摘要:

AbstractThis paper presents an investigation of an ammonia‐water absorption cycle for solar refrigeration, airconditioning and heat pump operations at higher heat supply temperatures. The system consists of a solar driven generator, rectifier, condenser, evaporator, absorber and heat exchangers for preheating and subcooling within the system. A steady state thermodynamic cycle analysis based on mass and heat balances along with the state equations for the thermodynamic properties of the ammonia‐water mixture has been carried out. A numerical computer simulation of the system with input component temperatures, refrigerant concentration/mass flow rate and effectiveness of the heat exchangers has been made to evaluate the relative heat transfer rates (i.e. coefficients of performance) and the mass flow rates for the cooling/heating modes.It is found that unlike the low generator temperature behaviour the coefficients of performance for both cooling and heating modes are reduced at higher generator temperatures. However, an increase of condenser temperature for each mode of operation improves the performance of the systems at higher generator temperatures. A choice for keeping the absorber temperature equal to/lower than that of the condenser is also predicted at lower/higher generator temperatures, respectively. In general the results are more pronounced for the refrigeration mode than for the heat pump mode and are least effective for the airconditioning m

ISSN:0363-907X    

DOI:10.1002/er.4440060302

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

年代:1982

数据来源: WILEY

摘要:

AbstractAn improved hot box type solar cooker (SC‐2) has been designed, developed and tested. It is an improvement on the solar cooker SC‐1 earlier developed at the institute. The cooking chamber has properly been optimized for cooking the food for a family of five persons. A rubber gasket has been provided at the boundary of the openable door to prevent the leakage of hot air, thus increasing the pressure in the cooking chamber. Different cooking trials like boiling, roasting and baking were successfully conducted and the cooker was found useful from 8.00 a.m. to 5.00 p.m., even during a winter month. The efficiency of the cooker was found to be 41.2 per c

ISSN:0363-907X    

DOI:10.1002/er.4440060303

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

年代:1982

数据来源: WILEY

摘要:

AbstractCondensers used in tap water heat pumps are either of the integrated passive immersion type or separate units with active water circulation. The use of the active circulation configuration together with a counter‐flow condenser and water flow control has a number of advantages compared to passive immersion condensers. In particular, hot water temperatures above the saturation temperature of the condensing refrigerant are possible. The counter‐flow arrangement also permits sub‐cooling gains in cycle efficiency. These two features offset the pumping power penalty which would not be necessary in a system with a passive immersion cond

ISSN:0363-907X    

DOI:10.1002/er.4440060304

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

年代:1982

数据来源: WILEY

摘要:

AbstractAn analysis of steady two‐dimensional flow, of an electrically conducting fluid through a porous medium, occupying a semi‐infinite region of the space bounded by an infinite, vertical and porous limiting surface under the action of a transverse magnetic field is considered. Approximate solutions have been derived for the velocity and temperature fields and the rate of heat transfer (Nusselt number). The variations of the velocity and Nusselt number are shown on gra

ISSN:0363-907X    

DOI:10.1002/er.4440060305

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

年代:1982

数据来源: WILEY

摘要:

AbstractThe photogalvanic behaviour of iron‐thionine and iron‐methylene blue systems in the presence of surfactants has been studied. The data indicate that the surfactant micelles can be utilized for the storage of light ene

ISSN:0363-907X    

DOI:10.1002/er.4440060306

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

年代:1982

数据来源: WILEY

摘要:

AbstractThis paper presents a brief review of the available latent heat storage systems for solar energy utilization. A new concept of latent heat storage of solar energy via the refrigerant‐absorbent mass storage in absorption cycle heat pump systems used for solar space heating/cooling has been proposed and assessed thermodynamically. A computer modelling and numerical simulation study shows that the concept of refrigerant storage is fundamentally sound, technically feasible and yields the following advantages over other storage methods: (i) the storage capacity per unit volume is high as the latent heat of vaporization of the refrigerant is high; (ii) the heat loss from the storage to the surroundings is minimum as the storage temperature is near the ambient; (iii) prolonged energy storage is possible with no degradation in system performance and hence suitable for combined solar heating and airconditioning. The effects of operating parameters on the energy storage concentration and storage efficiency have been studied in detai

ISSN:0363-907X    

DOI:10.1002/er.4440060307

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

年代:1982

数据来源: WILEY

摘要:

AbstractThe distribution of local concentration ratio on a fin receiver used with cylindrical parabolic solar concentrators has been calculated analytically considering the variation of intensity over the solar disc. The effect of the pointing error of the concentrator and that of the lateral shift and tilt of the fin receiver have also been studied. The results are plotted graphically and discussed.

ISSN:0363-907X    

DOI:10.1002/er.4440060308

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

年代:1982

数据来源: WILEY

摘要:

AbstractA plan for the management of alternative sources of energy, namely, wind, solar and biomass, available in a typical village of arid area has been formulated and it is found that the energy potential available in the village from mid February to mid September is much more than the energy requirement of the village; and during the remaining period the energy available is about 78.5 per cent of the energy requirement. Appropriate technologies for the effective and efficient use of these energies are earmarked so as to convert the energy potential available into useful energy.

ISSN:0363-907X    

DOI:10.1002/er.4440060309

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

年代:1982

数据来源: WILEY

摘要:

AbstractIn MHD generator channels, the actual gas flow is often approximated by a certain hydraulic flow model which requires an appropriate empirical velocity profile model. The existence of a general 1/m‐power law for the velocity profile withmvarying from 6 to 8 in small‐scale MHD generator channels has been discussed. The effect of change inmgiving rise to various velocity profiles on the gasdynamic voltage drop has been studied. It is found that the gasdynamic voltage drop is affected considerably by changing the power law for the velocity profile, demanding an appropriate velocity profile model for the analysis of d

ISSN:0363-907X    

DOI:10.1002/er.4440060310

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

年代:1982

数据来源: WILEY

摘要:

AbstractA solar device has been developed for manufacturing candles from paraffin wax, utilizing solar energy. The design, operation and performance of the device have been described. It is concluded that the device can be used for saving fuel, minimizing the loss of wax due to the vaporization and labour.

ISSN:0363-907X    

DOI:10.1002/er.4440060311

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

年代:1982

数据来源: WILEY