Management of cleaning types and schedules in refinery heat exchangers

Energy recovery and production in oil refinery pre-heat trains are greatly affected by fouling, the progressive build-up of unwanted material on the heat exchanger surfaces. Even when good design practices, operation or mitigation measures are in place, fouling cannot be completely eliminated in most situations. As a result, heat exchangers have to be periodically taken out of operation for cleaning. Traditional mechanical cleaning methods (e.g. hydro-blast) usually remove the whole deposit while chemical cleaning methods represent a less expensive option whose effectiveness depends on a number of factors (e.g. choice of chemicals, deposits composition and ageing, etc.). In this paper a detailed dynamic distributed model of shell and tube exchangers undergoing fouling has been used to simulate different cleaning schedules involving mechanical and chemical operations and assess their economic impact.Papers presented to the 12th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, Costa de Sol, Spain on 11-13 July 2016