ISSN:0145-7632    

DOI:10.1080/01457639008939737

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor

摘要:

Absorption of noncondensible gases by the condensate in large power plant condensers is extremely deleterious to plant components. Unfortunately, the absorption process is one of the most complicated and insufficiently researched problems of contemporary hydrodynamics. Additionally, removal of noncondensible gases dissolved in condensate at very low concentrations is extremely difficult from the technical as well as the theoretical points of view.

ISSN:0145-7632    

DOI:10.1080/01457639008939738

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor

摘要:

Heat transfer experiments of forced turbulent and laminar and combined laminar downflows of water were conducted in uniformly heated, triangularly arranged, seven-rod bundles having P/D ratios of 1.25, 1.38, and 1.5. In the experiments Re ranged from 148 to 2.85 × 104, Pr from 5 to 9, Raqfrom 6 × 104to 8 × 107, and Ri from 0.001 to 10. The data in the forced turbulent and the laminar flow regimes are in good agreement with the upflow correlations (within ± 15%). Also, the value of Reynolds number at the transition between these two regimes, which increased linearly with P/D ratio, is the same as that for upflow. In the laminar flow regime, the flow entering the heated section, except for the P/D ratio of 1.25, was developing hydrodynamically. However, the variation in Nu with axial location was small, suggesting that the flow in the heated rod bundles could have been developed thermally. The transition from forced laminar to combined flow occurred at Ri = 0.1, which is an order of magnitude lower than that for upflow. The combined flow data are correlated by superimposing the correlations for forced laminar and natural laminar flows as:

ISSN:0145-7632    

DOI:10.1080/01457639008939739

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor

摘要:

Key components of open-cycle ocean thermal energy conversion (OC-OTEC) systems—the flash evaporator, mist eliminator, passive predeaerator, two surface condenser stages, and mo direct-contact condenser stages—have been tested using seawater. These components operate at lower steam pressures and higher inlet noncondensable gas concentrations than do conventional power plant heat exchangers. The rate of heat exchanged between the evaporator and the condenser is on the order of 1.25 MW (thermal), requiring a warm seawater flow of about 0.1 m3/s; the cold seawater flow is on the order of half the warm water flow. In addition to characterizing the performance of the various components, the system has produced potable water from condensation of the steam produced in the evaporator. The information obtained in these tests is being used to design a larger-scale experiment in which net power production is expected to be demonstrated for the first time using OC-OTEC technology.

ISSN:0145-7632    

DOI:10.1080/01457639008939740

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor

摘要:

Although current crowding produced by flow around sharp reentrant conductor edges results in mathematically unbounded local heat sources, it is shown that the resulting temperature distributions are bounded and continuous for most operating conditions. Specific upper temperature bounds are derived. Consequences for conductor failure modes are discussed.

ISSN:0145-7632    

DOI:10.1080/01457639008939741

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor