Showing papers on "Power station published in 1987"

SOLERGY; A computer code for calculating the annual energy from central receiver power plants

Abstract: The program SOLERGY was designed to simulate the operation and power output of a user-defined solar central receiver power plant for a time period of up to one year. SOLERGY utilizes recorded or simulated weather data and plant component performance models to calculate the power flowing through each part of the solar plant. A plant control subroutine monitors these powers and determines when to operate the various plant subsystems. Parasitic electrical power is computed on a 24-hour basis.

Integrated power plant and method for operating the plant

Abstract: An integrated power plant based on a molten carbonate type fuel cell and a gas turbine combined plant comprising a gas turbine, a steam turbine and a common generator driven by the gas turbine and the steam turbine is disclosed, where a reformer for a fuel gas to the anode of the fuel cell is heated through heat exchange with the cathode off-gas from the fuel cell to obtain the necessary heat for the reforming, and a portion of the anode off-gas from the fuel cell is combusted in a separate burner to form a CO2 recycle to the cathode, while most of the remaining anode off-gas is supplied to the gas turbine combustor. The existing gas turbine combined plant can be used, as it is, without any substantial modification, and the present fuel cell power generation plant can be simply added thereto as an auxiliary unit.

Utilization of circulating fluidized bed combustors for compressed air energy storage application

Abstract: A thermal energy peaking/intermediate power plant is disclosed having an atmospheric Fluidized Bed Combustor (FBC) for heating compressed air which is input to a turbine. Low-grade fuels such as coal may be combusted in the FBC, eliminating the need for additional combustors requiring premium fuels.

Optimal Set-Point Scheduling in a Boiler-Turbine System

Abstract: A 32nd order boiler-turbine model is developed to solve the optimal set-point scheduling problem for main and hot reheat steam conditions in a 235 MW gas fired electric generating plant. The model has 7 states in the process and 25 in the control system. The optimization strategy uses control vector parameterization in which the boiler controller set-point function generators are modified to produce suboptimum signals. The performance index consists of the total energy input to the system from the fuel and boiler feedpump. Constraints in the process variables are monitored by critical alarm limits, and hoop stresses in the heat exchanger tubes are estimated as well. The optimization problem is solved for steady state and dynamic conditions in the 75 to 235 MW load range. Savings in fuel between 0.7 to 4.0% are predicted by computer simulations in the normal operating load range of the unit. Preliminary plant tests indicate these estimated savings may be realistic. The boiler-turbine model and optimization strategy illustrate the potential use of mathematical models for power plants.

Solar photovoltaic and wind power in Greece

Abstract: The high energy cost for power supply to the Greek islands, as well as the favourable solar and wind conditions, led to the utilisation of these local energy sources for power generation. On the island of Kythnos, the first wind park of a capacity of 100 kW was installed as well as a 100 kWp solar photovoltaic plant with storage facility. Both plants are grid-connected for parallel operation with the existing diesel power station. Also, a stand-alone 50 kWp solar photovoltaic plant was installed in Aghia Roumeli, Crete, to supply the community. The experience gained from the design, installation and operation of the above projects led to the implementation of some demonstration projects, and to a five-year programme in solar and wind energy for power generation. Existing data and results from the islands favour a large-scale wind usage for oil saving. Small stand-alone PV plants for small systems are cost-effective. Hybrid solar and wind power systems for small islands are realisable.

Combined cycle power plant capable of controlling water level in boiler drum of power plant

Abstract: A combined cycle power plant capable of controlling a water level of a boiler drum of the power plant generally comprises a gas turbine system, a system turbine system, and a waste heat recovery system which are thermally linked with a feed water supply line and a steam supply line. The waste heat recovery system includes a boiler which is provided with a drum containing a feed water. The power plant further comprises a drum water level control system for stably maintaining the water level by selectively carrying out respective controlling modes in accordance with operation conditions such as an ordinary operation time, an operation stop time and a loss of fire of the gas turbine system by for example processing control signals in utilization of a change-over switch.

Resource assessment methods, siting, and performance evaluation

Abstract: The availability and monitoring of wind resource are discussed. Wind availability for wind turbine energy production is also of interest. (BCS)

Optimum operation of cogeneration plants with energy purchase facilities

Abstract: The paper presents an optimisation scheme for the economic dispatch of electric and steam demands to a cogeneration plant with a tieline and auxiliary boiler facilities. The primary objective of the optimisation scheme is to share both the electric and thermal load demands among the in-plant generating units and the energy purchase facilities to minimise the total energy cost. Depending on the cost parameters, optimum cogeneration can result in selling electricity during utility peak demand hours while purchasing electricity during the local peaks of either electricity and/or steam to reduce the overall cost of the unit product. The optimisation scheme is based on generalized network programming (GNP) which can often solve problems with significantly more variables and constraints that can not be easily solved by other optimisation techniques. This scheme is capable of handling the nonlinear cost functions and the dependent relations between the electric power and steam generation for the cogeneration unit. It is possible to represent the price of selling electricity as well as the cost evaluation of satisfying each steam and electric demand. Also, the proposed scheme has the capability to handle multiple objectives which is beneficial for the system operator.

Power generation cassette type power plant for marine electric propulsion and a controller thereof

Abstract: A power generation cassette type power plant for marine electric propulsion includes a multiplicity of power generation units each being formed as a power generation cassette including a power generator, a prime mover, for example an internal combustion engine for driving the power generator and a support structure for supporting the power generator and the engine internally. The support structure is formed in the same shape as that of a container for transporting cargo. When the power generators of the multiplicity of power generation units are operated in parallel to each other to supply electric power to a load, controllers serve to share the load to the generators properly.

The Electrical Aspects of Cogeneration System Design

Abstract: Cogeneration and the reasons that it is a viable industry today are discussed. Both bottoming and topping cycles may be employed for cogeneration; however, the topping cycle is the major focus of current cogeneration projects due to its applicability in large cogeneration power plants. The effect and reasons for the Public Utility Regulatory Policies Act removal of many of the disincentives of cogeneration are discussed. The relative efficiencies of conventional and combined-cycle cogeneration power plants are compared in a typical example of a large cogeneration power plant currently under construction. Many considerations face the electrical engineer in the design of a cogeneration power plant. Many applications will be found in industrial plants and will utilize industrial thinking within the plant; however, many decisions will be influenced by conventional electric utility thinking, due to the interface with the electric utility in the switchyard. Basic discussion of the considerations required of the electrical engineer, including electrical system arrangement, integration of the new generation into the plant electrical system, short-circuit matters, one-line diagrams, generator characteristics, excitation systems, step-up transformer ratings and characteristics, auxiliary transformers (station service), distribution systems, and system grounding, is given for preliminary guidance in design.

Device for exploiting the wave energy of surface water and a wave power station which contains at least one such device

Abstract: The device described contains at least one swinging lever (4) provided with a floating body (5) and articulated so as to be able to swing in the vertical plane on a main body (3) anchored in the water and, if desired, floating. Between each swinging lever (4) and the main body (3) is a piston/cylinder arrangement (6) to supply a pressure medium preferably directly into a pressure accumulator. The compressed pressure medium is decompressed in a turbine or in a hydraulic engine and the drive shaft of said turbine or engine is connected to a generator to produce electricity. It is proposed that at least on each floating body (5) at least one additional flow energy converter (7) is provided by which also the inherent flow energy of the water located in the wave passage is constantly extracted. Preferably several such devices can be linked with an on-shore power station by means of power and control cables, and economically and reliably operating wave power stations can thus be set up.

On the Application of Functional Analysis to the Optimization of the Production of Hydroelectric Power

Abstract: This paper presents a new approach the authors have used for solving the optimal long-term problem of a hydro power system for maximum expected benefits (benefits from energy generated by a hydro power system over the planning period plus the expected future returns from water left in storage at the end of that period). The problem is formulated as a minimum norm problem in the framework of functional analytic optimization technique. The proposed method takes into account the stochasticity of the water inflows, we assume that their probability properties are pre-estimated from past history. Numerical results are presented for a real system in operation consisting of three rivers; each river has two series reservoirs. The computing time using this approach is very small compared to that of other approaches.

Performance of the Integrated Gas and Steam Cycle (IGSC) for Reheat Gas Turbines

Abstract: In 1978, the Japanese government started a national project for energy conservation called the Moonlight Project. The Engineering Research Association for Advanced Gas Turbines was selected to research and develop an advanced gas turbine for this project. The development stages were planned as follows: first, the development of a reheat gas turbine for a pilot plant (AGTJ-100A), and second, a prototype plant (AGTJ-100B). The AGTJ-100A has been undergoing performance tests since 1984 at the Sodegaura Power Station of the Tokyo Electric Power Co., Inc. (TEPCO). The inlet gas temperature of the high-pressure turbine (HPT) of the AGTJ-100A is 1573 K, while that of the AGTJ-100B is 100 K higher. Therefore, various advanced technologies have to be applied to the AGJT-100B HPT. Ceramic coating on the HPT blades is the most desirable of these technologies. In this paper, the present level of development, and future R and D plans for ceramic coating, are taken into consideration. Steam blade cooling is applied for the IGSC.

Approximate Analyses of Feed and District Heating Cycles for Steam Combined Heat and Power Plant

Abstract: An assumption for turbine expansion lines originally made by Salisbury and Haywood (that the difference between local steam enthalpy and the enthalpy of saturated water at the same pressure is constant throughout the expansion) is used in approximate analyses of steam combined heat and power plant. Thermal efficiencies and energy utilization factors are derived for a number of cycles with steam extraction for feed heating and for district heating. Calculations of these two parameters are presented for relatively low pressure cycles.

A Guide to Small Wind Energy Conversion Systems

Abstract: Editors The British Wind Energy Association Preface Introduction 1. Wind characteristics 2. Choosing a machine 3. Very small machines 4. Regulations and institutional support 5. Buying and financing a machine 6. Installing and operating a system 7. Wind power for pumping water 8. Case studies Appendices.

Optimal unit selection in a combined heat and power station

Abstract: The immediate strategic problem of power station operation concerns the adjustment of the continuous operating variables to meet the energy demands at minimum cost. Superimposed upon this is the background task of identifying that selection of equipment which can reduce this cost even further. The paper describes a dual system which addresses both of these problems and which is operational at ICI's Wilton power station on Teesside. Some difficulties experienced with equipment selection are discussed together with the ways that they have been overcome in practice.

Two Years of Performance Data for the World's Largest Photovoltaic Power Plant

Abstract: The Carrisa Plains Photovoltaic Power Plant is the largest photovoltaic central station power plant in the world. The plant, interconnected to Pacific Gas and Electric Company's (PGandE's) transmission network, is owned and operated by ARCO Solar, Inc. This paper summarizes the plant's performance from January, 1984 to October, 1985. Performance is analyzed in terms of energy output, capacity factors, and match to PGandE's system load. The plant has been a reliable energy producer, has had high capacity factors during peak hours in the summer months, and has proven to be a good match to PGandE's peak system load.

Correlating compressor and turbine costs with thermodynamic properties for CAES power plants

Abstract: Compressed air energy storage (CAES) is a technology that converts excess base load energy into stored pneumatic energy by means of a compressor for a later release through a turbine as premium peaking power. The CAES system consists of a modified gas turbine combined with an underground storage reservoir. Since 1978, such a power plant has operated successfully in Huntorf, West Germany. Others are in construction throughout the world, the largest being constructed in Donbas, Soviet Union (1050 MW). CAES is more economic with respect to other energy storage facilities due to its relatively low installation cost, short construction time, and high reliability. However, since the number of CAES plants all over the world is still small, it is essential for plant planning and optimization to evaluate normative functions for the turbine and compressor cost. The components costs are evaluated from their thermodynamic and turbo-aerodynamic properties, enabling evaluation of the optimal plant parameters.

Power generating plant

Abstract: PURPOSE:To reduce the pressure loss so as to enhance the generating efficiency by directly connecting a screw-type two-phase flow expansion machine to a generator together with connecting a mixed-pressure steam turbine to the generator via a speed reducer CONSTITUTION:The steam in a boiler drum 7 is flowed into the high pressure part of a mixed-pressure steam turbine 2, while the hot water in the boiler drum 7 is directly flowed into a screw-type two-phase flow expansion machine 1 Thus, the power is generated to rotate a generator 33 On the other hand, the vapor-liquid multiphase flow flowed out of the screw-type two-phase flow expansion machine 1 is introduced into a vapor-liquid separator 4 so that it is separated into steam and hot water, and the steam thus obtained is flowed into the intermediate pressure pat of the mixed-pressure steam turbine 2 so that the steam generates the power in cooperation with the steam that flowed into the high pressure part Thus, the generator 33 is rotated via a speed reducer 3 The steam discharged from the mixed-pressure steam turbine 2 flows into a condenser 5 and is condensed by the cooling water Then the steam is introduced into a drain tank 11 by a pump 13

Performance of the Coolidge solar thermal electric power plant

Abstract: Energy performance and equipment evaluation results are presented for the grid-connected Coolidge solar thermal-electric power plant. Performance was determined for each of the major subsystems - line-focus collector array, thermal energy storage and 200 kW, organic Rankine cycle engine and generator. Day-long collector array efficiency was about 32, 26, and 9 percent in June, September, and December respectively. Energy conversion efficiency was about 20 percent; electrical parasitics reduced this by 12 percent. Operation and maintenance required about 90 h/mo, only 20 percent requiring special skills or training. Operating supplies and repair services cost about /6300 per year. Major equipment problem categories were fluid leakage and electric motor and electronic component failures. The presented operating data provide a basis for improved design and analysis.