magistrsko delo
Abstract
Za termoenergetske postroje so države postavile pravila, ki narekujejo omejitve emisij
zdravju škodljivih plinov. Ta pravila so povzročila razvoj tehnologij čiščenja dimnih plinov,
emitiranih iz termoenergetskih postrojev. Eden največjih onesnaževalcev je žveplov
dioksid (SO2), ki nastaja pri zgorevanju premoga, onesnaženega z žveplom. V magistrskem
delu obravnavamo mokri kalcitni postopek, ki zahteva izgradnjo pralnika dimnih
plinov. V pralniku se žveplov dioksid absorbira v kapljice vode, v katerih je raztopljen
apnenec. V reakciji ki poteče, nastane kalcijev sulfid (CaSO3), ki ob prenasičenju v vodi
tvori kristale. Nastala suspenzija se zbira v spodnjem delu pralnika – rezervoarju, ki
skrbi za tvorbo stabilnega produkta, kalcijevega sulfata (CaSO4). Slednje je izvedeno s
prisilno oksidacijo, z uporabo kombinacije razpršilnih šob in mešal (agitatorjev), ki poskrbijo
za čim daljši zadrževalni čas disperzne faze. Predstavljen je numerični model
rezervoarja pralnika dimnih plinov, s katerim simuliramo večfazni tok v rezervoarju. V
tem modelu obravnavamo tok zvezne faze (vode) in disperzne faze (mehurčkov zraka).
Modelirano je vpihovanje zraka v področje pred agitatorji, vpliv tokovnega polja agitatorjev
na distribucijo disperzne faze in obtočne črpalke, kot iztok tekočine iz rezervoarja.
Razvoj Sauterjevega premera mehurčkov je modeliran po populacijskem modelu. Namen
izdelave modela je bil analizirati vpliv obtočnih črpalk, ki domnevno motijo učinkovito
disperzijo zraka. Rezultati kažejo, da izteka največ zraka skozi obtočno črpalko v skrajni
legi, skupno pa skozi obtočne črpalke uhaja 1.2 % vpihanega zraka oz. 0.03 m3/s.
Preračun je izveden v odprtokodnem programskem paketu OpenFoam v10, z uporabo
superračunalniške infrastrukture v okviru projekta HPC RIVR.
Keywords
pranje dimnih plinov;disperzija zraka;numerični model;OpenFoam;superračunalnik;magistrske naloge;
Data
Language: |
Slovenian |
Year of publishing: |
2023 |
Typology: |
2.09 - Master's Thesis |
Organization: |
UM FS - Faculty of Mechanical Engineering |
Publisher: |
[N. Vovk |
UDC: |
004.414.23:662.963(043.2) |
COBISS: |
168606723
|
Views: |
89 |
Downloads: |
33 |
Average score: |
0 (0 votes) |
Metadata: |
|
Other data
Secondary language: |
English |
Secondary title: |
Numerical modelling of two-phase flow inside wet flue gas scrubber sump |
Secondary abstract: |
Countries have set rules for thermal power plants that dictate limits on emissions of
harmful gases. These rules caused the development of technologies to clean the flue
gases emitted from thermal power plants. One of the biggest pollutants is sulfur dioxide
(SO2), which is produced by burning sulfur-contaminated coal. In the masters thesis
we examine a wet calcite process, that requires the construction of a flue gas scrubber.
Inside the scrubber, sulfur dioxide is absorbed into water droplets that contain dissolved
limestone. The reaction that takes place produces calcium sulfide (CaSO3) which forms
crystals when supersaturated in water. The resulting suspension is collected in the lower
part of the scrubber, called the sump, which ensures the formation of a stable product,
calcium sulfate (CaSO4). The latter is achieved by forced oxidation, using a combination
of spargers and agitators to ensure that the dispersed phase is retained for as long as
possible. A numerical model of the flue gas scrubber sump is presented, to simulate the
multiphase flow inside the sump. In this model, the flow of continuous phase (water) and
dispersed phase (air bubbles) are considered. The air blowing in front of the agitators,
the influence of agitator flow field on the distribution of dispersed phase and recirculation
pumps as the outlets are modeled. The development of bubble Sauter mean diameter is
modeled using the population balance model. The purpose of the model is to analyze
the influence of recirculation pumps, which are assumed to interfere with the effective
dispersion of air. Results show that most of the air escapes through the pump outlet near
the agitator. A total of 1.2 % (0.03 m3/s) of the entrained air escapes through the pump
outlets. The calculation is performed in the open source software package OpenFoam
v10, using the supercomputer infrastructure of the HPC RIVR project. |
Secondary keywords: |
flue gas scrubbing;air dispersion;numerical model;supercomputer; |
Type (COBISS): |
Master's thesis/paper |
Thesis comment: |
Univ. v Mariboru, Fak. za strojništvo, Energetsko, procesno on okoljsko strojništvo |
Pages: |
1 spletni vir (1 datoteka PDF (XII, 75 f.)) |
ID: |
19751374 |