Download or read book Power Conversion System Design for Supercritical Carbon Dioxide Cooled Indirect Cycle Nuclear Reactors written by Jonathan Paul Gibbs and published by . This book was released on 2008 with total page 207 pages. Available in PDF, EPUB and Kindle. Book excerpt: (Cont.) Peak cycle pressure is also an important parameter affecting cycle efficiency, although to a smaller extent than turbine inlet temperature. Higher pressure gives higher efficiency, but this gradually saturates around 28 MPa. Other sensitivity studies included turbomachinery performance, cooling water temperature, and heat exchanger fouling and plugging The reference parameters chosen are a 650°C turbine inlet temperature and 20 MPa peak cycle pressure (compressor outlet) because they reach a high thermodynamic efficiency (~/~47-48%) while staying within materials limitations. In order to couple the cycle to many of the Generation IV nuclear reactors a second reference case was chosen with a turbine inlet temperature of 550°C and a peak cycle pressure of 20 MPa.

Download or read book Optimization and Comparison of Direct and Indirect Supercritical Carbon Dioxide Power Plant Cycles for Nuclear Applications written by and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: There have been a number of studies involving the use of gases operating in the supercritical mode for power production and process heat applications. Supercritical carbon dioxide (CO2) is particularly attractive because it is capable of achieving relatively high power conversion cycle efficiencies in the temperature range between 550 C and 750 C. Therefore, it has the potential for use with any type of high-temperature nuclear reactor concept, assuming reactor core outlet temperatures of at least 550 C. The particular power cycle investigated in this paper is a supercritical CO2 Recompression Brayton Cycle. The CO2 Recompression Brayton Cycle can be used as either a direct or indirect power conversion cycle, depending on the reactor type and reactor outlet temperature. The advantage of this cycle when compared to the helium Brayton cycle is the lower required operating temperature; 550 C versus 850 C. However, the supercritical CO2 Recompression Brayton Cycle requires an operating pressure in the range of 20 MPa, which is considerably higher than the required helium Brayton cycle operating pressure of 8 MPa. This paper presents results of analyses performed using the UniSim process analyses software to evaluate the performance of both a direct and indirect supercritical CO2 Brayton Recompression cycle for different reactor outlet temperatures. The direct supercritical CO2 cycle transferred heat directly from a 600 MWt reactor to the supercritical CO2 working fluid supplied to the turbine generator at approximately 20 MPa. The indirect supercritical CO2 cycle assumed a helium-cooled Very High Temperature Reactor (VHTR), operating at a primary system pressure of approximately 7.0 MPa, delivered heat through an intermediate heat exchanger to the secondary indirect supercritical CO2 Brayton Recompression cycle, again operating at a pressure of about 20 MPa. For both the direct and indirect cycles, sensitivity calculations were performed for reactor outlet temperature between 550 C and 850 C. The UniSim models used realistic component parameters and operating conditions to model the complete reactor and power conversion systems. CO2 properties were evaluated, and the operating ranges of the cycles were adjusted to take advantage of the rapidly changing properties of CO2 near the critical point. The results of the analyses showed that, for the direct supercritical CO2 power cycle, thermal efficiencies in the range of 40 to 50% can be achieved. For the indirect supercritical CO2 power cycle, thermal efficiencies were approximately 10% lower than those obtained for the direct cycle over the same reactor outlet temperature range.

Download or read book Evaluation and Optimization of a Supercritical Carbon Dioxide Power Conversion Cycle for Nuclear Applications written by and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: There have been a number of studies involving the use of gases operating in the supercritical mode for power production and process heat applications. Supercritical carbon dioxide (CO2) is particularly attractive because it is capable of achieving relatively high power conversion cycle efficiencies in the temperature range between 550°C and 750°C. Therefore, it has the potential for use with any type of high-temperature nuclear reactor concept, assuming reactor core outlet temperatures of at least 550°C. The particular power cycle investigated in this paper is a supercritical CO2 Recompression Brayton Cycle. The CO2 Recompression Brayton Cycle can be used as either a direct or indirect power conversion cycle, depending on the reactor type and reactor outlet temperature. The advantage of this cycle when compared to the helium Brayton Cycle is the lower required operating temperature; 550°C versus 850°C. However, the supercritical CO2 Recompression Brayton Cycle requires an operating pressure in the range of 20 MPa, which is considerably higher than the required helium Brayton cycle operating pressure of 8 MPa. This paper presents results of analyses performed using the UniSim process analyses software to evaluate the performance of the supercritical CO2 Brayton Recompression Cycle for different reactor outlet temperatures. The UniSim model assumed a 600 MWt reactor power source, which provides heat to the power cycle at a maximum temperature of between 550°C and 750°C. The UniSim model used realistic component parameters and operating conditions to model the complete power conversion system. CO2 properties were evaluated, and the operating range for the cycle was adjusted to take advantage of the rapidly changing conditions near the critical point. The UniSim model was then optimized to maximize the power cycle thermal efficiency at the different maximum power cycle operating temperatures. The results of the analyses showed that power cycle thermal efficiencies in the range of 40 to 50% can be achieved.

