Elektromagnetni pospeševalnik za ustvarjanje kavitacije v vzorcih z majhnim volumnom

magistrsko delo

Simon Rezelj (Author), Henrik Lavrič (Mentor)

Abstract

Kavitacija je uveljavljena metoda za izboljševanje procesov v različnih industrijah, npr. zdravljenje ledvičnih kamnov v medicini, povečanje proizvodnje bioplina in komercialno zelo razširjena za ultrazvočno čiščenje potopljenih predmetov. Tema magistrske naloge izhaja iz predhodnih raziskav za izboljšanje procesa čiščenja odpadnih voda z uporabo kavitacije. V praksi se namreč pojavljajo težave, saj običajne metode za generiranje kavitacije zahtevajo relativno velike količine vzorcev za njihovo delovanje, ki jih zaradi varnostnih, finančnih ali drugih omejitev ni vedno mogoče pridobiti. V okviru magistrske naloge smo zato zasnovali novo napravo za generiranje hidrodinamične kavitacije v vzorcih majhnih volumnov, ki so primerni za testiranje medicinskih, farmacevtskih ali bioloških preparatov z volumnom manj kot 10 ml. V nadaljevanju magistrskega dela so predstavljene meritve na izdelani napravi ter simulacijski poizkusi elektromagnetnega modela naprave s programskim orodjem Ansys Maxwell. Opravili smo simulacijsko študijo različnih konstrukcijskih konfiguracij naprave. Odkrili smo, da je smiselna uporaba koncentratorjev magnetnega polja, saj ti povečajo povprečno silo na trajni magnet za 35 %. S teslametrom smo opravili meritve gostote magnetnega pretoka na površju feromagnetnega jedra. Primerjava s simulacijskimi rezultati kaže odstopanje simulacij od izmerjenih vrednosti za povprečno −18 %. Pri enakih meritvah na površini trajnih magnetov se izkaže, da so simulacije dovolj točne za naše potrebe, največje odstopanje od izmerjenih vrednosti je za −6, 7 %. Opravljene so meritve sile na trajni magnet vzdolž odprtine v jedru. Izmerjene sile so za povprečno 20 % večje od simuliranih. S primerjavo izvedenih meritev in elektromagnetnih simulacij smo prišli do spoznanja, da je uporaba simulacij smiselna in da so rezultati dovolj točni za nadaljnje raziskovanje delovanja naprave pri različnih konfiguracijah feromagnetnega jedra in trajnih magnetov. S programom Ansys Simplorer smo preizkusili delovanje različnih konfiguracij napajalnega in krmilnega dela naprave. Na podlagi rezultatov predlagamo implementacijo visokonapetostnega sistema napajanja, saj bi tako povečali strmino tokovnega pulza za več kot 2-krat. Predlagamo tri nove načine generiranja tokovnih pulzov: pulz s tokovnim repom, trapezna oblika pulza ter pulz za kompenzacijo sile. V zadnjem delu smo z visokohitrostno kamero, hidrofonom in tokovno sondo opazovali in analizirali dogajanje znotraj kavitacijske komore med delovanjem pri različnih konfiguracijah trajnih magnetov. Kot najbolj optimalna konfiguracija podsestava za generiranje kavitacije se je izkazal trajni magnet s sredinsko luknjo in le nekoliko manjšim zunanjim premerom od premera izvrtine kavitacijske komore. Razlika premerov mora omogočati prosto premikanje magneta po izvrtini.

Keywords

kavitacija;čiščenje odpadnih voda;Ansys;elektromagnetne simulacije;električne simulacije;magisteriji;

Data

Language:	Slovenian
Year of publishing:	2022
Typology:	2.09 - Master's Thesis
Organization:	UL FE - Faculty of Electrical Engineering
Publisher:	[S. Rezelj]
UDC:	621.3:676.08(043.3)
COBISS:	111980035
Views:	89
Downloads:	15
Average score:	0 (0 votes)
Metadata:

Other data

Secondary language:	English
Secondary title:	Electromagnetic accelerator for cavitation generation in samples with small volume
Secondary abstract:	Cavitation is an established method for improving processes in various industries, e.g. treatment of kidney stones in medicine, increasing biogas production and commercially widely used for ultrasonic cleaning of submerged objects. The topic of the master’s thesis derives from previous research to improve the process of wastewater treatment using cavitation. Problems arise as conventional methods for generating cavitation require relatively large amounts of samples for their operation, which cannot always be obtained due to security, financial or other constraints. Therefore, as part of the master’s thesis, a new device was designed for generating hydrodynamic cavitation in samples of small volumes, which are suitable for testing medical, pharmaceutical or biological preparations with a volume of less than 10 ml. In the following, measurements on the manufactured device and simulation experiments of the electromagnetic model of the device with the Ansys Maxwell software tool are presented. To begin with, a simulation study of different construction configurations of the device was performed. We found that it makes sense to use field concentrators, as they increase the average force on a permanent magnet by 35 %. A 3-axial teslameter was used to measure the magnetic flux density on the surface of the ferromagnetic core. A comparison with the simulation results shows the deviation of the simulations from the measured values by an average of −18 %. The same measurements on the surface of permanent magnets turn out to be accurate enough for our needs, as the largest deviation of the simulated values from the measured values is by −6, 7 %. Besides, measurements of the force on the permanent magnet along the opening in the core were performed. The measured forces are on average 20 % higher than the simulated ones. By comparing the performed measurements and electromagnetic simulations, it can be concluded that the use of simulations makes sense and the results are accurate enough to further investigate the operation of the device in different configurations of the ferromagnetic core and permanent magnets. Moreover, with the Ansys Simplorer software tool we tested the operation of various configurations of the power supply and control part of the device. Based on the results, we propose the implementation of a high-voltage power supply system, as this would increase the slope of the current pulse by more than 2 times. We propose three new ways of generating current pulses: current pulse with a tail, trapezoidal current pulse shape and current pulse for force compensation. In the last part of the master’s thesis, we observed and analysed the events inside the cavitation chamber during operation at different configurations of permanent magnets with a high-speed camera, hydrophone and current probe. A permanent magnet with a central hole and only a slightly smaller outer diameter than the diameter of the cavitation chamber bore proved to be the most optimal configuration of the sub-assembly for generating cavitation. The difference in diameters must allow the magnet to move freely through the hole.
Secondary keywords:	cavitation;waste water treatment;Ansys;electromagnetic simulations;electrical simulations;
Type (COBISS):	Master's thesis/paper
Study programme:	1000316
Embargo end date (OpenAIRE):	1970-01-01
Thesis comment:	Univ. v Ljubljani, Fak. za elektrotehniko
Pages:	XVIII, 73 str.
ID:	15654911