Parameter study on the performance of dropwise condensation

An experimental and theoretical study on the concept of dropwise condensation

“…where, t is the time taken by the large drop to sweep the substrate surface and A d is the actual area of swept region due to large drops falling and can be expressed as [30],…”

Nanotechnology for Advanced Nuclear Thermal-Hydraulics and Safety: Boiling and Condensation

“…That is, DWC is speculated to be the most effective condensation process. For instance, DWC was reported to be up to 30 times more effective than FWC when tested with Langmuir-Blodgett treated surfaces [80,81], and 5~20 times better when a DWC promotion surface is used [82]. These previous works imply that the performance of a heat rejection system will be improved and the system size can be reduced if DWC is facilitated with the system.…”

“…They measured dropwise condensation heat flux on circular tube walls and reported that the condensation heat transfer rate was increased by a factor of 3 to 1.8 times depending on the operating conditions. Kananeh et al [112] also achieved stable dropwise condensation of saturated steam on a horizontal stainless- [82] steel tube bundle of nine tubes implanted with nitrogen ions. They reported the overall heat transfer coefficient of the implanted tube bundle was increased by 1.12 times compared to that of an unimplanted bundle.…”

“…Some researchers have investigated dropwise condensation of diamond-like-coatings (DLCs) and ionimplanted coatings on aluminum and copper plates [83,110,111,112]. Koch et al [82] reported that the dropwise condensation heat transfer rate increased with an increase in the contact angle, as shown in Fig. 21.…”

Effect of Drop Shape on Heat Transfer During Dropwise Condensation Underneath Inclined Surfaces

“…The subject is of interest because of specific features of this mode of condensation. The heat transfer coefficient during dropwise condensation can be quite high, for example, up to 30 times greater than the filmwise mode, when tested with Langmuir-Blodgett surfaces (Zhao et al, 1996;Koch et al, 1998;Rose, 2002), and 5-20 times better when a promoter layer is used (Koch et al, 1998). Therefore, dropwise condensation has the potential to diminish the size of heat exchange equipment used in thermal and nuclear power plants.…”