Numerical Analysis of Geothermal Heat Exchangers to be Implemented in a Geothermal-Solar Hybrid Power Plant for Electricity Production in Mexico

2016 ◽  
Author(s):  
Jorge A. Rangel Arista ◽  
J. Jesús Pacheco Ibarra ◽  
Carlos Rubio-Maya ◽  
Oskar J. González Pedraza ◽  
Daniel Alcantar Martinez
Keyword(s):  
Heat Exchanger ◽  
Numerical Analysis ◽  
Power Plant ◽  
Geothermal Energy ◽  
Hybrid Plant ◽  
Electricity Production ◽  
Borehole Heat Exchanger ◽  
Geothermal Heat ◽  
Mexican Government ◽  
Hybrid Power Plant

The Mexican government due to the need of developing and creating cutting-edge technology for application of renewable energy has created renewable energy centers to develop research projects related to solar, wind and geothermal energy. In particular, geothermal energy has been of great interest due to high geothermal energy potential reported for the country. Regarding the projects approved by the Mexican government, the Universidad Michoacana de San Nicolás de Hidalgo, has been granted with fundings to carry out the design and implementation of a geothermal-solar hybrid plant for electricity production. This project is being developed in the community of San Nicolás Simirao (Michoacan State) where geothermal energy is available and exploited from an existing geothermal well. Initially, the well ran through induction, but fluid flow was not constant for long periods and was not sufficient to obtain a full operation of the geothermal-solar hybrid power plant. Therefore, it was necessary to explore new techniques to extract geothermal energy effectively, meeting design conditions of power plant. One solution might be a geothermal heat exchanger to extract heat from the rock and carry it to the surface. Literature reports two basic configurations of geothermal heat exchangers: one of them is the Downhole Coaxial Heat Exchanger and the other one is Borehole Heat Exchanger. Before making a decision to implement one type or another, several studies were carried out by the authors of this work to determine what type of configuration was most suitable, considering in such studies technical and economic aspects that provided information to continue or not the project. Therefore, in this paper the numerical analysis of both configurations (Downhole Coaxial Heat Exchanger and Borehole Heat Exchanger) is presented. The study was conducted to determine what type of geothermal exchanger presents the best trade-off between maximum heat extraction rate and minimum length to minimize costs. A minimum temperature of 125°C was proposed to reach at the hot fluid heat exchanger outlet, allowing a normal operation of the geothermal-solar hybrid plant. Through numerical analysis was determined that the Borehole Heat Exchanger configuration did not present good heat extractions rates, obtaining that for 100 m length the outlet temperature of the hot fluid was even lower to that of entering into the well. This behavior was attributed to heat loss in the return pipe. For the same configuration, but using a length of 500 m, a temperature of 117.21°C was reached at the heat exchanger outlet. On the other hand, the Downhole Coaxial Heat Exchanger configuration reached a temperature of 118.35°C for a length of 100 m. For a length of 200 m a temperature of 131.25°C was obtained, whereby the facility can operate with the minimum necessary conditions. Finally, for a length of 500 m, a temperature of 134.67°C was reached, showing that this type of configuration is the most suitable to be installed in the geothermal well. Thus the Downhole Coaxial Heat Exchanger configuration has more advantages than the Borehole Heat Exchanger configuration from a technical and economic (by pipe cost) point of view.

Reliability Index of Wind-Solar Hybrid Power Plants using the Expected Energy Not Supplied Method

2019 ◽  
Vol 8 (4) ◽  
pp. 9449-9456
Keyword(s):  
Power Plant ◽  
Power Systems ◽  
Electricity Market ◽  
Reliability Index ◽  
Power Plants ◽  
Initial Conditions ◽  
Hybrid Plant ◽  
Total Power ◽  
Hybrid Power ◽  
Hybrid Power Plant

This paper proposes the reliability index of wind-solar hybrid power plants using the expected energy not supplied method. The location of this research is wind-solar hybrid power plants Pantai Baru, Bantul, Special Region of Yogyakarta, Indonesia. The method to determine the reliability of the power plant is the expected energy not supplied (EENS) method. This analysis used hybrid plant operational data in 2018. The results of the analysis have been done on the Pantai Baru hybrid power plant about reliability for electric power systems with EENS. The results of this study can be concluded that based on the load duration curve, loads have a load more than the operating kW of the system that is 99 kW. In contrast, the total power contained in the Pantai Baru hybrid power plant is 90 kW. This fact makes the system forced to release the load. The reliability index of the power system in the initial conditions, it produces an EENS value in 2018, resulting in a total value of 2,512% or 449 kW. The EENS value still does not meet the standards set by the National Electricity Market (NEM), which is <0.002% per year. Based on this data, it can be said that the reliability of the New Coast hybrid power generation system in 2018 is in the unreliable category.

