Biomass energy conversion: conventional and advanced technologies

Energy Technology Data Exchange (ETDEWEB)

Young, B C; Hauserman, W B [Energy and Environmental Research Center, University of North Dakota, Grand Forks, ND (United States)

1995-12-01

Increasing interest in biomass energy conversion in recent years has focused attention on enhancing the efficiency of technologies converting biomass fuels into heat and power, their capital and operating costs and their environmental emissions. Conventional combustion systems, such as fixed-bed or grate units and entrainment units, deliver lower efficiencies (<25%) than modem coal-fired combustors (30-35%). The gasification of biomass will improve energy conversion efficiency and yield products useful for heat and power generation and chemical synthesis. Advanced biomass gasification technologies using pressurized fluidized-bed systems, including those incorporating hot-gas clean-up for feeding gas turbines or fuel cells, are being demonstrated. However, many biomass gasification processes are derivatives of coal gasification technologies and do not exploit the unique properties of biomass. This paper examines some existing and upcoming technologies for converting biomass into electric power or heat. Small-scale 1-30 MWe units are emphasized, but brief reference is made to larger and smaller systems, including those that bum coal-biomass mixtures and gasifiers that feed pilot-fuelled diesel engines. Promising advanced systems, such as a biomass integrated gasifier/gas turbine (BIG/GT) with combined-cycle operation and a biomass gasifier coupled to a fuel cell, giving cycle efficiencies approaching 50% are also described. These advanced gasifiers, typically fluid-bed designs, may be pressurized and can use a wide variety of biomass materials to generate electricity, process steam and chemical products such as methanol. Low-cost, disposable catalysts are becoming available for hot-gas clean-up (enhanced gas composition) for turbine and fuel cell systems. The advantages, limitations and relative costs of various biomass gasifier systems are briefly discussed. The paper identifies the best known biomass power projects and includes some information on proposed and

Biomass energy conversion: conventional and advanced technologies

International Nuclear Information System (INIS)

Young, B.C.; Hauserman, W.B.

1995-01-01

Increasing interest in biomass energy conversion in recent years has focused attention on enhancing the efficiency of technologies converting biomass fuels into heat and power, their capital and operating costs and their environmental emissions. Conventional combustion systems, such as fixed-bed or grate units and entrainment units, deliver lower efficiencies (<25%) than modem coal-fired combustors (30-35%). The gasification of biomass will improve energy conversion efficiency and yield products useful for heat and power generation and chemical synthesis. Advanced biomass gasification technologies using pressurized fluidized-bed systems, including those incorporating hot-gas clean-up for feeding gas turbines or fuel cells, are being demonstrated. However, many biomass gasification processes are derivatives of coal gasification technologies and do not exploit the unique properties of biomass. This paper examines some existing and upcoming technologies for converting biomass into electric power or heat. Small-scale 1-30 MWe units are emphasized, but brief reference is made to larger and smaller systems, including those that bum coal-biomass mixtures and gasifiers that feed pilot-fuelled diesel engines. Promising advanced systems, such as a biomass integrated gasifier/gas turbine (BIG/GT) with combined-cycle operation and a biomass gasifier coupled to a fuel cell, giving cycle efficiencies approaching 50% are also described. These advanced gasifiers, typically fluid-bed designs, may be pressurized and can use a wide variety of biomass materials to generate electricity, process steam and chemical products such as methanol. Low-cost, disposable catalysts are becoming available for hot-gas clean-up (enhanced gas composition) for turbine and fuel cell systems. The advantages, limitations and relative costs of various biomass gasifier systems are briefly discussed. The paper identifies the best known biomass power projects and includes some information on proposed and

Prospects of power conversion technology of direct-cycle helium gas turbine for MHTGR

International Nuclear Information System (INIS)

Li Yong; Zhang Zuoyi

1999-01-01

The modular high temperature gas cooled reactor (MHTGR) is a modern passively safe reactor. The reactor and helium gas turbine may be combined for high efficiency's power conversion, because MHTGR has high outlet temperature up to 950 degree C. Two different schemes are planed separately by USA and South Africa. the helium gas turbine methodologies adopted by them are mainly based on the developed heavy duty industrial and aviation gas turbine technology. The author introduces the differences of two technologies and some design issues in the design and manufacture. Moreover, the author conclude that directly coupling a closed Brayton cycle gas turbine concept to the passively safe MHTGR is the developing direction of MHTGR due to its efficiency which is much higher than that of using steam turbine

Condenser design for AMTEC power conversion

Science.gov (United States)

Crowley, Christopher J.

1991-01-01

The condenser and the electrodes are the two elements of an alkali metal thermal-to-electric conversion (AMTEC) cell which most greatly affect the energy conversion performance. A condenser is described which accomplishes two critical functions in an AMTEC cell: management of the fluid under microgravity conditions and optimization of conversion efficiency. The first function is achieved via the use of a controlled surface shape, along with drainage grooves and arteries to collect the fluid. Capillary forces manage the fluid in microgravity and dominate hydrostatic effects on the ground so the device is ground-testable. The second function is achieved via a smooth film of highly reflective liquid sodium on the condensing surface, resulting in minimization of parasitic heat losses due to radiation heat transfer. Power conversion efficiencies of 25 percent to 30 percent are estimated with this condenser using present technology for the electrodes.

Power Technologies Data Book 2003 Edition

Energy Technology Data Exchange (ETDEWEB)

Aabakken, J.

2004-06-01

The 2003 edition of this report, prepared by NREL's Energy Analysis Office, includes up-to-date information on power technologies, including complete technology profiles. The data book also contains charts on electricity restructuring, power technology forecasts and comparisons, electricity supply, electricity capability, electricity generation, electricity demand, prices, economic indicators, environmental indicators, conversion factors, and selected congressional questions and answers.

Power Technologies Energy Data Book - Fourth Edition

Energy Technology Data Exchange (ETDEWEB)

Aabakken, J.

2006-08-01

This report, prepared by NREL's Strategic Energy Analysis Center, includes up-to-date information on power technologies, including complete technology profiles. The data book also contains charts on electricity restructuring, power technology forecasts, electricity supply, electricity capability, electricity generation, electricity demand, prices, economic indicators, environmental indicators, and conversion factors.

Power Technologies Energy Data Book - Third Edition

Energy Technology Data Exchange (ETDEWEB)

Aabakken, J.

2005-04-01

This report, prepared by NREL's Energy Analysis Office, includes up-to-date information on power technologies, including complete technology profiles. The data book also contains charts on electricity restructuring, power technology forecasts, electricity supply, electricity capability, electricity generation, electricity demand, prices, economic indicators, environmental indicators, and conversion factors.

Geothermal Power Technologies

DEFF Research Database (Denmark)

Montagud, Maria E. Mondejar; Chamorro, C.R.

2017-01-01

Although geothermal energy has been widely deployed for direct use in locations with especial geologic manifestations, its potential for power generation has been traditionally underestimated. Recent technology developments in drilling techniques and power conversion technologies from low......-temperature heat resources are bringing geothermal energy to the spotlight as a renewable baseload energy option for a sustainable energy mix. Although the environmental impact and economic viability of geothermal exploitation must be carefully evaluated for each case, the use of deep low-temperature geothermal...... reservoirs could soon become an important contributor to the energy generation around the world....

Brayton-Cycle Power-Conversion Unit Tested With Ion Thruster

Science.gov (United States)

Hervol, David S.

2005-01-01

Nuclear electric propulsion has been identified as an enabling technology for future NASA space science missions, such as the Jupiter Icy Moons Orbiter (JIMO) now under study. An important element of the nuclear electric propulsion spacecraft is the power conversion system, which converts the reactor heat to electrical power for use by the ion propulsion system and other spacecraft loads. The electrical integration of the power converter and ion thruster represents a key technical challenge in making nuclear electric propulsion technology possible. This technical hurdle was addressed extensively on December 1, 2003, when a closed- Brayton-cycle power-conversion unit was tested with a gridded ion thruster at the NASA Glenn Research Center. The test demonstrated end-to-end power throughput and marked the first-ever coupling of a Brayton turbo alternator and a gridded ion thruster, both of which are candidates for use on JIMO-type missions. The testing was conducted at Glenn's Vacuum Facility 6, where the Brayton unit was installed in the 3-m-diameter vacuum test port and the ion thruster was installed in the 7.6-m-diameter main chamber.

Generator technology for HTGR power plants

International Nuclear Information System (INIS)

Lomba, D.; Thiot, D.

1997-01-01

Approximately 15% of the worlds installed capacity in electric energy production is from generators developed and manufactured by GEC Alsthom. GEC Alsthom is now working on the application of generators for HTGR power conversion systems. The main generator characteristics induced by the different HTGR power conversion technology include helium immersion, high helium pressure, brushless excitation system, magnetic bearings, vertical lineshaft, high reliability and long periods between maintenance. (author)

The state of the art of wind energy conversion systems and technologies: A review

International Nuclear Information System (INIS)

Cheng, Ming; Zhu, Ying

2014-01-01

Highlights: • This paper reviews the state of the art of wind energy conversion systems. • Different types of common wind energy conversion systems are classified and compared. • The four most popular MPPT control methods are reviewed and compared. • The latest development of wind energy conversion technologies is introduced. • Future trends of the wind energy conversion technologies are discussed. - Abstract: This paper gives a comprehensive review of the state of the art of wind energy conversion systems (WECS) and technologies, with an emphasis on wind power generator and control. First, different types of common WECSs are classified according to their features and drive train types. The WECSs are compared on the basis of the volume, weight, cost, efficiency, system reliability and fault ride through capability. The maximum power point tracking (MPPT) control, which aims to make the generator speed meet an optimum value to ensure the maximum energy yield, plays a key role in the variable speed WECSs. A comprehensive review and comparison of the four most popular MPPT control methods are carried out and improvements for each method are presented. Furthermore, the latest development of wind energy conversion technologies is introduced, such as the brushless doubly fed induction generator (BDFIG), the stator permanent magnet synchronous generators, the magnetic-geared generators, dual power flow WECS with the electrical variable transmission (EVT) machine, and direct grid-connected WECS. Finally, the future trends of the technologies are discussed

Conversion of Low Quality Waste Heat to Electric Power with Small-Scale Organic Rankine Cycle (ORC) Engine/Generator Technology

Science.gov (United States)

2016-08-01

efficiency by reducing energy consumption associated with electrical generation and reduces greenhouse gas emissions by increasing electrical generating...integrated system fuel economy test conditions This computation requires prediction of fuel consumption over baseline and integrated system load...EW-201251) Conversion of Low Quality Waste Heat to Electric Power with Small-Scale Organic Rankine Cycle (ORC) Engine/Generator Technology

GaN transistors for efficient power conversion

CERN Document Server

Lidow, Alex; de Rooij, Michael; Reusch, David

2014-01-01

The first edition of GaN Transistors for Efficient Power Conversion was self-published by EPC in 2012, and is currently the only other book to discuss GaN transistor technology and specific applications for the technology. More than 1,200 copies of the first edition have been sold through Amazon or distributed to selected university professors, students and potential customers, and a simplified Chinese translation is also available. The second edition has expanded emphasis on applications for GaN transistors and design considerations. This textbook provides technical and application-focused i

Fission Surface Power Technology Development Update

Science.gov (United States)

Palac, Donald T.; Mason, Lee S.; Houts, Michael G.; Harlow, Scott

2011-01-01

Power is a critical consideration in planning exploration of the surfaces of the Moon, Mars, and places beyond. Nuclear power is an important option, especially for locations in the solar system where sunlight is limited or environmental conditions are challenging (e.g., extreme cold, dust storms). NASA and the Department of Energy are maintaining the option for fission surface power for the Moon and Mars by developing and demonstrating technology for a fission surface power system. The Fission Surface Power Systems project has focused on subscale component and subsystem demonstrations to address the feasibility of a low-risk, low-cost approach to space nuclear power for surface missions. Laboratory demonstrations of the liquid metal pump, reactor control drum drive, power conversion, heat rejection, and power management and distribution technologies have validated that the fundamental characteristics and performance of these components and subsystems are consistent with a Fission Surface Power preliminary reference concept. In addition, subscale versions of a non-nuclear reactor simulator, using electric resistance heating in place of the reactor fuel, have been built and operated with liquid metal sodium-potassium and helium/xenon gas heat transfer loops, demonstrating the viability of establishing system-level performance and characteristics of fission surface power technologies without requiring a nuclear reactor. While some component and subsystem testing will continue through 2011 and beyond, the results to date provide sufficient confidence to proceed with system level technology readiness demonstration. To demonstrate the system level readiness of fission surface power in an operationally relevant environment (the primary goal of the Fission Surface Power Systems project), a full scale, 1/4 power Technology Demonstration Unit (TDU) is under development. The TDU will consist of a non-nuclear reactor simulator, a sodium-potassium heat transfer loop, a power

SSTAC/ARTS review of the draft Integrated Technology Plan (ITP). Volume 3: Space power and thermal management

International Nuclear Information System (INIS)

1991-06-01

Viewgraphs of briefings from the SSTAC/ARTS review of the draft integrated technology plan on thermal power and thermal management are presented. Topics covered include: space energy conversion research and technology; space photovoltaic energy conversion; chemical energy conversion and storage; thermal energy conversion; power management; thermal management; space nuclear power; high capacity power; surface power and thermal management; space platforms power and thermal management; and project SELENE

TFTR power conversion and plasma feedback systems

International Nuclear Information System (INIS)

Neumeyer, C.

1985-01-01

Major components of the Tokamak Fusion Test Reactor (TFTR) power conversion system include 39 thyristor rectifier power supplies, 12 energy storage capacitor banks, and 6 ohmic heating interrupters. These components are connected in various series/parallel configurations to provide controlled pulses of current to the Toroidal Field (TF), Ohmic Heating (OH), Equilibrium (vertical) Field (EF), and Horizontal Field (HF) magnet coil systems. Real-time control of the power conversion system is accomplished by a centralized dedicated computer; local control is minimal. Power supply firing angles, capacitor bank charge and discharge commands, interrupter commands, etc., are all determined and issued by the central computer. Plasma Position and Current Control (PPCC) reference signals to power conversion (OH, EF, HF) are determined by separate analog electronics but invoked through the power conversion computer. Real-time fault sensing of plasma parameters, gas injection, neutral beams, etc., are monitored by a separate Discharge Fault System (DFS) but routed through the power conversion computer for pre-programmed shutdown response

Gas turbine power conversion systems for modular HTGRs. Report of a technical committee meeting

International Nuclear Information System (INIS)

2001-08-01

The Technical Committee Meeting (TCM) on Gas Turbine Power Conversion Systems for Modular HTGRs held in Palo Alto, California, USA was convened by the IAEA on the recommendation of its International Working Group on Gas Cooled Reactors (IWGGCR). The meeting was attended by 27 participants from 9 Member States (Argentina, China, France, Japan, Netherlands, Russian Federation, South Africa, United Kingdom and the United States of America). In addition to presentations on relevant technology development activities in participating Member States, 16 technical papers were presented covering the areas of: Power conversion system design; Power conversion system analysis; and Power conversion system component design. A panel discussion was held on technology issues associated with gas turbine modular HTGR power conversion systems and the potential for international collaboration to address these issues. The purpose of this Technical Committee Meeting was to foster the international exchange of information and perspectives on gas turbine power conversion systems and components for modular HTGRs. The overall objectives were to provide: a current overview of designs under consideration; information on the commercial availability or development status of key components; exchange of information on the issues involved and potential solutions; identification of further development needs for both initial deployment and longer term performance enhancement, and the potential for addressing needs through international collaboration. The following conclusions and recommendations were identified as a result of the discussions at the meeting. International review and collaboration is of interest for China and Japan in the planning and conduct of their test programs: both the HTTR and HTR-10 reactor projects are exploring scale model testing of a gas turbine, with the HTTR project considering a 7 MWt gas heated loop, and HTR-10 a direct or indirect cycle connected to the reactor; the HTR

Mirror hybrid reactor blanket and power conversion system conceptual design

International Nuclear Information System (INIS)

Schultz, K.R.; Backus, G.A.; Baxi, C.B.; Dee, J.B.; Estrine, E.A.; Rao, R.; Veca, A.R.

1976-01-01

The conceptual design of the blanket and power conversion system for a gas-cooled mirror hybrid fusion-fission reactor is presented. The designs of the fuel, blanket module and power conversion system are based on existing gas-cooled fission reactor technology that has been developed at General Atomic Company. The uranium silicide fuel is contained in Inconel-clad rods and is cooled by helium gas. The fuel is contained in 16 spherical segment modules which surround the fusion plasma. The hot helium is used to raise steam for a conventional steam cycle turbine generator. The details of the method of support for the massive blanket modules and helium ducts remain to be determined. Nevertheless, the conceptual design appears to be technically feasible with existing gas-cooled technology. A preliminary safety analysis shows that with the development of a satisfactory method of primary coolant circuit containment and support, the hybrid reactor could be licensed under existing Nuclear Regulatory Commission regulations

Brayton Power Conversion Unit Tested: Provides a Path to Future High-Power Electric Propulsion Missions

Science.gov (United States)

Mason, Lee S.

2003-01-01

Closed-Brayton-cycle conversion technology has been identified as an excellent candidate for nuclear electric propulsion (NEP) power conversion systems. Advantages include high efficiency, long life, and high power density for power levels from about 10 kWe to 1 MWe, and beyond. An additional benefit for Brayton is the potential for the alternator to deliver very high voltage as required by the electric thrusters, minimizing the mass and power losses associated with the power management and distribution (PMAD). To accelerate Brayton technology development for NEP, the NASA Glenn Research Center is developing a low-power NEP power systems testbed that utilizes an existing 2- kWe Brayton power conversion unit (PCU) from previous solar dynamic technology efforts. The PCU includes a turboalternator, a recuperator, and a gas cooler connected by gas ducts. The rotating assembly is supported by gas foil bearings and consists of a turbine, a compressor, a thrust rotor, and an alternator on a single shaft. The alternator produces alternating-current power that is rectified to 120-V direct-current power by the PMAD unit. The NEP power systems testbed will be utilized to conduct future investigations of operational control methods, high-voltage PMAD, electric thruster interactions, and advanced heat rejection techniques. The PCU was tested in Glenn s Vacuum Facility 6. The Brayton PCU was modified from its original solar dynamic configuration by the removal of the heat receiver and retrofitting of the electrical resistance gas heater to simulate the thermal input of a steady-state nuclear source. Then, the Brayton PCU was installed in the 3-m test port of Vacuum Facility 6, as shown. A series of tests were performed between June and August of 2002 that resulted in a total PCU operational time of about 24 hr. An initial test sequence on June 17 determined that the reconfigured unit was fully operational. Ensuing tests provided the operational data needed to characterize PCU

Prospects for power plant technology

International Nuclear Information System (INIS)

Schilling, H.D.

1993-01-01

Careful conservation of resources in the enlarged context of the rational utilization of energy, the environment and capital will determine future power plant technology. The mainstays will be the further development of power plant concepts based on fossil (predominantly coal) and nuclear fuels; world-wide, also regenerative and CO 2 -free hydro-electric power will play a role. Rapid conversion of the available potential requires clear, long-term stable and reliable political framework conditions for the release of the necessary entrepreneurial forces. (orig.) [de

Advanced conversion technology review panel report

International Nuclear Information System (INIS)

Frazier, T.A.

1998-01-01

The Department of Energy (DOE), the National Aeronautics and Space Administration (NASA) and the Jet Propulsion Laboratory (JPL) established a DOE lead management team and an Advanced Conversion Technology Review Panel. The panel was tasked with providing the management team with an assessment and ranking of the three advanced conversion technologies. The three advanced conversion technologies were alkali metal thermal to electric converter (AMTEC), Stirling engine converter (SEC), and thermophotovoltaic (TPV). To rate and rank these three technologies, five criteria were developed: (1) Performance, (2) Development and Cost/Production and Cost/Schedule Risk, (3) Spacecraft Interface and Operations, (4) Ability to Scale Conversion, and (5) Safety. Discussed are the relative importance of each of these criteria and the rankings of the three advanced conversion technologies. It was the conclusion of the panel that the technology decision should be based on the risk that DOE and NASA are willing to accept. SEC is the most mature technology and would provide the lowest risk option. However, if more risk is acceptable, AMTEC not only provides benefits in the spacecraft interface but is also predicted to outperform the SEC. It was proposed that if AMTEC were selected, funding should be provided at a reasonable level to support back-up technology to be developed in a parallel fashion until AMTEC has proven its capability. The panel report and conclusion were provided to DOE in February 1997

Evaluation of maximum power point tracking in hydrokinetic energy conversion systems

Directory of Open Access Journals (Sweden)

Jahangir Khan

2015-11-01

Full Text Available Maximum power point tracking is a mature control issue for wind, solar and other systems. On the other hand, being a relatively new technology, detailed discussion on power tracking of hydrokinetic energy conversion systems are generally not available. Prior to developing sophisticated control schemes for use in hydrokinetic systems, existing know-how in wind or solar technologies can be explored. In this study, a comparative evaluation of three generic classes of maximum power point scheme is carried out. These schemes are (a tip speed ratio control, (b power signal feedback control, and (c hill climbing search control. In addition, a novel concept for maximum power point tracking: namely, extremum seeking control is introduced. Detailed and validated system models are used in a simulation environment. Potential advantages and drawbacks of each of these schemes are summarised.

Solid state frequency conversion technology for remote sensing

International Nuclear Information System (INIS)

Velsko, S.P.; Webb, M.S.; Cook, W.M.; Neuman, W.A.

1994-07-01

Long range remote sensing from airborne or other highly mobile platforms will require high average power tunable radiation from very compact and efficient laser systems. The solid state laser pumped optical parametric oscillator (OPO) has emerged as a leading candidate for such high average power, widely tunable sources. In contrast to laboratory systems, efficiency and simplicity can be the decisive issues which determine the practicality of a particular airborne remote sensing application. The recent advent of diode laser pumped solid state lasers has produced high average power OPO pump sources which are themselves both compact and efficient. However, parametric oscillator technology which can efficiently convert the average powers provided by these pump sources remains to be demonstrated. In addition to the average power requirement, many airborne long range sensing tasks will require a high degree of frequency multiplexing to disentangle data from multiple chemical species. A key advantage in system simplicity can be obtained, for example, if a single OPO can produce easily controlled multispectral output. In this paper the authors address several topics pertaining to the conversion efficiency, power handling, and multispectral capabilities of OPOs which they are currently investigating. In Section 2, single pulse conversion efficiency issues are addressed, while average power effects are treated in Section 3. Section 4 is concerned with multispectral performance of a single OPO. The last section contains a short summary and some concluding remarks

Review on the conversion of thermoacoustic power into electricity.

Science.gov (United States)

Timmer, Michael A G; de Blok, Kees; van der Meer, Theo H

2018-02-01

Thermoacoustic engines convert heat energy into high amplitude acoustic waves and subsequently into electric power. This article provides a review of the four main methods to convert the (thermo)acoustic power into electricity. First, loudspeakers and linear alternators are discussed in a section on electromagnetic devices. This is followed by sections on piezoelectric transducers, magnetohydrodynamic generators, and bidirectional turbines. Each segment provides a literature review of the given technology for the field of thermoacoustics, focusing on possible configurations, operating characteristics, output performance, and analytical and numerical methods to study the devices. This information is used as an input to discuss the performance and feasibility of each method, and to identify challenges that should be overcome for a more successful implementation in thermoacoustic engines. The work is concluded by a comparison of the four technologies, concentrating on the possible areas of application, the conversion efficiency, maximum electrical power output and more generally the suggested focus for future work in the field.

Inertial confinement fusion reaction chamber and power conversion system study

International Nuclear Information System (INIS)

Maya, I.; Schultz, K.R.; Battaglia, J.M.

1984-09-01

GA Technologies has developed a conceptual ICF reactor system based on the Cascade rotating-bed reaction chamber concept. Unique features of the system design include the use of low activation SiC in a reaction chamber constructed of box-shaped tiles held together in compression by prestressing tendons to the vacuum chamber. Circulating Li 2 O granules serve as the tritium breeding and energy transport material, cascading down the sides of the reaction chamber to the power conversion system. The total tritium inventory of the system is 6 kg; tritium recovery is accomplished directly from the granules via the vacuum system. A system for centrifugal throw transport of the hot Li 2 O granules from the reaction chamber to the power conversion system has been developed. A number of issues were evaluated during the course of this study. These include the response of first-layer granules to the intense microexplosion surface heat flux, cost effective fabrication of Li 2 O granules, tritium inventory and recovery issues, the thermodynamics of solids-flow options, vacuum versus helium-medium heat transfer, and the tradeoffs of capital cost versus efficiency for alternate heat exchange and power conversion system option. The resultant design options appear to be economically competitive, safe, and environmentally attractive

Nuclear power technology requirements for NASA exploration missions

International Nuclear Information System (INIS)

Bloomfield, H.S.

1990-01-01

This paper discusses how future exploration of the Moon and Mars will mandate developments in many areas of technology. In particular, major advances will be required in planet surface power systems and space transportation systems. Critical nuclear technology challenges that can enable strategic self-sufficiency, acceptable operational costs and cost-effective space transportation goals for NASA exploration missions have been identified. Critical technologies for surface power systems include stationary and mobile nuclear reactor and radio-isotope heat sources coupled to static and dynamic power conversion devices. These technologies can provide dramatic reductions in mass leading to operational and transportation cost savings. Critical technologies for space transportation systems include nuclear thermal rocket and nuclear electric propulsion options which present compelling concepts for significantly reducing mass, cost or travel time required for Earth-Mars transport

Free-piston Stirling technology for space power

Science.gov (United States)

Slaby, Jack G.

1989-01-01

An overview is presented of the NASA Lewis Research Center free-piston Stirling engine activities directed toward space power. This work is being carried out under NASA's new Civil Space Technology Initiative (CSTI). The overall goal of CSTI's High Capacity Power element is to develop the technology base needed to meet the long duration, high capacity power requirements for future NASA space missions. The Stirling cycle offers an attractive power conversion concept for space power needs. Discussed here is the completion of the Space Power Demonstrator Engine (SPDE) testing-culminating in the generation of 25 kW of engine power from a dynamically-balanced opposed-piston Stirling engine at a temperature ratio of 2.0. Engine efficiency was approximately 22 percent. The SPDE recently has been divided into two separate single-cylinder engines, called Space Power Research Engine (SPRE), that now serve as test beds for the evaluation of key technology disciplines. These disciplines include hydrodynamic gas bearings, high-efficiency linear alternators, space qualified heat pipe heat exchangers, oscillating flow code validation, and engine loss understanding.

Direct Drive Generator for Renewable Power Conversion from Water Currents

International Nuclear Information System (INIS)

Segergren, Erik

2005-01-01

In this thesis permanent magnet direct drive generator for power conversion from water currents is studied. Water currents as a power source involves a number of constrains as well as possibilities, especially when direct drive and permanent magnets are considered. The high power fluxes and low current velocities of a water current, in combination with its natural variations, will affect the way the generator is operated and, flowingly, the appearance of the generator. The work in this thesis can, thus, be categorized into two general topics, generator technology and optimization. Under the first topic, fundamental generator technology is used to increase the efficiency of a water current generator. Under the latter topic, water current generators are optimized to a specific environment. The conclusion drawn from this work is that it is possible to design very low speed direct drive generators with good electromagnetic properties and wide efficiency peak

Status of Wind Power Technologies

DEFF Research Database (Denmark)

Zhao, Haoran; Wu, Qiuwei

2018-01-01

With the development of wind turbine technology, wind power will become more controllable and grid‐friendly. It is desirable to make wind farms operate as conventional power plants. Wind turbine generators (WTGs) were mainly used in rural and remote areas for wind power generation. WTG‐based wind...... energy conversion systems (WECS) can be divided into the four main types (type 1‐4). Due to the inherent variability and uncertainty of the wind, the integration of wind power into the grid has brought challenges in several different areas, including power quality, system reliability, stability......, and planning. The impact of each is largely dependent on the level of wind power penetration in the grid. In many countries, relatively high levels of wind power penetration have been achieved. This chapter shows the estimated wind power penetration in leading wind markets....

An overview of power electronic converter technology for renewable energy systems

DEFF Research Database (Denmark)

Chen, Zhe

2013-01-01

This chapter presents power electronic technology which is an enabling tool for modern wind and marine energy conversion systems. In this chapter, the main power electronic devices are described. Various power electronic converter topologies are represented, and commonly used modulation schemes...

A Review of Tribomaterial Technology for Space Nuclear Power Systems

Science.gov (United States)

Stanford, Malcolm K.

2007-01-01

The National Aeronautics and Space Administration (NASA) has recently proposed a nuclear closed-cycle electric power conversion system for generation of 100-kW of electrical power for space exploration missions. A critical issue is the tribological performance of sliding components within the power conversion unit that will be exposed to neutron radiation. This paper presents a review of the main considerations that have been made in the selection of solid lubricants for similar applications in the past as well as a recommendations for continuing development of the technology.

Free-piston Stirling technology for space power

International Nuclear Information System (INIS)

Slaby, J.G.

1994-01-01

An overview is presented of the NASA Lewis Research Center free-piston Stirling engine activities directed toward space power. This work is being carried out under NASA's new Civil Space Technology Initiative (CSTI). The overall goal of CSTI's High Capacity Power element is to develop the technology base needed to meet the long duration, high capacity power requirements for future NASA space missions. The Stirling cycle offers an attractive power conversion concept for space power needs. Discussed in this paper is the completion of the Space Power Demonstrator Engine (SPDE) testing - culminating in the generation of 25 kW of engine power from a dynamically-balanced opposed-piston Stirling engine at a temperature ratio of 2.0. Engine efficiency was approximately 22 percent. The SPDE recently has been divided into two separate single-cylinder engines, called Space Power Research Engines (SPRE), that now serve as test beds for the evaluation of key technology disciplines. These disciplines include hydrodynamic gas bearings, high-efficiency linear alternators, space qualified heat pipe heat exchangers, oscillating flow code validation, and engine loss understanding. The success of the SPDE at 650 K has resulted in a more ambitious Stirling endeavor - the design, fabrication, test and evaluation of a designed-for-space 25 kW per cylinder Stirling Space Engine (SSE). The SSE will operate at a hot metal temperature of 1050 K using superalloy materials. This design is a low temperature confirmation of the 1300 K design. It is the 1300 K free-piston Stirling power conversion system that is the ultimate goal; to be used in conjunction with the SP-100 reactor. The approach to this goal is in three temperature steps. However, this paper concentrates on the first two phases of this program - the 650 K SPDE and the 1050 K SSE

Coal conversion and the HTR - basic elements of novel power supply concepts

International Nuclear Information System (INIS)

Buerger, F.H.

1985-01-01

A meeting under this title was held in Dortmund on 16 to 19 September, 1985, jointly by the VGB Technische Vereinigung der Grosskraftwerksbetreiber e.V., Essen, and the Vereinigte Elektrizitaetswerke Westfalen AG (VEW), Dortmund. The meeting was held in two sections: 'Gersteinwerk power plant - the combination unit K and the KUV coal conversion system' and '7th International conference on HTR technology'. Three technologies were discussed that will have a significant role on the future energy market, i.e., the HTR reactor line (first applied in the Hamm-Uentrop THTR reactor), the new generation of coal-fired power plants with combined gas/steam turbines, and the coal gasification technology. All three systems will make more efficient and less-polluting use of domestic coal by using HTR process heat, by converting coal to widen its range of applications, and by providing more efficient combination units for power plants. (orig./UA) [de

Power conversion and balance of plant considerations for the STARFIRE commercial tokamak reactor

International Nuclear Information System (INIS)

Barry, K.; Graumann, D.

1981-01-01

The power conversion and balance of plant facilities for this tenth-of-a-kind tokamak fusion power plant are a combination of both features common to any large power plant, and elements peculiar to the fusion technology. For example, the steam generators, turbine-generator and main condenser components of the power conversion system and the natural draft cooling towers that are used for heat rejection at sites not close to a large body of water are generic to power plants. The tritium reprocessing facilities that minimize the tritium inventory in the plant, the Electrical and RF Power Supply Building that contains the coil and rf power supplies, the cryogenic facilities that provide liquid helium coolant for the superconducting coils, and the Hot Cell in which fully remote repair and maintenance functions are performed are unique to a fusion power plant. One of the major features of the STARFIRE design is steady state operation that maximizes overall facility reliability and eliminates both thermal storage requirements and potential power fluctuations on the grid. The reference reactor power is 4000 MWt with a gross electric power generation of 1440 MW. For STARFIRE, water is the preferred coolant and is utilized in both the first wall/blanket and limiter cooling circuits. Dual parallel primary coolant loops cool the twenty-four first-wall/blanket sectors. The power deposited in the limiter, approximately 5% of the total thermal power, is removed by the separate limiter/feedwater loop and is used for feedwater heating in the steam power conversion system

EDITORIAL: The 6th International Workshop on Micro and Nanotechnologies for Power Generation and Energy Conversion Applications (PowerMEMS 2006)

Science.gov (United States)

Fréchette, Luc G.

2007-09-01

Energy is a sector of paramount importance over the coming decades if we are to ensure sustainable development that respects our environment. The research and development of novel approaches to convert available energy into usable forms using micro and nanotechnologies can contribute towards this goal and meet the growing need for power in small scale portable applications. The dominant power sources for handheld and other portable electronics are currently primary and rechargeable batteries. Their limited energy density and adverse effects on the environment upon disposal suggest that alternative approaches need to be explored. This special issue will showcase some of the leading work in this area, initially presented at PowerMEMS 2006, the 6th International Workshop on Micro and Nanotechnologies for Power Generation and Energy Conversion Applications. Power MEMS are defined as microsystems for electrical power generation and other energy conversion applications, including propulsion and cooling. The range of power MEMS technologies includes micro thermodynamic machines, such as microturbines, miniature internal combustion engines and micro-coolers; solid-state direct energy conversion, such as thermoelectric and photovoltaic microstructures; micro electrochemical devices, such as micro fuel cells and nanostructure batteries; vibration energy harvesting devices, such as piezoelectric, magnetic or electrostatic micro generators, as well as micro thrusters and rocket engines for propulsion. These can either be driven by scavenging thermal, mechanical or solar energy from the environment, or from a stored energy source, such as chemical fuel or radioactive material. The unique scope leads to unique challenges in the development of power MEMS, ranging from the integration of novel materials to the efficient small scale implementation of energy conversion principles. In this special issue, Mitcheson et al provide a comparative assessment of three inertial vibration

The alkali metal thermoelectric converter /AMTEC/ - A new direct energy conversion technology for aerospace power

Science.gov (United States)

Bankston, C. P.; Cole, T.; Jones, R.; Ewell, R.

1982-01-01

A thermally regenerative electrochemical device for the direct conversion of heat to electrical energy, the alkali metal thermoelectric converter (AMTEC), is characterized by potential efficiencies on the order of 15-40% and possesses no moving parts, making it a candidate for space power system applications. Device conversion efficiency is projected on the basis of experimental voltage vs current curves exhibiting power densities of 0.7 W/sq cm and measured electrode efficiencies of up to 40%. Preliminary radiative heat transfer measurements presented may be used in an investigation of methods for the reduction of AMTEC parasitic radiation losses. AMTEC assumes heat input and rejection temperatures of 900-1300 K and 400-800 K, respectively. The working fluid is liquid sodium, and the porous electrode employed is of molybdenum.

Energy conversion and utilization technologies

International Nuclear Information System (INIS)

1988-01-01

The DOE Energy Conversion and Utilization Technologies (ECUT) Program continues its efforts to expand the generic knowledge base in emerging technological areas that support energy conservation initiatives by both the DOE end-use sector programs and US private industry. ECUT addresses specific problems associated with the efficiency limits and capabilities to use alternative fuels in energy conversion and end-use. Research is aimed at understanding and improving techniques, processes, and materials that push the thermodynamic efficiency of energy conversion and usage beyond the state of the art. Research programs cover the following areas: combustion, thermal sciences, materials, catalysis and biocatalysis, and tribology. Six sections describe the status of direct contact heat exchange; the ECUT biocatalysis project; a computerized tribology information system; ceramic surface modification; simulation of internal combustion engine processes; and materials-by-design. These six sections have been indexed separately for inclusion on the database. (CK)

Solar thermal energy conversion to electrical power

International Nuclear Information System (INIS)

Trinh, Anh-Khoi; González, Ivan; Fournier, Luc; Pelletier, Rémi; Sandoval V, Juan C.; Lesage, Frédéric J.

2014-01-01

The conversion of solar energy to electricity currently relies primarily on the photovoltaic effect in which photon bombardment of photovoltaic cells drives an electromotive force within the material. Alternatively, recent studies have investigated the potential of converting solar radiation to electricity by way of the Seebeck effect in which charge carrier mobility is generated by an asymmetric thermal differential. The present study builds upon these latest advancements in the state-of-the-art of thermoelectric system management by combining solar evacuated tube technology with commercially available Bismuth Telluride semiconductor modules. The target heat source is solar radiation and the target heat sink is thermal convection into the ambient air relying on wind aided forced convection. These sources of energy are reproduced in a laboratory controlled environment in order to maintain a thermal dipole across a thermoelectric module. The apparatus is then tested in a natural environment. The novelty of the present work lies in a net thermoelectric power gain for ambient environment applications and an experimental validation of theoretical electrical characteristics relative to a varying electrical load. - Highlights: • Solar radiation maintains a thermal tension which drives an electromotive force. • Voltage, current and electric power are reported and discussed. • Theoretical optimal thermoelectric conversion predictions are presented. • Theory is validated with experimentally measured data

EDITORIAL: The Fourth International Workshop on Micro and Nanotechnology for Power Generation and Energy Conversion Applications (PowerMEMS 2004)

Science.gov (United States)

Tanaka, Shuji; Toriyama, Toshiyuki

2005-09-01

This special issue of the Journal of Micromechanics and Microengineering features papers selected from the Fourth International Workshop on Micro and Nanotechnology for Power Generation and Energy Conversion Applications (PowerMEMS 2004). The workshop was held in Kyoto, Japan, on 28-30 November 2004, by The Ritsumeikan Research Institute of Micro System Technology in cooperation with The Global Emerging Technology Institute, The Institute of Electrical Engineers of Japan, The Sensors and Micromachines Society, The Micromachine Center and The Kyoto Nanotech Cluster. Power MEMS is one of the newest categories of MEMS, which encompasses microdevices and microsystems for power generation, energy conversion and propulsion. The first concept of power MEMS was proposed in the late 1990s by Epstein's group at the Massachusetts Institute of Technology, where they continue to study MEMS-based gas turbine generators. Since then, the research and development of power MEMS have been promoted by the need for compact power sources with high energy and power density. Since its inception, power MEMS has expanded to include not only various MEMS-based power generators but also small energy machines and microdevices for macro power generators. At the last workshop, various devices and systems, such as portable fuel cells and their peripherals, micro and small turbo machinery, energy harvesting microdevices, and microthrusters, were presented. Their power levels vary from ten nanowatts to hundreds of watts, spanning ten orders of magnitude. The first PowerMEMS workshop was held in 2000 in Sendai, Japan, and consisted of only seven invited presentations. The workshop has grown since then, and in 2004 there were 5 invited, 20 oral and 29 poster presentations. From the 54 papers in the proceedings, 12 papers have been selected for this special issue. I would like to express my appreciation to the members of the Organizing Committee and Technical Program Committee. This special issue was

Proceedings of the 25th intersociety energy conversion engineering conference

International Nuclear Information System (INIS)

Nelson, P.A.; Schertz, W.W.; Till, R.H.

1990-01-01

This book contains the proceedings of the 25th intersociety energy conversion engineering conference. Volume 1 is organized under the following headings: space power systems requirements and issues, space power systems; space power systems 2; space nuclear power reactors space nuclear reactor technology I; space nuclear reactor technology II; reactor technology; isotopic fueled power systems I, isotopic fueled power systems II, space power automation; space power automation II, space power automation III; space power automation IV; space power automation V; power systems hardware and design selection, power components, pulse power, power management and distribution, power management and distribution II, power management and distribution III; space energy conversion: solar dynamic, space energy conversion: static and dynamic, space solar array technology, advanced space solar cells

Highly efficient power system based on direct fission fragment energy conversion utilizing magnetic collimation

International Nuclear Information System (INIS)

Tsvetkov, Pavel V.; Hart, Ron R.; Parish, Theodore A.

2003-01-01

The present study was focused on developing a technologically feasible power system that is based on direct fission fragment energy conversion utilizing magnetic collimation. The new concept is an attempt to combine several advantageous design solutions, which have been proposed for application in both fission and fusion reactors, into one innovative system that can offer exceptional energy conversion efficiency. The analysis takes into consideration a wide range of operational aspects including fission fragment escape from the fuel, collimation, collection, criticality, long-term performance, energy conversion efficiency, heat removal, and safety characteristics. Specific characteristics of the individual system components and the entire system are evaluated. Consistent analysis and evaluation of the technological feasibility of the concept were achieved using state-of-the-art computer codes that allowed realistic and consistent modeling. The calculated energy conversion efficiencies for the presented designs without a thermodynamic cycle and with the heavy water cycle are 52% and 62%, respectively. The analysis indicates that efficiencies up to 90% are potentially achievable. (author)

Research on spacecraft electrical power conversion

Science.gov (United States)

Wilson, T. G.

1983-01-01

The history of spacecraft electrical power conversion in literature, research and practice is reviewed. It is noted that the design techniques, analyses and understanding which were developed make today's contribution to power computers and communication installations. New applications which require more power, improved dynamic response, greater reliability, and lower cost are outlined. The switching mode approach in electronic power conditioning is discussed. Technical aspects of the research are summarized.

Technology assessment of wind energy conversion systems

Energy Technology Data Exchange (ETDEWEB)

Meier, B. W.; Merson, T. J.

1980-09-01

Environmental data for wind energy conversion systems (WECSs) have been generated in support of the Technology Assessment of Solar Energy (TASE) program. Two candidates have been chosen to characterize the WECS that might be deployed if this technology makes a significant contribution to the national energy requirements. One WECS is a large machine of 1.5-MW-rated capacity that can be used by utilities. The other WECS is a small machine that is characteristic of units that might be used to meet residential or small business energy requirements. Energy storage systems are discussed for each machine to address the intermittent nature of wind power. Many types of WECSs are being studied and a brief review of the technology is included to give background for choosing horizontal axis designs for this study. Cost estimates have been made for both large and small systems as required for input to the Strategic Environmental Assessment Simulation (SEAS) computer program. Material requirements, based on current generation WECSs, are discussed and a general discussion of environmental impacts associated with WECS deployment is presented.

Output power maximization of low-power wind energy conversion systems revisited: Possible control solutions

Energy Technology Data Exchange (ETDEWEB)

Vlad, Ciprian; Munteanu, Iulian; Bratcu, Antoneta Iuliana; Ceanga, Emil [' ' Dunarea de Jos' ' University of Galati, 47, Domneasca, 800008-Galati (Romania)

2010-02-15

This paper discusses the problem of output power maximization for low-power wind energy conversion systems operated in partial load. These systems are generally based on multi-polar permanent-magnet synchronous generators, who exhibit significant efficiency variations over the operating range. Unlike the high-power systems, whose mechanical-to-electrical conversion efficiency is high and practically does not modify the global optimum, the low-power systems global conversion efficiency is affected by the generator behavior and the electrical power optimization is no longer equivalent with the mechanical power optimization. The system efficiency has been analyzed by using both the maxima locus of the mechanical power versus the rotational speed characteristics, and the maxima locus of the electrical power delivered versus the rotational speed characteristics. The experimental investigation has been carried out by using a torque-controlled generator taken from a real-world wind turbine coupled to a physically simulated wind turbine rotor. The experimental results indeed show that the steady-state performance of the conversion system is strongly determined by the generator behavior. Some control solutions aiming at maximizing the energy efficiency are envisaged and thoroughly compared through experimental results. (author)

Output power maximization of low-power wind energy conversion systems revisited: Possible control solutions

International Nuclear Information System (INIS)

Vlad, Ciprian; Munteanu, Iulian; Bratcu, Antoneta Iuliana; Ceanga, Emil

2010-01-01

This paper discusses the problem of output power maximization for low-power wind energy conversion systems operated in partial load. These systems are generally based on multi-polar permanent-magnet synchronous generators, who exhibit significant efficiency variations over the operating range. Unlike the high-power systems, whose mechanical-to-electrical conversion efficiency is high and practically does not modify the global optimum, the low-power systems global conversion efficiency is affected by the generator behavior and the electrical power optimization is no longer equivalent with the mechanical power optimization. The system efficiency has been analyzed by using both the maxima locus of the mechanical power versus the rotational speed characteristics, and the maxima locus of the electrical power delivered versus the rotational speed characteristics. The experimental investigation has been carried out by using a torque-controlled generator taken from a real-world wind turbine coupled to a physically simulated wind turbine rotor. The experimental results indeed show that the steady-state performance of the conversion system is strongly determined by the generator behavior. Some control solutions aiming at maximizing the energy efficiency are envisaged and thoroughly compared through experimental results.

Surface reflectance and conversion efficiency dependence of technologies for mitigating global warming

Energy Technology Data Exchange (ETDEWEB)

Edmonds, Ian [Solartran Pty Ltd., 12 Lentara St, Kenmore, Brisbane 4069 (Australia); Smith, Geoff [Physics and Advanced Materials, University of Technology, Sydney, PO Box 123, Broadway, New South Wales 2007 (Australia)

2011-05-15

A means of assessing the relative impact of different renewable energy technologies on global warming has been developed. All power plants emit thermal energy to the atmosphere. Fossil fuel power plants also emit CO{sub 2} which accumulates in the atmosphere and provides an indirect increase in global warming via the greenhouse effect. A fossil fuel power plant may operate for some time before the global warming due to its CO{sub 2} emission exceeds the warming due to its direct heat emission. When a renewable energy power plant is deployed instead of a fossil fuel power plant there may be a significant time delay before the direct global warming effect is less than the combined direct and indirect global warming effect from an equivalent output coal fired plant - the ''business as usual'' case. Simple expressions are derived to calculate global temperature change as a function of ground reflectance and conversion efficiency for various types of fossil fuelled and renewable energy power plants. These expressions are used to assess the global warming mitigation potential of some proposed Australian renewable energy projects. The application of the expressions is extended to evaluate the deployment in Australia of current and new geo-engineering and carbon sequestration solutions to mitigate global warming. Principal findings are that warming mitigation depends strongly on the solar to electric conversion efficiency of renewable technologies, geo-engineering projects may offer more economic mitigation than renewable energy projects and the mitigation potential of reforestation projects depends strongly on the location of the projects. (author)

Advances in wind energy conversion technology

CERN Document Server

Sathyajith, Mathew

2011-01-01

The technology of generating energy from wind has significantly changed during the past five years. The book brings together all the latest aspects of wind energy conversion technology - from wind resource analysis to grid integration of generated electricity.

Electrical Power Conversion of River and Tidal Power Generator

Energy Technology Data Exchange (ETDEWEB)

Muljadi, Eduard; Gevorgian, Vahan; Wright, Alan; Donegan, James; Marnagh, Cian; McEntee, Jarlath

2016-11-21

As renewable generation has become less expensive during recent decades, and it becomes more accepted by the global population, the focus on renewable generation has expanded to include new types with promising future applications, such as river and tidal generation. Although the utilization of power electronics and electric machines in industry is phenomenal, the emphasis on system design is different for various sectors of industry. In precision control, robotics, and weaponry, the design emphasis is on accuracy and reliability with less concern for the cost of the final product. In energy generation, the cost of energy is the prime concern; thus, capital expenditures (CAPEX) and operations and maintenance expenditures (OPEX) are the major design objectives. This paper describes the electrical power conversion aspects of river and tidal generation. Although modern power converter control is available to control the generation side, the design was chosen on the bases of minimizing the CAPEX and OPEX; thus, the architecture is simple and modular for ease of replacement and maintenance. The power conversion is simplified by considering a simple diode bridge and a DC-DC power converter to take advantage of abundant and low-cost photovoltaic inverters that have well-proven grid integration characteristics (i.e., the capability to produce energy with good power quality and control real power and voltage on the grid side).

Advanced power conversion based on the Aerocapacitor{trademark}. Final report

Energy Technology Data Exchange (ETDEWEB)

Roark, D.

1997-03-05

This report summarizes work performed under contract No. DE-FC07-94ID13283, {open_quotes}Advanced Power Conversion Based on the Aerocapacitors{trademark}.{close_quotes} Under this contract high power density, high energy density, organic electrolyte Aerocapacitors{trademark} were developed and characterized for power conversion applications. Pilot facilities for manufacturing prototype AA-size Aerocapacitors{trademark} were put in place. The low ESR and good frequency response of these devices show that they are ideal components for high discharge rate and low to moderate frequency (< 10 kHz) applications such as power conversion.

Novel Space-based Solar Power Technologies and Architectures for Earth and Beyond

Science.gov (United States)

Howell, Joe T.; Fikes, John C.; O'Neill, Mark J.

2005-01-01

Research, development and studies of novel space-based solar power systems, technologies and architectures for Earth and beyond are needed to reduce the cost of clean electrical power for terrestrial use and to provide a stepping stone for providing an abundance of power in space, i.e., manufacturing facilities, tourist facilities, delivery of power between objects in space, and between space and surface sites. The architectures, technologies and systems needed for space to Earth applications may also be used for in-space applications. Advances in key technologies, i.e., power generation, power management and distribution, power beaming and conversion of beamed power are needed to achieve the objectives of both terrestrial and extraterrestrial applications. Power beaming or wireless power transmission (WPT) can involve lasers or microwaves along with the associated power interfaces. Microwave and laser transmission techniques have been studied with several promising approaches to safe and efficient WPT identified. These investigations have included microwave phased array transmitters, as well as laser transmission and associated optics. There is a need to produce "proof-of-concept" validation of critical WPT technologies for both the near-term, as well as far-term applications. Investments may be harvested in near-term beam safe demonstrations of commercial WPT applications. Receiving sites (users) include ground-based stations for terrestrial electrical power, orbital sites to provide power for satellites and other platforms, future space elevator systems, space vehicle propulsion, and space to surface sites. This paper briefly discusses achieving a promising approach to the solar power generation and beamed power conversion. The approach is based on a unique high-power solar concentrator array called Stretched Lens Array (SLA) for both solar power generation and beamed power conversion. Since both versions (solar and laser) of SLA use many identical components

Potential for efficient frequency conversion at high average power using solid state nonlinear optical materials

International Nuclear Information System (INIS)

Eimerl, D.

1985-01-01

High-average-power frequency conversion using solid state nonlinear materials is discussed. Recent laboratory experience and new developments in design concepts show that current technology, a few tens of watts, may be extended by several orders of magnitude. For example, using KD*P, efficient doubling (>70%) of Nd:YAG at average powers approaching 100 KW is possible; and for doubling to the blue or ultraviolet regions, the average power may approach 1 MW. Configurations using segmented apertures permit essentially unlimited scaling of average power. High average power is achieved by configuring the nonlinear material as a set of thin plates with a large ratio of surface area to volume and by cooling the exposed surfaces with a flowing gas. The design and material fabrication of such a harmonic generator are well within current technology

Facing technological challenges of Solar Updraft Power Plants

Science.gov (United States)

Lupi, F.; Borri, C.; Harte, R.; Krätzig, W. B.; Niemann, H.-J.

2015-01-01

The Solar Updraft Power Plant technology addresses a very challenging idea of combining two kinds of renewable energy: wind and solar. The working principle is simple: a Solar Updraft Power Plant (SUPP) consists of a collector area to heat the air due to the wide-banded ultra-violet solar radiation, the high-rise solar tower to updraft the heated air to the atmosphere, and in between the power conversion unit, where a system of coupled turbines and generators transforms the stream of heated air into electric power. A good efficiency of the power plant can only be reached with extra-large dimensions of the tower and/or the collector area. The paper presents an up-to-date review of the SUPP technology, focusing on the multi-physics modeling of the power plant, on the structural behavior of the tower and, last but not least, on the modeling of the stochastic wind loading process.

Modeling on a PWR power conversion system with system program

International Nuclear Information System (INIS)

Gao Rui; Yang Yanhua; Lin Meng

2007-01-01

Based on the power conversion system of nuclear and conventional islands of Daya Bay Power Station, this paper models the thermal-hydraulic systems of primary and secondary loops for PWR by using the PWR best-estimate program-RELAP5. To simulate the full-scope power conversion system, not only the traditional basic system models of nuclear island, but also the major system models of conventional island are all considered and modeled. A comparison between the calculated results and the actual data of reactor demonstrates a fine match for Daya Bay Nuclear Power Station, and manifests the feasibility in simulating full-scope power conversion system of PWR by RELAP5 at the same time. (authors)

SP-100/Brayton power system concepts

International Nuclear Information System (INIS)

Owen, D.F.

1989-01-01

Use of closed Brayton cycle (CBC) power conversion technology has been investigated for use with SP-100 reactors for space power systems. The CBC power conversion technology is being developed by Rockwell International under the Dynamic Isotype Power System (DIPS) and Space Station Freedom solar dynamic power system programs to provide highly efficient power conversion with radioisotype and solar collector heat sources. Characteristics including mass, radiator area, thermal power, and operating temperatures for systems utilizing SP-100 reactor and CBC power conversion technology were determined for systems in the 10-to 100-kWe power range. Possible SP-100 reactor/CBC power system configurations are presented. Advantages of CBC power conversion technology with regard to reactor thermal power, operating temperature, and development status are discussed

The principles of electronic and electromechanic power conversion a systems approach

CERN Document Server

Ferreira, Braham

2013-01-01

Teaching the principles of power electronics and electromechanical power conversion through a unique top down systems approach, The Principles of Electromechanical Power Conversion takes the role and system context of power conversion functions as the starting point. Following this approach, the text defines the building blocks of the system and describes the theory of how they exchange power with each other. The authors introduce a modern, simple approach to machines, which makes the principles of field oriented control and space vector theory approachable to undergraduate students as well as

ASTRID power conversion system: Assessment on steam and gas options

International Nuclear Information System (INIS)

Laffont, Guy; Cachon, Lionel; Jourdain, Vincent; Fauque, Jean Marie

2013-01-01

Conclusion: ◆ Two power conversion systems have been investigated for the ASTRID prototype. ◆ Steam PCS: • Most mature system based on a well-developed turbomachinery technology. • High plant efficiency. • Studies on steam generators designs and leak detection systems in progress with the aim of reducing the risk of large SWRs and of limiting its consequences. • Design and licensing safety assessment of a SFR must deal with the Sodium Water Air reaction (SWAR). ◆ Gas PCS: • Strong advantage as it inherently eliminates the SWR and SWAR risks. • Very innovative option: major breakthroughs but feasibility and viability not yet demonstrated. • Remaining technological challenges but no showstopper indentified. • General architecture: investigations in progress to improve performances, operability and maintainability

Direct digital conversion detector technology

Science.gov (United States)

Mandl, William J.; Fedors, Richard

1995-06-01

Future imaging sensors for the aerospace and commercial video markets will depend on low cost, high speed analog-to-digital (A/D) conversion to efficiently process optical detector signals. Current A/D methods place a heavy burden on system resources, increase noise, and limit the throughput. This paper describes a unique method for incorporating A/D conversion right on the focal plane array. This concept is based on Sigma-Delta sampling, and makes optimum use of the active detector real estate. Combined with modern digital signal processors, such devices will significantly increase data rates off the focal plane. Early conversion to digital format will also decrease the signal susceptibility to noise, lowering the communications bit error rate. Computer modeling of this concept is described, along with results from several simulation runs. A potential application for direct digital conversion is also reviewed. Future uses for this technology could range from scientific instruments to remote sensors, telecommunications gear, medical diagnostic tools, and consumer products.

Limitations of power conversion systems under transient loads and impact on the pulsed tokamak power reactor

International Nuclear Information System (INIS)

Sager, G.T.; Wong, C.P.C.; Kapich, D.D.; McDonald, C.F.; Schleicher, R.W.

1993-11-01

The impact of cyclic loading of the power conversion system of a helium-cooled, pulsed tokamak power plant is assessed. Design limits of key components of heat transport systems employing Rankie and Brayton thermodynamic cycles are quantified based on experience in gas-cooled fission reactor design and operation. Cyclic loads due to pulsed tokamak operation are estimated. Expected performance of the steam generator is shown to be incompatible with pulsed tokamak operation without load leveling thermal energy storage. The close cycle gas turbine is evaluated qualitatively based on performance of existing industrial and aeroderivative gas turbines. Advances in key technologies which significantly improve prospects for operation with tokamak fusion plants are reviewed

Combining Energy Conversion and Storage: A Solar Powered Supercapacitor

International Nuclear Information System (INIS)

Narayanan, Remya; Kumar, P. Naresh; Deepa, Melepurath; Srivastava, Avanish Kumar

2015-01-01

Graphical abstract: - Highlights: • A plasmonic TiO_2/CdS/Au fibers photoanode is fabricated for the first time. • The efficiency of the plasmonic cell is greater by 1.35 times than the non-plasmonic one. • A solar powered supercapacitor is developed with plasmonic photoanode and multiwalled carbon nanotubes. • The solar cell current charges the supercapacitor. • A specific capacitance of 150 F g"−"1 is achieved under sunlight without any external bias. - Abstract: A solar powered supercapacitor wherein a plasmonic quantum dot solar cell (QDSC) sources the photocurrent for charging/discharging a conjoined supercapacitor based on multiwalled carbon nanotubes (MWCNTs) is demonstrated. Gold or Au fibers are integrated into a titanium dioxide/cadmium sulfide (TiO_2/CdS) electrode to yield a TiO_2/CdS/Au photoanode. The plasmonic effect of Au fibers is reflected in the higher incident photon to current conversion efficiency (IPCE = 55%) and an improved overall power conversion efficiency (3.45%) produced by the TiO_2/CdS/Au photoanode relative to the non-plasmonic TiO_2/CdS photoanode. A Janus type bi-functional electrode composed of MWCNTs on either face separated by glass is prepared and it is coupled with the TiO_2/CdS/Au electrode and another MWCNT electrode to yield the tandem solar powered supercapacitor. By channelling the photocurrent produced by the QDSC part, under 0.1 sun illumination, the capacitance of the symmetric supercapacitor, without the application of any external bias is 150 F g"−"1 which compares well with reported values of electrically powered MWCNT supercapacitors. Our innovative design for a photo-supercapacitor offers a new paradigm for combining low cost photovoltaics with energy storage to yield a technologically useful device that needs nothing else other than solar energy to run.

Microbial conversion technologies

Energy Technology Data Exchange (ETDEWEB)

Lau, P. [National Research Council of Canada, Ottawa, ON (Canada). Bioconversion and Sustainable Development

2006-07-01

Microbes are a biomass and an valuable resource. This presentation discussed microbial conversion technologies along with background information on microbial cells, their characteristics and microbial diversity. Untapped opportunities for microbial conversion were identified. Metagenomic and genome mining approaches were also discussed, as they can provide access to uncultivated or unculturable microorganisms in communal populations and are an unlimited resource for biocatalysts, novel genes and metabolites. Genome mining was seen as an economical approach. The presentation also emphasized that the development of microbial biorefineries would require significant insights into the relevant microorganisms and that biocatalysts were the ultimate in sustainability. In addition, the presentation discussed the natural fibres initiative for biochemicals and biomaterials. Anticipated outputs were identified and work in progress of a new enzyme-retting cocktail to provide diversity and/or consistency in fibre characteristics for various applications were also presented. It was concluded that it is necessary to leverage understanding of biological processes to produce bioproducts in a clean and sustainable manner. tabs., figs.

Systems modeling for a laser-driven IFE power plant using direct conversion

International Nuclear Information System (INIS)

Meier, W R

2008-01-01

A variety of systems analyses have been conducted for laser driver IFE power plants being developed as part of the High Average Power Laser (HAPL) program. A key factor determining the economics attractiveness of the power plant is the net power conversion efficiency which increases with increasing laser efficiency, target gain and fusion-to-electric power conversion efficiency. A possible approach to increasing the power conversion efficiency is direct conversion of ionized target emissions to electricity. This study examines the potential benefits of increased efficiency when the expanding plasma is inductively coupled to an external circuit allowing some of the ion energy to be directly converted to electricity. For base case direct-drive targets with approximately 24% of the target yield in ions, the benefits are modest, especially for chamber designs that operate at high temperature and thus already have relatively high thermal conversion efficiencies. The reduction in the projected cost of electricity is ∼5-10%

The Nature of Primary Students' Conversation in Technology Education

Science.gov (United States)

Fox-Turnbull, Wendy H.

2016-01-01

Classroom conversations are core to establishing successful learning for students. This research explores the nature of conversation in technology education in the primary classroom and the implications for teaching and learning. Over a year, two units of work in technology were taught in two primary classrooms. Most data was gathered in Round 2…

Electrochemical conversion technologies for optimal design of decentralized multi-energy systems : Modeling framework and technology assessment

NARCIS (Netherlands)

Gabrielli, Paolo; Gazzani, Matteo; Mazzotti, Marco

2018-01-01

The design and operation of integrated multi-energy systems require models that adequately describe the behavior of conversion and storage technologies. Typically, linear conversion performance or fixed data from technology manufacturers are employed, especially for new or advanced technologies.

Power electronics - The key technology for Renewable Energy Systems

DEFF Research Database (Denmark)

Blaabjerg, Frede; Ma, Ke; Yang, Yongheng

2014-01-01

The energy paradigms in many countries (e.g. Germany and Denmark) have experienced a significant change from fossil-based resources to clean renewables (e.g. wind turbines and photovoltaics) in the past few decades. The scenario of highly penetrated renewables is going to be further enhanced...... - Denmark expects to be 100 % fossil-free by 2050. Consequently, it is required that the production, distribution and use of the energy should be as technologically efficient as possible and incentives to save energy at the end-user should also be strengthened. In order to realize the transition smoothly...... and effectively, energy conversion systems, currently based on power electronics technology, will again play an essential role in this energy paradigm shift. Using highly efficient power electronics in power generation, power transmission/distribution and end-user application, together with advanced control...

Overview of free-piston Stirling engine technology for space power application

International Nuclear Information System (INIS)

Slaby, J.G.

1987-01-01

An overview is presented of the National Aeronautics and Space Administration (NASA) Lewis Research Center (LeRC) free-piston Stirling engine activities directed toward space-power application. Free-piston Stirling technology is applicable for both solar and nuclear powered systems. As such, the NASA Lewis Research Center serves as the project office to manage the newly initiated SP-100 Advanced Technology program. This program provides the technology push for providing significant component and subsystem options for increased efficiency, reliability and survivability, and power output growth at reduced specific mass. One of the major elements of the program is the development of advanced power conversion of which the Stirling cycle is a viable candidate. Under this program the status of the 25 kWe opposed-piston Space Power Demonstrator Engine (SPDE) is presented. Included in the SPDE discussion are initial differences between predicted and experimental power outputs and power output influenced by variations in regenerators

Installation and evaluation of a nuclear power plant operator advisor based on artificial intelligence technology

International Nuclear Information System (INIS)

Hajek, B.K.; Miller, D.W.

1989-01-01

This report discusses the following topics on a Nuclear Power Plant operator advisor based on artificial Intelligence Technology; Workstation conversion; Software Conversion; V ampersand V Program Development Development; Simulator Interface Development; Knowledge Base Expansion; Dynamic Testing; Database Conversion; Installation at the Perry Simulator; Evaluation of Operator Interaction; Design of Man-Machine Interface; and Design of Maintenance Facility

Conceptual design of power conversion system for a fusion power reactor with self-cooled LiPb-blanket. EFDA Task TW2-TRP-PPCS12 - Deliverable 4

International Nuclear Information System (INIS)

Vieider, Gottfried

2002-05-01

For FPRs with self-cooled LiPb-blanket and He-cooled first wall and divertor a conceptual design of the power conversion system is developed with emphasis on component feasibility, safety, reliability and thermal efficiency. The resulting power conversion system with a steam turbine is based on proven technology for Na- and He-cooled fission reactors and is assessed to yield an overall net thermal plant efficiency of ∼40 % provided the high primary coolant temperatures of ∼700 deg C can be achieved. The required complexity of the five linked cooling systems can be expected to influence plant cost and reliability

Biological Conversion of Sugars to Hydrocarbons Technology Pathway

Energy Technology Data Exchange (ETDEWEB)

Davis, Ryan; Biddy, Mary J.; Tan, Eric; Tao, Ling; Jones, Susanne B.

2013-03-31

In support of the Bioenergy Technologies Office, the National Renewable Energy Laboratory (NREL) and the Pacific Northwest National Laboratory (PNNL) are undertaking studies of biomass conversion technologies to identify barriers and target research toward reducing conversion costs. Process designs and preliminary economic estimates for each of these pathway cases were developed using rigorous modeling tools (Aspen Plus and Chemcad). These analyses incorporated the best information available at the time of development, including data from recent pilot and bench-scale demonstrations, collaborative industrial and academic partners, and published literature and patents. This technology pathway case investigates the biological conversion of biomass derived sugars to hydrocarbon biofuels, utilizing data from recent literature references and information consistent with recent pilot scale demonstrations at NREL. Technical barriers and key research needs have been identified that should be pursued for the pathway to become competitive with petroleum-derived gasoline, diesel and jet range hydrocarbon blendstocks.

Standard-Cell, Open-Architecture Power Conversion Systems

National Research Council Canada - National Science Library

Boroyevich, D; Wang, F; Lee, F. C; Odendaal, W. G; Edwards, S

2005-01-01

...). This project was purposefully aimed to develop a standardized hierarchical design and analysis methodology for modular power electronics conversion systems using as basis the ISO/OSI seven-layer reference model...

Progress update of NASA's free-piston Stirling space power converter technology project

Science.gov (United States)

Dudenhoefer, James E.; Winter, Jerry M.; Alger, Donald

1992-01-01

A progress update is presented of the NASA LeRC Free-Piston Stirling Space Power Converter Technology Project. This work is being conducted under NASA's Civil Space Technology Initiative (CSTI). The goal of the CSTI High Capacity Power Element is to develop the technology base needed to meet the long duration, high capacity power requirements for future NASA space initiatives. Efforts are focused upon increasing system power output and system thermal and electric energy conversion efficiency at least five fold over current SP-100 technology, and on achieving systems that are compatible with space nuclear reactors. This paper will discuss progress toward 1050 K Stirling Space Power Converters. Fabrication is nearly completed for the 1050 K Component Test Power Converter (CTPC); results of motoring tests of the cold end (525 K), are presented. The success of these and future designs is dependent upon supporting research and technology efforts including heat pipes, bearings, superalloy joining technologies, high efficiency alternators, life and reliability testing, and predictive methodologies. This paper will compare progress in significant areas of component development from the start of the program with the Space Power Development Engine (SPDE) to the present work on CTPC.

Electrical Power Conversion of a River and Tidal Power Generator: Preprint

Energy Technology Data Exchange (ETDEWEB)

Muljadi, Eduard; Gevorgian, Vahan; Wright, Alan; Donegan, James; Marnagh, Cian; McEntee, Jarlath

2016-09-01

As renewable generation has become less expensive during recent decades, and it becomes more accepted by the global population, the focus on renewable generation has expanded to include new types with promising future applications, such as river and tidal generation. Although the utilization of power electronics and electric machines in industry is phenomenal, the emphasis on system design is different for various sectors of industry. In precision control, robotics, and weaponry, the design emphasis is on accuracy and reliability with less concern for the cost of the final product. In energy generation, the cost of energy is the prime concern; thus, capital expenditures (CAPEX) and operations and maintenance expenditures (OPEX) are the major design objectives. This paper describes the electrical power conversion aspects of river and tidal generation. Although modern power converter control is available to control the generation side, the design was chosen on the bases of minimizing the CAPEX and OPEX; thus, the architecture is simple and modular for ease of replacement and maintenance. The power conversion is simplified by considering a simple diode bridge and a DC-DC power converter to take advantage of abundant and low-cost photovoltaic inverters that have well-proven grid integration characteristics (i.e., the capability to produce energy with good power quality and control real power and voltage on the grid side).

Thermodynamic limit for coherence-limited solar power conversion

Science.gov (United States)

Mashaal, Heylal; Gordon, Jeffrey M.

2014-09-01

The spatial coherence of solar beam radiation is a key constraint in solar rectenna conversion. Here, we present a derivation of the thermodynamic limit for coherence-limited solar power conversion - an expansion of Landsberg's elegant basic bound, originally limited to incoherent converters at maximum flux concentration. First, we generalize Landsberg's work to arbitrary concentration and angular confinement. Then we derive how the values are further lowered for coherence-limited converters. The results do not depend on a particular conversion strategy. As such, they pertain to systems that span geometric to physical optics, as well as classical to quantum physics. Our findings indicate promising potential for solar rectenna conversion.

Exergetic comparison of two different cooling technologies for the power cycle of a thermal power plant

International Nuclear Information System (INIS)

Blanco-Marigorta, Ana M.; Victoria Sanchez-Henriquez, M.; Pena-Quintana, Juan A.

2011-01-01

Exergetic analysis is without any doubt a powerful tool for developing, evaluating and improving an energy conversion system. In the present paper, two different cooling technologies for the power cycle of a 50 MWe solar thermal power plant are compared from the exergetic viewpoint. The Rankine cycle design is a conventional, single reheat design with five closed and one open extraction feedwater heaters. The software package GateCycle is used for the thermodynamic simulation of the Rankine cycle model. The first design configuration uses a cooling tower while the second configuration uses an air cooled condenser. With this exergy analysis we identify the location, magnitude and the sources or thermodynamic inefficiencies in this thermal system. This information is very useful for improving the overall efficiency of the power system and for comparing the performance of both technologies.

PREFACE: The 15th International Conference on Micro and Nanotechnology for Power Generation and Energy Conversion Applications (PowerMEMS 2015)

Science.gov (United States)

Livermore, C.; Velásquez-García, L. F.

2015-12-01

Greetings, and welcome to Boston, MA and PowerMEMS 2015 - the 15th International Conference on Micro and Nanotechnology for Power Generation and Energy Conversion Applications! The objective of PowerMEMS 2015 is to catalyze innovation in micro- and nano-scale technologies for the energy domain. The scope of the meeting ranges from basic principles, to materials and fabrication, to devices and systems, to applications. The many applications of Power MEMS range from the harvesting, storage, conversion and conditioning of energy, to integrated systems that manage these processes, to actuation, pumping, and propulsion. Our Conference aims to stimulate the exchange of insights and information, as well as the development of new ideas, in the Power MEMS field. Our goal is to allow the attendees to interact and network within our multidisciplinary community that includes professionals from many branches of science and engineering, as well as energy, policy, and entrepreneurial specialists interested in the commercialization of Power MEMS technologies. Since the first PowerMEMS in Sendai, Japan in 2000, the Conference has grown in size, reputation, impact, and technical breadth. This continuing growth is evident in this year's technical program, which includes an increasing number of papers on nanomaterials, additive manufacturing for energy systems, actuators, energy storage, harvesting strategies and integrated energy harvesting systems, for example. This year's technical program is highlighted by six plenary talks from prominent experts on piezoelectrics, robotic insects, thermoelectrics, photovoltaics, nanocomposite cathodes, and thermal energy conversion systems. The contributed program received a large number of abstract submissions this year, 169 in total. After careful review by the 34-member Technical Program Committee, a total of 135 papers were selected for presentation. The 60 contributed oral presentations are arranged in two parallel sessions. The 75 posters

Photovoltaic technologies for commercial power generation

International Nuclear Information System (INIS)

Carlson, D.E.

1990-01-01

Photovoltaic power generation is an attractive source of energy since it involves the direct conversion of sunlight into electricity with no moving parts and no pollution. Following the demonstration of the first solar cell 35 years ago at Bell Laboratories, a steady stream of scientific and commercial progress has led to a rapid increase in applications in recent years. The first commercial application of solar cells occurred more than 20 years ago when they were used to supply power for space satellites, and even today photovoltaic arrays are used to supply electricity for most satellites and space probes. This paper reviews the status of the various photovoltaic technologies as well as present applications. The prospects for both distributed and central station grid-connected systems are discussed. The paper concludes with a discussion of the institutional and political factors that will affect the introduction of grid-connected photovoltaic power systems

Preliminary Study of Printed Circuit Heat Exchanger (PCHE) for various power conversion systems for SMART

Energy Technology Data Exchange (ETDEWEB)

Kwon, Jinsu; Baik, Seungjoon; Lee, Jeong Ik [KAIST, Daejeon (Korea, Republic of)

2016-10-15

The steam-Rankine cycle was the most widely used power conversion system for a nuclear power plant. The size of the heat exchanger is important for the modulation. Such a challenge was conducted by Kang et al. They change the steam generator type for the SMART from helical type heat exchanger to Printed Circuit Heat Exchanger (PCHE). Recently, there has been a growing interest in the supercritical carbon dioxide (S-CO{sub 2}) Brayton cycle as the most promising power conversion system. The reason is high efficiency with simple layout and compact power plant due to small turbomachinery and compact heat exchanger technology. That is why the SCO{sub 2} Brayton cycle can enhance the existing advantages of Small Modular Reactor (SMR) like SMART, such as reduction in size, capital cost, and construction period. Thermal hydraulic and geometric parameters of a PCHE for the S-CO{sub 2} power cycle coupled to SMART. The results show that the water - CO{sub 2} printed circuit heat exchanger size is smaller than printed circuit steam generator for the superheated steam Rankine cycle. This results show the potential benefit of using the S-CO-2 Brayton power cycle to a water-cooled small modular reactor.

Deep conversion of black oils with Eni Slurry technology

Energy Technology Data Exchange (ETDEWEB)

Panariti, Nicoletta; Rispoli, Giacomo

2010-09-15

Eni Slurry Technology represents a significant technological innovation in residue conversion and unconventional oils upgrading. EST allows the almost total conversion of heavy feedstocks into useful products, mainly transportation fuels, with a great major impact on the economic and environmental valorization of hydrocarbon resources. The peculiar characteristics of EST in terms of yields, products quality, absence of undesired by-products and feedstock flexibility constitute its superior economic and environmental attractiveness. The first full scale industrial plant based on this new technology will be realized in Eni's Sannazzaro refinery (23,000 bpd). Oil in is scheduled by 4th quarter 2012.

Plasma technology - a novel solution for CO2 conversion?

Science.gov (United States)

Snoeckx, Ramses; Bogaerts, Annemie

2017-10-02

CO 2 conversion into value-added chemicals and fuels is considered as one of the great challenges of the 21st century. Due to the limitations of the traditional thermal approaches, several novel technologies are being developed. One promising approach in this field, which has received little attention to date, is plasma technology. Its advantages include mild operating conditions, easy upscaling, and gas activation by energetic electrons instead of heat. This allows thermodynamically difficult reactions, such as CO 2 splitting and the dry reformation of methane, to occur with reasonable energy cost. In this review, after exploring the traditional thermal approaches, we have provided a brief overview of the fierce competition between various novel approaches in a quest to find the most effective and efficient CO 2 conversion technology. This is needed to critically assess whether plasma technology can be successful in an already crowded arena. The following questions need to be answered in this regard: are there key advantages to using plasma technology over other novel approaches, and if so, what is the flip side to the use of this technology? Can plasma technology be successful on its own, or can synergies be achieved by combining it with other technologies? To answer these specific questions and to evaluate the potentials and limitations of plasma technology in general, this review presents the current state-of-the-art and a critical assessment of plasma-based CO 2 conversion, as well as the future challenges for its practical implementation.

Experimental Results From a 2kW Brayton Power Conversion Unit

Science.gov (United States)

Hervol, David; Mason, Lee; Birchenough, Arthur

2003-01-01

This paper presents experimental test results from operation of a 2 kWe Brayton power conversion unit. The Brayton converter was developed for a solar dynamic power system flight experiment planned for the Mir Space Station in 1997. The flight experiment was cancelled, but the converter was tested at Glenn Research Center as part of the Solar Dynamic Ground Test Demonstration system which included a solar concentrator, heat receiver, and space radiator. In preparation for the current testing, the heat receiver was removed and replaced with an electrical resistance heater, simulating the thermal input of a steady-state nuclear source. The converter was operated over a full range of thermal input power levels and rotor speeds to generate an overall performance map. The converter unit will serve as the centerpiece of a Nuclear Electric Propulsion Testbed at Glenn. Future potential uses for the Testbed include high voltage electrical controller development, integrated electric thruster testing and advanced radiator demonstration testing to help guide high power Brayton technology development for Nuclear Electric Propulsion (NEP).

A closed Brayton power conversion unit concept for nuclear electric propulsion for deep space missions

International Nuclear Information System (INIS)

Joyner, Claude Russell II; Fowler, Bruce; Matthews, John

2003-01-01

In space, whether in a stable satellite orbit around a planetary body or traveling as a deep space exploration craft, power is just as important as the propulsion. The need for power is especially important for in-space vehicles that use Electric Propulsion. Using nuclear power with electric propulsion has the potential to provide increased payload fractions and reduced mission times to the outer planets. One of the critical engineering and design aspects of nuclear electric propulsion at required mission optimized power levels is the mechanism that is used to convert the thermal energy of the reactor to electrical power. The use of closed Brayton cycles has been studied over the past 30 or years and shown to be the optimum approach for power requirements that range from ten to hundreds of kilowatts of power. It also has been found to be scalable to higher power levels. The Closed Brayton Cycle (CBC) engine power conversion unit (PCU) is the most flexible for a wide range of power conversion needs and uses state-of-the-art, demonstrated engineering approaches. It also is in use with many commercial power plants today. The long life requirements and need for uninterrupted operation for nuclear electric propulsion demands high reliability from a CBC engine. A CBC engine design for use with a Nuclear Electric Propulsion (NEP) system has been defined based on Pratt and Whitney's data from designing long-life turbo-machines such as the Space Shuttle turbopumps and military gas turbines and the use of proven integrated control/health management systems (EHMS). An integrated CBC and EHMS design that is focused on using low-risk and proven technologies will over come many of the life-related design issues. This paper will discuss the use of a CBC engine as the power conversion unit coupled to a gas-cooled nuclear reactor and the design trends relative to its use for powering electric thrusters in the 25 kWe to 100kWe power level

Relation of the second law of thermodynamics to the power conversion of energy fluctuations

International Nuclear Information System (INIS)

Yater, J.C.

1979-01-01

The relation of the second law of thermodynamics to the power conversion of fluctuation energy is analyzed using the master equation of the model for the conversion circuit. The performance equation for independent particles shows that the power-conversion performance is given by the second law both for classical and quantum-effect diodes. The relation of the second law to power-conversion models based on the theoretical and experimental results for diode performance for interacting particles exhibiting many-body, multiparticle, or other anomalous and excess-current effects is examined. The performance equations are derived from the master equation for models for interacting particles to determine the conditions required by the second law for power conversion. These conditions are given in terms of the distribution throughout the power-conversion circuit for all the parameters that determine the particle and multiparticle barrier-crossing probability such as the effective mass and spectral density functions. Circuits for spectroscopic measurements for power-conversion circuits with interacting particles are noted. Using selected experimental values for the diode nonlinearity factors in these circuits, open circuit voltages are computed that are not predicted by the second law of thermodynamics

Green technology for conversion of renewable hydrocarbon based on plasma-catalytic approach

Science.gov (United States)

Fedirchyk, Igor; Nedybaliuk, Oleg; Chernyak, Valeriy; Demchina, Valentina

2016-09-01

The ability to convert renewable biomass into fuels and chemicals is one of the most important steps on our path to green technology and sustainable development. However, the complex composition of biomass poses a major problem for established conversion technologies. The high temperature of thermochemical biomass conversion often leads to the appearance of undesirable byproducts and waste. The catalytic conversion has reduced yield and feedstock range. Plasma-catalytic reforming technology opens a new path for biomass conversion by replacing feedstock-specific catalysts with free radicals generated in the plasma. We studied the plasma-catalytic conversion of several renewable hydrocarbons using the air plasma created by rotating gliding discharge. We found that plasma-catalytic hydrocarbon conversion can be conducted at significantly lower temperatures (500 K) than during the thermochemical ( 1000 K) and catalytic (800 K) conversion. By using gas chromatography, we determined conversion products and found that conversion efficiency of plasma-catalytic conversion reaches over 85%. We used obtained data to determine the energy yield of hydrogen in case of plasma-catalytic reforming of ethanol and compared it with other plasma-based hydrogen-generating systems.

Limits to solar power conversion efficiency with applications to quantum and thermal systems

Science.gov (United States)

Byvik, C. E.; Buoncristiani, A. M.; Smith, B. T.

1983-01-01

An analytical framework is presented that permits examination of the limit to the efficiency of various solar power conversion devices. Thermodynamic limits to solar power efficiency are determined for both quantum and thermal systems, and the results are applied to a variety of devices currently considered for use in space systems. The power conversion efficiency for single-threshold energy quantum systems receiving unconcentrated air mass zero solar radiation is limited to 31 percent. This limit applies to photovoltaic cells directly converting solar radiation, or indirectly, as in the case of a thermophotovoltaic system. Photoelectrochemical cells rely on an additional chemical reaction at the semiconductor-electrolyte interface, which introduces additional second-law demands and a reduction of the solar conversion efficiency. Photochemical systems exhibit even lower possible efficiencies because of their relatively narrow absorption bands. Solar-powered thermal engines in contact with an ambient reservoir at 300 K and operating at maximum power have a peak conversion efficiency of 64 percent, and this occurs for a thermal reservoir at a temperature of 2900 K. The power conversion efficiency of a solar-powered liquid metal magnetohydrodydnamic generator, a solar-powered steam turbine electric generator, and an alkali metal thermoelectric converter is discussed.

A study on the capture of carbon dioxide from a large refinery power station boiler by conversion to oxyfuel operation

Energy Technology Data Exchange (ETDEWEB)

Wilkinson, M.B.; Boden, J.C.; Panesar, R.S.; Allam, R.J. [BP Amoco, Sunbury-on-Thames (United Kingdom)

2001-07-01

A detailed feasibility study has been carried out on the conversion of an existing refinery power station boiler, fired with refinery off-gas, to oxyfuel operation with carbon dioxide capture. The conversion was shown to be technically feasible using proven technologies. Boiler output could be maintained without significant pressure-part modifications and there would be no loss of boiler efficiency. It would be possible to retain a capability to operate in conventional air firing mode for start-up and emergency situations. The concept has been developed to a stage where a demonstration plant could be designed. The major elements of the capital costs of conversion are associated with the air separation unit and the carbon dioxide treatment and compression train and the additional operating costs are associated principally with the power consumption of these units. Further optimisation of the oxyfuel combustion system is possible and it is anticipated that the ongoing developments in air separation technology will help to make significant reductions in these costs in the future. 5 refs., 6 figs.

Photovoltaic technologies for commerical power generation

International Nuclear Information System (INIS)

Carlson, D.E.

1990-01-01

The author reports photovoltaic power generation is an attractive source of energy since it involves the direct conversion of sunlight into electricity with no moving parts and no pollution. Following the demonstration of the first solar cell 35 years ago at Bell Laboratories, a steady stream of scientific and commercial progress has led to a rapid increase in applications in recent years. The first commercial application of solar cells occurred more than 20 years ago when they were used to supply power for space satellites, and even today photovoltaic arrays are used to supply electricity for most satellites and space probes. This paper reviews the status of the various photovoltaic technologies as well as present applications. The prospects for both distributed and central station grid-connected systems are discussed. The paper concludes with a discussion of the institutional and political factors that will affect the introduction of grid-connected photovoltaic power systems

NASA-OAST program in photovoltaic energy conversion

Science.gov (United States)

Mullin, J. P.; Flood, D. J.

1982-01-01

The NASA program in photovoltaic energy conversion includes research and technology development efforts on solar cells, blankets, and arrays. The overall objectives are to increase conversion efficiency, reduce mass, reduce cost, and increase operating life. The potential growth of space power requirements in the future presents a major challenge to the current state of technology in space photovoltaic systems.

Power Electronics – The Key Technology for Renewable Energy System Integration

DEFF Research Database (Denmark)

Blaabjerg, Frede; Yang, Yongheng; Ma, Ke

2015-01-01

The energy paradigms in many countries (e.g. Germany and Denmark) have experienced a significant change from fossil-based resources to clean renewables (e.g. wind turbines and photovoltaics) in the past few decades. The scenario of highly penetrated renewables is going to be further enhanced...... – Denmark expects to be 100 % fossil-free by 2050. Consequently, it is required that the production, distribution and use of the energy should be as technologically efficient as possible and incentives to save energy at the end-user should also be strengthened. In order to realize the transition smoothly...... and effectively, energy conversion systems, currently based on power electronics technology, will again play an essential role in this energy paradigm shift. Using highly efficient power electronics in power generation, power transmission/distribution and end-user application, together with advanced control...

Fission Power System Technology for NASA Exploration Missions

Science.gov (United States)

Mason, Lee; Houts, Michael

2011-01-01

Under the NASA Exploration Technology Development Program, and in partnership with the Department of Energy (DOE), NASA is conducting a project to mature Fission Power System (FPS) technology. A primary project goal is to develop viable system options to support future NASA mission needs for nuclear power. The main FPS project objectives are as follows: 1) Develop FPS concepts that meet expected NASA mission power requirements at reasonable cost with added benefits over other options. 2) Establish a hardware-based technical foundation for FPS design concepts and reduce overall development risk. 3) Reduce the cost uncertainties for FPS and establish greater credibility for flight system cost estimates. 4) Generate the key products to allow NASA decisionmakers to consider FPS as a preferred option for flight development. In order to achieve these goals, the FPS project has two main thrusts: concept definition and risk reduction. Under concept definition, NASA and DOE are performing trade studies, defining requirements, developing analytical tools, and formulating system concepts. A typical FPS consists of the reactor, shield, power conversion, heat rejection, and power management and distribution (PMAD). Studies are performed to identify the desired design parameters for each subsystem that allow the system to meet the requirements with reasonable cost and development risk. Risk reduction provides the means to evaluate technologies in a laboratory test environment. Non-nuclear hardware prototypes are built and tested to verify performance expectations, gain operating experience, and resolve design uncertainties.

Direct-conversion switching-mode audio power amplifier with active capacitive voltage clamp

Energy Technology Data Exchange (ETDEWEB)

Ljusev, P.; Andersen, Michael A.E.

2005-07-01

This paper discusses the advantages and problems when implementing direct energy conversion switching-mode audio power amplifiers. It is shown that the total integration of the power supply and Class D audio power amplifier into one compact direct converter can simplify design, increase efficiency and integration level, reduce product volume and lower its cost. As an example, the principle of operation and the measurements made on a direct-conversion switching-mode audio power amplifier with active capacitive voltage clamp are presented. (au)

Direct-conversion switching-mode audio power amplifier with active capacitive voltage clamp

DEFF Research Database (Denmark)

Ljusev, Petar; Andersen, Michael Andreas E.

2005-01-01

This paper discusses the advantages and problems when implementing direct energy conversion switching-mode audio power amplifiers. It is shown that the total integration of the power supply and Class D audio power amplifier into one compact direct converter can simplify the design, increase...... efficiency, reduce the product volume and lower its cost. As an example, the principle of operation and the measurements made on a direct-conversion switching-mode audio power amplifier with active capacitive voltage clamp are presented....

Self-oscillating modulators for direct energy conversion audio power amplifiers

DEFF Research Database (Denmark)

Ljusev, Petar; Andersen, Michael Andreas E.

2005-01-01

Direct energy conversion audio power amplifier represents total integration of switching-mode power supply and Class D audio power amplifier into one compact stage, achieving high efficiency, high level of integration, low component count and eventually low cost. This paper presents how self-oscillating...

Pulsewidth modulated DC-to-DC power conversion circuits, dynamics, and control designs

CERN Document Server

Choi, Byungcho

2013-01-01

This is the definitive reference for anyone involved in pulsewidth modulated DC-to-DC power conversion Pulsewidth Modulated DC-to-DC Power Conversion: Circuits, Dynamics, and Control Designs provides engineers, researchers, and students in the power electronics field with comprehensive and complete guidance to understanding pulsewidth modulated (PWM) DC-to-DC power converters. Presented in three parts, the book addresses the circuitry and operation of PWM DC-to-DC converters and their dynamic characteristics, along with in-depth discussions of control design of PWM DC-to

Power conversion for a microreactor: a nuclear space application

International Nuclear Information System (INIS)

Guimaraes, Lamartine N.F.; Camillo, Giannino P.; Nascimento, Jamil A.; Borges, Eduardo M.; Placco, Guilherme M.

2009-01-01

Generating nuclear power in space is of fundamental importance if it is desired to realize some aggressive type of exploration. Basically, at Earth orbit (either LEO or GEO) most applications tend to use solar panels, which are just fine, in spite of problems such as vibration, non optimal light incidence angle and non electricity generation due to Earth's shadow. For deep space exploration the nuclear power is been considered as a strong candidate and maybe the only one. The Institute for Advanced Studies is conducting the TERRA project that tracks the developments in the area and, also, intends to develop the key technologies that will allow such a machine to be build with indigenous technology. TERRA stands for TEcnologia de Reatores Rapidos Avancados. This project, at its first stage aims at the specification of the microreactor fuel element with its possible geometrical arrangements. Also for this stage a gas Brayton closed cycle is being considered as a heat conversion to electricity and/or propulsion effect. The basic idea is to adapt an open loop aeronautic gas turbine to operate as a closed loop gas Turbine. This arrangement will use heat pipes as a cold source, or a heat rejection passive system. Up to this point a lot has been done in terms of numerical and graphical development. It is expected that some built up will be happening during this year. An account of this work will be presented at the conference. (author)

Energy technology sources, systems and frontier conversion

CERN Document Server

Ohta, Tokio

1994-01-01

This book provides a concise and technical overview of energy technology: the sources of energy, energy systems and frontier conversion. As well as serving as a basic reference book for professional scientists and students of energy, it is intended for scientists and policy makers in other disciplines (including practising engineers, biologists, physicists, economists and managers in energy related industries) who need an up-to-date and authoritative guide to the field of energy technology.Energy systems and their elemental technologies are introduced and evaluated from the view point

Performance of a Kilowatt-Class Stirling Power Conversion System in a Thermodynamically-Coupled Configuration

Science.gov (United States)

Geng, S. M.; Briggs, M. H.; Hervol, D. S.

