Dam-Johansen, Kim

Hansen, Brian Brun

Illerup, Jytte Boll

Lin, Weigang

Nickelsen, Joachim

Online Research Database In Technology

                       General rights Copyright and moral rights for the publications made accessible in the public portal are retained by the authors and/or other copyright owners and it is a condition of accessing publications that users recognise and abide by the legal requirements associated with these rights.  • Users may download and print one copy of any publication from the public portal for the purpose of private study or research. • You may not further distribute the material or use it for any profit-making activity or commercial gain • You may freely distribute the URL identifying the publication in the public portal   If you believe that this document breaches copyright please contact us providing details, and we will remove access to the work immediately and investigate your claim.     Downloaded from orbit.dtu.dk on: Jan 01, 2018Advanced combustion control for a wood log stove, Expert workshop - Highly Efficientand Clean Wood Log StovesIllerup, Jytte Boll; Hansen, Brian Brun; Lin, Weigang; Nickelsen, Joachim; Dam-Johansen, KimPublication date:2015Document VersionPeer reviewed versionLink back to DTU OrbitCitation (APA):Illerup, J. B., Hansen, B. B., Lin, W., Nickelsen, J., & Dam-Johansen, K. (2015). Advanced combustion controlfor a wood log stove, Expert workshop - Highly Efficient and Clean Wood Log Stoves [Sound/Visual production(digital)]. Expert workshop - Highly Efficient and Clean Wood Log Stoves, Berlin, Germany, 29/10/2015Advanced combustion control for a wood log stove Expert workshop - Highly Efficient and Clean Wood Log Stoves Berlin 29 October 2015   Jytte Boll Illerup Brian Brun Hansen  Weigang Lin Joachim Nickelsen Kim Dam-Johansen 2 DTU Chemical Engineering,  Technical University of Denmark Intelligent Heat System  High-energy  efficient wood stoves with low missions • Collaboration between HWAM A/S and DTU Chemical Engineering • Periode 2011 – 2015 • EUDP - project    (Energy Technology Development and Demonstration Program)  Development of a new automatically controlled wood stove with: • High energy efficiency • Reduced emissions (CO, particles etc.)  • High comfort for the wood stove users   3 DTU Chemical Engineering,  Technical University of Denmark Main results •A new advanced control system has been developed based on experiments conducted at  experimental facilities at HWAM og DTU Chemical Engineering   •HWAM has launched an automatically controlled modern wood stove on the market  • Field and laboratory tests has shown reduced emissions and higher efficiency for stoves with the control system    - and high comfort for the wood stove users   4 DTU Chemical Engineering,  Technical University of Denmark Content  •Background for the project –why an automatic control system?  •Concept of the automatically controlled wood stove  •Our results from –Field tests –Experiments at the wood stove set-up at DTU Chemical Engineering  5 DTU Chemical Engineering,  Technical University of Denmark Regulation and legislation Approval of Wood stoves Eff.  (%) CO (mg/ Nm3) PM (mg/Nm3) PM (g/kg) OGC (mg/Nm3)  Danish Statutory of order - <40 <5 <150 Danish Statutory of order (from 2017) - <30 <4 <120 Swan label (optional) ≥76 ≤1250 <3 <100 Swan label (from 2017) ≥76 ≤1250 <2 <100 New wood stoves are approved according to national and European standards.   Standards: The emissions can be much higher when the stoves are used by ordinary wood stove users 6 DTU Chemical Engineering,  Technical University of Denmark Challenges The emission level can be high due to challenging conditions:   • batch firing in small combustion chambers  •wide range of various wood types and wood log sizes  • combustion air flows and fuel loads are manually controlled    Difficult to achieve an optimal combustion  7 DTU Chemical Engineering,  Technical University of Denmark Improved technologies  Modern stoves with air staging:  Three combustion air inlets:  • Primary air at the bottom (ignition)  •Secondary air at the top of the front window (air-wash, second combustion)  • Tertiary air at the back wall (high temperature gas combustion)  However, well-designed stoves can also cause  high emissions and low efficiency 8 DTU Chemical Engineering,  Technical University of Denmark Field tests – measurements at stoves in private homes    Measured 1 week: - Existing (modern) stove - Automatically controlled wood stove - O2, CO2, CO, flue gas temp. -   Amount of wood - Temp. in– and outdoor   It is difficult to control the combustion air flows manually in an optimal way.   Field tests in six private homes 9 DTU Chemical Engineering,  Technical University of Denmark Lack of combustion air in the flame  phase and too much air in the char combustion phase Manually controlled wood stove – 1 Ignition Flame Char combustion One combustion cycle 10 DTU Chemical Engineering,  Technical University of Denmark High excess air and temperature in both the flame phase and the char combustion phase  Manually controlled wood stove – 2 Four combustion cycles A large potential for improving the combustion process  by optimizing the combustion air flows 11 DTU Chemical Engineering,  Technical University of Denmark Automatically controlled wood stove Modern wood stove + Air box (3 motor-controlled valves and a software program) + Process control (the process parameters are the O2 concentration and the temperature in the flue gas) + Remote control to starts the combustion and set the room temperature 12 DTU Chemical Engineering,  Technical University of Denmark Control of the air supply   The three air inlets are automatically controlled by   • a software program based on the definition of five combustion phases   •  and the process parameters – measured  temperature and O2 in the flue gas    13 DTU Chemical Engineering,  Technical University of Denmark   Software – overall concept Phase 1 (Ignition) Phase 2 (Flame) Phase 4 (Shut down) Phase 3 (Char combustion) • Primary • Secondary • Tertiary   Regulation: None Phase 0 (Cold stove) • Primary • Secondary • Tertiary   Regulation:  Temp. and O2 • Primary • Secondary • Tertiary   Regulation:  Temp. and O2 • Primary • Secondary • Tertiary   Regulation:  Temp. and O2 • Primary • Secondary • Tertiary   Regulation:  None Phase Change:  Temperature,   O2 and air flow –  in combination  14 DTU Chemical Engineering,  Technical University of Denmark Standard combustion cycle     051015200,010,020,030,040,050,060,070,080,090,0100,0110,0100 150 200 250 300 350 400 450 500O2 %  ppm CO / °C / Fase CO %*100 T10 outlet temp / 6 Fase O2 cleanburnTemperature and O2 concentration constant and optimal during most of the combustion cycle T 350 0C CO 1 %0 O2 11%  Phase 1:  • Ignition of wood • A few minutes Phase 2:  • Combustion of pyrolysis gases • Intensive combustion with flames. • 25 - 30 minutes Phase 3:  • Combustion of char • The combustion intensity deceases  • The temperature decreases, the O2 and CO emission increase Phase 2 Phase 1 Phase 3 15 DTU Chemical Engineering,  Technical University of Denmark Manually controlled Automatically controlled Stable O2 and temperature, and low CO The same user Lack of combustion air in the flame  phase and too much air in the char combustion phase 16 DTU Chemical Engineering,  Technical University of Denmark Manually controlled Automatically controlled Lower O2 and temperature, and much higher efficiency  High excess air and temperature in both the flame phase and the char combustion phase The same user 17 DTU Chemical Engineering,  Technical University of Denmark  PM measurements: • Filter collection based on the Noweigan Standard NS-3058 • Scanning mobility particle sizer (SMPS)  Experimental setup Including: woodstove, stack, dilution tunnel, sampling sites, filters for particle collection and panel for gaseous analysis.  18 DTU Chemical Engineering,  Technical University of Denmark Charge 1 Phase 2 CO ppm VOC g/cm3 PM trend Phase 3 Ignition Time 0200040006000800013:26:24 13:55:12 14:24:00 14:52:48 15:21:36 15:50:24 16:19:12 16:48:00 17:16:48 17:45:360500100013:26:24 13:55:12 14:24:00 14:52:48 15:21:36 15:50:24 16:19:12 16:48:00 17:16:48 17:45:3605010013:26:24 13:55:12 14:24:00 14:52:48 15:21:36 15:50:24 16:19:12 16:48:00 17:16:48 17:45:36Charge 2 Charge 3 P1 P1 P1 Phase 2 Phase 2 Phase 3 Phase 3 • Increase in CO/VOC/PM in phase 1 • PM peak in phase 2 but low CO/VOC • Increase in CO (VOC) but low PM in phase 3 19 DTU Chemical Engineering,  Technical University of Denmark PM composition   • Condensable organic compounds  Example hexane (Tboil = 69 oC)  Example benzene (Tboil = 80 oC)  Initial release of volatiles from fuel   Temperature/mixing in the combustion zone   • Soot/Black carbon  High temperature & O2 lean formation   Potentially caused by insufficient mixing  Charge 1 Charge 2 Charge 3 Charge 4 0-15 min 15-30 min Charge 1: 1.8  ± 0.2 g / kgdry Charge 2: 1.8  ± 0.8 g / kgdry  Charge 3: 1.4  ± 0.4 g / kgdry  Charge 4: 0.5 g / kgdry  20 DTU Chemical Engineering,  Technical University of Denmark Conclusions  •A first version of an automatically controlled wood stove, HWAM IHS, has been developed and launched on the market.  •Results from a development and demonstration project have shown significantly reduced emissions and high efficiency for the automatically controlled stoves compared to manually controlled stoves.   • The new control system ensures improved stove operation even when used by private wood stove owners.  Thanks for your attention 

Advanced combustion control for a wood log stove, Expert workshop - Highly Efficient and Clean Wood Log Stoves

http://orbit.dtu.dk/ws/files/140844465/Berlin_workshop.pdf

Advanced combustion control for a wood log stove, Expert workshop - Highly Efficient and Clean Wood Log Stoves

Abstract

Similar works

Full text

Available Versions

Online Research Database In Technology