摘要:

AbstractThe price per unit generated electrical energy decreases with increasing size of the generator, which implies longer transmission line and hence larger transmission losses. Considering both these facts the optimum size of thermal power station for growing demand has been obtained by using life‐cycle costing analysis. The demand may be met by (1) a combination of base load and peak load generators (Sodha and Chandra, 1992) and (2) by a combination of base load generators only. The second option has been analysed in this paper. The dependence of investment ratio (the ratio of present worth of net income to the capital investment) on relevant parameters has been studied. It is seen that there exists a particular pattern (optimum combination) of base load generators. The effect of electricity price, coal price and escalation rates on the optimum configuration has also been investigated. The cost data from recent study in India have been use

ISSN:0363-907X    

DOI:10.1002/er.4440180302

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1994

数据来源: WILEY

摘要:

AbstractA comprehensive nonlinear programming model, MIMES, for the optimization of linked material and energy flow systems is presented. The model is generic, intended for systems that can be described by materials and energy balances but where the details of phase transitions and chemical reactions can be omitted. It fills a niche between energy systems engineering and process flowsheeting models. Issues suitable for analysis by the model range from energy conservation in industrial plants, specific industries or industrial subsectors to municipal waste management and fuels and materials life cycle analysis. MIMES is implemented on PC (386/486).The model is demonstrated for a paper production line in a paper mill. This example shows how the model can be used for joint analysis of energy and water conservation, substitution of energy carriers, and utilization of waste heat outside the system.

ISSN:0363-907X    

DOI:10.1002/er.4440180303

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1994

数据来源: WILEY

摘要:

AbstractA method for turbulent pipe flow measurements using velocities at two radial positions is presented. The method is insensitive to the Reynolds number and surface roughness; therefore, it is suitable for use in pipe systems subjected to slow variations in flow and pipe surface conditions. Applied to three independent data sources, the method shows significant improvement in average accuracy in comparison with a single‐point method and a log‐linear met

ISSN:0363-907X    

DOI:10.1002/er.4440180304

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1994

数据来源: WILEY

摘要:

AbstractIn most commercial buildings and industrial plants HVAC systems consume large amounts of energy, and usually offer the most significant potential for savings. Liquid conventional chillers play a very important role in providing these savings. Proper design, installation, and maintenance of these systems are therefore the key steps leading to improved efficiency which benefit both the customers and the utilities. To effectively materialize this concept two steps have been followed here.In the first section of this paper conventional chillers of different types have been modelled and simulated using a software (DOE2). The chillers are rated for a generic building and meteorological weather of San Diego. Performance parameters such as the part/full‐load efficiencies, the number of occurrences during peak hours and load frequencies are then calculated. These results gave typical performance values (curves) which can be used to compare screw, centrifugal, and reciprocating chillers among each other within a predefined scope.In the following section the field data of 39 conventional chillers and the manufacturers specifications of some of them are collected and analysed. This gave an overall view of their actual field performance and their deviation from the manufacturers' specifications.Comparison of the simulated and collected data also provided better vision of the expected performances versus the actual performances, and pinpointed some major drawbacks in the design and sizing methodology. The results also led to important conclusions regarding thestatus quoand the possibilities in the immediate future. Preferred chiller types and methods of providing the required cooling energy recommended by the simulation results are compared with the existing ways of providing energy in order to conform the eventual promises and quantify the room for efficienc

ISSN:0363-907X    

DOI:10.1002/er.4440180305

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1994

数据来源: WILEY

摘要:

AbstractThe aim of the paper is to create a new climatic model suitable for an energy balance analysis of the below‐grade part of a building in a country with diverse topography, Slovakia, serving as an example. Slovakia is the eastern part of the former Czechoslovakia with a population and area similar to that of Denmark. Constants in the final relations — the mean annual temperature on the ground susrfaceTo2, the mean annual temperature in 1 m and/or 2 m depthT12, the average year temperature amplitude on the surfaceAY, and the day of occurrence of the minimal temperatureto— were introduced on the basis of the statistical evaluation of the long‐term temperature measurements of the Hydreometeorological Institute on 49 sites in Slovakia. The discussion of recommended values is given together with information on air and underground water temperatures. Through statistical analysis it was possible to quantify dependence of theTo2,T12andAY, on elevation which was found to be the most important parameter for the climatic model of the country. The weighted average of the minimum daily temperatures from all the years recorded at 49 meteorological stations was determined as the day when minimum surface temperature occur in Slovakia. It was found to be in agreement with the results of long‐lasting measuring of air te

ISSN:0363-907X    

DOI:10.1002/er.4440180306

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1994

数据来源: WILEY

ISSN:0363-907X    

DOI:10.1002/er.4440180307

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1994

数据来源: WILEY

ISSN:0363-907X    

DOI:10.1002/er.4440180301

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1994

数据来源: WILEY