摘要:

AbstractDependence of the cooling potential of an evaporative cooling tower on the tower parameters (heighth, cross‐sectional areaAt, evaporative pad areaAp, packing factor of evaporating padsFpand flow resistancef) has been investigated. The performance of the tower is studied for two different climates, namely hot‐dry and composite, typified by Jodhpur and De

ISSN:0363-907X    

DOI:10.1002/er.4440150102

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

年代:1991

数据来源: WILEY

ISSN:0363-907X    

DOI:10.1002/er.4440150103

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

年代:1991

数据来源: WILEY

摘要:

AbstractThe thermal behaviour of a packed bed storage system charged with hot air is modelled using two partial differential equations representing the energy conservation in the air and solid phases constituting the bed. These two equations are coupled through the heat exchange process between the two phases.A fully implicit numerical scheme based on forward, upwind and central differencing for the time, first and second space derivatives, respectively, is used to solve the modelling equations. Marching technique is used for the air equation and a tri‐diagonal matrix solver is employed to solve the solid equation. The solution yields the thermal structure of the bed, namely the air and solid temperature distribution inside the bed at any particular time, and the variation of total energy stored in the bed with time. The effect of bed length, solid diameter and void fraction on the thermal characteristics of the packed bed is studied. Further, the performance of the bed under variable inlet air temperature and mass flow rate is investigate

ISSN:0363-907X    

DOI:10.1002/er.4440150104

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

年代:1991

数据来源: WILEY

摘要:

AbstractThermodynamic, heat transfer and economic concepts influencing the synthesis of a heat‐exchanger network (HEN) coupled to a crude fractionation unit are examined. The impact of the variation of the minimum temperature approach (Δtmin) on energy and capital targets is studied using recent developments in pinch technology. The optimal pinch approach temperature has been determined using the ‘supertargeting’ concept where proper trade‐off between energy and capital targets is observed prior to design. A heuristic evolutionary approach has then been used for the generation of the opt

ISSN:0363-907X    

DOI:10.1002/er.4440150105

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

年代:1991

数据来源: WILEY

摘要:

AbstractThe paper presents a comparative thermodynamic analysis of seven candidate vapour‐compression heat pump working fluids, namely R‐11, R‐12B1, R‐21, R‐113, R‐114, R‐142b and R‐216. The basis for evaluation is the temperature‐boost/pressure‐penalty ratio and the heat of vaporization. Four of the above refrigerants are covered under the Montreal Protocol. It is observed that R‐21 and R‐216 are effective alternatives for low grade heat recovery and R‐142b for comfort heating. The fluids are compared for ideal operating temperature limits of each refrigerant as well as a f

ISSN:0363-907X    

DOI:10.1002/er.4440150106

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

年代:1991

数据来源: WILEY

摘要:

AbstractThe recently developed transient plane source (TPS) technique has been applied for the simultaneous measurement of thermal conductivity and thermal diffusivity of two composite materials namely, marble and magnesium oxychloride cement in the range of temperatures from 30 to 150°C. The experimental results of these samples show that there is very slight variation in thermal conductivity and thermal diffusivity of these materials in this range of temperature. An effort has been made to express this variation of thermal conductivity and diffusivity with temperature by a linear relation, in these materials

ISSN:0363-907X    

DOI:10.1002/er.4440150107

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

年代:1991

数据来源: WILEY

摘要:

AbstractThe paper is concerned with simulating the macroeconomic adjustment processes arising in a small open economy experiencing a temporary period of oil production. In a recent paper, Harvie conducted a similar exercise for an economy in which the spending effect arising from such oil production dominated the resource movement effect. That paper concluded that the wage adjustment processes operative were important in influencing the macroeconomic adjustment process arising. Specifically, that paper concluded that wage indexation was preferable during the period of oil production, but that de‐indexation was preferable in the post oil production period. Although, in the present paper, the principles underlying the simulated model are the same as in Harvie, the emphasis here is placed on the resource movement consequences arising from temporary oil production. The major conclusion identified is that wages policy is still important in influencing the macroeconomic adjustment processes identified. However, a difference arises not in regard to the profile of that adjustment but rather in its magnitude. The paper emphasizes, in particular, developments in non‐oil output, consumer prices, and the stock of domestically held foreign assets. The simulation results suggest that, where the resource movement effect dominates, it would be preferable to de‐index wages during the period of oil production and index wages in the post oil production period. Hence wages policy should be regarded as an important component of a government's policy response arising from a period of temporary oil production, irrespective of whether the resource movement or spending effect dominates. However, what that policy response should be would depend on the relative importance of either e

ISSN:0363-907X    

DOI:10.1002/er.4440150108

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

年代:1991

数据来源: WILEY

摘要:

AbstractThe paper is concerned with the development of a simplified linear model which attempts to optimize the cost function of an energy supply system consisting of a mix of energy resources and conversion devices, each of which may have a constraint with respect to availability, efficiency and cost. The model has been applied in three villages, from three different physiographic zones of Nepal, for which detailed data were collected and analysed. The results of the study show that the optimized use of different energy sources in different regions is strongly dependent on demographic and climatic parameters. For hill villages, hydropower could become the cheapest source of energy if technical options were provided, but until then more efficient use of wood is the only viable solution. Commercial sources like kerosene and LPG are not likely to play any significant role in hill and mountain villages. On the other hand, the use of biogas is economically most feasible in Terai village. The availability of kerosene rules out wood or agriculture waste as feasible solutions for cooking energy needs, as this village is closer to the Indian border and has good road access.

ISSN:0363-907X    

DOI:10.1002/er.4440150109

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

年代:1991

数据来源: WILEY

ISSN:0363-907X    

DOI:10.1002/er.4440150101

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

年代:1991

数据来源: WILEY