ISSN:0145-7632    

DOI:10.1080/01457638108939604

出版商:Taylor & Francis Group    

年代:1983

数据来源: Taylor

摘要:

Functional relations are derived to determine the reduction in the heat duty of a multipass heat exchanger due to tube-side fluid bypass. A simplified structural model of the channel cover is constructed to determine the interpass leakage due to cover deflection under pressurized (operating) conditions. A numerical example shows that design rules based on stress limits are adequate to keep interpass leakage within tolerable limits.

ISSN:0145-7632    

DOI:10.1080/01457638108939605

出版商:Taylor & Francis Group    

年代:1983

数据来源: Taylor

摘要:

The heat transfer process in a split-flow heat exchanger designated as G type by TEMA standards is analyzed for two cases: with one tube pass and with two tube passes. Equations are presented for the shell fluid temperature distribution as a function of exchanger length or surface area. The thermal performance of the two-tube-pass exchanger is compared with those of a 1:1 counterflow exchanger and a one-pass split-flow exchanger. Results are presented in terms of temperature efficiency, reduced thermal flux (NTU), and thermal flow rate ratio.

ISSN:0145-7632    

DOI:10.1080/01457638108939606

出版商:Taylor & Francis Group    

年代:1983

数据来源: Taylor

摘要:

Direct immersion of electronic components in low-boiling point, dielectric fluids can provide a benign local ambience and accommodate substantial spatial and temporal power variations while minimizing component temperature excursions and failure rates. Following a review of possible immersion cooling configurations and the thermal mechanisms active in vapor-space and submerged condenser modules, attention is focused on the operational limits and relations for predicting submerged condenser performance. Finally, descriptions of three likely applications of submerged condenser technology are presented.

ISSN:0145-7632    

DOI:10.1080/01457638108939607

出版商:Taylor & Francis Group    

年代:1983

数据来源: Taylor

摘要:

In its simplest form, a heat exchanger consists of a bundle of tubes arranged between two thick perforated tube plates and enclosed by an outer shell. Covers over the tube plates allow one fluid to pass inside the tubes while a second hotter or cooler fluid is introduced via openings in the shell. Since they contain no moving parts it might be expected that heat exchangers would be highly reliable pieces of equipment. However, everyday experience with small domestic and automotive heaters and coolers suggests this is not always the case. In the case of mass-produced items such as these, replacement of a defective component is usually relatively straightforward and inexpensive. However, for the much larger heat exchangers used in the process chemical and power industries, a single failure may result in significant financial losses.

ISSN:0145-7632    

DOI:10.1080/01457638108939608

出版商:Taylor & Francis Group    

年代:1983

数据来源: Taylor

摘要:

The methods of control of air-cooled heat exchangers, including control by louvers, are discussed. A test apparatus for measuring the pressure drop of louvers is described, and the results are compared with airflow measurements on a full-sized, air-cooled condenser fitted with louver control. These measurements compare well with predictions made from laboratory tests and theoretical analysis.

ISSN:0145-7632    

DOI:10.1080/01457638108939609

出版商:Taylor & Francis Group    

年代:1983

数据来源: Taylor

摘要:

Boiling test results and theoretical evaluations related to predictive models for the boiling coefficient with porous coatings are critically surveyed. Consideration is limited to boiling pure fluids and coatings made of spherical particles of uniform diameter. The data for seven different porous coatings suggest that particle diameter has very little effect on performance. The preferred coating thickness is in the range of three to four particle diameters. Detailed consideration of cavity stability requirements suggests that a dynamic model is needed to rationally predict the boiling coefficient. A modified pore classification is proposed for use in the development of a dynamic model. The assumption and derivation of O'Neill's static boiling model is presented. Its ability to predict the boiling coefficient is evaluated by a comparison with the values predicted by an empirical correlation developed by Nishikawa and Ito.

ISSN:0145-7632    

DOI:10.1080/01457638108939610

出版商:Taylor & Francis Group    

年代:1983

数据来源: Taylor

摘要:

The paper outlines application of gas dynamic functions (GDF) for practical design of steam ejectors. Some experimental results on designed ejectors are presented. An extensive table of GDF for saturated steam (k  =  1.135) is also included.

ISSN:0145-7632    

DOI:10.1080/01457638108939611

出版商:Taylor & Francis Group    

年代:1983

数据来源: Taylor

摘要:

A simple dimensionless correlation is presented and compared with data from 35 experimental studies. Data include spheres, horizontal and vertical cylinders, cylinder diameters from 0.13 to 220 mm, particle diameters from 104 to 15,000 μm, bed temperatures up to 900° C, and bed pressures up to 9.25 bars. Fluidizing gases include air, helium, CO2, H2, and R-12. Particle densities range from 1986 to 11,340 kg/m3and psCsfrom 1474 to 4173 kJ/m2 °C. A total of 142 data points are correlated with a mean deviation of 17%. Complete tabulations are provided for all data analyzed. Application to tube bundles is discussed briefly.

ISSN:0145-7632    

DOI:10.1080/01457638108939612

出版商:Taylor & Francis Group    

年代:1983

数据来源: Taylor