Predictive Performance Assessment of Heat Exchangers for Proactive Remediation

Efficiency of industrial heat exchangers degrades over time as a result of deposition of the extraneous matter present in the heat-exchanging medium. Many times the degradation is rapid enough to take a heavy toll on the overall plant economy. It is therefore important to keep a closer watch on heat exchanger performance so that a suitable corrective action can be initiated the moment any abnormality is detected. While most plants monitor their exchangers to some degree, ability to effect real and sustainable improvements requires four components: (1) near-real time detection capability; (2) an early warning system (3) capability to diagnose the cause of fouling; and (4) right expertise to treat the cause in order to slow or reverse the degradation. CHeX² is a comprehensive tool that we have developed, which monitors, predicts, and diagnoses heat exchanger performance. This tool has been designed to cover a wide range of heat transfer equipments namely simple heat exchangers, condensers and partial condensers with both the shell and tube-side condensation. The unique features of this advanced tool include: numerous data cleaning steps to enhance data quality and isolate a net fouling trend, an adaptive model which learns from the past to predict performance three years in advance, and knowledge-based diagnostics which identify the probable cause(s) of fouling and recommend corrective actions. A trained field engineer takes the final control action by adjusting the fouling treatment. The scope of the current paper includes only the detection and prediction features. To date, CHeX has been validated at three chemical processing plants, for fourteen exchangers. Selected case studies shall be presented to demonstrate the power of its algorithms over traditional calculations.