Download or read book A Supercritical Carbon Dioxide Cycle for Next Generation Nuclear Reactors written by Vaclav Dostal and published by . This book was released on 2004 with total page 317 pages. Available in PDF, EPUB and Kindle. Book excerpt: A systematic, detailed major component and system design evaluation and multiple parameter optimization under practical constraints has been performed of the family of supercritical CO2 Brayton power cycles for application to advanced nuclear reactors. The recompression cycle is shown to excel with respect to simplicity, compactness, cost and thermal efficiency. The main advantage of the supercritical CO2 cycle is comparable efficiency with the helium Brayton cycle at significantly lower temperature (550°C vs. 850 0C), but higher pressure (20 MPa vs. 8 MPa). The supercritical CO2 cycle is well suited to any type of nuclear reactor with core outlet temperature above [approx.] 500 0C in either direct or indirect versions. By taking advantage of the abrupt property changes near the critical point of CO2 the compression work can be reduced, which results in a significant efficiency improvement. However, a real gas cycle requires much more careful optimization than an ideal gas Brayton cycle. Previous investigations by earlier authors were systematized and refined in the present work to survey several different CO2 cycle layouts. Inter- cooling, re-heating, re-compressing and pre-compressing were considered. The recompression cycle was found to yield the highest efficiency, while still retaining simplicity. Inter-cooling is not attractive for this type of cycle as it offers a very modest efficiency improvement. Re-heating has a better potential, but it is applicable only to indirect cycles. Economic analysis of the benefit of re-heating for the indirect cycle showed that using more than one stage of re-heat is economically unattractive.

Download or read book Byudviklingsplan for Frederikssund egnen written by and published by . This book was released on with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Handbook of Generation IV Nuclear Reactors written by Igor Pioro and published by Woodhead Publishing. This book was released on 2022-12-07 with total page 1112 pages. Available in PDF, EPUB and Kindle. Book excerpt: Handbook of Generation IV Nuclear Reactors, Second Edition is a fully revised and updated comprehensive resource on the latest research and advances in generation IV nuclear reactor concepts. Editor Igor Pioro and his team of expert contributors have updated every chapter to reflect advances in the field since the first edition published in 2016. The book teaches the reader about available technologies, future prospects and the feasibility of each concept presented, equipping them users with a strong skillset which they can apply to their own work and research. Provides a fully updated, revised and comprehensive handbook dedicated entirely to generation IV nuclear reactors Includes new trends and developments since the first publication, as well as brand new case studies and appendices Covers the latest research, developments and design information surrounding generation IV nuclear reactors

Download or read book Fundamentals and Applications of Supercritical Carbon Dioxide SCO2 Based Power Cycles written by Klaus Brun and published by Woodhead Publishing. This book was released on 2017-01-09 with total page 464 pages. Available in PDF, EPUB and Kindle. Book excerpt: Fundamentals and Applications of Supercritical Carbon Dioxide (SCO2) Based Power Cycles aims to provide engineers and researchers with an authoritative overview of research and technology in this area. Part One introduces the technology and reviews the properties of SCO2 relevant to power cycles. Other sections of the book address components for SCO2 power cycles, such as turbomachinery expanders, compressors, recuperators, and design challenges, such as the need for high-temperature materials. Chapters on key applications, including waste heat, nuclear power, fossil energy, geothermal and concentrated solar power are also included. The final section addresses major international research programs. Readers will learn about the attractive features of SC02 power cycles, which include a lower capital cost potential than the traditional cycle, and the compounding performance benefits from a more efficient thermodynamic cycle on balance of plant requirements, fuel use, and emissions. Represents the first book to focus exclusively on SC02 power cycles Contains detailed coverage of cycle fundamentals, key components, and design challenges Addresses the wide range of applications of SC02 power cycles, from more efficient electricity generation, to ship propulsion

