摘要:

AbstractAn analytical and experimental investigation of transient turbulent two‐dimensional charging and discharging of a sensible heat storage tank has been conducted. Parametric studies showed that the turbulent mixing factor due to hydrodynamic disturbances at the inlet ports is the most significant item in the performance of thermal stratification storage tanks. Furthermore, the effect of the aspect ratio and convection at the walls in promoting stratification have been studied. Comparison with experimental data showed the capability of the present analytic approach to accommodate, with a satisfactory degree of accuracy, such problem

ISSN:0363-907X    

DOI:10.1002/er.4440170202

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

年代:1993

数据来源: WILEY

摘要:

AbstractThe paper describes the development of a windmill simulator, to simulate accurately the movement of a windmill. The simulator has a model to facilitate the change of windmill parameters, such as power coefficient or moment of inertia, by overcoming the weak points in the research and development environment for wind utilization, especially with the purpose of improving methods of windmill speed control or output. Also, to determine further the dynamic characteristics of the windmill speed with great accuracy, the simulator has a motor model to compensate for the slow response of the DC motor itself. The simulator is mainly composed of a separately‐excited DC motor to directly simulate the movement of the windmill, a high‐output DC amplifier to drive the motor, and a personal computer for control. It is ascertained that the developed simulator can fully reproduce the stationary and dynamic characteristics of a windmill from the experimental results. Also, a method is described to control the blade pitch angle to keep a windmill rotational speed constant. The results of the numerical simulation agree with the characteristics of the windmill simulator, and the effectiveness of the blade pitch angle control of the simulator is also affir

ISSN:0363-907X    

DOI:10.1002/er.4440170203

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

年代:1993

数据来源: WILEY

摘要:

AbstractThe optimal allocation of energy resources to various energy end uses is an important strategy for bridging the energy supply and demand gap in India. It has been recognized that the allocation should be guided by multiple criteria. A multiobjective programming model for such an allocation process is presented in the paper. The normative model has been applied for the households sector of Madras city. The model is solved using non pre‐emptive goal programming. Variations in the original model have been made to build alternative scenarios. The results of the original model and the alternative scenarios indicate that the use of solar thermal energy, natural gas, LPG, fuelwood, kerosene and lignite should be promoted for cooking, and the use of grid electricity and diesel, should be promoted for meeting water pumping demands. They favour the use of electricity generated from diesel for lighting, and the use of solar photovoltaics for meeting the electricity demands of household appliances. The results also indicate that grid electricity and electricity generated from fuelwood should be promoted to meet the demands of all the four household end uses, and point to the need for more research into solar photovoltaics, which may become competitive for meeting household demands in the futur

ISSN:0363-907X    

DOI:10.1002/er.4440170204

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

年代:1993

数据来源: WILEY

摘要:

AbstractIt is seen that the convergence of values of the elements of the admittance matrix for periodic heat conduction through an inhomogeneous slab with a number of layers (layered structure method) is much faster when the conductivity profile in the layer is taken as linear (with least‐square fit), than when the layer is considered as homogeneou

ISSN:0363-907X    

DOI:10.1002/er.4440170205

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

年代:1993

数据来源: WILEY

摘要:

AbstractThe thermal performance of a room with two indirect evaporative cooling systems (operating independently and jointly) is analysed. The two evaporative systems considered are a water‐film roof evaporative cooling system, and an underground water storage tank beneath the floor of the room. The water in the tank is evaporatively cooled through a suitable aeration system. The performance of the room is analysed in the hot‐dry climate of Jodhpur and the composite climate of Delhi. It is found that the underground water storage system is marginally better than the roof evaporative cooling system for the Jodhpur and Delhi climates. A detailed parametric performance analysis of the room has also been carried

ISSN:0363-907X    

DOI:10.1002/er.4440170206

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

年代:1993

数据来源: WILEY

ISSN:0363-907X    

DOI:10.1002/er.4440170207

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

年代:1993

数据来源: WILEY

ISSN:0363-907X    

DOI:10.1002/er.4440170201

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

年代:1993

数据来源: WILEY