Retrofitting a Geothermal Power Plant to Optimize Performance: A Case Study

1999 ◽  
Vol 121 (4) ◽  
pp. 295-301 ◽  
Author(s):  
M. Kanog˘lu ◽  
Y. A. C¸engel
Keyword(s):  
Power Plant ◽  
Power Output ◽  
Operating Conditions ◽  
Optimum Operating ◽  
Geothermal Power Plant ◽  
Northern Nevada ◽  
Single Flash ◽  
Geothermal Power ◽  
Net Power Output ◽  
Double Flash

Performance evaluation of a 12.8-MW single-flash design geothermal power plant in Northern Nevada is conducted using actual plant operating data, and potential improvement sites are identified. The unused geothermal brine reinjected back to the ground is determined to represent about 50 percent of the energy and 40 percent of the exergy available in the reservoir. The first and second-law efficiencies of the plant are determined to be 6 percent and 22 percent, respectively. Optimizing the existing single-flash system is shown to increase the net power output by up to 4 percent. Some well-known geothermal power generation technologies including double-flash, binary, and combined flash/binary designs as alternative to the existing system are evaluated and their optimum operating conditions are determined. It is found that a double-flash design, a binary design, and a combined flash/binary design can increase the net power output by up to 31 percent, 35 percent, and 54 percent, respectively, at optimum operating conditions. An economic comparison of these designs appears to favor the combined flash/binary design, followed by the double-flash design.

Performance Enhancement of Single Flash Geothermal Power Plants

2005 ◽  
Author(s):  
S. Barsin ◽  
K. Aung
Keyword(s):  
Power Plant ◽  
Power Output ◽  
Capital Investment ◽  
Power Plants ◽  
Performance Enhancement ◽  
Operating Pressure ◽  
Geothermal Power Plant ◽  
Single Flash ◽  
Geothermal Power ◽  
Temperature Liquid

The present work investigates thermodynamic optimum conditions with respect to resource utilization by varying the operating pressure of flash drum for an existing geothermal power plant. The main focus of the study is to maximize the power output by minimizing the waste of liquid geothermal fluid re-injected to the well. For this purpose a double-flash system has been incorporated and the effect of operating at optimum flash pressures for both primary and secondary flash units is studied. An economic model is developed that calculates the total capital investment based on the cost of major equipments including pumps, flash drums, turbine generators, and condensers. From the results obtained it can be concluded that the plant at Svartsengi currently is working close to the optimum flashing pressure for the single-flash geothermal power plant. Providing an additional flash unit to convert the high temperature liquid coming from primary flash for Svartsengi and Nevada power plants increases the net power output by 12.7% and 28.9% respectively.

Improving the Performance of an Existing Air-Cooled Binary Geothermal Power Plant: A Case Study

1999 ◽  
Vol 121 (3) ◽  
pp. 196-202 ◽  
Author(s):  
M. Kanog˘lu ◽  
Y. A. C¸engel
Keyword(s):  
Power Plant ◽  
Power Output ◽  
Plant Performance ◽  
Working Fluid ◽  
Maximum Pressure ◽  
Geothermal Power Plant ◽  
Northern Nevada ◽  
Binary Geothermal Power Plant ◽  
Geothermal Power ◽  
Cooling Air

An existing air-cooled binary geothermal power plant in northern Nevada is studied. The current performance of the plant is analyzed with an emphasis on the effects of seasonal climate changes. Two potential sites have been identified to improve the performance of the plant. Northern Nevada has a dry climate, particularly in hot summer months, and the temperature of cooling air can be decreased considerably by evaporative cooling. When the air temperature is decreased to the wet-bulb temperature, the decrease in the condenser temperature is determined to increase the power output by up to 29 percent. The required amount of water for this case is calculated to be about 200,000 tons per yr. Several parametric studies are performed by simulating the operation of the plant with an equation solver with built-in thermophysical property functions. It is determined that the net power output of the plant can be increased by 2.8 percent by optimizing the maximum pressure in the cycle. Also, replacing the existing working fluid isobutane by other commonly used binary fluids such as butane, R-114, isopentane, and pentane do not produce as much of an improvement in the plant performance as operating with isobutane at the optimum maximum pressure. Therefore, isobutane appears to be the best choice for this power plant.

scholarly journals Exergy Analysis Using a Theoretical Formulation of a Geothermal Power Plant in Cerro Prieto, México

