摘要:

AbstractThe effects of mass transfer effectiveness of absorber on the performance of single stage vapour absorption heat transformers were studied by making a thermodynamic analysis. The refrigerant absorbent pairs considered were R21‐DMF and R21‐DMETEG. The variations in performance parameters such as coefficient of performance, exergetic efficiency, concentration difference and circulation ratio with mass transfer effectiveness of the absorber at various operating temperatures were computed. Increasing the effectiveness of absorber resulted in increases in coefficient of performance, exergetic efficiency and concentration differential across the absorber. The improvements in coefficient of performance and exergetic efficiency with mass transfer effectivensss of the absorber were more pronounced for the R21‐DMF pair than for R21‐DMETEG. Correlations are presented for quick estimation of performance under different operating con

ISSN:0363-907X    

DOI:10.1002/er.4440130602

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

年代:1989

数据来源: WILEY

摘要:

AbstractModifications made in a solar air collector inlet duct to achieve uniform velocity of air in the absorber duct are described. Measurements of temperature and pressure at various points in the duct gave information on the distribution of air in the absorber duct. A thermal performance test conducted on the collector with a vaned diffuser showed some significant improvement compared with a diffuser without vanes.

ISSN:0363-907X    

DOI:10.1002/er.4440130603

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

年代:1989

数据来源: WILEY

摘要:

AbstractPhotogalvanic effects were studied in a photogalvanic cell containing methylene blue, EDTA and NaLS as a photosensitizer, reductant and surfactant, respectively. The photocurrent and photopotential generated by this system were 190 μA and 654 mV, respectively. The effects of different parameters on the electrical output of the cell were observed. Current/voltage characteristics of the cell have also been studied, and a mechanism has been proposed for the generation of photocurrent in photogalvanic cell

ISSN:0363-907X    

DOI:10.1002/er.4440130604

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

年代:1989

数据来源: WILEY

摘要:

AbstractThe paper evaluates thermal NOxformation characteristics of high efficiency gas turbines using refuse‐recovered low Btu gases. First, an estimation model of nitric oxide (NO) formation density for the gas turbine is constructed by revising a model proposed by W. S. Y. Hung. Next, taking a gas turbine burning high Btu gas with a turbine inlet temperature of 1273 K as a reference case, its NO emission density is estimated. Parametric analyses are done on the parameters that greatly affect the NO formation characteristics for the reference gas turbine, and it is shown that there is a limit to the possible NO density reduction by only controlling these parameters. Thirdly, the effects on the NO density of increasing gas turbine efficiency, by incorporating a regenerator or by raising turbine inlet temperature, are investigated. It is shown that the NO density of a gas turbine with a high efficiency is estimated to be higher than the assumed environmental quality standard (EQS) value. Finally, by utilizing these results, the cases are investigated where refuse‐recovered low Btu fuels such as pyrolysis gas from municipal refuse are used. It is shown that the NO densities in these cases are estimated to be notably lower than the EQS value. Further, it is demonstrated that the use of low Btu fuel does not necessarily assure a low NO density, since the NO density is not determined only by the heating value of the f

ISSN:0363-907X    

DOI:10.1002/er.4440130605

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

年代:1989

数据来源: WILEY

摘要:

AbstractThe response of temperature sensors depends on the thermophysical properties, flow rates, temperatures and pressures (for compressible fluids) of fluid in which they are immersed. Analysis indicates that the time of response is inversely proportional to the heat transfer coefficient and to a power of the velocity of the ambient fluid. The paper is concerned with the validity of these relations. Experimentation involved (a) different liquids, (b) different velocities, and (c) different sensors. Extensive testing and curve‐fitting of the results is shown not to lead to absolute validation of the relation between the time constant and the head transfer coefficient. The latter was based on a particular correlation. The results are discusse

ISSN:0363-907X    

DOI:10.1002/er.4440130606

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

年代:1989

数据来源: WILEY

摘要:

