摘要:

Environmental issues have recently become a major driving force throughout the UK educational system. In parallel, interest has continued to grow in what was originally called “alternative technology”, as defined below. Other linked concepts, such as “appropriate technology” or “intermediate technology” are also discussed briefly.

ISSN:0143-0750    

DOI:10.1080/01430750.1996.9675219

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

In the present work, the performance of a stratified and well-mixed solar hot water system was examined under the Hungarian climatic conditions. The system consists of a solar flat plate collector with an effective area of four square metres coupled with a storage tank with a capacity of two hundred litres. An oriented simulation programme was developed for the system components. The heat flow inside the stratified tank was considered to be one dimensional and the temperatures were determined applying simple Euler integration. These temperatures were compared with the well-mixed one. The final results showed that the thermal stratification improved the performance of the system by 12% compared with the well-mixed case. As a result, higher values for the load temperatures were satisfied in day time in the case of stratified tank i.e. increased by about 8°C at noon compared with the well-mixed case.

ISSN:0143-0750    

DOI:10.1080/01430750.1996.9675220

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

Four solar collector models are presented for a solar heat engine designed to function either at its maximum possible efficiency or at its maximum possible output power in this paper. The operating temperatures of the solar collectors under these conditions are found. The results provides the basis for designing a real solar heat engine.

ISSN:0143-0750    

DOI:10.1080/01430750.1996.9675221

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

Measurement and analysis of outdoor illuminance have been reported for Hong Kong. Regression analysis of the measured data indicates that both global and diffuse illuminance can be correlated with solar altitude under different sky conditions. Cumulative frequency distributions of outdoor daylight availability suggest that in more than half of the working year, daylighting alone can provide adequate lighting level in the perimeter zones of most office buildings. Likely energy savings in electric lighting for a generic office building has also been estimated.

ISSN:0143-0750    

DOI:10.1080/01430750.1996.9675222

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

This paper describes improvements in the wind-scoop geometry and efficiency of a double-stack Savonius rotor, developed through a series of wind tunnel and field tests in East Africa. On an aerodynamic performance basis, the Savonius rotor cannot generally compete with other types of wind turbines. This is entirely due to its mode of operation. Unlike its counter-parts that operate by rotating around a horizontal axis, it rotates around a vertical axis. This has the unfortunate effect of lowering its efficiency, but it has several compensating factors. Its main advantages are that it has better starting torque performance with operating characteristics independent of the wind direction. In addition, it is simple in structure and the fabrication technology required is less sophisticated when compared to similar types of windmills. This makes it a suitable system for small scale applications in wind energy conversion; especially in remote rural regions in developing countries.

ISSN:0143-0750    

DOI:10.1080/01430750.1996.9675223

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

Many field studies on thermal comfort have been reported to show a discrepancy between the actual (observed) and predicted votes. A field study on thermal comfort in the capital city of Jakarta, Indonesia, has been demonstrating some agreement with other field studies and has shown that PMV and PPD predicts higher than the actual votes.

ISSN:0143-0750    

DOI:10.1080/01430750.1996.9675224

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

This communication presents an entropic analysis based on combined first and second laws of thermodynamics for a vapour liquid absorption (VLAB) cooling system. The model provides an insight understanding of entropy production mechanisms of various irreversible processes inherent in absorption systems and also gives an explicit explanation of actual COP degradation with respect to the ideal reversible Coefficient of Performance (COP) in terms of entropy generation associated with irreversible processes. Numerical results for water-LiBr absorption system and given cold production, source and sink temperatures are presented for different effectiveness of solution heat exchanger and the components/parameters which affect most the system performance are visualised. It is ascertained that the solution circuit components are most sensitive and the individual entropy productions are inter-dependent on each other as well as on the solution recirculation ratio and the effectiveness of the solution heat exchanger. Thermal coupling entropy production is dominant in COP degradation in the basic absorption cycle while other internal irreversibilities are dominant for the refined absorption cycle (with solution heat exchanger) for the actual COP degradation with respect to the Carnot COP.

ISSN:0143-0750    

DOI:10.1080/01430750.1996.9675225

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

ISSN:0143-0750    

DOI:10.1080/01430750.1996.9675226

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

ISSN:0143-0750    

DOI:10.1080/01430750.1996.9675227

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

ISSN:0143-0750    

DOI:10.1080/01430750.1996.9675218

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor