摘要:

AbstractA mathematical model for an integrated heat‐pump‐assisted dryer has been developed. The dryer has been modelled considering the heat transfer and simultaneous heat and mass transfer zones. The heat‐pump heat exchangers have been modelled by writing the enthalpy balance for differential lengths considering the various zones on the air and working‐fluid sides. The compressor has been described by the polytropic compression equation. The model has been used for simulating an existing system using R11 to study the effect of approach velocity of air to the evaporator and of the suction superheat on the specific energy consumption of the heat pump assiste

ISSN:0363-907X    

DOI:10.1002/er.4440140502

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

年代:1990

数据来源: WILEY

摘要:

AbstractThe performance of an experimental heat‐pump‐assisted dryer under operating conditions of some practical interest was studied. The system was operated using R11 and R12. The approach velocity of air to the evaporator and the superheat of the working fluid at the exit of the evaporator were identified as the critical parameters for optimization. The system was evaluated with respect to coefficient of performance(COP)and specific energy consumption (SEC). The(COP)A, and (SEC) values obtained using R11 were 3.5 and 3500 kJ/kg, respectively, and the corresponding values for R12 were 2.5 and 1800 kJ/kg. In spite of the lower(COP)A, for R12, the corresponding (SEC) values were better because the system could be operated without any additional electrical heating with

ISSN:0363-907X    

DOI:10.1002/er.4440140503

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

年代:1990

数据来源: WILEY

摘要:

AbstractThe last decade or so has seen major changes in the structure of the UK economy. There has been a continual decline in manufacturing, both relatively (not unique to the UK) as well as absolutely (unique to the UK of all the major industrialized economies), while the discovery and exploitation of oil in the North Sea has moved the UK from a position of total dependence on imported oil, through self sufficiency, to its becoming a significant net exporter. Such oil developments have occurred against the background of two major oil price increases, in 1973/74 and 1979/80, which have also had major implications not only for the UK but also for its trading partners.The accelerated decline of the traditional manufacturing industries, and the associated rise in unemployment, to many observers, is at least partly a result of the emergence of the UK as a major oil producer. The theoretical justification for such a viewpoint is identified.This paper is predominantly concerned with outlining the importance of oil and gas production to the UK economy. It also discusses the major theoretical models that have been developed to analyse both the short run and long run impact of oil on that economy. A quantitative assessment is made of the impact of oil on the UK economy, and of the role of the Government arising from such a discovery.

ISSN:0363-907X    

DOI:10.1002/er.4440140504

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

年代:1990

数据来源: WILEY

摘要:

AbstractIn this paper, a techno‐economic model has been developed for a solar still coupled with a flat‐plate collector through a heat‐exchanger. The model is based on the establishment of periodic steady‐state conditions. The economic criterion used in the model is based on the least cost of a unit mass of distilled water evaluated from the life‐cycle costing of the system. To evaluate the model, numerical calculations have been made corresponding to the climate of Delhi (India). It is concluded that the addition of a solar collector enhances the distillate yield; however, this is not always economical. This system therefore needs careful and economic syst

ISSN:0363-907X    

DOI:10.1002/er.4440140505

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

年代:1990

数据来源: WILEY

摘要:

AbstractAn alternative to the use of the traditional lithium‐bromide/water system for absorption cooling is discussed. An experimental study is presented on the use of salt mixtures of lithium‐bromide/zinc‐bromide and lithium‐bromide/lithium‐iodide as absorbents for water. It is shown that the higher solubilities of the ternary systems allows operation at higher absorber and generator temperatures without the risk of crystallization and with low enough evaporator temperatures for practical cooling app

ISSN:0363-907X    

DOI:10.1002/er.4440140506

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

年代:1990

数据来源: WILEY

摘要:

AbstractA thermal simulation method for estimating the ground losses from earth coupled structures has been described. The accuracy of the method has been evaluated by comparing the experimental results obtained for a sphere with the corresponding analytical results. The method has been used to determine the shape factor, which can be used to evaluate the heat loss to the ground for (i) slab‐on‐grade buildings, (ii) a sunken cylindrical structure, and (iii) sunken and buried parallelepiped structures for different ratios of their dimensi

ISSN:0363-907X    

DOI:10.1002/er.4440140507

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

年代:1990

数据来源: WILEY

摘要:

AbstractIn the paper, the rate of change of vorticity covariance in MHD turbulent flow of a dusty fluid is discussed. The results obtained show that the defining scalars α(r, t), β(r, t) and γ(r, t) of the rate of change of vorticity covariance of MHD turbulence depend on the defining scalarsW, T, R, PandFof the tensorsWij, Tij, RijPik, j, andFkj, ialready defined in the probl

ISSN:0363-907X    

DOI:10.1002/er.4440140508

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

年代:1990

数据来源: WILEY

ISSN:0363-907X    

DOI:10.1002/er.4440140509

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

年代:1990

数据来源: WILEY

ISSN:0363-907X    

DOI:10.1002/er.4440140501

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

年代:1990

数据来源: WILEY