摘要:

AbstractA solution for the simulation of solar-thermal installations is presented, allowing not only to Investigate the effect of construction parameters of solar-installations on the energy output (like collector area, storage volume, and so on) but also provides a means for quantifying the influence of the control parameters of the solar systems. The simulation may be controlled interactively and the progress of simulation can be visualized or can be recorded for detailed offline evaluations. Emphasis is on the special problems and advantages when such a complex system is modelled within the limits of a general purpose minicomputer system.

ISSN:0228-6203    

DOI:10.1080/02286203.1981.11759735

出版商:Taylor&Francis    

年代:1981

数据来源: Taylor

摘要:

AbstractA mathematical model to simulate the dynamical behaviour of a drum-boiler turbine group is developed.The particular flexibility in its application is the most relevant characteristic of the model. In fact it is possible to simulate the dynamic behaviour of any drum- boiler and high-intermediate low pressure turbine by decomposing the general plant into subsystems connected with standard interfaces.The dynamic behaviour of each of these blocks is described in mathematical terms by considering them as open lumped parameter systems.Governing laws of fluid dynamics, of heat transfer and equations of state are written taking into account the changes in characteristics of fluid flow versus the two state variables, density and pressure,by linearized equations, around steady state operating conditions. The results of the simulation in open loop of dynamic behaviour of a 170 MW plant are presented too.

ISSN:0228-6203    

DOI:10.1080/02286203.1981.11759736

出版商:Taylor&Francis    

年代:1981

数据来源: Taylor

摘要:

SummaryThe concept is discussed of cooling a power cable by the natural convective flow of a coolant in the conductor duct. The following quantities are determined at a given distance from the conductor duct entrance; gas/liquid content (void fraction), heat-transfer co-efficient, temperature, flow quality and pressure. For a given reservoir head and cable loading (i.e. heat input) the permissible length of cooled cable is determined such that certain constraints are obeyed.Two coolants are considered, water and Freon-12. Water is held at a pressure of about 10’2 Bar in the reservoir which provides a low inlet temperature and a suitable phase-change temperature in the duct, i.e. one with a suitable margin below the cable operating temperature. Over part of the duct length, heat is absorbed by the fluid as sensible heat and over the remainder as latent heat in the two-phase flow with no temperature rise. Freon-12 is pressurised to about 15 atmospheres and similar methods are used for the design calculation as for water. The possibility of a“dry-out”occurring 1s examined and is seen to be a design constraint for the Freon-12 system.

ISSN:0228-6203    

DOI:10.1080/02286203.1981.11759737

出版商:Taylor&Francis    

年代:1981

数据来源: Taylor

摘要:

AbstractThe electric strength of high-voltage insulation systems depends on the level and the duration of stress. Systematic investigations have been car-ried out from the physical as well as from the statistical point of view using stress-strength models for testing the dielectric strength and the validity of statistic models of distribution for the long-term endurance.

ISSN:0228-6203    

DOI:10.1080/02286203.1981.11759738

出版商:Taylor&Francis    

年代:1981

数据来源: Taylor

摘要:

AbstractThis paper describes a mathematical model of a multiphase transmission system for simulating the surge, temporary and steady state period conditions associated with system energisation and isolation. It takes Into account source network, circuit breaker pole scatter, the mutual coupling between phases and circuits, and the non-11near character-istics of 3-phase transformers. A selection of results are presented and the continuing work on transformer representation is discussed.

ISSN:0228-6203    

DOI:10.1080/02286203.1981.11759739

出版商:Taylor&Francis    

年代:1981

数据来源: Taylor

摘要:

AbstractPublic demand for more efficient electrical energy production has necessitated attempts to improve the power loss performance of electrical systems, including such components as overhead transmission conductors. The most popular conductor for long lines is bare aluminum conductor steel reinforced, the models for which must include non-linear components to account for the saturation effects in the steel core. The current-carrying capacity of such lines is primarily a function of temperature. Hence any realistic model must also include not only internal heating effects due to ohmic losses but also emissivity and adsorption factors to account for environmental effects. An economic model must include, in addition to the considerations above, factors for capitalization, taxation, and depreciation as well as operational expenses. This paper reports on a method to accomplish the above in order to effect comparisons between different types of conductor. Such comparisons will not only assist in the selection of conductors for particular lines, but also for choices of conductors on inventory.A sample comparison is made showing the relative effects of several different types of conductor using actual cost data from a utility.

ISSN:0228-6203    

DOI:10.1080/02286203.1981.11759740

出版商:Taylor&Francis    

年代:1981

数据来源: Taylor

摘要:

AbstractThe ever-increasing need for detailed and accurate reactor-physics simulations, and the magnitude of the computer effort required to satisfy this need, together are a powerful Incentive to a continuing search for Improvements in the economy of the numerical analysis and of the usage of computer resources.This paper reviews some of the work done In the last few years In the development of efficient methods for CANDU neutronics. The emphasis Is on presenting a few of the techniques Implemented, and Illustrating the scope of the simulations.

ISSN:0228-6203    

DOI:10.1080/02286203.1981.11759741

出版商:Taylor&Francis    

年代:1981

数据来源: Taylor

摘要:

AbstractAn evaluation of the supply of natural gas and Its by-products in relation to foreseeable requirements of both the Canadian domestic and export markets involves not only the use of large data oriented computer models but also a high degree of qualitative analysis to insure the validity of the forecast. Computer Research Associates Ltd. (CRA) with the financial assistance of the Department of Industry, Trade and Commerce of the Canadian Government, designed and constructed the GEMM (acronym for Gas Energy Management Model) computer model which evaluates a nation’s total gas supply availability and its relationship to a set of market scenarios. The description of the GEMM model was presented at the Proceedings of the International Symposium, Simulation, Modelling and Decision in Energy Systems held in Montreal Canada, June of 1978 [1].In July of 1979, International Energy Consultants (a joint venture of which CRA was the major partner) was commissioned by The Alberta Gas TrunkLine Company Limited and TransCanada Pipelines Ltd. to present a composite evaluation of Canada’s gas supply to the National Energy Board. This paper is intended to provide an overview of some of the technically innovative computer procedures and data requirements which were necessary to obtain an accurate reflection of the Canadian supply/requirements interaction.

ISSN:0228-6203    

DOI:10.1080/02286203.1981.11759742

出版商:Taylor&Francis    

年代:1981

数据来源: Taylor

ISSN:0228-6203    

DOI:10.1080/02286203.1981.11759743

出版商:Taylor&Francis    

年代:1981

数据来源: Taylor

摘要:

AbstractA detailed analyaia of the dynamio behaviour of a 4-input counter flow heat exohanger has been per formed by aolving the ayatem partial differential equations with finite differenoe techniques. The model appears in good accordance with praatioe. Model identification with original techniques le ada to reduced order linear models. Results with reepeat to identification goodneaa and to various system working conditions are evaluated. Experi_ menta performed with a proposed identification al gorithm from step response are alao presented.

ISSN:0228-6203    

DOI:10.1080/02286203.1981.11759744

出版商:Taylor&Francis    

年代:1981

数据来源: Taylor