A pair of 1kWe free-piston Stirling power convertors has been modified into a thermodynamically coupled configuration, and performance map testing has been completed. This is the same configuration planned for the full-scale 12 kWe power conversion unit (PCU) that will be used in the Fission Power System Technology Demonstration Unit (TDU). The 1-kWe convertors were operated over a range of conditions to evaluate the effects of thermodynamic coupling on convertor performance and to identify any possible control challenges. The thermodynamically coupled convertor showed no measurable difference in performance from the baseline data collected when the engines were separate and no major control issues were encountered during operation. The results of this test are guiding controller development and instrumentation selection for the TDU.

Dimensionless Energy Conversion Characteristics of an Air-Powered Hydraulic Vehicle

OpenAIRE

Dongkai Shen; Qilong Chen; Yixuan Wang

2018-01-01

Due to the advantages of resource conservation and less exhaust emissions, compressed air-powered vehicle has attracted more and more attention. To improve the power and efficiency of air-powered vehicle, an air-powered hydraulic vehicle was proposed. As the main part of the air-powered hydraulic vehicles, HP transformer (short for Hydropneumatic transformer) is used to convert the pneumatic power to higher hydraulic power. In this study, to illustrate the energy conversion characteristics of...

Feasibility study for the partial conversion of a hydropower plant into a pumped-storage power plant: a case study of hydroelectric power plant La Barca (Asturias, Spain

Directory of Open Access Journals (Sweden)

E. Antuña Yudego

2017-01-01

Full Text Available Renewable energy sources have reported an unprecedented increase of global installed renewable power capacity. Against the advantages provided by this renewable power generation technology it should be taken into account an important issue: these intermittent energy sources supply a fluctuating output which is difficult to manage. Pumped-storage hydro power plants reappear in these circumstances as an efficient form of energy storage which allows to use reserves when necessary, enabling power generation output to cover continuously this energy demand. The present paper shows a simplified feasibility study of the partial conversion of hydropower plant La Barca, in Asturias, into a reversible storage through the development of an algorithm to simulate its operation according to electricity market prices. For this purpose, the operation in the deviation management market is considered and the technical modifications required for the conversion are shown. The estimation of costs and incomes present a feasible scenario.

Power generation technologies

CERN Document Server

Breeze, Paul

2014-01-01

The new edition of Power Generation Technologies is a concise and readable guide that provides an introduction to the full spectrum of currently available power generation options, from traditional fossil fuels and the better established alternatives such as wind and solar power, to emerging renewables such as biomass and geothermal energy. Technology solutions such as combined heat and power and distributed generation are also explored. However, this book is more than just an account of the technologies - for each method the author explores the economic and environmental costs and risk factor

Proceedings of the 30. intersociety energy conversion engineering conference. Volume 1

International Nuclear Information System (INIS)

Goswami, D.Y.; Kannberg, L.D.; Somasundaram, S.

1995-01-01

This conference provides a forum to present and discuss the engineering aspects of energy conversion, advanced and unconventional energy systems and devices, energy conversion and utilization, environmental issues and policy implications on research, development, and implementation of technologies. The solution for a sustainable future will lie in a mix of all of the available energy resources (renewable and non-renewable) and diverse energy conversion technologies that will maintain quality of life in a sustainable manner. The 129 papers in Volume 1 deal with aerospace power and are divided into the following topical sections: Aircraft power; Aerospace power systems; Batteries for aerospace power; Computer simulation; Power electronics; Power management; Space solar power; Space power systems; Space energy statics/dynamics; Space power--requirements and issues; Space Station power; Terrestrial applications of space power; Thermal management; Wireless transmission; Space nuclear power; Bimodal propulsion; Electric propulsion; Solar thermal; and Solar bimodal. All papers have been processed separately for inclusion on the data base

The 13th International Conference on Micro and Nanotechnology for Power Generation and Energy Conversion Applications (PowerMEMS 2013)

Science.gov (United States)

Mitcheson, Paul; Beeby, Steve

2013-12-01

It is a pleasure to welcome you to The Royal Society in London and the 13th International Conference on Micro- and Nano-Technology for Power Generation and Energy Conversion Applications, or PowerMEMS 2013. The objective of PowerMEMS 2013 is to catalyse innovation in miniature, micro- and nano-scale technologies for power generation and energy conversion. The conference aims to stimulate the exchange of insights and information, and the development of new ideas in the Power MEMS/NEMS field as well as at the meso-scale. It will allow the attendees to interact and network within our multidisciplinary community that includes professionals from many branches of science and engineering. The technical program is led by four invited speakers covering inductive power transfer, chip scale power sources, thermal energy harvesting and implantable biofuel cells. We received 177 abstracts and following a careful reviewing process by the Technical Program Committee a total of 137 papers were selected for presentation. These have been organised into 16 oral sessions in two parallel streams and two poster sessions that have been augmented by 10 late news papers. The oral and regular poster papers are, for the first time, being published by the Institute of Physics. We have made every effort to make PowerMEMS 2013 the busiest yet and have included for the first time the PowerMEMS School. This two-day school held at Imperial College London covered a wide range of power-MEMS topics including technologies for power generation, power transmission, energy storage, power electronics interfaces and metrology. Registrations for the School exceeded our expectations and it was full by early November. We hope this, and other activities such as the Discussion Panel and the inclusion of late news papers, will make PowerMEMS 2013 a memorable success. We have also reached out to new communities, such as those working in wireless power transfer and RF harvesting to broaden the technology remit of

Magnetic power conversion with machines containing full or porous wheel heat exchangers

Science.gov (United States)

Egolf, Peter W.; Kitanovski, Andrej; Diebold, Marc; Gonin, Cyrill; Vuarnoz, Didier

2009-04-01

A first part of the article contains a thermodynamic theory describing the temperature distribution in a Curie wheel. The occurring nonlinear ordinary differential equation has an analytical solution. If a Curie wheel is stabilized by levitation, it is named Palmy wheel. These wheels show a full structure, and because of this reason, their uptake of heat from a flame (Curie wheel) or by (solar) light absorption (Palmy wheel) only on the periphery of a cylinder is very limited. To improve the method, a modification of the principle by introducing a convective heat transport into a porous wheel is discussed. By this the power conversion rate from a heat flux to mechanical and electric power is very much increased. The second part of the article presents results of a theoretical/numerical study on the efficiencies of magnetic power conversion plants operating with porous wheels. Furthermore, these efficiencies—which are promising—are compared with those of existing power conversion plants, as e.g. geothermal binary cycle power plants.

Magnetic power conversion with machines containing full or porous wheel heat exchangers

International Nuclear Information System (INIS)

Egolf, Peter W.; Kitanovski, Andrej; Diebold, Marc; Gonin, Cyrill; Vuarnoz, Didier

2009-01-01

A first part of the article contains a thermodynamic theory describing the temperature distribution in a Curie wheel. The occurring nonlinear ordinary differential equation has an analytical solution. If a Curie wheel is stabilized by levitation, it is named Palmy wheel. These wheels show a full structure, and because of this reason, their uptake of heat from a flame (Curie wheel) or by (solar) light absorption (Palmy wheel) only on the periphery of a cylinder is very limited. To improve the method, a modification of the principle by introducing a convective heat transport into a porous wheel is discussed. By this the power conversion rate from a heat flux to mechanical and electric power is very much increased. The second part of the article presents results of a theoretical/numerical study on the efficiencies of magnetic power conversion plants operating with porous wheels. Furthermore, these efficiencies-which are promising-are compared with those of existing power conversion plants, as e.g. geothermal binary cycle power plants

Possible improvements of efficiency by the use of new coal conversion technologies

International Nuclear Information System (INIS)

Krieb, K.H.

1976-01-01

Following a comparison of the efficiencies of conventional steam power processes, the gas fuel cell and the combined gas steam turbine processes are introduced as new coal utilization technologies. Coal conversion processes which can be coupled to combined gas-steam turbine processes such as the fluidized-bed firing, the solid bed gasification, the dust part-gasification and the fluidized-bed gasification are more closely mentioned and their coupling efficiencies discussed. The decoupling of third energy, such as low-temperature heat, high-temperature heat and chemical energy are briefly dealt with as third possibility for the improvement of the efficiency. (GG/LH) [de

An approach to the conversion of the power generated by an offshore wind power farm connected into seawave power generator

Energy Technology Data Exchange (ETDEWEB)

Franzitta, Vicenzo; Messineo, Antonio; Trapanese, Marco

2011-07-01

The development of renewable energy systems has been undergoing for the past decades but sea wave's energy resource has been under-utilized. This under-utilization has several reasons: the energy concentration is low in sea waves, extraction of this energy requires leading edge technologies and conversion of the energy into electrical energy is difficult. This study compares two different methods to connect the sea waves' generator to the network and to the offshore wind power farm. The first method consists in a decentralized approach: each generator is connected to the grid through an AC converter. The second method is a partially centralized approach: a rectifier is connected to each generator, all of the generators are then connected together to a common DC bus and power is then converted in AC to be connected to the grid. This study has shown that the partially centralized approach is more reliable and efficient than the decentralized approach.

Compressed Natural Gas Technology for Alternative Fuel Power Plants

Science.gov (United States)

Pujotomo, Isworo

2018-02-01

Gas has great potential to be converted into electrical energy. Indonesia has natural gas reserves up to 50 years in the future, but the optimization of the gas to be converted into electricity is low and unable to compete with coal. Gas is converted into electricity has low electrical efficiency (25%), and the raw materials are more expensive than coal. Steam from a lot of wasted gas turbine, thus the need for utilizing exhaust gas results from gas turbine units. Combined cycle technology (Gas and Steam Power Plant) be a solution to improve the efficiency of electricity. Among other Thermal Units, Steam Power Plant (Combined Cycle Power Plant) has a high electrical efficiency (45%). Weakness of the current Gas and Steam Power Plant peak burden still using fuel oil. Compressed Natural Gas (CNG) Technology may be used to accommodate the gas with little land use. CNG gas stored in the circumstances of great pressure up to 250 bar, in contrast to gas directly converted into electricity in a power plant only 27 bar pressure. Stored in CNG gas used as a fuel to replace load bearing peak. Lawyer System on CNG conversion as well as the power plant is generally only used compressed gas with greater pressure and a bit of land.

Power conversion and quality of the Santa Clara 2 MW direct carbonate fuel cell demonstration plant

Energy Technology Data Exchange (ETDEWEB)

Skok, A.J. [Fuel Cell Engineering Corp., Danbury, CT (United States); Abueg, R.Z. [Basic Measuring Instruments, Santa Clara, CA (United States); Schwartz, P. [Fluor Daniel, Inc., Irvine, CA (United States)] [and others

1996-12-31

The Santa Clara Demonstration Project (SCDP) is the first application of a commercial-scale carbonate fuel cell power plant on a US electric utility system. It is also the largest fuel cell power plant ever operated in the United States. The 2MW plant, located in Santa Clara, California, utilizes carbonate fuel cell technology developed by Energy Research Corporation (ERC) of Danbury, Connecticut. The ultimate goal of a fuel cell power plant is to deliver usable power into an electrical distribution system. The power conversion sub-system does this for the Santa Clara Demonstration Plant. A description of this sub-system and its capabilities follows. The sub-system has demonstrated the capability to deliver real power, reactive power and to absorb reactive power on a utility grid. The sub-system can be operated in the same manner as a conventional rotating generator except with enhanced capabilities for reactive power. Measurements demonstrated the power quality from the plant in various operating modes was high quality utility grade power.

Approaches to building single-stage AC/AC conversion switch-mode audio power amplifiers

DEFF Research Database (Denmark)

Ljusev, Petar; Andersen, Michael Andreas E.

2004-01-01

This paper discusses the possible topologies and promising approaches towards direct single-phase AC-AC conversion of the mains voltage for audio applications. When compared to standard Class-D switching audio power amplifiers with a separate power supply, it is expected that direct conversion...

Maximum Efficiency of Thermoelectric Heat Conversion in High-Temperature Power Devices

Directory of Open Access Journals (Sweden)

V. I. Khvesyuk

2016-01-01

Full Text Available Modern trends in development of aircraft engineering go with development of vehicles of the fifth generation. The features of aircrafts of the fifth generation are motivation to use new high-performance systems of onboard power supply. The operating temperature of the outer walls of engines is of 800–1000 K. This corresponds to radiation heat flux of 10 kW/m2 . The thermal energy including radiation of the engine wall may potentially be converted into electricity. The main objective of this paper is to analyze if it is possible to use a high efficiency thermoelectric conversion of heat into electricity. The paper considers issues such as working processes, choice of materials, and optimization of thermoelectric conversion. It presents the analysis results of operating conditions of thermoelectric generator (TEG used in advanced hightemperature power devices. A high-temperature heat source is a favorable factor for the thermoelectric conversion of heat. It is shown that for existing thermoelectric materials a theoretical conversion efficiency can reach the level of 15–20% at temperatures up to 1500 K and available values of Ioffe parameter being ZT = 2–3 (Z is figure of merit, T is temperature. To ensure temperature regime and high efficiency thermoelectric conversion simultaneously it is necessary to have a certain match between TEG power, temperature of hot and cold surfaces, and heat transfer coefficient of the cooling system. The paper discusses a concept of radiation absorber on the TEG hot surface. The analysis has demonstrated a number of potentialities for highly efficient conversion through using the TEG in high-temperature power devices. This work has been implemented under support of the Ministry of Education and Science of the Russian Federation; project No. 1145 (the programme “Organization of Research Engineering Activities”.

Oscillating thermionic conversion for high-density space power

International Nuclear Information System (INIS)

Jacobson, D.L.; Morris, J.F.

1988-01-01

The compactness, maneuverability, and productive weight utilization of space nuclear reactors benefit from the use of thermionic converters at high temperature. Nuclear-thermionic-conversion power requirements are discussed, and the role of oscillations in thermionic energy conversion (TEC) history is examined. Proposed TEC oscillations are addressed, and the results of recent studies of TEC oscillations are reviewed. The possible use of high-frequency TEC oscillations to amplify low-frequency ones is considered. The accomplishments of various programs studying the use of high-temperature thermionic oscillators are examined. 16 references

Technology and Teaching: A Conversation among Faculty Regarding the Pros and Cons of Technology

Science.gov (United States)

Kemp, Andrew T.; Preston, John; Page, C. Steven; Harper, Rebecca; Dillard, Benita; Flynn, Joseph; Yamaguchi, Misato

2014-01-01

Technology is often touted as the savior of education (Collins & Haverson, 2009). However, is technology the panacea that it is made out to be? This paper is an extended conversation among a group of faculty members at three different universities and their attitudes and beliefs about technology and education. Three professors shared their…

Microhydraulic transducer technology for actuation and power generation

Science.gov (United States)

Hagood, Nesbitt W.; Roberts, David C.; Saggere, Laxminarayana; Breuer, Kenneth S.; Chen, Kuo-Shen; Carretero, Jorge A.; Li, Hanqing; Mlcak, Richard; Pulitzer, Seward W.; Schmidt, Martin A.; Spearing, S. Mark; Su, Yu-Hsuan

2000-06-01

The paper introduces a novel transducer technology, called the solid-state micro-hydraulic transducer, currently under development at MIT. The new technology is enabled through integration of micromachining technology, piezoelectrics, and microhydraulic concepts. These micro-hydraulic transducers are capable of bi-directional electromechanical energy conversion, i.e., they can operate as both an actuator that supplies high mechanical force in response to electrical input and an energy generator that transduces electrical energy from mechanical energy in the environment. These transducers are capable of transducing energy at very high specific power output in the order of 1 kW/kg, and thus, they have the potential to enable many novel applications. The concept, the design, and the potential applications of the transducers are presented. Present efforts towards the development of these transducers, and the challenges involved therein, are also discussed.

Power Conversion Efficiency of AlGaAs/GaAs Schottky Diode for Low-Power On-Chip Rectenna Device Application

International Nuclear Information System (INIS)

Mustafa, Farahiyah; Hashim, Abdul Manaf; Rahman, Shaharin Fadzli Abd; Osman, Mohd Nizam

2011-01-01

A Schottky diode has been designed and fabricated on n-AlGaAs/GaAs high-electron-mobility-transistor (HEMT) structure. Current-voltage (I-V) measurements show good device rectification with a Schottky barrier height of 0.4349 eV for Ni/Au metallization. The differences of Schottky barrier height from theoretical value are due to the fabrication process and smaller contact area. The RF signals up to 1 GHz are well rectified by the fabricated Schottky diodes and stable DC output voltage is obtained. Power conversion efficiency up to 50% is obtained at 1 GHz with series connection between diode and load. The fabricated the n-AlGaAs/GaAs Schottky diode provide conduit for breakthrough designs for ultra-low power on-chip rectenna device technology to be integrated in nanosystems.

16th International Conference on Micro and Nanotechnology for Power Generation and Energy Conversion Applications (PowerMEMS 2016)

International Nuclear Information System (INIS)

2016-01-01

It is our great pleasure to welcome you to PowerMEMS’16 - the 16th International Conference on Micro- and Nano-Technology for Power Generation and Energy Conversion Applications - in Paris at the UIC Espace Congrès, a few meters away from the Eiffel Tower. The objective of the PowerMEMS conference is to catalyse innovation in micro- and nano- scale technologies for the energy domain. The scope of the meeting ranges from basic principles, to materials and fabrication, to devices and systems, to applications. The many applications of Power MEMS concern the harvesting, storage, conversion and conditioning of energy, to integrated systems that manage these processes, to actuation, pumping, and propulsion. Our Conference aims to stimulate the exchange of insights and information, as well as the development of new ideas, in the Power MEMS field. Our goal is to allow the attendees to interact and network within our multidisciplinary community that includes professionals from many branches of science and engineering, as well as energy, policy, and entrepreneurial specialists interested in the commercialization of Power MEMS technologies. This year's technical program is highlighted by four plenary talks from prominent experts on M/NEMS for ultra-low power in electronics, advanced nanomaterial for solar cells and thermal transistor. The contributed program received 159 abstract submissions this year. After careful review by the 33-members of the Technical Program Committee, a total of 123 papers will be presented. The 40 contributed oral presentations are arranged in two parallel sessions. The 83 posters are arranged in a ''two-in-one'' poster session in which the poster session time is divided in two; half the posters will be presented during each half-session, allowing the poster presenters to also browse the posters during the poster session. Posters will remain up during the meeting, so please feel free to peruse them at your leisure. The

Evaluation of a microwave high-power reception-conversion array for wireless power transmission

Science.gov (United States)

Dickinson, R. M.

1975-01-01

Initial performance tests of a 24-sq m area array of rectenna elements are presented. The array is used as the receiving portion of a wireless microwave power transmission engineering verification test system. The transmitting antenna was located at a range of 1.54 km. Output dc voltage and power, input RF power, efficiency, and operating temperatures were obtained for a variety of dc load and RF incident power levels at 2388 MHz. Incident peak RF intensities of up to 170 mW/sq cm yielded up to 30.4 kW of dc output power. The highest derived collection-conversion efficiency of the array was greater than 80 percent.

HVDC transmission power conversion applications in power systems

CERN Document Server

Kim, Chan-Ki; Jang, Gil-Soo; Lim, Seong-Joo; Lee, Seok-Jin

2009-01-01

HVDC is a critical solution to several major problems encountered when trying to maintain systemic links and quality in large-scale renewable energy environments. HDVC can resolve a number of issues, including voltage stability of AC power networks, reducing fault current, and optimal management of electric power, ensuring the technology will play an increasingly important role in the electric power industry. To address the pressing need for an up-to-date and comprehensive treatment of the subject, Kim, Sood, Jang, Lim and Lee have collaborated to produce this key text and reference.  Combin

Assessment of tidal and wave energy conversion technologies in Canada

International Nuclear Information System (INIS)

2009-01-01

This paper presented an attractive option to help meet Canada's future energy needs, notably the vast and energetic Atlantic, Pacific and Arctic coastal waters which make ocean renewable energy, particularly tidal in-stream energy conversion (TISEC) and wave energy conversion (WEC). There is much uncertainty regarding the possible environmental impacts associated with their deployment and operation. In support of commercial development of the industry, a review of scientific knowledge was needed for the development of policy and regulations consistent with Canada's conservation and sustainability priorities. In April 2009, Fisheries and Oceans Canada (DFO) hosted a two-day national science advisory process meeting in order to determine the current state of knowledge on the environmental impacts of tidal and wave energy conversion technologies and their application in the Canadian context based on published reports. Potential mitigation measures were identified and the feasibility of developing a relevant Canadian statement of practice was determined. This report presented an assessment and analysis of wave power, including the impacts on physical processes; impacts on habitat characteristics; impacts on water quality; impacts of noise and vibrations; impacts of electromagnetic fields; impacts of physical encounters; cumulative impacts; and mitigation measures. It was concluded that there is a recognized need to develop and maintain national and regional georeferenced, interoperable, standards-based databases that enable access by governments, developers, academics, non-governmental organizations and the general public. 1 ref., 1 fig.

PREFACE: 14th International Conference on Micro and Nanotechnology for Power Generation and Energy Conversion Applications (PowerMEMS 2014)

Science.gov (United States)

2014-11-01

It is our great pleasure to welcome you to the 14th International Conference on Micro- and Nano-Technology for Power Generation and Energy Conversion Applications, or PowerMEMS 2014, in Awaji Island, Japan. The aim of PowerMEM is to present the latest research results in the field of miniature, micro- and nano-scale technologies for power generation and energy conversion. The conference will also- give us the opportunity to exchange informations and new ideas in the field of Power MEMS/NEMS. The current status of the field of PowerMEMS spans the full spectrum from basic research to practical applications. We will enjoy valuable discussions not only from the viewpoint of academia but from commercial and industrial perspectives. In the conference, three invited speakers lead the technical program. We received 172 abstracts and after a careful reviewing process by the Technical Program Committee a total of 133 papers were selected for presentation. These have been organized into 16 Oral sessions in two parallel streams and two poster sessions including some late-news papers. The oral and regular poster papers are published by the Institute of Physics (IOP). We have also organized a PowerMEMS School in Kobe-Sannomiya contiguous to the main conference. This two-day school will cover various topics of energy harvesting. World leading experts will give invited lectures on their main topics. This is a new experiment to broaden the technology remit of our conference by organizing mini symposiums that aim to gather the latest research on the following topics by the organizers: Microscale Combustion, Wideband Vibration Energy Harvesting, RF Energy Transfer and Industrial Application. We hope this, and other activities will make PowerMEMS2014 a memorable success. One of the important programs in an international conference is the social program, and we prepare the PowerMEMS2014 banquet in the banquet room at the Westin Awaji Island Hotel. This will provide an opportunity to

Environmental effects of energy conversion

International Nuclear Information System (INIS)

Hansmeyer, K.H.; Fortak, H.; Knoepp, H.; Lindackers, K.H.; Schafhausen, F.; Schoedel, J.P.

1984-01-01

The article presents an analysis of energy conversion systems by the ''Council of Environmental Experts'' in order to correct the erroneous assumption that small energy conversion systems will also be small-scale and negligible emitters of pollutants. The additional pollution caused by Neurath power plant is considered to be low, at least in its immediate vicinity, owing to the implementation of the most recent technical developments. The environmental effects of energy conversion processes are discussed, including the waste heat problem and processes for water-cooling of power plants. General aspects of a new concept of energy taxation are discussed which is to reduce energy consumption. The problem of radioactive waste is discussed from spent fuel storage and reprocessing to the decommissioning of older power plants. The author points out that also new fossil-fuel technologies will pollute the environment. (orig.) [de

Impedance-Source Networks for Electric Power Conversion Part I

DEFF Research Database (Denmark)

Siwakoti, Yam P.; Peng, Fang Zheng; Blaabjerg, Frede

2015-01-01

power chain, which may improve the reliability and performance of the power system. The first part of this paper provides a comprehensive review of the various impedance-source-networks-based power converters and discusses the main topologies from an application point of view. This review paper...... is the first of its kind with the aim of providing a “one-stop” information source and a selection guide on impedance-source networks for power conversion for researchers, designers, and application engineers. A comprehensive review of various modeling, control, and modulation techniques for the impedance...

Solid-State Thermionic Nuclear Power for Megawatt Propulsion, Planetary Surface and Commercial Power Project

Data.gov (United States)

National Aeronautics and Space Administration — Thermionic (TI) power conversion is a promising technology first investigated for power conversion in the 1960’s, and of renewed interest due to modern...

Cogeneration Technology Alternatives Study (CTAS). Volume 3: Energy conversion system characteristics

Science.gov (United States)

1980-01-01

Six current and thirty-six advanced energy conversion systems were defined and combined with appropriate balance of plant equipment. Twenty-six industrial processes were selected from among the high energy consuming industries to serve as a frame work for the study. Each conversion system was analyzed as a cogenerator with each industrial plant. Fuel consumption, costs, and environmental intrusion were evaluated and compared to corresponding traditional values. The advanced energy conversion technologies indicated reduced fuel consumption, costs, and emissions. Fuel energy savings of 10 to 25 percent were predicted compared to traditional on site furnaces and utility electricity. With the variety of industrial requirements, each advanced technology had attractive applications. Fuel cells indicated the greatest fuel energy savings and emission reductions. Gas turbines and combined cycles indicated high overall annual savings. Steam turbines and gas turbines produced high estimated returns. In some applications, diesels were most efficient. The advanced technologies used coal derived fuels, or coal with advanced fluid bed combustion or on site gasifications. Data and information for both current and advanced energy conversion technology are presented. Schematic and physical descriptions, performance data, equipment cost estimates, and predicted emissions are included. Technical developments which are needed to achieve commercialization in the 1985-2000 period are identified.

Fiscal 1999 research report. Development of ultralow- loss power device technology (Survey on next-generation practical power semiconductor devices); 1999 nendo choteisonshitsu denryoku soshi gijutsu kaihatsu seika hokokusho. Jisedai power handotai device jitsuyoka chosa

Energy Technology Data Exchange (ETDEWEB)

NONE

2000-03-01

This research proposes the clear developmental policy and target for 'Development project of ultralow-loss power device technology' through the research on power electronics or advanced power semiconductor devices as key technology of conversion loss reduction for various power applications and power supply systems. Main research issues are as follows. A bidirectional current switch using P-MOS FETs is promising as an ace of power system interconnection control equipment. IEGT as MOS gate high-power device will be substituted for GTO gradually. SiC devices will play the leading part of low- loss power devices for inverters of power converters, power systems of electric vehicles, Shinkansen and maglev railways, power systems of information and communication systems, and DC power systems. Size and cost reduction of low-noise soft switching as application technology of power devices are possible by using active circuits. Development of high- efficiency low-noise compact inexpensive inverters is an important issue. Countermeasures against various losses of inverters are also described. (NEDO)

Interregional power transmission: a component in planning for renewable energy technologies

International Nuclear Information System (INIS)

Krueger Nielsen, S.; Soerensen, B.

2000-01-01

We discuss the role played by interregional power transmission on the basis of recent scenario work. In a project dealing with long-term planning for energy efficiency and renewable energy in Europe we modelled a scenario for the present 15 EU countries' energy system in 2050. The basis for the scenario is the concept of 'fair pricing' for energy services, meaning that the price of energy should reflect all externalities, but not otherwise be taxed or subsidized. The project assessed resource availability and expected technology price developments over time for a number of energy-related technologies, both on the supply side, the intermediate conversion chain and on the demand side. Among these, transmission technologies play an important role, both in smoothing out renewable energy supplies within the European Union region, and also allowing substantial import of energy from countries outside the EU having a surplus of renewable energy based power. (orig.)

The new technologies and infrastructure conversion of nuclear testing in Kazakhstan

International Nuclear Information System (INIS)

Kadyrzhanov, K.K.

1999-01-01

It is known, that in August, 1991, in accordance with Decree by the Kazakhstan President, the Semipalatinsk test site (STS) was shut down, and practical works on its conversion were initiated. In 1991 the decision on creation of the Kazakhstan National Nuclear Center (KNNC) on a base of the test site scientific and industrial enterprises and Inst. of Nuclear Physics was taken. In 1993 within frame KNNC three new institutes (Inst. of Atomic Energy, Inst. of Geophysical Research, Inst. of Radiation Safety and Ecology) were created. Owing to this, at the condition of USSR disintegration and liquidation of military division in test site territory, high-qualified personnel was saved, the facilities that represent nuclear danger were left under operation and surveillance, and the full-scale program of STS conversion was developed and put into life. At present guidelines for the major research activities at KNNC on conversion program are as follows: liquidation of consequences of nuclear tests; liquidation of technological structure used before for preparation and implementation of nuclear weapons tests; creation of technology, equipment and locations for receipt and storage of radioactive wastes; working out the concept of nuclear power development in Kazakhstan; investigation of the behaviour of melted reactor core in view of potential heavy accidents at nuclear power plants; development of technique and means for detection of nuclear test in the world, continuous control for nuclear explosions; experimental works on investigation of behaviour of the materials-candidates for role of constructional materials for the thermonuclear reactor ITER; creation of high-technology industries. These and other activities undertaken in this respect allow to attract considerable foreign investments, to create in Kurchatov city hundreds of additional working places.The Government support rendered to KNNC in future will allow to expand substantially this area of activities as well as to

Audio power amplifier techniques with energy efficient power conversion. Vol. 1

Energy Technology Data Exchange (ETDEWEB)

Nielsen, Karsten

1998-04-01

A fundamental study of both analog and digital pulse modulation methods is carried out. A novel class of multi-level pulse modulation methods - Phase Shifted Carrier Pulse Width Modulation (PSCPWM) - is introduced and show to have several advantageous features, primarily caused by the much improved synthesis of the modulating signal. Enhanced digital pulse modulation methods for digital Pulse Modulation Amplifier (PMA) systems are investigated, and a simple methodology for digital PWM modulator synthesis is devised. It is concluded, that the modulator performance is not a limitation in the system, regardless of the domain of modulator implementation. Power conversion in PMA systems is adressed from the perspective of both linearity and efficienty optimization. Based on detailed studies of the distortion mechanisms in the power conversion stage it is concluded, that this is the fundamental limitation on system performance due to several physical limitations. The analysis of general power stage efficiency concludes that dramatic improvements in energy efficiency are possible with PMA systems that are optimized for efficiency. A control system design methodology is devised as a platform for synthesis of robust control systems. Investigations of three fundamental control structures show that even simple control systems offer a remarkable value, although the considered topologies also have their limitations which is verified by practical evaluation in hardware. A novel control method is introduced - Multivariable Enhanced Cascade Control (MECC). MECC provides flexible control over all essential system parameters and is furthermore simple in realization. Practical evaluation of a MECC based PMA shows state-of-the-art performance. The application of non-linear control methods is investigated with the introduction of an enhanced non-linear control/modulator topology. Although the non-linear controller is theoretically interesting, the method proves to suffer from various

Power Electronics – Key Technology for Renewable Energy Systems – Status and Future

DEFF Research Database (Denmark)

Blaabjerg, Frede; Yang, Yongheng; Ma, Ke

2013-01-01

play an essential role. Using highly efficient power electronics in power generation, power transmission/ distribution and end-user application, together with advanced control solutions, can pave the way for renewable energies. In view of this, some of the most emerging renewable energies, e.g. wind......The energy paradigms in many countries (e.g. Germany and Denmark) have experienced a significant change from fossil-based resources to clean renewables in the past few decades. The scenario of highly penetrated renewables is going to be further enhanced. This requires that the production......, distribution and use of the energy should be as technological efficient as possible and incentives to save energy at the end-user should also be streng-thened. In order to realize the transition smoothly and effectively, energy conversion systems, currently based on power electronics technology, will again...

Investigation of modeling and simulation on a PWR power conversion system with RELAP5

International Nuclear Information System (INIS)

Rui Gao; Yang Yanhua; Lin Meng; Yuan Minghao; Xie Zhengrui

2007-01-01

Based on the power conversion system of nuclear and conventional islands of Dayabay nuclear power station, this paper models the thermal-hydraulic systems for PWR by using the best-estimate program, RELAP5. To simulate the full-scope power conversion system, not only the reactor coolant system (RCP) of nuclear island, but also the main steam system (VVP), turbine steam and drain system (GPV), bypass system (GCT), feedwater system (FW), condensate extraction system (CEX), moisture separator reheater system (GSS), turbine-driven feedwater pump (APP), low-pressure and high-pressure feedwater heater systems (ABP and AHP) of conventional island are considered and modeled. A comparison between the simulated results and the actual data of reactor under full-power demonstrates a fine match for Dayabay, and also manifests the feasibility in simulating full-scope power conversion system of PWR with RELAP5. (author)

Self-oscillating modulators for direct energy conversion audio power amplifiers

Energy Technology Data Exchange (ETDEWEB)

Ljusev, P.; Andersen, Michael A.E.

2005-07-01

Direct energy conversion audio power amplifier represents total integration of switching-mode power supply and Class D audio power amplifier into one compact stage, achieving high efficiency, high level of integration, low component count and eventually low cost. This paper presents how self-oscillating modulators can be used with the direct switching-mode audio power amplifier to improve its performance by providing fast hysteretic control with high power supply rejection ratio, open-loop stability and high bandwidth. Its operation is thoroughly analyzed and simulated waveforms of a prototype amplifier are presented. (au)

Energy Conversion Advanced Heat Transport Loop and Power Cycle

Energy Technology Data Exchange (ETDEWEB)

Oh, C. H.

2006-08-01

The Department of Energy and the Idaho National Laboratory are developing a Next Generation Nuclear Plant (NGNP) to serve as a demonstration of state-of-the-art nuclear technology. The purpose of the demonstration is two fold 1) efficient low cost energy generation and 2) hydrogen production. Although a next generation plant could be developed as a single-purpose facility, early designs are expected to be dual-purpose. While hydrogen production and advanced energy cycles are still in its early stages of development, research towards coupling a high temperature reactor, electrical generation and hydrogen production is under way. Many aspects of the NGNP must be researched and developed in order to make recommendations on the final design of the plant. Parameters such as working conditions, cycle components, working fluids, and power conversion unit configurations must be understood. Three configurations of the power conversion unit were demonstrated in this study. A three-shaft design with 3 turbines and 4 compressors, a combined cycle with a Brayton top cycle and a Rankine bottoming cycle, and a reheated cycle with 3 stages of reheat were investigated. An intermediate heat transport loop for transporting process heat to a High Temperature Steam Electrolysis (HTSE) hydrogen production plant was used. Helium, CO2, and an 80% nitrogen, 20% helium mixture (by weight) were studied to determine the best working fluid in terms cycle efficiency and development cost. In each of these configurations the relative component size were estimated for the different working fluids. The relative size of the turbomachinery was measured by comparing the power input/output of the component. For heat exchangers the volume was computed and compared. Parametric studies away from the baseline values of the three-shaft and combined cycles were performed to determine the effect of varying conditions in the cycle. This gives some insight into the sensitivity of these cycles to various

Impedance-Source Networks for Electric Power Conversion Part II

DEFF Research Database (Denmark)

Siwakoti, Yam P.; Peng, Fang Zheng; Blaabjerg, Frede

2015-01-01

Impedance-source networks cover the entire spectrum of electric power conversion applications (dc-dc, dc-ac, ac-dc, ac-ac) controlled and modulated by different modulation strategies to generate the desired dc or ac voltage and current at the output. A comprehensive review of various impedance......-source-network-based power converters has been covered in a previous paper and main topologies were discussed from an application point of view. Now Part II provides a comprehensive review of the most popular control and modulation strategies for impedance-source network-based power converters/inverters. These methods...

Preliminary conceptual design of the blanket and power conversion system for the Mirror Hybrid Reactor

International Nuclear Information System (INIS)

Schultz, K.R.; Culver, D.W.; Rao, S.B.; Rao, S.R.

1978-01-01

A conceptual design of a commercial Mirror Hybrid Reactor, optimized for 239 Pu production, has been completed. This design is the product of a joint effort by Lawrence Livermore Laboratory and General Atomic Company, and follows directly from earlier work on the Mirror Hybrid. This paper describes the blanket and power conversion system of the reactor design. Included are descriptions of the prestressed concrete reactor vessel that supports the magnets and contains the blanket and power conversion system components, the blanket module design, the blanket fuel design, and the power conversion system

An ultra low-power off-line APDM-based switchmode power supply with very high conversion efficiency

DEFF Research Database (Denmark)

Nielsen, Nils

2001-01-01

This article describes the results from the research work on design of a ultra low power off-line power supply with very high conversion efficiency. The input voltage is 230 VAC nominal and output voltage is 5 VDC. By ultra low power levels, an output power level in the area ranging from 50 m......W and up to 1000 mW is meant. The small power supply is intended for use as a standby power supply in mains operated equipment, which requires a small amount of power in standby mode....

Symposium proceedings: environmental aspects of fuel conversion technology, II, December 1975, Hollywood, Florida. [34 papers

Energy Technology Data Exchange (ETDEWEB)

Ayer, F.A. (comp.)

1976-06-01

The report covers EPA's second symposium on the environmental aspects of fuel conversion technology. Its main objective was to review and discuss environmentally related information in the field of fuel conversion technology. Specific topics were environmental problem definition, process technology, control technology, and process measurements. Thirty-four papers were abstracted and indexed separately.

Modeling power electronics and interfacing energy conversion systems

CERN Document Server

Simões, Marcelo Godoy

2017-01-01

Discusses the application of mathematical and engineering tools for modeling, simulation and control oriented for energy systems, power electronics and renewable energy. This book builds on the background knowledge of electrical circuits, control of dc/dc converters and inverters, energy conversion and power electronics. The book shows readers how to apply computational methods for multi-domain simulation of energy systems and power electronics engineering problems. Each chapter has a brief introduction on the theoretical background, a description of the problems to be solved, and objectives to be achieved. Block diagrams, electrical circuits, mathematical analysis or computer code are covered. Each chapter concludes with discussions on what should be learned, suggestions for further studies and even some experimental work.

Proceedings of the 30. intersociety energy conversion engineering conference. Volume 2

International Nuclear Information System (INIS)

Goswami, D.Y.; Kannberg, L.D.; Somasundaram, S.

1995-01-01

This conference provides a forum to present and discuss the engineering aspects of energy conversion, advanced and unconventional energy systems and devices, energy conversion and utilization, environmental issues and policy implications on research, development, and implementation of technologies. The solution for a sustainable future will lie in a mix of all of the available energy resources (renewable and non-renewable) and diverse energy conversion technologies that will maintain quality of life in a sustainable manner. The 100 papers in Volume 2 are divided into the following topical sections: (1) Environmental impact--Impacts and technologies; (2) Energy systems--Electric/hybrid vehicle technology; Transportation system assessments; Simulation and modeling of systems; Cogeneration and other energy systems; Thermal energy storage applications; Fluids and heat transfer topics; Demand-side management in buildings; and Energy management; (3) Policy impacts on energy--Developing countries and Global; (4) Renewable energy sources--Solar and geothermal power; Solar thermal power; Photovoltaics; Biomass power; Solar thermal; and Renewable energy--status and future. All papers have been processed separately for inclusion on the data base

Approaches to building single-stage AC/AC conversion switch-mode audio power amplifiers

Energy Technology Data Exchange (ETDEWEB)

Ljusev, P.; Andersen, Michael A.E.

2005-07-01

This paper discusses the possible topologies and promising approaches towards direct single-phase AC-AC conversion of the mains voltage for audio applications. When compared to standard Class-D switching audio power amplifiers with a separate power supply, it is expected that direct conversion will provide better efficiency and higher level of integration, leading to lower component count, volume and cost, but at the expense of a minor performance deterioration. (au)

Turbostar: an ICF reactor using both direct and thermal power conversion. Revision 1

International Nuclear Information System (INIS)

Pitts, J.H.

1986-01-01

Combining direct and thermal power conversion results in a 52% gross plant efficiency with DT fuel and 68% with advanced DD fuel. We maximize the fraction of fusion-yield energy converted to kinetic energy in a liquid-lithium blanket, and use this energy directly with turbine generators to produce electricity. We use the remainder of the energy to produce electricity in a standard Rankine thermal power conversion cycle

R and D on the power conversion system for gas turbine high temperature reactors

International Nuclear Information System (INIS)

Takizuka, Takakazu; Takada, Shoji; Yan Xing; Kosugiyama, Shinichi; Katanishi, Shoji; Kunitomi, Kazuhiko

2004-01-01

JAERI is conducting R and D on the power conversion system of the GTHTR300 plant, in parallel with plant design work. The design of the power conversion system is based on a regenerative, non-intercooled, closed Brayton cycle with helium gas as the working fluid. A single-shaft, axial-flow turbo-compressor and a directly coupled electric generator run on magnetic bearings. Major R and D issues for the power conversion system are aerodynamic performance of the helium gas compressor, high load capacity magnetic bearings and performance of magnetic bearing supported rotor, and operability and controllability of the closed-cycle gas turbine system. Three test plans were set up to address theses issues, aiming at verifying the design of the GTHTR300 power conversion system and establishing key technologies of a closed-cycle helium gas turbine system. The compressor aerodynamic performance test is aiming at verifying the aerodynamic performance and design method of the helium compressor. A 1/3-scale, four-stage compressor test model and a helium gas loop were designed and fabricated. The model was designed to simulate the repeating stage flow, and at the same time have satisfactorily high machining precision, Reynolds number and measurement accuracy. The helium gas operating pressure is varied to investigate the effects of the Reynolds number on the efficiency and surge margin. Two sets of blades were fabricated to evaluate the effects of the end-wall over-camber angle. Test results will provide the basis for further improvement in the GTHTR300 compressor design. The magnetic bearing development test is aiming at developing the technology of the magnetic bearing supported rotor system. The test rig composed of 1/3-scale turbo-compressor and generator rotor models that are connected together by a flexible coupling. Each rotor models are supported by two radial magnetic bearings with a high load capacity that is about 1/10 of the GTHTR300 design. The rotor models were

Assessment of the technology required to develop photovoltaic power system for large scale national energy applications

Science.gov (United States)

Lutwack, R.

1974-01-01

A technical assessment of a program to develop photovoltaic power system technology for large-scale national energy applications was made by analyzing and judging the alternative candidate photovoltaic systems and development tasks. A program plan was constructed based on achieving the 10 year objective of a program to establish the practicability of large-scale terrestrial power installations using photovoltaic conversion arrays costing less than $0.50/peak W. Guidelines for the tasks of a 5 year program were derived from a set of 5 year objectives deduced from the 10 year objective. This report indicates the need for an early emphasis on the development of the single-crystal Si photovoltaic system for commercial utilization; a production goal of 5 x 10 to the 8th power peak W/year of $0.50 cells was projected for the year 1985. The developments of other photovoltaic conversion systems were assigned to longer range development roles. The status of the technology developments and the applicability of solar arrays in particular power installations, ranging from houses to central power plants, was scheduled to be verified in a series of demonstration projects. The budget recommended for the first 5 year phase of the program is $268.5M.

Technology transfer and design conversion of a dry spent fuel storage system in Ukraine

International Nuclear Information System (INIS)

Peacock, R.C.; Marcelli, D.G.

1998-01-01

A number of unique issues surfaced in the technology transfer and design conversion of a US dry spent fuel storage technology in Ukraine. Unique challenges were encountered in the areas of nuclear design conversion, technical codes and standards, material selection and qualification, fabrication, construction and testing, quality assurance, documentation, and translation and verification processes. Technology transfer and design conversion were undertaken for both concrete and steel components for the project. The overall effort presented significant technical and cultural challenges to both the US and Ukrainian side, but technical exchange and design improvements to achieve a common goal have been reached. (author)

A Flexible Maximum Power Point Tracking Control Strategy Considering Both Conversion Efficiency and Power Fluctuation for Large-inertia Wind Turbines

Directory of Open Access Journals (Sweden)

Hongmin Meng

2017-07-01

Full Text Available In wind turbine control, maximum power point tracking (MPPT control is the main control mode for partial-load regimes. Efficiency potentiation of energy conversion and power smoothing are both two important control objectives in partial-load regime. However, on the one hand, low power fluctuation signifies inefficiency of energy conversion. On the other hand, enhancing efficiency may increase output power fluctuation as well. Thus the two objectives are contradictory and difficult to balance. This paper proposes a flexible MPPT control framework to improve the performance of both conversion efficiency and power smoothing, by adaptively compensating the torque reference value. The compensation was determined by a proposed model predictive control (MPC method with dynamic weights in the cost function, which improved control performance. The computational burden of the MPC solver was reduced by transforming the cost function representation. Theoretical analysis proved the good stability and robustness. Simulation results showed that the proposed method not only kept efficiency at a high level, but also reduced power fluctuations as much as possible. Therefore, the proposed method could improve wind farm profits and power grid reliability.

