The thermodynamic cycle models for geothermal power plants by considering the working fluid characteristic

2016 ◽  
Author(s):  
Cukup Mulyana ◽  
Reza Adiprana ◽  
Aswad H. Saad ◽  
M. Ridwan H. ◽  
Fajar Muhammad
Keyword(s):  
Power Plants ◽  
Thermodynamic Cycle ◽  
Working Fluid ◽  
Geothermal Power ◽  
Fluid Characteristic

Effects of Various Types of Binary Cycles on Thermal and Exergy Efficiency of Combined Flash-Binary Power Plants

2012 ◽  
Author(s):  
Mahshid Vatani ◽  
Masoud Ziabasharhagh ◽  
Shayan Amiri
Keyword(s):  
Power Plants ◽  
Organic Rankine Cycle ◽  
Internal Heat ◽  
Rankine Cycle ◽  
Exergy Efficiency ◽  
Maximum Efficiency ◽  
Working Fluid ◽  
Internal Heat Exchanger ◽  
Different Types ◽  
Geothermal Power

With the progress of technologies, engineers try to evaluate new and applicable ways to get high possible amount of energy from renewable resources, especially in geothermal power plants. One of the newest techniques is combining different types of geothermal cycles to decrease wastage of the energy. In the present article, thermodynamic optimization of different flash-binary geothermal power plants is studied to get maximum efficiency. The cycles studied in this paper are single and double flash-binary geothermal power plants of basic Organic Rankine Cycle (ORC), regenerative ORC and ORC with an Internal Heat Exchanger (IHE). The main gain due to using various types of ORC cycles is to determine the best and efficient type of the Rankine cycle for combined flash-binary geothermal power plants. Furthermore, in binary cycles choosing the best and practical working fluid is an important factor. Hence three different types of working fluids have been used to find the best one that gives maximum thermal and exergy efficiency of combined flash-binary geothermal power plants. According to results, the maximum thermal and exergy efficiencies both achieved in ORC with an IHE and the effective working fluid is R123.

Geothermal Power Cycle Analysis for Commercial Applicability Using Sequestered Supercritical CO2 as a Heat Transfer or Working Fluid

2011 ◽  
Author(s):  
Brian Janke ◽  
Thomas Kuehn
Keyword(s):  
Heat Transfer ◽  
Binary System ◽  
Power Plants ◽  
Power Production ◽  
Operating Conditions ◽  
Heat Transfer Fluid ◽  
Working Fluid ◽  
Direct System ◽  
Geothermal Power ◽  
The Impact

Thermodynamic analysis has been conducted for geothermal power cycles using a portion of deep ground sequestered CO2 as the working fluid. This allows energy production from much shallower depths and in geologic areas with much lower temperature gradients than those of current geothermal systems. Two different system designs were analyzed for power production with varying reservoir parameters, including reservoir depth, temperature, and CO2 mass flow rate. The first design is a direct single-loop system with the CO2 run directly through the turbine. This system was found to provide higher system efficiency and power production, however design complications such as the need for high pressure turbines, two-phase flow through the turbine and the potential for water-CO2 brine mixtures, could require the use of numerous custom components, driving up the cost. The second design is a binary system using CO2 as the heat transfer fluid to supply thermal energy to an Organic Rankine Cycle (ORC). While this system was found to have slightly less power production and efficiency than the direct system, it significantly reduces the impact of design complications associated with the direct system. This in turn reduces the necessity for certain custom components, thereby reducing system cost. While performance of these two systems is largely dependent on location and operating conditions, the binary system is likely applicable to a larger number of sites and will be more cost effective when used in combination with current off-the-shelf ORC power plants.

Specified Maintenance of Steam Turbines in Geothermal Power Plants

2013 ◽  
Author(s):  
Almar Gunnarsson ◽  
Ari Elisson ◽  
Magnus Jonsson ◽  
Runar Unnthorsson
Keyword(s):  
Power Plant ◽  
Condition Monitoring ◽  
Power Plants ◽  
Maintenance Management ◽  
Working Fluid ◽  
Steam Turbines ◽  
Effect Analysis ◽  
Geothermal Power Plant ◽  
Management Procedures ◽  
Geothermal Power

