ISSN:0145-7632    

DOI:10.1080/01457638708962810

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

ISSN:0145-7632    

DOI:10.1080/01457638708962811

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

ISSN:0145-7632    

DOI:10.1080/01457638708962812

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

ISSN:0145-7632    

DOI:10.1080/01457638708962813

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

ISSN:0145-7632    

DOI:10.1080/01457638708962814

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

ISSN:0145-7632    

DOI:10.1080/01457638708962815

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

ISSN:0145-7632    

DOI:10.1080/01457638708962816

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

摘要:

The problems encountered in the air-side performance of air-cooled heat exchangers are discussed with particular reference to airflow measurement. The variability of the airflow in and around the plenum and tube bundle of forced draft exchangers is described, as well as the difficulty in using static pressure determinations as an indication of fan and system efficiency. Measuring techniques and instrumentation are dealt with, and a recommendation is made for the best method and type of instrument currently available for determining airflow. The effects of air-side flow reduction and maldistribution on the thermal performance are also examined by reference to a typical forced draft exchanger in both condensing and cooling duty. In each case the condenser is more sensitive to flow variations than the cooler is. Generally, the effect of flow reduction is more serious than maldistribution unless crosswinds become dominant.

ISSN:0145-7632    

DOI:10.1080/01457638708962817

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

摘要:

Temperatures were measured at several points on the liner and firedeck of an insulated 2-L single-cylinder, open-chamber, diesel engine. These temperatures were found to vary significantly with location. The results of these measurements were compared with the predictions of a three-dimensional time-varying thermostructural model incorporating a single-zone thermodynamic simulation of the gas cycle. On the basis of this comparison, values for several thermal boundary conditions required for engine design were deduced. Using these values, relatively good agreement was found between the experiment and model across the range of experimental conditions.

ISSN:0145-7632    

DOI:10.1080/01457638708962818

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

摘要:

Two different cases of evaporator tube ruptures in power station boilers due to natural circulation distortion are presented. The first case discussed concerns a 110-MW, unit boiler with bottom evaporation tubing inclined at 15° to the horizontal. At the high heat fluxes present in the furnace, subcooled boiling occurs in inclined tubes. For these inclinations an insufficient flow rate causes local heat transfer deficiencies due to vapor-water separation. The introduction of internally finned tubes eliminates local heat transfer deficiencies and prevents further tube failures. The second case is that of circulation interruption due to blowdown during start-up. The water level in the drum of this second 110-MW, unit boiler was controlled by inlet header blowdown during start-up. Thus, natural circulation was interrupted, causing local overheating of evaporator tubing. The event was identified by an increase of the tube rupture frequency. After changing the blowdown procedure, the interruptions of natural circulation were avoided and the tube failure frequency decreased substantially.

ISSN:0145-7632    

DOI:10.1080/01457638708962819

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor