Development of a low cost design toolkit for sizing air-cooled heat exchangers using open source heat transfer correlations

  • Ugonna Chidera Mbaezue

Student thesis: Master's Thesis

Abstract

The exorbitant costs associated with heat exchanger design software e.g. ASPEN EDR, HTRI X-Suite etc., means that most engineering firms especially SMEs, struggle to purchase and use these tools for in-house design purposes. Therefore, heat exchanger design for these engineering firms is dependent on charts, graphs and 'passed down' knowledge. Unfortunately in most cases, the accuracy of these design data sources cannot be verified which means that every heat exchanger designed, is not sized correctly to deliver the heat duty required.The aim of this project was to build a low cost toolkit capable of designing and rating Circular - Fin, Tube-in-Plate Fin and Plain Tube Heat Exchangers air-cooled heat exchangers.Heat transfer correlations were obtained from publicly available data and the validation process involved designing air-cooled heat exchangers using these correlations. Thereafter, the design process was repeated using the industry standard software, ASPEN Exchanger Design & Rating (EDR). The results were then compared. The outcome indicated that when geometrical characteristics and operating conditions stayed within the boundaries specified by the open source correlations, the largest deviation will occur in the Tube-in-Plate heat exchanger with an over-prediction of 14% of the area ratio (Gas side vs. Fluid side of the heat exchanger) when compared with the ASPEN EDR results. The Plain Tube heat exchanger showed a 7.5% over-prediction for the staggered tube layout and an 8% over-prediction for the inline tube layout. The Circular-Fin heat exchanger gave the best result with a 6% over-prediction for the compared area ratios.Based on these results, the toolkit was developed using the Excel Visual Basic for Applications (VBA) programming language. The NIST Reference fluid Properties (REFPROP) database was used to obtain the thermophysical properties of the interacting fluids and was also integrated into the toolkit using the VBA programming language.
Date of Award4 Oct 2019
Original languageEnglish
Awarding Institution
  • University Of Strathclyde
SupervisorDavid Nash (Supervisor) & William Dempster (Supervisor)

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