Energy Technology Data Exchange (ETDEWEB)

This article describes how a natural gas-fired combined cycle with increased firing temperature, reduced cooling air usage, improved component efficiencies, and cycle enhancements could achieve a lower heating value plant efficiency of greater than 60%. Today's gas turbine systems feature high fuel-to-electricity efficiencies. Efficiencies, on a lower-heating-value (LHV) basis, for large natural gas-fired combined-cycle systems for the utility market have been demonstrated at 54%. Even though manufacturers will make improvements in the 1990s, efficiency levels will reach a plateau. Cycle innovations and gas turbine design changes will achieve LHV efficiencies in the 60% range for natural gas-fired utility ...

Science.gov (United States)

This patent describes a method of improving the S0{sub 2} scrubbing efficiency of flue gas desulfurization scrubbers. It comprises conducting the scrubbing operation in such scrubbers in the presence of an oil-soluble surfactant.

Energy Technology Data Exchange (ETDEWEB)

Hydrogen piston engines can be simultaneously optimized for improved thermal efficiency and for extremely low emissions. Using these engines in constant-speed, constant-load systems such as series hybrid-electric automobiles or home cogeneration systems can result in significantly improved energy efficiency. For the same electrical energy produced, the emissions from such engines can be comparable to those from natural gas-fired steam power plants. These hydrogen-fueled high-efficiency, low-emission (HELE) engines are a mechanical equivalent of hydrogen fuel cells. HELE engines could facilitate the transition to a hydrogen fuel cell economy using near-term technology.

Energy Technology Data Exchange (ETDEWEB)

In order to establish the optimum fueling in a natural gas fueled dual fuel engine, tests were made for some operational parameters and their combination on the engine performances and the exhaust emissions. The results show that the gas oil quantity should be increased and gas oil injection timing should be advanced to suppress unburned hydrocarbon emission at middle and low output range, while the quantity should be reduced and the timing should be retarded to avoid onset of knock at high loads. The unburned hydrocarbon emission and the thermal efficiency are improved at the same load avoiding too lean natural gas premixture by restriction of intake charge air. However the improvement is limited because the ignition and initial combustion of pilot diesel fuel is deteriorated when the cylinder pressure is excessively lowered by throttling. ...

Energy Technology Data Exchange (ETDEWEB)

Many of the vertical hydrocarbon miscible floods in the Keg River carbonate reefs of the Rainbow Field are at a mature stage of reservoir depletion, and are characterized by thin oil sandwiches. Injection of a gas-blocking foam barrier into a gas cone had the potential to improve oil productivity. Experimental foam treatments were described for two wells, each in a different miscible flood well. One of the wells received foam in an aqueous solution to generate foam in-situ, and as a surface generated foam. These attempt were unsuccessful at improving well performance. The second well was injected with preformed foam only. This treatment reduced GOR and improved oil production over a 14 month period. Field experience from these field trials was expected to improve efficiency in planning, design, implementation and evaluation of future foam ...

Energy Technology Data Exchange (ETDEWEB)

Externally Fired Combined Cycles (EFCCs) can increase the amount of electricity produced from ash bearing fuels up to 40%, with overall powerplant efficiencies in excess of 45%. Achieving such high efficiencies requires high temperature-high pressure air heaters capable of driving modern gas turbines from gas streams containing the products of coal combustion. A pilot plant has been constructed in Kennebunk, Maine to provide proof of concept and evaluation of system components. Tests using pulverized Western Pennsylvania bituminous coal have been carried out since April, 1995. The ceramic air heater extracts energy from the products of coal combustion to power a gas turbine. This air heater has operated at gas inlet temperatures over 1,095 C and pressures over 7.0 atm without damage to the ceramic tube string components. Stable gas turbine ...

Energy Technology Data Exchange (ETDEWEB)

Traditional methane drainage methods, including conventional ventilation and boreholes drilled in the coal seam, are widely used in modern coal mining operation in China. However, it is often noted that the gas drainage presents low efficiency in most coal mines due to low permeability of the coal seam, which not only affects the safety, but also the productivity of the coal mine. This paper describes the development and application of the waterjet cutting system, which is used to create artificial fractures and increase the permeability of coal seam for the improvement of methane drainage in underground coal mines in China. According to underground monitoring, a significant improvement of methane drainage efficiency of up to 3 to 6 times over the traditional methods has been achieved. (author)

Energy Technology Data Exchange (ETDEWEB)

A survey has been made in relation with the improvement project intended of energy conservation, and reduction of global warming gas emission at the Bobovdol thermal power plant located in the suburb of Sofia, the capital of the Republic of Bulgaria. The existing Bobovdol power plant having a total capacity of 630 MW with three generators is a coal burning thermal power plant having been used already for 23 to 27 years, hence over-aged. The survey has discussed an improvement project of scrap-and-build type to make the plant a high-efficiency gas combined cycle power plant using gas turbines. The project calls for building 210-MW gas combined power generation facilities having 70-MW gas turbines, one each in three stages in 2007, 2012 and 2017. As a result of the discussions, the fuel consumption reducing rate was found ...

Energy Technology Data Exchange (ETDEWEB)

The industrial standard process for the purification of natural gas is to remove acid gases, mainly hydrogen sulfide and carbon dioxide, by the absorption and reaction of these gases with alkanolamines. The natural gas industry requires vapor-liquid equilibrium (VLE) data to develop more energy efficient amine mixtures. Some energy reductions have been realized in the past decade by applying such amine systems as hindered amines, methyldiethanolamine (MDEA), and MDEA based amine mixtures. However, the lack of reliable and accurate VLE data impedes the commercial application of these more efficient alkanolamine systems. The first objective of this project is to improve the accuracy of vapor-liquid equilibrium measurements at low hydrogen sulfide concentrations. The second objective is to make VLE measurements for amine mixtures. By improving the accuracy of the ...

International Nuclear Information System (INIS)

Despite the fact that there is still a potential to improve the efficiency of classic brown coal power plants by various measures from 36% to approx. 40-41%, the essential big increase of the efficiency to values of approx. 46% can only be achieved by the transition to combined gas and steam turbine processes. This means for the solid fuel brown coal that a gasification is integrated into the power plant process. The combined cycle power plant with an integrated brown coal gasification represents this new power plant concept. The applied High Temperature Winkler method (HTW-method) is an advancement of the Winkler method that works at environmental pressure and was developed by the Rheinbraun AG. (orig./DG).

Energy Technology Data Exchange (ETDEWEB)

The report reviews the activity during the fourth year of Gas Research Institute's Gas Appliance Technology Center program. Work on gas appliances involved a conceptual table-top multi-function oven, development of an indirect-fired conveyor oven, and performance comparisons of smooth cooktops. Performance-evaluation methods for commercial ovens were evaluated. Design improvements were made to a direct-fired conveyor oven and a pulse-combustion deep-fat fryer. Performance of common vents were studied, and a device was designed to allow incorporation of appliances with positive vent pressures into such systems. Standards-related work included draft-hood capacities, flexible corrugated-connector corrosion, and sediment trap efficiencies. Heating-related work comprised conceptual design of a vented baseboard heater and a centralized heat-transfer fluid system.

Energy Technology Data Exchange (ETDEWEB)

Preheating processed materials and combustion air can result in processing and fuel-efficiency gains in industrial smelting furnaces. For example, fuel consumption in reverberatory furnaces used in copper smelting would drop by as much as 63% at the same throughput by preheating the charge in a countercurrent mode to 1400/sup 0/F by exhaust gases that have an initial temperature of 2500/sup 0/F. Concurrent charge preheating would result in a maximum decrease of 46% in natural gas consumption. An analysis of these gains also provides equations for calculating investment returns and nomographs for optimizing charge-preheating temperatures for reverberatory furnaces.

Energy Technology Data Exchange (ETDEWEB)

The diesel engine is the most efficient device for converting chemical energy stored in liquid hydrocarbon fuels into useful work. Up to 50% of the energy in the fuel is converted into output shaft work. The modern diesel engine is twice as efficient as the early diesel engines and produces as much as sixty times as much power for a given cylinder size. These developments have, in recent years, been accompanied by a substantial reduction in the noxious elements in the exhaust gas so that engines are now, relatively speaking, ecologically clean. The developments have centred around exhaust gas turbocharging and improved fuel injection systems, but recent work on low-heat-rejection engines has resulted in significant advances in structural ceramics and in high-temperature lubricating oil, as well as an enhanced understanding of heat transfer in high-temperature combustion chambers. ...

British Library Electronic Table of Contents (United Kingdom)

This paper presents an investigation into the feasibility and potential advantages of a small scale Miller cycle natural gas engine for applications such as domestic combined heat and power systems. The Miller cycle engine is compared to a standard Otto cycle engine using cycle analyses and multidimensional simulation, and basic engine design implications are discussed. It is found that the Miller cycle engine has a potential for improved fuel efficiency, but at the cost of a reduced power to weight ratio. A fuel efficiency advantage of Formula Not Shown compared to a standard Otto cycle engine appears possible, however it is stated that further investigations, in particular into the topic of engine friction, are required in order to validate the findings.

Energy Technology Data Exchange (ETDEWEB)

The industrial standard process for the purification of natural gas is to remove acid gases, mainly hydrogen sulfide and carbon dioxide, by the absorption and reaction of these gases with alkanolamines. Inadequate data for vapor -- liquid equilibrium (VLE) hinder the industry from converting operations to more energy efficient amine mixtures and conserving energy. Some energy reductions have been realized in the past decade by applying such amine systems as ``hindered`` amines, methyldiethanolamine (MDEA), and MDEA based amine mixtures. However, the lack of reliable and accurate fundamental VLE data impedes the commercial application of these more efficient alkanolamine systems. The first project objective is to improve the accuracy of vapor -- liquid equilibrium measurements at low hydrogen sulfide concentrations. The second project objective is to measure the VLE for amine mixtures. By ...

Energy Technology Data Exchange (ETDEWEB)

The necessary conditions to design the methanol-fueled direct injection diesel engine with a reservoir type glow plug were cleared up from the points of view to prevent the air contamination and to use as an alternative oil for automotives, and as a result the good engine performance and emission characteristics could be obtained under the wide operating condition. The following facts were clarified: It is necessary to arrange the glow plug on the line of atomizing axis near the nozzle hole to ensure the ignitability under a wide operating condition. The reservoir type glow plug which reserves the premixed gas around the glow plug can shorten the ignition delay time and improve the combustion stability and the net thermal efficiency in the light load region. The combustion in the light load region was accelerated, NO{sub x} emission rate was suppressed and moreover, the net thermal efficiency and ...

Energy Technology Data Exchange (ETDEWEB)

The productivity characteristics of perforated gas well are investigated for the first time under real conditions considering drilling damage, perforation compacted zone and anisotropy in this paper. A non-linear finite element model for non-Darcy flow in perforated gas reservoir is built to consider the effects of twelve factors on productivity ratio (PR) of perforated gas well. The nomographs for two cases are presented in this paper. Compared with previous works, the following results are found: (1) the effects of drilling damage and perforation diameter on PR of gas well are more remarkable than that in oil well; (2) any perforation phase may be the best or the worst as to perforating gas well, which depends on anisotropy, drawdown and that whether or not perforations are beyond drilling damage zone; (3) the increase in perforation length hardly improve PR ...

International Nuclear Information System (INIS)

The outlook for natural gas (from both supply and price perspectives) has improved dramatically since the late 1970s, and significant advances have been made in electrical generation technologies which use gas. For example, gas-fired combined-cycle turbine units have become even more efficient and reliable. These units can be installed quickly (12 to 24 months versus 8 to 15 years for coal and nuclear units), and they may be brought on-line in small incremental blocks. This modular construction feature offers greater flexibility to utility planners, and the relatively low capital cost of combined-cycle units reduces financial uncertainties. The purpose of this chapter is to compare two electric power generating options, a new coal-fired powerplant and a new natural gas fired combined-cycle unit, from both economic and environmental perspectives. The comparison ...

Energy Technology Data Exchange (ETDEWEB)

Short communication

Energy Technology Data Exchange (ETDEWEB)

The conference paper gives a short description of the strategies within Statoil Gas Transport for pipeline condition monitoring and control. This is done for ensuring that the pipeline integrity can be maintained during all phases from construction to operation. Efficient condition monitoring and control can only be performed if the total pipeline integrity is taken into consideration such as design conditions, experience, environmental information, and general improved knowledge or the like for determining the requirement of inspection. Such philosophy will ensure the pipeline integrity better as corrective actions can be taken at a very early stage before any damage to the pipeline system have developed. 1 fig.

Energy Technology Data Exchange (ETDEWEB)

Biomass is one of the main natural resources in Sweden. The present low-CO{sub 2} emission characteristics of the Swedish electricity production system (hydro and nuclear) can be retained only by expansion of biofuel applications for energy purposes. Domestic Swedish biomass resources are vast and renewable, but not infinite. They must be utilized as efficiently as possible, in order to make sure that they meet the conditions for sustainability in the future. Application of efficient power generation cycles at low costs is essential for meeting this challenge. This applies also to municipal solid waste incineration with energy extraction, which should be preferred to its dumping in landfills. Hybrid dual-fuel combined cycle units are a simple and affordable way to increase the electric efficiency of biofuel energy utilization, without big investments, uncertainties or loss of reliability arising from complicated ...

Energy Technology Data Exchange (ETDEWEB)

Two natural gas/diesel dual fuel conversion systems for the Detroit Diesel 6V-71 transit bus engine were described. The basic concept of a dual fuel engine was to operate a diesel engine with both liquid fuel injection and a lean premixed gas mixture. The engine achieved high efficiency due to the high compression ratio typical of the diesel engine. Test results were obtained using three different calibrations on one engine. The objectives were to match existing engine performance with improved emissions and better overall fuel economics. Results showed that overall, engine conversion has both economic and emissions advantages over a straight diesel engine. However, the durability and in-use applicability of the system remains to be demonstrated with an in-bus demonstration project.. 3 tabs., 4 figs.

