCA. Corresponding scenarios identify leakages of used refrigerants and allocations of energy consumption during construction and operation as relevant impact factors. Results show that using refrigerants with low global warming potential ensures minimal effects even in case of larger losses. In addition, resource-saving drilling with electricity instead of diesel can effectively offset energy needs by later electricity production. In contrast, auxiliary energy usage from an electricity grid dominated by fossil sources has highly negative effects on the environmental performance.
Kathrin Menberg; Florian Heberle; Christoph Bott; Dieter Brüggemann; Peter Bayer. Environmental performance of a geothermal power plant using a hydrothermal resource in the Southern German Molasse Basin. Renewable Energy 2020, 167, 20 -31.
AMA StyleKathrin Menberg, Florian Heberle, Christoph Bott, Dieter Brüggemann, Peter Bayer. Environmental performance of a geothermal power plant using a hydrothermal resource in the Southern German Molasse Basin. Renewable Energy. 2020; 167 ():20-31.
Chicago/Turabian StyleKathrin Menberg; Florian Heberle; Christoph Bott; Dieter Brüggemann; Peter Bayer. 2020. "Environmental performance of a geothermal power plant using a hydrothermal resource in the Southern German Molasse Basin." Renewable Energy 167, no. : 20-31.
This article presents a 125-day experiment to investigate model predictive heat pump control. The experiment was performed in two parallel operated systems with identical components during the heating season. One of the systems was operated by a standard controller and thus represented a reference to evaluate the model predictive control. Both test rigs were heated by an air-source heat pump which is influenced by real weather conditions. A single-family house model depending on weather measurement data ensured a realistic heat consumption in the test rigs. The adapted model predictive control algorithm aimed to minimize the operational costs of the heat pump. The evaluation of the measurement results showed that the electrical energy demand of the heat pump can be reduced and the coefficient of performance can be increased by applying the model predictive controller. Furthermore, the self-consumption of photovoltaic electricity, which is calculated by means of a photovoltaic model and global radiation measurement data, was more than doubled. Consequently, the energy costs of heat pump operation were reduced by 9.0% in comparison to the reference and assuming German energy prices. The results were further compared to the scientific literature and short-term measurements were performed with the same experimental setup. The dependence of the measurement results on the weather conditions and the weather forecasting quality are shown. It was found that the duration of experiments should be as long as possible for a comprehensive evaluation of the model predictive control potential.
Sebastian Kuboth; Theresa Weith; Florian Heberle; Matthias Welzl; Dieter Brüggemann. Experimental Long-Term Investigation of Model Predictive Heat Pump Control in Residential Buildings with Photovoltaic Power Generation. Energies 2020, 13, 6016 .
AMA StyleSebastian Kuboth, Theresa Weith, Florian Heberle, Matthias Welzl, Dieter Brüggemann. Experimental Long-Term Investigation of Model Predictive Heat Pump Control in Residential Buildings with Photovoltaic Power Generation. Energies. 2020; 13 (22):6016.
Chicago/Turabian StyleSebastian Kuboth; Theresa Weith; Florian Heberle; Matthias Welzl; Dieter Brüggemann. 2020. "Experimental Long-Term Investigation of Model Predictive Heat Pump Control in Residential Buildings with Photovoltaic Power Generation." Energies 13, no. 22: 6016.
The difference in heating or cooling to power ratio between required demands for district networks and the proposed tri-generation system is the most challenging issue of the system configuration and design. In this work, an adjustable, novel tri-generation system driven by geothermal resources is proposed to supply the thermal energies of a specific district network depending on ambient temperature in Germany. The tri-generation system is a combination of a modified absorption refrigeration cycle and a Kalina cycle using NH3-H2O mixture as a working fluid for the whole tri-generation system. A sensitive analysis of off-design conditions is carried out to study the effect of operational parameters on the system performances prior to optimizing its performance. The simulation show that the system is able to cover required heating and cooling demands. The optimization is applied considering the maximum exergy efficiency (scenario 1) and minimum total exergy destruction rate (scenario 2). The optimization results show that the maximum mean exergy efficiency in scenario 1 is achieved as 44.67% at the expense of 14.52% increase in the total exergy destruction rate in scenario 2. The minimum mean total exergy destruction rate in scenario 2 is calculated as 2980 kW at the expense of 8.32% decrease in the exergy efficiency in scenario 1.
