A new computational procedure for refrigerant condensation inside herringbone-type Brazed Plate Heat Exchangers. (March 2015)

• Record Type: Journal Article
• Authors: Longo, Giovanni A.; Righetti, Giulia; Zilio, Claudio
• Is Part Of: International journal of heat and mass transfer. Volume 82(2015:Mar.)
• Page Start: 530
• Page End: 536
• Publication Date: 2015-03
• Subjects: Condensation -- BPHE -- Refrigerant -- Heat transfer coefficient -- Super-heating -- Gravity-dominated -- Forced convection condensation; Heat -- Transmission -- Periodicals; Mass transfer -- Periodicals; Chaleur -- Transmission -- Périodiques; Transfert de masse -- Périodiques; Electronic journals; 621.4022
• DOI: 10.1016/j.ijheatmasstransfer.2014.11.032
• Languages: English
• ISSNs: 0017-9310

Abstract

Abstract: This paper presents a new computational procedure for refrigerant condensation inside herringbone-type Brazed Plate Heat Exchanger (BPHE). A transition point between gravity controlled and forced convection condensation was found for an equivalent Reynolds number around 1600. At low equivalent Reynolds number (<1600) the heat transfer coefficients are not dependent on mass flux and are well predicted by a simple model based on the Nusselt (1916) equation for vertical surface. For higher equivalent Reynolds number (>1600) the heat transfer coefficients depend on mass flux and condensate drainage is controlled by the combined actions of gravity and vapour shear. A new model was developed for predicting the heat transfer coefficients in the forced convection condensation region. This new model was also applied to super-heated vapour condensation by using the equation of Webb (1998) to account for super-heating effects. The new computational procedure was compared against data from the literature: the mean absolute percentage deviation between experimental and calculated heat transfer coefficients was lower than 16%.