Binary Geothermal Power Plant Research Articles

Techno-economic analysis and optimization of a binary geothermal combined district heat and power plant for Puga Valley, India

This article investigates the energy, exergy, and economic performance of a Puga Valley-specific binary geothermal combined district heat and power plant, taking into account geotechnical data and related cost functions. The power plant uses an organic Rankine cycle (ORC) with R123 as the working fluid, utilizing waste heat for district heating to enhance efficiency. Variations in operating and design parameters such as geothermal fluid flow rate, temperature, and ORC temperature of the evaporator and condenser are found to have significant effects on the overall performance of the system and cost rate. A multi-objective grey wolf optimization technique based on artificial neural networks has been used to determine the ideal values of the above-mentioned parameters. The optimization study revealed a Pareto optimal curve with overall exergy efficiency and total cost rate as objective functions from which the optimal point was identified using the technique for order preference by similarity to the ideal solution (TOPSIS) method. While operating the proposed CHP plant at TOPSIS optimal point, the plant delivers a net electrical output of 1.08 MW alongside 4.19 MW of thermal energy, resulting in a total cost rate of 33.84 USD/h, with energy and exergy efficiencies peaking at 32.26 % and 36.8 %, respectively. The exergy analysis at the optimal point also revealed a notable reduction of 550 kW in the total exergy destruction rate compared with the base-case scenario. Furthermore, the design requirements of a 5 MW net power output CHP plant for effective recovery of the Puga Valley geothermal resource are discussed.

Detection of abnormal operation in geothermal binary plant feed pumps using time-series analytics

In this study, we investigate potential pump cavitation events in circulating feed pumps deployed in a geothermal binary power plant using feature-based time series analytics and machine learning. The feed pumps have been in operation for over a decade but have been experiencing episodes wherein the pumps were drawing in lower power even while pump speeds were maintained at the same levels.A workflow combining time-series analytics and first-principle thermodynamics was applied to characterise potential drivers of the abnormal events in the feed pumps. An approach based on systematic time-series feature engineering and semi-supervised machine learning was used to fully annotate the input data and identify twenty (20) undocumented occurrences of the target event. Time-series features extracted from the fully labelled dataset were then used to train forecasting models to identify potential drivers of the target events. Forecasting models trained using pump data outperformed those trained on times-series data from other power plant components (Matthew’s correlation coefficient score of 0.490 vs 0.255). This result indicates that the abnormal events are primarily driven by operating conditions local to the feed pump system. This finding was confirmed by Bayesian A/B testing, showing that the target events were more likely to occur by 22% when four (4) feed pumps were running compared to when only three (3) pumps were in operation. Furthermore, thermodynamic analysis of the state of the working fluid across the feed pumps shows irregularities at the pump inlet, where indications of partial vaporisation of the working fluid have been identified.

Analysis of the cycle arrangement of a binary geothermal power plant using a low- and medium-temperature source

The cycle arrangement of a binary-type GeoPP using a thermal energy source with a temperature of 80 ÷ 150 °C was considered; its elements and structural connections were substantiated. A method was proposed, numerical studies were carried out to find optimal working bodies for the ORC and parameters for the operation of GeoPP in nominal and variable modes. The greatest efficiency and power in the considered modes belongs to the GeoPP operating by the ORC on the R141b freon. Since this freon is prohibited for use as having an ozone-depleting chemical structure, R245fa was selected among the ozone-safe freons considered, for which the electrical power and absolute electrical efficiency of the GeoPP have the best values at a source temperature of 80 ÷ 120 °C. R245ca and R365mfc are the most effective freons for the ORC of GeoPPs at > 120 °C.

Proposal and comprehensive study of an integrated polygeneration process relying on landfill gas, renewable hydrogen, and binary geothermal cycle

Landfill gas (LFG) is an accessible, inexpensive, and carbon-rich source, and due to its methane content, it can also be used as a fuel. In this paper, a novel polygeneration structure is presented that uses LFG as the input fuel as well as geothermal energy to produce valuable products, including electricity, methanol, freshwater, heating, and cooling. The configuration is made of biogas combustion unit, binary geothermal power plant, cooling water production unit, Kalina power cycle, desalination unit, water electrolysis unit, and methanol synthesis and purification unit. The methanol synthesis unit is modified using a scrubbing column, resulting in recovery of methanol without loss. Aspen HYSYS application is used to model this procedure, and it is examined from a 4E (energy, exergy, economic, and environmental) standpoint. The findings show that a total of55.46% of energyand 77.29% of exergy efficienciesare reached. From the environmental standpoint, it is found that the proposed structure has negative emissions, and its carbon dioxide (CO2) footprint is equal to −0.161 kgCO2/kgprod. In addition, the total CO2 emission of 46,780 kg/h is calculated. Concerning the economic aspect, the cost rate of produced methanol, heating, cooling, and freshwater are found at 0.268 $/kgMeOH, 1.01 $/kgLPS, 0.26 $/kgCW, and 0.7 $/kgFW, respectively. Besides, it is concluded that the methanol production cost rate of this model is comparatively lower than the methods such as power-to-methanol and coke oven gas-to-methanol.

CYCLE DIAGRAM OF GEOTHERMAL ENERGY

Link for citation: Yankovsky S.A., Lavrinenko S.V., Tsibulskiy S.A., Yankovskaya N.S., Gamov D.L. Cycle diagram of geothermal energy. Bulletin of the Tomsk Polytechnic University. Geo Аssets Engineering, 2023, vol. 334, no. 7, рр. 122-136. In Rus. The relevance of the research is caused by the need to develop alternative and environmentally friendly energy sources in conditions of global warming. The development of geothermal energy will make it possible to produce thermal and electric energy without emissions of CO2 into the environment and reduce the dependence of the energy sector on hydrocarbon raw materials. The main aim of this study is a comprehensive analysis of the features of geothermal power plants, including the existing technologies for converting geothermal energy to provide consumers of electric and thermal energy. Objects: diagrams of geothermal power plants operating in different geographical and climatic conditions, as well as their working fluids. Methods: analytical review of thematic publications using the materials of the databases of the RSCI, Scopus and Web of Science, a comparative analysis of the effectiveness of geothermal power plants for various indicators. Results. Currently, there are about 400 geothermal power plants in the world. The active development of geothermal energy is caused by environmental friendliness, low cost of energy produced, minimal operating costs, lack of dependence on atmospheric influences, and the absence of the need to burn fuel, etc. At the same time, most of the world's geothermal power plants use the energy of a geothermal source with a water temperature of 100–200 °C. Among the main thermodynamic cycles and thermal schemes implemented, it is possible to single out direct cycle geothermal power plants with one-stage and two-stage separation of a geothermal source, with direct supply of dry steam to the turbine, binary and combined versions. The analysis shows that direct cycle geothermal power plants have the lowest cost of installed electrical power due to the relative simplicity and high thermal efficiency, but require high parameters of a geothermal source. On the other hand, binary geothermal power plants have the highest unit cost, but can be implemented on geothermal sources with relatively low water parameters, which was the main reason for their greatest spread in the world. At the same time, the implementation of a binary geothermal power plant with a Organic Rankine сycle has a number of advantages compared to the thermodynamic cycles of Kalina, Stirling and Brighton, among which the main ones are relative ease of adaptation and application, as well as low maintenance costs.

Advanced Exergoeconomic Assessment of CO2 Emissions, Geo-Fluid and Electricity in Dual Loop Geothermal Power Plant

Binary geothermal power plants (GPPs) are mostly encountered in geothermal fields with medium and low temperatures. The design and operation of dual binary GPPs can be difficult due to the geothermal fluid properties. This affects their performance and feasibility. Thermoeconomics are essential elements for the design and operation of the GPPs. In this study, advanced exergoeconomic analysis is applied to a true dual binary GPP (as a case study) to further evaluate it from performance and economic perspectives. In analysis, the specific exergy cost (SPECO) method is used. Then, some specific indicators are presented to evaluate the performance and economics of the GPP. Thus, technical and economic solutions have been developed in the design and operation stages through the analysis. The results of the study indicated that the total operating cost of 1218 USD/h could be reduced to 186 USD/h by improving the operating conditions. This corresponds to an 85% decrease. The cost per electricity generated, cost per geothermal energy input, and cost per CO2 emission of the GPP are determined as 0.049 USD/kWh, 5.3 USD/GJ, and 0.13 USD/kg, respectively. As a result, while the savings potential of the GPP is 15%, it can result in a 15% reduction in CO2 emission cost.

Techno-economic evaluation and multi-criteria optimization of a trigeneration flash–binary geothermal power plant integrated with parabolic trough solar collectors

Techno-economic evaluation and multi-criteria optimization of a trigeneration flash–binary geothermal power plant integrated with parabolic trough solar collectors

Thermodynamic and economic evaluation and optimization of the applicability of integrating an innovative multi-heat recovery with a dual-flash binary geothermal power plant

Thermodynamic and economic evaluation and optimization of the applicability of integrating an innovative multi-heat recovery with a dual-flash binary geothermal power plant

Thermodynamic re-assessment of a geothermal binary power plant operated in a moderate-temperature geothermal field

Thermodynamic re-assessment of a geothermal binary power plant operated in a moderate-temperature geothermal field

Thermodynamic re-assessment of a geothermal binary power plant operated in a moderate-temperature geothermal field

Thermodynamic re-assessment of a geothermal binary power plant operated in a moderate-temperature geothermal field

4E Assessment of an Organic Rankine Cycle (ORC) Activated with Waste Heat of a Flash-Binary Geothermal Power Plant.

In this paper, the 4E assessment (Energetic, Exergetic, Exergoeconomic and Exergoenvironmental) of a low-temperature ORC activated by two different alternatives is presented. The first alternative (S1) contemplates the activation of the ORC through the recovery of waste heat from a flash-binary geothermal power plant. The second alternative (S2) contemplates the activation of the ORC using direct heat from a geothermal well. For both alternatives, the energetic and exergetic models were established. At the same time, the economic and environmental impact models were developed. Finally, based on the combination of the exergy concepts and the economic and ecological indicators, the exergoeconomic and exergoenvironmental performances of the ORC were obtained. The results show higher economic, exergoeconomic and exergoenvironmental profitability for S1. Besides, for the alternative S1, the ORC cycle has an acceptable economic profitability for a net power of 358.4 kW at a temperature of 110 °C, while for S2, this profitability starts being attractive for a power 2.65 times greater than S1 and with a temperature higher than 135 °C. In conclusion, the above represents an area of opportunity and a considerable advantage for the implementation of the ORC in the recovery of waste heat from flash-binary geothermal power plants.

ORC fluids selection for a bottoming binary geothermal power plant integrated with a CSP plant

Hybridization of geothermal power plants with concentrating solar power systems is an attractive solution to enhance the dispatch capacity of thermal power plants. Hence, the design and thermo-economic analyses of a combined solar-geothermal power plant with different organic fluids have been investigated. This configuration generates electricity at two temperature levels; high one at a topping parabolic trough solar power plant, and low one at a bottoming binary geothermal plant. The topping solar plant is equipped with energy storage and fuel backup systems simultaneously to maximize the generated power. Furthermore, the bottoming geothermal plant has been analyzed with nine different organic fluids.The obtained results show that power generation of this configuration has been raised by more than 19.36% at nominal conditions compared to the reference stand-alone solar plant. Moreover, organic fluids with wet behavior show better performances than those with dry one. In this regard, ammonia, R32, R290, and R143a are more efficient than the others, where annual net outputs of 22.20, 20.02, 19.25, and 18.67 GWhe have been produced, respectively. Furthermore, the combined plant with ammonia as the working fluid in the bottoming installation has the lowest levelized cost of electricity with a value of 10.42 ¢/kWh.

Thermodynamic, environmental, and exergoeconomic feasibility analyses and optimization of biomass gasifier-solid oxide fuel cell boosting a doable-flash binary geothermal cycle; a novel trigeneration plant

Heat recovery boosting applications, especially polygeneration, provide an efficacious effort toward sustainable energy supply, air pollution control, and financial saving. Among new technologies, solid oxide fuel cells are able to effectively operate benefiting from high-temperature syngas output to boost the applicability of combined cycles. Respecting this manner and embracing a renewable energy resource, i.e., biomass fuel, a biomass Gasifier-Solid oxide fuel cell is devised in this paper; its waste heat is recovered by a doable-flash binary geothermal power plant for better operation. Accordingly, a thermal-based desalination, namely humidification dehumidification desalination, and a domestic water heater are joint to the geothermal cycle resulting in a novel trigeneration application. The possibility is measured by thermodynamic, environmental and exergoeconomic tools; a comprehensive sensitivity analysis is applied together with a multi-objective grey wolf optimization in three different optimization scenarios. Considering eight decision variables for the sensitivity analysis and optimization, the optimization scenarios comprise exergetic efficiency/sum unit cost of products, exergetic efficiency/levelized total emission, and exergetic efficiency/hot water production. Here, the last scenario possesses the best optimum exergetic efficiency of 64.49%; the optimum sum unit cost of product, levelized total emission, and heating production are forecasted at 4.94 $/GJ, 0.124 ton/MWh, and 6549.77 kW, respectively.