Mehri Akbari Kordlar; Florian Heberle; Dieter Brüggemann. Evaluation and Optimization of the Annual Performance of a Novel Tri-Generation System Driven by Geothermal Brine in Off-Design Conditions. Applied Sciences 2020, 10, 6532 .
AMA StyleMehri Akbari Kordlar, Florian Heberle, Dieter Brüggemann. Evaluation and Optimization of the Annual Performance of a Novel Tri-Generation System Driven by Geothermal Brine in Off-Design Conditions. Applied Sciences. 2020; 10 (18):6532.
Chicago/Turabian StyleMehri Akbari Kordlar; Florian Heberle; Dieter Brüggemann. 2020. "Evaluation and Optimization of the Annual Performance of a Novel Tri-Generation System Driven by Geothermal Brine in Off-Design Conditions." Applied Sciences 10, no. 18: 6532.
Towards the introduction of environmentally friendlier refrigerants, CO2 cycles have gained significant attention in cooling and air conditioning systems in recent years. In this context, a design procedure for an air finned-tube CO2 gas cooler is developed. The analysis aims to evaluate the gas cooler design incorporated into a CO2 air conditioning system for residential applications. Therefore, a simulation model of the gas cooler is developed and validated experimentally by comparing its overall heat transfer coefficient. Based on the model, the evaluation of different numbers of rows, lengths, and diameters of tubes, as well as different ambient temperatures, are conducted, identifying the most suitable design in terms of pressure losses and required heat exchange area for selected operational conditions. The comparison between the model and the experimental results showed a satisfactory convergence for fan frequencies from 50 to 80 Hz. The absolute average deviations of the overall heat transfer coefficient for fan frequencies from 60 to 80 Hz were approximately 10%. With respect to the gas cooler design, a compromise between the bundle area and the refrigerant pressure drop was necessary, resulting in a 2.11 m2 bundle area and 0.23 bar refrigerant pressure drop. In addition, the analysis of the gas cooler’s performance in different ambient temperatures showed that the defined heat exchanger operates properly, compared to other potential gas cooler designs.
Charalampos Alexopoulos; Osama Aljolani; Florian Heberle; Tryfon C. Roumpedakis; Dieter Brüggemann; Sotirios Karellas. Design Evaluation for a Finned-Tube CO2 Gas Cooler in Residential Applications. Energies 2020, 13, 2428 .
AMA StyleCharalampos Alexopoulos, Osama Aljolani, Florian Heberle, Tryfon C. Roumpedakis, Dieter Brüggemann, Sotirios Karellas. Design Evaluation for a Finned-Tube CO2 Gas Cooler in Residential Applications. Energies. 2020; 13 (10):2428.
Chicago/Turabian StyleCharalampos Alexopoulos; Osama Aljolani; Florian Heberle; Tryfon C. Roumpedakis; Dieter Brüggemann; Sotirios Karellas. 2020. "Design Evaluation for a Finned-Tube CO2 Gas Cooler in Residential Applications." Energies 13, no. 10: 2428.
In Germany, enhancing renewable power generation represents a leading step to comply with the requirements of the Energiewende agenda. The geothermal reservoir in Oberhaching is assumed as a case study, with a gross electric power equal to 4.3 MWel. The intent of this work is to design a hybrid binary geothermal power plant and to integrate it into the German energy market. Biogas waste thermal power equal to 1350 kWth is assumed as a secondary source. Two different layouts are defined for the hybrid solution: increasing the geothermal fluid temperature before entering the organic Rankine cycle (ORC) unit and superheating the working fluid after the evaporator. Stationary and quasi-stationary simulations have been performed with Aspen Plus V8.8. Results demonstrate how hybridization allows a maximum electric power increase of about 240 kWel. Off-design conditions are investigated regarding both the switch-off of exhaust gases and the annual ambient temperature fluctuations. In spite of the additional secondary source, the selected case studies cannot comply with the Minute reserve requirements (MRL). Moreover, economic results for both power-only and combined heat and power (CHP) configuration are provided. In the power-only configuration, the new-build hybrid system provides 15.42 €ct/kWh as levelized cost of electricity (LCOE), slightly lower than 16.4 €ct/kWh, as calculated in the geothermal-only solution. A CHP hybrid configuration shows a +19.22% increase in net cash flow at the end of the investment on the CHP geothermal solution.
Davide Toselli; Florian Heberle; Dieter Brüggemann. Techno-Economic Analysis of Hybrid Binary Cycles with Geothermal Energy and Biogas Waste Heat Recovery. Energies 2019, 12, 1969 .
AMA StyleDavide Toselli, Florian Heberle, Dieter Brüggemann. Techno-Economic Analysis of Hybrid Binary Cycles with Geothermal Energy and Biogas Waste Heat Recovery. Energies. 2019; 12 (10):1969.
Chicago/Turabian StyleDavide Toselli; Florian Heberle; Dieter Brüggemann. 2019. "Techno-Economic Analysis of Hybrid Binary Cycles with Geothermal Energy and Biogas Waste Heat Recovery." Energies 12, no. 10: 1969.
Geothermal power plants based on the organic Rankine cycle (ORC) are used to convert the thermal power of brine into electricity. The efficiency and profitability of these power plants can be increased by an additional heat supply. The purpose of this study is to evaluate different combined heat and power (CHP) concepts for geothermal applications by thermodynamic and economic considerations. Therefore, a dynamic simulation model of a double-stage ORC is developed to perform annual return simulations. The transient ORC model is validated in a wide range by operational data of an existing power plant in the German Molasse Basin. A district heating system is considered and the corresponding heat load profiles are derived from a real geothermal driven heating network. For CHP, parallel and combined configurations are considered. The validation of the transient model is satisfying with a correlation coefficient of 0.99 between the simulation and real power plant data. The results show that additional heat extraction leads to a higher exergetic efficiency and a higher profitability. The exergetic efficiency and the profitability are increased by up to 7.9% and 16.1%, respectively. The combined concept shows a slightly better performance than the parallel configuration. The efficiency can be increased by up to 1.3%. In economic terms, for CHP the annual return can be increased by at least 2,500,000 €. In principle, the dynamic model shows reliable results for high power gradients. This enables an investigation of geothermal ORC models for the reserve market in future works.
Tim Eller; Florian Heberle; Dieter Brüggemann. Transient Simulation of Geothermal Combined Heat and Power Generation for a Resilient Energetic and Economic Evaluation. Energies 2019, 12, 894 .
AMA StyleTim Eller, Florian Heberle, Dieter Brüggemann. Transient Simulation of Geothermal Combined Heat and Power Generation for a Resilient Energetic and Economic Evaluation. Energies. 2019; 12 (5):894.
Chicago/Turabian StyleTim Eller; Florian Heberle; Dieter Brüggemann. 2019. "Transient Simulation of Geothermal Combined Heat and Power Generation for a Resilient Energetic and Economic Evaluation." Energies 12, no. 5: 894.
Florian Heberle; Markus Hofer; Nicolas Ürlings; Hartwig Schröder; Thomas Anderlohr; Dieter Brüggemann. Techno-economic analysis of a solar thermal retrofit for an air-cooled geothermal Organic Rankine Cycle power plant. Renewable Energy 2017, 113, 494 -502.
AMA StyleFlorian Heberle, Markus Hofer, Nicolas Ürlings, Hartwig Schröder, Thomas Anderlohr, Dieter Brüggemann. Techno-economic analysis of a solar thermal retrofit for an air-cooled geothermal Organic Rankine Cycle power plant. Renewable Energy. 2017; 113 ():494-502.
Chicago/Turabian StyleFlorian Heberle; Markus Hofer; Nicolas Ürlings; Hartwig Schröder; Thomas Anderlohr; Dieter Brüggemann. 2017. "Techno-economic analysis of a solar thermal retrofit for an air-cooled geothermal Organic Rankine Cycle power plant." Renewable Energy 113, no. : 494-502.
Ivanka Milcheva; Florian Heberle; Dieter Brüggemann. Modeling and simulation of a shell-and-tube heat exchanger for Organic Rankine Cycle systems with double-segmental baffles by adapting the Bell-Delaware method. Applied Thermal Engineering 2017, 126, 507 -517.
AMA StyleIvanka Milcheva, Florian Heberle, Dieter Brüggemann. Modeling and simulation of a shell-and-tube heat exchanger for Organic Rankine Cycle systems with double-segmental baffles by adapting the Bell-Delaware method. Applied Thermal Engineering. 2017; 126 ():507-517.
Chicago/Turabian StyleIvanka Milcheva; Florian Heberle; Dieter Brüggemann. 2017. "Modeling and simulation of a shell-and-tube heat exchanger for Organic Rankine Cycle systems with double-segmental baffles by adapting the Bell-Delaware method." Applied Thermal Engineering 126, no. : 507-517.
Florian Heberle; Markus Hofer; Dieter Brüggemann. A Retrofit for Geothermal Organic Rankine Cycles based on Concentrated Solar Thermal Systems. Energy Procedia 2017, 129, 692 -699.
AMA StyleFlorian Heberle, Markus Hofer, Dieter Brüggemann. A Retrofit for Geothermal Organic Rankine Cycles based on Concentrated Solar Thermal Systems. Energy Procedia. 2017; 129 ():692-699.
Chicago/Turabian StyleFlorian Heberle; Markus Hofer; Dieter Brüggemann. 2017. "A Retrofit for Geothermal Organic Rankine Cycles based on Concentrated Solar Thermal Systems." Energy Procedia 129, no. : 692-699.
Matthias Welzl; Florian Heberle; Dieter Brüggemann. Simultaneous experimental investigation of nucleate boiling heat transfer and power output in ORC using R245fa and R1233zd(E). Energy Procedia 2017, 129, 435 -442.
AMA StyleMatthias Welzl, Florian Heberle, Dieter Brüggemann. Simultaneous experimental investigation of nucleate boiling heat transfer and power output in ORC using R245fa and R1233zd(E). Energy Procedia. 2017; 129 ():435-442.
Chicago/Turabian StyleMatthias Welzl; Florian Heberle; Dieter Brüggemann. 2017. "Simultaneous experimental investigation of nucleate boiling heat transfer and power output in ORC using R245fa and R1233zd(E)." Energy Procedia 129, no. : 435-442.
Tim Eller; Florian Heberle; Dieter Brüggemann. Techno-economic analysis of novel working fluid pairs for the Kalina cycle. Energy Procedia 2017, 129, 113 -120.
AMA StyleTim Eller, Florian Heberle, Dieter Brüggemann. Techno-economic analysis of novel working fluid pairs for the Kalina cycle. Energy Procedia. 2017; 129 ():113-120.
Chicago/Turabian StyleTim Eller; Florian Heberle; Dieter Brüggemann. 2017. "Techno-economic analysis of novel working fluid pairs for the Kalina cycle." Energy Procedia 129, no. : 113-120.
Tim Eller; Florian Heberle; Dieter Brüggemann. Second law analysis of novel working fluid pairs for waste heat recovery by the Kalina cycle. Energy 2017, 119, 188 -198.
AMA StyleTim Eller, Florian Heberle, Dieter Brüggemann. Second law analysis of novel working fluid pairs for waste heat recovery by the Kalina cycle. Energy. 2017; 119 ():188-198.
Chicago/Turabian StyleTim Eller; Florian Heberle; Dieter Brüggemann. 2017. "Second law analysis of novel working fluid pairs for waste heat recovery by the Kalina cycle." Energy 119, no. : 188-198.
Florian Heberle; Christopher Schifflechner; Dieter Brüggemann. Life cycle assessment of Organic Rankine Cycles for geothermal power generation considering low-GWP working fluids. Geothermics 2016, 64, 392 -400.
AMA StyleFlorian Heberle, Christopher Schifflechner, Dieter Brüggemann. Life cycle assessment of Organic Rankine Cycles for geothermal power generation considering low-GWP working fluids. Geothermics. 2016; 64 ():392-400.
Chicago/Turabian StyleFlorian Heberle; Christopher Schifflechner; Dieter Brüggemann. 2016. "Life cycle assessment of Organic Rankine Cycles for geothermal power generation considering low-GWP working fluids." Geothermics 64, no. : 392-400.
We present a thermo-economic analysis of an Organic Rankine Cycle (ORC) for waste heat recovery. A case study for a heat source temperature of 150 °C and a subcritical, saturated cycle is performed. As working fluids R245fa, isobutane, isopentane, and the mixture of isobutane and isopentane are considered. The minimal temperature difference in the evaporator and the condenser, as well as the mixture composition are chosen as variables in order to identify the most suitable working fluid in combination with optimal process parameters under thermo-economic criteria. In general, the results show that cost-effective systems have a high minimal temperature difference ΔTPP,C at the pinch-point of the condenser and a low minimal temperature difference ΔTPP,E at the pinch-point of the evaporator. Choosing isobutane as the working fluid leads to the lowest costs per unit exergy with 52.0 €/GJ (ΔTPP,E = 1.2 K; ΔTPP,C = 14 K). Considering the major components of the ORC, specific costs range between 1150 €/kW and 2250 €/kW. For the zeotropic mixture, a mole fraction of 90% isobutane leads to the lowest specific costs per unit exergy. A further analysis of the ORC system using isobutane shows high sensitivity of the costs per unit exergy for the selected cost estimation methods and for the isentropic efficiency of the turbine.
Florian Heberle; Dieter Brüggemann. Thermo-Economic Analysis of Zeotropic Mixtures and Pure Working Fluids in Organic Rankine Cycles for Waste Heat Recovery. Energies 2016, 9, 226 .
AMA StyleFlorian Heberle, Dieter Brüggemann. Thermo-Economic Analysis of Zeotropic Mixtures and Pure Working Fluids in Organic Rankine Cycles for Waste Heat Recovery. Energies. 2016; 9 (4):226.
Chicago/Turabian StyleFlorian Heberle; Dieter Brüggemann. 2016. "Thermo-Economic Analysis of Zeotropic Mixtures and Pure Working Fluids in Organic Rankine Cycles for Waste Heat Recovery." Energies 9, no. 4: 226.
We present a thermo-economic evaluation of binary power plants based on the Organic Rankine Cycle (ORC) for geothermal power generation. The focus of this study is to analyse if an efficiency increase by using zeotropic mixtures as working fluid overcompensates additional requirements regarding the major power plant components. The optimization approach is compared to systems with pure media. Based on process simulations, heat exchange equipment is designed and cost estimations are performed. For heat source temperatures between 100 and 180 °C selected zeotropic mixtures lead to an increase in second law efficiency of up to 20.6% compared to pure fluids. Especially for temperatures about 160 °C, mixtures like propane/isobutane, isobutane/isopentane, or R227ea/R245fa show lower electricity generation costs compared to the most efficient pure fluid. In case of a geothermal fluid temperature of 120 °C, R227ea and propane/isobutane are cost-efficient working fluids. The uncertainties regarding fluid properties of zeotropic mixtures, mainly affect the heat exchange surface. However, the influence on the determined economic parameter is marginal. In general, zeotropic mixtures are a promising approach to improve the economics of geothermal ORC systems. Additionally, the use of mixtures increases the spectrum of potential working fluids, which is important in context of present and future legal requirements considering fluorinated refrigerants.
Florian Heberle; Dieter Brüggemann. Thermo-Economic Evaluation of Organic Rankine Cycles for Geothermal Power Generation Using Zeotropic Mixtures. Energies 2015, 8, 2097 -2124.
AMA StyleFlorian Heberle, Dieter Brüggemann. Thermo-Economic Evaluation of Organic Rankine Cycles for Geothermal Power Generation Using Zeotropic Mixtures. Energies. 2015; 8 (3):2097-2124.
Chicago/Turabian StyleFlorian Heberle; Dieter Brüggemann. 2015. "Thermo-Economic Evaluation of Organic Rankine Cycles for Geothermal Power Generation Using Zeotropic Mixtures." Energies 8, no. 3: 2097-2124.
The application of the Organic Rankine Cycle to high temperature heat sources is investigated on the case study of waste heat recovery from a selected biogas plant. Two different modes of operation are distinguished: pure electric power and combined heat and power generation. The siloxanes hexamethyldisiloxane (MM) and octamethyltrisiloxane (MDM) are chosen as working fluids. Moreover, the effect of using mixtures of these components is analysed. Regarding pure electricity generation, process simulations using the simulation tool Aspen Plus show an increase in second law efficiency of 1.3% in case of 97/03 wt % MM/MDM-mixture, whereas for the combined heat and power mode a 60/40 wt % MM/MDM-mixture yields the highest efficiency with an increase of nearly 3% compared to most efficient pure fluid. Next to thermodynamic analysis, measurements of heat transfer coefficients of these siloxanes as well as their mixtures are conducted and Kandlikar’s correlation is chosen to describe the results. Based on that, heat exchanger areas for preheater and evaporator are calculated in order to check whether the poorer heat transfer characteristics of mixtures devalue their efficiency benefit due to increased heat transfer areas. Results show higher heat transfer areas of 0.9% and 14%, respectively, compared to MM.
Theresa Weith; Florian Heberle; Markus Preißinger; Dieter Brüggemann. Performance of Siloxane Mixtures in a High-Temperature Organic Rankine Cycle Considering the Heat Transfer Characteristics during Evaporation. Energies 2014, 7, 5548 -5565.
AMA StyleTheresa Weith, Florian Heberle, Markus Preißinger, Dieter Brüggemann. Performance of Siloxane Mixtures in a High-Temperature Organic Rankine Cycle Considering the Heat Transfer Characteristics during Evaporation. Energies. 2014; 7 (9):5548-5565.
Chicago/Turabian StyleTheresa Weith; Florian Heberle; Markus Preißinger; Dieter Brüggemann. 2014. "Performance of Siloxane Mixtures in a High-Temperature Organic Rankine Cycle Considering the Heat Transfer Characteristics during Evaporation." Energies 7, no. 9: 5548-5565.
Piotr Klonowicz; Florian Heberle; Markus Preißinger; Dieter Brüggemann. Significance of loss correlations in performance prediction of small scale, highly loaded turbine stages working in Organic Rankine Cycles. Energy 2014, 72, 322 -330.
AMA StylePiotr Klonowicz, Florian Heberle, Markus Preißinger, Dieter Brüggemann. Significance of loss correlations in performance prediction of small scale, highly loaded turbine stages working in Organic Rankine Cycles. Energy. 2014; 72 ():322-330.
Chicago/Turabian StylePiotr Klonowicz; Florian Heberle; Markus Preißinger; Dieter Brüggemann. 2014. "Significance of loss correlations in performance prediction of small scale, highly loaded turbine stages working in Organic Rankine Cycles." Energy 72, no. : 322-330.
We present a thermo-economic analysis for a low-temperature Organic Rankine Cycle (ORC) in a combined heat and power generation (CHP) case. For the hybrid power plant, thermal energy input is provided by a geothermal resource coupled with the exhaust gases of a biogas engine. A comparison to alternative geothermal CHP concepts is performed by considering variable parameters like ORC working fluid, supply temperature of the heating network or geothermal water temperature. Second law efficiency as well as economic parameters show that hybrid power plants are more efficient compared to conventional CHP concepts or separate use of the energy sources.
