scholarly journals A Project To Estimate The Power Capacity Of Geothermal Power Plants Based On The Enthalpy Of Geothermal Fluid And Plant Design

2021 ◽  
Author(s):  
Obumneme Oken
Keyword(s):  
Power Plant ◽  
Power Output ◽  
Geothermal Energy ◽  
Power Plants ◽  
Hot Water ◽  
Geothermal Resource ◽  
Power Capacity ◽  
Geothermal Fluid ◽  
Single Flash ◽  
Geothermal Power

Surface phenomena that signal the presence of viable geothermal energy can be found in various locations in Nigeria. None of these locations have been explored extensively to determine the feasibility of sustainable geothermal energy development for electricity generation or direct heating purposes. In this context, the present study aims to provide insight into the energy potential of such development based on the enthalpy estimation of geothermal reservoirs. This particular project was conducted to determine the power output from a geothermal resource given an estimated enthalpy of the geothermal fluid. The process route chosen for this project is the single-flash geothermal power plant because of the temperature (180℃) and unique property of the geothermal fluid (a mixture of hot water and steam that exists as a liquid under high pressure). The Ikogosi warm spring in Ekiti State, Nigeria was chosen as the site location for this power plant. To support food security efforts in Africa, this project proposes the cascading of a hot water stream from the flash tank to serve direct heat purposes in agriculture for food preservation, before re-injection to the reservoir. The flowrate of the geothermal fluid to the flash separator was chosen as 3125 tonnes/hr. The power output from a single well using a single flash geothermal plant was evaluated to be 11.3 MW*. This result was obtained by applying basic thermodynamic principles, including material balance, energy balance, and enthalpy calculations. This particular project is a prelude to a robust model that will accurately determine the power capacity of geothermal power plants based on the enthalpy of geothermal fluid, size of the geothermal resource, and different plant designs. I hope that the knowledge gained from the study will promote best practices in geothermal engineering and emphasize appropriate planning for, and implementation of, geothermal plants.

scholarly journals A Project To Estimate The Power Capacity Of Geothermal Power Plants Based On The Enthalpy Of Geothermal Fluid And Plant Design

2021 ◽  
Author(s):  
Obumneme Oken
Keyword(s):  
Power Plant ◽  
Geothermal Energy ◽  
Electricity Generation ◽  
Power Plants ◽  
Hot Water ◽  
Power Capacity ◽  
Geothermal Fluid ◽  
Direct Heating ◽  
Single Flash ◽  
Geothermal Power

Nigeria has some surface phenomena that indicate the presence of viable geothermal energy. None of these locations have been explored extensively to determine the feasibility of sustainable geothermal energy development for electricity generation or direct heating. In this context, the present study aims to provide insight into the energy potential of such development based on the enthalpy estimation of geothermal reservoirs. This particular project was conducted to determine the amount of energy that can be gotten from a geothermal reservoir for electricity generation and direct heating based on the estimated enthalpy of the geothermal fluid. The process route chosen for this project is the single-flash geothermal power plant because of the temperature (180℃) and unique property of the geothermal fluid (a mixture of hot water and steam that exists as a liquid under high pressure). The Ikogosi warm spring in Ekiti State, Nigeria was chosen as the site location for this power plant. To support food security efforts in Africa, this project proposes the cascading of a hot water stream from the flash tank to serve direct heat purposes in agriculture for food preservation, before re-injection to the reservoir. The flowrate of the geothermal fluid to the flash separator was chosen as 3125 tonnes/hr. The power output from a single well using a single flash geothermal plant was evaluated to be 11.3 MW*. This result was obtained by applying basic thermodynamic principles, including material balance, energy balance, and enthalpy calculations. This particular project is a prelude to a robust model that will accurately determine the power capacity of geothermal power plants based on the enthalpy of fluid and different plant designs.