Switching-mode Audio Power Amplifiers with Direct Energy Conversion

DEFF Research Database (Denmark)

Ljusev, Petar; Andersen, Michael Andreas E.

2005-01-01

has been replaced with a high frequency AC link. When compared to the conventional Class D amplifiers with a separate DC power supply, the proposed single conversion stage amplifier provides simple and compact solution with better efficiency and higher level of integration, leading to reduced...

Selected papers from the 12th International Workshop on Micro and Nanotechnology for Power Generation and Energy Conversion Applications (PowerMEMS 2012) (Atlanta, GA, USA, 2-5 December 2012)

Science.gov (United States)

Allen, Mark G.; Lang, Jeffrey

2013-11-01

Welcome to this special section of the Journal of Micromechanics and Microengineering (JMM). This section, co-edited by myself and by Professor Jeffrey Lang of the Massachusetts Institute of Technology, contains expanded versions of selected papers presented at the Power MEMS meeting held in Atlanta, GA, USA, in December of 2012. Professor Lang and I had the privilege of co-chairing Power MEMS 2012, the 12th International Workshop on Micro and Nanotechnology for Power Generation and Energy Conversion Applications. The scope of the PowerMEMS series of workshops ranges from basic principles, to materials and fabrication, to devices and systems, to applications. The many applications of power MEMS (microelectromehcanical systems) range from MEMS-enabled energy harvesting, storage, conversion and conditioning, to integrated systems that manage these processes. Why is the power MEMS field growing in importance? Smaller-scale power and power supplies (microwatts to tens of watts) are gaining in prominence due to many factors, including the ubiquity of low power portable electronic equipment and the proliferation of wireless sensor nodes that require extraction of energy from their embedding environment in order to function. MEMS manufacturing methods can be utilized to improve the performance of traditional power supply elements, such as allowing batteries to charge faster or shrinking the physical size of passive elements in small-scale power supplies. MEMS technologies can be used to fabricate energy harvesters that extract energy from an embedding environment to power wireless sensor nodes, in-body medical implants and other devices, in which the harvesters are on the small scales that are appropriately matched to the overall size of these microsystems. MEMS can enable the manufacturing of energy storage elements from nontraditional materials by bringing appropriate structure and surface morphology to these materials as well as fabricating the electrical interfaces

A novel MPPT method for enhancing energy conversion efficiency taking power smoothing into account

International Nuclear Information System (INIS)

Liu, Jizhen; Meng, Hongmin; Hu, Yang; Lin, Zhongwei; Wang, Wei

2015-01-01

Highlights: • We discuss the disadvantages of conventional OTC MPPT method. • We study the relationship between enhancing efficiency and power smoothing. • The conversion efficiency is enhanced and the volatility of power is suppressed. • Small signal analysis is used to verify the effectiveness of proposed method. - Abstract: With the increasing capacity of wind energy conversion system (WECS), the rotational inertia of wind turbine is becoming larger. And the efficiency of energy conversion is significantly reduced by the large inertia. This paper proposes a novel maximum power point tracking (MPPT) method to enhance the efficiency of energy conversion for large-scale wind turbine. Since improving the efficiency may increase the fluctuations of output power, power smoothing is considered as the second control objective. A T-S fuzzy inference system (FIS) is adapted to reduce the fluctuations according to the volatility of wind speed and accelerated rotor speed by regulating the compensation gain. To verify the effectiveness, stability and good dynamic performance of the new method, mechanism analyses, small signal analyses, and simulation studies are carried out based on doubly-fed induction generator (DFIG) wind turbine, respectively. Study results show that both the response speed and the efficiency of proposed method are increased. In addition, the extra fluctuations of output power caused by the high efficiency are reduced effectively by the proposed method with FIS

100 kWe lunar/Mars surface power utilizing the SP-100 reactor with dynamic conversion

International Nuclear Information System (INIS)

Harty, R.B.; Mason, L.S.

1992-01-01

This paper reports on an integration study which was performed coupling an SP-100 reactor with either a Brayton of Stirling power conversion subsystem. a power level of 100 kWe was selected for the study. The power system was to be compatible with both the lunar and Mars surface environment and require no site preparation. In addition, the reactor was to have integral shielding and be completely self-contained, including its own auxiliary power for start-up. Initial reliability studies were performed to determine power conversion redundancy and engine module size. For the lunar environment, the reactor and primary coolant loop would be contained in a guard vessel to protect from a loss of primary loop containment. For the Mars environment, all refractory components including the reactor, primary coolant, and power conversion components would be contained in a vacuum vessel for protection against the CO 2 environment

A comparison of energy conversion systems for meeting the power requirements of manned rover for Mars missions

International Nuclear Information System (INIS)

El-Genk, M.S.; Morley, N.; Cataldo, R.; Bloomfield, H.

1990-01-01

Minimizing system mass for interplanetary missions is of utmost importance in order to keep launch cost within reasonable bounds. For a manned Mars rover, powered by a nuclear reactor power system, the choice of the energy conversion system can play a significant role in lowering the overall system mass. Not only is the mass of the conversion unit affected by the choice, but also the masses of the reactor core, waste heat rejection system, and the radiation shield which are strongly influenced by the system conversion efficiency and operating condition. Several types of conversion systems are of interest for a nuclear reactor Mars manned application. These conversion systems include: free piston Stirling engines, He/XE closed Brayton cycle (CBC), CO 2 open Brayton, and SiGe/GaP thermoelectric. Optimization studies are conducted to determine the impact of the conversion system on the overall mass of the nuclear power system as well as the mobility power requirement of the Rover vehicle

Overview of Multi-Kilowatt Free-Piston Stirling Power Conversion Research at GRC

Science.gov (United States)

Geng, Steven M.; Mason, Lee S.; Dyson, Rodger W.; Penswick, L. Barry

2008-01-01

As a step towards development of Stirling power conversion for potential use in Fission Surface Power (FSP) systems, a pair of commercially available 1 kW class free-piston Stirling convertors and a pair of commercially available pressure wave generators (which will be plumbed together to create a high power Stirling linear alternator test rig) have been procured for in-house testing at Glenn Research Center. Delivery of both the Stirling convertors and the linear alternator test rig is expected by October, 2007. The 1 kW class free-piston Stirling convertors will be tested at GRC to map and verify performance. The convertors will later be modified to operate with a NaK liquid metal pumped loop for thermal energy input. The high power linear alternator test rig will be used to map and verify high power Stirling linear alternator performance and to develop power management and distribution (PMAD) methods and techniques. This paper provides an overview of the multi-kilowatt free-piston Stirling power conversion work being performed at GRC.

Overview of Multi-kilowatt Free-Piston Stirling Power Conversion Research at GRC

Science.gov (United States)

Geng, Steven M.; Mason, Lee S.; Dyson, Rodger W.; Penswick, L. Barry

2008-01-01

As a step towards development of Stirling power conversion for potential use in Fission Surface Power (FSP) systems, a pair of commercially available 1 kW class free-piston Stirling convertors and a pair of commercially available pressure wave generators (which will be plumbed together to create a high power Stirling linear alternator test rig) have been procured for in-house testing at Glenn Research Center. Delivery of both the Stirling convertors and the linear alternator test rig is expected by October, 2007. The 1 kW class free-piston Stirling convertors will be tested at GRC to map and verify performance. The convertors will later be modified to operate with a NaK liquid metal pumped loop for thermal energy input. The high power linear alternator test rig will be used to map and verify high power Stirling linear alternator performance and to develop power management and distribution (PMAD) methods and techniques. This paper provides an overview of the multi-kilowatt free-piston Stirling power conversion work being performed at GRC.

Biomass Thermochemical Conversion Program: 1986 annual report

Energy Technology Data Exchange (ETDEWEB)

Schiefelbein, G.F.; Stevens, D.J.; Gerber, M.A.

1987-01-01

Wood and crop residues constitute a vast majority of the biomass feedstocks available for conversion, and thermochemical processes are well suited for conversion of these materials. Thermochemical conversion processes can generate a variety of products such as gasoline hydrocarbon fuels, natural gas substitutes, or heat energy for electric power generation. The US Department of Energy is sponsoring research on biomass conversion technologies through its Biomass Thermochemical Conversion Program. Pacific Northwest Laboratory has been designated the Technical Field Management Office for the Biomass Thermochemical Conversion Program with overall responsibility for the Program. This report briefly describes the Thermochemical Conversion Program structure and summarizes the activities and major accomplishments during fiscal year 1986. 88 refs., 31 figs., 5 tabs.

Advantage of resonant power conversion in aerospace applications

Science.gov (United States)

Hansen, I. G.

1983-01-01

An ultrasonic, sinusoidal aerospace power distribution system is shown to have many advantages over other candidate power systems. These advantages include light weight, ease of fault clearing, versatility in handling many loads including motors, and the capability of production within the limits of present technology. References are cited that demonstrate the state of resonant converter technology and support these conclusions.

Possibilities for retrofitting of the existing thermal electric power plants using solar power technologies

International Nuclear Information System (INIS)

Matjanov, Erkinjon K.; Abduganieva, Farogat A.; Aminov, Zarif Z.

2012-01-01

possibilities for retrofitting of the Tashkent thermal electric power plant on the basis of solar power technologies are being discussed with the German partners in the framework of the Joint-research project, funded by Volkswagenstiftung foundation (Germany) entitled 'Optimum feed-in of solar heat for conversion of low-efficient fossil-fired steam power plants to low-emission solar hybrid power plants by example of Uzbekistan'. The main data on the Tashkent thermal electric power plant: 12 steam turbines with total electric power output 1830 MW are installed. Main fuel - natural gas. Specific mass flow of the fuel - 394 gram/kWph. Electric efficiency of the power plant - 31,2 %. There is a reservoir for a masut (black oil) for 80 000 tons in the power plant, which consists of 7 masut tanks each of 10000 m 3 and 6 masut tanks each of 5000 m 3 . The following possibilities of retrofitting of the Tashkent thermal electric power plant with using solar technologies are being considered: 1. Installing a solar-fed steam generator instead of the existing steam generator. 2. Installing a solar-fed steam generator parallel to the existing steam generator. 3. Installing solar-heated feed water pre-heaters instead of the existing high-pressure and low-pressure feed water pre-heaters. 4. Installing solar-heated feed water pre-heaters parallel to the existing high-pressure and low-pressure feed water pre-heaters. The results of the researches are expected to improve electric efficiency of the Tashkent thermal electric power plant simultaneously reducing emissions into the environment. (authors)

EDITORIAL: The 7th International Workshop on Micro and Nanotechnologies for Power Generation and Energy Conversion Applications (PowerMEMS 2007)

Science.gov (United States)

Hebling, C.; Woias, P.

2008-10-01

This special issue of Journal of Micromechanics and Microengineering (JMM) contains a selection of papers from the 7th International Workshop on Micro and Nanotechnologies for Power Generation and Energy Conversion (PowerMEMS 2007). The workshop was held in Freiburg, Germany on 27-29 November 2007 under the joint organization of the Fraunhofer Institute for Solar Energy Systems (FhG-ISE), Freiburg and the Department of Microsystems Engineering (IMTEK) of the Albert-Ludwig-University of Freiburg. PowerMEMS 2007 continues a series of workshops initiated in 2000 in Japan to create an annual discussion forum in the emerging field of micro energy technology. With a single exception in 2001, the workshop has continued as an annual meeting ever since, with a continuous increase in the number of presentations and participants. The program of PowerMEMS 2007 was composed of 2 invited talks, 25 oral talks and 61 poster presentations. From these 88 presentations 16 have been selected for this special issue. It was at the end of 1959 when the Caltech physicist Richard Feynman gave his famous lecture entitled 'There Is Plenty of Room at the Bottom' in which he discussed the possibilities of miniaturization for both storage capacity ('Encyclopaedia Britannica on the head of a pin') as well as micro machining ('rearranging the atoms'), although there were absolutely no technological possibilities in sight for an adequate realization of such ideas. Now, nearly 50 years later, we not only have incredible knowledge about the nanoworld, but even more we are now able to generate microelectromechanical devices which, next to their electronic properties, can integrate physical and analytical functions. Today, Feynman might easily have added a second lecture entitled 'There is Plenty of Energy at the Bottom'. Micro energy technology has seen a tremendous rise in MEMS and material sciences and is regarded today as one of their hot topics. Also, there are more and more companies in this

Integrated bioenergy conversion concepts for small scale gasification power systems

Science.gov (United States)

Aldas, Rizaldo Elauria

Thermal and biological gasification are promising technologies for addressing the emerging concerns in biomass-based renewable energy, environmental protection and waste management. However, technical barriers such as feedstock quality limitations, tars, and high NOx emissions from biogas fueled engines impact their full utilization and make them suffer at the small scale from the need to purify the raw gas for most downstream processes, including power generation other than direct boiler use. The two separate gasification technologies may be integrated to better address the issues of power generation and waste management and to complement some of each technologies' limitations. This research project investigated the technical feasibility of an integrated thermal and biological gasification concept for parameters critical to appropriately matching an anaerobic digester with a biomass gasifier. Specific studies investigated the thermal gasification characteristics of selected feedstocks in four fixed-bed gasification experiments: (1) updraft gasification of rice hull, (2) indirect-heated gasification of rice hull, (3) updraft gasification of Athel wood, and (4) downdraft gasification of Athel and Eucalyptus woods. The effects of tars and other components of producer gas on anaerobic digestion at mesophilic temperature of 36°C and the biodegradation potentials and soil carbon mineralization of gasification tars during short-term aerobic incubation at 27.5°C were also examined. Experiments brought out the ranges in performance and quality and quantity of gasification products under different operating conditions and showed that within the conditions considered in the study, these gasification products did not adversely impact the overall digester performance. Short-term aerobic incubation demonstrated variable impacts on carbon mineralization depending on tar and soil conditions. Although tars exhibited low biodegradation indices, degradation may be improved if the

Solid State Microchp Based On Thermophotovoltaic And Thermoelectric Conversion

OpenAIRE

Worek, William M.; Brown, Christopher; Trojanowski, Rebecca; Butcher, Thomas; Horne, Edward

2012-01-01

MicroCHP involves the coproduction of both heat and electric power in (typically) residential heating systems. A range of different energy conversion technologies are currently receiving attention for this application including Stirling engines, internal combustion engines, fuel cells, and Rankine cycles with steam or organic compounds as working fluids. In this work the use of ThermoPhotoVoltaic (TPV) and ThermoElectric (TE) conversion devices either alone or in combination for power product...

Thermal power plant efficiency enhancement with Ocean Thermal Energy Conversion

International Nuclear Information System (INIS)

Soto, Rodrigo; Vergara, Julio

2014-01-01

In addition to greenhouse gas emissions, coastal thermal power plants would gain further opposition due to their heat rejection distressing the local ecosystem. Therefore, these plants need to enhance their thermal efficiency while reducing their environmental offense. In this study, a hybrid plant based on the principle of Ocean Thermal Energy Conversion was coupled to a 740 MW coal-fired power plant project located at latitude 28°S where the surface to deepwater temperature difference would not suffice for regular OTEC plants. This paper presents the thermodynamical model to assess the overall efficiency gained by adopting an ammonia Rankine cycle plus a desalinating unit, heated by the power plant condenser discharge and refrigerated by cold deep seawater. The simulation allowed us to optimize a system that would finally enhance the plant power output by 25–37 MW, depending on the season, without added emissions while reducing dramatically the water temperature at discharge and also desalinating up to 5.8 million tons per year. The supplemental equipment was sized and the specific emissions reduction was estimated. We believe that this approach would improve the acceptability of thermal and nuclear power plant projects regardless of the plant location. -- Highlights: • An Ocean Thermal Energy Conversion hybrid plant was designed. • The waste heat of a power plant was delivered as an OTEC heat source. • The effect of size and operating conditions on plant efficiency were studied. • The OTEC implementation in a Chilean thermal power plant was evaluated. • The net efficiency of the thermal power plant was increased by 1.3%

Methodology for the comparative assessment of the Satellite Power System (SPS) and alternative technologies

Energy Technology Data Exchange (ETDEWEB)

Wolsko, T.; Buehring, W.; Cirillo, R.; Gasper, J.; Habegger, L.; Hub, K.; Newsom, D.; Samsa, M.; Stenehjem, E.; Whitfield, R.

1980-01-01

A description of the initial methodology for the Comparative Assessment of the Satellite Power System Concept Development and Evaluation Program of NASA and DOE is presented. Included are study objectives, issue identification, units of measurement, methods, and data bases. The energy systems concerned are the satellite power system, several coal technologies, geothermal energy, fission, fusion, terrestrial solar systems, and ocean thermal energy conversion. Guidelines are suggested for the characterization of these systems, side-by-side analysis, alternative futures analysis, and integration and aggregation of data. The bulk of this report is a description of the methods for assessing the technical, economic, environmental, societal, and institutional issues surrounding the development of the selected energy technologies.

Ultralow power continuous-wave frequency conversion in hydrogenated amorphous silicon waveguides.

Science.gov (United States)

Wang, Ke-Yao; Foster, Amy C

2012-04-15

We demonstrate wavelength conversion through nonlinear parametric processes in hydrogenated amorphous silicon (a-Si:H) with maximum conversion efficiency of -13 dB at telecommunication data rates (10 GHz) using only 15 mW of pump peak power. Conversion bandwidths as large as 150 nm (20 THz) are measured in continuous-wave regime at telecommunication wavelengths. The nonlinear refractive index of the material is determined by four-wave mixing (FWM) to be n(2)=7.43×10(-13) cm(2)/W, approximately an order of magnitude larger than that of single crystal silicon. © 2012 Optical Society of America

Direct Energy Conversion for Low Specific Mass In-Space Power and Propulsion

Science.gov (United States)

Scott, John H.; George, Jeffrey A.; Tarditi, Alfonso G.

2013-01-01

"Changing the game" in space exploration involves changing the paradigm for the human exploration of the Solar System, e.g, changing the human exploration of Mars from a three-year epic event to an annual expedition. For the purposes of this assessment an "annual expedition" capability is defined as an in-space power & propulsion system which, with launch mass limits as defined in NASA s Mars Architecture 5.0, enables sending a crew to Mars and returning them after a 30-day surface stay within one year, irrespective of planetary alignment. In this work the authors intend to show that obtaining this capability requires the development of an in-space power & propulsion system with an end-to-end specific mass considerably less than 3 kg/kWe. A first order energy balance analysis reveals that the technologies required to create a system with this specific mass include direct energy conversion and nuclear sources that release energy in the form of charged particle beams. This paper lays out this first order approximation and details these conclusions.

A Comparison of Coolant Options for Brayton Power Conversion Heat Rejection Systems

International Nuclear Information System (INIS)

Siamidis, John; Mason, Lee

2006-01-01

This paper describes potential heat rejection design concepts for Brayton power conversion systems. Brayton conversion systems are currently under study by NASA for Nuclear Electric Propulsion (NEP) and surface power applications. The Brayton Heat Rejection Subsystem (HRS) must dissipate waste heat generated by the power conversion system due to inefficiencies in the thermal-to-electric conversion process. Sodium potassium (NaK) and H2O are two coolant working fluids that have been investigated in the design of a pumped loop and heat pipe space HRS. In general NaK systems are high temperature (300 to 1000 K) low pressure systems, and H2O systems are low temperature (300 to 600 K) high pressure systems. NaK is an alkali metal with health and safety hazards that require special handling procedures. On the other hand, H2O is a common fluid, with no health hazards and no special handling procedures. This paper compares NaK and H2O for the HRS pumped loop coolant working fluid. A detailed excel analytical model, HRS O pt, was developed to evaluate the various HRS design parameters. It is capable of analyzing NaK or H2O coolant, parallel or series flow configurations, and numerous combinations of other key parameters (heat pipe spacing, diameter and radial flux, radiator facesheet thickness, fluid duct system pressure drop, system rejected power, etc.) of the HRS. This paper compares NaK against water for the HRS coolant working fluid with respect to the relative mass, performance, design and implementation issues between the two fluids

Applications of magnetic power production and its assessment - Annual report 2007

Energy Technology Data Exchange (ETDEWEB)

Kitanovski, A.; Vuarnoz, D.; Diebold, M.; Gonin, C.; Egolf, P. W.

2007-07-01

This annual report for the Swiss Federal Office of Energy (SFOE) takes a look at the work done at the University of Applied Sciences of Western Switzerland in 2007 on a project involving power production based on magnetic effects. In this annual report, a selection of feasible and economic magnetic power conversion systems is listed. Magnetic 'power generators' based on permanent and superconducting magnets are analysed for several heat source temperatures, magnetic field strengths and machine rotational frequencies. The analysis uses a newly derived model, which permits the determination of thermodynamic efficiency and exergy efficiency of a magnetic power-conversion system. This study shows that magnetic power conversion is better than conventional technologies in many aspects, such as, for example, for low exergy heat sources, where most of the conventional energy conversion technologies cannot even operate. The authors state that, in contrast, magnetic power generation technology leads to a high exergy efficiency of energy conversion for such sources.

Independent Power Generation in a Modern Electrical Substation Based on Thermoelectric Technology

Science.gov (United States)

Li, Z. M.; Zhao, Y. Q.; Liu, W.; Wei, B.; Qiu, M.; Lai, X. K.

2017-05-01

Because of many types of electrical equipment with high power in substations, the potentiality of energy conservation is quite large. From this viewpoint, thermoelectric materials may be chosen to produce electrical energy using the waste heat produced in substations. Hence, a thermoelectric generation system which can recycle the waste heat from electric transformers was proposed to improve the energy efficiency and reduce the burden of the oil cooling system. An experimental prototype was fabricated to perform the experiment and to verify the feasibility. The experimental results showed that the output power could achieve 16 W from waste heat of 900 W, and that the power conversion efficiency was approximately 1.8%. Therefore, power generation is feasible by using the waste heat from the transformers based on thermoelectric technology.

Magnetic-field-free thermoelectronic power conversion based on graphene and related two-dimensional materials

Science.gov (United States)

Wanke, R.; Hassink, G. W. J.; Stephanos, C.; Rastegar, I.; Braun, W.; Mannhart, J.

2016-06-01

Mobile energy converters require, in addition to high conversion efficiency and low cost, a low mass. We propose to utilize thermoelectronic converters that use 2D-materials such as graphene for their gate electrodes. Deriving the ultimate limit for their specific energy output, we show that the positive energy output is likely close to the fundamental limit for any conversion of heat into electric power. These converters may be valuable as electric power sources of spacecraft, and with the addition of vacuum enclosures, for power generation in electric planes and cars.

Adoption of nitrogen power conversion system for small scale ultra-long cycle fast reactor eliminating intermediate sodium loop

International Nuclear Information System (INIS)

Seo, Seok Bin; Seo, Han; Bang, In Cheol

2016-01-01

Highlights: • N 2 power conversion system for both safety and thermal performance aspects. • Sensitivity studies of several controlled parameters on N 2 power conversion system. • The elimination of the intermediate loop increased the cycle thermal efficiency. • The elimination of the intermediate loop expects economic advantages. - Abstract: As one of SFRs, the ultra-long cycle fast reactor with a power rating of 100 MW e (UCFR-100) was introduced for a 60-year operation. As an alternative to the traditional steam Rankine cycle for the power conversion system, gas based Brayton cycle has been considered for UCFR-100. Among Supercritical CO 2 (S-CO 2 ), Helium (He), Nitrogen (N 2 ) as candidates for the power conversion system for UCFR-100, an N 2 power conversion system was chosen considering both safety and thermal performance aspects. The elimination of the intermediate sodium loop could be achieved due to the safety and stable characteristics of nitrogen working fluid. In this paper, sensitivity studies with respect to several controlled parameters on N 2 power conversion system were performed to optimize the system. Furthermore, the elimination of the intermediate loop was evaluated with respect to its impact on the thermodynamic performance and other aspects.

High Performance Low Cost Digitally Controlled Power Conversion Technology

DEFF Research Database (Denmark)

Jakobsen, Lars Tønnes

2008-01-01

in order to reduce the power consumption of servers and datacenters. The work presented in this thesis includes digital control methods for switch-mode converters implemented in microcontrollers, digital signal controllers and field programmable gate arrays. Microcontrollers are cheap devices that can...... be used for real-time control of switch-mode converters. Software design in the assembly language of the microcontroller is important because of the limited resources of the microcontroller. Microcontrollers are best suited for power electronics applications with low bandwidth requirements because...... the execution time of the software algorithm that realises the digital control law will constitute a considerable delay in the control loop. Digital signal controllers are powerful devices capable of performing arithmetic functions much faster than a microcontroller can. Digital signal controllers are well...

Reliability and mass analysis of dynamic power conversion systems with parallel or standby redundancy

Science.gov (United States)

Juhasz, Albert J.; Bloomfield, Harvey S.

1987-01-01

A combinatorial reliability approach was used to identify potential dynamic power conversion systems for space mission applications. A reliability and mass analysis was also performed, specifically for a 100-kWe nuclear Brayton power conversion system with parallel redundancy. Although this study was done for a reactor outlet temperature of 1100 K, preliminary system mass estimates are also included for reactor outlet temperatures ranging up to 1500 K.

Reliability and mass analysis of dynamic power conversion systems with parallel of standby redundancy

Science.gov (United States)

Juhasz, A. J.; Bloomfield, H. S.

1985-01-01

A combinatorial reliability approach is used to identify potential dynamic power conversion systems for space mission applications. A reliability and mass analysis is also performed, specifically for a 100 kWe nuclear Brayton power conversion system with parallel redundancy. Although this study is done for a reactor outlet temperature of 1100K, preliminary system mass estimates are also included for reactor outlet temperatures ranging up to 1500 K.

Status of GT-MHR with emphasis on the power conversion system

International Nuclear Information System (INIS)

Neylan, A.J.; Silady, F.A.; Kohler, B.P.; Lomba, D.; Rose, R.

1996-01-01

The conceptual design of the Gas Turbine-Modular Helium Reactor (GT-MHR) has made significant progress in the past year. Evaluation of an external versus internal (submerged) generator and modifications as a result of an internal seal task force were completed. Significant progress was also made on the design of the generator utilizing existing technology. Conceptual design of the turbocompressor was confirmed, including extensive evaluation of the entire turbomachine (turbocompressor and generator) rotor dynamics. Results concluded in a revised configuration for the location of magnetic bearings supporting the entire machine. Integration of the turbomachine with the recuperator, precooler, intercooler and internal ducts and seals progressed to improved maintenance and operation. This resulted in some changes and improvements in the overall arrangement of the power conversion module. The paper also provides a summary of the fuel and safety assessment progress. (author). 6 refs, 7 figs, 3 tabs

Too Much of a Good Thing ? Radioisotope Power Conversion Technology and `Waste' Heat in the Titan Environment

Science.gov (United States)

Lorenz, Ralph

Unlike most solar system surface environments, Titan has an atmosphere that is both cold and dense. This means heat transfer to and from a vehicle is determined by convection, rather than by radiation which dominates on Earth and Mars. With surface temperatures near 94K, batteries and systems require heating to operate. Solar power is impractical, so a spacecraft intended to operate for longer than a few hours on Titan must have a radioisotope power source (RPS). Such sources convert heat from Plutonium decay into electricity, with an efficiency that varies from about 5% for thermoelectric systems to 20% for engine cycles such as Stirling. For vehicles with 100-200W electrical power, the 500-4000 W ‘waste’ heat in the Titan environment can be valuable in that it can be exploited to maintain thermal conditions inside the vehicle. The generally benign Titan environment, and the outstanding scientific and popular interest in its exploration, has attracted a number of mission concepts including a lander for Titan’s equatorial dunefields, light gas and hot air (‘Montgolfière’) balloons, airplanes, and capsules that float on its polar seas (e.g. the proposed Titan Mare Explorer.) However, the choice of conversion technology is key to the success of these different platforms. Waste heat can perturb meteorological measurements in several ways. First by creating a warm air plume (an effect observed on Viking and Curiosity.) Second, rain or seaspray falling onto hot radiator surfaces can evaporate causing a local enhancement of methane humidity. Third, sufficiently strong heating could perturb local winds. Similar effects, and the potential generation of effervescence or even fog, may result for capsules floating in liquid hydrocarbons. For landers and drifting buoys, these perturbations may significantly degrade environmental measurements, or at least demand tall meteorology masts, for the higher waste heat output of thermoelectric systems, and a Stirling system

High Efficiency Nuclear Power Plants Using Liquid Fluoride Thorium Reactor Technology

Science.gov (United States)

Juhasz, Albert J.; Rarick, Richard A.; Rangarajan, Rajmohan

2009-01-01

An overall system analysis approach is used to propose potential conceptual designs of advanced terrestrial nuclear power plants based on Oak Ridge National Laboratory (ORNL) Molten Salt Reactor (MSR) experience and utilizing Closed Cycle Gas Turbine (CCGT) thermal-to-electric energy conversion technology. In particular conceptual designs for an advanced 1 GWe power plant with turbine reheat and compressor intercooling at a 950 K turbine inlet temperature (TIT), as well as near term 100 MWe demonstration plants with TITs of 950 and 1200 K are presented. Power plant performance data were obtained for TITs ranging from 650 to 1300 K by use of a Closed Brayton Cycle (CBC) systems code which considered the interaction between major sub-systems, including the Liquid Fluoride Thorium Reactor (LFTR), heat source and heat sink heat exchangers, turbo-generator machinery, and an electric power generation and transmission system. Optional off-shore submarine installation of the power plant is a major consideration.

Plasma-assisted CO2 conversion: optimizing performance via microwave power modulation

Science.gov (United States)

Britun, Nikolay; Silva, Tiago; Chen, Guoxing; Godfroid, Thomas; van der Mullen, Joost; Snyders, Rony

2018-04-01

Significant improvement in the energy efficiency of plasma-assisted CO2 conversion is achieved with applied power modulation in a surfaguide microwave discharge. The obtained values of CO2 conversion and energy efficiency are, respectively, 0.23 and 0.33 for a 0.95 CO2  +  0.05 N2 gas mixture. Analysis of the energy relaxation mechanisms shows that power modulation can potentially affect the vibrational-translational energy exchange in plasma. In our case, however, this mechanism does not play a major role, likely due to the low degree of plasma non-equilibrium in the considered pressure range. Instead, the gas residence time in the discharge active zone together with plasma pulse duration are found to be the main factors affecting the CO2 conversion efficiency at low plasma pulse repetition rates. This effect is confirmed experimentally by the in situ time-resolved two-photon absorption laser-induced fluorescence measurements of CO molecular density produced in the discharge as a result of CO2 decomposition.

Needs, resources and climate change: Clean and efficient conversion technologies

KAUST Repository

Ghoniem, Ahmed F.

2011-02-01

Energy "powers" our life, and energy consumption correlates strongly with our standards of living. The developed world has become accustomed to cheap and plentiful supplies. Recently, more of the developing world populations are striving for the same, and taking steps towards securing their future energy needs. Competition over limited supplies of conventional fossil fuel resources is intensifying, and more challenging environmental problems are springing up, especially related to carbon dioxide (CO 2) emissions. There is strong evidence that atmospheric CO 2 concentration is well correlated with the average global temperature. Moreover, model predictions indicate that the century-old observed trend of rising temperatures could accelerate as carbon dioxide concentration continues to rise. Given the potential danger of such a scenario, it is suggested that steps be taken to curb energy-related CO 2 emissions through a number of technological solutions, which are to be implemented in a timely fashion. These solutions include a substantial improvement in energy conversion and utilization efficiencies, carbon capture and sequestration, and expanding the use of nuclear energy and renewable sources. Some of these technologies already exist, but are not deployed at sufficiently large scale. Others are under development, and some are at or near the conceptual state. © 2010 Elsevier Ltd. All rights reserved.

Hollywood's Conversion to Color: The Technological, Economic and Aesthetic Factors.

Science.gov (United States)

Kindem, Forham A.

1979-01-01

Discusses the film industry's conversion to color cinematography in the period between the 1920s and 1960s. Cites economic considerations, technological modifications, and aesthetic preferences by audiences as factors in this development. (JMF)

The Future of Electronic Power Processing and Conversion: Highlights from FEPPCON IX

DEFF Research Database (Denmark)

Enslin, Johan H.; Blaabjerg, Frede; Tan, Don F.D.

2017-01-01

Since 1991, every second year the IEEE Power Electronics Society (PELS) has organized the technical long-range planning meeting "Future of Electronic Power Processing and Conversion" (FEPPCON). FEPPCON IX was held 12-16 June 2017 in beautiful Kruger Park in South Africa (Figure 1). The overall go...

Photovoltaic energy conversion and wind power plants creating new jobs; Arbeitsplaetze durch Photovoltaik und Windenergie

Energy Technology Data Exchange (ETDEWEB)

Hille, G.; Hoffmann, V.U. [Fraunhofer ISE, Freiburg (Germany); Dienhart, H.; Langniss, O.; Nitsch, J. [DLR, Stuttgart (Germany)

1997-12-01

Experts are unanimous that opening up new markets through innovative technologies will be the successful strategy for reversing the upward trend of unemployment in Germany. This approach puts renewable energy sources into the foreground, as enhanced use of wind power and photovoltaic energy conversion will no doubt create new jobs. These technologies will, however, require favourable regulatory framework conditions in order to become a significant force in combatting unemployment. (orig./CB) [Deutsch] Es gilt unter Experten als sicher, dass eine Umkehr am Arbeitsmarkt nur dadurch zu schaffen ist, dass innovative Technologien genutzt und damit neue Maerkte erschlossen werden. Demnach koennte etwa dem Ausbau der regenerativen Energietraeger Wind und Photovoltaik zur Schaffung zukunftssicherer Arbeitsplaetze eine grosse Bedeutung zukommen. Einen ernstzunehmenden Beitrag im Kampf gegen die Arbeitslosigkeit koennen diese Technologien allerdings nur unter bestimmten Rahmenbedingungen leisten. (orig./RHM)

Fully solar-powered photoelectrochemical conversion for simultaneous energy storage and chemical sensing.

Science.gov (United States)

Wang, Yongcheng; Tang, Jing; Peng, Zheng; Wang, Yuhang; Jia, Dingsi; Kong, Biao; Elzatahry, Ahmed A; Zhao, Dongyuan; Zheng, Gengfeng

2014-06-11

We report the development of a multifunctional, solar-powered photoelectrochemical (PEC)-pseudocapacitive-sensing material system for simultaneous solar energy conversion, electrochemical energy storage, and chemical detection. The TiO2 nanowire/NiO nanoflakes and the Si nanowire/Pt nanoparticle composites are used as photoanodes and photocathodes, respectively. A stable open-circuit voltage of ∼0.45 V and a high pseudocapacitance of up to ∼455 F g(-1) are obtained, which also exhibit a repeating charging-discharging capability. The PEC-pseudocapacitive device is fully solar powered, without the need of any external power supply. Moreover, this TiO2 nanowire/NiO nanoflake composite photoanode exhibits excellent glucose sensitivity and selectivity. Under the sun light illumination, the PEC photocurrent shows a sensitive increase upon different glucose additions. Meanwhile in the dark, the open-circuit voltage of the charged pseudocapacitor also exhibits a corresponding signal over glucose analyte, thus serving as a full solar-powered energy conversion-storage-utilization system.

Biological Conversion of Sugars to Hydrocarbons Technology Pathway

Energy Technology Data Exchange (ETDEWEB)

Davis, R.; Biddy, M.; Tan, E.; Tao, L.; Jones, S.

2013-03-01

This technology pathway case investigates the biological conversion of biomass-derived sugars to hydrocarbon biofuels, utilizing data from recent literature references and information consistent with recent pilot-scale demonstrations at NREL. Technical barriers and key research needs have been identified that should be pursued for the pathway to become competitive with petroleum-derived gasoline-, diesel-, and jet-range hydrocarbon blendstocks.

In silico designing of power conversion efficient organic lead dyes for solar cells using todays innovative approaches to assure renewable energy for future

Science.gov (United States)

Kar, Supratik; Roy, Juganta K.; Leszczynski, Jerzy

2017-06-01

Advances in solar cell technology require designing of new organic dye sensitizers for dye-sensitized solar cells with high power conversion efficiency to circumvent the disadvantages of silicon-based solar cells. In silico studies including quantitative structure-property relationship analysis combined with quantum chemical analysis were employed to understand the primary electron transfer mechanism and photo-physical properties of 273 arylamine organic dyes from 11 diverse chemical families explicit to iodine electrolyte. The direct quantitative structure-property relationship models enable identification of the essential electronic and structural attributes necessary for quantifying the molecular prerequisites of 11 classes of arylamine organic dyes, responsible for high power conversion efficiency of dye-sensitized solar cells. Tetrahydroquinoline, N,N'-dialkylaniline and indoline have been least explored classes under arylamine organic dyes for dye-sensitized solar cells. Therefore, the identified properties from the corresponding quantitative structure-property relationship models of the mentioned classes were employed in designing of "lead dyes". Followed by, a series of electrochemical and photo-physical parameters were computed for designed dyes to check the required variables for electron flow of dye-sensitized solar cells. The combined computational techniques yielded seven promising lead dyes each for all three chemical classes considered. Significant (130, 183, and 46%) increment in predicted %power conversion efficiency was observed comparing with the existing dye with highest experimental %power conversion efficiency value for tetrahydroquinoline, N,N'-dialkylaniline and indoline, respectively maintaining required electrochemical parameters.

Fission Surface Power Technology Demonstration Unit Test Results

Science.gov (United States)

Briggs, Maxwell H.; Gibson, Marc A.; Geng, Steven M.; Sanzi, James L.

2016-01-01

The Fission Surface Power (FSP) Technology Demonstration Unit (TDU) is a system-level demonstration of fission power technology intended for use on manned missions to Mars. The Baseline FSP systems consists of a 190 kWt UO2 fast-spectrum reactor cooled by a primary pumped liquid metal loop. This liquid metal loop transfers heat to two intermediate liquid metal loops designed to isolate fission products in the primary loop from the balance of plant. The intermediate liquid metal loops transfer heat to four Stirling Power Conversion Units (PCU), each of which produce 12 kWe (48 kW total) and reject waste heat to two pumped water loops, which transfer the waste heat to titanium-water heat pipe radiators. The FSP TDU simulates a single leg of the baseline FSP system using an electrically heater core simulator, a single liquid metal loop, a single PCU, and a pumped water loop which rejects the waste heat to a Facility Cooling System (FCS). When operated at the nominal operating conditions (modified for low liquid metal flow) during TDU testing the PCU produced 8.9 kW of power at an efficiency of 21.7 percent resulting in a net system power of 8.1 kW and a system level efficiency of 17.2 percent. The reduction in PCU power from levels seen during electrically heated testing is the result of insufficient heat transfer from the NaK heater head to the Stirling acceptor, which could not be tested at Sunpower prior to delivery to the NASA Glenn Research Center (GRC). The maximum PCU power of 10.4 kW was achieved at the maximum liquid metal temperature of 875 K, minimum water temperature of 350 K, 1.1 kg/s liquid metal flow, 0.39 kg/s water flow, and 15.0 mm amplitude at an efficiency of 23.3 percent. This resulted in a system net power of 9.7 kW and a system efficiency of 18.7 percent.

Report on a survey in fiscal 1999. Part 2. Survey on the biomass-derived energy conversion technology; 1999 nendo biomass shigen wo genryo to suru energy henkan gijutsu ni kansuru chosa hokokusho. 2

Energy Technology Data Exchange (ETDEWEB)

NONE

2000-03-01

Biomass energy is positioned as a promising environment harmonizing energy in the 21st century because it does not break down the CO2 balance in the global scale. The present survey has investigated quantity of biomass resources utilizable as energy resources, investigated and analyzed the biomass-derived energy conversion technology, searched for a promising practically usable technology, and discussed the means to achieve the technological introduction. The foreword chapter describes that now is the good time to recognize importance of and introduce the biomass-derived technology. First and second chapters estimate energy potential and utilizable quantity of wastes-based biomass in Indonesia, Malaysia, the Philippines, and Brazil. Chapter 3 investigates feasibility of methane fermentation and ethanol fermentation as a promising bio-chemical conversion process. Chapter 4 has performed feasibility studies on biomass electric power generation, methanol synthesis by gasification, thermal decomposition and gasification as promising thermo-chemical conversion processes. Chapter 5 proposed a biomass electric power generation system, a biomass-gasified methanol synthesizing system, and a dimethyl ether production system. (NEDO)

Magnetic fusion technology

CERN Document Server

Dolan, Thomas J

2014-01-01

Magnetic Fusion Technology describes the technologies that are required for successful development of nuclear fusion power plants using strong magnetic fields. These technologies include: ? magnet systems, ? plasma heating systems, ? control systems, ? energy conversion systems, ? advanced materials development, ? vacuum systems, ? cryogenic systems, ? plasma diagnostics, ? safety systems, and ? power plant design studies. Magnetic Fusion Technology will be useful to students and to specialists working in energy research.

Foundations of pulsed power technology

CERN Document Server

Lehr, Janet

2018-01-01

Pulsed power technologies could be an answer to many cutting-edge applications. The challenge is in how to develop this high-power/high-energy technology to fit current market demands of low-energy consuming applications. This book provides a comprehensive look at pulsed power technology and shows how it can be improved upon for the world of today and tomorrow. Foundations of Pulsed Power Technology focuses on the design and construction of the building blocks as well as their optimum assembly for synergetic high performance of the overall pulsed power system. Filled with numerous design examples throughout, the book offers chapter coverage on various subjects such as: Marx generators and Marx-like circuits; pulse transformers; pulse-forming lines; closing switches; opening switches; multi-gigawatt to multi-terawatt systems; energy storage in capacitor banks; electrical breakdown in gases; electrical breakdown in solids, liquids and vacuum; pulsed voltage and current measurements; electromagnetic interferen...

Food waste-to-energy conversion technologies: current status and future directions.

Science.gov (United States)

Pham, Thi Phuong Thuy; Kaushik, Rajni; Parshetti, Ganesh K; Mahmood, Russell; Balasubramanian, Rajasekhar

2015-04-01

Food waste represents a significantly fraction of municipal solid waste. Proper management and recycling of huge volumes of food waste are required to reduce its environmental burdens and to minimize risks to human health. Food waste is indeed an untapped resource with great potential for energy production. Utilization of food waste for energy conversion currently represents a challenge due to various reasons. These include its inherent heterogeneously variable compositions, high moisture contents and low calorific value, which constitute an impediment for the development of robust, large scale, and efficient industrial processes. Although a considerable amount of research has been carried out on the conversion of food waste to renewable energy, there is a lack of comprehensive and systematic reviews of the published literature. The present review synthesizes the current knowledge available in the use of technologies for food-waste-to-energy conversion involving biological (e.g. anaerobic digestion and fermentation), thermal and thermochemical technologies (e.g. incineration, pyrolysis, gasification and hydrothermal oxidation). The competitive advantages of these technologies as well as the challenges associated with them are discussed. In addition, the future directions for more effective utilization of food waste for renewable energy generation are suggested from an interdisciplinary perspective. Copyright © 2014 Elsevier Ltd. All rights reserved.

Physical Limits of Solar Energy Conversion in the Earth System.

Science.gov (United States)

Kleidon, Axel; Miller, Lee; Gans, Fabian

2016-01-01

Solar energy provides by far the greatest potential for energy generation among all forms of renewable energy. Yet, just as for any form of energy conversion, it is subject to physical limits. Here we review the physical limits that determine how much energy can potentially be generated out of sunlight using a combination of thermodynamics and observed climatic variables. We first explain how the first and second law of thermodynamics constrain energy conversions and thereby the generation of renewable energy, and how this applies to the conversions of solar radiation within the Earth system. These limits are applied to the conversion of direct and diffuse solar radiation - which relates to concentrated solar power (CSP) and photovoltaic (PV) technologies as well as biomass production or any other photochemical conversion - as well as solar radiative heating, which generates atmospheric motion and thus relates to wind power technologies. When these conversion limits are applied to observed data sets of solar radiation at the land surface, it is estimated that direct concentrated solar power has a potential on land of up to 11.6 PW (1 PW=10(15) W), whereas photovoltaic power has a potential of up to 16.3 PW. Both biomass and wind power operate at much lower efficiencies, so their potentials of about 0.3 and 0.1 PW are much lower. These estimates are considerably lower than the incoming flux of solar radiation of 175 PW. When compared to a 2012 primary energy demand of 17 TW, the most direct uses of solar radiation, e.g., by CSP or PV, have thus by far the greatest potential to yield renewable energy requiring the least space to satisfy the human energy demand. Further conversions into solar-based fuels would be reduced by further losses which would lower these potentials. The substantially greater potential of solar-based renewable energy compared to other forms of renewable energy simply reflects much fewer and lower unavoidable conversion losses when solar

Advances in High-Power, Ultrashort Pulse DPSSL Technologies at HiLASE

Directory of Open Access Journals (Sweden)

Martin Smrž

2017-10-01

Full Text Available The development of kW-class diode-pumped picosecond laser sources emitting at various wavelengths started at the HiLASE Center four years ago. A 500-W Perla C thin-disk laser with a diffraction limited beam and repetition rate of 50–100 kHz, a frequency conversion to mid-infrared (mid-IR, and second to fifth harmonic frequencies was demonstrated. We present an updated review on the progress in the development of compact picosecond and femtosecond high average power radiation sources covering the ultraviolet (UV to mid-IR spectral range at the HiLASE Center. We also report on thin-disk manufacturing by atomic diffusion bonding, which is a crucial technology for future high-power laser development.

