CFD modelling of flue gas particulates in a biomass fired stove with electrostatic precipitation K. Dastoori a , B. Makin a , M. Kolhe b, * ,1 , M. Des-Roseaux c , M. Conneely a a Electronic Engineering and Physics Division, University of Dundee, Dundee DD1 4HN, UK b Faculty of Engineering and Science, University of Agder, N-4879 Grimstad, Norway c Ecole Nationale D’ingenieurs, Du Val De Loire, BP 3410, 41034 Blois cedex, France article info Article history: Received 18 December 2012 Accepted 23 December 2012 Available online 13 January 2013 Keywords: Electrostatic precipitator Biomass combustion CFD modelling of flue gas particulates COMSOL abstract The biomass fired stoves have been used in medium and large scales applications from several years and are utilizing electrostatic precipitator technology. Biomass based technologies are considered as renewable energy source and less harmful to the environment. The combustion of biomass generates a high concentration of flue gas particulates. The most of the flue gas particulates in the exhaust gas can be filtered through an electrostatic precipitator. In this work, a computational fluid dynamic (CFD) model has been developed for analysing the trajectory of particulates in a small scale domestic stove using biomass material. It is considered that electrostatic precipitator is based on an approach where both charging and precipitation of particulates takes place within the same set of electrodes. The precipitator is mounted in a vertical chimney of diameter 180 mm containing a central high voltage corona source. The model is based on biomass combustion models utilising a EulerianeLagrangian reference. The developed CFD model demonstrates the efficiency of the removal of charged particulates of the flue gases and also the interaction of the electric field in a semi turbulent flow together with the combination of the ion wind. Also it includes the effects of space charge within the system. In the modelling, modifications have been made to the grounded cylindrical collector of electrostatic precipitation through a re-design to include a series of inclined baffle plates for improving the particulates’ collection efficiency. Ó 2013 Elsevier B.V. All rights reserved. 1. Introduction Small scale biomass combustion is a considerable source of in- door and outdoor air pollution. The combustion of biomass gen- erates a high concentration of particulate matter emission. Fine particles are strongly associated with human health and especially with cardiovascular diseases, so there is an increasing need for fine particle precipitators to reduce them from small scale/domestic biomass based combustion systems [1]. In this work, a computa- tional fluid dynamic (CFD) model has been developed for analysing the trajectory of particulates in a small scale domestic stove using biomass material. It is considered that electrostatic precipitator is based on an approach where both charging and precipitation of particulates takes place within the same set of electrodes [2]. In this study, to investigate the flue gas particulate trajectories in the biomass fired chimney, a CFD model has been developed through COMSOL Multi-physics package for different physical process by using finite element method. The flue gas particulates trajectories in the biomass combustion stove fitted with electrostatic precipi- tator has been analysed for determining the efficiency, effect of particulates’ size with variation of applied high voltage. Also the effect of corona wind has been included in the modelling, which depends on the mobility of the ions in the flue gases. In the mod- elling, modifications have been made to the grounded cylindrical collector of electrostatic precipitation through a redesign to include a series of inclined baffle plates for improving the particulates’ collection efficiency. 2. Electrostatic precipitator The electrostatic precipitator system for a small scale biomass based combustion furnace is shown in Fig. 1 . It has been considered that a cylindrical type of electrostatic precipitator will be retrofitted inside the biomass stove chimney. The system is based on a central corona wire with a cylindrical grounded collector. The basic prin- ciple of operation of an electrostatic precipitator is that the par- ticulates are passed through a zone of mono-polar ions together * Corresponding author. Tel.: þ47 3723 3293. E-mail addresses: k.dastoori@dundee.ac.uk (K. Dastoori), mohan.l.kolhe@uia.no, kolhe.mohan@gmail.com (M. Kolhe). 1 Prof. Kolhe was formerly with the University of Dundee, UK. Contents lists available at SciVerse ScienceDirect Journal of Electrostatics journal homepage: www.elsevier.com/locate/elstat 0304-3886/$ e see front matter Ó 2013 Elsevier B.V. All rights reserved. http://dx.doi.org/10.1016/j.elstat.2012.12.039 Journal of Electrostatics 71 (2013) 351e356