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.

scholarly journals Wellhead Power Plants Improvement by Introduction of Double Flashing Cycle

2019 ◽  
pp. 24-32
Author(s):  
Thomas Mutero ◽  
Peter Muchiri ◽  
Nicholas Mariita
Keyword(s):  
Power Plant ◽  
Geothermal Energy ◽  
Power Plants ◽  
Low Pressure ◽  
Geothermal Field ◽  
Power Cycle ◽  
Single Flash ◽  
Geothermal Power ◽  
Installed Capacity

Kenya Electricity Generating Company Ltd (KenGen) has harnessed geothermal energy for over thirty seven years at the Olkaria geothermal field. The total installed capacity of geothermal energy in Kenya currently stands at 703.5 MW generated mostly by single flash and binary geothermal power plants. In the 1990s KenGen considered the Wellheads concept in which modular containerized single flash power plants were to be designed, customized and built on a wellpad for optimized well potential; this approach has largely been successful currently having an installed capacity of 83.5 MW and accounting for 15.7% of KenGen's total geothermal installed capacity. This was done to address an inherent deficiency in the construction of conventional geothermal power plants which was identified as the long period taken to put up the power plants. The wells that have been drilled by KenGen and GDC, tested and shut in awaiting the installation of power plants are rated at about 600 MW. The Wellhead power plant cycle is a single flash geothermal power plant; this research intended to improve the current Wellheads power cycle by introducing a second low pressure separator to harness more energy from the wellheads, design a turbine to be driven by the low pressure steam and evaluate an economic justification for introducing the double flashing cycle. A case study was carried out at Wellhead 914 and Wellhead 915. Data collected indicated that the combined mass flow rate of brine from wells in the two wellpads was 240.4 tonne per hour. This brine was saturated at 13.5 bar-a and at a temperature of 193.40C as it exits the high pressure separator for disposal. The optimal pressure of the low pressure separation was designed at 2.5 bar-a, 127.40C and had an ability to generate 3871 kW of electric power. A turbine operating at a steam inlet pressure of 2.5 bar-a, a speed of 6804 rpm and having an exhaust pressure of 0.075 bar-a was designed. The designed turbine had 4 stages of both stationary and moving blades with a maximum rotor disc diameter of 0.62 meters and an output of 4195 kW. The simple payback period for this project was estimated to be 1.9 years with a rate of return on investment of 42.24%. This would also minimize energy wastage by improving efficiency and footprints on the environment arising from the Wellhead power plants.

Go With the Flow: The Evolvement of Geothermal Wellhead Maintenance at the Hellisheidi Power Plant

2014 ◽  
Author(s):  
Reynir S. Atlason ◽  
Oli P. Geirsson ◽  
Ari Elisson ◽  
Runar Unnthorsson
Keyword(s):  
Power Plant ◽  
Geothermal Energy ◽  
Power Plants ◽  
Waiting Times ◽  
District Heating ◽  
Real Data ◽  
Energy Company ◽  
Power Company ◽  
Geothermal Power ◽  
Maintenance Model

Iceland relies greatly on geothermal energy, for electricity, district heating and industrial activities. It is therefore of great importance that the maintenance on site is carried out quite successfully to minimize down time. Reykjavik Energy is the largest energy company in Iceland utilizing geothermal energy. The company operates two cogenerating geothermal power plants, Hellisheidi (303 MWe and 133 MWt) and Nesjavellir (120 MWe and 300 MWt). In this study we investigate the development of the wellhead maintenance at the Hellisheidi geothermal power plant. We look at the maintenance recommendations provided to on-site employees and how maintenance procedures have developed since the power plant began its operations. We investigate real data retrospectively and use it to calculate expected waiting times between repairs. The result is a maintenance model based on the observed and statistically analyzed data provided by the power company on the maintenance procedures. Such model should prove of great significance to other geothermal power plants in the early stages of planning the wellhead maintenance.

Feasibility, Design and authorization of a zero-emission Geothermal Power Plant in Italy; Case Study: “Montenero” Project

2020 ◽  
Author(s):  
Paolo Basile ◽  
Roberto Brogi ◽  
Favaro Lorenzo ◽  
Tiziana Mazzoni
Keyword(s):  
Power Plant ◽  
Power Plants ◽  
Geothermal Field ◽  
Geothermal Reservoir ◽  
Gas Content ◽  
Geothermal Resources ◽  
Geothermal Fluid ◽  
Geothermal Power Plant ◽  
Green Power ◽  
Geothermal Power

<p><span><span>Social consensus is a </span><span>condition precedent for any intervention having an impact on the territory, such as geothermal power plants. Therefore, private investors studied and proposed innovative solution for the exploitation of the medium enthalpy geothermal resource, with “zero emissions” in atmosphere, with the target of minimizing its environmental impact. “Montenero” project, developed by GESTO Italia, complies with this precondition.</span></span></p><p><span><span>The area covered b</span><span>y the exploration and exploitation permit is located on the northern edge of the great geothermal anomaly of Mt. Amiata (Tuscany), about 10 km north of the geothermal field of Bagnore, included in the homonymous Concession of Enel Green Power.</span></span></p><p><span><span>The geological - structural setting of the area around the inactive volc</span><span>ano of Mt. Amiata has been characterized by researches for the geothermal field of Bagnore, carried out by Enel Green Power over the years. The geothermal reservoir is present in the limestone and evaporitic rocks of the “Falda Toscana”, below which stands the Metamorphic Basement, as testified by the wells of geothermal field of Bagnore. The foreseen reservoir temperature at the target depth of 1.800 m is 140 °C, with an incondensable gas content of 1,8% by weight.</span></span></p><p><span><span>The project was presented to the authorities in 2013 and it is </span><span>now undergoing exploitation authorization and features the construction of a 5 MW ORC (Organic Ranking Circle) binary power plant. The plant is fed by three production wells for a total mass flow rate of 700 t/h. The geothermal fluid is pumped by three ESPs (Electrical Submersible Pump) keeping the geothermal fluid in liquid state from the extraction through the heat exchangers to its final reinjection three wells.</span></span></p><p><span><span>The reinjection temperature is 70 °C and the circuit pressure is maintained above the </span><span>incondensable gas bubble pressure, i.e. 40 bar, condition which prevents also the formation of calcium carbonate scaling. The confinement of the geothermal fluid in a “closed loop system” is an important advantage from the environmental point of view: possible pollutants presented inside the geothermal fluid are not released into the environment and are directly reinjected in geothermal reservoir.</span></span></p><p><span><span>The </span><span>environmental authorization procedure (obtained) has taken into account all the environmental aspects concerning the natural matrices (air, water, ground, ...) potentially affected by the activities needed for the development, construction and operation of “Montenero” ORC geothermal power plant. A numerical modeling was designed and applied in order to estimate the effect of the cultivation activity and to assess the reinjection overpressure (seismic effect evaluation). The project also follows the “best practices” implemented in Italy by the “Guidelines for the usage of medium and high enthalpy geothermal resources” prepared in cooperation between the Ministry of Economic Development and the Ministry of the Environment.</span></span></p>

scholarly journals Regeneration of Electrical Energy from Waste Geothermal Fluid in Geothermal Power Plants

2019 ◽  
Vol 2 (3) ◽  
pp. 525-531
Author(s):  
Mahmut Hekim ◽  
Engin Cetin
Keyword(s):  
Power Plants ◽  
Thermoelectric Generator ◽  
Waste Heat ◽  
Electrical Energy ◽  
Heat Energy ◽  
Hot Water ◽  
Geothermal Resources ◽  
Geothermal Fluid ◽  
Geothermal Power ◽  
Electrical Energy Production

Geothermal power plants are the plants that provide the conversion of thermal energy in geothermal fluid to electrical energy as a result of the extraction of underground hot water resources to the earth by drilling. The total installed power of geothermal power plants in the field of geothermal resources in Turkey has reached 1,336 MW. The geothermal fluid, which is used for electric power generation in geothermal power plants, is re-injected into the underground wells after electrical energy production. For efficient generation of electrical energy in geothermal power plants, it is aimed to reuse the waste heat energy within the geothermal fluid before it is sent to the re-injection well. To achieve this aim, thermoelectric generator modules which convert waste heat energy to electrical energy can be used. In this study, a thermoelectric generator-based geothermal power plant simulator that converts geothermal fluid waste heat into electrical energy is installed and commissioned in the laboratory conditions.

