WorldWideScience

Sample records for compressed air storage

  1. Compressed air energy storage system

    Science.gov (United States)

    Ahrens, Frederick W.; Kartsounes, George T.

    1981-01-01

    An internal combustion reciprocating engine is operable as a compressor during slack demand periods utilizing excess power from a power grid to charge air into an air storage reservoir and as an expander during peak demand periods to feed power into the power grid utilizing air obtained from the air storage reservoir together with combustible fuel. Preferably the internal combustion reciprocating engine is operated at high pressure and a low pressure turbine and compressor are also employed for air compression and power generation.

  2. Seneca Compressed Air Energy Storage (CAES) Project

    Energy Technology Data Exchange (ETDEWEB)

    None

    2012-11-30

    This document provides specifications for the process air compressor for a compressed air storage project, requests a budgetary quote, and provides supporting information, including compressor data, site specific data, water analysis, and Seneca CAES value drivers.

  3. Efficiency of Compressed Air Energy Storage

    DEFF Research Database (Denmark)

    Elmegaard, Brian; Brix, Wiebke

    2011-01-01

    The simplest type of a Compressed Air Energy Storage (CAES) facility would be an adiabatic process consisting only of a compressor, a storage and a turbine, compressing air into a container when storing and expanding when producing. This type of CAES would be adiabatic and would if the machines...... were reversible have a storage efficiency of 100%. However, due to the specific capacity of the storage and the construction materials the air is cooled during and after compression in practice, making the CAES process diabatic. The cooling involves exergy losses and thus lowers the efficiency...... of the storage significantly. The efficiency of CAES as an electricity storage may be defined in several ways, we discuss these and find that the exergetic efficiency of compression, storage and production together determine the efficiency of CAES. In the paper we find that the efficiency of the practical CAES...

  4. Adiabatic liquid piston compressed air energy storage

    Energy Technology Data Exchange (ETDEWEB)

    Petersen, Tage [Danish Technological Institute, Aarhus (Denmark); Elmegaard, B. [Technical Univ. of Denmark. DTU Mechanical Engineering, Kgs. Lyngby (Denmark); Schroeder Pedersen, A. [Technical Univ. of Denmark. DTU Energy Conversion, Risoe Campus, Roskilde (Denmark)

    2013-01-15

    This project investigates the potential of a Compressed Air Energy Storage system (CAES system). CAES systems are used to store mechanical energy in the form of compressed air. The systems use electricity to drive the compressor at times of low electricity demand with the purpose of converting the mechanical energy into electricity at times of high electricity demand. Two such systems are currently in operation; one in Germany (Huntorf) and one in the USA (Macintosh, Alabama). In both cases, an underground cavern is used as a pressure vessel for the storage of the compressed air. Both systems are in the range of 100 MW electrical power output with several hours of production stored as compressed air. In this range, enormous volumes are required, which make underground caverns the only economical way to design the pressure vessel. Both systems use axial turbine compressors to compress air when charging the system. The compression leads to a significant increase in temperature, and the heat generated is dumped into the ambient. This energy loss results in a low efficiency of the system, and when expanding the air, the expansion leads to a temperature drop reducing the mechanical output of the expansion turbines. To overcome this, fuel is burned to heat up the air prior to expansion. The fuel consumption causes a significant cost for the storage. Several suggestions have been made to store compression heat for later use during expansion and thereby avoid the use of fuel (so called Adiabatic CAES units), but no such units are in operation at present. The CAES system investigated in this project uses a different approach to avoid compression heat loss. The system uses a pre-compressed pressure vessel full of air. A liquid is pumped into the bottom of the vessel when charging and the same liquid is withdrawn through a turbine when discharging. In this case, the liquid works effectively as a piston compressing the gas in the vessel, hence the name &apos

  5. Compressed Air Energy Storage in Denmark

    DEFF Research Database (Denmark)

    Salgi, Georges Garabeth; Lund, Henrik

    2006-01-01

    is analysed with regard to the Danish energy system. In Denmark, wind power supplies 20% of the electricity demand and 50% is produced by combined heat and power (CHP). The operation of CAES requires high electricity price volatility. However, in the Nordic region, large hydro capacities have so far kept......Compressed air energy storage system (CAES) is a technology which can be used for integrating more fluctuating renewable energy sources into the electricity supply system. On a utility scale, CAES has a high feasibility potential compared to other storage technologies. Here, the technology...

  6. University of Arizona Compressed Air Energy Storage

    Energy Technology Data Exchange (ETDEWEB)

    Simmons, Joseph [Univ. of Arizona, Tucson, AZ (United States); Muralidharan, Krishna [Univ. of Arizona, Tucson, AZ (United States)

    2012-12-31

    Boiled down to its essentials, the grant’s purpose was to develop and demonstrate the viability of compressed air energy storage (CAES) for use in renewable energy development. While everyone agrees that energy storage is the key component to enable widespread adoption of renewable energy sources, the development of a viable scalable technology has been missing. The Department of Energy has focused on expanded battery research and improved forecasting, and the utilities have deployed renewable energy resources only to the extent of satisfying Renewable Portfolio Standards. The lack of dispatchability of solar and wind-based electricity generation has drastically increased the cost of operation with these components. It is now clear that energy storage coupled with accurate solar and wind forecasting make up the only combination that can succeed in dispatchable renewable energy resources. Conventional batteries scale linearly in size, so the price becomes a barrier for large systems. Flow batteries scale sub-linearly and promise to be useful if their performance can be shown to provide sufficient support for solar and wind-base electricity generation resources. Compressed air energy storage provides the most desirable answer in terms of scalability and performance in all areas except efficiency. With the support of the DOE, Tucson Electric Power and Science Foundation Arizona, the Arizona Research Institute for Solar Energy (AzRISE) at the University of Arizona has had the opportunity to investigate CAES as a potential energy storage resource.

  7. Seneca Compressed Air Energy Storage (CAES) Project

    Energy Technology Data Exchange (ETDEWEB)

    None, None

    2012-11-30

    This report provides a review and an analysis of potential environmental justice areas that could be affected by the New York State Electric & Gas (NYSEG) compress air energy storage (CAES) project and identifies existing environmental burden conditions on the area and evaluates additional burden of any significant adverse environmental impact. The review assesses the socioeconomic and demographic conditions of the area surrounding the proposed CAES facility in Schuyler County, New York. Schuyler County is one of 62 counties in New York. Schuyler County’s 2010 population of 18,343 makes it one of the least populated counties in the State (U.S. Census Bureau, 2010). This report was prepared for WorleyParsons by ERM and describes the study area investigated, methods and criteria used to evaluate this area, and the findings and conclusions from the evaluation.

  8. Seneca Compressed Air Energy Storage (CAES) Project

    Energy Technology Data Exchange (ETDEWEB)

    None, None

    2012-11-30

    Compressed Air Energy Storage (CAES) is a hybrid energy storage and generation concept that has many potential benefits especially in a location with increasing percentages of intermittent wind energy generation. The objectives of the NYSEG Seneca CAES Project included: for Phase 1, development of a Front End Engineering Design for a 130MW to 210 MW utility-owned facility including capital costs; project financials based on the engineering design and forecasts of energy market revenues; design of the salt cavern to be used for air storage; draft environmental permit filings; and draft NYISO interconnection filing; for Phase 2, objectives included plant construction with a target in-service date of mid-2016; and for Phase 3, objectives included commercial demonstration, testing, and two-years of performance reporting. This Final Report is presented now at the end of Phase 1 because NYSEG has concluded that the economics of the project are not favorable for development in the current economic environment in New York State. The proposed site is located in NYSEG’s service territory in the Town of Reading, New York, at the southern end of Seneca Lake, in New York State’s Finger Lakes region. The landowner of the proposed site is Inergy, a company that owns the salt solution mining facility at this property. Inergy would have developed a new air storage cavern facility to be designed for NYSEG specifically for the Seneca CAES project. A large volume, natural gas storage facility owned and operated by Inergy is also located near this site and would have provided a source of high pressure pipeline quality natural gas for use in the CAES plant. The site has an electrical take-away capability of 210 MW via two NYSEG 115 kV circuits located approximately one half mile from the plant site. Cooling tower make-up water would have been supplied from Seneca Lake. NYSEG’s engineering consultant WorleyParsons Group thoroughly evaluated three CAES designs and concluded that any

  9. Economic Modeling of Compressed Air Energy Storage

    Directory of Open Access Journals (Sweden)

    Rui Bo

    2013-04-01

    Full Text Available Due to the variable nature of wind resources, the increasing penetration level of wind power will have a significant impact on the operation and planning of the electric power system. Energy storage systems are considered an effective way to compensate for the variability of wind generation. This paper presents a detailed production cost simulation model to evaluate the economic value of compressed air energy storage (CAES in systems with large-scale wind power generation. The co-optimization of energy and ancillary services markets is implemented in order to analyze the impacts of CAES, not only on energy supply, but also on system operating reserves. Both hourly and 5-minute simulations are considered to capture the economic performance of CAES in the day-ahead (DA and real-time (RT markets. The generalized network flow formulation is used to model the characteristics of CAES in detail. The proposed model is applied on a modified IEEE 24-bus reliability test system. The numerical example shows that besides the economic benefits gained through energy arbitrage in the DA market, CAES can also generate significant profits by providing reserves, compensating for wind forecast errors and intra-hour fluctuation, and participating in the RT market.

  10. Adiabatic Liquid Piston Compressed Air Energy Storage

    DEFF Research Database (Denmark)

    Petersen, Tage; Elmegaard, Brian; Pedersen, Allan Schrøder

    the system. The compression leads to a significant increase in temperature, and the heat generated is dumped into the ambient. This energy loss results in a low efficiency of the system, and when expanding the air, the expansion leads to a temperature drop reducing the mechanical output of the expansion......), but no such units are in operation at present. The CAES system investigated in this project uses a different approach to avoid compression heat loss. The system uses a pre-compressed pressure vessel full of air. A liquid is pumped into the bottom of the vessel when charging and the same liquid is withdrawn through......-CAES system is significantly higher than existing CAES systems due to a low or nearly absent compression heat loss. Furthermore, pumps/turbines, which use a liquid as a medium, are more efficient than air/gas compressors/turbines. In addition, the demand for fuel during expansion does not occur. •The energy...

  11. Energy storage by compressed air. [using windpowered pumps

    Science.gov (United States)

    Szego, G. C.

    1973-01-01

    The feasibility of windpower energy storage by compressed air is considered. The system is comprised of a compressor, a motor, and a pump turbine to store air in caverns or aquifiers. It is proposed that storage of several days worth of compressed air up to 650 pounds per square inch can be used to push the aquifier up closer to the container dome and thus initiate piston action by simply compressing air more and more. More energy can be put into it by pressure increase or pushing back the water in the aquifier. This storage system concept has reheat flexibility and lowest cost effectiveness.

  12. Economics of compressed air energy storage employing thermal energy storage

    Energy Technology Data Exchange (ETDEWEB)

    Schulte, S.C.; Reilly, R.W.

    1979-11-01

    The approach taken in this study is to adopt system design and capital cost estimates from three independent CAES studies (eight total designs) and, by supplying a common set of fuel/energy costs and economic assumptions in conjunction with a common methodology, to arrive at a series of levelized energy costs over the system's lifetime. In addition, some analyses are provided to gauge the sensitivity of these levelized energy costs to fuel and compression energy costs and to system capacity factors. The systems chosen for comparison are of four generic types: conventional CAES, hybrid CAES, adiabatic CAES, and an advanced-design gas turbine (GT). In conventional CAES systems the heat of compression generated during the storage operation is rejected to the environment, and later, during the energy-generation phase, turbine fuel must be burned to reheat the compressed air. In the hybrid systems some of the heat of compression is stored and reapplied later during the generation phase, thereby reducing turbine fuel requirements. The adiabatic systems store adequate thermal energy to eliminate the need for turbine fuel entirely. The gas turbine is included within the report for comparison purposes; it is an advanced-design turbine, one that is expected to be available by 1985.

  13. Use of compressed-air storage systems; Einsatz von Druckluftspeichersystemen

    Energy Technology Data Exchange (ETDEWEB)

    Cyphely, I.; Rufer, A.; Brueckmann, Ph.; Menhardt, W.; Reller, A.

    2004-07-01

    This final report issued by the Swiss Federal Office of Energy (SFOE) looks at the use of compressed air as a means of storing energy. Historical aspects are listed and compressed-air storage as an alternative to current ideas that use electrolysis and hydrogen storage is discussed. The storage efficiency advantages of compressed-air storage is stressed and the possibilities it offers for compensating the stochastic nature of electricity production from renewable energy sources are discussed. The so-called BOP (Battery with Oil-hydraulics and Pneumatics) principle for the storage of electricity is discussed and its function is described. The advantages offered by such a system are listed and the development focus necessary is discussed.

  14. Economic and technical feasibility study of compressed air storage

    Energy Technology Data Exchange (ETDEWEB)

    1976-03-01

    The results of a study of the economic and technical feasibility of compressed air energy storage (CAES) are presented. The study, which concentrated primarily on the application of underground air storage with combustion turbines, consisted of two phases. In the first phase a general assessment of the technical alternatives, economic characteristics and the institutional constraints associated with underground storage of compressed air for utility peaking application was carried out. The goal of this assessment was to identify potential barrier problems and to define the incentive for the implementation of compressed air storage. In the second phase, the general conclusions of the assessment were tested by carrying out the conceptual design of a CAES plant at two specific sites, and a program of further work indicated by the assessment study was formulated. The conceptual design of a CAES plant employing storage in an aquifer and that of a plant employing storage in a conventionally excavated cavern employing a water leg to maintain constant pressure are shown. Recommendations for further work, as well as directions of future turbo-machinery development, are made. It is concluded that compressed air storage is technically feasible for off-peak energy storage, and, depending on site conditions, CAES plants may be favored over simple cycle turbine plants to meet peak demands. (LCL)

  15. Legal and regulatory issues affecting compressed air energy storage

    Energy Technology Data Exchange (ETDEWEB)

    Hendrickson, P.L.

    1981-07-01

    Several regulatory and legal issues that can potentially affect implementation of a compressed air energy storage (CAES) system are discussed. This technology involves the compression of air using base load electric power for storage in an underground storage medium. The air is subsequently released and allowed to pass through a turbine to generate electricity during periods of peak demand. The storage media considered most feasible are a mined hard rock cavern, a solution-mined cavern in a salt deposit, and a porous geologic formation (normally an aquifer) of suitable structure. The issues are discussed in four categories: regulatory issues common to most CAES facilities regardless of storage medium, regulatory issues applicable to particular CAES reservoir media, issues related to possible liability from CAES operations, and issues related to acquisition of appropriate property rights for CAES implementation. The focus is on selected federal regulation. Lesser attention is given to state and local regulation. (WHK)

  16. A new compressed air energy storage refrigeration system

    International Nuclear Information System (INIS)

    Wang Shenglong; Chen Guangming; Fang Ming; Wang Qin

    2006-01-01

    In this study, a new compressed air energy storage (CAES) refrigeration system is proposed for electrical power load shifting application. It is a combination of a gas refrigeration cycle and a vapor compression refrigeration cycle. Thermodynamic calculations are conducted to investigate the performance of this system. Economic analysis is performed to study the operating cost of the system, and comparison is made with a vapor compression refrigeration system and an ice storage refrigeration system. The results indicate that the CAES refrigeration system has the advantages of simple structure, high efficiency and low operating cost

  17. Air ejector augmented compressed air energy storage system

    Science.gov (United States)

    Ahrens, F.W.; Kartsounes, G.T.

    Energy is stored in slack demand periods by charging a plurality of underground reservoirs with air to the same peak storage pressure, during peak demand periods throttling the air from one storage reservoir into a gas turbine system at a constant inlet pressure until the air presure in the reservoir falls to said constant inlet pressure, thereupon permitting air in a second reservoir to flow into said gas turbine system while drawing air from the first reservoir through a variable geometry air ejector and adjusting said variable geometry air ejector, said air flow being essentially at the constant inlet pressure of the gas turbine system.

  18. Trigenerative micro compressed air energy storage: Concept and thermodynamic assessment

    International Nuclear Information System (INIS)

    Facci, Andrea L.; Sánchez, David; Jannelli, Elio; Ubertini, Stefano

    2015-01-01

    Highlights: • The trigenerative-CAES concept is introduced. • The thermodynamic feasibility of the trigenerative-CAES is assessed. • The effects of the relevant parameter on the system performances are dissected. • Technological issues on the trigenerative-CAES are highlighted. - Abstract: Energy storage is a cutting edge front for renewable and sustainable energy research. In fact, a massive exploitation of intermittent renewable sources, such as wind and sun, requires the introduction of effective mechanical energy storage systems. In this paper we introduce the concept of a trigenerative energy storage based on a compressed air system. The plant in study is a simplified design of the adiabatic compressed air energy storage and accumulates mechanical and thermal (both hot and cold) energy at the same time. We envisage the possibility to realize a relatively small size trigenerative compressed air energy storage to be placed close to the energy demand, according to the distributed generation paradigm. Here, we describe the plant concept and we identify all the relevant parameters influencing its thermodynamic behavior. Their effects are dissected through an accurate thermodynamic model. The most relevant technological issues, such as the guidelines for a proper choice of the compressor, expander and heat exchangers are also addressed. Our results show that T-CAES may have an interesting potential as a distributed system that combines electricity storage with heat and cooling energy production. We also show that the performances are significantly influenced by some operating and design parameters, whose feasibility in real applications must be considered.

  19. Thermal reservoir sizing for adiabatic compressed air energy storage

    Energy Technology Data Exchange (ETDEWEB)

    Kere, Amelie; Goetz, Vincent; Py, Xavier; Olives, Regis; Sadiki, Najim [Perpignan Univ. (France). PROMES CNRS UPR 8521; Mercier-Allart, Eric [EDF R et D, Chatou (France)

    2012-07-01

    Despite the operation of the two existing industrial facilities to McIntosh (Alabama), and for more than thirty years, Huntorf (Germany), electricity storage in the form of compressed air in underground cavern (CAES) has not seen the development that was expected in the 80s. The efficiency of this form of storage was with the first generation CAES, less than 50%. The evolving context technique can significantly alter this situation. The new generation so-called Adiabatic CAES (A-CAES) is to retrieve the heat produced by the compression via thermal storage, thus eliminating the necessity of gas to burn and would allow consideration efficiency overall energy of the order of 70%. To date, there is no existing installation of A-CAES. Many studies describe the principal and the general working mode of storage systems by adiabatic compression of air. So, efficiencies of different configurations of adiabatic compression process were analyzed. The aim of this paper is to simulate and analyze the performances of a thermal storage reservoir integrated in the system and adapted to the working conditions of a CAES.

  20. Compressed air energy storage technology program. Annual report for 1979

    Energy Technology Data Exchange (ETDEWEB)

    Loscutoff, W.V.

    1980-06-01

    The objectives of the Compressed Air Energy Storage (CAES) program are to establish stability criteria for large underground reservoirs in salt domes, hard rock, and porous rock used for air storage in utility applications, and to develop second-generation CAES technologies that have minimal or no dependence on petroleum fuels. During the year reported reports have been issued on field studies on CAES on aquifers and in salt, stability, and design criteria for CAES and for pumped hydro-storage caverns, laboratory studies of CAES in porous rock reservoris have continued. Research has continued on combined CAES/Thermal Energy Storage, CAES/Solar systems, coal-fired fluidized bed combustors for CAES, and two-reservoir advanced CAES concepts. (LCL)

  1. Optimal design of compressed air energy storage systems

    Energy Technology Data Exchange (ETDEWEB)

    Ahrens, F. W.; Sharma, A.; Ragsdell, K. M.

    1979-01-01

    Compressed air energy storage (CAES) power systems are currently being considered by various electric utilities for load-leveling applications. Models of CAES systems which employ natural underground aquifer formations, and present an optimal design methodology which demonstrates their economic viability are developed. This approach is based upon a decomposition of the CAES plant and utility grid system into three partially-decoupled subsystems. Numerical results are given for a plant employing the Media, Illinois Galesville aquifer formation.

  2. Geothermally Coupled Well-Based Compressed Air Energy Storage

    Energy Technology Data Exchange (ETDEWEB)

    Davidson, C L [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Bearden, Mark D [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Horner, Jacob A [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Appriou, Delphine [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); McGrail, B Peter [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2015-12-01

    Previous work by McGrail et al. (2013, 2015) has evaluated the possibility of pairing compressed air energy storage with geothermal resources in lieu of a fossil-fired power generation component, and suggests that such applications may be cost competitive where geology is favorable to siting both the geothermal and CAES components of such a system. Those studies also note that the collocation of subsurface resources that meet both sets of requirements are difficult to find in areas that also offer infrastructure and near- to mid-term market demand for energy storage. This study examines a novel application for the compressed air storage portion of the project by evaluating the potential to store compressed air in disused wells by amending well casings to serve as subsurface pressure vessels. Because the wells themselves would function in lieu of a geologic storage reservoir for the CAES element of the project, siting could focus on locations with suitable geothermal resources, as long as there was also existing wellfield infrastructure that could be repurposed for air storage. Existing wellfields abound in the United States, and with current low energy prices, many recently productive fields are now shut in. Should energy prices remain stagnant, these idle fields will be prime candidates for decommissioning unless they can be transitioned to other uses, such as redevelopment for energy storage. In addition to the nation’s ubiquitous oil and gas fields, geothermal fields, because of their phased production lifetimes, also may offer many abandoned wellbores that could be used for other purposes, often near currently productive geothermal resources. These existing fields offer an opportunity to decrease exploration and development uncertainty by leveraging data developed during prior field characterization, drilling, and production. They may also offer lower-cost deployment options for hybrid geothermal systems via redevelopment of existing well-field infrastructure

  3. Geothermally Coupled Well-Based Compressed Air Energy Storage

    Energy Technology Data Exchange (ETDEWEB)

    Davidson, Casie L. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Bearden, Mark D. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Horner, Jacob A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Cabe, James E. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Appriou, Delphine [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); McGrail, B. Peter [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2015-12-20

    Previous work by McGrail et al. (2013, 2015) has evaluated the possibility of pairing compressed air energy storage with geothermal resources in lieu of a fossil-fired power generation component, and suggests that such applications may be cost competitive where geology is favorable to siting both the geothermal and CAES components of such a system. Those studies also note that the collocation of subsurface resources that meet both sets of requirements are difficult to find in areas that also offer infrastructure and near- to mid-term market demand for energy storage. This study examines a novel application for the compressed air storage portion of the project by evaluating the potential to store compressed air in disused wells by amending well casings to serve as subsurface pressure vessels. Because the wells themselves would function in lieu of a geologic storage reservoir for the CAES element of the project, siting could focus on locations with suitable geothermal resources, as long as there was also existing wellfield infrastructure that could be repurposed for air storage. Existing wellfields abound in the United States, and with current low energy prices, many recently productive fields are now shut in. Should energy prices remain stagnant, these idle fields will be prime candidates for decommissioning unless they can be transitioned to other uses, such as redevelopment for energy storage. In addition to the nation’s ubiquitous oil and gas fields, geothermal fields, because of their phased production lifetimes, also may offer many abandoned wellbores that could be used for other purposes, often near currently productive geothermal resources. These existing fields offer an opportunity to decrease exploration and development uncertainty by leveraging data developed during prior field characterization, drilling, and production. They may also offer lower-cost deployment options for hybrid geothermal systems via redevelopment of existing well-field infrastructure

  4. Saline Cavern Adiabatic Compressed Air Energy Storage Using Sand as Heat Storage Material

    Directory of Open Access Journals (Sweden)

    Martin Haemmerle

    2017-03-01

    Full Text Available Adiabatic compressed air energy storage systems offer large energy storage capacities and power outputs beyond 100MWel. Salt production in Austria produces large caverns which are able to hold pressure up to 100 bar, thus providing low cost pressurized air storage reservoirs for adiabatic compressed air energy storage plants. In this paper the results of a feasibility study is presented, which was financed by the Austrian Research Promotion Agency, with the objective to determine the adiabatic compressed air energy storage potential of Austria’s salt caverns. The study contains designs of realisable plants with capacities between 10 and 50 MWel, applying a high temperature energy storage system currently developed at the Institute for Energy Systems and Thermodynamics in Vienna. It could be shown that the overall storage potential of Austria’s salt caverns exceeds a total of 4GWhel in the year 2030 and, assuming an adequate performance of the heat exchanger, that a 10MWel adiabatic compressed air energy storage plant in Upper Austria is currently feasible using state of the art thermal turbomachinery which is able to provide a compressor discharge temperature of 400 °C.

  5. Compressed air energy storage technology program. Annual report for 1980

    Energy Technology Data Exchange (ETDEWEB)

    Kannberg, L.D.

    1981-06-01

    All of the major research funded under the Compressed Air Energy Storage Technology Program during the period March 1980 to March 1981 is described. This annual report is divided into two segments: Reservoir Stability Studies and Second-Generation Concepts Studies. The first represents research performed to establish stability criteria for CAES reservoirs while the second reports progress on research performed on second-generation CAES concepts. The report consists of project reports authored by research engineers and scientists from PNL and numerous subcontractors including universities, architect-engineering, and other private firms.

  6. Researches on the CAES (Compressed Air Energy Storage) system

    Energy Technology Data Exchange (ETDEWEB)

    Shin Hee Soon; Kang, Sang Soo; Kwon, Kwang Soo [Korea Institute of Geology Mining and Materials, Taejon (Korea)] [and others

    1998-12-01

    CAES which is called as a compressed air energy storage was firstly developed at Huntorf, German in 1978. The capacity of that system was 290 MW, and it can be treated as a first commercial power plant. CAES has a lot of merits, such as saving the unit price of power generation, averaging the peak demand, improvement of maintenance, enlarging the benefit of dynamic use. According to the literature survey, the unlined rock cavern should be proposed to be a reasonable storing style as a method of compressed air storage in Korea. In this study, the most important techniques were evaluated through the investigation of the foreign construction case studies, especially on the unlined rock caverns in hard rock mass. We decided the hill of the Korea Institute of Geology, Mining and materials as CAES site. If we construct the underground spaces in this site, the demand for electricity nearby Taejon should be considered. So we could determine the capacity of the power plant as a 350 MW. This capacity needs a underground space of 200,000 m{sup 3}, and we can conclude 4 parallel tunnels through the numerical studies. Design parameters were achieved from 300 m depth boring job and image processing job. Moreover the techniques for determination of joint characteristics from the images could be obtained. Blasting pattern was designed on the underground spaces, and automatic gas control system and thermomechanical characteristics on caverns were also studied. (author). 51 refs., 79 tabs., 114 figs.

  7. Claw-pole Synchronous Generator for Compressed Air Energy Storage

    Directory of Open Access Journals (Sweden)

    PAVEL Valentina

    2013-05-01

    Full Text Available This paper presents a claw-poles generator for compressed air energy storage systems. It is presented the structure of such a system used for compensating of the intermittency of a small wind energy system. For equipping of this system it is chosen the permanent magnet claw pole synchronous generator obtained by using ring NdFeB permanentmagnets instead of excitation coil. In such a way the complexity of the scheme is reduced and the generator become maintenance free. The new magnetic flux density in the air-gap is calculated by magneticreluctance method and by FEM method and the results are compared with measured values in the old and new generator.

  8. Performance of a hydraulic air compressor for use in compressed air energy storage power systems

    Energy Technology Data Exchange (ETDEWEB)

    Berghmans, J. A.; Ahrens, F. W.

    1978-01-01

    A fluid mechanical analysis of a hydraulic air compression system for Compressed Air Energy Storage (CAES) application is presented. With this compression concept, air is charged into an underground reservoir, for later use in power generation, by entraining bubbles into a downward flow of water from a surface reservoir. Upon releasing the air in the underground reservoir, the water is pumped back to the surface. The analytical model delineated is used to predict the hydraulic compressor performance characteristics (pumping power, pump head, compression efficiency) as a function of water flow rate and system geometrical parameters. The results indicate that, although large water pumps are needed, efficiencies as high as 90% (relative to ideal isothermal compression) can be expected. This should result in lower compression power than for conventional compressor systems, while eliminating the need for the usual intercoolers and aftercooler.

  9. Corrosion of well casings in compressed air energy storage environments

    Energy Technology Data Exchange (ETDEWEB)

    Elmore, R.P.; Stottlemyre, J.A.

    1980-10-01

    The goal of this study was to determine corrosive effects of compressed air energy storage (CAES) environments on several well casing materials to aid in material selections. A literature search on corrosion behavior of well casing material in similar environments revealed that corrosion rates of 0.20 to 0.25 mm/y might be expected. This information was employed in designing the laboratory study. Unstressed electrically isolate samples of various carbon steels were autoclaved at varying humidities, temperatures, and exposure durations to simulate anticipated environments in the well bore during CAES operation. All compressed air tests were run at 12.1 MPa. Temperatures varied from 323/sup 0/K to 573/sup 0/K, and humidity varied from 100% to completely dry air. The effects of salts in the humidified air were also studied. Results indicated that typical well casings of carbon steel as used in oil, gas, and water production wells adequately withstand the anticipated CAES reservoir environment. An acceptable corrosion rate arrived at by these laboratory simulations was between 0.0015 and 0.15 mm/y. Corrosion was caused by metal oxidation that formed a protective scale of iron oxide. Higher temperatures, humidity rates, or salinity content of the humid air increased corrosion. Corrosion also increased on a metal coupon in contact with a sandstone sample, possibly due to crevice corrosion. For each of these factors either singularly or collectively, the increased corrosion rates were still acceptable with the maximum measured at 0.15 mm/y. When coupons were reused in an identical test, the corrosion rates increased beyond the anticipated values that had been determined by extrapolation from one-time runs. Fine cracking of the protective scale probably occurred due to thermal variations, resulting in increased corrosion rates and a greater potential for particulates, which could plug the reservoir.

  10. Economic analysis of using above ground gas storage devices for compressed air energy storage system

    Science.gov (United States)

    Liu, Jinchao; Zhang, Xinjing; Xu, Yujie; Chen, Zongyan; Chen, Haisheng; Tan, Chunqing

    2014-12-01

    Above ground gas storage devices for compressed air energy storage (CAES) have three types: air storage tanks, gas cylinders, and gas storage pipelines. A cost model of these gas storage devices is established on the basis of whole life cycle cost (LCC) analysis. The optimum parameters of the three types are determined by calculating the theoretical metallic raw material consumption of these three devices and considering the difficulties in manufacture and the influence of gas storage device number. The LCCs of the three types are comprehensively analyzed and compared. The result reveal that the cost of the gas storage pipeline type is lower than that of the other two types. This study may serve as a reference for designing large-scale CAES systems.

  11. Assessment of market potential of compressed air energy storage systems

    Science.gov (United States)

    Boyd, D. W.; Buckley, O. E.; Clark, C. E., Jr.

    1983-12-01

    This report describes an assessment of potential roles that EPRI might take to facilitate the commercial acceptance of compressed air energy storage (CAES) systems. The assessment is based on (1) detailed analyses of the market potential of utility storage technologies, (2) interviews with representatives of key participants in the CAES market, and (3) a decision analysis synthesizing much of the information about market and technology status. The results indicate a large potential market for CAES systems if the overall business environment for utilities improves. In addition, it appears that EPRI can have a valuable incremental impact in ensuring that utilities realize the potential of CAES by (1) continuing an aggressive information dissemination and technology transfer program, (2) working to ensure the success of the first United States CAES installation at Soyland Power Cooperative, (3) developing planning methods to allow utilities to evaluate CAES and other storage options more effectively and more realistically, and (4) supporting R and D to resolve residual uncertainties in first-generation CAES cost and performance characteristics. Previously announced in STAR as N83-25121

  12. Evaluation of thermal energy storage materials for advanced compressed air energy storage systems

    Energy Technology Data Exchange (ETDEWEB)

    Zaloudek, F.R.; Wheeler, K.R.; Marksberry, L.

    1983-03-01

    Advanced Compressed-Air Energy Storage (ACAS) plants have the near-term potential to reduce the fuel consumption of compressed-air plants from 33 to 100%, depending upon their design. Fuel is saved by storing some or all of the heat of compression as sensible heat which is subsequently used to reheat the compressed air prior to expansion in the turbine generator. The thermal storage media required for this application must be low cost and durable. The objective of this project was to screen thermal store materials based on their thermal cycle durability, particulate formation and corrosion resistant characteristics. The materials investigated were iron oxide pellets, Denstone pebbles, cast-iron balls, and Dresser basalt rock. The study specifically addressed the problems of particle formation and thermal ratcheting of the materials during thermal cycling and the chemical attack on the materials by the high temperature and moist environment in an ACAS heat storage bed. The results indicate that from the durability standpoint Denstone, cast iron containing 27% or more chromium, and crushed Dresser basalt would possibly stand up to ACAS conditions. If costs are considered in addition to durability and performance, the crushed Dresser basalt would probably be the most desirable heat storage material for adiabatic and hybrid ACAS plants, and more in-depth longer term thermal cycling and materials testing of Dresser basalt is recommended. Also recommended is the redesign and costing analysis of both the hybrid and adiabatic ACAS facilities based upon the use of Dresser basalt as the thermal store material.

  13. Energy Efficiency Analysis of Discharge Modes of an Adiabatic Compressed Air Energy Storage System

    OpenAIRE

    Shane D. Inder; Mehrdad Khamooshi

    2017-01-01

    Efficient energy storage is a crucial factor in facilitating the uptake of renewable energy resources. Among the many options available for energy storage systems required to balance imbalanced supply and demand cycles, compressed air energy storage (CAES) is a proven technology in grid-scale applications. This paper reviews the current state of micro scale CAES technology and describes a micro-scale advanced adiabatic CAES (A-CAES) system, where heat generated during compression is stored fo...

  14. Exergy and exergoeconomic analysis of a Compressed Air Energy Storage combined with a district energy system

    International Nuclear Information System (INIS)

    Bagdanavicius, Audrius; Jenkins, Nick

    2014-01-01

    Highlights: • CAES and CAES with thermal storage systems were investigated. • The potential for using heat generated during the compression stage was analysed. • CAES-TS has the potential to be used both as energy storage and heat source. • CAES-TS could be a useful tool for balancing overall energy demand and supply. - Abstract: The potential for using heat generated during the compression stage of a Compressed Air Energy Storage system was investigated using exergy and exergoeconomic analysis. Two Compressed Air Energy Storage systems were analysed: Compressed Air Energy Storage (CAES) and Compressed Air Energy Storage combined with Thermal Storage (CAES-TS) connected to a district heating network. The maximum output of the CAES was 100 MWe and the output of the CAES-TS was 100 MWe and 105 MWth. The study shows that 308 GW h/year of electricity and 466 GW h/year of fuel are used to generate 375 GW h/year of electricity. During the compression of air 289 GW h/year of heat is generated, which is wasted in the CAES and used for district heating in the CAES-TS system. Energy efficiency of the CAES system was around 48% and the efficiency of CAES-TS was 86%. Exergoeconomic analysis shows that the exergy cost of electricity generated in the CAES was 13.89 ¢/kW h, and the exergy cost of electricity generated in the CAES-TS was 11.20 ¢/kW h. The exergy cost of heat was 22.24 ¢/kW h in the CAES-TS system. The study shows that CAES-TS has the potential to be used both as energy storage and heat source and could be a useful tool for balancing overall energy demand and supply

  15. Subcooled compressed air energy storage system for coproduction of heat, cooling and electricity

    NARCIS (Netherlands)

    Arabkoohsar, A.; Dremark-Larsen, M.; Lorentzen, R.; Andresen, G. B.

    2017-01-01

    Various configurations of compressed air energy storage technology have received attention over the last years due to the advantages that this technology offers relative to other power storage technologies. This work proposes a new configuration of this technology aiming at cogeneration of

  16. Modelling studies for influence factors of gas bubble in compressed air energy storage in aquifers

    International Nuclear Information System (INIS)

    Guo, Chaobin; Zhang, Keni; Li, Cai; Wang, Xiaoyu

    2016-01-01

    CAES (Compressed air energy storage) is credited with its potential ability for large-scale energy storage. Generally, it is more convenient using deep aquifers than employing underground caverns for energy storage, because of extensive presence of aquifers. During the first stage in a typical process of CAESA (compressed air energy storage in aquifers), a large amount of compressed air is injected into the target aquifer to develop an initial space (a gas bubble) for energy storage. In this study, numerical simulations were conducted to investigate the influence of aquifer's permeability, geological structure and operation parameters on the formation of gas bubble and the sustainability for the later cycling operation. The SCT (system cycle times) was designed as a parameter to evaluate the reservoir performance and the effect of operation parameters. Simulation results for pressure and gas saturation results of basic model confirm the feasibility of compressed air energy storage in aquifers. The results of different permeability cases show that, for a certain scale of CAESA system, there is an optimum permeability range for a candidate aquifer. An aquifer within this permeability range will not only satisfy the injectivity requirement but also have the best energy efficiency. Structural impact analysis indicates that the anticline structure has the best performance to hold the bubble under the same daily cycling schedule with the same initial injected air mass. In addition, our results indicate that the SCT shows a logarithmic growth as the injected air mass increase. During the formation of gas bubble, compressed air should be injected into aquifers with moderate rate and the injection can be done in several stages with different injection rate to avoid onset pressure. - Highlights: • Impact of permeability, geological structure, operation parameters was investigated. • With certain air production rate, an optimum permeability exists for performance.

  17. Evaluation of turbine systems for compressed air energy storage plants. Final report for FY 1976

    Energy Technology Data Exchange (ETDEWEB)

    Kartsounes, G.T.

    1976-10-01

    Compressed air energy storage plants for electric utility peak-shaving applications comprise four subsystems: a turbine system, compressor system, an underground air storage reservoir, and a motor/generator. Proposed plant designs use turbines that are derived from available gas and steam turbines with proven reliability. The study examines proposed turbine systems and presents an evaluation of possible systems that may reduce capital cost and/or improve performance. Six new turbine systems are identified for further economic evaluation.

  18. Modeling of Single and Dual Reservoir Porous Media Compressed Gas (Air and CO2) Storage Systems

    Science.gov (United States)

    Oldenburg, C. M.; Liu, H.; Borgia, A.; Pan, L.

    2017-12-01

    Intermittent renewable energy sources are causing increasing demand for energy storage. The deep subsurface offers promising opportunities for energy storage because it can safely contain high-pressure gases. Porous media compressed air energy storage (PM-CAES) is one approach, although the only facilities in operation are in caverns (C-CAES) rather than porous media. Just like in C-CAES, PM-CAES operates generally by injecting working gas (air) through well(s) into the reservoir compressing the cushion gas (existing air in the reservoir). During energy recovery, high-pressure air from the reservoir is mixed with fuel in a combustion turbine to produce electricity, thereby reducing compression costs. Unlike in C-CAES, the storage of energy in PM-CAES occurs variably across pressure gradients in the formation, while the solid grains of the matrix can release/store heat. Because air is the working gas, PM-CAES has fairly low thermal efficiency and low energy storage density. To improve the energy storage density, we have conceived and modeled a closed-loop two-reservoir compressed CO2 energy storage system. One reservoir is the low-pressure reservoir, and the other is the high-pressure reservoir. CO2 is cycled back and forth between reservoirs depending on whether energy needs to be stored or recovered. We have carried out thermodynamic and parametric analyses of the performance of an idealized two-reservoir CO2 energy storage system under supercritical and transcritical conditions for CO2 using a steady-state model. Results show that the transcritical compressed CO2 energy storage system has higher round-trip efficiency and exergy efficiency, and larger energy storage density than the supercritical compressed CO2 energy storage. However, the configuration of supercritical compressed CO2 energy storage is simpler, and the energy storage densities of the two systems are both higher than that of PM-CAES, which is advantageous in terms of storage volume for a given

  19. A Novel Pumped Hydro Combined with Compressed Air Energy Storage System

    Directory of Open Access Journals (Sweden)

    Erren Yao

    2013-03-01

    Full Text Available A novel pumped hydro combined with compressed air energy storage (PHCA system is proposed in this paper to resolve the problems of bulk energy storage in the wind power generation industry over an area in China, which is characterised by drought and water shortages. Thermodynamic analysis of the energy storage system, which focuses on the pre-set pressure, storage volume capacity, water air volume ratio, pump performance, and water turbine performance of the storage system, is also presented. This paper discovers how such parameters affect the performance of the whole system. The ideal performance of this novel system has the following advantages: a simple, highly effective and low cost structure, which is comparable to the efficiency of a traditional pumped hydro storage system. Research results show a great solution to the current storage constraints encountered in the development of the wind power industry in China, which have been widely recognised as a bottleneck in the wind energy storage industry.

  20. Thermodynamic Analysis of Three Compressed Air Energy Storage Systems: Conventional, Adiabatic, and Hydrogen-Fueled

    Directory of Open Access Journals (Sweden)

    Hossein Safaei

    2017-07-01

    Full Text Available We present analyses of three families of compressed air energy storage (CAES systems: conventional CAES, in which the heat released during air compression is not stored and natural gas is combusted to provide heat during discharge; adiabatic CAES, in which the compression heat is stored; and CAES in which the compression heat is used to assist water electrolysis for hydrogen storage. The latter two methods involve no fossil fuel combustion. We modeled both a low-temperature and a high-temperature electrolysis process for hydrogen production. Adiabatic CAES (A-CAES with physical storage of heat is the most efficient option with an exergy efficiency of 69.5% for energy storage. The exergy efficiency of the conventional CAES system is estimated to be 54.3%. Both high-temperature and low-temperature electrolysis CAES systems result in similar exergy efficiencies (35.6% and 34.2%, partly due to low efficiency of the electrolyzer cell. CAES with high-temperature electrolysis has the highest energy storage density (7.9 kWh per m3 of air storage volume, followed by A-CAES (5.2 kWh/m3. Conventional CAES and CAES with low-temperature electrolysis have similar energy densities of 3.1 kWh/m3.

  1. Adiabatic Compressed Air Energy Storage with packed bed thermal energy storage

    International Nuclear Information System (INIS)

    Barbour, Edward; Mignard, Dimitri; Ding, Yulong; Li, Yongliang

    2015-01-01

    Highlights: • The paper presents a thermodynamic analysis of A-CAES using packed bed regenerators. • The packed beds are used to store the compression heat. • A numerical model is developed, validated and used to simulate system operation. • The simulated efficiencies are between 70.5% and 71.1% for continuous operation. • Heat build-up in the beds reduces continuous cycle efficiency slightly. - Abstract: The majority of articles on Adiabatic Compressed Air Energy Storage (A-CAES) so far have focussed on the use of indirect-contact heat exchangers and a thermal fluid in which to store the compression heat. While packed beds have been suggested, a detailed analysis of A-CAES with packed beds is lacking in the available literature. This paper presents such an analysis. We develop a numerical model of an A-CAES system with packed beds and validate it against analytical solutions. Our results suggest that an efficiency in excess of 70% should be achievable, which is higher than many of the previous estimates for A-CAES systems using indirect-contact heat exchangers. We carry out an exergy analysis for a single charge–storage–discharge cycle to see where the main losses are likely to transpire and we find that the main losses occur in the compressors and expanders (accounting for nearly 20% of the work input) rather than in the packed beds. The system is then simulated for continuous cycling and it is found that the build-up of leftover heat from previous cycles in the packed beds results in higher steady state temperature profiles of the packed beds. This leads to a small reduction (<0.5%) in efficiency for continuous operation

  2. Potential hazards of compressed air energy storage in depleted natural gas reservoirs.

    Energy Technology Data Exchange (ETDEWEB)

    Cooper, Paul W.; Grubelich, Mark Charles; Bauer, Stephen J.

    2011-09-01

    This report is a preliminary assessment of the ignition and explosion potential in a depleted hydrocarbon reservoir from air cycling associated with compressed air energy storage (CAES) in geologic media. The study identifies issues associated with this phenomenon as well as possible mitigating measures that should be considered. Compressed air energy storage (CAES) in geologic media has been proposed to help supplement renewable energy sources (e.g., wind and solar) by providing a means to store energy when excess energy is available, and to provide an energy source during non-productive or low productivity renewable energy time periods. Presently, salt caverns represent the only proven underground storage used for CAES. Depleted natural gas reservoirs represent another potential underground storage vessel for CAES because they have demonstrated their container function and may have the requisite porosity and permeability; however reservoirs have yet to be demonstrated as a functional/operational storage media for compressed air. Specifically, air introduced into a depleted natural gas reservoir presents a situation where an ignition and explosion potential may exist. This report presents the results of an initial study identifying issues associated with this phenomena as well as possible mitigating measures that should be considered.

  3. Demonstration of Isothermal Compressed Air Energy Storage to Support Renewable Energy Production

    Energy Technology Data Exchange (ETDEWEB)

    Bollinger, Benjamin [Sustainx, Incorporated, Seabrook, NH (United States)

    2015-01-02

    This project develops and demonstrates a megawatt (MW)-scale Energy Storage System that employs compressed air as the storage medium. An isothermal compressed air energy storage (ICAESTM) system rated for 1 MW or more will be demonstrated in a full-scale prototype unit. Breakthrough cost-effectiveness will be achieved through the use of proprietary methods for isothermal gas cycling and staged gas expansion implemented using industrially mature, readily-available components.The ICAES approach uses an electrically driven mechanical system to raise air to high pressure for storage in low-cost pressure vessels, pipeline, or lined-rock cavern (LRC). This air is later expanded through the same mechanical system to drive the electric motor as a generator. The approach incorporates two key efficiency-enhancing innovations: (1) isothermal (constant temperature) gas cycling, which is achieved by mixing liquid with air (via spray or foam) to exchange heat with air undergoing compression or expansion; and (2) a novel, staged gas-expansion scheme that allows the drivetrain to operate at constant power while still allowing the stored gas to work over its entire pressure range. The ICAES system will be scalable, non-toxic, and cost-effective, making it suitable for firming renewables and for other grid applications.

  4. Factors affecting storage of compressed air in porous-rock reservoirs

    Energy Technology Data Exchange (ETDEWEB)

    Allen, R.D.; Doherty, T.J.; Erikson, R.L.; Wiles, L.E.

    1983-05-01

    This report documents a review and evaluation of the geotechnical aspects of porous medium (aquifer) storage. These aspects include geologic, petrologic, geophysical, hydrologic, and geochemical characteristics of porous rock masses and their interactions with compressed air energy storage (CAES) operations. The primary objective is to present criteria categories for the design and stability of CAES in porous media (aquifers). The document will also describe analytical, laboratory, and field-scale investigations that have been conducted.

  5. Numerical Investigation of the Influences of Wellbore Flow on Compressed Air Energy Storage in Aquifers

    Directory of Open Access Journals (Sweden)

    Yi Li

    2017-01-01

    Full Text Available With the blossoming of intermittent energy, compressed air energy storage (CAES has attracted much attention as a potential large-scale energy storage technology. Compared with caverns as storage vessels, compressed air energy storage in aquifers (CAESA has the advantages of wide availability and lower costs. The wellbore can play an important role as the energy transfer mechanism between the surroundings and the air in CAESA system. In this paper, we investigated the influences of the well screen length on CAESA system performance using an integrated wellbore-reservoir simulator (T2WELL/EOS3. The results showed that the well screen length can affect the distribution of the initial gas bubble and that a system with a fully penetrating wellbore can obtain acceptably stable pressurized air and better energy efficiencies. Subsequently, we investigated the impact of the energy storage scale and the target aquifer depth on the performance of a CAESA system using a fully penetrating wellbore. The simulation results demonstrated that larger energy storage scales exhibit better performances of CAESA systems. In addition, deeper target aquifer systems, which could decrease the energy loss by larger storage density and higher temperature in surrounding formation, can obtain better energy efficiencies.

  6. Porous media experience applicable to field evaluation for compressed air energy storage

    Energy Technology Data Exchange (ETDEWEB)

    Allen, R.D.; Gutknecht, P.J.

    1980-06-01

    A survey is presented of porous media field experience that may aid in the development of a compressed air energy storage field demonstration. Work done at PNL and experience of other groups and related industries is reviewed. An overall view of porous media experience in the underground storage of fluids is presented. CAES experience consists of site evaluation and selection processes used by groups in California, Kansas, and Indiana. Reservoir design and field evaluation of example sites are reported. The studies raised questions about compatibility with depleted oil and gas reservoirs, storage space rights, and compressed air regulations. Related experience embraces technologies of natural gas, thermal energy, and geothermal and hydrogen storage. Natural gas storage technology lends the most toward compressed air storage development, keeping in mind the respective differences between stored fluids, physical conditions, and cycling frequencies. Both fluids are injected under pressure into an aquifer to form a storage bubble confined between a suitable caprock structure and partially displaced ground water. State-of-the-art information is summarized as the necessary foundation material for field planning. Preliminary design criteria are given as recommendations for basic reservoir characteristics. These include geometric dimensions and storage matrix properties such as permeability. Suggested ranges are given for injection air temperature and reservoir pressure. The second step in developmental research is numerical modeling. Results have aided preliminary design by analyzing injection effects upon reservoir pressure, temperature and humidity profiles. Results are reported from laboratory experiments on candidate sandstones and caprocks. Conclusions are drawn, but further verification must be done in the field.

  7. Compressed air energy storage with waste heat export: An Alberta case study

    International Nuclear Information System (INIS)

    Safaei, Hossein; Keith, David W.

    2014-01-01

    Highlights: • Export of compression waste heat from CAES facilities for municipal heating can be profitable. • D-CAES concept has a negative abatement cost of −$40/tCO 2 e under the studied circumstances. • Economic viability of D-CAES highly depends on distance between air storage site and heat load. - Abstract: Interest in compressed air energy storage (CAES) technology has been renewed driven by the need to manage variability form rapidly growing wind and solar capacity. Distributed CAES (D-CAES) design aims to improve the efficiency of conventional CAES through locating the compressor near concentrated heating loads so capturing additional revenue through sales of compression waste heat. A pipeline transports compressed air to the storage facility and expander, co-located at some distance from the compressor. The economics of CAES are strongly dependant on electricity and gas markets in which they are embedded. As a case study, we evaluated the economics of two hypothetical merchant CAES and D-CAES facilities performing energy arbitrage in Alberta, Canada using market data from 2002 to 2011. The annual profit of the D-CAES plant was $1.3 million more on average at a distance of 50 km between the heat load and air storage sites. Superior economic and environmental performance of D-CAES led to a negative abatement cost of −$40/tCO 2 e. We performed a suite of sensitivity analyses to evaluate the impact of size of heat load, size of air storage, ratio of expander to compressor size, and length of pipeline on the economic feasibility of D-CAES

  8. Numerical investigation of a joint approach to thermal energy storage and compressed air energy storage in aquifers

    International Nuclear Information System (INIS)

    Guo, Chaobin; Zhang, Keni; Pan, Lehua; Cai, Zuansi; Li, Cai; Li, Yi

    2017-01-01

    Highlights: •One wellbore-reservoir numerical model was built to study the impact of ATES on CAESA. •With high injection temperature, the joint of ATES can improve CAESA performance. •The considerable utilization of geothermal occurs only at the beginning of operations. •Combination of CAESA and ATES can be achieved in common aquifers. -- Abstract: Different from conventional compressed air energy storage (CAES) systems, the advanced adiabatic compressed air energy storage (AA-CAES) system can store the compression heat which can be used to reheat air during the electricity generation stage. Thus, AA-CAES system can achieve a higher energy storage efficiency. Similar to the AA-CAES system, a compressed air energy storage in aquifers (CAESA) system, which is integrated with an aquifer thermal energy storage (ATES) could possibly achieve the same objective. In order to investigate the impact of ATES on the performance of CAESA, different injection air temperature schemes are designed and analyzed by using numerical simulations. Key parameters relative to energy recovery efficiencies of the different injection schemes, such as pressure distribution and temperature variation within the aquifers as well as energy flow rate in the injection well, are also investigated in this study. The simulations show that, although different injection schemes have a similar overall energy recovery efficiency (∼97%) as well as a thermal energy recovery efficiency (∼79.2%), the higher injection air temperature has a higher energy storage capability. Our results show the total energy storage for the injection air temperature at 80 °C is about 10% greater than the base model scheme at 40 °C. Sensitivity analysis reveal that permeability of the reservoir boundary could have significant impact on the system performance. However, other hydrodynamic and thermodynamic properties, such as the storage reservoir permeability, thermal conductivity, rock grain specific heat and rock

  9. Compressed air energy storage (CAES) - possibilities in Denmark

    DEFF Research Database (Denmark)

    Elmegaard, Brian; Szameitat, Nicklas; Brix, Wiebke

    2005-01-01

    Through a systematic development of the Danish electrical supply system with wind power and CHP, problems with stability and electricity surplus have appeared. Therefore, the possibilities for profitably implementing a CAES plant for energy storage, peak shaving and electricity surplus reduction...... are investigated. Based on existing plants and the latest technology a simulation model of a 360 MW plant with an efficiency of 35 % has been developed and optimized to Danish conditions. An analysis of the economics in the plant, operating under market conditions, shows a growing potential, but the allocated...

  10. A Novel Constant-Pressure Pumped Hydro Combined with Compressed Air Energy Storage System

    Directory of Open Access Journals (Sweden)

    Erren Yao

    2014-12-01

    Full Text Available As intermittent renewable energy is receiving increasing attention, the combination of intermittent renewable energy with large-scale energy storage technology is considered as an important technological approach for the wider application of wind power and solar energy. Pumped hydro combined with compressed air energy storage system (PHCA is one of the energy storage systems that not only integrates the advantages but also overcomes the disadvantages of compressed air energy storage (CAES systems and pumped hydro energy storage systems to solve the problem of energy storage in China’s arid regions. Aiming at the variable working conditions of PHCA system technology, this study proposes a new constant-pressure PHCA. The most significant characteristics of this system were that the water pump and hydroturbine work under stable conditions and this improves the working efficiency of the equipment without incurring an energy loss. In addition, the constant-pressure PHCA system was subjected to energy and exergy analysis, in expectation of exploring an attractive solution for the large-scale storage of existing intermittent renewable energy.

  11. Energy and Exergy Analysis of Ocean Compressed Air Energy Storage Concepts

    Directory of Open Access Journals (Sweden)

    Vikram C. Patil

    2018-01-01

    Full Text Available Optimal utilization of renewable energy resources needs energy storage capability in integration with the electric grid. Ocean compressed air energy storage (OCAES can provide promising large-scale energy storage. In OCAES, energy is stored in the form of compressed air under the ocean. Underwater energy storage results in a constant-pressure storage system which has potential to show high efficiency compared to constant-volume energy storage. Various OCAES concepts, namely, diabatic, adiabatic, and isothermal OCAES, are possible based on the handling of heat in the system. These OCAES concepts are assessed using energy and exergy analysis in this paper. Roundtrip efficiency of liquid piston based OCAES is also investigated using an experimental liquid piston compressor. Further, the potential of improved efficiency of liquid piston based OCAES with use of various heat transfer enhancement techniques is investigated. Results show that adiabatic OCAES shows improved efficiency over diabatic OCAES by storing thermal exergy in thermal energy storage and isothermal OCAES shows significantly higher efficiency over adiabatic and diabatic OCAES. Liquid piston based OCAES is estimated to show roundtrip efficiency of about 45% and use of heat transfer enhancement in liquid piston has potential to improve roundtrip efficiency of liquid piston based OCAES up to 62%.

  12. Thermodynamic characteristics of a novel supercritical compressed air energy storage system

    International Nuclear Information System (INIS)

    Guo, Huan; Xu, Yujie; Chen, Haisheng; Zhou, Xuezhi

    2016-01-01

    Highlights: • A novel supercritical compressed air energy storage system is proposed. • The energy density of SC-CAES is approximately 18 times larger than that of conventional CAES. • The characteristic of thermodynamics and exergy destruction is comprehensively analysed. • The corresponding optimum relationship between charging and discharging pressure is illustrated. • A turning point of efficiency is indicated because of the heat transfer of crossing the critical point. - Abstract: A novel supercritical compressed air energy storage (SC-CAES) system is proposed by our team to solve the problems of conventional CAES. The system eliminates the dependence on fossil fuel and large gas-storage cavern, as well as possesses the advantages of high efficiency by employing the special properties of supercritical air, which is significant for the development of electrical energy storage. The thermodynamic model of the SC-CAES system is built, and the thermodynamic characters are revealed. Through the exergy analysis of the system, the processes of the larger exergy destruction include compression, expansion, cold storage/heat exchange and throttle. Furthermore, sensitivity analysis shows that there is an optimal energy releasing pressure to make the system achieve the highest efficiency when energy storage pressure is constant. The efficiency of SC-CAES is expected to reach about 67.41% when energy storage pressure and energy releasing pressure are 120 bar and 95.01 bar, respectively. At the same time, the energy density is 18 times larger than that of conventional CAES. Sensitivity analysis also shows the change laws of system efficiency varying with other basic system parameters. The study provides support for the design and engineering of SC-CAES.

  13. Design and Analysis of a Solar-Powered Compressed Air Energy Storage System

    Science.gov (United States)

    2016-12-01

    sized PV panel arrays. Kim et al. [49] and Manfrida et al. [50] proposed that a SS-AA- CAES system using COTS parts could be made more economical by...directly improve system efficiency. Furthermore, the power formulas derived using this approach can easily be used to both size the compressor based on...48] Villela, D., Kasinathan, V., De Valle, S., 2010, “Compressed-Air Energy Storage Systems for Stand-Alone Off-Grid Photovoltaic Modules

  14. Preliminary long-term stability criteria for compressed air energy storage caverns in salt domes

    Energy Technology Data Exchange (ETDEWEB)

    Thoms, R.L.; Martinez, J.D.

    1978-08-01

    Air storage caverns, which are an essential and integral component of a CAES plant, should be designed and operated so as to perform satisfactorily over the intended life of the overall facility. It follows that the long-term ''stability'' of air storage caverns must be considered as a primary concern in projecting the satisfactory operation of CAES facilities. As used in the report, ''stability'' of a storage cavern implies the extent to which an acceptable amount of cavern storage volume can be utilized with routine maintenance for a specified time interval, e.g., 35 years. In this context, cavern stability is relative to both planned utilization and time interval of operation. The objective of the study was to review the existing literature and consult knowledgeable workers in the storage industry, and then report state-of-the-art findings relative to long-term stability of compressed air energy storage caverns in salt domes. Further, preliminary cavern stability criteria were to be presented in a form consistent with the amount of information available on cavern performance in salt domes. Another objective of the study was to outline a methodology for determining the long-term stability of site-specific CAES cavern systems in salt domes.

  15. Compressed air energy storage system reservoir size for a wind energy baseload power plant

    Energy Technology Data Exchange (ETDEWEB)

    Cavallo, A.J.

    1996-12-31

    Wind generated electricity can be transformed from an intermittent to a baseload resource using an oversized wind farm in conjunction with a compressed air energy storage (CAES) system. The size of the storage reservoir for the CAES system (solution mined salt cavern or porous media) as a function of the wind speed autocorrelation time (C) has been examined using a Monte Carlo simulation for a wind class 4 (wind power density 450 W m{sup -2} at 50 m hub height) wind regime with a Weibull k factor of 2.5. For values of C typically found for winds over the US Great Plains, the storage reservoir must have a 60 to 80 hour capacity. Since underground reservoirs account for only a small fraction of total system cost, this larger storage reservoir has a negligible effect on the cost of energy from the wind energy baseload system. 7 refs., 2 figs., 1 tab.

  16. Simulation and analysis of different adiabatic Compressed Air Energy Storage plant configurations

    International Nuclear Information System (INIS)

    Hartmann, Niklas; Vöhringer, O.; Kruck, C.; Eltrop, L.

    2012-01-01

    Highlights: ► We modeled several configurations of an adiabatic Compressed Air Energy Storage (CAES) plant. ► We analyzed changes in efficiency of these configurations under varying operating conditions. ► The efficiency of the adiabatic CAES plant can reach about 70% for the isentropic configuration. ► In the polytropic case, the efficiency is about 10% lower (at about 60%) than in the isentropic configuration. ► The efficiency is highest for a two-stage CAES configuration and highly dependent on the cooling and heating demand. - Abstract: In this paper, the efficiency of one full charging and discharging cycle of several adiabatic Compressed Air Energy Storage (CAES) configurations are analyzed with the help of an energy balance. In the second step main driving factors for the efficiency of the CAES configurations are examined with the help of sensitivity analysis. The results show that the efficiency of the polytropic configuration is about 60%, which is considerable lower than literature values of an adiabatic CAES of about 70%. The high value of 70% is only reached for the isentropic (ideal) configuration. Key element to improve the efficiency is to develop high temperature thermal storages (>600 °C) and temperature resistant materials for compressors. The highest efficiency is delivered by the two-stage adiabatic CAES configuration. In this case the efficiency varies between 52% and 62%, depending on the cooling and heating demand. If the cooling is achieved by natural sources (such as a river), a realistic estimation of the efficiency of adiabatic Compressed Air Energy Storages (without any greenhouse gas emissions due to fuel consumption) is about 60%.

  17. Subcooled compressed air energy storage system for coproduction of heat, cooling and electricity

    International Nuclear Information System (INIS)

    Arabkoohsar, A.; Dremark-Larsen, M.; Lorentzen, R.; Andresen, G.B.

    2017-01-01

    Highlights: •A new configuration of compressed air energy storage system is proposed and analyzed. •This system, so-called subcooled-CAES, offers cogeneration of electricity, heat and cooling. •A pseudo-dynamic energy, exergy and economic analysis of the system for an entire year is presented. •The annual power, cooling and heat efficiencies of the system are around 31%, 32% and 92%. •The overall energy and exergy performance coefficients of the system are 1.55 and 0.48, respectively. -- Abstract: Various configurations of compressed air energy storage technology have received attention over the last years due to the advantages that this technology offers relative to other power storage technologies. This work proposes a new configuration of this technology aiming at cogeneration of electricity, heat and cooling. The new system may be very advantageous for locations with high penetration of renewable energy in the electricity grid as well as high heating and cooling demands. The latter would typically be locations with district heating and cooling networks. A thorough design, sizing and thermodynamic analysis of the system for a typical wind farm with 300 MW capacity in Denmark is presented. The results show a great potential of the system to support the local district heating and cooling networks and reserve services in electricity market. The values of power-to-power, power-to-cooling and power-to-heat efficiencies of this system are 30.6%, 32.3% and 92.4%, respectively. The exergy efficiency values are 30.6%, 2.5% and 14.4% for power, cooling and heat productions. A techno-economic comparison of this system with two of the most efficient previous designs of compressed air energy storage system proves the firm superiority of the new concept.

  18. Potential petrophysical and chemical property alterations in a compressed air energy storage porous rock reservoir

    Energy Technology Data Exchange (ETDEWEB)

    Stottlemyre, J.A.; Erikson, R.L.; Smith, R.P.

    1979-10-01

    Successful commercialization of Compressed Air Energy Storage (CAES) systems depends on long-term stability of the underground reservoirs subjected to somewhat unique operating conditions. Specifically, these conditions include elevated and time varying temperatures, effective stresses, and air humidities. To minimize the requirements for premium fuels, it may be desirable to retain the thermal energy of compression. Porous media, e.g., sandstone, may hold promise as elevated temperature reservoirs. In this study, a reservoir composed of clean quartz sandstone and injection air temperatures of 300 to 575/sup 0/K are assumed. Numerical modeling is used to estimate temperature, stress, and humidity conditions within this reference porous media reservoir. A discussion on relative importance to CAES of several potential porous media damage mechanisms is presented. In this context, damage is defined as a reduction in intrinsic permeability (measure of air transport capability), a decrease in effective porosity (measure of storage capability), or an increase in elastic and/or inelastic deformation of the porous material. The potential damage mechanisms presented include: (1) disaggregation, (2) particulate plugging, (3) boundary layer viscosity anomalies, (4) inelastic microstructural consolidation, (5) clay swelling and dispersion, (6) hydrothermal mineral alteration, (7) oxidation reactions, and (8) well casing corrosion. These mechanisms are placed in perspective with respect to anticipated CAES conditions and mechanisms suggested are: (1) of academic interest only, (2) readily identified and controlled via engineering, or (3) potential problem areas requiring additional investigation.

  19. The Fracture Influence on the Energy Loss of Compressed Air Energy Storage in Hard Rock

    Directory of Open Access Journals (Sweden)

    Hehua Zhu

    2015-01-01

    Full Text Available A coupled nonisothermal gas flow and geomechanical numerical modeling is conducted to study the influence of fractures (joints on the complex thermohydromechanical (THM performance of underground compressed air energy storage (CAES in hard rock caverns. The air-filled chamber is modeled as porous media with high porosity, high permeability, and high thermal conductivity. The present analysis focuses on the CAES in hard rock caverns at relatively shallow depth, that is, ≤100 m, and the pressure in carven is significantly higher than ambient pore pressure. The influence of one discrete crack and multiple crackson energy loss analysis of cavern in hard rock media are carried out. Two conditions are considered during each storage and release cycle, namely, gas injection and production mass being equal and additional gas injection supplemented after each cycle. The influence of the crack location, the crack length, and the crack open width on the energy loss is studied.

  20. Prediction of the thermohydraulic performance of porous-media reservoirs for compressed-air energy storage

    Energy Technology Data Exchange (ETDEWEB)

    Wiles, L.E.; McCann, R.A.

    1981-09-01

    The numerical modeling capability that has been developed at the Pacific Northwest Laboratory (PNL) for the prediction of the thermohydraulic performance of porous media reservoirs for compressed air energy storage (CAES) is described. The capability of the numerical models was demonstrated by application to a variety of parametric analyses and the support analyses for the CAES porous media field demonstration program. The demonstration site analyses include calculations for the displacement of aquifer water to develop the air storage zone, the potential for water coning, thermal development in the reservoir, and the dehydration of the near-wellbore region. Unique features of the demonstration site reservoir that affect the thermohydraulic performance are identified and contrasted against the predicted performance for conditions that would be considered more typical of a commercial CAES site.

  1. Thermal System Analysis and Optimization of Large-Scale Compressed Air Energy Storage (CAES

    Directory of Open Access Journals (Sweden)

    Zhongguang Fu

    2015-08-01

    Full Text Available As an important solution to issues regarding peak load and renewable energy resources on grids, large-scale compressed air energy storage (CAES power generation technology has recently become a popular research topic in the area of large-scale industrial energy storage. At present, the combination of high-expansion ratio turbines with advanced gas turbine technology is an important breakthrough in energy storage technology. In this study, a new gas turbine power generation system is coupled with current CAES technology. Moreover, a thermodynamic cycle system is optimized by calculating for the parameters of a thermodynamic system. Results show that the thermal efficiency of the new system increases by at least 5% over that of the existing system.

  2. Automated control of a solar microgrid-powered air compressor for use in a small-scale compressed air energy storage system

    OpenAIRE

    Williams, Joshua N.

    2017-01-01

    Approved for public release; distribution is unlimited As part of the Office of Naval Research's study of advanced energy technologies, this research examined the development and implementation of a control system for the compression phase of a small-scale compressed air energy storage system, using a solar-powered microgrid to store energy as compressed air for later use. The compression system is composed of numerous commercial-off-the-shelf components wherever possible. All electronic c...

  3. Geotechnical issues and guidelines for storage of compressed air in excavated hard rock caverns

    Energy Technology Data Exchange (ETDEWEB)

    Allen, R.D.; Doherty, T.J.; Fossum, A.F.

    1982-04-01

    The results of a literature survey on the stability of excavated hard rock caverns are presented. The objective of the study was to develop geotechnical criteria for the design of compressed air energy storage (CAES) caverns in hard rock formations. These criteria involve geologic, hydrological, geochemical, geothermal, and in situ stress state characteristics of generic rock masses. Their relevance to CAES caverns, and the identification of required research areas, are identified throughout the text. This literature survey and analysis strongly suggests that the chief geotechnical issues for the development and operation of CAES caverns in hard rock are impermeability for containment, stability for sound openings, and hydrostatic balance.

  4. Thermophysical behavior of St. Peter sandstone: application to compressed air energy storage in an aquifer

    Energy Technology Data Exchange (ETDEWEB)

    Erikson, R.L.

    1983-12-01

    The long-term stability of a sandstone reservoir is of primary importance to the success of compressed air energy storage (CAES) in aquifers. The purpose of this study was to: develop experimental techniques for the operation of the CAES Porous Media Flow Loop (PMFL), an apparatus designed to study the stability of porous media in subsurface geologic environments, conduct experiments in the PMFL designed to determine the effects of temperature, stress, and humidity on the stability of candidate CAES reservoir materials, provide support for the CAES field demonstration project in Pittsfield, Illinois, by characterizing the thermophysical stability of Pittsfield reservoir sandstone under simulated field conditions.

  5. Design of a compressed air energy storage system for hydrostatic wind turbines

    Directory of Open Access Journals (Sweden)

    Ammar E. Ali

    2018-03-01

    Full Text Available Integration of Compressed Air Energy Storage (CAES system with a wind turbine is critical in optimally harvesting wind energy given the fluctuating nature of power demands. Here we consider the design of a CAES for a wind turbine with hydrostatic powertrain. The design parameters of the CAES are determined based on simulation of the integrated system model for a combination of these parameter values, namely the compression ratios of the air compressors and the expanders and the air tank size. The results of the simulations were used to choose the best design parameters, which would produce the best stable performance through increased energy output of the integrated CAES and wind turbine based on the intermittent wind profile. Simulation results for a 600 kW rated power wind turbine with integrated CAES indicate that increasing the tank size and compression ratio will improve the overall power quality through increased energy output up to a limit beyond which the power quality exhibits only marginal improvement.

  6. A Coupled Thermo-Hydro-Mechanical Model of Jointed Hard Rock for Compressed Air Energy Storage

    Directory of Open Access Journals (Sweden)

    Xiaoying Zhuang

    2014-01-01

    Full Text Available Renewable energy resources such as wind and solar are intermittent, which causes instability when being connected to utility grid of electricity. Compressed air energy storage (CAES provides an economic and technical viable solution to this problem by utilizing subsurface rock cavern to store the electricity generated by renewable energy in the form of compressed air. Though CAES has been used for over three decades, it is only restricted to salt rock or aquifers for air tightness reason. In this paper, the technical feasibility of utilizing hard rock for CAES is investigated by using a coupled thermo-hydro-mechanical (THM modelling of nonisothermal gas flow. Governing equations are derived from the rules of energy balance, mass balance, and static equilibrium. Cyclic volumetric mass source and heat source models are applied to simulate the gas injection and production. Evaluation is carried out for intact rock and rock with discrete crack, respectively. In both cases, the heat and pressure losses using air mass control and supplementary air injection are compared.

  7. Exergy analysis of an adiabatic compressed air energy storage system using a cascade of phase change materials

    International Nuclear Information System (INIS)

    Tessier, Michael J.; Floros, Michael C.; Bouzidi, Laziz; Narine, Suresh S.

    2016-01-01

    Adiabatic compressed air energy storage is an emerging energy storage technology with excellent power and storage capacities. Currently, efficiencies are approximately 70%, in part due to the issue of heat loss during the compression stage. An exergy analysis is presented on a novel adiabatic compressed air energy storage system design utilizing a cascade of PCMs (phase change materials) for waste heat storage and recovery. The melting temperatures and enthalpies of the PCMs were optimized for this system and were shown to be dependent on the number of PCMs, the number of compression stages, and the maximum compression ratio. Efficiencies of storage and recovery using this approach are predicted to be as high as 85%, a 15% increase over current designs which do not incorporate PCMs. - Highlights: • A compressed air energy storage plant using phase change materials is proposed. • Increasing number of phase change materials increases roundtrip exergy efficiency. • A thermodynamic model allows melting points and latent heats required to be predicted.

  8. Pneumatic hybridization of a diesel engine using compressed air storage for wind-diesel energy generation

    International Nuclear Information System (INIS)

    Basbous, Tammam; Younes, Rafic; Ilinca, Adrian; Perron, Jean

    2012-01-01

    In this paper, we are studying an innovative solution to reduce fuel consumption and production cost for electricity production by Diesel generators. The solution is particularly suitable for remote areas where the cost of energy is very high not only because of inherent cost of technology but also due to transportation costs. It has significant environmental benefits as the use of fossil fuels for electricity generation is a significant source of GHG (Greenhouse Gas) emissions. The use of hybrid systems that combine renewable sources, especially wind, and Diesel generators, reduces fuel consumption and operation cost and has environmental benefits. Adding a storage element to the hybrid system increases the penetration level of the renewable sources, that is the percentage of renewable energy in the overall production, and further improves fuel savings. In a previous work, we demonstrated that CAES (Compressed Air Energy Storage) has numerous advantages for hybrid wind-diesel systems due to its low cost, high power density and reliability. The pneumatic hybridization of the Diesel engine consists to introduce the CAES through the admission valve. We have proven that we can improve the combustion efficiency and therefore the fuel consumption by optimizing Air/Fuel ratio thanks to the CAES assistance. As a continuation of these previous analyses, we studied the effect of the intake pressure and temperature and the exhaust pressure on the thermodynamic cycle of the diesel engine and determined the values of these parameters that will optimize fuel consumption. -- Highlights: ► Fuel economy analysis of a simple pneumatic hybridization of the Diesel engine using stored compressed air. ► Thermodynamic analysis of the pneumatic hybridization of diesel engines for hybrid wind-diesel energy systems. ► Analysis of intake pressure and temperature of compressed air and exhaust pressure on pressure/temperature during Diesel thermodynamic cycle. ► Direct admission of

  9. Thermodynamic analysis of a novel hybrid wind-solar-compressed air energy storage system

    International Nuclear Information System (INIS)

    Ji, Wei; Zhou, Yuan; Sun, Yu; Zhang, Wu; An, Baolin; Wang, Junjie

    2017-01-01

    Highlights: • We present a novel hybrid wind-solar-compressed air energy storage system. • Wind and solar power are transformed into stable electric energy and hot water. • The system output electric power is 8053 kWh with an exergy efficiency of 65.4%. • Parametric sensitivity analysis is presented to optimize system performance. - Abstract: Wind and solar power have embraced a strong development in recent years due to the energy crisis in China. However, owing to their nature of fluctuation and intermittency, some power grid management problems can be caused. Therefore a novel hybrid wind-solar-compressed air energy storage (WS-CAES) system was proposed to solve the problems. The WS-CAES system can store unstable wind and solar power for a stable output of electric energy and hot water. Also, combined with organic Rankin cycle (ORC), the cascade utilization of energy with different qualities was achieved in the WS-CAES system. Aiming to obtain the optimum performance, the analysis of energy, exergy and parametric sensitivity were all conducted for this system. Furthermore, exergy destruction ratio of each component in the WS-CAES system was presented. The results show that the electric energy storage efficiency, round trip efficiency and exergy efficiency can reach 87.7%, 61.2% and 65.4%, respectively. Meanwhile, the parameters analysis demonstrates that the increase of ambient temperature has a negative effect on the system performance, while the increase of turbine inlet temperature has a positive effect. However, when the air turbine inlet pressure varies, there is a tradeoff between the system performance and the energy storage density.

  10. Site specific comparison of H2, CH4 and compressed air energy storage in porous formations

    Science.gov (United States)

    Tilmann Pfeiffer, Wolf; Wang, Bo; Bauer, Sebastian

    2016-04-01

    The supply of energy from renewable sources like wind or solar power is subject to fluctuations determined by the climatic and weather conditions, and shortage periods can be expected on the order of days to weeks. Energy storage is thus required if renewable energy dominates the total energy production and has to compensate the shortages. Porous formations in the subsurface could provide large storage capacities for various energy carriers, such as hydrogen (H2), synthetic methane (CH4) or compressed air (CAES). All three energy storage options have similar requirements regarding the storage site characteristics and consequently compete for suitable subsurface structures. The aim of this work is to compare the individual storage methods for an individual storage site regarding the storage capacity as well as the achievable delivery rates. This objective is pursued using numerical simulation of the individual storage operations. In a first step, a synthetic anticline with a radius of 4 km, a drop of 900 m and a formation thickness of 20 m is used to compare the individual storage methods. The storage operations are carried out using -depending on the energy carrier- 5 to 13 wells placed in the top of the structure. A homogeneous parameter distribution is assumed with permeability, porosity and residual water saturation being 500 mD, 0.35 and 0.2, respectively. N2 is used as a cushion gas in the H2 storage simulations. In case of compressed air energy storage, a high discharge rate of 400 kg/s equating to 28.8 mio. m³/d at surface conditions is required to produce 320 MW of power. Using 13 wells the storage is capable of supplying the specified gas flow rate for a period of 31 hours. Two cases using 5 and 9 wells were simulated for both the H2 and the CH4 storage operation. The target withdrawal rates of 1 mio. sm³/d are maintained for the whole extraction period of one week in all simulations. However, the power output differs with the 5 well scenario producing

  11. Compressed Air Energy Storage System Control and Performance Assessment Using Energy Harvested Index

    Directory of Open Access Journals (Sweden)

    Hanif SedighNejad

    2014-01-01

    Full Text Available In this paper a new concept for control and performance assessment of compressed air energy storage (CAES systems in a hybrid energy system is introduced. The proposed criterion, based on the concept of energy harvest index (HEI, measures the capability of a storage system to capture renewable energy. The overall efficiency of the CAES system and optimum control and design from the technical and economic point of view is presented. A possible application of this idea is an isolated community with significant wind energy resource. A case study reveals the usefulness of the proposed criterion in design, control and implementation of a small CAES system in a hybrid power system (HPM for an isolated community. Energy harvested index and its effectiveness in increasing the wind penetration rate in the total energy production is discussed.

  12. Technology assessment report for the Soyland Power Cooperative, Inc. compressed air energy storage system (CAES)

    Energy Technology Data Exchange (ETDEWEB)

    1982-01-01

    The design and operational features of compressed air energy storage systems (CAES) in general and, specifically, of a proposed 220 MW plant being planned by the Soyland Power Cooperative, Inc. in Illinois are described. This technology assessment discusses the need for peaking capacity, CAES requirements for land, fuel, water, and storage caverns, and compares the costs, environmental impacts and licensing requirements of CAES with those of power plants using simple cycle or combined cycle combustion turbines. It is concluded that during the initial two years of CAES operation, the CAES would cost more than a combustion turbine or combined cycle facility, but thereafter the CAES would have a increasing economic advantage; the overall environmental impact of a CAES plant is minimal, and that there should be no great difficulties with CAES licensing. (LCL)

  13. A Novel Hybrid-Fuel Storage System of Compressed Air Energy for China

    Directory of Open Access Journals (Sweden)

    Wenyi Liu

    2014-08-01

    Full Text Available Compressed air energy storage (CAES is a large-scale technology that provides long-duration energy storage. It is promising for balancing the large-scale penetration of intermittent and dispersed sources of power, such as wind and solar power, into electric grids. The existing CAES plants utilize natural gas (NG as fuel. However, China is rich in coal but is deficient in NG; therefore, a hybrid-fuel CAES is proposed and analyzed in this study. Based on the existing CAES plants, the hybrid-fuel CAES incorporates an external combustion heater into the power generation subsystem to heat the air from the recuperator and the air from the high-pressure air turbine. Coal is the fuel for the external combustion heater. The overall efficiency and exergy efficiency of the hybrid-fuel CAES are 61.18% and 59.84%, respectively. Given the same parameters, the cost of electricity (COE of the hybrid-fuel CAES, which requires less NG, is $5.48/MW∙h less than that of the gas-fuel CAES. Although the proposed CAES requires a relatively high investment in the current electricity system in North China, the proposed CAES will be likely to become competitive in the market, provided that the energy supplies are improved and the large scale grid-connection of wind power is realized.

  14. A review on the recent development of solar absorption and vapour compression based hybrid air conditioning with low temperature storage

    Directory of Open Access Journals (Sweden)

    Noor D. N.

    2016-01-01

    Full Text Available Conventional air conditioners or vapour compression systems are main contributors to energy consumption in modern buildings. There are common environmental issues emanating from vapour compression system such as greenhouse gas emission and heat wastage. These problems can be reduced by adaptation of solar energy components to vapour compression system. However, intermittence input of daily solar radiation was the main issue of solar energy system. This paper presents the recent studies on hybrid air conditioning system. In addition, the basic vapour compression system and components involved in the solar air conditioning system are discussed. Introduction of low temperature storage can be an interactive solution and improved economically which portray different modes of operating strategies. Yet, very few studies have examined on optimal operating strategies of the hybrid system. Finally, the findings of this review will help suggest optimization of solar absorption and vapour compression based hybrid air conditioning system for future work while considering both economic and environmental factors.

  15. Sensitivity analysis for the energy performance assessment of hybrid compressed air energy storage systems

    International Nuclear Information System (INIS)

    Briola, Stefano; Di Marco, Paolo; Gabbrielli, Roberto; Riccardi, Juri

    2017-01-01

    Highlights: •A sensitivity analysis and DOE of the complete hybrid CAES are carried out. •The influence of the storage site volume on performance indicators is negligible. •The performances increase with the decrease of the compressor outlet pressure. •The performances are correlated for each temperature increase in combustion chamber. •Hybridization of Huntorf implies a significant increase of its first law efficiency. -- Abstract: A detailed mathematical model was developed for the complete Hybrid Compressed Air Energy Storage (H-CAES) configuration with underground storage site and liquid thermal energy storage, operating with a sequence of processes (charging, holding and discharging with respective duration) in arbitrary order. A sensitivity analysis was carried out in order to calculate several performance indicators of the complete H-CAES configuration, in relation to the simultaneous change of several process parameters. The methodology “Design of Experiments” was applied to the results of the sensitivity analysis in order to calculate the main effects of each process parameter on each performance indicator. The influence of the storage site volume on each performance indicator is negligible. The reduction of the compressor group outlet pressure and of the turbine group power allows a more effective thermodynamic utilization both of the energy stored by the compressors and of the overall energy supplied to the plant. Furthermore, the former utilization is more effective by an increase of the gas temperature in the combustion chambers, whereas the latter utilization is worsened. Moreover, as case study, the existing diabatic CAES plant of Huntorf was modified by introducing a diathermic oil thermal storage. This plant is suitable to operate according to a partial hybrid configuration by the deactivation of the heat exchanger located upstream of the low pressure turbine. The thermodynamic utilization of the overall energy supplied to the plant

  16. Technical and economic assessment of fluidized bed augmented compressed air energy storage system. Volume III. Preconceptual design

    Energy Technology Data Exchange (ETDEWEB)

    Giramonti, A.J.; Lessard, R.D.; Merrick, D.; Hobson, M.J.

    1981-09-01

    A technical and economic assessment of fluidized bed combustion augmented compressed air energy storage systems is presented. The results of this assessment effort are presented in three volumes. Volume III - Preconceptual Design contains the system analysis which led to the identification of a preferred component configuration for a fluidized bed combustion augmented compressed air energy storage system, the results of the effort which transformed the preferred configuration into preconceptual power plant design, and an introductory evaluation of the performance of the power plant system during part-load operation and while load following.

  17. Preliminary engineering design and cost of Advanced Compressed-Air Storage (ACAS) A-5 hybrid

    Science.gov (United States)

    Sosnowicz, E. J.; Blackman, J.; Woodhull, A. S.; Zaugg, P.

    1981-08-01

    The advanced compressed air energy (ACAS) plant investiated operates on a partial adiabatic, partial fuel fired cycle. Only a limited advancement in state-of-the-art technology is projected for this hybrid arrangement. The A-5 hybrid systems stores the heat of compression from the low pressure and intermediate pressure compressors in a thermal energy store (TES). The heat collected in the TES is available for preheating the air from the storage cavern prior to its entering the low pressure turbine combustor. This reduces the amount of fuel consumed during power generation. The fuel heat rate for the hybrid cycle is 2660 Btu/kWh as compared to approximately 4000 Btu/kWh for a conventional CAES plant. A virtual stand-off between the hybrid plant and a conventional CAES plant at 235 mills/kWh in 1990 dollars is shown. With a lower cost and increased fuel cost projections, the hybrid system operating cost is less than that for a conventional CAES plant.

  18. Compressed air storage with humidification (CASH) coal gasification power plant investigation

    International Nuclear Information System (INIS)

    Nakhamkin, M.; Patel, M.

    1991-08-01

    A study was performed to investigate and develop a hybrid coal gasification concept which utilizes an air saturator (AS) with an integrated coal gasification/compressed air energy storage (CGS/CAES) plant. This potentially attractive concept is designated as AS/CGS/CAES. In this concept, the coal gasification system provides fuel for the combustors of the CAES reheat turbomachinery train. Motive air from underground storage is humidified by saturators and thereby provides increased power production without additional air consumption. The heat for generating the hot water utilized in the saturators is extracted from waste heat within the overall plant. Multiple alternatives were considered and parametrically analyzed in the study in order to select the most thermodynamically and economically attractive concepts. The major alternatives were differentiated by the type of gasifier, type of CAES turbomachinery, mode of operation, and utilization of waste heat. The results of the study indicate that the use of the air saturation in AS/CGS/CAES plants might reduce capital costs of coal gasification based power used in intermediate load generation by $300 to $400 per kilowatt. Furthermore, heat rates might also be reduced by almost 1.5 cents per kilowatt hour, a major reduction. The major cause of the reduction in electricity costs is a 50% reduction in the required gasification capacity per net kW. In addition to being a load management tool, AS/CGS/CAES concepts provide a method to operate the CGS and turbomachinery in a continuous mode, improving the operation and potentially the life expectancy of both components. 3 refs., 18 figs., 4 tabs

  19. Impacts of compressed air energy storage plant on an electricity market with a large renewable energy portfolio

    International Nuclear Information System (INIS)

    Foley, A.; Díaz Lobera, I.

    2013-01-01

    Renewable energy generation is expected to continue to increase globally due to renewable energy targets and obligations to reduce greenhouse gas emissions. Some renewable energy sources are variable power sources, for example wind, wave and solar. Energy storage technologies can manage the issues associated with variable renewable generation and align non-dispatchable renewable energy generation with load demands. Energy storage technologies can play different roles in each of the step of the electric power supply chain. Moreover, large scale energy storage systems can act as renewable energy integrators by smoothing the variability. Compressed air energy storage is one such technology. This paper examines the impacts of a compressed air energy storage facility in a pool based wholesale electricity market in a power system with a large renewable energy portfolio

  20. Theoretical evaluation on the impact of heat exchanger in Advanced Adiabatic Compressed Air Energy Storage system

    International Nuclear Information System (INIS)

    Yang, Ke; Zhang, Yuan; Li, Xuemei; Xu, Jianzhong

    2014-01-01

    Highlights: • A multi-stage AA-CAES system model is established based on thermodynamic theory. • Four Cases about pressure loss and effectiveness of heat exchanger are investigated. • The impact of pressure loss on conversion of heat energy in TES is more sensitive. • The impact of heat exchanger effectiveness in charge process on system is stronger. • Pressure loss in heat exchanger affects the change trends of system efficiency. - Abstract: Advanced Adiabatic Compressed Air Energy Storage (AA-CAES) is a large-scale energy storage system based on gas turbine technology and thermal energy storage (TES). Electrical energy can be converted into internal energy of air and heat energy in TES during the charge process, while reverse energy conversion proceeds during discharge process. The performance of AA-CAES system requires further improvement in order to increase efficiency. In this paper, a multi-stage AA-CAES system model is established, and the influence of effectiveness and pressure loss in heat exchanger on energy conversion and utilization efficiency of AA-CAES system is analyzed theoretically based on the theory of thermodynamics. Four Cases about effectiveness and pressure loss of heat exchanger are investigated and compared with each other. It is found that effectiveness and pressure loss of heat exchanger are directly related to energy conversion and utilization in AA-CAES system. System efficiency changes with the variation of heat exchanger effectiveness and the impact of pressure loss on conversion of heat energy in TES is more sensitive than that of internal energy of air. Pressure loss can cause the complexity of system efficiency change. With appropriate selection of the values of heat exchanger effectiveness for both charge and discharge processes, an AA-CAES system with a higher efficiency could be expected

  1. Analysis of flexible fabric structures for large-scale subsea compressed air energy storage

    International Nuclear Information System (INIS)

    Pimm, A; Garvey, S

    2009-01-01

    The idea of storing compressed air in submerged flexible fabric structures anchored to the seabed is being investigated for its potential to be a clean, economically-attractive means of energy storage which could integrate well with offshore renewable energy conversion. In this paper a simple axisymmetric model of an inextensional pressurised bag is presented, along with its implementation in a constrained multidimensional optimization used to minimise the cost of the bag materials per unit of stored energy. Base pressure difference and circumferential stress are included in the optimization, and the effect of hanging ballast masses from the inside of the bag is also considered. Results are given for a zero pressure natural shape bag, a zero pressure bag with circumferential stress and hanging masses, and a nonzero pressure bag with circumferential stress and hanging masses.

  2. Combined compressed air storage-low BTU coal gasification power plant

    Science.gov (United States)

    Kartsounes, George T.; Sather, Norman F.

    1979-01-01

    An electrical generating power plant includes a Compressed Air Energy Storage System (CAES) fueled with low BTU coal gas generated in a continuously operating high pressure coal gasifier system. This system is used in coordination with a continuously operating main power generating plant to store excess power generated during off-peak hours from the power generating plant, and to return the stored energy as peak power to the power generating plant when needed. The excess coal gas which is produced by the coal gasifier during off-peak hours is stored in a coal gas reservoir. During peak hours the stored coal gas is combined with the output of the coal gasifier to fuel the gas turbines and ultimately supply electrical power to the base power plant.

  3. Transmission Congestion Management using a Wind Integrated Compressed Air Energy Storage System

    Directory of Open Access Journals (Sweden)

    S. Gope

    2017-08-01

    Full Text Available Transmission congestion is a vital problem in the power system security and reliability sector. To ensure the stable operation of the system, a congestion free power network is desirable. In this paper, a new Congestion Management (CM technique, the Wind integrated Compressed Air Energy Storage (WCAES system is used to alleviate transmission congestion and to minimize congestion mitigation cost. The CM problem has been solved by using the Generator Sensitivity Factor (GSF and the Bus Sensitivity Factor (BSF. BSF is used for finding the optimal location of WCAES in the system. GSF with a Moth Flame Optimization (MFO algorithm is used for rescheduling the generators to alleviate congestion and to minimize congestion cost by improving security margin. The impact of the WCAES system is tested with a 39 bus system. To validate this approach, the same problem has been solved with a Particle Swarm Optimization (PSO algorithm and the obtained results are compared with the ones from the MFO algorithm.

  4. Compressed-air energy storage: Commercialization potential and EPRI roles in the commercialization process

    Science.gov (United States)

    Boyd, D. W.; Buckley, O. E.; Clark, C. E.

    1982-12-01

    This report describes an assessment of potential roles that EPRI might take to facilitate the commercial acceptance of compressed air energy storage (CAES) systems. The assessment is based on (1) detailed analyses of the market potential of utility storage technologies, (2) interviews with representatives of key participants in the CAES market, and (3) a decision analysis synthesizing much of the information about market and technology status. The results indicate a large potential market for CAES systems if the overall business environment for utilities improves. In addition, it appears that EPRI can have a valuable incremental impact in ensuring that utilities realize the potential of CAES by (1) continuing an aggressive information dissemination and technology transfer program, (2) working to ensure the success of the first United States CAES installation at Soyland Power Cooperative, (3) developing planning methods to allow utilities to evaluate CAES and other storage options more effectively and more realistically, and (4) supporting R and D to resolve residual uncertainties in first-generation CAES cost and performance characteristics.

  5. Operational design and pressure response of large-scale compressed air energy storage in porous formations

    Science.gov (United States)

    Wang, Bo; Bauer, Sebastian

    2017-04-01

    With the rapid growth of energy production from intermittent renewable sources like wind and solar power plants, large-scale energy storage options are required to compensate for fluctuating power generation on different time scales. Compressed air energy storage (CAES) in porous formations is seen as a promising option for balancing short-term diurnal fluctuations. CAES is a power-to-power energy storage, which converts electricity to mechanical energy, i.e. highly pressurized air, and stores it in the subsurface. This study aims at designing the storage setup and quantifying the pressure response of a large-scale CAES operation in a porous sandstone formation, thus assessing the feasibility of this storage option. For this, numerical modelling of a synthetic site and a synthetic operational cycle is applied. A hypothetic CAES scenario using a typical anticline structure in northern Germany was investigated. The top of the storage formation is at 700 m depth and the thickness is 20 m. The porosity and permeability were assumed to have a homogenous distribution with a value of 0.35 and 500 mD, respectively. According to the specifications of the Huntorf CAES power plant, a gas turbine producing 321 MW power with a minimum inlet pressure of 43 bars at an air mass flowrate of 417 kg/s was assumed. Pressure loss in the gas wells was accounted for using an analytical solution, which defines a minimum bottom hole pressure of 47 bars. Two daily extraction cycles of 6 hours each were set to the early morning and the late afternoon in order to bypass the massive solar energy production around noon. A two-year initial filling of the reservoir with air and ten years of daily cyclic operation were numerically simulated using the Eclipse E300 reservoir simulator. The simulation results show that using 12 wells the storage formation with a permeability of 500 mD can support the required 6-hour continuous power output of 321MW, which corresponds an energy output of 3852 MWh per

  6. Feasibility study of a hybrid wind turbine system – Integration with compressed air energy storage

    International Nuclear Information System (INIS)

    Sun, Hao; Luo, Xing; Wang, Jihong

    2015-01-01

    Highlights: • A new hybrid wind turbine system is proposed and feasibility study if conducted. • A complete mathematical model is developed and implemented in a software environment. • Multi-mode control strategy is investigated to ensure the system work smoothly and efficiently. • A prototype for implementing the proposed mechanism is built and tested as proof of the concept. • The proposed system is proved to be technically feasible with energy efficiency around 50%. - Abstract: Wind has been recognized as one of major realistic clean energy sources for power generation to meet the continuously increased energy demand and to achieve the carbon emission reduction targets. However, the utilisation of wind energy encounters an inevitable challenge resulting from the nature of wind intermittency. To address this, the paper presents the recent research work at Warwick on the feasibility study of a new hybrid system by integrating a wind turbine with compressed air energy storage. A mechanical transmission mechanism is designed and implemented for power integration within the hybrid system. A scroll expander is adopted to serve as an “air-machinery energy converter”, which can transmit additional driving power generalized from the stored compressed air to the turbine shaft for smoothing the wind power fluctuation. A mathematical model for the complete hybrid process is developed and the control strategy is investigated for corresponding cooperative operations. A prototype test rig for implementing the proposed mechanism is built for proof of the concept. From the simulated and experimental studies, the energy conversion efficiency analysis is conducted while the system experiences different operation conditions and modes. It is proved that the proposed hybrid wind turbine system is feasible technically

  7. Analysis of an integrated packed bed thermal energy storage system for heat recovery in compressed air energy storage technology

    International Nuclear Information System (INIS)

    Ortega-Fernández, Iñigo; Zavattoni, Simone A.; Rodríguez-Aseguinolaza, Javier; D'Aguanno, Bruno; Barbato, Maurizio C.

    2017-01-01

    Highlights: •A packed bed TES system is proposed for heat recovery in CAES technology. •A CFD-based approach has been developed to evaluate the behaviour of the TES unit. •TES system enhancement and improvement alternatives are also demonstrated. •TES performance evaluated according to the first and second law of thermodynamics. -- Abstract: Compressed air energy storage (CAES) represents a very attracting option to grid electric energy storage. Although this technology is mature and well established, its overall electricity-to-electricity cycle efficiency is lower with respect to other alternatives such as pumped hydroelectric energy storage. A meager heat management strategy in the CAES technology is among the main reasons of this gap of efficiency. In current CAES plants, during the compression stage, a large amount of thermal energy is produced and wasted. On the other hand, during the electricity generation stage, an extensive heat supply is required, currently provided by burning natural gas. In this work, the coupling of both CAES stages through a thermal energy storage (TES) unit is introduced as an effective solution to achieve a noticeable increase of the overall CAES cycle efficiency. In this frame, the thermal energy produced in the compression stage is stored in a TES unit for its subsequent deployment during the expansion stage, realizing an Adiabatic-CAES plant. The present study addresses the conceptual design of a TES system based on a packed bed of gravel to be integrated in an Adiabatic-CAES plant. With this objective, a complete thermo-fluid dynamics model has been developed, including the implications derived from the TES operating under variable-pressure conditions. The formulation and treatment of the high pressure conditions were found being particularly relevant issues. Finally, the model provided a detailed performance and efficiency analysis of the TES system under charge/discharge cyclic conditions including a realistic operative

  8. Multi-objective optimization and exergoeconomic analysis of a combined cooling, heating and power based compressed air energy storage system

    International Nuclear Information System (INIS)

    Yao, Erren; Wang, Huanran; Wang, Ligang; Xi, Guang; Maréchal, François

    2017-01-01

    Highlights: • A novel tri-generation based compressed air energy storage system. • Trade-off between efficiency and cost to highlight the best compromise solution. • Components with largest irreversibility and potential improvements highlighted. - Abstract: Compressed air energy storage technologies can improve the supply capacity and stability of the electricity grid, particularly when fluctuating renewable energies are massively connected. While incorporating the combined cooling, heating and power systems into compressed air energy storage could achieve stable operation as well as efficient energy utilization. In this paper, a novel combined cooling, heating and power based compressed air energy storage system is proposed. The system combines a gas engine, supplemental heat exchangers and an ammonia-water absorption refrigeration system. The design trade-off between the thermodynamic and economic objectives, i.e., the overall exergy efficiency and the total specific cost of product, is investigated by an evolutionary multi-objective algorithm for the proposed combined system. It is found that, with an increase in the exergy efficiency, the total product unit cost is less affected in the beginning, while rises substantially afterwards. The best trade-off solution is selected with an overall exergy efficiency of 53.04% and a total product unit cost of 20.54 cent/kWh, respectively. The variation of decision variables with the exergy efficiency indicates that the compressor, turbine and heat exchanger preheating the inlet air of turbine are the key equipment to cost-effectively pursuit a higher exergy efficiency. It is also revealed by an exergoeconomic analysis that, for the best trade-off solution, the investment costs of the compressor and the two heat exchangers recovering compression heat and heating up compressed air for expansion should be reduced (particularly the latter), while the thermodynamic performance of the gas engine need to be improved

  9. Preliminary formation analysis for compressed air energy storage in depleted natural gas reservoirs :

    Energy Technology Data Exchange (ETDEWEB)

    Gardner, William Payton

    2013-06-01

    The purpose of this study is to develop an engineering and operational understanding of CAES performance for a depleted natural gas reservoir by evaluation of relative permeability effects of air, water and natural gas in depleted natural gas reservoirs as a reservoir is initially depleted, an air bubble is created, and as air is initially cycled. The composition of produced gases will be evaluated as the three phase flow of methane, nitrogen and brine are modeled. The effects of a methane gas phase on the relative permeability of air in a formation are investigated and the composition of the produced fluid, which consists primarily of the amount of natural gas in the produced air are determined. Simulations of compressed air energy storage (CAES) in depleted natural gas reservoirs were carried out to assess the effect of formation permeability on the design of a simple CAES system. The injection of N2 (as a proxy to air), and the extraction of the resulting gas mixture in a depleted natural gas reservoir were modeled using the TOUGH2 reservoir simulator with the EOS7c equation of state. The optimal borehole spacing was determined as a function of the formation scale intrinsic permeability. Natural gas reservoir results are similar to those for an aquifer. Borehole spacing is dependent upon the intrinsic permeability of the formation. Higher permeability allows increased injection and extraction rates which is equivalent to more power per borehole for a given screen length. The number of boreholes per 100 MW for a given intrinsic permeability in a depleted natural gas reservoir is essentially identical to that determined for a simple aquifer of identical properties. During bubble formation methane is displaced and a sharp N2methane boundary is formed with an almost pure N2 gas phase in the bubble near the borehole. During cycling mixing of methane and air occurs along the boundary as the air bubble boundary moves. The extracted gas mixture changes as a

  10. Compressed gas fuel storage system

    Science.gov (United States)

    Wozniak, John J.; Tiller, Dale B.; Wienhold, Paul D.; Hildebrand, Richard J.

    2001-01-01

    A compressed gas vehicle fuel storage system comprised of a plurality of compressed gas pressure cells supported by shock-absorbing foam positioned within a shape-conforming container. The container is dimensioned relative to the compressed gas pressure cells whereby a radial air gap surrounds each compressed gas pressure cell. The radial air gap allows pressure-induced expansion of the pressure cells without resulting in the application of pressure to adjacent pressure cells or physical pressure to the container. The pressure cells are interconnected by a gas control assembly including a thermally activated pressure relief device, a manual safety shut-off valve, and means for connecting the fuel storage system to a vehicle power source and a refueling adapter. The gas control assembly is enclosed by a protective cover attached to the container. The system is attached to the vehicle with straps to enable the chassis to deform as intended in a high-speed collision.

  11. A low-cost hybrid drivetrain concept based on compressed air energy storage

    International Nuclear Information System (INIS)

    Brown, T.L.; Atluri, V.P.; Schmiedeler, J.P.

    2014-01-01

    Highlights: • A new pneumatic hybrid concept is introduced. • A proof-of-concept prototype system is built and tested. • The experimental system has a round-trip efficiency of just under 10%. • A thermodynamics model is used to predict the performance of modified designs. • An efficiency of nearly 50% is possible with reasonable design changes. - Abstract: This paper introduces a new low-cost hybrid drivetrain concept based on compressed air energy storage. In contrast to most contemporary approaches to pneumatic hybridization, which require modification to the primary power plant, this concept is based on a stand-alone pneumatic system that could be readily integrated with existing vehicles. The pneumatic system consists of an air tank and a compressor–expander that is coupled to the rest of the drivetrain via an infinitely variable transmission. Rather than incorporating more expensive technologies such as variable valve timing or a variable compression ratio compressor, a fixed valve system consisting of a rotary valve and passive check valves is optimized to operate efficiently over a range of tank pressures. The feasibility of this approach is established by thermodynamic modeling and the construction of a proof-of-concept prototype, which is also used to fine tune model parameters. While the proof-of-concept system shows a round trip efficiency of just under 10%, modeling shows that a round trip efficiency of 26% is possible with a revised design. If waste heat from the engine is used to maintain an elevated tank temperature, efficiencies of nearly 50% may be possible, indicating that the concept could be effective for practical hybridization of passenger vehicles

  12. Structural analysis of porous rock reservoirs subjected to conditions of compressed air energy storage

    Energy Technology Data Exchange (ETDEWEB)

    Friley, J.R.

    1980-01-01

    Investigations are described which were performed to assess the structural behavior of porous rock compressed air energy storage (CAES) reservoirs subjected to loading conditions of temperature and pressure felt to be typical of such an operation. Analyses performed addressed not only the nominal or mean reservoir response but also the cyclic response due to charge/discharge operation. The analyses were carried out by assuming various geometrical and material related parameters of a generic site. The objective of this study was to determine the gross response of a generic porous reservoir. The site geometry for this study assumed a cylindrical model 122 m in dia and 57 m high including thicknesses for the cap, porous, and base rock formations. The central portion of the porous zone was assumed to be at a depth of 518 m and at an initial temperature of 20/sup 0/C. Cyclic loading conditions of compressed air consisted of pressure values in the range of 4.5 to 5.2 MPa and temperature values between 143 and 204/sup 0/C.Various modes of structural behavior were studied. These response modes were analyzed using loading conditions of temperature and pressure (in the porous zone) corresponding to various operational states during the first year of simulated site operation. The results of the structural analyses performed indicate that the most severely stressed region will likely be in the wellbore vicinity and hence highly dependent on the length of and placement technique utilized in the well production length. Analyses to address this specific areas are currently being pursued.

  13. Power-to-heat in adiabatic compressed air energy storage power plants for cost reduction and increased flexibility

    Science.gov (United States)

    Dreißigacker, Volker

    2018-04-01

    The development of new technologies for large-scale electricity storage is a key element in future flexible electricity transmission systems. Electricity storage in adiabatic compressed air energy storage (A-CAES) power plants offers the prospect of making a substantial contribution to reach this goal. This concept allows efficient, local zero-emission electricity storage on the basis of compressed air in underground caverns. The compression and expansion of air in turbomachinery help to balance power generation peaks that are not demand-driven on the one hand and consumption-induced load peaks on the other. For further improvements in cost efficiencies and flexibility, system modifications are necessary. Therefore, a novel concept regarding the integration of an electrical heating component is investigated. This modification allows increased power plant flexibilities and decreasing component sizes due to the generated high temperature heat with simultaneously decreasing total round trip efficiencies. For an exemplarily A-CAES case simulation studies regarding the electrical heating power and thermal energy storage sizes were conducted to identify the potentials in cost reduction of the central power plant components and the loss in round trip efficiency.

  14. Multi-objective optimization of an underwater compressed air energy storage system using genetic algorithm

    International Nuclear Information System (INIS)

    Cheung, Brian C.; Carriveau, Rupp; Ting, David S.K.

    2014-01-01

    This paper presents the findings from a multi-objective genetic algorithm optimization study on the design parameters of an underwater compressed air energy storage system (UWCAES). A 4 MWh UWCAES system was numerically simulated and its energy, exergy, and exergoeconomics were analysed. Optimal system configurations were determined that maximized the UWCAES system round-trip efficiency and operating profit, and minimized the cost rate of exergy destruction and capital expenditures. The optimal solutions obtained from the multi-objective optimization model formed a Pareto-optimal front, and a single preferred solution was selected using the pseudo-weight vector multi-criteria decision making approach. A sensitivity analysis was performed on interest rates to gauge its impact on preferred system designs. Results showed similar preferred system designs for all interest rates in the studied range. The round-trip efficiency and operating profit of the preferred system designs were approximately 68.5% and $53.5/cycle, respectively. The cost rate of the system increased with interest rates. - Highlights: • UWCAES system configurations were developed using multi-objective optimization. • System was optimized for energy efficiency, exergy, and exergoeconomics • Pareto-optimal solution surfaces were developed at different interest rates. • Similar preferred system configurations were found at all interest rates studied

  15. Modeling of coupled thermodynamic and geomechanical performance of underground compressed air energy storage in lined rock caverns

    Energy Technology Data Exchange (ETDEWEB)

    Rutqvist, Jonny; Kim, Hyung-Mok; Ryu, Dong-Woo; Synn, Joong-Ho; Song, Won-Kyong

    2012-06-01

    We applied coupled nonisothermal, multiphase fluid flow and geomechanical numerical modeling to study the coupled thermodynamic and geomechanical performance of underground compressed air energy storage (CAES) in concrete-lined rock caverns. The paper focuses on CAES in lined caverns at relatively shallow depth (e.g., 100 m depth) in which a typical CAES operational pressure of 5 to 8 MPa is significantly higher than both ambient fluid pressure and in situ stress. We simulated a storage operation that included cyclic compression and decompression of air in the cavern, and investigated how pressure, temperature and stress evolve over several months of operation. We analyzed two different lining options, both with a 50 cm thick low permeability concrete lining, but in one case with an internal synthetic seal such as steel or rubber. For our simulated CAES system, the thermodynamic analysis showed that 96.7% of the energy injected during compression could be recovered during subsequent decompression, while 3.3% of the energy was lost by heat conduction to the surrounding media. Our geomechanical analysis showed that tensile effective stresses as high as 8 MPa could develop in the lining as a result of the air pressure exerted on the inner surface of the lining, whereas thermal stresses were relatively smaller and compressive. With the option of an internal synthetic seal, the maximum effective tensile stress was reduced from 8 to 5 MPa, but was still in substantial tension. We performed one simulation in which the tensile tangential stresses resulted in radial cracks and air leakage though the lining. This air leakage, however, was minor (about 0.16% of the air mass loss from one daily compression) in terms of CAES operational efficiency, and did not significantly impact the overall energy balance of the system. However, despite being minor in terms of energy balance, the air leakage resulted in a distinct pressure increase in the surrounding rock that could be

  16. Economics of compressed air energy storage to integrate wind power: A case study in ERCOT

    Energy Technology Data Exchange (ETDEWEB)

    Fertig, Emily, E-mail: efertig@andrew.cmu.ed [Carnegie Mellon Electricity Industry Center, Department of Engineering and Public Policy and Tepper School of Business, Carnegie Mellon University, 5000 Forbes Avenue, Pittsburgh, PA 15213 (United States); Apt, Jay [Carnegie Mellon Electricity Industry Center, Department of Engineering and Public Policy and Tepper School of Business, Carnegie Mellon University, 5000 Forbes Avenue, Pittsburgh, PA 15213 (United States)

    2011-05-15

    Compressed air energy storage (CAES) could be paired with a wind farm to provide firm, dispatchable baseload power, or serve as a peaking plant and capture upswings in electricity prices. We present a firm-level engineering-economic analysis of a wind/CAES system with a wind farm in central Texas, load in either Dallas or Houston, and a CAES plant whose location is profit-optimized. With 2008 hourly prices and load in Houston, the economically optimal CAES expander capacity is unrealistically large - 24 GW - and dispatches for only a few hours per week when prices are highest; a price cap and capacity payment likewise results in a large (17 GW) profit-maximizing CAES expander. Under all other scenarios considered the CAES plant is unprofitable. Using 2008 data, a baseload wind/CAES system is less profitable than a natural gas combined cycle (NGCC) plant at carbon prices less than $56/tCO{sub 2} ($15/MMBTU gas) to $230/tCO{sub 2} ($5/MMBTU gas). Entering regulation markets raises profit only slightly. Social benefits of CAES paired with wind include avoided construction of new generation capacity, improved air quality during peak times, and increased economic surplus, but may not outweigh the private cost of the CAES system nor justify a subsidy. - Research highlights: {yields} Sizes of CAES and transmission paired with a Texas wind farm are optimized for profit. {yields} A profit-maximizing wind farm owner would not invest in a dedicated CAES system. {yields} The social benefit of a wind/CAES system is unlikely to outweigh private cost. {yields} CAES cannot cost-effectively smooth wind power with plausible imminent carbon prices.

  17. Economics of compressed air energy storage to integrate wind power: A case study in ERCOT

    International Nuclear Information System (INIS)

    Fertig, Emily; Apt, Jay

    2011-01-01

    Compressed air energy storage (CAES) could be paired with a wind farm to provide firm, dispatchable baseload power, or serve as a peaking plant and capture upswings in electricity prices. We present a firm-level engineering-economic analysis of a wind/CAES system with a wind farm in central Texas, load in either Dallas or Houston, and a CAES plant whose location is profit-optimized. With 2008 hourly prices and load in Houston, the economically optimal CAES expander capacity is unrealistically large - 24 GW - and dispatches for only a few hours per week when prices are highest; a price cap and capacity payment likewise results in a large (17 GW) profit-maximizing CAES expander. Under all other scenarios considered the CAES plant is unprofitable. Using 2008 data, a baseload wind/CAES system is less profitable than a natural gas combined cycle (NGCC) plant at carbon prices less than $56/tCO 2 ($15/MMBTU gas) to $230/tCO 2 ($5/MMBTU gas). Entering regulation markets raises profit only slightly. Social benefits of CAES paired with wind include avoided construction of new generation capacity, improved air quality during peak times, and increased economic surplus, but may not outweigh the private cost of the CAES system nor justify a subsidy. - Research highlights: → Sizes of CAES and transmission paired with a Texas wind farm are optimized for profit. → A profit-maximizing wind farm owner would not invest in a dedicated CAES system. → The social benefit of a wind/CAES system is unlikely to outweigh private cost. → CAES cannot cost-effectively smooth wind power with plausible imminent carbon prices.

  18. Technical and economic assessment of fluidized-bed-augmented compressed-air energy-storage system. Volume I. Executive summary

    Energy Technology Data Exchange (ETDEWEB)

    Giramonti, A.J.; Lessard, R.D.; Merrick, D.; Hobson, M.J.

    1981-09-01

    An energy storage system which could be attractive for future electric utility peak-load applications is a modified gas turbine power system utilizing underground storage of very high pressure air. The compressed air energy storage (CAES) concept involves using off-peak electricity generated from indigenous coal or nuclear sources to compress air, storing the air in large underground facilities, and withdrawing the air during peak-load periods when it would be heated by combustion and expanded through gas turbines to generate power. The attractiveness of the CAES concept is based upon its potential to supply competitively priced peaking energy, to reduce peak-load power plant dependence on petroleum-based fuels, and to provide a means for leveling the utility system load demand. Therefore, a technical and economic assessment of coal-fired fluidized bed (FBC) combustor/compressed air energy storage (FBC/CAES) systems was performed and is described. The conclusions drawn from the FBC/CAES study program are encouraging. They indicate that pressurized FBC/CAES power plants should be technologically feasible, provide good performance, and be economically competitive. Specifically, it is concluded that: coal-fired FBC/CAES systems should be technically feasible in the near future and potentially attractive for peak-load power generation; and an open-bed PFBC/CAES configuration would provide the best candidate for early commercialization. It has relatively low risk combined with moderate cost and reasonable round-trip heat rate. It also has the potential for future growth options which tend to reduce costs and lower fuel consumption.

  19. Siting-selection study for the Soyland Power Cooperative, Inc. , compressed-air energy-storage system (CAES)

    Energy Technology Data Exchange (ETDEWEB)

    1982-01-01

    A method used for siting a compressed air energy storage (CAES) system using geotechnical and environmental criteria is explained using the siting of a proposed 220 MW water-compensated CAES plant in Illinois as an example. Information is included on the identification and comparative ranking of 28 geotechnically and environmental sites in Illinois, the examination of fatal flaws, e.g., mitigation, intensive studies, costly studies, permit denials, at 7 sites; and the selection of 3 sites for further geological surveying. (LCL)

  20. Modelling and analysis of a novel compressed air energy storage system for trigeneration based on electrical energy peak load shifting

    International Nuclear Information System (INIS)

    Lv, Song; He, Wei; Zhang, Aifeng; Li, Guiqiang; Luo, Bingqing; Liu, Xianghua

    2017-01-01

    Highlights: • A new CAES system for trigeneration based on electrical peak load shifting is proposed. • The theoretical models and the thermodynamics process are established and analyzed. • The relevant parameters influencing its performance have been discussed and optimized. • A novel energy and economic evaluation methods is proposed to evaluate the performance of the system. - Abstract: The compressed air energy storage (CAES) has made great contribution to both electricity and renewable energy. In the pursuit of reduced energy consumption and relieving power utility pressure effectively, a novel trigeneration system based on CAES for cooling, heating and electricity generation by electrical energy peak load shifting is proposed in this paper. The cooling power is generated by the direct expansion of compressed air, and the heating power is recovered in the process of compression and storage. Based on the working principle of the typical CAES, the theoretical analysis of the thermodynamic system models are established and the characteristics of the system are analyzed. A novel method used to evaluate energy and economic performance is proposed. A case study is conducted, and the economic-social and technical feasibility of the proposed system are discussed. The results show that the trigeneration system works efficiently at relatively low pressure, and the efficiency is expected to reach about 76.3% when air is compressed and released by 15 bar. The annual monetary cost saving annually is about 53.9%. Moreover, general considerations about the proposed system are also presented.

  1. Petrologic and petrophysical evaluation of the Dallas Center Structure, Iowa, for compressed air energy storage in the Mount Simon Sandstone.

    Energy Technology Data Exchange (ETDEWEB)

    Heath, Jason E.; Bauer, Stephen J.; Broome, Scott Thomas; Dewers, Thomas A.; Rodriguez, Mark A

    2013-03-01

    The Iowa Stored Energy Plant Agency selected a geologic structure at Dallas Center, Iowa, for evaluation of subsurface compressed air energy storage. The site was rejected due to lower-than-expected and heterogeneous permeability of the target reservoir, lower-than-desired porosity, and small reservoir volume. In an initial feasibility study, permeability and porosity distributions of flow units for the nearby Redfield gas storage field were applied as analogue values for numerical modeling of the Dallas Center Structure. These reservoir data, coupled with an optimistic reservoir volume, produced favorable results. However, it was determined that the Dallas Center Structure cannot be simplified to four zones of high, uniform permeabilities. Updated modeling using field and core data for the site provided unfavorable results for air fill-up. This report presents Sandia National Laboratories petrologic and petrophysical analysis of the Dallas Center Structure that aids in understanding why the site was not suitable for gas storage.

  2. Numerical simulation for the coupled thermo-mechanical performance of a lined rock cavern for underground compressed air energy storage

    Science.gov (United States)

    Zhou, Shu-Wei; Xia, Cai-Chu; Zhao, Hai-Bin; Mei, Song-Hua; Zhou, Yu

    2017-12-01

    Compressed air energy storage (CAES) is a technology that uses compressed air to store surplus electricity generated from low power consumption time for use at peak times. This paper presents a thermo-mechanical modeling for the thermodynamic and mechanical responses of a lined rock cavern used for CAES. The simulation was accomplished in COMSOL Multiphysics and comparisons of the numerical simulation and some analytical solutions validated the thermo-mechanical modeling. Air pressure and temperatures in the sealing layer and concrete lining exhibited a similar trend of ‘up-down-down-up’ in one cycle. Significant temperature fluctuation occurred only in the concrete lining and sealing layer, and no strong fluctuation was observed in the host rock. In the case of steel sealing, principal stresses in the sealing layer were larger than those in the concrete and host rock. The maximum compressive stresses of the three layers and the displacement on the cavern surface increased with the increase of cycle number. However, the maximum tensile stresses exhibited the opposite trend. Polymer sealing achieved a relatively larger air temperature and pressure compared with steel and air-tight concrete sealing. For concrete layer thicknesses of 0 and 0.1 m and an initial air pressure of 4.5 MPa, the maximum rock temperature could reach 135 °C and 123 °C respectively in a 30 day simulation.

  3. Thermo-Economic Comparison and Parametric Optimizations among Two Compressed Air Energy Storage System Based on Kalina Cycle and ORC

    Directory of Open Access Journals (Sweden)

    Ruixiong Li

    2016-12-01

    Full Text Available The compressed air energy storage (CAES system, considered as one method for peaking shaving and load-levelling of the electricity system, has excellent characteristics of energy storage and utilization. However, due to the waste heat existing in compressed air during the charge stage and exhaust gas during the discharge stage, the efficient operation of the conventional CAES system has been greatly restricted. The Kalina cycle (KC and organic Rankine cycle (ORC have been proven to be two worthwhile technologies to fulfill the different residual heat recovery for energy systems. To capture and reuse the waste heat from the CAES system, two systems (the CAES system combined with KC and ORC, respectively are proposed in this paper. The sensitivity analysis shows the effect of the compression ratio and the temperature of the exhaust on the system performance: the KC-CAES system can achieve more efficient operation than the ORC-CAES system under the same temperature of exhaust gas; meanwhile, the larger compression ratio can lead to the higher efficiency for the KC-CAES system than that of ORC-CAES with the constant temperature of the exhaust gas. In addition, the evolutionary multi-objective algorithm is conducted between the thermodynamic and economic performances to find the optimal parameters of the two systems. The optimum results indicate that the solutions with an exergy efficiency of around 59.74% and 53.56% are promising for KC-CAES and ORC-CAES system practical designs, respectively.

  4. Preliminary analytical study on the feasibility of using reinforced concrete pile foundations for renewable energy storage by compressed air energy storage technology

    Science.gov (United States)

    Tulebekova, S.; Saliyev, D.; Zhang, D.; Kim, J. R.; Karabay, A.; Turlybek, A.; Kazybayeva, L.

    2017-11-01

    Compressed air energy storage technology is one of the promising methods that have high reliability, economic feasibility and low environmental impact. Current applications of the technology are mainly limited to energy storage for power plants using large scale underground caverns. This paper explores the possibility of making use of reinforced concrete pile foundations to store renewable energy generated from solar panels or windmills attached to building structures. The energy will be stored inside the pile foundation with hollow sections via compressed air. Given the relatively small volume of storage provided by the foundation, the required storage pressure is expected to be higher than that in the large-scale underground cavern. The high air pressure typically associated with large temperature increase, combined with structural loads, will make the pile foundation in a complicated loading condition, which might cause issues in the structural and geotechnical safety. This paper presents a preliminary analytical study on the performance of the pile foundation subjected to high pressure, large temperature increase and structural loads. Finite element analyses on pile foundation models, which are built from selected prototype structures, have been conducted. The analytical study identifies maximum stresses in the concrete of the pile foundation under combined pressure, temperature change and structural loads. Recommendations have been made for the use of reinforced concrete pile foundations for renewable energy storage.

  5. Thermodynamic analysis of a novel tri-generation system based on compressed air energy storage and pneumatic motor

    International Nuclear Information System (INIS)

    Liu, Jin-Long; Wang, Jian-Hua

    2015-01-01

    Based on CAES (compressed air energy storage) and PM (pneumatic motor), a novel tri-generation system (heat energy, mechanical energy and cooling power) is proposed in this paper. Both the cheap electricity generated at night and the excess power from undelivered renewable energy due to instability, can be stored as compressed air and hot water by the proposed system. When energy is in great demand, the compressed air stored in this system is released to drive PM to generate mechanical power. The discharged air from PM can be further utilized as valuable cooling power. Compared to conventional CAES systems, the biggest characteristic of the proposed system is that the discharged air usually abandoned is used as cooling power. In order to study the performances of this system, a thermodynamic analysis and an experimental investigation are carried out. The thermodynamic model is validated by the experimental data. Using the validated thermodynamic model, the mechanical energy output, cooling capacity and temperature of discharged air, as well as the efficiency of the system are analyzed. The theoretical analysis indicates that the additional application of discharged air can improve total energy efficiency by 20–30%. Therefore, this system is very worthy of consideration and being popularized. - Highlights: • The proposed system can provide mechanical energy, heat energy and cooling power. • The exhaust air of pneumatic motor is used as cooling power instead of abandoned. • A thermodynamic model of the proposed system is constructed and validated. • The effects of several parameters on system performance are examined. • The proposed system can improve total energy efficiency of CAES system by 20–30%.

  6. Optimization of diesel engine performances for a hybrid wind-diesel system with compressed air energy storage

    International Nuclear Information System (INIS)

    Ibrahim, H.; Younes, R.; Basbous, T.; Ilinca, A.; Dimitrova, M.

    2011-01-01

    Electricity supply in remote areas around the world is mostly guaranteed by diesel generators. This relatively inefficient and expensive method is responsible for 1.2 million tons of greenhouse gas (GHG) emission in Canada annually. Some low- and high-penetration wind-diesel hybrid systems (WDS) have been experimented in order to reduce the diesel consumption. We explore the re-engineering of current diesel power plants with the introduction of high-penetration wind systems together with compressed air energy storage (CAES). This is a viable alternative to major the overall percentage of renewable energy and reduce the cost of electricity. In this paper, we present the operative principle of this hybrid system, its economic benefits and advantages and we finally propose a numerical model of each of its components. Moreover, we are demonstrating the energy efficiency of the system, particularly in terms of the increase of the engine performance and the reduction of its fuel consumption illustrated and supported by a village in northern Quebec. -- Highlights: → The Wind-Diesel-Compressed Air Storage System (WDCAS) has a very important commercial potential for remote areas. → The WDCAS is conceived like the adaptation of the existing engines at the level of the intake system. → A wind turbine and an air compression and storage system are added on the diesel plant. → This study demonstrates the potential of WDCAS to reduce fuel consumption and increase the efficiency of the diesel engine. → This study demonstrates that we can expect savings which can reach 50%.

  7. Storage of compressed air. A possibility for an enhanced utilization of wind energy?; Druckluftspeicherung. Ein Weg zur verstaerkten Windenergienutzung?

    Energy Technology Data Exchange (ETDEWEB)

    Kretschmer, Rutger [DREWAG - Stadtwerke Dresden GmbH, Dresden (Germany). Hauptabt. Vertrieb und Beschaffung

    2008-07-01

    The high prices for fossil energy sources are due to increasing demand, limited production quotas and exhaustion of strategically positioned deposits. Likewise the electricity prices increase to. High electricity tariffs improve the investment climate for renewable energies independently from the fuel costs. The positive development of the renewable energy is accompanied by serious disadvantages. Thus, the conditions for grid control and for the operation of fossil power stations deteriorate. The author of the contribution under consideration reports on the storage of compressed air as a possibility for the use of wind energy.

  8. Modelling study, efficiency analysis and optimisation of large-scale Adiabatic Compressed Air Energy Storage systems with low-temperature thermal storage

    International Nuclear Information System (INIS)

    Luo, Xing; Wang, Jihong; Krupke, Christopher; Wang, Yue; Sheng, Yong; Li, Jian; Xu, Yujie; Wang, Dan; Miao, Shihong; Chen, Haisheng

    2016-01-01

    Highlights: • The paper presents an A-CAES system thermodynamic model with low temperature thermal energy storage integration. • The initial parameter value ranges for A-CAES system simulation are identified from the study of a CAES plant in operation. • The strategies of system efficiency improvement are investigated via a parametric study with a sensitivity analysis. • Various system configurations are discussed for analysing the efficiency improvement potentials. - Abstract: The key feature of Adiabatic Compressed Air Energy Storage (A-CAES) is the reuse of the heat generated from the air compression process at the stage of air expansion. This increases the complexity of the whole system since the heat exchange and thermal storage units must have the capacities and performance to match the air compression/expansion units. Thus it raises a strong demand in the whole system modelling and simulation tool for A-CAES system optimisation. The paper presents a new whole system mathematical model for A-CAES with simulation implementation and the model is developed with consideration of lowing capital cost of the system. The paper then focuses on the study of system efficiency improvement strategies via parametric analysis and system structure optimisation. The paper investigates how the system efficiency is affected by the system component performance and parameters. From the study, the key parameters are identified, which give dominant influences in improving the system efficiency. The study is extended onto optimal system configuration and the recommendations are made for achieving higher efficiency, which provides a useful guidance for A-CAES system design.

  9. Water coning in porous media reservoirs for compressed air energy storage

    Energy Technology Data Exchange (ETDEWEB)

    Wiles, L.E.; McCann, R.A.

    1981-06-01

    The general purpose of this work is to define the hydrodynamic and thermodynamic response of a CAES porous media reservoir subjected to simulated air mass cycling. This research will assist in providing design guidelines for the efficient and stable operation of the air storage reservoir. This report presents the analysis and results for the two-phase (air-water), two-dimensional, numerical modeling of CAES porous media reservoirs. The effects of capillary pressure and relative permeability were included. The fluids were considered to be immisicible; there was no phase change; and the system was isothermal. The specific purpose of this analysis was to evaluate the reservoir parameters that were believed to be important to water coning. This phenomenon may occur in reservoirs in which water underlies the air storage zone. It involves the possible intrusion of water into the wellbore or near-wellbore region. The water movement is in response to pressure gradients created during a reservoir discharge cycle. Potential adverse effects due to this water movement are associated with the pressure response of the reservoir and the geochemical stability of the near-wellbore region. The results obtained for the simulated operation of a CAES reservoir suggest that water coning should not be a severe problem, due to the slow response of the water to the pressure gradients and the relatively short duration in which those gradients exist. However, water coning will depend on site-specific conditions, particularly the fluid distributions following bubble development, and, therefore, a water coning analysis should be included as part of site evaluation.

  10. Preliminary feasibility evalution of compressed air storage power systems. Volume II. Appendices, period June 1975--December 1976

    Energy Technology Data Exchange (ETDEWEB)

    1976-12-01

    Interest in compressed air storage has been developing in Sweden, Finland, Denmark, England, and France, as well as the United States. One commercial unit is under construction in Huntorf, West Germany. Compressed air for peak power can be stored either in natural or man-made caverns. Only new excavations in hard rock down to depths of about 2500 feet are considered in this report. In 1974, conditions for underground storage were discussed in a Geological Survey of Potential Cavern Areas in New England, referred to as the CAINE report. In this survey of the northeast region, the rest of the corridor between Washington and Boston has been added. The rock formations in the entire area of about 45,000 square miles are evaluated. The physical properties of rocks and criteria for their evaluation in underground openings are discussed. Methods of rock excavation and the basis for selecting areas are considered. Information on bedrock units along the corridor is reviewed. A list of favorable rock formations is included.

  11. Study and design of a hybrid wind-diesel-compressed air energy storage system for remote areas

    International Nuclear Information System (INIS)

    Ibrahim, H.; Younes, R.; Ilinca, A.; Dimitrova, M.; Perron, J.

    2010-01-01

    Remote areas around the world predominantly rely on diesel-powered generators for their electricity supply, a relatively expensive and inefficient technology that is responsible for the emission of 1.2 million tons of greenhouse gas (GHG) annually, only in Canada . Wind-diesel hybrid systems (WDS) with various penetration rates have been experimented to reduce diesel consumption of the generators. After having experimented wind-diesel hybrid systems (WDS) that used various penetration rates, we turned our focus to that the re-engineering of existing diesel power plants can be achieved most efficiently, in terms of cost and diesel consumption, through the introduction of high penetration wind systems combined with compressed air energy storage (CAES). This article compares the available technical alternatives to supercharge the diesel that was used in this high penetration wind-diesel system with compressed air storage (WDCAS), in order to identify the one that optimizes its cost and performances. The technical characteristics and performances of the best candidate technology are subsequently assessed at different working regimes in order to evaluate the varying effects on the system. Finally, a specific WDCAS system with diesel engine downsizing is explored. This proposed design, that requires the repowering of existing facilities, leads to heightened diesel power output, increased engine lifetime and efficiency and to the reduction of fuel consumption and GHG emissions, in addition to savings on maintenance and replacement cost.

  12. Exploring the concept of compressed air energy storage (CAES) in lined rock caverns at shallow depth: A modeling study of air tightness and energy balance

    International Nuclear Information System (INIS)

    Kim, Hyung-Mok; Rutqvist, Jonny; Ryu, Dong-Woo; Choi, Byung-Hee; Sunwoo, Choon; Song, Won-Kyong

    2012-01-01

    Highlights: ► We carried out coupled thermodynamic, multiphase fluid flow and heat transport analysis. ► Coupled behavior associated with underground lined caverns for CAES was investigated. ► Air leakage could be reduced by controlling the permeability of concrete lining. ► Heat loss during compression would be gained back at subsequent decompression phase. -- Abstract: This paper presents a numerical modeling study of coupled thermodynamic, multiphase fluid flow and heat transport associated with underground compressed air energy storage (CAES) in lined rock caverns. Specifically, we explored the concept of using concrete lined caverns at a relatively shallow depth for which constructing and operation costs may be reduced if air tightness and stability can be assured. Our analysis showed that the key parameter to assure long-term air tightness in such a system was the permeability of both the concrete lining and the surrounding rock. The analysis also indicated that a concrete lining with a permeability of less than 1 × 10 −18 m 2 would result in an acceptable air leakage rate of less than 1%, with the operation pressure range between 5 and 8 MPa at a depth of 100 m. It was further noted that capillary retention properties and the initial liquid saturation of the lining were very important. Indeed, air leakage could be effectively prevented when the air-entry pressure of the concrete lining is higher than the operation air pressure and when the lining is kept at relatively high moisture content. Our subsequent energy-balance analysis demonstrated that the energy loss for a daily compression and decompression cycle is governed by the air-pressure loss, as well as heat loss by conduction to the concrete liner and surrounding rock. For a sufficiently tight system, i.e., for a concrete permeability of less than 1 × 10 −18 m 2 , heat loss by heat conduction tends to become proportionally more important. However, the energy loss by heat conduction can be

  13. Exploring the concept of compressed air energy storage (CAES) in lined rock caverns at shallow depth: A modeling study of air tightness and energy balance

    Energy Technology Data Exchange (ETDEWEB)

    Kim, H.-M.; Rutqvist, J.; Ryu, D.-W.; Choi, B.-H.; Sunwoo, C.; Song, W.-K.

    2011-07-15

    This paper presents a numerical modeling study of coupled thermodynamic, multiphase fluid flow and heat transport associated with underground compressed air energy storage (CAES) in lined rock caverns. Specifically, we explored the concept of using concrete lined caverns at a relatively shallow depth for which constructing and operational costs may be reduced if air tightness and stability can be assured. Our analysis showed that the key parameter to assure long-term air tightness in such a system was the permeability of both the concrete lining and the surrounding rock. The analysis also indicated that a concrete lining with a permeability of less than 1×10{sup -18} m{sup 2} would result in an acceptable air leakage rate of less than 1%, with the operational pressure range between 5 and 8 MPa at a depth of 100 m. It was further noted that capillary retention properties and the initial liquid saturation of the lining were very important. Indeed, air leakage could be effectively prevented when the air-entry pressure of the concrete lining is higher than the operational air pressure and when the lining is kept moist at a relatively high liquid saturation. Our subsequent energy-balance analysis demonstrated that the energy loss for a daily compression and decompression cycle is governed by the air-pressure loss, as well as heat loss by conduction to the concrete liner and surrounding rock. For a sufficiently tight system, i.e., for a concrete permeability off less than 1×10{sup -18} m{sup 2}, heat loss by heat conduction tends to become proportionally more important. However, the energy loss by heat conduction can be minimized by keeping the air-injection temperature of compressed air closer to the ambient temperature of the underground storage cavern. In such a case, almost all the heat loss during compression is gained back during subsequent decompression. Finally, our numerical simulation study showed that CAES in shallow rock caverns is feasible from a leakage

  14. Techno-economic assessment of the need for bulk energy storage in low-carbon electricity systems with a focus on compressed air storage (CAES)

    Science.gov (United States)

    Safaei Mohamadabadi, Hossein

    Increasing electrification of the economy while decarbonizing the electricity supply is among the most effective strategies for cutting greenhouse gas (GHG) emissions in order to abate climate change. This thesis offers insights into the role of bulk energy storage (BES) systems to cut GHG emissions from the electricity sector. Wind and solar energies can supply large volumes of low-carbon electricity. Nevertheless, large penetration of these resources poses serious reliability concerns to the grid, mainly because of their intermittency. This thesis evaluates the performance of BES systems - especially compressed air energy storage (CAES) technology - for integration of wind energy from engineering and economic aspects. Analytical thermodynamic analysis of Distributed CAES (D-CAES) and Adiabatic CAES (A-CAES) suggest high roundtrip storage efficiencies ( 80% and 70%) compared to conventional CAES ( 50%). Using hydrogen to fuel CAES plants - instead of natural gas - yields a low overall efficiency ( 35%), despite its negligible GHG emissions. The techno-economic study of D-CAES shows that exporting compression heat to low-temperature loads (e.g. space heating) can enhance both the economic and emissions performance of compressed air storage plants. A case study for Alberta, Canada reveals that the abatement cost of replacing a conventional CAES with D-CAES plant practicing electricity arbitrage can be negative (-$40 per tCO2e, when the heat load is 50 km away from the air storage site). A green-field simulation finds that reducing the capital cost of BES - even drastically below current levels - does not substantially impact the cost of low-carbon electricity. At a 70% reduction in the GHG emissions intensity of the grid, gas turbines remain three times more cost-efficient in managing the wind variability compared to BES (in the best case and with a 15-minute resolution). Wind and solar thus, do not need to wait for availability of cheap BES systems to cost

  15. Storage of compressed air - Optimisation and measurement of an existing project example; Druckluftspeicherung: Optimierung / Ausmessung bestehendes Projektmuster

    Energy Technology Data Exchange (ETDEWEB)

    Brueckmann, P. [Brueckmann Elektronik, Davos Dorf (Switzerland); Cyphelly, I. [Cyphelly and Cie, Les Brenets (Switzerland)

    2007-06-15

    This short final report for the Swiss Federal Office of Energy (SFOE) deals with an additional project that augmented an earlier report on a compressed-air energy storage system. First tests are reported on that revealed that the chosen heat exchanger fulfils the thermal expectations with substantial reserves. Certain effects concerning the liquid piston system are described which showed that further development of the test infrastructure were required. This project was launched to further examine these problems. Difficulties with the liquids available which prohibited the intended exact series of measurements are commented on. The authors note that independent investigations by the Austrian company LINDE came to the same conclusions, thus confirming the function of the heat exchanger.

  16. System behaviour of compressed-air energy-storage in Denmark with a high penetration of renewable energy sources

    International Nuclear Information System (INIS)

    Salgi, Georges; Lund, Henrik

    2008-01-01

    In 2005, wind power supplied 19% of the 36 TWh annual electricity demand in Denmark, while 50% was produced at combined heat-and-power plants (CHP). The installed wind-turbine capacity in Western Denmark exceeds the local demand at certain points in time. So far, excess production has been exported to neighbouring countries. However, plans to expand wind power both in Denmark and in its neighbouring countries could restrain the export option and create transmission congestion challenges. This results in a need to increase the flexibility of the local electricity-system. Compressed-Air Energy-Storage (CAES) has been proposed as a potential solution for levelling fluctuating wind-power production and maintaining a system balance. This paper analyses the energy-balance effects of adding CAES to the Western Danish energy-system. Results show that even with an unlimited CAES plant capacity, excess power production is not eliminated because of the high percentage of CHP production. The optimal wind-power penetration for maximum CAES operation is found to be around 55%. The minimum storage size for CAES to fully eliminate condensing power plants operation in the optimized system is over 500 GWh, which corresponds to a cavern volume of around 234 Mm 3 at an average pressure of 60 bar. Such a storage size would be technically and economically unfeasible. The analysis, however, did not include the potential role of a CAES plant in regulating the power services. (author)

  17. Technical and economic assessment of fluidized-bed-augmented compressed-air energy-storage system: system load following capability

    Energy Technology Data Exchange (ETDEWEB)

    Lessard, R.D.; Blecher, W.A.; Merrick, D.

    1981-09-01

    The load-following capability of fluidized bed combustion-augmented compressed air energy storage systems was evaluated. The results are presented in two parts. The first part is an Executive Summary which provides a concise overview of all major elements of the study including the conclusions, and, second, a detailed technical report describing the part-load and load following capability of both the pressurized fluid bed combustor and the entire pressurized fluid bed combustor/compressed air energy storage system. The specific tasks in this investigation were to: define the steady-state, part-load operation of the CAES open-bed PFBC; estimate the steady-state, part-load performance of the PFBC/CAES system and evaluate any possible operational constraints; simulate the performance of the PFBC/CAES system during transient operation and assess the load following capability of the system; and establish a start-up procedure for the open-bed PFBC and evaluate the impact of this procedure. The conclusions are encouraging and indicate that the open-bed PFBC/CAES power plant should provide good part-load and transient performance, and should have no major equipment-related constraints, specifically, no major problems associated with the performance or design of either the open-end PFBC or the PFBC/CAES power plant in steady-state, part-load operation are envisioned. The open-bed PFBC/CAES power plant would have a load following capability which would be responsive to electric utility requirements for a peak-load power plant. The open-bed PFBC could be brought to full operating conditions within 15 min after routine shutdown, by employing a hot-start mode of operation. The PFBC/CAES system would be capable of rapid changes in output power (12% of design load per minute) over a wide output power range (25% to 100% of design output). (LCL)

  18. Lessons from Iowa : development of a 270 megawatt compressed air energy storage project in midwest Independent System Operator : a study for the DOE Energy Storage Systems Program.

    Energy Technology Data Exchange (ETDEWEB)

    Holst, Kent (Iowa Stored Energy Plant Agency, Traer, IA); Huff, Georgianne; Schulte, Robert H. (Schulte Associates LLC, Northfield, MN); Critelli, Nicholas (Critelli Law Office PC, Des Moines, IA)

    2012-01-01

    The Iowa Stored Energy Park was an innovative, 270 Megawatt, $400 million compressed air energy storage (CAES) project proposed for in-service near Des Moines, Iowa, in 2015. After eight years in development the project was terminated because of site geological limitations. However, much was learned in the development process regarding what it takes to do a utility-scale, bulk energy storage facility and coordinate it with regional renewable wind energy resources in an Independent System Operator (ISO) marketplace. Lessons include the costs and long-term economics of a CAES facility compared to conventional natural gas-fired generation alternatives; market, legislative, and contract issues related to enabling energy storage in an ISO market; the importance of due diligence in project management; and community relations and marketing for siting of large energy projects. Although many of the lessons relate to CAES applications in particular, most of the lessons learned are independent of site location or geology, or even the particular energy storage technology involved.

  19. Characterizing Excavation Damaged Zone and Stability of Pressurized Lined Rock Caverns for Underground Compressed Air Energy Storage

    Science.gov (United States)

    Kim, Hyung-Mok; Rutqvist, Jonny; Jeong, Ju-Hwan; Choi, Byung-Hee; Ryu, Dong-Woo; Song, Won-Kyong

    2013-09-01

    In this paper, we investigate the influence of the excavation damaged zone (EDZ) on the geomechanical performance of compressed air energy storage (CAES) in lined rock caverns. We conducted a detailed characterization of the EDZ in rock caverns that have been excavated for a Korean pilot test program on CAES in (concrete) lined rock caverns at shallow depth. The EDZ was characterized by measurements of P- and S-wave velocities and permeability across the EDZ and into undisturbed host rock. Moreover, we constructed an in situ concrete lining model and conducted permeability measurements in boreholes penetrating the concrete, through the EDZ and into the undisturbed host rock. Using the site-specific conditions and the results of the EDZ characterization, we carried out a model simulation to investigate the influence of the EDZ on the CAES performance, in particular related to geomechanical responses and stability. We used a modeling approach including coupled thermodynamic multiphase flow and geomechanics, which was proven to be useful in previous generic CAES studies. Our modeling results showed that the potential for inducing tensile fractures and air leakage through the concrete lining could be substantially reduced if the EDZ around the cavern could be minimized. Moreover, the results showed that the most favorable design for reducing the potential for tensile failure in the lining would be a relatively compliant concrete lining with a tight inner seal, and a relatively stiff (uncompliant) host rock with a minimized EDZ. Because EDZ compliance depends on its compressibility (or modulus) and thickness, care should be taken during drill and blast operations to minimize the damage to the cavern walls.

  20. Development of a Numerical Approach to Simulate Compressed Air Energy Storage Subjected to Cyclic Internal Pressure

    Directory of Open Access Journals (Sweden)

    Song-Hun Chong

    2017-10-01

    Full Text Available This paper analyzes the long-term response of unlined energy storage located at shallow depth to improve the distance between a wind farm and storage. The numerical approach follows the hybrid scheme that combined a mechanical constitutive model to extract stress and strains at the first cycle and polynomial-type strain accumulation functions to track the progressive plastic deformation. In particular, the strain function includes the fundamental features that requires simulating the long-term response of geomaterials: volumetric strain (terminal void ratio and shear strain (shakedown and ratcheting, the strain accumulation rate, and stress obliquity. The model is tested with a triaxial strain boundary condition under different stress obliquities. The unlined storage subjected to cyclic internal stress is simulated with different storage geometries and stress amplitudes that play a crucial role in estimating the long-term mechanical stability of underground storage. The simulations present the evolution of ground surface, yet their incremental rate approaches towards a terminal void ratio. With regular and smooth displacement fields for the large number of cycles, the inflection point is estimated with the previous surface settlement model.

  1. Controllable and affordable utility-scale electricity from intermittent wind resources and compressed air energy storage (CAES)

    International Nuclear Information System (INIS)

    Cavallo, Alfred

    2007-01-01

    World wind energy resources are substantial, and in many areas, such as the US and northern Europe, could in theory supply all of the electricity demand. However, the remote or challenging location (i.e. offshore) and especially the intermittent character of the wind resources present formidable barriers to utilization on the scale required by a modern industrial economy. All of these technical challenges can be overcome. Long distance transmission is well understood, while offshore wind technology is being developed rapidly. Intermittent wind power can be transformed to a controllable power source with hybrid wind/compressed air energy storage (CAES) systems. The cost of electricity from such hybrid systems (including transmission) is affordable, and comparable to what users in some modern industrial economies already pay for electricity. This approach to intermittent energy integration has many advantages compared to the current strategy of forcing utilities to cope with supply uncertainty and transmission costs. Above all, it places intermittent wind on an equal technical footing with every other generation technology, including nuclear power, its most important long-term competitor

  2. Design and thermodynamic analysis of a hybrid energy storage system based on A-CAES (adiabatic compressed air energy storage) and FESS (flywheel energy storage system) for wind power application

    International Nuclear Information System (INIS)

    Zhao, Pan; Dai, Yiping; Wang, Jiangfeng

    2014-01-01

    Electricity generated from renewable wind sources is highly erratic due to the intermittent nature of wind. This uncertainty of wind power can lead to challenges regarding power system operation and dispatch. Energy storage system in conjunction with wind energy system can offset these effects, making the wind power controllable. Moreover, the power spectrum of wind power exhibits that the fluctuations of wind power include various components with different frequencies and amplitudes. Thus, the hybrid energy storage system is more suitable for smoothing out the wind power fluctuations effectively rather than the independent energy storage system. A hybrid energy storage system consisting of adiabatic compressed air energy storage (A-CAES) system and flywheel energy storage system (FESS) is proposed for wind energy application. The design of the proposed system is laid out firstly. The A-CAES system operates in variable cavern pressure, constant turbine inlet pressure mode, whereas the FESS is controlled by constant power strategy. Then, the off-design analysis of the proposed system is carried out. Meanwhile, a parametric analysis is also performed to investigate the effects of several parameters on the system performance, including the ambient conditions, inlet temperature of compressor, storage cavern temperature, maximum and minimum pressures of storage cavern. - Highlights: • A wind-hybrid energy storage system composed of A-CAES and FESS is proposed. • The design of the proposed hybrid energy storage system is laid out. • The off-design analysis of the proposed system is carried out. • A parametric analysis is conducted to examine the system performance

  3. Reservoir characterization and final pre-test analysis in support of the compressed-air-energy-storage Pittsfield aquifer field test in Pike County, Illinois

    Energy Technology Data Exchange (ETDEWEB)

    Wiles, L.E.; McCann, R.A.

    1983-06-01

    The work reported is part of a field experimental program to demonstrate and evaluate compressed air energy storage in a porous media aquifer reservoir near Pittsfield, Illinois. The reservoir is described. Numerical modeling of the reservoir was performed concurrently with site development. The numerical models were applied to predict the thermohydraulic performance of the porous media reservoir. This reservoir characterization and pre-test analysis made use of evaluation of bubble development, water coning, thermal development, and near-wellbore desaturation. The work was undertaken to define the time required to develop an air storage bubble of adequate size, to assess the specification of instrumentation and above-ground equipment, and to develop and evaluate operational strategies for air cycling. A parametric analysis was performed for the field test reservoir. (LEW)

  4. Baseload wind energy: modeling the competition between gas turbines and compressed air energy storage for supplemental generation

    International Nuclear Information System (INIS)

    Greenblatt, Jeffery B.; Succar, Samir; Denkenberger, David C.; Williams, Robert H.; Socolow, Robert H.

    2007-01-01

    The economic viability of producing baseload wind energy was explored using a cost-optimization model to simulate two competing systems: wind energy supplemented by simple- and combined cycle natural gas turbines ('wind+gas'), and wind energy supplemented by compressed air energy storage ('wind+CAES'). Pure combined cycle natural gas turbines ('gas') were used as a proxy for conventional baseload generation. Long-distance electric transmission was integral to the analysis. Given the future uncertainty in both natural gas price and greenhouse gas (GHG) emissions price, we introduced an effective fuel price, p NGeff , being the sum of the real natural gas price and the GHG price. Under the assumption of p NGeff =$5/GJ (lower heating value), 650 W/m 2 wind resource, 750 km transmission line, and a fixed 90% capacity factor, wind+CAES was the most expensive system at cents 6.0/kWh, and did not break even with the next most expensive wind+gas system until p NGeff =$9.0/GJ. However, under real market conditions, the system with the least dispatch cost (short-run marginal cost) is dispatched first, attaining the highest capacity factor and diminishing the capacity factors of competitors, raising their total cost. We estimate that the wind+CAES system, with a greenhouse gas (GHG) emission rate that is one-fourth of that for natural gas combined cycle plants and about one-tenth of that for pulverized coal plants, has the lowest dispatch cost of the alternatives considered (lower even than for coal power plants) above a GHG emissions price of $35/tC equiv. , with good prospects for realizing a higher capacity factor and a lower total cost of energy than all the competing technologies over a wide range of effective fuel costs. This ability to compete in economic dispatch greatly boosts the market penetration potential of wind energy and suggests a substantial growth opportunity for natural gas in providing baseload power via wind+CAES, even at high natural gas prices

  5. Microbiological contamination of compressed air used in dentistry: an investigation.

    Science.gov (United States)

    Conte, M; Lynch, R M; Robson, M G

    2001-11-01

    The purpose of this preliminary investigation was twofold: 1) to examine the possibility of cross-contamination between a dental-evacuation system and the compressed air used in dental operatories and 2) to capture and identify the most common microflora in the compressed-air supply. The investigation used swab, water, and air sampling that was designed to track microorganisms from the evacuation system, through the air of the mechanical room, into the compressed-air system, and back to the patient. Samples taken in the vacuum system, the air space in the mechanical room, and the compressed-air storage tank had significantly higher total concentrations of bacteria than the outside air sampled. Samples of the compressed air returning to the operatory were found to match the outside air sample in total bacteria. It was concluded that the air dryer may have played a significant role in the elimination of microorganisms from the dental compressed-air supply.

  6. Experiments on hydraulically-compensated Compressed Air Energy Storage (CAES) system using large-diameter vertical pipe two-phase flow test facility: test facility and test procedure

    International Nuclear Information System (INIS)

    Ohtsu, Iwao; Murata, Hideo; Kukita, Yutaka; Kumamaru, Hiroshige.

    1996-07-01

    JAERI, the University of Tokyo, the Central Research Institute of Electric Power Industry and Shimizu Corporation jointing performed and experimental study on two-phase flow in the hydraulically-compensated Compressed Air Energy Storage (CAES) system with a large-diameter vertical pipe two-phase flow test facility from 1993 to 1995. A hydraulically-compensated CAES system is a proposed, conceptual energy storage system where energy is stored in the form of compressed air in an underground cavern which is sealed by a deep (several hundred meters) water shaft. The shaft water head maintains a constant pressure in the cavern, of several mega Pascals, even during loading or unloading of the cavern with air. The dissolved air in the water, however, may create voids in the shaft when the water rises through the shaft during the loading, being forced by the air flow into the cavern. The voids may reduce the effective head of the shaft, and thus the seal may fail, if significant bubbling should occur in the shaft. This bubbling phenomenon (termed 'Champaign effect') and potential failure of the water seal ('blowout') are simulated in a scaled-height, scaled-diameter facility. Carbon dioxide is used to simulate high solubility of air in the full-height, full-pressure system. This report describes the expected and potential two-phase flow phenomena in a hydraulically-compensated CAES system, the test facility and the test procedure, a method to estimate quantities which are not directly measured by using measured quantities and hydrodynamic basic equations, and desirable additional instrumentation. (author)

  7. Present situation of the electric power storage technology and its future outlook. IV. ; Compressed air energy storage. Denryoku Chozo gijutsu no genjo to shorai tenbo ni tsuibe. IV. ; Asshuku kuki chozo

    Energy Technology Data Exchange (ETDEWEB)

    Kadoyu, M. (Central Research Institute of Electric Power Industry, Tokyo (Japan))

    1991-03-20

    The compressed air energy storage gas turbine power generation system is paid attetion to as a load levelling power source in view of the recent increase in electric power demand. The paper describes features, cavern construction technology, economy and future expansion of the system. In this system compressed air made by use of cheap night-time electric power is stored in underground spaces or underwater facilities. Burning the fuel together with this compressed air in the daytime, the gas turbine power generation is conducted. Several examples overseas of this system are reported including a 290,000KW class in Germany. A key technology of the system is how safely and cheaply a large amount of hih-pressure air can be stored. In Europe and America, caverns of hundreds of thousand m {sub 3} are constructed in the rock salt cavern which can be excavated by a water jet. In consideration of storing it in rock beds in Japan where there are no rock salt caverns, NEDO started 1990 a 9-year construction plan of a 35,000 KW class pilot plant at Kamisunagawa, Hokkaido. 2 refs., 5 figs., 1 tab.

  8. 29 CFR 1917.154 - Compressed air.

    Science.gov (United States)

    2010-07-01

    ... 29 Labor 7 2010-07-01 2010-07-01 false Compressed air. 1917.154 Section 1917.154 Labor Regulations...) MARINE TERMINALS Related Terminal Operations and Equipment § 1917.154 Compressed air. Employees shall be... this part during cleaning with compressed air. Compressed air used for cleaning shall not exceed a...

  9. Rectal perforation by compressed air.

    Science.gov (United States)

    Park, Young Jin

    2017-07-01

    As the use of compressed air in industrial work has increased, so has the risk of associated pneumatic injury from its improper use. However, damage of large intestine caused by compressed air is uncommon. Herein a case of pneumatic rupture of the rectum is described. The patient was admitted to the Emergency Room complaining of abdominal pain and distension. His colleague triggered a compressed air nozzle over his buttock. On arrival, vital signs were stable but physical examination revealed peritoneal irritation and marked distension of the abdomen. Computed tomography showed a large volume of air in the peritoneal cavity and subcutaneous emphysema at the perineum. A rectal perforation was found at laparotomy and the Hartmann procedure was performed.

  10. A stochastic self-scheduling program for compressed air energy storage (CAES) of renewable energy sources (RESs) based on a demand response mechanism

    International Nuclear Information System (INIS)

    Ghalelou, Afshin Najafi; Fakhri, Alireza Pashaei; Nojavan, Sayyad; Majidi, Majid; Hatami, Hojat

    2016-01-01

    Highlights: • Optimal stochastic energy management of renewable energy sources (RESs) is proposed. • The compressed air energy storage (CAES) besides RESs is used in the presence of DRP. • Determination charge and discharge of CAES in order to reduce the expected operation cost. • Moreover, demand response program (DRP) is proposed to minimize the operation cost. • The uncertainty modeling of input data are considered in the proposed stochastic framework. - Abstract: In this paper, a stochastic self-scheduling of renewable energy sources (RESs) considering compressed air energy storage (CAES) in the presence of a demand response program (DRP) is proposed. RESs include wind turbine (WT) and photovoltaic (PV) system. Other energy sources are thermal units and CAES. The time-of-use (TOU) rate of DRP is considered in this paper. This DRP shifts the percentage of load from the expensive period to the cheap one in order to flatten the load curve and minimize the operation cost, consequently. The proposed objective function includes minimizing the operation costs of thermal unit and CAES, considering technical and physical constraints. The proposed model is formulated as mixed integer linear programming (MILP) and it is been solved using General Algebraic Modeling System (GAMS) optimization package. Furthermore, CAES and DRP are incorporated in the stochastic self-scheduling problem by a decision maker to reduce the expected operation cost. Meanwhile, the uncertainty models of market price, load, wind speed, temperature and irradiance are considered in the formulation. Finally, to assess the effects of DRP and CAES on self-scheduling problem, four case studies are utilized, and significant results were obtained, which indicate the validity of the proposed stochastic program.

  11. 30 CFR 75.1730 - Compressed air; general; compressed air systems.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Compressed air; general; compressed air systems... Compressed air; general; compressed air systems. (a) All pressure vessels shall be constructed, installed... Safety and Health district office. (b) Compressors and compressed-air receivers shall be equipped with...

  12. Mechanical stability of a salt cavern submitted to rapid pressure variations: Application to the underground storage of natural gas, compressed air and hydrogen

    International Nuclear Information System (INIS)

    Djizanne-Djakeun, Hippolyte

    2014-01-01

    Salt caverns used for the underground storage of large volumes of natural gas are in high demand given the ever-increasing energy needs. The storage of renewable energy is also envisaged in these salt caverns for example, storage of compressed air and hydrogen mass storage. In both cases, salt caverns are more solicited than before because they are subject to rapid injection and withdrawal rates. These new operating modes raise new mechanical problems, illustrated in particular by sloughing, and falling of overhanging blocks at cavern wall. Indeed, to the purely mechanical stress related to changes in gas pressure variations, repeated dozens of degrees Celsius of temperature variation are superimposed; causes in particular during withdrawal, additional tensile stresses whom may lead to fractures at cavern wall; whose evolution could be dangerous. The mechanical behavior of rock salt is known: it is elasto-viscoplastic, nonlinear and highly thermo sensitive. The existing rock salt constitutive laws and failures and damages criteria have been used to analyze the behavior of caverns under the effects of these new loading. The study deals with the thermo mechanics of rocks and helps to analyze the effects of these new operations modes on the structural stability of salt caverns. The approach was to firstly design and validate a thermodynamic model of the behavior of gas in the cavern. This model was used to analyze blowout in gas salt cavern. Then, with the thermo mechanical coupling, to analyze the effects of rapid withdrawal, rapid injection and daily cycles on the structural stability of caverns. At the experimental level, we sought the optimal conditions to the occurrence and the development of cracks on a pastille and a block of rock salt. The creep behavior of rock salt specimens in triaxial extension also was analyzed. (author)

  13. Compressed air energy storage: preliminary design and site development program in an aquifer. Final draft, Task 2: Volume 2 of 3. Characterize and explore potential sites and prepare research and development plan

    Energy Technology Data Exchange (ETDEWEB)

    None

    1980-12-01

    The characteristics of sites in Indiana and Illinois which are being investigated as potential sites for compressed air energy storage power plants are documented. These characteristics include geological considerations, economic factors, and environmental considerations. Extensive data are presented for 14 specific sites and a relative rating on the desirability of each site is derived. (LCL)

  14. Compressed Air Production Using Vehicle Suspension

    OpenAIRE

    Ninad Arun Malpure; Sanket Nandlal Bhansali

    2015-01-01

    Abstract Generally compressed air is produced using different types of air compressors which consumes lot of electric energy and is noisy. In this paper an innovative idea is put forth for production of compressed air using movement of vehicle suspension which normal is wasted. The conversion of the force energy into the compressed air is carried out by the mechanism which consists of the vehicle suspension system hydraulic cylinder Non-return valve air compressor and air receiver. We are co...

  15. Thermodynamic analysis of a compressed carbon dioxide energy storage system using two saline aquifers at different depths as storage reservoirs

    International Nuclear Information System (INIS)

    Liu, Hui; He, Qing; Borgia, Andrea; Pan, Lehua; Oldenburg, Curtis M.

    2016-01-01

    Highlights: • A compressed CO_2 energy storage system using two storage reservoirs is presented. • Compressed CO_2 energy storage density is higher than that of CAES. • The effects of storage reservoir pressure on the system performance are studied. - Abstract: Compressed air energy storage (CAES) is one of the leading large-scale energy storage technologies. However, low thermal efficiency and low energy storage density restrict its application. To improve the energy storage density, we propose a two-reservoir compressed CO_2 energy storage system. We present here thermodynamic and parametric analyses of the performance of an idealized two-reservoir CO_2 energy storage system under supercritical and transcritical conditions using a steady-state mathematical model. Results show that the transcritical compressed CO_2 energy storage system has higher round-trip efficiency and exergy efficiency, and larger energy storage density than the supercritical compressed CO_2 energy storage. However, the configuration of supercritical compressed CO_2 energy storage is simpler, and the energy storage densities of the two systems are both higher than that of CAES, which is advantageous in terms of storage volume for a given power rating.

  16. Coal-fuelled systems for peaking power with 100% CO2 capture through integration of solid oxide fuel cells with compressed air energy storage

    Science.gov (United States)

    Nease, Jake; Adams, Thomas A.

    2014-04-01

    In this study, a coal-fuelled integrated solid oxide fuel cell (SOFC) and compressed air energy storage (CAES) system in a load-following power production scenario is discussed. Sixteen SOFC-based plants with optional carbon capture and sequestration (CCS) and syngas shifting steps are simulated and compared to a state-of-the-art supercritical pulverised coal (SCPC) plant. Simulations are performed using a combination of MATLAB and Aspen Plus v7.3. It was found that adding CAES to a SOFC-based plant can provide load-following capabilities with relatively small effects on efficiencies (1-2% HHV depending on the system configuration) and levelized costs of electricity (∼0.35 ¢ kW-1 h-1). The load-following capabilities, as measured by least-squares metrics, show that this system may utilize coal and achieve excellent load-tracking that is not adversely affected by the inclusion of CCS. Adding CCS to the SOFC/CAES system reduces measurable direct CO2 emission to zero. A seasonal partial plant shutdown schedule is found to reduce fuel consumption by 9.5% while allowing for cleaning and maintenance windows for the SOFC stacks without significantly affecting the performance of the system (∼1% HHV reduction in efficiency). The SOFC-based systems with CCS are found to become economically attractive relative to SCPC above carbon taxes of 22 ton-1.

  17. Thermodynamic analysis of energy conversion and transfer in hybrid system consisting of wind turbine and advanced adiabatic compressed air energy storage

    International Nuclear Information System (INIS)

    Zhang, Yuan; Yang, Ke; Li, Xuemei; Xu, Jianzhong

    2014-01-01

    A simulation model consisting of wind speed, wind turbine and AA-CAES (advanced adiabatic compressed air energy storage) system is developed in this paper, and thermodynamic analysis on energy conversion and transfer in hybrid system is carried out. The impacts of stable wind speed and unstable wind speed on the hybrid system are analyzed and compared from the viewpoint of energy conversion and system efficiency. Besides, energy conversion relationship between wind turbine and AA-CAES system is investigated on the basis of process analysis. The results show that there are several different forms of energy in hybrid system, which have distinct conversion relationship. As to wind turbine, power coefficient determines wind energy utilization efficiency, and in AA-CAES system, it is compressor efficiency that mainly affects energy conversion efficiencies of other components. The strength and fluctuation of wind speed have a direct impact on energy conversion efficiencies of components of hybrid system, and within proper wind speed scope, the maximum of system efficiency could be expected. - Highlights: • A hybrid system consisting of wind, wind turbine and AA-CAES system is established. • Energy conversion in hybrid system with stable and unstable wind speed is analyzed. • Maximum efficiency of hybrid system can be reached within proper wind speed scope. • Thermal energy change in hybrid system is more sensitive to wind speed change. • Compressor efficiency can affect other efficiencies in AA-CAES system

  18. Energy Conservation In Compressed Air Systems

    International Nuclear Information System (INIS)

    Yusuf, I.Y.; Dewu, B.B.M.

    2004-01-01

    Compressed air is an essential utility that accounts for a substantial part of the electricity consumption (bill) in most industrial plants. Although the general saying Air is free of charge is not true for compressed air, the utility's cost is not accorded the rightful importance due to its by most industries. The paper will show that the cost of 1 unit of energy in the form of compressed air is at least 5 times the cost electricity (energy input) required to produce it. The paper will also provide energy conservation tips in compressed air systems

  19. Advanced compressed hydrogen fuel storage systems

    International Nuclear Information System (INIS)

    Jeary, B.

    2000-01-01

    Dynetek was established in 1991 by a group of private investors, and since that time efforts have been focused on designing, improving, manufacturing and marketing advanced compressed fuel storage systems. The primary market for Dynetek fuel systems has been Natural Gas, however as the automotive industry investigates the possibility of using hydrogen as the fuel source solution in Alternative Energy Vehicles, there is a growing demand for hydrogen storage on -board. Dynetek is striving to meet the needs of the industry, by working towards developing a fuel storage system that will be efficient, economical, lightweight and eventually capable of storing enough hydrogen to match the driving range of the current gasoline fueled vehicles

  20. Economic and environmental evaluation of compressed-air cars

    International Nuclear Information System (INIS)

    Creutzig, Felix; Kammen, Daniel M; Papson, Andrew; Schipper, Lee

    2009-01-01

    Climate change and energy security require a reduction in travel demand, a modal shift, and technological innovation in the transport sector. Through a series of press releases and demonstrations, a car using energy stored in compressed air produced by a compressor has been suggested as an environmentally friendly vehicle of the future. We analyze the thermodynamic efficiency of a compressed-air car powered by a pneumatic engine and consider the merits of compressed air versus chemical storage of potential energy. Even under highly optimistic assumptions the compressed-air car is significantly less efficient than a battery electric vehicle and produces more greenhouse gas emissions than a conventional gas-powered car with a coal intensive power mix. However, a pneumatic-combustion hybrid is technologically feasible, inexpensive and could eventually compete with hybrid electric vehicles.

  1. Recoil Experiments Using a Compressed Air Cannon

    Science.gov (United States)

    Taylor, Brett

    2006-01-01

    Ping-Pong vacuum cannons, potato guns, and compressed air cannons are popular and dramatic demonstrations for lecture and lab. Students enjoy them for the spectacle, but they can also be used effectively to teach physics. Recently we have used a student-built compressed air cannon as a laboratory activity to investigate impulse, conservation of…

  2. Rupture of esophagus by compressed air.

    Science.gov (United States)

    Wu, Jie; Tan, Yuyong; Huo, Jirong

    2016-11-01

    Currently, beverages containing compressed air such as cola and champagne are widely used in our daily life. Improper ways to unscrew the bottle, usually by teeth, could lead to an injury, even a rupture of the esophagus. This letter to editor describes a case of esophageal rupture caused by compressed air.

  3. Development of fundamental technigue of compressed air energy storage (CAES) gas turbine power generation and resistivity tomography. Asshuku kuki chozo (CAES) gas turbine hatsuden no kiban gijutsu no kaihatsu to hiteiko tomography

    Energy Technology Data Exchange (ETDEWEB)

    Hibino, S; Suzuki, K [Central Research Inst. of Electric Power Industry, Tokyo (Japan)

    1991-12-01

    Compressed air energy storage (CAES) has been studied as a promising storage system which has a good possibility of being put to practical use. Construction of the storage facility is required for CAES. For an economical construction of a storage facility, it is necessary to construct a storage facility by excavating, from the ground surface, a cavity in the ground. There is no case in Japan where rock storage is adopted with several tens of atmospheric pressure which is necessary for CAES. If highly pressurized air can be stored by the water sealing method, it is a very economical method in the case with hard rocks. As the first stem to verify the effectivity of the water sealing system, a water sealing experiment is performed in a boring hole. It is confirmed that water sealing can be possible up to about 40 atmospheres, and it is found that the resistivity, open joint distribution and coefficient of permeability of rocks have correlation as an investigating method for potential cracks in rocks and that resistivity tomography is effective for the investigation of cracks in rocks. 9 ref., 23 figs., 6 tabs.

  4. Automated Control of a Solar Microgrid-Powered Air Compressor for Use in a Small-Scale Compressed Air Energy Storage System

    Science.gov (United States)

    2017-06-01

    26 xii Figure 21. Simplified Control Program Flowchart .....................................................30 Figure 22...for manual operation. Figure 21 shows the overall control program flowchart . The details of the PLC and the HMI programs are contained in Appendix C...Figure 21. Simplified Control Program Flowchart 31 3. Solar Power Production Status Since the air compressor cannot function without

  5. Energy storage, compression, and switching. Vol. 2

    International Nuclear Information System (INIS)

    Nardi, V.; Bostick, W.H.; Sahlin, H.

    1983-01-01

    This book is a compilation of papers presented at the Second International Conference on Energy Storage, Compression, and Switching, which was held in order to assemble active researchers with a major interest in plasma physics, electron beams, electric and magnetic energy storage systems, high voltage and high current switches, free-electron lasers, and pellet implosion plasma focus. Topics covered include: Slow systems: 50-60 Hz machinery, homopolar generators, slow capacitors, inductors, and solid state switches; Intermediate systems: fast capacitor banks; superconducting storage and switching; gas, vacuum, and dielectric switching; nonlinear (magnetic) switching; imploding liners capacitors; explosive generators; and fuses; and Fast systems: Marx, Blumlein, oil, water, and pressurized water dielectrics; switches; magnetic insulation; electron beams; and plasmas

  6. Numerical analysis of temperature and flow effects in a dry, two-dimensional, porous-media reservoir used for compressed air energy storage

    Energy Technology Data Exchange (ETDEWEB)

    Wiles, L.E.

    1979-10-01

    The purpose of the work is to define the hydrodynamic and thermodynamic response of a CAES dry porous media reservoir subjected to simulated air mass cycling. The knowledge gained will provide, or will assist in providing, design guidelines for the efficient and stable operation of the air storage reservoir. The analysis and results obtained by two-dimensional modeling of dry reservoirs are presented. While the fluid/thermal response of the underground system is dependent on many parameters, the two-dimensional model was applied only to those parameters that entered the analysis by virtue of inclusion of the vertical dimension. In particular, the parameters or responses that were quantified or characterized include wellbore heat transfer, heat losses to the vertical boundaries of the porous zone, gravitationally induced flows, producing length of the wellbore, and the effects of nonuniform permeability. The analysis of the wellbore heat transfer included consideration of insulation, preheating (bubble development with heated air), and air mass flow rate.

  7. Long-term storage of compressed radioactive krypton in cylinders

    International Nuclear Information System (INIS)

    Niephaus, D.; Nommensen, O.; Bruecher, H.

    1982-01-01

    The recommendations of the German Radiation Protection Commission necessitate the separation of the radioactive noble gas krypton-85 (Kr-85) produced in large LWR reprocessing plants from the dissolver off-gas. A possible method of removal is a long-term storage of the compressed noble gas above ground in cylinders. The aim of the present study is to develop such a storage concept and evaluate its feasibility under the aspects of safety and cost. After having been filled, the gas cylinders are placed separately into transport racks serving to protect the cylinders. Following this, the cylinders are transferred out of the filling station in a transport cask, conveyed to the storage building and stored there. The storage building protects the gas cylinders against external impacts. The storage cells constitute a second barrier against the release of Kr-85. The heat produced during decay of the Kr-85 in the gas cylinders is carried off by natural convection of the air circulating in the storage cells. To study possible corrosion attack on special steels due to rubidium, experiments were conducted at 200 0 C during test periods up to 3500h. In order to compare properties at elevated temperatures, corrosion experiments were conducted at 500 0 C, which is far above the maximum licensed storage temperature of 200 0 C. Experiments were conducted concerning the adsorption of krypton on various adsorbents, thus reducing the pressure inside the gas cylinder during storage. A cost estimate based on 1980 prices

  8. Compressed Air Production Using Vehicle Suspension

    Directory of Open Access Journals (Sweden)

    Ninad Arun Malpure

    2015-08-01

    Full Text Available Abstract Generally compressed air is produced using different types of air compressors which consumes lot of electric energy and is noisy. In this paper an innovative idea is put forth for production of compressed air using movement of vehicle suspension which normal is wasted. The conversion of the force energy into the compressed air is carried out by the mechanism which consists of the vehicle suspension system hydraulic cylinder Non-return valve air compressor and air receiver. We are collecting air in the cylinder and store this energy into the tank by simply driving the vehicle. This method is non-conventional as no fuel input is required and is least polluting.

  9. Survived ileocecal blowout from compressed air.

    Science.gov (United States)

    Weber, Marco; Kolbus, Frank; Dressler, Jan; Lessig, Rüdiger

    2011-03-01

    Industrial accidents with compressed air entering the gastro-intestinal tract often run fatally. The pressures usually over-exceed those used by medical applications such as colonoscopy and lead to vast injuries of the intestines with high mortality. The case described in this report is of a 26-year-old man who was harmed by compressed air that entered through the anus. He survived because of fast emergency operation. This case underlines necessity of explicit instruction considering hazards handling compressed air devices to maintain safety at work. Further, our observations support the hypothesis that the mucosa is the most elastic layer of the intestine wall.

  10. Thermal analysis of near-isothermal compressed gas energy storage system

    International Nuclear Information System (INIS)

    Odukomaiya, Adewale; Abu-Heiba, Ahmad; Gluesenkamp, Kyle R.; Abdelaziz, Omar; Jackson, Roderick K.; Daniel, Claus; Graham, Samuel; Momen, Ayyoub M.

    2016-01-01

    Highlights: • A novel, high-efficiency, scalable, near-isothermal, energy storage system is introduced. • A comprehensive analytical physics-based model for the system is presented. • Efficiency improvement is achieved via heat transfer enhancement and use of waste heat. • Energy storage roundtrip efficiency (RTE) of 82% and energy density of 3.59 MJ/m"3 is shown. - Abstract: Due to the increasing generation capacity of intermittent renewable electricity sources and an electrical grid ill-equipped to handle the mismatch between electricity generation and use, the need for advanced energy storage technologies will continue to grow. Currently, pumped-storage hydroelectricity and compressed air energy storage are used for grid-scale energy storage, and batteries are used at smaller scales. However, prospects for expansion of these technologies suffer from geographic limitations (pumped-storage hydroelectricity and compressed air energy storage), low roundtrip efficiency (compressed air energy storage), and high cost (batteries). Furthermore, pumped-storage hydroelectricity and compressed air energy storage are challenging to scale-down, while batteries are challenging to scale-up. In 2015, a novel compressed gas energy storage prototype system was developed at Oak Ridge National Laboratory. In this paper, a near-isothermal modification to the system is proposed. In common with compressed air energy storage, the novel storage technology described in this paper is based on air compression/expansion. However, several novel features lead to near-isothermal processes, higher efficiency, greater system scalability, and the ability to site a system anywhere. The enabling features are utilization of hydraulic machines for expansion/compression, above-ground pressure vessels as the storage medium, spray cooling/heating, and waste-heat utilization. The base configuration of the novel storage system was introduced in a previous paper. This paper describes the results

  11. Compressed Air/Vacuum Transportation Techniques

    Science.gov (United States)

    Guha, Shyamal

    2011-03-01

    General theory of compressed air/vacuum transportation will be presented. In this transportation, a vehicle (such as an automobile or a rail car) is powered either by compressed air or by air at near vacuum pressure. Four version of such transportation is feasible. In all versions, a ``c-shaped'' plastic or ceramic pipe lies buried a few inches under the ground surface. This pipe carries compressed air or air at near vacuum pressure. In type I transportation, a vehicle draws compressed air (or vacuum) from this buried pipe. Using turbine or reciprocating air cylinder, mechanical power is generated from compressed air (or from vacuum). This mechanical power transferred to the wheels of an automobile (or a rail car) drives the vehicle. In type II-IV transportation techniques, a horizontal force is generated inside the plastic (or ceramic) pipe. A set of vertical and horizontal steel bars is used to transmit this force to the automobile on the road (or to a rail car on rail track). The proposed transportation system has following merits: virtually accident free; highly energy efficient; pollution free and it will not contribute to carbon dioxide emission. Some developmental work on this transportation will be needed before it can be used by the traveling public. The entire transportation system could be computer controlled.

  12. 30 CFR 57.13020 - Use of compressed air.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Use of compressed air. 57.13020 Section 57... MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-UNDERGROUND METAL AND NONMETAL MINES Compressed Air and Boilers § 57.13020 Use of compressed air. At no time shall compressed air be directed toward a...

  13. 30 CFR 56.13020 - Use of compressed air.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Use of compressed air. 56.13020 Section 56... MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES Compressed Air and Boilers § 56.13020 Use of compressed air. At no time shall compressed air be directed toward a person...

  14. 30 CFR 77.412 - Compressed air systems.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Compressed air systems. 77.412 Section 77.412... for Mechanical Equipment § 77.412 Compressed air systems. (a) Compressors and compressed-air receivers... involving the pressure system of compressors, receivers, or compressed-air-powered equipment shall not be...

  15. Compressed air system audit in a chemical company

    Energy Technology Data Exchange (ETDEWEB)

    Radgen, P. [Fraunhofer ISI, Karlsruhe (Germany)

    2005-07-01

    This paper describes the results achieved during a compressed air system audit at a chemical company in Switzerland. The aim of the audit conducted in Muttenz at the site of Clariant Schweiz AG was to analyse the installed compressed air system and its operation in order to identify energy and cost saving potentials. Because there was measurement equipment already installed, it was not necessary to install a new meter. Instead the existing data had to be extracted from the controlled system and regrouped for the analysis. Aggregated data for 2003 and 2004 and a set of detailed data acquired in the course of one week were used for the analysis. The audit identified a number of measures to improve the compressed air system, but had to conclude that the saving potentials at this site are below average. The audit included the compressors, the air treatment and air distribution up to production or storage buildings. The saving potential identified was quantified as about 300 000 kWh/a, or 13.3% of the compressed air energy demand. The cost savings were calculated to be around 41 852 Swiss Franks. (orig.)

  16. Developing a dynamic control system for mine compressed air networks

    OpenAIRE

    Van Heerden, S.W.; Pelzer, R.; Marais, J.H.

    2014-01-01

    Mines in general, make use of compressed air systems for daily operational activities. Compressed air on mines is traditionally distributed via compressed air ring networks where multiple shafts are supplied with compressed air from an integral system. These compressed air networks make use of a number of compressors feeding the ring from various locations in the network. While these mines have sophisticated control systems to control these compressors, they are not dynamic systems. Compresso...

  17. Waste Feed Delivery Raw Water and Potable Water and Compressed Air Capacity Evaluation

    International Nuclear Information System (INIS)

    MAY, T.H.

    2000-01-01

    This study evaluated the ability of the Raw Water, Potable Water, and Compressed Air systems to support safe storage as well as the first phase of the Waste Feed Delivery. Several recommendations are made to improve the system

  18. 46 CFR 112.50-7 - Compressed air starting.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Compressed air starting. 112.50-7 Section 112.50-7... air starting. A compressed air starting system must meet the following: (a) The starting, charging... air compressors addressed in paragraph (c)(3)(i) of this section. (b) The compressed air starting...

  19. Roofbolters with compressed-air rotators

    Science.gov (United States)

    Lantsevich, MA; Repin Klishin, AA, VI; Kokoulin, DI

    2018-03-01

    The specifications of the most popular roofbolters of domestic and foreign manufacture currently in operation in coal mines are discussed. Compressed-air roofbolters SAP and SAP2 designed at the Institute of Mining are capable of drilling in hard rocks. The authors describe the compressed-air rotator of SAP2 roofbolter with alternate motion rotors. From the comparative analysis of characteristics of SAP and SAP 2 roofbolters, the combination of high-frequency axial and rotary impacts on a drilling tool in SAP2 ensure efficient drilling in rocks with the strength up to 160 MPa.

  20. AIRMaster: Compressed air system audit software

    International Nuclear Information System (INIS)

    Wheeler, G.M.; Bessey, E.G.; McGill, R.D.; Vischer, K.

    1997-01-01

    The project goal was to develop a software tool, AIRMaster, and a methodology for performing compressed air system audits. AIRMaster and supporting manuals are designed for general auditors or plant personnel to evaluate compressed air system operation with simple instrumentation during a short-term audit. AIRMaster provides a systematic approach to compressed air system audits, analyzing collected data, and reporting results. AIRMaster focuses on inexpensive Operation and Maintenance (O and M) measures, such as fixing air leaks and improving controls that can significantly improve performance and reliability of the compressed air system, without significant risk to production. An experienced auditor can perform an audit, analyze collected data, and produce results in 2--3 days. AIRMaster reduces the cost of an audit, thus freeing funds to implement recommendations. The AIRMaster package includes an Audit Manual, Software and User's manual, Analysis Methodology Manual, and a Case Studies summary report. It also includes a Self-Guided Tour booklet to help users quickly screen a plant for efficiency improvement potentials, and an Industrial Compressed Air Systems Energy Efficiency Guidebook. AIRMaster proved to be a fast and effective audit tool. In sever audits AIRMaster identified energy savings of 4,056,000 kWh, or 49.2% of annual compressor energy use, for a cost savings of $152,000. Total implementation costs were $94,700 for a project payback period of 0.6 years. Available airflow increased between 11% and 51% of plant compressor capacity, leading to potential capital benefits from 40% to 230% of first year energy savings

  1. Compressibility of air in fibrous materials

    DEFF Research Database (Denmark)

    Tarnow, Viggo

    1996-01-01

    The dynamic compressibility of air in fibrous materials has been computed for two assumed configurations of fibers which are close to the geometry of real fiber materials. Models with parallel cylinders placed in a regular square lattice and placed randomly are treated. For these models...... the compressibility is computed approximately from the diameter and mean distances between cylinders. This requires calculation of the air temperature, which is calculated for cylinders in a regular lattive by the Wigner-Seitz cell approximation. In the case of random placement, the calculation is done by a summation...... over thermal waves from all fibers, and by a self-consistent procedure. Figuren of the compressibility in the frequency range 10-100 000 Hz, are given for diameter of the cylinders of 6.8 µm, and mean distances between them from 50 to 110 µm, which corresponds to glass wool with a density of 40 to 16...

  2. Safety considerations for compressed hydrogen storage systems

    International Nuclear Information System (INIS)

    Gleason, D.

    2006-01-01

    An overview of the safety considerations for various hydrogen storage options, including stationary, vehicle storage, and mobile refueling technologies. Indications of some of the challenges facing the industry as the demand for hydrogen fuel storage systems increases. (author)

  3. Efficiency at Sorting Cards in Compressed Air

    Science.gov (United States)

    Poulton, E. C.; Catton, M. J.; Carpenter, A.

    1964-01-01

    At a site where compressed air was being used in the construction of a tunnel, 34 men sorted cards twice, once at normal atmospheric pressure and once at 3½, 2½, or 2 atmospheres absolute pressure. An additional six men sorted cards twice at normal atmospheric pressure. When the task was carried out for the first time, all the groups of men performing at raised pressure were found to yield a reliably greater proportion of very slow responses than the group of men performing at normal pressure. There was reliably more variability in timing at 3½ and 2½ atmospheres absolute than at normal pressure. At 3½ atmospheres absolute the average performance was also reliably slower. When the task was carried out for the second time, exposure to 3½ atmospheres absolute pressure had no reliable effect. Thus compressed air affected performance only while the task was being learnt; it had little effect after practice. No reliable differences were found related to age, to length of experience in compressed air, or to the duration of the exposure to compressed air, which was never less than 10 minutes at 3½ atmospheres absolute pressure. PMID:14180485

  4. 41 CFR 50-204.8 - Use of compressed air.

    Science.gov (United States)

    2010-07-01

    ... 41 Public Contracts and Property Management 1 2010-07-01 2010-07-01 true Use of compressed air. 50-204.8 Section 50-204.8 Public Contracts and Property Management Other Provisions Relating to Public... General Safety and Health Standards § 50-204.8 Use of compressed air. Compressed air shall not be used for...

  5. Compressed-air flow control system.

    Science.gov (United States)

    Bong, Ki Wan; Chapin, Stephen C; Pregibon, Daniel C; Baah, David; Floyd-Smith, Tamara M; Doyle, Patrick S

    2011-02-21

    We present the construction and operation of a compressed-air driven flow system that can be used for a variety of microfluidic applications that require rapid dynamic response and precise control of multiple inlet streams. With the use of inexpensive and readily available parts, we describe how to assemble this versatile control system and further explore its utility in continuous- and pulsed-flow microfluidic procedures for the synthesis and analysis of microparticles.

  6. Microfluidic pressure sensing using trapped air compression.

    Science.gov (United States)

    Srivastava, Nimisha; Burns, Mark A

    2007-05-01

    We have developed a microfluidic method for measuring the fluid pressure head experienced at any location inside a microchannel. The principal component is a microfabricated sealed chamber with a single inlet and no exit; the entrance to the single inlet is positioned at the location where pressure is to be measured. The pressure measurement is then based on monitoring the movement of a liquid-air interface as it compresses air trapped inside the microfabricated sealed chamber and calculating the pressure using the ideal gas law. The method has been used to measure the pressure of the air stream and continuous liquid flow inside microfluidic channels (d approximately 50 microm). Further, a pressure drop has also been measured using multiple microfabricated sealed chambers. For air pressure, a resolution of 700 Pa within a full-scale range of 700-100 kPa was obtained. For liquids, pressure drops as low as 70 Pa were obtained in an operating range from 70 Pa to 10 kPa. Since the method primarily uses a microfluidic sealed chamber, it does not require additional fabrication steps and may easily be incorporated in several lab-on-a-chip fluidic applications for laminar as well as turbulent flow conditions.

  7. Design of a Hydraulic Motor System Driven by Compressed Air

    OpenAIRE

    Shaw, Dein; Yu, Jyun-Jhe; Chieh, Cheng

    2013-01-01

    This paper presents the design of a highly efficient pneumatic motor system. The air engine is currently the most generally used device to convert potential energy of compressed air into mechanical energy. However, the efficiency of the air engines is too low to provide sufficient operating range for the vehicle. In this study, the energy contained in compressed air/pressurized hydraulic oil is transformed by a hydraulic motor to mechanical energy to enhance the efficiency of using air power....

  8. Self contained compressed air breathing apparatus to facilitate personnel decontamination

    Energy Technology Data Exchange (ETDEWEB)

    McDonald, C W [Radiological and Safety Division, Atomic Energy Establishment, Winfrith, Dorchester, Dorset (United Kingdom)

    1963-11-15

    This report describes the modification of a Self Contained Compressed Air Breathing Apparatus to provide extended respiratory protection to grossly contaminated personnel during a decontamination period which may exceed the duration of the Breathing Apparatus air supply. (author)

  9. Self contained compressed air breathing apparatus to facilitate personnel decontamination

    International Nuclear Information System (INIS)

    McDonald, C.W.

    1963-11-01

    This report describes the modification of a Self Contained Compressed Air Breathing Apparatus to provide extended respiratory protection to grossly contaminated personnel during a decontamination period which may exceed the duration of the Breathing Apparatus air supply. (author)

  10. Working characteristics of variable intake valve in compressed air engine.

    Science.gov (United States)

    Yu, Qihui; Shi, Yan; Cai, Maolin

    2014-01-01

    A new camless compressed air engine is proposed, which can make the compressed air energy reasonably distributed. Through analysis of the camless compressed air engine, a mathematical model of the working processes was set up. Using the software MATLAB/Simulink for simulation, the pressure, temperature, and air mass of the cylinder were obtained. In order to verify the accuracy of the mathematical model, the experiments were conducted. Moreover, performance analysis was introduced to design compressed air engine. Results show that, firstly, the simulation results have good consistency with the experimental results. Secondly, under different intake pressures, the highest output power is obtained when the crank speed reaches 500 rpm, which also provides the maximum output torque. Finally, higher energy utilization efficiency can be obtained at the lower speed, intake pressure, and valve duration angle. This research can refer to the design of the camless valve of compressed air engine.

  11. Working Characteristics of Variable Intake Valve in Compressed Air Engine

    Science.gov (United States)

    Yu, Qihui; Shi, Yan; Cai, Maolin

    2014-01-01

    A new camless compressed air engine is proposed, which can make the compressed air energy reasonably distributed. Through analysis of the camless compressed air engine, a mathematical model of the working processes was set up. Using the software MATLAB/Simulink for simulation, the pressure, temperature, and air mass of the cylinder were obtained. In order to verify the accuracy of the mathematical model, the experiments were conducted. Moreover, performance analysis was introduced to design compressed air engine. Results show that, firstly, the simulation results have good consistency with the experimental results. Secondly, under different intake pressures, the highest output power is obtained when the crank speed reaches 500 rpm, which also provides the maximum output torque. Finally, higher energy utilization efficiency can be obtained at the lower speed, intake pressure, and valve duration angle. This research can refer to the design of the camless valve of compressed air engine. PMID:25379536

  12. Working Characteristics of Variable Intake Valve in Compressed Air Engine

    Directory of Open Access Journals (Sweden)

    Qihui Yu

    2014-01-01

    Full Text Available A new camless compressed air engine is proposed, which can make the compressed air energy reasonably distributed. Through analysis of the camless compressed air engine, a mathematical model of the working processes was set up. Using the software MATLAB/Simulink for simulation, the pressure, temperature, and air mass of the cylinder were obtained. In order to verify the accuracy of the mathematical model, the experiments were conducted. Moreover, performance analysis was introduced to design compressed air engine. Results show that, firstly, the simulation results have good consistency with the experimental results. Secondly, under different intake pressures, the highest output power is obtained when the crank speed reaches 500 rpm, which also provides the maximum output torque. Finally, higher energy utilization efficiency can be obtained at the lower speed, intake pressure, and valve duration angle. This research can refer to the design of the camless valve of compressed air engine.

  13. Compressed Air Energy Storage in Offshore Grids

    DEFF Research Database (Denmark)

    Schröder, Sascha Thorsten; Crotogino, Fritz; Donadei, Sabine

    2011-01-01

    management framework is used as the basis for identifying key challenges and opportunities to enhance the integration of climate change adaptation in energy planning and decision-making. Given its importance for raising awareness and for stimulating action by planners and decision-makers, emphasis is placed......Energy systems are significantly vulnerable to current climate variability and extreme events. As climate change becomes more pronounced, the risks and vulnerabilities will be exacerbated. To date, energy sector adaptation issues have received very limited attention. In this paper, a climate risk...... barriers to integration of climate risks and adaptive responses in energy planning and decision making. Both detailed assessments of the costs and benefits of integrating adaptation measures and rougher ‘order of magnitude’ estimates would enhance awareness raising and momentum for action....

  14. 30 CFR 77.411 - Compressed air and boilers; general.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Compressed air and boilers; general. 77.411 Section 77.411 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR COAL MINE... COAL MINES Safeguards for Mechanical Equipment § 77.411 Compressed air and boilers; general. All...

  15. Compressing Control System Data for Efficient Storage and Retrieval

    International Nuclear Information System (INIS)

    Christopher Larrieu

    2003-01-01

    The controls group at the Thomas Jefferson National Accelerator Facility (Jefferson Lab), acquires multiple terabytes of EPICS control system data per year via CZAR, its new archiving system. By heuristically applying a combination of rudimentary compression techniques, in conjunction with several specialized data transformations and algorithms, the CZAR storage engine reduces the size of this data by approximately 88 percent, without any loss of information. While the compression process requires significant memory and processor time, the decompression routine suffers only slightly in this regard

  16. Electric power generating plant having direct-coupled steam and compressed-air cycles

    Science.gov (United States)

    Drost, M.K.

    1981-01-07

    An electric power generating plant is provided with a Compressed Air Energy Storage (CAES) system which is directly coupled to the steam cycle of the generating plant. The CAES system is charged by the steam boiler during off peak hours, and drives a separate generator during peak load hours. The steam boiler load is thereby levelized throughout an operating day.

  17. Electric power generating plant having direct coupled steam and compressed air cycles

    Science.gov (United States)

    Drost, Monte K.

    1982-01-01

    An electric power generating plant is provided with a Compressed Air Energy Storage (CAES) system which is directly coupled to the steam cycle of the generating plant. The CAES system is charged by the steam boiler during off peak hours, and drives a separate generator during peak load hours. The steam boiler load is thereby levelized throughout an operating day.

  18. Improving compressed air system performance: A sourcebook for industry

    OpenAIRE

    Mckane, Aimee T.

    2003-01-01

    Compressed air is used widely throughout industry and is often considered the "fourth utility" at many facilities. Almost every industrial plant, from a small machine shop to an immense pulp and paper mill, has some type of compressed air system. In many cases, the compressed air system is so vital that the facility cannot operate without it. Plant air compressor systems can vary in size from a small unit of 5 horsepower (hp) to huge systems with more than 50,000 hp. In many industrial facili...

  19. Lower operating cost due to compressed-air recirculation

    Energy Technology Data Exchange (ETDEWEB)

    Schauwecker, F

    1979-01-01

    Compressed air containing dirt and aggressive substances may cause damage in pipelines and pneumatic tools, equipment and systems. In consequence, operating costs can be greatly reduced by cleaning and recirculation of compressed air. Compressed-air driers are among the most common systems used for this purpose. Most of these driers are refrigeration driers; adsorption driers are less common. Refrigeration driers consist of a heat exchanger system, a separation system, and a power-controlled refrigerator. The water vapour concentration is proportional to the air temperature; for this reason, the pressure dew point should be as low as possible, i.e. about 1.5/sup 0/C.

  20. Energy storage

    International Nuclear Information System (INIS)

    Anon.

    1992-01-01

    This chapter discusses the role that energy storage may have on the energy future of the US. The topics discussed in the chapter include historical aspects of energy storage, thermal energy storage including sensible heat storage, latent heat storage, thermochemical heat storage, and seasonal heat storage, electricity storage including batteries, pumped hydroelectric storage, compressed air energy storage, and superconducting magnetic energy storage, and production and combustion of hydrogen as an energy storage option

  1. Mathematical modeling of compression processes in air-driven boosters

    International Nuclear Information System (INIS)

    Li Zeyu; Zhao Yuanyang; Li Liansheng; Shu Pengcheng

    2007-01-01

    The compressed air in normal pressure is used as the source of power of the air-driven booster. The continuous working of air-driven boosters relies on the difference of surface area between driven piston and driving piston, i.e., the different forces acting on the pistons. When the working surface area of the driving piston for providing power is greater than that of the driven piston for compressing gas, the gas in compression chamber will be compressed. On the basis of the first law of thermodynamics, the motion regulation of piston is analyzed and the mathematical model of compression processes is set up. Giving a calculating example, the vary trends of gas pressure and pistons' move in working process of booster have been gotten. The change of parameters at different working conditions is also calculated and compared. And the corresponding results can be referred in the design of air-driven boosters

  2. Accidental fatal lung injury by compressed air: a case report.

    Science.gov (United States)

    Rayamane, Anand Parashuram; Pradeepkumar, M V

    2015-03-01

    Compressed air is being used extensively as a source of energy at industries and in daily life. A variety of fatal injuries are caused by improper and ignorant use of compressed air equipments. Many types of injuries due to compressed air are reported in the literature such as colorectal injury, orbital injury, surgical emphysema, and so on. Most of these injuries are accidental in nature. It is documented that 40 pounds per square inch pressure causes fatal injuries to the ear, eyes, lungs, stomach, and intestine. Openings of body are vulnerable to injuries by compressed air. Death due to compressed air injuries is rarely reported. Many cases are treated successfully by conservative or surgical management. Extensive survey of literature revealed no reports of fatal injury to the upper respiratory tract and lungs caused by compressed air. Here, we are reporting a fatal event of accidental death after insertion of compressed air pipe into the mouth. The postmortem findings are corroborated with the history and discussed in detail.

  3. [Experimental study on spectra of compressed air microwave plasma].

    Science.gov (United States)

    Liu, Yong-Xi; Zhang, Gui-Xin; Wang, Qiang; Hou, Ling-Yun

    2013-03-01

    Using a microwave plasma generator, compressed air microwave plasma was excited under 1 - 5 atm pressures. Under different pressures and different incident microwave power, the emission spectra of compressed air microwave plasma were studied with a spectra measuring system. The results show that continuum is significant at atmospheric pressure and the characteristic will be weakened as the pressure increases. The band spectra intensity will be reduced with the falling of the incident microwave power and the band spectra were still significant. The experimental results are valuable to studying the characteristics of compressed air microwave plasma and the generating conditions of NO active groups.

  4. Energy Storage.

    Science.gov (United States)

    Eaton, William W.

    Described are technological considerations affecting storage of energy, particularly electrical energy. The background and present status of energy storage by batteries, water storage, compressed air storage, flywheels, magnetic storage, hydrogen storage, and thermal storage are discussed followed by a review of development trends. Included are…

  5. Lossless compression of waveform data for efficient storage and transmission

    International Nuclear Information System (INIS)

    Stearns, S.D.; Tan, Li Zhe; Magotra, Neeraj

    1993-01-01

    Compression of waveform data is significant in many engineering and research areas since it can be used to alleviate data storage and transmission bandwidth. For example, seismic data are widely recorded and transmitted so that analysis can be performed on large amounts of data for numerous applications such as petroleum exploration, determination of the earth's core structure, seismic event detection and discrimination of underground nuclear explosions, etc. This paper describes a technique for lossless wave form data compression. The technique consists of two stages. The first stage is a modified form of linear prediction with discrete coefficients and the second stage is bi-level sequence coding. The linear predictor generates an error or residue sequence in a way such that exact reconstruction of the original data sequence can be accomplished with a simple algorithm. The residue sequence is essentially white Gaussian with seismic or other similar waveform data. Bi-level sequence coding, in which two sample sizes are chosen and the residue sequence is encoded into subsequences that alternate from one level to the other, further compresses the residue sequence. The principal feature of the two-stage data compression algorithm is that it is lossless, that is, it allows exact, bit-for-bit recovery of the original data sequence. The performance of the lossless compression algorithm at each stage is analyzed. The advantages of using bi-level sequence coding in the second stage are its simplicity of implementation, its effectiveness on data with large amplitude variations, and its near-optimal performance in encoding Gaussian sequences. Applications of the two-stage technique to typical seismic data indicates that an average number of compressed bits per sample close to the lower bound is achievable in practical situations

  6. Economic study on compressed energy storage cogeneration system in urban areas

    International Nuclear Information System (INIS)

    Uchiyama, Youji

    1991-01-01

    Due to the concentration of functions into cities and the spread of room cooling facilities, the energy demand in cities increased rapidly especially in summer season. The improvement of load factor of electric power has become an important subject for electric power companies, and as the technology for positively improving it, there is electric power storage. As for compressed air energy storage (CAES) system, its introduction, has been investigated as the electric power storage technology for the future in electric power business, but since it is also gas turbine technology, it becomes a cogeneration system. If the waste heat of gas turbines and compressors can be utilized effectively, not only the load factor of electric power is improved, but also it contributes to the improvement of overall energy efficiency and the improvement of environmental problems. This research is to study on the feasibility of compressed air energy storage centering around its economical efficiency when it is installed in customer side as the cogeneration system in cities. The features of CAES, the tendency of the development in Japan and foreign countries, the introduction of CAES in new town districts and the economy are described. (K.I.)

  7. Investigation on wind energy-compressed air power system.

    Science.gov (United States)

    Jia, Guang-Zheng; Wang, Xuan-Yin; Wu, Gen-Mao

    2004-03-01

    Wind energy is a pollution free and renewable resource widely distributed over China. Aimed at protecting the environment and enlarging application of wind energy, a new approach to application of wind energy by using compressed air power to some extent instead of electricity put forward. This includes: explaining the working principles and characteristics of the wind energy-compressed air power system; discussing the compatibility of wind energy and compressor capacity; presenting the theoretical model and computational simulation of the system. The obtained compressor capacity vs wind power relationship in certain wind velocity range can be helpful in the designing of the wind power-compressed air system. Results of investigations on the application of high-pressure compressed air for pressure reduction led to conclusion that pressure reduction with expander is better than the throttle regulator in energy saving.

  8. Training Studies with Compressed Air Breathing Apparatus – Methodology, Exercises

    Directory of Open Access Journals (Sweden)

    Buks Roberts

    2015-11-01

    Full Text Available The current article describes topics ranging from the respiratory physiology and the structure of compressed air breathing apparatus to the performance of practical training exercises in an unbreathable environment (hereinafter referred to as UE.

  9. Acceptance Test Report for 241-U compressed air system

    International Nuclear Information System (INIS)

    Freeman, R.D.

    1994-01-01

    This Acceptance Test Report (ATR) documents the results of acceptance testing of a newly upgraded compressed air system at 241-U Farm. The system was installed and the test successfully performed under work package 2W-92-01027

  10. Compressed air piping, 241-SY-101 hydraulic pump retrieval trailer

    International Nuclear Information System (INIS)

    Wilson, T.R.

    1994-01-01

    The following Design Analysis was prepared by the Westinghouse Hanford Company to determine pressure losses in the compressed air piping installed on the hydraulic trailer for the 241-SY-101 pump retrieval mission

  11. Experimental Study of Air Vessel Behavior for Energy Storage or System Protection in Water Hammer Events

    Directory of Open Access Journals (Sweden)

    Mohsen Besharat

    2017-01-01

    Full Text Available An experimental assessment of an air pocket (AP, confined in a compressed air vessel (CAV, has been investigated under several different water hammer (WH events to better define the use of protection devices or compressed air energy storage (CAES systems. This research focuses on the size of an AP within an air vessel and tries to describe how it affects important parameters of the system, i.e., the pressure in the pipe, stored pressure, flow velocity, displaced volume of water and water level in the CAV. Results present a specific range of air pockets based on a dimensionless parameter extractable for other real systems.

  12. Compressed air massage hastens healing of the diabetic foot.

    Science.gov (United States)

    Mars, M; Desai, Y; Gregory, M A

    2008-02-01

    The management of diabetic foot ulcers remains a problem. A treatment modality that uses compressed air massage has been developed as a supplement to standard surgical and medical treatment. Compressed air massage is thought to improve local tissue oxygenation around ulcers. The aim of this study was to determine whether the addition of compressed air massage influences the rate of healing of diabetic ulcers. Sixty consecutive patients with diabetes, admitted to one hospital for urgent surgical management of diabetic foot ulcers, were randomized into two groups. Both groups received standard medical and surgical management of their diabetes and ulcer. In addition, one group received 15-20 min of compressed air massage, at 1 bar pressure, daily, for 5 days a week, to the foot and the tissue around the ulcer. Healing time was calculated as the time from admission to the time of re-epithelialization. Fifty-seven patients completed the trial; 28 received compressed air massage. There was no difference in the mean age, Wagner score, ulcer size, pulse status, or peripheral sensation in the two groups. The time to healing in the compressed air massage group was significantly reduced: 58.1 +/- 22.3 days (95% confidence interval: 49.5-66.6) versus 82.7 +/- 30.7 days (95% confidence interval: 70.0-94.3) (P = 0.001). No adverse effects in response to compressed air massage were noted. The addition of compressed air massage to standard medical and surgical management of diabetic ulcers appears to enhance ulcer healing. Further studies with this new treatment modality are warranted.

