The heat transfer enhancement technology (HTET) has been developed and widely applied to heat exchanger applications over last decade, such as refrigeration, auto motives, process industry, nuclear reactors, and solar water heaters. Till date, there have been many attempts to reduce the sizes and the costs of the heat exchangers and their energy consumption with the most influential factors being heat transfer coefficients and pressure drops, which generally lead to the incurring of less capital costs.
Heat pipes are two-phase heat transfer devices with high effective thermal conductivity. Due to the high heat transport capacity, heat exchanger with heat pipes has become much smaller than traditional heat exchangers in handling high heat fluxes. With the working fluid in a heat pipe, heat can be absorbed on the evaporator region and transported to the condenser region where the vapor condenses releasing the heat to the cooling media.
The primary aim is to evaluate the effect of different varying diameter ratio on entrance on heat transfer. Increasing diameter ratio on entrance leads to enhancement of heat transfer coefficient. In the present, work attempts are made to enhance the heat transfer rate in heat pipe heat exchangers. A heat pipe heat exchanger with different varying section modeling is done using ANSYS. The CFD simulated results are compared with previous work. Based on the results, increasing diameter ratio on entrance causes the increment of overall heat transfer coefficient which results in the enhancement of heat transfer rate of heat exchanger.