摘要:

Commonly accepted power curves of wind turbines are essential for an effective comparison and for a reliable energy output prediction. This presumes a detailed knowledge of the possible error and uncertainty sources which can affect power curve measurements. The study [1] concentrates mostly on physical effects which cannot be evaluated on a standardized way and therefore have to be treated with care. It does not claim for completeness but it points out some sources of errors which appear to be important.

ISSN:0142-5919    

DOI:10.1080/01425919208909726

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

In a research project, supported by the EEC, possible applications of PV power in near production passenger cars were examined. Solar ventilation of parked cars lowers the heat build up in the sun by more than 50%. Solar assisted a.c. systems can be designed for lower power input at improved performance. Supplying the electrical power for the vehicle consumers from a solar panel instead of the vehicles alternator lead to fuel economy improvements of 3 to 9%.

ISSN:0142-5919    

DOI:10.1080/01425919208909727

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

Conversion efficiencies of 11.5-12% have been obtained for solar cells with an active layer epitaxially grown on upgraded metallurgical grade silicon substrates made by industry. An epilayer thickness of 30 μm was shown to be sufficient if the substrate doping is much larger than the epilayer doping. Spectral response measurements, fitted to simple models, showed that:

ISSN:0142-5919    

DOI:10.1080/01425919208909728

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

A novel, extended-surface, flat-plate solar collector has been investigated and tested. Comparative test results with an identical tubeless, flat-plate solar collector (without surface extension) indicate that the surface extension by indentation improves the collector efficiency almost in the same proportion as the absorber area is increased by extension for the same heat flux.

ISSN:0142-5919    

DOI:10.1080/01425919208909729

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

The thermal performance of a solar heat collector in which the air path is reversed to flow beneath the absorber plate after passing over it was studied. This type of system is referred to by the authors as the Reversed-Pass Air Flow Collector. Under the same operating conditions (gas flow rate & tilt angle), the rise in air temperature, ΔT, was found to be 10 to 40% higher than that obtained with single-pass air flow (without reversing) system depending upon the prevailing weather conditions. The local heat transfer coefficient from the top surface of the absorber plate was calculated for both types of flow systems and was found to be almost equal. The increased rise in temperature, ΔT, with the reversed-pass air flow system led to an increase in the thermal efficiency of the solar collector.

ISSN:0142-5919    

DOI:10.1080/01425919208909730

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

A theoretical and experimental study was carried out to investigate the effect of adding a passive condenser on the performance of the single slope, basin type solar still. A theoretical model based on Dunkle [1] mass transfer (evaporation) rate was developed. The model assumes that the transfer of water vapour from the still to the condenser is due to one or more of the following mass transfer modes; (i) diffusion, (ii) purging and (iii) natural circulation. The theoretical results indicate that diffusion contribution is relatively small. The contribution through purging represents the fraction [V(cond)/(V(cond) + V(s))] of the still yield, while it represents 75% of the still yield through natural circulation. An experimental study that simulates the purging mass transfer mode was investigated. The experimental results show good agreement with the theoretical predictions and an increase of 45% in solar still efficiency was obtained.

ISSN:0142-5919    

DOI:10.1080/01425919208909731

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

A new chart of simulation method, named J-chart, has been developed for predicting the long-term average performance of solar drying systems. The result of many simulations allows to develop a simple graphical method, represented by 3 charts and their polynomial correlations, to obtain a general design procedure for a partially solar heated dryer. The first one is the drying time, the second one is the fraction of heating load supplied by solar energy and the third one is the fraction of economized energy. These charts and the correlations are used in establishing relationships between the collector area and the weight of the produce to be dried or the dried produce. This method is developed by using the monthly average values for a moderate climate (Perpignan, Φ = 42.41°) and with the assumption that the dryer is used daily over a year and the duration of drying operation is assumed to be less than 24 hours.

ISSN:0142-5919    

DOI:10.1080/01425919208909732

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

The Japanese R & D Programme on solar energy under the Sunshine Project of MITI will be described. The programme is aiming at practical use of solar energy in the 21st century.

ISSN:0142-5919    

DOI:10.1080/01425919208909733

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

Transparent or translucent insulation materials (TIM) represent a new class of materials with a high potential for increasing the efficiency of solar thermal systems. A large number of materials and material combinations has been subjected to theoretical and experimental investigation. An overview of generic types, characterisation methods, real existing materials available on the market, and the future potential of transparently insulated systems will be given as well as first results of applications in active and passive systems.

ISSN:0142-5919    

DOI:10.1080/01425919208909734

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor