The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
This paper presents part-load evaluation of a natural gas-fired chemical looping combustion (CLC) combined cycle with CO 2 capture. The novel combined cycle employs an air-based gas turbine, a CO 2 -turbine and a steam turbine cycle. In this combined cycle, the CLC reactors replace combustion chamber of the gas turbine. The proposed combined cycle has a net plant efficiency of about...
A numerical study of a thermodynamic cycle is described: solar energy powered Rankine cycle using supercritical carbon dioxide as the working fluid for combined power and heat production. A model is developed to predict the cycle performance. Experimental data is used to verify the numerical formulation. Of interest in the present study is the thermodynamic cycle of 0.3–1.0kW power generation and...
Due to the growing concern for global warming, the EU25 have implemented the European Union Greenhouse Gas Emission Trading Scheme (EU ETS). In the first trading period (2005–2007), part of the targeted GHG emission reductions presumably will have to result from a switch from coal fired electricity generation to gas fired electricity generation. It is possible to calculate the allowance cost necessary...
A cost-effective optimum design criterion for Organic Rankine power cycles utilizing low-temperature geothermal heat sources is presented. The ratio of the total heat exchanger area to net power output is used as the objective function and was optimized using the steepest descent method. Evaporation and condensation temperatures, geothermal and cooling water velocities are varied in the optimization...
Recent estimates and forecasts of the oil, gas, coal resources and their reserve/production ratio, nuclear and renewable energy potential, and energy uses are surveyed. The impact of the rapidly growing economies of the highly populated countries, as well as of the concern about global warming, are presented and assessed. A brief discussion of the status and prospects of fossil, nuclear and renewable...
The increasing costs of fuel and operation of thermal power generating units warrant development of optimization methodologies for economic dispatch (ED) problems. Optimization methodologies that are based on meta-heuristic procedures could assist power generation policy analysts to achieve the goal of minimizing the generation costs. In this context, the objective of this study is to present a novel...
In this paper, a computational study of the influence of the heat exchangers' thermal resistances (in both the hot and cold side) on the efficiency of a thermoelectric generation device has been carried out.For this purpose, a computational model has been developed. This model uses the numerical method of finite differences to simulate the performance of the thermoelectric generation system, including...
A novel liquefied natural gas (LNG) fueled power plant is proposed, which has virtually zero CO 2 and other emissions and a high efficiency. The plant operates as a subcritical CO 2 Rankine-like cycle. Beside the power generation, the system provides refrigeration in the CO 2 subcritical evaporation process, thus it is a cogeneration system with two valued products. By coupling...
Recent estimates and forecasts of the oil, gas, and coal resources and their reserve/production ratio, nuclear and renewable energy potential, and energy uses are surveyed. A brief discussion of the status and prospects of fossil, nuclear and renewable energy use, and of power generation (including hydrogen, fuel cells, micropower systems, and the futuristic concept of generating power in space for...
In this series of two articles, the concepts and approaches of environomic (thermodynamic, economic and environmental) performance ‘Typification’ of power generation technologies (Part I) and of combined heat and power (CHP) cogeneration technologies (Part II) in the context of CO 2 abatement are introduced. A methodology is then proposed for a flexible and fast project based power or CHP...
Recent estimates and forecasts of the oil, gas, coal resources and their reserve/production ratio, nuclear and renewable energy potential, and energy uses are surveyed. A brief discussion of the status, sustainability (economic, environmental and social impact), and prospects of fossil, nuclear and renewable energy use, and of power generation (including hydrogen, fuel cells, micropower systems, and...
The growth of power generation in China since the 1980s has been reviewed by analyzing the relationship between demand and supply of power, the increasing in installed capacity, and the variations in power-resource structure. Currently, the power generation from pulverized coal (PC) is dominant in the China's power industry, with relevant PC-power-generation technologies being introduced in the past...
Thermodynamic formulation of efficiency of thermoelectric power generator is presented in terms of the slenderness ratio (X=(Ap/Lp)/(An/Ln)) and the external load parameter (Y=(RL)/(Ln/ke,nAn)). The optimum values of the slenderness ratio and external load parameter, maximizing the device efficiency, are formulated and predicted for several values of the thermal conductivity and the electrical conductivity...
Micro heat engines have attracted considerable interest in recent years for their potential exploitation as micro power sources in microsystems and portable devices. Thermodynamic modeling can predict the theoretical performance that can be potentially achieved by micro heat engine designs. An appropriate model can not only provide key information at the design stage but also indicate the potential...
Taking into account inner and external multi-irreversibilities, a complete numerical model of commercial thermoelectric generator with finned heat exchangers is established by combining thermodynamics with heat transfer theory. A significant novelty is that physical properties, geometric dimensions, temperature parameters and flow parameters are all considered in the model. The inner effects include...
This paper introduces the ECOS 2009 conference World Energy Panel, and presents the opening talk that briefly surveys the present (2009) situation in sustainable energy development. Recent (2008) estimates and forecasts of the oil, gas, coal resources and their reserve/production ratio, nuclear and renewable energy potential, and energy uses are surveyed. A brief discussion of the status, sustainability...
Demand for bioethanol has grown considerably over the last years. Even though Brazil has been producing ethanol from sugarcane on a large scale for decades, this industry is characterized by low energy efficiency, using a large fraction of the bagasse produced as fuel in the cogeneration system to supply the process energy requirements. The possibility of selling surplus electricity to the grid or...
A thermodynamic information system for diagnosis and prognosis of an existing power plant was developed. The system is based on an analytic approach that informs the current thermodynamic condition of all cycle components, as well as the improvement that can be obtained in the cycle performance by the elimination of the discovered anomalies. The effects induced by components anomalies and repairs...
The importance of the steam cycle design to maximize power generation is demonstrated using pinch analysis targeting techniques is demonstrated. Fixed steam headers, such as assumed in total site analysis, give no allowance for reheating before turbine expansion, which can be valuable to consider when optimizing the steam system for certain plant configurations. Additionally, previous work optimizes...
The main results of a theoretical work on the use of a low temperature heat source for power generation through a carbon dioxide transcritical power cycle are reported in this paper. The procedure for analyzing the behaviour of the proposed cycle consisted in modifying the input pressure to the turbine from 66 bar, maintained constant each evaluated temperature (60 °C, 90 °C, 120 °C and 150 °C) until...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.