Odločitveni model najustreznejših parametrov izdelave lesnih sekancev

doktorska disertacija

Mitja Krajnc (Author), Bojan Dolšak (Mentor), Aleš Hribernik (Co-mentor)

Abstract

Z uporabo naprednih tehnologij pri delovanju kotlov na lesno biomaso pridobivalesno gorivo vse večji pomen. Izdelava kvalitetnega lesnega goriva zahteva veliko znanja in izkušenj, povezana pa je z večjim številom vplivnih parametrov. Uvrstimo jih lahko v tri kategorije, in sicer materialne, konstrukcijske in tehnološke. Materialne se nanašajo na lesno biomaso, tehnološke in konstrukcijske pa na sekalnik. Na materialne parametre imamo omejen vpliv, saj v sekance običajno predelamo surovino, ki je trenutno na voljo. Lahko pa izboljšujemo proces proizvodnje z izbiro ustreznih vrednosti konstrukcijskih in tehnoloških parametrov. Na osnovi monitoringa dimnih plinovin analize pepela smo določili najprimernejše lastnosti lesnih sekancev,ki zagotavljajo najvišji termični izkoristek. Izvajali smo ga na kotlu, moči 3.500 kW, v kotlovnici Lenart. Ugotovili smo, da so za večje sisteme primernejši sekanci večjega velikostnega razreda pri mehkem lesu, ter manjšega velikostnega razreda pri trdem lesu. Lesni sekanci naj vsebujejo čim manj prahu ter imajo čim bolj enakomerno velikostno strukturo. V okviru raziskovalnega dela smo izdelali računalniški model velikega bobnastega sekalnika, ki smo ga uporabljali pri praktični izdelavi lesnih sekancev. S pomočjo kinematične analize smo simulirali možne spremembe vplivnih parametrovin ocenili teoretično dolžino lesnih sekancev. Izbrali smo vplivne parametre, ki v največji meri vplivajo na kvaliteto sekancev, določili njihovevrednosti in raziskali njihov medsebojni vpliv. V okviru eksperimentalnega dela doktorske disertacije smo proizvajali lesne sekance želenih lastnosti in jih primerjali z rezultati računalniške simulacije. Ugotovili smo odstopanja in pojasnili vzroke za njihov nastanek. S pomočjo rezultatov praktičnih testiranj smo izdelali odločitveni model, ki na podlagi danih lastnosti vhodne surovine in želenih lastnosti lesnih sekancev predlaga najprimernejše vrednosti konstrukcijskih in tehnoloških parametrov. Odločitveni model smo vgradili v spletno aplikacijo, ki smo jo poimenovali Bober.

Keywords

biomasa;bobnasti sekalniki;vplivni parametri;odločitveni modeli;

Data

Language:	Slovenian
Year of publishing:	2014
Typology:	2.08 - Doctoral Dissertation
Organization:	UM FS - Faculty of Mechanical Engineering
Publisher:	M. Krajnc]
UDC:	[004.942:676.051.36]:674.815(043.3)
COBISS:	272117248
Views:	1984
Downloads:	227
Average score:	0 (0 votes)
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Other data

Secondary language:	English
Secondary title:	DECISION SUPPORT MODEL FOR THE MOST APPROPRIATE PARAMETERS IN PRODUCTION OF WOOD CHIPS
Secondary abstract:	With the use of advanced technologies in the operation of biomass boilers, wood fuel is gaining importance. Production of quality wood chips requires a lot of knowledge and experience. Its production is linked to a number of influential parameters, which can be classified into three categories: material, construction and technological. Material parameters relate to biomass, technological and construction parameters relate to chipper. There islimited influence on material parameters because raw material that is currently available is usually processed into wood chips. However production process can be controlled through the selection of the adequate values of construction and technological parameters. Based on the monitoring of flue gases and ash analysis, the optimum characteristics of wood chips that providethe highest thermal efficiency were determined.. Monitoring was executed using 3,500 kW bio boiler in the boiler room Lenart. We found that for larger systems, larger chips from soft wood and smaller ships from hard wood are more suited. Wood chips should contain as little dust as possible andhave an even size structure. Computer model of a large drum chipper, which was used in the experimental production of wood chips, was designed. Through the kinematics simulation we defined possible changes of influencing parameters and assessed the theoretical length of the wood fibers. Influentialparameters, which have the greatest effect on the quality of the chips, were selected. We set their values and explored their interactions. In experimental part, woodchip with desired properties were produced and comparedwith the results of computer simulations. We found some deviations andexplained causes for them. Using the results of the practical tests, a decision model was developed. It proposes the most appropriate values of construction and technological parameters based on the material properties of raw material and desired properties of wood chips. Decision model has been integrated into a web application that was named 'Bober'.
Secondary keywords:	biomass;wood chips;drum chipper;influential parameters;decision model;Lesna biomasa;Disertacije;Lesni sekanci;Izdelava;
URN:	URN:SI:UM:
Type (COBISS):	Dissertation
Thesis comment:	Univ. Maribor, Fak. za strojništvo
Pages:	XI, 134 f.
ID:	8728598