Abstracts of the international scientific-practical conference on space research, technology and conversion-II

International Nuclear Information System (INIS)

1997-04-01

The International Conference on space research, technology and conversion-II was held on 16-18 April, 1997 in Tashkent, Uzbekistan. The specialists discussed various aspects of space research, technology and conversion problems. More than 60 talks were presented in the meeting on the following subjects: remote sensing and the processing of satellite information; space navigation and others, including radiation effects in silicon solar cells caused by cosmic radiation. (A.A.D.)

Thermally Driven Transport and Relaxation Switching Self-Powered Electromagnetic Energy Conversion.

Science.gov (United States)

Cao, Maosheng; Wang, Xixi; Cao, Wenqiang; Fang, Xiaoyong; Wen, Bo; Yuan, Jie

2018-06-07

Electromagnetic energy radiation is becoming a "health-killer" of living bodies, especially around industrial transformer substation and electricity pylon. Harvesting, converting, and storing waste energy for recycling are considered the ideal ways to control electromagnetic radiation. However, heat-generation and temperature-rising with performance degradation remain big problems. Herein, graphene-silica xerogel is dissected hierarchically from functions to "genes," thermally driven relaxation and charge transport, experimentally and theoretically, demonstrating a competitive synergy on energy conversion. A generic approach of "material genes sequencing" is proposed, tactfully transforming the negative effects of heat energy to superiority for switching self-powered and self-circulated electromagnetic devices, beneficial for waste energy harvesting, conversion, and storage. Graphene networks with "well-sequencing genes" (w = P c /P p > 0.2) can serve as nanogenerators, thermally promoting electromagnetic wave absorption by 250%, with broadened bandwidth covering the whole investigated frequency. This finding of nonionic energy conversion opens up an unexpected horizon for converting, storing, and reusing waste electromagnetic energy, providing the most promising way for governing electromagnetic pollution with self-powered and self-circulated electromagnetic devices. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

EPR's energy conversion system. Alstom's solutions

International Nuclear Information System (INIS)

Ledermann, P.

2009-01-01

ARABELLE steam turbines have been developed by Alstom to be used as the energy conversion system of light water reactors with high output power like the N4 PWR and the EPR. ARABELLE turbines cumulate 200.000 hours of service with a reliability ratio of 99.97 per cent. This series of slides presents the main features of the turbine including: the use of the simple flux, the very large shape of low pressure blades, the technology of welded rotors. The other main equipment like the alternator, the condenser, the moisture separator-reheaters, the circulating pumps that Alstom integrates in the energy conversion system have benefited with technological improvements that are also presented. (A.C.)

Progress on PEP-II magnet power conversion system

International Nuclear Information System (INIS)

Bellomo, P.; Genova, L.; Jackson, T.; Shimer, D.

1996-01-01

The various power systems for supplying the PEP-II DC magnets rely exclusively on switchmode conversion, utilizing a variety of means depending on the requirements. All of the larger power supplies, ranging from 10 to 200 kW, are powered from DC sources utilizing rectified 480 V AC. Choppers can be used for the series connected strings, but for smaller groups and individual magnets, inverters driving high-frequency transformers with rectifiers comprise the best approach. All of the various systems use a ''building block'' approach of multiple standard-size units connected in series or parallel to most cost-effectively deal with a great range of voltage and current requirements. Utilization of existing infrastructure from PEP-I has been a cost-effective determinant. Equipment is being purchased either off-the-shelf, through performance specification, or by hardware purchase based on design-through-prototype. The corrector magnet power system, utilizing inexpensive, off-the-shelf, four-quadrant switching motor-controllers, has already proven very reliable: 120 of the total of 900 units have been running on the injection system for four months with no failures

Progress on PEP-II magnet power conversion system

Energy Technology Data Exchange (ETDEWEB)

Bellomo, P.; Genova, L. [Stanford Linear Accelerator Center, Menlo Park, CA (United States); Jackson, T. [Lawrence Berkeley National Lab., CA (United States); Shimer, D. [Lawrence Livermore National Lab., CA (United States)

1996-06-04

The various power systems for supplying the PEP-II DC magnets rely exclusively on switchmode conversion, utilizing a variety of means depending on the requirements. All of the larger power supplies, ranging from 10 to 200 kW, are powered from DC sources utilizing rectified 480 V AC. Choppers can be used for the series connected strings, but for smaller groups and individual magnets, inverters driving high-frequency transformers with rectifiers comprise the best approach. All of the various systems use a ``building block`` approach of multiple standard-size units connected in series or parallel to most cost-effectively deal with a great range of voltage and current requirements. Utilization of existing infrastructure from PEP-I has been a cost-effective determinant. Equipment is being purchased either off-the-shelf, through performance specification, or by hardware purchase based on design-through-prototype. The corrector magnet power system, utilizing inexpensive, off-the-shelf, four-quadrant switching motor-controllers, has already proven very reliable: 120 of the total of 900 units have been running on the injection system for four months with no failures.

Nuclear reactor closed Brayton cycle power conversion system optimization trends for extra-terrestrial applications

International Nuclear Information System (INIS)

Ashe, T.L.; Baggenstoss, W.G.; Bons, R.

1990-01-01

Extra-terrestrial exploration and development missions of the next century will require reliable, low-mass power generation modules of 100 kW e and more. These modules will be required to support both fixed-base and manned rover/explorer power needs. Low insolation levels at and beyond Mars and long periods of darkness on the moon make solar conversion less desirable for surface missions. For these missions, a closed Brayton cycle energy conversion system coupled with a reactor heat source is a very attractive approach. The authors conducted parametric studies to assess optimized system design trends for nuclear-Brayton systems as a function of operating environment and user requirements. The inherent design flexibility of the closed Brayton cycle energy conversion system permits ready adaptation of the system to future design constraints. This paper describes a dramatic contrast between system designs requiring man-rated shielding. The paper also considers the ramification of using indigenous materials to provide reactor shielding for a fixed-base power source

Heat Pipe Powered Stirling Conversion for the Demonstration Using Flattop Fission (DUFF) Test

Science.gov (United States)

Gibson, Marc A.; Briggs, Maxwell H.; Sanzi, James L.; Brace, Michael H.

2013-01-01

Design concepts for small Fission Power Systems (FPS) have shown that heat pipe cooled reactors provide a passive, redundant, and lower mass option to transfer heat from the fuel to the power conversion system, as opposed to pumped loop designs typically associated with larger FPS. Although many systems have been conceptually designed and a few making it to electrically heated testing, none have been coupled to a real nuclear reactor. A demonstration test named DUFF Demonstration Using Flattop Fission, was planned by the Los Alamos National Lab (LANL) to use an existing criticality experiment named Flattop to provide the nuclear heat source. A team from the NASA Glenn Research Center designed, built, and tested a heat pipe and power conversion system to couple to Flattop with the end goal of making electrical power. This paper will focus on the design and testing performed in preparation for the DUFF test.

Development of water demand coefficients for power generation from renewable energy technologies

International Nuclear Information System (INIS)

Ali, Babkir; Kumar, Amit

2017-01-01

Highlights: • Water consumption and withdrawals coefficients for renewable power generation were developed. • Six renewable energy sources (biomass, nuclear, solar, wind, hydroelectricity, and geothermal) were studied. • Life cycle water footprints for 60 electricity generation pathways were considered. • Impact of cooling systems for some power generation pathways was assessed. - Abstract: Renewable energy technology-based power generation is considered to be environmentally friendly and to have a low life cycle greenhouse gas emissions footprint. However, the life cycle water footprint of renewable energy technology-based power generation needs to be assessed. The objective of this study is to develop life cycle water footprints for renewable energy technology-based power generation pathways. Water demand is evaluated through consumption and withdrawals coefficients developed in this study. Sixty renewable energy technology-based power generation pathways were developed for a comprehensive comparative assessment of water footprints. The pathways were based on the use of biomass, nuclear, solar, wind, hydroelectricity, and geothermal as the source of energy. During the complete life cycle, power generation from bio-oil extracted from wood chips, a biomass source, was found to have the highest water demand footprint and wind power the lowest. During the complete life cycle, the water demand coefficients for biomass-based power generation pathways range from 260 to 1289 l of water per kilowatt hour and for nuclear energy pathways from 0.48 to 179 l of water per kilowatt hour. The water demand for power generation from solar energy-based pathways ranges from 0.02 to 4.39 l of water per kilowatt hour, for geothermal pathways from 0.04 to 1.94 l of water per kilowatt hour, and for wind from 0.005 to 0.104 l of water per kilowatt hour. A sensitivity analysis was conducted with varying conversion efficiencies to evaluate the impact of power plant performance on

Design and cost of near-term OTEC (Ocean Thermal Energy Conversion) plants for the production of desalinated water and electric power. [Ocean Thermal Energy Conversion (OTEC)

Energy Technology Data Exchange (ETDEWEB)

Rabas, T.; Panchal, C.; Genens, L.

1990-01-01

There currently is an increasing need for both potable water and power for many islands in the Pacific and Caribbean. The Ocean Thermal Energy Conversion (OTEC) technology fills these needs and is a viable option because of the unlimited supply of ocean thermal energy for the production of both desalinated water and electricity. The OTEC plant design must be flexible to meet the product-mix demands that can be very different from site to site. This paper describes different OTEC plants that can supply various mixes of desalinated water and vapor -- the extremes being either all water and no power or no water and all power. The economics for these plants are also presented. The same flow rates and pipe sizes for both the warm and cold seawater streams are used for different plant designs. The OTEC plant designs are characterized as near-term because no major technical issues need to be resolved or demonstrated. The plant concepts are based on DOE-sponsored experiments dealing with power systems, advanced heat exchanger designs, corrosion and fouling of heat exchange surfaces, and flash evaporation and moisture removal from the vapor using multiple spouts. In addition, the mature multistage flash evaporator technology is incorporated into the plant designs were appropriate. For the supply and discharge warm and cold uncertainties do exist because the required pipe sizes are larger than the maximum currently deployed -- 40-inch high-density polyethylene pipe at Keahole Point in Hawaii. 30 refs., 6 figs., 8 tabs.

Power conversion unit for the South African direct cycle HTGR

International Nuclear Information System (INIS)

Liebenberg, J.J.

1997-01-01

The system parameters chosen to optimise the thermal efficiency of the Eskom PBMR whilst maintaining component simplicity is discussed. Power Conversion Unit components, which are now at a preliminary design stage comprise a precooler, two turbo units consisting of a turbine driven compressor, recuperator and a power turbine, driving an alternator. Design aspects of every component is mentioned and the inventory method of poorer control is explained with reference to start-up and and shut-down events, the system an effective load following device, down to 4% of full power. Application of the same design principles for HTGRs smaller than 25 MWe is discussed. (author)

Toward High-Power Klystrons With RF Power Conversion Efficiency on the Order of 90%

CERN Document Server

Baikov, Andrey Yu; Syratchev, Igor

2015-01-01

The increase in efficiency of RF power generation for future large accelerators is considered a high priority issue. The vast majority of the existing commercial high-power RF klystrons operates in the electronic efficiency range between 40% and 55%. Only a few klystrons available on the market are capable of operating with 65% efficiency or above. In this paper, a new method to achieve 90% RF power conversion efficiency in a klystron amplifier is presented. The essential part of this method is a new bunching technique - bunching with bunch core oscillations. Computer simulations confirm that the RF production efficiency above 90% can be reached with this new bunching method. The results of a preliminary study of an L-band, 20-MW peak RF power multibeam klystron for Compact Linear Collider with the efficiency above 85% are presented.

Power beaming providing a space power infrastructure

International Nuclear Information System (INIS)

Bamberger, J.A.; Coomes, E.P.

1992-01-01

This paper, based on two levels of technology maturity, applied the power beaming concept to four panned satellite constellations. The analysis shows that with currently available technology, power beaming can provide mass savings to constellations in orbits ranging from low-Earth orbit to geosynchronous orbit. Two constellations, space surveillance and tracking system and space-based radar, can be supported with current technology. The other two constellations, space-based laser array and boost surveillance and tracking system, will require power and transmission system improvements before their breakeven specific mass is achieved. A doubling of SP-100 conversion efficiency from 10 to 20% would meet or exceed breakeven for these constellations

Conceptual design of the blanket and power conversion system for a mirror hybrid fusion-fission reactor. 12-month progress report, July 1, 1975--June 30, 1976

International Nuclear Information System (INIS)

Schultz, K.R.; Baxi, C.B.; Rao, R.

1976-01-01

This report presents the conceptual design and preliminary feasibility assessment for the hybrid blanket and power conversion system of the Mirror Hybrid Fusion-Fission Reactor. Existing gas-cooled fission reactor technology is directly applicable to the Mirror Hybrid Reactor. There are a number of aspects of the present conceptual design that require further design and analysis effort. The blanket and power conversion system operating parameters have not been optimized. The method of supporting the blanket modules and the interface between these modules and the primary loop helium ducting will require further design work. The means of support and containment of the primary loop components must be studied. Nevertheless, in general, the conceptual design appears quite feasible

Thermochemical conversion of microalgal biomass into biofuels: a review.

Science.gov (United States)

Chen, Wei-Hsin; Lin, Bo-Jhih; Huang, Ming-Yueh; Chang, Jo-Shu

2015-05-01

Following first-generation and second-generation biofuels produced from food and non-food crops, respectively, algal biomass has become an important feedstock for the production of third-generation biofuels. Microalgal biomass is characterized by rapid growth and high carbon fixing efficiency when they grow. On account of potential of mass production and greenhouse gas uptake, microalgae are promising feedstocks for biofuels development. Thermochemical conversion is an effective process for biofuel production from biomass. The technology mainly includes torrefaction, liquefaction, pyrolysis, and gasification. Through these conversion technologies, solid, liquid, and gaseous biofuels are produced from microalgae for heat and power generation. The liquid bio-oils can further be upgraded for chemicals, while the synthesis gas can be synthesized into liquid fuels. This paper aims to provide a state-of-the-art review of the thermochemical conversion technologies of microalgal biomass into fuels. Detailed conversion processes and their outcome are also addressed. Copyright © 2014 Elsevier Ltd. All rights reserved.

Development of nuclear technologies and conversion of nuclear weapon testing system infrastructure in Kazakhstan

International Nuclear Information System (INIS)

Cherepnin, Yu.; Takibaev, Zh.

2000-01-01

The article gives a brief description of the work done by the National Nuclear Center of the Republic of Kazakhstan in development of nuclear technology and conversion of nuclear weapon testing infrastructure in Kazakhstan. Content and trends of works are as follows: 1. Peaceful use of all physical facilities, created earlier for nuclear tests in Kazakhstan; 2. Development of methods and technologies for safe nuclear reactors use; 3. Examination of different materials in field of great neutron flow for thermonuclear reactor's first wall development; 4. Liquidation of all wells, which were formed in the results of underground nuclear explosions in Degelen mountain massif of former Semipalatinsk test site; 5. Study of consequences of nuclear tests in West Kazakhstan (territory of Azgir test site and Karachaganak oil field); 6. Study of radiological situation on the Semipalatinsk test site and surrounding territories; 7. Search of ways for high-level radioactive wastes disposal; 8. Construction of safe nuclear power plants in Kazakhstan

Lunar electric power systems utilizing the SP-100 reactor coupled to dynamic conversion systems. Final report

International Nuclear Information System (INIS)

Harty, R.B.; Durand, R.E.

1993-03-01

An integration study was performed by Rocketdyne under contract to NASA-LeRC. The study was concerned with coupling an SP-0100 reactor to either a Brayton or Stirling power conversion system. The application was for a surface power system to supply power requirements to a lunar base. A power level of 550 kWe was selected based on the NASA Space Exploration Initiative 90-day study. Reliability studies were initially performed to determine optimum power conversion redundancy. This study resulted in selecting three operating engines and one stand-by unit. Integration design studies indicated that either the Brayton or Stirling power conversion systems could be integrated with the PS-100 reactor. The Stirling system had an integration advantage because of smaller piping size and fewer components. The Stirling engine, however, is more complex and heavier than the Brayton rotating unit, which tends to off-set the Stirling integration advantage. From a performance consideration, the Brayton had a 9 percent mass advantage, and the Stirling had a 50 percent radiator advantage

Experimental Investigations from the Operation of a 2 Kw Brayton Power Conversion Unit and a Xenon Ion Thruster

Science.gov (United States)

Mason, Lee; Birchenough, Arthur; Pinero, Luis

2004-01-01

A 2 kW Brayton Power Conversion Unit (PCU) and a xenon ion thruster were integrated with a Power Management and Distribution (PMAD) system as part of a Nuclear Electric Propulsion (NEP) Testbed at NASA's Glenn Research Center. Brayton converters and ion thrusters are potential candidates for use on future high power NEP missions such as the proposed Jupiter Icy Moons Orbiter (JIMO). The use of existing lower power test hardware provided a cost-effective means to investigate the critical electrical interface between the power conversion system and ion propulsion system. The testing successfully demonstrated compatible electrical operations between the converter and the thruster, including end-to-end electric power throughput, high efficiency AC to DC conversion, and thruster recycle fault protection. The details of this demonstration are reported herein.

Frontiers of Energy Storage and Conversion

Directory of Open Access Journals (Sweden)

Jiajun Chen

2014-09-01

Full Text Available This special issue of Inorganics features a Forum for novel materials and approaches for electrochemical energy storage and conversion. Diminishing non-renewable fossil fuels and the resulting unattainability of environment have made us search new sustainable energy resources and develop technology for efficient utilization of such resources. Green energy sources, such as solar, hydroelectric, thermal and wind energy are partially replacing fossil fuels as means to generate power. Inorganic (solid state materials are key in the development of advanced devices for the efficient storage and conversion of energy. The grand challenge facing the inorganic chemist is to discover, design rationally and utilize advanced technological materials made from earth-abound elements for these energy storage and conversion processes. Recent spectacular progress in inorganic materials synthesis, characterization, and computational screening has greatly advanced this field, which drove us to edit this issue to provide a window to view the development of this field for the community. This special issue comprises research articles, which highlights some of the most recent advances in new materials for energy storage and conversion. [...

The future of electronic power processing and conversion

DEFF Research Database (Denmark)

Blaabjerg, Frede; Consoli, A.; Ferreira, J.A.

2005-01-01

. - A large penetration of power electronics into power systems will happen within the next 25-30 years. The main transmission grid will not be affected. The power electronics development will be in distributed generation and in the loads. - The success of the integrated starter/generator, hybrid or electric...... cars depends on political decisions more than on technological advances. However, the success of a recent Japanese hybrid car and the cost of oil could trigger the critical momentum for large-scale use of power electronics in automotive applications. - We are moving toward standardized power supply...

The geothermal power organization

Energy Technology Data Exchange (ETDEWEB)

Scholl, K.L. [National Renewable Energy Lab., Golden, CO (United States)

1997-12-31

The Geothermal Power Organization is an industry-led advisory group organized to advance the state-of-the-art in geothermal energy conversion technologies. Its goal is to generate electricity from geothermal fluids in the most cost-effective, safe, and environmentally benign manner possible. The group achieves this goal by determining the Member`s interest in potential solutions to technological problems, advising the research and development community of the needs of the geothermal energy conversion industry, and communicating research and development results among its Members. With the creation and adoption of a new charter, the Geothermal Power Organization will now assist the industry in pursuing cost-shared research and development projects with the DOE`s Office of Geothermal Technologies.

Overview of Multi-Kilowatt Free-Piston Stirling Power Conversion Research at Glenn Research Center

Science.gov (United States)

Geng, Steven M.; Mason, Lee S.; Dyson, Rodger W.; Penswick, L. Barry

2008-01-01

As a step towards development of Stirling power conversion for potential use in Fission Surface Power (FSP) systems, a pair of commercially available 1 kW class free-piston Stirling convertors and a pair of commercially available pressure wave generators (which will be plumbed together to create a high power Stirling linear alternator test rig) have been procured for in-house testing at Glenn Research Center (GRC). Delivery of both the Stirling convertors and the linear alternator test rig is expected by October 2007. The 1 kW class free-piston Stirling convertors will be tested at GRC to map and verify performance. The convertors will later be modified to operate with a NaK liquid metal pumped loop for thermal energy input. The high power linear alternator test rig will be used to map and verify high power Stirling linear alternator performance and to develop power management and distribution (PMAD) methods and techniques. This paper provides an overview of the multi-kilowatt free-piston Stirling power conversion work being performed at GRC.

TECHNOLOGICAL AND ENVIRONMENTAL PROBLEMS CONNECTED WITH THERMAL CONVERSION OF SEWAGE SLUDGE

Directory of Open Access Journals (Sweden)

Alina Żogała

2016-02-01

Full Text Available Overview of the most common technological and environmental problems connected with thermal conversion of sewage sludge was presented in the article. Such issues as the influence of content of moisture and mineral matter on fuel properties of sludge, problem of emission of pollutants, problem of management of solid residue, risk of corrosion, were described. Besides, consolidated characteristic of the most important methods of thermal conversion of sewage sludge, with their advantages and disadvantages, was presented in the paper.

Design and Test Plans for a Non-Nuclear Fission Power System Technology Demonstration Unit

Science.gov (United States)

Mason, Lee; Palac, Donald; Gibson, Marc; Houts, Michael; Warren, John; Werner, James; Poston, David; Qualls, Arthur Lou; Radel, Ross; Harlow, Scott

2012-01-01

A joint National Aeronautics and Space Administration (NASA) and Department of Energy (DOE) team is developing concepts and technologies for affordable nuclear Fission Power Systems (FPSs) to support future exploration missions. A key deliverable is the Technology Demonstration Unit (TDU). The TDU will assemble the major elements of a notional FPS with a non-nuclear reactor simulator (Rx Sim) and demonstrate system-level performance in thermal vacuum. The Rx Sim includes an electrical resistance heat source and a liquid metal heat transport loop that simulates the reactor thermal interface and expected dynamic response. A power conversion unit (PCU) generates electric power utilizing the liquid metal heat source and rejects waste heat to a heat rejection system (HRS). The HRS includes a pumped water heat removal loop coupled to radiator panels suspended in the thermal-vacuum facility. The basic test plan is to subject the system to realistic operating conditions and gather data to evaluate performance sensitivity, control stability, and response characteristics. Upon completion of the testing, the technology is expected to satisfy the requirements for Technology Readiness Level 6 (System Demonstration in an Operational and Relevant Environment) based on the use of high-fidelity hardware and prototypic software tested under realistic conditions and correlated with analytical predictions.

WIND ENERGY CONVERSION SYSTEMS - A TECHNICAL REVIEW

Directory of Open Access Journals (Sweden)

N. RAMESH BABU

2013-08-01

Full Text Available Wind power production has been under the main focus for the past decade in power production and tremendous amount of research work is going on renewable energy, specifically on wind power extraction. Wind power provides an eco-friendly power generation and helps to meet the national energy demand when there is a diminishing trend in terms of non-renewable resources. This paper reviews the modeling of Wind Energy Conversion Systems (WECS, control strategies of controllers and various Maximum Power Point Tracking (MPPT technologies that are being proposed for efficient production of wind energy from the available resource.

HYLIFE-II power conversion system design and cost study

International Nuclear Information System (INIS)

Hoffman, M.A.

1990-09-01

The power conversion system for the HYLIFE-2 fusion power plant has been defined to include the IHX's (intermediate heat exchangers) and everything that support the exchange of energy from the reactor. It is referred to simply as the BOP (balance of plant) in the rest of this report. The above is a convenient division between the reactor equipment and the rest of the fusion power plant since the BOP design and cost then depend only on the specification of the thermal power to the IHX's and the temperature of the primary Flibe coolant into and out of the IHX's, and is almost independent of the details of the reactor design. The main efforts during the first year have been on the definition and thermal-hydraulics of the IHX's, the steam generators and the steam power plant, leading to the definition of a reference BOP with the molten salt, Flibe, as the primary coolant. A summary of the key results in each of these areas is given in this report

9.0% power conversion efficiency from ternary all-polymer solar cells

NARCIS (Netherlands)

Li, Z.; Xu, X.; Zhang, W.; Meng, X.; Genene, Z.; Ma, W.; Mammo, W.; Yartsev, A.; Andersson, M.; Janssen, R.A.J.; Wang, E.

2017-01-01

Integration of a third component into a single-junction polymer solar cell (PSC) is regarded as an attractive strategy to enhance the performance of PSCs. Although binary all-polymer solar cells (all-PSCs) have recently emerged with compelling power conversion efficiencies (PCEs), the PCEs of

Conversational flow promotes solidarity.

Science.gov (United States)

Koudenburg, Namkje; Postmes, Tom; Gordijn, Ernestine H

2013-01-01

Social interaction is fundamental to the development of various aspects of "we-ness". Previous research has focused on the role the content of interaction plays in establishing feelings of unity, belongingness and shared reality (a cluster of variables referred to as solidarity here). The present paper is less concerned with content, but focuses on the form of social interaction. We propose that the degree to which conversations flow smoothly or not is, of itself, a cue to solidarity. We test this hypothesis in samples of unacquainted and acquainted dyads who communicate via headsets. Conversational flow is disrupted by introducing a delay in the auditory feedback (vs. no delay). Results of three studies show that smoothly coordinated conversations (compared with disrupted conversations and a control condition) increase feelings of belonging and perceptions of group entitativity, independently of conversation content. These effects are driven by the subjective experience of conversational flow. Our data suggest that this process occurs largely beyond individuals' control. We conclude that the form of social interaction is a powerful cue for inferring group solidarity. Implications for the impact of modern communication technology on developing a shared social identity are discussed.

Conversational flow promotes solidarity.

Directory of Open Access Journals (Sweden)

Namkje Koudenburg

Full Text Available Social interaction is fundamental to the development of various aspects of "we-ness". Previous research has focused on the role the content of interaction plays in establishing feelings of unity, belongingness and shared reality (a cluster of variables referred to as solidarity here. The present paper is less concerned with content, but focuses on the form of social interaction. We propose that the degree to which conversations flow smoothly or not is, of itself, a cue to solidarity. We test this hypothesis in samples of unacquainted and acquainted dyads who communicate via headsets. Conversational flow is disrupted by introducing a delay in the auditory feedback (vs. no delay. Results of three studies show that smoothly coordinated conversations (compared with disrupted conversations and a control condition increase feelings of belonging and perceptions of group entitativity, independently of conversation content. These effects are driven by the subjective experience of conversational flow. Our data suggest that this process occurs largely beyond individuals' control. We conclude that the form of social interaction is a powerful cue for inferring group solidarity. Implications for the impact of modern communication technology on developing a shared social identity are discussed.

High-Efficiency, Nanowire Based Thermoelectric Devices for Radioisotope Power Conversion, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — This SBIR Phase I proposal responds to topic S3.03 of the 2010 NASA SBIR solicitation, for Power Generation and Conversion. Thermoelectric devices offer a simple and...

Complete biocycle for solar energy conversion, storage, fuel and power generation, and coal conservation for future use

International Nuclear Information System (INIS)

Srivastava, S.C.

1993-01-01

A complete carbon biocycle has been described, starting from coal in in situ condition in coal seams underground. Various steps involved are: (i) Biogasification of coal to methane, using a consortia of bacteria, has been reported. A group of bacteria degrades complex structure of coal to simpler structure. This simpler structure of coal, is then converted to methane by methanogens; (ii) Biophotolysis of methane and associated biodegradation, results in products, such as hydrogen and oxygen for use in fuel cells for power generation; (iii) Bioconversion of products so obtained is carried out to produce methanol or methane that could be used as fuel or recycled; (iv) In complete biocycle some methane is converted to biomass. In order to replace this methane, coal is converted to methane using group of bacteria, only to the extent methane has been converted to biomass; (v) The biomass so produced could be dumped underground from where coal has been gasified. Alternatively it could be burnt as fuel or else used as substitute of protein in animal food. Detailed concept of proposed technology for: (a) an alternative to conventional coal mining, (b) generation of power using products of bioconversion in fuel cell, and (c) conversation of solar energy for generation of alternative source of fuel and power, has been discussed. Possibility of developing a biofuel cell for conversion of solar energy through bioelectrochemical route has been suggested. (author). 48 refs., 3 figs

Design study on evaluation for power conversion system concepts in high temperature gas cooled reactor with gas turbine

International Nuclear Information System (INIS)

Minatsuki, Isao; Mizokami, Yorikata

2007-01-01

The design studies on High Temperature Gas Cooled Reactor with Gas Turbine (HTGR-GT) have been performed, which were mainly promoted by Japan Atomic Energy Agency (JAEA) and supported by fabricators in Japan. HTGR-GT plant feature is almost determined by selection of power conversion system concepts. Therefore, plant design philosophy is observed characteristically in selection of them. This paper describes the evaluation and analysis of the essential concepts of the HTGR-GT power conversion system through the investigations based on our experiences and engineering knowledge as a fabricator. As a result, the following concepts were evaluated that have advantages against other competitive one, such as the horizontal turbo machine rotor, the turbo machine in an individual vessel, the turbo machine with single shaft, the generator inside the power conversion vessel, and the power conversion system cycle with an intercooler. The results of the study can contribute as reference data when the concepts will be selected. Furthermore, we addressed reasonableness about the concept selection of the Gas Turbine High Temperature Reactor GTHTR300 power conversion system, which has been promoted by JAEA. As a conclusion, we recognized the GTHTR300 would be one of the most promising concepts for commercialization in near future. (author)

Research on novel coal conversion technology for energy and environment in 21st century

Energy Technology Data Exchange (ETDEWEB)

T. Takarada [Gunma University (Japan)

2003-07-01

In the 21st century, more efficient coal conversion technology will be needed. In this paper, novel gasification, pyrolysis and desulfurization processes using active catalysts are introduced. In particular, the application of ion-exchanged metals in brown coal to coal conversion technology is featured in this study. Other topics discussed include: Catalysis of mineral matter in coal; Catalytic effectiveness of Ni and K{sub 2}CO{sub 3} for various coals; Direct production of methane from steam gasification; Preparation of active catalysts from NaCl and KCl using brown coal; Gasification of high rank coal by mixing K-exchanged brown coal; Recovery of sulfur via catalytic SO{sub 2} gasification of coal char; Research on novel coal conversion technology BTX production by hydropyrolysis of coal in PPFB using catalyst; High BTU gas production by low-temperature catalytic hydropyrolysis of coal; and Ca-exchanged brown coal as SO{sub 2} and H{sub 2}S sorbents. 12 refs., 17 figs.

Fiscal 2000 report on the development of high-efficiency refuse-fueled power generation technology; Kokoritsu haikibutsu hatsuden gijutsu kaihatsu 2000 nendo hokokusho

Energy Technology Data Exchange (ETDEWEB)

NONE

2001-03-01

Efforts were made to develop a refuse gasification/fusion power generation technology to contribute to the effective utilization of unexploited energy and to reduction in greenhouse gas emissions. Developed in the technology of elevating steam temperature were the evaluation of high-temperature corrosion of SH materials and a high temperature dust removing system, dechlorination technology for the thermolysis process, and a ceramic-made high-temperature air heater. For the avoidance of exhaust gas reheating, development was carried out for a low-temperature denitration unit, stable refuse feeding system for reduction in the self-heat melting critical calorific value, waste plastic injection technology for reduction in the amount of external fuel injection, and so forth. The effect of the developed element technologies were evaluated and a detailed feasibility study was conducted for a refuse gas conversion power generation system using gas engine power generation for minor-scale general waste treatment facilities. In the survey of the trend of refuse-fueled power generation technologies, trend in Japan and advanced refuse-fueled power generation systems and their introduction in Europe and America were investigated. (NEDO)

Coherence-limited solar power conversion: the fundamental thermodynamic bounds and the consequences for solar rectennas

Science.gov (United States)

Mashaal, Heylal; Gordon, Jeffrey M.

2014-10-01

Solar rectifying antennas constitute a distinct solar power conversion paradigm where sunlight's spatial coherence is a basic constraining factor. In this presentation, we derive the fundamental thermodynamic limit for coherence-limited blackbody (principally solar) power conversion. Our results represent a natural extension of the eponymous Landsberg limit, originally derived for converters that are not constrained by the radiation's coherence, and are irradiated at maximum concentration (i.e., with a view factor of unity to the solar disk). We proceed by first expanding Landsberg's results to arbitrary solar view factor (i.e., arbitrary concentration and/or angular confinement), and then demonstrate how the results are modified when the converter can only process coherent radiation. The results are independent of the specific power conversion mechanism, and hence are valid for diffraction-limited as well as quantum converters (and not just classical heat engines or in the geometric optics regime). The derived upper bounds bode favorably for the potential of rectifying antennas as potentially high-efficiency solar converters.

Potential Impacts of Hydrokinetic and Wave Energy Conversion Technologies on Aquatic Environments

Energy Technology Data Exchange (ETDEWEB)

Čada, Glenn F.

2007-04-01

A new generation of hydropower technologies, the kinetic hydro and wave energy conversion devices, offers the possibility of generating electricity from the movements of water, without the need for dams and diversions. The Energy Policy Act of 2005 encouraged the development of these sources of renewable energy in the United States, and there is growing interest in deploying them globally. The technologies that would extract electricity from free-flowing streams, estuaries, and oceans have not been widely tested. Consequently, the U.S. Department of Energy convened a workshop to (1) identify the varieties of hydrokinetic energy and wave energy conversion devices and their stages of development, (2) identify where these technologies can best operate, (3) identify the potential environmental issues associated with these technologies and possible mitigation measures, and (4) develop a list of research needs and/or practical solutions to address unresolved environmental issues. The article reviews the results of that workshop, focusing on potential effects on freshwater, estuarine, and marine ecosystems, and we describe recent national and international developments.

FY 2000 report on the results of the survey on the biomass-derived energy conversion technology. III; 2000 nendo biomass shigen wo genryo to suru energy henkan gijutsu ni kansuru chosa. 3

Energy Technology Data Exchange (ETDEWEB)

NONE

2001-03-01

In relation to the biomass-derived energy conversion technology which was regarded as promising from the results of the survey already made, the survey was made on the present situation and subjects of the technical development, social needs, energy efficiency, economical efficiency and the future. Studies were conducted on the development of technology for effective biomass utilization and the conceptual design and evaluation of a system for effective biomass utilization. As to the effective biomass utilization technology, the survey was made on the biomass combustion power generation technology/gasification power generation technology, gasification methanol synthesis of biomass, biomass gasification dimethyl ether synthesis, technology of ethanol production by alcohol fermentation via saccharification of biomass, methy-esterification of grease biomass, especially palm oil, and diesel oil production via reformation of by-product glycerin, and energy production from biomass using super- (sub- ) critical reaction. As to the system for effective biomass utilization, the survey was carried out of the regional outline, resource amount and sampling amount, selection of the conversion technology, and economical efficiency of Takatsuki city, Osaka, Shimokawa town, Hokkaido, Yufutsu/Hidaka region, Hokkaido, and Aogaki town, Hyogo. (NEDO)

Limits to power system growth

International Nuclear Information System (INIS)

Slater, S.M.; Klein, A.C.; Webb, B.J.; Pauley, K.A.

1993-01-01

In the design of space nuclear power systems a variety of conversion techniques may be used, each with its own advantages and disadvantages. A study was performed which analyzed over 120 proposed system designs. The designs were compared to identify the optimum conversion system as a function of power level and find limits to specific mass (kg/kWe) for each power cycle. Furthermore, the component masses were studied to determine which component of the overall design contributes the most to total system mass over a variety of power levels. The results can provide a focus for future research efforts by selecting the best conversion technology for the desired power range, and optimizing the system component which contributes most to the total mass

Experimental Investigation from the Operation of a 2 kW Brayton Power Conversion Unit and a Xenon Ion Thruster

Science.gov (United States)

Hervol, David; Mason, Lee; Birchenough, Art; Pinero, Luis

2004-01-01

A 2kW Brayton Power Conversion Unit (PCU) and a xenon ion thruster were integrated with a Power Management and Distribution (PMAD) system as part of a Nuclear Electric Propulsion (NEP) Testbed at NASA's Glenn Research Center. Brayton Converters and ion thrusters are potential candidates for use on future high power NEP mission such as the proposed Jupiter Icy Moons Orbiter (JIMO). The use of a existing lower power test hardware provided a cost effective means to investigate the critical electrical interface between the power conversion system and the propulsion system. The testing successfully demonstrated compatible electrical operations between the converter and the thruster, including end-to-end electric power throughput, high efficiency AC to DC conversion, and thruster recycle fault protection. The details of this demonstration are reported herein.

Dimensionless Energy Conversion Characteristics of an Air-Powered Hydraulic Vehicle

Directory of Open Access Journals (Sweden)

Dongkai Shen

2018-02-01

Full Text Available Due to the advantages of resource conservation and less exhaust emissions, compressed air-powered vehicle has attracted more and more attention. To improve the power and efficiency of air-powered vehicle, an air-powered hydraulic vehicle was proposed. As the main part of the air-powered hydraulic vehicles, HP transformer (short for Hydropneumatic transformer is used to convert the pneumatic power to higher hydraulic power. In this study, to illustrate the energy conversion characteristics of air-powered hydraulic vehicle, dimensionless mathematical model of the vehicle’s working process was set up. Through experimental study on the vehicle, the dimensionless model was verified. Through simulation study on the vehicle, the following can be obtained: firstly, the increase of the hydraulic chamber orifice and the area ratio of the pistons can lead to a higher output power, while output pressure is just the opposite. Moreover, the increase of the output pressure and the aperture of the hydraulic chamber can lead to a higher efficiency, while area ratio of the pistons played the opposite role. This research can be referred to in the performance and design optimization of the HP transformers.

Development of sensor-less control strategies for grid connected PMSG based variable speed wind energy conversion system with improved power quality features

Energy Technology Data Exchange (ETDEWEB)

Chandra, A. [Quebec Univ., Montreal, PQ (Canada). Dept. of Electrical Engineering

2010-07-01

Interest in renewable energy sources has grown in recent years in response to concerns of increasing pollution levels and depleting fossil fuels. Among renewable energy sources, wind energy generation is the fastest growing technology and one of the most cost-effective and environmental friendly means to generate electricity from renewable sources. Modern wind turbines are ready to be deployed in large scale as a result of recent developments in wind power technology. Variable speed permanent magnet synchronous generators (PMSG) based wind energy conversion systems (WECS) are becoming more popular. The use of a permanent magnet reduces size, cost and weight of overall WECS. In addition, the absence of field winding and its excitation system avoids heat dissipation in the rotor winding, thereby improving overall efficiency of the WECS. This type of configuration is more appropriate for remote locations, particularly for off-shore wind application, where the geared doubly fed induction generator usually requires regular maintenance due to tearing-wearing in brushes, windings and gear box. This presentation discussed the development of sensor-less control strategies for grid connected PMSG based variable speed wind energy conversion system with improved power quality features. A novel adaptive network-based fuzzy inference system was used to estimate the speed and position of variable speed PMSG under fluctuating wind conditions. A novel control strategy was developed for the grid interfacing inverter incorporating power quality improvement features at point of common coupling.

Closed Brayton Cycle Power Conversion Unit for Fission Surface Power Phase I Final Report

Science.gov (United States)

Fuller, Robert L.

2010-01-01

A Closed Brayton cycle power conversion system has been developed to support the NASA fission surface power program. The goal is to provide electricity from a small nuclear reactor heat source for surface power production for lunar and Mars environments. The selected media for a heat source is NaK 78 with water as a cooling source. The closed Brayton cycle power was selected to be 12 kWe output from the generator terminals. A heat source NaK temperature of 850 K plus or minus 25 K was selected. The cold source water was selected at 375 K plus or minus 25 K. A vacuum radiation environment of 200 K is specified for environmental operation. The major components of the system are the power converter, the power controller, and the top level data acquisition and control unit. The power converter with associated sensors resides in the vacuum radiation environment. The power controller and data acquisition system reside in an ambient laboratory environment. Signals and power are supplied across the pressure boundary electrically with hermetic connectors installed on the vacuum vessel. System level analyses were performed on working fluids, cycle design parameters, heater and cooling temperatures, and heat exchanger options that best meet the needs of the power converter specification. The goal is to provide a cost effective system that has high thermal-to-electric efficiency in a compact, lightweight package.

An Overview of Power, Energy Storage, and Conversion Efforts for 2014 SBIR Phases I and II

Science.gov (United States)

Nguyen, Hung D.; Steele, Gynelle C.

2016-01-01

Technological innovation is the overall focus of NASA's Small Business Innovation Research (SBIR) program. The program invests in the development of innovative concepts and technologies to help NASA's mission directorates address critical research and development needs for agency projects. NASA's Small Business Innovation Research (SBIR) program focuses on technological innovation by investing in development of innovative concepts and technologies to help NASA mission directorates address critical research needs for Agency programs. This report highlights 15 of the innovative SBIR 2014 Phase I and II projects that focus on one of NASA Glenn Research Center's six core competencies-Power, Energy Storage and Conversion. The technologies cover a wide spectrum of applications such as high-radiation-tolerant ceramic voltage isolators, development of hermetic sealing glasses for solid oxide fuel cells, rechargeable lithium metal cells, high-efficiency direct methane solid oxide fuel cell systems, Li metal protection for high-energy space batteries, isolated bidirectional direct current converters for distributed battery energy applications, and high-efficiency rad-hard ultrathin Si photovoltaic cell technology for space. Each article describes an innovation and technical objective and highlights NASA commercial and industrial applications. This report provides an opportunity for NASA engineers, researchers, and program managers to learn how NASA SBIR technologies could help their programs and projects, and lead to collaborations and partnerships between the small SBIR companies and NASA that would benefit both.

Modeling of large aperture third harmonic frequency conversion of high power Nd:glass laser systems

International Nuclear Information System (INIS)

Henesian, M.A.; Wegner, P.J.; Speck, D.R.; Bibeau, C.; Ehrlich, R.B.; Laumann, C.W.; Lawson, J.K.; Weiland, T.L.

1991-01-01

To provide high-energy, high-power beams at short wavelengths for inertial-confinement-fusion experiments, we routinely convert the 1.053-μm output of the Nova, Nd:phosphate-glass, laser system to its third-harmonic wavelength. We describe performance and conversion efficiency modeling of the 3 x 3 arrays potassium-dihydrogen-phosphate crystal plates used for type II/type II phase-matched harmonic conversion of Nova 0.74-m diameter beams, and an alternate type I/type II phase-matching configuration that improves the third-harmonic conversion efficiency. These arrays provide energy conversion of up to 65% and intensity conversion to 70%. 19 refs., 11 figs

High technology supporting nuclear power industry in CRIEPI

International Nuclear Information System (INIS)

Ueda, Nobuyuki

2009-01-01

As a central research institute of electric power industry, Central Research Institute of Electric Power Industry (CRIEPI) has carried out R and D on broad range of topics such as power generation, power transmission, power distribution, power application and energy economics and society, aiming to develop prospective and advanced technologies, fundamental reinforce technologies and next-generation core technologies. To realize low-carbon society to cope with enhancement of global environmental issues, nuclear power is highly recommended as large-scale power with low-carbon emission. At the new start of serial explanation on advanced technologies, R and D on electric power industry was outlined. (T. Tanaka)

Semiconductor nanowires for photovoltaic and photoelectrochemical energy conversion

Energy Technology Data Exchange (ETDEWEB)

Dasgupta, Neil; Yang, Peidong

2013-01-23

Semiconductor nanowires (NW) possess several beneficial properties for efficient conversion of solar energy into electricity and chemical energy. Due to their efficient absorption of light, short distances for minority carriers to travel, high surface-to-volume ratios, and the availability of scalable synthesis methods, they provide a pathway to address the low cost-to-power requirements for wide-scale adaptation of solar energy conversion technologies. Here we highlight recent progress in our group towards implementation of NW components as photovoltaic and photoelectrochemical energy conversion devices. An emphasis is placed on the unique properties of these one-dimensional (1D) structures, which enable the use of abundant, low-cost materials and improved energy conversion efficiency compared to bulk devices.

