Coiled Heat Exchanger with Small Radius Bent Tubes for Controlled Heat Treatment of High Viscosity Waxy Oil

Abstract

The necessity of using the controlled heat treatment technology of oil instead of «hot pumping» is substantiated. A number of advantages of the “cold” transportation of oil are presented, as well as the main tasks that need to be solved for the successful usage of the above technology at the trunk oil pipelines. The main drawbacks of the heat exchanging equipment used at the heating and pumping stations of trunk pipelines for non-Newtonian solidifying waxy oils. Particular attention is paid to deposition and accumulation of wax in the flowing part of the equipment as well as the possibility of their safe quickly cleaning. The use of domestic twisted steel heat exchangers based on small radius bent tube is proposed. Constructive advantages of the proposed twisted heat exchangers are compared with the traditionally used equipment - shell-and-tube exchangers with horizontal and U-shaped arrangement of pipes, fully-welded plate heat exchangers, as well as finning air cooling units. For comparison, such technical and economic indicators as heat transfer rate, per surface area of heat exchange, complexity of operation, maintenance and repair, reliability and structural strength under cyclic loads in difficult thermobaric conditions are adopted. The issues of using twisted steel heat exchangers based on small radius bent tubes at trunk pipelines objects are considered taking into account successful experience of application in other industries.

About Complex Oil Flow Curve Form in Anomaly Viscosity Low Temperatures and Shear Rates Conditions

“…The fact that effective implementation of the heat treatment technology is impossible because of the relatively low technology level and reliability indicators of exchanger equipment has also become the reason for the ineffectiveness of widely introduced methods of chemical treatment because of inadequate temperatures of oil preheating when adding pour point depressants [6,7,8].…”

CFD Modeling of Heat Exchanger with Small Bent Radius Coils Using Porous Media Model

“…One option to make the heat exchanger's design more compact is the use of close-packed with small bend radius coils (SBRC). Such designs [1] have been applied in various industries. However, heat transfer in the complex geometry of a heat exchanger's annular space (Figure 1) cannot be described by simple one-dimensional cases and dependencies; for example, formulas for the heat transfer coefficient of a transverse flow around a tube bundle must consider the three-dimensional spatial structure of the heat exchange surface.…”