摘要:

AbstractThe near‐south‐facing glazed wall of the Wallasey School admits large solar gains in sunny weather, sufficient to meet in full the heat need in cold weather. It permits large heat losses, however, and during dull weather, and during the long winter nights there is little or no compensating solar gain. The net effect of such glazing over a season might be either to save, or to waste energy as compared with a windowless building, according to the sunniness and coldness of the climate and the window characteristics. To examine the action of the glazing, use was made of 50 years of daily mean ambient temperature, and contemporary sunshine hours, in conjunction with the solar gain factor for the translucent and pinboarded areas of the solar wall, and for certain values of design temperature and ventilation rate. It is concluded that such glazing leads to modest savings, of around 5 to 10 W/m2daily average. Most of the saving appears to be achievable by around 30 per cent glazing; further glazed area tends to supply unwanted solar gain in sunny periods while increasing the losses in sunless conditions. The annual electricity consumptions are noted for the 20 year life of the building. Their costs suggest that the building has been economical to h

ISSN:0363-907X    

DOI:10.1002/er.4440110102

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

年代:1987

数据来源: WILEY

摘要:

AbstractAn experimental study has been carried out on a continuously operated pilot fractional distillation column equipped with an external heat pump. The distillation column was a 15 cm internal diameter glass unit containing eleven single bubble cap plates. A methanol‐water mixture was fed to the column. After operating the heat pumps with R114 as the working fluid, further experiments have been conducted with R11 as the working fluid. Plots of pressure against enthalpy, condensation pressure and latent heat of vaporization against condensation temperature and theoretical Rankine coefficient of performance against gross temperature lift and condensation temperature are presented for both R114 and R11. R11 has correspondingly higher theoretical Rankine coefficients of performance than R114. The experiments show that the actual coefficients are also higher for R11 than for R114. A maximum actual coefficient of performance of 5.3 was obtained using R11 as the working fluid with a gross temperature lift of 38.4°C. The experimental data for R11 were found to be reproducible during operation over a number of weeks. This showed that the relative thermal instability of R11 compared to R114 had not apparently affected the performance of the syst

ISSN:0363-907X    

DOI:10.1002/er.4440110103

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

年代:1987

数据来源: WILEY

摘要:

AbstractThe results of measurements on a few solar air and water heaters of the same design, but made from different plastic materials, are reported for different climatic conditions. The experiments on the systems were made over a long time period, first in Germany in 1982 and then in India in 1984. An economic evaluation shows that the use of such collectors can bring down the cost of solar energy in the desired economic scale. Despite the drawback of UV degradation of plastic material resulting in shorter lifetime, the low initial investment cost keeps the cost of useful energy also low.

ISSN:0363-907X    

DOI:10.1002/er.4440110104

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

年代:1987

数据来源: WILEY

摘要:

AbstractUsing a multiperiodal LP model (MARKAL) the authors assessed the likely potential of solar thermal and biogas systems under various circumstances. The study covered the period 1980–2005, in five segments of five years. It focused only on the subsystem of the energy end‐uses which can be substituted for by solar and biogas technologies.In this paper we show the main results of the study regarding the competitiveness of the single solar and biogas technologies in different scenarios and their sensitivity to incentives and prices, together with the essential technical data regarding demand and supply technologies which produced those results.The analysis performed of the potential penetration of renewable technologies into the Italian energy system shows that their contribution will remain very marginal if the price of conventional energy carriers remains constant in constant money. However, the objective of removing with renewable technologies 1.5 per cent of the total Italian energy consumption appears to be realistic in the short‐medium

ISSN:0363-907X    

DOI:10.1002/er.4440110105

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

年代:1987

数据来源: WILEY

摘要:

AbstractMeasurements of radiation, smoke and temperature in a developed experimental combustor at various air pressures, inlet temperatures and air‐fuel ratios have shown the effects of such fuel properties as volatility, boiling range and H percentage mass content on ignition, lean blow‐out, liner temperature and exhaust smoke.This study has been extended to cover some of these performance characteristics for shale

ISSN:0363-907X    

DOI:10.1002/er.4440110106

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

年代:1987

数据来源: WILEY

摘要:

AbstractAn interactive computer program has been developed to determine and to evaluate the optimal design of electricity distribution systems in rural areas. The program considers the costs and benefits of grid electrification, isolated diesel generators and centralized photovoltaics. It provides support for decisions on choices of technology. The program optimizes within the context of long‐term load and system expansion; it runs on a 384K CPU microcompute

ISSN:0363-907X    

DOI:10.1002/er.4440110107

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

年代:1987

数据来源: WILEY

摘要:

AbstractThermal energy storage (TES) enables more efficient use of conventional energy conversion plants and enhances the exploitation of renewable energy sources. Storage primarily promotes the replacement of heating oil with less expensive fuels, for instance biomass, coal or industrial waste heat. In this paper, some applications of heat storage for large‐scale and centralized residential heating systems are presented. Analysis methods to estimate the economy of storage in these energy‐systems are also derived. It was estimated that the maximum market potential for short‐ and long‐term heat storage in the present Finnish heat production system would correspond to about 1–1.3 TWh of supplied heat

ISSN:0363-907X    

DOI:10.1002/er.4440110108

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

年代:1987

数据来源: WILEY

摘要:

AbstractA mathematical model is presented for deep‐bed drying of grains which gives explicit expressions for the temperature and moisture contents of the grain, and the temperature changes of the drying air as functions of time and bed thickness. The model is based on heat and masss transfer relationships proposed by Brooker et al. (1978). The results of the numerical computation carried out using this model are in close agreement with the experimental results of Boyce (1965); the results are also compared with the theoretical results of O'Callaghan et al., (1971). The model is also applicable to situations when the inlet air parameters are functions of tim

ISSN:0363-907X    

DOI:10.1002/er.4440110109

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

年代:1987

数据来源: WILEY

摘要:

AbstractA method is proposed for the calculation of the benefits in power system interconnection which arise from the equilibration of marginal costs on the connected systems. The method is applied to the adjacent systems of Malaysia and Singapore. The benefits arising from the equilibration of marginal costs are shown to be significant compared to those which arise from the reduction of reserve margins.

ISSN:0363-907X    

DOI:10.1002/er.4440110110

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

年代:1987

数据来源: WILEY

摘要:

AbstractThis paper presents an investigation on using an ammonia refrigerant with liquid/solid absorbents in an absorber heat recovery cycle where heat released during the absorption process is used to heat up the strong solution coming out of the absorber, thereby reducing the generator heat input and hence improving the coefficient of performance. A comparative thermodynamic study is made with NH3‐H2O and NH3‐LiNO3pairs as working fluids for both conventional absorption and absorber heat recovery systems. It is found that an improvement of about 10 per cent in COP for the absorber heat recovery cycle is achieved over the conventional absorption cycle and the NH3‐LiNO3system yields a higher COP than for NH3‐H2O over a wide range of generator temperatures and condenser/absorber temperatures. A detailed parametric study is also presented in thi

ISSN:0363-907X    

DOI:10.1002/er.4440110111

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

年代:1987

数据来源: WILEY