Energy Technology Data Exchange (ETDEWEB)

Pilot plant tests have been conducted to evaluate sodium thiosulfate as an oxidation inhibition additive in five lime/limestone slurry flue gas desulfurization processes. It was found that the oxidation rate of absorbed sulfur dioxide (SO)/sub 2/ was reduced by more than 50 percent in the presence of 100 to 200 ppm of thiosulfate ion in the scrubbing slurry. Calcium sulfate dihydrate (gypsum) scaling was eliminated and the unsaturated (with respect to gypsum) operation mode was maintained by the addition of sodium thiosulfate. Other benefits of sodium thiosulfate addition observed at the pilot plant included improvement in solids dewatering properties for limestone processes and improvement in SO/sub 2/ removal efficiency for magnesium-enhanced lime/limestone processes.

Energy Technology Data Exchange (ETDEWEB)

The article gives results of pilot-plant tests to evaluate sodium thiosulfate as an oxidation-inhibition additive in five lime/limestone slurry flue-gas desulfurization processes. It was found that the oxidation rate of absorbed SO/sub 2/ was reduced by more than 50% in the presence of 100-200 ppm of thiosulfate ion in the scrubbing slurry. Calcium sulfate dihydrate (gypsum) scaling was eliminated and the unsaturated (with respect to gypsum) operation mode was maintained by the addition of sodium thiosulfate. Other benefits of sodium thiosulfate addition observed at the pilot plant included improvement in solids dewatering properties for limestone processes and improvements in SO/sub 2/ removal efficiency for magnesium-enhanced lime/limestone processes.

Energy Technology Data Exchange (ETDEWEB)

Reserve appreciation, also called reserve growth, is the increase in the estimated ultimate recovery (the sum of year end reserves and cumulative production) from fields subsequent to discovery from extensions, infield drilling, improved recovery of in-place resources, new pools, and intrapool completions. In recent years, reserve appreciation has become a major component of total U.S. annual natural gas reserve additions. Over the past 15 years, reserve appreciation has accounted for more than 80 percent of all annual natural gas reserve additions in the U.S. lower 48 states (Figure 1). The rise of natural gas reserve appreciation basically came with the judgment that reservoirs were much more geologically complex than generally thought, and they hold substantial quantities of natural gas in conventionally movable states that are not recovered by typical well spacing and vertical ...

Energy Technology Data Exchange (ETDEWEB)

A literature review on gasification of lignocellulosic biomass in various types of fluidized bed gasifiers is presented. The effect of several process parameters such as catalytic bed material, bed temperature and gasifying agent on the performance of the gasifier and quality of the producer gas is discussed. Based on the priorities of researchers, the optimum values of various desired outputs in the gasification process including improved producer gas composition, enhanced LHV, less tar and char content, high gas yield and enhanced carbon conversion and cold gas efficiency have been reported. The characteristics and performance of different fluidized bed gasifiers were assessed and the obtained results from the literature have been extensively reviewed. Survey of literature revealed that several industrial biomass gasification plants using fluidized beds are ...

Energy Technology Data Exchange (ETDEWEB)

Better understanding and modelling of three-phase flow through porous media is of great interest, especially for improved oil recovery methods such as gas injection processes. Early theoretical and experimental studies have already demonstrated that the wettability characteristics of the solid surface and the spreading characteristics of the fluid system hold the key roles. This observation is confirmed by our theoretical results using DLP theory on the stability and the thickness of static oil films. In most of the works related to three-phase flow processes, homogeneous wettability is assumed. There exist only a few studies demonstrating the tremendous impact of the wettability heterogeneities on gas injection. The objective of the present work is twofold: to demonstrate the effect of small scale wettability heterogeneities on gas injection efficiency, and to develop a tool to ...

Energy Technology Data Exchange (ETDEWEB)

In January 1981, a dual-fuel engine of type 8L52/55 ADG, with the highest cylinder rating of all four-stroke gas engines currently available, succesfully completed its test run on M.A.N.s test bed at Augsburg. The engine can be operated either on Diesel oil or on gas and pilot oil and can be switched from Diesel to gas operation or vice versa at any load during operation. In gas operation, the engine works on the pilot injection principle. By changing from pulse-pressure to constant-pressure turbocharging, matching the charge-air pressure, improving mixture formation and optimising the injection system, M.A.N. has succeeded in achieving a high power output while reducing the heat consumption in gas operation almost to its level in Diesel operation. A close look is taken at the design features which distinguish the dual-fuel engine from the 52/55 A Diesel engine, ...

Energy Technology Data Exchange (ETDEWEB)

Oregon State University (OSU) and the Pacific Northwest National Laboratory (PNNL) were funded by the U.S. Department of Energy to conduct research focused on resolving the key technical issues that limited the deployment of efficient and extremely compact microtechnology based heat actuated absorption heat pumps and gas absorbers. Success in demonstrating these technologies will reduce the main barriers to the deployment of a technology that can significantly reduce energy consumption in the building, automotive and industrial sectors while providing a technology that can improve our ability to sequester CO{sub 2}. The proposed research cost $939,477. $539,477 of the proposed amount funded research conducted at OSU while the balance ($400,000) was used at PNNL. The project lasted 42 months and started in April 2001. Recent developments at the Pacific Northwest National Laboratory and Oregon State University suggest that ...

Energy Technology Data Exchange (ETDEWEB)

A thermal and economic study, carried on by using the first and second law of thermodynamics concepts demonstrated the economic feasibility of the cogeneration system, and proposed modifications to be done in the studied cryogenic plant, a typical T-240 NA MPL3 plant. The thermodynamic analysis showed that the second law efficiency of the processes could be improved, together with a 12% electric energy consumption reduction. Four cogeneration schemes were analyzed with both the first and second laws of thermodynamics and, then, the economic analysis was performed. Rankine, Brayton, Otto and Combined gas-steam basic cycles were used in this analysis.The combined gas-steam cycle was shown to be more economically feasible than others. Thermal and electric loads were well balanced, resulting in a higher second law efficiency. Although the initial investment for the modification was ...

Energy Technology Data Exchange (ETDEWEB)

Section 127 of the Energy Policy Act requires that the Department of Energy (DOE) prepare a report to Congress on the potential for the development and commercialization of appliances that substantially exceed the present federal or state efficiency standards. Candidate high-efficiency appliances must meet several criteria including: the potential exists for substantial improvement (beyond the minimum established in law) of the appliance`s energy efficiency; electric, water, or gas utilities are prepared to support and promote the commercialization of such appliances; manufacturers are unlikely to undertake development and commercialization of such appliances on their own, or development and production would be substantially accelerated by support to manufacturers. This report describes options to improve the efficiency of residential ...

Energy Technology Data Exchange (ETDEWEB)

This paper deals with the combustion process of the turbocharged dual-fuel engine with regard to improvement to thermal efficiency and exhaust gas emissions. It describes the method of charge-air control used to achieve optimal operation in either a pure diesel engine or a gas engine using the pilot-ignition process (dual-fuel principle). The change-over from gas to diesel operation and vice versa can be made automatically even under full load, i. e. the engine can be changed over from one mode of operation to the other without interruption. The exhaust gas constituents emitted by the dual-fuel engine are less detrimental to the environment than those of other internal-combustion engines: CO is hardly present at all; NOx is no higher than that from good diesel engines, or even lower; SO/sub 2/ does not occur since the natural gas, which is ...

Energy Technology Data Exchange (ETDEWEB)

This paper explains technologies for turbo chargers used in light cars. Light car engine turbo chargers have been given various improvements responding to needs of the market. Since ball bearings have less mechanical loss than sliding bearings, and enhances greatly the turbo efficiency, they are used in some high performance engines of light cars. While the conventional ball bearing has used high hardness bearing steel, the new standard cars started using ceramic ball. The currently used light car gasoline engines are divided into two kinds, serial three-cylinder type and serial four-cylinder type, either having merits and demerits. The new twin entry turbo developed by IHI arranges divided exhaust gas ports above and below to simplify the manifold shape, and realizes smooth flow by twisting the exhaust gas flow path inside the turbine housing. This makes the dynamic pressure of the exhaust ...

Energy Technology Data Exchange (ETDEWEB)

Beside sucker-rod-type pumps and submersible centrifugal pumps, excentric screw pumps (so-called progressing cavity pumps) belong to standard conveyors in the production of crude oil. The authors of the contribution under consideration present the further development of excentric screw pumps with respect to the reduction of fluid levels in gas wells. This further development is based on a co-operation between the operator (Rohoel Aufsuchungs AG (Gampern, Austria)), the pump supplier (NETZSCH Oilfield Products GmbH (Selb, Federal Republic of Germany)) and the Institute for Process Technologies and Machinery at the University of Erlangen-Nuernberg (Federal Republic of Germany). The authors report on first attempts with the excentric screw pump at Weizberg (Federal Republic of Germany), material investigations at the University of Erlangen-Nuernberg, optimization of pump components and pump systems as well as on the optimization of the entire drainage process. ...

Energy Technology Data Exchange (ETDEWEB)

The Coal Fired Combined Cycle (CFCC) is the unique powerplant concept developed under the leadership of the General Electric Company to provide a direct coal-burning gas turbine and steam turbine combined cycle powerplant. On the basis of previous studies and confirming work under this contract, General Electric continues to believe that the CFCC approach offers important advantages over alternate approaches: higher powerplant efficiency in the combustor temperature range of interest; reduced combustor/steam generator corrosion potential, due to low fluid-bed tube temperature (as contrasted to the air in tube cycle); and increased gas turbine bucket life from improved material protection systems. The objective of this program is to evaluate the coal fired combined cycle powerplant conceptual design, and to conduct a supporting development program. The supporting development is required for evaluating ...

Energy Technology Data Exchange (ETDEWEB)

The purpose of the project is to further develop a Danish natural gas reformer system including optimisation of subsystems and the overall system consisting of a natural gas reformer and fuel cell CHP generator. This will contribute to the evaluation of to what extend Denmark shall develop small reformer units for PEM fuel Cells. In the project a reformer system with a high degree of automatic control has been build that fulfils the CHP requirements to operation time, dynamics etc. This work, with a FP05 reformer unit, has given valuable results concerning the possibilities and limitations of the reformer technology for CHP usage. It is important that the reformer and fuel cell units are designed with matching yields to optimise efficiency, turn-down start-up time etc. The burner that delivers heat for the steam reaction shall be able to use natural gas as fuel. This gives the possibility of using ...

Energy Technology Data Exchange (ETDEWEB)

Hydrogen (H{sub 2}) emissions characteristics of H{sub 2}-diesel dual fuel engine were measured using a 2004 turbocharged heavy-duty diesel engine with H{sub 2} supplemented into the intake air. The emissions of H{sub 2} were measured using an Electron Pulse Ionization (EPI) Mass Spectrometer (MS). The effect of the amount of H{sub 2} added, the engine load, and diesel fuel flow rates on the emissions of H{sub 2} and its combustion efficiency in the engine were investigated. The addition of H{sub 2} under high load operation was notable for its ability to obtain high H{sub 2} combustion efficiency and improve brake thermal efficiency. However, the addition of H{sub 2} at low load resulted in high emissions of H{sub 2} due to the failure to initiate and support a sufficiently vigorous flame for the complete combustion of H{sub 2} present outside the diesel spray plume. The maximum H{sub 2} emissions of ...

Energy Technology Data Exchange (ETDEWEB)

Tests to measure the maximum horsepower of commercial vehicles converted for use with natural gas fuel indicate a reduction of approximately 20% in horsepower compared with gasoline-driven vehicles. This reduction in horsepower resulting from the use of gas is due basically to the lower thermal efficiency of the cycle of natural gas compared with that of gasoline and to its lower volumetric efficiency, since natural gas is injected into the combustion chamber in gaseous form, unlike gasoline, in which part of the fuel entering the cylinder is in the liquid phase. Natural gas used as a fuel generates lower quantities of air pollutants, particularly unburned hydrocarbons (HCs) and carbon monoxide (CO). Despite the downside of reduced horsepower, the use of natural gas as a fuel for automotive vehicles equipped with ...

Energy Technology Data Exchange (ETDEWEB)

Using an economic perspective, it is possible to make a case for green buildings and green development practices by placing emphasis on Energy Efficiency and Environmental Design. Several case studies have demonstrated that green buildings save money through reduced consumption of natural resources, electricity and gas both at the building site and at the source of energy. Sound environmental practices and energy efficiency measures improve the environmental conditions throughout the state by reducing power plant emissions and reducing operations and maintenance budgets in the state. The author presented a case study where a green development project was guided and monitored using the Environmental Performance Rating System called Leadership in Energy and Environmental Design (LEED), version 2.0. The work was registered to achieve LEED certification. A brief study on current construction related costs ...

Energy Technology Data Exchange (ETDEWEB)

This report prepared for the Swiss Federal Office of Energy (SFOE) describes the practical realisation and testing of a heat recovery system based on a one-stage organic Rankine cycle with R134a as the working fluid. The waste heat has a temperature of 95 {sup o}C and originates from a gas engine that powers a small co-generation plant fuelled with biogas produced on-site. Two similar cycles have been built, ORC1 with one and ORC2 with two turbines. Only ORC1 has been tested so far. The maximum efficiency measured in these tests was 6.64% (theoretical Carnot-efficiency: 17 %) and the electric power output was 5.0 kW. The problems encountered during commissioning are described and recommendations for further improvements are given.

Science.gov (United States)

A new class of hybrid organic-inorganic materials, and methods of synthesis, that can be used as a proton exchange membrane in a direct methanol fuel cell. In contrast with Nafion.RTM. PEM materials, which have random sulfonation, the new class of materials have ordered sulfonation achieved through self-assembly of alternating polyimide segments of different molecular weights comprising, for example, highly sulfonated hydrophilic PDA-DASA polyimide segment alternating with an unsulfonated hydrophobic 6FDA-DAS polyimide segment. An inorganic phase, e.g., 0.5 5 wt % TEOS, can be incorporated in the sulfonated polyimide copolymer to further improve its properties. The new materials exhibit reduced swelling when exposed to water, increased thermal stability, and decreased O.sub.2 and H.sub.2 gas permeability, while retaining proton conductivities similar to Nafion.RTM.. These improved properties may allow direct methanol fuel ...

Energy Technology Data Exchange (ETDEWEB)

Low-dust flue gases can be washed efficiently of SO/sub 2/, and the flue gas heat can be utilized. The residual heat fraction still required by the process is characterized by a temperature of 15/sup 0/K above the temperature of the purified flue gas. Marketable crystalline ammonium sulfate is produced. The high efficiency and low heat consumption are achieved by combining all process stages in a single, fully integrated cycle process free of heat and materials losses. The process is characterized by high efficiency, low investment and operating costs, recovery of thermal energy, and production of an ammonium sulfate fertilizer.

Science.gov (United States)

The present study attempts to use hydrogen peroxide solution to humidify Ca(OH)(2) particles to enhance the absorption of SO(2) to achieve higher removal efficiency and to solve the valuable reuse of the reaction product in the semidry flue gas desulfurization (FGD) process. Experiments were carried out to examine the effect of various operating parameters including hydrogen peroxide solution concentration, Ca/S molar ratio and approach to adiabatic saturation temperature on SO(2) removal efficiency in a laboratory scale spray reactor. The product samples were analyzed to obtain semi-quantitative measures of mineralogical composition by X-ray diffraction (XRD) with reference intensity ratio (RIR) method and the morphology of the samples was examined by scanning electron microscope (SEM). Compared with spraying water to humidify Ca(OH)(2), SO(2) removal efficiency was improved ...

Energy Technology Data Exchange (ETDEWEB)

Gas turbine component protection remains essential but environmental regulations emphasize the gas-turbine efficiency. Heating and cooling are features often integrated into the GI air intake packages to provide the optimum operating conditions. This paper describes modern inlet air treatment systems and discusses their effectiveness. (author)

Energy Technology Data Exchange (ETDEWEB)

We report the performance of a micro gas turbine on biomass producer gas and mixtures of biomass producer gas with natural gas. The micro gas turbine delivers full power on gas mixtures with a heating value of at least 15 MJ/Nm{sup 3}. For gas of lower heating value, the maximum fuel gas flow limits the attainable power. The lower limit for stable operation is about 8 MJ/Nm{sup 3}. The gross efficiency of the micro gas turbine depends on output power but not on the gas heating value, within our measurement accuracy. Above 70% of full power, emissions of CO and NO are 40 and 10 times lower than those of a gas engine of similar size. At part load below 70% of full power, the micro gas turbine burner switches to a ...

Energy Technology Data Exchange (ETDEWEB)

In this work, the thermal performance of a conventional collector is improved by inserting porous substrates at the inner walls of the collector tubes. The porous substrates improve the convective heat transfer coefficient between the tube wall and the fluid. This improvement is investigated numerically and its effects on the efficiency and the useful gain of the collector are evaluated. It is found that inserting the porous substrate may raise the collector efficiency considerably, especially at high values of the overall heat loss coefficient.

Energy Technology Data Exchange (ETDEWEB)

The objective of this paper is to demonstrate how market forces, operating in an increasingly competitive energy market, are a preferred route to achieving environmental and energy efficiency benefits other than those which can be achieved through a managed approach adopted by many Governments. It will show, through examples, how electricity is a catalyst for change at several levels in business, the community and the general economy. Many governments` attempts to introduce `vertically-structured` energy saving programmes have failed to realise the benefits of inter-energy substitution. Frequently, programmes are based on the principles of demand-side management within a single energy sector, and they have been implemented by government bodies which have adopted an interventionist as opposed to free market approach to achieve savings in carbon dioxide emissions. Studies world-wide have shown how increased use of electricity, particularly in industry, can be a major ...

Energy Technology Data Exchange (ETDEWEB)

The effect of adding hydrogen to methane as a fuel for spark ignited engines has been extensively investigated. Both the possibility of adding a limited amount of hydrogen as well as equal amounts of hydrogen and carbon dioxide to natural gas has been investigated. A 10 vol% addition of hydrogen to the natural gas caused a reduction in UHC of approximately 40%, and an increase in efficiency of approximately three percentage points at the test engine. It is unknown if the gain is representative for large engines. Similar results for UHC reduction and efficiency were obtained for combined hydrogen and carbon dioxide addition. The carbon dioxide was added by exhaust gas recirculation. However, the price of hydrogen, makes this idea uneconomical even when carbon dioxide is readily available through recirculation of engine exhaust. Adiabatic prereforming may be used to convert natural ...

Energy Technology Data Exchange (ETDEWEB)

Given that fossil fuel fired power plants are among the largest and most concentrated producers of CO{sub 2} emissions, recovery and sequestration of CO{sub 2} from the flue gas of such plants has been identified as one of the primary means for reducing anthropogenic CO{sub 2} emissions. In this study, ALSTOM Power Inc. (ALSTOM) has investigated several coal fired power plant configurations designed to capture CO{sub 2} from effluent gas streams for use or sequestration. Burning fossil fuels in mixtures of oxygen and recirculated flue gas (made principally of CO{sub 2}) essentially eliminates the presence of atmospheric nitrogen in the flue gas. The resulting flue gas is comprised primarily of CO{sub 2}. Oxygen firing in utility scale Pulverized Coal (PC) fired boilers has been shown to be a more economical method for CO{sub 2} capture than amine scrubbing (Bozzuto, et al., 2001). ...

Science.gov (United States)

Development efforts have been undertaken to improve the processing and structural efficiencies of

UK PubMed Central (United Kingdom)

BackgroundSwine is an important agricultural commodity and biomedical model. Manipulation of the pig genome provides opportunity to improve production efficiency, enhance disease...Full Text Available

International Nuclear Information System (INIS)

The performance of the gas-jet transport system coupled to the RIKEN gas-filled recoil ion separator GARIS was investigated using 255No produced in the 238U(22Ne, 5n)255No reaction. Alpha particles of 255No separated with GARIS and transported by the gas-jet system were measured with a rotating wheel apparatus for ? spectrometry under low background condition. The high gas-jet efficiencies of about 75% were independent of the recoil ranges of 255No in the gas-jet chamber. The present results suggest that the GARIS/gas-jet system is a promising tool for the next-generation superheavy element chemistry: (1) the background radioactivities of unwanted reaction products are strongly suppressed, (2) the intense beam is absent in the gas-jet chamber and hence the high gas-jet efficiency ...

Energy Technology Data Exchange (ETDEWEB)

The purpose of this project is to demonstrate targeted infill and extension drilling opportunities, better determinations of oil-in-place, methods for improved completion efficiency and the suitability of waterflooding in Red River and Ratcliffe shallow-shelf carbonate reservoirs in the Williston Basin, Montana, North Dakota and South Dakota. Improved reservoir characterization utilizing three-dimensional and multi-component seismic are being investigated for identification of structural and stratigraphic reservoir compartments. These seismic characterization tools are integrated with geological and engineering studies. Improved completion efficiency is being tested with extended-reach jetting lance and other ultra-short-radius lateral technologies. Improved completion efficiency, additional wells at closer spacing and better estimates of ...

Science.gov (United States)

The purpose of this project is to demonstrate targeted infill and extension drilling opportunities, better determinations of oil-in-place, methods for improved completion efficiency and the suitability of waterflooding in Red River and Ratcliffe shallow-shelf carbonate reservoirs in the Williston Basin, Montana, North Dakota and South Dakota. Improved reservoir characterization utilizing three-dimensional and multi-component seismic are being investigated for identification of structural and stratigraphic reservoir compartments. These seismic characterization tools are integrated with geological and engineering studies. Improved completion efficiency is being tested with extended-reach jetting lance and other ultra-short-radius lateral technologies. Improved completion efficiency, additional wells at closer spacing and better estimates of ...

Energy Technology Data Exchange (ETDEWEB)

The purpose of this project is to demonstrate targeted infill and extension drilling opportunities, better determination of oil-in-place, methods for improved completion efficiency and the suitability of waterflooding in certain shallow-shelf carbonate reservoirs in the Williston Basin, Montana, North Dakota and South Dakota. Improved reservoir characterization utilizing 3-dimensional (3D) is being investigated for identification of structural and stratigraphic reservoir compartments. These seismic characterization tools are integrated with geological and engineering studies. Improved completion efficiency is being tested with short lateral and horizontal drilling technologies. Improved completion efficiency, additional wells at closer spacing and better estimates of oil-in- place will result in additional oil production by primary and ...

Energy Technology Data Exchange (ETDEWEB)

The purpose of this project is to demonstrate targeted infill and extension drilling opportunities, better determinations of oil-in- place, methods for improved completion efficiency and the suitability of waterflooding in certain shallow-shelf carbonate reservoirs in the Williston Basin, Montana, North Dakota and South Dakota. Improved reservoir characterization utilizing 3-dimensional (3-D) and multi- component seismic are being investigated for identification of structural and stratigraphic reservoir compartments. These seismic characterization tools are integrated with geological and engineering studies. Improved completion efficiency is being tested with short- lateral and horizontal drilling technologies. Improved completion efficiency, additional wells at closer spacing and better estimate of oil-in-place will result in additional oil ...

Energy Technology Data Exchange (ETDEWEB)

This article reports on the world's first gas turbine to top 40% thermal efficiency in simple cycle and is now operating commercially as part of a natural-gas-fired combined-cycle cogeneration (CC) plant serving the Ottawa Health Sciences Center, Ottawa, Ont, Canada. Owned and operated by TransAlta Energy Corp, Calgary, Alta, the CC plant supplies steam and hot and chilled water to the health center and another thermal user while the electricity is sold to Ontario Hydro. Part of the project included the conversion of 15-psig steam-carrying equipment to hot-water service. Commercial success of this installation heralds a new era in the application of efficient gas turbines for power generation.

International Nuclear Information System (INIS)

... Union (INTAS), Brussels (Belgium) Science and Technology Center in Unkraine,

Energy Technology Data Exchange (ETDEWEB)

Elf Aquitaine, a major international oil and gas company, has recently undergone a thorough reengineering of its research and development in exploration and production division. The aim of this reengineering, was to align the company R&D with its business strategy, and also to give a clear picture of two major features for a R&D portfolio: a duration profile (short, median or long term?) and a partnership profile (do it yourself, cooperate, outsource or let do elsewhere?). In short, we were trying to answer a basic question: How can we adapt our R&D to a durable context of low oil price (eg 15 $/bbl)? In our opinion, two preliminary statements ought to be made when dealing with the above issue. Firstly, R&D does not contribute equally to the factors of increased profitability, although it is certainly a major contributor to some of them (like obtaining new ventures, reducing costs, discovering new reserves out of current acreage, or ...

Energy Technology Data Exchange (ETDEWEB)

One of the unsolved problems of the natural gas dual fuel engine is that there is too much exhaust of Total Hydrogen Carbon(THC) at a low equivalent mixture ratio. To fix it, a natural gas mixed with hydrogen was applied to engine test. The results showed that the higher the mixture ratio of hydrogen to natural gas, the higher the combustion efficiency. And when the amount of the intake air is reached to 90% of WOT, the combustion efficiency was promoted. But, like a case making the injection timing earlier, the equivalent mixture ratio for the nocking limit decreases and the produce of NOx increases. 5 refs., 9 figs., 1 tab.

British Library Electronic Table of Contents (United Kingdom)

The use of natural gas in China is still relatively immature, as gas production only supplies a low percentage of the domestic energy system. In contrast, Chinese economy mainly relies on coal with a 67% share of the total primary energy supply. The environmental impact from this high coal dependence is significant and planners have sought for cleaner energy sources. Natural gas is both cleaner and generally more efficient than coal and gas consumption is rising quickly due to these facts. The growth tendency indicates that natural gas will become an important substitution for coal in some parts of the Chinese primary energy consumption. To quantify this tendency, this paper uses a system dynamics model to create a possible outlook. The results show that the gas consumption in China will c...

Energy Technology Data Exchange (ETDEWEB)

Today, as a result of increase in oil prices, limited fossil fuel resources, environmental consideration and global warming, the methyl ester fuels have been focused on alternative fuels. Methyl ester fuels can be used more efficiently in low heat rejection engines (LHR), in which the temperature of combustion chamber is increased by creating a thermal barrier. In this study, the piston, cylinder head, exhaust and inlet valves of a diesel engine were coated with the ceramic material Al{sub 2}O{sub 3}-TiO{sub 2} by the plasma spray method. Thus, a thermal barrier was provided for the parts of the combustion chamber with these coatings. The effects of corn oil methyl ester that produced by the transesterification method, and No. D2 fuels' performance and exhaust emissions' rate were studied by using equal in every respect coated and uncoated engines. Tests were performed on the uncoated engine, and then repeated on the coated engine and the results ...

Science.gov (United States)

Measurements of PEM fuel cell device performance were made with different gas inlet temperatures and relative humidity using a newly-designed test fixture. Significant improvement in device performance was observed when the fuel inlet temperature was increased above the operating temperature of the cell. These measurements were then correlated to a model to describe energy and mass transport processes. Proton exchange membrane (PEM), fuel cells--the focus of this study--use an ion conducting polymer, especially polyperfluorosulfonic acid materials. These polymer materials, when imbibed with water, exhibit solution-like properties, but because the anions are chemically bound to the polymeric structure, the electrolyte is contained. Importantly, product water removal is simplified, as electrolyte dilution is not a concern. However, the proton transport rate is a function of the polymer geometry, which is set, in part, by the polymer water ...

