摘要:

AbstractAn explicit expression for the periodic variation of thermal flux through a multilayered insulated hollow wall/roof, whose one face is exposed to solar radiation and ambient air and the other is in contact with room air at constant temperature, has been derived. to obtain optimum placement of insulation and airgap, numerical calculations for the heat flux through a multilayered insulated hollow wall/roof have been made for a typical hot day (26 May 1978) in Delhi. It is seen that for a given total thickness of concrete, best load levelling is achieved when the thickness of the outer layer is as small as possible. the effect of a water film on heat flux into the buidling has also been discussed.

ISSN:0363-907X    

DOI:10.1002/er.4440050102

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

年代:1981

数据来源: WILEY

摘要:

AbstractIn this paper we have investigated the reduction of heat flux through a roof using a water film with air gap in the structure. It is seen that by using this combination, the heat flux coming through the roof can be reduced by 75 per cent. the reduction in heat flux is found to increase with decreasing humidity.

ISSN:0363-907X    

DOI:10.1002/er.4440050103

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

年代:1981

数据来源: WILEY

摘要:

AbstractTwo‐dimensional flow analysis of an incompressible, viscous fluid past an infinite porous vertical plate, in the presence of constant heat flux, has been presented. the effects of suction, free convection currents and free‐stream oscillations have been considered and approximate solutions to the coupled non‐linear equations have been derived in case of small amplitude oscillations. the solutions are derived for the mean velocity, the mean plate temperature, the mean skin‐friction, the transient velocity, the transient temperature, the amplitude and phase of the skin‐friction, and the first and second harmonics of the plate temperature. Velocity and temperature fields have been shown graphically whereas the numerical values of the other physical quantities are given in tabular form. During the course of discussion, the effects of γ (suction parameter), G(the Grashof number), E (Eckert number), P (Prandtl number and ω (frequency) have bee

ISSN:0363-907X    

DOI:10.1002/er.4440050104

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

年代:1981

数据来源: WILEY

摘要:

AbstractThe principle of the absorption process is described and its versatility demonstrated. A wide range of applications, from household refrigerators to topping processes in power plants, are surveyed in an historical perspective. the production of mechanical energy and open systems are also included. Modern developments are reviewed, special attention being given to the aspets of thermal energy storage.

ISSN:0363-907X    

DOI:10.1002/er.4440050105

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

年代:1981

数据来源: WILEY

摘要:

AbstractPrime movers and boilers have traditionally been optimized independently to convert fuel to power and heat, respectively. the design of devices to optimize the simultaneous production of heat and power has been neglected. This paper considers the optimization in this mode of diesel engines and concludes that simple modifications of design could increase the heat recoverable in the exhaust by the equivalent of 10 per cent of the fuel input. In monetary terms this is equivalent to about a 4 per cent increase in brake efficiency, recent improvements in brake efficiency of this magnitude have taken ten or fifteen years of continuous research and development. the changes now proposed would increase thermal loading and some development might be necessary.

ISSN:0363-907X    

DOI:10.1002/er.4440050106

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

年代:1981

数据来源: WILEY

摘要:

AbstractSome geometrical concentration characteristics of a solar concentrator system employing a Fresnel reflector concentrator and a compound parabolic concentrator in tandem are discussed.

ISSN:0363-907X    

DOI:10.1002/er.4440050107

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

年代:1981

数据来源: WILEY

摘要:

AbstractA discrepancy is reported whereby laboratory measurements of the COPhof air‐to‐water heat pumps yield performace data which are significantly inferior to seasonal values as measured in the field. A mechanism is proposed to account for this and example calculations show that improvements of up to 20 per cent can be expected over normal laboratory estima

ISSN:0363-907X    

DOI:10.1002/er.4440050108

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

年代:1981

数据来源: WILEY

摘要:

AbstractThis note presents a simple transient model for predicting the thermal performance of some novel solar water heaters which combine both collection and storage of solar energy. These heaters consist of either (i) an insulated rectangular tank whose top surface is blackened and suitably glazed, or (ii) an insulated open shallow tank with black bottom/inner sides and a top glass cover (shallow solar pond). the heaters are adequately covered with an insulation during the night to reduce the heat losses. the proposed model is based on different characteristic equations during sunshine and off‐sunshine hours. It is seen that the model predicts the water temperature in close agreement with the experimental observations and earlier theoretical investigation

ISSN:0363-907X    

DOI:10.1002/er.4440050109

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

年代:1981

数据来源: WILEY

ISSN:0363-907X    

DOI:10.1002/er.4440050110

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

年代:1981

数据来源: WILEY

ISSN:0363-907X    

DOI:10.1002/er.4440050101

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

年代:1981

数据来源: WILEY