scholarly journals Research on a Coupled Total-Flow and Single-Flash (TF-SF) System for Power and Freshwater Generation from Geothermal Source

2020 ◽  
Vol 10 (8) ◽  
pp. 2689 ◽  
Author(s):  
Guopeng Yu ◽  
Zhibin Yu
Keyword(s):  
Power Generation ◽  
Geothermal Energy ◽  
Energy Utilization ◽  
Condensation Process ◽  
Total Flow ◽  
Combined System ◽  
Geothermal Resources ◽  
Single Flash ◽  
System Output ◽  
Efficiency Effects

In response to the twin development challenges of energy shortage and water-scarcity in worldwide arid to semi-arid regions with geothermal resources, a new combined power and freshwater generation system is proposed for geothermal energy utilization. In this system, a total-flow turbine (TF) is employed to be coupled with the traditional single-flash (SF) system and thereafter the coupled TF-SF system is investigated in this work. In addition to power generation, the exhaust steam from turbines are recovered to produce freshwater through condensation. Based on the novel designed system, the production of both power and water are studied under variable wellhead conditions, including variable wellhead pressures, temperatures, mass flowrates, and vapor qualities. The temperature of the separating point at which the total-flow expansion ends and the steam expansion starts is studied for optimal system output. In addition, the efficiency effects of the total-flow turbine on performance of the combined system is also investigated. The power generation comparison shows good power potential of the proposed TF-SF combined system. An effective total-flow turbine with an average efficiency of 65% can lead to an optimal power capacity, exceeding the traditional single-flash (SF) system by 23.7%. Moreover, more than 1/3 of total wellhead discharge can be recovered as desalinated freshwater by the naturally equipped condensation process of the power plant, showing extra benefit from geothermal energy utilization.

scholarly journals Geothermal potential, chemical characteristic and utilization of groundwater in Serbia

2021 ◽  
Author(s):  
Tanja Petrović Pantić ◽  
Katarina Atanasković Samolov ◽  
Jana Štrbački ◽  
Milan Tomić
Keyword(s):  
Geothermal Energy ◽  
Thermal Water ◽  
Pannonian Basin ◽  
Local Population ◽  
Hydrochemical Facies ◽  
Energy Utilization ◽  
Thermal Waters ◽  
Groundwater Temperature ◽  
Geothermal Resources ◽  
Geothermal Potential

Abstract In order to collect and unify data about all geothermal resources in Serbia, a database is formed. The database allows us to perceive the geothermal resources of Serbia and their potential for utilization. Based on the data available in the geothermal database, the estimated temperatures of reservoirs, heat power, and geothermal energy utilization were calculated. The database contains 293 objects (springs, boreholes) registered at 160 locations with groundwater temperature in the range between 20°C and 111°C. The maximum expected temperature of the reservoir is 146°C (according to the SiO2 geothermometer). Some thermal water is cooled while mixed with cold, shallow water. Geothermal resources are mostly used for balneology and recreation, and less for heating, water supply, bottling, fish and animal farms, agriculture, and technical water. 26% of all geothermal resources is used by the local population or has not been used at all. The annual utilization of geothermal energy for direct heat is 1507 TJ/yr, and the estimated capacity of geothermal energy in Serbia is 111 MWt. The results of analytical work were presented in the form of maps with a geological and hydrogeological background. Thermal waters are mostly registrated in the area of Tertiary magmatism. The three geothermal potential areas are identified: Pannonian basin-Vojvodina Province, Mačva-Srem and area from Jošanička Banja to Vranjska Banja (southern Serbia). Based on chemical analyses, four hydrochemical facies are distinguished. Thermal water mainly belongs to NaHCO3 or CaMgHCO3 hydrochemical facies, usually depending on the primary aquifer: karst, karst-fissured, intergranular or fissured.

scholarly journals Utilization of geothermal springs as a renewable energy source: Vranjska Banja case study

2019 ◽  
Vol 23 (6 Part B) ◽  
pp. 4083-4093
Author(s):  
Stefan Denda ◽  
Jasna Micic ◽  
Ana Milanovic-Pesic ◽  
Jovana Brankov ◽  
Zeljko Bjeljac
Keyword(s):  
Geothermal Energy ◽  
District Heating ◽  
Field Research ◽  
Economic Assessment ◽  
Heating System ◽  
Energy Utilization ◽  
Geothermal Resources ◽  
Geothermal Heating ◽  
Public Facilities ◽  
Total Energy Balance

Despite the significant natural potential, geothermal energy in Serbia has traditionally been used in balneology and recreation, while its share in the country?s total energy balance is almost negligible (0.05%). The present paper deals with the City Municipality of Vranjska Banja as a pioneer in the territory of Serbia in using geothermal energy for heating. The concept and methodology of the present research are directly related to the utilization of geothermal resources for district heating in the Vranjska Banja area. The presented analysis includes: determining the available amount of energy, identifying the energy needs of selected public facilities, and the estimation of investment necessary for energy utilization. A survey, combined with field research, is focused on four public facilities connected to the heating system relying on geothermal sources, as well as on two facilities that should be connected to the system in the next phases. The results show economic, ecological, and technological advantages of using geothermal heating systems, as well as the acceptable price of equipment maintenance. An economic assessment of the transition of one facility from the existing heating system to a system relying on geothermal energy has also been made. The analysis confirms the cost-effectiveness of using geothermal energy and reveals numerous ecological advantages (safe heating, absence of CO2 emission) over other energy sources.

scholarly journals Combined Power and Freshwater Generation Driven by Liquid-Dominated Geothermal Sources

Energies ◽  
2019 ◽  
Vol 12 (8) ◽  
pp. 1562 ◽  
Author(s):  
Guopeng Yu ◽  
Zhibin Yu
Keyword(s):  
Power Generation ◽  
Water Source ◽  
Geothermal Field ◽  
Eastern Africa ◽  
Distinct Advantage ◽  
Condensation Process ◽  
Two Phase ◽  
Turbine Efficiency ◽  
Single Flash ◽  
Steam System

In order to meet the twin challenges of energy shortage and water scarcity in eastern Africa, this paper looks at the feasibilities of using a geothermal water source to produce both fresh water and electricity. In this research, three geothermally sourced combined power and freshwater generation systems are investigated and compared. Two of them are based on traditional power generation systems, including a steam system (SS) and a single-flash system (SFS). The third one is a trilateral flash system (TFS) with a two-phase turbine, which processes the total geofluid flow from the wellhead directly. The power generation potential as well as the condensation process, which produces desalinized freshwater, are investigated for three systems under two typical liquid-dominated well conditions in the Aluto Langano geothermal field in Ethiopia. Results indicate that, suitable total flow turbine efficiency enables the trilateral flash system to be comparable with the steam system and the single-flash system regarding the power generation, especially when the well flow is more liquid dominated. Moreover, freshwater generation is a distinct advantage of the trilateral flash system, and its freshwater output can reach up to be 2.7 times higher than those of traditional systems, making it a promising solution for combined power and freshwater generation.

scholarly journals Selected technical aspects of well construction for geothermal energy utilization in Poland

2018 ◽  
Vol 7 (2) ◽  
pp. 188-199 ◽  
Author(s):  
Barbara Tomaszewska ◽  
Anna Sowiżdżał ◽  
Anna Chmielowska
Keyword(s):  
Geothermal Energy ◽  
Energy Utilization ◽  
Injection Wells ◽  
Geothermal Resources ◽  
Geothermal Heating ◽  
Current State ◽  
Exploratory Wells ◽  
Deep Boreholes ◽  
Deep Geothermal Energy ◽  
Domestic Law

Abstract Geothermal resources have been used in Poland since the 90s of the last century. Since then, several geothermal heating plants, recreation and balneological centers have been operated. Accessing geothermal resources is possible due to deep boreholes that are either brand-new wells or old but revitalized petroleum and/or exploratory wells. In this case, the construction of production and injection wells is of significant importance. The utilization of deep geothermal energy resources is strongly dependent on the binding domestic law regulations – primarily in case of acquiring the concession enabling an execution of geological and drilling works, and subsequently a proper exploitation. The paper presents the current state of development of the geothermal energy sector in Poland, indicating examples of exploitation systems based on deep boreholes. Furthermore, the constructions of existing wells are discussed extensively. The existing examples of old but reconstructed wells in Poland, are characterized. The importance of national law and its influence on the development of a geothermal investment is highlighted, as well.

A Modified Thermodynamic Model to Estimate the Performance of Geothermal Aided Power Generation Plant

2011 ◽  
Vol 347-353 ◽  
pp. 2875-2878
Author(s):  
Ji Yun Qin ◽  
Eric J. Hu ◽  
Graham Nathan
Keyword(s):  
Power Generation ◽  
Thermodynamic Model ◽  
Geothermal Energy ◽  
Large Scale ◽  
Simulation Models ◽  
Rankine Cycle ◽  
Feed Water ◽  
Geothermal Heat ◽  
Geothermal Resources ◽  
Lower Stage

Using geothermal resources to instead of steam bled form the turbine steam to preheat feed water in a conventional Rankine cycle power station is also termed as geothermal aided power generation (GAPG), this offers a significant potential for the large-scale utilization of geothermal energy for power generation. GAPG enables the conversion of low temperature geothermal energy in the case of 90-260°C into power at a higher efficiency. In GAPG system, geothermal heat is used to preheat the feed water of power generation, instead of the extraction steam, thus the steam flows through the lower stages turbine have changed. In other words, the lower stage turbine works under off-design conditions. However, previous simulation models for the GAPG and solar aided power generation (SAPG), have not considered this turbine off-design operation. Under the off-design conditions, the isentropic efficiency of the turbine and pressure, temperature of each stage of turbines change which lead to the change of the output of turbine. In this paper, a modified thermodynamic model has been developed, considering these changes, which then can estimate the performance of a GAPG plant more accurately than the previous models. The results from various models are compared in this paper.

scholarly journals Sustainable Modularity Approach to Facilities Development Based on Geothermal Energy Potential

2021 ◽  
Vol 11 (6) ◽  
pp. 2691
Author(s):  
Nataša Ćuković Ignjatović ◽  
Ana Vranješ ◽  
Dušan Ignjatović ◽  
Dejan Milenić ◽  
Olivera Krunić
Keyword(s):  
Geothermal Energy ◽  
Architectural Design ◽  
Pannonian Basin ◽  
Thermal Power ◽  
Chemical Compositions ◽  
Energy Potential ◽  
Southeastern Part ◽  
Geothermal Resources ◽  
Heating And Cooling ◽  
Different Temperatures

The study presented in this paper assessed the multidisciplinary approach of geothermal potential in the area of the most southeastern part of the Pannonian basin, focused on resources utilization. This study aims to present a method for the cascade use of geothermal energy as a source of thermal energy for space heating and cooling and as a resource for balneological purposes. Two particular sites were selected—one in a natural environment; the other within a small settlement. Geothermal resources come from different types of reservoirs having different temperatures and chemical compositions. At the first site, a geothermal spring with a temperature of 20.5 °C is considered for heat pump utilization, while at the second site, a geothermal well with a temperature of 54 °C is suitable for direct use. The calculated thermal power, which can be obtained from geothermal energy is in the range of 300 to 950 kW. The development concept was proposed with an architectural design to enable sustainable energy efficient development of wellness and spa/medical facilities that can be supported by local authorities. The resulting energy heating needs for different scenarios were 16–105 kW, which can be met in full by the use of geothermal energy.

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