Showing papers on "Power station published in 1994"

Hydrocarbon fueled solid polymer fuel cell electric power generation system

Abstract: A power plant system (110) produces utility grade electrical AC power from gaseous or liquid hydrocarbon fuels using a fuel cell stack (186) employing ion exchange membranes. The fuel is desulfurized, mixed with water, heated and vaporized before being introduced into a reformer (168). The reformer (168) produces a hydrogen-rich gas (51) which is then directed through a series of heat exchangers (164), shift converters (172) and a selective oxidizer (142). The processed fuel stream is combined in the fuel cell stack (186) with a pressurized oxidant stream to generate DC power. Oxidant pressure is supplied by compressors (130, 134) driven by turbines using heated system exhaust gases. The DC power is converted into utility grade AC power (195) using an inverter (210) augmented by a battery peaking unit (212) for rapid load following. The water generated in the fuel cell stack (186) is recycled and used to cool the fuel cell stack and to humidify the fuel stream and oxidant stream prior to their introduction to the fuel cell stack (186).

CO2 capture from the flue gas of conventional fossil‐fuel‐fired power plants

Abstract: Research has been conducted at Argonne National Laboratory to identify and evaluate the advantages and deficiencies of several technologies, both commercially available and alternative technologies, for capturing CO[sub 2] from the flue gas of utility boilers that use air as an oxidant (the current universal practice). The technologies include chemical solvent, cryogenic, membrane, physical absorption, and physical adsorption methods. In general, technologies for capturing CO[sub 2] are expensive and energy-intensive. Therefore, they result in a substantial overall increase in the cost of power generation. Research to improve the performance and economics of these technologies is discussed. 20 refs., 6 figs., 1 tab.

Application of wind speed forecasting to the integration of wind energy into a large scale power system

Abstract: The use of numerical weather prediction (NWP) model as used by national meteorological agencies is assessed in conjunction with a physical flow model and a statistical model as a means of predicting wind power that could be generated by a large number of wind turbines spread throughout the UK. Economic benefits have been demonstrated, and are evaluated in the form of fossil fuel savings using a numerical simulation model which emulates the power plant scheduling of the England and Wales National Grid. The results highlight the importance of effective planning of on-line reserve capacity to cover sudden deficits in wind power generation.

A modular power station for the production primarily of hydrogen from solar energy and a method of generating electric energy

Abstract: A modular power station for the production primarily of hydrogen from solar energy. A conversion module converts solar energy into biomass which is gasified in a gasification module and the hydrogen resulting from the gasification is separated out and stored. The hydrogen can be used for generating electrical energy in a fuel cell.

Method of operating a combination power plant by coal or oil gasification

Abstract: In a method for operating a combined cycle power plant with coal or oil gasification, wherein the oxygen required for gasification is supplied by an air separation plant, the air required for the air separation plant is condensed in a first, separate condenser and is cooled in a heat exchanger prior to being supplied to the air separation plant. Only enough nitrogen produced in the separation plant is supplied to the gas turbine combustion chamber as the surge limit of the compressor permits. The remaining portion of the nitrogen is expanded to ambient pressure in an expander after exiting the air separation plant.

Tampa Electric Company`s Polk Power Station Integrated Gasification Combined Cycle Project

Abstract: Tampa Electric Company (TEC) is in the construction phase for the new Polk Power Station, Unit {number_sign}1 This will be the first unit at a new site and will use Integrated Gasification Combined Cycle (IGCC) technology for power generation The unit will utilize oxygen-blown entrained-flow coal gasification, along with combined cycle technology, to provide nominal net 26OMW of generation As part of the environmental features of this process, the sulfur species in the coal will be recovered as a commercial grade sulfuric acid by-product The sulfur will be removed from the synthesis gas utilizing a cold gas clean-up system (CGCU)

Hybrid central receiver

Abstract: A hybrid combined cycle power plant including a solar central receiver (7) for receiving solar radiation and converting it to thermal energy The power plant includes a molten salt heat transfer medium (8) for transferring the thermal energy to an air heater (9) The air heater (9) uses the thermal energy to preheat the air from the compressor (12) of the gas cycle The exhaust gases from the gas cycle are directed to a steam turbine (16) for additional energy production

Compressor Washing Maintains Plant Performance and Reduces Cost of Energy Production

Abstract: This paper reports about the results of a field test conducted over a period of 8000 operating hours on the effect of combined on line and off line compressor washing on a 66 MW gas turbine operating in a combined cycle plant at UNA’s Lage Weide 5 power plant in Utrecht. Observations have shown a sustained high output level close to the nominal guaranteed rating, despite difficult atmospheric conditions. Investigations on the correlations between fouling gradients in the compressor and atmospheric conditions are also presented. The evaluation of the results demonstrate the importance of implementing an optimised regime of on line and off line washing in the preventive turbine maintenance program. It will improve the plant profitability by reducing the costs of energy production.Copyright © 1994 by ASME

Sea/river powered power plant

Abstract: A sea/river powered power plant that harnesses the movement of sea waves and river currents to convert them into useful electrical energy. The power plant contains turbines which rotate about a horizontal axis as the waves and currents strike a lower portion thereof, so to turn a shaft, which eventually operates a driven shaft of an electric generator.

Heating installation which additionally generates electrical energy

Abstract: There exist installations which burn fuel and generate both electrical and thermal energy. In the emergency generating set, the electrical energy is generated only for one's own requirements; in the heating and power station, the thermal energy is transported to the surrounding area as long-distance heat. Transportation of long-distance heat is expensive and requires an independent pipeline system, the transportation of electrical energy on the other hand is simple and can use the existing network. Based on this, the invention sets itself the object of providing a heating installation which consumes the generated thermal energy for heating one's own house and feeds electrical energy which has not been consumed by oneself into the general network. The network is thus relieved in times of peak demand. The invention solves this object by virtue of the fact that a Stirling motor (hot-gas motor) (10) which receives its inflow heat via the burner (6) and delivers its outflow heat to the heating circuit (1, 2, 3, 4, 5) is coupled to an electrical machine (12) which in the operating state works as an asynchronous generator and in the starting state works as an asynchronous motor. The concept of the invention can be applied in principle to any fuel-fired domestic heating installation.

Combined cycle power plant

Abstract: PURPOSE: To provide a device for recovering waste heat from a gas turbine in a combined cycle power plant. CONSTITUTION: A waste heat recovering device 12 has a first waste heat recovering system 38 and a second waste heat recovering system 40. The first waste heat recovering system 38 heats the condensate of a steam turbine cycle with heat from hot exhaust gases from a gas turbine 14. The second waste heat recovering system 40 heats fuel used in the gas turbine 14 with heat from the exhaust gases. The second waste heat recovering system 40 can recover heat energy that is not recovered by the first waste heat recovering system 38, thereby the efficiency of a power plant can be improved. COPYRIGHT: (C)1995,JPO

Combined-cycle power tower

Abstract: This paper evaluates a new power tower concept that offers significant benefits for commercialization of power tower technology. The concept uses a molten nitrate salt centralreceiver plant to supply heat, in the form of combustion air preheat, to a conventional combined-cycle power plant. The evaluation focused on first commercial plants, examined three plant capacities (31, 100, and 300 MWe), and compared these plants with a solar-only 100-MWe plant and with gas-only combined-cycle plants in the same three capacities. Results of the analysis point to several benefits relative to the solar-only plant including low energy cost for first plants, low capital cost for first plants, reduced risk with respect to business uncertainties, and the potential for new markets. In addition, the concept appears to have minimal technology development requirements. Significantly, the results show that it is possible to build a first plant with this concept that can compete with existing gas-only combined-cycle plants.

