Simultaneous Synthesis of Heat-Integrated Water Network with the Two-Step Approach

Determining the optimal design of a Heat-Integrated Water Network (HIWN) is a complex task due to the existence of highly nonlinear relationships when considering concentrations, mass and heat balances. Due to that complexity, the solution is usually obtained by a sequential approach. In this approa...

Full description

Bibliographic Details
Main Authors: Andreja Nemet, Nidret Ibric, Miloš Bogataj, Elvis Ahmetovic, Zdravko Kravanja
Format: Article
Language:English
Published: AIDIC Servizi S.r.l. 2022-09-01
Series:Chemical Engineering Transactions
Online Access:https://www.cetjournal.it/index.php/cet/article/view/12782
_version_ 1811302508116574208
author Andreja Nemet
Nidret Ibric
Miloš Bogataj
Elvis Ahmetovic
Zdravko Kravanja
author_facet Andreja Nemet
Nidret Ibric
Miloš Bogataj
Elvis Ahmetovic
Zdravko Kravanja
author_sort Andreja Nemet
collection DOAJ
description Determining the optimal design of a Heat-Integrated Water Network (HIWN) is a complex task due to the existence of highly nonlinear relationships when considering concentrations, mass and heat balances. Due to that complexity, the solution is usually obtained by a sequential approach. In this approach, the minimum fresh water and utility consumption is firstly determined. Then, the exact design of the HIWN is synthesised with the fixed minimum fresh water and utility consumption. Another way to obtain the HIWN design is by using a simultaneous approach. However, such a model can be highly nonlinear requiring the application of a special solution strategy. In this work, a two-step approach was developed and applied. In the first step, a targeting Mixed-Integer Nonlinear Programming (MINLP) model with a high share of linearity was applied estimating also the HEN investment. In this way, the solutions are steered towards an optimal solution by establishing appropriate trade-offs between investment and operating costs during the targeting step. Based on the results of the first step, a reduced superstructure and MINLP model are used in the second design step to select promising matches for heat exchangers. By excluding the non-promising matches that previously led to an unnecessary increase in the complexity of the synthesis model, the second step MINLP model performs much better and enables synthesizing the entire HIWN simultaneously. The aim of this work was to verify whether the two-step approach is suitable for solving the HIWN problem. The obtained solution for case study considered in this work indicated the applicability of the proposed approach, which will be also applied in further research on large-scale HIWN problems.
first_indexed 2024-04-13T07:29:23Z
format Article
id doaj.art-958e607447ee486cb1aede3ec01df0ab
institution Directory Open Access Journal
issn 2283-9216
language English
last_indexed 2024-04-13T07:29:23Z
publishDate 2022-09-01
publisher AIDIC Servizi S.r.l.
record_format Article
series Chemical Engineering Transactions
spelling doaj.art-958e607447ee486cb1aede3ec01df0ab2022-12-22T02:56:23ZengAIDIC Servizi S.r.l.Chemical Engineering Transactions2283-92162022-09-019410.3303/CET2294225Simultaneous Synthesis of Heat-Integrated Water Network with the Two-Step ApproachAndreja NemetNidret IbricMiloš BogatajElvis AhmetovicZdravko KravanjaDetermining the optimal design of a Heat-Integrated Water Network (HIWN) is a complex task due to the existence of highly nonlinear relationships when considering concentrations, mass and heat balances. Due to that complexity, the solution is usually obtained by a sequential approach. In this approach, the minimum fresh water and utility consumption is firstly determined. Then, the exact design of the HIWN is synthesised with the fixed minimum fresh water and utility consumption. Another way to obtain the HIWN design is by using a simultaneous approach. However, such a model can be highly nonlinear requiring the application of a special solution strategy. In this work, a two-step approach was developed and applied. In the first step, a targeting Mixed-Integer Nonlinear Programming (MINLP) model with a high share of linearity was applied estimating also the HEN investment. In this way, the solutions are steered towards an optimal solution by establishing appropriate trade-offs between investment and operating costs during the targeting step. Based on the results of the first step, a reduced superstructure and MINLP model are used in the second design step to select promising matches for heat exchangers. By excluding the non-promising matches that previously led to an unnecessary increase in the complexity of the synthesis model, the second step MINLP model performs much better and enables synthesizing the entire HIWN simultaneously. The aim of this work was to verify whether the two-step approach is suitable for solving the HIWN problem. The obtained solution for case study considered in this work indicated the applicability of the proposed approach, which will be also applied in further research on large-scale HIWN problems.https://www.cetjournal.it/index.php/cet/article/view/12782
spellingShingle Andreja Nemet
Nidret Ibric
Miloš Bogataj
Elvis Ahmetovic
Zdravko Kravanja
Simultaneous Synthesis of Heat-Integrated Water Network with the Two-Step Approach
Chemical Engineering Transactions
title Simultaneous Synthesis of Heat-Integrated Water Network with the Two-Step Approach
title_full Simultaneous Synthesis of Heat-Integrated Water Network with the Two-Step Approach
title_fullStr Simultaneous Synthesis of Heat-Integrated Water Network with the Two-Step Approach
title_full_unstemmed Simultaneous Synthesis of Heat-Integrated Water Network with the Two-Step Approach
title_short Simultaneous Synthesis of Heat-Integrated Water Network with the Two-Step Approach
title_sort simultaneous synthesis of heat integrated water network with the two step approach
url https://www.cetjournal.it/index.php/cet/article/view/12782
work_keys_str_mv AT andrejanemet simultaneoussynthesisofheatintegratedwaternetworkwiththetwostepapproach
AT nidretibric simultaneoussynthesisofheatintegratedwaternetworkwiththetwostepapproach
AT milosbogataj simultaneoussynthesisofheatintegratedwaternetworkwiththetwostepapproach
AT elvisahmetovic simultaneoussynthesisofheatintegratedwaternetworkwiththetwostepapproach
AT zdravkokravanja simultaneoussynthesisofheatintegratedwaternetworkwiththetwostepapproach