scholarly journals Scaling in a Geothermal Heat Exchanger at Soultz-Sous-Forêts (Upper Rhine Graben, France): A XRD and SEM-EDS Characterization of Sulfide Precipitates

Geosciences ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 271
Author(s):  
Béatrice A. Ledésert ◽  
Ronan L. Hébert ◽  
Justine Mouchot ◽  
Clio Bosia ◽  
Guillaume Ravier ◽  
...  
Keyword(s):  
Heat Exchanger ◽  
Energy Production ◽  
Electricity Production ◽  
Normal Operation ◽  
Upper Rhine Graben ◽  
Geothermal Heat ◽  
Deep Wells ◽  
Upper Rhine ◽  
Management Issues

The Soultz-Sous-Forêts geothermal site (France) operates three deep wells for electricity production. During operation, scales precipitate within the surface installation as (Ba, Sr) sulfate and (Pb, As, Sb) sulfide types. Scales have an impact on lowering energy production and inducing specific waste management issues. Thus scaling needs to be reduced for which a thorough characterization of the scales has to be performed. The geothermal brine is produced at 160 °C and reinjected at 70 °C during normal operation. In the frame of the H2020 MEET project, a small heat exchanger was tested in order to allow higher energy production, by reinjecting the geothermal fluid at 40 °C. Samples of scales were analyzed by XRD and SEM-EDS, highlighting that mostly galena precipitates and shows various crystal shapes. These shapes can be related to the turbulence of the flow and the speed of crystal growth. Where the flow is turbulent (entrance, water box, exit), crystals grow quickly and mainly show dendritic shape. In the tubes, where the flow is laminar, crystals grow more slowly and some of them are characterized by well-developed faces leading to cubes and derived shapes. The major consequence of the temperature decrease is the increased scaling phenomenon.

Independent Hybrid Power Plant “PEMFC+MEMS” With Use of Molecular Ceramic Membranes to Separate CO and H2

2005 ◽  
Author(s):  
A. V. Soudarev ◽  
A. A. Souryaninov ◽  
V. G. Konakov ◽  
A. S. Molchanov
Keyword(s):  
Power Plant ◽  
Numerical Study ◽  
Ceramic Membranes ◽  
Characteristic Size ◽  
Hybrid Plant ◽  
Normal Operation ◽  
Mean Power ◽  
Hybrid Power ◽  
Target Values ◽  
Hybrid Power Plant

As analysis of thermal-technical parameters of the existing polymer exchange membrane fuel cells (PEMFC) indicated, their electrical efficiency is not above 32–37% which is due to relatively high (10–15%) electric power consumption to cover own needs. Its major percentage falls on pump and compressor drive (air, fuel, water supply) using the AC electric engines connected via converter to FC. A real alternative allowing the efficiency increase up to 45% and higher is to apply hybrid plants when an AC turboelectric generator (TEG) is built into the thermodynamic cycle, the latter operating at the expense of utilization of the FC reagent stream power. TEG is a micro turbocompressor with incorporated turbo generator manufactured on the basis of the micro electric-mechanical system (MEMS) technology. The numerical study over the hybrid cycle effectiveness revealed that the optimum efficiency is ensured provided the TEG power does not exceed 12–15% of the total hybrid power plant power. Considering a value of the PEMFC mean power of around 8, a need arises in TEG of 500 to 1500W power to operate as a part of hybrid engine. Among various auxiliaries involved into the PEMFC, there should be devices that ensure getting target values in terms of hydrogen purity, a dominant synthetic gas fraction, at the FC inlet. A need to get and maintain hydrogen purity on the level of 99.99% is related with that if CO content in mixture is higher 0.01%, then a normal operation of FC fails due to “poisoning” effect of the platinum-containing catalysts of the FC electrodes. To forestall this, the palladium molecular membranes are now typically applied which causes the filtered flow temperature limitations within values not exceeding 500–550°C. At the same time, PEMFC in most cases must operate on air and syngas produced by reforming, with their temperature amounting to 800–900°C. To provide this, we need to have ceramic molecular membranes (CMM) made of a ceramic support in which macropores nano pores are formed (characteristic size of less 0.3nm), the latter achieved through application of a complex of various chemical and physical processes. In the paper presented, findings of numerical studies over a hybrid engine plant are provided, this hybrid plant (PEMFC + MEMS) as compared with alternatives to existing and offered schemes, and, also, test data on the zeolite-based support CMM are demonstrated.

scholarly journals Selecting the Optimal Use of the Geothermal Energy Produced with a Deep Borehole Heat Exchanger: Exergy Performance

Proceedings ◽  
2020 ◽  
Vol 58 (1) ◽  
pp. 20
Author(s):  
Claudio Alimonti ◽  
Paolo Conti ◽  
Elena Soldo
Keyword(s):  
Heat Exchanger ◽  
Geothermal Energy ◽  
District Heating ◽  
High Energy ◽  
Exergy Efficiency ◽  
Deep Borehole ◽  
Borehole Heat Exchanger ◽  
Cascade System ◽  
Wide Range ◽  
Well Depth

