ISSN:0363-907X    

DOI:10.1002/er.4440090202

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

年代:1985

数据来源: WILEY

摘要:

AbstractA new concept is introduced of using a greenhouse for enhancing the biogas yield from a conventional biogas system in the winter months. If a conventional biogas system is glazed, the trapped solar energy can be used to raise the temperature of the slurry which normally goes low enough to reduce the gas yield appreciably. Numerical calculations have been performed corresponding to the meteorological data on a typical winter day, i.e. 19 January 1981, at New Delhi (India). A comparative study of the performances of conventional and solar‐assisted biogas plants using the concept of a greenhouse indicates that the ambient temperature of the slurry can be raised from 18°C to about 37°C, the optimal temperature for anaerobic fermentat

ISSN:0363-907X    

DOI:10.1002/er.4440090203

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

年代:1985

数据来源: WILEY

摘要:

AbstractSteady laminar binary mixed convection flow along a vertical circular cone under the combined buoyancy effects of thermal and species diffusion is studied analytically. The analysis is confined to mass diffusion processes with low concentration levels. In the analysis the surface of the cone is assumed to be at a uniform temperature and uniform concentration. Numerical results for the local Sherwood number, local Nusselt number and local friction factor are presented. Representative temperature, concentration and velocity profiles are also shown. The analysis covers the diffusion of common gases and vapours into air. Considerations are given to the situations where the buoyancy forces assist and oppose the forced convection flow for various possible combinations of the thermal and species diffusion processes.

ISSN:0363-907X    

DOI:10.1002/er.4440090204

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

年代:1985

数据来源: WILEY

摘要:

AbstractThe overall performance of a solar thermal electrical power generation system is governed by the performance of the energy collection system and the power conversion unit. Any system operating under given meteorological and solar radiation conditions has a unique energy collection temperature for which the electrical output of the system will be a maximum. An engineering analysis of the system was carried out to obtain general correlations which can be used for determining such an optimum temperature. Factual experience on the design and operation of a Rankine system, using flat plate collectors and the climatological data, was used to obtain numerical estimates for the net energy conversion capability of such systems operating in Kuwait.

ISSN:0363-907X    

DOI:10.1002/er.4440090205

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

年代:1985

数据来源: WILEY

摘要:

AbstractLaminar free convection around a long porous limiting cylindrical surface arising from the buoyancy forces created by temperature as well as by transpiration‐induced concentration gradients is investigated. All the fluid properties except for the temperature and concentration‐dependent body forces are assumed to be constant in the analysis. The dimensionless non‐linear coupled boundary‐layer equations embody the following parameters: (1)Pr, the Prandtl number, (2)Sc, the Schmidt number and (3)R, the ratio of the concentration to the thermal buoyancy forces. Numerical results for the local Nusselt number, the local wall shear stress and the local Sherwood number are displayed graphically for the transpiration‐induced convective diffusion of hydrogen, water vapour and naphthalene into an air‐saturated porous medium. The dimensionless thermal, concentration and momentum boundary layer thicknesses, along with the cumulative tangential mass flow rate are given in tabular form. The analysis covers a wide range of bl

ISSN:0363-907X    

DOI:10.1002/er.4440090206

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

年代:1985

数据来源: WILEY

摘要:

AbstractThe output parameters of different types of vacuum (VAFEC) and gas filled (GAFEC) fission electric cells (FECs) have been measured during their irradiation in the nuclear reactor of the Central Institute of Physics in Bucharest, Romania, at different thermal neutron flux (ϕnth) values in the 108…1012neutrons/cm2s range. These measurements allowed us to estimate to what degree the FEC output parameters depend on the ϕnthvariation and pointed out the differences in the operation of the VAFEC and GAFEC‐type devices. The main results for some of the tested FECs are pres

ISSN:0363-907X    

DOI:10.1002/er.4440090207

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

年代:1985

数据来源: WILEY

摘要:

AbstractOne of the applications of solar energy is the photo‐thermochemical production of fuel, particularly hydrogen. In this regard photo‐oxidations/reductions are important processes and may provide a route to harnessing solar energy.Liquid sulphur absorbs in the visible region (400–500 nm). The absorption of light in this region will produce excited sulphur and hence can take part in the photo‐oxidation/reduction process.The photo‐oxidation of liquid sulphur by Fe(III) salt (anhydrous ferric chloride) at 150 ± 5°C was studied in both the presence and absence of visible light. It was found that liquid sulphur was photo‐oxidized by Fe3+which itself was reduced to Fe2+. The overall rate constants for photo‐thermochemical and pure thermochemical reactions were found to be 5–3 × 10−6M−1s−1and 2–8 × 10−6M−1s−1, respectively. A mechanism for the photo‐

ISSN:0363-907X    

DOI:10.1002/er.4440090208

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

年代:1985

数据来源: WILEY

摘要:

AbstractThree social objectives figure prominently in the extraction of finite energy resources, namely income maximization, environmental quality, and inter‐generational concern. Owing to lack of complementarity, the pursuit of these objectives often results in conflicts. As a result, extraction strategies should be based on the determination of trade‐offs between the objectives. The paper deals with the formulation and illustration of a systems model to determine these trade‐offs. The recognition of such trade‐offs results in a greater conservation of the finite energy resource, and hence could act as an incentive for the development of alternative energy

ISSN:0363-907X    

DOI:10.1002/er.4440090209

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

年代:1985

数据来源: WILEY

摘要:

AbstractThe wider industrial impact of energy R&D programmes is generally misunderstood, with the result that their strategic importance is nowadays seriously underestimated.This paper indicates the important positive effects that energy R&D can have for more general aspects of industrial productivity and competitivity, and illustrates this using examples drawn from the European Community Energy R&D Programmes.

ISSN:0363-907X    

DOI:10.1002/er.4440090210

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

年代:1985

数据来源: WILEY

摘要:

AbstractAn auxiliary start‐up system is required in fluidized bed combustors in order to heat the bed to a temperature at which coal fed to the bed will ignite and burn without producing excessive smoke. Four methods are used by the U.K. National Coal Board, the one selected for a particular application being dependent on the type of solid fuel used and the type of appliance. To illustrate the nature of the design calculations associated with start‐up, the paper describes the principles of a mathematical model developed to determine the rating of burner required for the hot gas start‐up app

ISSN:0363-907X    

DOI:10.1002/er.4440090211

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

年代:1985

数据来源: WILEY