In a geothermal power plant the working fluid used to produce electricity is often wet steam composed of corrosives chemicals. In this situation, more frequent maintenance of the equipment is required. By constructing an overview for maintenance in geothermal power plants and how it can be done with minimum power outages and cost, the geothermal energy can be made more competitive in comparison to other energy resources. This work is constructed as a part of a project, which has the aim of mapping the maintenance management system at the Hellisheiði geothermal power plant in Iceland. The object of the project is to establish Reliability Centered Maintenance (RCM) program for Hellisheiði power plant that can be utilized to establish efficient maintenance management procedures. The focus of this paper is to examine the steam turbines, which have been defined as one of the main subsystems of the power plant at Hellisheiði. A close look will be taken at the maintenance needed for the steam turbines by studying for example which parts break down and how frequently they fail. The local ability of the staff to repair or construct turbine parts on-site is explored. The paper explores how the maintenance and condition monitoring is carried out today and what can be improved in order to reduce cost. The data collected is analyzed using Failure Mode and Effect Analysis (FMEA) in order to get an overview of the system and to help organizing maintenance and condition monitoring of the power plant in the future. Furthermore, the paper presents an overview of currently employed maintenance methods at Hellisheiði power plant, the domestic ability for maintaining and repairing steam turbines and the power plant’s need for repairs. The results show that the need for maintenance of the geothermal steam turbines at Hellisheiði power plant is high and that on-site maintenance and repairs can decrease the cost.

Recommendations for Energy–Water–Food Nexus Problems

2015 ◽  
Vol 137 (3) ◽  
Author(s):  
Kaufui Vincent Wong ◽  
Charles Pecora
Keyword(s):  
Water Scarcity ◽  
Power Plants ◽  
Fossil Fuel ◽  
Solar Power ◽  
Combined Cycle ◽  
Sub Saharan Africa ◽  
Working Fluid ◽  
Solar Panels ◽  
Geothermal Power ◽  
Sub Saharan

Around the world, climate change has brought about seemingly more incidences of climate extremes. Sub-Saharan Africa is a prime example of a region with many countries suffering from water scarcity. Water scarcity is quite possibly the most important issue that exists, seeing as it is the one essential resource for humans and all other life. Water scarcity in this region is somewhat ironic because of the numerous freshwater rivers that run throughout the region. The main reason for this water problem is the mismanagement and lack of energy required to redistribute the water. The water issue is inevitably linked to both energy resources and food resources. Water is the basis for all agriculture and is required for livestock. Water is also needed for almost any type of energy conversion. In a fossil fuel power plant, water is both the working fluid of the system and the coolant used in the condenser. In dams, the potential stored in flowing water is the basis of the creation of energy. Water, conversely, requires power to be transported and treated for drinking and agriculture. Sub-Saharan Africa has nearly maximized the energy of its large rivers, thus new sources of energy must be implemented to help with the energy crisis. A couple of the possibilities are fossil fuel power plants, geothermal power plants, and solar panels. Solar panels require a large amount of capital to build, but are nearly free to maintain, and can be cheaper in the long run. Solar power is an undeniably renewable resource and does not adversely affect the environment. Solar power can be utilized both for electricity generation and for irrigation and cooking in remote communities. Geothermal power plants utilize the potential stored in the earth's crust in places with volcanic activity. East Africa has an especially large potential for geothermal energy due to its many volcanoes. As for thermal power plants, combined cycle power plants paired with a salt water cooling system would greatly improve efficiency and drastically decrease water usage. By replacing Rankine cycle power plants that are used in most of Sub-Saharan Africa with either combined cycle plants or gas cycle plants, efficiencies would improve and far less water for cooling would be used in the system.

scholarly journals Different Geothermal Power Cycle Configurations Cost Estimation Models

2021 ◽  
Vol 13 (20) ◽  
pp. 11133
Author(s):  
Moein Shamoushaki ◽  
Giampaolo Manfrida ◽  
Lorenzo Talluri ◽  
Pouriya H. Niknam ◽  
Daniele Fiaschi
Keyword(s):  
Cost Estimation ◽  
Power Plants ◽  
Fluid Pressure ◽  
Influential Factors ◽  
Working Fluid ◽  
Cost Models ◽  
Geothermal Fluid ◽  
Total Cost ◽  
Power Cycle ◽  
Geothermal Power

An economic assessment of different geothermal power cycle configurations to generate cost models is conducted in this study. The thermodynamic and exergoeconomic modeling of the cycles is performed in MATLAB coupled to Refprop. The models were derived based on robust multivariable regression to minimize the residuals by using the genetic algorithm. The cross-validation approach is applied to determine a dataset to examine the model in the training phase for validation and reduce the overfitting problem. The generated cost models are the total cost rate, the plant's total cost, and power generation cost. The cost models and the relevant coefficients are generated based on the most compatibilities and lower error. The results showed that one of the most influential factors on the ORC cycle is the working fluid type, which significantly affects the final economic results. Other parameters that considerably impact economic models results, of all configurations, are geothermal fluid pressure and temperature and inlet pressure of turbine. Rising the geothermal fluid mass flow rate has a remarkable impact on cost models as the capacity and size of equipment increases. The generated cost models in this study can estimate the mentioned cost parameters with an acceptable deviation and provide a fast way to predict the total cost of the power plants.

Organic Working Fluids for a Combined Power and Cooling Cycle

2005 ◽  
Vol 127 (2) ◽  
pp. 125-130 ◽  
Author(s):  
Sanjay Vijayaraghavan ◽  
D. Y. Goswami
Keyword(s):  
Power Plants ◽  
Thermodynamic Cycle ◽  
Working Fluid ◽  
Water Mixture ◽  
Heat Sources ◽  
Absorption Refrigeration ◽  
Ammonia Water ◽  
Working Fluids ◽  
Fluid Mixtures ◽  
Advantages And Disadvantages

A new thermodynamic cycle has been developed for the simultaneous production of power and cooling from low-temperature heat sources. The proposed cycle combines the Rankine and absorption refrigeration cycles, providing power and cooling as useful outputs. Initial studies were performed with an ammonia-water mixture as the working fluid in the cycle. This work extends the application of the cycle to working fluids consisting of organic fluid mixtures. Organic working fluids have been used successfully in geothermal power plants, as working fluids in Rankine cycles. An advantage of using organic working fluids is that the industry has experience with building turbines for these fluids. A commercially available optimization program has been used to maximize the thermodynamic performance of the cycle. The advantages and disadvantages of using organic fluid mixtures as opposed to an ammonia-water mixture are discussed. It is found that thermodynamic efficiencies achievable with organic fluid mixtures, under optimum conditions, are lower than those obtained with ammonia-water mixtures. Further, the refrigeration temperatures achievable using organic fluid mixtures are higher than those using ammonia-water mixtures.

scholarly journals Selected aspects of operation of supercritical (transcritical) organic Rankine cycle

2015 ◽  
Vol 36 (2) ◽  
pp. 85-103 ◽  
Author(s):  
Szymon Mocarsk ◽  
Aleksandra Borsukiewicz-Gozdur
Keyword(s):  
Power Plant ◽  
Power Plants ◽  
Organic Rankine Cycle ◽  
Thermodynamic Cycle ◽  
Rankine Cycle ◽  
Working Fluid ◽  
Two Phase ◽  
Medium Temperature ◽  
Water Steam ◽  
Supercritical Parameters

AbstractThe paper presents a literature review on the topic of vapour power plants working according to the two-phase thermodynamic cycle with supercritical parameters. The main attention was focused on a review of articles and papers on the vapour power plants working using organic circulation fluids powered with low- and medium-temperature heat sources. Power plants with water-steam cycle supplied with a high-temperature sources have also been shown, however, it has been done mainly to show fundamental differences in the efficiency of the power plant and applications of organic and water-steam cycles. Based on a review of available literature references a comparative analysis of the parameters generated by power plants was conducted, depending on the working fluid used, the type and parameters of the heat source, with particular attention to the needs of power plant internal load.

scholarly journals Criteria for the Selection of Working Fluids for Geothermal Power Plants: A Case Study in Spain

Proceedings ◽  
2018 ◽  
Vol 2 (23) ◽  
pp. 1424
Author(s):  
Antonio Luis Marqués Sierra ◽  
Noe Anes Garcia
Keyword(s):  
Power Plant ◽  
Power Plants ◽  
Working Fluid ◽  
Design Decision ◽  
Working Fluids ◽  
Geothermal Power Plant ◽  
Binary Geothermal Power Plant ◽  
Geothermal Power ◽  
Selection Of

An important key in binary geothermal power plant is the selection of working fluid. This design decision has great implications for the operation of this power plant. While there are many options available for working fluids, there are also many restrictions on the selection that relate to the thermodynamic properties of fluids, as well as considerations of salt, safety and environmental impact.

Organic Working Fluids for a Combined Power and Cooling Cycle

2003 ◽  
Author(s):  
Sanjay Vijayaraghavan ◽  
D. Y. Goswami
Keyword(s):  
Power Plants ◽  
Thermodynamic Cycle ◽  
Working Fluid ◽  
Water Mixture ◽  
Heat Sources ◽  
Absorption Refrigeration ◽  
Ammonia Water ◽  
Working Fluids ◽  
Fluid Mixtures ◽  
Advantages And Disadvantages

A new thermodynamic cycle has been developed for the simultaneous production of power and cooling from low temperature heat sources. The proposed cycle combines the Rankine and absorption refrigeration cycles, providing power and cooling as useful outputs. Initial studies were performed with an ammonia-water mixture as the working fluid in the cycle. This work extends the application of the cycle to working fluids consisting of organic fluid mixtures. Organic working fluids have been used successfully in geothermal power plants, as working fluids in Rankine cycles. An advantage of using organic working fluids is that the industry has experience with building turbines for these fluids. A commercially available optimization program has been used to maximize the thermodynamic performance of the cycle. The advantages and disadvantages of using organic fluid mixtures as opposed to an ammonia-water mixture are discussed. It is found that thermodynamic efficiencies achievable with organic fluid mixtures, under optimum conditions, are lower than those obtained with ammonia-water mixtures. Further, the refrigeration temperatures achievable using organic fluid mixtures are higher than those using ammonia-water mixtures.

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