Arrangement in combined-cycle power plant

Abstract: An arrangement for increasing the overall efficieny by utilizing waste heat in a combined-cycle power plant in which a first electric generator (1) is powered by a supercharged internal combustion piston engine (3), the exhaust gases (5) whereof being conducted through a gas turbine driving the supercharger (6) for the intake air (8) of the engine and a steam boiler (10) for generating pressurized steam (15), said steam being conducted through a steam turbine (4) connected to a second electric generator (2) further into cycle. The exhaust gases of the internal combustion piston engines are conducted from the engine first (5a) into the steam boiler (10) at a pressure essentially higher than the atmospheric pressure and only thereafter (5b) into the gas turbine or turbines of the supercharger (6) for the intake air (8), where they expand into the atmospheric pressure in order to increase the efficiency of the elctricity production of the combined-cycle power plant.

Exergetic Comparison of Two KRW-Based IGCC Power Plants

Abstract: In studies supported by the US Department of Energy and the Electric Power Research Institute, several design configurations of Kellogg-Rust-Westinghouse (KRW)-based Integrated Gasification-Combined-Cycle (IGCC) power plants were developed. Two of these configurations are compared here from the exergetic viewpoint. The first design configuration (case 1) uses an air-blown KRW gasifier and hot gas cleanup while the second configuration (reference case) uses an oxygen-blown KRW gasifier and cold gas cleanup. Each case uses two General Electric MS7001F advanced combustion turbines. The exergetic comparison identifies the causes of performance difference between the two cases: differences in the exergy destruction of the gasification system, the gas turbine system, and the gas cooling process, as well as differences in the exergy loss accompanying the solids to disposal stream. The potential for using (a) oxygen-blown versus-air-blown-KRW gasifiers, and (b) hot gas versus cold gas cleanup processes was evaluated. The results indicate that, among the available options, an oxygen-blown KRW gasifier using in-bed desulfurization combined with an optimized hot gas cleanup process has the largest potential for providing performance improvements.

Computer-Integrated Construction

Abstract: Computers have been used quite successfully as replacements for manual drafting, but to stop there seriously underuses the potential of computer aided design. By using the computer's rendering capabilities to design in three-dimensions, engineers get a more accurate idea of how the parts they are designing fit into the scheme for the overall structure. Interferences, difficulties in placement and construction, and the materials required are all more apparent when the entire object is viewed. Recently, Stone & Webster, Inc., New York, used its Construction Management Display System (COMANDS) to help design the retrofitting of the pollution control system on a Tebbessee Valley Authority powerplant. By designing in three-dimensions, we were able to simulate the construction ahead of time, showing the construction managers what we had planned, sequence the work properly and minimize outage time. With these advantages, we were able to come in on-time and under budget.

Exergoeconomic Evaluation of a KRW-Based IGCC Power Plant

Abstract: In a study supported by the U. S. Department of Energy, several design configurations of Kellogg-Rust-Westinghouse (KRW)-based Integrated Gasification-Combined-Cycle (IGCC) power plants were developed. One of these configurations was analyzed from the exergoeconomic (thermoeconomic) viewpoint. This design configuration uses an air-blown KRW gasifier, hot gas cleanup, and two General Electric MS7001F advanced combustion turbines. Operation at three different gasification temperatures was considered. The detailed exergoeconomic evaluation identified several changes for improving the cost effectiveness of this IGCC design configuration. These changes include the following: decreasing the gasifier operating temperature, enhancing the high-pressure steam generation in the gasification island, improving the efficiency of the steam cycle, and redesigning the entire heat exchanger network. Based on the cost information supplied by the M. W. Kellogg Company, an attempt was made to calculate the economically optimal exergetic efficiency for some of the most important plant components.

Modelling of Vertical Spindle Mills in Coal Fired Power Plants

Abstract: A mathematical model of a vertical spindle mill used in coal-fired power plant is presented. The model is developed based on a mill size mass balance (SMB) and mill global mass and energy balances. The model has been validated using data collected from a 660 MW unit during mill modelling field tests. The model can be used to perform mill dynamic performance studies, design and evaluate new mill dynamics on power plant control and response.

Energy Demand and Climate Change: Issues and Resolutions

Abstract: Acknowledgements Prologue PART I: QUESTIONS Introduction Ancient Days and Modern Times Ice Ages - Past and Future Global Warming versus Returning Glaciers Earth's Fossil Fuel Supply Nuclear Power PART II: ANSWERS Introduction Solar Energy Wind, Waves, and Tides Going with the Flow: Water, Dams, and Hydropower Geothermal Energy: Energy from the Earth Itself Efficiency, Conservation, and Hybrid Cars Energy Storage: Macro to Micro Green Fuel: Biodiesel, Alcohol, and Biomass PART III: DREAMS Introduction Breeding Nuclear Fuel Nuclear Fusion: Engine of the Sun Power from the Ocean: Thermal and Salinity Gradients Fuel Cells: Hydrogen, Alcohol, and Coal Magnetohydrodynamics and Power Plants Thermionics and the Single Fuel Home Artificial Photosynthesis and Water Splitting Planetary Engineering and Terraforming Space Solar Power: Energy and the Final Frontier PART IV: NIGHTMARES Introduction Alternative Futures ORBITuary? Disasters That Could Occur

Underground power plant

Abstract: Underground powerplant system for the generation of energy, in particular electrical energy, comprising a coal fired steam generator, whose steam drives a turbine which delivers electrical energy. The coal-fired steam driven electrical generation system of the invention is installed underground in a coal mine. Waste fly ash (with or without sorbent) bottom ash and slag can be disposed in the abandoned or exhausted mining area. Ambient mine water can be employed in one or more of the process operations.

Adaptive predictive control in a thermal power station

Abstract: This article presents the application of the predictive adaptive control system (SCAP) to the control and optimization of the processes in a coal power station. The results obtained, corresponding to a research and development project at the Pasajes de San Juan Power Station, which belongs to the company Iberdrola, demonstrate the suitability of the SCAP application in this field as well as the important benefits that may be derived from its application. >

Wind technology development: Large and small turbines

Abstract: Wind technology has been developing rapidly over the last decade. The experience gained in the wind farms of California is being used to design and develop advanced systems with improved performance, higher reliability, and lower costs. During the past several years, substantial gains have been made in wind turbine designs, lowering costs to an average of $0.05 per kilowatt-hour (kWh) for utility-scale applications at 13 mile-per-hour (mph) average annual wind speeds. Further technology qevelopment is expected to allow the cost of wind-generated electricity to drop below $0.04 per kilowatt-hour by 2000. As a result, wind is expected to be one of the least expensive forms of new electric generation in the next century. With global efforts already underway to curb energy-related emissions of carbon dioxide, the current availability of this low-cost technology means that the use of wind systems will likely increase worldwide throughout the 1990s for both utility-scale applications and remote, small-village applications. This paper will present the technology developments for both utility-scale wind turbines and remote, small-village wind turbines that are currently available or in development. The authors describe future technology improvements and likely wind turbine configurations in 2000. Technology innovations are being adapted for remote and stand-alone power applications with smaller wind turbines. Hybrid power systems using smaller 1to 50-kilowatt (kW) wind turbines are being developed for non-grid-connected electrical generation applications. These village power systems typically use wind energy, photovoltaics (PV), battery storage, and conventional diesel generators to supply power for remote small-village communities. In remote locations, transportation costs can make fuel-powered generating systems extremely expensive. Smaller wind turbines are also being explored for application as distributed generation sources on utility grids to supply power during periods of peak demand, avoiding costly upgrades in distribution equipment. New turbine designs now account for turbulence-induced loads, unsteady aerodynamic stall effects, and complex fatigue loads, making use of new technology developments such as advanced airfoils tailored for wind turbine applications. These new airfoils increase the energy capture and improve the operating efficiency of turbine rotors by increasing the power for a given rotor thrust, and reducing the sensitivity of the airfoils to roughness which naturally accumulates during operation. Technology has been developed which uses power electronics to allow variable rotor speed operation to improve efficiency. Aerodynamic control devices, such as ailerons and flaps, are being explored to aerodynamically modulate power or stop the rotor in high-speed conditions. These technology trends and future turbine configurations are being explored through research and development activities sponsored by the U.S. Department of Energy's (DOE's) Wind Energy Program. Utility-Scale Systems In the United States, utility-scale wind turbines are the primary focus of new technology development. By 1996, U.S. manufacturers will have introduced seven new turbines (with capacities ranging from 250 to 500 kW) for the utility market. Five of the turbines are being developed by members of the U.S. wind industry with direct funding support from DOE. Cannon Energy Corporation and Kenetech Windpower are each developing a utility-scale wind turbine independently. Two of the utility-scale wind turbines sponsored by DOE are commercially available: R. Lynette & Associates' A WT -26, and Zond Systems' Z-40. Northern Power Systems, New World Grid Power, and Flowind Corporation are expected to introduce their turbine designs within the next two years. R. Lynette & Associates' AWT-26 The 275-kW AWT-26 (Figure 1) is a downwind, stall-regulated, free-yaw machine incorporating an innovative two-bladed teetered rotor. The A WT -26 is bas(id upon the ESI-80, a turbine developed in the United States during the mid1980s which had many promising features, but never reached commercial maturity. The designers of the A WT -26 have taken advantage of the substantial operating history of its predecessor, retained components that were reliable, and improved the remainder. The larger 26-meter (m) rotor incorporates aerodynamically efficient, wood-composite blades using National Renewable Energy Laboratory (NREL) designed airfoils. The new blades improve the turbine's energy capture from 20% to 70%, depending on wind speed and the degree of blade soiling from dirt and insects. The A WT-26 also features a redesigned high-speed shaft brake and new aerodynamic tip vanes. The tip vanes serve two important functions on this turbine: as a fail-safe (emergency) brake and as an active brake for normal shut-down operations. Mounted on a hinge at the tip of each blade, the vanes are held closed by electromagnets. The vanes are activated by control system command, which releases the electromagnets. A redundant caliper disk brake can also stop the machine under normal or emergency conditions. The A WT -26 has been selected for a commercial 25-megawatt (MW) power plant to be installed in late 1995 in Washington state by a consortium of public utilities called CARES (Conservation and Renewable Energy Systems) as a project under the Bonneville Power Administration's Resource Supply Expansion Program (RSEP). The RSEP program was a competitive solicitation to add wind generation capacity to the Bonneville network. Northern Power Systems' North Wind 250 The 250-kW North Wind 250 (Figure 2) is a two­ bladed, teetered, upwind machine that has been scaled up from the company's North Wind 100 Figure 1. R. Lynette & Associates' 275-kW AWT-26. Figure 2. Northern Power Systems' 250-kW North Wind 250. turbine. The new turbine features an integrated drive train, aileron controls, and an innovative rotor that is fabricated as a single unit. The "flow-through" rotor eliminates the blade root joints, which are expensive, complicated, and subject to high stress during turbine operation. The unique, flow­ through, teetered-rotor design eliminates structural discontinuities at the blade/hub interface by fabricating the rotor as one continuous structural element. Fatigue tests were conducted on the full­ scale rotor joint at NREL to qualify this element of the rotor for field testing and to provide information needed to improve its structural design. The hub incorporates teeter dampers and an active teeter brake. The rotor is made of a hybrid composite material. The hub saddle captures the blade center section in a wrap-around elastomeric blanket. The new rotor also substitutes aileron control for the full-span pitch control system used in the earlier North Wind model. Ailerons, which work like flaps on an airplane wing, are the most important development featured in the North Wind 250. When deflected in the downwind direction, they reduce lift and power output. When power modulation is needed, the ailerons can be deflected through small angles to either increase or decrease power. Upwind deflections increase lift, causing the power to increase. Wind tunnel tests at Wichita State University have confirmed the ability of ailerons to control power and prevent the rotor from over-speeding.

The key role of heat exchangers in advanced gas-cooled reactor plants

Abstract: The use of helium as a nuclear reactor coolant has been successfully demonstrated in plants built and operated in the U.K., U.S.A., and Germany. Following the pioneering proof of principle plant, two small power plants were operated for several years and this led to the construction of two commercial power stations. For the next generation of gas-cooled reactors new criteria have been developed, namely, the plants will be smaller, simpler, safer and of lower cost. The base case Modular High-Temperature Gas-Cooled Reactor (MHTGR) utilizes existing technology to offer a tried and proven power generating plant using a conventional steam turbine power conversion system that could be in utility service just after the turn of the century. The capability of the MHTGR to operate at very high temperatures will be exploited early in the next century in the form of advanced variants to meet the needs of the power generation and process industries. A key component in the MHTGR is the heat exchanger, since this is where the reactor thermal energy is transferred to the prime-mover or process system. This paper addresses the various roles that heat exchangers will play in advanced MHTGRs, recognizing that the requirements for the steam cycle, gas turbine (direct- or indirect-cycle), and process heat reactor are unique. Topics include thermodynamic considerations, differing configurations, and construction types; materials (metals, composites, ceramics); germane technology bases; and advanced heat exchanger technologies.

Modular power plant for the generation of electrical energy from solar energy

Abstract: A modular power plant for the generation of electrical energy from solar energy. The principle structure consists of: a conversion module (1) for the conversion of solar energy into biological raw material, a gasification module (2) in form of a gasification reactor for the gasification of biological raw material, and a fuel cell module (3) for the conversion of gas into electricity using fuel cell technology. The conversion module (1) contains an aggregate (4) for harvesting biological raw material and a processing aggregate (5) for processing biological raw material into a gasification preproduct. The gasification module (2) is connected to the processing aggregate (5) via a supply unit (6). The fuel cell module is connected to the gasification module for cleaning of the fuel gas by a device (8). The performance of the gasification and fuel cell module has been designed in relation to the system performance, so that part of the fuel gas can be used for the water vapour production (12) and a further part and/or the waste heat of the modular power plant for the drying of harvested biological raw material.

Magnetic cage filters

Abstract: A new class of magnetic filters-magnetic cage filters (MCFs)-was designed and constructed. These filters were studied theoretically and experimentally as far as the capture and retention of fine particles of crud is concerned. High values of capture efficiency and retention capacity were obtained, making the MCFs well suited as passive magnetic filters for power station applications. >

Raw material and energy recovery from biomass

Abstract: Appts. for raw material and energy recovery from biomass has an anaerobic fermentation unit, an aerobic composting unit, a gasification unit and a power generating plant (esp. a block thermal power generating plant), together with lines for (a) excess water passage from the fermentation unit to the gasification unit and/or composting unit, (b) noxious material and unreacted and low quality solids passage from the fermentation unit and/or the composting unit to the gasification unit, (c) synthesis gas passage from the gasification unit to the power plant, (d) biogas passage from the fermentation unit to the power plant, (e) air passage from the composting unit to the power plant, (f) heat transport from the power plant to the fermentation unit, (g) current supply from the power plant to the composting unit and (h) external output of heat and/or current from the appts. Also claimed is a process for raw material and energy recovery from biomass using the above appts..

Application of nonlinear control to a HAWT

Abstract: Wind energy is one of the most promising sources of renewable energy for the UK. Over the last two decades there has been rapid development of the technology, and in the UK several commercial wind farms are in operation with more under construction. The standard commercial design of wind turbine is a horizontal axis grid-connected up-wind machine with a rating of approximately 300 kW. The rotor usually has two or three blades, and in pitch regulated machines the pitch angle of either the full span of the blades or just the outer tips can be varied. The application of a nonlinear controller to a typical two-bladed machine with full-span pitch control is investigated in the present paper. It is known that this particular configuration of wind turbine presents a more demanding control problem than alternative configurations, and the benefits of a more sophisticated control system are therefore expected to be greater in the two-bladed case. >