Showing papers on "Power station published in 1997"

Gasification of biomass wastes and residues for electricity production.

Abstract: The technical feasibility and the economic and environmental performance of atmospheric gasification of biomass wastes and residues integrated with a combined cycle for electricity production are investigated for Dutch conditions. The system selected for study is an atmospheric circulating fluidized bed gasifier-combined cycle (ACFBCC) plant based on the General Electric LM 2500 gas turbine and atmospheric gasification technology, including flue gas drying and low-temperature gas cleaning (similar to the Termiska Processer AB process). The performance of the system is assessed for clean wood, verge grass, organic domestic waste, demolition wood and a wood-sludge mixture as fuel input. System calculations are performed with an ASPEN plus model. The composition of the fuel gas was derived by laboratory-scale fuel reactivity tests and subsequent model calculations. The net calculated efficiencies for electricity production are 35.4–40.3% (LHV) for the fuels studied, with potential for further improvement. Estimated investment costs, based on vendor quotes, for a fully commercial plant are 1500–2300 ECU per kW e installed. Electricity production costs, including logistics and in some cases negative fuel price, vary between minus 6.7 and 8.5 ECUct/kWh. Negative fuel costs are obtained if current costs for waste treatment can serve as income to the facility. Environmental performance is expected to meet strict standards for waste incineration in the Netherlands. The system seems flexible enough to process a wide variety of fuels. The kWh costs are very sensitive to the system efficiency but only slightly sensitive to transport distance; this is an argument in favour of large power-scale plants. As a waste treatment option the concept seems very promising. There seem to be no fundamental technical and economic barriers that can hamper implementation of this technology.

Life cycle assessment of a biomass gasification combined-cycle power system

Abstract: The potential environmental benefits from biomass power are numerous. However, biomass power may also have some negative effects on the environment. Although the environmental benefits and drawbacks of biomass power have been debated for some time, the total significance has not been assessed. This study serves to answer some of the questions most often raised in regard to biomass power: What are the net CO{sub 2} emissions? What is the energy balance of the integrated system? Which substances are emitted at the highest rates? What parts of the system are responsible for these emissions? To provide answers to these questions, a life cycle assessment (LCA) of a hypothetical biomass power plant located in the Midwest United States was performed. LCA is an analytical tool for quantifying the emissions, resource consumption, and energy use, collectively known as environmental stressors, that are associated with converting a raw material to a final product. Performed in conjunction with a t echnoeconomic feasibility study, the total economic and environmental benefits and drawbacks of a process can be quantified. This study complements a technoeconomic analysis of the same process, reported in Craig and Mann (1996) and updated here. The process studied is based on the conceptmore » of power Generation in a biomass integrated gasification combined cycle (BIGCC) plant. Broadly speaking, the overall system consists of biomass production, its transportation to the power plant, electricity generation, and any upstream processes required for system operation. The biomass is assumed to be supplied to the plant as wood chips from a biomass plantation, which would produce energy crops in a manner similar to the way food and fiber crops are produced today. Transportation of the biomass and other materials is by both rail and truck. The IGCC plant is sized at 113 MW, and integrates an indirectly-heated gasifier with an industrial gas turbine and steam cycle. 63 refs., 34 figs., 32 tabs.« less

Fuel cell power supply system

Abstract: A power supply system for enhancing the economic viability of different modes of transportation that incorporate fuel cells to generate electricity. For example, the power supply system of the present invention provides for the off-board use of the electric power generated by an on-board power plant, such as a fuel cell, of a mobile vehicle power system, such as an electric car. Off-board use, or use remote from the vehicle, of the electrical power includes the delivery of power to a remote site. Off-board stations are provided for delivery of fuel to the vehicle and/or for receiving the electrical power generated by the fuel cell. The off-board station and the vehicle are appropriately equipped for quick and easy interconnection such that electrical power is drawn from the fuel cell for off-board use.

Method of power generation and load management with hybrid mode of operation of a combustion turbine derivative power plant

Abstract: The invention provides a stand-alone, hybrid combustion turbine derivative power generation system sized for the most efficient and cost-effective base load operation that is also capable of providing, using air storage techniques, short-duration peak power, which is approximately 200% of the base load rating, and short-duration intermediate load power over a whole a range of loads between a base load and a peak load. The peak/intermediate power is also delivered with the best practical efficiency possible. The hybrid system may employ a variety of combustion turbine thermal cycles, including a simple cycle combustion turbine plant, combustion turbine plants with intercooling, reheat, recuperation, steam injection and humidification, and combined cycle power plants.

