ISSN:0145-7632    

DOI:10.1080/01457639008939725

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor

摘要:

Today, the refrigeration industry can choose among a wide variety of enhanced tubes for evaporators and condensers of chilled water systems. To evaluate the performance of such tubes under field conditions, the standard finned tubes of one of the two 250-ton (879-kW) water chillers in a building have been replaced by specific enhanced finned tubes for comparison.

ISSN:0145-7632    

DOI:10.1080/01457639008939726

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor

摘要:

An analytically based computer program was used to calculate the performance benefits provided by the use of enhanced tube geometries in an R-11 flooded refrigerant evaporator. Three different boiling surface geometries are evaluated: integral fins, and two different high-performance enhanced boiling surface geometries. Four water-side surface geometries are evaluated: a plain surface, a 10-ridge ribbed tube, a 30-ridge ribbed tube, and a corrugated tube. The performance analysis is applied to a 250-ton (879-kW) R-11 chiller operating at full load condition. The reference evaporator bundle has 180 tubes 135 in. (3.43 m7rpar; long, with two water-side passes. The analysis compares the performance benefits provided by the enhanced boiling surface with a plain internal diameter (ID7rpar; and with an enhanced ID. Analysis are provided to define the shell length reduction for specified operating conditions, and to define how much the saturation temperature may be increased for a bundle of fixed size. Analysis is also provided to determine the benefits provided by introducing the flash gas to the evaporator, and to determine the preferred bundle aspect ratio.

ISSN:0145-7632    

DOI:10.1080/01457639008939727

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor

摘要:

The porous-medium flat-plate solar collector is an interesting alternative to conventional fin-and-tube designs if higher pumping power requirements do not offset collector efficiency gains. In this paper, complementary to a transient two-phase heat transfer study where Darcy's law had been used, a non-Darcy flow equation and the convection-conduction heat transfer equation are solved numerically. The coupled fluid flow and heat transfer mechanisms are analyzed for a porous-medium solar collector, and its high-performance efficiency is compared with advanced tubular-type collectors.

ISSN:0145-7632    

DOI:10.1080/01457639008939728

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor

ISSN:0145-7632    

DOI:10.1080/01457639008939729

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor

摘要:

The editorial board [of Energiya] publishes this article with a certain amount of apprehension. This is because the author has his own unorthodox view of the nuclear power industry. Everybody knows that breaking stereotypes is extremely difficult. That is why a cursory reading of the article may only cause irritation and even panic. But we would like to hear opposing views supported by arguments. We will certainly publish the most interesting responses.

ISSN:0145-7632    

DOI:10.1080/01457639008939730

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor