摘要:

Components for passive solar energy utilization can be generally treated as consisting of translucent insulation, radiation control, absorber and storage. Although even in central Europe the total radiation upon a building amounts to more than the heating energy needed during the winter season, closer inspection shows that the available storage capacity is not sufficient to cover the entire load by radiation: auxiliary heat is always required. On the other hand, overheating must be avoided by means of control devices. Components in use at present are: windows, conservatories and, to a lesser extent, trombe walls. Newer developments are based on materials exhibiting high light transmission and good heat insulation properties. Such materials can be used as outside insulation of old building stock and offer prospects for significant energy savings.

ISSN:0142-5919    

DOI:10.1080/01425918508914401

出版商:Taylor & Francis Group    

年代:1985

数据来源: Taylor

摘要:

Testing a thermal storage device accurately for its characteristic parameters requires a large amount of time. Of the six or so key parameters which characterise a thermal store it is the determination of the overall fluid to storage material heat transfer coefficient, UA, and the “ degree of stratification” which consumes the most time, e.g. six different flow rate tests about ambient temperature. Therefore, shortcut methods based on theory are desirable to reduce the experimental effort. Presented herein is the idea of establishing the upper and lower limits on UA by assuming a perfectly mixed and perfectly stratified response respectively. The latter requires the use of a Schumann plot of the exit temperature at one fill period. Such a subset of the general Schumann plots is called a “ Locus Curve” The derivation of the locus curve is given together with an indication of how it is used for the identification of UA from a step response test.

ISSN:0142-5919    

DOI:10.1080/01425918508914402

出版商:Taylor & Francis Group    

年代:1985

数据来源: Taylor

摘要:

Two methods are described for identifying the key overall fluid to storage material heat transfer product, UA, and the degree of stratification, NT, for use in the analysis of storage test data

ISSN:0142-5919    

DOI:10.1080/01425918508914403

出版商:Taylor & Francis Group    

年代:1985

数据来源: Taylor

摘要:

The collector most frequently used in solar plants is of the flat-plate single cover type; however its field of use is limited owing to the low temperatures reached with this type of installation. Collectors with a greater number of covers produce higher temperatures, thus broadening their field of use

ISSN:0142-5919    

DOI:10.1080/01425918508914404

出版商:Taylor & Francis Group    

年代:1985

数据来源: Taylor

摘要:

This investigation is a theoretical and experimental study of a recuperative type solar water heater where water is allowed to pass through the two upper transparent covers in channel flow before flowing through the tubes of the collector. The water in the channel will be first heated by solar insolation absorbed in the fluid layer and by the upper heat losses from the absorber plate before being heated in the main collector tubes. The performance of this collector was analytically studied under various environmental and operating conditions, in addition, an experimental apparatus was built, commissioned and tested. The analytical model, confirmed by experimental results, indicated that the proposed design was superior to the conventional solar water heater within a certain range of mass flow rates and environmental conditions.

ISSN:0142-5919    

DOI:10.1080/01425918508914405

出版商:Taylor & Francis Group    

年代:1985

数据来源: Taylor