Refinery systems and condensation heat transfer in heat exchangers

Distillation of crude oil is a process consisting of evaporation and condensation phenomena. The petroleum based liquid fuels are obtained via condensing the vapor of crude oil at different temperatures. Condensation occurs when the vapor particles contact to a cooler surface than the vapor itself. To keep the temperature of the surface at a constant value, the surface is cooled with a cooling water circulation. The heat exchangers involving large condensation surface inside itself are named as condenser. Condensers are designed at very different configurations. In a condenser having large enough capacity the vapor condensers at the inner or outer surface of a circular pipe.In this thesis a comprehensive literature review of the mathematical models devised for condensation is carried out and an application to the condensation of diesel fuel vapor is made. The simplest mathematical model is the Nusselt approximation where it is assumed that the vapor condenses on an isothermal surface and moves with the effect of gravity. In elaborated mathematical models the vapor shear, temperature variation of the surface on which the condensation occurs, acceleracting motion on the condensate, pressure variation with in the condensate, eddy viscosity, eddy heat transfer, turbulent flow on the condesate and effects of noncondesable gasses are taken into the consideration. In this thesis the results obtained from the Nicol-Wallace model, which is a elaborated model, is compared to the result obtained from the Nusselt model.Key Words : Condensation, Vapour Shear, Condenser, Refinery