Numerična analiza pogojev zgorevanja odpadkov in optimizacija zgorevalnega prostora kurilne naprave z rešetko

doktorska disertacija

Miran Kapitler (Author), Niko Samec (Mentor), Leopold Škerget (Co-mentor)

Abstract

Proces zgorevanja, ki se odvija v kurilnih napravah in uporablja mestne komunalne odpadke kot gorivo, zahteva natančno razumevanje tega fenomena. Ta proces je odvisen od mnogih vhodnih parametrov, kot je kvalitativna analiza mestnih komunalnih odpadkov, letni čas, hitrost vstopnega primarnega in sekundarnega zraka, ter od izhodnih parametrov, kot je temperatura ali masno razmerje produktov zgorevanja na izstopu. Upravljanje s spremenljivostjo in medsebojno odvisnostjo teh parametrov je v praksi lahko zelo oteženo, saj moramo zagotoviti optimalno zgorevanje z minimalnimi emisijami polutantov že vprojektni fazi. Z uporabo računalniške dinamike tekočin smo proučevali realnokurilno napravo z zgorevanjem na rešetki s programskim paketom ANSYS CFXv okolju WORKBENCH 2. V nalogi smo uporabili variabilne robne pogoje vhodnih parametrov, ki bazirajo na rezultatih drugih avtorjev, in uporabili turbulentne, zgorevalne in sevalne modele ter modele za prenos toplote. Nadalje smo optimirali obratovalne pogoje obstoječe kurilne naprave in geometrijske parametre nove s pomočjo ciljno usmerjene optimizacije, tridimenzionalno napovedali in slikovno predstavili čas zadrževanja, temperaturna in hitrostna polja, tokovnice, sledili delcem letečega pepela, poljam koncentracij reaktantov in produktov zgorevanja ter formiranju dušikovih oksidov. Cilj optimizacije je ugotoviti vrednost posameznega vhodnega parametra, pri katerem obstoječa naprava dosega optimalne ali kritične - škodljive obratovalne pogoje oziroma optimalne dimenzije nove. dvisnost med vhodnimi in izhodnimi parametri, ki jih definiramo in predstavljajo specifične pokazatelje popolnosti zgorevanja, smo prikazali v odzivnih diagramih, stopnjah občutljivosti posameznega parametra, histogramih in linearnih korelacijskih matrikah. Ta spoznanja nam zagotavljajo pomoč pri upravljanju kurilne naprave in preprečevanju kritičnih režimov obratovanja prineugodnih spremembah obratovanja ter pri snovanju novih. rikazan znanstveni pristop omogoča CFD analizo, numerično optimizacijo obratovalnih pogojev in zgorevalnega prostora že v sami projektni fazi snovanja bodoče kurilne naprave, kar nam omogoča hitrejši in učinkovitejši razvoj izdelka s pričakovano kakovostjo in obratovalno zanesljivostjo ter občutno znižuje stroške raziskav in daje prednost pred konkurenco.

Keywords

kurilne naprave;sežig v plasti na rešetki;računalniška dinamika tekočin;sledenje delcev pepela;linearna korelacijska matrika;histogrami;računalniški programi;

Data

Language:	Slovenian
Year of publishing:	2012
Source:	[Maribor
Typology:	2.08 - Doctoral Dissertation
Organization:	UM FS - Faculty of Mechanical Engineering
Publisher:	M. Kapitler]
UDC:	628.4.03(043.3)
COBISS:	261987328
Views:	2331
Downloads:	266
Average score:	0 (0 votes)
Metadata:

Other data

Secondary language:	English
Secondary title:	Numerical analyse of municipal solid waste combustion conditions and grate furnance combustion chamber optimization
Secondary abstract:	The combustion process for using municipal solid waste (MSW) as a fuel within a waste-to-energy plant (WTEP) requires a detailed understanding of the following phenomena. Firstly, this process depends on many input parameters such as MSW proximate and ultimate analysis, the season of the year, primary and secondary air-inlet velocity and, secondly, on output parameters such as the temperatures or mass-flow rates (MFR) of the combustible products. In manycases, the variability and mutual dependence of these parameters can be difficult to manage in practice in order to achieve the optimal combustion with minimal pollutant emissions during the initial plant-design phase. The real WTEP with grate incineration has been investigated by using a computational fluid dynamics (CFD) approach with ANSYS CFX 12.0 code within a WORKBENCH 2 environment. The adequate variable input boundary conditions basedon other authors are used with the appropriate turbulence, combustion, radiation and heat transfer models as well. Furthermore, the operating parameters of a real WTEP and geometric parameters of a new one were optimizedwith a goal driven optimization, and predict residence time, temperature field, velocity-field, streamlines, flying ash particle tracking, combustion's reactants and products with nitric oxide formation in 3D were predicted and visualized. The goal of optimization is to find out the amounts of each input parameter which meets the optimal operating conditions or critical operating regimes in existing WTEP or the optimal geometric dimensions of new one. Input and output parameters impact, which were definedand present the specific indicators of complete combustion, are shown in response charts, parameters sensitive, histograms and linear correlation matrix. These cognitions give us the assurance how to manage WTEP and to avoid operating in critical regimes which were caused by inconvenient operating changes and in new projects, respectively. Finally, the present scientific approach enables us the CFD analyze, numerical optimisation of operating conditions and combustion chamber within early project phase. This allows us faster and effective product development with expected product quality and operating reliability and huge costs reduce of researches and give us the competitive advance.
Secondary keywords:	Komunalni odpadki;Disertacije;Sežiganje;Modeliranje;
URN:	URN:SI:UM:
Type (COBISS):	Dissertation
Thesis comment:	Univ. Maribor, Fak. za strojništvo
Pages:	X, 141 str.
Keywords (UDC):	applied sciences;medicine;technology;uporabne znanosti;medicina;tehnika;engineering;technology in general;inženirstvo;tehnologija na splošno;public health engineering;water;sanitation;illuminating engineering;sanitarna tehnika;zdravstvena tehnika;voda;sanitarne naprave;svetlobna tehnika;urban hygiene;wastes;refuse;rubbish;garbage;collection and disposal of town wastes;komunalna higiena;
ID:	1002349