  13. 29 CFR 1926.803 - Compressed air.

    Science.gov (United States)

    2010-07-01

    ... ventilated, and there shall be no pockets of dead air. Outlets may be required at intermediate points along the main low-pressure air supply line to the heading to eliminate such pockets of dead air... of structures of wood over or near shafts. (6) Tunnels shall be provided with a 2-inch minimum...

  14. Choice of compressed air fed system of a uranium mine

    International Nuclear Information System (INIS)

    Li Congkui; Lei Zeyong

    2006-01-01

    The selection of compressed air fed system in a uranium mine is discussed. The research indicates that the movable air compressor is better than the fixed one in energy saving, once capital cost and operational cost when it is applied in an underground uranium mine. (authors)

  15. 30 CFR 56.13015 - Inspection of compressed-air receivers and other unfired pressure vessels.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Inspection of compressed-air receivers and... METAL AND NONMETAL MINES Compressed Air and Boilers § 56.13015 Inspection of compressed-air receivers and other unfired pressure vessels. (a) Compressed-air receivers and other unfired pressure vessels...

  16. 30 CFR 57.13015 - Inspection of compressed-air receivers and other unfired pressure vessels.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Inspection of compressed-air receivers and...-UNDERGROUND METAL AND NONMETAL MINES Compressed Air and Boilers § 57.13015 Inspection of compressed-air receivers and other unfired pressure vessels. (a) Compressed-air receivers and other unfired pressure...

  17. Design of a Hydraulic Motor System Driven by Compressed Air

    Directory of Open Access Journals (Sweden)

    Jyun-Jhe Yu

    2013-06-01

    Full Text Available This paper presents the design of a highly efficient pneumatic motor system. The air engine is currently the most generally used device to convert potential energy of compressed air into mechanical energy. However, the efficiency of the air engines is too low to provide sufficient operating range for the vehicle. In this study, the energy contained in compressed air/pressurized hydraulic oil is transformed by a hydraulic motor to mechanical energy to enhance the efficiency of using air power. To evaluate the theoretical efficiency, the principle of balance of energy is applied. The theoretical efficiency of converting air into hydraulic energy is found to be a function of pressure; thus, the maximum converting efficiency can be determined. To confirm the theoretical evaluation, a prototype of the pneumatic hydraulic system is built. The experiment verifies that the theoretical evaluation of the system efficiency is reasonable, and that the layout of the system is determined by the results of theoretical evaluation.

  18. Health and efficiency in trimix versus air breathing in compressed air workers

    NARCIS (Netherlands)

    van Rees Vellinga, T. P.; Verhoeven, A. C.; van Dijk, F. J. H.; Sterk, W.

    2006-01-01

    The Western Scheldt Tunneling Project in the Netherlands provided a unique opportunity to evaluate the effects of trimix usage on the health of compressed air workers and the efficiency of the project. Data analysis addressed 318 exposures to compressed air at 3.9-4.4 bar gauge and 52 exposures to

  19. Effect of cement/wood ratios and wood storage conditions on hydration temperature, hydration time, and compressive strength of wood-cement mixtures

    Science.gov (United States)

    Andy W.C. Lee; Zhongli Hong; Douglas R. Phillips; Chung-Yun Hse

    1987-01-01

    This study investigated the effect of cement/wood ratios and wood storage conditions on hydration temperature, hydration time, and compressive strength of wood-cement mixtures made from six wood species: southern pine, white oak, southern red oak, yellow-poplar, sweetgum, and hickory. Cement/wood ratios varied from 13/1 to 4/1. Wood storage conditions consisted of air-...

  20. Compressed air production with waste heat utilization in industry

    Science.gov (United States)

    Nolting, E.

    1984-06-01

    The centralized power-heat coupling (PHC) technique using block heating power stations, is presented. Compressed air production in PHC technique with internal combustion engine drive achieves a high degree of primary energy utilization. Cost savings of 50% are reached compared to conventional production. The simultaneous utilization of compressed air and heat is especially interesting. A speed regulated drive via an internal combustion motor gives a further saving of 10% to 20% compared to intermittent operation. The high fuel utilization efficiency ( 80%) leads to a pay off after two years for operation times of 3000 hr.

  1. The Design of Compressed air system in the Conventional Facility of Proton Accelerator Research Center

    International Nuclear Information System (INIS)

    Jeon, G. P.; Kim, J. Y.; Cho, S. W.; Min, Y. S.; Mun, K. J.; Cho, J. S.; Nam, J. M.; Park, S. S.; Jo, J. H.

    2012-01-01

    The Compressed Air System (CA) supplies compressed air for all air operated devices and instruments, pneumatic equipment and other miscellaneous air user points in the Conventional Facilities of Proton Engineering Frontier Project. CA System consist of the Instrument Air System and the Service air System. The Instrument Air System supplies oil-free, dried, filtered, and compressed instrument air for the air operated control devices and instruments in the Accelerator and Beam Application Building, Ion Beam Application Building, Utility Building and etc.. The Service air System supplies compressed air for pneumatic equipment and other services

  2. Use of phase change materials during compressed air expansion for isothermal CAES plants

    Science.gov (United States)

    Castellani, B.; Presciutti, A.; Morini, E.; Filipponi, M.; Nicolini, A.; Rossi, F.

    2017-11-01

    Compressed air energy storage (CAES) plants are designed to store compressed air into a vessel or in an underground cavern and to expand it in an expansion turbine when energy demand is high. An innovative CAES configuration recently proposed is the isothermal process. Several methods to implement isothermal CAES configuration are under investigation. In this framework, the present paper deals with the experimental testing of phase change materials (PCM) during compressed air expansion phase. The experimental investigation was carried out by means of an apparatus constituted by a compression section, a steel pressure vessel, to which an expansion valve is connected. The initial internal absolute pressure was equal to 5 bar to avoid moisture condensation and the experimental tests were carried out with two paraffin-based PCM amounts (0.05 kg and 0.1 kg). Results show that the temperature change during air expansion decreases with increasing the PCM amount inside the vessel. With the use of PCM during expansions an increase of the expansion work occurs. The increase is included in the range from 9.3% to 18.2%. In every test there is an approach to the isothermal values, which represent the maximum theoretical value of the obtainable expansion work.

  3. Experience with compressed air system of Dhruva and Cirus

    International Nuclear Information System (INIS)

    Shelar, V.G.; Patil, U.D.; Singh, V.K.; Zope, A.K.; Kharpate, A.V.

    2006-01-01

    Dhruva and Cirus reactors have independent compressed air plants with provision for sharing. Dhruva has the reciprocating oil free air compressors where as Cirus has oil lubricated compressors. Over the years, several improvements have been done in the equipments to combat various problems, among these noise mitigation in Dhruva and measures to extend life of compressors in Cirus and also incidence of discharge header catching fire are interesting. This paper details these experiences. (author)

  4. Air Compressibility Effect on Bouwer and Rice Seepage Meter.

    Science.gov (United States)

    Peng, Xin; Zhan, Hongbin

    2017-11-01

    Measuring a disconnected streambed seepage flux using a seepage meter can give important streambed information and help understanding groundwater-surface water interaction. In this study, we provide a correction for calculating the seepage flux rate with the consideration of air compressibility inside the manometer of the Bouwer and Rice seepage meter. We notice that the effect of air compressibility in the manometer is considerably larger when more air is included in the manometer. We find that the relative error from neglecting air compressibility can be constrained within 5% if the manometer of the Bouwer and Rice seepage meter is shorter than 0.8 m and the experiment is done in a suction mode in which air is pumped out from the manometer before the start of measurement. For manometers longer than 0.8 m, the relative error will be larger than 5%. It may be over 10% if the manometer height is longer than 1.5 m and the experiment is done in a no-suction mode, in which air is not pumped out from the manometer before the start of measurement. © 2017, National Ground Water Association.

  5. EFFECTS OF COMPRESSED AIR FOAM APPLICATION ON HEAT

    Directory of Open Access Journals (Sweden)

    Adam THOMITZEK

    2015-12-01

    Full Text Available This article evaluates the knowledge obtained in firefighting tests using compressed air foam system (CAFS within a confined space. Six experiments were conducted for verification during the cooling of rooms and the self-extinguishing effect. The simulation was for a fully developed fire within a room. The fuel was chosen to simulate ordinary combustible materials utilized in residential areas. Mantel thermocouples were placed in the rooms to record the temperature changes. Compressed air foam was first applied with a standard fire hose nozzle to the ceiling and then to the epicenter of fire. Fire extinguishing was initiated after reaching the desired temperature in the room. The temperature for the start of fire extinguishing matched the third phase of development of a fire. Fire extinguishing was terminated after no obvious signs of fire were shown in epicenter of fire. The outputs of the experiments were evaluated on the basis of the amount of time passed for the temperature to drop below the suggested limit. Individual experiments were also conducted with various different admixing foaming agents over different locations. In the experiments, it has been verified that the application of compressed air foam has a positive effect on room cooling. Use of a compressed air foaming agent does not allow for the development of steam that can scald firefighters and reduce visibility. Furthermore, the extinguishing agent used is more efficient utilizing less water flow out of the fire area.

  6. Improving Compressed Air System Performance: A Sourcebook for Industry

    Energy Technology Data Exchange (ETDEWEB)

    2003-11-01

    NREL will produce this sourcebook for DOE's Industrial Technologies Office as part of a series of documents on industrial energy equipment. The sourcebook is a reference for industrial compressed air system users, outlining opportunities to improve system efficiency.

  7. The function profile of compressed-air and ultrasonic nebulizers.

    Science.gov (United States)

    Wu, Hsin-Lin; Lin, Yung-Zen; Wu, Wei-Fong; Huang, Fu-Yuan

    2003-01-01

    In order to study the detailed function of two kinds of nebulizers commonly used in clinical asthma treatment, compressed-air and ultrasonic, this study was conducted. At the beginning, various flow rates were adjusted, paired with different volumes of solutions in the container. The changes of temperature, pH, and osmolality during the course of nebulization were examined. Normal saline, terbutaline, and fenoterol solutions were used as the nebulized solutions. The study was performed in an environment in ambient temperature around 20 degrees C and relative humidity around 70%. The results showed a minimal 6 L/min flow rate was required to nebulize the solution when using the compressed-air nebulizer. The dead volume was about 0.8 ml for compressed-air and 8.5 ml for the ultrasonic nebulizer. When using the compressed-air nebulizer, the temperature, both in the solution and at the mouthpiece site, dropped gradually. On the contrary, the temperatures at both sites increased a little bit when using the ultrasonic nebulizer. The pH values of pure terbutaline and fenoterol nebulized solutions were acidic (3.58 and 3.00 respectively). The osmolality of terbutaline and fenoterol nebulized solutions were isotonic. The osmolality increased gradually during the course of nebulization, to a greater extent in the compressed-air nebulizer. In conclusion, both types of nebulizers have their special features. The ultrasonic nebulizer displays less extent in change of temperature and osmolality during nebulization and is expected to be a better device in treating asthmatic patients in terms of lesser effect on cooling and changing the osmolality of airway mucosa.

  8. Free-beam soliton self-compression in air

    Science.gov (United States)

    Voronin, A. A.; Mitrofanov, A. V.; Sidorov-Biryukov, D. A.; Fedotov, A. B.; Pugžlys, A.; Panchenko, V. Ya; Shumakova, V.; Ališauskas, S.; Baltuška, A.; Zheltikov, A. M.

    2018-02-01

    We identify a physical scenario whereby soliton transients generated in freely propagating laser beams within the regions of anomalous dispersion in air can be compressed as a part of their free-beam spatiotemporal evolution to yield few-cycle mid- and long-wavelength-infrared field waveforms, whose peak power is substantially higher than the peak power of the input pulses. We show that this free-beam soliton self-compression scenario does not require ionization or laser-induced filamentation, enabling high-throughput self-compression of mid- and long-wavelength-infrared laser pulses within a broad range of peak powers from tens of gigawatts up to the terawatt level. We also demonstrate that this method of pulse compression can be extended to long-range propagation, providing self-compression of high-peak-power laser pulses in atmospheric air within propagation ranges as long as hundreds of meters, suggesting new ways towards longer-range standoff detection and remote sensing.

  9. Compressed air injection technique to standardize block injection pressures.

    Science.gov (United States)

    Tsui, Ban C H; Li, Lisa X Y; Pillay, Jennifer J

    2006-11-01

    Presently, no standardized technique exists to monitor injection pressures during peripheral nerve blocks. Our objective was to determine if a compressed air injection technique, using an in vitro model based on Boyle's law and typical regional anesthesia equipment, could consistently maintain injection pressures below a 1293 mmHg level associated with clinically significant nerve injury. Injection pressures for 20 and 30 mL syringes with various needle sizes (18G, 20G, 21G, 22G, and 24G) were measured in a closed system. A set volume of air was aspirated into a saline-filled syringe and then compressed and maintained at various percentages while pressure was measured. The needle was inserted into the injection port of a pressure sensor, which had attached extension tubing with an injection plug clamped "off". Using linear regression with all data points, the pressure value and 99% confidence interval (CI) at 50% air compression was estimated. The linearity of Boyle's law was demonstrated with a high correlation, r = 0.99, and a slope of 0.984 (99% CI: 0.967-1.001). The net pressure generated at 50% compression was estimated as 744.8 mmHg, with the 99% CI between 729.6 and 760.0 mmHg. The various syringe/needle combinations had similar results. By creating and maintaining syringe air compression at 50% or less, injection pressures will be substantially below the 1293 mmHg threshold considered to be an associated risk factor for clinically significant nerve injury. This technique may allow simple, real-time and objective monitoring during local anesthetic injections while inherently reducing injection speed.

  10. Colorectal injury by compressed air: the rule of conservative therapy

    Directory of Open Access Journals (Sweden)

    Labib Al-Ozaibi

    2017-01-01

    Full Text Available We are reporting a case of colorectal injury caused by a jet of compressed air directed from a distance towards the anus. The patient mentioned that it happened accidentally while his colleague was cleaning his clothes using compressed air. The patient presented with acute abdominal pain and distension. A contrast CT study did not show any free air or leakage. The patient was treated conservatively, progressed well and was discharged from the hospital on the fourth day. Resumo: Descrevemos um caso de lesão colorretal causada por um jato de ar comprimido direcionado para o ânus, a certa distância. O paciente mencionou que o ocorrido foi acidental, enquanto um colega estava limpando suas roupas com ar comprimido. O paciente se apresentou com dores abdominais agudas e distensão. Um estudo de TC contrastado não demonstrou ar livre, nem vazamento. O paciente foi tratado conservadoramente, teve boa evolução e recebeu alta hospitalar no quarto dia. Keywords: Compressed air colon injury, Colon barotrauma, Pneumatic bowel injury, Palavras-chave: Lesão de colon por ar comprimido, Barotrauma de colon, Lesão intestinal pneumática

  11. Rupture of sigmoid colon caused by compressed air.

    Science.gov (United States)

    Yin, Wan-Bin; Hu, Ji-Lin; Gao, Yuan; Zhang, Xian-Xiang; Zhang, Mao-Shen; Liu, Guang-Wei; Zheng, Xue-Feng; Lu, Yun

    2016-03-14

    Compressed air has been generally used since the beginning of the 20(th) century for various applications. However, rupture of the colon caused by compressed air is uncommon. We report a case of pneumatic rupture of the sigmoid colon. The patient was admitted to the emergency room complaining of abdominal pain and distention. His colleague triggered a compressed air nozzle against his anus as a practical joke 2 h previously. On arrival, his pulse rate was 126 beats/min, respiratory rate was 42 breaths/min and blood pressure was 86/54 mmHg. Physical examination revealed peritoneal irritation and the abdomen was markedly distended. Computed tomography of the abdomen showed a large volume of air in the abdominal cavity. Peritoneocentesis was performed to relieve the tension pneumoperitoneum. Emergency laparotomy was done after controlling shock. Laparotomy revealed a 2-cm perforation in the sigmoid colon. The perforation was sutured and temporary ileostomy was performed as well as thorough drainage and irrigation of the abdominopelvic cavity. Reversal of ileostomy was performed successfully after 3 mo. Follow-up was uneventful. We also present a brief literature review.

  12. Design Fabrication And Partial-Analysis Of A 2-Wheeler Prototype That Runs On Compressed Air

    Directory of Open Access Journals (Sweden)

    P Vinay

    2015-08-01

    Full Text Available Abstract The primary objective of the project is to create a prototype of a purely air powered motorcycle by retrofitting its internal combustion engine to run on compressed air. Firstly the conventional spark plug was replaced with a solenoid valve. The solenoid valve was initially actuated using a reed switch and magnet duo but then later replaced with an optical crank position sensor circuit due to reasons that include lack of control over the amount of air injected during each stroke and also for more precise control over the opening and closing of the valve. The torque brake power indicated power air consumption rate of the engine under load are calculated. Separate mounts for the modified engine and the cylindrical storage unit are designed and analysed using Catia v4. Also possible ways of future scope of the prototype are mentioned.

  13. Dynamic compressibility of air in porous structures at audible frequencies

    DEFF Research Database (Denmark)

    Lafarge, Denis; Lemarinier, Pavel; Allard, Jean F.

    1997-01-01

    Measurements of dynamic compressibility of air-filled porous sound-absorbing materials are compared with predictions involving two parametere, the static thermal permeability k'_0 and the thermal characteristic dimension GAMMA'. Emphasis on the notion of dynamic and static thermal permeability...... of the viscous forces. Using both parameters, a simple model is constructed for the dynamic thermal permeability k', which is completely analogous to the Johnson et al. [J. Fluid Mech. vol. 176, 379 (1987)] model of dynamic viscous permeability k. The resultant modeling of dynamic compressibility provides...... predictions which are closer to the experimental results than the previously used simpler model where the compressibility is the same as in identical circular cross-sectional shaped pores, or distributions of slits, related to a given GAMMA'....

  14. Compressed-air power tools in orthopaedic surgery: exhaust air is a potential source of contamination.

    Science.gov (United States)

    Sagi, H C; DiPasquale, Thomas; Sanders, Roy; Herscovici, Dolfi

    2002-01-01

    To determine if the exhaust from surgical compressed-air power tools contains bacteria and if the exhaust leads to contamination of sterile surfaces. Bacteriologic study of orthopaedic power tools. Level I trauma center operative theater. None. Part I. Exhaust from two sterile compact air drills was sampled directly at the exhaust port. Part II. Exhaust from the drills was directed at sterile agar plates from varying distances. The agar plates represented sterile surfaces within the operative field. Part III. Control cultures. A battery-powered drill was operated over open agar plates in similar fashion as the compressed-air drills. Agar plates left open in the operative theater served as controls to rule out atmospheric contamination. Random cultures were taken from agar plates, gloves, drills, and hoses. Incidence of positive cultures. In Part I, all filters from both compressed-air drill exhausts were culture negative ( = 0.008). In Part II, the incidence of positive cultures for air drills number one and number two was 73% and 82%, respectively. The most commonly encountered organisms were, coagulase-negative Staphylococcus, and Micrococcus species. All control cultures from agar plates, battery-powered drill, gloves, and hoses were negative ( compressed-air power tools in orthopaedic surgery may contribute to the dissemination of bacteria onto the surgical field. We do not recommend the use of compressed-air power tools that do not have a contained exhaust.

  15. Thermo-dynamic analysis and simulation of a combined air and hydro energy storage (CAHES) system

    International Nuclear Information System (INIS)

    Bi, Xianyun; Liu, Pei; Li, Zheng

    2016-01-01

    Large-scale energy storage is essential for the stability of a grid, especially for those with large proportion of intermittent renewable energy sources. The efficiency of a conventional compressed air energy storage (CAES) technology is limited by compression heat loss and changing working conditions. In this manuscript, a combined air and hydro energy storage (CAHES) system is proposed, which realizes a higher exergy efficiency compared with conventional CAES systems by reducing compression heat losses and addressing issues of changing working conditions through thermal compensation from solar radiation. The configuration and two operating modes of the proposed CAHES system are firstly introduced, followed by theoretical analysis and numerical simulation under different operating modes to analyze system performances. Impacts of external and internal factors on the system performances are analyzed. The practical feasibility of the system is also investigated. Results show that the exergy efficiency of the system reaches approximately 50%, whilst the charging electricity ratio reaches over 80%. - Highlights: • A combined air and hydro energy storage system is proposed. • High exergy efficiency is achieved and consumption of fossil fuel is eliminated. • The system performance is affected by compression ratio and solar radiation.

  16. On the estimation method of compressed air consumption during pneumatic caisson sinking

    OpenAIRE

    平川, 修治; ヒラカワ, シュウジ; Shuji, HIRAKAWA

    1990-01-01

    There are several methods in estimation of compressed air consumption during pneumatic caisson sinking. It is re uired in the estimation of compressed air consumption by the methods under the same conditions. In this paper, it is proposed the methods which is able to estimate accurately the compressed air consumption during pnbumatic caissons sinking at this moment.

  17. Compression and decompression of digital seismic waveform data for storage and communication

    International Nuclear Information System (INIS)

    Bhadauria, Y.S.; Kumar, Vijai

    1991-01-01

    Two different classes of data compression schemes, namely physical data compression schemes and logical data compression schemes are examined for their use in storage and communication of digital seismic waveform data. In physical data compression schemes, the physical size of the waveform is reduced. One, therefore, gets only a broad picture of the original waveform, when the data are retrieved and the waveform is reconstituted. Coerrelation between original and decompressed waveform varies inversely with the data compresion ratio. In the logical data compression schemes, the data are stored in a logically encoded form. Storage of unnecessary characters like blank space is avoided. On decompression original data are retrieved and compression error is nil. Three algorithms of logical data compression schemes have been developed and studied. These are : 1) optimum formatting schemes, 2) differential bit reduction scheme, and 3) six bit compression scheme. Results of the above three algorithms of logical compression class are compared with those of physical compression schemes reported in literature. It is found that for all types of data, six bit compression scheme gives the highest value of data compression ratio. (author). 6 refs., 8 figs., 1 appendix, 2 tabs

  18. CLASSIFICATION OF THE MGR SITE COMPRESSED AIR SYSTEM

    International Nuclear Information System (INIS)

    J.A. Ziegler

    1999-01-01

    The purpose of this analysis is to document the Quality Assurance (QA) classification of the Monitored Geologic Repository (MGR) site compressed air system structures, systems and components (SSCs) performed by the MGR Safety Assurance Department. This analysis also provides the basis for revision of YMP/90-55Q, Q-List (YMP 1998). The Q-List identifies those MGR SSCs subject to the requirements of DOE/RW-0333P, ''Quality Assurance Requirements and Description'' (QARD) (DOE 1998)

  19. Micro-jet Cooling by Compressed Air after MAG Welding

    Directory of Open Access Journals (Sweden)

    Węgrzyn T.

    2016-06-01

    Full Text Available The material selected for this investigation was low alloy steel weld metal deposit (WMD after MAG welding with micro-jet cooling. The present investigation was aimed as the following tasks: analyze impact toughness of WMD in terms of micro-jet cooling parameters. Weld metal deposit (WMD was first time carried out for MAG welding with micro-jet cooling of compressed air and gas mixture of argon and air. Until that moment only argon, helium and nitrogen and its gas mixture were tested for micro-jet cooling.

  20. Micro-jet Cooling by Compressed Air after MAG Welding

    OpenAIRE

    Węgrzyn T.; Piwnik J.; Tarasiuk W.; Stanik Z.; Gabrylewski M.

    2016-01-01

    The material selected for this investigation was low alloy steel weld metal deposit (WMD) after MAG welding with micro-jet cooling. The present investigation was aimed as the following tasks: analyze impact toughness of WMD in terms of micro-jet cooling parameters. Weld metal deposit (WMD) was first time carried out for MAG welding with micro-jet cooling of compressed air and gas mixture of argon and air. Until that moment only argon, helium and nitrogen and its gas mixture were tested for mi...

  1. Orbital compressed air and petroleum injury mimicking necrotizing fasciitis.

    Science.gov (United States)

    Mellington, Faye E; Bacon, Annette S; Abu-Bakra, Mohammed A J; Martinez-Devesa, Pablo; Norris, Jonathan H

    2014-09-01

    Orbital injury secondary to petroleum-based products is rare. We report the first case, to our knowledge, of a combined compressed air and chemical orbital injury, which mimicked necrotizing fasciitis. A 58-year-old man was repairing his motorcycle engine when a piston inadvertently fired, discharging compressed air and petroleum-based carburetor cleaner into his left eye. He developed surgical emphysema, skin necrosis, and a chemical cellulitis, causing an orbital compartment syndrome. He was treated initially with antibiotics and subsequently with intravenous steroid and orbital decompression surgery. There was almost complete recovery by 4 weeks postsurgery. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: Petroleum-based products can cause severe skin irritation and necrosis. Compressed air injury can cause surgical emphysema. When these two mechanisms of injury are combined, the resulting orbitopathy and skin necrosis can mimic necrotizing fasciitis and cause diagnostic confusion. A favorable outcome is achievable with aggressive timely management. Copyright © 2014 Elsevier Inc. All rights reserved.

  2. Compressed air-assisted solvent extraction (CASX) for metal removal.

    Science.gov (United States)

    Li, Chi-Wang; Chen, Yi-Ming; Hsiao, Shin-Tien

    2008-03-01

    A novel process, compressed air-assisted solvent extraction (CASX), was developed to generate micro-sized solvent-coated air bubbles (MSAB) for metal extraction. Through pressurization of solvent with compressed air followed by releasing air-oversaturated solvent into metal-containing wastewater, MSAB were generated instantaneously. The enormous surface area of MSAB makes extraction process extremely fast and achieves very high aqueous/solvent weight ratio (A/S ratio). CASX process completely removed Cr(VI) from acidic electroplating wastewater under A/S ratio of 115 and extraction time of less than 10s. When synthetic wastewater containing Cd(II) of 50mgl(-1) was treated, A/S ratios of higher than 714 and 1190 could be achieved using solvent with extractant/diluent weight ratio of 1:1 and 5:1, respectively. Also, MSAB have very different physical properties, such as size and density, compared to the emulsified solvent droplets, making separation and recovery of solvent from treated effluent very easy.

  3. Improved fireman's compressed air breathing system pressure vessel development program

    Science.gov (United States)

    King, H. A.; Morris, E. E.

    1973-01-01

    Prototype high pressure glass filament-wound, aluminum-lined pressurant vessels suitable for use in a fireman's compressed air breathing system were designed, fabricated, and acceptance tested in order to demonstrate the feasibility of producing such high performance, lightweight units. The 4000 psi tanks have a 60 standard cubic foot (SCF) air capacity, and have a 6.5 inch diamter, 19 inch length, 415 inch volume, weigh 13 pounds when empty, and contain 33 percent more air than the current 45 SCF (2250 psi) steel units. The current steel 60 SCF (3000 psi) tanks weigh approximately twice as much as the prototype when empty, and are 2 inches, or 10 percent shorter. The prototype units also have non-rusting aluminum interiors, which removes the hazard of corrosion, the need for internal coatings, and the possibility of rust particles clogging the breathing system.

  4. Geophysical assessments of renewable gas energy compressed in geologic pore storage reservoirs.

    Science.gov (United States)

    Al Hagrey, Said Attia; Köhn, Daniel; Rabbel, Wolfgang

    2014-01-01

    Renewable energy resources can indisputably minimize the threat of global warming and climate change. However, they are intermittent and need buffer storage to bridge the time-gap between production (off peak) and demand peaks. Based on geologic and geochemical reasons, the North German Basin has a very large capacity for compressed air/gas energy storage CAES in porous saltwater aquifers and salt cavities. Replacing pore reservoir brine with CAES causes changes in physical properties (elastic moduli, density and electrical properties) and justify applications of integrative geophysical methods for monitoring this energy storage. Here we apply techniques of the elastic full waveform inversion FWI, electric resistivity tomography ERT and gravity to map and quantify a gradually saturated gas plume injected in a thin deep saline aquifer within the North German Basin. For this subsurface model scenario we generated different synthetic data sets without and with adding random noise in order to robust the applied techniques for the real field applications. Datasets are inverted by posing different constraints on the initial model. Results reveal principally the capability of the applied integrative geophysical approach to resolve the CAES targets (plume, host reservoir, and cap rock). Constrained inversion models of elastic FWI and ERT are even able to recover well the gradual gas desaturation with depth. The spatial parameters accurately recovered from each technique are applied in the adequate petrophysical equations to yield precise quantifications of gas saturations. Resulting models of gas saturations independently determined from elastic FWI and ERT techniques are in accordance with each other and with the input (true) saturation model. Moreover, the gravity technique show high sensitivity to the mass deficit resulting from the gas storage and can resolve saturations and temporal saturation changes down to ±3% after reducing any shallow fluctuation such as that of

  5. Preliminary Investigation of an Underwater Ramjet Powered by Compressed Air

    Science.gov (United States)

    Mottard, Elmo J.; Shoemaker, Charles J.

    1961-01-01

    Part I contains the results of a preliminary experimental investigation of a particular design of an underwater ramjet or hydroduct powered by compressed air. The hydroduct is a propulsion device in which the energy of an expanding gas imparts additional momentum to a stream of water through mixing. The hydroduct model had a fineness ratio of 5.9, a maximum diameter of 3.2 inches, and a ratio of inlet area to frontal area of 0.32. The model was towed at a depth of 1 inch at forward speeds between 20 and 60 feet per second for airflow rates from 0.1 to 0.3 pound per second. Longitudinal force and pressures at the inlet and in the mixing chamber were determined. The hydroduct produced a positive thrust-minus-drag force at every test speed. The force and pressure coefficients were functions primarily of the ratio of weight airflow to free-stream velocity. The maximum propulsive efficiency based on the net internal thrust and an isothermal expansion of the air was approximately 53 percent at a thrust coefficient of 0.10. The performance of the test model may have been influenced by choking of the exit flow. Part II is a theoretical development of an underwater ramjet using air as "fuel." The basic assumption of the theoretical analysis is that a mixture of water and air can be treated as a compressible gas. More information on the properties of air-water mixtures is required to confirm this assumption or to suggest another approach. A method is suggested from which a more complete theoretical development, with the effects of choking included, may be obtained. An exploratory computation, in which this suggested method was used, indicated that the effect of choked flow on the thrust coefficient was minor.

  6. 76 FR 4338 - Research and Development Strategies for Compressed & Cryo-Compressed Hydrogen Storage Workshops

    Science.gov (United States)

    2011-01-25

    ... Hydrogen Storage Workshops AGENCY: Fuel Cell Technologies Program, Office of Energy Efficiency and... the National Renewable Energy Laboratory, in conjunction with the Hydrogen Storage team of the EERE... hydrogen storage in the Washington, DC metro area. DATES: The workshops will be held on Monday, February 14...

  7. Methods for Sampling and Measurement of Compressed Air Contaminants

    International Nuclear Information System (INIS)

    Stroem, L.

    1976-10-01

    In order to improve the technique for measuring oil and water entrained in a compressed air stream, a laboratory study has been made of some methods for sampling and measurement. For this purpose water or oil as artificial contaminants were injected in thin streams into a test loop, carrying dry compressed air. Sampling was performed in a vertical run, down-stream of the injection point. Wall attached liquid, coarse droplet flow, and fine droplet flow were sampled separately. The results were compared with two-phase flow theory and direct observation of liquid behaviour. In a study of sample transport through narrow tubes, it was observed that, below a certain liquid loading, the sample did not move, the liquid remaining stationary on the tubing wall. The basic analysis of the collected samples was made by gravimetric methods. Adsorption tubes were used with success to measure water vapour. A humidity meter with a sensor of the aluminium oxide type was found to be unreliable. Oil could be measured selectively by a flame ionization detector, the sample being pretreated in an evaporation- condensation unit

  8. Methods for Sampling and Measurement of Compressed Air Contaminants

    Energy Technology Data Exchange (ETDEWEB)

    Stroem, L

    1976-10-15

    In order to improve the technique for measuring oil and water entrained in a compressed air stream, a laboratory study has been made of some methods for sampling and measurement. For this purpose water or oil as artificial contaminants were injected in thin streams into a test loop, carrying dry compressed air. Sampling was performed in a vertical run, down-stream of the injection point. Wall attached liquid, coarse droplet flow, and fine droplet flow were sampled separately. The results were compared with two-phase flow theory and direct observation of liquid behaviour. In a study of sample transport through narrow tubes, it was observed that, below a certain liquid loading, the sample did not move, the liquid remaining stationary on the tubing wall. The basic analysis of the collected samples was made by gravimetric methods. Adsorption tubes were used with success to measure water vapour. A humidity meter with a sensor of the aluminium oxide type was found to be unreliable. Oil could be measured selectively by a flame ionization detector, the sample being pretreated in an evaporation- condensation unit

  9. Carbon and energy saving markets in compressed air

    Science.gov (United States)

    Cipollone, R.

    2015-08-01

    CO2 reduction and fossil fuel saving represent two of the cornerstones of the environmental commitments of all the countries of the world. The first engagement is of a medium to long term type, and unequivocally calls for a new energetic era. The second delays in time the fossil fuel technologies to favour an energetic transition. In order to sustain the two efforts, new immaterial markets have been established in almost all the countries of the world, whose exchanges (purchases and sales) concern CO2 emissions and equivalent fossil fuels that have not been emitted or burned. This paper goes deep inside two aspects not yet exploited: specific CO2 emissions and equivalent fossil fuel burned, as a function of compressed air produced. Reference is made to the current compressor technology, carefully analysing CAGI's (Compressed Air Gas Institute) data and integrating it with the PNUEROP (European Association of manufacturers of compressors, vacuum pumps, pneumatic tools and allied equipment) contribution on the compressor European market. On the base of energy saving estimates that could be put in place, this article also estimates the financial value of the CO2 emissions and fossil fuels avoided.

  10. Health and efficiency in trimix versus air breathing in compressed air workers.

    Science.gov (United States)

    Van Rees Vellinga, T P; Verhoeven, A C; Van Dijk, F J H; Sterk, W

    2006-01-01

    The Western Scheldt Tunneling Project in the Netherlands provided a unique opportunity to evaluate the effects of trimix usage on the health of compressed air workers and the efficiency of the project. Data analysis addressed 318 exposures to compressed air at 3.9-4.4 bar gauge and 52 exposures to trimix (25% oxygen, 25% helium, and 50% nitrogen) at 4.6-4.8 bar gauge. Results revealed three incidents of decompression sickness all of which involved the use of compressed air. During exposure to compressed air, the effects of nitrogen narcosis were manifested in operational errors and increased fatigue among the workers. When using trimix, less effort was required for breathing, and mandatory decompression times for stays of a specific duration and maximum depth were considerably shorter. We conclude that it might be rational--for both medical and operational reasons--to use breathing gases with lower nitrogen fractions (e.g., trimix) for deep-caisson work at pressures exceeding 3 bar gauge, although definitive studies are needed.

  11. Air quality in low-ventilated museum storage buildings

    DEFF Research Database (Denmark)

    Ryhl-Svendsen, Morten; Aasbjerg Jensen, Lars; Klenz Larsen, Poul

    2014-01-01

    Modern low-energy museum storage buildings are often designed for a low air exchange rate, on the order of less than 1 exchange per day. We investigated how this affected the indoor air quality in six Danish museum storage buildings. The infiltration of ambient pollutants, and the level to which...... internally-generated pollutants accumulate, were measured by passive sampling of ozone, nitrogen dioxide, and organic acids. The air exchange rates and the interchange of air between storage rooms were measured by the per-fluorocarbon tracer gas method. Ambient pollutants were reduced in concentration...

  12. 29 CFR 1926.913 - Blasting in excavation work under compressed air.

    Science.gov (United States)

    2010-07-01

    ... 29 Labor 8 2010-07-01 2010-07-01 false Blasting in excavation work under compressed air. 1926.913... Use of Explosives § 1926.913 Blasting in excavation work under compressed air. (a) Detonators and... connecting wires are connected up. (b) When detonators or explosives are brought into an air lock, no...

  13. Improving Compressed Air System Performance: A Sourcebook for Industry v3

    Energy Technology Data Exchange (ETDEWEB)

    Ron Marshall, William Scales, Gary Shafer, Paul Shaw, Paul Sheaffer, Rick Stasyshan, H.P.

    2016-03-01

    This sourcebook is designed to provide compressed air system users with a reference that outlines opportunities for system performance improvements. It is not intended to be a comprehensive technical text on improving compressed air systems, but rather a document that makes compressed air system users aware of the performance improvement potential, details some of the significant opportunities, and directs users to additional sources of assistance.

  14. Compressed air noise reductions from using advanced air gun nozzles in research and development environments.

    Science.gov (United States)

    Prieve, Kurt; Rice, Amanda; Raynor, Peter C

    2017-08-01

    The aims of this study were to evaluate sound levels produced by compressed air guns in research and development (R&D) environments, replace conventional air gun models with advanced noise-reducing air nozzles, and measure changes in sound levels to assess the effectiveness of the advanced nozzles as engineering controls for noise. Ten different R&D manufacturing areas that used compressed air guns were identified and included in the study. A-weighted sound level and Z-weighted octave band measurements were taken simultaneously using a single instrument. In each area, three sets of measurements, each lasting for 20 sec, were taken 1 m away and perpendicular to the air stream of the conventional air gun while a worker simulated typical air gun work use. Two different advanced noise-reducing air nozzles were then installed. Sound level and octave band data were collected for each of these nozzles using the same methods as for the original air guns. Both of the advanced nozzles provided sound level reductions of about 7 dBA, on average. The highest noise reductions measured were 17.2 dBA for one model and 17.7 dBA for the other. In two areas, the advanced nozzles yielded no sound level reduction, or they produced small increases in sound level. The octave band data showed strong similarities in sound level among all air gun nozzles within the 10-1,000 Hz frequency range. However, the advanced air nozzles generally had lower noise contributions in the 1,000-20,000 Hz range. The observed decreases at these higher frequencies caused the overall sound level reductions that were measured. Installing new advanced noise-reducing air nozzles can provide large sound level reductions in comparison to existing conventional nozzles, which has direct benefit for hearing conservation efforts.

  15. Compressing climate model simulations: reducing storage burden while preserving information

    Science.gov (United States)

    Hammerling, Dorit; Baker, Allison; Xu, Haiying; Clyne, John; Li, Samuel

    2017-04-01

    Climate models, which are run at high spatial and temporal resolutions, generate massive quantities of data. As our computing capabilities continue to increase, storing all of the generated data is becoming a bottleneck, which negatively affects scientific progress. It is thus important to develop methods for representing the full datasets by smaller compressed versions, which still preserve all the critical information and, as an added benefit, allow for faster read and write operations during analysis work. Traditional lossy compression algorithms, as for example used for image files, are not necessarily ideally suited for climate data. While visual appearance is relevant, climate data has additional critical features such as the preservation of extreme values and spatial and temporal gradients. Developing alternative metrics to quantify information loss in a manner that is meaningful to climate scientists is an ongoing process still in its early stages. We will provide an overview of current efforts to develop such metrics to assess existing algorithms and to guide the development of tailored compression algorithms to address this pressing challenge.

  16. Compressed-air: results of an analysis made for the Clariant company; Ergebnisse der Druckluftanalyse Clariant

    Energy Technology Data Exchange (ETDEWEB)

    Radgen, R. [Fraunhofer-Institut fuer Systemund Innovationsforschung (ISI), Karlsruhe (Germany); Stadelmann, B. [Hochschule fuer Technik und Architektur Luzern (HTA), Horw (Switzerland)

    2005-05-15

    This comprehensive, illustrated report for the Swiss Federal Office of Energy (SFOE) presents the results of a project that examined the compressed-air supply at the facilities of the Clariant company in Muttenz, Switzerland. The various compressors and compressed-air installations in the company's facilities are described and detailed technical data is presented. The control of these systems and the distribution of the compressed air is discussed. Needs, usage and consumption of compressed air is analysed at macro and detail levels. Leakage is looked at as is the dimensioning of the distribution systems. Finally, possibilities for making savings are presented.

  17. A solar air collector with integrated latent heat thermal storage

    Directory of Open Access Journals (Sweden)

    Klimes Lubomir

    2012-04-01

    Full Text Available Simulations of the behaviour of a solar air collector with integrated latent heat thermal storage were performed. The model of the collector was created with the use of coupling between TRNSYS 17 and MATLAB. Latent heat storage (Phase Change Material - PCM was integrated with the solar absorber. The model of the latent heat storage absorber was created in MATLAB and the model of the solar air collector itself was created in TRNSYS with the use of TYPE 56. The model of the latent heat storage absorber allows specification of the PCM properties as well as other parameters. The simulated air collector was the front and back pass collector with the absorber in the middle of the air cavity. Two variants were considered for comparison; the light-weight absorber made of sheet metal and the heat-storage absorber with the PCM. Simulations were performed for the climatic conditions of the Czech Republic (using TMY weather data.

  18. Compressed breathing air - the potential for evil from within.

    Science.gov (United States)

    Millar, Ian L; Mouldey, Peter G

    2008-06-01

    Human underwater activities rely on an adequate supply of breathable compressed gas, usually air, free from contaminants that could cause incapacitation underwater or post-dive or longer-term health effects. Potentially fatal but well-known hazards are hypoxia secondary to steel cylinder corrosion and carbon monoxide (CO) poisoning due to contaminated intake air. Another phenomenon may be behind some previously unexplained episodes of underwater incapacitation and perhaps death: low-level CO poisoning and/or the effects of gaseous contaminants generated within the compressor, including toluene and other volatile compounds. Many low molecular weight volatile contaminants are anaesthetic and will be potentiated by pressure and nitrogen narcosis. In sub-anaesthetic doses, impaired judgement, lowered seizure threshold and sensitisation of the heart to arrhythmias may occur. Toxic compounds can be volatilised from some compressor oils, especially mineral oils, in overheated compressors, or be created de novo under certain combinations of temperature, humidity and pressure, perhaps catalysed by metal traces from compressor wear and tear. Most volatiles can be removed by activated carbon filtration but many filters are undersized and may overload in hot, moist conditions and with short dwell times. A compressor that passes normal testing could contaminate one or more cylinders after heating up and then return to producing clean air as the filters dry and the systems cool. The scope of this problem is very unclear as air quality is tested infrequently and often inadequately, even after fatalities. More research is needed as well as better education regarding the safe operation and limitations of high-pressure breathing air compressors.

  19. A privacy-preserving solution for compressed storage and selective retrieval of genomic data.

    Science.gov (United States)

    Huang, Zhicong; Ayday, Erman; Lin, Huang; Aiyar, Raeka S; Molyneaux, Adam; Xu, Zhenyu; Fellay, Jacques; Steinmetz, Lars M; Hubaux, Jean-Pierre

    2016-12-01

    In clinical genomics, the continuous evolution of bioinformatic algorithms and sequencing platforms makes it beneficial to store patients' complete aligned genomic data in addition to variant calls relative to a reference sequence. Due to the large size of human genome sequence data files (varying from 30 GB to 200 GB depending on coverage), two major challenges facing genomics laboratories are the costs of storage and the efficiency of the initial data processing. In addition, privacy of genomic data is becoming an increasingly serious concern, yet no standard data storage solutions exist that enable compression, encryption, and selective retrieval. Here we present a privacy-preserving solution named SECRAM (Selective retrieval on Encrypted and Compressed Reference-oriented Alignment Map) for the secure storage of compressed aligned genomic data. Our solution enables selective retrieval of encrypted data and improves the efficiency of downstream analysis (e.g., variant calling). Compared with BAM, the de facto standard for storing aligned genomic data, SECRAM uses 18% less storage. Compared with CRAM, one of the most compressed nonencrypted formats (using 34% less storage than BAM), SECRAM maintains efficient compression and downstream data processing, while allowing for unprecedented levels of security in genomic data storage. Compared with previous work, the distinguishing features of SECRAM are that (1) it is position-based instead of read-based, and (2) it allows random querying of a subregion from a BAM-like file in an encrypted form. Our method thus offers a space-saving, privacy-preserving, and effective solution for the storage of clinical genomic data. © 2016 Huang et al.; Published by Cold Spring Harbor Laboratory Press.

  20. Design and Analysis of a Hydrogen Compression and Storage Station

    Science.gov (United States)

    2017-12-01

    standards relating to the production , transportation, handling, and storage of hydrogen gas. Four of CGAs standards were consulted during the design and...assessed as a low risk since the manufacturer had not experienced problems after several thousands of hours of work with their product . Future station...specified by their manufacturers . These pressure-temperature ratings are summarized for each tubing size in Table 6. A more rigorous design was

  1. The investigation on compressed air quality analysis results of nuclear power plants

    International Nuclear Information System (INIS)

    Sung, K. B.; Kim, H. K.; Kim, W. S.

    2000-01-01

    The compressed air system of nuclear power plants provides pneumatic power for both operation and control of various plant equipment, tools, and instrumentation. Included in the air supply systems are the compressors, coolers, moisture separators, dryers, filters and air receiver tanks that make up the major items of equipment. The service air system provides oil-free compressed air for general plant and maintenance use and the instrument air system provides dry, oil-free, compressed air for both nonessential and essential components and instruments. NRC recommended the periodic checks on GL88-14 'Instrument air supply system problems affecting safety-related equipment'. To ensure that the quality of the instrument air is equivalent to or exceeds the requirement s of ISA-S7.3(1975), air samples are taken at every refueling outage and analyzed for moisture, oil and particulate content. The over all results are satisfied the requirements of ISA-S7.3

  2. Data Blocks: hybrid OLTP and OLAP on compressed storage using both vectorization and compilation

    NARCIS (Netherlands)

    H. Lang (Harald); T. Mühlbauer; F. Funke; P.A. Boncz (Peter); T. Neumann (Thomas); A. Kemper (Alfons)

    2016-01-01

    htmlabstractThis work aims at reducing the main-memory footprint in high performance hybrid OLTP & OLAP databases, while retaining high query performance and transactional throughput. For this purpose, an innovative compressed columnar storage format for cold data, called Data Blocks is introduced.

  3. Data Blocks : Hybrid OLTP and OLAP on compressed storage using both vectorization and compilation

    NARCIS (Netherlands)

    Lang, Harald; Mühlbauer, Tobias; Funke, Florian; Boncz, Peter; Neumann, Thomas; Kemper, Alfons

    2016-01-01

    This work aims at reducing the main-memory footprint in high performance hybrid OLTP&OLAP databases, while retaining high query performance and transactional throughput. For this purpose, an innovative compressed columnar storage format for cold data, called Data Blocks is introduced. Data Blocks

  4. Large-site air-storage gas-turbine plants in electricity networks

    Energy Technology Data Exchange (ETDEWEB)

    Herbst, H C

    1980-08-01

    The article gives a detailed description of the construction and the operation of the 290 MW air-storage gas-turbine power station at the town of Huntorf. The cavities of a 300,000 cbm storage capacity needed for accomodating compressed air have been solution-mined in a salt dome at a depth of c. 700 m. The air-mass-flow-controlled gas turbine consists of a 6-stage HP part and a 5-stage LP part with a combustion chamber each. The turbine is used to cover peak loads, whereas slack periods are covered by the generator which drives to air compressors connected in series to refill the underground compressed-air stores. Since December 1978, the plant has been in operation. As a gas turbine, it has attained a high level of start frequency, indeed, with its 400 starts within the first 5 months. Energy cost of this power station range within the optimum (between half and full load) at about 70% of the energy cost required by a conventionally natural-gas-fired turbine.

  5. A comparative analysis of the cryo-compression and cryo-adsorption hydrogen storage methods

    Energy Technology Data Exchange (ETDEWEB)

    Petitpas, G [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Benard, P [Universite du Quebec a Trois-Rivieres (Canada); Klebanoff, L E [Sandia National Lab. (SNL-CA), Livermore, CA (United States); Xiao, J [Universite du Quebec a Trois-Rivieres (Canada); Aceves, S M [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2014-07-01

    While conventional low-pressure LH₂ dewars have existed for decades, advanced methods of cryogenic hydrogen storage have recently been developed. These advanced methods are cryo-compression and cryo-adsorption hydrogen storage, which operate best in the temperature range 30–100 K. We present a comparative analysis of both approaches for cryogenic hydrogen storage, examining how pressure and/or sorbent materials are used to effectively increase onboard H₂ density and dormancy. We start by reviewing some basic aspects of LH₂ properties and conventional means of storing it. From there we describe the cryo-compression and cryo-adsorption hydrogen storage methods, and then explore the relationship between them, clarifying the materials science and physics of the two approaches in trying to solve the same hydrogen storage task (~5–8 kg H₂, typical of light duty vehicles). Assuming that the balance of plant and the available volume for the storage system in the vehicle are identical for both approaches, the comparison focuses on how the respective storage capacities, vessel weight and dormancy vary as a function of temperature, pressure and type of cryo-adsorption material (especially, powder MOF-5 and MIL-101). By performing a comparative analysis, we clarify the science of each approach individually, identify the regimes where the attributes of each can be maximized, elucidate the properties of these systems during refueling, and probe the possible benefits of a combined “hybrid” system with both cryo-adsorption and cryo-compression phenomena operating at the same time. In addition the relationships found between onboard H₂ capacity, pressure vessel and/or sorbent mass and dormancy as a function of rated pressure, type of sorbent material and fueling conditions are useful as general designing guidelines in future engineering efforts using these two hydrogen storage approaches.

  6. Comparative investigation of thermoelectric air-conditioners versus vapour compression and absorption air-conditioners

    International Nuclear Information System (INIS)

    Riffat, S.B.; Qiu Guoquan

    2004-01-01

    This paper compares the performance of three types of domestic air-conditioners, namely the vapour compression air-conditioner (VCAC), the absorption air-conditioner (AAC) and the thermoelectric air-conditioner (TEAC). The basic cycles of the three types of air-conditioning systems are described and methods to calculate their coefficients of performance are presented. General specification data for each type of air-conditioner are given, and performance characteristics are presented. The comparison shows that although VCACs have the advantages of high COP and low purchase price, use of these systems will be phased out due to their contribution to the greenhouse effect and depletion of the ozone layer. AACs are generally bulky, complex and expensive but operate on thermal energy, so their operational consumption is low. TEACs are environmental friendly, simple and reliable but still very expensive at present. Their low COP is an additional factor limiting their application for domestic cooling. TEACs however, have a large potential market as air-conditioners for small enclosures, such as cars and submarine cabins, where the power consumption would be low, or safety and reliability would be important

  7. Chapter 22: Compressed Air Evaluation Protocol. The Uniform Methods Project: Methods for Determining Energy Efficiency Savings for Specific Measures

    Energy Technology Data Exchange (ETDEWEB)

    Kurnik, Charles W [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Benton, Nathanael [Nexant, Inc., San Francisco, CA (United States); Burns, Patrick [Nexant, Inc., San Francisco, CA (United States)

    2017-10-18

    Compressed-air systems are used widely throughout industry for many operations, including pneumatic tools, packaging and automation equipment, conveyors, and other industrial process operations. Compressed-air systems are defined as a group of subsystems composed of air compressors, air treatment equipment, controls, piping, pneumatic tools, pneumatically powered machinery, and process applications using compressed air. A compressed-air system has three primary functional subsystems: supply, distribution, and demand. Air compressors are the primary energy consumers in a compressed-air system and are the primary focus of this protocol. The two compressed-air energy efficiency measures specifically addressed in this protocol are: High-efficiency/variable speed drive (VSD) compressor replacing modulating, load/unload, or constant-speed compressor; and Compressed-air leak survey and repairs. This protocol provides direction on how to reliably verify savings from these two measures using a consistent approach for each.

  8. Operability Test Report for 241-U Compressed Air System and heat pump

    International Nuclear Information System (INIS)

    Rensink, G.E.

    1995-01-01

    The 241-U-701 compressed air system supplies instrument quality compressed air to Tank Farm 241-U. The system was upgraded. The operability test showed that the system operates within its intended design parameters. System performance was monitored, recorded, and used to identify areas of concern. Exceptions to the OTP and additional items for safe system performance were minimal and have been resolved; the air system is ready for Operation's use

  9. Exergy Analysis of the Revolving Vane Compressed Air Engine

    Directory of Open Access Journals (Sweden)

    Alison Subiantoro

    2016-01-01

    Full Text Available Exergy analysis was applied to a revolving vane compressed air engine. The engine had a swept volume of 30 cm3. At the benchmark conditions, the suction pressure was 8 bar, the discharge pressure was 1 bar, and the operating speed was 3,000 rev·min−1. It was found that the engine had a second-law efficiency of 29.6% at the benchmark conditions. The contributors of exergy loss were friction (49%, throttling (38%, heat transfer (12%, and fluid mixing (1%. A parametric study was also conducted. The parameters to be examined were suction reservoir pressure (4 to 12 bar, operating speed (2,400 to 3,600 rev·min−1, and rotational cylinder inertia (0.94 to 2.81 g·mm2. The study found that a higher suction reservoir pressure initially increased the second-law efficiency but then plateaued at about 30%. With a higher operating speed and a higher cylinder inertia, second-law efficiency decreased. As compared to suction pressure and operating speed, cylinder inertia is the most practical and significant to be modified.

  10. A cost-effective compressed air generation for manufacturing using modified microturbines

    International Nuclear Information System (INIS)

    Eret, Petr

    2016-01-01

    Highlights: • A new cost-effective way of compressed air generation for manufacturing in SME is proposed. • The approach is based on a modified microturbine configuration. • Thermodynamic and life cycle analyses are presented and economic benefit is demonstrated. - Abstract: Compressed air is an irreplaceable energy source for some manufacturing processes, and is also common in applications even when there are alternatives. As a result, compressed air is a key utility in manufacturing industry, but unfortunately the cost of compressed air production is one of the most expensive processes in a manufacturing facility. In order to reduce the compressed air generation cost an unconventional way using a microturbine configuration is proposed. The concept is based on an extraction of a certain amount of compressed air from/after the compressor with the residual air flowing to the turbine to produce sufficient back power to drive the compressor. A thermodynamic and life cycle analysis are presented for several system variations, including a simple cycle without a recuperator and a complex configuration with an intercooler, recuperator and reheating. The study is based on the typical requirements (i.e. quantity, pressure) for a small to medium sized industrial compressed air system. The analysis is focused on the North American market due to the low price of natural gas. The lowest life cycle cost alternative is represented by a microturbine concept with a recuperator, air extraction after partial compression, intercooler and aftercooler. A comparison of an electric motor and conventional microturbine prime movers demonstrates the economic benefit of the proposed compressed air generation method, for the design parameters and utility prices considered.

  11. Compressed Air Quality, A Case Study In Paiton Coal Fired Power Plant Unit 1 And 2

    Science.gov (United States)

    Indah, Nur; Kusuma, Yuriadi; Mardani

    2018-03-01

    The compressed air system becomes part of a very important utility system in a Plant, including the Steam Power Plant. In PLN’S coal fired power plant, Paiton units 1 and 2, there are four Centrifugal air compressor types, which produce compressed air as much as 5.652 cfm and with electric power capacity of 1200 kW. Electricity consumption to operate centrifugal compressor is 7.104.117 kWh per year. Compressed air generation is not only sufficient in quantity (flow rate) but also meets the required air quality standards. compressed air at Steam Power Plant is used for; service air, Instrument air, and for fly Ash. This study aims to measure some important parameters related to air quality, followed by potential disturbance analysis, equipment breakdown or reduction of energy consumption from existing compressed air conditions. These measurements include counting the number of dust particles, moisture content, relative humidity, and also compressed air pressure. From the measurements, the compressed air pressure generated by the compressor is about 8.4 barg and decreased to 7.7 barg at the furthest point, so the pressure drop is 0.63 barg, this number satisfies the needs in the end user. The measurement of the number of particles contained in compressed air, for particle of 0.3 micron reaches 170,752 particles, while for the particle size 0.5 micron reaches 45,245 particles. Measurements of particles conducted at several points of measurement. For some point measurements the number of dust particle exceeds the standard set by ISO 8573.1-2010 and also NACE Code, so it needs to be improved on the air treatment process. To see the amount of moisture content in compressed air, it is done by measuring pressure dew point temperature (PDP). Measurements were made at several points with results ranging from -28.4 to 30.9 °C. The recommendation of improving compressed air quality in steam power plant, Paiton unit 1 and 2 has the potential to extend the life of

  12. Operability test procedure for 241-U compressed air system and heat pump

    International Nuclear Information System (INIS)

    Freeman, R.D.

    1994-01-01

    The 241-U-701 compressed air system supplies instrument quality compressed air to Tank Farm 241-U. The supply piping to the 241-U Tank Farm is not included in the modification. Modifications to the 241-U-701 compressed air system include installation of a 15 HP Reciprocating Air Compressor, Ingersoll-Rand Model 10T3NLM-E15; an air dryer, Hankinson, Model DH-45; and miscellaneous system equipment and piping (valves, filters, etc.) to meet the design. A newly installed heat pump allows the compressor to operate within an enclosed relatively dust free atmosphere and keeps the compressor room within a standard acceptable temperature range, which makes possible efficient compressor operation, reduces maintenance, and maximizes compressor operating life. This document is an Operability Test Procedure (OTP) which will further verify (in addition to the Acceptance Test Procedure) that the 241-U-701 compressed air system and heat pump operate within their intended design parameters. The activities defined in this OTP will be performed to ensure the performance of the new compressed air system will be adequate, reliable and efficient. Completion of this OTP and sign off of the OTP Acceptance of Test Results is necessary for turnover of the compressed air system from Engineering to Operations

  13. Performance enhancement of a subcooled cold storage air conditioning system

    International Nuclear Information System (INIS)

    Hsiao, M.-J.; Cheng, C.-H.; Huang, M.-C.; Chen, S.-L.

    2009-01-01

    This article experimentally investigates the enhancement of thermal performance for an air conditioning system utilizing a cold storage unit as a subcooler. The cold storage unit is composed of an energy storage tank, liquid-side heat exchanger, suction-side heat exchanger and energy storage material (ESM), water. When the cooling load is lower than the nominal cooling capacity of the system, the cold storage unit can store extra cold energy of the system to subcool the condenser outlet refrigerant. Hence, both the cooling capacity and coefficient of performance (COP) of the system will be increased. This experiment tests the two operation modes: subcooled mode with energy storage and non-subcooled mode without energy storage. The results show that for fixed cooling loads at 3.05 kW, 3.5 kW and 3.95 kW, the COP of the subcooled mode are 16.0%, 15.6% and 14.1% higher than those of the non-subcooled mode, respectively. In the varied cooling load experiments, the COP of the subcooled cold storage air conditioning system is 15.3% higher than the conventional system.

  14. Dry storage systems with free convection air cooling

    International Nuclear Information System (INIS)

    Kioes, S.R.

    1980-01-01

    Several design principles to remove heat from the spent fuel by free air convection are illustrated and described. The key safety considerations were felt to be: loss of coolant is impossible as the passive system uses air as a coolant; overheating is precluded because as the temperatures of the containers rises the coolant flow rate increases; mass of the storage building provides a large heat sink and therefore a rapid temperature rise is impossible; and lack of any active external support requirements makes the cooling process less likely to equipment or operator failures. An example of this type of storage already exists. The German HTGR is operated with spherical graphite fuel elements which are stored in canister and in storage cells. The concept is a double cooling system with free convection inside the cells and heat exchange via two side walls of the cell to the ambient air in the cooling ducts. Technical description of the TN 1300 cask is also presented

  15. Large-scale electrophysiology: acquisition, compression, encryption, and storage of big data.

    Science.gov (United States)

    Brinkmann, Benjamin H; Bower, Mark R; Stengel, Keith A; Worrell, Gregory A; Stead, Matt

    2009-05-30

    The use of large-scale electrophysiology to obtain high spatiotemporal resolution brain recordings (>100 channels) capable of probing the range of neural activity from local field potential oscillations to single-neuron action potentials presents new challenges for data acquisition, storage, and analysis. Our group is currently performing continuous, long-term electrophysiological recordings in human subjects undergoing evaluation for epilepsy surgery using hybrid intracranial electrodes composed of up to 320 micro- and clinical macroelectrode arrays. DC-capable amplifiers, sampling at 32kHz per channel with 18-bits of A/D resolution are capable of resolving extracellular voltages spanning single-neuron action potentials, high frequency oscillations, and high amplitude ultra-slow activity, but this approach generates 3 terabytes of data per day (at 4 bytes per sample) using current data formats. Data compression can provide several practical benefits, but only if data can be compressed and appended to files in real-time in a format that allows random access to data segments of varying size. Here we describe a state-of-the-art, scalable, electrophysiology platform designed for acquisition, compression, encryption, and storage of large-scale data. Data are stored in a file format that incorporates lossless data compression using range-encoded differences, a 32-bit cyclically redundant checksum to ensure data integrity, and 128-bit encryption for protection of patient information.

  16. Contamination of hospital compressed air with nitric oxide: unwitting replacement therapy.

    Science.gov (United States)

    Pinsky, M R; Genc, F; Lee, K H; Delgado, E

    1997-06-01

    Inhaled nitric oxide (NO) at levels between 5 and 80 ppm has been used experimentally to treat a variety of conditions. NO also is a common environmental air pollutant in industrial regions. As compressed hospital air is drawn from the local environment, we speculated that it may contain NO contamination, which, if present, would provide unwitting inhaled NO therapy to all subjects respiring this compressed gas. NO levels were measured twice daily from ambient hospital air and compressed gas sources driving positive pressure ventilation from two adjacent hospitals and compared with NO levels reported daily by local Environmental Protection Agency sources. An NO chemiluminescence analyzer (Sievers 270B; Boulder, Colo) sensitive to > or =2 parts per billion was used to measure NO levels in ambient air and compressed gas. NO levels in ambient air and hospital compressed air covaried from day to day, and absolute levels of NO differed between hospitals with the difference never exceeding 1.4 ppm (range, 0 to 1.4 ppm; median, 0.07 ppm). The hospital with the highest usage level of compressed air had the highest levels of NO, which approximated ambient levels of NO. NO levels were lowest on weekends in both hospitals. We also documented inadvertent NO contamination in one hospital occurring over 5 days, which corresponded to welding activity near the intake port for fresh gas. This contamination resulted in system-wide NO levels of 5 to 8 ppm. Hospital compressed air contains highly variable levels of NO that tend to covary with ambient NO levels and to be highest when the rate of usage is high enough to preclude natural degradation of NO in 21% oxygen. Assuming that inhaled NO may alter gas exchange, pulmonary hemodynamics, and outcome from acute lung injury, the role of unwitting variable NO of hospital compressed air needs to be evaluated.

  17. Safety for Compressed Gas and Air Equipment. Module SH-26. Safety and Health.

    Science.gov (United States)

    Center for Occupational Research and Development, Inc., Waco, TX.

    This student module on safety for compressed gas and air equipment is one of 50 modules concerned with job safety and health. This module presents technical data about commonly used gases and stresses the procedures necessary for safe handling of compressed gases. Following the introduction, 14 objectives (each keyed to a page in the text) the…

  18. Operability Test Report for 241-T compressed air system and heat pump

    International Nuclear Information System (INIS)

    Freeman, R.D.

    1995-02-01

    This Operability Test Report (OTR) documents the results of functional testing performed on the operating parameters of the 241-T-701 Compressed Air System. The System was successfully installed and tested per work package 2W-92-01172

  19. Project of energy saving in compressed air; Proyecto de ahorro de energia en aire comprimido

    Energy Technology Data Exchange (ETDEWEB)

    Automatizacion, Productividad y Calidad S.A. de C.V. Puebla, (Mexico)

    2005-07-01

    The objective of this project is to reduce the operation costs by means of the energy saving through the use of the compressed air system. For this purpose the solenoid valves controlled per time and the manually acted valves of sphere must be replaced by pneumatic purges that remove from the system the condensed humidity without discharging air and which act automatically when the water reaches the level of unloading in its deposit. The pressure level is the reduction of the operation rank of pressure in the compressors, satisfying the operation requirements of the process equipment. [Spanish] El objetivo de este proyecto es reducir el costo de operacion mediante el ahorro de energia en la utilizacion del sistema de aire comprimido. Para ello se tienen que remplazar las valvulas solenoides controladas por tiempo y valvulas de esfera actuadas manualmente por purgas neumaticas que remueven del sistema la humedad condensada sin descargar aire y que actuan en forma automatica al alcanzar el agua el nivel de descarga en su deposito. El nivel de presion es la reduccion del rango de operacion de presion de los compresores, satisfaciendo los requerimientos de operacion de los equipos de proceso.

  20. Compressed air as a source of inhaled oxidants in intensive care units.

    Science.gov (United States)

    Thibeault, D W; Rezaiekhaligh, M H; Ekekezie, I; Truog, W E

    1999-01-01

    Exhaled gas from mechanically ventilated preterm infants was found to have similar oxidant concentrations, regardless of lung disease, leading to the hypothesis that wall outlet gases were an oxidant source. Oxidants in compressed room air and oxygen from wall outlets were assessed in three hospitals. Samples were collected by flowing wall outlet gas through a heated humidifier and an ice-packed condenser. Nitric oxide (NO) was measured in intensive care room air and in compressed air with and without a charcoal filter using a Sievers NOA280 nitric oxide analyzer (Boulder, CO). Oxidants were measured by spectrophotometry and expressed as nMol equivalents of H2O2/mL. The quantity of oxidant was also expressed as amount of Vitamin C (nMol/mL) added until the oxidant was nondetectable. This quantity of Vitamin C was also expressed in Trolox Equivalent Antioxidant Capacity (TEAC) units (mMol/L). Free and total chlorine were measured with a Chlorine Photometer. Oxidants were not found in compressed oxygen and were only found in compressed air when the compression method used tap water. At a compressed room air gas flow of 1.5 L/min, the total volume of condensate was 20.2 +/- 1 mL/hr. The oxidant concentration was 1.52 +/- 0.09 nMol/mL equivalents of H2O2/mL of sample and 30.8 +/- 1.2 nMol/hr; 17.9% of that found in tap water. Oxidant reduction required 2.05 +/-0.12 nMol/mL vitamin C, (1.78 +/- 0.1 x 10(-3) TEAC units). Free and total chlorine in tap water were 0.3 +/- 0.02 mg/mL and 2.9 +/- 0.002 mg/mL, respectively. Outlet gas contained 0.4 +/- 0.06 mg/mL and 0.07 + 0.01 mg/mL total and free chlorine, respectively; both 14% of tap water. When a charcoal filter was installed in the hospital with oxidants in compressed air, oxidants were completely removed. Nursery room air contained 12.4 +/- 0.5 ppb NO; compressed wall air without a charcoal filter, 8.1 +/- 0.1 ppb and compressed air with a charcoal filter 12.5 +/- 0.5 ppb. A charcoal filter does not remove NO. (Table

  1. Methodology for the energy analysis of compressed air systems; Metodologia para analisis energetico de sistemas de aire comprimido

    Energy Technology Data Exchange (ETDEWEB)

    Ramirez, T; Ambriz, J J; Romero, H [Universidad Autonoma Metropolitana-Iztapalapa, Mexico, D. F. (Mexico)

    1993-12-31

    In this paper a methodology for the diagnosis of compressed air systems, for the identification of the potential energy saving is presented. The methodology consists in detecting the largest number of possible ways of energy saving. For this purpose it is divided into three parts: 1. Compressed air generation. 2. Compressed air distribution. 3. Compressed air users. For each one of the parts, the type of information required to perform the diagnosis study, as well as the necessary measuring equipment needed, is indicated. Afterwards, the possible saving ways that can be found and the ones that can be feasible, are analyzed. [Espanol] En este trabajo se presenta una metodologia para diagnosticar sistemas de aire comprimido, para identificar los potenciales de ahorro de energia. La metodologia consiste en detectar el mayor numero de posibles medidas de ahorro, para lo cual se divide en tres partes: 1. Generacion de aire comprimido. 2. Distribucion del aire comprimido. 3 Usuarios de aire comprimido. Para cada una de las partes se indica el tipo de informacion requerida para realizar el estudio de diagnostico, asi como el uso de equipo necesario de medicion. Despues se analizan las posibles medidas de ahorro que se pueden encontrar y las que pueden ser viables.

  2. Methodology for the energy analysis of compressed air systems; Metodologia para analisis energetico de sistemas de aire comprimido

    Energy Technology Data Exchange (ETDEWEB)

    Ramirez, T.; Ambriz, J. J.; Romero, H. [Universidad Autonoma Metropolitana-Iztapalapa, Mexico, D. F. (Mexico)

    1992-12-31

    In this paper a methodology for the diagnosis of compressed air systems, for the identification of the potential energy saving is presented. The methodology consists in detecting the largest number of possible ways of energy saving. For this purpose it is divided into three parts: 1. Compressed air generation. 2. Compressed air distribution. 3. Compressed air users. For each one of the parts, the type of information required to perform the diagnosis study, as well as the necessary measuring equipment needed, is indicated. Afterwards, the possible saving ways that can be found and the ones that can be feasible, are analyzed. [Espanol] En este trabajo se presenta una metodologia para diagnosticar sistemas de aire comprimido, para identificar los potenciales de ahorro de energia. La metodologia consiste en detectar el mayor numero de posibles medidas de ahorro, para lo cual se divide en tres partes: 1. Generacion de aire comprimido. 2. Distribucion del aire comprimido. 3 Usuarios de aire comprimido. Para cada una de las partes se indica el tipo de informacion requerida para realizar el estudio de diagnostico, asi como el uso de equipo necesario de medicion. Despues se analizan las posibles medidas de ahorro que se pueden encontrar y las que pueden ser viables.

  3. Hydro-pneumatic accumulators for vehicles kinetic energy storage: Influence of gas compressibility and thermal losses on storage capability

    International Nuclear Information System (INIS)

    Puddu, Pierpaolo; Paderi, Maurizio

    2013-01-01

    In this work the differences between the thermodynamic behaviour of real and ideal gases are analysed to determine their influence on the processes of compression and expansion of a gas-charged accumulator. The behaviour of real gas has a significant influence on the size of accumulators used for Kinetic Energy Recovery of vehicles. In particular, it is underscored that the accumulator's design, based on ideal gas behaviour, provides undersized accumulators and therefore makes impossible the complete energy recovery for Hydraulic Energy Storage Systems (HES). The analysis of the thermodynamic properties of gases has shown that the main differences between ideal and real behaviour are due to gas compressibility. A mathematical model of a gas-charged accumulator is developed in order to analyse its real behaviour in presence of irreversible heat transfer and viscous losses. The simulation process of charging and discharging of a hydro-pneumatic accumulator, makes it clear that hydrodynamic and thermal losses are responsible for the characteristic hysteresis cycle on the p–V diagram. Different gases are tested as charged fluid of a hydro-pneumatic accumulator to simulate cyclic processes of charge and discharge. Results show different characteristics in terms of volumetric gas properties, thermal time-constant and thermal efficiency of the accumulator. - Highlights: • A dynamic model of a gas charged accumulator was developed. • Gas compressibility significantly influences the size of high-pressure accumulators. • A hysteresis loop is indicative of the thermal energy losses. • Loss increases with increasing the period of the cyclic process. • Thermal time constant is different from compression to expansion

  4. Buffer thermal energy storage for an air Brayton solar engine

    Science.gov (United States)

    Strumpf, H. J.; Barr, K. P.

    1981-01-01

    The application of latent-heat buffer thermal energy storage to a point-focusing solar receiver equipped with an air Brayton engine was studied. To demonstrate the effect of buffer thermal energy storage on engine operation, a computer program was written which models the recuperator, receiver, and thermal storage device as finite-element thermal masses. Actual operating or predicted performance data are used for all components, including the rotating equipment. Based on insolation input and a specified control scheme, the program predicts the Brayton engine operation, including flows, temperatures, and pressures for the various components, along with the engine output power. An economic parametric study indicates that the economic viability of buffer thermal energy storage is largely a function of the achievable engine life.

  5. Thermodynamic analysis of a liquid air energy storage system

    International Nuclear Information System (INIS)

    Guizzi, Giuseppe Leo; Manno, Michele; Tolomei, Ludovica Maria; Vitali, Ruggero Maria

    2015-01-01

    The rapid increase in the share of electricity generation from renewable energy sources is having a profound impact on the power sector; one of the most relevant effects of this trend is the increased importance of energy storage systems, which can be used to smooth out peaks and troughs of production from renewable energy sources. Besides their role in balancing the electric grid, energy storage systems may provide also several other useful services, such as price arbitrage, stabilizing conventional generation, etc.; therefore, it is not surprising that many research projects are under way in order to explore the potentials of new technologies for electric energy storage. This paper presents a thermodynamic analysis of a cryogenic energy storage system, based on air liquefaction and storage in an insulated vessel. This technology is attractive thanks to its independence from geographical constraints and because it can be scaled up easily to grid-scale ratings, but it is affected by a low round-trip efficiency due to the energy intensive process of air liquefaction. The present work aims to assess the efficiency of such a system and to identify if and how it can achieve an acceptable round-trip efficiency (in the order of 50–60%).

  6. Cerebral magnetic resonance imaging of compressed air divers in diving accidents.

    Science.gov (United States)

    Gao, G K; Wu, D; Yang, Y; Yu, T; Xue, J; Wang, X; Jiang, Y P

    2009-01-01

    To investigate the characteristics of the cerebral magnetic resonance imaging (MRI) of compressed air divers in diving accidents, we conducted an observational case series study. MRI of brain were examined and analysed on seven cases compressed air divers complicated with cerebral arterial gas embolism CAGE. There were some characteristics of cerebral injury: (1) Multiple lesions; (2) larger size; (3) Susceptible to parietal and frontal lobe; (4) Both cortical grey matter and subcortical white matter can be affected; (5) Cerebellum is also the target of air embolism. The MRI of brain is an sensitive method for detecting cerebral lesions in compressed air divers in diving accidents. The MRI should be finished on divers in diving accidents within 5 days.

  7. Saturated-unsaturated flow to a partially penetrating well with storage in a compressible aquifer

    Science.gov (United States)

    Mishra, P. K.; Neuman, S. P.

    2010-12-01

    Mishra and Neuman [2010] developed an analytical solution for flow to a partially penetrating well of zero radius in a compressible unconfined aquifer that allows inferring its saturated and unsaturated hydraulic properties from responses recorded in the saturated and/or the unsaturated zone. We extend their solution to the case of a finite diameter pumping well with storage. Both solutions account for horizontal as well as vertical flows throughout the system. We investigate the effects of storage in the pumping well and delayed piezometer response on drawdowns in the saturated and unsaturated zones as functions of position and time; validate our solution against numerical simulations of drawdown in a synthetic aquifer having unsaturated properties described by the van Genuchten - Mualem constitutive model; and use our solution to analyze drawdown data from a pumping test conducted at the Borden site in Ontario, Canada.

  8. Design Fabrication And Partial-Analysis Of A 2-Wheeler Prototype That Runs On Compressed Air

    OpenAIRE

    P Vinay; Srivatsa G R; Venkatesh Datta; Dinesh Kumar A; Ramesha N; Dr. H K Govindaraju

    2015-01-01

    Abstract The primary objective of the project is to create a prototype of a purely air powered motorcycle by retrofitting its internal combustion engine to run on compressed air. Firstly the conventional spark plug was replaced with a solenoid valve. The solenoid valve was initially actuated using a reed switch and magnet duo but then later replaced with an optical crank position sensor circuit due to reasons that include lack of control over the amount of air injected during each stroke and ...

  9. Thermoeconomic evaluation of air conditioning system with chilled water storage

    International Nuclear Information System (INIS)

    Lin, Hu; Li, Xin-hong; Cheng, Peng-sheng; Xu, Bu-gong

    2014-01-01

    Highlights: • A new thermoeconomic evaluation methodology has been presented. • The relationship between thermodynamic and economic performances has been revealed. • A key point for thermal storage technology further application is discovered. • A system has been analyzed via the new method and EUD method. - Abstract: As a good load shifting technology for power grid, chilled energy storage has been paid more and more attention, but it always consumes more energy than traditional air conditioning system, and the performance analysis is mostly from the viewpoint of peak-valley power price to get cost saving. The paper presents a thermoeconomic evaluation methodology for the system with chilled energy storage, by which thermodynamic performance influence on cost saving has been revealed. And a system with chilled storage has been analyzed, which can save more than 15% of power cost with no energy consumption increment, and just certain difference between peak and valley power prices can make the technology for good economic application. The results show that difference between peak and valley power prices is not the only factor on economic performance, thermodynamic performance of the storage system is the more important factor, and too big price difference is a barrier for its application, instead of for more cost saving. All of these give a new direction for thermal storage technology application

  10. Vapour and air bubble collapse analysis in viscous compressible water

    Directory of Open Access Journals (Sweden)

    Gil Bazanini

    2001-01-01

    Full Text Available Numerical simulations of the collapse of bubbles (or cavities are shown, using the finite difference method, taking into account the compressibility of the liquid, expected to occur in the final stages of the collapse process. Results are compared with experimental and theoretical data for incompressible liquids, to see the influence of the compressibility of the water in the bubble collapse. Pressure fields values are calculated in an area of 800 x 800 mm, for the case of one bubble under the hypothesis of spherical symmetry. Results are shown as radius versus time curves for the collapse (to compare collapse times, and pressure curves in the plane, for pressure fields. Such calculations are new because of their general point of view, since the existing works do not take into account the existence of vapour in the bubble, neither show the pressure fields seen here. It is also expected to see the influence of the compressibility of the water in the collapse time, and in the pressure field, when comparing pressure values.

  11. Energy storage

    International Nuclear Information System (INIS)

    Odru, P.

    2010-01-01

    This book proposes a broad overview of the technologies developed in the domains of on-board electricity storage (batteries, super-capacitors, flywheels), stationary storage (hydraulic dams, compressed air, batteries and hydrogen), and heat storage (sensible, latent and sorption) together with their relative efficiency, their expected developments and what advantages they can offer. Eminent specialists of this domain have participated to the redaction of this book, all being members of the Tuck's Foundation 'IDees' think tank. (J.S.)

  12. Exergy storage to exploit solar energy in air conditioning

    Energy Technology Data Exchange (ETDEWEB)

    Navarrete-Gonzalez, J.J.; Torres-Reyes, E. [Guanajuato Univ., Guanajuato (Mexico). Inst. de Investigaciones Cientificas; Cervantes-de Gortari, J.G. [Univ. of Cuidad, Mexico City (Mexico). Dept. de Termoenergia y Mejoramiento Ambiental

    2006-07-01

    A thermodynamic procedure was developed to analyze the exergy of a rock bed thermal storage unit that used solar power to acclimatize a pig farm. Thermal behaviour was described by means of a control volume that included the entire system and assumed a unidirectional air flow and an adiabatic process. The thermodynamic properties of the system were determined as a function of the experimental temperature profiles developed during thermal storage from solar to thermal energy conversion provided by a solar collector at a fixed mass rate of air flow. Experimental data were used to calculate the energy yield and to determine the entropy generation inside the system. The aim of the study was to determine how well the thermodynamic model matched the real data obtained experimentally during normal operating conditions. Results indicated that an exergy accumulation existed inside the control volume, which was the net result of the energy gain during the heating process. However, entropy generation due to irreversibilities was studied for just 1 air flow. Further research is needed to establish a semi-empirical model of the process with the minimum of entropy generation. It was concluded that the thermal energy storage system was suitable for use in pig farms. 5 refs., 8 figs.

  13. Annular Air Leaks in a liquid hydrogen storage tank

    Science.gov (United States)

    Krenn, AG; Youngquist, RC; Starr, SO

    2017-12-01

    Large liquid hydrogen (LH2) storage tanks are vital infrastructure for NASA, the DOD, and industrial users. Over time, air may leak into the evacuated, perlite filled annular region of these tanks. Once inside, the extremely low temperatures will cause most of the air to freeze. If a significant mass of air is allowed to accumulate, severe damage can result from nominal draining operations. Collection of liquid air on the outer shell may chill it below its ductility range, resulting in fracture. Testing and analysis to quantify the thermal conductivity of perlite that has nitrogen frozen into its interstitial spaces and to determine the void fraction of frozen nitrogen within a perlite/frozen nitrogen mixture is presented. General equations to evaluate methods for removing frozen air, while avoiding fracture, are developed. A hypothetical leak is imposed on an existing tank geometry and a full analysis of that leak is detailed. This analysis includes a thermal model of the tank and a time-to-failure calculation. Approaches to safely remove the frozen air are analyzed, leading to the conclusion that the most feasible approach is to allow the frozen air to melt and to use a water stream to prevent the outer shell from chilling.

  14. Hydrofluoric acid burn resulting from ignition of gas from a compressed air duster.

    Science.gov (United States)

    Foster, Kevin N; Jones, LouAnn; Caruso, Daniel M

    2003-01-01

    A young female suffered burns to her hand after the ignition of gas from a compressed air duster. After debridement and dressing, the patient continued to have pain out of proportion to injury that was refractory to intravenous morphine. The material safety data sheet revealed that the chemical used was 1,1-difluoroethane. High temperatures can cause decompensation to form hydrofluoric acid. Calcium gluconate gel was applied topically to the patient's burns, which caused prompt and complete relief of her pain. A review of different compressed air duster products revealed that the main ingredient in each was a halogenated hydrocarbon. Although not considered flammable, all products have warnings regarding the possibility of ignition under various circumstances. Ignition of the gas in compressed air cleaners not only can cause flame burns, it can also cause chemical damage from exposure to hydrogen and fluoride ions. Prompt recognition and treatment is necessary to prevent severe injury.

  15. Increasing Lift by Releasing Compressed Air on Suction Side of Airfoil

    Science.gov (United States)

    Seewald, F

    1927-01-01

    The investigation was limited chiefly to the region of high angles of attack since it is only in this region that any considerable change in the character of the flow can be expected from such artificial aids. The slot, through which compressed air was blown, was formed by two pieces of sheet steel connected by screws at intervals of about 5 cm. It was intended to regulate the width of the slot by means of these screws. Much more compressed air was required than was originally supposed, hence all the delivery pipes were much too small. This experiment, therefore, is to be regarded as only a preliminary one.

  16. [Bone and joint changes due to compressed air in divers and Caisson workers (author's transl)].

    Science.gov (United States)

    Poser, H; Gabriel-Jürgens, P

    1977-02-01

    The radiological and morphological changes of Caisson disease in the skeleton are well known. The findings of interest to radiologists are described. Because of its position, its was possible to review a large number of divers in Kiel; these have been under observation for years, and even decades. The development, manifestation and course of chronic skeletal changes due to compressed air are described to compressed air are described and, according to severity, are classified into types 1 to 4. Late changes are discussed in detail, since these are of importance in relation to compensation.

  17. A preliminary study on the optimal configuration and operating range of a “microgrid scale” air liquefaction plant for Liquid Air Energy Storage

    International Nuclear Information System (INIS)

    Borri, E.; Tafone, A.; Romagnoli, A.; Comodi, G.

    2017-01-01

    Highlights: • A liquefaction cycle for a microgrid scale Liquid Air Energy Storage is proposed. • Different liquefaction cycles are compared by means of parametric analysis. • The optimal configuration proposed is a Kapitza cycle with two stage compression. • The specific consumption of the optimal configuration is around 700 kW h/t. • Specific consumption reduces to 532 kW h/t if a pressurized phase separator is used. - Abstract: Liquid Air Energy Storage systems represent a sustainable solution to store energy. Although a lot of interest is dedicated to large scale systems (up to 300 tons per day), a small-scale Liquid Air Energy Storage can be used as energy storage as part of a microgrid and/or an energy distribution network. However, when scaling down the size of the system, the round trip efficiency decreases due to the low performance of the liquefaction process. In this paper a preliminary study on the optimal configuration for a microgrid scale liquefaction cycle (10 tons per 12 h) for a Liquid Air Energy Storage application is proposed in order to minimize the specific consumption. The Linde, Claude and Kapitza cycles are modelled and compared by means of a parametric analysis carried out with the software Aspen HYSYS. The results show that the two stages compression Kapitza cycle operating at 40 bar represents an optimal solution in terms of performance and cycle configuration resulting in a specific consumption of about 700 kW h/t. The analysis also shows that the implementation of a pressurized phase separator leads to a reduction of the specific consumption as high as 21% (≈550 kW h/t).

  18. Energy storage

    International Nuclear Information System (INIS)

    2012-01-01

    After having outlined the importance of energy storage in the present context, this document outlines that it is an answer to economic, environmental and technological issues. It proposes a brief overview of the various techniques of energy storage: under the form of chemical energy (hydrocarbons, biomass, hydrogen production), thermal energy (sensitive or latent heat storage), mechanical energy (potential energy by hydraulic or compressed air storage, kinetic energy with flywheels), electrochemical energy (in batteries), electric energy (super-capacitors, superconductor magnetic energy storage). Perspectives are briefly evoked

  19. Transconjunctival orbital emphysema caused by compressed air injury: a case report.

    Science.gov (United States)

    Mathew, Sunu; Vasu, Usha; Francis, Febson; Nazareth, Colin

    2008-01-01

    Orbital emphysema following conjunctival tear in the absence of orbital wall fracture, caused by air under pressure is rare. Usually orbital emphysema is seen in facial trauma associated with damage to the adjacent paranasal sinuses or facial bones. To the best of our knowledge, there have been only eight reports of orbital emphysema following use of compressed air during industrial work. The air under pressure is pushed through the subconjunctival space into the subcutaneous and retrobulbar spaces. We present here a rare cause of orbital emphysema in a young man working with compressed air gun. Although the emphysema was severe, there were no orbital bone fracture and the visual recovery of the patient was complete without attendant complications.

  20. Compressed Air Working in Chennai During Metro Tunnel Construction: Occupational Health Problems.

    Science.gov (United States)

    Kulkarni, Ajit C

    2017-01-01

    Chennai metropolis has been growing rapidly. Need was felt of a metro rail system. Two corridors were planned. Corridor 1, of 23 km starting from Washermanpet to Airport. 14.3 km of this would be underground. Corridor 2, of 22 km starting from Chennai Central Railway station to St. Thomas Mount. 9.7 km of this would be underground. Occupational health centre's role involved selection of miners and assessing their fitness to work under compressed air. Planning and execution of compression and decompression, health monitoring and treatment of compression related illnesses. More than thirty five thousand man hours of work was carried out under compressed air pressure ranged from 1.2 to 1.9 bar absolute. There were only three cases of pain only ( Type I) decompression sickness which were treated with recompression. Vigilant medical supervision, experienced lock operators and reduced working hours under pressure because of inclement environmental conditions viz. high temperature and humidity, has helped achieve this low incident. Tunnelling activity will increase in India as more cities will soon opt for underground metro railway. Indian standard IS 4138 - 1977 " Safety code for working in compressed air" needs to be updated urgently keeping pace with modern working methods.

  1. Radiological air quality in a depleted uranium (DU) storage vault

    International Nuclear Information System (INIS)

    Robinson, T.; Cucchiara, A.L.

    1999-01-01

    The radiological air quality of two storage vaults, one with depleted uranium (DU) and one without, was evaluated and compared. The intent of the study was to determine if the presence of stored DU would significantly contribute to the gaseous/airborne radiation level compared to natural background. Both vaults are constructed out of concrete and are dimensionally similar. The vaults are located on the first floor of the same building. Neither vault has air supply or air exhaust. The doors to both vaults remained closed during the evaluation period, except for brief and infrequent access by the operational group. One vault contained 700 KG of depleted uranium, and the other vault contained documents inside of file cabinets. Radon detectors and giraffe air samplers were used to gather data on the quantity of gaseous/airborne radionuclides in both vaults. The results of this study indicated that there was no significant difference in the quantity of gaseous/airborne radionuclides in the two vaults. This paper gives a discussion of the effects of the stored DU on the air quality, and poses several theories supporting the results

  2. Hydrogen Station Compression, Storage, and Dispensing Technical Status and Costs: Systems Integration

    Energy Technology Data Exchange (ETDEWEB)

    Parks, G.; Boyd, R.; Cornish, J.; Remick, R.

    2014-05-01

    At the request of the U.S. Department of Energy Fuel Cell Technologies Office (FCTO), the National Renewable Energy Laboratory commissioned an independent review of hydrogen compression, storage, and dispensing (CSD) for pipeline delivery of hydrogen and forecourt hydrogen production. The panel was asked to address the (1) cost calculation methodology, (2) current cost/technical status, (3) feasibility of achieving the FCTO's 2020 CSD levelized cost targets, and to (4) suggest research areas that will help the FCTO reach its targets. As the panel neared the completion of these tasks, it was also asked to evaluate CSD costs for the delivery of hydrogen by high-pressure tube trailer. This report details these findings.

  3. Light-weight extension tubes for compressed-air garden sprayers

    Science.gov (United States)

    Thomas W. McConkey; Charles E. Swett

    1967-01-01

    To hand-spray taller trees safely and efficiently, 8-, 12-, and 16-foot extension tubes for compressed-air garden sprayers were designed and built. These light-weight tubes have been used successfully for spraying white pine leaders for weevil control on the Massabesic Experimental Forest in Maine. Bill of materials and assembly instructions are included.

  4. Safety in the use of compressed air versus oxygen for the ophthalmic patient.

    Science.gov (United States)

    Rodgers, Laura A; Kulwicki, Anahid

    2002-02-01

    Oxygen, routinely administered during surgery to avoid hypoxia, poses risks including increased likelihood of surgical room fires and predisposition to retinal phototoxicity in patients. Compressed air to supplement ventilation may be safer than oxygen. The purpose of this study was to determine whether hypoxia occurs more frequently when compressed air replaces supplemental oxygen during ophthalmic surgery. A convenience sample of 111 patients was randomly assigned to receive supplemental oxygen (group 1) or compressed air (group 2). Patients with serious cardiac or pulmonary disease were excluded. Blood oxygen levels were monitored during surgery by pulse oximetry. Oxygen was administered to all group 2 patients whose oxygen saturation fell to less than 90% or by more than 5% below baseline. No differences were observed between groups in age, ASA classification, type of surgery, or anesthetic drugs or doses. Minor, but statistically higher oxygen values were observed in group 1. The frequency with which oxygen saturation decreased below 90% or below 5% of baseline was similar in both groups. Supplemental oxygen is not required routinely in selected patients undergoing ophthalmic surgery. By using compressed air, the risk of operating room fires and retinal phototoxicity may be reduced.

  5. 76 FR 13661 - In the Matter of Certain Connecting Devices (“Quick Clamps”) for Use With Modular Compressed Air...

    Science.gov (United States)

    2011-03-14

    ... INTERNATIONAL TRADE COMMISSION [Investigation No. 337-TA-587] In the Matter of Certain Connecting Devices (``Quick Clamps'') for Use With Modular Compressed Air Conditioning Units, Including Filters... within the United States after importation of certain devices for modular compressed air conditioning...

  6. A review of pumped energy storage schemes

    International Nuclear Information System (INIS)

    Unsworth, G.N.

    1975-07-01

    The comparative advantages and costs of pumped water storage, steam accumulators, storage of boiler feedwater , and compressed air storage in caverns are described. Boiler feedwater storage in caverns and pumped water storage are most economical. All systems are costly enough to justify developing reactors with load following capabilities. (E.C.B.)

  7. Flat plate solar air heater with latent heat storage

    Science.gov (United States)

    Touati, B.; Kerroumi, N.; Virgone, J.

    2017-02-01

    Our work contains two parts, first is an experimental study of the solar air heater with a simple flow and forced convection, we can use thatlaste oneit in many engineering's sectors as solardrying, space heating in particular. The second part is a numerical study with ansys fluent 15 of the storage of part of this solar thermal energy produced,using latent heat by using phase change materials (PCM). In the experimental parts, we realize and tested our solar air heater in URER.MS ADRAR, locate in southwest Algeria. Where we measured the solarradiation, ambient temperature, air flow, thetemperature of the absorber, glasses and the outlet temperature of the solar air heater from the Sunrise to the sunset. In the second part, we added a PCM at outlet part of the solar air heater. This PCM store a part of the energy produced in the day to be used in peak period at evening by using the latent heat where the PCMs present a grateful storagesystem.A numerical study of the fusion or also named the charging of the PCM using ANSYS Fluent 15, this code use the method of enthalpies to solve the fusion and solidification formulations. Furthermore, to improve the conjugate heat transfer between the heat transfer fluid (Air heated in solar plate air heater) and the PCM, we simulate the effect of adding fins to our geometry. Also, four user define are write in C code to describe the thermophysicalpropriety of the PCM, and the inlet temperature of our geometry which is the temperature at the outflow of the solar heater.

  8. Spent fuel treatment to allow storage in air

    International Nuclear Information System (INIS)

    Williams, K.L.

    1988-01-01

    During Fiscal Year 1987 (FY-87), research began at the Idaho National Engineering Laboratory (INEL) to develop a treatment material and process to coat fuel rods in commercial spent fuel assemblies to allow the assemblies to be stored in hot (up to 380 0 C) air without oxidation of the fuel. This research was conducted under a research and development fund provided by the U.S. Department of Energy (DOE) and independently administered by EG and G Idaho, Inc., DOE's prime contractor at the INEL. The objectives of the research were to identify and evaluate possible treatment processes and materials, identify areas of uncertainty, and to recommend the most likely candidate to allow spent fuel dry storage in hot air. The results of the research are described: results were promising and several good candidates were identified, but further research is needed to examine the candidates to the point where comparison is possible

  9. Energy storage, compression, and switching in a theta-pinch fusion test reactor

    International Nuclear Information System (INIS)

    Thomassen, K.I.

    1976-01-01

    A new 488 MJ superconducting magnetic energy storage and transfer system is being proposed for a Scyllac Fusion Test Reactor. The 1280 module system uses vacuum interrupters to switch 26 kA storage currents in 0.7 ms through a capacitive transfer circuit at 60 kV to the compression coils in the machine. Many of the components of the system have been built and tested and a prototype section of the machine is planned. Prototype coils with 381 kJ at 26 kA currents will be built by industry using advanced superconducting wire. The wire uses a Cu and Cu--Ni matrix around filaments of Nb--Ti to minimize eddy current losses. These wires are presently used in a 10 kA braided conductor for 300 kJ pre-prototype coils, and can withstand field changes of approximately 10 7 gauss/sec without inducing normal transitions. Three such 300 kJ coils are being constructed in industry for the LASL program

  10. A compressive sensing based secure watermark detection and privacy preserving storage framework.

    Science.gov (United States)

    Qia Wang; Wenjun Zeng; Jun Tian

    2014-03-01

    Privacy is a critical issue when the data owners outsource data storage or processing to a third party computing service, such as the cloud. In this paper, we identify a cloud computing application scenario that requires simultaneously performing secure watermark detection and privacy preserving multimedia data storage. We then propose a compressive sensing (CS)-based framework using secure multiparty computation (MPC) protocols to address such a requirement. In our framework, the multimedia data and secret watermark pattern are presented to the cloud for secure watermark detection in a CS domain to protect the privacy. During CS transformation, the privacy of the CS matrix and the watermark pattern is protected by the MPC protocols under the semi-honest security model. We derive the expected watermark detection performance in the CS domain, given the target image, watermark pattern, and the size of the CS matrix (but without the CS matrix itself). The correctness of the derived performance has been validated by our experiments. Our theoretical analysis and experimental results show that secure watermark detection in the CS domain is feasible. Our framework can also be extended to other collaborative secure signal processing and data-mining applications in the cloud.

  11. Compressed air tunneling and caisson work decompression procedures: development, problems, and solutions.

    Science.gov (United States)

    Kindwall, E P

    1997-01-01

    Multinational experience over many years indicates that all current air decompression schedules for caisson and compressed air tunnel workers are inadequate. All of them, including the Occupational Safety and Health Administration tables, produce dysbaric osteonecrosis. The problem is compounded because decompression sickness (DCS) tends to be underreported. Permanent damage in the form of central nervous system or brain damage may occur in compressed air tunnel workers, as seen on magnetic resonance imaging, in addition to dysbaric osteonecrosis. Oxygen decompression seems to be the only viable method for safely decompressing tunnel workers. Oxygen decompression of tunnel workers has been successfully used in Germany, France, and Brazil. In Germany, only oxygen decompression of compressed air workers is permitted. In our experience, U.S. Navy tables 5 and 6 usually prove adequate to treat DCS in caisson workers despite extremely long exposure times, allowing patients to return to work following treatment for DCS. Tables based on empirical data and not on mathematical formulas seem to be reasonably safe. U.S. Navy Exceptional Exposure Air Decompression tables are compared with caisson tables from the United States and Great Britain.

  12. Improving the performance of a compression ignition engine by directing flow of inlet air

    Science.gov (United States)

    Kemper, Carlton

    1946-01-01

    The object of this report is to present the results of tests performed by the National Advisory Committee for Aeronautics to determine the effect on engine performance of directing the flow of the inlet air to a 5-inch by 7-inch cylinder, solid injection, compression ignition engine, After a few preliminary tests, comparative runs were made at a speed of 1500 r.p.m. with and without directed air flow. It was found that directing the flow of the inlet air toward the fuel injection valve gave steadier engine operation, and an appreciable increase in power, and decreased fuel consumption. The results indicate the possibility of improving the performance of a given type of combustion chamber without changing its shape and with no change in valve timing. They would also seem to prove that directional turbulence, set up before the inlet valve of a four-stroke cycle engine, continues in the engine cylinder throughout the compression stroke.

  13. Carbon Dioxide and Nitrogen Infused Compressed Air Foam for Depopulation of Caged Laying Hens

    Science.gov (United States)

    Gurung, Shailesh; White, Dima; Archer, Gregory; Styles, Darrel; Zhao, Dan; Farnell, Yuhua; Byrd, James; Farnell, Morgan

    2018-01-01

    Simple Summary Compressed air, detergent, and water make up compressed air foam. Our laboratory has previously reported that compressed air foam may be an effective method for mass depopulation of caged layer hens. Gases, such as carbon dioxide and nitrogen, have also been used for poultry euthanasia and depopulation. The objective of this study was to produce compressed air foam infused with carbon dioxide or nitrogen to compare its efficacy against foam with air and gas inhalation methods (carbon dioxide or nitrogen) for depopulation of caged laying hens. The study showed that a carbon dioxide-air mixture or 100% nitrogen can replace air to make compressed air foam. However, the foam with carbon dioxide had poor foam quality compared to the foam with air or nitrogen. The physiological stress response of hens subjected to foam treatments with and without gas infusion did not differ significantly. Hens exposed to foam with nitrogen died earlier as compared to methods such as foam with air and carbon dioxide. The authors conclude that infusion of nitrogen into compressed air foam results in better foam quality and shortened time to death as compared to the addition of carbon dioxide. Abstract Depopulation of infected poultry flocks is a key strategy to control and contain reportable diseases. Water-based foam, carbon dioxide inhalation, and ventilation shutdown are depopulation methods available to the poultry industry. Unfortunately, these methods have limited usage in caged layer hen operations. Personnel safety and welfare of birds are equally important factors to consider during emergency depopulation procedures. We have previously reported that compressed air foam (CAF) is an alternative method for depopulation of caged layer hens. We hypothesized that infusion of gases, such as carbon dioxide (CO2) and nitrogen (N2), into the CAF would reduce physiological stress and shorten time to cessation of movement. The study had six treatments, namely a negative control

  14. Compressed-air and backup nitrogen systems in nuclear power plants

    International Nuclear Information System (INIS)

    Hagen, E.W.

    1982-07-01

    This report reviews and evaluates the performance of the compressed-air and pressurized-nitrogen gas systems in commercial nuclear power units. The information was collected from readily available operating experiences, licensee event reports, system designs in safety analysis reports, and regulatory documents. The results are collated and analyzed for significance and impact on power plant safety performance. Under certain circumstances, the fail-safe philosophy for a piece of equipment or subsystem of the compressed-air systems initiated a series of actions culminating in reactor transient or unit scram. However, based on this study of prevailing operating experiences, reclassifying the compressed-gas systems to a higher safety level will neither prevent (nor mitigate) the reoccurrences of such happenings nor alleviate nuclear power plant problems caused by inadequate maintenance, operating procedures, and/or practices. Conversely, because most of the problems were derived from the sources listed previously, upgrading of both maintenance and operating procedures will not only result in substantial improvement in the performance and availability of the compressed-air (and backup nitrogen) systems but in improved overall plant performance

  15. CFD simulations of compressed air two stage rotary Wankel expander – Parametric analysis

    International Nuclear Information System (INIS)

    Sadiq, Ghada A.; Tozer, Gavin; Al-Dadah, Raya; Mahmoud, Saad

    2017-01-01

    Highlights: • CFD ANSYS-Fluent 3D simulation of Wankel expander is developed. • Single and two-stage expander’s performance is compared. • Inlet and outlet ports shape and configurations are investigated. • Isentropic efficiency of two stage Wankel expander of 91% is achieved. - Abstract: A small scale volumetric Wankel expander is a powerful device for small-scale power generation in compressed air energy storage (CAES) systems and Organic Rankine cycles powered by different heat sources such as, biomass, low temperature geothermal, solar and waste heat leading to significant reduction in CO_2 emissions. Wankel expanders outperform other types of expander due to their ability to produce two power pulses per revolution per chamber additional to higher compactness, lower noise and vibration and lower cost. In this paper, a computational fluid dynamics (CFD) model was developed using ANSYS 16.2 to simulate the flow dynamics for a single and two stage Wankel expanders and to investigate the effect of port configurations, including size and spacing, on the expander’s power output and isentropic efficiency. Also, single-stage and two-stage expanders were analysed with different operating conditions. Single-stage 3D CFD results were compared to published work showing close agreement. The CFD modelling was used to investigate the performance of the rotary device using air as an ideal gas with various port diameters ranging from 15 mm to 50 mm; port spacing varying from 28 mm to 66 mm; different Wankel expander sizes (r = 48, e = 6.6, b = 32) mm and (r = 58, e = 8, b = 40) mm both as single-stage and as two-stage expanders with different configurations and various operating conditions. Results showed that the best Wankel expander design for a single-stage was (r = 48, e = 6.6, b = 32) mm, with the port diameters 20 mm and port spacing equal to 50 mm. Moreover, combining two Wankel expanders horizontally, with a larger one at front, produced 8.52 kW compared

  16. Compressed-air work is entering the field of high pressures.

    Science.gov (United States)

    Le Péchon, J Cl; Gourdon, G

    2010-01-01

    Since 1850, compressed-air work has been used to prevent shafts or tunnels under construction from flooding. Until the 1980s, workers were digging in compressed-air environments. Since the introduction of tunnel boring machines (TBMs), very little digging under pressure is needed. However, the wearing out of cutter-head tools requires inspection and repair. Compressed-air workers enter the pressurized working chamber only occasionally to perform such repairs. Pressures between 3.5 and 4.5 bar, that stand outside a reasonable range for air breathing, were reached by 2002. Offshore deep diving technology had to be adapted to TBM work. Several sites have used mixed gases: in Japan for deep shaft sinking (4.8 bar), in The Netherlands at Western Scheldt Tunnels (6.9 bar), in Russia for St. Petersburg Metro (5.8 bar) and in the United States at Seattle (5.8 bar). Several tunnel projects are in progress that may involve higher pressures: Hallandsås (Sweden) interventions in heliox saturation up to 13 bar, and Lake Mead (U.S.) interventions to about 12 bar (2010). Research on TBMs and grouting technologies tries to reduce the requirements for hyperbaric works. Adapted international rules, expertise and services for saturation work, shuttles and trained personnel matching industrial requirements are the challenges.

  17. Experimental investigations on performance of liquid desiccant-vapor compression hybrid air conditioner

    International Nuclear Information System (INIS)

    Mohan, B. Shaji; Tiwari, Shaligram; Maiya, M.P.

    2015-01-01

    A coupled desiccant column is integrated with a conventional room air conditioner (AC) to enhance dehumidification of the room air. One desiccant column (absorber) is placed after the evaporator the other (regenerator) after the condenser of the AC unit. Such a novel liquid desiccant vapour compression hybrid air conditioning system has been fabricated and tested in a balanced ambient room type calorimeter for very low flow rates of liquid desiccant (lithium bromide solution). The moisture from the cold supply air is transferred to the hot condenser air by the desiccant flowing in the loop, thereby complimenting the dehumidification of the room air at the evaporator. The supply air is also sensibly heated during the dehumidification process by liquid desiccant in the absorber, which together enables the hybrid system to maintain low humidity in the room. Whereas the liquid desiccant is regenerated by the condenser waste heat, the entire cooling is derived only by the AC unit. The experimental results show that an increase of room temperature reduces both dehumidification of process air and regeneration of liquid desiccant, whereas an increase of room specific humidity enhances both these for the flow rate of the liquid desiccant in the range of 0.2–1.6% of the air flow rate through the absorber. - Highlights: • A liquid desiccant vapor compression hybrid system is fabricated and tested. • The liquid desiccant reduces latent load but equally increases sensible load. • Hybrid system performance is studied for varying room temperature and humidity. • Higher room temperature lowers air dehumidification and desiccant regeneration. • Increase of room specific humidity enhances dehumidification and also regeneration

  18. Study, Evaluation and Implementation of Improvement in a Compressed Air Plant

    Directory of Open Access Journals (Sweden)

    Carlos Roberto Altafini

    2013-12-01

    Full Text Available This paper presents a study of a compressed air generation system in a bus manufacturer, being evaluated the operation of the compressors to identify the electric energy consumption. A maintenance plan is elaborated to correct the air system leaks and also proposes the reuse of thermal energy generated by the compressors. Initially, as for the purpose of this paper, a revision of fundamentals related to thermodynamics transformation is presented. Afterwards, some important electric energy concepts will lead to the understanding of the energy consumption of the compressors. Then, an overview about compressed air generation systems will be showed with the goal of understanding techniques of energetic efficiency. The tools used in this study for collecting data were the software of a compressor manufacturer with pressure transducers and an energy analyzer. The basic concepts and their uses will be shown along this paper. The proposal of electric energy consumption reduction was achieved with the installation of compressor operation managers and yields a reduction about 60,600 kWh per month, which provided a monthly saving of R$19,400.00, validating the collected data. For heat recovery from the cooling air compressors, externally finned coils were sized to heat water up to 55◦C and used in a process of heating rubber gaskets. For air leakage reduction, a working methodology to perform the corrective and preventive maintenance has been prepared, and a control system in the form of internal audit. The obtained air leakage reduction was about 50%.

  19. A DTM MULTI-RESOLUTION COMPRESSED MODEL FOR EFFICIENT DATA STORAGE AND NETWORK TRANSFER

    Directory of Open Access Journals (Sweden)

    L. Biagi

    2012-08-01

    Full Text Available In recent years the technological evolution of terrestrial, aerial and satellite surveying, has considerably increased the measurement accuracy and, consequently, the quality of the derived information. At the same time, the smaller and smaller limitations on data storage devices, in terms of capacity and cost, has allowed the storage and the elaboration of a bigger number of instrumental observations. A significant example is the terrain height surveyed by LIDAR (LIght Detection And Ranging technology where several height measurements for each square meter of land can be obtained. The availability of such a large quantity of observations is an essential requisite for an in-depth knowledge of the phenomena under study. But, at the same time, the most common Geographical Information Systems (GISs show latency in visualizing and analyzing these kind of data. This problem becomes more evident in case of Internet GIS. These systems are based on the very frequent flow of geographical information over the internet and, for this reason, the band-width of the network and the size of the data to be transmitted are two fundamental factors to be considered in order to guarantee the actual usability of these technologies. In this paper we focus our attention on digital terrain models (DTM's and we briefly analyse the problems about the definition of the minimal necessary information to store and transmit DTM's over network, with a fixed tolerance, starting from a huge number of observations. Then we propose an innovative compression approach for sparse observations by means of multi-resolution spline functions approximation. The method is able to provide metrical accuracy at least comparable to that provided by the most common deterministic interpolation algorithms (inverse distance weighting, local polynomial, radial basis functions. At the same time it dramatically reduces the number of information required for storing or for transmitting and rebuilding a

  20. Open air-vapor compression refrigeration system for air conditioning and hot water cooled by cool water

    International Nuclear Information System (INIS)

    Hou Shaobo; Li Huacong; Zhang Hefei

    2007-01-01

    This paper presents an open air-vapor compression refrigeration system for air conditioning and hot water cooled by cool water and proves its feasibility through performance simulation. Pinch technology is used in analysis of heat exchange in the surface heat exchanger, and the temperature difference at the pinch point is selected as 6 o C. Its refrigeration depends mainly on both air and vapor, more efficient than a conventional air cycle, and the use of turbo-machinery makes this possible. This system could use the cool in the cool water, which could not be used to cool air directly. Also, the heat rejected from this system could be used to heat cool water to 33-40 o C. The sensitivity analysis of COP to η c and η t and the simulated results T 4 , T 7 , T 8 , q 1 , q 2 and W m of the cycle are given. The simulations show that the COP of this system depends mainly on T 7 , η c and η t and varies with T 3 or T wet and that this cycle is feasible in some regions, although the COP is sensitive to the efficiencies of the axial compressor and turbine. The optimum pressure ratio in this system could be lower, and this results in a fewer number of stages of the axial compressor. Adjusting the rotation speed of the axial compressor can easily control the pressure ratio, mass flow rate and the refrigerating capacity. The adoption of this cycle will make the air conditioned room more comfortable and reduce the initial investment cost because of the obtained very low temperature air. Humid air is a perfect working fluid for central air conditioning and no cost to the user. The system is more efficient because of using cool water to cool the air before the turbine. In addition, pinch technology is a good method to analyze the wet air heat exchange with water

  1. [Pediatric orbital emphysema caused by a compressed-air pistol shot: a case report].

    Science.gov (United States)

    Navarro-Mingorance, A; Reyes-Dominguez, S B; León-León, M C

    2014-09-01

    We report the case of a 2 year-old child with orbital emphysema secondary to a compressed-air gun shot in the malar region, with no evidence of orbital wall fracture. Conservative treatment was applied, and no complications were observed. Orbital emphysema in the absence of an orbital wall fracture is a rare situation. Orbital emphysema is usually seen in facial trauma associated with damage to the adjacent paranasal sinuses or facial bones. To our knowledge there have been very few reports of orbital emphysema caused by a compressed-air injury. Copyright © 2012 Sociedad Española de Oftalmología. Published by Elsevier Espana. All rights reserved.

  2. Colorectal injury by compressed air--a report of 2 cases.

    Science.gov (United States)

    Suh, H. H.; Kim, Y. J.; Kim, S. K.

    1996-01-01

    We report two colorectal trauma patients whose rectosigmoid region was ruptured due to a jet of compressed air directed to their anus while they were playing practical jokes with their colleagues in their place of work. It was difficult to diagnose in one patient due to vague symptoms and signs and due to being stunned by a stroke of the compressed air. Both patients suffered from abdominal pain and distension, tension pneumoperitoneum and mild respiratory alkalosis. One patient was treated with primary two layer closure, and the other with primary two layer closure and sigmoid loop colostomy. Anorectal manometry and transanal ultrasonography checked 4 weeks after surgery, revealed normal anorectal function and anatomy. The postoperative courses were favorable without any wound infection or intraabdominal sepsis. PMID:8835767

  3. Pressure Regulators as Valves for Saving Compressed Air and their Influence on System Dynamics

    Directory of Open Access Journals (Sweden)

    Dvořák Lukáš

    2015-01-01

    Full Text Available Pressure regulators in the field of pneumatic mechanisms can be used as valves for saving compressed air. For example it can be used to reduce the pressure when the piston rod is retracting unloaded and thus it is possible to save some energy. However the problem is that saving valve can significantly affect the dynamics of the pneumatic system. The lower pressure in the piston rod chamber causes extension of time for retraction of the piston rod. This article compare the air consumption experimentally determined and calculated, measured curves of pressure in cylinder chambers and piston speed when saving valve is set up differently.

  4. Pressure Regulators as Valves for Saving Compressed Air and their Influence on System Dynamics

    Science.gov (United States)

    Dvořák, Lukáš; Fojtášek, Kamil

    2015-05-01

    Pressure regulators in the field of pneumatic mechanisms can be used as valves for saving compressed air. For example it can be used to reduce the pressure when the piston rod is retracting unloaded and thus it is possible to save some energy. However the problem is that saving valve can significantly affect the dynamics of the pneumatic system. The lower pressure in the piston rod chamber causes extension of time for retraction of the piston rod. This article compare the air consumption experimentally determined and calculated, measured curves of pressure in cylinder chambers and piston speed when saving valve is set up differently.

  5. Increasing the Air Charge and Scavenging the Clearance Volume of a Compression-Ignition Engine

    Science.gov (United States)

    Spanogle, J A; Hicks, C W; Foster, H H

    1934-01-01

    The object of the investigation presented in this report was to determine the effects of increasing the air charge and scavenging the clearance volume of a 4-stroke-cycle compression-ignition engine having a vertical-disk form combustion chamber. Boosting the inlet-air pressure with normal valve timing increased the indicated engine power in proportion to the additional air inducted and resulted in smoother engine operation with less combustion shock. Scavenging the clearance volume by using a valve overlap of 145 degrees and an inlet-air boost pressure of approximately 2 1/2 inches of mercury produced a net increase in performance for clear exhaust operation of 33 percent over that obtained with normal valve timing and the same boost pressure. The improved combustion characteristics result in lower specific fuel consumption, and a clearer exhaust.

  6. Bilateral orbital emphysema and pneumocephalus as a result of accidental compressed air exposure.

    Science.gov (United States)

    Yuksel, Murvet; Yuksel, K Zafer; Ozdemir, Gokhan; Ugur, Tuncay

    2007-01-01

    Orbital emphysema is a rare condition in the absence of trauma or sinus disease. A 22-year-old man suffering from left orbital trauma due to sudden exposure to compressed air tube was admitted with severe pain in the left eye, swelling, and mild periorbital ecchymosis. Physical examination revealed a large conjunctival laceration in the left orbit. Multislice computed tomographic scanning of the head and orbits showed extensive radiolucencies consistent with the air in both orbits, more prominent in the left. There was also subcutaneous air in the left periorbital soft tissue extending through fronto-temporal and zygomatic areas. Air was also demonstrated adjacent to the left optic canal and within the subarachnoid space intracranially. There was no evidence of any orbital, paranasal sinus, or cranial fracture. Visual acuity was minimally decreased bilaterally. The conjunctiva was sutured under local anesthesia. After 3 weeks of follow-up, the patient completely recovered without visual loss. Bilateral orbital emphysema with pneumocephalus can occur from a high-pressure compressed air injury after unilateral conjunctival trauma without any evidence of fracture.

  7. Evaluation of Two Compressed Air Foam Systems for Culling Caged Layer Hens

    Science.gov (United States)

    Weiher, Jaclyn A.; Alphin, Robert L.; Hougentogler, Daniel P.

    2018-01-01

    Simple Summary Control of avian influenza and similar diseases in commercial poultry operations is challenging; the six major steps are surveillance, biosecurity, quarantine, depopulation, disposal, and cleaning and disinfection. Depopulation is used to cull animals that are terminally ill and to reduce the number of animals that can spread an untreatable disease. Water-based foam depopulation was used effectively during the 2014–2015 highly pathogenic avian influenza outbreak in the United States. Water-based foam, however, cannot be used effectively in caged poultry operations. Compressed air foam systems were initially developed for structural fire-fighting and, with modifications, can provide the conditions required to effectively penetrate a poultry cage and provide sufficient residence time for depopulation. In this experiment, compressed air foam was used to depopulate caged layer hens. Compressed air foam resulted in faster unconsciousness than carbon dioxide gassing. The experiment demonstrated that compressed air foam systems have promise for depopulating birds raised in cages. Abstract Outbreaks of avian influenza (AI) and other highly contagious poultry diseases continue to be a concern for those involved in the poultry industry. In the situation of an outbreak, emergency depopulation of the birds involved is necessary. In this project, two compressed air foam systems (CAFS) were evaluated for mass emergency depopulation of layer hens in a manure belt equipped cage system. In both experiments, a randomized block design was used with multiple commercial layer hens treated with one of three randomly selected depopulation methods: CAFS, CAFS with CO2 gas, and CO2 gas. In Experiment 1, a Rowe manufactured CAFS was used, a selection of birds were instrumented, and the time to unconsciousness, brain death, altered terminal cardiac activity and motion cessation were recorded. CAFS with and without CO2 was faster to unconsciousness, however, the other

  8. A new class of solid oxide metal-air redox batteries for advanced stationary energy storage

    Science.gov (United States)

    Zhao, Xuan

    Cost-effective and large-scale energy storage technologies are a key enabler of grid modernization. Among energy storage technologies currently being researched, developed and deployed, rechargeable batteries are unique and important that can offer a myriad of advantages over the conventional large scale siting- and geography- constrained pumped-hydro and compressed-air energy storage systems. However, current rechargeable batteries still need many breakthroughs in material optimization and system design to become commercially viable for stationary energy storage. This PhD research project investigates the energy storage characteristics of a new class of rechargeable solid oxide metal-air redox batteries (SOMARBs) that combines a regenerative solid oxide fuel cell (RSOFC) and hydrogen chemical-looping component. The RSOFC serves as the "electrical functioning unit", alternating between the fuel cell and electrolysis mode to realize discharge and charge cycles, respectively, while the hydrogen chemical-looping component functions as an energy storage unit (ESU), performing electrical-chemical energy conversion in situ via a H2/H2O-mediated metal/metal oxide redox reaction. One of the distinctive features of the new battery from conventional storage batteries is the ESU that is physically separated from the electrodes of RSOFC, allowing it to freely expand and contract without impacting the mechanical integrity of the entire battery structure. This feature also allows an easy switch in the chemistry of this battery. The materials selection for ESU is critical to energy capacity, round-trip efficiency and cost effectiveness of the new battery. Me-MeOx redox couples with favorable thermodynamics and kinetics are highly preferable. The preliminary theoretical analysis suggests that Fe-based redox couples can be a promising candidate for operating at both high and low temperatures. Therefore, the Fe-based redox-couple systems have been selected as the baseline for this

  9. Time-resolved imaging of a compressible air disc under a drop impacting on a solid surface

    KAUST Repository

    Li, Erqiang

    2015-09-07

    When a drop impacts on a solid surface, its rapid deceleration is cushioned by a thin layer of air, which leads to the entrapment of a bubble under its centre. For large impact velocities the lubrication pressure in this air layer becomes large enough to compress the air. Herein we use high-speed interferometry, with 200 ns time-resolution, to directly observe the thickness evolution of the air layer during the entire bubble entrapment process. The initial disc radius and thickness shows excellent agreement with available theoretical models, based on adiabatic compression. For the largest impact velocities the air is compressed by as much as a factor of 14. Immediately following the contact, the air disc shows rapid vertical expansion. The radial speed of the surface minima just before contact, can reach 50 times the impact velocity of the drop.

  10. Study on the influence of supplying compressed air channels and evicting channels on pneumatical oscillation systems for vibromooshing

    Science.gov (United States)

    Glăvan, D. O.; Radu, I.; Babanatsas, T.; Babanatis Merce, R. M.; Kiss, I.; Gaspar, M. C.

    2018-01-01

    The paper presents a pneumatic system with two oscillating masses. The system is composed of a cylinder (framework) with mass m1, which has a piston with mass m2 inside. The cylinder (framework system) has one supplying channel for compressed air and one evicting channel for each work chamber (left and right of the piston). Functionality of the piston position comparatively with the cylinder (framework) is possible through the supplying or evicting of compressed air. The variable force that keeps the movement depends on variation of the pressure that is changing depending on the piston position according to the cylinder (framework) and to the section form that is supplying and evicting channels with compressed air. The paper presents the physical model/pattern, the mathematical model/pattern (differential equations) and numerical solution of the differential equations in hypothesis with the section form of supplying and evicting channels with compressed air is rectangular (variation linear) or circular (variation nonlinear).

  11. Optimization of the Starting by compressed air techniques; Optimizacion del Arranque en el sutiraje mediante tecnicas de aire comprimido

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-07-01

    High-pressure compressed air shots have been begun to use for coal stop caving in horizontal sublevel caving workings, as alternative to explosives, since they do not condition the winning cycles and they produce a smaller deterioration in the vein walls. In spite of those advantages, different parameters influence on shot result is not known. For this reason, a research project has been carried out in order to improve the high-pressure compressed air technique to extend the system implementation and to reduce the winning costs in the sublevel caving workings. The research works have consisted of a numerical model development and reduced scale and real scale tests. The model describes fragile material fragmentation under dynamical loadings and it has been implemented in a code. The tests allow to study the different parameter influence and to validate the numerical model. The main research results are, on the one hand, a numerical model that allows to define the best shot plan for user's working conditions and, on the other hand, the great influence of the air volume on the disruptive strength has been proven. (Author)

  12. A concept of an electricity storage system with 50 MWh storage capacity

    Directory of Open Access Journals (Sweden)

    Józef Paska

    2012-06-01

    Full Text Available Electricity storage devices can be divided into indirect storage technology devices (involving electricity conversion into another form of energy, and direct storage (in an electric or magnetic fi eld. Electricity storage technologies include: pumped-storage power plants, BES Battery Energy Storage, CAES Compressed Air Energy Storage, Supercapacitors, FES Flywheel Energy Storage, SMES Superconducting Magnetic Energy Storage, FC Fuel Cells reverse or operated in systems with electrolysers and hydrogen storage. These technologies have diff erent technical characteristics and economic parameters that determine their usability. This paper presents two concepts of an electricity storage tank with a storage capacity of at least 50 MWh, using the BES battery energy storage and CAES compressed air energy storage technologies.

  13. Accelerated Air-coupled Ultrasound Imaging of Wood Using Compressed Sensing

    Directory of Open Access Journals (Sweden)

    Yiming Fang

    2015-12-01

    Full Text Available Air-coupled ultrasound has shown excellent sensitivity and specificity for the nondestructive imaging of wood-based material. However, it is time-consuming, due to the high scanning density limited by the Nyquist law. This study investigated the feasibility of applying compressed sensing techniques to air-coupled ultrasound imaging, aiming to reduce the number of scanning lines and then accelerate the imaging. Firstly, an undersampled scanning strategy specified by a random binary matrix was proposed to address the limitation of the compressed sensing framework. The undersampled scanning can be easily implemented, while only minor modification was required for the existing imaging system. Then, discrete cosine transform was selected experimentally as the representation basis. Finally, orthogonal matching pursuit algorithm was utilized to reconstruct the wood images. Experiments on three real air-coupled ultrasound images indicated the potential of the present method to accelerate air-coupled ultrasound imaging of wood. The same quality of ACU images can be obtained with scanning time cut in half.

  14. Parametric analysis of a combined dew point evaporative-vapour compression based air conditioning system

    Directory of Open Access Journals (Sweden)

    Shailendra Singh Chauhan

    2016-09-01

    Full Text Available A dew point evaporative-vapour compression based combined air conditioning system for providing good human comfort conditions at a low cost has been proposed in this paper. The proposed system has been parametrically analysed for a wide range of ambient temperatures and specific humidity under some reasonable assumptions. The proposed system has also been compared from the conventional vapour compression air conditioner on the basis of cooling load on the cooling coil working on 100% fresh air assumption. The saving of cooling load on the coil was found to be maximum with a value of 60.93% at 46 °C and 6 g/kg specific humidity, while it was negative for very high humidity of ambient air, which indicates that proposed system is applicable for dry and moderate humid conditions but not for very humid conditions. The system is working well with an average net monthly power saving of 192.31 kW h for hot and dry conditions and 124.38 kW h for hot and moderate humid conditions. Therefore it could be a better alternative for dry and moderate humid climate with a payback period of 7.2 years.

  15. Commissioning and operating experience of compressed air system of a reprocessing plant (Paper No. 5.10)

    International Nuclear Information System (INIS)

    Nair, M.K.T.; Bajpai, D.D.; Mishra, A.K.; Kulkarni, H.B.; Raje, R.V.; Rajeshwar, S.

    1992-01-01

    Compressed air system is one of the most important utility systems, required in the continued operation of a radiochemical plant. Moisture and oil free compressed air is used in large scale for process control and process operations in reprocessing plants. Commissioning and operating experience of this system is described in detail, to indicate the importance of the system in the overall design and operation of such chemical plant. (author). 1 tab

  16. Gas turbine engine adapted for use in combination with an apparatus for separating a portion of oxygen from compressed air

    Science.gov (United States)

    Bland, Robert J [Oviedo, FL; Horazak, Dennis A [Orlando, FL

    2012-03-06

    A gas turbine engine is provided comprising an outer shell, a compressor assembly, at least one combustor assembly, a turbine assembly and duct structure. The outer shell includes a compressor section, a combustor section, an intermediate section and a turbine section. The intermediate section includes at least one first opening and at least one second opening. The compressor assembly is located in the compressor section to define with the compressor section a compressor apparatus to compress air. The at least one combustor assembly is coupled to the combustor section to define with the combustor section a combustor apparatus. The turbine assembly is located in the turbine section to define with the turbine section a turbine apparatus. The duct structure is coupled to the intermediate section to receive at least a portion of the compressed air from the compressor apparatus through the at least one first opening in the intermediate section, pass the compressed air to an apparatus for separating a portion of oxygen from the compressed air to produced vitiated compressed air and return the vitiated compressed air to the intermediate section via the at least one second opening in the intermediate section.

  17. The effect of compressed air massage on skin blood flow and temperature.

    Science.gov (United States)

    Mars, Maurice; Maharaj, Sunil S; Tufts, Mark

    2005-01-01

    Compressed air massage is a new treatment modality that uses air under pressure to massage skin and muscle. It is claimed to improve skin blood flow but this has not been verified. Several pilot studies were undertaken to determine the effects of compressed air massage on skin blood flow and temperature. Skin blood flow (SBF), measured using laser Doppler fluxmetry and skin temperature was recorded under several different situations: (i) treatment, at 1 Bar pressure using a single-hole (5-mm) applicator head, for 1 min at each of several sites on the right and left lower legs, with SBF measured on the dorsum of the left foot; (ii) at the same treatment pressure, SBF was measured over the left tibialis anterior when treatment was performed at different distances from the probe; (iii) SBF and skin temperature of the lower leg were measured with treatment at 0 or 1 Bar for 45 min, using two different applicator heads; (iv) SBF was measured on the dorsum of the foot of 10 subjects with treatment for 1 min at 0, 0.5, 1, 1.5 and 2 Bar using three different applicator heads. (i) SBF of the left foot was not altered by treatment of the right leg or chest, but was significantly increased during treatment of the left sole and first web, p Compressed air massage causes an immediate increase in SBF, and an immediate fall in SBF when treatment is stopped. The effect appears to be locally and not centrally mediated and is related to the pressure used. Treatment cools the skin for at least 15 min after a 45-min treatment.

  18. Comparative study of air conditioning systems with vapor compression chillers using the concept of green buildings

    Directory of Open Access Journals (Sweden)

    Gutenberg da Silva Pereira

    2015-10-01

    Full Text Available This paper sets out to compare two different cooling systems that use vapor compression chillers for air conditioning environments. It was proposed to compare different operations in isolated and combined action operations. These operations are evaluated in the concepts of green buildings. A mathematical model was developed based on the principles of mass and energy conservation and complemented by various functions so as to determine the thermophysical properties and efficiencies of the compressors. The equations of the model were solved by the EES (Engineering Equation Solver program. The model evaluates the influence of the main HVAC operating parameters of the chilled water system when operating under three different configurations. The results showed that the system with a differentiated compression presents a COP equal to that of the system with screw chillers in the range  0-300 RTs, and a COP hat is on average 9% higher in the range 400-800 RTs.

  19. A Scramjet Compression System for Hypersonic Air Transportation Vehicle Combined Cycle Engines

    Directory of Open Access Journals (Sweden)

    Devendra Sen

    2018-06-01

    Full Text Available This paper proposes a compression system for a scramjet, to be used as part of a combined cycle engine on a hypersonic transport vehicle that can achieve sustained flight at 8 Mach 8. Initially research into scramjet compression system and shock wave interaction was conducted to establish the foundation of the scramjet inlet and isolator sections. A Computational Fluid Dynamics (CFD campaign was conducted, where the shock structure and flow characteristics was analysed between Mach 4.5–8. The compression system of a scramjet is of crucial importance in providing air at suitable Mach number, pressure and temperature to the combustion chamber. The use of turbojet engines in over-under configuration with the scramjet was investigated as well as the study of a combined cycle scramjet-ramjet configuration. It was identified that locating the scramjet in the centre with a rotated ramjet on either side, where its ramps make up the scramjet wall was the most optimal configuration, as it mitigated the effect of the oblique shocks propagating from the scramjet walls into the adjacent ramjet. Furthermore, this meant that the forebody of the vehicle could solely be used as the compression surface by the scramjet. In this paper, the sizing of the scramjet combustion chamber and nozzle were modified to match the flow properties of the oncoming flow with the purpose of producing the most optimum scramjet configuration for the cruise speed of Mach 8. CFD simulations showed that the scramjet inlet did not provide the levels of compression and stagnation pressure recovery initially required. However, it was found that the scramjet provided significantly more thrust than the drag of the aircraft at sustained Mach 8 flight, due to its utilisation of a very aerodynamic vehicle design.

  20. Class B Fire-Extinguishing Performance Evaluation of a Compressed Air Foam System at Different Air-to-Aqueous Foam Solution Mixing Ratios

    Directory of Open Access Journals (Sweden)

    Dong-Ho Rie

    2016-06-01

    Full Text Available The purpose of this research is to evaluate the fire-extinguishing performance of a compressed air foam system at different mixing ratios of pressurized air. In this system, compressed air is injected into an aqueous solution of foam and then discharged. The experimental device uses an exclusive fire-extinguishing technology with compressed air foam that is produced based on the Canada National Laboratory and UL (Underwriters Laboratories 162 standards, with a 20-unit oil fire model (Class B applied as the fire extinguisher. Compressed air is injected through the air mixture, and results with different air-to-aqueous solution foam ratios of 1:4, 1:7, and 1:10 are studied. In addition, comparison experiments between synthetic surfactant foam and a foam type which forms an aqueous film are carried out at an air-to-aqueous solution foam ratio of 1:4. From the experimental results, at identical discharging flows, it was found that the fire-extinguishing effect of the aqueous film-forming foam is greatest at an air-to-aqueous solution foam ratio of 1:7 and weakest at 1:10. Moreover, the fire-extinguishing effect of the aqueous film-forming foam in the comparison experiments between the aqueous film-forming foam and the synthetic surfactant foam is greatest.

  1. Nitric oxide contamination of hospital compressed air improves gas exchange in patients with acute lung injury.

    Science.gov (United States)

    Tan, P Seow Koon; Genc, F; Delgado, E; Kellum, J A; Pinsky, M R

    2002-08-01

    We tested the hypothesis that NO contamination of hospital compressed air also improves PaO(2) in patients with acute lung injury (ALI) and following lung transplant (LTx). Prospective clinical study. Cardiothoracic intensive care unit. Subjects following cardiac surgery (CABG, n=7); with ALI (n=7), and following LTx (n=5). Four sequential 15-min steps at a constant FiO(2) were used: hospital compressed air-O(2) (H1), N(2)-O(2) (A1), repeat compressed air-O(2) (H2), and repeat N(2)-O(2) (A2). NO levels were measured from the endotracheal tube. Cardiorespiratory values included PaO(2) were measured at the end of each step. FiO(2) was 0.46+/-0.05, 0.53+/-0.15, and 0.47+/-0.06 (mean+/-SD) for three groups, respectively. Inhaled NO levels during H1 varied among subjects (30-550 ppb, 27-300 ppb, and 5-220 ppb, respectively). Exhaled NO levels were not detected in 4/7 of CABG (0-300 ppb), 3/6 of ALI (0-140 ppb), and 3/5 of LTx (0-59 ppb) patients during H1, whereas during A1 all but one patient in ALI and three CABG patients had measurable exhaled NO levels (P<0.05). Small but significant decreases in PaO(2) occurred for all groups from H1 to A1 and H2 to A2 (132-99 Torr and 128-120 Torr, P <0.01, respectively). There was no correlation between inhaled NO during H1 and exhaled NO during A1 or the change in PaO(2) from H1 to A1. Low-level NO contamination improves PaO(2) in patients with ALI and following LTx.

  2. Integrated LTCC pressure/flow/temperature multisensor for compressed air diagnostics.

    Science.gov (United States)

    Fournier, Yannick; Maeder, Thomas; Boutinard-Rouelle, Grégoire; Barras, Aurélie; Craquelin, Nicolas; Ryser, Peter

    2010-01-01

    We present a multisensor designed for industrial compressed air diagnostics and combining the measurement of pressure, flow, and temperature, integrated with the corresponding signal conditioning electronics in a single low-temperature co-fired ceramic (LTCC) package. The developed sensor may be soldered onto an integrated electro-fluidic platform by using standard surface mount device (SMD) technology, e.g., as a standard electronic component would be on a printed circuit board, obviating the need for both wires and tubes and thus paving the road towards low-cost integrated electro-fluidic systems. Several performance aspects of this device are presented and discussed, together with electronics design issues.