International Nuclear Information System (INIS)

Recognizing the importance of energy as a vital component in economic development, the Taiwanese government has been continuously revising its energy policy, seeking to balance economic development, energy supply, and environmental protection (3E). Some measures, in an attempt to achieve the 3E balance, were previously implemented in Taiwan; nevertheless, some unresolved issues departing from certain core principles of Taiwan's sustainable energy policy and an international initiative for a low carbon society remain. The aim of this paper is to examine the energy supply and demand structure of Taiwan and the present status of individual energy carriers (including coal, petroleum, natural gas and electricity). In addition, it investigates the current energy policy framework and its implementation in Taiwan, identifies unresolved issues regarding sustainable energy development, and formulates key policy solutions for certain identifiable problems to enable the ...

Energy Technology Data Exchange (ETDEWEB)

The conversion of off-peak surplus electricity into peak electricity through an electrolyzer, hydrogen storage, and fuel cell energy storage system was discussed. Development efforts in high pressure alkaline electrolysis and Proton-Exchange Membrane (PEM) fuel cells have improved the near-term viability of these systems. Potential use of wind turbines and other renewable energy-based generation systems, through hydrogen-based energy storage, were discussed as a new supply of surplus electricity. An integrated set of nomographs were presented for providing quick estimates of peak electricity costs derived from an electrolyzer/hydrogen fuel cell system. The nomographs allowed first order cost comparisons of centralized versus distributed hydrogen energy systems considering trade-offs between production economies of scale and hydrogen storage and transport costs. Use of the nomographs to compare centralized and dispersed systems was demonstrated. Results showed that ...

Science.gov (United States)

A new fabrication process is being developed which significantly improves the efficiency of metal-semiconductor solar cells. The resultant effect, a marked increase in the open-circuit voltage, is produced by the addition of an interfacial layer oxide on the semiconductor. Cells using gold on n-type gallium arsenide have been made in small areas (0.17 sq cm) with conversion efficiencies of 15% in terrestrial sunlight.

Energy Technology Data Exchange (ETDEWEB)

Three different configurations of cylindrical submerged media anaerobic reactors (SMARs) with packing volumes of 85 items were operated at 35 C for 415 days with COD loading rates varying from 1 to 12 g/l/d and three retention times of 0.5, 1, and 2 days. A synthetic waste consisting of a milk solution with a mineral supplement was used for the feed. Tracer studies on clean-bed and dirty-bed SMARs indicate that reactor configuration, biogas mixing, and biomass accumulation all have a significant effect on SMAR hydraulics and cause short-circuiting. Based on the isothermal energy dissipation theory, the higher hydrostatic pressures resulting from higher SMAR heights increases self-induced biogas mixing and improves the contact efficiency between substrate and organisms. Based on TCOD removal rate, the tallest SMAR performed slightly better at COD loading rates above 4/g/l/d. At COD loading rates equal to or below 4 g/l/d, there was little ...

British Library Electronic Table of Contents (United Kingdom)

Continually rising energy prices in global markets highlights a serious concern about the need to improve energy efficiency and the efficiency in energy sector in many countries. China, as one of the fastest growing countries in the world and the largest coal producer, has high coal consumption but a low recovery rate of coal utilization. Coal efficiency and the efficiency in coal industry have therefore attracted a great deal of attention from Chinese policy makers, coal firms and academics. This study attempts to compare the relative technical efficiency performance of listed coal mining companies in China and the US using CCR and BCC models in the advanced DEA linear programming. The results show that the level of relative efficiency in Chinese coal mining enterprises, regardless of tot...

Energy Technology Data Exchange (ETDEWEB)

The natural gas industry has proposed an increase in the DOE gas R&D budget from about $100 million to about $250 million per year for each of the next 10 years. The proposal includes four programs: natural gas supplies, fuel cells, natural gas vehicles and stationary combustion systems. This paper is a qualitative assessment of the gas industry proposal and recommends a natural gas R&D strategy for the DOE. The methodology is a conceptual framework based on an analysis of market failures and the energy policy objectives of the DOE`s (1991) National Energy Strategy. This framework would assist the DOE in constructing an R&D portfolio that achieves energy policy objectives. The natural gas supply program is recommended to the extent that it contributes to energy price stability. Stationary combustion programs are supported on ...

Energy Technology Data Exchange (ETDEWEB)

Results are presented from analyzing indicators for efficient operation of the fleet of production equipment under conditions of the ''Tsentral'naya'' mine of the production association ''Krasnoarmeyskugol'.'' Measures are presented which make it possible to increase the operating efficiency with minimum adjusted outlays.

Energy Technology Data Exchange (ETDEWEB)

Modern combined cycle power plants with natural gas as the only fuel reach efficiencies of up to 58% for electric power generation. Nevertheless the reserves of natural gas are more limited compared to the reserves of coal. Therefore possibilities should be investigated to use coal for such plants also. One concept, that combines the use of coal in a combined cycle application with high efficiencies is examined in this paper. According to this concept the exhaust gas of the gas turbine (vitiated air) is the combustion air for the pulverised coal combustion, that takes place in the bottoming steam generator. Due to the low oxygen content of the vitiated air the burnout of the coal may be incomplete. In order to avoid the incomplete combustion of the coal and the resulting decrease of the efficiency of the plant and possible emission problems, ...

Energy Technology Data Exchange (ETDEWEB)

In this paper we have proposed a novel gas turbine cycle with hydrogen-fueled chemical-looping combustion, and the system study on two hydrogen-fueled power plants, the new gas turbine cycle and an advanced gas turbine cycle with H{sub 2}/O{sub 2} combustion, has been investigated with the aid of exergy principle (EUD methodology). The hydrogen fueled chemical-looping combustion in the new gas turbine cycle consists of two successive reactions: hydrogen fuel is reacted with metal oxide (reduction of metal oxide), and then instead of air or pure oxygen, the reduced metal is successively oxidized by the saturated air. As a result, the new hydrogen-fueled gas turbine cycle has a breakthrough performance, with at least about 12 percentage-point higher efficiency compared to the gas turbine cycle with H{sub 2}/O{sub 2} combustion, and will be ...

Energy Technology Data Exchange (ETDEWEB)

Concepts involving combined gas-turbine/steam-turbine power-generation plants, in which the fuel gas for the gas turbine is produced via the gasification of coal, are now extremely advanced. This technology already permits efficiencies of around 50% current development targets view 65% as achievable. In conventional technology, efficiencies are tied to conditions, such as air and cooling-water temperatures, at the particular location. In combined-cycle power plants, the properties of the fuel coal also play an important part. There are, in face, coals which can be more advantageously used in a combined-cycle power plant than in a conventional one. These differences, combined with advantageous concepts for coal-fired combined-cycle power-generating plants, are presented and analyzed. Particular attention is devoted to individual losses occurring at coal conversion, thermodynamic ...

Energy Technology Data Exchange (ETDEWEB)

Disclosed is a gas-fired cooktop for a range which provides high thermal efficiency and low emissions of air pollutants, particularly low levels of NO{sub x}. The cooktop includes a perforated tile burner which radiates infrared energy upward at a high flux rate to rapidly quench burner gas temperatures and inhibit the formation of NO{sub x}. A perforated glass-ceramic jet plate positioned between the burner and a cooking vessel transmits most of the radiant infrared energy from the burner to the vessel and also forms jets of combustion products which are directed against the bottom of the vessel fo convective heating. Thermal efficiencies of up to about 70% and NO{sub x} emissions as low as about 15ppM are achieved by the cooktop.

Science.gov (United States)

The Gas Research Institute established the Gas Appliance Technology Center (GATC) in 1982 to develop improved gas appliances. Between 1986 and 1992, the scope of GATC activities at Battelle included technology transfer and overall industry support, residential appliances, commercial appliances, and residential space conditioning. The following tasks are representative of the GATC activities described in the report; gas burner technology, appliance venting, emissions, water heating, range/oven technology, self-powered appliances, commercial cooktop burners, reconstituting ovens, appliance reliability improvement, combination space-heating/water-heating systems, condensing heat exchangers, corrosion testing, and space heating technology. The report includes references to available sources for further reading.

Energy Technology Data Exchange (ETDEWEB)

The energy recovery by anaerobic purification of wastewaters from olive oil manufactured is reported. The process efficiency is 82%, and the gas (CH4-CO2) yield is 850 L/kg eliminated BOD.

UK PubMed Central (United Kingdom)

To maximize energy efficiency, gas turbine engines used in airplanes and for power generation operate at very high temperatures, even above the melting point of the metal alloys from which they are...Full Text Available

Energy Technology Data Exchange (ETDEWEB)

This paper proves that it is practicable to build a new power model which can work efficiently at night by using a type of fluorescence material. The utilization efficiency of photovoltaic cell is improved by prolonging the actual working hours of the cell within 24 hours. Both theoretical analysis and experiment on this model are carried out, and base on which the current-time curve (I-t curve) is depicted. It shows that the model which applies the fluorescence material to photovoltaic system is available. According to the analysis and comparison between the attenuating curve of the material and I-t curve of the power system, we can conclude that the weak illumination and the mismatch on wavelength are primary reasons for the low current. Finally, several improved measures of this power model for practical application are given, and it is expected to provide a new thought for photovoltaic study. ...

Energy Technology Data Exchange (ETDEWEB)

Apparatus and method for selective measurement of tritium oxide in an environment which may include other radioactive components and gamma radiation, the measurement including the selective separation of tritium oxide from a sample gas through a membrane into a counting gas, the generation of electrical pulses individually representative by rise times of tritium oxide and other radioactivity in the counting gas, separation of the pulses by rise times, and counting of those pulses representative of tritium oxide. The invention further includes the separate measurement of any tritium in the sample gas by oxidizing the tritium to tritium oxide and carrying out a second separation and analysis procedure as described above.

Energy Technology Data Exchange (ETDEWEB)

The performance of a high temperature ion source coupled to a helium gas-jet transport system for an efficient mass separation of neutron-rich alkaline earth and lanthanide isotopes is reported and the results of overall efficiency measurements using different cluster materials in the gas-jet are given. A fast, microprocessor controlled tape transport system for ..gamma..-spectroscopic studies on short-lived isotopes is described. Some results on the decay of 3.8sub(-s) /sup 152/Pr are presented.

Science.gov (United States)

The objective of the program was to develop a domestic cooktop with low-NOx emissions and high efficiency. During the first two phases of the program, three design concepts were developed, and two versions of developmental prototypes using the IR-Jet approach were fabricated and tested. The third phase was initiated to address the design issues of a simmer setting, air/gas metering, and jet plate durability and to develop prototypes for interested manufacturers.

Energy Technology Data Exchange (ETDEWEB)

Continually rising energy prices in global markets highlights a serious concern about the need to improve energy efficiency and the efficiency in the energy sector in many countries. China, as one of the fastest growing countries in the world and the largest coal producer, has high coal consumption but a low recovery rate of coal utilization. Coal efficiency and the efficiency in coal industry have therefore attracted a great deal of attention from Chinese policy makers, coal companies and academics. This study attempts to compare the relative technical efficiency performance of listed coal mining companies in China and the US using CCR and BCC models in advanced data envelopment analysis (DEA) linear programming. The results show that the level of relative efficiency in Chinese coal mining enterprises, regardless of total technical ...

Energy Technology Data Exchange (ETDEWEB)

This report details the data, assumptions and methodology for end-use forecasting of appliance energy use in the US residential sector. Our analysis uses the modeling framework provided by the Appliance Model in the Residential End-Use Energy Planning System (REEPS), which was developed by the Electric Power Research Institute. In this modeling framework, appliances include essentially all residential end-uses other than space conditioning end-uses. We have defined a distinct appliance model for each end-use based on a common modeling framework provided in the REEPS software. This report details our development of the following appliance models: refrigerator, freezer, dryer, water heater, clothes washer, dishwasher, lighting, cooking and miscellaneous. Taken together, appliances account for approximately 70% of electricity consumption and 30% of natural gas consumption in the US residential sector. Appliances are thus important to those residential sector policies ...

Energy Technology Data Exchange (ETDEWEB)

Simulation and experimental results on the transport of microbes and nutrients in one-dimensional cores are presented, and the development of a three-dimensional, three-phase, multiple-component numerical model to describe the microbial transport and oil recovery in porous media is described. The change of rock's wettability and associated relative permeability values after microbial treatments were accounted for in the model for additional oil recovery. Porosity and permeability reductions due to cell clogging have been considered and the production of gas by microbial metabolism has been incorporated. Governing equations for microbial and nutrient transport are coupled with continuity and flow equations under conditions appropriate for a black oil reservoir. The computer simulator has been used to determine the effects of various transport parameters on microbial transport phenomena. The model can accurately describe the observed transport of microbes, ...

International Nuclear Information System (INIS)

The use of natural energy sources and their conversion to secondary forms of energy are a crucial base for the development of our society with its continuous change of requirements due to an increase in population and the broadening of the needs in our modern life. As a consequence the consumption of primary energy resources rose drastically worldwide during the last 5 decades in particular in the industrialized regions such as Europe. Parallel in time the increasing awareness of negative effects of fuel dependent pollution on the environment and the introduction of stringent emission control regulations about 3 decades ago initiated extensive development and retrofit activities resulting in the today applied high level state of the art. As an additional challenge the worldwide debate about the potential effects of the emission of the s.c green house gases on the global climate in particular carbon dioxide from the use of predominantly fossil fuels have initiated in the European Union ...

Energy Technology Data Exchange (ETDEWEB)

This paper describes a practical knowledge on gas engine performance and combustion characteristics which are required by experimental studies for two types of developed gas burning engines, i. e. a spark ignited gas engine and a dual fuel engine, and also introduces their practical use and application. As for dual fuel engine performance, a manifold air pressure of about 27% was decreased, a scavenging ratio of 23% reduced and an exhaust temperature at the turbine inlet on 14% was increased at the gas engine operation under the mean effective cylinder pressure of 1.22 MPa in comparison with the diesel operation. Furthemore, empirical data on the effect of excess air ration on the engine performance and combustion characteristics, a risk of knocking during changing over on the dual fuel engine operation, and the rated output in case of using alternate fuel gas were reported. Two ...