Download or read book Nuclear Air Brayton Combined Cycle Power Conversion Design Physical Performance Estimation and Economic Assessment written by Charalampos Andreades and published by . This book was released on 2015 with total page 117 pages. Available in PDF, EPUB and Kindle. Book excerpt: The combination of an increased demand for electricity for economic development in parallel with the widespread push for adoption of renewable energy sources and the trend toward liberalized markets has placed a tremendous amount of stress on generators, system operators, and consumers. Non-guaranteed cost recovery, intermittent capacity, and highly volatile market prices are all part of new electricity grids. In order to try and remediate some of these effects, this dissertation proposes and studies the design and performance, both physical and economic, of a novel power conversion system, the Nuclear Air-Brayton Combined Cycle (NACC). The NACC is a power conversion system that takes a conventional industrial frame type gas turbine, modifies it to accept external nuclear heat at 670°C, while also maintaining its ability to co-fire with natural gas to increase temperature and power output at a very quick ramp rate. The NACC addresses the above issues by allowing the generator to gain extra revenue through the provision of ancillary services in addition to energy payments, the grid operator to have a highly flexible source of capacity to back up intermittent renewable energy sources, and the consumer to possibly see less volatile electricity prices and a reduced probability of black/brown outs. This dissertation is split into six sections that delve into specific design and economic issues related to the NACC. The first section describes the basic design and modifications necessary to create a functional externally heated gas turbine, sets a baseline design based upon the GE 7FB, and estimates its physical performance under nominal conditions. The second section explores the off-nominal performance of the NACC and characterizes its startup and shutdown sequences, along with some of its safety measures. The third section deals with the power ramp rate estimation of the NACC, a key performance parameter in a renewable-heavy grid that needs flexible capacity. The fourth section lays out the cost structure of the Mk1 Pebble-Bed Fluoride-salt-cooled High-temperature Reactor (FHR) with the NACC, since the NACC cannot be treated separately from its heat source. The fifth section evaluates the cost structure of a twelve-unit Mk1 FHR and NACC, including capital construction costs, operating costs, fuel and decommissioning costs in bottom up methodology. The sixth section proposes alternative NACC configurations and scales (mobile, remote NACC) or alternative power cycles to the NACC that can be coupled to the FHR (supercritical carbon dioxide Brayton cycle).

Download or read book Development and Application of a Steady State Code for Supercritical Carbon Dioxide Cycles written by David Michael Legault and published by . This book was released on 2006 with total page 126 pages. Available in PDF, EPUB and Kindle. Book excerpt: The supercritical CO2 power conversion system is of interest for advanced nuclear reactor applications because the same efficiencies are obtained as for the most developed of the closed gas-turbine cycles (helium-Brayton), but at lower temperatures and higher pressures. The original in-house code, named CYCLES, could potentially be used by others who are researching the S-CO2 cycle, but it has its shortcomings. In particular, CYCLES does not factor in the pressure drops due to pipes and plena. Also, for new users, it takes a significant amount of time to fully understand how to use the code. The objectives of this thesis were to modify CYCLES to ensure that pipe and plena effects were included, and to improve the readability and functionality of the code. Changes to CYCLES are included in the rewritten code, named CYCLES II, and are also documented in this thesis. Furthermore, documentation of the program input and output is given, along with a flow chart of the algorithm logic. Two applications of the code are provided to show the effect of the pipes and plena on cycle performance. In comparing the cycle efficiency with and without the effects of the pipes and plena, for a 300 MWe S-CO2 Brayton power conversion system, the results indicate that the net cycle efficiency drops from 49% to 45% when pipes and plena of reasonable dimensions are included in the calculations. The losses are dominated by the low pressure pipe and plena segments. However, the effects of the pipes and plena on cycle efficiency are not characteristic of the S-CO2 cycle only. All Brayton cycles have this same issue, and the effects are worse for the helium-Brayton cycle because it operates at lower pressures.

Download or read book Balance of Plant Analysis for High Temperature Gas Cooled Reactors written by Chunyun Wang and published by LAP Lambert Academic Publishing. This book was released on 2009-09 with total page 220 pages. Available in PDF, EPUB and Kindle. Book excerpt: As a Generation IV nuclear system, the High Temperature Gas Cooled Reactor (HTGR) desires a gas turbine cycle (Brayton cycle) as the power conversion system for it to achieve economic competitiveness. The availability of compact heat exchangers and helium turbo-machinery are thus the critical enabling technology for the gas turbine cycle. This book performs an extensive study on the power conversion system: design constraints, cycle variations, compact heat exchangers, high efficiency helium turbo-machinery and cycle control methods. A detailed steady state and dynamic model is developed for studying the cycle design in terms of efficiency and controllability. An indirect closed helium cycle design is developed in this book by identifying key advances in the technology that could reasonably be expected to be achieved with limited R&D. The modular conceptual design for the intermediate heat exchanger (IHX) and recuperator is also performed.

Download or read book Nuclear Science Abstracts written by and published by . This book was released on 1973 with total page 1132 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Experimental Investigation of Critical Flow of Supercritical Carbon Dioxide written by Guillaume Paul H. Mignot and published by . This book was released on 2008 with total page 206 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Modeling the Supercritical Carbon Dioxide Brayton Cycle with Recompression written by and published by . This book was released on 2014 with total page 155 pages. Available in PDF, EPUB and Kindle. Book excerpt: Supercritical carbon dioxide (SCO2) power cycles show promise for a wide range of applications, such as concentrating solar power, next-generation nuclear reactors, and waste-heat recovery. Models capable of predicting the design-point, off-design, and part-load performance of SCO2 power cycles are necessary for evaluating cycle designs. These models should be flexible in order to accommodate the range of designs under consideration and computationally efficient in order to enable timely optimization studies, possibly while considering cycle performance on an annual or life-cycle basis. This document reports on the development of a modeling framework that accommodates these requirements and is capable of predicting the performance of recuperated and recompression cycle configurations. The modeling framework is in Fortran and is flexible with respect to component-level specifics, such as the type of compressor used in the cycle or the method used to represent the off-design performance of the turbine. Optimization routines are integrated into the models, allowing exploration of optimal component and system designs or optimal operating strategies for a given system design. The optimal design-point and off-design performance of various cycle designs is predicted using turbomachinery models based on the radial compressors and turbines that are currently being investigated by Sandia National Laboratory for use in SCO2 applications. A range of heat rejection (low-side) temperatures are considered and results indicate that operating the cycles at warmer low-side temperatures requires a corresponding increase in low-side pressure in order to maximize thermal efficiency. The relationship between low-side temperature and pressure suggests that inventory control (i.e., actively controlling the low-side pressure) is a favorable control mechanism, especially if the power plant is expected to operate away from its design point for significant periods of time. For cycles designed to operate at warmer heat rejection temperatures (e.g., a dry-cooled design in an arid climate), the benefits of recompression are reduced and a simple recuperated cycle may be favorable. The optimal SCO2 Brayton cycle design depends on the application being considered, and the developed modeling framework provides the consistent performance predictions that are required for further application-specific analyses.

Download or read book Optimized Core Design of a Supercritical Carbon Dioxide cooled Fast Reactor written by Christopher Stanley Handwerk and published by . This book was released on 2007 with total page 367 pages. Available in PDF, EPUB and Kindle. Book excerpt: (Cont.) Alternative cores using traditional pin-type fuel and innovative Internally-Cooled Annular Fuel (ICAF) have also been evaluated. While the performance of the TID core is superior, the results of the pin-type core show promise, pending design modification and relaxation of the imposed core pressure drop constraint, which would come at the expense of cycle efficiency and increased decay heat removal power requirements. Nevertheless, no improvement would be able to achieve a sustainable core (i.e. conversion ratio=l) using oxide fuel without the use of external blankets for pin fuel, even without the use of diluent in the fuel. A comprehensive comparison of the thermal hydraulic and neutronic performance of TID fuel with that of the traditional pin-type fuel, as well as with the ICAF is also made, showing the fundamental reasons for their difference in performance.

