Refrigerant Forced-Convection Condensation Inside Horizontal Tubes.

Bae, Soonhoon; Maulbetsch, John S.; Rohsenow, W. M.

doi:10.2172/4811535

Cited by 29 publications

(34 citation statements)

References 8 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…It should be noted that these correlations were restricted to a particular range of flow conditions. Bae et al (1969Bae et al ( , 1971 confirmed the validity of this correlation. Magiros and Dukler (1961).…”

Section: Introductionsupporting

confidence: 67%

Augmentation of in-tube evaporation and condensation with micro-fin tubes using refrigerants R-113 and R-22

Khanpara

View full text Add to dashboard Cite

Section: Introductionsupporting

confidence: 67%

Augmentation of in-tube evaporation and condensation with micro-fin tubes using refrigerants R-113 and R-22

Khanpara

View full text Add to dashboard Cite

“…The annular film model developed follows the basic elements set up by Rohsenow and coworkers (Rohsenow et al 1956, Bae et al 1971, Traviss et al 1973. A turbulent vapor core is assumed to be surrounded by a uniform liquid film.…”

Section: Liquidmentioning

confidence: 99%

Characteristics of Refrigerant Film Thickness, Pressure Drop, and Condensation Heat Transfer in Annular Flow

Hurlburt¹,

Newell²

1999

HVAC&R Research

View full text Add to dashboard Cite

Results are presented for void fraction, pressure drop, and condensation heat transfer for refrigerants R-11, R-12, R-22, and R-134a over a range of mass fluxes, qualities, and tube sizes. General characteristics and trends in void fraction, pressure drop, and heat transfer for different refrigerants are discussed. Annular flow modeling relations are used to develop ratiometric equations for liquid fraction, pressure drop, and heat transfer that allow general trends to be predicted when the operating parameters of a refrigeration system are changed. INTRODUCTIONThe recent conversion to alternative refrigerants and the continued search for new refrigerants have resulted in a significant number of recent investigations exploring characteristics of refrigerants in condensation and evaporation (Schlager et al. these investigations are resulting in better models (e.g., Jung and Radermacher 1991, Dobson and Chato 1998, Kattan et al. 1998c) that are being built directly on an extensive refrigerant database rather than the models of the past that often relied on data from fluids other than "refrigerant-like" fluids.The purpose of this paper is to examine three primary characteristics of refrigerants during condensation: void fraction, pressure drop, and heat transfer. When a refrigeration system is designed, these are the characteristics that determine how much tubing is required (heat transfer), how much refrigerant will be required (void fraction), and how much power will be required to move the refrigerant through the tubing (pressure drop). Additionally, comparisons between refrigerants of the past and present are explored. These results are used to provide guidance for estimating how design changes (refrigerant, tube size, mass flow rate) may affect a system.A mechanistic model based on uniform annular flow in a tube is the basis for the modeling. Although refrigerants at condensation conditions tend to pass through a variety of flow regimes as they move from high-to low-quality conditions, the annular flow region tends to be the central region that dominates most in-tube condensation conditions and therefore provides a useful reference to explore the significance of deviations between predicted and experimental conditions as one moves into other flow regions.This paper is organized into three sections. First, a background section describes the uniform annular flow model. The model allows a consistent basis for predicting void fraction, pressure drop, and heat transfer. Next, results from model predictions are compared to experimental data from a past study of common older refrigerants (R-11, R-12, and R-22) and from a more recent 230 HVAC&R RESEARCH study of R-134a and R-22. Finally, some simple relations are developed to provide guidance in determining how a change of system parameters affects void fraction, pressure drop, and heat transfer. These relations are set up in a manner similar to the fan laws.

show abstract

“…Сравнение экспериментальных данных с рас-четными, основанными на аналогичных моделях, описанных выше, показали хорошую сходимость экспериментальных α, полученных в работах [2,3], напротив в работе [4] наблюдалось отклонение экс-периментальных данных от расчетных при х > 0,5 ÷ 0,6.…”

Section: сравнение теоретических (полу-эмперических) решений с экunclassified

“…Для расчета параметров ручья и теплоотда-чи в нeм имеется несколько решений. Для расчета теплоотдачи при кольцевом течении пленки под дей-ствием скорости пара существует теоретические ре-шение Нуссельта для ламинарного течения пленки конденсата [1], а также несколько решений для турбу-лентной пленки, например в работах [2][3][4][5][6].…”

Section: Introductionunclassified

Конденсация Внутри Гладких Горизонтальных Труб. Сравнение Теоретических Решений И Экспериментальных Данных

Горін¹

2017

RET

View full text Add to dashboard Cite

show abstract

Refrigerant Forced-Convection Condensation Inside Horizontal Tubes.

Abstract: Experimental data was obtained for the flow rate from 240,000 to 485,000 lbm/ft2 hr. R-22 was condensed in a 0.493" I.D. 18 ft. long test section. The measured heat transfer coefficients agreed with the prediction within 10% except a few points in the very low quality region.

Cited by 29 publications

References 8 publications

Augmentation of in-tube evaporation and condensation with micro-fin tubes using refrigerants R-113 and R-22

Augmentation of in-tube evaporation and condensation with micro-fin tubes using refrigerants R-113 and R-22

Characteristics of Refrigerant Film Thickness, Pressure Drop, and Condensation Heat Transfer in Annular Flow

Конденсация Внутри Гладких Горизонтальных Труб. Сравнение Теоретических Решений И Экспериментальных Данных

Contact Info

Product

Resources

About