International Nuclear Information System (INIS)

Isotopically selective IR multiphoton dissociation of molecules (SF_6, CF_3I) in a pulsed gas-dynamic flow interacting with a solid surface was studied for the first time. A noticeable (severalfold) increase in the yield of products (compared to excitation of molecules in an unperturbed flow) without a substantial decrease in the selectivity of the process was observed. Possible reasons for the effect are discussed. (laser applications and other topics in quantum electronics)

Energy Technology Data Exchange (ETDEWEB)

The ElectroStatic Precipitator (ESP) removes dust and tar droplets very efficiently from biomass product gas. Dust was removed for more than 99%. The tar dewpoint was reduced from 130C to 21C, which is sufficient for the application of the product gas in a gas engine. Tar removal is not sensitive to the voltage or fluctuations in the gas residence time . The voltage was varied between 28 to 37 kV{sub arith} and the gas residence time between 4 and 11s. Fouling of the ESP collector plates was negligible, which was concluded from visual inspection after 200 hours of operation. A reduction in the residence time reduces the size of the ESP and has a significant impact on the investment costs of the ESP. Keywords: electrostatic filter, tar removal, circulating fluidised bed (CFB)

British Library Electronic Table of Contents (United Kingdom)

A laboratory-scale multi-layer system was developed for the adsorption of PCDD/Fs from gas streams at various operating conditions, including gas flow rate, operating temperature and water vapor content. Excellent PCDD/F removal efficiency (>99.99%) was achieved with the multi-layer design with bead-shaped activated carbons (BACs). The PCDD/F removal efficiency achieved with the first layer adsorption bed decreased as the gas flow rate was increased due to the decrease of the gas retention time. The PCDD/F concentrations measured at the outlet of the third layer adsorption bed were all lower than 0.1ng I-TEQNm-3. The PCDD/Fs desorbed from BAC were mainly lowly chlorinated congeners and the PCDD/F outlet concentrations increased as the operating temperature was increased. In addition, the r...

International Nuclear Information System (INIS)

Ozone formation by a pulse positive corona discharge generated in the gas phase between a planar high voltage electrode made from reticulated vitreous carbon and a water surface with an immersed ground stainless steel plate electrode was investigated under various operating conditions. The effects of gas flow rate (0.5-3 litre min"-"1), discharge gap spacing (2.5-10 mm), applied input power (2-45 W) and gas composition (oxygen containing argon or nitrogen) on ozone production were determined. Ozone concentration increased with increasing power input and with increasing discharge gap. The production of ozone was significantly affected by the presence of water vapour formed through vaporization of water at the gas-liquid interface by the action of the gas phase discharge. The highest energy efficiency for ozone production was obtained using high voltage pulses of ...

International Nuclear Information System (INIS)

Gas Distribution Companies have long paid great attention to improving the quality of gas supply service to the consumer. This has involved them in an on-going attempt to successfully define and establish a clear computer assisted replacement programme which, when drawn up on a reliability basis, may also prove cost effective. The reasons which drive any gas line replacement programme are mainly related to the necessity: to improve the gas network asset so as to face a striking expected growth in gas demand; to refurbish old distribution systems with the purpose not only to increase the reliability and continuity of gas supply but also to reduce the rate of maintenance costs due to frequent repair works; to prevent the possibility of massive replacement works for a progressing ageing of the network. This paper will ...

Energy Technology Data Exchange (ETDEWEB)

The University of Georgia, in collaboration with GE Global Research, has investigated the relevant quenching mechanism of phosphor coatings used in white light devices based on UV LEDs. The final goal of the project was the design and fabrication of a high-efficacy white light UV-LED device through improved geometry and optimized phosphor coatings. At the end of the research period, which was extended to seamlessly carry over the research to a follow-up program, we have demonstrated a two-fold improvement in the conversion efficiency of a white light LED device, where the increase efficacy is due to both improved phosphor quantum efficiency and lamp geometry. Working prototypes have been displayed at DOE sponsored meetings and during the final presentation at the DOE Headquarters in Washington, DC. During the first phase of the project, a fundamental understanding of quenching ...

UK PubMed Central (United Kingdom)

Magnetotactic bacteria contain chains of magnetically interacting crystals (magnetosome crystals), which they use for navigation (magnetotaxis). To improve magnetotaxis efficiency, the magnetosome crystals...Full Text Available

UK PubMed Central (United Kingdom)

BackgroundOnline technology is a promising resource for conducting clinical research. While the internet may improve a study's reach, as well as the efficiency of data collection,...Full Text Available

Science.gov (United States)

The goal of GRI's Gas Appliance Technology Center is to encourage the introduction of highly efficient, cost-effective, convenient gas appliances for residential and commercial gas users. The report covers activity at Battelle from February 1989 to April 1990 in broad support tasks, residential and commercial appliances, and residential space conditioning. Broad support tasks included the G/A/S Newsletter; the GATC InfoBase; and technology transfer, workshops, and GATC coordination. Residential appliance tasks included burner technology research, gas appliance venting, gas lighting, and plastics durability. Commercial appliance tasks included development of a commercial cooktop fuel/air mixing valve. Residential space conditioning tasks included a corrosion test method for gas appliances and vents, generic ...

Energy Technology Data Exchange (ETDEWEB)

The need to increase efficiency of volumetric receivers for use in solar power plants by reducing reradiation losses and increasing the ``volumetric effect`` has promoted the idea of a receiver with tapered ducts. These seems to be very promising since higher efficiency and considerable saving of material can be achieved, as compared to conventional receivers perforated with ducts of constant cross-section. A finite element program is being developed to calculate stationary heat transfer in the tapered ducts by free and forced convection in the gas flow, conduction in walls and in the gas, and solar and thermal radiation. Gas and wall temperatures are considered to be varying only in the flow direction. In order to perform the highly nonlinear calculations of radiative exchange, the exact knowledge of the view factors is necessary. The aim of the present work is to evaluate ...

International Nuclear Information System (INIS)

This paper presents part-load evaluation of a natural gas-fired chemical looping combustion (CLC) combined cycle with CO2 capture. The novel combined cycle employs an air-based gas turbine, a CO2-turbine and a steam turbine cycle. In this combined cycle, the CLC reactors replace combustion chamber of the gas turbine. The proposed combined cycle has a net plant efficiency of about 52.2% at full-load, including CO2 compression to 200 bar. The part-load evaluation shows that reducing the load down to 60% results in an efficiency drop of 2.6%-points. However, the plant shows better relative part-load efficiency compared to conventional combined cycles. The pressure in CLC-reduction and -oxidation reactors is balanced by airflow control, using a compressor equipped with variable guide vanes. A combination of control strategies is discussed for plant start-up and ...

Energy Technology Data Exchange (ETDEWEB)

This paper discusses design considerations for the recently introduced GaInP/GaAs monolithic tandem concentrator cell. The prototype device achieves a peak efficiency of 30.2% in a range of 140--180 suns, making this the first two-terminal device to demonstrate a verified efficiency exceeding 30%. At 425 suns the efficiency is still above 29%. The authors focus on the issues of grid design, top-cell thickness, and antireflectance coat. They also examine ways in which these aspects of the device may be modified to provide further performance improvements for future devices.

UK PubMed Central (United Kingdom)

BackgroundPerfluorocarbons (PFC) are used to improve gas exchange in diseased lungs. PFC have been shown to affect various cell types. Thus, effects on alveolar type II (ATII) cells...Full Text Available

Energy Technology Data Exchange (ETDEWEB)

This invention refers to the organic geochemistry and can be used in prospecting for oil and gas. The method includes taking samples of rocks, extracting from them the chloroform bitumoid and its thermal processing. In order to improve the accuracy, the equal quantities of bitumoid taken are exposed to gradual thermal treatment to temperatures exceeding the thresholds of thermal stability of sulfur-containing compounds, in each temperature interval, the content of hydrogen sulfide released in this case is revealed, and by its drastic increase at temperatures corresponding to the temperatures of the productive part of the section, a conclusion is drawn about the epigenetic nature of the bitumoid. The method makes it possible to improve the resolution of the bituminological prospecting for oil and gas.

Energy Technology Data Exchange (ETDEWEB)

In this paper, the authors investigate the technical and economical aspects of the natural gas injection in non-integrated pig-iron plants using charcoal in the blast furnace. The effects of the natural gas injection concerning the blast furnace flame temperature, charcoal consumption, productively and permeability are analyzed. It was found that the injection is beneficial in many ways, such as in the improvement of the productivity and quality, if the flame temperature is kept within an appropriate range. In the financial-economic project`s evaluation, the cash flow for the natural gas injection was analysed considering two blast conditions: through the drying and oxygen enrichment of the air. A sensibility analysis is presented in which the internal rate of return of the investment varies according to the prices of charcoal and oxygen. 3 refs., 3 figs., 3 tabs

International Nuclear Information System (INIS)

AISI 5140 steel was plasma nitrided at various gas mixtures of nitrogen, hydrogen, and argon to investigate the actions of hydrogen and argon on plasma nitriding. The structural and mechanical properties of ion-nitrided AISI 5140 steel have been assessed by evaluating composition of phases, surface hardness, compound layer thickness, and case depth by using X-ray diffraction (XRD), microhardness tests, and scanning electron microscopy (SEM). It was found that the growth of compound layer can be controlled and the diffusion improved when the gas mixture includes H_2 gas. Additionally, it was determined that the amount of Ar in dual gas mixture must be at 20% minimum to obtain distinctive surface hardness and compound layer thickness.

Energy Technology Data Exchange (ETDEWEB)

NO[sub x] emission legislation requirements for large-bore internal combustion engines have required engine manufacturers to continue to develop and improve techniques for exhaust emission reduction. This paper describes the development of the Cooper-Bessemer Clean Burn gas-diesel (dual-fuel) engine that results in NO[sub x] reductions of up to 92 percent as compared with an uncontrolled gas-diesel engine. Historically, the gas-diesel and diesel engine combustion systems have not responded to similar techniques of NO[sub x] reduction that have been successful on straight spark-ignited natural gas burning engines. NO[sub x] levels of a nominal 1.0 g/BHP-h, equal to the spark-ignited natural gas fueled engine, have been achieved for the gas-diesel and are described. In addition, the higher opacity exhaust plume characteristic of ...

Science.gov (United States)

The purpose of this project is to demonstrate targeted infill and extension drilling opportunities, better determinations of oil-in-place, methods for improved completion efficiency and the suitability of waterflooding in certain shallow-shelf carbonate reservoirs in the Williston Basin, Montana, North Dakota and South Dakota. Results of seismic surveys are presented.

Energy Technology Data Exchange (ETDEWEB)

A methane catalytic decomposition reactor-direct carbon fuel cell-internal reforming solid oxide fuel cell (MCDR-DCFC-IRSOFC) energy system is highly efficient for converting the chemical energy of methane into electrical energy. A gas turbine cycle is also used to output more power from the thermal energy generated in the IRSOFC. In part I of this work, models of the fuel cells and the system are proposed and validated. In this part, exergy conservation analysis is carried out based on the developed electrochemical and thermodynamic models. The ratio of the exergy destruction of each unit is examined. The results show that the electrical exergy efficiency of 68.24% is achieved with the system. The possibility of further recovery of the waste heat is discussed and the combined power-heat exergy efficiency is over 80%. (author)

International Nuclear Information System (INIS)

A life cycle assessment was performed to quantify the non-renewable (fossil) energy use and global warming potential (GWP) in electricity generation from a typical gas fired combined cycle power plant in Singapore. The cost of electricity generation was estimated using a life cycle cost analysis (LCCA) tool. The life cycle assessment (LCA) of a 367.5 MW gas fired combined cycle power plant operating in Singapore revealed that hidden processes consume about 8% additional energy in addition to the fuel embedded energy, and the hidden GWP is about 18%. The natural gas consumed during the operational phase accounted for 82% of the life cycle cost of electricity generation. An empirical relation between plant efficiency and life cycle energy use and GWP in addition to a scenario for electricity cost with varying gas prices and plant efficiency have been established.

Science.gov (United States)

The U.S. Department of Energy and EPRI have co-funded this project to improve the control of mercury emissions from coal-fired power plants equipped with wet flue gas desulfurization (FGD) systems. The project investigated catalytic oxidation of vapor-pha...

Energy Technology Data Exchange (ETDEWEB)

A gas injection diesel engine was developed as an approaching measure to the diversification of fuel. Contrary to the usual low pressure gas application engine, this engine applies a so-called diffuse combustion method, in which high pressure (24.7Mpa) gas fuel is injected directly in the cylinder and is ignited and combusted by a little pilot fuel injected almost at the same time. The engine have following features. As a principle, it can attain the same heat efficiency and output rate as a diesel engine in any load range. It is excellent in responsibility to load fluctuation. There is no internal leakage of gas fuel to the scavenging chamber (the crank chamber) in the compression stroke. Not only a wide range of mixed combustion of gas fuel and heavy oil fuel, but also single combustion of heavy oil is possible. It is, therefore, drawing attention as an engine ...

International Nuclear Information System (INIS)

By comparison of standard entropies theoretically calculated and determined from gas-chromatographic data for 40 halo-aliphatic and halo-aromatic compounds 8 organic iodine compounds among them, adsorbed on graphitized thermal carbon black it was found that in all the cases the molecular model of ideal two-dimensional gas is a sufficiently good approximation. It was shown that for a number of systems the agreement can be improved if the vibrations of the center of molecular mass relative to the surface are taken into account

Energy Technology Data Exchange (ETDEWEB)

Improving software for the analysis of fenestration product energy efficiency and developing related information technology products that aid in optimizing the use of fenestration products for energy efficiency are essential steps toward ensuring that more efficient products are developed and that existing and emerging products are utilized in the applications where they will produce the greatest energy savings. Given the diversity of building types and designs and the climates in the U.S., no one fenestration product or set of properties is optimal for all applications. Future tools and procedures to analyze fenestration product energy efficiency will need to both accurately analyze fenestration product performance under a specific set of conditions and to look at whole fenestration product energy performance over the course of a yearly cycle and in the context of whole buildings. ...

