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21.
俄气南供与天然气利用规划   总被引:2,自引:2,他引:0  
介绍了俄气南供的供气方案,讨论了天然气的市场调查和价格的确定等问题。  相似文献   
22.
A plane elastic-plastic solid body presenting kinematic hardening is used to simulate a pair of dampers at the base of a rigid structure and determine the energy dissipation under conditions of assigned, homogeneous cyclic loading. The well-known von Mises theory of plasticity is applied with the aim of obtaining analytical solutions to the problem. Such solutions are arrived at by first calculating the Odqvist parameter, which yields dimensionless relations that depend on the external loads and mechanical properties of the material. The results, in terms of dissipated energy, are given for the case of a sinusoidal process, represented with the help of dimensionless parameters useful for engineering applications.  相似文献   
23.
A. Rabl 《Energy Economics》1985,7(4):259-264
The decision to invest in energy conservation must be made in the face of uncertainty: future energy prices and the magnitude of energy savings are uncertain. Since once does not know the optimal investment level in advance, one will incur cost penalties due to misoptimization. To analyse the cost penalties it is convenient to focus on the ratio of the life cycle costs that one pays and the life cycle costs one would have paid with an optimal investment level. Two models are used to evaluate this ratio: a model for conductive heat flow through a layer of insulation, and an exponential curve fit to a large number of residential energy conservation cost data. Plotting the life cycle cost ratio versus the ration of actual and guessed energy expenditures shows the effect both of price uncertainties and of uncertainties in the performance of conservation measures. The graph can also be used to evaluate the cost to society due to the mismatch between individual and social perspectives. The curve turns out to have a broad optimum, and penalties due to misoptimization are fairly small in most cases. With these models one can also calculate the long-term price elasticity of energy demand for rational consumers. It turns out to be -0.5 in the insulation model and -1.0 in the exponential model.  相似文献   
24.
Conventional drying, dehumidification drying, and combined conventional-dehumidification drying of wood were experimentally studied in this article. The results showed that the energy consumption in the dehumidification drying is the least but its drying time is the longest. The energy consumption in the combined drying is more than that in the dehumidification drying but less than that in the conventional drying, and the drying time is half of that in the dehumidification drying. The advantages of the combined conventional and dehumidification drying are discussed from the experiments results.  相似文献   
25.
The thermal behaviour of a packed bed storage system charged with hot air is modelled using two partial differential equations representing the energy conservation in the air and solid phases constituting the bed. These two equations are coupled through the heat exchange process between the two phases. A fully implicit numerical scheme based on forward, upwind and central differencing for the time, first and second space derivatives, respectively, is used to solve the modelling equations. Marching technique is used for the air equation and a tri-diagonal matrix solver is employed to solve the solid equation. The solution yields the thermal structure of the bed, namely the air and solid temperature distribution inside the bed at any particular time, and the variation of total energy stored in the bed with time. The effect of bed length, solid diameter and void fraction on the thermal characteristics of the packed bed is studied. Further, the performance of the bed under variable inlet air temperature and mass flow rate is investigated.  相似文献   
26.
Electric power systems are expanding in size and complexity, and the requirement for the energy management system (EMS) is becoming more important. In this computer control system, a single control computer is used mainly as the primary computer and its software is very complicated because of its hugh number of small, quick tasks to obtain high response speed. Therefore, much effort is needed to develop and modify the programs, and the responsiveness of this centralized architecture varies greatly when many faults occur in the power system. This paper describes a new distributed architecture for the EMS. Distributed processors execute the functions cooperatively with periodic access to the common bulletin board database in which information about the power system exist. This architecture facilitates the software development and maintenance, and it also enhances the performance by the parallel processing of the distributed functions.  相似文献   
27.
Utility conservation programmes are designed to benefit both participants and non-participants. This article outlines the issues involved in designing conservation programmes for utilities and determining the appropriate amount of incentives that can be provided to participants without harming non-participants. More importantly, the article discusses the issue of access to the programmes by utility customers. It concludes that it is the existing restrictions to participation, and not the level of compensation, that are of greatest concern to non-participants. A number of utility programmes designed to eliminate the problem of non-participation are reviewed.  相似文献   
28.
This paper reports on statistics concerning production and consumption of packaging (as a whole or per capita) in Europe, in the USA, in Japan and in the world. Data have been provided by National Trade Associations and by consultants specialized in packaging and in economics. It is estimated that in 1986 the global consumption of packaging reached 150 millions of tonnes valued at 1200 billions of French francs. Consumption could reach 247 million tonnes by the year 2000. Paper and board have the highest consumption rate, but plastics have the highest rate of growth. Nevertheless, consumption per capita in the industrialized countries will be more than 10 times the consumption in underdeveloped countries. The packaging industries take fourth place in the USA, sixth in Western Germany and twelfth in France. In Europe, as in the world, paper and board is the material most used (40%), with glass (a high density material) taking second place and plastics third, i.e. if we consider the quantity of materials and not their value. Some differences appear between the various countries, but the figures for USA and Japan lead to similar conclusions. The survey shows clearly that the USA as compared with Europe has twice the consumption of packaging materials per capita and this difference is even greater compared with the rest of the world.  相似文献   
29.
It is shown that, when the mean productivity of some factors, such as energy or materials, is upperly bounded (a condition usually arising in energy production or in the process industries where energy takes part in physico-chemical processes), the production function may not be convex and, under some further conditions, is concave. Consequences of this model on the economics of energy savings are examined, and it is shown that energy savings may be considered at three levels: in the short run, by action on labour factors: in the medium run, by investment and action on labour factors; in the long run, by technological innovation, investment in new technologies and action on labour factors. Empirical findings along these lines are thus confirmed.  相似文献   
30.
The author examines the transport energy consumption of developing countries and compares it with that of developed countries. These figures are found to suggest considerable scope for transport energy savings. Given the need for improved energy efficiency, the author moves on to consider transport in the context of the wider economy. Four broad policy approaches which can affect transport energy consumption are identified — information and training programmes, subsidies; pricing and tax policies; and administrative regulations. The author's primary conclusion is that the energy price changes of the last decade do not hold revolutionary implications for the transport sector. There remains, however, a need to improve efficiency in this sector.  相似文献   
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