Exergo-economic and exergo-environmental analysis of a binary geothermal power plant with solar boosting

The exploitation of renewable energies is a solution to the energy, economic and environmental issues related to the massive use of fossil resources. Thus, investing in renewable technologies is essential to achieve the carbon-neutral scenario within 2050. In this framework, geothermal energy may have a key role. In particular, power plants with a closed binary cycle are suitable for harnessing geothermal resources with low and medium enthalpy levels. They are prone to be integrated with other renewable devices to increase the global power output.Geothermal fluid can be drawn constantly from underground throughout the day and seasons. Conversely, the availability and intensity of solar energy depend on weather conditions and the time of year. In Italy, geothermal energy is currently harvested for continuous electricity generation, while solar energy is mainly used for photovoltaic generation. For small-to-medium size plants, rated between 5 and 20 MWe, the geothermal and thermodynamic solar hybridization may lead to relevant benefits for the economic competitiveness regarding separate photovoltaic or thermodynamic solar systems.This article aims to investigate the economic and environmental aspects of geothermal power plants with a closed binary cycle coupled with a topper cycle fed by linear parabolic solar collectors. The system operation in both design and off-design conditions was analysed, and exergo-economic and exergo-environmental simulations were conducted. The application site was selected near Torre Alfina (Italy). It has a water-dominant reservoir with a pressure of 44 bar, a temperature of 140 °C, and content of non-condensable gases (NCGs) approximately equal to 2% by weight. At the design point, the net power is 8.4 MW and the first and second principle efficiencies are 9.31% and 18.45%, respectively. The exergo-economic and exergo-environmental analyses indicate that the components with the highest economic and environmental impact are the condenser, the field of solar collectors, the evaporator, and the low-pressure turbine. The levelized cost of electricity (LCOE) is equal to 14.19 c€/kWh.

Geophysical signature of the transition zone between the sedimentary cover and the basement from an analogue of the Rhine Graben

Exploiting high temperatures geothermal resources in sedimentary and basement rocks, rifts or flexural basins to produce electricity is now possible because of the development of binary geothermal power plant technology. However it remains challenging because the presence of fluid and permeability at 4–5 km depth is necessary. A multi-scale and multi-disciplinary approach to increase our knowledge of the transition zone between the sedimentary cover and the basement have been undertaken to provide fundamental knowledge for the assessment of its geothermal potential. In this paper, we report out the results of a study performed on an exhumed transition zone in the Ringelbach area in the Vosges Mountain, on the flank of the Rhine graben. In this analogue of a deeply buried transition zone of the Rhine Graben, Triassic sandstones are still present on the top of the fractured and altered granitic basement providing the unique opportunity to study in-situ the physical properties of this transition zone. We focused here on electrical and seismic properties of the transition zone as they are the main physical parameters usually assessed with the help of geophysical methods during the exploration phase of a geothermal project.We show that altered porous and potentially permeable granite targeted in deep geothermal exploration has a clear signature on both electrical conductivity and seismic measurements that can be measured at core scale, borehole scale, and are still visible with surface geophysical methods such as refraction and reflection seismic and Controlled Source Electromagnetism at a few hundred meter depth. The results suggest that best discrimination between permeable and non permeable rocks may be provided by the joint interpretation of both resistivity and seismic velocities.

Thermodynamic and mathematical analysis of geothermal power plants operating in different climatic conditions

This study presents the thermodynamic and mathematical analysis of the different cooling systems for geothermal power plants at various climatic conditions. The existing binary geothermal power plant data, located in Turkey, were processed in the commercial software Ebsilon Professional to model the power plant and cooling systems. The dry-bulb temperature and relative humidity values from data obtained from local meteorological stations in the analyzed region are used as variables in the model. The reference air-cooled cooling system, the wet-tower cooling system, the additional dry cooling system and three different hybrid cooling systems are modelled and analyzed separately in the reference geothermal power plant model. Accordingly, mathematical equations are developed to evaluate the power production and water consumption characteristics of cooling systems on the thermodynamic performance of geothermal power plants depending on weather conditions. The power production and water consumption of geothermal power plants can be calculated using hourly ambient temperature and relative humidity data at different climatic conditions with these equations. Considering water reserves in the area, operation periods of the hybrid cooling systems can be determined. Moreover, power plant operators can compare the performance and water consumption characteristics of hybrid cooling systems for different conditions with these equations.

