Geofluid Temperature Research Articles

Comparative analysis of geothermal binary ORC systems: performance and environmental considerations for CO2 andwater as geofluids

This study considers the process simulation of geothermal binary Organic Rankine Cycle (ORC) systems which utilizes CO2 and water as geofluids for electricity generation. The simulation was performed using Hysys v11 software by using Peng Robinson’s fluid property package. Two dry working fluids including isopentane and n-pentane, were used. The effects of geofluid temperature and working fluid mass flowrate on power generation, as well as the maximum pressure of working fluids were evaluated. The result showed that power generation increases with higher geofluid temperature due to enhanced heat transfer. Isopentane outperformed n-pentane, attributed to its superior thermodynamic properties. CO2 showed better performance as geofluid than water highlighting its superiority, observed in the increased power generation. The unique characteristics of CO2 enable efficient heat transfer at lower temperatures, making it an environmentally friendly and effective choice. Contrarily, the use of water as a geofluid poses some implications for local ecosystems and water resources. From an environmental perspective, CO2 shows greater potential for reduced environmental impact, which aligns with the transition to cleaner energy sources. However, the economic considerations suggest a trade-off, as CO2 projects may entail higher upfront costs compared to water-based systems. Regulatory factors and economic feasibility, therefore, play a crucial role in the choice of geofluid for geothermal power generation.

A study on geothermal electricity systems for Tibet geothermal fields considering thermal performance, economic analysis, and CaCO3 scaling

In this article, thermodynamic performance, economic analysis, and calcite scaling assessment have been completed for each of the investigated geothermal electricity systems for Tibetan geothermal fields. The seven investigated electricity production systems include the organic Rankine cycle (ORC), dual-stage ORC (DSORC), triple-stage ORC (TSORC), single-flash (SF), double-stage flash (DSF), single-flash ORC (SFORC), and double-stage-flash ORC (DSFORC). A selection map for suitable geothermal electricity production systems has been generated. The DSORC and TSORC can generate 20% more net power output than the SF system under low dryness and medium-low temperature conditions. When the geofluid temperature and dryness increase, flash systems (SF, DSF, SFORC, and DSFORC) have better applicability. In the Yambajan geothermal field, the SF system has the highest electricity production cost (EPCSF = 0.056 USD/kWh), while the DSORC system has the lowest cost (EPCDSORC = 0.047 USD/kWh). In the Gulu geothermal field, the DSORC is still the most economical system (EPCDSORC = 0.022 USD/kWh), but the DSFORC becomes the least cost-effective system (EPCDSFORC = 0.027 USD/kWh). The scaling associated with using the ORCs (ORC, DSORC, and TSORC) only occurs at the wellhead with a scaling rate of about 2.30 kg/day. In the case of using the flash systems, CaCO3 also precipitates in the system's components; it is found that the scaling rate associated with using the DSF system has a maximum value, which is around 3.864 kg/day. The results obtained in this study are considered useful for the design and operation of geothermal power industries.

The influence of temperature on geothermal power plant performance based on geology in Huangshadong geothermal field, China

The geological structure is rather complicated in Guangdong province, in China. The 10 deep fault belts are mainly oriented in North-East. The North-East fault belts are good channels for deep thermal energy upwelling, which can form a geothermal water reservoir zone. The heating of atmospheric precipitation and surface water by deep rocks is the primary formation mechanism for the hydrothermal resources in the Huangshadong geothermal field. The results show that the two-stage conversion system of flash-binary is more reasonable when the geofluid temperature is higher than 130?C. With every 10?C increment of geofluid temperature for flash-binary system, the power output and exergy efficiency in-crease by 21.6-38.7% and 6.0-13.1%, respectively. The power output and exergy efficiency will decrease by about 20-40% when cooling temperature arising from 15?C to 25?C. The research will provide the basic data for the demonstration of geothermal resource exploitation.

Deep geothermal energy extraction, a review on environmental hotspots with focus on geo-technical site conditions

Knowledge about the environmental impacts of geothermal energy is important for understanding the role this technology could play in the transition towards sustainable energy production systems. In this study 30 life cycle assessment (LCA) studies on geothermal energy plants were reviewed, focusing on the major environmental hotspots and the cause-effect relationships between the geo-technical parameters and these environmental impacts. The variability in the reported environmental impacts is explained, and a more transparent picture of the geological, design and technical factors causing these impacts is provided by triangularly evaluating the reported results based on the plant's geo-technical characteristics (such as, well depth and geofluid temperature), the life cycle inventory, and the hotspot analysis results. The study focuses on six impact indicators that have been identified as high priority for geothermal energy by the GEOENVI project, as well as the water consumption impact. The results indicate that the impacts vary in magnitude and across different life cycle phases. Apart from the type of energy conversion technology used, differences in the geological and design parameters also introduce large variability in the impact results reported in the literature. Furthermore, all the reviewed LCAs adopt a static approach. Therefore, we present a research agenda that highlights the need to perform dynamic LCAs on geothermal energy exploitation plants to consider the changing context in which these technologies are operating.

Theoretical Study of a Novel Power Cycle for Enhanced Geothermal Systems

As obtained geofluids from enhanced geothermal systems usually have lower temperatures and contain chemicals and impurities, a novel power cycle (NPC) with a unit capacity of several hundred kilowatts has been configured and developed in this study, with particular reference to the geofluid temperature (heat source) ranging from 110 °C to 170 °C. Using a suitable CO2-based mixture working fluid, a transcritical power cycle was developed. The novelty of the developed power cycle lies in the fact that an increasing-pressure endothermic process was realized in a few-hundred-meters-long downhole heat exchanger (DHE) by making use of gravitational potential energy, which increases the working fluid’s pressure and temperature at the turbine inlet and, hence, increases the cycle’s power output. The increasing-pressure endothermic process in the DHE has a better match with the temperature change of the heat source (geofluid), as does the exothermic process in the condenser with the temperature change of the sink (cooling water), which reduces the heat transfer irreversibility and improves the cycle efficiency. Power cycle performance has been analyzed in terms of the effects of mass fraction of the mixture working fluids, the working fluid’s flowrate and its DHE inlet pressure, geofluid flowrate, and the length of the DHE. Results show that, for a given geofluid’s temperature and mass flowrate, the cycle’s net power output is a strong function of the working-fluid’s flowrate, as well as of its DHE inlet pressure. Too high or too low of a DHE inlet pressure results in a lower power output. When geofluid temperature is 130 °C, the optimum DHE inlet pressure is found to be 11 MPa, corresponding to an optimum working-fluid flowrate of 6.5 kg/s. The longer the DHE, the greater the corresponding working-fluid flowrate and the higher the net power output. For geofluid temperature ranging from 110 °C to 170 °C, the developed NPC has a better thermodynamic performance than the conventional ORC. The advantage of using the developed NPC becomes obvious when geofluid temperature is low. The maximum net power output difference between the NPC and the ORC happens when the geofluid temperature is 130 °C and NPC’s working fluid mass fraction (R32/CO2) is 0.5/0.5.

Performance analysis and working fluid selection of an Organic Rankine Cycle Power Plant coupled to an Enhanced Geothermal System

This paper presents a coupled Wellbore-Reservoir-Organic Rankine Cycle (ORC) power plant model for sustainable and efficient use of multiple-fractures Enhanced Geothermal System with simulations conducted over 40 years of operation time. A multi-objective optimization of the ORC under off-design conditions was conducted using constrained NSGA-II technique considering specific investment cost, energy and exergy efficiencies as objective functions. Twenty working fluids were considered to select the best one based on the turbine inlet superheated vapor condition, the lowest specific investment cost, the best energy and exergy efficiencies. Optimal operations conditions were determined for each working fluid considering turbine inlet temperature, turbine inlet pressure, condenser temperature, refrigerant mass flow rate, and length, tubes number, inner diameter and outer diameter of evaporator and condenser, isentropic turbine efficiency, isentropic pump efficiency as decision variables. The results show that the working fluids have a significant effect on the reinjection geofluid temperature and slight effect on the production temperature. The best performing working fluid was R1233zd(E) providing an energy efficiency of 19.2–19.32% and the exergy efficiency found is between 56.4% and 58.44% over the 40 years of production in off-design conditions and optimal operation conditions. The energy efficiency and the exergy efficiency decrease with increasing condenser temperature.