  3. Integrated LTCC Pressure/Flow/Temperature Multisensor for Compressed Air Diagnostics†

    Science.gov (United States)

    Fournier, Yannick; Maeder, Thomas; Boutinard-Rouelle, Grégoire; Barras, Aurélie; Craquelin, Nicolas; Ryser, Peter

    2010-01-01

    We present a multisensor designed for industrial compressed air diagnostics and combining the measurement of pressure, flow, and temperature, integrated with the corresponding signal conditioning electronics in a single low-temperature co-fired ceramic (LTCC) package. The developed sensor may be soldered onto an integrated electro-fluidic platform by using standard surface mount device (SMD) technology, e.g., as a standard electronic component would be on a printed circuit board, obviating the need for both wires and tubes and thus paving the road towards low-cost integrated electro-fluidic systems. Several performance aspects of this device are presented and discussed, together with electronics design issues. PMID:22163518

  4. Depopulation of Caged Layer Hens with a Compressed Air Foam System

    Science.gov (United States)

    Gurung, Shailesh; Hoffman, John; Stringfellow, Kendre; Abi-Ghanem, Daad; Zhao, Dan; Caldwell, David; Lee, Jason; Styles, Darrel; Berghman, Luc; Byrd, James; Farnell, Yuhua; Archer, Gregory

    2018-01-01

    Simple Summary Reportable diseases, such as avian influenza, spread rapidly among poultry, resulting in the death of a large number of birds. Once such a disease has been diagnosed at a farm, infected and susceptible birds are rapidly killed to prevent the spread of the disease. The methods to eliminate infected caged laying hens are limited. An experiment was conducted to study the effectiveness of foam made from compressed air, water, and soap to kill laying hens in cages. The study found that stress levels of the hens killed using compressed air foam in cages to be similar to the hens killed by carbon dioxide or the negative control. Hens exposed to carbon dioxide died earlier as compared to the foam methods. The authors conclude that application of compressed air foam in cages is an alternative to methods such as gas inhalation and ventilation shutdown to rapidly and humanely kill laying hens during epidemics. Abstract During the 2014–2015 US highly pathogenic avian influenza (HPAI) outbreak, 50.4 million commercial layers and turkeys were affected, resulting in economic losses of $3.3 billion. Rapid depopulation of infected poultry is vital to contain and eradicate reportable diseases like HPAI. The hypothesis of the experiment was that a compressed air foam (CAF) system may be used as an alternative to carbon dioxide (CO2) inhalation for depopulating caged layer hens. The objective of this study was to evaluate corticosterone (CORT) and time to cessation of movement (COM) of hens subjected to CAF, CO2 inhalation, and negative control (NEG) treatments. In Experiment 1, two independent trials were conducted using young and spent hens. Experiment 1 consisted of five treatments: NEG, CO2 added to a chamber, a CO2 pre-charged chamber, CAF in cages, and CAF in a chamber. In Experiment 2, only spent hens were randomly assigned to three treatments: CAF in cages, CO2 added to a chamber, and aspirated foam. Serum CORT levels of young hens were not significantly

  5. Study and design of a hybrid wind-diesel-compressed air system for providing electricity to a remote telecommunication station; Etudes et conception d'un systeme hybride eolien-diesel-air comprime pour l'electrification d'une station de telecommunications isolee

    Energy Technology Data Exchange (ETDEWEB)

    Ibrahim, H.; Dimitrova, M. [TechnoCentre eolien Gaspesie-les Iles, Gaspe, PQ (Canada); Ilinca, A. [Quebec Univ., Rimouski, PQ (Canada); Perron, J. [Quebec Univ., Chicoutimi, PQ (Canada)

    2010-07-01

    This poster reported on a study that examined the feasibility of using a hybrid wind-diesel-compressed air system to produce electricity at remote telecommunication stations. Low and high penetration wind-diesel hybrid systems were studied in order to reduce the diesel consumption. The use of a high penetration wind-diesel system together with compressed air energy storage (CAES) was shown to be a viable alternative to improve the overall percentage of renewable energy and reduce the cost of electricity in remote areas where a good wind resource is available. Different technical solutions for the CAES system were compared. refs., figs.

  6. Quantitative Analysis of Major Phytochemicals in Orthodox tea (Camellia sinensis), Oxidized under Compressed Air Environment.

    Science.gov (United States)

    Panda, Brajesh Kumar; Datta, Ashis Kumar

    2016-04-01

    This study describes major changes in phytochemical composition of orthodox tea (Camellia sinensis var. Assamica) oxidized under compressed air (CA). The experiments for oxidation were conducted under air pressure (101, 202, and 303 kPa) for 150 min. Relative change in the concentrations of caffeine, catechins, theaflavins (TF), and thearubigins (TR) were analyzed. Effect of CA pressure was found to be nonsignificant in regulating caffeine concentration during oxidation. But degradation in different catechins as well as formation of different TF was significantly affected by CA pressure. At high CA pressure, TF showed highest peak value. TR was found to have slower rate of formation during initial phase of oxidation than TF. Even though the rate of TR formation was significantly influenced by CA, a portion of catechins remained unoxidized at end of oxidation. Except caffeine, the percent change in rate of formation or degradation were more prominent at 202 kPa. © 2016 Institute of Food Technologists®

  7. The Use of Compressed Air for Micro-Jet Cooling After MIG Welding

    Directory of Open Access Journals (Sweden)

    Hadryś D.

    2016-09-01

    Full Text Available The material selected for this investigation was low alloy steel weld metal deposit (WMD after MIG welding with micro-jet cooling. The present investigation was aimed as the following tasks: obtained WMD with various amount of acicular ferrite and further analyze impact toughness of WMD in terms of acicular ferrite amount in it. Weld metal deposit (WMD was first time carried out for MIG welding with micro-jet cooling of compressed air and gas mixture of argon and air. Until that moment only argon, helium and nitrogen were tested as micro-jet gases for MIG/MAG processes. An important role in the interpretation of the results can give methods of artificial intelligence.

  8. Saturated-unsaturated flow to a well with storage in a compressible unconfined aquifer

    Science.gov (United States)

    Mishra, Phoolendra Kumar; Neuman, Shlomo P.

    2011-05-01

    Mishra and Neuman (2010) developed an analytical solution for flow to a partially penetrating well of zero radius in a compressible unconfined aquifer that allows inferring its saturated and unsaturated hydraulic properties from responses recorded in the saturated and/or unsaturated zones. Their solution accounts for horizontal as well as vertical flows in each zone. It represents unsaturated zone constitutive properties in a manner that is at once mathematically tractable and sufficiently flexible to provide much improved fits to standard constitutive models. In this paper we extend the solution of [2010] to the case of a finite diameter pumping well with storage; investigate the effects of storage in the pumping well and delayed piezometer response on drawdowns in the saturated and unsaturated zones as functions of position and time; validate our solution against numerical simulations of drawdown in a synthetic aquifer having unsaturated properties described by the [1980]- [1976] model; use our solution to analyze 11 transducer-measured drawdown records from a seven-day pumping test conducted by University of Waterloo researchers at the Canadian Forces Base Borden in Ontario, Canada; validate our parameter estimates against manually-measured drawdown records in 14 other piezometers at Borden; and compare (a) our estimates of aquifer parameters with those obtained on the basis of all these records by [2008], (b) on the basis of 11 transducer-measured drawdown records by [2007], (c) our estimates of van Genuchten-Mualem parameters with those obtained on the basis of laboratory drainage data from the site by [1992], and (d) our corresponding prediction of how effective saturation varies with elevation above the initial water table under static conditions with a profile based on water contents measured in a neutron access tube at a radial distance of about 5 m from the center of the pumping well. We also use our solution to analyze 11 transducer-measured drawdown

  9. Introduction of a compressed air breathing apparatus for the offshore oil and gas industry.

    Science.gov (United States)

    Brooks, Chris J; MacDonald, Conor V; Carroll, Joel; Gibbs, Peter N G

    2010-07-01

    When a helicopter ditches the majority of crew and passengers have to make an underwater escape. Some may not be able to hold their breath and will drown. For at least 15 yr, military aircrew have been trained to use a scuba system. In the offshore oil and gas industry, there has been more caution about introducing a compressed air system and a rebreather system has been introduced as an alternative. Recently, Canadian industry and authorities approved the introduction of Helicopter Underwater Emergency Breathing Apparatus (HUEBA) training using compressed air. This communication reports the training of the first 1000 personnel. Training was introduced in both Nova Scotia and Newfoundland concurrently by the same group of instructors. Trainees filled out a questionnaire concerning their perceived ratings of the ease or difficulty of classroom training and the practical use of the HUEBA. Ninety-eight percent of trainees found the classroom and in-water training to be "good/very good". Trainees found it to be "easy/very easy" to clear the HUEBA and breathe underwater in 84% and 64% of cases, respectively. Divers reported a greater ease in learning all the practical uses of the HUEBA except application of the nose clip. There were problems with the nose clip fitting incorrectly, and interference of the survival suit hood with the regulator, which subsequently have been resolved. When carefully applied, the introduction of the HUEBA into training for offshore oil and gas industry helicopter crew and passengers can be safely conducted.

  10. Photo-acoustic sensor for detection of oil contamination in compressed air systems.

    Science.gov (United States)

    Lassen, Mikael; Harder, David Baslev; Brusch, Anders; Nielsen, Ole Stender; Heikens, Dita; Persijn, Stefan; Petersen, Jan C

    2017-02-06

    We demonstrate an online (in-situ) sensor for continuous detection of oil contamination in compressed air systems complying with the ISO-8573 standard. The sensor is based on the photo-acoustic (PA) effect. The online and real-time PA sensor system has the potential to benefit a wide range of users that require high purity compressed air. Among these are hospitals, pharmaceutical industries, electronics manufacturers, and clean room facilities. The sensor was tested for sensitivity, repeatability, robustness to molecular cross-interference, and stability of calibration. Explicit measurements of hexane (C6H14) and decane (C10H22) vapors via excitation of molecular C-H vibrations at approx. 2950 cm-1 (3.38 μm) were conducted with a custom made interband cascade laser (ICL). For the decane measurements a (1 σ) standard deviation (STD) of 0.3 ppb was demonstrated, which corresponds to a normalized noise equivalent absorption (NNEA) coefficient for the prototype PA sensor of 2.8×10-9 W cm-1 Hz1/2.

  11. Factors that influence the tribocharging of pulverulent materials in compressed-air devices

    Energy Technology Data Exchange (ETDEWEB)

    Das, S; Medles, K; Mihalcioiu, A; Beleca, R; Dragan, C; Dascalescu, L [Laboratory of Aerodynamic Studies, University of Poitiers, University Institute of Technology, Angouleme, 16021 (France)], E-mail: ldascalescu@iutang.univ-poitiers.fr

    2008-12-01

    Tribocharging of pulverulent materials in compressed-air devices is a typical multi-factorial process. This paper aims at demonstrating the interest of using the design of experiments methodology in association with virtual instrumentation for quantifying the effects of various process varaibles and of their interactions, as a prerequisite for the development of new tribocharging devices for industrial applications. The study is focused on the tribocharging of PVC powders in compressed-air devices similar to those employed in electrostatic painting. A classical 2 full-factorial design (3 factors at two levels) was employed for conducting the experiments. The response function was the charge/mass ratio of the material collected in a modified Faraday cage, at the exit of the tribocharging device. The charge/mass ratio was found to increase with the injection pressure and the vortex pressure in the tribocharging device, and to decrease with the increasing of the feed rate. In the present study an in-house design of experiments software was employed for statistical analysis of experimental data and validation of the experimental model.

  12. Carbon and Energy Saving Financial Opportunities in the Industrial Compressed Air Sector

    Science.gov (United States)

    Vittorini, Diego; Cipollone, Roberto

    2017-08-01

    The transition towards a more sustainable energy scenario calls for both medium-to-long and short term interventions, with CO2 reduction and fossil fuel saving as main goals for all the Countries in the World. Among all others, one way to support these efforts is the setting-up of immaterial markets able to regulate, in the form of purchase and sales quotas, CO2 emissions avoided and fossil fuels not consumed. As a consequence, the upgrade of those sectors, characterized by high energy impact, is currently more than an option due to the related achievable financial advantage on the afore mentioned markets. Being responsible for about 10% electricity consumption in Industry, the compressed air sector is currently addressed as extremely appealing, when CO2 emissions and burned fossil fuels saving are in question. In the paper, once a standard is defined for compressors performances, based on data from the Compressed Air and Gas Institute and PNEUROP, the achievable energy saving is evaluated along with the effect in terms of CO2 emissions: with reference to those contexts in which mature intangible markets are established, an estimation of the financial benefit from savings sale on correspondent markets is possible, in terms of both avoided CO2 and fossil fuels not burned. The approach adopted allows to extend the analysis results to every context of interest, by applying the appropriate emission factor to the datum on compressor specific consumption.

  13. Factors that influence the tribocharging of pulverulent materials in compressed-air devices

    International Nuclear Information System (INIS)

    Das, S; Medles, K; Mihalcioiu, A; Beleca, R; Dragan, C; Dascalescu, L

    2008-01-01

    Tribocharging of pulverulent materials in compressed-air devices is a typical multi-factorial process. This paper aims at demonstrating the interest of using the design of experiments methodology in association with virtual instrumentation for quantifying the effects of various process varaibles and of their interactions, as a prerequisite for the development of new tribocharging devices for industrial applications. The study is focused on the tribocharging of PVC powders in compressed-air devices similar to those employed in electrostatic painting. A classical 2 full-factorial design (3 factors at two levels) was employed for conducting the experiments. The response function was the charge/mass ratio of the material collected in a modified Faraday cage, at the exit of the tribocharging device. The charge/mass ratio was found to increase with the injection pressure and the vortex pressure in the tribocharging device, and to decrease with the increasing of the feed rate. In the present study an in-house design of experiments software was employed for statistical analysis of experimental data and validation of the experimental model.

  14. A comparison of sputum induction methods: ultrasonic vs compressed-air nebulizer and hypertonic vs isotonic saline inhalation.

    Science.gov (United States)

    Loh, L C; Eg, K P; Puspanathan, P; Tang, S P; Yip, K S; Vijayasingham, P; Thayaparan, T; Kumar, S

    2004-03-01

    Airway inflammation can be demonstrated by the modem method of sputum induction using ultrasonic nebulizer and hypertonic saline. We studied whether compressed-air nebulizer and isotonic saline which are commonly available and cost less, are as effective in inducing sputum in normal adult subjects as the above mentioned tools. Sixteen subjects underwent weekly sputum induction in the following manner: ultrasonic nebulizer (Medix Sonix 2000, Clement Clarke, UK) using hypertonic saline, ultrasonic nebulizer using isotonic saline, compressed-air nebulizer (BestNeb, Taiwan) using hypertonic saline, and compressed-air nebulizer using isotonic saline. Overall, the use of an ultrasonic nebulizer and hypertonic saline yielded significantly higher total sputum cell counts and a higher percentage of cell viability than compressed-air nebulizers and isotonic saline. With the latter, there was a trend towards squamous cell contaminations. The proportion of various sputum cell types was not significantly different between the groups, and the reproducibility in sputum macrophages and neutrophils was high (Intraclass correlation coefficient, r [95%CI]: 0.65 [0.30-0.91] and 0.58 [0.22-0.89], p compressed-air nebulizers and isotonic saline. We conclude that in normal subjects, although both nebulizers and saline types can induce sputum with reproducible cellular profile, ultrasonic nebulizers and hypertonic saline are more effective but less well tolerated.

  15. Swiss Compressed Air - Development of instruments for the 2005 - 2008 campaign; Druckluft Schweiz. Instrumentenentwicklung fuer die Kampagne 2005-2008

    Energy Technology Data Exchange (ETDEWEB)

    Radgen, P. [Fraunhofer-Institut fuer System- und Innovationsforschung (ISI), Karlsruhe (Germany); Jochem, E. [Swiss Federal Institute of Technology (ETH), Centre for Energy Policy and Economics (CEPE), Zuerich (Switzerland)

    2007-01-15

    This final report for the Swiss Federal Office of Energy (SFOE) takes a look at the development of a programme concerning the optimisation of compressed-air installations in Switzerland. The programme, which is to run from 2005 to 2008, aims to support operators of compressed-air equipment in the optimisation of their installations. The work to be done in co-operation with research institutes, manufacturers and a marketing company is reviewed. A series of tools is described which was developed during 2005 and 2006 to help systems' operators analyse and optimise their compressed air systems. As well as guidelines on optimisation, modernisation and new construction, an Internet-based benchmarking system and tools for heat recovery, leaks, the correct dimensioning of pipes and condensate drains. were developed. The report describes these tools and presents documentation on the subject, including screen-shots of the Internet platform.

  16. Ice Storage Air-Conditioning System Simulation with Dynamic Electricity Pricing: A Demand Response Study

    Directory of Open Access Journals (Sweden)

    Chi-Chun Lo

    2016-02-01

    Full Text Available This paper presents an optimal dispatch model of an ice storage air-conditioning system for participants to quickly and accurately perform energy saving and demand response, and to avoid the over contact with electricity price peak. The schedule planning for an ice storage air-conditioning system of demand response is mainly to transfer energy consumption from the peak load to the partial-peak or off-peak load. Least Squares Regression (LSR is used to obtain the polynomial function for the cooling capacity and the cost of power consumption with a real ice storage air-conditioning system. Based on the dynamic electricity pricing, the requirements of cooling loads, and all technical constraints, the dispatch model of the ice-storage air-conditioning system is formulated to minimize the operation cost. The Improved Ripple Bee Swarm Optimization (IRBSO algorithm is proposed to solve the dispatch model of the ice storage air-conditioning system in a daily schedule on summer. Simulation results indicate that reasonable solutions provide a practical and flexible framework allowing the demand response of ice storage air-conditioning systems to demonstrate the optimization of its energy savings and operational efficiency and offering greater energy efficiency.

  17. Heat recovery from compressed air in sludge activation plants; Waermerueckgewinnung aus der Druckluft von Belebungsanlagen

    Energy Technology Data Exchange (ETDEWEB)

    Strunkheide, J.; Eckhardt, R.; Witte, H. [IWB Gemeinnuetziges Inst. Wasser und Boden e.V., Sankt Augustin (Germany)

    2002-07-01

    The Herdorf sewage system is presented as an example of heat recovery from compressed air of the activation stage. Consumption of externally supplied fuel (heating oil) was minimised, and full-scale power generation from sewage gas provided additional income. The key element of the heat recovery system is the air cooler with a matched double-shell heat exchanger. Temperatures and water volumes on the heating water side can be varied in order to ensure optimum heat supply to the air cooler at any time. The heat is used in the internal heating system to heat up the raw sludge in the fermentation process. [German] Die Waermerueckgewinnung aus der Druckluft von Belebungsanlagen kann einen wesentlichen Beitrag zum Waermehaushalt von Klaeranlagen liefern, wie hier am Beispiel der Klaeranlage Herdorf erlaeutert wurde. Hierdurch konnte zum einen der Einsatz von Fremdbrennstoffen (Heizoel) auf ein Minimum reduziert und zum anderen konnten zusaetzliche Ertraege aus der vollstaendigen Verstromung des Faulgases erzielt werden. Kernstueck der Waermerueckgewinnungsanlage bildet der Luftkuehler und der darauf abgestimmte Doppelmantelrohr-Waermeuebertrager. Von wesentlicher Bedeutung ist hierbei, dass auf der Heizkreiswasserseite mit variablen Heizwassermengen und korrespondierenden Temperaturen gefahren werden kann, um zu jedem Zeitpunkt die optimale Waerme durch den Luftkuehler bedarfsorientiert abgreifen zu koennen. Die Waerme dient zur Einspeisung in das Betriebs-Heizungssystem und damit zur Rohschlamm-Aufheizung im Faulungsprozess. (orig.)

  18. Work plan for upgrading the 241-A-701 compressed air system and motor control center. Revision 1

    International Nuclear Information System (INIS)

    Carpenter, K.E.

    1995-01-01

    This work plan will outline the responsibilities associated with the 241-A-701 Compressed Air System (CAS) and Motor Control Center (MCC) upgrades. All activities required to design, install, test, and operate the modified systems are addressed in this document. Upgrades Technical Support (UTS) of TWRS Engineering is responsible for the completion of all tasks associated with this upgrade. UTS will coordinate the upgrade activities, and ensure all tasks are successfully completed on or before the scheduled dates. The primary objective of the 241-A-701 Compressor and MCC Upgrade is to provide a reliable source of process and instrument compressed air to the A, AX, AY, and AZ tank farms

  19. A method for predicting the impact velocity of a projectile fired from a compressed air gun facility

    International Nuclear Information System (INIS)

    Attwood, G.J.

    1988-03-01

    This report describes the development and use of a method for calculating the velocity at impact of a projectile fired from a compressed air gun. The method is based on a simple but effective approach which has been incorporated into a computer program. The method was developed principally for use with the Horizontal Impact Facility at AEE Winfrith but has been adapted so that it can be applied to any compressed air gun of a similar design. The method has been verified by comparison of predicted velocities with test data and the program is currently being used in a predictive manner to specify test conditions for the Horizontal Impact Facility at Winfrith. (author)

  20. Changes in ocean circulation and carbon storage are decoupled from air-sea CO2 fluxes

    Science.gov (United States)

    Marinov, I.; Gnanadesikan, A.

    2011-02-01

    The spatial distribution of the air-sea flux of carbon dioxide is a poor indicator of the underlying ocean circulation and of ocean carbon storage. The weak dependence on circulation arises because mixing-driven changes in solubility-driven and biologically-driven air-sea fluxes largely cancel out. This cancellation occurs because mixing driven increases in the poleward residual mean circulation result in more transport of both remineralized nutrients and heat from low to high latitudes. By contrast, increasing vertical mixing decreases the storage associated with both the biological and solubility pumps, as it decreases remineralized carbon storage in the deep ocean and warms the ocean as a whole.

  1. Relevance of postmortem radiology to the diagnosis of fatal cerebral gas embolism from compressed air diving.

    Science.gov (United States)

    Cole, A J; Griffiths, D; Lavender, S; Summers, P; Rich, K

    2006-05-01

    To test the hypothesis that artefact caused by postmortem off-gassing is at least partly responsible for the presence of gas within the vascular system and tissues of the cadaver following death associated with compressed air diving. Controlled experiment sacrificing sheep after a period of simulated diving in a hyperbaric chamber and carrying out sequential postmortem computed tomography (CT) on the cadavers. All the subject sheep developed significant quantities of gas in the vascular system within 24 hours, as demonstrated by CT and necropsy, while the control animals did not. The presence of gas in the vascular system of human cadavers following diving associated fatalities is to be expected, and is not necessarily connected with gas embolism following pulmonary barotrauma, as has previously been claimed.

  2. Death from Barotrauma Due to Compressed Air: A Medico-legal Analysis.

    Science.gov (United States)

    Giugliano, Pasquale; Massoni, Francesco; Crisci, Antonello; Ricci, Serafino

    2016-11-01

    Lesions of the digestive tract due to barotrauma resulting from compressed air application are not common, are rarely lethal, and largely affect the sigmoid and descending colon. Moreover, their pathogenic mechanism is a topic of discussion because these lesions have multiple characteristics. Here, the authors describe an autoptic case of death from lesions of the ascending and transverse segments, with perforations and bleeding suffusions as well as ischemic areas covered the colonic wall that was extremely thinned, congested, and hemorrhagic, with considerable flattening leading to disappearance of the mucosal folds and with numerous petechial hemorrhages. The pathological framework of lung congestion made it possible to identify the mechanism responsible for this death as depletion of the heart's pumping function, which contributed significantly to the acute respiratory failure due to respiratory distress as well as to reduced mobility of the diaphragm due to intestinal distension. Acute heart failure played an important role in this death. © 2016 American Academy of Forensic Sciences.

  3. Compressed air demand-type firefighter's breathing system, volume 1. [design analysis and performance tests

    Science.gov (United States)

    Sullivan, J. L.

    1975-01-01

    The commercial availability of lightweight high pressure compressed air vessels has resulted in a lightweight firefighter's breathing apparatus. The improved apparatus, and details of its design and development are described. The apparatus includes a compact harness assembly, a backplate mounted pressure reducer assembly, a lightweight bubble-type facemask with a mask mounted demand breathing regulator. Incorporated in the breathing regulator is exhalation valve, a purge valve and a whistle-type low pressure warning that sounds only during inhalation. The pressure reducer assembly includes two pressure reducers, an automatic transfer valve and a signaling device for the low pressure warning. Twenty systems were fabricated, tested, refined through an alternating development and test sequence, and extensively examined in a field evaluation program. Photographs of the apparatus are included.

  4. Integrated LTCC Pressure/Flow/Temperature Multisensor for Compressed Air Diagnostics†

    Directory of Open Access Journals (Sweden)

    Nicolas Craquelin

    2010-12-01

    Full Text Available We present a multisensor designed for industrial compressed air diagnostics and combining the measurement of pressure, flow, and temperature, integrated with the corresponding signal conditioning electronics in a single low-temperature co-fired ceramic (LTCC package. The developed sensor may be soldered onto an integrated electro-fluidic platform by using standard surface mount device (SMD technology, e.g., as a standard electronic component would be on a printed circuit board, obviating the need for both wires and tubes and thus paving the road towards low-cost integrated electro-fluidic systems. Several performance aspects of this device are presented and discussed, together with electronics design issues.

  5. Experimental Results Obtained with Air Liquide Cold Compression System CERN LHC and SNS Projects

    CERN Document Server

    Delcayre, F; Hamber, F; Hilbert, B; Monneret, E; Toia, J L

    2006-01-01

    Large scale collider facilities will make intensive use of superconducting magnets, operating below 2.0 K. This dictates high‐capacity refrigeration systems operating below 2.0 K. These systems, making use of cryogenic centrifugal compressors in a series arrangement with room temperature screw compressors will be coupled to a refrigerator, providing a certain power at 4.5 K. A first Air Liquide Cold Compression System (CCS) unit was built and delivered to CERN in 2001. Installed at the beginning of 2002, it was commissioned and tested successfully during year 2002. A series of four sets of identical CCS were then tested in 2004. Another set of four cryogenic centrifugal compressors (CCC) has been delivered to Thomas Jefferson National Accelerator Facility (JLAB) for the Spallation Neutron Source (SNS) in 2002. These compressors were tested and commissioned from December 2004 to July 2005. The experimental results obtained with these systems will be presented and discussed: the characteristics of the CCC wil...

  6. Reducing disk storage of full-3D seismic waveform tomography (F3DT) through lossy online compression

    Science.gov (United States)

    Lindstrom, Peter; Chen, Po; Lee, En-Jui

    2016-08-01

    Full-3D seismic waveform tomography (F3DT) is the latest seismic tomography technique that can assimilate broadband, multi-component seismic waveform observations into high-resolution 3D subsurface seismic structure models. The main drawback in the current F3DT implementation, in particular the scattering-integral implementation (F3DT-SI), is the high disk storage cost and the associated I/O overhead of archiving the 4D space-time wavefields of the receiver- or source-side strain tensors. The strain tensor fields are needed for computing the data sensitivity kernels, which are used for constructing the Jacobian matrix in the Gauss-Newton optimization algorithm. In this study, we have successfully integrated a lossy compression algorithm into our F3DT-SI workflow to significantly reduce the disk space for storing the strain tensor fields. The compressor supports a user-specified tolerance for bounding the error, and can be integrated into our finite-difference wave-propagation simulation code used for computing the strain fields. The decompressor can be integrated into the kernel calculation code that reads the strain fields from the disk and compute the data sensitivity kernels. During the wave-propagation simulations, we compress the strain fields before writing them to the disk. To compute the data sensitivity kernels, we read the compressed strain fields from the disk and decompress them before using them in kernel calculations. Experiments using a realistic dataset in our California statewide F3DT project have shown that we can reduce the strain-field disk storage by at least an order of magnitude with acceptable loss, and also improve the overall I/O performance of the entire F3DT-SI workflow significantly. The integration of the lossy online compressor may potentially open up the possibilities of the wide adoption of F3DT-SI in routine seismic tomography practices in the near future.

  7. Vapor Compression Refrigeration System for Cold Storage on Spacecrafts, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — NASA is looking for a high efficiency long term food storage system for space crafts. Previous refrigerator/freezer systems developed for this application such as...

  8. Energy managemant through PCM based thermal storage system for building air-conditioning: Tidel Park, Chennai

    International Nuclear Information System (INIS)

    Nallusamy, N.; Sampath, S.; Velraj, R.

    2006-01-01

    Many modern building are designed for air-conditioning and the amount of electrical energy required for providing air-conditioning can be very significant especially in the tropics. Conservation of energy is major concern to improve the overall efficiency of the system. Integration is energy storage with the conventional system gives a lot of potential for energy saving and long-term economics. Thermal energy storage systems can improve energy management and help in matching supply and demand patterns. In the present work, a detailed study has been done on the existing thermal energy storage system used in the air-conditioning system in Tidel Park, Chennai. The present study focuses on the cool energy storage system. The modes of operation and advantages of such a system for energy management are highlighted. The reason for the adoption of combined storage system and the size of the storage medium in the air-conditioning plant are analyzed. The possibility of using this concept in other cooling and heating applications, such as storage type solar water heating system, has been explored

  9. Reduced injection pressures using a compressed air injection technique (CAIT): an in vitro study.

    Science.gov (United States)

    Tsui, Ban C H; Knezevich, Mark P; Pillay, Jennifer J

    2008-01-01

    High injection pressures have been associated with intraneural injection and persistent neurological injury in animals. Our objective was to test whether a reported simple compressed air injection technique (CAIT) would limit the generation of injection pressures to below a suggested 1,034 mm Hg limit in an in vitro model. After ethics board approval, 30 consenting anesthesiologists injected saline into a semiclosed system. Injection pressures using 30 mL syringes connected to a 22 gauge needle and containing 20 mL of saline were measured for 60 seconds using: (1) a typical "syringe feel" method, and (2) CAIT, thereby drawing 10 mL of air above the saline and compressing this to 5 mL prior to and during injections. All anesthesiologists performed the syringe feel method before introduction and demonstration of CAIT. Using CAIT, no anesthesiologist generated pressures above 1,034 mm Hg, while 29 of 30 produced pressures above this limit at some time using the syringe feel method. The mean pressure using CAIT was lower (636 +/- 71 vs. 1378 +/- 194 mm Hg, P = .025), and the syringe feel method resulted in higher peak pressures (1,875 +/- 206 vs. 715 +/- 104 mm Hg, P = .000). This study demonstrated that CAIT can effectively keep injection pressures under 1,034 mm Hg in this in vitro model. Animal and clinical studies will be needed to determine whether CAIT will allow objective, real-time pressure monitoring. If high pressure injections are proven to contribute to nerve injury in humans, this technique may have the potential to improve the safety of peripheral nerve blocks.

  10. Progress in electrical energy storage system:A critical review

    Institute of Scientific and Technical Information of China (English)

    Haisheng Chen; Thang Ngoc Cong; Wei Yang; Chunqing Tan; Yongliang Li; Yulong Ding

    2009-01-01

    Electrical energy storage technologies for stationary applications are reviewed.Particular attention is paid to pumped hydroelectric storage,compressed air energy storage,battery,flow battery,fuel cell,solar fuel,superconducting magnetic energy storage, flywheel, capacitor/supercapacitor,and thermal energy torage.Comparison is made among these technologies in terms of technical characteris-tics,applications and deployment status.

  11. No Cost – Low Cost Compressed Air System Optimization in Industry

    Science.gov (United States)

    Dharma, A.; Budiarsa, N.; Watiniasih, N.; Antara, N. G.

    2018-04-01

    Energy conservation is a systematic, integrated of effort, in order to preserve energy sources and improve energy utilization efficiency. Utilization of energy in efficient manner without reducing the energy usage it must. Energy conservation efforts are applied at all stages of utilization, from utilization of energy resources to final, using efficient technology, and cultivating an energy-efficient lifestyle. The most common way is to promote energy efficiency in the industry on end use and overcome barriers to achieve such efficiency by using system energy optimization programs. The facts show that energy saving efforts in the process usually only focus on replacing tools and not an overall system improvement effort. In this research, a framework of sustainable energy reduction work in companies that have or have not implemented energy management system (EnMS) will be conducted a systematic technical approach in evaluating accurately a compressed-air system and potential optimization through observation, measurement and verification environmental conditions and processes, then processing the physical quantities of systems such as air flow, pressure and electrical power energy at any given time measured using comparative analysis methods in this industry, to provide the potential savings of energy saving is greater than the component approach, with no cost to the lowest cost (no cost - low cost). The process of evaluating energy utilization and energy saving opportunities will provide recommendations for increasing efficiency in the industry and reducing CO2 emissions and improving environmental quality.

  12. Physico-chemical characterization of grain dust in storage air of Bangalore.

    Science.gov (United States)

    Mukherjee, A K; Nag, D P; Kakde, Y; Babu, K R; Prdkash, M N; Rao, S R

    1998-06-01

    An Anderson personal cascade impactor was used to study the particle mass size distribution in the storage air of two major grain storage centers in Bangalore. Dust levels in storage air as well as the personal exposures of workers were determined along with a detailed study on the particle size distribution. Protein and carbohydrate content of the dust were also determined respectively in the phosphate buffer saline (PBS) and water extracts by using the standard analytical techniques. Personal exposures in both of the grain storage centers have been found to be much above the limit prescribed by ACGIH (1995-96). But the results of particle size analysis showed a higher particle mass distribution in the non-respirable size range. The mass median diameters (MMD) of the storage air particulate of both the centers were found to be beyond the respirable range. Presence of protein and carbohydrate in the storage air dust is indicative of the existence of glyco-proteins, mostly of membrane origin.

  13. Monitoring plan for routine organic air emissions at the Radioactive Waste Management Complex Waste Storage Facilities

    International Nuclear Information System (INIS)

    Galloway, K.J.; Jolley, J.G.

    1994-06-01

    This monitoring plan provides the information necessary to perform routine organic air emissions monitoring at the Waste Storage Facilities located at the Transuranic Storage Area of the Radioactive Waste Management Complex at the Idaho National Engineering Laboratory. The Waste Storage Facilities include both the Type I and II Waste Storage Modules. The plan implements a dual method approach where two dissimilar analytical methodologies, Open-Path Fourier Transform Infrared Spectroscopy (OP-FTIR) and ancillary SUMMA reg-sign canister sampling, following the US Environmental Protection Agency (EPA) analytical method TO-14, will be used to provide qualitative and quantitative volatile organic concentration data. The Open-Path Fourier Transform Infrared Spectroscopy will provide in situ, real time monitoring of volatile organic compound concentrations in the ambient air of the Waste Storage Facilities. To supplement the OP-FTIR data, air samples will be collected using SUMMA reg-sign, passivated, stainless steel canisters, following the EPA Method TO-14. These samples will be analyzed for volatile organic compounds with gas chromatograph/mass spectrometry analysis. The sampling strategy, procedures, and schedules are included in this monitoring plan. The development of this monitoring plan is driven by regulatory compliance to the Resource Conservation and Recovery Act, State of Idaho Toxic Air Pollutant increments, Occupational Safety and Health Administration. The various state and federal regulations address the characterization of the volatile organic compounds and the resultant ambient air emissions that may originate from facilities involved in industrial production and/or waste management activities

  14. Influence of extensive compressed natural gas (CNG) usage on air quality

    Science.gov (United States)

    Suthawaree, Jeeranut; Sikder, Helena Akhter; Jones, Charlotte Emily; Kato, Shungo; Kunimi, Hitoshi; Mohammed Hamidul Kabir, Abu Naser; Kajii, Yoshizumi

    2012-07-01

    Compressed Natural Gas (CNG) is an inexpensive, indigenous energy resource which currently accounts for the majority of automobile and domestic energy consumption in Bangladesh. This extensive CNG usage, particularly within the capital city, Dhaka, heavily influences the atmospheric composition (and hence air quality), yet to date measurements of trace gases in regions dominated by CNG emissions are relatively limited. Here we report continuous observations of the atmospherically important trace gases O3, CO, SO2, NOx and volatile organic compounds (VOC), in ambient air in Dhaka City, Bangladesh, during May 2011. The average mixing ratios of O3, CO, SO2, and NOx for the measurement period were 18.9, 520.9, 7.6 and 21.5 ppbv, respectively. The ratios of CO to NO reveal that emissions from gasoline and CNG-fuelled vehicles were dominant during the daytime (slope of ˜26), while in contrast, owing to restrictions imposed on diesel fuelled vehicles entering Dhaka City, emissions from these vehicles only became significant during the night (slope of ˜10). The total VOC mixing ratio in Dhaka was ˜5-10 times higher than the levels reported in more developed Asian cities such as Tokyo and Bangkok, which consequently gives rise to a higher ozone formation potential (OFP). However, the most abundant VOC in Dhaka were the relatively long-lived ethane and propane (with mean mixing ratios of ˜115 and ˜30 ppbv, respectively), and as a consequence, the ozone formation potential per ppb carbon (ppbC) was lower in Dhaka than in Tokyo and Bangkok. Thus the atmospheric composition of air influenced by extensive CNG combustion may be characterized by high VOC mixing ratios, yet mixing ratios of the photochemical pollutant ozone do not drastically exceed the levels typical of Asian cities with considerably lower VOC levels.

  15. Carbon Dioxide and Nitrogen Infused Compressed Air Foam for Depopulation of Caged Laying Hens.

    Science.gov (United States)

    Gurung, Shailesh; White, Dima; Archer, Gregory; Styles, Darrel; Zhao, Dan; Farnell, Yuhua; Byrd, James; Farnell, Morgan

    2018-01-03

    Depopulation of infected poultry flocks is a key strategy to control and contain reportable diseases. Water-based foam, carbon dioxide inhalation, and ventilation shutdown are depopulation methods available to the poultry industry. Unfortunately, these methods have limited usage in caged layer hen operations. Personnel safety and welfare of birds are equally important factors to consider during emergency depopulation procedures. We have previously reported that compressed air foam (CAF) is an alternative method for depopulation of caged layer hens. We hypothesized that infusion of gases, such as carbon dioxide (CO₂) and nitrogen (N₂), into the CAF would reduce physiological stress and shorten time to cessation of movement. The study had six treatments, namely a negative control, CO₂ inhalation, N₂ inhalation, CAF with air (CAF Air), CAF with 50% CO₂ (CAF CO₂), and CAF with 100% N₂ (CAF N₂). Four spent hens were randomly assigned to one of these treatments on each of the eight replication days. A total of 192 spent hens were used in this study. Serum corticosterone and serotonin levels were measured and compared between treatments. Time to cessation of movement of spent hens was determined using accelerometers. The addition of CO₂ in CAF significantly reduced the foam quality while the addition of N₂ did not. The corticosterone and serotonin levels of spent hens subjected to foam (CAF, CAF CO₂, CAF N₂) and gas inhalation (CO₂, N₂) treatments did not differ significantly. The time to cessation of movement of spent hens in the CAF N₂ treatment was significantly shorter than CAF and CAF CO₂ treatments but longer than the gas inhalation treatments. These data suggest that the addition of N₂ is advantageous in terms of shortening time to death and improved foam quality as compared to the CAF CO₂ treatment.

  16. DNABIT Compress - Genome compression algorithm.

    Science.gov (United States)

    Rajarajeswari, Pothuraju; Apparao, Allam

    2011-01-22

    Data compression is concerned with how information is organized in data. Efficient storage means removal of redundancy from the data being stored in the DNA molecule. Data compression algorithms remove redundancy and are used to understand biologically important molecules. We present a compression algorithm, "DNABIT Compress" for DNA sequences based on a novel algorithm of assigning binary bits for smaller segments of DNA bases to compress both repetitive and non repetitive DNA sequence. Our proposed algorithm achieves the best compression ratio for DNA sequences for larger genome. Significantly better compression results show that "DNABIT Compress" algorithm is the best among the remaining compression algorithms. While achieving the best compression ratios for DNA sequences (Genomes),our new DNABIT Compress algorithm significantly improves the running time of all previous DNA compression programs. Assigning binary bits (Unique BIT CODE) for (Exact Repeats, Reverse Repeats) fragments of DNA sequence is also a unique concept introduced in this algorithm for the first time in DNA compression. This proposed new algorithm could achieve the best compression ratio as much as 1.58 bits/bases where the existing best methods could not achieve a ratio less than 1.72 bits/bases.

  17. Electricity storage - A challenge for energy transition

    International Nuclear Information System (INIS)

    Bart, Jean-Baptiste; Nekrasov, Andre; Pastor, Emmanuel; Benefice, Emmanuel; Brincourt, Thierry; Cagnac, Albannie; Brisse, Annabelle; Jeandel, Elodie; Lefebvre, Thierry; Penneau, Jean-Francois; Radvanyi, Etienne; Delille, Gautier; Hinchliffe, Timothee; Lancel, Gilles; Loevenbruck, Philippe; Soler, Robert; Stevens, Philippe; Torcheux, Laurent

    2017-01-01

    After a presentation of the energetic context and of its issues, this collective publication proposes presentations of various electricity storage technologies with a distinction between direct storage, thermal storage and hydrogen storage. As far as direct storage is concerned, the following options are described: pumped energy transfer stations or PETS, compressed air energy storage or CAES, flywheels, various types of electrochemical batteries (lead, alkaline, sodium, lithium), metal air batteries, redox flow batteries, and super-capacitors. Thermal storage comprises power-to-heat and heat-to-power technologies. Hydrogen can be stored under different forms (compressed gas, liquid), in saline underground cavities, or by using water electrolysis and fuel cells. The authors propose an overview of the different services provided by energy storage to the electricity system, and discuss the main perspectives and challenges for tomorrow's storage (electric mobility, integration of renewable energies, electrification of isolated areas, scenarios of development)

  18. Air pollution impacts from carbon capture and storage (CCS)

    Energy Technology Data Exchange (ETDEWEB)

    Harmelen, T. van; Horssen, A. van; Jozwicka, M.; Pulles, T. (TNO, Delft (Netherlands)); Odeh, N. (AEA Technology, Harwell (United Kingdom)); Adams, M. (EEA, Copenhagen (Denmark))

    2011-11-15

    This report comprises two separate complementary parts that address the links between CCS implementation and its subsequent impacts on GHG and air pollutant emissions on a life-cycle basis: Part A discusses and presents key findings from the latest literature, focusing upon the potential air pollution impacts across the CCS life-cycle arising from the implementation of the main foreseen technologies. Both negative and positive impacts on air quality are presently suggested in the literature - the basis of scientific knowledge on these issues is rapidly advancing. Part B comprises a case study that quantifies and highlights the range of GHG and air pollutant life-cycle emissions that could occur by 2050 under a low-carbon pathway should CCS be implemented in power plants across the European Union under various hypothetical scenarios. A particular focus of the study was to quantify the main life-cycle emissions of the air pollutants taking into account the latest knowledge on air pollutant emission factors and life-cycle aspects of the CCS life-cycle as described in Part A of the report. Pollutants considered in the report were the main GHGs CO{sub 2}, methane (CH{sub 4}) and nitrous oxide (N{sub 2}O) and the main air pollutants with potential to harm human health and/or the environment - nitrogen oxides (NO{sub X}), sulphur dioxide (SO{sub 2}), ammonia (NH{sub 3}), non-methane volatile organic compounds (NMVOCs) and particulate matter (PM{sub 10}). (Author)

  19. Measuring Device for Air Speed in Macroporous Media and Its Application Inside Apple Storage Bins

    Directory of Open Access Journals (Sweden)

    Martin Geyer

    2018-02-01

    Full Text Available In cold storage facilities of fruit and vegetables, airflow is necessary for heat removal. The design of storage facilities influences the air speed in the surrounding of the product. Therefore, knowledge about airflow next to the product is important to plan the layout of cold stores adapted to the requirements of the products. A new sensing device (ASL, Air speed logger is developed for omnidirectional measurement of air speed between fruit or vegetables inside storage bins or in bulk. It consists of four interconnected plastic spheres with 80 mm diameter each, adapted to the size of apple fruit. In the free space between the spheres, silicon diodes are fixed for the airflow measurement based on a calorimetric principle. Battery and data logger are mounted inside the spheres. The device is calibrated in a wind tunnel in a measuring range of 0–1.3 m/s. Air speed measurements in fruit bulks on laboratory scale and in an industrial fruit store show air speeds in gaps between fruit with high stability at different airflow levels. Several devices can be placed between stored products for determination of the air speed distribution inside bulks or bin stacks in a storage room.

  20. Demonstration of acoustic source localization in air using single pixel compressive imaging

    Science.gov (United States)

    Rogers, Jeffrey S.; Rohde, Charles A.; Guild, Matthew D.; Naify, Christina J.; Martin, Theodore P.; Orris, Gregory J.

    2017-12-01

    Acoustic source localization often relies on large sensor arrays that can be electronically complex and have large data storage requirements to process element level data. Recently, the concept of a single-pixel-imager has garnered interest in the electromagnetics literature due to its ability to form high quality images with a single receiver paired with shaped aperture screens that allow for the collection of spatially orthogonal measurements. Here, we present a method for creating an acoustic analog to the single-pixel-imager found in electromagnetics for the purpose of source localization. Additionally, diffraction is considered to account for screen openings comparable to the acoustic wavelength. A diffraction model is presented and incorporated into the single pixel framework. In this paper, we explore the possibility of applying single pixel localization to acoustic measurements. The method is experimentally validated with laboratory measurements made in an air waveguide.

  1. Estimation of air void and aggregate spatial distributions in concrete under uniaxial compression using computer tomography scanning

    International Nuclear Information System (INIS)

    Wong, R.C.K.; Chau, K.T.

    2005-01-01

    Normal- and high-strength concrete cylinders (designed compressive strengths of 30 and 90 MPa at 28 days) were loaded uniaxially. Computer tomography (CT) scanning technique was used to examine the evolution of air voids inside the specimens at various loading states up to 85% of the ultimate compressive strength. The normal-strength concrete yielded a very different behaviour in changes of internal microstructure as compared to the high-strength concrete. There were significant instances of nucleation and growth in air voids in the normal-strength concrete specimen, while the increase in air voids in the high-strength concrete specimen was insignificant. In addition, CT images were used for mapping the aggregate spatial distributions within the specimens. No intrinsic anisotropy was detected from the fabric analysis

  2. Anti-seismic analysis for air storage tank used in the nuclear power plant

    International Nuclear Information System (INIS)

    Hua Jun; Ren Xin; Feng Ping

    2011-01-01

    This text calculates and analyses the structure of the air storage tank used for the SBO diesel generator set of Taishan nuclear power plant through finite element method, and simply introduces the mechanical modeling, loading condition and seismic response spectrum analyzing method for the structure, then get the natural frequency, vibration mode and response under seismic load of the structure through calculation. Evaluate the stress under the combined load such as gravity, internal stress, earthquake of the structure according to RCCM. The result shows that the structure intensity of the air storage tank meets the requirements of the specification. The calculating result gives the accordance for the seismic design of the air storage tank. (authors)

  3. Compressed Speech: Potential Application for Air Force Technical Training. Final Report, August 73-November 73.

    Science.gov (United States)

    Dailey, K. Anne

    Time-compressed speech (also called compressed speech, speeded speech, or accelerated speech) is an extension of the normal recording procedure for reproducing the spoken word. Compressed speech can be used to achieve dramatic reductions in listening time without significant loss in comprehension. The implications of such temporal reductions in…

  4. Technical Assessment of Cryo-Compressed Hydrogen Storage Tank Systems for Automotive Applications

    Energy Technology Data Exchange (ETDEWEB)

    Ahluwalia, Rajesh [Argonne National Lab. (ANL), Argonne, IL (United States); Hua, T. Q. [Argonne National Lab. (ANL), Argonne, IL (United States); Peng, J. -K. [Argonne National Lab. (ANL), Argonne, IL (United States); Lasher, S. [TIAX LLC, Lexington, MA (United States); McKenney, Kurtis [TIAX LLC, Lexington, MA (United States); Sinha, J. [TIAX LLC, Lexington, MA (United States)

    2009-12-01

    Technical report describing DOE's second assessment report on a third generation (Gen3) system capable of storing hydrogen at cryogenic temperatures within a pressure vessel on-board a vehicle. The report includes an overview of technical progress to date, including the potential to meet DOE onboard storage targets, as well as independent reviews of system cost and energy analyses of the technology paired with delivery costs.

  5. Evaluation of Two Compressed Air Foam Systems for Culling Caged Layer Hens

    Directory of Open Access Journals (Sweden)

    Eric R. Benson

    2018-04-01

    Full Text Available Outbreaks of avian influenza (AI and other highly contagious poultry diseases continue to be a concern for those involved in the poultry industry. In the situation of an outbreak, emergency depopulation of the birds involved is necessary. In this project, two compressed air foam systems (CAFS were evaluated for mass emergency depopulation of layer hens in a manure belt equipped cage system. In both experiments, a randomized block design was used with multiple commercial layer hens treated with one of three randomly selected depopulation methods: CAFS, CAFS with CO2 gas, and CO2 gas. In Experiment 1, a Rowe manufactured CAFS was used, a selection of birds were instrumented, and the time to unconsciousness, brain death, altered terminal cardiac activity and motion cessation were recorded. CAFS with and without CO2 was faster to unconsciousness, however, the other parameters were not statistically significant. In Experiment 2, a custom Hale based CAFS was used to evaluate the impact of bird age, a selection of birds were instrumented, and the time to motion cessation was recorded. The difference in time to cessation of movement between pullets and spent hens using CAFS was not statistically significant. Both CAFS depopulate caged layers, however, there was no benefit to including CO2.

  6. Evaluation of Two Compressed Air Foam Systems for Culling Caged Layer Hens.

    Science.gov (United States)

    Benson, Eric R; Weiher, Jaclyn A; Alphin, Robert L; Farnell, Morgan; Hougentogler, Daniel P

    2018-04-24

    Outbreaks of avian influenza (AI) and other highly contagious poultry diseases continue to be a concern for those involved in the poultry industry. In the situation of an outbreak, emergency depopulation of the birds involved is necessary. In this project, two compressed air foam systems (CAFS) were evaluated for mass emergency depopulation of layer hens in a manure belt equipped cage system. In both experiments, a randomized block design was used with multiple commercial layer hens treated with one of three randomly selected depopulation methods: CAFS, CAFS with CO₂ gas, and CO₂ gas. In Experiment 1, a Rowe manufactured CAFS was used, a selection of birds were instrumented, and the time to unconsciousness, brain death, altered terminal cardiac activity and motion cessation were recorded. CAFS with and without CO₂ was faster to unconsciousness, however, the other parameters were not statistically significant. In Experiment 2, a custom Hale based CAFS was used to evaluate the impact of bird age, a selection of birds were instrumented, and the time to motion cessation was recorded. The difference in time to cessation of movement between pullets and spent hens using CAFS was not statistically significant. Both CAFS depopulate caged layers, however, there was no benefit to including CO₂.

  7. Experimental Results Obtained with Air Liquide Cold Compression System: CERN LHC and SNS Projects

    Science.gov (United States)

    Delcayre, F.; Courty, J.-C.; Hamber, F.; Hilbert, B.; Monneret, E.; Toia, J.-L.

    2006-04-01

    Large scale collider facilities will make intensive use of superconducting magnets, operating below 2.0 K. This dictates high-capacity refrigeration systems operating below 2.0 K. These systems, making use of cryogenic centrifugal compressors in a series arrangement with room temperature screw compressors will be coupled to a refrigerator, providing a certain power at 4.5 K. A first Air Liquide Cold Compression System (CCS) unit was built and delivered to CERN in 2001. Installed at the beginning of 2002, it was commissioned and tested successfully during year 2002. A series of four sets of identical CCS were then tested in 2004. Another set of four cryogenic centrifugal compressors (CCC) has been delivered to Thomas Jefferson National Accelerator Facility (JLAB) for the Spallation Neutron Source (SNS) in 2002. These compressors were tested and commissioned from December 2004 to July 2005. The experimental results obtained with these systems will be presented and discussed: the characteristics of the CCC will be detailed. The principles of control for the CCC in series will be detailed.

  8. Thermal and economical optimization of air conditioning units with vapor compression refrigeration system

    Energy Technology Data Exchange (ETDEWEB)

    Sanaye, S.; Malekmohammadi, H.R. [Iran University of Science and Technology, Tehran (Iran). Dept. of Mechanical Engineering

    2004-09-01

    A new method of thermal and economical optimum design of air conditioning units with vapor compression refrigeration system, is presented. Such a system includes compressor, condenser, evaporator, centrifugal and axial fans. Evaporator and condenser temperatures, their heating surface areas (frontal surface area and number of tubes), centrifugal and axial fan powers, and compressor power are among the design variables. The data provided by manufacturers for fan (volume flow rate versus pressure drop) and compressor power (using evaporator and condenser temperatures) was used to choose these components directly from available data for consumers. To study the performance of the system under various situations, and implementing the optimization procedure, a simulation program including all thermal and geometrical parameters was developed. The objective function for optimization was the total cost per unit cooling load of the system including capital investment for components as well as the required electricity cost. To find the system design parameters, this objective function was minimized by Lagrange multipliers method. The effects of changing the cooling load on optimal design parameters were studied. (author)

  9. Unintended inhalation of nitric oxide by contamination of compressed air: physiologic effects and interference with intended nitric oxide inhalation in acute lung injury.

    Science.gov (United States)

    Benzing, A; Loop, T; Mols, G; Geiger, K

    1999-10-01

    Compressed air from a hospital's central gas supply may contain nitric oxide as a result of air pollution. Inhaled nitric oxide may increase arterial oxygen tension and decrease pulmonary vascular resistance in patients with acute lung injury and acute respiratory distress syndrome. Therefore, the authors wanted to determine whether unintentional nitric oxide inhalation by contamination of compressed air influences arterial oxygen tension and pulmonary vascular resistance and interferes with the therapeutic use of nitric oxide. Nitric oxide concentrations in the compressed air of a university hospital were measured continuously by chemiluminescence during two periods (4 and 2 weeks). The effects of unintended nitric oxide inhalation on arterial oxygen tension (n = 15) and on pulmonary vascular resistance (n = 9) were measured in patients with acute lung injury and acute respiratory distress syndrome by changing the source of compressed air of the ventilator from the hospital's central gas supply to a nitric oxide-free gas tank containing compressed air. In five of these patients, the effects of an additional inhalation of 5 ppm nitric oxide were evaluated. During working days, compressed air of the hospital's central gas supply contained clinically effective nitric oxide concentrations (> 80 parts per billion) during 40% of the time. Change to gas tank-supplied nitric oxide-free compressed air decreased the arterial oxygen tension by 10% and increased pulmonary vascular resistance by 13%. The addition of 5 ppm nitric oxide had a minimal effect on arterial oxygen tension and pulmonary vascular resistance when added to hospital-supplied compressed air but improved both when added to tank-supplied compressed air. Unintended inhalation of nitric oxide increases arterial oxygen tension and decreases pulmonary vascular resistance in patients with acute lung injury and acute respiratory distress syndrome. The unintended nitric oxide inhalation interferes with the

  10. Air exposure and sample storage time influence on hydrogen release from tungsten

    Energy Technology Data Exchange (ETDEWEB)

    Moshkunov, K.A., E-mail: moshkunov@gmail.co [National Research Nuclear University ' MEPhI' , Kashirskoe sh. 31, 115409 Moscow (Russian Federation); Schmid, K.; Mayer, M. [Max-Planck-Institut fuer Plasmaphysik, EURATOM Association, Boltzmannstrasse 2, D-85748 Garching (Germany); Kurnaev, V.A.; Gasparyan, Yu.M. [National Research Nuclear University ' MEPhI' , Kashirskoe sh. 31, 115409 Moscow (Russian Federation)

    2010-09-30

    In investigations of hydrogen retention in first wall components the influence of the conditions of the implanted target storage prior to analysis and the storage time is often neglected. Therefore we have performed a dedicated set of experiments. The release of hydrogen from samples exposed to ambient air after irradiation was compared to samples kept in vacuum. For air exposed samples significant amounts of HDO and D{sub 2}O are detected during TDS. Additional experiments have shown that heavy water is formed by recombination of releasing D and H atoms with O on the W surface. This water formation can alter hydrogen retention results significantly, in particular - for low retention cases. In addition to the influence of ambient air exposure also the influence of storage time in vacuum was investigated. After implantation at 300 K the samples were stored in vacuum for up to 1 week during which the retained amount decreased significantly. The subsequently measured TDS spectra showed that D was lost from both the high and low energy peaks during storage at ambient temperature of {approx}300 K. An attempt to simulate this release from both peaks during room temperature storage by TMAP 7 calculations showed that this effect cannot be explained by conventional diffusion/trapping models.

  11. Air exposure and sample storage time influence on hydrogen release from tungsten

    International Nuclear Information System (INIS)

    Moshkunov, K.A.; Schmid, K.; Mayer, M.; Kurnaev, V.A.; Gasparyan, Yu.M.

    2010-01-01

    In investigations of hydrogen retention in first wall components the influence of the conditions of the implanted target storage prior to analysis and the storage time is often neglected. Therefore we have performed a dedicated set of experiments. The release of hydrogen from samples exposed to ambient air after irradiation was compared to samples kept in vacuum. For air exposed samples significant amounts of HDO and D 2 O are detected during TDS. Additional experiments have shown that heavy water is formed by recombination of releasing D and H atoms with O on the W surface. This water formation can alter hydrogen retention results significantly, in particular - for low retention cases. In addition to the influence of ambient air exposure also the influence of storage time in vacuum was investigated. After implantation at 300 K the samples were stored in vacuum for up to 1 week during which the retained amount decreased significantly. The subsequently measured TDS spectra showed that D was lost from both the high and low energy peaks during storage at ambient temperature of ∼300 K. An attempt to simulate this release from both peaks during room temperature storage by TMAP 7 calculations showed that this effect cannot be explained by conventional diffusion/trapping models.

  12. Air exposure and sample storage time influence on hydrogen release from tungsten

    Science.gov (United States)

    Moshkunov, K. A.; Schmid, K.; Mayer, M.; Kurnaev, V. A.; Gasparyan, Yu. M.

    2010-09-01

    In investigations of hydrogen retention in first wall components the influence of the conditions of the implanted target storage prior to analysis and the storage time is often neglected. Therefore we have performed a dedicated set of experiments. The release of hydrogen from samples exposed to ambient air after irradiation was compared to samples kept in vacuum. For air exposed samples significant amounts of HDO and D 2O are detected during TDS. Additional experiments have shown that heavy water is formed by recombination of releasing D and H atoms with O on the W surface. This water formation can alter hydrogen retention results significantly, in particular - for low retention cases. In addition to the influence of ambient air exposure also the influence of storage time in vacuum was investigated. After implantation at 300 K the samples were stored in vacuum for up to 1 week during which the retained amount decreased significantly. The subsequently measured TDS spectra showed that D was lost from both the high and low energy peaks during storage at ambient temperature of ˜300 K. An attempt to simulate this release from both peaks during room temperature storage by TMAP 7 calculations showed that this effect cannot be explained by conventional diffusion/trapping models.

  13. [Research on the incidence of decompression sickness in compressed air works. The development of its recent five years' study].

    Science.gov (United States)

    Mano, Y; Shibayama, M; Matsui, Y

    1987-07-01

    Compressed air works have been used as the safest construction work for the basic underground or underwater compressed shield or caisson works in Japan; however, the workers who were exposed to the compressed fields must have put themselves at risk of decompression sickness. Decompression sickness is generally considered to be due to the bubble effects and the bubbles originate from the supersaturated gas dissolved in the blood and other tissues. The standard decompression schedule by the Ministry of Labor has been practically applied at the end of compressed air works, and the laborers decompress slowly from the bottom pressure to the surface according to the schedule. It is difficult to completely prevent the sickness and the average percentage of contracting "bends," using the Japanese standard decompression schedule, is considered to be 0.54%. But previous papers reported higher incidences from 1.42 to 3.3% or more. We have continued an actual investigation on the incidence, and the number of the exposed trials amounted to nearly a hundred thousand. These data were compared between recent five years' group and before. Eventually, it was ascertained that the incidence has been significantly decreased in the recent five years; however, greater care in occupational safety control is still needed.

  14. Storage of HLW in engineered structures: air-cooled and water-cooled concepts

    International Nuclear Information System (INIS)

    Ahner, S.; Dekais, J.J.; Puttke, B.; Staner, P.

    1981-01-01

    A comparative study on an air-cooled and a water-cooled intermediate storage of vitrified, highly radioactive waste (HLW) in overground installations has been performed by Nukem and Belgonucleaire respectively. In the air-cooled storage concept the decay heat from the storage area will be removed using natural convection. In the water-cooled storage concept the decay heat is carried off by a primary and secondary forced-cooling system with redundant and diverse devices. The safety study carried out by Nukem used a fault tree method. It shows that the reliability of the designed water-cooled system is very high and comparable to the inherent, safe, air-cooled system. The impact for both concepts on the environment is determined by the release route, but even during accident conditions the release is far below permissible limits. The economic analysis carried out by Belgonucleaire shows that the construction costs for both systems do not differ very much, but the operation and maintenance costs for the water-cooled facility are higher than for the air cooled facility. The result of the safety and economic analysis and the discussions with the members of the working group have shown some possible significant modifications for both systems, which are included in this report. The whole study has been carried out using certain national criteria which, in certain Member States at least, would lead to a higher standard of safety than can be justified on any social, political or economic grounds

  15. TECHNOLOGIES TO ENHANCE THE OPERATION OF EXISTING NATURAL GAS COMPRESSION INFRASTRUCTURE - MANIFOLD DESIGN FOR CONTROLLING ENGINE AIR BALANCE

    Energy Technology Data Exchange (ETDEWEB)

    Gary D. Bourn; Ford A. Phillips; Ralph E. Harris

    2005-12-01

    This document provides results and conclusions for Task 15.0--Detailed Analysis of Air Balance & Conceptual Design of Improved Air Manifolds in the ''Technologies to Enhance the Operation of Existing Natural Gas Compression Infrastructure'' project. SwRI{reg_sign} is conducting this project for DOE in conjunction with Pipeline Research Council International, Gas Machinery Research Council, El Paso Pipeline, Cooper Compression, and Southern Star, under DOE contract number DE-FC26-02NT41646. The objective of Task 15.0 was to investigate the perceived imbalance in airflow between power cylinders in two-stroke integral compressor engines and develop solutions via manifold redesign. The overall project objective is to develop and substantiate methods for operating integral engine/compressors in gas pipeline service, which reduce fuel consumption, increase capacity, and enhance mechanical integrity.

  16. Changes in ocean circulation and carbon storage are decoupled from air-sea CO2 fluxes

    Directory of Open Access Journals (Sweden)

    A. Gnanadesikan

    2011-02-01

    Full Text Available The spatial distribution of the air-sea flux of carbon dioxide is a poor indicator of the underlying ocean circulation and of ocean carbon storage. The weak dependence on circulation arises because mixing-driven changes in solubility-driven and biologically-driven air-sea fluxes largely cancel out. This cancellation occurs because mixing driven increases in the poleward residual mean circulation result in more transport of both remineralized nutrients and heat from low to high latitudes. By contrast, increasing vertical mixing decreases the storage associated with both the biological and solubility pumps, as it decreases remineralized carbon storage in the deep ocean and warms the ocean as a whole.

  17. Allowable spent LWR fuel storage temperatures in inert gases, nitrogen, and air

    International Nuclear Information System (INIS)

    Gilbert, E.R.; Cunningham, M.E.; Simonen, E.P.; Thomas, L.E.; Campbell, T.K.; Barnhart, D.M.

    1990-01-01

    Spent fuel in inert dry storage is now a reality in the US; recommended maximum temperature-time conditions are specified in an IBM PC-compatible code. However, spent fuel cannot yet be stored in air because the data and theory needed for predicting allowable temperatures are still being developed. Tests to determine the behavior of spent UO 2 fragments and breached rod specimens in air are providing data that will be used to determine the temperatures that can be allowed for fuel stored in air. 13 refs., 5 figs

  18. Handling the data management needs of high-throughput sequencing data: SpeedGene, a compression algorithm for the efficient storage of genetic data

    Science.gov (United States)

    2012-01-01

    Background As Next-Generation Sequencing data becomes available, existing hardware environments do not provide sufficient storage space and computational power to store and process the data due to their enormous size. This is and will be a frequent problem that is encountered everyday by researchers who are working on genetic data. There are some options available for compressing and storing such data, such as general-purpose compression software, PBAT/PLINK binary format, etc. However, these currently available methods either do not offer sufficient compression rates, or require a great amount of CPU time for decompression and loading every time the data is accessed. Results Here, we propose a novel and simple algorithm for storing such sequencing data. We show that, the compression factor of the algorithm ranges from 16 to several hundreds, which potentially allows SNP data of hundreds of Gigabytes to be stored in hundreds of Megabytes. We provide a C++ implementation of the algorithm, which supports direct loading and parallel loading of the compressed format without requiring extra time for decompression. By applying the algorithm to simulated and real datasets, we show that the algorithm gives greater compression rate than the commonly used compression methods, and the data-loading process takes less time. Also, The C++ library provides direct-data-retrieving functions, which allows the compressed information to be easily accessed by other C++ programs. Conclusions The SpeedGene algorithm enables the storage and the analysis of next generation sequencing data in current hardware environment, making system upgrades unnecessary. PMID:22591016

  19. Single-Site Active Iron-Based Bifunctional Oxygen Catalyst for a Compressible and Rechargeable Zinc-Air Battery.

    Science.gov (United States)

    Ma, Longtao; Chen, Shengmei; Pei, Zengxia; Huang, Yan; Liang, Guojin; Mo, Funian; Yang, Qi; Su, Jun; Gao, Yihua; Zapien, Juan Antonio; Zhi, Chunyi

    2018-02-27

    The exploitation of a high-efficient, low-cost, and stable non-noble-metal-based catalyst with oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) simultaneously, as air electrode material for a rechargeable zinc-air battery is significantly crucial. Meanwhile, the compressible flexibility of a battery is the prerequisite of wearable or/and portable electronics. Herein, we present a strategy via single-site dispersion of an Fe-N x species on a two-dimensional (2D) highly graphitic porous nitrogen-doped carbon layer to implement superior catalytic activity toward ORR/OER (with a half-wave potential of 0.86 V for ORR and an overpotential of 390 mV at 10 mA·cm -2 for OER) in an alkaline medium. Furthermore, an elastic polyacrylamide hydrogel based electrolyte with the capability to retain great elasticity even under a highly corrosive alkaline environment is utilized to develop a solid-state compressible and rechargeable zinc-air battery. The creatively developed battery has a low charge-discharge voltage gap (0.78 V at 5 mA·cm -2 ) and large power density (118 mW·cm -2 ). It could be compressed up to 54% strain and bent up to 90° without charge/discharge performance and output power degradation. Our results reveal that single-site dispersion of catalytic active sites on a porous support for a bifunctional oxygen catalyst as cathode integrating a specially designed elastic electrolyte is a feasible strategy for fabricating efficient compressible and rechargeable zinc-air batteries, which could enlighten the design and development of other functional electronic devices.

  20. Thermodynamic characteristics of a novel wind-solar-liquid air energy storage system

    Science.gov (United States)

    Ji, W.; Zhou, Y.; Sun, Y.; Zhang, W.; Pan, C. Z.; Wang, J. J.

    2017-12-01

    Due to the nature of fluctuation and intermittency, the utilization of wind and solar power will bring a huge impact to the power grid management. Therefore a novel hybrid wind-solar-liquid air energy storage (WS-LAES) system was proposed. In this system, wind and solar power are stored in the form of liquid air by cryogenic liquefaction technology and thermal energy by solar thermal collector, respectively. Owing to the high density of liquid air, the system has a large storage capacity and no geographic constraints. The WS-LAES system can store unstable wind and solar power for a stable output of electric energy and hot water. Moreover, a thermodynamic analysis was carried out to investigate the best system performance. The result shows that the increases of compressor adiabatic efficiency, turbine inlet pressure and inlet temperature all have a beneficial effect.

