Geomechanical modelling of spent fluid reinjection in the Hengill geothermal field

2020 ◽  
Author(s):  
Vanille A. Ritz ◽  
Antonio P. Rinaldi ◽  
Elisa Colas ◽  
Raymi Castilla ◽  
Peter M. Meier ◽  
...  
Keyword(s):  
Power Plants ◽  
Production Capacity ◽  
Geothermal Field ◽  
Maximum Pressure ◽  
Total Production ◽  
Traffic Light ◽  
Induced Earthquakes ◽  
Driving Mechanisms ◽  
Demonstration Site ◽  
Stochastic Simulator

<p align="justify"><span>Monitoring micro-seismicity during operations of a geothermal field is critical to the understanding of seismic hazard and changes in the reservoir. In the context of a geothermal project, induced earthquakes are an important tool to enhance the permeability and thus productivity of reservoirs and to image structure and processes. However, felt and/or damaging earthquakes are a major threat to societal acceptance and regulatory license to operate. With the adaptive data-driven tool ATLS (Adaptive Traffic Light System), we aim at managing and mitigating the risk posed by induced earthquakes during stimulation and operations, while at the same time ensuring and optimising the productivity.</span></p><p align="justify"><span>The demonstration site for the application of ATLS lies in the Hengill volcanic region located in the South-West of Iceland, host to two power plants (Hellisheiði and Nesjavellir) with a total production capacity of 423 MW</span><sub><span>e</span></sub><span> and 433MW</span><sub><span>th</span></sub><span>. The production of energy and heat is accompanied by reinjection of the spent geothermal water in dedicated areas, both to maintain production and to comply with legal requirements. These reinjection areas have been showing different seismic responses to drilling and injection operations. We investigate these different behaviours by performing numerical modelling for two of the reinjection regions. </span></p><p align="justify"><span>Two models are compared: TOUGH2-Seed, a full 3-dimensional stochastic simulator and an analytical model based on a cumulative density function linking maximum pressure in the reservoir and reactivation. Those two models fulfil two different aspects of the development of an ATLS, with the full 3D allowing an in-depth dive in the driving mechanisms of induced seismicity; and the analytical solution providing a robust and fast approximation of the forecast for real-time application. We show that both models can reproduce observed seismicity patterns in the Hengill geothermal field.</span></p>

Effect of Chemical Hythane Composition on Pressure in Combustion Chamber of Engine

2019 ◽  
pp. 36-42
Author(s):  
A. P. Shaikin ◽  
I. R. Galiev
Keyword(s):  
Natural Gas ◽  
Combustion Chamber ◽  
Power Plants ◽  
Engine Speed ◽  
Combustion Engine ◽  
Fuel Mixture ◽  
Maximum Pressure ◽  
Chamber Volume ◽  
Excess Air ◽  
Scientific Papers

The article analyzes the influence of chemical composition of hythane (a mixture of natural gas with hydrogen) on pressure in an engine combustion chamber. A review of the literature has showed the relevance of using hythane in transport energy industry, and also revealed a number of scientific papers devoted to studying the effect of hythane on environmental and traction-dynamic characteristics of the engine. We have studied a single-cylinder spark-ignited internal combustion engine. In the experiments, the varying factors are: engine speed (600 and 900 min-1), excess air ratio and hydrogen concentration in natural gas which are 29, 47 and 58% (volume).The article shows that at idling engine speed maximum pressure in combustion chamber depends on excess air ratio and proportion hydrogen in the air-fuel mixture – the poorer air-fuel mixture and greater addition of hydrogen is, the more intense pressure increases. The positive effect of hydrogen on pressure is explained by the fact that addition of hydrogen contributes to increase in heat of combustion fuel and rate propagation of the flame. As a result, during combustion, more heat is released, and the fuel itself burns in a smaller volume. Thus, the addition of hydrogen can ensure stable combustion of a lean air-fuel mixture without loss of engine power. Moreover, the article shows that, despite the change in engine speed, addition of hydrogen, excess air ratio, type of fuel (natural gas and gasoline), there is a power-law dependence of the maximum pressure in engine cylinder on combustion chamber volume. Processing and analysis of the results of the foreign and domestic researchers have showed that patterns we discovered are applicable to engines of different designs, operating at different speeds and using different hydrocarbon fuels. The results research presented allow us to reduce the time and material costs when creating new power plants using hythane and meeting modern requirements for power, economy and toxicity.

Effects of Steam Injection Flow in Burner and Outside Water Tube to the Increasing of Boiler Temperature

2007 ◽  
Vol 7 (1 & 2) ◽  
pp. 120
Author(s):  
M. Djoni Bustan
Keyword(s):  
Human Life ◽  
Combustion Process ◽  
Production Capacity ◽  
Steam Injection ◽  
Oil Refinery ◽  
Specific Enthalpy ◽  
Maximum Pressure ◽  
Injection Flow ◽  
Electrical Generator ◽  
Generator Unit

Energy is an expensive basic need for human life, especially energy from fossils, such as crude oil, gas, and coal. In an oil refinery factory or electrical generator unit, where heat is most dominantly utilized, the boiler is used to generate steam. The main problem in a boiler is its uncompleted combustion process because of the incomplete ratio of air–fuel. This problem is caused by the addition of deposits or sealing inside and outside of the tube fire heater which will reduce the performance of fired heater. The objective of this research is to study the effect of steam flow variation on burner and tubing for increasing heat and temperature as well as the quality of steam. This research used a package boiler B&W series 1986 model which can be seen at an oil refinery factory or steam power electrical generator unit in Indonesia. This package boiler has 50kg/hours steam production capacity, qualified superheated steam, maximum pressure and temperature at 7kgs/cms2 and 700oC. Quantitatively, the achievable heat efficiency which corresponded to the temperature increase caused by the steam injection is 41.25% and the specific enthalpy is 12.07%.

Influence of Surge Tank and Relief Valve on Transient Flow Behaviour in Hydropower Stations

2011 ◽  
Author(s):  
Alireza Riasi ◽  
Ahmad Nourbakhsh
Keyword(s):  
Power Plants ◽  
Transient Flow ◽  
Flow Analysis ◽  
Internal Boundary ◽  
Transient Condition ◽  
Maximum Pressure ◽  
Surge Tank ◽  
Small Hydropower ◽  
Relief Valve ◽  
Hydropower Stations

Unsteady flow analysis in water power stations is one of the most important issues in order to predict undesirable pressure variations in waterways and also probable changes in rotor speed for the power plants safe operation. Installation of surge tank and relief valve is the two main methods for controlling of hydraulic transient. The relief valve is used in several medium and small hydropower stations instead of the surge tank and mounted on the penstock near the powerhouse. The recent generation of relief valves are reliable and beneficial and consist of fully control system that directly conducted by governor. This paper presents a numerical method for transient flow in hydropower stations using surge tank and relief valve. For this purpose the governing equations of transient flow in closed conduit are solved using the method of characteristics (MOC) using unsteady friction. Hydraulic turbine, surge tank and relief valve are considered as internal boundary conditions. The influence of surge tank and also relief valve on the maximum pressure in spiral case and turbine over speed has been studied for a real case. The results show that the transient condition is considerably improved by using a relief valve and this device can be mounted in lieu of an expensive surge tank.

3D and 4D seismic imaging of the Nesjavellir geothermal field, Iceland

2021 ◽  
Author(s):  
Ortensia Amoroso ◽  
Ferdinando Napolitano ◽  
Vincenzo Convertito ◽  
Raffaella De Matteis ◽  
Thorbjörg Ágústsdóttir ◽  
...  
Keyword(s):  
Power Plants ◽  
Clean Energy ◽  
B Value ◽  
Geothermal Field ◽  
Parameters Estimation ◽  
Central Volcano ◽  
The European Union ◽  
Small Magnitude ◽  
Geothermal Activity ◽  
4D Seismic

