Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Parametric study of a wastewater heat recovery system for buildings
Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
2019 (English)Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
Abstract [en]

Global efforts makes buildings successively more energy efficient. This results in that the percentage of the total energy in the building that is lost to the sewage system, in the form of hot water, is increasing. The characteristics of the wastewater originating from the urban water cycle makes it an attractive heat source which is relatively unexploited. Wastewater heat recovery (WWHR) systems is a group of systems designed to reduce a buildings use of external energy sources by recovering the heat out of the wastewater before it is let out into the sewage.        

The focus of this report is a parametric study performed on a WWHR system that utilises thermal storage tanks for accumulation of wastewater and a heat pump equipped with heat exchangers for the heat recovery. The studied variables are the amount of energy that the system is able to recover out of the wastewater and the seasonal average COP of the heat pump. The change of these two variables were analysed both as an affect of parameters dependent of system design and on consumption patterns of the residents of the building. The results showed that by properly designing the system the recovery degree can be increased by 31.5 percentage points reaching values above 90 % and the seasonal average COP can be increased by 13.5 % reaching values of 5.13. However, these two variables stands in contrast to each other were maximising one will reduce the other and it is proposed that it is important to take both into account when evaluating a WWHR system. It is also shown that the consumption related parameters have a relatively big effect on the system. The change in recovery degree as a result of these non-controllable parameter is 14 percentage points and the seasonal average COP changes with 4.2 %.        

The system performance as a result of changing the U-value of the heat exchanger connecting the system to the domestic hot water circuit was also analysed. This showed an exponential relation between the U-value and delivered energy from the heat pump. The results showed that an increase of the U-value from 50 W/K to 6000 W/K increased the yearly energy supplied with 37.6 % but an increase from 1000 W/K to 6000 W/K increased the yearly supplied energy with less than 1 %. This result highlights the importance of properly dimensioning the heat exchanger.

Place, publisher, year, edition, pages
2019.
Keywords [en]
Waste water heat recovery, WWHR
National Category
Energy Engineering
Identifiers
URN: urn:nbn:se:umu:diva-160471OAI: oai:DiVA.org:umu-160471DiVA, id: diva2:1327330
External cooperation
Ecoclime
Subject / course
Energiteknik
Educational program
Master of Science Programme in Energy Engineering
Supervisors
Examiners
Available from: 2019-06-19 Created: 2019-06-19 Last updated: 2019-06-19Bibliographically approved

Open Access in DiVA

Parametric study of a wastewater heat recovery system for buildings(5341 kB)21 downloads
File information
File name FULLTEXT01.pdfFile size 5341 kBChecksum SHA-512
8ebb7acf9a37494521046210bce74515327dd22d2a3c5d07028f089de20e0743cf719fea878f4e101000e75d07cac25a48f6c23b9f810a40c439a1dd41c60b14
Type fulltextMimetype application/pdf

By organisation
Department of Applied Physics and Electronics
Energy Engineering

Search outside of DiVA

GoogleGoogle Scholar
Total: 21 downloads
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

urn-nbn

Altmetric score

urn-nbn
Total: 53 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf