Recent HTRI News

Obtaining viscosity measurements at elevated temperatures and pressures is challenging. HTRI evaluated several viscosity correlations to determine the best model for hydrocarbons. We also examined a viscosity-density correlation using limited density data. From the initial evaluation, the Walther model proved to be the most promising for extrapolation, predicting viscosity within ±30%...
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Download Case Study PDF SUMMARY A fabrication company thermally re-rated two existing disk-and-doughnut heat exchangers for new process conditions at their acid plant. HTRI conducted research that improved their understanding and ability to model disk-and-doughnut heat exchangers. THE CHALLENGE Analyze heat exchanger performance Assess the potential for excessive vibration Flow pattern...
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Artificial neural networks (ANNs) allow the solution of hard problems such as  determining important parameters affecting crude oil fouling analyzing operating data to troubleshoot heat exchangers developing correlations through multivariate nonlinear regression of complex data To evaluate a neural network model for heat transfer coefficients, we used a multilayer, feed-forward ANN...
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This report documents the revised methods in Xist 8 for predicting the gravity-controlled condensate heat transfer coefficient on horizontal tube bundles. Reformulation of the relevant equations using the local condensate Reynolds number on an element of the tube bundle facilitates exploitation of the Xist 3D incremental structure more effectively than was...
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Ashley Simmons, Engineer, Technical Support Each heat exchanger has unique requirements due to process constraints, site limitations, or cost concerns. The fundamentals of good design apply to every variety of exchanger. The primary goal of every designer is to optimize exchanger design for the most effective heat transfer possible. One of...
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Brandon White, Test Engineer Air-cooled heat exchangers are one of the most widely used types of heat exchangers. At times, they can experience two-phase flow separation and flow maldistribution inside their header boxes, potentially reducing process heat transfer.At HTRI’s Research & Technology Center, we are currently working on a project to...
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This report summarizes HTRI data on vertical tubeside boiling, highlighting the shortcomings of current methods in accurately predicting tubeside pressure drop and heat transfer at low mass velocities. Improvements to the liquid holdup model and a warning message for thermal prediction close to turndown conditions are also discussed. When implemented in...
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What you can expect from method changes in Version 8.2 Xist® window pressure drop models Xist 8.1 has two different models of window pressure drop for single-segmental baffles, depending on baffle cut and baffle spacing. The original model in S-SS-3-1 was developed for single-segmental baffles. A subsequent model, reported in S-SS-3-4,...
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Considered to be the most advanced thermal process design and simulation software, Xchanger Suite designs, rates, and simulates a variety of heat transfer equipment. All Xchanger Suite components are highly flexible, allowing rigorous specification of the exchanger geometry. Xchanger Suite 8.2 is available for licensed users on the Downloads page until...
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Thermosiphon reboilers often pose challenges for column operations in refineries and chemical processing plants. Some challenges are related to turndown, when reboiler circulation rates or duties are lower than design conditions. The process industry uses various checklists and criteria, though most guidelines have little to no validating data backing them up....
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