Florian Heberle; Dieter Brüggemann. Thermoeconomic Analysis of Hybrid Power Plant Concepts for Geothermal Combined Heat and Power Generation. Energies 2014, 7, 4482 -4497.
AMA StyleFlorian Heberle, Dieter Brüggemann. Thermoeconomic Analysis of Hybrid Power Plant Concepts for Geothermal Combined Heat and Power Generation. Energies. 2014; 7 (7):4482-4497.
Chicago/Turabian StyleFlorian Heberle; Dieter Brüggemann. 2014. "Thermoeconomic Analysis of Hybrid Power Plant Concepts for Geothermal Combined Heat and Power Generation." Energies 7, no. 7: 4482-4497.
Die Wahl eines geeigneten Kraftwerkssystems in Abhängigkeit der Charakteristika der Ressource ist ein Schlüssel für eine effiziente geothermische Stromerzeugung. Im Fall von Hochenthalpie‐Lagerstätten ist es möglich, das Thermalwasser direkt als Arbeitsmedium zu nutzen. So kann entweder gesättigter Dampf unmittelbar in der Turbine entspannt und genutzt werden oder im Fall eines geförderten Zwei‐Phasen‐Gemisches durch den Einsatz von Flash‐Prozessen. Für Niederenthalpie‐Lagerstätten mit Thermalwassertemperaturen unter 200 °C, wie sie in Deutschland vorliegen, bedarf es binärer Kraftwerke. Hierbei handelt es sich um geschlossene Sekundärprozesse, auf die die thermische Energie des Thermalwassers übertragen wird. Als Kraftwerkstechnologien stehen der Organic Rankine Cycle (ORC) und der Kalina Cycle (KC) zur Verfügung. Diese Prozesse unterscheiden sich sowohl in der Prozessführung als auch in der Wahl des Arbeitsmediums. Neben den bereits umgesetzten Standardkonzepten existiert eine Vielzahl von Optimierungsansätzen, welche unter Berücksichtigung der geologischen Randbedingungen, zu einer signifikanten Effizienzsteigerung führen können.
Dieter Brüggemann; Florian Heberle. Kraftwerkstechnik. Handbuch Tiefe Geothermie 2014, 689 -714.
AMA StyleDieter Brüggemann, Florian Heberle. Kraftwerkstechnik. Handbuch Tiefe Geothermie. 2014; ():689-714.
Chicago/Turabian StyleDieter Brüggemann; Florian Heberle. 2014. "Kraftwerkstechnik." Handbuch Tiefe Geothermie , no. : 689-714.
Exploitation of geothermal sources based on advanced Organic Rankine Cycle (ORC) is studied with respect to energetic, plant-specific and economic aspects. Three natural and five synthetic refrigerants are investigated as pure fluids within a sub- and transcritical ORC. Furthermore, a zeotropic mixture of R227ea/R245fa is analysed under subcritical conditions. It is shown that transcritical ORC is a promising way to optimize geothermal power plants. The gross power can be increased by >15% compared with standard subcritical processes. Economic analysis indicates that transcritical ORC as well as zeotropic mixtures lead to significantly lower payback periods and, even when taking into account higher specific investment costs and higher mean cash flow.
Markus Preißinger; Florian Heberle; Dieter Brüggemann. Advanced Organic Rankine Cycle for geothermal application. International Journal of Low-Carbon Technologies 2013, 8, i62 -i68.
AMA StyleMarkus Preißinger, Florian Heberle, Dieter Brüggemann. Advanced Organic Rankine Cycle for geothermal application. International Journal of Low-Carbon Technologies. 2013; 8 (uppl 1):i62-i68.
Chicago/Turabian StyleMarkus Preißinger; Florian Heberle; Dieter Brüggemann. 2013. "Advanced Organic Rankine Cycle for geothermal application." International Journal of Low-Carbon Technologies 8, no. uppl 1: i62-i68.