  1. Depopulation of Caged Layer Hens with a Compressed Air Foam System.

    Science.gov (United States)

    Gurung, Shailesh; Hoffman, John; Stringfellow, Kendre; Abi-Ghanem, Daad; Zhao, Dan; Caldwell, David; Lee, Jason; Styles, Darrel; Berghman, Luc; Byrd, James; Farnell, Yuhua; Archer, Gregory; Farnell, Morgan

    2018-01-11

    During the 2014-2015 US highly pathogenic avian influenza (HPAI) outbreak, 50.4 million commercial layers and turkeys were affected, resulting in economic losses of $3.3 billion. Rapid depopulation of infected poultry is vital to contain and eradicate reportable diseases like HPAI. The hypothesis of the experiment was that a compressed air foam (CAF) system may be used as an alternative to carbon dioxide (CO₂) inhalation for depopulating caged layer hens. The objective of this study was to evaluate corticosterone (CORT) and time to cessation of movement (COM) of hens subjected to CAF, CO₂ inhalation, and negative control (NEG) treatments. In Experiment 1, two independent trials were conducted using young and spent hens. Experiment 1 consisted of five treatments: NEG, CO₂ added to a chamber, a CO₂ pre-charged chamber, CAF in cages, and CAF in a chamber. In Experiment 2, only spent hens were randomly assigned to three treatments: CAF in cages, CO₂ added to a chamber, and aspirated foam. Serum CORT levels of young hens were not significantly different among the CAF in cages, CAF in a chamber, NEG control, and CO₂ inhalation treatments. However, spent hens subjected to the CAF in a chamber had significantly higher CORT levels than birds in the rest of the treatments. Times to COM of spent hens subjected to CAF in cages and aspirated foam were significantly greater than of birds exposed to the CO₂ in a chamber treatment. These data suggest that applying CAF in cages is a viable alternative for layer hen depopulation during a reportable disease outbreak.

  2. Integration of ceramic membrane and compressed air-assisted solvent extraction (CASX) for metal recovery.

    Science.gov (United States)

    Li, Chi-Wang; Chiu, Chun-Hao; Lee, Yu-Cheng; Chang, Chia-Hao; Lee, Yu-Hsun; Chen, Yi-Ming

    2010-01-01

    In our previous publications, compressed air-assisted solvent extraction process (CASX) was developed and proved to be kinetically efficient process for metal removal. In the current study, CASX with a ceramic MF membrane integrated for separation of spent solvent was employed to remove and recover metal from wastewater. MF was operated either in crossflow mode or dead-end with intermittent flushing mode. Under crossflow mode, three distinct stages of flux vs. TMP (trans-membrane pressure) relationship were observed. In the first stage, flux increases with increasing TMP which is followed by the stage of stable flux with increasing TMP. After reaching a threshold TMP which is dependent of crossflow velocity, flux increases again with increasing TMP. At the last stage, solvent was pushed through membrane pores as indicated by increasing permeate COD. In dead-end with intermittent flushing mode, an intermittent flushing flow (2 min after a 10-min or a 30-min dead-end filtration) was incorporated to reduce membrane fouling by flush out MSAB accumulated on membrane surface. Effects of solvent concentration and composition were also investigated. Solvent concentrations ranging from 0.1 to 1% (w/w) have no adverse effect in terms of membrane fouling. However, solvent composition, i.e. D(2)EHPA/kerosene ratio, shows impact on membrane fouling. The type of metal extractants employed in CASX has significant impact on both membrane fouling and the quality of filtrate due to the differences in their viscosity and water solubility. Separation of MSAB was the limiting process controlling metal removal efficiency, and the removal efficiency of Cd(II) and Cr(VI) followed the same trend as that for COD.

  3. Depopulation of Caged Layer Hens with a Compressed Air Foam System

    Directory of Open Access Journals (Sweden)

    Shailesh Gurung

    2018-01-01

    Full Text Available During the 2014–2015 US highly pathogenic avian influenza (HPAI outbreak, 50.4 million commercial layers and turkeys were affected, resulting in economic losses of $3.3 billion. Rapid depopulation of infected poultry is vital to contain and eradicate reportable diseases like HPAI. The hypothesis of the experiment was that a compressed air foam (CAF system may be used as an alternative to carbon dioxide (CO2 inhalation for depopulating caged layer hens. The objective of this study was to evaluate corticosterone (CORT and time to cessation of movement (COM of hens subjected to CAF, CO2 inhalation, and negative control (NEG treatments. In Experiment 1, two independent trials were conducted using young and spent hens. Experiment 1 consisted of five treatments: NEG, CO2 added to a chamber, a CO2 pre-charged chamber, CAF in cages, and CAF in a chamber. In Experiment 2, only spent hens were randomly assigned to three treatments: CAF in cages, CO2 added to a chamber, and aspirated foam. Serum CORT levels of young hens were not significantly different among the CAF in cages, CAF in a chamber, NEG control, and CO2 inhalation treatments. However, spent hens subjected to the CAF in a chamber had significantly higher CORT levels than birds in the rest of the treatments. Times to COM of spent hens subjected to CAF in cages and aspirated foam were significantly greater than of birds exposed to the CO2 in a chamber treatment. These data suggest that applying CAF in cages is a viable alternative for layer hen depopulation during a reportable disease outbreak.

  4. Storage of LWR spent fuel in air: Volume 1: Design and operation of a spent fuel oxidation test facility

    International Nuclear Information System (INIS)

    Thornhill, C.K.; Campbell, T.K.; Thornhill, R.E.

    1988-12-01

    This report describes the design and operation and technical accomplishments of a spent-fuel oxidation test facility at the Pacific Northwest Laboratory. The objective of the experiments conducted in this facility was to develop a data base for determining spent-fuel dry storage temperature limits by characterizing the oxidation behavior of light-water reactor (LWR) spent fuels in air. These data are needed to support licensing of dry storage in air as an alternative to spent-fuel storage in water pools. They are to be used to develop and validate predictive models of spent-fuel behavior during dry air storage in an Independent Spent Fuel Storage Installation (ISFSI). The present licensed alternative to pool storage of spent fuel is dry storage in an inert gas environment, which is called inerted dry storage (IDS). Licensed air storage, however, would not require monitoring for maintenance of an inert-gas environment (which IDS requires) but does require the development of allowable temperature limits below which UO 2 oxidation in breached fuel rods would not become a problem. Scoping tests at PNL with nonirradiated UO 2 pellets and spent-fuel fragment specimens identified the need for a statistically designed test matrix with test temperatures bounding anticipated maximum acceptable air-storage temperatures. This facility was designed and operated to satisfy that need. 7 refs

  5. Adsorption cold storage system with zeolite-water working pair used for locomotive air conditioning

    International Nuclear Information System (INIS)

    Lu, Y.Z.; Wang, R.Z.; Zhang, M.; Jiangzhou, S.

    2003-01-01

    Adsorption cold storage has lately attracted attention for its large storage capacity and zero cold energy loss during the storing process. Thermodynamic and experimental studies on the cold storage capacity and the cold discharging process, in which the adsorber is either air cooled or adiabatic, have been presented. An adsorption cold storage system with zeolite-water working pair has been developed, and some operating results are summarized. This system is used for providing air conditioning for the driver's cab of an internal combustion locomotive. Unlike a normal adsorption air conditioner, the system starts running with the adsorption process, during which the cold energy stored is discharged, and ends running with the generation process. The adsorbent temperature decreases during the cold storing period between two runs. The refrigeration power output for the whole running cycle is about 4.1 kW. It appears that such a system is quite energetically efficient and is comparatively suitable for providing discontinuous refrigeration capacity when powered by low grade thermal energy, such as industrial exhausted heat or solar energy

  6. Ice thermal storage air conditioning system for electric load leveling; Denryoku heijunka to hyochikunetsu system

    Energy Technology Data Exchange (ETDEWEB)

    Shigenaga, Y. [Daikin Industries Ltd., Osaka (Japan)

    1998-08-15

    Thermal storage air conditioning system is the one to use energy stored into thermal storing materials by using night electric power and to operate effective air conditioning. Therefore, as load can be treated by the stored energy, volume of the apparatus can be reduced. And, by reduction of the consumed power at day time, it can contribute to leveling of electric power demand. In general, there are two types in the thermal storage method: one is a method to store as thermal energy, and the other is that to store as chemical energy. For conditions required for the storing materials, important elements on their actual uses are not only physical properties such as large thermal storage per unit and easy thermal in- and out-puts, but also safety, long-term reliability, and easy receiving and economics containing future. The ice thermal storage air conditioning system is classified at the viewpoint of type of ice, kind of thermal storing medium, melting method on using cooling and heating, kinds of thermal medium on cooling and heating. 3 refs., 5 figs., 2 tabs.

  7. Compressive Creep Behavior of NEXTEL(TradeMark) 720/Alumina Ceramic Matrix Composite at 1200 Degrees C in Air and in Steam Environment

    National Research Council Canada - National Science Library

    Szymczak, Neil R

    2006-01-01

    ...) 720/Alumina ceramic matrix composite at 1200 deg. C in air and 100% steam environments. The effects of creep loading history on the tensile and compressive material behavior will also be examined...

  8. The safe removal of frozen air from the annulus of an LH2 storage tank

    Science.gov (United States)

    Krenn, A.; Starr, S.; Youngquist, R.; Nurge, M.; Sass, J.; Fesmire, J.; Cariker, C.; Bhattacharya, A.

    2015-12-01

    Large Liquid Hydrogen (LH2) storage tanks are vital infrastructure for NASA. Eventually, air may leak into the evacuated and perlite filled annular region of these tanks. Although the vacuum level is monitored in this region, the extremely cold temperature causes all but the helium and neon constituents of air to freeze. A small, often unnoticeable pressure rise is the result. As the leak persists, the quantity of frozen air increases, as does the thermal conductivity of the insulation system. Consequently, a notable increase in commodity boil-off is often the first indicator of an air leak. Severe damage can result from normal draining of the tank. The warming air will sublimate which will cause a pressure rise in the annulus. When the pressure increases above the triple point, the frozen air will begin to melt and migrate downward. Collection of liquid air on the carbon steel outer shell may chill it below its ductility range, resulting in fracture. In order to avoid a structural failure, as described above, a method for the safe removal of frozen air is needed. A thermal model of the storage tank has been created using SINDA/FLUINT modelling software. Experimental work is progressing in an attempt to characterize the thermal conductivity of a perlite/frozen nitrogen mixture. A statistical mechanics model is being developed in parallel for comparison to experimental work. The thermal model will be updated using the experimental/statistical mechanical data, and used to simulate potential removal scenarios. This paper will address methodologies and analysis techniques for evaluation of two proposed air removal methods.

  9. Optimal study of a solar air heating system with pebble bed energy storage

    International Nuclear Information System (INIS)

    Zhao, D.L.; Li, Y.; Dai, Y.J.; Wang, R.Z.

    2011-01-01

    Highlights: → Use two kinds of circulation media in the solar collector. → Air heating and pebble bed heat storage are applied with different operating modes. → Design parameters of the system are optimized by simulation program. → It is found that the system can meet 32.8% of the thermal energy demand in heating season. → Annual solar fraction aims to be 53.04%. -- Abstract: The application of solar air collectors for space heating has attracted extensive attention due to its unique advantages. In this study, a solar air heating system was modeled through TRNSYS for a 3319 m 2 building area. This air heating system, which has the potential to be applied for space heating in the heating season (from November to March) and hot water supply all year around in North China, uses pebble bed and water storage tank as heat storage. Five different working modes were designed based on different working conditions: (1) heat storage mode, (2) heating by solar collector, (3) heating by storage bed, (4) heating at night and (5) heating by an auxiliary source. These modes can be operated through the on/off control of fan and auxiliary heater, and through the operation of air dampers manually. The design, optimization and modification of this system are described in this paper. The solar fraction of the system was used as the optimization parameter. Design parameters of the system were optimized by using the TRNSYS program, which include the solar collector area, installation angle of solar collector, mass flow rate through the system, volume of pebble bed, heat transfer coefficient of the insulation layer of the pebble bed and water storage tank, height and volume of the water storage tank. The TRNSYS model has been verified by data from the literature. Results showed that the designed solar system can meet 32.8% of the thermal energy demand in the heating season and 84.6% of the energy consumption in non-heating season, with a yearly average solar fraction of 53.04%.

  10. Effects of air jet duration and timing on the combustion characteristics of high-pressure air jet controlled compression ignition combustion mode in a hybrid pneumatic engine

    International Nuclear Information System (INIS)

    Long, Wuqiang; Meng, Xiangyu; Tian, Jiangping; Tian, Hua; Cui, Jingchen; Feng, Liyan

    2016-01-01

    Highlights: • A 3-D CFD model of the power cylinder in HPE was developed. • High-pressure air JCCI combustion mode includes two-stage high-temperature reaction. • The combustion phasing of the pre-mixture is controllable via the SOJ timing. • There exists an optimum SOJ timing for obtaining the highest combustion efficiency and shortest burning duration. - Abstract: The high-pressure air jet controlled compression ignition (JCCI) combustion mode was employed to control the premixed diesel compression ignition combustion phasing by using the compound thermodynamic cycle under all operating conditions, which is accomplished in a hybrid pneumatic engine (HPE). A three-dimensional computational fluid dynamics (CFD) numerical simulation coupled with reduced n-heptane chemical kinetics mechanism has been applied to investigate the effects of high-pressure air jet duration and the start of jet (SOJ) timing on the combustion characteristics in the power cylinder of HPE. By sweeping the high-pressure air jet durations from 6 to 14 °CA and SOJ timings from −12 °CA ATDC to the top dead center (TDC) under the air jet temperatures of 400 and 500 K, respectively, the low- and high-temperature reactions, combustion efficiency, as well as the combustion phasing and burning duration have been analyzed in detail. The results illustrated that a longer air jet duration results in a higher peak in the first-stage high-temperature reaction, and the short air jet duration of 6 °CA can lead to a higher combustion efficiency. The SOJ timing sweep results showed that there exists an optimum timing for obtaining the highest combustion efficiency and shortest burning duration.

  11. Optimal operation strategies of compressed air energy storage (CAES) on electricity spot markets with fluctuating prices

    DEFF Research Database (Denmark)

    Lund, Henrik; Salgi, Georges; Elmegaard, Brian

    2009-01-01

    on electricity spot markets by storing energy when electricity prices are low and producing electricity when prices are high. In order to make a profit on such markets, CAES plant operators have to identify proper strategies to decide when to sell and when to buy electricity. This paper describes three...... plants will not be able to achieve such optimal operation, since the fluctuations of spot market prices in the coming hours and days are not known. Consequently, two simple practical strategies have been identified and compared to the results of the optimal strategy. This comparison shows that...... independent computer-based methodologies which may be used for identifying the optimal operation strategy for a given CAES plant, on a given spot market and in a given year. The optimal strategy is identified as the one which provides the best business-economic net earnings for the plant. In practice, CAES...

  12. A review on compressed air energy storage - a pathway for smart grid and polygeneration

    OpenAIRE

    Venkataramani, Gayathri; Parankusam, Prasanna; Ramalingam, Velraj; Wang, Jihong

    2016-01-01

    The increase in energy demand and reduction in resources for conventional energy production along with various environmental impacts, promote the use of renewable energy for electricity generation and other energy-need applications around the world. Wind power has emerged as the biggest renewable energy source in the world, whose potential, when employed properly serves to provide the best power output. In order to achieve self-sustenance in energy supply and to match the critical needs of im...

  13. Control System Development for Power Generation from Small-Scale Compressed Air Energy Storage

    Science.gov (United States)

    2017-06-01

    35  Figure 26  Control Program Flowchart ...Figure 26 Control Program Flowchart 1. Resetting Variables The Micro850 has internal memory that stores the last state of variables when power is...Research, Energy Systems Technology Evaluation Program (ESTEP), under the technical monitoring of Stacey Curtis, Marissa Brand and Richard Carlin 10

  14. The optimum intermediate pressure of two-stages vapor compression refrigeration cycle for Air-Conditioning unit

    Science.gov (United States)

    Ambarita, H.; Sihombing, H. V.

    2018-03-01

    Vapor compression cycle is mainly employed as a refrigeration cycle in the Air-Conditioning (AC) unit. In order to save energy, the Coefficient of Performance (COP) of the need to be improved. One of the potential solutions is to modify the system into multi-stages vapor compression cycle. The suitable intermediate pressure between the high and low pressures is one of the design issues. The present work deals with the investigation of an optimum intermediate pressure of two-stages vapor compression refrigeration cycle. Typical vapor compression cycle that is used in AC unit is taken into consideration. The used refrigerants are R134a. The governing equations have been developed for the systems. An inhouse program has been developed to solve the problem. COP, mass flow rate of the refrigerant and compressor power as a function of intermediate pressure are plotted. It was shown that there exists an optimum intermediate pressure for maximum COP. For refrigerant R134a, the proposed correlations need to be revised.

  15. Subcutaneous emphysema, pneumomediastinum, pneumothorax, pneumoperitoneum, and pneumoretroperitoneum by insufflation of compressed air at the external genitalia in a child.

    Science.gov (United States)

    Muramori, Katsumi; Takahashi, Yukiko; Handa, Noritoshi; Aikawa, Hisayuki

    2009-04-01

    A 7-year-old girl with concurrent subcutaneous emphysema, pneumomediastinum, pneumothorax, pneumoperitoneum, and pneumoretroperitoneum arrived at our facility. Compressed air at 5 atm of pressure was insufflated through the nozzle of a spray gun over her external genitalia. She was admitted for a small amount of genital bleeding and significant subcutaneous emphysema extending from the cheek to the upper body. Radiographic examination of the abdomen was suggestive of a visceral perforation, but she was managed conservatively and discharged in satisfactory condition without surgical intervention. The female genitalia possibly served as the entry point for air into the retroperitoneum and peritoneal cavity, with subsequent migration of air through the esophageal hiatus that resulted in pneumomediastinum, pneumothorax, and extensive subcutaneous emphysema.

  16. Trans-anal barotrauma by compressed air leading to sigmoid perforation due to a dangerous practical joke.

    Science.gov (United States)

    Pahwa, Harvinder Singh; Kumar, Awanish; Srivastava, Rohit; Rai, Anurag

    2012-08-01

    To present a case report of trans-anal barotrauma by high-pressure compressed air jet as a dangerous practical joke, that is, playful insufflation of high-pressure air jet through the anal orifice resulting in sigmoid perforation. The patient presented to emergency a day later with complaints of severe pain in the abdomen and abdominal distension following insufflation of high-pressure air jet through the anus. On examination, he had signs suggestive of perforation peritonitis and x-ray of the abdomen showed gas under the diaphragm. An emergency exploratory laparotomy was performed which revealed a 4-cm perforation in the sigmoid colon. Resection of the segment containing perforation along with the surrounding devitalised part was done with double-barrel colostomy. Reversal of colostomy was done after 8 weeks. Follow-up was uneventful.

  17. Storage of LWR spent fuel in air. Volume 3, Results from exposure of spent fuel to fluorine-contaminated air

    International Nuclear Information System (INIS)

    Cunningham, M.E.; Thomas, L.E.

    1995-06-01

    The Behavior of Spent Fuel in Storage (BSFS) Project has conducted research to develop data on spent nuclear fuel (irradiated U0 2 ) that could be used to support design, licensing, and operation of dry storage installations. Test Series B conducted by the BSFS Project was designed as a long-term study of the oxidation of spent fuel exposed to air. It was discovered after the exposures were completed in September 1990 that the test specimens had been exposed to an atmosphere of bottled air contaminated with an unknown quantity of fluorine. This exposure resulted in the test specimens reacting with both the oxygen and the fluorine in the oven atmospheres. The apparent source of the fluorine was gamma radiation-induced chemical decomposition of the fluoro-elastomer gaskets used to seal the oven doors. This chemical decomposition apparently released hydrofluoric acid (HF) vapor into the oven atmospheres. Because the Test Series B specimens were exposed to a fluorine-contaminated oven atmosphere and reacted with the fluorine, it is recommended that the Test Series B data not be used to develop time-temperature limits for exposure of spent nuclear fuel to air. This report has been prepared to document Test Series B and present the collected data and observations

  18. Storage of LWR spent fuel in air. Volume 3, Results from exposure of spent fuel to fluorine-contaminated air

    Energy Technology Data Exchange (ETDEWEB)

    Cunningham, M.E.; Thomas, L.E.

    1995-06-01

    The Behavior of Spent Fuel in Storage (BSFS) Project has conducted research to develop data on spent nuclear fuel (irradiated U0{sub 2}) that could be used to support design, licensing, and operation of dry storage installations. Test Series B conducted by the BSFS Project was designed as a long-term study of the oxidation of spent fuel exposed to air. It was discovered after the exposures were completed in September 1990 that the test specimens had been exposed to an atmosphere of bottled air contaminated with an unknown quantity of fluorine. This exposure resulted in the test specimens reacting with both the oxygen and the fluorine in the oven atmospheres. The apparent source of the fluorine was gamma radiation-induced chemical decomposition of the fluoro-elastomer gaskets used to seal the oven doors. This chemical decomposition apparently released hydrofluoric acid (HF) vapor into the oven atmospheres. Because the Test Series B specimens were exposed to a fluorine-contaminated oven atmosphere and reacted with the fluorine, it is recommended that the Test Series B data not be used to develop time-temperature limits for exposure of spent nuclear fuel to air. This report has been prepared to document Test Series B and present the collected data and observations.

  19. Annual performance investigation and economic analysis of heating systems with a compression-assisted air source absorption heat pump

    International Nuclear Information System (INIS)

    Wu, Wei; Shi, Wenxing; Wang, Baolong; Li, Xianting

    2015-01-01

    Highlights: • Optimal compression ratio of CASAHP is obtained for the maximum energy saving rate. • Annual performance is improved by 10–20% compared to ASAHP without compression. • Energy saving rate is 17.7–29.2% and investment is reduced to 30–60% for CASAHP. • Both compression and partial-design enhance the economy with given energy saving. • Payback time is reduced from 12–32 to 3–6 years by compression and partial-design. - Abstract: The compression-assisted air source absorption heat pump (CASAHP) is a promising alternative heating system in severe operating conditions. In this research, parameter studies on the annual performance under various compression ratios (CRs) and source temperatures are performed to achieve the maximum energy saving rates (ESRs). Economic analyses of the CASAHP under different CRs and partial-design ratios are conducted to obtain an optimal design that considers both energy savings and economy improvements. The results show that the optimal CR becomes higher in colder regions and with lower heat source temperatures. For a source temperature of 130 °C, the optimal CR values in all of the cities are within 2.0. For source temperatures from 100 to 130 °C, the maximum ESR is in the range of 17.7–29.2% in the studied cities. The efficiency improvement rate (EIR) caused by compression in a severe source condition can reach 10.0–20.0%. From the viewpoint of economy, the relative investment of CASAHP is reduced to 30–60% with a CR of 2.0–3.0. With a 2–6% sacrifice in ESR, the payback period can be reduced from 12–32 to 5–9 years using compression. Partial-design of the CASAHP can further reduce the payback period to 3–6 years with a partial-design ratio of 50% and a CR of 2.8. Additionally, CRs and partial-design ratios are designed comprehensively by seeking the maximum ESR for a given acceptable payback period

  20. Simulation of Evacuated Tube Collector and Storage of Hybrid Air-conditioning System

    Directory of Open Access Journals (Sweden)

    Mustafa Ahmed Abdulhussain

    2018-02-01

    Full Text Available The CFD transient simulation of superheating the refrigerant R410 through the heat exchange with the evacuated tube water heating system of the hybrid split air conditioner that is subjected to solar radiation of constant intensity with the contribution of fan accelerated air is performed by the ANSYS-CFX code. The comparison with experimental work showed a minimum percentage error 8% of the predicted refrigerant evaporative heat transfer with storage tank horizontal tubing. In addition, the results denoted high absorption rate for the evacuated tubes, reducing highly reversed heat transmission for the circulated water. 

  1. Thermodynamic model of a thermal storage air conditioning system with dynamic behavior

    International Nuclear Information System (INIS)

    Fleming, Evan; Wen, Shaoyi; Shi, Li; Silva, Alexandre K. da

    2013-01-01

    Highlights: • We developed an automotive thermal storage air conditioning system model. • The thermal storage unit utilizes phase change materials. • We use semi-analytic solution to the coupled phase change and forced convection. • We model the airside heat exchange using the NTU method. • The system model can incorporate dynamic inputs, e.g. variable inlet airflow. - Abstract: A thermodynamic model was developed to predict transient behavior of a thermal storage system, using phase change materials (PCMs), for a novel electric vehicle climate conditioning application. The main objectives of the paper are to consider the system’s dynamic behavior, such as a dynamic air flow rate into the vehicle’s cabin, and to characterize the transient heat transfer process between the thermal storage unit and the vehicle’s cabin, while still maintaining accurate solution to the complex phase change heat transfer. The system studied consists of a heat transfer fluid circulating between either of the on-board hot and cold thermal storage units, which we refer to as thermal batteries, and a liquid–air heat exchanger that provides heat exchange with the incoming air to the vehicle cabin. Each thermal battery is a shell-and-tube configuration where a heat transfer fluid flows through parallel tubes, which are surrounded by PCM within a larger shell. The system model incorporates computationally inexpensive semi-analytic solution to the conjugated laminar forced convection and phase change problem within the battery and accounts for airside heat exchange using the Number of Transfer Units (NTUs) method for the liquid–air heat exchanger. Using this approach, we are able to obtain an accurate solution to the complex heat transfer problem within the battery while also incorporating the impact of the airside heat transfer on the overall system performance. The implemented model was benchmarked against a numerical study for a melting process and against full system

  2. Controlled auto-ignition characteristics of methane-air mixture in a rapid intake compression and expansion machine

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Gyubaek; Jeong, Dongsoo [Engine Research Team, Eco-Machinery Research Division, Korea Institute of Machinery and Materials, 104 Sinseongno, Yuseong-gu, Daejeon 305-701 (Korea); Moon, Gunfeel [Department of Clean Environmental system, University of Science and Technology, 52 Eoeun-dong, Yuseong-gu, Daejeon (Korea); Bae, Choongsik [Engine Laboratory, Department of Mechanical Engineering, Korea Advanced Institute of Science and Technology, 373-1 GuSeong-Dong, Yuseong-Gu, Daejeon 305-701 (Korea)

    2010-10-15

    The characteristics of controlled auto-ignition (CAI) were investigated with a methane-air mixture and simulated residual gas, that represents internal exhaust gas recirculation (IEGR). Supply systems were additionally installed on the conventional rapid compression machine (RCM), and this modified machine - a rapid intake compression and expansion machine (RICEM) - was able to simulate an intake stroke for the evaluation of controlled auto-ignition with fuel-air mixture. The fuel-air mixture and the simulated residual gas were introduced separately into the combustion chamber through the spool valves. Various IEGR rates and temperatures of the IEGR gas were tested. The initial reaction and the development in controlled auto-ignition combustion were compared with spark-ignited combustion by visualization with a high-speed digital camera. Under the controlled auto-ignition operation, multi-point ignition and faster combustion were observed. With increasing the temperature of IEGR gas, the auto-ignition timing was advanced and burning duration was shortened. The higher rate of IEGR had the same effects on the combustion of the controlled auto-ignition. However, this trend was reversed with more than 47 per cent of IEGR. (author)

  3. Thermodynamic model of a thermal storage air conditioning system with dynamic behavior

    Energy Technology Data Exchange (ETDEWEB)

    Fleming, E; Wen, SY; Shi, L; da Silva, AK

    2013-12-01

    A thermodynamic model was developed to predict transient behavior of a thermal storage system, using phase change materials (PCMs), for a novel electric vehicle climate conditioning application. The main objectives of the paper are to consider the system's dynamic behavior, such as a dynamic air flow rate into the vehicle's cabin, and to characterize the transient heat transfer process between the thermal storage unit and the vehicle's cabin, while still maintaining accurate solution to the complex phase change heat transfer. The system studied consists of a heat transfer fluid circulating between either of the on-board hot and cold thermal storage units, which we refer to as thermal batteries, and a liquid-air heat exchanger that provides heat exchange with the incoming air to the vehicle cabin. Each thermal battery is a shell-and-tube configuration where a heat transfer fluid flows through parallel tubes, which are surrounded by PCM within a larger shell. The system model incorporates computationally inexpensive semianalytic solution to the conjugated laminar forced convection and phase change problem within the battery and accounts for airside heat exchange using the Number of Transfer Units (NTUs) method for the liquid-air heat exchanger. Using this approach, we are able to obtain an accurate solution to the complex heat transfer problem within the battery while also incorporating the impact of the airside heat transfer on the overall system performance. The implemented model was benchmarked against a numerical study for a melting process and against full system experimental data for solidification using paraffin wax as the PCM. Through modeling, we demonstrate the importance of capturing the airside heat exchange impact on system performance, and we investigate system response to dynamic operating conditions, e.g., air recirculation. (C) 2013 Elsevier Ltd. All rights reserved.

  4. Composite high-pressure vessels for hydrogen storage in mobile application. Pt. 1 / Light weight composite cylinders for compressed hydrogen. Pt. 2 - custom made hydrogen storage tanks and vessels

    Energy Technology Data Exchange (ETDEWEB)

    Rasche, C. [MCS Cylinder Systems GmbH, Dinslaken (Germany)

    2000-07-01

    Recent developments on fuel cell technology demonstrated the feasibility of propelling vehicles by converting fuel directly into electricity. Fuel cells conveniently use either compressed (CGH{sub 2}) or liquid hydrogen (LH{sub 2}) or methanol as the fuel source from a tank. Mobile storage of these fuelling will become an urgent need as this technology will come into series production expected for 2010. Due to the requirements on mobile hydrogen storage and the energy losses in the hydrogen-to-application-chain, a light-weight and energetic qualities and minimise ist bulky nature. Mobile storage of hydrogen can be realised either at high pressure values (> 20 MPa) or at deep temperatures (<-253 C). CGH{sub 2}: In the last few years, the introduction of natural gas driven vehicles has seen the development of compact mobile pressurised gas tanks in principle, this storage technique is also applicable for the compressed storage of hydrogen at filling pressures of > 20 MPa. LH{sub 2} : Storing hydrogen or natural gases in general in the liquid phase is accomplished either by applying a overpressure or keeping it below the phase transition temperature at ambient pressure in super insulated devices. (orig.)

  5. POTENTIAL FOR HYDROGEN BUILDUP IN HANFORD SEALED AIR FILLED NUCLEAR STORAGE VESSELS

    International Nuclear Information System (INIS)

    HEY BE

    2008-01-01

    This calculation is performed in accordance with HNF-PRO-8259, PHMC Calculation Preparation and Issue and addresses the question as to whether a flammable mixture of hydrogen gas can accumulate in a Hanford sealed nuclear storage vessel where the only source of hydrogen is the moisture in the air that initially filled the vessel Of specific concern is nuclear fuel inside IDENT 69-Gs, placed in Core Component Containers (CCCs) located inside Interim Storage Vaults (ISVs) at the Plutonium Finishing Plant (PFP) The CCCs are to be removed from the ISVs and placed inside a Hanford Unirradiated Fuel Package (HUFP) for transport and interim storage. The repackaging procedures mandated that no plastics were permitted, all labels and tape were to be removed and the pins to be clean and inspected Loading of the fuel into the CCC/ISV package was permitted only if it was not raining or snowing. This was to preclude the introduction of any water The purpose was to minimize the presence of any hydrogenous material inside the storage vessels. The scope of NFPA 69, 'Standard on Explosion Prevention Systems', precludes its applicability for this case. The reactor fuel pins are helium bonded. The non-fuel pins, such as the pellet stacks, are also helium bonded. The fuel pellets were sintered at temperatures that preclude any residual hydrogenous material. Hydrogen gas can be formed from neutron and gamma radiolysis of water vapor. The radiolysis reaction is quite complex involving several intermediate radicals, and competing recombination reactions. Hydrogen gas can also be formed through corrosion. This analysis takes a simplistic approach and assumes that all water vapor present in the storage vessel is decomposed into hydrogen gas. Although the analysis is needed to specifically address HUFP storage of nuclear fuel, it is equally applicable to any sealed fuel storage vessel under the assumptions listed

  6. Theoretical storage capacity for solar air pretreatment liquid collector/regenerator

    Energy Technology Data Exchange (ETDEWEB)

    Peng, Donggen; Zhang, Xiaosong; Yin, Yonggao [School of Energy and Environment, Southeast University, Nanjing 210096 (China)

    2008-08-15

    A new liquid regeneration equipment - solar air pretreatment collector/regenerator for liquid desiccant cooling system is put forward in this paper, which is preferable to solution regeneration in hot and moist climate in South China. The equipment can achieve liquid regeneration in lower temperature. When the solution and the air are in ''match'' state in collector/regenerator, a match air to salt mass ratio ASMR* is found by theoretical study in which there is the largest theoretical storage capacity SC{sub max}. At T{sub r} = 60{sup o}C and X{sub in} 2.33 kg/kg, theoretical calculation discovers when Y{sub in} drops from 29 to 14 g/kg, the SC{sub max} increase 50% compared with ASMR{sup *} being around 26-27. After two new concepts of the effective solution proportion (EPS) and the effective storage capacity (ESC) are defined, it is found by theoretical calculation that when ESP drops from 100% to 67%, ESC raises lowly, not drops and liquid outlet concentration C{sub str.sol} increases from 40% to 49% in which its increment totals to 90%. All these data explain fully that air pretreatment liquid regeneration equipment enables to improve the performance of liquid desiccant cooling system. (author)

  7. Performance of a Compression-ignition Engine with a Precombustion Chamber Having High-Velocity Air Flow

    Science.gov (United States)

    Spanogle, J A; Moore, C S

    1931-01-01

    Presented here are the results of performance tests made with a single-cylinder, four stroke cycle, compression-ignition engine. These tests were made on a precombustion chamber type of cylinder head designed to have air velocity and tangential air flow in both the chamber and cylinder. The performance was investigated for variable load and engine speed, type of fuel spray, valve opening pressure, injection period and, for the spherical chamber, position of the injection spray relative to the air flow. The pressure variations between the pear-shaped precombustion chamber and the cylinder for motoring and full load conditions were determined with a Farnboro electric indicator. The combustion chamber designs tested gave good mixing of a single compact fuel spray with the air, but did not control the ensuing combustion sufficiently. Relative to each other, the velocity of air flow was too high, the spray dispersion by injection too great, and the metering effect of the cylinder head passage insufficient. The correct relation of these factors is of the utmost importance for engine performance.

  8. Using Regression Analysis To Determine If Faculty Salaries Are Overly Compressed. AIR 1997 Annual Forum Paper.

    Science.gov (United States)

    Toutkoushian, Robert K.

    This paper proposes a five-step process by which to analyze whether the salary ratio between junior and senior college faculty exhibits salary compression, a term used to describe an unusually small differential between faculty with different levels of experience. The procedure utilizes commonly used statistical techniques (multiple regression…

  9. DNABIT Compress – Genome compression algorithm

    OpenAIRE

    Rajarajeswari, Pothuraju; Apparao, Allam

    2011-01-01

    Data compression is concerned with how information is organized in data. Efficient storage means removal of redundancy from the data being stored in the DNA molecule. Data compression algorithms remove redundancy and are used to understand biologically important molecules. We present a compression algorithm, “DNABIT Compress” for DNA sequences based on a novel algorithm of assigning binary bits for smaller segments of DNA bases to compress both repetitive and non repetitive DNA sequence. Our ...

  10. Analysis of a thermal energy storage system for air cooling–heating application through cylindrical tube

    International Nuclear Information System (INIS)

    Anisur, M.R.; Kibria, M.A.; Mahfuz, M.H.; Saidur, R.; Metselaar, I.H.S.C.

    2013-01-01

    Highlights: • Some design parameters of TES system for air cooling–heating application are studied. • Allowable inner radius and thickness of the tube for air flow should be considered. • Better COP is observed by decreasing the PCM container diameter. - Abstract: In order to reduce building energy consumption, thermal energy storage (TES) system has been explored as an alternative solution for air cooling–heating application. Different types of phase change materials (PCMs) along with the different geometries of TES system have been investigated for this application. In this work, a theoretical model was used to analyse the TES system for air cooling–heating application. The heat transfer phenomena in a phase change material (PCM) outside a double wall circular tube with heat transfer fluid (HTF) as air inside the tube were studied. Potassium fluoride tetrahydrate was used as a PCM for the TES system. Laminar forced convection with varying wall temperature was considered to analyse this system. Here, some important design parameters like inner radius and thickness of the tube for HTF flow were also investigated. It was found that an optimum inner radius and thickness of the tube should be considered to design a TES system. Since, significant change in outlet air temperature from the system was observed for reducing inner radius and increasing the thickness of the tube. The coefficients of performances (COPs) for cooling were found 8.79 and 7.20 for 15 mm and 25 mm inner radiuses of the PCM container respectively. Hence, the system can be optimized by reducing the volume of the PCM container. Furthermore, better COP was observed for higher inlet air temperature while the outlet air temperature was almost identical

  11. The application of liquid air energy storage for large scale long duration solutions to grid balancing

    Science.gov (United States)

    Brett, Gareth; Barnett, Matthew

    2014-12-01

    Liquid Air Energy Storage (LAES) provides large scale, long duration energy storage at the point of demand in the 5 MW/20 MWh to 100 MW/1,000 MWh range. LAES combines mature components from the industrial gas and electricity industries assembled in a novel process and is one of the few storage technologies that can be delivered at large scale, with no geographical constraints. The system uses no exotic materials or scarce resources and all major components have a proven lifetime of 25+ years. The system can also integrate low grade waste heat to increase power output. Founded in 2005, Highview Power Storage, is a UK based developer of LAES. The company has taken the concept from academic analysis, through laboratory testing, and in 2011 commissioned the world's first fully integrated system at pilot plant scale (300 kW/2.5 MWh) hosted at SSE's (Scottish & Southern Energy) 80 MW Biomass Plant in Greater London which was partly funded by a Department of Energy and Climate Change (DECC) grant. Highview is now working with commercial customers to deploy multi MW commercial reference plants in the UK and abroad.

  12. Experimental study on split air conditioner with new hybrid equipment of energy storage and water heater all year round

    International Nuclear Information System (INIS)

    Wang Shaowei; Liu Zhenyan; Li Yuan; Zhao Keke; Wang Zhigang

    2005-01-01

    This paper presents a split air conditioner with a new hybrid equipment of energy storage and water heater all year round (ACWES). The authors made a special design on the storage tank to adjust the refrigerant capacity in the storage coils under different functions, instead of adding an accumulator to the system. An ACWES prototype, rebuilt from an original split air conditioner, has been finished, and experimental study of the operation processes of the prototype was done from which some important conclusions and suggestions have been made, which were helpful in the primary design and improvement of an ACWES system for potential users

  13. Enhanced reversibility and durability of a solid oxide Fe-air redox battery by carbothermic reaction derived energy storage materials.

    Science.gov (United States)

    Zhao, Xuan; Li, Xue; Gong, Yunhui; Huang, Kevin

    2014-01-18

    The recently developed solid oxide metal-air redox battery is a new technology capable of high-rate chemistry. Here we report that the performance, reversibility and stability of a solid oxide iron-air redox battery can be significantly improved by nanostructuring energy storage materials from a carbothermic reaction.

  14. THE USE OF A FACTORIAL DESIGN TO EVALUATE THE PHYSICAL STABILITY OF TABLETS PREPARED BY DIRECT COMPRESSION .2. SELECTION OF EXCIPIENTS SUITABLE FOR USE UNDER TROPICAL STORAGE-CONDITIONS

    NARCIS (Netherlands)

    BOS, CE; BOLHUIS, GK; LERK, CF; DEBOER, JH; DUINEVELD, CAA; SMILDE, AK; DOORNBOS, DA

    1991-01-01

    A factorial design has been used to study the influence of disintegrant concentration, storage temperature and relative humidity upon storage on the physical stability of tablets prepared by direct compression. Tablets prepared from a binary mixture of a filler-binder and a disintegrant were stored

  15. Thermal energy storages analysis for high temperature in air solar systems

    International Nuclear Information System (INIS)

    Andreozzi, Assunta; Buonomo, Bernardo; Manca, Oronzio; Tamburrino, Salvatore

    2014-01-01

    In this paper a high temperature thermal storage in a honeycomb solid matrix is numerically investigated and a parametric analysis is accomplished. In the formulation of the model it is assumed that the system geometry is cylindrical, the fluid and the solid thermo physical properties are temperature independent and radiative heat transfer is taken into account whereas the effect of gravity is neglected. Air is employed as working fluid and the solid material is cordierite. The evaluation of the fluid dynamic and thermal behaviors is accomplished assuming the honeycomb as a porous medium. The Brinkman–Forchheimer–extended Darcy model is used in the governing equations and the local thermal non equilibrium is assumed. The commercial CFD Fluent code is used to solve the governing equations in transient regime. Numerical simulations are carried out with storage medium for different mass flow rates of the working fluid and different porosity values. Results in terms of temperature profiles, temperatures fields and stored thermal energy as function of time are presented. The effects of storage medium, different porosity values and mass flow rate on stored thermal energy and storage time are shown. - Highlights: • HTTES in a honeycomb solid matrix is numerically investigated. • The numerical analysis is carried out assuming the honeycomb as a porous medium. • The Brinkman–Forchheimer–extended Darcy model is used in the governing equations. • Results are carried out for different mass flow rates and porosity values. • The main effect is due to the porosity which set the thermal energy storage value

  16. An Invitro Comparative Evaluation of Compressive Strength and Antibacterial Activity of Conventional GIC and Hydroxyapatite Reinforced GIC in Different Storage Media.

    Science.gov (United States)

    Bali, Praveen; Prabhakar, Attiguppe Ramasetty; Basappa, Nadig

    2015-07-01

    GIC is the most commonly used restorative material in pediatric dentistry since it has got various advantages like fluoride release, anticariogenic property and chemical adhesion to tooth but a major disadvantage is its contraindication in posterior teeth because of poor mechanical properties. The purpose of this study is a modest attempt to explore the influence of the addition of 8% hydroxyapatite to conventional GIC on its compressive strength when immersed in different storage media and antibacterial activity. One hundred and twenty six pellets of the specific dimension of 6 x 4 mm were prepared and divided into 6 groups and were immersed in deionized water, artificial saliva, lactic acid solution respectively for three hours everyday over 30 days test period. The compressive strength was measured by using a universal testing machine (AG-50kNG) at cross head of 1mm(2)/min and strength was determined after 1 day, 7 days, 30 days respectively and the antibacterial activity evaluated against Streptococcus mutans strain in brain heart infusion broth using serial dilution method. Group wise comparisons were made by one-way ANOVA followed by post-hoc Tukey's test, Intergroup comparison was done with Mann-Whitney test. GIC±HAp showed significantly greater antibacterial activity against Streptococcus mutans when compared to GIC group. There was no statistically significant change in the compressive strength among the groups except for group 3 and group 6 when immersed in lactic acid had shown significant difference at the end of 24 hours. The addition of 8% hydroxyapatite to GIC showed marked increased in the antibacterial activity of the conventional GIC against caries initiating organism without much increase in the compressive strength of the GIC when immersed in the different storage media.

  17. Performance of a new solar air heater with packed-bed latent storage energy for nocturnal use

    International Nuclear Information System (INIS)

    Bouadila, Salwa; Kooli, Sami; Lazaar, Mariem; Skouri, Safa; Farhat, Abdelhamid

    2013-01-01

    Highlights: • A new solar air heater collector using a phase change material. • Experimental study of the new solar air heater collector with latent storage. • Energy and exergy analysis of the solar heater with latent storage collector. • Nocturnal use of solar air heater collector. - Abstract: An experimental study was conducted to evaluate the thermal performance of a new solar air heater collector using a packed bed of spherical capsules with a latent heat storage system. Using both first and second law of thermodynamics, the energetic and exegetic daily efficiencies were calculated in Closed/Opened and Opened cycle mode. The solar energy was stored in the packed bed through the diurnal period and extracted at night. The experimentally obtained results are used to analyze the performance of the system, based on temperature distribution in different localization of the collectors. The daily energy efficiency varied between 32% and 45%. While the daily exergy efficiency varied between 13% and 25%

  18. DISCHARGE OXIDE STORAGE CAPACITY AND VOLTAGE LOSS IN LI-AIR BATTERY

    International Nuclear Information System (INIS)

    Wang, Yun; Wang, Zhe; Yuan, Hao; Li, Tianqi

    2015-01-01

    Air cathodes, where oxygen reacts with Li ions and electrons with discharge oxide stored in their pore structure, are often considered as the most challenging component in nonaqueous Lithium-air batteries. In non-aqueous electrolytes, discharge oxides are usually insoluble and hence precipitate at local reaction site, raising the oxygen transport resistance in the pore network. Due to their low electric conductivity, their presence causes electrode passivation. This study aims to investigate the air cathode’s performance through analytically obtaining oxygen profiles, modeling electrode passivation, evaluating the transport polarization raised by discharge oxide precipitate, and developing analytical formulas for insoluble Li oxides storage capacity. The variations of cathode quantities, including oxygen content and temperature, are evaluated and related to a single dimensionless parameter — the Damköhler Number (Da). An approximate model is developed to predict discharge voltage loss, along with validation against two sets of experimental data. Air cathode properties, including tortuosity, surface coverage factor and the Da number, and their effects on the cathode’s capacity of storing Li oxides are formulated and discussed.

  19. Optimisation of compressed-air supply for control purposes at Valorec Services AG; Optimierung der Steuerluft - Versorgung bei der Valorec Services AG

    Energy Technology Data Exchange (ETDEWEB)

    Dott, R.; Afjei, T.

    2005-07-01

    This final report for the Swiss Federal Office of Energy (SFOE) presents the results of a project that looked at the possibilities of optimising the supply of compressed air provided around the clock by four compressor systems of varying ages in a facility in Basle, Switzerland. The initial situation is analysed and the potential for making savings is estimated. Various possibilities for improvement are considered including changing the topology of the compressed-air network, the replacement of certain compressors and a new control system. Appropriate measures are proposed and compared with new installations.

  20. Modernisation of compressed-air production in the heating power station of a university hospital; Modernisierung der Drucklufterzeugung im Heizkraftwerk eines Universitaetsklinikums

    Energy Technology Data Exchange (ETDEWEB)

    Glaser, H. [Landesregierung Schleswig-Holstein (Germany). Reaktorsciherheit

    2006-07-15

    Compressed air required for the power plant systems (flue gas desulphurisation system, high-pressure superheated steam boilers, gas turbine) and compressed air systems (pneumatic drives and control systems of the technical facilities) of Freiburg university hospital is produced in a large compressor station constructed in 1987, at the same time as the flue gas desulphurisation system of the combined heat and power station. The compressor station consisted of two uncontrolled screw compressors and was inadequate in terms of control, servicing and energy consumption cost. (orig.)

  1. A work procedure of utilising PCMs as thermal storage systems based on air-TES systems

    International Nuclear Information System (INIS)

    Iten, M.; Liu, S.

    2014-01-01

    Highlights: • A procedure to design effective thermal energy storage (TES) system. • A guidance for the selection of the working material (PCM) and the heat exchanger development. • Suggestions for heat transfer enhancement techniques for the air-TES system. • Mathematical, computational and experimental methods optimising the air-TES system. - Abstract: The paper seeks to offer a procedure to design an effective short term thermal energy storage (TES) system using phase change materials. The methodology focus on two main aspects: the selection of the working material and the heat exchanger development. The selection of the appropriate PCMs is one of the main keys for any TES therefore their classifications, properties, advantages and disadvantages need to be investigated. Due to the intensive researches using this kind of materials in the recent years, there are a range of commercial PCMs available and supplied by different companies. However, all types of PCM present their specific problems and therefore requirements are defined in order to select the most suitable PCMs. The other main key when designing TES is related to the heat exchanger formed by the PCM and the cold/hot heat sources. For this step, the choice of the appropriate container to encapsulate the PCM and the heat transfer enhancement techniques are analysed. Distinct methodologies such as experimental and numerical study methods and modelling software tools are presented to analyse the thermal energy performance of the system and achieve the optimal design of the TES system

  2. Ventilation and air conditioning system in waste treatment and storage facilities

    International Nuclear Information System (INIS)

    Kinoshita, Hirotsugu; Sugawara, Kazushige.

    1987-01-01

    So far, the measures concerning the facilities for treating and storing radioactive wastes in nuclear fuel cycle in Japan were in the state which cannot be said to be sufficient. In order to cope with this situation, electric power companies constructed and operated radioactive waste concentration and volume reduction facilities, solid waste storing facilities for drums, high level solid waste storing facilities, spent fuel cask preserving facilities and so on successively in the premises of nuclear power stations, and for the wastes expected in future, the research and the construction plan of the facilities for treating and storing low, medium and high level wastes have been advanced. The ventilation and air conditioning system for these facilities is the important auxiliary system which has the mission of maintaining safe and pleasant environment in the facilities and lowering as far as possible the release of radioactive substances to outside. The outline of waste treatment and storage facilities is explained. The design condition, ventilation and air conditioning method, the features of respective waste treatment and storage facilities, and the problems for the future are described. Hereafter, mechanical ventilation system continues to be the main system, and filters become waste, while the exchange of filters is accompanied by the radiation exposure of workers. (Kako, I.)

  3. Testing Open-Air Storage of Stumps to Provide Clean Biomass for Energy Production

    Directory of Open Access Journals (Sweden)

    Luigi Pari

    2017-10-01

    Full Text Available When orchards reach the end of the productive cycle, the stumps removal becomes a mandatory operation to allow new soil preparation and to establish new cultivations. The exploitation of the removed stump biomass seems a valuable option, especially in the growing energy market of the biofuels; however, the scarce quality of the material obtained after the extraction compromises its marketability, making this product a costly waste to be disposed. In this regard, the identification of affordable strategies for the extraction and the cleaning of the material will be crucial in order to provide to plantation owners the chance to sell the biomass and offset the extraction costs. Mechanical extraction and cleaning technologies have been already tested on forest stumps, but these systems work on the singular piece and would be inefficient in the conditions of an intensive orchard, where stumps are small and numerous. The objective of this study was to test the possibility to exploit a natural stumps cleaning system through open-air storage. The tested stumps were obtained from two different vineyards, extracted with an innovative stump puller specifically designed for continuous stump removal in intensively-planted orchards. The effects of weathering were evaluated to determine the fuel quality immediately after the extraction and after a storage period of six months with respect to moisture content, ash content, and heating value. Results indicated interesting storage performance, showing also different dynamics depending on the stumps utilized.

  4. [Management of penile trauma from compressed air gun in a child].

    Science.gov (United States)

    Girón-Vallejo, O; Zambudio, G; Ruiz-Pruneda, R; Hernindez, J P; Ruiz-Jiménez, J I

    2011-01-01

    We report on a 6-year old child with a penile injury resulting in the inclusion of a pellet in the cavernous body, by a fortuitous shot. Conservative approach with elective extraction of the bullet and cavernous body repair led to a satisfactory result, in better anatomic conditions. The patient did not have any perioperative complication. Accidents by air weapons are particularly important in children, because these weapons are erroneously considered as toys. Air gun injuries to head, neck and thorax have been often published, but these injuries are rare in the chidren genitourinary area.

  5. Homemade Firearm Suicide With Dumbbell Pipe Triggering by an Air-Compressed Gun: Case Report and Review of Literature.

    Science.gov (United States)

    Le Garff, Erwan; Delannoy, Yann; Mesli, Vadim; Berthezene, Jean Marie; Morbidelli, Philippe; Hédouin, Valéry

    2015-12-01

    Firearm suicides are frequent and well described in the forensic literature, particularly in Europe and the United States. However, the use of homemade and improvised firearms is less well described. The present case reports a suicide with an original improvised gun created using an air-compressed pellet gun and a dumbbell pipe. The aims of this study were to describe the scene, the external examination of the corpse, the body scan, and the autopsy; to understand the mechanism of death; and to compare the results with a review of the forensic literature to highlight the epidemiology of homemade firearm use, the tools used for homemade and improvised firearms in suicides versus homicides, and the manners in which homemade firearms are used (homicide or suicide, particularly in complex suicide cases).

  6. Study of a vapor-compression air-conditioning system for jetliners

    Energy Technology Data Exchange (ETDEWEB)

    Roeyttae, P.

    2009-07-01

    Most modern passenger aeroplanes use air cycle cooling. A high-speed air cycle is a reliable and light option, but not very efficient. This thesis presents research work done to design a novel vapour cooling cycle for aeroplanes. Due to advancements in high-speed permanent magnet motors, the vapour cycle is seen as a competitive option for the air cycle in aeroplanes. The aerospace industry placews tighter demands on the weight, reliability and environmental effects of the machinery than those met by conventional chillers, and thus modifications to conventional design are needed. The thesis is divided into four parts: the initial screening of the working fluid, 1-D design and performance values of the compressor, 1-D off-design value predictions of the compressor and the 3-D design of the compressor. The R24fa was selected as the working fluid based the study. The off-design range of the compressor was predicted to be wide and suitable for the application. The air-conditioning system developed is considerably smaller than previous designs using centrifugal compressors. (orig.)

  7. Overview of direct air free cooling and thermal energy storage potential energy savings in data centres

    International Nuclear Information System (INIS)

    Oró, Eduard; Depoorter, Victor; Pflugradt, Noah; Salom, Jaume

    2015-01-01

    In the last years the total energy demand of data centres has experienced a dramatic increase which is expected to continue. This is why data centres industry and researchers are working on implementing energy efficiency measures and integrating renewable energy to overcome energy dependence and to reduce operational costs and CO 2 emissions. The cooling system of these unique infrastructures can account for 40% of the total energy consumption. To reduce the energy consumption, free cooling strategies are used more and more, but so far there has been little research about the potential of thermal energy storage (TES) solutions to match energy demand and energy availability. Hence, this work intends to provide an overview of the potential of the integration of direct air free cooling strategy and TES systems into data centres located at different European locations. For each location, the benefit of using direct air free cooling is evaluated energetically and economically for a data centre of 1250 kW. The use of direct air free cooling is shown to be feasible. This does not apply the TES systems by itself. But when using TES in combination with an off-peak electricity tariff the operational cooling cost can be drastically reduced. - Highlights: • The total annual hours for direct air free cooling in data centres are calculated. • The potential of TES integration in data centres is evaluated. • The implementation of TES to store the ambient air cold is not recommended. • TES is feasible if combined with redundant chillers and off-peak electricity price. • The cooling electricity cost is being reduced up to 51%, depending on the location

  8. A micro-fabricated hydrogen storage module with sub-atmospheric activation and durability in air exposure

    Energy Technology Data Exchange (ETDEWEB)

    Shan, Xi; Payer, Joe H. [Corrosion and Reliability Engineering, Department of Chemical and Biomolecular Engineering, University of Akron, 302 Buchtel Common, Akron, OH 44325 (United States); Wainright, Jesse S.; Dudik, Laurie [Department of Chemical Engineering, Case Western Reserve University, Cleveland, OH 44106 (United States)

    2011-01-15

    The objective of this work was to develop a hydrogen storage module for onboard electrical power sources suitable for use in micro-power systems and micro-electro-mechanical systems (MEMS). Hydrogen storage materials were developed as thin-film inks to be compatible with an integrated manufacturing process. Important design aspects were (a) ready activation at sub-atmospheric hydrogen pressure and room temperature and (b) durability, i.e. capable of hundreds of absorption/desorption cycles and resistance to deactivation on exposure to air. Inks with palladium-treated intermetallic hydrogen storage alloys were developed and are shown here to be compatible with a thin-film micro-fabrication process. These hydrogen storage modules absorb hydrogen readily at atmospheric pressure, and the absorption/desorption rates remained fast even after the ink was exposed to air for 47 weeks. (author)

  9. Wind turbine storage systems

    International Nuclear Information System (INIS)

    Ibrahim, H.; Ilinca, A.; Perron, J.

    2005-01-01

    Electric power is often produced in locations far from the point of utilization which creates a challenge in stabilizing power grids, particularly since electricity cannot be stored. The production of decentralized electricity by renewable energy sources offers a greater security of supply while protecting the environment. Wind power holds the greatest promise in terms of environmental protection, competitiveness and possible applications. It is known that wind energy production is not always in phase with power needs because of the uncertainty of wind. For that reason, energy storage is the key for the widespread integration of wind energy into the power grids. This paper proposed various energy storage methods that can be used in combination with decentralized wind energy production where an imbalance exists between electricity production and consumption. Energy storage can play an essential role in bringing value to wind energy, particularly if electricity is to be delivered during peak hours. Various types of energy storage are already in use or are being developed. This paper identified the main characteristics of various electricity storage techniques and their applications. They include stationary or embarked storage for long or short term applications. A comparison of characteristics made it possible to determine which types of electricity storage are best suited for wind energy. These include gravity energy; thermal energy; compressed air energy; coupled storage with natural gas; coupled storage with liquefied gas; hydrogen storage for fuel cells; chemical energy storage; storage in REDOX batteries; storage by superconductive inductance; storage in supercondensers; and, storage as kinetic energy. 21 refs., 21 figs

  10. Design of a compressed air modulator to be used in comprehensive multidimensional gas chromatography and its application in the determination of pesticide residues in grapes

    NARCIS (Netherlands)

    Pizzutti, I.R.; Vreuls, J.J.; Kok, A; Roehrs, R.; Martel, S.; Friggi, C.A.; Zanella, R.

    2009-01-01

    In this study, a new modulator that is simple, robust and presents low operation costs, was developed. This modulator uses compressed air to cool two small portions in the first centimeters of the second chromatographic column of a comprehensive multidimensional gas chromatography (GC × GC) system.

  11. A comparative study of compression-expansion type dehumidification systems to achieve low dew point air

    International Nuclear Information System (INIS)

    Moon, Choon; Bansal, Pradeep

    2009-01-01

    This paper presents a theoretical feasibility study of three dehumidification systems to achieve air with dew points down to (-) 40 deg. C. The systems consist of compressors, heat exchangers, expanders and heaters. A thermodynamic model has been developed of the systems to study the effect of the compressor, expander, and heat recovery heat exchanger efficiency as a function of pressure ratio, net required work, quantity of condensed moisture, and system outlet dew point temperature. The analysis has revealed that the selection of a heat recovery heat exchanger is critical for an efficient dehumidification system, where compressor efficiency has the dominant effect on power consumption.

  12. A computational study on the performance of a solar air-conditioning system with a partitioned storage tank

    International Nuclear Information System (INIS)

    Li, Z.F.; Sumathy, K.

    2003-01-01

    This paper reports the performance of a modified solar powered air-conditioning system, which is integrated with a partitioned storage tank. In addition, the effect of two main parameters that influence the system performance is presented and discussed. The study shows that by partitioning the storage tank, the solar cooling effect can be realized much earlier and could attain a total solar cooling COP of 12% higher compared to the conventional whole-tank mode. Simulation results also indicate that there exists an optimum ratio of storage tank volume over collector area

  13. Changes in Ultrastructure and Sensory Characteristics on Electro-magnetic and Air Blast Freezing of Beef during Frozen Storage

    Science.gov (United States)

    2015-01-01

    The ultrastructure in the beef muscle of the electro-magnetic resonance and air blast freezing during the frozen storage, and the changes in the quality characteristics after thawing were evaluated. The size of ice crystal was small and evenly formed in the initial freezing period, and it showed that the size was increased as the storage period was elapsed (pfreezing showed the size of ice crystal with a lower rate of increase than the air blast freezing during the frozen storage. The thawing loss of beef stored by the electro-magnetic resonance freezing was significantly lower than the air blast freezing during frozen storage (pfreezing was higher than the air blast on 8 month (pfreezing did not show the difference until 4 months, and it showed higher acceptability in comparison with the beef stored by the air blast freezing. Thus, it is considered that the freezing method has an effect on the change in the ultrastructure and quality characteristics of the beef. PMID:26761797

  14. Use of backboard and deflation improve quality of chest compression when cardiopulmonary resuscitation is performed on a typical air inflated mattress configuration.

    Science.gov (United States)

    Oh, Jaehoon; Kang, Hyunggoo; Chee, Youngjoon; Lim, Taeho; Song, Yeongtak; Cho, Youngsuk; Je, Sangmo

    2013-02-01

    No study has examined the effectiveness of backboards and air deflation for achieving adequate chest compression (CC) depth on air mattresses with the typical configurations seen in intensive care units. To determine this efficacy, we measured mattress compression depth (MCD, mm) on these surfaces using dual accelerometers. Eight cardiopulmonary resuscitation providers performed CCs on manikins lying on 4 different surfaces using a visual feedback system. The surfaces were as follows: A, a bed frame; B, a deflated air mattress placed on top of a foam mattress laid on a bed frame; C, a typical air mattress configuration with an inflated air mattress placed on a foam mattress laid on a bed frame; and D, C with a backboard. Deflation of the air mattress decreased MCD significantly (B; 14.74 ± 1.36 vs C; 30.16 ± 3.96, P deflation of the air mattress decreased MCD more than use of a backboard (B; 14.74 ± 1.36 vs D; 25.46 ± 2.89, P = 0.002). The use of a both a backboard and a deflated air mattress in this configuration reduces MCD and thus helps achieve accurate CC depth during cardiopulmonary resuscitation.

  15. Development of salt hydrate eutectics as latent heat storage for air conditioning and cooling

    International Nuclear Information System (INIS)

    Efimova, Anastasia; Pinnau, Sebastian; Mischke, Matthias; Breitkopf, Cornelia; Ruck, Michael; Schmidt, Peer

    2014-01-01

    Graphical abstract: - Highlights: • Inorganic salt hydrates. • Latent heat thermal energy storage. • Thermal behavior of melting and crystallization. • Cycling stability. • Nucleation. - Abstract: Sustainable air conditioning systems require heat reservoirs that operate between 4 and 20 °C. A systematic search for binary and ternary eutectics of inorganic salts and salt hydrates with melting temperatures in this temperature regime and with high enthalpies of fusion has been performed by means of differential scanning calorimetry (DSC). Promising results were obtained for the pseudo-ternary system Zn(NO 3 ) 2 ·6H 2 O, Mn(NO 3 ) 2 ·4H 2 O, and KNO 3 with the melting temperature range 18–21 °C and the enthalpy of fusion of about 110 kJ kg −1 . Suitable nucleating and thickening agents have been found and tested to prevent the mixture from supercooling and phase separation

  16. Evaluation Framework and Analyses for Thermal Energy Storage Integrated with Packaged Air Conditioning

    Energy Technology Data Exchange (ETDEWEB)

    Kung, F.; Deru, M.; Bonnema, E.

    2013-10-01

    Few third-party guidance documents or tools are available for evaluating thermal energy storage (TES) integrated with packaged air conditioning (AC), as this type of TES is relatively new compared to TES integrated with chillers or hot water systems. To address this gap, researchers at the National Renewable Energy Laboratory conducted a project to improve the ability of potential technology adopters to evaluate TES technologies. Major project outcomes included: development of an evaluation framework to describe key metrics, methodologies, and issues to consider when assessing the performance of TES systems integrated with packaged AC; application of multiple concepts from the evaluation framework to analyze performance data from four demonstration sites; and production of a new simulation capability that enables modeling of TES integrated with packaged AC in EnergyPlus. This report includes the evaluation framework and analysis results from the project.

  17. An experimental investigation of performance of a double pass solar air heater with thermal storage medium

    Directory of Open Access Journals (Sweden)

    Ali Hafiz Muhammad

    2015-01-01

    Full Text Available The performance of a double pass solar air heater was experimentally investigated using four different configurations. First configuration contained only absorber plate whereas copper tubes filled with thermal storage medium (paraffin wax were added on the absorber plate in the second configuration. Aluminum and steel rods as thermal enhancer were inserted in the middle of paraffin wax of each tube for configurations three and four respectively. Second configuration provided useful heat for about 1.5 hours after the sunset compared to first configuration. Configurations three and four provided useful heat for about 2 hours after the sunset. The maximum efficiency of about 96% was achieved using configuration three (i.e. using Aluminum rods in the middle of copper tubes filled with paraffin wax.

  18. Changes in ocean circulation and carbon storage are decoupled from air-sea CO2 fluxes

    OpenAIRE

    A. Gnanadesikan; I. Marinov

    2010-01-01

    The spatial distribution of the air-sea flux of carbon dioxide is a poor indicator of the underlying ocean circulation and of ocean carbon storage. The weak dependence on circulation arises because mixing-driven changes in solubility-driven and biologically-driven air-sea fluxes largely cancel out. This cancellation occurs because mixing driven increases in the poleward residual mean circulation results in more transport of both remineralized nutrients and heat from low to high latitudes. By ...

  19. Impact of Storage Technologies upon Power System Losses

    Directory of Open Access Journals (Sweden)

    DULAU Lucian Ioan

    2015-05-01

    Full Text Available The paper describes the main characteristics of storage technologies. The most important storage technologies are the batteries, hydrogen, pumped hydro, flywheels, compressed air, super-capacitors and superconducting magnetic devices. The storage technologies can be classified based on the function principle into electrochemical, mechanical and electromagnetic devices. The storage systems can also be classified based on their capacity to store power into short and long term devices. A power flow analysis is performed for the situation with and without a storage unit. The storage unit is inserted into the IEEE 14 bus test system.

  20. CFD Analysis on the Passive Heat Removal by Helium and Air in the Canister of Spent Fuel Dry Storage System

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Do Young; Jeong, Ui Ju; Kim, Sung Joong [Hanyang University, Seoul (Korea, Republic of)

    2016-05-15

    In the current commercial design, the canister of the dry storage system is mainly backfilled with helium gas. Helium gas shows very conductive behavior due to high thermal conductivity and small density change with temperature. However, other gases such as air, argon, or nitrogen are expected to show effective convective behavior. Thus these are also considered as candidates for the backfill gas to provide effective coolability. In this study, to compare the dominant cooling mechanism and effectiveness of cooling between helium gas and air, a computational fluid dynamics (CFD) analysis for the canister of spent fuel dry storage system with backfill gas of helium and air is carried out. In this study, CFD simulations for the helium and air backfilled gas for dry storage system canister were carried out using ANSYS FLUENT code. For the comparison work, two backfilled fluids were modeled with same initial and boundary conditions. The observed major difference can be summarized as follows. - The simulation results showed the difference in dominant heat removal mechanism. Conduction for helium, and convection for air considering Reynolds number distribution. - The temperature gradient inside the fuel assembly showed that in case of air, more effective heat mixing occurred compared to helium.