Power Quality Control and Design of Power Converter for Variable-Speed Wind Energy Conversion System with Permanent-Magnet Synchronous Generator

Directory of Open Access Journals (Sweden)

Yüksel Oğuz

2013-01-01

Full Text Available The control strategy and design of an AC/DC/AC IGBT-PMW power converter for PMSG-based variable-speed wind energy conversion systems (VSWECS operation in grid/load-connected mode are presented. VSWECS consists of a PMSG connected to a AC-DC IGBT-based PWM rectifier and a DC/AC IGBT-based PWM inverter with LCL filter. In VSWECS, AC/DC/AC power converter is employed to convert the variable frequency variable speed generator output to the fixed frequency fixed voltage grid. The DC/AC power conversion has been managed out using adaptive neurofuzzy controlled inverter located at the output of controlled AC/DC IGBT-based PWM rectifier. In this study, the dynamic performance and power quality of the proposed power converter connected to the grid/load by output LCL filter is focused on. Dynamic modeling and control of the VSWECS with the proposed power converter is performed by using MATLAB/Simulink. Simulation results show that the output voltage, power, and frequency of VSWECS reach to desirable operation values in a very short time. In addition, when PMSG based VSWECS works continuously with the 4.5 kHz switching frequency, the THD rate of voltage in the load terminal is 0.00672%.

Power quality control and design of power converter for variable-speed wind energy conversion system with permanent-magnet synchronous generator.

Science.gov (United States)

Oğuz, Yüksel; Güney, İrfan; Çalık, Hüseyin

2013-01-01

The control strategy and design of an AC/DC/AC IGBT-PMW power converter for PMSG-based variable-speed wind energy conversion systems (VSWECS) operation in grid/load-connected mode are presented. VSWECS consists of a PMSG connected to a AC-DC IGBT-based PWM rectifier and a DC/AC IGBT-based PWM inverter with LCL filter. In VSWECS, AC/DC/AC power converter is employed to convert the variable frequency variable speed generator output to the fixed frequency fixed voltage grid. The DC/AC power conversion has been managed out using adaptive neurofuzzy controlled inverter located at the output of controlled AC/DC IGBT-based PWM rectifier. In this study, the dynamic performance and power quality of the proposed power converter connected to the grid/load by output LCL filter is focused on. Dynamic modeling and control of the VSWECS with the proposed power converter is performed by using MATLAB/Simulink. Simulation results show that the output voltage, power, and frequency of VSWECS reach to desirable operation values in a very short time. In addition, when PMSG based VSWECS works continuously with the 4.5 kHz switching frequency, the THD rate of voltage in the load terminal is 0.00672%.

Staged Introduction of Non-power and Power Nuclear Technologies to Newcomer Countries

International Nuclear Information System (INIS)

Uesaka, M.

2016-01-01

Full text: Staged introduction of non-power and power nuclear technologies to new comer countries and related knowledge management are presented. Contribution and benefit of radiation technology to medicine and society are very important before nuclear power plants are introduced. Recently, not only new nuclear power technologies but also compact and high performance accelerators for medicine and industrial/social infrastructure maintenance have been developed and used. Such staged introduction with respect to technology, education and economy contributes to enhancement of PA (Public Acceptance). Organized education, knowledge management and network should be associated. (author

Power plant chemical technology

Energy Technology Data Exchange (ETDEWEB)

NONE

1996-12-01

17 contributions covering topies of fossil fuel combustion, flue gas cleaning, power plant materials, corrosion, water/steam cycle chemistry, monitoring and control were presented at the annual meeting devoted to Power Plant Chemical Technology 1996 at Kolding (Denmark) 4-6 September 1996. (EG)

Irradiation Tests Supporting LEU Conversion of Very High Power Research Reactors in the US

Energy Technology Data Exchange (ETDEWEB)

Woolstenhulme, N. E.; Cole, J. I.; Glagolenko, I.; Holdaway, K. K.; Housley, G. K.; Rabin, B. H.

2016-10-01

The US fuel development team is developing a high density uranium-molybdenum alloy monolithic fuel to enable conversion of five high-power research reactors. Previous irradiation tests have demonstrated promising behavior for this fuel design. A series of future irradiation tests will enable selection of final fuel fabrication process and provide data to qualify the fuel at moderately-high power conditions for use in three of these five reactors. The remaining two reactors, namely the Advanced Test Reactor and High Flux Isotope Reactor, require additional irradiation tests to develop and demonstrate the fuel’s performance with even higher power conditions, complex design features, and other unique conditions. This paper reviews the program’s current irradiation testing plans for these moderately-high irradiation conditions and presents conceptual testing strategies to illustrate how subsequent irradiation tests will build upon this initial data package to enable conversion of these two very-high power research reactors.

Evaluation and Optimization of a Supercritical Carbon Dioxide Power Conversion Cycle for Nuclear Applications

International Nuclear Information System (INIS)

Harvego, Edwin A.; McKellar, Michael G.

2011-01-01

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

Basic policy of maintenance for the power conversion system of the gas turbine high temperature reactor 300 (GTHTR300)

International Nuclear Information System (INIS)

Kosugiyama, Shinichi; Takizuka, Takakazu; Kunitomi, Kazuhiko; Yan, Xing; Katanishi, Shoji; Takada, Shoji

2003-01-01

Basic policy of maintenance was determined for major equipment in the power conversion system of the Gas Turbine High Temperature Reactor 300 (GTHTR300). It was developed based on the current maintenance practice in Light Water Reactors (LWRs), High Temperature Engineering Test Reactor (HTTR) and conventional combined cycle power plants while taking into account of unique design features of GTHTR300. First, potential degradation phenomena in operations were identified and corresponding maintenance approaches were proposed for the equipment. Such degradations encountered typically in LWRs as corrosion, erosion and stress corrosion cracking are unlikely to occur since the working fluid of GTHTR300 is inert helium. Main causes of the degradations are high operating temperature and pressure. The gas turbine, compressor, generator, control valves undergo opening and dismantling maintenance in a suitable time interval. The power conversion vessel, heat exchanger vessel, primary system piping and heat exchanging tubes of precooler are subjected to in-service inspections similar to those done in LWRs. As turbine blades represent the severest material degradation because of their high-temperature and high-stress operating conditions, a lifetime management scheme was suggested for them. The longest interval of open-casing maintenance of the gas turbine is estimated to be six to seven years from technical point of view. Present study is entrusted from the Ministry of Education, Culture, Sports, Science and Technology of Japan. (author)

Korean experiences on nuclear power technology

International Nuclear Information System (INIS)

Kim, H.; Yang, H.

1994-01-01

This paper describes the outstanding performance of the indigenous development program of nuclear power technology such as the design and fabrication of both CANDU and PWR fuel and in the design and construction of nuclear steam supply system in Korea. The success has been accomplished through the successful technology transfer from foreign suppliers and efficient utilization of R and D manpower in the design and engineering of nuclear power projects. In order to implement the technology transfer successfully, the joint design concept has been introduced along with effective on-the-job training and the transfer of design documents and computer codes. Korea's successful development of nuclear power program has resulted in rapid expansion of nuclear power generation capacity in a short time, and the nuclear power has contributed to the national economy through lowering electricity price by about 50 % as well as stabilizing electricity supply in 1980s. The nuclear power is expected to play a key role in the future electricity supply in Korea. Now Korea is under way of taking a step toward advanced nuclear technology. The national electricity system expansion plan includes 18 more units of NPPs to be constructed by the year 2006. In this circumstance, the country has fixed the national long-term nuclear R and D program (lgg2-2001) to enhance the national capability of nuclear technology. This paper also briefly describes future prospects of nuclear technology development program in Korea

Advanced, High Power, Next Scale, Wave Energy Conversion Device

Energy Technology Data Exchange (ETDEWEB)

Mekhiche, Mike [Principal Investigator; Dufera, Hiz [Project Manager; Montagna, Deb [Business Point of Contact

2012-10-29

The project conducted under DOE contract DE‐EE0002649 is defined as the Advanced, High Power, Next Scale, Wave Energy Converter. The overall project is split into a seven‐stage, gated development program. The work conducted under the DOE contract is OPT Stage Gate III work and a portion of Stage Gate IV work of the seven stage product development process. The project effort includes Full Concept Design & Prototype Assembly Testing building on our existing PowerBuoy technology to deliver a device with much increased power delivery. Scaling‐up from 150kW to 500kW power generating capacity required changes in the PowerBuoy design that addressed cost reduction and mass manufacturing by implementing a Design for Manufacturing (DFM) approach. The design changes also focused on reducing PowerBuoy Installation, Operation and Maintenance (IO&M) costs which are essential to reducing the overall cost of energy. In this design, changes to the core PowerBuoy technology were implemented to increase capability and reduce both CAPEX and OPEX costs. OPT conceptually envisaged moving from a floating structure to a seabed structure. The design change from a floating structure to seabed structure would provide the implementation of stroke‐ unlimited Power Take‐Off (PTO) which has a potential to provide significant power delivery improvement and transform the wave energy industry if proven feasible.

Transient behavior of ASTRID with a gas power conversion system

Energy Technology Data Exchange (ETDEWEB)

Bertrand, F., E-mail: frederic.bertrand@cea.fr; Mauger, G.; Bensalah, M.; Gauthé, P.

2016-11-15

Highlights: • CATHARE2 transient calculations have been performed for ASTRID with a gas PCS. • The behavior of the reactor is close for gas and for water PCS in case of LOOP. • The gas PCS enables to cool the core for at least 10 h for pressurized transients. • The depressurization of the PCS induces an over-cooling for breaches on low pressure pipes. • The spurious opening of a by-pass line of the turbomachine can be controlled without scram. - Abstract: The present article is dedicated to preliminary transient studies carried out for the analysis of the system overall behavior of the ASTRID (Advanced Sodium Technological Reactor for Industrial Demonstration) demonstrator developed in France by CEA and its industrial partners. ASTRID is foreseen to demonstrate the progress made in SFR technology at an industrial scale by qualifying innovative options, some of which still remain open in the areas requiring improvements, especially safety and operability. Among the innovative options, a gas power conversion systems (PCS) is envisaged. In this innovative PCS, the working gas is nitrogen whose flow rate delivers power to a turbine driving with the same shaft two compressors (low and high pressure) separated by an intercooler. The other part of the work delivered by the gas is used to drive the alternator that produces electricity. The main objective of such a PCS consists in avoiding physically the possibility of a sodium/water reaction with the secondary circuit but the impact of this PCS on the control of incidental and accidental transients has also been studied. The main purpose of the studies presented in the paper is to assess the dynamic behavior of ASTRID including a gas PCS with the CATHARE2 code. The first transient presented deals with a loss of off-site power and has been calculated for the gas PCS but also for a classical steam/water PCS for comparison purpose. Then typical transients of gas system have been investigated. Several families of

Transient behavior of ASTRID with a gas power conversion system

International Nuclear Information System (INIS)

Bertrand, F.; Mauger, G.; Bensalah, M.; Gauthé, P.

2016-01-01

Highlights: • CATHARE2 transient calculations have been performed for ASTRID with a gas PCS. • The behavior of the reactor is close for gas and for water PCS in case of LOOP. • The gas PCS enables to cool the core for at least 10 h for pressurized transients. • The depressurization of the PCS induces an over-cooling for breaches on low pressure pipes. • The spurious opening of a by-pass line of the turbomachine can be controlled without scram. - Abstract: The present article is dedicated to preliminary transient studies carried out for the analysis of the system overall behavior of the ASTRID (Advanced Sodium Technological Reactor for Industrial Demonstration) demonstrator developed in France by CEA and its industrial partners. ASTRID is foreseen to demonstrate the progress made in SFR technology at an industrial scale by qualifying innovative options, some of which still remain open in the areas requiring improvements, especially safety and operability. Among the innovative options, a gas power conversion systems (PCS) is envisaged. In this innovative PCS, the working gas is nitrogen whose flow rate delivers power to a turbine driving with the same shaft two compressors (low and high pressure) separated by an intercooler. The other part of the work delivered by the gas is used to drive the alternator that produces electricity. The main objective of such a PCS consists in avoiding physically the possibility of a sodium/water reaction with the secondary circuit but the impact of this PCS on the control of incidental and accidental transients has also been studied. The main purpose of the studies presented in the paper is to assess the dynamic behavior of ASTRID including a gas PCS with the CATHARE2 code. The first transient presented deals with a loss of off-site power and has been calculated for the gas PCS but also for a classical steam/water PCS for comparison purpose. Then typical transients of gas system have been investigated. Several families of

A proposed strategy for power optimization of a wind energy conversion system connected to the grid

International Nuclear Information System (INIS)

Taraft, S.; Rekioua, D.; Aouzellag, D.; Bacha, S.

2015-01-01

Highlights: • Wind energy conversion based doubly fed induction generator controlled by matrix converter. • Operation at both sub and super-synchronous regions is possible with the proposed drive system. • Double the power generated by the DFIG at a twice of speed rated. • Sliding mode control is used to achieve active and reactive power control. - Abstract: Many strategies have been developed in last decade to optimize power extracted from wind energy conversion system where many of them can produce only 30% more than the rated power. With the considered strategy, the generated wind power can reach twice its nominal value using a fast and reliable fully rugged electrical control. Indeed, by employing a suitable control technique where the produced power in super-synchronous mode is derived from both the stator and the rotor. Also, the rotor provided power in this case grows up 100% comparing to stator rated power. However, this solution permits to maintain the wind energy conversion system operation in its stable area. The considered system consists of a double fed induction generator whose stator is connected directly to the grid and its rotor is supplied by matrix converter. In this paper, the sliding mode approach to achieve active and reactive power control is used. This latter is combined with de Perturbation and Observation Maximum Power Point Tracking used in the second operation zone. The obtained simulations results are assessed and carried out using Matlab/Simulink package and show the performance and the effectiveness of the proposed control

Long-distance power transmission technology. Microwave power transmission; Denryoku no chokyori yuso gijutsu. Micro ha musen soden

Energy Technology Data Exchange (ETDEWEB)

Kaya, N [Kobe University, Kobe (Japan). Faculty of Engineering

1994-11-05

This paper explains the principles of microwave power transmission as a long-distance power transmission technology, and the status of its development. Under an assumption of using a wave length of 12 cm (2.45 GHz) and a transmission distance of 1 km, an ideal wireless power transmission can realize transmitting the power at an efficiency of 95% or higher if transmitting and receiving antennas with a radius of 8.8 m are used. What remains as important requirements is raising the efficiency of conversion from power supply into microwaves, and the efficiency of rectification after the power has been received. By using microwave energy sent from a transmission antenna installed on the roof of an automobile, a model airplane with a receiving antenna installed at its rear flew successfully for 40 seconds under the microwave lifted airplane experiment (MILAX). In an experiment of transmitting microwave power in space, power was successfully transmitted to the child rocket as an event under the International Space Year - Microwave Energy Transmission in Space (ISY-METS). The microwave wireless power transmission on the ground would have a possibility of taking over the overhead line transmission into islands. An attempt is scheduled to send power of 5 kW by using transmission and receiving antennas with a diameter of 3 m to investigate effects on transmission efficiency, and communications and electromagnetic environments, and to collect basic data. 3 refs., 3 figs.

Selection of biomass thermochemical conversion technology in the Netherlands : A best worst method approach

NARCIS (Netherlands)

van de Kaa, G.; Kamp, L.M.; Rezaei, J.

2017-01-01

This paper studies the technology battle for biomass conversion in the Netherlands. Three types of technologies are currently fighting the battle for standard dominance: combustion, pyrolysis, and gasification. Twelve relevant factors for standard dominance were found: ‘financial strength’,

The NASA CSTI High Capacity Power Project

International Nuclear Information System (INIS)

Winter, J.; Dudenhoefer, J.; Juhasz, A.; Schwarze, G.; Patterson, R.; Ferguson, D.; Schmitz, P.; Vandersande, J.

1992-01-01

This paper describes the elements of NASA's CSTI High Capacity Power Project which include Systems Analysis, Stirling Power Conversion, Thermoelectric Power Conversion, Thermal Management, Power Management, Systems Diagnostics, Environmental Interactions, and Material/Structural Development. Technology advancement in all elements is required to provide the growth capability, high reliability and 7 to 10 year lifetime demanded for future space nuclear power systems. The overall project will develop and demonstrate the technology base required to provide a wide range of modular power systems compatible with the SP-100 reactor which facilitates operation during lunar and planetary day/night cycles as well as allowing spacecraft operation at any attitude or distance from the sun. Significant accomplishments in all of the project elements will be presented, along with revised goals and project timeliness recently developed

A Review of Previous Research in Direct Energy Conversion Fission Reactors

International Nuclear Information System (INIS)

DUONG, HENRY; POLANSKY, GARY F.; SANDERS, THOMAS L.; SIEGEL, MALCOLM D.

1999-01-01

From the earliest days of power reactor development, direct energy conversion was an obvious choice to produce high efficiency electric power generation. Directly capturing the energy of the fission fragments produced during nuclear fission avoids the intermediate conversion to thermal energy and the efficiency limitations of classical thermodynamics. Efficiencies of more than 80% are possible, independent of operational temperature. Direct energy conversion fission reactors would possess a number of unique characteristics that would make them very attractive for commercial power generation. These reactors would be modular in design with integral power conversion and operate at low pressures and temperatures. They would operate at high efficiency and produce power well suited for long distance transmission. They would feature large safety margins and passively safe design. Ideally suited to production by advanced manufacturing techniques, direct energy conversion fission reactors could be produced more economically than conventional reactor designs. The history of direct energy conversion can be considered as dating back to 1913 when Moseleyl demonstrated that charged particle emission could be used to buildup a voltage. Soon after the successful operation of a nuclear reactor, E.P. Wigner suggested the use of fission fragments for direct energy conversion. Over a decade after Wigner's suggestion, the first theoretical treatment of the conversion of fission fragment kinetic energy into electrical potential appeared in the literature. Over the ten years that followed, a number of researchers investigated various aspects of fission fragment direct energy conversion. Experiments were performed that validated the basic physics of the concept, but a variety of technical challenges limited the efficiencies that were achieved. Most research in direct energy conversion ceased in the US by the late 1960s. Sporadic interest in the concept appears in the literature until this

IECEC '91; Proceedings of the 26th Intersociety Energy Conversion Engineering Conference, Boston, MA, Aug. 4-9, 1991. Vol 6

International Nuclear Information System (INIS)

Anon.

1991-01-01

Papers are presented on aerospace power systems (burst and pulse power, simulation, solar dynamics, and space nuclear systems, etc.), conversion technologies, electrochemical conversion, and energy conservation. Consideration is also given to energy systems and alternative fuels, renewable resource systems, Stirling engines and applications, and innovative and advanced systems (e.g., superconducting power and magnetic devices at high temperature)

Pretreated Landfill Gas Conversion Process via a Catalytic Membrane Reactor for Renewable Combined Fuel Cell-Power Generation

Directory of Open Access Journals (Sweden)

Zoe Ziaka

2013-01-01

Full Text Available A new landfill gas-based reforming catalytic processing system for the conversion of gaseous hydrocarbons, such as incoming methane to hydrogen and carbon oxide mixtures, is described and analyzed. The exit synthesis gas (syn-gas is fed to power effectively high-temperature fuel cells such as SOFC types for combined efficient electricity generation. The current research work is also referred on the description and design aspects of permreactors (permeable reformers carrying the same type of landfill gas-reforming reactions. Membrane reactors is a new technology that can be applied efficiently in such systems. Membrane reactors seem to perform better than the nonmembrane traditional reactors. The aim of this research includes turnkey system and process development for the landfill-based power generation and fuel cell industries. Also, a discussion of the efficient utilization of landfill and waste type resources for combined green-type/renewable power generation with increased processing capacity and efficiency via fuel cell systems is taking place. Moreover, pollution reduction is an additional design consideration in the current catalytic processors fuel cell cycles.

Proceedings of the 27th intersociety energy conversion engineering conference

International Nuclear Information System (INIS)

Anon.

1992-01-01

This book contains the proceedings of the 27th Intersociety Energy Conversion Engineering Conference. Topics included: Stirling Cycle Analysis; Stirling Cycle Models; Stirling Refrigerators/Heat Pumps and Cryocoolers; Domestic Policy; Efficiency/Conservation; Stirling Solar Terrestrial; Stirling Component Technology; Environmental Impacts; Renewable Resource Systems; Stirling Power Generation; Stirling Heat Transport System Technology; and Stirling Cycle Loss Understanding

Wavelength conversion technology

DEFF Research Database (Denmark)

Stubkjær, Kristian

1998-01-01

Optical wavelength conversion is currently attracting much interest. This is because it enables full flexibility and eases management of WDM fibre networks. The tutorial will review existing and potential application areas. Examples of node architectures and network demonstrators that use wavelen...

EPRI nuclear power plant decommissioning technology program

International Nuclear Information System (INIS)

Kim, Karen S.; Bushart, Sean P.; Naughton, Michael; McGrath, Richard

2011-01-01

The Electric Power Research Institute (EPRI) is a non-profit research organization that supports the energy industry. The Nuclear Power Plant Decommissioning Technology Program conducts research and develops technology for the safe and efficient decommissioning of nuclear power plants. (author)

Review of direct energy conversion for fusion reactors

International Nuclear Information System (INIS)

Barr, W.L.; Moir, R.W.

1976-01-01

The direct conversion to electrical energy of the energy carried by the leakage plasma from a fusion reactor and by the ions that are not converted to neutrals in a neutral-beam injector is discussed. The conversion process is electrostatic deceleration and direct particle collection as distinct from plasma expansion against a time-varying magnetic field or conversion in an EXB duct (both MHD). Relatively simple 1-stage plasma direct converters are discussed which can have efficiencies of about 50 percent. More complex and costly (measured in $/kW) 2-, 3-, 4-, and 22-stage concepts have been tested at efficiencies approaching 90 percent. Beam direct converters have been tested at 15 keV and 2 kW of power at 70 +- 2 percent efficiency, and a test of a 120-keV, 1-MW version is being prepared. Designs for a 120-keV, 4-MW unit are presented. The beam direct converter, besides saving on power supplies and on beam dumps, should raise the efficiency of creating a neutral beam from 40 percent without direct conversion to 70 percent with direct conversion for a 120-keV deuterium beam. The technological limits determining power handling and lifetime such as space-charge effects, heat removal, electrode material, sputtering, blistering, voltage holding, and insulation design, are discussed. The application of plasma direct converters to toroidal plasma confinement concepts is also discussed

A novel on-chip high to low voltage power conversion circuit

International Nuclear Information System (INIS)

Wang Hui; Wang Songlin; Mou Zaixin; Guo Baolong; Lai Xinquan; Ye Qiang; Li Xianrui

2009-01-01

A novel power supply transform technique for high voltage IC based on the TSMC 0.6 μm BCD process is achieved. An adjustable bandgap voltage reference is presented which is different from the traditional power supply transform technique. It can be used as an internal power supply for high voltage IC by using the push-pull output stage to enhance its load capability. High-order temperature compensated circuit is designed to ensure the precision of the reference. Only 0.01 mm 2 area is occupied using this novel power supply technique. Compared with traditional technique, 50% of the area is saved, 40% quiescent power loss is decreased, and the temperature coefficient of the reference is only 4.48 ppm/deg. C. Compared with the traditional LDO (low dropout) regulator, this power conversion architecture does not need external output capacitance and decreases the chip-pin and external components, so the PCB area and design cost are also decreased. The testing results show that this circuit works well.

A novel on-chip high to low voltage power conversion circuit

Energy Technology Data Exchange (ETDEWEB)

Wang Hui; Wang Songlin; Mou Zaixin; Guo Baolong [Institute of Mechano-electronic Engineering, Xidian University, Xi' an 71007 (China); Lai Xinquan; Ye Qiang; Li Xianrui, E-mail: whui94@126.co [Institute of Electronic CAD, Xidian University, Xi' an 710071 (China)

2009-03-15

A novel power supply transform technique for high voltage IC based on the TSMC 0.6 mum BCD process is achieved. An adjustable bandgap voltage reference is presented which is different from the traditional power supply transform technique. It can be used as an internal power supply for high voltage IC by using the push-pull output stage to enhance its load capability. High-order temperature compensated circuit is designed to ensure the precision of the reference. Only 0.01 mm{sup 2} area is occupied using this novel power supply technique. Compared with traditional technique, 50% of the area is saved, 40% quiescent power loss is decreased, and the temperature coefficient of the reference is only 4.48 ppm/deg. C. Compared with the traditional LDO (low dropout) regulator, this power conversion architecture does not need external output capacitance and decreases the chip-pin and external components, so the PCB area and design cost are also decreased. The testing results show that this circuit works well.

Evaluation for reasonableness of power conversion system concepts in the gas turbine high temperature reactor (GTHTR300)

International Nuclear Information System (INIS)

Minatsuki, I.; Mizokami, Y.

2007-01-01

The conceptual design study for the Gas Turbine High Temperature Reactor (GTHTR300) was completed in 2004. In GTHTR300, SECO (Simple, Economical Competitiveness and Originality) is advocated as design philosophy in order to minimize technical and economical requirement. Furthermore the design of the GTHTR300 was developed with reflecting various view points from utilities, manufacturers and research organizations. In GTHTR300, the horizontal turbo machine rotor, the turbo machine in a separated vessel, the turbo machine with single rotor, the generator inside the power conversion vessel, and the power conversion system without inter-coolers were selected as major power conversion system concepts. This paper describes the investigation and analysis about the major concepts of GTHTR300 power conversion system in order to evaluate reasonableness of GTHTR300 design approach and acceptability with using experience and engineering knowledge of Mitsubishi Heavy Industries, Ltd., which were accumulated through the activities of HTGR-GT and HTTR (High Temperature Engineering Test Reactor) designing, manufacturing, fabricating and testing. From the result of the evaluation, it was concluded that the selection of each concept in GTHTR300 was reasonable as based on the original design philosophy SECO. As a conclusion, we expect the GTHTR300 to become one of the most promising concepts for commercialization in near future. (authors)

Coal conversion process by the United Power Plants of Westphalia

Energy Technology Data Exchange (ETDEWEB)

1974-08-01

The coal conversion process used by the United Power Plants of Westphalia and its possible applications are described. In this process, the crushed and predried coal is degassed and partly gasified in a gas generator, during which time the sulfur present in the coal is converted into hydrogen sulfide, which together with the carbon dioxide is subsequently washed out and possibly utilized or marketed. The residual coke together with the ashes and tar is then sent to the melting chamber of the steam generator where the ashes are removed. After desulfurization, the purified gas is fed into an external circuit and/or to a gas turbine for electricity generation. The raw gas from the gas generator can be directly used as fuel in a conventional power plant. The calorific value of the purified gas varies from 3200 to 3500 kcal/cu m. The purified gas can be used as reducing agent, heating gas, as raw material for various chemical processes, or be conveyed via pipelines to remote areas for electricity generation. The conversion process has the advantages of increased economy of electricity generation with desulfurization, of additional gas generation, and, in long-term prospects, of the use of the waste heat from high-temperature nuclear reactors for this process.

Gas-fired electric power generating technologies

International Nuclear Information System (INIS)

1994-09-01

The workshop that was held in Madrid 25-27 May 1994 included participation by experts from 16 countries. They represented such diverse fields and disciplines as technology, governmental regulation, economics, and environment. Thus, the participants provided an excellent cross section of key areas and a diversity of viewpoints. At the workshop, a broad range of topics regarding gas-fired electric power generation was discussed. These included political, regulatory and financial issues as well as more specific technical questions regarding the environment, energy efficiency, advanced generation technologies and the status of competitive developments. Important technological advances in gas-based power and CHP technologies have already been achieved including higher energy efficiency and lower emissions, with further improvements expected in the near future. Advanced technology trends include: (a) The use of gas technology to reduce emissions from existing coal-fired power plants. (b) The wide-spread application of combined-cycle gas turbines in new power plants and the growing use of aero-derivative gas turbines in CHP applications. (c) Phosphoric acid fuel cells that are being introduced commercially. Their market penetration will grow over the next 10 years. The next generation of fuel cells (solid oxide and molten carbonate) is expected to enter the market around the year 2000. (EG)

Improved flexibility with large-scale variable renewable power in cities through optimal demand side management and power-to-heat conversion

International Nuclear Information System (INIS)

Salpakari, Jyri; Mikkola, Jani; Lund, Peter D.

2016-01-01

Highlights: • New models for optimal control of shiftable loads and power-to-heat conversion. • Full technical and economic potential with optimal controls. • Detailed time series of shiftable loads based on empirical data. • Case study of Helsinki (Finland) with over 90% share of district heating. • Positive net present values in cost-optimal operation. - Abstract: Solar and wind power are potential carbon-free energy solutions for urban areas, but they are also subject to large variability. At the same time, urban areas offer promising flexibility solutions for balancing variable renewable power. This paper presents models for optimal control of power-to-heat conversion to heating systems and shiftable loads in cities to incorporate large variable renewable power schemes. The power-to-heat systems comprise heat pumps, electric boilers, and thermal storage. The control strategies comprise optimal matching of load and production, and cost-optimal market participation with investment analysis. All analyses are based on hourly data. The models are applied to a case study in Helsinki, Finland. For a scheme providing ca. 50% of all electricity in the city through self-consumption of variable renewables, power-to-heat with thermal storage could absorb all the surplus production. A significant reduction in the net load magnitude was obtained with shiftable loads. Investments to both power-to-heat and load shifting with electric heating and commercial refrigeration have a positive net present value if the resources are controlled cost-optimally.

Investigation of greenhouse gas reduction potential and change in technological selection in Indian power sector

International Nuclear Information System (INIS)

Mathur, Jyotirmay; Bansal, Narendra Kumar; Wagner, H.-J.

2003-01-01

Due to the growing energy needs along with increasing concerns towards control of greenhouse gas emissions, most developing countries are under pressure to find alternative methods for energy conversion and policies to make these technologies economically viable. One of the instruments that have been adopted by many industrial countries is that of the carbon tax. The rate of introducing carbon taxes however, depends upon the local economic conditions and market forces. The case of Indian power sector has been examined by using MARKAL model for introduction of carbon taxes at four different trajectories. Their implications on the power generation choices have been investigated for a time span of 25 years from the year 2000. In general large hydropower plants have emerged as the first choice followed by wind energy systems. However, cheaper availability of coal in India keeps scope of use of coal based technologies for which pressurised fluidised bed combustion technology has been found to be the balanced choice among fossil technologies. There exists a potential of reduction of greenhouse gas emissions by about 25% as compared to the 'business-as-usual' case in presence of high carbon tax rates

Overview of NASA Lewis Research Center free-piston Stirling engine technology activities applicable to space power systems

Science.gov (United States)

Slaby, Jack G.

1987-01-01

A brief overview is presented of the development and technological activities of the free-piston Stirling engine. The engine started as a small scale fractional horsepower engine which demonstrated basic engine operating principles and the advantages of being hermetically sealed, highly efficient, and simple. It eventually developed into the free piston Stirling engine driven heat pump, and then into the SP-100 Space Reactor Power Program from which came the Space Power Demonstrator Engine (SPDE). The SPDE successfully operated for over 300 hr and delivered 20 kW of PV power to an alternator plunger. The SPDE demonstrated that a dynamic power conversion system can, with proper design, be balanced; and the engine performed well with externally pumped hydrostatic gas bearings.

Designing Energy Conversion Systems for the Next Decade

Directory of Open Access Journals (Sweden)

Slobodan N. Vukosavić

2012-12-01

Full Text Available Sustainable growth in energy consumption requires transition to clean and green energy sources and energy systems. Environment friendly and renewable energy systems deal with electrical energy and rely on efficient electrical power converters. High power electronics is the key technology to deal with the next generation of electrical energy systems. The door to future breakthroughs in high power electronics is opened by major improvement in semiconductor power devices and their packaging technologies. New materials allow for much higher junction temperatures and higher operating voltages. Most importantly, advanced power semiconductor devices and novel converter topology open the possibility to increase the energy efficiency of power conversion and reduce the amount of heat. Although the waste heat created by high power converters can be put to use by adding on to heating systems, this option is not always available and the conversion losses are mostly wasted. At the same time, wasted heat is a form of pollution that threatens the environment. Another task for high power converters is efficient harvesting of renewable energy sources, such as the wind energy and the sun. Intermittent in nature, they pose a difficult task to power converter topology and controls. Eventually, high power converters are entering power distribution and transmission networks. With their quick reaction, with fast communication between the grid nodes and with advanced controllability of high power converters, a number of innovations can be introduced, facilitating the power system control and allowing for optimizations and loss reduction. Coined smart grid, this solution comprises two key elements, and these are intelligent controls and large static power converters. At virtually no cost, smart grids allow for a better utilization of available resources and it enlarges the stable operating range of the transmission systems. Therefore, it is of interest to review the

Biomass combustion technologies for power generation

Energy Technology Data Exchange (ETDEWEB)

Wiltsee, G.A. Jr. [Appel Consultants, Inc., Stevenson Ranch, CA (United States); McGowin, C.R.; Hughes, E.E. [Electric Power Research Institute, Palo Alto, CA (United States)

1993-12-31

Technology in power production from biomass has been advancing rapidly. Industry has responded to government incentives such as the PURPA legislation in the US and has recognized that there are environmental advantages to using waste biomass as fuel. During the 1980s many new biomass power plants were built. The relatively mature stoker boiler technology was improved by the introduction of water-cooled grates, staged combustion air, larger boiler sizes up to 60 MW, higher steam conditions, and advanced sootblowing systems. Circulating fluidized-bed (CFB) technology achieved full commercial status, and now is the leading process for most utility-scale power applications, with more complete combustion, lower emissions, and better fuel flexibility than stoker technology. Bubbling fluidized-bed (BFB) technology has an important market niche as the best process for difficult fuels such as agricultural wastes, typically in smaller plants. Other biomass power generation technologies are being developed for possible commercial introduction in the 1990s. Key components of Whole Tree Energy{trademark} technology have been tested, conceptual design studies have been completed with favorable results, and plans are being made for the first integrated process demonstration. Fluidized-bed gasification processes have advanced from pilot to demonstration status, and the world`s first integrated wood gasification/combined cycle utility power plant is starting operation in Sweden in early 1993. Several European vendors offer biomass gasification processes commercially. US electric utilities are evaluating the cofiring of biomass with fossil fuels in both existing and new plants. Retrofitting existing coal-fired plants gives better overall cost and performance results than any biomass technologies;but retrofit cofiring is {open_quotes}fuel-switching{close_quotes} that provides no new capacity and is attractive only with economic incentives.

A New Cost-Effective Multi-Drive Solution based on a Two-Stage Direct Power Electronic Conversion Topology

DEFF Research Database (Denmark)

Klumpner, Christian; Blaabjerg, Frede

2002-01-01

of a protection circuit involving twelve diodes with full voltage/current ratings used only during faulty situations, makes this topology not so attractive. Lately, two stage Direct Power Electronic Conversion (DPEC) topologies have been proposed, providing similar functionality as a matrix converter but allowing...... shared by many loads, making this topology more cost effective. The functionality of the proposed two-stage multi-drive direct power electronic conversion topology is validated by experiments on a realistic laboratory prototype....

Research in Support of the Use of Rankine Cycle Energy Conversion Systems for Space Power and Propulsion

Science.gov (United States)

Lahey, Richard T., Jr.; Dhir, Vijay

2004-01-01

This is the report of a Scientific Working Group (SWG) formed by NASA to determine the feasibility of using a liquid metal cooled nuclear reactor and Rankine energy conversion cycle for dual purpose power and propulsion in space. This is a high level technical report which is intended for use by NASA management in program planning. The SWG was composed of a team of specialists in nuclear energy and multiphase flow and heat transfer technology from academia, national laboratories, NASA and industry. The SWG has identified the key technology issues that need to be addressed and have recommended an integrated short term (approx. 2 years) and a long term (approx. 10 year) research and development (R&D) program to qualify a Rankine cycle power plant for use in space. This research is ultimately intended to give NASA and its contractors the ability to reliably predict both steady and transient multiphase flow and heat transfer phenomena at reduced gravity, so they can analyze and optimize designs and scale-up experimental data on Rankine cycle components and systems. In addition, some of these results should also be useful for the analysis and design of various multiphase life support and thermal management systems being considered by NASA.

Space power subsystem automation technology

Science.gov (United States)

Graves, J. R. (Compiler)

1982-01-01

The technology issues involved in power subsystem automation and the reasonable objectives to be sought in such a program were discussed. The complexities, uncertainties, and alternatives of power subsystem automation, along with the advantages from both an economic and a technological perspective were considered. Whereas most spacecraft power subsystems now use certain automated functions, the idea of complete autonomy for long periods of time is almost inconceivable. Thus, it seems prudent that the technology program for power subsystem automation be based upon a growth scenario which should provide a structured framework of deliberate steps to enable the evolution of space power subsystems from the current practice of limited autonomy to a greater use of automation with each step being justified on a cost/benefit basis. Each accomplishment should move toward the objectives of decreased requirement for ground control, increased system reliability through onboard management, and ultimately lower energy cost through longer life systems that require fewer resources to operate and maintain. This approach seems well-suited to the evolution of more sophisticated algorithms and eventually perhaps even the use of some sort of artificial intelligence. Multi-hundred kilowatt systems of the future will probably require an advanced level of autonomy if they are to be affordable and manageable.

Advance Power Technology Demonstration on Starshine 3

Science.gov (United States)

Jenkins, Phillip; Scheiman, David; Wilt, David; Raffaelle, Ryne; Button, Robert; Smith, Mark; Kerslake, Thomas; Miller, Thomas

2002-01-01

The Starshine 3 satellite will carry several power technology demonstrations. Since Starshine 3 is primarily a passive experiment and does not need electrical power to successfully complete its mission, the requirement for a highly reliable power system is greatly reduced. This creates an excellent opportunity to test new power technologies. Several government and commercial interests have teamed up to provide Starshine 3 with a small power system using state-of-the-art components. Starshine 3 will also fly novel integrated microelectronic power supplies (IMPS) for evaluation.

Research on process management of nuclear power technological innovation

International Nuclear Information System (INIS)

Yang Hua; Zhou Yu

2005-01-01

Different from the other technological innovation processes, the technological innovation process of nuclear power engineering project is influenced deeply by the extensive environmental factors, the technological innovation of nuclear power engineering project needs to make an effort to reduce environmental uncertainty. This paper had described the mechanism of connection technological innovation process of nuclear power engineering project with environmental factors, and issued a feasible method based on model of bargaining to incorporate technological innovation process management of nuclear power engineering project with environmental factors. This method has realistic meanings to guide the technological innovation of nuclear power engineering project. (authors)

Power from Pellets Technology and Applications

CERN Document Server

Döring, Stefan

2013-01-01

This book provides a practical description of the technology of pellet production on the basis of renewable sources as well as the utilization of pellets. The author explains what kinds of biomass are usable in addition to wood, how to produce pellets and how to use pellets to produce energy. Starting with the basics of combustion, gasification and the pelletizing process, several different technologies are described. The design, planning, construction and economic efficiency are discussed as well. The appendix gives useful advice about plant concepts, calculations, addresses, conversion tables and formulas.

Localization of nuclear power plant technology

International Nuclear Information System (INIS)

Stiteler, F.Z.; Rudek, T.G.

1998-01-01

Asia, and particularly China, has an enormous need for power and must deal with the practicalities of building large base load units. In China, as in other countries, there are limitations on the use of large quantities of fossil fuel. This raises the possibility of turning to nuclear power to satisfy their energy needs. Other issues tend to point to the nuclear option for these growing economies, including economic considerations, environmental concerns, energy independence and raising the technological capabilities of the country. When a country embarks on a nuclear power program with the intention of localizing the technology, a long-term commitment is necessary to achieve this objective. Localization of nuclear technology is not a new phenomenon. The nature of the industry from the early beginnings has always involved transfer of technology when a new country initiated a nuclear power construction program. In fact, most previous experiences with this localization process involved heavy governmental, political and financial support to drive the success of the program. Because of this strong governmental support, only the receiving nation's companies were generally allowed to participate in the local business operations of the technology recipient. What is new and different today is the retreat from heavy financial support by the receiving country's government. This change has created a strong emphasis on cost-effectiveness in the technology transfer process and opportunities for foreign companies to participate in local business activities. ABB is a world-wide company with two parent companies that have been very active over many years in establishing cost-justified local operations throughout the world. Today, ABB has become the largest electrical engineering company in the world with respected local operations in nearly every country. Lessons learned by ABB in their world-wide localization initiatives are being applied to the challenge of cost

Advanced radioisotope power source options for Pluto Express

International Nuclear Information System (INIS)

Underwood, M.L.

1995-01-01

In the drive to reduce mass and cost, Pluto Express is investigating using an advanced power conversion technology in a small Radioisotope Power Source (RPS) to deliver the required mission power of 74 W(electric) at end of mission. Until this year the baseline power source under consideration has been a Radioisotope Thermoelectric Generator (RTG). This RTG would be a scaled down GPHS RTG with an inventory of 6 General Purpose Heat Sources (GPHS) and a mass of 17.8 kg. High efficiency, advanced technology conversion options are being examined to lower the power source mass and to reduce the amount of radioisotope needed. Three technologies are being considered as the advanced converter technology: the Alkali Metal Thermal-to-Electric Converter (AMTEC), Thermophotovoltaic (TPV) converters, and Stirling Engines. Conceptual designs for each of these options have been prepared. Each converter would require only 2 GPHSs to provide the mission power and would have a mass of 6.1, 7.2, and 12.4 kg for AMTEC, TPV, and Stirling Engines respectively. This paper reviews the status of each technology and the projected performance of an advanced RPS based on each technology. Based on the projected performance and spacecraft integration issues, Pluto Express would prefer to use the AMTEC based RPS. However, in addition to technical performance, selection of a power technology will be based on many other factors

Induction linacs and pulsed power

International Nuclear Information System (INIS)

Caporaso, G.J.

1995-01-01

Progress in electronic power conversion technology is making possible a new class of induction linacs that can operate at extremely high repetition rates. Advances in insulator technology, pulse forming line design and switching may also lead to a new type of high current accelerator with accelerating gradients at least an order of magnitude greater than those attainable today. The evolution of the induction accelerator pulsed power system will be discussed along with some details of these emerging technologies which are at the frontiers of accelerator technology

Commercialization of terrestrial applications of aerospace power technology

International Nuclear Information System (INIS)

Landsberg, D.R.

1992-01-01

The potential for commercialization of terrestrial energy systems based upon aerospace power technology's explored. Threats to the aerospace power technology industry, caused by the end of the cold war and weak world economy are described. There are also new opportunities caused by increasing terrestrial energy needs and world-wide concern for the environment. In this paper, the strengths and weaknesses of the aerospace power industry in commercializing terrestrial energy technologies are reviewed. Finally, actions which will enable the aerospace power technology industry to commercialize products into terrestrial energy markets are described

Use of nuclear space technology of direct energy conversion for terrestrial application

International Nuclear Information System (INIS)

Chitaykin, V.I.; Meleta, Ye.A.; Yarygin, V.I.; Mikheyev, A.S.; Tulin, S.M.

2000-01-01

In due time the SSC RF-IPPE exercised the scientific supervision and directly participated in the development, fabrication, space flight test and maintenance of the direct energy conversion nuclear power plants (NPP) for space application under the 'BUK' and 'TOPAZ' programs. We have used the acquired experience and the high technologies developed for the 'BUK' NPP with a thermoelectric conversion of thermal (nuclear) energy into electrical one in the development under the order of RAO 'GAZPROM' of the natural gas fired self contained thermoelectric current sources (AIT-500) and heat and electricity sources (TEP-500). These are intended for electrochemical rust protection of gas pipelines and for the electricity and heat supply to the telemetric and microwave-link systems located along the gas pipelines. Of special interest at the moment are the new developments of self contained current sources with the electrical output of ∼500 Wel for new gas pipelines being constructed under the projects such as the 'Yamal-Europe' project. The electrochemical rust protection of gas pipelines laying on unsettled and non-electrified territory of arctic regions of Russia is performed by means of the so-called Cathodic Protection Stations (CPS). Accounting for a complex of rather rigid requirements imposed by arctic operating conditions, the most attractive sources of electricity supply to the CPS are the thermoelectric heat-into-electricity converters and the generators (TEG). This paper deals with the essential results of the development, investigation and testing of unconventional TEGs using the low-temperature bismuth-tellurium thermoelectric batteries assembled together as tubular thermoelectric batteries with a radial ring geometry built into the gas-heated thermoelectric modules, which are collected to make up either the thermoelectric plants for heat and electricity supply or the self contained power sources. One of the peculiarities of these plants is the combination of

Test Results from a Direct Drive Gas Reactor Simulator Coupled to a Brayton Power Conversion Unit

Science.gov (United States)

Hervol, David S.; Briggs, Maxwell H.; Owen, Albert K.; Bragg-Sitton, Shannon M.; Godfroy, Thomas J.

2010-01-01

Component level testing of power conversion units proposed for use in fission surface power systems has typically been done using relatively simple electric heaters for thermal input. These heaters do not adequately represent the geometry or response of proposed reactors. As testing of fission surface power systems transitions from the component level to the system level it becomes necessary to more accurately replicate these reactors using reactor simulators. The Direct Drive Gas-Brayton Power Conversion Unit test activity at the NASA Glenn Research Center integrates a reactor simulator with an existing Brayton test rig. The response of the reactor simulator to a change in Brayton shaft speed is shown as well as the response of the Brayton to an insertion of reactivity, corresponding to a drum reconfiguration. The lessons learned from these tests can be used to improve the design of future reactor simulators which can be used in system level fission surface power tests.

NUCLEAR THERMIONIC SPACE POWER SYSTEMS

Energy Technology Data Exchange (ETDEWEB)

Howard, R. C.; Rasor, N. S.

1963-03-15

The various concepts for utilizing thermionic conversion in space reactor power plants are described and evaluated. The problems (and progress toward their solution) of the in-core concept, particularly, are considered. Progress in thermionic conversion technology is then reviewed from both the hardware and research points of view. Anticipated progress in thermionic conversion and the possible consequences for the performance of electrical propulsion systems are summarized. 46 references. (D.C.W.)

Comparative analysis of concentrating solar power and photovoltaic technologies: Technical and environmental evaluations

International Nuclear Information System (INIS)

Desideri, U.; Zepparelli, F.; Morettini, V.; Garroni, E.

2013-01-01

Highlights: ► Life cycle was assessed for both concentrated solar power and photovoltaic systems. ► The PV plant has a higher environmental impact than the CSP plant. ► The Global Warming Potential is lower for the CSP than for the PV plant. ► The energy payback time is lower for the CSP than for the PV plant. -- Abstract: Solar energy is an important alternative energy source to fossil fuels and theoretically the most available energy source on the earth. Solar energy can be converted into electric energy by using two different processes: by means of thermodynamic cycles and the photovoltaic conversion. Solar thermal technologies, sometimes called thermodynamic solar technologies, operating at medium (about 500 °C) and high temperatures (about 1000 °C), have recently attracted a renewed interest and have become one of the most promising alternatives in the field of solar energy utilization. Photovoltaic conversion is very interesting, although still quite expensive, because of the absence of moving components and the reduced operating and management costs. The main objectives of the present work are: •to carry out comparative technical evaluations on the amount of electricity produced by two hypothetical plants, located on the same site, for which a preliminary design was made: a solar thermal power plant with parabolic trough collectors and a photovoltaic plant with a single-axis tracking system; •to carry out a comparative analysis of the environmental impact derived from the processes of electricity generation during the whole life cycle of the two hypothetical power plants. First a technical comparison between the two plants was made assuming that they have the same nominal electric power and then the same total covered surface. The methodology chosen to evaluate the environmental impact associated with the power plants is the Life Cycle Assessment (LCA). It allows to analyze all the phases of the life cycle of the plants, from the extraction of

Solar Energy: Its Technologies and Applications

Science.gov (United States)

Auh, P. C.

1978-06-01

Solar heat, as a potential source of clean energy, is available to all of us. Extensive R and D efforts are being made to effectively utilize this renewable energy source. A variety of different technologies for utilizing solar energy have been proven to be technically feasible. Here, some of the most promising technologies and their applications are briefly described. These are: Solar Heating and Cooling of Buildings (SHACOB), Solar Thermal Energy Conversion (STC), Wind Energy Conversion (WECS), Bioconversion to Fuels (BCF), Ocean Thermal Energy Conversion (OTEC), and Photovoltaic Electric Power Systems (PEPS). Special emphasis is placed on the discussion of the SHACOB technologies, since the technologies are being expeditiously developed for the near commercialization.

Space Solar Power Technology Demonstration for Lunar Polar Applications: Laser-Photovoltaic Wireless Power Transmission

Science.gov (United States)

Henley, M. W.; Fikes, J. C.; Howell, J.; Mankins, J. C.; Howell, Joe T. (Technical Monitor)

2002-01-01

Space Solar Power technology offers unique benefits for near-term NASA space science missions, which can mature this technology for other future applications. "Laser-Photo-Voltaic Wireless Power Transmission" (Laser-PV WPT) is a technology that uses a laser to beam power to a photovoltaic receiver, which converts the laser's light into electricity. Future Laser-PV WPT systems may beam power from Earth to satellites or large Space Solar Power satellites may beam power to Earth, perhaps supplementing terrestrial solar photo-voltaic receivers. In a near-term scientific mission to the moon, Laser-PV WPT can enable robotic operations in permanently shadowed lunar polar craters, which may contain ice. Ground-based technology demonstrations are proceeding, to mature the technology for this initial application, in the moon's polar regions.

Inertial confinement fusion reaction chamber and power conversion system study. Final report

International Nuclear Information System (INIS)

Maya, I.; Schultz, K.R.; Bourque, R.F.

1985-10-01

This report summarizes the results of the second year of a two-year study on the design and evaluation of the Cascade concept as a commercial inertial confinement fusion (ICF) reactor. We developed a reactor design based on the Cascade reaction chamber concept that would be competitive in terms of both capital and operating costs, safe and environmentally acceptable in terms of hazard to the public, occupational exposure and radioactive waste production, and highly efficient. The Cascade reaction chamber is a double-cone-shaped rotating drum. The granulated solid blanket materials inside the rotating chamber are held against the walls by centrifugal force. The fusion energy is captured in a blanket of solid carbon, BeO, and LiAlO 2 granules. These granules are circulated to the primary side of a ceramic heat exchanger. Primary-side granule temperatures range from 1285 K at the LiAlO 2 granule heat exchanger outlet to 1600 K at the carbon granule heat exchanger inlet. The secondary side consists of a closed-cycle gas turbine power conversion system with helium working fluid, operating at 1300 K peak outlet temperature and achieving a thermal power conversion efficiency of 55%. The net plant efficiency is 49%. The reference design is a plant producing 1500 MW of D-T fusion power and delivering 815 MW of electrical power for sale to the utility grid. 88 refs., 44 figs., 47 tabs

The Impacts on Illegal Farmland Conversion of Adopting Remote Sensing Technology for Land Inspection in China

Directory of Open Access Journals (Sweden)

Taiyang Zhong

2014-07-01

Full Text Available While China’s central government has adopted remote sensing technology in land inspection since 2000, little empirical research has been done on its effect. This study aims to measure the effect of satellite imagery-based land inspection (SIBI on illegal farmland conversion. The data used in this study were collected for the period from 1997 to 2010 at the province-level. The econometrics approach for panel data model was used in this research. The results showed that SIBI has a deterrent effect of approximately 2.42 ha for every increase of 1% in proportion to the area of prefecture-level regions inspected in a province-level region. The results also indicate land inspections with RS (Remote Sensing technology saved approximately 11,880 ha farmland from illegal conversion during 2000–2010 with an estimated contribution of reducing illegal farmland conversion by nearly 11%. Furthermore, the governance structure change for land inspection has also contributed to deterring illegal farmland conversion. The deterrent effects due to land inspection by the Supervisor of State Land (SSL are about 7332 ha during 2008–2010 with an estimated contribution of reducing illegal farmland conversion by nearly 33%. In conclusion, although SIBI has strengthened China’s central capacity to uncover illegal farmland conversion and weakened local governments’ abilities to hide illegal farmland conversion, it has limited impact on illegal farmland conversion since it is just a technical tool. Improvements in the land inspection governance structure have also helped to deter illegal farmland conversion.

Proceedings of the 1998 international joint power generation conference (FACT-Vol.22). Volume 1: Fuels and combustion technologies; Gas turbines; Environmental engineering; Nuclear engineering

International Nuclear Information System (INIS)

Gupta, A.; Natole, R.; Sanyal, A.; Veilleux, J.

1998-01-01

Papers are arranged under the following topical sections: Fuels and combustion technologies; Low NOx burner applications; Low cost solutions to utility NOx compliance issues; Coal combustion--Retrofit experiences, low NOx, and efficiency; Highly preheated air combustion; Combustion control and optimization; Advanced technology for gas fuel combustion; Spray combustion and mixing; Efficient power generation using gas turbines; Safety issues in power industry; Efficient and environmentally benign conversion of wastes to energy; Artificial intelligence monitoring, control, and optimization of power plants; Combustion modeling and diagnostics; Advanced combustion technologies and combustion synthesis; Aero and industrial gas turbine presentations IGTI gas turbine division; NOx/SO 2 ; Plant cooling water system problems and solutions; Issues affecting plant operations and maintenance; and Costs associated with operating and not operating a nuclear power plant. Papers within scope have been processed separately for inclusion on the database

Reactive power management of power networks with wind generation

CERN Document Server

Amaris, Hortensia; Ortega, Carlos Alvarez

2012-01-01

As the energy sector shifts and changes to focus on renewable technologies, the optimization of wind power becomes a key practical issue. Reactive Power Management of Power Networks with Wind Generation brings into focus the development and application of advanced optimization techniques to the study, characterization, and assessment of voltage stability in power systems. Recent advances on reactive power management are reviewed with particular emphasis on the analysis and control of wind energy conversion systems and FACTS devices. Following an introduction, distinct chapters cover the 5 key

Power management of a wind energy conversion system equipped by DFIG

Directory of Open Access Journals (Sweden)

Iman Zangiabadi

2016-06-01

Full Text Available Today wind is one of the attractive points of energy area which has got the noticeable amount of investment and studies in this field. Considering the importance of the wind energy and its potentials as one of the renewable energy sources, in this paper managing the production of active and reactive powers of a wind energy conversion system equipped with DFIG has been studied. In this regard, a structure based on vector control is offered to achieve an independent control of active and reactive powers. The strategy of managing the production of active and reactive power is applied to network by rotor side converter of a DFIG. The production of active power according to the maximum power point taking (MPPT strategy to get a maximum power of the wind energy has been done and also improvement of power quality based on strategies of power factor correction and harmonics reduction have been arranged for a power network. In order to evaluate the performance of the proposed method, a DFIG connected with a power network in different conditions of the reactive load has been simulated by MATLAB software.Obviously, the results state the proper operation of the power control of wind energy converting system , improvement of the network power factor, and Reduction of harmonic current of network based on the proposed method.

Program THEK energy production units of average power and using thermal conversion of solar radiation

Science.gov (United States)

1978-01-01

General studies undertaken by the C.N.R.S. in the field of solar power plants have generated the problem of building energy production units in the medium range of electrical power, in the order of 100 kW. Among the possible solutions, the principle of the use of distributed heliothermal converters has been selected as being, with the current status of things, the most advantageous solution. This principle consists of obtaining the conversion of concentrated radiation into heat by using a series of heliothermal conversion modules scattered over the ground; the produced heat is collected by a heat-carrying fluid circulating inside a thermal loop leading to a device for both regulation and storage.

Photovoltaic power. Industries and market

International Nuclear Information System (INIS)

Muller, J.C.

2007-01-01

Photovoltaic conversion should become competitive with respect to other power generation sources before the second half of the 21. century. This article treats first of the different solar cell technologies (monocrystalline and polycrystalline silicon, thin film silicon, cadmium telluride-based materials, copper-indium selenide-based materials, multi-spectral cells, organic cells) with respect to their conversion efficiency, production and energy cost, and environmental impact. A second part describes the solar cells market, its growth with respect to the different applications (isolated sites, decentralized generation, power plants). A third part deals with the perspectives of photovoltaic conversion with respect to the advance in the development of new cell materials. (J.S.)

EDITORIAL: Selected papers from the 11th International Workshop on Micro and Nanotechnology for Power Generation and Energy Conversion Applications (PowerMEMS 2011) Selected papers from the 11th International Workshop on Micro and Nanotechnology for Power Generation and Energy Conversion Applications (PowerMEMS 2011)

Science.gov (United States)

Cho, Young-Ho

2012-09-01

This special section of Journal of Micromechanics and Microengineering features papers selected from the 11th International Workshop on Micro and Nanotechnology for Power Generation and Energy Conversion Applications (PowerMEMS 2011), held at Sejong Hotel in Seoul, Korea during 15-18 November 2011. Since the first PowerMEMS workshop held in Sendai, Japan in 2000, the workshop has developed as the premier forum for reporting research results in micro and nanotechnology for power generation, energy conversion, harvesting and processing applications, including in-depth technical issues on nanostructures and materials for small-scale high-density energy and thermal management. Potential PowerMEMS applications cover not only portable power devices for consumer electronics and remote sensors, but also micro engines, impulsive thrusters and fuel cells for systems ranging from the nanometer to the millimeter scale. The 2011 technical program consists of 1 plenary talk, 4 invited talks and 118 contributed presentations. The 48 oral and 70 poster presentations, selected by 27 Technical Program Committee Members from 131 submitted abstracts, have stimulated lively discussion maximizing the interaction between participants. Among them, this special section includes 9 papers covering micro-scale power generators, energy converters, harvesters, thrusters and thermal coolers. Finally, we are grateful to the members of the International Steering Committee, the Technical Program Committee, and the Local Organizing Committee for their efforts and contributions to PowerMEMS 2011. We also thank the two companies Samsung Electro-Mechanics and LG Elite for technical tour arrangements. Special thanks go to Dr Ian Forbes, the editorial staff of the Journal of Micromechanics and Microengineering, as well as to the staff of IOP Publishing for making this special section possible.

Photovoltaic and thermal energy conversion for solar powered satellites

Science.gov (United States)

Von Tiesenhausen, G. F.

1976-01-01

A summary is provided concerning the most important aspects of present investigations related to a use of solar power satellites (SPS) as a future source of terrestrial energy. General SPS characteristics are briefly considered, early work is reviewed, and a description of current investigations is presented. System options presently under study include a photovoltaic array, a thermionic system, and a closed Brayton cycle. Attention is given to system reference options, basic building blocks, questions of system analysis and engineering, photovoltaic conversion, and the utility interface. It is concluded that an SPS may be cost effective compared to terrestrial systems by 1995.

Biomass CHP Catalog of Technologies

Science.gov (United States)

This report reviews the technical and economic characterization of biomass resources, biomass preparation, energy conversion technologies, power production systems, and complete integrated CHP systems.

Power converter topologies for wind energy conversion systems: Integrated modeling, control strategy and performance simulation

Energy Technology Data Exchange (ETDEWEB)

Melicio, R.; Catalao, J.P.S. [Department of Electromechanical Engineering, University of Beira Interior, R. Fonte do Lameiro, 6201-001 Covilha (Portugal); Mendes, V.M.F. [Department of Electrical Engineering and Automation, Instituto Superior de Engenharia de Lisboa, R. Conselheiro Emidio Navarro, 1950-062 Lisbon (Portugal)

2010-10-15

This paper presents new integrated model for variable-speed wind energy conversion systems, considering a more accurate dynamic of the wind turbine, rotor, generator, power converter and filter. Pulse width modulation by space vector modulation associated with sliding mode is used for controlling the power converters. Also, power factor control is introduced at the output of the power converters. Comprehensive performance simulation studies are carried out with matrix, two-level and multilevel power converter topologies in order to adequately assert the system performance. Conclusions are duly drawn. (author)

Effective Methods of Nuclear Power Technology Transfer

International Nuclear Information System (INIS)

Shave, D. F.; Kent, G. F.; Giambusso, A.

1987-01-01

An effective technology transfer program is a necessary and significant step towards independence in nuclear power technology. Attaining success in the conduct of such a program is a result of a) the donor and recipient jointly understanding the fundamental concepts of the learning process, b) sharing a mutual philosophy involving a partnership relationship, c) joint and careful planning, d) rigorous adherence to proven project management techniques, and e) presence of adequate feedback to assure continuing success as the program proceeds. Several years ago, KEPCO President Park, Jung-KI presented a paper on technology in which he stated, 'Nuclear technology is an integration of many unit disciplines, and thus requires extensive investment and training in order to establish the base for efficient absorption of transferred technology.' This paper addresses President Park's observations by discussing the philosophy, approach, and mechanisms that are necessary to support an efficient and effective process of nuclear power technology transfer. All technical content and presentation methods discussed are based on a technology transfer program developed by Stone and Webster, as an Engineer/Constructor for nuclear power plants, and are designed and implemented to promote the primary program goal - the ability of the trainees and the organization to perform specific nuclear power related multi-discipline function independently and competitively

Innovative power conversion system for the French SFR prototype, ASTRID

International Nuclear Information System (INIS)

Cachon, L.; Biscarrat, C.; Morin, F.; Haubensack, D.; Rigal, E.; Moro, I.; Baque, F.; Madeleine, S.; Rodriguez, G.; Laffont, G.

2012-01-01

In the framework of the French Act of 28 June 2006 about nuclear materials and waste management, the prototype ASTRID (Advanced Sodium Technological Reactor for Industrial Demonstration), foreseen in operation by the 20's, will have to demonstrate not only the minor actinide transmutation capability, but also the progress made in Sodium Fast Reactor (SFR) technology on an industrial scale, by qualifying innovative options. Some of these options still require improvements, especially in the field of operability and safety. In fact, one of the main issues with the standard steam/water Power Conversion System (PCS) of SFR is the fast and energetic chemical reaction between water and sodium, which could occur in steam generators in case of tube failure. To manage the sodium/water reaction, one way consists in minimizing the impact of such event: hence studies are carried out on steam generator design, improvement of the physical knowledge of this phenomenon, development of numerical simulation to predict the reaction onset and consequences, and associated detection improvement. On the other hand, the other way consists in eliminating sodium/water reaction. In this frame, the CEA contribution to the feasibility evaluation of an alternative innovative PCS (replacing steam/water by 180 bar pressurised nitrogen) is focused on the following main topics: - The parametric study leading to nitrogen selection: the thermodynamic cycle efficiency optimisation on Brayton cycles is performed with several gases at different pressures. - The design of innovative compact heat exchangers for the gas loop: here the key points are the nuclear codification associated with inspection capability, the innovative welding process and the thermal-hydraulic and thermal-mechanic optimisations. After a general introduction of the ASTRID project, this paper presents in detail these different feasibility studies being led on the innovative gas PCS for an SFR. (authors)

All-optical multi-wavelength conversion with negative power penalty by a commercial SOA-MZI for WDM wavelength multicast

NARCIS (Netherlands)

Yan, N.; Jung, H.D.; Tafur Monroy, I.; Waardt, de H.; Koonen, A.M.J.

2007-01-01

WDM wavelength multicast is demonstrated by all-optical multi-wavelength conversion at 10 Gb/s using a commercial SOA-MZI. We report for the first time simultaneous one-to-four conversion with negative power penalty of 1.84 dB.

Technological implications of fusion power: requirements and status

International Nuclear Information System (INIS)

Steiner, D.

1978-01-01

The major technological requirements for fusion power, as implied by current conceptual designs of fusion power plants, are identified and assessed relative to the goals of existing technology programs. The focus of the discussion is on the tokamak magnetic confinement concept; however, key technological requirements of mirror magnetic confinement systems and of inertial confinement concepts will also be addressed. The required technology is examined on the basis of three general areas of concern: (a) the power balance, that is, the unique power handling requirements associated with the production of electrical power by fusion; (b) reactor design, focusing primarily on the requirements imposed by a tritium-based fuel cycle, thermal hydraulic considerations, and magnet systems; and (c) materials considerations, including radiation damage effects, neutron-induced activation, and resource limitations

History of electric power technological innovation in 2017

International Nuclear Information System (INIS)

Yamaguchi, Hiroshi; Okabe, Kazuhiko; Ichimura, Yasunori

2017-01-01

This is an overview of the electric power technology innovation of 12 electric power companies in 2016. Among them, this paper outlines the technological contents related to nuclear power of three major companies. TEPCO group applied a sealant from the outside to the back-up seal of reactor containment vessel that had deteriorated. It developed a good sealing system by combining with an improved sealant, and confirmed the effect at an experimental level. Regarding environmental restoration in Fukushima, TEPCO developed a personal dosimetry technology, environmental monitoring technology, and a technology to simulate radiation reduction amount after decontamination. Chubu Electric Power Company conducted researches on the applicability of the start-up range neutron monitor count rate prediction method related to fuel loading after a long-term shut-down of nuclear power generation, basic examination for practical use of laser decontamination, and possibility of tsunami prediction using satellite positioning information. With regard to the decommissioning measures of nuclear power plants, Japan Nuclear Power Electric Generation Co., Ltd. conducted studies on the decommissioning work of the Tokai Power Station, the safe dismantling method of the Tsuruga Power Station Unit 1 as decommissioning measures and fuel management, and the disposal method of radioactive contaminants. In the development of future reactor, this company conducted research on the development of fast breeder reactor system, etc. (A.O.)

10- to 30-kWe space power system using the uranium-zirconium hydride reactor and organic Rankine power conversion system

International Nuclear Information System (INIS)

Determan, W.R.; Bost, D.S.

1987-01-01

The UZrH reactor-ORC power system has been reviewed to determine its feasibility issues and characterize the system size, mass, and efficiency in the 10- to 30-kWe power range. The major component technologies required for this concept were reviewed to determine their technology status rating for early deployment of the system on near-term missions. Dynamic Isotope Power System (DIPS) technology is directly applicable to the UZrH reactor-ORC concept in the areas of power system reliability and survivability. The UZrH reactor-ORC concept provides a truly state-of-the-art system for use in future military and civilian space power programs. 9 references

Polymeric Materials for Conversion of Electromagnetic Waves from the Sun to Electric Power

Directory of Open Access Journals (Sweden)

SK Manirul Haque

2018-03-01

Full Text Available Solar photoelectric energy converted into electricity requires large surface areas with incident light and flexible materials to capture these light emissions. Currently, sunlight rays are converted to electrical energy using silicon polymeric material with efficiency up to 22%. The majority of the energy is lost during conversion due to an energy gap between sunlight photons and polymer energy transformation. This energy conversion also depends on the morphology of present polymeric materials. Therefore, it is very important to construct mechanisms of highest energy occupied molecular orbitals (HOMOs and the lowest energy unoccupied molecular orbitals (LUMOs to increase the efficiency of conversion. The organic and inorganic solar cells used as dyes can absorb more photons from sunlight and the energy gap will be less for better conversion of energy to electricity than the conventional solar cells. This paper provides an up-to-date review on the performance, characterization, and reliability of different composite polymeric materials for energy conversion. Specific attention has been given to organic solar cells because of their several advantages over others, such as their low-energy payback time, conversion efficiency and greenhouse emissions. Finally, this paper provides the recent progress on the application of both organic and inorganic solar cells for electric power generations together with several challenges that are currently faced.

Multi-megawatt power system trade study

Science.gov (United States)

Longhurst, Glen R.; Schnitzler, Bruce G.; Parks, Benjamin T.

2002-01-01

A concept study was undertaken to evaluate potential multi-megawatt power sources for nuclear electric propulsion. The nominal electric power requirement was set at 15 MWe with an assumed mission profile of 120 days at full power, 60 days in hot standby, and another 120 days of full power, repeated several times for 7 years of service. Two configurations examined were (1) a gas-cooled reactor based on the NERVA Derivative design, operating a closed cycle Brayton power conversion system; and (2) a molten metal-cooled reactor based on SP-100 technology, driving a boiling potassium Rankine power conversion system. This study considered the relative merits of these two systems, seeking to optimize the specific mass. Conclusions were that either concept appeared capable of reaching the specific mass goal of 3-5 kg/kWe estimated to be needed for this class of mission, though neither could be realized without substantial development in reactor fuels technology, thermal radiator mass and volume efficiency, and power conversion and distribution electronics and systems capable of operating at high temperatures. The gas-Brayton system showed a specific mass advantage (3.17 vs 6.43 kg/kWe for the baseline cases) under the set of assumptions used and eliminated the need to deal with two-phase working fluid flows in the microgravity environment of space. .

Powering the Space Exploration Initiative

International Nuclear Information System (INIS)

Bennett, G.L.

1991-01-01

The Space Exploration Initiative (SEI) establishes the long-term goal of returning to the Moon and then exploring Mars. One of the prerequisites of SEI is the Exploration Technology Program which includes program elements on space nuclear power and surface solar power. These program elements in turn build upon the ongoing NASA research and technology base program in space energy conversion. There is a wide range of missions in NASA's strategic planning and most would benefit from power sources with improved efficiency, lighter weight and reduced cost

Evaluation and optimization of a supercritical carbon dioxide power conversion cycle for nuclear applications

International Nuclear Information System (INIS)

Harvego, Edwin A.; McKellar, Michael G.

2011-01-01

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 (CO 2 ) is particularly attractive because it is capable of achieving relatively high power conversion cycle efficiencies in the temperature range between 550degC and 750degC. Therefore, it has the potential for use with any type of high-temperature nuclear reactor concept, assuming reactor core outlet temperatures of at least 550degC. The particular power cycle investigated in this paper is a supercritical CO 2 recompression Brayton Cycle. The CO 2 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; 550degC versus 750degC. However, the supercritical CO 2 recompression Brayton Cycle requires a high end operating pressure in the range of 20 MPa, which is considerably higher than the required helium Brayton cycle high end operating pressure of 7 MPa. This paper presents results of analyses performed using the UniSim process analyses software to evaluate the performance of the supercritical CO 2 recompression Brayton cycle for different reactor coolant outlet temperatures and mass flow rates. The UniSim model assumed a 600 MWt reactor power source, which provides heat to the power cycle at a maximum temperature of between 550degC and 850degC. Sensitivity calculations were also performed to determine the affect of reactor coolant mass flow rates for a reference reactor coolant outlet temperature of 750degC. The UniSim model used realistic component parameters and operating conditions to model the complete power conversion system. CO 2 properties were evaluated, and the operating range for the cycle was adjusted to take advantage of the rapidly changing conditions near the

Power Conversion Study for High Temperature Gas-Cooled Reactors

International Nuclear Information System (INIS)

Chang Oh; Richard Moore; Robert Barner

2005-01-01

The Idaho National Laboratory (INL) is investigating a Brayton cycle efficiency improvement on a high temperature gas-cooled reactor (HTGR) as part of Generation-IV nuclear engineering research initiative. There are some technical issues to be resolved before the selection of the final design of the high temperature gas cooled reactor, called as a Next Generation Nuclear Plant (NGNP), which is supposed to be built at the INEEL by year 2017. The technical issues are the selection of the working fluid, direct vs. indirect cycle, power cycle type, the optimized design in terms of a number of intercoolers, and others. In this paper, we investigated a number of working fluids for the power conversion loop, direct versus indirect cycle, the effect of intercoolers, and other thermal hydraulics issues. However, in this paper, we present part of the results we have obtained. HYSYS computer code was used along with a computer model developed using Visual Basic computer language

Military conversion and Science from a global perspective

International Nuclear Information System (INIS)

Proctor, J.

1994-01-01

The changes that begun in late 1980s in Europe and former Soviet Union have great impact upon political, economic and social conditions of most people in the world, meaning present state and future development of science. This paper deals with the problems of defense conversion and brain drain which provide a uniting global issue for learned societies, academies of science and organizations advancing technology around the world to maintain pressure on decision makers to raise science and technology in their scheme of priorities. Learned societies and academies both non-governmental and government supported have clear roles in defense conversion and related issues of brain drain. The challenge remains: to design and implement structures and processes for the modern world to deal with high technology, basic and applied science with the attendant great concentration of power and resources. Revised procedures for funding transitional structures and processes for sciences are expected to be recommended

Motor starting a Brayton cycle power conversion system using a static inverter

Science.gov (United States)

Curreri, J. S.; Edkin, R. A.; Kruchowy, R.

1973-01-01

The power conversion module of a 2- to 15-kWe Brayton engine was motor started using a three-phase, 400-hertz static inverter as the power source. Motor-static tests were conducted for initial gas loop pressures of 10, 14, and 17 N/sq cm (15, 20, and 25 psia) over a range of initial turbine inlet temperatures from 366 to 550 K (200 to 530 F). The data are presented to show the effects of temperature and pressure on the motor-start characteristics of the rotating unit. Electrical characteristics during motoring are also discussed.

On the Development of Fuel-Free Power Supply Sources on Pneumatic Energy Conversion Principles

Science.gov (United States)

Son, E. E.; Nikolaev, V. G.; Kudryashov, Yu. I.; Nikolaev, V. V.

2017-12-01

The article is devoted to the evaluation of capabilities and problems of creation of fuel-free power supply of isolated and autonomous Russian consumers of low (up to several hundreds kW) power based on the joint use of wind power plants and progressive systems of pneumatic accumulation and conversion of energy. The basic and functional schemes and component structure of the system prototype are developed and proposed, the evaluations of the expected technical and economic indicators of system are presented, and the ways of its further practical implementation are planned.

Research and development of methods and technologies for CO2 capture in fossil fuel power plants and storage in geological formations in the Czech Republic. Stage 5.4: Boiler with oxyfuel technology. Revision 0

International Nuclear Information System (INIS)

Dlouhy, Tomas

2011-12-01

This phase comprised a preliminary study of boiler design modification for the oxyfuel technology. The design was developed specifically for the Prunerov II power plant. It was defined as a reference boiler for combustion using air which was consequently modified for combustion with oxygen. Changes in the construction of boiler were designed and quantified using thermal conversion, which provided the necessary modification of the sizes of the fireplace and heating surfaces. An existing general mathematical model, modified for this specific task, was used for the thermal conversion calculations

Low-cost feedstock conversion to biodiesel via ultrasound technology

Energy Technology Data Exchange (ETDEWEB)

Babajide, O.; Petrik, L.; Amigun, B.; Ameer, F. [Environmental and Nano Science Research Group, Department of Chemistry, University of the Western Cape, Bellville, Cape Town 7535 (South Africa); Amigun, B. [Sustainable Energy Futures, Council for Scientific and Industrial Research (CSIR), Stellenbosch (South Africa)

2010-10-15

Biodiesel has attracted increasing interest and has proved to be a good substitute for fossil-based fuels due to its environmental advantages and availability from renewable resources such as refined and waste vegetable oils. Several studies have shown that biodiesel is a better fuel than the fossil-derived diesel in terms of engine performance, emissions reduction, lubricity and environmental benefits. The increasing popularity of biodiesel has generated great demand for its commercial production methods, which in turn calls for the development of technically and economically sound process technologies. This paper explores the applicability of ultrasound in the optimization of low-cost feedstock - in this case waste cooking oil - in the transesterification conversion to biodiesel. It was found that the conversion efficiency of the waste oil using ultrasound was higher than with the mechanical stirring method. The optimized variables of 6:1 methanol/oil ratio at a reaction temperature of 30 {sup o}C, a reaction time of 30 min and 0.75% KOH (wt/wt) catalyst concentration were obtained for the transesterification of the waste oil via the use of ultrasound. (authors)

Low-Cost Feedstock Conversion to Biodiesel via Ultrasound Technology

Energy Technology Data Exchange (ETDEWEB)

Babajide, Omotola [Environmental and Nano Science Research Group, Dept. of Chemistry, Univ. of the Western Cape, Bellville, Cape Town (South Africa); Petrik, Leslie [Environmental and Nano Science Research Group, Dept. of Chemistry, Univ. of the Western Cape, Bellville, Cape Town (South Africa); Amigun, Bamikole [Environmental and Nano Science Research Group, Dept. of Chemistry, Univ. of the Western Cape, Bellville, Cape Town (South Africa) and Sustainable Energy Futures, Council for Scientific and Industrial Research (CSIR), Stellenbosch (South Africa); Ameer, Faraouk [Environmental and Nano Science Research Group, Dept. of Chemistry, Univ. of the Western Cape, Bellville, Cape Town (South Africa)

2010-09-15

Biodiesel has attracted increasing interest and has proved to be a good substitute for fossil-based fuels due to its environmental advantages and availability from renewable resources such as refined and waste vegetable oils. Several studies have shown that biodiesel is a better fuel than the fossil-derived diesel in terms of engine performance, emissions reduction, lubricity and environmental benefits. The increasing popularity of biodiesel has generated great demand for its commercial production methods, which in turn calls for the development of technically and economically sound process technologies. This paper explores the applicability of ultrasound in the optimization of low-cost feedstock – in this case waste cooking oil – in the transesterification conversion to biodiesel. It was found that the conversion efficiency of the waste oil using ultrasound was higher than with the mechanical stirring method. The optimized variables of 6:1 methanol/oil ratio at a reaction temperature of 30 deg C and a reaction time of 30 min and 0.75% KOH (wt/wt) catalyst concentration was obtained for the transesterification of the waste oil via the use of ultrasound.

IEA Energy Technology Essentials: Nuclear Power

Energy Technology Data Exchange (ETDEWEB)

NONE

2007-03-15

The IEA Energy Technology Essentials series offers concise four-page updates on the different technologies for producing, transporting and using energy. Nuclear power is the topic covered in this edition.

Understanding Power Electronics and Electrical Machines in Multidisciplinary Wind Energy Conversion System Courses

Science.gov (United States)

Duran, M. J.; Barrero, F.; Pozo-Ruz, A.; Guzman, F.; Fernandez, J.; Guzman, H.

2013-01-01

Wind energy conversion systems (WECS) nowadays offer an extremely wide range of topologies, including various different types of electrical generators and power converters. Wind energy is also an application of great interest to students and with a huge potential for engineering employment. Making WECS the main center of interest when teaching…

Enhanced Power Conversion Efficiency of Perovskite Solar Cells with an Up-Conversion Material of Er3+-Yb3+-Li+ Tri-doped TiO2.

Science.gov (United States)

Zhang, Zhenlong; Qin, Jianqiang; Shi, Wenjia; Liu, Yanyan; Zhang, Yan; Liu, Yuefeng; Gao, Huiping; Mao, Yanli

2018-05-11

In this paper, Er 3+ -Yb 3+ -Li + tri-doped TiO 2 (UC-TiO 2 ) was prepared by an addition of Li + to Er 3+ -Yb 3+ co-doped TiO 2 . The UC-TiO 2 presented an enhanced up-conversion emission compared with Er 3+ -Yb 3+ co-doped TiO 2 . The UC-TiO 2 was applied to the perovskite solar cells. The power conversion efficiency (PCE) of the solar cells without UC-TiO 2 was 14.0%, while the PCE of the solar cells with UC-TiO 2 was increased to 16.5%, which presented an increase of 19%. The results suggested that UC-TiO 2 is an effective up-conversion material. And this study provided a route to expand the spectral absorption of perovskite solar cells from visible light to near-infrared using up-conversion materials.

Developmental Considerations on the Free-piston Stirling Power Convertor for Use in Space

Science.gov (United States)

Schreiber, Jeffrey G.

2007-01-01

Free-piston Stirling power conversion has been considered a candidate for radioisotope power systems for space for more than a decade. Prior to the free-piston Stirling architecture, systems were designed with kinematic Stirling engines with rotary alternators to convert heat to electricity. These systems were proposed with lightly loaded linkages to achieve the necessary life. When the free-piston configuration was initially proposed, it was thought to be attractive due to the relatively high conversion efficiency, acceptable mass, and the potential for long life and high reliability. These features have consistently been recognized by teams that have studied technology options for radioisotope power systems. Since free-piston Stirling power conversion was first considered for space power applications, there have been major advances in three general areas of development: demonstration of life and reliability, the success achieved by Stirling cryocoolers in flight, and the overall developmental maturity of the technology for both flight and terrestrial applications. Based on these advances, free-piston Stirling convertors are currently being developed for a number of terrestrial applications. They commonly operate with the power, efficiency, life, and reliability as intended, and much of the development now centers on system integration. This paper will summarize the accomplishments of free-piston Stirling power conversion technology over the past decade, review the status, and discuss the challenges that remain.

Power conversion and control methods for renewable energy sources

Science.gov (United States)

Yu, Dachuan

2005-07-01

In recent years, there has been an increase in the use of renewable energy due to the growing concern over the pollution caused by fossil-fuel-based energy. Renewable energy sources, such as photovoltaic (PV) and fuel cell, can be used to enhance the safety, reliability, sustainability, and transmission efficiency of a power system. This dissertation focuses on the power conversion and control for two major renewable-energy sources: PV and fuel cell. Firstly, a current-based, maximum power-point tracking (MPPT) algorithm is proposed for PV energy. An economical converter system using the above scheme for converting the output from PV panels into 60 Hz AC voltage is developed and built. Secondly, a novel circuit model for the Proton Exchange Membrane (PEM) fuel-cell stack that is useful in the design and analysis of fuel-cell-based power systems is proposed. This Pspice-based model uses elements available in the Pspice library with some modifications to represent both the static and dynamic responses of a PEM fuel-cell module. The accuracy of the model is verified by comparing the simulation and experimental results. Thirdly, a DSP-controlled three-phase induction-motor drive using constant voltage over frequency is built and can be used in a fuel-cell automobile. A hydrogen sensor is used in the drive to both sound an alarm and shut down the inverter trigger pulses through the DSP. Finally, a hybrid power system consisting of PV panels and fuel cell is proposed and built. In the proposed system, PV panels can supply most of the power when the sunlight is available, and the excess power required by the load is supplied by a fuel cell. Load sharing between a fuel cell (FC) and the PV panel is investigated by both simulation and experiments.

Power production with direct energy conversion

International Nuclear Information System (INIS)

Rochau, G.; Lipinski, R.; Polansky, G.; Seidel, D.; Slutz, S.; Morrow, C.; Anghaie, S.; Beller, D.; Brown, L.; Parish, T.

2001-01-01

The direct energy conversion (DEC) project has as its main goal the development of a direct energy conversion process suitable for commercial development. We define direct energy conversion as any fission process that returns usable energy without using an intermediate thermal process. During the first phase of study, nine different concepts were investigated and 3 were selected: 1) quasi-spherical magnetically insulated fission electrode cell, 2) fission fragment magnetic collimator, and 3) gaseous core reactor with MHD generator. Selection was based on efficiency and feasibility. The realization of their potential requires an investment in both technically and commercially oriented research. The DEC project has a process in place to take one of these concepts forward and to outline the road map for further development. (A.C.)

Power production with direct energy conversion

Energy Technology Data Exchange (ETDEWEB)

Rochau, G.; Lipinski, R.; Polansky, G.; Seidel, D.; Slutz, S. [Sandia National Labs., Albuquerque, NM (United States); Morrow, C. [Morrow Consulting, Albuquerque, NM (United States); Anghaie, S. [Florida Univ., Gainesville, FL (United States); Beller, D. [Los Alamos National Lab., NM (United States); Brown, L. [General Atomic Co., San Diego, CA (United States); Parish, T. [Texas A and M Univ., College Station, TX (United States). Dept. of Nuclear Engineering

2001-07-01

The direct energy conversion (DEC) project has as its main goal the development of a direct energy conversion process suitable for commercial development. We define direct energy conversion as any fission process that returns usable energy without using an intermediate thermal process. During the first phase of study, nine different concepts were investigated and 3 were selected: 1) quasi-spherical magnetically insulated fission electrode cell, 2) fission fragment magnetic collimator, and 3) gaseous core reactor with MHD generator. Selection was based on efficiency and feasibility. The realization of their potential requires an investment in both technically and commercially oriented research. The DEC project has a process in place to take one of these concepts forward and to outline the road map for further development. (A.C.)

Design for Reliability of Power Electronics for Grid-Connected Photovoltaic Systems

DEFF Research Database (Denmark)

Yang, Yongheng; Sangwongwanich, Ariya; Blaabjerg, Frede

2016-01-01

Power electronics is the enabling technology for optimizing energy harvesting from renewable systems like Photovoltaic (PV) and wind power systems, and also for interfacing grid-friendly energy systems. Advancements in the power semiconductor technology (e.g., wide band-gap devices) have pushed...... the conversion efficiency of power electronics to above 98%, where however te reliability of power electronics is becoming of high concern. Therefore, it is important to design for reliable power electronic systems to lower the risks of many failures during operation; otherwise will increase the cost...... for maintenance and reputation, thus affecting the cost of PV energy. Today's PV power conversion applications require the power electronic systems with low failure rates during a service life of 20 years or even more. To achieve so, it is vital to know the main life-limiting factors of power electronic systems...

Nuclear power strategy: requirements for technology

International Nuclear Information System (INIS)

Orlov, V.V.; Rachkov, V.I.

2001-01-01

The possible role of nuclear power in sustainable development demands answers to at least three questions: Is large-scale nuclear power essential to future development? - Is it feasible to have modern nuclear power transformed for large-scale deployment? - When will large-scale nuclear power be practically needed? The questions are analysed with the requirements to be fulfilled concerning present-day technologies

Progress of technological innovation on electric power in FY2014

International Nuclear Information System (INIS)

Nishikawa, Yoshikazu; Fujii, Yutaka; Sasagawa, Toshiro

2015-01-01

This paper overviews the technological development in FY2014 at Tokyo Electric Power Company, Chubu Electric Power Company, Hokuriku Electric Power Company, Shikoku Electric Power Company, and Electric Power Development Company. In this overview, further breakdown was made for the following departments of each company: nuclear power generation, thermal power generation, hydraulic power generation, power transmission, power distribution, transformation, research and development and technological development, and information and communication. In addition, this paper outlines the achievement of technological development at Japan Atomic Power Company, such as the technological development related to the existing power station, development of new technology, and the development of future reactor. Fukushima Daiichi Nuclear Power Station has developed an investigative system using a high altitude survey robot and a movable monitoring system. Hamaoka Nuclear Power Station examined the feasibility of state diagnostic technique based on multi-point analysis, and studied stress corrosion cracking at the newly established Nuclear Safety Research Laboratory. Shika Nuclear Power Station (Unit 1) applied a pipe stress improvement process by means of high frequency induction heating as a stress corrosion cracking countermeasure. Ikata Nuclear Power Station newly adopted high degree cross-linking cation resin, and high cracking strength anion resin as the primary resins. Oma Nuclear Power Station worked on the all reactor core utilization technology of MOX fuel. (A.O.)

Thermal Management of Power Semiconductor Packages - Matching Cooling Technologies with Packaging Technologies (Presentation)

Energy Technology Data Exchange (ETDEWEB)

Bennion, K.; Moreno, G.

2010-04-27

Heat removal for power semiconductor devices is critical for robust operation. Because there are different packaging options, different thermal management technologies, and a range of applications, there is a need for a methodology to match cooling technologies and package configurations to target applications. To meet this need, a methodology was developed to compare the sensitivity of cooling technologies on the overall package thermal performance over a range of power semiconductor packaging configurations. The results provide insight into the trade-offs associated with cooling technologies and package configurations. The approach provides a method for comparing new developments in power semiconductor packages and identifying potential thermal control technologies for the package. The results can help users select the appropriate combination of packaging configuration and cooling technology for the desired application.

High efficiency heat transport and power conversion system for cascade

International Nuclear Information System (INIS)

Maya, I.; Bourque, R.F.; Creedon, R.L.; Schultz, K.R.

1985-02-01

The Cascade ICF reactor features a flowing blanket of solid BeO and LiAlO 2 granules with very high temperature capability (up to approx. 2300 K). The authors present here the design of a high temperature granule transport and heat exchange system, and two options for high efficiency power conversion. The centrifugal-throw transport system uses the peripheral speed imparted to the granules by the rotating chamber to effect granule transport and requires no additional equipment. The heat exchanger design is a vacuum heat transfer concept utilizing gravity-induced flow of the granules over ceramic heat exchange surfaces. A reference Brayton power cycle is presented which achieves 55% net efficiency with 1300 K peak helium temperature. A modified Field steam cycle (a hybrid Rankine/Brayton cycle) is presented as an alternate which achieves 56% net efficiency

Economy and technology roles played by nuclear power

International Nuclear Information System (INIS)

Yamada, Eiji

1985-01-01

On the basis of the survey analysis made by Atomic Energy Commission on the roles in economy and technology played in the nuclear energy development and utilization, the following are described: economic roles in nuclear energy development and utilization (the present state of nuclear power industry in Japan and the economy effects); technological roles in the same (the present state of nuclear power technology in Japan and the technology effects). The economy effects in other areas are on higher level than in other industries etc. Then, in the technology effects, system technology and quality control in the nuclear power possess significant effects in other areas. While the nuclear energy development and utilization is important in Japan's energy security, it is contributing largely to the economy and society in Japan. (Mori, K.)

The feasibility of using conversational agent technology to improve problem-solving and coping skills of young adults with cancer

Directory of Open Access Journals (Sweden)

von Friederichs-Fitzwater M

2011-04-01

Full Text Available Marlene M von Friederichs-Fitzwater1, Frederick J Meyers21Division of Hematology/Oncology, Internal Medicine, 2School of Medicine, University of California Davis, Sacramento, CA, USAObjective: Young adults with cancer have unique psychosocial needs and often lack the problem-solving and coping skills for effective resolution. We conducted a study to clarify these needs and then developed and tested an educational intervention to coach young adults with cancer in problem-solving and coping skills using a new conversational agent technology that uses a multi-media format to simulate face-to-face encounters.Methods: We qualitatively assessed online focus groups and chat rooms with 45 young adults with cancer and used the results to develop and test an online 15-minute educational prototype using a new conversational agent technology with 49 young adults (18–35 years of age with cancer.Results: Young adults with cancer are most concerned about reproductive issues, emotional issues, communicating with healthcare providers, and the risks and benefits of treatments. The study participants found the I-COPE prototype to be useful, easy to use, and worth recommending to others. They wanted to have more video segments about the experiences of other young adults with cancer; more video segments of actual procedures and treatments; more Internet links to information and resources; and more opportunities to interact with the conversational agent.Conclusion: New conversational agent technology is useful in coaching problem-solving and coping skills to empower young adults with cancer.Practice implications: New conversational agent technology is a useful tool in patient education and skill development, particularly among young adults.Keywords: young adult cancer patients, conversational agent technology, problem-solving, coping, self-efficacy, survivorship

CSTI High Capacity Power

International Nuclear Information System (INIS)

Winter, J.M.

1989-01-01

The SP-100 program was established in 1983 by DOD, DOE, and NASA as a joint program to develop the technology necessary for space nuclear power systems for military and civil application. During FY-86 and 87, the NASA SP-100 Advanced Technology Program was devised to maintain the momentum of promising technology advancement efforts started during Phase 1 of SP-100 and to strengthen, in key areas, the chances for successful development and growth capability of space nuclear reactor power systems for future space applications. In FY-88, the Advanced Technology Program was incorporated into NASA's new Civil Space Technology Initiative (CSTI). The CSTI Program was established to provide the foundation for technology development in automation and robotics, information, propulsion, and power. The CSTI High Capacity Power Program builds on the technology efforts of the SP-100 program, incorporates the previous NASA SP-100 Advanced Technology project, and provides a bridge to NASA Project Pathfinder. The elements of CSTI High Capacity Power development include Conversion Systems, Thermal Management, Power Management, System Diagnostics, and Environmental Interactions. Technology advancement in all areas, including materials, is required to assure the high reliability and 7 to 10 year lifetime demanded for future space nuclear power systems. The overall program will develop and demonstrate the technology base required to provide a wide range of modular power systems as well as allowing mission independence from solar and orbital attitude requirements. Several recent advancements in CSTI High Capacity power development will be discussed

Canadian Experience in Nuclear Power Technology Transfer

International Nuclear Information System (INIS)

Boulton, J.

1987-01-01

Technology transfer has and will continue to play a major role in the development of nuclear power programs. From the early beginnings of the development of the peaceful uses of nuclear power by just a few nations in the mid-1940s there has been a considerable transfer of technology and today 34 countries have nuclear programs in various stages of development. Indeed, some of the major nuclear vendors achieves their present position through a process of technology transfer and subsequent development. Canada, one of the early leaders in the development of nuclear power, has experience with a wide range of programs bout within its own borders and with other countries. This paper briefly describes this experience and the lessons learned from Canada's involvement in the transfer of nuclear power technology. Nuclear technology is complex and diverse and yet it can be assimilated by a nation given a fire commitment of both suppliers and recipients of technology to achieve success. Canada has reaped large benefits from its nuclear program and we believe this has been instrumentally linked to the sharing of goals and opportunity for participation over extended periods of time by many interests within the Canadian infrastructure. While Canada has accumulated considerable expertise in nuclear technology transfer, we believe there is still much for US to learn. Achieving proficiency in any of the many kinds of nuclear related technologies will place a heavy burden on the financial and human resources of a nation. Care must be taken to plan carefully the total criteria which will assure national benefits in industrial and economic development. Above all, effective transfer of nuclear technology requires a long term commitment by both parties

High-flux/high-temperature solar thermal conversion: technology development and advanced applications

Directory of Open Access Journals (Sweden)

Romero Manuel

2016-01-01

Full Text Available Solar Thermal Power Plants have generated in the last 10 years a dynamic market for renewable energy industry and a pro-active networking within R&D community worldwide. By end 2015, there are about 5 GW installed in the world, most of them still concentrated in only two countries, Spain and the US, though a rapid process of globalization is taking place in the last few years and now ambitious market deployment is starting in countries like South Africa, Chile, Saudi Arabia, India, United Arab Emirates or Morocco. Prices for electricity produced by today's plants fill the range from 12 to 16 c€/kWh and they are capital intensive with investments above 4000 €/kW, depending on the number of hours of thermal storage. The urgent need to speed up the learning curve, by moving forward to LCOE below 10 c€/kWh and the promotion of sun-to-fuel applications, is driving the R&D programmes. Both, industry and R&D community are accelerating the transformation by approaching high-flux/high-temperature technologies and promoting the integration with high-efficiency conversion systems.

Solar power conversion system with directionally- and spectrally-selective properties based on a reflective cavity

Science.gov (United States)

Boriskina, Svetlana; Kraemer, Daniel; McEnaney, Kenneth; Weinstein, Lee A.; Chen, Gang

2018-03-13

Solar power conversion system. The system includes a cavity formed within an enclosure having highly specularly reflecting in the IR spectrum inside walls, the enclosure having an opening to receive solar radiation. An absorber is positioned within the cavity for receiving the solar radiation resulting in heating of the absorber structure. In a preferred embodiment, the system further contains an energy conversion and storage devices thermally-linked to the absorber by heat conduction, convection, far-field or near-field thermal radiation.

Revolution of Nuclear Power Plant Design Through Digital Technology

International Nuclear Information System (INIS)

Zhang, L.; Shi, J.; Chen, W.

2015-01-01

In the digital times, digital technology has penetrated into every industry. As the highest safety requirement standard, nuclear power industry needs digital technology more to breed high quality and efficiency. Digital power plant is derived from digital design and the digitisation of power plant transfer is an inevitable trend. This paper introduces the technical solutions and features of digital nuclear power plant construction by Shanghai Nuclear Engineering Research & Design Institute, points out the key points and technical difficulties that exist in the process of construction and can serve as references for further promoting construction of digital nuclear power plant. Digital technology is still flourishing. Although many problems will be encountered in construction, it is believed that digital technology will make nuclear power industry more safe, cost-effective and efficient. (author)

Global wind power potential: Physical and technological limits

International Nuclear Information System (INIS)

Castro, Carlos de; Mediavilla, Margarita; Miguel, Luis Javier; Frechoso, Fernando

2011-01-01

This paper is focused on a new methodology for the global assessment of wind power potential. Most of the previous works on the global assessment of the technological potential of wind power have used bottom-up methodologies (e.g. ). Economic, ecological and other assessments have been developed, based on these technological capacities. However, this paper tries to show that the reported regional and global technological potential are flawed because they do not conserve the energetic balance on Earth, violating the first principle of energy conservation (). We propose a top-down approach, such as that in , to evaluate the physical-geographical potential and, for the first time, to evaluate the global technological wind power potential, while acknowledging energy conservation. The results give roughly 1 TW for the top limit of the future electrical potential of wind energy. This value is much lower than previous estimates and even lower than economic and realizable potentials published for the mid-century (e.g. ). - Highlights: → Reported wind power potentials are flawed because they violate energy conservation. → For the first time, it is evaluated the technological wind power potential with a top-down approach. → Our results show 1 TWe for the limit of wind power energy, which is much lower than previous estimates.

Space power technology for the twenty-first century (SPT21)

International Nuclear Information System (INIS)

Borger, W.U.; Massie, L.D.

1988-01-01

During the spring and summer months of 1987, the Aero Propulsion Laboratory of the Air Force Wright Aeronautical Laboratories, Wright-Patterson AFB, Ohio in cooperation with the Air Force Space Technology Center at Kirtland AFB, New Mexico, undertook an initiative to develop a Strategic Plan for Space Power Technology Development. The initiative was called SPT21, Space Power Technology for the Twenty-First Century. The planning process involved the participation of other Government organizations (U.S. Army, Navy, DOE and NASA) along with major aerospace companies and universities. Following an SPT21 kickoff meeting on 28 May 1987, detailed strategic planning was accomplished through seven (7) Space Power Technology Discipline Workshops commencing in June 1987 and concluding in August 1987. Technology Discipline Workshops were conducted in the following areas: (1) Solar Thermal Dynamic Power Systems (2) Solar Photovoltaic Cells and Arrays (3) Thermal Management Technology (4) Energy Storage Technology (5) Nuclear Power Systems Technology (6) Power Conditioning, Distribution and Control and (7) Systems Technology/Advanced Concepts. This technical paper summarizes the planning process and describes the salient findings and conclusions of the workshops

Medium-Power Lead-Alloy Reactors: Missions for This Reactor Technology

International Nuclear Information System (INIS)

Todreas, Neil E.; MacDonald, Philip E.; Hejzlar, Pavel; Buongiorno, Jacopo; Loewen, Eric P.

2004-01-01

A multiyear project at the Idaho National Engineering and Environmental Laboratory and the Massachusetts Institute of Technology investigated the potential of medium-power lead-alloy-cooled technology to perform two missions: (1) the production of low-cost electricity and (2) the burning of actinides from light water reactor (LWR) spent fuel. The goal of achieving a high power level to enhance economic performance simultaneously with adoption of passive decay heat removal and modularity capabilities resulted in designs in the range of 600-800 MW(thermal), which we classify as a medium power level compared to the lower [∼100 MW(thermal)] and higher [2800 MW(thermal)] power ratings of other lead-alloy-cooled designs. The plant design that was developed shows promise of achieving all the Generation-IV goals for future nuclear energy systems: sustainable energy generation, low overnight capital cost, a very low likelihood and degree of core damage during any conceivable accident, and a proliferation-resistant fuel cycle. The reactor and fuel cycle designs that evolved to achieve these missions and goals resulted from study of the following key trade-offs: waste reduction versus reactor safety, waste reduction versus cost, and cost versus proliferation resistance. Secondary trade-offs that were also considered were monolithic versus modular design, active versus passive safety systems, forced versus natural circulation, alternative power conversion cycles, and lead versus lead-bismuth coolant.These studies led to a selection of a common modular design with forced convection cooling, passive decay heat removal, and a supercritical CO 2 power cycle for all our reactor concepts. However, the concepts adopt different core designs to optimize the achievement of the two missions. For the low-cost electricity production mission, a design approach based on fueling with low enriched uranium operating without costly reprocessing in a once-through cycle was pursued to achieve a

Sustainability assessment of renewable power and heat generation technologies

International Nuclear Information System (INIS)

Dombi, Mihály; Kuti, István; Balogh, Péter

2014-01-01

Rationalisation of consumption, more efficient energy usage and a new energy structure are needed to be achieved in order to shift the structure of energy system towards sustainability. The required energy system is among others characterised by intensive utilisation of renewable energy sources (RES). RES technologies have their own advantages and disadvantages. Nevertheless, for the strategic planning there is a great demand for the comparison of RES technologies. Furthermore, there are additional functions of RES utilisation expected beyond climate change mitigation, e.g. increment of employment, economic growth and rural development. The aim of the study was to reveal the most beneficial RES technologies with special respect to sustainability. Ten technologies of power generation and seven technologies of heat supply were examined in a multi-criteria sustainability assessment frame of seven attributes which were evaluated based on a choice experiment (CE) survey. According to experts the most important characteristics of RES utilisation technologies are land demand and social impacts i.e. increase in employment and local income generation. Concentrated solar power (CSP), hydropower and geothermal power plants are favourable technologies for power generation, while geothermal district heating, pellet-based non-grid heating and solar thermal heating can offer significant advantages in case of heat supply. - highlights: • We used choice experiment to estimate the weights of criteria for the sustainability assessment of RES technologies. • The most important attributes of RES technologies according to experts are land demand and social impacts. • Concentrated solar power (CSP), hydropower and geothermal power plants are advantageous technologies for power generation. • Geothermal district heating, pellet-based non-grid heating and solar thermal heating are favourable in case of heat supply

Self-Biased Differential Rectifier with Enhanced Dynamic Range for Wireless Powering

KAUST Repository

Ouda, Mahmoud H.

2016-08-29

A self-biased, cross-coupled, differential rectifier is proposed with enhanced power-conversion efficiency over an extended range of input power. A prototype is designed for UHF 433MHz RF power-harvesting applications and is implemented using 0.18μm CMOS technology. The proposed rectifier architecture is compared to the conventional cross-coupled rectifier. It demonstrates an improvement of more than 40% in the rectifier power conversion efficiency (PCE) and an input power range extension of more than 50% relative to the conventional crosscoupled rectifier. A sensitivity of -15.2dBm (30μW) input power for 1V output voltage and a peak power-conversion efficiency of 65% are achieved for a 50kω load. © 2004-2012 IEEE.

Candidate solar cell materials for photovoltaic conversion in a solar power satellite /SPS/

Science.gov (United States)

Glaser, P. E.; Almgren, D. W.

1978-01-01

In recognition of the obstacles to solar-generated baseload power on earth, proposals have been made to locate solar power satellites in geosynchronous earth orbit (GEO), where solar energy would be available 24 hours a day during most of the time of the year. In an SPS, the electricity produced by solar energy conversion will be fed to microwave generators forming part of a planar phase-array transmitting antenna. The antenna is designed to precisely direct a microwave beam of very low intensity to one or more receiving antennas at desired locations on earth. At the receiving antenna, the microwave energy will be safely and efficiently reconverted to electricity and then be transmitted to consumers. An SPS system will include a number of satellites in GEO. Attention is given to the photovoltaic option for solar energy conversion in GEO, solar cell requirements, the availability of materials, the implication of large production volumes, requirements for high-volume manufacture of solar cell arrays, and the effects of concentration ratio on solar cell array area.

Advanced power plant materials, design and technology

Energy Technology Data Exchange (ETDEWEB)

Roddy, D. (ed.) [Newcastle University (United Kingdom). Sir Joseph Swan Institute

2010-07-01

The book is a comprehensive reference on the state of the art of gas-fired and coal-fired power plants, their major components and performance improvement options. Selected chapters are: Integrated gasification combined cycle (IGCC) power plant design and technology by Y. Zhu, and H. C. Frey; Improving thermal cycle efficiency in advanced power plants: water and steam chemistry and materials performance by B. Dooley; Advanced carbon dioxide (CO{sub 2}) gas separation membrane development for power plants by A. Basile, F. Gallucci, and P. Morrone; Advanced flue gas cleaning systems for sulphur oxides (SOx), nitrogen oxides (NOx) and mercury emissions control in power plants by S. Miller and B.G. Miller; Advanced flue gas dedusting systems and filters for ash and particulate emissions control in power plants by B.G. Miller; Advanced sensors for combustion monitoring in power plants: towards smart high-density sensor networks by M. Yu and A.K. Gupta; Advanced monitoring and process control technology for coal-fired power plants by Y. Yan; Low-rank coal properties, upgrading and utilisation for improving the fuel flexibility of advanced power plants by T. Dlouhy; Development and integration of underground coal gasification (UCG) for improving the environmental impact of advanced power plants by M. Green; Development and application of carbon dioxide (CO{sub 2}) storage for improving the environmental impact of advanced power plants by B. McPherson; and Advanced technologies for syngas and hydrogen (H{sub 2}) production from fossil-fuel feedstocks in power plants by P. Chiesa.

Combined Heat and Power Systems for the Provision of Sustainable Energy from Biomass in Buildings

Directory of Open Access Journals (Sweden)

Ortwein Andreas

2016-01-01

Full Text Available Against the background of greenhouse gases causing climate change, combined heat and power (CHP systems fueled by biomass can efficiently supply energy with high flexibility. Such CHP systems will usually consist of one or more thermo-chemical conversion steps and at least one (the more or less separated electric power generation unit. Depending on the main products of the previous conversion steps (e.g. combustible gases or liquids, but also flue gases with sensible heat, different technologies are available for the final power conversion step. This includes steam cycles with steam turbines or engines and different working fluids (water, organic fluids, but also combustion based systems like gas turbines or gas engines. Further promising technologies include fuel cells with high electric efficiency. When integrating such CHP systems in buildings, there are different strategies, especially concerning electric power generation. While some concepts are focusing on base load production, others are regulated either by thermal or by electric power demand. The paper will give a systematic overview on the combination of thermo-chemical conversion of biomass and combined heat and power production technologies. The mentioned building integration strategies will be discussed, leading to conclusions for further research and development in that field.

Power Conversion Efficiency of Arylamine Organic Dyes for Dye-Sensitized Solar Cells (DSSCs) Explicit to Cobalt Electrolyte: Understanding the Structural Attributes Using a Direct QSPR Approach

OpenAIRE

Supratik Kar; Juganta K. Roy; Danuta Leszczynska; Jerzy Leszczynski

2016-01-01

Post silicon solar cell era involves light-absorbing dyes for dye-sensitized solar systems (DSSCs). Therefore, there is great interest in the design of competent organic dyes for DSSCs with high power conversion efficiency (PCE) to bypass some of the disadvantages of silicon-based solar cell technologies, such as high cost, heavy weight, limited silicon resources, and production methods that lead to high environmental pollution. The DSSC has the unique feature of a distance-dependent electron...

Automation technology in power plants

International Nuclear Information System (INIS)

Essen, E.R.

1995-01-01

In this article a summery of the current architecture of modern process control systems in power plants and future trends have been explained. The further development of process control systems for power plants is influenced both by the developments in component and software technologies as well as the increased requirements of the power plants. The convenient and low cost configuration facilities of new process control systems have now reached a significance which makes it easy for customers to decide to purchase. (A.B.)

Battery Energy Storage Technology for power systems-An overview

DEFF Research Database (Denmark)

Chandrashekhara, Divya K; Østergaard, Jacob

2009-01-01

the present status of battery energy storage technology and methods of assessing their economic viability and impact on power system operation. Further, a discussion on the role of battery storage systems of electric hybrid vehicles in power system storage technologies had been made. Finally, the paper...... suggests a likely future outlook for the battery technologies and the electric hybrid vehicles in the context of power system applications....

Emission Control Technologies for Thermal Power Plants

Science.gov (United States)

Nihalani, S. A.; Mishra, Y.; Juremalani, J.

2018-03-01

Coal thermal power plants are one of the primary sources of artificial air emissions, particularly in a country like India. Ministry of Environment and Forests has proposed draft regulation for emission standards in coal-fired power plants. This includes significant reduction in sulphur-dioxide, oxides of nitrogen, particulate matter and mercury emissions. The first step is to evaluate the technologies which represent the best selection for each power plant based on its configuration, fuel properties, performance requirements, and other site-specific factors. This paper will describe various technology options including: Flue Gas Desulfurization System, Spray Dryer Absorber (SDA), Circulating Dry Scrubber (CDS), Limestone-based Wet FGD, Low NOX burners, Selective Non Catalytic Reduction, Electrostatic Precipitator, Bag House Dust Collector, all of which have been evaluated and installed extensively to reduce SO2, NOx, PM and other emissions. Each control technology has its advantages and disadvantages. For each of the technologies considered, major features, potential operating and maintenance cost impacts, as well as key factors that contribute to the selection of one technology over another are discussed here.

Improving power conversion efficiency of perovskite solar cells by cooperative LSPR of gold-silver dual nanoparticles

Institute of Scientific and Technical Information of China (English)

Peng Liu; Cong-hua Zhou; Bing-chu Yang; Gang Liu; Run-sheng Wu; Chu-jun Zhang; Fang Wan; Shui-gen Li; Jun-liang Yang; Yong-li Gao

2017-01-01

Enhancing optical and electrical performances is effective in improving power conversion efficiency of photovoltaic devices.Here,gold and silver dual nanoparticles were imported and embedded in the hole transport layer of perovskite solar cells.Due to the cooperative localized surface plasmon resonance of these two kinds of metal nanostructures,light harvest of perovskite material layer and the electrical performance of device were improved,which finally upgraded short circuit current density by 10.0％,and helped to increase power conversion efficiency from 10.4％ to 11.6％ under AM 1.5G illumination with intensity of 100 mW/cm2.In addition,we explored the influence of silver and gold nanoparticles on charge carrier generation,dissociation,recombination,and transportation inside perovskite solar cells.

Technology Efficiency Study on Nuclear Power and Coal Power in Guangdong Province Based on DEA

International Nuclear Information System (INIS)

Yinong Li; Dong Wang

2006-01-01

Guangdong Province has taken the lead in embarking on nuclear power development to resolve its dire lack of primary resources. With the deepening of the on-going structural reform in the electric power sector in China, the market competition scheme is putting electricity generation enterprises under severe strain. Consequently, it is incumbent upon the nuclear power producers to steadily upgrade management, enhance technical capabilities, reduce cost and improve efficiency. At present, gradual application of such efficiency evaluation methodology has already commenced in some sectors in China including the electric power industry. The purpose of this paper is to use the Data Envelopment Analysis (DEA), which is a cutting-edge approach in the efficiency evaluation field - to study the technological efficiency between nuclear power and coal power in Guangdong Province. The DEA results demonstrate that, as far as Guangdong Province is concerned, the technological efficiency of nuclear power is higher than that of coal power in terms of Technological Efficiency (TE), Pure Technology Efficiency (PTE) and Scale Efficiency (SE). The reason is that nuclear power technology is advanced with a much higher equipment availability factor. Under the same scale, the generation output of nuclear power is far higher than that of equivalent coal power generation. With the environmental protection and sustainable development requirements taken into full account, nuclear power constitutes a clean, safe and highly-efficient energy form which should be extensively harnessed in Guangdong Province to fuel its future continuing economic growth. (authors)

A thermoelectric-conversion power supply system using a strontium heat source of high-level radioactive nuclear waste

International Nuclear Information System (INIS)

Chikazawa, Yoshitaka

2011-01-01

A thermoelectric-conversion power supply system with radioactive strontium in high-level radioactive waste has been proposed. A combination of Alkali Metal Thermo-Electric Conversion (AMTEC) and a strontium fluoride heat source can provide a compact and long-lived power supply system. A heat source design with strontium fluoride pin bundles with Hastelloy cladding and intermediate copper has been proposed. This design has taken heat transportation into consideration, and, in this regard, the feasibility has been confirmed by a three-dimensional thermal analysis using Star-CD code. This power supply system with an electric output of 1 MW can be arranged in a space of 50 m 2 and approximately 1.1 m height and can be operated for 15 years without refueling. This compact and long-lived power supply is suitable for powering sources for remote places and middle-sized ships. From the viewpoint of geological disposal of high-level waste, the proposed power supply system provides a financial base for strontium-cesium partitioning. That is, a combination of minor-actinide recycling and strontium-cesium partitioning can eliminate a large part of decay heat in high-level waste and thus can save much space for geological disposal. (author)

Closed Brayton cycle power conversion systems for nuclear reactors :

Energy Technology Data Exchange (ETDEWEB)

Wright, Steven A. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Lipinski, Ronald J. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Vernon, Milton E. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Sanchez, Travis [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

2006-04-01

This report describes the results of a Sandia National Laboratories internally funded research program to study the coupling of nuclear reactors to gas dynamic Brayton power conversion systems. The research focused on developing integrated dynamic system models, fabricating a 10-30 kWe closed loop Brayton cycle, and validating these models by operating the Brayton test-loop. The work tasks were performed in three major areas. First, the system equations and dynamic models for reactors and Closed Brayton Cycle (CBC) systems were developed and implemented in SIMULINKTM. Within this effort, both steady state and dynamic system models for all the components (turbines, compressors, reactors, ducting, alternators, heat exchangers, and space based radiators) were developed and assembled into complete systems for gas cooled reactors, liquid metal reactors, and electrically heated simulators. Various control modules that use proportional-integral-differential (PID) feedback loops for the reactor and the power-conversion shaft speed were also developed and implemented. The simulation code is called RPCSIM (Reactor Power and Control Simulator). In the second task an open cycle commercially available Capstone C30 micro-turbine power generator was modified to provide a small inexpensive closed Brayton cycle test loop called the Sandia Brayton test-Loop (SBL-30). The Capstone gas-turbine unit housing was modified to permit the attachment of an electrical heater and a water cooled chiller to form a closed loop. The Capstone turbine, compressor, and alternator were used without modification. The Capstone systems nominal operating point is 1150 K turbine inlet temperature at 96,000 rpm. The annular recuperator and portions of the Capstone control system (inverter) and starter system also were reused. The rotational speed of the turbo-machinery is controlled by adjusting the alternator load by using the electrical grid as the load bank. The SBL-30 test loop was operated at

Low-Cost Feedstock Conversion to Biodiesel via Ultrasound Technology

Directory of Open Access Journals (Sweden)

Farouk Ameer

2010-10-01

Full Text Available Biodiesel has attracted increasing interest and has proved to be a good substitute for fossil-based fuels due to its environmental advantages and availability from renewable resources such as refined and waste vegetable oils. Several studies have shown that biodiesel is a better fuel than the fossil-derived diesel in terms of engine performance, emissions reduction, lubricity and environmental benefits. The increasing popularity of biodiesel has generated great demand for its commercial production methods, which in turn calls for the development of technically and economically sound process technologies. This paper explores the applicability of ultrasound in the optimization of low-cost feedstock – in this case waste cooking oil – in the transesterification conversion to biodiesel. It was found that the conversion efficiency of the waste oil using ultrasound was higher than with the mechanical stirring method. The optimized variables of 6:1 methanol/oil ratio at a reaction temperature of 30 °C and a reaction time of 30 min and 0.75% KOH (wt/wt catalyst concentration was obtained for the transesterification of the waste oil via the use of ultrasound.

Technology in the policy process - controlling nuclear power

International Nuclear Information System (INIS)

Collingridge, D.

1983-01-01

The discussion in this book is built around nuclear power. The technology of nuclear power is shown to have features which make it inflexible in the sense that, once built, it is difficult and expensive to control. If inflexible technology is to be avoided, it is crucially important to be able to identify this failing at an early stage in the technology's development, before it has acquired an immunity to political control. Again, this problem is approached through the example of nuclear power, in particular the breeder reactor. The breeder is shown to be even less flexible than today's nuclear technology, because it will have higher capital costs, be of greater capital intensity, longer lead time, larger unit size, and will require more infrastructure for its operation. If this is developed, the breeder will be even less open to political control than the nuclear plant of the present. To put it another way, its planning will be even more open to errors and whatever errors are made will be even more costly than for existing nuclear technology. It is therefore even less of a socially and economically acceptable technology than today's nuclear power. (author)

Distributed Power-Generation Systems and Protection

DEFF Research Database (Denmark)

Blaabjerg, Frede; Yang, Yongheng; Yang, Dongsheng

2017-01-01

the challenging issues and, more importantly, to leverage the energy generation, stringent demands from both utility operators and consumers have been imposed on the DPGS. Furthermore, as the core of energy conversion, numerous power electronic converters employing advanced control techniques have been developed...... for the DPGS to consolidate the integration. In light of the above, this paper reviews the power-conversion and control technologies used for DPGSs. The impacts of the DPGS on the distributed grid are also examined, and more importantly, strategies for enhancing the connection and protection of the DPGS...

Fair Oaks Dairy Farms Cellulosic Ethanol Technology Review Summary

Energy Technology Data Exchange (ETDEWEB)

Andrew Wold; Robert Divers

2011-06-23

At Fair Oaks Dairy, dried manure solids (''DMS'') are currently used as a low value compost. United Power was engaged to evaluate the feasibility of processing these DMS into ethanol utilizing commercially available cellulosic biofuels conversion platforms. The Fair Oaks Dairy group is transitioning their traditional ''manure to methane'' mesophilic anaerobic digester platform to an integrated bio-refinery centered upon thermophilic digestion. Presently, the Digested Manure Solids (DMS) are used as a low value soil amendment (compost). United Power evaluated the feasibility of processing DMS into higher value ethanol utilizing commercially available cellulosic biofuels conversion platforms. DMS was analyzed and over 100 potential technology providers were reviewed and evaluated. DMS contains enough carbon to be suitable as a biomass feedstock for conversion into ethanol by gasification technology, or as part of a conversion process that would include combined heat and power. In the first process, 100% of the feedstock is converted into ethanol. In the second process, the feedstock is combusted to provide heat to generate electrical power supporting other processes. Of the 100 technology vendors evaluated, a short list of nine technology providers was developed. From this, two vendors were selected as finalists (one was an enzymatic platform and one was a gasification platform). Their selection was based upon the technical feasibility of their systems, engineering expertise, experience in commercial or pilot scale operations, the ability or willingness to integrate the system into the Fair Oaks Biorefinery, the know-how or experience in producing bio-ethanol, and a clear path to commercial development.

Current status of Chinese nuclear power industry and technology

International Nuclear Information System (INIS)

Kim, Hyun Min; Kim, Min; Jeong, Hee Jong; Hwang, Jeong Ki; Cho, Chung Hee

1996-10-01

China has been carrying out active international cooperation aiming to be a country where is to be an economical super power and an advanced country in nuclear power technology by the year early 2000, and China also has begun to be recognized as the largest potential market for the construction of nuclear power plants(NPPs) expecting to construct more than thirty nuclear power units by the year 2020. China has advanced technology in the basic nuclear science including liquid metal breeder reactor technology, nuclear material, medium and small size power plants, and isotope production technology, and also China has complete nuclear fuel cycle technology. However, China still has low NPP technology. Therefore, it is expected that China may have complementary cooperative relationship with China, it is expected that Korea may have an access to the advanced Chinese nuclear science technology, and may have a good opportunity to explore the Chinese market actively exporting excellent Korean NPP technology, and further may have a good position to the neighboring Asian countries' NPP markets. From this perspective, general Chinese social status, major nuclear R and D activity status, and correct NPP and technology status have been analyzed in this report, and this report is expected to be a useful resource for cooperating with China in future. 10 tabs., 6 figs., 16 refs. (Author)

Comparative analysis of the application of different Low Power Wide Area Network technologies in power grid

Science.gov (United States)

Wang, Hao; Sui, Hong; Liao, Xing; Li, Junhao

2018-03-01

Low Power Wide Area Network (LPWAN) technologies developed rapidly in recent years, but the application principle of different LPWAN technologies in power grid is still not clear. This paper gives a comparative analysis of two mainstream LPWAN technologies including NB-IoT and LoRa, and gives an application suggestion of these two LPWAN technologies, which can guide the planning and construction of LPWAN in power grid.

Integrated Micro-Power System (IMPS) Development at NASA Glenn Research Center

Science.gov (United States)

Wilt, David; Hepp, Aloysius; Moran, Matt; Jenkins, Phillip; Scheiman, David; Raffaelle, Ryne

2003-01-01

Glenn Research Center (GRC) has a long history of energy related technology developments for large space related power systems, including photovoltaics, thermo-mechanical energy conversion, electrochemical energy storage. mechanical energy storage, power management and distribution and power system design. Recently, many of these technologies have begun to be adapted for small, distributed power system applications or Integrated Micro-Power Systems (IMPS). This paper will describe the IMPS component and system demonstration efforts to date.

Modeling of the dynamics of wind to power conversion including high wind speed behavior

DEFF Research Database (Denmark)

Litong-Palima, Marisciel; Bjerge, Martin Huus; Cutululis, Nicolaos Antonio

2016-01-01

This paper proposes and validates an efficient, generic and computationally simple dynamic model for the conversion of the wind speed at hub height into the electrical power by a wind turbine. This proposed wind turbine model was developed as a first step to simulate wind power time series...... for power system studies. This paper focuses on describing and validating the single wind turbine model, and is therefore neither describing wind speed modeling nor aggregation of contributions from a whole wind farm or a power system area. The state-of-the-art is to use static power curves for the purpose...... of power system studies, but the idea of the proposed wind turbine model is to include the main dynamic effects in order to have a better representation of the fluctuations in the output power and of the fast power ramping especially because of high wind speed shutdowns of the wind turbine. The high wind...

Innovation on Energy Power Technology (1)

Science.gov (United States)

Nagano, Susumu; Kakishima, Masayoshi

After the last war, the output of single Steam Turbine Generator produced by the own technology in Japan returned to a prewar level. Electric power companies imported the large-capacity high efficiency Steam Turbine Generator from the foreign manufacturers in order to support the sudden increase of electric power demand. On the other hand, they decided to produce those in our own country to improve industrial technology. The domestic production of large-capacity 125MW Steam Turbine Generator overcome much difficulty and did much contribution for the later domestic technical progress.

EDITORIAL: Selected papers from the 10th International Workshop on Micro and Nanotechnology for Power Generation and Energy Conversion Applications (PowerMEMS 2010) Selected papers from the 10th International Workshop on Micro and Nanotechnology for Power Generation and Energy Conversion Applications (PowerMEMS 2010)

Science.gov (United States)

Reynaerts, Dominiek; Vullers, Ruud

2011-10-01

This special section of Journal of Micromechanics and Microengineering features papers selected from the 10th International Workshop on Micro and Nanotechnology for Power Generation and Energy Conversion Applications (PowerMEMS 2010). The workshop was organized in Leuven, Belgium from 30 November to 3 December 2010 by Katholieke Universiteit Leuven and the imec/Holst Centre. This was a special PowerMEMS Workshop, for several reasons. First of all, we celebrated the 10th anniversary of the workshop: the first PowerMEMS meeting was organized in Sendai, Japan in 2000. None of the organizers or participants of this first meeting could have predicted the impact of the workshop over the next decade. The second reason was that, for the first time, the conference organization spanned two countries: Belgium and the Netherlands. Thanks to the advances in information technology, teams from Katholieke Universiteit Leuven (Belgium) and the imec/Holst Centre in Eindhoven (the Netherlands) have been able to work together seamlessly as one team. The objective of the PowerMEMS Workshop is to stimulate innovation in micro and nanotechnology for power generation and energy conversion applications. Its scope ranges from integrated microelectromechanical systems (MEMS) for power generation, dissipation, harvesting, and management, to novel nanostructures and materials for energy-related applications. True to the objective of the PowerMEMSWorkshop, the 2010 technical program covered a broad range of energy related research, ranging from the nanometer to the millimeter scale, discussed in 5 invited and 52 oral presentations, and 112 posters. This special section includes 14 papers covering vibration energy harvesters, thermal applications and micro power systems. Finally, we wish to express sincere appreciation to the members of the International Steering Committee, the Technical Program Committee and last but not least the Local Organizing Committee. This special issue was edited in

European coal technology applied by the Danish power companies

Energy Technology Data Exchange (ETDEWEB)

Frydenberg, B. [Elsamprojekt A/S, Fredericia (Denmark)

1996-12-31

The development of coal-fired power plants has shown remarkable improvements with regard to efficiency and cleaner technology, and as coal remains the most important fuel for electric power production, it is important to make use of this technological development to reduce CO{sub 2} emissions. Of the three available technologies: Integrated Coal Gasification and Combined Cycle, Fluid Bed Combustion and Pulverised Coal with Ultra Supercritical Steam Data, the technology chosen by I/S ELSAM is the PC-USC with power production efficiencies growing from 45% to 50%. 5 figs., 1 tab.

Product information representation for feature conversion and implementation of group technology automated coding

Science.gov (United States)

Medland, A. J.; Zhu, Guowang; Gao, Jian; Sun, Jian

1996-03-01

Feature conversion, also called feature transformation and feature mapping, is defined as the process of converting features from one view of an object to another view of the object. In a relatively simple implementation, for each application the design features are automatically converted into features specific for that application. All modifications have to be made via the design features. This is the approach that has attracted most attention until now. In the ideal situation, however, conversions directly from application views to the design view, and to other applications views, are also possible. In this paper, some difficulties faced in feature conversion are discussed. A new representation scheme of feature-based parts models has been proposed for the purpose of one-way feature conversion. The parts models consist of five different levels of abstraction, extending from an assembly level and its attributes, single parts and their attributes, single features and their attributes, one containing the geometric reference element and finally one for detailed geometry. One implementation of feature conversion for rotational components within GT (Group Technology) has already been undertaken using an automated coding procedure operating on a design-feature database. This database has been generated by a feature-based design system, and the GT coding scheme used in this paper is a specific scheme created for a textile machine manufacturing plant. Such feature conversion techniques presented here are only in their early stages of development and further research is underway.

Quantum frequency conversion with ultra-broadband tuning in a Raman memory

Science.gov (United States)

Bustard, Philip J.; England, Duncan G.; Heshami, Khabat; Kupchak, Connor; Sussman, Benjamin J.

2017-05-01

Quantum frequency conversion is a powerful tool for the construction of hybrid quantum photonic technologies. Raman quantum memories are a promising method of conversion due to their broad bandwidths. Here we demonstrate frequency conversion of THz-bandwidth, fs-duration photons at the single-photon level using a Raman quantum memory based on the rotational levels of hydrogen molecules. We shift photons from 765 nm to wavelengths spanning from 673 to 590 nm—an absolute shift of up to 116 THz. We measure total conversion efficiencies of up to 10% and a maximum signal-to-noise ratio of 4.0(1):1, giving an expected conditional fidelity of 0.75, which exceeds the classical threshold of 2/3. Thermal noise could be eliminated by cooling with liquid nitrogen, giving noiseless conversion with wide tunability in the visible and infrared.

Nuclear power technologies for application in developing countries

International Nuclear Information System (INIS)

Zrodnikov, A.V.

2000-01-01

The tremendous social and political changes which have occurred during the recent decade in the former USSR made it possible to launch the process of commercialization of defense-related technologies in Russia. The so-called dual-use technologies are meant to be initially developed by the state for defense needs, but having a high commercial potential as well. To date, the process of such technology transfer from the state sector to a private one has been limited primarily by insufficient progress of the national private sector. Essentially, the main economic problem still remains the attraction of private capital for the promotion of dual-use technologies to the point at where they acquire commercially viable. A large number of advanced technologies are waiting to be commercialized. The report presented considers the prospects of civil use of some technologies related to the nuclear power area: space nuclear power systems, nuclear powered submarines and rector-pumped lasers. (author)

Analog-to-digital conversion

CERN Document Server

Pelgrom, Marcel

2017-01-01

This textbook is appropriate for use in graduate-level curricula in analog-to-digital conversion, as well as for practicing engineers in need of a state-of-the-art reference on data converters. It discusses various analog-to-digital conversion principles, including sampling, quantization, reference generation, nyquist architectures and sigma-delta modulation. This book presents an overview of the state of the art in this field and focuses on issues of optimizing accuracy and speed, while reducing the power level. This new, third edition emphasizes novel calibration concepts, the specific requirements of new systems, the consequences of 22-nm technology and the need for a more statistical approach to accuracy. Pedagogical enhancements to this edition include additional, new exercises, solved examples to introduce all key, new concepts and warnings, remarks and hints, from a practitioner’s perspective, wherever appropriate. Considerable background information and practical tips, from designing a PCB, to lay-o...

Analog-to-digital conversion

CERN Document Server

Pelgrom, Marcel J. M

2013-01-01

This textbook is appropriate for use in graduate-level curricula in analog to digital conversion, as well as for practicing engineers in need of a state-of-the-art reference on data converters.  It discusses various analog-to-digital conversion principles, including sampling, quantization, reference generation, nyquist architectures and sigma-delta modulation.  This book presents an overview of the state-of-the-art in this field and focuses on issues of optimizing accuracy and speed, while reducing the power level. This new, second edition emphasizes novel calibration concepts, the specific requirements of new systems, the consequences of 45-nm technology and the need for a more statistical approach to accuracy.  Pedagogical enhancements to this edition include more than twice the exercises available in the first edition, solved examples to introduce all key, new concepts and warnings, remarks and hints, from a practitioner’s perspective, wherever appropriate.  Considerable background information and pr...

Novel high efficient speed sensorless controller for maximum power extraction from wind energy conversion systems

International Nuclear Information System (INIS)

Fathabadi, Hassan

2016-01-01

Highlights: • Novel sensorless MPPT technique without drawbacks of other sensor/sensorless methods. • Tracking the actual MPP of WECSs, no tracking the MPP of their wind turbines. • Actually extracting the highest output power from WECSs. • Novel MPPT technique having the MPPT efficiency more than 98.5% for WECSs. • Novel MPPT technique having short convergence time for WECSs. - Abstract: In this study, a novel high accurate sensorless maximum power point tracking (MPPT) method is proposed. The technique tracks the actual maximum power point of a wind energy conversion system (WECS) at which maximum output power is extracted from the system, not the maximum power point of its wind turbine at which maximum mechanical power is obtained from the turbine, so it actually extracts the highest output power from the system. The technique only uses input voltage and current of the converter used in the system, and neither needs any speed sensors (anemometer and tachometer) nor has the drawbacks of other sensor/sensorless based MPPT methods. The technique has been implemented as a MPPT controller by constructing a WECS. Theoretical results, the technique performance, and its advantages are validated by presenting real experimental results. The real static-dynamic response of the MPPT controller is experimentally obtained that verifies the proposed MPPT technique high accurately extracts the highest instant power from wind energy conversion systems with the MPPT efficiency of more than 98.5% and a short convergence time that is only 25 s for the constructed system having a total inertia and friction coefficient of 3.93 kg m 2 and 0.014 N m s, respectively.

Desulfurization technologies for flue gases from power stations, technological and financial characteristics

International Nuclear Information System (INIS)

Naumoski, Koce

1997-01-01

Harms on life environment, caused by aero pollution, for the last decades enforced fast development of technologies for filtration of gases that come from thermal power plants and other objects. SO 2 , that appear as one of outputs of fossil fuels combustion, and also processing of sulphide ore, is a main component of acid rains. Acid rains represent one of the most risky factors, responsible for dryne of woods and changing of flora and fauna on land and in water. Starting from 1931 year when on the thermal power plant BATTERSEA STATION, property of London Power, first scrubbers were monnted for filtration of flue gases of SO 2 , and up till today, many procedures are developed for desulfurization of flue gases. For easier coping with numerous technologies for desulfurization , various classifications were made. By state of aggregation of the absorption agent , the technologies for desulfurization of gases are divided in wet , semidry and dry procedures. Wet procedures are technologies with highness rate of desulfurization of 90-95 % and most flexible of the quality of fuel whose flue gases are filtered. Presently they have high price of 90-220 $/kw installed power. According to American sources, their price at the world market is forecasted that till 2000 year will reach price of 100 $/kw. Dry technologies for desulfurization of flue gases are last technologies. The rate of desulfurization is 50-60 % and its prise is 76 -113 $/kw. Their negative side is high variable costs 250 - 388 $/ ton SO 2 (at wet procedures variable costs 76 - 157 $/ton SO 2 ). Semidry technologies by financial and technological characteristics are wet and dry procedures. (Author)

2015 Plan. Project 4: electric power supply, technologies, cost and availability. Sub-project forest biomass. Plano 2015. Projeto 4: oferta de energia eletrica, tecnologia, custos e disponibilidades. Subprojeto biomassa florestal

Energy Technology Data Exchange (ETDEWEB)

1993-07-01

The potential and the costs of forest biomass utilization for electric power generation in Brazil are evaluated, including a discussion of the technologies and the forecasts in fuel production area (forests management) and in electric power conversion and generation areas. The socio-economics and environmental aspects referring to wood utilization as energetic resource are also described. (C.G.C.).

Current matching using CdSe quantum dots to enhance the power conversion efficiency of InGaP/GaAs/Ge tandem solar cells.

Science.gov (United States)

Lee, Ya-Ju; Yao, Yung-Chi; Tsai, Meng-Tsan; Liu, An-Fan; Yang, Min-De; Lai, Jiun-Tsuen

2013-11-04

A III-V multi-junction tandem solar cell is the most efficient photovoltaic structure that offers an extremely high power conversion efficiency. Current mismatching between each subcell of the device, however, is a significant challenge that causes the experimental value of the power conversion efficiency to deviate from the theoretical value. In this work, we explore a promising strategy using CdSe quantum dots (QDs) to enhance the photocurrent of the limited subcell to match with those of the other subcells and to enhance the power conversion efficiency of InGaP/GaAs/Ge tandem solar cells. The underlying mechanism of the enhancement can be attributed to the QD's unique capacity for photon conversion that tailors the incident spectrum of solar light; the enhanced efficiency of the device is therefore strongly dependent on the QD's dimensions. As a result, by appropriately selecting and spreading 7 mg/mL of CdSe QDs with diameters of 4.2 nm upon the InGaP/GaAs/Ge solar cell, the power conversion efficiency shows an enhancement of 10.39% compared to the cell's counterpart without integrating CdSe QDs.

Preventive maintenance technology for nuclear power stations

International Nuclear Information System (INIS)

Miyazawa, Tatsuo

1992-01-01

With the increase of the number of nuclear power plants in operation and the number of years of operation, the improvement of reliability and the continuation of safe operation have become more important, and the expectation for preventive maintenance technology has also heightened. The maintenance of Japanese nuclear power plants is based on the time schedule maintenance mainly by the regular inspection carried out every year, but the monitoring of the conditions of various machinery and equipment in operation has been performed widely. In this report, the present state of checkup and inspection technologies and the monitoring and diagnostic technologies for operational condition, which are the key technologies of preventive maintenance, are described. As the checkup and inspection technologies, ultrasonic flow detection technology, phased array technology, Amplituden und Laufzeit Orts Kurven method and X-ray CT, and as the monitoring and diagnostic technologies for operational condition, the diagnosis support system for BWR plants 'PLADIS', those for rotary machines, those for turbogenerators, those for solenoid valves, the mechanization of patrol works and the systematizing technology are reported. (K.I.)