A Simulation Code for Single Phase Geothermal Fields

1999 ◽  
Author(s):  
Francesco Di Maria ◽  
Umberto Desideri
Keyword(s):  
Power Plant ◽  
Flow Rate ◽  
Characteristic Curve ◽  
Geothermal Field ◽  
Cooling Towers ◽  
Ambient Conditions ◽  
Simulation Code ◽  
Geothermal Fluid ◽  
Fluid Network ◽  
Steam Turbine Condenser

Abstract This paper presents a design and off-design study of a geothermal field consisting of a number of wells, a steam network which collects the geothermal fluid, and a power plant to generate electricity. The geothermal field considered is located in Italy and the fluid is a mixture of steam and non-condensable gases. The power plant is a conventional type for vapor dominated fields and has a compressor-extractor to remove non-condensable gases from the condenser. The condenser has wet cooling towers to remove heat. In this study, computer codes developed at the University of Perugia were used to simulate the behavior of geothermal field as a whole. The wells are modeled with second order functions in order to describe pressure-flow rate and temperature-flow rate correlations. The geothermal fluid network is calculated by setting pressures and thermal losses in all the branches. The power plant is simulated with all its components: steam turbine, condenser, gas extractor, cooling towers and auxiliaries. All the components of the geothermal field are simulated at both design and off-design conditions. The fluid network is solved with an algorithm developed by the authors, which allows the definition of boundary conditions by means of curves based on experimental data. The advantage in comparison with conventional techniques, requiring a fixed pressure or flow rate as boundary condition, is that the solution of the network and the power plant is always a real solution. The results show how changes in ambient conditions or in the characteristic curve of one or more plant components may influence power production and the exploitation of the geothermal source.

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>

Estimating Cooling Towers for Power Plant Applications

2006 ◽  
Author(s):  
Hector L. Cruz
Keyword(s):  
Water Flow ◽  
Flow Rate ◽  
Cooling Tower ◽  
Arithmetic Function ◽  
Water Flow Rate ◽  
Mechanical Equipment ◽  
Cooling Towers ◽  
Ambient Conditions ◽  
The Cost ◽  
Basin Area

It has always been difficult to estimate size and cost of well designed counterflow induced-draught cooling towers due to the interrelationship of approach temperature and cooling range associated with each design. Attempts to estimate the cost of a tower by assessing currency per cell, per square foot, per gallon, or currency per other single metric, have never been sufficiently accurate due to the asymptotic nature of the approach temperature versus the tower size arithmetic function. To determine accurate qualitative metrics for cooling tower estimating purposes requires assessing two-variable second-order equations in water-flow-rate/approach-temperature, temperature-range/approach-temperature, wet-bulb-temperature/approach-temperature, and approach-temperature/cost. The design and therefore cost responds to the following variables; 1) Recirculating Water Flow Rate, 2) Inlet Wet Bulb Temperature (WBT), 3) Approach Temperature, and 4) Cooling Tower Range or Heat Duty. With the proper evaluation of these parameters they can be utilized to determine metrics to estimate the following parameters: 1) Number of Cells, 2) Basin Area, 3) Pump Power, 4) Fan Power, and 5) Costs (at today’s prices only). In addition, a percentage breakdown can be calculated for; 1) Structure, 2) Hardware, 3) Mechanical Equipment, 4) Labor, and 5) Miscellaneous items. Although developed for the power industry, the operative model, design, and qualified costing techniques are also valid for large petroleum and chemical process projects, provided the heat duty dissipated, ambient conditions, water quality and flow rate can be accurately predicted. A set of equations are developed which can be used to estimate the significant costs of a proposed cooling tower. Example calculations and data are presented in Annex A.

scholarly journals Thermodynamic Optimization of a Geothermal Power Plant with a Genetic Algorithm in Two Stages

Processes ◽  
2020 ◽  
Vol 8 (10) ◽  
pp. 1277 ◽  
Author(s):  
Mehdi A. Ehyaei ◽  
Abolfazl Ahmadi ◽  
Marc A. Rosen ◽  
Afshin Davarpanah
Keyword(s):  
Genetic Algorithm ◽  
Renewable Energy ◽  
Power Plant ◽  
Output Power ◽  
Flow Rate ◽  
Energy Resources ◽  
Fluid Temperature ◽  
Renewable Energy Resources ◽  
Geothermal Fluid ◽  
Two Stages

Due to the harmful effects and depletion of non-renewable energy resources, the major concerns are focused on using renewable energy resources. Among them, the geothermal energy has a high potential in volcano regions such as the Middle East. The optimization of an organic Rankine cycle with a geothermal heat source is investigated based on a genetic algorithm having two stages. In the first stage, the optimal variables are the depth of the well and the extraction flow rate of the geothermal fluid mass. The optimal value of the depth of the well, extraction mass flow rate, and the geothermal fluid temperature is found to be 2100 m, 15 kg/s, and 150 °C. In the second stage, the efficiency and output power of the power plant are optimized. To achieve maximum output power as well as cycle efficiency, the optimization variable is the maximum organic fluid pressure in the high-temperature heat exchanger. The optimum values of energy efficiency and cycle power production are equal to 0.433 MW and 14.1%, respectively.

scholarly journals Off-Design Dynamic Performance Analysis of a Solar Aided Coal-Fired Power Plant

Energies ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2950
Author(s):  
Vinod Kumar ◽  
Liqiang Duan
Keyword(s):  
Power Plant ◽  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Thermal Efficiency ◽  
Dynamic Performance ◽  
Feed Water ◽  
Saving Rate ◽  
Coal Consumption ◽  
Dynamic Performance Analysis

Coal consumption and CO2 emissions are the major concerns of the 21st century. Solar aided (coal-fired) power generation (SAPG) is paid more and more attention globally, due to the lesser coal rate and initial cost than the original coal-fired power plant and CSP technology respectively. In this paper, the off-design dynamic performance simulation model of a solar aided coal-fired power plant is established. A 330 MW subcritical coal-fired power plant is taken as a case study. On a typical day, three various collector area solar fields are integrated into the coal-fired power plant. By introducing the solar heat, the variations of system performances are analyzed at design load, 75% load, and 50% load. Analyzed parameters with the change of DNI include the thermal oil mass flow rate, the mass flow rate of feed water heated by the solar energy, steam extraction mass flow rate, coal consumption, and the plant thermal efficiency. The research results show that, as DNI increases over a day, the coal saving rate will also increase, the maximum coal saving rate reaches up to 5%, and plant thermal efficiency reaches 40%. It is analyzed that the SAPG system gives the best performance at a lower load and a large aperture area.

Designing Controller System for Integrated Solar Power Plant Using Fuzzy Method

2008 ◽  
Author(s):  
Pourya Shahmaleki ◽  
Mojtaba Mahzoon ◽  
Parmis Shahmaleki
Keyword(s):  
Power Plant ◽  
Control Systems ◽  
Flow Rate ◽  
Solar Power ◽  
Solar Power Plant ◽  
Steam Temperature ◽  
Control Optimization ◽  
Control Requirement ◽  
Enhance Efficiency ◽  
Precise Simulation

A parallel combination of oil cycle and fossil fuel boiler is utilized in the integrated solar power plant (ISPP) to achieve better efficiency and reduce cost of electricity generation. There are two cycles, oil and steam, in an ISPP. To enhance performance and achieve control optimization more precise simulation for power plant dynamics are needed. In this paper, a dynamic simulation of an ISPP was developed using the HYSYS software. To enhance efficiency and reduce damage to turbine due to flow rate variations of produced steam by oil cycle, the prime control requirement is to maintain the inlet steam temperature and flow rate of the turbine at a constant value. In this paper, to control the complete oil cycle, two fuzzy controllers are proposed: continuous controller and a switching controller. In steam cycle three controllers are proposed for boiler and reboiler heat exchanger. These controllers are used to maintain constant the inlet steam temperature and flow rate to turbine. Simulation results of the integrated solar power plant and the control systems show that the applied control systems can manage the oil and steam cycles in different situations.

Hybrid Solar-Geothermal Power Generation to Increase the Energy Production From a Binary Geothermal Plant

2011 ◽  
Author(s):  
Giovanni Manente ◽  
Randall Field ◽  
Ronald DiPippo ◽  
Jefferson W. Tester ◽  
Marco Paci ◽  
...  
Keyword(s):  
Power Plant ◽  
Power Output ◽  
Energy Production ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Working Fluid ◽  
Solar Thermal Energy ◽  
Geothermal Fluid ◽  
Industrial Grade ◽  
Design Values

This article examines how hybridization using solar thermal energy can increase the power output of a geothermal binary power plant that is operating on geothermal fluid conditions that fall short of design values in temperature and flow rate. The power cycle consists of a subcritical organic Rankine cycle using industrial grade isobutane as the working fluid. Each of the power plant units includes two expanders, a vaporizer, a preheater and air-cooled condensers. Aspen Plus was used to model the plant; the model was validated and adjusted by comparing its predictions to data collected during the first year of operation. The model was then run to determine the best strategy for distributing the available geothermal fluid between the two units to optimize the plant for the existing degraded geofluid conditions. Two solar-geothermal hybrid designs were evaluated to assess their ability to increase the power output and the annual energy production relative to the geothermal-only case.

High Flue Gas Flow Rate Tests for Removal and Recovery of Carbon Dioxide under Power Plant Effluent Gas Conditions

2004 ◽  
Vol 30 (6) ◽  
pp. 758-761
Author(s):  
Tomio MIMURA ◽  
Yasuyuki YAGI ◽  
Masaki IIJIMA ◽  
Ryuji YOSIYAMA ◽  
Takahito YONEKAWA
Keyword(s):  
Carbon Dioxide ◽  
Power Plant ◽  
Flow Rate ◽  
Flue Gas ◽  
Gas Flow ◽  
Gas Flow Rate ◽  
Power Plant Effluent ◽  
Removal And Recovery

A NOx Reduction Project for a GT11 Type Gas Turbine

2005 ◽  
Author(s):  
Lars O. Nord ◽  
David R. Schoemaker ◽  
Helmer G. Andersen
Keyword(s):  
Power Plant ◽  
Distribution System ◽  
Gas Turbines ◽  
Nox Reduction ◽  
Measurement Data ◽  
Combustion Stability ◽  
Study Phase ◽  
Nox Emissions ◽  
Ambient Conditions ◽  
Exhaust Temperature

A study was initiated to investigate the possibility of significantly reducing the NOx emissions at a power plant utilizing, among other manufacturers, ALSTOM GT11 type gas turbines. This study is limited to one of the GT11 type gas turbines on the site. After the initial study phase, the project moved on to a mechanical implementation stage, followed by thorough testing and tuning. The NOx emissions were to be reduced at all ambient conditions, but particularly at cold conditions (below 0°C) where a NOx reduction of more than 70% was the goal. The geographical location of the power plant means cold ambient conditions for a large part of the year. The mechanical modifications included the addition of Helmholtz damper capacity with an approximately 30% increase in volume for passive thermo-acoustic instability control, significant piping changes to the fuel distribution system in order to change the burner configuration, and installation of manual valves for throttling of the fuel gas to individual burners. Subsequent to the mechanical modifications, significant time was spent on testing and tuning of the unit to achieve the wanted NOx emissions throughout a major part of the load range. The tuning was, in addition to the main focus of the NOx reduction, also focused on exhaust temperature spread, combustion stability, CO emissions, as well as other parameters. The measurement data was acquired through a combination of existing unit instrumentation and specific instrumentation added to aid in the tuning effort. The existing instrumentation readings were polled from the control system. The majority of the added instrumentation was acquired via the FieldPoint system from National Instruments. The ALSTOM AMODIS plant-monitoring system was used for acquisition and analysis of all the data from the various sources. The project was, in the end, a success with low NOx emissions at part load and full load. As a final stage of the project, the CO emissions were also optimized resulting in a nice compromise between the important parameters monitored, namely NOx emissions, CO emissions, combustion stability, and exhaust temperature distribution.

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