Optimum Flashing Pressure in Single and Double Flash Geothermal Power Plants

2008 ◽  
Author(s):  
Shahin Amiri ◽  
Hossein Shokouhmand ◽  
Ahmad Kahrobaian ◽  
Shayan Amiri
Keyword(s):  
Power Plant ◽  
Thermal Efficiency ◽  
Power Plants ◽  
Analytical Investigation ◽  
Exergy Efficiency ◽  
Maximum Efficiency ◽  
Single Flash ◽  
Geothermal Power ◽  
Double Flash

In this paper an analytical investigation has been reported on determination of the optimum flashing pressures to get maximum efficiency in flash geothermal power plants. Also, two different views on efficiency have been considered; thermal efficiency and exergy efficiency. Both views anticipate very close optimum flashing pressure and in this pressure, exergy efficiency is between 3 to 5.5 times more than thermal efficiency. It is observed that the optimum flashing pressure in a single flash power plant is between the optimum flashing pressures of two separators in a double flash power plant. Also both views predict an increase of 20–29 percent for the efficiency of double flash power plants than the efficiency of single flash power plants.

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.

scholarly journals Utilizing renewable resources – converting geothermal energy to electricity

2020 ◽  
Author(s):  
Miljan Vlahović ◽  
◽  
Milica Vlahović ◽  
Zoran Stević ◽  
◽  
...  
Keyword(s):  
Renewable Resources ◽  
Geothermal Energy ◽  
Power Plants ◽  
Hot Water ◽  
Geothermal Heat ◽  
Geothermal Resources ◽  
Binary Cycle ◽  
Flash Tank ◽  
Solid Soil ◽  
Geothermal Power

According to the official definition, approved by the European Geothermal Energy Council (EGEC), geothermal energy is energy accumulated as heat below the surface of solid soil. Geothermal energy is thermal energy generated and stored in the Earth. It is generally defined as the part of geothermal heat that can be directly utilized as heat or converted into other types of energy. Geothermal resources vary by location and depth towards the Earth's core. Their use is possible for different purposes depending on their temperature. This paper presents the harnessing geothermal resources for electricity generation. There are three main types of geothermal power plants: dry steam plants, flash steam plants, and binary cycle plants. Dry steam plants pipe hot steam from underground into turbines, which powers the generator to provide electricity. Flash steam plants pump hot water from underground into a cooler flash tank. The formed steam powers the electricity generator. Binary cycle plants pump hot water from underground through a heat exchanger that heats a second liquid to transform it into steam, which powers the generator. In all mentioned systems the used fluids are recycled. It can be concluded that geothermal power plants work similarly to other power plants, but providing the steam for starting the turbine from the earth's interior. The fact that used fluids return to the ground makes geothermal energy resources renewable.

scholarly journals Analisa Efisiensi Termal Turbin, Kondensor dan Menara Pendingin pada Pembangkit Listrik Tenaga Panas Bumi

2020 ◽  
Vol 10 (1) ◽  
pp. 05-12
Author(s):  
Clinton Sihombing ◽  
Keyword(s):  
Power Plant ◽  
Thermal Efficiency ◽  
Nuclear Power ◽  
Power Plants ◽  
Cooling Tower ◽  
Geothermal Fluid ◽  
Turbine Condenser ◽  
Calculation Results ◽  
Geothermal Power ◽  
Pass Through

Geothermal power plants have similarities with other generated power plants such as coal, gas or nuclear power that is converting heat energy into electricity. When the geothermal fluid is extracted from the production well, it will pass through many different processes or equipment on the way to the power plant. During this process the geothermal fluid loses unused energy to generate power. The overall efficiency of the power plant can be affected by several parameters, one of them is design of power plant. This study attempts to analysis the thermal efficiency of the generating components: turbine, condenser and cooling tower at one of geothermal power plant in Indonesia. So, we can know how the performance of the component, whether the component is running well or not. From the calculation results obtained that the turbine, condenser and cooling tower currently still operate well with the value of thermal efficiency of 80%-100%.

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