Modeling and design of the new combined double-flash and binary geothermal power plant for multigeneration purposes; thermodynamic analysis

Renewable energy sources have great importance to deal with environmental detriments. To clean and sustainable future, various design renewable energy-assisted plants are of great importance. The current study examines the design and investigation of a double-flash binary geothermal energy-powered integrated system for useful products. For the purpose of producing hydrogen, power, heating, and drying, the proposed work basically consists of two steam turbines, a transcritical carbon dioxide Rankine cycle (tCO2-RC), a PEM electrolyzer, a domestic water heater (DHW), and a dryer. The chief target of this research study is to develop a more efficient plant as well as multigeneration productions. Additionally, detailed parametric modeling is carried out using energetically and exergetically approaches to examine this designed plant in the context of thermodynamic analysis. The variation of some parameters that influence the plant's performance, such as geothermal water temperature, flash pressure, and ambient temperature, are parametrically investigated. Subsequently, the thermodynamic simulation results show that the advised integrated plant produces 4431 kW electrical power. Also, the amount of the hydrogen generation capacity is 0.006809 kgs−1. The tCO2-RC sub-plant's energetic and exergetic performance is determined as 6.18% and 27.14%, respectively. Furthermore, the suggested integrated plant's energetic and exergetic performances are 26.20% and 37.49%. From the results, it can be finalized that the integration of various systems with the geothermal power plant is successfully possible and, in this way, there will be an increase in system performances.

Performance enhancement and multi-objective optimization of a double-flash binary geothermal power plant

Initiating cost-effective and technological frameworks to exploit geothermal energy is a fundamental incentive for scientists and engineers; in this regard, flash-binary geothermal power plants are plausible for high-temperature geothermal resources. Stemming from an in-depth literature review, it is conspicuous that the thermal and exergy losses of the expansion process are significant. To shed light on this matter, an ejector-expander is integrated into the conventional expansion valve of a double-flash binary geothermal power plant to enhance the plant performance. The feasibility of the contrived notion is scrutinized from energy, exergy, thermal, and cost balance standpoints and results converged in the increase in turbine output power, energy efficiency, and exergy efficiency of approximately 7.66%, 7.64%, and 7.69%, respectively. Among all components, the condenser constituted a 45.06% share of the overall exergy destruction, whilst the turbine had an exergy destruction ratio of 22.07%. An intensive parametric study is implemented that outlined that the turbine output power, energy efficiency, and exergy efficiency of the ejector-expander power system have a maximum in a specified pressure value of the first and second separator. Another merit was a marked decrease in the unit cost of power when ejector-expander is employed.

Exergetic and financial parametric analyses and multi-objective optimization of a novel geothermal-driven cogeneration plant; adopting a modified dual binary technique

The use of flash-binary geothermal power plants is recognized as an appropriate concept for preparing a sustainable energy production facility. Hence, the target of the current research is to specify the exergetic and economic aspects of an innovative electricity and cooling cogeneration system comprising a dual-flash binary geothermal power plant and an ejector refrigeration unit. The essential point of this study is the smart use of the total capacity of a medium-temperature geothermal source to produce energy-based products and eliminate the weakness of the conventional setups, increasing the exergy and exergoeconomic performances. A parametric study has been implemented to analyze the effect of several main parameters on the vital variables including efficiencies, exergy destruction rate, sum unit exergy cost, investment cost rate, and exergoeconomic factor. Besides, a multi-objective optimization in different cases has been applied to the calculations through a non-dominated sorting genetic algorithm II (NSGA-II) to achieve an optimal design. The results showed that the performance of the system was more sensitive to changing the separators’ operating pressure of the plant. Likewise, the optimum exergy efficiency and optimum unit exergy cost of the system were found to be 12% and 0.0043 $/kWh through the exergy/cost multi-objective optimization case, correspondingly.

Different design aspects of an Organic Rankine Cycle turbine for electricity production using a geothermal binary power plant

In recent years, pressure has been growing to increase the share of renewable energy sources in electricity generation, which may offer opportunities for the development of geothermal energy in regions that have been so far considered unprofitable in this respect. One such country currently undergoing an energy transition is Poland in which low-temperature geothermal resources are currently used for district heating and recreation purposes. Nevertheless, research on the possibilities of using geothermal energy for electricity production is ongoing. The objective of this paper was to perform a comprehensive analysis of a binary power plant construction in relation to low-temperature petro-geothermal resources. The potential binary power plant is located in the area characterized by temperature of 120 °C at depths of 5000 m. About half of Poland’s area, especially the regions of western and central Poland, has these characteristics. It was assumed that brine at volume flow rate of 400 m3/h is a heat source for the Organic Rankine Cycle with isobutane as a working medium. The thermal efficiency based on the First Law of Thermodynamics and the power output were estimated at 10.5% and 1.79 MWe, respectively. In addition, the thermal efficiency based on the Second Law of Thermodynamics was calculated at 29.0%. For the calculated cycle parameters, a preliminary design of a two-stage axial turbine was constructed. All results were compared to the other binary power plants and they confirm that establishing the binary power plant in Poland would be thermodynamically justified. The main novelty of the present work is the combination of three issues, namely the selection of the low- temperature heat source, the design and analysis of the cycle together with a turbine adapted to these conditions.