DIN-Fachbericht CEN TR 15716-2008 Solid recovered fuels - Determination of combustion behaviour English version CEN TR 15716 2008《固体再生燃料 燃烧特性的测定》.pdf

1、August 2008 Preisgruppe 19DIN Deutsches Institut fr Normung e.V. Jede Art der Vervielfltigung, auch auszugsweise, nurmit Genehmigung des DIN Deutsches Institut fr Normung e. V., Berlin, gestattet.ICS 75.160.10!$PK8“1454021www.din.deDDIN-Fachbericht CEN/TR 15716Feste Sekundrbrennstoffe Bestimmung des

2、 Verbrennungsverhaltens;Englische Fassung CEN/TR 15716:2008Solid recovered fuels Determination of combustion behaviour;English version CEN/TR 15716:2008Combustibles solides de rcupration Dtermination du comportement de la combustion;Version anglaise CEN/TR 15716:2008Alleinverkauf durch Beuth Verlag

3、GmbH, 10772 Berlin www.beuth.deGesamtumfang 43 SeitenDIN-Fachbericht CEN/TR 15716:2008-08 2 Nationales Vorwort Der CEN-Fachbericht wurde von der Arbeitsgruppe 4 Physikalische/mechanische Prfungen“ (Sekretariat: DIN, Deutschland) des Technischen Komitees CEN/TC 343 Feste Sekundrbrennstoffe“ erarbeite

4、t, dessen Sekretariat vom SFS (Finnland) gehalten wird. Das zustndige deutsche Gremium ist der Arbeitsausschuss NA 062-05-83 AA Sekundrbrennstoffe“ im Normenausschuss Materialprfung (NMP). Die Bestimmung des Verbrennungsverhaltens von festen Sekundrbrennstoffen erfordert umfassende Forschungsarbeite

5、n. Die in diesem Dokument dargelegte Vorgehensweise und vorgeschlagenen Prf-verfahren stellen eine Auswahl dar, um das Verbrennungsverhalten von festen Sekundrbrennstoffen zu bestimmen. Da sich die am Markt befindlichen Sekundrbrennstoffe bezglich ihrer physikalischen und chemischen Eigenschaften st

6、ark unterscheiden, muss in vielen Fllen eine individuelle Auswahl getroffen werden, um deren Verbrennungsverhalten belastbar zu charakterisieren, das heit, die vorgeschlagenen Prfverfahren sind nicht gleichermaen auf alle Sekundrbrennstoffe anwendbar. Von ihrer Normung wurde deshalb derzeitig abgese

7、hen. Aufgrund des groen ffentlichen Interesses an Verfahren zur Bestimmung des Verbrennungsverhaltens wurde entschieden, ber die zurzeit vorliegenden Forschungserkenntnisse in Form dieses Fachberichtes zu informieren. TECHNICAL REPORT RAPPORT TECHNIQUE TECHNISCHER BERICHT CEN/TR 15716 Juni 2008 ICS

8、75.160.10 English version Solid recovered fuels Determination of combustion behaviour Combustibles solides de rcupration Dtermination du comportement de la combustion Feste Sekundrbrennstoffe Bestimmung des Verbrennungsverhaltens This Technical Report was approved by CEN on 21. January 2008. It has

9、been drawn up by the Technical Committee CEN/TC 343. CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, P

10、oland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMIT EUROPEN DE NORMALISATION EUROPISCHES KOMITEE FR NORMUNG Management Centre: rue de Stassart, 36 B-1050 Brussels 2008 CEN All rights of exploitation in any form and

11、 by any means reserved worldwide for CEN national Members. Ref. No. CEN/TR 15716:2008: ECEN/TR 15716:2008 (E) 2 Contents Page Introduction .4 1 Scope 7 2 Combustion of solid fuels.7 2.1 Basis of solid fuel combustion.7 2.2 Basics of some common combustion systems that utilises SRF8 2.3 Determination

12、 of characteristic parameters .9 2.4 Use of classification numbers. 10 2.5 Combustion prediction tool. 10 3 Thermal gravimetric analysis 13 4 Standard fuel analysis 17 4.1 General. 17 4.2 Proximate analysis: Moisture, volatiles, and ash content 17 4.3 Ultimate analysis: C, H, N, S, Halogens 17 4.4 G

13、ross calorific value (GCV)/net calorific value (NCV). 18 4.5 Particle size distribution 18 4.6 Ash content and ash melting behaviour 19 5 Advanced laboratory methods for fuel characterisation 19 5.1 General. 19 5.2 Determination of fuel composition . 21 5.3 Composition and calorific value of the vol