<p>The Nesjavellir geothermal field in the Northeastern part of the Hengill central volcano, South West Iceland, has been exploited since 1990. Geothermal energy is currently produced by Reykjavík Energy (OR) at two power plants around Hengill, at Nesjavellir to the northeast and at Hellisheiði to the southwest. Part of the surplus geothermal water from both plants goes into injection wells, and in analogy with the nearby Hellisheiði power plant the re-injection of geothermal gases into basaltic formations is planned in Nesjavellir. Currently, a test of deep fluid injection is conducted in preparation of the experimental re-injection of carbon dioxide and hydrogen sulphide. The seismicity recorded in the study area is due to volcano-tectonic processes, natural geothermal activity as well as induced seismicity due to production and injection.</p><p>The aim of this work is to seismically image the production area of the Nesjavellir geothermal plant. Where the elastic properties of the propagation medium are investigated through the 3D and 4D seismic tomography and the b-value.</p><p>The available dataset in Nesjavellir consists of 6906 seismic events extracted from ÍSOR’s catalogue, with local magnitude -0.8≤M<sub>L</sub>≤3.8 recorded between October 2016 and June 2020. The earthquakes were relocated in a 1D velocity model optimized for the area. We used tomographic method in which the P- and S-arrival times are simultaneously inverted for earthquakes location and velocity parameters estimation. Re-located earthquakes are further analysed to image the b-value in the investigated volume. Time variations of the seismic properties of the medium are observed in terms of V<sub>P</sub>, Vs and V<sub>P</sub>/Vs ratio obtained from the 4D tomography.</p><p>The results indicate that seismicity in Nesjavellir is mainly concentrated in three different clusters: two are located at shallow depths (1-2 km) while the third reaches down to 6 km depth. The three clusters of earthquakes are striking SW-NE and are all dipping to the west. Both the P- and S-velocity obtained models show lateral variation in E-W direction. A high V<sub>P</sub>/Vs ratio value is observed at shallow depths (due to low Vs values) and high V<sub>P</sub>/V<sub>S</sub> ratio is observed between 3.5 and 6 km depth (due to high V<sub>P</sub> and low Vs values). From the b-value mapping we observe low values (less than 1) at shallow depths and high values where the rate of small magnitude events is considerably higher. For each timestep we observe variations in V<sub>P</sub> and V<sub>S</sub> velocities that seem to be correlated with the fluids involved in field operation.</p><p>This work has been supported by the S4CE ("Science for Clean Energy") project, funded by the European Union’s Horizon 2020 - R&I Framework Programme, under grant agreement No 764810 and by PRIN-2017 MATISSE project, No 20177EPPN2, funded by the Italian Ministry of Education and Research.</p>

A New Modeling and Application of Hierarchical Production Planning Approach

2013 ◽  
pp. 113-144
Author(s):  
Reza Tanha Aminlouei
Keyword(s):  
Power Systems ◽  
Production Planning ◽  
Power Plants ◽  
Production Capacity ◽  
Total Load ◽  
Hierarchical Production Planning ◽  
Time Horizons ◽  
Planning Approach ◽  
Utility Cost ◽  
Equal Space

In real power systems, power plants are not in the equal space from the load center, and their fuel cost is different. With common utilization conditions, production capacity is more than total load demand and losses. Therefore, there are different criteria for active and inactive power planning in each power plant. The best selection is to choose a framework in which the utility cost is minimized. On the other hand, planning in power systems has different time horizons; thus, for effective planning in power systems, it is very important to find a suitable mathematical relationship between them. In this chapter, the authors propose a modeling by selecting a Fuzzy Hierarchical Production Planning (FHPP) technique with zone covering in the mid-term and long-term time horizons electricity supply modeling in the Iran global compact network.

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>

CENTESIL: A Pilot Plant for R&D in Polysilicon

2009 ◽  
Vol 1210 ◽  
Author(s):  
Carlos del Cañizo ◽  
Araceli Rodríguez ◽  
Gabriel Ovejero ◽  
Antonio Luque
Keyword(s):  
Pilot Plant ◽  
Semiconductor Industry ◽  
New Ventures ◽  
Production Capacity ◽  
Industry Structure ◽  
Research Centre ◽  
Total Production ◽  
Independent Research ◽  
The Past ◽  
Solar Cell Technology

AbstractThe tremendous expansion and the relative avidity for silicon of the solar cell technology has resulted in a dramatic change of the polysilicon industry structure. While in the past the polysilicon was manufactured almost exclusively for the semiconductor industry, in 2008 around 67% of the total production was consumed by the solar industry. The consequence is that while in 2000 virtually only 7 companies supplied all the polysilicon consumed worldwide, in 2008 there were 11 major suppliers and numerous new ventures entering this market. Based on this in 2006 CENTESIL was founded as a new private-public partnership venture to deal with the polysilicon research. For it, a pilot plant is in advanced state of construction that has been preceded of some laboratory-size implementations. The pilot plant is designed for a production capacity of 60 kmol of trichlorosilane per day and 2 t of purified silicon per batch at the CVD reactor. The purpose is to allow the photovoltaic companies worldwide to count with an independent research centre to help them to establish their own polysilicon plant. The R&D activities already carried out by CENTESIL and the present status of the project are discussed in the paper.

Production Control Strategy and its Parameters Optimization for a Two-Stage Production System

2013 ◽  
Vol 748 ◽  
pp. 1223-1228
Author(s):  
Hai Xia Wang ◽  
Le Cao ◽  
Ping Yan
Keyword(s):  
Control Strategy ◽  
Production System ◽  
Production Control ◽  
Production Capacity ◽  
Parameters Optimization ◽  
Total Production ◽  
Two Stage ◽  
Threshold Control ◽  
System A ◽  
Standby System

On-off of the standby system is an important factor that influences the performance of the production system. A dual threshold control strategy based on the on-off control of the standby system is proposed for the optimal control of the two-stage production system for which the last stage has stochastic production capacity. A control parameters optimization model is built with the objective of minimizing the total production cost, and a genetic algorithm is adopted to resolve the optimization problem. Finally, an example is taken to validate the effectiveness of the proposed dual threshold control strategy and the parameter optimization algorithm.

scholarly journals A STUDY OF FIELD GEOTHERMAL POWER POTENTIAL & THERMODYNAMIC CONCEPTS OF PROSPECTIVE BINARY POWER CYCLE BASED GEOTHERMAL POWER PLANT FOR TATAPANI GEOTHERMAL FIELD.

2020 ◽  
Vol 9 (12) ◽  
pp. 90-104
Keyword(s):  
Power Plant ◽  
Power Plants ◽  
Exergy Analysis ◽  
Geothermal Field ◽  
Flow Diagram ◽  
Exergy Destruction ◽  
Geothermal Power Plant ◽  
Power Cycle ◽  
Geothermal Fields ◽  
Geothermal Power

Tatapani Geothermal field is one of the most promising low-enthalpy geothermal fields in central India, located on Son-Narmada lineament in the state of Chhattisgarh, India. The Tatapani geothermal field geological, geo-chemical & reservoir data has been compiled and analysed for evaluating true power potential & better understanding of the field. The low enthalpy geothermal reservoirs can be utilized for power production using Organic Rankine Cycle (ORC) or binary power cycle. Based on previous research works done, the Tatapani geothermal field has been found to be very prospective and has got huge potential for power generation. The binary power cycle has been studied in detail along with thermodynamic concepts. In addition, similar low enthalpy geothermal power plants (conceptual & existing both) have been thoroughly studied in order to understand the concepts and methodology to perform technical feasibility based on thermodynamic and exergy analysis. The literature review covers the previous works done on Tatapani geothermal field including works on other geothermal fields in India along with previous research works for Thermodynamic & Exergy Analysis carried-out for binary geothermal power plants across the world for similar low enthalpy prospects. The methods of performing thermodynamic and exergy analysis for a potential geothermal power plant has been studied and compared. Exergy analysis highlights the areas of primary exergy destruction at various plant components and can be illustrated in the form of exergy flow diagram. The loss of exergy indicates the potential reasons for the inefficiencies within a process and exergic efficiency as conversion of input heat energy from the brine in to useful work output. The exergic efficiencies can be calculated for each component along with exergy destruction. The detailed study has been conducted in order to gather the knowledge regarding conducting the feasibility of setting up binary geothermal power plant at Tatapani from technical point of view using thermodynamic concepts.

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