Showing papers on "Electricity generation published in 1986"

Quasi-Optical Power Combining of Solid-State Millimeter-Wave Sources

Abstract: Very efficient power combining of solid-state millimeter-wave sources may be obtained through the application of quasi-optical resonators and monotfthic source arrays. Through the theory of reiterative wavebeams (beam modes) with application of the Lorentz reciprocity theorem, it is shown that planar source arrays containing 25 individual elements or more result in very efficient power transfer of energy from the source arrays to the fundamental wave-beam mode. It is further shown that for identical sources within a properly designed quasi-optical power combiner, the output power tends to increase much faster that number of source elements.

Battery Energy Storage Another Option for Load-Frequency-Control and Instantaneous Reserve

Abstract: Energy storage plants utilizing batteries and thyristor power converters can be operated like pumped hydro storage units. Under the conditions actually prevailing in Europe, load leveling operation of such plants is not economical. Nevertheless, a battery energy storage plant promises both operational and economical advantages for load-frequency-control and instantaneous reserve operation. Queries according to this unconventional operation of batteries have been settled in a test facility in Berlin (West). After two years of test operation a decision was made to build up a full-scale demonstration plant, which will be commissioned in early 1987.

Novel process for direct conversion of free energy of mixing into electric power

Abstract: Direct conversion of salinity gradients into electric power as well as production of an acid and a base, simultaneous to generation of electricity, was investigated. Devices that combined features of an electrodialytic pile with those of fuel cells or of electrochemical half cells were designed. Electrodes of the electrochemical half cells were restored to their initial condition by simple reversal of the flow pattern. Fuel cells in the investigated system used water as the fuel and air as the oxidant. Energy extracted from salinity gradients at power density of up to 1 W/m/sup 2/ of the membrane yields up to 0.6 MW of electric power per m/sup 3//s of river or brackish water. Sodium hydroxide is obtained in an amount which corresponds to the number of coulombs of electricity generated in the process. Part of the produced HCI is, however, lost.

Solar collector, transmitter and heater

Abstract: A Solar Power collector, sunfollower, power transmitter and receiver is described. The Solar power collector is a Cassegrain Reflector optical system mounted on a carriage travelling on a semicircular track. A small photovoltaic cell and rechargeable battery provide the power to position the collector. A computer, sensors, electronic circuit and two servomotors provides accurate alignment of the collector with the sun's rays during the day, and returns it to follow the sun again the next morning. Sun-power is preferably transmitted from the collector via a light-pipe to a cavity where it is converted to heat-power. The heat-power may be stored as heat energy in a phase change material at a suitable temperature for cooking or other uses, such as heat-electric power generation. A plurality of collector-sunfollowers may transmit light-power to a single cavity heat storage depot, from which heat-power may be supplied on demand to various utilities.

A Monte-Carlo Simulation Method for the Economic Assessment of the Contribution of Wind Energy to Power Systems

Abstract: A method for determining the costeffectiveness of wind energy and the economic limitations of penetration into electrical power systems is presented. It is based on a Monte-Carlo approach which simulates the hour-by-hour operation of the power system. The hourly random variations in wind and load are modeled in addition to the operating constraints inherent in conventional generation. The economic assessment is based on a selected one-year simulation period, Two examples of the application of this method are given.

Electric machine dynamics

Abstract: Boldea and Nasar present a treatment of electric machine dynamics pertaining to modern static-power electric drives and electric power generators. They introduce a mathematical approach (such as that based on the orthogonal axis machine model), and include numerous examples that illustrate the analysis methods discussed. CONTENTS: Fundamentals of Electromechanical Energy Conversion. Electric Machine Models. DC Commutator Machines. Synchronous Machines. Induction Machines.

Retrofit SO2 and NOx control technologies for coal‐fired power plants

Abstract: The United States currently depends on coal for over half of its electric power generation. Current legislative and regulatory initiatives related to acid rain and other environmental concerns have focused on retrofit controls on existing plants and increasingly stringent requirements for new plants. This paper focuses on some of the technological approaches United States utilities are using and could be using in the future to generate electric power cleanly and reliably. Those technologies discussed include precombustion controls (physical coal cleaning and coal switching/blending), combustion controls (low NOx combustion, furnace sorbent injection, and fluidized bed combustion), and postcombustion controls (flue gas NOx control, wet and dry flue gas desulfurization, and post-furnace dry sorbent injection) The commercial status, economics, and critical issues for retrofit and new commercial application of these technologies to utility systems are discussed.

Nuclear Energy Cost Data Base: A reference data base for nuclear and coal-fired powerplant power generation cost analysis

Abstract: A reference data base and standard methodology are needed for performing comparative nuclear and fossil power generation cost analyses for the Department of Energy, Office of Nuclear Energy. This report contains such a methodology together with reference assumptions and data to be used with the methodology. It is intended to provide basic guidelines or a starting point for analyses and to serve as a focal point in establishing parameters and methods to be used in economic comparisons of nuclear systems with alternatives. The data base is applicable for economic comparisons of new base load light-water reactors on either the current once-through cycle or self-generated recycle, high- and low-sulfur coal-fired plants, and oil- and natural gas-fired electric generating plants coming on line around the turn of the century. In additions to light-water reactors and fossil fuel-fired plants, preliminary cost information is also presented on liquid metal reactor plants. This report includes a data base containing proposed technical and economic assumptions to be used in analyses, discussions of recommended methodology to be used in calculating power generation costs, and a sample calculation for illustrative benchmark purposes.

Process for electric power production using a biogas

Abstract: Electric power is produced in an electric power generating combustion turbine using a biogas as fuel thereto, where a biogas, leaving a biomass gasification system at an elevated temperature of 650°-875° C. and containing tars, is partially cooled by injection of a spray of water thereto to a lower temperature of about 260°-555° but above that which would condense tars. The partially cooled biogas stream is then filtered to remove solid particulate matter therefrom and is directly charged as fuel to the electric power producing combustion turbine for the production of electric power.

Shock-Expansion Wave Engines — New Directions for Power Production

Abstract: For decades large amounts of money and effort have been spent on conventional turbomachinery development. Initially improvements in performance were rapid. However, in the last two decades better performance of these machines has slowed considerably. Compressor efficiencies have been near their present limits of 88% to 92% for many years. High pressure ratios required of high performance engines are not efficiently produced in the conventional turbomachines. High pressure ratios for high cycle efficiency require many stages of conventional compression. Compressors, especially in small turbomachines, decrease in efficiency as the number of stages increase due to the large amounts of surface area and relatively large leakage passages in the higher pressure stages.The requirement for many stages of conventional compression also results in heavy machines. If high compressor pressure cannot be attained the turbine exhaust gas temperature may be considerably above the compressor discharge temperature; a regenerator or recuperator is then required for acceptable cycle efficiency. This results in considerable complication and high engine weight.Maximum turbine inlet temperatures in conventional machines have also been near their limit for many years. High temperatures and high pressures required for light weight, high efficiency machines are inconsistent with the requirements for high strength materials. To increase permissable turbine inlet temperatures compressor discharge air is used for blade cooling. Use of this air soon reaches its limit because the high pressure cooling air is then not available for power production. Engine power and cycle efficiency begins to decrease and a limit on turbine inlet temperature results.Consequently, new concepts in power and thrust production are required. One class of machines which may alleviate many of the above described problems are the wave rotors or engines (1 thru 15). These operate with time dependent flow in the moving rotor blade passages and steady flow in the stator parts.Copyright © 1986 by ASME

Alternative power generation concepts for space

Abstract: Trade and optimization studies that highlight the potential of solar and nuclear dynamic systems relative to photovoltaic power systems are summarized. The solar dynamic case is the LEO Stirling system, while the nuclear system is the SP-100 system goal. Nuclear systems have the potential for the lightest weight, least area, sunlight independent, radiation-durable system. Solar dynamic systems pose a stiff challenge to photovoltaic systems in the midaltitudes because of their insensitivity to the Van Allen radiation belts. While the initial operational capability space station power system is only slightly superior to the SOA PV system, with development focused on the key technologies, advanced solar dynamic systems are fully competitive in LEO midaltitudes with the advanced photovoltaic systems. Advances in energy storage systems (100 Whrs/kg required) are essential.

Energy efficient process for viscous oil recovery

Abstract: A process for viscous oil recovery from a subsurface formation wherein the electric power is generated by burning combustible material and the electric power is passed through the formation via electrodes, preferably producing wells, to apply heat to the oil and reduce its viscosity. Simultaneously therewith, the hot flue gas is used to heat water which is injected into the formation to apply heat to the formation, or reduce loss of the heat created by the electric current, or to force oil toward the producing wells, or any combination thereof.

An optimal planning method for a marine heat and power generation plant by considering its operational problem

Abstract: The objective of this paper is to develop a computer-aided optimal planning method for designing a marine heat and power generation plant which is composed of combining Diesel and turbogenerators, an exhaust gas economizer, auxiliary boilers and so forth. As there exist many alternative combinations concerning generators and boilers in constructing the abovementioned plant, it is important to determine the plant construction properly by selecting total numbers and scales of respective generators and boilers so as to optimize the long-term economy of the plant. In this planning method, several design conditions are first set which are necessary for the planning of the objective plant, i.e. several patterns of ship's operational condition are set first, and both energy demands and steam output from an exhaust gas economizer are estimated for each pattern. Next, setting an alternative plant composed of combining generators and boilers adequately, the optimal operational policy for each pattern is determined by minimizing the fuel cost under several physical constraints based on linear and quadratic programming methods. Considering the results obtained above hierarchically, annual capital and operational costs of each plant are calculated, and the best plant construction is lastly determined by comparing the economy of all alternative plants. A numerical study has been carried out on a plant of a high speed container ship actually planned, and it is ascertained that to find the best construction of the plant the optimal planning method proposed here is advantageous compared with the conventional trial and error method.

Daily Operational Planning of the EDF Plant Mix Proposal for a New Method

Abstract: Lagrangian relaxation in the service of the operational planning of an electric power plant mix How can the daily operational planning of an electric power plant mix using thermal and hydraulic equipment be optimized ? The approach adopted in this paper makes it possible to take into account thoroughly the operating constraints of generation units and those of valleys. The approach provides a quasi-optimum solution to the problem. In addition to the generation schedules, it determines the daily plant discharge and the trade-off between thermal and hydraulic spinning reserves. The method used is that of the decomposition-coordination by prices, or Lagrangian relaxation. The global problem is broken down into two classes of local subproblems: - optimum planning of each thermal unit using dynamic programming, - optimum planning of each hydraulic valley using linear programming. All the local subproblems are coordinated among themselves by the costs of energy and the spinning reserve, which are dual variables associated with the corresponding constraints.

Co-Ordinated Governor/Exciter Stabilizer Design in Multi-Machine Power Systems

Abstract: This paper describes the application of multi-variable control design methods to the problem of designing co-ordinated stabilizers in a multi-machine environment. Linear state space methods are used to design co-ordinating stabilizing inputs for the exciter and governor loops, based on a number of local outputs. The dynamics of the multi-machine power system are taken into account by determining a dynamic equivalent model of the power system as seen from the transformer bus of the design generator. This is accomplished using identification techniques as described in a previous paper[2]. The generator equations are linearized and combined with this dynamic equivalent of the remainder of the power system, resulting in a reduced order representation of the combined system. Linear optimal control methods are then used to determine the co-ordinated controller. The effects of nonlinearities are taken into account by experimenting with different cost function weightings. The method is demonstrated by applying it to a generating station in an example 63 bus power system with a total of 59 generators represented.

Investigation of Loss of Generation Disturbances in the Florida Power and Light Company Network by the Transient Energy Function Method

Abstract: This paper deals with the investigation of the loss of generation disturbances by the transient energy function (TEF) method. It describes the modeling of the loss of generation disturbance and the post-disturbance conditions. A technique for simulating the out-of-step impedance relay operation following loss of generation is developed and the transient energy margin obtained from the TEF method is related to the out-of-step impedance relay setting. The procedure is applied to two cases of loss of generation in the Florida Power & Light Company network.

Synthesis gas generation complex and process

Abstract: A synthesis gas-power generation complex is disclosed, the complex being characterized by ability to generate sufficient electrical power for internal use and for export, and by structure for improved heat recovery and utilization. A process for synthesis gas production and power generation utilizing these concepts is also disclosed.

Design of Rankine Cycles for power generation from evaporating LNG

Abstract: Of the different ways of using the cold available from the large scale evaporation of LNG the generation of electric power, using the Rankine Cycle, appears the most practical. Fourteen such plants have so far been installed in Japan. The present study was undertaken for a plant at Zeebrugge. Six different cycles using nine different refrigerants and mixtures were examined. The results ( Tables 2 and 3 ) show the importance of using a heat source with the highest possible temperature. No one refrigerant is ideal for all configurations Environmental and safety considerations also affect the choice of refrigerant.

Integrated fuel cleaning and power generation

Abstract: Disclosed is a method for the generation of electricity or propulsive power from fossil-fuels which combines fuel cleaning with a thermodynamic cycle utilizing two or more combustors which fire the differing quality streams from the fuel cleaning plant. The method accomplishes emissions reduction at good energy conversion efficiency and a reduced overall plant equipment cost.

Development of Superconducting AC Generator

Abstract: The superconducting ac generator is expected to be the optimum choice among ac generation systems in the future because of its reduced size, weight, high efficiency, and its contribution to stability of power systems and higher generator terminal voltage. Conceptual design on a 2P-1000MVA class superconducting ac generator has been completed to clarify problems and to confirm advantages. Fundamental studies are performed on key technologies that have to be solved for realization of superconducting generators. As a summary of those fundamental studies, a scaled-down superconducting generator of 3000kVA capacity is constructed and tested. Also clarified are effects of major design parameters for commercial superconducting ac generators such as dimensions, reactances, and weight.

Materials and electricity

Abstract: Despite an increase in the intensity of electricity usage, electricity has been reversing its historical trend of reduced cost since 1970 to the point where costs are increasing faster than inflation. Designers and operators on both sides of the meter and the developers of materials from which the electric system is constructed must contribute to the lowering of costs and an increase in reliability for the generation, transmission and distribution, and utilization of electricity. Four specific cases illustrate the role of materials/process improvements to this end. The examples highlight the use of forged or welded integral rotors, improvements in the heat rate of coal-fired plants through higher steam conditions and reduced heat losses, reduced losses through amorphous steel cores for transformers, and reduced ac electric motor losses through silicon variable speed drives. 37 references, 27 figures, 9 tables.

Coal Gasification Systems for Power Generation

Abstract: Coal gasification systems have desirable features that recommend their consideration for use in providing fuel and steam for generating electric power. They have advanced from laboratory developments to mature technologies for providing efficient, cost-competitive power generation. The continued halt in nuclear power deployment, the uncertain availability and cost of natural gas and oil, the likelihood of increasingly severe environmental regulation of power plant air emissions and solid waste disposal, and uncertainties in the rate of growth of electric power demand are factors that favor deployment of smaller, modular capacity additions based on alternative coal-fueled power systems.

Method and device for geothermal electric power generation

Abstract: PURPOSE:To make a water circulating system for taking out geotherm unnecessary and reduce the installation cost of the plant by a method wherein one end of a heat pipe is inserted into a geotherm reserving layer under the ground and the geothermal is taken out to converter the heat energy thereof into an electric energy. CONSTITUTION:The heat pipe 15 is consisting of heat absorbing fins 16, heat radiating fins 17 and a heat insulating member 18. Heat, absorbed from the geotherm reserving layer B by heat absorbing fins 16, is transferred to heat transfer medium through the heat radiating fins 17 and the heat exchanger 20 of a steam cycle 13 and rotates a turbine 21 to operate an electric generator 14 and generate electric power. The working fluid, effected an adiabatic expansion in the turbine 21, is sent into a condenser 22 and, thereafter, is sent into the heat exchanger 20 by a pump 23.

Gasification apparatus for biomass fuel gasification compound power generation

Abstract: PURPOSE:To remarkably improve follow-up ability in response to the fluctuation of electric power generating load by providing a boiler the heat source of which is exhaust gas and an auxiliary fuel supplying device in a gasification apparatus having a reactor, a burner reactor and a gas/solid separator. CONSTITUTION:In a biomass fuel gasification compound power generation apparatus comprises and formed by a gasification device 1, a gas turbine power generation plant 2, a waste heat boiler 3 and a steam turbine power generation plant 4, the boiler 13 is integrally provided on the top of a burner reactor 12 which heats flowing medium and auxiliary fuel such as coal, etc. is supplied from a auxiliary fuel supplying device 19 to the burner reactor 12 for burning. In case that the load of power generation increases, auxiliary fuel supply quantity is adjusted to increase an amount of generation of high pressure steam so as to increase an amount of power generation of the steam turbine power generation plant, for quickly making the power to follow the increase of the load of power generation. And in response to the increase of power generation, the amount of power generation by the gas turbine power generation plant 2 is increased and simultaneously, the auxiliary fuel quantity of the burner reactor 12 is decreased to operate the whole power generation apparatus economically.

Simulation of Permanent Magnet Generator/Rectifier Combination

Abstract: Permanent magnet generators are often used as the pilot exciters of three-stage generating units to provide an efficient and reliable source of electrical power. No external power supply is then necessary, and the problems associated with brushwear and with arcing at the rubbing contacts are eliminated. A technique is presented here by which the performance of a permanent magnet generator, when combined with a rectifier-fed d.c. load at its output terminals, may be accurately and efficiently computed. The machine model takes into account the magnetization characteristic of the permanent magnet rotor and involves only parameters which can be determined from terminal measurements on the machine at standstill. Both computed and measured characteristics for an experimental machine are presented, and a comparison of these characteristics shows that the model can predict accurately all the major characteristics of the machine, as well as its detailed internal performance, when supplying a typical resistiveinductive load.