14、atile matter. 22 5.4 Kinetic properties . 25 5.5 Image analysis method for particle size distribution 30 5.6 Apparent densities of particles and intermediates . 32 5.7 Aerodynamic lift velocity . 33 5.8 Slagging and fouling behaviour 34 6 Operational behaviour in the combustion process. 35 7 Summary

15、 38 Bibliography. 40 CEN/TR 15716:2008 (E) 3 Foreword This document (CEN/TR 15716:2008) has been prepared by Technical Committee CEN/TC 343 “Solid recovered fuels”, the secretariat of which is held by SFS. According to the CEN/CENELEC Internal Regulations, the national standards organizations of the

16、 following countries are bound to announce this Technical Report: Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia,

17、Slovenia, Spain, Sweden, Switzerland and the United Kingdom. CEN/TR 15716:2008 (E) 4 Introduction Historically, SRF goes back to the oil crises approximately 30 years ago, when refused derived fuel (RDF) was promoted as a substitute low cost fuel. Contrary to that situation, the producers of SRF too

18、k the initiative for the implementation of a quality system to meet and guarantee specified fuel classification and specification parameters. Quality systems to check their production now exist in several EU member states and efforts are being made by CEN/TC 343 to develop European Standards for SRF

19、 1. The production and thermal utilisation (energy recovery) of Solid Recovered Fuels (SRF) from bio wastes, residues, mixed- and mono waste streams have significant relevance as a key component of an integrated waste management concept. The implementation of SRF production in an integrated waste ma

20、nagement concept demands a potential market for these products. Known proven markets are found in the European energy sector and in other more product-oriented sectors like cement or lime industry by substitution of fossil fuels. The capacities for co-utilisation of these products, to include utilis

21、ation in minor thermal shares, are enormous, especially in the new European member states as most of the energy production of these countries relies on fossil fuels. A successful application of solid recovered fuel in power plants and industrial furnaces would require a thorough understanding of the

22、 fuel properties which include the combustion behaviour, emission potential, impact on facility etc. The determination of combustion behaviour which is the main focus of this document seeks to outline possible methods and procedures that can be adopted to analyse any given solid recovered fuel. An a

23、pproach has therefore been outlined where the determination of combustion behaviour is categorised into four groups which combine to give a holistic impression of the combustion progress of SRF in both mono and co-firing systems (see Figure 1). Figure 1 Scheme to determine combustion behaviour of SR

24、F While there are standardised methods, such as from the American Society for Testing and Materials (ASTM) and the German Institute for Standardization (DIN Deutsches Institut fr Normung e. V.), for determining combustion behaviour for primary fuels (e.g. coal), the process is not the same for SRF.

25、At present, there are no standardised methods for SRF. Most of the available methods are in-house, usually designed for particular types of SRF, e.g. waste, or bio-residue fractions to suit a specific combustion system like grate firing, fluidised bed, pulverised fuel system, and cement kiln. Figure

26、 2 gives an overview about the broad variety of SRF utilisation routes using an example of co-combustion in power plants and industrial furnaces. Co-combustion also includes indirect co-firing systems such as gasification (Lahti, Zeltweg) and pyrolysis CEN/TR 15716:2008 (E) 5 (ConTherm). While the e

27、nvironmental aspect of the thermal utilisation of SRF is very important, this report focuses only on the combustion aspect. Figure 2 SRF utilisation routes Solid recovered fuel can be made of any combustible non-hazardous waste and processed to a quality that allows to classify it in accordance with

28、 CEN/TS 15359 and which fulfils specifications as agreed with the customer. Considering this, the main problem becomes obvious: How to define reliable methods to describe the combustion behaviour of solid fuels such as SRF, valid for all possible types of input material and combustion systems? A sys

29、tematic approach adopted herein to determine combustion behaviour is outlined in Figure 1. It is grouped into four categories: standard fuel analysis; laboratory-scale tests with advanced methods; semi-technical and pilot-scale combustion tests; full-scale test. In general, such a four-step procedur

30、e is an effective way to successfully integrate a new fuel in an existing power plant or an industrial furnace. In any case, full scale tests are the most reliable but very expensive with several bottlenecks (e.g. retrofits, permits, time, etc.) and that is the reason for the need to develop and sta

31、ndardise methods which are reliable, fast, and not expensive according to the various firing systems are essential. Besides the evaluation of parameters concerning combustion behaviour, the steps before full scale implementation also forms substantial basis to reliably evaluate other areas of major

