(28b) Two-Phase Pipe Side Process Model for Fired Heaters

The objective of this project was to develop multiphase heat transfer and pipe flow analytical methodologies that are applicable to large diameter pipes and U-bends found in refinery heaters. The technical approach was implemented in three phases. Phase I focused on identifying and evaluating multiphase correlations to predict process side flow regimes, pressure drop, and heat transfer coefficient applicable to fired heaters. This involved an extensive literature survey, systematic evaluation of literature correlations for applicability to process heaters, and selection of the most promising correlations for developing and comparative validation of the process model in Phase II. The Phase II tasks included 1) the development of a process model for horizontal pipe box-type and vertical pipe cylindrical heaters; 2) comparative analysis of the literature correlation to select those applicable to fired heaters; 3) comparative analysis of the process model with the API530 correlation for TMT prediction. Phase III is being pursued to incorporate the threshold fouling model into the process model.