Change search
Link to record
Permanent link

Direct link
BETA
Lundqvist, Petter
Publications (2 of 2) Show all publications
Lundqvist, P., Risberg, M. & Westerlund, L. (2019). Air heating system design for a sub-Arctic climate using a CFD technique. Building and Environment, 160, Article ID 106164.
Open this publication in new window or tab >>Air heating system design for a sub-Arctic climate using a CFD technique
2019 (English)In: Building and Environment, ISSN 0360-1323, E-ISSN 1873-684X, Vol. 160, article id 106164Article in journal (Refereed) Published
Abstract [en]

The thermal comfort in a residential building equipped with an air heating system and located in a sub-Arctic region was investigated with computational fluid dynamics (CFD) software. The predicted percentage of dissatisfied (PPD) was used to identify flaws with the heating system during winter conditions. New scenarios were simulated and compared to each other to see potential improvements of the thermal indoor climate. Comparison was done by combining the discomfort spaces inside rooms, the level of the discomfort and the time spent in these spaces. The discomfort covered 8–38% of the interior volume depending on the test case. The results provide the necessary means to create a satisfactory thermal indoor climate if an air heating system is to be utilized in sub-Arctic regions during the winter. The correct heat demand for each floor and appropriate placement of the supply devices are required. Adding air transfer units or grilles in rooms from which exhaust air is removed further improves the comfort. The results also show the strength of using CFD technique when investigating the indoor discomfort with PPD, and how a fair assessment can be done by combining the PPD with time.

Place, publisher, year, edition, pages
Elsevier, 2019
Keywords
Air heating, CFD, Cold climate, PPD, Sub-Arctic climate, Thermal comfort
National Category
Energy Engineering
Research subject
Energy Engineering
Identifiers
urn:nbn:se:ltu:diva-75062 (URN)10.1016/j.buildenv.2019.106164 (DOI)000474204100002 ()2-s2.0-85066465960 (Scopus ID)
Note

Validerad;2019;Nivå 2;2019-06-27 (johcin)

Available from: 2019-06-27 Created: 2019-06-27 Last updated: 2019-08-16Bibliographically approved
Imai, A., Hardi, H., Lundqvist, P., Furusjö, E., Kirtania, K., Karagöz, S., . . . Yoshikawa, K. (2018). Alkali-catalyzed hydrothermal treatment of sawdust for production of a potential feedstock for catalytic gasification. Applied Energy, 231, 594-599
Open this publication in new window or tab >>Alkali-catalyzed hydrothermal treatment of sawdust for production of a potential feedstock for catalytic gasification
Show others...
2018 (English)In: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 231, p. 594-599Article in journal (Refereed) Published
Abstract [en]

This study investigates the effects of reaction temperature and catalyst loading on product yields and fuel properties of produced slurry during the alkali catalyzed hydrothermal treatment (HTT) of pine sawdust. The yield of the liquid fraction, or the aqueous product (AP), at process temperatures of 180–260 °C obtained after solid/liquid separation of the slurry ranged from 11.1 to 34.3 wt% on a dry, ash free basis. The fuel quality of the produced slurry, such as the elemental composition and the higher heating value (HHV), was mainly affected by the catalyst loading. An increase in the catalyst loading caused the ash content to increase. Although the increase in temperature leads to a higher liquid fraction in the slurry making it more homogeneous, its contribution to the elemental composition of the whole slurry was limited. HHV of the produced slurry ranged from 12.0 to 16.4 MJ/kg. These values are comparable to that of black liquor (BL), which has previously been shown to be a promising feedstock for gasification in a pilot scale entrained flow gasifier. These results imply the possibility of a fuel switch from BL to the HTT slurry for entrained flow gasification though its gasification reactivity and conversion characteristics must be investigated further.

Place, publisher, year, edition, pages
Elsevier, 2018
Keywords
Biomass, Hydrothermal treatment, Alkali catalyst, Gasification, Slurry
National Category
Energy Engineering
Research subject
Energy Engineering
Identifiers
urn:nbn:se:ltu:diva-71008 (URN)10.1016/j.apenergy.2018.09.150 (DOI)000452345400045 ()2-s2.0-85053770126 (Scopus ID)
Note

Validerad;2018;Nivå 2;2018-09-27 (svasva)

Available from: 2018-09-27 Created: 2018-09-27 Last updated: 2019-02-13Bibliographically approved
Organisations

Search in DiVA

Show all publications