Download or read book Organic Rankine Cycle ORC Power Systems written by Ennio Macchi and published by Woodhead Publishing. This book was released on 2016-08-24 with total page 700 pages. Available in PDF, EPUB and Kindle. Book excerpt: Organic Rankine Cycle (ORC) Power Systems: Technologies and Applications provides a systematic and detailed description of organic Rankine cycle technologies and the way they are increasingly of interest for cost-effective sustainable energy generation. Popular applications include cogeneration from biomass and electricity generation from geothermal reservoirs and concentrating solar power installations, as well as waste heat recovery from gas turbines, internal combustion engines and medium- and low-temperature industrial processes. With hundreds of ORC power systems already in operation and the market growing at a fast pace, this is an active and engaging area of scientific research and technical development. The book is structured in three main parts: (i) Introduction to ORC Power Systems, Design and Optimization, (ii) ORC Plant Components, and (iii) Fields of Application. Provides a thorough introduction to ORC power systems Contains detailed chapters on ORC plant components Includes a section focusing on ORC design and optimization Reviews key applications of ORC technologies, including cogeneration from biomass, electricity generation from geothermal reservoirs and concentrating solar power installations, waste heat recovery from gas turbines, internal combustion engines and medium- and low-temperature industrial processes Various chapters are authored by well-known specialists from Academia and ORC manufacturers

Download or read book Applications of Supercritical Carbon Dioxide Based Power Cycles written by and published by . This book was released on 2018-05 with total page 376 pages. Available in PDF, EPUB and Kindle. Book excerpt: Supercritical CO2 (sCO2) cycles are being considered for future fossil energy systems. These sCO2 systems deliver the prospect of improved efficiency combined with smaller turbo -machinery size compared to a traditional Rankine steam system if operated at turbine inlet temperatures up to 760°C. Supercritical CO2 cycles have been investigated since the 1960s, but technical limitations, both computational and physical, prevented major strides on the subject until the turn of the millennium. Since then, numerous studies have investigated and conceptualized various sCO2 cycles: as standalone power cycles for nuclear applications, in concentrated solar power plants or for waste heat recovery. Many of these studies were conducted using established performance simulation tools such as NPSS, which were expanded in their functionality through supercritical CO2 fluid property functions.Fundamentals and Applications of Supercritical Carbon Dioxide (sCO2) Based Power Cycles provides up-to-date information of research and technology in this field. This book addresses components for sCO2 power cycles, such as turbomachinery expanders, compressors, recuperators, and design challenges, such as the need for high-temperature materials. The attractive features of sC02 power cycles are addressed. The supercritical CO2 (sCO2) Brayton cycle has recently been gaining a lot of attention for application to next generation nuclear reactors. The advantages of the sCO2 cycle are high efficiency in the mild turbine inlet temperature region and a small physical footprint with a simple layout, compact turbomachinery, and heat exchangers. Currently sCO2 cycles are being investigated primarily for stationary power applications, but their high power density and efficiency, even for modest peak cycle temperatures, makes them credible bottoming cycle options for aero engine applications. To successfully utilize the high reactor outlet temperature, interest in alternative power conversion systems is also increasing. The steam Rankine cycle and gas turbine systems have been utilized by large size power plants for several decades.This book will appeal to students, practitioners, as well as researchers dealing with this field.

Download or read book Improving Fuel Cycle Design and Safety Characteristics of a Gas Cooled Fast Reactor written by Willem Frederik Geert van Rooijen and published by IOS Press. This book was released on 2006 with total page 160 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Generation IV Forum is an international nuclear energy research initiative aimed at developing the fourth generation of nuclear reactors, envisaged to enter service halfway the 21st century. One of the Generation IV reactor systems is the Gas Cooled Fast Reactor (GCFR), the subject of study in this thesis. The Generation IV reactor concepts should improve all aspects of nuclear power generation. Within Generation IV, the GCFR concept specifically targets sustainability of nuclear power generation. The Gas Cooled Fast Reactor core power density is high in comparison to other gas cooled reactor concepts. Like all nuclear reactors, the GCFR produces decay heat after shut down, which has to be transported out of the reactor under all circumstances. The layout of the primary system therefore focuses on using natural convection Decay Heat Removal (DHR) where possible, with a large coolant fraction in the core to reduce friction losses.