32、interest such as grinding and fuel feeding; slagging, fouling and corrosion; and lastly emissions and residues. The systematic evaluation of these additional topics requires area specific analyses, tests, and measurements. CEN/TR 15716:2008 (E) 6 Concerning combustion behaviour, the standard analysi

33、s of the SRF will determine the basic parameters about the combustible and incombustible matter. The amount of energy, the contents of water, volatiles, fixed-carbon, ash, and particle size will roughly dictate the type of the combustion system that is best suited. In addition to the standard analys

34、is, a selected combustion system might require an advanced parameter analysis, if possible, with a close relation to case specific process parameters. Such a correlation will substantially enhance the reliability of transfer studies. An example, in the case of a pulverised firing system, is the maxi

35、mum particle size required for a complete combustion in order to avoid fuel plummeting into the bottom ash. Currently, the activities towards the combustion behaviour of SRF rely largely on standard analysis and laboratory-scale tests, which were originally developed with certain limitations and app

36、licable to solid fuels such as lignite and hard coal. A common problem of these methods is that parameters related to SRF during combustion are not sufficiently covered. These methods make sure consistent quality of the SRF supply rather than to predict combustion performance. Therefore, the develop

37、ment of the so-called advanced test methods to fill the gap and amending existing test apparatus and measurement conditions is required. The driving force to introduce SRF rests much on economic factors. In most cases, the end user will be either the operator of a power plant or an industrial furnac

38、e. The primary focus will be an unrestricted and reliable operation of the facility. One wants to assess the possible risks and dangers. In case of retrofits, the end user needs to calculate the required cost on modifications and operation. It can be assumed that due to possible operational risks su

39、ch as corrosion, the plant operators will select the fuel with the most appropriate qualities. Such requirements are needed tools to control the quality of the SRF and to deliver them according to specification. As such, the knowledge of the combustion behaviour is an essential aspect for the commer

40、cialisation of SRF. It will allow the optimisation of the process and the assessment of possible risks and dangers prior to full-scale application. Some methods and parameters will be introduced in the subsequent sections, but whatever methods are to be used in the future should be orientated toward

41、s the following aspects: reproducibility; repeatability; reliability; time efforts (rapid test methods); cost effectiveness; possibilities for automatic testing. The authors summarise and refer to past and current activities trying to describe combustion behaviour of SRF. The idea is to identify a c

42、ommon and successful practice where various approaches converge. CEN/TR 15716:2008 (E) 7 1 Scope This Technical Report gives a review on determination methods for exploring how different SRFs behave in different combustion systems, e.g. with respect to time for ignition, time for gas phase burning a

43、nd time for char burn out, including information on technical aspects like slagging and fouling, corrosion as well as required flue gas cleaning for meeting the emission limit values induced by the Waste Incineration Directive (WID). 2 Combustion of solid fuels 2.1 Basis of solid fuel combustion Com

44、bustion of fuels shall be considered both from theoretical and practical perspectives. The former can define combustion as the rapid chemical reaction of oxygen with the combustible elements of a fuel. While the later where the engineer is concerned with boiler design and performance might define co

45、mbustion as the chemical union of fuel combustibles and the oxygen of the air, controlled at a rate that produces useful heat energy. The two definitions implicitly consider many key factors. For complete combustion within a furnace, four basic criteria shall be satisfied: 1) adequate quantity of ai

46、r (oxygen) supplied to the fuel; 2) oxygen and fuel thoroughly mixed (turbulence); 3) fuel-air mixture maintained at or above the ignition temperature; 4) furnace volume large enough to give the mixture time for complete combustion. Quantities of combustible constituents within the fuel vary by type

47、s. Figure 3 shows the significant change in the combustion air requirements for various fuels, resulting from changes in fuel composition. It illustrates the minimum combustion air theoretically required to support complete combustion. Key Y Stochiometric air demand in nominal cubic meter dry air pe

48、r kilogram fuel Figure 3 Stoichiometric air to fuel ratio for some SRFs CEN/TR 15716:2008 (E) 8 In an ideal situation, the combustion process would occur with the stoichiometric quantities of oxygen and a combustible based on underlying chemical principles. However, since complete mixing of air and

49、fuel within the furnace is virtually impossible, excess air shall be supplied to the combustion process to ensure complete combustion. The amount of excess air that should be provided varies with the fuel, boiler load, and type of firing system, and it is in the range of 0,1 0,6 or even more. Solid fuel combustion consists of three relatively distinct but overlapping phases: heating phase (time to ignition); gas phase combustion (time of gas phase burning); char combustion (time for char burnout). First