Energy Technology Data Exchange (ETDEWEB)

Testbed trials of the Sulzer RTA84 dual-fuel engine were successfully completed at the IHI Aioi engine works (Japan) in April 1986. This newly-developed engine, output range 15 to 40 MW, can be operated with both diesel or heavy oil and methane gas at comparable thermal efficiency and unchanged output. The RTA dual-fuel engine was developed in close collaboration between Sulzer Brothers Limited, Switzerland and its Japanese licensees Ishikawajima-Harima Heavy Industries Co. Ltd. (IHI), Nippon Kokan KK (NKK) and Sumitomo Heavy Industries Ltd. (SHI). Intended for the propulsion of LNG carriers, where the boil-off gas from the ship's cargo is exploited or for the generation of electricity in stationary plants, the RTA dual-fuel engine is an economic and reliable alternative to the steam or gas turbines.

British Library Electronic Table of Contents (United Kingdom)

A large portion of world?s natural gas reserves are ?stranded?? resources, the drive to monetize these resources leads to the development of gas-to-liquids (GTL) and liquefied natural gas (LNG) technologies. LNG has the advantage of having been developed for the past 40 years and having an excellent safety record. GTL on the other hand is another option with substantial benefits, but its development stage and commercial viability are far behind LNG. This paper presents a techno-economic comparison of GTL with LNG, including technical development, plant efficiency, market potential for the products, and capital cost for the infrastructure. The aim is to give an overall view on both LNG and GTL and provide a perspective on the profitability of these two technologies.

International Nuclear Information System (INIS)

Brief summaries are given of research carried out in the following areas: absorption spectroscopy of titanium, niobium, and molybdenum in uranium alloys; atomic absorption spectroscopy of selenium in stainless steel, computer program improvements for spectrophotometer control, and detection of beryllium in stack gases; electrolysis for inactivation of bacteria in cooling-tower water; improved solvent analysis by gas chromatography; sequential radionuclide separation for various sample matrices; progress on an electron microprobe analyzer; and miscellaneous projects.

Energy Technology Data Exchange (ETDEWEB)

The objective of this work was to identify methods of improving the performance of gas-fired radiant burners through the use of Continuous Fiber Ceramic Composites (CFCCs). Methods have been identified to improve the price and performance characteristics of the porous surface burner. Results are described.

Energy Technology Data Exchange (ETDEWEB)

Efficiency of energy coversion of primary energy to an end use in industrial countries is about 30%. This is insufficient. Evaluating on basis of exergy efficiency becomes only about 15%. Usage of fuel cells give a great chance to improve efficiency. This concerns in particular to high temperature fuel cell systems SOFC and MCFC as well as their combination with heat pumps. [German] Die Effizienz der Energieversorgung in Industrielaendern ist energetisch bewertet mit rund 30 % unbefriedigend. Legt man den strengeren, energiewirtschaftlich treffenderen exergetischen Massstab an, halbiert sich dieser Wert sogar. Brennstoffzellen bieten durch ihren Einsatz Moeglichkeiten zur Effizienzerhoehung. Dies gilt insbesondere fuer die Hochtemperatursysteme SOFC und MCFC sowie deren Verbund mit Waermepumpen.

International Nuclear Information System (INIS)

There are several concerns which bring to consider natural gas as a viable alternative to liquid fuels in transport. First, natural gas allows the curbing of global pollution in this steadily growing industry. Indeed, decoupling greenhouse gas emissions from transport growth has become a major issue in tackling climate change. Second, a more extensive use of natural gas would relieve city air quality, which is presently at levels harmful of human health. Nonetheless, this is just one side of the coin. The other side entails building a refuelling station network, and this carries financial requirements. The financing fraction holds a pivotal role in deciding whether natural gas for automotive purposes is an efficient solution. The final aim of this work is, therefore, to compare the natural gas advantages, stemming from avoided global and ...

Energy Technology Data Exchange (ETDEWEB)

The fuel economy of different types of trucks was simulated. Preliminary vehicle simulation activity took place in order to determine a feasible range of vehicle fuel efficiency improvements that could be obtained. Another objective was to provide a start to the Systems Analysis road mapping process in order to identify significant improvements for future studies at minimal costs. Technology improvements to all types of trucks were categorized in relation to engine improvements, the incorporation of continuously variable transmissions, hybrid drivetrain technology and improvements in aerodynamic drag, rolling resistance and weight reduction. The trucks which had the largest national impact were identified from data on vehicles, miles driven, fuel consumption and exhaust gases. The study involved Class 2B utility trucks, Class 6 enclosed delivery trucks, Class 8 ...

Energy Technology Data Exchange (ETDEWEB)

The Greater Green River Basin (GGRB) of Wyoming has produced abundant oil and gas out of multiple reservoirs for over 60 years, and large quantities of gas remain untapped in tight gas sandstone reservoirs. Even though GGRB production has been established in formations from the Paleozoic to the Tertiary, recent activity has focused on several Cretaceous reservoirs. Two of these formations, the Ahnond and the Frontier Formations, have been classified as tight sands and are prolific producers in the GGRB. The formations typically naturally fractured and have been exploited using conventional well technology. In most cases, hydraulic fracture treatments must be performed when completing these wells to to increase gas production rates to economic levels. The objectives of the GGRB production improvement project were to apply the concept of horizontal and directional drilling to the ...

International Nuclear Information System (INIS)

A single plasma process involving three consecutive steps has been developed for producing high gas flow catalytic nanostructures on the electrodes of proton exchange membrane (PEM) fuel cells (FC). Using a high density helicon radio frequency (13.56 MHz) plasma, nickel is sputtered onto a porous carbon support. Changing the background gas from argon to methane/hydrogen allowed 2 ?m long, 37 nm diameter carbon nanofibres (CNFs) to be grown by diffusion through the nickel clusters in a 'tip growth' mechanism at the relatively low temperature of 400 deg. C. The third step involves plasma sputtering of platinum onto the CNFs, resulting in nanoclusters (3-8 nm) being formed on the periphery of the CNFs. Four FC cathodes were synthesized on carbon paper and PTFE/carbon loaded cloth (known as gas diffusion layer, GDL), both with and without CNFs, with the Pt/CNFs nanostructures grown on PTFE/carbon loaded cloth having the best FC ...

Science.gov (United States)

Two branches of research are conducted in this thesis. The first deals with nonlinear combustion response as a mechanism for triggering combustion instabilities in solid rocket motors. A nonlinear wave equation is developed to study a wide class of combustion response functions to second-order in fluctuation amplitude. Conditions for triggering are derived from analysis of limit cycles, and regions of triggering are found in parametric space. Introduction of linear cross-coupling and quadratic self-coupling among the acoustic modes appears to be how the nonlinear combustion response produces triggering to a stable limit cycle. Regions of initial conditions corresponding to stable pulses were found, suggesting that stability depends on initial phase angle and harmonic content, as well as the composite amplitude, of the pulse. Also, dependence of nonlinear stability upon system parameters is considered. The second part of this thesis presents research for a controller to ...

International Nuclear Information System (INIS)

Nonevaporable getters (NEGs) have been extensively studied in the last several years for their sorption properties toward many gases. In particular, an innovative alloy as a thin film by magnetron sputtering was developed and characterized at the European Organization for Nuclear Research. It is composed of Ti-Zr-V and protected by an overlayer of palladium (Pd), according to a technology for which the authors got the licence. NEG-Pd thin films used in combination with ion getter pumps is a simple, easy way to handle pumping devices for ultrahigh and extremely high vacuum applications. To show how to apply this coating technology to the internal surface of different types of ion pumps, the authors carried out several tests on pumps of various shapes, sizes (in terms of nominal pumping speed), and types (diode, noble diode, and triode). Special care was taken during the thermal cycle of baking and activation of the pumps to preserve the internal film from sources of contamination and/or ...

Energy Technology Data Exchange (ETDEWEB)

The concept of a direct energy recovery system that applies a varying magnetic field is proposed for a negative-ion-based neutral beam injection system (NNB) to heat a plasma and/or drive a plasma current in a fusion reactor. The output beam energy and power of such an NNB will be {approximately}1 MeV and {approximately}1- MW/beam-line, respectively, and nearly the same amounts of positive- and negative-ion beams remain unneutralized in an NNB by using a gas-neutralizing cell. Therefore, the output of a beam direct convertor in an NNB is a bipolar direct current (dc) electric power with close to {plus_minus} 1 MV and several amperes if a conventional electrostatic or magnetostatic field is applied for ion beam separation. However, such high-voltage dc power is difficult to handle at the point of the regeneration of the power back to a commercial electric line because a very high voltage inverter tough enough to withstand occasional sparkdowns at recovery electrodes ...

Energy Technology Data Exchange (ETDEWEB)

Uranium enrichment by gas centrifugation relies on the pressure diffusion of the isotopes when their gaseous mixture is submitted to the pressure diffusion in the strong radial pressure gradient due to the centrifugal force in a very rapidly rotating cylinder. To compute the isotope separation in a gas centrifuge, the viscous compressible Navier-Stokes equations are solved for the mixture, then the diffusion equations are solved for the isotopes. As far as the separation performance is concerned, the models deal with the steady state of the axi-symmetric gas motion in the rotating cylinder. The numerical tools are briefly presented: first, the MOLINA code which numerically solves the axi-symmetric gas motion in the specific conditions of rapid rotation by use of a change of variables suited to the high density gradient and by use of a Marker And Cell method; then, the diffusion equations solver which ...

Energy Technology Data Exchange (ETDEWEB)

During the last 15 years cycles with CO{sub 2} capture have been in focus, due to the growing concern over our climate. Often, a natural gas fired combined cycle with a chemical absorption plant for CO{sub 2} capture from the flue gases have been used as a reference in comparisons between cycles. Neither the integration of the steam production for regeneration of amines in the combined cycle nor the off-design behaviour of such a plant has been extensively studied before. In this paper, the integration of steam production for regeneration of the amines is modelled at design load and studied in off-design conditions for a combined cycle. Different ambient conditions and part-load strategies and their influence on the cycle performance are also examined. Of particular interest is a novel strategy with the possibility of longer life of gas turbine blading, with marginal loss in efficiency. The off-design performance of the ...

Energy Technology Data Exchange (ETDEWEB)

The present paper deals with the conversion of solar energy in a gas turbine plant with a parabolic dish collector. Particular consideration is devoted to the thermodynamic and mechanical design and partload behavior of the receiver. The incident sunlight is focussed by the parabolic dish and then beamed into the cavity receiver. Here the working medium of the gas turbine flows through tubes and is heated up to the receiver outlet temperature. The task of the receiver is to transfer the radiated energy as efficiently as possible to the working medium. Furthermore the required heating surface should be small as possible i.e. optimum use must be made of the tube material with respect to its state of stress. It is shown which geometric and thermodynamic plant parameters influence these two design criteria. An optimum receiver design is presented on the basis of the results thus obtained. Finally, the variations in receiver ...

Energy Technology Data Exchange (ETDEWEB)

The procedure followed by the Laboratorio de Metrologia Nuclear in Sao Paulo, Brazil, for the standardization of {sup 242g} Am is described. The calibration system was composed of a 4 {pi} gas-flow proportional counter coupled to a pair of NaI(Tl) crystals operating in coincidence. The samples were produced by irradiating dried aliquots of {sup 241} Am with thermal and epithermal neutrons at the IEA-R1 research reactor. The efficiency tracer technique has been applied using {sup 60} Co as tracer. The beta detection efficiency was changed by external absorbers and extrapolated to unity by linear least square fitting applying covariance methodology. (author)

Energy Technology Data Exchange (ETDEWEB)

Southern California Gas Co.`s (SoCalGas) Energy Resource Center (ERC) in Downey, Calif. is a 45,000 ft{sup 2} (4,181 m{sup 21}) conference and education center created to help energy decision-makers find the most energy-efficient, cost-effective and environment-sensitive solutions to their energy requirements. The center has 36,000 ft{sup 2} (3,344 m{sup 2}) of remodeled space and 9,000 ft{sup 2} (836 m{sup 2}) of new space, all designed to showcase the latest energy-efficient and environment-sensitive technologies. The building is one of the 25 buildings in the US to be designated as Energy Star Showcase buildings by the US Environmental Protection Agency.

Energy Technology Data Exchange (ETDEWEB)

NO{sub x} compounds, specifically NO and NO{sub 2}, are pollutants and potent greenhouse gases. Compact and inexpensive NO{sub x} sensors are necessary in the next generation of diesel (CIDI) automobiles to meet government emission requirements and enable the more rapid introduction of more efficient, higher fuel economy CIDI vehicles. Because the need for a NO{sub x} sensor is recent and the performance requirements are extremely challenging, most are still in the development phase. Currently, there is only one type of NO{sub x} sensor that is sold commercially, and it seems unlikely to meet more stringent future emission requirements. Automotive exhaust sensor development has focused on solid-state electrochemical technology, which has proven to be robust for in-situ operation in harsh, high-temperature environments (e.g., the oxygen stoichiometric sensor). Solid-state sensors typically rely on yttria-stabilized zirconia (YSZ) as the oxygen-ion conducting ...

Energy Technology Data Exchange (ETDEWEB)

The Externally-Fired Combined Cycle (EFCC) offers a method for operating high-efficiency gas and steam turbine combined cycles on coal. In the EFCC, an air heater replaces the gas turbine combustor so that the turbine can be indirectly fired. Ceramic materials are required for the heat exchange surfaces to accommodate the operating temperatures of modern gas turbines. The ceramic air heater or heat exchanger is the focus of this program, and the two primary objectives are (1) to demonstrate that a ceramic air heater can be reliably pressurized to a level of 225 psia (1.5 MPa); and (2) to show that the air heater can withstand exposure to the products of coal combustion at elevated temperatures. By replacing the gas turbine combustor with a ceramic air heater, the cycle can use coal or other ash-bearing fuels. Numerous programs have attempted to fuel high ...

Energy Technology Data Exchange (ETDEWEB)

It has been understood that production of hydrogen from fossil and carbonaceous fuels with reduced CO{sub 2} emission to the atmosphere is key to the production of hydrogen-rich fuels for mitigating the CO{sub 2} greenhouse gas climate change problem. The conventional methods of hydrogen production from fossil fuels (coal, oil, gas and biomass) include steam reforming and water gas shift mainly of natural gas (SRM). In order to suppress CO{sub 2} emission from the steam reforming process, CO{sub 2} must be concentrated and sequestered either in or under the ocean or underground (in aquifers, or depleted oil or gas wells). Up to about 40% of the energy is lost in this process. An alternative process is the pyrolysis or the thermal decomposition of methane, natural gas (TDM) to hydrogen and carbon. The carbon can either be sequestered or sold on the market as a ...

International Nuclear Information System (INIS)

A study is made into microhardness and structure of coatings on various system steels (37G2S, 25Kh5M, R6M5), obtained by ion nitriding in a low pressure (10"-"1 Pa) arc discharge plasma. A comparison of properties is accomplished for steels nitrided in an arc gas discharge and in a furnace. It is stated that ion-plasma nitriding in an arc gas plasma generator is an efficient method of alloy steels hardening which allows changing the structure and increasing the hardness of a surface layer up to rather great depth

Energy Technology Data Exchange (ETDEWEB)

New technological advances make it possible to perform on site gas-in-oil analysis quickly and efficiently. Gas-in-oil analysis is crucial in assessing the status of oil-filled electrical equipment. The new technique is used for extracting and measuring gases dissolved in electrical insulating oil. On-site sampling requires the use of a specially designed 100 ml capacity syringe. Extraction of the dissolved gases is made with a precise ratio of oil to air. A comparison was made between the analysis of the on-site and the laboratory techniques. Results showed that the detection limits of the on-site technique were comparable to those obtained by laboratory methods.

Energy Technology Data Exchange (ETDEWEB)

Solar energy can be economically converted into electrical energy for small and medium power outputs. A typical solar power plant consists of a parabolic dish, cavity receiver and gas turbine. To obtain high gas turbine efficiencies, the working fluid used has to be heated to high temperatures. This necessitates the use of expensive high-quality materials for the tubes in the receiver. This expense must be kept to a minimum. The present paper demonstrates how this aim can be achieved by meeting the so-called Bammert Criterion.

Energy Technology Data Exchange (ETDEWEB)

A large scintillation chamber of 6.7 l volume for direct radon concentration measurements in gas is presented. With two 5 in. photomultipliers on opposite sides, working in coincidence, a concentration as low as about 0.5 mBq/l is detectable with 10% standard deviation after 1000 min measuring time. With the achieved background count rate of 0.42 counts/min and the counting efficiency of 0.607 for [sup 222]Rn and its progenies the absolute minimal detectable specific activity is reached with 0.17 mBq/l at about 12 000 min. The method to determine this minimum detectable activity is outlined. ((orig.))

Energy Technology Data Exchange (ETDEWEB)

An essential part of fire risk assessment is the analysis of fire hazards and fire propagation. In this work, models and tools for two different aspects of numerical fire simulation have been developed. The primary objectives have been firstly to investigate the possibility of exploiting state-of-the-art fire models within probabilistic fire risk assessments and secondly to develop a computationally efficient solver of thermal radiation for the Fire Dynamics Simulator (FDS) code. In the first part of the work, an engineering tool for probabilistic fire risk assessment has been developed. The tool can be used to perform Monte Carlo simulations of fires and is called the Probabilistic Fire Simulator (PFS). In Monte Carlo simulation, the simulations are repeated multiple times, covering the whole range of variability of the input parameters and thus resulting in a distribution of results covering what can be expected in reality. In practical applications, advanced ...

International Nuclear Information System (INIS)

The small pilot facility of a cyclone type suspension incineration system of radioactive waste was set up in order to evaluate the decontamination efficiency of a high efficiency ceramic filter. The evaluation was made by use of "5"4Mn, "5"9Fe, "6"0Co, "6"5Zn and "1"3"7Cs. 1. The decontamination factor by one line of ceramic filter for every species were over 10"5. 2. The decontamination factor increased by one oder when water vapor exists in off-gas. The same tendency was also observed when iron dioxide existed at the incineration of cation exchange resin. (author).

British Library Electronic Table of Contents (United Kingdom)

A methane catalytic decomposition reactor-direct carbon fuel cell-internal reforming solid oxide fuel cell (MCDR-DCFC-IRSOFC) energy system is highly efficient for converting the chemical energy of methane into electrical energy. A gas turbine cycle is also used to output more power from the thermal energy generated in the IRSOFC. In part I of this work, models of the fuel cells and the system are proposed and validated. In this part, exergy conservation analysis is carried out based on the developed electrochemical and thermodynamic models. The ratio of the exergy destruction of each unit is examined. The results show that the electrical exergy efficiency of 68.24% is achieved with the system. The possibility of further recovery of the waste heat is discussed and the combined power-heat e...

Energy Technology Data Exchange (ETDEWEB)

The purpose of this study is to develop the radioisotope tracer technology, which can be used in solving industrial and environmental problems and to build a strong tracer group to support the local industries. In relation to the tracer technology in 1999, experiments to estimate the efficiencies of a sludge digester of a waste water treatment plant and a submerged biological reactor of a dye industry were conducted. As a result, the tracer technology for optimization of facilities related to wastewater treatment has been developed and is believed to contribute to improve their operation efficiency. The quantification of the experimental result was attempted to improve the confidence of tracer technology by ECRIN program which basically uses the MCNP simulation principle. Using thin layer activation technique, wear of tappet shim was estimated. Thin layer surface of a tappet shim was irradiated by ...

Energy Technology Data Exchange (ETDEWEB)

A case study of a hypothetical offshore production fixed leg platform facility is presented. The purpose of the case study is to demonstrate the advantages offered by modern, fuel efficient large gas turbines in central power generation service for offshore production. The case study was presented using the Rolls- Royce RB211 large gas turbine with facility production of approximately 240,000 BPD of oil and 540 MMSCFD of associated gas. The gas was subjected to three stages of separation for removal of hydrocarbon liquids and water. The liquids, natural gas, and crude oil were exported from the production platform to an onshore receiving terminal. Gas compression is the service that requires the greatest amount of power for any given production facility. For this case study, gas compression represented approximately 70 ...

Energy Technology Data Exchange (ETDEWEB)

A natural gas and diesel dual-fuel turbocharged compression ignition (CI) engine is developed to reduce emissions of a heavy-duty diesel engine. The compressed natural gas (CNG) pressure regulator is specially designed to feed back the boost pressure to simplify the fuel metering system. The natural gas bypass improves the engine response to acceleration. The modes of diesel injection are set according to the engine operating conditions. The application of honeycomb mixers changes the flowrate shape of natural gas and reduces hydrocarbon (HC) emission under low-load and lowspeed conditions. The cylinder pressures of a CI engine fuelled with diesel and dual fuel are analysed. The introduction of natural gas makes the ignition delay change with engine load. Under the same operating conditions, the emissions of smoke and NO{sub x} from the dual-fuel engine are both ...

Energy Technology Data Exchange (ETDEWEB)

A geologic sequestration pilot in the Thornton gas field in Northern California, USA involves injection of up to 4000 tons of CO{sub 2} into a stacked gas and saline formation reservoir. Lawrence Berkeley National Laboratory (LBNL) is leading the pilot test in collaboration with Rosetta Resources, Inc. and Calpine Corporation under the auspices of the U.S. Department of Energy and California Energy Commission's WESTCARB, Regional Carbon Sequestration Partnership. The goals of the pilot include: (1) Demonstrate the feasibility of CO{sub 2} storage in saline formations representative of major geologic sinks in California; (2) Test the feasibility of Enhanced Gas Recovery associated with the early stages of a CO{sub 2} storage project in a depleting gas field; (3) Obtain site-specific information to improve capacity estimation, risk assessment, and performance prediction; (4) ...

International Nuclear Information System (INIS)

Monitoring and diagnostic systems are of main importance for a safe and efficient operation of nuclear power plants. The author describes new developments with respect to vibration monitoring with a functional extension in the time domain for den secondary circuit, the development of a local system for the surveillance of rotating machines, the structure-borne sound monitoring with improvement of event analysis, esp. the loose part locating, leakage monitoring with a complete system for humidity measurement, and the development of a common platform for all monitoring and diagnostic systems, that allows an efficient access for comparison and cross references.

International Nuclear Information System (INIS)

Pattern formation on GaAs by Ga"+ focused-ion-beam (FIB) irradiation and subsequent Cl_2 gas etching was carried out. A higher etch rate at the FIB-irradiated area compared with that not irradiated under Cl_2 gas allows pattern construction without a mask process. The degree of residual crystal damage was evaluated using photoluminescence (PL) intensity measurements. The PL intensity in the etched region was one order of magnitude stronger than that of FIB sputtering, and was several times stronger than that of Ga"+ FIB-assisted Cl_2 etching. Etch depths of the order of 100 nm, which is five times deeper than that obtained by FIB sputtering, were efficiently performed using moderate Ga"+-ion doses.

Energy Technology Data Exchange (ETDEWEB)

Several natural gas vehicles have been built as part of Ford's Alternative Fuel Demonstration Fleet. Two basic methods, compressed gas (CNG), and liquified gas (LNG) were used. Heat transfer danger and the expense and special training needed for LNG refueling are cited. CNG in a dual-fuel engine was demonstrated first. The overall results were unsatisfactory. A single fuel LNG vehicle was then demonstrated. Four other demonstrations, testing different tank weights and engine sizes, lead to the conclusion that single fuel vehicles optimized for CNG use provide better fuel efficiency than dual-fuel vehicles. Lack of public refueling stations confines use to fleet operations.

Energy Technology Data Exchange (ETDEWEB)

Conversion of biomass into producer gas by thermal gasification broadens the scope of biomass applications. Usually, tar has to be removed from the producer gas. Tar recycling within the gasification process may solve the associated waste problem and increase the system efficiency, provided tar is broken down under gasification conditions. We present results of tar recycling experiments at a Circulating Fluidised Bed gasifier. At 830{sup o}C, from each of 15 main tar compounds 70-80% are broken down. Continuous recycling of tar would increase the tar content in raw producer gas by 50% at most and save about 3% fuel input. 10 refs., 3 figs., 3 tabs.

Science.gov (United States)

As coal becomes more and more important as a power plant fuel in this time of energy shortage and the combustion of high-sulfur coals that would impair air quality, efforts have been made to devise efficient processes to control sulfur dioxide emission. Besides desulfurization before combustion, flue gas desulfurization is considered the most promising method that could also be applicable to all other fossil fuels. In this article, the flue gas desulfurization processes are briefly reviewed, and processes with highest use and with high potential for future use are compared from technical and economical points of view. In the selection of a desulfurization process, it is very important to consider the capacity of the plant, fuel type and fuel-to-sulfur ratio, availability and price of the reagent to be used, type, price, and market of side products, disposal problems of wastes, and environmental factors.

Energy Technology Data Exchange (ETDEWEB)

Diagnostic systems make it possible to recognize incipient faults in good time and help to increase the availability of power stations. The thermal efficiency and the effective terminal output are didicated by a number of influences. Deviations from the expected status can be identified via continuous recording of the operating parameters and calculation of derived data. An improved efficiency and economical load distribution lead to considerable cost savings. (orig.) [Deutsch] Die Verarbeitung von Messwerten und Signalen ermoeglicht eine umfassende Beurteilung des Anlagenzustandes und die Erkennung sich anbahnender Veraenderungen. Stoerungen, Schaeden oder eine unwirtschaftliche Betriebsweise koennen fruehzeitig erkannt werden. Erhoehte Verfuegbarkeit, geringerer Brennstoffverbrauch und optimierte Lastaufteilung bringen Kostenvorteile. (orig.)

Energy Technology Data Exchange (ETDEWEB)

Three new partially-aerated burners have been developed for Australian cooktops fired with natural gas, with maximum thermal inputs of 12, 7.5 and 5.5 MJ h{sup -1}. These novel burner designs minimise the NO{sub 2} emission per unit of useful energy, since NO{sub 2} is the more toxic nitrogen oxide of concern for indoor air pollution. They provide lower values of the ratio of NO{sub 2} emission to thermal efficiency than production burners, with respective reductions of 42, 13 and 23% compared with production burners of corresponding size. The traditional combustion diagrams of these prototype burners have been defined, on plots of primary aeration versus thermal input, to identify the regions of stable flame operation. However, the regions of satisfactory operation are further limited at low primary aeration by the Australian Gas Association requirement for CO/CO{sub 2} ratio <0.01 and at low thermal inputs by the ...

Energy Technology Data Exchange (ETDEWEB)

Operation safety and reliability are major guidelines in the design of city-gate units. Conventional natural gas heaters operate by a indirect mechanism, where liquid water is used to transfer heat by natural convection between the combustion chamber and the natural gas coil. In this work, the concept of vapor chamber is evaluated as an indirect gas heater. In a vapor chamber, liquid water is in contact with the heat source, and vaporizes. The vapor condenses in contact with the heat sink. A reduced scale model was built and tested in order to compare these two heating concepts where the combustion chamber was replaced by electrical cartridge heaters. This engineering model can operate either as a conventional heater or as a vapor chamber. The comparison between the concepts was done by inducing a controlled power to the cartridges and by measuring the resulting temperature distributions. In the novel design, the heat ...

Energy Technology Data Exchange (ETDEWEB)

This review examines the characteristics of the compression-ignition type of dual-fuel engine and the combustion phenomena that affect these characteristics. The specific areas covered involve normal combustion processes, the nature and origin of engine knock, operation with LNG, and the effect of intake temperature on combustion efficiency and exhaust composition.

Energy Technology Data Exchange (ETDEWEB)

The conductivity of the membrane is a limiting factor for the efficiency and power density of PEFCs. Because this conductivity is strongly dependent on the membrane hydration, water management is an important aspect of PEFC optimisation. Single cell model experiments were made in order to determine the in-plane hydration of a Nafion{sup R} membrane under fuel cell conditions as function of the gas humidities. (author) 4 fig., 3 refs.

Energy Technology Data Exchange (ETDEWEB)

The use of pressurised fluidized-bed coal combustion (fbc) in a combined cycle is seen as a most attractive technology for increasing the efficiency of electricity generation. The concept of pressurised fbc is described and the technical problems that are encountered in its operation and in limiting it to a gas turbine are discussed. Details are given of pilot plant facilities and current R and D programmes.

British Library Electronic Table of Contents (United Kingdom)

Purpose - Under the pressure of competition from non-state-owned enterprises (non-SOEs) since the Renovation in 1986, the Government of Vietnam has sought to reform state-owned enterprises (SOEs) in order to improve their productivity and efficiency. Whilst the theoretical efficiency benefits from the SOE reform have interested many, this study seeks to add empirical insights to this debate using Williamson's transaction cost economics (TCE). Design/methodology/approach - Organizational integration and transaction costs - two dimensions of firm efficiency - were compared between SOEs and non-SOEs using multivariate analyses of variance (MANOVA). The analysis was conducted in the context of the within-firm logistics processes of international multimodal transport (IMT) in Vietnam. Findings ...

Energy Technology Data Exchange (ETDEWEB)

A single cylinder diesel engine study of water-in-diesel emulsions was conducted to investigate the effect of water emulsification on the engine performance and gases exhaust temperature. Emulsified Diesel fuels of 0, 5, 10, 15 and 20 water/diesel ratios by volume were used in a single cylinder, direct injection diesel engine, operating at 1200-3300 rpm. The results indicate that the addition of water in the form of emulsion improves combustion efficiency. The engine torque, power and brake thermal efficiency increase as the water percentage in the emulsion increases. The average increase in the brake thermal efficiency for 20% water emulsion is approximately 3.5% over the use of diesel for the engine speed range studied. The proper brake specific fuel consumption and gases exhaust temperature decrease as the percentage of water in the emulsion increases. (author)

British Library Electronic Table of Contents (United Kingdom)

This article analyses the process of preparing the proposal for a new Finnish National Waste Plan (NWP 2007-2016). The focus of this study is on the use of the alternative concepts of waste prevention or material efficiency and on the shift in discourse from the former to the latter concept. The strengths and weaknesses of these competing concepts were analysed using criteria such as synergy, semantic aspects, legal context and applicability to monitoring. The discourse presented by different stakeholder groups was analysed. The implications of choosing either of the concepts were illustrated. The author concludes that waste prevention can be promoted just as well, or even better from the perspective of improving material efficiency. The concept must be complemented by policy instruments w...

Energy Technology Data Exchange (ETDEWEB)

This study estimates the electricity demand function for the residential sector of South Korea with the aim of examining the effects of improved energy efficiency, structural factors and household lifestyles on electricity consumption. In the study, time series data for the period from 1973 to 2007 is used in a structural time series model to estimate the long-term price and income elasticities and annual growth of underlying energy demand trend (UEDT) at the end of the estimation period. The result shows a long-term income elasticity of 1.33 and a long-term price elasticity of -0.27% with -0.93% as the percentage growth of UEDT at the end of the estimation period. This result suggests that, in order to encourage energy efficiency in the residential sector, the government should complement the market based pricing policies with non-market policies such as minimum energy efficiency standards and public ...

Energy Technology Data Exchange (ETDEWEB)

The paper is Part 2 of the study on the thermodynamic and thermoeconomic analyses of trigeneration system with a gas-diesel engine. In Part 1, thermodynamic and thermoeconomic methodologies for such a comprehensive analysis were provided, while this paper applies the developed methodology to an actual TRIGEN system with a rated output of 6.5 MW gas-diesel engine installed in the Eskisehir Industry Estate Zone, Turkey. Energy and exergy efficiencies, equivalent electrical efficiency, the Public Utility Regulatory Policies Act (PURPA) efficiency, fuel energy saving ratio, fuel exergy saving ratio and other thermodynamic performance parameters are determined for the TRIGEN system. The efficiencies of energy, exergy, PURPA and equivalent electrical efficiency of the entire system are found to be 58.97%, 36.13%, 45.7% and 48.53%, respectively. ...

Energy Technology Data Exchange (ETDEWEB)

When thorium was biosorbed by biomass of Rhizopus arrhizus or Aspergillus niger it could be removed by treatment using carbonate solutions, but not by phosphates or distilled water. Desorption was rapid, reaching completion in 15 and 30 min respectively. Desorption efficiency was independent of the desorbent concentration above 0.05 mol dm[sup -3] but was strongly dependent on the biomass concentration, decreasing as the biomass concentration increased for both species. Biomass from both species could be regenerated by desorption using sodium carbonate solutions and reused for biosorption. In both species, the efficiency of biosorption and desorption fell as the number of exposures increased although there was an initial rise in desorption efficiency for R. arrhizus. Biosorption and desorption efficiencies of A. niger biomass showed the steeper decline but both were severely reduced in R. arrhizus after ...

Energy Technology Data Exchange (ETDEWEB)

Gas distribution companies have long since paid great attention to improving the quality and safety of the gas supply service to the consumer. In particular the management of gas emergencies has always been a responsibility taken seriously by all sectors of the gas industry. Over the last few years, however, the concept and practices in risk management have been changing rapidly. This has involved gas companies in an on-going attempt to successfully define and establish clear computer assisted risk management practices. Risk management is the systematic use of management policy, procedures and means, with the aim to protect employees, the public, the environment and properties at an acceptable cost. This paper has the purpose of presenting: - the computer software of gas emergency management in use at Italgas S.p.A. for testing the ...

Energy Technology Data Exchange (ETDEWEB)

In order to promote the use of natural gas air-conditioning systems in the tertiary sector, Gaz de France (the French gas utility) in association with Electricite de France (EdF) and the French chamber of council engineers (CICF) have created the Acerclim organization which aims at certifying the quality of the design, realization and exploitation of air processing and air-conditioning installations according to the ISO 9001 criteria. This article describes this quality procedure named 'CHSB Air'. (J.S.)

Energy Technology Data Exchange (ETDEWEB)

Field corrosion tests were conducted on eight single tube materials and two welded overlay materials in three typical Japanese waste incineration plants in an effort to develop new corrosion-resistant superheater tubes capable of functioning efficiently under temperature and pressure conditions of 500 C and 100 kgf/cm{sup 2}-g in high-efficiency waste-to-energy (WTE) plants. Austenitic alloys containing higher concentrations of chromium, nickel, and molybdenum [Cr + Ni + Mo] showed excellent corrosion-resistant properties, and the new alloys JHN24 and HR30M showed good corrosion resistance. Different corrosion rates found in each of the three plants were explained by differences in operating conditions, such as gas temperature, concentration of molten salts resulting from chlorine (Cl) content of deposits, heavy metal (zinc oxide [ZnO] + lead oxide [PbO]) content, etc. It was confirmed that the corrosion rate of materials ...

Energy Technology Data Exchange (ETDEWEB)

Two-stage gasification allows power production from biomass and waste with high efficiency. The process involves pyrolysis at about 550C followed by heating of the pyrolysis gas to about 1300C in order to crack hydrocarbons and obtain syngas, a mixture of H2, CO, H2O and CO2. The second stage produces soot as unwanted by-product. Experimental results are reported on the suppression of soot formation in the second stage for two different fuels: beech wood pellets and Rofire pellets, made from rejects of paper recycling. Syngas obtained from these two fuels and from an industrial waste fuel has been cleaned and fed to a commercial SOFC stack for 250 hours in total. The SOFC stack showed comparable performance on real and synthetic syngas and no signs of accelerated degradation in performance over these tests. The experimental results have been used for the design and analysis of a future 25 MWth demonstration plant. As an alternative, a 2.6 MWth ...

Energy Technology Data Exchange (ETDEWEB)

An improved ion funnel design is disclosed that decreases the axial RF (parasite) fields at the ion funnel exit. This is achieved by addition of one or more compensation electrodes after the conductance limit electrode. Various RF voltage profiles may be applied to the various electrodes minimizing the parasite axial potential wells. The smallest RF aperture that serves as the conductance limiting electrode is further reduced over standard designs. Overall, the ion funnel improves transmission ranges of both low m/z and high m/z ions, reducing RF activation of ions and decreasing the gas load to subsequent differential pumping stages.

Energy Technology Data Exchange (ETDEWEB)

Government facilities and services are often the largest energy users and major purchasers of energy-using equipment within a country. In developing as well as industrial countries, government ''leadership by example'' can be a powerful force to shift the market toward energy efficiency, complementing other elements of a national energy efficiency strategy. Benefits from more efficient energy management in government facilities and operations include lower government energy bills, reduced greenhouse gas emissions, less demand on electric utility systems, and in many cases reduced dependence on imported oil. Even more significantly, the government sector's buying power and example to others can generate broader demand for energy-efficient products and services, creating entry markets for domestic suppliers and stimulating competition in ...

Energy Technology Data Exchange (ETDEWEB)

In Polymer Electrolyte Fuel Cell (PEFC) technology the reducing of volume and mass of the fuel cell stack and the improvement of catalyst utilization are of great interest. These parameters affect applicability and system cost. In this work we present an alternative way for reducing the stack volume by combining gas distribution and catalytic active area in one plate. Micro machined glassy carbon electrodes serve as support material for the platinum catalyst, as well as gas distributor at the same time. A comparison of these electrodes with conventional platinum-black gas diffusion electrodes under fuel cell conditions shows that the new system is a promising electrode type for enhanced power density and catalyst utilization. (author) 3 figs., 5 refs.

Energy Technology Data Exchange (ETDEWEB)

The 'KUPOLOPT' joint research project has as its target the economic and ecological optimization of cupola furnaces in foundries. The use of natural gas/oxygen burners during foundry operation is being studied on Fritz Winter Eisengiesserei GmbH and Co. KG's cupola furnace with the objective of enhancing melting rate, reducing emissions and permitting re-utilization of foundry and other particulates. This work is also intended to improve the cupola-furnace process in economic terms, in order to enhance its competitiveness. This article presents the results of the first project phase, which served to investigate the natural gas/oxygen burner as an external supplier of energy. (orig.)

British Library Electronic Table of Contents (United Kingdom)

As the main forestry species in the Canary Islands (Spain), Pinus canariensis is frequently used in afforestation programs. Several nursery techniques are commonly employed to modify its morphology and physiology with the aim of improving post-planting survival and growth. In this work, we studied how fertilization and light regime treatments applied during the nursery period modify biomass allocation patterns and produce effects in gas exchange and root hydraulic conductance. Seedlings were grown for a 6-month period in the nursery under two light regimes (full sunlight and 40% PAR reduction), and three fertilization levels were applied in each light regime. Morphology, biomass allocation patterns, leaf gas exchange and hydraulic conductance of the whole root system were evaluated. Fertil...

Energy Technology Data Exchange (ETDEWEB)

Preliminary studies were preformed to determine whether thermal conductivity of cementitious grouts used to backfill heat exchanger loops for geothermal heat pumps could be improved, thus improving efficiency. Grouts containing selected additives were compares with conventional bentonite and cement grouts. Significant enhancement of grout alumina grit, steel fibers, and silicon carbide increased the thermal conductivity when compared to unfilled, high solids bentonite grouts and conventional cement grouts. Furthermore, the developed grouts retained high thermal conductivity in the dry state, where as conventional bentonite and cement grouts tend to act as insulators if moisture is lost. The cementitious grouts studied can be mixed and placed using conventional grouting equipment.

Energy Technology Data Exchange (ETDEWEB)

Car weight corresponds directly to fuel consumption and driving performance. So in order to improve the fuel efficiency and performance of a car the weight has to be reduced. Magnesium as a light metal offers a wide range of weight saving opportunities, especially Magnesium wrought alloys with their improved mechanical properties have a high potential for structural applications. Mechanical properties in terms of their quality and anisotropy are dependent on the microstructure of the material and can be characterized by their degree of inhomogeneity, their grain size distribution and their crystallographic texture. Therefore the orientation distribution of grains, the grain size, its size distribution, the chemical composition (precipitates) itself influence the mechanical parameters and their anisotropy. In this presentation first results of mechanical anisotropy are given: differences in yield stress, r-values and their ...

International Nuclear Information System (INIS)

In Pakistan, the agricultural sector is the largest water user with 95%, leaving only marginal quantities for households and industry. On one hand, agriculture is a very important sector in Pakistan's economic development, contributing about 23 % to the national GDP -but industry contributes slightly more using only about 2 % of the available water resources. As Pakistan faces a growing problem of water shortage, significant achievements in water conservation have to be materialized, predominantly on the agricultural sector. There is scope for a higher degree of efficiency in water use, as water losses, namely in irrigation, are still rather high. There is another good reason for water conservation in agriculture: Over-irrigation results in rising water tables and increased soil salinity, which has reduced Pakistan's agricultural output during the last 2 decades by nearly 25%. Water conservation measures can be divided into (1) measures which are only applicable ...