Entropy ◽  
2021 ◽  
Vol 23 (9) ◽  
pp. 1137
Author(s):  
Dario Colorado-Garrido ◽  
Gerardo Alcalá-Perea ◽  
Francisco Alejandro Alaffita-Hernández ◽  
Beatris Adriana Escobedo-Trujillo
Keyword(s):  
Power Plant ◽  
Second Law Of Thermodynamics ◽  
Second Law ◽  
Exergy Destruction ◽  
Theoretical Formulation ◽  
Geothermal Power Plant ◽  
Single Flash ◽  
Geothermal Power ◽  
Cerro Prieto ◽  
Double Flash

The purpose of this research is the calculation of the exergy destruction of the single-flash and double-flash cycles of a geothermal power plant located on the ladder of the 233 m Cerro Prieto volcano, on the alluvial plain of the Mexicali Valley, Mexico. The methodology developed in this research presents thermodynamic models for energy and exergy flows, which allows determining the contribution of each component to the total exergy destruction of the system. For the case-base, the results indicate that for the single-flash configuration the efficiency of the first and second law of thermodynamics are 0.1888 and 0.3072, as well as the highest contribution to the total exergy destruction is provided by the condenser. For the double-flash configuration, the efficiency of the first and second law of thermodynamics are 0.3643 and 0.4983. The highest contribution to the total exergy destruction is provided by the condenser and followed by the low-pressure turbine.

scholarly journals LCA and Exergo-Environmental Evaluation of a Combined Heat and Power Double-Flash Geothermal Power Plant

2021 ◽  
Vol 13 (4) ◽  
pp. 1935
Author(s):  
Vitantonio Colucci ◽  
Giampaolo Manfrida ◽  
Barbara Mendecka ◽  
Lorenzo Talluri ◽  
Claudio Zuffi
Keyword(s):  
Life Cycle ◽  
Power Plant ◽  
Environmental Analysis ◽  
Combined Heat And Power ◽  
Hot Water ◽  
Environmental Cost ◽  
Published Data ◽  
Geothermal Power Plant ◽  
Geothermal Power ◽  
Double Flash

This study deals with the life cycle assessment (LCA) and an exergo-environmental analysis (EEvA) of the geothermal Power Plant of Hellisheiði (Iceland), a combined heat and power double flash plant, with an installed power of 303.3 MW for electricity and 133 MW for hot water. LCA approach is used to evaluate and analyse the environmental performance at the power plant global level. A more in-depth study is developed, at the power plant components level, through EEvA. The analysis employs existing published data with a realignment of the inventory to the latest data resource and compares the life cycle impacts of three methods (ILCD 2011 Midpoint, ReCiPe 2016 Midpoint-Endpoint, and CML-IA Baseline) for two different scenarios. In scenario 1, any emission abatement system is considered. In scenario 2, re-injection of CO2 and H2S is accounted for. The analysis identifies some major hot spots for the environmental power plant impacts, like acidification, particulate matter formation, ecosystem, and human toxicity, mainly caused by some specific sources. Finally, an exergo-environmental analysis allows indicating the wells as significant contributors of the environmental impact rate associated with the construction, Operation & Maintenance, and end of life stages and the HP condenser as the component with the highest environmental cost rate.

Performance Analysis and Optimization of Double-Flash Geothermal Power Plants

2006 ◽  
Vol 129 (2) ◽  
pp. 125-133 ◽  
Author(s):  
Ahmet Dagdas
Keyword(s):  
Power Plant ◽  
Performance Analysis ◽  
Electricity Generation ◽  
Power Plants ◽  
Second Law ◽  
Western Turkey ◽  
Geothermal Power Plant ◽  
Base Points ◽  
Geothermal Power ◽  
Double Flash

One of the most important cycles for electricity generation from geothermal energy is the double-flash cycle. Approximately 25% of the total geothermal based electricity generation all over the world comes from double-flash geothermal power plants. In this paper, performance analysis of a hypothetical double-flash geothermal power plant is performed and variations of fundamental characteristics of the plant are examined. In the performance analysis, initially, optimum flashing pressures are determined, and energy and exergy values of the base points of the plant are calculated. In addition, first and second law efficiencies of the power plant are calculated. Main exergy destruction locations are determined and these losses are illustrated in an exergy flow diagram. For these purposes, it is assumed that a hypothetical double-flash geothermal power plant is constructed in the conditions of western Turkey. The geothermal field where the power plant will be built produces geofluid at a temperature of 210°C and a mass flow rate of 200kg∕s. According to simulation results, it is possible to produce 11,488kWe electrical power output in this field. Optimum first and second flashing pressures are determined to be 530kPa and 95kPa, respectively. Based on the exergy of the geothermal fluid at reservoir, overall first and second law efficiencies of the power plant are also calculated to be 6.88% and 28.55%, respectively.

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