Sharif Digital Repository

Heat pipe is a device with several applications in various industries such as electronics cooling, nuclear and renewable technologies. This apparatus transfers heat from a hot source to a cold one. Thermosyphon is a special type of heat pipe that transmits heat using gravitational forces. Although scholars have performed many experiments on thermosyphon, mostly they were about the thermal characteristics of thermosyphon and rarely the hydraulic specifications of thermosyphon have been investigated. But it is clear that these two specifications (thermal, hydraulic) relate to each other closely and detailed study about their interaction may bring out better results. In this thesis, initially a... 

In terms of thermodynamics and heat transfer, heat pipes such as closed two-phase thermosyphon are of great importance in saving energy. In this study, a computational fluid dynamics model for simulation of a thermosyphon heat pipe with two-phase flow including phase change heat transfer was developed. The study has mainly focused on the effects of volume concentrations of Nanoparticles and the operating temperature on the heat transfer performance of the thermosyphon. The analysis was performed to compare heat transfer performance between a solid copper tube and a thermosyphon heat pipe which contained deionized water and graphene oxide(GO)/water Nanofluid as its working fluids. Based on a... 

In petrochemical, Process condensate is mixtures of dissolved gasses and water. Process condensate striper tower is a physical separation equipment where dissolved gasses remove from water by saturated steam. The Process condensate feed is introduced at the top of the column and the steam input is located at the bottom. When the process condensate enters the stripper tower, it comes down the tower also when the steam enters the tower, it goes up, because there is packing portion in the stripper tower and two streams are countercurrent, as result contact between steam and process condensate, a lot of dissolved gases vapors and exits with steam from top of tower. After leaving the tower, the... 

Heat pipe is a heat transfer device that may have a thermal conductance hundreds of times higher than that of copper. Currently, heat pipes have been used in numerous applications including satellite thermal management, energy systems for energy recovery and energy conversion, and electronics cooling, particularly in laptop and desktop computers. In this thesis, a new application of the heat pipe in an automotive engine is introduced. In this application, heat pipes are incorporated into the radiator of the automotive engine for more efficient heat transfer. In particular, the employment of the heat pipes would allow the gravity to be used as the driving force for the liquid... 

Due to the development of heat pipes in different industries and special characteristics of heat pipes, in this study, it has been tried using computational fluid dynamics (CFD) method to simulate a heat pipe heat exchanger that can be a replacement for the normal radiator. The experimental model of this heat exchanger has been tested at past studies and the numerical simulation of the heat exchanger will analyze at present study. The use of heat pipe in the car radiator has many advantages such as reducing fluid pressure drop through the heat exchanger, high reliability due to the particular structure of the heat exchanger (individual performance of each heat pipe) and improving heat...