AbstractThe operating environment for a domestic air‐air heat pump installation is examined using data from a field monitoring study. The unit, which is used for heating only, has a seasonal COP of 2.7 ± 0.2. The system experiences a wide range of return air temperatures, which are also low compared with those of normal designs. We show that this is partly caused by the heating patterns adopted by the occupants, by which the primary living area is well heated but the secondary area receives background heating on

ISSN:0363-907X    

DOI:10.1002/er.4440130607

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

年代:1989

数据来源: WILEY

摘要:

AbstractA thermodynamic analysis performed on a single‐stage vapour absorption heat transformer brings out the influence of mass transfer effectiveness of the generator on its performance parameters. The working fluid pairs considered for the heat transformer are R21‐DMF and R21‐DMETEG. The variations in the performance parameters, namely, heating coefficient of performance, exergetic efficiency, concentration difference and circulation ratio, with the changes in generator effectiveness are studied. As expected, an increase in generator effectiveness results in the improvement of the coefficient of performance, exergetic efficiency and concentration difference across the absorber. The extent of improvement is more pronounced for R21‐DMETEG than for R21‐DMF. Correlations are presented for quick estimation of performance parameters under different operating c

ISSN:0363-907X    

DOI:10.1002/er.4440130608

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

年代:1989

数据来源: WILEY

摘要:

AbstractThe economic effect of a natural resource discovery is an important and contentious issue, and clearly of particular relevance to economies such as Australia and the UK with booming mineral sectors. Such a discovery may have adverse or beneficial effects on other sectors of the economy such as manufacturing, and on the economy as a whole, which would require an appropriate macroeconomic policy response by the government. The paper explores such issues.The conceptual framework adopted is that developed by Dornbusch (1976), which specifically analysed the macroeconomic effects of changes in the money supply. In this model financial markets are efficient and forward looking, but nonfinancial markets are inefficient and backward looking. The extensions to this framework, to capture the economic effects of natural resource production, are identified, as well as the conflicting economic and policy conclusions derivable from alternative amendments and assumptions of the model. Dutch disease effects can be observed from this conceptual framework, a phenomenon which has been observed in energy abundant economies such as Australia, Holland, and the UK.A simulation of the conceptual framework identifies both in more detail and quantitatively, the possible adjustment processes following a natural resource discovery.The major conclusions to be derived from this paper are that except in unrealistic circumstances; specifically where there is no lag in the demand for nonenergy output arising from revenue generated in the energy sector, and energy production does not directly affect the demand for money, or where domestic prices are perfectly flexible, there will be a period of time during the adjustment process where non‐oil output would decline below its full employment level. Hence the general situation is one where energy production will require an appropriate macroeconomic policy response by the government, if minimising its adverse effects on other sectors of the economy and of maintaining non‐oil output at, or close to, its full employment level is an important prior

ISSN:0363-907X    

DOI:10.1002/er.4440130609

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

年代:1989

数据来源: WILEY

摘要:

AbstractThe ability of an external opaque wall of a room to perform two functions, i.e. to store the thermal energy when it reaches thermal equilibrium under solar radiation, and to exploit the stored thermal energy during the transient phenomenon of the wall thermal restoration after the interruption of solar radiation flux, was analysed. Analytical expressions have been obtained for the ability of the wall to store and exploit solar radiation, and for the resulting thermal gain of the room during the transient state of its thermal restoration.

ISSN:0363-907X    

DOI:10.1002/er.4440130610

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

年代:1989

数据来源: WILEY

摘要:

AbstractThe air gap between absorber and cover glazing in fiat plate collectors has been optimized experimentally by designing three identical collector‐cum‐storage type solar water heaters with 25, 50 and 150 mm air gaps. The heater with 50 mm air gap collects 11.64% and 7.72% more energy compared with heaters having 25 mm and 150 mm air gaps, respectively. The average overall efficiencies of the heaters are 52.5%, 57.8% and 54.1% having 25, 50 and 150 mm air gaps. A 50 mm air gap has, therefore, been found to be opti

ISSN:0363-907X    

DOI:10.1002/er.4440130611

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

年代:1989

数据来源: WILEY