  1. DNABIT Compress – Genome compression algorithm

    Science.gov (United States)

    Rajarajeswari, Pothuraju; Apparao, Allam

    2011-01-01

    Data compression is concerned with how information is organized in data. Efficient storage means removal of redundancy from the data being stored in the DNA molecule. Data compression algorithms remove redundancy and are used to understand biologically important molecules. We present a compression algorithm, “DNABIT Compress” for DNA sequences based on a novel algorithm of assigning binary bits for smaller segments of DNA bases to compress both repetitive and non repetitive DNA sequence. Our proposed algorithm achieves the best compression ratio for DNA sequences for larger genome. Significantly better compression results show that “DNABIT Compress” algorithm is the best among the remaining compression algorithms. While achieving the best compression ratios for DNA sequences (Genomes),our new DNABIT Compress algorithm significantly improves the running time of all previous DNA compression programs. Assigning binary bits (Unique BIT CODE) for (Exact Repeats, Reverse Repeats) fragments of DNA sequence is also a unique concept introduced in this algorithm for the first time in DNA compression. This proposed new algorithm could achieve the best compression ratio as much as 1.58 bits/bases where the existing best methods could not achieve a ratio less than 1.72 bits/bases. PMID:21383923

  2. Measurement of air quality within storage domes in technical area 54, areas G and L

    International Nuclear Information System (INIS)

    Anderson, E.

    1994-01-01

    The concentrations of volatile organic compounds (VOCs) and tritium inside of storage domes at TA-54 were measured to assess worker exposure and support the Area G site characterization, including the Radioactive Air Emissions Management (RAEM) program. Samples were collected at 2-3 locations within Domes 48, 49, and 153 on up to six days during the summer of 1994. Samples were collected to evaluate three scenarios: (1) normal working activities with the domes open; (2) after domes were closed overnight; and (3) after domes were closed for three days. Eight-hour integrated samples were collected and analyzed in Radian's Austin laboratories. Tritium activities from 17.1 to 69,900 pCi/m 3 were measured. About two dozen individual VOCs were identified in each sample, but most of the concentration levels were very low (e.g.; 20%) than when the domes were closed only overnight. The data were used to generate estimated annual dome emission rates of 0.3 Ci/yr of tritium and less than 100 lbs/yr of VOCs. The measured VOC concentrations were collected during the warmest months of the year and therefore should represent worst-case air impacts

  3. The stationary storage of energy. Available technologies and CEA researches

    International Nuclear Information System (INIS)

    2012-01-01

    After a discussion of the main challenges related to the stationary storage of energy, this publication proposes an overview of the different available technologies: plant for transfer of energy by pumping, compressed air, energy flywheels, hydrogen, lithium-ion battery, redox-flow battery, thermal storage by sensitive heat, thermal-chemical storage coupled to a thermal solar system, thermal storage by phase change, superconductive inductance storage, super-capacitors. It discusses the criteria of choice of storage technology, either for electric energy storage or for heat storage. It proposes an overview of researches performed within the CEA on storage systems: electrochemical, thermal, and hydrogen-based storages. The final chapter addresses current fundamental researches on storage in the field of lithium-ion batteries, hydrogen as a fuel, and thermoelectricity

  4. Energy efficient hybrid nanocomposite-based cool thermal storage air conditioning system for sustainable buildings

    International Nuclear Information System (INIS)

    Parameshwaran, R.; Kalaiselvam, S.

    2013-01-01

    The quest towards energy conservative building design is increasingly popular in recent years, which has triggered greater interests in developing energy efficient systems for space cooling in buildings. In this work, energy efficient silver–titania HiTES (hybrid nanocomposites-based cool thermal energy storage) system combined with building A/C (air conditioning) system was experimentally investigated for summer and winter design conditions. HiNPCM (hybrid nanocomposite particles embedded PCM) used as the heat storage material has exhibited 7.3–58.4% of improved thermal conductivity than at its purest state. The complete freezing time for HiNPCM was reduced by 15% which was attributed to its improved thermophysical characteristics. Experimental results suggest that the effective energy redistribution capability of HiTES system has contributed for reduction in the chiller nominal cooling capacity by 46.3% and 39.6% respectively, under part load and on-peak load operating conditions. The HiTES A/C system achieved 27.3% and 32.5% of on-peak energy savings potential in summer and winter respectively compared to the conventional A/C system. For the same operating conditions, this system yield 8.3%, 12.2% and 7.2% and 10.2% of per day average and yearly energy conservation respectively. This system can be applied for year-round space conditioning application without sacrificing energy efficiency in buildings. - Highlights: • Energy storage is acquired by HiTES (hybrid nanocomposites-thermal storage) system. • Thermal conductivity of HiNPCM (hybrid nanocomposites-PCM) was improved by 58.4%. • Freezing time of HiNPCM was reduced by 15% that enabled improved energy efficiency. • Chiller nominal capacity was reduced by 46.3% and 39.6% in on-peak and part load respectively. • HiTES A/C system achieved appreciable energy savings in the range of 8.3–12.2%

  5. Air temperature optimisation for humidity-controlled cold storage of the predatory mites Neoseiulus californicus and Phytoseiulus persimilis (Acari: Phytoseiidae).

    Science.gov (United States)

    Ghazy, Noureldin Abuelfadl; Suzuki, Takeshi; Amano, Hiroshi; Ohyama, Katsumi

    2014-03-01

    Humidity-controlled cold storage, in which the water vapour pressure is saturated, can prolong the survival of the predatory mites Neoseiulus californicus (McGregor) and Phytoseiulus persimilis Athias-Henriot (Acari: Phytoseiidae). However, information on the optimum air temperature for long-term storage by this method is limited. The authors evaluated the survival of mated adult females of N. californicus and P. persimilis at 5.0, 7.5, 10.0 and 12.5 °C under saturated water vapour condition (vapour pressure deficit 0.0 kPa). N. californicus showed a longer survival time than P. persimilis at all the air temperatures. The longest mean survival time of N. californicus was 11 weeks at 7.5 °C, whereas that of P. persimilis was 8 weeks at 5.0 °C. After storage at 7.5 °C for 8 weeks, no negative effect on post-storage oviposition was observed in N. californicus, whereas the oviposition of P. persimilis stored at 5.0 °C for 8 weeks was significantly reduced. The interspecific variation in the response of these predators to low air temperature might be attributed to their natural habitat and energy requirements. These results may be useful for the long-term storage of these predators, which is required for cost-effective biological control. © 2013 Society of Chemical Industry.

  6. Sponge divers of the Aegean and medical consequences of risky compressed-air dive profiles.

    Science.gov (United States)

    Toklu, Akin Savas; Cimsit, Maide

    2009-04-01

    Historically, Turkey once had a substantial number of professional sponge divers, a population known for a relatively high incidence of diving-related conditions such as decompression sickness (DCS) and dysbaric osteonecrosis (DON). Sponge diving ended in the mid-1980s when nearly all of the sponges in the Aegean and Mediterranean Seas contracted a bacterial disease and the occupation became unprofitable. We reviewed the records of Turkish sponge divers for information on their level of knowledge, diving equipment, dive profiles, and occupational health problems. Information was collected by: 1) interviewing former sponge divers near Bodrum, where most of them had settled; 2) reviewing the relevant literature; and 3) examining the medical records of sponge divers who underwent recompression treatment. These divers used three types of surface-supplied equipment, including hard helmets, Fernez apparatus, and hookahs; the latter were preferred because they allowed divers the greatest freedom of movement while harvesting sponges underwater. These divers used profiles that we now know involved a high risk for DCS and DON. We were able to access the records of 58 divers who had received recompression treatment. All of the cases involved severe DCS and delays from dive to recompression that averaged 72 h. Complete resolution of symptoms occurred in only 11 cases (19%). Thus, we were able to document the several factors that contributed to the risks in this occupational group, including unsafe dive profiles, resistance to seeking treatment, long delays before recompression, and the fact that recompression treatment used air rather than oxygen.

  7. A Review of Energy Storage Technologies

    DEFF Research Database (Denmark)

    Connolly, David

    2010-01-01

    A brief examination into the energy storage techniques currently available for the integration of fluctuating renewable energy was carried out. These included Pumped Hydroelectric Energy Storage (PHES), Underground Pumped Hydroelectric Energy Storage (UPHES), Compressed Air Energy Storage (CAES...... than PHES depending on the availability of suitable sites. FBES could also be utilised in the future for the integration of wind, but it may not have the scale required to exist along with electric vehicles. The remaining technologies will most likely be used for their current applications...

  8. Compressed air leak detection based on time delay estimation using a portable multi-sensor ultrasonic detector

    International Nuclear Information System (INIS)

    Liao, Pingping; Cai, Maolin; Shi, Yan; Fan, Zichuan

    2013-01-01

    The conventional ultrasonic method for compressed air leak detection utilizes a directivity-based ultrasonic leak detector (DULD) to locate the leak. The location accuracy of this method is low due to the limit of the nominal frequency and the size of the ultrasonic sensor. In order to overcome this deficiency, a method based on time delay estimation (TDE) is proposed. The method utilizes three ultrasonic sensors arranged in an equilateral triangle to simultaneously receive the ultrasound generated by the leak. The leak can be located according to time delays between every two sensor signals. The theoretical accuracy of the method is analyzed, and it is found that the location error increases linearly with delay estimation error and the distance from the leak to the sensor plane, and the location error decreases with the distance between sensors. The average square difference function delay estimator with parabolic fitting is used and two practical techniques are devised to remove the anomalous delay estimates. Experimental results indicate that the location accuracy using the TDE-based ultrasonic leak detector is 6.5–8.3 times as high as that using the DULD. By adopting the proposed method, the leak can be located more accurately and easily, and then the detection efficiency is improved. (paper)

  9. Assessment of air quality after the implementation of compressed natural gas (CNG) as fuel in public transport in Delhi, India.

    Science.gov (United States)

    Ravindra, Khaiwal; Wauters, Eric; Tyagi, Sushil K; Mor, Suman; Van Grieken, René

    2006-04-01

    Public transport in Delhi was amended by the Supreme Court of India to use Compressed Natural Gas (CNG) instead of diesel or petrol. After the implementation of CNG since April 2001, Delhi has the highest fraction of CNG-run public vehicles in the world and most of them were introduced within 20 months. In the present study, the concentrations of various criteria air pollutants (SPM, PM(10), CO, SO(2) and NO(x)) and organic pollutants such as benzene, toluene, xylene (BTX) and polycyclic aromatic hydrocarbons (PAHs) were assessed before and after the implementation of CNG. A decreasing trend was found for PAHs, SO(2) and CO concentrations, while the NO(x) level was increased in comparison to those before the implementation of CNG. Further, SPM, PM(10), and BTX concentrations showed no significant change after the implementation of CNG. However, the BTX concentration demonstrated a clear relation with the benzene content of gasoline. In addition to the impact of the introduction of CNG the daily variation in PAHs levels was also studied and the PAHs concentrations were observed to be relatively high between 10 pm to 6 am, which gives a proof of a relation with the limited day entry and movement of heavy vehicles in Delhi.

  10. Inner Ear Barotrauma After Underwater Pool Competency Training Without the Use of Compressed Air Case and Review.

    Science.gov (United States)

    McIntire, Sean; Boujie, Lee

    2016-01-01

    Inner ear barotrauma can occur when the gas-filled chambers of the ear have difficulty equalizing pressure with the outside environment after changes in ambient pressure. This can transpire even with small pressure changes. Hypobaric or hyperbaric environments can place significant stress on the structures of the middle and inner ear. If methods to equalize pressure between the middle ear and other connected gas-filled spaces (i.e., Valsalva maneuver) are unsuccessful, middle ear overpressurization can occur. This force can be transmitted to the fluid-filled inner ear, making it susceptible to injury. Damage specifically to the structures of the vestibulocochlear system can lead to symptoms of vertigo, hearing loss, and tinnitus. This article discusses the case of a 23-year-old male Marine who presented with symptoms of nausea and gait instability after performing underwater pool competency exercises to a maximum depth of 13 feet, without breathing compressed air. Diagnosis and management of inner ear barotrauma are reviewed, as is differentiation from inner ear decompression sickness. 2016.

  11. Compressed air system best practice programmes: What needs to change to secure long-term energy savings for New Zealand?

    International Nuclear Information System (INIS)

    Neale, James R.; Kamp, Peter J.J.

    2009-01-01

    The establishment of a compressed air system (CAS) best practice programme is a key component of one of the initial industrial energy efficiency programmes being driven by New Zealand government ministries and agencies. In a global context this is not a new initiative in that existing programmes have been functioning in Europe and USA, yet in each of these cases the impact ten years-on has been patchy with limited long-term improvements in overall energy efficiency. The New Zealand CAS best practice programme currently under development is sponsored by the Electricity Commission (EC) and the Energy Efficiency Conservation Authority (EECA). It takes a new approach in policy direction, with variations from those used in other international programmes. A significant level of electricity levy money is to be committed to this programme and it is timely to highlight its merits and potential weaknesses, and what is required to generate long-term energy savings beyond the levels achieved by more mature overseas programmes.

  12. Smoothing-based compressed state Kalman filter for joint state-parameter estimation: Applications in reservoir characterization and CO2 storage monitoring

    Science.gov (United States)

    Li, Y. J.; Kokkinaki, Amalia; Darve, Eric F.; Kitanidis, Peter K.

    2017-08-01

    The operation of most engineered hydrogeological systems relies on simulating physical processes using numerical models with uncertain parameters and initial conditions. Predictions by such uncertain models can be greatly improved by Kalman-filter techniques that sequentially assimilate monitoring data. Each assimilation constitutes a nonlinear optimization, which is solved by linearizing an objective function about the model prediction and applying a linear correction to this prediction. However, if model parameters and initial conditions are uncertain, the optimization problem becomes strongly nonlinear and a linear correction may yield unphysical results. In this paper, we investigate the utility of one-step ahead smoothing, a variant of the traditional filtering process, to eliminate nonphysical results and reduce estimation artifacts caused by nonlinearities. We present the smoothing-based compressed state Kalman filter (sCSKF), an algorithm that combines one step ahead smoothing, in which current observations are used to correct the state and parameters one step back in time, with a nonensemble covariance compression scheme, that reduces the computational cost by efficiently exploring the high-dimensional state and parameter space. Numerical experiments show that when model parameters are uncertain and the states exhibit hyperbolic behavior with sharp fronts, as in CO2 storage applications, one-step ahead smoothing reduces overshooting errors and, by design, gives physically consistent state and parameter estimates. We compared sCSKF with commonly used data assimilation methods and showed that for the same computational cost, combining one step ahead smoothing and nonensemble compression is advantageous for real-time characterization and monitoring of large-scale hydrogeological systems with sharp moving fronts.

  13. An efficient HW and SW design of H.264 video compression, storage and playback on FPGA devices for handheld thermal imaging systems

    Science.gov (United States)

    Gunay, Omer; Ozsarac, Ismail; Kamisli, Fatih

    2017-05-01

    Video recording is an essential property of new generation military imaging systems. Playback of the stored video on the same device is also desirable as it provides several operational benefits to end users. Two very important constraints for many military imaging systems, especially for hand-held devices and thermal weapon sights, are power consumption and size. To meet these constraints, it is essential to perform most of the processing applied to the video signal, such as preprocessing, compression, storing, decoding, playback and other system functions on a single programmable chip, such as FPGA, DSP, GPU or ASIC. In this work, H.264/AVC (Advanced Video Coding) compatible video compression, storage, decoding and playback blocks are efficiently designed and implemented on FPGA platforms using FPGA fabric and Altera NIOS II soft processor. Many subblocks that are used in video encoding are also used during video decoding in order to save FPGA resources and power. Computationally complex blocks are designed using FPGA fabric, while blocks such as SD card write/read, H.264 syntax decoding and CAVLC decoding are done using NIOS processor to benefit from software flexibility. In addition, to keep power consumption low, the system was designed to require limited external memory access. The design was tested using 640x480 25 fps thermal camera on CYCLONE V FPGA, which is the ALTERA's lowest power FPGA family, and consumes lower than 40% of CYCLONE V 5CEFA7 FPGA resources on average.

  14. Humidity-dependent compression-induced glass transition of the air-water interfacial Langmuir films of poly(D,L-lactic acid-ran-glycolic acid) (PLGA).

    Science.gov (United States)

    Kim, Hyun Chang; Lee, Hoyoung; Jung, Hyunjung; Choi, Yun Hwa; Meron, Mati; Lin, Binhua; Bang, Joona; Won, You-Yeon

    2015-07-28

    Constant rate compression isotherms of the air-water interfacial Langmuir films of poly(D,L-lactic acid-ran-glycolic acid) (PLGA) show a distinct feature of an exponential increase in surface pressure in the high surface polymer concentration regime. We have previously demonstrated that this abrupt increase in surface pressure is linked to the glass transition of the polymer film, but the detailed mechanism of this process is not fully understood. In order to obtain a molecular-level understanding of this behavior, we performed extensive characterizations of the surface mechanical, structural and rheological properties of Langmuir PLGA films at the air-water interface, using combined experimental techniques including the Langmuir film balance, X-ray reflectivity and double-wall-ring interfacial rheometry methods. We observed that the mechanical and structural responses of the Langmuir PLGA films are significantly dependent on the rate of film compression; the glass transition was induced in the PLGA film only at fast compression rates. Surprisingly, we found that this deformation rate dependence is also dependent on the humidity of the environment. With water acting as a plasticizer for the PLGA material, the diffusion of water molecules through the PLGA film seems to be the key factor in the determination of the glass transformation properties and thus the mechanical response of the PLGA film against lateral compression. Based on our combined results, we hypothesize the following mechanism for the compression-induced glass transformation of the Langmuir PLGA film; (1) initially, a humidified/non-glassy PLGA film is formed in the full surface-coverage region (where the surface pressure shows a plateau) during compression; (2) further compression leads to the collapse of the PLGA chains and the formation of new surfaces on the air side of the film, and this newly formed top layer of the PLGA film is transiently glassy in character because the water evaporation rate

  15. The effect of compositional changes on the structural and hydrogen storage properties of (La–Ce)Ni5 type intermetallics towards compounds suitable for metal hydride hydrogen compression

    International Nuclear Information System (INIS)

    Odysseos, M.; De Rango, P.; Christodoulou, C.N.; Hlil, E.K.; Steriotis, T.; Karagiorgis, G.; Charalambopoulou, G.; Papapanagiotou, T.; Ampoumogli, A.; Psycharis, V.; Koultoukis, E.; Fruchart, D.; Stubos, A.

    2013-01-01

    Graphical abstract: The effect of the partial substitution of La with Ce on the crystal structure and the final hydrogen storage properties of the alloys. Highlights: ► Absorption-based systems exploit the properties of reversible metal hydrides. ► AB5 intermetallics are mostly popular for thermal desorption compressors. ► Investigation of H2 absorption/desorption properties of LaNi5 and its derivatives. ► LaNi5 thermodynamic properties adjustment by partially replacing La with rare earths. -- Abstract: The present work has been aiming at the synthesis and study of a series of La 1−x Ce x Ni 5 (x = 0, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8) alloys in an attempt to investigate possible alterations of the hydrogen absorption/desorption properties The alloys were prepared by induction melting of the constituent elements. The systematic characterization of all new compounds by means of XRD and hydrogen sorption measurements revealed the effect of the partial substitution of La with Ce on the crystal structure and the final hydrogen storage properties of the alloys. Extensive absorption/desorption experiments (Van’t Hoff diagrams) have shown that such alloys can be used to build a metal hydride compressor (MHC), compressing H 2 gas from 0.2 MPa to 4.2 MPa using cold (20 °C) and hot (80 °C) water

  16. Predictive evaluation of pharmaceutical properties of direct compression tablets containing theophylline anhydrate during storage at high humidity by near-infrared spectroscopy.

    Science.gov (United States)

    Otsuka, Yuta; Yamamoto, Masahiro; Tanaka, Hideji; Otsuka, Makoto

    2015-01-01

    Theophylline anhydrate (TA) in tablet formulation is transformed into monohydrate (TH) at high humidity and the phase transformation affected dissolution behavior. Near-infrared spectroscopic (NIR) method is applied to predict the change of pharmaceutical properties of TA tablets during storage at high humidity. The tablet formulation containing TA, lactose, crystalline cellulose and magnesium stearate was compressed at 4.8 kN. Pharmaceutical properties of TA tables were measured by NIR, X-ray diffraction analysis, dissolution test and tablet hardness. TA tablet was almost 100% transformed into TH after 24 hours at RH 96%. The pharmaceutical properties of TA tablets, such as tablet hardness, 20 min dissolution amount (D20) and increase of tablet weight (TW), changed with the degree of hydration. Calibration models for TW, tablet hardness and D20 to predict the pharmaceutical properties at high-humidity conditions were developed on the basis of the NIR spectra by partial least squares regression analysis. The relationships between predicted and actual measured values for TW, tablet hardness and D20 had straight lines, respectively. From the results of NIR-chemometrics, it was confirmed that these predicted models had high accuracy to monitor the tablet properties during storage at high humidity.

  17. Design for limit stresses of orange fruits (Citrus sinensis under axial and radial compression as related to transportation and storage design

    Directory of Open Access Journals (Sweden)

    Christopher Chukwutoo Ihueze

    2017-01-01

    Full Text Available This article employed the Hertz contact stress theory and the finite element method to evaluate the maximum contact pressure and the limit stresses of orange fruit under transportation and storage. The elastic properties of orange fruits subjected to axial and axial contact were measured such that elastic limit force, elastic modulus, Poisson’s ratio and bioyield stress were obtained as 18 N, 0.691 MPa, 0.367, 0.009 MPa for axial compression and for radial loading were 15.69 N, 0.645 MPa, 0.123, 0.010 MPa. The Hertz maximum contact pressure was estimated for axial and radial contacts as 0.036 MPa. The estimated limiting yield stress estimated as von Mises stresses for the induced surface stresses of the orange topologies varied from 0.005 MPa–0.03 MPa. Based on the distortion energy theory (DET the yield strength of orange fruit is recommended as 0.03 MPa while based on the maximum shear stress theory (MSST is 0.01 MPa for the design of orange transportation and storage system.

  18. Numerical analysis for two-dimensional compressible and two-phase flow fields of air-water in Eulerian grid framework

    International Nuclear Information System (INIS)

    Park, Chan Wook; Lee, Sung Su

    2008-01-01

    Two-phase compressible flow fields of air-water are investigated numerically in the fixed Eulerian grid framework. The phase interface is captured via volume fractions of ech phase. A way to model two phase compressible flows as a single phase one is found based on an equivalent equation of states of Tait's type for a multiphase cell. The equivalent single phase field is discretized using the Roe's approximate Riemann solver. Two approaches are tried to suppress the pressure oscillation phenomena at the phase interface, a passive advection of volume fraction and a direct pressure relaxation with the compressible form of volume fraction equation. The direct pressure equalizing method suppresses pressure oscillation successfully and generates sharp discontinuities, transmitting and reflecting acoustic waves naturally at the phase interface. In discretizing the compressible form of volume fraction equation, phase interfaces are geometrically reconstructed to minimize the numerical diffusion of volume fraction and relevant variables. The motion of a projectile in a water-filled tube which is fired by the release of highly pressurized air is simulated presuming the flow field as a two dimensional one, and several design factors affecting the projectile movement are investigated

  19. Implementation of a multi-lingual, Internet-supported benchmarking system for compressed-air installations; Umsetzung eines mehrsprachigen internetgestuetzten Benchmarking von Druckluftanlagen

    Energy Technology Data Exchange (ETDEWEB)

    Radgen, P.

    2005-07-01

    This final report for the Swiss Federal Office of Energy (SFOE) discusses how know-how can be improved and how optimisation activities can be stimulated in the area of compressed-air generation. The authors estimate that potential energy-savings of 20 to 40% are possible. The aim of the project - to introduce a benchmarking system already in use in Germany to the Swiss market - is discussed. This benchmarking is to help companies identify weak points in their compressed-air systems. An Internet-based information platform is introduced which was realised in 2004 and is being continually extended. The use of the benchmarking process is illustrated with a comprehensive flow-diagram and 'screen-shots' of the relevant Internet pages.

  20. Development of a Next-Generation Membrane-Integrated Adsorption Processor for CO2 Removal and Compression for Closed-Loop Air Revitalization Systems

    Science.gov (United States)

    Mulloth, Lila; LeVan, Douglas

    2002-01-01

    The current CO2 removal technology of NASA is very energy intensive and contains many non-optimized subsystems. This paper discusses the concept of a next-generation, membrane integrated, adsorption processor for CO2 removal nd compression in closed-loop air revitalization systems. This processor will use many times less power than NASA's current CO2 removal technology and will be capable of maintaining a lower CO2 concentration in the cabin than that can be achieved by the existing CO2 removal systems. The compact, consolidated, configuration of gas dryer, CO2 separator, and CO2 compressor will allow continuous recycling of humid air in the cabin and supply of compressed CO2 to the reduction unit for oxygen recovery. The device has potential application to the International Space Station and future, long duration, transit, and planetary missions.

  1. Survey and assessment of radioactive waste management facilities in the United States. Section 2.5. Air-cooled vault storage facilities

    International Nuclear Information System (INIS)

    1986-01-01

    There are two basic types of air-cooled vaults for the storage of spent nuclear fuel or vitrified HLRW. The two types, differentiated by the method of air cooling used, are the open-vault concept and the closed-vault concept. The following aspects of these air-cooled vault storage facility concepts are discussed: description and operation of facilities; strucutral design considerations and analysis; nuclear design considerations and analyses; vault environmental design considerations; unique design features; and accident analysis

  2. Energy Storage Systems

    Science.gov (United States)

    Elliott, David

    2017-07-01

    As renewable energy use expands there will be a need to develop ways to balance its variability. Storage is one of the options. Presently the main emphasis is for systems storing electrical power in advanced batteries (many of them derivatives of parallel developments in the electric vehicle field), as well as via liquid air storage, compressed air storage, super-capacitors and flywheels, and, the leader so far, pumped hydro reservoirs. In addition, new systems are emerging for hydrogen generation and storage, feeding fuel cell power production. Heat (and cold) is also a storage medium and some systems exploit thermal effects as part of wider energy management activity. Some of the more exotic ones even try to use gravity on a large scale. This short book looks at all the options, their potentials and their limits. There are no clear winners, with some being suited to short-term balancing and others to longer-term storage. The eventual mix adopted will be shaped by the pattern of development of other balancing measures, including smart-grid demand management and super-grid imports and exports.

  3. The start-up of a gas turbine engine using compressed air tangentially fed onto the blades of the basic turbine

    Science.gov (United States)

    Slobodyanyuk, L. K.; Dayneko, V. I.

    1983-01-01

    The use of compressed air was suggested to increase the reliability and motor lifetime of a gas turbine engine. Experiments were carried out and the results are shown in the form of the variation in circumferential force as a function of the entry angle of the working jet onto the turbine blade. The described start-up method is recommended for use with massive rotors.

  4. N-decane-air end-gas auto-ignition induced by flame propagation in a constant volume chamber: Influence of compression history

    OpenAIRE

    Quintens , Hugo; Strozzi , Camille; Zitoun , Ratiba; Bellenoue , Marc

    2017-01-01

    International audience; The present study aims at characterizing the end-gas auto-ignition of n-decane – air mixtures induced by a flame propagation in a constant volume chamber. A numerical tool is developed, and the study is first focused on academic compressions, e.g. at constant rate of pressure rise. Thermodynamic conditions of transition from deflagration to auto-ignition are first determined, and the involved physical processes are highlighted. A square section combustion chamber is th...

  5. Development of salt hydrate eutectics as latent heat storage for air conditioning and cooling

    Energy Technology Data Exchange (ETDEWEB)

    Efimova, Anastasia [Brandenburgische Technische Universität (BTU) Cottbus – Senftenberg, Chair of Inorganic Chemistry, Großenhainer Str. 57, 01968 Senftenberg (Germany); Pinnau, Sebastian; Mischke, Matthias; Breitkopf, Cornelia [Technische Universität Dresden, Chair of Technical Thermodynamics, Helmholtzstr. 14, 01069 Dresden (Germany); Ruck, Michael [Technische Universität Dresden, Chair of Inorganic Chemistry, Bergstr. 66, 01062 Dresden (Germany); Schmidt, Peer, E-mail: peer.schmidt@hs-lausitz.de [Brandenburgische Technische Universität (BTU) Cottbus – Senftenberg, Chair of Inorganic Chemistry, Großenhainer Str. 57, 01968 Senftenberg (Germany)

    2014-01-10

    Graphical abstract: - Highlights: • Inorganic salt hydrates. • Latent heat thermal energy storage. • Thermal behavior of melting and crystallization. • Cycling stability. • Nucleation. - Abstract: Sustainable air conditioning systems require heat reservoirs that operate between 4 and 20 °C. A systematic search for binary and ternary eutectics of inorganic salts and salt hydrates with melting temperatures in this temperature regime and with high enthalpies of fusion has been performed by means of differential scanning calorimetry (DSC). Promising results were obtained for the pseudo-ternary system Zn(NO{sub 3}){sub 2}·6H{sub 2}O, Mn(NO{sub 3}){sub 2}·4H{sub 2}O, and KNO{sub 3} with the melting temperature range 18–21 °C and the enthalpy of fusion of about 110 kJ kg{sup −1}. Suitable nucleating and thickening agents have been found and tested to prevent the mixture from supercooling and phase separation.

  6. Transmissivity and storage coefficient estimates from slug tests, Naval Air Warfare Center, West Trenton, New Jersey

    Science.gov (United States)

    Fiore, Alex R.

    2014-01-01

    Slug tests were conducted on 56 observation wells open to bedrock at the former Naval Air Warfare Center (NAWC) in West Trenton, New Jersey. Aquifer transmissivity (T) and storage coefficient (S) values for most wells were estimated from slug-test data using the Cooper-Bredehoeft-Papadopulos method. Test data from three wells exhibited fast, underdamped water-level responses and were analyzed with the Butler high-K method. The range of T at NAWC was approximately 0.07 to 10,000 square feet per day. At 11 wells, water levels did not change measurably after 20 minutes following slug insertion; transmissivity at these 11 wells was estimated to be less than 0.07 square feet per day. The range of S was approximately 10-10 to 0.01, the mode being 10-10. Water-level responses for tests at three wells fit poorly to the type curves of both methods, indicating that these methods were not appropriate for adequately estimating T and S from those data.

  7. Operational procedure for computer program for design point characteristics of a compressed-air generator with through-flow combustor for V/STOL applications

    Science.gov (United States)

    Krebs, R. P.

    1971-01-01

    The computer program described in this report calculates the design-point characteristics of a compressed-air generator for use in V/STOL applications such as systems with a tip-turbine-driven lift fan. The program computes the dimensions and mass, as well as the thermodynamic performance of a model air generator configuration which involves a straight through-flow combustor. Physical and thermodynamic characteristics of the air generator components are also given. The program was written in FORTRAN IV language. Provision has been made so that the program will accept input values in either SI units or U.S. customary units. Each air generator design-point calculation requires about 1.5 seconds of 7094 computer time for execution.

  8. Nonradioactive Air Emissions Notice of Construction (NOC) Application for the Central Waste Complex (CSC) for Storage of Vented Waste Containers

    International Nuclear Information System (INIS)

    KAMBERG, L.D.

    2000-01-01

    This Notice of Construction (NOC) application is submitted for the storage and management of waste containers at the Central Waste Complex (CWC) stationary source. The CWC stationary source consists of multiple sources of diffuse and fugitive emissions, as described herein. This NOC is submitted in accordance with the requirements of Washington Administrative Code (WAC) 173-400-110 (criteria pollutants) and 173-460-040 (toxic air pollutants), and pursuant to guidance provided by the Washington State Department of Ecology (Ecology). Transuranic (TRU) mixed waste containers at CWC are vented to preclude the build up of hydrogen produced as a result of radionuclide decay, not as safety pressure releases. The following activities are conducted within the CWC stationary source: Storage and inspection; Transfer and staging; Packaging; Treatment; and Sampling. This NOC application is intended to cover all existing storage structures within the current CWC treatment, storage, and/or disposal (TSD) boundary, as well as any storage structures, including waste storage pads and staging areas, that might be constructed in the future within the existing CWC boundary

  9. Radon in air concentrations arising from storage of articles containing radium or thorium

    International Nuclear Information System (INIS)

    Slater, M.; Gooding, M.

    2006-01-01

    A major component of public and occupational radiation exposure worldwide arises from the inhalation of radon and thoron gases, produced during the decay of naturally occurring uranium and thorium respectively. Whilst radon and thoron exposures are normally associated with the natural environment, there may also be a risk associated with sources, manufactured articles and waste produced through refining and concentration of naturally occurring radioactive material. Sources and articles manufactured from refined uranium do not normally give rise to the release of radon as the uranium progeny are largely removed during production and, if removed, will take thousands of years to reach full equilibrium with the uranium parent isotopes. Exposure to radon -222 ( 222 Rn) may, however, arise in areas where the uranium-238 ( 238 U) daughter radium-226 ( 226 Ra) is concentrated, for example in the form of sources, luminous articles or low-specific activity (LSA) scale. Exposure to radon- 220 ( 220 Rn), otherwise known as thoron, may occur in areas where thorium isotopes are concentrated, for example as manufactured laboratory thorium compounds. This paper explores the issues affecting radon and thoron release from manufactured articles containing uranium and thorium and their progeny. A methodology is provided for the calculation of 222 Rn and 220 Rn in air concentrations likely to arise as a result of the storage and use of articles containing radium-226 ( 226 Ra) or thorium-232 ( 232 Th). The methodology provided in the document allows derivation of the equilibrium equivalent radon concentration and the radon exposure rate in circumstances where the ventilation rate and volume of the facility can be reliably estimated and the quantities of 226 Ra or 232 Th held are known. A critical variable in the calculation is the release fraction (i.e. the proportion of radon generated that is release to atmosphere), and this paper considers methods for estimating this parameter

  10. Clean air program : design guidelines for bus transit systems using compressed natural gas as an alternative fuel

    Science.gov (United States)

    1996-06-01

    This report documents design guidelines for the safe use of Compressed Natural Gas (CNG). The report is designed to provide guidance, information on safe industry practices, applicable national codes and standards, and reference data that transit age...

  11. Self-assembled air-stable magnesium hydride embedded in 3-D activated carbon for reversible hydrogen storage.

    Science.gov (United States)

    Shinde, S S; Kim, Dong-Hyung; Yu, Jin-Young; Lee, Jung-Ho

    2017-06-01

    The rational design of stable, inexpensive catalysts with excellent hydrogen dynamics and sorption characteristics under realistic environments for reversible hydrogen storage remains a great challenge. Here, we present a simple and scalable strategy to fabricate a monodispersed, air-stable, magnesium hydride embedded in three-dimensional activated carbon with periodic synchronization of transition metals (MHCH). The high surface area, homogeneous distribution of MgH 2 nanoparticles, excellent thermal stability, high energy density, steric confinement by carbon, and robust architecture of the catalyst resulted in a noticeable enhancement of the hydrogen storage performance. The resulting MHCH-5 exhibited outstanding hydrogen storage performance, better than that of most reported Mg-based hydrides, with a high storage density of 6.63 wt% H 2 , a rapid kinetics loading in hydrogenation compared to that of commercial MgH 2 . The origin of the intrinsic hydrogen thermodynamics was elucidated via solid state 1 H NMR. This work presents a readily scaled-up strategy towards the design of realistic catalysts with superior functionality and stability for applications in reversible hydrogen storage, lithium ion batteries, and fuel cells.

  12. Thermo-Hydraulic Analysis of Heat Storage Filled with the Ceramic Bricks Dedicated to the Solar Air Heating System.

    Science.gov (United States)

    Nemś, Magdalena; Nemś, Artur; Kasperski, Jacek; Pomorski, Michał

    2017-08-12

    This article presents the results of a study into a packed bed filled with ceramic bricks. The designed storage installation is supposed to become part of a heating system installed in a single-family house and eventually to be integrated with a concentrated solar collector adapted to climate conditions in Poland. The system's working medium is air. The investigated temperature ranges and air volume flow rates in the ceramic bed were dictated by the planned integration with a solar air heater. Designing a packed bed of sufficient parameters first required a mathematical model to be constructed and heat exchange to be analyzed, since heat accumulation is a complex process influenced by a number of material properties. The cases discussed in the literature are based on differing assumptions and different formulas are used in calculations. This article offers a comparison of various mathematical models and of system operating parameters obtained from these models. The primary focus is on the Nusselt number. Furthermore, in the article, the thermo-hydraulic efficiency of the investigated packed bed is presented. This part is based on a relationship used in solar air collectors with internal storage.

  13. Thermo-Hydraulic Analysis of Heat Storage Filled with the Ceramic Bricks Dedicated to the Solar Air Heating System

    Science.gov (United States)

    Nemś, Magdalena; Nemś, Artur; Kasperski, Jacek; Pomorski, Michał

    2017-01-01

    This article presents the results of a study into a packed bed filled with ceramic bricks. The designed storage installation is supposed to become part of a heating system installed in a single-family house and eventually to be integrated with a concentrated solar collector adapted to climate conditions in Poland. The system’s working medium is air. The investigated temperature ranges and air volume flow rates in the ceramic bed were dictated by the planned integration with a solar air heater. Designing a packed bed of sufficient parameters first required a mathematical model to be constructed and heat exchange to be analyzed, since heat accumulation is a complex process influenced by a number of material properties. The cases discussed in the literature are based on differing assumptions and different formulas are used in calculations. This article offers a comparison of various mathematical models and of system operating parameters obtained from these models. The primary focus is on the Nusselt number. Furthermore, in the article, the thermo-hydraulic efficiency of the investigated packed bed is presented. This part is based on a relationship used in solar air collectors with internal storage. PMID:28805703

  14. Air-guided photonic-crystal-fiber pulse-compression delivery of multimegawatt femtosecond laser output for nonlinear-optical imaging and neurosurgery

    Science.gov (United States)

    Lanin, Aleksandr A.; Fedotov, Il'ya V.; Sidorov-Biryukov, Dmitrii A.; Doronina-Amitonova, Lyubov V.; Ivashkina, Olga I.; Zots, Marina A.; Sun, Chi-Kuang; Ömer Ilday, F.; Fedotov, Andrei B.; Anokhin, Konstantin V.; Zheltikov, Aleksei M.

    2012-03-01

    Large-core hollow photonic-crystal fibers (PCFs) are shown to enable a fiber-format air-guided delivery of ultrashort infrared laser pulses for neurosurgery and nonlinear-optical imaging. With an appropriate dispersion precompensation, an anomalously dispersive 15-μm-core hollow PCF compresses 510-fs, 1070-nm light pulses to a pulse width of about 110 fs, providing a peak power in excess of 5 MW. The compressed PCF output is employed to induce a local photodisruption of corpus callosum tissues in mouse brain and is used to generate the third harmonic in brain tissues, which is captured by the PCF and delivered to a detector through the PCF cladding.

  15. Energy storage. A challenge for energy transition

    International Nuclear Information System (INIS)

    Bart, Jean-Baptiste; Nekrasov, Andre; Pastor, Emmanuel; Benefice, Emmanuel; Brincourt, Thierry; Brisse, Annabelle; Cagnac, Albannie; Delille, Gauthier; Hinchliffe, Timothee; Lancel, Gilles; Jeandel, Elodie; Lefebvre, Thierry; Loevenbruck, Philippe; Penneau, Jean-Francois; Soler, Robert; Stevens, Philippe; Radvanyi, Etienne; Torcheux, Laurent

    2017-06-01

    Written by several EDF R and D engineers, this book aims at presenting an overview of knowledge and know-how of EDF R and D in the field of energy storage, and at presenting the different technologies and their application to electric power systems. After a description of the context related to a necessary energy transition, the authors present the numerous storage technologies. They distinguish direct storage of power (pumped storage water stations, compressed air energy storage, flywheels, the various electrochemical batteries, metal-air batteries, redox flow batteries, superconductors), thermal storage (power to heat, heat to power) and hydrogen storage (storage under different forms), and propose an overview of the situation of standardisation of storage technologies. In the next part, they give an overview of the main services provided by storage to the electric power system: production optimisation, frequency adjustment, grid constraint resolution, local smoothing of PV and wind production, supply continuity. The last part discusses perspectives regarding the role of tomorrow's storage in the field of electrical mobility, for emerging markets, and with respect to different scenarios

  16. Heat recovery from the compressed air of activation tanks at Herdorf sewage plant. Final report; Waermerueckgewinnung aus der Druckluft von Belebungsanlagen am Beispiel der Verbandsklaeranlage Herdorf. Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Witte, H.; Strunkheide, J.; Eckhardt, R.

    2001-01-01

    Heat is removed from the compressed air of the activation tanks via a separate air cooler installed in the compressed-air line leading to the activation tank. The heat recovered will heat up the sludge in the digestion tank or will be fed into the heating system of the plant. The following goals are defined: Savings of heating oil; Saving of digestion gas as completely as possible; Power generation from the saved gas in a cogeneration unit; Power supply to the public grid. [German] Zielsetzung des Pilotprojektes ist die Nutzung der Druckluftwaerme von Belebungsanlagen als eine Moeglichkeit der Energieeinsparung auf Klaeranlagen. Die Nutzung der Verlustwaerme soll durch Abgriff der Waerme ueber einen separaten Luftkuehler erfolgen, der direkt in der Druckluftleitung zum Belebungsbecken installiert ist. Die auf diese Weise zurueckgewonnene Waerme soll zur Rohschlammaufheizung im Faulungsprozess dienen bzw. in das Betriebsheizungssystem eingespeist werden. Somit koennen folgende Ziele der Waermerueckgewinnungsanlage ins Auge gefasst werden: - Einsparung von Heizoel zu Heizzwecken in den Betriebsanlagen der Klaeranlage - Moeglichst komplette Einsparung von Faulgas im Heizkessel daraus folgend: - Mehrverstromung der im Heizkessel weniger verbrauchten Gasmengen im Blockheizkraftwerk (BHKW) mit dem Ergebnis: - Wirtschaftlicher Ertrag durch Einspeisung dieser Mehrmengen an Strom in das oeffentliche Versorgungsnetz. (orig.)

  17. Compressed air blast injury with palpebral, orbital, facial, cervical, and mediastinal emphysema through an eyelid laceration: a case report and review of literature.

    Science.gov (United States)

    Hiraoka, Takahiro; Ogami, Tomohiro; Okamoto, Fumiki; Oshika, Tetsuro

    2013-11-07

    To the best of our knowledge, only 14 cases of orbital or periorbital compressed air injuries from air guns or hoses have been reported in the literature. A 30-year-old man was accidentally injured when a compressed air hose nozzle hit his right eye. The right half of his face was markedly swollen and a skin laceration near the right medial canthus was identified. A computed tomography scan showed subcutaneous and intraorbital emphysema around the right eye as well as cervical and mediastinal emphysema. He was prophylactically treated with systemic and topical antibiotics to prevent infection. All emphysemas had completely resolved 2 weeks after the injury. A review of all 15 cases (including ours) showed that all patients were male and that 6 of the 15 (40.0%) cases were related to industrial accidents. Although emphysema was restricted to the subconjunctival space in 2 (13.3%) cases, it spread to the orbit in the remaining 13 (86.7%) cases. Cervical and mediastinal emphysemas were found in 3 (20.0%) cases, and intracranial emphysema was confirmed in 6 (40.0%) cases. Prophylactic antibiotics were used in most cases and the prognosis was generally good in all but one patient, who developed optic atrophy and blindness.

  18. Energy storage: a review of recent literature

    International Nuclear Information System (INIS)

    Tatone, O.S.

    1981-12-01

    Recent literature on the technological and economic status of reversible energy storage has been reviewed. A broad range of research and development activities have been pursued between 1975 and the present. Most of this work has concentrated on improving technical and economic performance of previously known storage technologies. Hydraulic pumped storage with both reservoirs above ground and compressed air storage (1 plant) are the only methods that have been adopted by electric utilities. The need for electrical energy storage in Canada has not been acute because of the large proportion of hydraulic generation which incorporates some storge and, in most cases, can readily be used for load-following. Residential heat storage in ceramic room heaters has been used in Europe for several years. For Canadian climatic and market conditions larger, central heating units would be required. Residential heat storage depends upon utilities offering time-of-use rates and none in Canada do so at present. Most seasonal storage concepts depend upon storage of low-grade heat for district heating. The cost of energy storage is highly dependent upon annual energy throughput and hence favours smaller capacity systems operating on frequent charge/discharge cycles over long-term storage. Capital costs of energy storage methods from the literature, expressed in constant dollars, are compared graphically and tentative investment costs are presented for several storage methods

  19. Storage the electric power: yes, it is indispensable and it is possible. Why, where, how

    International Nuclear Information System (INIS)

    2003-01-01

    This document describes the main characteristics of various electric power storage methods and their application domains. The large-scale storages include the hydraulic systems, those using compressed air, the batteries or those implementing a thermal way. The small-scale storages are electrochemical as the accumulators, the super-capacitors, mechanical as the flywheel, magnetic or also by the hydrogen use. The first part presents the necessity of the electric power storage, the second part the places of these storage. The third part details the forms of storage. (A.L.B.)

  20. Energy Conversion and Transmission Characteristics Analysis of Ice Storage Air Conditioning System Driven by Distributed Photovoltaic Energy System

    Directory of Open Access Journals (Sweden)

    Yongfeng Xu

    2016-01-01

    Full Text Available In order to reduce the investment and operation cost of distributed PV energy system, ice storage technology was introduced to substitute batteries for solar energy storage. Firstly, the ice storage air conditioning system (ISACS driven by distributed photovoltaic energy system (DPES was proposed and the feasibility studies have been investigated in this paper. And then, the theoretical model has been established and experimental work has been done to analyze the energy coupling and transferring characteristics in light-electricity-cold conversion process. In addition, the structure optimization analysis was investigated. Results revealed that energy losses were high in ice making process of ice slide maker with only 17.38% energy utilization efficiency and the energy efficiency and exergy efficiency of ISACS driven by DPES were 5.44% and 67.30%, respectively. So the immersed evaporator and cointegrated exchanger were adopted for higher energy utilization efficiency and better financial rewards in structure optimization. The COP and exergy efficiency of ice maker can be increased to 1.48 and 81.24%, respectively, after optimization and the energy utilization efficiency of ISACS driven by DPES could be improved 2.88 times. Moreover, ISACS has the out-of-the-box function of ordinary air conditioning system. In conclusion, ISACS driven by DPES will have good application prospects in tropical regions without power grid.

  1. Photovoltaic power systems energy storage

    International Nuclear Information System (INIS)

    Buldini, P.L.

    1991-01-01

    Basically, the solar photovoltaic power system consists of: Array of solar panels; Charge/voltage stabilizer; Blocking diode and Storage device. The storage device is a very important part of the system due to the necessity to harmonize the inevitable time shift between energy supply and demand. As energy storage, different devices can be utilized, such as hydropumping, air or other gas compression, flywheel, superconducting magnet, hydrogen generation and so on, but actually secondary (rechargeable) electrochemical cells appear to be the best storage device, due to the direct use for recharge of the d.c. current provided by the solar panels, without any intermediate step of energy transformation and its consequent loss of efficiency

  2. SeqCompress: an algorithm for biological sequence compression.

    Science.gov (United States)

    Sardaraz, Muhammad; Tahir, Muhammad; Ikram, Ataul Aziz; Bajwa, Hassan

    2014-10-01

    The growth of Next Generation Sequencing technologies presents significant research challenges, specifically to design bioinformatics tools that handle massive amount of data efficiently. Biological sequence data storage cost has become a noticeable proportion of total cost in the generation and analysis. Particularly increase in DNA sequencing rate is significantly outstripping the rate of increase in disk storage capacity, which may go beyond the limit of storage capacity. It is essential to develop algorithms that handle large data sets via better memory management. This article presents a DNA sequence compression algorithm SeqCompress that copes with the space complexity of biological sequences. The algorithm is based on lossless data compression and uses statistical model as well as arithmetic coding to compress DNA sequences. The proposed algorithm is compared with recent specialized compression tools for biological sequences. Experimental results show that proposed algorithm has better compression gain as compared to other existing algorithms. Copyright © 2014 Elsevier Inc. All rights reserved.

  3. Electricity storage by gas pumping. An introduction to thermodynamic storage processes

    International Nuclear Information System (INIS)

    Ruer, Jacques

    2013-01-01

    To date, Pumped Hydro Storage (PHS) is practically the only technology used to store large quantities of electricity. There are however other ways to achieve the same goal. There are not yet well known, because the interest for large scale storage is quite new A complete family of storage technologies can be defined as 'Thermodynamic Storage Systems'. Their only common factor is that a gas is pumped and expanded in the process. If the gas is air taken from the atmosphere and discharged to it, the system is said 'an open system'. This is already developed in the form of Compressed Air Energy Storage (CAES). Different embodiments are possible, following the way the heat gene - rated during the compression stage is conserved. The compressed air is generally stored in underground caverns created in deep salt formations. 2 installations are presently operating and many projects are envisaged. if the gas circulates in closed loop within the plant, the system is said 'a closed system' In this case, the energy is stored as heat and/or cold at different temperature levels. A great variety of technologies can be imagined and are under development, using different gases (e.g. argon, CO 2 ) and different temperature ranges. PHS and CAES require specific sites for water reservoirs or underground caverns. The dosed systems can be installed basically anywhere. (author)

  4. Ten questions to Jean Dhers on the storage of electric energy

    International Nuclear Information System (INIS)

    2006-01-01

    The authors proposes a comprehensive set of technical and economical data and information on electricity storage: the reasons to store energy (autonomous, stationary and network applications), the different types and advantages of energy storages with reversible power, the means to massively store electricity to exploit in on the network (description, uses and comparison of pumping energy transfer station, energy storage under the form of compressed air), the inertial storage (storage of kinetic energy accumulated in a flywheel, and its applications), the importance of storage with electrochemical batteries (reversible storage, evolution of batteries in ground transports, main economic sectors for batteries), fuel cells, the role of energy storage by power capacitors, the perspectives of super capacitors in a near future (comparison of their performance with those of batteries, possible applications), the use of electromagnetic storage of electricity (description, advantages, drawbacks and applications of superconducting magnet energy storage or SMES), and how the research on electric power storage is organised

  5. Preparatory work for the start of the Swiss Compressed-Air Efficiency campaign and accompanying work on the setting-up of a compressed air competence centre; Vorarbeiten zum Start der Kampagne Druckluft effizient Schweiz und begleitende Arbeiten zum Aufbau eines Druckluftkompetenzzentrums

    Energy Technology Data Exchange (ETDEWEB)

    Radgen, P. [Fraunhofer-Institut fuer Systemtechnik und Innovationsforschung (ISI), Karlsruhe (Germany); Stadelmann, B. [Hochschule fuer Technik und Architektur (HTA) Luzern, Horw (Switzerland)

    2004-07-01

    This final report for the Swiss Federal Office of Energy (SFOE) takes a look at how a campaign on compressed-air efficiency was prepared. Three work packages are described: The drawing-up of an implementation plan which defined the measures to be implemented by the campaign, incorporation of all relevant players in the preparation and acquisition of companies for the active realisation and co-financing of the activities, and a pilot project to optimise the compressed air supply in a chemical company. The institutions involved are introduced and the definition of the concept to be implemented is discussed. Measurement campaigns, benchmarking and publications to be made are discussed. The implementation of a pilot project at a chemicals company in Switzerland is described.

  6. High Density Hydrogen Storage in Metal Hydride Composites with Air Cooling

    OpenAIRE

    Dieterich, Mila; Bürger, Inga; Linder, Marc

    2015-01-01

    INTRODUCTION In order to combine fluctuating renewable energy sources with the actual demand of electrical energy, storages are essential. The surplus energy can be stored as hydrogen to be used either for mobile use, chemical synthesis or reconversion when needed. One possibility to store the hydrogen gas at high volumetric densities, moderate temperatures and low pressures is based on a chemical reaction with metal hydrides. Such storages must be able to absorb and desorb the hydrogen qu...

  7. Multiple Electron Charge Transfer Chemistries for Electrochemical Energy Storage Systems: The Metal Boride and Metal Air Battery

    Science.gov (United States)

    Stuart, Jessica F.

    The primary focus of this work has been to develop high-energy capacity batteries capable of undergoing multiple electron charge transfer redox reactions to address the growing demand for improved electrical energy storage systems that can be applied to a range of applications. As the levels of carbon dioxide (CO2) increase in the Earth's atmosphere, the effects on climate change become increasingly apparent. According to the Energy Information Administration (EIA), the U.S. electric power sector is responsible for the release of 2,039 million metric tons of CO2 annually, equating to 39% of total U.S. energy-related CO2 emissions. Both nationally and abroad, there are numerous issues associated with the generation and use of electricity aside from the overwhelming dependence on fossil fuels and the subsequent carbon emissions, including reliability of the grid and the utilization of renewable energies. Renewable energy makes up a relatively small portion of total energy contributions worldwide, accounting for only 13% of the 3,955 billion kilowatt-hours of electricity produced each year, as reported by the EIA. As the demand to reduce our dependence on fossils fuels and transition to renewable energy sources increases, cost effective large-scale electrical energy storage must be established for renewable energy to become a sustainable option for the future. A high capacity energy storage system capable of leveling the intermittent nature of energy sources such as solar, wind, and water into the electric grid and provide electricity at times of high demand will facilitate this transition. In 2008, the Licht Group presented the highest volumetric energy capacity battery, the vanadium diboride (VB2) air battery, exceedingly proficient in transferring eleven electrons per molecule. This body of work focuses on new developments to this early battery such as fundamentally understanding the net discharge mechanism of the system, evaluation of the properties and

  8. Thermal performance of solar air collection-storage system with phase change material based on flat micro-heat pipe arrays

    International Nuclear Information System (INIS)

    Wang, Teng-yue; Diao, Yan-hua; Zhu, Ting-ting; Zhao, Yao-hua; Liu, Jing; Wei, Xiang-qian

    2017-01-01

    Highlights: • A new type of solar air collection-storage thermal system with PCM is proposed. • Flat micro-heat pipe array is used as the core heat transfer element. • Air volume flow rate influence charging and discharging time obviously. • Air-side thermal resistance dominates during charging and discharging. - Abstract: In this study, a new type of solar air collection-storage thermal system (ACSTS) with phase change material (PCM) is designed using flat micro-heat pipe arrays (FMHPA) as the heat transfer core element. The solar air collector comprises FMHPA and vacuum tubes. The latent thermal storage device (LTSD) utilizes lauric acid, which is a type of fatty acid, as PCM. The experiments test the performance of collector efficiency and charging and discharging time of thermal storage device through different air volume flow rates. After a range of tests, high air volume flow rate is concluded to contribute to high collector efficiency and short charging and discharging time and enhance instantaneous heat transfer, whereas an air volume flow rate of 60 m"3/h during discharging provides a steady outlet temperature. The cumulative heat transfer during discharging is between 4210 and 4300 kJ.

  9. A Study of Demand Response Effect of Thermal Storage Air-Conditioning Systems in Consideration of Electricity Market Prices

    Science.gov (United States)

    Omagari, Yuko; Sugihara, Hideharu; Tsuji, Kiichiro

    This paper evaluates the economic impact of the introduction of customer-owned Thermal Storage Air-conditioning (TSA) systems, in an electricity market, from the viewpoint of the load service entity. We perform simulations on the condition that several thousand customers install TSA systems and shift peak demand in an electricity market by one percent. Our numerical results indicate that the purchase cost of the LSE was reduced through load management of customers with TSA systems. The introduction of TSA systems also reduced the volatility of market clearing price and reduced the whole-trade cost in an electricity market.

  10. Time-resolved imaging of a compressible air disc under a drop impacting on a solid surface

    KAUST Repository

    Li, Erqiang; Thoroddsen, Sigurdur T

    2015-01-01

    When a drop impacts on a solid surface, its rapid deceleration is cushioned by a thin layer of air, which leads to the entrapment of a bubble under its centre. For large impact velocities the lubrication pressure in this air layer becomes large

  11. Study of an electrical heating system with ductless air supply and shape-stabilized PCM for thermal storage

    International Nuclear Information System (INIS)

    Lin, Kunping; Zhang, Yinping; Di, Hongfa; Yang, Rui

    2007-01-01

    A kind of electrical floor heating system with a shape-stabilized phase change material (PCM) which has been studied at Tsinghua University in our previous studies, can provide space heating during the whole day and can be controlled conventionally. However, this is not suitable for office buildings where no space heating is needed at night. The effective control is very important for the heating system in such buildings. In this paper, we studied a kind of new electrical floor heating system with ductless air supply and shape-stabilized PCM for thermal storage in order to overcome the shortcomings of the passive under-floor electric heating system with thermal storage. In this paper, we investigated its thermal performance by experiments and simulation, calculated the effects of various factors and discussed the application feasibility in different climate regions. The results show that the total electrical energy consumption was shifted from the peak period to the off-peak period, which would provide significant economic benefits because of the different day and night electricity tariffs. The system can be designed by choosing PCM with proper melting temperature and be controlled by varying velocity of air supply in different conditions

  12. Thermal Energy Storage for the Small Packaged Terminal Air Conditioning Unit. Quarterly progress report, February 2000

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-02-01

    To finalize the IceBear design for full-scale production, build two preproduction prototypes, and confirm cost projections for production and market analysis. The 5 tasks being carried out are: Task 1--Finalize thermal energy storage tank design; Task 2--Finalize internal heat exchanger; Task 3--Finalize refrigerant management and control components; Task 4--Preproduction prototype laboratory testing; and Task 5--Reporting.

  13. Electric energy storage - Overview of technologies

    International Nuclear Information System (INIS)

    Boye, Henri

    2013-01-01

    Energy storage is a challenging and costly process, as electricity can only be stored by conversion into other forms of energy (e.g. potential, thermal, chemical or magnetic energy). The grids must be precisely balanced in real time and it must be made sure that the cost of electricity is the lowest possible. Storage of electricity has many advantages, in centralized mass storages used for the management of the transmission network, or in decentralized storages of smaller dimensions. This article presents an overview of the storage technologies: mechanical storage in hydroelectric and pumped storage power stations, compressed air energy storage (CAES), flywheels accumulating kinetic energy, electrochemical batteries with various technologies, traditional lead acid batteries, lithium ion, sodium sulfur (NaS) and others, including vehicle to grid, sensible heat thermal storage, superconducting magnetic energy storage (SMES), super-capacitors, conversion into hydrogen... The different technologies are compared in terms of cost and level of maturity. The development of intermittent renewable energies will result in a growing need for mechanisms to regulate energy flow and innovative energy storage solutions seem well positioned to develop. (author)

  14. Audit helps power saving during generation of compressed air; Audit hilft Strom sparen bei der Erzeugung von Druckluft

    Energy Technology Data Exchange (ETDEWEB)

    Scherff, R. [Atlas Copco Kompressoren und Drucklufttechnik GmbH, Essen (Germany)

    2008-02-25

    Speed regulated compressors lower energy cost even in case of increasing air demand. When changing on oil-free working compressors further cost advantages are achievable e.g. no oil-contaminated products. (GL)

  15. Current status of and problems in ice heat storage systems contributing to improving load rate. Air conditioning system utilizing ice heat storage and building frame storage (Takenaka Corporation); Fukaritsu kaizen ni kokensuru kori chikunetsu system no genjo to kadai. Kori chikunetsu to kutai chikunetsu wo riyoshita kucho system

    Energy Technology Data Exchange (ETDEWEB)

    Inoue, Y.; Yoshitake, Y. [Takenaka Corp., Osaka (Japan)

    1998-02-01

    Development was made on a new air conditioning system, `building frame heat storage air conditioning system`, which combines an ice heat storage system with a building frame heat storage. With the building frame heat storage system, a damper is installed on an indoor device to blow cold air from the air conditioner onto slabs on the upper floor during nighttime power generating period. Heat is stored in beams, pillars and walls, and the shell absorbs and dissipates heat during daytime. Since general office buildings consume primary energy at 22.8% for heat source and 26.9% for transportation, which is greater, a natural coolant circulation type air conditioning system was developed as an air conditioning system for the secondary side. This made the building frame heat regeneration possible for the first time. With regard to heat storage quantity and heat dissipation quantity, the quantity of heat which can be stored during nighttime (10 hours) and dissipated during air conditioning using period in daytime (10 hours) is 80% of the stored heat quantity. This system was installed in a building in Kobe City. As a result of the measurement, it was found that indoor heat load reduction rate as a result of using the building frame heat storage was 24% or more in summer and 80% or more in winter. 7 figs., 2 tabs.

  16. Compressed air injection technique to standardize block injection pressures : [La technique d'injection d'air comprimé pour normaliser les pressions d'injection d'un blocage nerveux].

    Science.gov (United States)

    Tsui, Ban C H; Li, Lisa X Y; Pillay, Jennifer J

    2006-11-01

    Presently, no standardized technique exists to monitor injection pressures during peripheral nerve blocks. Our objective was to determine if a compressed air injection technique, using an in vitro model based on Boyle's law and typical regional anesthesia equipment, could consistently maintain injection pressures below a 1293 mmHg level associated with clinically significant nerve injury. Injection pressures for 20 and 30 mL syringes with various needle sizes ( 18G, 20G, 21 G, 22G, and 24G) were measured in a closed system. A set volume of air was aspirated into a saline-filled syringe and then compressed and maintained at various percentages while pressure was measured. The needle was inserted into the injection port of a pressure sensor, which had attached extension tubing with an injection plug clamped "off". Using linear regression with all data points, the pressure value and 99% confidence interval (CI) at 50% air compression was estimated. The linearity of Boyle's law was demonstrated with a high correlation, r = 0.99, and a slope of 0.984 (99% CI: 0.967-1.001). The net pressure generated at 50% compression was estimated as 744.8 mmHg, with the 99% CI between 729.6 and 760.0 mmHg. The various syringe/needle combinations had similar results. By creating and maintaining syringe air compression at 50% or less, injection pressures will be substantially below the 1293 mmHg threshold considered to be an associated risk factor for clinically significant nerve injury. This technique may allow simple, real-time and objective monitoring during local anesthetic injections while inherently reducing injection speed. Présentement, aucune technique normalisée ne permet de vérifier les pressions d'injection pendant les blocages nerveux périphériques. Nous voulions vérifier si une technique d'injection d'air comprimé, utilisant un modèle in vitro fondé sur la loi de Boyle et du matériel propre à l'anesthésie régionale, pouvait maintenir avec régularité les

  17. Radioactive air emissions notice of construction for deactivation of the PUREX storage tunnel number 2; FINAL

    International Nuclear Information System (INIS)

    JOHNSON, R.E.

    1999-01-01

    The Plutonium-Uranium Extraction (PUREX) Plant Storage Tunnel Number 2 (hereafter referred to as the PUREX Tunnel) was built in 1964. Since that time, the PUREX Tunnel has been used for storage of radioactive and mixed waste. In 1991, the PUREX Plant ceased operations and was transitioned to deactivation. The PUREX Tunnel continued to receive PUREX Plant waste material for storage during transition activities. Before 1995, a decision was made to store radioactive and mixed waste in the PUREX Tunnel generated from other onsite sources, on a case-by-case basis. This notice of construction (NOC) describes the activities associated with the reactivation of the PUREX Tunnel ventilation system and the transfer of up to 3.5 million curies (MCi) of radioactive waste to the PUREX Tunnel from any location on the Hanford Site. The unabated total effective dose equivalent (TEDE) estimated for the hypothetical offsite maximally exposed individual (MEI) is 5.6 E-2 millirem (mrem). The abated TEDE conservatively is estimated to account for 1.9 E-5 mrem to the MEI. The following text provides information requirements of Appendix A of Washington Administrative Code (WAC) 246-247 (requirements 1 through 18)

  18. Characterization and assessment of novel bulk storage technologies : a study for the DOE Energy Storage Systems program.

    Energy Technology Data Exchange (ETDEWEB)

    Huff, Georgianne; Tong, Nellie (KEMA Consulting, Fairfax, VA); Fioravanti, Richard (KEMA Consulting, Fairfax, VA); Gordon, Paul (Sentech/SRA International, Bethesda, MD); Markel, Larry (Sentech/SRA International, Bethesda, MD); Agrawal, Poonum (Sentech/SRA International, Bethesda, MD); Nourai, Ali (KEMA Consulting, Fairfax, VA)

    2011-04-01

    This paper reports the results of a high-level study to assess the technological readiness and technical and economic feasibility of 17 novel bulk energy storage technologies. The novel technologies assessed were variations of either pumped storage hydropower (PSH) or compressed air energy storage (CAES). The report also identifies major technological gaps and barriers to the commercialization of each technology. Recommendations as to where future R&D efforts for the various technologies are also provided based on each technology's technological readiness and the expected time to commercialization (short, medium, or long term). The U.S. Department of Energy (DOE) commissioned this assessment of novel concepts in large-scale energy storage to aid in future program planning of its Energy Storage Program. The intent of the study is to determine if any new but still unproven bulk energy storage concepts merit government support to investigate their technical and economic feasibility or to speed their commercialization. The study focuses on compressed air energy storage (CAES) and pumped storage hydropower (PSH). It identifies relevant applications for bulk storage, defines the associated technical requirements, characterizes and assesses the feasibility of the proposed new concepts to address these requirements, identifies gaps and barriers, and recommends the type of government support and research and development (R&D) needed to accelerate the commercialization of these technologies.

  19. Effect of Air Space in Storage Vials on Motility of Spermatozoa in Chilled Buck Semen

    Directory of Open Access Journals (Sweden)

    Magnus Paul K and Lali F Anand 1

    Full Text Available This study was conducted in order to find out the effect of air space on the top of glass vial in which semen is stored, on the motility of spermatozoa. 45 samples collected from two bucks over a span of 6 months were used for experiment. Goat milk extender was the diluent used. Two ml each of diluted semen after noting their initial motility was stored in 2 ml and 5 ml vials. Samples were stored at 5°C and motility of spermatozoa noted at 24 and 48 hours. Semen without air space was found to preserve the motility better than semen with air space on 24 and 48 hours of incubation. This could be better attributed to reactive oxygen species production by the spermatozoa, but further investigation is needed in this aspect to confirm it. [Veterinary World 2010; 3(9.000: 421-423

  20. Nonlinearity, Viscosity and Air-Compressibility Effects on the Helmholtz Resonant Wave Motion Generated by an Oscillating Twin Body in a Free Surface

    Science.gov (United States)

    Ananthakrishnan, Palaniswamy

    2012-11-01

    The problem is of practical relevance in determining the motion response of multi-hull and air-cushion vehicles in high seas and in littoral waters. The linear inviscid problem without surface pressure has been well studied in the past. In the present work, the nonlinear wave-body interaction problem is solved using finite-difference methods based on boundary-fitted coordinates. The inviscid nonlinear problem is tackled using the mixed Eulerian-Lagrangian formulation and the solution of the incompressible Navier-Stokes equations governing the viscous problem using a fractional-step method. The pressure variation in the air cushion is modeled using the isentropic gas equation pVγ = Constant. Results show that viscosity and free-surface nonlinearity significantly affect the hydrodynamic force and the wave motion at the resonant Helmholtz frequency (at which the primary wave motion is the vertical oscillation of the mean surface in between the bodies). Air compressibility suppresses the Helmholtz oscillation and enhances the wave radiation. Work supported by the ONR under the grant N00014-98-1-0151.