The geothermal sector has a strength point with respect to other renewable energy sources: the availability of a wide range of both thermal and power applications depending on the source temperature. Several researches have been focused on the possibility to produce geothermal energy without brine extraction, by means of a deep borehole heat exchanger. This solution may be the key to increase the social acceptance, to reduce the environmental impact of geothermal projects, and to exploit unconventional geothermal systems, where the extraction of brine is technically complex. In this work, exergy efficiency has been used to investigate the best utilization strategy downstream of the deep borehole heat exchanger. Five configurations have been analyzed: a district heating plant, an absorption cooling plant, an organic Rankine cycle, a cascade system composed of district heat and absorption chiller, and a cascade system composed of the organic Rankine plant. District heating results in a promising and robust solution: it ensures high energy capacities per well depth and high exergy efficiency. Power production shows performances in line with typical geothermal binary plants, but the system capacity per well depth is low and the complexity increases both irreversibilities and sensibility to operative and source conditions.

Effect of Load Growth on PLTH Baron Techno Park Performance

2018 ◽  
Vol 1 (4) ◽  
Author(s):  
Mychael Gatriser Pae ◽  
Tegar Prasetyo ◽  
Suharyanto Suharyanto ◽  
T. Haryono ◽  
Ridwan Budi Prasetyo
Keyword(s):  
Power Plant ◽  
Renewable Energy Sources ◽  
Electricity Consumption ◽  
Electrical Energy ◽  
Electricity Production ◽  
Electrical Load ◽  
Plant System ◽  
Hybrid Power ◽  
Load Growth ◽  
Hybrid Power Plant

The reliability of stand-alone and hybrid power plant systems was dependent on electrical loads that the system must supply. For example, on renewable energy sources (RES), Reviews of those systems needs to be calculated well before the development process. One of the most important processes in the initial calculation is the electrical load that must be supplied by the system. The electrical load has a major influence on the amount of power generating capacity. A power plant that has higher electricity production than the load to be fulfilled was considered capable of meeting the system electrical load requirements. However, in terms of the reliability, it is considered as a loss because it will affect the life of the components and the high cost of operating from the system. Therefore, this research discusses the effect of load growth on hybrid power plant system performance of Baron Techno Park. The result of the research shows that the total electricity production of Baron Techno Park hybrid power plant system is 319.695 kWh/year with Net Present Cost (NPC) is $560.077 and the cost of energy (COE) is $0.64/kWh. Total electricity consumption of the PLTH Baron Techno Park is 67.413 kWh/year with total excess electrical energy is 245,547 kWh/year. Load growth of 5%, 10%, 15%, and 20% of the total current load affect the consumption of electric energy, excess electrical energy, and COE. The higher the load growth will affect the total electricity consumption that is increasingly higher so that the total excess electrical energy is lower. This research found that the performance of the system is not influenced by load growth. The highest performance of the system is resulted by the wind turbine of 72.62%, followed by solar panels of 18.82%, and biodiesel of 8.56%.

Field-scale experimental and numerical analysis of a downhole coaxial heat exchanger for geothermal energy production

2021 ◽  
Author(s):  
Sajjan Pokhrel ◽  
Agus P. Sasmito ◽  
Atsushi Sainoki ◽  
Toshiyuki Tosha ◽  
Tatsuya Tanaka ◽  
...  
Keyword(s):  
Heat Exchanger ◽  
Numerical Analysis ◽  
Geothermal Energy ◽  
Energy Production ◽  
Field Scale

Modeling of a SOFC-GT Hybrid Power Plant With Anode Recycling

2010 ◽  
Author(s):  
Denver Cheddie ◽  
Renique Murray
Keyword(s):  
Power Plant ◽  
Gas Turbine ◽  
Power Plants ◽  
Hybrid Plant ◽  
Second Law ◽  
Steam Generation ◽  
Hybrid Power Plant ◽  
External Water ◽  
Gas Turbine Power Plant ◽  
Generation Unit

Power generation using gas turbine power plants operating on the Brayton cycle suffers from low efficiencies and high irreversibilities. In this work, a solid oxide fuel cell (SOFC) is proposed for integration into a 10 MW gas turbine power plant, operating at 30% electrical efficiency (13.7% second law efficiency). The SOFC system entails anode recycling to enable self sustaining reformation reactions, thus alleviating the need for an external water supply and steam generation unit. It also utilizes turbine outlet heat recovery to ensure a sufficiently high SOFC operating temperature. The power output of the hybrid plant is 26.2 MW at 63.4% efficiency (35.3% second law efficiency). The hybrid plant performs best when 70–80% anode recycling is used. A thermo-economic model predicts a payback period of 4.6 years, based on future projected SOFC cost estimates.

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