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Cost optimisation of a flexible heat exchanger network with fluctuation probability using break-even analysis

Hafizan, A. M. and Alwi, S. R. W. and Manan, Z. A. and Klemes, J. J. and Hamid, M. K. A. (2019) Cost optimisation of a flexible heat exchanger network with fluctuation probability using break-even analysis. Chemical Engineering Transactions, 76 . pp. 403-408. ISSN 2283-9216


Official URL: http://www.dx.doi.org/10.3303/CET1976068


Heat exchanger network (HEN) which is designed to achieve the maximum energy recovery (MER) involves the integration and interactions of multiple process streams. Small disturbances on one stream can affect other connecting streams. In order to manage these disturbances, the process to process and utility heat exchangers with bypass streams installation are typically overdesigned. However, overdesign also means higher capital investment. This study presents the cost optimisation of flexible MER HEN design which considers the fluctuation probability using break-even analysis. Data were extracted for the Pinch study and assessment for flexibility and MER was performed. The MER heat exchanger maximum size (MER-HEM) is able to handle the most critical supply temperature fluctuations while minimising the utility consumption. The overdesign factor can affect the total annualised cost at a certain probability of fluctuation occurrence. Thus, the break-even analysis of the MER-HEM is performed to determine the probability that resulted in high savings of total annualised cost. Two Scenarios (A and B) with different fluctuation probabilities were used to demonstrate the methodology. Application of the proposed methodology on an Illustrative Case Study shows that, for the fluctuation at hot stream H1, the MER-HEM gives the optimum annualised total cost for Scenario A with additional savings of 10 %. For Scenario B, the MER heat exchanger original size (MER-HEO) is the optimum, giving an additional savings of 4 %. For cold stream C1, the MER-HEO is the optimum for Scenario A, giving an extra savings of 4 % whereas the MER-HEM is the optimum for Scenario B, yielding an extra savings of 9 %.

Item Type:Article
Uncontrolled Keywords:maximum energy recovery (MER), heat exchanger
Subjects:T Technology > TP Chemical technology
Divisions:Chemical and Energy Engineering
ID Code:89633
Deposited By: Narimah Nawil
Deposited On:09 Feb 2021 13:01
Last Modified:09 Feb 2021 13:01

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