Optimum operation of a novel ejector assisted flash steam cycle for better utilization of geothermal heat

Dual flash steam cycle (DFSC) is a proven technology to produce power from hot geothermal water. However, in a DFSC, substantial exergy destruction occurs during the two flashing processes. A good amount of thermal energy is also lost with the saturated water exiting the low-pressure vapour separator (LPVS). In the present study, saturated water exiting the high-pressure vapour separator (HPVS) of the geothermal flash steam cycle is used as the motive stream of an ejector. The ejector enhances the pressure of the steam exiting the high-pressure turbine. The steam exits the diffuser of the ejector at a two-phase state. The dry saturated vapour separated from this two-phase steam is expanded through a low-pressure turbine to produce some power output. It is observed that the use of the ejector helps to reduce the exergy loss with the mass of geothermal water entering into the injection well. For 210 °C geo-fluid temperature, the maximum achievable power output of the flash steam cycle with ejector (FSCWE) is 6.67% higher compared to that of the baseline DFSC. While delivering the maximum power at said geo-fluid temperature, the use of the ejector also reduces the levelized cost of electricity (LCOE) by 4.5% compared to that of the baseline cycle.

Thermodynamic and Techno‐economic Analysis of a Triple‐pressure Organic Rankine Cycle: Comparison with Dual‐pressure and Single‐pressure ORCs

AbstractInvestigation of a triple‐pressure organic Rankine cycle (TPORC) using geothermal energy for power generation with the net power output of the TPORC analyzed by varying the evaporation pressures, pinch temperature differences (tpp) and degrees of superheat (tsup) aimed to find the optimum operation conditions of the system. The thermodynamic performance of the TPORC was compared with a dual‐pressure organic Rankine cycle (DPORC) and a single‐pressure ORC (SPORC) for geofluid temperatures ranging from 100°C to 200°C, with particular reference to the utilization of a hot dry rock (HDR) geothermal resource. Thermodynamic performances of the TPORC system using eight different organic working fluids have also been investigated in terms of the net power outputs. Results show that a higher geofluid mass flow rate can make a considerable contribution to shortening the payback period (PBP) as well as to decreasing the levelized electricity cost (LEC), especially when the geofluid temperature is low. For the temperature range investigated, the order from high to low based on thermodynamic and techno‐economic performances is found to be TPORC > DPORC > SPORC. In terms of using geothermal resources within the given temperatures range (100°C–200°C), the TPORC system can be a better choice for geothermal power generation so long as the wellhead geofluid temperature is between 140°C and 180°C.

Effects of two-phase expander on the thermoeconomics of organic double-flash cycles for geothermal power generation

The use of a two-phase expander in place of the throttling valve can improve the organic double-flash cycle (ODFC) thermal efficiencies. This work compares the thermoeconomics of a regenerative ODFC (RODFC), an expander-ODFC (EODFC) and a double expander-ODFC (DEODFC). The evaporation and flash temperatures of these cycles are optimized to maximize the net power outputs for geofluid temperatures of 120–180 °C. The results show that the two-phase expander in EODFC leads to the lowest optimal first-stage flash temperature with the highest vapor mass flow rate for the high-pressure turbine. The power generated by the two-phase expanders in DEODFC is less than that generated by the expander in EODFC but the power generated by the turbines is 5.9–8.4% higher. DEODFC produces the maximum net power, followed by EODFC and RODFC for each geofluid temperature. The exergy losses during evaporation are reduced by up to 41% by regeneration in RODFC, EODFC and DEODFC. The two-phase expanders increase the exergy losses during power generation but decrease the losses during throttling and condensation; thus, the exergy efficiency of DEODFC increases to 32.8–46.8%. The levelized cost of electricity for DEODFC is 15–33% lower than for ODFC due to the great increase in the net power output.

Energy conversion of heat from abandoned oil wells to mechanical refrigeration - Transient analysis and optimization

This study investigates the potential of using the geothermal energy from abandoned oils in a novel three-loop system; geothermal, power and cooling loops to produce cooling effect. The geothermal loop drives the power and cooling loops of a thermo-mechanical refrigeration (TMR) system consisting of expander-compressor units (ECUs). The system advantages lie in its simple, flexible, and low-cost design as well as in its ability to be driven by a low-temperature heat source (as low as 60 °C). To evaluate the performance of the system, comprehensive models are developed including transient model for the abandoned oil well (geothermal loop) in spatial and time domains and thermodynamic and optimization models for the entire three-loop system. The effects of the temperature variation of the geofluid over operation time, the working fluids, the high pressure and the temperatures of the heat source and sink are investigated. Results show that at realistic and conservative conditions, the geofluid temperature considerably decreases for the first four months of operation (by an average of 30 °C) and tends to be constant after half a year of operation. However, the geofluid temperature still high enough to drive the proposed geothermal TMR system over the full operation period. Among 43 investigated refrigerants, R1234ze(E) has higher efficiency, lower Pumping Work Ratio (PWR), and requires a smaller size of the heat exchangers. Using the genetic algorithm optimization method with R1234ze(E) as working fluid in both power and cooling loops, a maximum power loop efficiency of 6.3% and COP of 5.3 were obtained at a high pressure of 29 bar (in the power loop) with minimal expander diameter of 64, compressor diameter of 171 mm, and 18 expander-compressor units.

Space cooling using geothermal single‐effect water/lithium bromide absorption chiller

AbstractThis research is proposed to fully investigate the performance of a single‐effect water/lithium bromide absorption chiller driven by geothermal energy. Since absorption cycles are considered as low‐grade energy cycles, this innovative idea of rejecting fluid from a single‐flash geothermal power plant with low‐grade energy would serve as efficient, economical, and promising technology. In order to examine the feasibility of this approach, a residential building which is located in Sharjah, UAE, considered to evaluate its cooling capacity of 39 kW which is calculated using MATLAB software. Based on the obtained cooling load, modeling of the required water/lithium bromide single‐effect absorption chiller machine is implemented and discussed. A detailed performance analysis of the proposed model under different conditions is performed using Engineering Equation Solver software (EES). Based on the obtained results, the major factors in the design of the proposed system are the size of the heat exchangers and the input heat source temperature. The results are presented graphically to find out the geofluid temperature and mass flow and solution heat exchanger effectiveness effects on the chiller thermal performance. Moreover, the effects of the size of all components of the absorption chiller on the cooling load to meet the space heating are presented. The thermal efficiency of the single‐flash geothermal power plant is about 13% when the power plant is at production well temperature 250℃, separator pressure 0.24 MPa, and condenser pressure 7.5 kPa. The results show that the coefficient of performance (COP) reaches about 0.87 at solution heat exchanger effectiveness of 0.9, when the geofluid temperature is 120℃.

Energy and exergy analyses of single flash geothermal power plant at optimum separator temperature

Abstract In this work, a thermodynamic analysis consisting of energy and exergy analyses is carried out to determine the performance of a single flash geothermal power plant. A new derivation for determination of the optimum separator temperature, which results in maximum turbine power output, is achieved. The energy and exergy analyses are carried out at that optimum separator temperature. The thermodynamic derivation showed that the separator would result in maximum performance of the power plant when it operates at the average value of the production well and condenser temperatures. Moreover, the derivation was numerically validated by calculating three different values for the geothermal well temperatures. The results show that the highest exergy destruction rate is in the expansion valve followed by the steam turbine, the mixing process and the pump. The separator has exactly zero exergy destruction rate while the condenser has almost zero exergy destruction rate. The results also show that the exergy destruction rate for all components of the power plant decreases with reduction in the geofluid temperature of the production well except for the condenser. The maximum energy efficiency of the power plant is about 12.5, 11 and 9.5% when the geofluid of the geothermal well temperature is 300, 275 and 250°C, respectively.

Thermodynamic and exergoeconomic analysis of two novel tri-generation cycles for power, hydrogen and freshwater production from geothermal energy

Thermodynamic and exergoeconomic analysis of two novel tri-generation systems based on single and double flash are reported to generate power and produce hydrogen and freshwater from geothermal energy. Both proposed cycles use the organic Rankine cycle to generate power, proton exchange membrane electrolyzer to produce hydrogen and reverse osmosis desalination to produce freshwater. The proposed cycles are assessed based on the thermodynamic and exergoeconomic approaches. Different single-objective optimizations are done to maximize produced power and thermal and exergy efficiencies as well as minimize power production cost. Multi-objective optimization is also performed based on weight coefficients. Moreover, the thermodynamic and exergoeconomic parameters of the proposed systems in different conditions are investigated through a comprehensive parametric study. The results showed that the tri-generation system based on the double flash (system 2) has better performance from the exergy and exergoeconomic viewpoints compared to the single flash-based one (system 1) so that the optimum values of 8613 kW, 2.308 kg/hr, 9.502 kg/s, 12.96%, 53.79%, and 5.845 $/GJ are obtained for net power output, hydrogen production rate, desalinated water rate, energy and exergy efficiencies, and power specific cost of this system at the geofluid temperature of 200 ℃.

