A New Numerical Approach for Exergy Targets and Losses Determination in Sub-Ambient Processes

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216305%3A26210%2F17%3APU127169" target="_blank" >RIV/00216305:26210/17:PU127169 - isvavai.cz</a>

Výsledek na webu

<a href="http://dx.doi.org/10.3303/CET1761202" target="_blank" >http://dx.doi.org/10.3303/CET1761202</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.3303/CET1761202" target="_blank" >10.3303/CET1761202</a>

Jazyk výsledku

angličtina

Název v původním jazyce

A New Numerical Approach for Exergy Targets and Losses Determination in Sub-Ambient Processes

Popis výsledku v původním jazyce

Sub-ambient processes such as a refrigeration system are a highly energy intensive area in chemical industries. Refrigeration systems require a high level of process cooling using a combination of compression and expansion operations. It is, therefore, crucial to optimise heat transfer between the utility system and the process streams including the placement of compression and expansion operations to minimise the exergy losses and work as much as possible. This paper demonstrates how heat integration tools such as Pinch Analysis and Exergy Analysis can be applied to determine exergy losses and exergy targets for sub-ambient processes. In this study, a numerical approach, the Exergy Problem Table Algorithm (Ex-PTA), is proposed as an improved method compared to the graphical method based on the Extended Pinch Analysis and Design (ExPAnD) methodology. The methodology is applied to a literature case study of a refrigeration system to prove its validity. For the new numerical method, the minimum exergy requirement above the Exergy Pinch is 2.67 kW, while the maximum exergy rejection below the Exergy Pinch is 1.33 kW. The result shows that the total exergy loss for the process is 4.74 kW. In contrast, the maximum exergy rejection and minimum exergy requirement obtained in ExPAnD are 0.46 kW and 5.38 kW while the total exergy loss is 6.72 kW. These new targets assume so-called horizontal heat transfer is allowed between process and utility streams, whereas the ExPAnD method assumes vertical heat transfer between process and utility and, therefore, results in less optimistic targets.

Název v anglickém jazyce

A New Numerical Approach for Exergy Targets and Losses Determination in Sub-Ambient Processes

Popis výsledku anglicky

Sub-ambient processes such as a refrigeration system are a highly energy intensive area in chemical industries. Refrigeration systems require a high level of process cooling using a combination of compression and expansion operations. It is, therefore, crucial to optimise heat transfer between the utility system and the process streams including the placement of compression and expansion operations to minimise the exergy losses and work as much as possible. This paper demonstrates how heat integration tools such as Pinch Analysis and Exergy Analysis can be applied to determine exergy losses and exergy targets for sub-ambient processes. In this study, a numerical approach, the Exergy Problem Table Algorithm (Ex-PTA), is proposed as an improved method compared to the graphical method based on the Extended Pinch Analysis and Design (ExPAnD) methodology. The methodology is applied to a literature case study of a refrigeration system to prove its validity. For the new numerical method, the minimum exergy requirement above the Exergy Pinch is 2.67 kW, while the maximum exergy rejection below the Exergy Pinch is 1.33 kW. The result shows that the total exergy loss for the process is 4.74 kW. In contrast, the maximum exergy rejection and minimum exergy requirement obtained in ExPAnD are 0.46 kW and 5.38 kW while the total exergy loss is 6.72 kW. These new targets assume so-called horizontal heat transfer is allowed between process and utility streams, whereas the ExPAnD method assumes vertical heat transfer between process and utility and, therefore, results in less optimistic targets.

Druh

D - Stať ve sborníku

CEP obor

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OECD FORD obor

20402 - Chemical process engineering

Projekt

<a href="/cs/project/EF15_003%2F0000456" target="_blank" >EF15_003/0000456: Laboratoř integrace procesů pro trvalou udržitelnost</a><br>

Návaznosti

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Rok uplatnění

2017

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název statě ve sborníku

Chemical Engineering Transactions

ISBN

978-88-95608-51-8

ISSN

2283-9216

e-ISSN

—

Počet stran výsledku

6

Strana od-do

1225-1230

Název nakladatele

Italian Association of Chemical Engineering - AIDIC

Místo vydání

Neuveden

Místo konání akce

Tianjin

Datum konání akce

21. 8. 2017

Typ akce podle státní příslušnosti

WRD - Celosvětová akce

Kód UT WoS článku

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