Accurate heat transfer measurement for condensation on horizontal, integral-fin tubes

Journal Article · Sat Aug 01 04:00:00 EDT 1992 · Journal of Heat Transfer (Transactions of the ASME (American Society of Mechanical Engineers), Series C); (United States)

DOI:https://doi.org/10.1115/1.2911340· OSTI ID:6915234

Briggs, A; Wen, X -L; Rose, J W ^[1]

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1. Univ. of London (United Kingdom)

In most earlier experimental investigations of condensation on low-fin tubes, vapor-side heat transfer coefficients have been found from overall (vapor-to-coolant) measurements using either predetermined coolant-side correlations or 'Wilson plot' methods. When the outside resistance dominates, or is a significant proportion of the overall resistance, these procedures can give satisfactory accuracy. However, for externally enhanced tubes, and particularly with high-conductivity fluids such as water, significant uncertainties may be present. In order to provide reliable, high-accuracy data, to assist in the development of theoretical models, tests have been conducted using specially constructed plain and finned tubes fitted with thermo-couples to measure the tube wall temperature, and hence the vapor-side heat transfer coefficient, directly. The paper describes the technique for manufacturing the tubes and gives results of systematic heat transfer measurements covering the effects of fin height, thickness, and spacing, tube diameter, and vapor velocity. The tests were carried out with steam, ethylene glycol, and R-113, with vertical vapor downflow. The heat flux was measured using an accurately calibrated 10-junction thermopile and paying particular attention to coolant mixing and isothermal immersion of thermocouple junctions. Care was taken to avoid errors due to the presence in the vapor of noncondensing gas and the occurrence of dropwise condensation. Smooth, consistent, and repeatable results were obtained in all cases. The data are presented in easily accessible form and are compared with the result of previous investigations, where indirect methods were used to determine the vapor-side data, and with theory.

• OSTI ID: 6915234
• Journal Information: Journal of Heat Transfer (Transactions of the ASME (American Society of Mechanical Engineers), Series C); (United States), Journal Name: Journal of Heat Transfer (Transactions of the ASME (American Society of Mechanical Engineers), Series C); (United States) Vol. 114:3; ISSN JHTRAO; ISSN 0022-1481
• Country of Publication: United States
• Language: English

Related Subjects

42 ENGINEERING
420400* -- Engineering-- Heat Transfer & Fluid Flow
ALCOHOLS
AUGMENTATION
CHLOROFLUOROCARBONS
ENERGY TRANSFER
FINS
GLYCOLS
HEAT FLUX
HEAT TRANSFER
HYDROXY COMPOUNDS
MEASURING METHODS
ORGANIC CHLORINE COMPOUNDS
ORGANIC COMPOUNDS
ORGANIC FLUORINE COMPOUNDS
ORGANIC HALOGEN COMPOUNDS
ORIENTATION
STEAM
TUBES
VAPOR CONDENSATION