Energy, Environmental, and Economic Analyses of Geothermal Polygeneration System Using Dynamic Simulations

This paper presents a thermodynamic, economic, and environmental analysis of a renewable polygeneration system connected to a district heating and cooling network. The system, fed by geothermal energy, provides thermal energy for heating and cooling, and domestic hot water for a residential district located in the metropolitan city of Naples (South of Italy). The produced electricity is partly used for auxiliaries of the thermal district and partly sold to the power grid. A calibration control strategy was implemented by considering manufacturer data matching the appropriate operating temperature levels in each component. The cooling and thermal demands of the connected users were calculated using suitable building dynamic simulation models. An energy network dedicated to heating and cooling loads was designed and simulated by considering the variable ground temperature throughout the year, as well as the accurate heat transfer coefficients and pressure losses of the network pipes. The results were based on a 1-year dynamic simulation and were analyzed on a daily, monthly, and yearly basis. The performance was evaluated by means of the main economic and environmental aspects. Two parametric analyses were performed by varying geothermal well depth, to consider the uncertainty in the geofluid temperature as a function of the depth, and by varying the time of operation of the district heating and cooling network. Additionally, the economic analysis was performed by considering two different scenarios with and without feed-in tariffs. Based on the assumptions made, the system is economically feasible only if feed-in tariffs are considered: the minimum Simple Pay Back period is 7.00 years, corresponding to a Discounted Pay Back period of 8.84 years, and the maximum Net Present Value is 6.11 M€, corresponding to a Profit Index of 77.9% and a maximum Internal Rate of Return of 13.0%. The system allows avoiding exploitation of 27.2 GWh of primary energy yearly, corresponding to 5.49∙103 tons of CO2 avoided emissions. The increase of the time of the operation increases the economic profitability.

Optimization and applicability of compound power cycles for enhanced geothermal systems

Both thermodynamic performance and techno-economic analysis of compound power cycles for enhanced geothermal systems have been investigated in this study. Thermodynamic analysis were carried out for four power generation systems: single-flash (SF) system, double-flash (DF) system, flash-ORC (FORC) system; and double-flash-ORC (DFORC) system. By choosing the maximum net power output as an objective function, optimization is done based on comparisons among the four systems with a goal of increasing the net power output by 20% under the condition that the SF is replaced by one of the compound systems (DF, FORC, and DFORC). As an original contribution, five maps useful for real applications have been generated for selecting optimum geothermal power cycles under different geofluid’s conditions, with consideration of five ORC working fluids (R123, R152a, isobutane, n-pentane and R245fa). The boundaries that determine whether the compound systems have advantages over the SF system are functions of the geofluid temperature, geofluid dryness, and the type of the working fluid used by the ORC. In the techno-economic study, Levelized Electricity Cost (LEC) and Payback Period (PBP) analyses were carried out. The results from the LEC and PBP studies show good agreement. For the three scenarios analyzed, each of the compound power systems has a better engineering economic performance than the SF system. For the “common” heat source condition investigated, comparison among the three compound systems shows that the DF system has a lowest levelized electricity cost and the shortest payback period; the FORC and DFORC show similar techno-economic performance and have advantages over the SF system.

Thermo-economic evaluation of various bottoming ORCs for geothermal power plant, determination of optimum cycle for Sabalan power plant exhaust

Thermo-Economic analysis was applied to four different arrangements of Organic Rankine Cycle, using dry organic fluid as working fluid. These cycles were designed to use the geothermal outlet of the Sabalan flash cycle as a heat source. Evaluations were made for the proposed systems to determine the effects of important operating parameters such as turbine inlet pressure, condenser temperature, pinch point temperature and mass flow rate of geofluid on energy and exergy efficiencies, as well as total production cost. Moreover, objective functions of this parametric study were to maximize energy and exergy efficiency levels and to minimize the total production cost. Optimal values of operating parameters were determined by EES optimization using the “variable metric” searching method and defining bounds for each variable as constraints. Among cycles, the maximum energy and exergy efficiency of 20.57% and 63.72% were calculated in the IHE-ORC. The obtained results from the cost optimization, revealed that the lowest energy production cost and the lowest total energy cost were calculated to be related to the R-ORC (25.1 $/GJ) and B-ORC (2.47 M$/year), respectively.The main aim of this study was to use of Fuzzy TOPSIS as Multi-Criteria Decision Making (MCDM) technique to rank cycles based on problem criteria of thermodynamic and economic performance. These criteria include: energy efficiency (N1), exergy efficiency (N2), net power output (N3), production cost (N4) and total cost rate (N5). The method of Interval Shannon's Entropy was used to determine weight values of the criteria automatically. Thus multi-criteria analysis showed that the IHE-ORC was the best system in Sabalan. Additionally, the Basic, Regenerative and Dual fluid ORC were ranked second, third and fourth respectively.

Design and off-design models of a hybrid geothermal-solar power plant enhanced by a thermal storage

Abstract Geothermal resources are subject to thermal depletion during the lifetime of geothermal power plants. The decline of the geofluid temperature significantly affects both the magnitude and quality of the thermal energy available for electrical conversion and, in turn, plant efficiency and power output. Furthermore, the performance of geothermal power plants based on air-cooled Organic Rankine Cycle systems (ORCs) markedly decreases at warm ambient temperatures because of the higher turbine exhaust pressures. In this study a new hybrid Geothermal - Concentrating Solar Power (GEO-CSP) plant is modelled, which enables a better utilization of geothermal energy and improves the performance of the geothermal ORC system during the whole lifetime of the power plant. Solar energy is used to heat up the geothermal fluid entering the heat exchanger of the ORC. The CSP plant is equipped with a thermal energy storage (TES) unit which accumulates the surplus of solar thermal energy available during daytime, while releasing it during night-time when the efficiency of the power system is higher. The integration of the storage unit in the parabolic trough CSP system enables a 19% gain in the incremental annual energy production from solar, which raises from 5.3% to 6.3% compared to the geothermal-only plant. Thus, the hybrid plant may greatly benefit from the addition of a TES unit.

A study on generating a map for selection of optimum power generation cycles used for Enhanced Geothermal Systems

A useful map is generated for selecting optimum power generation cycles used for Enhanced Geothermal Systems. Detailed analysis on the thermodynamic performance has been carried out for four power generation systems: single-flash (SF), double-flash (DF), flash-organic Rankine cycle (FORC), and double-flash-organic Rankine cycle (DFORC). Only subcritical ORC cycles with R245fa as working fluid are analyzed in the study. The map is generated based on comparisons among the four systems with a goal of increasing the net power output by 20% under the condition that the SF is replaced by one of the upgraded systems (DF, FORC, and DFORC). Geofluid's temperature and dryness have strong influences on the performance of each system. FORC has the best thermodynamic performance when the geofluid's temperature is less than 170 °C. DF should be used if the temperature of the geofluid is greater than 170 °C and the steam dryness is less than 0.2. When the steam dryness is greater than 0.2, either DFORC or DF could be an option, but the DFORC is more attractive under a lower geofluid's temperature condition. In terms of engineering economy, DFORC is the most cost-effective system when the geofluid has a relative high temperature and dryness. FORC has a shorter payback period than DF system under the same geofluid's condition.

Energy efficiency comparison between geothermal power systems

The geothermal water which can be considered for generating electricity with the temperature ranging from 80? to 150? in China because of shortage of electricity and fossil energy. There are four basic types of geothermal power systems: single flash, double flash, binary cycle, and flash-binary system, which can be adapted to geothermal energy utilization in China. The paper discussed the performance indices and applicable conditions of different power system. Based on physical and mathematical models, simulation result shows that, when geofluid temperature ranges from 100? to 130?, the net power output of double flash power is bigger than flash-binary system. When the geothermal resource temperature is between 130? and 150?, the net power output of flash-binary geothermal power system is higher than double flash system by the maximum value 5.5%. However, the sum water steam amount of double flash power system is 2 to 3 times larger than flash-binary power system, which will cause the bigger volume of equipment of power system. Based on the economy and power capacity, it is better to use flash-binary power system when the geofluid temperature is between 100? and 150?.

Problems and outlooks for petrothermal power engineering (review)

A review is given for the state of the art and future development of the geothermal power engineering. Different diagrams of GeoPP are shown for different levels of geofluid temperature. A special focus is made on challenges for petrothermal power production. The huge amount of heat from petrothermal resources can be harnessed through creating geothermal circulation systems within the dry rocks. Estimates for system lifetime and heat production capacity of circulation systems are given for different flow rates of coolant.