Renewable resource hydro/aero-power generation plant and method of generating hydro/aero-power

Abstract: A power plant and method for the generation of power from flowing air utilizes a generally vertically extending duct having an inlet open to atmosphere at an elevation above an outlet. A spray system is mounted adjacent the inlet for spraying droplets of a predetermined amount of water into the air causing the air and droplet mixture to become cooler and denser than the outside air to create a down draft of fluid within the duct. A power system mounted adjacent the outlet recovers energy from the downdraft of fluid passing through it. The predetermined amount of water sprayed is greater than the amount of water that would theoretically and potentially evaporate in the air throughout the entire elevation over an unlimited time period using fresh water droplets. The power plant can also be synergistically combined with desalination systems and aquaculture.

Exergy evaluation of two current advanced power plants : Supercritical steam turbine and combined cycle

Abstract: Two operating advanced power plants, a supercritical steam plant and a gas-stream turbine combined cycle, heve been analyzed using a methodology of graphical exergy analysis (EUDs). The comparison of two plants, which may provide the detailed information on internal phenomena, points out several inefficient segments in the combined cycle plant: higher exergy loss caused by mixing in the combustor, higher exergy waste from the heat recovery steam generator, and higher exergy loss by inefficiency in the power section, especially in the steam turbine. On the basis of these fundamental features of each plant, we recommend several schemes for improving the thermal efficiency of current advanced power plants.

Economic scales for first-generation biomass-gasifier/gas turbine combined cycles fueled from energy plantations

Abstract: This paper assesses the scales at which commercial, first-generation biomass integrated-gasifier/gas turbine combined cycle (BIG/GTCC) technology is likely to be most economic when fueled by plantation-derived biomass. First-generation BIG/GTCC systems are likely to be commercially offered by vendors beginning around 2000 and will be based on either pressurized or atmospheric-pressure gasification. Both plant configurations are considered here, with estimates of capital and operating costs drawn from published and other sources. Prospective costs of a farm-grown energy crop (switchgrass) delivered to a power plant are developed with the aid of a geographic information system (GIS) for agricultural regions in the North Central and Southeast US in the year 2000 and 2020. A simplified approach is applied to estimate the cost of delivering chipped eucalyptus from an existing plantation in Northeast Brazil. The optimum capacity (MW{sub opt}), defined as that which yields the minimum calculated cost of electricity (COE{sub m}), varies by geographic region due to differences in delivered biomass costs. With pressurized BIG/GTCC plants, MW{sup opt} is in the range of 230--320 MW{sub e} for the sites considered, assuming most of the land around the power plant is farmed for energy crop production. For atmospheric-pressure BIG/GTCC plants, MW{sub opt} ranges frommore » 110 to 142 MW{sub e}. When a lower fraction of the land around a plant is used for energy farming, values for MW{sub opt} are smaller than these. In all cases, the cost of electricity is relatively insensitive to plant capacity over a wide range around MW{sub opt}.« less

Integrated fuel cell electric power generation system for submarine applications

Abstract: An integrated electrochemical fuel cell power plant, including a fuel processing subsystem is suitable for use in a submarine. Selection and control of operating temperatures and pressures in the various subsystems and components of the fuel cell power plant are important aspects of submarine power plant design. A catalytic burner is used to heat a heat transfer fluid, which in turn is used to heat a vaporizer and reformer in the fuel processing subsystem. A hydrogen separator is used to obtain a substantially pure hydrogen fuel stream from the reformate stream, which is directed to and recirculated through the fuel cell stack in a closed-loop. The fuel processor is operated at high pressure which facilitates the discharge of waste exhaust streams overboard, and the fuel cell is operated at a substantially lower pressure.

Web based system and method to automate storage of power plant data and calculation of battery reserves

Abstract: A system and method for remotely inputting power plant data into a database and for calculating reserve times for which power plants can supply power to consumer equipment. The system includes a data input module for receiving power data from a remote user and for inputting power plant data into a database. In a preferred embodiment, the system is an integral part of a comprehensive site planning facility and interfaces with a permanent site facility database and a temporary relational database. Both databases store data relating to sites, power plants associated with sites and component data related to power plants. The data input module permits users to add, modify and remove power plant data associated with sites which are stored in the temporary relational database. The data input module also permits users to edit consumer equipment load values associated with power plants, regardless of whether data for associated sites are maintained in the site facility planning database or the temporary relational database. A calculation module retrieves data from the database and calculates reserve times for which power plants can supply power to consumer equipment. As a precautionary measure, the calculation module preferably employs correction factors which exaggerate consumer equipment loads and underestimate power plant reserve time. Users interface with the system via a web browser interface thus permitting users to access the system from any computer running a browser and connected to a company-wide intranet or the like. In an alternative embodiment, the system implemented is a stand-alone system in which only the temporary relational database is employed.

Hemispheric moving focus power plant apparatus and method

Abstract: A hemispheric moving focus power plant (10) has a hemispheric solar reflector (12) for reflecting solar energy. A receiver (14) for receiving reflected solar energy and producing power therefrom is movably connected to the hemispheric solar reflector (12). The receiver (14) includes a frame with a top (24), to which a plurality of photovoltaic cells are connected, and a support (26). Further, a power conditioner (16) is connected to the receiver (14) for receiving power from the receiver (14) and conditioning the power for use.

Standard Handbook of Powerplant Engineering

Abstract: Section I: Energy Resources for Power Generation. Overview of U. S. Energy Resources. Coal. Oil and Natural Gas. Nuclear Energy. Hydroelectric Energy. Solar Energy. Geothermal Energy. Wind Energy. Biomass Energy. Waste Fuels. Section II: Steam Powerplants. Steam Fundamentals. Basic Powerplant Design. Steam Generators. Boiler Auxiliaries. Cooling Towers and Air-Cooled Condensers. Water Treatment. Section III: Prime Movers. Steam-Turbine Fundamentals. Steam-Turbine Design. Gas-Turbine Fundamentals. Gas-Turbine Design. Hydraulic Turbines. Oil- and Gas-Fired Reciprocating Engines. Section IV: Plant Electric Systems. AC Generators and Generator Protection. Transformers and Transformer Protection. Electrical Interconnections. In-Plant Electrical Distribution. AC Motors and Their Applications. Busway Applications. Cable Applications. Section V: Instrumentation and Control. Powerplant Instruments. Combustion Control and Burner Management. Turbine and Engine Governors. Key Systems and Components. Human Engineering: Human-Machine Interface. Section VI: Nuclear Plant Systems. Introduction. Fission Theory. Nuclear Steam Supply Systems. Nuclear Plant Operation, Maintenance, and Control. Reactor Safety. Regulation. Section VII: Hydroelectric Power Stations. General Features of a Hydroelectric Project. Dams, Spillways, Water Conductors, and Powerhouses. Auxiliary Mechanical Equipment. Hydroelectric Generators, Transformers, and Controls. Section VIII: Alternative Energy Plants--Emerging Technologies. Solar Power Systems in Space. Geothermal Power Systems. Wind Energy Technology. Wood/Biomass Powerplants. Waste-Fired Plant Design. Fuel Cell Plants. Section IX: Environmental Controls. Environmental Legisation and Regulation. Air Emission Controls. Water Emission Controls. Solid Waste Management. Powerplant Noise and Its Control. Section X: Appendices: Conversion Factors. Standard Nominal System Voltages and Voltage Ranges. Abbreviations.

A logistical model for performance evaluations of hybrid generation systems

Abstract: In order to evaluate fuel and energy savings, and to focus on the problems related to the exploitation of combined renewable and conventional energy resources, a logistical model for hybrid generation systems (HGSs) has been prepared. A software package written in ACSL, allowing easy handling of the models and data of the HGS components, is presented. A special feature of the proposed model is that an auxiliary fictitious source is introduced in order to obtain the power electric balance at the busbars during the simulation stage, as well as in the case of ill-sized components. The observed unbalanced powers are then used to update the system design. As a case of study, the simulation program is applied to evaluate the energetic performance of a power plant relative to a small isolated community, an island in the Mediterranean Sea, in order to establish the potential improvement achievable via an optimal integration of renewable energy sources in conventional plants. Evaluations and comparison among different sized wind, photovoltaic and diesel groups as well as of different management strategies have been performed using the simulation package and are reported and discussed aiming to present the track followed to select the final design.

Systems to optimise conversion efficiencies at Ontario Hydro's hydroelectric plants

Abstract: Optimal dispatch systems at hydroelectric power plants manage the energy conversion process such that, under all conditions, the power station efficiency is maximised. This paper describes an optimal dispatch system which has proven to be successful at two Canadian installations, one on the Nipigon river controlling three stations near Thunder Bay, Ontario, and the other at R.H. Saunders generating station on the St. Lawrence river near Cornwall, Ontario. The validated benefits amount to 156 Wh per year, which is about 0.25% of the annual production at the respective stations. Secondary benefits arising from this system include increased decision making assistance, improved accessibility to plant data, and an overall improvement in the operational performance.